2019 - Publications Repository - Gdańsk University of Technology

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Publications from the year 2019

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Structure and the space vector modulation for a medium-voltage power-electronic-transformer based on two seven-level cascade H-bridge inverters
- Arkadiusz Lewicki
- Marcin Morawiec
2019 Full text IET Electric Power Applications
This study presents the structure and the space vector pulse-width modulation (SVPWM) for power electronic transformer (PET) based on two seven-level cascade H-bridge (CHB) inverters. The DC links of CHB inverters are coupled with nine dual-active bridge (DAB) converters with medium-frequency transformers. The DC-link voltages are equalised with two methods – through the control of DAB voltages and through the modulation strategy applied to both CHB inverters. In the proposed SVPWM, the influence of vector sequences on predicted DC-link voltages is analysed, and the optimum vector sequence is selected to equalise them. Regardless of this, the proposed SVPWM strategy enables the proper generation of output voltage vector also in the case of DC-link voltage imbalance – the calculation of the space-vector area takes into consideration the inequality of the DC-link voltages and its influence on the lengths and positions of active vectors. To simplify the modulation algorithm, the multilevel CHB inverter is considered as a set of three-level inverters connected in series. Each of them is controlled using the same SVPWM algorithm. The proposed modulation method reuses the H-bridges with zero duty cycles determined in the initial stages of the output voltage generation process. This enables the optimal management of the DC-link voltage distribution. The experimental research was carried out on a 600 kW/3.3 kV PET. The results are presented in this study.
Structure, luminescent properties and FDTD simulation of TeO2-BaO-Bi2O3-Ag:Ln3+ glass-ceramics system
- Tomasz Lewandowski
- Michalina Walas
- Anna Synak
- Paweł Syty
- Józef Eugeniusz Sienkiewicz
- Robert Kozioł
- Marcin Stanisław Łapiński
- Wojciech Sadowski
- Barbara Kościelska
2019 JOURNAL OF LUMINESCENCE
TeO2-BaO-Bi2O3-Ag glass systems (TBB) co-doped with terbium and europium ions have been successfully synthesized through conventional melt-quenching technique. Heat treatment procedure at 350 °C has been conducted in order to synthesize silver nanoparticles embedded in TBB glass matrix. Structural measurements involved XRD studies that revealed no crystallization of glass structure after heat treatment at elevated temperatures. TEM measurements revealed successful silver nanoparticles synthesis after annealing for 24 h. Mean size of nanoparticles was determined and equaled approximately 50 nm for exemplary heat treated sample. UVVIS study shown characteristic features of terbium and europium ions as well as LSPR band at approximately 550 nm. Photoluminescence measurements presented the possibility of simultaneous excitation of Eu3+ and Tb3+ with single wavelength. Moreover, possible energy transfer between Tb3+ and Eu3+ is discussed. Lifetimes of europium and terbium excited states have been measured. Shift of the emission colour from red to yellowish white has been observed when europium to terbium ratio was being changed. Thus, synthesized samples exhibited very good colour tunability induced by the change of composition. Also, the finite-difference time domain (FDTD) method has been applied to simulate electromagnetic field propagation through the selected sample.
Student competitions as a socio-spatial tool for planning urban structures
- Izabela Burda
- Małgorzata Dymnicka
2019 Full text World Transactions on Engineering and Technology Education
The aim of the article is to show the interdependencies between theory and practice based on the example of the student competitions at the Faculty of Architecture at the Gdańsk University of Technology. These competitions, on the one hand, broaden the spectrum of issues related to design and, on the other hand, contribute to the better recognition of problems related to tasks to be solved. Both the teaching and applicational aspects of the competition tasks remain in a significant relationship. For they favour the development of the city in the direction of the desired spatial, social, cultural, and natural cohesion. The main goal of the article is to attempt to show the relations between the natural and urban environment, which are particularly pronounced in the competition formula, open to a new look at the city and space.
