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Gdańsk University of Technology

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  • An improved methodology for accelerated marine immersed corrosion testing of ship structural components
    • Krzysztof Wołoszyk
    • Emil Roch
    • Beata Zima
    • Yordan Garbatov
    2024 Ships and Offshore Structures

    Corrosion degradation is a prominent ageing mechanism in engineering structures (e.g. ships and offshore structures), leading to safety concerns and significant economic expenses. This study presents an improved methodology for indoor accelerated corrosion testing of structural components. The method involves controlling natural factors (oxygen saturation, temperature, salinity, and flow rate) to accelerate the corrosion in a controlled environment. The study uses small coupons, medium specimens, and stiffened plates made of steel with different thicknesses. Significant degradation acceleration was achieved compared to natural conditions (approx. twenty times faster). The mean corrosion equals 3.3 mm/year with a maximum 10% variation for different specimen sizes and thicknesses. A novel approach to account for the mass of corrosion products during periodical measurements was proposed and validated. The improved methodology offers an efficient and accurate way to simulate marine immersed corrosion, enabling further research on corrosion degradation behaviour and resistance in ship structures.

  • An improvement of body surface area formulas using the 3D scanning technique
    • Grzegorz Redlarski
    • Sławomir Kozieł
    • Marek Krawczuk
    • Janusz Siebert
    • Marek Tałałaj
    • Aleksander Pałkowski
    • Piotr Tojza
    • Zuzanna Cieślikowska
    • Leszek Litzbarski
    2024 Full text International Journal of Occupational Medicine and Environmental Health

    Objectives: Body surface area (BSA) is one of the major parameters used in several medical fields. However, there are concerns raised about its usefulness, mostly due to the ambiguity of its estimation. Material and Methods: Authors have conducted a voluntary study to investigate BSA distribution and estimation in a group of 179 adult people of various sex, age, and physique. Here, there is provided an extended analysis of the majority of known BSA formulas. Furthermore, it was supplement with a comparison with the authors' propositions of enhanced formulas coefficients for known formulas models as well as with new power models based on an increased number of anthropometric data. Results: Introduction of the enhanced formulas coefficients cause a reduction of at least 30.5% in mean absolute error and 21.1% in maximum error in comparison with their known counterparts. Conclusions: In the context of the analysis presented it can be stated that the development of a single universal body surface area formula, based on a small number of state variables, is not possible. Therefore, it is necessary and justified to search for new estimation models that allow for quick and accurate calculation of body surface area for the entire population, regardless of individual body variations. The new formulas presented are such an alternative, which achieves better results than the previously known methods. Int J Occup Med Environ Health 2024;37(2)

  • An Innovative Floating System with a Savonius Rotor as a Horizontal-Axis Wind Turbine
    • Joanna Grzelak
    • Lara Guijarro Carrillo
    • Jacek Nakielski
    • Michał Piotrowicz
    • Krzysztof Doerffer
    2024 Full text Polish Maritime Research

    In this project, an innovative wind turbine was designed for a floating plant. A large Savonius rotor was replaced with a double-rotor wind turbine implemented as a horizontal-axis turbine. This double rotor was positioned on the tip of a thrust plate and fixed to the deck of a catamaran. Simple 2D numerical simulations were performed to confirm the effectiveness of the concept. An analysis of the floating system configuration was carried out, and the loads and stresses on the system components were verified. Next, floating supports with appropriate sizes were selected to counteract the forces on the wind turbine system. Finally, an anchoring system with full rotational freedom was selected for the f loating platform. The present work was conducted as part of a Master’s thesis.

  • An Innovative New Approach to Light Pollution Measurement by Drone
    • Katarzyna Bobkowska
    • Paweł Burdziakowski
    • Paweł Tysiąc
    • Mariusz Pulas
    2024 Drones

    The study of light pollution is a relatively new and specific field of measurement. The current literature is dominated by articles that describe the use of ground and satellite data as a source of information on light pollution. However, there is a need to study the phenomenon on a microscale, i.e., locally within small locations such as housing estates, parks, buildings, or even inside buildings. Therefore, there is an important need to measure light pollution at a lower level, at the low level of the skyline. In this paper, the authors present a new drone design for light pollution measurement. A completely new original design for an unmanned platform for light pollution measurement is presented, which is adapted to mount custom sensors (not originally designed to be mounted on a unmanned aerial vehicles) allowing registration in the nadir and zenith directions. The application and use of traditional photometric sensors in the new configuration, such as the spectrometer and the sky quality meter (SQM), is presented. A multispectral camera for nighttime measurements, a calibrated visible-light camera, is used. The results of the unmanned aerial vehicle (UAV) are generated products that allow the visualisation of multimodal photometric data together with the presence of a geographic coordinate system. This paper also presents the results from field experiments during which the light spectrum is measured with the installed sensors. As the results show, measurements at night, especially with multispectral cameras, allow the assessment of the spectrum emitted by street lamps, while the measurement of the sky quality depends on the flight height only up to a 10 m above ground level.

  • An intelligent cellular automaton scheme for modelling forest fires
    • Joan Boters Pitarch
    • María Signes-Pont
    • Julian Szymański
    • Higinio Mora-Mora
    2024 Full text Ecological Informatics

    Forest fires have devastating consequences for the environment, the economy and human lives. Understanding their dynamics is therefore crucial for planning the resources allocated to combat them effectively. In a world where the incidence of such phenomena is increasing every year, the demand for efficient and accurate computational models is becoming increasingly necessary. In this study, we perform a revision of an initial proposal which consists of a two-dimensional propagation model based on cellular automata (2D-CA), which aims to understand the dynamics of these phenomena. We identify the key theoretical weaknesses and propose improvements to address these limitations. We also assess the effectiveness and accuracy of the model by evaluating improvements using real forest fire data (Beneixama, Alicante 2019). Moreover, as a result of the theoretical modifications performed, we introduce a novel intelligent architecture that seeks to capture relationships between system cells from the data. This new architecture has the ability to advance our understanding of forest fire dynamics, contributing to both the evaluation of existing protocols and more efficient firefighting resource management.

  • An inverse algorithm for contact heat conduction problems with an interfacial heat source based on a first-order thermocouple model
    • Oleksii Nosko
    2024 Full text INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER

    Inverse problems of contact heat conduction with an interfacial heat source are common in various fields of science, engineering and technology. In this study, an algorithm for their solution is developed based on an inverse parametric optimisation method with an impulse response function describing the heat partition and contact heat transfer. A first-order thermocouple model with a time constant parameter is embedded in the impulse response function. The specific power of the heat source is sought in the form of a polynomial from the condition of least-squares deviation of the simulated temperature from the temperature samples obtained by a thermocouple. Compared to the classical methods of simple inverse convolution and sequential function specification, the algorithm proves to be accurate in a substantially larger region of variation of the heating duration and time constant, covering slow-response thermocouple measurements. Additionally, the algorithm is significantly more robust against noise with a sufficient number of temperature samples. The applicability of the algorithm is demonstrated by solving inverse problems of contact heat conduction typical for sliding friction, laser and electric resistance welding at different thermal contact conditions and ratios of the time constant to the heating duration.

  • An objective isogeometric mixed finite element formulation for nonlinear elastodynamic beams with incompatible warping strains
    • Myung-Jin Choi
    • Sven Klinkel
    • S. Klarmann
    • Roger Sauer
    2024 MULTIBODY SYSTEM DYNAMICS

    We present a stable mixed isogeometric finite element formulation for geometrically and materially nonlinear beams in transient elastodynamics, where a Cosserat beam formulation with extensible directors is used. The extensible directors yield a linear configuration space incorporating constant in-plane cross-sectional strains. Higher-order (incompatible) strains are introduced to correct stiffness, whose additional degrees of freedom are eliminated by an element-wise condensation. Further, the present discretization of the initial director field leads to the objectivity of approximated strain measures, regardless of the degree of basis functions. For physical stress resultants and strains, we employ a global patch-wise approximation using B-spline basis functions, whose higher-order continuity enables using much fewer degrees of freedom than an element-wise approximation. For time-stepping, we employ implicit energy–momentum consistent scheme, which exhibits superior numerical stability in comparison to standard trapezoidal and mid-point rules. Several numerical examples are presented to verify the present method.

