International Journal of Application or Innovation in Engineering & Management... Web Site: www.ijaiem.org Email: , Volume 3, Issue 2, February 2014

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International Journal of Application or Innovation in Engineering & Management (IJAIEM)
Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com
Volume 3, Issue 2, February 2014
ISSN 2319 - 4847
EFFECT OF DUST ON TRANSMITTIVITY
OF GLASS
Shatha S.M. Al-azzawi
Department of Physics., College of science, University of Baghdad
Abstract
This paper deals with the effect of accumulated dust on different locations in Baghdad on the transmittance of glass covers
during the whole month of July, We found that the lowest transmittance for the samples are those which were placed south and
west of Baghdad. Therefore, it is advisable to place the solar cells towards the north and east of Baghdad. And also we find the
characterize elemental particle size and composition by different techniques. The x-ray diffraction detected six minerals those are
calcite and quarts, present as a major components, dolomite, kaolinite, gypsum and plagioclase present as miner component.
EDX detected some normal elements presented in our soil.
Keywords: Effect of Dust, transmittance of glass.
1. INTRODUCTION
The interest in converting the solar energy into heat energy by using the solar cells started after the middle of last century.
Many works have been conducted to increase the efficiency of these solar cells [1-3]. Iraq is one of the countries that is
severely exposed to the dust phenomena during March to August due to topography of the land and a low rainfall and also
We have chosen these months because it has the highest annual variation of total (dust, sand, storms, rising dust and
suspended dust). During these months about 75% of total annual dust events occur [4].
Since the dust has great influence on the performance of solar collectors, many attempts have been done to study the dust
phenomena in Iraq [5-8]. In order to overcome dust problems in solar energy systems, it is necessary to know as much as
possible about the dust and dust variations during these time [9-11].
When we talk about dust we must keep in mind fine particles in a size range between a quarter of a micron and about 10
microns. These particles may have, besides their different sizes, different chemical contents and different shapes, all these
facts together determine their behavior.
There are three main crystalline forms of silica, quartz, crystobalite, and trydimite. Occupational exposures to the three
substances are regulate by Occupational Safety and Health Administration (OSHA), a regulatory containing 0.1% or
greater quartz mustbe labeled as a potential carcinogen(4). Other fine powder are less harmful to human health such as
calcite. But the high contain of calcite in the PM 2.5 fraction suggests that potentially toxic effect and may be also extend
into the smaller airways and then lung parenchyma (5)
All the samples were collected withen Baghdad city area.
2. EXPERIMENTAL PROCEDURE
Sixteen sheet glass samples with dimensions of 50x50mm and 3mm thickness and density of 2.481gm/cm3 were prepared
by the "State Establishment of Glass Factory", Rumadi, Iraq. The chemical analyses of the samples were performed in the
laboratories of the "Directorate General of the Geological Survey and minerals investigation are shown in Table 1
Table 1: Composition of glass sample.
Constituents
Percentage %
SiO2
71.90
A2 lO3
Fe2O3
1.79
0.120
Re2O3
1.86
CaO
MgO
6,90
4.23
Na2O
15.04
K 2O
SO3
0.07
0.19
The method of preparation of glass samples was described briefly elsewhere [12].
Volume 3, Issue 2, February 2014
Page 8
International Journal of Application or Innovation in Engineering & Management (IJAIEM)
Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com
Volume 3, Issue 2, February 2014
ISSN 2319 - 4847
For samples were placed north of Baghdad. The same number was placed south, east and west of Baghdad. All the glass
samples were inclined with an angle of 45o to the horizontal, this is because the loss in the transmitted energy is less by
1.3% than when it is horizontal [1].
The transmittance of the samples were measured weekly for one month to see the effect of accumulated dust. The
transmittancey was measured by using Pye Unicam spectrophotometer types sp8-250 and sp3-300 with reflectance unit
SI240. The transmittance (T) values were calculated after measuring the absorbance ( A ) from the following relationship
[12].
A

log(
1
)
T
A 10gm of the measuring sample were placed into a tall water filled measuring cylinder, and shaking vry well for few
minutes and left for 24h to settle all the coarse particles, then a glass slide was attached to thin wire and immersed at a
depth of 10 cm and left for 300h. Then removed and dry at room temperature. X=ray diffraction analysis was used to
qualitatively determine the presence of any crystalline compounds in the dust samples. Scherrer method was applied to
estimate the crystallite size of the fine powder. EDX current with Pd tube applied to detect the light and heavy el
3. RESULTS AND DISCUSSION
Figure 1 represents the transmittance change with the wavelength range (250 – 2750) nm of the glass clean dust-free and
has been using the same glass for the four models that the experiment took place.
T (transmittance)
120
100
80
60
40
20
0
0
500
1000
1500
2000
2500
3000
Wavelength (nm)
clean
Figure 1 Variation of transmittance with wavelength for clean glass
The results of transmittance measurement for samples placed north, south, west and east of Baghdad are shown in figures
2,3,4, and 5, respectively. One can see that the lowest transmittances for the samples are those which were placed south
and west of Baghdad. This is due to the dust laden south western wind traverses the western desert prior to entering the
Iraqi borders and due to a two great belts of mobile sand which constitute the major local sources of mobile sand. The
most active one is the western belt which falls across the Iraqi-Jordanian borders [4]. The second belt is situated south
west across the Iraqi-Saudi border. So, it is advisable to place the solar cell covered by glass sheets towards the north and
east of Baghdad.
