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Search results for: LASER MICROMACHINING
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Surface Property Modification of Collagen, Hyaluronic Acid, and Chitosan Films with the Neodymium Laser
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Chemical, thermal and laser processes in recycling of photovoltaic silicon solar cells and modules
PublicationIn recent years, photovoltaic power generation systems have been gaining unprecedented attention as an environmentally beneficial method to solve the energy problem. From the economic point of view the pure silicon, which can be recapture from the used cells, is the most important material due to its cost and shortage. In the paper selected methods of used or damaged module and cells recycling and experimental results are presented....
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Laser Investigations of Flow Patterns in Electrostatic Precipitators and Non Thermal Plasma Reactors
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Engineering Au nanoparticle arrays on SiO2 glass by pulsed UV laser irradiation
PublicationWe study semi-regular arrays of Au nanoparticles (NP) obtained via UV laser irradiation of thin Au films on glass substrate. The NP structures are prepared from films of a thickness up to 60 nm produced by discharge sputtering or pulsed laser deposition, and annealed by nanosecond laser pulses at 266 or 308 nm, respectively, at fluencies in the range of 60-410 mJ/cm2. For the rare- and close-packed NP structures, consistent description...
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Preparation of porous TiO2 films by means of pulsed laser deposition for photocatalytic applications
PublicationIn 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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Influence of laser remelting at cryogenic conditions on corrosion resistance of non-ferrous alloys
PublicationCelem nadtapiania laserowego elementów wytwarzanych z stopów aluminium, miedzi i tytanu jest uzyskanie wysokiej twadrości i odporności na korozję dla wydłużenia okresu ich eksploatacji w rezultacie ich szybkiej krystalizacji. Końcowa mikrostruktura, skład fazowy i właściwości wymienionych stopów zależą od parametrów obróbki laserowej oraz budowy wykresów równowagi fazowej. W artykule przedstawiono wpływ laserowego nadtapiania...
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Properties of surface layers of titanium alloy Ti6Al4V after laser melting processes
PublicationThe article presents the investigation results of titanium alloy Ti6Al4V surface layer after laser melting process. The process of laser melting was performed using Nd-YAG laser. The evaluation of structure of the alloy as well as hardness and chemical composition was performed. It was shown that laser melting changes the structure and properties of titanium alloy Ti6Al4V and process parameters as scanning speed affects the thickness...
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Surface texture formation in precision machining of direct laser deposited tungsten carbide
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Application of high pressure laser flash photolysis in studies on selected hemoprotein reactions
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Surface roughness analysis after machining of direct laser deposited tungsten carbide
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Laser induced elastooptics in novel Bi2O3, and Pr2O3 doped tellurite rich glasses
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The possibility of an use of laser treatment to improve the behaviour of the Ti-6Al-4V alloy
PublicationPrezentowana praca miała na celu stworzenie warunków ultraszybkiego chłodzenia przetopionej warstwy w obecności azotu tak, aby otrzymać twardą i gruba warstwę wierzchnią na stopie Ti-6Al-4V , najczęściej używanm stopie Ti, zawierającą struktury martenzytu i azotku tytanu.
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Problems of analysis of axially loaded steel behavior under laser welded panel
PublicationWprowadzanie 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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Prosthetic Elements Made of the Ti-13Zr-13Nb Alloy by Selective Laser Melting
PublicationThe 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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Combined Close Range Photogrammetry and Terrestrial Laser Scanning for Ship Hull Modelling
PublicationThe 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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Influence of Parameters of Laser Beam Welding on Structure of 2205 Duplex Stainless Steel
PublicationLaser welding is used in modern industry, having many advantages comparing to traditional welding technologies. Nowadays, industry sectors such as shipbuilding, automotive and aviation can’t be imagined without laser processing technologies. Possibility of increase of welded joint properties, autogenous welding and high level of process automation makes the technology of laser welding perspective part of the industry. Physical...
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Stability Assessment of Coastal Cliffs Incorporating Laser Scanning Technology and a Numerical Analysis
PublicationWe investigated the cli coast in Jastrzebia Gora, Poland. The measurements that were taken between 2014 and 2018 by applying terrestrial, mobile, and airborne laser scanning describe a huge geometric modification involving dislocations in a 2.5 m range. Dierential maps and a volumetric change analysis made it possible to identify the most deformed cli’s location. Part of the monitoring of coastal change involved the measurement...
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STUDIES ON THE USE OF TERRESTRIAL LASER SCANNING IN THE MAINTENANCE OF BUILDINGS BELONGING TO THE CULTURAL HERITAGE
PublicationWithin the frames of the use of terrestrial laser scanning we find numerous examples of registration of building facilities, including also historical and valuable in their culture. In the case presented in this paper, at the root of the problem there is a preservation of the historic blacksmith’s forge located in Gdansk Orunia. The facility dating from the early nineteenth century was intended to repair involving the complete...
