WorldCat Identities

Crum, Lawrence A.

Overview
Works: 53 works in 87 publications in 2 languages and 343 library holdings
Genres: Conference papers and proceedings  Academic theses 
Roles: Editor, Author, Collector, Other, Thesis advisor, Originator, Honoree
Classifications: QD801, 541.3
Publication Timeline
.
Most widely held works by Lawrence A Crum
Sonochemistry and sonoluminescence by Lawrence A Crum( Book )

11 editions published between 1999 and 2013 in English and held by 162 WorldCat member libraries worldwide

Sonochemistry is studied primarily by chemists and sonoluminescence mainly by physicists, but a single physical phenomenon - acoustic cavitation - unites the two areas. The physics of cavitation bubble collapse, is relatively well understood by acoustical physicists but remains practically unknown to the chemists. By contrast, the chemistry that gives rise to electromagnetic emissions and the acceleration of chemical reactions is familiar to chemists, but practically unknown to acoustical physicists. It is just this knowledge gap that the present volume addresses. The first section of the book addresses the fundamentals of cavitation, leading to a more extensive discussion of the fundamentals of cavitation bubble dynamics in section two. A section on single bubble sonoluminescence follows. The two following sections address the new scientific discipline of sonochemistry, and the volume concludes with a section giving detailed descriptions of the applications of sonochemistry. The mixture of tutorial lectures and detailed research articles means that the book can serve as an introduction as well as a comprehensive and detailed review of these two interesting and topical subjects
10th International Symposium on Therapeutic Ultrasound (ISTU 2010) : Tokyo, Japan, 9-12 June 2010 by International Symposium on Therapeutic Ultrasound (2002- )( )

3 editions published in 2011 in English and held by 79 WorldCat member libraries worldwide

16th International Congress on Acoustics and 135th Meeting Acoustical Society of America : the sound of the future : a global view of acoustics in the 21st century : Seattle, Washington, USA, 20-26 June 1998 by International Congress on Acoustics( Book )

3 editions published in 1998 in English and Spanish and held by 14 WorldCat member libraries worldwide

Sonochemistry and Sonoluminescence( )

in English and held by 7 WorldCat member libraries worldwide

2nd International Symposium on Therapeutic Ultrasound : Seattle, Washington, USA, 29 July-1 August, 2002 : conference proceedings by International Symposium on Therapeutic Ultrasound (2002- )( Book )

1 edition published in 2003 in English and held by 5 WorldCat member libraries worldwide

Synchronous Picosecond Sonoluminescence( )

3 editions published between 1994 and 1996 in English and held by 3 WorldCat member libraries worldwide

The discovery of a single bubble sonoluminescence has led to several interesting and remarkable observations. Among these are picosecond length light flashes and a level of synchronicity several orders of magnitude greater than the period of the applied acoustic field. Although new and unique observations concerning this phenomenon are being rapidly reported, an adequate explanation for the physical mechanisms that give rise to single bubble sonoluminescence has never been given. We describe here a few highlights of our recent research in our ongoing efforts to understand this complex phenomenon
Ultrasonic detection and expulsion of kidney stones by Wei Lu( )

1 edition published in 2012 in English and held by 3 WorldCat member libraries worldwide

