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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
Thu Mar 31 2022
Journal Name
Journal Of The College Of Education For Women
The Logical Pragmatics of Arguments in Argumentation
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Logic is understood so far as a product perspective, either formal or informal. The topic is still, though interesting, imprecise, sketchy and problematic. Besides, the relevance of logic to linguistics has not been explained. This research focuses on dealing with logic as a product and a process. It introduces how logic is relevant to understanding language. Logic is surely not irrelevant to real human language. In this research, we coin 'logical pragmatics' to refer to "the structure of an argumentation and its parts used by the speaker for the purpose of persuasion to have an effect in the addressee and passive audience”. As such, the research mainly aims at providing a definition of "logical pragmatics" as well as developing an ide

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Publication Date
Sat Jun 01 2002
Journal Name
Alustath Journal For Human And Social Sciences
The development of Islamic periodicals in Iraq
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Islamic periodicals are defined as: publications issued periodically, and containing articles, research, or studies that convey Islamic thought and culture. Islamic periodicals have a prominent place among other types of sources of documentary and non-documentary Islamic information, because they are characterized by the speed of their issuance and the modernity and diversity of their Islamic information. This study aims to explain the reality of Islamic periodicals published in Iraq, graphically analyze their bibliographic characteristics and emphasize the importance of their issuance, as well as give a historical overview of the issuance and publication of Islamic periodicals in the Arab world and the world, while presenting examples of I

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Publication Date
Mon Jul 01 2013
Journal Name
Ceramics International
Characterization of alumino-silicate glass/kaolinite composite
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Publication Date
Thu Nov 01 2018
Journal Name
Molecular Catalysis
Hydrodesulfurization of Thiophene over $γ$-Mo2N catalyst
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Catalytic removal of the S-content from thiophene is a central step in efforts aiming to reduce the environmental burdens of transportation fuels. In this contribution, we investigate the hydrodesulfurization (HDS) mechanisms of thiophene (C4H4S) over γ-Mo2N catalyst by means of density functional theory (DFT) calculations. The thiophene molecule preferentially adsorbs in a flat mode over 3-fold fcc nitrogen hollow sites. The HDS mechanism may potentially proceed either unimolecularly (direct desulfurization) or via H-assisted reactions (hydrogenation). Due to a sizable activation barrier required for the first Csingle bondS bond scission of 54.6 kcal/mol, we predict that the direct desulfurization to contribute rather very insignificant

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Publication Date
Sun Nov 04 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Effect of Iodine Overdose on Thyroid Hyperplasia
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Objectives: study the relation between the effect of time (long time duration) with high concentration of iodine
and study its effect on the activity of the thyroid gland (hormonal and histological changes).
Methodology: An experimental study was done on (30) albino rats (8 weeks of age) to know the effect of high
concentration of iodine on the activity of the thyroid gland (hormonal and histological changes) related with
time. The study last for six months for the period of 1/2/2007 to 31/7/2007, the experiment was carried out in the
research lab. of pathology department, College of Medicine, University of Baghdad.
Results: The study shows changes in hormonal levels of thyroid hormones (T3 & T4) and also histologic

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Publication Date
Wed Mar 10 2021
Journal Name
Baghdad Science Journal
Fuzzy Subspaces For Fuzzy space of Orderings
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The purpose of this paper is to define fuzzy subspaces for fuzzy space of orderings and we prove some results about this definition in which it leads to a lot of new results on fuzzy space of orderings. Also we define the sum and product over such spaces such that: If f = < a1,…,an > and g = < b1,…bm>, their sum and product are f + g = < a1…,an, b1, …, bm> and f × g =. for all a1,…,an,b1,…,bm ? G

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Publication Date
Thu Sep 15 2022
Journal Name
Journal Of Baghdad College Of Dentistry
Different Methods of Canine Retraction- Part 1
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Background: This review aimed at explaining different methods of canine retraction along the archwire. Methods: Searching for different methods of canine retraction using fixed orthodontic appliances was carried out using different databases, including PubMed Central, Science Direct, Wiley Online Library, the Cochrane Library, Textbooks, Google Scholar, Research Gate, and hand searching from 1930 till February 2022. Results: After excluding the duplicate articles, papers describing the methods of canine retraction along the archwires were included. The most commonly used methods are NiTi closed coil spring and elastic chain. Conclusions: Various methods of canine retraction along the archwires were explained in detail regarding their adv

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Publication Date
Sun Dec 30 2001
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Isolation Behavior of Metal Modified Novolac Resin
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Publication Date
Sun Apr 26 2020
Journal Name
Iraqi Journal Of Agricultural Sciences
PALYNOLOGICAL STUDY OF GENUS Pterocephalus IN IRAQ
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This research was aimed to study the pollen morphology for the genus Pterocephalus(Vaill)  from Dipsacaceae family in Iraq, and to utilize these feathers in isolating the species as valuable taxonomic traits for enriching Iraqi flora. The study included characteristics of the type, shape, size, sculpturing and apertures, as well as determining the full dimensions using light microscopy as well as numerical analysis of this species and draw polygonal shapes and denderogram  convergence between species. The results of the study of pollen and polygonal forms showed significant differences in the characteristics at the level of each species, which helps to identification the genus species, as it was found that the pollen was a tricolp

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Publication Date
Wed Mar 30 2022
Journal Name
Journal Of Educational And Psychological Researches
Measuring the Historical Concepts of Kindergarten Children
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Historical concepts are among the concepts that are difficult to present to the pre-school child except by using modern techniques, as well as the difficulty of making visits to all historical monuments and going back to antiquity and the lack of studies in this area, therefore, we need an attractive medium that children love which is able to convey some abstract concepts that are difficult to teach to children using traditional methods, and among these activities that the kindergarten provides to children are the stories through which they develop their linguistic wealth, consolidate their religious and spiritual inclinations, refine their correct morals, and form their proper attitudes, knowledge and life concepts.

The

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