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In this work, an experimental investigation has been done for heat transfer by natural-convection through a horizontal concentric annulus with porous media effects. The porous structure in gap spacing consists of a glass balls and replaced by plastic (PVC) balls with different sizes. The outer surface of outer tube is isothermally cooled while the outer surface of inner tube is heated with constant heat flux condition. The inner tube is heated with different supplied electrical power levels. Four different radius ratios of annulus are used. The effects of porous media material, particles size and annulus radius ratio on heat dissipation in terms of average Nusselt number have been analyzed. The experimental results show that the average Nusselt number increases with increasing annulus radius ratio and particle diameter for same porous media material. Furthermore, two empirical correlations of average Nusselt number with average Rayleigh number for glass and PVC particles are developed. The present experimental results are compared with previously works and good correspondence is showed. |
Abstract: In the present work, the heat transfer of Nano Aluminum Oxide -NAO- has been studied practically to define the appropriate insulation conditions. This study focuses on finding of the amount of heat transfer through a glass substrate that is coated with nanoalumina doped on PMMA matrix. The optical and thermal properties were systematically investigated. The density of heat flow rate, was calculated in the range values (240-260) W/m2 while the optimum values confine between (250-260) W/m2 at temp. (25-35)Co. The results showed that the thermal insulation of the sample was significantly enhanced at temp. (30-50)Co. The simulated net heat transfer through window decreased linearly with incr
... Show MoreThe research addresses the questioning of political loads in a cinematic model from the films of the author (David Abdel Sayed), who has been busy throughout his films in criticizing political power, where he presented protests visions her body the artistic composition of cinematic means of expression through artistic treatments that facilitate the representations of modernity in contemporary cinematic trends, and by this Several contemporary cinematic criticism is an example of a thinker cinematographer who presents his critical thesis on power politics through the composition of the film (material - form - expression). The research consisted of four chapters. The first was a methodological framework that included the research problem o
... Show MoreThe nucleon momentum distributions (NMD) and elastic electron scattering form factors of the ground state for some 1f-2p-shell nuclei, such as 58Ni, 60Ni, 62Ni, and 64Ni
isotopes have been calculated in the framework of the coherent fluctuation model (CFM) and expressed in terms of the weight function lf(x)l2 . The weight function (fluctuation function) has been related to the nucleon density distribution (NDD) of the nuclei and determined from the theory and experiment. The NDD is derived from a simple method based on the use of the single particle wave functions of the harmonic oscillator potential and the occupation numbers of the states. The feature of the l
Isolation had been done for active substances from Thyme plant (Thymus Vulgaris) such as volatile oils, Saponins and Tannins. The percentage in form was (21.1%),(59.2%),( 9.7%) respectively. Also a study of anti-bacterial activity of extracts from Thyme using two types of pathogenic bacteria Escherichia Coli and aurous Staphylococcus showed the ability of inhibition for all different extracts by vary inhibition diameters for different active substances, concentrations and bacteria. One type of cancer cellular line used to study the effect of Thyme extracts on the growth of cells in the laboratory and thus know the specifications of extracts as anti-tumor, (L20B) cell line have been used which is mice Transformed cell Line. The possibility o
... Show MoreIn this work, prepared new ligand namely 5-(2,4-dichloro-phenyl)-1,3,4-oxadiazole-2-(3H)-thion, was obtained from the 2,4-dichlorobenzoyl chloride with hydrazine, after that reaxtion with CS2/KOH in methanol.
A novel series of mixed-ligand complexes of the type, [ML1(L2)3]Clx [M= Cr(III), Fe(III), Co(II),Ni(II), Cu(II), Cd(II) and Hg(II), n = 2, 3], was synthesized using Schiff base (HL1) as main ligand, nicotinamide (L2) as secondary ligand, and the corresponding metal ions in 1:3:1 molar ratio. The main ligand, HL1 was prepared by the interaction of ampicillin drug and 4-chlorobenzophenone. The synthesized mixed ligand complexes were characterized by elemental analysis, UV-Vis, FT-IR,1H-NMR,13C-NMR and TG/DTG studies. In the mixed-ligand complexes, the Schiff base ligand, HL1 showed coordination to the central metal ion in tridentate manner via azomethine nitrogen, β-lactam ring oxygen and deprotonated carboxylic oxygen atoms, whereas the sec
... Show MoreThe present study aims to give some details about the normal anatomical and histological structure of the liver, pancreas and gall bladder in Cyprinus carpio Linnaeus, 1758 and Mesopotamichthys sharpeyi (Günther, 1874). Anatomical results revealed that the liver of C. carpio is a reddish-brown in color, located in the anterior part of abdominal cavity and dispersed between most of the intestines, which is divided into two lobes; while in M. sharpeyi the liver is light brown in color located in the anterior part of abdominal cavity and extends to the end of the intestinal tract with two lobs. The gallbladder situated in the right side of the liver in both species. Histological results in both species showed that the liver consists
... Show MoreThis study presents a rapid, sensitive, and straightforward approach to measure chlorpheniramine maleate (CPM) by using turbidity CFIA. The method involves CPM reacting with sodium nitroprusside (Nitropress) to produce a pale white precipitate. The NAG-SSP-5S1D analyzer was used to measure turbidity at 0°–180° angle to detect the attenuation of incident light as a result of collision on the surfaces of the precipitate particles. The linear range of CPM measurements was between 0.008 and 11 m.mol/L, with correlation coefficient of 0.9983 and R2% = 99.65. The limit of detection was determined to be 0.0328 µg/sample from the lowest concentration in the calibration curve, and the repeatability of the method (RSD%) was less than 0.4% (n = 6
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