http://dspace-su.server.ly:8080/xmlui/handle/123456789/110 2026-05-10T12:44:44Z http://dspace-su.server.ly:8080/xmlui/handle/123456789/1487 Nanoporous Silica Thin Films Synthesis by Sol-Gel Process Farid M. Hota; Wafia M. Emhalhal Synthesis of thin films of nanoporous silica on glass substrate is very delicate process in sol- gel synthesis technique. Homogeneity of the film prepared and its continuity affected by the conditions of the reaction. It was found that the physical and optical properties of mesoporous thin films prepared through surfactant templating as pore size, pore volume, pore size distribution, and ordering depend on the concentration of the surfactant used. Physical properties of thin film characterized by Nitrogen adsorption isotherm, HRTEM- ED, and Photoacoustic Spectroscopy (PAS). 2014-01-01T00:00:00Z http://dspace-su.server.ly:8080/xmlui/handle/123456789/1483 Statistical Stability in Financial Modeling Dr. Emtair M. Abdalla In this paper, a theory of different stability concepts is developed including α-stability, max- stability and pot-stability. Special cases of stable distributions are introduced with some detail. The properties of heavy-tailedness and asymmetry together with the real line support encouraged in trusting stable distributions and considering them an attractive reliable environment in financial modeling. Modeling procedures are applied on real data of size 600 from the DAX portfolio3 restricted to the financial factors such as profitability, as a ratio of the net income to total assets and net income to sales, leverage , obtained by dividing the equity to total assets, and turnover expressed as a ratio of the sales to total assets. Risk measures such as value at risk and expected shortfall are also modeled via the POT-stable distributions. 2014-01-01T00:00:00Z http://dspace-su.server.ly:8080/xmlui/handle/123456789/140 Characterisation of Ruthenium – Rhenium Dinuclear Complexes using NMR and HPLC Hamid M Younis; Nadia Coburn; Johannes G. Vos Many studies have been conducted on substituting ligands to increase photocatalytic activity but an interesting study was conducted again by our group researchon manipulating these properties by structural changes i.e. using different degrees of communication between the metallic sites and the ligands. Enhancement of photocatalytic activity was achieved when the Ru and Re Centres were bound covalently by providing selective excitation and reductive quenching of the Ru excited state to the Re moiety. Photocatalytic studies on a number of dinuclear systems were carried out and the results showed that the photocatalytic response to light was achieved upon addition of the Ru species where it was covalently linked to the Re Centre. The photocatalyic study also indicated that increasing the number of Re Centres attached to the bridging ligand increased the turnover number. This study was influential on the design of the system to be used in the study presented in this work. 2014-01-01T00:00:00Z http://dspace-su.server.ly:8080/xmlui/handle/123456789/139 3D Fluid flow in an Elbow Meter-CFD Model عبدالسلام محمد مفتاح Elbow meter is one of the common flow measurement systems which are used to determine the pressure difference occurring as a fluid flows change by resistance. This differential pressure exists when a flowing changes direction due to a pipe turn. The pressure difference results from the centrifugal force. . Since pipe elbows exists in plants and its cost is very low. However, the accuracy is very poor [2]. For this reason, the purpose of this paper is to run a CFD Model (Computational Fluid Dynamics) at Elbow meter using Solidworks Flow Simulation [1] with different pipe sizes, ranging from 6 to 12 nominal diameter. The CFD Simulation will be extended to run with using different fluid types, varying as air, steam, oil and water. The goal is to determine the sensitivity of flow measurements in regards to these parameters. CFD results will be compared to a corresponding theoretical solution to investigate how much the accuracy can be improved by changing the geometry of elbow pipe and fluid type. 2014-01-01T00:00:00Z