543 research outputs found

    Eclipses of the inner satellites of Jupiter observed in 2015

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    During the 2014-2015 campaign of mutual events, we recorded ground-based photometric observations of eclipses of Amalthea (JV) and, for the first time, Thebe (JXIV) by the Galilean moons. We focused on estimating whether the positioning accuracy of the inner satellites determined with photometry is sufficient for dynamical studies. We observed two eclipses of Amalthea and one of Thebe with the 1 m telescope at Pic du Midi Observatory using an IR filter and a mask placed over the planetary image to avoid blooming features. A third observation of Amalthea was taken at Saint-Sulpice Observatory with a 60 cm telescope using a methane filter (890 nm) and a deep absorption band to decrease the contrast between the planet and the satellites. After background removal, we computed a differential aperture photometry to obtain the light flux, and followed with an astrometric reduction. We provide astrometric results with an external precision of 53 mas for the eclipse of Thebe, and 20 mas for that of Amalthea. These observation accuracies largely override standard astrometric measurements. The (O-C)s for the eclipse of Thebe are 75 mas on the X-axis and 120 mas on the Y-axis. The (O-C)s for the total eclipses of Amalthea are 95 mas and 22 mas, along the orbit, for two of the three events. Taking into account the ratio of (O-C) to precision of the astrometric results, we show a significant discrepancy with the theory established by Avdyushev and Ban'shikova in 2008, and the JPL JUP 310 ephemeris.Comment: 7 pages, 10 figures, 4 table

    Unbounded p-Convergence in Lattice-Normed Vector Lattices

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    A net xα in a lattice-normed vector lattice (X, p, E) is unbounded p-convergent to x ∈ X if p(| xα− x| ∧ u) → o 0 for every u ∈ X+. This convergence has been investigated recently for (X, p, E) = (X, |·|, X) under the name of uo-convergence, for (X, p, E) = (X, ‖·‖, ℝ) under the name of un-convergence, and also for (X, p, ℝX ′) , where p(x)[f]:= |f|(|x|), under the name uaw-convergence. In this paper we study general properties of the unbounded p-convergence.Article Pre-prin

    Cytomorphometric indicators of the gingiva epitheliocytes of patients with ischemic heart disease on the background of taking acetylsalicylic acid

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    The aim is to study the cytological and morphometric characteristics of gingiva epitheliocytes in patients with IHD who are constantly taking ASA drugs. To determine the dental status, 92 patients aged 40-60 years who are on outpatient treatment of IHD were examined. An in-depth scientific study was conducted and the results of cytomorphometric indicators of the gingiva epitheliocytes of patients with ischemic heart disease, constantly taking acetylsalicylic acid drugs, were presente

    Gas dynamics of stationary supersonic gas jets with inert particles exhausting into a medium with low pressure

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    Issues related to the development of tools for mathematical modeling of stationary supersonic flows of an ideal compressible gas with inert particles are considered. A mathematical model is constructed that describes the flow of an inviscid compressible gas with inert particles in a jet flowing from an axisymmetric nozzle into a flooded space. Provided that the flow is supersonic along one of the spatial coordinates, the Euler equations are hyperbolic along this coordinate. For numerical calculations of the gas flow field, the finite volume method and the marching method are used. For integration over the marching direction, the three-step Runge–Kutta scheme is used. The procedure for calculating the flows includes the reconstruction of the values of the desired functions on the faces of the control volumes from the average values over the control volumes and the solution of the problem of the decay of an arbitrary discontinuity (the Riemann problem). The Lagrangian method of test particles is used to describe the dispersed phase. The effects of the reverse influence of particles on the flow of the carrier gas are not taken into account. The effects of viscosity and rarefaction of the gas flow are taken into account only when the gas interacts with particles. Calculation of the trajectories of inert particles is carried out in a known flow field of the carrier gas. The motion trajectories of discrete inclusions in jet flows with strong underexpansion are presented. The influence of the particle size and the coordinates of the particle entry point into the flow on the features of their transfer by the jet stream are discussed. Efficient means of numerical simulation of stationary supersonic flows of an ideal compressible gas with particles in nozzles and jets have been developed. The calculation results are of interest for studying supersonic gas suspension flows around bodies and for calculating oblique shock waves

    Алгоритм и программный комплекс оптимального технологического проектирования простых ректификационных колонн

