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The luminescence study of Ga2–x(Al0.68In0.32)xO3:Cr3+ coumpounds.
Open Research DataNear-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs) are a highly efficient perspective NIR light source, with application hindered by a narrow emission band. In this work, we broaden the emission of a new series of NIR phosphors by controlling crystal structure disorder through cation cosubstitution. By substituting Ga3+ with (Al0.68In0.32)3+,...
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The luminescence study ofNaK2Li[Li3SiO4]4:Ce coumpounds.
Open Research DataPhosphors with a rigid and symmetrical structure are urgently needed. The alkali lithosilicate family (A[Li3SiO4]) has been extensively studied with a narrow emission band due to its unique cuboid-coordinated environment and rigid structure. However, here we demonstrate for the first time Ce-doped NaK2Li[Li3SiO4]4 phosphors with a broad emission band,...
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International Cross-Domain Conference for Machine Learning and Knowledge Extraction
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Grzegorz Ronowski dr hab. inż.
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VARIABLE KINEMATICS OF HONING PROCESS – INFLUENCE ON MACHINED WORKPIECE
PublicationSurface quality of holes plays an important role in machine manufacturing industry especially in the production of car engines and hydraulic cylinders. Investigations of honing process were carried out by 6 years on horizontal CNC Sunnen’s honing machine HTH 4000S, on vertical conventional honing machine WMW’s SZS 200 and on CNC milling machine of Haas VF 3SS with equipment of Honingtec for honing. Measurements of cylindricity...
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Two-Rate Based Low-Complexity Variable Fractional-Delay FIR Filter Structures
PublicationThis paper considers two-rate based structures for variable fractional-delay (VFD) finite-length impulse response (FIR) filters. They are single-rate structures but derived through a two-rate approach. The basic structure considered hitherto utilizes a regular half-band (HB) linear-phase filter and the Farrow structure with linear-phase subfilters. Especially for wide-band specifications, this structure is computationally efficient...
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Understanding the Electronic Structure and Optical Properties of Vacancy-Ordered Double Perovskite A2BX6 for Optoelectronic Applications
PublicationOver the past few years, metal halide perovskite solar cells have made significant advances. Currently, the single-junction perovskite solar cells reach a conversion efficiency of 25.7%. Perovskite solar cells with a wide band gap can also be used as top absorber layers in multi-junction tandem solar cells. We examined the dynamical and thermal stability, electronic structure, and optical features of In2PtX 6 (X = Cl, Br, and I)...
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Ryszard Jasiński dr hab. inż.
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The effect of wax foundation addition to PCL filaments on mechanical properties.
Open Research DataThe dataset includes the effect of wax foundation addition on the basic mechanical properties of the filaments. PCL and wax foundation addition at 10 and 15% were used for extrusion. The mechanical properties of the resulting filaments were evaluated by a double compression test using an Instron model 5543 universal testing machine. Parameters such...
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The International Mercury Cartel, 1928–1954: Controlling Global Supply
PublicationThis article describes the features of the international mercury marketduringthe firsthalfofthetwentiethcentury.Itanalyzes the various market agreements made, their effectiveness, and their consequences. The period studied is little understood, although it was one in which mercury production greatly increased. It was also one that saw persistent efforts at market manipulation, owing to a series of agreements between Spanish and...
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Rapid redesign of multiband antennas with respect to operating conditions and material parameters of substrate
PublicationThis work addresses geometry parameter scaling of multi-band antennas for Internet of Things applications. The presented approach is comprehensive and permits re-design of the structure with respect to both the operating frequencies and material parameters of the dielectric substrate. A two-step procedure is developed with the initial design obtained from an inverse surrogate model constructed using a set of appropriately prepared...
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Induction machine model for current diagnostics of bearings. W: [CD-ROM]Proceedings and our Portrait. 48 Internationales Wissenschaftliches Kollo- quium. Ilmenau, 22.-25.09.2003. Ilmenau: Tech. Univ. Ilmenau**2003 s. [1-9] 8 rys. Model maszyny indukcyjnej dla prądowej diagnostyki łożysk.
PublicationPojawienie się określonych typów uszkodzeń w silniku jest źródłem odkształ-cenia tego prądu. Poddając przebieg prądu analizie widmowej obserwuje sięszereg składowych, które związane są z określonymi typami uszkodzeń. Referatprezentuje rezultaty badań modelowych i eksperymentalnych. Badania przepro-wadzono na silniku 1,1 kW czterobiegunowym. Zaprezentowany model pozwala za-równo na wprowadzanie wibracji wirnika jak ekscentryczności...
