2019 - Publications Repository - Gdańsk University of Technology

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Publications from the year 2019

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Degree product formula in the case of a finite group action
- Piotr Bartłomiejczyk
- Bartosz Kamedulski
- Piotr Nowak-Przygodzki
2019 Full text New York Journal of Mathematics
Let V, W be finite dimensional orthogonal representations of a finite group G. The equivariant degree with values in the Burnside ring of G has been studied extensively by many authors. We present a short proof of the degree product formula for local equivariant maps on V and W.
Denitrifcation rate in the mainstream deammonification
- Anna Wilińska
- Krzysztof Czerwionka
2019 Full text World Scientific News
The conventional processes of biological nitrogen removal based on nitrification and denitrification does not fit properly into the concept of the circular economy. As the alternative one should consider the deammonification process, which is a combination of partial nitrification (nitritation) and Anammox processes. It consists of removing ammonium nitrogen from wastewater under anaerobic conditions by a group of autotrophic microorganisms. The result is a significant reduction in oxygen demand, while there is no a need for organic compounds that can be converted into biogas in digesters. The deammonification process can be successfully used to treat leachate from the sludge management of WWTP. Currently, research works focus on the use of this process for wastewater treatment in the mainstream of WWTP. This type of research, on a pilot scale, was also carried out at Gdańsk WWTPs. The aim of the presented research was the analysis of the possibility of a simultaneous removal of nitrates, generated during the mentioned deammonification process. The dissolved organic compounds present in the mechanically and chemically treated wastewater can be used in the denitrification process. The efficiency of the process has been determined by performing conventional denitrification rate tests (NUR). The average values of NUR 1 (2.75 mg NOx / gvss ∙ h) and NUR 2 (1.05 NOx / gvss ∙ h) were close to the values typical for mechanically treated municipal sewage. It has been shown that the denitrification process can cause an increase of total nitrogen removal efficiency in the process of deammonification of municipal wastewater. The amount of available organic compounds was sufficient to carry out the denitrification process of nitrates produced during the deammonification process.
Density, sound velocity, viscosity, and refractive index of new morpholinium ionic liquids with amino acid-based anions: Effect of temperature, alkyl chain length, and anion
- Łukasz Marcinkowski
- Emil Szepiński
- Maria Jolanta Milewska
- Adam Kloskowski
2019 JOURNAL OF MOLECULAR LIQUIDS
In this work, room temperature synthesis of twenty new ionic liquids (ILs) based on the N-alkyl-N-methylmorpholinium ([Mor1,R], R = 2, 3, 4, 6, 8) cation and N-acetyl-L-amino acid anions (L-alaninate, L-valinate, L-leucinate, L-isoleucinate) was described. The synthesized ILs were characterized by various spectroscopic techniques and high-resolution mass spectrometry. Furthermore, density (ρ), sound velocity (v), viscosity (η) and refractive index (nD) have been measured within the temperature range of T = (298.15 to 318.15) K and at 0.1 MPa pressure. The density, sound velocity and viscosity values were fitted to linear and Vogel–Tammann–Fulcher (VTF) equation. Moreover, on the basis of the refractive index values, molar refraction (Rm) and free volume (Vf) were calculated using the Lorentz–Lorenz equation. The thermodynamic properties such as thermal expansion coefficient (α) and isentropic compressibility (κS) were calculated using the experimental values of density and sound velocity. Finally, the obtained data were evaluated in order to determine the effect of such parameters as temperature, the nature of the anion and the length of the cation alkyl chain.
