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Tytuł:
How new generation lasers are different from each other?
Autorzy:
Chong, Victor
Powiązania:
https://bibliotekanauki.pl/articles/1927427.pdf
Data publikacji:
2018
Wydawca:
Medical Education
Tematy:
diabetic macular edema
macular diseases
micropulse laser
nanosecond laser
non-damaging laser
subliminal laser
Opis:
Laser has changed a lot over the years, the newer laser can deliver energy in different ways, by reducing the duration to 10–20 ms, in a train of pulses of 0.1 ms as in the micropulse / subliminal laser, and extremely short duration of 0.0017 ms as in the nanosecond laser. Clinical studies have shown that micropulse laser is efficacious in multiple macular conditions. Reducing the power and duration using end-point management has yet to demonstrate clinical efficacy beyond CSR. The ability to reduce the progression of intermediate AMD is intriguing, after all the LEAD (Laser intervention in early stages age-related macular degeneration) trial failed the primary endpoint. Nonetheless, there is evidence to support that it may be effective in a highly selected sub-group of intermediate AMD patients. More studies are required to see whether other lasers such as micropulse laser can have the same effect, and whether micropulse lasers with a slightly higher energy leading to a few RPE cell deaths is needed to have the same effect.
Lasery okulistyczne do leczenia schorzeń siatkówki przeszły znaczną ewolucję w ciągu ostatnich lat. Najnowsze urządzenia zapewniają krótszy czas dostarczania energii (10–20 ms): w impulsach trwających 0,1 ms w laserze mikropulsowym/ podprogowym i w impulsach o ultrakrótkim czasie trwania – 0,0017 ms – w laserze nanosekundowym. Badania kliniczne wykazały, że laser mikropulsowy jest skuteczny w wielu stanach chorobowych plamki żółtej. Trwają badania nad określeniem skuteczności klinicznej przy zastosowaniu mniejszej mocy i krótszego czasu aplikacji, uzyskanych dzięki metodzie end-point management we wskazaniach innych niż centralna retinopatia surowicza. Możliwości spowolnienia progresji średnio zaawansowanego zwyrodnienia plamki żółtej (AMD) wydają się realne, mimo że w badaniu LEAD (Laser Intervention in Early Stages Age-related Macular Degeneration) nie udało się osiągnąć tego założonego pierwszorzędowego punktu końcowego. Dysponujemy jednak licznymi poszlakami wskazującymi, że sukces jest możliwy w precyzyjnie wyselekcjonowanej podgrupie pacjentów z AMD. Potrzebne są zatem kolejne badania, aby jednoznacznie stwierdzić, czy urządzenia takie jak laser mikropulsowy mogą zapewnić satysfakcjonujący efekt terapeutyczny i czy lasery mikropulsowe o nieco większej energii, które powodują zniszczenie większej liczby komórek RPE, są niezbędne do osiągnięcia tego efektu.
Źródło:
OphthaTherapy; 2018, 5, 4; 217-221
2353-7175
2543-9987
Pojawia się w:
OphthaTherapy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Laser modification of the materials surface layer - a review paper
Autorzy:
Kusiński, J.
Kac, S.
Kopia, A.
Radziszewska, A.
Rozmus-Górnikowska, M.
Major, B.
Major, L.
Marczak, J.
Lisiecki, A.
Powiązania:
https://bibliotekanauki.pl/articles/201655.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
lasers in Poland
laser surface heat treatment
laser melting
alloying
cladding
laser ablation
laser cleaning
laser shock processing (LSP)
laser texturing
multilayer coatings
Opis:
The state of laser processing in surface materials modification in Poland is reported, based on own experience, coworkers and coauthors results, as well the literature review. The curriculum concerning historical development of lasers and laser technology in Poland, laser-matter interaction, as well basis of different laser techniques applied in materials surface engineering (solid state hardening, melting, alloying, cladding, ablation, shot peening, cleaning and texturing) are reviewed, and compared with results of coauthors, as well with a wide range of Polish authors papers. Finally, it is concluded that overall state of research on laser application in surface engineering in Poland is well developed and still growing industrial application is observed.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2012, 60, 4; 711-728
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of impact of atmospheric attenuation and measurement uncertainties on laser hazard distances in navigable airspace for visible cw laser radiation
Autorzy:
Młyńczak, Jarosław
Powiązania:
https://bibliotekanauki.pl/articles/27311745.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
aviation safety
laser hazard distances in navigable airspace
laser safety
laser hazard distance
laser illumination
Opis:
This document provides a simplified solution to the problem of calculation of laser hazard distances defined in the Advisory Circular 70-1B by the U.S. Federal Aviation Administration regarding atmospheric attenuation (assuming its constant value) and measurement uncertainties. The calculation approaches and examples presented in this document do not specify the procedure that should be followed in the case of atmospheric attenuation, nor do they take into account the uncertainties associated with the measured parameters. The analysis presented in the article complements to some extent AC 70-1B and can be used by those who need such a simplified solution regarding illumination of landing or taking off aircrafts. The article presents a sample analysis for a typical laser pointer, where the necessary parameters of the laser beam along with the appropriate uncertainties were determined in accordance with the methods accredited by the Polish Centre for Accreditation while the appropriate laser hazard distances were calculated taking into account different atmospheric attenuation coefficients.
