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Search results for: SHAPE MEMORY ALLOY
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Quality increase for single-welded joints of thin-walled structures by means of simulation modelling
PublicationThe Simulation calculation module and the SolidWorks software package have helped to define the optimal shape and dimensions of single-welded joints which may serve the basis for calculating the process parameters of welding. Having compared the models with different weld cross-sections the authors have defined that the weld height and width do not significantly affect the stress concentration, and the stress concentration and...
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Tuning a Hybrid GPU-CPU V-Cycle Multilevel Preconditioner for Solving Large Real and Complex Systems of FEM Equations
PublicationThis letter presents techniques for tuning an accelerated preconditioned conjugate gradient solver with a multilevel preconditioner. The solver is optimized for a fast solution of sparse systems of equations arising in computational electromagnetics in a finite element method using higher-order elements. The goal of the tuning is to increase the throughput while at the same time reducing the memory requirements in order to allow...
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Efficient parallel implementation of crowd simulation using a hybrid CPU+GPU high performance computing system
PublicationIn the paper we present a modern efficient parallel OpenMP+CUDA implementation of crowd simulation for hybrid CPU+GPU systems and demonstrate its higher performance over CPU-only and GPU-only implementations for several problem sizes including 10 000, 50 000, 100 000, 500 000 and 1 000 000 agents. We show how performance varies for various tile sizes and what CPU–GPU load balancing settings shall be preferred for various domain...
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System of wireless magnetic sensors for detection and identification of ferromagnetic vehicles
PublicationThe paper presents the results of deformation of the Earth's magnetic field by land vehicles. Basing on the analysis of the shape of the magnetic field deformation, it is possible to detect and identify a vehicle. In order to eliminate the interference of the Earth's magnetic field by the environment, the measurements were performed in a differential configuration. Under a development project a wireless system of magnetic sensors...
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Biocompatibility and bioactivity of load-bearing metallic implants
PublicationThe main objective of here presented research is to develop the titanium (Ti) alloy base composite materials possessing better biocompatibility, longer lifetime and bioactivity behaviour for load-bearing implants, e.g. hip joint and knee joint endoprosthesis. The development of such materials is performed through: modeling the material behaviour in biological environment in long time and developing of new procedures for such evaluation;...
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The Cultures of Knowledge Organizations: Knowledge, Learning, Collaboration (KLC)
PublicationThis book focuses on seeing, understanding, and learning to shape an organization’s essential cultures. The book is grounded on a fundamental assumption that every organization has a de facto culture. These “de facto cultures” appear at first glance to be serendipitous, vague, invisible, and unmanaged. An invisible and unrecognized de facto culture can undermine business goals and strategies and lead to business failures. The authors...
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ОТТОКАР УЛЬ. IN MEMORIAM
PublicationОттокар Уль считается одним из самых влиятельных архитекторов Австрии второй половины ХХ века. Он внес значительный вклад в развитие партисипативных методов проектирования и пост-соборной реформы сакральной архитектуры. Статья освещает его биографию, идеи и проекты, а также и публикации. Кажется, что стоит, чтобы данный архитектор присутствовал в нашей памяти.
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LCF behavior of 2024AA under uni- and biaxial loading taking into account creep pre-deformation
PublicationThis study presents the results of experimental low-cycle fatigue (LCF) tests of aluminum 2024 alloy T3511 temper in uni- and biaxial loading states. Tests were carried out on both the as-received material (hardened extruded rods) and material with different pre-deformation histories. These deformations were carried out in the creep process at 200 °C and 300 °C for two different levels of at each temperature. The pre-deformed material’s...
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Materials Design for the Titanium Scaffold Based Implant
PublicationThe main objective of here presented research is a design the scaffold/porous titanium(Ti) alloy based composite material demonstrating better biocompatibility, longer lifetime andbioactivity behaviour for load-bearing implants. The development of such material is proposed bymaking a number of consecutive tasks. Modelling the mechanical, biomechanical and biologicalbehavior of porous titanium structure and an elaboration of results...
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Materials Design for the Titanium Scaffold Based Implant
PublicationThe main objective of here presented research is a design the scaffold/porous titanium(Ti) alloy based composite material demonstrating better biocompatibility, longer lifetime andbioactivity behaviour for load-bearing implants. The development of such material is proposed bymaking a number of consecutive tasks. Modelling the mechanical, biomechanical and biologicalbehavior of porous titanium structure and an elaboration of results...