  • An Open Platform Tool for 2D Multipactor Simulations in Metallic Microwave Components
    • Tomasz Nałęcz
    • Łukasz Nowicki
    • Małgorzata Celuch
    • Michał Baranowski
    • Adam Lamęcki
    • Michał Mrozowski
    2024 Full text

    The paper presents a computer simulation software aimed at assessing the multipactor threshold power in a rectangular waveguide working with single tone excitation. Initial tests demonstrate a strong agreement between the simulation results obtained and those from commercial software. Contrary to the existing commercial software, our tool will be provided as Open Platform, for free use and popularisation of knowledge about physical phenomena resulting from interactions of microwaves with materials.

  • An optimized dissolved oxygen concentration control in SBR with the use of adaptive and predictive control schemes
    • Tomasz Zubowicz
    • Tomasz Ujazdowski
    • Zuzanna Klawikowska
    • Robert Piotrowski
    2024 Full text

    This paper addresses the problem of optimizing control of the aeration process in a water resource recovery facility (WRRF) using sequencing batch reactor (SBR), one that affects the efficiency of wastewater treatment by stimulating metabolic reactions of microorganisms through dissolved oxygen (DO) level control, and accounts for the predominant part of operating costs. Two independent approaches to DO control algorithm design based on nonlinear model-based predictive control (NMPC) with constraints and direct model reference adaptive control (DMRAC) are proposed and compared. Both algorithms were developed on the basis of utility models obtained by cognitive model simplification, however, both algorithms are characterized by a distinct mechanism to achieve control optimality and incorporate uncertainty. The NMPCbased algorithm solves an online optimization task by reducing the impact of uncertainty through feedback and estimating its influence by evaluating the differences between the internal model and measurements on a sliding prediction window. In contrast, DMRAC reduces the impact of uncertainty through the adaptation of control law parameters. Meanwhile, optimality is encoded in the reference model parameters reflecting the operation of the closed-loop system and in the independent parameters of the adaptation mechanism. Illustrations of the algorithms’ operation were provided by simulation experiments using a three-layer SBR model of the Swarzewo wastewater treatment plant with ASM3e-based reactions.

  • An Optimized Ka-Band Low Profile Dual-Polarized Transmitarray Antenna With 2D Beam Switching
    • Seyed Hashem Ramazannia Tuloti
    • Adam Lamęcki
    • Michał Mrozowski
    2024 Full text IEEE Access

    This article presents an optimized dual-polarized transmitarray antenna (TA) designed for MIMO applications at the Ka-band, capable of switching beams in two directions. The antenna aperture uses a small unit cell with three layers of Taconic RF-35 dielectric substrates, which can be easily fabricated using PCB technology. The unit cell achieved a 360-degree phase shift and a transmission magnitude exceeding –0.4 dB at 28 GHz. We used nine dual-polarized patch antennas in a cross shape, each with a 10.5 dBi gain at 28 GHz, to switch the beams in two directions without changing the feed location. We optimized the phase distribution in the TA aperture and adjusted the feed antenna’s F/D and tilt to achieve a high-gain antenna with low-gain roll-off during beam switching. The fabricated TA exhibited excellent agreement with the full-wave simulation results. It achieved ±15 degrees and ±30 degrees beam tilts in the x- and y- directions, with less than 0.8 dB gain roll-off for both polarizations

  • An optimized system for sensor ontology meta-matching using swarm intelligent algorithm
    • Abdul Lateef Haroon P S
    • Sujata N. Patil
    • Parameshachari Bidare Divakarachari
    • Przemysław Falkowski-Gilski
    • M. D. Rafeeq
    2024 Internet Technology Letters

    It is beneficial to annotate sensor data with distinct sensor ontologies in order to facilitate interoperability among different sensor systems. However, for this interoperability to be possible, comparable sensor ontologies are required since it is essential to make meaningful links between relevant sensor data. Swarm Intelligent Algorithms (SIAs), namely the Beetle Swarm Optimisation Algorithm (BSO), present a possible answer to ontology matching problems. This research focuses on a method for optimizing ontology alignment that employs BSO. A novel method for effectively controlling memory use and striking a balance between algorithm exploration and exploitation is proposed: the Simulated Annealing-based Beetle Swarm Optimisation Algorithm (SA-BSO). Utilizing Gray code for solution encoding, two compact operators for exploitation and exploration, and Probability Vectors (PVs) for swarming choosing exploitation and exploration, SA-BSO combines simulated annealing with the beetle search process. Through inter-swarm communication in every generation, SA-BSO improves search efficiency in addressing sensor ontology matching. Three pairs of real sensor ontologies and the Conference track were used in the study to assess SA-BSO's efficacy. Statistics show that SA-BSO-based ontology matching successfully aligns sensor ontologies and other general ontologies, particularly in conference planning scenarios.

  • An Overview of Sport and the Future Smart Cities
    • Aleksander Orłowski
    • Narek Parsamyan
    2024

    One of the main challenges for future cities is to strengthen the role of people and their activities. Therefore, sport provides an opportunity to engage in physical activity, connecting citizens to the city. The question of how sport influences the development of cities and the concept of future smart cities arises. The aim of this study is to examine the relationship between sport and the concept of smart cities by identifying sport factors in the literature. The article highlights different areas of influence of sport on the smart city concept through specific examples of the contribution of sport to urban development and the well-being of citizens. The study states that the consideration of sport in the context of smart cities is relevant and multidimensional, since sport is a factor for the development of city solutions using in “hard” projects such as infrastructural and technological ones, and “soft” projects relating to improving social inclusion and healthcare. Including sport as a building component of the smart city concept is a new perspective of city governance, which is so far rarely discussed and, therefore, important. Sport has a broad influence on the social, technological, and environmental evolution of cities, therefore, sport appears to be a relevant factor that should contribute to the debate on future city agendas. The research delivers the links between sport and smart cities, which is important for further scientific considerations on the insights of smart city, and explores the subject of the influence of sport on the evolution of cities of tomorrow.

  • AN UPDATED FRAMEWORK FOR DIMENSIONING SAFE PARAMETERS OF INLAND WATERWAYS ADOPTING FUZZY LOGIC
    • Ievgen Medvediev
    • Dmitriy Muzylyov
    • Jakub Montewka
    2024 Full text

    Recently established guidelines by World Association for Waterborne Transport Infrastructure (PIANC) for designing the dimensions of the inland waterway, offer a methodology for determining safe width of inland waterways based on a concept of safety and ease of navigation. Therein a wide set of external and internal factors of various origin (organizational, technical, related to human) known to affect the safety and ease (S&E) of navigation are accounted for. Based on their anticipated effect, either positive or negative on S&E the labels are assigned to each factor, aggregated, and resulting effect is determined. Based on the effect, the width of the waterway is estimated. The anticipated effect of each factor is expressed in a binary manner, where the factor may improve or deteriorate the S&E of navigation, however, the magnitude of this influence is not accounted for, which we found as the main gap in knowledge. Therefore, in this paper, we introduce an updated framework for determining the S&E of navigation by improving the existing model structure and its parameters through the application of fuzzy logic. The latter is employed since waterways in each region are characterized by a specific set of factors, and some of them are difficult to quantify unambiguously. The information required to feed the updated model was collected through a survey employing a group of experts comprising inland ship captains, and engineers, with at least 3 years of work experience. The proposed concretization of the influence of factors on the resulting assessment will improve the design of the dimensions of the inland waterway. Such result assessment is the main advantage of the updated framework compared to the current PIANC management. The existing vague binary S&E estimate of inland waterways is transformed to specific values by the updated framework. The initial evaluation range [-1; + 1] remains unchanged. It is possible by approximating the incoming values of the vaguely quantified parameters into a concretized intermediate estimate value due to fuzzy logic. Therefore, the updated framework enhances this particular PIANC guidelines.

