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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
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 Jan 01 2024
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Effect of Adolescent Pregnancy on Dental Caries Experience and Selected Salivary Physicochemical Characteristics: تسوس الاسنان في حمل المراهقات
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Background:  Adolescent pregnancy is associated with major health consequences for adolescent pregnant women including medications and oral health problems such as dental caries and periodontal disease. Pregnancy is a unique state of physical, hormonal, and metabolic changes that can result in an oral cavity imbalance. Changes in salivary components and a decrease in salivary flow rate caused by an increase in progesterone may compromise saliva's protective effects, resulting in dental caries.

Objectives: To evaluate dental caries experience in adolescent pregnancy.

Method: A sample including 80 pregnant ladies were recruited in this study and categorized into a study grou

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Publication Date
Mon Jan 01 2018
Journal Name
وقائع المؤتمر الدولي 7 للغة العربية / دبي
تقويم اداء اساتذة اللغة العربية العامة في كلية الادارة والاقتصاد جامعة بغداد من وجهة نظر طلبتهم
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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
Wed Jun 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Person-Organization's Environment Fit and it's Reflection on the Work Outcomes
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This study aims to studying of Person and organization’s environment fit in a sample of Private bank’s reflection in its basic dimensions (Person-organization fit ,Person-Job fit, Person-group fit and Person- Person-fit )in the Work Outcomes (job satisfaction, the intention to leave the job, Job Engagement, and organizational  citizenship behavior ).

The questionnair’e has been used as a basic  instrument to gather data , As well as personal interviews with some of the staff of the research sample of private banks which were represented by (5) and included banks (Bank of Assyria for investment, the North Bank for Finance and Investment , Bank of the Tigris

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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 Dec 30 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
Sun Apr 01 2018
Journal Name
Journal Of The Faculty Of Medicine Baghdad
The incidence and risk factors of hypocalcaemia after thyroid surgery
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Background: Hypocalcaemia is a well-recognized complication of thyroid surgery. It is the most often transient event that occurs after extensive thyroid resection that may require calcium and/or vitamin D supplements to alleviate or prevent the symptoms.
Objective: of this study is to determine the incidence of hypocalcaemia after thyroid surgery and find out the risk factors involved regarding the patient age, gender, and muscular build, clinical diagnosis, the extent of surgery, ligation of the inferior thyroid artery, pathology report and the experience of the surgeon.
Patients and methods: This prospective study was carried out on 100 patients who underwent thyroid surgery for

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Publication Date
Wed Jun 01 2011
Journal Name
Journal Of Economics And Administrative Sciences
The relationship of empowering workers with organizational performanceField research of the views of the scientific leaders of a number of colleges at the University of Baghdad
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The Strategy of employees' empowerment, organizational performance and total quality management represent three informative which were and still the hub of many studies and researches including the current study. The higher education is considered one of the most important services sectors and the main development as well as the civil progress in the society. It is the main source that provides the organizations with the human resources having scientific or practical professions. So Higher Education has been chosen especially Baghdad University as a sample of the study. The study problem is concentrated to find answers of the following   questions: What the level of the powers mandate in the organization concerning the

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Publication Date
Sat Sep 01 2007
Journal Name
Journal Of Economics And Administrative Sciences
ادارة الطلب على المياه مدخل اساسي للتنمية المستدامة في الوطن العربي مع أشارة خاصة الى العراق
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المقدمة:

مع مطلع القرن الحادي والعشرين فأن الصراع على امدادات المياه الحيوية هو خطر قائم على الدوام في جميع مناطق العالم حيث يتجاوز الطلب على الماء بشكل كبير العرض القائم ولكون اغلب المصادر الرئيسة للمياه وخاصة في المنطقة العربية يشترك فيها بلدان أو أكثر ولان هذه الدول نادرا ما توافق على الاجراءات التفاوضية الخاصة بأقتسام الامداد المتاح من المياه مما يعني زيادة الخلافات على الوصول الى الم

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