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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
Sun Jun 30 2013
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Zinc Element Traces to Inhibit Scale Formation on Cooling Tower and Air Cooler Systems
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Calcium carbonate is predominantly present in aqueous systems, which is
commonly used in industrial processes. It has inverse solubility characteristics
resulting in the deposition of scale on heat transfer surface. This paper focuses on
developing methods for inhibition of calcium carbonate scale formation in cooling
tower and air cooler system where scaling can cause serious problems, ZnCl 2 and ZnI
2 has been investigated as scale inhibitor on AISI 316 and 304. ZnCl 2 were more
effective than ZnI 2 in both systems, and AISI 316 show more receptivity to the
chlorides salt compared to AISI 304. The inhibitors were more effective in cooling
tower than air cooler system. AISI 316 show more constant inhibition effic

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Publication Date
Mon Apr 01 2019
Journal Name
Journal Of Engineering
Two Stage Evaporative Cooling of Residential Building Using Geothermal Energy
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The weather of Iraq has longer summer season compared with other countries. The ambient temperature during this season reaches over 50 OC which makes the evaporative cooling system suitable for this climate. In present work, the two-stage evaporative cooling system is studied. The first stage is indirect evaporative cooling (IEC) represented by two heat exchangers with the groundwater flow rate (5 L/min). The second stage is direct evaporative cooling (DEC) which represents three pads with groundwater flow rates of (4.5 L/min). The experimental work was conducted in July, August, September, and October in Baghdad. Results showed that overall evaporative efficiency of the system (two coils with three pads each

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Publication Date
Sat Mar 30 2024
Journal Name
Al-qadisiyah Journal For Engineering Sciences
Investigation of an automobile air-conditioner with a liquid-suction heat exchanger using R134a and R1234yf
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Air-conditioning systems (ACs) are essential in hot and humid climates to ensure acceptable ambient air quality as well as thermal comfort for buildings users. It is essential to improve refrigeration system performance without increasing the effects of global warming potential (GWP) and ozone depletion potential (ODP). The main objective of this study is to evaluate the performance of an air conditioning system that operates with a liquid suction heat exchanger (LSHX) through implementing refrigerants with zero OPD and low GWP (i.e., R134a and R1234yf). Liquid suction heat exchanger (LSHX) was added to an automobile air conditioning system (AACS).When Liquid suction heat exchanger was added to the cycle, primary results indicated t

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Publication Date
Sat Apr 23 2022
Journal Name
Research Journal Of Pharmacy And Technology
Effect of Natural/ Synthetic Polymers and Super disintegrants on the Formulation of Zafirlukast Fast Dissolving Film
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Fast-dissolving films are one of the interested delivery systems for oral solid dosage forms to overcome swallowing difficulty for geriatric and pediatric patients. Zafirlukast (ZLK) is one of the most commonly used oral medication for treatment of asthmatic patients particularly mild to moderate cases. Oral fast dissolving films of ZLK were prepared using two different filming forming polymers, hydroxypropyl methylcellulose (HPMC) and sodium carboxymethyl cellulose (SCMC). Different concentrations of the 2 polymers were used to prepare 10 formulas. Other excipients were also added at various ratios to produce 10 different formulations. These were maltodextrin, crosspivodone, polyvinylpyrrolidone (PVP), and banana powder. In vitro c

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Publication Date
Fri Jan 01 2021
Journal Name
Aip Conference Proceedings
The effects of devitrification on the lithium glass surface and microstructure
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Publication Date
Fri Apr 01 2022
Journal Name
Chalcogenide Letters
The dependence of the energy density states on the substitution of chemical elements in the Se6Te4-xSbx thin film
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The energy density state are the powerful factor for evaluate the validity of a material in any application. This research focused on examining the electrical properties of the Se6Te4- xSbx glass semiconductor with x=1, 2 and 3, using the thermal evaporation technique. D.C electrical conductivity was used by determine the current, voltage and temperatures, where the electrical conductivity was studied as a function of temperature and the mechanical electrical conduction were determined in the different conduction regions (the extended and localized area and at the Fermi level). In addition, the density of the energy states in these regions is calculated using the mathematical equations. The constants of energy density states are det

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Publication Date
Mon Feb 18 2019
Journal Name
Iraqi Journal Of Physics
Effect of annealed temperature on some structural, optical and mechanical properties of selenium thin film
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In this paper a thin films of selenium was prepare on substrates of n-Si by evaporation in a vacuum technique with thickness about 0.5μm. And then an annealing process was done on samples at two temperature (100 and 200) C ° in a vacuum furnace (10-3 torr).
Some structural, optical and mechanical properties of prepared thin films were measured. Results showed that the prepared film was the crystallization, optical transmittance and micro hardness of the prepared thin films increased significantly after annealing.

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Publication Date
Thu Nov 08 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Effectiveness of lactation counseling on maintenance of breastfeeding
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Objective(s): To determine the effectiveness of lactation counseling on maintenance of breastfeeding after
cesarean section for study group.
Methodology: A quasi-experimental study was conducted on non probability sample (purposive) of (60) women
who had cesarean section and sample divided in to two groups (30) of them as a study group from Fatima AlZahra'a
Maternity and Pediatric Teaching Hospital & implement lactation counseling on it and another group (30)
as control group from Baghdad Teaching Hospital in Baghdad City. Study implemented for the period of April 24th
2011 to August 2nd 2011. A questionnaire was used as a tool of data collection to fulfill with objective of the study
and consisted of three parts

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Publication Date
Tue Dec 31 2019
Journal Name
Journal Of Economics And Administrative Sciences
The Causes and Effects of Earnings Management on Stock Prices
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This study uses the performance of the discretionary estimation models by using a sample of listed companies in the Netherlands and Germany. The actual accounting framework provides a wide opportunity for managers to influence data in financial reporting. The corporate reporting strategy, the way managers use their discretionary accounting, has a significant effect on the company's financial reporting. The authors contribute to the literature through enhancement to these models to accomplish better effects of identifying earnings management as well as to present evidence that is particular to the Dutch and German setting.

For this, we followed the methodology of Dechow, Sloan, and Sweeney (1995) and Chan

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Publication Date
Tue Jul 02 2019
Journal Name
Sudan Journal Of Medical Sciences
Positive and Negative Effects of the Commensal Bacteria on Carcinogenesis
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Background: Cancer is a lethal disease that results from a multifactorial process. Progression into carcinogenesis and an abnormal cell proliferation can occur due to the micro and macro environment as well as genetic mutations and modifications. In this review, cancer and the microbiota – mainly bacteria that inhabit the tumour tissue – have been discussed. The positive and negative impacts of the commensal bacteria on tumours being protective or carcinogenic agents, respectively, and their strategies have also been described. Methods: Related published articles written in English language were searched from Google Scholar, PubMed, Mendeley suggestions, as well as Google search using a combination of the keywords ‘Microbiota, commens

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