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Politechniki Gdańskiej

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  • Millimeter Wave Wideband and Low-Loss Compact Power Divider Based on Gap Waveguide: For Use in Wideband Antenna Array System
    • Arefeh Kalantari Khandani
    • Ali Farahbakhsh
    • Davood Zarifi
    • Ashraf Uz Zaman
    2024 Pełny tekst IEEE Access

    This paper presents a wideband and low-loss design of a compact power divider based on gap waveguide technology. The proposed power divider consists of two adjacent E-plane groove gap waveguide and a small ridge section to couple and equally divide the EM energy from the input E-plane groove gap waveguide to the two output ones in-phase. The simulation results show that the proposed waveguide power divider has about 40% impedance bandwidth while its size is 0.7λ×0.6λ at the center frequency. An 8-way power divider is designed using the proposed 2-way power divider and the back-to-back configuration of the 8-way one is fabricated to investigate the performance of the proposed design. In addition, to show the application of the presented power divider, a wideband linear horn antenna array is designed and fabricated. The measured results agree well with the simulated ones and prove the excellent low-loss and wide bandwidth of the proposed power divider over the band of interest from 50-75GHz. The measured S11 of the entire 8-way power divider remains below -10 dB level, the insertion loss is around 1 dB over the band of interest. Also, the S11 of the horn array integrated with the 8-way feed network remains below -10 dB and the low sidelobes of the radiation pattern of the entire horn array indicates excellent phase and amplitude balance for the power divider over the entire bandwidth of interest.

  • Miniaturization-Oriented Design of Spline-Parameterized UWB Antenna for In-Door Positioning Applications
    • Adrian Bekasiewicz
    • Tom Dhaene
    • Ivo Couckuyt
    • Jacek Litka
    2024

    Design of ultra-wideband antennas for in-door localization applications is a challenging task. It involves development of geometry that maintains appropriate balance between the size and performance. In this work, a topologically-flexible monopole has been generated using a stratified framework which embeds a gradient-based trust-region (TR) optimization algorithm in a meta-loop that gradually increases the structure dimensionality. The optimization has been performed using a composite objective function that maintains acceptable size/performance trade-off. The final design features a reflection below –10 dB within the UWB spectrum and a small footprint of only 182 mm2. The considered method has been benchmarked against a standard TR-based routine executed directly on a multi-dimensional electromagnetic model of the antenna.

  • Miniaturized Dual-Band Bandpass Filter with Wide Inter Stopband for 5G Applications
    • Earla Shankar
    • Kanaparthi Phani Kumar
    • Vamsi Krishna Velidi
    • Sławomir Kozieł
    2024 IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS

    This article presents the design of a miniaturized dual-band bandpass filter with a wide inter-stopband and improved isolation. A novel topology comprising the series connection of shunt cascaded coupled lines and quarter-wavelength open stubs is proposed to realize the dual-band filter along with half-wavelength stepped-impedance stubs. The circuit characteristics contain nine transmission zeros and four poles. The transmission zeros frequencies of the dual-band filter response have been theoretically verified using even-odd mode analysis. For experimental validation purposes, a dual-band filter with a center frequency ratio of 5.17 covering 5G applications (N12 & N48) has been implemented and fabricated using the microstrip technology. The full-wave simulated and measured filter responses are in good congruence.

  • Minikin’s equation mistake — a mystic art of systems of measuring units
    • Waldemar Magda
    2024 PROCEEDINGS OF THE INSTITUTION OF CIVIL ENGINEERS-MARITIME ENGINEERING

    This paper deals with one of the most controversial equations in coastal engineering — the so-called Minikin’s equation, describing the impact pressure due to wave breaking on a vertical-wall caisson of a composite breakwater. This equation has been used worldwide for many years, although it has been reported many times to overestimate real values of the impact pressure measured in nature and in the laboratory. Units of measurement, problems with dimensionality of parameters and conversion between different unit systems were suspected as causes. This paper explores in rigorous detail the reason behind the problems associated with Minikin’s equation. After a thorough literature review and a detailed analysis of all previously published forms of Minikin’s equation, a question of coherence/incoherence of systems of measuring units has been specially addressed. By adopting the incoherent English Engineering system of units, the most proper and satisfactory explanation of the curious mistake in Minikin’s formula has been found and formally correct forms of the equation, followed by appropriate units of measurement, are presented.

  • Minimization of a ship's magnetic signature under external field conditions using a multi-dipole model
    • Mirosław Wołoszyn
    • Jarosław Tarnawski
    2024 Pełny tekst Scientific Reports

    The paper addresses the innovative issue of minimizing the ship's magnetic signature under any external field conditions, i.e., for arbitrary values of ambient field modulus and magnetic inclination. Varying values of the external field, depending on the current geographical location, affect only the induced part of ship's magnetization. A practical problem in minimizing the ship signature is separating permanent magnetization from induced magnetization. When the ship position changes, a signature measurement has to be made under new magnetic field conditions to update the currents in the coils. This is impractical or even difficult to do (due to the need for a measuring ground), so there is a need to predict the ship's magnetization value in arbitrary geographical location conditions based on the reference signature determined on the measuring ground. In particular, the model predicting the signatures at a new geographical location must be able to separate the two types of magnetization, as permanent magnetization is independent of external conditions. In this paper, a FEM model of the vessel is first embedded in an external field and permanent magnetization is simulated using DC coils placed inside the model. Then, using the previously developed rules for data acquisition and determination of model parameters, a multi-dipole model is synthesized in which the induced and permanent parts are separated. The multi-dipole model thus developed has been successfully confronted with the initial model in FEM environment. The separation of permanent and induced magnetization allows the latter to be scaled according to new values of the external field. In the paper, the situation of determining a signature at one geographical position and its projection onto two other positions is analyzed. Having determined the signature with a high degree of accuracy anywhere in the world, it is possible to perform classical signature minimization by determining DC currents in coils placed inside the ship's hull. The paper also analyzes the effectiveness of ship's signature minimization and the influence of ship's course on the signature value. The advantage of the method presented in this paper is an integrated approach to the issue of scaling and minimization of ship magnetic signature, which has not been presented in the literature on such a scale before.

