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Whether Carbon Nanotubes Are Capable, Promising, and Safe for Their Application in Nervous System Regeneration. Some Critical Remarks and Research Strategies
PublikacjaCarbon nanotubes are applied in or considered for different fields of medicine. Among them is the regeneration or rebuilding of nervous system components, which still lack substantial progress; this field is supported by carbon nanotubes to a great extent as the principal material. The limited research on this issue has involved PU/silk/MWCNTs, PCL/silk/MWCNTs, PCL/PGS/CNTs, chitin/CNTs, PGF/CNTs, CNTs/PGFs/PLDLA,MWCNTs chitosan,MWCNTs/PPy,...
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Investigating the Effects of Geometrical Parameters of Re-Entrant Cells of Aluminum 7075-T651 Auxetic Structures on Fatigue Life
PublikacjaIn this study, the effects of two geometrical parameters of the re-entrant auxetic cells, namely, internal cell angle (θ) and H/L ratio in which H is the cell height, and L is the cell length, have been studied on the variations of Poisson’s ratio and fatigue life of Aluminum 7075-T6 auxetic structures. Five different values of both the H/L ratio and angle θ were selected. Numerical simulations and fatigue life predictions have...
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Nanotubular Oxide Layer Formed on Helix Surfaces of Dental Screw Implants
PublikacjaSurface modification is used to extend the life of implants. To increase the corrosion resistance and improve the biocompatibility of metal implant materials, oxidation of the Ti-13Nb- 13Zr titanium alloy was used. The samples used for the research had the shape of a helix with a metric thread, with their geometry imitating a dental implant. The oxide layer was produced by a standard electrochemical method in an environment of...
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Characterization of Arctic Driftwood as Naturally Modified Material. Part 1: Machinability
PublikacjaArctic driftwood has reached the coast of Iceland for centuries. This material was used by the inhabitants of the island as a building material for houses, boats, churches and pasture fences. Nowadays, the driftwood is used in the furniture industry, for the finishing of internal and external walls of buildings and also by artists. The properties of driftwood differ to that of original resource due the long-term effects of exposure...
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Insightful Analysis of Phenomena Arising at the Metal|Polymer Interphase of Au-Ti Based Non-Enzymatic Glucose Sensitive Electrodes Covered by Nafion
PublikacjaThis paper focuses on the examination of glucose oxidation processes at an electrode material composed of gold nanoparticles embedded in a titanium template. Three dierent conditions were investigated: the chloride content in the electrolyte, its ionic conductivity and the presence of a Nafion coating. The impact of the provided environment on the oxidation reaction was evaluated by cyclic voltammetry (CV) and electrochemical impedance...
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The mechanisms of degradation of titanium dental implants
PublikacjaTitanium dental implants show very good properties, unfortunately there are still issues regarding material wear due to corrosion, implant loosening, as well as biological factors—allergic reactions and inflammation leading to rejection of the implanted material. In order to avoid performing reimplantation operations, changes in the chemical composition and/or modifications of the surface layer of the materials are used. This research...
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The Influence of Thin Gold Electrodes on the High-Temperature Impedance of Oxide Glasses
PublikacjaThe influence of thin gold electrodes on the electrical measurements of glasses at high temperatures was studied using impedance spectroscopy. The impedance was measured several times over a wide frequency range from 10 mHz to 1 MHz and the temperature ranged from 213 to 673 K under air and nitrogen atmospheres. The results showed a drop in the conductivity of more than an order of magnitude at a temperature around 603 K during...
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Ultra Low Noise Poroelastic Road Surfaces
PublikacjaNoise is one of the most important environmental problems related to road traffic. During the last decades, the noise emitted by the engines and powertrains of vehicles was greatly reduced and tires became a clearly dominant noise source. The article describes the concept of low noise poroelastic road surfaces that are composed of mineral and rubber aggregate bound by polyurethane resin. Those surfaces have a porous structure and...
