Seminar Schedule for 2010-2011
1
Seminar schedule for 2010-2011
LHC Physics
by Mr Alan Tua
Department of Physics and Astronomy, University of Sheffield, UK
Date: Monday 2nd May 2011
Time: 15.00 hrs onwards
Venue: CB108
Abstract: The predictive power of the Standard Model of particle physics has been
established to a remarkable degree of accuracy. However we know that it leaves some
questions un-answered: What is dark matter? How do we unify the 4 known forces?
SuperSymmetry, which hypothesizes an entire new set of particles, is one of the most
promising solutions to these issues. In this talk we will look at how and why the
Standard Model fails and what SuperSymmetry does to circumvent these issues. We
will then look at how physicists at CERN are using the LHC to try and discover it.
Department of Physics
University of Malta
Seminar Schedule for 2010-2011
2
Geophysics seminar
The Department of Physics in collaboration with the Department of Civil Engineering
of the Faculty for the Built Environment will be hosting a talk by Professor Maria
Rosaria Gallipoli of the National Council of Research – Institute of Methodologies for
Environmental Analysis, Potenza, Italy on Wednesday 4th of May 2011. Details are
given below:
Empirical estimates of fundamental frequencies and
damping of reinforced concrete buildings before and after
earthquake damage
by Professor Maria Rosaria Gallipoli
National Council of Research – Institute of Methodologies for Environmental Analysis, Potenza, Italy
Date: Wednesday, 4th May 2011
Time: 17.00 onwards
Venue: Room 216 of the Mathematics and Physics Building
Abstract: The aim of this work is to estimate the fundamental frequency and relevant
damping of a large number of existing buildings, performing ambient vibration
measurements. The first part of the work is devoted to the validation of the results
obtained with microtremor measurements, comparing them with those obtained from
earthquake recordings using four different techniques: Horizontal-to-Vertical Spectral
Ratio, Standard Spectral Ratio, Non Parametric Damping Analysis and Half
Bandwidth method. The agreement between the results obtained with microtremors
and earthquakes has encouraged extending the ambient noise measurements to a large
number of buildings. We analyzed the data with the above-mentioned methods to
obtain the two main translational frequencies in orthogonal directions and the relevant
damping for 80 typical Italian buildings and for 244 European buildings.
We have compared the measured frequencies with other experimental results and
theoretical models. Our results confirm, as reported by previous authors, that the
theoretical period-height relationships overestimate the experimental data.
Moreover, the recent Abruzzo earthquake has given us the opportunity to study the
variation of fundamental frequency of reinforced concrete buildings due to earthquake
damage. This activity has highlighted the mismatch between experimental and
numerical value not only for undamaged buildings but also for damaged ones. For the
first time in Italy, due to the April 6th 2009 L’Aquila earthquake, we have estimated
the fundamental periods of 68 RC buildings after a strong seismic sequence. The
fundamental translational frequencies of 68 buildings with different built typology,
structural characteristics, age and heights and damage level, performing ambient
vibration measurements, have been investigated. Four different damage levels were
considered with regard to the 5 damage levels defined by EMS 98 (European
Macroseismic Scale). The fundamental period of RC damaged buildings, for low
damage level, is close to undamaged buildings ones. When damage levels gets higher,
the fundamental periods show as expected a general increase, but reaching values
lower than those provided some recent codes.
Department of Physics
University of Malta
Seminar Schedule for 2010-2011
3
Biography: Dr. Maria Rosaria Gallipoli is full-time researcher at the Institute of
Methodologies of Environmental Analysis of the National Research Council (CNR)
of Italy. She carries out research activities in the field of geophysical methods for
seismic microzonation. Main research interests are applied geophysics for seismic site
response, building response and soil-structure interaction through experimental
analysis of earthquake and ambient noise recordings, regional attenuation studies,
statistical analysis of seismicity data and estimate of seismic hazard at site. She has
participated in several research projects both on national and international scales.