Źródło:
Metrology and Measurement Systems; 2023, 30, 2; 259--272
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The use of laser therapy in retinal diseases. Part III
Zastosowanie laseroterapii w chorobach siatkówki. Część III
Autorzy:
Warzecha, Katarzyna
Tronina, Agnieszka
Filipek, Erita
Powiązania:
https://bibliotekanauki.pl/articles/1928017.pdf
Data publikacji:
2020
Wydawca:
Medical Education
Tematy:
laser photocoagulation
laser therapy
retinal diseases
Opis:
Retinal diseases account for the vast majority of ophthalmologic disorders. Over the past years, laser-based approach has been successfully used. Despite introduction of other potentially innovative, beneficial and successful therapeutic methods, lasers are still considered the gold standard. In this review, we discuss the spectrum of currently prevailing laser methods and new insights into novel perspectives and techniques regarding laser management of retinal disorders. This paper is divided into three sections. Two parts, already published in previous issues, have presented methodology with the spectrum of laser-based techniques and literature review investigating the existing knowledge in laser management of diabetic retinopathy, diabetic macular edema and vascular retinal disorders. Finally, the current one, consists of the principles guiding laser treatment of retinal tears, retinal degeneration, retinopathy of prematurity, age-related macular degeneration and other retinal diseases.
Choroby siatkówki stanowią dużą grupę schorzeń narządu wzroku. W leczeniu wielu z nich od lat z powodzeniem jest stosowana laseroterapia. Mimo prób wprowadzania innych metod leczniczych nadal pozostaje ona jedną z głównych opcji terapeutycznych. W pracy przedstawiono przegląd piśmiennictwa dotyczący zastosowania laseroterapii w chorobach siatkówki, z uwzględnieniem nowych rodzajów i metod tej formy leczenia. Pracę podzielono na trzy części. Dwie pierwsze, które ukazały się w poprzednich numerach, zawierały opis metodyki oraz rodzajów zabiegów laserowych i przegląd piśmiennictwa dotyczący laseroterapii w retinopatii cukrzycowej, cukrzycowym obrzęku plamki oraz chorobach naczyniowych siatkówki. W niniejszej części zaprezentowany został przegląd piśmiennictwa dotyczący laseroterapii w przedarciach oraz chorobach zwyrodnieniowych siatkówki, retinopatii wcześniaków, zwyrodnieniu plamki związanym z wiekiem oraz innych chorobach siatkówki.
Źródło:
OphthaTherapy; 2020, 7, 4; 333-340
2353-7175
2543-9987
Pojawia się w:
OphthaTherapy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Laser nuclear fusion: current status, challenges and prospect
Autorzy:
Badziak, J.
Powiązania:
https://bibliotekanauki.pl/articles/201663.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
laser
plasma
inertial fusion
laser acceleration
Opis:
In 2009, in Lawrence Livermore National Laboratory, USA, National Ignition Facility (NIF) - the largest thermonuclear fusion device ever made was launched. Its main part is a multi-beam laser whose energy in nanosecond pulse exceeds 1MJ (106 J). Its task is to compress DT fuel to the density over a few thousand times higher than that of solid-state DT and heat it to 100 millions of K degrees. In this case, the process of fuel compression and heating is realized in an indirect way - laser radiation (in UV range) is converted in the so-called hohlraum (1 cm cylinder with a spherical DT pellet inside) into very intense soft X radiation symmetrically illuminating DT pellet. For the first time ever, the fusion device's energetic parameters are sufficient for the achieving the ignition and self-sustained burn of thermonuclear fuel on a scale allowing for the generation of energy far bigger than that delivered to the fuel. The main purpose of the current experimental campaign on NIF is bringing about, within the next two-three years, a controlled thermonuclear 'big bang' in which the fusion energy will exceed the energy delivered by the laser at least ten times. The expected 'big bang' would be the culmination of fifty years of international efforts aiming at demonstrating both physical and technical feasibility of generating, in a controlled way, the energy from nuclear fusion in inertial confined plasma and would pave the way for practical realization of the laser-driven thermonuclear reactor. This paper briefly reviews the basic current concepts of laser fusion and main problems and challenges facing the research community dealing with this field. In particular, the conventional, central hot spot ignition approach to laser fusion is discussed together with the more recent ones - fast ignition, shock ignition and impact ignition fusion. The research projects directed towards building an experimental laser-driven thermonuclear reactor are presented as well.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2012, 60, 4; 729-738
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
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:
The Influence of Treatment Parameters on the Microstructure, Properties and Bend Angle of Laser Formed Construction Bars
Autorzy:
Kurp, P.
