The distribution of chilled water flow rate in terminal unit is a major factor used to evaluate the performance of central air conditioning unit. In this work, a theoretical chilled water distribution in the terminal units has been studied to predict the optimum heat performance of terminal unit. The central Air-conditioning unit model consists of cooling/ heating coil (three units), chilled water source (chiller), three-way and two-way valve with bypass, piping network, and pump. The term of optimization in terminal unit ingredient has two categories, the first is the uniform of the water flow rate representing in statically permanents standard deviation (minimum value) and the second category is the maximum heat transfer rate from all terminal units. The hydraulic and energy equations governing the performance of unit solved with the aid of FORTRAN code with considering the following parameters: total water flow rate, chilled water supply temperature, and variable valve opening. It was found that the optimum solution of three-way valve case at 8°C water supply temperature, 0.12 kg/s total water flow rate and valve opening order (valve 1: 100%, valve 2: 100% and valve 3: 75%) with total heat rate (987.92 Watt) and standard deviation (1.181E-3). Also, for the two-way valve case the results showed that the optimum condition at 8°C water supply temperature, 0.12 kg/s total water flow rate and valve opening order (valve 1: 75%, valve 2: 75% and valve 3: 50%) with total heat rate and standard deviation (717Watt) and (5.69E-4) respectively.
مشكلة البحث واهميته:
نتيجة لما يشهده قطاع التربية من تغير كبير وتطور سريع, فقد اتجه تخطيط السياسة التعليمية في القطر نحو تحديد كفاءة النظام التعليمي بمختلف مراحله كونها اجزاء متداخلة في تركيب تنظيمي واحد(9: 3 ) . وذلك من اجل استمرار تطويره, وتوجيهه بما يتفق واحداث المرحلة ومتطلباتها, على اساس ان مخرجات كل مرحلة تعليمية من مراحله المتتابعة تمثل المدخلات الجديدة لمرحلة تعليمية لاحقة.
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... Show MoreAnalysis of the main financial statements (financial position, income, cash flow) using the analysis tools gives a clear picture of the results of the annual activity of the economic units, which contribute to the development of future plans and programs and identify weaknesses in the work of economic units including banks. Therefore, the indicators used in the analysis Would be feasible for the rest of the other sectors. such as Central Bank , Security exchange market , which will accordingly contribute in National product , determining market requirements , investor’s desires , knowing economic situation and providing liquidity in a timing manner.
The current research aims know:
1.-level application managers secondary schools and junior high for the tasks set by the high school system in Iraq, from the standpoint of teachers.
- statistically significant differences in the extent of the application of secondary school principals and junior high for the tasks set by the high school system from the viewpoint of teachers depending on the variable (sex, specialty, number of years of service).
The researcher used the descriptive analytical method being considered best suited to such studies, for the purpose of achieving the goals of research, the researcher using the questionnai
... Show MoreThe aim of the research is to highlight the income tax by direct deduction in Iraq and the most important problems and obstacles faced by this type of taxes and identify the reasons for the clear and striking differences in the deduction between those charged with the state departments to reach the exact calculation in accordance with the laws and instructions and the unification of tax deductions for similar cases and clarify Cases of confusion and ambiguity, and achieving justice by deduction, whether in favor of the taxpayer or financial authority. Under the laws and regulations in force.
The study was conducted on a sample of the salaries of the employees of the University of Basra, and interviews with account m
... Show MoreThe current research aims to identify the impact of the amputated story style in the collection of sixth graders in elementary in the written expression subject.
The researcher, intentionally, chose Al-Ameen primary hybrid school which belongs to the directorate of education in Baghdad / Karkh first. The number of people of the sixth grade three classes. The researcher chose the two classes randomly to represent one of the experimental group, the number (32) pupils (male and female) have studied the expression subject by the amputated story style. Other control group, the number (32) pupils studied according to the traditional method.
The researcher prepared the lesson plans and presented to the experts, the researc
... Show MoreBackground: A number of different types of fluid may accumulate in the pleural space, the most common being transudate, exudate (thin or thick), blood and chyle. All types of pleural effusion are radio graphically identical, though historical, clinical and other radiological features may help limit the diagnostic possibilities. Sometimes, also CT and MRI can help to specify the diagnosis.
Objective: To determine the accuracy of computed tomography (CT) in enabling differentiation of pleural exudates from transudates.
Patients and methods: forty three consecutive patients (43 effusions) underwent contrast-enhanced CT. Thoracocentesis was performed to measure pleural and serum total protein values. Effusions were classified as exudat
The research dealt with the financial policies adopted by Almurabitin (484-520 / 1092-1143) and Almuahadin (540-620 / 1145-1223) in Andalusia, their characteristics, and how they dealt with increasing the resources of Bayt Almal and organizing the spending process. The first axis of the research discussed the policies of the management of public funds in the provinces of Almurabitin and Almuahadin in Andalusia. While the second presented to the most prominent and most important resources of Andalusia financial in the era of these two countries such as Zakat, Alkhiraj, Alghanayim, confiscations and illegal taxes and others. The third axis reviewed the public spending policies of the two countries and the political and military conditions
... Show MoreThis study aims to find the effectiveness of GeoGebra software in the achievement and habits of mind of eighth grade female students.
The research sample consisted of (62) students and divided into two groups. The first one is the experimental group (35 students) and it was taught using GeoGebra software, and the second group is the standard group (27 students) and it was taught using the traditional method of teaching. Two multiple-choice-question tests were prepared, one of them tests the achievement (40 paragraphs) and the other tests the habits of mind (24 paragraphs) and comprises four habits of mind according to Costa and Kallick classificatio
... Show MoreFrom this research ,it can be concluded that Ibn al-Jawzi touch on the subject of dreams , dignities and paranormal part of his curriculum, which he ontinued on his book, as it is an important part of the elements of translation, we find first special attention and promise of things recognized when responding with them in most of the cases in which they received, including proximity He pointed out to an important point through dreams, dignities.