Asian Transactions on Science & Technology
Volume: 02, Issue: 02, May 2012
Title: Structural, Optical, and Electrical Properties of Nanoparticle 2(CdS)x(CuInS2)1-x Thin Films Prepared by Chemical Spray Pyrolysis
Authors: Hamid S. AL-Jumaili and Ahmed F. Awad
Paper ID: ATST-40222025
Pages: 1 - 10
Abstract: 2(CdS)x(CuInS2)1-x (CCIS) thin films, with x=0,0.1,c,1, are potential absorber layers in thin-film heterojunction solar cells. This study is the first to deposit these films successfully on glass slides using the spray pyrolysis technique at 623K. The films were characterized using X-ray diffraction to find the polycrystalline series of the CCIS solid solution with many phases and a new phase of nanostructured CCIS as a mixture of chalcopyrite and zinc blend. The grain size ranges from 6 nm to 27 nm. The surface morphology was characterized using atomic force and scanning electron microscopy techniques. The optical properties of the prepared thin films were investigated using a UV-VIS spectrophotometer in the wavelength of 300 nm to 1100 nm. The films showed a direct transition with graded optical energy gap (Eg) values varying between 1.4 and 2.3 eV, depending on the x value. The optical constants, such as extinction coefficient (k), refractive index (n), and real and imaginary dielectric constants (.1 and .2), were also discussed. The CCIS thin films exhibit p-type conductivity at x . 0.7 and n-type conductivity at x . 0.9. The films appeared to have one or more activation energies depending on the x value.
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Title: Temporal and spatial variabilities of total ozone column over Iraq
Authors: Saadiyah Hasan Halos
Paper ID: ATST-70221028
Pages: 11 - 17
Abstract: The ozone data obtained from the Ozone Monitoring Instrument (OMI) on Aura satellite have been used to study the temporary and spatial variabilities of Total Ozone Column (TOC) over different cities in Iraq at Baghdad (Lat 33.5° N, Long 44.5° E), Basra (Lat 30.5 ° N, Long 47.5° E), and Mosul (Lat 36.5° N, Long 43.5° E) over a period from October 2004 to December 2011. The daily TOC shows a notable seasonal behaviour which found considered the spring and summer months higher diurnal TOC variations than autumn and winter months. The daily TOC spatial behavior is found to be higher over the northern part of Iraq (Mosul) than the central part (Baghdad) and southern part (Basra). The linear regression technique was applied to the Monthly TOC to study the trends at three Iraqi cities revealed the presence of strong seasonal cycles and resulted stable variations with low coefficient of determination (r2=0.004) for Baghdad, (r2=0.001) for Basra and (r2=0.006) for Mosul indicates that a small percentage of the variations in total ozone. An examination of the yearly mean values of TOC indicates a marked seasonal variation with a maximum around April and a minimum around October. A trend analysis performed on each individual months, October month shows TOC decline in three Iraqi cities with linear trend value, (-1.178) for Baghdad which is lower than for Mosul (-0,904) and Basra (-0.642), while in April month shows a statistically significant TOC ascend with a linear trend value (3.25) for Mosul higher than for Baghdad (2.071), and Basra (1.178).
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Title: A new Numerical Multistep Method for Solution of Second Order of Ordinary Differential Equations
Authors: Mohammed S. Mechee, Norazak Senu
Paper ID: ATST-80134039
Pages: 18 - 22
Abstract: In this paper we study the numerical method for second order of ODE in which the depend variable y does not appear explicitly.
y = f(x, y') a<=x <=b
y (a) = α
y' = β
A new numerical multistep method has been derived which used to solve some of numerical examples during some comparison with analytic solutions. The stability of this method has been studied.
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