  • Analiza czasochłonności docierania jednotarczowego powierzchni płaskich elementów ceramicznych - studium przypadku
    • Adam Barylski
    2024

    Przedstawiono analizę czasochłonności docierania elementów ceramicznych. Badano czasochłonność obróbki na dwóch docierarkach jednotarczowych o znacząco różniących się średnicach tarcz docierających. Porównano czasy jednostkowe docierania elementów płaskich z ceramiki technicznej Al2O3

  • Analiza doświadczalna wpływu długości zakotwienia pręta na zachowanie przyczepności w teście pull-out
    • Marcin Burdziński
    • Maciej Niedostatkiewicz
    2024 Full text Inżynieria i Budownictwo

    Artykuł prezentuje badania przyczepności przeprowadzone przy użyciu testu pull-out. Eksperymenty miały na celu ocenę wpływu długości zakotwienia na przyczepność w tym teście. Z przeprowadzonej analizy wynika, że długość styku pręt-beton znacząco wpływa na zachowanie przyczepności. Określa ona typ zniszczenia połączenia, wpływa na rozkład i wartość naprężeń w pręcie oraz rzutuje na przebieg krzywej przyczepność-poślizg, która jest kluczowym rezultatem testu pull-out.

  • Analiza numeryczna wpływu długości zakotwienia pręta na zachowanie przyczepności w teście pull-out
    • Marcin Burdziński
    • Maciej Niedostatkiewicz
    2024

    Artykuł przedstawia symulacje numeryczne testu pull-out przeprowadzone w programie ABAQUS. Celem analizy była ocena wpływu długości zakotwienia pręta żebrowanego na przyczepność. Interakcję pręta z betonem odwzorowano za pomocą kohezyjnej powierzchni kontaktu, wykorzystując skalibrowane krzywe zależności przyczepność-poślizg, otrzymane z badań własnych. W obliczeniach numerycznych wykorzystano parametry mechaniczne betonu i stali wykorzystanych w eksperymentach. Analiza wykazała istotny wpływ długości zakotwienia na zachowanie przyczepności. Wyniki symulacji numerycznych charakteryzują się wysoką zbieżnością z rezultatami eksperymentów, m.in. pod względem krzywej przyczepność-poślizg czy pracy materiałów.

  • Analiza numeryczna wpływu długości zakotwienia pręta na zachowanie przyczepności w teście pull-out
    • Marcin Burdziński
    • Maciej Niedostatkiewicz
    2024 Full text Inżynieria i Budownictwo

    W artykule przedstawiono symulacje numeryczne testu pull-out w programie ABAQUS. Symulacje miały na celu ocenienie wpływu długości zakotwienia pręta żebrowanego na przyczepność w tym teście, opierając się na wynikach przeprowadzonych eksperymentów. Interakcję pręta z betonem odwzorowano za pomocą kohezyjnej powierzchni kontaktu, wykorzystując skalibrowane krzywe przyczepność-poślizg, otrzymane z doświadczeń wykonanych w ramach badań własnych. Do zdefiniowania modeli materiałowych użyto parametrów mechanicznych betonu i stali wykorzystanych w testach. Przeprowadzona analiza wykazała, że długość zakotwienia znacząco wpływa na zachowanie przyczepności. Rezultaty symulacji numerycznych charakteryzują się dużą zbieżnością z badaniami laboratoryjnymi, zarówno pod kątem krzywej przyczepność-poślizg, jak i pracy materiałów.

  • Analiza połączenia ciesielskiegotypu rounded dovetail connection
    • Krzysztof Ryncewicz
    • Marcin Szczepański
    • Dominika Habyk
    • Jakub Marchewka
    • Aleksandra Raszkowska
    2024 Full text Builder

    The advancing technology of numerically controlled machines for woodworking has contributed to the development of new types of carpentry joints. One such example is the rounded dovetail connection (RDC). Due to its advantages, such as aes thetics and ease of assembly, this solution can serve as an alternative to commonly used fittings and carpentry joints. However, there is a lack of data on the tensile strength of this connection in the literature, normative documents, and design guidelines. This paper presents the state of knowledge, describes the research setup, and presents the results of tests conducted on samples made of solid structural timber connected with wedge joints on a real scale. Based on the accepted criteria, the tensile strength was assessed and compared with the densities of the individual samples. The results indicated that this connection exhibits a certain tensile strength. The study served as a preliminary step for further analyses related to attempts to strengthen the connection using full-threaded self taping screws.

  • ANALIZA POSTACI SYGNAŁU SYNCHRONIZACYJNEGO NPSS W NB-IOT
    • Olga Błaszkiewicz
    • Jarosław Sadowski
    • Piotr Rajchowski
    2024 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    W artykule zaprezentowane zostały możliwości zmiany postaci sekwencji Zadoff-Chu używanej do wygenerowania sygnału synchronizacyjnego NPSS w interfejsie radiowym NB-IoT. Modyfikacji poddano elementy charakterystyczne sekwencji z uwzględnieniem: root index, ciągu binarnego czy składnika funkcji wykładniczej w celu poprawy właściwości korelacyjnych na potrzeby synchronizacji pracy terminali użytkowników.

  • Analiza stateczności skarpy klifu w ciągubrzegu morskiego w miejscowości Rozewie
    • Witold Tisler
    • Wiktoria Pałasz
    • Tomasz Pierzchliński
    • Natalia Piórkowska
    • Kacper Szulc
    2024 Builder

    W opracowaniu przedstawiono wariantową analizę stateczności wykonaną dla klifu znajdującego się w miejscowości Rozewie. Na zboczu z uwagi na gęstą roślinność oraz wysokie nachylenie zachodzą procesy osuwiskowe i wymaga ono wzmocnienia. W porównaniu przeprowadzonych analiz szczególną uwagę zwrócono na sposób modelowania poziomu wody gruntowej oraz wartości parametrów przyjmowanych dla modelu van Genuchtena, odpowiedzialnego za analizę przepływu w strefie nienasyconej.

  • Analiza techniczno-ekonomiczna zastosowania systemu magazynowania energii zasilanego z instalacji fotowoltaicznej
    • Blanka Jakubowska
    • Aleksandra Sierdzińska
    2024 Rynek Energii

    W artykule dokonano oceny celowości implementacji magazynu energii do instalacji fotowoltaicznej o mocy zainstalowanej 39,3 kW. W analizowanym przypadku prąd produkowany jest na potrzeby gospodarstwa sadowniczego oraz mieszkańców domu jednorodzinnego. Analiza, oparta na realnych danych rocznej eksploatacji systemu fotowoltaicznego, uwzględnia ilość wyprodukowanej energii nadwyżki energii przekazywanej do sieci i z niej pobieranej. Zebrane dane umożliwiły odpowiedni dobór pojemności akumulatorów. W ramach prowadzonej analizy określono ilość energii jaka możliwa jest do zmagazynowania, liczbę cykli pracy, koszty eksploatacyjne i inwestycyjne oraz koszt zaoszczędzonej energii. Przeprowadzona analiza opiera się na dwóch wariantach, wykorzystujących technologie baterii litowo-jonowych i kwasowo-ołowiowych.

