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Tytuł:
Magnetothermoelastic vibrations on a viscoelastic microbeam subjected to a laser heat source
Autorzy:
Abouelregal, A. E.
Zenkour, A. M.
Powiązania:
https://bibliotekanauki.pl/articles/38614523.pdf
Data publikacji:
2021
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
thermoviscoelasticity
microbeams
laser pulse
magnetic field
Opis:
The linear theory of viscoelasticity remains an important field of research like most solids and polymer materials when exposed to a vicious dynamic loading effect. This article introduces a new model for describing the behavior of thermoviscoelastic microbeams considering the effects of temperature change and the longitudinal magnetic field. The governing equations in this model are derived based on the Euler–Bernoulli beam theory, Kelvin–Voigt model of viscosity, the generalized thermoelasticity, and the classical Maxwell equations. The two ends of the microbeam are clamped and subjected to the influence of a laser pulse with a temporal intensity profile. The analytical solutions to the physical fields are evaluated using the Laplace transform and its inversion transforms are performed numerically. The thermo-viscoelastic responses of the microbeam are calculated numerically and investigated graphically. The effect of different parameters such as viscosity, laser intensity, and the magnitude of the magnetic field are studied in detail.
Źródło:
Archives of Mechanics; 2021, 73, 1; 3-26
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A generalized thermoelastic medium subjected to pulsed laser heating via a two-temperature model
Autorzy:
Abouelregal, Ahmed E.
Zenkour, Ashraf M.
Powiązania:
https://bibliotekanauki.pl/articles/949139.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
two-temperature model
thermoelasticity
non-Gaussian laser pulse
laser intensity
Opis:
This article investigates stress and induced temperature in an isotropic, homogeneous, thermoelastic half-space using a two-temperature generalized thermoelasticity model. The bounding plane surface of the present half-space continuum is subjected to a non-Gaussian laser pulse. Laplace’s transform space is considered to deduce a closed-form solution to the problem. In addition, the inversions of Laplace’s transformations have been carried numerically to obtain field quantities in the transient state. The effects of parameters of two-temperature, laser-pulse and laser intensity are investigated. A concluding remark for the graphical forms of the derived expressions is presented.
Źródło:
Journal of Theoretical and Applied Mechanics; 2019, 57, 3; 631-639
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Control of the propagation of intense laser pulses in gas for laser plasma acceleration
Autorzy:
Giulietti, D.
Cecchetti, C. A.
Drenska, N. V.
Faccini, N.
Gatti, C.
Gatti, G.
Giulietti, A.
Gizzi, L.
Labate, L.
Levato, T.
Martellotti, S.
Pathak, N.
Valente, P.
Powiązania:
https://bibliotekanauki.pl/articles/147890.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
intense laser pulses
ultra-short laser pulse
laser plasma
plasma acceleration
Opis:
The role of the propagation mechanisms of intense and ultra-short laser pulses in gas is presented, as well as the first results of the laser plasma acceleration (LPA) tests at Frascati National Laboratories (INFN), in the frame of NTA-PLASMONX project.
Źródło:
Nukleonika; 2012, 57, 2; 221-225
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical simulation of thermal processes proceeding in a multi-layered film subjected to ultrafast laser heating
Symulacja numeryczna procesów cieplnych zachodzących w wielowarstwowych mikroobszarach poddanych działaniu ultrakrótkiego impulsu laserowego
Autorzy:
Majchrzak, E.
Mochnacki, B.
Suchy, J. S.
Powiązania:
https://bibliotekanauki.pl/articles/281751.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
microscale heat transfer
thin films
laser pulse
numerical modelling
Opis:
In the paper, the mathematical model, numerical algorithm and examples of computations concerning thermal processes proceeding in a multi-layered thin film subjected to an ultrafast laser pulse are discussed. The equations describing a course of the analysed process correspond to the dual-phase-lag model and contain both the relaxation time tau q and additionally the thermalization time tau T. At the stage of numerical simulation, the finite difference method has been used. The algorithm is based on an artificial decomposition of the domain considered, while common thermal interactions between successive layers are taken into account using conditions of heat flux and temperature continuity at points corresponding to internal boundaries (1D task has been considered).
W pracy przedstawiono model matematyczny, algorytm numeryczny i przykłady symulacji dotyczących przebiegu procesów cieplnych w wielowarstwowym mikroobszarze nagrzewanym ultraszybkim impulsem generowanym przez laser. Równanie opisujące przebieg procesu odpowiada modelowi z dwoma opóźnieniami wynikającymi z czasu relaksacji i czasu termalizacji. Na etapie obliczeń numerycznych wykorzystano metodę różnic skończonych. Algorytm bazuje na sztucznej dekompozycji obszaru wielowarstwowego, przy czym wzajemne oddziaływania między warstwami uwzględniono poprzez założenie ciągłości strumienia ciepła i pola temperatury na powierzchniach kontaktu. Biorąc pod uwagę geometrię obszaru, rozpatrywano zadanie jednowymiarowe.