Studies on the Combined Impact of Starch Source and Multiple Processing on Selected Properties of Thermoplastic Starch/Ethylene-Vinyl Acetate Blends
- Aleksander Hejna
- Joanna Lenża
- Krzysztof Formela
- Jerzy Korol
2019 Full text JOURNAL OF POLYMERS AND THE ENVIRONMENT
Thermoplastic starch (TPS)/ethylene vinyl acetate (EVA) blends compatibilized with polyethylene-graft-maleic anhydride (PE-g-MA) were prepared from various native starches (potato, maize and waxy maize) and subjected to multiple extrusion cycles. Source of starch has significant impact on its composition, hence properties of obtained TPS and their blends with EVA. Higher content of amylopectin in waxy maize starch, comparing to other types, enhanced the mechanical performance and increased tensile strength and elastic modulus even by 41 and 71%, respectively. Such effect was related to the branching of amylopectin and was confirmed by SEM analysis of fracture areas, which showed more ductile behavior for blends with higher content of amylose. Multiple processing had beneficial impact on the performance of blends, due to the increasing compatibility and more homogenous structure after additional processing time. FTIR analysis indicated higher extent of compatibilization reaction, which, together with finer morphology, resulted in the enhancement of mechanical performance. Such effect is very beneficial from application point of view, because materials can be reprocessed without the loss of properties.
Studies on the utilization of post-distillation liquid from Solvay process to carbon dioxide capture and storage
- Natalia Czaplicka
- Donata Konopacka-Łyskawa
2019 Full text SN Applied Sciences
In this work, a method of precipitated calcium carbonate production from the post-distillation liquid created in the Solvay process and waste carbon dioxide was proposed and investigated. Precipitation was carried out in a model solution of calcium chloride containing ammonia at various molar ratios in relation to Ca2+ ions, while gaseous carbon dioxide was supplied to the reactor as a pure gas or as a mixture with air. It was assumed that the reaction was completed when the pH of the reaction mixture reached the value of 7. To characterize precipitated calcium carbonate particles, its size and crystalline form were determined. It was possible to utilize above 80% of calcium ions from a model post-distillation liquid and above 80% of carbon dioxide from a mixed air-CO2 gas stream using the one-stage precipitation process since the conditions of precipitation were controlled. Calcium carbonate in vaterite form produced in this process can be also a valuable product.
Study of Aliphatic Polyurethanes by the Low-Field 1H NMR Relaxometry Method with the Inversion of the Integral Transformation
- Justyna Kucińska-Lipka
- Nikolay Sinyavsky
- I Mershiev
- G Kupriyanova
- Józef Haponiuk
2019 Full text APPLIED MAGNETIC RESONANCE
In this paper, the distributions of the 1H nuclear magnetic resonance (NMR) spin–lattice and spin–spin relaxation times are used to characterize the mobility of different sections of macromolecules of aliphatic polyurethanes and the cross-linking density of polymer chains. The NMR relaxometry method with inversion of integral transformation is applied to study the effect of poly (ethylene glycol) and glycerol phosphate calcium on the polymer dynamics.
Study of pH and temperature effect on lipophilicity of catechol-containing antioxidants by reversed phase liquid chromatography
- Claver Numviyimana
- Tomasz Chmiel
- Agata Kot-Wasik
- Jacek Namieśnik
2019 Full text MICROCHEMICAL JOURNAL
Lipophilicity of selected antioxidant phytochemicals, including flavonoids, phenolic acids and xanthonoids, was determined by reversed phase high performance liquid chromatography with UV detection (RP-HPLC-UV). The analyses run at different temperature and pH conditions in isocratic mode suggested that lipophilicity as distribution coefficient (logD) between aqueous and organic phase decreases with increasing temperature. For all studied compounds, logD changes slightly at lower pH and much decreases at a given pH range corresponding to the strongest dissociation by which dissociation constant (pKa) was estimated experimentally as well as their bioavailability in gastrointestinal pH conditions were predicted. Thermodynamic parameters demonstrated the increase in energy of transfer from the aqueous to the organic phase at higher pH thus decrease in lipophilicity. Experimental models of pH and temperature effect obtained by multiple regression underlined their significant impact (p < 0.05) on lipophilicity. The provided lipophilicity profiles and pKa data are useful descriptors to assess the affinity of the studied compounds for biological membranes, enzymes, carriers and target sites. Furthermore, the obtained result may be useful in the design of functional and medical foods, especially in order to increase the bioavailability of bioactive constituents, such as phenolic compounds, based on their lipophilic and acid-base character.
Study of the effect of adiabatic heating on the operation of the electrodynamic actuator
- Piotr Jankowski
- Mirosław Wołoszyn
2019 INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS
Electrodynamic actuators are used in hybrid switching systems where a very quick contact separation as well as operation repeatability and long-term reliability are required. The article presents selected results of thermal studies in the electrodynamic drive system. Study was carried out on the basis of the 3D electromagneto-thermal model implemented in the Ansys_Maxwell environment. The present model allows to determine the critical parameters related to the heating and to guarantee the correct and repeatable operation of the actuator.
