Effect of overpressure and pulse repetition frequency on cavitation in shock wave lithotripsy

2002 ◽  
Vol 112 (3) ◽  
pp. 1183-1195 ◽  
Author(s):  
Oleg A. Sapozhnikov ◽  
Vera A. Khokhlova ◽  
Michael R. Bailey ◽  
James C. Williams ◽  
James A. McAteer ◽  
...  
Keyword(s):  
Shock Wave ◽  
Shock Wave Lithotripsy ◽  
Pulse Repetition Frequency ◽  
Repetition Frequency ◽  
Pulse Repetition

Influence of Pulse Repetition Rate on Cavitation at the Surface of an Object Targeted by Lithotripter Shock Waves

2007 ◽  
Author(s):  
Yuri A. Pishchalnikov ◽  
Mark M. Kaehr ◽  
James A. McAteer
Keyword(s):  
Shock Wave ◽  
High Speed ◽  
Shock Wave Lithotripsy ◽  
Bubble Dynamics ◽  
Pulse Repetition Frequency ◽  
Pulse Repetition ◽  
Bubble Collapse ◽  
High Speed Imaging ◽  
Bubble Density ◽  
Induced Stresses

Stone breakage in shock wave lithotripsy is improved by slowing the rate of shock wave (SW) delivery. Previous studies have shown that increased cavitation at fast pulse repetition frequency (PRF) reduces the tensile phase of the SW, while the leading positive wave is virtually unaffected. Since the tensile component of the SW drives cavitation, and since cavitation at the stone contributes to breakage, it seems likely that increased cavitation along the path to the stone affects cavitation at the stone. Here we present preliminary data suggesting that PRF influences bubble dynamics at the stone. High-speed imaging showed that as PRF increased, bubble density of cavitation clouds increased, and the size of individual bubbles decreased. A new method to measure stresses generated by cavitation was used to show that locally induced stresses from bubble collapse can be greater than the incident SW, and were higher at 0.5Hz than at 2Hz PRF.

scholarly journals Effects of Non-thermal Ultrasound on a Fibroblast Monolayer Culture: Influence of Pulse Number and Pulse Repetition Frequency

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5040
Author(s):  
Silvia Ronda Peñacoba ◽  
Mar Fernández Gutiérrez ◽  
Julio San Román del Barrio ◽  
Francisco Montero de Espinosa
Keyword(s):  
Short Pulse ◽  
Pulse Repetition Frequency ◽  
Pulse Number ◽  
Repetition Frequency ◽  
Pulse Repetition ◽  
Treatment Protocols ◽  
Culture Plate ◽  
New Treatment ◽  
Long Pulse

Despite the use of therapeutic ultrasound in the treatment of soft tissue pathologies, there remains some controversy regarding its efficacy. In order to develop new treatment protocols, it is a common practice to carry out in vitro studies in cell cultures before conducting animal tests. The lack of reproducibility of the experimental results observed in the literature concerning in vitro experiments motivated us to establish a methodology for characterizing the acoustic field in culture plate wells. In this work, such acoustic fields are fully characterized in a real experimental configuration, with the transducer being placed in contact with the surface of a standard 12-well culture plate. To study the non-thermal effects of ultrasound on fibroblasts, two different treatment protocols are proposed: long pulse (200 cycles) signals, which give rise to a standing wave in the well with the presence of cavitation (ISPTP max = 19.25 W/cm2), and a short pulse (five cycles) of high acoustic pressure, which produces a number of echoes in the cavity (ISPTP = 33.1 W/cm2, with Pmax = 1.01 MPa). The influence of the acoustic intensity, the number of pulses, and the pulse repetition frequency was studied. We further analyzed the correlation of these acoustic parameters with cell viability, population, occupied surface, and cell morphology. Lytic effects when cavitation was present, as well as mechanotransduction reactions, were observed.

Aqueous Benzene Oxidation in Low-Temperature Plasma of Pulsed Corona Discharge

2016 ◽  
Vol 19 (2) ◽  
Author(s):  
Iakov Kornev ◽  
Sergei Preis
Keyword(s):  
Low Temperature ◽  
Corona Discharge ◽  
Gas Phase ◽  
Pulse Repetition Frequency ◽  
Repetition Frequency ◽  
Pulse Repetition ◽  
Benzene Oxidation ◽  
Low Temperature Plasma ◽  
Temperature Plasma ◽  
Pulsed Corona

AbstractWastewaters polluted with non-biodegradable volatile organic compounds (VOCs), such as aromatic substances, present a growing problem meeting no adequately affordable technological response. Low-temperature plasma generated in the gas-phase pulsed corona discharge (PCD) presents competitive advanced oxidation technology in abatement of various classes of pollutants, although the process parameters, the pulse repetition frequency and the liquid spray rate, require optimization. The experimental research into aqueous benzene oxidation with PCD was undertaken to establish the impact of the parameters to the energy efficiency. The oxidation reaction was found under the experimental conditions to mostly proceed in the gas phase showing little influence of the pulse repetition frequency and the gas-liquid contact surface. Oxidation of benzene and, presumably, other volatile pollutants in the volume of PCD reactor compartment presents an effective strategy of aqueous VOCs abatement.

Adaptive Pulse Repetition Frequency Technique for an Ultrasonic Transit-Time Gas Flowmeter for Hot Pulsating Gases

2006 ◽  
Vol 6 (4) ◽  
pp. 906-915 ◽  
Author(s):  
M. Kupnik ◽  
A. Schroder ◽  
P. O'Leary ◽  
E. Benes ◽  
M. Groschl
Keyword(s):  
Transit Time ◽  
Pulse Repetition Frequency ◽  
Repetition Frequency ◽  
Pulse Repetition

High pulse repetition frequency all-solid-state 1053 nm Nd:YLF laser

2010 ◽  
Vol 7 (10) ◽  
pp. 722-725 ◽  
Author(s):  
Y. Sun ◽  
H. Zhang ◽  
Q. Liu ◽  
L. Huang ◽  
Y. Wang ◽  
...  
Keyword(s):  
Solid State ◽  
Pulse Repetition Frequency ◽  
Repetition Frequency ◽  
Pulse Repetition ◽  
High Pulse ◽  
High Pulse Repetition Frequency
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