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Gdańsk University of Technology

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Publications from the year 2020

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  • Fast-response optoelectronic detection of explosives’ residues from the nitroaromatic compounds detonation: field studies approach
    • Jacek Wojtas
    • Robert Bogdanowicz
    • Agata Kamieńska-Duda
    • Beata Pietrzyk
    • Michał Sobaszek
    • Piotr Prasuła
    • Anna Dettlaff
    • Krzystof Achtenberg
    2020 Full text MEASUREMENT

    We are presenting an application of optoelectronic nitrogen dioxide (NO2) analyzer based on cavity enhanced absorption spectroscopy in the detection of traces of explosives after detonation. It has been shown that the analyzer using blue-violet laser is able to detect explosive residues after the detonation of various amounts of nitroaromatic compounds (75g-1kg) with higher efficiency than the HPLC soil sample testing equipment, which is the common standard in the analysis of explosives. Field studies have shown that it provided quick results, the amplitudes of which were about 8 dB despite the fact that NO2 in the air was 3 orders of magnitude smaller than explosives found in soil. The NO2 concentration after an explosion of different explosives at the distance of up to 20 m from the crater was 21-137 ppb, which was also dependent on the time between the explosion and the measurement, temperature and humidity of the atmospheric air and wind speed.

  • Fault Diagnostics in PEMFC Stacks by Evaluation of Local Performance and Cell Impedance Analysis
    • Jens Mitzel
    • J. Sanchez‐Monreal
    • D. Garcia‐Sanchez
    • P. Gazdzicki
    • M. Schulze
    • F. Häußler
    • Jurgen Hunger
    • G. Schlumberger
    • Ewa Janicka
    • Michał Mielniczek
    • Łukasz Gaweł
    2020 FUEL CELLS

    Starvation, flooding, and dry‐out phenomena occur in polymer electrolyte membrane fuel cells (PEMFCs), due to heterogeneous local conditions, material inhomogeneity, and uneven flow distribution across the single cell active area and in between the individual cells. The impact of the load level and air feed conditions on the performance was identified for individual single cells within a 10‐cell stack. Analysis of the current density distribution across the active area at the cell level was correlated with electrochemical impedance spectroscopy to enable operando fault diagnostic without any impact of the applied analytical tools on the single cell behavior. Moreover, the combination of both technologies allows in‐depth analysis of fault mechanisms in fuel cell single cells with improved sensitivity. Current density distribution and the quantitative assessment of the performance homogeneity demonstrated high sensitivity to small humidity changes and allow the detection of critical events, such as dry‐out in single cells. Impedance analysis is more sensitive regarding polarization and diffusion limitations and allows detection of cell flooding. The combination of both techniques is required for reliable identification of air starvation faults.

  • Fault Loop Impedance Measurement in Circuits Fed by UPS and Principle of Safety Protection
    • Jacek Katarzyński
    • Marek Olesz
    2020 Full text Sustainability

    This paper indicates a significant problem of uncertainty of fault loop impedance (FLI) measurement in circuits powered from uninterruptible power supply (UPS) (double-conversion AC-DC-AC). The correctly determined value of this impedance, related to the short-circuit current disconnection time and to the reference value, is one of the most important elements that determines the approval of an electrical installation and its receivers for operation. To define the principles of FLI measurement, several hundred measurements of the short-circuit loop impedance in the circuits fed by the UPS, in various UPS operation modes and with various FLI instruments, were made, which allowed for the definition of measurement rules that reduce the error in assessing the effectiveness of protection against electric shock by automatic disconnection of supply. Based on the analysis of voltage and current waveforms recorded during the real short-circuit tests in the circuit fed by the UPS, a proprietary algorithm for determining the short-circuit loop impedance has been proposed.

