O. Cozar

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PLENARY LECTURES ............................................................................................................ 1

ISOTOPIC PROCESSES ........................................................................................................ 13

ORAL PRESENTATIONS .................................................................................................. 13

POSTERS ............................................................................................................................ 27

MOLECULAR PROCESSES .................................................................................................. 57

ORAL PRESENTATIONS .................................................................................................. 57

POSTERS ............................................................................................................................ 71

AUTHORS ............................................................................................................................. 131

ISOTOPIC PROCESSES .................................................................................................. 131

MOLECULAR PROCESSES ............................................................................................ 137

P l l l e n a r r r y l l l e c t t t u r r r e s s s

1

2

PROCEDURES TO DETERMINE THE GUARANTEED

PRODUCTION CAPACITY OF A HEAVY WATER PLANT

Marius Peculea

Romanian Academy, Bucharest, Romania

The capacity of a heavy water plant is determined by its design and represents a product between the plant production/hour and the running time.

The product/hour is calculated for steady state conditions and the working time is estimated by the designer. Actually, the isotopic separation process takes place in unsteady state conditions and the working time is affected by equipment dysfunction or even damages, after which a relaxation time is necessary for isotopic profile recovery along the separation columns.

For determining the actual capacity, the designed capacity is corrected by the product of three coefficients: availability, reliability, and relaxation. The knowledge of the above mentioned coefficients allows the determination of the actual plant capacity; this is important also for further improvements of the separation technology and represents research objectives during the whole existence of such a plant in order to maintain it at an international level of competitiveness.

The detailed content of the three coefficients and the way they were determined and experimentally verified on an industrial pilot plant for heavy water production by isotopic exchange at two temperatures in H

2

O - H

2

S system, are presented in this paper.

3

OVERVIEW OF USES AND NEEDS OF SEPARATED ISOTOPES

Michel Couairon

(a)

, Edgar Soulié

(b)

, Alain Alberman

(c)

(a)

CEA/SACLAY, DCC/DPE, 91191-Gif Sur Yvette Cedex (France),

E-mail :

rousseau@carnac.cea.fr

(b)

CEA/SACLAY, DSM/DRECAM, 91191-Gif Sur Yvette Cedex (France),

E-mail :

bsoulie@drecam.cea.fr

(c)

CEA/SACLAY, DRN/DRE, 91191-Gif Sur Yvette Cedex (France),

E-mail :

alberman@dre.cea.fr

This synthesis paper is a supplier’s glance through present use and potential need for artificially separated isotopes. We focus on stable isotopes since many enriched stable compounds are now required for their unique properties in several high values economic sectors:

1.

In environmental and biological sciences

. Preferred isotopes remain

D

,

13

C

,

15

N

,

18

O

.

The whole French consumption amounts to about five Metric Tons (T) for heavy water and to a few kg for the others, per year. Generic applications encompass a broad spectrum, from drug metabolism up to insecticide research against the bark beetle of spruce.

2.

In health-care systems

. The need of radioisotopes for medical imaging is expected to increase in European countries (E.U.) by more than 3% a year. Several highly purified stable isotopes are required in order to produce the radioisotopes by neutron, gamma, or particle irradiations. Therefore, we could not raise a sharp fence between radioisotopes

 and their related stable precursors, such as [

88

Sr

,

98

Mo

,

185

Re

203

Tl

,

for irradiations in a high flux reactor.

124

Xe

] for cyclotron targets or

3.

In nuclear power industry

.

7

Li

Lithium is used by a ten kg a year as buffer for boric acid in many Pressurised Water Reactors (PWR). Boron

10

B

could be used by many ways: as enriched boric acid for shim control in PWR; as liquid sodium pentaborate in the stand by control systems for Boiling Water Reactors (BWR); and perhaps as a solid absorber in the rod clusters for Moxed-PWR. Enriched lanthanide trioxides are potential burnable absorbers in fuel; the need would amount to ca. forty kg a year, for every high burn-up Light LWR. Heavy water is now used by five hundred tons in one

Pressurised Heavy Water PHWR. For fusion pilots JET and ITER, deuterium and tritium inventory for new programs will gradually increase from about thirty to a hundred grams, with mixing with helium-3 by gram quantities. For a fusion reactor, tritium breeding in a blanket made either of a liquid metal or of a Be-Li fluoride molten salt, will contain several hundred kilograms of

6

Li

enriched lithium.

4

DYNAMICAL AND STRUCTURAL STUDIES OF SOME

MOLECULAR COMPLEXES

BY EPR SPECTROSCOPY

O. Cozar

Faculty of Physics, "Babeş-Bolyai" University, RO-3400 Cluj-Napoca,

Romania

Many studies about molecular structure and molecular dynamics of some complex combinations of biological relevance have been done in the last years.

We have obtained significant results about the electronic structure of these complexes, metal ion - ligand of biological interest interaction, solvent effects, modification of the local symmetries by the ligand - solvent subtraction, molecular association effects with the synthesis of some dimeric (polymeric) species and the behaviour of some organic molecules in nuclear radiation fields.

These results were published in speciality reviews and were also presented at different international conferences.

The main directions of the research are the following:

Interactions between metal ions - drugs and biologically interesting molecules

(anti-inflammatory, tranquillising, antibacterial, aminoacids, nucleotides);

Solvent effects on the metal complexes with biologically active ligands and molecular association mechanisms;

Molecular dynamics of nitroxidic radicals adsorbed on some surfaces and in polymeric solutions;

Identification of the radiation products in some biomolecules, kinetics and recombination aspects in connection with adsorbed radiation dose, time and temperature;

Structural investigation and interaction between metal ion - ion pairs in some heteropolyoxometalates compounds containing V

4+

, Cu

2+

, Fe

3+

, Mo

5+

, W

5+

;

Structural studies concerning possibilities of radioactive waste storage in polyoxometalates.

5

REAL TIME STUDIES IN INFRARED MULTIPHOTON

DISSOCIATION INDUCED BY ONE OR TWO

WAVELENGTHS

M. Santos, L. Rubio, L. Díaz and J.A. Torresano

Instituto de Estructura de la Materia.

C.S.I.C.

Serrano, 121.

28006-Madrid. Spain

Infrared Multiphoton Dissociation (IRMPD) is one of the more general techniques for inducing unimolecular reactions from the ground electronic state and for obtaining free radicals with a high degree of vibrational and rotational energy. Analysis of the Spontaneous

Luminescence (SL) emitted in the dissociation process and Laser induced fluorescence technique (LIF) allow to follow in real time the production of the radicals providing valuable data about both the kinetics of the dissociation reactions and the nascent energy distribution among the produced fragments.

In this work we present the results obtained from the SL and LIF study of some fragments formed in the IRMPD of some halogenated polyatomic molecules.

In C

3

F

6

the irradiation is carried out with one or two infrared laser fields, simultaneous or controllably delayed, using focused or parallel geometries. We have proven in real time the fundamental role played by fluency in the dissociation process of this molecule confirming the results of bulk experiments. We have obtain the excitation spectra of the CF

2

fragments formed in each of the employed experimental conditions verifying that the use of one or two infrared laser field as well as their frequencies are determinant in the content of the vibrational and rotational energy of the formed CF

2

radicals.

The low dissociation threshold obtained in the IRMPD of TFA, both in focused and parallel geometries, indicates that this molecule opposes a low anharmonic bottleneck to the absorption process. This efficient dissociation reaction allows the determination of the translational energy of the CF

2

formed in the dissociation process, obtaining a value for the translational energy of 1.6 kcal mol

-1

.

6

THE ROLE OF THE ISOTOPOMERS IN THE VIBRATIONAL

SPECTROSCOPY

Ferenc Billes

Department of Physical Chemistry, Technical University of Budapest,

H-1521 Budapest, Budafoki út 8., E-mail: billes.fkt@chem.bme.hu

In this lecture, we try to introduce the importance of the isotopomers for the vibrational spectroscopist.

The infrared and the Raman spectroscopies are the most important experimental methods of the vibrational spectroscopy. Normally, spectra of the isotopomers with atoms of the highest abundance are recorded. Less attention was paid on the vibrational spectroscopy of isotopomers.

The theoretical spectroscopy, however, found the isotopomers important already in the

‘50s. Two rules, the product and the sum rules helped in the control of the experimental assignments of the spectra.

The preparation of the isotopomers is sometimes very complicate since there may be necessary even a total synthesis of the compound. Spectroscopists deal very rarely with organic syntheses therefore they need the aid of the organic chemists. Sometimes the need of the solution of structural problems arises from the organic chemists and in this case, the problem of the synthesis is easier solved.

Since the frequencies of the vibrational modes are mass dependent, a large wavenumber shift is observable if hydrogen is changed for deuterium. If the hydrogen in the organic molecule is a “movable” one, e.g. NH and OH groups, the substitution is relatively easy, one have to heat or stir the compound with heavy water during several hours up to reaching the equilibrium. With this also a the problem arises for the spectroscopist: he cannot have the spectrum of the pure deuterated compound.

Sometimes the deuteration plays a joke on the researcher. Namely, if one deuterates heterocyclic compounds with NH group and some nitrogen atoms in the ring then also the

CH groups become deuterated.

The fast development of the quantum chemistry brought a very good tool for the assignment of the vibrational spectra of small or medium size molecules. The determination of the molecular force field (matrix F) became unambiguous. Applying the optimised molecular geometry and the atomic masses one can calculate the inverse kinetic energy matrix (G matrix). Having a good experimental assignment one can scale the matrix F to the experimental fundamentals and using this scaled F the character of the vibrational modes

(participation of the different internal motion types) can be determined. If one has isotopomers one can assume that the vibrational force field and the geometry of the molecule do not change, the origin of the frequency shifts is only the change in the atomic masses. So we have a modified G matrix. One can calculate the frequencies of the isotopomer and assign to them the experimental spectrum. If the agreement of the experimental and calculated frequencies is good than the force field and the assignments of the parent molecule spectra were appropriate.

Sometimes the deuteration decreases the strength of the hydrogen bond and therefore the individual bands are observable better. The recording of the Raman spectra is a very good tool for the elimination of the association bands also for the deuterated compounds.

Some interesting examples of the application of the deuterated isotopomers will be presented in the lecture.

7

8

STRUCTURES AND PROCESSES IN SUPRAMOLECULAR

CHEMISTRY

I. Haiduc

Romanian Academy

RECENT DEVELOPMENTS OF SUB- AND SUPERCRITICAL

FLUID EXTRACTION IN ENVIRONMENTAL ANALYSIS

R. Alzaga and J.M. Bayona

Environmental Chemistry Department. IIQAB-CID-CSIC. Barcelona. Spain.

In the last decade, analytical procedures for the determination of trace contaminants in environmental samples have been developed. However, since most of these methodologies involve tedious and time consuming sample preparation steps, current interest is focused on the development of methodologies involving solvent minimisation and the extraction selectivity improvement.

Supercritical fluids namely carbon dioxide in presence of modifiers were introduced in the analytical laboratory at the end of the last decade because their higher diffusion coefficient and lower viscosity than liquids and the lack of surface tension for the extraction of contaminants from soils and sediments. The main advantage of supercritical fluids is the faster extraction kinetics in comparison of liquids and higher extraction selectivity. More recently, pressurised liquid solvents at temperatures above the boiling point were also evaluated for environmental analysis. That technique (PFE, pressurised fluid extraction) was also introduced to reduce the extraction time and to reduce the use of solvents.

In this presentation, different strategies using supercritical fluids and pressurised solvents for the extraction of organic contaminants from environmental samples will be presented.

Experimental design has been applied to cut down the number of optimisation experiments during the extraction and to obtain surface response of the extraction according with key variables. Furthermore, modifier selection strategies have been developed depending on the analyte and the matrix. From the chemical characteristics of the modifier, the predominant matrix-contaminant interactions are proposed.

Finally, the developed analytical procedures have been validated against existing reference materials or conventional extraction techniques such as Soxhlet or sonication.

9

ION FOCUSING PROCEDURES IN TIME-OF-FLIGHT

MASS SPECTROMETRY

D. Ioanoviciu

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5, Romania

The intact ionisation of big molecules by soft ionisation methods, as matrix assisted laser desorption ionisation and fast atom bombardment, paved the way of mass spectrometry to very high mass ranges (approaching the million of Daltons). This was possible by the branch of timeof-flight mass spectrometry. However, time-of-flight mass spectrometry is lagging far behind other branches as mass resolution, the highest value recently reported being of 45000. This is a well-documented reason why in time-of-flight mass spectrometry ion packet focusing remains a hot problem.

The space focusing in time in linear drift time-of-flight mass spectrometers is discussed including first and second order focusing conditions, second and third order aberrations. The resolution of such instruments is determined and compared to the real performances of some constructed instruments. The focusing conditions for delayed ion extraction are presented and examples given for presently used time of flight mass spectrometers with matrix assisted laser desorption ionisation sources. The post source ionisation method and its effect on the spectrometer mass scale are detailed.

The ion energy focusing in time to first and second order in single and double staged electric field mirrors is studied. An explanation is given why time-of-flight mass spectrometers including mirrors are able of much higher resolutions than those based on flight on drift spaces only. The major interest in careful velocity focusing is expressed by the use of the delayed extraction in time of flight mass spectrometers, which include reflectrons. Again, the focusing conditions and aberrations are detailed. A special attention is focused on the possibility to obtain high order velocity focusing for ions created on the surface of hyperbolic electrodes. Also the focusing methods with perfect time focusing by hyperbolic traps and by the so-called "curved field" were reviewed, especially as means to focus fragment ions from metastable disintegrations.

Finally, a comparison of the different time focusing methods is given. The ways to push time of flight mass spectrometers' resolution to higher levels and the most important directions were analysed.

10

USES OF STABLE ISOTOPES

Damian Axente

National Institute for Research and Development of Isotopic and Molecular

Technologies, 3400 Cluj-Napoca 5, P.O.BOX 700, Romania.

The most important fields of stable isotopes use with examples are presented.

- Isotope dilution analysis

: trace analysis, measurements of volumes and masses.

- Stable isotopes as tracers

: transport phenomena, environmental studies, agricultural research, authentication of products and objects, archaeometry, studies of reaction mechanisms, structure and function determination of complex biological entities, studies of metabolism, breath test for diagnostic.

- Isotope equilibrium effects

: measurements of equilibrium effects, investigation of equilibrium conditions, mechanism of drug action, study of natural processes, water cycle, temperature measurements.

- Stable isotopes for advanced nuclear reactors

: uranium nitride with

15

N as nuclear fuel,

157

Gd for reactor control.

In spite of some difficulties of stable isotopes use, especially related to analytical techniques, which are slow and expensive, the number of papers reporting this subject is steadily growing as well the number of scientific meetings organised by International Isotope

Society and IAEA, Gordon Conferences, and regional meetings in Germany, France, etc.

Stable isotopes applications development on large scale is determined by improving of their production technologies, as well of labelled compounds and of analytical techniques.

11

12

S e c t t t i i i o n

A

I

I

I s s s o t t t o p i i i c p r r r o c e s s s s s s e s s s

O r r r a l l l p r r r e s s s e n t t t a t t t i i i o n s s s

13

14

TECHNIQUE AND INSTALLATION FOR

DEUTERIUM-DEPLETED WATER PRODUCTION

Gh. Titescu, I. Stefanescu

Institute of Cryogenics and Isotope Separation, P.O.Box 10, 1000-Rm.Valcea

(Romania), E-mail:

icsi@ns-icsi.icsi.ro

Deuterium-depleted water (DDW) production technique consists in the separation of deuterium from water through an continuos distillation process under pressure of about 133,3 mbar.

The water used as basic material has an isotopic content of 144 ppm D/(D+H) and can be demineralised water, distilled water or condensed-steam.

DDW result as distillate with an isotopic deuterium content of 15-80 ppm, depending on the level we want to achieve.

The process takes place in a plant consisting of one or two distillation column filled with structured packing, which was treated to improve their wetting properties by special chemical procedure.

The feeding is make at the bottom of the column, the installation functioning as depleting section referring at deuterium.

The quality of DDW, excepting the deuterium content, is similar to distilled water quality. Romania has the possibility to produce 2,000 tones of DDW/year.

To verify the deuterium content of DDW the mass spectrometry method is used.

DDW is used in making isotope standard and in the future, it is possible to use it as bioactive product for medical purposes, in pharmaceutical industry, agriculture and zootechny.

15

LITHIUM ISOTOPE SEPARATION

Ilie Hodor

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5, Romania

In this paper, the research made at INCDTIM concerning lithium isotope separation is summarised.

Natural lithium consists of two isotopes

6

Li (7.5 %) and

7

Li (92.5 %). Lithium isotopes have many uses but first of all, they are important materials for nuclear fusion. Up to the present time, nuclear fusion was used only in weapons but it is believed that the fusion power reactors will become a reality in the first decades of the following century.

In weapons, lithium is used both as a means for storing deuterium (DLi contains more deuterium per unit volume as liquid D

2

does) and as an essential fusion fuel. Furthermore, the main way to produce tritium is the reaction

6

Li(n,α)T. The countries which developed thermonuclear weapons developed technologies for the large scale

6

Li production. The separation technologies and production capacities are kept under secret.

In Romania, the domestic demand for lithium isotopes, used especially for research purposes, was of a few hundreds grams per year. This quantity was small but it could not be bought from foreign market because of embargo reasons. The decision was taken to achieve an installation capable to supply the domestic needs. In 1976, after a preliminary study, the isotopic exchange (1) between Li-amalgam and aqueous LiOH was chosen as basic reaction for the separation process.

6

Li

+

+

7

Li(Hg) ↔

7

Li

+

+

6

Li(Hg) (1)

The isotopic effect of this reaction at ambient temperature is ε=0.05. The multiplication of this effect by countercurrent exchange in a column has the advantage of simple refluxes but has the shortcoming that the side reaction (2) take place.

Li(Hg) + H

2

O = Li

+

+ OH

-

+ ½ H

2

(2)

Some years after our choice, it was disclosed that the same reaction (1) had been used in

United States in Colex process for large-scale

6

Li production. This coincidence is very interesting and it is possible that some other countries had used the same reaction.

Every separation unit based on the reaction (1) should have the same main components: 1) separation column, 2) electrolyser, 3) column for amalgam decomposition, and 4) evaporator. The technological solution for every of this components may differ from an author to another. It seems that for large-scale equipment some special packing columns were developed. In our case, the scale was small so that we used a spray column in which the aqueous LiOH moved up in an unpacked cylindrical tube and a fine spray of Li-amalgam fell down. This solution has some important advantages: a) favourable report between the velocities of reactions (1) and (2), b) great separation power density, c) small mercury inventory, and d) small equilibration time. The separation capacity of a column was 570 mol swu/year but we believe that a column with at least 200 times greater capacity may be realised.

In the last time, we have begun to consider some other separation processes based on

Li complexation and on the combination of Li complexation with electromigration.

16

STUDY OF

13

C SEPARATION BY ISOTOPE EXCHANGE

13

C/

12

C

IN CO

2

- Di - n - BUTYL AMINE CARBAMAT/METHANOL

SYSTEM

S.Dronca, D.Axente, A.Bâldea, C.Teacă

National Institute for Research and Development of Isotopic and Molecular

Technologies, 3400 Cluj-Napoca 5, P.O.BOX 700, Romania.

The experimental data regarding

13

C separation by

13

C/

12

C isotopic exchange in CO

2

-

Di-n-butyl amine carbamat/methanol system, using two laboratory plants: a Pyrex glass, unit for atmospheric pressure and a stainless steel one for measurements at pressure, are presented.

At atmospheric pressure the concentration increase of DNBA-Methanol solution from

1 M.l

-1

to 2 M.l

-1

has not a significant influence on the height equivalent to a theoretical plate, unlike solution of DNBA in Heptan, where at 2 M.l

-1

a 67% decrease of HETP was observed.

The pressure increases from 0.1 MPa to 0.2 MPa determined diminution of HETP for 1 M.l

-1 and 2 M.l

-1

solution of DNBA in Methanol at 25 and 5

0

C. The isotopic transfer between two phases, circulated in counter current in the separation column, is improved at higher pressure according to increased carbon dioxide concentration in the amine solution.

HETP of 5.02 cm for 2 M.l

-1

DNBA in Methanol at 1.4 mM carbamat.cm

flow rate recommends this system for

13

C separation on commercial plant.

-2

.min

-1

17

TIME-OF-FLIGHT MASS SPECTROMETER FOR FULLERENE

AND RECOIL IONS: DESIGN AND CONSTRUCTION

Dana Dumitriu * , D. Ioanoviciu **, C-tin Ciortea *, Z. Szilagyi*, Gh. Baciu**,

N. Gligan**

*”Horia Hulubei” National Institute for Nuclear Research and Engineering,

P. O. Box MG-6, Bucharest-Magurele, Romania

** National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5, Romania

The time focusing of the fullerene ions and of those recoiling from a target bombarded by high energy particles is a task complicated by both the initial space and velocity distributions of these ions. Instead, to use a drift space geometry that offers limited focusing capabilities a geometry including an electrostatic mirror with one stage was selected. As the interaction region is wide and the angular opening of the ion packet extracted from the collision chamber is big after mass spectrometric standards, a 231 mm inner diameter was chosen for the mirror electrodes. The mirror was built-up from 32 20 mm long stainless steel ring electrodes fastened by screws and insulating pieces to three dural supports. The flight tube was constructed from two equal length sections of 888 mm length each and 314 mm inner diameter. This tube houses most of the instrument's main assemblies. The collision (scattering) chamber will be attached at one end of the flight tube. The another one will allow the access to the mirror assembly. Here it will be possible to locate a detector assembly for the detection of neutrals or to receive ions directly from the source when the mirror is grounded. Between the collision chamber and the mirror a beam centring and deviating device will be mounted. Its task is to correct the unexpected ion deviations from the prescribed path due to machining inaccuracies or due to charging up effects. The mirror assembly will be mounted in such a way that it will be able to accept ion packets directed with a 2.5

o

degree incidence angle. The reflection inside the mirror of 639 mm longitudinal depth is to be fitted to a 2360 mm total field free path before reaching the detector. The detector assembly was constructed from a stack of electrodes and grids kept at the appropriate distances by alumina insulators. This assembly contains channel plates in a chevron configuration.

Tolerances 2 10

-2

mm were kept during the machining of most components. The entire mass spectrometer will be mounted on a support to rise the mass spectrometer mean plane to the level of the accelerated particle beam.

18

INAA INVESTIGATION OF MAJOR AND TRACE ELEMENTS

VERTICAL DISTRIBUTION IN LACUSTRINE SEDIMENTS

FROM THE DANUBE DELTA

L.C. Dinescu, O.G. Duliu

*

, N.G. Mihãilescu

**

Institute of Physics and Nuclear Engineering “Horia Hulubei”, Mãgurele, P.O.

Box MG - 06, RO - 76900, Bucharest, Romania

*

University of Bucharest, Mãgurele, P.O. Box MG - 11, RO - 76900, Bucharest

**

Geological Survey of Romania, 1, Caransebes str. RO - 78344, Bucharest

By using the Instrumental Neutron Activation Analysis (INAA), the vertical profile of 4 major (Na, K, Ca and Fe) and 21 trace (Rb, Cs, Ba, Sc, La, Ce, Sm, Eu, Tb, Yb, Lu, Hf, Th,

U, Ta, Cr, Co, Zn, As, Sb and Br) elements have been determined in sedimentary cores collected from three lakes (Lung, Mesteru and Furtuna), all of them located in the fluviolacustrine part of the Danube Delta. All determinations have been performed in correlation with the radiometric measurement of the 137Cs vertical distribution as well as sediments dry bulk density. The last category of data allowed us to determine the sedimentation rate, and thus to reconstruct the geochronology of four potential polluting elements, i.e. Zn, As, Sb and

Br.

A previous lithologic study has showed a great similarity between the Lung and Mesteru lakes sediments, both of them being classified as lacustrine in opposition with the Furtuna lake whose sediments presented a significant fluvial character.

The major elements present a relatively uniform trend, irrespective to the sediments origin. In the case of trace elements, we noticed some peculiarities about the Rare Earth Elements

(REE) vertical distribution. Therefore, the total REE versus Sc diagram as well as REE normalised to the Upper Continental Crust (UCC) concentrations, in spite of their relatively similitude, presented different pattern for Lung and Mesteru lake sediments on one hand and

Furtuna lake on the other. The La to Th ratio presented, in the limit of experimental errors, close values to 3.25 characteristic for the UCC. All these data pledges for a continental origin of the investigated sediments.

As, Sb and especially Zn presented maximum concentrations beneath the upper sediment surface. Based on these values as well as on the sedimentation rates determined from the

137

Cs vertical profiles, the time evolution of above elements concentrations have been reconstructed for the last seventy years. By analysing these results, it results that the pollution process became more significant at the and of years ’50s and beginning of ‘60s. By starting with the first years of the last decade of this century, this process has marked a relatively regression.

All these modification could be connected with the industrial activity of the Central and

Eastern European Countries which begun to increase by the end of the ‘50s till the end of

‘80s when slowly declined. This fact can also be correlated with the decrease of the industrial activity of the same countries, as a consequence of the recent political changes.

19

CONTROL AND DATA ACQUISITION SYSTEMS FOR

LABORATORY ANALYTICAL INSTRUMENTATION AND

EXPERIMENTS

M. Kaucsar, D. Vonica, H. Bendea

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5, Romania

In laboratory instrumentation and also in physics or in chemistry experiments, the computerised control and data acquisition systems allow man - instruments or man - experiments interfaces to be translated to a much higher level of human intelligence than before microcomputers was extended in so large number. Because in physics or in chemistry fields we deal with complex processes, where useful information results after acquiring and analysing large sets of data, the use of personal computers (PC) is not only recommended but is indispensable. In fast processes is useful to combine the features of PC’s with that of distributed programmable microsystems. Distributed processing provide us speed and better reliability. Depending on the requirements, a compromise between speed and reliability could be accomplished with an adequate hardware and software engineering. Providing the instrument or the experimental system with detectors and actuators it become possible to close feedback loops.

Interfacing the physical or chemical process with an PC or an distributed programmable microsystem is one of the most demanding step in whole system development.

Data from detectors and sensors could be analogic or digital. Analogic signals will be transformed in digital form using a/d converters. These informations are processed in PC and used to control the actuators. In the case of analogic actuators, the control signal results after an d/a conversion.

The PC is the master and the distributed microsystems are the slaves in this controlling scheme. Communication between them is usually implemented upon international standards such as serial communication standards EIA/TIA - 232-E, RS-485 or the instrumentation standard GPIB IEEE488. It is possible to use bi-directional data transmission with the LPT printer port, but only with EPP (Enhanced Parallel Port) or ECP (Enhanced

Capability Port) type.

The software comprises the following components: data acquisition and local control routines which are implemented on distributed microsystems; communication routines between PC and distributed microsystems; main program running on PC intended to coordinate the distributed microsystems and global control loops; processing of the acquired data to implement a friendly man - instrument interface.

20

235

U ENRICHMENT BY CHEMICAL EXCHANGE

IN U

4+

- UO

2

2+

SYSTEM USING ION EXCHANGE RESINS

R.C.Horga, D.Axente, A.Pamula, A.Bâldea, C.Fătu, M.Leucă

I.Ilieş , D.Ursu, C.Floare

National Institute for Research and Development of Isotopic and Molecular

Technologies, 3400 Cluj-Napoca 5, P.O.BOX 700, Romania.

The experimental data on

235

U enrichment by isotopic exchange

235

U/

238

U in U

4+

-

UO

2

2+

system on cation exchange resin C-100, produced by Purolite, and in the system U

4+

-

[UO

2

Cl x

]

2-x

, on anion exchange resin Dowex-1, Sigma, are presented. In both cases, a thermostated glass column of 2 m height and 10 mm i.d., was utilised. Cation exchange resin was passed in R-Ti

3+

form, then the column was fed with 0.047M UO

2

Cl

2

solution. At the boundary between the resin, in R-Ti

3+

form and UO

2

Cl

2

solution, the reaction that takes place is:

UO

2

2+ sol

+ 2Ti

R

3+

+ 4H

+

U

R

4+

+ 2Ti

4+ sol

+ 2H

2

O

(1) where

sol

and

R

represent solution, respective resin phase.

According the isotopic exchange between U

4+

fixed on resin and UO

2

2+

from solution:

235

U

4+

R

+

238

UO

2

2+ sol

238

U

4+

R

+

235

UO

2

2+ sol

(2)

235

U is enriched in the solution phase at the front of U band, and

238

U in the resin phase at the rear of uranium band. The uranium solution, which has passed through the column, was fractionated, by means of an automatic sample collector LKB, in 100 small fractions. For each sample fraction uranium content, and uranium isotopic ratio

235

U/

238

U were determined.

In the case of Dowex-1 the resin was converted in R-Cl form with 5M HCl solution, then 0.1M UO

2

Cl

2

solution in 5M HCl was loaded in the column, and on the resin were fixed the following complex anions: [UO

2

Cl

3

]

-

, [UO

2

Cl

4

]

2-

. When all resin was passed in R-U(IV) form, the column was fed with 0.1M TiCl

3

solution in 5M HCl.

At the boundary between TiCl

3

solution and R-U(VI) form resin the reactions that take place are:

[UO

2

Cl x

]

R

2-x

+ 2Ti

3+ sol

U

4+ sol

+ 2TiOCl

4

2-

R

+ (x-8)Cl

-

[

238

UO

2

Cl x

]

R

2-x

+

235

U

4+ sol

[

235

UO

2

Cl x

]

R

2-x

+

238

U4

+ sol

(3)

(4) and

235

U will be enriched in the resin phase, at the rear edge of uranium band (4).

The effluent from the bottom of the column was collected in small fractions on which uranium content and isotopic ratio

235

U/

238

U were determined. All isotopic analyses were performed on SMIT-1 thermal ionisation mass spectrometer.

Using the same feed flow rate the

235

U enrichment was about 60% less on cation exchange resin in U

4+

-UO

2

2+

system than on anion exchange resin in U

4+

- [UO

2

Cl x

]

2-x system. The eluent volume, until the uranium

235

U enrichment is attained, was 1428 ml on cation exchange resin, and 692 ml on anion exchange resin. TiCl

3

solution concentration is about 7 times bigger in cation exchange experiment than on anion exchange resin. Tacking into account this data, we conclude that for

235

U enrichment U

4+

- [UO

2

Cl x

]

2-x

exchange system on anion exchange resin has significant advantage.

21

SYNTHESIS OF

15

N ,

13

C LABELLED PURINES

Maria Chiriac, D. Axente, N.Palibroda

National Institute for Research and Development of Isotopic and Molecular

Technologies, 3400 Cluj-Napoca 5, P.O.BOX 700, Romania.

The heteronuclear NMR spectroscopy in the structural analysis of proteins and nucleic acids requires labelling with

15

N and

13

C. These NMR studies using oligonucleotides, specifically labelled with

15

N and

13

C, may provide valuable informations regarding nucleic acid structure, drug binding and nucleic acid-protein interaction.

For this purpose, in the last years we prepared some purines labelled with

15

N and

13

C in different positions, which were asked by Institute Pasteur from Paris, where the labelled purines will be use in enzymatic syntheses of nucleotides -

15

N,

13

C.

This paper presents

15

N and

13

C labelling of the following purines:

1) [6 -

15

N] ADENINE

It was obtained by amination of 6-chloropurine with

15

NH

3

at high pressure and temperature.

2) [1,3,7 -

15

N, 8 -

13

C] XANTHYNE

The experimental procedure is an adaptation of the synthesis method for the corresponding unlabelled compounds (the Traube method, modified by Bobransky and

Synowiedsky). As starting isotopically labelled material we used CO(

15

NH

2

)

2

, Na

15

NO

2

and

H

13

COOH.

3) [1,3,6,7 -

15

N, 8 -

13

C] ADENINE

Because of the possibility to transform purines one into another, we prepared labelled adenine in the mentioned positions, using [1,3,7 -

15

N, 8 -

13

C] xanthyne as starting material.

The

15

N - labelled compounds, CO(

15

NH

2

)

2

, Na

15

NO

2

and

15

NH

3

, used as starting material for labelling of these purines, were obtained from H

15

NO

3

99 at. %

15

N, produced at the National Institute for Research and Development for Isotopic and Molecular

Technologies, Cluj-Napoca, Romania.

The labelled purines structure was confirmed using mass spectrometry, IR spectroscopy, NMR spectroscopy and the isotopic label was determined by mass spectrometry on the molecular compounds.

22

THE H/D ISOTOPIC EXCHANGE USED FOR SURFACE

DYNAMICS OF Ni SUPPORTED CATALYSTS STUDY

Mihaela Lazăr, V. Almăşan

National Institute for Research and Development of Isotopic and Molecular

Technologies; O.P. 700, 3400, Cluj Napoca

The hydrogen – deuterium (H/D) isotopic exchange was performed between D

2

gas and the hydrogen binding from oxide surface of six supported nickel catalysts (Ni /Al

2

O

3

,

Ni/Cr

2

O

3

, Ni/MgO, Ni/SiO

2

, Ni/ZnO, Ni/ZrO

2

). The catalyst samples were prepared by coprecipitation method.

The experimental investigations were made in a typical reaction system for transient experimentation, which consist in a catalytic reactor on line with a quadrupole mass spectrometer (QMS).

In every case, the isotopic exchange reaction follows the same way: the input gases

(D

2

) pass through the catalytic reactor, and the output gases are continuos monitored by

QMS. Isothermal isotopic exchange was carried out between 20 o

C and 300 o

C. In all these cases, the isotopic exchange reaction takes place with a significant rate.

The H/D exchange phenomenon is principally based on the reaction:

D + OH = H + OD

In our experiments we were interested to measure, the strongly adsorbed hydrogen kinetics desorption curves in an isothermal system at seven different temperatures. In all cases, it can be observed a high increase of desorbed hydrogen quantity with decrease of temperature, which means that the OH populations from the oxide surface are influenced even by the low variation of temperatures.

