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 effect of 5555 strategy on reading comprehension among 4th preparatory students Assist. Prof. Dr. Hassan Khilbas Hammadi College of Education Ibn Rushd – The University of Baghdad Assistant Lecturer. Waleed Khaled Talib Directorate – General For Education Province Of AL - Anbar The purpose of study is to identify the effect of 5555 strategy on reading comprehension among 4th preparatory students. To do this, null hypothesis was postulated. The author hypothesize that there is no a statistically significant difference at (0.05) level between experimental group's scores who study reading comprehension subject following the 5555 strategy and control group's scores who study the same subject following the traditional method in readin
... Show Moreاصبح لمجالس الادارة في الشركات دوراً حاسماً في تعزيز الحوكمة الفاعلة، كونها تتحمل المسؤولية النهائية عن نظم الرقابة الداخلية في شركاتها، ويلعب التدقيق الداخلي دوراً اساسياً في مساعدة تلك المجالس على القيام بمهمات الحوكمة. ولهذا يبذل مجمع المدققين الداخليين الامريكي جهداً كبيراً في توجيه اعضاءه ليكونوا متخصصين في اصول حوكمة الشركات وتحسين وتقوية اخلاقيات العمل وسلامة المنظمة.
لذا فإن ا
... Show MoreThe process of doing many kinds of industries , crafts , professions around Islamic Arabian State , they enable us to say that Arab Muslims over their homelands had been occupied various types of crafts and manufacturing before emergence Islam . Moreover Islam encouraged to work within manufacture field . And These matters were clarified through verses of the Holy Qur’an and honored prophetic guidance ( Sunna ) . Whereas Arab Muslims applied principle “ Free of Business “ . They admitted to different social groups such as pact – fellows people to profession or craft which they desire to work . We have to not forget that Arab Muslims had broken all restraints and shackles which had restricted the worker bef
... Show Moreمشكلة البحث
ان التصميم هو توالد افكار عدت اساس له حيث انها اشياء لها معنى لامور اقتضت الايعاز باعداد هذه التصاميم، اما المصمم فهو الشخص الملم بمباديء واسس التصميم من اجل تنفيذ هذه الافكار بطرق علمية مدروسة، الا ان هناك سؤالا يطرح هل بالامكان لاي شخص ان يرسم فكرة تصميمية؟
الجواب هو نعم فالتصميم ليس مقتصرا على المصمم فحسب بل ان باستطاعة أي شخص ان يعبر عن ما بداخله من افكار سواء ك
... Show Moreيعد النظام التعليمي لاي بلد انعكاسا للمستوى الثقافي والحضاري للمجتمع وعادة ما يحدد هذا النظام ويوجه من قبل التنظيمات السياسية والاقتصادية والاجتماعية في المجتمع كونها تعتمد علية في تحقيق اهدافها ,وصبحت الجامعة اليوم تمثل عمد النظام التربوي والتعليمي بما تمتلكه من كفاءات وقد ا رت وامكانيات بشرية ومادية تستطيع من خلالها رفد المجتمع بما يحتاجة من قد ا رت بشرية متعلمة في كافة الاختصاصات ومناحي الحياة لادامة ال
... Show MoreIbn Hajar is one of historian who had a role in historical writing represented by his writings in those active participation in the Arab-Islamic civilization, particularly his approach to intellectual, and pictures of us in his book that's part of the intellectual heritage, but a line that was a key part of the book, any manuscript
Companies compete greatly with each other today, so they need to focus on innovation to develop their products and make them competitive. Lean product development is the ideal way to develop product, foster innovation, maximize value, and reduce time. Set-Based Concurrent Engineering (SBCE) is an approved lean product improvement mechanism that builds on the creation of a number of alternative designs at the subsystem level. These designs are simultaneously improved and tested, and the weaker choices are removed gradually until the optimum solution is reached finally. SBCE implementations have been extensively performed in the automotive industry and there are a few case studies in the aerospace industry. This research describe the use o
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While practicing of International business particularly that centered on foreign direct investment, let on one side, to achieving objectives of transnational corporations specially that represented in continuous pursue to improving its cash flows and maximization of stockholders wealth which is considered the most important objective to the transnational corporations, but in the same time its lead, on other side, to increasing the foreign exchange risk exposuring these corporations. So, the transnational corporations (TNCs) struggling to make strategies which are dealing in smart way, with this risk and its management in way that enable to avoiding risk comple
... Show MoreEl color es uno de los elementos novelísticos que ayudan los autores para desarrollar las acciones y llevarlas al desenlace adecuado. Y Blasco Ibáñez depende al color para pintar las escenas artísticas dentro sus novelas, especialmente, sus novelas que pertenecen al siglo de naturaleza. Él conocido con la abundancia de los colores para describir el ambiente y los personajes, como indica el autor catedrático José A. Balseiro:
"su pluma no supo__ como el pincel de los primitivos__ del matiz logrado a toques mínimos, pacientes. ¿No era, a caso, coterráneo de Joaquín Sorolla, en cuya paleta mediterránea celebrábase, día tras día, el milagro del f
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