  • Faults and Fault Detection Methods in Electric Drives
    • Patrick Strankowski
    • Jarosław Guziński
    2020

    The chapter presents a review of faults and fault detection methods in electric drives. Typical faults are presented that arises for the induction motor, which is valued in the industry for its robust construction and cost-effective production. Moreover, a summary is presented of detectable faults in conjunction with the required physical information that allow a detection of specific faults. In order to address faults of a complete drive system, characteristic failures of the mechanical part of the drive system are as well presented. Furthermore, the physical forces, which arise during specific faults (i.e. centrifugal, kinematic) are presented along with dominant harmonics in the frequency spectrum. These dominant harmonics are especially important for the determination of a malfunction of the drive. The detection of the particular could be performed with signal processing methods which are tabular summarized for introduction purposes. In order to cover a further industry interest, a cost-effectiveness relation is presented, which describes whether a diagnostic system is appreciative or not. Moreover, most important international standards regarding the safety, health for human and machinery are summarized that are required to be fulfilled in every industrial application. The next subsection is dedicated to the presentation of fault detection methods that include a review of conventional methods for monitoring the conditions of the electric machine. That includes the monitoring of variables that are based on electrical, chemical, mechanical and thermal changes in the induction motor. The last subsection considers the fault detection methods, which are based on utilization of mathematical models. In this kind of fault detection, the model description is utilized to identify changes in the drive system, which then can be used for a potential fault identification procedure. Such mathematical constructs are mainly based on observer, Kalman filters or neural networks. The chapter is concluded with a short summary of the presented sections.

  • Feasibility Study GaN Transistors Application in the Novel Split-Coils Inductive Power Transfer System with T-Type Inverter
    • Viktor Shevchenko
    • Bohdan Pakhaliuk
    • Oleksandr Husev
    • Oleksandr Veligorskyi
    • Deniss Stepins
    • Ryszard Strzelecki
    2020 Full text ENERGIES

    A promising solution for inductive power transfer and wireless charging is presented on the basis of a single-phase three-level T-type Neutral Point Clamped GaN-based inverter with two coupled transmitting coils. The article focuses on the feasibility study of GaN transistor application in the wireless power transfer system based on the T-type inverter on the primary side. An analysis of power losses in the main components of the system is performed: semiconductors and magnetic elements. System modeling was performed using Power Electronics Simulation Software (PSIM). It is shown that the main losses of the system are static losses in the filter inductor and rectifier diodes on the secondary side, while GaN transistors can be successfully used for the wireless power transfer system. The main features of the Printed Circuit Board (PCB) design of GaN transistors are considered in advance

  • Feedback Control of Multiphase Induction Machines with Backstepping Technique
    • Marcin Morawiec
    • Patrick Strankowski
    • Arkadiusz Lewicki
    • Jarosław Guziński
    • Filip Wilczyński
    2020 IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS

    The paper presents the control possibility of five phase induction machines. In the proposed solution the machine model vector form is not transformed to the (dq)-coordinate system, that is connected to rotor flux vector, but utilizes the stationary system ( αβ ). Moreover, the nonlinear model linearization is based on demonstrated nonlinear variables transformation for i-orthogonal ( αβ )(n) planes. By introducing the backstepping approach, the independent stabilization of electromagnetic torque and rotor flux in each plane is obtained. A practical stability analysis of the proposed controller for a multi-phase machine is illustrated as well. Finally, experimental test results are demonstrated for a specific speed sensorless five phase induction motor test setup

  • FEM-based wave propagation modelling for SHM: Certain numerical issues in 1D structures
    • Magdalena Palacz
    • Arkadiusz Żak
    • Marek Krawczuk
    2020 Full text Materials

    The numerical modelling of structural elements is an important aspect of modern diagnostic systems. However, the process of numerical implementation requires advanced levels of consideration of multiple aspects. Important issues of that process are the positive and negative aspects of solution applied methods. Therefore the aim of this article is to familiarise the reader with the most important aspects related to the process of numerical modelling of one-dimensional problems related to the phenomena of the propagation of elastic waves and their application for damage detection purposes.

  • Filozofować z głębi człowieczeństwa. O fenomenologii Andrzeja Półtawskiego.
    • Andrzej Lisak
    2020 Kwartalnik Filozoficzny

