Eight exoplanet candidates in SAO survey

Here we present eight new candidates for exoplanets detected by the transit method at the Special Astrophysical Observatory of the Russian Academy of Sciences. Photometric observations were performed with a 50-cm robotic telescope during the second half of 2020. We detected transits with depths of $\Delta m = 0.056-0.173^m$ and periods $P = 18.8^h-8.3^d$ in the light curves of stars with magnitudes of $m = 14.3-18.8^m$. All considered stars are classified as dwarfs with radii of $R_* = 0.4-0.6 R_{sun}$ (with the uncertainty for one star up to $1.1 R_{sun}$). We estimated the candidate radii (all are greater than 1.4 times the Jovian radius), semi-major axes of their orbits ($0.012-0.035 AU$), and other orbital parameters by modelling. We report the light curves with transits for two stars obtained in 2022 based on individual observations.Comment: 16 pages, 14 figures, 3 table

Copper stearate as a catalyst for improving the oxidation performance of heavy oil in in-situ combustion process

© 2018 Elsevier B.V. Copper stearate was applied as a catalyst for the oxidation of heavy oils. The catalytic effect was investigated by high-pressure differential scanning calorimetry (HP-DSC) and accelerating rate calorimetry (ARC). The results showed that copper stearate significantly improved the oxidation performance including decreasing activation energies, enhancing combustion efficiency of coke, and reducing induction time and ignition temperature. CuO nanoparticles were in-situ formed due to the decomposition of copper stearate. To understand the catalytic mechanism, the catalytic effect of copper stearate was compared with nickel stearate, iron stearate and CuO. Furthermore, the existed form and transition of copper stearate during the oxidation process of crude oil were investigated using thermogravimetric analyser coupled with FTIR-spectrometer (TG-FTIR), HP-DSC, X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results indicated that copper stearate and in-situ formed CuO nanoparticles played their catalytic roles as a homogeneous and heterogenous catalyst in low and high-temperature ranges, respectively. It was believed that the high catalytic activity of CuO can be not only attributed to those well-known catalytic mechanisms, but also benefits from the well-distribution of both copper stearate and in-situ formed CuO nanoparticles

АЛГОРИТМЫ ПОСТРОЕНИЯ ДЕСКРИПТОРОВ ЛОКАЛЬНЫХ ОСОБЕННОСТЕЙ ИЗОБРАЖЕНИЙ НА БАЗЕ МНОГОКОЛЬЦЕВЫХ НЕПАРАМЕТРИЧЕСКИХ ПРЕОБРАЗОВАНИЙ

Application of nonparametric transformations for construction of local image features descriptors is considered. An approach based on scalable Bresenham circles for multiring nonparametric transformations is proposed. A problem of finding characteristic points (corners) in images is solved using two rings of small radius. Then, considering rings of greater radius a final decision is made concerning local features under investigation. Testing results of proposed local descriptors have demonstrated their competitiveness with known descriptors.Рассматривается применение непараметрических преобразований при построении дескрипторов локальных особенностей изображений. Предлагаются подходы, в основу которых положены алгоритмы построения масштабируемых дискретных окружностей по Брезенхему, для многокольцевых непараметрических преобразований. Приводятся результаты моделирования предложенного подхода к построению локальных дескрипторов на тестовой базе по сравнению с известными дескрипторами SURF, ORB, BRISK, FREAK

Aging Studies for the Large Honeycomb Drift Tube System of the Outer Tracker of HERA-B

The HERA-B Outer Tracker consists of drift tubes folded from polycarbonate foil and is operated with Ar/CF4/CO2 as drift gas. The detector has to stand radiation levels which are similar to LHC conditions. The first prototypes exposed to radiation in HERA-B suffered severe radiation damage due to the development of self-sustaining currents (Malter effect). In a subsequent extended R&D program major changes to the original concept for the drift tubes (surface conductivity, drift gas, production materials) have been developed and validated for use in harsh radiation environments. In the test program various aging effects (like Malter currents, gain loss due to anode aging and etching of the anode gold surface) have been observed and cures by tuning of operation parameters have been developed.Comment: 14 pages, 6 figures, to be published in the Proceedings of the International Workshop On Aging Phenomena In Gaseous Detectors, 2-5 Oct 2001, Hamburg, German

Влияние молекулярной массы и молекулярно-массового распределения на реологические свойства эпоксидных олигомеров

The molecular characteristics of diane epoxy oligomers produced by industries: DER-330, ED-20, ED-16, ED-8 is studied. The fractional composition was identified. The viscosity characteristics epoxy resins at different temperature are studied the entire range of molecular weight and molecular-mass distribution.Исследованы молекулярные характеристики диановых эпоксидных олигомеров марок DER-330, ЭД-20, ЭД-16, ЭД-8, выпускаемых промышленностью. Определены их фракционные составы. Во всем диапазоне молекулярной массы и молекулярно-массового распределения изучены вязкостные характеристики эпоксидных олигомеров при разных температурах

Spectacular enhancement of the thermal and photochemical stability of mapbi3 perovskite films using functionalized tetraazaadamantane as a molecular modifier