Deposition and Electrical and Structural Properties of La0.6Sr0.4CoO3 Thin Films for Application in High-Temperature Electrochemical Cells
- Bartosz Kamecki
- Jakub Karczewski
- Hamid Abdoli
- Ming Chen
- Grzegorz Jasiński
- Piotr Jasiński
- Sebastian Molin
2019 Full text JOURNAL OF ELECTRONIC MATERIALS
Low-temperature deposition of electroceramic thin films allows the construction of new devices and their integration with existing large-scale fabrication methods. Developing a suitable low-cost deposition method is important to further advance the development of microdevices. In this work, we deposited a 1-lm-thick La0.6Sr0.4CoO3d (LSC) perovskite with high electrical conductivity on sapphire substrates at 400C and analyzed its electrical, morphological and structural properties as a function of temperature in the range of 400– 1100C. The results show that spray pyrolysis can be used to deposit highquality reproducible layers with the desired chemical and phase composition. Upon heating to around 600C, the residual C–O and C=O species are removed, and the deposited layers crystallize and become conducting. The dependence of electrical conductivity versus processing temperature has a complex character—the maximum conductivity is found for layers processed at 800C. An analytical model of stress distribution was used to predict stress to which the bi-layer material would be exposed to while being cooled down from the annealing temperature to room temperature. The high electronic conductivity and high-quality microstructure of the LSC layers, which can be adjusted with the appropriate heat treatment procedure, make them suitable for applications in electrochemical devices applied in integrated energy modules, including electrodes or contacts.
Derecho Evolving from a Mesocyclone—A Study of 11 August 2017 Severe Weather Outbreak in Poland: Event Analysis and High-Resolution Simulation
- Mateusz Taszarek
- Natalia Piguj
- Juliusz Orlikowski
- Artur Surowiecki
- Szymon Walczakiewicz
- Wojciech Pilorz
- Krzysztof Piasecki
- Łukasz Pajurek
- Marek Półrolniczak
2019 Full text MONTHLY WEATHER REVIEW
This study documents atmospheric conditions, development, and evolution of a severe weather outbreak that occurred on 11 August 2017 in Poland. The emphasis is on analyzing system morphology and highlighting the importance of a mesovortex in producing the most significant wind damages. A derecho-producing mesoscale convective system (MCS) had a remarkable intensity and was one of the most impactful convective storms in the history of Poland. It destroyed and partially damaged 79 700 ha of forest (9.8 million m3 of wood), 6 people lost their lives, and 58 were injured. The MCS developed in an environment of high 0–3-km wind shear (20–25 m s−1), strong 0–3-km storm relative helicity (200–600 m2 s−2), moderate most-unstable convective available potential energy (1000–2500 J kg−1), and high precipitable water (40–46 mm). Within the support of a midtropospheric jet, the MCS moved northeast with a simultaneous northeastward inflow of warm and very moist air, which contributed to strong downdrafts. A mesocyclone embedded in the convective line induced the rear inflow jet (RIJ) to descend and develop a bow echo. In the mature stage, a supercell evolved into a bookend vortex and later into a mesoscale convective vortex. Swaths of the most significant wind damage followed the aforementioned vortex features. A high-resolution simulation performed with initial conditions derived from GFS and ECMWF global models predicted the possibility of a linear MCS with widespread damaging wind gusts and embedded supercells. Simulations highlighted the importance of cloud cover in the preconvective environment, which influenced the placement and propagation of the resulting MCS.
Derivation of motor mean phase currents in PMSM drives operating with low switching-to-fundamental frequency ratio
- Leszek Jarzębowicz
2019 Full text Power Electronics and Drives
Pulse width modulation (PWM) of inverter output voltage causes the waveforms of motor phase cur-rents to consist of distinctive ripples. In order to provide suitable feedback for the motor current con-trollers, the mean value must be extracted from the currents’ waveforms in every PWM cycle. A com-mon solution to derive the mean phase currents is to sample their value at the midpoint of a symmetrical PWM cycle. Using an assumption of linear current changes in steady PWM subintervals, this midpoint sample corresponds to the mean current in the PWM cycle. This way no hardware filtering or high-rate current sampling is required. Nevertheless, the as-sumption of linear current changes has been recently reported as over simplistic in permanent magnet syn-chronous motor (PMSM) drives operating with low switching-to-fundamental frequency ratio (SFFR). This, in turn, causes substantial errors in the repre-sentation of the mean phase currents by the midpoint sample. This paper proposes a solution for deriving mean phase currents in low SFFR PMSM drives, which does not rely on the linear current change as-sumption. The method is based on sampling the cur-rents at the start point of a PWM cycle and correct-ing the sampled value using a model-based formula that reproduces the current waveforms. Effective-ness of the method is verified by simulation for an exemplary setup of high-speed PMSM drive. The re-sults show that the proposed method decreases the error of determining the mean phase currents approx-imately 10 times when compared to the classical midpoint sampling technique.