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    Objectives. The formalized problem of the optimal design of distillation column systems belongs to the class of mixed integer nonlinear program problems. Discrete search variables are the number of trays in the rectifying and stripping sections of columns, whereas the continuous ones are the operating modes of columns. This study aimed to develop an algorithm and a software package for the optimal technological design of a system of simple distillation columns based on the criterion of total reduced capital and energy costs using rigorous mathematical distillation models.Methods. The solution to this problem is based on the branch and bound method. A computer model of the distillation column system was developed in the environment of the Aspen Hysys software package. The Inside–Out module was used as the distillation model. The developed algorithm is implemented in the software environment of the Matlab mathematical package. To solve the conditional optimization problem, a sequential quadratic programming method-based model was used. The interaction between software add-ins in Matlab and Aspen Hysys is implemented using a Component Object Model interface.Results. Approaches to obtain the lower and upper bounds of the optimality criterion and the branching method for the implementation of the branch and bound method have been developed. In addition, an algorithm for the optimal design of a distillation column of a given topology based on the branch and bound method has been developed. Furthermore, using Matlab, a software package that implements the developed algorithm and is integrated with the universal modeling software AspenHysys has been created.Conclusions. An algorithm and a software package have been developed and implemented that allows automating the design process of distillation column systems and integration with advanced mathematical programming packages, respectively. The performance of the algorithm and software package has been evaluated using the optimal design of the debutanization column as an example.Цели. Формализованная задача оптимального проектирования систем ректификационных колонн относится к классу задач дискретно-непрерывного нелинейного программирования. Дискретными поисковыми переменными являются число тарелок в укрепляющей и исчерпывающей частях колонн, а непрерывными – режимы работы колонн. Цель работы – разработать алгоритм и программный комплекс оптимального технологического проектирования системы простых тарельчатых ректификационных колонн по критерию суммарных приведенных капитальных и энергетических затрат на основе строгих математических моделей ректификации.Методы. Решение поставленной задачи базируется на методе ветвей и границ. Компьютерная модель системы ректификационных колонн построена в среде программного комплекса Aspen Hysys. В качестве модели ректификации использован модуль Inside-Out. Разработанный алгоритм реализован в программной среде математического пакета Matlab. Для решения задачи условной оптимизации использован модуль, основанный на методе последовательного квадратичного программирования. Взаимодействие программной надстройки, построенной в Matlab, c Aspen Hysys реализовано c помощью COM-интерфейса.Результаты. Разработаны подходы к получению нижних и верхних границ критерия оптимальности и способ ветвления при реализации метода ветвей и границ. Разработан алгоритм оптимального проектирования ректификационной колонны заданной топологии на основе метода ветвей и границ. В математическом пакете Matlab создан программный комплекс, реализующий предложенный алгоритм и интегрированный с универсальной моделирующей программной AspenHysys.Выводы. Разработан алгоритм и реализован программный комплекс, позволяющий автоматизировать процесс проектирования систем ректификационных колонн и интеграцию с передовыми пакетами математического программирования. Работоспособность алгоритма и программного комплекса апробирована на примере оптимального проектирования колонны дебутанизации

    Оценка качества технического обслуживания средств РТОП и ЭС

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    This article deals with the assessment model of the quality of preventive maintenance of the means of radiotechnical flight support and telecommunications which is based on the evaluation of the availability while minimizing the discount-ed value of the analyzed processes.В работе рассматривается модель оценки качественного уровня профилактического обслуживания средств радиотехнического обеспечения полетов и электросвязи, в основу которой положена оценка коэффициента готовности при минимизации дисконтируемой стоимости анализируемых процессов

    Gene Polymorphism of Toll-Like Receptors in Chickenpox Patients: Observational Cohort Study