We can say that the spillover hydrogen determines on oxide surface two kinds of processes:

a continuous exchange between spillover hydrogen species and hydrogen

population from oxide surface a significant variation of hydrogen population with temperature

It seems to be reasonable to suppose that the movable bonds between adsorbed hydrogen and nickel surface are maintained on the oxide surface, too. It is very likely that spilt over hydrogen achieve adsorption bonds with oxygen surface from the oxide, up to the individual OH formation.

The rate determining step of process would be the hydrogen transfer from the metal to the support (spillover step) and not the H/D isotopic exchange reaction.

23

THE RARE GAS ISOTOPES USED IN GEOPHYSICAL STUDIES

C. Cosma

1

, O. Cozar

1

, V. Znamirovschi

1

, D. Ristoiu

1

and Elena Mastan

2

1

University “Babes-Bolyai” Cluj-Napoca, 3400 , Ro

2

Informatic High School “Tiberiu Popoviciu”, 3400 Cluj-Napoca, Ro

Rare gas isotopes are largely used in many studies regarding the different aspects of the geophysical and geochemical processes happened at geological and cosmological time scale.

In the Herculane Spa area (South –Western part of Romania) there is a long and deep fissure following the Cerna river canyon as well as many transversal fissures. The geothermal water sources (springs), always accompanied by large amounts of gases, are met where these fissures cross. The presence of granite rocks at the surface is another remarkable characteristic of this area. Between 1980-1990 a series of measurements were made, especially as regarding the helium concentrations in the gases emanated from these geothermal sources. Nitrogen and methane are the main components of emanated gases, and high helium and radon concentrations were also found .

The composition of the gases was determined by using a Dempster mass spectrometer, and the radon from gases (together with the rate of exhalation from the ground) was determined by gamma spectrometry. The argon isotopes were analysed by means of a quadrupole mass spectrometer (AMP-4).

Near transversal fissures, the radon exhalation rates have higher values compared to the other measurements in this area. The ratio

4

He/

20

Ne > 400 is a very good indicator of the fact that these gases are pure (they do not contain atmospheric air) and they become from depth. The ratios

4

He/

40

Ar and

40

Ar/

36

Ar suggest that the helium in these sources may have a not negligible part of primordial helium arising from the earth mantle. Still, only the ratio

3

He/

4

He can make the difference.

Table 1. Isotopic ratios for gases from Cerna and Mehadica Valleys

Ratio

4

He/

20

Ne

(

4

He/N

2

).10

2

4

He/

40

Ar

(

40

Ar/N

2

).10

2

40

Ar/

36

Ar

38

Ar/

36

Ar

Neptun

> 400

1.25

0.95

1.05

333

0.2

Abator

> 400

1.09

S.C.D.

*

> 400

0.45

1.1

1

0.33

1.38

344 301

- 0.18

*

Sapte Calde Dreapta

Mehadica

> 400

1.15

1.1

1.04

280

0.18

24

THE CAYALYSIS H

2

-HDO ISOTOPIC EXCHANGE ON

HYDROGEN ABSORBING ALLOYS

P. Mărginean, D. Lupu, A. R. Biriş

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5, Romania

Hydrogen absorbing alloys are known to act as heterogeneous catalysts for reactions involving gaseous hydrogen like hydrogenations and H/D isotopic exchange. The mechanism by which these alloys are activated for hydrogen absorption from gaseous phase, isotopic exchange, various chemical reaction or electrocatalytic processes is the “in situ” formation of metallic nickel clusters finely dispersed onto different oxides resulting from the major oxidable components: La, Zr, Ti of the hydrogen absorbing alloys. These alloys are usually:

LaNi

5

, TiNi, or Laves phase (Zr,Ti)M

2 type structure with M-transition metal substituted with different other elements. The resulting matrix is thus Ni/oxide support, similar to the well known heterogeneous catalysts obtained by chemical ways (coprecipitation, impregnation).

The isotopic exchange H

2

/HDO is a useful tool for obtaining informations about the mobility of the adsorbed hydrogen on these catalysts. The rate for the isotopic exchange reaction:

H

2

+ HDO

HD + H

2

O measured for alloys of the three types of the compounds mentioned above are reported in

Tab. 1.

Tab. 1. The specific activity (r g

) for the isotopic exchange between H

2

and HDO heterogeneously catalysed by hydrogen absorbing alloys:

Alloy

LaNi

4.75

LaNi

5

Ti

1.5

Cu

MnNi

4.2

Al

0.8

TiNi

Catalytic activity r g x10

8

, mol HD/gs

58

17

27.2

1.4

ZrV

0.5

Ni

1.5

ZrV

0.5

Ni

1.3

Cu

0.2

ZrCr

1.1

Ni

ZrV

0.5

Ni

1.3

Ag

0.2

105

1400

100

3200

The measured isotopic exchange rates depend not only on the alloy structure, but also on the substituents, which sometimes result in highly increased exchange rates as observed for silver. The nature of this effect is discussed on the basis of the measured surface area of the activated alloys. The rates normalised to the surface area show that the major factor is the different increasing rate of the surface area after the activation treatment.

25

LONG TERM MEASUREMENTS OF TRITIUM AND

RADIOCARBON IN ENVIRONMENTAL COMPONENTS IN

ROMANIA

Augustin TENU, Florin DAVIDESCU

National Institute of Meteorology and Hydrology, Sos. Bucuresti-Ploiesti 97,

71552 Bucharest

Related to the hydrogeological research, INMH began the tritium measurements in

1969 and the radiocarbon ones in 1977.

This paper deals only with the measurements of tritium and radiocarbon in environmental components (meteoric waters and atmospheric CO

2

). For these two radioisotopes, Romania owns today continuously monthly series measurements of 28 and respectively, 7 years.

Tritium and radiocarbon activity determinations were made by liquid scintillation technique; for tritium, previous electrolitical enrichment was applied to water samples while for

14

C, the Na

2

CO

3

obtained from air sampling was converted into benzene.

Tritium measurements in meteoric water started in 1970 at 5 stations and they let us know the local concentration level, some particularities related to territorial distribution and useful conclusions about inter-correlation degree with other world-wide stations. The individual values of 500-600 T.U. recorded in 1970 decreased until background values today. This trend was interrupted by small accidentally increases.

The systematic radiocarbon measurements in atmospheric CO

2

started in 1992 and have continued at 1-2 stations. These measurements provided a better knowledge of the level, variability and radiocarbon evolution trend in geographical and meteoclimatic conditions of the Carpathian zone. Also, by the antropogen CO

2

identification and its quantitative appreciation, these determinations could be very useful to greenhouse effect evaluation.

By this isotopic database, any artificial incipient pollution could be easily identified even for background level concentrations. This is the reason for choosing Cernavoda station for tritium and radiocarbon determinations in water and air, monitoring started before and is continuing after the moment of nuclear power plant operation.

26

S e c t t t i i i o n

A

I

I

I s s s o t t t o p i i i c p r r r o c e s s s s s s e s s s

P o s s s t t t e r r r s s s

27

28

DETERMINATION OF NITROGEN UTILISATION

COEFFICIENT BY OAK PLANTS FROM MUNICIPAL SEWAGE

SLUDGE USING

15

N

Ariadna Alexandrescu, M Dumitru, D.M.Motelică, Doina Plaxienco,

Eugenia Gamenţ, Elisabeta Dumitru, Nicoleta Vrânceanu, I.Calciu,

*)

Ioana Prodan,

*)

N Prodan.

Research Institute for Soil Science and Agrochemistry, Bucharest

*) Agricultural Research Station, Teleorman

The research carried out indicated the possibility of applying sewage sludge on agricultural lands, for efficient use of its content in organic matter and nutrients and for emptying the storage places. The main restriction is the tendency of increasing the contents of heavy metals in soil and plant.

The sewage sludge used in the experiments was taken from the waste water treatment plant of Pitesti.

Research was organised in an experimental field with irradiated and non-irradiated sewage sludge on a Haplic Phaeozem, using oats as test crop

The experiments were set up in the field according to a complete randomised block design with 10 treatments: 100 kg N/ha from 1% a.e.

15

N labelled fertiliser; 20 kg N /ha from 10% a.e.

15

N labelled fertiliser; non-irradiated and respectively irradiated sewage sludge equivalent to 100, 200, 300, 400 kg N/ha + 20kg N/ha from 10% a.e.

15

N labelled fertiliser.

The application of sludge did not cause significant changes in soil chemical characteristics.

The nitrogen utilisation degree from the fertilisers applied was low and decreased with the dose of sludge applied. However, there was a tendency of increasing this utilisation degree in the case of irradiated sludge application.

The conditions for the agricultural use of irradiated sewage sludge are indicated. It is also emphasised its influence on soil fertility, agricultural production and yield quality, under the conditions of environmental protection.

Key words

: irradiated sewage sludge,

15

N labelled fertiliser, utilisation degree of nitrogen.

29

THE ETHANOL DEUTERATION BY CATALYTIC

REDUCTION OF ACETONITRILE

V. Almăşan, Mihaela Lazăr, Andreea Gluhoi, P. Mărginean, Judith Bartalis

National Institute for Research and Development of Isotopic and Molecular

Technologies; P.O. 700, 3400, Cluj Napoca

The total deuterated alcohol production is not a very easy problem because in these kind of molecules there are different type of hydrogen: one kept by the hydrocarbon radical and another, more active, in OH.

In the isotopic exchange process (the most utilised method for deuterated compounds production) the H/D isotopic exchange reaction rates are very different. A total deuteration process takes place only at high temperature where dehydrogenolysis reaction become significant.

For these reasons, the method proposed by us utilises deuterated row materials: acetonitrile.

The method has two different steps:

1.

the CN group is reduced either with Na in alcohol (R-OD), or with molecular deuterium in heterogeneous catalysis ( Ni/oxidic support).

2.

the CD

3

-CD

2

-ND

2

resulted in the previous process is then transformed into the

CD

3

-CD

2

-OD in the diazotation reaction.

The main reactions that take place are:

CD

3

-CN

CD

3

-CD

2

-ND

2

CD

3

-CD

2

-OD

Our work present the experimental results, which are obtained in the study of the processes, mentioned above. In conclusion is presenting the practical method to produce the total deuterated ethanol.

Another part of this work presents the analytical methods necessary to estimate and characterise the reaction’s development. The final product is chemical and isotopic analysed.

30

THE CORRELATION BETWEEN REACTION

MECHANISM AND THE ISOTOPIC EFFECTS IN CHARGE

TRANSFER AT SYSTEMS IMPLYING DEUTERATED

METHANES

P. Ardelean

National Institute for Research and Development of Isotopic and Molecular

Technologies, 3400 Cluj-Napoca 5, P.O.BOX 700, Romania.

The charge transfer reactions data are very useful in understanding phenomena in fields ranging from the study of high-atmosphere and astro-physics, to fusion plasma and mass spectrometry.

For a charge transfer process between a primary (reactant) ion AB

+

and a neutral molecule CX

4

(X being H or D) to take place, i.e.

AB

+

+ CX

4

AB + CX

+

4

The recombination energy (RE) of AB

+ secondary ion CX

+

4

should be close to the appearance energy (AE) of the

, i.e. that



= AE - RE should be a small quantity.

In the general case of asymmetrical charge transfer (

 

0) the energy needed can be provided either by transfer of energy from the relative kinetic energy of the ion molecule system or from the vibrational energy of the primary ion.

The measurements were carried out by using a perpendicular-type tandem mass spectrometer and a variable angle tandem mass spectrometer].

The charge transfer processes studied involved H

+

2

, CH

+

4

, CH

+

3

and N

+

as primary

(reactant) ions and CH

4

, CH

3

D, CH

2

D

2

and CD

4

as neutral molecules.

The secondary spectra were normalised and the relative intensities of CX

+

3

ions were used to calculate the intermolecular and intramolecular isotope effects,

π

i

and

 i

].

In all the systems, it was observed a variation of the relative cross sections versus the kinetic energy of the primary ions. This variation was relatively small (as for the systems H

+

2

- CH

4

and CH

+

4

- CX

4

) or it was quite important (as for the systems CH

+

3

- CX

4

and N

+

-

CX

4

). However, in all the cases, the intermolecular and intramolecular isotope effects (

π

i

and

 i

) show a more important variation of the values versus the kinetic energy. From this reason, the isotope effects could be used as a more efficient parameter for the charge transfer reactions path.

The reaction mechanism was derived from the experimental results. A modification of this mechanism is very probable for primary ion energies under 15 eV. This modification was also supported by the study of the momentum transfer measurements in the formation of

CX

+

3

secondary ions.

Conclusions were also obtained concerning the conversion of kinetic energy into internal energy in charge transfer reactions, for CX

+

3

ions containing more D atoms.

31

SYNTHESIS OF

15

N DOUBLE LABELLED UREA

A.Bâldea, S.Dronca, C.Teacă, D. Axente

National Institute for Research and Development of Isotopic and Molecular

Technologies, 3400 Cluj-Napoca 5, P.O.BOX 700, Romania.

Synthesis of double

15

N labelled urea by reacting

15

N - ammonia with elemental sulphur and carbon monoxide in a pressure vessel is presented.

15

NH

3

was produced by H

15

NO

3

reduction with Dewarda alloy in alkaline solution, or by nitric monoxide reduction with hydrogen on metallic manganese.

An average yield of 85% tacking into account

15

N - urea and

15

N-ammonium sulphate, produced in the same time, and 99% urea purity (checked by I.R. spectroscopy and mass spectrometry) were obtained.

15

N SEPARATION IN THE NITROX SYSTEM UNDER

PRESSURE

D.Axente, A.Bâldea, C.Teacă R.Horga, M.Abrudean

National Institute for Research and Development of Isotopic and Molecular

Technologies, 3400 Cluj-Napoca 5, P.O.BOX 700, Romania.

The basic isotope exchange reaction responsible for the separation of

15

N in Nitrox system is that between gaseous nitrogen oxides and aqueous nitric acid with single stage separation factor

= 1.055 for 10 M.l

-1

nitric acid, at 25

0

C and atmospheric pressure.

The rate of nitrogen isotope exchange between NO and HNO

3

has been measured as a function of nitric oxide pressure 0.1 - 0.4 MPa for 1 and 2 M.l

-1

. It is concluded that

15

N/

14

N exchange rate in NO-HNO

3

system has a linear dependence of NO pressure as indicated by rate measurements at different NO partial pressure and constant overall pressure, by adding helium in reactor. Using the rate law: R = [HNO

3

]

2

[N

2

O

3

] the

15

N/

14

N exchange rates for nitric acid concentrations 1.5 - 10 M.l

-1

were calculated.

In order to know what happens in

15

N separation at higher pressure, when the isotopic transport between two phases is improved, a stainless steel laboratory experimental plant with

1000 mm long x 18 mm i.d. column, packed with triangular wire springs 1.8 x 1.8 x 0.2 mm was utilised.

At 0.15 MPa and 2.36 ml.cm

-2

.min

-1

flow rate HETP was 7% smaller than at atmospheric pressure and 1.5 times smaller flow rate. HETP at 3.14 ml.cm

-2

.min

-1

flow rate and 0.18 MPa is practically equal with that obtained at atmospheric pressure and 2 times smaller flow rate.

The operation of the

15

N separation plant at 0.18 MPa, instead of atmospheric pressure, will permit doubling of the 10 M.l

-1

nitric acid flow rate and of

15

N production of the given column.

32

THE ISOTOPE EFFECT IN GADOLINIUM AMALGAM

SYSTEM

D.Axente

(a)

, M.Nomura

(b)

, Y.Fujii

(b)

(a)

National Institute for Research and Development of Isotopic and Molecular

Technologies, 3400 Cluj-Napoca 5, P.O.BOX 700, Romania.

(b)

Tokyo Institute of Technology, Research Lab for Nuclear Reactors

O-okayama, Meguroku, Tokyo 152, Japan

Gadolinium is a neutron absorbing material and has been used as a burnable poison contained in the U fuel pellets for LWRs. Among the 7 isotopes of gadolinium,

157

Gd has a special large neutron absorption cross section of 254,000 barn (10

-24

cm

2

).

In this paper gadolinium isotope separation factor for isotopic exchange between Gd

3+

(in solution) and gadolinium amalgam (GdHg) is determined.

By electrolyse of aqueous solutions containing gadolinium acetate and lithium citrate, as complexant agent, using the ratio [Li

+

]/[Gd

3+

] = 12, gadolinium amalgam was prepared using a glass electrolyser with Hg as cathode and platinum as anode.

The gadolinium amalgam was stirred with HCl solution 1-2N and Gd

3+

is precipitated as oxalate at weak acid pH and then converted to Gd

2

O

3

. The remained gadolinium in acetate solution (after electrolyse) was also precipitated as oxalate and converted to Gd

2

O

3

.

On Gd

2

O

3

samples the isotopic ratios

156

Gd/

160

Gd were determined by mass spectrometry, using MAT 261 equipped with a thermal ionisation ion source.

Between Gd

3+

and Gadolinium amalgam there is an isotopic exchange, the heavy isotope

160

Gd was found to be enriched in Gd

3+

and the lighter isotope,

156

Gd, was enriched in

GdHg.

The single stage separation factor

(

156

Gd/

160

Gd) was determined in different experimental conditions: contact time between Gd

3+

and GdHg, the yield of GdHg formation, current density.

The range of the measured values of

was 1.0013 - 1.00456, average value being

1.0023 at 26

0

C. The yield of GdHg formation has increased from 37-75.5% for the electrolyser of 40 mm i.d. (S = 12.56 cm

2

), to 89.6%, for electrolyser of 53 mm i.d. (S = 22 cm

2

).

After 30 minutes of contact (in electrolyse conditions) between Gd

3+

and GdHg there is not an important passage of Gd between the two phases, in these conditions the isotopic exchange of Gd is studied

.

33

ANALYSIS OF CAR EXHAUST AND FLUE GASES

BY GAS-CHROMATOGRAPHY COUPLED WITH SOFTWARE

C.A.Nicolae, V.Stanciu, Claudia Sisu

National Research Institute of Cryogenics and Isotopic Technologies

P.O.Box 10, Rm.Valcea, Code 1000, ROMANIA

Phone: 004 050 / 733890, Fax: 004 050 / 732746

An extensive experimental research has been carried out by gas-chromatographic runs in order to identify the most suitable adsorbents and define the best operating conditions for analysis of car exhaust and flue gases.

.

The gas-chromatographic apparatus used is composed of a STANG 200 dual type gaschromatograph equipped with flow divisor, carrier flow rate controllers, a thermal conductivity detector (TCD), and a PC with software.

The best separation of gases was obtained by using in the GC-System of Molecular

Sieve 5A and Porapak Q + Porapak R columns. For example, the car exhaust gases contain

(vol.%): N

2

=85.456; CO

2

=3.829; CO=6.146; O

2

=4.024; H

2

=0.054; CH

4

=0.033; C

2,3...

=0.037;

H

2

O=0.410 and the flue gases contain (vol.%): N

2

=59.58; CO

2

=33.80; CO=4.18 and O

2

=2.43

MESO –

TETRAPHENYLPORPHIN – 21, 23 D.

SYNTHESIS, ANALYSIS, COMPARISON TO 21, 23 – T –

PORPHIN

Corina Simion*, Cristian Postolache*, Maria Sahagia*, Calin Deleanu**

* NIPNE Bucharest – Magurele

** "C. D. Nenitzescu" Institute for Organic Chemistry, Bucharest

Meso –

tetraphenylporphin – 21, 23 – D has been obtained starting with unlabeled porphin synthesised from pyrrole and benzaldehyde. The final oxidation of tetraphenylchlorin to porphin was carried out with DDQ 0.5 equiv., 0.5 h at room temperature. Porphin was labelled by mechanical stirring in closed vessel in deuterated chloroform: deuterated water system at various concentrations.

NMR spectra proved the structure of synthesised compounds as well as the influence of H substitution with D at different D

2

O concentration. Kinetic study and assignments of the labelling positions were used in order to establish the optimal synthesis condition for the corresponding T labelled compound.

The final specific activity was 43 mCi/mmol porphin.

34

[

15

N] ALKYLTHIOUREA; N' – ACYLATED

DERIVATIVES

Corina Simion*, Cristian Postolache*, Calin Deleanu**, Catalina Barna*

* NIPNE Bucharest – Magurele

** "C. D. Nenitzescu" Institute for Organic Chemistry, Bucharest

The study on phenylthiourea derived thioureides behaviour as efficient scavengers for the radical species at certain tissues level lead to series of unlabeled and C-13 labelled derivatives synthesis. The actual stage regards introduction of thiol – thione equilibrium and the labelling on other positions in such molecules. The labelled compound synthesis started from potassium phtalimide with

> 99% at. %

15

N. The labelling position was pointed out through isotopic effects induced by

N-15 replacement of N-14 in

1

H – NMR spectra.

PHENYLTHIOUREA DEUTERATION. REACTION OF

DEUTERATED COMPOUND WITH DPPH

Corina Simion*, Cristian Postolache*, Călin Deleanu**, Cătălina Barna*

* NIPNE Bucharest – Magurele

** "C. D. Nenitzescu" Institute for Organic Chemistry, Bucharest

Phenylthiourea was certified as a useful scavenger towards radicals in unaqueous, anhydrous media. It completely reacts with DPPH at room temperature within two minutes.

The reaction products were isolated by L.C. The main product is 1,1 – diphenyl – 2 – picryl hydrazine. In order to establish the mechanism of the reaction and detection of phenylthiourea derived products, was obtained the corresponding deuterated product starting from phenylthiourea and > 99.9% D

2

O in CDCl

3

.

1H – NMR, checked up the positions of isotopic exchange.

35

OPERATION ANALYSIS OF THE

DEUTERIUM DEPLETED WATER PILOT PLANT

Cornelia Croitoru, Tiţescu Gheorghe, Irina Saroş

National Institute of Research-Development for

Cryogenic and Isotopic Technologies, ICSI Rm. Vâlcea

The first stage of the distillation pilot plant for the heavy water final concentration has been utilised for the deuterium depleted water production. Now the installation is fed in bottom of de second column with water of 144 ppm D/(D+H). The product of the plant, extracted at the top of first column, must be of 30 ppm D/(D+H), maximum.

Simulation of steady state functioning of this plant has permitted to establish the separation capacity in the plant operation conditions and the internal fluids flow that provides a significant increase of the plant production.

Based on unsteady state functioning simulation it has been established the evolution of plant production concentration in the period of setting in operation and after the changes of plant operation regimes. It also has been analysed the influence of thermal feed state on the plant performances.

CARBON AS CATALYST SUPPORT IN THE

PURIFICATION

PROCESSES OF THE GASES

Elena David

National Research Institute of Cryogenics & Isotopic Technologies

P.O.Box 10,Rm.Valcea, Code 1000, ROMANIA

Tel.: +40 50 732744; Fax: +40 50 732746

The application of carbon in catalysis is mainly as support for active phases in various reactions. Beside a wide variety of noble metal-carbon systems for hydrogenation reactions, the large scale applications are in the gas purification processes. An important application of carbon supported oxides of silver, copper, chromium, cobalt, is as active mass in filters for toxic gases. In all catalytic synthesis applications, the carbon is considered as a support with little reactivity towards sensitive molecules with reactive functional groups which would be activated by acidity of an oxide substrate.

This paper presents the so-called weak metal-support interaction that was mentioned in a comparative study on metal-support interactions for copper particles. The preparation conditions were chosen such that gasification of the support had not occurred. The extremely valuable advantage of an inert substrate consequently has the disadvantage that the active phase is difficult to anchor on the surface. The methods of introducing the active phase into carbon support, the dispersion of the metal, the influence of the treatment conditions on state of the metal and the regeneration possibilities for the Cu/C, CuO/C catalysts are presented and discussed.

36

THE USE OF RADON ISOTOPES IN RETROSPECTIVE

EXPOSURE EVALUATION

C. Cosma

1

, I. Chereji

2

,D. Ristoiu

1

, I. Pop

3

1

University Babes-Bolyai, Faculty of Physics, 3400 Cluj-Napoca, Ro

2

Institute of Isotopic and Molecular Technology, 3400 Cluj-Napoca, Ro

3

Technical University, 3400 Cluj-Napoca, Ro

Many retrospective studies regarding the long time exposure to radon (

222

Rn) are based on the accumulation of

210

Pb (T

1/2

=22y) on the surface of glass objects or other materials and measuring the specific alpha activity of

210

Pb (T

1/2

=138 d, E

=5.3 MeV) resulted by implanting of radon daughter

218

Pb, due to the alpha recoil.

In the case of thoron (

220

Rn), this method is not applicable because there is not a long live time isotope which to allow an important accumulation of any descendant. The longest live time of the thoron descendants is

212

Pb with a live time of T

1/2

= 10.6 h. But the study involving the thoron daughters implanted at surface of glasses or other materials (plastic, wood, paper, polyethylene, plexiglass and Cu or Al foils) can be useful in simulation of the radon progeny implantation by considering of several changes in the aerosol particle distribution and following the intensity modification of alpha or gamma peak intensities. This simulation is possible due to the equilibrium of implantation, which is obtained in short time

(about 50 h) comparatively with about 100 y in the case of

222

Rn. The alpha spectrometry method was recently applied to measure the thoron contribution in the case of integrating track-etched detectors used for thoron monitoring.

The purpose of this work is to obtain the alpha and gamma spectra (especially alpha) for thoron and radon daughters implanted at surface of different materials and to show the possibility of this method to simulate the radon progeny implantation and thus to find some parameters used in the Jacobi model. For measurements, we used a PIPS detector of Canberra type (900 mm

2

) with 25 keV energy resolution and a NaI(Tl) scintillator for gamma counting.

The samples were obtained by exposure of our materials in a thoron vessel ( 0.2 l) containing

200 g Th(NO

3

)

2

5H

2

O. In the case of radon exposure an uranium ore (pitchblende) can be used The first results shoved that these alpha spectra can be obtained and that the width of alpha peaks depends on materials. The constant of implantation is estimated for all used samples. This constant is two-three times higher in the case of glasses comparatively with metallic samples.

37

MEASUREMENT AND CONTROL SYSTEM OF THE

CRYOGENIC PROCESS FOR TRITIUM SEPARATION USING

SCXI 1100

Carmen Maria Retevoi, Mihai Culcer, Ion Cristescu, Mariana Iliescu

National Research Institute for Cryogenics and Isotopic Technologies, C.P. 10,

1000 Rm. Vâlcea, Romania

A data acquisition system for controlling the cryogenic process for tritium separation was developed. It was studied specially the unsteady-state of heat transmission in heat exchanger of a refrigerant cycle, for different hydrodynamic states in various geometry.

The "virtual device" which we design is used for data acquisition and control of the cryogenic system, which processes the cryogenic flow in 4 - 30 K range.

With the most popular signal conditioning product line, SCXI 1100 and DAQ hardware

AT-MIO-16-XE-10 from National Instruments, we perform the multi-channel acquisition at

DAQ rates. Analogue inputs modules interface the system to a variety of transducers (PRTs,

CRTs) and signals from the installation, improving the quality and reliability of the measurements.

We chose signal conditioning owning the following advantages: electrically isolation, transducers interfacing, signal amplification, filtering and high-speed channel multiplexing.

The system, which uses LabVIEW software and DAQ hardware, is used to control the cryogenic process of tritium separation.

We use a personal computer, LabVIEW software, DAQ board and SCXI-1100 signal conditioning to acquire, control and display test data from Cryogenic Plant for Tritium

Separation (Fig.)

Sensors from installation

Block diagram of the data acquisition system

38

ISOTOPIC EFFECTS IN SEPARATION THROUGH

ALUMINUM OXIDE MEMBRANES

G.Mihailescu, S.Pruneanu, S.Kreibik

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5, Romania

One of the first method used at the separation of stable isotopes, was the separation from gaseous phase, through a porous membrane. The aluminium oxide membranes can be used in this process, because they have a porous structure, with parallel pores, having the diameter (nm) almost equal with the applied voltage (V).

For the preparation of such porous membranes, we have used various acids: sulphuric, oxalic and phosphoric. We have concluded that the best membranes are those prepared in sulphuric acid, having the pore diameter of 20 nm. We have measured the permeability of these membranes at hydrogen and deuterium. The measurements were performed at room temperature, using a pressure difference across the membrane of 760 torr. We have obtained a medium separation factor of

1.4, which is very close to the theoretical factor, 1.41.

Due to the good stability in time of these membranes ( they are not affected by the ambient humidity), we have obtained the same results after a period of 6 months.

ELECTRO-SPREADING OF DIELECTRIC LIQUID

DROPS ON SOLID SURFACES

St. Kreibik, St. Popescu, C. Neamţu, Gh. Mihăilescu

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5, Romania

The role of different parameters affecting the stability and spreading of dielectric liquid drops subjected to electric field is presented.

The estimate of the effect of the electric field as well as of the parameters that influence the spreading of the drops was made by the help of sessile drop method using powder-based colloids (TiO

2

and ZnO) mixed with siccative linseed oil.

We called this spreading under the influence of the electric field as electro-spreading.

Our aim in this paper is to provide an understanding of the qualitative influence of the relevant parameters, rather than to verify a quantitative formula.

39

DEUTERIUM DISTRIBUTION REGULARITIES IN

PRECIPITATION.

V. Feurdean, Lucia Feurdean

National Institute for Research and Development of Isotopic and Molecular

Technologies, 3400 Cluj-Napoca 5, P.O.BOX 700, Romania.

Deuterium measurements from precipitations were initiated by dr. L. Blaga in Natural

Isotopic Abundances department from ITIM since 1971. Systematic measurements of deuterium content and precipitations quantities were carried on after 1975.

Deuterium measurements from precipitations were emphasised the succession of minimum values corresponding to cold seasons and maximum values corresponding to warm seasons. Other minimum and maximum values having lower amplitude than those corresponding to seasons are recorded for each season, too. As a rule, minimum values recorded during the summer months are the consequence of the cold air masses penetration and maximum values recorded during the winter months are the consequence of the warm air masses penetration.

For the north-west part of Romania including the Cluj-Napoca area, the winter precipitations come prevalently from the north-west direction (from Greenland and North of

Atlantic Ocean). The maximum values of deuterium content recorded during winter months are due to the displacements of warm and humid air masses from south-western Europe

(Mediterranean Sea).

During long-time, (over 22 years) the monthly mean values of deuterium concentrations from precipitations for each year show amplitude variation of the minimum and maximum values. These maximum and respectively minimum values are oscillatory with a variable period of few years (from 2 to 6 years). The variation of the oscillation period suggests at least two causes having different and fixed periodicity.

The determinations of deuterium concentration from precipitations reveal the existence of natural isotopic label process for all natural waters. This phenomenon is adequate for the use of deuterium as a natural tracer in hydrologic studies. The isotopic hydrology ads new information to the hydrologic data base.

The correlation between isotopic data base for precipitations and meteorological information will provide a new method for long time prognosis.

40

STUDY OF UNDERGROUND WATERS FROM NORTH-

EASTERN DOBROUDJA KARST BY USING DEUTERIUM AS

NATURAL TRACER. CASE STUDY.

Lucia Feurdean, V. Feurdean

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5, Romania

The objectives of the present paper are to determine the distribution of deuterium - as the one of the environmental isotope - in the land of the vicinity of the Danube Delta Ecosystem and to establish the hydrological processes that induce the deuterium distribution and have a direct bearing on the preservation of the dynamic balance of groundwater system in order to avoid excessive water intrusion from/to Danube Delta Reserve Biosphere and/or leakage of the possible pollution water into the overlying freshwater aquifers or into the water of Reserve Biosphere.

The isotopes tracer method was used to determine: the origin of the groundwater, the recharge and discharge areas for groundwaters, interrelation between Danube river waters and groundwater in porous and karstic aquifer, hydrological interrelation between various groundwater sources, the dynamics and the flow paths of the groundwaters.

Measurements of deuterium content, the temporal variations of the deuterium content, the correlation of the deuterium content with the total dissolved salt content show that the waters are meteoric in origin, but at the some time the results showed that two sources could not originate from local groundwater and must have their recharge area at high altitude and a considerable distance.

According to the

-80‰) that represent most probably the intrusion of isotopically light water from high altitude sites through network of highly

 permeable karst channels during discharge

Waters tributary to Danube River that have small variability in time. There are some samples from residential fountains and from springs, that perceive the influence of water

Local meteoric waters with high variability in time. The extend of deuterium variability for these water samples is controlled by seasonal effects

Waters that reflect the mixing of isotopically light water with heavier isotopically waters

(local infiltration waters and waters tributary to Danube river).

The sets of isoconcentration lines for the deuterium content have been the analytical tools for the analyses of the groundwater flow. The spatial distribution of average of between the variation in space and time indicates that the study area is divided in four hydrological subareas.

The North part of the study area appears to act as a discharge area both for the water from high altitude and for the local infiltration waters.

The second is part of Southwest for that flow paths have a local character and the extend of deuterium variability is controlled by seasonal effects.

The third is the phreatic system that recharges from the Danube river and flow paths are towards Southeast (direction of Danube flow). The sink Colina of Tulcea-Colina syncline affects the flow direction of the phreatic and the swallow water discharge in Colina zone, too.

The last is the conduit aquifer and mixed aquifer of two water types endmembers: isotopic heavier waters and isotopic light waters. The advance of isotopic light water front is influenced by heterogeneities in geologic materials and the average linear velocities of the water vary due to various types of heterogeneities. The waters originated in mixing processes discharge in the northern part of Razelm Lake, below the level of the lake’s water.

