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Wyniki wyszukiwania dla: VEHICLE ACOUSTICS
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Driving force of acoustic streaming caused by aperiodic sound beamin unbounded volumes
PublikacjaRównanie dynamiczne kierujące lokalnej w czasie siłą radiacyjną ruchu wirowego wyprowadzono. Stwierdzono, iż zawiera ona trzy części: jedna stanowi wzór klasyczny, druga daje zero po uśrednieniu względem okresu fali akustycznej, lecz różni się od zera dla nieokresowego dźwięku. Trzecia składowa związana jest z małymi dyfrakcyjnymi efektami, zachodzącymi podczas propagacji wiązki. Przejście do wzoru klasycznego w przypadku źródła...
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Te use of acoustic emission for assessment of the oil lubricity in a four-ball tester
Publikacjain view of the increased dynamic and temperature load in the compression-ignition engine tribological systems, particular attention is drawn to the problem of such lubrication of the friction nodes that after breaking the boundary layer it could be restored without any wear occurring. therefore, an idea has been devised of introducing to friction nodes, with the lubrication oils, of new substances (operational preparations) modifying...
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Automatic sound source localization in disturbing conditions using acoustic vector sensors
PublikacjaA concept, practical realization and applications of a passive acoustic radar to automatic localization and tracking of sound sources in disturbing conditions were presented in the paper. The device consists of the new kind of multichannel miniature sound intensity sensors and a group of digital signal processing algorithms. The sensitivity of the realized acoustic radar was examined in free sound field. Several kinds of sound...
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Vortex cavitation as a source of high level acoustic pressure generated by ship propellers
PublikacjaPraca przedstawia wyniki badań teoretycznych i eksperymentalnych nad mechanizmami fizycznymi generowania wysokiego ciśnienia akustycznego przez kawitujące wiry wierzchołkowe powstające na śrubach okrętowych
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Application of passive acoustic radar to automatic localization, tracking and classification of sound sources
PublikacjaA concept, practical realization and applications of the passive acoustic radar to automatic localization, tracking and classification of sound sources were presented in the paper. The device consists of a new kind of multichannel miniature sound intensity sensors and a group of digital signal processing algorithms. Contrary to active radars, it does not emit the scanning beam but after receiving surrounding sounds it provides...
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Standing Waves and Acoustic Heating (or Cooling) in Resonators Filled with Chemically Reacting Gas
PublikacjaStanding waves and acoustic heating in a one-dimensional resonator filled with chemically reacting gas, is the subject of investigation. The chemical reaction of A ! B type, which takes place in a gas, may be reversible or not. Governing equations for the sound and entropy mode which is generated in the field of sound are derived by use of a special mathematical method. Under some conditions, sound waves propagating in opposite...
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Underwater acoustic communication system using broadband signal with hyperbolically modulated frequency
PublikacjaThe implementation of reliable acoustic underwater communication in shallow waters is a scientific and engineering challenge, mainly due to the permanent occurrence of the multipath phenomenon. The article presents the concept of a transmission system using a broadband signal with hyperbolically modulated frequency (HFM) to transmit data symbols and synchronize data frames. The simulation tests were carried out in channels with...
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Adaptive Identification of Underwater Acoustic Channel with a Mix of Static and Time-Varying Parameters
PublikacjaWe consider the problem of identification of communication channels with a mix of static and time-varying parameters. Such scenarios are typical, among others, in underwater acoustics. In this paper, we further develop adaptive algorithms built on the local basis function (LBF) principle resulting in excellent performance when identifying time-varying systems. The main drawback of an LBF algorithm is its high complexity. The subsequently...
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Acoustic lifecycle study of the double-layer porous asphalt on E4 in Huskvarna, Sweden
PublikacjaIn 2010 a double-layer porous asphalt concrete (DPAC) pavement was constructed on the E4 motorway through the Swedish city Huskvarna. Earlier experience in Sweden indicated that it was feasible to obtain a high initial noise reduction but due to the widespread use of studded tires in winter, clogging and ravelling created losses of around 2 dB per year, with an expected acoustical lifetime of only 3 years. However, the improved...
