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Experimental Investigation of Heat Transfer Enhancement in a Double Pipe Heat Exchanger Using Compound Technique of Transverse Vibration and Inclination Angle
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Numerous tests are recently conducted to assess vibration's role in accelerating the heat transfer rate in various heat exchangers. In this work, the enhancement of heat transfer by the effect of transfer vibration and inclination angles on the surface of a double pipe heat exchanger experimentally has been investigated. A data acquisition system is applied to record the data of temperatures, flow rates, and frequencies over the tests. A compound technique was adopted, including the application of a set of inclination angles of (0°, 10°, 20°, and 30°) under the effect of frequency of vibration ranging from sub-resonance to over-resonance frequencies. The results showed that the overall heat transfer coefficient enhances by applying the compound technique at all the working fluid's temperatures and flow rate ranges. The maximum increase in overall heat transfer coefficient occurs at an angle of 30° and the resonance frequency. Moreover, the effectiveness of the double pipe heat exchanger gradually expanded when temperature, inclination angles, and vibration amplitude rosed. But the effectiveness value declined as the hot working flow rate increased considerably. Finally, the enhancement factor demonstrated that the combined strategy (vibration frequencies and inclination angles) had been the most effective technique in improving and enhancing heat transfer and was superior to the other ways. Additionally, the extremes improvement in overall heat transfer coefficient, effectiveness, and enhancement factor are 183.4, 191, and 164.4 %. The improvement was situated at the resonance frequency with a 30° inclination angle.

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Publication Date
Wed Dec 18 2019
Journal Name
Baghdad Science Journal
Modeling Human Capital Impact on the Development of the Iraqi Oil Industry
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Iraq has the second largest proven oil reserves in the world. According to oil experts, it is expected that the Iraq's reserves to rise to 200+ billion barrels of high-grade crude.

Oil is a strategic commodity for producing and exporting countries in general, and Iraq in particular, as demonstrated by the international experience that oil is an important means to achieve economic growth, an important tool in the overall economic, social and political development. It is also an important source of hard currency for any national economy and a means to connect the local economy and the global economy. In this paper we focus our attention on selecting the best regression model that explain the effect of human capita

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Publication Date
Sat Mar 31 2018
Journal Name
Journal Of Engineering
Estimation of Minimum Miscibility Pressure for 〖CO〗_2 Flood Based on EOS
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CO2 Gas is considered one of the unfavorable gases and it causes great air pollution. It’s possible to decrease this pollution by injecting  gas in the oil reservoirs to provide a good miscibility and to increase the oil recovery factor. MMP was estimated by Peng Robinson equation of state (PR-EOS). South Rumila-63 (SULIAY) is involved for which the miscible displacement by  is achievable based on the standard criteria for success EOR processes. A PVT report was available for the reservoir under study. It contains deferential liberation (DL) and constant composition expansion (CCE) tests.  PVTi software is one of the (Eclipse V.2010) software’s packages, it has been used to achieve the goal.

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Publication Date
Sat Oct 20 2018
Journal Name
Journal Of Economics And Administrative Sciences
Measuring the performance of government units according to the government accounting system
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Abstract

This study aims at clarifying the current performance appraisal system in government units and the extent to which they contribute to the development of the performance of these units by evaluating and measuring the performance of these units on an ongoing basis to subject their services to an assessment and measurement process in order to improve the efficiency of these units to reach their objectives efficiently and effectively. (Iraqi hospitals) by trying to determine the possibility of the government accounting system in the process of evaluating performance, through the comparison of financial performance for successive years and different hospitals using the financial and non-financial model of the evaluati

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Publication Date
Thu May 25 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Phonon Confinement Effect on Lattice Thermal Conductivity of Zn4Sb3 Quantum Well Structure
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We have theoretically investigated the in-plane lattice thermal conductivity of Zn4Sb3single quantum well structure taking into account spatial confinement of phonons. The calculations were carried out for free-surface quantum wells with thickness 8.5nm in the room temperature. We show that the lattice thermal conductivity is a significant reduce. The reduction is mostly due to the drop in the average group velocity caused by the spatial confinement of acoustic phonons and the corresponding increase in phonon relaxation rates. The predicted decrease is important for the anticipated applications of Zn4Sb3 nanostructure materials for room-temperature thermoelectric devices. Our theoretical results are in a good agreement with available exp