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Tadeusz Stolarski prof. dr hab. inż.
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The Effect of Welding Conditions on Mechanical Properties of Superduplex Stainless Steel Welded Joints
PublicationThe tests results of superduplex stainless steel welded joints made with a different heat input, using automatic submerged arc welding (SAW) and semi-automatic flux-cored arc welding (FCAW) have been presented. Metallographic examinations, the measurements of the ferrite content, the width of the heat affected zone (HAZ) and the hardness of the welds in characteristic areas have been performed. Significant differences in the amount of...
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Sensorless Control of Polyphase Induction Machines
PublicationThe basics of transformations of polyphase systems into orthogonal systems are explained. Vector models of induction machines in orthogonal planes are analysed and multiscalar models for rotor flux and main flux together with stator current are presented. A speed observer based on an extended model of the induction machine for selected variables is applied in the control system for the induction machine. On the basis of the model...
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Rafał Gawarkiewicz dr inż.
Peopleaby nie dublować informacji, uprzejmie proszę zajrzeć tutaj
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Energy Loss Coefficients ki in a Displacement Pump and Hydraulic Motor used in Hydrostatic Drives
PublicationThe article aims at defining and analysing the energy loss coefficients in design solutions of rotating displacement machines, with a piston machine as an example. The energy losses observed in these machines include mechanical loss, volumetric loss, and pressure loss. The scale and relations between these losses in different machines depend on machine design and manufacturing quality, and on operating parameters. The operating...
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Surface Science - 2021/2022
e-Learning CoursesThe goal of the subject is the presentation of basic problems resulting from he existence of interfacebetween material objects and its surroundings. Discussion of the consequences arising from the existenceof surface energy. Analysis of possible applications of surface phenomena in technology. Understanding ofproblems and benefits resulting from decreasing dimensions of objects with the special emphasis on thesemiconductor band...
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Effect of Linear Energy and Microstructure on the Content of Residual Hydrogen in Welded Joints made of Superduplex Steels
PublicationThe article presents tests concerning the content of retained hydrogen present in FCAW and SAW welded joints made of superduplex steel. The use of various welding technologies resulted in the obtainment of welds having different microstructures and ferrite contents. Measurements of retained hydrogen present in joints (performed using the complete combustion method) revealed various contents of hydrogen in the base material and...
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Ultra-Wideband Vivaldi Antenna with an Integrated Noise-Rejecting Parasitic Notch Filter for Online Partial Discharge Detection
PublicationPower transformers and gas-insulated switchgear (GIS) play crucial roles in electrical power grids. However, they may suffer from degradation of insulation material due to wear and tear, leading to their imminent failure. Partial discharges (PDs) are an initial sign of insulation materials degradation which emit signals spanning various physical domains, including electromagnetic. PDs are temporally narrow, high-frequency, stochastic...
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Control of the wind turbine generator
PublicationWind power system consists of two main parts: wind turbine and electrical generator. Wind turbine converts the energy of the flowing air into mechanical energy, next generator converts this energy into electrical energy that is sent to the power system. These two processes should be realized with maximum efficiency and the following requirements for the control system can be formulated: opti-mal wind power conversion, compensation...
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Sample Rate Conversion Based on Frequency Response Masking Filter
PublicationThe sample rate conversion with high resampling ratios requires low-pass digital filters with very narrow transition band which results in high computational complexity and makes filter design problematic. Therefore in this work we propose to use the FRM method, which breaks the filter with a narrow transition band into a group of filters with reduced design requirements. These decreases the number of non-zero coefficients and...
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Dynamic state assessment of the water turbine with the power of 600 kW
PublicationThe article discusses the results of experimental studies to assess the dynamic state of the turbine set with the Kaplan turbine. The dynamic assessment was made on the basis of appropriate standards, based on the measurement results of selected parameters of vibration, which have been measured for several states of the machine load. In addition, we attempted to identify the causes of the increased vibration levels based on the...
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Influence of the presence of rhamnolipids and ionic cross-linking conditions on the mechanical properties of alginate hydrogels.
Open Research DataThe dataset contains the results of determination the effect of rhamnolipids concentration, calcium chloride concentration and ionic cross-linking time on the mechanical properties of alginate hydrogels prepared by immersing the alginate mixture limited by the dialysis membrane in an appropriate cross-linking solution containing calcium ions. The mechanical...
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Deep learning for ultra-fast and high precision screening of energy materials
PublicationSemiconductor materials for energy storage are the core and foundation of modern information society and play important roles in photovoltaic system, integrated circuit, spacecraft technology, lighting applications, and other fields. Unfortunately, due to the long experiment period and high calculation cost, the high-precision band gap (the basic characteristic parameter) of semiconductor is difficult to obtain, which hinders the...
