The Experts below are selected from a list of 3213 Experts worldwide ranked by ideXlab platform
Frank K Tittel - One of the best experts on this subject based on the ideXlab platform.
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effect of Tensile Stress Amplitude and temporal characteristics on threshold of cavitation driven ablation
Laser-Tissue Interaction VII, 1996Co-Authors: Rinat O Esenaliev, Alexander A Oraevsky, Steven L Jacques, Frank K TittelAbstract:Understanding of laser tissue ablation mechanisms may help to optimize laser ablation parameters in order to achieve minimal thermal and mechanical damage to surrounding tissues. One of the possibility to avoid unwanted thermal and mechanical effects is the use of cavitation-driven ablation. This regime provides ablation of aqueous media at temperatures substantially below 100 degree(s)C. Cavitation-induced ablation can be achieved at Stress- confined irradiation of absorbing media with free surface. Under these irradiation conditions relatively powerful thermoelastic Tensile pressure waves can be generated. The Tensile waves can produce cavitation inside irradiated medium and cavitation-induced ablation. Temporal profile of the Tensile wave depends on absorption coefficient of the medium while Amplitude depends on both absorption coefficient and fluence of laser pulses. In our study effect of the Amplitude and duration of the Tensile waves on threshold of cavitation-induced ablation is investigated. Absorbing aqueous solutions of potassium chromate with various concentrations were irradiated by third harmonic of Q-switched Nd:YAG laser. On the basis of the experimental results, one can conclude that ablation threshold under this irradiation conditions is effected by both Amplitude and temporal characteristics of the Tensile pressure waves. Effect of duration of Tensile pulse is caused by resonance and cooperative phenomena upon cavitation and coalescence of cavitation bubbles in the irradiated volume. Other effects (initial distribution of cavitation bubbles, etc.) are also discussed.
Rinat O Esenaliev - One of the best experts on this subject based on the ideXlab platform.
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effect of Tensile Stress Amplitude and temporal characteristics on threshold of cavitation driven ablation
Laser-Tissue Interaction VII, 1996Co-Authors: Rinat O Esenaliev, Alexander A Oraevsky, Steven L Jacques, Frank K TittelAbstract:Understanding of laser tissue ablation mechanisms may help to optimize laser ablation parameters in order to achieve minimal thermal and mechanical damage to surrounding tissues. One of the possibility to avoid unwanted thermal and mechanical effects is the use of cavitation-driven ablation. This regime provides ablation of aqueous media at temperatures substantially below 100 degree(s)C. Cavitation-induced ablation can be achieved at Stress- confined irradiation of absorbing media with free surface. Under these irradiation conditions relatively powerful thermoelastic Tensile pressure waves can be generated. The Tensile waves can produce cavitation inside irradiated medium and cavitation-induced ablation. Temporal profile of the Tensile wave depends on absorption coefficient of the medium while Amplitude depends on both absorption coefficient and fluence of laser pulses. In our study effect of the Amplitude and duration of the Tensile waves on threshold of cavitation-induced ablation is investigated. Absorbing aqueous solutions of potassium chromate with various concentrations were irradiated by third harmonic of Q-switched Nd:YAG laser. On the basis of the experimental results, one can conclude that ablation threshold under this irradiation conditions is effected by both Amplitude and temporal characteristics of the Tensile pressure waves. Effect of duration of Tensile pulse is caused by resonance and cooperative phenomena upon cavitation and coalescence of cavitation bubbles in the irradiated volume. Other effects (initial distribution of cavitation bubbles, etc.) are also discussed.
Alexander A Oraevsky - One of the best experts on this subject based on the ideXlab platform.
