Andrei B . Utkin - Academia.edu (original) (raw)

Uploads

Papers by Andrei B . Utkin

Research paper thumbnail of Waves produced by a travelling line current pulse with high-frequency filling

Days on Diffraction, 2010, 2005

A model of the travelling-wave line source of electromagnetic waves is extended to the case of a ... more A model of the travelling-wave line source of electromagnetic waves is extended to the case of a line current pulse with high-frequency filling. No limitation on the modulation phase velocity is assumed and peculiarities of the, emanated waves corresponding to subluminal, luminal, and superluminal phase velocities of modulation of the source current are discussed

Research paper thumbnail of Comparison of eye-safe UV and IR lidar

Research paper thumbnail of Forest fire detection by means of lidar, Forest fire research and wildland safety

Research paper thumbnail of Lidar system controlled by computer for smoke identification applied, in particular, to early stage forest fire detection

Research paper thumbnail of Detection of forest fire using lidar

Research paper thumbnail of Classification of lidar signals by committee machines applied to automatic forest fire detection

Research paper thumbnail of Application of Particle Image Velocimetry Technique for Study of Reacting Jet Flows

Xvii International Symposium on Gas Flow, Chemical Lasers, and High-Power Lasers, 2009

ABSTRACT Present work is devoted to experimental study of reacting jet flow in a model open flame... more ABSTRACT Present work is devoted to experimental study of reacting jet flow in a model open flame burner. The work was inspired by the problem of extension of the range for stable and effective combustion which basically determined by the turbulent flow structure in reaction zone. To approach this target spatial distributions of the mean velocity, turbulent kinetic energy were measured and the role of organized vortical structures have been studied.The main technique used is a laser based stereo Particle Image Velocimetry (PIV) system. The measurements were performed in a central section of the jet flame. Regular swirl parameter of the flow was varied from 0 to 1.0. Reynolds number was changed between 1000 and 8000. Equivalence ratio variation band was between 0.5 and 4. Effect of the nozzle geometry was studied by using nozzles with different exit diameters.

Research paper thumbnail of Experimental and theoretical investigation of forest fire detection by a portable eye-safe lidar operating at 1540 nm

Xvii International Symposium on Gas Flow, Chemical Lasers, and High-Power Lasers, 2009

Research paper thumbnail of Analysis of Residual Stress and Corrosion Resistance of Laser Shock-Processed 6012 and 6082 Aluminium Alloys

Xvii International Symposium on Gas Flow, Chemical Lasers, and High-Power Lasers, 2009

The paper provides a thorough analysis of a surface layer prior to and after Laser Shock Processi... more The paper provides a thorough analysis of a surface layer prior to and after Laser Shock Processing under different parameter conditions. Optimum conditions were determined using a factorial design aided with an analysis of variance (ANOVA). As the first experimental factor, pulse density with 900 and 2500 pulse/cm 2 was chosen. The second factor was the type of material, i.e. aluminium alloys ENAW 6012 and ENAW 6082. Evaluation of different conditions of specimen treatment was made using three response variables, i.e. surface roughness, magnitude of residual stresses, and corrosion resistance given by pitting potential (Epitt). A thorough analysis of the modified surface layer was made with measurement of microhardness, and with images obtained in optical and electronic microscopy (SEM) and energy dispersion spectroscopy (EDS) to determine corrosion products around the pits formed after corrosion testing. The experiments confirmed characteristic influences of individual LSP parameters on properties of the treated material surfaces. ENAW 6012 aluminium alloy showed better corrosion resistance than ENAW 6082 alloy with lower pitting attack at its surface. Corrosion tests showed that a higher pulse density produces shifting of the pitting potential to more positive values, which ensures higher corrosion resistance from the viewpoint of preserving a passive protecting film on the surface layer.