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THE METHOD OF MEASURING THE MEMBRANE COVER GEOMETRY USING LASER SCANNING AND SYNCHRONOUS PHOTOGRAMMETRY
PublicationThe 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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THE METHOD OF ANALYSIS OF DAMAGE REINFORCED CONCRETE BEAMS USING TERRESTRIAL LASER SCANNING
PublicationThe authors present an analysis of the possibility to assess deformations and mode of failure of R-C beams using terrestrial laser scanning. As part of experiments carried out at the Regional Laboratory of Construction (at Gdansk University of Technology), reinforced concrete beams were subjected to destruction by bending and by shear. The process of press impact on the reinforced concrete beam was recorded using terrestrial laser...
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Studies on the use of terrestrial laser scanning in the maintenance of buildings belonging to the cultural heritage
PublicationWithin the frames of the use of terrestrial laser scanning we find numerous examples of registration of building facilities, including also historical and valuable in their culture. In the case presented in this paper, at the root of the problem there is a preservation of the historic blacksmith's forge located in Gdansk Orunia. The facility dating from the early nineteenth century was intended to repair involving the complete...
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APPLYING RANSAC ALGORITHM FOR FITTING SCANNING STRIPS FROM AIRBORNE LASER SCANNING
PublicationDuring the development of the data acquired by airborne laser scanning the important issue is the fitting and georeferencing of ALS point clouds by means of the tie surfaces and the reference planes. The process of scanning strips adjustment is based on mutual integration of point clouds (scanning strips) and their adaptation to the reference planes.In simultaneous adjustment all strips are combined into one geometrically coherent...
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Application of the laser diode with central wavelength 975 nm for the therapy of neurofibroma and hemangiomas
PublicationThis paper presents newly developed dermatological laser (with central wavelength 975 nm) for application in therapies requiring deep penetration of tissue, e.g. cutaneous (dermal) neurofibroma (Recklinghausen disease) and hemangiomas. This laser can work either in pulse or continues wave mode. Laser radiation is transmitted toward the application region by optical fiber with a diameter of 0.6 mm. The compact design of the laser...
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Effect of Laser Treatment on Intrinsic Mechanical Stresses in Titanium and Some of Its Alloys
PublicationLaser surface treatment conducted at different power levels is an option to modify titanium bone implants to produce nano- and microtopography. However, such processing can lead to excess mechanical stress within the surface layer. This research aims to calculate the level of such residual stresses after the surface processing of Ti grade IV, Ti15Mo, and Ti6Al7Nb alloys with an Nd:YAG laser. Light and scanning electron microscopies...
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Effects of preheating on laser beam–welded NSSC 2120 lean duplex steel
PublicationDuplex stainless steels show sustainable alternative for the conventional austenitic grades, with higher strength, higher resistance against stress corrosion cracking, and lower purchase cost. Thus, duplex stainless steel gains more attention in construction, oil and gas, and chemical industries. Among duplex stainless steels, low nickel and low molybdenum alloyed lean duplex stainless steel are a cost-efective substitution of...
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Cavitation erosion of chromium-manganese and chromium-cobalt coatings processed by laser beam
PublicationPrzedstawiono wyniki badań erozji kawitacyjnej napoin wykonanych za pomocą elektrod chromowo-manganowych i chromowo-niklowych oraz obrobionych wiązką lasera CO2 o mocy 1000 W. Próbki poddawano obciążeniom kawitacyjnym na stanowisku z wirującą tarczą. Zaobserwowano wzrost odporności kawitacyjnej napoin, w których dokonano przetopienia ich powierzchni promieniowaniem lasera.
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Investigations of Energy Conversion and Surface Effect for Laser-Illuminated Gold Nanorod Platforms
PublicationAchieving a quick temperature increase is a burning issue for biophysical applications, like germ inactivation and tumor ablation, and for energy performances, like solar collectors and steam generators. Based on the plasmon resonance phenomenon, noble metallic nanoparticles have emerged as promising weapons due to their very high biocompatibility, optical properties, and high surface-to-volume ratio, increasing energy conversion...
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Relationship between cavitation resistance of laser produced alloys and their ability to work hardening
PublicationBadano odporność kawitacyjną laserowo wytworzonych stopów na stalach konstrukcyjnych i ich związek ze zdolnością do umacniania się pod wpływem działania obciążeń kawitacyjnych. Wykazano, że mikrotwardość powierzchni wykazuje monotoniczną zależność z odpornością kawitacyjną i zdolnością do umacniania.