Mucha, Z.
Tofil, S.
Mulczyk, K.
Powiązania:
https://bibliotekanauki.pl/articles/353966.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
laser forming
laser treatment
microstructure
Fourier number
Opis:
In this paper, the authors presented the research on laser formed construction bars made of C20 steel on the example of the T-shape. The CO2 TRUMPF TruFlow 6000 laser was used in the research. The influence of the laser treatment parameters (the power and speed of the heat source) on the volume of the bend angle, structure and properties of the elements (hardness and tensile strength) was examined. On the basis of the results obtained from the conducted experiments, the authors suggested a way of selecting treatment parameters so that the element should meet the strength assumptions at the allowable time of its implementation.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 2B; 1151-1156
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Studies of plasma and craters produced by the interaction of high-energy sub-nanosecond laser with silver target
Autorzy:
Woryna, E.
Badziak, J.
Parys, P.
Suchańska, R.
Wołowski, J.
Krása, J.
Láska, L.
Pfeifer, M.
Rohlena, K.
Ullschmied, J.
Powiązania:
https://bibliotekanauki.pl/articles/147102.pdf
Data publikacji:
2002
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
ion beam
laser
laser-induced crater
plasma
Opis:
The results of measurements of microablation from a silver target irradiated by the high-power PALS laser system in Prague are presented. In this experiment the laser beam of energy of about 110 J in a 400 ps pulse was focused perpendicularly to the massive silver target. The target surface position was changed with respect to the focal spot of the laser beam in the range from -2.5 to 2.5 mm. A set of four ion collectors was used for plasma ion emission measurements. The effect of the laser pulse interaction with the target, i.e. craters and damages formed in the vicinity of the craters, were investigated with the use of scanning electron microscopy (SEM) and optical microscopy methods. The characteristics of the crater were compared with the essential parameters of ion streams emitted from the plasma produced in the same laser shot.
Źródło:
Nukleonika; 2002, 47, 4; 147-150
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of wireless audio transmission circuit using laser technology
Autorzy:
KARAARSLAN, Ahmet
ÖZER, Tolga
Powiązania:
https://bibliotekanauki.pl/articles/457189.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Rzeszowski
Tematy:
laser
audio transmission
wireless communication
laser technology
Opis:
In technology, we see major innovation and improvements in our daily tools and machines. Meanly, technology is in constant race to get better than yesterday. It has been amazing upwards trend in technology over last 20 years to the level of „space time”. One of the major technology development areas are in the laser field. Although laser technology has been out there for many years, we have seen tremendous new laser applications recently. We are taking advantage of laser technology in all aspects of our life. As long as we use its precise and right parametric range, we get very valuable results. In this study, general information about lasers and laser wireless audio transmission circuit application was designed.
Źródło:
Edukacja-Technika-Informatyka; 2013, 4, 2; 378-392
2080-9069
Pojawia się w:
Edukacja-Technika-Informatyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of Titanium Metal Matrix Composite Surface Layers Produced During Laser Gas Nitriding of Ti6Al4V Alloy by Different Types of Lasers
Autorzy:
Lisiecki, A.
Powiązania:
https://bibliotekanauki.pl/articles/351670.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
titanium alloys
laser gas nitriding
composite surface layer
disk laser
diode laser
Opis:
The article presents the results of a comparative study of the nitriding process of titanium alloy substrate using two lasers with different characteristics of laser beams. One of the applied lasers was a high power diode laser emitting at a dominant wavelength of 808 nm, with a rectangular laser beam spot, and multimode energy distribution across the spot. The second laser was a solid state Yb:YAG disk laser emitting at a wavelength of 1.03 μm, with a circular beam spot, characterized by near Gaussian energy distribution across the spot. In a case of both lasers single stringer beads with a similar width and at similar energy input were produced. As a result of melting of the substrate with a laser beam in a pure gaseous nitrogen atmosphere composite surface layers with in situ precipitated titanium nitrides embedded in the metallic matrix of titanium alloy were produced, in both cases. However, the surface topography and structure is different for the surface layers produce by different lasers at the same processing parameters and width of laser beams.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 4; 1777-1784
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Laser percussive strengthening of the aluminum alloys
Autorzy:
Napadłek, W.
