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 Nov 29 2005
Journal Name
اطروحة دكتوراة
Неполнозначные глаголы в современном русском языке: состав и функционирование
...Show More Authors

ВВЕДЕНИЕ Уровневая структура языка обусловила основные направления изучения язы¬ковых единиц в соответствии с их местом в языковой стратификации. Тра-дицион¬ные подходы определялись теми особенностями языковых единиц, ко-торые укладывались в рамки описания в соотношении с единицами их класса. Однако развитие лингвистической науки, формирование современных на¬правлений и подходов к изучению языка в с

... Show More
Publication Date
Tue Dec 30 2025
Journal Name
حوليات أداب عين شمس
الاحتجاج بالشاهد الديني والأدبي في شعر محمد مهدي الجواهري
...Show More Authors

View Publication
Crossref
Publication Date
Sun Dec 31 2023
Journal Name
Lark
بلاغة النسق في قصة النبي سليمان (ع) بالقرآن الكريم
...Show More Authors

View Publication
Crossref
Publication Date
Sat Dec 01 2012
Journal Name
Journal Of Engineering
Development an Anomaly Network Intrusion Detection System Using Neural Network
...Show More Authors

Most intrusion detection systems are signature based that work similar to anti-virus but they are unable to detect the zero-day attacks. The importance of the anomaly based IDS has raised because of its ability to deal with the unknown attacks. However smart attacks are appeared to compromise the detection ability of the anomaly based IDS. By considering these weak points the proposed
system is developed to overcome them. The proposed system is a development to the well-known payload anomaly detector (PAYL). By
combining two stages with the PAYL detector, it gives good detection ability and acceptable ratio of false positive. The proposed system improve the models recognition ability in the PAYL detector, for a filtered unencrypt

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Oct 16 2026
Journal Name
Арабистика Евразии
بين اللغة والوطن قراءة في قصة خواجة نزار لموشيه سميلانسكي
...Show More Authors

يهدف هذا البحث إلي معرفة معنى اللغة وتجلياتها في نتاجات الاديب الإسرائيلي الأكثر جدلا في القرن العشرين، إلا وهو الاديب "موشيه سيملانسكي". فقد طغت صورة العربي في الكثير من أعماله الأدبية وتبوات مكانا واضحا، وكانت النظرة تجاهه، نظرة واضحة أيضا، فصورته لم تتغير بتغير الظروف والاتفاقيات، بشكل يتناسب وهذه الظروف، وإنما بقيت تراوح مكانها، ولم تتبدل بنظرة احترام على الأقل، بل على العكس من ذلك، فهناك بعض المطالبات

... Show More
View Publication Preview PDF
Publication Date
Sun Dec 01 2024
Journal Name
مجلة دراسات دولية
توظيف خيارات استراتيجيات مكافحة التطرف العنيف في العراق وافاقها المستقبلية
...Show More Authors

أن للتطرف العنيف أسباب متنوعة تقف وراء ظهوره وتمدده في دول العالم المختلفة على نطاق واسع، إذ إن لكل بيئة ظروفها وخصوصياتها الكلية والفرعية التي تسهم في تعزيز القدرة التأثيرية للسلوكيات العنفية في إطار مجتمع ما، لاسيما إذا علمنا إن التطرف العنيف المؤدي الى الإرهاب كسلوكيات عنفية متطرفة مدمرة للبناء المجتمعي ما كان ليستمر لولا وجود بيئة حاضنة وظروف تساعد في انتشاره واستمرارية قدراته التأثيرية في البناء السي

... Show More
View Publication Preview PDF
Publication Date
Wed Apr 01 2015
Journal Name
Journal Of Educational And Psychological Researches
التفكير المزدوج ودوره في تعزيز روح التسامح لدى طلبة الجامعة
...Show More Authors

    Sought Current search to know the concepts of modern literature theoretical educational, psychological and social are thinking double and tolerance and the definition of them in the theoretical frameworks of religious, social and psychological to clarify their role in life in general and in university life private and to understand their respective roles in the promotion of the other, and research has included a chapter first to identify the importance and the objectives and terms Search in detail, and a chapter of a second frameworks and theoretical literature of concepts ranging from religious heritage in Islam and other religions, especially the concept of tolerance, then look at social, psy

... Show More
View Publication Preview PDF
Publication Date
Sun Jan 08 2023
Journal Name
الاستاذ
توظيف الألفاظ والتراكيب من السياق القرآني في شعر هيثم الزبيدي
...Show More Authors

Publication Date
Mon Jan 01 2018
Journal Name
مجلة كلية التربية للبنات/ مجلة علمية ثقافية تربوية محكمة
الاتجاهات الموضوعية للبحوث المنشورة في مجلة كلية القانون / جامعة بغداد
...Show More Authors

Publication Date
Wed Dec 01 2010
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
إنشاء جائزة عربية للجودة في قطاع التعليم العالي: رؤيــة عراقيــة
...Show More Authors

  IF we called twentieth century, the century of productivity and information revolution, the suitable address for twenty-first century is (( The quality century )) .

The research aims to initiate Arabic prize for quality to apply concepts and strategies of total quality management at Higher education sector, which is a vital sector and it may be the most importance sector because it provide efficient human manpower working at all other sectors.

The suggested prize take in consideration the specialty of this sector, and when we apply perspectives of this prize this will promote Arabic universities performance as well as the quality of graduates.

The importance of this research due to the necessity of this pri

... Show More
View Publication Preview PDF