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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 Oct 04 2009
Journal Name
Journal Of Educational And Psychological Researches
الكفايات التدريسية اللازمة للطالبات- المدرسات في كلية التربية للبنات من وجهة نظرهن
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     هدفت الدراسة الى تحديد الكفايات التدريسية اللازمة للطالبات- المدرسات من وجهة نظرهن وذلك للتعرف على مدى حاجتهن لهذه الكفايات التدريسية التي ينبغي امتلاكها لتحقيق الاهداف المنشودة.أشتملت عينة البحث على(100) طالبة من جامعة بغداد/كلية التربية للبنات/قسم التاريخ.تم اعداد اداة البحث وهي أستبانة مكونة من (43) فقرة خماسية البدائل هي (موافقة بشدة، موافقة،مترددة،غير موافقة،غير موافقة بشدة) موزعة على

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Publication Date
Sun Jul 11 2021
Journal Name
جامعة بغداد/ كلية التربية للعلوم الصرفة - ابن الهيثم
معايير CCSSM المتضمنة في كتاب الرياضيات للصف الخامس العلمي وتوافرها لدى الطلاب
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Publication Date
Sat Jan 05 2019
Journal Name
Journal Of Planner And Development
استشعار وحفز مفهوم "التنمية المستدامة" لدى طلبة مدارس اعدادية منتخبة في بغداد
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Publication Date
Sun Jun 18 2023
Journal Name
Arab Science Heritage Journal
رعاية الايوبييـن للعلـم والعلمـاء في مصـر وبـــــلاد الشـــــــام (567-648هـ/1171-1250م)
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The Ayyub era witnessed a popular for science, knowledge and became the Ayyub state in its various regions a scientific beacon، despite their preoccupation with wars with the Crusaders now that did not discourage them from their care for science and scientists، and this scientific renaissance had many factors، foremost of which are the tendencies of the sultans and Ayyub kings to pay attention to science and its care، through their establishment of the role of science

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Publication Date
Sun Oct 14 2018
Journal Name
Arab Science Heritage Journal
الاجراءات الإجراءات الإدارية والقانونية وسبل معالجتها لآزمة الأراضي في بغداد 1932-1938
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شكلت السيطرة العثمانية على العراق  حقبة تاريخية مهمة ، حيث وضعت فيها ركائز عدد كبير من الأنظمة الأدارية  فغدت  الأساس للتنظيمات  فيما بعد ومنها  الإجراءات الإدارية والقانونية وسبل معالجتها لآزمة الأراضي في بغداد1938-1932.

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Publication Date
Fri Dec 15 2023
Journal Name
Al-academy
Utilising modelling software to convert functional utensils into ceramic art.
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Contemporary art has been widely affected by technology, and ceramics production is no exception. As an ancient art that originates from clay and other humble materials found in the ground, ceramics is considered one of the most adaptable art forms. Once it is realised how flexible ceramics as a material is, it can be easily altered into endless forms and shapes. Therefore, it is vital for ceramics practitioners to find a relationship between this wonderful material and the media of contemporary art, culture and modelling software or technology in general so that they can take their deformable art pieces to a whole new level. Such a relationship is worth investigating. Thus, for the purposes of this research, several ceramic pieces were

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Publication Date
Tue Nov 06 2018
Journal Name
Arab Science Heritage Journal
وجوه من وجوه الاعجاز البلاغي في القرآن الكريم الايجاز (جوامع الكلم أنموذجاً)
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        The subject of the research is the collective words = Jawami Al-kalim. Those who wants to know this subject to be aware of the benefit of  "Al-Ejaz and Al-iktisar " and to cover the Rhetoric of signal should think carefully the abbreviations because the collective words because it is the a face of the important faces represented by the abbreviation of shortness as it is and old subject where it can be found in every source of rhetoric books which were old or modern. But what attracts attention is that this subject did not take all its range in study in the way that discover its beauty concerning style, words, sentences and meaning. This cause

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Publication Date
Tue Jan 05 2010
Journal Name
Political Sciences Journal
الجمود المؤسسي واثره في فشل التنمية السياسية : محاولة من اجل بناء مفهوم
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الجمود المؤسسي واثره في فشل التنمية السياسية : محاولة من اجل بناء مفهوم 

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Publication Date
Wed Sep 01 2010
Journal Name
Journal Of Economics And Administrative Sciences
التحليل الاحصائي لتجارب القياسات المكررة للبيانات المصنفة في حالة معالجتين وثلاث معالجات
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من اهداف بعض التجارب هي معرفة تاثير التسلسلات المختلفة لبعض الادوية او التغذية او تجارب التعلم. وفي بعض الاحيان قد تكون الوحدات التجريبية نادرة لهذا نقوم باستخدام الوحدات التجريبية على نحو متكرر. او بسبب الميزانية المحدودة فان صاحب التجربة يخضع كل وحدة تجريبية لاختبارات عديدة ويطلق على هذا النوع من التجارب التي يتم فيها استخدام الوحدات التجريبية (الاشخاص) Subject على نحو متكرر

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Publication Date
Thu Oct 01 2015
Journal Name
Journal Of Educational And Psychological Researches
القيادة التربوية في ضوء نظريتي x-yوعلاقتها بالروح المعنوية لمديري المدارس الإعدادية
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This study aimed to identify the educational leadership in the light of my theory xy and its relationship to the morale of the managers of the junior high school as the study population consisted of directors of junior high school in the city of Baghdad of six directorates education for the academic year 2013-2014 AD The number of managers (211) as director, and amounted to a sample Search of (150) director and director of the research community overall rate (71%) and represent this community fully representative sample, two tools were used in the study: the first measure of educational leadership in the light of my theory xy and the second tool to gauge morale.

Results concluded that the

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