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Superstable magnetic nanoreactors with high efficiency for Suzuki-coupling reactions
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Changes in bacterial cells induced by high pressure at subzero temperature
PublicationW publikacji przedstawiono wyniki badań dotyczące zmian jakie zachodzą w komórkach bakterii Escherichia coli po działaniu wysokiego ciśnienia w ujemnej temperaturze. Stwierdzono, że w wyniku działania ciśnienia 193 MPa zachodzącą zmiany w błonie cytoplazmatycznej i ścianie komórkowej bakterii. W tych warunkach następowała prawie całkowita utrata wewnątrzkomórkowego ATP z komórek badanych szczepów znajdujących się w fazie logarytmicznej....
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Formation of High Corrosion Resistant Nanotubular Layers on TitaniumAlloy Ti13Nb13Zr
PublicationThis paper presents results of oxidation tests and corrosion investigations of titanium alloy Ti13Nb13Zr performed at different conditions. The oxide layers have been formed by electrochemical method in 2M H3PO4 + 0.3% HF solution for 30 min. and 1 h at 20 V constantvoltage. The corrosion tests have been made by potentiodynamic method in Ringer`s solution at pH ranged between 3 and 7. It has been shown that the nano-oxide films,...
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High Growth Aspirations of Nascent Entrepreneurs: Why Do They Fall?
PublicationIntention-based research become more and more popular in various domains, including entrepreneurship. Achieving growth by a business must be planned or at least consciously accepted by the business owner. That is why it is vital to take growth intentions into account when trying to predict growth of business. Personal attitude of an entrepreneur towards growth is important from the very beginning of business operations or even...
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The wear of PVD coated elements in oscillation motion at high temperature
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Formation of High Corrosion Resistant Nanotubular Layers on TitaniumAlloy Ti13Nb13Zr
PublicationThis paper presents results of oxidation tests and corrosion investigations of titanium alloy Ti13Nb13Zr performed at different conditions. The oxide layers have been formed by electrochemical method in 2M H3PO4 + 0.3% HF solution for 30 min. and 1 h at 20 V constantvoltage. The corrosion tests have been made by potentiodynamic method in Ringer`s solution at pH ranged between 3 and 7. It has been shown that the nano-oxide films,...
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High temperature linear impedance of 35P2O5-30Fe2O3-35Nb2O5
Open Research DataThe high temperature electrical properties of phosphate-iron glasses containing niobium were investigated. Glass samples of the composition of 35P2O5-30Fe2O3-35Nb2O5 (in %mol) were prepared by the conventional melt quenching technique. Appropriate amounts of reagents ((NH4)2HPO4 (≥99.9%, POCH), Fe2O3 (≥99.9%, POCH), Nb2O5 (≥99.9%, PLUKA AG) and TiO2...
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Design of High-Performance Scattering Metasurfaces through Optimization-Based Explicit RCS Reduction
PublicationThe recent advances in the development of coding metasurfaces created new opportunities in realization of radar cross section (RCS) reduction. Metasurfaces, composed of optimized geometries of meta-atoms arranged as periodic lattices, are devised to obtain desired electromagnetic (EM) scattering characteristics. Despite potential benefits, their rigorous design methodologies are still lacking, especially in the context of controlling...
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Ograniczenie trwałości skojarzeń ceramicznych w wyniku propagacji pęknięć powierzchniowych = Fatigue life limitation of ceramic materials due to surface crack propagation
PublicationPrzedstawiono krótką analizę literaturową dotyczącą mechanizmów propagacji pęknięć w materiałach ceramicznych oraz wyniki dotychczasowych badań doświadczalnych wybranych materiałów ceramicznych z uwzględnieniem wpływu pęknięć powierzchniowych na trwałość ceramicznych skojarzeń tocznych.
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Energy, water detailed usage. Living lab testing for sustainable urban food-water-energy cycle.
Open Research DataData set contains detailed, continuous measurements of the usage of water and electrical energy (AC power) in an experimental facility set up in a scientific laboratory (Laboratorium im. B.Niemkiewicza) at the Faculty of Mechanical Engineering and Ocean Technology of the Gdansk University of Technology. The test bed was established in co-operation...
