Transmission of thermal imaging by using infrared bundle based on silver halide solid solution

In this study, infrared bundle consisting of seven single fibres was manufactured. Experiences on transmission of the heated object thermal image was performed. The experimental data show that there is a fundamental possibility of thermal image transmission through the infrared bundle. © Published under licence by IOP Publishing Ltd

Optical Fibers Based on Modified Silver Halide Crystals for Nuclear Power

We investigated the possibility of the deployment of AgBr – TlBr0.46I0.54MIR fibers in high ionizing radiation environment. For this purpose, we exposed plate samples made of AgBr – TlBr0.46I0.54crystals to β-ionizing radiation at a dose of 100 kGy. We revealed the radiation-induced translucence effect for these materials and assumed its nature. As the investigation showed the suitability of the fibers for the application in high ionizing radiation environment, the authors propose to use these fibers jointly with FTIR spectrometers for the online monitoring of various chemical processes at the nuclear power plants. Keywords: modified silver halides, MIR fibers, FTIR spectroscopy, ionizing radiation resistanc

Crystals based on solid solution of Ag1-xTlxBr1-xIx for the manufacturing of IR fibers

For the development of fiber optics for the range from 0.2 to 50.0 μm, one needs light-stable, nonhygroscopic, ductile crystals that would be transparent within this spectral range and have a lack of cleavage, and from which the flexible infrared (IR) fibers are extruded. The crystals based on solid solutions of silver and monadic thallium halides meet the conditions listed above. Consequently, by differential thermal and x ray analyses, we study the TlBr-TlI phase diagram using the crystals with optimal compositions, which we grow ourselves. We also manufacture light-stable nanocrystalline IR fibers that are transparent at longer wavelengths compared with AgCl-AgBr fibers. � 2015 Chinese Optics Letters

Simulation of infrared photonic crystal fibers based on crystals system AgBr - TlBr0.46I0.54

In this paper, a computer simulation of photonic crystal fibers (PCF) based on the AgBr - TlBr0.46I0.54 system was performed. The simulation was carried out in the SMTP program integrated into Matlab. As a simulation result, PCF with the hexagonal structure of PBG-inserts with an increased mode field diameter of up to 200 μm was obtained. © Published under licence by IOP Publishing Ltd.Russian Science Foundation, RSF: 18-73-10063This work was supported by the Russian Science Foundation under grant No. 18-73-1006

Manufacture of optical ceramics based on two solid solutions of the AgBr - (TlBr0.46I0.54) system

This work is devoted to the synthesis and the optical properties study of a new multicomponent heterophase ceramic based on two solid solutions of the AgBr - (TlBr0.46I0.54) system. Ceramics are transparent in the infrared range from 1.0 to 40.0 ÷ 50.0 μm, non-hygroscopic, are photo- and radiation-resistant, flexible, as a result of which various optical products are made from it by hot embossing. © Published under licence by IOP Publishing Ltd.This work was supported by the Russian Science Foundation under grant No. 18-73-10063

Highly Transparent Ceramics for the Spectral Range from 1.0 to 60.0 μm Based on Solid Solutions of the System AgBr-AgI-TlI-TlBr

The article is devoted to the technology for obtaining optical ceramics of AgBr-TlI and AgBr-TlBr0.46I0.54 systems and manufacturing samples with different compositions. The new heterophase crystal ceramics are transparent without absorption windows in the spectral range from 1.0 to 60.0 μm. In the ceramics' transparency spectra based on the AgBr-TlI and AgBr-TlBr0.46I0.54 systems fusibility diagrams, with an increase in the thallium halides mass fraction, as well as the replacement of the bromine ion with iodine, the maximum transparency shifts to a long infrared region. © 2021 Chinese Optics Letters.This work was supported by the Russian Science Foundation (No. 18-73-10063)

Influence of geometrical parameters on transmitting thermal radiation through silver halide fibers

In this study, we experimentally determined the influence of fibers’ geometrical parameters on the performance of fiber-optic temperature control system based on silver halide fibers at the temperatures of 295–395 K. It was revealed that the fiber diameter can affect thermal radiation transmission in the case of mismatching light beam diameters between system's optical elements and it should be taken into consideration when such systems are developed. A fiber length reduction leads to a linear increase in transmission values. We also assessed transmission losses for the fibers bent at various radii and derived some empirical equations for calibration curves. The revealed dependencies can be very useful for designing fiber-optic systems intended for remote temperature measurements and control of heating-power facilities’ thermal regimes. © 2020 The AuthorsRussian Science Foundation, RSF: 18-73-10063This work was supported by the Russian Science Foundation under grant No. 18-73-10063

SIMULATION OF EXTRUSION PROCESS OF INFRARED FIBERS BASED ON SILVER AND THALLIUM (I) HALIDES

To optimize extrusion process of infrared fibers based on silver and thallium (I) halides, a computer simulation using the finite element method is proposed. As a modeling result, the optimal values of the plunger speed and billet temperature were selected.Исследование выполнено за счет гранта Российского научного фонда № 21-73-10108, https://rscf.ru/project/21-73-10108/

