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AN EXPERIMENTAL STUDY OF THE EFFECT OF VORTEX GENERATOR ON THE FLAT-PLATE BOUNDARY LAYER: AN EXPERIMENTAL STUDY OF THE EFFECT OF VORTEX GENERATOR ON THE FLAT-PLATE BOUNDARY LAYER
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This paper is dealing with an experimental study to show the influence of the geometric characteristics of the vortex generators VG son the thickness of the boundary layer (∂) and drag coefficients (CD) of the flat plate. Vortex generators work effectively on medium and high angles of attack, since they are "hidden" under the boundary layer and practically ineffective at low angles.

            The height of VGs relative to the thickness of the boundary layer enables us to study the efficacy of VGs in delaying boundary layer separation. The distance between two VGs also has an effect on the boundary layer if we take into account the interference between two pairs of VGs. The effect of the changing in (h- the height of vortex generator, d- the average distance between tow vortex generators) on the thickness of the flat plate boundary layer and the drag coefficients has been studied for triangular vortex generator. The measurements of the vortex generator have been changed to determine the optimum boundary layer thickness and the change in drag coefficients. An experiment was done at an average free stream velocity, (U,) of 28 m/s. The experiment was conducted in the wind tunnel UTAD-2 University (NAU) Kiev, Ukraine.

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Publication Date
Sun Dec 04 2011
Journal Name
Baghdad Science Journal
Dopping Effect on Optical Constant of Poly (Vinyl Chloride)
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Thick films of poly(vinyl chloride)(PVC)& PVC doped with Zn(etx)2 salt complex have been prepared by cast method with fixed thickness almost (120±5) Microns. Optical studies were carried out in the wavelengths region(200-900)nm based on absorption & transmition measurement. Optical parameters such as absorption coefficient(?) ,refraction index(n) and extinction coefficient(K) were observed to be effected by adding the dopant.Electrical parameters such as real(?)& imaginary(?) part of dielectric constant were also calculated part of dielectric constant were also calculated from the optical parameters using Maxwell equation.

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Publication Date
Mon Jun 01 2020
Journal Name
Iop Conference Series: Materials Science And Engineering
Effect of Adding Sand on Clayey Soil Shear Strength
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Abstract<p>The effect of adding sand on clayey soil shear strength is investigated in this study. Five different percentage of clay-sand mixtures are used; 100% clay with 0% sand termed 100C, 60% clay with 40% sand termed 60C-40S, 30% clay with 70% sand termed 30C-70S, 15% clay with 85% sand termed 15C-85S, and as well as 100% sand termed 100S. The used clay was obtained from Baghdad city in Iraq and classified as CH soil, while the used sand was taken from Al-Khider area from Iraq and classified as SW soil. The initial dry unit weight for all mixtures is 16 kN/m<sup>3</sup>. The results show that the variations of the soil shear strength properties with soil components content changes</p> ... Show More
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Publication Date
Thu Jun 01 2023
Journal Name
Effect Of Dna Damage Mediating Psychosocial Stress On Aging
Effect of DNA damage mediating psychosocial stress on aging
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Adversity and psychosocial stress are involved in aging through the following pathways. psychological stress enhances the nerve system to secrete endocrine mediators (hormones). Mitochondrial respiration mediates energy production stimulated by binding to these hormones to their receptors. Energy produced by mitochondria accelerates metabolism and, in its turn, leads to increases in reactive oxygen species (ROS) of free radicals. Cellular stress and accumulation of damage can result from an excess of ROS. Accumulation of damage comprises damages in telomeric and nontelomeric DNA, in addition to mitochondrial DNA. Mitochondrial DNA damage plays an important role in increasing the pathway of p53/p21. The expression of the PGC-1α gene is inhi

