Search

The development of the method of preventive protection for the purposes of safe operation of the ship’s electric power system in emergency situations associated with malfunctions of its elements that occur during operation is considered in the paper. It has been shown that the existing devices form a command to start an emergency diesel generator at the moment when the voltage on the main switchboard busbars disappears. This circumstance causes a break in the power supply of responsible consumers of electric energy for a time equal to the start time of the emergency source. At the same time, the vessel loses control, and in most cases, the course. In this regard, it has been paid special attention in the paper to the development of a method for the preventive start of an emergency diesel generator, in which the launch command is formed before the vessel is de-energized, but with a real threat of this event. The conditions under which the preventive start of an emergency diesel generator should be carried out are formulated. Within the framework of the proposed approach, the energy state of the entire ship’s electric power system is predicted in the case of a decrease in its generating capacity, and, if necessary, a command to start an emergency source of electric energy is formed. At the same time, the most dangerous situation develops at a time when, in case of a failure of the generator unit of the main power plant, preventive unloading of the network turns out to be ineffective. It has been shown that there are emergency modes of vessel operation, such as flooding or fire in the room of diesel generators, in which the probability of simultaneous failure of all main electricity sources at once is especially high. The application of the proposed method of preventive start-up of an emergency power source will allow, in case of failure of at least one of the generator units of the main power plant operating in parallel, flooding or fire on the ship, to carry out structural adaptation of the system in advance to the malfunction that has arisen and go into a partially operational state, bypassing the emergency situation. At the same time, the interruption in the power supply of responsible consumers ensuring the safety of the vessel operation will either be significantly reduced or it will not happen at all. A functional diagram of a simple device implementing the proposed approach in practice is presented. A brief description of his work is given.

The article describes the algorithm for calculating a distributor of hydraulic turbine, which includes three stages: calculation of the kinematic characteristics of the distributor of hydraulic turbine, strength calculation of the guide vane and calculation of the power characteristics of the drive. Software implementing the specified algorithm has been developed. The use of software in JSC TYAZHMASH (Syzran) made it possible to reduce the labor intensity and cost of designing a distributor of hydraulic turbine.

Possible approaches to solving the problem of operational identification of the technical condition of ship power plants are considered. It is shown that the means of technical diagnostics used on modern ships are intended only for effective maintenance and repair of power equipment and they are not adapted for timely provision of information on the technical condition of the ship’s power plant necessary to ensure preventive management in abnormal operating modes. The definition of operational identification of the technical condition as a process of technical diagnostics of a ship’s power plant for the purposes of preventive and emergency management of its technical condition is given. The provision is substantiated that the means of technical diagnostics should not only identify the inoperable state of the elements of the ship’s power plant, but also predict its functioning mode after the shutdown of the inoperable generator unit and provide information to the warning control equipment about the necessary adjustment of external conditions to ensure its trouble-free transition to a partially operational state. It is shown that, unlike existing diagnostic tools, the goal-setting of operational identification of the technical condition of a ship’s power plant dictates the need to take into account such an important factor as the rate of the controlled parameter change, to determine the probable time for this factor to reach its maximum permissible value. The necessity of mandatory identification of inoperable elements of a ship’s power plant and the implementation of control actions aimed at eliminating an emergency situation until the overload of operable units and disabling them by means of protection is substantiated. It is established that the information obtained as a result of identification will allow the decision-making preparation system to formulate recommendations to the maintenance personnel and the preventive protection system about the necessary impacts on the ship’s power plant in order to exclude emergency situations. The main reasons for the overload of the ship’s power supply system are analyzed, algorithms for the practical solution of the problem of operational identification of the technical condition of the ship’s power plant for cases related to the overload of serviceable machines due to the shutdown of inoperable units are developed.