Powiązania:
https://bibliotekanauki.pl/articles/244534.pdf
Data publikacji:
2011
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
laser radiation
aluminum alloys
laser percussive strengthening
Opis:
The matter of laser percussive strengthening by shock wave generated from laser pulse (LSP - Laser Shock Peening or LPS - Laser Percussive Strengthening) is presented. The building of the investigative position to making the quick photo of the laser influence with the subject was described. The idea of the registration of fast changing physical processes kinetics setting near the influence of short laser impulses with the aluminum alloys (ENAW-2017A and ENAW-2618A) was introduced. Variants were applied for enlargement of the process efficiency of laser strengthening in laboratory experiments from thin absorbing coat and inert layer (water). The tests results of the surface layer strengthening of ENAW-2017A and ENAW-2618A aluminum alloys are described. Those investigations enclose selection of strengthening parameters above named materials, measurement of: the surface topography, microstructure, micro-hardness and also fatigue investigations in restricted range for sigma =180 i 350 MPa. It was confirmed essential influence of surface topography as well as created subsoil microstructure on the fatigue life of strengthening samples. Obtained research results were confirmed very beneficial influence of used surface strengthening processing on the fatigue life.
Źródło:
Journal of KONES; 2011, 18, 1; 373-383
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Praktyczne wykorzystanie laserów w probiernictwie
The practical using of lasers in hallmarking
Autorzy:
Wójtowicz, Robert
Powiązania:
https://bibliotekanauki.pl/articles/952555.pdf
Data publikacji:
2016
Wydawca:
Główny Urząd Miar
Tematy:
laser
znakowanie laserowe
probiernictwo
laser marking
hallmarking
Opis:
Niniejsze opracowanie stanowi kontynuację artykułu „Lasery w urzędach probierczych”, zamieszczonego w poprzednim numerze Biuletynu GUM „Metrologia i Probiernictwo” [nr 1(12) 2016]. W artykule opisano metody umieszczania oznaczeń na wyrobach ze stopów metali szlachetnych, przy użyciu urządzenia do laserowego oznaczania oraz omówiono sprawy jakości i trwałości wykonywanych wizerunków w Okręgowym Urzędzie Probierczym w Krakowie i w jego wydziałach zamiejscowych.
This is a continuation of the article “Lasers in Assay Offices” stated in the previous issue of the Journal “Metrology and Hallmarking” Nr 1(12) 2016. The article describes the method of marking for articles of precious metal alloys, using a laser marking and discusses the quality and durability of images made at the Regional Assay Office in Krakow and branches.
Źródło:
Metrologia i Probiernictwo : biuletyn Głównego Urzędu Miar; 2016, 2 (13); 58-62
2300-8806
Pojawia się w:
Metrologia i Probiernictwo : biuletyn Głównego Urzędu Miar
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Laser-Assisted Thermomechanical Bending of Tube Profiles
Autorzy:
Widłaszewski, J.
Nowak, M.
Nowak, Z.
Kurp, P.
Powiązania:
https://bibliotekanauki.pl/articles/355622.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
laser forming
laser-assisted bending
numerical modelling
Opis:
The subject of the work is the analysis of thermomechanical bending process of a thin-walled tube made of X5CrNi18-10 stainless steel. The deformation is produced at elevated temperature generated with a laser beam in a specially designed experimental setup. The tube bending process consists of local heating of the tube by a moving laser beam and simultaneous kinematic enforcement of deformation with an actuator and a rotating bending arm. During experimental investigations, the resultant force of the actuator and temperature at the laser spot are recorded. In addition to experimental tests, the bending process of the tube was modelled using the finite element method in the ABAQUS program. For this purpose, the tube deformation process was divided into two sequentially coupled numerical simulations. The first one was the heat transfer analysis for a laser beam moving longitudinally over the tube surface. The second simulation described the process of mechanical bending with the time-varying temperature field obtained in the first simulation. The force and temperature recorded during experiments were used to verify the proposed numerical model. The final stress state and the deformation of the tube after the bending process were analyzed using the numerical solution. The results indicate that the proposed bending method can be successfully used in forming of the thin-walled profiles, in particular, when large bending angles and a small spring-back effect are of interest.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 1; 421-430
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transmitter with quantum cascade laser for free space optics communication system
Autorzy:
Gutowska, M.
Pierścińska, D.
Nowakowski, M.
Pierciński, K.
Szabra, D.
Mikołajczyk, J.
Wojtas, J.
Bielecki, Z.
Powiązania:
https://bibliotekanauki.pl/articles/200097.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
optical link
quantum cascade laser
laser communications
Opis:
The paper presents results of experimental tests of the quantum cascade laser from Alpes Lasers company in terms of its application in the optic communication system in an open space. The measurements involved the current – voltage characteristics while measuring also the average power of emitted radiation, and spectral characteristics for different temperatures and different laser pulse durations. The duration of laser pulses was matched to parameters used in telecommunication interfaces. The construction of the transmitter module which uses the tested laser is also presented.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2011, 59, 4; 419-423
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł

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