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Investigation of low-temperature cracking in newly constructed high-modulus asphalt concrete base course of a motorway pavement
PublicationThe paper presents the issue of low-temperature transverse cracks which have developed in newly constructed base courses made of high-modulus asphalt concrete mix (HMAC). Numerous transverse cracks developed in the analysed HMAC base during the winter season before the pavement was actually completed, both at the transverse joint locations and in the areas between them. This had not happened so far on such a scale during road construction...
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High resolution X-ray diffractometry and reflectometry of semiconductor nano- and micro- structures based on X-ray refractive optics
PublicationIn this thesis proposed, discussed and studied novel synchrotron X-ray diffractometry and reflectometry methods based on a refractive optics. The experimental results obtained from the ID06 beamline at ESRF, Grenoble, France are presented and analyzed in this work to demonstrate a high angular and space resolution in addition to the opportunity to manage in situ and on operando experiments with the help of proposed X-ray optical...
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Polymer journal bearings behaviour research under limited lubrication and cooling conditions conducted on high torque test rig
PublicationPolymer journal bearings are frequently used as a water-lubricated bearings of small marine units’ propeller shafts . Choice of these bearings is based on their simple construction and relatively low purchase and maintenance costs. Although properly designed and installed water lubricated bearings may well last for over a decade, rapid wear or failure of these bearings can be observed...
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Nitrogen removal in vertical flow constructed wetlands: influence of bed depth and high nitrogen loadings
PublicationThe aim of the study was to evaluate the nitrogen removal and its effects on the plant’s growth and leaves morphology. using two subsurface vertical flow (VF bed), with different depths (0.24 m2 × 0.70 m; 0.24 m2 × 0.35 m) and nitrogen load increments. The VF bed were planted with Vetiveria zizanioides, filled with light expanded clay aggregates (Leca®NR 10/20) and fed in parallel mode with synthetic wastewater. High ammonium nitrogen...
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Comparative analysis of thermodynamic cycles of selected nuclear ship power plants with high-temperature helium-cooled nuclear reactor
PublicationThis paper presents a comparative analysis of thermodynamic cycles of two ship power plant systems with a high-temperature helium- cooled nuclear reactor. The first of them is a gas system with recuperator , in which classical gas chamber is substituted for a HTGR reactor (High Temperature Gas-cooled Reactor) . The second of the considered cycles is a combined gas-steam system where working medium flux from gas turbine outlet...
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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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On the Application of Magnetoacoustic Emission for a Nondestructive Assessment of the Post Welding Heat Treatment of High Chromium Steel Weld Seams
PublicationThe paper analyses the possibility of post weld heat treatment (PWHT) quality assessment with the help of magnetoacoustic emission (MAE) signal measurements. Two welded superheater tubes, made of high chromium VM12 steel, were analysed—as welded and heat treated one. The analysed sample in the as welded state exhibited significantly higher hardness, accompanied by a big difference in the MAE signal intensity (of order of about...
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Metallurgical characterization and high-temperature tensile failure of Inconel 617 alloy welded by GTAW and SMAW—a comparative study
PublicationTwo types of the weld joint of Inconel 617 alloy were produced using gas tungsten arc welding (GTAW) and shielded metal arc welding (SMAW) processes with ERNiCrCoMo-1 filler metal and ENiCrCoMo-1 electrode, respectively. The weld metal showed the segregation of the principle alloying elements like Mo and Cr along the inter-dendritic spaces, triggering the formation of secondary phases. The microstructure characterization of the...
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Modeling the impact of discretizing rotor angular position on computation of field-oriented current components in high speed electric drives
PublicationModern drives consist of alternating current electric motors, and the field-oriented control (FOC) of such motors enables fast, precise, and robust regulation of a drive's mechanical variables such as torque, speed, and position. The control algorithm, implemented in a microprocessor, requires feedback from motor currents, and the quality of this feedback is essential to a drive's control properties. Motor phase currents are sampled...
