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alkej-389
Transient Behavior Analysis for Solar Energy Storage in PCM-CFM Material Using Equivalent Heat Capacity Method as Storage Model
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A paraffin wax and copper foam matrix were used as a thermal energy storage material in the double passes air solar chimney (SC) collector to get ventilation effect through daytime and after sunset. Air SC collector was installed in the south wall of an insulated test room and tested with different working angles (30o, 45o and 60o). Different SC types were used; single pass, double passes flat plate collector and double pass thermal energy storage box collector (TESB). A computational model based on the finite volume method for transient tw dimensional domains was carried out to describe the heat transfer and storage in the thermal energy storage material of collector. Also, equivalent specific heat method was employed to describe the heat storage and release in the mushy zone. Experimental results referred to an increase in thermal conductivity of paraffin wax that supported by copper foam matrix more than ten times. While the ventilation effect was still active for hours after the sun set, depending on the heat storage amount. Maximum ventilation mass flow rate with TESB collector was recorded with value equals to 36.651 kg/hr., when the overall discharge coefficient that was calculated for the system equals to 0.371. Experimental results showed that the best working angle range was 45~60o, and the highest air to the collector approaching temperature appeared to the double passes flat plate collector. Results gave greater heat storage efficiency of (47)% when the maximum solar radiation was 780 W/m2 at 12.00pm, while the energy summation through duration charge time was 18460 kJ. Computational results, depending on the equivalent heat capacity method for heat storage or release from phase change material that supported by copper foam matrix, showed the behavior of paraffin wax melting and solidification situation through periodic for charge and released heat from the solar collector. Also, these results gave agreement approaching the experimental results for the heat storage in the combined heat storage material, with standard error of 16.8%.

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Publication Date
Thu Oct 01 2015
Journal Name
Journal Of Educational And Psychological Researches
القيادة التربوية في ضوء نظريتي x-yوعلاقتها بالروح المعنوية لمديري المدارس الإعدادية
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This study aimed to identify the educational leadership in the light of my theory xy and its relationship to the morale of the managers of the junior high school as the study population consisted of directors of junior high school in the city of Baghdad of six directorates education for the academic year 2013-2014 AD The number of managers (211) as director, and amounted to a sample Search of (150) director and director of the research community overall rate (71%) and represent this community fully representative sample, two tools were used in the study: the first measure of educational leadership in the light of my theory xy and the second tool to gauge morale.

Results concluded that the

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Publication Date
Thu Oct 25 2018
Journal Name
وقائع مؤتمر
تطبيقات انماط قيادة التعقيد في المؤسسات المستندة على المعرفة (التعليم العالي انموذجاً)
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Publication Date
Sun Jul 03 2005
Journal Name
Political Sciences Journal
عرض رسائل واطاريح (اثر التواجد العسكري الامريكي على النظام السياسي في العراق)
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اثر التواجد العسكري الامريكي على النظام السياسي في العراق

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Publication Date
Sun Mar 30 2025
Journal Name
مجلة كلية التربية الأساسية للعلوم التربوية والإنسانية
سمات الشخصية المفضلة لدى معلمي ومعلمات التربية الخاصة في العراق (دراسة عاملية)
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يستهدف البحث الحالي التعرف إلى 1 .بناء مقياس سمات الشخصية المفضلة لدى معلمي ومعلمات التربية الخاصة في العراق من وجهة نظر ذوي اإلختصاص والعاملين في هذا المجال. 2 .مستوى توافر سمات الشخصية المفضلة لدى معلمي ومعلمات التربية الخاصة في العراق من وجهة نظر ذوي اإلختصاص والعاملين في هذا المجال. 3 .داللة الفروق اإلحصائية في سمات الشخصية المفضلة لدى معلمي ومعلمات التربية الخاصة ً في الع ارق من وجهة نظر ذوي اإلختصاص والعا

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Publication Date
Thu Jun 30 2022
Journal Name
Journal Of Economics And Administrative Sciences
The Impact of Governance Mechanisms on the Accounting Disclosure of the Sustainable Development of Iraqi Economic Units
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The research aims to demonstrate the impact of governance mechanisms on the quality of financial reports in the light of the accounting disclosure for sustainable development represented in (accounting disclosure for economic development, accounting disclosure for environmental development, and accounting disclosure for social development) in a sample of banks listed in the Iraq Stock Exchange.

Governance mechanisms were measured by evaluating and analyzing the mechanisms in banks for the research sample consisting of (15) banks, based on the governance guide issued by the Central Bank, as well as the banks’ financial reports for the years 2016 -2018, and the dimensions of accounting disclosure for sust

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Publication Date
Fri Jan 04 2013
Journal Name
المجلة السياسية والدولية
عوامل تكوين الرأي العام وتأثيره في السياسه الخارجيه المصريه بعد عملية التغيير
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Publication Date
Tue Aug 20 2019
Journal Name
Political Sciences Journal
Means of the right to self - determination actions and patterns of its practices under the contemporary international development
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Abstract The means of self-determination have their peaceful and non-peaceful dimensions and are united(peaceful and non-peaceful) by international consensus adopted by international conventions and instruments. This has given it various dimensions at the applied level, especially in the light of the contemporary international developments witnessed by the world represented by a number of complete and incomplete implementation models that have nothing to do with the theory of truth Self-determination associated with the liberation of peoples from colonial domination or the liberation of oppressed nationalities

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Publication Date
Fri Feb 08 2019
Journal Name
Journal Of The College Of Education For Women
"حركة نیاغارا" في الولایات المتحدة الامریكیة: مقدماتھا ، نشأتھا، ١٩١٠- وعوامل انھیارھا ١٨٩
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The Negro minority in the United States is associated with social injustice,
political deprivation, and economic oppresion. Its members felt that they are
second-class citizens, and that the acceptance of such status will lead to the
continual oppresion of the Whites upon them. As a result, the educated community
adopted a process to put a framework to their opposition to the former's injustice.
This organised framework is exemplified in the "Niagara Movement," which is
regarded as the first national organisation for Negros. The topic of this study is
chosen due to its historical and political significance.
The study consists of an introduction and five sections. The first section
addresses the preliminaries an

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Publication Date
Sun Oct 14 2018
Journal Name
Arab Science Heritage Journal
الاجراءات الإجراءات الإدارية والقانونية وسبل معالجتها لآزمة الأراضي في بغداد 1932-1938
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شكلت السيطرة العثمانية على العراق  حقبة تاريخية مهمة ، حيث وضعت فيها ركائز عدد كبير من الأنظمة الأدارية  فغدت  الأساس للتنظيمات  فيما بعد ومنها  الإجراءات الإدارية والقانونية وسبل معالجتها لآزمة الأراضي في بغداد1938-1932.

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Publication Date
Tue Oct 08 2002
Journal Name
Iraqi Journal Of Laser
Visible Enhanced Photodetector Made by Spray Pyrolysis
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Barium–doped TiO2 / n-Si photodetector was fabricated by spray pyrolysis exhibited visible enhancement responsivity profile with peak response at 600 nm flat response between 650 and 900 nm. The quantum efficiency was 30% and specific detectivity was 5x1012 W-1Hz1/2cm at peak response. The GaAlAs laser diode was used to estimate the rise time of the detector.

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