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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 Mar 02 2024
Journal Name
مجلة الذكوات البيض
أشكالية توظيف الخطاب السياسي ودوره في تعزيز السلم المجتمعي: العراق انموذجا
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لكل دولة في هذا العالم خطابها السياسي والذي يحدد سياستها الداخلية والخارجية، وهي سياسة ثابتة تنطلق من مفاهيم وبرامج وثوابت تخدم مصالحها الحيوية، لكون الخطاب السياسي ليس مجرد كلام عابر في عالم السياسة الدولية وانما هو ثوابت مهمة يحدد توجهات هذه الدولة او تلك ويحدد دورها الدولي وطبيعة العلاقة مع البلدان الاخرى ومنها الدول المجاورة لها. شهد العراق بعد العام 2003 تحديات جديدة تمثلت بتغليب خطابات الطائفية والكراه

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Publication Date
Tue Aug 06 2024
Journal Name
مجلة دراسات في التاريخ والاثار
فلسفة بوكر تاليافيروواشنطن وآرائه في اصلاح الأحوال العامة للسود 1895-1900
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ناولت هذه الدراسة إحدى الشخصيات الأمريكية التي تأثرت بواقع السود. كان بوكر تاليافيرو واشنطن أحد الأمريكيين السود ، الذين ولدوا في ظل العبودية وتعرضوا للاضطهاد بعد إلغاء حقوق التصويت وإطلاق قوانين جيم كرو من قبل الولايات الجنوبية. ورأى واشنطن خلال عمليات إعادة الإعمار أحوال السود وكيف كانت معاناتهم قبل الحرب الأهلية في ظل ظروف العبودية التي شملت الإذلال ، والحرمان من حقوقهم المدنية والسياسية، فيما لم يختلف

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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 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
Fri Feb 08 2019
Journal Name
Journal Of The College Of Education For Women
ملامح معاییر نقدیة في مقامة الشعراء (الموفیة) للسرقسطي ت ٥٣٨ ھ
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Stop and stop Alsergsti classed many of the characteristics of great poets and
literary arts and persuasions, in Mqamth cash cash Antzmtha three criteria: the
standard of Islam and the standard time, and Maaartadd purposes of poetry. This
has had its effect on lighting stand many of the goals of the poets and their
attitudes.
The first criterion: Those who study the positions of Alsergsti to poetry and
poets must be discerned his money comes from the spirit of Islam as a religion and
creed and a system, a position that is encouraging him wherever expressed, such as
the Muslim community the new values, away from the vulgarity, which contributed
to the formulation of the standard of religious poetry criticism.

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Publication Date
Mon Nov 19 2018
Journal Name
Arab Science Heritage Journal
مصادر مصادر القانون الدولي في الألفية الثانية ق.م (أواخر عصر البرونز)
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 In the second millennium BC, the international community change at the ancient Near East, There has been a significant developments with the appearance of five kingdoms (Babylon, Assyria, Mitanni, Egypt, and Hatti) called themselves the (Great Powers) and their kings named (Great King), and Correspondence among themselves on behalf of (the brothers),  to differentiate themselves from the small kingdoms Minor of them.

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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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Crossref (3)
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Publication Date
Thu Apr 01 2021
Journal Name
Journal Of Engineering
Innovation Diffusion Elaboration into Architectural Movement
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The research investigates the term innovation and its role in elaborating architectural practice based on diffusion. The complexity of the architectural field compared with other fields shows a problem in explaining how innovations in architecture diffuse as a thought and act in a certain context of practice. Therefore, the research aims to build an intellectual model that explains the way personal thoughts resembled by unique models introduced by creative and innovator designers diffuse in a certain pattern elaborate these models into a state of prevailing thought resembled by the movement in architecture. The research will apply its model to the more comprehensive movement in architecture, which is the modern movement,

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Crossref
Publication Date
Tue May 16 2023
Journal Name
Journal Of Engineering
System Identification Algorithm for Systems with Interval Coefficients
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In this research a new system identification algorithm is presented for obtaining an optimal set of mathematical models for system with perturbed coefficients, then this algorithm is applied practically by an “On Line System Identification Circuit”, based on real time speed response data of a permanent magnet DC motor. Such set of mathematical models represents the physical plant against all variation which may exist in its parameters, and forms a strong mathematical foundation for stability and performance analysis in control theory problems.

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Crossref
Publication Date
Mon Dec 26 2022
Journal Name
Arab Science Heritage Journal
العلاقات السياسية والعسكرية للإمارة العلوية في طبرستان مع الإمارة الطاهرية والصفارية والسامانية
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The stage of the establishment of the Alawite state in tabaristan was one of the most important stages in the history of the Shiite sect in Iran , from a political , religious and even military point of view ,

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