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effect of Tensile Stress Amplitude and temporal characteristics on threshold of cavitation driven ablation
Laser-Tissue Interaction VII, 1996Co-Authors: Rinat O Esenaliev, Alexander A Oraevsky, Steven L Jacques, Frank K TittelAbstract:Understanding of laser tissue ablation mechanisms may help to optimize laser ablation parameters in order to achieve minimal thermal and mechanical damage to surrounding tissues. One of the possibility to avoid unwanted thermal and mechanical effects is the use of cavitation-driven ablation. This regime provides ablation of aqueous media at temperatures substantially below 100 degree(s)C. Cavitation-induced ablation can be achieved at Stress- confined irradiation of absorbing media with free surface. Under these irradiation conditions relatively powerful thermoelastic Tensile pressure waves can be generated. The Tensile waves can produce cavitation inside irradiated medium and cavitation-induced ablation. Temporal profile of the Tensile wave depends on absorption coefficient of the medium while Amplitude depends on both absorption coefficient and fluence of laser pulses. In our study effect of the Amplitude and duration of the Tensile waves on threshold of cavitation-induced ablation is investigated. Absorbing aqueous solutions of potassium chromate with various concentrations were irradiated by third harmonic of Q-switched Nd:YAG laser. On the basis of the experimental results, one can conclude that ablation threshold under this irradiation conditions is effected by both Amplitude and temporal characteristics of the Tensile pressure waves. Effect of duration of Tensile pulse is caused by resonance and cooperative phenomena upon cavitation and coalescence of cavitation bubbles in the irradiated volume. Other effects (initial distribution of cavitation bubbles, etc.) are also discussed.
Steven L Jacques - One of the best experts on this subject based on the ideXlab platform.
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effect of Tensile Stress Amplitude and temporal characteristics on threshold of cavitation driven ablation
Laser-Tissue Interaction VII, 1996Co-Authors: Rinat O Esenaliev, Alexander A Oraevsky, Steven L Jacques, Frank K TittelAbstract:Understanding of laser tissue ablation mechanisms may help to optimize laser ablation parameters in order to achieve minimal thermal and mechanical damage to surrounding tissues. One of the possibility to avoid unwanted thermal and mechanical effects is the use of cavitation-driven ablation. This regime provides ablation of aqueous media at temperatures substantially below 100 degree(s)C. Cavitation-induced ablation can be achieved at Stress- confined irradiation of absorbing media with free surface. Under these irradiation conditions relatively powerful thermoelastic Tensile pressure waves can be generated. The Tensile waves can produce cavitation inside irradiated medium and cavitation-induced ablation. Temporal profile of the Tensile wave depends on absorption coefficient of the medium while Amplitude depends on both absorption coefficient and fluence of laser pulses. In our study effect of the Amplitude and duration of the Tensile waves on threshold of cavitation-induced ablation is investigated. Absorbing aqueous solutions of potassium chromate with various concentrations were irradiated by third harmonic of Q-switched Nd:YAG laser. On the basis of the experimental results, one can conclude that ablation threshold under this irradiation conditions is effected by both Amplitude and temporal characteristics of the Tensile pressure waves. Effect of duration of Tensile pulse is caused by resonance and cooperative phenomena upon cavitation and coalescence of cavitation bubbles in the irradiated volume. Other effects (initial distribution of cavitation bubbles, etc.) are also discussed.
Walter Harrer - One of the best experts on this subject based on the ideXlab platform.
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biaxial Tensile strength test for brittle rectangular plates
Journal of the Ceramic Society of Japan, 2006Co-Authors: Robert Danzer, Peter Supancic, Walter HarrerAbstract:A new biaxial Tensile strength test (ball on three balls test, B3B-test) for brittle materials has been proposed by some of the authors several years ago. A disc-shaped plate is symmetrically supported by three balls at one plane and loaded by a fourth ball in the centre of the opposite plane. This new test has several advantages compared to conventional bending tests or other biaxial strength tests, especially the well defined load transfer geometry and a high tolerance against measurement uncertainties. This makes the testing of as-sintered (slightly buckled) specimens possible. In the past years the test has proved to be very practicable to test as-sintered disc specimens as well as as-sintered specimens which are shaped like a disc. Although discs are—in principle—easy to produce, in some cases it is more convenient to produce specimens having the shape of rectangular plates. Also many components have the shape of rectangular plates. Therefore, in this paper, the B3B-test is extended to test specimens which are that shape. An FE analysis of the Stress fields in the specimens is performed and the maximum Tensile Stress Amplitude and the effective volume in the specimens are determined. Specimens of different size and of several advanced ceramic materials were tested. It is shown that there exists a size effect on strength which can be explained in the framework of the Weibull theory. The B3B strength data determined on rectangular plate specimens fit to tests results determined on disc specimens and to conventional bending test results. The smallest tested specimen had a volume of some tenth of a cubic millimetre. To demonstrate the practicability of the method a strength distribution of an electroceramic component is determined by testing 494 individual rectangular B3B test specimens.