Design and Experiments of a Piezoelectric Motor Using Three Rotating Mode Actuators
- Roland Ryndzionek
- Łukasz Sienkiewicz
- Michał Michna
- Filip Kutt
2019 Full text SENSORS
This paper represents a numerical and experimental investigation of the multicell piezoelectric motor. The proposed design consists of three individual cells that are integrated into the stator, double rotor, and a preload system combined into a symmetrical structure of the motor. Each of the cells is characterized by a traveling wave and rotating mode motor. A finite element numerical analysis is carried out to obtain optimal geometrical dimensions of the individual cell in terms of generated vibrations and resonant frequencies of the structure. The results of the numerical analysis are compared with analytical calculations based on the equivalent circuit theory. Experimental tests are also presented, including laser interferometry measurements of vibrations generated at the surface of the stator, impedance analysis, as well as measurements of mechanical characteristics of the complete motor. The final stage of the study concludes that the presented motor can provide relatively high torque compared with other traveling wave rotary motors.
Design and material selection for a patient transport device in field hospitals
- Magda Dziaduszewska
- Martyna Zimna
- Beata Świeczko-Żurek
2019 Full text Minerva Ortopedica E Traumatologica
ACKGROUND: A major cause of patient and hospital worker injuries occurs transferring patients between two planes. The main aim of this paper was to propose a design of patient’s lift and transfer apparatus for use in field hospitals. The assumption was to design lightweight, durable and ergonomic device using innovative material. The authors concentrated on partial elimination of manual lifting in order to device could work both in two situations: with or without electricity. The paper includes mechanical design, material selection and analytical calculation. METHODS: In order to carry out strength calculations, the shape and size of device was designed using AutoCAD. Based on a comparison of composite material properties, an epoxy-carbon laminate was selected. The strength calculations were performed in the following order: determination of elementary stresses, determination of the most dangerous cross-section, calculation of tensile strength, calculation of Young’s modulus, selection of channel dimensions, determination of material parameters (thickness, fiber mass), determination of substitute stresses. RESULTS: To design a lightweight, durable and ergonomic patient lift with lifting capacity of 150 kg an epoxy-carbon laminate composed of three layers was chosen. A profile in a C-shape and dimension of 138x90x14 mm has been designed. Patient lift includes an arm of 1.6 m height and 1m length of the horizontal beam. The designed transport mechanism uses rollers, a linear electric actuator and a crank with a worm gear. CONCLUSIONS: The designed device fulfil the most important criterion, which is to ensure the safety of patients and medical personnel. The height adjustment mechanism partially eliminates the manual transfer of patients and is adapted to the conditions existing in a field hospital.
Design and optimization of a novel compact broadband linearly/circularly polarized wide-slot antenna for WLAN and Wi-MAX applications
- Ullah Ubaid
- Sławomir Kozieł
2019 Full text RADIOENGINEERING
A novel topologically modified structure of a compact low profile wide-slot antenna for broadband applications is presented. The antenna comprises a modified E-shaped slot with unequal arm lengths in the ground plane, and a parasitic quasi-rectangular loop placed coplanar with the feedline. For exciting orthogonal modes with equal amplitude, a single-point feeding technique with an asymmetrical geometry of the coplanar waveguide is used to feed the antenna. A multi-stage EM-driven optimization is used to rigorously optimize all the parameters for best impedance bandwidth and axial ratio bandwidth. The total footprint of the antenna is only 0.71 λg^2 and a 41% impedance bandwidth along with 33% axial ratio bandwidth has been achieved which covers several WLAN and WiMAX bands.