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Novel Complementary Multiple Concentric Split Ring Resonator for Reliable Characterization of Dielectric Substrates with High Sensitivity
PublicationAccurate characterization of dielectric substrates with high sensitivity remains an important challenge in a variety of industrial applications. This paper proposes an innovative strategy to address this challenge by developing and optimizing a unique Complementary Multiple Concentric Split Ring Resonator (CMC-SRR). The major goal is to propose a sensor design with increased sensitivity and reliability for dielectric characterization....
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NON-LOCAL VOLUMETRIC APPROACH TO ANALYSIS DEFECT'S SHAPE INFLUENCE ON SPECIMENS DURABILITY SUBJECTED TO BENDING AND TORSION
PublicationThe influence of defect features on fatigue behaviour is a complex trivial issue. Although the important advances over the last decades, the dialectical relationship between the defect orientation and durability is not clearly understood. The paper aims at studying the influence of the orientation of elliptical defects on the durability of samples made of C45 steel. Three types of samples with elliptical defects were subjected...
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HIGH PERFORMANCE POLYMERS
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A novel approach to enhance high optically active L-lactate production from food waste by landfill leachate
PublicationThe recycling of food waste (FW) through anaerobic fermentation into lactic acid (LA), with two isomers L-LA and D-LA, aligns with the principles of a bio-based circular economy. However, FW fermentation is often limited by competing pathways, acidification inhibition, and trace metals deficiency. This study investigates the introduction of landfill leachate, containing buffering agents (ammonia) and trace metals, into FW fermentation....
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Support Materials of Organic and Inorganic Origin as Platforms for Horseradish Peroxidase Immobilization: Comparison Study for High Stability and Activity Recovery
PublicationIn the presented study, a variety of hybrid and single nanomaterials of various origins were tested as novel platforms for horseradish peroxidase immobilization. A thorough characterization was performed to establish the suitability of the support materials for immobilization, as well as the activity and stability retention of the biocatalysts, which were analyzed and discussed. The physicochemical characterization of the obtained...
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Impressions about people with intellectual disability of Polish high school students who participated in a workshop led by self-advocates
PublicationThe research question is whether participation in a two-session workshop led by self-advocates with mild intellectual disability, supported by professional staff, affects high school students’ impression of people with intellectual disability, measured by a self-report questionnaire based on a semantic differential. The study was paper-pencil questionnaire-based and anonymous, conducted in Warsaw, Poland. Three measurements...
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Comparative Study of Pavement Rehabilitation Using Hot in-Place Recycling and Hot-Mix Asphalt: Performance Evaluation, Pavement Life Prediction, and Life Cycle Cost Analysis
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Changes in enzymatic activity of fish and slaughter animals meat after high pressure treatment at subzero temperatures
PublicationThe aim of this study was to determine changes in the activity of proteolytic enzymes and transglutaminase of fish and mammal meat after pressurization at subzero temperatures. The activity was measured at the optimal pHs determined for enzymes from particular types of tested meat. It was found that increasing the pressure in the range of 60–193 MPa, did not change significantly the activity of acidic proteases of cod flesh, while...
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Mateusz Kopec Dr hab. inż.
PeopleHead of the Materials and Structural Testing Laboratory in Institute of Fundamental Technological Research PAS and Academic visitor in Imperial College London. Lecturer and Master/PhD students supervisor in Doctoral School of IPPT PAN and TIB PAN, and Imperial College London. Member of Polish Materials Science Society, Member of the Board of Polish Society of Theoretical and Applied Mechanics, and Council Member of the European...
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Numerical Study on Seismic Response of a High-Rise RC Irregular Residential Building Considering Soil-Structure Interaction
PublicationThe objective of the present study is to investigate the importance of soilstructure interaction effects on the seismic response of a high-rise irregular reinforced-concrete residential building. In order to conduct this research, a detailed three-dimensional structure model was subjected to various earthquake excitations, also including a strong mining tremor. Soil-foundation flexibility was represented using the spring-based...
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Analysis of Induced Voltages and Power Losses in High Voltage Power Cables for Selected Methods of Cables Sheaths Bonding
PublicationPower is increasingly supplied to city centres with 110 kV cable lines. This is a convenient way to supply power, and practically the only one possible in areas of dense urban development. A high-voltage cable contains a coaxial metallic sheath, in which in normal operation and in fault conditions (during short-circuits) significant line-to-earth voltages can be induced, which threatens electric shock and/or damage to the cable’s...
