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Modeling and Simulation of Thermal Performance of Solar-Assisted Air Conditioning System under Iraq Climate
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In Iraq most of the small buildings deployed a conventional air conditioning technology which typically uses electrically driven compressor systems which exhibits several clear disadvantages such as high energy consumption, high electricity at peak loads. In this work a thermal performance of air conditioning system combined with a solar collector is investigated theoretically. The hybrid air conditioner consists of a semi hermetic compressor, water cooled shell and tube condenser, thermal expansion valve and coil with tank evaporator. The theoretical analysis included a simulation for the solar assisted air-conditioning system using EES software to analyze the effect of different parameters on the power consumption of compressor and the performance of system. The results show that refrigeration capacity is increased from 2.7 kW to 4.4kW, as the evaporating temperature increased from 3 to 18 ºC. Also the power consumption is increased from 0.89 kW to 1.08 kW. So the COP of the system is increased from 3.068 to 4.117. The power consumption is increased from 0.897 kW to 1.031 kW as the condensing temperature increased from 35 ºC to 45 ºC. While the COP is decreased from 3.89 to 3.1. The power consumption is decreased from 1.05 kW to 0.7kW as the solar radiation intensity increased from 300 W/m2 to 1000 W/m2, while the COP is increased from 3.15 to 4.8. A comparison between the simulation and available experimental data showed acceptable agreement.

 

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Publication Date
Tue Jan 30 2024
Journal Name
Iraqi Journal Of Science
Oscillation and Asymptotic Behavior of a Three-Dimensional Half-Linear System of Third-Order of Neutral Type
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     In this paper, the oscillatory properties and asymptotic behaviour of a third-order three-dimensional neutral system are discussed.  Some sufficient conditions are obtained to ensure that all bounded positive solutions of the system are oscillatory or non-oscillatory.  On the other hand, the non-oscillatory solutions either converge or diverge when  goes to infinity. A special technique is adopted to include all possible cases. The obtained results include illustrative examples.

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Scopus Crossref
Publication Date
Sun Jul 09 2023
Journal Name
Journal Of Engineering
The Effect of Ceramic Coating on Performance and Emission of Diesel Engine Operated on Diesel Fuel and Biodiesel Blends
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In this work, the effect of ceramic coating on performance, exhaust gas temperature and gases emissions of diesel engine operated on diesel fuel and biodiesel blends was investigated. A conventional four stroke, direct injected, single cylinder, diesel engine was tested at constant speed and at different load conditions using diesel fuel and biodiesel blends. The inlet and exhaust valves, the head of piston and cylinder head of the engine were coated by ceramic materials. Ceramic layers were made of (210-240) μm of Al2O3 and (30-60) μm of 4NiCr5Al as a bond coat for inlet and exhaust valves and (350-400) μm of YSZ and (50-100) μm of 4NiCr5Al as a bond coat for head of piston and (280-320) μm of Sic and (40-80) μm of 4NiCr5Al as a b

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Crossref
Publication Date
Thu Dec 31 2015
Journal Name
Al-khwarizmi Engineering Journal
Prediction of Performance Equations for Household Compressors Depending on Manufacturing Data for Refrigerators and Freezers
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Abstract

 A surface fitting model is developed based on calorimeter data for two famous brands of household compressors. Correlation equations of ten coefficient polynomials were found as a function of refrigerant saturating and evaporating temperatures in range of (-35℃ to -10℃) using Matlab software for cooling capacity, power consumption, and refrigerant mass flow rate.

Additional correlations equations for these variables as a quick choice selection for a proper compressor use at ASHRAE standard that cover a range of swept volume range (2.24-11.15) cm3.

The result indicated that these surface fitting models are accurate with in ± 15% for 72 compressors model of cooling cap

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Publication Date
Thu Sep 30 2021
Journal Name
Journal Of Economics And Administrative Sciences
HRA and its Impact on Employees Performance: A Field Research in the Ministry of Education
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          The research aims to determine the impact of Human Resources Accounting (HRA) on employee’s performance. The research’s problem was embodied in the lack of interest in HRA, which was reflected on the performance of employees in the Ministry of Education; the research adopted the descriptive-analytical approach, and the research community included the directors of departments and people at the headquarters of the Ministry of Education. The sample size was (224) individuals from the total community of 533. The questionnaire was adopted as the main tool for collecting data and information, as well as the interviews that were conducted by the researcher. In order to analyze t

