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%.
Of good reasoning (the art of unique moral turn him poets of Andalusia in
poetry verse emitter myself, and to achieve a very technical. Either the emitter is
related to the nature of the environment and the composition of personal Andalusia
of appetite for life and interaction with the legibility beautiful, and it was (wit)
feature in them even said they are charming as Bagdad ions , and either art, it made
them this color to show their ability intellectual in the search for bugs, and
stimulate their imaginations in a contract equations in the interpretation and find
justifications for the ideas and meanings Exaggeratedly times, and especially in the
purpose of praise, and novelty in many cases, as in the spinning
Bekanntlich hat jede Sprache ihre eigenen charakteristischen Besonderheiten. Davon ausgehend gibt es auch gewisse Unterschiede zwischen dem Arabischen und dem Deutschen. Zu den wichtigsten Gebieten der deutschen Grammatik gehören die zusammengesetzten Sätze, vor allem Satzgefüge mit den über- und untergeordneten Sätzen. Dazu gehören auch die Äquivalente der Nebensätze, besonders die Infinitiv- und Partizipialkonstruktionen.
Die vorliegende Recherche hat eine der grammatischen Strukturen des Arabischen und des Deutschen nämlich die dass-Sätze und Infintivsätze mit zu und deren Wiedergabemöglichkeiten in den beiden Sprachen zum Inhalt, weil die Infinitivsätze mit zu den Deutschlernenden beson
... Show MoreFood comes after air and water in terms of importance in the survival of human beings, In addition, it is the support and strength of health and support, if lost or destroyed man would die or get sick and become a heavy burden on himself and his society. Food, like other sources of life, is subject to various risks and corruption comes from countless sources. Among these dangers is the result of spontaneousness, lack of knowledge or compulsion due to the interaction of variables beyond the will of the producer and the consumer, such as pollution of water, air and environment and their reflection on food consumed by people. However, we can’t deny that some reasons of corruption are intentional and resulting from a planning in advance in
... Show MoreAssyrian merchants established in the second millennium BC Assyrian commercial settlements in Anatolia, and these settlements had a great cultural value
البنية الاقتصادية الاجتماعية للادارة الجديدة في الولايات المتحدة الامريكية
The research in Islamic history is considered a title for the glory of the nation and a mirror for the intellectual and mental maturity of the men of the Islamic state who played an important role in saving humanity from darkness to light and from ignorance to knowledge and to show their position in building the Islamic state, and to highlight the importance of their conquests of neighboring cities and the expansion of Islam, and for this reason they appear The importance of writing on the topic (The Battle of Dumat al-Jandal and its impact on the era of the Prophethood and the Rightly Guided Caliphate). The reason for choosing this topic was to show the status of Dumat al-Jandal and its importance in the Islamic state and its great role
... Show MoreViolence can be identified as an outreaching on others’ dignity,
freedom, properties, and life. Therefore, violent actions cannot be determined
only on materialistic attacks such as killing, beating, robbery, rape, and civil
wars, but it also includes the verbal attacks such as insult, threat, and cursing.
Violence against women can be identified as any bad actions that are
done against women, which lead to a physical or psychological harm, and
invade their safety and freedom whether these actions come from men or
women, against one woman or a group of women in special and general
places.
Before, the social, historical and lawful manners concentrated on
sexual distinction between the men and a woman, which
اهتمام العلماء العرب بالحروف مبينين معانيه موضحين مقاصده
شَهِدَت منطقة الخليج العربي والسَّاحِل العُماني تصاعد مُستوى الحِراك الشعبي، والمُطالبات بتحقيق الاِستقلال التام، وإنهاء الاِلتِزامات والاِرتِباطات الدولـيَّة سواء كانت في إطار الحِماية أو الاِستِشارة أو الصِّداقة، وأصبحت واجِهات ملحوظة من قِبل الفِئات المُـثـقَّـفة في بدايات العقد الثاني من القرن العشرين، وعبَّرت فيها القِوى الوطنيَّة عن حاجاتها في إجراء عملـيَّات التغيير والتحوّل الاِجتِماعي وعلى
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