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Laboratorium Drgań i Zjawisk Falowych 2023/Laboratory of vibrations and wave phenomena 2023
Kursy Online -
Laboratorium Drgań i Zjawisk Falowych 2024/Laboratory of vibrations and wave phenomena 2024
Kursy Online -
On the deformation and frequency analyses of SARS-CoV-2 at nanoscale
PublikacjaThe SARS-CoV-2 virus, which has emerged as a Covid-19 pandemic, has had the most significant impact on people's health, economy, and lifestyle around the world today. In the present study, the SARS-CoV-2 virus is mechanically simulated to obtain its deformation and natural frequencies. The virus under analysis is modeled on a viscoelastic spherical structure. The theory of shell structures in mechanics is used to derive the governing...
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In search of a new relationship between nature and society
PublikacjaWe live in an era of breakthrough- not only in the literal sense of the word, but the breakthrough of the century or the millennium. New discoveries and the crisis present in the economy, society, religion and ecology forces a review of all universally accepted theories. Nature, ecology and environment are the key words used in every area of human activity. It has led to the development of a new scientific field- the philosophy...
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Incremental construction of Minimal Tree Automata [online]
PublikacjaWe describe an algorithm that allows the incremental addition or removal of unranked ordered trees to minimal frontier-to-root deterministic tree automaton (DTA). The algorithm takes a tree t and a minimal DTA A as input; it outputs a minimal DTA A' which accepts the language L(A) accepted by A incremented (or decremented) with the tree t. The algorithm can be used to efficiently maintain dictionaries which store large collections...
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An implementation of deterministic tree automata minimization
PublikacjaWstępujący, deterministyczny, skończony automat drzewiasty (DTA) może być używany jako struktura danych do przechowywania zbiorów nieuporządkowanych drzew bez narzuconej liczby poddrzew. Takie automaty są zwykle rzadsze niż automaty działające na napisach i dlatego należy zwrócić szczególną uwagę na ich wydajną minimalizację. W dostępnej literaturze jest jednak ciężko znaleźć proste i szczegółowe opisy procedury minimalizacji....
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On the well posedness of static boundary value problem within the linear dilatational strain gradient elasticity
PublikacjaIn this paper, it is proven an existence and uniqueness theorem for weak solutions of the equilibrium problem for linear isotropic dilatational strain gradient elasticity. Considered elastic bodies have as deformation energy the classical one due to Lamé but augmented with an additive term that depends on the norm of the gradient of dilatation: only one extra second gradient elastic coefficient is introduced. The studied class...
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Skilled-Unskilled Wage Gap Versus Evolving Trade And Labour Market Structures in the EU
PublikacjaThis paper proposes an alternative approach to the empirical study of wage gap between workers with different educational levels in the enlarged EU. The analysis is based on sectoral database, linking labor market statistics and trade data at the level of 12 manufacturing sectors in a group of 20 European countries: selected New Member States (NMS-5) and former EU-15 economies, in the period 1995-2005. The results of the empirical...
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Justyna Szostak dr inż.
OsobyI Gdańsk University of Technology: Chair of the Rector’s Internationalization Committee (October 2020 - Present) Erasmus + Coordinator for students and staff members, Faculty of Applied Physics and Mathematics (Mar 2017 - Present) Dean's Proxy for Internationalization, Faculty of Applied Physics and Mathematics (October 2020 - Present) Coordinator of the International Relations Office of the Faculty of Applied Physics and...
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The influence of the temperature treatment method on the quality of French fries.
Dane BadawczeThe video presents instructional work on the temperature treatment of French fries and the assessment of oil changes during frying. The results of the measurements show that placing the fries in cold oil, heating them to the frying temperature compared to the conventional method of frying, reduces the amount of primary oxidation products and free fatty...
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Fabrication and Structural Properties of LaNb 1‐x As x O 4 Ceramics
PublikacjaLanthanum niobate substituted with arsenic was synthesized by three methods: solid state reaction from binary oxides and two different methods combining co-precipitation and solidstate reaction. In the first of the combined methods LaNb1- xAsxO4 was synthesized from LaAsO4, obtained from coprecipitation method, and lanthanum and niobium oxides. In the second LaNbO4 was first synthesized from binary oxides and then mixed with LaAsO4...
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Yade-open DEM: an open-source software using a discrete element methodto simulate granular material
PublikacjaPurpose - YADE-OPEN DEM is an open source software based on the Discrete Element Method which uses object oriented programming techniques. The paper describes the softwarearchitecture.Design/methodology/approach - The DEM chosen uses position, orientation, velocity and angular velocity as independent variables of simulated particles which are subject to explicit leapfrog time-integration scheme (Lagrangian method). The three-dimensional...
