The Experts below are selected from a list of 1785 Experts worldwide ranked by ideXlab platform
J.a. Porro - One of the best experts on this subject based on the ideXlab platform.
-
Physical characterization of laser interaction and shock generation in laser shock processing: Coupled theoretical-experimental analysis
2012Co-Authors: José Luis Ocaña, Miguel Morales, J.a. Porro, C. Correa, Cristóbal Colón, A. Alonso, Michel L. AutricAbstract:Laser Shock Processing is developing as a key technology for the improvement of surface mechanical and corrosion resistance properties of metals due to its ability to introduce intense compressive residual stresses fields into high elastic limit materials by means of an intense laser driven shock wave generated by laser with intensities exceeding the 109 W/cm2 threshold, pulse energies in the range of 1 Joule and interaction times in the range of several ns. However, because of the relatively difficult-to-describe physics of shock wave formation in plasma following laser-matter interaction in solid state, only limited knowledge is available in the way of full comprehension and Predictive Assessment of the characteristic physical processes and material transformations with a specific consideration of real material properties. In the present paper, an account of the physical issues dominating the development of LSP processes from a moderately high intensity laser-matter interaction point of view is presented along with the theoretical and computational methods developed by the authors for their Predictive Assessment and new experimental contrast results obtained at laboratory scale.
-
Model based analysis of the effect of irradiation parameters on the plasma driven thermal fluxes in laser shock processing
CLEO Europe - EQEC 2009 - European Conference on Lasers and Electro-Optics and the European Quantum Electronics Conference, 2009Co-Authors: M. Morales, J.a. Porro, C. Molpeceres, R. Sevillano, M. Holgado, J.l. OcanaAbstract:This paper presents a simulation study of the phenomenology arising from plasma expansion between the confinement layer and the base material, which is specifically addressed as a clear factor that influences the subsequent thermo-mechanical behaviour of the treated specimens. Results based on the calculation model show that a number of process scaling laws have been obtained, which allow a Predictive Assessment of the thermal/mechanical effects induced in laser shock processing (LSP) treated component as a function of key process parameters such as laser intensity, interaction zone dimension, nature and thickness of confining medium, and overlapping pulse density. Hence, this enables the practical implementation of LSP as a profitable method for the enhancement of surface mechanical properties of metallic materials.
-
Model based plasma monitoring methods for the Predictive Assessment of LSP applications
2007 European Conference on Lasers and Electro-Optics and the International Quantum Electronics Conference, 2007Co-Authors: J.l. Ocana, Miguel Morales, C. Molpeceres, R. Pecharroman, J.a. PorroAbstract:The most simplified methods reported in the literature for the analysis of the LSP phenomenology try to induce the intensity and temporal profile of the shock wave launched into the treated solid material by means of the analysis of the impulse conservation between the external interface of such material and the frontier of the confining material without any reference to the detailed physics of the plasma formation process taking place in the outermost layers of the solid target: this plasma is assumed to be built up to certain degree as a consequence of the initial laser energy deposition, but no analysis is provided about its real dynamics.
-
Application of plasma monitoring methods to the optimized design of laser shock processing applications
High-Power Laser Ablation VI, 2006Co-Authors: José Luis Ocaña, Carlos Molpeceres, Miguel Morales, J.a. PorroAbstract:Although significant work has been conducted in order to explore the optimum conditions of application of LSP treatments and to assess their capability to provide enhanced mechanical properties, only limited attempts have been developed in the way of Predictive Assessment of the characteristic physical processes and transformations with a specific consideration of the associated laser interaction dynamics. For this reason, additionally to the authors' efforts in the line of the numerical Predictive Assessment of the effects induced by the LSP technique from a predominantly mechanical point of view, the observation and analysis of the plasma dynamics following laser interaction have been envisaged as a means for the proper Assessment of the shocking process relative to the material target and also as a way of plasma dynamics control in view of process optimization. In the present paper, the basis for the plasma spectroscopic observation of LSP experiments in combination to numerical dynamics simulations are proposed as a means for the extraction of relevant guidelines for process design optimization.