Department of Physics
University of Malta
Seminar Schedule for 2010-2011
4
Climate Change Seminars
The Ministry for Resources and Rural Affairs in collaboration with the Belgian
Embassy, the Department of Physics and the Department of Environmental &
Resources Law, University of Malta will be hosting the following seminar on Climate
Change:
Climate Change: Challenge or Opportunity?
by Prof. Jean-Pascal van Ypersele
Université catholique de Louvain, Earth and Life Institute, Georges Lemaître Centre for Earth and
Climate Research, Chemin du Cyclotron 2, B-1348 Louvain-la-Neuve, Belgium.
Date: Tuesday, 12th April 2011
Time: 18.00 hrs onwards
Venue: Old University Building, St Paul’s Str., Valletta
Abstract: Climate change due to human activities is happening now. The massive
combustion of fossil fuels since the industrial revolution increased the atmospheric
concentration of carbon dioxide, the main anthropogenic greenhouse gas, by 40 %
between 1750 and 2010. The additional infrared heat trapping due to this change in
atmospheric composition will continue to increase the average global surface air
temperature and modify the Earth’s climate. In its fourth Assessment Report (AR4,
2007), the Intergovernmental Panel on Climate Change (IPCC) Working Group I
reports that in the absence of climate protection policies, continued emissions are
likely to increase this global temperature by 1.6 to 6.9 °C between the pre-industrial
period and 2100, depending on which scenario and model is used. Such rates of global
climate change are rapid and very unusual in the context of changes over the past two
million years. The hydrological cycle will also be affected, with, e.g., significant
drying of the average Mediterranean basin. Besides changes in the average climate,
the probability of occurrence of heat waves (virtually certain), heavy precipitation
events (very likely), intense tropical cyclones (likely), and extreme high sea level
(likely) is due to increase in a warming climate. IPCC Working Group II assessed the
impacts that would accompany such warming. For the lowest temperature increase,
crop productivity would increase slightly at mid- to high latitudes but decrease at
lower latitudes, especially in seasonally dry and tropical regions; hundreds of millions
of people would be exposed to increased water stress; up to 30 % of living species
would be at increasing risk of extinction, coral bleaching would increase; coastal
regions would be subjected to increased damage from flood and storms, heat waves,
floods, and droughts would induce increased morbidity and mortality. Damage
increases in most areas for higher temperature increases. Overall, the “reasons for
concern” put forward by the IPCC in 2001 are confirmed and strengthened. IPCC
Working Group III deals with the mitigation options, looking at their technical and
socio-economic aspects, and at the policies that can help implementing them. It has
shown that climate-friendly policies offer opportunities to move our economy and
social systems towards a more sustainable model of development. The potential for
mitigation is huge, and for the lowest range in concentration stabilization levels
assessed, 445 to 535 ppm of CO2-equivalent (which means that global CO2 emissions
need to peak before 2015-2020 and leads in the long term to a temperature increase
Department of Physics
University of Malta
Seminar Schedule for 2010-2011
5
between 2 and 2.8 °C above pre-industrial), the reduction of the world average annual
GDP growth rate is less than 0.12 percentage points in 2050. Energy conservation and
renewable energies play a key role in such climate mitigation efforts, and this
provides large opportunities in terms of job creation. Policymakers and economic
actors are now increasingly aware of both the causes and the consequences of climatic
change. Many are still underestimating the size of the challenge, and do not fully
appreciate the opportunities that the appropriate combination of mitigation and
adaptation policies could deliver. This talk will review both these challenges and
opportunities, and explain the role of the IPCC in assessing them so that all decisionmakers can act more resolutely to implement climate policies.
