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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
Sat Feb 02 2019
Journal Name
Journal Of The College Of Education For Women
اسلوب القسم الظاهر واثره في بناء النص القراني سورة العاديات ..........انموذجا
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Publication Date
Sun Apr 01 2012
Journal Name
Journal Of Educational And Psychological Researches
تطوير واقع مقرر التطبيقات التدريسية في أقسام كليات التربية جامعة بغداد
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The followers of the reality of the decision application faculty in departments of faculties of education of the University of Baghdad, it is noted that there are many shortcomings, which relate to Path, management, design, and evaluation, Coming from the work of the researcher as a teacher and supervisor, as well as to inform the researcher on many of the studies and literature, luck researcher on the article there are no courses are clear in theory and in practice the decision of the applications teaching, and often puts the teacher education curriculum, which lacks the link between the theoretical and practical, either in relation to its management, there is no office for the management and coordination at the University of Baghdad or

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Publication Date
Mon Dec 01 2008
Journal Name
Journal Of Economics And Administrative Sciences
ستراتيجيات ردم الفجوة الرقمية في دول الاسكوا – مع إشارة خاصة للعراق-
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إن التغيرات السريعة والبعيدة المدى في تكنولوجيا المعلومات القائمة على أساس الالكترونيات الدقيقة تساعد في حدوث تحول في صورة الاقتصاد العالمي، وكذلك تساعد في تغيير المزايا التنافسية للبلدان، وربط المؤسسات البعيدة ببعضها البعض، ونشر الخدمات المالية على نطاق عالمي، وكذلك إثارة مشكلات جديدة او العكس فتح فرص جديدة أمام تنمية ونمو أفقر البلدان .

وأدت هذه التكنولوجيا الجديد

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Publication Date
Fri Feb 08 2019
Journal Name
Journal Of The College Of Education For Women
السلوك القیادي لدى الاطفال الایتام واقرانھم غیر الایتام في المرحلة الابتدائیة
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The family is considered one of the most important social institutions which has a
strong and clear effect on the child in forming his personality through the process
of social upbringing which works on transforming the child from a merely
biological being into an individual who has customs and traditions and the behavior
of the group to which he belongs, and till now there is no social organization or
institution that can do this process not even in partial way like the family
.Therefore depriving the child of his parents leads to depriving him of the normal
chances of growth which relate to his age stage and thus this shortcoming is hard to
treat and based on the preceding the current research aimed at the follo

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Publication Date
Sun Jul 01 2012
Journal Name
Journal Of Educational And Psychological Researches
الاشكال المفضلة لدى اطفال الرياض ونسبة توظيفها في تصاميم اثاث الرياض
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The research explores the shapes preferred by children and the extent to which it can be utilized on the experimental kindergarten at the Woman’s School of Education. To achieve the goal, the researcher has displayed pictures that have been chosen from within the research boundaries which represent four categories: Geometrical shapes which included (squares, rectangles, triangles, and circles), agricultural shapes which included (apples, oranges, bananas, and grapes), motion pictures shapes (cartoon characters) which included (Jerry the mouse, Twitty the bird, Bugs Bunny the rabbit, and Winnie the pooh), and animal shapes which included (dogs, fishes, frogs, and horses) to the sample children of (60) child (boys and girls) that

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Publication Date
Tue Dec 31 2019
Journal Name
Arab Science Heritage Journal
حفظ حفظ القرآن الكريم ودوره في تعليم اللغة العربية للناطقين بغيرها
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When Allah has chosen Arabic language to be the eternal language of the Holly Qura'an, Qura'an was the original resource of the perfect grand Arabic

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Publication Date
Wed Jun 01 2011
Journal Name
Journal Of The College Of Languages (jcl)
توظيف التراث واللون في روايتي نبوءة فرعون وشاي العروس لميسلون هادي
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The novel in its construction depends on set of life elements that is employed by the writer or the novelist to create a convincing world that resemble the real life world and as the novel is going toward experimentation and employing modern phenomenon we find the novelist tends to take advantage from the most realistic details to achieve the required convincing state through serious situations and the novelist Maysaloun Hadi depended in writing her novels on creating tight relations between the things and the elements that has inspired her which are mostly from the environment and from reality , as an example of these elements is the old inherited traditions that distinguish Iraq society as this element is a very important point in Iraq

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Publication Date
Sun Jul 17 2022
Journal Name
Al–bahith Al–a'alami
Employing; Health Awareness, Health Awareness Announcements: (A research takenfrom a master’s degree thesis)
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The goal of health awareness is to familiarize people with health information and facts, and make them realize their sense of responsibility towards their health and the health of others.   And translate that goal in practice through applying healthy and sound behaviors spontaneously. This, the goal, is pursued by health awareness announcements through employing announcement persuasion of health as one of the methods of influencing the masses to adopt ideas, behaviors, and adherence to health advice and guidelines; The study aims to analyze the content of the Ministry of Health and Environment announcements regarding health awareness and to reveal the most employable persuasions in health awareness announcements

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Publication Date
Sun Jul 02 2006
Journal Name
Journal Of Educational And Psychological Researches
اثر العصف الذهني في تحصيل طلبة الصف الثاني متوسط بمادة التاريخ
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أولاً : مشكلة البحث :

أن مشكلة البحث تتمثل بوجود حاجة لتحسين الطرائق والأساليب المتبعة في التدريس ولذلك اتجهت البحوث في مجال التربية وعلم النفس إلى تحديد طرائق التدريس المناسبة لتطوير التفكير.         

ومن هذه الأساليب الحديثة  العصف الذهني بوصفها من اكثر الطرق التي قد  تؤدي إلى تحفيز الطلبة وأثاره القدرات الإبداعية لديهم في حقول التربية والتعليم وا

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Publication Date
Fri Jun 01 2012
Journal Name
Journal Of The College Of Languages (jcl)
Le rire amer du point de vue énonciatif dans " la guerre de Troie n' aura pas lieu" de Jean Giraudoux
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Si le rire est censé être le propre de l'homme, il n'en est pas pour autant toujours signe d'intelligence. Qui n'a  jamais eu honte d'avoir ri àune blague idiote ou méchante?

     Il y a plusieurs  façons  de rire , ce qui fait que ce qui est  comique  pour les uns ne l'est pas pour les autres et que le comique réside moins dans l'objet ( situation, blague..) que dans le point de vue et dans l'interprétation que nous en ferons. " Le rire .. contient toutes les mélancolies humaines ([1]) ".

([1] )

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