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Decomposition of Acoustic and Entropy Modes in a Non-Isothermal Gas Affected by a Mass Force
PublikacjaDiagnostics and decomposition of atmospheric disturbances in a planar flow are considered in this work. The study examines a situation in which the stationary equilibrium temperature of a gas may depend on the vertical coordinate due to external forces. The relations connecting perturbations are analytically established. These perturbations specify acoustic and entropy modes in an arbitrary stratified gas affected by a constant...
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The influence of time of hearing aid use on auditory perception in various acoustic situations
PublikacjaThe assessment of sound perception in hearing aids, especially in the context of benefits that a prosthesis can bring, is a complex issue. The objective parameters of the hearing aids can easily be determined. These parameters, however, do not always have a direct and decisive influence on the subjective assessment of quality of the patient’s hearing while using a hearing aid. The paper presents the development of a method for...
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Extended duration running and impulse loading characteristics of an acoustic bearing with enhanced geometry
PublikacjaThis paper presents performance during prolonged running of the acoustic bearing when PZTs are switched off and when they are switched on. The effect of active PZT on shaft’s displacements in X and Y directions is clearly demonstrated. Performance of the acoustic bearing was also assessed when an impulse force was applied to the running shaft at speed. Once again the benefits of having PZTs active are beyond doubt. The instability...
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Comparison of Lithuanian and Polish Consonant Phonemes Based on Acoustic Analysis – Preliminary Results
PublikacjaThe goal of this research is to find a set of acoustic parameters that are related to differences between Polish and Lithuanian language consonants. In order to identify these differences, an acoustic analysis is performed, and the phoneme sounds are described as the vectors of acoustic parameters. Parameters known from the speech domain as well as those from the music information retrieval area are employed. These parameters are...
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Impact of Boundary Conditions on Acoustic Excitation of EntropyPerturbations in a Bounded Volume of Newtonian Gas
PublikacjaExcitation of the entropy mode in the field of intense sound, that is, acoustic heating, is theoreticallyconsidered in this work. The dynamic equation for an excess density which specifies the entropy mode,has been obtained by means of the method of projections. It takes the form of the diffusion equation withan acoustic driving force which is quadratically nonlinear in the leading order. The diffusion coefficient isproportional...
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STUDY OF SEASONAL ACOUSTIC PROPERTIES OF SEA WATER IN SELECTED WATERS OF THE SOUTHERN BALTIC
PublikacjaClimate Research of the globe is a current task, in particular to confirm the general hypothesis of global warming associated with an increase in average temperature. The sea acoustic climate is derived from the concept of climate and refers to the conditions of propagation of acoustic waves in a particular basin. In this paper, the results of systematic measurements of temperature, salinity and velocity distributions of sound...
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Multiple sound sources localization in real time using acoustic vector sensor
PublikacjaMethod and preliminary results of multiple sound sources localization in real time using the acoustic vector sensor were presented in this study. Direction of arrival (DOA) for considered source was determined based on sound intensity method supported by Fourier analysis. Obtained spectrum components for considered signal allowed to determine the DOA value for the particular frequency independently. The accuracy of the developed...
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Acoustic Emission Monitoring of Structural Elements of a Ship for Detection of Fatigue and Corrosion Damages
PublikacjaUszkodzenia korozyjne i pęknięcia zmęczeniowe są głównymi przyczynami defektów strukturalnych we wszystkich środkach transportu takich jak statki, cysterny drogowe i kolejowe. Oba typy degradacji tzn. degradacja materiału i konstrukcji są przedmiotem badań przeprowadzanych w projekcie badawczym VII Programu Ramowego Unii Europejskiej o nazwie ''Monitorowanie efektywnych kosztów korozji i zmęczenia w środkach transportu'' (akronim...
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development of an open source software to transform acoustic data for classification of benthic habitat
Publikacja.
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Experimental study of corrosion in reinforced concrete by acoustic emission and electrochemical noise techniques
PublikacjaTechnika emisji akustycznej jest znaną metodą badań korozji zbrojenia żelbetu. Źródłem aktywności akustycznej są zawsze zjawiska o naturze mechanicznej. Przedstawiono wynik badań akustycznych zbrojonego betonu w warunkach polaryzacji anodowej, przyspieszającej procesy korozyjne. Symultanicznie prowadzona była rejestracja szumu elektrochemicznego. Dla umożliwienia korelacji wyników, uzyskanych obiema technikami, wykonana została...