  • ANALYSIS AND OPTIMIZATION OF ELECTRIC VEHICLE CHARGING PROCESSES IN TRANSACTIVE ENERGY SYSTEMS
    • Halyna Bielokha
    • Ryszard Strzelecki
    • Denys Derevianko
    • Ihor Radysh
    2024 Full text POWER ENGINEERING

    The implementation of smart charging of electric vehicles allows operators of local power networks and electricity suppliers to implement new business models for the interaction of electric vehicles with the network. In addition to the optimal selection of Microgrid capacities when charging electric vehicles, it is also important to use different charging methods. To satisfy the interests of all participants of local systems from an economic and technical point of view, the concept of transactional energy was chosen. The effect of different charge management methods on EV battery efficiency, such as two-stage charging (CC-CV), accelerated charging (AC) and alternative multi-level MSCC charging, has been investigated. The optimization of charging processes aims not only to increase the profit from the sale of electricity, but also to minimize charging costs by means of an optimal flow of electricity from the network to the car. The proposed objective function depends on the generation capacity of all sources included in the system, the state of charge of the storage systems, the time of day, the charging time of electric vehicles, the charging speed, and the price of electricity. The control system, solving the objective function, itself chooses and offers the consumer and the aggregator a charging method that, given the system parameters, will be optimal for all participants of the transactional system. Three charge methods were investigated by digital simulation for four different types of electric vehicles, all considered charge methods have high energy efficiency indicators that can be used as control methods for charging electric vehicles from local systems

  • Analysis of cyclone separator solutions depending on spray ejector condenser conditions
    • Milad Amiri
    • Paweł Ziółkowski
    • Jaroslaw Mikielewicz
    • Michał Klugmann
    • Dariusz Mikielewicz
    2024 APPLIED THERMAL ENGINEERING

    The core design strategy for minimizing CO2 emissions in gas power plant entails combining a spray ejector condenser (SEC) and separator to accomplish steam condensation and CO2 purification. This innovative process involves direct-contact condensation of steam with CO2, facilitated by interaction with a subcooled water spray, along with a cyclone separator mechanism intended for generating pure CO2. The investigation of the SEC section, both experimentally and analytically, provides crucial insights into its operational dynamics. Given the susceptibility of cyclone efficiency to fluctuations in SEC conditions, this research endeavors to examine the impacts of CO2 volumetric flow rate and droplet break-up within the SEC on the separation efficacy of the cyclone separator. Additionally, the impact of cone size on the performance of the cyclone has been investigated. Here, a three-dimensional, transient, and turbulent cyclone separator is numerically simulated using Ansys Fluent 2021 R1. The Reynolds Stress Model is employed to simulate turbulent flow, while a mixture model is utilized to replicate swirl two-phase flow within the separators. The findings revealed that reductions in steam and CO2 flow rates were associated with a decrease in outlet temperature but an increase in SEC inlet temperature, leading to a rise in temperature difference and heat transfer rate. Furthermore, an augmentation in cyclone cone size (from 0.2 to 0.5 m) resulted in enhanced separation efficiency (from 77.30% to 80.98%) alongside an elevation in pressure drop (from 6.08 Pa to 10.91 Pa), suggesting a compromise between CO2 purification and energy consumption. Additionally, elevated CO2 flow rates induced a rise in pressure drop and separation efficiency, ultimately achieving maximum efficiency at a rate of 24 g/s. Moreover, the exploration into droplet breakup manifesting in a boost in separation efficiency from 50.98% to 100% across droplet diameters ranging from 1 to 20 μm.

  • Analysis of Drone Signals Based on Change Point Detection Algorithm
    • Grzegorz Fotyga
    • Bartosz Bossy
    • Paweł Żukowski
    • Aleksander Nowak
    2024 Full text

    The work presents an algorithm characterized by high precision and efficiency in identifying signals related to data transmission between the controller and the drone. Using an efficient change point detection algorithm and parallel analysis capabilities, this method facilitates rapid signal analysis. These features make the proposed algorithm a solid basis for developing an effective anti-drone defense system.

  • Analysis of dynamics of a map-based neuron model via Lorenz maps
    • Piotr Bartłomiejczyk
    • Frank Llovera Trujillo
    • Justyna Signerska-Rynkowska
    2024 Full text CHAOS

    Modeling nerve cells can facilitate formulating hypotheses about their real behavior and improve understanding of their functioning. In this paper, we study a discrete neuron model introduced by Courbage et al. [Chaos 17, 043109 (2007)], where the originally piecewise linear function defining voltage dynamics is replaced by a cubic polynomial, with an additional parameter responsible for varying the slope. Showing that on a large subset of the multidimensional parameter space, the return map of the voltage dynamics is an expanding Lorenz map, we analyze both chaotic and periodic behavior of the system and describe the complexity of spiking patterns fired by a neuron. This is achieved by using and extending some results from the theory of Lorenz-like and expanding Lorenz mappings.

  • Analysis of Ferroresonance Mitigation Effectiveness in Auxiliary Power Systems of High-Voltage Substations
    • Rafał Tarko
    • Wiesław Nowak
    • Jakub Gajdzica
    • Stanisław Czapp
    2024 Full text ENERGIES

    Ferroresonance in power networks is a dangerous phenomenon, which may result in overcurrents and overvoltages, causing damage to power equipment and the faulty operation of protection systems. For this reason, the possibility of the occurrence of ferroresonance has to be identified, and adequate methods need to be incorporated to eliminate or reduce its effects. The aim of this paper is to evaluate the effectiveness of ferroresonance damping in auxiliary power systems of high-voltage substations by selected damping devices. Laboratory experiments, the results of which created bases for the development of models of selected damping devices, are presented. These models were used to simulate the effectiveness of ferroresonance damping in an auxiliary power system of a 220/110 kV substation in the EMTP-ATP program. The analyses showed that control systems with different algorithms of operation are used in damping devices. This knowledge is important when selecting parameters and settings of the applied damping devices for a given network and the disturbances in it. The presented research results have proved the effectiveness of commercially available damping devices, provided their parameters are correctly coordinated with the settings of the power system protection.

  • Analysis of friction ridge evidence for trace amounts of paracetamol in various pharmaceutical industries by Raman spectroscopy
    • Martyna Czarnomska
    • Aneta Lewkowicz
    • Mattia Pierpaoli
    • Emilia Gruszczyńska
    • Magdalena Kasprzak
    • Zygmunt Gryczyński
    • Piotr Bojarski
    • Sławomir Steinborn
    • Krzysztof Woźniewski
    2024 Full text JOURNAL OF FORENSIC SCIENCES

    The detection of potentially harmful substances presents a multifaceted challenge. On one hand, it can directly save lives, on the other, it can significantly aid and enhance police work, thereby increasing the effectiveness of investigations. The research conducted in this study primarily aims to identify paracetamol in fingerprints, considering situations involving direct contact of a person with paracetamol either chronically or in a single dose. The identification procedure presented, utilizing Raman spectroscopy, aims to rapidly detect the xenobiotic following ingestion by an individual, which involves touching the tablet with their fingers—this can be termed as touch evidence in forensic science investigations. Additionally, the authors focus on assessing the impact of additives present in drugs containing paracetamol as the main active ingredient. The screening results obtained will enable us to analyze the composition of drugs in terms of potentially toxic substances, and their influence on the physicochemical activity of the active substance. We successfully identified the paracetamol molecule using a noninvasive forensic trace detection method. Samples in the form of common drugs containing 500 mg of paracetamol were studied. Throughout the study, comprehensive validation of the method was ensured through the utilization of a statistical model, which excluded sensitivity to the presence of other substances, whether additives or from the external environment. The proposed approach to trace the content of substances in fingerprint using Raman scattering analysis provides a useful starting point to enhance current analytical methods not only in forensic science but also in toxicology.

  • Analysis of observability and detectability for CSTR model of biochemical processes under uncertain system dynamics and various sets of measured outputs
    • Rafał Łangowski
    • Mateusz Czyżniewski
    2024 Full text Archives of Control Sciences

    An analysis of observability and detectability for continuous stirred tank reactor model of selected biochemical processes has been addressed in this paper. In particular, properties of observability or detectability of the considered system model have been proved under uncertain system dynamics in view of various sets of system measured outputs. It is related to considering system dynamics depending on initial conditions and the impact of inputs taking into account a given measured output. The method of indistinguishable state trajectories (indistinguishable dynamics) and tools based on the Lyapunov second method were used to investigate the observability and detectability properties. The analysis was performed for eight cases of different sets of measured outputs with association to the realistic features of measuring devices. The obtained research results are essential for system state estimation that involves the synthesis of state observers. The proposed approach may be successfully applied to the complex biochemical non-linear uncertain systems modelled as continuous stirred tank reactors.

