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Numerical Investigation of Aerodynamic Characteristics of Supercritical RAE2822 Airfoil with Gurney Flap
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Gurney flap (GF) is well-known as one of the most attractive plain flaps because of the simple configuration and effectiveness in improving the lift of the airfoil. Many studies were conducted, but the effects of GF on the various airfoil types need to be further investigated. This study aimed to clarify the effect of GF in the case of the supercritical airfoil RAE2822. This research includes a steady, two-dimensional computational investigation carried out on the supercritical airfoil type RAE-2822 to analyze Gurney flap (GF) effects on the aerodynamic characteristics of this type of airfoil utilizing the Spalart-Allmaras turbulence model within the commercial software Fluent. The airfoil with the Gurney flap was analyzed for three different height values 1%c, 2%c, and 3%c, and five mounting angles (30°,45°,60°,75°, and 90°) with the axial chord for angles of attack (-1°,-2°,-3°,0°,1°,2°,3°). The calculations showed that when GF height is increased, the maximum suction pressure on the upper surface increases by 25.4%, 36.5%, and 68.83% when the height of the Gurney flap is 1%c, 2%c, and 3%c, respectively, compared with that on the airfoil without GF. The lift coefficient was also increased, and the shock waves moved downward by increasing GF height. As Gurney flap heights increase, the drag coefficient increases gradually for positive angles of attack but for negative angles of attack. The drag coefficient also decreases with increasing the GF heights. As long as the angle of the mounting is between 45o and 90o, the lift coefficient does not differ on a large scale. For mounting angles less than 45o, the lift coefficient drops quite fast. As a result, reducing the Gurney flap’s lift enhancement and the drag coefficient increases gradually for positive angles of attack, but for negative angles, it can be noted that the drag coefficient decreases with increasing the mounting angles of GF. The calculated values of the lift and drag coefficients with an attack angle and pressure coefficient compared with the experimental values, and a good agreement was noticed. 

 

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Publication Date
Sat Jul 18 2020
Journal Name
College Of Islamic Sciences
Soort of Hamid al-Taie and his sons in the poetry of Abu Tammam and Al-Bohtari
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The phenomenon of celebration of army leaders in the Abbasid era formed a distinct phenomenon at which the poets stood, and among those leaders was the Arab leader Hamid al-Taie, and the poets who stood on him and his sons Abu Tammam and al-Bohtari recorded in their poems the exploits of that leader, and the exploits of his sons through images that represented sadness, courage In this research, the generosity, and the rhetorical and artistic aspects of those images, have been spotted, balancing the poets.

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Publication Date
Wed Aug 30 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
The Use of Some Inorganic Additives to Retard Combustion and Flammabitity of Unsaturated Polyester and Epoxy Resins
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In  this  work,  three  inorganic  additives were 1,1sed,  these  are  (I)  ;

tetraethyl ammonium bromodichloro phenylphsphin, (II) Chlorinated paraffine. and (ITI) a mixture  of  (50%  by weight  of each) to study the synergetic effect.  These  additives \'v·cre used  as flame retardants with unsaturated  polyester  and  epoxy  resins.;, since  these  resins  are industrially important  and of \Vide uses in life.

Results showed efficiency of these  additives to retard  fl mmabillty and stop burning of resins throqght the ASTM tests used Measurement of Limiting oxygen  index (LOI), &nbs

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Publication Date
Fri Jan 19 2024
Journal Name
Research Journal Of Pharmacy And Technology
Cutoff Point Measurement of the waist circumference for the diagnosis of Metabolic Syndrome in Iraqi university students
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Background: Metabolic syndrome (MetS) is a collection of connected cardiovascular risk factors that characterizes the complicated illness. The waist circumference cutoff point fluctuation has so far defined Mets. Objective: This study aimed to determine the cutoff point for WC in healthy Iraqi adults. Methods: This cross-sectional survey establishes the standard value for WC among 300 healthy university students in Wasit city, Iraq. They are aged between 18-25 years. The receiver operator characteristic (ROC) curve was used WC to predict the presence of two or more risk factors for MetS, as defined by IDF. Results: The cutoff level yielding maximum sensitivity and specificity for predicting the presence of multiple risk factors was

