2019 - Publications Repository - Gdańsk University of Technology

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Publications from the year 2019

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Comparison of Properties of the Hybrid and Bilayer MWCNTs—Hydroxyapatite Coatings on Ti Alloy
- Beata Majkowska-Marzec
- Rogala-Wielgus Dorota
- Michał Bartmański
- Bartosewicz Bartosz
- Andrzej Zieliński
2019 Full text Coatings
Carbon nanotubes are proposed for reinforcement of the hydroxyapatite coatings to improve their adhesion, resistance to mechanical loads, biocompatibility, bioactivity, corrosion resistance, and antibacterial protection. So far, research has shown that all these properties are highly susceptible to the composition and microstructure of coatings. The present research is aimed at studies of multi-wall carbon nanotubes in three different combinations: multi-wall carbon nanotubes layer, bilayer coating composed of multi-wall carbon nanotubes deposited on nanohydroxyapatite deposit, and hybrid coating comprised of simultaneously deposited nanohydroxyapatite, multi-wall carbon nanotubes, nanosilver, and nanocopper. The electrophoretic deposition method was applied for the fabrication of the coatings. Atomic force microscopy, scanning electron microscopy and X-ray electron diffraction spectroscopy, and measurements of water contact angle were applied to study the chemical and phase composition, roughness, adhesion strength and wettability of the coatings. The results show that the pure multiwall carbon nanotubes layer possesses the best adhesion strength, mechanical properties, and biocompatibility. Such behavior may be attributed to the applied deposition method, resulting in the high hardness of the coating and high adhesion of carbon nanotubes to the substrate. On the other hand, bilayer coating, and hybrid coating demonstrated insufficient properties, which could be the reason for the presence of soft porous hydroxyapatite and some agglomerates of nanometals in prepared coatings.
Comparison of properties of the new electro-mechanical model and circumferential model of the inductive-dynamic drive
- Piotr Jankowski
- Mirosław Wołoszyn
2019 INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS
The article presents a new electromechanical model of inductive-dynamic drive. The model is implemented in two environments: Maxwell for analyzing electrodynamic phenomena including moving of the disc and Ansys which allows for stress analysis on the basis of the volume forces imported from Maxwell. Additionally, a model validation by comparing with the existing circumferential model was carried out.
Comparison of Redox Properties of Flavonoid Aglycones and Corresponding Glycosides and Their Mixtures in the Cellular Model
- Zuzanna Koziara
- Monika Baranowska
- Agnieszka Bartoszek-Pączkowska
- Jacek Namieśnik
2019 Full text Proceedings
Flavonoids are polyphenolic compounds commonly found in plants. As dietary components, they have been shown to exhibit numerous pro-health properties that are believed to be associated with their antioxidant effects. In this study, the antioxidant activity of four flavonoid compounds was determined by cellular antioxidant activity assay using HT29 cells as a model of the alimentary tract. The strongest impact on cellular redox status was observed for aglycones which acted as both antioxidants (quercetin) and prooxidants (naringenin). Interestingly, mixtures of tested compounds displayed only antioxidative properties.
Comparison of Surface Quality and Tool-Life of Glulam Window Elements after Planing
- Michał Dobrzyński
- Kazimierz Orłowski
- Michał Biskup
2019 Full text Drvna Industrija
The quality of the surface of wooden elements, that have been planed, has a crucial importance in the whole production process, since the obtained effects affect the quality of wooden surface after fi nishing (painting). The occurrence of defects is usually the reason for qualifying a workpiece as scrap or for requiring additional work. This paper presents the selected results of research of the effect of the cutting tool wear on the surface quality of elements after planing. Research experiments were conducted on the SCM Superset Class machine tool. Glulam elements of pine wood (Pinus sylvestris L.) were researched. The raw material samples (semi-fi nished products), 6 m long before planing, had been machined by suppliers also by planing. These workpieces were selected according to the plant requirements, e.g. their moisture content, straightness, and other defects. This paper presents the measuring results of surface roughness and some examples of surface profi les, as well as the dependence of total length of the planed elements on the type of blade material. From an economic point of view, the results showed that the use of solid carbide blades were more cost effective.