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Optical measurements of lithium titanate sol-gel derived thin films
Open Research DataNanocrystalline 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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Rheological Problems of Technical Fabirc
PublicationW pracy przedstawiono wyniki identyfikacji modeli Chaboche'a i Schapery dla tkaniny technicznej Panama.
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Methods of material parameters identification for isotropic damage in viscoplastic flow conditions
PublicationW pracy zaprezentowano trzy metody identyfikacji parametrów materiałowych dla izotropowego zniszczenia w warunkach lepkoplastycznego płynięcia. Przedstawiono wyniki identyfikacji dla dwóch stopów aluminium, które następnie zweryfikowano porównując wyniki symulacji numerycznych z wynikami eksperymentalnymi.
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Constructional properties of polycarbonate plates for EURO 2012 Gdansk stadium
PublicationPrzedstawiono wyniki badań doświadczalnych dla płyt z poliwęglanu litego, które miały zostać wykorzystane jako materiał konstrukcyjno-osłonowy stadionu piłkarskiego na mistrzostwa Euro 2012 w Gdańsku. Zidentyfikowano moduł Younga oraz Poissona, wykonano próby cykliczne oraz pełzania. Właściwości mechaniczne poliwęglanu litego oceniono jako dobre, choć obawy budzą mikrorysy pojawiające się podczas badań w strukturze materiału.
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On finite element modelling of architectural fabrics for hanging roofs
PublicationArtykuł dotyczy modelowania konstytutywnego i identyfikacji parametrów materiałowych dla tkanin technicznych powszechnie stosowanych w konstrukcjach membranowo-cięgnowych. Autorzy przedstawiają krótką charakterystyke modeli stosowanych w opisie zachowania sie tkanin technicznych. Opisano metodę do idetyfikacji nieliniowo-sprężystych właściwości tkanin technicznych. Dodatkowo dokonao porówania wyników z prób jednoosiowego rozciągania...
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Experimental research on technical fabric of the Forest Opera Roof in Sopot
PublicationThe experimental analysis of the technical fabric Valmex is presented. The study involves uniaxial tensile, cyclic, rheological and biaxial tests. Some of the main differencies between two types of the analysed material have been identified. Mechanical properties of the textile have been modeled by the viscoelastic standard model with quite good effect.
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Regression points in non-intrusive polynomial chaos expansion method and D-optimal design
PublicationThe paper addresses selected issues of uncertainty quantification in the modelling of a system containing surgical mesh used in ventral hernia repair. Uncertainties in the models occur e.g. due to variability of abdominal wall properties among others. In order to include them, a non-intrusive regression-based polynomial chaos expansion method is employed. Its accuracy depends on the choice of regression points. In the study a relation...
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Detection and segmentation of moving vehicles and trains using Gaussian mixtures, shadow detection and morphological processing
PublicationSolution presented in this paper combines background modelling, shadow detection and morphological and temporal processing into one system responsible for detection and segmentation of moving objects recorded with a static camera. Vehicles and trains are detected based on their pixellevel difference from the continually updated background model utilizing a Gaussian mixture calculated separately for every pixel. The shadow detection...
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Identification of nonlinear viscoelastic properties of the ''Panama'' fabric
PublicationTkanina techniczna Panama wytwarzana przez firmę Sattler (Niemcy)wykazuje cechy nieliniowe w tym właściwości lepkosprężyste w czasie testów długoterminowych. Na podstawie jednoosiowych testów płynięcia i regeneracji przeprowadzonych dla pięciu poziomów obciążenia przeprowadzono identyfikacje nieliniowych lepkosprężystych właściwości tkaniny. Do opisu zależności konstytutywnych użyto całkowego modelu Schapery'ego. Zastosowano funkcję...
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Diagnostics of induction motors by means of current supplying measurements
PublicationSkładowe prądu zasilającego silnik, które związane są z uszkodzeniami łożysk są małe w porównaniu z dominującą składową sieciową. Zaproponowano układ pomiarowy do ich pomiaru i przedstawiono wyniki badań diagnostycznych na obiektach rzeczywistych.
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Identification of inertia, damping and stiffness parameters for low pressure steam turbine framework.
PublicationW pracy przedstawiono metodę identyfikacji masy tłumienia i sztywności kadłuba części niskoprężnej turbiny parowej 200MW.
