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%.
عد الرقابة الإشرافية احد اهم الأدوات التي تستخدمها البنوك المركزية في تقييم التزام المصارف بالمتطلبات التنظيمية والقوانين الصادرة منها وتستخدم البنوك المركزية عدة مؤشرات مالية منها مؤشر السيولة المصرفية لتقييم أداء المصارف تجاه حماية أموال المودعين وحماية المصارف من خطر نقص السيولة ومن ثم التعرض للإفلاس، لذا اقتضت الضرورة إلى دراسة مؤشر السيولة المصرفية الذي يستخدم كأحد أدوات الرقابة الإشرافية من قبل ال
... Show Moreملخص البحث: تعتبر مشكلة تعاطي المخدرات من المشكلات التي تؤثر في بناء المجتمع وأفراده لما يترتب عليها من آثار اجتماعية واقتصادية ونفسية سيئة تنسحب على الفرد و على المجتمع، كما أنها ظاهرة اجتماعية مرضية تدفع إليها عوامل عديدة؛ بعضها يتعلق بالفرد والبعض الآخر بالأسرة والثالث بالبناء الاجتماعي ككل. وتعد ظاهرة انتشار المخدرات من الظواهر الأكثر تعقيدا وبارزة هذه الظاهر ة وإحدى مشكلات العصر، الشاملة في المجتمع، و
... Show MoreThe Sufi poetry of Ibn Al-Faridh represents a true image of the spiritual experience, in which he presented the bright aspects of his experience, and his suffering in it, by formulating it in a poetic form, because the Sufi poetry is the result of an experience in which the Sufi seeks to achieve his goal of reaching the truth, and this is why Ibn Al-Faridh made his poetry a tool for expression on his own experience, the poet reflected his Sufi life in which he moved rhymes and weights.
The poet Ibn Al-Faridh stands as a witness to his making of Sufi poetry in the service of the purpose of who said, it is the embodiment of the Sufi journey in the stages, and the fluctuation in the places and si
... Show MoreThe study aimed to know the effect of the use alcoholic ethanol extraction of Boswellia Carterii In prolonging the period of preservation cooled ground meat in 4C for 6 days, it has been mixing ground meat with 150,300,450 mg/ml of alcoholic extract Consecutive, Where (0 was the control sample), All samples were stored separately for 0 , 3 , 6 days in Refrigerator temperature 4 C, Conducted by some microbial tests, Results have shown that mixing the ground meat with Boswellia Carterii extraction Led to prolong the storage of meat for 6 days at 4 C .and the Best result came when adding alcoholic ethanol extract of Boswellia Carterii by 450mg/ml Which Equal 0.9 g ,that reducing microbial load more higher than 150&300 mg/ml. All of thes
... Show MoreThe objective Effect of Internal and External Environment and its Psychological & Practical Reflection on the Political Decision-Making Process
The Current research aims to identify ( The effects of 4EX2 Model in Misconception of Chemical concepts and Higher Order Thinking for the Students of the Third grade average ) , To verify the objective of this research , the researchers added nul hypothesis following : There is no difference is statistically significant at the level of ( 0.05 ) between the average scores of students who studied 4EX2 Model and the average students who studied by using the Misconception of Chemical concepts and Higher Order Thinking test. The research was conducted on a sample of the average Third grade students in a Baghdad secretary for boys affiliated to the General Directorate for Educational in Baghdad Al – karkh 3 and for academic year ( 2015 – 2
... Show MoreThis study aims at defining the concept of the fragile state, a term that came into existence in 2014, when the states that had internal Problems and external interventions were referred to as the failure states. However, the indicators for their designation and the criteria adopted are 12 indicators that address all aspects of the State’s duties vis-a-vis its citizens. The study examined the reasons that led to the continuation of Iraq within the fragile states, and the selection of the five years within the time limits of the study due to the factors that led to the decline of Iraq and falling back within the most fragile countries. The study dealt with the fragile state challenges to the media reality as a result of the change of it
... Show MoreThe importance of the current study lies in the importance of the Tax policy that being considered one of the most important tools working on fulfilling the social, financial and economic goals and improving the investment environment in the country to become having the ability to activate the national economy. The current study has referred that ( Has the tax planning practiced by the Iraqi contribution companies led to increase the far-term tax outcome through getting benefit of the monetary funds and expansion in&nbs
... Show MoreDevelopment and progress of the fleet and the navy in Oman during
the reign of Sultan Said bin sultan from 1804 to 1856.
It had second level in Arab Gulf and Indian Ocean during the first half
of nineteenth century. The fleet of Oman in this time became after British
fleet.
Several reasons were behind the development of Omani fleet
- First : The aim of Sultan Said was to built a large navy yard in Arab Gulf
and Indian Ocean to encourage him -to made many ships factories.
- Second: Arab Gulf and Indian Ocean within the reign of Sultan Said
wittinsed the confilicts and wars between different forces it drived Sultan Said
to built agood and strong navy.
- Third The main aim of Oman during the reign of Sultan