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Publication Date
Mon Jan 29 2018
Journal Name
Iraqi Journal Of Science
Diagnostics of Magnesium-Aluminum alloy plasmas produced by laser induced breakdown spectroscopy
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In this work, the Al-Mg alloys plasma plume that produced under vacuum (10-1 torr) by Nd:Yag Laser was studied. the plasma spectra were analyzed by comparing the atomic lines of Al and Mg lines with standard lines. The effect of laser energies on spectral lines produced by laser ablation were investigated using optical
spectroscopy .several plasma characteristics like electron temperature, electron density, Debye’s length, plasma frequency and number of particles in the ‘‘Debye’s Sphere’’ were calculated in vacuum .The results show the electron temperature and electron density increase in magnesium, aluminum and magnesium :aluminum alloy
targets . It was found that the lines intensities at

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Publication Date
Thu Apr 27 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Numerical Solutions Of The Nonlocal Problems For The Diffusion Partial Differential Equations
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    In this work, we use the explicit and the implicit finite-difference methods to solve the nonlocal problem that consists of the diffusion equations together with nonlocal conditions. The nonlocal conditions for these partial differential equations are approximated by using the composite trapezoidal rule, the composite Simpson's 1/3 and 3/8 rules. Also, some numerical examples are presented to show the efficiency of these methods.

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Publication Date
Wed Dec 13 2017
Journal Name
Al-khwarizmi Engineering Journal
Shot Peening Time Effect on Corrosion Behaviors of Al Alloy 2024-T3
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In this study many specimen s were prepared from 2024-T3 Aluminum alloy for corrosion test by the dimensions of (15*15*3) mm according to ASTM G71-31 and then subjected to shot peening process at different time (15, 30, 45) minutes using steel ball having a diameter of 2.75 mm and Rockwell Hardness of 55RC to induce compressive residual stress which were measured using X-Ray diffraction method, surface roughness and   hardness were tested before and after peening. Electrochemical corrosion test by Tafel extrapolation method was carried out in an environment of 3 .5% NaCl solutions (sea water) where Corrosion rate calculated using Tafle equation.

The obtained results show a favorable influence of SP treatment

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Publication Date
Fri Nov 02 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Validity of Testicular Biopsy Among Azoospermic Patients Prior to Intracytoplasmic Sperm Injection
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Objective: To evaluate the clinical significance of open diagnostic testicular biopsy as prognostic predictor of
successful sperm retrieval among azoospermic infertile patients.
Design: Prospective study.
Setting: Infertility clinic and assisted reproduction unit at the institute of embryo research and infertility
treatment, Baghdad University.
Patients: Sixty infertile azoospermic patients.
Intervention: Pieces of testicular tissue taking during open diagnostic multiple bilateral testicular biopsies was
prepared for histological examination and grouped according to well-defined histopathological patterns.
Measurement of testicular size and serum reproductive hormones (FSH, LH, Testosterone, and PRL) were done

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Publication Date
Thu Jan 11 2024
Journal Name
Research Square
Exploring the Potential of Terrestrial Isopoda, Porcellionides cingendus, for Assessing Environmental Sustainability
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Abstract<p><bold>Introduction:</bold> Environmental sustainability is crucial for maintaining diverse and productive biological systems. Terrestrial isopods, such as Porcellionides cingendus, are known for their environmentally friendly characteristics and adaptability. This study explores the potential of <italic>P. cingendus</italic> in improving environmental sustainability. <bold>Methods:</bold> Samples of P. cingendus were collected from various locations and reared in controlled environments. Waste consumption efficiency was evaluated by measuring the consumption of various cellulosic wastes over 15 days. Statistical analysis was performed using One-Way ANOVA. <jat></jat></p> ... Show More
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Publication Date
Tue Mar 14 2023
Journal Name
Iraqi Journal Of Science
Antagonistic activity of Spirogyra micropunctata against some multidrug resistant human pathogenic bacteria
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The aim of present study is to investigate the antagonistic activity of Spirogyra micropunctata against multidrug resistant human pathogens. The test organisms include 3 Gram negative bacteria such as Echerichia coli, Klebsiella pneumoniae, Salmonella typhi and 2 Gram positive bacteria such as Staphylococcus aureus and Staphylococcus epidermidis. The algal cell mass was extracted in 90% Methanol and 90% Ethanol and further concentrations of 0.5, 1, 3, 5, 10, 20 mg/ml were made for each extract. Antagonistic effect was tested by using agar well-diffusion method. Methanolic crude extract showed strong antibacterial activity against all tested bacteria, while ethanolic crude extract showed moderate activity. These findings suggest the possi

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