wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: ABRASIVE WEAR RESISTANCE
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Decreasing CO2 Emissions By Reducing Tire Rolling Resistance
PublikacjaThe first motor vehicle was built by Nicolas Cugnot almost 250 years ago and since then there has been a continuous process of motor vehicles’ improvements, as well as development of new road pavements. The fuel crisis of the 70s of the 20th century made it clear to vehicle builders that measures should be taken to reduce vehicle fuel consumption and it contributed to an increased interest in electric vehicles. Although significant...
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Influence of Road Wetness on Tire-Pavement Rolling Resistance
PublikacjaRolling resistance of tires is one of the most important factors influencing energy consumption of road vehicles, especially on rural roads. For practical reasons, most of rolling resistance measurements are usually performed for dry road conditions. Based on the fact that roads are wet during a considerable time over the year and as part of the projects MIRIAM, ROLRES and ROSANNE, the TUG (Technical University of Gdańsk) in Poland...
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Influence of abrasive slurry dosage on flat surface lapping effects
PublikacjaPrzedstawiono wyniki badań dawkowania zawiesiny ściernej w obróbce powierzchni płaskich na docierarce jednotarczowej. Analizowano wpływ dawki ścierniwa na wydajność i jakość obróbki elementów ceramicznych i miedzianych.
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Study of abrasive slurry dosage in flat surfaces lapping process
PublikacjaPrzedstawiono wyniki badań dozowania pasty i zawiesiny ściernej w procesach docierania powierzchni płaskich. Badano wpływ wielkości dawki ścierniwa na podstawowe parametry chropowatości powierzchni elementów miedzianych i ceramicznych. Docierano miedź betlenową MOOB oraz ceramikę Al2O3 i Al2O3-ZrO2 mikroziarnami węglika krzemu i węglika boru.
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The Influence of Abrasive Machine on Temperature During One Side Lapping
PublikacjaPrzedstawiono wyniki badań temperatury układu wykonawczego docierarki jednotarczowej. Analizowano temperaturę trzech pierścieni prowadzących separatory przy wykorzystaniu kamery termograficznej V-20 II firmy VIGO System S.A.
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Analysis of size and shape of abrasive micrograins in lapping of assembly joints
PublikacjaPrzedstawiono skomputeryzowana analizę wielkości i kształtu mikroziaren ściernych. W badaniach mikroziaren węglika boru, węglika krzemu i elektrokorundu zastosowano mikroskopie optyczna oraz specjalistyczne oprogramowanie MultiScan v.6.08
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TEMPERATURE INFLUENCE ON TIRE ROLLING RESISTANCE MEASUREMENTS QUALITY
PublikacjaGlobal warming makes it necessary to reduce energy consumption, which in the case of motor vehicles, is connected, among other things, with reduction of resistive forces acting on a vehicle during its motion. One of the most important components of those forces is rolling resistance, which is very difficult to measure, especially in road conditions. The article deals with issues related to the influence of the thermal state of...
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Algorithm for Automatic Wear Estimation of Railway Contact Strips Based on 3D Scanning Results
PublikacjaElectric rail vehicles use current collection system which consists of overhead contact line and a current collector (pantograph) mounted on the roof of a vehicle. A pantograph is equipped with contact strips, which slide along the contact wire, ensuring steady electric contact. Contact strips are made of carbon layer, fixed to an aluminum carrier. The carbon layer wears down due to friction. Using overly worn contact strips increases...
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Tribo-Environment Dependent Chemical Modification of Sliding Interfaces in Ultrananocrystalline Diamond Nanowall Film: A Correlation with Friction and Wear
PublikacjaTribological properties of ultrananocrystalline diamond nanowall (UNCD NW) films were investigated quantitatively in three different and controlled tribo-environmental conditions, proposing the passivation and graphitization mechanisms. However, these mechanisms are rather complicated and possibly can be understood in well-controlled tribological conditions. It was shown that the friction and wear of these films were high in highPage 1...
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Elctrochemical oxidation and corrosion resistance of the Ti13Nb13Zr alloy
PublikacjaThis paper presents the results of oxidation and corrosion tests carried out on titanium alloy Ti13Nb13Zr. The oxide film was prepared by electrochemical environment 2M H3PO4 for 30 min and 1 h, at a constant voltage 40V. The tests of corrosion resistance were performed by potentiostatic method in Ringer's solution at different pH values: 7, 5 and 3. The change in an appearance of surface and the increase in corrosion resistance...