    Dokonując krytyki tradycji nowożytnego empiryzmu i kartezjańskiego dualizmu Półtawski tworzy realistyczną i dynamiczną interpretację bytu ludzkiego. Przeżywanie, odczuwanie zmysłowe nie jest poślednią odmianą poznania jak i operacją dostarczania jedynie elementów, budulca poznaniu, ale odrębnym sposobem bycia w świecie, jest symbiotycznym kontaktem z otoczeniem, formą życia. Zrywa on radykalnie z tradycją brentanowsko-husserlowską traktowania świadomości jako zbioru aktów, a nie zbioru treści. Przeciwstawia temu model fenomenologii noematycznej. Nie możemy zobaczyć jak powstają noematy (treści świadomości), bo nie jest to robota samej świadomości, ani w sferze zmysłowego przeżywania, gdzie świat jest nam już pierwotnie dany jakby „od dołu” ani na wyższym poziomie świadomego funkcjonowania w świecie, gdzie świat (jako model świata), jest już nam znowuż dany, jakby „od góry”. Model świata tkwi nie w świadomości aktualnie obecnej, ale jakby za jej kulisami, aby umożliwić przytomne bycie człowieka w świecie. Ontologia wypracowana na gruncie najprostszego sposobu bycia człowieka jako tylko postrzegającego nie jest w stanie pojąć i zrozumieć realności świata, a zwłaszcza realności wartości. Oddać sprawiedliwość roli wartości może tylko całościowa i dynamiczna koncepcja człowieka, której wizji Półtawski szuka w konfrontacji z poglądami Ingardena , Strassera i Wojtyły.

  • Finiper
    • Luciano Segreto
    2020

    .

  • Finite Element Approaches to Model Electromechanical, Periodic Beams
    • Wiktor Waszkowiak
    • Marek Krawczuk
    • Magdalena Palacz
    2020 Full text Applied Sciences-Basel

    Periodic structures have some interesting properties, of which the most evident is the presence of band gaps in their frequency spectra. Nowadays, modern technology allows to design dedicated structures of specific features. From the literature arises that it is possible to construct active periodic structures of desired dynamic properties. It can be considered that this may extend the scope of application of such structures. Therefore, numerical research on a beam element built of periodically arranged elementary cells, with active piezoelectric elements, has been performed. The control of parameters of this structure enables one for active damping of vibrations in a specific band in the beam spectrum. For this analysis the authors propose numerical models based on the finite element method (FEM) and the spectral finite element methods defined in the frequency domain (FDSFEM) and the time domain (TDSFEM).

  • Finite element modelling of a historic church structure in the context of a masonry damage analysis
    • Marcin Kujawa
    • Izabela Lubowiecka
    • Czesław Szymczak
    2020 Full text ENGINEERING FAILURE ANALYSIS

    The paper includes a case study of modelling a real historic church using the finite element method (FEM) based on laser scans of its geometry. The main goal of the study was the analysis of the causes of cracking and crushing of masonry walls. An FEM model of the structure has been defined in ABAQUS. A non-linear dynamic explicit analysis with material model including damage plasticity has been performed. A homogenization procedure has been applied to obtain the material parameters used in the modelling of masonry. In the numerical analysis, the interactions between the church structure, the foundations and the ground were taken into account. The obtained results match well with the damaged area of the entire structure from the in-situ survey, and it should be highlighted that the proposed FEM model allows for a rather precise identification of the causes and effects of cracking walls in a qualitative sense. Also a brief research summary is presented.

  • Fish gelatin films containing aqueous extracts from phenolic-rich fruit pomace
    • Hanna Staroszczyk
    • Barbara Kusznierewicz
    • Edyta Malinowska-Pańczyk
    • Izabela Sinkiewicz
    • Karolina Gottfried
    • Ilona Kołodziejska
    2020 Full text LWT-FOOD SCIENCE AND TECHNOLOGY

    The aim of the work was to study the feasibility of using aqueous extracts from rowanberry, blue-berried honeysuckle, and chokeberry pomace for the formulation of fish gelatin films with antioxidant and antimicrobial activity as well as improved mechanical and water barrier properties. The predominant phenolic components in rowanberry and chokeberry extracts were hydroxycinnamates, and in blue-berried honeysuckle extract antho cyanins. Although the gelatin film itself showed antioxidative activity, addition of blue-berried honeysuckle extract increased it 3-fold. Unlike the films containing 1.2 mL of extract, the films with increased extract volume possessed strong antimicrobial properties against E. coli, P. fluorescens, S. aureus, L. innocua. Films plasticized with glycerol at 15 and 17.5% did not increase the mechanical strength in the presence of all extracts tested, but at 20%, a positive effect of each extract on mechanical strength was observed. None of the extracts affected the water barrier properties of the films.

