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Investigation of noise threats and their impact on hearing in selected schools - a pilot study.
PublicationNoise measurements conducted in selected schools in Gdansk area are presented in this paper. The main aim of this research was to determine noise threats at schools. Some objective measurements of the acoustic climate were performed employing a noise monitoring station engineered at the Multimedia System Department, Gdansk University of Technology. Simultaneously, subjective noise annoyance examinations were carried out among pupils...
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Simulation of electric hearing - influence of simulation parameters on quality of output signal
PublicationW środowisku programistycznym Matlab stworzono symulację słuchu elektrycznego pacjenta implantowanego. W symulacji zastosowano algorytm przetwarzania wykorzystywany w komercyjnych systemach implantów ślimakowych - CIS (Continuous Interleaved Sampling). W pracy zbadano wpływ ilości kanałów, jak i innych parametrów sygnałów wyjściowych przy zastosowaniu sygału mowy jako sygnału wejściowego symulacji.
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Wear measurements of self lubricating bearing materials in small oscillatory movement
PublicationRosnące wymagania ekologiczne powodują wzrost tendencji wymiany klasycznych materiałów łożyskowych, wymagających dodatkowego czynnika smarnego, na materiały nie wymagające smarowania. Zamianie takiej może towarzyszyć obniżenie trwałości zmodernizowanego łożyska. Ten niekorzystny efekt nierzadko obserwuje się w węzłach łożyskowych kierownic turbin wodnych. Autorzy podjęli próbę wyjaśnienia zjawisk występujących w tego typu łożyskach....
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Security information sharing for smart grids: Developing the right data model
PublicationThe smart grid raises new security concerns which require novel solutions. It is commonly agreed that to protect the grid the effective collaboration and information sharing between the relevant stakeholders is prerequisite. Developing a security information sharing platform for the smart grid is a new research direction which poses several challenges related to the highly distributed and heterogeneous character of the grid. In...
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Use of Neural Networks in Diagnostics of Rolling-Element Bearing of the Induction Motor
PublicationBearing defect is statistically the most frequent cause of an induction motor fault. The research described in the paper utilized the phenomenon of the current change in the induction motor with bearing defect. Methods based on the analysis of the supplying current are particularly useful when it is impossible to install diagnostic devices directly on the motor. The presented method of rolling-element bearing diagnostics used indirect...
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Knowledge Sharing and Organizational Culture Dimensions: Does Job Satisfaction Matter?
PublicationThe aim of this study is to examine how job satisfaction influences the relationship between company performance, knowledge sharing, and organizational culture, perceived through the prism of Hofstede’s cultural dimensions, controlled by company size and staff position. A survey of 910 Polish employees (mainly knowledge workers) with different roles and experiences across different industries was conducted. The data were analyzed...
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Effect of Coating Material Properties on Tilting-pad Thrust Bearing Performance
PublicationPolymer lined tilting-pad bearings demonstrate many advantages over traditional bearing systems. Bearings with a polymer layer in comparison with a babbitted layer show, for example: lower value of friction coefficient (important during start/stops), higher fatigue strength of the coating, better distribution of the load on individual pads due to lower elasticity of the polymers, wider range of operational temperatures or the ability...
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Evaluation of expanded uncertainty of instantaneous power measurement in a bearing diagnostic system.
PublicationThe paper presents the issues concerning the estimation of the expanded uncertainty in the system for the diagnosis of rolling bearings, consisting of transducers: voltage and current voltage, which is used for diagnostic bearing motors method based on the measurement and analysis of the instantaneous power signal consumed by the induction motor. It presents the methodology for assessing the measurement uncertainty and presents...
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Noise measurements on low noise pavements - problems with inhomogeneity of wearing course
PublicationDuring the last several years, when performing numerous CPX noise measurements on low noise pavements,significant inhomogeneity of the wearing course was observed in numerous cases. Similar problems were almost not existing regarding to the dense pavements.In general three main reasons of inhomogeneity can be defined. The first one are imperfections in technology of production of a asphalt mix or/and errors made already during...