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Combining visual and acoustic modalities to ease speech recognition by hearing impaired people
PublikacjaArtykuł prezentuje system, którego celem działania jest ułatwienie procesu treningu poprawnej wymowy dla osób z poważnymi wadami słuchu. W analizie mowy wykorzystane zostały parametry akutyczne i wizualne. Do wyznaczenia parametrów wizualnych na podstawie kształtu i ruchu ust zostały wykorzystane modele Active Shape Models. Parametry akustyczne bazują na współczynnikach melcepstralnych. Do klasyfikacji wypowiadanych głosek została...
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System identification theory-based estimation of underwater acoustic channel for broadband communications.
PublikacjaPłytki kanał podwodny jest niestacjonarny z powodu wielokrotnych odbić fal dźwiękowych od powierzchni wody oraz ruchu nadajnika i odbiornika systemu komunikacyjnego. Dla zapewnienia szybkiej transmisji danych niezbędna jest estymacja kanału oparta na equalizacji adaptacyjnej. W systemach komunikacji podwodnej stosowane są zazwyczaj equalizery DFE z zaimplementowanymi algorytmami najmniejszych kwadratów: LMS oraz RLS.W artykule...
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Acoustic evaluation of road surfaces using different Close Proximity testing devices
PublikacjaAccording to the valid standard, Close Proximity (CPX) method intends to evaluate the influence of road surfaces on traffic noise. Measurements may be carried out with the use of a self-powered vehicle or a special test trailer equipped with testing tyre towed by another vehicle. Two different testing devices took part in the research organized in Poland in order to determine the ranking of road surfaces in terms of acoustic parameters....
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Gdansk 2020, Miszewskiego street - video data - pedestrian, bicycles, vehicles
Dane BadawczeGdansk 2020, Miszewskiego street - video data - pedestrian, bicycles, vehicles
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Gdansk 2020, Grunwaldzka (E) street - video data - pedestrian, bicycles, vehicles
Dane BadawczeGdansk 2020, Grunwaldzka (E) street - video data - pedestrian, bicycles, vehicles
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Gdansk 2020, Obroncow Wybrzeza - pedestrian crossing (E) street - video data - pedestrian, bicycles, vehicles
Dane BadawczeThe data contain video traffic data (pedestrian, cyclists, vehicles) registered at Obroncow Wybrzeza street. Date 12.08.2020, 6:00-20:00. The video camera was installed around pedestrian crossings. Camera was mounted on 7-meter-high mast.
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Gdansk 2020, Bema street - video data - pedestrian, bicycles, vehicles
Dane BadawczeThe data contain video traffic data (pedestrian, cyclists, vehicles) registered at Bema street (Bema – Kartuska crossing). Date 06.08.2020 6:00-22:00. The video camera was installed around bicycle crossings and pedestrian crossings at crossing. Camera was mounted on 7-meter-high mast.
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Vehicular Communication Environments
PublikacjaCommunication to and between road vehicles (cars, truck, buses, trains, etc.) are of growing interest. This is partly due to the attractive services that cooperative intelligent transport systems (C-ITSs) provides, mainly in the areas of traffic safety and traffic efficiency. An enabler for C-ITS is wireless vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication, collectively referred to as vehicle-to-X (V2X)...
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Camera Orientation-Independent Parking Events Detection
PublikacjaThe paper describes the method for detecting precise position and time of vehicles parking in a parking lot. This task is trivial in case of favorable camera orientation but gets much more complex when an angle between the camera viewing axis and the ground is small. The method utilizes background subtraction and object tracking algorithms for detecting moving objects in a video stream. Objects are classified into vehicles and...