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Publication Date
Tue Nov 09 2021
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Relationship between accounting Conservatism, Persistence and volatility of earnings of companies listed on the Iraq Stock Exchange
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The study aimed to show the concept and importance of accounting Conservatism, Persistence and volatility of earnings of companies listed in the Iraqi market for securities have been selected 35 companies for the period between 2013 to 2107 used the scale of book value to market value to measure the Conservatism while the current profit regression model was used to measure future profits Eviews 9 was used for the purpose of testing the two hypotheses. The results of the study found that there is a statistically significant relationship between accounting Conservatism and Persistence of earnings. The relationship is inverse with no statistically significant relationship between Conservatism and earnings volatility.

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Publication Date
Sun Jan 20 2019
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Study Influence of Substrate Temperature on Optical Properties of CdS Thin Films Prepared by Chemical Spray pyrolysis
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This study aims to prepare Cadmium Sulphide (CdS) thin films using thermal Chemical Spray Pyrolysis (CSP) on glass of different temperatures substrate from cadmium nitrate solution. Constant thickness was (430 ± 20 nm) and the effect of substrate temperature on the optical properties of prepared thin films.

Optical properties have been studied from transmittance and absorbance spectral within wavelengths range (360 - 900 nm). The results show that all the prepared films have a direct electron transitions and optical energy gap between (2.31-2.44 eV). They also show that the transmittance and optical energy gap of films prepared from nitrate solution increase with increasing of substrate temperature, then transmittance start do

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Publication Date
Sun Mar 30 2008
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
A Quantitative Analysis of the Mixing of Three Solids Different in Density by an Air Fluidized Bed
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Three cohesionless free flowing materials of different density were mixed in an air fluidized bed to study the mixing process by calculating performance of mixing index according to Rose equation (1959) and to study the effect of four variables (air velocity, mixing time, particle size of trace component and concentration of trace component) on the mixing index and as well as on mixing performance. It was found that mixing index increases with increasing the air velocity, mixing time and concentration of trace component until the optimum value. Mixing index depends on the magnitude of difference in particle size The first set of experiments (salt then sand then cast iron) give higher mixing index and better performance of mixing than the

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Publication Date
Sat Mar 18 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
A Description of A New Species of Leafhopper Genus Assuita Lindberg; 1969 (Hemoptera: Cicadellidae: Agalliinae) From Iraq
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The present study introduces description of a new species of leafhopper of genus Assuita Lindberg; 1969. This study includes external morphological characters and the spotting patterns and photos of vertex face pronotum, mesonotum, fore wing, hind wing and the shape of male abdominal abodeme, also aedeagus, connective, genital style and genital plate.

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Publication Date
Tue Jun 30 2015
Journal Name
Al-kindy College Medical Journal
A study of the effect of smoking on pulmonary function tests in AL - Kindy teaching hospital, Baghdad
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ABSTRACTBackground: In Iraq smoking is a common habit in both the urban and rural areas. There are many respiratory diseases like chronic bronchitis, bronchial carcinoma and emphysema which are related to chronic tobacco smoking.Objectives: To study the effect of tobacco smoking on the respiratory system, to establish a correlation between chronic tobacco smoking and its effects on the parameters which were studied and to create awareness in tobacco smokers about the effects of tobacco on their healthMethod: In this study 100 male subjects, 50 chronic smokers and 50 non- smokers were assessed for their pulmonary function tests by using a computerized spirometer.Results: Almost all their respiratory parameters were significantly reduced.

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Publication Date
Thu Oct 19 2023
Journal Name
Journal Of Optics
Production and characterization of porous silicon via laser-assisted etching as photodetector: effect of different HF concentrations
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Publication Date
Fri Jan 01 2021
Journal Name
Chemical Science
Stalling chromophore synthesis of the fluorescent protein Venus reveals the molecular basis of the final oxidation step
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Fluorescent proteins (FPs) have revolutionised the life sciences, but the chromophore maturation mechanism is still not fully understood. Here we photochemically trap maturation at a crucial stage and structurally characterise the intermediate.

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