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alkej-389
Transient Behavior Analysis for Solar Energy Storage in PCM-CFM Material Using Equivalent Heat Capacity Method as Storage Model
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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%.

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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
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            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

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Publication Date
Wed Dec 28 2022
Journal Name
Al–bahith Al–a'alami
Interactivity of iraqi daily newspapers sites an analytical study of the websites of al-mada,al-zaman.al-sabahand tareqal-shaab newspapers
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A study of interactivity in the Iraqi newspaper sites_ An analytical study of the website of Al-Mada, Al-Zaman, Al-Sabah and Tariq Al-Shaab newspaper sought to determine the amount of interactivity in the sites of Iraqi newspapers that have been published since 2003, which consists of (15) newspapers according to the statistics of the Iraqi Books and Documents House.

and the researcher conducted an analytical survey on these sites, and the percentage of interactivity in general was weak, not more than (47.1%), and this weakness in interactivity contributed greatly to the decline in surfers of the websites of those electronic newspapers.

The highest aggregate rate of the research sample was in the simple interactive tools

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Publication Date
Tue Nov 13 2018
Journal Name
Arab Science Heritage Journal
التحديات التحديات المعاصرة للثقافة الإسلامية دراسة في الصورة النمطية المتبادلة للسلام وللحرب بين الإسلام والغرب
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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

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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
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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

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Publication Date
Wed May 03 2017
Journal Name
Journal Of Physical Education
تأثير تمرينات علاجية في تحسين مرونة الجذع وانعكاسها على آلام اسفل الظهر لذوي الاعاقة البدنية
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Publication Date
Fri Apr 12 2019
Journal Name
Journal Of Economics And Administrative Sciences
The Compatibility between leadership of empowerment and organizational learning abilities and their reflection on knowledge capital Applied research at Wasit University
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The current research aims at: - Identifying the role played by the leadership in empowerment and organizational learning abilities and their reflection on the knowledge capital, and the extent to which these concepts can be applied effectively at Wasit University. The problem of research .... In a series of questions: The most important is that the dimensions leadership empowerment and distance learning organizational capacity correlation relationship and impact and significant statistical significance with the capital knowledge.

     To understand the nature of the relationship and the impact between the variables, leadership was adopted by empowerment as the fir

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Publication Date
Sat Feb 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
Application Effect of the Conflict Management Strategies On Increasing Workers Productivity at the Electricity Company (IGEC) (Field Study Irbid Governorate)
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Research aimed to explore the Application Effect of the Conflict Management Strategies by the managements to solve conflict between and inside the conflicted parties within (IGEC) to increase the productivity of the workers. To collect data, 110 questioners had been distributed among managers and heads of departments of all managerial levels, 102 answered questioners regained, 5 of them were disqualify for statistical analytic, only 97 were taking in consideration   for statistical analysis presenting 93% of the retained number.

SPSS Program supported with a group of statistical tools, had been used for analysis purposes such as Kronbach Alpha test to assure the validity & stability of the t

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Publication Date
Fri Nov 15 2024
Journal Name
الاستاذ
اثر انموذج التعلم الخبراتي ل روبين في مادة الفيزياء والدافعية الابداعية لطلاب الصف الرابع العلمي
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الملخص : يهذف البحث التعرف على اثر آنموذج التعلم الخبراتي (لروبين) في مادة الفيزياء والدافعية الإبداعية لدى طلاب المرطة الإعدادية, وذلك بالتحقق من الفرضية الآتية: • لا يوجد فروق ذات دلالة إحصائية عند مستوى (0.05) بین متوسط درجات المجموعة التجريبية التـي درست وفق إستراتيجية التعلم الخبراتي (لروبين) ومتوسط درجات المجموعة الضابطة التي درست وفق الطريقة الاعتيادية في مقیاس الدافعية الابداعية. استخدم الباحثون التص

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Publication Date
Mon Mar 07 2022
Journal Name
Journal Of Educational And Psychological Researches
The Level of Administrative Work Quality of Private Schools Principals at Southern Governorates of Palestine form the Teachers Point of View
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The study aimed at identifying the level of administrative work quality of private Schools principals at Southern Governorates of Palestine from the teachers' point of view in their schools. To achieve the objectives of this research, a questionnaire was prepared by the researcher consisted of (28) items. It was applied to a sample of (350) teachers. The researcher adopted the descriptive-analytical approach. The results of the study showed that the degree to which principals of private schools in the southern governorates of Palestine practice Administrative Work Quality from the viewpoint of their teachers was very high, with relative weight (85.00%). The results also showed that there are statistically significant differences at the l

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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
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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

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