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Ground lemon and stevia leaves as renewable functional fillers with antioxidant activity for high-density polyethylene composites
PublicationThe development of new sustainable material solutions in the processing of thermoplastic polymers concerns both the application of biopolymers and the use of valorized plant derivatives as fillers and modifiers of petrochemical polymers. Herein, the possibility of using unprocessed raw parts of two commonly used in the food industry leaves, i.e., lemon (LL) and stevia (ST), as active and functional fillers for high-density polyethylene...
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Metamaterial-Based Series-Fed Antenna with High Gain and Wideband Performance for Millimeter Wave Spectrum Applications
PublicationThis paper presents a high-gain, wideband series-fed antenna designed for 5G millimeter-wave (MMW) applications. The structure employs a substrate-integrated waveguide (SIW)-based power splitter and metamaterials (MMs). The power divider functions effectively at 27.5 GHz, exhibiting an impedance bandwidth from 26.9–28.6 GHz. The series-fed dipole is assembled on the SIW-based power splitter, incorporating four dipoles with varying...
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High temperature linear impedance of 35P2O5-30Fe2O3-27.5Nb2O5-7.5TiO2
Open Research DataThe high temperature electrical properties of phosphate-iron glasses containing niobium were investigated. Glass samples of the composition of 35P2O5-30Fe2O3-27.5Nb2O5-7.5TiO2 (in %mol) were prepared by the conventional melt quenching technique. Appropriate amounts of reagents ((NH4)2HPO4 (≥99.9%, POCH), Fe2O3 (≥99.9%, POCH), Nb2O5 (≥99.9%, PLUKA AG)...
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High temperature linear impedance of 35P2O5-30Fe2O3-25Nb2O5-15TiO2
Open Research DataThe high temperature electrical properties of phosphate-iron glasses containing niobium and titanium were investigated. Glass samples of the composition of 35P2O5-30Fe2O3-20Nb2O5-15TiO2 (in %mol) were prepared by the conventional melt quenching technique. Appropriate amounts of reagents ((NH4)2HPO4 (≥99.9%, POCH), Fe2O3 (≥99.9%, POCH), Nb2O5 (≥99.9%,...
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Wind Conditions at Pedestrian Level in Different Types of Residential Urban Development for a High Degree of Land Use Efficiency
PublicationThe paper concerns wind conditions around urban building development at the pedestrian level. The article aims to identify aerodynamic phenomena around three types of multi-family housing developmentswith different forms and the same urban parameters of building development intensity (high intensity was taken into account). The aim of the research was mainly to achieve qualitative results that would lead to understanding fundamental...
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Experimental and theoretical study on high-temperature creep of VT6 titanium alloy under multi-axial loading conditions
PublicationIn the framework of damage mechanics, we discuss a new mathematical model that describes the kinetics of the stress–strain state and damage accumulation during material degradation by the mechanism of long-term strength under complex multiaxial stress state. An experimental and theoretical technique is proposed for determination of material parameters and scalar constitutive functions for damaged media based on specially set experiments...
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Application of normal-phase high-performance liquid chromatography followed by gas chromatography for analytics of diesel fuel additives
PublicationThe paper presents the results of investigations on new procedures of determination of selected cleaning additives in diesel fuel. Two procedures: one-step analysis using gas chromatography with flame ionization detection (GC-FID) or mass spectrometry (GC-MS) and a two-step procedure in which normal-phase high-performance liquid chromatography (NP-HPLC) was used for preliminary separation of the additives, were compared. The additive...
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Optimal conditions of naphthoquinones separation from carnivorous plants extracts using thin-layer chromatography and high performance liquid chromatography
PublicationDroseraceae plants are owned by the family of carnivorous plants, which in an unusual way adapt to environments poor in nutrients. Droseraceae obtain essential nutrients catching insects and other small invertebrantes. Plumbagin, chloroplumbagin, ramentaceon and droseron are naphthoquinones, which could be found in leaves and shoots of plants from Droseraceae family. In the literature there are a lot of information about the pharmacological...