Kidney stone disease afflicts 10% of the U.S. population and severely affects the life quality of patients. There are still many problems with the diagnosis and treatment of renal stones. In diagnosis, X-ray computerized tomography (CT) is the most commonly used technology as it allows urologists/radiologists to locate the stone(s) with high sensitivity. Unfortunately, more and more evidence has been collected that shows that the radiation exposure to patients during CT scans may increase the risk of developing cancer. In kidney stone treatments, extracorporeal shock-wave lithotripsy (ESWL), which breaks the stone with shock waves, is widely used as it is non-invasive and allows the fragments to pass naturally; however, small stone fragments located in the lower pole of the kidney often remain in the kidney, which can cause stones to recur in 50% of ESWL patients within 5 years. Therefore, new technologies that allow for better kidney stone detection and treatment are needed. The twinkling artifact (TA) has been shown to highlight kidney stones during color Doppler ultrasound imaging with high sensitivity for stone detection; however, the instability of the TA has prevented it from being adopted clinically. In this dissertation, the mechanism of the TA was investigated based on raw radio-frequency (RF) data collected from in vitro human kidney stones using the MATLABTM Programmable VerasonicsĀ® ultrasound engine. Algorithms, such as beamforming, quadrature demodulation, Doppler processing, etc., were developed to minimize ambiguity in the signal processing. Synthesized RF signals were sent directly into the ultrasound machine in order to separate the acoustic effects from the signal processing effects. It was determined the variability that results in the TA arises from acoustical interactions with the stone. Next, the acoustical effects (i.e., crevice microbubbles, stone ringing, etc.) of the TA were investigated by applying high static pressure (up to 8.5 MPa) on old and fresh human stones where it was determined that microbubbles trapped in crevices on the surface of the stone plays an important role in producing the TA. Modeling simulations were applied to eliminate stone ringing as a possible contributor to the TA. These results have led to the development of new imaging algorithms for better stone detection. A quantitative comparison between the new twinkling image algorithms and the classic color Doppler TA shows that the new imaging techniques are more stable and accurate. Besides improving kidney stone detection, an ultrasound-guided system that is capable of expelling small kidney stones or stone fragments from the kidney has been developed. This device uses acoustic radiation forces and associated acoustic streaming to `push' stones out of the lower pole of the kidney and has been tested successfully in a stone phantom and in many in vivo porcine experiments. Preliminary histological results suggest that the device is safe and that there is no visible thermal or mechanical damage to the kidney. The primary result of this dissertation is insight into the mechanism of the TA, which allowed for the development of new ultrasonic stone-specialized imaging algorithms. In addition, a novel ultrasound technology was developed for expelling small stones or stone fragments from the kidney. Besides furthering science, the results from this dissertation should directly influence patients as it provides improved stone detection and treatment technologies with ultrasound, a non-ionizing alternative to traditional diagnosis regimes, that holds great promise to be adopted clinically
Mie scattering as a technique for the sizing of air bubbles by Gary Michael Hansen( Book )

3 editions published between 1983 and 1984 in English and held by 3 WorldCat member libraries worldwide

A technique has been developed which allows the radius of a bubble in a fluid to be accurately measured without disturbing the bubble. Results are presented which show that radius measurements of single air-bubbles in water can be achieved by shining a He-Ne laser on the bubble and measuring the light scattered at 80 degrees. Light intensity measurements at a scattering angle of 55 degrees were used to calibrate a photodiode detection system and to demonstrate the correlation of data with Mie scattering theory. The photodiode was then moved to 80 degrees for actual radius measurements. This technique was accurate to within 3% for bubbles with radii less than 80 microns. (Author)
The motion of bubbles in a stationary sound field by Lawrence A Crum( Book )

2 editions published in 1969 in English and held by 2 WorldCat member libraries worldwide

The subject of this report is the motion of an air bubble that is propelled through a liquid by a standing acoustic wave. Values are presented for the translational velocities at which bubbles smaller than resonance size move through the sound field. Bubbles were observed in water and in isopropyl alcohol. Bubble radii ranged from 29 to 149 micrometers, and acoustic pressure amplitudes ranged up to 1.1 bar. The resulting bubble velocities, ranging to 23 cm/sec, were measured by photographing a moving bubble under stroboscopic illumination. Calculated and observed values of the bubble velocity are in agreement as long as the bubble translation is rectilinear. Experimental results also indicate that the bubble translation becomes erratic when the pressure amplitude exceeds a threshold value. This threshold appears to be identical to the threshold, determined in a separate experiment, for the onset of dancing motion of stationary bubbles trapped in a sound field. The results of theoretical calculations suggest that both the erratic translation and the dancing motion are caused by nonspherical oscillations of the bubble that are parametrically excited when the pressure amplitude exceeds a threshold value. (Author)
A theoretical investigation of acoustic cavitation by Kerry Wayne Commander( Book )

2 editions published in 1985 in English and held by 2 WorldCat member libraries worldwide

Recent experiments have shown that when the acoustic driving frequency is near one of a bubble's harmonic resonances, the theoretical values predicted by the Rayleigh-Plesset equation are inconsistent with observed values. This inconsistency lead Prosperetti to consider the internal pressure term in the Rayleigh-Plesset equation in a more general manner. In the past the internal pressure of a bubble was assumed to be accurately predicted by a polytropic approximation. Prosperetti considered the internal pressure from the conservation equations, resulting in a much more accurate formulation. This study analyzes the two methods, showing where they agree and where they disagree. The new formulation also provides additional information about the internal thermodynamics of a bubble. Results are shown for the internal temperature of a cavitating bubble as a function of radial coordinate and time. Internal pressures for a variety of conditions are shown and are in good agreement with earlier predicted values. Different models of acoustic cavitation are examined using some of the recent techniques in dynamical systems. 'Feigenbaum trees' were made for the two models. This method for analyzing an equation was shown to be very sensitive to the internal pressure term, and thus is an appropriate method for comparing different acoustic cavitation theories. Keywords: Nonlinear dynamics
General Report: Sonochemistry and Sonoluminescence Conference( Book )

