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alkej-529
The Effects of Vortex Generator Types on Heat Transfer and Flow Structure in a Rectangular Duct Flows
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    In this numerical study a detailed evaluation of the heat transfer characteristics and flow structure in a laminar and turbulent flow through a rectangular channel containing built-in of different type vortex generator has been a accomplished in a range of Reynolds number between 500 and 100,000.A modified version of ESCEAT code has been used to solve Navier-Stokes and energy equations. The purpose of this paper is to present numerical comparisons in terms of temperature, Nusselt number and flow patterns on several configurations of longitudinal vortex generator including new five cases. The structures of heat and flow were studied, using iso-contours of velocity components, vortices, temperature and Nusselt number. This study shows that the predicted structures of fluid flow, temperature fields and Nusselt number variation are strongly affected by the presence of the turbulators. Staggered arrangement gains high Nusselt number, also the lower and upper arrangements have higher Nusselt number than plane duct. High Reynolds number (higher air inlet velocity) will enhance the Nusselt number. Increase in ribs height will enhance the heat transfer as it works as surface area and turbulator at the same time. 

 

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Publication Date
Tue Jun 30 2009
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
The Effect of Extraction Temperature and Solvent to Oil Ratio on Viscosity Index of Mixed-medium Lubricating Oil Fraction by Using Solvents Extraction
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In this study two types of extraction solvents were used to extract the undesirable polyaromatics, the first solvent was furfural which was used today in the Iraqi refineries and the second was NMP (N-methyl-2-pyrrolidone).
The studied effecting variables of extraction are extraction temperature ranged from 70 to 110°C and solvent to oil ratio in the range from 1:1 to 4:1.
The results of this investigation show that the viscosity index of mixed-medium lubricating oil fraction increases with increasing extraction temperature and reaches 107.82 for NMP extraction at extraction temperature 110°C and solvent to oil ratio 4:1, while the viscosity index reaches to 101 for furfural extraction at the same extraction temperature and same

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Publication Date
Fri Jun 30 2023
Journal Name
Biomedicin
Antibacterial action of AgNPs produced from different isolates Gram positive and Gram-negative bacteria on biofilm of Klebsiella pneumoniae isolated from the RTI
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Silver nanoparticles synthesized by different species

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Publication Date
Wed Dec 01 2021
Journal Name
Iraqi Journal Of Physics
Effect of Zinc (Zn) -Doped on the Structural, Optical and Electrical Properties of (Cdo)1-Xznx Films Prepared by Pulsed Laser Deposition Technique
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Pure cadmium oxide films (CdO) and doped with zinc were prepared at different atomic ratios using a pulsed laser deposition technique using an ND-YAG laser from the targets of the pressed powder capsules. X-ray diffraction measurements showed a cubic-shaped of CdO structure. Another phase appeared, especially in high percentages of zinc, corresponding to the hexagonal structure of zinc. The degree of crystallinity, as well as the crystal size, increased with the increase of the zinc ratio for the used targets. The atomic force microscopy measurements showed that increasing the dopant percentage leads to an increase in the size of the nanoparticles, the particle size distribution was irregular and wide, in addition, to increase the surfac

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Publication Date
Sun Dec 07 2014
Journal Name
Baghdad Science Journal
Adsorption of some Metal Ions from Aqueous Solution on Iraqi Rice Bran and Its Relation to the Physical Properties of these Metal Ions
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Adsorption studies were carried out to test the ability of the Iraqi rice bran (Amber type) to adsorb some metals divalent cations (Cd2+, Co2+, Cu2+, Fe2+, Ni2+, Pb2+, and Zn2+) as an alternative tool to remove these pollutants from water. The Concentrations of these ions in water were measured using flame and flamless atomic absorption spectrophotometry techniques. The applicability of the adsorption isotherm on Langmuir or Freundlisch equation were tested and found to be dependent on the type of ions. The results showed different adsorptive behavior and different capacities of the adsorption of the ions on the surface of the bran. The correlation between the amounts adsorbed and different cation parameters including (electronegativity, io

