Preferred Language
Articles
/
alkej-389
Transient Behavior Analysis for Solar Energy Storage in PCM-CFM Material Using Equivalent Heat Capacity Method as Storage Model
...Show More Authors

A paraffin wax and copper foam matrix were used as a thermal energy storage material in the double passes air solar chimney (SC) collector to get ventilation effect through daytime and after sunset. Air SC collector was installed in the south wall of an insulated test room and tested with different working angles (30o, 45o and 60o). Different SC types were used; single pass, double passes flat plate collector and double pass thermal energy storage box collector (TESB). A computational model based on the finite volume method for transient tw dimensional domains was carried out to describe the heat transfer and storage in the thermal energy storage material of collector. Also, equivalent specific heat method was employed to describe the heat storage and release in the mushy zone. Experimental results referred to an increase in thermal conductivity of paraffin wax that supported by copper foam matrix more than ten times. While the ventilation effect was still active for hours after the sun set, depending on the heat storage amount. Maximum ventilation mass flow rate with TESB collector was recorded with value equals to 36.651 kg/hr., when the overall discharge coefficient that was calculated for the system equals to 0.371. Experimental results showed that the best working angle range was 45~60o, and the highest air to the collector approaching temperature appeared to the double passes flat plate collector. Results gave greater heat storage efficiency of (47)% when the maximum solar radiation was 780 W/m2 at 12.00pm, while the energy summation through duration charge time was 18460 kJ. Computational results, depending on the equivalent heat capacity method for heat storage or release from phase change material that supported by copper foam matrix, showed the behavior of paraffin wax melting and solidification situation through periodic for charge and released heat from the solar collector. Also, these results gave agreement approaching the experimental results for the heat storage in the combined heat storage material, with standard error of 16.8%.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Sun Oct 04 2009
Journal Name
Journal Of Educational And Psychological Researches
أثر إستراتيجية الملخصات القبلية على التحصيل الدراسي لطالبات الصف الثالث المتوسط في مادة التربية الأسرية
...Show More Authors

لقد أدت التطورات العلمية والتقنية وتطبيقاتها العملية في مختلف ميادين الحياة بشكل عام وميدان التربية والتعليم بشكل خاص إلى ظهور تغيرات في البناء التعليمي وطرائق التدريس بصيغتها الحديثة التي تنسجم في مجملها وروح العصر مما دعى المؤسسات التربوية والتعليمية وبإيعاز إلى الباحثين والمهتمين بهذا الميدان الى ضرورة متابعة الاتجاهات الحديثة ونواحي التجديد لمحتوى العملية التعليمية فيما يتعلق بالمجالات المعر

... Show More
View Publication Preview PDF
Publication Date
Thu Jan 16 2020
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
دور معايير التدقيق الدولية في تعزيز خدمات التأكيد: بحث تطبيقي على عينه من مراقبي الحسابات
...Show More Authors

  

View Publication Preview PDF
Publication Date
Sun Apr 01 2012
Journal Name
Journal Of Educational And Psychological Researches
أثر أنموذج وودز في تصحيح المفاهيم الجغرافية ذات الفهم الخاطئ لدى طلاب الصف الأول المتوسط
...Show More Authors

The present study aims at knowing the effect of Woods' model in correcting the geographical missUnderstanding for first stage students. In order to realize the objective of this study, the researcher used an experimental design with partial adjustment which is experimental group with another control group. The research is confined to the first four chapters of the boon of the principles of geography to be studied for the first stage in the academic year (2010/2011) in Iraq. The researcher chooses purposely the chose a staple form the first stage in Hay Al-Jama'a School for boys, in order to apply the experiment. The total number of the sample was (60) students who were distributed randomly as (30)per group. The researcher matched two gro

... Show More
View Publication Preview PDF
Publication Date
Wed Oct 24 2018
Journal Name
Journal Of Planner And Development
الآليات التخطيطية لتوفير خدمات البنى التحتية في قطاع الإسكان (مدينة الكاظمية المقدسة إنموذجاﹰ )- محلة 413،405،407
...Show More Authors

