Preferred Language
Articles
/
alkej-389
Transient Behavior Analysis for Solar Energy Storage in PCM-CFM Material Using Equivalent Heat Capacity Method as Storage Model
...Show More Authors

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%.

Crossref
View Publication Preview PDF
Quick Preview PDF
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
...Show More Authors

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

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Jun 01 2011
Journal Name
Journal Of Economics And Administrative Sciences
Diagnosis of the reality of marketing knowledge management"A survey of the views of a sample of telecom operatorsIn the city of Sulaymaniyah "
...Show More Authors

This research aimed to diagnose the perception based on Telecommunications of Iraq to the importance of activating knowledge management marketing in possession, as well as Indication of impediments to activate the management of marketing knowledge in the researched companies, also aimed to show the extent of the existence of significant differences in perception based on Telecommunications Iraqi importance of activating the management marketing knowledge in possession. To achieve the objectives of this research, the questionnaire was developed and distributed to a sample of telecommunications companies in the city of Sulaimaniya, was selected on the criterion according to the company's life in terms of seniority in the telecommunication

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Mar 01 2007
Journal Name
Journal Of Economics And Administrative Sciences
تأثير تدفق القروض الخارجية في تحقيق التحولات الهيكلية لاقتصادات بعض دول الاسكوا للمدة (1990 ـ 2002)
...Show More Authors

تتطلب عملية التنمية الاقتصـادية في الدول النامية مبالغ كبيرة من رؤوس الأمـوال اللازمة لتنفيذ البرامج والخطط الاقتصادية، ولما كانت الاسـتثمارات التي تنفذها هذه الدول خلال حقبة معينة، تزيد على ما تم  تحقيقه من موارد مالية محلية، فلابد أنْ يمول الفرق من خلال انسياب صافٍ لرأس المال الأجنبي (قروض ومساعدات) إلى الداخل خلال المدة نفسها، لغـرض سَدّ الفجوة في المـوارد المحلية المعدة للاسـتثمار، وعانت بعض د

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sun Dec 20 2020
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
تقييم مخاطر نشاط مبيعات الشركة العامة للصناعات الجلدية في ظّل ظروف السوق المحلية للمدة 2010 - 2014
...Show More Authors

Research is aimed at defining the risks that the sales activity of the General Company for Leather Industries about a special, then diagnose these risks, through a set of indicators, which indicate its existence and try to overcome them, and minimizing the negative effects on those activities.

The research found some conclusions, which emphasizes that the General Company for Leather Industries, suffer from a lack of profit, and a large decrease in sales; a result of absence of demand on its products and rising cost of the expenses to income ratio of, which was reflected in the cost per unit produced. Also the conclusions shown that the number of sales outlets for the company to cover the geographical area is not enough, in spite

... Show More
View Publication Preview PDF
Publication Date
Mon Apr 03 2023
Journal Name
Journal Of Educational And Psychological Researches
The Effect of Proposed Strategy According to the Realistic Mathematics Theory on the Achievement and Mathematical Interrelation of third Intermediate Students
...Show More Authors

Abstract

The current research aims to identify the effect of the proposed strategy in accordance with realistic mathematics on the achievement and mathematical Interrelation of third Intermediate students. Two samples were tested from the middle third grade in a school affiliated with the General Directorate of Baghdad- Rusafa, the first for the academic year (2022-2021). The experimental group is (30) students taught according to the proposed strategy, and the control group is (30) students based on the traditional method. To achieve the research objective, the researchers developed a test for achievement consisting of (30) items and a test of sports interconnection composed of (20) items. The results of the stu

... Show More
View Publication Preview PDF
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
...Show More Authors

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

... Show More
View Publication Preview PDF
Crossref
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"
...Show More Authors

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

... Show More
View Publication Preview PDF
Crossref
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
...Show More Authors

View Publication
Publication Date
Thu Dec 30 2021
Journal Name
مجلة العلوم القانونية
جزاء الاخلال بالوعد بالتعاقد في ضوء تعديل القانون المدني الفرنسي بموجب المرسوم رقم 131 لسنة 2016
...Show More Authors

يتناول البحث جزاء الاخلال بالوعد بالتعاقد في ضوء تعديل القانون المدني الفرنسي بموجب المرسوم رقم 131 لسنة 2016

Publication Date
Fri Mar 01 2024
Journal Name
Journal Of Physical Education
المرونة التنظيمية لدى اللجنة الأولمبية الوطنية العراقية من وجهة نظر أعضاء الهيئات الإدارية في الاتحادات الرياضية
...Show More Authors