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Free Convection in an Inclined Concentric Annular Square Cavities Filled With Porous Medium and Heated By Non-Uniform Temperature
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A numerical study of the two-dimensional steady free convection flow in an inclined annulus between two concentric square cavities filled with a porous medium is presented in this paper for the case when the side outer walls are kept with differentially heated temperature while the horizontal outer walls and the inner walls are insulated. The heated wall is assumed to have spatial sinusoidal temperature variation about a constant mean value. The Darcy model is used and the fluid is assumed to be a standard Boussinesq fluid. For the Cartesian coordinate system, the governing equations which were used in stream function form are discretized by using the finite difference method with successive under – relaxation method (SUR) and are solved by Gauss-Siedel iterative method. The upwind scheme was used for the transport terms in the energy conservation equation. The results are presented to demonstrate the streamlines, the isotherms, and the Nusselt number depending on the Rayleigh number ranging from (Ra =10 to 1000), dimension ratio from (Dr = 0.15 to 0.45), and the inclination angle from (= 0o to 45o). Also the effects of the amplitude (=0 to 1) and the wave number (f =0 to 5) of the heated side wall temperature variation on the free convection are investigated. The results show the effect of previous parameters (Ra, Dr,, , and f) on the flow fields and temperature profiles. It also show that the average Nusselt number is a strong function of the Rayleigh number, inclination angle, dimension ratio, and temperature variation. The peak value of the average Nusselt number based on the hot wall temperature is observed to occur at dimension ratio of (0.15), inclination angle of (40.1°), amplitude and wave  number (1 & 0.75) for Rayleigh number of (1000).

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Publication Date
Thu Jan 01 2015
Journal Name
Political Sciences Journal
Iraq's role in US security arrangements In the Greater Middle East project
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إن موضوع الشرق الأوسط بشكل عام اتخذ أهمية كبيرة في الكتابات والمؤلفات التي صدرت منذ بداية النصف الأول من عقد التسعينات من القرن المنصرم مع بدايات مشاريع السلام التي أعقبت انهيار الاتحاد السوفيتي وتغير الخارطة السياسية والاقتصادية والايديولوجية للعالم .وعلى الرغم ان المصطلح ليس بجديد الا ان تعابير المصطلح وددلالاته تتغير مع تغير موازين القوى واتجاهات المصالح. إذ انتقل من مصطلح جغرافي الى

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Publication Date
Sun Jul 01 2012
Journal Name
Journal Of Techniques مجلة التقني
A STUDY OF SOME TECHNICAL AND ECONOMICAL PARAMETERS FOR MACHINERY UNIT (NEW HOLLAND &DISC PLOW) BY USING THREE DIFFERENT TILT ANGLES دراسة بعض المؤشرات الفنية والأقتصادية للوحدة الميكنية (الجرار نيوهولاند مع المحراث القرصي الثلاثي القلاب) بأستخدام زوايا ميل مختلفة للأقراص
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Publication Date
Mon Mar 18 2019
Journal Name
Baghdad Science Journal
Enhancement of hydrothermally Co <sub>3</sub> O <sub>4</sub> thin films as H <sub>2</sub> S gas sensor by loading yttrium element
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The gas sensing properties of Co3O4and Co3O4:Y nano structures were investigated. The films were synthesized using the hydrothermal method on a seeded layer. The XRD, SEM analysis and gas sensing properties were investigated for Co3O4and Co3O4:Y thin films. XRD analysis shows that all films are polycrystalline in nature, having a cubic structure, and the crystallite size is (11.7)nm for cobalt oxide and (9.3)nm for the Co3O4:10%Y. The SEM analysis of thin films obviously indicates that Co3O4possesses a nanosphere-like structure and a flower-like structure for Co3O4:Y.The sensitivity, response time and recovery time to a H2S reducing gas were tested at different operating

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Publication Date
Fri Jan 01 2021
Journal Name
Annals Of Tropical Medicine & Public Health
Newly developed method for determination of methyldopa drug using ammonium ceric (IV) nitrate by continuous flow injection analysis via homemade NAG-ADF-300-2 analyser
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A new, simple, sensitive and fast developed method was used for the determination of methyldopa in pure and pharmaceutical formulations by using continuous flow injection analysis. This method is based on formation a burgundy color complex between methyldopa andammonium ceric (IV) nitrate in aqueous medium using long distance chasing photometer NAG-ADF-300-2. The linear range for calibration graph was 0.05-8.3 mmol/L for cell A and 0.1-8.5 mmol/L for cell B, and LOD 952.8000 ng /200 µL for cell A and 3.3348 µg /200 µL for cell B respectively with correlation coefficient (r) 0.9994 for cell A and 0.9991 for cell B, RSD % was lower than 1 % for n=8. The results were compared with classical method UV-Spectrophotometric at λ max=280 n

