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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
Sun Jan 03 2010
Journal Name
Journal Of Educational And Psychological Researches
اثر الاسئلة السابرة في تحصيل طلاب الصف الرابع العام لمادة التاريخ
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The importance of teaching methods and procedures comes from the nature and significance of the questions raised inside the classroom. That is, because questions, in fact, are the means of communication and interaction in the class situation. Therefore they are considered as indispensible elements in any teaching approach. Furthermore, it is noticeable that the majority of teachers fail in using them, for questions are often casted spontaneously and without pre-planning. Hence, a delay may occur in realizing the pre-set objectives, and let alone the dominance of stereotyped questions, especially when the teachers focus on a type of question which can be directly answered from the text-book.

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Publication Date
Sun Jul 01 2007
Journal Name
Political Sciences Journal
عرض رسائل (الموقف من التعددية الحزبية في الفكر السياسي الاسلامي المعاصر)
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عرض رسائل (الموقف من التعددية الحزبية في الفكر السياسي الاسلامي المعاصر)

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Publication Date
Thu Dec 08 2022
Journal Name
مجلة حمورابي
العقيدة العسكرية للمنظمات الارهابية الحرب اللامتماثلة في العراق عام 2014 انموذحا
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Publication Date
Sun Jul 02 2006
Journal Name
Political Sciences Journal
اثر بديع الزمان سعيد النورسي على الفكر الاسلامي المعاصر في تركيا
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اثر بديع الزمان سعيد النورسي على الفكر الاسلامي المعاصر في تركيا

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Publication Date
Wed May 18 2016
Journal Name
Al-academy
Aesthetic dimension to the formation of postmodern: إيهاب احمد عبد الرضا
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Find taught dimension aesthetic in the formation of post-modernism, which is one of the themes of aesthetics in the stream of postmodernism, is problematic because of the lack of provisions and fixed values reinforce the concept of beauty, and put done technical plastic in the circle of evaluation and judgment aesthetic, this research as an attempt to reveal the aesthetic concepts that can be drawn from artistic experiments in the formation of post-modernism, through the development of those concepts viable mainstream.
Search contains four chapters: the first chapter includes a general approach to the research, has been showcasing the research problem and the importance of research and goal of Search: detection dimension aesthetic in

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Publication Date
Wed Nov 28 2018
Journal Name
Arab Science Heritage Journal
جوانب جوانب من المعالجات البيئية والمناخية لعمائر الطين في الواحات الليبية
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This paper sheds light on aspects of environmental and climatic treatments in the groves mud existing in some Libyan oases. It reveals the architecture efforts and contributions to the adaptation of the construction and materials in order to organize the weather inside the building blocks to suit the nature of the human and his living in all seasons

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Publication Date
Mon Dec 28 2020
Journal Name
Journal Of The College Of Education For Women
Cognitive Implications of Usage-Based Approach: رغد فهمي اعجمي
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Tremendous efforts have been exerted to understand first language acquisition to facilitate second language learning. The problem lies in the difficulty of mastering English language and adapting a theory that helps in overcoming the difficulties facing students. This study aims to apply Thomasello's theory of language mastery through usage. It assumes that adults can learn faster than children and can learn the language separately, and far from academic education. Tomasello (2003) studied the stages of language acquisition for children, and developed his theory accordingly. Some studies, such as: (Ghalebi and Sadighi, 2015, Arvidsson, 2019; Munoz, 2019; Verspoor and Hong, 2013) used this theory when examining language acquisition. Thus,

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Publication Date
Tue Nov 06 2018
Journal Name
Arab Science Heritage Journal
العامل العامل الاقتصادي وأثره في نشوء المدن الإسلامية وتطورها ( بخارى ) أنموذجاً
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After atour-For quite somtime,in the field of research and investingation on the economic aspects and the impact of her money is mportantin the evolution and emegece of the Islamic countres,especially including especially Morkhana him specimer nigh borhood the countries of the mashreq al islami,searhout,among other things summarilesas

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Publication Date
Sun Jan 01 2017
Journal Name
المجلة القانونية العلمية المحكمة
الدور القانوني للحوافز الضريبية في تحقيق التراكم الراسمالي(العراق ومصر انموذجا)
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Publication Date
Tue Dec 27 2022
Journal Name
مجلة العلوم النفسية
متطلبات تطبيق الحوكمة في الجامعات العراقية جامعة بغداد - جامعة الانبار انموذجا
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يعد النظام التعليمي لاي بلد انعكاسا للمستوى الثقافي والحضاري للمجتمع وعادة ما يحدد هذا النظام ويوجه من قبل التنظيمات السياسية والاقتصادية والاجتماعية في المجتمع كونها تعتمد علية في تحقيق اهدافها ,وصبحت الجامعة اليوم تمثل عمد النظام التربوي والتعليمي بما تمتلكه من كفاءات وقد ا رت وامكانيات بشرية ومادية تستطيع من خلالها رفد المجتمع بما يحتاجة من قد ا رت بشرية متعلمة في كافة الاختصاصات ومناحي الحياة لادامة ال

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