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Analysis of Rolling Resistance of Tires With Run Flat Insert
PublikacjaRun flat properties are required for tires intended for special applications like military or rescue vehicles. Run-Flat inserts make possible to drive a car or truck, with certain restrictions, also when inflation pressure is very low or non-existing (after tire damage). Rolling resistance of tires rolling the inserts increases considerably in relation to the rolling resistance of properly inflated tires. This paper presents results...
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Scuffing and rolling contact fatigue resistance of discrete laser spot hardened austempered ductile iron
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Modernization of the Trailer for Tyre/Road Rolling Resistance Measurements
PublikacjaIn the article the ways of defining tyre rolling resistance are presented. The advantages of the laboratory tests of tyre/road rolling resistance and the advantages and disadvantages of on the road tyre/road rolling resistance tests are described. The description of the special trailer used for tyre/road rolling resistance measurements designed and constructed in the Faculty of Mechanical Engineering at Gdansk University of Technology,...
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A CONCEPT OF DETERMINING THE RELATION BETWEEN LOAD AND WEAR OF TRIBOLOGICAL SYSTEMS OF SHIP MAIN SELF-IGNITION ENGINES BY USING PROBABILISTIC APPROACH PROBABILISTIC APPROACH
PublikacjaThis paper presents a proposal of simultaneous consideration of load and wear associated with it , of tribological systems of ship main engines (intended for ship propulsion) . Based on results of investigations it was assumed that both the load Q (i.e. a cause of wear ) and the wear Z (i.e. an effect of load occurrence) considered in a given time t(0 ≤ t ≤ t) are random variables Qt and Zt, respectively. There was characterized...
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Comparison of Tire Rolling Resistance Measuring Methods for Different Surfaces
PublikacjaThe rolling resistance of car tires is one of the most important parameters characterizing tires today. This resistance has a very significant contribution to the energy consumption of wheeled vehicles. The climate crisis has forced tire and car manufacturers to place great emphasis on the environmental impact of their products. Paradoxically, the development of electric vehicles has led to an even greater importance of rolling...
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Hyperbolic heat conduction at a microscopic sliding contact with account of adhesion-deformational heat generation and wear
PublikacjaDifferent non-Fourier models were proposed to simulate temperatures in materials subjected to extremely fast thermal disturbances, when the speed of heat propagation should be concerned. The present study investigated temperature and heat balance at a microscopic sliding contact during a single frictional interaction based on the Cattaneo-Vernotte hyperbolic heat conduction equation. Two fundamental features of friction, namely,...
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Wear estimation of current collector contact strips by analysis of a 3D scanning results
PublikacjaThe technical condition of current collector contact strips is very important when operational reliability of railway transportation is considered. The authors proposed a novel measurement system based on a 3D camera to register the shape and dimensions of the current collector contact strips surface. The system was installed above the railway track for tests in target ambient. During the trial operation a few dozen of contact...
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Cavitation Erosion Resistance Influence of Material Properties
PublikacjaThe cavitation erosion is the phenomena that causes degradation of fluid flow machinery components due to repetitive implosion of cavitation bubbles adjacent to the solid surface. Cavitation erosion is a complex phenomenon, which includes not only hydrodynamic factors of liquid, but also properties of erodible material e.g. microstructure, hardness or Young modulus. In order to reduce the negative impact of erosion on machine components,...
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Shear resistance of low height precast concrete lintels
PublikacjaThe scope of the paper is to investigate analytically and determine experimentally the shear resistance of low height reinforced precast concrete lintels. The chosen procedures included in national and international standards applied for the design of structural concrete elements to an estimation of shear behaviour of reinforced concrete elements are described. The characteristic and designed shear strength of precast concrete...
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Antimicrobial resistance of fecal indicators in disinfected wastewater
PublikacjaThe main objective of the study was to assess the potential of three systems (UV irradiation, ozonation, and micro/ultrafiltration) operated in a pilot scale in removal of antimicrobial-resistant fecal bacteria from secondary effluent of the local wastewater treatment plant (700,000 population equivalent). The effectiveness of the processes was analysed using the removal ratio of fecal indicators (Escherichia coli and Enterococcus...
