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Laminar Free Convection In Horizontal Annulus Filled With Glass Beads And With Annular Fins On The Inner Cylinder
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An experimental and numerical study has been carried out to investigate the heat transfer by natural convection and radiation in a two dimensional annulus enclosure filled with porous media (glass beads) between two horizontal concentric cylinders. The outer cylinders are of (100, 82 and70mm) outside diameters and the inner cylinder of 27 mm outside diameter with (or without) annular fins attached to it. Under steady state condition; the inner cylinder surface is maintained at a high temperature by applying a uniform heat flux and the outer cylinder surface at a low temperature inside a freezer. The experiments were carried out for an annulus filled with
glass beads at a range of modified Rayleigh number (4.9 ≤ Ra≤ 69), radiation parameter (0<Rd<10), with fin length of (Hf=3, 7 and 11mm), with radius ratios of (Rr=(r1/r2) =0.1405,0.2045, 0.293 and 0.3649 ), number of fins (n=0, 12, 23 and 45). Finite difference method with Boussinesq's approximation is used to solve the continuity, energy and momentum equations.
The numerical solution is capable of calculating the streamline, the temperature field, the velocity field, the local and average Nusselt number. A computer program in Mat lab has been built to carry out the numerical solution. The numerical study was done for a range of modified Rayleigh number (4.9 ≤ Ra ≤ 300). Results show that the average Nusselt number is nearly constant for Ra less than 100 and increased with an increase in modified Rayleigh number.
Nusselt number hardly affected by glass beads size and insignificant affected by Rd for Ra less than 100. Decreasing Rr cause clearly increase in average Nusselt number and increasing fin length or fin number decrease heat transfer.

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Publication Date
Mon Mar 07 2022
Journal Name
Journal Of Educational And Psychological Researches
Awareness of Students at Imam Muhammad bin Saud Islamic University of the Requirements of Married Life in the Light of Social Changes and Methods of Deepening It in Accordance with an Islamic Educational Vision
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This study aims to identify the level of students’ awareness at Imam Muhammad bin Saud University of the requirements of married life in the light of social changes and suggested methods to deepen this awareness (according to the Islamic educational vision) from their own perspective. In this study, the researcher used the descriptive approach with a survey research method, depending on questionnaires to collect data, which he applied to students of College of Sharia in Imam Muhammad bin Saud Islamic University, as well as, students in the fields of Sociology, Social Work, and Psychology in the College of Social Sciences. The findings of the study revealed that students are aware of the requirements of married life concerning mutual ri

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Publication Date
Sat Oct 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
The Intellectual Capital And Its Revenues On The Investment Applied Research On Sample of Banks Listed on In The Iraq Stocks Exchange
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Abstract

      The changes that happened in the environment of  business have great effects upon organizations with different activities specially the banks  which requires the existence of an able opinion  resources can adapt with the changes . Accordingly importance put upon  intellectual  capital which become one of the basic resources for organizations and one of success and growth elements with the availability of expertise , skills and capability of making  essential changes in different process due to the presentation of innovations and creations of the to support banks activities .Therefore the intellectual  capital represents the more r

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Publication Date
Mon Jun 01 2020
Journal Name
Iop Conference Series: Materials Science And Engineering
The possibility of Using the Low-Cost External Antenna with Smartphone for Accurate Surveying Applications by RTX Technology
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Abstract<p>Real Time Extended (RTX) technology works to take advantage of real-time data comes from the global network of tracking stations together with inventor locating and compression algorithms to calculate and relaying the orbit of satellite, satellite atomic clock, and any other systems corrections to the receivers, which lead to real-time correction with high accuracy. These corrections will be transferred to the receiver antenna by satellite (where coverage is available) and by IP (Internet Protocol) for the rest of world to provide the accurate location on the screen of smartphone or tablet by using specific software. The purpose of this study was to assess the accuracy of Global Navig</p> ... Show More
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Publication Date
Mon Jun 01 2020
Journal Name
Iop Conference Series: Materials Science And Engineering
The possibility of Using the Low-Cost External Antenna with Smartphone for Accurate Surveying Applications by RTX Technology
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Abstract<p>Real Time Extended (RTX) technology works to take advantage of real-time data comes from the global network of tracking stations together with inventor locating and compression algorithms to calculate and relaying the orbit of satellite, satellite atomic clock, and any other systems corrections to the receivers, which lead to real-time correction with high accuracy. These corrections will be transferred to the receiver antenna by satellite (where coverage is available) and by IP (Internet Protocol) for the rest of world to provide the accurate location on the screen of smartphone or tablet by using specific software. The purpose of this study was to assess the accuracy of Global Navig</p> ... Show More
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Publication Date
Sun Mar 01 2020
Journal Name
Iop Conference Series: Materials Science And Engineering
Measurement of the distance to the central stars of Nebulae by using Expansion methods with Alladin Sky Atlas
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Abstract<p>The usual methods of distance determination in Astronomy parallax and Spectroscopic with Expansion Methods are seldom applicable to Nebulae. In this work determination of the distances to individual Nebulae are calculated and discussed. The distances of Nebulae to the Earth are calculated. The accuracy of the distance is tested by using Aladin sky Atlas, and comparing Nebulae properties were derived from these distance made with statistical distance determination. The results showed that angular Expansions may occur in a part of the nebulae that is moving at a velocity different than the observed velocity. Also the results of the comparison of our spectroscopic distances with the trig</p> ... Show More
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Publication Date
Thu Feb 01 2024
Journal Name
Baghdad Science Journal
Molecular study of the relationship of gene expression of some genes with the temperature variation of bacterial growth
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Pseudomonas aeruginosa is an opportunistic pathogen responsible for serious infections. At least three different exopolysaccharides, alginate, polysaccharide synthesis locus (Psl), and pellicle exopolysaccharide (Pel) make up the biofilm matrix in P. aeruginosa . The effect of temperature on the biofilm formation and gene expression was examined by microtiter plate and real-time quantitative polymerase chain reaction (qRT-PCR). To be able to determine the effect of temperature on biofilm formation and gene expression of P. aeruginosa, 303 clinical and environmental samples were collected. Pseudomonas aeruginosa was isolated from 61 (20.1%) and 48 (15.8%) of the clinical and e