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The Weibull model of the multipath fading channel
Open Research DataThe dataset contains the results of simulations that are part of the research on modelling the multipath fading in the communication channel. The Weibull fading envelope is generated using the Monte-Carlo simulation (MCS) in the LabVIEW programming environment.
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Identification of nonstationary processes using noncausal bidirectional lattice filtering
PublicationThe problem of off-line identification of a nonstationary autoregressive process with a time-varying order and a time-varying degree of nonstationarity is considered and solved using the parallel estimation approach. The proposed parallel estimation scheme is made up of several bidirectional (noncausal) exponentially weighted lattice algorithms with different estimation memory and order settings. It is shown that optimization of...
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Effects of the preheating laser treatment on microstructure and corrosion resistance of Ti6Al4V bioalloy
PublicationThe laser remelting of the Ti6Al4V alloy was made on specimens pre-heated at elevated temperatures. The laser treatment effected in change of microstructures of surface layers and an appearance of blisters and numerous cracks. The corrosion tests demonstrated the decrease in corrosion resistance for each preheating temperature. The observed effects were attributed to negative influence of excessive compressive stresses with no...
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Original footbridge in Mikolajki, Poland
PublicationIn summer 2016, a new footbridge in the town of Mikołajki (Poland) was built, over a stream connecting two adjacent lakes – Talty and Mikołajki. Its modern construction, based on the shape of a DN ice-boat, makes it inique in Poland, and probably in the world as well. This novel and dynamic shape became a significant landmark associated not only with Mikołajki, but also with the whole region of Mazury, as well as with sailing...
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Ethylene decomposition on TiO2 - UV and Fluorescence lamp
Open Research DataData contain chromatograms recorded during decomposition of ethylene flowing over TiO2 through the quartz tubular shape reactor. TiO2 was coated onto glass plates with dimension of 2cmx2cm, in total 3 plates were used and placed inside reactor. Reactor was irradiated by UV (Special 'TL'E, Philips) or fluorescent (Lumilux, OSRAM) 3 ring-shaped lamps,...
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A Task-Scheduling Approach for Efficient Sparse Symmetric Matrix-Vector Multiplication on a GPU
PublicationIn this paper, a task-scheduling approach to efficiently calculating sparse symmetric matrix-vector products and designed to run on Graphics Processing Units (GPUs) is presented. The main premise is that, for many sparse symmetric matrices occurring in common applications, it is possible to obtain significant reductions in memory usage and improvements in performance when the matrix is prepared in certain ways prior to computation....
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Zastosowanie programowania parametrycznego w planowaniu operacji obróbki elementów o powtarzalnej geometrii
PublicationPorównywano zastosowania dostępnych technik programowania obróbki numerycznej przedmiotów o powtarzających się elementach konstrukcji. Analizowano możliwości stosowania programowania parametrycznego w trybie programowania zorientowanego warsztatowo oraz pracy w środowisku systemu klasy CAM. Zwrócono uwagę na przejrzystość tworzonego programu w aspekcie możliwości jego edycji i korekty składni, formy zapisu programu w pamięci obrabiarki...
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Tripping limitations of residual current devices in photovoltaic installations
PublicationIn electrical installations with photovoltaic sources of energy, earth fault current may comprise alternating current component and direct current component. The waveform shape of this earth fault current mainly depends on the point of the fault and the properties of a photovoltaic power electronics converter. The waveform shape of the current influences operation of protection devices, especially tripping threshold of residual...
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Search for the most useful geometry of an acoustic journal bearing
PublicationComputer simulations of a number of journal bearing’s geometries utilising acoustic levitation were carried out. The choice of the best geometry depended on the ability of a deformed shape, created by piezo-electric elements, to facilitate squeeze film ultrasonic levitation, and also to create three evenly distributed diverging aerodynamic gaps. Deformations of analysed variants of the bearing’s shape were generated by numerical...