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Synchronized six-step voltage generation in high-speed PMSM drive
PublicationSynchronized voltage generation has already been considered in the context of pulse width modulation (PWM). References prove that synchronized PWM substantially decreases subharmonics in inverter output voltage when operating with low switching-to-fundamental frequency ratio. This paper identifies problems of unsynchronized voltage generation in electric drives under six-step inverter operation. Guidelines for the synchronization...
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The Course and the Effects of Agricultural Biomass Pyrolysis in the Production of High-Calorific Biochar
PublicationThe thermal pyrolysis of agriculture biomass has been studied in a fixed-bed reactor, wherethe pyrolysis was conducted at a steady temperature of 800◦C. This work analyses the pyrolysisproducts of six agricultural wastes: pistachio husks, walnut husks, sunflower hulls, buckwheat husks,corncobs and coconut shells. The conducted research compared examples of large waste biomassstreams from different parts of the world as a potential...
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The effect of cable duct diameter on the ampacity of high-voltage power cables
PublicationThe ampacity of power cables depends, among others, on the conditions of heat dissipation from the cable to the environment. Cables are usually laid directly in the ground, but in some sections, they may be placed in ducts, which adversely affects the ampacity of the cable line. The paper presents heat transfer phenomena for cables installed in pipe-type ducts filled with air. The effect of cable duct diameter on this ampacity...
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High-resolution microscopy assisted mechanical modeling of ultrafine electrospun network
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High power, medium voltage, modular active power filtering system
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Future hosts for fast and high light output cerium-doped scintillator
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Perspective of High Energy Heating Implementation for Steel Surface Saturation with Carbon
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High Performance Tubular Heat Exchanger with Minijet Heat Transfer Enhancement
PublicationIn the paper, the original cylindrical heat exchanger with minijets (MJHE) was introduced. The systematic experimental analysis of the prototype heat exchanger was described with special attention paid to such parameters as the heat transfer effectiveness, heat transfer rates, overall heat transfer coefficients, and pressure drop. The heat transfer coefficients were determined based on Wilson plot method, the most suitable approach...
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Large dynamic range high frequency fully differential CMOS transconductanceamplifier.
PublicationW pracy zaproponowano nową koncepcję układową w pełni różnicowego wzmacniacza transkonduktancyjnego CMOS o dużym zakresie dynamiki i szerokim pasmie częstotliwości. Przeprowadzone badania teoretyczne i symulacyjne potwierdziły małe zniekształcenia harmoniczne (THD), szerokie pasmo przenoszonych częstotliwości oraz duży zakres dynamiki dla sygnałów różnicowych.
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Elastic electron scattering by argon in the vicinity of the high-energy critical minimum.
PublicationZostały obliczone różniczkowe przekroje czynne na sprężyste rozpraszanie elektronów na argonie. Przedział energetyczny rozpraszanych elektronów został tak dobrany, aby zbadać położenie tzw. minimum krytycznego.
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Influence of deformation velocity on mechanical properties of high strength structural steels.
PublicationW referacie przedstawiono wyniki badań własności mechanicznych stali wysokiej wytrzymałości przeznaczonych na spawane konstrukcje okrętowe w zależności od prędkości odkształcenia. Badania były prowadzone w Akademii Marynarki Wojennej oraz w Politechnice Gdańskiej przy współudziale Uniwersytetu Technicznego w Rostocku podczas opracowywania charakterystyk tych stali dla potrzeb polskiego przemysłu okrętowego. Uwzględnienie obciążeń...
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Factors determining the production testing of high reliability interference supressor capacitors.
PublicationPrzyjęto nieliniowości i właściwości szumowe kondensatora jako kryteria selekcji kondensatorów przeciwzakłóceniowych na klasy o zróżnicowanej niezawodności. Poprawia to proces oceny jakości kondensatorów o podwyższonej niezawodności. Przedstawiono zastosowanie technik pomiaru nieliniowości i szumów w systemie do produkcyjnego testowania kondensatorów przeciwzakłóceniowych o podwyższonej niezawodności. Przytoczono wybrane wyniki...