Comparison of technology adoption models
- Agnieszka Landowska
2019
There are several technology adoption models, that try to explain, how and why the technologies are adopted and used. Among those, that are widely used to explain, how the older adults accept technologies, there are some general models and models specific to the group of older users. Among the general ones I would recommend paying attention to the following models: Technology Acceptance Model (TAM) proposed by Davis (Davis, 1989), Extended Technology Acceptance Model (TAM2), Extended (contextual) Technolo-gy Acceptance Model (TAM3) and Unified Theory of Acceptance and Use of Technology(UTAUT). Among the ones specific for the group of older users there are: Senior TechnologyAcceptance Model (STAM), Extended Technology Acceptance Model for the Elderly (ETA-ME), Model of Technology Adoption by Older Adults (MATOA) and Elderadopt. The models were identified with the literature review held by SHELD-ON participants (Sheld-on, 2019). This paper provides a brief comparison of the models.
Comparison of the effectiveness of automatic EEG signal class separation algorithms
- Adam Kurowski
- Katarzyna Mrozik
- Bożena Kostek
- Andrzej Czyżewski
2019 Full text JOURNAL OF INTELLIGENT & FUZZY SYSTEMS
In this paper, an algorithm for automatic brain activity class identification of EEG (electroencephalographic) signals is presented. EEG signals are gathered from seventeen subjects performing one of the three tasks: resting, watching a music video and playing a simple logic game. The methodology applied consists of several steps, namely: signal acquisition, signal processing utilizing z-score normalization, parametrization and activity classification. The EEG signal is acquired from a headset containing 14 electrodes. For the parametrization two methods are used, namely, DiscreteWavelet Transform (DWT) employed as a reference parametrization technique and autoencoder neural network. Parameters obtained with those methods are fed to the input of classifiers which assigned them to one of three activity classes. Then, the effectiveness of the assignment of the frames of EEG data into appropriate classes is observed and compared. Results obtained using both methods show differences in accuracy with regard to the task detected depending on factors such as type of parametrization or complexity of the classifier employed for EEG activity classification.
Comparison of the paracetamol electrochemical determination using boron-doped diamond electrode and boron-doped carbon nanowalls
- Paweł Niedziałkowski
- Zofia Celuba
- Natalia Malinowska
- Wioleta Białobrzeska
- Michał Sobaszek
- Mateusz Ficek
- Robert Bogdanowicz
- Jacek Sein Anand
- Tadeusz Ossowski
2019 Full text BIOSENSORS & BIOELECTRONICS
Two different type of electrodes, boron-doped diamond electrode (BDD) and boron-doped carbon nanowalls (B:CNW) electrode, were used for the electrochemical determination of paracetamol using the cyclic voltammetry and the differential pulse voltammetry in phosphate buffered saline, pH = 7.0. The main advantage of these electrodes is their utilization without any additional modification of the electrode surface. The peak current was linearly related to the concentration of paracetamol in the range from 0.065 µM to 32 µM for BDD electrode and from 0.032 µM to 32 µM for B:CNW electrode. The limit of detection was 0.430 µM and 0.281 µM for BDD and B:CNW electrode, respectively. Additionally, we studied the effect of pH on the redox reaction of paracetamol at the both electrodes in Britton-Robinson buffer solution in the range of pH 3.0–12.0, indicating the pH 7.0 value as the most suitable for the current experiments. The studies also included the various scan rates in range of 50–500 mV/s. Finally, our team selected the B:CNW electrode for the determination of paracetamol in the artificial urine sample using differential pulse voltammetry method, obtaining the calculated limit of detection on the level of 0.08006 µM.
