نتایج جستجو برای: linear vibration

تعداد نتایج: 529384  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه اصفهان - پژوهشکده تربیت بدنی و علوم ورزشی 1391

چکیده معضل چاقی به عنوان عارضه ای جدی برای زندگی بی تحرک و ماشینی، مورد توجه اغلب مراکز بهداشتی و درمانی دنیا قرار گرفته است. چاقی عامل زمینه ساز و در واقع عامل خطری برای بروز بیماری های قلبی - عروقی است که عموماً با کاهش طول عمر مورد انتظار و افزایش بیماری همراه است. هدف پژوهش حاضر تأثیر 12 هفته تمرینات ویبریشن کل بدن، تمرینات هوازی و تمرینات ترکیبی( هوازی و ویبریشن کل بدن) بر ترکیب بدنی زنان ...

Journal: :ماشین های کشاورزی 0
حمید قربانپور محمد هادی خوش تقاضا محمدرضا مستوفی سرکاری

manual citrus harvesting is commonly performing hard, expensive and time consuming. in this study, a factorial experiment with a completely randomized design in three replications was performed to find out the effect of frequency (three levels of 5, 7.5 and 10 hz), vibration time (three levels of 10, 15 and 20 seconds) on harvesting capacity and losses of thomson cultivar of orange. the results...

A linear superposition method was used for modeling the time history of the production blast vibrations and optimizing the blast sequence to reduce vibration levels in Sar-Cheshmeh copper mine, Kerman, Iran. A single-hole blast for modeling and two double-hole blasts with time delays of 25 and 65 ms between two holes for modeling validation were carried out. The generated vibrations were measur...

Journal: :تحقیقات موتور 0
محمد رضا قاسمی m.r. ghassemi یوسف حجت y. hojjat

today there are different vibration isolators used in industries according to the weight and excitation frequency of the machines which have vibration. one of them is air spring which is in two types: convoluted air spring and membrane air spring. convoluted air springs are used to control vibrations in low frequency (usually lower than 10 hz) and the membrane ones are used in high frequency (u...

2012
M. H. Taha

An analytical solution for nonlinear vibration of an initially stressed beam with elastic end restraints resting on a nonlinear elastic foundation is obtained. As a first step in solving nonlinear vibration equation, the linear vibration mode functions for a beam with elastic end restraints resting on a linear elastic foundation are obtained. Then, the nonlinear vibration equation is solved by ...

Journal: :The European physical journal. E, Soft matter 2009
G A Caballero-Robledo E Clément

We report experimental measurements on the rheology of a dry granular material under a weak level of vibration generated by sound injection. First, we measure the drag force exerted on a wire moving in the bulk. We show that when the driving vibration energy is increased, the effective rheology changes drastically: going from a non-linear dynamical friction behavior --weakly increasing with the...

2004

Basic Terminology of Structural Vibration The term vibration describes repetitive motion that can be measured and observed in a structure. Unwanted vibration can cause fatigue or degrade the performance of the structure. Therefore it is desirable to eliminate or reduce the effects of vibration. In other cases, vibration is unavoidable or even desirable. In this case, the goal may be to understa...

2018
Lin Wang Wenqi Wu Geng Li Xianfei Pan Ruihang Yu

The ring laser gyro (RLG) dither axis will bend and exhibit errors due to the specific forces acting on the instrument, which are known as g-sensitive misalignments of the gyros. The g-sensitive misalignments of the RLG triad will cause severe attitude error in vibration or maneuver environments where large-amplitude specific forces and angular rates coexist. However, g-sensitive misalignments ...

Journal: :journal of applied and computational mechanics 0
gbeminiyi m sobamowo university of lagos

in this paper, nonlinear dynamic behaviours of carbon nanotube conveying fluidwith slip boundary conditions is studied using variation iteration method. the developed solutions are used to investigate the effects of various parameters on the nonlinear vibration of the nanotube. from the result, it is observed that increase in the slip parameter leads to decrease in the frequency of vibration an...

Journal: :journal of computational & applied research in mechanical engineering (jcarme) 2014
rouhollah hosseini keikhosrow firoozbakhsh hossein naseri

because the underlying physiology of pathological tremor in a parkinson's patient is not well understood, the existing physical and drug therapies have not been successful in tremor treatment. different mathematical modeling of such vibration has been introduced to investigate the problem and reduce the existing vibration. most of the models have represented the induced vibration as a sinusoida...

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