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Gdańsk University of Technology

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Publications from the year 2023

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  • Stenty naczyniowe – problematyka i biomateriały
    • Klaudia Malisz
    • Marcin Hellmann
    • Beata Świeczko-Żurek
    2023

    Angioplastyka z opcjonalną implantacją stentu odgrywa ważną rolę w leczeniu chorób układu sercowo-naczyniowego w przebiegu miażdżycy. Obecnie na rynku można znaleźć implanty naczyniowe z różnych materiałów, pomimo tego nadal prowadzone są badania nad nowymi technologiami zapewniającymi lepsze własności mechaniczne, fizykochemiczne i biologiczne powłokom, a także usprawniającymi sposoby uwalniania leków. Stenty uwalniające leki dostarczają środki antyproliferacyjne, co znacznie obniża częstość nawrotów zwężenia w porównaniu ze stentami z czystego metalu. Chociaż w pełni biodegradowalne rusztowania potencjalnie mają zapobiegać późnym powikłaniom, nie osiągnęły jeszcze wyników równoważnych z wynikami konwencjonalnych metalowych stentów uwalniających leki we wczesnych latach po implantacji. Innym rozwiązaniem jest zastosowanie powłok, które nadają wyjątkowych właściwości materiałowi, np. wykorzystując powłoki diamentopodobne lub domieszkując powłokę nanocząstkami. Celem niniejszego artykułu jest przedstawienie najnowszych materiałów do stosowania w kardiologii i angiologii interwencyjnej jako stenty naczyniowe.

  • Sterowanie predykcyjne i fuzja danych w systemie dynamicznego pozycjonowania statku
    • Krzysztof Jaroś
    2023 Full text

    Rozprawa doktorska poświęcona jest badaniu zastosowania fuzji danych oraz sterowania predykcyjnego w systemie dynamicznego pozycjonowania statku. W pierwszej części pracy przedstawiono historię rozwoju systemów dynamicznego pozycjonowania, różne metody estymacji położenia statku, metody sterowania oraz cel i tezę pracy. Następnie zaprezentowano model matematyczny statku, kinematykę oraz dynamikę. W kolejnej części przedstawiono algorytmy fuzji danych, takie jak filtr Kalmana, rozszerzony filtr Kalmana, nieliniowy obserwator oraz filtr cząsteczkowy. W rozprawie przedstawiono również algorytm kaskadowego połączenia filtru cząsteczkowego i rozszerzonego filtru Kalmana. W kolejnej części zaprezentowano algorytmy sterowania, takie jak PID, regulator backstepping oraz sterowanie predykcyjne. W pracy przedstawiono dwa kierunki badań. Pierwszy dotyczy zadania fuzji danych z wykorzystaniem nadmiarowej struktury pomiarowej dokonującej pomiaru położenia, kursu i prędkości w celu estymacji tych wielkości i zakłóceń środowiskowych. Drugi kierunek badań dotyczy poprawy jakości sterowania statkiem z wykorzystaniem nieliniowego modelu statku w sterowaniu predykcyjnym. Wyniki tych badań wskazują, że połączenie fuzji danych i sterowania predykcyjnego pozwala na zwiększenie dokładności pozycjonowania statku oraz bezpieczeństwa statku w sytuacjach awaryjnych.

  • Stiffness of cold-recycled mixtures under variable deformation conditions in the IT-CY test
    • Mariusz Jaczewski
    • Cezary Szydłowski
    • Bohdan Dołżycki
    2023 Full text Case Studies in Construction Materials