  • M-integral for finite anti-plane shear of a nonlinear elastic matrix with rigid inclusions
    • Victor Eremeev
    • Konstantin Naumenko
    2024 Pełny tekst INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE

    The path-independent M-integral plays an important role in analysis of solids with inhomogeneities. However, the available applications are almost limited to linear-elastic or physically non-linear power law type materials under the assumption of infinitesimal strains. In this paper we formulate the M-integral for a class of hyperelastic solids undergoing finite anti-plane shear deformation. As an application we consider the problem of rigid inclusions embedded in a Mooney–Rivlin matrix material. With the derived M-integral we compute weighted averages of the shear stress acting on the inclusion surface. Furthermore, we prove that a system of rigid inclusions can be replaced by one effective inclusion.

  • Missing Puzzle Pieces in Dementia Research: HCN Channels and Theta Oscillations
    • Paulina Kaźmierska-Grębowska
    • Maciej Jankowski
    • Bruce M. MacIver
    2024 Pełny tekst Aging and Disease

    Increasing evidence indicates a role of hyperpolarization activated cation (HCN) channels in controlling the resting membrane potential, pacemaker activity, memory formation, sleep, and arousal. Their disfunction may be associated with the development of epilepsy and age-related memory decline. Neuronal hyperexcitability involved in epileptogenesis and EEG desynchronization occur in the course of dementia in human Alzheimer’s Disease (AD) and animal models, nevertheless the underlying ionic and cellular mechanisms of these effects are not well understood. Some suggest that theta rhythms involved in memory formation could be used as a marker of memory disturbances in the course of neurogenerative diseases, including AD. This review focusses on the interplay between hyperpolarization HCN channels, theta oscillations, memory formation and their role(s) in dementias, including AD. While individually, each of these factors have been linked to each other with strong supportive evidence, we hope here to expand this linkage to a more inclusive picture. Thus, HCN channels could provide a molecular target for developing new therapeutic agents for preventing and/or treating dementia.

  • Mixed, quantum-classical description of electron density transfer in the collision process
    • Paweł Wojda
    • Marta Łabuda
    • Sergey Kshevetskii
    2024 MOLECULAR PHYSICS

    In this work, we investigate an ion-atom model describing the time-dependent evolution of electron density during the collision. For a S3+- H system, numerical simulations are based on classical trajectory calculations, and the electron density behaviour is described with the time-dependent Schrödinger equation. We apply the finite difference method to obtain quantitative insights into the charge transfer dynamics, providing detailed information about the spatial and temporal evolution of the collision process. The results are given for representative examples of the collision, from eV to keV range of energies, in head-on collision as well as for different values of impact parameter. A validity and precision of the proposed model and interpretation of the particle collision in terms of eigenstates are also discussed.

  • Mixed-use buildings as the basic unit that shapes the housing environment of smart cities of the future
    • Mateusz Gerigk
    2024 Środowisko Mieszkaniowe

    The contemporary approach to creating the residential function is confronted with the trend of increasing the volume of buildings and expectations regarding the future urban environment focused on sustainable development. This paper presents an overview of the residential structure in the context of defined thematic scopes. Namely, it is a systemic approach to the problem of designing mixed-use buildings which create a modern residential structure in developing urban centres. The creation of smart cities from existing urban areas and newly designed centres involves comprehensively defined design guidelines. The key is the integrity and interoperability of the dynamic structure which can serve as a basis for developing new systems and/or improving the existing ones. The developed model structure for creating and maintaining the system is based on a genetic algorithm and is presented in the form of a neural network that involves the use of artificial intelligence (AI). The specific structure is intended as a tool to support supervision and decision-making in the process of designing and managing contemporary mixed-use buildings in their newly planned surroundings.

  • MnWO4/reduced graphene oxide-based electrochemical sensing platform for simultaneous detection of catechol and resorcinol
    • Somayeh Tajik
    • Reza Zaimbashi
    • Fariba Garakani Nejad
    • Mohammad Taghi Tourchi Moghadam
    • Mohammad Bagher Askari
    • Hadi Beitollahi
    2024 DIAMOND AND RELATED MATERIALS

    n this study, a novel electrochemical sensor for accurate and sensitive catechol determination was demonstrated employing a screen-printed graphite electrode (SPGE) modified with MnWO4/reduced graphene oxide (MnWO4/rGO) nanocomposite. The MnWO4/rGO nanocomposite has been successfully prepared by using hydrothermal technique, and it was then characterized using several microscopic and spectroscopic methods (XRD, FE-SEM, and EDS). SPGE modified with MnWO4/rGO nanocomposite compared to the unmodified SPGE by creating a synergistic effect and having unique properties (large surface area of MnWO4 nanoparticles along with high electrical conductivity and large surface area of rGO sheets) by enhancing the speed of electron transfer and effective interaction of the analyte with the electrode surface, significantly improved the efficiency of electrochemical reactions and the catalytic effect for detection of catechol. The MnWO4/rGO/SPGE response was shown to be linear with the change in catechol concentration in the concentration range of 0.01–600.0 μM under optimal conditions, and the detection limit was 0.005 μM, utilizing the differential pulse voltammetry (DPV) technique. Moreover, as a means of simultaneous detection of catechol and resorcinol, the modified SPGE demonstrated good catalytic performance. These two analytes' oxidation peaks were completely separated, with an apparent peak potential difference of 380 mV, which made it possible to determine both of these chemicals simultaneously. Eventually, catechol and resorcinol were effectively detected in water samples with acceptable recovery values.

  • Mobilenet-V2 Enhanced Parkinson's Disease Prediction with Hybrid Data Integration
    • Sameer Ahmad Bhat
    • Piotr Szczuko
    2024 Pełny tekst

    This study investigates the role of deep learning models, particularly MobileNet-v2, in Parkinson's Disease (PD) detection through handwriting spiral analysis. Handwriting difficulties often signal early signs of PD, necessitating early detection tools due to potential impacts on patients' work capacities. The study utilizes a three-fold approach, including data augmentation, algorithm development for simulated PD image datasets, and the creation of a hybrid dataset. MobileNet-v2 is trained on these datasets, revealing higher generalization or prediction accuracy of 84% with hybrid datasets. Future research will explore the impact of high variability synthetic datasets on prediction accuracies and investigate the MobileNet-v2 architecture's memory footprint for timely inferences with low latency

  • Modal modification of structural damping applied to increase the stability and convergence of numerical integration
    • Krzysztof Lipiński
    2024

    The presented paper refers to numerical tests done on systems fused of multibody and finite-element parts. The appearance of its multibody part gives rise to significant nonlinear components, i.e., second-order nonlinear differential equations express the dynamics. We usually solve these equations by “step-by-step” integration methods. When using the currently available integration algorithms, we approximate these initial systems of equations by their associated sets of difference equations. The resulting approximated answers enclose superfluous solutions not related to the true one. Calculation that does not magnify these approximation errors is called numerically stable. The initial task is to find robust algorithms, i.e., such that do not produce extraordinarily different results for tiny changes in the initial data. We should underline that numerical instability is a phenomenon due to the employed numerical method but not due to the problem itself. We apply a modal modification of the damping matrix to eliminate these instabilities. The idea of modal modification is not a novelty. We should recall the modal reduction of system degrees of freedom as the example (suppression of its highest damped modes). With the Author's proposition, we do not eliminate these modes but reduce their damping to correlate them with the user-optimal time step. The highest damped modes of the resulting model diminish slower but still under the supposition of vanishing in a period lower than the assumed interval of the observations.