Design Equation for Stirring Fluid by a Stream Pump in a Circulating Tank
- Jerzy Sawicki
- Paweł Wielgat
- Piotr Zima
2019 Full text Water
A circulating tank is a very useful theoretical scheme for many fluid-flow objects in several branches of engineering. The motion of the fluid in such objects can be induced in different ways. A stream pump provides an especially interesting possibility; however, the quantitative description of such devices shows some shortcomings. Such a device is analogous to a jet pump, thus has similar advantages (simplicity of construction, lack of movable elements, insensibility to pollutants) and disadvantages (low efficiency). On the one hand, from the technical viewpoint, one can make use of technical instructions presented in handbooks and offered by producers, and on the other hand by performing calculations using CFD tools. In this situation, it is self-evident that some intermediary method of design, i.e., formally simple, but physically convincing, would be welcome both by theoreticians and by engineers. Such a method is proposed in this paper and takes the form of an algebraic formula, combining the discharge of the stream pump and the discharge of the circulation induced by this stream. This expression, based on the balance between the power of the stream and the power of dissipation, has been experimentally verified with a positive result.
Design of control algorithms for mobile robots in an environment with static and dynamic obstacles
- Robert Piotrowski
- Bartosz Maciąg
- Wojciech Makohoń
- Krzysztof Milewski
2019 Full text Journal of Automation, Mobile Robotics and Intelligent Systems - JAMRIS
This article proposes the construction of autonomous mobile robots and designing of obstacle avoidance algorithms for them. Nowadays, mobile robots are gaining more and more popularity on the customer as well as industrial market, for example as automatic vacuum cleaners or lawnmowers. Obstacle avoidance algorithms play an important role in performance of this types of robots. The proposed algorithms were designed for builds with rather not expensive electronic components, especially sensors with limited precision and dynamics. The project began with the selection of needed parts and building materials as well as designing of the PCB and assembling the whole construction. The project included also designing and developing the software responsible for, among others, implementation of obstacle avoidance algorithms. After the project’s completion, a series of tests in a closed environment was conducted to verify the quality of vehicles’ performance. Results of tests were positive.
Design of dimensionally stable composites using efficient global optimization method
- Levent Aydin
- Olgun Aydin
- H Seçil Artem
- Ali Mert
2019 PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART L-JOURNAL OF MATERIALS-DESIGN AND APPLICATIONS
Dimensionally stable material design is an important issue for space structures such as space laser communication systems, telescopes, and satellites. Suitably designed composite materials for this purpose can meet the functional and structural requirements. In this paper, it is aimed to design the dimensionally stable laminated composites by using efficient global optimization method. For this purpose, the composite plate optimization problems have been solved for high stiffness and low coefficients of thermal and moisture expansion. Some of the results based on efficient global optimization solution have been verified by genetic algorithm, simulated annealing, and generalized pattern search solutions from the previous studies. The proposed optimization algorithm is also validated experimentally. After completing the design and optimization process, failure analysis of the optimized composites has been performed based on Tsai–Hill, Tsai–Wu, Hoffman, and Hashin–Rotem criteria.
Design of Jack-up Platform for 6 MW Wind Turbine: Parametric Analysis Based Dimensioning of Platform Legs
- Paweł Dymarski
2019 Full text Polish Maritime Research
The article presents the results of the research conducted within the framework of the project entitled WIND-TU-PLA (ERA-NET, MARTEC II), the general aim of which was to design and analyse supporting structures for wind turbines intended for operation on the South Baltic area. The research part described in the article aimed at developing a preliminary design for a jack-up platform which can operate on water areas with depth of 40 m. The main task was to determine optimal dimensions of platform legs and the radius of their spacing. Two jack-up platform concepts differing by spacing radius and hull dimensions were designed with the intention to be used as a supporting structure for a 6-MW offshore wind turbine. For each concept, the parametric analysis was performed to determine optimal dimensions of platform legs (diameter Dleg and plating thickness tleg). Relevant calculations were performed to assess the movements of the platform with parameters given in Table 1 in conditions simulating the action of the most violent storm in recent 50 years. The obtained results, having the form of amplitudes of selected physical quantities, are shown in comprehensive charts in Fig. 6 and 7. Based on the critical stress values (corresponding to the yield stress), the area was defined in which the impact strength conditions are satisfied (Fig. 14).Then, the fatigue strength analysis was performed for two selected critical leg nodes (Fig. 12). Its results were used for defining the acceptable area with respect to structure’s fatigue (Fig. 14). Geometric parameters were determined which meet the adopted criteria, Table 6. The decisive criterion turned out to be the fatigue strength criterion, while the yield point criterion appeared to be an inactive constraint.
