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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
Mon Sep 01 2008
Journal Name
Journal Of Economics And Administrative Sciences
التقييس: أسلوب لتحديد مستوى الدخل في العراق
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ظهر التقييس كمفهوم لقياس الضرائب وتحديد الأجور والرواتب منذ مدة ليست طويلة وتم استخدامه في العديد من بلدان العالم. ولاجل تحقيق العدالة في توزيع الدخول ورفع المستوى المعيشي لذوي الدخول المحدودة، اذ يتطلب من الدولة إتباع أسلوب التقييس للأجور والرواتب للموظفين ،إضافة إلى استخدام التقييس في فرض الضرائب وتحديد السماحات اعتمادا على مستوى التضخم في الاقتصاد. خاصة وان الهدف الأساسي من إتباع أسلوب التقييس هو

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Publication Date
Wed Nov 28 2018
Journal Name
Arab Science Heritage Journal
النشاط النشاط الطبي في العصريين الراشدي والأموي
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the subject of medical activity in eras Rashidi and Umayyad is one of the most important for study  because Medicine is related to human life and health Medicine is important science which should be identified and interested. the Prophet Muhammad emphasized God bless him and to pay attention to the study of medicine through the Hadith.

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Publication Date
Sun Jan 01 2012
Journal Name
Political Sciences Journal
دور المنظمات الدولية في تفسير معاهداتها المنشئة
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دور المنظمات الدولية في تفسير معاهداتها المنشئة

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Publication Date
Wed Nov 14 2018
Journal Name
Arab Science Heritage Journal
المنافع المنافع الحيوانية الواردة في القرآن الكريم
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Quran is a basic reference of production it is as a source to all sciences, Ayat of Quran would mention the importance of benefits of animals.  Quran contain full surrat named in animal names as Al-Baqara that is to clarify its benefits and importance in human’s life.

 

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Publication Date
Sun Jan 01 2012
Journal Name
Political Sciences Journal
النظام القانوني للمعاهدات الدولية في القانون العراقي
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النظام القانوني للمعاهدات الدولية في القانون العراقي

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Publication Date
Thu Oct 01 2015
Journal Name
Journal Of Educational And Psychological Researches
الشخصية العراقية في سياق تكامل الاسرة الحضرية
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From the above can be placed in a summary of the Iraqi personal to the subject in the context of urban family Integration: As personal so hard and durable organization to some extent on the nature of the individual temperament, his mind and his body structure Vhoalve determines the unique environment compatibility.
Valchksah not inherited However, the inherited components, building of the body of the individual and the way they complement each other and members of Trivhalta functions performed by temperament and preparations all in compliance with Vchksath become a product of the interaction between the possibility of nature and the environment.
From here we can say that the family a big role in the personal configuration,

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Publication Date
Thu Jan 01 2015
Journal Name
Political Sciences Journal
US-Iranian relations under President Obama
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تنتاب العلاقةَ الأمريكية الإيرانية تجاذباتٌ ومشاحنات أدخلت العالم في حالة من الغموض السياسي، وجعلت بعض المراقبين والمحللين السياسيين لا يستبعدون توجيه الولايات المتحدة الأمريكية أو إسرائيل ضربة عسكرية لإيران، إذ يرى المدقق في واقع تلك العلاقة المضطربة: أن الأمور كلما بلغت حافة الهاوية عادت من جديد إلى ساحة الحوار والمفاوضات، ويبدو: أن الإستراتيجية الأمريكية التي يتبعها الرئيس (باراك أو

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Publication Date
Tue Jun 03 2003
Journal Name
Al-academy
الرؤية السايكلوجية وتطبيقاتها في مسرحية الشيخ والغانية
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الرؤية السايكلوجية وتطبيقاتها في مسرحية الشيخ والغانية

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Publication Date
Tue Jun 01 2004
Journal Name
Al-academy
مفهوم البعد الواحد في الرسم العراقي المعاصر
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مفهوم البعد الواحد في الرسم العراقي المعاصر

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Publication Date
Mon Oct 15 2018
Journal Name
Arab Science Heritage Journal
المعالم المعالم العمرانية القديمة في قلعة كركوك
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This study examines the remaining architectural features in Kirkuk Castle,which does not include the heritage buildings outside it. The castle's fortifications are limited about military samples of the city during the Ottoman era ,concentrating on the importance remains of the walls that held on the edge of the hill leads to the interior, As well as some religious buildings such as mosques, shrines and churches, and the service buildings with most important caesarean dating back to the Seljuk era and a range of housing    The importance of the subject lies in the study of these buildings , documentation, and knowledge of the designs and models of building to make it a link in the series of the late Islamic architecture

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