  • Model Management for Low-Computational-Budget Simulation-Based Optimization of Antenna Structures Using Nature-Inspired Algorithms
    • Anna Pietrenko-Dąbrowska
    • Sławomir Kozieł
    2024 APPLIED SOFT COMPUTING

    The primary objective of this study is investigation of the possibilities of accelerating nature-inspired optimization of antenna structures using multi-fidelity EM simulation models. The primary methodology developed to achieve acceleration is a model management scheme which the level of EM simulation fidelity using two criteria: the convergence status of the optimization algorithm, and relative quality of the individual designs within the solution pool. The search process is initiated using the lowest-fidelity (therefore, the fastest) EM model. The fidelity is step-by-step increased towards the conclusion of the process. At the same time, lower-quality designs are evaluated at lower resolution level as compared to the better ones. Our technique has been extensively validated using several microstrip antennas, and particle swarm optimization (PSO) algorithm as the search engine. The obtained results demonstrate that making the EM model fidelity dependent on just the convergence status of the algorithm allows for relative savings from forty to seventy percent, depending on the algorithm setup. At the same time, managing model fidelity as a function of both convergence status and relative design quality (within the population processed by the algorithm) allows for up to 85 percent savings, as compared to high-fidelity-based algorithms. Furthermore, the achieved acceleration is not detrimental to the optimization process reliability. Apart from the computational efficiency, the attractive feature of the proposed approach is implementation simplicity and versatility: the presented management scheme can be readily incorporated into most nature-inspired routines.

  • Model oceny dojrzałości przedsiębiorstw do zastosowania zwinnych metodyk zarządzania projektami IT
    • Piotr Zejer
    2024 Pełny tekst

    Dysertacja koncentruje się na budowie modelu, który ocenia gotowość przedsiębiorstw do wdrożenia zwinnych metodyk zarządzania projektami IT. Analizuje istniejące metody oceny dojrzałości projektowej i wprowadza własny model, biorąc pod uwagę krytyczne czynniki sukcesu i skuteczność zwinnych metod. Rozprawa zawiera badania literaturowe, empiryczne studium przypadku oraz weryfikację i rekomendacje modelu, dostarczając wglądu w praktyczne zastosowanie zwinnych metod zarządzania projektami w sektorze IT. Głównym celem modelu jest wskazanie uwarunkowań i obszarów funkcjonalnych przedsiębiorstwa, które wymagają poprawy dla skutecznego stosowania tych metod. Praca dostarcza praktycznego narzędzia dla organizacji, umożliwiającego ocenę ich dojrzałości w kontekście zwinnych praktyk zarządzania projektami, co ma kluczowe znaczenie dla sukcesu projektów IT w dynamicznie zmieniającym się środowisku biznesowym.

  • Model Pomorskiej Nagrody Jakości w świetle wyników badań opinii stron zainteresowanych
    • Anna Wendt
    • Piotr Grudowski
    2024 Problemy Jakości

    Cel - prezentacja oryginalnego modelu wykorzystywanego do oceny/samooceny organizacji w regionalnym konkursie o Pomorską Nagrodę Jakości na podstawie oceny dotychczasowych doświadczeń oraz badania opinii i potrzeb głównych interesariuszy tej inicjatywy. Podstawowym założeniem przy opracowaniu tego modelu jest jego dostosowanie do współczesnych trendów dotyczących doskonałości organizacyjnej oraz upowszechnienie jego stosowania jako obiektywnej podstawy ewaluacji skuteczności i efektywności organizacji prywatnych i publicznych. Projekt badania, metodyka badawcza, koncepcja - na podstawie integracyjnego przeglądu literatury określono cel opracowania. Dla osiągnięcia tego celu przeprowadzono badania empiryczne, które wykorzystują studium przypadku (case study) konkursów o Pomorską Nagrodę Jakości. W tym kontekście zastosowano metody badań jakościowych takie jak ustrukturyzowane wywiady bezpośrednie, analizę materiałów źródłowych oraz obserwacje uczestniczące. Wyniki/ wnioski - uczestnicy konkursów pozytywnie ocenili proces organizacji konkursu. Dostrzegali jednak problemy związane z wykorzystaniem arkusza samooceny. Były to m.in. zbyt duża pracochłonność związana z wypełnianiem arkusza przez uczestników konkursu oraz niezrozumienie zawartych w nim stwierdzeń i pojęć. Uwagi te potwierdzili także organizatorzy konkursu. W związku z aktualizacją Modelu EFQM, na którego założeniach i zasadach opierały się stosowane dotąd kryteria konkursowe, postanowiono uaktualnić Model Pomorskiej Nagrody Jakości. W tym celu wykorzystano Model EFQM w wersji z roku 2020, aktualną wersję modelu CAF oraz wnioski z przeprowadzonych przez autorów badań jakościowych. Opracowano nową wersję kwestionariusza samooceny oraz dostosowano skalę ocen i punktację stanowiącą podstawę określenia wyników w konkursach. Zastosowanie praktyczne - opracowany w roku 2023 model oceny w ramach Pomorskiej Nagrody Jakości może być stosowany jako podstawa rozwoju systemu zarządzania organizacją. Ankieta samooceny jest narzędziem doskonalenia obejmującym wiele obszarów działalności organizacji. Sam udział w konkursie jest poświadczeniem wysokiego poziomu świadomości projakościowej organizacji oraz sprzyjać może wymianie dobrych praktyk na szczeblu regionalnym oraz krajowym i międzynarodowym.

