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Ikhmayies S.J.,Isra University of Jordan | Ahmad-Bitar R.N.,University of Jordan
Materials Science in Semiconductor Processing | Year: 2013

Polycrystalline cadmium telluride (CdTe) thin films were prepared by vacuum evaporation on glass substrates at ambient temperature. X-ray diffraction pattern (XRD) showed that the films are polycrystalline with predominant zinc blend structure. A strong reflection from the (111) plane of the cubic phase was seen beside two weak reflections from the (220) and (311) planes of the same phase. Three very weak lines that are characteristic of elemental tellurium were also observed. The average grain size was estimated by using Sherrer's formula and found to be 24±1 nm. The scanning electron microscope (SEM) image showed a uniform surface with submicron grain size. The difference between grain size obtained from Sherrer's formula and that observed in the SEM micrograph means that each grain consists of a large number of smaller crystallites. The composition of the films was explored by using energy dispersive spectroscopy (EDS), which revealed that the surfaces of the films have excess tellurium. The transmittance was measured in the wavelength range λ=400-1100 nm and used to estimate the optical bandgap energy Eg which was found to be Eg=1.48±0.01 eV. The absorption coefficient was calculated and plotted against the photon's energy and tailing in the bandgap was observed. This tailing was found to follow the empirical Urbach rule. The width of the tail was estimated and related to localized states. The linear current-voltage (I-V) plots were used to find the resistivity ρ, where a value of ρ=2.10×106 Ω cm was obtained. © 2012 Elsevier Ltd.

Ikhmayies S.J.,Isra University of Jordan
Journal of Electronic Materials | Year: 2016

Zinc oxide (ZnO) microrods were synthesized by the spray pyrolysis technique on aluminum substrates at a substrate temperature of 350 ± 5°C. The samples were characterized by x-ray diffraction (XRD), x-ray fluorescence (XRF), scanning electron microscopy (SEM), and energy dispersion x-ray spectroscopy (EDX). XRD diffractograms presented the wurtzite (hexagonal) structure with (002) as the preferential orientation. The SEM observations showed typical microrods of hexagonal cross sections with lengths in the range 1.0–2.5 μm and diameter in the range 300–400 nm. XRF and EDX analysis revealed that the samples contain chlorine, and other impurities, which are related to the aluminum substrate and the starting material zinc chloride (ZnCl2). It is found that the microrods are rich in oxygen, which make them of potential use in gas sensors, besides solar cells, lithium ion batteries and other electo-optic devices. © 2016 The Minerals, Metals & Materials Society

Ikhmayies S.J.,Isra University of Jordan
International Journal of Hydrogen Energy | Year: 2016

Polycrystalline, fluorine doped tin oxide (SnO2:F) thin films were prepared by the low cost spray pyrolysis (SP) technique on glass substrates at 400 °C. To study the influence of annealing on the optical properties, the films were annealed in nitrogen atmosphere at 400 °C for 30 min. Scanning electron microscopy (SEM), energy dispersion X-ray spectroscopy (EDX), and transmittance spectroscopy were used to characterize the films. It is found that annealing reduces the transmittance and direct optical bandgap energy, and increases the reflectance, extinction coefficient, refractive index, real and imaginary parts of the dielectric constant, dispersion parameters, loss factor, and optical conductivity. These results are important for the use of tin oxide in solar cells and optoelectronic devices. © 2016 Hydrogen Energy Publications, LLC.

Sabri O.,Isra University of Jordan
ACM International Conference Proceeding Series | Year: 2015

Cloud Computing is technological trend that enable sharing resources between users through Internet in an on-demand manner. The services of cloud computing reduces the costs of computing and communication which increases the interest to companies around the world. However, many organizations are finding greater obstacles for adoption to this new technology. In this paper we use DeLone and McLean successes model to assess some components that need to be considered by an organization when making the decision of adopting cloud computing. The organization will be able to identify its weakness and strength for each factor, and then build and prepare plan that can help them to make appropriate decision toward a successful adoption of Cloud Computing. Copyright 2015 ACM.

Mohammad M.A.,Isra University of Jordan
Journal of Chromatography A | Year: 2013

The calculated data of inverse gas chromatography (IGC) vary depending on the calculation methods and the n-alkane series. To overcome IGC data variability, this paper combines the Van Oss-Good-Chaudhury concept, the Dorris-Gray equation, the Schultz equation, the Fowkes equation and group contribution theory to establish the chromatographic adhesion law and its equation is Kia=eδEia/kT. In the equation, Kia is the adhesion retention factor of a chemical group, δEia represents the increased chromatographic adhesion energy due to this group and kT expresses the thermal kinetic energy of the molecule containing this group. The dispersive component (γSd), the electron acceptor component (γS+) and the electron donor component (γS-) of a solid surface are then calculated from δEia. Through correlating the retention time with the adhesion energy, this law expresses mathematically the chromatographic adhesion phenomenon of IGC at the infinite dilution region. This paper also derives a new equation to calculate the retention time of a non-adsorbing probe (dead retention time). © 2013 Elsevier B.V.

