In this paper, a numerical model for fluid-structure interaction (FSI) analysis is developed for investigating the aeroelastic response of a single wind turbine blade. The Blade Element Momentum (BEM) theory was adopted to calculate the aerodynamic forces considering the effects of wind shear and tower shadow. The wind turbine blade was modeled as a rotating cantilever beam discretized using Finite Element Method (FEM) to analyze the deformation and vibration of the blade. The aeroelastic response of the blade was obtained by coupling these aerodynamic and structural models using a coupled BEM-FEM program written in MATLAB. The governing FSI equations of motion are iteratively calculated at each time step, through exchanging data between the structure and fluid by using a Newmark’s implicit time integration scheme. The results obtained from this paper show that the proposed modeling can be used for a quick assessment of the wind turbine blades taking the fluid-structure interaction into account. This modeling can also be a useful tool for the analysis of airplane propeller blades.
A newly derivative of oxazolidin-5- one namely [2-(2-biphenyl-4-yl-imidazo [1,2-a] pyridine-3-yl)-3-(4-nitro-phenyl)-oxazolidin-5-one (BIPNO5)] was examined as an corrosion inhibitor for carbon steel surface. Quantum mechanical method of Density Functional Theory (DFT) with (B3LYP (6-311++G (2d, 2p)) level of theory was used to calculate the minimize structure, physical properties and inhibition chemical parameters, in vacuum and two solvents (DMSO and H2O), all at equilibrium geometry. The results indicated that the new derivative could adsorb on the surface of carbon steel through the heteroatom, showing that the new inhibitor has good corrosion inhibition performance.
A mathematical method with a new algorithm with the aid of Matlab language is proposed to compute the linear equivalence (or the recursion length) of the pseudo-random key-stream periodic sequences using Fourier transform. The proposed method enables the computation of the linear equivalence to determine the degree of the complexity of any binary or real periodic sequences produced from linear or nonlinear key-stream generators. The procedure can be used with comparatively greater computational ease and efficiency. The results of this algorithm are compared with Berlekamp-Massey (BM) method and good results are obtained where the results of the Fourier transform are more accurate than those of (BM) method for computing the linear equivalenc
... Show Moreواقع العلاقات التركية الالمانية والبحث عن نموذج للاستقرار
After the outbreak of COVID-19, immediately it converted from epidemic to pandemic. Radiologic images of CT and X-ray have been widely used to detect COVID-19 disease through observing infrahilar opacity in the lungs. Deep learning has gained popularity in diagnosing many health diseases including COVID-19 and its rapid spreading necessitates the adoption of deep learning in identifying COVID-19 cases. In this study, a deep learning model, based on some principles has been proposed for automatic detection of COVID-19 from X-ray images. The SimpNet architecture has been adopted in our study and trained with X-ray images. The model was evaluated on both binary (COVID-19 and No-findings) classification and multi-class (COVID-19, No-findings
... Show MoreDNA, as the basis of every living cell, is one of the most important and influential scientific discoveries. This research aims to identify and compare the organizational DNA to the leadership practices of school principals in the Sultanate of Oman and to reveal the similarity between principals’ leadership practices and the structure of DNA. In addition, it intends to identify any statistically significant differences between the responses of the participants due to the study variables: gender, job title and experience. A questionnaire was designed and data were collected from a randomly selected sample composed of (100) teachers in the Sultanate of Oman. The study found limitless diversity in the characteristics of DNA of leadership
... Show MoreThe present study was done to identify the karyotype of Mystus pelusius fish , which is the only representative of the family Bagridae in Iraq, they have been caught from Tigris river in AL-Kraat area of Baghdad city, the results show that the diploid chromosome number was 2n=32 and the males chromosomal types included 2n=(6m+13sm+7st+6t)and fundamental number FN=51, in females chromosomal types included 2n=(6m+12sm+8st+6t)with FN=50,also it observed that the first submetacentric pair was the largest within the biarmed chromosomes .The results revealed that the male heterogamety and the female homogamety , accordingly it follows the sex determination system (XX / XY) , as the (X) chromosome represented by medium sized submetacentr
... Show MoreThe Morphological description and histological structure of olfactory organ in barn owl have been studied. The results of morphological description showed that the olfactory organ in the animal under study have pair of external nares ovale shape which lead to pair of nasal chambers which are located at the dorsal surface of head under eyes level. The chambers are conical in their shape the anterior end is narrow while the posterior end is enlarger the nasal chambers open to the oral cavity through the internal nares. The results also showed that the nasal cavity contains three chonchae which represented by rosteral chonchae, elongated middle chonchae and the posterior nasal chonchae called olfac
... Show MoreThis study showed that liver of Passer domesticus bilobed the right lobe is cardiac shape while the left is elliptical and the liver colour is brown. It is occupying most of anterior and middle parts of abdominal cavity. The liver is surrounded by Glison capsule which is represented by a thin layer of connective tissue with septum extend peripherally in liver tissue. The liver tissue is formed from polyhedral hepatocyte arrange as irregular hepatic cord surrounded the central vein. Each cell contains one or two nucleus with one or more nucleolus. The blood sinusoid appeared between the liver cells .The hepatic cord arranged radially around the central vein. The portal area is clear and surrounded by connective tissue. Gallbladder is almost
... Show MoreThe current study was designed to investigate the histological structure of the cerebellum in the Iraqi frog
The term ‘photometry’ refers to the accurate determination of the apparent brightness of an astronomical object. Until roughly 1980, nearly all astronomical photometry was done by means of analog measurements of photographic plates, or by analog or digital (photon-counting) techniques with photomultipliers. These photometers produced brightness readings which were typically displayed on dials, plotted on strip charts or printed on strips of paper, and it was often quite practical to analyse these raw data with pencil, paper and a slide rule or table of logarithms. However, during the late 1970s electronic area detectors for astronomy became more advanced: first, for a brief period, television-type cameras were employed, but these were s
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