Biography: Jean-Pascal van Ypersele (1957, Belgium), has a Ph. D. in physics from
the « Université catholique de Louvain » (Louvain-la-Neuve, Belgium), where he is
professor of climatology and environmental sciences, and directs the Master
programme
in
Science
and
Management
of
the
Environment
(www.uclouvain.be/cgse). He made his doctoral research in climatology at NCAR
(National Center for Atmospheric Research, Colorado, USA). He specialized in
modelling climate and the climate effects of human activities, and has recently
focused his research on the impacts of climate change and on integrated assessment
modelling. He chairs the Energy & Climate Working Group of the Belgian Federal
Council for Sustainable Development (www.cfdd.be). Since 2002, he is member of
the Bureau of the IPCC (www.ipcc.ch, Intergovernmental Panel on Climate Change,
which shared the 2007 Nobel Peace Prize with Al Gore), and has been elected Vicechair of IPCC in 2008. In 2009, he was elected a Member of the Belgian Royal
Academy. He has participated to a number of United Nations conferences on climate
issues, as scientific advisor. Among other prizes, he received in 2006 the « Energy
and environment award » from the International Polar Foundation, and the “Francqui
Chair” from the Université libre de Bruxelles in 2007-2008. (E-mail:
jeanpascal.vanypersele@uclouvain.be, web site: www.climate.be/vanyp).
Department of Physics
University of Malta
Seminar Schedule for 2010-2011
6
Exoplanets, a fantastic new domain in Astronomy
By Professor Pierre Léna
Date: Tuesday, 22nd March 2011
Time: 18.00 hrs onwards
Venue: Aula Magna, University of Malta, Valletta
Abstract: After a quest lasting nearly two centuries the first planet around another
star than the Sun was discovered in France by two Swiss astronomers in 1995. The
Entretiens sur la pluralité des mondes from Fontenelle were at last meeting reality.
Since then, over 450 exo-planets (as they are named) have been found, in orbit around
so many stars that the universal existence of planetary systems around a large fraction
of the existing stars is now accepted. Many observational techniques with the largest
existing telescopes or space missions are devoted to this quest, the ultimate goal of it
being indeed to discover the existence of life outside our Solar system.
Biography: Member since 1991 of Académie des sciences (Paris), Pierre Léna, born
1937 in Paris, is an astrophysicist, highly involved in science education issues. He is
Emeritus Professor of astrophysics and physics at the Université Paris Diderot, where
he accomplished most of his teaching career, doing his research as an associate
researcher with Paris Observatory, where he developed and directed a large research
group. The scientific work of Pierre Léna is centered on infrared astronomy, a major
branch of astronomy born ca.1960. With novel observations, he contributed to model
the solar atmosphere and its temperature minimum. Adapting to infrared the speckle
interferometry discovered by the French Antoine Labeyrie, he was first with his
students to apply it to star formation and measure the size of dust cocoons around
forming stars. This work led him to organize the European Very Large Telescope as
an interferometer, again following Labeyrie’s ideas. This world’s most powerful
instrument is now operating. He then worked on a new interferometer, connecting
with optical fibers large telescopes on Mauna Kea (Hawaii). Beginning 1984, he led a
team first implementing adaptive optics on a telescope, a technique now worldwide
adopted on giant instruments. He is the author of more than 100 scientific articles,
author of several books on astrophysics, on education in science, popular books and
television series.He represented France at the governing Council of the European
Southern Observatory (1986-1993) at the time of the VLT planning, directed the
Graduate School of Astrophysics at Université Paris 7 (1976-1984 & 1992-1996)
before becoming Director of the Ecole doctorale Astronomie d’Ile-de-France (19972003). His interest in educational matters led him to become Président of the Institut
national de recherche pédagogique (1991-1997) and to be an active member of the La
main à la pâte (Inquiry & Hands On) action renovating science education in schools
since 1996. He was Président of the Société française de physique in 1989. Since
2005, he leads the Education Office of the French Académie des sciences and pursues
the work on science education at national, european and international scales. Pierre
Léna is a member of Academia Europeae and of the Pontifical Academy of Sciences.
