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alkej-107
Natural Convection in Trapezoidal Enclosure Heated Partially from Below
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Natural convection in a trapezoidal enclosure with partial heating from below and symmetrical cooling from the sides has been investigated numerically. The heating is simulated by a centrally located heat source on the bottom wall, and four different values of the dimensionless heat source length, 1/5, 2/5, 3/5, 4/5 are considered. The laminar flow field is analyzed numerically by solving the steady, two-dimensional incompressible Navier-Stokes and energy equations. The Cartesian velocity components and pressure on a collocated (non-staggered) grid are used as dependent variables in the momentum equations  discretized by finite volume method; body fitted coordinates are used to represent the trapezoidal enclosure, and grid generation technique based on elliptic partial differential equations is employed. SIMPLE algorithm is used to adjust the velocity field to satisfy the conservation of mass. The range of Rayleigh number is (103≤ Ra ≤105) and Prandtl number is 0.7. The results show that the average Nusselt number increases with the increases of the source length.

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Publication Date
Sun Mar 01 2009
Journal Name
Journal Of Economics And Administrative Sciences
Use the path analysis method to diagnoseFactors influencing the intentions of the employees of the University of Dhi Qar To introduce Internet behavior
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The purpose of this study is to diagnose factors that effect Thi-Qar behavioral intention to use internet. A sample of (127) internet users of university staff was taken in the study and were analyzed by using path analyze . The study concluded that there is a set of affecting correlation. It was founded that exogenous variables (gender, income, perceived fun, perceived usefulness, Image, and ease of use) has significant effect on endogenous (behavioral intention) . The result of analysis indicated that image hopeful gained users comes first, ease of use secondly, perceived fan and perceived usefulness on (dependent variables (daily internet usage and diversity of internet usage. Implication of these result are discussed . the st

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Publication Date
Thu May 21 2026
Journal Name
Al–bahith Al–a'alami
Framing an argument of Normalization with Israel on the websites of directed satellite channels Analytical study of the sites (Al-Alam, Al-Hurra) channels
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The aim of this paper is to study the frames of Argument of normalization with Israel on the websites of the satellite channels directed in the Arabic language (Al-Alam and Al-Hurra Iraq) channels by analyzing the mechanisms of framing an Argument, The way in which we frame an issue largely determines how that issue will be understood and acted upon، The research adopted the survey method applied to the sites of(Al-
Alam and Al-Hurra) channels, at the period 13 Aug. - 12 Nov. 2020, which included (855) news items, (633) for Al-Alam channel website, and (222) for Alhurra Iraq channel website.
The most important results are: The two channels dependence on the Argument Directed, Al-Alam channel focuses on Islamic and Arab attitudes,

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Publication Date
Wed Aug 07 2019
Journal Name
Iraqi National Journal Of Nursing Specialties
Effectiveness of an Instructional Program Concerning premarital screening of sexual transmitted disease on Student's Knowledge at Baghdad University
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Objectives: To identify the effectiveness of instructional program concerning premarital screening of sexual transmitted disease on student's knowledge at Baghdad University and examine the relationship between students' knowledge and certain studied variables. And hypothesis for this study; There is a difference in university student’s knowledge toward premarital screening between pre and posttests of instructional program. Methodology: A quasi-experimental design (pretest-posttest approach) was conducted at six colleges and its college of education ibn rushd, college of political science, college of law, college of literatur

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Publication Date
Mon Jul 01 2019
Journal Name
المجلة المصرية لبحوث الأعلام
دوافع تعرض طلبة أقسام اللُّغة الإنکليزية في جامعة بغداد للقنوات الفضائية الناطقة باللُّغة الإنکليزية والإشباعات المتحققة عنه:
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تلخصت مشکلة هذا البحث في التعرف على الدوافع التي تقف وراء تعرض الطلبة الدارسين في أقسام اللُّغة الإنکليزية للقنوات الفضائية الناطقة باللُّغة الإنکليزية والإشباعات المتحققة عن هذا التعرض في هذا المجتمع الخاص الذي يشکل بيئة اجتماعية علمية محددة، عن طريق تطبيق نظرية الإستخدامات والإشباعات في إطار المجتمعات الخاصة، وسعى هذا البحث إلى تحقيق ثلاثة أهداف هي، قياس استخدامات لطلبة الدارسين في أقسام اللُّغة الإنک