  • Modeling and Accuracy Assessment of Determining the Coastline Course Using Geodetic, Photogrammetric and Satellite Measurement Methods: Case Study in Gdynia Beach in Poland
    • Francesco Giuseppe Figliomeni
    • Mariusz Specht
    • Claudio Parente
    • Cezary Specht
    • Andrzej Stateczny
    2024 Pełny tekst Electronics

    The coastal environment represents a resource from both a natural and economic point of view, but it is subject to continuous transformations due to climate change, human activities, and natural risks. Remote sensing techniques have enormous potential in monitoring coastal areas. However, one of the main tasks is accurately identifying the boundary between waterbodies such as oceans, seas, lakes or rivers, and the land surface. The aim of this research is to evaluate the accuracy of coastline extraction using different datasets. The images used come from UAV-RGB and the Landsat-9 and Sentinel-2 satellites. The method applied for extracting the coast feature involves a first phase of application of the Normalized DifferenceWater Index (NDWI), only for satellite data, and consequent application of the maximum likelihood classification, with automatic vectorization. To carry out a direct comparison with the extracted data, a coastline obtained through a field survey using a Global Navigation Satellite System (GNSS) device was used. The results are very satisfactory as they meet the minimum requirements specified by the International Hydrographic Organization (IHO) S-44. Both the UAV and the Sentinel-2 reach the maximum order, called the Exclusive order (Total Horizontal Uncertainty (THU) of 5 m with a confidence level of 95%), while the Landsat-9 falls into the Special order (THU of 10 m with a confidence level of 95%).

  • Modeling and Strength Calculations of Parts Made Using 3D Printing Technology and Mounted in a Custom-Made Lower Limb Exoskeleton
    • Szczepan Śpiewak
    • Wiktoria Wojnicz
    • Jan Awrejcewicz
    • Magdalena Mazur
    • Michał Ludwicki
    • Bartosz Stańczyk
    • Bartłomiej Zagrodny
    2024 Pełny tekst Materials

    This study is focused on the application of 3D-printed elements and conventional elements to create a prototype of a custom-made exoskeleton for lower limb rehabilitation. The 3D-printed elements were produced by using Fused Deposition Modeling technology and acrylonitrile butadiene styrene (ABS) material. The scope of this work involved the design and construction of an exoskeleton, experimental testing of the ABS material and numerical research by using the finite element method. On the basis of the obtained results, it was possible to deduce whether the load-bearing 3D-printed elements can be used in the proposed mechanical construction. The work contains full data of the material models used in FEM modeling, taking into account the orthotropic properties of the ABS material. Various types of finite elements were used in the presented FE models. The work is a comprehensive combination of material testing issues with the possibility of implementing the obtained results in numerical strength models of machine parts.

  • Modeling lignin extraction with ionic liquids using machine learning approach
    • Karol Baran
    • Beata Barczak
    • Adam Kloskowski
    2024 Pełny tekst SCIENCE OF THE TOTAL ENVIRONMENT

    Lignin, next to cellulose, is the second most common natural biopolymer on Earth, containing a third of the organic carbon in the biosphere. For many years, lignin was perceived as waste when obtaining cellulose and hemicellulose and used as a biofuel for the production of bioenergy. However, recently, lignin has been considered a renewable raw material for the production of chemicals and materials to replace petrochemical resources. In this context, an increasing demand for high-quality lignin is to be expected. It is, therefore, essential to optimize the technological processes of obtaining it from natural sources, such as biomass. In this work, an investigation of the use of machine learning-based quantitative structure-property relationship (QSPR) modeling for the preliminary processing of lignin recovery from herbaceous biomass using ionic liquids (ILs) is described. Training of the models using experimental data collected from original publications on the topic is assumed, and molecular descriptors of the ionic liquids are used to represent structural information. The study explores the impact of both ILs' chemical structure and process parameters on the efficiency of lignin recovery from different bio sources. The findings give an insight into the extraction process and could serve as a foundation for further design of efficient and selective processes for lignin recovery using ionic liquids, which can have significant implications for producing biofuels, chemicals, and materials.

  • Modeling of free vibrations and resonant frequencies of simply-supported submerged horizontal plate
    • Justyna Slawinska-Budzich
    • Wojciech Sulisz
    • Jarosław Przewłócki
    2024 Pełny tekst PLOS ONE

    A theoretical approach was applied to study the vibration of simple-supported submerged horizontal plate. The derived analytical solution was used to determine natural frequencies for a horizontal plate vibrating in fluid. The investigations were conducted for a very wide range of material density and elasticity modulus covering all materials used in engineering practice. Analysis shows that plate vibration frequency decreases with increasing plate width and draft, and decreases with decreasing plate thickness. Moreover, the results show that a substantial effect on vibration of submerged plate has mass of water above plate. The results also show that plate vibration frequency decreases with increasing plate material density and decreases with decreasing elasticity modulus. The dominant factors affecting the vibration of the submerged plate are the plate width, the plate thickness, and elasticity modulus. For moderate and low values of elasticity modulus, vibration frequency is becoming lower than frequency of water waves. This is very important because wave frequencies overlap with the natural plate vibration frequencies, which may lead to resonance and failure of a structure. The problem is that the overlap of plate vibration frequencies and wave frequencies occurs for very wide range of wave and plate parameters. Laboratory experiments confirm theoretical results.

  • Modelling and Control of a Brushless Multiphase Doubly-Fed Induction Generator in a Stand-Alone Wind Generation System
    • Krzysztof Blecharz
    • Roland Ryndzionek
    • Filip Kutt
    2024 IEEE Access

    The development of the novel multiphase brushless doubly-fed generator system and voltage controller for stand-alone mode configuration is proposed in this paper. The generator system is based on the new machine construction with multiphase control winding and traditional three-phase power winding. The dynamic model of multiphase brushless doubly-fed generator is presented, and the control strategy for voltage amplitude and frequency is developed. The simulation and experimental results are used to validate the performance of the topology of the multi-phase brushless double-fed generator and of the control system. The tests of the generator system have been carried out for the normal operating state of the system and for the case where one of the control phase is inactive. This situation is equivalent to a failure in the power path of the control winding.

  • Modelling and simulations in time-fractional electrodynamics based on control engineering methods
    • Damian Trofimowicz
    • Tomasz Stefański
    • Jacek Gulgowski
    • Tomasz Talaśka
    2024 Communications in Nonlinear Science and Numerical Simulation

    In this paper, control engineering methods are presented with regard to modelling and simulations of signal propagation in time-fractional (TF) electrodynamics. That is, signal propagation is simulated in electromagnetic media described by Maxwell’s equations with fractional-order constitutive relations in the time domain. We demonstrate that such equations in TF electrodynamics can be considered as a continuous-time system of state-space equations in control engineering. In particular, we derive continuous-time analytical solutions based on state-transition matrices for electromagnetic-wave propagation in the TF media. Then, discrete-time zero-order-hold equivalent models are developed and their analytical solutions are derived. It is demonstrated that the proposed models give the same results as other reference methods presented in the literature. However, due to the application of finite-difference scheme, they remain more flexible in terms of the number of simulation scenarios which can be tackled.

