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Effects of Laser Remelting at Cryogenic Conditions on Microstructure and Wear Resistance of the Ti6Al4V Alloy Applied in Medicine
PublikacjaThe titanium and its alloys can be subjected to surface treatment, including laser treatment. In this work a new laser treatment at cryogenic conditions of Ti6Al4V alloy has been described. The work has been aimed at establishing whether such surface treatment could be suitable for implants working under wear in biological corrosive environment. The remelting has been made with the use of CO2 continuous work laser at laser power...
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Optimization of the femtosecond laser impulse for excitation and the Spin-Orbit mediated dissociation in the NaRb Dimer
PublikacjaWe study the dynamics of multiple coupled states under the influence of an arbitrary time-dependent external field to investigate the femtosecond laser-driven excitation and the spin-orbit mediated dissociation in the NaRb dimer. In this process, the dimer is excited from the ground triplet state 1^3Sigma+ to the 1^3Pi state using the femtosecond laser impulse and the spin-orbit coupling between the 1^3Pi and 2^1Sigma+ states results...
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Two-photon perimetry utilizing picosecond laser
PublikacjaAge-related impairments are becoming more and more severe for aging societies. The sensory organ diseases are particularly troublesome as they exclude seniors from their everyday activity. Therefore, maintaining good quality eyesight is essential for normal functioning. New medical therapies help restrain age-related changes, but still, monitoring is essential to the treatment process. Humans do not have the natural ability to...
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Preparation of porous TiO2 films by means of pulsed laser deposition for photocatalytic applications
PublikacjaIn this work the preparation and structure properties of porous thin films of TiO2 were investigated. The films were produced by means of the pulsed laser deposition technique using laser pulses at 266nm (10Hz) and at fluencies of 1-3.5J/cm2. The process was performed in vacuum using O2 buffer gas and films were deposited on the SiO2 glass or Si substrate. X-ray diffraction (XRD) and Raman analysis of the structure and chemical...
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Laser-assisted modification of titanium dioxide nanotubes in a tilted mode as surface modification and patterning strategy
PublikacjaElectrochemical anodization is regarded as a facile and easily scalable fabrication method of titania nanotubes (TiO2NTs). However, due to the extended duration of calcination and further modifications, much faster alternatives are highly required. As a response to growing interest in laser modification of nanotube arrays, a comprehensive investigation of pulsed-laser irradiation and its effect onto TiO2NT properties has been carried out....
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Anodic titania nanotubes decorated with gold nanoparticles produced by laser-induced dewetting of thin metallic films
PublikacjaHerein, we combine titania layers with gold species in a laser-supported process and report a substantial change of properties of the resulting heterostructures depending on the major processing parameters. Electrodes were fabricated via an anodisation process complemented with calcination to ensure a crystalline phase, and followed by magnetron sputtering of metallic films. The obtained TiO2 nanotubes with deposited thin (5, 10...
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Prosthetic Elements Made of the Ti-13Zr-13Nb Alloy by Selective Laser Melting
PublikacjaThe fabrication of the prosthetic foundations and bridges from the Ti-13Zr-13Nb alloy is described. The process was started from CAD/CAM design of 3D models of the foundations based on scanning of patient`s mouth. Next, 3D models were transformed into *.stl files for the manufacturing stage and then the manufacturing process by means of the selective laser melting with the SLM Realizer 100 equipment was made. The intrinsic structure...
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The In-Depth Studies of Pulsed UV Laser-Modified TiO2 Nanotubes: The Influence of Geometry, Crystallinity, and Processing Parameters
PublikacjaThe laser processing of the titania nanotubes has been investigated in terms of morphology, structure, and optical properties of the obtained material. The length of the nanotubes and crystallinity, as well as the atmosphere of the laser treatment, were taken into account. The degree of changes of the initial geometry of nanotubes were checked by means of scanning electron microscopy, which visualizes both the surface and the cross-section....
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Effect of plasma sprayed and laser re-melted Al2O3 coatings on hardness and wear properties of stainless steel
PublikacjaCommercially available austenic stainless steel substrate was coated with commercially available, raw Al2O3 powder applied by means of plasma spraying method and then re-melted with CO2 laser beam of various parameters. Tribological and mechanical properties of the 120 J/mm and 160 J/mm laser re-melted coatings were compared with the tribological and mechanical properties of the “as-sprayed” coating. The influence of the laser...