41

EXPERIMENTAL PLANT FOR OXYGEN ISOTOPES

SEPARATION BY CRYOGENIC DISTILLATION OF NITRIC

MONOXIDE

Mihai Gligan, Aristotel Rãdoi, Simion Dronca, Daniela Radu, Damian Axente,

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5, Romania

The heavy isotope of oxygen,

18

O, is used as a labelled compound in many scientific fields such as: agrochemistry, geology, metabolic studies. One of the most used method for

18

O separation is the cryogenic distillation of nitric monoxide at 121 K.

The single stage separation factor (

) for

18

O is 1.035 - 1.045 at 120 - 110 K.

A

18

O separation plant by cryogenic distillation of NO was built in the Separation Laboratory of ITIM Cluj-Napoca.

The nitric oxide used as a feed gas for the isotopic waste gas of the

18

O separation was obtained from the

15

N separation plant in operation at ITIM Cluj-Napoca, which contains 76% NO.

Because large quantities of liquefied NO at 121 K are circulated in the plant, the feed gas must be extremely pure. A NO purification plant was used. It has an absorber and several adsorbers, which remove the greatest amount of NO

2

, H

2

O and N

2

. The purity of the nitric oxide obtained was 99.99%. Finally, a cryogenic distillation column was used for high purification and the resulting gas was stored in tanks.

The main components of the experimental plant for the distillation of nitric monoxide at 121 K are: the NO condenser, distillation column, boiler and thermal insulation.

The condenser provides the reflux at the top of the column by NO total liquefaction at 121

K. It is necessary to maintain this temperature, using as primary refrigerant liquid nitrogen at

77 K. The method developed for our plant is the use of oxygen as an intermediate refrigerant, boiling at the desired temperature. The column is 7.1 m high and 16 mm inside diameter. It is filled with Helipack type packing 1.8 x 1.8 x 0.2 mm. The column has several locations for feed lines, sampling lines, pressure and temperature control. The boiler is electrically heated.

In order to have an effective thermal insulation, the plant has a vacuum jacket. Inside it, the column and other plant components were wrapped in multi-layers of aluminised plastic foils, as radiation shields. A vacuum of 10

-5

mm Hg was obtained.

The purpose of these experiments was to obtain the separation data and to evaluate the height equivalent to a theoretical plate (HETP). In this respect, the plant was repeatedly operated up to 91 hours. Samples from the top and the bottom of the column were taken.

Mass spectrometry isotopic analyses were performed directly on NO.

The optimum dynamic hold-up was found to be 190 - 200 ml liquid NO, which provides a column flow rate of 1.2 ml / cm

2

min. All the experiments used fixed quantities of gas, without continuous feed or waste withdrawal. The minimum calculated number of plates is

114.

On the distillation packed column of 7.1 metres length and 16 mm inside diameter, at

1.2 ml / cm

2

min flow rate, HETP was 6.22 cm for Helipack type packing 1.8 x 1.8 x 0.2 mm.

42

13

C ENRICHMENT BY CRYOGENIC DISTILLATION OF

CARBON MONOXIDE ON EXPERIMENTAL PILOT PLANT

Aristotel Rãdoi, Mihai Gligan, Simion Dronca, Damian Axente

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5, Romania

The isotope

13

C is used in many scientific fields such as: biology, medicine, chemistry and environment studies. The recent advances in analytical techniques have determined an important demand for this isotope. The most used method for

13

C separation in large quantities is the cryogenic distillation of carbon monoxide at 81 K.

The single stage separation factor (

) for

13

C is 1.01 - 1.007 at 70 - 81 K.

A

13

C separation plant by cryogenic distillation of CO was built in the Separation Laboratory of ITIM Cluj-Napoca.

The carbon monoxide used as a feed gas for the

13

C separation plant was produced by reaction of CO

2

with charcoal at 1300 K. CO was purified in a plant which has a reactor filled with Pd/Al

2

O

3

and adsorbers with 5A molecular sieve. The purity of the carbon monoxide thus obtained was 99.9%. A cryogenic distillation column was used for high purification and the resulting CO, with less of 10 vol. ppm H

2

O and CO

2

, was stored in tanks.

The main components of the experimental plant for the distillation of carbon monoxide at 81

K are: the condenser, a cascade with two distillation columns, boilers and thermal insulation.

The condenser provides the reflux at the top of the first column by total liquefaction of CO vapours at 81 K. The used refrigerant is liquid nitrogen. The first column is 2.5 m high and

26 mm inside diameter. It is filled with Helipack type packing 2 x 2 x 0.2 mm. The reflux at the bottom of the first column is provided by an electrically heated boiler. The second column, 4.25 m high and 16 mm inside diameter, is filled with Helipack type packing 1.8 x

1.8 x 0.2 mm and has also an electrically heated boiler at the bottom.

The columns have several locations for feed lines, sampling lines, pressure and temperature control.

Inside the vacuum jacket, the low temperature components were wrapped in multi-layers of aluminised plastic foils, as radiation shields. A vacuum of 10

-5

mm Hg was obtained.

The purpose of these experiments was to obtain the separation data and to evaluate the height equivalent to a theoretical plate (HETP). In this respect, the plant was repeatedly operated up to 108 hours. Samples from the top and the bottom of the first column and from the bottom of the second column were taken.

Mass spectrometry isotopic analyses were performed directly on CO.

The optimum dynamic hold-up was found to be 375 ml liquid CO, which provides a flow rate of 4 - 4.5 ml / cm

2

min in the columns.

The plant was operated in batch conditions at total reflux, without feed or waste withdrawal.

On the first column of 2.5 metres length and 26 mm inside diameter the minimum value of

HETP was 19 mm and for the second column of 4.25 meters length and 16 mm inside diameter, the minimum value of HETP was 22 mm, both at 4 - 4.5 ml / cm

2 min flow rate.

43

CATALYTIC HYDROGENATION OF CARBONYL

GROUP FOR DEUTERATED COMPOUNDS PRODUCTION

Andreea C. Gluhoi, P. Mărginean, Diana Lazăr, V. Almăşan

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5, Romania

The total deuterated isopropyl alcohol can be produced starting from acetone. The developed technology comprises two steps:

1.

Deuteration of acetone by H/D isotopic exchange between acetone and heavy water in homogeneous catalysis.

2.

Reduction of the deuterated acetone with deuterium in presence of a metal/support catalyst.

H/D isotopic exchange reaction of the H atoms from CH

3

groups is easy to occur because carbonyl group weakens C-H bond (ceto-enolyc tautomery). The big difference between boiling points of acetone and water permits an easy separation of acetone by distillation method.

The reduction of acetone with deuterium was performed in a dynamic reactor by passing a deuterium flow saturated with acetone vapour through a supported nickel catalyst bed. The reaction products were analysed on-line using a flame ionisation detector.

The supported nickel catalysts were checked for this reaction. By using nickel over different supports the selectivity for isopropyl alcohol was about 100%. The propane was detected only as traces. The catalytic activity depends strongly on the support nature: the

Ni/SiO

2

is less active, while the Ni/TiO

2

presents the larger value for the intrinsic activity.

44

CARACTERIZATION OF SUPPORTED NICKEL

CATALYSTS BY H/D ISOTOPIC EXCHANGE

Andreea C. Gluhoi, P. Mărginean

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5, Romania

Metal catalysts are usually dispersed onto oxide supports in order to achieve a high metal surface area and to become more stable to the sintering during the reduction and the catalytic process. The nature of the support can have a significant effect on the catalytic properties of the metal for certain reactions. In this communication, the results concerning the influence of some oxides of lanthanides on the activity of nickel catalysts in the deuterium exchange reaction between hydrogen and water vapour are reported.

For this purpose, the nickel catalysts supported on Yb

2

O

3

, Gd

2

O

3

, Ho

2

O

3

, CeO

2

, Y

2

O

3 and La

2

O

3

were prepared by coprecipitation method. The resulted precipitate was washed with doubly distilled water in order to remove the Na

+

and NO

3

-

ions, calcified in flowing nitrogen at 330

0

C, and reduced in the flowing hydrogen at 350

0

C. The total surface area of the samples was measured by krypton adsorption (BET method) and the dispersion of the metallic nickel from the hydrogen uptake measured by the temperature programmed desorption .

The total specific area value of the catalyst samples, resulted from the physical adsorption of the krypton, increases with increasing of the atomic number of lanthanide of the support oxide. The metal dispersion, calculated from the hydrogen uptake, is practically independent of the nature of the support oxide.

The kinetic measurements show that the specific catalytic activity, i.e. the activity per gram of sample, as well as the intrinsic activity, i.e. the activity per metallic area unit, decrease with increasing of the atomic number of the lanthanide from the support oxide.

The results presented in this communication can be interpreted in the range of a

Langmuir-Hinshelwood mechanism, in which reaction takes place between hydrogen dissociated on the metallic surface and water molecule activated by support surface. Our hypothesis is that at the metal-support interface are created new catalytic centres more active than those of the nickel black. On the other hand, from the literature data, it is known that the alkalinity of the lanthanide oxides increases with increasing of the atomic number. In conclusion, from the experimental data presented here, results that the hydroxyl groups from the metal-support interface participate at the activating of the water molecule and the new centres created are more active when the supports are stronger acid.

45

NAPHTHALENE-

-D

Postolache C*, Simion Corina*, Chiper Diana*, Deleanu I**, Ionica M***,

Creţu Gh***

* National Institute for Physics and Nuclear Engineering “Horia Hulubei”,

CPR Department, PO Box Mg-6, Bucharest-Magurele, R-76900

** Organic Chemistry Institute “C D Nenitescu” Bucharest

*** Army Center for Medical Research Bucharest

Deuterated naphthalene is used as internal standard in GC-MS analyses.

Naphthalene -

-D was synthesised by hydrolysis of naphthil magnesium bromide with D

2

O of 99,97 % nuclidic purity in an anhydrous atmosphere. Grignard reagent was obtained by reaction between fresh distilled

-Br naphthalene and magnesium in ethyl ether solution.

The organic solvent was distilled under low pressure and crude deuterated naphthalene was purified by double recrystallisation from ethanol and sublimation. Obtained product was characterised by NMR and IR spectrometry.

Isotope effects in IR spectra were also analysed. Specific peaks of naphthalene-

-D were identified at 410, 1030-1080, 1490, 1600, 1950-2350 cm

-1

-D at 435, 542 and 594 cm

-1

were not evidenced.

, while those of naphthalene-

IONISATION DETECTORS BY IRRADIATION

I. Coldea I. Toma

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5, Romania

In any ionisation detection system, the electrical charges in the system increase at the detection moment. Moreover, the detectors provide conditions enabling the collection and measurement of electric charges, avoiding, as much as possible, the recombination or ion multiplication phenomena, which cause response and linearity anomalies.

On the contrary, the electron capture detector provides operating conditions to favour the ionic recombination phenomena.

Its response mechanism starts with the capture of the free electrons from the molecules to be detected and finishes with a fast process of neutralisation of the ions formed.

At the detection moment, the charges present in the detector decrease proportionally to the concentration of the substance to be analysed and its specific degree of electroaffinity.

This study presents an electron capture detector with

emission of Tritium adsorbed on

Titanium (100mC), which operates in “D.C. Mode”.

Our study concludes that the “D.C. Mode”, even providing positive results in several cases, is not able to exploit all the potential sensitivity and selectivity of the electron capture detector.

46

TIME-OF-FLIGHT MASS SPECTRA FROM ION

PACKETS GENERATED ON THE FRONT OF DEFLECTING

PULSES

D. Ioanoviciu, C. Cuna, A. Pamula, N. Palibroda, V. Cosma, St. Kovacs,

St. Popescu, M. Kaucsar, B. Erdelyi, L. Sarkozy, D. Ursu, P. Ardelean

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5, Romania

A procedure to generate ion packets from a continuous beam is to "chop" portions from it with trapezoidal electric pulses. Usually, this is obtained on the flat top of the almost trapezoidal pulses. The ion packet length is limited to the length of the pulse flat top. To overcome this limitation, the beam is swept by an increasing (and decreasing) electric field across a slit located after the deflector. This method allows, by using generators of arbitrary length, to generate ion packets of extremely short length. A simple, approximate relationship was derived to estimate the ion packet dimensions from the deflecting device geometry and the applied impulse front steepness.

A drawback of this packet generating method is the presence at the detector of two mass spectra, roughly displaced in time by the length of the applied pulses. However, to examine a portion of the spectrum, the length of the pulses can be so tuned to eliminate the superposition of the significant mass peaks.

The length of the ion packets thus produced is not influenced by the turn-around time and they can be efficiently focused by electrostatic mirrors. The ion beam deflection induces also some contribution to its longitudinal dimension. The effect is under investigation, both theoretically and experimentally. The ion packet production by deflection was applied in a first stage on a linear time-of-flight mass spectrometer of 1370 mm drift space. Next, a single stage electrostatic mirror was used to ensure ion energy focusing.

As the sweep speed is high, only a small percentage of the produced ions is effectively used in the analysed packets. In the future, an increase of orders in magnitude of this efficiency is expected from an impulse operated ion source from a synchronised floating potential generator.

47

RADIPROTECTORS ACTION ON CHROMATIN

RADIOLYSIS, STUDIED BY STEADY STATE AND TIME-

RESOLVED FLUORESCENCE

Irina Radulescu

1

, Liliana Radu

1

, Doina Gazdaru

2

, V. Preoteasa

1

1

Molecular Genetics Department, V. Babes Institute, Spl Independentei 99-101,

Bucharest 76201;

2

Biophysics Department, Faculty of Physics, Bucharest

University, Bucharest, Romania

In this paper, we attempt to characterise the effect of radioprotectors glutathion and cysteamine on the chromatin radiolysis induced by fast neutrons action.

The chromatin was extracted from Wistar rat livers and irradiated (10-100 Gy) with fast neutrons, obtained by the reaction of 13.5 MeV deuterons on a thick Be target at an IFNE

U-120 Cyclotron. A specific DNA ligand, proflavine, which binds only to undamaged DNA, has been used. The fluorescence spectra were measured with a fluorescence spectrophotometer and the fluorescence decay profiles were recorded on a time-correlated single photon counting fluorometer.

The fast neutrons modifications in chromatin proteins structure were studied by the analysis of the chromatin tryptophan intrinsic fluorescence; the lesions are related to a decrease in the Trp quantum yield. The treatment with radioprotectors diminishes this effect.

On fast neutrons action, the relative fluorescence intensities (the ratio for the irradiated chromatine-proflavine complexesto that of free ligand) increase, showing the DNA lysis produced. The presence of radioprotectors determines a decrease of the fluorescence intensities.

From the time-resolved spectroscopy, we obtained fluorescence decay profiles that were fitted to double exponential functions by the method of iterative convolution. Proflavine has in unbound state a 4.8 ns lifetime, and in bound state to chromatine 0.9 ns lifetime. The radioprotectors presence at irradiation determines an increase of the relative contribution of the excited state lifetime of bound ligand.

Steady state and time-resolved fluorescence measurements of the chromatin radiolysis in radioprotector presence permit an exact evaluation of the DNA damage in chromatin.

These results may constitute useful indications in combined therapy.

48

IMPROVING THE ACCURACY OF ISOTOPE RATIO

DETERMINATION BY STATISTICAL TREATMENT OF DATA

A. Pamula, C. Floare, M. Vermesan

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5, Romania

In a research concerning the study of the separation of uranium isotopes on ion exchanging resins, the problem of very precise isotopic analysis appeared. The existing instrument is a thermal ionisation mass spectrometer built in our institute in 1986. It is equipped with a two filaments ion source and a single ion collector based on a secondary electron multiplier.

In 1986, during the homologation procedure, the accuracy was established to be 1% from the measured value. The aim of this work is to overpass this instrumental limitation.

The measuring error occurs through the superposition of several causes:

Variations of the ion current supplied by the ion. While measuring contribution of the

235

U

+

ion current, the total ion current intensity may differ from the same intensity, while the

238

U

+

ion current is collected.

Isotopic effects on evaporation: the lighter isotope is evaporating faster than the heavier one. So the isotopic content of the vapour faze may not be representative for the isotopic content of the solid sample.

The diffusion of the ion beam on the residual gas in the mass spectrometer vacuum produces the superposition of an unknown fraction of the

238

U

+

ion signal over the

235

U

+

signal.

The electronic measuring chain produces electrical noise

Complex software for the data acquisition and processing was elaborated in order to decrease the importance of these effects. The results are showed in the figure.

0.735

0.73

0.725

Figure 1: The

235

U (%) content in different

0.72

0.715

samples of uranium after a separation experiment.

0.71

1 2 3 4 5 6

The accuracy obtained by the proposed analytical method is sufficient to put in evidence separation effects.

49

CHROMATOGRAPHIC SYSTEM FOR CONTROL AND

OPTIMISING OF CHEMICAL PROCESS

G. Popeneciu, G. Maniu, H. Bendea

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O. Box 700, 3400 Cluj-Napoca 5, Romania.

In many industries branches such as chemistry, oil chemistry, food, drugs or nuclear activities, chemical process monitoring and optimisation have great importance in order to obtain maximum output.

For an optimal adjust of the chemical process it is essential to have information in line

(real time), from many measuring points, reliable data and powerful analysis tools.

The paper present a system who have the capability to extract gaseous samples directly from technological fluxes in a number of maximum eight points, without any gas loses and without interrupt the process. Those samples are automatically selected (one from eight in any given order) and feed in analysis module. Output data are immediately disposable as paper chart or at an PC console.

Based on this data, the process master could make complex analysis and take decisions for optimising the process. The system could be also integrated in an automatic adjust loop.

The system is composed by :

1.

circuit selector for sample extract

2.

probe injection module

3.

analysis module

4.

command and data processing unit (PC)

50

SOLVENT DELIVERY SYSTEM FOR HPLC

G. Popeneciu, G. Maniu, H. Bendea

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5, Romania

High performance liquid chromatography (HPLC) is the most powerful of all the chromatographic techniques. It can often easily achieve separations and analyses that would be difficult or impossible using other forms of analytical techniques. The variety of compounds that are now analysed by HPLC is enormous, ranging from substances containing only a few atoms to polymers having 100000 or more, and ionic to totally apolar substances.

In HPLC, the quality of the solvent delivery system determines the quality of the analytical results. If reproducible results are required, the solvent delivery pump must provide flow stability better than 1% for all flow rates, gradients, solvents and column back-pressure.

The model SLS100 is a high performance solvent delivery system designed specially for liquid chromatography applications. Constant flow of the solvent delivery is achieved with a pair of specially driven positive-displacement pumping chambers. Flow rate is selectable in 0.1 ml/min increments from 0.1 to 9.9 ml/min.

The maximum output pressure is 400 bars, with the over-pressure limit adjustable from 10 to 420 bars.

Because of the low internal volume of the model SLS100, solvent change over time is minimised and recycle operations is permitted. For example, each piston in the pair of pumping chambers only displaces 100

 l of solvent per stroke.

Electronic control of piston reciprocation rate governs the solvent flow rate. Solvent viscosity and system elasticity can be automatically compensated to ensure a steady solvent flow.

51

UV DETECTOR FOR HPLC

G. Popeneciu, G. Maniu, H. Bendea

National Institute for Research and Development of Isotopic and Molecular

Technologies, P. O. Box 700, 3400 Cluj-Napoca 5, Romania

During the past fifteen years, high performance liquid chromatography (HPLC) has become one of the major analytical technique for the analysis of complex mixtures of chemical compounds, such as plant extracts, pharmaceutical formulations, or certain drugs in human body fluids. In the course of this successful history, all components of the liquid chromatograph contributing to instrument performance underwent rapid development. In recent years, special emphasis has been placed on the detector area, because this part of the system, which monitors the separated compounds of a mixture, strongly contributes to the selectivity and sensitivity of the analytical method.

A good compromise, offering medium to high sensitivity combined with excellent selectivity, signal stability, and easy handling, is the UV/Vis absorbency detector. This detector is based on determining the absorbency of unknown mixture of chemical compounds that flow in detector’s cell.

Detector signal is proportional with cell geometry and operating condition and also with compound concentration so both, qualitative and quantitative analysis could be made.

Our detector DUV100 is an absorbency type with double beam. The radiation source is an D

2

lamp that provide light with wavelengths between 190 and 700 nm. Wavelengths selection is accomplished with optical filters. The beam is large enough to illuminate both, analysis and reference camera, eliminating the need of a light splitter. The absorbency is measured with a pair of photodiodes sensible in UV/Vis domain.

The photodiodes signal is amplified and the ratio of direct beam (reference) and absorbed beam is calculated with an logarithmic and antilogarithmic circuit.

For better separation of compounds the cell volume is very small - 12,5

 l and materials in contact with liquid are stainless metal, teflon and quartz glass for minimum contamination and low corrosion.

52

MIDAZOLAM-D-G

Postolache C*, Simion Corina*, Ionica M**, Cretu Gh**, Deleanu C***, Rusea

Dana****

* National Institute for Physics and Nuclear Engineering “Horia Hulubei”,

CPR Department, PO Box MG-6, Bucharest-Magurele, R-76900

** Army Center for Medical Research Bucharest

***Organic Chemistry Institute “C D Nenitescu” Bucharest

**** Institute of Public Health Bucharest

Midazolam (8 – chloro – 6 (2 – fluorophenyl) – 1 – methyl - 4H – imidazo [1,5 - a]

[1,4] benzodiazepine) was identified to be a good internal standard in GC-MS analyses. Due to the possible existence of midazolam in human biological samples under analysis, the use of deuterated product is required.

Midazolam was deuterated by isotope exchange technique using palladium catalyst in

D

2

O solution, when general deuterated product was obtained.

Different catalytic systems were tested and Pd/BaSO

4

-10% in D

2

O of 99,97 % nuclidic purity in the presence of small quantities of D

2

was selected.

Deuterated derivatives were extracted from aqueous solution using

CH

2

Cl

2

:CHCl

3

:C

2

H

4

Cl

2

(1:1:1 v/v) mixture and analysed by TLC, GC-MS and NMR technique.

53

EXPERIMENTS REGARDING ORGANISM'S

BEHAVIOR UNDER DEUTERIUM-DEPLETED WATER

INFLUENCE

I. Ştefănescu, D. Steflea, Gh. Tiţescu,

Institute of Cryogenics and Isotope Separation, P.O.Box 10, 1000-Rm.Valcea

(Romania), E-mail:

icsi@ns-icsi.icsi.ro

Deuterium-depleted water(DDW) is represented by water that has an isotopic content smaller than 145 ppm D/(D+H).

The role of naturally occurring D in living organisms was examined by using DDW instead of natural water. The DDW significantly decreased the growth rate of the L

929 fibroblast cell line, and also inhibited the tumour growth. These suggest that the naturally occurring D has a central role in signal transduction involved in cell cycle regulation.

Beginning 1996 Institute of Cryogenics and Isotope Separation, DDW producer, cooperated with Romanian specialised institutes for biological effect's evaluation of DDW.

These investigations lead to the next conclusions:

- DDW caused a tendency towards the increase of the basal tone, accompanied by the intensification of the vasoconstrictor effects of phenylefrine, noradrenalin and angiotensin; the increase of the basal tone and vascular reactivity produced by the DDW persist after the removal of the vascular endothelium.

- DDW stimulate immune defence reactions, represented by the opsonic, bactericidal and phagocyte capacity of the immune system, together with increase in the numbers of polymorphonuclear neutrophils.

- Animals treated with DDW showed an increase of the resistance both to sublethal and to lethal gamma

 radiation doses, suggesting a radioprotective action.

- Investigations regarding artificial reproduction of fish with DDW fecundated solutions confirmed favourable influence both in embryo growth stage and in resistance in next growth stages.

- One has studied germination, growth and quantitative character's variability at two genotypes of Avena Sativa; one can remark the favourable influence of DDW on biological process at plants in various ontogenetic stages.

54

CHEMICALLY MODIFIED GLASSES FOR ANALYSIS

OF HYDROGEN ISOTOPES BY GAS-CHROMATOGRAPHY

Vasile Stanciu, Doina Ştefănescu

National Research Institute of Cryogenics and Isotopic Technologies

P.O.Box 10, Rm.Valcea, Code 1000, ROMANIA

Phone: 004 050 / 733890, Fax: 004 050 / 732746

Hydrogen isotopes separation process by such method as cryogenic distillation or thermal diffusion method is one of the key technologies of the tritium separation from heavy water of CANDU reactors and in the tritium fuel cycle for a thermonuclear fusion reactor

[1,2]. In each processes, the analytical techniques for measuring contents of hydrogen isotope mixture are necessary.

An extensive experimental research has been carried out in order to produce the most suitable adsorbents and define the best operating conditions for selective separation and analysis of hydrogen isotope by gas-chromatography.

This paper describes the preparation of adsorbent materials utilised as stationary phase in the gas-chromatographic column for hydrogen isotopes separation and treatment

(activation) of stationary phase.

Modified thermo-resisting glass with Fe(NH

4

)

2

(SO

4

)

2

6H

2

O and Cr

2

O

3

respectively, have been experimentally investigated at 77K for H

2

, HD and D

2

separation and the results of chromatographic runs are also reported and discussed.

The gas-chromatographic apparatus used is composed of a Hewlett-Packard 7620A gaschromatograph equipped with a gas carrier flow rate controller and a thermal conductivity detector (TCD). The apparatus comprises also a Dewar vessel containing the separation column. The hydrogen isotopes H

2

, HD, D

2

and their mixture have been obtained in our laboratories.

The best operating conditions of the adsorbent column Fe (III)/glass and Cr

2

O

3

/glass, i.e. granulometry, column length, pressure-drop along the column, carrier gas flow rate, sample volume have been studied by means of the analysis of the retention times, separation factors and HETP.

55

SURVEY ON ISOTOPE EFFECTS AND SEPARATION

TECHNOLOGIES

Michel Couairon

(a)

, Stephen Goldstein

(b)

, Edgar Soulié

(c)

(a)

CEA/SACLAY, DCC/DPE, 91191-Gif Sur Yvette Cedex (France),

E-mail :

rousseau@carnac.cea.fr

(b)

CEA/SACLAY, DCC/DPE, 91191-Gif Sur Yvette Cedex (France),

E-mail:

rousseau@carnac.cea.fr

(c)

CEA/SACLAY, DSM/DRECAM, 91191-Gif Sur Yvette Cedex

(France),E-mail :

bsoulie@drecam.cea.fr

This paper is a review of the main industrial processes and physical principles used for stable isotope separation on a production scale. It will be restricted to “classical” industrial technologies. Roughly speaking, only three types of technologies have been contemplated for today’s production (apart from uranium enrichment, outside the scope of this review).

1.

-Chemical exchange processes for the lighter isotopes

D

,

T

,

7

Li

,

10

B

,

13

C

,

15

N

,

17

O

..

. Operating processes such as exchange distillation and liquid-gas chemical exchange are based on isotope mass-differences in the free energy (vapour pressures, vibration frequencies) of molecular species. Insight into statistical thermodynamics gives low enrichment factors

1 .

O

5

, which have generally a

m

/

m

2

ratio dependency. Although needing thousands of repetitive elementary operations, those low cost processes are well suited for large capacity production. Modern trends are now in solid-liquid chromatographic columns : polymer-crown complexes with large macrocyclic rings have topological ability to pick up boron, lithium, or caesium isotopes. Detritiation

(on a small scale) with palladium solid-gas interface is a special case.

2.

-Thermal Diffusion process for the production of light rare gases [

3

He

,

22

Ne

,

36

Ar

,

86

Kr

]. While having a low separation factor for each stage, this process is still of topical interest for production of the rare gases, with a high purity degree, and of

13

CH

4

at the gram level of yearly production.

3.

-Ultra

G

as

C

entrifuge (

G.C.

) for medium and heavy nucleides. This process is based on an increase of a small mass diffusion flux by a pressure gradient. Several counter-current thermal diffusion effects are added to reach higher separation factors

1 .

5

. The whole process results in a

m

dependency. That allowed low cost units to separate xenon as well as metallic isotopes.

The trend at Oak-Ridge and at the Kurchatoff-Institute is to replace the electromagnetic technique by

G.C.

for kilogram production of germanium, chromium, zinc or tungsten isotopes.

-For the near future, repercussions of laser research may occur in stable isotope production; they are extensively described in this meeting. Laser multistep AVLIS is a selective process developed for the nuclear fuel. Besides enriching

235

U

or depleting

242

Pu

, it may succeed as a powerful process for the separation of rare-earth absorbers, such as

157

Gd

or

167

Er

.

G.C.

could hardly be applied to the felements given that the volatility of the possible feed (diketonate) is very low. Ion Cyclotron

Resonance could be a challenger if active research were resumed. Infrared multiphoton dissociation

(IRMPD) has shown high separation factor and yield capacity, for several light species like boron tribromine, halogenated hydrocarbons, or silicon halides. Infrared tuning flexibility with a free electron-laser is a prerequisite to industrial developments. Single photon dissociation with ultraviolet wavelength was proven to be an efficient way to produce

13

C

from formaldehyde: enrichment factors higher than 35 have been reached at Saclay ( see Alain Petit’s abstract).

56

S e c t t t i i i o n

B

M o l l l e c u l l l a r r r p r r r o c e s s s s s s e s s s

O r r r a l l l p r r r e s s s e n t t t a t t t i i i o n s s s

57

58

SOLITONIC EXCITATIONS IN BIOLOGIC ONE-DIMENSIONAL

MOLECULAR SYSTEMS.

Dan Grecu, Anca Vişinescu, A.S. Cârstea

Institute of Physics and Nuclear Engineering,

Department of Theoretical Physics, Bucharest

Several models of self-trapping of energy in an harmonic one – dimensional molecular chains of biological interest are reviewed. Special attention is given to the models of Davydov and

Takeno, with a long range interaction (LRI) of Kac – Baker type (exponentially decreasing) included. Solitonic excitations are obtained in different limits and the influence of the LRI is investigated. The envelope solutions are studied in an approximation going beyond the usual non – linear Schrödinger equation.

59

THE EVOLUTION OF THE NATURAL MAGNETIC FIELD

ENVIRONMENT AND ITS SIGNIFICANCE FOR TERRESTRIAL

LIFE

V. V. Morariu

Department of Biophysics, National R&D Institute for Isotopic and Molecular

Technologies, 3400 Cluj-Napoca, P. O. Box 700,

E-mail: vvm@L49.itim-cj.ro

Complexity of the geomagnetic field:

The geomagnetic field (GMF) has been a witness of the apparition and evolution of life on our planet. It is a sort of a common belief that terrestrial life depends on the existing GMF although systematic investigations and development of adequate interpretation have never substantiated this idea. The starting point of this work is that GMF is not a constant environment: there are rapid fluctuations such as the magnetic storms lasting for one or several days; there are cyclic periods of increased geomagnetic activity coinciding with the 11 period solar cycles; also there are periods of tens of thousands to hundreds of thousands of years when GMF varies very little which is followed by polarity reversals. Such a magnetic polarity reversal (MPR) is accompanied by a period of thousands of years when the GMF is practically zeroed. The last MPR took place

780,000 years ago. It is estimated that ahead of us is a new MPR event, possibly to take place in about 1000-2000 years. GMF decreased from about 4 Gauss to 0,4 Gauss during the last

4000 years.

Role of GMF for terrestrial life:

We know from the field of biomagnetism that weak to moderate fields may influence in a complex way the living matter. In addition, we know that magnetic storms cause some serious health problems. Solar cycles modulate GMF so that life is influenced at individual and population levels on times of the order of a decade.

Further biological extinction seems to be correlated to MPR, which is a very dramatic claim.

Therefore understanding of the role of GMF is not a question with a simple linear response as far as the effect vs. strength of the field is concerned. We do not have a satisfactory picture of the hazard posed by the magnetic storms; we have an even less clear picture of what happens when MPR occurs. At present GMF is steadily decreasing and we do not know its biological consequences.

The SLOPE and the WELL effects:

Suppose the effect vs. magnetic field strength is a simple linear or monotonic relation. This is the simplest kind of an effect, which is proportional to the intensity of the cause. We may conveniently call this effect as a type of

SLOPE EFFECT. However we encountered a different type of effects which I will call as

WELL EFFECTS i.e. the effect is high at both ZMF and higher values than in GMF respectively. In other words, the plot: effect = f (field strength) has a minimum at the normal value of GMF. This might suggest that life is adapted to the present value of GMF and any values higher or lower than GMF represent a stress factor. However, the stress mechanisms must be different at lower and higher fields respectively. As GMF is steadily decreasing, it means that the terrestrial life is constantly exposed to a changing type of stress. We do not know which are the two different mechanisms or groups of mechanisms and how important is their reaction on a long term on the terrestrial life. Investigations in conditions of ZMF may help understand this problem.

60

ON SPECTRAL BEHAVIOUR OF SOME Ni(II) AND

CO(II) O-ALCHYL-DITHIOCARBONATES AND THEIR

ADDUCTS

Ionel Haiduc a

, Radu Florin Semeniuc a

, Rodica Grecu b

and Rodica Micu-

Semeniuc a a

“BABES-BOLYAI” University, Chemistry Department; b

Institute of Chemistry “RALUCA RIPAN”

Four adducts of cobalt(II) xanthates and eight adducts of nickel(II) xanthates were prepared and characterised by elemental analysis, thermal behaviour and electronic and vibrational spectra. The compounds have the general formula M(S

2

COR)

2

•L. For M = Co, R =

-CH

2

CH

2

OCH

3

and L = o-phenantroline, 4,4’-bipyridil, 2-aminopirazine and 2aminopirimidine. For M = Ni, R = -CH

3

, -CH

2

CH

3

, -CH(CH

3

)

2

and -CH

2

CH

2

OCH

3

and L = diphenylphosphinoethane. On the basis of elemental analysis we proposed the combination ratio for cobalt adducts 1 Co : 2 S

2

COR : 1 L and for nickel adducts two combinations ratio, 1

Ni : 2 S

2

COR : 1 L and 1 Ni : 2 S

2

COR : 0.5 L respectively. The thermal behaviour suggests that only Co(S

2

COCH

2

CH

2

OCH

3

)

2

•o-phen is monomeric, all others compounds are polymeric. In the same time, the thermal behaviour shows that the compounds christalizes with solvent molecules, water in the case of cobalt(II) compounds and metyl-ethyl-ketone in the case of nickel(II) xanthates. On the basis of electronic and infrared spectra of the compounds, a high degree of covalence is suggested. On the other hand, the electronic and infrared spectra confirm the monomeric structure of Co(S

2

COCH

2

CH

2

OCH

3

)

2

•o-phen and the polymeric structure of the other compounds.