Źródło:
Journal of Theoretical and Applied Mechanics; 2009, 47, 2; 383-396
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A two dimensional problem on laser pulse heating in thermoelastic microelongated solid
Autorzy:
Ailawalia, Praveen
Sachdeva, Sunil Kumar
Pathania, Devinder Singh
Powiązania:
https://bibliotekanauki.pl/articles/240726.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
laser pulse
thermoelasticity
normal mode
microelongation
impuls laserowy
termosprężystość
Opis:
In the present discussion, the plane strain deformation due to laser pulse heating in a thermoelastic microelongated solid has been discussed. The analytic expressions for displacement component, force stress, temperature distribution and micro-elongation have been derived. The effect of pulse rise time and micro-elongation on the derived components have been depicted graphically.
Źródło:
Archives of Thermodynamics; 2019, 40, 2; 69-85
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magneto-thermoelastic problem in the context of four theories under influence of laser pulse and gravity field
Autorzy:
Abo-Dahab, Sayed
Abd-Alla, Abdelmooty
Alqarni, Abdelkalk
Powiązania:
https://bibliotekanauki.pl/articles/240083.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
generalized thermoelasticity
gravity
laser pulse
magnetic field
half-space
Opis:
The paper is devoted to study the effect of gravity, magnetic field and laser pulse on the general model of the equations of generalized thermoelasticity for a homogeneous isotropic elastic half-space. The formulation is applied under four theories of generalized thermoelasticity: the coupled theory, Lord-Schulman theory, Green-Lindsay theory as well as Green-Naghdi theory. By employing normal mode analysis, the analytical expressions for the displacement components, temperature and the (mechanical and Maxwell’s) stresses distribution are obtained in the physical domain. These expressions are also calculated numerically and corresponding graphs are plotted to illustrate and compare the theoretical results. The effect of gravity, magnetic field and laser pulse are also studied and displayed graphically to show the physical meaning of the phenomena. A comparison has been made between the present results and the results obtained by the others. The results indicate that the effects of magnetic field, laser pulse and gravity field are very pronounced.
Źródło:
Archives of Thermodynamics; 2020, 41, 1; 31-66
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two-temperature theory for a heated semi-infinite solid by a pulsed laser radiation
Autorzy:
Zenkour, Ashraf M.
Abouelregal, Ahmed E.
Powiązania:
https://bibliotekanauki.pl/articles/240137.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
thermoelasticity
two-temperature
non-Gaussian laser pulse
laser intensity
phase lags
Opis:
In this paper, the two-temperature thermoelasticity model is proposed to a specific problem of a thermoelastic semi-infinite solid. The bounding plane surface of the semi-infinite solid is considered to be under a non-Gaussian laser pulse. Generalized thermoelasticity analysis with dual-phase-lags is taken into account to solve the present problem. Laplace transform and its inversion techniques are applied and an analytical solution as well as its numerical outputs of the field variables are obtained. The coupled theory and other generalized theory with one relaxation time may be derived as special cases. Comparison examples have been made to show the effect of dual-phase-lags, temperature discrepancy, laser-pulse and laser intensity parameters on all felids. An additional comparison is also made with the theory of thermoelasticity at a single temperature.
Źródło:
Archives of Thermodynamics; 2020, 41, 2; 85-101
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stabilny sterownik półprzewodnikowych laserowych diod impulsowych dla dalmierza laserowego
Stable pulsed laser diode driver for rangefinder
Autorzy:
Jakubaszek, M.
Zygmunt, M.
Muzal, M.
Młodzianko, A.
Powiązania:
https://bibliotekanauki.pl/articles/208834.pdf
Data publikacji:
2014
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
półprzewodnikowe diody laserowe
sterowniki impulsowych diod laserowych
dalmierze laserowe
pulse laser driver
pulse laser rangefinders
semiconductor pulse laser driver
Opis:
W artykule przedstawiono podstawowe metody sterowania impulsowymi diodami laserowymi stosowanymi w układach nadajników dalmierzy laserowych wraz ze wskazaniem ich wad i zalet. Na podstawie tej analizy zaproponowano układ sterownika oraz przedstawiono teoretyczne podstawy jego działania. Układ testowy został wykonany i przebadany w Instytucie Optoelektroniki Wojskowej Akademii Technicznej.