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Combined Close Range Photogrammetry and Terrestrial Laser Scanning for Ship Hull Modelling
PublikacjaThe paper addresses the fields of combined close-range photogrammetry and terrestrial laser scanning in the light of ship modelling. The authors pointed out precision and measurement accuracy due to their possible complex application for ship hulls inventories. Due to prescribed vitality of every ship structure, it is crucial to prepare documentation to support the vessel processes. The presented methods are directed, combined...
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Seasonal changes in the concentrations of airborne bacteria emitted from a large wastewater treatment plant
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Influence of laser processing of the low alloy medium carbon structural steel on the development of the fatigue crack
PublikacjaThe paper contains the results of the structural analysis, hardness tests and fatigue tests conducted for the medium carbon structural steel with low content of Cr and Ni after its processing with CO2 laser beam. Pre-cracks were made in the round compact tension (RCT) specimen used for fatigue test. Next, four paths, parallel to each other, were melted on both sides of the samples using a laser beam. The paths were perpendicular...
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Mechanical Properties and Wear Susceptibility Determined by Nanoindentation Technique of Ti13Nb13Zr Titanium Alloy after “Direct Laser Writing”
PublikacjaLaser treatment has often been applied to rebuild the surface layer of titanium and its alloys destined for long-term implants. Such treatment has always been associated with forming melted and re-solidified thin surface layers. The process parameters of such laser treatment can be different, including the patterning of a surface by so-called direct writing. In this research, pulse laser treatment was performed on the Ti13Nb13Zr...
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Organic semiconductor rubrene thin films deposited by pulsed laser evaporation of solidified solutions
PublikacjaOrganic semiconductor rubrene (C42H28) belongs to most preferred spintronic materials because of the high charge carrier mobility up to 40 cm2(V·s)-1. However, the fabrication of a defect-free, polycrystalline rubrene for spintronic applications represents a difficult task. We report preparation and properties of rubrene thin films deposited by pulsed laser evaporation of solidified solutions. Samples of rubrene dissolved in aromatic...
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THE METHOD OF MEASURING THE MEMBRANE COVER GEOMETRY USING LASER SCANNING AND SYNCHRONOUS PHOTOGRAMMETRY
PublikacjaThe authors present the experience and results of field studies carried out at the technical acceptance of Forest Opera (name in Polish: Opera Leśna) in Sopot (Poland). An unusual design of covering made in the form of “Sheerfill I” technical fabric membrane required spanned in the form of sails, required the use of terrestrial laser scanning. Such approach allowed for the fast and accurate record of the surface of individual panels...
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Modes of Failure Analysis in Reinforced Concrete Beam Using Laser Scanning and Synchro-Photogrammetry
PublikacjaThe following paper reveal the limitations and possibilities of terrestrial laser scanning technology adaptation in diagnostics of reinforced concrete beams. In this paper, authors present potential spectrum of TLS use in modes of failure analysis of R-C beams and determines under which conditions the laser technologies might be applied. Research was carried out at the Regional Laboratory of Structural Engineering at Gdansk University...
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Laser Beam as a Precision Tool to Increase Fatigue Resistance in an Eyelet of Undercarriage Drag Strut
PublikacjaThe article contains the results of tests on a laser-processed eyelet of undercarriage drag strut to increase its fatigue strength. Laser processing concentrated on both sides around the hole of eye for connecting the undercarriage drag strut caused that the material in this area withstood more than twice the number of load cycles established for this material. In order to determine the reasons for the increase in fatigue strength,...
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Advancements in the Additive Manufacturing of Magnesium and Aluminum Alloys through Laser-Based Approach
PublikacjaComplex structures can now be manufactured easily utilizing AM technologies to meet the pre-requisite objectives such as reduced part numbers, greater functionality, and lightweight, among others. Polymers, metals, and ceramics are the few materials that can be used in AM technology, but metallic materials (Magnesium and Aluminum) are attracting more attention from the research and industrial point of view. Understanding the role...
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Problems of analysis of axially loaded steel behavior under laser welded panel
PublikacjaWprowadzanie do praktyki nowych rozwiązań konstrukcyjnych wymaga posiadania danych wejściowych do procesu modelowania ich zachowania. Takim nowym elementem jest stalowy, spawany laserowo panel typu sandwich. W pracy pokazano wy-brane problemy towarzyszące modelowaniu zachowań takiej struktury. Pokazano podstawy teoretyczne wyznaczania sztyw-ności panelu a następnie omówiono wyniki badań wyboczenio-wych serii modeli o zmiennej geometrii.
