Foamed glass-ceramic materials based on oil shale by-products

The feasibility and features of the production of foamed glass-ceramic materials based on oil shale ash were investigated. The optimal regime of synthesis found involved the following steps: glass fusion at 1400 °C, preparation of the glass powders and blending with the foaming agent. The foaming was carried out at 900 to 920 °C with a further one-stage crystallization at 790 to 820 °C. It was noted that the admixture of calcium carbonate, as a foaming agent, changed the phase composition of the resulting glass-ceramics by an increased rate of the crystallization process and the intensive formation of gehlenite simultaneously with diopside

Additional spectroscopic redshift measurements for galaxy clusters from the First Planck Catalogue

We present the results of spectroscopic redshift measurements for the galaxy clusters from the first all-sky Planck catalogue of the Sunyaev-Zeldovich sources, that have been mostly identified by means of the optical observations performed previously by our team (Planck Collaboration, 2015a). The data on 13 galaxy clusters at redshifts from z=~0.2 to z=~0.8, including the improved identification and redshift measurement for the cluster PSZ1 G141.73+14.22 at z=0.828, are provided. The measurements were done using the data from Russian-Turkish 1.5-m telescope (RTT-150), 2.2-m Calar Alto Observatory telescope, and 6-m SAO RAS telescope (Bolshoy Teleskop Azimutalnyi, BTA).Comment: published in Astronomy Letter

Модели сигналов импульсной РЛС, принимаемых однопозиционной станцией радиотехнической разведки на наземных трассах

Излагаются основы однопозиционного пассивного метода определения координат источника радиоизлучения путем использования множества отражений излученных сигналов от естественных и искусственных образований на трассе распространения радиоволн. Алгоритм основан на сравнении координат возможных отражателей, нанесенных на карту местности, с координатами, вычисленными по измеренным пеленгам источников отражений и задержек отраженных сигналов относительно прямого. Приводятся данные радиофизического эксперимента по изучению отражений, выполненного в трехсантиметровом диапазоне волн, позволяющие оценить пригодность принимаемых сигналов для реализации метода. Принимаемые сигналы представлены в виде простейших математических моделей. Показано, что их статистический характер не препятствует реализации метода

Vertical Structure of the Outer Accretion Disk in Persistent Low-Mass X-Ray Binaries

We have investigated the influence of X-ray irradiation on the vertical structure of the outer accretion disk in low-mass X-ray binaries by performing a self-consistent calculation of the vertical structure and X-ray radiation transfer in the disk. Penetrating deep into the disk, the field of scattered X-ray photons with energy $E\gtrsim10$\,keV exerts a significant influence on the vertical structure of the accretion disk at a distance $R\gtrsim10^{10}$\,cm from the neutron star. At a distance $R\sim10^{11}$\,cm, where the total surface density in the disk reaches $\Sigma_0\sim20$\,g\,cm$^{-2}$, X-ray heating affects all layers of an optically thick disk. The X-ray heating effect is enhanced significantly in the presence of an extended atmospheric layer with a temperature $T_{atm}\sim(2\div3)\times10^6$\,K above the accretion disk. We have derived simple analytic formulas for the disk heating by scattered X-ray photons using an approximate solution of the transfer equation by the Sobolev method. This approximation has a $\gtrsim10$\,% accuracy in the range of X-ray photon energies $E<20$\,keV.Comment: 19 pages, 8 figures, published in Astronomy Letter

Recognition of ground objects on a radar image using convolutional neural network

Поступила: 09.12.2021. Принята в печать: 24.03.2022.Received: 09.12.2021. Accepted: 24.03.2022.Рассматриваются методы распознавания наземных объектов на радиолокационном изображении, полученном с помощью радиолокатора с синтезированной апертурой. Приводятся результаты моделирования распознавания наземных объектов с применением сверточной нейронной сети. Приведено сравнение зависимости времени распознавания от количества наземных объектов на РЛИ для нейросетевого и корреляционного методов.In this paper, methods of recognizing ground objects on a radar image obtained using a synthesized aperture radar are considered. The results of modeling the recognition of ground objects using a convolutional neural network are presented. The comparison of the dependence of the recognition time on the number of ground objects on the radar for neural network and correlation methods is given

Концентрация мочевой кислоты и показатели липопероксидации клеточных мембран при дыхательной гипоксии у детей с острыми бронхолегочными заболеваниями

A comparative analysis of uric acid level in children with acute bronchopulmonary diseases (80 pneumonic and 65 bronchitis patients) revealed a clear correlation between its concentration and a respiratory failure severity, and a hypoxaemia level as well. This fact confirms a role of hypoxia in purine nucleotides catabolism, resulting in uric acid production. The relation established between a uric acid concentration and lipid peroxidation products content proved the role of purine metabolism acute disorders in a lipid peroxidation enhancement caused by a xanthinoxidase activation that had been shown experimentally. An application of metronidazole as a xanthinoxidase inhibitor in severe pneumonia and Riboxine as a source of inosine in obstructive bronchitis with severe respiratory disorders led to shortening of a dyspnoe period and of length of stay in an intensive care unit and also facilitated an inhibition of excessive lipid peroxidation of cell membranes.Сравнительный анализ уровня мочевой кислоты у детей с острыми бронхолегочными заболеваниями (80 с пневмонией и 65 с бронхитом) показал четкую зависимость ее концентрации от степени дыхательной недостаточности и уровня гипоксемии, что явилось подтверждением роли гипоксии в катаболизме пуриновых нуклеотидов, конечным продуктом которого и является мочевая кислота. Установленная связь между концентрацией мочевой кислоты и содержанием продуктов липопероксидации подтвердила доказанную в эксперименте роль нарушения пуринового обмена в усилении опосредованного активацией ксантиноксидазы, перекисного окисления липидов. Применение метронидазола, как ингибитора ксантиноксидазы при тяжелых формах пневмонии и рибоксина, как источника инозина, при обструктивных формах бронхита с тяжелыми дыхательными расстройствами сокращало период одышки, время нахождения пациентов в отделении реанимации и способствовало торможению чрезмерной липопероксидации клеточных мембран

Several New Active Galactic Nuclei Among X-ray Sources Detected by INTEGRAL and SWIFT Observatories

We present the results of the optical identifications of a set of X-ray sources from the all-sky surveys of INTEGRAL and SWIFT observatories. Optical data were obtained with Russian-Turkish 1.5-m Telescope (RTT150). Nine X-ray sources were identified as active galactic nuclei (AGNs). Two of them are hosted by nearby, nearly exactly edge-on, spiral galaxies MCG -01-05-047 and NGC 973. One source, IGR J16562-3301, is most probably BL Lac object (blazar). Other AGNs are observed as stellar-like nuclei of spiral galaxies, with broad emission lines in their spectra. For the majority of our hard X-ray selected AGNs, their hard X-ray luminosities are well-correlated with the luminosities in [OIII],5007 optical emission line. However, the luminosities of some AGNs deviate from this correlation. The fraction of these objects can be as high as 20%. In particular, the flux in [OIII] line turns to be lower in two nearby edge-on spiral galaxies, which can be explained by the extinction in their galactic disks.Comment: 9 pages, 3 figures, accepted for publication in Astronomy Letters, the original text in Russian can be found at http://hea.iki.rssi.ru/~rodion/poptid.pd