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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
Fri Jan 01 2010
Journal Name
مجلة العلوم التربوية والنفسية
أثر استراتيجية تعلم الاقران في تصحيح الفهم الخاطئ للمفاهيم الجغرافية لدى طالبات الصف الاول المتوسط
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يرمي هذا البحث الى تعرف اثر استراتيجية تعليم الاقران في تصحيح الفهم الخاطئ للمفاهيم الجغرافية لدى طالبات الصف الاول متوسط

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Publication Date
Wed Jun 29 2022
Journal Name
College Of Islamic Sciences
term of the first difference between the Imam of the Two Holy Mosques, Imam Taj Al-Din al-Subki and its impact on the doctrine of Al-Shafeiyah
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Praise be to Allah, the Lord of the Worlds, the best prayer and the best prayer, on our master Muhammad, and on his pure God, and his companions and the faithful, and who followed them by charity to the day of religion. This relationship between emphasis, is a sincere, and this harmony, such as the relationship between water, and the green, but it is good, but, with greenery, it is better, and as well as alone, is a beautiful view, but the most beautiful, with the most beautiful. From here he was starting on myself in writing the fundamentalist research of jurisprudence, to show the depth of this interconnection. The doctrine as a new term, then the taj al-Din al-Suobki came after three centuries, and a

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Publication Date
Sun Apr 02 2017
Journal Name
Journal Of Educational And Psychological Researches
بعض الاضطرابات السلوكية والانفعالية والانفعالية وعلاقتها بالاستعمال المفرط للألعاب الالكترونية لدى التلاميذ في المرحلة الابتدائي
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سعى البحث الحالي الى التعرف على بعض الاضطرابات السلوكية والانفعالية وعلاقتها بالاستعمال المفرط للالعاب الالكترونية لدى تلاميذ المرحلة الابتدائية, إذ يواجه التلاميذ مشكلات سلوكية عديدة ،تظهر من خلال تعاملهم مع اقرانهم في البيت او في المدرسة والتي قد تتطور عند بعضهم وتتحول الى اضطرابات نفسية،مما يؤدي بهم الى ضعف التعلم وسوء التوافق في حياتهم المدرسية ويصبحون عُرضة للا صابة بالامراض النفسية ،إذا لم يتم تشخ

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Publication Date
Fri Dec 30 2022
Journal Name
Journal Of The College Of Education For Women
The Effect of Cognitive Strategies on Iraqi EFL College Students’ Writing Anxiety
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Writing in English language demands both mental skills and a suitable level of language proficiency. Some studies showed that writing anxiety has an impact on the acquisition of language learning. This study; however, teaches the cognitive strategies (PLAY & WRITE) as a writing strategy, so as to decrease students’ use of it when experiencing writing anxiety at the academic writing level. The sample has been (100) second-stage Department of English learners at the College of Education (Ibn –Rushd), in the University of Baghdad-Iraq. They have been randomly selected and divided into experimental and control groups; (50) students in each group. To achieve the objective of the study, SLWAI questionnaire has been distributed to the e

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Publication Date
Wed Jun 01 2011
Journal Name
Political Sciences Journal
أسس بناء الجهاز الاداري الكفء : قراءة في عهد الامام علي بن ابي طالب لمالك الأشتر
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أسس بناء الجهاز الاداري الكفء : قراءة في عهد الامام علي بن ابي طالب لمالك الأشتر

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Publication Date
Sat Dec 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Reflection of innovative marketing skills on the broad recommendation Survey Research at Asia Telecom- Iraq
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The research aims at clarifying the relationship between innovative marketing skills and broad recommendation as a vital and important issue for organizations in general and service organizations in particular to demonstrate how innovative marketing skills contribute to broad adoption and to determine the relationship between interdependence and the impact of innovative marketing skills on the broad recommendation. Some questions are posed by the research problem. Is there a clear awareness among individuals in the company about the concept of marketing marketing skills and how do innovative marketing skills affect the broad recommendation of the surveyed company? How innovative marketing skills relate to the broad recommendation

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Publication Date
Wed Jun 14 2023
Journal Name
Al-academy
The effect of dramatizing characters within the social subject of the basic education stage on student achievement
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The researcher used the experimental approach due to its suitability and the nature of the research problem. The research community was represented by the eighth-grade students in the Rozak Elementary Mixed School affiliated with the General Directorate of Education in Erbil / the center, for the academic year (2021-2022), the number is (96) students, and the research sample consisted of (63) male and female students, with (31) in the experimental group, and (32) in the control group, and (11) students were excluded by (5) students from the experimental group, and (6) students from the control group, as the excluded, are students who failed and were absent from the lessons, and accordingly, the research sample became composed of (52) mal

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Publication Date
Wed Dec 27 2017
Journal Name
Al-khwarizmi Engineering Journal
The Effect of Oil and Filer Contents on the Porosity of Lead Acid Battery Separators Produced From Polyethylene
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                In this investigation a high density polyethylene (HDPE) was used as a substitute to polyvinylchloride in the production of lead acid battery separators. This has been achieved by preparing mixtures of different percentages of the feed materials which include a high density polyethylene (HDPE) locally produced, filler materials such as silica and oils such as dioctylphthalate (DOP) or paraffin which were added to the mixture to improve the final properties of the separator. The materials were compounded by two roll-mills under the same conditions. The following parameters are involved:           &nb

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Publication Date
Tue Dec 27 2022
Journal Name
Journal Of The College Of Basic Education
فاعلية أنموذج (سكمب المعدل) في الأصالة الرياضية واتجاه طلاب الصف السادس العلمي نحو البرهان الرياضي
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هدف البحث الحالي التعرف على فاعلية انموذج سكمب المعدل في الأصالة الرياضية واتجاه طلاب الصف السادس العلمي نحو البرهان الرياضي ، تَمَّ الاستعانة بالتصميم التجريبي ذي الاختبار البعدي والضبط الجزئي لمجوعتين متكافئتين (تجريبية وضابطة) ، تكونت عينة البحث من (55) طالباً من طلاب الصف السادس العلمي في ثانوية ابن الهيثم للبنين الواقعة في مركز محافظة القادسية ، جرى توزيع طلاب عينة البحث عشوائياً إلى مجموعتين إحداهما تج

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Publication Date
Thu Mar 30 2023
Journal Name
College Of Islamic Sciences
The effect of readings on the multiplicity of explanatory significance of a single Qur’anic word, a study through the interpretation of Ibn Attia al-Andalusi
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The study aimed to clarify the meanings learned and inferred from reading books، letters and messages in Surat Al-Qur’an. The inductive method، the analytical method، and the deductive method، One of the most prominent results of the research: that the multiplicity of Qur’anic readings produces a variety and expansion in the meaning that has a clear impact on the interpretation by clarifying the meaning of the verse.

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