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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 Dec 13 2017
Journal Name
Al-khwarizmi Engineering Journal
A Comparison Between Recursive Least-Squares (RLS) and Extended Recursive Least-Squares (E-RLS) for Tracking Multiple Fast Time Variation Rayleigh Fading Channel
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In order to select the optimal tracking of fast time variation of multipath fast time variation Rayleigh fading channel, this paper focuses on the recursive least-squares (RLS) and Extended recursive least-squares (E-RLS) algorithms and reaches the conclusion that E-RLS is more feasible according to the comparison output of the simulation program from tracking performance and mean square error over five fast time variation of Rayleigh fading channels and more than one time (send/receive) reach to 100 times to make sure from efficiency of these algorithms.

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Publication Date
Thu Nov 12 2020
Journal Name
Arab Science Heritage Journal
( مُختَصَرُ الإمام المَيدانيّ في عِلم التَّصريف ) للإمام أبي الفضل أحمد بن محمّد بن إبراهيم الميداني ( ت 518 هـ )
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    The aim of this research is to make a new investigation of a scientific thesis in Arabic Morphology in which an allusion occurred in relation to its real author and its title, there is alot of dropping and flaw when it was first applied due to depending on one written transcript

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Publication Date
Fri Jun 30 2023
Journal Name
Modern Sport
اثر تمرينات خاصة بأستخدام جهاز المدافع الضوئي المصمم في تنمية بعض القدرات البدنية والاداء المهاري المركب لدى لاعبي كرة اليد
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اتجهت دول العالم الى تسخير جميع الإمكانيات والخبرات والعلوم من اجل الوصول الى مستويات متقدمة في الرياضات المختلفة ويهدف التدريب الرياضي إلى إعداد اللاعبين إعدادا جيدا تكمن مشكلة البحث من خلال خبرة الباحثتان الميدانية ومتابعة تدريبات لاعبي المدرسة التخصصية كرة اليد فقد لوحظ هناك ضعف واضح في الأداء المهاري ولابد من تطوير أوجه الضعف لتحقيق مستوى انجاز افضل . ويهدف البحث اعداد تمرينات خاصة بأستخدام جهاز ا

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Publication Date
Tue Sep 27 2022
Journal Name
Arab Science Heritage Journal
الحركة العلمية في المغرب الاسلامي من خلال كتاب معجم البلدان لياقوت الحموي ( ت 626هـ / 1229م) العلوم الشرعية انموذجا
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    The Dictionary of Countries by Yaqut al-Hamawi is one of the most important sources that researchers rely on in everything related to geography in knowing the names of places and countries, and the important historical information it contains about different cities and countries

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Publication Date
Tue Sep 27 2022
Journal Name
Arab Science Heritage Journal
آل البيت ( عليهم السلام ) من خلال كتاب درر السمط في خبر السبط لابن الابار البلنسي الاندلسي ( ت658هـ/1260م)
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One of them one of the important books due to its containing valuable information written by the author. Information include the life of the Messenger (Peace be upon him)

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Publication Date
Sun Jan 01 2006
Journal Name
Journal Of Educational And Psychological Researches
واقع استخدام الوقت من قبل رؤوساء الأقسام العلمية "بحث ميداني في عينة من كليات ومعاهد هيئة التعليم التقني"
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          يهدف البحث لمحاولة دراسة واقع ادارة الوقت لدى عينه من  رؤوساء الأقسام العلمية في كليات ومعاهد هيئة التعليم التقني اذ بلغ حجم العينة (47% )  فرداً  تم احتيارهم عشوائياً من (15) كلية ومعهد موزعة في (69 من محافظات القطر  وبلغ حجم عينة البحث (17%) من عدد رؤوساء الاقسام العلمية في الهيئة ،  ولغرض جمع البيانات تم  أعداد استمارة استبيان تمت صياغتها بشكل يؤمن توثيق الوقت الفعل

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Publication Date
Tue Sep 27 2022
Journal Name
Arab Science Heritage Journal
الحركة العلمية في المغرب الاسلامي من خلال كتاب معجم البلدان لياقوت الحموي ( ت 626هـ / 1229م) العلوم الشرعية انموذجا
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The Dictionary of Countries by Yaqut al-Hamawi is one of the most important sources that researchers rely on in everything related to geography in knowing the names of places and countries, and the important historical information it contains about different cities and countries

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Publication Date
Thu Dec 26 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
أثر سياسة السجلات المحاسبية المفتوحة كأحد آليات إدارة التكلفة في تحقيق الميزة التنافسية للشركات الصناعية المساهمة العامة الأردنية
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The aim of this research is to study and test the impact of the policy of open-book accounting as one of the cost management mechanisms in achieving the competitive advantage in Jordanian industrial public companies, to achieve the objectives of the study, a field study was conducted by surveying the views of a sample of the accountants of the Jordanian industrial public companies. Hence the arithmetical Means, the Standard Deviations, the Significant Value and the Simple Linear Regression are used to test the research hypotheses and to achieve the research goals. The results of the study showed that there is a statistically significant effect of the policy of open-book accounting as one of the cost management mechanisms in achieving the

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Publication Date
Tue Jan 08 2019
Journal Name
Arab Science Heritage Journal
استخلاص عامل التلزن ( اللكتين ) من بكتريا لخلاياEnterococcus faecalis EM1 ودوره في تلزن انواع من البكتريا السالبة لملون غرام
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استخلص عامل التلزن من E. faecalis EM1 بعد تكسير بالكرات الزجاجية والترسيب بالكحول الاثيلي , واجري فحص التلزن وقياسه لمستخلص لخلايا  E. faecalis  مع انواع من البكتريا السالبة لصبغة غرام تضمنت     Escherichia coli  و Klebsiella  pneumonia  و Serratia marcescens   و Pseudomonase aeruginosa و Salmonella typhi , بينت النتائج ان اعلى نسبة تلزن للخلايا والمستخلص تكون مع بكتريا    ٍK. Pneumonia  حيث بلغ66.5 % مقارنة بالسيطرة79.5 % , واوطا قيمة للتلز

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Publication Date
Tue Dec 22 2020
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
تحليل العلاقة بين تحسين الأداء المالي للمصارف و جذب الودائع: بحث تطبيقي في عينة من المصارف العراقية الخاصة
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The banking performance and deposits attraction are considered to be of great importance in banks management, also the banking  performance is one of the indications that measure the ability of satisfying and full fill the banks  goals and the range of approach and move away from those goals, Also there are some important factors that affects on deposits, such as financial performance ,The aim of the research is to measure and analyses the banking performance and showing its effective impact and its relation in attracting deposits.

For the satisfaction of the research goals a smple was selected from the Iraqi banks which represented in five private banks were their data been analyzed between the periods 2009 to 2013 ,th

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