Research paper thumbnail of <title>Comparison of eye-safe UV and IR lidar for small forest-fire detection</title>

Remote Sensing for Agriculture, Ecosystems, and Hydrology III, 2002

Lidar is a promising tool for forest-fire monitoring because this active detection technique allo... more Lidar is a promising tool for forest-fire monitoring because this active detection technique allows efficient location of tenuous smoke plumes resulting from forest fires at their early stages. For the technique to be generally usable, instrumentation must be eye-safe, i. e. it must operate within the spectral range λ<0.4 or λ>1.4 µm. In this paper the lidar efficiency at the wavelengths 0.3472 µm (second harmonic of the ruby laser) and 1.54 µm (Er:glass laser) are compared using a theoretical model. The results of calculations show that the energy required for smoke-plume detection using 0.3472 µm becomes greater than the corresponding value for 1.54 µm when the distance exceeds some threshold, which ranges between 2 and 6 km depending on other parameters. Being caused by relatively higher absorption of the UV radiation in the atmosphere, this result is valid for any wavelength in the vicinity of 0.35 µm, for example, the third harmonic of Nd:YAG laser and the second harmonic of Ti:sapphire laser.

Research paper thumbnail of <title>Bioactive ceramic glasses in situ synthesized by laser melting</title>

XVII International Symposium on Gas Flow, Chemical Lasers, and High-Power Lasers, 2008

The synthesis of bioactive glass from raw materials even during the laser deposition process, cou... more The synthesis of bioactive glass from raw materials even during the laser deposition process, could provide formation of a biocompatible layer on the metallic prosthesis. During the laser irradiation melting and ultrarapid solidification of ceramic materials occur and glasses controlled by the process parameters (especially laser power and solidification rate) will be obtained. The aim of the present paper is

Research paper thumbnail of XVII International Symposium on Gas Flow, Chemical Lasers, and High-Power Lasers

title page. Papers were selected and subject to review by the editors and conference program comm... more title page. Papers were selected and subject to review by the editors and conference program committee. Some conference presentations may not be available for publication. The papers published in these proceedings reflect the work and thoughts of the authors and are published herein as submitted. The publisher is not responsible for the validity of the information or for any outcomes resulting from reliance thereon.

Research paper thumbnail of Gas Flow, Chemical Lasers, and High-Power Lasers

Research paper thumbnail of Optical Methods for Water Pollution Monitoring

Spatial and …, 2011

An innovative optical method for remote monitoring of water pollution was developed and tested in... more An innovative optical method for remote monitoring of water pollution was developed and tested in AMPERA ERA-NET Programme, project DEOSOM. The method is based on remote detection of laser-induced fluorescent radiation (LIF LIDAR). In the project, compact and ...

Research paper thumbnail of Waves produced by a travelling line current pulse with high-frequency filling

Days on Diffraction, 2010, 2005

A model of the travelling-wave line source of electromagnetic waves is extended to the case of a ... more A model of the travelling-wave line source of electromagnetic waves is extended to the case of a line current pulse with high-frequency filling. No limitation on the modulation phase velocity is assumed and peculiarities of the, emanated waves corresponding to subluminal, luminal, and superluminal phase velocities of modulation of the source current are discussed

Research paper thumbnail of Comparison of eye-safe UV and IR lidar

Research paper thumbnail of Forest fire detection by means of lidar, Forest fire research and wildland safety

Research paper thumbnail of Lidar system controlled by computer for smoke identification applied, in particular, to early stage forest fire detection

Research paper thumbnail of Detection of forest fire using lidar

Research paper thumbnail of Classification of lidar signals by committee machines applied to automatic forest fire detection

Research paper thumbnail of Application of Particle Image Velocimetry Technique for Study of Reacting Jet Flows

Xvii International Symposium on Gas Flow, Chemical Lasers, and High-Power Lasers, 2009

ABSTRACT Present work is devoted to experimental study of reacting jet flow in a model open flame... more ABSTRACT Present work is devoted to experimental study of reacting jet flow in a model open flame burner. The work was inspired by the problem of extension of the range for stable and effective combustion which basically determined by the turbulent flow structure in reaction zone. To approach this target spatial distributions of the mean velocity, turbulent kinetic energy were measured and the role of organized vortical structures have been studied.The main technique used is a laser based stereo Particle Image Velocimetry (PIV) system. The measurements were performed in a central section of the jet flame. Regular swirl parameter of the flow was varied from 0 to 1.0. Reynolds number was changed between 1000 and 8000. Equivalence ratio variation band was between 0.5 and 4. Effect of the nozzle geometry was studied by using nozzles with different exit diameters.