In recent years, the oil and gas industries have been developing significantly. In this regard, there was a great need for the construction of main pipelines, which consist of pipes and connecting parts. The production of connecting parts of pipeline has not been studied enough to date. This article describes the process of stamping halves of stamped-welded elbows. During the stamping operation, the workpiece wall is thinned. The process of modeling this operation in a software of modeling by finite element method Deform-3D is described. The place of the greatest thinning of the wall was determined with the help of Deform-3D. The results of modeling and experimental production coincided. The main factors that may influence the degree of thinning were identified. Experimental calculations were performed in Deform-3D with a variation of these factors. As a result of the experiments carried out, the most significant factor was determined and an option was proposed to solve the problem of wall thinning. Solving this problem will help reduce the cost of production by 1.5 times.

Tracking Ultraviolet Setup (TUS) detector is a detector of ultraviolet (UV) radiation of the atmosphere in the wavelength range of 300–400 nm (near-ultraviolet) with high sensitivity (tens of photons emitted within the solid angle of 10–4 sr in 0.8 μs), which operated for a year and a half aboard the Lomonosov satellite. The TUS telescope had a multipurpose operational program, which made it possible to detect UV flashes from the shortest ones created by extensive air showers generated by cosmic rays to long ones, up to 1 s, created by meteors. Among these various phenomena, most often are flashes from lightning strikes, both directly creating a glow and causing the development of secondary discharges in the atmosphere, in the upper atmosphere and in the ionosphere. These discharges differ in both nature and phenomenology—in particular, they have different durations and luminosities.

It is shown that the a priori data on the atmospheric conditions, in addition to the climate’s characteristics, can enhance the efficiency of the algorithms for reconstructing the atmospheric profiles using satellite microwave radiometric observations. Such additional data are sought and their efficiency in remote sensing is estimated. The possibility of expanding the statistical approach by including new types of a priori data on the temperature and humidity of atmospheric conditions is discussed. It is demonstrated that the developed technique can be used to estimate the efficiency of using the following types of additional a priori data in the statistical regularization method: (i) the covariance matrix of the full vector of temperature and humidity variations within a vertical atmospheric column, (ii) the covariance matrix of the temperature and humidity variations within horizontal atmospheric strata, (iii) physical limits of the humidity variation amplitude, and (iv) statistically average model representations of the microwave radiation transfer parameters in the cloud layer.

In the paper, we investigate the gauge fields that are characterized by the existence of non-trivial integrals of motion for the Wong equations. For the gauge group 𝑆𝑈(2), the class of fields admitting only the isospin first integrals is described in detail. All gauge non-equivalent Yang–Mills fields admitting a linear integral of motion for the Wong equations are classified in the three-dimensional Euclidean space

The value of metal resistance against plastic deformation is an important parameter at designing of technological equipment and plastic deformation modes, since it determines considerably energy and power parameters during rolling process. Usually it is represented as dependence on deformation rate, value of accumulated deformation and temperature at which the deformation takes place. Application of such dependences usually gives a satisfactory coincidence with experimental data. However, the perfection of the rolling processes results in increase requirements to the calculation accuracy of the deformation parameters, including the value of metal resistance against plastic deformation. At the production of metal products and pipes, the processes in which a metal is subjected to multiple deformation, are widely used. One of the ways to increase the calculation accuracy of the value of metal resistance against deformation is the accounting of metal softening between their stages. Calculation of variation of the metal resistance value presented, accounting and without accounting the softening during pipes rolling at a mandrel in a four-stand continuous mill. It was shown that the softening could have a significant influence on the value of metal resistance against plastic deformation. Accounting the softening and various processes taking place along both the roller pass perimeter and the mill length, gives an actual picture of stress and deformation state of metal.

We present the first measurement of di-hadron angular correlations in electron-nucleus scattering. The data were taken with the CLAS detector and a 5.0 GeV electron beam incident on deuterium, carbon, iron, and lead targets. Relative to deuterium, the nuclear yields of charged-pion pairs show a strong suppression for azimuthally opposite pairs, no suppression for azimuthally nearby pairs, and an enhancement of pairs with large invariant mass. These effects grow with increased nuclear size. The data are qualitatively described by the GiBUU model, which suggests that hadrons form near the nuclear surface and undergo multiple-scattering in nuclei. These results show that angular correlation studies can open a new way to elucidate how hadrons form and interact inside nuclei, Comment: 6 pages, 4 figures

Copolymerization of styrene with methyl or butylmethacrylates in road petroleum bitumen is studied. The copolymerization of the comonomers selected proceeds in the bituminous medium according to the same laws as in the mass and depends on concentration of the methacrylates. Polymer–bitumen composites, which can be potentially used as structural polymeric materials, have been obtained and studied.