61

THE FORMATION OF THE MASS SPECTRA BY THE

CHEMICAL IONIZATION TECHNIQUE

Z. Moldovan

1

, J. M. Bayona

2

and R. Alzaga

2

1

National Institute for Research and Development for Isotopic and Molecular

Technologies, 3400 Cluj-Napoca 5, P.O. Box 700, Romania.

2

Instituto de Investigaciones Quimicas y Ambientales de Barcelona, c/J. Girona

18-26, 08034 Barcelona, Spain

In the chemical ionisation (CI) mass spectrometry (MS) the ionisation of the substance of interest is effected by ion-molecule reactions rather than electron impact(EI) or field ionisation(FI). The CI spectrum is, usually, different from the spectra produced by other ionisation techniques and the analytical and scientific utility of the method stems from the unique character of the chemical ionisation spectra. By comparison , the molecular ions initially formed by EI processes are odd-electron ions, their decomposition is influenced by the presence of the odd electron. Obviously, the ions initially formed by even-electron CI processes may be expected to decompose by rather different networks of pathways. Another reason for difference is the fact that whereas in EI ionisation, the energy transfer distribution can include values with 10 eV above ionisation potential, the energy transfer in CI processes exceed only 5 eV. Therefore, by CI processes, it is possible to obtain complementary structural information.

The present paper discusses the CI mass spectra for a new family of aromatic amines, having methane as reactive gas, with general formula: R

1

-Ph-NH-Ph-R

2.

The compounds were isolated from some environmental samples by GC/MS technique.

The main reactions involved are:

R

1

-Ph-NH-Ph-R

2

+ CH

5

+

R

1

-Ph-N

+

H

2

-Ph-R

2

[M+1]

+

(proton transfer)

R

1

-Ph-NH-Ph-R

2

+ C

2

H

5

+

R

1

-Ph-HN(C

2

H

5

)-R

2

[M+29]

+

(electrophilic addition)

From [M+1]

+

ion, two reactions of decomposition are visible: a) H transfer and the olefinic molecules (C

4

H

8

, C

5

H

10

, C

8

H

16

) elimination and, b) H transfer and alkane molecule

(CH

4

) elimination. From [M+29]

+

only the olefinic molecules (C

4

H

8

, and respectively C

8

H

16

) are eliminated after H transfer.

The CI mass spectra configuration is discussed in correlation with the R

1

and R

2 structure and, also, in comparison with EI mass spectra. The obtained results are used for the structure elucidation of some aromatic amines.

62

THE STRUCTURE OF THE FIRST SOLVATATION SPHERE IN

TERNARY SOLUTIONS OF SOME CYCLOIMMONIUM YLIDS

Dana Dorohoi

“Al.I.Cuza” University, Faculty of Physics, Iaşi, Bd. Copou, nr.11, 6600 Iaşi,

Romania, E-mail ddorohoi@uaic.ro

The zwitterionic compounds, such as cycloimmonium ylids (CY) , were considered to approximate the structure of the first solvatation sphere in the ternary solutions.

In nonpolar solvents CY participate in induction-dispersion interactions, but in polar, protic solvents orientation induction and specific interactions of the type proton donoracceptor occur supplementary.

The spectral shifts, related to the gaseous state of CY, in the electronic spectra are strongly dependent on the solvent nature. The concentration of the protic solvent in a mixture of two solvents, one non-polar and another protic, modifies the distance between the electronic levels participating to the intramolecular charge transition (ICT), responsible for the visible absorption electronic band appearance.

The average statistical weights p

1

of the protic solvent in the first solvatation sphere of

CY were expressed by the wave numbers of the visible ICT band, in the limits of a statistical model on the ternary solutions, by the relation

p

1

1

t

2

2

, where the wave numbers in the maximum of the ICT band are measured in the protic solvent (1), the non-polar one (2) and in their mixture (t).

Five CY with different heterocycles and common carbanion were used in different pairs of solvents. We illustrate this dependence for p-phenyl-pyridazinium anilido-benzoyl methylid in the mixture octanol+1,2-dichloroethane and in benzene +1,2propane diol.

Nr. Octanol +1,2dichloroethane Benzene +1,2 propanediol

X

1

1

(cm

-1

)

P

1

X

1

1

(cm

-1

)

P

1

1

2

3

4

0

0.025

0.052

0.141

19950

20140

20360

20620

-

0.124

0.268

0.438

0

0.064

0.126

0.303

20360

20590

20810

21620

-

0.111

0.217

0.609

5

6

0.330

0.597

21020

21350

0.699

0.915

0.566

0.796

22100

22240

0.841

0.908

7 1 21480 0 1 22430 -

From this table, it results that the molar weight X

1

in ternary solution differs by the average statistical weight in the first solvatation sphere.

63

HPLC SEPARATION OF SOME PHENOLIC COMPOUNDS

FROM WASTE WATERS

Constantin Măruţoiu, Virginia Coman, Miuţa Filip

“RALUCA RIPAN” INSTITUTE OF CHEMISTRY,

30 Fântânele Street, RO-3400 Cluj-Napoca, P.O. Box 702

Phenolic compounds are toxic substances almost ubiquitous in the environmental.

They are often present in the waste effluents of coking plants and brown coal distilling plants and are intermediates in the production of plastics, drugs and dyes. Chlorophenols and, in part, nitrophenols are used in the synthesis of weed-control agents and other pesticides.

Consequently, the phenols pollute the surface and underground waters and the necessity of methods for phenol compound analysis from water is a permanent problem.

In this work, a HPLC method for the separation, identification and determination of some phenolic compounds (phenol, resorcinol, pirocathecol,

-naphthol,

p

-nitrophenol,

o

-nitrophenol,

p

-chlorophenol,

m

-aminophenol) have been elaborated. This mixture has been separated with an High Performance Liquid Chromatograph (JASCO Firm): Intelligent

UV/VIS 975 Detector (JASCO PU-980), Column NUCLEOSIL 120 (C18, 5

 m, 25x0.4 cm) using the methanol

 water (40:60, v/v) mixture as mobile phase.

Sample standard solutions were used for experiment and the present method was applied for waste water samples contaminated with the studied phenolic compounds. The obtained results for a contaminated sample of waste water are given in the following chromatogram. mV

10

8

p

-NO

2

-phenol

6

4

2

Resorcinol Pirocatechol

Unknown Phenol

m

-NH

2

-phenol

o

-NO

2

-phenol

p

-Cl-phenol

-Naphthol

5.00

10.00

15.00

20.00

[min]

64

THE STASIW-TELTOW MODEL FOR THE I-2V CLUSTERS IN

ALKALI-HALIDE CRYSTALS

G.D.Stoicescu,

Lucian Blaga University of Sibiu, Romania

Compared to the large amount of data concerning the properties of doubly charged cationic impurities in alkali halides, very little is known about the behaviour of triply cationic impurities in such crystal lattices.

Up to now only very few dates about the properties of aggregation of Impurity-two vacancy centres exist.

For the reasons of electrical neutrality of crystal lattice, each substitutionally incorporated trivalent ion is expected to be accompanied by two charge compensating vacancies. As in the case of divalent ions, the resulting dipole complexes will have the tendency to migrate and agglomerate.

The preparing of alkali halide single crystals containing Bi

3+

ions is far from trivial, due to the formation of (BiO)

+

ions by the hydrolysis of BiCl

3

to BiOCl, as well as due to the high stability of such ions in reducing conditions.

The degree of association of dipole complexes I-2V increases with increasing temperature. By keeping a quenched crystal at fixed temperature, the migration of defects resulting in formation of higher complexes (

i.e.

aggregation) occurs.

The paper represents a study of the four types of different complexes I-2V with the vacancies placed in the first co-ordination sphere (nn positions). These might be produced due to the different factors, the main being the electrostatic interaction. From the Boltzmann statistics of distribution of vacancies, it follows that only two types of complexes are significant.

The paper represents an extension of Stasiw-Teltow model for these structures.

The study of dielectric absorption does confirm this adapted model.

65

SPECTROSCOPIC ANALYSES OF OXIDATION PROCESS

IMPROVEMENT IN PULSED LASER DEPOSITION OF THIN

FILMS

Ileana Apostol, R. Stoian, C. Luculescu, R. Dabu, A. Stratan

National Institute for Laser, Plasma and Radiation Physics, Laser Dept., P. O.

Box MG 36, R-76900, Bucharest, Romania

Pulsed laser ablation of solid multicomponent targets induces a simultaneous vaporisation of target components, resulting a congruent material removal from target surface and deposition on the substrate. The presence of a reactive atmosphere during laser ablation of high-T c superconductors and generally of oxidic materials has been proved to be essential to grow high-quality films. In most cases in-situ deposited YBCO films presented an oxygen deficiency, the oxygen concentration being dictated by the kinetics of oxidation reaction and the criterion of thermodynamic phase stability at the growth temperature. It is well known that the oxygen content in the thin film controls the superconducting properties of YBCO thin films. Many authors have been tried to control the oxygen content in the film by either gas phase oxidation or incorporation of oxygen at the surface of the heated film. The influence of the reactive ambient atmosphere during the ablated material transport from the target surface to the collecting substrate to grow high-quality films with superconducting properties and film homogeneity has been studied. The efforts have been concentrated in finding the optimum oxygen or other oxidising gases with lower dissociation energy partial pressure, high enough to produce an efficient oxidation and low enough to avoid particle expelling from the plasma plume.

In our case we have used a transversal IR laser simultaneously with the UV laser beam producing the plasma, focused in front of the plume, for oxygen dissociation and atomic oxygen formation, as a method for oxidation improvement by gas-phase interaction during the material transport from the target to the substrate.

Oxides enhancement in the expanding plume has been analysed by optical spectroscopy.

We observed an enhanced emission in the assisted dissociation ablation spectra for the oxide lines in the region 590-615 nm. The enhanced oxide emission, especially at later times, where the atomic and ionic emission is low, can be considered to be due to the oxidation in the gasphase interaction with the dissociated oxygen. This particular behaviour of the oxide lines in the breakdown assisted PLD and the delayed enhanced emission can be correlated with the slow motion of the oxide molecules, due to the inelastic interaction which may lead to a loss in the kinetic energy of the precursors for oxide formation in the excited states, followed by optical emission at later times.

66

STRUCTURAL, OPTICAL AND TRANSPORT PROPERTIES

OF II-VI NARROW-GAP SEMICONDUCTING THIN FILMS

E. Indrea, Adriana Barbu, Xenia Filip and I. Bratu

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O. Box 700, 3400 Cluj 5, Romania

Phone: 064 185027 ext.214, Fax: 064 420042, E-mail: eindrea@L30.itim-cj.ro

Mercury cadmium telluride (Hg

1-x

Cd x

Te or MCT) is a direct band-gap semiconductor alloy, which can be tuned by varying the alloy fraction

x

in order to detect infrared wavelengths over a wide spectral range (0.8

 m

25

 m). CdTe thin films have interesting properties for use in photovoltaic solar cells because of their optimum energy gap (

E g

=1.44eV) and their availability as

p-

and

n-

materials.

CdTe and MCT narrow-gap semiconductor materials were deposited as thin films on optical glass, by the thermal evaporation process and by laser-assisted physical vapour deposition

(LAPVD) process. A pulsed CO

2

-TEA laser with 5J/pulse energy was used to vaporise the studied materials in an original vacuum vapour deposition system.

The Fourier analysis of the (111) CdTe X-ray diffraction profile was used to determine the average effective crystallite size, the root mean square of the microstrain, the stacking fault probability within the crystallites and the dislocation density for CdTe thin films of various thickness.

EXAFS spectroscopy has allowed us to obtain information about the local atomic structure in

Hg

1-x

Cd x

Te (

x

=0.21) narrow-gap semiconductor alloy.

We have found that the Hg-first coordination shell consists in four tetrahedral coordinated Te atoms at 0.280 nm. The second shell is split into two contributions having the bond lengths of

0.452 nm for Hg-Cd and 0.459 nm for Hg-Hg pairs, respectively.

Measurements using the so called “open cell” photoacoustic technique were done to establish the optical absorption edge of the CdTe (

E

og

=1.45eV) and of the Hg

1-x

Cd x

Te (

E

og

=0.3eV)

(having

x

=0.3 alloy fractional composition).

Electrical conductivity and Hall effect measurements in the Van der Pauw configuration, have been done to establish the

n-

type character of current carriers, the nature and the energy of localised states and the dominating scattering mechanism of free carriers in a large range of temperature.

67

BIOLOGICAL CELL SUSPENSIONS INVESTIGATED BY

LIGHT SCATTERING TECHNIQUE

I. Turcu, E. Vinteler, Silvia Neamtu, Lorelai I. Ciortea

National Institute for Research and Development of

Isotopic and Molecular Technologies, Cluj-Napoca, Romania

Light scattering technique is a powerful tool that gives detailed information on the complex dynamic processes fulfilled by suspended biological cells.

Using light scattering is one of the easiest ways of characterising the concentration of diluted cellular suspensions. For suspended human erythrocytes, for example, there is a maximum of scattered light intensity at a hematocrit of about 10

-3

for 2-mm thick suspension.

At higher concentration the scattering decrease, the maximum being the consequence of the balance between the increasing number of scattering centres on one side and the absorption of light by intracellular haemoglobin on the other side.

The erythrocyte shape is also an important parameter that can be detected by scattering experiments. The scattering cross section of erythrocytes with different shapes is a parameter that induce some small changes in the scattering efficiency but the effect is much more marked in the dynamic of sedimentation. The signal fluctuations are very sensitive to cellular shape. The amplitude of fluctuations is a few times higher for discocytes in comparison with spherocytes.

The cells change their shape with the tonicity of solution due to the osmotic unbalanced equilibrium. The signal obtained from light scattered on the erythrocytes suspended in hypotonic (0.54% Na Cl), isotonic (0.9% Na Cl) and hypertonic medium (1.5 %

NaCl) has been analysed. The dynamic of the erythrocytes shape changes in the hypotonic hemolysis process was also investigated.

In parallel, we have studied the hemolysis process induced by short electric field pulses applied on the isotonic erythrocyte suspensions using the electroporation technique. In both osmotic and electric processes, the cells change the shape from the discocyte to sferocyte due to the osmotic unbalanced equilibrium followed by lysis of the cells. In the first case, the process is due to the lower tonicity of the medium while in the second case is due to the increase of the membrane permeability to ions and other extracellular molecules.

Hypotonic hemolysis of cells was induced in 4-mM phosphate buffered solution with

30-mM glycerol. The electrohemolysis was induced by exposing the erythrocyte suspension to electric pulses with 4 kV/cm amplitude and 50

 s length. The processes were recorded ten minutes.

The kinetic of erythrocytes aggregation was captured by an experimental set up able to detect the light scattered at small angles. The fluctuations in the intensity of scattered light increase because of erythrocytes aggregation process. The scattering data contain information concerning the details of the complex aggregationsedimentation process.

Light scattering experiments were performed with a 10 mW He-Ne laser at 628 nm wave length.

68

EXTENDED X-RAY ABSORPTION FINE STRUCTURE AND X-

RAY DIFFRACTION STUDIES ON SUPPORTED Ni

CATALYSTS

1

N. Aldea,

1

P. Marginean,

2

Xie Yaning,

2

Hu Tiandou,

2

Liu Tao,

2

Zhongua Wu and

2

Dai Zhen Ya

1

National Institute for Research and Development of Isotopic and Molecular

Technologies, 3400 Cluj-Napoca, Romania

2

Beijing Synchrotron Radiation Facilities of Beijing Electron Positron Collider

National Laboratory, People’s Republic of China

In the first part of paper, we present a study based on EXAFS spectroscopy. This method can yield structural information about the local environment around a specific atomic constituent in the amorphous materials, the location and chemical state of any catalytic atom on any support or point defect structures, in alloys and composite. EXAFS is a specific technique of the scattering of X-ray on materials. The present study is aimed toward elucidation the local structure of Ni atoms and their interaction with oxide support. The second deal of paper consists in X-ray diffraction on the same samples. X-ray diffraction method that is capable to determine average particle size, microstrains, probability of faults as well as particle size distribution function of supported Ni catalysts is presented. The method is based on the

Fourier analysis of a single X-Ray diffraction profile. The results obtained on supported nickel catalysts, which are used in H/D isotopic exchange reactions are reported. The global structure is obtained with a new fitting method based on the Generalised Fermi Function facilities for approximation and Fourier transform of the experimental X-Ray line profiles.

Both types of measurements were performed on Beijing Synchrotron Radiation Facilities

(BSRF).

69

NUCLEAR MAGNETIC RESONANCE STUDY OF NAPROXEN

AND IBUPROFEN INTERACTION WITH

- CYCLODEXTRIN IN SOLUTION

M. Bogdan, S.I. Farcas, * M. Bojita

National Institute for Research & Development of Isotopic and Molecular

Technologies, PO Box 700, Cluj - Napoca

*Faculty of Pharmacy, University of Medicine and Pharmacy, Cluj - Napoca

Modern biomedical research leads to revealing insights into the molecular activity of many therapeutic molecules. An interesting activity at the organ or cellular level, however, is not sufficient to turn a molecule into an usable drug. Problems such as limited solubility or stability can make impossible to transpose interesting in vitro properties of an experimental compound to an in vivo situation. Various physico - chemical methods have been used to improve aqueous solubility of poorly soluble drugs and to increase the life of unstable drugs, such as adjustment of pH of the aqueous solution, the complexation of drugs with various cyclodextrins and the formation of gels or emulsions.

In this paper, we report a

1

H NMR study of the complex formed between naproxen and ibuprofen with

- cyclodextrin in aqueous medium. Our results confirm that inclusion occurs. Analysis of our data by the continuous variation method shows that the complexes have 1 : 1 stoichiometry. The association constants for the 1 : 1 complexes were calculated at different temperatures by non - linear least squares regression analysis of the observed changes in the chemical shifts of the drugs and

- cyclodextrin

1

H NMR lines as a function of

-cyclodextrin concentration. Thermodynamic parameters were obtained by using the temperature dependence of the association constants. Finally, based on the experimentally obtained data, the most probable structure of the investigated complexes is discussed.

70

S e c t t t i i i o n

B

M o l l l e c u l l l a r r r p r r r o c e s s s s s s e s s s

P o s s s t t t e r r r s s s

71

72

RIETVELD ANALYSIS AND ELECTRONIC BANDS

STRUCTURE ON T

c

SUPERCONDUCTORS SYSTEMS

1

N. Aldea,

1

C. V. Tiusan and

2

V. Sandu

1

National Institute for Research and Development of Isotopic and Molecular

Technologies, 3400 Cluj-Napoca, Romania

2

National Institute for Physics and Materials Engineering, MG. 6, Bucharest

Magurele

A procedure for simultaneous refinement of structural and micro-structural disorder parameters for polycrystalline YBa

2

Cu

3

O

7-x

system is proposed. It is based on Rietveld method combined with Fourier analysis for broadened peaks Another purpose of this paper consists in electronic structure determination studied by using the self-consistent Tight

Binding Linear Muffin-Tin Orbital Atomic Spheres Approximation TB-LMTO-ASA methods. The Rietveld method uses an analytical function that describes the profiles, usually pseudo-Voigt (pV) or Pearson VII (PVII) .The parameters of the analytical profiles describe its amplitude, position and peak shape. The full width at half maximum (FWHM) is supposed to vary with the diffraction angle in agreement with the Caglioti, Paoletti and Ricci's relationship. The best structural parameters are determined in the least squares sense by the minimisation a classical residual using the Marquardt. In this case, the peak profiles were modelled by the pseudo-Voigt function corrected by the instrumental asymmetry. The physical information obtained are: scale factor, lattice parameters, atomic position and displacements, atomic occupation numbers, temperature factor (isotropy or anisotropy), preferred orientation parameter, crystalline size and micro-strain along different crystallographic directions, distributions of crystallite size and micro-strain functions. This procedure was implemented on computer code and it has a friendly graphical interface based on pull down menus technique. From the experimental point of view the X-ray diffraction data were collected using a horizontal powder diffractometer in the Bragg-Brentano (BB) geometry with a Ni filtered CuK

,

=1.54178 Å., at room temperature using a DRON 2 setup. The diffraction profiles were measured with a proportional gas detector, a single channel pulse-height discrimination and a standard associated counting circuit. The electronic bands calculations are based on the TB-LMTO program version 47 under 2.03 LINUX operating system version. The main steps of our calculations are: the generation of the overlapping potentials from the atomic Hartree potentials and the finding of the MT-radii, the calculation and drawing of the sphere overlaps, the finding of the interstitial spheres, the generation of the structure constants and perform self-consistent calculations. The LMTO method can be regarded as an LCAO (linear combination atomic orbitals) formalism in which the muffin-tin potential (MT), rather than the atomic potential, defines the set of basis functions used to construct the trial functions of the variational procedure.

73

EXTENDED X-RAY ABSORPTION FINE STRUCTURE

AND X-RAY DIFFRACTION STUDIES ON La

2

AlB

4

O

12

SYSTEM

1

N. Aldea,

2

S. Simion,

2

V. Martian,

2

Mihaela Gorgoi,

2

Geanina Gavrila,

3

Xie

Yaning,

3

Hu Tiandou,

3

Liu Tao,

3

Zhongua Wu and

3

Dai Zhen Ya

1

National Institute for Research and Development of Isotopic and Molecular

Technologies, 3400 Cluj-Napoca, Romania

2

Babes-Bolyai University, Physics Department

3

Beijing Synchrotron Radiation Facilities of Beijing Electron Positron Collider

National Laboratory, People’s Republic of China

In the first part of paper, we present a study based on EXAFS spectroscopy. This method can yield structural information about the local environment around a specific atomic constituent in the amorphous materials, the location and chemical state of any catalytic atom on any support or point defect structures, in alloys and composite. EXAFS is a specific technique of the scattering of X-ray on materials. The present study is aimed toward elucidation the local structure of La atoms. The second deal of paper consists in X-ray diffraction on the same samples. Method of Radial Distribution Function (RDF) for local structure determination is used. The method is based on the Fourier analysis of the whole spectrum. Here we present a comparative study a local structure determination obtained by two complementary methods.

The results obtained on La

3

AlB

4

O

12

system are reported. Both types of measurements were performed on Beijing Synchrotron Radiation Facilities (BSRF).

74

EPR AND IR STUDY OF B

2

O

3

-V

2

O

5

-PbO GLASSES

1

I. Ardelean,

2

Sanda Filip,

3

I. Bratu,

1

Viorica Simon,

1

O. Cozar,

2

C. Cefan

1

“Babes-Bolyai” University, Faculty of Physics, Kogalniceanu 1,

Cluj-Napoca, Romania

2

University of Oradea, Dept. of Physics, Oradea, Romania

3

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O. Box 700, Cluj-Napoca 5, Romania

Using electron paramagnetic resonance (EPR) and IR spectroscopy we have studied the local structure of

x

B

2

O

3

(1-

x

)[V

2

O

5

PbO] glasses with 0

x

0.9. In these glasses, we have evidenced the presence of V

4+

ions and modification of the local structure in function of

x

.

STRUCTURAL PROPERTIES OF THE V

2

O

5

-PbO

VITREOUS SYSTEM

1

I.Ardelean,

2

Sanda Filip,

3

I. Bratu,

1

O. Cozar,

1

Viorica Simon,

2

T. Jurcut

1

and

2

C. Cefan

“Babes-Bolyai” University, Faculty of Physics, Kogalniceanu 1,

Cluj-Napoca, Romania

2

University of Oradea, Dept. Of Physics, Oradea, Romania

3

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O. Box 700, Cluj-Napoca 5, Romania

Structural models of the glasses of the

x

V

2

O

5

(1-

x

)PbO system with 0.4

x

0.9 are analysed. These data are obtained using electron paramagnetic resonance, IR and Raman spectroscopy.

75

STRUCTURAL PROPERTIES OF THE V

2

O

5

-B

2

O

3

VITREOUS SYSTEM

1

I.Ardelean,

2

Sanda Filip,

3

I. Bratu,

1

O. Cozar,

1

Viorica Simon,

1

M.Peteanu and

2

C. Cefan

1

“Babes-Bolyai” University, Faculty of Physics, Kogalniceanu 1,

Cluj-Napoca, Romania

2

University of Oradea, Dept. Of Physics, Oradea, Romania

3

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O. Box 700, Cluj-Napoca 5, Romania

The influence of vanadium oxide on the structure of

x

V

2

O

5

(1-

x

)B

2

O

3

glasses with

0.05

x

0.7 was investigated by IR and Raman spectroscopy. The presence of V

2

O

5

in B

2

O

3 glass matrix determines the appearance of fourfold coordinated boron atoms in diborate groups and isolated BO

4

units. The characteristic Raman bands of vanadium groups do not appear even at the very high V

2

O

5

content.

CHARACTERIZATION OF POLYANILINE BY

IMPEDANCE SPECTROSCOPY

S.Pruneanu

1

, G.Mihailescu

1

, G.Inzelt

2

1I.N.C.D.T.I.M., P. O. Box 700, Cluj-Napoca 3400, ROMANIA

2Department of Physical Chemistry, Eotvos Lorand University, P. O. Box

32, H-1518 Budapest 112, HUNGARY

The a.c. response of polyaniline (Pani) films on platinum electrodes, in 5sulfosalicylic or perchloric acid (1M), was measured at different d.c. potentials in the range from –0.2V to 0.4 V/SCE. The films were prepared by cyclic voltammetry, from aqueous solution of aniline (0.2 M) and acid (1 M). The scan rate was 100 mVs

-

1

, in the potential range from –0.2V to 0.85 V/SCE. In order to avoid the film degradation, the positive potential limit was gradually decreased. The preparation of

Pani films and the impedance spectroscopy measurements were performed at room temperature. We have used a frequency response analyser, Solartron 1250 connected to a 1286 Solartron electrochemical interface.

The electrical circuit model, proposed to interpret the experimental impedance data, is a modified Randles circuit. It additionally contains two capacitances, C p1

and

C p2

, which were assigned to the geometric construction of the cell and to the double layer at metal/polymer interface, respectively.

Based on this electrical model, we have determined the values of the parameters characteristic for the redox process, such as: charge transfer resistance (R ct

), double layer capacitance at polymer/solution interface (C d

), Warburg coefficient, double layer capacitance at metal/polymer interface (C p2

) and low frequency capacitance

(C

L

). All these parameters strongly depend on the applied d.c. potentials, i.e. on the oxidation state of polyaniline films.

76

THE CONCENTRATION OF SOME VOLATILE

HYDROCARBONS IN ATMOSPHERE

P. Ardeleanu, C. Cuna F.Dunca, S. Cuna, Z. Moldovan,

*

C. Ardeleanu,

D. Ioanoviciu and P. Vegh

National Institute for Research and Development of Isotopic and Molecular

Technologies, 3400 Cluj-Napoca 5, P. O. Box 700, Romania

* Technical University, Department of Automation and Computers, 3400 Cluj-

Napoca, Romania.

The measurement of the atmospheric abundances of CH

4

and volatile hydrocarbons has received considerable interest after their environmental significance was recognised. The methane is one of the most important radiatively active trace gases in the atmosphere (belong to so-called green house gases) and thus will contribute to climatic changes on Earth within the next century. It has also an important influence on the abundance and distribution of OH radicals in troposphere, which has at its turn an important impact on the chemical composition of the Earth’s atmosphere. It must also mentioned, that CH

4

has an important influence on the ozone concentration in troposphere.

There is evidence that the concentration of methane in the atmosphere is rising rapidly, and that present levels are approximately double those of a few hundred years ago.

Taking into account the role of the methane and volatile hydrocarbons in the chemistry of the atmosphere and in the Earth radiations budget as well as their influence on the public health, reliable analytical measurements of their concentrations are of outstanding importance for remedial actions.

The measurements were carried out using a double focusing Finnigan MAT 311( operated in GC - MS mode), on an ATLAS M86 mass spectrometer and on a differentially pumped mass spectrometer constructed in our institute.

The collected samples were prepared by using the differentially cooling method (the fractionated distillation method) for hydrocarbons enrichment.

To improve the precision they were compared with a standard prepared in our laboratory.

The values obtained from the measurements are a little bit higher than expected, the mean values of the mixing ratios for methane laying around 1700 ppb. The explanation could consist, partly in the existence of local sources of these pollutants and also in the atmospheric OH activity, as a sink of methane.

The work is a part of a long time watching of volatile hydrocarbons mixing ratios in our geographical area.

77

AMORPHOUS TiCu RIBBONS STUDIED BY

PHOTOACOUSTIC TECHNIQUE

Biljana Radojevic

1

, Adriana Barbu

2

, E. Indrea

2

, N. Băltăteanu

3

1

Center for multidisciplinary studies of Belgrade University, 1a Kneza

Viseslava St, 11000 Belgrade, Yugoslavia

2

The National Institute for Research & Development of Isotopic and Molecular

Technologies, P. O. Box 700, 3400 Cluj-Napoca 5, Romania

3

Hyperion University, 14 Culmea Veche St., Bucharest, Romania

Structural properties of new materials - as polymers, semiconductors, glasses, amorphous metallic ribbons - can be successfully investigated by photoacoustic (PA) techniques together with X ray measurements.

The heat generated in a sample, because of the absorption of a part of the incident radiation due to the nonradiative processes, is measured using a home-made photoacoustic experimental setup.

Rapidly quenched TiCu ribbons were prepared by melt-spinning technique in helium atmosphere. 40

 m thick TiCu ribbons were irradiated by 6 MeV electron beam for different duration, up to 15 minutes.

Thermal properties, particularly the thermal diffusivity coefficient, and their changes, because of the interaction of the electron beam with the sample were revealed by the photoacoustic measurements. A deep decrease of the value of this coefficient after the irradiation has been evidenced.

The structural changes of TiCu ribbons appeared after the irradiation were evidenced by X ray diffraction measurements, as a slow crystallisation process own to the samples’ irradiation.

78

Zr-BASED ALLOYS AS HYDRIDE ELECTRODES IN Ni-

MH BATTERIES

A. R. Biriş, A. S. Biriş, I. Mişan and D. Lupu

National Institute for Research and Development for Isotopic and Molecular

Technologies

R-3400 Cluj-Napoca, P. O. Box 700, Romania

Hydrogen storage alloys, MH, are already used in Ni-MH alkaline batteries conquering an important share of the rechargeable nickel-cadmium battery market. This remarkable success is due not only to the replacement of the toxic material, cadmium, by metal hydrides but also to an increased specific energy, which makes them attractive for electric vehicles. Many research groups are concerned in the improvement of the hydride electrodes characteristics: hydrogen storage capacity, high-rate discharge ability, increased cycle life. These properties can be modified by substitution of the base components of a given alloy. A comparison of the two types of alloys suitable for MH electrodes LaNi

5

able to store

1.36 w/o hydrogen with Zr(Ti)-Ni alloys of the AB

2

-Laves phase type structure showed that the later could absorb higher amounts of hydrogen.

We report in Fig. 1 part of our studies on Zr-V-Cr-Ni of the C15 type Laves phase structure using our original procedure for pasted electrodes.

250

200

150

100

50

ZrV

0,5

Ni

1,5

ZrV

0,35

Cr

0,15

Ni

1,5

ZrV

0,25

Cr

0,25

Ni

1,5

ZrV

0,525

Cr

0,225

Ni

1,5

+ 3% Mm

ZrV

0,525

Cr

0,225

Ni

1,5

+ 3% Mg

0

0 50 100 150

Cycles

200 250 300

Fig 1. Behaviour of the alloys at charge-discharge cycling as hydride electrodes (charge: 2 h at 200 mA/g, open circuit 10 min, discharge at 160 mA/g ) in 6M KOH at 20 o

C.

The substitution of Cr for V atoms in ZrV

0.5

Ni

1.5

did not increase the discharge capacity. However, it proved to have a remarkable effect on the discharge capacity C at low temperatures. C at –12 o

C compared to 20 o

C increases to ~ 65 % for Cr containing alloys.

79

OPTICAL AND THERMAL PROPERTIES OF

x

V

2

O

5

(1-

x

)[P

2

O

5

.CaO] GLASSES

I. Bratu*, Adriana Barbu* and Nicoleta Vedeanu**

*Institute for Isotopic and Molecular Technology, P.O. Box 700, 3400

Cluj 5, Romania

Phone: 064 405300, Fax: 064 191906, E-mail: ibratu@l30.itim-cj.ro

**”Babes-Bolyai” University, Faculty of Physics, Kogalniceanu 1, 3400

Cluj.

Optical and IR spectroscopy can be successfully used to investigate the structure of vitreous oxide glasses. The thermal diffusivity coefficient is the most used one in the material characterisation. A vitreous oxide system

x

V

2

O

5

(1-

x

)[P

2

O

5

.CaO] with 0 <

x

< 40 has been obtained. The amorphous nature of these glasses was controlled by X-ray diffraction.