  • Modelling of heat transfer during flow condensation of natural refrigerants under conditions of increased saturation pressure
    • Stanisław Głuch
    • Dariusz Mikielewicz
    2024 Pełny tekst Archives of Thermodynamics

    The paper presents a modified in-house model for calculating heat transfer coefficients during flow condensation, which can be applied to a variety of working fluids, but natural refrigerants in particular, at full range thermodynamic parameters with a particular focus on increased saturation pressure. The modified model is based on a strong physical basis, namely the hypothesis of analogy between the heat transfer coefficient and pressure drop in two-phase flow. The model verification is based on a consolidated database that consists of 1286 data points for 7 natural refrigerants and covers the reduced pressure range (the ratio of critical pressure and saturation pressure) from 0.1 to 0.8 for different mass velocities and diameters. The new version of the in-house model, developed earlier by Mikielewicz, was compared with 4 other mathematical models widely recommended for engineering calculations and obtained the best consistency results. The value of the mean absolute percentage error was 28.13% for the modified model, the best result among the scrutinised methods.

  • Modelling tunnelling-induced deformation in stiff soils with a hyperelastic–plastic anisotropic model
    • Marcin Cudny
    • Katarzyna Lisewska
    • Manuel Winkler
    • Thomas Marcher
    2024 Acta Geotechnica

    In this paper, the tunnelling-induced deformation in anisotropic stiff soils is analysed using FE modelling. The influence of material description is investigated rather than an advanced simulation of the tunnelling method. A new hyperelastic– plastic model is proposed to describe the anisotropic mechanical behaviour of stiff highly overconsolidated soil. This model can reproduce the superposition of variable stress-induced anisotropy and constant inherent cross-anisotropy of the small strain stiffness. Additionally, a Brick-type framework accounts for the strain degradation of stiffness. Formulation of the novel model is presented. The tunnelling-induced deformation is first investigated in plane strain conditions for a simple boundary value problem of homogeneous ground. The influence of initial stress anisotropy and inherent cross- anisotropy is inspected. Later, the results of 2D simulations are compared with the analogous results of 3D simulations considering different excavated length of the tunnel sections. The tunnelling process is reproduced by introduction of a supported excavation and a lining contraction stage in undrained conditions. Finally, the tunnelling case study at St James Park is back analysed using the proposed material model in plane strain conditions. The obtained calculation results are compared with the field measurements and discussed.

  • Modelowanie dokładności radiolokalizowania w różnych warunkach środowiskowych przy wykorzystaniu interfejsu radiowego 5G-NR
    • Piotr Rajchowski
    • Luis M. Correia
    • Krzysztof Cwalina
    2024 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    W artykule przedstawiono wyniki eksperymentalnych badań dokładności estymacji położenia terminala użytkownika korzystającego~z interfejsu radiowego 5G-NR. W środowisku miejskim dokonano rejestracji rzeczywistych sygnałów sieci 5G, a następnie przeprowadzono badania numeryczne. Celem było zweryfikowanie różnic dokładności estymacji położenia w trzech różnych środowiskach: wewnątrz- i zewnątrzbudynkowym oraz tzw. deep-indoor.

  • Modelowanie liczby i wielkości uszkodzeń drogowych barier ochronnych na odcinkach dróg
    • Łukasz Jeliński
    2024 Pełny tekst

    W ramach rozprawy doktorskiej podjęto problem funkcjonowania barier ochronnych, ze szczególnym uwzględnieniem częstości występowania oraz wielkości uszkodzeń barier na odcinkach dróg krajowych w Polsce. Rozpoznanie tematyki funkcjonowania barier ochronnych przy drogach, oraz identyfikacja nierozwiązanych problemów, pozwoliły na sformułowanie głównego celu pracy i celów szczegółowych. Cele te obejmują opracowanie i wdrożenie do praktyki drogowej modeli matematycznych szacowania częstości występowania oraz wielkości uszkodzeń barier ochronnych, stosowanych na dwujezdniowych drogach krajowych w Polsce. Cele rozprawy osiągnięto poprzez realizację procesu badawczego, składającego się z następujących etapów: studiów literatury, opracowania programu badań, wyboru poligonów badawczych i budowy baz danych, przeprowadzenia serii badań terenowych, poligonowych i symulacyjnych, modelowania częstości zdarzeń i wielkości uszkodzeń barier ochronnych, w zależności od najistotniejszych czynników konstrukcyjnych, drogowych, ruchowych i utrzymaniowych, badania wpływu zidentyfikowanych czynników na funkcjonowanie barier oraz opracowania polskiej metody szacowania częstości i wielkości uszkodzeń barier ochronnych na odcinkach dróg. W końcowej części pracy przedstawiono wnioski z przeprowadzonych badań i analiz, wskazano rekomendacje dotyczące wykorzystania i wdrożenia wyników badań oraz zaproponowano kierunki dalszych badań.

  • Modern control strategy of bidirectional DAB converter with consideration of control nonlinearity
    • Serafin Bachman
    • Marek Turzyński
    • Marek Jasiński
    2024 Pełny tekst Przegląd Elektrotechniczny

    This paper focuses on the control strategy for modern universal bidirectional Dual Active Bridge (DAB) converters for microgrid systems. An analysis of the converter equations was carried out, and typical problems related to the influence of dead time on the system operation were discussed. A closed control loop was developed, then tested by simulation and on a laboratory stand.

  • Modern Light Sources on the Ship
    • Romuald Maśnicki
    • Janusz Mindykowski
    • Beata Pałczyńska
    • Dawid Werner
    2024

    The paper deals with studies on light flicker in selected modern light sources used on ships. The authors present and discuss the relationship between the hostile ship environment affecting the ship light systems and the extreme working conditions of the ship's crew manifested by health problems and a reduction in their manual abilities. These limitations result from the flicker phenomena provoked by both fluorescent lamps and LED technology sources. The authors showed that the traditionally used flicker analysis based on Plt and Pst indicators is not sufficient to assess the effects related to the operation of a modern lighting system, because in addition to voltage fluctuations, the properties of the source, i.e. light intensity as an input signal, must also be taken into account. This approach based on Fi and Fp coefficients was verified experimentally using the dedicated author's setup. The presented discussion of the measurement results showed that the approach used so far to assess flicker phenomena has some weaknesses and ambiguities concerning LED technology sources.

