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Wyniki wyszukiwania dla: GEAR VIBRATIONS
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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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Relieving the Measuring System of the Trailer for Tyre/Road Rolling Resistance Measurements from the Inertia Force
PublikacjaIn the article the principle of measuring of tyre/road rolling resistance tyres in road conditions applied in a special measuring trailer is presented. This trailer was built in Faculty of Mechanical Engineering at Gdansk University of Technology. The construction of two special devices used in this trailer was discussed. These devices eliminate the influence of some chosen confounding measurements factors such as: the inertia...
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Stability of Discrete Fractional Order State-space Systems
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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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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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Experimental and numerical study on damage detection in an L-joint using guided wave propagation
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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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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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Explanation of Reduction of Pressure Forces in Turbine Chamber Seals
PublikacjaThe paper describes a chamber seal reducing the aerodynamic forces created in shroud seals. Asymmetrical pressure distribution (due to rotor-stator eccentricity) in the blade tip clearance leads to the creation of pressure forces acting on the blade shroud. By increasing the volume above the shroud, the pressure distribution becomes more uniform on the whole shroud circumference and the effect of rotor eccentricity is reduced....
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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 Method of Reduction of Aerodynamic Forces Generated in Turbine Blade Seals
PublikacjaOpisano metodę zmniejszania sił wymuszających drgania aerodynamiczne poprzez zastosowanie nowego uszczelnienia nadbandażowego typu komorowego. Efektywność stosowania uszczelnienia komorowego potwierdzono obliczeniami numerycznymi i badaniami eksperymentalnymi.
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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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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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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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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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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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Enhancement of self-trapped excitons and near-infrared emission in Bi3+/Er3+ co-doped Cs2Ag0.4Na0.6InCl6 double perovskite
Dane BadawczeErbium (Er) complexes are used as optical gain materials for signal generation in the telecom C-band at 1540 nm, but they need a sensitizer to enhance absorption. Na+ substitution for Ag+ and Bi3+ doping at the In3+ site is a possible strategy to enhance the broadband emission of Cs2AgInCl6, which could be used as a sensitizer for energy transfer to...
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Number of commercial banks at the end of the year, excluding banks that are not operating, bankrupt or liquidated, and banks in organization in 1993-2004
Dane BadawczePolish banks were gradually transformed from enterprises with a predominance of Polish private capital into banks with a majority share of private foreign capital. In 1993, there were 48 banks with a majority of Polish private capital, and in 2006 there were 7 of them. In 1993, the shares of 10 banks in Poland were owned by private foreign capital,...
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Gdańsk University of Technology graduates’ self-assessment of selected digital competencies by gender – the year 2017, part I
Dane BadawczeThe dataset includes data from the survey on the Gdańsk University of Technology graduates' from the year 2017 on their self-assessment of selected digital competencies by gender. The survey was conducted in 2019, two years after the respondents obtained graduate status. The research sample included 1594 respondents. To summarize, in general, respondents...
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Gdańsk University of Technology graduates’ self-assessment of selected digital competencies by gender – the year 2018, part I
Dane BadawczeThe dataset includes data from the survey on the Gdańsk University of Technology graduates' from the year 2018 on their self-assessment of selected digital competencies by gender. The survey was conducted in 2020, two years after the respondents obtained graduate status. The research sample included 1315 respondents. To summarize, in general, respondents...
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Gdańsk University of Technology graduates’ self-assessment of selected digital competencies by gender – the year 2016, part I
Dane BadawczeThe dataset includes data from the survey on the Gdańsk University of Technology graduates' from the year 2016 on their self-assessment of selected digital competencies by gender. The survey was conducted in 2018, two years after the respondents obtained graduate status. The research sample included 1947 respondents. To summarize, in general, respondents...
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Gdańsk University of Technology graduates’ self-assessment of selected digital competencies by gender – the year 2018, part II
Dane BadawczeThe dataset includes data from the survey on the Gdańsk University of Technology graduates' from the year 2018 on their self-assessment of selected digital competencies by gender. The survey was conducted in 2020, two years after the respondents obtained graduate status. The research sample included 1315 respondents. To summarize, in general, respondents...
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Gdańsk University of Technology graduates’ self-assessment of selected digital competencies by gender – the year 2017, part II
Dane BadawczeThe dataset includes data from the survey on the Gdańsk University of Technology graduates' from the year 2017 on their self-assessment of selected digital competencies by gender. The survey was conducted in 2019, two years after the respondents obtained graduate status. The research sample included 1594 respondents. To summarize, in general, respondents...
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Gdańsk University of Technology graduates’ self-assessment of selected digital competencies by gender – the year 2016, part II
Dane BadawczeThe dataset includes data from the survey on the Gdańsk University of Technology graduates' from the year 2016 on their self-assessment of selected digital competencies by gender. The survey was conducted in 2018, two years after the respondents obtained graduate status. The research sample included 1947 respondents. To summarize, in general, respondents...
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Gdańsk University of Technology graduates’ self-assessment of selected digital competencies by gender – the year 2016, part II
Dane BadawczeThe dataset includes data from the survey on the Gdańsk University of Technology graduates' from the year 2016 on their self-assessment of selected digital competencies by gender. The survey was conducted in 2018, two years after the respondents obtained graduate status. The research sample included 1947 respondents. To summarize, in general, respondents...
