Luminescence of sapphire single crystals irradiated with high-power ion beams

Optical absorption, photo- and cathodoluminescence of a sapphire single crystal (α-Al 2 O 3 ) exposed to pulsed nanosecond radiation with high-power ion beams C + /H + with an energy of 300 keV and energy density 0.5-1.5 J/cm 2 were first investigated in this work. It was found that under ion irradiation accompanied by heating of sapphire up to melting, the formation of F-type centers and their aggregates associated with oxygen vacancies was observed in the crystals under study. These centers have luminescence bands at 330, 410 and 500 nm which depend on the type and wavelength of the optical excitation. The appearance of a new PL emission at 435 nm, presumably associated with a complex vacancy-impurity defect, was also observed in the photoluminescence spectra. © Published under licence by IOP Publishing Ltd.The work was supported by the initiative scientific project № 16.5186.2017/8.9 of the Ministry of Education and Science of the Russian Federation. Experiments on ion irradiation of sapphire was done at the KIPT as a part of the state task

Research of kinetics of zinc leaching with sulfuric acid from smithsonite

The study investigates the kinetics of zinc leaching from smithsonite with sulfuric acid in order to expand the zinc production feedstocks. The recovery rate of zinc from smithsonite into water-soluble zinc sulfate was found at different leaching time and temperature. Sulfuric acid concentration, its consumption and smithsonite particles size selected in this work for leaching of zinc from this mineral using the indicated solution allowed to determine the magnitude of “apparent” activation energy of the smithsonite reaction with the indicated acid, equal to 2,633 kJ / mol. The calculated value of E, shows that the process investigated is accompanied by diffusion phenomena

Investigation of the kinetics of sulphuric acid leaching of zinc from calamine

This article aims at the research of kinetics of the sulphuric acid leaching of zinc from calamine (hemimorphite) of Shaimerden deposits. The ratio of zinc extraction from calamine to water-soluble zinc sulphate was determined at various leaching durations and its temperatures. The concentration of the sulfuric acid solution, the flow rate of this solution and the size of the calamine particles, selected in the course of this work for leaching zinc from this mineral with the specified solution, made it possible to establish the value of the “apparent” activation energy of the reaction of calamine with sulfuric acid, amounting to 3,075 kJ / mol

Conversion processes for high-viscosity heavy crude oil in catalytic and noncatalytic aquathermolysis

© 2014 Springer Science+Business Media. We have conducted experiments on noncatalytic and catalytic aquathermolysis of high-viscosity heavy crude oil from the Ashal'cha field (Tatarstan) in the presence of a crude oil-soluble nickel- and cobalt-containing catalyst, a proton donor, and a rock-forming mineral. We have identified the characteristic features of the change in the constituent composition, the hydrocarbon composition, and the fractional composition, the rheological properties of the crude oils, the average molecular weight of the asphaltenes for catalytic and noncatalytic conversion processes. For catalytic aquathermolysis, we established significant de novo formation of light 70°C-250°C fractions (by 23 wt.%), n-alkylbenzenes, an increase in the oil content by a factor of 1.3, a decrease in the resin content by a factor of 1.7, and a decrease in the viscosity by 98 rel.%. The major difference between the conversion of crude oil in the presence of the catalyst and the proton donor involves activation of degradation reactions at C-C, C-N, C-O, C-S bonds and blocking of polymerization reactions and accordingly less coke formation. We observed sorption of the catalyst components on rock

Luminescent Properties of Nanostructured Al2O3 Ceramics Irradiated with C+/H+ Pulsed Ion Beams

The luminescent properties of nanostructured α-Al2O3 ceramics irradiated with C+/H+ pulsed ion beams have been studied. The relationship between changes in the TL properties of ceramics and the formation of radiation defects under irradiation is discussed

Дистанционное и радиолокационное исследование ледника Левый Ирбисту (Южно-Чуйский хребет, Республика Алтай)

To determine changes of glacier No. 31 (SU5A15106031), happened in the beginning of the XXI century, satellite images, obtained from the Landsat-7, 8, 9 and Sentinel-2 satellites in different years, were analyzed. As a result, data on the glacier changes were obtained for the period from 2000 to 2022. During this time, the length of the main stream of the glacier decreased by 144 m (6.8%), and the total area of the entire glacier – by 0.089 km2 (9.7%). The rate of retreat of the glacier front varied from 2 to 15 m/year, on average – 6.5 m/year, and the glacier area decreased by on average of 0.004 km2/year. In 2022, the glacier consisted of two separate ice streams, with a total area of 0.823 km2 and a maximum length of 1.955 km. Aerial photography was carried out using a DJI Phantom 4 quadcopter. A high-resolution orthophotoplan (±5 cm), a digital terrain model, a three-dimensional model of the surface of the glacier tongue and adjacent territories, with a total area of 0.25 km2, were made. Radar sounding was performed by the Python-3 georadar in two configurations: at frequencies 50 and 100 MHz. Two cross-sections of the glacier were constructed from the radar data: one was taken at a frequency of 100 MHz, and the second at both – 50 MHz and 100 MHz. The analysis of the radiogram of these profiles made possible to reveal that the larger thickness of the glacier in the study area was measured along the left side of the glacier tongue, the maximum recorded thickness was equal to 66 mНа основе данных ДЗЗ за 2000–2022 гг. выявлено изменение малого ледника № 31 (SU5A15106031), расположенного на Южно-Чуйском хребте Центрального Алтая. За это время ледник сократился на 144 м (на 6.8%) и потерял 0.089 км2 (9.7%) своей площади. Приведены результаты аэрофотосъёмки и радиолокационного зондирования нижней части языка ледника, выполненных в 2022 г

