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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
Tue Jul 02 2024
Journal Name
مجلة الأستاذ للعلوم الإنسانية والإجتماعية
بنية الزمن في رواية ( ما بعد الجحيم ) للدكتور حسين سرمك حسن .
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يعد الزمان عنصراً جمالياً مساهماً له القدرة على خلق المعنى والدلالة ، ومشاركاً في الاستراتيجية الحكائية إذ ينتقل من مجرد عنصر حكائي إلى محرض للمتلقي فهو زمان الإنسان الداخلي .

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Publication Date
Mon Oct 22 2018
Journal Name
Arab Science Heritage Journal
السحر السحر وعقوبته في المجتمع الإسلامي من خلال القرآن والسنة النبويةالشريفة
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إن المعتقدات الخاصة بالسحر والعرافة قديمة جدا كون الإنسان عرف الكثير منها ومارس أنواع من الأساليب السحرية منذ أقدم العصور ومن أكثر العلوم التي حرم تعليمها ونشرها هو علم السحر والسيمياء أو الكيمياء والشعبذة والحيل . ومع ذلك عرف السحر من قبل سكان بلاد وادي الرافدين ولاسيما في بابل والسحر يمثل أقدم مرحلة في تطور العقل البشري .

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Publication Date
Thu Feb 07 2019
Journal Name
Journal Of The College Of Education For Women
الألفاظُ المُعَرَّبة في فتح الباري بشرح صحيح البخاري لإبن حجر العسقلاني
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This research deals with a range of vocabulary, non-Arab, which
appeared in a book Fath al-Baari by Ibn Hajar al-Askalani, so we display this
vocabulary and matrix is scholarly tuned in, interpretation and statement of
origin, and then matrix is what I'm stone in the view of the scientists and was
for Ibn Hajar outstanding efforts in the follow-up statements The scientists
documented a valuable book and it is fath Al-Bari important source of
vocabulary Aloagamip the complexity and multiplicity of views.

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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
Wed Sep 01 2010
Journal Name
Journal Of Economics And Administrative Sciences
آليات حوكمة الشركات التي تؤثر في اتخاذ المدقق الداخلي للقرار الاخلاقي
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اصبح لمجالس الادارة في الشركات دوراً حاسماً في تعزيز الحوكمة الفاعلة، كونها تتحمل المسؤولية النهائية عن نظم الرقابة الداخلية في شركاتها، ويلعب التدقيق الداخلي دوراً اساسياً في مساعدة تلك المجالس على القيام بمهمات الحوكمة. ولهذا يبذل مجمع المدققين الداخليين الامريكي جهداً كبيراً في توجيه اعضاءه ليكونوا متخصصين في اصول حوكمة الشركات وتحسين وتقوية اخلاقيات العمل وسلامة المنظمة.

لذا فإن ا

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Publication Date
Mon Jun 01 2015
Journal Name
Journal Of The College Of Languages (jcl)
LA LITTÉRATURE RÉDUCTIBLE Analyse critique de l’exploitation du texte littéraire dans Le « Mauger Bleu »
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RÉSUMÉ                                                    

            LeMauger Bleu est une méthode emblématique de l’enseignement traditionnel, qui présente une littérature française riche et patrimoniale, et dont l’objectif est de faciliter l’accès au texte par le vocabulaire et la grammaire et d’étendre la culture générale et littéraire de l’apprenant. La démarche (traditionnelle) est toujours la même : le texte, le vocabulaire et la grammaire, la traduct

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Publication Date
Tue Jul 02 2024
Journal Name
مجلة الأستاذ للعلوم الإنسانية والإجتماعية
بنية الزمن في رواية ( ما بعد الجحيم ) للدكتور حسين سرمك حسن
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يعد الزمان عنصراً جمالياً مساهماً له القدرة على خلق المعنى والدلالة ، ومشاركاً في الاستراتيجية الحكائية إذ ينتقل من مجرد عنصر حكائي إلى محرض للمتلقي فهو زمان الإنسان الداخلي .

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Publication Date
Tue Aug 03 2021
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Using financial and non-financial information ) SASB standards) to enhance investor confidence
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Companies seek to enhance investor confidence by achieving the highest level of transparency in disclosure of financial and non-financial information (SASB standards) for Iraqi insurance companies listed on the financial market. The aim of the research is to identify the extent of the ability of financial and non-financial information to enhance transparency in reporting, which is reflected in Investor confidence. And the standards of sustainability development accounting issued by (SASB) through the electronic questionnaire that was distributed. Companies seek to achieve a set of goals, the most important of which is to enhance investor confidence by improving transparency in disclosure. Concerning the employment of financial an

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Publication Date
Fri Apr 01 2022
Journal Name
Baghdad Science Journal
Improved Firefly Algorithm with Variable Neighborhood Search for Data Clustering
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Among the metaheuristic algorithms, population-based algorithms are an explorative search algorithm superior to the local search algorithm in terms of exploring the search space to find globally optimal solutions. However, the primary downside of such algorithms is their low exploitative capability, which prevents the expansion of the search space neighborhood for more optimal solutions. The firefly algorithm (FA) is a population-based algorithm that has been widely used in clustering problems. However, FA is limited in terms of its premature convergence when no neighborhood search strategies are employed to improve the quality of clustering solutions in the neighborhood region and exploring the global regions in the search space. On the

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Publication Date
Mon Sep 01 2008
Journal Name
Journal Of Economics And Administrative Sciences
الهــــــــــدم الخــــــــــــلاق Creative Destruction وإمكانية اعتماد كنموذج ابداعي في المنظمات العربية
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أن هذه الدراسة هي دراسة نظرية اهتمت بتقديم مدخل معاصر لمنظمات الأعمال، يمكن أن يعتمد علية من أجل تحقيق الريادة و البقاء. وذلك من خلال اعتماد مدخل الهدم الخلاق و تقديم أنموذج قادر على التفاعل مع البيئة بكل ما تقدمه من فرص وتحديات.

وتم تقسيم هذه الدراسة إلى ثلاثة مباحث،تناول المبحث الأول منهجية الدراسة. وبينما تناول المبحث الثاني توضيح مفهوم الهدم الخلاق والعناصر المكونة لهذا المدخل وأخيراً

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