2 editions published in 1998 in English and held by 2 WorldCat member libraries worldwide

The presentation of data that demonstrate that a sonoluminescing bubble can produce observable sonochemistry was also an important and interesting aspect of the ASI. Since sonochemistry has been difficult to study in the past because of the many bubbles that are typically formed within a cavitation field, the development of a system for studying SBSC is considered an important contribution to the field. An additional topic of much discussion was the physical mechanism(s) that lead to the light emission from SBSL. A strongly held theory is that imploding shock waves are developed within the gas during the later stages of bubble collapse. A second view is that asymmetrical collapses of the bubble can lead to liquid jets that penetrate the opposite bubble wall and generate light emission by fractoluminescence. These and many other theories were hotly debated and further calls were made to the experimentalists for additional data
Air bubble growth by rectified diffusion by Lawrence A Crum( Book )

2 editions published in 1980 in English and held by 2 WorldCat member libraries worldwide

Measurements are reported of the growth of air bubbles in water by rectified diffusion at 22.1 kHz. Values of the threshold acoustic pressure amplitude were obtained as a function of bubble radius, liquid surface tension and gas concentration. Measurements of the rate of growth of bubbles by rectified diffusion were also obtained as a function of acoustic pressure amplitude for a range of different values of the liquid-vapor surface tension. It was determined that although both the threshold and the growth rate were in agreement with theory for normal values of the surface tension of water, the addition of a surfactant caused the observed thresholds and growth rates to deviate from the predicted values. Surface wave activity that could increase the diffusion rate by acoustic streaming was not detected at low radii and is not thought to be the principal mechanism for the increased diffusion. Some possible explanations are given for the effect
Proceedings of the 16th International Congress on Acoustics The Sound of the Future: A Global View of Acoustics in the 21st Century by International Congress on Acoustics( Book )

in English and held by 2 WorldCat member libraries worldwide

Energy Focusing in High-Amplitude Sound Fields( Book )

2 editions published in 2005 in English and held by 2 WorldCat member libraries worldwide

The objectives for this project were to better understand sonoluminescence conditions, expand the parameter space for sonoluminescence, enhance the cavitation collapse sequence, and implement enhanced-cavitation generators to search for tritium production. Modeling studies were performed to determine additional paths to unknown stable parameter spaces. Experiments were performed to determine methods and mechanisms for enhancing cavitation collapse. PZT array and spark-gap lithotripter-based systems were designed, built and tested. The spark-gap lithotriper worked as planned, but the count rate was too slow for practical applications. The PZT array system worked, but final testing was not completed because funding was exhausted
Acoustic cavitation inception in water and in isonated root tips by Lawrence A Crum( Book )

1 edition published in 1978 in English and held by 2 WorldCat member libraries worldwide

Sources of ambient noise in the ocean : an experimental investigation by Hugh Charles Pumphrey( Book )

2 editions published in 1989 in English and held by 2 WorldCat member libraries worldwide

The general characteristics of underwater sound produced at the ocean surface have been known for many years and recent measurements have also described the sound of rainfall. The mechanisms which produce these sounds have remained a mystery. This report describes a series of laboratory experiments in which various simple mechanisms in the 0.5-100 kHz frequency range were examined. A large part of the work describes the sounds made by the impact of a drop of water on the water surface. It is found that two types of sound are emitted: first, a sharp spike radiated when the drop first strikes the surface and second, a damped sinewave emitted when a bubble is entrained below the water surface. For a certain range of drop sizes and velocities a bubble will always be entrained; this phenomenon has been named regular entrainment. The hydrodynamics of a drop impact are discussed in an attempt to show why regular entrainment occurs; a qualitative explanation is described using computer modelling. The sound of rainfall on water is studied in detail; an important feature of the acoustic spectrum is a peak at about 14 kHz. It is shown that this peak is caused by regular entrainment and not by initial impacts as one author has suggested. Experimental results enable us to predict the spectrum levels which rain of a given intensity would produce; the predictions compare reasonably well with real rain data. Other experiments examined the sound of a breaking wave and of bubbles interacting with a submerged jet of water. Theses
Measurements of the growth of air bubbles by rectified diffusion by Lawrence A Crum( Book )