Department of Physics
University of Malta
Seminar Schedule for 2010-2011
7
Geophysics seminar
The Department of Physics of the University of Malta is proud to host two talks by
Alessandra Maria Lotteri and Matthew R. Agius on the 4th of March 2011. Details are
given below.
Date: Friday, 4th March 2011
Time: 14:00-16:00
Venue: Room 401 of the Mathematics and Physics building
Reconstruction of a platform-basin system with the specialized software MOVE
2009
The Concarena Massif (Ladinian, Southern Alps)
By Alessandra Maria Lotteri, Fabrizio Berra, Marco Binda
From the Dipartimento di Scienze della Terra, University of Milan, Italy
Abstract: This talk concerns the 3D geometry’s reconstruction of platform-basin
system of Anisian-Ladinian succession of Concarena’s Massif (Southern Alps)
situated in the North of Italy. This region is characterized by the presence of thick
carbonate platforms separated by basinal troughs and seaways. The exact stratification
depends on the location. In order to carry out the investigation, models of this area
have been created using the software MOVE 2009 with inputs from both direct field
work as well as pre-existing data. The results allow the probing of the underlying
structure of this region giving the thickness of both the basin units and the platform as
well as the inclination. Comparison with other studies gave good agreement.
The crustal and mantle structure beneath Tibet, from shear-velocity profiles
By Matthew R. Agius, Sergei Lebedev
From the Dublin Institute for Advanced Studies, Ireland
Abstract: Tibet lies on top of the world's largest and highest elevated plateau with an
average elevation of more than 5 km. The uplift of the plateau is a result of the
continental collision between India and Eurasia, an impact which shaped the
topography of the entire region. Studies in the last century have concluded that the
crust is double the continental average thickness and Global Positioning System
(GPS) measurements revealed a present day surface deformation rate of 5cm/year.
Although various geophysical studies have been conducted to help understand the
mechanisms taking place beneath the plateau, the processes of the deformation are
still not completely understood. We measure phase velocities of seismic surface
waves to constrain variations in the crustal and lithospheric structure across different
parts of the plateau and try to answer key questions on the mechanism and depth
extent of the deformation.
Department of Physics
University of Malta
Seminar Schedule for 2010-2011
8
Cooling Polarisable Particles with an Optical
Memory
By André Xuereb1, Peter Domokos3, Peter Horak2, and Tim Freegarde1
1
School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ, United Kingdom
Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ, United Kingdom
3
Research Institute of Solid State Physics and Optics, H-1525 Budapest P.O. Box 49, Hungary
2
Date: Wednesday, 17th November 2010
Time: 14:00-15:00
Venue: Room 216 of the Mathematics and Physics building
Abstract: Optical cooling methods are a necessary first step towards achieving fine
enough control over physical systems to enable significant advances in metrology or
to explore nature at an unprecedented level of detail. Most such cooling methods have
traditionally relied on either the resonant enhancement of forces originating in the
Doppler shift, or on optical pumping mechanisms. Systems, such as simple mirrors,
that demonstrate no such resonances or rich energy level structures cannot be cooled
as easily.
Several approaches to solving this problem involve the use of cavities. Our approach
is to look at a cavity interacting with an optomechanical system as an optical memory,
which introduces a time-delayed component in the forces acting on the system.
We first look at what we call ‘mirror mediated cooling’, where a point polarisable
particle (an atom, say, or a micromirror) interacts with its time-delayed reflection in a
mirror and thereby experiences a cooling force; the memory here consists of a long
time delay between the particle and the mirror. Such a long delay line is not
experimentally desirable, and we can significantly improve the system by replacing it
with another well-known memory element: a simple Fabry–Pérot cavity. This
‘external cavity cooling’ scheme requires that the particle sits outside the cavity and is
therefore conducive towards integration into atom chip experiments. We analyse this
new system using a simple, but surprisingly useful, model grounded in classical
electrodynamics and show that, even though the particle lies outside the cavity, the
force acting on it is amplified by a factor of the order of the cavity finesse.