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Circularly Polarized Metalens Antenna Design for 5G NR Sub-6 GHz Communication Systems
Publication5G NR (new radio) FR1 range refers to as Sub-6GHz band (410MHz to 7125MHz and 3.4GHz to 6GHz). In this paper, the frequency range of interest is from 3.4 to 6GHz, as many cellular companies are focusing on this Sub-6GHz band. A wideband circularly polarized (CP) antenna radiator is designed with diamond shape patches, fed by a microstrip line at the bottom through a rectangular shape wide slot on a ground plane. The proposed CP...
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Computer vision techniques applied for reconstruction of seafloor 3D images from side scan and synthetic aperture sonars data
PublicationThe Side Scan Sonar and Synthetic Aperture Sonar are well known echo signal processing technologies that produce 2D images of the seafloor. Both systems combines a number of acoustic pings to form a high resolution image of seafloor. It was shown in numerous papers that 2D images acquired by such systems can be transformed into 3D models of seafloor surface by algorithmic approach using intensity information, contained in a grayscaled...
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Hydrogen Embrittlement and Oxide Layer E ect in the Cathodically Charged Zircaloy-2
PublicationThe present paper is aimed at determining the less investigated effects of hydrogen uptake on the microstructure and the mechanical behavior of the oxidized Zircaloy-2 alloy. The specimens were oxidized and charged with hydrogen. The different oxidation temperatures and cathodic current densities were applied. The scanning electron microscopy, X-ray electron diffraction spectroscopy, hydrogen absorption assessment, tensile, and...
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Multi-level Virtualization and Its Impact on System Performance in Cloud Computing
PublicationThe results of benchmarking tests of multi-level virtualized environments are presented. There is analysed the performance impact of hardware virtualization, container-type isolation and programming level abstraction. The comparison is made on the basis of a proposed score metric that allows you to compare different aspects of performance. There is general performance (CPU and memory), networking, disk operations and application-like...
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Numerical and Analytical Investigation of Aluminium Bracket Strengthening
PublicationThis paper focuses on an analytical and numerical investigation of aluminium brackets used to fasten light-weight curtain walls to building facilities. The authors propose a solution to increase the load capacity of aluminium brackets by means of additional cover plates (straps). This paper also includes a short survey of literature and material properties concerning the EN AW-6060 T6 aluminium alloy. This paper suggests an initiation...
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Nanocrystalline doped zirconia and ceria films for fuel cell application
PublicationW artykule przestawiono porównanie właścowości warstw nanokrystalicznych przygotowanych w technologii 'net-shape'. Materiały te mają zastosowanie w tlenkowychogniwach paliwowych.
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How Can We Identify Electrophysiological iEEG Activities Associated with Cognitive Functions?
PublicationElectrophysiological activities of the brain are engaged in its various functions and give rise to a wide spectrum of low and high frequency oscillations in the intracranial EEG (iEEG) signals, commonly known as the brain waves. The iEEG spectral activities are distributed across networks of cortical and subcortical areas arranged into hierarchical processing streams. It remains a major challenge to identify these activities in...
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Coherent-wave Monte Carlo method for simulating light propagation in tissue
PublicationSimulating propagation and scattering of coherent light in turbid media, such as biological tissues, is a complex problem. Numerical methods for solving Helmholtz or wave equation (e.g. finite-difference or finite-element methods) require large amount of computer memory and long computation time. This makes them impractical for simulating laser beam propagation into deep layers of tissue. Other group of methods, based on radiative...
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Towards an efficient multi-stage Riemann solver for nuclear physics simulations
PublicationRelativistic numerical hydrodynamics is an important tool in high energy nuclear science. However, such simulations are extremely demanding in terms of computing power. This paper focuses on improving the speed of solving the Riemann problem with the MUSTA-FORCE algorithm by employing the CUDA parallel programming model. We also propose a new approach to 3D finite difference algorithms, which employ a GPU that uses surface memory....
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SEM micrographs of aluminium corrosion in alkaline media with various bee products as corrosion inhibitors
Open Research DataThis dataset contains various scanning electron microscopy (SEM) micrographs of AA5754 aluminum alloy samples exposed to the corrosive alkaline environment without and with the addition of various bee products to act as green corrosion inhibitors. The products are bee pollen, honey, and putty. They were investigated in bicarbonate buffer (pH =10 or...