Compensation Topologies in IPT Systems: Standards, Requirements, Classification, Analysis, Comparison and Application
- Viktor Shevchenko
- Oleksandr Husev
- Ryszard Strzelecki
- Bohdan Pakhaliuk
- Nikolai Poliakov
- Natalia Strzelecka
2019 Full text IEEE Access
Wireless power transfer devices are becoming more relevant and widespread. Therefore, an article is devoted to a review, analysis and comparison of compensation topologies for an inductive power transfer. A new classification of topologies is developed. A lot of attention is paid to the problems of the physical fundamentals of compensation work, standards, safety, and five main topology requirements. It is determined, that topologies with the series primary compensating are the most effective in the IPT for charging devices among the four classical schemes. The series-parallel solution is recommended in case of the low output voltage, minimum size of a secondary side coil is achievable. The series-series solution does not depend on the magnetic coupling coefficient and the load on the resonance frequency. For the convenience of displaying and understanding the information, the comparison results are listed in the tables, graphs and dependencies. The main suitable topologies for a certain application are defined. The given conclusions provide a “one-stop” information source and a selection guide on the application of compensation topologies both in terms of devices and in terms of power level that is the main value of this paper. During literature analysis and recent trends in the market for wireless power transmission devices, the main possible further ways of developing topologies are underlined. First of all, it concerns increasing the frequency of resonance of compensation topologies, the use of multilevel / multi-pulse / multicoils structures, the study of existing high-frequency semiconductors and the development of the semiconductor and magnetic materials.
Compressed Projection Bases for Model-Order Reduction of Multiport Microwave Components Using FEM
- Martyna Mul
- Damian Szypulski
- Grzegorz Fotyga
- Michał Mrozowski
2019 Full text
This paper presents a projection basis compression technique for generating compact reduced-order models (ROM) in the FE analysis of microwave devices. In this approach redundancy is removed from the projection basis by means of the proper orthogonal decomposition technique applied to the projected system of linear equations. Compression allows for keeping the size of a reduced-order model as small as possible without compromising ROM’s accuracy. Effectiveness of the basis compression technique, including memory and time consumption as well as the size of the resultant ROM, are discussed for both global and local model-order reduction schemes.
Computational collective intelligence for enterprise information systems
- Ngoc-Thanh Nguyen
- Dosam Hwang
- Edward Szczerbicki
2019 Enterprise Information Systems
Collective intelligence is most often understood as a kind of intelligence which arises on the basis of a group (collective) of autonomous unites (people, systems) which is taskoriented. There are two important aspects of an intelligent collective: The cooperation aspect and the competition aspect (Levy 1997). The first of them means the possibility for integrating the decisions made by the collective members for creating the decision of the collective as a whole. The second aspect, on the other hand, states the diversity of the collective members. It has been proved that for prediction market tasks, these two aspects have an important impact on the collective prediction accuracy. This means, in the general case, that owing to manipulating them one can achieve a given level of intelligence for a collective (Maleszka and Nguyen 2015; Nguyen and Nguyen 2018).
Computational Fluid Dynamic study on the wind characteristics of a multifunctional building system model in developed coastal cities
- Mateusz Gerigk
- Jacek Jachowski
2019 Full text Zeszyty Naukowe Akademii Morskiej w Szczecinie
This paper presents an approach for providing innovative technology by applying fluid mechanics to the field of architectural design. The aim is to make a building’s shape profitable and strengthen environmental protection by using the wind force to create an integrated wind absorption definition for a multifunctional building system model. Furthermore, taking control of the wind flow over an object can have an impact on not only the designed object itself but also on its surroundings. In modern coastal cities there are issues associated with the wind and ventilation that need to be solved. The presented system model and the calculations conducted are part of the new definition of a multifunctional object and the wind force as a significant subsystem. Systematizing this scope can be useful in design practice.