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EXPERIMENTAL STUDY OF A TEMPORARY STEEL GRANDSTAND UNDER CROWD LOAD
PublikacjaTemporary structures, such as grandstands, are commonly used during different types of mass events, especially sport and music concerts. In this paper, the results of the experimental study on temporary steel grandstand are presented. The aim of the investigation was to determine modal characteristics of such structures. Modes of free vibrations and corresponding natural frequencies have been obtained for empty and occupied grandstand....
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Hybrid quantum-classical approach for atomistic simulation of metallic systems
PublikacjaThe learn-on-the-fly (LOTF) method [G. Csanyi et al., Phys. Rev. Lett. 93, 175503 (2004)] serves to seamlessly embed quantum-mechanical computations within a molecular-dynamics framework by continual local retuning of the potential's parameters so that it reproduces the quantum-mechanical forces. In its current formulation, it is suitable for systems where the interaction is short-ranged, such as covalently bonded semiconductors....
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Nanostructure and dielectric behavior of vanadate glasses containing BaTiO3
PublikacjaThe ac and dc electrical conductivity of barium titanate doped bismuth-vanadate as-quenched and heat-treated materials was measured in the frequency range from 1 mHz to 1 MHz and in the temperature range from 153 K to 423 K with the impedance spectroscopy method. The microstructure was investigated by means of XRD, scanning electron microscopy (SEM), atomic force microscopy (AFM) and confocal microscopy. The obtained results showed...
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New Trends in Sample Preparation Techniques for the Analysis of the Residues of Pharmaceuticals in Environmental Samples
PublikacjaPharmaceutical residues in the environment is a field of special interest due to the adverse effects to either human health or aquatic and soil environment. Pharmaceuticals have been already detected in underground, surface and wastewaters, soils, manure and sediments. The growing awareness of environmental pollution arising from human activity forces the need for their comprehensive determination. Environmental samples are complex...
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Effect of surface on the flexomagnetic response of ferroic composite nanostructures; nonlinear bending analysis
PublikacjaOur analysis incorporates the geometrically nonlinear bending of the Euler-Bernoulli ferromagnetic nanobeam accounting for a size-dependent model through assuming surface effects. In the framework of the flexomagnetic phenomenon, the large deflections are investigated referring to von-Kármán nonlinearity. Employing the nonlocal effects of stress coupled to the gradient of strain generates a scale-dependent Hookean stress-strain...
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Analysis of the effect of the seismic gap on the response of buildings experiencing pounding during earthquakes
PublikacjaThe aim of this paper is to investigate the effect of the seismic gap on the dynamic response of buildings experiencing earthquake-induced pounding. Three buildings have been analysed, which are 5-storey, 7-storey and 9-storey structures. Three possible pounding scenarios have been considered, which are pounding between 5-storey and 7-storey buildings, pounding between 5-storey and 9-storey buildings and pounding between 7-storey...
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Thermal Instability of Gold Thin Films
PublikacjaThe disintegration of a continuous metallic thin film leads to the formation of isolated islands, which can be used for the preparation of plasmonic structures. The transformation mechanism is driven by a thermally accelerated diffusion that leads to the minimalization of surface free energy in the system. In this paper, we report the results of our study on the disintegration of gold thin film and the formation of nanoislands...
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The dynamic analysis of a cracked Timoshenko beam by the spectral element method
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Longitudinal wave propagation. Part I—Comparison of rod theories
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Wave propagation in a sensor/actuator diffusion bond model
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Longitudinal wave propagation. Part II—Analysis of crack influence
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Wave propagation modelling in 1D structures using spectral finite elements
PublikacjaW artykule omówiono modele propagacji fal wzdłużnych i poprzecznych w prętach oparte na dwóch sformułowaniach (w dziedzinie częstości i w dziedzinie czasu) metody elemntów spektralnych. Porównano otrzymane wyniki z wynikami eksperymentu.
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Modelling of wave propagation in composite plates using the time domain spectral element method
PublikacjaW pracy przedstawiono wyniki obliczeń propagacji fali sprężystej w płycie kompozytowej modelowanej z wykorzystaniem czasowego sformułowania metody elementów spektralnych
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Experimental and numerical study on damage detection in an L-joint using guided wave propagation
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Stability of Discrete Fractional Order State-space Systems
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Assessment of rod behavior theories used in spectral finite element modeling
PublikacjaW pracy przedstawiono teorie prętów i przedstawiono ich przydatnośc w analizie propagacji fal sprężystych z wykorzystaniem metody spektralnych elementów skończonych.
