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%.
Housing finance is one of the main components of housing, and it is relied upon to help families buy, build, add building, and housing improve. Accordingly, different countries all over the world set policies and strategies for the purpose of organizing and developing the financial sector to solve quantitative and qualitative housing problems.
This research aims to identify housing finance policies and strategies in Iraq and Baghdad governorate.
The most prominent sources of housing financing are the Real Estate Bank and the Housing Fund, and accordingly the focus has been on the role of these two institutions in filling
... Show Moreهدف البحث إلى الکشف عن العلاقة بين الصحة النفسية وتقدير الذات لدى أطفال الشوارع، تألفت عينة البحث من (50) طفلاَ وطفلة، وتم تطبيق مقياسا البحث - مقياس الصحة النفسية ومقياس تقدير الذات وهما (من إعداد الباحثة)، وقد اسفرت نتائج البحث عن إن أطفال الشوارع اظهروا مستوى منخفض في الصحة النفسية وکذلک الحال بالنسبة لتقدير الذات، فضلاً عن وجود علاقة ارتباطية موجبة دالة إحصائيا بين الصحة النفسية وتقدير الذات. وفي ضوء نتائج
... Show MoreSommaire
La question de la violence et de l'agressivité porte une importance remarquable dans l’esprit de Jean Genet qui estime le crime en le considérant comme beau. Il lui donne une valeur suprême. Il le glorifie avec ses personnages criminels. Le langage théâtral genétien est violent qui conduit à la fin à l’acte agressif, le crime et la mort. Ce théâtre qui aborde la condition humaine retrace sur la scène le chemin tragique de l’homme moderne.
... Show Moreشهد العصر الذهبي للإسلام تحول أساسي في مجال الزراعة عرف باسم "الثورة الزراعية الإسلامية" أو" الثورة الخضراء" أو "الثورة الزراعية العربية" ، وقد أتاح الوضع الاقتصادي العالمي الذي أسسه التجار المسلمون في جميع أنحاء العالم القديم ، نشر العديد من النباتات والتقنيات الزراعية بين أجزاء مختلفة من العالم ا
... Show MoreAbstract:
This research aims to know the reflection of selection of employees strategy dimensions ( selection of employees strategy standards, procedures selection of employees strategy , efficiency based on a selection of employees strategy) on human capital (knowledge, skills, abilities) in a sample of Lecturers consists of (Deans and assistants and heads of departments) in ( Baghdad University) included nine colleges and university president as total sample size (54), which represent almost 50% of the total research community of 116, was used in the light of the objectives of the research descriptive and analytical approach, has been a resolution main tool for data collection as well as the interview p
... Show MoreThe research aims to determine the nature of the effect of long . term finance with Net profit which get by the organization from a grubs of finance sources which the organization can choose among them to funding its operations it is one of the basic necessities Net income . Despite this importance , however there is a distinct lack of many Iraqi organizations in the study of the relationship effect of between these two variables and this the reaserch problem .
The data of research were obtained the annual guide of Iraqi market for securities where a data of sample of Iraqi Banks was selected which were five banks from 2004 to 2007 , most of the analysis re
... Show MoreThe study was conducted for the detection of Aflatoxin B1(AFB1) in the serum and urine of 42 early and middle childhood patients (26 male and 16 female ) with renal function disease, liver function disease, in additional to atrophy in the growth and other symptoms depending on the information within consent obtained from each patient, in addition to 8 children, apparently healthy, as the control. The technique of HPLC was used for the detection of AFB1 from all samples. The results showed that out of 42 patient children, 19 (45.2%) gave positive detection of AFB1 in the serum among all age groups patients with a mean of 0.88 ng/ml and a range of (0.12-3.04) ng/ml. This was compared with the cont
... Show MoreThe Current research aims to identify ( The effects of 4EX2 Model in Misconception of Chemical concepts and Higher Order Thinking for the Students of the Third grade average ) , To verify the objective of this research , the researchers added nul hypothesis following : There is no difference is statistically significant at the level of ( 0.05 ) between the average scores of students who studied 4EX2 Model and the average students who studied by using the Misconception of Chemical concepts and Higher Order Thinking test. The research was conducted on a sample of the average Third grade students in a Baghdad secretary for boys affiliated to the General Directorate for Educational in Baghdad Al – karkh 3 and for academic year ( 2015 – 2
... Show Moreان هدف من هذا البحث هو تحليل محتوى كتاب الفيزياء للصف الرابع العلمي و المقرر تدريسه للعام الدراسي (2018-2017). ولتحقيق هذا الهدف، و بعد مراجعة الادب السابق في ضوء مفاهيم التنمية المستدامة، تم تطوير اداة تتضمن مفاهيم التنمية المستدامة وابعادها، حيث تكونت في صورتها النهائية من 51قضية فرعية موزعة بين المفاهيم الثلاثة الساسية: الاجتماعية، والاقتصادية، والبيئية .وبعد التأكد من صدق الاداة وثباتها، تم تحليل محتوى كتاب
... Show MoreThe poetic necessity in evidence to explain Ibn Aqeel were not alike, came a statement from him as a necessity in some verses and the other came as abnormal, differentiating it from the language, but he never mentioned in some verses in which the need as a necessity,