A two-dimensional computational study had been performed regarding aerodynamic forces and pressures affecting a cambered inverted airfoil, CLARK-Y smoothed with ground effects by solving the Reynolds-averaged Navier-Stokes equations, using the commercial software COMSOL Multiphysics 5.0 solver. Turbulence effects are modeled using the Menter shear-stress transport (SST) two-equation model. The negative lift (down-force), drag forces and pressures surface were predicted through the simulation of wings over inverted wings in different parameters namely; varying incidences i.e. angles of attack of the airfoils, varying the ride hide from the ground covering various force regions, two-dimensional cross-section of the inverted front wings to be fixed on nose of a race car- and varying speeds of initial airflow (Reynolds number). The results show that the down-force increases as the angle of attack increases; however, if an inverted wing is fixed on a car at high angles of attack the wing starts to stall which is not a desired condition that affects the vehicle stability and performance. As the ride height was reduced, the down-force was increased; at clearances between the suction surface and the ground of less than 0.2 of the chord length c, the down-force is significantly higher. Very close to the ground, at a ride height of less than 0.1c, down-force decreases as the wing stalls. Also, down-force increases as the free-stream velocity (Reynolds number) increases. The pressures for lower and upper surface of the wing increased with increasing both of angle of attack and ride height, but remains relatively ineffective with varying the speeds.
The Mediating Role of Cobit 2019 in Managing the Relationship Between Qualitative Characteristics of Accounting Information and Information Asymmetry
The chemical bath deposition technique (CBD) is considered the cheapest and easiest compared with other deposition techniques. However, it is highly sensitive to effective parameter deposition values such as pH, temperature, and so on. The pH value of the reaction solution has a direct impact on both the nucleation and growth rate of the film. Consequently, this study presents a novel investigation into the effect of a precise change. in the pH reaction solution value on the structural, morphological, and photoresponse characteristics of tin monosulphide (SnS) films. The films were grown on a flexible polyester substrate with pH values of 7.1, 7.4, and 7.7. The X-ray diffraction patterns of the grown films at pH 7.1 and 7.4 confirmed
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The aim of the current research is to extract the psychometric properties of Philip Carter's tests (for mental agility) according to the classical measurement theory. To achieve these goals, the researcher took a number of scientific steps to analyze Philip Carter's tests (for mental agility) according to the classical measurement theory. The researcher translated Philip Carter's (mental agility) tests from English into Arabic and then he translated them conversely. For the purpose of statistical analysis of paragraphs of the Philip Carter tests (mental agility) to extract the psychometric properties, the tests were applied to a sample of (1000) male and female students who were selected by cluster sampl
... Show MoreThe international financial accounting and reporting standards IFRS/IAS represent the set of rules and foundations that the economic entity must follow in the measurement, presentation, and disclosure of the elements of the financial statements, the implementation of adopting the international financial reporting standards contributes to improving the qualitative characteristics of accounting information, so the current research aims to explain the role of adopting the International Accounting Standard (IAS) in improving the qualitative characteristics as well as analyzing the impact of the adoption of IAS.1 in improving the qualitative characteristics of accounting information within the financi
... Show MoreA field experiment was conducted in the growth season 2019-2020 at the botanical garden of the Biology Department at the College of Education for Pure Sciences/Ibn Al-Haitham, University of Baghdad-Iraq. The experiments’ purpose is to determine the effects of different melatonin concentrations on some morphological and physiological characteristics of mung (Vigna radiata L.) plant under the influence of three periods of drought (5, 10, 15 days). The results were showed that the increasing of water stress periods had significant effects in the reducing rates of the studied characteristics, especially at the period 15 days. The external treatment of different concentrations of melatonin reduced the drought effects and that’s led to signif
... Show MoreBackground: Mycoplasma pneumoniae (M. pneumoniae) is an important respiratory bacterial pathogen, especially among children. It causes acute upper and lower respiratory infections.Objective: This study was aimed to measure anti- M. pneumoniae antibodies among hospitalized children who were admitted to hospital diagnosed with acute respiratory tract infections.Method: Automated ELISA technique was performed to detect anti- M. pneumoniae antibodies (IgM and IgG antibodies) in serum from 108 children less than 5 years old. The children were admitted to the Pediatric Teaching Hospital in Suleimani city/Kurdistan Region/Iraq because of acute respiratory tract infections. A questionnaire was designed to collect demographic and clinical data fr
... Show MoreA field experiment was conducted during the autumn of 2021 at the Agricultural Research Department station / Abu Ghraib to evaluate the soil moisture, water potential distribution, and growth factors of maize crops under alternating and constant partial drip irrigation methods. In the experiment, two irrigation systems were used, surface drip irrigation (DI) and subsurface irrigation (SD); under each irrigation system, five irrigation methods were: conventional irrigation (CI), and 75 and 50% of the amount of water of CI of each of the alternating partial irrigation APRI75 and APRI50 and the constant partial irrigation FPRI75 and FPRI50 respectively. The results showed that the water depth for conventional irrigation (C1) was 658.3
... Show MoreAbstract The present work aims to study the performance of reinforced compacted clay soil by sand columns stabilized with sodium silicate to obtain more solid columns than the surrounding soil. The experimental work was carried out by using a lab model to evaluate the performance of both the floating and end bearing sand columns. The results showed that the improvement ratio for the soil reinforced with sand columns stabilized with sodium silicate reached 390% for the type of floating columns and 438% for end bearing columns.