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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
Thu Dec 01 2011
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
التضخم في العراق واحتساب مساهمة المجاميع السلعية فيه للمدة 2004 - 2009
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The inflation phenomenon inherent to all economies in the world, including Iraq, and to find out the reasons for this phenomenon must be measured impact on the national economy, and is the index of consumer prices of the most common measure of inflation in order to find the means and the treatments needed and this can be reached through the study of the role of aggregates   Commodity and its impact on the general trend of cash inflation, in  Iraq for the period 2004 2009 to determine the groups lead to inflation in Iraq, where it emerged that the group rent is ranked first in the proportion of its contribution to the index of consumer prices, and food group is ranked second. The fuel and lighting group ranked third.

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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
Wed Dec 19 2018
Journal Name
Journal Of Planner And Development
التنمية الحضرية للمناطق السكنية غير الرسمية/العشوائية المتدهورة في مدينة بغداد
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Publication Date
Sun Oct 03 2010
Journal Name
Journal Of Educational And Psychological Researches
دور المرشـد النفســي في المؤسسـات التعليمية لوقاية الشباب من آفة المخدرات
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تتنوع الإمراض التي تدعى بإمراض العصر وتتعقد باستمرار والتوازي مع تقدم البشرية في مجالات التطور العلمي والاجتماعي ومختلف مجالات الحياة الأخرى .

فبالإضافة  إلى الإمراض الفيروسية والعضوية والنفسية هناك مرض تعاطي وإدمان المخدرات (الهاشمي ,  2002  ، ص1).

لم يعد خافيا على احد إن خطر الإدمان على الكحول والمخدرات والمؤثرات العقلية أصبح اليوم يهدد امن وسلامة العديد من دول العالم

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Publication Date
Sun Jan 01 2012
Journal Name
Journal Of Educational And Psychological Researches
معوقات استخدام الطرائق الحديثة لتدريس مواد اللغة العربية في المرحلة الإعدادية
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objective of this research is to identify some of the obstacles that face secondary school teachers of the Arabic language courses in using modern teaching methods in class.

The research focuses on secondary school teachers of the Arabic language courses at the central region of Nineveh Governorate for the school year (2008-2009). 30 teachers out of 792, were randomly chosen to apply the research tool upon.

To fulfill the objective of this research, the researcher first surveyed a number of teachers , he then identified four categories of obstacles; obstacles related to school administrative system and environment, the teacher, courses and pupils, and the nature of teaching method

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Publication Date
Sun Dec 27 2020
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
تفعيل دور وزارة التخطيط في تقييم الجدوى الفنية والاقتصادية للمشاريع المقترحة
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The success of any work requires the development of prior plans for the success of this work as well as providing the necessary sources of funds for the implementation of those plans, where the start of the research problem of delayed sending project proposals to the Ministry of Planning to do its job oversight in checking the technical and economic of those projects feasibility studies, has sought the researcher to the statement of need activating the role of the Ministry of planning in the study of projects before they are implemented and the trade-offs between important projects and projects the most important as they related to the usefulness of the community as well as the economic feasibility evaluation of them in terms of providin

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Publication Date
Wed Sep 01 2010
Journal Name
Journal Of Economics And Administrative Sciences
محاولة لصياغة برنامج تمويلي متكامل لدعم المشروعات الصغيرة والمتوسطة في العراق
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تعمل البنوك والمؤسسات المالية كوسيط مالي بين أصحاب المدخرات والودائع من جهة ومستخدمي هذه الأموال من جهة أخرى، وممارسة هذه الوساطة المالية بين الطرفين توضح العلاقة التي ينشأ عنها الائتمان، فالائتمان علاقة بين طرفين أولهما تزيد موارده على احتياجاته وهم (المدخرون) والثاني تزيد احتياجاته على موارده وهم (المقترضون)، وطبيعة العلاقة التي تنشأ بينهما تأخذ أحد شكلين: مباشر دون وساطة من أي طرف خارجي، أو غير مباشر عن

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Crossref
Publication Date
Thu Dec 08 2022
Journal Name
مجلة حمورابي
العقيدة العسكرية للمنظمات الارهابية الحرب اللامتماثلة في العراق عام 2014 انموذحا
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Publication Date
Sun Feb 07 2021
Journal Name
مجلة العلوم الاقتصادية والإدارية
تقويم كفاءة القطاع البلدي في محافظة الانبار باستخدام النهج اللامعلمي (DEA)
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The research aims to measure, assess and evaluate the efficiency of the directorates of Anbar Municipalities by using the Data Envelopment Analysis method (DEA). This is because the municipality sector is consider an important sector and has a direct contact with the citizen’s life. Provides essential services to citizens. The researcher used a case study method, and the sources of information collection based on data were monthly reports, the research population is represented by the Directorate of Anbar Municipalities, and the research sample consists of 7 municipalities which are different in terms of category and size of different types. The most important conclusion reached by the research is that there is a variation in the efficien

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Publication Date
Sun Sep 29 2019
Journal Name
مجلة متون
البلادة العاطفية لدى طلبة الجامعة في ضوء متغيري النوع والتخصص الدراسي
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هدفت الدراسة الحالية التعرف على البلادة العاطفية لطلبة الجامعة وكذلك التعرف على معنوية الفروق في البلادة العاطفية تبعاً لمتغيري: النوع (ذكور-اناث) والتخصص الدراسي (علمي –انساني) ، تآلفت عينة الدراسة من (400) طالب وطالبة موزعين بالتساوي حسب النوع والتخصص الدراسي تم اختيارهم عشوائيا من طلبة الجامعة، استخدمت الباحثة مقياس البلادة العاطفية من (اعداد الباحثة) وبعد تطبيق المقياس على عينة البحث واستخراج البيانات با

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