Study on Combined Optical and Electrochemical Analysis Using Indium-tin-oxide-coated Optical Fiber Sensor
- Mateusz Śmietana
- Paweł Niedziałkowski
- Wioleta Białobrzeska
- Dariusz Burnat
- Petr Sezemsky
- Marcin Koba
- Vitezslav Stranak
- Katarzyna Siuzdak
- Tadeusz Ossowski
- Robert Bogdanowicz
2019 ELECTROANALYSIS
The growing needs for fast and reliable sensing devices stimulate development of new technological solutions. In this work a new multi-domain sensing method is demonstrated where optical sensing device has been applied to enhance amount of data received during electrochemical analysis. Thin, optically transparent, high-refractive-index, and electrically conductive indium tin oxide (ITO) film was deposited using magnetron sputtering on the surface of the long-period gratings (LPG) induced in optical fiber. ITO serves as working electrode in electrochemical setup and as a coating that enhances sensitivity of a LPG to changes of external refractive index. All the measurements were conducted in a combined optical and electrochemical setup. Obtained results show capability of this approach for optical monitoring of both electrochemical processes and changes in optical properties at the ITO surface. The optical response of the sensor was strongly dependent on the voltage applied to the ITO-LPG working electrode and on composition of the electrolyte. Changes observed in optical spectra may be attributed to the alterations in optical properties of both ITO layer (refractive index changes) and electrolyte in the vicinity of electrode (double layer formation). The developed structures can be further used as a fiber-based sensors and biosensors with integrated opto-electrochemical readout.
Study on population dynamics for triple-linked food chain using a simulation-based approach
- Kristiyan Balabanov
- Tymoteusz Cejrowski
- Doina Logofătu
- Costin Bădică
2019 Full text Evolving Systems
The procedures based on simulation have become a feasible testing method that does not require investing valuable resources to create a concrete prototype, especially with the increasing computational power of computers. Thus, design changes can be adopted and design errors can be fixed before it is too late. Simulation turns to be a cheap, safe and often more acceptable from an ethical perspective. In our work we summarize the results from the analysis with the help of a computational simulation of an elementary, yet analytically intractable problem scenario from the field of ecology. Our main goal is to confirm that even with a seemingly simple agent-based model and simulation, one could obtain plausible results regarding a system's real life behavior. As a last point, we propose an efficient alternative for analysis, rather than the expensive simulation process.
Study on the Influence of an Axial Distance Between Rotors on a Performance of a Small Counter-Rotating Wind Turbine
- Michał Pacholczyk
- Krzysztof Blecharz
- Dariusz Karkosiński
2019 Full text
In this paper, results of the investigation on the performance of a small counter-rotating wind turbinehas been presented. Computational Fluid Dynamics methodshave been used forwind turbine simulations. Rotors representation were introduced into computational domain by means of Actuator Line Model. Influence of an axial distance of CRWTrotorshas been investigated. In all studied configurations rotors were counter-rotating with exactly the same rotational speed. Results of a study revealed noticeable increase in power coefficient for optimal configuration. Dynamic interactionbetween rotors has been investigated exposing significant interference in both torque and power in part of considered cases. Reasonable rotors distances, as well as rotors placements on tower’s sides have been proposed. Used calculation method has been foundto be appropriate for counter-rotating wind turbinesimulation.
Style Transfer for Detecting Vehicles with Thermal Camera
- Sebastian Cygert
- Andrzej Czyżewski
2019
In this work we focus on nighttime vehicle detection for intelligent traffic monitoring from the thermal camera. To train a Convolutional Neural Network (CNN) detector we create a stylized version of COCO (Common Objects in Context) dataset using Style Transfer technique that imitates images obtained from thermal cameras. This new dataset is further used for fine-tuning of the model and as a result detection accuracy on images from thermal cameras has significantly improved. As a side effect, we noticed that Style Transfer can be also used to improve detection accuracy from standard RGB camera, which has potential for various applications.