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Laser technology 2012
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Wear Resistance Enhancement of Al6061 Alloy Surface Layer by Laser Dispersed Carbide Powders
PublikacjaIn this paper, results of the experimental study on improving wear resistance in sliding friction of Al-based alloy are presented. The technique used involves the formation of a metal matrix composite (MMC) in the alloy surface layer by laser dispersion of carbide powders such as WC, TiC and SiC. For WC and TiC MMC surface coatings fabricated under conditions typical for most of the technologically relevant solid-state lasers (wavelength...
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Determinants of the surface quality, density and dimensional correctness in selective laser melting of the Ti-13Zr-13Nb alloy
PublikacjaSelective laser melting is widely used for custom-designed elements. Successful manufacturing depends on laser treatment parameters and material features. This research aimed to determine the effects of laser power, scan time and hatch distance on surface quality, relative density and dimensional precision for cuboids made of the Ti-13Zr-13Nb alloy. The influence of energy density, energy flux and pre-heating was seen to be decisive...
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The Effect of Laser Re-Solidification on Microstructure and Photo-Electrochemical Properties of Fe-Decorated TiO2 Nanotubes
PublikacjaFossil fuels became increasingly unpleasant energy source due to their negative impact on the environment; thus, attractiveness of renewable, and especially solar energy, is growing worldwide. Among others, the research is focused on smart combination of simple compounds towards formation of the photoactive materials. Following that, our work concerns the optimized manipulation of laser light coupled with the iron sputtering to...
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The interaction of the pulsed laser irradiation with titania nanotubes - Theoretical studies on the thermal effect
PublikacjaThis paper reports temperature dispersion simulations of titania nanotubes irradiated by the 355 nm, pulsed, nanosecond laser. The modelling with the use of Finite Elements Method concerns titania nanotubes of the length and the wall thickness in the range of 0.5–2 μm and 5–20 nm, respectively. The uniqueness of the morphology was preserved by ensuring the wall thickness variation along the height of the tube, which was determined...
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Heat Transfer of the Multicolor-Laser-Sources-Irradiated Nanoparticles in Reference to Thermal Processes
PublikacjaUnlike the standard materials, metallic nanoparticles offer enhancing the heat convertion rate which implies the maximum and average temperature boost significantly in the considered system. The work’s purpose is to examine heat transfer in the metallic nanoparticles which have been deposited on a glassy substrate, enabling the nanostructures thermoablation. Furthermore, the functionalized substrate is irradiated with multicolor-laser-sources,...
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BACTERIAL INACTIVATION VIA LASER-DRIVEN GOLD NANOPARTICLE HEATING: SIMULATION AND ANALYSIS
PublikacjaThis study utilizes CFD technique to simulate the inactivation of E. coli bacteria within a microfluidic chamber, employing gold nanoparticles irradiated by a laser beam. Employing a single-phase model, the presence of bacteria is considered by treating thermal properties in the governing equations as effective, combining those of water and bacteria using established correlations from scientific literature. The conversion of light...
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Laser stimulated second and third harmonic optical effects in F: SnO2 nanostructures grown via chemical synthetic route
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The effect of laser on metal surfaces for multidisciplinary usage in material and thermal engineering
PublikacjaThe subject of heat transfer and cooling systems is still a matter of contention in many different fields of science and industry. Infrigidation is much more difficult than warming, and so, much more needed in more and more different devices, starting from massive industrial machinery and air conditioning in commercial buildings, up to micro and nano-surgery tools. In fact, the size of many cooling systems is still a problem. It...
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The phase composition of the surface layer of laser melted Ti-6Al-4V bioalloy
PublikacjaZastosowanie metody obróbki laserowej stopów Ti zwiekszyły twardość i odporność stopu na korozję. Jednakże uzyskane warstwy były stosunkowo cieńkie. W pracy zastosowano laser o dużej mocy dla stopu schłodzonego w ciekłym azocie, aby uzyskać grubszą warstwę, która w strefie zewnętrznej złożona będzie z tlenku i azotku tytanu, ważnych faz w biostopach.