    Stiffness modulus belongs to the most important properties describing the cold-recycled mixtures (CRM) in terms of their usability in road pavement structures. Previous research proved that this property is strongly dependent on the scheme and conditions of the test (temperature and time of loading) and the time that has passed since the compaction of the specimen or pavement layer. It is a result of the influence of two different types of bonds – hydraulic bonds from cement and bituminous bonds from bituminous emulsion or foamed bitumen. Research presented in this paper showed that the target horizontal deformation values selected during the stiffness modulus test have a strong impact on the obtained results as well. In this paper the popular Indirect Tensile Stiffness Modulus (ITSM) test on cylindrical specimen (IT-CY scheme) was used to show the dependence of the stiffness modulus values on the selected target horizontal deformation level. Research was conducted on four different CRM mixtures and three reference materials. The research proved that even for a narrow deformation range the CRMs do not present linear viscoelastic behavior and display very high effort of material even for typical test conditions. In consequence, they are very prone to failure. Research also proved that CRM mixtures present different rheological behavior than cement concrete or asphalt concrete, and more attention should be given to establishing proper test conditions. Based on the research, it was determined that the recommended target horizontal deformation in IT-CY test of CRM should be reduced to 3 μm.

  • Stochastic optimisation algorithm for optimisation of controller parameters for control of dissolved oxygen in wastewater treatment plant
    • Robert Piotrowski
    • Michał Wonia
    • Adam Wonia
    2023 Journal of Water Process Engineering

    Wastewater treatment plants (WWTPs) are very important facilities for mankind. They enable the removal and neutralisation of man-made pollutants. Therefore, it is important for wastewater treatment plants to operate as efficiently as possible so that the level of pollutants in the treated wastewater meets specific requirements. This paper concerns the design of a hierarchical nonlinear adaptive control system for dissolved oxygen (DO) concentration in wastewater for a biological Sequential Batch Reactor (SBR). The parameters of the control system used are optimised to ensure the best possible control quality and low energy consumption at the same time. Based on data collected from a case study WWTP, an Activated Sludge Model 2d (ASM2d) of the biological processes and a model of the aeration system are applied. The Coyote Optimization Algorithm (COA) is used to optimize the adaptive controller parameters. A Proportional-Integral-Derivative (PID) control system is also developed to compare the control results. The results obtained from simulation studies for both control systems are presented. As a result of optimised parameters, higher wastewater treatment efficiency and reduced electricity consumption are achieved.

  • Stock Markets’ Reactions to the Announcement of the Hosts. An Event Study in the Analysis of Large Sporting Events in the Years 1976–2032
    • Krystian Zawadzki
    • Marcin Potrykus
    2023 Full text Journal of Sports Economics

    This study attempts to estimate the impact of the announcements of hosts of large sporting events on domestic stock markets. The research problem is to establish a connection between the uniqueness of a sporting event and investors’ beliefs through stock price behavior. Using appropriate estimation windows, 13 different sporting events classified as large, including mega and major events, were tested. The obtained results show that, in principle, one day after the announcement of the host of a large sporting event, an average positive reaction of 0.22% is observed on national stock exchanges. The analyzed events were also classified as being neutral for capital markets or generating positive or negative reactions when the host country is announced to the public.

  • Strategies for Dealing With Software Product Management Challenges
    • Olga Springer
    • Jakub Miler
    • Michał Wróbel
    2023 Full text IEEE Access

    Software product management, which involves multiple processes and responsibilities and links to many activities within the organisation, increases the success rate of IT projects. However, the adoption of product management activities and the implementation of the software product manager role itself varies between companies. This research explores the topic of software product managers’ strategies for dealing with challenges in their work. The aim of the study is to identify and evaluate solutions to the main problems that affect the software product management process and to provide guidelines for dealing with them. For this purpose, a focus group method was adopted and 47 software product managers participated in 15 focus groups. This was followed by a survey to assess the comprehensibility and effectiveness of the solutions identified. The paper proposes a list of 39 solutions to the 5 most common problems in the work of product managers. Furthermore, based on the identified solutions and the results of discussions with experienced professionals during the focus groups, guidelines for these problems were also developed. These guidelines can be used by product managers as well as other roles working in the product development team to create their own strategies for overcoming software product management challenges and improving software engineering practices. Finally, the solutions and guidelines presented, when combined with a list of problems identified in previous research, will form a Software Product Management Guide – a framework currently under construction, as part of wider research, for product development teams to improve software engineering practices.