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Publication Date
Thu Apr 01 2021
Journal Name
Chaos, Solitons &amp; Fractals
Modeling and analysis of an SI1I2R epidemic model with nonlinear incidence and general recovery functions of I1
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In this paper, we established a mathematical model of an SI1I2R epidemic disease with saturated incidence and general recovery functions of the first disease I1. Considering the basic reproduction number, we obtained conditions for both disease-free and co-existing cases. The equilibrium points local stability is verified by using the Routh-Hurwitz criterion, while for the global stability, we used a suitable Lyapunov function to analyze the endemic spread of the positive equilibrium point. Moreover, we carried out the local bifurcation around both equilibrium points (disease-free and co-existing), where we obtained that the disease-free equilibrium point undergoes a transcritical bifurcation. We conduct numerical simulations that suppo

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Publication Date
Sat Mar 08 2025
Journal Name
Chemistry Africa
Preparation, Characterisation, and Photochemical Stability of Polymeric Derivatives of Polyvinyl Alcohol Grafted with Phthalic Anhydride and Dyes
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In this study, derivatives of polyvinyl alcohol (PVA) grafted with phthalic anhydride (PhA) and dyes were prepared to produce polymeric materials of PVA-g-PhA, PVA-g-PhA-anthocyanin, PVA-g-PhA-bromophenol blue, and PVA-g-PhAthymol blue. The materials were characterised by FTIR and 1 H NMR spectroscopies. The crystallinity of the polymers was evaluated with powder X-ray difraction, and the thermal stability by thermogravimetric analysis (TGA). The synthetic procedure for the polymeric materials entailed the formation of esters. The FTIR spectra of the polymers confrmed their formation since the ester carbonyl group stretch was observed at approximately 1691–1716  cm−1 in each material. NMR spectroscopy confrmed the addition of t

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Publication Date
Sun Oct 26 2025
Journal Name
Al-manar Journal Of Medical And Applied Sciences
Synthesis and Characterization of Vanillin Schiff Base Complexes with Paracetamol and Divalent Metal Ions: Antimicrobial Activity Study
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The work presented in this research deals with the synthesis and physico-chemical characterization of Schiff base ligand (HL) created from vanillin with p-aminoazobenzene containing (N, O) as donor atoms. The synthesis ligand (HL) was characterized by the CHN, (FT-IR), (UV-Vis), (1H,13C-NMR) and mass spectroscopy, in addition the melting point were used to charac-terize the Schiff base. A series of mixed metal ligands complexes were formed by using Schiff base ligand (HL) as primary ligand and Paracetamol (PAR) as a secondary ligand with five divalent metal ions; Ni, Cu, Zn, Cd(II) and Hg. The formed complexes were characterized by using some analytical and standard spectroscopic methods; molar conductivity, magnetic susceptibil-ity, FT-IR,

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Publication Date
Fri Jun 29 2012
Journal Name
Synthesis And Characterization Of Metal Complexes With Ligands Containing A Hetero (n) Atom And (hydroxyl Or Carboxyl) Group
Synthesis and Characterization of metal complexes with ligands containing ahetero (N) atom and (hydroxyl or carboxyl) group
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M(II) Ions using amino acid L- proline as a primary ligand and either Nicotinamide or 8- hydroxyqinoline as secondary ligand, respectively: a. The mixed ligand complexes of composition,[M(pro)2(na)2]. b. The mixed ligand complexes of composition , Na[M(pro)2(Q)]. Where proline (C5H9NO2) symbolized as pro H , Nicotinamide (C6H6N2O) symbolized as (NA) , 8- hydroxyqinoline, (C9H7NO2) symbolized as (8-HQ). The ligands and the metal chlorides were brought into reaction at room temperature (37ºc) in ethanol as solvent .The reaction required the following molar ratios [(1:2:2) metal:2NA:2pro-] and [(1:1:2) metal:Q:2pro-] with M+2 ions, where M = [Mn (II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and pd(II)]. Products were found to be solid crystall

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