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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
Sun Jan 01 2012
Journal Name
Journal Of Educational And Psychological Researches
الصعوبات التي تواجه البحث العلمي في جامعة بغداد من وجهة نظر التدريسيين
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The problem of the study lies in the need for standing on the justifications, reasons and difficulties that face the scientific research matter at Baghdad university. The importance of this study lies in the fact of being scientific research one of the most important methods in developing the teaching members performance efficiency which contributes in teachers contact with the modern developments that emerge in work. That matter which reflexe on the educational process and the scientific production in their universities.

And the research goal is summarized in identifying the difficulties that is facing the scientific research at Baghdad university from the point of view of the lecturers, and also to ide

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Publication Date
Sat Dec 29 2018
Journal Name
Journal Of Planner And Development
اهمية تطبيق المعايير التخطيطية للفضاءات المفتوحة والخضراء ودورها في التخطيط الافضل للمدن
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Publication Date
Fri Jan 04 2019
Journal Name
Journal Of Planner And Development
نمذجة توزيع المدارس الابتدائية في مدينة الفلوجة باستخدام نظم المعلومات الجغرافية G.I.S
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Publication Date
Sat Oct 27 2018
Journal Name
Journal Of Planner And Development
دور سهولة الوصول في تعزيز ابعاد التنمية الحضرية شارع الرشيد حالة دراسية
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Publication Date
Mon Oct 15 2018
Journal Name
Arab Science Heritage Journal
نحو نظام نحو نظام لغوي عربي متوازن في المساواة بين الرجل والمرأة
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We must live in an era dominated by the call for equality between men and women, in which the voices of advocates of gender integration were heard. After women opened their doors to compete with their brother, Knowledge, and culture in the various forms of life, language as a science of the time and knowledge of the other had to match this reality and express the most accurate expression of this task

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Publication Date
Tue Dec 31 2013
Journal Name
Journal Of The College Of Languages
إيقــاع النفـــس الشـــاعـرة في شعر الشاعر الصّقلي علي بن عبد الرحمن البلـَّنوبي
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درست الباحثة البنية الإيقاعية عند الشاعر الصقلي

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Publication Date
Fri Apr 12 2019
Journal Name
Journal Of Economics And Administrative Sciences
الهبة الديموغرافية وإستثمارها في التنمية الإقتصادية رؤية واقعية للعراق بعد عام 2003
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Abstract

   The relationship between population and development is one of the most interrelated relations in contemporary societies. Therefore it is important focus on the demographic aspects of the population and its integration with developmental aspects, because the population is the makers of development and responsible for its success. The population composition and their qualitative composition are important factors in development. This change in age rate is because of demographic operations which lasted for long time. The change we are talking about is happing currently in Arab cou

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Crossref
Publication Date
Tue Apr 01 2008
Journal Name
Journal Of Educational And Psychological Researches
الطفولة في العراق بين جهود التنمية وتحديـــات الوضــــع الراهــن قســم الخدمـة الاجتماعيـة
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      اهتمت المجتمعات العالمية في الآونة الأخير بفئة الأطفال ، ورعاية الطفولة وذلك لما لها من أهمية كبيرة في مستقبل المجتمع ، وتنميتة وتقدمه . لأنها يعتمد عليها في تقدم وتطور المجتمع فـي جميع المجالات الاقتصادية والاجتماعية والثقافية . ومن هنا ارتبطت الطفولة بالحياة برباط عضوي فالأطفال براعم الحياة ومع هذه البراعم تستمر الحياة لذلك اهتمت دول العالم بوضع البرامج وعقد المؤتمرات من اجل النهوض

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Publication Date
Mon Oct 15 2018
Journal Name
Arab Science Heritage Journal
رواد رواد علم الفلك في العصر العباسي أولاد موسى بن شاكر أنموذجاً
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Is astronomy in the Abbasid era one of the sciences that Muslims developed at that time? The restriction of students at the hands of a large number of students, which increased the development and increase the value of monitoring mechanisms and their outstanding efforts in support and development of the Arab civilization of Islam

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Publication Date
Sun Apr 03 2016
Journal Name
Journal Of Educational And Psychological Researches
تطوير الكفايات التدريسية للأستاذ الجامعي في ضوء معايير دورة ديمنغ للجودة (PCDA)
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The problem of the present study lies in the challenges that college education especially that concerns the quality of college teachers performance and developing the level of educational process quality.

This study aimed at constructing a vision the researchers have constructed depending on the standards of performance quality represented by Deming's quality course. The researchers presented a number of skills that should be existed in the performance of college teacher through using the analytic and constructing approach in imagining this drawing to develop performance.

The study results represented by a number of efficiencies that college  teachers shoul

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