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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 Dec 04 2025
Journal Name
Journal Of The College Of Basic Education
Objective trends of university theses and dissertations of the College of Political Science at the University of Baghdad: an analytical study
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The research sought to identify the objective trends of postgraduate students at the College of Political Science - University of Baghdad for the period from 2000-2012 through the objective trends of university theses and dissertations and what are the most and least studied topics, with a re-adjustment of previously studied topics towards topics that serve issues of concern to society and avoiding topics that have been studied a lot to avoid repetition. The research came out with the following results, the most prominent of which are: The total number of what was accomplished in this college is 401 theses and dissertations, and the dissertations had the largest share of them, as their percentage reached 69%, with 275 theses compared to 126

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Publication Date
Wed May 01 2019
Journal Name
المجلة العربية للعلوم التربوية والنفسية
الصحة النفسية وعلاقتها بتقدير الذات لدى عينة من أطفال الشوارع في مدينة بغداد
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هدف البحث إلى الکشف عن العلاقة بين الصحة النفسية وتقدير الذات لدى أطفال الشوارع، تألفت عينة البحث من (50) طفلاَ وطفلة، وتم تطبيق مقياسا البحث - مقياس الصحة النفسية ومقياس تقدير الذات وهما (من إعداد الباحثة)، وقد اسفرت نتائج البحث عن إن أطفال الشوارع اظهروا مستوى منخفض في الصحة النفسية وکذلک الحال بالنسبة لتقدير الذات، فضلاً عن وجود علاقة ارتباطية موجبة دالة إحصائيا بين الصحة النفسية وتقدير الذات. وفي ضوء نتائج

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Publication Date
Mon Nov 12 2018
Journal Name
Arab Science Heritage Journal
المساواة المساواة بين الرجل والمرأة في ضوء القرآن الكريم دراسة تفسيرية ـ موضوعية
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 It was the most important weapons that were used during the long cultural war standing against Islam, it is interesting colonists Muslim women special attention, and directed to lure women rebellion against religion, and go out on their own teachings in this religion,

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Publication Date
Thu Apr 04 2019
Journal Name
مجلة كلية التربية
جدلية الحركة والسكون والحرف والمقطع رصد وتأصيل لمفهوم المقطع في إيقاع الشعر العربي
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Publication Date
Thu Dec 04 2025
Journal Name
Lark Journal For Philosophy , Linguistics And Social Sciences
صورة المرأة العربية في المسرحية العبرية الحديثة – مسرحية " عبير " للكاتبة حاجيت يعاري انموذجا
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Publication Date
Tue Dec 22 2020
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
قياس مخاطر الائتمان المصرفي ودورها في تحقيق الافصاح المحاسبي بالمصارف العراقية: أطار مقترح
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Bank credit  function plays an important role in realizing the targets of commercial banks , so that the credit dominate the most of assets for these banks , also the credit contribute by bigger share of operational income for these banks .Bank credit faces

high challenge that it is bank credit risks which hinder realizing goals of bank credit . the researcher discover that in spite of the international accounting standards assured that it  is necessary to disclose about risks related assets, which include bank credit, and also disclosure about fund which specified to face probable loss for this credit , but the recent disclosure about bank credit risks and its provision indicate that it faces sever defect which hinder

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Publication Date
Thu Dec 13 2018
Journal Name
Arab Science Heritage Journal
وسائل وسائل الاتصالات السريعة في حروب العرب المسلمين حتى منتصف القرن الرابع الهجري
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          This Study is concerned with The Fast communications in the wars of arab moslims until the middle of fourth century . it pointed to many communications for that , Like using the fast horses , and carrier pigeon , Almanader (Almanawin) wich used to tell for long distances , and drums , trumpets…

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Publication Date
Fri Feb 08 2019
Journal Name
Journal Of The College Of Education For Women
المتغیرات الداخلیة والخارجیة المؤثرة على النظام السیاسي في باكستان ٢٠٠٩ - للمدة من ١٩٩
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The research(the internal and external factors affecting the political system in
PAKISTAN) involves a series of effects interact both internally and external to affect the
stsbility of the political system.
Intrernally there are a lot of powers affecting the political map of PAKISTAN such as
military institution, political parties, judgement, religious schools……etc.of internal
factors, which represent one of the most important pressure points on the system.
Externally one of the most important external factors which affect internal stability is
Pakistani allision to USA in antiterrorism war. The Pakistani military institution was
involved in the war against Pakistani tribes leading to unstable security in Paki

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Publication Date
Sun Sep 22 2019
Journal Name
Baghdad Science Journal
The Antibacterial, Antiheamolytic, and Antioxidant Activities of Laurus nobilis and Alhagi maurorum Native to Iraq.
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Ethanolic crude extracts of leaves from Laurus nobilis and Alhagi maurorumfor were screened for alkaloids, saponins, tannins, anthraquinones, steroids, flavonoids, glycosides, and glucosides contents. Biochemical activities, including antibacterial activity, antioxidant, and antihemolytic activity, were investigated. Antibacterial activity against Three types of pathogenic bacteria was detected by disc diffusion analysis and characterized by zone of inhibition (ZOI). Antioxidant properties were determined by a diphenyl-1- picrylhydrazyl (DPPH) method. Results revealed that the inhibitory activity of the plants against G+ve and G-ve bacteria were different, where the greatest ZOI  of  Alhagi maurorum a

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Publication Date
Sat Jun 01 2024
Journal Name
مجلة الدراسات المستدامة
المسؤولية المدنية الناشئة عن الاخلال بالالتزام بضمان سلامة الاشخاص في عقد التحاليل الطبية
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