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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 14 2026
Journal Name
Арабистика Евразии
بين اللغة والوطن قراءة في قصة خواجة نزار لموشيه سميلانسكي
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يهدف هذا البحث إلي معرفة معنى اللغة وتجلياتها في نتاجات الاديب الإسرائيلي الأكثر جدلا في القرن العشرين، إلا وهو الاديب "موشيه سيملانسكي". فقد طغت صورة العربي في الكثير من أعماله الأدبية وتبوات مكانا واضحا، وكانت النظرة تجاهه، نظرة واضحة أيضا، فصورته لم تتغير بتغير الظروف والاتفاقيات، بشكل يتناسب وهذه الظروف، وإنما بقيت تراوح مكانها، ولم تتبدل بنظرة احترام على الأقل، بل على العكس من ذلك، فهناك بعض المطالبات

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Publication Date
Thu Oct 01 2020
Journal Name
العلوم الانسانية والاجتماعية
الاحكام الناشئة عن المنافسة غير المشروعة في نطاق الملكية الصناعية
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Publication Date
Fri Feb 08 2019
Journal Name
Journal Of The College Of Education For Women
العوامل المؤثرة في تخفیف الأعباء المنزلیة لدى المرأة العراقیة العاملة
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In the past, an absolute authority was held by the father and his decisions were imposed
and obeyed strictly without discussion. Later, many economical changes took place and
affected all of the family members dramatically creating a whole new concept of authority
in the family, a one that is based upon sound leadership, mutual understanding and
consultation among family members.
Women carried responsibility of doing all domestic jobs and served family members,
however, when she went to work outside her house, these loads began disturbing and
exhausting her. Therefore, man started to participate in assisting his wife. In addition,
industrial advances contributed in making these jobs easier than before.
This has

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Publication Date
Sun Jan 01 2012
Journal Name
جامعة كربلاء
الوصف الشكليائي والتركيب النسجي لغدة المعثكلة في الوزغة خشنة الحراشف
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Publication Date
Mon Jan 27 2020
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
تقييم تجربة المشاركة الأجنبية في عينة من المصارف العراقية الخاصة
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           The international field has witnessed economical and technological developments which made the world one market . this increased the competence among the international dealers .  the market, thus comprises states, governments, international organizations, and giant economic blocs which all seek to unify the behavior of the game by dealing and seizing the opportunities and facing the threats which concern deregulation in all its forms .This led to a number of developments including the increasing number of mergers and posts which are considered investment alternatives.                &nb

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Publication Date
Tue Mar 01 2011
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
اطار مقترح لمؤشرات بطاقة قياس الاداء المتوازنة في المؤسسات التعليمية
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Performance measurement is considered one of the most important issues in

Measuring performance effectiveness in the educational institutions by maintaining balance among quantity measurable factors. They can be financial or non‐financial factors. Consequently they reflect decisive factors in the success of educational institutions and determining suitable standards and dimensions for their activities and giving it proportional importance. Adopting the idea of Balanced Score Card as one of the modern administrative techniques and methods by educational institutions assists in the development of administrative work, adjusting the performance in addition to achieving comprehensive standard and development of educational universit

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Crossref (2)
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Publication Date
Thu Jan 01 2015
Journal Name
الاستاذ
شعر المرأة في الأغاني لأبي فرج الأصفهاني(العصر العباسي أنموذجًا)
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Publication Date
Sun Jan 27 2019
Journal Name
Journal Of The College Of Education For Women
Aldura Alyatima fi Bath Manakeb Alsayada Aladhimaa ( Fatema Al Zharaa apace upon her)
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This search in the virtues of the daughter of the Prophet Muhammad, to read on their boards want to recount loving and faithful), as stated in the introduction to the author, Abdullah Bin Ibrahim Al-Mirghani (D. 1207 H.) to give reasons in writing the manuscript, which was of an introduction and three chapters and a conclusion was the first in the door thanks to the great lady and on her birthday and her marriage and her death and subsequent events and the third in her them prayers and then the finale which was in love with the Prophet and calling for God to pardon and forgiveness and a good end. I was interested in this manuscript by Mirghani, Hadith and all accounts in reference to the virtues of the great lady to examine a manuscript

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Publication Date
Mon Dec 02 2024
Journal Name
مجلة الانبار للعلوم القانونية والسياسية
دور القانون الجنائي في حماية تاريخ الدول ( الاثار العراقية انموذجاً)
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Publication Date
Sun Sep 01 2024
Journal Name
مجلة ديالى للبحوث الإنسانية
البنية التركيبية والبيانية في قصيدة (أدر الكؤوس) لعبد الحسن زلزلة
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يعد التحليل البلاغي تركيبيا وبيانيا من الآليات الكاشفة عن الدلالات العميقة المتولّدة جراء علاقات البنية السطحية ، مكونة نسقاً دلالياً متماسكاً ومشحوناً بتكثيف معنوي للصور البلاغية المنسوجة في نص القصيدة، والتي تفتح للمتلقي نافذة التشكيل المتخيل لحال الشعب وحاكمه ، والعلاقة القائمة بينهما في القصيدة ، إذ نسج الشاعر علائقية متنامية الدلالة بين أجزاء قصيدته ووحداتها ؛ لتكون كلاً واحداً ناقلاً المتلقي لواق

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