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Investigation of R134a Flow Boiling Heat Transfer and Pressure Drop in the Evaporator Test Section of Refrigeration System
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This paper presents an experimental and theoretical analysis to investigate the two-phase flow boiling heat transfer coefficient and pressure drop of the refrigerant R-134a in the evaporator test section of the refrigeration system under different operating conditions. The test conditions considered are, for heat flux (13.7-36.6) kW/m2, mass flux (52-105) kg/m2.s, vapor quality (0.2-1) and saturation temperature (-15 to -3.7) ˚C. Experiments were carried out using a test rig for a 310W capacity refrigeration system, which is designed and constructed in the current work. Investigating of the experimental results has revealed that, the enhancement in local heat transfer coefficient for relatively higher heat flux 36.6 kW/m2 was about 38% compared to 13.7 kW/m2 at constant operating conditions. The enhancement in heat transfer coefficient was about 57% when the mass flux increased from 52 kg/m2.s to 105 kg/m2.s at constant test conditions. The enhancement in the heat transfer coefficient was about 64% when the saturation temperature increased from -8 to -3.7 at fixed refrigerant mass velocity and heat flux. The effect of mass velocity on pressure drop was relatively higher by about 27% than that for heat flux at specified test conditions. The comparison between the experimental and theoretical results has shown an acceptable agreement with an average deviation of 21%.

 

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Publication Date
Mon Jul 01 2013
Journal Name
2013 35th Annual International Conference Of The Ieee Engineering In Medicine And Biology Society (embc)
A preliminary investigation of the effect of force variation for myoelectric control of hand prosthesis
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Publication Date
Tue May 01 2012
Journal Name
Journal Of Engineering
Study on wind loads coefficients and flow field characteristics around the parabolic trough with stiffeners
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wind load coefficient

Publication Date
Mon Oct 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
The relationship between the central government and local administrations in the federal system: Experience the Iraqi model
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   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

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Publication Date
Mon Jun 19 2023
Journal Name
Journal Of Engineering
Effect of Design Parameters and Support Conditions on Natural Frequency of Pipe Excited by a Turbulent Internal Flow
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In this study, the effect of design parameters such as pipe diameter, pipe wall thickness, pipe material and the effect of fluid velocity on the natural frequency of fluid-structure interaction in straight pipe conveying fully developed turbulent flow were investigate numerically,analytically and experimentally. Also the effect of support conditions, simply-simply and clamped-clamped was investigated. Experimentally, pipe vibrations were characterized by accelerometer mounted on the pipe wall. The natural frequencies of vibration were analyzed by using Fast Fourier Transformer (FFT). Five test sections of two different pipe diameters of 76.2
mm and 50.8 mm with two pipe thicknesses of 3.7 mm and 2.4 mm and two pipe materials,stainles

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Publication Date
Sat Mar 26 2022
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The role of the marketing intelligence system in the quality of the insurance service : Applied research in the National Insurance Company
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The current research seeks to identify the role of the marketing intelligence system in its dimensions (customer intelligence, market intelligence, competitor intelligence, insurance product intelligence, sales representatives) and its reflection on improving the quality of the insurance service provided by the National Insurance Company represented in its dimensions (reliability, response, tangibility, Safety, the spirit of empathy, communication) adopted in the current research, and based on that, the research came as an attempt to find out the extent to which the research sample company can apply the approach of the marketing intelligence system and its impact on improving the quality of the insurance service provided to custo

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Publication Date
Fri Mar 30 2007
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Performance of Dual-Media Down-Flow Rapid Gravity Filters
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The present study was conducted to evaluate the effect of variation of influent raw water turbidity, bed composition, and filtration rate on the performance of mono (sand) and dual media (sand and anthracite) rapid gravity filters in response to the effluent filtered water turbidity and headloss development. In order to evaluate each filter pe1formance, sieve analysis was made to characterize both media and to determine the effective size and uniformity coefficient. Effluent filtered water turbidity and the headloss development was recorded with time during each experiment.

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Publication Date
Mon Sep 01 2008
Journal Name
Journal Of Engineering
MATHEMATICAL SIMULATION OF UNSTEADY FLOW THROUGH HOLLOW FIBER MEMBRANE
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Publication Date
Sat Feb 01 2020
Journal Name
Journal Of Engineering Science And Technology (jestec)
Analysis Of Sedimentation In Trunk Sewer With Laboratory Investigation Of Sewage Sediment Characteristics In Baghdad City
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Sediment accumulated in sewers is a major concern source as it induces numerous operational and environmental problems. For instance, during wet weather flow, the re-suspension of this sediment accompanied by the combined sewer overflow may cause huge pollutant load to the receiving water body. The characteristics of the sewer sediment are important as it shapes its behaviour and determines the extent of the pollution load. In this paper, an investigation of sewer sediment and its characterization is done for a case study in Baghdad city. Sediment depth covers more than 50% of the sewer cross-sectional area; several operational causes are comprised to cause this huge depths of sediment depositions. The testing and analysis of the s

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Publication Date
Sat Sep 08 2018
Journal Name
Modeling Earth Systems And Environment
Sedimentary units-layering system and depositional model of the carbonate Mishrif reservoir in Rumaila oilfield, Southern Iraq
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Publication Date
Tue Jun 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
The role of business incubators represented by the banking system in financing small and medium enterprises in Iraq for the period 2000-2010
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The process of transformation from the central economy to a free economy requires restructuring the economy according to a new economic philosophy that relies on activating the role of private economic activity in which private and medium-sized institutions occupy an essential axis for their active role in the economies of all countries, especially those countries that have directed towards the market mechanism and sector leadership. The special process of economic development and the role that commercial banks can play in advancing the financing of these projects by establishing specialized business incubators for financing.

What encouraged countries to pay attention to these institutions is the ease of

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