Research paper thumbnail of Experimental and theoretical investigation of forest fire detection by a portable eye-safe lidar operating at 1540 nm

Xvii International Symposium on Gas Flow, Chemical Lasers, and High-Power Lasers, 2009

Research paper thumbnail of Analysis of Residual Stress and Corrosion Resistance of Laser Shock-Processed 6012 and 6082 Aluminium Alloys

Xvii International Symposium on Gas Flow, Chemical Lasers, and High-Power Lasers, 2009

The paper provides a thorough analysis of a surface layer prior to and after Laser Shock Processi... more The paper provides a thorough analysis of a surface layer prior to and after Laser Shock Processing under different parameter conditions. Optimum conditions were determined using a factorial design aided with an analysis of variance (ANOVA). As the first experimental factor, pulse density with 900 and 2500 pulse/cm 2 was chosen. The second factor was the type of material, i.e. aluminium alloys ENAW 6012 and ENAW 6082. Evaluation of different conditions of specimen treatment was made using three response variables, i.e. surface roughness, magnitude of residual stresses, and corrosion resistance given by pitting potential (Epitt). A thorough analysis of the modified surface layer was made with measurement of microhardness, and with images obtained in optical and electronic microscopy (SEM) and energy dispersion spectroscopy (EDS) to determine corrosion products around the pits formed after corrosion testing. The experiments confirmed characteristic influences of individual LSP parameters on properties of the treated material surfaces. ENAW 6012 aluminium alloy showed better corrosion resistance than ENAW 6082 alloy with lower pitting attack at its surface. Corrosion tests showed that a higher pulse density produces shifting of the pitting potential to more positive values, which ensures higher corrosion resistance from the viewpoint of preserving a passive protecting film on the surface layer.

Research paper thumbnail of <title>Comparison of eye-safe UV and IR lidar for small forest-fire detection</title>

Remote Sensing for Agriculture, Ecosystems, and Hydrology III, 2002

Lidar is a promising tool for forest-fire monitoring because this active detection technique allo... more Lidar is a promising tool for forest-fire monitoring because this active detection technique allows efficient location of tenuous smoke plumes resulting from forest fires at their early stages. For the technique to be generally usable, instrumentation must be eye-safe, i. e. it must operate within the spectral range λ<0.4 or λ>1.4 µm. In this paper the lidar efficiency at the wavelengths 0.3472 µm (second harmonic of the ruby laser) and 1.54 µm (Er:glass laser) are compared using a theoretical model. The results of calculations show that the energy required for smoke-plume detection using 0.3472 µm becomes greater than the corresponding value for 1.54 µm when the distance exceeds some threshold, which ranges between 2 and 6 km depending on other parameters. Being caused by relatively higher absorption of the UV radiation in the atmosphere, this result is valid for any wavelength in the vicinity of 0.35 µm, for example, the third harmonic of Nd:YAG laser and the second harmonic of Ti:sapphire laser.

Research paper thumbnail of <title>Bioactive ceramic glasses in situ synthesized by laser melting</title>

XVII International Symposium on Gas Flow, Chemical Lasers, and High-Power Lasers, 2008

The synthesis of bioactive glass from raw materials even during the laser deposition process, cou... more The synthesis of bioactive glass from raw materials even during the laser deposition process, could provide formation of a biocompatible layer on the metallic prosthesis. During the laser irradiation melting and ultrarapid solidification of ceramic materials occur and glasses controlled by the process parameters (especially laser power and solidification rate) will be obtained. The aim of the present paper is

Research paper thumbnail of XVII International Symposium on Gas Flow, Chemical Lasers, and High-Power Lasers

title page. Papers were selected and subject to review by the editors and conference program comm... more title page. Papers were selected and subject to review by the editors and conference program committee. Some conference presentations may not be available for publication. The papers published in these proceedings reflect the work and thoughts of the authors and are published herein as submitted. The publisher is not responsible for the validity of the information or for any outcomes resulting from reliance thereon.

Research paper thumbnail of Gas Flow, Chemical Lasers, and High-Power Lasers

Research paper thumbnail of Optical Methods for Water Pollution Monitoring

Spatial and …, 2011

An innovative optical method for remote monitoring of water pollution was developed and tested in... more An innovative optical method for remote monitoring of water pollution was developed and tested in AMPERA ERA-NET Programme, project DEOSOM. The method is based on remote detection of laser-induced fluorescent radiation (LIF LIDAR). In the project, compact and ...