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Integration of Fluorescent, NV-Rich Nanodiamond Particles with AFM Cantilevers by Focused Ion Beam for Hybrid Optical and Micromechanical Devices
PublikacjaIn this paper, a novel fabrication technology of atomic force microscopy (AFM) probes integrating cantilever tips with an NV-rich diamond particle is presented. Nanomanipulation techniques combined with the focused electron beam-induced deposition (FEBID) procedure were applied to position the NV-rich diamond particle on an AFM cantilever tip. Ultrasonic treatment of nanodiamond suspension was applied to reduce the size of diamond...
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Coffee Wastes as Sustainable Flame Retardants for Polymer Materials
PublikacjaDevelopment of green flame retardants has become a core part of the attention of material scientists and technologists in a paradigm shift from general purpose to specific sustainable products. This work is the first report on the use of coffee biowastes as sustainable flame retardants for epoxy, as a typical highly flammable polymer. We used spent coffee grounds (SCG) as well as SCG chemically modified with phosphorus (P-SCG)...
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Study of Slip Effects in Reverse Roll Coating Process Using Non-Isothermal Couple Stress Fluid
PublikacjaThe non-isothermal couple stress fluid inside a reverse roll coating geometry is considered. The slip condition is considered at the surfaces of the rolls. To develop the flow equations, the mathematical modelling is performed using conservation of momentum, mass, and energy. The LAT (lubrication approximation theory) is employed to simplify the equations. The closed form solution for velocity, temperature, and pressure gradient...
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Evaluation of the Cathodic Electrodeposition Effectiveness of the Hydroxyapatite Layer Used in Surface Modification of Ti6Al4V-Based Biomaterials
PublikacjaThe important issue associated with the design and the fabrication of the titanium and titanium alloy implants is the increase of their biointegration with bone tissue. In the presented paper, the research results concerning the conditions used in the cathodic deposition of hydroxyapatite on the surface Ti6Al4V substrates primarily modified by the production of TiO2 nanoporous coatings, TiO2 nanofibers, and titanate coatings, are...
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Evaluation of organic coating systems for corrosion protection of industrial equipment using impedance spectroscopy
PublikacjaThe high economic impact of corrosion can be reduced by enhanced corrosion management and prevention based on appropriate means. This applies in particular to the protection of structures with organic protective coatings. Steel is subject to corrosion that reduces its service life and leads to destruction in most severe cases. The application of paints to metallic objects for corrosion control has been known for a long time and...
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Influence of yttria surface modification on high temperature corrosion of porous Ni22Cr alloy
PublikacjaProtective coatings for porous alloys for high temperature use are relatively new materials. Their main drawback is high temperature corrosion. In this work protective coatings based the on Y-precursor infiltrated into the sintered Ni22Cr alloys are studied at 700°C. Effects of the amount of the protective phase on the resulting corrosion properties are evaluated in air and humidified hydrogen. Weight gain of the samples, their...
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Wpływ zawartości grafitu na właściwości mechaniczne warstw hybrydowych Ni-P/Si3N4/grafit osadzonych na stopie AW-7075 metodą redukcji chemicznej.
PublikacjaPrzedstawiono wpływ obecności grafitu jako fazy dyspersyjnej na właściwości mechaniczne warstw hybrydowych Ni-P/Si3N4/grafit, które osadzono metodą redukcji chemicznej na stopie glinu AW-7075. Wykonano badania morfologii powierzchni warstw metodą mikroskopii świetlnej i skaningowej. Dalszą część pracy stanowiły badania mechaniczne, czyli pomiary mikrotwardości warstw oraz ich adhezji do aluminiowego podłoża, a także analizy wpływu...
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Carboxy derivative of dioxydiphenylpropane diglycydyl ether monomethacrylate as an addtive for composites
PublikacjaThe modifier of composites was used in the presence of polyetylene polyamine. Physico-mechanical properties and chemical stability of coatings thus obtained were analyzed.
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Comprehensive Evaluation of the Biological Properties of Surface-Modified Titanium Alloy Implants
PublikacjaAn increasing interest in the fabrication of implants made of titanium and its alloys results from their capacity to be integrated into the bone system. This integration is facilitated by different modifications of the implant surface. Here, we assessed the bioactivity of amorphous titania nanoporous and nanotubular coatings (TNTs), produced by electrochemical oxidation of Ti6Al4V orthopedic implants’ surface. The chemical composition...