The problem of creating a hyper spectral optoelectronic system for observing natural and artificial objects by means of unmanned aerial vehicles (UAV) is considered. The structure and composition of the system that solves this problem are described. It is based on acousto-optic filters. The results of laboratory testing of the hyper spectrometer are presented.

This article presents the results of the effect of drawing speed on the strain rate and resistance to plastic deformation. The wire drawing on modern high speed wire drawing machines significantly increases the required amount of drawing dies. The influence of the technological parameters: speed drawing, half-angle of the die, wire diameter and a single strain on the rate of deformation of the metal. The influence of the technological parameters: speed drawing, half-angle of the die, wire diameter and a single strain on the rate of deformation of the metal. It is found that increasing the resistance to drawing dies and achieve passport velocities drawing, when selecting process parameters drawing guided by the principle of uniform strain over the cross section of the wire by matching the single strain with half-angle dies and friction coefficient on the formula given in the article.

The strength of abrasive wheels is one of the key factors affecting the performance of abrasive machining. The paper discusses ways to improve the strength of abrasive wheels. The stress-state mathematical model presented herein is a generalization of the existing models. It is used herein to find for the first time that there are numerous optimal combinations of the elastic modulus and reinforcing material density, which result in the same minimum value of the objective function. It is found out that increasing the radius of the reinforcing component while also optimizing the mechanical properties of its material may increase the permissible breaking speed of the wheel several times. We herein present a regression equation and a nomogram for finding the optimal combination of control factors. Conventional methods for testing the mechanical properties of materials, which have been proven reliable for testing metals and alloys, are not as reliable for testing abrasive materials, as the test results they generate are not sufficiently stable or accurate. We therefore propose an alternative method that does not require any special equipment or special studies.

At present, push benches are not currently used in Russia because the experience of their operation in the USSR gave negative results. The history of application of push benches and the possibility of extension of the assortment of produced pipes are discussed. We present the analysis of the available data on the productivity and assortment of contemporary push benches. The advantages and disadvantages of modern pipe-rolling plants with push benches in the current economic situation are considered. The comparison of the characteristics of reeling mills reveals numerous significant advantages of push benches over the continuous reeling mills.

This paper studies the temporal dynamics of power-line frequency electric and magnetic fields in Saint-Petersburg and environs. It is found that electromagnetic fields generated by high-voltage transmission lines (HVTL) constantly change, depending on their loading and weather conditions. The dependence on weather conditions involves both the direct effect of air electrical conductivity as a function of its humidity, and indirect effects including the dependence of energy consumption on temperature and also the correlations between meteorological characteristics. An attempt has been made to evaluate the role of influencing factors.

Model organism studies are widely implemented in biomedical research fields. Zebrafish is a common and convenient model organism. To provide in vivo investigation of living zebrafish the non-invasive imaging methods are implemented. Hyperspectral imaging utilizing acousto-optic tunable filters is a perspective modality for zebrafish embryos and larvae automated observation. In this paper, the hyperspectral microscope based on the acousto-optical tunable filter is described. Using the hyperspectral image arrays obtained with the described setup, the K-means clustering algorithm is tested. The results obtained for different number of clusters are presented and discussed.

The way of the lateral resolution improvement for 3D nanorelief measurement is proposed. Algorithm for digital processing of measurement data based on deconvolution operation using Wiener filtration is presented. Results of theoretical researches, numerical and optical experiments are given.