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Experimental and numerical study on damage detection in an L-joint using guided wave propagation
PublikacjaW pracy zaprezentowano metodę wykrywania i lokalizacji uszkodzeń w konstrukcji ramowej za pomocą podłużnych i poprzecznych fal sprężystych. Przeprowadzono badania numerczyne i eksperymentalne na modelu bez uszkodzenia oraz na modelu z wsprowadzonym nacięciem. Do modelowania zastosowano metodę elementów spektralnych. W pracy przedstawiono sformułowanie nowego element spektralnego dla ram płaskich bazującego na teorii pręta Mindlina...
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Longitudinal wave propagation. Part II, Analysis of crack influence
PublikacjaW pracy analizowano wpływ pęknięć zmęczeniowych na propagacje fali wzdłużnej w prętach. Opracowano nowe typy element ów spektralnych oparte na teorii elementarnej, Love'a, Mindlina i trójpostaciowej.
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Longitudinal wave propagation. Part I - Comparison of rod theories
PublikacjaW pracy przedstawiono modele spektralnych elementów skończonych do analizy propagacji fali wzdłuznej w pretach. Opracowano modele wykorzystujace teorię elementarną, teorie Love'a, teorie Mindlina oraz teorię trójpostaciową.
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The dynamic analysisi of cracked Thimoshenko beam by the spectral element method.
PublikacjaW pracy przedstawiono model belli Timoshenko z pęknięciem poprzecznym oparty o metodę elementów spektralnych. Przedstawiono wyniki propagacji fali sprężystej i jej interakcję z pęknięciem.
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Assessment of flexural beam behaviour theories used for dynamics and wave propagation problems
PublikacjaW pracy przedstawiono i porównano teorie belek zginanych począwszych od teorii elementarnych, aż do teorii wyższych rzędów. Przedstawiono krzywe dyspersi dla poszczególnych teorii i na ich podstawione oszacowano zakres stosowalności danej teorii.
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Pressure Pulsations in Turbine Blade Seal
PublikacjaThe paper presents the results of experimental investigations into pressure forces generated in a turbine labyrinth seal. The experiments were performed on a single-stage air model turbine of the impulse type. The performed experimental research proved that in a shroud clearance the pressure pulsates and the effects of the nozzle trailing edge thickness as well as the influence of the rotor blades are observed. The exemplary results...
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Performance Characteristics of a Micro-Turbine
PublikacjaIn the paper a design of a multi-stage micro-turbine with partial admission of all the stages is described in detail and the results of particular experimental investigations and numerical calculations are shown, followed by conclusions. The co-generative micro-power plant with the HFE7100 as a working medium was designed and built for experimental investigations. The values of the main cycle parameters were as follows:heat output:...
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Partial Admission Stages of High Efficiency for a Microturbine
PublikacjaThe paper presents the results of a design analysis of a microturbine for a cogeneration micro-power plant working in accordance with organic Rankine cycle. The heat power of the plant is assumed equal to 20kW and the corresponding available electric output is estimated to be about 3 kW. After the design analysis, the axial turbine with partial admission in all stages was built and tested experimentally. Special attentionwas paid...
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Fast bubble dynamics and sizing
PublikacjaSingle bubble sizing is usually performed by measuring the resonant bubble response using the Dual Frequency Ultrasound Method. However, in practice, the use of millisecond-duration chirp-like waves yields nonlinear distortions of the bubble oscillations. In comparison with the resonant curve obtained under harmonic excitation, it was observed that the bubble dynamic response shifted by up to 20 percent of the resonant frequency...
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High frequency dynamics of an isotropic Timoshenko periodic beam by the use of the Time-domain Spectral Finite Element Method
PublikacjaIn this work results of numerical simulations and experimental measurements related to the high frequency dynamics of an aluminium Timoshenko periodic beam are presented. It was assumed by the authors that the source of beam structural periodicity comes from periodical alterations to its geometry due to the presence of appropriately arranged drill-holes. As a consequence of these alterations dynamic characteristics of the beam...
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Considerations about the applicability of the Reynolds equation for analyzing high-speed near field levitation phenomena
Publikacjaequation for analyzing near field levitation (NFL) phenomena. Two separate approaches were developed, experimentally verified, and applied to meet the research objective. One was based on the Reynolds equation and the other was based on general conservation equations for fluid flow solved using computational fluid dynamic (CFD). Comparing the calculation results revealed that, for certain operating conditions, differences in the...
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Novel digitally controlled drive for the vibratory conveyors
PublikacjaThe presented vibratory conveyors is used in the industry for continuous transportation of loose substances over short distances (2-10 m). The conveyor is applied for transportation in aseptic conditions. To obtain high efficiency for granulatedmass with different size of grain and different physical properties it is necessary to set the appropriate vibration amplitudeindependently of vibration frequency. This is not possible with...