  • Strategy towards the use of ultrafiltration and reverse osmosis for industrial water recovery and reuse as part of the Green Deal Implementation
    • Jakub Drewnowski
    • Jan Marjanowski
    • Maciej Sadaj
    • Bartosz Szeląg
    • Joanna Szulżyk-Cieplak
    • Grzegorz Łagód
    2023 Desalination and Water Treatment

    In line with the European Parliament’s Resolution of February 10th, 2021 on the new action plan for a closed economy, most of the activities undertaken in the wastewater treatment process should focus on the search for new technologies that use wastewater as a source of water and nutrients. The paper reviews the concept of water reuse in industrial installations, with special emphasis on the use of membrane technologies for this purpose. The results of authors’ own research on effectiveness of using ultrafiltration (UF) and reverse osmosis (RO) processes to recover process water from brewery wastewater, following pretreatment by the BIOPAQ®-IC process, are presented. Raw wastewater, after averaging the parameters, was digested in an anaerobic reactor, followed by deodorization and oxidation of sulfides to sulfate in an oxidation process in a pretreatment tank. The water recovered from pretreated brewery wastewater by UF and RO membrane techniques was found to be suitable for boiler feed, cooling technology and washing process without directly cleaning beer bottles. The study used a ZeeWeed capillary immersion ultrafiltration module operating under vacuum and a module equipped with a Filmtec XLE 2125 reverse osmosis membrane. The technology improved the efficiency of contaminant removal, yielding purified and high-quality water toward the implementation of the assumptions of Circular Economy and Green Deal Implementation.

  • Stress Relaxation Behaviour Modeling in Rigid Polyurethane (PU) Elastomeric Materials
    • Paweł Zielonka
    • Krzysztof Junik
    • Szymon Duda
    • Tomasz Socha
    • Krzysztof Kula
    • Arkadiusz Denisiewicz
    • Olaleye Kayode
    • Wojciech Macek
    • Grzegorz Lesiuk
    • Wojciech Błażejewski
    2023 Full text Materials

    Polyurethane (PU) has been used in a variety of industries during the past few years due to its exceptional qualities, including strong mechanical strength, good abrasion resistance, toughness, low-temperature flexibility, etc. More specifically, PU is easily “tailored” to satisfy particular requirements. There is a lot of potential for its use in broader applications due to this structure–property link. Ordinary polyurethane items cannot satisfy people’s increased demands for comfort, quality, and novelty as living standards rise. The development of functional polyurethane has recently received tremendous commercial and academic attention as a result. In this study, the rheological behavior of a polyurethane elastomer of the PUR (rigid polyurethane) type was examined. The study’s specific goal was to examine stress relaxation for various bands of specified strains. We also suggested the use of a modified Kelvin–Voigt model to describe the stress relaxation process from the perspective of the author. For the purpose of verification, materials with two different Shore hardness ratings—80 and 90 ShA, respectively—were chosen. The outcomes made it possible to positively validate the suggested description in a variety of deformations ranging from 50% to 100%.

  • Structural and electronic properties of diamond-composed heterostructures
    • Michał Rycewicz
    2023 Full text

    Diamond is a promising material for 21st century electronics due to its high thermal and electronic conductivity, biocompatibility, chemical stability, high wear resistance, and possibility of doping. However, the semiconductor properties of diamond, especially free-standing films, have not been fully explored. Nor have their integration with polymers and fragile materials and their applications as electronic components. In this thesis, the objective was the fabrication of heterostructures containing diamond films on flexible surfaces for application in electronic devices using the change of electrical parameters under the influence of external factors. To overcome this scientific challenge, boron-doped diamonds were grown using chemical vapour deposition on tantalum. After their delamination, the resulting free-standing films were investigated and analysed using Raman spectroscopy, Scanning and Atomic Force Microscopy, Nanoindentation Tests, Electrochemical measurements, and Electrical Evaluation as a function of temperature. Next, the diamond films were utilised for fabricating six heterostructures. Based on the conducted research, these heterostructures can be used as durable, transparent electrodes, strain sensors, Schottky or Ohmic junctions, capacitors, trinitrotoluene sensors, and as a protective layer for transistors.

