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%.
In the past, an absolute authority was held by the father and his decisions were imposed
and obeyed strictly without discussion. Later, many economical changes took place and
affected all of the family members dramatically creating a whole new concept of authority
in the family, a one that is based upon sound leadership, mutual understanding and
consultation among family members.
Women carried responsibility of doing all domestic jobs and served family members,
however, when she went to work outside her house, these loads began disturbing and
exhausting her. Therefore, man started to participate in assisting his wife. In addition,
industrial advances contributed in making these jobs easier than before.
This has
Thank Allah and prayers on the Prophet Mohammed the man of truth and honest (PBUH).
The initiations in the role of Imam Ali (PBUH) is considered among the important initiations in Islamic thinking .It is considered the way to invest the conditions that the individual in the light of it can reach to make gains and achievements
Traditionally, style is defined as the expressive, emotive or aesthetic emphasis added linguistically to the discourse with its meaning is the same. In the current study, however, style is defined as the linguistic choice that the language users can make for specific purposes.
This study, thus, aims at analyzing political Arabic and English speeches to find out whether there are differences of style between English and Arabic and whether the choices the language users make can show any traits of their psychological status.
To fulfill the above aims, the study hypothesizes that English and Arabic speeches can be analyzed stylistically and that there are stylistic difference
... Show MoreThe wisdom of the Creator ensures the call of every prophet with a miracle that would be something beyond what is familiar from the customs
The research dealt with the effect of the tax examiner's efficiency in detecting tax evasion, as the research problem dealt with tax evasion, especially in Iraq, for many reasons and factors, including those related to tax administration represented in administrative corruption and the complexity of procedures in the tax accounting process and failure to achieve justice in the tax treatment, including the taxpayer himself, as he tries to evade for reasons Related to the level of tax awareness, loss of confidence in the tax administration, and reasons related to the state's inability to manage the services file well and its ability to achieve the set goals, This reflected negatively on the emergence of some of the consequences of
... Show MoreThe message of the Kurdish tag tagged with(Mada alfay fi taqrir lays kamithlih shay) one of his most prominent scientific messages in the door of faith, especially in the matter of the unification of the divine self and its distancing from all analogies and representations and the importance of this message historically, due to its documentation of a stage in the development of Islamic speech thought, where the logical method was taken over the minds of the intellectuals of Islam, including the kurani, whether it is in understanding the quranic and modern meaning or as a way of convincing me towards the opponent.
The Kurd was able to use logical concepts to marginalize the difference between grammarians and interprete
... Show Moreالغلط في القانون الانجليزي على انواع ثلاثة (غلط مشترك Common mistake ) يقع فيه الطرفان مع علم كل منهما بنية الآخر ويقبلها دون ان يشوب الاتفاق نقص او يعتريه تحفظ ، و(غلط من الجانبين Mutual mistake) يكون كل متعاقد واقعا في غلط فيما يتعلق بما قصده الآخر، فيقدم كل منهما عرضاً مخالفاً للآخر و(غلط من جانب واحدUnliteral mistake ) يقع فيه احد المتعاقدين فقط ويكون المتعاقد الآخر اما عالماً بالغلط او يفترض انه عالم به . فإذا دفع احد المتعاقدين
... Show MoreScams remain among top cybercrime incidents happening around the world. Individuals with high susceptibility to persuasion are considered as risk-takers and prone to be scam victims. Unfortunately, limited number of research is done to investigate the relationship between appeal techniques and individuals' personality thus hindering a proper and effective campaigns that could help to raise awareness against scam. In this study, the impact of fear and rational appeal were examined as well as to identify suitable approach for individuals with high susceptibility to persuasion. To evaluate the approach, pretest and posttest surveys with 3 separate controlled laboratory experiments were conducted. This study found that rational appeal treatm
... Show MoreIF we called twentieth century, the century of productivity and information revolution, the suitable address for twenty-first century is (( The quality century )) .
The research aims to initiate Arabic prize for quality to apply concepts and strategies of total quality management at Higher education sector, which is a vital sector and it may be the most importance sector because it provide efficient human manpower working at all other sectors.
The suggested prize take in consideration the specialty of this sector, and when we apply perspectives of this prize this will promote Arabic universities performance as well as the quality of graduates.
The importance of this research due to the necessity of this pri
... Show Moreيعد 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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