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Study on polymer elements for mitigation of earthquake-induced pounding between buildings in complex arrangements
PublikacjaPounding between neighbouring buildings during earthquakes has been identified as one of the reasons for substantial damage or even total collapse of colliding structures, so it has been the subject of numerous studies in the recent years. A major reason leading to interactions between adjacent, insufficiently separated structures results from the differences in their dynamic properties. The problem is much more complicated for...
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Determination of stepped plate thickness distribution using guided waves and compressed sensing approach
PublikacjaGuided waves recently have attracted significant interest as a very promising research area. The signals registered by a specially designed sensor network are processed to assess the state of the tested structure. Despite the constant development of novel damage detection algorithms employing guided waves, the phenomenon of wave propagation still needs detailed recognizing and understanding for the further progress of non-destructive...
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Point cloud based surface analysis of prestressed concrete element in exceeded state of serviceability
PublikacjaBy definition, serviceability state is characterized by the fact that despite meeting the requirements associated with carrying capacity, the object is not suitable for use. Serviceability limit state refers to factors, such as durability, overall stability, fire resistance, cracking, excessive vibration. Perfect examples of exceeded serviceability state are the improper vibration of a skyscraper, which inhabitants may suffer from...
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STABILITY OF THE INNER SLOPE OF THE POLISH DREDGDIKES RESEARCH DIKE AT STATIONARY FLOW
PublikacjaFor long duration of the flood the water table can appear on the slope with a problem of out-wash in the case of sand type dike. If the dike corps is covered with less permeable layer some additional push-off forces and shearing can rise in the cover. In both cases the micro stability of the inner slope should be considered at normative high water for homogeneous sand type dike or sand type dike with less permeable covers. The...
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Anomalous anisotropy of deuterium-grown boron-doped diamond and the role of boron-tetramers in the Mott-Insulator transition
Dane BadawczeWe show anisotropy in the superconductivity for boron-doped diamond thin films prepared with Microwave Plasma Assisted Chemical Vapor Deposition using deuterium-rich plasma. This anomalous phase transition is linked with the emergence of boson quantum entanglement states behaving as a bosonic insulating state. Here, we show that the superconducting...
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Tomasz Maria Boiński dr inż.
OsobyZ uczelnią jestem związany już od 2000r kiedy to rozpocząłem studia na kierunku Informatyka wydziału Elektroniki, Telekomunikacji i Informatyki. Po ich ukończeniu z wyróżnieniem, w 2005 roku rozpocząłem studia doktoranckie. W trakcie studiów i bezpośrednio po ich zakończeniu zaangażowany byłem, we współpracy z firmą Hogart z Warszawy, we wdrażanie rozwiązań biznesowych w gdyńskiej firmie Elektronia S.A. (Infor FMS SunSystems) oraz...
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Drewno w adoptowanym zabytku - studium przypadku. Budynek nr 2 w dawnych koszarach garnizonu we Wrzeszczu
PublikacjaThe current structure along with adapted listed buildings and surroundings will create "Garrison of Culture".This part of Gdańsk and Wrzeszcz has been reconnected after eight decades of isolation from the city by joining the square area formed by Grunwaldzka, Słowackiego, Chrzanowskiego, Szymanowskiego streets and the city center. It is a project whitch fits into an aspect of revitalisation related to the socio-economic and environmental...
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Water-lubricated stern tube bearing - experimental and theoretical investigations of thermal effects
PublikacjaThe paper presents research results of thermal phenomena accompanying operation of a water-lubricated stern tube bearing with axial grooves. Experimental tests revealed, that intensity of forced axial flow has strong influence on bush temperature. Numerical simulations focused on investigation of the thermal phenomena under operation of water-lubricated journal bearing showed, that restricted axial flow promotes backflow of the...
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Renewable and Sustainable Energy: Current State and Prospects
PublikacjaThe last two decades of the twentieth century represented a period of above-average, systematic growth of formal and informal interdependencies between economies of different countries and between world markets. The intensity, magnitude, and diversity of these interdependencies have never been recorded before in economic history, and the market transformations taking place have been referred to in the literature as the process...
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Optical Emission Spectroscopy of Microwave (915 MHz) Plasma in Atmospheric Pressure Nitrogen with Addition of Ethanol Vapour
PublikacjaIn this paper results of optical emission spectroscopic study of microwave 915 MHz plasma in atmospheric pressure nitrogen with an addition of ethanol vapour are presented. The plasma was generated in waveguide- -supplied cylinder-type nozzleless microwave plasma source. The aim of research was to determine the rotational Trot and vibrational Tvib temperatures of CN and C2. A method called bubbling was employed to introduce alcohol (ethanol)...