  • Structural and luminescence properties of B2O3-Bi2O3-AlF3 glass doped with Eu3+, Tb3+ and Tm3+ ions
    • Karolina Milewska
    • Michał Maciejewski
    • Marcin Łapiński
    • Anna Synak
    • Mirosław Behrendt
    • Wojciech Sadowski
    • Barbara Kościelska
    2023 JOURNAL OF NON-CRYSTALLINE SOLIDS

    The B2O3-Bi2O3-AlF3 glass system doped with Eu3+, Tb3+, Tm3+ and triply doped with Eu3+/Tm3+/Tb3+ ions in different molar ratios were successfully synthesized. Glass transition and crystallization temperatures were examined by Differential Scanning Calorimetry (DSC) measurements. X-ray Diffraction (XRD) confirmed the amorphous character of the samples. Fourier Transform Infrared Spectroscopy (FTIR) revealed that the glass matrix consists of [BO3] and [BO4] structural units, while X-ray Photoelectron Spectroscopy (XPS) confirmed the presence of AlF3. An increase in luminescence spectra intensity was detected by Photoluminescence Spectroscopy (Pl), due to the presence of 10 mol% of AlF3. The RE3+ ions embedded in the glass matrix can be simultaneously excited by a single UV light. According to the CIE results the emitted color can be tunable by varying the excitation wavelength and sample composition. The presented results confirm that the proposed glass system could be a candidate for color-tunable phosphors in LEDs.

  • Structural insights, biocatalytic characteristics, and application prospects of lignin-modifying enzymes for sustainable biotechnology
    • Anil Kumar Singh
    • Hafiz M N Iqbal
    • Nunzio Cardullo
    • Vera Muccilli
    • Jesús Fernández-Lucas
    • Jens Ejbye Schmidt
    • Teofil Jesionowski
    • Muhammad Bilal
    2023 Full text INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES

    Lignin modifying enzymes (LMEs) have gained widespread recognition in depolymerization of lignin polymers by oxidative cleavage. LMEs are a robust class of biocatalysts that include lignin peroxidase (LiP), manganese peroxidase (MnP), versatile peroxidase (VP), laccase (LAC), and dye-decolorizing peroxidase (DyP). Members of the LMEs family act on phenolic, non-phenolic substrates and have been widely researched for valorization of lignin, oxidative cleavage of xenobiotics and phenolics. LMEs implementation in the biotechnological and industrial sectors has sparked significant attention, although its potential future applications remain underexploited. To understand the mechanism of LMEs in sustainable pollution mitigation, several studies have been undertaken to assess the feasibility of LMEs in correlating to diverse pollutants for binding and intermolecular interactions at the molecular level. However, further investigation is required to fully comprehend the underlying mechanism. In this review we presented the key structural and functional features of LMEs, including the computational aspects, as well as the advanced applications in biotechnology and industrial research. Furthermore, concluding remarks and a look ahead, the use of LMEs coupled with computational framework, built upon artificial intelligence (AI) and machine learning (ML), has been emphasized as a recent milestone in environmental research.

  • Structural, optical and electrochemical performance of black phosphorus and black arsenic-phosphorus nanostructures
    • Łukasz Macewicz
    2023 Full text

    Black phosphorus (BP)-based nanostructures have drawn a lot of attention due to their tunable bandgap and extraordinary properties such as: high surface-to-volume ratio, large number of active sites, and prominent edges. However, low dimensional structures of black phosphorus oxidize easily, which hamper their application on a broader scale. One way to overcome these difficulties is to modify the black phosphorus structure by substituting some of the phosphorus atoms for arsenic atoms, forming black arsenic-phosphorus (b-AsP). Despite the broad variety of atomically thin, two-dimensional materials, those with a bandgap range between 0.3 and 1.5 eV are plainly missing. Black phosphorus and black arsenic-phosphorus nanostructures not only correspond to the visible and infrared spectral range, but also possess additional tuning capabilities, which can further influence their electronic properties. In this dissertation, the structural and optical properties of BP and b-AsP nanoflakes and nanoribbons have been investigated. Moreover, surface modification of electrode materials with BP and b-AsP to enhance their electrochemical performance and sensing possibilities was investigated. The electrode materials chosen for BP and b-AsP modification were titania nanotubes (TiO2NTs), commercially available gold array electrodes, and CVD-fabricated polycrystalline boron-doped diamond (BDD) films.