Subharmonic solutions for a class of Lagrangian systems
- Anouar Bahrouni
- Marek Izydorek
- Joanna Janczewska
2019 Full text Discrete and Continuous Dynamical Systems-Series S
We prove that second order Hamiltonian systems with a potential of class C1, periodic in time and superquadratic at infinity with respect to the space variable have subharmonic solutions. Our intention is to generalise a result on subharmonics for Hamiltonian systems with a potential satisfying the global Ambrosetti-Rabinowitz condition from [P. H. Rabinowitz, Proc. Roy. Soc. Edinburgh Sect. A, 114 (1990), 33-38]. Indeed, we weaken the latter condition in a neighbourhood of the origin. We will also discuss when subharmonics pass to a nontrivial homoclinic orbit.
Subjective tests for gathering knowledge for applying color grading to video clips automatically
- Dawid Weber
- Bożena Kostek
2019 Full text
The analysis of film music concerning caused emotions may allow for a more accurate adaptation of the color of the film in the context of color grading. Therefore, this paper aims to gather knowledge on the correlation between the applied color palette to a video clip, music associated with a particular shot, and emotions evoked. For that purpose, subjective tests are prepared in which several video clips are presented with or without the accompanying music along with several models to describe emotions. The test is composed of three stages. First, video shots are presented: the role of the viewer is to assign the associated emotion on graphs representing the emotion model (Hevner’s, Thayer’s, Plutchik’s). The first part of the test is organized to check which of the emotion models is the easiest to associate the adapted color grading with emotion. Then, the test is repeated with the chosen psychological model on new video shots. The final phase consists of testing the same video shots but with accompanying music. In the paper, the meaning of the color in the film is explained based on the psychology of the color in film production. To analyze the sound path of the film, both low- and high-level parameters are given. Also, objective color measures corresponding to the tested film video shot are recalled. Assumptions for detecting emotions in the video shots to apply color grading automatically are also depicted.
Subjective tests for gathering konwledge for applaying color grading to video clips automatically
- Dawid Weber
- Bożena Kostek
2019
The analysis of film music concerning caused emotions may allow for a more accurate adaptation of the color of the film in the context of color grading. Therefore, this paper aims to gather knowledge on the correlation between the applied color palette to a video clip, music associated with a particular shot,and emotions evoked. For that purpose, subjective tests are prepared in which several video clips are presented with or without the accompanying music along with several models to describe emotions. The test is composed of three stages. First, video shots are presented: the role of the viewer isto assign the associated emotion on graphs representing the emotion model (Hevner’s, Thayer’s, Plutchik’s). Thefirst part of the testis organized to checkwhich of the emotion models is the easiest to associate the adapted color grading with emotion. Then, the test is repeated with the chosen psychological model on new video shots. The final phase consists of testing the same video shots but with accompanying music. In the paper, the meaning of the color in the film is explained based on the psychology of the color in film production. To analyze the sound path of the film, both low-and high-level parameters are given.Also, objective color measures corresponding to the tested film video shot are recalled. Assumptions for detecting emotions in the video shots to apply color grading automatically are also depicted.
Substancje groźne, niebezpieczne i pożyteczne.Tom 1: Pierwiastki i związki nieorganiczne
- Aleksander Kołodziejczyk
2019
Ludzie od początku swojego istnienia byli narażeni na działanie szkodliwych substancji chemicznych. Pierwotnie były to groźne dla życia opary wulkaniczne, toksyczne minerały – takie, jak arszenik, rudy ołowiu czy rtęci, szkodliwe metabolity wtórne (toksyny) wytwarzane przez mikroorganizmy, rośliny i zwierzęta, a także produkty spalania substancji organicznych, w tym dymy z palących się lasów czy stepów, zawierające czad, dioksyny, policykliczne węglowodory aromatyczne czy urusziole (alkilokatechole, alergeny trującego dębu). Pula tych niebezpiecznych i groźnych dla życia substancji była w zasadzie niezmienna na przestrzeni wielu tysiącleci. Z czasem jednak ludzie nauczyli się izolować i zatężać substancje naturalne, a także je przetwarzać, w związku z czym pojawiało się coraz więcej, coraz groźniejszych toksyn. Celem tej książki jest nie tylko omówienie niebezpiecznych związków i zwrócenie uwagi na zagrożenia, jakie stanowią dla organizmów żywych, przede wszystkim dla ludzi. Autorowi zależało również na pokazaniu, jak z ich powodu dochodziło do nieszczęśliwych wypadków i zwróceniu uwagi na długotrwałe, podejmowane na przestrzeni wieków wysiłki, zmierzające do wyeliminowania przyczyn wielu nieszczęść.
