Based on Lyapunov exponent criterion, the aircraft lateral-directional stability during critical flight cases is presented. A periodic motion or limit cycle oscillation isdisplayed. A candidate mechanism for the wing rock limit cycle is the inertia coupling between an unstable lateral-directional (Dutch roll) mode with stable longitudinal (short period) mode. The coupling mechanism is provided by the nonlinear interaction of motion related terms in the complete set equations of motion. To analyze the state variables of the system, the complete set of nonlinear equations of motion at different high angles of attack are solved. A novel analysis including the variation of roll angle as a function of angle of attack is proposed. Furthermore the variation of Lyapunov exponent parameter as function of time is introduced. The numerical result indicated that the system became lightly damped at high angle of attack with increasing the amplitude of aircraft state variables limit cycle. A good agreement between the numerical result and published work is obtained for the onset of limit cycle oscillation, almost at .
The tunnel’s stability during construction is a very important matter. Some methods have been proposed for stability evaluation, but the hazard warning levels (HWLs) are more applicable among these methods. Despite monitoring and applying HWLs, several collapses in Shibli twin tunnels in Iran have cast doubts on the accuracy of this criterion in the presence of water. In this study, the critical strains under different water contents were measured through uniaxial compressive strength tests on 11 different shale and marl samples. A comparison of laboratory tests and numerical results shows that the influence of the moisture content on the critical strain is negligible. In addition, the results show that there is no dir
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Citric acid is an essential ingredient for the manufacture of (12) key industrial chemicals. Citric acid use is increasing steadily with a high annual growth rate as a result of the development of ever more sophisticated applications. Citric acid is widely utilized in the food and pharmaceutical industries due to its low toxicity when compared to other acidulous. Other uses for citric acid can be found in cleaning supplies and detergents. Based on information from a review of the literature, Citric acid production substrates and methods for surface fermentation, submerged fermentation, solid-state fermentation, and international market expansion are all covered in the current review study. Finally, there is still much to learn about the
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The research aims to know the effectiveness of a training program based on multiple intelligence theory in developing literary thinking among students of the Arabic Language Department at Ibn Rushd School of Humanities and to achieve the goal of research, the Safaris Research Institute, and the research community of Arabic language students in the Faculty of Education the third section of Arabic Language: The research sample consists of (71) students. Divided into (35) students in the experimental group and (36) students in the control group, the researcher balanced between the two groups with variables (intelligence, testing of tribal literary thinking, and time age in months), and after using the T-test for two independent samples, the
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This research addressed the cultural factors that are affecting the communicator in international public relations in light of the theory of the cultural relativism. The research aimed to find out the nature of cultural differences between societies and how can for professionals in international public relations understanding the culture of other and communicate with him peacefully. The researcher used qualitative and interpretative methodology. Some of the important results of the research are: The Communities are affected by cultural factors that are composed from values, customs, traditions, prevailing and inherited ethic, languages, religious beliefs, fashion, gender, colors indi |
In this paper a prey-predator-scavenger food web model is proposed and studied. It is assumed that the model considered the effect of harvesting and all the species are infected by some toxicants released by some other species. The stability analysis of all possible equilibrium points is discussed. The persistence conditions of the system are established. The occurrence of local bifurcation around the equilibrium points is investigated. Numerical simulation is used and the obtained solution curves are drawn to illustrate the results of the model. Finally, the nonexistence of periodic dynamics is discussed analytically as well as numerically.
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أشارت الجهود المعرفية السابقة إلى وجود اهتمام متزايد بالجماعات (Groups) على أساس أنها اللبنات الأساسية لقيام المنظمات. وقد فرض تعدد المنظمات في المجتمعات المعاصرة وتباينها من حيث أهدافها وطبيعة نشاطها، تجزئة فعالياتها إلى تخصصات عدة على وفق إطار تقسيم العمل، وبما أدى إلى تقسيم الأفراد العاملين إلى جماعات مختلفة في أدائها وأحجامها وشكلها، والتي تعمل جميعها لتحقيق هدف&
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Atherosclerosis is the most common causes of vascular diseases and it is associated with a restriction in the lumen of blood vessels. So; the study of blood flow in arteries is very important to understand the relation between hemodynamic characteristics of blood flow and the occurrence of atherosclerosis.
looking for the physical factors and correlations that explain the phenomena of existence the atherosclerosis disease in the proximal site of LAD artery in some people rather than others is achieved in this study by analysis data from coronary angiography as well as estimating the blood velocity from coronary angiography scans without having a required data on velocity by using some mathematical equations and physical laws. Fif
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تتميز هذه الورقة بتناولها موضوعاً يخشى الكثيرون الخوض فيه للملابسات الدائرة حوله، وهو اصحاب المصالح كموضوع مهم في الفكر الستراتيجي. فخاضت في مفاهيمه العامة وتصنيفاته ومنظوراته، ووجدت في مفهومه بأنهم اولئك الذين يمكن تمثيلهم بالمجاميع او الوحدات المستقلة التي ترتبط بمنظمة الاعمال عبر شبكة علاقات مؤثرة مختلفة الابعاد والاتجاهات، واذا ما حدث أي خلل في توازن هذه العلاقات، قد ت
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