2 editions published in 1977 in English and held by 2 WorldCat member libraries worldwide

Measurements are reported of the growth of air bubbles by rectified diffusion at 21.6 kHz. Values of the threshold acoustic pressure amplitude were obtained as a function of bubble radius and liquid surface tension and show good agreement with theory. Measurements of the rate of growth of bubbles by rectified diffusion as a function of acoustic pressure amplitude for varying surface tension show agreement only for high surface tension. When the surface tension is lowered by the addition of a surfactant, the observed growth rates become much larger than predicted. Surface wave activity that could increase the growth rate by acoustic streaming was not observed at low radii and was discounted as the responsible mechanism. A possible explanation for the large growth rates is given in terms of a retardation of outward gas diffusion by an organic monolayer present on the surface of the air bubble
Acoustic cavitation and bubble dynamics by Anthony Armstrong Atchley( Book )

2 editions published in 1985 in English and held by 2 WorldCat member libraries worldwide

The topic of this chapter, acoustic cavitation, is but one of several possible mechanisms through which ultrasound can interact with a liquid medium. Acoustic cavitation can affect a liquid through two possible avenues. The first is the bubble itself. The liquid is disrupted by the inhomogeneous presence of the bubble. The second avenue through which bubbles affect a fluid is through bubble dynamics. The bubble's interior and the liquid immediately surrounding the bubble are regions which undergo continual change. The bubble-liquid interface continually changes shape and size; liquid molecules diffuse into and out of the bubble; the concentration of gas in the surrounding liquid varies; acoustic streaming occurs in the liquid in the vicinity of the bubble often resulting in severe shear stresses; the interior pressure and temperature fluctuate rapidly; the bubble radiates acoustic energy as it oscillates; thermal and viscous damping hinder the bubble oscillations
Experimental observation of the nonlinear response of single bubbles to an applied acoustic field by Ray Glynn Holt( Book )

2 editions published in 1988 in English and held by 2 WorldCat member libraries worldwide

An experimental technique for measuring the time-varying response of an oscillating, acoustically levitated bubble in water is developed. The bubble is levitated in a cell consisting of two concentric, cylindrical, piezoceramic transducers mounted on either end of a short glass tube. The entire apparatus forms a closed-open cylindrical tube which is driven in the cylindrical mode of (1,0,1) at a frequency f= 24kHz. Linearly polarized laser light (He-Ne 632.8, Ar-I 488.) is scattered from a bubble, and the scattered intensity is measured with a suitable photodetector positioned at some known angle from the forward, subtending some solid acceptance angle. The output photodetector current, which is linearly proportional to the light intensity, is converted into a voltage, digitized, and then stored on a computer for analysis. The scattered intensity I sub exp (t) thus obtained contains, in principle, all of the dynamical information about the oscillating bubble, and various methods of analysis are employed to examine the behavior. Complex I exp (t) behavior is also measured, with subharmonics and broad-band noise apparent in the Fourier spectra. This behavior is shown to exhibit high (greater than 2) correlation dimension, indicating the presence of more than one degree of freedom in the motion. Possible explanations for this phenomenon are discussed, including shape oscillations and chaos. Keywords: Inverse transfer functions; Physical acoustics; Lasers; Nonlinear dynamics; Optoacoustics; Chaos; Mie scattering. (jhd)
 
moreShow More Titles
fewerShow Fewer Titles
Audience Level
0
Audience Level
1
  Kids General Special  
Audience level: 0.70 (from 0.63 for Mie scatte ... to 0.99 for Ultrasonic ...)

Sonochemistry and sonoluminescence Sonochemistry and sonoluminescence : [proceedings of the NATO Advanced Study Institute on Sonochemistry and Sonoluminescence, Leavenworth, Washington, USA, 18-29 August 1997]
Covers
Sonochemistry and sonoluminescence : [proceedings of the NATO Advanced Study Institute on Sonochemistry and Sonoluminescence, Leavenworth, Washington, USA, 18-29 August 1997]
Alternative Names
Crum, Larry 1941-

Languages