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joe-1553
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
Wed May 02 2012
Journal Name
Journal Of Planner And Development
the planning and design characteristics of Iraqs mud building and settlement
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The Mesopotamian soil is muddy and fertile, and so from ancient eras Iraqis used mud in their building, settlements and architecture in different methodologies according to the nature and the function of the building that was either in its pure form or by mixing it with other materials such as straw . also as raw bricks in different ways either for the whale building or parts of it, or for the finishing parts such as roofing for instance. In this research these different forms and methodologies will permeate through out a chosen examples of historical building, rural buildings and settlements and ancient buildings as well as some current uses of mud in the structures and building in standing cities, this in order to conclude some

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Publication Date
Wed Jan 01 2020
Journal Name
Journal Of Information Hiding And Multimedia Signal Processing
Enhancement of lsb audio steganography based on carrier and message characteristics
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Data steganography is a technique used to hide data, secret message, within another data, cover carrier. It is considered as a part of information security. Audio steganography is a type of data steganography, where the secret message is hidden in audio carrier. This paper proposes an efficient audio steganography method that uses LSB technique. The proposed method enhances steganography performance by exploiting all carrier samples and balancing between hiding capacity and distortion ratio. It suggests an adaptive number of hiding bits for each audio sample depending on the secret message size, the cover carrier size, and the signal to noise ratio (SNR). Comparison results show that the proposed method outperforms state of the art methods

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Publication Date
Wed Dec 01 2021
Journal Name
Civil Engineering Journal
Evaluating the Friction Characteristics of Pavement Surface for Major Arterial Road
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The performance of the pavement in terms of vehicle safety and tire wear is affected by the friction behavior of the pavement. To highlight the main characteristics that affect the production of better friction resistance of the pavement surface in this work. The micro-texture and macro-texture of the asphalt surface of Baghdad Airport highway were studied using two methods: (sand patch method and the British pendulum test). The sand patch was examined by drawing sand grains of a specific volume, while the micro-texture was analyzed using a BPT under dry and wet surface conditions. All data obtained from the two examinations were analyzed and modelled statistically using SPSS 25 software. Results show that skid resistance of pavemen

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Publication Date
Sun Jan 01 2023
Journal Name
Iop Conference Series: Earth And Environmental Science
Sustainable communities rating system within the context of Iraqi cities characteristics
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Abstract<p>Rating systems for evaluating the sustainability of communities are an essential tool that is increasingly applied throughout the developed world to set criteria indicators to optimize the physical, social, economic, and environmental potential within such communities. Rating systems vary based on existing disparities among societies and their unique building and physical planning practices. Iraqi cities lacked the adaptation of a formal methodology or sustainability rating system to correctly measure the built environment’s sustainability indicators. This research attempts to review the most substantial rating systems to measure the sustainability of communities worldwide to form a</p> ... Show More
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Publication Date
Sat Jul 01 2017
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
EFFECT OF HONEY ON SPERM CHARACTERISTICS AND PREGNANCY RATE IN MICE
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    The aim of the current study is to demonstrate the effect of honey on the sperms characteristics (sperm concentration, sperm motility, grade of activity and sperm normal morphology) as well as pregnancy rate in mice. Sperms were obtained from caudal epididymis of male mice and prepared by adding10% of honey to the IVF medium using direct sperms activation technique for 30 minute incubation period before artificial insemination.

 

    The study revealed a significant (P > 0.05) increase in active sperm motility (grade A and grade B) 49% and pregnancy rate 53.3% in female mice artificially inseminated with sperms. On the other hand, there were no significant differences in sperm con

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Publication Date
Sat Jul 01 2023
Journal Name
Chalcogenide Letters
Investigating the optical and electrical characteristics of As60Cu40-xSex thin films
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In this work, As60Cu40-xSex thin films were synthesized, and the pulsed laser deposition method was used to study the effected partial replacement of copper with selenium. The electrical characteristics and optical characteristics, as indicated by the absorbance and transmittance as a function of wavelength were calculated. Additionally, the energy gap was computed. The electrical conductivity of the DC in the various conduction zones was calculated by measuring the current and voltage as a function of temperature. Additionally, the mathematical equations are used to compute the energy constants, electron hopping distance, tail width, pre-exponential factor, and density of the energy states in variation zones (densities of the energ

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Publication Date
Fri Dec 22 2023
Journal Name
Al-rafidain Journal Of Medical Sciences ( Issn 2789-3219 )
Clinical Characteristics and Therapeutic Management of Osteogenesis Imperfecta in Iraqi Children
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Background: Osteogenesis imperfecta (OI) is a rare congenital condition that results in bone fragility, recurrent fractures, and various extra-skeletal manifestations. Currently, intravenous bisphosphonate is the mainstay of medical treatment in OI. Objective: To identify the effect of current management strategies on Iraqi children diagnosed with OI. Methods: A retrospective study enrolled OI patients who were registered in Central Child Teaching Hospital, Baghdad, Iraq, from January 2015 to December 2022. We enrolled confirmed OI cases (either clinically and/or radiologically) who received cyclic pamidronate therapy for at least 3 cycles. They neither received other types of bisphosphonates nor underwent surgical intervention. Res

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Publication Date
Wed Jan 01 2020
Journal Name
Journal Of Information Hiding And Multimedia Signal Processing
Enhancement of lsb audio steganography based on carrier and message characteristics
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Data steganography is a technique used to hide data, secret message, within another data, cover carrier. It is considered as a part of information security. Audio steganography is a type of data steganography, where the secret message is hidden in audio carrier. This paper proposes an efficient audio steganography method that uses LSB technique. The proposed method enhances steganography performance by exploiting all carrier samples and balancing between hiding capacity and distortion ratio. It suggests an adaptive number of hiding bits for each audio sample depending on the secret message size, the cover carrier size, and the signal to noise ratio (SNR). Comparison results show that the proposed method outperforms state of the art methods

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Publication Date
Fri Jun 01 2007
Journal Name
Al-khwarizmi Engineering Journal
Investigation of heat transfer phenomena and flow behavior around electronic chip
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Computational study of three-dimensional laminar and turbulent flows around electronic chip (heat source) located on a printed circuit board are presented. Computational field involves the solution of elliptic partial differential equations for conservation of mass, momentum, energy, turbulent energy, and its dissipation rate in finite volume form. The k-ε turbulent model was used with the wall function concept near the walls to treat of turbulence effects. The SIMPLE algorithm was selected in this work. The chip is cooled by an external flow of air. The goals of this investigation are to investigate the heat transfer phenomena of electronic chip located in enclosure and how we arrive to optimum level for cooling of this chip. These par

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Publication Date
Fri Oct 16 2020
Journal Name
Solid State Technology
Study and Investigation of Transition Rate at Metal–Organic Semiconductor Interfaces
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In this paper,we focus on the investigated and studied of transition rate in metal/organic semiconductor interface due to quantum postulate and continuum transition theory. A theoretical &nbsp;model has been used to estimate &nbsp;the transition rate cross the interface through estimation many parameters such that ;transition energy &nbsp;,driving electronic energy U(eV) ,Potential barrier ,electronic coupling &nbsp;,semiconductor volume ,density ,metal work function ,electronic affinity and temperature T. The transition energy &nbsp;is critical facter of charge transfer through the interfaces of metal organic films device and itscontrol of charge injection and transport cross interface. However,the potential at interfa

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