  • Modification of gradient HPLC method for determination of small molecules' affinity to human serum albumin under column safety conditions: Robustness and chemometrics study
    • Mateusz Woziński
    • Katarzyna Greber
    • Monika Pastewska
    • Piotr Kolasiński
    • Weronika Hewelt-Belka
    • Beata Żołnowska
    • Jarosław Sławiński
    • Daniel Szulczyk
    • Wiesław Sawicki
    • Krzesimir Ciura
    2024 JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS

    In the early stages of drug discovery, beyond the biological activity screening, determining the physicochemical properties that affect the distribution of molecules in the human body is an essential step. Plasma protein binding (PPB) is one of the most important investigated endpoints. Nevertheless, the methodology for measuring %PPB is significantly less popular and standardized than other physicochemical properties, like lipophilicity. Here, we proposed how to modify protocols presented by Valko into column safety conditions and evaluated their robustness using fractional factorial design. For robustness testing, four factors were selected: column temperature, mobile phase flow rate, maximum isopropanol concentration in the mobile phase, and buffer pH. Elaborate methods have been applied for the analysis of HSA affinity for three groups of antibiotic-oriented substances that vary in chemical structure: fluoroquinolones, sulfonamides, and tetrazole derivatives. Furthermore, based on the reversed-phase chromatography the workflow of pilot studies was proposed to select molecules that have high affinity to HSA and can not be eluted from the HSA column using the concentration of organic modifier recommended by the column manufacturer

  • Modification of the Reloading Plastic Modulus in Generalized Plasticity Models for Soil by Introducing a New Equation for the Memory Parameter in Cyclic Loadings
    • Mohammad Oliaei
    • Reza Kamgar
    • Heisam Heidarzadeh
    • Robert Jankowski
    2024 Applied Sciences-Basel

    Nowadays, with the widespread supply of very powerful laboratory and computer equipment, it is expected that the analyses conducted for geotechnical problems are carried out with very high precision. Precise analyses lead to better knowledge of structures’ behavior, which, in turn, reduces the costs related to uncertainty of materials’ behavior. A precise analysis necessitates a precise knowledge and definition of the behavior of the constituent materials, which itself requires applying an appropriate constitutive model to show the behavior of materials. Constitutive models used in the generalized plasticity framework are very powerful constitutive models for the simulation of sand behavior. However, the simulation of a cyclic behavior in these models, especially the simulation of the undrained cyclic behavior, is not well-recognized. In this study, in order to eliminate the weakness of generalized constitutive models under cyclic loading, a new equation is presented to substitute the so-called coefficient of the discrete memory factor to consider the loading history in such a way that the plastic modulus is modified during reloading and, as a result, more appropriate predictions of sand behavior are obtained. The performance accuracy of the proposed coefficient was evaluated in accordance with the experimental data. Finally, the results show that after using the modification of the loading history coefficient, predictions of the constitutive model are significantly improved.

  • Modifications of silicate bioglass synthesis and composition for in vitro dissolution control: Static and dynamic assessment
    • Stefania Wolff
    • Sharafat Ali
    • Jakub Karczewski
    • Małgorzata Rutkowska
    • Hiroyo Segawa
    • Natalia Wójcik
    2024 JOURNAL OF NON-CRYSTALLINE SOLIDS

    A set of fifteen calcium-phosphate-silicate glass samples, varying in alkali, magnesium, silicon, and nitrogen content, was prepared, and their structural, thermal, and in vitro dissolution properties were analyzed. Infrared spectroscopy showed a high degree of depolymerization of the silicate network consisting mainly of Q2 and Q3 units. Thermal analysis showed that the silicon content primarily affects both the glass transition temperature and the thermal stability of the glasses. In vitro dissolution studies were conducted both in static and dynamic modes in phosphate-buffered saline. Greater weight loss was observed for materials tested in the dynamic mode than in the static mode. Ion concentration profiles determined for PBS after immersing the glasses showed the release of sodium and calcium into solutions. Subsequent studies, conducted using scanning electron microscopy, X-ray diffraction, and infrared spectroscopy showed the formation of an amorphous or crystalline layer of calcium phosphates, most likely hydroxyapatite.

  • Modified GAPI (MoGAPI) Tool and Software for the Assessment of Method Greenness: Case Studies and Applications
    • Fotouh R. Mansour
    • Justyna Płotka-Wasylka
    • Marcello Locatelli
    2024 Analytica

    The green analytical procedure index (GAPI) has been widely used to assess the greenness of different steps in analytical methodology. In the GAPI index, the different stages of the chemical analysis process are depicted using five pentagrams divided in subsections, labeled green, yellow, or red according to the degree of greenness. This GAPI tool provides a quick overview of the environmental impact and safety of the procedure. However, there is no total score that can be calculated from the GAPI metric to enable comparison between methods. In this work, a modified GAPI tool (MoGAPI) and software have been developed and applied to address the limitations of the current GAPI metric. The presented tool offers a more precise assessment of greenness, while the software simplifies and expedites its application. It also combines the advantages of the analytical Eco-Scale with the merits of the widely used GAPI metric. This tool was successfully applied to calculate the greenness of a few case studies and applications to show the applicability of this modified metric. The software for the MoGAPI tool is also freely available (open source) at bit.ly/MoGAPI to facilitate application and method comparison. The MoGAPI tool and its software represent a significant advancement in greenness assessment, providing researchers with a robust and user-friendly means to evaluate and compare analytical methods.

  • Modified sliding mode control for seamless integration of P.V. energy in A.C. grid
    • Shoaib Shaikh
    • Arsalan Muhammad Soomar
    • Kifayat Ullah
    • Emad A.A. Ismail
    • Fuad A. Awwad
    • Muhammad Kamran
    • Piotr Musznicki
    • Syed Hadi Hussain Shah
    2024 Pełny tekst Energy Reports

    Solar energy is a potentially abundant and reliable source of renewable energy. While it can undoubtedly increase grid reliability and efficiency, the inverted voltage generated from PV. sources may introduce distortion into the AC. grid. The proposed control mechanism, modified sliding mode control (MSMC), can seamlessly integrate the inverter output generated by obtaining DC. voltage from the boost converter linked with the PV. output. This research confirms the validity of the proposed method by comparing its results with a similar system that is only integrated through filters and with a system with a P.I. control technique. The simulation proves the effectiveness of seamlessly integrating the Photovoltaic (PV) source into the AC. grid.

