A linear and nonlinear theoretical and experimental aeroelastic investigation of a wing-flap-tab typical section model undergoing two-dimensional incompressible airflow is described. The linear flutter velocity (LFV) and frequency are predicted using linear analysis. Then a freeplay structural nonlinearity is considered in the tab. The structural equations of motion have been coupled with Theodorsen aerodynamic theory to produce the theoretical aeroelastic model which is analyzed by a state space method to predict the LFV and flutter frequency. Linear piecewise function has been used to introduce the tab spring stiffness in the freeplay state. The ground vibration test is used to measure the model structural dynamic characteristics. Then the experimental aeroelastic model is placed in a low speed wind tunnel to measure the LFV and the limit cycle oscillation (LCO) of the physical model induced by freeplay. The root main square amplitude value of the pitch, flap pitch, tab pitch and plunge degrees of freedom of the tab nonlinearities are normalized with freeplay gap size to produce a bifurcation diagram with normalized airflow velocity as the bifurcation parameter. The results show that the LCO frequency jumps from low to high frequency at a yet higher flow velocity. At the same flow velocity, the pitch and plunge motion response amplitudes drop while the flap pitch and tab pitch degrees of freedom response amplitude increase. In general the experimental measured LCO is more complicated than the theoretically calculated LCO in terms of the harmonic content of the response. On the other hand there is good agreement between the theoretical and experimental result of the linear system as well the LCO for the tab freeplay nonlinearities
This study aimed to find relationship between thymidine kinase-1 (TK-1) as tumor marker and total antioxidant capacity (TAC) in Iraqi children patients with thrombocytopenia and with thrombocytosis. The present study conducted 60 children patients (30 patients with idiopathic thrombocytopenia purpura (ITP) and 30 patients with thrombocytosis caused by leukemia) attending the Children Fever Hospital in the Medical City / Baghdad, and 30 healthy children as a control group. All study groups were with range ages (1-15) years, and they were diagnosed by assay of platelet count, Prothrombin Time (PT), and partial Thromboplastin Time (PTT). The results shown elevation in plasma TK-1 and TAC values in children patients with thrombocytopenia and w
... Show MoreBackground: Fetal macrosomia is usually distressing to obstetricians and neonatologists. In the current study, involved mothers had poor social and medical circumstances, as they were migrated forcefully within the country borders due to war, from their original homeland to safer camps which had miserable situations. Objectives: To study rate, risk factors, and complications of macrosomia in people with low socio-economic living conditions and missed medical follow up. Methods: All internally displaced pregnant women who gave birth to neonates weighed ≥4000 g were involved in the study. All required history, examination, care, and investigations were practiced by the attending obstetrician and neonatologist. Cases of normal birth weight n
... Show MoreT-cell activation and alteration of cytokine levels are involved in the pathogenesis of asthma. However, the profile of circulating T-lymphocyte subsets and related cytokines during asthmatic attacks is still unclear. We compared the serum concentrations of proinflammatory cytokines Interleukine-18( IL-18) and Interleukine-12(IL-12), T-helper 2 (Th2) cytokine Interleukine-13(IL-13 ) and Immunoglobuline-E ( IgE) in 27 asthmatic children and 21 sex and age matched healthy control subjects. Serum cytokines and IgE concentrations were measured by enzyme-linked immunosorbent assay. Serum IL-13 , IL-18 and IgE concentrations were significantly higher in asthmatic patients than normal control subjects ( IL-13: median 9.73 versus 4.43 pg/ml, P&l
... Show MoreAim: To learn more about Oral Lichen Planus Iraqi patients, including their background information, symptoms, and prognosis. Materials and Methods: From the Oral and Maxillofacial Pathology Department, College of Dentistry, Baghdad University, we retrospectively reviewed the medical records of 68 patients with a histologically confirmed clinical diagnosis of oral lichen planus and subsequently contacted the patients by phone to evaluate their prognosis. Results: Females were more likely than males to experience severe pain; the reticular form of Oral Lichen Planus was the most prevalent at 38.2%, but the erosive type was more prevalent among females. Only 53 of 68 patients responded to phone calls. More than 37% of those respondents reporte
... Show MoreA finite element is a study that is capable of predicting crack initiation and simulating crack propagation of human bone. The material model is implemented in MATLAB finite element package, which allows extension to any geometry and any load configuration. The fracture mechanics parameters for transverse and longitudinal crack propagation in human bone are analyzed. A fracture toughness as well as stress and strain contour are generated and thoroughly evaluated. Discussion is given on how this knowledge needs to be extended to allow prediction of whole bone fracture from external loading to aid the design of protective systems.
The aim of this study is to utilize the behavior of a mathematical model consisting of three-species with Lotka Volterra functional response with incorporating of fear and hunting cooperation factors with both juvenile and adult predators. The existence of equilibrium points of the system was discussed the conditions with variables. The behavior of model referred by local stability in nearness of any an equilibrium point and the conditions for the method of approximating the solution has been studied locally. We define a suitable Lyapunov function that covers every element of the nonlinear system and illustrate that it works. The effect of the death factor was observed in some periods, leading to non-stability. To confirm the theore
... Show MoreThe present study aimed to investigate the histological changes of heart, lung, liver and kidney which caused by different concentrations (10, 20 and 40 mg/kg) of Ivabradine. Results of the study revealed some histological changes represented by aggregation of the lymphocytes around respiratory bronchioles of the lung. In the liver, the drug caused hepatocyte necrosis and infiltration of the lymphocytes. In Kidney, there are no histopathological modifications in the tissue after the animals treated with 10 mg\kg of Ivabradine. When the animals treated with Ivabradine drug at 20mg/kg of bw, dose showed vascular congestion between myocardial fibers of heart. Emphysematous c
... Show More(Sepak takraw) is a game that mixes football and volleyball, it is played on a court similar to a badminton court, in which players have the right to play the ball with any part of the body except the arm and hand. The object of the game is to return the ball to the opponent's court and score a point. Since it is a newly emerging game, all aspects related to it must be studied and covered in order to reach the highest levels, and it is known that each game or sporting activity has its own physical and motor capabilities, which is important to determine the level of technical performance, as the game's abilities contribute to mastering the skills. The importance of research in determining standard levels of physical and motor abilities for y
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