The aerodynamic and elastic forces may cause an oscillation of the structure such as the high frequency of the airfoil surfaces and the dynamic instability occurring in an aircraft in flight and failure may occur at a speed called flutter speed. In this work, analytical and numerical investigations of flutter limits of thin plates have been carried out. The flutter speed of rectangular plates were obtained and compared with some published results. Different design parameters were investigated such as aspect ratio, thickness and their effects on flutter velocity. It was found that the structural mode shape plays an important role in the determination of the flutter speed and the coupling between the bending and torsional mode is the main cause of flutter.
מחקר זה בוחן את התפתחות הדימוי של ערבים בספרות הישראלית דרך עבודותיהם של אלי עמיר ודורית רביניאן שני סופרים חשובים שסיפוריהם מאתגרים סטריאוטיפים שוררים ומרחיבים את ההבנה התרבותית הניתוח הממוקם במסגרת הספרות המזרחית עוקב אחר האופן שבו דמויות ערביות עוברות מדמויות שוליים לאנשים מורכבים ומעודנים המשקפים שינויים סוציו פוליטיים רחבים יותר על ידי השוואת חקר הזהות והעקירה של עמיר בסביבה היהודית בבגדד לבין
An efficient modification and a novel technique combining the homotopy concept with Adomian decomposition method (ADM) to obtain an accurate analytical solution for Riccati matrix delay differential equation (RMDDE) is introduced in this paper . Both methods are very efficient and effective. The whole integral part of ADM is used instead of the integral part of homotopy technique. The major feature in current technique gives us a large convergence region of iterative approximate solutions .The results acquired by this technique give better approximations for a larger region as well as previously. Finally, the results conducted via suggesting an efficient and easy technique, and may be addressed to other non-linear problems.
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Abstract
The study aims to know the degree of secondary school managers' practice of servant leadership in Gaza from their teachers’ perspective. It further aims to examine whether there are any statistically significant differences at (α 0.05≥) between the means of the study sample’s members attributed to variables such as (gender, educational qualification, and years of experience). To achieve the objectives of the study, the study adopted the descriptive survey method, using a questionnaire consisting of (30) items distributed to four domains: (workers service, ethical dealing, motivation & influence, and building an organized, integrated society). Then, the questionnaire was distributed to t
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This study is an approach to assign the land area of Kirkuk city [ a city located in the northern of Iraq, 236 kilometers north of Baghdad and 83 kilometers south of Erbil [ Climatic atlas of Iraq, 1941-1970 ] into different multi zones by using Satellite image and Arc Map10.3, zones of different traffic noise pollutions. Land zonings process like what achieved in this paper will help and of it’s of a high interest point for the future of Kirkuk city especially urban
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The objectives of this research are to determine and find out the reality of crops structure of greenhouses in association of Al-Watan in order to stand on the optimal use of economic resources available for the purpose of reaching a crop structure optimization of the farm that achieves maximize profit and gross and net farm incomes , using the method of linear programming to choose the farm optimal plan with the highest net income , as well as identifying production plans farm efficient with (income - deviation) optimal (E-A) of the Association and derived, which takes into account the margin risk wich derived from each plan using the model( MOTAD), as a model of models of linear programming alternative programming m
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يُعدّ الوجود احد أعمق المواضيع التي تناولها الفلاسفة على مرّ العصور، إذ يشتمل على تساؤلات حول الحياة والموت وغاية الوجود والحرية الإنسانية، وغيرها من التساؤلات التي نشأت مع نشوء الانسان. وقد لعب الفلاسفة، قديمهم وحديثهم، دورًا أساسيًا في إرساء دعائم الفكر الوجودي المعاصر؛ إلا أننا, مع ذلك, لا نستطيع إنكار دور الدين في التأثير على الفكر الفلسفي الوجودي بشكل عام. وقد انعكست أفكار الوجودية الفلسفية المعاصرة في
... Show MoreThis paper reports a numerical study of flow behaviors and natural convection heat transfer characteristics in an inclined open-ended square cavity filled with air. The cavity is formed by adiabatic top and bottom walls and partially heated vertical wall facing the opening. Governing equations in vorticity-stream function form are discretized via finite-difference method and are solved numerically by iterative successive under relaxation (SUR) technique. A computer program to solve mathematical model has been developed and written as a code for MATLAB software. Results in the form of streamlines, isotherms, and average Nusselt number, are obtained for a wide range of Rayleigh numbers 103-106 with Prandtl number 0.71
... Show MoreAbstract: Recently, there is increasing interest in using mode-division multipelexing (MDM) technique to enhace data rate transmission over multimode fibers. In this technique, each fiber mode is treated as a separate optical carrier to transfer its own data. This paper presents a broadband, compact, and low loss three-mode (de)multiplexer designed for C+L band using subwavelength grating (SWG) technology and built-in silicon-on-insulator SOI platform. SWG offers refractive index engineering for wider operating bandwidth and compact devices compared to conventional ones. The designed (de)multiplex deals with three modes (TE0, TE1, and TE2) and has a loss > -1 dB and crosstalk < −15 dB, and its operation c
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