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%.
That grammatical studies, a phenomenon of the Arabic language,
enabling the researcher during his research of the development of sentences,
textual analysis, to be the result of that meaning semantic of a sentence, and
the statement of the function the individual, in terms of its meaning in
context, and a link to the meaning lexical give indications of the current
single, and correlation analysis II , in terms of significance with the current
status syntactic to that individual, and these of the most important features of
grammatical studies of modern, based on the relationship structure sense, and
the relationship of the meaning of the structure, we looked for Aiklo for such
a study, Koran, all meanings and co
The shortcomings of the Muslim regime were however, became more obvious in later periods. Under the first Abbasids, the Muslims bourgeoisies were still a new class, rising in the social hierarchy of the caliph empire. It became even powerful class and a factor to reckon with
بات الفساد ظاهرة عالمية تهدد المجتمعات وبقائها ، وبدت الانقسامات المجتمعية تتضاعف في البلدان التي ينتشر فيها الفساد بمختلف أنواعه وتسمياته ، حيث استكشفت الدراسة بأن التشريعات الجنائية حرصت على تقرير نظام عقابي خاص لمواجهة جرائم الفساد مما استوجب بنا بيان المظاهر القانونية للفساد السياسي المتمثل بالرشوة الدولية والرشوة الانتخابية لان الفساد لم يعد متعلقا بالجانب الاقتصادي فحسب بل امتد إلى الجوانب الأخرى
... Show MoreThe main target of this research is to follow the stages of the emergence of
the idea of republican form of government from its very beginning , yet there
were many elements from different estates thinker , educated , few of heads of
clans . This first opportunity for the mobilization of politically-minded people
with fundamental activity like najei shokat . hussain al-rahal notable poet maruf
al-rasafi those who formed what so called the political elite who believed in
constitutional , democratic parliamentary republic , one of them was al-rahal who
called for a constitutional republic even before the emergence of the
constitutional movement in Iran and ottoman empire (1908).
The holy najaf become cultural cen
Годы, принадлежащие концу XIX – началу XX столетия, вошли в русскую литературу под красивым названием Серебряный век. В это время в стране появился целый ряд выдающихся поэтов, имена которых навсегда останутся в русской и мировой литературе. Это Ахматова, Гумилев, Блок, Маяковский и многие другие. Все эти люди творили в нелегкое для России время. Началом Серебряного века условно считают 189
... Show MoreThe research aim to measure the impact of the Industry specialization of the auditors on the quality in audit in Iraqi auditing firms, as well as measuring the factors of Industry specialization in the Iraqi audit companies by measuring the market shares of Iraqi audit firms that audit the companies listed on the Iraqi Stock Exchange For 2010 to 2016, by surveying the opinions of (35) Audit firm on the impact of the Industry specialization of auditing firms in audit quality factors, The effect of the variables was revealed through the use of the survey form Distributed to Iraqi audit companies, The industry speci
... Show MoreAcademic Buoyancy of High School students at the Distinguished Schools