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Maciej Jerzy Głowacki
OsobyMaciej Jerzy Głowacki jest absolwentem Politechniki Gdańskiej. Ukończył z wyróżnieniem studia inżynierskie na Wydziale Mechanicznym (2017) oraz studia magisterskie na Wydziale Elektroniki, Telekomunikacji i Informatyki (2018). Od 2014 roku jest nieprzerwanie zaangażowany w działalność badawczą prowadzoną w Katedrze Metrologii i Optoelektroniki. W pracy naukowej zajmował się m. in. nanoszeniem antybakteryjnych powłok hydroksyapatytowych...
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Remote learning among students with and without reading difficulties during the initial stages of the COVID-19 pandemic
PublikacjaThis article presents the results of a survey on yet under-researched aspects of remote learning and learning difficulties in higher education during the initial stage (March – June 2020) of the COVID-19 pandemic. A total of 2182 students from University of Warsaw in Poland completed a two-part questionnaire regarding academic achievements in the academic year 2019/2020, living conditions and stress related to learning and pandemic,...
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State and control system variables sensitivity to rotor asymmetry in the induction motor drive
PublikacjaThe aim of this paper is to undertake analysis and comparison of the closed-loop and sensorless control systems sensitivity to the broken rotor for diagnostic purposes. For the same vector control system induction motor drive analysis concerning operation with the asymmetric motor, broken rotor fault handling and operation were investigated. Reliability, range of stable operation, fault symptoms and application of diagnosis methods...
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Selection of excitation signals for high-impedance spectroscopy
PublikacjaA method of fast impedance spectroscopy of technical objects with high impedance (|Zx| > 1 GOhm) is evaluated in this paper. An object is excited with a signal generated by a digital-to-analog converter (DAC) located on the U2531A DAQ module. Response signals proportional to current flowing through and voltage across the measured object are sampled by analog-to-digital converters (ADC) in the DAQ module. The object impedance spectrum...
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E-technologie w diagnozie i pomiarach postępów terapii dzieci z autyzmem w Polsce
PublikacjaCelem artykułu jest przeanalizowanie możliwości wsparcia technologicznego - w szczególności z wykorzystaniem urządzeń mobilnych - diagnozy i oceny postępów terapii dzieci z autyzmem. W ramach badań dokonano przeglądu istniejących rozwiązań wspierających diagnozę i pomiar postępów terapii oraz przeprowadzono ankietę w polskich ośrodkach zajmujących się pracą z osobami dotkniętymi autyzmem. Wyniki badania wskazują na zainteresowanie...
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Slurry Surfacing Mixes on the Basis of Bitumen Modified with Phenol-Cresol-Formaldehyde Resin
PublikacjaSlow-breaking monophase cationic bitumen emulsions have been produced on the basis of bitumen modified with phenol-cresol-formaldehyde resin (PhCR-F). Bitumen emulsions were used as a binder for thin-layer coatings with slurry surfacing mixes (SSM). Physical and technical parameters of modified and unmodified emulsions were determined and analyzed. The optimal compositions of SSM were selected according to the breaking criterion....
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MOŻLIWOŚCI IDENTYFIKACJI STANU TECHNICZNEGO WARSTW ŚLIZGOWYCH ŁOżYSK SILNIKÓW SPALINOWYCH O ZAPŁONIE SAMOCZYNNYM W PRZYPADKU WYKORZYSTANIA EMISji AKUSTYCZNEJ JAKO SYGNAŁU DIAGNOSTYCZNEGO
PublikacjaW artykule zaprezentowano wyniki badań wielowarstwowych panwi łożysk ślizgowych silników tłokowych. Scharakteryzowano własności obciążeń tego rodzaju panwi oraz ich zużycia szczególnie zmęczeniowego i ściernego. Wykazano przydatność emisji akustycznej jako sygnału diagnostycznego do ujawniania zużycia powłok ślizgowych i zaporowych. Przedstawiono wyniki pomiarów parametrów emisji akustycznej, wykonanych za pomocą 12- kanałowej...