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Crossref
Publication Date
Tue Feb 12 2019
Journal Name
Iraqi Journal Of Physics
Calculated the diffuse and direct parts of global solar radiation in Baghdad city for the period (1983-2005) depending on clearness index by applying the two world models of Liu -Jordan
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In this paper solar radiation was studied over a region of Baghdad (Latitude 33.3o and longitude 44.4o). The two parts of global solar radiation: diffuse and direct solar radiation were estimated depending on the clearance index of measured data (Average Monthly mean global solar radiation). Metrological data of measured (average monthly mean diffuse and direct solar radiation) were used to comparison the results and show the agreement between them. Results are determined by applying Liu and Jordan two models (1960). Excel 2007program is used in calculation, graphics and comparison the results.

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Crossref
Publication Date
Fri Nov 10 2023
Journal Name
2023 3rd International Scientific Conference Of Engineering Sciences (isces)
Using User Experience Metrics for Academic Management System of University of Baghdad
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Interface evaluation has been the subject of extensive study and research in human-computer interaction (HCI). It is a crucial tool for promoting the idea that user engagement with computers should resemble casual conversations and interactions between individuals, according to specialists in the field. Researchers in the HCI field initially focused on making various computer interfaces more usable, thus improving the user experience. This study's objectives were to evaluate and enhance the user interface of the University of Baghdad's implementation of an online academic management system using the effectiveness, time-based efficiency, and satisfaction rates that comply with the task questionnaire process. We made a variety of interfaces f

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Scopus Crossref
Publication Date
Sun Dec 31 2023
Journal Name
International Journal On Technical And Physical Problems Of Engineering
A Multiple System Biometric System Based on ECG Data
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A Multiple System Biometric System Based on ECG Data

Scopus
Publication Date
Sun Jan 16 2022
Journal Name
Applied Sciences
Evaluation of Different Internal Designs of Hydraulic Nozzles under an Accelerated Wear Test
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The use of worn-out agricultural nozzles in pesticide application has a negative effect on the efficiency and cost of the application process. It also has an effect on environmental pollution due to an excessive amount of pesticide being applied when spraying with worn-out nozzles. In this paper, the resistance to wear of three different internal design hydraulic nozzles was ascertained. Changes in the flow rate and spray distribution as a result of this wear were also investigated. The wear test was done inside a closed system, and it was accelerated using an abrasive material to generate 100 h of wear. The tested nozzles were the Turbo TeeJet (TT)-twin chambered, Turbo Twinjet (TTj60)-dual outlet, and Drift Guard (DG)-pre-orifice.

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Scopus (4)
Crossref (3)
Scopus Clarivate Crossref
Publication Date
Sat Oct 30 2021
Journal Name
Iraqi Journal Of Science
Numerical Solution of Energy Equation in Porous Channels under Effects of Radiation Field
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     In this paper, we built a mathematical model for convection and thermal radiation heat transfer of fluid flowing through a vertical channel with porous medium under effects of horizontal magnetic field (MF) at the channel. This model represents a 2-dimensional system of non-linear partial differential equations. Then, we solved this system numerically by finite difference methods using Alternating Direction Implicit (ADI) Scheme in two phases (steady state and unsteady state). Moreover, we found the distribution and behaviour of the heat temperature inside the channel and studied the effects of Brinkman number, Reynolds number, and Boltzmann number on the heat temperature behaviour. We solved the system by buildi

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Scopus (2)
Crossref (1)
Scopus Crossref
Publication Date
Sun Feb 01 2015
Journal Name
Journal Of Engineering
Non-Linear Analysis of Laminated Composite Plates under General Out-Of-Plane Loading
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The theoretical analysis depends on the Classical Laminated Plate Theory (CLPT) that is based on the Von-K ráman Theory and Kirchhov Hypothesis in the deflection analysis during elastic limit as well as the Hooke's laws of calculation the stresses. New function for boundary condition is used to solve the forth degree of differential equations which depends on variety sources of advanced engineering mathematics. The behavior of composite laminated plates, symmetric and anti-symmetric of cross-ply angle, under out-of-plane loads (uniform distributed loads) with two different boundary conditions are investigated to obtain the central deflection for mid-plane by using the Ritz method. The computer programs is built using Ma

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