The heat exchanger is a device used to transfer heat energy between two fluids, hot and cold. In this work, an output feedback adaptive sliding mode controller is designed to control the temperature of the outlet cold water for plate heat exchanger. The measurement of the outlet cold temperature is the only information required. Hence, a sliding mode differentiator was designed to estimate the time derivative of outlet hot water temperature, which it is needed for constructing a sliding variable. The discontinuous gain value of the sliding mode controller is adapted according to a certain adaptation law. Two constraints which imposed on the volumetric flow rate of outlet cold (control input) were considered within the rules of the proposed adaptation law in this work. These are the control input is a positive quantity, and it limited by a maximum value. The maximum allowable desired outlet cold water has been estimated as function of heat exchanger parameters and maximum control input. The simulation results demonstrate the performance of the proposed adaptive sliding mode control where the outlet cold water was forced to follow desired temperature equal to 45𝑜 . Additionally, the robustness of the proposed controller was tested for the case where the cold water inlet temperature is not constant, and also for the case of heat exchanger parameters uncertainty. The results were revealed the robustness of the proposed controller.
The aims of this reserch is identify evaluate the organizational commitment level of (emotional, standard, continuous) and the level of discipline dimensions (functional duties, professional responsibility and ethics) for medical doctors in Ramadi Teaching Hospital due to their relationship with the organization effectiveness the level of completion work and the importance of the expected results in the field respondent
sample of (50) doctors has from all branches and specialties, including specialist doctors consultants and practitioners as well as branches of residence and senior the most prominent results reached are the emotional and the st
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The research aims at the possibility of measuring the technical and scale efficiency (SE) of the departments of the College of Administration and Economics at the University of Baghdad for a period lasting 8 years, from the academic year 2013-2014 to 2018-2019 using the method of Applied Data Analysis with an input and output orientation to maintain the distinguished competitive position and try to identify weaknesses in performance and address them. Nevertheless, the research problem lies in diagnosing the most acceptable specializations in the labor market and determining the reasons for students’ reluctance to enter some departments. Furthermore, the (Win4DEAp) program was used to measure technical and scale efficiency (SE) and rely on
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The research synthesis variables of competitive advantage and the mechanism achieved by focusing on knowledge abilities and strategic of the administrative leadership, and governments and the developed countries took the racing frantically and my destiny to invest more money and resources to development of wealth and human knowledge is so choice investment winner always and who Aaikhyee never, because God Almighty give humans the abilities of all other creatures and that these abilities varying from person to person, there is the problem of search provoking questions about the essence of what it's about research and both sides theoretical and field, the objective of this research
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ABSTRACT
The research aims to identify the role of scientific planning of inventory by determining the quantity of economic demand and the number of times of purchase and associated annual total costs to achieve a sufficient and appropriate level of inventory . The research was based on the case study methodology. Materials of increasing demand in the Institute of Technical Management and knowledge of the degree of conformity of the procurement plan with the standard indicators adopted in a scientific method ,its include economic order quantity and number of purchasing times .
one of The main results of the research was the existence of a large difference between the quantity of the economic purchase of ea
The analysis of time series considers one of the mathematical and statistical methods in explanation of the nature phenomena and its manner in a specific time period.
Because the studying of time series can get by building, analysis the models and then forecasting gives the priority for the practicing in different fields, therefore the identification and selection of the model is of great importance in spite of its difficulties.
The selection of a standard methods has the ability for estimation the errors in the estimated the parameters for the model, and there will be a balance between the suitability and the simplicity of the model.
In the analysis of d
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In this investigation, deep eutectic solvent based on propionic acid and choline chloride was used to prepare polyaniline, polypyrrole, and poly(aniline-co-pyrrole) samples using chemical oxidation and polymerization. Quantum mechanical calculations were conducted using time-dependent density functional theory to determine the electronic, spectroscopic properties and structure of homopolymers and the copolymer which were compared with the respective experimental data. Furthermore, the synthesized materials were characterized using Fourier transform IR spectroscopy, scanning electron microscopy (SEM), UV-visible spectroscopy, and thermogravimetric analysis. IR and UV-visible spectra confirmed copolymerization, and SEM revealed that the copol
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The aim of this study is to shed light on the immunological effect of soluble protein extracted from Proteus mirabilis through employing the level of the enzymatic activity of superoxide dismutase ,SOD The Soluble proteins, SP1 and SP2,were extracted by using the lysozyme enzyme . The rabbit were divided into three groups. the first one was injected with SP1 , the second group with SP2 for four weeks while the third group were untreated. The results revealed that enzymatic activity of SOD was increased significantly in the fifth week of injection withSP1 in comparison with control.