Preferred Language
Articles
/
alkej-311
Experimental Study Using the Passive Solar Chimney for Evaporative Cooling With PCM and CFM as a Thermal Energy Storage
...Show More Authors

 

      In this work, a test room was built in Baghdad city, with (2*1.5*1.5) m3  in dimensions, while the solar chimneys (SC) were designed with aspect ratio (ar) bigger than 12. Test room was supplied by many solar collectors; vertical single side of air pass with ar equals 25, and tilted 45o double side of air passes with ar equals 50 for each pass, both collectors consist of flat thermal energy storage box collector (TESB) that covered by transparent clear acrylic sheet, third type of collector is array of evacuated tubular collectors with thermosyphon in 45o instelled  in the bottom of TESB of vertical SC. The TESB was made from metallic iron sheets as a shell and fuelled by paraffin wax as phase change material (PCM). The PCM supported by copper foam matrix (CFM) to enhance thermal conductivity of wax. When heat is released from TESB to the air, a buoyancy force will be generated in chimney gaps. Then a difference in pressure between inside and outside test room leads to induce the air flow to test room through wet corrugated cellulose pad, where evaporative cooling (EC) occurs. Results of experimental work, that achieved in June, for 12 to24 hour in the test day, refer to effectiveness using EC to decrease the room temperature comparing. The system reduces test room temperature of up to 8.5~9.2 oC in 11:00 am to 3:00 pm and at highest effectiveness of EC, while minimum reduces in temperature of up to 3.5 oC in 8:00pm to 3:00 am. Also, the results showed the affectivity to using the TESB, during the night time for ventilation and EC, with lower effectiveness than from day time. The range of EC effectiveness equals 30.5-37.5 with a natural vent, while The maximum air change per hour (ACH) equals (3.8-6.187), and the maximum mass flow rate is equal to (36.651 kg.hr-1) at experimental evaluation of the system’s discharge coefficient value 0.371.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Sun Jul 26 2026
Journal Name
Karbala Journal Of Physical Education Sciences
تأثير تمرينات وقائية للذراعين في تطوير بعض القدرات البدنية للاعبي المنتخب الوطني بكرة السلة على الكراسي المتحركة
...Show More Authors

View Publication Preview PDF
Publication Date
Sun Jun 18 2023
Journal Name
Arab Science Heritage Journal
أشهر العلماء العرب المسلمين وإسهاماتهم في علم الفلك من خلال كتاب سير أعلام النبلاء للذهبي (ت748هـ / 1348م)
...Show More Authors

The Arabs muslim , throughout the historical ages, had many and varied contributions in various fields of science and knowledge, and in all scientific disciplines. They were preceded by scholars of other sects, so their books were translated into Arabic and they added to it many of their scientific research and writings that affected Arab and Islamic libraries, as these scientific research turned into basic references for the benefit of students of science in this field, and they did not stop at that, but built observatories, and invented They developed many astronomical devices in their time and observed the planets and stars, drew maps for them and determined their locations

View Publication Preview PDF
Publication Date
Wed Dec 18 2024
Journal Name
مجلة كلية التربية الأساسية - الجامعة المستنصرية
تأثير تزامن تدريبات السايكو بتمرينات القوة الوظيفية في القدرة الانفجارية للرجلين والمناولة الطويلة والركلة الركنية بكرة القدم
...Show More Authors

هدف البحث إعداد تدريبات تزامن ما بين السايكو وتمرينات القوة الوظيفية للاعبي كرة القدم، والتعرف على تأثيرها في القدرة الانفجارية للرجلين، وفي مهارتي المناولة الطويلة والركلة الركنية للاعبي كرة القدم، ليفترض الباحث بإنه توجد فروق ذات دلالة إحصائية بين نتائج الاختبارات القبلية والبعدية لمجموعتي البحث التجريبية والضابطة في كل من القدرة الانفجارية للرجلين لمهارتي المناولة الطويلة والركلة الركنية في كرة القد