Possible realisations of this scheme range from relatively simple modifications to
existing optomechanical experiments, essentially adding a second fixed mirror, to the
use of more exotic structures possessing strong resonances to generate the required
optical delay.
Biography: André Xuereb graduated from the Mathematics & Physics course at the
University of Malta in 2007. After a summer spent at CERN, he left for England
where he is currently reading for a PhD at the University of Southampton. André
spends most of his time working on describing the interaction between light and
matter on a very general level, with a particular emphasis on generically applicable
optical cooling methods based on dissipative dipole forces.
Department of Physics
University of Malta
Seminar Schedule for 2010-2011
9
Earthquake ground motion scenarios for Southern
Italy
By Sebastiano D'Amico
Department physics, University of Malta
Date: Monday, 29th November 2010
Time: 15.30-16.30
Venue: Room 216 of the Mathematics and Physics Building
Abstract: The evaluation of the expected peak ground motion caused by an
earthquake is an important problem in earthquake seismology. It is particularly
important for regions where strong-motion data are lacking. With the approach
presented in this study of using data from small earthquakes, it is possible to
extrapolate the peak motion parameters beyond the magnitude range of the weakmotion data set on which they are calculated. To provide a description of the high
frequency attenuation and ground motion parameters in southern Italy we used
seismic recordings coming from two different projects: the SAPTEX (Southern
Apennines Tomography Experiment) and the CAT/SCAN (Calabria Apennine
Tyrrhenian – Subduction Collision Accretion Network). We used about 10,000
records with magnitudes between M=2.5 and M=4.7. Using regression model with the
large number of weak-motion data and the regional propagation, the absolute source
scaling was determined.
Stochastic simulations are generated for finite-fault ruptures using the derived
propagation parameters to predict the absolute peaks of the ground motion parameters
for several faults, magnitude, and distance range, as well as beyond the magnitude
range of the weak-motion data set on which the input parameter are calculated. We
finally derived a functional form for a predictive relationship valid in the study area
and simulate a possible seismic scenario for the Messina area (Sicily). We also
reproduced the ground motion of the very destructive 1908 earthquake that caused
more than 100,000 victims.
Department of Physics
University of Malta
Seminar Schedule for 2010-2011
10
Climate change research in Malta
An overview of activities
By Noel Aquilina, James Ciarlo`, Norbert Bonnici
Department of Physics, Faculty of Science, University of Malta, Msida MSD 2080, Malta
Date: Thursday, 4th November 2010
Time: 19:30 -21:00
Venue: Erin Serracino Inglott Hall
Abstract: All parties to the UN Framework Convention on Climate Change
(UNFCCC) have a requirement, under Articles 4.1 and 4.8, to assess their national
variability to climate change. They are also required to submit National
Communications, which include discussion of the vulnerabilities and how they are
planning to adapt. Assessment of vulnerability requires an estimate of the impacts of
climate change, which in turn is based on scenarios of future climate. The Department
of Physics was entrusted with the project management to coordinate the preparation of
the First and Second National Communications since 2001.
Almost three years ago, the British High Commission provided some funding for
planting the seeds for climate research within the Department. In 2008, following the
acquisition of a license to install and run the UK Met Office regional climate model
PRECIS (Providing REgional Climates for Impact Studies), the Department of
Physics embarked on climate research. Initially, PRECIS was run on a single
computer. Additional computers were procured with UN Development Programme
(UNDP) funds, and the Malta Climate Team (MCT) was established in order to
enhance the capability of performing more advanced research and to attract more
students and researchers to the topical issues of climate change and its impacts.
Several activities have been undertaken in the last two years and these will be outlined
in this talk.
The latest upgrade has been the installation of PRECIS and other models like
RegCM4 and WRF on the supercomputing facility available at the University of
Malta, which was purchased and commissioned recently as a result of the
Department’s successful proposal for European Regional Development Funds. The
ongoing research and the future plans of the MCT within the Department of Physics
will be presented and an invitation extended to scientists who would like to join our
efforts within a scientific community and to contribute to the growing body of
knowledge in what could ultimately be the most significant topic of the 21st century –
Climate.