The TUS space experiment is aimed at studying energy and arrival distribution of UHECR at E > 7 × 1019 eV by using the data of EAS fluorescent radiation in atmosphere. The TUS mission was launched at the end of April 2016 on board the dedicated “Lomonosov” satellite. The TUSSIM software package has been developed to simulate performance of the TUS detector for the Fresnel mirror optical parameters, the light concentrator of the photo detector, the front end and trigger electronics. Trigger efficiency crucially depends on the background level which varies in a wide range: from 0.2 × 106 to 15 × 106 ph/( m 2 μ s sr) at moonless and full moon nights respectively. The TUSSIM algorithms are described and the expected TUS statistics is presented for 5 years of data collection from the 500 km solar-synchronized orbit with allowance for the variability of the background light intensity during the space flight.

The proposed boring head may be removed from the machined hole without scratching the wall. To prevent scratching, the head diameter may be adjusted by as much as 0.4 mm. The maximum accuracy of the hole diameter corresponds to the eighth quality class. Such tools are used to produce holes of diameter 70–200 mm.

An adjustable reamer permitting scratch-free extraction from the machined hole is described. Formulas for the geometric parameters of reamers with diameters in the range 32–140 mm are presented. The results required for the development of design documentation are derived.

TUS (Tracking Ultraviolet Set-up) is the world's first orbital detector of ultra-high-energy cosmic rays (UHECRs). It was launched into orbit on 28th April 2016 as a part of the scientific payload of the Lomonosov satellite. The main aim of the mission was to test the technique of measuring the ultraviolet fluorescence and Cherenkov radiation of extensive air showers generated by primary cosmic rays with energies above ~100 EeV in the Earth atmosphere from space. During its operation for 1.5 years, TUS registered almost 80,000 events with a few of them satisfying conditions anticipated for extensive air showers (EASs) initiated by UHECRs. Here we discuss an event registered on 3rd October 2016. The event was measured in perfect observation conditions as an ultraviolet track in the nocturnal atmosphere of the Earth, with the kinematics and the light curve similar to those expected from an EAS. A reconstruction of parameters of a primary particle gave the zenith angle around 44$^\circ$ but an extreme energy not compatible with the cosmic ray energy spectrum obtained with ground-based experiments. We discuss in details all conditions of registering the event, explain the reconstruction procedure and its limitations and comment on possible sources of the signal, both of anthropogenic and astrophysical origin. We believe this detection represents a significant milestone in the space-based observation of UHECRs because it proves the capability of an orbital telescope to detect light signals with the apparent motion and light shape similar to what are expected from EASs. This is important for the on-going development of the future missions KLYPVE-EUSO and POEMMA, aimed for studying UHECRs from space., 24 pages; v2: important changes to address comments by the anonymous referee; main conclusions unchanged

The influence of misalignment of the reamer axis and the spindle axis on the precision of the machined hole is investigated by means of a special regression model of reaming. Recommendations are made for reduction in the error.

One of the fundamental concepts of the extension theory developed in the works of A. N. Dranishnikov and E. V. Shchepin is the concept of relation of extensiveness, which was introduced by K. Kuratowski. We describe the behavior of the relation of extensiveness with respect to certain types of subspaces of topological products and spaces, which are the Stone–Cech compactifications of the discrete sums of the Hilbert cube.

The TUS telescope, part of the scientific equipment on board the Lomonosov satellite, is the world’s first orbital detector of ultra-high energy cosmic rays. Preliminary results from analyzing unexpected powerful signals that have been detected from the first days of the telescope’s operation are presented. These signals appear simultaneously in time intervals of around 1 μs in groups of adjacent pixels of the photodetector and form linear track-like sequences. The results from computer simulations using the GEANT4 software and the observed strong latitudinal dependence of the distribution of the events favor the hypothesis that the observed signals result from protons with energies of several hundred MeV to several GeV passing through the photodetector of the TUS telescope.

A design procedure for adjustable reamers with a removable cutting plate is outlined, and some reamer designs are presented.