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On topology optimization of large deformation contact-aided shape morphing compliant mechanisms
PublicationA topology optimization approach for designing large deformation contact-aided shape morphing compliant mechanisms is presented. Such mechanisms can be used in varying operating conditions. Design domains are described by regular hexagonal elements. Negative circular masks are employed to perform dual task, i.e., to decide material states of each element and also, to generate rigid contact surfaces. Each mask is characterized by...
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Method of Monitoring of the Grinding Process with Lapping Kinematics Using Audible Sound Analysis
PublicationUtilising microphones as audible sound sensors for monitoring a single-side grinding process with lapping kinematics is presented in the paper. The audible sound generated during grinding depended on the cutting properties of electroplated tools with D107 diamond grains and different thicknesses of the nickel bond. The tool wear affected the obtained technological effects such as material removal rate and the surface roughness...
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Distinctive properties of Scots pine (Pinus sylvestris L.) originating from the Carpathian and Great Poland-Pomeranian of Nature and Forest Land
PublicationIn this paper values of properties of Scots pine, the fracture toughness and of shear yield stress in the shear zone are presented. Samples of Scotch pine (Pinus sylvestris L.) wood of two provenances from Poland were tested. These properties were determined from the values of cutting power obtained experimentally on the saw frame PRW-15M. The values of fracture toughness and shear yield stress based on the Atkins model for cutting...
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Ryszard Katulski prof. dr hab. inż.
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Marek Chodnicki dr inż.
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Włodzimierz Przybylski prof. dr inż.
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Rafał Hein dr hab. inż.
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Marek Dzida dr hab. inż.
PeopleHe was born on 6 August 1953 in Bielsko-Biała. He is a graduate of the Institute of Shipbuilding at Gdańsk University of Technology. Since 1978 he has been working at Faculty of Ocean Engineering and Ship Technology at GUT. In 1983 he received the title of Doctor of Technical Sciences, and in 2001 – the title of Doctor with habilitation. He is currently employed as Associate Professor at GUT. He worked as vice-dean for Education...
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Spurious Modes in Model Order Reduction in Variational Problems in Electromagnetics
PublicationIn this work, we address an everlasting issue in 2 model order reduction (MOR) in electromagnetics that has 3 remained unnoticed until now. Contrary to what has been 4 previously done, we identify for the very first time spurious 5 modes in MOR for time-harmonic Maxwell’s equations and 6 propose a methodology to remove their negative influence on the 7 reduced order model (ROM) response. These spurious modes 8 have nonzero resonance...
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UKŁAD PRZENIESIENIA NAPĘDU TURBINY WIATROWEJ
PublicationIn a most commonly met design of a wind turbine the power is transmitted from the rotor to the generator through the system composed of the main shaft, friction connection, multiplicating gearbox and a flexible coupling. The driving system comprises almost a complete set of the machine elements being described during machine design lectures and can serve as an interesting illustration of the lectures.
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The Influence of Limiters UEL and OEL (The power angle, stator's current and excitation current) ot the possibility of voltage collapse development
PublicationVoltage stability has been a major concern for power system utilities because of event of voltage collapses in the recent past. Sometimes, power system events have shown the need for generators to operate in the overexcited and underexcited region to support stable operation. Modern excitation systems include devices for controlling or limiting machine terminal voltage (overvoltage limiters), volts per hertz ratio (V/Hz limiters),...
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RF Input-Quasi-Reflectionless Dispersive-Delay Structures Based on Complementary-Diplexer Circuits
PublicationA class of RF dispersive-delay structures (DDSs) with input-quasi-reflectionless behavior is reported. It is based on the exploitation of complementary-diplexer circuit networks, in which the out-of-band RF-input-power echoes reflected by the main bandpass-filter-(BPF)-type channel are dissipated by the resistively-terminated auxiliary bandstop-filter-(BSF)-type channel. Specifically, it is shown that the influence of the absorptive...
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Possibilities of using SVC compensators for synchronous generators rotors oscillations damping.
PublicationThe article presents the idea of using static var compensators (SVC) for damping generators rotors oscillations. A novel SVC controller structure is proposed to provide better dynamic performance of the power system. A tests results are shown for proposed controller structure, that was carried out in a three-machine power system model as well as in multi-machine model of Polish Power System.
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Multiple reference frame theory in the synchronous generator model considering harmonic distortions caused by nonuniform pole shoe saturation
PublicationThe paper describes a synchronous generator model developed based on the multiple reference frame theory. The main physical phenomena included in the model are the machine armature non-sinusoidal voltage waveform and the influence of armature current in load conditions on the armature voltage waveform higher harmonic components. The modified multiple reference frame theory model is proposed. In this modified theory model the field...