نتایج جستجو برای: vibration frequency

تعداد نتایج: 524993  

Journal: :The Journal of experimental biology 1991
C Shingyoji I R Gibbons A Murakami K Takahashi

The heads of live spermatozoa of the sea urchin Hemicentrotus pulcherrimus were held by suction in the tip of a micropipette mounted on a piezoelectric device and vibrated either laterally or axially with respect to the head axis. Within certain ranges of frequency and amplitude, lateral vibration of the pipette brought about a stable rhythmic beating of the flagella in the plane of vibration, ...

رجبی, مجید , معصومی, امین اله , همت , عباس ,

Due to yield increase, some farmers in Iran plant sugarbeet in 50-cm row spacing instead of conventional 60-cm row spacing. Low row spacings force farmers to harvest three consecutive rows instead of two alternate rows. This would increase the amount of draft requirement to pull the lifter through the soil. In order to use common medium tractors for pulling the three-unit sugarbeet lifter and p...

2013
Yan Liu

This study use noise and vibration analytical system to test and analyze the noise and vibration of subway station hall, draw the conclusion: analysis the noise test results when the vehicles through the subway station hall. The noise rises as the frequency increases, gets the peak value nearby 5000 Hz, the high of test point gives lesser influence to noise contribution. The vibration occurred ...

ژورنال: علوم آب و خاک 2008
رجبی, مجید , معصومی, امین اله , همت , عباس ,

Due to yield increase, some farmers in Iran plant sugarbeet in 50-cm row spacing instead of conventional 60-cm row spacing. Low row spacings force farmers to harvest three consecutive rows instead of two alternate rows. This would increase the amount of draft requirement to pull the lifter through the soil. In order to use common medium tractors for pulling the three-unit sugarbeet lifter and p...

2014
Daria Chmielewska Magdalena Piecha Edward Błaszczak Piotr Król Agnieszka Smykla Grzegorz Juras

Vibration training has become a popular method used in professional sports and recreation. In this study, we examined the effect of whole-body vibration training on the central nervous system and muscle excitability in a group of 28 active men. Subjects were assigned randomly to one of two experimental groups with different variables of vibrations. The chronaximetry method was used to evaluate ...

2005
Jin Luo Brian McNamara Kieran Moran

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 1. Inclusion/Exclusion Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 2. Literature Search . . . . . . . . . . . . . . . . . . . . ...

Journal: :Industrial health 2012
Ren G Dong Daniel E Welcome Thomas W McDowell Xueyan S Xu Kristine Krajnak John Z Wu

The objective of this study is to propose a theory on the biodynamic frequency weighting for studying hand-transmitted vibration exposures and vibration-induced effects. We hypothesize that the development of a vibration effect is the result of two consecutive but synergistic processes: biodynamic responses to input vibration and biological responses to the biomechanical stimuli resulting from ...

Journal: :تحقیقات نظام سلامت 0
اصغر نیک روش استادیار، گروه مهندسی بهداشت حرفه ای، دانشگاه علوم پزشکی شیراز، شیراز، ایران زهرا زمانیان دانشجوی کارشناسی ارشد ارگونومی، گروه ارگونومی، دانشگاه علوم پزشکی شیراز، شیراز، ایران مجتبی خدادادی مربی، گروه روانشناسی، دانشگاه امام حسین(ع)، تهران، ایران محمدرضا منظم دانشیار، گروه مهندسی بهداشت حرفه ای، دانشگاه علوم پزشکی تهران، تهران، ایران جعفر حسن زاده دانشیار، گروه اپیدمیولوژی، دانشگاه علوم پزشکی شیراز، شیراز، ایران

background: deficiency of attention and concentration is one of great reasons of traffic incidents and it covers between 20 to 50 percent of events due to careless and mindedness. studies show that attention and concentration are considered as one of important cognitive components in safe driving. vibration is an important physical effect in all vehicles. till now has not been any organized stu...

A Fatahi-Vajari, Z Azimzadeh

This paper investigates the coupled axial-radial (CAR) vibration of single-walled carbon nanotubes (SWCNTs) based on doublet mechanics (DM) with a scale parameter. Two coupled forth order partial differential equations that govern the CAR vibration of SWCNTs are derived. It is the first time that DM is used to model the CAR vibration of SWCNTs. To obtain the natural frequency and dynamic respon...

Journal: :EURASIP J. Adv. Sig. Proc. 2016
Weijie Xia LinLin Huang

An efficient vibration estimation method for synthetic aperture radar (SAR) systems based on phase-analysis method is presented. Small vibrations, which consist of multiple frequency components and are usually rather weak, introduce phase modulation in radar echoes. They contain important signatures of objects. Extracting and analyzing the phase from radar echoes is one of the significant appro...

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