CATHODO- AND THERMOLUMINESCENCE OF α-Al2O3 SINGLE CRYSTALS IRRADIATED WITH Fe10+ PULSED ION BEAM

PCL and TL of α-Al2O3 single crystals irradiated with various doses of Fe10+ pulsed ion beam were studied. The formation of F-type centers in irradiated crystals was observed. A similar nonmonotonic dependence of PCL of F-centers and TL on the value of the radiation dose was found

Predictors of rethrombosis and death in patients with COVID-19 after lower limb arterial thrombectomy for acute ischemia

Aim. To identify predictors of rethrombosis and death in patients with coronavirus disease (COVID-19) after thrombectomy for acute lower limb ischemia.Material and methods. For the period from April 2020 to January 2022, 189 pa tients with acute arterial lower limb thrombosis and acute lower limb ischemia were included in this study. In all cases, a positive polymerase chain reaction test for SARS-CoV-2 was obtained. According to chest multislice computed tomography, bilateral multisegmental pneumonia was identified as follows: 76 patients — grade 2 (25-50% of lung tissue involvement); 52 patients — grade 3 (50-75%); 61 patients — grade 4 (>75%). Breathing was carried out as follows: in 88 patients — spontaneous; in 42 — with oxygen administration by nasal cannula; 26 — non-invasive ventilation; 33 had artificial ventilation. All acute arterial thromboses developed within the hospital at 4,5±1,5 days after hospitalization. The time between the onset to diagnosis verification was 27,8±5,0 min. The revascularization strategy was established by a multidisciplinary team meeting. The interval between the development of acute ischemia symptoms and surgery was 45,9±6,3 minutes. Thrombectomy was performed according to the standard technique, under local and/or intravenous anesthesia, using 3F-7F Fogarty catheters.Results. Retrombosis developed in 80,4% of cases 6,4±5,1 hours after surgery. In 59,8% of cases, retrombectomy turned out to be ineffective and the patient underwent limb amputation. In 65,6% of patients, a death was established due to multiple organ dysfunction. Among them, limb amputation was performed in 103 patients. Binary logistic regression identified following predictors of retrombosis/ death: age over 70 years (odds ratio (OR), 30,73; 95% confidence interval (CI), 11,52-33,7), obesity (OR, 15,53; 95% CI, 6,41-78,19), diabetes (OR 14,21; 95% CI, 5,86-49,21), vasopressor support (OR 8,55; 95% CI, 4,94-17,93), mechanical ventilation (OR 7,39; 95% CI, 4,81-16,52).Conclusion. Predictors of retrombosis and death in patients with COVID-19 after lower limb arterial thrombectomy are age over 70 years, obesity, diabetes, vasopressor support, and mechanical ventilation

Исследование роли полиморфных вариантов генов цитокинов в развитии бронхиальной астмы в Республике Башкортостан

Summary. Asthma is one of the most common, severe and debilitating multifactorial diseases resulting from complex interaction between genes and environ mental factors. The aim of the present work was to analyze the association between cytokine gene polymorphisms and development of asthma in population of the Republic of Bashkortostan. A total of 638 patients with asthma and 366 healthy individuals were recruited in our investigation. In summary, the study of cytokine gene polymorphisms and genegene interaction suggested an important role of TNFA, IL4, CCL11 and IL13 genepolymorphisms in the development of asthma in Bashkortostan population.Резюме. Бронхиальная астма (БА) является одним из наиболее распространенных, тяжелых и инвалидизирующих многофакторных заболеваний, развивающихся при тесном взаимодействии генетических и средовых факторов риска. Целью настоящей работы явился анализ ассоциации полиморфных вариантов генов цитокинов с развитием бронхиальной астмы в Республике Башкортостан. Материалом для исследования служили образцы ДНК 638 неродственных индивидов, больных БА, и 366 практически здоровых индивидов контрольной группы. Проведенное исследование полиморфных вариантов генов цитокинов (IL4, IL4RA, IL1B, IL1RA, IL10, IL13, CCL11, TNFA) и межгенных взаимодействий показало, что полиморфные варианты генов цитокинов TNFA, IL4, CCL11 и IL13 вносят вклад в формирование генетической предрасположенности к БА в Республике Башкортостан