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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 Sep 01 2018
Journal Name
مجلة الأستاذ
تباين نسبة الاعالة في محافظة بغداد وعلاقتها بالمتغيرات الاجتماعية للسكان لعام 2016
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The subject of population support is one of the most important topics in the geography of the population as it shows the amount of burden on the workforce in society and reflects the balance or

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Publication Date
Sun Feb 09 2025
Journal Name
Journal Of Baghdad College Of Economic Sciences University
توظيف القدرات المعرفية الدينامية لتحقيق تنافسية الاعمال بحث تطبيقي في مصانع الالبان
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يهدف البحث الى قياس مستوى ارتباط وتأثير القدرات المعرفية الدينامية في تنافسية الاعمال، وتكونت العينة من (155) فردا في اربعة مصانع للالبان في بغداد وهي (ابو غريب، والزراعة، والحلال، وعيون الرافدين) اذ تمثل مجتمع البحث من اصحاب المصانع، والمديرين والعاملين في السيطرة النوعية والبحث والتطوير والمهندسين والفنيين والعاملين ذوي الخبرة في صناعة الالبان. وجرى تحليل البيانات واختبار الفرضيات باستخدام الادوات الإحصا

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Publication Date
Tue Dec 31 2013
Journal Name
Journal Of The College Of Languages
إيقــاع النفـــس الشـــاعـرة في شعر الشاعر الصّقلي علي بن عبد الرحمن البلـَّنوبي
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درست الباحثة البنية الإيقاعية عند الشاعر الصقلي

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Publication Date
Fri Jan 04 2019
Journal Name
Journal Of Planner And Development
نمذجة توزيع المدارس الابتدائية في مدينة الفلوجة باستخدام نظم المعلومات الجغرافية G.I.S
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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
Mon Oct 15 2018
Journal Name
Arab Science Heritage Journal
نحو نظام نحو نظام لغوي عربي متوازن في المساواة بين الرجل والمرأة
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We must live in an era dominated by the call for equality between men and women, in which the voices of advocates of gender integration were heard. After women opened their doors to compete with their brother, Knowledge, and culture in the various forms of life, language as a science of the time and knowledge of the other had to match this reality and express the most accurate expression of this task

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Publication Date
Thu Dec 01 2022
Journal Name
اكليل للدراسات الانسانية
الخطأ المضمر في نطاق المسؤولية الطبيةدراسة معززة بالقرارات القضائية (فرنسا-العراق) انموذجا
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يقوم الخطأ المضمر على فكرة مبناها استنتاج الخطأ من وقوع الضرر، منشئاً بذلك قرينة قانونية بسيطة للمدعي (المضرور) تعفيه من اثبات خطأ المدعى عليه (المسؤول)، وهذا الافتراض في الاساس فكرة قضائية وجدت لمساعدة المضرور في الحصول على التعويض في حالة عدم تمكنه من تحديد خطأ المسؤول ، الا انه افتراضٌ قابلٌ لإثبات العكس من خلال نفي اي خطأ صادر عن المدعى عليه ، ويمكن نفيه ايضاً بإثبات انقطاع السببية بين الخطأ المضمر والضرر

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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
Tue Oct 11 2022
Journal Name
College Of Islamic Sciences
Hanbali's approach to building long and short travel provisions with issues attached to their provisions
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The problem with research lies in hiding the Hanbali approach in building long and short travel provisions, as well as hiding some provisions relating to short travel that are not provided for by the jurists of Hanbali (in their books).

The research aims to demonstrate the approach and standards on which they based the long and short travel provisions, as well as to reflect the provisions of some of the issues that are silent on long and short travel, with evidence and significance.

The research included a preface and two researches, the researcher in the preface talked about the reality of long and short travel, in the first research on the approach of ha

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Publication Date
Tue Apr 01 2008
Journal Name
Journal Of Educational And Psychological Researches
الطفولة في العراق بين جهود التنمية وتحديـــات الوضــــع الراهــن قســم الخدمـة الاجتماعيـة
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      اهتمت المجتمعات العالمية في الآونة الأخير بفئة الأطفال ، ورعاية الطفولة وذلك لما لها من أهمية كبيرة في مستقبل المجتمع ، وتنميتة وتقدمه . لأنها يعتمد عليها في تقدم وتطور المجتمع فـي جميع المجالات الاقتصادية والاجتماعية والثقافية . ومن هنا ارتبطت الطفولة بالحياة برباط عضوي فالأطفال براعم الحياة ومع هذه البراعم تستمر الحياة لذلك اهتمت دول العالم بوضع البرامج وعقد المؤتمرات من اجل النهوض

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