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    Background. Toll-like receptors (TLR) play a key role in the innate immune system, as they are the fi rst to recognize a foreign agent and initiate the human body defense mechanism. At present, the role of toll-like receptors in predicting infectious diseases requires further investigation.Objectives. To study TLR3 (Phe412Leu), TLR9 (A2848G) and TLR9 (T1237C) polymorphisms in healthy individuals and chickenpox patientsMethods. An observational cohort study involved 201 conscripted soldiers of Caucasian race, aged between 18 and 24, who was born in) and served in Zabaykalsky Krai. All of them agreed to participate voluntarily. The main group was represented by 105 males who received treatment at a military hospital with a diagnosis of chickenpox in 2019. The control group consisted of 96 healthy conscripts. The study was carried out on the basis of Chita State Academy of Medicine, Russia, and included a physical examination, anthropometry, determination of SNP genes by PCR. Amplifi cation of TLR3 and TLR9 gene fragments was carried out by means of thermocycler BIS-М111. IBM SPSS Statistics 25.0 (International Business Machines Corporation, License No. Z125-3301-14, USA) was used for statistical processing of the results.Results. A total of 354 people were screened, 87 of them did not meet the inclusion criteria and 19 refused to participate in the study. 134 males were excluded in the process, 47 of which appeared to have an exacerbation of chronic diseases, 21 were not of Caucasian race, 64 were not born in Zabaykalsky Krai, and 2 did not meet the age criteria. Totally, the study included 201 conscripted soldiers. The study groups were established as follows: chickenpox patients (n = 105) and healthy individuals (controls, n = 96). The -412Leu allele was 1.8 times less frequent in the chickenpox group, with a frequency of 0.138, compared with 0.250 in healthy controls (Ȥ 2 = 8.11; p = 0.004). In the main group, allele -412Phe prevailed with a frequency of 0.862, whereas in the control group its frequency was 0.750 (χ2 = 8.11; p = 0.004). In patients group, the genoype Phe412Phe prevailed (75.2%), the genotype Leu412Leu was less common — 2.9% (Ȥ 2 = 7.09; p = 0.03). In the group of healthy individuals, the distribution of genotypes was as follows: Phe412Phe — 60.4%, Phe412Leu — 30.2%, Leu412Leu — 9.4% (Ȥ 2 = 7.09; ɪ = 0.03). Carriers of allele -412Phe (OR = 2.08 [CI95%: 1.25–3.47]) and genotype Phe412Phe (OR = 2.08 [CI95%: 1.14–3.80]) are more likely to develop chickenpox. The probability of developing the disease for persons having the major allele A of the genotype TLR9 (Ⱥ2848G) is 0.29 [CI95%: 0.19– 0.43], for individuals with the mutant allele G of the genotype TLR9 (Ⱥ2848G) — 3.50 [CI95%: 2.32–5.29]. The prevalence of TLR9 (T1237C) in the main group was not signifi cantly different from that in the control group (p > 0.05). The probability of developing the disease for persons having the major allele A is 0.29 [95% CI 0.19–0.43], for carriers of the mutant allele G — 3.50 [95% CI 2.32-5.29]. When analyzing SNP TLR9 (A2848G), it was found that allele G prevailed with a frequency of 0.614, and allele A — with a frequency of 0.386, which is 1.9 times less than in the control group (Ȥ 2 = 36.67; p < 0.001). In patients group, homozygotes AA were found in 9.5% of cases, heterozygotes AG — in 58.1%, the rest cases were homozygous variants GG (Ȥ 2 = 40.11; p < 0.001). In the control group, all possible genotypes with a predominance of the heterozygous genotype AG were identifi ed and comprised 47.9%. When assessing the relative risk of gene variation associations connected with the development of chickenpox, we found that the polymorphism of genes TLR9 (A2848G) AG/GG increases the risk of the development of disease caused by varicella virus in the studied category by 3.4 times, and the polymorphism TLR3 (Phe412Leu) Phe/ Phe — by 1.42 times. The ROC analysis was carried out, the area under curve was 0.77 (95% CI0.70–0.83); p < 0.001; specifi city — 0.62; sensitivity — 0.8. The developed model, being a relatively good identifi er, has satisfactory properties as a discriminator.Conclusion. Our study suggests that allele -412Phe and homozygous variant Phe412Phe of gene TLR3 (Phe412Leu), as well as allele G and homozygous variant GG of gene TLR9 (A2848G) predispose to chickenpox development. Meanwhile, the allele -412Leu of gene TLR3 (Phe412Leu), allele A, and homozygous variant AA of gene TLR9 (A2848G) reduce the probability of chickenpox development

    Strong tidal dissipation in Saturn and constraints on Enceladus' thermal state from astrometry

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    Tidal interactions between Saturn and its satellites play a crucial role in both the orbital migration of the satellites and the heating of their interiors. Therefore constraining the tidal dissipation of Saturn (here the ratio k2/Q) opens the door to the past evolution of the whole system. If Saturn's tidal ratio can be determined at different frequencies, it may also be possible to constrain the giant planet's interior structure, which is still uncertain. Here, we try to determine Saturn's tidal ratio through its current effect on the orbits of the main moons, using astrometric data spanning more than a century. We find an intense tidal dissipation (k2/Q= (2.3 \pm 0.7) \times 10-4), which is about ten times higher than the usual value estimated from theoretical arguments. As a consequence, eccentricity equilibrium for Enceladus can now account for the huge heat emitted from Enceladus' south pole. Moreover, the measured k2/Q is found to be poorly sensitive to the tidal frequency, on the short frequency interval considered. This suggests that Saturn's dissipation may not be controlled by turbulent friction in the fluid envelope as commonly believed. If correct, the large tidal expansion of the moon orbits due to this strong Saturnian dissipation would be inconsistent with the moon formations 4.5 Byr ago above the synchronous orbit in the Saturnian subnebulae. But it would be compatible with a new model of satellite formation in which the Saturnian satellites formed possibly over longer time scale at the outer edge of the main rings. In an attempt to take into account for possible significant torques exerted by the rings on Mimas, we fitted a constant rate da/dt on Mimas semi-major axis, also. We obtained an unexpected large acceleration related to a negative value of da/dt= -(15.7 \pm 4.4) \times 10-15 au/day
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