This article presents comparison of methods of driving pulse laser diodes. Based on the results of shown analyses, the new design of pulse laser diode driver, using MOSFET transistor, was developed. The driver allows stable pulse laser pumping that is required for stable pulse laser emission in high accuracy lasers’ rangefinders. Design and theory of operation of the driver is shown, as well as working parameters acquired by testing of the prototype module.
Źródło:
Biuletyn Wojskowej Akademii Technicznej; 2014, 63, 1; 43-61
1234-5865
Pojawia się w:
Biuletyn Wojskowej Akademii Technicznej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Generalized thermoelastic functionally graded half space under surface absorption of laser radiation
Autorzy:
Allam, M. N. M.
Tayel, I. M.
Powiązania:
https://bibliotekanauki.pl/articles/279539.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
laser pulse
generalized thermoelasticity
non-homogeneous medium
numerical inverse of Laplace transform
Opis:
The subject of this paper is to study the thermoelastic behavior of a functionally graded semi-infinite medium heated uniformly by a laser beam having temporally Gaussian distribution. The surface of the medium is taken as traction free. The general solution is obtained in the Laplace transform domain. The inverse of the Laplace transform is computed numerically using the Riemann-sum approximation method. The numerical results for temperature, displacement and stress are obtained and presented graphically for the generalized theory of thermo-elasticity with one relaxation time.
Źródło:
Journal of Theoretical and Applied Mechanics; 2017, 55, 1; 155-165
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Absorption coefficient along a propagated ultra-short laser pulse in the air based on Kramers–Kronig relations
Autorzy:
Malekshahi, M
Naghavi, K
Powiązania:
https://bibliotekanauki.pl/articles/173894.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
ultra-short laser pulse
refractive index
self-phase modulation
absorption coefficient
Kramers–Kronig relations
Opis:
In this manuscript, some effects such as nonlinear Kerr, stimulated Raman, and plasma generation effects lead to obtaining the nonlinear refraction index of the air along an intense ultra-short laser pulse based on one-dimensional propagation analysis. The variations in the pulse frequency by the self-phase modulation effect are investigated for achieving the functionality of the refractive index to the frequency. The mentioned functionality allows implementing Kramers–Kronig relations to measure the absorption coefficient. Results indicate that the front of the laser pulse faces a high rate of the energy loss whereas the back of the pulse experiences a gain. The implementation of Kramers–Kronig relations for a theoretical calculation of absorption coefficient variation along a laser pulse propagating in the air in which we have simultaneously taken into account the three above-mentioned effects distinguishes our work from other studies.
Źródło:
Optica Applicata; 2015, 45, 4; 501-512
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ponderomotive self-focusing of a short laser pulse under a plasma density ramp
Autorzy:
Kant, N.
Saralch, S.
Singh, H.
Powiązania:
https://bibliotekanauki.pl/articles/146636.pdf
Data publikacji:
2011
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
self-focusing
underdense plasma
plasma density ramp
ponderomotive force
short laser pulse
Gaussian beam
Opis:
The ponderomotive self-focusing of a short laser pulse in an underdense plasma under a plasma density ramp is analyzed. The pulse may acquire a minimum spot size due to the ponderomotive self-focusing. Beyond the focus, the nonlinear refraction starts weakening, and the spot size of the laser pulse increases, resulting in an oscillatory self-focusing and defocusing behavior of the beam with the propagation distance. In order to minimize the defocusing, we introduce a localized upward plasma density ramp. Due to the upward plasma density ramp, the laser beam retains a minimum spot size. Self-focusing becomes stronger with a mild ripple as the propagation distance increases. The conditions for the ponderomotive self-focusing for suitable parameters of the laser beam and the plasma are determined. The plasma density ramp of the considered type may be observed in gas jet plasma experiments.
Źródło:
Nukleonika; 2011, 56, 2; 149-153
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Irreversible blocking of polar excitations on frog sciatic nerve using semiconductor pulse laser irradiation
Autorzy:
Hirayama, Y.
Ishizuka, S.
Yamakawa, T.