Afaneh S.,Isra University of Jordan | Zitar R.A.,University of Jordan | Al-Hamami A.,Amman Arab University
Applied Soft Computing Journal | Year: 2013

This paper presents a novel approach for computer viruses detection based on modeling the structures and dynamics of real life paradigm that exists in the bodies of all living creatures. It aims to develop an algorithm based on the concept of the artificial immune system (AIS) for the purpose of detecting viruses. The algorithm is called Virus Detection Clonal algorithm (VDC), and it is derived from the clonal selection algorithm. The VDC algorithm consists of three basic steps: cloning, hyper-mutation and stochastic re-selection. In later stage, the developed VDC algorithm is subjected to validation, which consists of two phases; learning and testing. Two main parameters are determined; one of them is setting the number of signatures per clone (Fat), while the other defines the hypermutation probability (Pm). Later on, the Genetic Algorithm (GA) is used as a tool, to improve the developed algorithm by searching the values of the main parameters (Fat and Pm) to reproduce better results. The results have shown that the detection rate of viruses, by using the developed algorithm, is 94.4%, whereas the detection rate of false positives has reached 0%. These percentages indicate that the VDC algorithm is sufficient and usable in this field. Moreover, the results of employing the GA to optimize the VDC algorithm have shown an improvement in the detection speed of the algorithm. © 2012 Elsevier B.V.

Ikhmayies S.J.,Isra University of Jordan
Energies | Year: 2016

Understanding the properties of CdSTe ternary alloys is important because they always form at the interface between the CdS window layer and CdTe absorber layer in CdS/CdTe solar cells due to the intermixing. This interdiffusion is necessary because it improves the device performance. Experimental work has been devoted to studying Te rich p-type CdSxTe1-x alloys, but there is a lack of studies on S-rich n-type CdS1-yTey solid solutions. In this work, a review of the structure, morphology, and optical properties of the S-rich n-type CdS1-yTey thin films produced by the spray pyrolysis technique on glass substrates is presented. © 2016 by the author.

Ikhmayies S.J.,Isra University of Jordan | Ahmad-Bitar R.N.,University of Jordan
Renewable Energy | Year: 2013

Tin oxide (SnO 2) thin films with thickness in the range 100-600 nm were prepared by vacuum evaporation on glass substrates at ambient temperature. X-ray diffractograms showed that the films have poor crystallinity. The transmittance of the films was measured at room temperature in the wavelength range 290-1100 nm. The absorption coefficient was plotted as a function of photon's energy for films of different thickness and oscillatory behaviour was observed in the high energy side. This oscillatory behaviour which was found to increase with film thickness is evidence on the presence of nanoparticles. Direct and indirect optical bandgap energies were estimated and found to be decreasing with film thickness. Urbach tailing in the bandgap was observed and the width of the tail which is related with disorder and localized states was estimated and found to be decreasing with film thickness. © 2012 Elsevier Ltd.

Al-Shargabi B.,Isra University of Jordan
Proceedings - 2016 International Conference on Information Systems Engineering, ICISE 2016 | Year: 2016

Nowadays, the widespread of the application of web services opens new dawn for e-government applications due to its interoperability that brought by application of web services. Securing the communication between web services has been progressively becoming more demanding requirement for users, administrators, and web service providers. Thus, the need for a security trust model to ensure a proper and secure communication between web services. In this paper, a security trust model is introduced to secure the communication and interaction between governmental web services through a trusted third party controlled by any governmental agency. © 2016 IEEE.

Ikhmayies S.J.,Isra University of Jordan | Ahmad-Bitar R.N.,University of Jordan
Solar Energy | Year: 2012

In CdS/CdTe solar cells it is necessary to determine the efficiency limitations related with the intermixing at the interface between the CdS window layer and CdTe absorber layer. So understanding the properties of the solid solution (CdS xTe 1-x on the CdTe side which is CdTe rich and CdS 1-yTe y on the CdS side which is CdS rich) that is always formed in this region is essential. We produced thin films of CdS 1-yTe y solid solution-which is CdS rich - by first producing CdS:In thin films on glass substrates by the spray pyrolysis technique and then annealing the films in nitrogen atmosphere at 400°C in the presence of Te vapor. We are the first who produce this solid solution by this simple and low cost method. The composition and morphology of the films were determined by energy dispersive X-ray detection (EDAX) measurements and scanning electron microscopy (SEM) observations respectively. Eight values of y in the range 0≤y≤0.2845 were obtained. The transmittance was measured and used to investigate the optical bandgap energy by using the second derivative of the absorbance. It is found that the films show a single hexagonal phase for y≤0.0852 and then a mixed (hexagonal and cubic) phase for 0.0997≤y≤0.2845. Bandgap energies in the range 2.259≤E g≤2.528eV were obtained. Urbach tailing in the bandgap was also investigated. © 2012 Elsevier Ltd.

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