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Problems of analytical determination of journal bearing bush fatigue strength estimates
PublicationProblems connected with determination of stress distribution in sliding layer of thinwalled bearing bushes, investigated in bearing fatigue test rigs, have been presented. Using an example of plain bearings tested in the fatigue machine SMOK (built at the Gdask University of Technology) problems with obtaining a convergence of iterative procedure for determining the fatigue strength estimators of bearing alloy surface layer are...
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Analysis of Failures of High Speed Shaft Bearing System in a Wind Turbine
PublicationDuring the operation of wind turbines with gearbox of traditional configuration, consisting of one planetary stage and two helical stages high failure rate of high speed shaft bearings is observed. Such a high failures frequency is not reflected in the results of standard calculations of bearing durability. Most probably it can be attributed to atypical failure mechanism. The authors studied problems in 1.5 MW wind turbines of...
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Stochastic model for turbulent lubrication of slide journal bearing in ship technology.
PublicationTurbulentny przepływ smarujący ma zastosowanie w obliczeniach praktycznych siły nośnej poprzecznego łożyska ślizgowego dla wysokich prędkości obrotowych przy liczbach Taylora przekraczających wartość 41,2 względnie przy zmodyfikowanych liczbach Reynoldsa o wartościach Re[psi]=2. Główne wyniki pracy koncentrują się na wykazaniu zmian wartości ciśnienia i siły nośnej poprzecznego łożyska ślizgowego w przypadku turbulentnego, izotemicznego...
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IT- enabled comparison of environmental noise levels and noise-evoked hearing impairments.
Publication[Abstrakt] Tematem pracy jest telemetryczny system monitorowania hałasu, opracowany w katedrze Systemów Multimedialnych Politechniki Gdańskiej, przeznaczony do zdalnego monitorowania poziomów hałasu środowiskowego. Oprócz ogólnej charakterystyki systemu zaprezentowano również szereg szczegółów implementacyjnych. Przedstawiono m.in. mobilne urządzenie pomiarowe, oprogramowanie do pomiarów hałasu, dźwiękowy interfejs USB wyposażony...
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IT- Enabled Comparison of Environmental Noise Levels and Noise-Evoked Hearing Impairments.
PublicationTematem pracy jest telemetryczny system monitorowania hałasu, opracowany w katedrze Systemów Multimedialnych Politechniki Gdańskiej, przeznaczony do zdalnego monitorowania poziomów hałasu środowiskowego. Oprócz ogólnej charakterystyki systemu zaprezentowano również szereg szczegółów implementacyjnych. Przedstawiono m.in. mobilne urządzenie pomiarowe, oprogramowanie do pomiarów hałasu, dźwiękowy interfejs USB wyposażony w mikrofon...
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Metallochromic crown ether analogs bearing aromatic residues and azo groupings
PublicationPraca zawiera przegląd syntezowanych, różnych chromogenicznych związków koronowych, zawierających oprócz dwóch grup azowych i łańcucha polieterowego fragmenty heterocykliczne. Porównano właściwości otrzymanych związków w zależności od obecności heteroatomów w pierścieniu makrocyklicznym oraz różnego podstawienia cząsteczki heterocykliczej.
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ANALYSIS OF THE POSSIBILITIES OF HIGH SPEED SHAFT BEARING SYSTEM DURABILITY INCREASE
PublicationDuring the operation of wind turbines with a gearbox of traditional configuration, a high failure rate of high-speed shaft bearings is observed. Such a high failures frequency is not reflected in standard bearing durability calculation methods, which can be attributed to atypical failure mechanism. To avoid observed problems in the 1.5 MW wind turbine, the modification of the existing bearing system is proposed. Multiple options,...
