Strong Scattering of Ultrasonic Waves in Fluidized Suspensions PDF Download

Author: Michael L. Cowan
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

View

Book Description

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description
This thesis presents the results of three main experimental projects; a study of ultrasonic wave propagation in strongly scattering materials, the use of the results of this first study to develop new techniques in ultrasonic correlation spectroscopy, and the use of these techniques to measure the dynamics of particles in fluidized beds. The first project involves the investigation of wave propagation in random, inhomogeneous materials that scatter ultrasound strongly (i.e. materials where the scattering mean free path is comparable to the ultrasonic wavelength [lambda]). I have measured the velocities of the weak ballistic pulse that travels through these materials without scattering out of the forward direction. Using the results of this wave propagation study, we have developed two new ultrasonic spectroscopy techniques. Dynamic Sound Scattering (DSS) uses singly scattered sound to measure the rms velocity of scatterers. Diffusing Acoustic Wave Spectroscopy (DAWS) uses multiply scattered sound, describedby the diffusion approximation, to measure the relative motion of scatterers. This thesis explains the underlying principles governing these techniques and the ways that these techniques can be implemented in practice to provide powerful new methods for investigating the dynamics of strongly scattering materials. Using DAWS and DSS, I have investigated the dynamics of particles suspended against sedimentation by a fluid flowing upwards in a fluidized bed. Since ultrasonic wavelengths are on the order of millimeters, the suspensions that can be Probed contain particles with diameters on the millimeter scale; this corresponds to a regime that is of interest in industrial applications. Thus DAWS and DSS are well suited to the high Reynolds number, high volume fraction suspensions to which other current techniques are least suited. In our experiments, the velocity fluctuations and velocity correlation lengths are measured as a function of the volume fraction and sampl.

Author: Bart A. van Tiggelen
Publisher: Springer Science & Business Media
ISBN: 9401002274
Category : Technology & Engineering
Languages : en
Pages : 637

View

Book Description
A collection of lectures on a variety of modern subjects in wave scattering, including fundamental issues in mesoscopic physics and radiative transfer, recent hot topics such as random lasers, liquid crystals, lefthanded materials and time-reversal, as well as modern applications in imaging and communication. There is a strong emphasis on the interdisciplinary aspects of wave propagation, including light and microwaves, acoustic and elastic waves, propagating in a variety of "complex" materials (liquid crystals, media with gain, natural media, magneto-optical media, photonic and phononic materials, etc.). It addresses many different items in contemporary research: mesoscopic fluctuations, localization, radiative transfer, symmetry aspects, and time-reversal. It also discusses new (potential) applications in telecommunication, soft matter and imaging.

Author: Roman Gr. Maev
Publisher: Springer Science & Business Media
ISBN: 1441986065
Category : Medical
Languages : en
Pages : 510

View

Book Description
This book constitutes the Proceedings of the 26th Symposium on Acoustical Imaging held inWindsor, Ontario, Canada during September 9-12, 2001. This traditional scientific event is recognized as a premier forum for the presentation of advanced research results in both theoretical and experimental development. The lAIS was conceived at a 1967Acoustical Holography meeting in the USA. Since then, these traditional symposia provide an opportunity for specialists who are working in this area to make new acquaintances, renew old friendships and present recent results of their research. Our Symposium has grown significantly in size due to a broad interest in various topics and to the quality of the presentations. For the firsttime in 40 years, the IAIS was held in the province of Ontario in Windsor, Canada's Automotive Capital and City of Roses. The 26th IAIS attracted over 100specialists from 13countries representing this interdisciplinary field in physical acoustics, image processing, applied mathematics, solid-state physics, biology and medicine, industrial applications and quality control technologies. The 26th lAIS was organized in the traditional way with only one addition-a Special Session "History of Acoustical Imaging" with the involvement of such well known scientists as Andrew Briggs, Noriyoshi Chubachi, Robert Green Jr., Joie Jones, Kenneth Erikson, and Bernhard Tittmann. Many of these speakers are well known scientists in their fields and we would like to thank them for making this session extremely successful.