The paper discusses the optimization of a pulsed automatic control system (ACS) with constant parameters, which is used to control non-stationary objects. We obtained the dependences of the integral quality criterion on perturbations acting on the control object. The sensitivity of the ACS was studied by simulation using MATLAB / Simulink. The system was optimized based on the criterion constructed taking into account sensitivity to parameter variations. It is shown that the synthesis of the ACS insensitive to changes in characteristics is advisable only if the deviations of the parameters are small. In this case, the quality of automatic control will improve.

The task of analyzing the characteristics of the embryonic development of lower vertebrates using non-invasive optical methods is considered. We propose to apply hyperspectral imaging for segmentation of embryo zones with different physical and chemical properties. This approach allows one to obtain information on the spatial distribution of optical spectral properties of the observed object. An experimental setup based on a microscope coupled with a spectral imaging add-on module utilizing a tunable acousto-optic filter has been created to implement this approach. Hyperspectral data arrays are formed as a series of spectral narrowband images obtained by successive tuning of the acousto-optic filter within the working spectral range. A series of experiments was conducted in which the development of embryos of the Misgurnus fossilis loach during their transition from the 32nd to the 33rd developmental stage was observed using the described experimental setup. Characteristic spatial regions corresponding to certain parts of the loach embryo were identified. The time dependences characterizing the change in the spectral properties of the selected regions were obtained. It is shown that joint processing of a series of spectral images obtained in different spectral bands within the working spectral range of an acousto-optical spectral imaging module allows one to effectively identify differences in the kinetics of the optical transmission spectral density for various regions of the axial mesoderm.

The article presents the description of the changes in the concentrations of pro‐inflammatory cytokines and soluble forms of selectins and immunoglobulin superfamily adhesion molecules in patients with chronic generalized slight periodontitis. Serum concentrations of interleukin‐1‐β, tumor necrosis factor‐ α, soluble forms of P‐ and E‐selectins, intercellular adhesion molecule (ICAM‐1), vascular adhesion molecules (VCAM‐1) and platelet‐endothelial adhesion molecules (PECAM‐1) in healthy subjects and patients with slight periodontitis before and after treatment were assessed. It was found that the serum concentration of sICAM‐1, sVCAM‐1, sP‐, sE‐ selektins and pro‐inflammatory cytokines are increased in patients with chronic generalized periodontitis. The increase of serum concentration of soluble forms of selectins is expressed more significantly than sICAM‐1 and sVCAM‐1. There are no statistically significant changes of serum sPECAM‐1 in the examined group of patients in comparison with control. Complex therapy, including etiological and pathogenetic treatment, is completely normalized the concentration of pro‐inflammatory cytokines, and soluble forms of studied endothelial adhesion molecules in patients with chronic generalized slight periodontitis. All the studied parameters in patients with chronic generalized slight periodontitis after treatment are in the range of the control group variability.

We describe the relation between operators of invariant differentiation and invariant operators on orbits of Lie group actions. We propose a new effective method for finding differential invariants and operators of invariant differentiation and present examples.

The “Lomonosov” space project is lead by Lomonosov Moscow State University in collaboration with the following key partners: Joint Institute for Nuclear Research, Russia, University of California, Los Angeles (USA), University of Pueblo (Mexico), Sungkyunkwan University (Republic of Korea) and with Russian space industry organizations to study some of extreme phenomena in space related to astrophysics, astroparticle physics, space physics, and space biology. The primary goals of this experiment are to study: - Ultra-high energy cosmic rays (UHECR) in the energy range of the Greizen-Zatsepin-Kuzmin (GZK) cutoff; - Ultraviolet (UV) transient luminous events in the upper atmosphere; - Multi-wavelength study of gamma-ray bursts in visible, UV, gamma, and X-rays; - Energetic trapped and precipitated radiation (electrons and protons) at low-Earth orbit (LEO) in connection with global geomagnetic disturbances; - Multicomponent radiation doses along the orbit of spacecraft under different geomagnetic conditions and testing of space segments of optical observations of space-debris and other space objects; - Instrumental vestibular-sensor conflict of zero-gravity phenomena during space flight. This paper is directed towards the general description of both scientific goals of the project and scientific equipment on board the satellite. The following papers of this issue are devoted to detailed descriptions of scientific instruments.