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Morphology and corrosion characteristics of laser surface remelted Al-Sialloy at cryogenic conditions
PublicationPrzedstawiono koncepcję obróbki laserowej stopu Al-Si w warunkach kriogenicznych. Określono jej wpływ na lokalny skład chemiczny oraz mikrostrukturę i właściwości korozyjne wymienionego stopu. Stwierdzono znaczącą poprawę właściwości korozyjnych w 0,01 M H2SO4.
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Cavitation erosion of some alloys manufactured on steel and iron surfaces by laser beam.
PublicationPrzedstawiono badania odporności kawitacyjnej stali węglowej 45 odpornej na korozję 2H13 i technicznego żelaza po ich obróbce laserowej. Warstwę wierzchnią wybranych stali wzbogacono w różne pierwiastki stopowe i badano odporność kawitacyjną na stanowisku z wirującą tarczą. Stwierdzono niską odporność kawitacyjną dla warstw o obniżonej zdolności do utwardzania pod wpływem obciążeń kawitacyjnych oraz silną zależność odporności...
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Corrosion characteristics of the AL-Si alloy after laser treatment at cryogenic conditions
PublicationOmówiono wpływ laserowego powierzchniowego przetapiania stopu Al-Si w warunkach kriogenicznych na jego mikrostrukturę i właściwości użytkowe. W wyniku badań korozyjnych stwierdzono zwiększenie odporności na korozję stopu Al-Siw 0,01 M roztworze H2SO4.
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Tunable semiconductor laser application for interferometric optical fibersensors.Optical and Electronic Sensors V.
PublicationW pracy przedstawiono metody stabilizacji punktu pracy światłowodowych sensorów interferometrycznych. W metodach tych wykorzystuje się układy regulacji sterujące długością fali przestrajalnego lasera półprzewodnikowego. Przedstawiono tryby pracy układów regulacji oraz problemy związane z ich projektowaniem i realizacją. Przeanalizowano ograniczenia sensorów wykorzystujących powyższe układy. Dokonano weryfikacji eksperymentalnej...
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Influence of laser beam machining on the cavitation resistance of Fe-Cr-Co clad.
PublicationW pracy przedstawiono wpływ laserowego nagrzewania bezzmiany stanu skupienia i laserowego przetapiania napoin ze stopu Fe-Cr-Co na ich odporność kawitacyjną. Badania kawitacyjne prowadzono na stanowisku z wirującą tarczą. Plastyczne odkształcenia powierzchni określano za pomocą analizy obrazów erodowanych powierzchni. Uzyskane rezultaty wskazują, że laserowo obrabiane powierzchnie miały różną podatność do plastycznego odkształcania...
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Colorimetric study of the post-processing effect due to pulsed laser cleaning of paper.
PublicationW artykule przedstawiono wyniki badań procesu oczyszczania papieru implulsami laserowymi o różnej długości fali. Oceny dokonywano na podstawie pomierzonych wartości parametrów kolorymetrycznych. Badania obejmowały próbki papieru o różnym wieku.
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Cavitation erosion of some laser-produced iron-base corrosion-resistance alloys
PublicationW pracy przedstawiono badania kawitacyjne stali C45, X20Cr13 oraz X5CrNi18-10 po laserowym stopowaniu ich warstwy wierzchniej proszkami Mn, Cr, Ni, Si, Ti, Co, Al, Mo, B. Badania kawitacyjne prowadzono na stanowisku z wirującą tarczą. Zniszczenia powierzchni w okresie inkubacji oceniano metodą optyczną. Przedstawiono związek pomiędzy uzyskaną mikrostrukturą obrabianej warstwy i jej odpornością kawitacyjną.
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Relationship between microstructure of laser alloyed C45 steel and its cavitation resistance.
PublicationW pracy przedstawiono badania wpływu laserowo kształtowanej mikrostruktury na stali C45 po stopowniu różnymi kompozycjami proszków metali na własności kawitacyjne warstwy wierzchniej. Badania prowadzono w początkowym stadium erozji kawitacyjnej. Stwierdzono, że lepszą odporność kawitacyjną osiąga się gdy mikrostruktura jest podatna do umacniania odkształceniowego np. w obecności pewnej ilości austenitu w strukturze.
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Relationship between microstructure of laser alloyed of C45 steel and its cavitation resistance.
PublicationPrzedstawiono badania odporności kawitacyjnej stali C45 po laserowym stopowaniu jej powierzchni proszkami Mn., Ni, Cr, Nb, Mo, Co. Stwierdzono, że warstwa wierzchnia posiada wyższą odporność kawitacyjną jeśli w jej mikrostrukturze występuje pewna ilość austenitu zwiększająca podatność do wzmacniania odkształceniowego.