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Security Requirements and Controls for Incident Information Sharing in the Polish Power System
PublicationAmong the strategies of protecting information assets of the power system, sharing of information about current cybersecurity incidents between energy operators appears to be a prerequisite. Exchange of information leads to the effective detection of attacks and exploited vulnerabilities as well as the identification of countermeasures. This paper presents the results of continuation of our works on developing a secure and efficient...
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Investigation of the IC engine lubricating oil effects on journal bearing life
PublicationPrzedstawiono wyniki modelowych badań eksperymentalnych wytrzymałości zmęczeniowej warstwy ślizgowej łożysk silników spalinowych. W szczególności oceniono wpływ właściwości oleju smarowego na tę wytrzymałość.
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The use of GFRP tubes as load-bearing jackets in concrete-composite columns
PublicationThe paper presents the fields of applications of polymer composites in building structures. The use of composite glass fibre tubes is discussed in more detail. The laboratory methods used to test the mechanical properties of these pipes are presented. An original research program is presented, including six concrete-filled glass fibre tubes. The cylinders and columns made in this way were tested for their axial load capacity. Conclusions...
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Estimation of Screw Displacement Pile-Bearing Capacity Based on Drilling Resistances
PublicationThis article presents an engineering, empiricalmethod of estimating the bearing capacity and settlementcharacteristics Q-s of screw displacement piles andcolumns, based on soil resistance encountered during thedrilling to form piles/columns in the ground. The methodwas developed on the basis of correlation analyses of thetest results of 24 piles made during the “DPDT-Auger”research project (Krasiński et al., 2022a). In the proposedmethod,...
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X-ray images of Baltic herring
Open Research DataA methodology for studying the geometric shape of Baltic herring swimbladders including the optimal way of catching, transporting and storing fish, the X-ray measurements and the X-ray image analysis, that does not change the natural shape of the fish swimbladder was developed. Fish for research was obtained in the area of the Polish coastal zone...
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Vibration data for 1205 EKTN9 bearings
Open Research DataThe data contains measurements of vibration obtained with VIBstand manufactured by EC systems.
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An Approach to Data Reduction for Learning from Big Datasets: Integrating Stacking, Rotation, and Agent Population Learning Techniques
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Energy Efficiency Analysis of Railway Turnout Heating With a Simplified Snow Model Using Classical and Contactless Heating Method
PublicationElectrical heating of railway turnouts is a considerable technical and economic challenge, hence the need to conduct research for optimisation of a railway turnouts heating system. This paper presents results of a numerical analysis and experimental research on heating systems mounted on rail turnouts in line with the classical method and including a heater thermally insulated from the base of a rail. The numerical calculations...
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Study of the Influence of Heat Convection Coefficient on Predicted Performance of a Large Tilting-Pad Thrust Bearing
PublicationPart of the heat generated by the shearing of the lubricating film during operation of a hydrodynamic bearing is transferred to the bearing components. In the case of the pad, which is usually fully submerged in the lubricating oil, heat is further transferred at the pad free walls to the oil by convection. This mechanism causes a thermal gradient in a pad and, consequently, its thermal deflection. In large hydrodynamic thrust...
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Mariusz Kaczmarek dr hab. inż.
PeopleReceived M.Sc., Eng. in Electronics in 1995 from Gdansk University of Technology, Ph.D. in Medical Electronics in 2003 and habilitation in Biocybernetics and Biomedical Engineering in 2017. He was an investigator in about 13 projects receiving a number of awards, including four best papers, practical innovations (7 medals and awards) and also the Andronicos G. Kantsios Award and Siemens Award. Main research activities: the issues...
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ANALYSIS OF WORKING CONDITIONS OF BEARINGS NO.1 & NO.2 OF TURBINE 13K200 AND DESIGN DEVELOPMENT OF NEW BEARINGS FOR THE TURBINE AFTER RETROFITTING
PublicationThe main goal of the work consisted of preparing an analysis of working conditions of bearings No.1 and No.2 in the existing turbine 13K200, as well as designing geometries of new bearings which would allow for their proper functioning in the turbine following its retrofitting (work under higher load).