  • Analysis of regulations regarding transport of dangerous goods by road in Poland and in Europe
    • Bartłomiej Kobus
    • Joanna Wachnicka
    2024 Full text Przegląd Komunikacyjny

    The subject of the article are regulations regarding transport of hazardous materials in road transportation. In Poland, as well as in most European countries, these regulations are mainly governed by the ADR Agreement, which is a supra-national legal act. The article contains an analysis of the mentioned legal act. Despite the fact that the ADR Agreement harmonizes regulations concerning the transport of hazardous materials, there are domestic standards that diff er slightly from the provisions of this agreement. The article also describes parking facilities for vehicles carrying hazardous materials in Poland and presents statistical data regarding parking spaces for this type of vehicles.

  • Analysis of Roughness, the Material Removal Rate, and the Acoustic Emission Signal Obtained in Flat Grinding Processes
    • Piotr Sender
    • Irene Buj - Corral
    • Jesús Álvarez-Flórez
    2024 Full text Machines

    In this work, the analysis of the acoustic emission (AE) signal in grinding processes is addressed. The proposed analysis method decomposes the acoustic signal into three frequency ranges. The total energy of each range is determined, as well as the highest frequency. Different grinding experiments were carried out, according to a full factorial design of experiments (DOE), in which feed speed, depth of cut, and transversal step (table cross feed) were varied. Arithmetic average roughness Ra and the material removal rate (MRR) were determined. It was observed that Ra depends mainly on the transversal step, followed by feed speed and the interaction between the transversal step and depth of cut, while MRR is greatly influenced by the transversal step. According to multi-objective optimization with the Derringer–Suich function, in order to simultaneously minimize Ra and maximize MRR, a transversal step of 9 mm per longitudinal pass, feed speed of 20 m/min, and depth of cut of 0.020 mm should be selected.

  • ANALYSIS OF TEMPERATURE DISTRIBUTIONS IN A GERMICIDAL CHAM-BER SUPPORTED BY LIGHT-ILLUMINATED GOLD NANORODS USING CFD-EQUATIONS AND A THERMAL CAMERA
    • Piotr Radomski
    • Dominik Kreft
    • Maria Nevarez Martinez
    • Aimad Koulali
    • Iuliia Mukha
    • Luciano De Sio
    • Paweł Ziółkowski
    • Dariusz Mikielewicz
    2024 Full text

    Since the COVID-19 pandemic, protection against pathogenic germs and surface disinfection have become critical issues. Most effective bacteria/virus inactivation methods are either power-consuming or require using caustic chemical substances. Herein, thermal inactivation appears to be an affordable and effective technique as long as high temperatures are reached quickly and long-termly maintained. Therefore, the preparation of a chamber that accomplishes this purpose has been envisioned, designed and manufactured, allowing significant germ inactivation and offering an effective tool for water purification stations. In this regard, this work proposes applying 16-16-65-nm laser-illuminated gold nanorods (AuNRs) as a non-standard heat source, which can produce the generated heat inside a considered volume. Consequently, the locations of AuNRs deposited on glass platforms, stuck on the internal or external chamber’s walls, from two sides, were investigated to intensify the heat transfer processes upon the entire chamber. To verify the efficiency of the energy conversion from light to heat, spectroscopy techniques and laser power meters were used. Similarly, temperature fields at the illuminated platforms were solved using the Computational Fluid Dynamics (CFD) equations and two different theoretical models which adopt the Rayleigh approximation and consider the delivered heat flux with a fixed efficiency, respectively. The considered Models were verified using a calibrated and highly-resolved thermal camera. Upon 900-mW 808-nm laser illumination for 50 min, the temperature of the platforms increased by οܶ ൎ ͷ͹ǤͳԨ and οܶ ൎ ͵ͺͺǤ͵Ԩ for an unfocused and focused beam, respectively. However, the quickest heat diffusion process is visible when the AuNR platform is situated in the internal position of the chamber, offering οܶ ൎ ͵ͻǤͶԨ after 50 min of illumination.

  • Analysis of the influence of geometrical imperfections on the equivalent load stabilizing roof truss with lateral bracing system
    • Marcin Krajewski
    2024 Full text Journal of Theoretical and Applied Mechanics

    The paper is focused on the numerical analysis of the stability and load bearing capacity of a flat steel truss. The structure was supported by elastic lateral braces. The translational and rotational brace stiffness was taken into account. The linear buckling analysis were performed for the beam and shell model of the truss. The nonlinear static analysis were conducted for the structure initial geometric imperfections. As a result the buckling load and the limit load depended on brace stiffness was obtained. The reactions in elastic braces were compared to the stabilizing forces calculated on the basis of actual code requirements.

  • Analysis of the relationship between cutting forces and local structural properties of Scots pine wood aided by computed tomography
    • Yunbo Huang
    • Daniel Chuchała
    • Dietrich Buck
    • Kazimierz Orłowski
    • Magnus Fredriksson
    • Mikael Svensson
    2024 Full text INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY

    X-ray computed tomography (CT) is utilised in some sawmills today, primarily for enhancing value yield and for process automation, which includes log sorting and sawing optimisation. Nevertheless, there is a scarcity of recent research utilising CT to assess the local cutting process. As a preliminary study, this paper addresses this gap by using CT to investigate the connections between local cutting force and local wood properties including density, knots, and annual ring width. Workpieces of Scots pine (Pinus sylvestris L.), from Sweden and Poland, were CT-scanned in laboratory conditions. Quasi-linear cutting tests were then performed on both clear and knotty regions of the workpieces using a custom-made laboratory stand with a Stellite-tipped tooth mounted on piezoelectric sensors. It was found that density infuences cutting forces for both clear and knotty wood, and this efect increased noticeably with increasing uncut chip thickness. Changes in wood density, such as between sapwood and heartwood or between clear wood and knot, caused dynamic changes in cutting forces and temporary disturbances to the stability of the system. Normalisation of cutting forces by local density allowed the conclusion that density is not the only property afecting cutting forces. Other structural properties, e.g. annual ring width and latewood–earlywood proportion may afect the cutting process as well, which requires deeper analysis in the future research. This preliminary study demonstrates the feasibility and usefulness of coupling CT data with cutting force measurements and suggests further research on the relationship between cutting force and wood properties.

  • ANALYSIS OF UNCONTROLLED WEAR IN THE AREA OFA BELLEVILLE SPRING OF A FRICTION TORSIONAL VIBRATIONDAMPER IN A MOTOR VEHICLE CLUTCH
    • Michał Formela
    • Jacek Łubiński
    2024 TRIBOLOGIA

    The article describes the problem of excessive tribological wear of a torsional vibration damper built into a single-disc friction clutch of a truck vehicle. In contrast to the controlled, design-based wear of damper’s friction rings, i.e., wear whose kinetics are known and predictable, uncontrolled wear at Belleville spring contact surfaces effects in a premature decrease in the damper’s friction torque and, consequently, loss of durability. As a result of the analyses and experimental work, the causes of accelerated wear were identified. Sets of springs and friction rings from the 10 used vibration dampers that worked under similar operating conditions but with different operating periods were used as the basic research material. The influence of abrasive wear of Belleville springs on their load-deflection characteristic was identified. A comparative analysis of the characteristics of the new spring and the used springs is also presented to illustrate changes in the axial load in the assemblies of the analyzed dampers.

