scholarly journals Time reversal of continuous-wave, steady-state signals in elastic media

2009 ◽  
Vol 94 (11) ◽  
pp. 111908 ◽  
Author(s):  
Brian E. Anderson ◽  
Robert A. Guyer ◽  
Timothy J. Ulrich ◽  
Paul A. Johnson
Keyword(s):  
Steady State ◽  
Time Reversal ◽  
Continuous Wave ◽  
Elastic Media

scholarly journals Energy dissipation and fluctuations in a driven liquid

2018 ◽  
Vol 115 (14) ◽  
pp. 3569-3574 ◽  
Author(s):  
Clara del Junco ◽  
Laura Tociu ◽  
Suriyanarayanan Vaikuntanathan
Keyword(s):  
Phase Transition ◽  
Steady State ◽  
Time Reversal ◽  
Time Dependent ◽  
Time Reversal Symmetry ◽  
Nonequilibrium Systems ◽  
Minimal Models ◽  
Stochastic Thermodynamics ◽  
Periodic Steady State ◽  
Time Periodic

Minimal models of active and driven particles have recently been used to elucidate many properties of nonequilibrium systems. However, the relation between energy consumption and changes in the structure and transport properties of these nonequilibrium materials remains to be explored. We explore this relation in a minimal model of a driven liquid that settles into a time periodic steady state. Using concepts from stochastic thermodynamics and liquid state theories, we show how the work performed on the system by various nonconservative, time-dependent forces—this quantifies a violation of time reversal symmetry—modifies the structural, transport, and phase transition properties of the driven liquid.

Energy flux imaging method for time reversal in elastic media.

2009 ◽  
Vol 125 (4) ◽  
pp. 2521-2521
Author(s):  
Brian E. Anderson ◽  
Robert A. Guyer ◽  
Timothy J. Ulrich ◽  
Pierre‐Yves Le Bas ◽  
Carene Larmat ◽  
...  
Keyword(s):  
Energy Flux ◽  
Time Reversal ◽  
Imaging Method ◽  
Elastic Media

scholarly journals LABORATORY PHOTOGRAMMETRIC WAVE HEIGHT MEASUREMENT

1982 ◽  
Vol 1 (18) ◽  
pp. 44
Author(s):  
J.D. Pos ◽  
F.A. Kilner
Keyword(s):  
Steady State ◽  
Wave Height ◽  
Continuous Wave ◽  
Wave Train ◽  
Contour Plot ◽  
Height Measurement ◽  
Experimental Procedure ◽  
Infinite Extent ◽  
Monochromatic Waves

The paper describes the experimental procedure used to produce a computor contour plot of the wave height distributions and wave directions in a model basin, using photogrammetric techniques. Only monochromatic waves are analysed. A technique is outlined to simulate and measure waves entering a basin of infinite extent, in other words to photograph the penetration of a wave train into a harbour basin before the pattern has been contaminated by reflections. Proof is offered that this infinite basin technique is a valid representation of the steady state situation of a continuous wave train entering an infinite basin.

scholarly journals Laser Induced Temperature Perturbation on Ultramicroelectrodes: Unsupported Solutions in Nonaqueous Methanol

2022 ◽  
Author(s):  
Salvador Gutierrez-Portocarrero ◽  
Pradeep Subedi ◽  
Mario A. Alpuche-Aviles
Keyword(s):  
Diffusion Coefficient ◽  
Steady State ◽  
Temperature Dependence ◽  
Continuous Wave ◽  
High Resistivity ◽  
Temperature Perturbation ◽  
Colloidal Systems ◽  
Steady State Current ◽  
Before And After ◽  
Electron Transfer Processes

Abstract Temperature dependence studies of electrochemical parameters provide insight into electron transfer processes. In cases where adding excess electrolyte experimental causes complications colloidal systems, organic or biological samples it is preferable to deal with the high resistivity of the medium. We validate the use of unsupported and weakly supported solutions in thermoelectrochemical experiments. The temperature dependence of the diffusion coefficient allows calibration of the steady-state current to measure changes when a continuous wave (CW) ultraviolet laser, λ=325 nm, illuminates an ultramicroelectrode (UME) from the front. Calibrating the steady-state current ratios before and after heating with a thermostatic bath allows temperature measurements within an accuracy of 0.6 K. The solutions are without supporting electrolytes in methanol, a volatile solvent, and we use a model that accurately describes the viscosity and temperature dependence of the solvent. We calculated the temperature and derived an equation to estimate the temperature measurement error. A numeric method yields satisfactory results, considering the changes for both diffusion coefficients and viscosity explicitly, and predict the thermostatic temperature bath, agreeing with the theoretical model's error. In unsupported solutions, the ferrocene diffusion coefficient and the iodide apparent diffusion coefficient follow the expected increase with temperature. Under CW laser illumination ΔT=4±1 K.

Quantifying the depth profile of time reversal focusing in elastic media

2014 ◽  
Vol 136 (4) ◽  
pp. 2265-2265
Author(s):  
Brian E. Anderson ◽  
Marcel C. Remillieux ◽  
Timothy J. Ulrich ◽  
Pierre-Yves Le Bas
Keyword(s):  
Depth Profile ◽  
Time Reversal ◽  
Elastic Media

Steady-state thermo-optic model of a continuous-wave Raman laser

2002 ◽  
Vol 19 (6) ◽  
pp. 1318 ◽  
Author(s):  
Joshua C. Bienfang ◽  
Wolfgang Rudolph ◽  
Peter A. Roos ◽  
Lei S. Meng ◽  
John L. Carlsten
Keyword(s):  
Steady State ◽  
Continuous Wave ◽  
Raman Laser

Time-reversal algorithms in viscoelastic media

2013 ◽  
Vol 24 (4) ◽  
pp. 565-600 ◽  
Author(s):  
HABIB AMMARI ◽  
ELIE BRETIN ◽  
JOSSELIN GARNIER ◽  
ABDUL WAHAB
Keyword(s):  
Time Reversal ◽  
Viscoelastic Medium ◽  
Cross Correlation ◽  
Helmholtz Decomposition ◽  
Elastic Media ◽  
Attenuation Effect ◽  
Imaging Algorithm ◽  
Viscoelastic Media ◽  
First Order ◽  
Correlation Techniques

In this paper we consider the problem of reconstructing sources in a homogeneous viscoelastic medium from wavefield measurements. We first present a modified time-reversal imaging algorithm based on a weighted Helmholtz decomposition and justify mathematically that it provides a better approximation than by simply time reversing the displacement field, where artifacts appear due to the coupling between the pressure and shear waves. Then we investigate the source inverse problem in an elastic attenuating medium. We provide a regularized time-reversal imaging which corrects the attenuation effect at the first order. The results of this paper yield the fundamental tools for solving imaging problems in elastic media using cross-correlation techniques.

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