  • Fixed Pattern Noise Reduction and Linearity Improvement in Time-Mode CMOS Image Sensors
    • Miron Kłosowski
    • Yichuang Sun
    2020 Full text SENSORS

    In the paper, a digital clock stopping technique for gain and offset correction in time-mode analog-to-digital converters (ADCs) has been proposed. The technique is dedicated to imagers with massively parallel image acquisition working in the time mode where compensation of dark signal non-uniformity (DSNU) as well as photo-response non-uniformity (PRNU) is critical. Fixed pattern noise (FPN) reduction has been experimentally validated using 128-pixel CMOS imager. The reduction of the PRNU to about 0.5 LSB has been achieved. Linearity improvement technique has also been proposed, which allows for integral nonlinearity (INL) reduction to about 0.5 LSB. Measurements confirm the proposed approach.

  • Flexoelectricity and apparent piezoelectricity of a pantographic micro-bar
    • Victor Eremeev
    • Jean-François Ganghoffer
    • Violetta Konopińska-Zmysłowska
    • Nikolay Uglov
    2020 Full text INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE

    We discuss a homogenized model of a pantographic bar considering flexoelectricity. A pantographic bar consists of relatively stiff small bars connected by small soft flexoelectric pivots. As a result, an elongation of the bar relates almost to the torsion of pivots. Taking into account their flexoelectric properties we find the corresponding electric polarization. As a results, the homogenized pantographic bar demonstrates piezoelectric properties inherited from the flexoelectric properties of pivots. The effective stiffness properties of the homogenized bars are determined by the geometry of the structural elements and shear stiffness whereas the piezoelectric properties follow from the flexoelectric moduli of the pivots.

  • Flexural behavior of composite structural insulated panels with magnesium oxide board facings
    • Łukasz Smakosz
    • Ireneusz Kreja
    • Zbigniew Pozorski
    2020 Full text Archives of Civil and Mechanical Engineering

    The current report is devoted to the flexural analysis of a composite structural insulated panel (CSIP) with magnesium oxide board facings and expanded polystyrene (EPS) core, that was recently introduced to the building industry. An advanced nonlinear FE model was created in the ABAQUS environment, able to simulate the CSIP’s flexural behavior in great detail. An original custom code procedure was developed, which allowed to include material bimodularity to significantly improve the accuracy of computational results and failure mode predictions. Material model parameters describing the nonlinear range were identified in a joint analysis of laboratory tests and their numerical simulations performed on CSIP beams of three different lengths subjected to three- and four-point bending. The model was validated by confronting computational results with experimental results for natural scale panels; a good correlation between the two results proved that the proposed model could effectively support the CSIP design process.

  • Flooding Extent Mapping for Synthetic Aperture Radar Time Series Using River Gauge Observations
    • Tomasz Berezowski
    • Tomasz Bieliński
    • Jakub Osowicki
    2020 Full text IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing

    The flooding extent area in a river valley is related to river gauge observations such as discharge and water elevations. The higher the water elevations, or discharge, the larger the flooding area. Flooding extent maps are often derived from synthetic aperture radar (SAR) images using thresholding methods. The thresholding methods vary in complexity and number of required parameters. We proposed a simple thresholding method that takes advantage of the correlation between the river gauge and the flooding area. To show the applicability of the method, we used a 2014–2018 time series of 161 Sentinel 1 SAR images acquired over a wetland floodplain located in Northeast Poland. We validated the method by extracting local water line elevations from a high-resolution digital elevation model for three river gauges, which resulted in a root-mean-square error of 0.16 m, a bias of 0.07 m, and a correlation of 0.86 for the best scenario. The scenario analysis showed that the most important factor affecting the method's accuracy was a proper delineation of the zone in which the flooding extent area was calculated. This was because other water sources, uncorrelated with river flow, were present in the floodplain as open water. Additionally, higher accuracy was obtained for the VV than VH polarization. The discharge can be used instead of water elevations as a river gauge variable, but this results in more bias in the water extent estimates.