  • Analytical progress on emerging pollutants in the environment: An overview of the topics
    • Jezrzy Falandysz
    • Guorui Liu
    • Małgorzata Rutkowska
    2024 TRAC-TRENDS IN ANALYTICAL CHEMISTRY

    This overview discusses the ideas behind a collection of articles by invited authors on a diverse range of complex chemical mixtures and analytical methods which represent some of the most relevant and interesting issues on emerging contaminants of environmental health concerns. These chemicals, including those in high volume production, are released on an ongoing basis as a result of various human activities. Moreover, these emerging contaminants are highly toxic to humans and ubiquitous in the environment. The terms “environmental pollution" and “food web contaminant" became widely known from the first decades of the XX century and as a historical background, they have an early link to the agricultural use of mercury fungicides and DDT. Surprisingly for chemists and society, the 1960s saw the emergence of the global problem of environmental and food contamination with polychlorinated biphenyls (PCBs). The environmental science paradigm has lost none of its importance in the meantime, although it has evolved to encompass a vast number of environmentally hazardous chemicals, many of which are termed as “emerging". To put it simply, air-water-soil/sediment are the first compartments affected and become reservoirs or sinks for environmental pollutants, the next is the food web, topped by the top animal predators and humans. Understanding the occurrence, environmental fate and biotoxicity of emerging contaminants is of interest to many areas of science.

  • Analyzing the relationship between sound, color, and emotion based on subjective and machine-learning approaches
    • Jelizaveta Kurilčik
    • Mateusz Połom
    • Marcin Jankowski
    • Olga Kozłowska
    • Aleksandra Łabich
    • Edyta Skiba
    • Patryk Spierewka
    • Paweł Śliwiński
    • Bożena Kostek
    2024 Full text

    The aim of the research is to analyze the relationship between sound, color, and emotion. For this purpose, a survey application was prepared, enabling the assignment of a color to a given speaker’s/singer’s voice recordings. Subjective tests were then conducted, enabling the respondents to assign colors to voice/singing samples. In addition, a database of voice/singing recordings of people speaking in a natural way and with expressed emotion was prepared, where discrete colors were assigned in subjective tests. These data were used in a machine-learning approach that consisted in searching for the relationship between sound, color, and emotion. Analyses based on correlational analysis and learning algorithms were performed. It occurred that assigning values of naturally sounding and emotionally charged speech/singing parameters to colors (and their parameters) did not enable finding a correlation between the given voice, emotions, and color features. The machine learning model achieved high accuracy in the relation between the generated colors and the colors corresponding to the emotions in the literature and questionnaire results.

  • Angels drawing a picture JAPAN | INTERNATIONAL EXHIBITION
    • Agnieszka Kurkowska
    • Paulina Duch-Żebrowska
    • Marta Koperska-Kośmicka
    2024

    Polskie dziedzictwo reprezentowane w pracach młodych uczestników z Polski dzięki powołaniu RWYC Poland i aktywnej działalności na polu edukacji powszechnej. Konkursy realizowane były jesienią 2023 roku w ramach międzynarodowego projektu pod auspicjami UNESCO – Reconnecting WIth Your Culture POLAND. W Japonii odbyły się 4 wystawy z udziałem prac uczestników z całego świata, w tym wybranych przez RWYC Poland. Lokalizacje wystaw japońskich: 2023 rok: Machida City Museum of Graphic Arts w Tokyo, 2024 rok: Koganei Miyajigakki Hole Citizens Gallery w Tokyo, Mitaka City Arts Centerw Tokyo, Sapporo Citizens Gallery w Sapporo. https://www.youtube.com/watch?v=cxn_TRmLxJw

  • Angiopoietin-like growth factor-derived peptides as biological activators of adipose-derived mesenchymal stromal cells
    • Adriana Schumacher
    • Piotr Mucha
    • Izabela Puchalska
    • Milena Deptula
    • Anna Wardowska
    • Agata Tymińska
    • Natalia Filipowicz
    • Alina Mieczkowska
    • Paweł Sachadyn
    • Arkadiusz Piotrowski
    • Michał Pikuła
    • Miroslawa Cichorek
    2024 Full text BIOMEDICINE & PHARMACOTHERAPY

    Adipose-derived mesenchymal stromal cells (AD-MSCs) are an essential issue in modern medicine. Extensive preclinical and clinical studies have shown that mesenchymal stromal/stem cells, including AD-MSCs, have specific properties (ability to differentiate into other cells, recruitment to the site of injury) of particular importance in the regenerative process. Ongoing research aims to elucidate factors supporting AD-MSC culture and differentiation in vitro. Angiopoietin-like proteins (ANGPTLs), known for their pleiotropic effects in lipid and glucose metabolism, may play a significant role in this context. Regeneration is a complex and dynamic process controlled by many factors. ANGPTL6 (Angiopoietin-related growth factor, AGF), among many activities modulated the biological activity of stem cells. This study examined the influence of synthesized AGF-derived peptides, designated as AGF9 and AGF27, on AD-MSCs. AGF9 and AGF27 enhanced the viability and migration of AD-MSCs and acted as a chemotactic factor for these cells. AGF9 stimulated chondrogenesis and lipid synthesis during AD-MSCs differentiation, influenced AD-MSCs cytokine secretion and modulated transcriptome for such basic cell activities as migration, transport of molecules, and apoptosis. The ability of AGF9 to modulate the biological activity of AD-MSCs warrants the consideration of this peptide a noteworthy therapeutic agent that deserves further investigation for applications in regenerative medicine.

  • Anisotropic magnetism of polymorphic ErAl3
    • Karolina Górnicka
    • Brenden R. Ortiz
    • Andrew D. Christianson
    • Andrew F. May
    2024 Physical Review Materials

    ErAl3 can form in either a trigonal () or cubic () polymorph and this paper investigates the physical properties of these polymorphs through characterizations of single crystals grown in an aluminum flux. We demonstrate that polymorph selection can be achieved based on the nominal composition of the crystal growth. Magnetic measurements confirm that both −ErAl3 and −ErAl3 order antiferromagnetically at low temperatures. −ErAl3 undergoes antiferromagnetic ordering at a Néel temperature =5.1K, and the transition is suppressed continually with applied field. −ErAl3 displays more complex behavior, with successive magnetic transitions at =5.7K and 2=4.6K for zero field, where heat capacity and dilatometry measurements evidence that these transitions are second and first order, respectively. Under magnetic field, strong anisotropy is revealed in −ErAl3, with several steplike metamagnetic transitions observed below 2 for ∥c. These transitions produce sequential magnetization plateaus near one-half of the apparent saturation magnetization. The electrical resistivity of −ErAl3 is strongly coupled to its magnetism. At =2K, we observe a positive magnetoresistance reaching 60%, with distinct anomalies at the metamagnetic transitions. The results are summarized in − phase diagrams that demonstrate complex magnetic behavior for −ErAl3, suggesting an important role of competing interactions in this metallic system that possesses characteristics of Ising physics.

  • Anisotropic, multiband, and strong-coupling superconductivity of the Pb0.64Bi0.36 alloy
    • Sylwia Gutowska
    • Karolina Górnicka
    • Paweł Wójcik
    • Tomasz Klimczuk
    • Bartłomiej Wiendlocha
    2024 PHYSICAL REVIEW B

    This paper presents theoretical and experimental studies on the superconductivity of Pb0.64Bi0.36 alloy, which is a prototype of strongly coupled superconductors and exhibits one of the strongest coupling under ambient pressure among the materials studied so far. The critical temperature, the specific heat in the superconducting state, and the magnetic critical fields are experimentally determined. Deviations from the single-gap s-wave BCSlike behavior are observed. The electronic structure, phonons, and electron-phonon interactions are analyzed in relation to the metallic Pb, explaining why the Pb-Bi alloy exhibits such a large value of the electron-phonon coupling parameter λ 2. Superconductivity is studied using the isotropic Eliashberg formalism as well as the anisotropic density functional theory for superconductors. We find that while Pb is a two-gap superconductor with well-defined separate superconducting gaps, in the Pb-Bi alloy an overlapped three-gap-like structure is formed with a strong anisotropy. Furthermore, the chemical disorder, inherent to this alloy, leads to strong electron scattering, which is found to reduce the critical temperature.