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Analysis of the Surface Stereometry of Alloyed Austenitic Steel after Fibre Laser Cutting using Confocal Microscopy
PublikacjaThe paper extends the concept of cut edge quality and examines the fibre laser cutting process. A Prima Power Platino Fiber Evo device with a reference speed (RS) of 3500 mm/min was used for laser cutting. In order to analyse the influence of the laser cutting speed on the cut edge quality of X5CrNi18-10 stainless steel sheets, macroscopic studies were conducted on a stereoscopic microscope and surface stereometry on a confocal...
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Effect of pulse laser treatment at different process variables on mechanical behavior of carbon nanotubes electrophoretically deposited on titanium alloy
PublikacjaPurpose: Titanium and its alloys are widely used as biomaterials for long-term implants, but they are usually surface-modified due to their weak bioactivity and wear resistance. Laser processing was used to modify the surface layer, and elemental carbon was a component of the deposited coatings. This research aims to use a combination of both methods based on preliminary electrophoretic deposition of multi-wall carbon nanotubes...
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Review on robust laser light interaction with titania – Patterning, crystallisation and ablation processes
PublikacjaTitanium dioxide is regarded as a very promising semiconducting material that is widely applied in many everyday-use products, devices, and processes. In general, those applications can be divided into energy or environmental categories, where a high conversion rate, and energy and power density are of particular interest. Therefore, many efforts are being put towards the elaboration of novel production routes, and improving the...
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Review of Shoreline Extraction Methods from Aerial Laser Scanning
PublikacjaAutonomous technologies are increasingly used in various areas of science. The use of unmanned vehicles for hydrographic surveys in shallow coastal areas requires accurate estimation of shoreline position. This is a nontrivial task, which can be performed using a wide range of sensors and methods. The aim of the publication is to review shoreline extraction methods based solely on data from aerial laser scanning (ALS). This narrative...
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Mean Shift Segmentation Assessment for Individual Forest Tree Delineation from Airborne Lidar Data
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Experimental Evaluation of ND: YAG Laser Parameters and Sample Preparation Methods for Texturing Thin AISI 316L Steel Samples
PublikacjaIn mechanical and material engineering, the effect of laser texturing depends on many factors besides device specification, primarily the properties of the materials being processed, and, secondly, the preparation of the sample. Laser texturing of thin (<5 mm) samples is mostly performed utilizing short-pulse lasers, but depending on the power of the laser beam, the process can also be performed by using continuous operation lasers....
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Preparation of platinum modified titanium dioxide nanoparticles with the use of laser ablation in water
PublikacjaWe report on the preparation method of nanocrystalline titanium dioxide modified with platinum by using nanosecond laser ablation in liquid (LAL). Titania in the form of anatase crystals has been prepared in a two-stage process. Initially, irradiation by laser beam of a titanium metal plate fixed in a glass container filled with deionized water was conducted. After that, the ablation process was continued, with the use of a platinum...
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A new approach of coastal cliff monitoring using Mobile Laser Scanning
PublikacjaThe article proposes a new approach of coastal cliff monitoring which bases on a new comprehensive monitoring system, being a combination of mobile scanning from the sea with the geotechnical stability analysis. Mobile laser scanning is an innovative solution for 3D data collection which allows the monitored object geometry to be precisely measured, thus providing opportunities for series of analyses contributing to the development...
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Model of optical phantoms thermal response upon irradiation with 975 nm dermatological laser
PublikacjaWe have developed a numerical model describing the optical and thermal behavior of optical tissue phantoms upon laser irradiation. According to our previous studies, the phantoms can be used as substitute of real skin from the optical, as well as thermal point of view. However, the thermal parameters are not entirely similar to those of real tissues thus there is a need to develop mathematical model, describing the thermal and...
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Kinetics of molecular decomposition under irradiation of gold nanoparticles with nanosecond laser pulses—A 5-Bromouracil case study
PublikacjaABSTRACT Laser illuminated gold nanoparticles (AuNPs) efficiently absorb light and heat up the surrounding medium, leading to versatile applications ranging from plasmonic catalysis to cancer photothermal therapy. Therefore, an in-depth understanding of the thermal, optical, and electron induced reaction pathways is required. Here, the electrophilic DNA nucleobase analog 5-Bromouracil (BrU) has been used as a model compound to...