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Publication Date
Sun Jun 20 2021
Journal Name
Baghdad Science Journal
Investigating the Aerodynamic Surface Roughness Length over Baghdad City Utilizing Remote Sensing and GIS Techniques
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This study calculated the surface roughness length (Zo), zero-displacement length (Zd) and height of the roughness elements (ZH) using GIS applications. The practical benefit of this study is to classify the development of Baghdad, choose the appropriate places for installing wind turbines, improve urban planning, find rates of turbulence, pollution and others. The surface roughness length (Zo) of Baghdad city was estimated based on the data of the wind speed obtained from an automatic weather station installed at Al-Mustansiriyah University, the data of the satellite images digital elevation model (DEM), and the digital surface model (DSM), utilizing Remote Sensing Techniques. The study area w

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Publication Date
Sun Mar 01 2020
Journal Name
Journal Of Engineering
Three-Dimensional Explicit Finite Element Simulation of Piled-Raft Foundation
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This paper aims to validate a proposed finite element model to be adopted in predicting displacement and soil stresses of a piled-raft foundation. The proposed model adopts the solid element to simulate the raft, piles, and soil mass. An explicit integration scheme has been used to simulate nonlinear static aspects of the piled-raft foundation and to avoid the computational difficulties associated with the implicit finite element analysis.

The validation process is based on comparing the results of the proposed finite element model with those of a scaled-down experimental work achieved by other researchers. Centrifuge apparatus has been used in the experimental work to generate the required stresses to simulate t

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Publication Date
Thu Dec 01 2022
Journal Name
Iraqi Journal Of Physics
Numerical Simulation for Cylindrical Electrostatic Precipitator: Effect of the Applied Voltage
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Coaxial (wire-cylinder) electrodes arrangements are widely used for electrostatic deposition of dust particles in flue gases, when a high voltage is applied to electrodes immersed in air and provide a strongly non-uniform electric field. The efficiency of electrostatic filters mainly depends on the value of the applied voltage and the distribution of the electric field. In this work, a two-dimensional computer simulation was constructed to study the effect of different applied voltages (20, 22, 25, 26, 28, 30 kV) on the inner electrode and their effect on the efficiency of the electrostatic precipitator. Finite Element Method (FEM) and COMSOL Multiphysics software were used to simulate the cross section of a wire cylinder. The results sh

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Publication Date
Sat Jul 28 2018
Journal Name
Journal Of Engineering
Experimental and Numerical Analysis of Expanded Pipe using Rigid Conical Shape
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The experimental and numerical analysis was performed on pipes suffering large plastic deformation through expanding them using rigid conical shaped mandrels, with three different cone angles (15◦, 25◦, 35◦) and diameters (15, 17, 20) mm. The experimental test for the strain results investigated the expanded areas. A numerical solution of the pipes expansion process was also investigated using the commercial finite element software ANSYS. The strains were measured for each case experimentally by stamping the mesh on the pipe after expanding, then compared with Ansys results. No cracks were generated during the process with the selected angles. It can be concluded that the strain decreased with greater angles of con

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Publication Date
Fri Dec 25 2009
Journal Name
Wireless Personal Communications
A N-Radon Based OFDM Trasceivers Design and Performance Simulation Over Different Channel Models
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In this paper a new method is proposed to perform the N-Radon orthogonal frequency division multiplexing (OFDM), which are equivalent to 4-quadrature amplitude modulation (QAM), 16-QAM, 64-QAM, 256-QAM, ... etc. in spectral efficiency. This non conventional method is proposed in order to reduce the constellation energy and increase spectral efficiency. The proposed method gives a significant improvement in Bit Error Rate performance, and keeps bandwidth efficiency and spectrum shape as good as conventional Fast Fourier Transform based OFDM. The new structure was tested and compared with conventional OFDM for Additive White Gaussian Noise, flat, and multi-path selective fading channels. Simulation tests were generated for different channels

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Publication Date
Fri May 01 2020
Journal Name
Journal Of Engineering
Effect of Maximum Size of Aggregate on the Behavior of Reinforced Concrete Beams Analyzed using Meso Scale Modeling
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In this study, simply supported reinforced concrete (RC) beams were analyzed using the Extended Finite Element Method (XFEM). This is a powerful method that is used for the treatment of discontinuities resulting from the fracture process and crack propagation in concrete. The mesoscale is used in modeling concrete as a two-phasic material of coarse aggregate and cement mortar. Air voids in the cement paste will also be modeled. The coarse aggregate used in the casting of these beams is a rounded aggregate consisting of different maximum sizes. The maximum size is 25 mm in the first model, and in the second model, the maximum size is 20 mm. The compressive strength used in these beams is equal to 26 MPa.

The subje

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