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Gdańsk University of Technology graduates’ self-assessment of selected digital competencies by gender – the year 2017, part I
Dane BadawczeThe dataset includes data from the survey on the Gdańsk University of Technology graduates' from the year 2017 on their self-assessment of selected digital competencies by gender. The survey was conducted in 2019, two years after the respondents obtained graduate status. The research sample included 1594 respondents. To summarize, in general, respondents...
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Gdańsk University of Technology graduates’ self-assessment of selected digital competencies by gender – the year 2017, part II
Dane BadawczeThe dataset includes data from the survey on the Gdańsk University of Technology graduates' from the year 2017 on their self-assessment of selected digital competencies by gender. The survey was conducted in 2019, two years after the respondents obtained graduate status. The research sample included 1594 respondents. To summarize, in general, respondents...
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Gdańsk University of Technology graduates’ self-assessment of selected digital competencies by gender – the year 2016, part I
Dane BadawczeThe dataset includes data from the survey on the Gdańsk University of Technology graduates' from the year 2016 on their self-assessment of selected digital competencies by gender. The survey was conducted in 2018, two years after the respondents obtained graduate status. The research sample included 1947 respondents. To summarize, in general, respondents...
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Gdańsk University of Technology graduates’ self-assessment of selected digital competencies by gender – the year 2018, part II
Dane BadawczeThe dataset includes data from the survey on the Gdańsk University of Technology graduates' from the year 2018 on their self-assessment of selected digital competencies by gender. The survey was conducted in 2020, two years after the respondents obtained graduate status. The research sample included 1315 respondents. To summarize, in general, respondents...
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Gdańsk University of Technology graduates’ self-assessment of selected digital competencies by gender – the year 2018, part I
Dane BadawczeThe dataset includes data from the survey on the Gdańsk University of Technology graduates' from the year 2018 on their self-assessment of selected digital competencies by gender. The survey was conducted in 2020, two years after the respondents obtained graduate status. The research sample included 1315 respondents. To summarize, in general, respondents...
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Middle ear, nasal cavity and accessory sinuses - Unknown, 0 - Tissue image [11280630007414171]
Dane BadawczeThis is the histopathological image of OTHER AND ILL-DEFINED SITES tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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Middle ear, nasal cavity and accessory sinuses - Unknown, 0 - Tissue image [11280630007416951]
Dane BadawczeThis is the histopathological image of OTHER AND ILL-DEFINED SITES tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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Middle ear, nasal cavity and accessory sinuses - Unknown, 0 - Tissue image [11280630007412671]
Dane BadawczeThis is the histopathological image of OTHER AND ILL-DEFINED SITES tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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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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Investigation of natural frequencies of axially loaded thin-walled columns
PublikacjaThe paper deals with correlation between natural frequencies of two steel thin-walled columns and the corresponding applied load. The structures are made of cold-formed lipped channel sections. The columns lengths were assumed to follow two buckling patterns – global flexural and flexural-torsional buckling. In the thicker structure two material models were considered – linearly-elastic and elastic-perfectly plastic. Numerical...
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Sliding burnishing technology of holes in hardened steel
PublikacjaNew technology with sliding burnishing of holes with cylindrical surface, made of hardened steel /60 HRC/, is presented in the paper.After burnishing operation on hole diameter 30 mm in satellite gear wheel the surface roughness parameter Ra=0,02-0,04 micrometers was obtained. The method and results of research as technological conclusion are presented.
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Measurement system for nonlinear surface spectroscopy by atomic force microscopy for corrosion processes monitoring
PublikacjaIn addition to traditional imaging the surface, atomic force microscopy (AFM) enables wide variety of additional measurements. One of them is higher harmonic imaging. In tapping mode the nonlinear contact between tip and specimen results in higher frequency vibrations. More information available from the higher harmonics analysis proves to be helpful for more detailed imaging. Such visualization is especially useful for heterogeneous...
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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)...
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Wave Method for Structural Health Monitoring: Testing Using Full-Scale Shake Table Experiment Data
PublikacjaAn algorithm of the wave method for structural health monitoring (SHM) is tested and calibrated using shake table experiment data of a full-scale, seven-story, reinforced-concrete building slice. The method is based on monitoring changes in the velocity of waves propagating vertically through the structure, identified by least-squares (LSQ) fit of beam models. The experiment was conducted by a team from the University of California,...
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RAPORT - EKSPERTYZA Z POMIARÓW DRGAŃ LINII WAŁÓW NA JEDNOSTCE ORP „DĄBIE”
PublikacjaEkspertyza diagnostyczna dotycząca stanu technicznego dwóch linii transmisji mocy (linii wałów) opracowana na podstawie przeprowadzonych pomiarów drgań w 26 punktach pomiarowych, przy jednoczesnej pracy silników napędowych L i PB (wspólnej pracy linii wałów obu burt), w II zakresach ustalonego obciążenia „pół-naprzód” i „cała-naprzód”. Pomiary prędkości i przyspieszeń drgań generowanych przez węzły konstrukcyjne okrętowego układu...
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A technique of experiment aided virtual prototyping to obtain the best spindle speed during face milling of large-size structures
PublikacjaThe paper presents an original method concerning vibration suppression problem during milling of large-size and geometrically complicated workpieces with the use of novel way of selecting the spindle speed. This consists in repetitive simulations of the cutting process for subsequent values of the spindle speed, until the best vibration state of the workpiece is reached. An appropriate method of obtaining a computational model,...
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Józef Pacyna prof. dr hab. inż.
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