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Studies on applicability of new solid-phase microextraction fibers for the selective extraction and determination of short - chain monocarboksylic acids
PublikacjaShort-chain monocarobxylic acids, sometimes referred to as volatile fatty acids (VFA), are a group of low molecular weight alkyl monocarboxylic acids that are widely distributed within the environment. These molecules contain any from 2 to 8 carbon atoms and originate from the anaerobic biodegradation of organic matter such as carbohydrates, proteins, and fats. These compounds are commonly found in the effluents from animal farming,...
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Assesment of (Mn,Co)3O4powders for possible coating material for SOFC/SOEC interconnects
PublikacjaIn this work (Mn,Co)3O4 spinel powders with different Mn:Co ratio (1:1 and 1:2) and from different commercial suppliers are evaluated for possible powder for production of interconnect coatings. Sinterability of the powders is evaluated on pressed pellets sintered in oxidizing and in reducing/oxidizing atmospheres. For selected powder, coatings are then prepared by the electrophoretic deposition method on Crofer 22 APU stainless...
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Michał Michna dr hab. inż.
OsobyJest absolwentem Wydziału Elektrycznego Politechniki Gdańskiej (1998). W 2004 r. uzyskał stopień doktora. Od 2004 r. zatrudniony w Katedrze Energoelektroniki i Maszyn Elektrycznych Politechniki Gdańskiej (asystent, adiunkt, starszy wykładowca). W latach 2010-2015 zastępca kierownik katedry. Jego zainteresowania naukowe i dydaktyczne obejmują szerokie spektrum zagadnień związanych z projektowanie, modelowanie i diagnostyką maszyn...
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Evaluation of adhesion strength, corrosion, and biological properties of the MWCNT/TiO2 coating intended for medical applications
PublikacjaMulti-wall carbon nanotube (MWCNT) coatings are gaining increasing interest because of their special properties used in many science fields. The titania coatings are known for their improvement of osteoblast adhesion, thus changing the surface architecture. Bi-layer coatings comprising 0.25 wt% of the MWCNTs and 0.30 wt% of titania (anatase structure) were synthesized in a two-stage procedure using the electrophoretic deposition...
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A solution of the integrated µBIST for functional and diagnostic testing in mixed-signal electronic embedded systems
PublikacjaMain problem of the paper is testing of analog circuits and blocks in mixed-signal electronic embedded systems (EESs), using the built-in self-test (BIST) technique. The integrated mBIST based on reusing signal blocks already present in an EES, such as processors, memories, ADCs, is presented. The novelty of the solution is the extended functionality of the mBIST. It can perform 2 testing functions: functional testing and fault...
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Surface finite viscoelasticity and surface anti-plane waves
PublikacjaWe introduce the surface viscoelasticity under finite deformations. The theory is straightforward generalization of the Gurtin–Murdoch model to materials with fading memory. Surface viscoelasticity may reflect some surface related creep/stress relaxation phenomena observed at small scales. Discussed model could also describe thin inelastic coatings or thin interfacial layers. The constitutive equations for surface stresses are...
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ColorNephroNet: Kidney tumor malignancy prediction using medical image colorization
PublikacjaRenal tumor malignancy classification is one of the crucial tasks in urology, being a primary factor included in the decision of whether to perform kidney removal surgery (nephrectomy) or not. Currently, tumor malignancy prediction is determined by the radiological diagnosis based on computed tomography (CT) images. However, it is estimated that up to 16% of nephrectomies could have been avoided because the tumor that had been...
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MCSA with Normalized Triple Covariance as a bearings diagnostic indicator in an induction motor
PublikacjaStatistics of bearing failures in induction motors indicate, that they constitute more than 40% of IM damage, therefore bearing diagnosis is very important. Vibration methods for bearing diagnostics have one major disadvantage - they require the availability of the machine for sensors installation. This is the reason for seeking new methods based on motor supply current analysis. Diagnosis of induction motors, conducted remotely...