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An assessment of regulated emissions and CO2 emissions from a European light-duty CNG-fueled vehicle in the context of Euro 6 emissions regulations
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Methodology for the Correction of the Spatial Orientation Angles of the Unmanned Aerial Vehicle Using Real Time GNSS, a Shoreline Image and an Electronic Navigational Chart
PublikacjaUndoubtedly, Low-Altitude Unmanned Aerial Vehicles (UAVs) are becoming more common in marine applications. Equipped with a Global Navigation Satellite System (GNSS) Real-Time Kinematic (RTK) receiver for highly accurate positioning, they perform camera and Light Detection and Ranging (LiDAR) measurements. Unfortunately, these measurements may still be subject to large errors-mainly due to the inaccuracy of measurement of the optical...
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Impact damage detection in smart composites using nonlinear acoustics—cointegration analysis for removal of undesired load effect
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Gdansk 2020, Krynicka (S) street - video data - pedestrian, bicycles, vehicles
Dane BadawczeThe data contain video traffic data (pedestrian, cyclists, vehicles) registered at Krynicka (S) street. Date 11.08.2020, 6:00-20:00. The video camera was installed around bicycle crossings and pedestrian crossings at Krynicka - Kolobrzeska crossing. Camera was mounted on 7-meter-high mast.
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Gdansk 2020, Strzelecka (N) street - video data - pedestrian, bicycles, vehicles
Dane BadawczeThe data contain video traffic data (pedestrian, cyclists, vehicles) registered at Strzelecka street. Date 06.08.2020, 6:00-20:00. The video camera was installed around bicycle crossings and pedestrian crossings at Strzelecka - Nowe Ogrodycrossing. Camera was mounted on 7-meter-high mast.
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Gdansk 2020, Obroncow Wybrzeza - crossing (E) street - video data - pedestrian, bicycles, vehicles
Dane BadawczeThe data contain video traffic data (pedestrian, cyclists, vehicles) registered at Obroncow Wybrzeza (E) street. Date 11.08.2020, 13:00-20:00. The video camera was installed around bicycle crossings and pedestrian crossings at Obroncow Wybrzeza – Chlopska crossing. Camera was mounted on 7-meter-high mast.
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Gdansk 2020, Czarny Dwor (N) street - video data - pedestrian, bicycles, vehicles
Dane BadawczeThe data contain video traffic data (pedestrian, cyclists, vehicles) registered at Czarny Dwor street. Date 13.08.2020, 6:00-20:00. The video camera was installed around bicycle crossings and pedestrian crossings at Czarny Dwor – Jana Pawla II. Camera was mounted on 7-meter-high mast.
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Gdansk 2020, Krynicka (N) street - video data - pedestrian, bicycles, vehicles
Dane BadawczeThe data contain video traffic data (pedestrian, cyclists, vehicles) registered at Krynicka (N) street. Date 11.08.2020, 6:00-20:00. The video camera was installed around bicycle crossings and pedestrian crossings at Krynicka - Kolobrzeska crossing. Camera was mounted on 7-meter-high mast.
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The Impact of Weather on Traffic Speed in Urban Area
PublikacjaThe issue of the impact of weather conditions on trip speed of vehicles has been studied for a long time and it is still the subject of many scientific researches. The impact of atmospheric conditions on the speed with which drivers drive their vehicles seems to be obvious. Good weather conditions, sunny weather with good visibility surely provokes higher speed while rainfall, wind...
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The estimation of fish lenght distribution from its acoustical measures
PublikacjaThe paper concerns the problem of estimating fish length PDF from its target strength PDF obtained from acoustic surveys. It has been shown that the target strength of single fish can be treated in the first approximation as a finction of two variables: one, which depends on fish size and the other, which depends on its angular orientation (aspect). Extending this simplified relationship to the case of fish populations allows to...
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Regulated Emissions, Unregulated Emissions and Fuel Consumption of Two Vehicles Tested on Various Petrol-Ethanol Blends
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Photogrammetric Development Of The Threshold Water At The Dam On The Vistula River In Wloclawek From Unmanned Aerial Vehicles (Uav)
PublikacjaBarrage in Wloclawek (Poland) was designed by Hydroprojekt and built in the years of 1962 - 1970 as the first stage of the planned Lower Vist ula Cascade. Cascade design assumed the construction of 8 dams in Wyszogr o d, Plock, Wloclawek, Nieszawa (Ciechocinek as an option), Solec Kujawski, Chelmno, Opalen and Tczew. Nieszawa dam was supposed to ensure the maintenance of an adequate free surface...