  • Molecular Design Using Selected Concentration Effects in Optically Activated Fluorescent Matrices
    • Aneta Lewkowicz
    • Katarzyna Walczewska-Szewc
    • Martyna Czarnomska
    • Emilia Gruszczyńska
    • Mattia Pierpaoli
    • Robert Bogdanowicz
    • Zygmunt Gryczynski
    2024 Pełny tekst INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    Molecular physics plays a pivotal role in various fields, including medicine, pharmaceuticals, and broader industrial applications. This study aims to enhance the methods for producing specific optically active materials with distinct spectroscopic properties at the molecular level, which are crucial for these sectors, while prioritizing human safety in both production and application. Forensic science, a significant socio-economic field, often employs hazardous substances in analyzing friction ridges on porous surfaces, posing safety concerns. In response, we formulated novel, non-toxic procedures for examining paper evidence, particularly thermal papers. Our laboratory model utilizes a polyvinyl alcohol polymer as a rigid matrix to emulate the thermal paper’s environment, enabling precise control over the spectroscopic characteristics of 1,8-diazafluoro-9-one (DFO). We identified and analyzed the cyclodimer 1,8-diazafluoren-9-one (DAK DFO), which is a non-toxic and biocompatible alternative for revealing forensic marks. The reagents used to preserve fingerprints were optimized for their effectiveness and stability. Using stationary absorption and emission spectroscopy, along with time-resolved emission studies, we verified the spectroscopic attributes of the new structures under deliberate aggregation conditions. Raman spectroscopy and quantum mechanical computations substantiated the cyclodimer’s configuration. The investigation provides robust scientific endorsement for the novel compound and its structural diversity, influenced by the solvatochromic sensitivity of the DFO precursor. Our approach to monitoring aggregation processes signifies a substantial shift in synthetic research paradigms, leveraging simple chemistry to yield an innovative contribution to forensic science methodologies.

  • Molecular transformation of dissolved organic matter in manganese ore-mediated constructed wetlands for fresh leachate treatment
    • Md. Hasibur Rahaman
    • Tong Yang
    • Zhongyi Zhang
    • Wenbo Liu
    • Zhongbing Chen
    • Jacek Mąkinia
    • Jun Zhai
    2024 JOURNAL OF ENVIRONMENTAL MANAGEMENT

    The organic matter (OM) and nitrogen in Fresh leachate (FL) from waste compression sites pose environmental and health risks. Even though the constructed wetland (CW) can efficiently remove these pollutants, the molecular-level transformations of dissolved OM (DOM) in FL remain uncertain. This study reports the molecular dynamics of DOM and nitrogen removal during FL treatment in CWs. Two lab-scale vertical-flow CW systems were employed: one using only sand as substrates (act as a control, CW-C) and the other employing an equal mixture of manganese ore powder and sand (experimental, CW-M). Over 488 days of operation, CW-M exhibited significantly higher removal rates for chemical oxygen demand (COD), ammonia nitrogen (NH4 +-N), and dissolved organic matter (represented by dissolved organic carbon, DOC) at 98.2 ± 2.5%, 99.2 ± 1.4%, and 97.9 ± 1.9%, respectively, in contrast to CW-C (92.8 ± 6.8%, 77.1 ± 28.1%, and 74.7 ± 9.5%). The three-dimensional fluorescence excitation-emission matrix (3D-EEM) and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) analyses unveiled that the influent DOM was predominantly composed of readily biodegradable protein-like substances with high carbon content and low unsaturation. Throughout treatment, it led to the degradation of low O/C and high H/C compounds, resulting in the formation of DOM with higher unsaturation and aromaticity, resembling humic-like substances. CW-M showcased a distinct DOM composition, characterized by lower carbon content yet higher unsaturation and aromaticity than CW-C. The study also identified the presence of Gammaproteobacteria, reported as Mn-oxidizing bacteria with significantly higher abundance in the upper and middle layers of CW-M, facilitating manganese cycling and improving DOM removal. Key pathways contributing to DOM removal encompassed adsorption, catalytic oxidation by manganese oxides, and microbial degradation. This study offers novel insights into DOM transformation and removal from FL during CW treatment, which will facilitate better design and enhanced performance.

  • Molecularly imprinted polymers based on deep eutectic solvents as a greenest materials for selective extraction of emerging contaminants from complex samples
    • Mariusz Marć
    • Natalia Jatkowska
    • Justyna Płotka-Wasylka
    • Daniel Gallart-Mateu
    • Francesc A. Esteve‐turrillas
    • Miguel De la Guardia
    2024 TRAC-TRENDS IN ANALYTICAL CHEMISTRY

    Some of the reagents applied in the synthesis of molecularly imprinted polymers (MIPs) may impact on health and the environment. Thus, a new generation of promising green chemicals are nowadays introduced and investigated, including deep eutectic solvents (DESs). DESs seems to be a reasonable choice as they are characterized as non-toxic, low cost, easy to prepare and biodegradable chemicals. This review presents the information on imprinted materials prepared using versus polymerization techniques on which DESs were applied as a more green reagents. Paper presents the benefits and roles of DESs application in the synthesis of MIPs and their potential application area such as selective and reversible sorbents/resins in analytes extraction process as well as chromatographic stationary phases. Furthermore, the specific fields of application of new type of DES-based MIPs in environmental, food and biological samples analysis are described and the future remarks in the area of DES-based MIPs are discussed.

  • Molecularly imprinted polymers for the detection of volatile biomarkers
    • Tomasz Wasilewski
    • Sinem Orbay
    • Nathália F. Brito
    • Karol Sikora
    • Ana Claudia A. Melo
    • Matias E. Melendez
    • Bartosz Szulczyński
    • Amitav Sanyal
    • Wojciech Kamysz
    • Jacek Gębicki
    2024 Pełny tekst TRAC-TRENDS IN ANALYTICAL CHEMISTRY

    In the field of cancer detection, the development of affordable, quick, and user-friendly sensors capable of detecting various cancer biomarkers, including those for lung cancer (LC), holds utmost significance. Sensors are expected to play a crucial role in the early-stage diagnosis of various diseases. Among the range of options, sensors emerge as particularly appealing for the diagnosis of various diseases, owing to their cost-effectiveness, simplicity, and promising analytical performance. There is growing interest in the application of molecularly imprinted polymers (MIPs) as promising recognition elements in gas sensors. MIPs, as a leading technology for sensing analytes where no suitable bioreceptor exists, are commonly used in artificial sensing that can be applied in key fields like early disease diagnostics, based on the detection of volatile biomarkers. There is an extensive demand for early, non-invasive detection of various diseases and for the self-monitoring of health conditions. Detection of biomarkers in point-of-care mode remains challenging and is limited by various factors. Hence, breath analysis has received enormous attention in healthcare due to its relatively low cost, non-invasive sampling method, and rapid detection capabilities. The latest developments in MIP-based sensors and their utility in disease diagnosis through the detection of volatile biomarkers are comprehensively and critically evaluated in this review. Furthermore, the challenges and perspectives of MIP-based sensors are elaborated upon, with a view towards introduction to the market and successful commercialization.

