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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
Wed May 10 2017
Journal Name
Journal Of The College Of Languages (jcl)
TITTEL DER FORSCHUNG : DIE WICHTIGKEIT DER SPRACHFERTIGKEITEN BEIM ERLERNEN DER DEUTSCHEN SPRACHE UND UNTERRICHTSMETHODEN FÜR DEUTSCHUNTERRICHT
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Jeder Lernende, der in der Fremdsprache Deutsch kommunizieren möchte, wird sich auch mit der deutschen Aussprache beschäftigen (müssen). Wer eine gute Aussprache hat, wird nicht nur oft und zu Recht bewundert, er hat es auch leichter, die deutsche Sprache zu verstehen, und er wird gut verstanden. Aussprachefehler beeinträchtigen die Kommunikation, sie führen zur Unverständlichkeit von Namen, Wörtern und Äußerungen oder Mißverständnissen, sie bewirken Ermüdung und Konzentrationsverluste und beeinträchtigen die Sprachverarbeitung durch Assoziationen und Emotionen, die beim Hörer entstehen können.’’[1]

Diese vorliegende Forschung befasst sich mit der Wic

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Publication Date
Fri Sep 25 2026
Journal Name
Misan Journal For Physical Education Sciences
تأثير اسلوب تدريب المقاومات المرنة في تطوير القوة المميزة بالسرعة والتحمل الخاص للاعبي كرة القدم للصالات
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ملخص البحث: يعد اسلوب تدريب المقاومات المرنة واحد من اساليب تدريب القوة العضلية فهو النظام الذي يتم من خلاله استخدام تمرينات يتم ادائها ضد مقاومات متغيرة مثل الحبال المطاطية او اشرطة الساندو، ويمتاز هذا الاسلوب بتغير الشدة خلال اداء التمرين الواحد اي ان كلما تم مط الحبل المطاطي ازدادت مقاومته وبالتالي فان اللاعب يستخرج قوته اكثر كلما اقترب الى مركزية الحركة في التمرين وهذا هو جوهر الاختلاف بينه وبين استخد

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Publication Date
Thu Dec 31 2020
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The impact of voluntary corporate disclosure on tax planning: An applied analytical research of a sample of Iraqi private joint-stock companies
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In recent years, the attention of researchers, governments and international non-governmental organizations has focused on the aggressive practices adopted by companies with the aim of evading the tax burden or from paying the tax obligations imposed on them by law, as the results of these practices are negatively affected by tax revenues. And that companies are part of the society in which they work, and they have rights and obligations, including paying taxes. The research community is the Iraqi private shareholding companies, and the research sample was 4 companies within the private sector and in the field and finance - banking, insurance, industrial and service, which are Ashur Bank, Al-Ahlia Insurance Company, Baghdad Soft

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Publication Date
Thu Jan 01 2009
Journal Name
مجلة قبس العربية
مشكلة ضعف طلبة اقسام اللغة العربية في كليات التربية الاساسية بالاعراب من وجهة نظر التدريسيين والطلبة
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Publication Date
Tue Dec 01 2009
Journal Name
Journal Of Economics And Administrative Sciences
The Effect of Administrative Accounting Functions on the Practices of the Higher and Central Administrations of the Economic Unit "An Applied Study on Joint Stock Companies"
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Strategy Descrtibes How an Organization Matches its own Capabilites With Opportunities in Environment , in Order to Accomplish its Overall Objectives , So That The Organization is Considering Responding to Challenges by Adopting one or More of Strategies, Like Differentioning its Product, or Achieving Cost Leadership.

The Key Role of Management Accountant is to Evlaute The Successful it Has Been in Implementing Organization Strategy.

This Research Target to Explain The Key Role of Management Accountant in Evaluate of  Organization Strategy. by Strategic Analysis of Operating Income From Specific Sources Such as Cost Savings and Growth in Stead of Emphasizing Only The Aggrega

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Publication Date
Tue Aug 31 2021
Journal Name
معرفة
نسبة مساهمة التدفق النفسي في بعض مهارات الجمناستك الإيقاعي و فعالية رمي الثقل بالساحة و الميدان
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Publication Date
Mon Apr 03 2023
Journal Name
Journal Of Educational And Psychological Researches
Typical Effect of Flower and Coscroff on Expressive the Development of Lateral Thinking among the Literary Fifth Grade Students
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Abstract

The current research aims to identify the typical effect of Flower and Coscroft on expressive performance and the development of lateral thinking among literary fifth-grade students. To achieve the research objective, the researcher chose a sample of (90) female students from the fifth literary grade, with two experimental groups and a control group. The research groups are of six subjects. The research found that the two experimental groups have more expressive performance than the control group. Students of the first experimental group outperformed the students of the second experimental group in expressive performance and lateral thinking tests. In light of the findings of the research, the researcher

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Publication Date
Sun Nov 11 2018
Journal Name
Arab Science Heritage Journal
تدهور تدهور التجارة وانخفاض عائدات الضرائب في ايران(1) خلال عهد الشاه سلطان حسين ( 1694-1722).
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The weakness of the central rule at the reign of Shah Sultan Hussain who is regarded as the last Shah who governed the Safawi state near to its falling at the hold of Afghan in 1722 which is the main and the real factor for the economic collapse. The tribes of trade have faced stealing and robbery actions which have been compressed to a very big extent. This action was not the responsibility of Shah alone,

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Publication Date
Sat Jan 02 2021
Journal Name
Journal Of The College Of Languages (jcl)
The morphological and syntactic grammes of the category of temporality: Морфолого-синтаксический состав категории темпоральности в русском языке
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The present paper discusses morphological and syntactic structures of time in Russian language. The morphological and syntactic structures are considered part component of time category in Russian language.

The morphological categories of time are formed through a various types of expressions .Tenses generally express time relative to the moment of speaking. In some contexts, however, their meaning may be relativized to a point in the past ,present or future which is established in the discourse .Some languages have different verb forms or constructions and that are opposed in meaning not in syntactic category. Hence, the present study traces and compares the syntacti

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Publication Date
Sun Mar 20 2005
Journal Name
الجامعة المستنصرية / كلية التربية الأساسية
اثر استخدام استراتيجية بوليا واستراتيجية التمثيل المعرفي في تحصيل واستبقاء مادة الرياضيات لدى طلبة المرحلة المتوسطة
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