Perovskite solar cells represent a highly promising third-generation photovoltaic tech-nology. However, their practical implementation is hindered by low device operational stability, mostly related to facile degradation of the absorber materials under exposure to light and elevated temperatures. Improving the intrinsic stability of complex lead halides is a big scientific challenge, which might be addressed using various “molecular modifiers”. These modifiers are usually rep-resented by some additives undergoing strong interactions with the perovskite absorber material, resulting in enhanced solar cell efficiency and/or operational stability. Herein, we present a deriva-tive of 1,4,6,10-tetraazaadamantane, NAdCl, as a promising molecular modifier for lead halide perovskites. NAdCl spectacularly improved both the thermal and photochemical stability of methy-lammonium lead iodide (MAPbI3 ) films and, most importantly, prevented the formation of metallic lead Pb0 as a photolysis product. NAdCl improves the electronic quality of perovskite films by healing the traps for charge carriers. Furthermore, it strongly interacts with the perovskite framework and most likely stabilizes undercoordinated Pb2+ ions, which are responsible for Pb0 formation under light exposure. The obtained results feature 1,4,6,10-tetraazaadamantane derivatives as highly promising molecular modifiers that might help to improve the operational lifetime of perovskite solar cells and facilitate the practical implementation of this photovoltaic technology. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.This work was supported by Russian Science Foundation (project No. 19-73-30020). The XPS measurements were supported by the Ministry of Education and Science of the Russian Federation (project FEUZ-2020-0060), Theme ‘Electron’, no. AAAA-A18-118020190098-5 and Russian Foundation for Basic Research (project No. 21-52-52002)

The Outer Tracker Detector of the HERA-B Experiment Part I: Detector

The HERA-B Outer Tracker is a large system of planar drift chambers with about 113000 read-out channels. Its inner part has been designed to be exposed to a particle flux of up to 2.10^5 cm^-2 s^-1, thus coping with conditions similar to those expected for future hadron collider experiments. 13 superlayers, each consisting of two individual chambers, have been assembled and installed in the experiment. The stereo layers inside each chamber are composed of honeycomb drift tube modules with 5 and 10 mm diameter cells. Chamber aging is prevented by coating the cathode foils with thin layers of copper and gold, together with a proper drift gas choice. Longitudinal wire segmentation is used to limit the occupancy in the most irradiated detector regions to about 20 %. The production of 978 modules was distributed among six different laboratories and took 15 months. For all materials in the fiducial region of the detector good compromises of stability versus thickness were found. A closed-loop gas system supplies the Ar/CF4/CO2 gas mixture to all chambers. The successful operation of the HERA-B Outer Tracker shows that a large tracker can be efficiently built and safely operated under huge radiation load at a hadron collider.Comment: 28 pages, 14 figure

Эффективность и безопасность ингаляционных глюкокортикоидов у больных бронхиальной астмой

The aim of this study was to investigate efficacy and safety of inhaled glucocorticoids (budesonide and beclometazone dipropionate) in bronchial asthma (BA) patients. Nineteen patients (8 males and 11 females) with moderate BA were observed. They have received these drugs for 9 months. The patients demonstrated significantreduction in asthmatic attacks frequency and in need for short-acting β2-agonists inhalations during the treatment. The reliable increase of bronchial passability parameters was registered only over 3 months after the starting of the therapy and was maintained up to the end of the observation period. Cortizol blood level, magnesium, calcium and potassium concentrations in serum, erythrocytes and in daily urine, serum osteocalcine content, lumbar vertebra density (L2-L4) did not differ significantly after 3, 6 and 9 months of treatment compared with the initial parameters.Thus, the inhaled glucocorticoids possess high clinical activity in asthmatic patients’ treatment. These drugs should be prescribed for at least 3 months. The inhaled glucocorticoids used in average therapeutic doses do not effect negatively on cortizol blood level, mineral metabolism and osseous tissue.Целью настоящей работы явилось исследование эффективности и безопасности ингаляционных глюкокортикоидов (будесонида и беклометазона дипропионата) у больных бронхиальной астмой (БА). Под наблюдением находилось 19 пациентов (8 мужчин, 11 женщин) с БА средней тяжести течения, получавших эти препараты в течение 9 месяцев. В процессе лечения у обследованных отмечалось существенное снижение частоты приступов удушья и потребности в ингаляциях β2-адреномиметиков короткого действия. Достоверный прирост показателей бронхиальной проходимости отмечался лишь через 3 месяца после начала терапии и сохранялся до конца периода наблюдения. Уровень кортизола в крови, концентрация  магния, кальция и калия в сыворотке крови,эритроцитах и суточной моче, содержание остеокальцина всыворотке, плотность костной ткани поясничных позвонков (L2-L4) через 3, 6 и 9 месяцев лечения существенно не отличались от исходных.Таким образом, ингаляционные глюкокортикоиды обладают высокой клинической эффективностью при лечении больных БА. Их следует назначать больным в течение как минимум 3 месяцев. Использованные топические стероиды в средних терапевтических дозах не обладают отрицательным влиянием на уровень кортизола, минеральный обмен и костную ткань

The Outer Tracker Detector of the HERA-B Experiment. Part II: Front-End Electronics

The HERA-B Outer Tracker is a large detector with 112674 drift chamber channels. It is exposed to a particle flux of up to 2x10^5/cm^2/s thus coping with conditions similar to those expected for the LHC experiments. The front-end readout system, based on the ASD-8 chip and a customized TDC chip, is designed to fulfil the requirements on low noise, high sensitivity, rate tolerance, and high integration density. The TDC system is based on an ASIC which digitizes the time in bins of about 0.5 ns within a total of 256 bins. The chip also comprises a pipeline to store data from 128 events which is required for a deadtime-free trigger and data acquisition system. We report on the development, installation, and commissioning of the front-end electronics, including the grounding and noise suppression schemes, and discuss its performance in the HERA-B experiment