Thermal diffusivity coefficient values of these phosphate glasses containing vanadium ions were determined with the “

open-cell

” photoacoustic technique. The experimental parameters were selected as to apply the so-called “thermoelastic” model (“

thermally thick

” and

optically opaque”

samples) to the measured photoacoustic signal. Thermal diffusivity coefficients were calculated for all samples. The behaviour of the thermal diffusivity coefficients with the vanadium content was correlated with the structural changes that appear in these glasses. The rapid increase of the thermal diffusivity with the V

2

O

5

content up to 3-5

% shows an important structural rearrangement of P-O-P and P=O bonds at the initial addition of this oxide . Then, by further addition of vanadium oxide no significant changes were observed in the magnitude of the thermal diffusivity coefficient.

80

SPECTROSCOPIC AND MAGNETIC INVESTIGATION

OF SOME METAL COMPLEXES WITH OROTIC ACID AS

LIGAND

I.Bratu

1

, L. David

2

, Crăiţa Bălan

2

, Cora Crăciun

2

, O. Cozar

2

, Gh. Bora

3

1

National Institute for Research and development of Isotopic and Molecular Technologies,

3400 Cluj Napoca, Romania

2

"Babes-Bolyai" Univ., Dept. of Physics, 3400 Cluj Napoca, Romania

3

Chemical-Pharmaceutical Research Institute, 3400 Cluj Napoca, Romania

Orotic acid (OA: 6-uracilcarboxylic acid, OrH

2

, vitamin B

13

), its salts and other derivatives play an important role in the metabolism of pyrimidine nucleotides and are found in cells and body fluids of many living organisms. The metal complexes M(OA) n

(M =

Cu(II), Mn(II), n=2; M=Cr(III), Fe(III), n=3) were investigated by spectroscopic and magnetic measurements.

IR spectroscopy reveals that for the metallic ions, the orotate ligand acts as a chelating coordinated by the carbonyl oxygen and the nitrogen imino atom (Table 1). The exocyclic oxygen atoms of the pyrimidine ring are not involved in metal ion binding [2]. The local symmetries around the bivalent and trivalent metal ions are pseudotetrahedral and octahedral, respectively.

Table 1.

Selected IR bands (cm

-1

)

Cu(OA) Mn(OA) Cr(OA)

OA

Fe(OA)

2 2 3 3

(O-H)

1268

 ring

(C=O) 1666

(N-H)

(O-H)

3200

3540

1285

1676

3175

3525

1283

1672

3180

3520

1282

1684

3180

3523

1283

1683

3175

3522

The powder ESR spectra of Cu(OA)

2

at room temperature

(Fig.1) are typical for pseudotetrahedral monomeric species. The g



= 2.238 and g

= 2.071 values correspond to a CuN

2

O

2

cromophore.

The powder ESR spectrum of Mn(OA)

2

is quasi isotropic, with principal values of the g tensor close to the spin-only value (g =

Fig. 1

Powder

2.0018). The ESR spectrum of FeL

3

∙5H

2

O is almost isotropic (g =

2.002). The presence of a weak signal at g

4 suggests a small

ESR spectrum of

Cu(OA)

2

distortion of the octahedral symmetry around the metal ion.

The magnetic susceptibility measurements indicate a Curie–Weiss behaviour, with magnetic moments specific for monomeric species. The value obtained for the magnetic moments of Cu(II) complexes (μ eff

= 1.71

B

) is in the normally observed range for pseudotetrahedral species, while those corresponding to high–spin Mn(II) and Fe(III) (6.71

B

and 5.05

B

, respectively) rather yield local octahedral environments. The paramagnetic

Curie temperatures (

= 5 K, and 35 K for Cu(II) and Fe(III) complexes, respectively) indicate the presence of some exchange interactions between the metallic ions, due to the formation of intermolecular hydrogen bonds.

81

QUANTITATIVE AND QUALITATIVE ANALYSIS OF

ACTIVE PRINCIPLES OF MENTHE PIPERITA L. AND

HIPPOPHAE RHAMNOIDES L. BY GC/MS

C.Gherman, M.Culea

*

, O.Cozar

Universitatea “Babes-Bolyai”, Cluj-Napoca

*

S.C.”Natex”S.R.L., Cluj-Napoca

The active principles in plants are the chemical organic substances synthesised in the vegetal cells. Theirs chemical structure is very different; this is the reason for their multiple therapeutics actions.

The compounds identified in different types of the same plants of Menthe piperita L. extracted by liquid-liquid extraction (LLE) method are presented in the first part of the article. In the second part of the article are presented quantitative determination of vitamin E from Hippophae rhamnoides L. oil. The extraction was followed by gas chromatography and gas chromatography-mass spectrometry analysis.

The extraction was compared at the same variables in the optimisation process: amount of sample, extracting solvent volume, extraction temperature, and extraction time. Precision of the extraction method gave relative standard deviation lower than 3%.

The extracts where analysed by GC-FID and GC-MS. A HP-1 capillary column,

30mx0.32mm, 0.25

 m film thickness, in a temperature program from 50

C, kept 2 minutes, then increased to 250

C, with a rate of 8

C per minute was used.

The gas chromatography-mass spectrometry analysis results prove the existence a some active principles of Menthe piperita L: isobutyric acid, isomenthone, menthone, guanidine, carvone, palmitic acid, ethyl palmitate, and a.o. We have analysed Menthe piperita L oil also, and the active principles discovered here are: menthol, menthone, isomenthone, menthol acetate,

-pinen,

-pinen, champhor, lymonen, lynalol, pyperitone, a.o.

In conclusion, we can observe that the plants provided from private garden, keep the volatile substances much better. The results show very different compounds for the different types of the same plant, as a consequence probably of clime, sole, and other factors.

The second part of this article show the quantitative analysis of vitamin E from Hippophae rhamnoides L. oil determined by GC/MS method. We are used a calibration curve, with the cholesterol as intern standard. The regression curve is y=0.14x-0.20 and the correlation factor, shows a good linearity(r= 0.99). We have analysed as well the saturate and unsaturated fatty acids as FAME (fatty acid methyl of esters).

Vitamin E was determined from the regression curve in Hippophae rhamnoides L. oil for the different measured values for, m/z.

The results show that Hippophae rhamnoides L. oil contains 0,05 % vitamin E which has an antioxidant roll and takes an important function in nutrition, cardiovascular diseases, and muscular, nervous and glandular system ageing process.

We can also observe different values for FAME that in pulps, seeds and integrals fruits. The results show that the most important fatty acids are lynoleic acid (C

18

:1), lynolenic acid

(C

18

:2), stearic acid (C

18

:0), oleic acid, and a.o.

The GC and GC/MS methods used were appropriated for the aini of this work.

82

ESR AND

AB INITIO

INVESTIGATION ON

ELECTROCHEMICAL REDUCTION OF NITROFURYL

MOIETIES IN DYHYDRAZID-HYDRAZONE COMPOUND

Aniela Gagea, V.Chiş, O.Cozar, L.David, D.Ristoiu, V.Miclăuş

1

, G.Damian

“Babeş-Bolyai” University, Faculty of Physics, RO-3400 Cluj, Romania

1

“Babeş-Bolyai” University, Faculty of Chemistry, RO-3400 Cluj, Romania

Nitrofurans are compounds containing the 5-nitrofuryl radical and they show a high and wide range antibacterial activity. These compounds are quickly decomposed and eliminated from the organism, and in addition, the sensitive microorganisms do not become immune to them. Due to these interesting biological properties a series of compounds containing the furanic cycle have been synthesised. Among these, the dihydrazid-hydrazone

(DHH) was obtained by condensing 5-nitro-2-furaldehyde with the appropriate hydrazide.

This compound contains the o-sulfonamide and nitrofuryl groups, which are expected to show interesting biological properties.

This work deals with one of the paramagnetic products obtained during electrochemical reduction of nitrofuryl group from DHH compound. The electrochemical reduction measurement made at a constant intensity leaded to an observable ESR spectrum obtained with a total width of about 26 G contains a rather large number of hyperfine lines and decays in several minutes.

This main structure of the ESR spectrum was simulated assuming the interaction of the unpaired electron with one nitrogen nucleus and two protons. Based on the structure of

DHH compound and ESR parameters deduced by simulation we propose the free radical given in Fig.1 to be responsible for the main hyperfine structure in the experimental spectrum. The experimental coupling constants and unpaired spin density determined by us are comparable with those corresponding to others radicals in which the odd electron is delocalized on a similar fragment.

Fig.1 Proposed structure for the free radical obtained by electrochemical reduction of NO

2 group of DHH

The geometry of the radical has been investigated by

Ab Initio

calculations, performed with GAMESS package. Molecular structure of the radical has been optimised by gradient methods at

UHF level using different basis sets. The calculated unpaired spin densities are in good agreement with those experimentally obtained, being consistent with a planar structure of the radical at nitrogen site.

83

SURFACE ENHANCED RAMAN SCATTERING

EFFICIENCY OF DIFFERENT METALLIC NANOSTRUCTURES

TESTED WITH CRYSTAL VIOLET MOLECULE

S. Cintă a

, E. Vogel b

, T. Iliescu a

and W. Kiefer b a

Babes-Bolyai University, Physics Department, Kogalniceanu 1,

RO-3400 Cluj-Napoca, Romania. b

Institut für Physikalische Chemie Universitãt Würzburg, Am Hubland,

D 970974, Würzburg, Germany

The interaction manners of the molecules with the metal surface are the aim point in the surface enhanced Raman scattering (SERS). Despite the successes of the electromagnetic and charge transfer mechanisms involved in the enhancement of the Raman signal, there are also a number of effects, which cannot be explained in the framework of these theories. It should be noticed that in most cases, electromagnetic and chemical enhancement couldn’t be considered separately, strong electromagnetic enhancement could be a prerequisite for strong chemical enhancement factors. Extending the experimental procedure for preparing the SERS surfaces and acquiring more experimental data are certainly necessary for both a better understanding of the enhancement mechanisms and nature of the metal-molecule complex.

The aim of this paper is to compare the enhancement of the Raman signal provided by different nanometric substrates in order to conclude about the efficiency of each SERS active system. The irreversible loss phenomena of the SERS intensity has been recently interpreted in terms of the adatomic charge transfer effect and the localised surface plasmon effect. Since the metal substrates used in these experiments provide a good surface enhancement and stability of the Raman intensity, they are applicable in the orientation study of adsorbate molecule. Nanostructured gold and silver colloids as well as different island films were prepared and tested with the CV molecule. The ablated Ag island film prepared through the evaporation leads to a distance-dependence distribution of the Ag layer thickness and surface roughness. In addition, another Ag-Ni alloy surface was prepared through the same method.

Both metals were simultaneously ablated toward the glass plate, resulting a large range of

Ag-Ni particle size. Very small amounts of sample (final concentration of 4.7x10

-7 molL

-1

.in colloids and one droplet of 2x10

-4

molL

-1

CV methanol solution for the island films) were necessary for obtaining a huge SERS signal when the plasmons resonance is fulfilled. SERS spectra of CV on Au and Ag sols as well as on Ag island film are presented in comparison to the FT-Raman spectrum of CV solid powder. The resonance contribution to the total enhancement is discussed in all SERS systems.

Exhibiting a nonsimilar intensity pattern in all the studied cases, SERS spectra of CV on different nanostructures suggest the conditions for optimal enhancement provided by each surface.

84

IN VITRO AGEING OF ERYTROCYTES IN ZERO

MAGNETIC FIELD

D Ciorba*, V. V. Morariu**

*Clinical Laboratory of Bio-Chemistry, Moţilor Street, No 19, Cluj- Napoca,

Romania

** National Institute for Research & Development of Isotopic and Molecular

Technologies, P.O. Box 700, R 3400, Cluj-Napoca, Romania

Purpose:

The natural magnetic field or the geomagnetic field (GMF) is a physical factor of the normal environment. The natural variations of this field can affect the health of man. Consequently we may expect that the lack of GMF or zero magnetic field (ZMF) could influence the living processes as well, possibly even more than the present fluctuations of GMF. At the same time, it is possible that ZMF may have qualitatively different effects compared to the geomagnetic storms, or at least we may address this question.

The purpose of our work was to investigate the influence of ZMF on several elementary cell processes after in vitro exposure of human blood to ZMF. We have investigated the alteration of the Na

+

-K

+

ATPase and Ca

2+

ATPase function by measuring the change of the ion concentrations in the serum as well as the ratio of amino transferase-TGO and alanin amino transferase- TGP activities.

Methods:

Human blood was collected by venipuncture from apparent healthy donors. After coagulation and centrifugation, the following assays were performed in the serum, by using a Beckmann CX5 autoanalyser: sodium, potassium and calcium concentration as well as the activity of TGO and

TGP. The determinations have been performed on samples of blood exposed up to 72 hours at room temperature, at 24 hours time interval.

Results:

Sodium concentration in the serum steadily decreased in the serum while potassium increased as a result of the decreased ion pump activity at room temperature. However in ZMF conditions this process was significantly faster than for controls. At the same time calcium concentration in the serum decreased as a result of penetration into the blood cells which in turn is due to the lower activity of calcium ATPase induced by ZMF.

It has also been found that the TGO/TGP ratio increase by up to 33% after three days of exposure to ZMF conditions. This is a result of a faster decrease of TGP activity, which suggests that ZMF caused increased cellular death. This finding is in agreement with the above findings.

Conclusions:

In vitro exposure of human blood to zero magnetic field conditions leads to a significant decrease of the sodium-potassium and calcium ATPase activities as well as of transaminase activities. This implies that in vitro cell ageing and death proceed faster in ZMF compared to natural magnetic conditions. The results may be relevant to in vivo exposure of organisms to ZMF where a similar trend could hold.

85

RAMAN MICROSPECTROSCOPIC STUDY ON

THE INFLUENCE OF SALTS ON LOW pH-INDUCED DNA

STRUCTURAL CHANGES: LOW CONCENTRATIONS

OF DIVALENT IONS

C. M. Muntean *, G. J. Puppels **, J. Greve. and G. M. J. Segers-Nolten

* National Institute for Research and Development for Isotopic and Molecular

Technologies, R-3400 Cluj-Napoca,

P.O. 5, Box 700, Romania,

** Rotterdam University Hospital "Dijkzigt", General Surgery 10M,

3015 GD Rotterdam, The Netherlands

Department of Applied Physics, University of Twente, P.O. Box 217,

7500 AE Enschede, The Netherlands

Binding of H

+

to DNA, leads reversibly, to alternative DNA structures, especially to disrupted AT-basepairs and to Hoogsteen syn dG:dCH

+

basepairs, which exist under physiological conditions in purified and chromosomal DNA. Besides, irreversible changes occur in DNA, when at low pH, upon further protonation, the disruption of not only AT- but also of protonated Hoogsteen GC-basepairs takes place. In a Hoogsteen basepair, protonation of cytosine is accompanied by a conformational change of the guanine from the C2’-endoanti to C2’-endo-syn. This enables hydrogen bonding between N(7) of guanine and cytosine

N(3). Studies are required to elucidate whether the equilibrium between protonated and nonprotonated GC-basepairs can be influenced by chemical parameters.

In this work, a confocal Raman microspectrometer was used to investigate the influence of low concentrations of divalent ions on low pH-induced DNA structural changes. Based on the observation that the midpoint of transition of Watson-Crick GCbasepairs to protonated GC-basepairs lies around pH 3 (analysing the 681 cm-1 line), measurements were carried out on calf-thymus DNA at neutral pH and at pH 3. Effects of low concentrations of divalent cations upon protonation mechanism of opening AT- and changing the protonation of GC-basepairs in DNA are discussed.

Our Raman spectra show that low concentrations of divalent cations, protect DNA against protonation of cytosine (line at 1262 cm-1). Low salt concentrations do not protect adenine and guanine N(7) against binding of H+ (characteristic lines at 1304 cm-1 and at

1488 cm-1, respectively). The possible presence of Hoogsteen basepairs in DNA samples is considered.

This work was supported in part by a CEC grant under contract Nr. ERB-CIPA-CT-

92-2223.

86

CZOCHRALSKI GROWTH OF

A B

2

2

(

SO

) -TYPE

CRYSTALS

C. Neamtu

1

, Al. Darabont

2

1

National Institute for Research and Development of Isotopic and Molecular

Technologies, 65-103 Donath St., P. O. Box 700, RO-3400 Cluj-Napoca 5,

ROMANIA (E-mail: cneamtu@L30.itim-cj.ro)

2

Faculty of Physics, ”Babes-Bolyai” University, 1 M.Kogalniceanu St., 3400

Cluj-Napoca, ROMANIA (E-mail: darabont@L30.itim-cj.ro)

The

A B

2

2

(

SO

)

langbeinite-type crystals (where A

+

= NH

4

, K, Na, Rb, Cs, etc. and B

2+

=

Mn, Ca, Mg, Ni, Zn, Cd, etc.) are important due to their ferroelectric and ferroelastic properties and their strong first-order phase transition. From the above series of possible compounds, we have obtained K

2

Zn

2

(SO

4

)

3

crystals by pulling from melt using the Czochralski method.

The starting materials were initially prepared by us, but we also used reagents supplied by

“Reactivul” Bucharest, Romania. For Cu

2+

or Mn

2+

doped crystals, the Zn

2+

/Cu

2+

, Mn

2+

ratio was of about 100 in the starting materials (not verified in the grown crystals).

The pure and doped crystals were grown using a home-made Czochralski-type device. For the initial pullings, instead of a seed crystal, we used a platinum wire. From the polycrystalline boules that were formed, we tried to select single crystals by repeated decrease of the diameter of these polycrystalline boules. However, this method presented many difficulties.

Growing experiments were carried out for other langbeinitetype compounds, namely K

2

Mg

2

(SO

4

)

3

, Na

2

Zn

2

(SO

4

)

3 and

Na

2

Mg

2

(SO

4

)

3

. No differences in the quality of the obtained crystals were observed.

Not only pure crystals, but also crystals doped with paramagnetic ions such as Mn

2+

and Cu

2+

were prepared. The doping process of the K

2

Zn

2

(SO

4

)

3

and Na

2

Zn

2

(SO

4

)

3

crystals was successful, as confirmed by EPR measurements.

Our growing experiments indicate that relatively large crystals can be obtained (Fig. 1), but the single crystalline quality of the samples is not enough satisfactorily yet.

On no account, we could obtain large single crystalline samples after cooling the crystal to room temperature. In all cases we have succeeded only to cut small single crystalline samples, having dimensions of 1

1

4 mm

3

.

If the growing process was performed by pulling the crystals,

Fig. 1. K

2

Zn

2

(SO

4

)

3 crystal obtained by pulling from melt using the

Czochralski technique without rotating them, we were able to select single crystals of larger dimensions: 2



2



4

 mm

3

.

Further experiments are now in progress to obtain large single crystals of good quality using other techniques, such as zone melting or the Bridgman-Stockbarger method.

87

FLUORESCENCE ASSAY TO DETERMINE

METHOTREXATE PLASMA LEVELS IN HUMANS

Corina Ionescu

1

, D.Porutiu

1

, M.Nanulescu

2

1

U.M.F. “I.Hatieganu”, Cluj-Napoca, Dept.of Biochemistry

U.M.F. “I.Hatieganu”, Cluj-Napoca, Dept.of Cellular Biology

2

Clinic of Pedriatics, Cluj-Napoca

Advances in biology and medicine are no longer limited by available analytical techniques. Today, the biologists and physicians require not only diverse analytical procedures, but extremely sensitive as well, since they are continually examining intracellular mechanisms and investigating the functions of chemical agents which are active in extremely low concentrations in tissues.

The purpose of this study is to establish the conditions of determining plasma levels of methotrexate, a high toxicity agent that makes necessary close chemical supervision during therapy and this requires specific and simple analytical methods.

The drug methotrexate is highly fluorescent. Its fluorescence characteristics are: maximum excitation 270, 380 m

; maximum fluorescence 450 m

.

We utilised an oxidation procedure, the increment in fluorescence due to oxidation

(B-A) ( measured at the same wavelength settings) is proportional to the methotrexate concentration.

Limit of detection: 0,005

 g/ ml.

Excepting the extremely great sensibility, the method is valuable allowing the monitorization of plasma levels during therapy and performing pharmacokinetic studies as well.

88

PROTON NMR RELAXIVITY OF BLOOD SAMPLES

IN THE PRESENCE OF SOME GADOLINIUM AND

DYSPROSIUM COMPOUNDS

I. Coroiu

1

, Al. Darabont

2

and M. Bogdan

3

1

Technical University, 3400 Cluj-Napoca, Romania

2

Babes-Bolyai University, 3400 Cluj-Napoca, Romania

3

National Institute for Research and Development of Isotopic and Molecular

Technologies, 3400 Cluj-Napoca, Romania

Introduction

The use of some new compounds in MRI tissue and blood characterisation based on nuclear spin relaxation time measurements cannot be sustained until the molecular sources of these variations are understood. Tissues and blood are complex molecular systems with complex NMR properties. A better comprehension of the molecular basis of relaxation offers the possibility to predict the changes expected for a given pathology. The purpose of this contribution is to evidence the different relaxation characteristics of some gadolinium and dysprosium compounds in the presence and absence of the blood and to give a possible explanation about the molecular processes that cause the change's occurrence.

Results and discussions

Some gadolinium and dysprosium compounds such as: Gd-CIT (gadolinium citrate),

Dy-DTPA (DTPA-diethylenetriamine pentaacetic acid), iron oxide - gadolinium oxide (or dysprosium oxide)- dextran complexes were prepared. The longitudinal T

1

-1

and transverse T

2

-

1

relaxation rates' measurements have been carried out as a function of molar concentrations.

All measurements have been made at room temperature (about 25°C) and the proton Larmor frequency

 o

=90MHz. The pulsed NMR spectrometer utilised was a commercial Bruker

SXP4/100 spectrometer. Transverse relaxation rates measurements have been made using the

Carr-Purcell method, while longitudinal relaxation rates measurements using the inversion recovery pulse sequence, 180

-

-90

. The accuracy was about 2-3% for the longitudinal relaxation rates and about 5-7% for the transverse relaxation rates. R

1

and R

2

relaxivities, in mM

-1 s

-1

were determined from the least-squares determination of the slopes of plots 1/T

1,2 versus compound molar concentration, using at least five independent measurements at several concentrations between 0 and 2mM.

Increasing in R

2

relaxivity observed for dysprosium compounds in the blood presence can be explained by PRE effect. The largest gain in R

2

relaxivity seems to imply a noncovalent binding to proteins and an anisotropic motion. Since the protein-compound binding energies are likely determined by a number of relatively small contributions (such as electrostatic, hydrogen-bonding, Van der Waals and hydrophobic forces) from different groups on complex, these interactions may result in less internal flexibility and higher relaxivity than when the compound is attached to a single residue on the protein surface. The major part of the relaxivity probably stems from hydrogen-bounded water molecules in the second co-ordination sphere. In the opposite case, the gadolinium compounds relaxivity R

1

decrease in the presence of the blood and that implies probably a covalent binding to proteins, high degree of internal flexibility and a low number of bounded water molecules.

We hope that these compounds should be used for cancer cells targeting and for cancer treatment with the new method:

magnetic fluid hyperthermia

(MHF).

89

LIGAND EFFECTS IN THE IR AND EPR SPECTRA OF

SOME CR(III) TRIS-DITHIOPHOSPHONATES

O. Cozar

1

, R. Micu-Semeniuc

2

, L. David

1

, D. Ristoiu

1

, Crăiţa Bălan

1

, C. Agut

3

1

"Babeş-Bolyai" Univ., Dept. of Physics, , 3400 Cluj-Napoca, Romania

2

"Babeş-Bolyai" Univ., Dept. of Chemistry, 3400 Cluj-Napoca, Romania

3

University of Oradea, Dept. of Science, 3700 Oradea, Romania

Cr(III)

 tris[4

 metoxyphenyl

O

 alkyl]

 dithiophosphonate complexes (alkyl=methyl, ethyl, ipropyl, n-propyl) were prepared and investigated by UV-VIS, IR and EPR spectroscopies.

Electronic spectra of these complexes show two bands at 13620-14000 cm

18310-18500 cm

-1

(

4

A

2g

(F)

4

T

2g

(F) and

-1

(

1

) and

4

A

2g

(F)

4

T

1g

(F) transitions. The third band (

4

2

) assigned to

A

2g

(F)

4

T

1g

(P)) expected to be in the UV region is obscured by the chargetransfer and ligand-specific bands. The second band (

2

) shows a shoulder at 18780 cm

-1 which may be explained by a small distortion from the ideal octahedral symmetry because of the Jahn-Teller effect, spin-orbit coupling and to the mixing of neighbouring quartet-doublet states. The position of the third band and the spectral parameters (B

424,

=0.41 and

3

=29875-29955 cm

-1

) were calculated using a value of 918 cm

-1

for the interelectronic repulsion constant.

The shifts of vibrations bands with A

1

(

P-S

+

P-O

) and B

2

(

P=S

) symmetries confirm a bidentate coordination of dithiophosphonate anions. The shift of B

2

frequencies can also be related with the decreasing of the bonding order of P=S group as a consequence of the negative charge density displacement from sulphur atom to metal ion by coordination.

Fig. 1 EPR spectra of Cr(III)

tris[4

metoxyphenyl

O

R]

dithiophosphonate complexes at room temperature

The shape of the EPR spectra (Fig.1) changes with the length of the alkyl radicals and a more resolved fine structure typical for isolated Cr

3+

ions in a pseudo-octahedral geometry

(mononuclear species) occurs. At g eff

2, a broad band characteristic of the strong exchange coupled Cr(III) ions prevails. The number of clustered ions decreases with the dimension of alkyl radicals because the distance between chromium ions increases too. The zero-field splitting parameters range into 700-813 G domain, showing a small distortion of the octahedral Cr(III) environment.

90

IR AND EPR STRUCTURAL INVESTIGATIONS OF

SOME CU(II)-COMPLEXES WITH ANTI-INFLAMMATORY

DRUGS

O.Cozar

1

, I.Bratu

2

, L.David

1

, V.Chiş

1

, J.P.Havenne

3

and P.Legrand

3

1

"Babes-Bolyai" Univ., Dept. of Physics, 3400 Cluj Napoca, Romania

2

National Institute for Research and Development of Isotopic and Molecular Technologies,

3400 Cluj Napoca, Romania

3

USTL Lille, LASIR, 59655 Villeneuve d'Ascq, France

Copper(II)- complexes of some anti-inflammatory drugs have been found to be more potent and desirable drugs than their parent drugs

1

. The following Cu(II)-complexes with some anti-inflammatory drugs were prepared and investigated by IR and EPR spectroscopic methods: [Cu

2

(aspirinate)

4

](H

2

O)

2

, [Cu

2

(indomethacin)

4

](H

2

O)

2

, [Cu

2

(ibuprofen)

4

](H

2

O)

2 and [Cu

2

(piroxicam)

4

](DMF)

2

, in order to estimate the local structure changes by the presence of this transition metal ion.

The IR spectra of the anti-inflammatory drugs and their Cu(II) complexes allowed us to establish two types of vibrations involved in complexation:

i)

vibrations whose frequencies are modified by complexation and

ii)

new stretching vibrations such as

(Cu

O) and other combination bands.

The asymmetric and symmetric stretching vibrations of the COO

group appear in the

1550

1760 cm

-1 region. After complexation, an appreciable shift in frequency was observed, in agreement with the contribution to the coordination.

The values of the shifts for the COO

group in metal complexes are: 130 cm

-1

for Cu-

Aspirinate, 110 cm

-1

for Cu-Indomethacin and 140 cm

-1

for Cu-Ibuprofen, respectively.

CH

2

Some vibrations such as the asymmetric and symmetric vibrations of the CH

3

and groups, do not change their frequencies values after Cu(II) complexation. The bands assigned to these vibrations appear in the 2800

3000 cm

-1

region.

Powder EPR spectra of Cu-Aspirinate, Cu-Indomethacin and Cu-Ibuprofen complexes suggest the presence of two types of dimmeric species. One of them is characterised by strong antiferromagnetic exchange interaction (J = 300 cm

-1

) similar with those evidenced in the Cu-Acetate like dimers. The other specie is characterised by a larger metal-metal distance (

4-5 Å) and the dipolar spin-spin coupling. The ratio between these two types of binuclear species is depending on the ligand nature. Thus, in the Cu-Aspirinate compound the first dimeric species prevails whereas in the Cu-Ibuprofen, the second one dominates. In pyridine and dimethylformamide solutions, the values of isotropic parameters suggest the presence of Cu(II) pseudotetrahedral monomeric species. The anisotropic spectra with four hyperfine lines in the g

II region and a strong signal in the g

region were obtained for the adsorbed solutions on NaY zeolite. Four different monomeric species with various chromophores and local symmetry were evidenced in these solutions adsorbed on NaY zeolite. The nonsteroidal ligand molecules are partially or completely substitued by solvent

(DMF or Pyridine) molecules.

91

SPECTROSCOPIC INVESTIGATIONS OF

POLYOXOMETALATE K

19

[U

2

KAS

4

W

40

O

140

]

42H

2

O COMPLEX

L. David

1

, O. Cozar

1

, I. Bratu

2

, C. Crăciun

1

, M. Rusu

3

1

"Babeş-Bolyai" Univ., Dept. of Physics, 3400 Cluj-Napoca, Romania

2

National Institute for Research and Development of Isotopic and Molecular

Technologies, 3400 Cluj-Napoca, Romania

3

"Babeş-Bolyai" Univ., Dept. of Chemistry, 3400 Cluj-Napoca, Romania

The uranium complexes with polyoxometalates (POM) are especially investigated for their applications for stocking the radioactive products. The K

19

[U

2

KAs

4

W

40

O

140

]

42H

2

O complex has been investigated by electronic, IR and ESR spectroscopy.

The most affected IR bands by the uranium complexation are those of W-O terminal bonds. Thus,

 as

(W=O d

) and

 as

(W-O a

) which appear at 953 cm

-1

; 973 cm

-1

and

765 cm

-1

respectively in the IR spectrum of the ligand are shifted at 960 cm

-1

and 740 cm

-1

respectively into the complex spectrum.

These indicate that each U(IV) ion coordinate one {AsW

9

} Keggin unit and two bridging

WO

6

octahedra, being surrounded by 8 oxygen atoms. IR spectrum of the complex contains an additional band at

 as

1133 cm

-1

, attributed to

(U-O), a proof of the uranium coordination at the ligand.

The electronic spectra in the visible region present one sharp band at 14730 cm assigned to

3

H

4

1

G

4

transition and a little band at 15440 cm

-1

(

-1

3

H

4

1

D

2

) which indicate the presence of distorted cubic local symmetry around the metallic ion.

The ultra-violet absorption bands centred at 47392 cm

-1

in the free ligand and at

45043 cm

-1

in U(IV)-POM complex spectra are assigned to p  -d  electronic transitions into the W=O bonds. The broad bands at

41700

38400 cm

-1

for the ligand and

43500

40000 cm

-1

for the uranium complex spectra are due to electron transition between the energetic levels of the three central tricentric bonds W-O-W.

ESR spectra show a small orthorhombic distortion of the cubic local symmetry around

U(IV) ions (g z1

=2.098, g y1

=2.089, g x1

 g x2

=2.067, g y2

=2.051, g z2

=2.031). The oxygen ions form two antiprism configurations. The U(IV) ion has a

5

multiplet in the ground state, which can be characterised by a S eff

=1 effective spin. Some small features indicate the presence of a little amount of trigonal distorted cubic species.

92

EPR INVESTIGATIONS OF CU(II) COMPLEXES WITH

5'-GMP AND 5'-CMP NUCLEOTIDES

O. Cozar

1

, I. Bratu

2

, L. David

1

, A. Hernanz

3

, M. de la Fuente

3

, Crăiţa Bălan

1

1

"Babeş-Bolyai" Univ., Depart. of Physics, , 3400 Cluj-Napoca, Romania

2

National Institute for Research and Development of Isotopic and Molecular Technologies, 3400

Cluj Napoca, Romania

3

Depto. de CC y TT Físico Quimicas, UNED, E-28040 Madrid, Spain

EPR investigations of EPR complexes with 5’-CMP and 5’-GMP allowed us to obtain some information concerning the metal-nucleotide interaction and the symmetry of the coordination polyhedra.

Powder EPR spectra of the Cu(II)-5’-CMP and Cu(II)-5’-GMP complexes (Figs.1 and

2) suggest different local symmetries around Cu(II) ions. For the Cu(II)-5’-CMP complex a square-pyramidal symmetry where the Cu(II) ions are pentacoordinated to an N atom and four O atoms, with g

II

=2.233 and g

=2.076 may be considered.

The spectrum of Cu(II)-5’-GMP shows that Cu(II) ions are pentacoordinated with a square-pyramidal symmetry also, but it presents a rhombic distortion of the coordination polyhedron. Each copper(II) square-pyramidal structural unit is magnetically isolated, having monomeric species behaviour.

Anisotropic EPR spectra with four hyperfine lines in the g

II

region and a strong absorption in the g

region were obtained for both studied complexes in aqueous solution adsorbed on SiO

2

zeolite. In the aqueous solutions of Cu(II)nucleotide complexes, the Cu(II) ions are mainly coordinated by oxygen atoms in a tetragonaloctahedral symmetry. The smaller value of g

II

(2.288) and larger

Fig.1

Single-crystal EPR spectrum of Cu(II)-5’-GMP

value of A

II

(160 G) obtained for the 5’-CMP complex compared with those of 5’-GMP complex, does not entirely exclude the contribution of the N(3) nitrogen atom to the coordination.

Accordingly, for the Cu(II)-5’-

CMP complex, the presence of the CuO

3

N chromophore in the

x

O

y

plane may be accepted.