  • Anisotropy and compaction gradient assessment on rammed earth specimens through sonic tomography approach
    • J.d. Rodríguez-Mariscal
    • Monika Zielińska
    • Magdalena Rucka
    • M. Solís
    2024 Full text ENGINEERING STRUCTURES

    Rammed earth is a traditional construction technique that has recently gained attention because of its benefits from an ecological perspective. The conservation of the existing valuable cultural heritage sites and the quality control of new constructions built with this material require the development and application of practical inspection techniques. This paper explores the application of sonic tests and sonic tomography as practical tools for monitoring the state of conservation of existing structures and the identification of heterogeneities or damaged areas. Two groups of 6 rammed earth specimens were manufactured and tested. The manufacturing process of each group allowed the application of compression loads and the identification of the Sonic Wave Propagation Velocities along directions parallel and perpendicular to the compaction forces during manufacturing. The SWPV were identified for the different paths between 9 measuring points located at two opposite sides of the specimens, leading to up to 6 different planes for each specimen. The SWPV are identified by identifying the Time-of-Flight of the elastic wave between each pair of excitation and receiver points. A discretized coloured map of the SWPV distribution for each plane defined by the measurement points array is obtained by the application of an algorithm already developed by the authors to obtain tomographic images for other materials and applications. The SWPV are identified after 2 different increasing values of a uniform compressive load is applied to each specimen. The results show that the analysis of the SWPV and tomographic images is sensitive to heterogeneities, such as compaction gradients from the manufacturing process, and also to the accumulated damage in the solid. The paper demonstrates that the proposed technique can be potentially used for a qualitative inspection of the state of conservation of specific rammed earth constructions.

  • Anode Materials for Sodium-Ion Battery
    • Magdalena Graczyk-Zajac
    • Alexander Kempf
    • Monika Wilamowska-Zawłocka
    2024

    There is an urgent need to develop a highly efficient, low-cost alternative to the now-ubiquitous lithium-ion batteries (LIBs). A cheaper and less resource-critical sodium-ion battery (NIB) technology has recently gained much attention. Thus, there is also continuous research ongoing on stable, high-capacity anode materials for NIBs. Dependent on the mechanism of the electrochemical reaction, the negative electrode materials can be classified into three groups: insertion-based electrodes, alloy-based materials and conversion-type materials. Insertion compounds include soft and hard carbons as well as titanium-based oxides. The alloy-forming materials are represented by individual elements from group 14 and group 15, with Sn, Sb and P being the most prominent examples. The reaction within conversion-type materials involves the formation of new phases during sodiation that are usually structurally very different from the starting material. Transition metal oxides (Fe, Cu, and Ni) have been considered in this context due to their intrinsic stability and relative abundancy. The huge interest in the 2D materials gave rise to the layered chalcogenides, graphene, phosphorene and MX-enes as potential negative electrodes for NIBs. These classes of compounds will be described in this chapter considering their composition, structure, electrochemical performance, sustainability and cost.

  • Anomaly Detection in Railway Sensor Data Environments: State-of-the-Art Methods and Empirical Performance Evaluation
    • Michał Bałdyga
    • Kacper Barański
    • Jakub Belter
    • Mateusz Kalinowski
    • Paweł Weichbroth
    2024 Full text SENSORS

    To date, significant progress has been made in the field of railway anomaly detection using technologies such as real-time data analytics, the Internet of Things, and machine learning. As technology continues to evolve, the ability to detect and respond to anomalies in railway systems is once again in the spotlight. However, railway anomaly detection faces challenges related to the vast infrastructure, dynamic conditions, aging infrastructure, and adverse environmental conditions on the one hand, and the scale, complexity, and critical safety implications of railway systems on the other. Our study is underpinned by the three objectives. Specifically, we aim to identify time series anomaly detection methods applied to railway sensor device data, recognize the advantages and disadvantages of these methods, and evaluate their effectiveness. To address the research objectives, the first part of the study involved a systematic literature review and a series of controlled experiments. In the case of the former, we adopted well-established guidelines to structure and visualize the review. In the second part, we investigated the effectiveness of selected machine learning methods. To evaluate the predictive performance of each method, a five-fold cross-validation approach was applied to ensure the highest accuracy and generality. Based on the calculated accuracy, the results show that the top three methods are CatBoost (96%), Random Forest (91%), and XGBoost (90%), whereas the lowest accuracy is observed for One-Class Support Vector Machines (48%), Local Outlier Factor (53%), and Isolation Forest (55%). As the industry moves toward a zero-defect paradigm on a global scale, ongoing research efforts are focused on improving existing methods and developing new ones that contribute to the safety and quality of rail transportation. In this sense, there are at least four avenues for future research worth considering: testing richer data sets, hyperparameter optimization, and implementing other methods not included in the current study.

  • Antenna Optimization Using Machine Learning with Reduced-Dimensionality Surrogates
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    • Leifur Leifsson
    2024 Full text Scientific Reports

    In modern times, antenna design has become more demanding than ever. The escalating requirements for performance and functionality drive the development of intricately structured antennas, where parameters must be meticulously adjusted to achieve peak performance. Often, global adjustments to geometry are necessary for optimal results. However, direct manipulation of antenna responses evaluated with full-wave electromagnetic (EM) simulation models using conventional nature-inspired methods entails significant computational costs. Alternatively, surrogate-based techniques show promise but are impeded by dimensionality-related challenges and nonlinearity of antenna outputs. This study introduces an innovative technique for swiftly optimizing antennas. It leverages a machine learning framework with an infill criterion employing predicted enhancement of the merit function, utilizing a particle swarm optimizer as the primary search engine, and employs kriging for constructing the underlying surrogate model. The surrogate model operates within a reduced-dimensionality domain, guided by directions corresponding to maximum antenna response variability identified through fast global sensitivity analysis, tailored explicitly for domain determination. Operating within this reduced domain enables building dependable metamodels at a significantly lower computational cost. To address accuracy loss resulting from dimensionality reduction, the global optimization phase is supplemented by local sensitivity-based parameter adjustment. Extensive comparative experiments involving various planar antennas demonstrate the competitive operation of the presented technique over machine learning algorithms operating in full-dimensionality space and direct EM-driven bio-inspired optimization techniques.

  • Anti-cancer management of head and neck cancers and oral microbiome—what can we clinically obtain?
    • Jakub Makarewicz
    • Karolina Kaźmierczak-Siedlecka
    • Bartosz Kamil Sobocki
    • Iwona T. Dobrucki
    • Leszek Kalinowski
    • Ewa Stachowska
    2024 Full text FRONTIERS IN CELLULAR AND INFECTION MICROBIOLOGY

    Head and neck squamous cell carcinoma (HNSCC) exhibits significant genetic heterogeneity and primarily concerns the oral cavity and oropharynx. These cancers occur more frequently in men with a 5-year survival rate below 50%. Major risk factors include human papilloma virus (HPV) (notably type 16), Epstein–Barr virus, tobacco, alcohol, and poor oral hygiene with approximately 4.5% of global cancers linked to HPV. Notably, differences in the microbiome between healthy individuals and patients with head and neck cancers (HNCs) have been identified. Recent studies highlight the significance of certain oral microbes in risk assessment and the potential of the microbiome as a biomarker for HNCs. Additionally, role of the microbiome in metastasis has been acknowledged. Treatment for HNCs includes local methods, such as surgery and radiotherapy, and systemic approaches, such as immunotherapy. Numerous side effects accompany these treatments. Emerging research suggests the beneficial role of preoperative immunonutrition and probiotics in patient outcomes, emphasizing the influence of the microbiome on treatment efficacy. This review explores the reciprocal effects of HNC treatment and the gut microbiome using radiotherapy, brachytherapy, surgery, immunotherapy, and chemotherapy.