  • Structural, physicochemical and anticancer study of Zn complexes with pyridyl-based thiazolyl-hydrazones
    • Jovana B. Araškov
    • Natalia Maciejewska
    • Mateusz Olszewski
    • Aleksandar Višnjevac
    • Vladimir Blagojević
    • Henrique S. Fernandes
    • Sérgio F. Sousa
    • Adrián Puerta
    • José M. Padrón
    • Berta Barta Holló
    • Miguel Monge
    • María Rodríguez-castillo
    • José M. López-de-luzuriaga
    • Özlem Uğuz
    • Atıf Koca
    • Tamara R. Todorović
    • Nenad R. Filipovići
    2023 JOURNAL OF MOLECULAR STRUCTURE

    Thiazolyl-hydrazones (THs) exhibit a wide spectrum of biological activity that can be enhanced by complexation with various metal ions. Zn(II) complexes with α-pyridine-1,3-TH ligands may represent an alternative to the standard platinum-based chemotherapeutics. In addition, they show photoluminescence properties and thus can be regarded as multifunctional materials. In this study, we synthesized and characterized three neutral Zn(II) complexes (1–3) with pyridine-based TH ligands HLS1‒3 in order to investigate the influence of the ligands charge on the structure and intermolecular interactions in the solid state, and consequently photophysical properties. The deprotonation of the ligands mainly affects the relative energies of electronic levels in the complexes, compared to cationic counterparts, resulting in similar photoluminescence mechanisms and quantum yields with a small shift in emission energy. The influence of the substitution at the ligands’ periphery on the selected quantum molecular descriptors of the complexes is localized to the substitution site. Also, the substituents did not considerably influence the redox responses of the complexes. However, predominant spectral changes were observed in the course of the first reduction and oxidation processes which caused distinct spectral colour changes indicating their possible functionality for electrochromic applications. In addition, complex 1 showed antiproliferative activity with GI50 values below 2 µM on all tested cancer cell lines.

  • Structurally well-defined functionalized polyolefins and graft copolymers thereof as bitumen modifiers
    • Mateusz Malus
    • Joanna Bojda
    • Maciej Sienkiewicz
    • Miloud Bouyahyi
    • Lanti Yang
    • Javier Francisco Navarro
    • Maria Soliman
    • Rob Duchateau
    • Lidia Jasińska-Walc
    2023 CONSTRUCTION AND BUILDING MATERIALS

    Here we demonstrate the application of hydroxyl-functionalized propylene-based copolymers, poly(propylene-co-1-hexene-co-10-undecen-1-ol) (FPP) and poly(styrene-co-maleic anhydride) (SMA) graft copolymers derived thereof, poly(propylene-co-1- hexene-graft-styrene-co-maleic anhydride) (FPP-g-SMA) as bitumen modifiers. The FPP samples were synthesized via solution copolymerization, while FPP-g-SMA products were obtained via transesterification of FPP with SMA either in solution or by a melt-grafting process. FPP-g-SMA modifiers prepared in solution, having a SMA content of around 30 wt.%, performed very well as compatibilizer for bitumen, generating a polymer-modified compositions with a uniform morphology and improved nanomechanical properties, storage stability, rheological properties and high- temperature performance as compared to neat bitumen samples.

  • Structure redetermination, transport and thermal properties of the YNi3Al9 compound
    • Ihor Oshchapovskyy
    • Ebube E. Oyeka
    • Thao Tran
    • Tomasz Klimczuk
    • Michał Winiarski
    2023 Full text JOURNAL OF SOLID STATE CHEMISTRY