The EPR spectrum obtained from a polycrystal of Cu(II)-5’-CMP (Fig.1) presents the hyperfine structure resolved in the (g

II

=2.287, A

II

=163 G) parallel region. The shape of this spectrum is characteristic for monomeric species having a distorted tetragonal-octahedral symmetry around the metallic ion.

93

EPR AND MAGNETIC SUSCEPTIBILITY STUDIES ON

SOME DIMERIC COPPER(II) COMPLEXES

1

O. Cozar

1

, L. David

1

, I. Bratu

2

, C. Cosma

1

, Cecilia Agut

3

"Babeş-Bolyai" Univ., Dept. of Physics, , 3400 Cluj-Napoca, Romania

2

National Institute for Research and Development of Isotopic and Molecular Technologies,

3400 Cluj Napoca, Romania

3

University of Oradea, Dept. of Science, 3700 Oradea, Romania

The dimeric compounds are excellent model systems for the study of magnetic interactions, having in the same time biological and catalytic applications.

The

[Cu

2

R

4

CH

3

OH

2H

2 copper(II)

O] (I) and [Cu

2

R

4

CH

3 p-clorbenzoates

COCH

3

2H

2

O]

(II), where R = (p-ClC

6

H

4

CO

2

) as well as their monomeric species which occur at 77 K have been investigated by

Fig. 1 Powder ESR spectrum of

(I) at room temperature

spectroscopic and magnetic measurements.

The powder ESR spectra of the both complexes at room temperature are typical for randomly oriented triplet state species having an axial symmetry (Fig.1) with a short

Cu-Cu distance, as in the other copper acetate like dimers.

The 77 K spectra exhibit a very intense signal in the central part of the magnetic field which is characteristic for axial monomeric species (Fig. 2) and a very weak absorption at g

4 which indicates the presence of a small amount of the initial dimeric specie.

The hyperfine structure from the parallel band is the superposition of features from two non-equivalent monomeric species, one with square-planar symmetry

(tetragonal D

4h

) and the other with octahedral symmetry given by the coordination of two water molecules along the

Oz axis.

The magnetic susceptibility measurements indicate a Curie-Weiss behaviour of the complexes.

The values of the magnetic moments 2.67

B

and

2.54

B

for complexes (I) and (II), respectively indicate a mixture of monomeric and dimeric species. The molar ratios between monomeric and dimeric species are 2:3 and 3:1 in complex (I) and

(II), respectively.

Fig. 2 Central part of the ESR

spectrum for complex (II) at 77

K

The values obtained for the molecular orbital coefficients by LCAO-MO method are

2

=

0.85,

2

=

2

= 0.95. The g

II

and A

II values of the two monomeric species were used for the calculus of the 2.6 Å distance between Cu

2+

and the apical water molecules.

94

C60 AND C70 FULLERENES IDENTIFICATION USING

INFRARED SPECTROSCOPY METHOD

Daniela Stoenescu, Nicoleta Cojocaru, Doina Stefanescu

Institute of Cryogenics and Isotopic Separation, P.O. Box 10,

1000-Rm. Valcea, Romania, e-mail: daniela @ns-icsi.icsi.ro

Fullerenes are the third allotrope form of carbon and they hold great potential for material science applications, such as semiconductors and microscopic engineering, and as new compounds for pharmaceuticals, polymers and chemical industry.

In this paper are presented experimental results of the C60 and C70 fullerenes mixture analysis, this mixture being obtained by extraction and separation from raw soot of graphite.

C60 and C70 fullerenes spectra were scanned and clearly identified by FT-IR spectroscopy, which is an analytical technique based on vibrations of the atoms of a molecule round the balance positions.

Absorption FT-IR spectra were obtained using the KBr pellet method. The instrument is a MAGNA-IR 750 NICOLET Fourier transform infrared spectrometer (FTIR). The spectra were recorded in the 4000-400 cm

-1

spectral range with a resolution of 2 cm

-1

and the pellets containing is by 0.5 soot extract. The peaks positions (cm

-1

) attributed to C60 and C70 and their features were referenced against the spectrum of fullerenes by 99.88 % concentration.

95

CRYSTAL STRUCTURE OF LANTHANUM

SULPHATE ENNEAHYDRATE

Al.Darabont

1

, C.Neamtu

2

, Gh.Borodi

2

1

Faculty of Physics, ”Babes-Bolyai” University, 1 M.Kogalniceanu St., 3400

Cluj-Napoca, ROMANIA (e-mail: darabont@L30.itim-cj.ro)

2

Institute of Isotopic and Molecular Technology, 65-103 Donath St., P. O. Box

700, RO-3400 Cluj-Napoca 5, ROMANIA (e-mail: cneamtu@L30.itim-cj.ro)

The present paper describes the crystal structure determination of lanthanum sulphate enneahydrate (La

2

(SO

4

)

3

.

9 H

2

O) single crystals by X-ray diffraction methods.

Single crystals of appropriate dimensions (1

2

1 mm

3

) for these studies were obtained by the slow evaporation of a saturated aqueous solution of La

2

(SO

4

)

3

.

9 H

2

O.

The single crystals were oriented in a direction of a given symmetry (crystallographic axis) by the Kulpe method. After the determination of the accurate orientation, we calculated the value of the lattice constant in this direction (for instance

a

) using the rotation pattern.

The values of the other lattice constants (

b

and

c

) and the angle between these two axes were determined on the basis of the Weissenberg pattern. We found a set of three directions that give the consistence values for the unit cell characteristics, which are:

a

= (9.597

0.05)Å,

b

= (9.956

0.05)Å,

c

= (17.482

0.05)Å,

=

=

= 90 o

.

From these values and using the experimentally determined value of the density,

= 2.7953 g/cm

3

, we deduced that the unit cell contains 4 molecules of

La

2

(SO

4

)

3

.

9 H

2

O.

The above mentioned results, as well as the symmetry elements and the systematic absences of the

Weissenberg patterns of the zero layer lines, show that the La

2

(SO

4

)

3

.

9 H

2

O single crystals obtained by us have:

 an orthorhombic crystal system;

 a C type lattice; the mmm Laue symmetry group;

 the following possible diffraction symbol and space group: MM. C oca and C oca

. molecules in the unit cell of La

2

(SO

4

)

3

The possible positions of the atoms and

.

9 H

2

O are presented in the enclosed figure.

96

DIPOLE MOMENTS OF SOME P-HALO-BENZOYL-

PYRIDAZINIUM PHENACYLIDS.

EXPERIMENTAL AND THEORETICAL STUDY.

M.Cotlet, Dana Dorohoi, G. Singurel and S.Filoti

“Al.I.Cuza”University, Faculty of Physics, Bd. Copou nr.11, 6600 Iasi

The methods used by us for dipole moment estimation are:

- solvent influence on the electronic absorption spectra.

- dielectric constant and refractive index measurements at different concentrations of the solute in a non-polar solvent.

- quantum mechanical calculations.

3-(p-Halo)-benzoyl-pyridazinium phenacylids dipole moments were determined by the three menthods mentioned above.

Ylid

Table1 The studied ylids

Structure

1

2

3

Ylid

1

2

3

3-(p-chloro-phenyl)-pyridazinium benzoyl methylid

3-(p-bromo-phenyl)-pyridazinium benzoyl methylid

3-(p-bromo-phenyl)-pyridazinium p-methoxy-benzoyl methylid

Table 2 Dipole moments of the studied ylids

Dipole moment (D)

Spectral CNDO INDO AMI PM3

3.513

3.510

3.836

DKmethod

2.483

2.460

2.710

6.863

6.684

6.888

8.316

6.530

6.418

3.818

3.819

4.384

3.940

3.979

4.525

The obtained values are in accordance with the values obtained by spectral means for related compounds.

There are some differences between the values obtained by different methods because accuracy varies both with the apparatus accuracy and with the hypothesis of the theoretical model chosen to estimate the dipole moment.

For example, the specific interactions that can appear in the pyridazinium ylids solutions are neglected in the theories about the solvent influence on the electronic spectra. On the other hand, the theoretical results obtained by molecular orbital theory in different approximations are made for an isolated molecule and experimental results are obtained for the pyridazinium ylids in solutions.

Selected references

97

SPECTRAL STUDY OF THERMAL 3+3 DIPOLAR

DIMERIZATION OF CARBANION MONOSUBSTITUTED

PYRIDAZINIUM YLIDS

Dana Dorohoi, V.Melnig and M.Cotlet

“Al.I.Cuza” University, Faculty of Physics, Bd. Copou, nr.11, 6600 Iasi,

Romania

All carbanion monosubstituted pyridazinium ylids are more stable than those with a disubstituted carbanion. The stabilising factors of the pyridaziunium ylids are: the coulombian interactions between the electric charges from the ylid bond, the delocalisation of the electronic charges on the ylid carbanion substituents and the resonant structures of these molecules. The higher the electron charge delocalisation degree is, the bigger their stability becomes.

The carbanion monosubstituted pyridazinium ylids are very sensitive both to the carbanion structure and to the solvent nature visible electronic absorption band. This band, due to an intramolecular charge transfer from carbanion to heterocycle, can be considered as an indicator of the ylid inactivation by 3+3 TDD. The catalytic role of the visible light was concomitantly shown in.

To study 3+3 TDD, the spectral recordings in visible range were made, at equal intervals of time, in two ways. Between the recordings, in the first case the samples were continuously lighted at 21500 cm

-1

(corresponding to ICT band maximum), while in the second one, samples were not irradiated.

A loop kinetic mechanism of the process of 3+3 TDD for the studied ylids was proposed. In an aprotic solvent, this process can be explained by the participation of the lone electron pair of the carbanion in covalent bond with the proton of –CH groups located near the azo-atom from the heterocycle.

The estimation of the constant rate of 3+3TDD ( as being in the range [0.06019-

0.37619]l/mol.s in the case of the continuously irradiated samples between the recordings, and [0.00420-0.02531]l/mol.s for the samples nonlighted between the recordings) indicates that this reaction is of the second order and that the carbanion monosubstituted pyridazinium ylids with an electron repulsive substituent at the carbanion are more stable than those having an electron acceptor substituent.

Quanto-mechanical calculation of the energy in the ground state of the 3+3 dimmers show that the difference between the double of the ylid total energy and the dimmer total energy is of the same order of magnitude as the rotational energy of the ylid molecules. This fact proves that the light catalytic role in 3+3 TDD is based on the intramolecular charge transfer and non-radiative relaxation process. Information about the configuration of the dimmer ground state was also obtained.

98

SPECTRAL STUDY OF 4-STYRYL COUMARINE

DERIVATIVES

Dana Dorohoi

1

, G.Singurel

1

, M.Cotlet

1

, S.Filoti

1

,

Tatiana Nicolaescu

2

,Catinca Simion

2

and R.Gradinaru

2

1.“Al.I.Cuza” University, Faculty of Physics, Iaşi, Bd. Copou, nr.11, 6600 Iasi,

Romania, E-mail ddorohoi@uaic.ro

2.“Al.I.Cuza” University, Faculty of Chemistry, Iaşi, Bd. Copou, nr.11, 6600

Iasi, Romania

Some new derivatives of 4-styryl-coumarine (4-SC), obtained by the condensation of aromatic aldehydes with coumarine derivatives, were spectrally analysed to establish correlation between experimental and molecular parameters. The viologene compound, 1,4-

[2-(4-dimethyl-amino-phenyl)-ethenyl]-7-hydroxy-coumarine was spectrally characterised and used as a chemical pH-sensor.

Some 3-styryl and 4-styryl coumarine are mentioned in literature as important fluorescent compounds.

IR, NMR, DR spectra, electronic absorption and fluorescence spectra were recorded.

In order to build theoretically the electronic energy levels of 4-SC and to compare to those experimentally obtained, a quantum chemical calculation was performed using a PM3

(Parametric Model number 3) Self Consistent Field method with 0.01 iterative step for the molecule considered in vacuum. An optimisation of the molecule geometry was performed before.

4-SC derivatives participate to dipolar interactions in condensed medium, fact that induces differences between the computed and experimentally obtained electronic spectra.

A visible band forbidden in the case of isolated molecule becomes allowed in condensed state.

The substituent Chlorine induces major changes in the visible electronic absorption and diffusive reflection spectra of 4-SC and -N(CH

3

)

2

determines an increase of the number of the bands in the electronic spectra.

99

DIPOLE MOMENTS AND POLARIZABILITIES IN THE

EXCITED STATES OF SOME CARBANION DISUBSITUTED

PYRIDINIUM YLIDS

Dana Dorohoi

1

, Magdalena Postolache

1

, Daniela Ionescu

2

Dan Dimitriu

1

and M.Postolache

2

1.Al.I.Cuza University, Faculty of Physics, Iaşi, Bd. Copou, nr.11, 6600 Iasi,

Romania, E-mail ddorohoi@uaic.ro

2.G.Asachi Technical University, Iaşi, Bd. Copou, nr.11, 6600 Iasi, Romania

In order to estimate the dipole moments and polarizabilities in the excited state of some pyridinium ylids we used a formula resulting from Abe cell model [1] developed for a simple liquid:

l

0

 

e

2

(

u

)

g

2

(

u

)

C

3

4

N

A

M

v v

(

v

v n v

2

)( 2

(

n v

2

v

2 )

n v

2

)

3

2

C

I g

(

u

)

g

I g

(

v

)

(

u

)

hc

I g

(

u

)

l hc

(

v

)

g

(

u

) (

v

)

I g

e

(

u

)

3

2

C

I g

I g

(

u

)

I g

(

v

)

I g

(

v

)

(

u

)

g

In this relation the index “u” reefers to the spectrally active molecules and “v”- to those of solvent; g and e describe the ground and the excited states of the molecules and

is the wave number of the maximum of the pyridinium ylids electronic absorption band, measured in liquid solution (l) and in vapour state (0);

represents the dipole moment and

- the polarizability; n and

are the refractive index and the dielectric constant of the solvent.

C is a constant dependent on the molecular weights and on the density of the molecules.

The ionisation potential and the value of the dipole moment in the ground state of pyridinium ylid were estimated by PM3.

The visible electronic absorption band of the studied pyridinium ylids was registered in aprotic solvents with known parameters mentioned above.

Using a Multireg BASIC program, we determined both the dipole moments in the excited state and the polarizabilities in the ground and the excited states of pyridinium ylids.

The obtained data indicate that, in the intramolecular charge transfer process, the dipole moment of pyridinium ylids decreases and changes its sense, concomitantly with an increase of the molecular polarizability. The values for the dipole moments of pyridinium ylids are in good agreement with the values obtained in for some pyridazinium ylids.

100

CORRELATION OF THE GEOMAGNETIC ACTIVITY

AND THE BLOOD SERUM CHARACTERISTICS

Cristina Dragu, V. V. Morariu

National Institute for Research & Development of Isotopic and Molecular

Technologies, Cluj-Napoca

Purpose:

We are carrying out a project at the level of the city of Cluj-Napoca to check weather blood characteristics of ambulatory patients at the city-state Polyclinic are correlated or not with the geomagnetic activity. While this project involves the correlation of a large number of blood characteristics with the geomagnetic activity, the present communication refers only to the serum proteins.

Materials and Methods:

Human blood was collected by venipuncture from the incoming ambulatory patients and the serum proteins ( albumin, alpha, beta and gamma globulin) have been analysed by electrophoresis. A daily average of each of the serum protein was calculated. It is understood that no data were available for the weekends days as well as for some holidays. These data have been compared to the daily average magnetic activity. A full analysis requires a correlation procedure between the two data sets. However, such a correlation analysis should be done at various time lags since effects of a magnetic storm could trigger effects after some time interval. In the present communication, we have adopted a preliminary procedure: Both the clinical laboratory data and the daily geomagnetic activities for the 1998 period, have been analysed in respect to the data distribution. We have hypothesised that similarity of the data distribution could be a general indicator that the two data sets are related in some way.

This preliminary fast procedure, does not require successive trials of the correlation of two data sets at different time lags; such a procedure will be applied in the future.

Results:

None of the data had a simple distribution. Generally the distributions varied between gaussian and exponential. The time series representing the daily average geomagnetic activity in 1998 had somewhat more of an exponential like distribution while the clinical data appeared to be more like of a gaussian distribution. The most resembling distribution with the geomagnetic activity appeared to be the values of SE of the beta fractions. In other words, the greatness of the fluctuations of the beta fractions appeared to be somewhat correlated with the geomagnetic activity. This correlation appeared at seasonal level only i.e. greater fluctuations in the spring and autumn, while no direct correlation could be clearly noticed with individual magnetic storms.

Conclusions:

The geomagnetic activity in 1998 appeared to be somewhat correlated with the amplitude of the serum beta globulin fluctuations.

101

SELECTIVE MEMBRANES FOR H

2

AND He

T.D. Silipas and P.V. Mercea*

National Institute for Research and Development of Isotopic and Molecular

Technologies, Cluj-Napoca, Romania

*Industriebaratung und Vertretung-Germany

The highly selective membranes for H

2

and He by using deposition of metallic and inorganic films on membranes’ surface, as well as the results obtained in the study of gas permeation through these membranes are presented in this paper. To determine the gas permeability through a polymer membrane and composites membranes under steady-state conditions (in agreement with the ASTM D-1434/82), the manometric method was used.

PET

Pd

SiO

2

Palladium, of at least 99.95% purity, was deposited on a 30

 m thick poly(etyleneterephtalate) (PET) membrane, produced by a Romanian factory. The permeation of He, H

2

, CO

2

, Ar and N

2

at 50 o

C through PET membranes metalled with Pd (MPM) was studied. Because He, CO

2

, Ar and N

2

do not dissolve into Pd at 50 o

C and a pressure of about

70 cmHg, and H

2

does, we had the possibility to investigate both effects by studying the permeation of these gases through MPM.

The gas-selective effect of MPM essentially depends on the ability of a given gas to dissolve in, and diffuse through, the metal layer itself. For PET membranes metalled with Pd

(MPM), the permeability ratio, H

2

/N

2

, is about four times higher that the same ratio in simple

PET membrane.

The high permeation selectivity of SiO

2

- as fused quartz - at 600-700 o

C for He versus

N

2

and CH

4

is well known and is already used for the ultrapurification of He in laboratory equipment. These facts motivated our investigations, even at the moderate temperature of

50 o

C, of the permeation of simple gases through a PET membrane deposited with a thin layer of SiO

2

.

It was found that, even at a moderate temperature of 50 o

C, an amorphous layer of

SiO

2

deposited in vacuum, by radiofrequency sputtering, increases significantly the permeation selectivity for He.

102

SPECTROSCOPIC AND MAGNETIC BEHAVIOUR OF

SOME BORATE GLASSES CONTAINING EUROPIUM IONS

E.Culea, I.Bratu* and Tania Ristoiu

Technical University of Cluj-Napoca, Romania

* National Institute for Research and Development of Isotopic and Molecular

Technologies Cluj-Napoca, Romania

Glasses containing rare-earth ions are the subject of a great deal of scientific interest due to their important optical, magnetic and mechanic properties.

In order to extend the available information on structural and magnetic behaviour of glasses containing rare-earth ions, we investigated the xEu2O3(1-x)Na2B4O7 vitreous system, noted xEB, with 0.01

 x

0.30, using IR spectroscopic, density and magnetic measurements.

IR spectra were recorded in the 500-2100 cm

-1

range. Density measurements were performed using the picnometric method. Magnetic measurements were performed in the temperature range from 4 to 300 K and fields up to 75 kOe.

The increase of the Eu2O3 content, x, of the xEB glasses produces modifications of their IR spectral features. The evolution of the IR spectral features of the xEB glasses as a function of x is related to structural changes determined by varying x. The structural changes produced by increasing x , as suggested by the evolution of the absorption bands at 870 and

1260 cm

-1

, consist mainly in a decrease of the amount of boroxol groups and BO

3

structural units. The IR data obtained for the xEB glasses suggest that the europium ions play a network modifier role in these glasses. This behaviour of europium ions was not reported till now.

The increase of the europium oxide content of the xEB glasses, x, leads to the increase of the density due to the higher number of europium ions accommodated in the vitreous matrix.

The density-x relation is not linear and shows an important minimum at x=0.20. This feature is related to the influence exerted by the structural changes on the density-x relation.

Magnetic behaviour of oxide glasses containing europium ions is due to the presence of both

Eu

3+

and Eu

2+

valence states. In order to determine the fractions of europium ions in the mentioned valence states the magnetisation isotherms of xEB glasses, obtained at 4, 10 and

15 K, were analysed. For external magnetic fields, H, where 20

H

75 kOe, the magnetisations depends linearly on the field. This behaviour is due to a superposition of two contributions, one arising from a paramagnetic component, the other arising from a magnetic ordered phase, due to the presence of Eu

2+

ions coupled by weak superexchange interactions.

The spontaneous magnetisation at 0 K, obtained by extrapolation of the values measured at

4 K according to a T

3/2

law, were used to determine the amount of Eu

2+

ions. The fractions of europium ions in the +2 valence state were found to be very small, ranging between

1.72% and 2.38% of the total number of europium ions. Thus, the magnetic behaviour of xEB glasses is due to the presence of europium ions mainly in their +3 valence state and in small amounts in their +2 valence state

103

X-RAY STRUCTURAL DETERMINATION FOR 5'-

CMP·Na

2

MONONUCLEOTIDE

Gh. Mihailescu

1

, Al. Darabont

2

, Gh. Borodi

1

, I. Bratu

1

1

National Institute for Research and Development of Isotopic and Molecular

Technology, P.O. Box 700, R-3400 Cluj-Napoca 5, Romania

2

”Babes-Bolyai” University, Dept. of Physics, Cluj-Napoca, Romania

The nucleosides and nucleotides have attracted considerable attention not only because they are building blocks of the nucleic acids, DNA and RNA, which are the centre of life processes, but also because they are cofactors and allosteric effectors for many of the fundamental enzymatic reactions. Cytidine 5’-monophosphate (5’-CMP) is one of the four common ribonucleotides which make up ribonucleic acids (RNA’s).

The 5’-CMP Na

2

compound was crystallised by the slow evaporation method from water-methanol solution using three recrystallisation processes. There were obtained transparent single crystals of about 2 x 4 x 1-2

mm

. From the Laue method, we put in evidence the presence of the 2-fold symmetry. By Kulpe method the crystal was oriented along the 2-fold axis and by the oscillation method it was determined the periodicity along this direction,

b

=8.899Å. The spot-layer of superior order proved to be symmetrically disposed relative to the spot layer of zero order indicating again the 2 order symmetry. From the zero layer Weissenberg pattern resulted the reciprocal lattice parameters

a

*=0.137,

c

*=0.122 and

*=85.5

. It results

a

=14.08 Å,

c

=15.83 Å and

=94.5

. By indexing the powder diffraction pattern there were obtained more precise the lattice parameters. The compound density was experimentally determined by the picnometric method,

 exp

= 1.999

g/cm

3

. From the lattice parameters and the experimental density resulted the molecules number in the unit cell:

Z

= 4.

Therefore, the 5’-CMPNa

2

compound crystallises in the monoclinic system, the space group P2/m with 4 molecules per unit cell and the lattice parameters are:

a

= 14.10Å,

b

=

8.9Å

c

= 16.05 Å and

= 94

.

104

PHOTOPYROELECTRIC STUDY OF EDIBLE OILS’

ADULTERATION

D. Dadarlat, G. Nagy, U. Stanescu, C. Bele a)

, A. Pasca, D. Bicanic b

)

National Institute for Research and Development for Isotopic and Molecular

Technologies, Cluj-Napoca 5, PO Box 700, 3400 Cluj, Romania a)

University of Agriculture Sciences and Veterinary Medicine of Cluj-Napoca,

Manastur Str. 3-5, 3400, Romania b)

Wageningen Agricultural University, Dept. of Agric. Engng and Physics,

Agrotechnion, Bomenweg 4, 6703 HD, Wageningen, The Netherlands

During last years, fats and especially edible oils were the subject of an intensive study, connected with problems as quality, spoilage and adulteration. Several methods as photopyroelectric (PPE) and classical spectroscopy, photoluminescence, optothermal windows and gas chromatography were used in order to check for oxidation, reduction of chlorophyll, or compositional changes.

In this paper, we propose the PPE calorimetry as a suitable method for olive oil adulteration. The main method for olive oil adulteration is to mix it with “chipper” oils as sunflower or safflower. The PPE detection of olive oil adulteration is based on the measurement of freezing point. The standard PPE configuration was used in this study.

15

14

13

12

11

10

heating

cooling

Olive oil, f = 3 Hz

2

0

-2

-4

-10

-12

-6

-8

6

4 mixture of olive oil with safflower oil

-30 -20 20 30

0 10 20 30 safflower oil concentration (%)

40 50

-10 0

Temperature (C)

10

Figure 1.

Figure 2.

Figure 1

presents a typical temperature scan for the amplitude of the PPE signal for pure olive oil, and

Figure 2

the phase diagram for different mixtures of olive-safflower oils.

One can observe a clear decrease of the freezing point with increasing safflower oil concentration.

As a support for the results obtained by PPE calorimetry, we performed gas chromatography analysis too, for pure olive oil, pure safflower oil and for three samples containing mixtures of safflower oil in olive oil. The mixturing concentrations for the two oils given by the gas-chromatography analysis were near to the theoretical ones (6.4%, 17.6% and 37.2% safflower oil in olive oil instead of 5%, 15% and 35%).

105

CHEMICAL METHODS FOR THE STUDY OF

MICROWAVE PLASMA GENERATED IONS DISTRIBUTION

G. Nagy, E. Surducan, C. Neamtu, V. Surducan

National Institute for Research and Development for Isotopic and Molecular

Technologies, Cluj-Napoca 5, PO Box 700, 3400 Cluj, Romania

The paper presents a new chemical method for the identification of the microwave plasma generated ions. We used organic dyes (methylen blue, phenil red, Congo red, methyl red, etc.) and inorganic compounds like ammonium bichromate ((NH

4

)

2

Cr

2

O

7

) and silver nitrate (AgNO

3

), adsorbed on inorganic support (silica-gel). The indicator samples were treated 5 - 10 minutes in microwave plasma, generated by three gases: argon, oxygen and air.

During the treatment, the indicators were changing their colour, turning to white or to lighter colour than the initial one.

In Figure 1 are presented two indicators (one based on organic dyes -

Congo Red

-

(fig.1.a) and one based on inorganic compounds -

Silver nitrate AgNO

3

(fig. 1.b)) before the treatment and after 5 minutes of treatment in microwave plasma generated by the three gases mentioned above.

4

4

3

3

2

2

1

1

a) Congo Red b) AgNO

3

Figure 1.

Indicators for microwave plasma generated ions before treatment (

1

) and after 5 minutes of treatment in different gases: air (

2

), oxygen (

3

) and argon (

4

). The arrow indicates the flow of gas-ions mixture.

This seems to be a very rapid and efficient method for identifying the ions flow from the microwave generated plasma.

106

INFLUENCE OF MICROWAVES AND ELECTRON

BEAM ON RED BLOOD CELLS

A. Hategan, D. Martin, A. Popescu, C. Butan

Institute of Atomic Physics, Magurele Bucharest P. O. Box MG-36, R-76900 e-mail: ahateg@ifin.nipne.ro

The effects of 6 MeV electron beam and of 2.45 GHz microwaves on the osmotic fragility of frozen cryoprotected human red blood cell membranes are presented. The changes in the properties of the red blood cell membranes were estimated by measuring the radiation induced haemoglobin release from the red blood cells (haemolysis) and the osmotic fragility of the membranes, determined by postirradiation induced osmotic stress. We obtained no haemolysis induced by accelerated electrons in the range 0-400 Gy, whereas the microwave irradiated red blood cells showed in the ranges 1-2 min and 400-500 W values of very small haemolysis, down to 50 % from the control. The osmotic stress experiments indicated a significant increase in the osmotic fragility for 200-400 Gy electron doses, whereas the 100

Gy irradiated sample showed a haemolysis down to 35 % from the control. Similarly, the microwave irradiated red blood cells showed values down to 60% from the control for (1 min, 850 W). Both radiations induced at definite parameters values of very small haemolysis, suggesting a stabilisation of the membranes and an increase in the osmotic resistance. Our preliminary results on simultaneous irradiation of the frozen red blood cells seem to indicate a significant contribution of the microwaves in haemolysis evolution, while the successive irradiation procedure did not allow so far a clear interpretation, further studies being necessary to elucidate the physico-chemical mechanisms induced.

EFFECTS OF ACCELERATED ELECTRONS ON

LACTATE DEHYDROGENASE

A. Hategan, D. Martin, C. Butan

Institute of Atomic Physics, Magurele Bucharest P. O. Box MG-36, R-76900 e-mail: ahateg@ifin.nipne.ro

Results on the influence of 6 MeV electron beam as well as the protective effect of D2O on the frozen lactate dehydrogenase enzyme at -3 C and -196 C are presented. The temperature gradient used to lower the temperature of the samples influenced the results, the minimum unfolding of the protein, showed in a minimal loss of the activity, being obtained with a two steps technique (-10 C/ -196 C). High energy electron irradiation of the frozen lactate dehydrogenase, independently on the procedure of freezing, in the dose range 0-300 Gy and

0-4.2 kGy leads to an insignificant respectively moderate (mainly down to 50%) decrease of the frozen enzyme activity. Suspension of the enzyme in 99.98% D2O protected the enzyme from freezing damage (20% activity remained instead of 0-5% without protection). Electron irradiation of the frozen protected enzyme in the range 0-600 Gy did not influence significantly the enzyme activity. The system studied showed a complex behaviour because of the superposition of freeze-thawing procedure effects on the irradiation effects, both molecular mechanisms being incompletely clarified yet.

107

MASS SPECTRA OF SOME NEW THIAZOLYL-1,2,4-

TRIAZOLES

Ileana Chirtoc, N.Palibroda and V.Zaharia*

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5, Romania

P.O.Box 700, 3400 Cluj-Napoca, Romania

*Department of Organic Chemistry, University of Medicine

and Pharmacy “Iuliu Hatieganu”

Thiazolyl-thiazolo[3,2-b]-[1,2,4] triazoles

c, d

were obtained by transformation of thioethers

a, b

after treatment with H

2

SO

4

.

C6H5

N

N

N

NH

S

CO -R

CH2

C6H5

N

N

N

S

R

S

N

S

a c

C6H5

N

S

CH3

N

N

NH

S

CO -R

CH2

C6H5

N

S

CH3

N N

N S

R

b d

R : CH3, CH2Cl, C6H5

Mass spectra of thioethers and thiazolyl triazoles are presented. A Varian MAT 311 double focusing mass spectrometer was used. Fragmentation occurred under electron bombardment at 70eV. Samples were solid, introduced by direct inlet, evaporated by programmed heating up to 300 o

C.

The molecular ions are present in all spectra. In the case of R = CH

2

- Cl the loss of a chlorine radical or a neutral HCl is first to occur. For R = C

6

H

5

, both thioethers,

a

and

b

show the fragmentation of a [CO-C

6

H

5

] radical, m/z = 105. The triazoles for all R substituents show the main fragmentation of the thiazolic ring, loosing the m/z = 103, [C

6

H

5

-

C=N]

--

ion.

108

AN ATTRACTOR CONTROLS THE SPATIAL

FLUCTUATIONS OF HUMAN LYSOZYME

V. V. Morariu, Adriana Isvoran*, A. Negreanu-Maior

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O. Box 700, Cluj-Napoca 5, Romania

*West University of Timisoara, Faculty of Physics, 1900-Timisoara, Romania,

E-mail: adii@galileo.uvt.ro

The characteristics of attractor control of the fluctuations of the spatial coordinates of human lysozyme when it reacts with tetra-acetylchitotetraose have been detected. The autocorrelation functions for the changes in the spatial coordinates caused by realisation of the complex between human lysozyme and tetra-acetylchitotetraose show the damping expected for the control of an attractor and the Poincaré plots present regions that are preferentially occupied. The power spectrums are broad and the linear fitting of power spectrums represented in the double logarithmically scale show broadband profiles with 1/f

α

- like distributions that are typical for chaotic processes. The saturation of the integral correlation coefficients with increasing the number of coordinates in the phase spaces indicates the presence of attractors. The dimensions of these attractors are: 1,81±0,16 for the changes in x coordinates, 1,88±0,1 for the changes in y coordinates and 2±0,09 for changes in z coordinates.

THE INTEGRALE EQUATIONS OF MOLECULAR

FLUX DENSITY THROUGH VARIOUS PROFILE TUBES IN

LOW PRESSURE CONDITIONS

Simona Negru, Violeta Vrabie

Grupul Scolar de Gospodarirea Apelor si Prestari Servicii

Craiova, Str. Brestei, Nr. 87

In this paper, we shall analyse the particles density in various profile tubes which are passed over by a molecular flux in low pressure conditions. The problems is the same in porous mediums case in normal pressure conditions, the essential conditions is the molecules free path to be bigger than pores dimensions with some order size.

Our starting point is the balance molecular flux equation in a point situated in the interior surface of tube. This equation, which appears in speciality literature, has been used in our knowledges, only for cylindrical symmetry tubes. We are developing this theory also for rectangular and triangular profile tubes. For this, we justify the fact that particles density remains the same in a cross-section of tube. Next, we are showing that this integral equations are taking the same form for homotetyc tubes, which means that the solution of these equations can be used for a whole class of equivalent tubes. To solve these equations is necessary an iterative method.

In the end, we find the solution of these integral equations for same simple cases.