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Optical measurements of lithium titanate sol-gel derived thin films
Dane BadawczeNanocrystalline thin films with 800 nm thickness were prepared by sol–gel method. To examine the influence of the annealing time on as-prepared films crystallization, the coatings were heated at 550 °C for 10, 20 and 80 h. On the basis of transmission characteristic optical properties were calculated. It was found that transmission through the thin...
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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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Polyurethanes for Coating, Adhesives, and Other Applications
PublikacjaAn interesting group of polyurethane (PU) materials are coatings, adhesives, sealants, and thickeners. A wide base of raw materials and various methods of PU synthesis allows production of materials with a wide range of properties that can be commonly used in many industries. This chapter describes the main types of PU coatings and adhesives and special application PUs and the methods of their production. The materials described...
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Characteristics of silver-dopped carbon nanotube coating destined for medical applications
PublikacjaCarbon nanotubes are materials demonstrating outstanding mechanical, chemical, and physical properties and are considered coatings of titanium implants. The present research is aimed to characterize the microstructure and properties of the multi-wall carbon nanotubes (MWCNTs) layer decorated with silver nanoparticles (Ag NPs) on the Ti13Nb13Zr alloy destined for long-term implants. The electrophoretic deposition of coatings...
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Zastosowanie sygnałów o projektowanych kształtach do diagnostyki obiektów wysoko-impedancyjnych metodą spektroskopii impedancyjnej
PublikacjaW artykule przedstawiono metodę szybkiej spektroskopii impedancyjnej obiektów o wysokich impedancjach (|Zx| > 1 GOhm) z zastosowaniem sygnałów o projektowanych kształtach. Sygnał pobudzenia wytwarzany jest w module DAQ U2531A i doprowadzany na wejście badanego obiektu za pośrednictwem przetwornika cyfrowo-analogowego (CA). Sygnały odpowiedzi proporcjonalne do napięcia na mierzonej impedancji Zx oraz prądu płynącego przez Zx są...
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Silica-Based Ionogels: Nanoconfined Ionic Liquid-Rich Fibers for Headspace Solid-Phase Microextraction Coupled with Gas Chromatography–Barrier Discharge Ionization Detection
PublikacjaIn this work, hybrid silica-based materials with immobilized ionic liquids (ILs) were prepared by sol–gel technology and evaluated as solid-phase microextraction (SPME) fiber coatings. High loadings of the IL 1-methyl-3-butylimidazolium bis(trifluoromethylsulfonyl)imide ([C4MIM][TFSI]) were confined within the hybrid network. Coatings composition and morphology were evaluated using scanning electron microscopy and energy dispersive...
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Influence of Surface Modification of Titanium and Its Alloys for Medical Implants on Their Corrosion Behavior
PublikacjaTitanium and its alloys are often used for long-term implants after their surface treatment. Such surface modification is usually performed to improve biological properties but seldom to increase corrosion resistance. This paper presents research results performed on such metallic materials modified by a variety of techniques: direct voltage anodic oxidation in the presence of fluorides, micro-arc oxidation (MAO), pulse laser treatment,...
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Hydroxyapatite deposition on the laser modified Ti13Nb13Zr alloy
PublikacjaThe Ti13Nb13Zr alloy was subjected to laser modification with the Nd:YAG laser provided that such treatment would increase the surface roughness followed improved adhesion of hydroxyapatite (HAp) coatings The hydroxyapatite was deposited by electrophoretic method in suspension of 0.5 g HA powder and 100 ml ethyl alcohol. The deposition was carried out for 10 min at 10 V voltage followed by drying at room temperature for 24 h and...
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The determinants of morphology and properties of the nanohydroxyapatite coating deposited on the Ti13Zr13Nb alloy by electrophoretic techniqe
PublikacjaThe titanium and its alloys belong at present to the most preferred and commonly applied biomaterials for load- bearing implants. The surfaces of biomaterials are subjected to modification, including the hydroxyapatite coatings deposited in order to ensure corrosion resistance and better joining between an implant and a bone through the possibility of ingrowth bone into the coating. In this paper, the morphology and properties...