Design of Microwave-Based Angular Displacement Sensor
- Abhishek Jha
- Nicolo Delmonte
- Adam Lamęcki
- Michał Mrozowski
- Bozzi Maurizio
2019 IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS
This letter presents a novel microwave-based rotation sensor having a wide dynamic range to detect and measure the angular displacement in terms of the change in resonant frequency. The proposed sensor is based on the microstrip technology, where a rotor comprised of a complementary splitring resonator (CSRR) placed on the ground plane of the microstrip line is free to rotate around its axis. The mechanical rotation of CSRR determines a change in the cross coupling between the microstrip line and the CSRR, thus changing the overall inductance. The proposed planar unloaded microwave sensor, working around ISM band of 5.8 GHz, is quite sensitive to detect angular rotation in the wide dynamic range of 0°–90°. The linearity in dynamic range is achieved in the range of 30°–60°. Operating frequency and bandwidth can be adjusted by loading the rotor with dielectric. Depending on the type of dielectric loading of CSRR, it is possible to select the center frequency from a wide range of 4.67–5.94 GHz, with the bandwidth ranging from 116 to 250 MHz. Due to its features, the proposed sensor can be useful for various industrial applications.
Design, synthesis, and molecular docking of new 5-HT reuptake inhibitors based on modified 1,2-dihydrocyclopenta[b] indol-3(4H)-one scaffold
- Milena Szewczyk
- Paweł Punda
- Karolina Janikowska
- Sławomir Makowiec
2019 Full text JOURNAL OF CHEMICAL SCIENCES
A new group of serotonin reuptake inhibitors containing 1,2-dihydrocyclopenta[b]indol-3(4H)-one scaffoldwas synthesized, starting from indole 5-((1H-indol-3-yl)(1,3-dioxane-4,6-diones as a key intermediates. Following three transformations including intramolecular cyclization and formation of imines, a series of new ligand for human serotonin transporter was obtained. The ability of these ligands to inhibit human TS3 serotonin transporter as well as selectivity toward human D3 dopamine receptor and dopamine transporter were tested in silico using docking software.
Detecting coupling directions with transcript mutual information: A comparative study
- José Amigó
- Beata Graff
- Grzegorz Graff
- Roberto Monetti
- Katarzyna Tessmer
2019 DISCRETE AND CONTINUOUS DYNAMICAL SYSTEMS-SERIES B
Causal relationships are important to understand the dynamics of coupled processes and, moreover, to influence or control the effects by acting on the causes. Among the different approaches to determine cause-effect relationships and, in particular, coupling directions in interacting random or deterministic processes, we focus in this paper on information-theoretic measures. So, we study in the theoretical part the difference between directionality indicators based on transfer entropy as well as on its dimensional reduction via transcripts in algebraic time series representations. In the applications we consider specifically the lowest dimensional case, i.e., 3-dimensional transfer entropy, which is currently one of the most popular causality indicators, and the (2-dimensional) mutual information of transcripts. Needless to say, the lower dimensionality of the transcript-based indicator can make a difference in practice, where datasets are usually small. To compare numerically the performance of both directionality indicators, synthetic data (obtained with random processes) and real world data (in the form of biomedical recordings) are used. As happened in previous related work, we found again that the transcript mutual information performs as good as, and in some cases even better than, the lowest dimensional binned and symbolic transfer entropy, the symbols being ordinal patterns.
Detection of debonding in adhesive joints using Lamb wave propagation
- Magdalena Rucka
- Erwin Wojtczak
- Jacek Lachowicz
2019 Full text MATEC Web of Conferences
Adhesively bonded joints are widely used in many branches of industry. Mechanical degradation of this type of connections does not have significant symptoms that can be noticed during visual assessment, so non-destructive testing becomes a very important issue. The paper deals with experimental investigations of adhesively bonded steel plates with different defects. Five samples (an intact one and four with damages in the form of partial debonding) were prepared. The inspection was conducted with the use of guided wave propagation method. Lamb waves were excited at one point of the sample, whereas the out-of-plane velocity signals were recorded in a number of points spread over the area of overlap. The processing of signals consisted of calculations of weighted root mean square (WRMS). The results of the analysis showed that the WRMS maps allow for identification and determination of size and shape of debonding areas.