109

IN VITRO HUMAN BLOOD AGEING IN ZERO

MAGNETIC FIELD - THE OLIGOELEMENTS TRANSPORT

Lorelai I. Ciortea, V. V. Morariu

National Institute for Research and Development of Isotopic and Molecular Technologies,

P.O.Box 700, R-3400,Cluj-Napoca, Romania

The effect of the natural magnetic field on living matter, due to the geomagnetic field contribution, has received very little attention compared with the effect of exposure to increased intensities above natural level. However this is a question of interest since: (1) the fact that the natural magnetic field is a normal part of the environment in which life developed, and changes may have health implications; and (2) the absence of the natural magnetic environment is relevant for living matter in cosmic conditions. Earlier works in conditions of the zero magnetic field revealed its influence on living matter in terrestrial conditions. In this sense, alterations have been observed in the immune mechanism such as a reduction in the number of T lymphocytes and a significant increase in the peripheral leukocytes count.

The role of oligoelements in the immune system is well known: Cu helps strengthen the immune system, Zn helps bolster it and Mg deficit has implications in immunity. As we know by now that the immune system is affected by the absence of the normal geomagnetic field, we may assume that the balance of these oligoelements is also disturbed. Therefore, the aim of our work was to investigate the concentration of these ions into the blood serum following in vitro exposure to zero magnetic field.

The investigations were carried out on human blood collected from apparently healthy donors. The samples were kept in geomagnetic field conditions as controls and exposed in near null magnetic field conditions as probes for 48 hours.

The determination of ions concentration in blood serum were made daily by atomic absorption spectrophotometry technique. The natural magnetic field was compensated with a

Helmholtz coil system mounted on a wooden frame of 1.2m diameter. The reduction factor of the natural magnetic field was ~100.

The results revealed that: Mg efflux was inhibited in zero magnetic field conditions,

Zn influx was inhibited and Cu influx was stimulated.

The present results reveal that the lack of natural magnetic field can influence the oligoelements transport and this may have negative consequences on the immune system.

110

SPECTROSCOPIC TECHNIQUES USED IN

MONITORING THE ERYTHROCYTE SEDIMENTATION

PROCESS

Lorelai I. Ciortea, Mihai Chirtoc, Jean-Stéphane Antoniow

*

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O.Box 700, R-3400,Cluj-Napoca, Romania

*Université de Reims-Champagne-Ardennes: Laboratoire d'Energétique et d'Optique, BP 347, 51062, Reims Cedex, France

Erythrocyte sedimentation rate (ESR) is a simple clinical test performed by the wellknown Westergreen method. A new approach using an optical transmission method for locating the position of the interface between the erythrocyte sediment and plasma in human blood is presented. This spectroscopic method allows for online monitoring of the sedimentation on small sample quantities, during the whole process.

The method is based on the optical property of the erythrocytes to absorb selectively the light whereas the plasma layer is transparent. We consider the blood during sedimentation as a two-layer system: semi-transparent plasma layer above, which has an increasing thickness in time, and the sediment below, almost opaque, having an increasing concentration of red cells. During the sedimentation, the thickness of the plasma layer increases and the signal amplitude as well. Thus, the signal amplitude contains real time information on the sedimentation dynamics.

The experimental set-up uses uniform, front-side irradiation of the specimen. The blood sample was irradiated with a parallel yellow beam (

= 0.57

 m) emitted by a LED modulated electronically at 17 Hz. In this way it may be followed the interface between the clear component and the sediment. The light transmitted through the 2 mm thick sample is focused on a photodiode.

Before investigating the sedimentation of blood, two series of tests were performed: the first one with an Al foil, which simulates the sediment. The foil can be introduced gradually in the light beam, covering partially the empty cell. In this way it was demonstrated the linearity of the transfer function of the cell (height of the opaque zone vs. signal amplitude).

The second test was carried out with sample consisting of a suspension of latex spheres having a simple law for the sedimentation velocity (Stoke' s law), the latex sphere velocity being determined using experimental data. The theoretical value of the velocity was in agreement with the one determined from the experimental data.

After the tests, the device was used to monitor the sedimentation of whole blood. The samples were obtained from the patients some hours before the measurements, and were treated with sodium citrate to prevent coagulation.

Finally, it is presented the photopyroelectric (PPE) technique, another relatively new spectroscopic method used to monitor blood sedimentation. The typical time evolutions of the signal amplitude were almost the same for both methods.

Future work is in progress to correlate the presented method with the standard method.

111

QUANTITATIVE ANALYSIS OF

CHOLESTEROL IN EGG YOLK

Monica Culea, G. Ciurdaru, Mihaela Apetri, Carmen Gherman*, O.

Cozar*

S.C. Natex s.r.l. Cluj-Napoca, Romania

* University Babes-Bolyai, Cluj-Napoca, Romania

Free radical formation in the body is considered to play an essential role in the development of cancer and coronary heart disease by attack on biomolecules or the biomembrane. A source of protection of membrane against the oxidative damage can be found in many compounds contained by plants.

The aim of this work is to study the influence of some compounds from plants on the cholesterol level in egg yolk A method for quantitative analysis of cholesterol in egg yolk is presented. 5 mg of diosgenin, the internal standard, per gram of egg yolk, was added. The extraction was followed by methylation of fatty acids and gas chromatographic and gas chromatography- mass spectrometric analysis. The liquid-liquid extraction was performed in methylen chloride in an optimisation process of the amount of sample, extracting solvent volume, extraction temperature, extraction time. The extract was derivatized with methanol HCl 3M, at 60 o

C, 1h. A HP-1 capillary column, 30mx0.32mm, 0.25µm film thickness, in a temperature program: 50 o

C( 2 min) to 300 o

C(10min), with a rate of 10 o

C per minute. The regression curve used in cholesterol quantitation is shown in the figure.

112

Application was performed by feeding hen with buckthorn oil, soya, oat, protein.

A significant decrease of cholesterol of 20% was observed after 20 days, The precision gave CV lower than 5% for n=6.

LIVER FUNCTION MONITORING BY GC-MS

ANALYSES

Monica Culea

*

, M. Nanulescu

*

, Mirela Popa

**

, R. Mihalca

***

,

Lavinia Tomole

****

, O. Cozar

****

* NATEX s.r.l., Sos. Cluj-Oradea km8, P.O. Box 374, 3400 Cluj-Napoca,

Romania

** Paediatric Clinic lll, Cluj-Napoca, Romania

*** North University of Baia-Mare, Physics Department, str. Victoriei

76, 4800 Baia-Mare, Romania

****Babes-Bolyai University, Faculty of Physics, 3400 Cluj-Napoca, Romania

Introduction

Caffeine is a model compound for measuring liver function being almost exclusively metabolised by the hepatic microsomal enzyme system. Caffeine clearance, measured as the disappearance of the parent compound from the blood stream was validated as a novel approach for assessing hepatic microsomal function.

Materials and Methods

A gas chromatography-mass spectrometric (GC/MS) method in the selected ion monitoring mode (SIM), for caffeine levels determination in blood to children suffering of different forms of liver diseases is described. 10

 g/ml

15

N-theophylline has been used as internal standard. Extraction of caffeine and. 10

 g/ml internal standard was made with 2ml chloroform: isopropanol (20:1, v/v) and 0.5 g NaCl by stirring 1 min, followed by centrifugation 3 min. A Hewlett Packard GC/MS engine 5989B in the SIM mode, equipped with a HP-1 capillary column 30m

0.25mm diameter, 0.25 temperature program:200-250

C with a rate of 10

 m film support, in the

C/min, was used. The method was validated in the range 0-20

 g/ml caffeine.

Results

A dose of 4 mg/kg p.o. was used and blood caffeine concentrations were measured before dose and timed intervals at 0, 30min, 1, 3, 6, 9 and 12h. The method was applied for caffeine clearance and half-live time measured in 14 patients, three with cirrhotic and the others with chronic hepatitis and compared with control. The decreased metabolism observed in patients with various forms of liver disease correlated to the disease status. Caffeine clearance is affected by the reduction in the activity of the hepatic drug-metabolising enzymes and in the functioning hepatocyte mass. Significant impaired caffeine clearance compared with controls was observed in decompensated cirrhosis and elimination half-life was prolonged.

Conclusion

The GC/MS method used for caffeine determination in blood samples was rapid and precise. The SIM-GC/MS mode avoids interferences and leads to reliable results.

113

THE ROLE OF THE ELECTRIC FIELD PULSE

STRENGTH

AND DURATION IN THE BIOMEMBRANE

ELECTROPERMEABILIZATION PROCESSES.

Silvia Neamţu, I. Turcu, Cristina Dragu, C. Bindea

National Institute for Research and Development of

Isotopic and Molecular Technologies, Cluj-Napoca

Membrane electropermebilisation is described as a three-step process: the induction, expansion and resealing of the membrane pores under and after the electric field pulses action. This process is dependent on several physical parameters: the strength and length of the electric field pulse and the pulse number. To find the main contribution of the pulse strength and duration in the membrane electropermeabilisation steps, the effect of pulses with amplitude E = 4; 5 kV/cm and length

= 40; 100

 s in four combinations was investigated.

Experiments were performed on human erythrocyte suspension 1%. For cell electroporation, it has been used rectangular pulses, delivered by an electroporator equipment. Erythrocyte suspension has been processed in flux in a thermostated chamber at 4

C.

The extension of permeabilised area has been emphasised by haemoglobin efflux kinetic and manganese ions transport through erythrocyte electropermeabilised membrane at lower incubation temperature (4 C). The membrane resealing was tested after different incubation period at 37 C by the restoration of the membrane impermeability to manganese ions. The hemolysis degree due to haemoglobin efflux through the permeabilised membrane has been determined spectrophotometrically (410 nm) and the manganese ions concentration in the cell suspension, by atomic absorption spectrometry technique.

The kinetics of haemoglobin efflux and ions permeability depends on both amplitude and pulse length. Hemolysis degree and manganese influx increases with the electric pulse amplitude and at the same pulse strength, with pulse length. On the other hand, a similar haemoglobin and ions membrane permeability is noticed under the action of combination of higher amplitude - lower length (5kV/cm - 40

 s) and lower amplitude - higher length

(4kV/cm - 100

 s) respectively. These results prove the possibility to optimise the membrane permeability to molecules, using electric pulses with different combination of parameters, in order to obtain a desired membrane state.

The resealing process is found to be different for the same value of the membrane permeability. Keeping the pulse amplitude at lower value (4 kV/cm) and increasing the pulse length to 100

 s the membrane impermeability for the manganese ions was obtained only after 1 hour incubation at 37 C, while for the 5 kV/cm - 40

 s pulses, the membrane reseal after 30 min incubation. We can conclude that the pulse length is the main parameter that controls the resealing process of the electroporated membrane.

114

CAFFEINE ANALYSIS USING DIRECT INLET MASS

SPECTROMETRY WITH SELECTED ION MONITORING

N.Palibroda, Ileana Chirtoc, P.Vegh, A.Pamula

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5, Romania

Caffeine analysis is required for several purposes, as for instance in the quality assurance of food and beverages or as a test for hepatic function. The standard method for caffeine analysis is based on optical absorbency measurements performed at 276 nm after prior purification by liquid chromatography on two columns with acidic and alkaline properties. The method is not free of possible interferences.

A method for caffeine analysis having high specificity was developed, using selected ion monitoring mass spectrometry with direct inlet of the samples. In the absence of isotopically labelled caffeine, that would have been the best possible internal standard, theophylline was chosen as internal standard, due to its closely related chemical structure and properties.

Caffeine was extracted from aqueous solutions spiked with theophylline at a concentration of 40 µg/ml and extracted with a mixture of chloroform - isopropyl alcohol

19:1 vol/vol., by electromagnetic shaking for 90 seconds and centrifugation for three minutes.

Aliquots of 3 µl of the extract were introduced into the crucible of the direct inlet and the solvent was evaporated in an air stream. Finally the temperature of the sample was programmed in the ion source from room temperature to 250 o

C over 3 minutes, monitoring the intensities if the molecular ions m/z=194 for caffeine and m/z=180 for theophylline at a sampling rate of 120 kHz.

The linearity obtained in the concentration range 2.5 - 15 µg/ml shows a correlation coefficient r=0.965

Sensitivity corresponds, in the case of the smallest concentration, 2.5 µg/ml, to about

8 nanograms of caffeine introduced into the crucible for a single determination.

115

SOLITON EXCITATIONS IN THE QUASI-ONE-

DIMENSIONAL CONDUCTOR RB

2

PT(CN)

4

(FHF)

0.4

O. Pană, L.V. Giurgiu

1

, S. Knorr

2

and M. Mehring

2

1

National Institute for Research and Development of Isotopic and Molecular

2

Technologies, 3400 Cluj-Napoca 5, Romania

2 Physikalisches Institut, University

 t Stuttgart, 70550 Stuttgart, Germany

We study the soliton generation process in quasi-one-dimensional platinum

Rb

2

Pt(CN)

4

(FHF)

0.4

(RbCP(FHF) ) compound. Under the Peierls-transition temperature T

P

a periodic lattice distortion accompanied by a charge density wave (CDW) with commensurability N=5 condensates. In the particular case of RbCP(FHF), as a result of the 0.4 partial degree of oxidation, it remains 1.6 electrons per platinum position leading to a partially filled band. The CDW have a wave vector

q

0

= 0.4

/

d

and an associated wavelength

= 2

/

q

0

= 5

d

perfectly commensurate with the

Pt-Pt spacing

d

. Since in the RbCP(FHF) compound the CDW is perfectly commensurate with the Pt-

Pt distance, soliton-like excitations should not be present in this material.. Nevertheless, lattice dislocations, impurities, or chain-end effects produce centres, which locally distort the CDW. As a result, a soliton-antisoliton pair appears in order to restore the perfectly commensurate CDW on both sides of the depinning centre.

By using the one-electron Green's function method one can calculate the electronic energy spectrum in both commensurate and discommensurate (soliton) domains. The gap parameter

was considered as adjustable in order to obtain a total amount of

2/5

electronic states as removed from the valence band to form the localised intragap solitonic state between valence and conduction bands.

This was achieved (i) by calculating numerically the density of states, followed (ii) by its integration over the reduced zone in both commensurate and discommensurate domains. Figure 1. shows the resulting energy spectrum in commensurate domains. The missing states from the valence and conduction bands, in discommensurate domains with respect to the commensurate ones (as result from the soliton generation), are presented in Fig.2.

S , Q

S

= (2/5) e

0.90

(a)

(b)

1.0

0.0

0.85

0.5

-0.5

0.0

0.80

v. b.

c. b.

-0.5

-1.0

0.75

-1.0

0.0 0.2 0.4 0.6 0.8 1.0

k/q

0

0.0

0.1

k/q

0

0.2

0.70

Figure 1 (a) Energy spectrum in the reduced zone of 5d z

2

Pt electrons in RbCP(FHF) with commensurability N=5. b) Enhanced resolution to show the gap between valence and conduction bands.

-1.5

0.78

0.79

0.80

0.81

E/2t

0

0.82

0.83

0.84

0.85

Figure 2: Changes in the density of states in a discommensurate (soliton) region for RbCP(FHF). The localised solitonic state is placed inside the gap and is represented by the vertical bar.

116

SOLITON PICTURE AND EPR LINEWIDTH IN THE

QUASI-ONE-DIMENSIONAL CONDUCTOR RB

2

PT(CN)

4

(FHF)

0.4

O. Pană, L.V. Giurgiu

1

, S. Knorr

2

and M. Mehring

2

1

National Institute for Research and Development of Isotopic and Molecular

Technologies, 3400 Cluj-Napoca 5, Romania

2

2 Physikalisches Institut, Universität Stuttgart, 70550 Stuttgart, Germany

The existence of solitons (antisolitons) with unpaired spins may be responsible for the observed EPR resonance line in Rb

2

Pt(CN)

4

(FHF)

0.4

(RbCP(FHF)). In the abstract we present an analysis of EPR results in terms of a motionally narrowed hyperfine interaction of an unpaired spin soliton decollated over several platinum nuclei. From the two Pt stable isotopes, only

195

Pt has a nonvanishing nuclear spin

I=1/2

. The method is based on the calculation of the second moment of the absorption line M

2

in the presence of a single nuclear spin species with natural abundance

r

. In the special case where the magnetic field points into the

z

direction one finally arrives at

M

2

r

1

4

2

A zz

k

2

k

This formula holds whichever spin-density function is assumed. The second order momentum M

2

is related to

B, the full width at half height (FWHH) of the EPR line, by the equation

B

8 ln 2

M

2 for a Gaussian line shape. Note that motional narrowing changes the lineshape from Gaussian to Lorentzian.

300

200

E a

= 99.034 K

B a

= 8937.807 Gauss

E = 735.58 K

B

0

= 159.42 Gauss



0

= 1.7897 10 -4 Gauss -1

100

0

0 20 40

T [K]

60 80 100

.

Figure 2: Fit of the experimental FWHH linewidth

B in RbCP(FHF) B

c to motional narrowing and an activated relaxation The residual FWHH line- width (T=0) is found to be about 159.4G. All fit parameters are listed in frame.

The temperature dependence of the experimental X-band EPR linewidth for RbCP(FHF) could be fitted very well by considering two competitive processes: (i) an activated relaxation and (ii) motional narrowing due to the soliton excitations. The total linewidth can be calculated from the sum of the second moments of the above mentioned processes as shown in Fig. 1 for the

B

c

. Here

c

is the axis along the platinum chain. This approach leads to a residual linewidth in the absence of the metal-insulator transition of

B

0

= 159.4 G.

117

CONCENTRATION DEPENDENCE OF

(C - Br) BAND

SHAPE OF 2-BROMOPROPANE IN SOLVENT MIXTURES

Rodica Grecu

1

, I.Bratu

2

, O.Cozar

3

1

Institute of Chemistry Cluj-Napoca, Fintinele 30, Cluj-Napoca

2

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O. Box 700, 3400 Cluj-Napoca

3

”Babes-Bolyai” University, Faculty of Physics, Kogalniceanu 1, Cluj

Solvent dependent studies demonstrate the sensitivity of the line shift and width on the liquid environment. We paid attention to

(C-Br) vibrational mode of 2-bromopropane (the solute), observed at 537.4 cm

-1

in neat liquid. The results of a previous study confirmed that non-specific long-range dipolar interactions between the solute and solvents of different polarity are important.

Excepting aromatic hydrocarbons and chloroform, a linear shift of the band maximum upon the

Onsager’s function

f (

) = (

- 1) / (2

+ 1)

is observed. The effects of the individual solvents, CCl

4 and CH

3

CN, and their mixtures on infrared

(C-Br) band shape are analysed to obtain information on the short range interactions and their contribution to the homogeneous line broadening. The halfband width, FWHH of

(C-Br) solute band in CCl

4

decreases on dilution, see Fig.1. We calculated the number of particles that effectively perturb the reference vibrational mode and it is smaller than eight, a typical number of nearest neighbours in a liquid. Only the solvent molecules situated in the

11.0

10.5

10.0

9.5

9.0

8.5

2

2 Br-Propane / CCl

4

Fig. 1

3 c(M)

4 5

13.0

12.5

12.0

11.5

11.0

10.5

10.0

9.5

9.0

8.5

8.0

7.5

7.0

0.0

2Br-Propane/ {CCl

4

+ CH

3

CN}

Fig. 2

0.1 M

1 M

8.0

0 1 6 7

0.2

0.4

0.6

x p

0.8

1.0

1.2

neighbourhood of C-Br bond perturb this vibrational mode. An additional linewidth is observed when the solvent is a mixture of CCl

4

and CH

3

CN. The dependence of FWHH

vs.

x

P

(mole fraction of polar solvent), Fig.2, goes through a maximum at a value of

x

P

of about 1/2. An effect of “preferential solvation”, that is a local enrichment of the polar solvent component explain also why the frequency shift is not proportional to the bulk

x

P

mole fraction. The solute-solvent interactions in the first solvation shell, local polarity and concentration are factors that affect the

(C-Br) band shape. A homogeneous (fast modulated) mechanism and a Lorentzian lineshape are expected.

118

STUDY OF INTENSITY AND IONIZING RADIATION

TYPE INFLUENCE ON SOME PORPHYRINS WITH

APPLICATIONS IN CANCER THERAPY

R.M.Ion*, M.Grigorescu*, F.Scarlat**, A.V.Niculescu**,V.Niculescu**,

K.Gunaydin***

*Zecasin S.A., Photochemistry Dept.,Bucharest;

**Institute of Radiation Physics, Plasma and Lasers, Bucharest, Romania;

***Mustafa Kemal University , Chemistry Dept., Antakya,Turkey.

This paper deals with the experimental results about the modifying effects of ionising radiation (electron and photon beam) at different intensities (200-30.000R) and/or light on tetra-kis-p-sulfonato-phenyl-porphyrin(TSPP) in water solutions as a new and efficient sensitiser efficiently used in photodynamic therapy of cancer .

The spectral changes upon ionising irradiation of TSPP show the formation of phlorin-type

When these irradiated porphyrins solutions were exposed to light, J- and H-aggregated species were generated .The small intensity of ionising radiation stimulate H-aggregation.

Different proportions (experimentally determined) of singlet and triplet excited states are formed initially on ionising irradiation as compared with light irradiation of water-solutions of TSPP. In the case of firstly ionising irradiation, the subsequently light irradiation yields to the generation of triplet states, the proportions of initially ratio triplet: singlet excited states being normally around 3:1 , whereas with sensitiser TSPP firstly excited with light and after that with ionising radiation, the singlet excited state of TSPP will be the major species but at a generation rate more reduced than using ionising radiation excitation.

Another important difference between light and ionising irradiation the formation of excited states is independent of the light absorption of the solute and solvent. The singlet oxygen formation , so the photochemical efficiency in photodynamic therapy of cancer is enhanced if face-to-face configurations (H-aggregated forms) are formed. The porphyrin is efficiently incorporated in a monomeric form in granulocytes and leukocytes and in a J-aggregate fluorescent forms but only in granulocytes.

119

SPECTROSCOPIC STUDY OF SOME

SUPRAMOLECULAR AGGREGATES PORPHYRINS-

PHTHALOCYANINES AND THEIR IMPLICATIONS IN

PHOTOMEDICINE

R.M.Ion*, M.Grigorescu*, F.Scarlat**, A.V.Niculescu**,V.Niculescu**,

K.Gunaydin***

*Zecasin S.A., Photochemistry Dept.,Bucharest;

**Institute of Radiation Physics, Plasma and Lasers, Bucharest, Romania;

***Mustafa Kemal University , Chemistry Dept., Antakya,Turkey.

The relevance of porphyrins and htalocyanines in various chemical and biological systems is well known. These compounds have been successfully tested as photosensitises for photodynamic therapy, hey exerting their cytotoxic effects via triplet-sensitised singlet oxygen .By coupling oppositely charged subtituents phthalocyanines and porphyrins some supramolecular aggregates complexes could be obtained with a higher efficiency and stability. The effects of photons and electron beams and/or light on this supramolecullar assemblies are also studied. Spontaneous ion pairing from the chromophoric systems participating at the reaction occurs in electron beam -200 R-, in photon beam -800 R-, or in a electron/photon/light flux

In this paper, we report about the synthesis, spectral characterisation such heteroaggregate

(RhTPyP-ZnTSPP) and its applications on a cellular Sacharomices Cerevisiae culture cells.

Their implications into the photodynamic therapy are also evaluated.

120

OPTICAL AND CHARGE TRANSPORT STUDIES OF

SOLUBLE CONDUCTING POLYMERS

R.Turcu

1

, W.Graupner

2

, A.Bot

1

, M.Brie

3

, R.Grecu

3

, I.Bratu

1

, G.Feistritzer

2

,

1

National Institute for Research and Development for Isotopic and Molecular

Technologies, P.O.Box 700, 3400 Cluj-Napoca, Romania

2

Institut fur Festkorperphysik, Technische Universitat Graz, Petersgasse 16,

A-8010 Graz, Austria

3

Institute of Chemistry, 3400 Cluj-Napoca, Romania

Optical and electrical properties of soluble polypyrrole (PPY) and composites are presented. The polypyrrole has been chemically synthesised using large size dopant ions such as: dodecylbenzenesulfonate (DBS), dodecylsulfate (DS) and antraquinonesulfonate (AQ).

Thin polymer films were obtained from solutions in chloroform or m-cresol as solvents.

We focus on the effects of polymer-solvent and polymer-polymer intermolecular interactions on the properties of doped polypyrrole and composites. In order to study how the molecular interaction between the components affects the properties of the composite we mix different types of polymers: i) doped polypyrrole and an undoped highly fluorescent polymer

(methyl substituted ladder-type polyparaphenylene, m-LPPP); ii) doped polypyrrole and an electronically inert polymer (polymethylmethacrylate, PMMA). The contribution of the intermolecular interactions to the optical properties of PPY and composites has been investigated by UV-VIS transmission spectroscopy. The stronger interaction of PPY with the aromatic solvent molecules like m-cresol results in a better solubility than in chloroform. The bipolaronic absorption band for PPY(DBS) film cast from m-cresol solution is shifted to higher energies as compared to that for PPY(DBS) cast from chloroform solution. This effect is attributed to PPY-solvent interaction, which results in different chains conformation.

PPY(DBS) film cast from m-cresol solution contains shorter conjugated segments as compared to PPY(DBS) film cast from chloroform solution. By the combination of electrically conducting PPY with a non-conjugated polymer, PMMA we improved the mechanical properties of the films without major changes of PPY absorption spectrum in the visible range. Significant effects were obtained when we mix conjugated polymers having different electronic and optical properties: doped PPY and undoped, highly fluorescent m-

LPPP. The red shift of the absorption spectrum for m-LPPP/PMMA/PPY(DBS) related to that of m-LPPP is attributed to dipolar-dipolar interactions between PPY and m-LPPP chains.

In order to tune the polymer-polymer interaction we have also applied optical absorption spectroscopy under high pressures up to 3 kbar. Differences in the structural details of the polymers results in different behaviour under high pressures. Thus for a planar arrangement of the molecules, which we consider m-LPPP/PMMA/PPY(DBS) to be, the pressure will be more effective in increasing dipolar interactions responsible for the red shift of the spectrum.

For PPY(DBS) and PPY(DBS)/PMMA dopant anions and solvent molecules influence the magnitude of the interactions between the macromolecular segments.

The behaviour of the electrical conductivity for polypyrrole samples in the temperature range 90-330K is discussed within the framework of Mott’s variable range hopping conduction model.

121

SPECTROSCOPIC STUDY OF SOME

SUPRAMOLECULAR AGGREGATES PORPHYRINS-

PHTHALOCYANINES AND THEIR IMPLICATIONS IN

PHOTOMEDICINE

R.M.Ion*, M.Grigorescu*, F.Scarlat**, A.V.Niculescu**,V.Niculescu**,

K.Gunaydin***

*Zecasin S.A., Photochemistry Dept.,Bucharest;

**Institute of Radiation Physics, Plasma and Lasers, Bucharest, Romania;

***Mustafa Kemal University , Chemistry Dept., Antakya,Turkey.

The relevance of porphyrins and phtalocyanines in various chemical and biological systems is well known. These compounds have been successfully tested as photosensitises for photodynamic therapy, they exerting their cytotoxic effects via triplet-sensitised singlet oxygen. By coupling oppositely charged subtituents phthalocyanines and porphyrins some supramolecular aggregates complexes could be obtained with a higher efficiency and stability. The effects of photons and electron beams and/or light on this supramolecular assemblies are also studied. Spontaneous ion pairing from the chromophoric systems participating at the reaction occurs in electron beam -200 R-, in photon beam -800 R-, or in a electron/photon/light flux.

In this paper, we report about the synthesis, spectral characterisation such heteroaggregate

(RhTPyP-ZnTSPP) and its applications on a cellular Sacharomices Cerevisiae culture cells.

Their implications into the photodynamic therapy is also evaluated.

122

MASS SPECTRA INTERPRETATION FOR SOME

THIOPHOSPHORYLIC

P-ACETHYLAMINOBENZENESULFONAMIDES

Rodica Popescu1, I. Fenesan1, C.T.Supuran

2

, Monica Culea3, N. Palibroda3,

Z. Moldovan3,

*

Simona Nicoara4 and O. Cozar5

1Institute of Chemistry "Raluca Ripan", Cluj-Napoca,

2

Universita degli Studi,

Dipart. di Chimica, Florence, Italy, 3I.T.I.M., Cluj-Napoca, Romania, 4Techn.

Univ., Physics Depart., C. Daicoviciu str. 15, RO-3400 Cluj-Napoca, Romania

(

*

correspondence), 5Univ. "Babes-Bolyai", Faculty of Physics, Cluj-Napoca.

The present paper discusses the synthesis and the fragmentation pattern for: 2-(pacethylaminosulfonamido) 2-(thiono 5,5-dimethyl 1,3,2-dioxaphosphorinane) (1) and for the p-acethylaminosulfonylamides of the: O,O-diethylthiophosphoric acid (2); O,Odiphenylthiophosphoric acid (3); dimethylamino cyclohexylthiophosphoric acid (4) and diethylamino phenylthiophosphoric acid (5), respectively. Organophosphorus compounds exhibit biological activity in a large variety of features and are widely studied lately, by physical and physico-chemical methods, including the mass spectrometry technique. The substances 1-5, were newly synthesised and were found biologically active.

The aim of this work is to present the synthesis of the new compounds, to interpret the

E.I. mass spectra, to discuss the fragmentation pathways and to elucidate the fragment ions structures for the following newly synthesised thiophosphorylic p-acethylamino-benzenesulfonamido derivatives

:

S

R1 P

R2

NH SO2 C6H4 NH C

O

CH3

Compound:

R1

1

O

2 3 4 5

C2H5O C6H5O C6H11 C6H5

R2 O C2H5O C6H5O N(CH3)2 N(C2H5)2

A thionamidic-thiolimidic structure was assessed to the compounds

1-5,

according to their

IR and NMR spectra. Normal EI mass spectra at 70 eV, high resolution mass measurements and metastable ions detection were used to elucidate the fragmentation processes.

123

ELECTRON IMPACT MASS SPECTRA ANALYSIS

FOR SOME NEW P-

BENZENESULFONAMIDOTHIOPHOSPHORIC DERIVATIVES

Simona Nicoara a

, Monica Culea b

, N. Palibroda b

, Z. Moldovan b

, I. Fenesan c

,

Daiana Beldean d

and V. Znamirovschi d a

Technical University, Physics Department, C. Daicoviciu str., nr. 15, RO-3400

Cluj-Napoca, Romania, b

National Institute for Research and Development for

Isotopic and Molecular Technologies, Cluj-Napoca c

Institute of Chemistry,

Cluj-Napoca, d

University “Babes-Bolyai” Cluj-Napoca, Romania.

The work deals with the interpretation of the EI mass spectra and presents the proposed fragmentation pattern for the molecules of some organophosphorus derivatives, newly synthesised at the Institute of Chemistry “Raluca Ripan”. The compounds studied have the following structural formula::

S

X

1

P

X

2

Compound

X

1

X

2

R

C

C

2

2

1

H

H

NH

5

5

O

O

COOCH

SO

2

C

2

C

2

H

5

O

C

2

H

5

O

COOH

6

H

4

3

R

5,5(CH

3

)

2

C

3

H

4

O

2

COOCH

3

5,5(CH

3

4

)

2

C

3

COOH

3

1

. p-carboximethoxibenzenesulfonamide of the diethoxythiophosphonic acid

H

4

O

2

2

. p-carboxihidroxibenzenesulfonamide of the diethoxythiophosphonic acid

3

. p-carboximetoxibenzenesulfonamide of the dimethylciclohexylthiophosphonic acid

4

. p-carboxihidroxibenzenesulfonamide of the dimethylciclohexylthiophosphonic acid.

The normal mass spectra, accurate mass measurements of the fragment ions and metastable ions detection in both the HV and MIKE modes were used to characterise the fragmentation pathways of these compounds. They belong to a class of organic compounds, which have been proved biologically active as therapeutic agents, pesticides or as plant growth regulators, being extensively studied lately. Among other methods, the mass spectrometry technique appeared as a useful tool in their identification, detection and quantitative analysis.

The molecular ion peaks are missing or are very low due to the high degree of the molecules ramification. The typical SO

2

elimination was encountered as the initiating process in a consistent molecular fragmentation.

124

APPLICATIONS OF THE MICROWAVES POWER

TREATMENTS

E.Surducan, S.Filip, V.Surducan, Gabriela Nagy, Camelia Neamtu

National Institute for Research and Development for Isotopic and Molecular

Technologies - Cluj Napoca, POB.700, R-3400, Romania, e-mail: manu@l30.itim-cj.ro

Our purpose is to present microwaves power, direct and indirect treatments and the related equipment’s. Also we present the base theory of the microwave power absorption in materials.

The terms “ direct” and “indirect” refers to the character of the microwave absorption in the treated material. In our case, the direct microwave power treatment are chemical reactions activated in microwave field by direct absorption of the microwave power. The yield and time of reaction are correlated with the classical one. The microwave power equipment, the microwaves power field distributions in the reaction chamber, the temperature measurements and the solution for microwave adapting technique are also presented.

The indirect microwaves treatments are plasma induced reactions. Reactive plasma discharge are widely used to process materials. In this case, the plasma is confined in the maximum microwave power density distributions of one microwave cavity. The ions are transported to the chemical reaction locations by flow method. The microwave plasma generator, the microwave power field distribution and some applications are presented.

As a conclusion, the advantage and the disadvantage of the microwave power treatments are analysed.

125

MICROWAVE IMPEDANCE NETWORK ANALYSER

V.Surducan, E.Surducan

National Institute for Research and Development for Isotopic and Molecular

Technologies - Cluj-Napoca, POB.700, R-3400, Romania, email : manu@l30.itim-cj.ro

In the microwave absorption applications, the probe is a microwave impedance. In the microwaves treatments applications it is enough to know the microwave impedance modification with temperature, rather than the dielectric properties modifications.