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Rozdział 3.2. W: [Praca zbiorowa] Materiały do monografii przyrodniczej re-gionu gdańskiego. Gdańsk: Marpress**2002 s. 69-70. Tom 8 Diagnoza stanu i koncepcja ochrony środowiska przyrodniczo-kulturowe- go w województwie pomorskim. Diagnosis of natural-cultural environment´scondition and the idea of its protection in Pomeranian Voivodship. Red. A.Kostarczyk, M. Przewoźniak.
Publikacja...
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Tilting pad thrust bearing with novel material selection - experimental comparison of low and medium speed operation
PublikacjaThe advances in material engineering led to the development of hard carbon based coatings applied in numerous applications in order to prevent or minimize wear of the parts in contact. With Triondur® coatings, the bearing company Schaeffler has succeeded in halving the friction losses in the valve trains of passenger cars. The coatings are optimized for high abrasive wear protection and low sliding friction moments. Altogether...
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Protective properties of Al2O3 + TiO2 coating produced by the electrostatic spray deposition method
PublikacjaMechanical resistance of Al2O3 + TiO2 nanocomposite ceramic coating deposited by electrostatic spray deposition method onto X10CrAlSi18 steel to thermal and slurry tests was investigated. The coating was produced from colloidal suspension of TiO2 nanoparticles dispersed in 3 wt% solution of Al2(NO3)3, as Al2O3 precursor, in ethanol. TiO2 nanoparticles of two sizes, 15 nm and 32 nm, were used in the experiments. After deposition,...
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Multidimensional Monitoring System of State Machines
PublikacjaTechnical systems are more complex every day as their electronics and mechanics. Technical advances tend to be autonomous in its performance and perform an auto-diagnosis that allows determining an abnormality existence in a component or subsystem and deciding if the system has to be stopped or not.
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Michał Kowalewski dr inż.
OsobyResearch career: Doctoral dissertation "Tolerance robust, dictionary methods of fault diagnosis of electronic circuits with specialized neural classifier". Participation as a performer in four KBN research teams MNiSW and NCBiR concerning the development of diagnostic methods for analog electronic circuits and diagnostics of technical objects using impedance spectroscopy methods. 39 publications, including 10 in magazines,...
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Metoda diagnostyki łożysk na podstawie analizy przebiegów prądu i napięcia zasilającego silnik indukcyjny.
PublikacjaW niniejszej monografii przedstawiono oryginalne podejście i realizację diagnostyki łożysk silników indukcyjnych przy użyciu metody opartej na pomiarach i analizie iloczynu wartości chwilowych prądu i napięcia zasilającego maszyny. Uzyskane wyniki badań eksperymentalnych na obiektach rzeczywistych okazały się zbieżne z wynikami badań symulacyjnych i potwierdziły, że powstanie uszkodzeń łożysk w silniku skutkuje pojawieniem się...
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Effective yttrium based coating for steel interconnects of solid oxide cells: Corrosion evaluation in steam-hydrogen atmosphere
PublikacjaThis work describes manufacture, analysis and test of a new well conducting corrosion-protection coating that can be applied on steel types with high chromium content. Electrolytic deposition of yttrium salts is used to form thin (<100 nm) coatings on both flat steel sheets (material: Crofer 22 APU) and its properties are proven on woven wire-meshes (materials from two different sources: SUS316 and SUS316L). The oxide scale on...
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Broken rotor symptoms in the sensorless control of induction machine
PublikacjaThe purpose of this paper is to investigate the need for a universal method for sensorless controlled induction motor drive diagnosis. The increasing number of sensorless control systems in industrial applications require a universal method for the drive diagnosis, which provides reliable diagnostic reasoning independent of control system structure and state variables measurement or estimation method.Simulations and experimental...
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Molecularly imprinted polymers for the detection of volatile biomarkers
PublikacjaIn the field of cancer detection, the development of affordable, quick, and user-friendly sensors capable of detecting various cancer biomarkers, including those for lung cancer (LC), holds utmost significance. Sensors are expected to play a crucial role in the early-stage diagnosis of various diseases. Among the range of options, sensors emerge as particularly appealing for the diagnosis of various diseases, owing to their cost-effectiveness,...