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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 Jun 01 2022
Journal Name
Journal Of College Of Physical Education
تأثير تمارين الهايبوكسيك على جهاز التجديف الارضي (الاركوميتر) في تحمل السرعة والمستوى الرقمي لفعالية 200متر تجديف كاياك للاعبي المنتخب الوطني للشباب
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Publication Date
Tue Oct 01 2013
Journal Name
Journal Of Economics And Administrative Sciences
Efficiency of Human Resources Information System and Its Impact on The Level Effectiveness of Employees Performance Appraisal System / Practical Research on Ministry of Higher Education and Scientific Research
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Abstract

The research aims to determine the role of the efficiency of Human Resources Information System in the effectiveness of Employees Performance Appraisal System in the Ministry of Higher Education and Scientific Research / Center for the ministry, it was touching the researchers need the ministry to devise methods that employ outputs Human Resources Information System in the organization surveyed for the development of methods and levels of process evaluate the performance of its employees, in order to identify the extent of the role played by human resources information system in the process of assessing the performance of employees, we raised the question of the President as follows:

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Publication Date
Sun Jan 01 2017
Journal Name
مجلة كلية الادارة والاقتصادللدراسات الاقتصادية والادارية والمالية
تصميم الترتيب الداخلي األمثل باستعمال تقنية التخصيص النسبي المحوسب للتسهيالت )CRAFT)بحث تطبيقي في الشركة العامة لصناعة الزيوت النباتية – مصنع المأمون
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The facilities layout are among the most important of the most influential factors in the efficiency of the production system, and represents the systematic layout of the various work centers, tools, persons, and other auxiliary services within the factory. Careful selection of the technique that would be used in Re-layout, represents an important step in reaching to the optimum layout that keeps on reducing handling costs and reduce unnecessary movement of materials, as well as the regularity and functioning of the flow of materials through the facilities. The research aims to propose a new layout of (Al-M'ammon Factory / The General Company for Vegetable Oils Industry), and then re-layout according to the new propose layout by using of te

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Publication Date
Thu Dec 01 2011
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
تقويم قانون الخدمة الجامعية رقم 23 لسنة 2008 وأثره في تقليل مظاهر الفساد الإداري والمالي: دراسة تحليلية قدية لنصوص القانون وتطبيقاته
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This research includes an analytical and critique study for the version of the University Service Law No.23 for the year 2008, containing all its aspects and failure whether in its legislation or its applications.

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Publication Date
Mon Jun 01 2020
Journal Name
Journal Of The College Of Languages (jcl)
The Labyrinths of the Contemporary French Novel Through the Texts of Patrick Modiano: Les Labyrinthes du Roman Français Contemporain à travers l’Œuvre de Patrick Modiano
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The current paper aims to study the different forms by which the theme of labyrinth imposes itself as a preferred narrative structure in the novels of the French writer Patrick Modiano. Theoretically speaking, the current research paper will limit itself to the theoretical framework of the textual poetics which relies on the study of literary texts without paying much attention, neither to the context, nor to the life of its author. The analysis of the strong and varied links that Modiano's novels establish with labyrinth represents a field which has not received adequate attention by the critical studies dedicated to this French writer. As it will be shown throughout the current paper, Modiano views labyrint

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Publication Date
Mon Dec 23 2024
Journal Name
Tikrit Journal Of Administrative And Economic sciences
Determination of competency levels and auditor evaluation procedures to the international standard (ISO19011: 2018) A case study at the Ministry of Construction, Housing and General Municipalities/Audit Directorate
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The current research seeks to achieve several objectives, including knowing the extent of the audit directorate of the Ministry of Construction, Housing and General Municipalities of the International Standard (ISO19011:2018) regarding determining the efficiency and evaluation of auditors and diagnosing the gap between requirements and application and knowing the reasons for not applying some of the items in the standard, starting from the problem, The field raised the following question (Does the audit directorate determine the efficiency and evaluation of auditors according to the standard ISO19011:2018?), and the importance of research lies in determining the return that can be achieved by the directorate through its application of stand

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Publication Date
Sun May 06 2007
Journal Name
كلية التربية البدنية وعلوم الرياضة/جامعة بغداد .
تأثير التمرينات الاوكسجينية واللاأوكسجينية في الوحدة التدريبية لتطوير بعض القدرات الوظيفية والبدنية للاعبي كر ة القدم بعمر (13-14)سنة. رسالة ماجستير
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Publication Date
Mon Feb 07 2022
Journal Name
مجلة الدراسات الاقتصادية والادارية
Measuring readiness to accomplish organizational change through personal characteristics: Crisis management approach: An exploratory study of the opinions of a sample of managers at Central Technical
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The self-evident truth existing in today's business environment is the continuity of change and its continuity and turmoil, also its increase over time as it is more abundant, abundant, wide and complex than ever before, and it is the dominant feature in the business environment, as different organizations and operating units can find themselves shifting from the top to the bottom. And then it requires its departments to strive to adapt to these rapid and turbulent shifts and changes by bringing about a series of organizational and adaptive changes that are not limited to one organizational aspect only but rather include all organizational components. Accordingly, this research came to determine the readiness of public organizations to chan

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Publication Date
Sun Apr 02 2017
Journal Name
Journal Of Educational And Psychological Researches
معوقات تطبيق الإدارة الإلكترونية في وزارة التربية والتعليم بسلطنة عمان(البوابة التعليمية الإلكترونية أنموذجاً) من وجهة نظر موظفي المديرية العامة لتقنية المعلومات
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Drawbacks of Implementing Electronic Management in the Ministry of Education (A sample: Oman Educational Portal) from the Point of View of IT Staff. The study aimed at discovering the drawbacks of implementing electronic management in the Ministry of Education (a sample: Oman Educational Portal) from the point of view of IT staff, and that is by answering the following questions: - What are the main drawbacks (administrative, financial, technical and drawbacks related to human resources) that hinder implementing the electronic management in the Ministry of Education (a sample: Oman Educational Portal) from the point of view of IT staff? - Are there any statistical significance differences at the level (0.05) between study samples on the

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Publication Date
Sun Mar 26 2023
Journal Name
Arab Science Heritage Journal
الاديب الكاتب والمؤرخ الفقيه يحيى بن خلدون (ت 780هـ/ 1379م) كاتب ديوان الانشاء في دولة بني زيان (633-962هـ/ 1235-1554م) بتلمسان
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    A prominent figure such as Yahya bin Khaldoun and a scholar of the moroccan countries in the medieval era, and had a special place in the history of the country and the state of Bani Zayan, and the positions he occupied in it and left his scientific, literary and historical traces, leaving him an imprint in the course of history and its events, and in this study
I dealt with the research: his personal life : his name and lineage, then his upbringing and his family.

    The aim of the study is to know this character in the details of his personal and scientific life, according to the historical descriptive research method, including description and presentation of events, and linking them in a

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