In this paper, we present one “home-brew” impedance network analyser in the microwave range. The application is based on the analog-digital-analog PC interface. It is a six -port microwave bridge with a lock-in detection . The experimental set-up is presented in figure 1

SIX PORT BRIDGE

PROBE

MICROWAVE

GENERATOR

PIN

Modulator

Microwave detection

Step by step Driver and Motor

LPT

ANALOG-DIGITAL-ANALOG

INTERFACE

PC

“+”

SOFTWARE

Figure 1

As a part of the experimental set-up, the lock-in and the step by step driver software are presented. The theoretical connection between microwave impedance and the dielectric and magnetic properties of the sample are also presented.

The conclusions presents the impedance measurements and the limitations of our experimental devices.

126

COMPUTER CALCULATION OF INFRARED

MULTIPLE PHOTON ABSORPTION OF CF

2

DCl

A. Bende, V. Tosa, and V. Cosma

National Institute for Research and Development of Isotopic and Molecular

Technologies, P.O. Box 700 3400 Cluj-Napoca, 5, Romania

In the last few years, an increasing interest has been developed for CF

2

HCl, an asymmetric top which has been studied as a prospective molecule for laser isotope (

13

C and

D) separation by infrared multiple-photon dissociation. Although the multiple-photon dissociation process is, in most cases, assisted by collisions, the absorption of the first few photons is coherent. In addition in the two-colour laser dissociation the first laser of weak fluency but properly tuned, promotes the molecules on the first discrete vibrational levels, while the second laser, of higher fluency and red-shifted with respect to the first laser, leads the molecules to quasicontinuum and then dissociates the vibrationally excited molecules.

Modelling the part of the process, namely the absorption of the first few photons could yield valuable information about the laser-molecule interaction, and about the optimisation of the isotopic selective process.

We describe in this paper a model for the infrared multiple photon absorption

(IRMPA) developed by us for an asymmetric top, both for a

b

-type band and for an

a/c

type band. We used the molecular constants, when available in the literature. In particular, for

CF

2

HCl and CF

2

DCl we present the method used and the results obtained in calculating the induced dipole moments for the

3

and

8

normal modes of the protonated and deuterated molecule. They were not measured or estimated previously in the literature

Values for the population of the excited vibrational levels and their dependence on the laser frequency and on the laser fluency are also presented. The multiphoton absorption spectra are obtained for both

3

and

8

normal modes because these modes are situated in the range of wavenumbers, which are partially covered, by the emission range of the CO

2

laser.

The obtained results are discussed in connection with the experimental data obtained recently.

127

INFRARED MULTIPHOTON ABSORPTION SPECTRA

OF GAS PHASE CF

2

DCl MOLECULES

Valer TOSA, Valer ALMASAN, Magna SANTOS a

, and Luis DIAZ a

National Institute for Isotopic and Molecular Technology,

P.O.Box 700, Cluj-Napoca, ROMANIA a

Instituto de Estructura de la Materia, CSIC, Serrano 121, 280 06 Madrid,

SPAIN

The present work was undertaken to explore the feasibility of using the CF

2

DCl dissociation in two-wavelengths laser fields for the separation of hydrogen isotopes. In this method [1] the first laser, slightly red shifted with respect to the excited normal mode, promotes the molecules on the first few vibrational levels, while the second laser, of higher fluency and red-shifted with respect to the first laser, dissociates the vibrationally excited molecules. To optimise the dissociation yield one needs to study the dependence of the multiphoton absorption cross section on the laser parameters like pulse duration, fluency and wavelength.

The CF

2

DCl molecule was prepared at 425-500 C by the reaction between CF

2

HCl

(which decomposes into CF

2

and HCl) and a large excess of DCl in a quartz bulb. The isotopic purity of the reaction product, as measured from the mass spectrum is found to be better than 85%.

The CF

2

DCl normal modes of interest are

8

= 969 cm

-1

and

3

= 1013 cm

-1

, and are well separated from all other modes of CF

2

HCl. The corresponding bands, obtained at room temperature and pressures ranging from 1 to 30 Torr, partially overlap and give an absorption profile centred around 1000 cm

-1

. However, the

b

-type (with only PR branches) of the

8 band, as well as the PQR

a/c

type of the

3

band can be easily seen.

The multiphoton absorption measurements were performed with a Lumonics 103

TEA laser operated with a low N

2

laser mixture so that the laser pulses, as seen by a photon drag detector, show 100 nsec FWHM with no tail. A 35 cm long cell fitted with NaCl windows was used throughout of the experiments. Pressures varied from 1 to 10 Torr, and laser fluences from 0.1 to 2 J/cm

2

. The laser was tuned between 975 and 988 cm

-1

, that is from 10R(20) to 10R(38) line of the CO

2

laser.

The multiphoton absorption profile, obtained at 10 Torr of gas in the above region shows, as in the case of CF

2

HCl [2], sharp absorption profiles. A well defined maximum around 987 cm

-1

might be assigned as due to the multiphoton resonances in the

3

ladder .

Indeed, the anharmonicity of this normal mode is around 3.3 cm

-1 so that resonances of 5 to 7 photons are quite possible. Lower order resonances are to be expected for higher wavenumbers but this spectral region is unfortunately unavailable for the CO

2

laser. A second maximum of smaller intensity is observed around 975 cm

-1

and is probably due to the

R-

8

ladder.

128

DAQ SYSTEM FOR REMOTE MONITORING AND

CONTROL

OF A LABORATORY CHEMICAL PLANT

Zoltan Nagy and Serban Agachi

"Babeş-Bolyai" University of Cluj-Napoca,

Faculty of Chemistry and Chemical Engineering,

Arany Janos 11, 3400 Cluj-Napoca, Romania;

Tel. 0040-64-193833 Fax., 0040-64-190818,

E-mail: znagy@chem.ubbcluj.ro, sagachi@chem.ubbcluj.ro

Practical experience is a very important part of engineering education, but it demands great resources. Designing and constructing state-of-the-art experiments can take time, money and energy. Sharing experiments locally and remotely allows unique laboratory equipment to be utilised more fully, brings down the experiment cost per student, and makes more experiments available to student. The application described below presents a method of usage and exploitation of the facilities given by the computer and the Internet. Our goal was to implement the

"remote laboratory"

paradigm in our chemical process control laboratory.

The software of the application was written in LabVIEW (National Instruments,

SUA) and allows the authorised users to access a laboratory chemical plant in order to execute experiments remotely with the equipment. The scopes of the experiments are, to study the dynamic behaviour of a cascade of three pressurised vessels, as well as the way in which the pressure in the system can be controlled either manually or using PID controller.

Students also can study different tuning algorithms for the PID controller. The application provides a detailed description of the equipment and the theoretical background of PID control and tuning algorithms. The software provides an audio and video transmission from the remote equipment, to create the sense of being present ("telepresence") at the information source. The main window of the application is presented below.

129

FLUCTUATIONS OF THE HUMAN ERYTHROCYTE

V.V.Morariu

National Institute for Research & Development of Isotopic and Molecular

Technologies, P.O. Box 700, R 3400, Cluj-Napoca, Romania

Purpose:

This investigation aimed to analyse the fluctuations of some geometrical parameters of the human erythrocyte: the great diameter D, the small diameter d, and the area. It has been known for a long time that investigation of the erythrocytes by optical microscopy may easily reveal the "flickering" phenomenon, which is due to the membrane undulations. Undulations are sensitive to the membrane elasticity, which in turn is sensitive to many physical, chemical and pathological influences. The main purpose of our work was a methodological one: we attempted to analyse the flickering phenomenon by serial fast recording of a cell image which was subsequently analysed in respect to plan geometrical parameters. This attempt wants to be an alternative for the present method, which is based on the cell thickness measurements, by using an elaborate microscopic technique.

Materials and Methods:

Fresh human blood was diluted in the autologous plasma and placed between two glass plates spaced by a 7 microns nylon fibre. Successive images at 0.5 seconds time interval have been taken with a camera attached to a microscope operating in the phase contrast mode. The cell images were subsequently analysed by a using a soft for shape analysis. The time series have been further analysed as such and by performing FFT. Three kinds of samples have been analysed: fresh-floating cells, aged floating cells and trapped cells into the fibrin clot.

Results:

Examination of the time series revealed a multitude of fluctuations having clearly a distribution of frequencies. It appeared that a simple visual examination can make a distinction of the following categories: a) fast fluctuations possibly associated to the flickering phenomenon, b) slow fluctuations probably associated to the elongation or shortening of the cells and, c) partial rotation of the cells, i.e. rotation of the cell either around the smaller or the longer diameter. If the data are set free of the b) and c) fluctuations and are subsequently subjected to FFT, 1/f a

type of spectra results. The noise index appeared to be sensitive whether the cell is aged or mechanically trapped into the fibrin clot. The spontaneous elongation of the cell seems to have been for the first time to be reported in this work. The time series yields the rate of this phenomenon, which obviously is related to the membrane elasticity.

Conclusions:

The fluctuations of the geometrical plan parameters of the human erythrocyte revealed three types of phenomena: a) flickering, b) cell elongation and c) partial cell rotation. These results open the possibility to profitably use the geometrical parameters to investigate cell fluctuations. In addition the present work brings for the first time evidence for the slow spontaneous deformation and motion of the cells.

130

AUTHORS

ISOTOPIC PROCESSES

M. Abrudean

Ariadna Alexandrescu Research Institute for Soil Science and Agrochemistry, Bucharest

V. Almasan National Institute for Research and Development of Isotopic and

Molecular Technologies; O.P. 700, 3400, Cluj Napoca

P. Ardelean National Institute for Research and Development of Isotopic and

Molecular Technologies,

3400 Cluj-Napoca 5, P.O.BOX 700, Romania.

D. Axente

National Institute for Research and Development of Isotopic and

Molecular Technologies, 3400 Cluj-Napoca 5, P.O.BOX 700,

Romania.

Gh. Baciu

National Institute for Research and Development of Isotopic and

Molecular Technologies, 3400 Cluj-Napoca 5,

P.O.BOX 700, Romania.

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5,

A. Baldea

Catalina Barna

Judith Bartalis

H. Bendea

A. R. Biris

I. Calciu

I. Chereji

Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies, 3400 Cluj-Napoca 5, P.O.BOX 700,

Romania.

NIPNE Bucharest – Magurele

National Institute for Research and Development of Isotopic and

Molecular Technologies; P.O. 700, 3400, Cluj Napoca

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5,

Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5,

Romania

Research Institute for Soil Science and Agrochemistry, Bucharest

Diana Chiper

Maria Chiriac

C-tin Ciortea

Nicoleta Cojocaru

National Institute for Research and Development for Isotopic and

Molecular Technologies, P.O.Box 700, 3400 Cluj-Napoca 5,

Romania

National Institute for Physics and Nuclear

Engineering “Horia Hulubei”, CPR Department,

PO Box MG-6, Bucharest-Magurele, R-76900

National Institute for Research and Development of Isotopic and

Molecular Technologies, 3400 Cluj-Napoca 5, P.O.BOX 700,

Romania.

”Horia Hulubei” National Institute for Nuclear

Research and Engineering, P. O. Box MG-6,

Bucharest-Magurele, Romania

National Research Institute of Cryogenics and

Isotopic Technologies P.O. Box 10, Rm.Valcea, Code 1000,

ROMANIA Phone: 004 050/733890,

Fax: 005 050/732746

131

I. Coldea

C. Cosma

V. Cosma

O. Cozar

Gh. Cretu

I. Cristescu

Cornelia Croitoru

M. Culcer

C. Cuna

Elena David

F. Davidescu

C Deleanu

I Deleanu

L.C. Dinescu

S. Dronca

O.G. Duliu

Dana Dumitriu

Elisabeta Dumitru

M Dumitru

B. Erdelyi

C. Fatu

Lucia Feurdean

National Institute for Research and Development ofIsotopic and

Molecular Technologies,

P.O.BOX 700, 3400 Cluj-Napoca 5, Romania

University “Babes-Bolyai” Cluj-Napoca,3400, Ro

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5,

Romania

University “Babes-Bolyai” Cluj-Napoca, 3400, Ro

Army Center for Medical Research Bucharest

National Research Institute for Cryogenics and

Isotopic Technologies, C.P. 10, 1000 Rm. Vâlcea, Romania

National Institute of Research-Development for

Cryogenic and Isotopic Technologies,

ICSI Rm. Vâlcea

National Research Institute for Cryogenics and

Isotopic Technologies, C.P. 10, 1000 Rm. Vâlcea, Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5,

Romania

National Research Institute of Cryogenics & Isotopic Technologies

P.O.Box 10,Rm.Valcea, Code 1000, ROMANIA Tel.: +40 50

732744;

Fax: +40 50 732746

National Institute of Meteorology and Hydrology, Sos. Bucuresti-

Ploiesti 97,

71552 Bucharest

"C. D. Nenitzescu" Institute for Organic Chemistry, Bucharest

Organic Chemistry Institute “C D Nenitescu”

Bucharest

Institute of Physics and Nuclear Engineering “Horia Hulubei”,

Mãgurele, P.O. Box MG - 06, RO - 76900, Bucharest, România

National Institute for Research and Development of Isotopic and

Molecular Technologies,

3400 Cluj-Napoca 5, P.O.BOX 700, Romania.

University of Bucharest, Mãgurele,

P.O. Box MG - 11, RO - 76900, Bucharest

”Horia Hulubei” National Institute for Nuclear

Research and Engineering, P. O. Box MG-6,

Bucharest-Magurele, Romania

Research Institute for Soil Science and Agrochemistry, Bucharest

Research Institute for Soil Science and Agrochemistry, Bucharest

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5,

Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies, 3400 Cluj-Napoca 5, P.O.BOX 700,

Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies,

3400 Cluj-Napoca 5, P.O.BOX 700, Romania.

132

V. Feurdean

C. Floare

Y. Fujii

Eugenia Gament

Doina Gazdaru

M. Gligan

N. Gligan

Andreea Gluhoi

I. Hodor

R. Horga

I. Ilies

Mariana Iliescu

D. Ioanoviciu

M Ionica

M. Kaucsar

St. Kovacs

S. Kreibik

Mihaela Lazar

M. Leuca

National Institute for Research and Development of Isotopic and

Molecular Technologies,

3400 Cluj-Napoca 5, P.O.BOX 700, Romania.

National Institute for Research and Development of Isotopic and

Molecular Technologies, 3400 Cluj-Napoca 5, P.O.BOX 700,

Romania

Tokyo Institute of Technology, Research Lab for Nuclear Reactors Ookayama, Meguroku,

Tokyo 152, Japan

Research Institute for Soil Science and Agrochemistry, Bucharest

Biophysics Department, Faculty of Physics, Bucharest University,

Bucharest, Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700,3400 Cluj-Napoca 5,

Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5,

Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies; P.O. 700, 3400, Cluj Napoca

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5,

Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies, 3400 Cluj-Napoca 5, P.O.BOX 700,

Romania.

National Institute for Research and Development of Isotopic and

Molecular Technologies, 3400 Cluj-Napoca 5, P.O.BOX 700,

Romania

National Research Institute for Cryogenics and

Isotopic Technologies, C.P. 10, 1000 Rm. Vâlcea, Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5,

Romania

Army Center for Medical Research Bucharest

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5,

Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5,

Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5,

Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies; O.P. 700, 3400, Cluj Napoca

National Institute for Research and Development of Isotopic and

Molecular Technologies, 3400 Cluj-Napoca 5, P.O.BOX 700,

Romania

133

D. Lupu

G. Maniu

P. Marginean

Elena Mastan

Gh. Mihailescu

N.G. Mihãilescu

D.M. Motelica

C. Neamtu

C.A. Nicolae

M. Nomura

N. Palibroda

A. Pamula

M. Peculea

Doina Plaxienco

I. Pop

G. Popeneciu

St. Popescu

Cristian Postolache

V. Preoteasa

Ioana Prodan

N.. Prodan

Stela Pruneanu

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5,

Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5,

Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies; P.O. 700, 3400, Cluj Napoca

Informatic High School “Tiberiu Popoviciu”,

3400 Cluj-Napoca,Ro

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5,

Romania

Geological Survey of Romania, 1,

Caransebes str. RO - 78344, Bucharest

Research Institute for Soil Science and Agrochemistry, Bucharest

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5,

Romania

National Research Institute of Cryogenics and Isotopic Technologies

P.O.Box 10, Rm.Valcea, Code 1000, ROMANIA Phone: 004 050 /

733890, Fax: 004 050 / 732746

Tokyo Institute of Technology, Research Lab for Nuclear Reactors Ookayama, Meguroku,

Tokyo 152, Japan

National Institute for Research and Development of Isotopic and

Molecular Technologies, 3400 Cluj-Napoca 5, P.O.BOX 700,

Romania.

National Institute for Research and Development of Isotopic and

Molecular Technologies, 3400 Cluj-Napoca 5, P.O.BOX 700,

Romania

Academia Româna, Bucuresti

Research Institute for Soil Science and Agrochemistry, Bucharest

Technical University, 3400 Cluj-Napoca, Ro

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5,

Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5,

Romania

NIPNE Bucharest – Magurele

Babes Institute, Molecular Genetics Department,

Independentei 99-101, Bucharest 76201;

V.

Agricultural Research Station, Teleorman

Agricultural Research Station, Teleorman

Spl

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5,

Romania

134

A. Rãdoi

Daniela Radu

Liliana Radu

Irina Radulescu

Carmen M Retevoi

D. Ristoiu

Dana Rusea

Maria Sahagia

L. Sarkozy

Irina Saros

Corina Simion

Claudia Sisu

V. Stanciu

Doina Stefanescu

I. Stefanescu

D. Steflea

Daniela Stoenescu

Z. Szilagyi

C. Teaca

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700,3400 Cluj-Napoca 5,

Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700,3400 Cluj-Napoca 5,

Romania

Molecular Genetics Department,

Independentei 99-101, Bucharest 76201

V. Babes Institute, Spl

Spl Molecular Genetics Department,

Independentei 99-101, Bucharest 76201

V. Babes Institute,

National Research Institute for Cryogenics and

Isotopic Technologies, C.P. 10, 1000 Rm. Vâlcea, Romania

University “Babes-Bolyai” Cluj-Napoca, 3400, Ro

Institute of Public Health Bucharest

NIPNE Bucharest – Magurele

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5,

Romania

National Institute of Research-Development for

Cryogenic and Isotopic Technologies,

ICSI Rm. Vâlcea

NIPNE Bucharest – Magurele

National Research Institute of Cryogenics and Isotopic Technologies

P.O.Box 10, Rm.Valcea, Code 1000, ROMANIA Phone: 004 050 /

733890, Fax: 004 050 / 732746

National Research Institute of Cryogenics and

Isotopic Technologies P.O.Box 10, Rm.Valcea, Code 1000,

ROMANIA Phone: 004 050 / 733890, Fax: 004 050 / 732746

National Research Institute of Cryogenics and

Isotopic Technologies P.O. Box 10, Rm.Valcea, Code 1000,

ROMANIA Phone: 004 050/733890,

Fax: 005 050/732746

Institute of Cryogenics and Isotope Separation,

P.O.Box 10, 1000-Rm.Valcea (Romania), e-mail: icsi@ns-icsi.icsi.ro

Institute of Cryogenics and Isotope Separation,

P.O.Box 10, 1000-Rm.Valcea (Romania), e-mail: icsi@ns-icsi.icsi.ro

National Research Institute of Cryogenics and

Isotopic Technologies P.O. Box 10, Rm.Valcea, Code 1000,

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”Horia Hulubei” National Institute for Nuclear

Research and Engineering, P. O. Box MG-6,

Bucharest-Magurele, Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies, 3400 Cluj-Napoca 5, P.O.BOX 700,

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135

A. Tenu

Gh. Titescu

I. Toma

D. Ursu

M. Vermesan

National Institute of Meteorology and Hydrology, Sos. Bucuresti-

Ploiesti 97,

71552 Bucharest

National Institute of Research-Development for

Cryogenic and Isotopic Technologies,

ICSI Rm. Vâlcea

National Institute for Research and Development ofIsotopic and

Molecular Technologies,

P.O.BOX 70, 3400 Cluj-Napoca 5, Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies, 3400 Cluj-Napoca 5, P.O.BOX 700,

Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5,

D. Vonica

Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O.BOX 700, 3400 Cluj-Napoca 5,

Romania

Nicoleta Vrânceanu Research Institute for Soil Science and Agrochemistry, Bucharest

V. Znamirovschi University “Babes-Bolyai” Cluj-Napoca, 3400, Ro

136

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N. Aldea

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M. Apetri

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Craita Balan

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Daiana Beldean

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"Babes-Bolyai" University of Cluj-Napoca, Faculty of Chemistry and

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University of Oradea, Dept. of Science, 3700 Oradea, Romania

National Institute for Research and Development of Isotopic and

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Instituto de Investigaciones Quimicas y Ambientales de Barcelona, c/J. Girona 18-26, 08034 Barcelona, Spain

Université de Reims-Champagne-Ardennes:

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S.C. Natex s.r.l. Cluj-Napoca, Romania

National Institute for Laser, Plasma and Radiation Physics,

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“Babes-Bolyai” University, Faculty of Physics, Kogalniceanu 1, Cluj-

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Tech.Univ.Dep.Automatization and Computers, 3400 Cluj - Napoca

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"Babes-Bolyai" Univ., Dept. of Physics, 3400 Cluj Napoca, Romania

Hyperion University, 14 Culmea Veche St., Bucharest, Romania

National Institute for Research & Development of Isotopic and

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Instituto de Investigaciones Quimicas y Ambientales de Barcelona, c/J. Girona 18-26, 08034 Barcelona, Spain

University "Babes-Bolyai" Cluj-Napoca, Romania.

University of Agriculture Sciences and Veterinary Medicine of Cluj-

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National Institute for Research and Development of Isotopic and

Molecular Technologies, 3400 Cluj-Napoca 5, Romania

Wageningen Agricultural University, Dept. of Agric. Engng and

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Department of Physical Chemistry, Technical University of Budapest,

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National Institute for Research and Development of Isotopic and

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National Institute for Research & Development of Isotopic and

Molecular Technologies, P.O.Box 700, 3400 Cluj-Napoca 5,

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Institute of Isotopic and Molecular Technology, 65-103 Donath

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National Institute for Research and Development of Isotopic and

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National Institute for Research & Development of Isotopic and

Molecular Technologies,

PO Box 700, Cluj - Napoca Phone: 064 405300, Fax: 064 191906, Email: ibratu@l30.itim-cj.ro

Institute of Chemistry, 3400 Cluj-Napoca, Romania

Institute of Atomic Physics, Magurele Bucharest POBox MG-36, R-

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Institute of Atomic Physics, Magurele Bucharest POBox MG-36, R-

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Institute of Physics and Nuclear Engineering, Department ofTheoretical Physics, Bucharest

University of Oradea, Dept. of Physics, Oradea, Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies, 3400 Cluj-Napoca 5, Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O. Box 700, 3400 Cluj 5, Romania

"Babes -Bolyai" University, Faculty of Physics, RO-3400 Cluj,

Romania

Babes-Bolyai University, Physics Department, Kogalniceanu 1, RO-

3400 Cluj-Napoca, Romania.

Clinical Laboratory of Bio-Chemistry, Motilor Street, No 19, Cluj-

Napoca, Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O. Box 700, 3400 Cluj 5, Romania

S.C. Natex s.r.l. Cluj-Napoca, Romania

"Raluca Ripan" Institute of Chemistry, 30 Fântânele Street, RO-3400

Cluj-Napoca, P.O. Box 702

Technical University, 3400 Cluj-Napoca, Romania

"Al.I.Cuza"University, Faculty of Physics, Bd. Copou nr.11, 6600

Iasi

"Babes-Bolyai" Univ., Dept. of Physics, 3400 Cluj Napoca, Romania

Technical University of Cluj-Napoca, Romania

S.C."Natex"S.R.L., Cluj-Napoca

National Institute for Research and Development of Isotopic and

Molecular Technologies,

3400 Cluj-Napoca, Romania

National Institute for Laser, Plasma and Radiation Physics,

LaserDept., P.O.Box MG 36, R-76900, Bucharest, Romania

Institute of Isotopic and Molecular Technology, Cluj-Napoca 5, PO

Box 700, 3400 Cluj, Romania

"Babes -Bolyai" University, Faculty of Physics, RO-3400 Cluj,

Romania

Faculty of Physics, "Babes-Bolyai" University, 1 M.Kogalniceanu

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Xenia Filip

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Mihaela Gorgoi

R. Gradinaru

W Graupner

D. Grecu

Rodica Grecu

J. Greve

M. Grigorescu

K. Gunaydin

"Babes-Bolyai" Univ., Dept. of Physics, 3400 Cluj Napoca, Romania

Depto. de CC y TT Físico Quimicas, UNED, E-28040 Madrid, Spania

Instituto de Estructura de la Materia, CSIC, Serrano 121, 280 06

Madrid, SPAIN

Instituto de Estructura de la Materia.

C.S.I.C.Serrano, 121. 28006-Madrid. Spain

Al.I.Cuza University, Faculty of Physics, Iasi, Bd. Copou, nr.11,

6600 Iasi, Romania, E-mail ddorohoi@uaic.ro

"Al.I.Cuza" University, Faculty of Physics, Iasi, Bd. Copou, nr.11,

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National Institute for Research & Development of Isotopic and

Molecular Technologies, Cluj-Napoca

National Institute for Research and Development of Isotopic and

Molecular Technologies,

3400 Cluj-Napoca, Romania

National Institute for Research & Development of Isotopic and

Molecular Technologies,

PO Box 700, Cluj - Napoca

Institut fur Festkorperphysik, Technische Universitat Graz,

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Institute of Chemistry "Raluca Ripan", Cluj-Napoca

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Cluj-Napoca, P.O. Box 702

National Institute for Research and Development of Isotopic and

Molecular Technologies, 3400 Cluj-Napoca 5, Romania, email: manu@l30.itim-cj.ro

University of Oradea, Dept. of Physics, Oradea, Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O. Box 700, 3400 Cluj 5, Romania

"Al.I.Cuza"University, Faculty of Physics, Bd. Copou nr.11, 6600

Iasi

"Babes -Bolyai" University, Faculty of Physics, RO-3400 Cluj,

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Babes-Bolyai University, Physics Department

Universitatea "Babes-Bolyai", Cluj-Napoca

National Institute for Research and Development of Isotopic and

Molecular Technologies, 3400 Cluj-Napoca 5, Romania

Babes-Bolyai University, Physics Department

“Al.I.Cuza” University, Faculty of Chemistry, Iasi, Bd. Copou, nr.11,

6600 Iasi, Romania

Institut fur Festkorperphysik, Technische Universitat Graz,

Petersgasse 16, A-8010 Graz, Austria

Institute of Physics and Nuclear Engineering, Department ofTheoretical Physics, Bucharest

Institute of Chemistry Cluj-Napoca, Fintinele 30, Cluj-Napoca

Department of Applied Physics, University of Twente, P.O. Box 217,

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Zecasin S.A., Photochemistry Dept.,Bucharest;

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139

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Romanian Academy

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3 USTL Lille, LASIR, 59655 Villeneuve d'Ascq, France

Depto. de CC y TT Físico Quimicas, UNED, E-28040 Madrid, Spania

Babes-Bolyai University, Physics Department, Kogalniceanu 1, RO-

3400 Cluj-Napoca, Romania.

National Institute for Research & Development of Isotopic and

Molecular Technologies, P.O.Box 700, 3400 Cluj-Napoca 5,

Romania

Department of Physical Chemistry, Eotvos Lorand University,

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Zecasin S.A., Photochemistry Dept.,Bucharest; Romania

U.M.F. "I.Hatieganu", Cluj-Napoca, Dept.of Biochemistry

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Romania

West University of Timisoara, Faculty of Physics, 1900-Timisoara,

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University of Oradea, Dept. Of Physics, Oradea, Romania

Institut für Physikalische Chemie Universitãt Würzburg, Am

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Physikalisches Institut, Universität Stuttgart, 70550 Stuttgart,

Germany

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National Institute for Laser, Plasma and Radiation Physics,

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Babes-Bolyai University, Physics Department

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"Babes -Bolyai" University, Faculty of Chemistry, RO-3400 Cluj,

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National Institute for Research & Development of Isotopic and

Molecular Technologies, P.O.Box 700, 3400 Cluj-Napoca 5,

Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies,

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National Institute for Research & Development of Isotopic and

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G. J. Puppels

Biljana Radojevic

Tania Ristoiu

L. Rubio

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National Institute for Research and Development of Isotopic and

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Box 700, 3400 Cluj, Romania

"Babes-Bolyai" University of Cluj-Napoca, Faculty of Chemistry and

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National Institute for Research and Development of Isotopic and

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National Institute for Research and Development of Isotopic and

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“Al.I.Cuza” University, Faculty of Chemistry, Iasi, Bd. Copou, nr.11,

6600 Iasi, Romania

Institute of Radiation Physics, Plasma and Lasers, Bucharest,

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National Institute for Research and Development of Isotopic and

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Instituto de Estructura de la Materia.

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Rodica M Semeniuc

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Viorica Simon

G. Singurel

Undina Stanescu

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G.D. Stoicescu

A. Stratan

C.T Supuran

V. Surducan

E. Surducan,

Liu Tao

Hu Tiandou

C. V. Tiusan

Lavinia Tomole

J.A. Torresano

V. Tosa

I. Turcu

R. Turcu

Nicoleta Vedeanu

P. Vegh

Instituto de Estructura de la Materia.

C.S.I.C.Serrano, 121. 28006-Madrid. Spain

Institute of Radiation Physics, Plasma and Lasers, Bucharest,

Romania

Department of Applied Physics, University of Twente, P.O. Box 217,

7500 AE Enschede, The Netherlands

"BABES-BOLYAI" University, Chemistry Department;

"Babes-Bolyai" Univ., Dept. of Chemistry, 3400 Cluj-Napoca,

Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies, Cluj-Napoca, Romania

“Al.I.Cuza” University, Faculty of Chemistry, Iasi, Bd. Copou, nr.11,

6600 Iasi, Romania

Babes-Bolyai University, Physics Department

“Babes-Bolyai” University, Faculty of Physics, Kogalniceanu 1, Cluj-

Napoca, Romania

"Al.I.Cuza"University, Faculty of Physics, Bd. Copou nr.11, 6600

Iasi

Institute of Isotopic and Molecular Technology, Cluj-Napoca 5, PO

Box 700, 3400 Cluj, Romania

National Institute for Laser, Plasma and Radiation Physics,

LaserDept., P.O.Box MG 36, R-76900, Bucharest, Romania

Lucian Blaga University of Sibiu, Romania

National Institute for Laser, Plasma and Radiation Physics,

LaserDept., P.O.Box MG 36, R-76900, Bucharest, Romania

Universita degli Studi, Dipart. di Chimica, Florence, Italy

Institute of Isotopic and Molecular Technology, Cluj-Napoca 5, PO

Box 700, 3400 Cluj, Romania

Institute of Isotopic and Molecular Technology, Cluj-Napoca 5, PO

Box 700, 3400 Cluj, Romania

Beijing Synchrotron Radiation Facilities of Beijing Electron Positron

Collider National Laboratory, People’s Republic of China

Beijing Synchrotron Radiation Facilities of Beijing Electron Positron

Collider National Laboratory, People’s Republic of China

National Institute for Research and Development of Isotopic and

Molecular Technologies, 3400 Cluj-Napoca 5, Romania

Babes-Bolyai University, Faculty of Physics, 3400 Cluj-Napoca,

Romania

Instituto de Estructura de la Materia.

C.S.I.C.Serrano, 121. 28006-Madrid. Spain

National Institute for Research and Development of Isotopic and

Molecular Technologies, 3400 Cluj-Napoca 5, Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O. Box 700, 3400 Cluj 5, Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies, 3400 Cluj-Napoca 5, Romania

"Babes-Bolyai" Univ., Dept. of Physics, 3400 Cluj Napoca, Romania

National Institute for Research and Development of Isotopic and

Molecular Technologies,

3400 Cluj-Napoca, Romania

142

E. Vinteler

Anca Visinescu

E. Vogel

Violeta Vrabie

Zhongua Wu

Xie Yaning

V. Zaharia

Dai Zhen Ya

National Institute for Research and Development of Isotopic and

Molecular Technologies, P.O. Box 700, 3400 Cluj 5, Romania

Institute of Physics and Nuclear Engineering, Department ofTheoretical Physics, Bucharest

Institut für Physikalische Chemie Universitãt Würzburg, Am

Hubland, D 970974, Würzburg, Germany

Grupul Scolar de Gospodarirea Apelor si Prestari Servicii, Craiova,

Str. Brestei, Nr. 87

Beijing Synchrotron Radiation Facilities of Beijing Electron Positron

Collider National Laboratory, People’s Republic of China

Beijing Synchrotron Radiation Facilities of Beijing Electron Positron

Collider National Laboratory, People’s Republic of China

Department of Organic Chemistry, University of Medicine and

Pharmacy "Iuliu Hatieganu", Cluj - Napoca, Romania

Beijing Synchrotron Radiation Facilities of Beijing Electron Positron

Collider National Laboratory, People’s Republic of China

143

The organisers are grateful to the

MUNICIPAL COUNCIL OF CLUJ – NAPOCA

for the financial support and to the following sponsors:

S.C. TEHNOFRIG S.A.

 COOP. “ARTA JUCĂRIILOR”

SONIC S.R.L.

S.C. INPLAST PROD. MIXT COMP. S.R.L

JASCO ABLE S.R.L.

REDOX TRADING 2000 S.R.L.

NATEX S.R.L.

S.C. ELADOR S.A.

S.C. URSUS S.A.

S.C. PRODVINALCO S.A.

S.C. NAPOLACT S.A.

S.C. PANEGRANO S.A.

S.C. NAPOPAN S.A.

RATUC CLUJ-NAPOCA

144

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