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.
The aim of the research is to demonstrate the extent of the impact of resource consumption accounting technicality as an administrative technique that is compatible with the rapid developments and changes in the external environment, with the information it provides and scientific foundations in the allocation of indirect costs, and the identification and measurement of idle energy and its costs in a way that contributes to the rationalization of pricing decisions in economic units. In light of the intense competition and the multiplicity of alternatives, and to achieve this goal, a random sample was chosen.
The application of low order panel method with the Dirichlet boundary condition on complex aircraft configuration have been studied in high subsonic and transonic speeds. Low order panel method has been used to solve the case of the steady, inviscid and compressible flow on a forward swept wing – canard configuration with cylindrical fuselage and a vertical stabilizer with symmetrical cross section. The aerodynamic coefficients for the forward swept wing aircraft were calculated using measured wake shape from an experimental work on same model configuration. The study showed that the application of low order panel method can be used with acceptable results
The main target of this paper is to determine the optimum time for preventive maintenance on machines. Tow methods has been implemented estimating the optimum time duration for preventive maintenance . the first techniques use scheduling depending on data concerning the machine maintenance cost and halted cost from the production reach to the optimum time for maintenance which reflect the minimum cost. Where as the second techniques depends on reability function to estimate the optimum duration time which reflect the minimum cost. The tow techniques above by which we count on in fixing the preventive maintenance both give same result . we also prove that the scheduling method best than the reability function .
The importance of culture moot ( visual ) in the community , serves as the conceptual basis for the technical and aesthetic awareness , as all the fields of art represents a kind of social consciousness can not be separated from the practice of performance and awareness of it. That the link between what you do image that expresses the cognitive aspects and performance , and what is reflected on the receiver by turning the event into a set of symbols and meanings that have a correlation relationship to society , education, and other fields. Therefore must provide " material conditions and psychological " that helps the learner to interact effectively and with the active elements of the learning environment in the classroom and gain
Increasingly, public organizations in the federal state are required to work together, as well as to work with others to achieve their objectives. In Iraq there are two levels of organizations, including federal and local, and these organizations have been forced to work for many years in an environment in which the responsibility for service delivery is shared between policy makers and service providers, and between local governments and the federal government. It is sometimes difficult to manage the relationship between these organizations (federal and local) and do not always provide the best possible outcome of this relationship. This paper reviews how to manage the relationship between local administrations and
... Show MoreThis study aims to highlight the role of financial control in the development of government performance through the use of "GFS" system and its application in the service of government units, which will help them in how to use financial resources efficiently through the quality of accounting information provided by this system in the financial statements that reflect the predictability in that fiscal policy of the state through government programs and activities fee as well as to identify weaknesses and address them quickly in order to avoid wastage and loss of public money, which leads to the possibility of utilization of available financial resources of the state to effectively and efficiently, has been reached that the failure of gove
... Show MoreWireless control networks (WCNs), based on distributed control systems of wireless sensor and actuator networks, integrate four technologies: control, computer network and wireless communications. Electrostatic precipitator (ESP) in cement plants reduces the emissions from rotary kiln by 99.8% approximately. It is an important thing to change the existing systems (wireline) to wireless because of dusty and hazardous environments. In this paper, we designed a wireless control system for ESP using Truetime 2 beta 6 simulator, depending on the mathematical model that have been built using identification toolbox of Matlab v7.1.1. We also study the effect ofusing wireless network on performance and stability of the closed l
... Show MoreMost of the propositions and researches that dealt with fashions in the Middle East, specifically this region from the world, from a historical perspective have not been sufficient, and were characterized by many aspects of immature thinking, in addition, they have been varied in quality. This can be attributed to many factors including: the focus in the field of researches and Middle East studies is on languages, arts, history, and political thinking of the region. Other factors are the information asymmetry, the differences in sources and references, in addition to differences in the scientific value of these sources added to the difficulty of gathering them at the same time especially that these sources are scattered in many places wh
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This research aims to develop a unit as part of a sixth-grade Arabic language textbook and measure its effectiveness in the development of twenty-first-century skills of female students. The author adopted the experimental approach with a quasi-experimental design of the pre-post single-group. A list of the major skills was derived from the framework for the 21st-century skills of the mother tongue that was developed by the Partnership for 21st-Century Skills and reviewed and adjusted by some specialists. According to their views, the unit was developed. The study targeted 15 sub-skills falling under three main skills. The results of the study showed the effectiveness of the developed unit in the develo
... Show MoreThis study was prepared to investigate the performance and behavior of concrete thrust blocks supporting pipe fittings. In the water distribution networks, it is always necessary to change the path of the pipes at different degrees or to create new branches. In these regions, an unbalanced force called the thrust force is generated. In order to counter this force, these regions are supported with concrete blocks. In this article, the system components (soil, pipe with its bend and thrust blocks) have been numerically modeled and simulated by the ABAQUS CAE/2019 software program in order to study the behavior and stability of the thrust block with different burial conditions (several b