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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
Fri Dec 03 2021
Journal Name
مجلة تكريت للعلوم السياسية
نظرية الاعتراف في الفكر السياسي الغربي المعاصر: أكسل هونيث ونانسي فريزر انموذجا
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يعيش المجتمع العالمي أزمات بنيوية ونسقيه عميقة واختلالات وظيفية أسهمت في تنامي مظاهر الصراع المختلفة واشتداد تفجر الأزمات الهوياتية وتزايد الامراض الاجتماعية المقضة للعيش المشترك والمربكة لمظاهر التعايش والتآلف مع لجوء إنسان العصر الحالي الى التقوقع والاحتماء والانزواء تحت هويات ضيقة ونحل صغيره في مشهد يظهر مدى تراضي شبكة العالقات الاجتماعية على أداء وظائفها وأصبح عندها الاغتراب والقلق واللاتضامن والع

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Publication Date
Sat Jan 01 2011
Journal Name
جامعة بغداد - كلية التربية للبنات - قسم العلوم التربوية والنفسية
تقويم برامج الأنشطة الطلابية في جامعة بغداد من وجهة نظر إدارتها والطلبه
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Publication Date
Wed Sep 25 2019
Journal Name
Journal Of The College Of Education For Women
آليات التواصل اللغوية والبلاغية في الخطاب القرآني سور الطّور والنّجم والقمر إنموذجاً
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    لما كانت الوظيفة الأساسية للغة هي الوظيفة التواصلية ، أو التبادل الكلامي بين المخاطب والمستمع ، فكان لا بد لهذه الوظيفة من آليات – لغوية وبلاغية – يستعملها المتكلم أو المرسل للخطاب الأدبي لتوجيه ذهن السامع أو المخاطب نحو ما يطرحه من أفكار ، ورؤى ، واقناعه عن طريق التواصل ، بمضمون الخطاب واستلزام سرعة الانجاز ، وتأسيساً على ذلك جاء هذا البحث لبيان هذه الآليات في الخطاب القرآني متمثلاً في سور الطور

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Publication Date
Sun Oct 14 2018
Journal Name
Arab Science Heritage Journal
الاجراءات الإجراءات الإدارية والقانونية وسبل معالجتها لآزمة الأراضي في بغداد 1932-1938
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شكلت السيطرة العثمانية على العراق  حقبة تاريخية مهمة ، حيث وضعت فيها ركائز عدد كبير من الأنظمة الأدارية  فغدت  الأساس للتنظيمات  فيما بعد ومنها  الإجراءات الإدارية والقانونية وسبل معالجتها لآزمة الأراضي في بغداد1938-1932.

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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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Publication Date
Sun Jan 01 2012
Journal Name
Journal Of Educational And Psychological Researches
الصعوبات التي تواجه البحث العلمي في جامعة بغداد من وجهة نظر التدريسيين
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The problem of the study lies in the need for standing on the justifications, reasons and difficulties that face the scientific research matter at Baghdad university. The importance of this study lies in the fact of being scientific research one of the most important methods in developing the teaching members performance efficiency which contributes in teachers contact with the modern developments that emerge in work. That matter which reflexe on the educational process and the scientific production in their universities.

And the research goal is summarized in identifying the difficulties that is facing the scientific research at Baghdad university from the point of view of the lecturers, and also to ide

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Publication Date
Mon Dec 05 2022
Journal Name
Baghdad Science Journal
K-Nearest Neighbor Method with Principal Component Analysis for Functional Nonparametric Regression
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This paper proposed a new  method to study functional non-parametric regression data analysis with conditional expectation in the case that the covariates  are functional and the Principal Component Analysis was utilized to de-correlate the multivariate response variables. It  utilized the formula of the Nadaraya Watson estimator (K-Nearest Neighbour (KNN)) for prediction with different types of the semi-metrics, (which are based on Second Derivative and Functional Principal Component Analysis (FPCA))  for measureing the closeness between curves.  Root Mean Square Errors is used for the  implementation of this model which is then compared to the independent response method. R program is used for analysing data. Then, when  the cov

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Publication Date
Tue Oct 08 2002
Journal Name
Iraqi Journal Of Laser
Visible Enhanced Photodetector Made by Spray Pyrolysis
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Barium–doped TiO2 / n-Si photodetector was fabricated by spray pyrolysis exhibited visible enhancement responsivity profile with peak response at 600 nm flat response between 650 and 900 nm. The quantum efficiency was 30% and specific detectivity was 5x1012 W-1Hz1/2cm at peak response. The GaAlAs laser diode was used to estimate the rise time of the detector.

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Publication Date
Fri Jan 04 2019
Journal Name
Journal Of Planner And Development
تقييم الأحوال الاقتصادية للمعيشة في مدينة الموصل: السكان والمساكن للمدة 2004-2007
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Publication Date
Fri Aug 15 2008
Journal Name
اطروحة دكتوراه
الاقليمية الدولية الجديدة في عالم ما بعد الحرب الباردة : انموذج آسيا الباسفيك
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The thesis discusses the concept of the new international regionalism that emerged after the growing effects and repercussions of globalization with its economic, political and security dimensions after the end of the Cold War and the crystallization of a different international system dominated by the United States of America, so that the major countries and actors in the international system realize the danger of globalization and move towards adopting regional arrangements to contain the negative effects of globalization. The Asia-Pacific model was chosen as a model for the study.

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