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Influence of bush wear in water lubricated marine stern tube bearings with shaft misalignment
PublikacjaWater lubricated propeller shaft bearings are frequently employed on modern ships due to their advantages such as durability, simplicity and low price. Specific working conditions on ships cause shaft misalignment which often results in rapid wearing of bush and shaft. Shaft misalignment could be an effect of manufacturing or assembly faults but sometimes it appears due to hull or shaft deformation. The wearing process has influence...
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Selected Aspects of Pavement Texture Influence on Tire Rolling Resistance
PublikacjaTire rolling resistance has a significant influence on fuel consumption in cars and trucks and on CO2 emissions. Rolling resistance depends on the tire construction, pavement texture and stiffness, as well as environmental and traffic conditions. This article presents a pilot study on the impact of pavement texture on the rolling resistance of passenger car tires. Reasons why Mean Profile Depth is not a good descriptor of pavement...
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Antimicrobial Resistance and Infection Control
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Fecal indicators resistance to antimicrobial agents present in municipal wastewater
PublikacjaIn this study removal rate of six antimicrobial compounds (belonging to folate pathway inhibitors and macrolides class) was analyzed in processes of local wastewater treatment plant (WWTP) together with susceptibility patterns of erythromycin (E) resistant Enterococcus spp. and trimethoprim/sulfamethoxazole (SXT) resistant Escherichia coli. According to the obtained data, six of tested antimicrobial agents, namely erythromycin,...
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Wear of Farm Buildings in Selected Farms
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Ship model resistance - KCS
Dane BadawczeShip model instantaneous resistance, velocity, pitch and heave measured data for a KCS built and tested in the towing tank of the Faculty of Mechanical Engineering and Ship Technology of Gdansk University of Technology under regular head waves.
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Porosity and shape of airborne wear microparticles generated by sliding contact between a low-metallic friction material and a cast iron
PublikacjaThe wear of brakes in transport vehicles is one of the main anthropogenic sources of airborne particulate matter in urban environments. The present study deals with the characterisation of airborne wear microparticles from a low-metallic friction material / cast iron pair used in car brakes. Particles were generated by a pin-on-disc machine in a sealed chamber at sliding velocity of 1.3 m/s and contact pressure of 1.5 MPa. They...
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Surface roughness of ceramic parts after lapping by abrasive-metallic tools
PublikacjaPrzedstawiono konstrukcję narzędzi ścierno-metalowych do obróbki na docierarce jednotarczowej. Wykonano badania docierania elementów z ceramiki tlenowej. Analizowano podstawowe parametry chropowatości powierzchni elementów z Al2O3 po obróbce narzędziami na bazie węglika boru.
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Abrasive property evaluation during microgrinding with single-disk lapping kinematics
PublikacjaPrzedstawiono wyniki badań mikroszliwowania z kinematyką docierania jednotarczowego. Analizowano narzędzie pod kątem trwałości. Wyznaczono zmieniające się właściwości ścierne narzędzia z wykorzystaniem systemu do automatycznej analizy obrazu.
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Detection of sulfonamide resistance genes via in situ PCR-FISH
PublikacjaDue to the rising use of antibiotics and as a consequence of their concentration in the environment an increasing number of antibiotic resistant bacteria is observed. The phenomenon has a hazardous impact on human and animal life. Sulfamethoxazole is one of the sulfonamides commonly detected in surface waters and soil. The aim of the study was to detect sulfamethoxazole resistance genes in activated sludge biocenosis by use of...
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The Effect of Full-Cell Impregnation of Pine Wood (Pinus sylvestris L.) on Changes in Electrical Resistance and on the Accuracy of Moisture Content Measurement Using Resistance Meters
PublikacjaThe impact of the full-cell impregnation of pine wood was investigated with respect to changes in electrical resistance and the accuracy of moisture content measurement. This study compared the resistance of impregnated and untreated pine timber harvested from the northern part of Poland (Pomeranian region). The wood was impregnated by the vacuum-pressure method. The preservative (TANALITH E 3475) and coloring (TANATONE 3950) agents...
