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OPEN CIRCUIT HEAT EXCHANGER DYNAMICS DURING FLOW REDUCTION TRANSIENT IN THEIR SECONDARY LOOPS
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An experimental and theoretical analysis was conducted for simulation of open circuit cross flow heat
exchanger dynamics during flow reduction transient in their secondary loops. Finite difference
mathematical model was prepared to cover the heat transfer mechanism between the hot water in the
primary circuit and the cold water in the secondary circuit during transient course. This model takes under
consideration the effect of water heat up in the secondary circuit due to step reduction of its flow on the
physical and thermal properties linked to the parameters that are used for calculation of heat transfer
coefficients on both sides of their tubes. Computer program was prepared for calculation purposes which
cover all the variables that affect such type of transient mechanisms. The effect of the power density in
the primary circuit and the water flow reduction percentage on the average temperature build up of the
water in the primary circuit was investigated. The elapsed time required for the primary circuit average
temperature to reach a steady state value was also calculated. These calculations were supported with
experimental measurements conducted on a standard cross flow heat exchanger apparatus. The
experimental results were compared with the theoretical results for certain power density value at
different flow reduction percentages which show a reliable agreement. This relative agreement was
necessary to consider the mathematical model with certain assurance for calculating transient parameters
for higher power densities that are out of apparatus ranges. The results proved that water average
temperature build up in the primary circuit has sharp tendency when the percentage of flow reduction in
the secondary circuit reach 25% of its nominal values.

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Publication Date
Wed Jul 31 2019
Journal Name
Journal Of Engineering
Evaluation of the Accuracy of Digital Elevation Model Produced from Different Open Source Data
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This study aims to estimate the accuracy of digital elevation models (DEM) which are created with exploitation of open source Google Earth data and comparing with the widely available DEM datasets, Shuttle Radar Topography Mission (SRTM), version 3, and Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model (ASTER GDEM), version 2. The GPS technique is used in this study to produce digital elevation raster with a high level of accuracy, as reference raster, compared to the DEM datasets. Baghdad University, Al Jadriya campus, is selected as a study area. Besides, 151 reference points were created within the study area to evaluate the results based on the values of RMS.Furthermore, th

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Publication Date
Sun Nov 27 2022
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
open-source enterprise resource planning system Odoo roll in rationalizing the costs of the Ishtar Sheraton Hotel/ applied research
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The Accommodation industry in Iraq suffers from many problems, especially after 2003, when the Accommodation industry was exposed to many crises due to the security and political situation in Iraq, which negatively affected the administrative operations inside the industry and created many problems, the most important of which are deterioration, high costs and poor performance, so some hotel administrations sought To find alternative solutions that help in the advancement of hotels, one of the proposals is to go to technology, as technology is currently one of the most important solutions to solve large complex problems, as the world has turned to automation to solve complex problems such as increasing production, reducing costs, and rai

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Publication Date
Fri Feb 12 2016
Journal Name
International Journal Of Applied Mathematical Research
The dynamics of nutrient, toxic phytoplankton, nontoxic phytoplankton and zooplankton model
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<p>The objective of this paper is to study the dynamical behavior of an aquatic food web system. A mathematical model that includes nutrients, phytoplankton and zooplankton is proposed and analyzed. It is assumed that, the phytoplankton divided into two compartments namely toxic phytoplankton which produces a toxic substance as a defensive strategy against predation by zooplankton, and a nontoxic phytoplankton. All the feeding processes in this food web are formulating according to the Lotka-Volterra functional response. This model is represented mathematically by the set of nonlinear differential equations. The existence, uniqueness and boundedness of the solution of this model are investigated. The local and global stability

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Publication Date
Sat Jan 01 2022
Journal Name
Lecture Notes In Electrical Engineering
Dynamics Modeling and Motion Simulation of a Segway Robotic Transportation System
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Publication Date
Tue Jan 16 2024
Journal Name
International Journal Of Analysis And Applications
Fear and Hunting Cooperation's Impact on the Eco-Epidemiological Model's Dynamics
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Due to the fact that living organisms do not exist individually, but rather exist in clusters interacting with each other, which helps to spread epidemics among them. Therefore, the study of the prey-predator system in the presence of an infectious disease is an important topic because the disease affects the system's dynamics and its existence. The presence of the hunting cooperation characteristic and the induced fear in the prey community impairs the growth rate of the prey and therefore affects the presence of the predator as well. Therefore, this research is interested in studying an eco-epidemiological system that includes the above factors. Therefore, an eco-epidemiological prey-predator model incorporating predation fear and

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Publication Date
Fri Feb 10 2023
Journal Name
Journal Of Applied Mathematics
The Dynamics of a Delayed Ecoepidemiological Model with Nonlinear Incidence Rate
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In this paper, the general framework for calculating the stability of equilibria, Hopf bifurcation of a delayed prey-predator system with an SI type of disease in the prey population, is investigated. The impact of the incubation period delay on disease transmission utilizing a nonlinear incidence rate was taken into account. For the purpose of explaining the predation process, a modified Holling type II functional response was used. First, the existence, uniform boundedness, and positivity of the solutions of the considered model system, along with the behavior of equilibria and the existence of Hopf bifurcation, are studied. The critical values of the delay parameter for which stability switches and the nature of the Hopf bifurcat

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Publication Date
Sun Sep 01 2019
Journal Name
Al-khwarizmi Engineering Journal
Fuzzy Analytical Hierarchy Process for Embedded Risk Reduction in Selecting the Right Planning Decision
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The aim of this work is to provide an efficient selection technique as a part of planning process to guide the decision makers to decide the preferences of one supplier over another for purchasing lab instruments in education domain. Fuzzy Analytical Hierarchy Process has used as a multi-criteria decision process, as an industrial engineering tool with certain emphasis on the qualitative aspects required to the decision makers. While the concept of degree of possibility for each criterion is used to reach its relative weights, a specific methodology created to reach the final objective decision of supplier selection. A questionnaire form was developed and distributed to five universities located in Baghdad province with a total

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Publication Date
Sat Dec 01 2018
Journal Name
Proceedings Of International Structural Engineering And Construction
ON THE REDUCTION OF PRESTRESSING FORCE NEAR SUPPORTS IN PARTIALLY PRESTRESSED CONCRETE FLEXURAL MEMBERS
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Straight tendons in pretensioned members can cause high-tensile stresses in the concrete extreme fibers at end sections because of the absence of the bending stresses due to self-weight and superimposed loads and the dominance of the moment due to prestressing force alone. Accordingly, the concrete tensile stresses at the ends of a member prestressed with straight tendons may limit the service load capacity of the member. It is therefore important to establish limiting zone in the concrete section within which the prestressing force can be applied without causing tension in the extreme concrete fibers. Two practical methods are available to reduce the stresses at the end sections due to the prestressing force. The first method based

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Publication Date
Mon Apr 01 2019
Journal Name
Journal Of Oral And Maxillofacial Surgery
Pain Reduction in Extensive Apical Surgery of the Anterior Maxilla: A Comparative Clinical Study
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Publication Date
Wed Jan 01 2020
Journal Name
Journal Of Advanced Research In Dynamical And Control Systems
A surveyon work flow in service oriented systems
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