Computationally Effcient Solution of a 2D Diffusive Wave Equation Used for Flood Inundation Problems
- Wojciech Artichowicz
- Dariusz Gąsiorowski
2019 Full text Water
This paper presents a study dealing with increasing the computational efficiency in modeling floodplain inundation using a two-dimensional diffusive wave equation. To this end, the domain decomposition technique was used. The resulting one-dimensional diffusion equations were approximated in space with the modified finite element scheme, whereas time integration was carried out using the implicit two-level scheme. The proposed algorithm of the solution minimizes the numerical errors and is unconditionally stable. Consequently, it is possible to perform computations with a significantly greater time step than in the case of the explicit scheme. An additional efficiency improvement was achieved using the symmetry of the tridiagonal matrix of the arising system of nonlinear equations, due to the application of the parallelization strategy. The computational experiments showed that the proposed parallel implementation of the implicit scheme is very effective, at about two orders of magnitude with regard to computational time, in comparison with the explicit one.
Concentration levels of selected analytes in the gas phase of an e-cigarette aerosol
- Justyna Aszyk
- Mateusz Kacper Woźniak
- Paweł Kubica
- Agata Kot-Wasik
- Andrzej Wasik
2019 Full text MICROCHEMICAL JOURNAL
The aerosols generated from e-cigarettes are composed of liquid and gas phases resulting from vapourized e-liquid. The apportioning of substances from e-liquid into the liquid and gas phases during e-cigarette use has not been extensively studied. Partitioning of e-liquid components between the gas and the liquid phase of the aerosol influences the substances inhaled and exhaled by the users, leading to second-hand exposure. It seems important to determine which compounds and how much of them are transferred into the gas phase and may immediately enter the bloodstream. For this purpose, a method based on thermal desorption followed by gas chromatography coupled with tandem mass spectrometry (GC–MS/MS) in electron ionization mode was developed. As in a previous study, an automatic generator of an aerosol from an e-cigarette with a collection tube filled with melt-blown non-woven fabric discs and equipped with Tenax TA sorption tubes was used. The melt-blown non-woven fabric is designed to capture liquid phase compounds, while sorption tubes are meant to sorb compounds in the gas phase of the aerosol. To control the e-liquid mass changes before and after a puff session, quantitation based on the mass change tracking approach (MCT) was applied. Accuracy of the developed method ranged between 91% and 110% regardless of the spiking level, with precision and reproducibility better than 10%. The limits of detection (LODs) ranged from 0.015 to 0.076 ng of substance emitted/mg of consumed e-liquid, while limits of quantitation (LOQs) ranged from 0.045 to 0.23 ng of substance emitted/mg of consumed e-liquid. Most of the compounds are deposited in the liquid phase of the aerosol, while only trace levels of some substances may be observed in an actual, non-condensed gas phase.
Concentrations and loads of DOC, phenols and aldehydes in a proglacial arctic river in relation to hydro-meteorological conditions. A case study from the southern margin of the Bellsund Fjord – SW Spitsbergen
- Sara Lehmann-Konera
- Waldemar Kociuba
- Stanisław Chmiel
- Łukasz Franczak
- Żaneta Polkowska
2019 CATENA
Climate warming accelerates the melting and thawing of cryosphere components. Therefore, it favours the release of contaminants stored in High-Arctic glaciers for many years. The rate of land-based glacier retreat is of particular importance for the hydrological regime of glacial rivers, but also for the chemical composition of their waters. In this study, we examined 84 surface water samples collected during a period of 42 days (melt season 2012) from the Scott River of glacial-hydrological regime (NW Wedel-Jarlsberg Land). The studies of Scott River hydro-meteorological conditions provided indication on the relation between mean air temperatures (T) and mean daily discharge (Q) (r = 0.67). Moreover, they confirmed the role of short-term meteorological events (increasing of air temperature and heavy precipitation) on the acceleration of glacier melt. In this context, the study also demonstrated incidents of the release of a more concentrated pulse of chemical compounds delivered by the Scottbreen valley glacier. The analysis covered fluctuations of physicochemical parameters, and presence of selected organic pollutants (∑phenols, formaldehyde (HCHO)). Based on the correlation matrix analysis, it was found that fluctuations of physicochemical indices (pH, specific electrolytic conductivity (SEC) and dissolved organic carbon (DOC)) were related to changes in T and Q. Principal components analysis (PCA)permitted us to distinguish two principal components (hydro-meteorological and biogeochemical conditions) responsible for 71.1% of the total hydrochemical variation. In terms of the first principal component, it was found that there was a relationship with the intensified ablation of glacier ice and with the second one, the influence of geological and biological conditions of the environment on the chemistry of the river. The combination of these factors directly shaped the hydrochemistry of the proglacial river during the melt season of 2012. The results of organic compound loads, which are presented in this paper provide unique information about the transport of contaminants such as: (DOC) (9.41–579 mgC s−1), ∑phenols (19.7–534 mg s−1), HCHO (34.0–82.3 mg s−1)) in the Scott River. It is worth noting that the differentiation of concentration and mean daily loads of DOC, between the gorge (96.0 mgC s−1) and mouth (99.6 mgC s−1) sections of the river, were related with the activity of a herring gull (Larus argentatus) colony at the river mouth.
