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.
Chapter One – introduction
Nations managed today to achieve progress in the field of modern technology. Science has changed many beliefs and trendiness that people have held for long time, skills and scientific thinking developed, and made scientific observation and experiment replace narration and taking from others. That is attributed to examining the educational systems searching for the locations of defect, and shortage.
In the light of educational modernizations, many models of teaching incliuding a model for social tracing attributed to Herbart Thelen, which is a model to develop skills of social participation in the democratic process (Al-Khawalda,1993,335).
... Show Moreإمتاز ابن حجر بعلميته ، وغزارة عطائه في وضع كتب قيمة وتصانيف موسوعية فكانت كتبه هذه يشار لها بالبنان .
اعتنى الكثير من العلماء فاحتلت المرأة مكانة متميزة في كتبهم وخصصوا لمعطياتها أجزاء واضحة ضمن مؤلفاتهم ويعد أبن حجر أحد هؤلاء العلماء الافذاذ الذين اعتنوا بالمرأة ، وهذا يعني انه أفرد لها جزءاً خاصاً بها سماه ( كتاب النساء) وهو يقع ضمن الجزء الرابع من كتابه ، على الر
... Show MoreAnalytical Hierarchy Process (AHP) belongs to the family of Multiple Criteria Decision Making (MCDM) and has, recently, received a wide popularity in decision making regarding supplier selection. The objective of this study is to apply the methodology of AHP on selecting suppliers to supply materials for the Geological Survey and Mining Company (GSMC). Criteria for rating the suppliers and pairwise comparisons were identified by the members of the Tenders Analysis Committee (TAC). In order to judge the internal validity of the AHP, it was applied manually on a sample of fourteen tenders that were analyzed and executed between 2004-2007, then an interactive computerized package was developed
... Show Moreللدراسات التاريخية أهميتها ولاسيما دراسة المؤلفات الذي يعطينا صورة كاملة عن تطور الواقع التاريخي للمرحلة التي عاصرها المؤلف وتكتب دراسة الشخصيات العلمية طابعاً خاصاً ومهم يدفعنا إلى التعريف بالمؤرخ ومنهجه في الكتاب والموارد التي استقى معلوماتهِ منها .
The world witnessed variables influenced on entirely education essential mean to grantee the required adaption of inner and external motivations circumstances this gives us opportunity of the best selection means to achieve the goals for progress individual and community .
From here appeared the needs of scientific study interest in new styles of education locate the old place that become non able to granting students and their tendency n
... Show MoreThe research revolves around the methodology of the historian Ibn Wasil
(d.697 AH) in dealing with the Mongolian invasion through his book
“Mafrej al-Karroub fi Akhbar Bani Ayyub
The poet dependent formation of a caupillary to stimuli ,sensory based on the areas of cognition in cluding raises every sense in the mind of therecipient , taking advantage of the senses which help him to perception and imagination and photography .i wanted in my Research that showed silent in the poetry of muslim Ibn al walid by the method of use the senses and then method of imaging divided the research to the axes according to topics hair began to praise ,I have found through mating poetic image with silent about the poet in the purpose of praise that he wanted . the caliphate of yazidI bnmazidknignt courageous , and thisis found in the clear signals in the poems silent poet what he wanting saying . The purpose that I choose to look out
... Show MoreThis study Concentrates on modern variable in the human resources management that is Core Competency.
The field study is two of Public organizations, The first is Educational Baghdad Hospital, the other is the state Company for Batteries industry, the problem of the study determincs some questions and hypotheses. The data was Collected by questionnaire which Contains six Core Competences leader ship, Communication, frontline execution, development, innovation and self management .
The sample contains (26) doctores and (28) heads of departments in the company.
The study points out many conclusions, the main of it, there is significant differences amon
... Show MoreStudied competence spam to malicious moth figs at temperatures and Kagafat host different results showed that female intruder, despite their ability to shell larvae host and when densities of different, but it is able to lay eggs at a temperature of 14 + or -1 and finally urged the efficiency spam to malicious affected heavily host and that the greater the intensity of the host spam increased efficiency and its performance life
The Fylex extract exert a high inhibition effect against A . flavus growth on PDA medium, as the fungus growth was completely inhibited by 100% at a concentration of 0.2 and 0.3% of studied extract, while the lowest inhibition percentage (71%) was found at a concentration of 0.1%. Whereas magnesium oxide nanoparticles showed the highest inhibition ratio of A. flavus (100%) was detected at 0.2% and the lowest inhibition ratio (81.66%) was at concentration 0.5%. Moreover, the addition of G. lucidum powder to PDA medium with a concentration of 2.5 mg increased the inhibition rate of A. flavus growth which was 54.4%, while the lowest inhibition ration (18.22%) was found at a concentration of 1000 mg. The milky liquid (brocade milk) of Calotropi
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