-
Numerical simulation of laser shock processing of metal alloys
CLEO Europe. 2005 Conference on Lasers and Electro-Optics Europe 2005., 2005Co-Authors: M. Morales, J.a. Porro, C. Molpeceres, J. Torres, J.l. OcanaAbstract:Laser shock processing has been proposed as a competitive alternative technology to classical treatments for improving fatigue and wear resistance of metals, and has more recently been developed as a practical process amenable to production technology. For this reason, a decided attempt has been envisaged on the line of the numerical Predictive Assessment of the effects induced by the LSP technique in some representative metal alloys as a means of enabling a method for practical technology evaluation and optimization amenable to experimental validation. Concretely, the 3D analysis of material deformations and residual stresses fields has been envisaged and some representative results are presented
José Luis Ocaña - One of the best experts on this subject based on the ideXlab platform.
-
Physical characterization of laser interaction and shock generation in laser shock processing: Coupled theoretical-experimental analysis
2012Co-Authors: José Luis Ocaña, Miguel Morales, J.a. Porro, C. Correa, Cristóbal Colón, A. Alonso, Michel L. AutricAbstract:Laser Shock Processing is developing as a key technology for the improvement of surface mechanical and corrosion resistance properties of metals due to its ability to introduce intense compressive residual stresses fields into high elastic limit materials by means of an intense laser driven shock wave generated by laser with intensities exceeding the 109 W/cm2 threshold, pulse energies in the range of 1 Joule and interaction times in the range of several ns. However, because of the relatively difficult-to-describe physics of shock wave formation in plasma following laser-matter interaction in solid state, only limited knowledge is available in the way of full comprehension and Predictive Assessment of the characteristic physical processes and material transformations with a specific consideration of real material properties. In the present paper, an account of the physical issues dominating the development of LSP processes from a moderately high intensity laser-matter interaction point of view is presented along with the theoretical and computational methods developed by the authors for their Predictive Assessment and new experimental contrast results obtained at laboratory scale.
-
TEMPLUM: a process adapted numerical simulation code for the 3D Predictive Assessment of laser surface heat treatments in planar geometry
WSEAS Transactions on Computers archive, 2008Co-Authors: Ángel García-beltrán, José Luis Ocaña, Carlos MolpeceresAbstract:A process adapted numerical simulation code for the 3D Predictive Assessment of laser heat treatment of materials has been developed. Primarily intended for the analysis of the laser transformation hardening of steels, the code has been successfully applied for the Predictive characterization of other metallic and non metallic materials posing specific difficulties from the numerical point of view according to their extreme thermal and absorption properties. Initially based on a conventional FEM calculational structure, the developed code (TEMPLUM) reveals itself as an extremely useful prediction tool with specific process adapted features (not usually available in FEM heat transfer codes) in the field of laser heat treatment applications.
-
Application of plasma monitoring methods to the optimized design of laser shock processing applications
High-Power Laser Ablation VI, 2006Co-Authors: José Luis Ocaña, Carlos Molpeceres, Miguel Morales, J.a. PorroAbstract:Although significant work has been conducted in order to explore the optimum conditions of application of LSP treatments and to assess their capability to provide enhanced mechanical properties, only limited attempts have been developed in the way of Predictive Assessment of the characteristic physical processes and transformations with a specific consideration of the associated laser interaction dynamics. For this reason, additionally to the authors' efforts in the line of the numerical Predictive Assessment of the effects induced by the LSP technique from a predominantly mechanical point of view, the observation and analysis of the plasma dynamics following laser interaction have been envisaged as a means for the proper Assessment of the shocking process relative to the material target and also as a way of plasma dynamics control in view of process optimization. In the present paper, the basis for the plasma spectroscopic observation of LSP experiments in combination to numerical dynamics simulations are proposed as a means for the extraction of relevant guidelines for process design optimization.
-
Model for the coupled Predictive Assessment of plasma expansion and material compression in laser shock processing applications
High-power lasers and applications, 2000Co-Authors: José Luis Ocaña, Miguel Morales, C. Molpeceres, Ángel García-beltránAbstract:In the present paper, a model is presented aiming to provide a physical basis for the theoretical estimation of both the plasma expansion dynamics following laser irradiation and the shock wave propagation into the treated material with a specific consideration of its constitutional properties (i.e. taking into account its real mechanical and E.O.S. parameters). Although initially limited to a 1D description, the proposed model aims to overcome the difficulties existing for an accurate theoretical estimation of the process due to the treated material behavior not directly amenable to analytical solutions and sometimes modeled through empirical approaches, and to provide a detailed treatment of the plasma behavior (i.e. ionization, breakdown, etc.). Additionally, and as a direct consequence of its analytical-numerical character, the model can provide a fully time dependent representation of the processes, including the laser pulse temporal profile, what is a real advance over previous theoretical studies.
