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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
Fri Jun 01 2012
Journal Name
Journal Of The College Of Languages (jcl)
Функция и значение союзов и союзных слов в русском и арабском языках Тахсин Раззак Азиз
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Одной из трудностей, вызывающих искажение смысла предложения, при переводе и понимании любых текстов зачастую является неправильное понимание функций и значений: союзов и союзных слов или замена одного значения другим. Это объясняется прежде всего тем, что при чтении основное внимание сосредоточено на переводе главных частей речи, на их многофункциональности и многозначности и упускаются из вида втор

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Publication Date
Sun Jul 07 2013
Journal Name
Journal Of Educational And Psychological Researches
العولمة الثقافية في القيم التربوية لطالبات قسم رياض الاطفال
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Seemed reflections of cultural globalization are clear on the values of communities those values that preserve each community privacy, so that became members of these communities lack the ability to distinguish clearly between what is right and what is wrong and adoption of ideas and values imported from abroad, regardless of whether positive or negative. The aim of the research was to: - 1 - Detection of cultural globalization in the educational values for students kindergarten section. 2 - To identify the most prominent educational values (social, scientific, aesthetic, moral and spiritual) globalized culture. The current Aqtsralbges on: - Department of kindergarten students to study in the morning College for Girls, Baghdad University

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Publication Date
Thu Dec 13 2018
Journal Name
Arab Science Heritage Journal
ال أل العاقولي ودورهم العلمي في الحضارة العربية الإسلامية
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The research includes a bout IL- IQulle , and their role in scientific of the Islamic – Arabic civilization , for Dr. Khlood M.Namma the proff in the collage of education for woman , Baghdad university , History department .

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Publication Date
Sun Jul 03 2005
Journal Name
Political Sciences Journal
تحديات العولمة للهوية العربية ودور الجامعات العربية في مواجهتها
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تحديات العولمة للهوية العربية و دور الجامعات العربية في مواجهتها

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Publication Date
Sun Apr 06 2014
Journal Name
Journal Of Educational And Psychological Researches
مدى تقبل الأطفال لبيئتهم الصفية في الرياض الحكومية والأهلية
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The research aimed at measuring the degree to which the accept their class environment in governmental & civil Kindergartens &  it also aimed at knowing the differences between the dimensions of the measurement & the differences according to the kindergarten & class variables .

The researcher made a measurement for the class environment & it included five dimensions & the answering choices were three ( to a big extent , to some extent and no ) and after making sure that the measurement is usable , the researcher applied it on the sample which consisted of ( 212 )male & female children through the estimated answers of the teacher & the result was that there was an accep

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Publication Date
Sun Oct 02 2016
Journal Name
Journal Of Educational And Psychological Researches
القيادة الاستراتيجية المحددة لفاعلية الادارة العليا في جامعة النهرين
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Advantage of the science of management for a lot of other sciences vitality and openness to the rest of the science and knowledge of the various branches fields, and at the same time, overlapping and intermingling majora between the various branches of administration and specialties, and based on this fact, the idea of this research to come out of one of the important topics with two topics of vital in the field of strategic management, namely patterns Strategic Command, and the effectiveness of senior management teams. I've seen the science of management, particularly in the field of strategic management, large shifts and changes, especially in the last two decades, as the RPR Strategic Management rich field of research and the emergenc

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Publication Date
Mon Apr 29 2019
Journal Name
Arab Science Heritage Journal
الحياة الحياة الفكرية في العتبة العلوية للمدة (2003- 2017)
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      The holy city of Najaf is a vital space that helps to bring people together within a particular context, thus strengthening intellectual communication, community participation and increasing opportunities to learn about different cultures

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Publication Date
Wed Sep 25 2019
Journal Name
Journal Of The College Of Education For Women
التعايش السلمي بين الرسول (ص) والمخالفين له في المعتقد
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يتناول هذا البحث اساسيات التعامل بين الرسول الأعظم r وبين المخالفين له في المعتقد، وضرورة التسامح الديني الذي أقره الاسلام وطبقه الرسول الكريم r في حياته، وعلمه لأصحابه الكرام t، وأصناف الناس الذين تعايش معهم الرسول r مدة سيرته العطرة، لاسيما الكفار وأهل الكتاب والمنافقين، مستندا إلى كتب التفسير والحديث النبوي الشريف، وقد جعل الباحث لكل منهم مبحثا مستقلا ، ثم انتهى إلى الخاتمة وأهم التوصيات .

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Publication Date
Sun Apr 03 2011
Journal Name
Journal Of Educational And Psychological Researches
أسباب عزوف الطلبة عن دخول أقسام الرياضيات في الجامعات
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The current study aimed to know the reasons for the reluctance of
students to apply mathematics department in the Iraqi
universities. In order to achieve the objective of the study the
researchers a tool numbers of 4 - axes included 40 - paragraph,
distributed as follows:
- Set the first axis causes that relate to the student, the 14
paragraph.
- The second axis includes clauses concerning teacher and the
number of paragraphs of Article 9, paragraph.
- Axis III contains clauses concerning the nature of mathematics
and a number of paragraphs 11 paragraphs.
- The fourth, which included reasons related to classmates and
close and the number of paragraphs 6, paragraph.
The resolution offered on a group

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Publication Date
Sun Jan 01 2012
Journal Name
Journal Of The College Of Languages (jcl)
הריאליזם ביצירותיו של אהרן מגד "דוגמאות נבחרות מיצירותיו"
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הקדמה

             הריאליזם הספרותי במשמעו הכללי מצייג אשר כל מה מציינת בה הספרות מציורים מדוייקים לסביבה ולכן אדם. ויש להתחשב בפרטים המשותפים לחיים היומיומית.

             האסכולה הריאליזטית מצטיינת בזיאנרים אין זוכים בם איזו אסכולה ספרותית אחרת. האסכולה הזאת הופיעה בספרות העברית החדשה כתוצאה להשפעתה של הספרות העברית בס

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