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The Effects of Inclination and Compounds Angles of Round Holes in Staggered Rows on Adiabatic Film Cooling Effectiveness of Vane Suction side
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The aim of this work is oriented to increase film cooling effectiveness value through numerical investigations for flow of Mach number not more than 0.3 around vane surface, to find the effects of inclination and compounds angles of round holes in staggered rows on adiabatic film cooling effectiveness of vane suction side. Multi cylindrical film cooling hole cases were studied with pitch ratio P/d =2 and 3, local blowing ratios M=0.382, 0.77 and 1.14,  inclination angles a=30° and 45°, compound angles β= 0°, 15°, 30° and 45° and local momentum ratios I= 0.084, 0.34 and 0.756  for better cooling process.

            A numerical technique, using ANSYS-FLUENT version 14.5, was used to solve governing partial differential equations of mass, momentum (Navier Stokes equations) and energy conservations in three dimensions with a  turbulence model that involves the solution of the four transport equations. Based on the results of the numerical solution, the best film cooling configuration, blowing ratio, with the range of actual engine flow conditions, dimensions and vane geometry; density ratio 1.74 , temperature ratio 0.57 and blowing ratio M=0.382, 0.77 and 1.14 was obtained. The best case for inclination angle a=30°, P/d=2 was at M=1.14 and β=0° for the total average effectiveness along 60L/d of surface suction side was 0.616, while the best case for inclination angle a=45°, P/d=2 was at M=0.382 and β=30° for the total average effectiveness along 60L/d of surface suction side was 0.516.

            In addition, comparisons were performed with available other work, where the experimental total average effectiveness results of Dees et al., 2011 were in good agreements with the numerical results of current work with a maximum deviation of 9.9% at I=0.34 and 3.6% at I=0.75.

 

 

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Publication Date
Mon Mar 01 2021
Journal Name
Iraqi Journal Of Physics
Studying the Correlation Between Supermassive Black Holes and Star Formation Rate for Samples of Seyfert Galaxies (Type 1 and 2)
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An optical spectroscopic study is reported in this article to study the correlation between the supermassive black hole (SMBH) and the star formation rate (SFR) for a sample of Seyfert galaxies type (I and II). The study focused on 45 galaxy of Seyfert 1, in addition to 45 galaxy of Seyfert 2, where these samples have been selected form different survey of Salon Digital Sky Survey (SDSS). The redshift (z) of these objects were between (0.02 – 0.26). The results of Seyfert 1 galaxies shows that there good correlation between the SMBH and the SFR depending on statistical analysis parameter named Spearman’s Rank Correlation in a factor of (ρ=0.609), as well as the Seyfert 2 galaxies results show a good correlation between the SMBH and

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Publication Date
Tue Mar 30 2021
Journal Name
Scientific Review Engineering And Environmental Studies (srees)
Testing the performance of a solar energy cooling system in Baghdad city
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Renewable energy resources have become a promissory alternative to overcome the problems related to atmospheric pollution and limited sources of fossil fuel energy. The technologies in the field of renewable energy are used also to improve the ventilation and cooling in buildings by using the solar chimney and heat exchanger. This study addresses the design, construction and testing of a cooling system by using the above two techniques. The aim was to study the effects of weather conditions on the efficiency of this system which was installed in Baghdad for April and May 2020. The common weather in these months is hot in Baghdad. The test room of the design which has a size of 1 m3 was situated to face the geographical south. The te

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Publication Date
Mon Mar 25 2019
Journal Name
Al-academy
Iconography of Textual Thresholds in Crime Film Scenarios
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It is not new to say that recent studies have tended to look at the margins of the texts in order to extract the information provided by the book to the recipient. The margins of the texts were defined in a number of terms, including the thresholds, and the margins of the text, etc. The difference was according to the researchers who dealt with the subject in research and inquiry. Therefore, all researchers assert that the texts must provide information even if it is propaganda for the text. Hence the importance of these texts emerged as they represent a scientific information material that encapsulates the body of the text as well as being a propaganda material that inspires the reader to read it. Hence for

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Publication Date
Fri Aug 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
The impact of strategic approach in the effectiveness of small and medium Enterprises in Iraq
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The purpose of this research highlight the achievement of the effectiveness of small and medium enterprises dimensions and conformable to analyze the relationship between business strategies and human resources management strategies , and launched search of a dilemma thought provoking fundamental questions revolve around the search is the lack of appropriate strategies in these enterprises to help them continuity and permanence in business and markets , as these enterprises lack the human resources management strategies appropriate , as well as business strategies that make them withstand the changes in the market environment is changing and volatile . It was to