Sulfate‐reducing bacteria‐assisted hydrogen‐induced stress cracking of 2205 duplex stainless steels
- Jerzy Łabanowski
- Tomasz Rzychoń
- Wojciech Simka
- Joanna Michalska
2019 MATERIALS AND CORROSION-WERKSTOFFE UND KORROSION
The paper presents the results of a laboratory investigation of the microbiologically assisted hydrogen‐induced stress cracking (HISC) of 2,205 duplex stainless steel (DSS). The testing of susceptibility toward HISC was performed with two different methods. Precharged in sulfate‐reducing bacteria (SRB), inoculated medium samples were subjected to slow strain‐rate testing in artificial seawater. In situ constant load tests were performed directly in SRB‐inoculated medium under hydrogen charging at 70% of the ultimate tensile strength. Samples tested in the biotic (SRB) conditions showed a considerable loss of ductility as compared to those tested in sterile conditions. Quantitative characteristics of fracture surfaces indicated increased susceptibility to HISC of biotic samples, therefore, suggesting a role of SRB in promoting hydrogen damage of DSS.
Superconductivity in the intermetallic compound Zr5Al4
- Zuzanna Sobczak
- Michał Winiarski
- Weiwei Xie
- R.j. Cava
- Tomasz Klimczuk
2019 Full text EPL-EUROPHYS LETT
Polycrystalline Zr5Al4 was synthesized using the arc-melting method. Powder X-ray diffraction confirms the previously reported crystal structure of the Ti5Ga4-type P63/mcm with lattice parameters: a = 8.4312(6) A , and c = 5.7752(8) A . Electrical resistivity and low-temperature magnetic susceptibility measurements indicate that Zr5Al4 exhibits superconducting behavior below 2 K. The normalized heat capacity jump at Tc= 1.82 K , deltaC/gammaTc = 1.50 , confirms the bulk superconductivity. The Sommerfeld coefficient gamma = 28.5 mJmol^-1K^-2 and the Debye temperature Theta_D= 320 K were obtained by fitting the low-temperature heat capacity data. The electron-phonon coupling strength lambda_(el-ph) = 0.49 and estimated upper critical field mi0Hc2(0) = 1.09 T (dirty limit) suggest that Zr5Al4 is a weakly coupled type-II superconductor. First-principles calculations show the presence of a van Hove singularity near the Fermi energy.
Supporting Cybersecurity Compliance Assessment of Industrial Automation and Control System Components
- Janusz Górski
- Andrzej Wardziński
2019 Full text
The chapter presents a case study demonstrating how security requirements of an Industrial Automation and Control System (IACS) component can be represented in a form of Protection Profile that is based on IEC 62443 standards and how compliance assessment of such component can be supported by explicitly representing a conformity argument in a form based on the OMG SACM meta-model. It is also demonstrated how an advanced argument assessment mechanism based on Dempster-Shafer belief function theory can be used to support assessors while analyzing and assessing the conformity argument related to an IACS com-ponent. These demonstrations use a NOR-STA tool for representing, managing and assessment of evidence-based arguments, which have been developed in our research group.
Surface active fatty acid ILs: Influence of the hydrophobic tail and/or theimidazolium hydroxyl functionalization on aggregates formation
- Andrea Mezzetta
- Justyna Łuczak
- Julia Woch
- Cinzia Chiappe
- Janusz Nowicki
- Lorenzo Guazzelli
2019 JOURNAL OF MOLECULAR LIQUIDS
Nine structurally-related fatty acid ionic liquids have been prepared and their thermal behavior as well as their ability to self-assemble in water has been investigated. The thermal properties were studied by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC), while the aggregation behavior was analyzed by tensiometry, isothermal titration calorimetry (ITC), conductometry, dynamic light scattering (DLS), and electrophoretic light scattering (ELS). Structural variations concerned both the imidazolium cation (presence or not of hydroxyl groups) and the anion (length of the fatty acid), and affected in different ways the ILs' properties. With regards to the thermal stability, the presence of the hydroxyl group on the cation had a beneficial effect on stability regardless of the anion's length. This latter played instead a major role in allowing the solubility of the ILs in water (C18-stearate ILs were not soluble in water) and in determining the critical micelle concentration (CMC) values, as the reduction of the anion length in moving from C16-palmitate to C14-myristate anions disfavors aggregates formation. Several other parameters characterizing the adsorption of fatty acid ILs at the air/water interface, some thermodynamic parameters of the aggregation process as well as size distribution and stability of the aggregates were also determined.