Concrete mix design using machine learning
- Patryk Ziółkowski
- Maciej Niedostatkiewicz
2019
Designing a concrete mix is a process of synthesizing many components, it is not a simple process and requires extensive technical knowledge. The design process itself focuses on obtaining the required strength of concrete. Very often designing a concrete mix takes into account the need to maintain the proper water-demand and frost-resistance features. The parameters that influence the concrete class most significantly are the water-cement ratio along with the type and amount of cement and aggregate (crumb pile composition). However, in practice, the design of a concrete mix is done using additives, the so-called plasticizers, which are workability improving agents, as well as increasing frost resistance and aeration. Nowadays, the most widely used concrete mix design approaches are computational-experimental methods based on three-equations method, which allow estimating the amount of aggregate, cement and water. The results obtained in such a way requires laboratory verification. An entirely new approach is a prediction of concrete strength using extensive databases and machine learning algorithms, which can bring some potential benefits, the most important of which is the automation of the concrete mix design process. This paper aims to present preliminary work on the application of data mining in a concrete mix designing process. The primary parameter of concern is concrete compressive strength. The analysis is base on ready-made formulas of concrete mixes from personal resources, prepared for structural concretes of various classes. Furthermore, recently many researchers work on developing perfect concrete compressive strength prediction formula, which makes it an active field of research. © Federation Internationale du Beton (fib) - International Federation for Structural Concrete, 2019.
Condition of Reinforced Concrete Structures and Their Degradation Mechanism at the Former Auschwitz Concentration and Extermination Camp
- Michał Szociński
- Andrzej Miszczyk
- Kazimierz Darowicki
2019 Full text STUDIES IN CONSERVATION
This paper presents the results of investigations on reinforced concrete structures present in the former Auschwitz I and Auschwitz II-Birkenau concentration and extermination camp. Field inspection employing the non-destructive method of reinforcement potential measurement according to the ASTM-C 876–15 standard, followed by laboratory investigations performed on genuine historic reinforced concrete samples collected from the former Auschwitz camp, allowed assessment of the actual condition of this 70-year-old construction material. Electrochemical potential measurements allowed mapping of the regions characterized by enhanced reinforcement corrosion risk and the regions of its immunity. The composition of concrete, water absorbency, content of detrimental salts, and degree and profile of carbonation as well as mechanical properties were evaluated. Results revealed the most common and probable mechanism responsible for degradation of the reinforced concrete structures in the former Auschwitz camp.
CONDITIONS, STREAM AND OUTLOOK FOR ECONOMIC MIGRATION FROM ASIA TO POLAND
- Robert Sterniński
2019
The aim of the article is to present the data about the conditions and perspectives of economic migration from Asia to Poland and data on the stream of this phenomenon in recent years based on work permission documents. The first part presents an introduction on the general migration situation to Poland in recent years and describes the theoretical approach to the aspect of migration. Then the legal conditions of migrants' work in Poland and the method of obtaining data for the purposes of the survey were presented. The study was conducted on the basis of issued work permits and declarations of entrustment of work for migrants from Asia. The last part summarizes and presents the conclusions.