Department of Physics
University of Malta
Seminar Schedule for 2010-2011
11
A machine learning approach to modelling of
personal exposure to volatile organic compounds
By Eric Pace1,2, Denis Cutajar1,2, Arielle Mamo1,
Adam P. Gauci2, Noel Aquilina1,3,
Juana Mari Delgado Saborit3 and Roy M. Harrison3
1
Department of Physics, Faculty of Science, University of Malta, Msida MSD 2080, Malta
2
Department of Intelligent Computer Systems, Faculty of ICT, University of Malta, Msida MSD 2080,
Malta
3
Division of Environmental Health and Risk Management, School of Geography,
Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT,
United Kingdom
Date: Friday 29th October 2010
Time: 14:00-15:00
Venue: Room 216 of the Mathematics and Physics Building
Abstract: Artificial Neural Networks (ANNs) and Decision Trees (DT) are machine
learning methods in use for various applications. In this project carried out during
summer 2010, in collaboration with the University of Birmingham, UK, these
methods were for the first time used to predict the personal exposure (PE) to volatile
organic compounds (VOC). Such techniques are able to consider attributes obtained
from time-activity diaries that concurrently affect the PE and build a corresponding
class description which can be adopted for subsequent classification. The applicability
of dimension reduction algorithms to identify the most important attributes in the
available dataset was also researched. Tests were carried out to identify the best
classification method using both the full attribute set and a reduced attribute set
obtained after applying the Information Gain (IG) and Correlation-based Feature
Subset (CFS) algorithms. The performances of the models developed were compared
through a classification accuracy methodology based on concentration bin sizes. Even
when the input is a limited number of attributes, the generated models offer good
classification accuracies and are able to classify PE in five levels for most of the VOC
exposures tested. The seminar will discuss our findings and propose other techniques
to be used in this type of application considered as the basis of epidemiological
studies and of importance due to its public health implications.
Department of Physics
University of Malta
Seminar Schedule for 2010-2011
12
Large eddy simulations of environmental flows:
from laboratory scale numerical experiments towards
full scale application
By Prof. Vincenzo Armenio
IE-Fluids
Dipartimento di Ingegneria Civile e Ambientale, Università di Trieste, Italy
Date: Wednesday, 6th October 2010
Time: 15:30 - 17:00
Venue: Room 216 of the Mathematics and Physics Building
Abstract: Over the last two decades large eddy simulations has proved to be a robust
and reliable tool to study fluid dynamics turbulent fields of environmental interest.
The use of state-of-art subgrid scale, constant-free models, allowed to treat wall
bounded flows in a very accurate way. The use of wall-resolving LES allowed
studying a wide class of problems of environmental interest, characterized by the
presence of rotation, stratifications and of dispersed phases.
However when moving toward high Reynolds number practical flows, the main hope,
namely straightforward application of the numerical and modelling technologies
developed in the framework of wall-resolving LES to full-scale, real life problems has
revealed to be too much optimistic. In the seminar, an overview on LES methodology
is first given together with examples of studies carried out by the research group of
Prof. Armenio. Successively problems arising when moving toward High-Reynolds
number applications are discussed together with the techniques in use at IE-Fluids to
overcome these problems. Finally examples of applications of LES to full scale
problems are discussed.
The present seminar has been given at:






Dept. of Mechanical and Aerospace Engineering, University of California San
Diego, UCSD, USA
Center for Environmental Research, Arizona State University , ASU, USA
Department of Mechanical Engineering-Center for Turbulence Research
(CTR), Stanford Universuty, USA
University Center for Atmospheric Research, (UCAR), USA
MOX, Politecnico di Milano, Italy
University of Palermo, Italy
Department of Physics
University of Malta