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Comparison of traditional district heating with low temperature district heating systems featuring organic Rankine cycle and heat pump
PublicationPaper presents a comparison between a traditional district heating system with conventional boilers as a source of heat and electricity purchases from power utilities and a low temperature DH system incorporating the CHP with organic Rankine Cycle providing electricity and local heat pump raising the temperature of the DH fluid to the required temperature in the dwelling, meaning that both heat and electricity are produced within...
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Project and problem-based learning (PPBL): wprowadzenie
EventsZapraszamy na warsztaty, na których m.in. zrozumiesz założenia metody pracą projektu w oparciu o rozwiązywanie realnego problemu, poznasz etapy pracy zespołu metodą projektu oraz rolę nauczyciela i studentów w PPBL.
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Aromatic Dendrimers Bearing 2,4,6-Triphenyl-1,3,5-triazine Cores and Their Photocatalytic Performance
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An introduction to lessons learned and best practices sharing as a chance for improvement in automative corporation
PublicationOmówiono szereg metodologii związanych z poprawą jakości funckjonowania organizacji i zarządzania w przemyśle samochodowym
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the assessment of the noise-induced harmful effects based on the properties of human hearing system
PublicationA new way of assessment of noise-induced harmful effects on human hearing system is presented in the paper. The method takes into consideration properties of the human hearing system. The pro-posed method determines the cumulative impact on hearing system produced by the excessive noise. Based on the predicted effects of the noise exposure, the new types of noise indicators were developed. The evaluation of these indicators was...
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The noise-induced harmful effect assessment based on the properties of the human hearing system
PublicationA new way of assessment of noise-induced harmful effects on human hearing system is presented in the paper. The method takes into consideration properties of the human hearing system. The pro-posed method determines the cumulative impact on hearing system produced by the excessive noise. Based on the predicted effects of the noise exposure, the new types of noise indicators were developed. The evaluation of these indicators was...
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Optical flow method for measuring deformation of soil specimen subjected to torsional shearing
PublicationIn this study optical flow method was used for soil small deformation measurement in laboratory tests. The main objective was to observe how the deformation distributes along the whole height of cylindrical soil specimen subjected to torsional shearing (TS test). The experiments were conducted on dry non-cohesive soil specimens under two values of isotropic pressure. Specimens were loaded with low-amplitude cyclic torque to analyze...
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DESIGN AND THEORETICAL ANALYSIS OF A PROTOTYPE TILTING-PAD RADIAL BEARING WITH ADJUSTABLE CLEARANCE
PublicationThe article introduces a design and analysis results of a prototype ORC (organic Rankine cycle) turbo generator rotor assembly of 300kW power, supported by tilting-pad bearings of original design. The calculations were performed for a prototype turbo generator rotor. The shaft of this machine is supported with two radial bearings, lubricated with an unusual lubricant – a low-boiling-point agent. The main objective of the presented...
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Extended duration running and impulse loading characteristics of an acoustic bearing with enhanced geometry
PublicationThis paper presents performance during prolonged running of the acoustic bearing when PZTs are switched off and when they are switched on. The effect of active PZT on shaft’s displacements in X and Y directions is clearly demonstrated. Performance of the acoustic bearing was also assessed when an impulse force was applied to the running shaft at speed. Once again the benefits of having PZTs active are beyond doubt. The instability...
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Field Tests on Hydrodynamic and Hybrid Operation of a Bidirectional Thrust Bearing of a Pump-Turbine
PublicationIn vertical shaft pump turbines operating in pumped storage power plants an important role is played by a thrust bearing. Due to the bidirectional character of operation, thrust bearing tilting pads have to be supported symmetrically, which is known to be unfavourable from the point of view of their performance. Large thrust bearings have to be carefully designed so as to minimise excessive thermo-elastic pad deformations. The...