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Analysis of effect of overloaded vehicles on fatigue life of flexible pavements based on weigh in motion (WIM) data
PublikacjaOverloaded vehicles have a significant impact on pavement fatigue life and distress. As the studies show, the phenomena intensify when the control of traffic is poor. The paper presents the results of the research including analysis of weigh in motion data from eight stations and analysis of asphalt pavement fatigue caused by mixed traffic. Distributions of vehicles axles load including the multiple axles effects are presented....
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Determination of Vehicles Load Equivalency Factors for Polish Catalogue of Typical Flexible and Semi-rigid Pavement Structures
PublikacjaThe new Polish Catalog of Typical Flexible and Semi-rigid Pavement Structures was introduced to use in practice in 2014. Much of works were focused on actualization of vehicles load equivalency factors. For this purpose data delivered from weigh-inmotion were analyzed. Four methods of determination of load equivalency factors for pavement structure design were compared. The analysis showed that fourth power equation, AASHTO 1993...
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Examining Impact of Speed Recommendation Algorithm Operating in Autonomous Road Signs on Minimum Distance between Vehicles
PublikacjaAn approach to a new kind of recommendation system design that suggests safe speed on the road is presented. Real data obtained on roads were used for the simulations. As part of a project related to autonomous road sign development, a number of measurements were carried out on both local roads and expressways. A speed recommendation model was created based on gathered traffic data employing the traffic simulator. Depending on...
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Expert opinion on the effectiveness of protection against electric shock in case of fault in an installation for electric vehicles charging
PublikacjaThe opinion concerns the use of residual current devices for protection against electric shock by automatic disconnection of supply in a Norwegian installation intended for charging of electric vehicles.
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Road Tests of the Positioning Accuracy of INS/GNSS Systems Based on MEMS Technology for Navigating Railway Vehicles
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Gdansk 2020, 3 Maja street - video data - pedestrian, bicycles, vehicles
Dane BadawczeThe data contain video traffic data (pedestrian, cyclists, vehicles) registered at 3 Maja street (3 Maja - Al. Zwyciestwa - Blednik - Trakt Konny crossing). Date 06.08.2020 6:00-22:00. The video camera was installed around bicycle crossings and pedestrian crossings at crossing. Camera was mounted on 7-meter-high mast.
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Gdansk 2020, Bora Komorowskiego street - video data - pedestrian, bicycles, vehicles
Dane BadawczeThe data contain video traffic data (pedestrian, cyclists, vehicles) registered at Bora Komorowskiego street (Bora Komorowskiego - Chlopska - Obroncow Wybrzeza crossing). Date 06.08.2020 6:00-22:00. The video camera was installed around bicycle crossings and pedestrian crossings at crossing. Camera was mounted on 7-meter-high mast.
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Problem of proper decomposition and initialization of acoustic and entropy modes in a gas affected by the mass force
PublikacjaThe relations connecting perturbations specific for acoustic and entropy modes in an accelerated fluid or in a fluid affected by constant mass force, are derived. They allow to decompose the total vector of perturbations and the overall energy into acoustic and non-acoustic parts uniquely at any instant. In order to do this, three quantities are required, for example total perturbations in entropy, pressure and velocity. The evaluations...
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3D Sound Intensity Measurement Around Organ Pipes Using Acoustic Vector Sensors
PublikacjaThe aim of the presented paper was to obtain and visualize sound intensity distribution of radiated acoustic energy around the organ pipes. The experimental setup consisted of the multichannel acoustic vector sensor and the specialized Cartesian robot. Measurements were performed in free field with spatial resolution of 0.1 [m]. Two organ pipes, i.e. wooden and metal were measured during the ex-periment. The organ pipes were activated...
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Application of acoustic emission for detection of fatigue microdemage in main and crank bearings for diesel engines
PublikacjaThe article presents reasons for applying the acoustic emission (AE) to detect fatigue microdamage in main bearings and crank bearings of ship main engines. Problem of determination of the fatigue life for slide bearing bushes was characterized in general. There were demonstrated properties of the objects of research, which were bushings made of the MB58 alloy, as well as an overall description of the research. It was shown that...