IR Thermographic System Supplied with an Ordered Fiber Bundle for Investigation of Power Engineering Equipment and Units

In this article, the authors propose an IR imaging system, supplied with an IR bundle of ordered silver halide fibers, for the acquisition of 2D temperature field distribution in hard-to-reach places. We assessed crosstalk between neighboring individual fibers of the bundle, carried out calibration of the IR imaging system, and determined modelled defects using this system. The results showed the applicability of the system for the inspection and investigation of power engineering units. Keywords: IR fiber bundles, IR thermography, internal defects detectio

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

Estimating the cutting force when skiving with a radius cutter

The paper considers the method of determining the components of the cutting force under cutting completed with a radius cutter. The authors provide the design of the experimental study. The authors provide the data on the cutting force change in the process of turning with a radius cutter according to the cutting edge inclination, cutting depth and supply obtained experimentally and calculated analytically. The paper also provides the results of experimental work approximation and theoretical error checking related to experimental data

Investigating the light stability of solid-solution-based AgCl-AgBr and AgBr-TlI crystals

For the development of mid-infrared fiber-optical elements, one needs light-stable, flexible materials that are transparent within this spectral band. Solid solutions of silver and monadic thallium halides prove to be the most suitable crystalline media for these needs. We study the light stability variation of high-purity AgCl1-xBrx(0 ≤ x ≤ 1) and Ag1-xTlxBr1-xIx (0 ≤ x ≤ 0.05) crystals by measuring the optical transmission change as functions of the composition and UV exposure time. The former is executed in a broad spectral range from 6500 - 350 cm-1, within which we choose three wavelengths to trace the transmission change. For thalliummonoiodide-containing samples, an effect is observed that we assumed to be translucence. © 2016 Chinese Optics Letters

Modeling experimental glaucoma for screening studies of antiglaucomatous activity

The conducted studies of four models of glaucoma and their three modifications in animals made it possible to select two of them, which contributed to a stable and fairly long-term increase in IOP in rabbits (introduction of finely dispersed kaolin into the anterior chamber of the eye) and rats (adrenalineinduced model

Spectral oil analyzer

We worked out a spectral oil analyzer, implemented the method of Fourier transform infrared spectroscopy, which allow simultaneous detecting characteristic peaks of water absorption and sulfur-containing substances in oil within the wavelength range from 0.2 to 25.0 μm. The usage of fiber-optic delivering channels makes it possible to produce online industrial probes for the control of chemical composition and concentration, what is demanded at oil producing platforms and oil refinery plants. As identifiers, we used the most intense absorption peaks of water (λ - 1.45 μm, 1.95 μm, 3.00 μm, 6.00 μm), oil (λ - 1.72 μm, 2.31 μm, 3.41 μm) and sulfur-containing heterocycles (λ - 8.00 μm). The spectral analyzer consists of a broadband-light source, a flow-cell, a fiber-optic assembly, narrow-band optical filters and photodetectors. For delivering a broadband optical signal, a fiber-optic assembly was developed. It comprises silica fibers and polycrystalline fibers derived from solid solutions of silver and thallium (I) halides. It was calculated the effective area and diameter of each fiber type in the assembly, taking into account attenuation coefficients and overall optical losses of the system. Using eight channels for the probe at the same time, we were able to measure the content of water and sulfur-containing substances in oil in concentrations from 0.1 to 100.0 wt %. © 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. 18-73-10063

Thermal Conductivity Measurement of Infrared Optical Fibers Based on Silver Halide Solid Solution Crystals

The aim of the study is to measure the thermal conductivity of silver halide light guides based on crystals of the AgCl-AgBr system used in PSD production technologies. The conductivity temperature coefficient of the samples under study were determined by the laser flash method using the LFA 467 (Hyper Flash) installation. We studied mono- and polycrystalline samples of solid solutions with the composition AgCl0,25AgBr0,75 in the temperature range 298–523 K. The thermal conductivity of the investigated materials was then calculated using literature data on density and heat capacity. The thermal conductivity coefficient ranges from 0.80±0,04 to 0.53±0,03 (W/m·K), depending on the microstructure of the sample. © 2021 Institute of Physics Publishing. All rights reserved.The research has been supported by the grants of President of the Russian Federation, MD-5324.2021.4

Pharmacotherapy of glaucoma in terms of evidence-based medicine

Glaucoma is a disease associated with increased intraocular pressure (IOP). Of the pharmacological agents for treating glaucoma, there are drugs of the first (most effective and safe) and second-line treatment. First-line treatment includes prostaglandin analogs and beta-blockers. The currently used prostaglandin analogs (latanoprost, bimatoprost, tafluprost and travoprost) are PG F2α analogs that act through stimulation of FP receptors. They are distinguished by the optimal ratio of effectiveness and risk of side effects. They are convenient for the patient because for the therapeutic effect, it is enough to prescribe 1 time per day. As a result, it is rational to start the treatment of glaucoma with a drug in this group. In terms of pharmacoeconomics, the most affordable prostaglandin drug is latanoprost, which is generally as effective as other prostaglandin analogs. β-adrenergic blockers reduce the production of intraocular fluid, the formation of which is controlled by β1- and β2-adrenergic receptors. Therefore, non-selective β-blockers (timolol, levobunolol, metipranolol, and carteolol) have a pharmacodynamic advantage over selective β1-adrenergic antagonists (betaxolol). Conducted clinical studies of β-blockers have shown that given the cost, efficacy and safety, timolol was the most preferable treatment for glaucoma. In the presence of medical contraindications to the use of first-line drugs or to enhance their effectiveness, α2-agonists (apraclonidine and brimonidine), carbonic anhydrase inhibitors (usually local action: dorzolamide and brinzolamide), M-cholinomimetics (pilocarpine, carbachol and echothiopate), and also Rho-kinase inhibitors (ripasudil

Creating Nanoscale luminescence Centres in Silver Halides Suitable for Infrared Application

This study shows the possibility of creating luminescence centres in silver halide media using substances based on rare-earth elements such as neodymium, ytterbium and dysprosium. These luminescent substances in the form of fine particles of both nanoscale and microscale dimensions can be introduced into the AgCl0.25Br0.75 ceramic matrix highly transparent in the spectral range of 0.5–35 μm. Our theoretical and experimental studies showed that the introduction of luminescent nanoparticles or microparticles at the amount of 0.5 wt.% into AgCl0.25Br0.75 ceramics neither reduces the level of its transmission in the MIR region nor shortens the range of transmission. What is more, we proved that the luminescent properties of nanoparticles remain well preserved after doping silver halide ceramic media with them. Therefore, silver halides doped with rare-earth elements in question can be used for developing the sources of coherent middle infrared radiation, with appropriate energy levels being excited by optical radiation or pulsed electric field. © 2021 Institute of Physics Publishing. All rights reserved.This work was supported by the Russian Science Foundation (No. 21-73-10108)