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Qiangjiguang Yu Lizishu/High Power Laser and Particle Beams
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Wojciech Litwin dr hab. inż.
People1992÷1996 - study on Mechanical Department at Gdansk University of Technology1996 – employed in the Faculty of Ocean Engineering and Ship Technology at the Gdansk University of Technology2004 – PhD2014 – habilitation2016 - vice dean for science at Faculty of Ocean Engineering2020 - dean of the Faculty of Ocean Engineering2021 - head of Institute of Naval Architecture He participated in a number of designing and research programs...
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Characteristics of La0.8Sr0.2Ga0.8Mg0.2O3-delta -supported micro-tubular solid oxide fuel cells with bi-layer and tri-layer electrolytes
PublicationIn this study, La0.8Sr0.2Ga0.8Mg0.2O3−δ (LSGM)-supported micro tubular solid oxide fuel cells (T-SOFCs) with two different configurations, one containing an LSGM–Ce0.6La0.4O2−δ (LDC) bi-layer electrolyte (Cell A) and one containing an LDC–LSGM–LDC tri-layer electrolyte (Cell B), were fabricated using extrusion and dip-coating. After optimizing the paste formulation for extrusion, the flexural strength of the dense and uniform LSGM...
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Synthesis of three layer NaxCoO2 (x=0.3, 0.5, 0.6, 0.75, 1.0) and superconductivity in three layer Na0.3CoO2 * 1.3H2O
PublicationDyskutowana jest synteza trójwarstwowego związku sodowo-kobaltowego tlenku NaxCoO2. Związek o zawartości sodu x=0.3 może zostać uwodniony i staje się nadprzewodnikiem z Tc=4.3K. Powierzchnia 3 warstwowego związku charakteryzuje się trójkątną morfologią, podczas gdy dwuwarstwowy związek Na0.7CoO2 - heksagonalną morfologią.
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Influence of Surface Laser Treatment on Mechanical Properties and Residual Stresses of Titanium and its Alloys
PublicationSurface modification of the titanium and its alloys used in implantology with a long-pulse laser can change the surface topography, but it also leads to changes in the stress sign and magnitude in the resulting subsurface layer. The presented research was aimed at evaluating the state of stress after laser remelting with the Nd:YAG laser of pre-etched titanium alloys Ti6Al4V and Ti13Nb13Zr and pure titanium. The obtained surface...
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High performance filtering for big datasets from Airborne Laser Scanning with CUDA technology
PublicationThere are many studies on the problems of processing big datasets provided by Airborne Laser Scanning (ALS). The processing of point clouds is often executed in stages or on the fragments of the measurement set. Therefore, solutions that enable the processing of the entire cloud at the same time in a simple, fast, efficient way are the subject of many researches. In this paper, authors propose to use General-Purpose computation...
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Autogenous Fiber Laser Welding of 316L Austenitic and 2304 Lean Duplex Stainless Steels
PublicationThis study presents results of experimental tests on quality of dissimilar welded joints between 316L austenitic and 2304 lean duplex stainless steels, welded without ceramic backing. Fiber laser welded butt joints at a thickness of 8 mm were subjected to non‐destructive testing (visual and penetrant), destructive testing (static tensile test, bending test, and microhardness measurements) and structure observations (macro‐ and...
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Optimization of the femtosecond laser impulse for excitation and the Spin-Orbit mediated dissociation in the NaRb Dimer
PublicationWe 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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Laser Beam as a Precision Tool to Increase Fatigue Resistance in an Eyelet of Undercarriage Drag Strut
PublicationThe 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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Nanoindentation tests titanium alloy Ti-6Al-4V after interference laser treatment
PublicationThe study aimed was to assess selected mechanical properties of surface layers obtained after interference laser treatment – DLIL of titanium alloy Ti-6Al-4V used for implants. The samples were melted in still air at room temperature, for this purpose Nd:YAG laser was used, the number of laser shots was variable. Next, nanoindentation tests were performed, based on which Young’s modulus and nanohardness in the obtained surface...
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Laser-assisted approach for improved performance of Au-Ti based glucose sensing electrodes
PublicationThis paper focuses on the synthesis route and electrochemical properties of electrocatalytic material based on gold nanoparticles (NPs) embedded in a structured titanium template obtained via optimized anodization, chemical etching and laser processing. SEM inspection reveals the presence of Au NPs (60–90 nm in diameter) sited in the titanium foil cavities. Performed electrochemical measurements enable nomination of the set of working...
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On the Formation of Single-Walled Carbon Nanotubes in Pulsed-Laser-Assisted Chemical Vapor Deposition
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The Influence of Laser Surface Alloying on the Thermal Fatigue Resistance of Hot Work Tool Steels
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