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Impact of the surface evenness and texture on tire/road rolling resistance
PublikacjaThis paper deals with the issue of a surface's roughness and texture impact on tire/road rolling resistance. It includes a brief description of research aims, measurements and an analysis of results. It also presents observations and conclusions regarding drum facility modernisation which allows studies concerning surface's roughness and texture impact on tire/road rolling resistance.
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Antimicrobial resistance of fecal indicators in muncipal wastewater treatment plant
PublikacjaAntimicrobial resistance of fecal coliforms (n = 153) and enterococci (n = 199) isolates was investigated in municipal wastewater treatment plant (WWTP) based on activated sludge system. The number of fecal indicators (in influent and effluent as well as in the aeration chamber and in return activated sludge mixture) was determined using selective media. Susceptibility of selected strains was tested against 19 (aminoglycosides,...
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Atomic force microscopy images of copper electrical contacts wear under the influence of friction
Dane BadawczeMeasurement of wear of copper electrical contacts under the influence of friction. Imaging in contact mode in the variant of scanning spreading resistance microscopy. Additionally, there are spectroscopic current-voltage curves showing local changes in electrical conductivity. NTEGRA Prima (NT-MDT) device. Probe NSG 01Pt.
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THE ANALYSIS OF THE INFLUENCE OF STRESS DISTRIBUTION ON WEAR PROFILE IN LUBRICATED SLIDING CONTACT OF UHMW-PE VS TITANIUM Ti-13Nb-13Zr ALLOY
PublikacjaMetal – polymer sliding contacts are a typical combination in industry and medicine. For decades such a set of materials has been the primary choice in human joints endoprosthetic technology. In this paper tribological issues of are presented from a research on the potential for practical use of Ti-13Nb-13Zr/UHMW-PE couple for orthopedic endoprosthesis. In tests on simplified models it is critically important to carefully...
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DESIGN AND CALIBRATION OF ROLLING RESISTANCE TEST TRAILER R2mk.2
PublikacjaThe paper describes construction nad calibration procedures of the rolling resistance test trailer R2 Mk2. The trailer is design to measure rolling resistance of passenger car tyres in various road conditions on trafficked road. The trailer utilizes so called angle method also known as vertical arm method. The paper presents also calibration procedures that are necessary to ascertain good precision of the measurements.
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The impact of material degradation on the resistance and reliability of truss structures
PublikacjaThe paper analyses limit load-carrying capacity and buckling load of truss towers used to support high voltage power lines. The analysed typical structure was subjected to characteristic loads and their combinations. The results were applied to assess structural resistance with regard to steel corrosion in the long-term operation. The extent of structural deterioration was assessed due to Young's modulus decrement in the course...
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High temperature corrosion resistance of porous hastelloy alloy
PublikacjaTo further understand the suitability of Ni-Cr-base alloy for solid oxide fuel cell (SOFC), a commercial Ni-Cr-Fe-Mo alloy, Hastelloy X was selected and evaluated for oxidation behaviour under high temperature conditions. HastelloyX was chosen due to its unusual resistance to oxidizing, reducing and neutral atmospheres. For long term stability of metal supported fuel cell, the corrosion resistance plays a vital role and must be...
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Review of Selected Methods for Prediction of Added Resistance in Following Waves
PublikacjaThe added resistance in waves is a mean value of non-linear, second order reaction of a ship to incoming waves. In the beginning of the 20th century, the experimental methods for investigation of ship hydrodynamics at model scale were developed. They allowed the evaluation of added resistance by measurements in irregular waves (directly) or by measurements in regular waves (in-direct method). The main goal was to find more precise...
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Verification of the criteria for evaluation of water and frost resistance of asphalt concrete
PublikacjaThe paper presents the results of field investigation - condition survey of existing pavements and the results of laboratory tests on water and frost resistance of samples cored from the these pavements. The purpose of testing was to verify the criteria for evaluation of the resistance of asphalt concrete to the action of water and frost by way of comparing the results of field and laboratory tests, followed by evaluation of their...