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Publication Date
Tue Jan 31 2017
Journal Name
Journal Of Engineering
A Study on the Removal of Direct Blue 71 Dye From Textile Wastewater Produced From State Company of Cotton Industries by Electrocoagulation Using Aluminum Electrodes
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The removal of direct blue 71 dye from a prepared wastewater was studied employing batch electrocoagulation (EC) cell. The electrodes of aluminum were used. The influence of process variables which include initial pH (2.0-12.0), wastewater conductivity (0.8 -12.57) mS/cm , initial dye concentration (30 -210) mg/L, electrolysis time  (3-12) min, current density (10-50) mA/cm2   were studied in order to maximize the color removal from wastewater. Experimental results showed that the color removal yield increases with increasing pH until pH 6.0 after that it decreased with increasing pH. The color removal increased with increasing current density, wastewater conductivity, electrolysis time, and decreased with increasing the concen

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Publication Date
Tue Feb 14 2023
Journal Name
Journal Of Educational And Psychological Researches
The Role of Ethical Leadership in Achieving Comprehensive Quality Standards in Public Education Schools in Al-Ardha Governorate
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Abstract

The aim of the research is to identify the role of ethical leadership in achieving comprehensive quality standards in public education schools in the Al-Ardha governorate. To achieve this goal, the descriptive approach was used, the researcher developed a questionnaire consisting of (35) items, divided into two sections: the first one is related to ethical leadership includes (17) items, and the second section relates to total quality management includes (18) items. The research sample consisted of (405) teachers from the stages of public education. The results showed that the level of ethical leadership practice (ethical personal characteristics, ethical administrative features, teamwork, and human rela

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Publication Date
Sun May 02 2021
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The extent of adopting the dimensions of the Blue Ocean Strategy and its impact in the market share: بحث استطلاعي في شركة الحمراء للتأمين
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With the increase in competition between insurance companies in addition to the increasing numbers in the number of insurance companies, whose number decreased to (32) private companies until the end of the year (2020). The blue ocean at the level and its effects on increasing the market share. Therefore, the two researchers tested the hypothesis and the research concluded that there is a relationship A .Also the researcher put some recommendations the most prominent is that the invention is considered one of the successful strategies an d the company has to encourage the employees according to inventive thoughts

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Publication Date
Fri Oct 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
The effect of some short-term debt instruments on the money supply and its effect on the production of wheat crop in Iraq during the period (1990_2018).
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The research aims to show the effect of some short-term debt instruments (central treasury transfers, cash credit granted to the government by commercial banks) on the production of the wheat crop in Iraq, through its effect on money supply during the period (1990-2018), As the study includes two models according to the statistical program (Eviews9), the first model included measuring the effect of short-term debt instruments on money supply, and the second measuring the extent of the money supply's impact on Wheat crop production, as the results of the standard analysis showed that the short-term debt instruments used in the model were Significant effect on wheat crop production indirectly through its effect on money supply, As

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Publication Date
Sat Jun 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
The Effectiveness of Management Information Systems (MIS) and its impact on Governmental Organization Performance in Jouf Region of Saudi Arabia
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The aim of this research is to find the impact of the efficiency of Management information systems (MIS) on the effectiveness of governmental organizations performance.

To achieve the objective of the research, the analytical descriptive method was adopted. A questionnaire was designed consisting of (35) paragraphs, and the sample consisted of (200) individual. The research attemped to answer the following question: To achieve the objective of the research, the analytical descriptive method was adopted. A questionnaire was designed consisting of (35) paragraphs, and the sample consisted of (200) individual. The research tried to answer the following question: What is the actual utilization of modern admi

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Publication Date
Fri Mar 01 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Evaluation of accounting procedures for joint arrangements in the Iraqi environment and their reflection on the quality of financial reporting
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The research aims to assess the local accounting procedures related in one of developments that have taken place, and largely on the structure of the Iraqi economic activity. But a partnership between the (public and private sector), or one of the types of joint arrangements, and through the use of the analytical method and extrapolate the reality of the accounting treatments in Company research sample. Research found to a number of conclusions that the unified accounting system applied in the economic units that deal with contracting joint arrangements formula suffers from obvious shortcomings, and reflected the common arrangements suffer from obvious shortcomings. and reflected on the quality of financial reporting, and the urgent need

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