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Publication Date
Mon Feb 22 2021
Journal Name
Educatum Journal Of Science, Mathematics And Technology
Effect of ammonia/gallium ratio and growth temperature towards the surface morphology of semi-polar GaN grown on m-plane sapphire via MOCVD
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A single-crystalline semi-polar gallium nitride (11-22) was grown on m-plane (10-10) sapphire substrate by metal organic chemical vapor deposition. Three-step approach was introduced to investigate the grain size evolution for semi-polar (11-22) GaN. Such approach was achieved due to the optimized gallium to ammonia ratio and temperature variations, which led to high quality (11-22) oriented gallium nitride epilayers. The full width at half maximum values along (-1-123) and (1-100) planes for the overgrowth temperature of 1080°C were found to be as low as 0.37° and 0.49°, respectively. This was an indication of the enhanced coalescence and reduction in root mean square roughness as seen by atomic force microscopy. Surface analysi

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Publication Date
Sun Feb 10 2019
Journal Name
Journal Of The College Of Education For Women
Morphological Views of Al-Seraphy in the matter of "altasqeer" (reduction)
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This paper addresses some of the morphological views of Al-Seraphy in the matter of "altasqeer" (reduction) in his book, "shareh ketab Sibawayh" (the explanation of Sibawayh's book) linking between them (views of Al-Seraphy) and the data of the morphological theme, in ancient times, and recently. Through balancing between what we have learned from the views of Al-Seraphy and the views of other former linguists and grammarians and latecomers of him. In this research we have linguistically and idiomatically explained the definition of "altasqeer" (reduction), and it's standard morphological balancing and what has deviated from it, by the examples in both cases; then we has produced the views of the grammarians of that "the definition of "a

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Publication Date
Thu Jul 03 2025
Journal Name
Journal Of Baghdad College Of Dentistry
An Oral Health Status and Treatment Needed in Relation to Dental Knowledge, Among a Group of Children Attending Preventive Department, College of Dentistry, University of Baghdad
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Background: Oral health represents an important base for human well-being; the heath of the body begins from oral cavity. Great deal has been applied to increase knowledge in the field of oral health in order to develop appropriate preventive program. This study was conducted in order to estimate the percentage and severity of dental caries and gingivitis among children attending Preventive Department in Collage of Dentistry, University of Baghdad and to determine dental treatment need for those patients, further more to study the relation of these variables with dental knowledge. Materials and Methods: The study group consists of 163 children with an age ranged from 6 to 14 years, who attended the preventive clinic for the first time to be

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Publication Date
Sun Dec 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
The impact of brand identity in achieving marketing objectives Applied Study in the International Company for smart card "Key Card"
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Each organization has values ​​and objectives, tangible and intangible properties of its products. The reflection of properties on the brand constitutes the identity of the brand that contributes to building the customer's convictions about the products or services provided by any organization and its brand in a positive or negative way. This is reflected in purchasing behavior, which may push forward the progress towards marketing goals or deviation from them. Therefore, the current research came to identify the brand identity, its types and the factors affecting them and how they affect to achieve each of the marketing goals. At a time when

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Publication Date
Sun Jan 22 2023
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The impact of international Accounting Standard No (21) in reducing tax obstacles : applied research in the General Authority for Taxes .
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               The research aimed to shed light on the impact of international Accounting Standard No (21) on tax obstacles represented by (tax evasion, double taxation) The financial statements of a group of banks operating in the private sector were relied upon to know the impact of the standard on tax obstacles, as well as knowing the amount of amounts, The researcher relied on the method of financial analysis of that data, which was obtained from the website of the Securities Commission, and conducted personal interviews with a number of university professors, chartered accountants, financial experts, banks, and the General Authority for Taxes to benefit from their

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Publication Date
Wed Apr 13 2022
Journal Name
International Journal Of Medical Sciences
Evaluation of the Levels of Erythropoietin and Some Haehematological Parameters in Patients with History of Haemodialysis and Non- haemodialysis
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