نتایج جستجو برای: ultrasonic oscillation

تعداد نتایج: 66673  

2000
Jürgen Maas Thomas Schulte Norbert Fröhleke

A complete model-based control for traveling-wavetype ultrasonic motors is presented in this paper. The control scheme consists of inner control loops with respect to the oscillation systems, offering all meaningful degrees of freedom for adjusting the traveling bending wave, and outer control loops for torque and speed. After a brief review on modeling the actuator and presentation of a parame...

Journal: :Medical engineering & physics 1998
H Honda S Nakaya H Kamada H Hasegawa J Demachi H Chikama K Sugimura Y Yamamoto N Kumasaka T Takita J Ikeda H Kanai Y Koiwa K Shirato

Sato et al. (Electronic Letters 32, 949-950, 1996) reported that one can obtain a non-invasive estimate of left ventricular (LV) pressure at around end-diastole in an isolated canine preparation. In this study we examined whether this method can be applied to humans. Using the method proposed by Kanai et al. (IEEE. Trans. UFFC, 43, 791-810,1996), we detected small amplitude LV vibration from an...

Journal: :British heart journal 1974
Y Nimura H Matsuo T Hayashi A Kitabatake S Mochizuki

Flow velocity spectra of main arteries in 24 healthy adult subjects and 21 healthy aged subjects were transcutaneously studied using the directional ultrasonic Doppler technique. I) The instantaneous flow velocity spectrum is continuous throughout a pulse cycle, and intensified near the instantaneous maximum velocity, especially in the earlypart ofa pulse cycle. 2) No reverse flow phase is obse...

Journal: :Physical review. E, Statistical, nonlinear, and soft matter physics 2010
Takatoshi Yanagisawa Yasuko Yamagishi Yozo Hamano Yuji Tasaka Kanako Yano Jumpei Takahashi Yasushi Takeda

Thermal convection experiments in a liquid gallium layer were carried out with various intensities of uniform horizontal magnetic fields. The gallium layer was in a rectangular vessel with a 4:1:1 length ratio (1 is the height), where the magnetic field is applied in the direction normal to the longest vertical wall. An ultrasonic velocity profiling method was used to visualize the spatiotempor...

بحرینی نژاد, طیبه, عابدینی, عباس,

In this paper, the effect of compressive viscosity on the slow mode oscillation of solar corona loops is studied. The coronal loops medium are considered in low beta condition, uniform magnetic field in the presence of gravitational stratification and temperature gradient. Two-dimensional Magneto-Hydro-Dynamics (MHD) equations are perturbed about the equilibrium and thenthese equations are lin...

امیرحسینی, طاهره, عابدینی, عباس,

Slow magneto-acoustic waves are often observed in polar plumes and active region fan loops. The observed periodicities of these waves are in the range of 1- 40 minutes. Mainly, the ratio of damping time to the oscillation period is less than 2 (equal to the ratio damping length to the wave length), which corresponds to the strong damping regime. In general, slow magneto-acoustic waves can be da...

Journal: :ماشین های کشاورزی 0
رسول معمار دستجردی سعید مینایی محمد هادی خوش تقاضا

development of ultrasound technique has not been progressing for evaluating the internal quality of fruits as fast as that of processed foods. in this research for quality assessment of pear fruit (shah miveh variety) an ultrasonic measurement system was constructed to transmit and receive the ultrasonic waves. the apparatus included a pulser-receiver, a pair of 75 khz ultrasonic transducers wi...

Journal: :iranian endodontic journal 0
zahed mohammadi sousan shalavi luciano giardino flavio palazzi saeed asgary

using ultrasonic devices in endodontics can enhance the antibacterial and tissue dissolving ability of different root canal irrigants such as sodium hypochlorite (naocl) which is the most common irrigant with excellent antibacterial and tissue dissolving abilities. however, due to its high surface tension, its penetration into the irregularities of the root canal system is a challenge. the purp...

2013
Tao Gao Zhen-Jing Yao Lifeng Zhang

Both the spectrum and correlation characteristics are important in constructing excitation sequences to realize the multichannel ultrasonic sensors working together. For LFM excitation sequence, there should not be too many simultaneously fired ultrasonic sensors, because of the limited available frequency band of the ultrasonic ranging system. The optimized CFM excitation sequences are propose...

The purpose of this study was to investigate the effects of the North Atlantic Oscillation on the middle levels of Atmosphere and precipitation changes in the West of country. To do this, first monthly rainfall data of 17 synoptic stations of the West Country in period of 30 years from 1984 to 2014 of country were collected from Meteorological Organization. As well as North Atlantic Oscillation...

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