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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 17 2021
Journal Name
Arab Science Heritage Journal
المبادرة في عهد الامام علي بن ابي طالب (عليه السلام )
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    Thank Allah and prayers on the Prophet Mohammed the man of truth and honest (PBUH).

The initiations in the role of Imam Ali (PBUH) is considered among the important initiations in Islamic thinking .It is considered the way to invest the conditions that the individual in the light of it can reach to make gains and achievements

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Publication Date
Fri Jan 04 2019
Journal Name
Journal Of Planner And Development
اللامركزية أسلوب تنموي إقليمي لمعالجة مشاكل التحضر المفرط في العراق
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Publication Date
Sun Jan 03 2016
Journal Name
Journal Of Educational And Psychological Researches
تقويم كتابي الفيزياء للمرحلة الإعدادية في ضوء المستحدثات العلمية المعاصرة
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The present study aimed to measure the calendar estimates for my book Physics of the preparatory phase (fourth and fifth preparatory) has been a research sample consisted of 32 teachers and a school for 36 schools from both sides of the Rusafa and Karkh first To achieve the objectives Find promised researcher tool for measuring the calendar estimates for my book Physics of the preparatory phase in accordance with the contemporary scientific innovations as formed tool from 5 innovations built on the basis of which the paragraphs which formed the final version of the 21 paragraph manual are not substitutes to answer yes -No Your has been used Baha percentages to reach the results may reach current research conclusion which is defic

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Publication Date
Wed Dec 01 2010
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
إنشاء جائزة عربية للجودة في قطاع التعليم العالي: رؤيــة عراقيــة
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  IF we called twentieth century, the century of productivity and information revolution, the suitable address for twenty-first century is (( The quality century )) .

The research aims to initiate Arabic prize for quality to apply concepts and strategies of total quality management at Higher education sector, which is a vital sector and it may be the most importance sector because it provide efficient human manpower working at all other sectors.

The suggested prize take in consideration the specialty of this sector, and when we apply perspectives of this prize this will promote Arabic universities performance as well as the quality of graduates.

The importance of this research due to the necessity of this pri

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Publication Date
Sun Oct 01 2017
Journal Name
Journal Of Educational And Psychological Researches
أثر انموذج دانيال في الدافعية المعرفية لطلاب الصف الثالث المتوسط
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The Current research aims to identify ( The effects of Daniel Model in Cognitive Motivation 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 Daniel Model and the average students who studied by using traditional method in Cognitive Motivation scale. The research was conducted on a sample of the average Third grade students in a medium Al – sadiq Al – Ameen secretary for boys affiliated to the General Directorate for Educational in Baghdad Al – rusafa 2 and for academic year ( 2014 – 2015 ) , the researchers adopted

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Publication Date
Thu Jan 01 2015
Journal Name
دار الضياء للطباعة والتصميم
SPSS النظرية والتطبيق في Exploratory Factor Analysis التحليل العاملي الاستكشافي
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يعد التحليل العاملي Factor Analysis أحد الأساليب الإحصائية المهمة والتي يصعب تنفيذها يدويا ً أو بالألات الحاسبة الصغيرة لذا لاقى الباحثين صعوبة في إستخدامه في البداية بل كان من المستحيل القيام به ، لذا فالمؤلف قد تناول التحيلي العاملي الاستكشافي لكونه إسلوب إحصائي يستخدم في تحليل البيانات ويتطلب شروطا ً لأستخدامه ودقة في مراعاة هذه الشروط ويتطلب أيضا ً معايير يجب أن يتأكد الباحث من توافرها في البيانات وهذا ما تم ت

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Publication Date
Fri Dec 01 2017
Journal Name
الأستاذ
معايير التنور التقني المتضمنة في محتوى كتابي الحاسوب للمرحلة الاعدادية
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هدف البحث معرفة نسبة تضمين معايير التنور التقني في محتوى كتابي الحاسوب للمرحلة الإعدادية في العراق عن طريق الإجابة عن السؤال الآتي: ما نسبة توافر معايير التنور التقني في محتوى كتابي الحاسوب المقرران على طلبة المرحلة الاعدادية بفرعيها ( العلمي والادبي ) المعتمدان من وزارة التربية العراقية/ المديرية العامة للمناهج في العام الدراسي (2016-2017 )؟ وتم اعتماد المنهج الوصفي التحليلي، وتكون مجتمع البحث وعينته من محتو

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Publication Date
Sun Mar 10 2019
Journal Name
مجلة علوم الانسان والمجتمع
قياس الشخصية الاستغلالية لدى طلبة الجامعة في ضوء بعض المتغيرات
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دف البحث إلى قياس الشخصية الاستغلالية لدى طلبة الجامعة على وفق متغيرات: الجنس والتخصص والمرحلة الدراسية ، تكونت عينة البحث من (200) طالباً وطالبة من طلبة جامعة بغداد، قامت الباحثة ببناء مقياس الشخصية الاستغلالية وبعد تطبيقه على العينة وتحليل البيانات بالوسائل الاحصائية المناسبة ، اظهرت نتائج البحث عن شيوع الشخصية الاستغلالية لدى الطلبة ، وان الذكور لديهم شخصية استغلالية اكثر موازنة بالاناث كما اظهرت نتائج ا

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Publication Date
Wed May 11 2022
Journal Name
Journal Of The College Of Law/al-nahrain University
التزام الملاك بنفقات صيانة الاجزاء المشتركة وأعبائها في الاسكان العمودي.
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The phenomenon of multi-class construction and landlords has increased in Iraq, and this is not justified except because of the change in the economic and social conditions in it, because like any social system interacts with what happens in society, whether it is positive or negative, and since the vertical housing system contains common parts and these parts need to Maintenance and preservation, and in order to continue to perform the construction and other parts in an effective and regular manner for a long period of time and with appropriate efficiency, it must be maintained, and maintenance is one of the most important and difficult problems facing the partners. It is recognized that it is not possible to understand these practical dif

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Publication Date
Thu Feb 07 2019
Journal Name
Journal Of The College Of Education For Women
اثر البرنامج القصصي في تنمیة الثقة بالنفس لدى طفل الروضة
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The early childhood is a dangerous period for the development of children
in their present and future life . It is important to design programs for the preschool
period .
These programs are relatd to the childs Personality and its integration .
The most effective stories and attractive programs for the child is the objective
stories which can develop his self-canfidence . Therefore the kindergarten
should participate in developing the childs personality and experience
because it is the most effective institute in the childs life .
The present study aims at finding out the effect of the narrative program in
the kindergartens . This has been done by investigating the truth of a number
of hypotheses to measure

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