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Publication Date
Mon Jun 26 2017
Journal Name
Journal Of Contemporary Medical Sciences
Antimicrobial effect of probiotic Lactobacillus spp. on Pseudomonas aeruginosa
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Publication Date
Tue May 16 2023
Journal Name
Journal Of Engineering
Investigation of Backfill Compaction Effect on Buried Concrete Pipes
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The present study deals with the experimental investigation of buried concrete pipes. Concrete pipes are buried in loose and dense conditions of gravelly sand soil and subjected to different surface loadings to study the effects of the backfill compaction on the pipe. The experimental investigation was accomplished using full-scale precast unreinforced concrete pipes with 300 mm internal diameter tested in a laboratory soil box test facility set up for this study. Two loading platforms are used namely, uniform loading platform and patch loading platform. The wheel load was simulated through patch loading platform which have dimensions of 254 mm *508 mm, which is used by AASHTO to model the wheel load of a HS20 truck. The pipe-soil system

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Publication Date
Sat Jun 01 2019
Journal Name
Geoderma
Effect of cover crop management on soil hydraulic properties
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Publication Date
Tue Jan 06 2026
Journal Name
Frontiers In Mechanical Engineering
Effect of different wing geometries on their vibration characteristics
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Understanding how wing geometry and internal structural configuration influence vibration behavior is essential for ensuring the aeroelastic stability and structural integrity of modern aircraft. This study presents a comprehensive numerical investigation of the modal and deflection characteristics of aircraft wings with different geometries (symmetric tapered planform and swept-back) and spar configurations (box and I-section) using the finite element method (FEM) in ANSYS Mechanical APDL R.15. Six NACA airfoil profiles (0024, 2411, 2416, 2424, 4412, and 4421) with angle of attack 9° under 50 m/s speed and 1,100 kg pay load were analyzed under identical aerodynamic and material conditions using linear elasti

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Publication Date
Wed Mar 30 2022
Journal Name
Journal Of Educational And Psychological Researches
Analyzing the content of the two science books (the two chemistry units) for the intermediate stage according to environmental problems
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    The main goal of the current research is to know -Environmental problems included in the content of the two science books (chemistry units) for intermediate stage

A list of environmental problems had been prepared  and  consisting of (8) main areas which are (air and atmosphere pollution, water pollution, soil pollution, energy, disturbance of biodiversity and environmental balance, waste management, food and medicinal pollution, investment of mineral wealth). Of which (60) sub-problems,  at that time the researcher analyzed the two science books (two chemistry units) for the intermediate stage of the academic year (2020-2021) in light of the list that was prepared, and the validity and consisten

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Publication Date
Tue Sep 28 2021
Journal Name
Journal Of The College Of Education For Women
Lying in Arthur Miller's The Crucible: A Pragmatic Study: هديل محمود إبراهيم , جمعه قادر حسين
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Lying is a controversial issue as it is closely related to one's intended meaning to achieve certain pragmatic functions. The use of lying in literary works is closely related to the characters’ pragmatic functions as in the case of Miller's The Crucible where it is used as a deceptive complex phenomenon that cannot be observed out of context. That is, the use of lying as a deceptive phenomenon represents a violation to Grices's Maxims. Thus, the study aims to qualitatively examine the kinds of maxims being violated, the kinds of violations conducted, the strategies followed in the violations, and the pragmatic functions behind such violations across the different categories of lies. To this end, the (30) extracts fou

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Publication Date
Sun Dec 27 2020
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The role of International Monetary Fund in Planning monetary policy for Developing the Iraqi economy: An Applied Research for the Period (2004-2013)
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The developing countries, like our country Iraq suffer from deep comprehensive structural crisis, manifestations and a clear imbalance between the demand and the supply sides. The overall imbalance in the external balance. As a consequence, this caused the accumulation of foreign debts or failure in the implementation of economic development programs. The countries which are forced to resort to the International Monitoring Funds, and the World Bank for assistance and to express an opinion on policies that include restrictions controls that belong to the monetary, and fiscal side group, imposed on the economies crisis, as a condition for returning to normal which called reform programs. The organize of the events of radical changes in the

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