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Publication Date
Wed Dec 18 2019
Journal Name
Baghdad Science Journal
Effect of the Dielectric Barrier Discharge Plasma on the Optical Properties of CDS Thin Film
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Cadmium sulphide CdS films with 200 nm have been prepared by thermal evaporation technique on glass substrate at substrate room temperature under vacuum of 10-5mbar.In this paper, the effect of Dielectric Barrier Discharge plasma on the optical properties of the CdS film. The prepared films were exposed to different time intervals (0, 3, 5, 8) min. For every sample, the Absorption A, absorption coefficient α , energy gap Eg ,extinction coefficient K and dielectric constant ε were studied. It is found that the energy gap were decreased with exposure time, and absorption , Absorption coefficient, refractive index, extinction coefficient,  dielectric constant increased with time of exposure to the plasma. Our study conside

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Publication Date
Tue Feb 14 2023
Journal Name
Journal Of Educational And Psychological Researches
The Effectiveness of Teaching Practices of Science and Mathematics Teachers Based on the National Framework for Future Skills in the Omani School
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Abstract

The research aims to identify the level of effectiveness of the teaching practices of science and mathematics teachers in light of the national framework for future skills in Omani schools. To achieve the objectives of the study, the researchers used the descriptive approach, as he designed a note card consisting of (30) phrases distributed on three axes: basic skills, practical skills, and technical skills. After verifying the validity and reliability of the tools, they were applied to a sample of (116) teachers. The results of the research revealed that the level of effectiveness of the teaching practices of mathematics teachers has recorded a medium degree with a mean (3.05). The results a

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Publication Date
Sun Sep 05 2010
Journal Name
Baghdad Science Journal
The Effects of ? – Rays on The Optical Constants of ZnS Thin Films
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ZnS thin films were grown onto glass substrates by flash evaporation technique, the effects of ? – rays on the optical constants of ZnS these films were studied. It was found that ? – rays affected all the parameters under investigation.

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Crossref
Publication Date
Sat Jun 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
Freedom of movement of capital and its impact on the effectiveness of monetary policy In Iraq (2005-2016)
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The interest in the issue of capital movement as an economic phenomenon has increased because of its effects and effects and its ability to influence the economic balance and the effectiveness of monetary policy. All countries seek to attract capital and benefit from it because of its effects and results such as supporting economic development process and optimal allocation of economic resources. The problem of the financing gap that most countries suffer from, and others, but sometimes the movement of capital creates challenges for monetary policy makers in achieving their goals.

   After 2003, the Iraqi economy witnessed an openness and economic liberalization unlike previous years, which

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Crossref
Publication Date
Mon Jan 02 2017
Journal Name
Journal Of Educational And Psychological Researches
Effectiveness of fishbowl strategy on intermediate students’ achievement in geography subject
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The aim of this study is to examine the effectiveness of fishbowl strategy as one of the effective learning strategies for intermediate students’ achievement in geography subject. To do this, three classes of second intermediate were chosen from Noor Al-Mustafa School for academic years (2015-2016). (64) Student were selected as a sample that distributed into two equal groups: experimental and control group. The research used the achievement test as an instrument to come up with the finding of the study. The experiment began on Tuesday 13th of October 2015 and ended on Tuesday 5th January 2016. Through this time, the researcher taught them the first and second chapter in geography of Arab homeland using fishbowl s

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Publication Date
Thu Oct 01 2020
Journal Name
Journal Of Engineering
Electrocoagulation for Treatment of Simulated Blowdown Water Of Cooling Tower
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This study investigates the results of electrocoagulation (EC) using aluminum (Al) electrodes as anode and stainless steel (grade 316) as a cathode for removing silica, calcium, and magnesium ions from simulated cooling tower blowdown waters. The simulated water contains (50 mg/l silica, 508 mg/l calcium, and 292 mg/l magnesium). The influence of different experimental parameters, such as current density (0.5, 1, and 2 mA/cm2), initial pH(5,7, and 10), the temperature of the simulated solution(250C and 35 0C), and electrolysis time was studied. The highest removal efficiency of 80.183%, 99.21%, and 98.06% for calcium, silica, and magnesium ions, respectively, were obtained at a current de

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