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Experimental Study on the Effect of Insertion of Copper Lessing Rings in Phase Change Material (PCM) on the Performance of Thermal Energy Storage Unit
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Abstract

One of the most suitable materials to be used in latent heat thermal energy storage system (LHTES) are Phase change materials, but a problem of slow melting and solidification processes made many researchers focusing on how to improve their thermal properties. This experimental work concerned with the enhancing of thermal conductivity of phase change material. The enhancing method was by the addition of copper Lessing rings in phase change material (paraffin wax). The effect of diameter for the used rings was studied by using two different diameters (0.5 cm and 1cm). Also, three volumetric percentages of rings addition (3%, 6% and 10%) were tested for each diameter. The discharging process was done with four velocities for each case. The obtained results indicated that the maximum volumetric percentage gave a diminished time for melting and maximized the heat transfer in both PCM and air sides as compare with the case of no rings, but the effect of these rings had lower effect on the solidification time. In case of 1 cm rings diameter minimum time for melting was obtained for both 3% and 6% volumetric percentages as compared with the same percentages in case of 0.5 cm diameter rings, while the latter with 10% volumetric percentage overcomes the 1 cm diameter rings for the same previous percentage. Also it can be seen that the minimum velocity (v=1m/s) gave the utmost outlet temperature and with the maximum one (v=3m/s), the minimum solidification time achieved.

Keyword: Thermal energy storage systems, Latent heat storage, Phase change materials, Heat transfer enhancement.

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Publication Date
Mon Jul 26 2021
Journal Name
جامعة بغداد/ كلية التربية للعلوم الصرفة - ابن الهيثم
مهارات التفكير الجبري المتضمنة في كتاب الرياضيات للصف الثالث المتوسط وامتلاك الطلبة لها
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Publication Date
Sun Jan 01 2017
Journal Name
Journal Of The College Of Languages (jcl)
« L'agressivité de la parole et de l'acte » dans Haute Surveillance et Les Bonnes de Jean Genet
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Sommaire

                      La question de la violence et de l'agressivité  porte une importance remarquable dans l’esprit de Jean Genet qui estime le crime   en le considérant comme beau. Il lui donne une valeur suprême. Il le glorifie avec ses personnages criminels.   Le langage théâtral genétien est violent qui conduit à la fin à l’acte agressif, le crime et la mort. Ce théâtre qui aborde la condition humaine retrace sur la scène le chemin tragique de l’homme moderne.               

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Publication Date
Sun Jan 03 2016
Journal Name
Journal Of Educational And Psychological Researches
إنتاج المعرفة واكتسابها لدى طلبة كليات العلوم التربوية في بعض الجامعات الأردنية الرسمية
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This research attempts to propose production and acquisition of scientific knowledge among the students of educational science faculties in some universities Governmental Jordanian (Yarmouk, Jordan, Muta). In addition to sources of educational gained in some of the Governmental Jordanian universities (Yarmouk, Jordan, Muta), and to propose the necessary socio-cultural dimensions of knowledge acquisition and production, using developmental screening method, which is represented in the study design tool (questionnaire), which consisted of 4 scales, scale: The reality of the acquisition of knowledge / reality of the production of knowledge / social dimensions of knowledge acquisition and production / cultural dimensions of knowl

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Publication Date
Mon Jan 02 2017
Journal Name
Journal Of Educational And Psychological Researches
موقف القيادات الجامعية في الأردن من إلغاء وزارة التعليم العالي مدخلا لتنمية المجتمع
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  • The study aimed to identify the position of the university leaders from the proposed abolition of the Ministry of Higher Education in Jordan as un approach for the development of society, the study relied descriptive method survey with the assistance consists of (33) items, and check validity and reliability of the instrument, and was applied to a sample of university leaders, (57) a leading university presidents and their assistants and deans and their assistants, and after processing the data bagful statistical( spss) overall results showed the to arithmetic average of (2.74) and the degree of medium and this means that most respondents moderately support the abolition of the ministry, the most prominent item that makes
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Publication Date
Mon Sep 26 2022
Journal Name
جامعة بغداد/ كلية التربية للعلوم الصرفة - ابن الهيثم
مهارات التفكير المعرفي وعلاقته باليقظة العقلية لدى طلبة أقسام الرياضيات في كليات التربية
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Publication Date
Mon Nov 12 2018
Journal Name
Arab Science Heritage Journal
المادة المادة السابعة في معاهدة باريس لعام 1856 وموقف الدول الأوربية الكبرى منها
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            The issue of the survival of the Ottoman Empire during the nineteenth century, a controversial topic in European diplomacy, was what was called the "Eastern Question" containing the fate of this country and its regions sprawling one of the hottest topics in the diplomatic major European powers of that century