Author: Malcolm J.W. Povey
Publisher: Academic Press
ISBN: 9780125637305
Category : Science
Languages : en
Pages : 232

View

Book Description
This book is a comprehensive and practical guide to the use of ultrasonic techniques for the characterization of fluids. Focusing on ultrasonic velocimetry, the author covers the basic topics and techniques necessaryfor successful ultrasound measurements on emulsions, dispersions, multiphase media, and viscoelastic/viscoplastic materials. Advanced techniques such as scattering, particle sizing, and automation are also presented. As a handbook for industrial and scientific use, Ultrasonic Techniques for Fluids Characterization is an indispensable guide to chemists and chemical engineers using ultrasound for research or process monitoring in the chemical, food processing, pharmaceutical, cosmetic, biotechnology,and fuels industries. Appeals to anyone using ultrasound to study fluids Provides the first detailed description of the ultrasound profiling technique for dispersions Describes new techniques for measuring phase transitions and nucleation, such as water/ice and oil/fat Presents the latest ultrasound techniques for particle sizing in concentrated systems Explains new techniques for compressibility measurements in dispersions and fluids, including cell suspensions Contains a detailed treatment of ultrasound scattering theory Written by one of the leading researchers in the field Includes over 350 references to the primary literature

Author: Jaime Yeargans
Publisher:
ISBN:
Category :
Languages : en
Pages : 96

View

Book Description

Author: William Kurt Hildebrand
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

View

Book Description
Ultrasonic wave transport in strongly scattering, disordered media is investigated via analysis of the multiply-scattered transmitted field. Measurements of transverse confinement, statistics, and correlations of the intensity were performed on an aluminum mesoglass, where aluminum beads were brazed together to form a porous slab sample. Comparison of the transverse confinement measurements with the self-consistent theory of localization was used to identify and locate a mobility edge in the sample at f = 1.1011 MHz, enabling a measurement of the critical exponent nu characterizing the Anderson transition, nu ~ 1.6-2. Infinite-range C0 correlations were observed, and observed to grow dramatically near the mobility edge, along with the C2 and C3 correlations. Measurements of the multifractal exponent Delta_2 were able to confirm the link between C0 correlations and Anderson localization. Experiments using the aluminum mesoglass with ethanol-filled pores showed evidence of two nearly-independent propagating modes, one of which appears to be characterized by a strongly renormalized diffusion coefficient. The density of states and level spacing statistics were investigated using a different mesoglass, constructed by sintering glass beads percolated on a random lattice. Direct measurements of these quantities were obtained by cutting small samples of this mesoglass, allowing individual vibrational modes to be resolved. The density of states showed a plateau extending well into the expected Debye regime, and evidence of a Boson peak was observed at low frequencies. The level spacing statistics indicated that transport in the frequency ranges measured was on the diffusive side of the mobility edge, showing agreement with the predictions of the GOE from random matrix theory. The dynamics of a suspension of bubbles were investigated using phase-based Diffusing Acoustic Wave Spectroscopy, where phase correlations were found to give additional information beyond traditional field- and intensity-based correlation measurements.

Author: Karl F. Herzfeld
Publisher: Academic Press
ISBN: 1483275701
Category : Science
Languages : en
Pages : 554

View

Book Description
Absorption and Dispersion of Ultrasonic Waves focuses on the influence of ultrasonics on molecular processes in liquids and gases, including hydrodynamics, energy exchange, and chemical reactions. The book first offers information on the Stokes-Navier equations of hydrodynamics, as well as equations of motion, viscosity, formal introduction of volume viscosity, and linearized wave equation for a nonviscous fluid. The manuscript then ponders on energy exchange between internal and external degrees of freedom as relaxation phenomenon; effect of slow energy exchange on sound propagation; different ways of evaluating the dispersion curve; and exact calculation of absorption and dispersion. The text examines the effects of chemical reactions, thermodynamic theory of relaxation, and mixtures. The book also evaluates the absorption of high intensity sound waves, ratio of relaxation absorption to classical absorption at maximum, and gas mixtures. Discussions also focus on translational relaxation in monatomic gases, linear triatomic molecules, and results for rotational relaxation. The manuscript is a dependable source of data for readers interested in the absorption and dispersion of ultrasonic waves.

Author: Joseph L. Rose
Publisher: Cambridge University Press
ISBN: 9780521548892
Category : Science
Languages : en
Pages : 480

View

Book Description
Explains the physical principles of wave propagation and relates them to ultrasonic wave mechanics and the more recent guided wave techniques that are used to inspect and evaluate aircraft, power plants, and pipelines in chemical processing. An invaluable reference to this active field for graduate students, researchers, and practising engineers.

Author: Avadh Behari Bhatia
Publisher: Courier Corporation
ISBN: 0486649172
Category : Science
Languages : en
Pages : 450

View

Book Description
Standard reference in the field provides a clear, systematically organized introductory review of fundamental concepts for advanced graduate students and research workers. Numerous diagrams. Bibliography.