Constant vs. Variable Efficiency of Electric Drive in Train Run Simulations
- Aleksander Jakubowski
- Leszek Jarzębowicz
2019 Full text
Train run simulations, which focus on various power- and energy-oriented aspects, should reflect the losses in the electric powertrain. In general, the powertrain efficiency varies with respect to load and speed. Including this relation in simulation requires knowledge about detailed drivetrain parameters, which are often unavailable. This paper verifies the possibility to approximate the drivetrain efficiency in train run simulations by an equivalent constant that provides the same results of total energy usage. A case study of a suburban electric traction unit was selected to compare results of simulations carried out for different operating conditions including: route length, cruising speed and route inclination. The impact of replacing the variable efficiency with the equivalent constant on various outcomes of train run simulations was discussed and the limitations were formulated.
Constrained optimization for generating gain-bandwidth design trade-offs of wideband unidirectional antennas
- Sławomir Kozieł
- Adrian Bekasiewicz
2019 IET Microwaves Antennas & Propagation
Broadband unidirectional antennas realised in microstrip technology find applications in many wireless communication systems. One of their design challenges is the necessity of handling multiple performance figures which is difficult when using traditional design methods, largely based on parameter sweeping. This work presents a simple optimisation-based framework that permits generation of gain-bandwidth trade-off designs for this class of antenna structures. The proposed methodology exploits sequentially executed constrained optimisation runs which produce maximum-gain designs across the range of prescribed target impedance bandwidths. To control the latter, design constraints are imposed on the reflection response but also on gain variability to ensure flat in-band characteristics. For the sake of demonstration, an example compact wideband quasi-Yagi antenna is considered for which a set of trade-off designs is obtained with the impedance bandwidth varied from 9 to over 54%, and corresponding gain levels from 7.4 dB to around 5.5 dB, which determines the antenna capabilities in terms of these performance figures. The approach proposed in this work can be utilised as a design aid as well as a tool for quantitative performance comparison of different (alternative) antenna topologies.
CONSUMERS’ APPROACH TO THE CREDIBILITY OF THE INFLATION FORECASTS PUBLISHED BY CENTRAL BANKS: A NEW METHODOLOGICAL SOLUTION
- Karolina Tura-Gawron
2019 Full text JOURNAL OF MACROECONOMICS
Modern monetary policy focuses on credibility and shaping inflation expectations. In keeping with the concept of inflation forecast targeting, the inflation forecasts published by central banks play a crucial role in the instrument rate decision-making process and may be treated as a specific intermediate target. This study proposes an inflation forecast credibility index, the scope of which is narrowed to non-specialists’ approach to inflation forecasts. The credibility of the forecast is defined as the ability to shape consumers’ inflation expectations. This ability is measured as the absolute difference between the central paths of inflation forecasts (the mode values) in the one-year forecast horizon and one-year consumers’ inflation expectations. The inflation forecast is represented in the study as a function of forecast attributes (accuracy, similarity, and deviation from the inflation target). The credibility function of the forecast is derived from belief function theory, normally distributed, and determined by the linear function of the chosen forecast attributes. The importance of these attributes depends on whether monetary policy was conducted before or after reaching the zero lower bound on the policy rate. The credibility index is calculated for the inflation forecasts published by the central banks of the United Kingdom and Sweden. The main conclusion of the study is that the deviations of the forecast in the last year of the forecast horizon and similarity between consecutive forecasts are important forecast attributes for shaping the inflation expectations of consumers before and after reaching the zero lower bound on the policy rate, and may determine the inflation forecast’s credibility. However, the similarity to consecutive forecasts affects the forecast’s credibility in opposite ways before and after reaching the zero lower bound on the policy rate.