نتایج جستجو برای: ultrasonic

تعداد نتایج: 28251  

Alimohammad Faizi, Alireza Akbarzadeh-baghban, Alireza Sabbaghian, Frideh Dehghan-manshadi, Mehri Ghasemi, Tayebeh Mirhashemi,

Background:  Some studies show that frozen shoulder is due to the pathologic changes in the muscles around the shoulder. Measurement of the ultrasonic thickness of a muscle is a method for measuring the muscle changes. There is no study about the reliability of measurement of the muscle’s ultrasonic thickness around the shoulder in patients with frozen shoulder. The present study aims to invest...

2014
Shaofei Wu

The matched spectrum and correlation characteristics are both important to realize the multichannel ultrasonic sensors working together. The spectrum matching can make full use of the bandwidth of the ultrasonic ranging system, and the good correlation characteristic can eliminate crosstalk among multichannel ultrasonic sensors triggering simultaneously. Linear frequency modulation (LFM) excita...

Journal: :Environmental technology 2015
Yinxin Gao Ran Ding Song Wu Yunqiang Wu Yu Zhang Min Yang

Ultrasonic technology is a promising tool for washing oily sludge to recover oil. In this study, the influence of ultrasonic conditions on the removal of different oil components from oily sludge was investigated to optimize ultrasonic washing technology. Among the three frequencies (25, 50 and 100 kHz) applied, ultrasonic washing at 25 kHz exhibited the best performance in terms of oil extract...

Journal: :Journal of clinical periodontology 2004
Søren Jepsen Mustafa Ayna Jürgen Hedderich Jörg Eberhard

OBJECTIVES Ultrasonic scalers have become increasingly popular for subgingival debridement. The aim of the present study was to investigate the influence of different working tip designs (narrow versus wide) on root substance loss caused by either magnetostrictive or piezoelectric ultrasonic devices. METHODS In this in vitro study, a magnetostrictive ultrasonic system with either Slimline or ...

2012
Chunyu Yu Chao Guo Jia-yi Liang Tong Wang

According to the shortcomings of the existing ultrasonic wind velocity measurement device, for instance, complexity of circuit and difficulty of signal processing, a new ultrasonic wind velocity measurement is put forward based on phase discrimination and a new sensor configuration as well. Thus, a system model is built. Firstly, an equilateral triangle should be constituted by an ultrasonic em...

Journal: :Journal of the American Association for Laboratory Animal Science : JAALAS 2007
Christine V Portfors

Many laboratory rodents emit ultrasonic vocalizations. The purpose of this review is to highlight the types and functions of ultrasonic vocalizations emitted by laboratory rats and mice. Rats emit 3 types of ultrasonic vocalizations, depending on the animal's age, its environmental conditions, and its affective state. Rat pups emit a 40-kHz vocalization when they are separated from their mother...

2008
Junji TAKATSUBO Bo WANG Hidekazu MIYAUCHI Hiroshi TSUDA Nobuyuki TOYAMA Kei URABE

If it were possible to perform ultrasonic inspections while observing the propagation of ultrasonic waves as dynamic images, the identification of defect echoes would become easier, and inspection, quicker. Furthermore, fewer defects would be overlooked or improperly identified, leading to higher-reliability inspections. For visualizing ultrasonic propagation, we have developed a generation las...

2009
Ting Wu Zhaoying Zhou Qun Wang Xing Yang Mingfei Xiao

Although ultrasound cavitation must be avoided for safe diagnostic applications, the ability of ultrasound to disrupt cell membranes has taken on increasing significance as a method to facilitate drug and gene delivery. A new ultrasonic resonance driving method is introduced to penetrate rigid wall plant cells or oocytes with springy cell membranes. When a reasonable design is created, ultrasou...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2015
Qin Zhou Jinglin Zheng Seita Onishi M F Crommie Alex K Zettl

We present a graphene-based wideband microphone and a related ultrasonic radio that can be used for wireless communication. It is shown that graphene-based acoustic transmitters and receivers have a wide bandwidth, from the audible region (20∼20 kHz) to the ultrasonic region (20 kHz to at least 0.5 MHz). Using the graphene-based components, we demonstrate efficient high-fidelity information tra...

2004
Jung Gon Kim Hyungsu Kim Han Soo Kim Jae Wook Lee

In this study, an ultrasonic technique was employed to obtain pressure-volume-temperature (PVT) relationship of polymer melt by measuring ultrasonic velocities under various temperatures and pressures. The proposed technique was applied to on-line monitoring of injection molding process as an attempt to predict quality of molded parts. From the comparison based on Tait equation, it was confirme...

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