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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
Wed Feb 16 2022
Journal Name
Iraqi Journal Of Science
Collision Avoidance Using Cat Swarm Algorithm for Multi Mobile Robot Path Planning in Dynamic Environment
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In this paper, we proposed a hybrid control methodology using improved artificial potential field with modify cat swarm algorithm to path planning of decoupled multi-mobile robot in dynamic environment. The proposed method consists of two phase: in the first phase, Artificial Potential Field method (APF) is used to generate path for each one of robots and avoided static obstacles in environment, and improved this method to solve the local minimum problem by using A* algorithm with B-Spline curve while in the second phase, modify Cat Swarm Algorithm (CSA) is used to control collision that occurs among robots or between robot with movable obstacles by using two behaviour modes: seek mode and track mode. Experimental results show that the p

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Publication Date
Tue Jun 01 2021
Journal Name
Baghdad Science Journal
Ammonia Removal in Free-Surface Constructed Wetlands Employing Synthetic Floating Islands: Employing synthetic floating islands
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Free water surface constructed wetlands (FSCWs) can be used to complement conventional waste water treatment but removal efficiencies are often limited by a high ratio of water volume to biofilm surface area (i.e. high water depth). Floating treatment wetlands (FTWs) consist of floating matrices which can enhance the surface area available for the development of fixed microbial biofilms and provide a platform for plant growth (which can remove pollutants by uptake).  In this study the potential of FTWs for ammoniacal nitrogen (AN) removal was evaluated using experimental mesocosms operated under steady-state flow conditions with ten different treatments (two water depths, two levels of FTW mat coverage, two different plant densities and

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Publication Date
Sat Feb 08 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Correlation between crevicular C-reactive protein level with its serum level in chronic periodontitis patients
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Background: The main purpose of this study is to find if there is any correlation between the level of C-reactive protein (CRP) in gingival crevicular fluid with its serum level in chronic periodontitis patients and to explore the differences between them according to the probing depth. Materials and methods: Forty seven male subjects enrolled in this study. Thirty males with chronic periodontitis considered as study group whom further subdivided according to probing depth into subgroup 1 with pocket depth ≤6mm, subgroup 2 with pocket depth >6mm. The other 17 subjects considered as controls. For all subjects, clinical examination where done for periodontal parameters plaque index (PLI), gingival index (GI), bleeding on probing (BOP),

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Publication Date
Tue Jun 15 2021
Journal Name
Al-academy
Sustainability by recycling palm waste in designing women's belts: وفاء حسن شافعي -مرام زيد الحربي
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This research contributes to environmental sustainability by recycling natural waste resources in making clothing products. The research aims to employ palm trees waste in designing belts suitable for contemporary women's fashion trends. Both descriptive and applied research approaches were used. Therefore, a collection of belts was designed and implemented. Then, a questionnaire was used to assess the extent to which the implemented belts achieved in sustainability standards using Likert scale. The sample size was 60 women. The data were analyzed using the SPSS program to calculate the arithmetic mean and standard deviation. One of the significant results of the research is the high average scores of the criteria for achieving sustainab

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Publication Date
Sun Jun 27 2021
Journal Name
Journal Of The College Of Education For Women
Persuasive Strategies in WHO COVID-19 Virtual Press Conferences: فراس مجيت حماد , جمعة قادر حسين
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Persuasion is an indispensable skill in everyday life; that is why, it has aroused researchers’ interest. This study aims to investigate the most frequently used persuasive strategies in texting WHO COVID-19 Virtual Press Conferences and explore how these strategies are employed to achieve persuasive messages.To this end, a text of WHO COVID-19 Virtual Press Conferences has been chosen randomly to be analyzed based on Dillard and Shen’s (2013) “Persuasive strategies in Health Campaigns”. A qualitative method has been adopted in analyzing the selected data to investigate the credibility and validity of the persuasive strategies used in such a domain. Findings have shown that most of the persuasive appeals based on the adopted mode

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Publication Date
Wed Jul 31 2019
Journal Name
Journal Of Engineering
Enhancing Heat Transfer in Tube Heat Exchanger by Inserting Discrete Twisting Tapes with Different Positions
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Enhancement of heat transfer in the tube heat exchanger is studied experimentally by using discrete twisted tapes. Three different positions were selected for inserting turbulators along tube section (horizontal position by α= 00, inclined position by α= 45 0 and vertical position by α= 900). The space between turbulators was fixed by distributing 5 pieces of these turbulators with pitch ratio    PR = (0.44). Also, the factor of constant heat flux was applied as a boundary condition around the tube test section for all experiments of this investigation, while the flow rates were selected as a variable factor (Reynolds number values vary from 5000 to 15000). The results s

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Publication Date
Sun Dec 01 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Using stress tests to manage credit concentration risks: An applied research in Sumer Commercial Bank
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The research aims to identify banking stress tests, which is one of the modern and important tools in managing banking risks by applying the equations of that tool to the sample. The banking sector considered one of the most vulnerable to sudden and rapid changes in an unstable economic environment, making it more vulnerable. Therefore, it is necessary to establish a special risk management section to reduce the banking risks of the banking business that negatively affect its performance.

The research concluded that there is a direct relationship between stress tests and risk management, as stress tests are an essential tool in risk management. They also considered a unified approach in managing bank risks that helps the bank to

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Publication Date
Wed Aug 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Proposed Measure for Effect Size in Mediation Analysis with Solution to Some Mediation Process Problems
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In this paper, the effect size measures was discussed, which are useful in many estimation processes for direct effect and its relation with indirect and total effects. In addition, an algorithm to calculate the suggested measure of effect size was suggested that represent the ratio of direct effect to the effect of the estimated parameter using the Regression equation of the dependent variable on the mediator variable without using the independent variable in the model. Where this an algorithm clear the possibility to use this regression equation in Mediation Analysis, where usually used the Mediator and independent variable together when the dependent variable regresses on them. Also this an algorithm to show how effect of the

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Publication Date
Mon Jun 01 2015
Journal Name
Journal Of Engineering
Structural Systems for Modern Architecture in Iraq Analysis Study to Dr. Qahtan Al-Madfa’i’s Architecture
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Dr. Qahtan Al-Madfa’i’s architecture has been characterized by a particular characteristic that may be unique and extreme at the same time, that is the use of the distinctive three-dimensional structural coverings and the exploitation of structural construction to give an extra aesthetic touch to the composition of the building, to achieve the application of his universal ideas, which he strongly believed and defended.

      In the period of the marked urban decline that the country undergoes now, which urges us toward making a comparison between the beginning of the modern Iraqi architecture and its ascending path up to its peak and the periods of its decline until it reached a very

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Publication Date
Sat Aug 17 2013
Journal Name
American Journal Of Pharmacological Sciences
Pentoxifylline as Adjuvant Therapy to Etanercept in Patients with Moderately to Highly Active Rheumatoid Arthritis
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