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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
Wed Mar 30 2022
Journal Name
College Of Islamic Sciences
ما خالف به الامامُ ابن السبكي الامامَ الامدي في تشنيف المسامع باب القياس انموذجا
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The idea of ​​the research at first was to find out about the rare occurrence, which is the occurrence of a violation in the same madhhab and between two Shafi’i scholars such as Al-Amadi and Ibn Al-Subki. The scholarly had some brief and then moved on to the fundamentalist violations that occurred between them in the syllabus of the hearing within the chapter on analogy exclusively. The diffuse division (within the sounding and division) of the observer and the debates, or is it confined to the beholder without the debates, Imam Al-Amadi sees the inadmissibility of analogy with the reasons, while Imam Ibn Al-Subki argues that it is permissible, and Imam Al-Amdi sees that the widespread division is an argument for the observer (Muj

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Publication Date
Sun Jan 01 2012
Journal Name
Journal Of Educational And Psychological Researches
أثر استعمال الوسائل التعليمية للكتاب المدرسي ورسومات المعلم التوضيحية في تحصيل المعلومات التاريخية واستبقائها
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The research aims to determine the impact of the use of teaching aids for the textbook and graphics teacher illustrations in the collection of historical information and retention, limited research on a sample of students in grade five numbered (68) primary school students of Benin in Baghdad governorate / Breeding Rusafa First, select the researchers of scientific material for students in research Topics are the first and second chapter of the Book of the Arab-Islamic history, set by the Ministry of Education.

 And promising targets behavioral and according to the content of subject numbered (100) goal and lesson plans exemplary nu

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Publication Date
Fri Jun 01 2007
Journal Name
Journal Of Economics And Administrative Sciences
الاهمية الاقتصادية للموانىء الحرة مع الاشارة الى المنطقة الاقتصادية الحرة المقترحة في ميناء الفاو
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الاهمية الاقتصادية للموانىء الحرة مع الاشارة الى المنطقة الاقتصادية الحرة المقترحة في ميناء الفاو

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Publication Date
Sat Oct 01 2016
Journal Name
Journal Of Educational And Psychological Researches
المناخ المدرسي وعلاقته بالتكيف الاجتماعي لدى تلاميذ الصف الاول الابتدائي في محافظة اربيل/ المركز
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The research aims at defining the level of the school environment and the social adjustment of the sample due to the sex and the relation among them. The two researchers have stated the school environment scale counting on the theoretical background and previous studies. As for the social adjustment scale, the researchers have used the scale of (Al-Kindy, 2001) and the school environment scale is implicated on (112) students. The schools and the students were elected in a random way. Whereas the social adjustment scale is implicated on (30) teachers in order to know their ratio of the student's adjustment. The results have appeared the satisfaction of the students on the private school environment within their school aspects (the directo

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Publication Date
Tue Mar 31 2020
Journal Name
مجلة العلوم النفسية
اثر انموذج التفكير النشط في تحصيل طلاب الصف الثاني المتوسط لمادة العلوم وتفكيرهم البصري
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ان الهدف من هذا البحث هو التعرف على أثر انموذج التفكير النشط في تحصيل طلاب الصف الثاني المتوسط لمادة العلوم و تفـكيرهم البصري. تكونت عينة البحث من (58) طالباً، يتوزعون بين مجموعتين احدهما تجريبية و اخرى ضابطة. تم اعداد اداتين مقننتين احداهما لقياس التحصيل والاخرى لقياس التفــكير البصري، وبعد تطبيق تجربة البحث والحصول على البيانات، التي تمت معالجتها احصائيا باستخدام البرنامج الاحصائي(SPSS)؛ كشفت النتائج عن تفوق

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Publication Date
Tue Jan 01 2008
Journal Name
Journal Of Educational And Psychological Researches
أثر تدريس المواد البيئية في تنمية الاتجاهات البيئية لطالبات كلية العلوم للبنات – جامعة بغداد
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يهدف البحث إلى استقصاء أثر دراسة طالبات كلية العلوم للبنات في جامعة بغداد لمقرر التلوث البيئي في تنمية اتجاهاتهن البيئية، وذلك من خلال التعرّف على النمو في المستوى العام لاتجاهات الطالبات البيئية والكشف عن الفروق الإحصائية في اتجاهاتهن قبل وبعد دراسة المقرر.

وقد تألفت عينة البحث من(50) طالبة من طالبات قسم الفيزياء / الفيزياء الطبية المرحلة الأولى في كلية العلوم للبنات- جامعة بغداد. اعتمدت ا

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Publication Date
Thu Jul 02 2015
Journal Name
الاستاذ
النقد القصصي في منجزات الدكتور نجم عبد الله كاظم (القصة القصيرة والقصيرة جدًا أنموذجًا)
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Publication Date
Mon Oct 06 2014
Journal Name
Journal Of Educational And Psychological Researches
اثر برنامج أنشطة مكتبية لتنمية بعض القدرات الإبداعية في الأداء اللغوي عند اطفال الرياض
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This study aims to find out the impact of activities office provided to kindergarten children in the development of creativity in linguistic performance goal of capabilities (fluency, flexibility and originality) through the application of the test configuration Algheih Children Riyadh, which consists of (70) Single to measure the skills of language arts four a listening and speaking and a willingness to read and prepare for writing, was applied (30) Single of language arts, listening and speaking in this research, and was the correlation coefficient for the hearing (0.78) and for speaking was (0.61) has been extracted stability of the scale using the equation Alvakronbach the value of (0.73).

The proper

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Publication Date
Sun Jul 02 2017
Journal Name
Journal Of Educational And Psychological Researches
(دور الارشاد التربوي في محاربة المخدرات وتحقيق الامن النفسي من وجهة نظر المدرسين المرشدين )
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The research study aims to investigate the prevalence of the phenomenon of drags and the causes of this phenomenon from the teachers point  of view Two  hundred   Teachers  participated in this study Questionnaire  was used to  collect  the  data .                                 

The results emphasized the importance 0f the  educational  counseling  through  different  procedure  to prevent  drugs  abuse .   the results  also&

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Publication Date
Sun Jan 03 2010
Journal Name
Journal Of Educational And Psychological Researches
تقويم مستوى تضمين مناهج المرحلة الأساسية الدنيا (الصفوف 1-3) في الأردن لقيم المواطنة
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This study aims at assessing the availability of national values in the curriculum of the first three grades in Jordan. The study also aims at the nature of distributing these national values. The sample of the study consists of the curriculum of math, science, Arabic language, Islamic education, and national and civil education in Jordan. To achieve the aims of the study, the researchers used the analyzing approach, and they also depended on the referential statement for the general and                       minor objectives as a tool to analyze and numerate. The results of the study shows that the concentrating on the n

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