Powiązania:
https://bibliotekanauki.pl/articles/385078.pdf
Data publikacji:
2009
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
irreversible blocking
semiconductor pulse Laser Irradiation
frog sciatic nerve
Opis:
The final purpose of our research is to cripple the epileptogenic focus by laser irradiation. However, the effect of laser irradiation on brain nerves is not well known. In this paper, we observed laser irradiation to the transmission of action potential of a bullfrog sciatic nerve in the experiment. In addition the marginal amplitude of laser energy is obtained. The bullfrog nerve preparations were stimulated supramaximal intensity pulse. The pulse width and the pulse interval are 1 msec and 1 sec, respectively. A semiconductor pulse laser irradiation (the wavelength, the pulse width and the frequency are 808 nm, 990 µsec and 50 Hz, respectively) was employed until when the amplitude of the action potential decreases to 10 %. The laser light was irradiated to the portion between two electrode pairs for recording. The energy of the laser is variable between 13.9- 202.5 mJ/cm2. The laser irradiator is connected to an optical fiber whose diameter is 1 mm. The action potential of the sciatic nerve is observed at 1 day after in order to confirm irreversibility. The experiment was delivered by the laser pulse, the energy of which over 32.9 mJ/cm2. The peak of action potential was decreased gradually by laser irradiation with depending on the time of irradiation. The time to blocking is reciprocally proportional to laser energy. At a day after the experiment, the action potential was not recovered. This result shows the laser irradiation give irreversible blocking to polar excitations. We observed the frog sciatic nerve is damaged by laser irradiation. The results show a possibility that the epileptogenic focus can be crippled by laser irradiation. We are going to have more experiments and obtain important laser parameters. In the future, the experiment and the result are expanded using rat brain and applied human surgery.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2009, 3, 4; 210-212
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Collinear double-pulse laser-induced breakdown spectroscopy using Nd:YAG laser generating two nanosecond pulses of regulated energy ratios
Autorzy:
Skrzeczanowski, Wojciech
Skórczakowski, Marek
Żendzian, Waldemar
Powiązania:
https://bibliotekanauki.pl/articles/27311741.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
dual-pulse laser
double-pulse LIBS
signal enhancement
self-absorption
factorial analysis
Opis:
In the paper results of single- and double-pulse LIBS (Laser-Induced Breakdown Spectroscopy) measurements in collinear geometry are described. The experiments were performed using a unique self-made Nd:YAG laser operating in the Q-switching regime, where the laser transmission losses are switched. Such a laser allowed for an easy and quick change of the operating mode (one and two pulses), free shaping of the energy ratio of the two pulses (division of the energy of a single pulse into two parts) and a smooth change of the delay time between pulses in the range from 200 ns to 10 μs. To our knowledge, such a laser was used in LIBS measurements for the first time. LIBS experiments revealed strong self-absorption depending on energy ratios carried out in the first and second laser pulse in the double-pulse mode. This was confirmed also by statistical factorial analysis of LIBS spectra. Plasma temperature and LIBS signal enhancement were measured both for energy proportions between the first and the second laser pulse and for the first-to-second-pulse delay.
Źródło:
Metrology and Measurement Systems; 2023, 30, 2; 273--287
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Femtosecond photonics for three-dimensional high density optical data storage
Autorzy:
Kawata, Y.
Tsuji, M.
Inami, W.
Powiązania:
https://bibliotekanauki.pl/articles/384323.pdf
Data publikacji:
2009
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
femtosecond pulse laser
two-photon absorption
confocal microscopy
optical memory
Opis:
We have developed a high density optical data storage by using two-photon absorption process. We have developed a multilayered medium in which photosensitive layers and transparent pressure-sensitive adhesives layer were piled up alternately. We also demonstrate the development of compact high power fiber laser as a light source of high density optical data storage system.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2009, 3, 4; 9-11
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of pulsed laser radiation on a thermoviscoelastic semi-infinite solid under two-temperature theory
Autorzy:
Othman, M. I.
Abouelregal, A. E. E.
Powiązania:
https://bibliotekanauki.pl/articles/240353.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
generalized thermo-visco-elasticity
two-temperature
Non-Gaussian laser pulse
laser intensity
phase lags
Kelvin-Voigt model
termolepkosprężystość
dwustopniowy
niegaussowski impuls laserowy
intensywność lasera
model Kelvina-Voigta
Opis:
The purpose of this paper is to study the thermoviscoelastic interactions in a homogeneous, isotropic semi-infinite solid under two-temperature theory with heat source. The Kelvin-Voigt model of linear viscoelasticity which describes the viscoelastic nature of the material is used. The bounding plane surface of the medium is subjected to a non-Gaussian laser pulse. The generalized thermoelasticity theory with dual phase lags model is used to solve this problem. Laplace transform technique is used to obtain the general solution for a suitable set of boundary conditions. Some comparisons have been shown in figures to estimate the effects of the phase lags, viscosity, temperature discrepancy, laser-pulse and the laser intensity parameters on all the studied fields. A comparison was also made with the results obtained in the case of one temperature thermoelasticity theory.
Źródło:
Archives of Thermodynamics; 2017, 38, 3; 77-99
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł

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