J.l. Ocana - One of the best experts on this subject based on the ideXlab platform.
-
Model based analysis of the effect of irradiation parameters on the plasma driven thermal fluxes in laser shock processing
CLEO Europe - EQEC 2009 - European Conference on Lasers and Electro-Optics and the European Quantum Electronics Conference, 2009Co-Authors: M. Morales, J.a. Porro, C. Molpeceres, R. Sevillano, M. Holgado, J.l. OcanaAbstract:This paper presents a simulation study of the phenomenology arising from plasma expansion between the confinement layer and the base material, which is specifically addressed as a clear factor that influences the subsequent thermo-mechanical behaviour of the treated specimens. Results based on the calculation model show that a number of process scaling laws have been obtained, which allow a Predictive Assessment of the thermal/mechanical effects induced in laser shock processing (LSP) treated component as a function of key process parameters such as laser intensity, interaction zone dimension, nature and thickness of confining medium, and overlapping pulse density. Hence, this enables the practical implementation of LSP as a profitable method for the enhancement of surface mechanical properties of metallic materials.
-
Model based plasma monitoring methods for the Predictive Assessment of LSP applications
2007 European Conference on Lasers and Electro-Optics and the International Quantum Electronics Conference, 2007Co-Authors: J.l. Ocana, Miguel Morales, C. Molpeceres, R. Pecharroman, J.a. PorroAbstract:The most simplified methods reported in the literature for the analysis of the LSP phenomenology try to induce the intensity and temporal profile of the shock wave launched into the treated solid material by means of the analysis of the impulse conservation between the external interface of such material and the frontier of the confining material without any reference to the detailed physics of the plasma formation process taking place in the outermost layers of the solid target: this plasma is assumed to be built up to certain degree as a consequence of the initial laser energy deposition, but no analysis is provided about its real dynamics.
-
Numerical simulation of laser shock processing of metal alloys
CLEO Europe. 2005 Conference on Lasers and Electro-Optics Europe 2005., 2005Co-Authors: M. Morales, J.a. Porro, C. Molpeceres, J. Torres, J.l. OcanaAbstract:Laser shock processing has been proposed as a competitive alternative technology to classical treatments for improving fatigue and wear resistance of metals, and has more recently been developed as a practical process amenable to production technology. For this reason, a decided attempt has been envisaged on the line of the numerical Predictive Assessment of the effects induced by the LSP technique in some representative metal alloys as a means of enabling a method for practical technology evaluation and optimization amenable to experimental validation. Concretely, the 3D analysis of material deformations and residual stresses fields has been envisaged and some representative results are presented
Miguel Morales - One of the best experts on this subject based on the ideXlab platform.
-
Physical characterization of laser interaction and shock generation in laser shock processing: Coupled theoretical-experimental analysis
2012Co-Authors: José Luis Ocaña, Miguel Morales, J.a. Porro, C. Correa, Cristóbal Colón, A. Alonso, Michel L. AutricAbstract:Laser Shock Processing is developing as a key technology for the improvement of surface mechanical and corrosion resistance properties of metals due to its ability to introduce intense compressive residual stresses fields into high elastic limit materials by means of an intense laser driven shock wave generated by laser with intensities exceeding the 109 W/cm2 threshold, pulse energies in the range of 1 Joule and interaction times in the range of several ns. However, because of the relatively difficult-to-describe physics of shock wave formation in plasma following laser-matter interaction in solid state, only limited knowledge is available in the way of full comprehension and Predictive Assessment of the characteristic physical processes and material transformations with a specific consideration of real material properties. In the present paper, an account of the physical issues dominating the development of LSP processes from a moderately high intensity laser-matter interaction point of view is presented along with the theoretical and computational methods developed by the authors for their Predictive Assessment and new experimental contrast results obtained at laboratory scale.