View Publication Preview PDF
Publication Date
Sun Apr 02 2017
Journal Name
Journal Of Educational And Psychological Researches
بعض الاضطرابات السلوكية والانفعالية والانفعالية وعلاقتها بالاستعمال المفرط للألعاب الالكترونية لدى التلاميذ في المرحلة الابتدائي
...Show More Authors

سعى البحث الحالي الى التعرف على بعض الاضطرابات السلوكية والانفعالية وعلاقتها بالاستعمال المفرط للالعاب الالكترونية لدى تلاميذ المرحلة الابتدائية, إذ يواجه التلاميذ مشكلات سلوكية عديدة ،تظهر من خلال تعاملهم مع اقرانهم في البيت او في المدرسة والتي قد تتطور عند بعضهم وتتحول الى اضطرابات نفسية،مما يؤدي بهم الى ضعف التعلم وسوء التوافق في حياتهم المدرسية ويصبحون عُرضة للا صابة بالامراض النفسية ،إذا لم يتم تشخ

... Show More
View Publication Preview PDF
Publication Date
Sun Jan 04 2015
Journal Name
Journal Of Educational And Psychological Researches
The Skills of Time Management and Causes of Wasting The Time of Heads of Department at University of Baghdad From The Staffers’ Point of View
...Show More Authors

            Time is very important in educational institutions. It is also one of our contemporary problem ‚as time is a clear – cut and limited factor‚ it demands that administrators should monitor it by administering and monitoring the principles of time.

Hence‚ the researcher attempts to identify the skills of administrating time and the reasons that cause the waste of time of the Heads of Departments at university of Baghdad.

Significance  of the research:

Time is very important to all educational administrators and one of them is the institutions of Higher education. One of the

... Show More
View Publication Preview PDF
Publication Date
Mon Jan 02 2017
Journal Name
Journal Of Educational And Psychological Researches
تقويم جودة مهارات التدريس لدى مدرسي الرياضيات في المرحلة الإعدادية الفرع العلمي من وجهة نظرهم
...Show More Authors

   Research aims at evaluating the quality of the teaching skills of math teachers in junior high / scientific branch  from their point of view.

The researchers prepared for this purpose a quality of teaching skills standards questionnaire, It consisted of 72 items distributed on four axis, The research sample was 200 teachers The researchers used statistical methods: the arithmetic mean, standard deviation, variance test, test Shiva  , The results showed a statistically significance difference Attributed to the qualification  variable  in the second  axis (Planning for teaching topics) And the absence of statistical difference function,

... Show More
View Publication Preview PDF
Publication Date
Wed Nov 14 2018
Journal Name
Arab Science Heritage Journal
التحديات التحديات المعاصرة للثقافة الإسلامية دراسة في الصورة النمطية المتبادلة للسلام وللحرب بين الإسلام والغرب
...Show More Authors

Islamic Culture face many challenges Such as، Secularism، westrenism، globalism and Colonialism under current attempts For western States and united states of America to dominate on world and Confront all her Opponent Polaris it be clear when U. S. A. Occupied Afghanistan and Iraq and Threatened many Arabic and Islamic States

View Publication Preview PDF
Publication Date
Fri Jan 01 2016
Journal Name
مجلة جامعة كربالء العلمية
دراسة شكليائية ونسجية للكلية في الساحف )أبو بريص( وزغة خشنة الحراشف Cyrtopodion scabrum (Heyden, 1827)
...Show More Authors

Preview PDF
Publication Date
Sun Feb 03 2019
Journal Name
Journal Of The College Of Education For Women
Speech Acts Through Ages - A Comprative Study between Traditional and Modren Approches
...Show More Authors

This study has been developed axes of the search, including: Search (deliberative) language and idiomatically, and Description Language (b social phenomenon), and the definition of the theory of (acts of speech), and discussed the problem of the conflict between tradition and innovation, as defined objectively have a target aimed at reviving the deliberative thought when Arab scholars , and the balance between the actual done Arab and Western rhetoric, but Meet in intellectual necessity, a sober reading that preserve the Arab language prestige, and its position in the light of the growing tongue Sciences, as long as we have inherited minds unique, and heritage huge able to consolidate the Arab theory lingual in linguistics.

View Publication Preview PDF