نتایج جستجو برای: ultrasonic

تعداد نتایج: 28251  

2011
Yuan Gao Yitong Zhou Xiaoli Zhang Liping Zhang Ping Qu

A series of materials used for oil absorption based on cellulose fiber grafted with butyl acrylate (BuAc) have been prepared by radical polymerization under ultrasonic waves processing. Effects of ultrasonic dose for the maximum graft yield were considered. The dependency of optimum conditions for oil absorption rate on parameters such as ultrasonic processing time and ultrasonic power were als...

Journal: :JNW 2012
Zhenjing Yao Tao Gao Guo Li

The crosstalk in multichannel simultaneously triggered ultrasonic sensors of ultrasonic ranging system may cause false measurement. This paper presents pseudorandom digital modulation excitation sequences for multichannel ultrasonic sensors to avoid crosstalk. To make full use of bandwidth of the ultrasonic sensors, the parameters of the pseudorandom digital modulation methods are configured. A...

Journal: :The Journal of the Acoustical Society of America 2004
Liyong Yang Joseph A Turner

Scattering of ultrasonic waves in polycrystals with texture is studied in this article. The attenuations of the three wave modes are determined as a function of dimensionless frequency and propagation direction, respectively, for given orientation distribution coefficients (ODCs). The calculation is done in the case of a statistically orthorhombic sample made up of cubic crystallites. The wave ...

Journal: :مجله دانشگاه علوم پزشکی کرمانشاه 0
mohammad hadi dehghani zoheyr norozi elham nikfar noshin rastkari

background: bisphenol-a is categorized as a toxic and refractory organic matter. ultrasonic process considered as an effective method for degradation of refractory organic matters in the environment which is achieved by the production of fine bubbles through cavitation process. this study is conducted for assessment of the toxicity of effluents containing bisphenol-a which was treated by ultras...

Journal: :The Journal of the Acoustical Society of America 1978
S A Goss L A Frizzell F Dunn

The earlier report that the frequency dependence of ultrasonic absorption of mammalian testis memicked a single relaxation process is explained as an effect of ultrasonic beam width upon the transient thermoelectric technique. More detailed measurements show that the frequency dependence of the ultrasonic absorption in testis is much the same as the attenuation in other soft tissues, viz., a pr...

It has been proved that ultrasonic energy can considerably increase the amount of oil recovery in an immiscible displacement process. Although many studies have been performed on investigating the roles of ultrasonic waves, based on the best of our knowledge, little attention has been paid to evaluate wave attenuation parameter, which is an important parameter in the determination of the energy...

2004
Keiji Yasuda Eiji Fujimori Yoshiyuki Bando Soyoko Yamaguchi Masaaki Nakamura Yasuhito Kawase

When the high power ultrasound irradiates the liquid, small liquid droplets are generated from the liquid surface. This phenomenon is called as ultrasonic atomization [1]. Recently, it has been reported that ethanol is concentrated from the aqueous solution by ultrasonic atomization [2-4]. Since ultrasonic atomization scarcely accompanies the phase change, this is a great advantage comparing wi...

2005
Bao Mi Thomas E. Michaels Jennifer E. Michaels

Successful in-situ monitoring of crack initiation and growth is a necessary prerequisite for applying ultrasonic methods to structural health monitoring. For conventional ultrasonic testing methods, a focused beam may be used to directly image the crack tip; however, this method is difficult to apply during fatigue testing because of access limitations and couplant contamination issues. However...

Journal: :Folia primatologica; international journal of primatology 2015
Sharon Gursky

Although the vocalizations of spectral tarsiers have been studied for over 3 decades by numerous primatologists, the data in this paper represent the first evidence that this species communicates in the ultrasonic range. In addition, this paper characterizes the types of ultrasonic vocalizations by spectral tarsiers, Tarsius spectrum. Data were collected at Tangkoko Nature Reserve in Sulawesi, ...

Flavonoids, are a large class of polyphenols, with more than 4000 combinations. They have an antioxidant role in plant photosynthesis and in the human body they optimally act as an antioxidant, anti-inflammatory, anticancer and protector of the heart. Quercetin is in the flavonol group that is used to fight protection specifically against viruses and cancer cells. In this study, Comparison of e...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید