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%.
Chapter One
First, the importance of research and the need for him
Highlight the status of the nation and occupies a decent position among nations by what they offer for the good of humanity and tender, which is based mainly on the human and material wealth owned by the nation.
The investment of this wealth investment scientifically accurate based on the strong foundation that qualifies them to heights of glory, so stand out necessary development of all energies Alepeshriaaly the limit can not be considered as these energies fortune unless all elements of effective elements characterized by the positive interaction in various spheres of life and in the in
... Show MoreThe political system during the reign of Imam Ali (peace be upon him) was based on explicit openness in its features and objectives away from misinformation, and built its foundations and foundations on the Koranic legislation, and enacted by the Prophet (peace be upon him), and the decent legislation required by humanity
The research aims to study some of the human characteristics of the state of Singapore to know the impact of these characteristics on the strength of the state, its development and. The research included two aspects, theoretical and analytical, using the descriptive analytical method, force analysis method, as well as the historical method. The data was analyzed according to mathematical equations, including the size of the country's population, the extraction of the population growth rate and the concept of age structure, where some indicators related to this concept have been explained. The researcher reached a set of results, the most important of which were: that the population size of the state of Singapore in the period between (19
... Show Moreان حماية البيئة وتخفيض التكاليف من األهداف التي تسعى الوحدات االقتصادية الى تحقيقها لكي تتماشى مع التوجه العالمي لحماية الموارد الطبيعية وإنتاج منتجات صديقة للبيئة وفي الوقت نفسه التخلص من االلتزامات التي تتحملها الوحدات االقتصادية من تكاليف بيئية وغر امات مما يؤدي الى ارتفاع كلف االنتاج ، يهدف البحث الى دراسة المرتكزات المعرفية الستراتيجية اإلنتاج األنظف وتحديد التكاليف التي يمكن تخفيضها خالل مراحل اا
... Show Moreيهدف البحث إلىبيان دور الانتاج الانظف وتأثير تطبيقه على تكاليف الوحدة الاقتصادية وادواته وتقنياته التي تساهم في دعم الميزة التنافسية المستدامة
Human wealth is the most valuable wealth on the face of the earth, and building the intellectual, cultural and scientific human being is the greatest process carried out by all religions and philosophies at all times, and the divine law aimed at reforming the earth, including in order to preserve this great wealth, and to preserve its existential and qualitative entity.
Human wealth is the most valuable wealth on the face of the earth, and building the intellectual, cultural and scientific human being is the greatest process carried out by all religions and philosophies at all times, and the divine law aimed at reforming the earth, including in order to preserve this great wealth, and to preserve its existential and qualitative entity
Toni Morrison (1931-), the first African-American winner of Noble Prize in literature (1993) and the winner of the 1988 Pulitzer Prize for fiction, regards herself as the historian of African-American people. She does not think of her writings as literature but as a sacred book dedicated to explore the interior lives of blacks. She creates history by disregarding European standards and the white man's view of African- Americans. She adopts her people's point of view, invests their heritage, voices their pains and uses their vernacular. She even writes to a black audience. She establishes the black novel by depicting the blackness of American literature. In choos
... Show Moreإدارة المخاطر في الوحدات الإقتصادية الصناعية بإستعمال مخطط باريتو
Abstract
In light of the great technological development and the emergence of globalization has increased global competition, where it became competitive exercise pressure on all sectors. In light of this companies mast enviorment depend on the means that keeps them on the competitive position through access to information about competitors in order to help them to draw a strategy that will achieve a competitive edge either through excellence or reduce the costs of their products and this means intelligence competitive and reverse engineering that help to gain information on competitors analyze and put of the decision-maker From this point formed the idea of research in the statement of the role of
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