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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
Mon Sep 03 2018
Journal Name
Al-academy
Perspective Cognitive Warm-up Voice
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      The aim of this research is to find out about the methods used by the teachers of the subjects (choir, voice training, singing groups) used to warm up in voice training. In the Department of Music of the Faculty of Fine Arts University of Baghdad. The limits of this research were for the academic year (2017-2018). Explanation in the theoretical framework of warm-up types The first part of the body warms the body in terms of relaxation, body moderation, head rotation, tongue exercises, mouth opening, facial mask movements, yawning.The second course will warm up the sound exercises warm up the sound through different ladders (diatonic and chromate), and ladder accordions.And the third topic warm up the impris

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Publication Date
Thu Nov 12 2020
Journal Name
Arab Science Heritage Journal
عبد الحميد العلوجي وإسهاماتهُ في التراث
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The codification of the social history of the city of Baghdad will be filled with an inherited folklore that has been descended to it from the previous generations with all its tales of folk tales, metaphors, parables, crafts and industries. Immortal

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Publication Date
Sun Dec 02 2018
Journal Name
Arab Science Heritage Journal
المضامين الاخلاقية والقيمية في فلسفة التربيةالمضامين
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         The moral implications and value in the philosophy of education are one of the most important topics that should be well worth seeking out, especially in our time because of its great importance in the upbringing of the emerging formation, guidance and evaluation within the system or graded him the values ​​of the society in which they live.

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Publication Date
Tue Jan 29 2019
Journal Name
Arab Science Heritage Journal
طرق البحث العلمي في مؤلفات الرازي
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نسب أغلب مؤرخي العلم الإنساني الطرق التي إتبعت في كتابة المنهج العلمي الصحيح ، في كافة العلوم و المعارف ، إلى العصر الحديث . و قال آخرون ان العقل البشري ، سواء في الأزمنة القديمة أو الحديثة ، هو واحد لا يمكنه التفكير أو العمل إلا بوجود منهج معين يسير عليه فكره و فعله (1) ، مطلقين عليه تسمية المنهج التلقائي . و كما هو واضح من التسمية يمكن وصفه بأنه منهج يفتقر إلى الإدراك و الشعور . و يطبق هذا المنهج الغالبية ا

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Publication Date
Sun Apr 07 2013
Journal Name
Journal Of Educational And Psychological Researches
تشخيص الاطفال التوحديين في رياض الاطفال
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Developing disorders or ingeneral disability considered one of infortant cases which socities faces as a case with several a spects that may lead to disability . the movement of growth anf developing in the society thus the gardiauship of abnormal individuals became insisting issue which has social and human necessity .

The children of autism considered as special categories that guardian ship and care started of them inhoticeble image at the last time .

Hence, the researcher interested in this problem that made her studying it the study aimed to educte the child of autism that exist in kindergarten .the resrarcher depended on (Adel Abdullah) test for child autism that consists o

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Publication Date
Wed Oct 04 2023
Journal Name
Arab Science Heritage Journal
التجارة في فكر عبد الاله حافظ
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The study consisted of an introduction، two chapters and a conclusion

   The first، tagged topic (: His lineage، birth، and family)، traces the lineage، birth، and family of Abd al-Ilah Hafez.

The second topic، which came under the title (The Role of Abd al-Ilah Hafez in the printing of currency)، was concerned.

 The study relied on a large number of unpublished documents، foremost of which are the documents of the Central Bank of Iraq. It contained a lot of information about its administrative activity، its positions، orders and plans in this direction.

 The House of Books and Documents is considered Al-Manhal، which is indispensable for any research to study the royal his

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Publication Date
Sun Jul 03 2011
Journal Name
Journal Of Educational And Psychological Researches
عمالة الاطفال في العراق " الاسباب والحلول "
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لقد عرفت بلادنا ظاهرة ( اطفال الشوارع ) والتي تشمل عمالة الاطفال والمتشردين والمتسولين ، فتحولت من مشكلة على نطاق نسبي الى ظاهرة واسعة جداً تتضمن المخاطر المصاحبة لها ، إذ إنها ظاهرة منتشرة جداً في جميع المدن العراقية تصف في كثرة انتشارها في المناطق المليئة بالسكان .

إن ظاهرة عمالة الاطفال والتي ينصب عليها إهتمامنا في هذا البحث تشير الى نشاطات تقع خارج نطاق قوانين العمل وشروطه الاجتماعية ،

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Publication Date
Mon Nov 12 2018
Journal Name
Arab Science Heritage Journal
شق لفظة (شقَّ) في القرآن الكريم
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Through tracingthe term “derivation” in the Holy Quran, I found that the word derivation varies and graduates in meaning from one form to another according to what has been mentioned in the Quranic context. In order to show that variation and graduation, we trace it in three axes:

The first axis (openness): the term “derivation” graduates from the meaning of openness and opening in its broad meaning to partial openness.

The second axis (the dispute): the term “derivation” participated with the general and private meaning, i.e. from hostility to antipathy.

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Publication Date
Sun Dec 02 2007
Journal Name
Political Sciences Journal
بعض المعادلات في اشكالية الانتخابات العراقية
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بعض المعادلات في اشكالية الانتخابات العراقية

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Publication Date
Sun Jul 03 2005
Journal Name
Political Sciences Journal
مستقبل مؤسسات المجتمع المدني في العراق
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مستقبل مؤسسات المجتمع المدني في العراق

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