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Article
COMPARISON OF COOLING LOAD CALCULATION METHODS BY

Author: Khalid A. Joudi
Journal: Al-Fatih journal مجلة الفتح ISSN: 87521996 Year: 2005 Volume: 1 Issue: 24 Pages: 57-61
Publisher: Diyala University جامعة ديالى

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Abstract

The present work includes cooling load measurement in Iraq. One room located in Baqubah was the object of the study. The measurement was taken for the room in summer months of 2004 (i.e. in May, June, July, August & September). The area of test room was 15 m2 and 3 m ceiling height with medium weight construction specifications. The test room includes exterior east and west wall facing, un-conditioning adjacent space with an exterior roof, east window and an exterior west door. The air conditioner unit used in this work was a window type with a nominal capacity of 2 T.R. (7 kW). The theoretical cooling load was predicted by three methods of cooling load calculation, which are TFM, CLTD/SCL/CLF & TETD/TA methods. Measurement of cooling load showed that there is a large difference between the measured and predicted cooling load with all theoretical methods. The difference ranged from 33% to 40%. This large difference is appear because of the several season such as the air conditioner type, suffer environmental and the construction specification of the test room where it’s represent the Iraqi building and not exactly same as building specification tabulated in ASHRAE tables

,يعنى هذا البحث بإجراء قياسات عملية لحساب حمل التبريد في العراق. غرفة الاختبار الواقعة في مدينة بعقوبة كانت مشروع الدراسة حيث أخذت القياسات خلال اشهر الصيف (أيار, حزيران, تموز, آب و أيلول). و كانت مساحة غرفة الاختبار 15م2 مع ارتفاع 3م للسقف مع مواصفات إنشاء ذات تركيب متوسط. تشمل غرفة الاختبار جداران خارجيان أحدهما مواجه للشرق و الآخر مواجه للغرب مع حيز مجاور غير مكيف مع سقف خارجي و كذلك شباك مواجه للشرق و باب خارجية مواجه للغرب. و قد كانت منظومة التكييف التي لتبريد هذه الغرفة تم استخدام وحدة تبريد جدارية سعة 2طن تثليج (7كيلو واط). أجريت الحسابات النظرية لحمل التبريد بثلاث طرق لحساب حمل التبريد و هي طريقة دالات التحويلTFM وطريقة حمل التبريد من فرق درجات الحرارة (CLTD) بالإضافة إلى طريقة فرق درجات الحرارة الكلي المكافئ (TETD). أظهرت النتائج العملية لحسابات حمل التبريد للغرفة أن هناك فرق في الحمل كبير نسبيا بين النتائج العملية و النتائج النظرية و الفرق يتراوح بين 33% إلى 40%.


Article
Characterization of CdS:In/Si Heterojunction Solar Cells

Authors: S.K. Al-Ani --- R.A. Ismail --- H.F. Al-Ta’ay
Journal: Iraqi Journal of Applied Physics المجلة العراقية للفيزياء التطبيقية ISSN: 18132065 23091673 Year: 2005 Volume: 1 Issue: 2 Pages: 13-17
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

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Abstract

In this work, CdS:In/Si anisotype heterojunction solar cells prepared by thermal evaporation technique of CdS thin films on monocrystalline silicon substrate have been fabricated, characterized and analyzed. Cells aparameters dependencies on the indium diffusion temperature were reported. The amximum obtained conversion efficiency was 8% at 93mW/cm2 (AM1) for cells made with indium diffusion temperature of 300°C. these cells are made without using antireflecting coatings and grid contacts.


Article
Effect of Active Medium Temperature on the Output Characteristics of Pulsed Free-Running R6G and RB Dye Laser

Author: M.A. Ahmed
Journal: Iraqi Journal of Applied Physics المجلة العراقية للفيزياء التطبيقية ISSN: 18132065 23091673 Year: 2005 Volume: 1 Issue: 1 Pages: 30-33
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

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Abstract

In this work, the effect of active medium temperature on output characteristics of a pulsed dye laser was studied. Two dyes, R6G and RB, were used as laser active medium. Under free-running operation, 35mJ maximum output energy and 100Ps pulse duration were obtained with presence of oxygen as a quencher. Results presented in this work showed that output characteristics such as laser pulse energy, emission linewidth, beam divergence and overall efficiency are reasonably affected by temperature. Optimum values of such features requires system to operate at temperature of 10°C which represents the optimum operating temperature. These results may benefit to determine the optimum operating temperature of a pulsed dye laser due to system design considerations.

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