    Single crystals of completely ordered variant of the YNi3Al9 compound were grown by self-flux method with excess of aluminum. The crystal structure of the title compound was redetermined from single crystal X-ray diffraction data. The structure adopts ErNi3Al9 type, space group R32, parameters of the unit cell a ​= ​7.2838(2) Å, c ​= ​27.4004(8) Å. The growth of relatively large single crystals of the YNi3Al9 compound, having completely ordered structure, indicates possible existence of region on phase diagram, where the title compound is in equilibrium with liquid. Comparison with the results in the literature on the investigations of the same and related compounds shows trend towards formation of more ordered structures in flux grown samples and more disordered ones in arc melted samples. Physical properties of the title compound - electrical resistivity, magnetoresistance and heat capacity - were measured for the first time. It shows metallic-like behavior with very high values of magnetoresistance up to 420% at low temperatures without presence of magnetic elements. Therefore electronic structure calculations were carried out. The phonon heat capacity reveals major Debye and minor Einstein contributions at the intermediate temperatures, and total heat capacity approaches Dulong-Petit limit at high temperatures. The calculated Debye temperature from the whole temperature range θD ​= ​480(6) K is typical for aluminium-rich compounds. Corresponding Einstein temperature is θE ​= ​198(8) K. The estimations of electron-phonon coupling constant λ ​= ​0.092 show very weak coupling and absence of superconducting transition.

  • Structured deformation of granular material in the state of active earth pressure
    • Leśniewska Danuta
    • A. Tordesillas
    • Magdale Pietrzak
    • Shuo Zhou
    • Michał Nitka
    2023 COMPUTERS AND GEOTECHNICS

    The paper focuses on the ability of granular materials to undergo structured deformation by analysing the data from the retaining wall model tests and discrete element simulations. The structured deformation means the movement of a granular material which produces a stable, regular pattern of multiple shear bands. The paper's primary purpose is to study this kind of deformation for the selected data representing the state of active earth pressure of granular materials. The locations of high and negligible shear strains (shear zones and 'dead' zones) in the displacement fields are determined using the shear strains definition. A recently introduced metric called s-LID, expressing the perspective of collective grain motion, is applied to the same data. The s-LID analysis finds the detailed structure of the localisation pattern directly from displacement data without using the continuum mechanics concept of strains. It is entirely consistent with the digital image correlation analysis in the areas of significant displacement. It expands the knowledge of the deformation structure in small displacement areas, where the digital image correlation method loses its capability. Low s-LID and point-like representations in the displacement state space identify nearly rigid zones in the area of high displacements.

  • Structure-Property Relationship and Multiple Processing Studies of Novel Bio-Based Thermoplastic Polyurethane Elastomers
    • Joanna Smorawska
    • Marcin Włoch
    • Ewa Głowińska
    2023 Full text Materials

    Currently, the growing demand for polymeric materials has led to an increased need to develop effective recycling methods. This study focuses on the multiple processing of bio-based thermoplastic polyurethane elastomers (bio-TPUs) as a sustainable approach for polymeric waste management through mechanical recycling. The main objective is to investigate the influence of two reprocessing cycles on selected properties of bio-TPUs. Two series of bio-based TPUs were synthesized via a solvent-free two-step method with the use of hexamethylene diisocyanate or hexamethylene diisocyanate/partially bio-based diisocyanate mixtures, bio-based poly(triamethylene ether) glycol, and bio-based 1,3 propanediol. Both the raw bio-TPUs and those subjected to two reprocessing cycles were examined with respect to their chemical, physical, thermal, thermomechanical, and mechanical properties. The conducted research revealed that reprocessing led to changes in the phase separation between the hard and soft segments, thereby affecting the bio-TPUs’ properties. Both series of materials showed similar chemical structures regardless of reprocessing (slight changes were observed in the range of carbonyl peak). The thermal properties of TPUs exhibited slight differences after each reprocessing cycle, but generally, the non-processed and reprocessed bio-TPUs were thermally stable up to about 300 °C. However, significant differences were observed in their mechanical properties. The tensile strength increased to 34% for the twice-reprocessed bio-TPUs, while the elongation at break increased by ca. 200%. On the other hand, the processing cycles resulted in a decrease in the hardness of both bio-TPU series (ca. 3–4 °ShA). As a result, the prepared bio-TPUs exhibited characteristics that were closer to those of the sustainable materials model, promoting the circular economy of plastics, with environmental benefits arising from their recyclability and their high content of bio-based monomers (78.4–78.8 wt.%).