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Wavelet filtering of signals without using model functions
PublicationThe effective wavelet filtering of real signals is impossible without determining their shape. The shape of a real signal is related to its wavelet spectrum. For shape analysis, a continuous color wavelet spectrogram of signal level is often used. The disadvantage of continuous wavelet spectrogram is the complexity of analyzing a blurry color image. A real signal with additive noise strongly distorts the spectrogram based on continuous...
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Layered Morphology of Gdansk: Past, Present and Future.
PublicationThis study aims to analyze the urban fabric and form of the city of Gdańsk based on the Muratorian and Italian school of urban morphology, to deepen the understanding of the morphological process of the urban fabric. It can be seen that the urban fabric of the city is a juxtaposition of all these layers, and based on Muratori’s approach these are indicative of not just the past, present but also the future. The study sample is...
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Trends shaping innovations in the aerosol market
PublicationNew hygiene regimes and sustainability commitments are helping to shape the aerosol market. Norbert Piotrowski of Aerosol Service Poland explains the thinking behind the company’s latest hygiene innovations.
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Piotr Jabłoński
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The system for remote monitoring of a vertical axis wind farm
PublicationThe article presents a system for remote monitoring of working parameters of a wind turbine with a vertical axis. The monitoring system was built using a Raspberry PI 3 microcomputer with the Raspbian operating system and a MicroDAQ E2000 measuring card. The developed system enables monitoring the power output of the generator, torque on the turbine shaft, turbine speed and wind speed. The values of the monitored parameters are...
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Towards hardware built-in support for computer system safety
PublicationArtykuł omawia dostępne technologie wirtualizacji zasobów pamięci i systemów I/O w systemach komputerowych takie jak Execute Disable Bit (EDB) capability i Virtual Machine Architecture (VMA). Nastepnie wprowadza założenia na rozszerzenie tych technologii w celu uzyskania funkcjonalności Safe Call Execution dzieki technologii Execution Disabling Policies (EDP). Wprowadzono również założenia na funkcjonalność Memory Virtualization...
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Nanocomposite nickel ceria cermet with low nickel content for anode-supported SOFCs
PublicationW pracy przedstawiono badania nanokompozytowego cermetu z zawartościa niklu 7.5, 11, 14% niklu w cermecie. Cermet przygotowno z wykorzystanim technologii net shape.
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The exemplary Kelvin probe microscopy studies of sensitized austenitic stainless steels
Open Research DataThe dataset summarizes the results of imaging the surface potential distribution using the Kelvin probe scanning technique. Due to the fact that the potential measured in this way is proportional to the electrochemical potential of metals or intermetallic phases, it is possible to assess the nobility differences of various alloy components. In the case...
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Failure analysis of the exhaust valve face in diesel marine engine
PublicationThe exhaust valve from marine diesel engine which was damaged after 2000 hours of service was investigated. In order to prolong the service time the valve face was cladded with cobalt base alloy using laser technique. After failure microstructural and chemical analyses reviled that cladding process was conducted improperly. The chemical composition of the clad layer was far from the designed one and what more completely inhomogeneous....
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Some problems of slide bearing material fatigue evaluation.
PublicationA slide bearing alloy resistance against fatigue failures have been investigated for three different lubricants, different heat loadings and different stress ratio κ values. The research methods and data handling procedures for determination of particular parameter effects on fatigue strength have been described and analysed for experiments that were set and performed in laboratory tester SKMR-2. Main and interaction effects of...
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Determination of causes of accelerated local corrosion of austenitic steels in water supply systems
PublicationThis paper concerns an inspection of a water supply system, made of AISI 304 steel, which showed signs of local corrosion at the weld. Such corrosion caused material perforation after very short periods of operation. It was revealed that steel was sensitised during the welding process. It was also proven that chromium micro-segregation occurred in the alloy leading to galvanic cell formation which initialised the process of pitting...
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Kod fontannowy z przyrastającą liczbą symboli źródłowych
PublicationKody fontannowe zabezpieczające transmisję przed wymazaniami wyróżnia brak określonej z góry długości i losowy sposób generacji kolejnych pakietów kodowych. W pracy pokazano jak właściwości tych kodów zależą od rozkładu macierzy generującej dla dwóch wariantów dostarczania pakietów do kodera. Szczególnie interesujący jest przypadek, gdy pakiety źródłowe trafiają do kodera stopniowo podczas transmisji. Uzyskane wyniki wskazują na...
