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%.
يعد التحليل العاملي Factor Analysis أحد الأساليب الإحصائية المهمة والتي يصعب تنفيذها يدويا ً أو بالألات الحاسبة الصغيرة لذا لاقى الباحثين صعوبة في إستخدامه في البداية بل كان من المستحيل القيام به ، لذا فالمؤلف قد تناول التحيلي العاملي الاستكشافي لكونه إسلوب إحصائي يستخدم في تحليل البيانات ويتطلب شروطا ً لأستخدامه ودقة في مراعاة هذه الشروط ويتطلب أيضا ً معايير يجب أن يتأكد الباحث من توافرها في البيانات وهذا ما تم ت
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made tackles concerning with this phenomena.
This article has been researched about an impacts of it to the nature of structural
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The international field has witnessed economical and technological developments which made the world one market . this increased the competence among the international dealers . the market, thus comprises states, governments, international organizations, and giant economic blocs which all seek to unify the behavior of the game by dealing and seizing the opportunities and facing the threats which concern deregulation in all its forms .This led to a number of developments including the increasing number of mergers and posts which are considered investment alternatives. &nb
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... Show MoreThis search in the virtues of the daughter of the Prophet Muhammad, to read on their boards want to recount loving and faithful), as stated in the introduction to the author, Abdullah Bin Ibrahim Al-Mirghani (D. 1207 H.) to give reasons in writing the manuscript, which was of an introduction and three chapters and a conclusion was the first in the door thanks to the great lady and on her birthday and her marriage and her death and subsequent events and the third in her them prayers and then the finale which was in love with the Prophet and calling for God to pardon and forgiveness and a good end. I was interested in this manuscript by Mirghani, Hadith and all accounts in reference to the virtues of the great lady to examine a manuscript
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