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Impact of laser beam welding on mechanical behaviour of 2.25Cr–1Mo (P22) steel
PublikacjaThe use of welding processes in the manufacturing and repair of structures intended for the energy industry plays a key role in the guarantee of a continuous supply of fossil fuels, which is the basic condition for ensuring energy security. A square butt joint of 10 mm thick plate of 2.25Cr–1Mo (P22) steel was fabricated by autogenous laser beam welding process and then post-weld heat treatment (PWHT) for two sets of process parameters...
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Ordered titania nanotubes layer selectively annealed by laser beam for high contrast electrochromic switching
PublikacjaThe phase conversion from amorphous into crystalline one in the selected area of as-anodized titania nanotubes was achieved via laser treatment. The optimized processing parameters enable fast, one-minute crystallization of titania within an area limited by a shadow mask and without any morphology damage of ordered TiO2 tubular film. The laser annealed titania nanotubes could be easily overgrown by a conducting polymer without...
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Satellite Laser Ranging technique as a tool for the determination of the Schwarzschild, de Sitter and Lense-Thirring effects
PublikacjaSatellite Laser Ranging (SLR) is a modern technique used in various research areas and applications related to geodesy and geodynamics. It is commonly used for tasks such as establishing the International Terrestrial Reference Frame (ITRF), monitoring Earth Orientation Parameters (EOP), determining the geocenter, measuring fundamental physical constants, calibrating microwave tracking techniques, conducting time transfer experiments,...
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Synthesis, structural characterization, and thermal properties of Ca‐ and La‐doped soda‐lime glasses by laser melting
PublikacjaLaser melting techniques have been used in the preparation of unconventional glass compositions with high melting temperatures. Thus, we wanted to test the feasibility of using a CO2 laser in the preparation of nitrogen-rich oxynitride glasses and nitride silicate glasses. Melting from oxides and metallic raw materials, we wanted to study first glass formation and possible evaporation losses of the glass components. Two glass series...
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Femtosecond laser ablated trench array for improving performance of commercial solid oxide cell
PublikacjaThe performance of electrode-supported solid oxide cells (SOCs) is limited adversely by gas diffusion impedance in thick and porous support. This work focuses on the improvement of gas transport properties of commercial Ni-YSZ anode-supported SOFC by femtosecond laser-based micromachining where micro-holes of identical depth but different hole separations pitches with minimal heated affected zones were imposed. The polarization...
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Laser Dissimilar Welding of AISI 430F and AISI 304 Stainless Steels
PublikacjaA dissimilar autogenous laser welded joint of AISI 430F (X12CrMoS17) martensitic stainless steel and AISI 304 (X5CrNi18-10) austenitic stainless steel was manufactured. The welded joint was examined by non-destructive visual testing and destructive testing by macro- and microscopic examination and hardness measurements. With reference to the ISO 13919-1 standard the welded joint was characterized by C level, due to the gas pores...
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In vivo imaging of the human eye using a two-photon excited fluorescence scanning laser ophthalmoscope
PublikacjaBACKGROUND. Noninvasive assessment of metabolic processes that sustain regeneration of human retinal visual pigments (visual cycle) is essential to improve ophthalmic diagnostics and to accelerate development of new treatments to counter retinal diseases. Fluorescent vitamin A derivatives, which are the chemical intermediates of these processes, are highly sensitive to UV light; thus, safe analyses of these processes in humans...
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Development of laser technology in Poland
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Laser Technology and Applications 2012
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InGaN trapered laser diodes
PublikacjaW pracy zaprezentowano rezultaty badan nad diodami laserowymi InGaN ze zwężającym się kanałem. Kąty kanałów zmieniane były w zakresie 2 -5 stopni, jak również zmieniana była długość kanału. Wykazano, że w przypadku optymalnych parametrów, parametr M2 (M kwadrat) opisujący odtępstwa wiązki od krzywej Gaussa, wynosił 2.1 przy mocy optycznej 200 mW.
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Comparison of strain results at a laser weld notch obtained by numerical calculations and experimental measurements
PublikacjaIn the development of ship structures applying new materials and it’s purposeful placement play an important role. During the last years, especially in a construction of ro-ro type vessels, the usage of novel sandwich structures in cargo decks is profitable. Steel sandwich panel is an innovative solution which at a todays state of development can be used for the construction of any members not taking part in a global bending of...