Publications by authors named "Voropaev V"

Owing to their high producibility and resistance to corrosion, austenitic chromium-nickel steels are widely used in the chemical, petroleum, and food industries. However, their significant disadvantage lies in their poor structural performance, which cannot be improved by heat treatment. This significantly limits the usability of these steels in parts of machines that operate under friction loads.

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Ultrashort laser pulse sources in the wavelength range of 1.8 to 2 µm have many potential applications including medicine, materials processing, and sensing. In the use of such lasers, a crucial task is to measure their pulse's temporal intensity and phase.

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Age-related macular degeneration complicated by submacular hemorrhage if not treated timely leads to permanent loss of central vision. The basis of effective therapy is its early start, dislocation of blood from central parts of the retina and blockage of neovascularization. This review examines the current methods of treatment of submacular hemorrhages, anatomical and functional outcomes, risks of postoperative complications, as well as trends in the use of combined methods of surgical intervention.

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The duration reduction and the peak power increase of ultrashort pulses generated by all-fiber sources at a wavelength of [Formula: see text] are urgent tasks. Finding an effective and easy way to improve these characteristics of ultrafast lasers can allow a broad implementation of wideband coherent supercontinuum sources in the mid-IR range required for various applications. As an alternative approach to sub-100 fs pulse generation, we present an ultrafast all-fiber amplifier based on a normal-dispersion germanosilicate thulium-doped active fiber and a large-mode-area silica-fiber compressor.

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We report a study of the response function parameters (amplitude and rise/fall time) of a high-speed GaSb/GaInAsSb/GaAlAsSb photodiode operating at 1.9 µm as a function of optical input power and reverse bias voltage. The experimental measurement results yield the optimal pulse energy and optimal reverse bias voltage for the photodiode.

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The problem associated with the prevalence of retinal diseases, and age-related macular degeneration (AMD) in particular, is undoubtedly relevant. This aspect is based on steadily growing statistics on morbidity, a high number of randomized controlled trials (RCT) and published real world data (RWD). The analysis of RCT results being published by researchers on 15.

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Ultrafast Tm-doped fibre lasers have been actively studied for the last decade due to their potential applications in precise mid-IR spectroscopy, LIDARs, material processing and more. The majority of research papers is devoted to the comparison between a numerical modelling and experimental results; however, little attention is being paid to the comprehensive description of the mathematical models and parameters of the active and passive components forming cavities of Tm-doped all-fibre lasers. Thus, here we report a numerical model of a stretched-pulsed Tm-doped fibre laser with hybrid mode-locking and compare it with experimental results.

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We report a study on the switching of the generation regimes in a high-powered thulium-doped all-fiber ring oscillator that is passively mode-locked with nonlinear polarization evolution technique with different pumping rates and cavity dispersion values. In one experimental setup, switching was observed between the noise-like pulse and the multi-soliton (in the forms of soliton bunches and soliton rain) regimes by the adjustment of the intracavity polarization controllers. We attributed this to the crucial influence of the nonlinear polarization evolution strength determined by such key parameters as saturation (over-rotation) power, linear phase bias, and nonlinear losses on the pulse evolution and stability.

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We report on ultra-short stretched pulse generation in an all-fiber erbium-doped ring laser with a highly-nonlinear germanosilicate fiber inside the resonator with a slightly positive net-cavity group velocity dispersion (GVD). Stable 84 fs pulses were obtained with a 12 MHz repetition rate at a central wavelength of 1560 nm with a 48.1 nm spectral pulse width (full width at half maximum, FWHM) and 30 mW average output power; this corresponds to the 29.

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Aim: to determine the scope of infrainguinal revascularization of the limb in patients with multilevel lesions of arteries in chronic critical lower limb ischaemia (CCLLI).

Material And Methods: A retrospective analysis of graft patency and limb salvage included a total of 76 patients undergoing a total of 78 bypass procedures consisting of: 1) two-level infrainguinal reconstructions (n = 35), 2) femoral-tibial (n = 36) and femoralplantar (n 7) bypass procedures. All patients had an isolated segment, of the popliteal artery in a combination with bifurcation arterial occlusive disease.

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There was summarized experience of surgical treatment of 88 patients with narcotic dependence, in whom the hemorrhage have occurred due to postinjection injury of the main vessels. Reconstructive-restorational operations were conducted in acute period in the absence of sepsis, hemorrhagic shock and vast focus of infection, using auto vein and in the remote period--synthetic prostheses. All the patients, suffering narcotic dependence, admitted to the clinic, are considered as probably AIDS-infected.

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