Preferred Language
Articles
/
alkej-265
Experimental Study on the Effect of Insertion of Copper Lessing Rings in Phase Change Material (PCM) on the Performance of Thermal Energy Storage Unit
...Show More Authors

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.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Tue Aug 29 2023
Journal Name
حوليات اداب عين شمس
مقارنات اشتقاقية بين العبرية و العربية والارامية في عمل سعديا جاؤون
...Show More Authors

Publication Date
Tue Jun 01 2010
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
دور ومسؤولية مراقبي الحسابات في العراق تجاه الأفصاح الألكتروني للقوائم المالية
...Show More Authors

This research aims at shedding light on the electronic disclosure of the financial information under the condition of the development of this kind of disclosure all over the world , and its effect  on the job of auditing and accounting . It also aims to show the extent to which the observers of accounts are aware of their duties towards this kind of disclosure and to test the effect of some environment factors on the level of this awareness.

To achieve the aims of the research has been divided in to four parts. The first one deals with mathadolge of the research. The second parts is devoted to the theoretical aspect of the research referring to the notion of electronical, disclosure its features and effect on the auditing jo

... Show More
View Publication Preview PDF
Publication Date
Tue Nov 06 2018
Journal Name
Arab Science Heritage Journal
استخدام استخدام نظم المعلومات الجغرافية في الدراسات الاثارية ( تنقيبات جامعة الموصل).
...Show More Authors

GIS is characterized by great potentialeties to deal with huge geographical data and conclude what is necessary for it. It was very useful to get use of the potentialities of this system of GIS in the field of archaeology and to harvest very accurate results in a relatively short time, compared to the old archaeological methods.

View Publication Preview PDF
Publication Date
Thu Aug 27 2020
Journal Name
Arab Science Heritage Journal
المقومات السكانية والاقتصادية للمجتمع واثرها في تاريخ بغداد المعاصر 1940-1960م
...Show More Authors

       Our research, entitled(Population and economic determinants of society and its impact in the history of contemporary Baghdad 1940-1960), dealt with a number of historical facts and events of the social, demographic and economic

View Publication Preview PDF
Crossref
Publication Date
Wed Sep 01 2010
Journal Name
Journal Of Economics And Administrative Sciences
آليات حوكمة الشركات التي تؤثر في اتخاذ المدقق الداخلي للقرار الاخلاقي
...Show More Authors

اصبح لمجالس الادارة في الشركات دوراً حاسماً في تعزيز الحوكمة الفاعلة، كونها تتحمل المسؤولية النهائية عن نظم الرقابة الداخلية في شركاتها، ويلعب التدقيق الداخلي دوراً اساسياً في مساعدة تلك المجالس على القيام بمهمات الحوكمة. ولهذا يبذل مجمع المدققين الداخليين الامريكي جهداً كبيراً في توجيه اعضاءه ليكونوا متخصصين في اصول حوكمة الشركات وتحسين وتقوية اخلاقيات العمل وسلامة المنظمة.

لذا فإن ا

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Apr 01 2018
Journal Name
Journal Of Educational And Psychological Researches
Educational and psychological adjustment among hostel's students at Omer al-mokhtar University
...Show More Authors

Educational and psychological adjustment considered to be one of the effective and serious matters at people dealings and behaviors. Generally, psychological adjustment reflects positively on an individual mental health and their capability to be creative at their field. In contrast to those people who lack this feature. As for educational adjustment, it refers to the compatibility and harmony between an individuals and people around. Thus, these features should be available among students particularly those who stay in students' hostel since they live far from their families. The findings of study revealed that there is Educational and psychological adjustment between male and female. Besides, significant differences were showed

... Show More
View Publication Preview PDF
Publication Date
Wed Nov 28 2018
Journal Name
Arab Science Heritage Journal
العالم العالم ابن خلدون ( ت 808 هـ ) (نظريته في السياسة والعصبية)
...Show More Authors

Ibn Khaldun is one of the best Arab Muslims scientists who participated in establishing Arabic Muslims heritage in all different disciplines & directions specially in sociology, neurological & his political theories which showed the development of Arabic philosophy in all scientific disciplines specially his introduction

View Publication Preview PDF
Publication Date
Tue Apr 01 2008
Journal Name
Journal Of Educational And Psychological Researches
التربية النفسية والاخلاقية عند مسكويه في كتابه ( تهذيب الاخلاق وتطهير الاعراق)
...Show More Authors

أن الامم والشعوب لاتستطيع المحافظة على استمرار وجودها وتقدمها ورقيها، إلابفضل إعداد اجيالها المتعاقبة الاعداد السليم المتكامل ، وبقدر ما تحافظ الامم والشعوب على تربية هذه الاجيال للتمسك بدينها ، ومعتقداتها ، واخلاقها ، بقدر ما تحافظ على بقائها وعلو شأنها ، وكما فطنت الامم والشعوب إلى اهمية تربية اجيالها ، فطن اعداؤها الى ضرورة التخريب في جذور البناء الصحيح لتربية الاجيال ( فاطمة ، 1998، ص2).

... Show More
View Publication Preview PDF
Publication Date
Tue Jan 05 2010
Journal Name
Political Sciences Journal
دور المراكز البحثية في الحياة السياسية وصنع القرار السياسي الخارجي الامريكي
...Show More Authors

دور المراكز البحثية في الحياة السياسية وصنع القرار السياسي الخارجي الامريكي

View Publication Preview PDF
Crossref
Publication Date
Fri Feb 08 2019
Journal Name
Journal Of The College Of Education For Women
المتغیرات الجدیدة في سیاسة روسیا الاتحادیة تجاه منطقتي آسیا الوسطى والقوقاز
...Show More Authors

Federal Russia remains the central player in the space of post-Soviet Union,
particularly in the regions of Middle Asia and the Caucasus , which set standard for
the local transformations of the two regions.
The Russian concern continued about the shift of power in the
world, as long as Russia is concerned with limiting the action of the United States
in the area in which Russia sees as vital area to its national interests. Russia's
nationalists play a main role in reviving Russia's influence in Middle Asia as a vital
area and the natural ally of Russia, but without resorting to the old ways of using
the threat of military force.
The idea of the return of Russia as a superpower in the global arena in
Middle

... Show More
View Publication Preview PDF