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Glass-ceramic sealants and steel interconnects: accelerated interfacial stability and reactivity tests at high temperature
PublicationHigh-temperature reactions between glass-ceramic sealants and Fe-Cr alloy interconnects may lead to the formation of undesirable phases, and consequently degradation of solid oxide fuel/electrolyser devices. In this work, three different glass-ceramic sealants (Na-containing, Ba-containing, Sr-containing compositions) and Fe22Cr stainless steel powders (raw and pre-oxidised) are considered in order to test their chemical reactivity...
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Vascular stents - materials and manufacturing technologies
PublicationThe objective of this article is to present materials and technology for the manufacture of vascular stents with appropriate design requirements. The use of the right material is very important in implantology. A biomaterial introduced into the circulatory system must be biocompatible and hemocompatible. At the same time, it should not initiate toxic, mutagenic, or immunological reactions. Currently, 316L stainless steel (316L...
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Sharp transitions in low-number quantum dots Bayesian magnetometry
PublicationWe consider Bayesian estimate of static magnetic field, characterized by a prior Gaussian probability distribution, in systems of a few electron quantum dot spins interacting with infinite temperature spin environment via hyperfine interaction. Sudden transitions among optimal states and measurements are observed. Usefulness of measuring occupation levels is shown for all times of the evolution, together with the role of entanglement...
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Wireless intelligent audio-video surveillance prototyping system
PublicationThe presented system is based on the Virtex6 FPGA and several supporting devices like a fast DDR3 memory, small HD camera, microphone with A/D converter, WiFi radio communication module, etc. The system is controlled by the Linux operating system. The Linux drivers for devices implemented in the system have been prepared. The system has been successfully verified in a H.264 compression accelerator prototype in which the most demanding...
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Critical Remarks on Landauer’s principle of erasure– dissipation: Including notes on Maxwell demons and Szilard engines
PublicationWe briefly address Landauer’s Principle and some related issues in thermal demons. We show that an error-free Turing computer works in the zero-entropy limit, which proves Landauer’s derivation incorrect. To have a physical logic gate, memory or information-engine, a few essential components necessary for the operation of these devices are often neglected, such as various aspects of control, damping and the fluctuation–dissipation...
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Hybrid Technique for the EM Scattering Analysis with the Use of Ring Domain Decomposition
PublicationA hybrid technique combining finite-element and mode-matching methods for the analysis of scattering problems in open space is presented here. The main idea is based on impedance matrix descriptions of the boundary surrounding the discrete computational domain and combine it with external field described analytically. The discrete analysis, which is the most time- and memory-consuming, is limited here only to the close proximity...
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Właściwości złączy różnoimiennych stopu niklu Incoloy 800H ze stalą odporną na korozję 316L
PublicationW artykule przedstawiono problemy związane z wykonywaniem połączeń różnoimiennych typu Incoloy 800HT – austenityczna stal odporna na korozję 316L. Wykonano badania nieniszczące oraz niszczące, których wyniki pozwoliły na weryfikacje jakości wykonanych złączy próbnych. Nie stwierdzono występowania niezgodności spawalniczych oraz uzyskano wysokie właściwości wytrzymałościowe złączy. Badania metalograficzne ujawniły poprawne struktury...
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THE USE OF FEM FOR DETERMINATION OF RESONANT FREQUENCIES OF CIRCULAR SAW BLADES WITH INDIRECT TEETH IN GULLETS
PublicationUnderstanding the dynamical properties of the circular saw blade is necessary, since, there is a really need for a stable work at working rotational speeds, which are determined by frequencies at which the circular saw blade tends to vibrate. It was observed that the resonant frequency depend on the circular saw blade shape, a collar diameter and on saw’s teeth shape. In the presented work an attention was paid to the effect of...
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3D printed ABS thermoplastic vs. steel. Dry sliding wear test in constant load & velocity ring on flat configuration. Test parameters: print layer thickness and orientation. Test symbol: 009_v_2
Open Research DataData gathered in sliding ring-on-block (flat contact) tribological experiment. Materials: alloy steel (heat treated) vs. ABS plastic.