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Publication Date
Mon Jan 01 2018
Journal Name
مجلة الآداب والعلوم الإنسانیة
الأداء الاعلامي بين الرضا الوظيفي و المهنية للمرأة الاعلامية في القنوات الفضائية العراقية
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ﺔﻴﻋﺍﺫﻹﺍ ﺕﺎﻴﻨﻘﺘﻟﺍ ﻡﺍﺪﺨﺘﺳﺍ ﰲ ﲑﺒﻛ ﺭﻮﻄﺗ ﻦﻣ ﻝﺎﺼﺗﻻﺍ ﺮﺼﻋ ﻩﺪﻬﺷ ﻱﺬﻟﺍ ﺖﻗﻮﻟﺍ ﰲ ﺔﻴﻧﻮﻳﺰﻔﻠﺘﻟﺍﻭ ﺍ ﺢﺴﻓ ﰲ ﻢﻬﺳﺃ ﺕﺎﻄﶈﺍ ﺀﺍﻮﺳ ﺔﻴﻧﻮﻳﺰﻔﻠﺘﻟﺍ ﺕﺍﻮﻨﻘﻟﺍ ﺚﺒﻟ ﻊﺳﺍﻮﻟﺍ ﻝﺎ ( ﺔﻴﺿﺭﻷﺍ ﺔﻴﻠﺑﺎﻜﻟﺍ ﻭﺃ ﺔﻴﺋﺎﻀﻔﻟﺍ ﻭﺃ ( ﱵﻟﺍ ﺔﺻﺎﳋﺍ ﺔﻴﺋﺎﻀﻔﻟﺍ ﺕﺍﻮﻨﻘﻟﺍ ﻦﻣ ﺪﻳﺪﻌﻟﺍ ﺭﻮﻬﻇ ﰲ ﺎﻀﻳﺃ ﺪﻋﺎﺳ ﺎﳑﻭ ، ﺕﺎﻴﺋﺎﻀﻔﻟﺍ ﺭﻮﻬﻇ ﻚﻟﺫ ﻞﺒﻗ ﺩﺎﺳ ﻥﺃ ﺪﻌﺑ ﺔﻴﻣﻮﻜﺣ ﲑﻏ ﺕﺎﻴﻌﲨ ﻭ

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Publication Date
Mon Sep 30 2024
Journal Name
نسق
تحليل اثر برامج تدريبية في مجال تطوير المهارات الاساسية للاعبات كرة القدم للنساء
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Publication Date
Sun Jul 02 2017
Journal Name
Journal Of Educational And Psychological Researches
اثـر انمــوذج 4EX2 في تعديل الفهم الخاطئ للمفاهيم الكيميائية لطلاب الصف الثالث المتوسط
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The Current research aims to identify ( The effects of 4EX2 Model in Misconception of Chemical concepts and Higher Order Thinking for the Students of the Third grade average ) , To verify the objective of this research , the researchers added nul hypothesis following : There is no difference is statistically significant at the level of ( 0.05 ) between the average scores of students who studied 4EX2 Model and the average students who studied by using the Misconception of Chemical concepts and Higher Order Thinking test. The research was conducted on a sample of the average Third grade students in a Baghdad secretary for boys affiliated to the General Directorate for Educational in Baghdad Al – karkh 3 and for academic year ( 2015 – 2

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Publication Date
Mon Jun 01 2020
Journal Name
مجلة جامعة الانبار لللعلوم القانونية والسياسية
تقويم قواعد إدارة الشركات في ضوء قانون الشركات العراقي رقم 21 لسنة 1997،
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تقويم قواعد إدارة الشركات في ضوء قانون الشركات العراقي رقم 21 لسنة 1997،