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

Morfološke značajke oporavka jetrenog parenhima nakon eksperimentalno izazvanog oštećenja

The aim of the study was to investigate morphological traits of hepatic parenchymal tissue repair in response to injury using the conventional technique (closure) and an innovation method (such as hemostatic medication swab packing and modified batching). The experimental study was carried out on laboratory rats of the Winzar breed using light microscopy, standard stains for micropreparations, and morphometry. Histopathologic examination of micropreparations stained by standard methods revealed pronounced dystrophic processes in hepatocytes located near the necrotic zone (albuminous and hydropic degeneration and chromatin fragmentation in the nuclei). Morphometric studies showed a significant decrease (p<0.001) in almost all indicators of the size of cells and nuclei both near necrosis and distant from it on day 28 of the experiment in the experimental group in comparison to the control group. The results obtained pointed to more intense repair processes when applying the innovation method.Cilj istraživanja bio je ispitati morfološke značajke oporavka parenhimnog tkiva jetre u odgovoru na oštećenje primjenom konvencionalne tehnike (zatvaranje) i inovacijske metode (kao što je oblaganje gazom natopljenom hemostatskim lijekom i modificiran batching). Ovo eksperimentalno istraživanje provedeno je na laboratorijskim Winzar štakorima primjenom svjetlosne mikroskopije, standardnih boja za mikropreparate i morfometrije. Histopatološka analiza mikropreparata obojenih standardnim metodama pokazala je znatne distrofične procese u hepatocitima blizu nekrotične zone (albuminozna i hidropična degeneracija, fragmentacija kromatina u jezgrama). Morformetrijska ispitivanja pokazala su značajno smanjenje (p<0,001) svih pokazatelja veličine stanica i jezgara kako blizu nekroze tako i dalje od nje 28. dana eksperimenta u eksperimentalnoj skupini u usporedbi s kontrolnom skupinom. Dobiveni rezultati ukazuju na intenzivnije procese oporavka kad je primijenjena inovacijska metoda

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

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

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

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

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

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

Predicting the subclinical carotid atherosclerosis in overweight and obese patients using a machine learning model

Aim. To develop a model for predicting the subclinical carotid atherosclerosis (SCA) in order to refine cardiovascular risk (CVR) using machine learning methods in overweight and obese patients without hypertension, diabetes and/or cardiovascular disease (CVD).Material and methods. Anonymized database (DB) Webiomed (2.9 million patients) was used. There were following inclusion criteria: age ≥18 years, body mass index ≥25 kg/m2, availability of data on ultrasound of extracranial arteries. Patients with hypertension, diabetes and/or CVD were excluded from the analysis. Data on 5750 patients were selected, of which atherosclerotic plaques were detected in 385 people. The final data set contained information on 447 patients, 197 (44,1%) of which had SCA. Quantitative and categorical traits for model training were taken with 40% occupancy in the database. The number of final traits for machine learning was 28. When creating the model, 3 Random Forest algorithms, AdaBoostClassifier, KNeighborsClassifier and the Scikit-learn library were used. To improve the model performance, the fill missing function was used. The target parameters of the model were given a predictive ability (accuracy) of at least 75%, while the area under the ROC curve was at least 0,75.Results. The resulting dataset was divided into training and test parts in a ratio of 80:20. Depending on the applied algorithms, the learned model was characterized by a predictive ability of 75-97%, sensitivity of 77-92%, specificity of 80-98%, and area under the ROC-curve of 0,88-0,97. Taking into account the accuracy metrics, the best results were obtained for the model learned by the Random Forest algorithm (95%, 92%, 98% and 0,95, respectively).Conclusion. The developed model can help a physician make a decision to refer an overweight and obese patient without cardiovascular diseases for ultrasound of extracranial arteries, which contributes to a more accurate CVR stratification. The introduction of such risk stratification algorithms into practice will increase the accuracy and quality of CVR prediction and optimize the system of preventive measures

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