نتایج جستجو برای: ultrasound power

تعداد نتایج: 592500  

Journal: :The Review of scientific instruments 2008
George K Lewis William L Olbricht

We have developed a portable high power ultrasound system with a very low output impedance amplifier circuit (less than 0.3 Omega) that can transfer more than 90% of the energy from a battery supply to the ultrasound transducer. The system can deliver therapeutic acoustical energy waves at lower voltages than those in conventional ultrasound systems because energy losses owing to a mismatched i...

Journal: :Circulation. Cardiovascular imaging 2015
J Todd Belcik Brian H Mott Aris Xie Yan Zhao Sajeevani Kim Nathan J Lindner Azzdine Ammi Joel M Linden Jonathan R Lindner

BACKGROUND Ultrasound can increase tissue blood flow, in part, through the intravascular shear produced by oscillatory pressure fluctuations. We hypothesized that ultrasound-mediated increases in perfusion can be augmented by microbubble contrast agents that undergo ultrasound-mediated cavitation and sought to characterize the biological mediators. METHODS AND RESULTS Contrast ultrasound perf...

2012
M. R. Doosti R. Kargar M. H. Sayadi

One of innovate techniques that was used for improvement of water treatment process is application of ultrasound waves. In this study, different applications of ultrasound technology in water treatment process such as membrane filtration, turbidity and total suspended solid reduction, algae removal, disinfection process, water softening process and other pollutants removal such as halomethanes ...

2003
S. E. Fick

In a specially designed radiation force balance (RFB), low-frequency pulse modulation of the incident ultrasound allows high-accuracy measurement of time-averaged spatially-integrated ultrasound power radiated into a reflectionless water load. Errors characteristic of force sensors are precluded by operating the RFB as a force comparator, without directly measuring force. Equipped with purpose-...

2005
Martin Gustafsson Martin I. Gustafsson Jerker Delsing

Imagine that the technical development can change the ultrasound measurement systems used for fetus feature detection from the large piece of machinery today, to a wireless coin size system tomorrow. The factor that has reduced the size of electronic systems over time is integration and integrated circuits. In this thesis circuit simulator models of complete ultrasound systems are used to desig...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده ادبیات و زبانهای خارجی 1390

august wilson is undoubtedly one of the rare black playwrights whose works have attracted streams of attention and worldwide audience. the present study aims at analyzing fences and piano lesson which are two of the most successful plays in his pittsburgh cycle from the perspective of michel foucault’s theories and ideas. studying these two plays from foucault’s perspective opens new windows in...

2014
Ye Yao Xingyu Zhang Yiying Guo

High-intensity ultrasound can induce cavitation bubbles and acoustic streaming in liquid, which makes it possible for power ultrasonic to be applied to the improvement of heat transfer process. In the present work, the experimental study was made on the heat transfer enhancement of water-water heat exchanger in shell-and-tube type assisted by power ultrasonic. The design of the experimental sys...

Journal: :پژوهش های علوم و صنایع غذایی ایران 0
elahe maghsoudlou reza esmaeilzaadeh kenari zeinab raftani amiri

recently, subcritical water extraction (swe) has been well known as a green technology for extraction of bioactive compounds from plants. in this study, subcritical water extraction, ultrasound assisted extraction (uae) and shaker solvent extraction (sse) were compared for extraction of phenolic compounds from fig (ficuscarica) pulp and skin. antioxidant activity of the extracts was evaluated u...

Journal: :iranian journal of oil & gas science and technology 2012
mir roozbeh jamei mohammadreza khosravi bagher anvaripour

a new method for the synthesis of nano zero-valent iron (nzvi) was developed in the present study.ultrasonic waves, as a novel method, were used to synthesize the nanoparticles. the morphologyand surface compositions of the particles were characterized by using fesem, xrd, bet, andparticle size analyzer. the synthesized nanoparticles were then utilized as a fenton-like catalyst todegrade of hyd...

اسلامی, فاطمه, علیزاده, مهدی, کوثری, فاطمه,

Background and Objective: Ocular biometry refers to the measurement of the axial length of the eye and thickness of the intraocular structures. This process is routinely performed for all patients before cataract surgery. The accuracy of the biometric data is directly associated with the refractive status after cataract surgery. Currently, two methods of biometry, namely ultrasound and optical ...

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