  • Anticancer Study on IrIII and RhIII Half-Sandwich Complexes with the Bipyridylsulfonamide Ligand
    • Mateusz Kowalik
    • Joanna Masternak
    • Mateusz Olszewski
    • Natalia Maciejewska
    • Katarzyna Kazimierczuk
    • Jerzy Sitkowski
    • Aleksandra Dąbrowska
    • Agnieszka Chylewska
    • Mariusz Makowski
    2024 INORGANIC CHEMISTRY

    Two non-platinum compounds, organometallic half-sandwich complexes [(η 5 -Cp)IrCl(L)]PF 6 (1) and [(η 5 -Cp)RhCl(L)]PF 6 (2) were prepared by treating pentamethylcyclopentadienyl chloride dimers of iridium(III) or rhodium(III) with the obtained 4-amino-N-(2,2'-bipyridin-5- yl)benzenesulfonamide ligand (L) and ammonium hexafluorophosphate. The crystal structures of ligand (L) and complexes 1 and 2 were obtained and then analyzed. Coordination reactions of the bipyridylsufonamide ligand (L) to the central ions were confirmed by UV- Vis, FT-IR, NMR ( 1 H, 13 C, and 15 N) spectroscopies, and stability study. Moreover, the interactions between the sulfaligand, Ir(III) and Rh(III) complexes with carbonic anhydrase (CA), human serum albumin (HSA) and also with CT-DNA have been investigated. Additionally, the reactivity of complexes toward GSH and NADH has been spectrophotometrically tested. A low affinity of complex 2 to GSH seems to be beneficial regarding its potential cytotoxic activity. The obtained compounds were then evaluated for their antiproliferative activity against four cancer cell lines from different origins: non-small cell lung cancer A549, colon cancer HCT-116, breast cancer MCF7, lymphoblastic leukemia Nalm-6, and a nonmalignant human embryonic kidney cell line HEK293. It has been observed that the iridium(III) complex (1) was found to exhibit a lack of antiproliferative properties against the tested cancer cell lines. The sulfonamide ligand (L) and the rhodium(III) complex (2) were studied in detail for colon cancer HCT-116 cell line, and the detailed biological analysis was reported and discussed.

  • Applicability of edible Candelilla wax composite blended with Bryophyllumpinnatum extract to prolong shelf life of fruits/vegetables
    • Amber Fatima
    • Fatima Tahir
    • Ayesha Mohyuddin
    • Tabassum Munir
    • Sohail Nadeem
    • Mohsin Javed
    • Mohd Hafiz Dzarfan Othman
    • Hui Hwang Goh
    • Hussein Al-Hazmi
    • Faissal Aziz
    • Abdelkader Anouzla
    • Tonni Agustiono Kurniawan
    2024 Journal of Food Measurement and Characterization

    Candelilla wax (CW) is a natural lipid source that can be used to make biodegradable and edible coatings and films for fruits. However, CW alone does not provide sufficient antimicrobial and antioxidant properties to prevent microbial spoilage and oxidative deterioration of fresh products. This study aims at evaluating the applicability of CW blended with Bryophyllum pinnatum extract (BPE), a plant with medicinal and phytochemical properties, to enhance the shelf life of fruits. CW and BPE were mixed at different ratios and applied as coatings on banana, cucumber, lemon, and apple. The coated fruits were stored at room temperature for several days and evaluated for weight loss (WL), pH, and physical appearance. The results showed that the edible CW coating mixed with B. pinnatum extract could extend the shelf-life of selected fruits by lowering their weight loss (WL), as compared to those without coating (p≤0.05; paired t-test). It was observed that % WL of banana was significantly higher in the control group than in the coated banana (p≤0.05; paired t-test) and that the highest WL (4.5%) was reached on the 4th day. The lowest WL (2.7%) was observed in the banana with edible coating with methanolic extract (ECME) formulation. The coating formed a complex layer that blocked the movement of H2O molecules through the selected fruits, preventing water loss. The smallest pH change was observed in the banana coated with the extract, indicating that the coating was suitable for extending the shell life of banana. Overall, CW enriched with BPE maintained the quality of their products for marketability.

  • Application of 3D scanning and computer simulation techniques to assess the shape accuracy of welded components
    • Marianna Jędrych
    • Damian Gorzkiewicz
    • Mariusz Deja
    • Marek Chodnicki
    2024 Full text INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY

    While traditional measurement methods prove to be insufficient when facing more complex shapes and intricate challenges, increasingly efficient solutions are emerging in their place. 3D scanners in particular exhibit versatility. They clearly represent a useful tool in many fields with diverse requirements; thus, it is advisable to explore further areas of their potential applications, e.g., in quality control or reverse engineering. During our research, measurements were carried out on 40 welded elements using a caliper and on 11 other elements using the HandySCAN 700 Elite device by Creaform. The research was conducted at different stages of production, between subsequent operations. In addition, in the absence of interoperative nominal dimensions, a welding process simulation was performed in the Simufact Welding software. The simulation results were compared with actual deformations measured using a 3D scanner. The research enabled identification of the causes of excessive deformations and provided the basis for comparing the caliper with a modern laser device. A particular advantage of the scanner was demonstrated for complex issues requiring high flexibility and precise documentation of full geometry. The caliper proved to be more efficient only for quick execution of single, simple measurements at specific places. Incorporating the simulation in the Simufact Welding software into the analysis, allowed for a more precise validation of the planned technology. This solution presents a promising alternative to nominal models, particularly valuable when measurements are conducted between subsequent operations. Further research in this area is also recommended to enhance proposed methodology

  • Application of commercial microwave links (CMLs) attenuation for quantitative estimation of precipitation
    • Magdalena Pasierb
    • Zofia Bałdysz
    • Jan Szturc
    • Grzegorz Nykiel
    • Anna Jurczyk
    • Katarzyna Ośródka
    • Mariusz Figurski
    • Marcin Wojtczak
    • Cezary Wojtkowski
    2024 Full text METEOROLOGICAL APPLICATIONS

    Precipitation estimation models are typically sourced by rain gauges, weather radars and satellite observations. A relatively new technique of precipitation estimation relies on the network of Commercial Microwave Links (CMLs) employed for cellular communication networks: the rain-inducted attenuation in the links enables the precipitation estimation. In the paper, it is analysed to what extent the precipitation derived from CML attenuation data is useful in estimation of the precipitation field with the high temporal and spatial resolution required in nowcasting models. Two methods of determination of precipitation along CMLs from attenuation of signal with several frequencies were proposed. Then, in order to generate precipitation field, three approaches for assigning appropriate precipitation values to a specific point or set of pixels along the link are developed and tested. The CML-based estimates are compared with point observations from manual rain gauges and multi-source precipitation fields using daily and half-hourly accumulations. It was found that the CML-based precipitation fields are much worse than radar-derived estimates. At the same time, they had slightly poorer reliability than spatially interpolated telemetric rain gauge data and significantly higher reliability than satellite estimates. Furthermore, the impact of link characteristics, such as length and frequency, on the reliability of CML-based precipitation estimates is analysed.

  • Application of Galvanostatic Non-Linear Impedance Spectroscopy to the Analysis of Metallic Material Degradation
    • Paweł Ślepski
    • Husnu Gerengi
    • Dominika Parasińska
    • Łukasz Gaweł
    2024 Materials

    This study presents a novel application of Non-Linear Electrochemical Impedance Spectroscopy (NLEIS) in galvanostatic mode for the rapid, non-destructive assessment of metal degradation. By using galvanostatic mode instead of traditional potentiostatic methods, polarization-related challenges are mitigated, enabling more accurate and reliable analysis. The technique allows for the determination of corrosion rates (corrosion current) and material susceptibility to oxidation (Tafel coefficient) through a single measurement with a modulated AC perturbation signal. Theoretical assumptions of the method were validated through tests on both a non-linear model system and an experimental system. The proposed research methodology is highly effective for monitoring the condition of metallic materials in various environments, covering both anodic and cathodic processes.