The paper presents an investigation to the flutter speed of composite wing for different ply orientation. Structurally the composite wing was idealized as a composite beam load carrying structure. Theodorsen’s expression was used to get the 2- dimension unsteady lifting force and pitching moment in the limit of incompressible flow and subsonic speed which were integrated over the wing span. A free vibration analysis was first carried out to get the natural frequencies and mode shapes .The velocity-damping (V-g) method was used to calculate the flutter speed and the flutter frequency. A wing of unmanned aerial vehicle was manufactured from woven glass and polyester resin where the flutter speed was calculated experimentally by the wind tunnel test .The flutter speed was calculated analytically for different ply orientation, it is found that the increasing in torsion rigidity leads to increase in the flutter speed, the fiber combination with high torsion rigidity and relatively low coupling rigidity give higher flutter speed.
In this paper, compared eight methods for generating the initial value and the impact of these methods to estimate the parameter of a autoregressive model, as was the use of three of the most popular methods to estimate the model and the most commonly used by researchers MLL method, Barg method and the least squares method and that using the method of simulation model first order autoregressive through the design of a number of simulation experiments and the different sizes of the samples.
The study was conducted at research station A, department of field crops, college of agricultural engineering sciences, university of Baghdad during summer 2021 to evaluate the effect of boron and some growth regulators on some growth criteria and yield of soybean crop (cv. shimaa). The experiment was carried out according to split plots by using randomized complete block design with three replications. The main plots included three concentrations of boron (75, 150 and 225) mg.L-1, the sub-plots included three levels of growth regulators, spraying kinetin (100 mg. L-1), spraying ethrel (200 mg.L-1) and spraying kinetin (100 mg.L-1) + spraying ethrel (200 mg.L-1) as
... Show MoreIn order to improve the students’ performance level in some of the skills that are implemented on the mat device of ground movements, including the front and rear rolling, it is necessary to study the most important indicators that have a clear impact on the performance of those rolls. Among the objectives of the research: To identify the percentage of the contribution of flexibility of the hip joint, the angle of the knees and the muscular strength of the arms in the performance of the front and rear rolling skills, an opening of the research sample. The researchers used the descriptive method in the survey method for its suitability to the nature of the work, and the research community was represented by students of the third st
... Show MoreThis study was carried out to investigate the effects of magnetized water on accumulated infiltration depth. A test rig was designed and constructed for this purpose was installed at the water tests laboratory of the Department of Water Resources Engineering at the University of aghdad. The investigation was carried out by using two types of soil, different flow velocities throughout magnetizing device and different configuration of magnets over and under the water passage of the magnetizing device. The soils that were used in the experiments are clayey and sandy soils. Six different flow velocities throughout magnetizing device ranged between 0.29 to 1.19 cm/s and ten configurations of arranging the magnets over and under th
... Show MoreLactobacillus Plantarum and Lactobacillus rhamnosus GG were encapsulated using 3% of alginate via extrusion technique. And the probiotics capsules produced were further coated used 1% chitosan to increase the survival of probiotics, and evaluation of The heat resistance of the slow pasteurization and fast pasteurization for Lb,pla and Lb.GG for control and bacteria coated one layer and bacteria coated two layer at 63°C/ 30 minutes and 72°C/ 15 seconds. The results indicate that the Probiotic coated two layer are more resistant to pasteurization temperatures at 63°C/ 30 minutes and 72°C/ 15 seconds than the Probiotic coated one layer. While the results of the control follow a significant reduction for viability of cell toward pasteuri
... Show MoreIs the subject of the mind took a dimension in philosophy and psychology , and has cared psychologists this topic to a large extent , I started education institutions interest in the capabilities of intelligence since the early twentieth century , and the development of interest in them until he arrived to find Standards and Criteria to identify the degree IQ of any individual , and began to educational institutions interested in mental talent and talented .
The United States is the country chock first of these research projects , but they devoted all their attention on the wish talent mental and Gifted , until I got to the projects, the so-called time ( ( wars of the mind ) ) and projects Schools gifted
... Show MoreThe study aims to verify the independence of auditors working in companies and offices of the Iraqi audit, and measure the level of accounting conservatism in the financial statements of banks and insurance companies listed on the Iraq Stock Exchange, as well as a statement after the independence of the auditor on accounting conservatism in the financial statements of banks and insurance companies listed on the market Iraq Stock Exchange, as it has been measuring the independence of the auditor using the survey form was auditors working in the Iraqi audit firms were measured the level of accounting conservatism for companies sample using a form( Basu) was a statement after variables through the use of statistical models in a mann
... Show MoreThe article presents the results of studies of the species composition of phytopathogens of winter soft wheat grain affected by ear fusarium. For the first time, studies were conducted using a complex of electron microscopic, molecular genetics, and mycological methods. The species F. graminearum dominated in all samples (frequency of occurrence 42.8%). The species F. avenaceum (23.3%), F. sporotrichioides and F. equiseti (8.8% each) were noted with high frequency. Next in descending order of frequency of occurrence: F. oxysporum, F. boothii, F. poae, F. proliferatum, F. accumatum, F. incarnatum, F. vorosii, F. tricinctum, F. cerealis, F. sambuticum. For the first time, 7 species were found for the plain zone of the Pre-Caucasus: F.
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