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%.
Highlights the role of taxes in being a major source of funding sources internal economic and social development, and then, any decrease in tax revenue caused by tax evasion, for example, would weaken the government's ability to finance their investments and core financing private sector investment as a result of reduced ability to increase their reserves's cash banks, as well as the weakening of the effectiveness of tax evasion taxes as a tool to guide economic activity in the framework of service for development, and to achieve justice. And the statement of the reasons for and methods of evasion mandated to pay the tax due on them, whether legitimately or illegal with the statement of the proposed methods to tackle tax evasion and elim
... Show More: The objective of this research is to demonstrate the possibility of applying the principles of corporate governance in the General Authority for taxes, as the goal to identify the basic requirements for the application of the principles of corporate governance in the GCT with an indication of the role of governance in improving the strategic performance of tax administration. The research was based in part applied to the analysis of the results form questionnaire designed to achieve the goal of the research .
لقد أثارت فكرة القانون الطبيعي اهتمام الفقهاء والفلاسفة في الشرق والغرب ، القدامى منهم والمحدثون وشيدوا نظريات وأقاموا مناقشات حول فكرة القانون الطبيعي والطبيعة والعقل الطبيعي مما جعل هذه الفكرة تبدو إحدى المعطيات الأساسية للفكر الإنساني والتي لا يمكن تجاوزها في إي وقت أو في إي مكان. يبدو إن مفهوم القانون الطبيعي وان كان يعد من اعرق المفاهيم الفلسفية إلا انه يعد واحد من تلك المفاهيم التي وان احتفظت بجوهرها
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Praise be to Allah، and prayers and peace be upon His Messenger and His chosen one، his family، companions and his family and his family.
After that، this is a study on the question of the claim، as one of the controversial questions that are the mainstay of debates، and I looked at it: the limit of the question of the claim، its importance، its impact، its aspects of corruption، its sections، and the representation of its sections of the fundamentalist controversy;
The research was according to the following plan:
Introduction، in which she mentioned: the importance of the research topic and the reason for its selection، its questions، its l
... Show MoreSomal is considered one of the unstable and restless African Arabian country in
comparison with other Arabian. It has been exposed to division and separation by
European colonization process that worked hardly on dividing this country according to
Berlin conference (1884-1885). Even after obtaining its independence during the sixties
and being led by civilian organizations which were unable to solve the problems of
Somalian society after obtaining the independence.
Somal continued its suffering even after the military rule under the leadership of
Mohammed Sayad Beree.
During Beree's rule, Somal suffered from the War with Ethiopia, as well as it
witnessed an economical Crisis. It suffered also from the tribal po
يركز البحث على قصائد ماكسيمس للشاعر جارلس اولسن.تعتبر هذه القصائد ابداع غير تقليدي ونادر حيث استطاع الشاعر من خلالها ان ياخذ القارىء في عمليه مستمرة لشخصية واحدة في مكان واحد وهو جلوسستر.ان قصائد ماكسيمس مقسمة الى ثلاث مجلدات تقرأ كقصيدة واحدة . تقرأ هذه السلسلة من القصائد بسياق شخصي وسياسي ووجداني. تركز الدراسة على فكرة الوقت والمكان حيث تظهر القصائد بانوراما من المناظر الطبيعية والاشخاص والنماذج بصوره مس
... Show MoreThis study took place during the first semester 2006-2007 at the same time the Jordanian universities were getting ready to receive the American team sent by QAA to check out the defects in the educational system of these universities, the researchers concentrated on the practical study more the than the theoretical study, the theoretical study covered the understanding of quality & quality in education as well as the authorities responsible for the regulations & quality standards such as QAA ,JMOHE, Al-Hussein Fund For Excellence. The main problem which faced the Jordanian private universities was the conflict in objectives between profitability & qualitative output which was because of lack of long tem strategic plann
... Show Moreان تقدير مسؤولية المحاسب في تصميم نظام المعلومات المحاسبي من منظور تاريخي سبقت استخدام الحاسوب كأداة معلوماتية للاعمال، لما له من رؤيا بالتطورات الرئيسية لنظام المعلومات والتي اهمها تحديد متطلبات مستخدمي المعلومات وتعيين مضمون وشكل مخرجات النظام من التقارير وتحديد مصادر البيانات وانتقاء القواعد المحاسبية الملائمة فضلاً عن الرقابة الضرورية لتكامل وفاعلية النظام.
ان النظم المحاسبية التقليدية غالبا
... Show MoreThis research aims to understand the main problems and family
commitments faced by working women, and make proposals that would stop or
lessen them, the researcher made questionnaire , applied on a sample of (20)
university female teachers, the study showed that the main problems in respect to
their importance as: Anxiety of leaving children at home alone, the weak role of the
nurseries and kindergartens in taking care of the children, relative large number of
children per family which would lead to more commitments, and the unavailability
of convenient working arrangement for working mothers.