Method for Obtaining Silver Halide Light Guides Based on AgClagCl 0.25Br0.75 - AgI Nanoceramics

Изобретение относится к материалам для инфракрасной (ИК) волоконной оптики, а именно к галогенидсеребряным световодам. Способ получения галогенидсеребряных световодов на основе нанокерамики системы AgCl0,25Br0,75 - AgI включает компьютерное моделирование по методу конечных элементов для определения параметров экструзии - температуры, давления плунжера на галогенидсеребряную заготовку и скорости перемещения заготовки через фильеру при получении световодов, при этом нанокерамическую заготовку диаметром 8,0 мм, высотой 16,0 мм на основе двух твердых растворов гексагональной фазы структурного типа вюрцит, P63mc, и кубической фазы структурного типа NaCl, Fm3m, состава AgCl0,25Br0,75, дополнительно содержащей йодид серебра при определенном соотношении ингредиентов, нагревают до 170°С, выдерживают в течение 60 минут для прогрева заготовки и при давлении плунжера в 1200 МПа и его вибрации на заготовку частотой 50 Гц, амплитудой 50 мкм, что обеспечивает ее перемещение со скоростью 0,6 мм/мин для формирования галогенидсеребряного световода диаметром 450 мкм, длиной 5 м с дефектной поверхностью в виде поперечных канавок глубиной 5 мкм, шириной 10 мкм и шагом в 80 мкм. Изобретение обеспечивает получение радиационно стойких галогенидсеребряных световодов с дефектной структурой, прозрачных в среднем и дальнем ИК диапазонах от 3,0 до 27,0 мкм, что позволяет детектировать спектры химических соединений при определении химических веществ с высокой чувствительностью до 0,0005 моль/л в более широком спектральном диапазоне. 3 ил., 3 пр.FIELD: materials for infrared (IR) fibre optics. SUBSTANCE: invention is related to silver halide light guides. The method for producing silver halide fibres based on nanoceramics of the AgCl0.25Br0.75 - AgI system includes computer simulation using the finite element method to determine the extrusion parameters - temperature, plunger pressure on the silver halide billet and the speed of movement of the billet through the spinneret when obtaining fibres, while nanoceramic workpiece with a diameter of 8.0 mm, a height of 16.0 mm based on two solid solutions of a hexagonal phase of the wurtzite, P63mc structure, and a cubic phase of the NaCl, Fm3m structure, composition AgCl0.25Br0.75, additionally containing silver iodide at a certain ratio of ingredients, is heated to 170°C, exposed for 60 minutes to warm up the workpiece and at a plunger pressure of 1200 MPa and its vibration on the workpiece with a frequency of 50 Hz, an amplitude of 50 mcm, which ensures its movement at a speed of 0.6 mm/min to form a silver halide light guide with a diameter of 450 mcm, length of 5 m with a defective surface in form of transverse grooves with a depth of 5 mcm, a width of 10 mcm and a step of 80 mcm. EFFECT: invention enables production of radiation-resistant silver halide fibres with a defective structure, transparent in the mid and far IR ranges from 3.0 to 27.0 mcm, which makes it possible to detect the spectra of chemical compounds when determining chemicals with high sensitivity up to 0.0005 mol/l in a wider spectral range. 1 cl, 3 dwg, 3 ex

Surgical Aid to Patients with Hepatopancreatobiliary Situations in Precovid Period and under Persistent Relapse of New Coronavirus Infection SARS-CoV-2

Introduction. The third wave of the new coronavirus infection (COVID-19) pandemic warrants total mobilisation of healthcare and social resources. In this respect, a pressing issue remains the provision of routine and emergency surgical care in patients with hepatopancreatobiliary diseases.Materials and methods. A retrospective analysis of the surgical outcomes in 5,040 hepatopancreatobiliary patients was carried out; this accounted for 51.1 % of the total abdominal surgeries.Results and discussion. Biliary lithiasis and its complications — choledocholithiasis with obstructive jaundice and residual choledocholithiasis — (54.4 %) as well as acute calculous cholecystitis (18.7 %) were operated most frequently. A sharp decrease over all hepatopancreatobiliary nosologies was registered for the surgical interventions in first pandemic year 2020. Thus, the median annual number of operations for biliary lithiasis and its complications was 550 (482–592 year-range) in the precovid period, while dropping to only 321 at the onset of pandemic (p <0.05). A first sixmonth survey of year 2021 revealed a growth of surgical activity for all hepatopancreatobiliary nosologies.Conclusion. Hepatopancreatobiliary operations prevail (54.4 % cases) in the total structure of level 3 abdominal surgical interventions. A high annual rate of surgical operations over nearly all hepatopancreatobiliary nosologies was interrupted in the first year of the new coronavirus infection outbreak. Meanwhile, the first half of 2021 showed a clear tend towards restoring the precovid statistical indicators, despite the stressful conditions of persistently relapsing COVID-19 that surgical facilities had faced