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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 05 2014
Journal Name
Journal Of Educational And Psychological Researches
مشكلات الطلبة العراقيين الدارسين في أوكرانيا وعلاقاتها ببعض المتغيرات
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Chapter One

First, the importance of research and the need for him

Highlight the status of the nation and occupies a decent position among nations by what they offer for the good of humanity and tender, which is based mainly on the human and material wealth owned by the nation.

The investment of this wealth investment scientifically accurate based on the strong foundation that qualifies them to heights of glory, so stand out necessary development of all energies Alepeshriaaly the limit can not be considered as these energies fortune unless all elements of effective elements characterized by the positive interaction in various spheres of life and in the in

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Publication Date
Wed Nov 28 2018
Journal Name
Arab Science Heritage Journal
الصناعة الصناعة في بغداد للفترة (334هـ /935م -555هـ/ 1160م)
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The industries in Baghdad, the most important economic activities in the era albeit and Seljuk to the availability of manpower and resources which encourage the establishment of these industries in Baghdad.

These industries seam as simple crafts, but they may have influenced the nature of the social and economic life in the Baghdadi community during the foreign authority on Iraq and general in Baghdad in particular.

 

 

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Publication Date
Wed Mar 15 2023
Journal Name
مجلة بحوث الشرق الاوسط
جدلية العلاقة بين السلطة والعنف في الفكر السياسي الاسلامي
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Publication Date
Sun Oct 01 2023
Journal Name
مجلة دراسات دولية
الذكاء الاصطناعي والوجود الإنساني: قراءة فكرية في الابعاد الاجتماعية
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Publication Date
Thu Aug 27 2020
Journal Name
Arab Science Heritage Journal
الفكر الإداري للإمام علي (عليه السلام) في سياسة الدولة
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  The political system during the reign of Imam Ali (peace be upon him) was based on explicit openness in its features and objectives away from misinformation, and built its foundations and foundations on the Koranic legislation, and enacted by the Prophet (peace be upon him), and the decent legislation required by humanity

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Publication Date
Wed Jan 01 2014
Journal Name
Journal Of The College Of Languages (jcl)
La Visión Filosófica en las Célebres Obras Literarias y Dramáticas de Unamuno
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Desde la Salamanca de doradas piedras que tantas veces cantara, don Miguel de Unamuno dio a la literatura y al pensamiento españoles unas obras que, a pesar de muchos pesares, perdura viva, como viva fue su agónica existencia.  

   El bilbaíno Miguel de Unamuno (1864-1936) es autor de al menos, doce obras teatrales. Su costumbre de mezclar géneros literarios, sin distinguir claramente el drama de la novela dialogada, le llevó a preferir el teatro leído. De ahí que sus estrenos fuesen, frecuentemente, muy posteriores a las ediciones impresas.

Abstract:

   The Bilbao Miguel de Unamuno (1864-1936) is the author of at least twelve plays. His habit of mixing genres,

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Publication Date
Sun Jan 01 2006
Journal Name
Journal Of Educational And Psychological Researches
اثر لعبة كرة القلب في خفض غضب أطفال الروضة
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مشكلة البحث واهميته :

            يعد الغضب من المظاهر الانفعالية الشائعة في مرحلة الطفولة المبكرة وذلك بسبب كثرة المواقف المثيرة لغضب الطفل في هذه المرحلة ، كما ان الطفل في هذه المرحلة سرعان ما يكتفي في كثير من الاحيان بان غضبه وبكائه طريقة سهلة للوصول الى ما يريد . ويعد المختصون في هذا المجال ، بان نوبات غضب الاطفال ، هي شيء عام طبيعي عند جميع الاطفال ، لكن عندما تكون نوبات عنيفة

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Publication Date
Fri Feb 08 2019
Journal Name
Journal Of The College Of Education For Women
إدراك الأزیاء في ظل علاقاتھا الجمالیة بعناصر العرض المسرحي
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The fashion accused important optical avenge with the rest of visual elements
, That style of fashion design stir up beautiful feelings by using fashion forming
that is suitable with the nature of designable treatments to other elements .
The fashions contains the nature of relation ships of educational address and
the kind of beliefs , So the visual beauty is limited for those relation which are the
designer fashion tried to redesign and set them anew . so as to goes with beautifully
with the last visual for fashions.

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Publication Date
Mon Jan 23 2023
Journal Name
Arab Science Heritage Journal
الترادف في التعليق المغني لشمس الحق محمد العظيم آبادي
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Praise be to God, Lord of the Worlds, and prayers and peace be upon our master and beloved Muhammad and all his family and companions. As for what follows:

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Publication Date
Tue Jun 01 2010
Journal Name
Journal Of Economics And Administrative Sciences
مقارنة بعض المقدّرات الحصينة في دوال التمييز بأستخدام المحاكاة
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The development in manufacturing computers from both (Hardware and Software) sides, make complicated robust estimators became computable and gave us new way of dealing with the data, when classical discriminant methods failed in achieving its optimal properties especially when data contains a percentage of outliers. Thus, the inability to have the minimum probability of misclassification. The research aim to compare robust estimators which are resistant to outlier influence like robust H estimator, robust S estimator and robust MCD estimator, also robustify misclassification probability with showing outlier influence on the percentage of misclassification when using classical methods. ,the other

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