T(transmittance)
1st. w eek
2nd. w eek
3rd. w eek
4th. w eek
100
80
60
40
20
0
0
500
1000
1500
2000
2500
3000
Wavelength (nm)
Figure 2 Variation of transmittance with wavelength as function of time for sample 1 (north)
1st. w eek
2nd. w eek
3rd. w eek
4th. w eek
T(transmittance)
80
60
40
20
0
0
500
1000
1500
2000
2500
3000
Wavelength (nm)
Figure 3 Variation of transmittance with wavelength as function of time for sample 2 (south)
Volume 3, Issue 2, February 2014
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International Journal of Application or Innovation in Engineering & Management (IJAIEM)
Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com
Volume 3, Issue 2, February 2014
ISSN 2319 - 4847
1st. w eek
2nd. w eek
3rd. w eek
4th. w eek
T(transmittance)
100
80
60
40
20
0
0
500
1000
1500
2000
2500
3000
W ave l e n gth (n m )
Figure 4 Variation of transmittance with wavelength as function of time for sample 3 (west)
1st. w eek
2nd.w eek
3rd. w eek
4th. w eek
T(transmittance)
100
80
60
40
20
0
0
500
1000
1500
2000
2500
3000
W ave l e ngth (nm )
Figure 5 Variation of transmittance with wavelength as function of time for sample 4 (east)
Fig.2, 3,4 and 5 shows the amount of transmittance for the same glass used in Fig.1. for a period of four weeks, the
figures shows decrease in the amount of transmittance from week to week due to the accumulation of dust on the sample
with the increase of time.
There are in all shapes a jump in the wavelength (500)nm, we believe that this result of manufacturing defects in the
glass.
Three bulk dust samples are shown in Table {1}. The particles distribution variable from area to area, this because of the
direction of the storm and as we know that the coarse particle will fallen first depending on the wind speed, wile the finer
particle taking along time to settle depend on its size. The sizes which affect the respirable system seem to bee in low
concentration in precipitated dust, but this not mean that this size are the real amounts present in atmosphere as airborne.
X-ray diffraction pattern showed that the bulk dust PM53 containing quartz (SiO 2), calcite (CaCO3 ), dolomite
(CaMg(CO3)2), kaolinite (Al2(Si2O5)(OH2)) and plagioclase (NaAlSi3O8CaAl2Si2O8). This composition reflects the nature
mineral in Iraq or within the area. The smallest size obtained by this method was 1µm at a time of 480m.
Figure 6 X-ray diffraction of particulate dust. Q=quartz and C=calcite
One of the famous methods to measure the crystalline size is Scheerer method. The values of the crystallite size of quartz
and calcite are shown in Table 2
Table 2 The results of Scheerer calculation of sizes for quartz and calcite
Mineral
2ϴ
hkl
Size
(nm)
Quartz
20.83
100
30
26.66
101
55
Calcite
23.02
102
10
29.35
104
20
Volume 3, Issue 2, February 2014
Page 10
International Journal of Application or Innovation in Engineering & Management (IJAIEM)
Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com
Volume 3, Issue 2, February 2014
ISSN 2319 - 4847
These values are less than PM 2.5 which means that the air at that time was at risk.
The data of the EDX analysis of the dust samples are quite familiar in local soil such as Si, Ca, S, Fe, K.
4. CONCLUSIONS
We conclude from above study which concerned the effect of accumulation dust for 4 weeks on transmittance of glass as
following:
 Less transmittance is for glass thread south and west of Baghdad.
 This research is recommended developing solar cell toward the north or east of Baghdad to get the highest
transmittance, which is the best for solar cell.
References
[1] Y. Kamel and H.Yusif ., "Proceeding of Solar Energy, New and Renewable Sources of Energy", Baghdad, 1986.
[2] D. M.Deffenbaugh, S.J. Green S. T.and Svedman , "The effect of dust accumulation on line-focus parabolic trough
solar collector performance", 36 2 139, 1986.
[3] R. Main M.Pillai ,"Imact of dust on solar photovoltaic (PV) performance: Renewable statuus challenges and
recommendations" Renewable and Sustainable Energy Reviews, 14 9 3124, 2010.
[4] N. Al-Hamdani , M.A. Al-abbasi and A. Al-BaaliA. , "Fourth scientific conference for the scientific research
council" 3 471, 1986.
[5] Al-Ani A., "Dust phenomena at Baghdad airport from (1950-1960)" , Iraqi met. Organization office publication
1965.
[6] J. Zorrill-Casanova, M. Piliougine, J. Carretero, P. Bernaola , P. Carpena, L. Mora-Lopez, M. Sidrach-de-Cardona,
"Analysis of dust losses in photovoltaic modules", world Renewable Energy Congress, 11 2985, 2011.
[7] A. Ibrahim,"Effect of Shadow and Dust on the Performance of Silicon Solar Cell",Journal of Basic and Applied
Scientific Research,1 3 222, 2011.
[8] M. Piliougine, J. Carretero, M. M.Sidrach-de-Cardona, D. Montiel, P. Sanchez-Friera, "Comparative analysis of the
dust losses in photovoltaic modules with different cover glasses proceedings of 23rd European solar energy
conference, 2698, 2008.
[9] A.A. Hegazy, "Effect of dust accumulation on solar transmittance through glass covers of plate-type collectors" ,
Renewable Energy,22 4 525, 2001.
[10] A.M. El-Nashar, "The effect of dust accumulation on the performance of evacuated tube collectors", Solar Energy,53
1 105, 1994.
[11] A.O. Mohamed , A. Hasan, "Effect of Dust Accumulation on Performance of Photovoltaic Solar Modules in Sahara
Environment" Journal of Basic and Applied Scientific Research, 2 11 11030, 2012.
[12] H. Al-Sharbaty, S. Al-azzawi, " investigation of the permittivity and dielectric loss exhibited by silica glasses", Solar
and Wind Technology,5 6 617, 1988.
Volume 3, Issue 2, February 2014
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