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Water-lubricated stern tube bearing - experimental and theoretical investigations of thermal effects
PublicationThe 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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Combined thrust radial bearing of a submarine main shaft – Design and analysis of failure
PublicationThis paper presents an analysis of the combined thrust radial bearing of a submarine propulsion shaft. The lubrication system of the bearing is based on a fixed ring. The efficiency of the lubrication system depends on the shaft speed and temperature, which affects oil viscosity. In turn, the thrust bearing load also depends on the rotational speed of the shaft, because as the speed increases, the drag of the ship increases simultaneously,...
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The influence of time of hearing aid use on auditory perception in various acoustic situations
PublicationThe assessment of sound perception in hearing aids, especially in the context of benefits that a prosthesis can bring, is a complex issue. The objective parameters of the hearing aids can easily be determined. These parameters, however, do not always have a direct and decisive influence on the subjective assessment of quality of the patient’s hearing while using a hearing aid. The paper presents the development of a method for...
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Ecological bearing systems for water turbines – research and development at Gdansk University of Technology
PublicationIncreasing requirements for environmental protection make it necessary to introduce new materials and designs. Hydroelectric power plants operating in direct contact with water reservoirs and rivers are potentially endangering water cleanliness, hence they should also be modernized in the way minimizing the environmental hazards. A lot of progress in this field has been achieved in last decades, but still there is much work to...
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Effect of manufacturing errors of the pad sliding surface on the performance of the hydrodynamic thrust bearing
PublicationIn the present study, investigation of the effect of manufacturing errors on the performance of large tilting pad thrust bearings has been performed, following a CFD-based Thermohydrodynamic analysis of a single pad. A 3D model has been generated, including the pad, the lubricant film and the corresponding part of the collar. The pad has been assumed to be deformed about the pivot point, due to thrust loading. Manufacturing errors...
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A comparative performance assessment of a hydrodynamic journal bearing lubricated with oil and magnetorheological fluid
PublicationThis work presents the investigation results of a journal bearing lubricated with magnetorheological fluid that is activated by a local constant magnetic field to vary both the local flow resistance and pressure. The bearing performance is assessed via Finite Element Modelling (FEM) and results are corroborated by experiments. The FEM model uses the Bingham model to describe the fluid film. A dedicated test rig is used to assess...
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Common-Mode Voltage and Bearing Currents in PWM Inverters: Causes, Effects and Prevention
PublicationIn modern induction motor drives an increase of transistors' switching frequency and a decrease of switching times are the sources of some serious problems. The high dv/dt and the common mode voltage generated by the inverter PWM control results in the appearances of bearing currents, shaft voltages, motor terminal overvoltages, the decrease of motor efficiency, and electromagnetic interference. The aspects of common mode (CM)...
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Developing Novel Solutions to Realise the European Energy - Information Sharing & Analysis Centre
PublicationFor more effective decision making in preparation for and response to cyberevents in the energy sector, multilevel situation awareness, from technical to strategic is essential. With an uncertain picture of evolving threats, sharing of the latest cybersecurity knowledge among all sector stakeholders can inform and improve decisions and responses. This paper describes two novel solutions proposed during the formation of the European...
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Stability and load bearing capacity of a braced truss under upward wind loading
PublicationThe paper is focused on the numerical and experimental investigation of stability of a steel truss under upward wind loading. The structure was stiffened by elastic braces situated at the top and bottom chord. Usually the lateral (translational) brace stiffness is considered. However, the rotational stiffness of braces caused by interaction between torsional stiffness of the truss top chord and bending stiffness of the roof elements...
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Stability and load bearing capacity of a braced truss under upward wind loading
PublicationThe paper is focused on the numerical and experimental investigation of stability of a steel truss under upward wind loading. The structure was stiffened by elastic braces situated at the top and bottom chord. Usually the lateral (translational) brace stiffness is considered. However, the rotational stiffness of braces caused by interaction between torsional stiffness of the truss top chord and bending stiffness of the roof elements...