  • Flow distribution and heat transfer in minigap and minichannel heat exchangers during flow boiling
    • Michał Klugmann
    • Paweł Dąbrowski
    • Dariusz Mikielewicz
    2020 Full text APPLIED THERMAL ENGINEERING

    The topic of boiling heat transfer in miniscale geometries has focused the ever increasing interest of researchers in recent years. However, most of the works are related to mini- and microchannels and much less to minigaps. Meanwhile, minigaps allow for more comprehensive experimental studies, i.e. flow visualisations due to the flat, two-dimensional configuration of the flow. The results of the experimental investigations of a model plate heat exchanger, composed of a single plate with a heat exchange surface of 0.1 m × 0.2 m, made of brass are presented. The working fluid is pure ethanol. Between the plate and the cover of the exchanger, 0.5 mm and 1.0 mm thick minigaps are arranged. The 0.5 mm minigap has been compared to an equivalent minichannel structure (a set of 50 parallel minichannels) with an equal cross-sectional area (rectangular 1 mm × 1 mm). An attempt to intensify the heat exchange by modifying the minigap wall was made. Two variants were tested to check the potential increase in the heat transfer coefficient and flow resistance. The section cover is transparent in order to simultaneously register the flow structures with the measurements. The heat is supplied using a water circuit, where the temperature and flow of the water can be regulated in a constant temperature water tank. The flow configuration of the exchanger is countercurrent, with the vertical flow of ethanol from the bottom to the top. The inlet and outlet manifolds are arranged as trapezoidal (Z-type design). The authors have analysed the efficiency of heat transport and pressure drop depending on the system operating parameters. The visualisations are thoroughly analysed to better understand the process. The main advantages of the presented work are a direct comparison of minigap and minichannel structures while standardising all other parameters; an interesting application of a simple, passive heat transfer intensification method which resulted in the unification of the velocity fields in the minigap and reduced maldistribution.

  • Fluctuation-Enhanced Sensing
    • Graziella Scandurra
    • Janusz Smulko
    • Laszlo B. Kish
    2020 Journal of Sensors

    Fluctuation-enhanced sensing (FES) is an exciting and relatively new research field that promises to extend the range of information that can be extracted from a single sensor. In FES, the stochastic fluctuations of the sensor signal, rather than its average value, are recorded and analyzed. Typical components of such fluctuations are due to interactions at the microscopic level. Proper statistical analysis provides optimum sensory information.

  • Fluctuation-Enhanced Sensing (FES): A Promising Sensing Technique
    • Graziella Scandurra
    • Janusz Smulko
    • Laszlo Kish
    2020 Full text Applied Sciences-Basel

    Fluctuation-enhanced sensing (FES) is a very powerful odor and gas sensing technique and as such it can play a fundamental role in the control of environments and, therefore, in the protection of health. For this reason, we conduct a comprehensive survey on the state-of-the-art of the FES technique, highlighting potentials and limits. Particular attention is paid to the dedicated instrumentation necessary for the application of the FES technique and also in this case limits and possible future developments are highlighted. In particular, we address resolution, measurement speed, reproducibility, memory, noise, and other problems such as the influence of humidity. A number of techniques and guidelines are proposed to overcome these problems. Circuit solutions are also discussed.

  • FLUID BED COATING OF MINITABLETS AND PELLETS WITH OPTIMIZATION OF THE PROCESS BASED ON TAGUCHI METHOD
    • Turk Magdalena
    • Bożenna Kawalec-Pietrenko
    • Małgorzata Sznitowska
    • Piotr Rybarczyk
    2020 Full text Acta Poloniae Pharmaceutica - Drug Research

    Small particles like pellets are coated in fluid bed systems. This method can be also feasible for minitablets but the selection of optimal process parameters is complicated. The aim of the research was to optimize the coating process for minitablets and to compare the conditions required for pellets. Minimum fluidization velocities (umf) for 2.0 and 2.5 mm minitablets and 0.7-0.8 mm or 1.0-1.25 mm pellets were determined experimentally. Additionally, the results were verified using the Ergun equation. The smallest relative differences between the calculated and experimental values of umf were obtained for P0.7 (4.6%), while the largest for MT2.5 (11.8%). To simplify optimization of the coating process, Design of Experiment (DoE) based on the Taguchi method was employed. Selection of the best process parameters was based on the film thickness measurements for minitablets, while the sieve analysis was used for pellets to detect agglomeration. The best combination of process parameters resulted in uniform film thickness in minitablets, with RSD less than 15%, and the pellets batch containing only 0.25% of bonded particles. It was found that the largest impact on the uniform film deposition on minitablets had a spraying pressure, responsible for the size of coating mixture droplets. In the case of pellets, the most critical was the inlet air temperature. The presented research demonstrated that it was possible to achieve the best parameters of the coating process for minitablets and pellets by combining calculations of minimum fluidization velocity and Design of Experiment based on the Taguchi method.