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A Study on Emission of Airborne Wear Particles from Car Brake Friction Pairs
PublikacjaThe emission of airborne wear particles from friction material / cast iron pairs used in car brakes was investigated, paying special attention to the influence of temperature. Five low-metallic materials and one non-asbestos organic material were tested using a pin-on-disc machine. The machine was placed in a sealed chamber to allow airborne particle collection. The concentration and size distribution of 0.0056 to 10 μm particles...
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Reduction of Tire Rolling Resistance by Optimization of Road Surfaces and Tires
PublikacjaDuring interaction between tire and road surface three very important phenomena are always in effect. One of them (very desirable) is friction that is important for traction, braking and cornering. Two other phenomena are not desirable at all, that is rolling resistance and noise. This paper discusses relations between road surface and tire parameters versus tire rolling resistance. Road surface texture, porosity, impedance, strength...
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Identification and antimicrobial resistance of Enterococcus spp. isolated from surface water
PublikacjaIn the study species distributions and antimicrobial resistance profiles were determined among riverine Enterococcus spp. Susceptibility of the isolates was tested against: ampicillin, imipenem, teicoplanin, vancomycin, erythromycin, linezolid, fosfomycin, ciprofloxacin,levofloxacin, moxifloxacin, tetracycline, high levels of gentamicin and streptomycin. The enterococci were detected in all of the analyzed water samples, periodically...
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Resistance is futile
PublikacjaOmówiono zasadę działania przyczepy dynamometrycznej służącej do pomiaru oporu toczenia opon do samochodów osobowych i dostawczych w warunkach drogowych. Przyczepa ta została zbudowana w Katedrze Pojazdów i Maszyn Roboczych Politechniki Gdańskiej. Zaprezentowano wyniki dadań oporu toczenia dwóch opon na nawierzchni SMA 0/12,8.
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Multi-objective optimization of tool wear, surface roughness, and material removal rate in finishing honing processes using adaptive neural fuzzy inference systems
PublikacjaHoning processes are usually employed to manufacture combustion engine cylinders and hydraulic cylinders. A crosshatch pattern is obtained that favors the oil flow. In this paper, Adaptive Neural Fuzzy Inference System (ANFIS) models were obtained for tool wear, average roughness Ra, cylindricity and material removal rate in finish honing processes. In addition, multi-objective optimization with the desirability function method...
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Features of load and wear of main propulsion devices on sea-going ships with piston combustion engines and their impact on changes in technical states of the systems
PublikacjaThe paper presents the specificity of operation of propulsion systems of seagoing ships which causes the need to control the load on them, especially on their engines called main engines. The characteristics of the load on the propulsion systems, especially on the main engines as well as on the shaft lines and propellers driven by the engines, along with the process of wear in tribological joints (sliding tribological systems)...
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Tests for lapping of flat surfaces of ceramic elements with forced dosing of abrasive slurry
PublikacjaPrzedstawiono zagadnienia dotyczące systemu wymuszonego dawkowania zawiesiny ściernej w docieraniu jednotarczowym powierzchni płaskich. Opisano zalety takiego systemu dozowania płynnej zawiesiny ściernej. Omówiono wybrane wyniki badań docierania elementów z ceramiki technicznej. Analizowano wpływ podstawowych warunków dawkowania zawiesiny na ubytek liniowy próbek.
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Reduction of noise and rolling resistance by horizontal grinding of asphalt pavements
PublikacjaGrinding of cement concrete pavements to reduce unevenness and noise is common since a long time. Grinding is then made with wheels equipped with diamond blades rotating in the vertical plane. This creates narrow vertical/longitudinal grooves in the pavement. It is not applied to asphalt pavements. In this paper an alternative type of grinding is studied. In this case plates with diamond heads rotate in the same plane as the pavement,...
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Grease effect on fretting wear of mild steel
PublikacjaNa stanowisku laboratoryjnym przeprowadzono badania zużycia frettingowego miękkiej stali smarowanej mineralnymi i syntetycznymi smarami zawierającymi także różne dodatki: grafit dwusiarczek molibdenu ZDDP i ditiocarbamat molibdenu, w różnych stężeniach.Badania wykazały istotny wpływ konsystencji smaru i jego właściwości smarnych na zużycie frettingowe miękkiej stali oraz zróżnicowany wpływ testowanych dodatków. Obecność smaru...
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The influence of contact geometry on friction and wear characteristics
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