Detection of the First Component of the Received LTE Signal in the OTDoA Method
- Gadka Paweł
- Jarosław Sadowski
- Jacek Stefański
2019 Full text WIRELESS COMMUNICATIONS & MOBILE COMPUTING
In a modern world there is a growing demand for localization services of various kinds. Position estimation can be realized via cellular networks, especially in the currently widely deployed LTE (Long Term Evolution) networks. However, it is not an easy task in harsh propagation conditions which often occur in dense urban environments. Recently, time-methods of terminal localization within the network have been the focus of attention, with the OTDoA (Observed Time Difference of Arrival) method in particular. One of the main factors influencing the accuracy of location estimation in the OTDoA method is the nature of the propagation channel that affects the ease of isolating the signal component travelling from the transmitter to the receiver through the shortest path. To obtain the smallest possible localization error, it is necessary to detect the first received component of the useful signal. This aim could be achieved by using a proper algorithm within the receiver. This paper proposes a new algorithm for effective detecting of the first component of the LTE downlink signal in the multipath environment. In a mobile terminal location estimation process, CSRS (Cell Specific Reference Signal) signals were used instead of dedicated PRS (Positioning Reference Signal) signals. New solution was verified during the measurement campaign in a real LTE network.
Detection of the Oocyte Orientation for the ICSI Method Automation
- Magdalena Mazur-Milecka
- Emilia Kaczmarczyk
- Łukasz Wróbel
- Patryk Przybylski
- Marika Trudnowska
- Aleksandra Podwójcik
- Monika Jagiello
- Krzysztof Łukaszuk
- Jacek Rumiński
2019 Full text
Automation or even computer assistance of the popular infertility treatment method: ICSI (Intracytoplasmic Sperm Injection) would speed up the whole process and improve the control of the results. This paper introduces a preliminary research for automatic spermatozoon injection into the oocyte cytoplasm. Here, the method for detection a correct orientation of the polar body of the oocyte is presented. Proposed method uses deep learning U-Net architecture for object segmentation. This solution proved to be universal and had no demand for numerous dataset or high-quality Images.
Detection of the Plant Pathogen Pseudomonas Syringae pv. Lachrymans on Antibody-Modified Gold Electrodes by Electrochemical Impedance Spectroscopy
- Zofia Cebula
- Sabina Żołędowska
- Karolina Dziąbowska
- Marta Skwarecka
- Natalia Malinowska
- Wioleta Białobrzeska
- Elżbieta Czaczyk
- Katarzyna Siuzdak
- Mirosław Sawczak
- Robert Bogdanowicz
- Dawid Nidzworski
2019 Full text SENSORS
The present work describes an impedimetric immunosensor for Pseudomonas syringae pv. lachrymans (Psl) detection. This pathogen infects many crop species causing considerable yield losses, thus fast and cheap detection method is in high demand. In the assay, the gold disc electrode was modified with 4-aminothiophenol (4-ATP), glutaraldehyde (GA), and anti-Psl antibodies, and free-sites were blocked with bovine serum albumin (BSA). Sensor development was characterized by cyclic voltammetry (CV) and antigen detection by electrochemical impedance spectroscopy (EIS) measurements. Seven analyzed strains of Psl were verified as positive by the reference method (PCR) and this immunoassay, proving sensor specificity. Label-free electrochemical detection was in the linear range 1 × 103–1.2 × 105 CFU/mL (colony-forming unit) with an R2 coefficient of 0.992 and a detection limit (LOD) of 337 CFU/mL. The sensor did not interfere with negative probes like buffers and other bacteria. The assay was proven to be fast (10 min detection) and easy in preparation. The advantage was the simplicity and availability of the verified analyte (whole bacteria) as the method does not require sample pretreatment (e.g., DNA isolation). EIS biosensing technique was chosen as one of the simplest and most sensitive with the least destructive influence on the probes compared to other electrochemical methods.