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%.
The stage of the establishment of the Alawite state in tabaristan was one of the most important stages in the history of the Shiite sect in Iran
Abstract: The researcher aims to highlight the historical frames of political development in royal regime era (1921-1949) and study its transitions on social-political aspect for the various periods during this consistent era of Iraq history. As some elements played an important role in shaping this era’s features ,as well as 2hat succeed it, which mainly affected the political progression’s configuration, such as : political culture role, social and cultural foundation, state policy essence and the unofficial institutions remarkable role in influencing public awareness and concerning it's relation to the state ,the clan and religious institutions. The researcher employed Alexis de Tocqueville’s evaluation criteria and indi
... Show MorePrince Kikaus explained to us Conditions of writing and establishing .Then he touched upon the Conditions of the ministry and qualities that must be characterized Author and minister both need machines must be availabla in person if given these positions .he was creative in presenting his ideas which is not without judgment an knowledge.He had a distinct style in mentioned professions and administrative hierarchy As explained in his speech About the writer and his Correspondence and construction and writer position who has developed into a minister then he touched it to the cabinet system and what the minister should do.of qualities .and the importance of the post of minister who mentioned several points to him ou
... Show Moreتعد الصهيونية المسيحية الداعم الابرز للسيادة الصهيونية اليهودية على القدس، ويستند هذا الموقف الذي تتخذه الصهيونية المسيحية الى مجموعة من المعتقدات التي يشكل الاعتقاد بالعودة الثانية للمسيح وتأسيسه لمملكة سعيدة تدوم لالف عام محورها، ليصبح الاهتمام بمستقبل الشعب اليهودي احد الاركان الاساسية لمعتقدات الاصوليون المسيحيون لاسيما الصهيونية المسحية، فالتفسير الحرفي للكتاب المقدس قادهم الى اعتقاد مفاده: ان عو
... Show Moreيهدف البحث الحالي الى استكشاف علاقات التفاعل والتاثير بين الاحتكام للمكانة والتوجه للفردية– الجماعية والدمج التنظيمي مستنداً على مزج اختلاف القيم الشخصية مع افكار نظرية الهوية الاجتماعية لبلورة نموذج البحث. وفي ضوء هذا تم صياغة عدد من الفرضيات التي توضح علاقات التفاعل ما بين ابعاد الاحتكام للمكانة والتوجه للفردية– الجماعية للتنبؤ بوجود الدمج التنظيمي. جمعت البيانات باستخدام استمارة الاستبيان ووزع
... Show MoreUnder major developments in the field of business environment, the use of traditional budgets do not fit into these developments and adversely affect the future performance of the enterprises, which requires the transition to modern systems in the preparation of the budgets of activity based budgeting ABB because they provide a more accurate and objective estimates based on scientific foundations and practical avoided arising from the use of traditional budgeting problems, Where ABB is working better allocation of resources based on the activities of an enterprise and this positively affects the performance of the administration for the purpose of evaluating their performance according to responsibility centers and decision-making govern
... Show MoreThe subject of population support is one of the most important topics in the geography of the population as it shows the amount of burden on the workforce in society and reflects the balance or
The research aims to shed light on the importance of forensic accounting and its impact on the outcome of the activity of the Iraqi general insurance company by winning the lawsuits filed against the company because the forensic accountant (the judicial expert) possesses the ability to interpret and analyze the data. The research community represents the insurance companies in Iraq. Iraqi insurance, and the researchers adopted the descriptive approach in covering the theoretical aspect and the deductive approach in covering the practical side, depending on the financial statements of the Iraqi insurance company for the years of research.
One of the most important conclusions reached by the researchers was that forensic accounting
... Show More