-
Model based plasma monitoring methods for the Predictive Assessment of LSP applications
2007 European Conference on Lasers and Electro-Optics and the International Quantum Electronics Conference, 2007Co-Authors: J.l. Ocana, Miguel Morales, C. Molpeceres, R. Pecharroman, J.a. PorroAbstract:The most simplified methods reported in the literature for the analysis of the LSP phenomenology try to induce the intensity and temporal profile of the shock wave launched into the treated solid material by means of the analysis of the impulse conservation between the external interface of such material and the frontier of the confining material without any reference to the detailed physics of the plasma formation process taking place in the outermost layers of the solid target: this plasma is assumed to be built up to certain degree as a consequence of the initial laser energy deposition, but no analysis is provided about its real dynamics.
-
Application of plasma monitoring methods to the optimized design of laser shock processing applications
High-Power Laser Ablation VI, 2006Co-Authors: José Luis Ocaña, Carlos Molpeceres, Miguel Morales, J.a. PorroAbstract:Although significant work has been conducted in order to explore the optimum conditions of application of LSP treatments and to assess their capability to provide enhanced mechanical properties, only limited attempts have been developed in the way of Predictive Assessment of the characteristic physical processes and transformations with a specific consideration of the associated laser interaction dynamics. For this reason, additionally to the authors' efforts in the line of the numerical Predictive Assessment of the effects induced by the LSP technique from a predominantly mechanical point of view, the observation and analysis of the plasma dynamics following laser interaction have been envisaged as a means for the proper Assessment of the shocking process relative to the material target and also as a way of plasma dynamics control in view of process optimization. In the present paper, the basis for the plasma spectroscopic observation of LSP experiments in combination to numerical dynamics simulations are proposed as a means for the extraction of relevant guidelines for process design optimization.
-
Model for the coupled Predictive Assessment of plasma expansion and material compression in laser shock processing applications
High-power lasers and applications, 2000Co-Authors: José Luis Ocaña, Miguel Morales, C. Molpeceres, Ángel García-beltránAbstract:In the present paper, a model is presented aiming to provide a physical basis for the theoretical estimation of both the plasma expansion dynamics following laser irradiation and the shock wave propagation into the treated material with a specific consideration of its constitutional properties (i.e. taking into account its real mechanical and E.O.S. parameters). Although initially limited to a 1D description, the proposed model aims to overcome the difficulties existing for an accurate theoretical estimation of the process due to the treated material behavior not directly amenable to analytical solutions and sometimes modeled through empirical approaches, and to provide a detailed treatment of the plasma behavior (i.e. ionization, breakdown, etc.). Additionally, and as a direct consequence of its analytical-numerical character, the model can provide a fully time dependent representation of the processes, including the laser pulse temporal profile, what is a real advance over previous theoretical studies.
Claudine Piérard-franchimont - One of the best experts on this subject based on the ideXlab platform.
-
Corneosurfametry: A Predictive Assessment of the Interaction of Personal-Care Cleansing Products with Human Stratum corneum
Dermatology, 1994Co-Authors: Gérald E. Piérard, Véronique Goffin, Claudine Piérard-franchimontAbstract:Objective: Corneosurfametry is introduced as a noninvasive quantitative test rating the interaction between surfactants and human stratum corneum. It may be used as a Predictive irr
-
Corneosurfametry: A Predictive Assessment of the interaction of personal-care cleansing products with human stratum corneum
Dermatology, 1994Co-Authors: Gérald E. Piérard, V. Goffrn, Claudine Piérard-franchimontAbstract:OBJECTIVE Corneosurfametry is introduced as a noninvasive quantitative test rating the interaction between surfactants and human stratum corneum. It may be used as a Predictive irritancy test. BACKGROUND Surfactants present in personal-care products elicit multiple effects on the stratum corneum. With upcoming regulations avoiding animal experiments and ethical considerations for human testing, there is a need for new in vitro methods evaluating irritancy. DESIGN Corneosurfametry entails collection of cyanoacrylate skin surface strippings and short contact time with surfactants followed by staining samples with toluidine blue and basic fuchsin dyes. Measurements are made by reading the color of samples using reflectance colorimetry. RESULTS The intensity of color increases with irritancy potential of the surfactant. Results are reproducible, and great differences are noted among a series of diluted shampoos, shower gels and facial cleansing gels. CONCLUSION Corneosurfametry is proposed as a rapid in vitro method allowing a Predictive grading of surfactants related to irritancy.