... Show More
View Publication
Publication Date
Wed Oct 04 2023
Journal Name
Arab Science Heritage Journal
المدراس الثانوية في الاعظمية ( ثانوية كلية بغداد- ثانوية الأعظمية للبنين – ثانوية الأعظمية للبنات - ثانوية الحريري للبنات) أنموذجاً
...Show More Authors

Education received the attention of the monarchy in Iraq, especially after the developments that the country witnessed after Iraq gained independence and joined the League of Nations in 1932 AD in all political, economic and cultural aspects.  In this regard, due to its distinguished geographical location, where the atmosphere, the natural environment and the religious and political standing were available, which made it a center of attraction for most Iraqi families and political figures.  Learning and pioneering the path of knowledge, so it witnessed a great prosperity in secondary education, so several important schools appeared that contributed to advancing the wheel of learning forward, including Baghdad College High Schoo

... Show More
View Publication Preview PDF
Publication Date
Tue Jan 01 2008
Journal Name
Alustath Journal For Human And Social Sciences
أثر المنشطات العقلية في أستراتيجيات التعلم و الدراسة و أنماط المعرفة الفيزيائية لدى طالبات الصف الرابع العام
...Show More Authors

Preview PDF
Publication Date
Mon Mar 15 2021
Journal Name
Al-academy
Effect of Teaching Competencies in Enhancing Self-Confidence among Students of Department of Art Education during Application: كنعان غضبان حبيب
...Show More Authors

The results of previous scientific studies showed that knowledge is something and application is something else, that's why teachers' preparation programs focused, in the present time, on special standards for knowledge and performance, i.e., who has knowledge is not necessary able to apply it in his life or in his field of work, which led to the existence of a gap between knowledge and application. Based on that, those interested in (teachers' preparation) reconsidered their work evaluation, thus the concept of competency appeared at the end of the sixties of the past century to address the negative in teachers' preparation.
The following contains a number of competency features in teachers' preparation programs:
Teachers' effec

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Oct 01 2020
Journal Name
Journal Of Physical Education (20736452)
تأثير التدريبات التكتيكية على اللعب السريع حسب التحمل اللاهوائي في تطور السرعة لدى لاعبي كرة القدم الشباب.
...Show More Authors

View Publication
Publication Date
Fri Jul 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Reflections informational monitoring in Creative marketing systems
...Show More Authors

Abstract:                                                                                                      

         The research aims to measure the impact of infor

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Jul 01 2019
Journal Name
المجلة المصرية لبحوث الأعلام
دوافع تعرض طلبة أقسام اللُّغة الإنکليزية في جامعة بغداد للقنوات الفضائية الناطقة باللُّغة الإنکليزية والإشباعات المتحققة عنه:
...Show More Authors

تلخصت مشکلة هذا البحث في التعرف على الدوافع التي تقف وراء تعرض الطلبة الدارسين في أقسام اللُّغة الإنکليزية للقنوات الفضائية الناطقة باللُّغة الإنکليزية والإشباعات المتحققة عن هذا التعرض في هذا المجتمع الخاص الذي يشکل بيئة اجتماعية علمية محددة، عن طريق تطبيق نظرية الإستخدامات والإشباعات في إطار المجتمعات الخاصة، وسعى هذا البحث إلى تحقيق ثلاثة أهداف هي، قياس استخدامات لطلبة الدارسين في أقسام اللُّغة الإنک

... Show More
View Publication Preview PDF
Publication Date
Fri Feb 08 2019
Journal Name
Iraqi Journal Of Laser
One dimensional Finite Element Solution of Moving Boundaries in Far IR Laser Tissue Ablation
...Show More Authors

In this work, the finite element analysis of moving coordinates has been used to study the thermal behavior of the tissue subjected to both continuous wave and pulsed CO2 laser. The results are compared with previously published data, and a good agreement has been found, which verifies the implemented theory. Some conclusions are obtained; As pulse width decreases, or repetition rate increases, or fluence increases then the char depth is decreased which can be explained by an increase in induced energy or its rate, which increases the ablation rate, leading to a decrease in char depth. Thus: An increase in the fluence or decreasing pulse width or increasing repetition rate will increase ablation rate, which will increase the depth of cut

... Show More
View Publication Preview PDF