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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 Dec 02 2018
Journal Name
Arab Science Heritage Journal
عبدالحميد الثاني والإستيطان الصهيوني في الولايات العربية من مشرق الوطن العربي مناطق الأختيار للإستيطان فلسطين والعراق
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ترك السلطان عبدالحميد الثاني بصماتهُ على أخاديد الزمان وعلى خارطة المشرق العربي الخاضع للسيطرة العثمانية أنذاك ، لكونهُ أهم شخصية أسلامية غير عربية واجهت الخطر الصهيوني ومحاولاتهم الإستيطانية في مشرق الوطن العربي ، على الرغم من صعوبة الظروف التي كانت تمر بها الدولة العثمانية داخليا ً وخارجيا ً، بما فيها من أطماع اقتسامها بين الاوربين ولذا سموها بالرجل المريض .

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Publication Date
Wed Nov 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
The role of administrative supervision scope and the single window to increase the efficiency of investment (Case study: Sudanese Ministry of Investment)
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Investment drives the wheel of the development of different developed and developing countries. Sudan is a model for a developing country facing a lot of difficulties in the field of both local and foreign investment. The present study was focused on the problem of poor diversification and efficiency of both local and foreign investment in Sudan. Also, it clarified the important role of administrative supervision to strengthen the efficiency of investment, taking the experience of the Sudan as a model. The researchers used the well-known descriptive and analytical tools (questionnaire, interview, observation) to complete this study. A well designed questionnaire was used. It included all questions that could cover all aspects of

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Publication Date
Sun Jan 01 2023
Journal Name
مجلة المستنصرية لعلوم الرياضة
الثقافة التنظيمية لدى اللجنة الأولمبية الوطنية العراقية من وجهة نظر أعضاء الهيئات الإدارية في الاتحادات الرياضية
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Publication Date
Thu Mar 01 2007
Journal Name
Journal Of Economics And Administrative Sciences
الإستراتيجية: المفهوم وإشكالية المصطلح دراسة تحليلية مقارنة لأراء عينة من الأكاديميين والمديرين في المملكة الأردنية الهاشمية
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المُستلخص:

      يتناول هذا البحث موضوعاً يتركز في جانب تحديد مفهوم ومحتوى الإستراتيجية. وقد أشارت الأدبيات إلى عدد من المحاولات التي هدفت إلى تلمس مفهوم ومحتوى الإستراتيجية في منظمات الأعمال، غير أن تلك المحاولات- على الرغم من ندرتها- كانت تتسم بغلبة الأطر النظرية والتعبير عن المفهوم، بالإستناد إلى حوارات فكرية وإرهاصات ذات علاقة بمفهوم ومحتوى الإستراتيجية.

&

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Publication Date
Mon Oct 22 2018
Journal Name
Journal Of Economics And Administrative Sciences
Leadership crisis and environmental pressures A Survey of the views of a sample of administrative leaders at Mosul University and the North technical University
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The administrative leadership relies on a variety of behavioral paths in the functional areas in which it operates, and thus indicates its ability and thus has the upper hand in the organizational events, and in such a way that it can draw lessons and evaluate the results so as to test the expectations within the framework of the changes.

Does the study sample leadership have the characteristics that enable it to contain both crises and environmental stresses?

The aim of the study was to determine the location of the administrative leaders in the system of the study sample from the issue of crises and environmental pressures. The study concluded with a number of conclusions, the m

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Publication Date
Wed Sep 01 2010
Journal Name
Journal Of Economics And Administrative Sciences
تحديد أثر مبادئ إدارة الجودة الشاملة في الأداء الإستراتيجي دراسة استطلاعية لآراء عينة من القيادات الجامعية
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The management of the overall quality (TQM)) of the philosophies that gained the attention of a large number of leaders and managers, practitioners and academics, as one of the prevailing management philosophies and desirable in the current period, is associated with the concept of quality itself, which shows the overall features and characteristics and attributes that related to the service and meet the needs of beneficiaries phenomenon and full, as was the concept of strategic performance with a significant level of interest from organizations because it is closely linked to the success of the organization in light of the changing competitive environment. These were the study in an attempt to see how a clear vision of the unive

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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
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
Thu Jan 25 2018
Journal Name
مجلة كلية الادارة والاقتصاد -الجامعة العراقية
أهميةتحسين ألاداءفي تخفيض تكاليف البحث والتطوير وزيادة رضا الزبون: بحثتطبيقي في وزارةالنقل– مرآبالكرخ الجنوبي للنقل الخاص
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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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