  • Study of Soil Temperature and Moisture Changes in a Physical Model of an Underground Cable Line
    • Stanisław Czapp
    • Filip Ratkowski
    • Seweryn Szultka
    • Krzysztof Szuchnik
    • Michał Kołtun
    2023

    The ampacity of power cables is highly dependent on the thermal resistivity of the soil in which they are laid. The lower it is, the higher this ampacity. The thermal resistivity of the soil decreases as its moisture increases. Therefore, it is preferable that the soil around the cables has high moisture. Unfortunately, the heat generated in heavily loaded cables causes the migration of moisture from the surrounding soil, which adversely affects the ampacity of these cables. However, it turns out that it is possible to stop the migration of moisture from the immediate vicinity of the cables. The paper presents the results of a long-term experiment (soil/betonite temperature and moisture measurements), which proves that proper protection of the medium around the cables makes it possible to stop the migration of moisture. This has a positive effect on the ampacity of the cables and, thus, on the level of transmitted power.

  • Study of various machine learning approaches for Sentinel-2 derived bathymetry
    • Andrzej Chybicki
    • Paweł Sosnowski
    • Marek Kulawiak
    • Tomasz Bieliński
    • Waldemar Korlub
    • Zbigniew Łubniewski
    • Magdalena Kempa
    • Jarosław Parzuchowski
    2023 Full text PLOS ONE

    In recent years precise and up-to-date information regarding seabed depth has become more and more important for companies and institutions that operate on coastlines. While direct, in-situ measurements are performed regularly, they are expensive, time-consuming and impractical to be performed in short time intervals. At the same time, an ever-increasing amount of satellite imaging data becomes available. With these images, it became possible to develop bathymetry estimation algorithms that can predict seabed depth and utilize them systematically. Since there are a number of theoretical approaches, physical models, and empirical techniques to use satellite observations in order to estimate depth in the coastal zone, the presented article compares the performance and precision of the most common one to modern machine learning algorithms. More specifically, the models based on shallow neural networks, decision trees and Random Forest algorithms have been proposed, investigated and confronted with the performance of pure analytical models. The particular proposed machine learning models differ also in a set of satellite data bands used as an input as well as in applying or not geographical weighting in the learning process. The obtained results point towards the best performance of the regression tree algorithm that incorporated as inputs information about data localization, raw reflectance data from four satellite data bands and a quotient of logarithms of B2 and B3 bands. The study for the paper was performed in relatively optically difficult and spatially variant conditions of the south Baltic coastline starting at Szczecin, Poland on the west (53˚26’17’’ N, 14˚32’32’’ E) to Hel peninsula (54˚43’04,3774’’ N 18˚37’56,9175’’ E). The reference bathymetry data was acquired from Polish Marine Administration. It was obtained through profile probing with single-beam sonar or direct in-situ probing.

  • Study of ZrS3-based field-effect transistors toward the understanding of the mechanisms of light-enhanced gas sensing by transition metal trichalcogenides
    • Katarzyna Drozdowska
    • Adil Rehman
    • Sergey Rumyantsev
    • Michelle Wurch
    • Ludwig Bartels
    • Alexander Balandin
    • Janusz Smulko
    • Grzegorz Cywiński
    2023 Full text Materials Today Communications

    Extending knowledge of the properties of low-dimensional van der Waals materials, including their reactivity to the ambiance, is important for developing innovative electronic and optoelectronic devices. Transition metal trichalcogenides with tunable optical band gaps and anisotropic conductivity are an emerging class among low- dimensional structures with the possibility of gate tunability and photoreactivity. These properties can be combined into light-enhanced field-effect transistor gas sensors. We demonstrated prototype zirconium trisulfide (ZrS3) sensors for nitrogen dioxide, ethanol, and acetone. Photoconductivity and photogating play a critical role in photoinduced gas sensing, with the dominance of the first for blue (470 nm) and green (515 nm) and the second one prevailing for red (700 nm) irradiations. Our results suggest that surface trap states lead both to trapping and scattering of the charge carriers in the channel. The gas detection is guided by charge transfer and modulation of the carrier mobility, resulting in distinct I-V characteristics for selected irradiation conditions.