  • Molybdenum sulfide modified with nickel or platinum nanoparticles as an effective catalyst for hydrogen evolution reaction
    • Mariusz Szkoda
    • Daria Roda
    • Malgorzata Skorupska
    • Rafał Glazer
    • Anna Ilnicka
    2024 Scientific Reports

    In this study, we investigate the catalytic performance of molybdenum sulfide (MoS2) modified with either nickel (Ni) or platinum (Pt) nanoparticles as catalysts for the hydrogen evolution reaction (HER). The MoS2 was prepared on the TiO2 nanotube substrates via a facile hydrothermal method, followed by the deposition by magnetron sputtering of Ni or Pt nanoparticles on the MoS2 surface. Structural and morphological characterization confirmed the successful incorporation of Ni or Pt nanoparticles onto the MoS2 support. Electrochemical measurements revealed that Ni- and Pt-modified MoS2 catalysts exhibited enhanced HER activity compared to pristine MoS2. Obtained catalysts demonstrated a low onset potential, reduced overpotential, and increased current density, indicating efficient electrocatalytic performance. Furthermore, the Ni or Pt-modified MoS2 catalyst exhibited remarkable stability during prolonged HER operation. The improved catalytic activity can be attributed to the synergistic effect between metal nanoparticles and MoS2, facilitating charge transfer kinetics and promoting hydrogen adsorption and desorption. Incorporating Ni and Pt nanoparticles also provided additional active sites on the MoS2 surface, enhancing the catalytic activity.

  • Monitoring of Ship Operations in Seaport Areas in the Sustainable Development of Ocean–Land Connections
    • Mirosław Gerigk
    • Jacek Jachowski
    • Zbigniew Burciu
    • Teresa Abramowicz-Gerigk
    2024 Sustainability

    The paper is devoted to underlining the important role of monitoring systems in the sustainable development of seaport areas—sensitive ocean–land connections exposed to the harmful effects of multimodal transport. The study concerns the existing monitoring possibilities of the environmental factors and ship traffic near port infrastructure. The main aim of the study is presenting the example of solutions, supporting the sustainable development of port areas, related to the most dangerous ship maneuvering operations carried out near the berths. An indirect method for measuring loads on the seabed from the propeller and thruster jets during ship berthing and an experimental method for predicting the hydrodynamic forces generated on a moored Panamax-size bulk carrier by a similar vessel passing along in shallow water conditions are described in the context of their implementation in monitoring systems. The cloud-based system—installed in the ferry terminal in the Port of Gdynia and developed for monitoring the flow generated by the ship propellers during maneuvers near the berth and warning about the exceedance of allowable pressure on the quay wall—allows, after a two-year operation, to draw the conclusions related to maintenance planning and has an impact on port sustainability. The discussion presented in the paper underlines the influence of monitoring both the environmental elements and hazardous ship operations on the sustainable development of seaport areas.

  • Monometallic/Bimetallic Co‐ZIFs Synthesis, Characterization, and Application for Adsorption of SO2 and CO2 in Continuous Flow System
    • Sara Sumbal
    • Zaheer Aslam
    • Umar Irshad
    • Sobia Anwar
    • Aamir Abbas
    • Waqar Ahmad
    • Ali Hamza
    2024 APPLIED ORGANOMETALLIC CHEMISTRY

    Sulfur dioxide is serious ultimatum to human health as well as environment, while carbon dioxide is viewed as one of the primary drivers of the worldwide temperature alteration. Therefore, capturing of these gases is a dynamic research subject attracting much consideration from scientists. Herein, we report synthesis of a series of Co-ZIF and bimetallic M-Co-ZIF adsorbents and application for room temperature adsorption of SO2 and CO2. In this work, the breakthrough curves for the adsorption of sulfur dioxide and carbon dioxide on Co-ZIF and M-Co-ZIF were obtained experimentally and theoretically using a laboratory-scale fixed bed column at room temperature. In this work, the adsorption capacities and breakthrough points for modified bimetallic M-Co-ZIF were found to be relatively higher than parent Co-ZIF. Notably, a high SO2 uptake capacity of 7.1 mmol/g for Zr-Co-ZIF and high CO2 uptake capacity of 69.9 mmol/g for Ni-Co-ZIF were achieved. The parent cobalt and bimetallic ZIF materials were characterized by XRD, FTIR, SEM, and nitrogen physisorption. The XRD results confirm the formation of pure phase highly crystalline ZIF materials while BET analysis suggests high surface area of prepared adsorbents. Finally, the results of dynamic adsorption combined with characterization show great potential for preparation of bimetallic ZIF adsorbents for effective SO2 and CO2 adsorption.

  • Monte Carlo simulations of the fracture resistance of an asphalt pavement layer
    • Łukasz Smakosz
    • Cezary Szydłowski
    • Jarosław Górski
    2024 CONSTRUCTION AND BUILDING MATERIALS

    The purpose of the proposed numerical model is to analyze the cracking of the wearing course in a pavement overlay, assuming a pre-existing crack that passes through the binding layer and base. The computations employed the author's simulation-based Monte Carlo material model, which describes the failure process of a Semi-Circular Bend (SCB) specimen during standard laboratory testing of asphalt concrete. A key feature of this model is the incorporation of the random nature of material parameters, allowing for the simulation of result dispersion when analyzing a sufficiently large population of samples. The proposed FEM model and obtained material data were directly applied to the numerical analysis of the pavement structure. The comprehensive computational algorithm allows for a random description of the load that induces crack propagation in the pavement wearing course, leading to the creation of a histogram that defines the range of failure load dispersion. Such supporting calculations can assist in optimizing asphalt mix design and, in the future, may allow for the estimation of pavement structure reliability.

  • Monte-Carlo Modeling of Optical Sensors for Postoperative Free Flap Monitoring
    • Paulina Stadnik
    • Ignacy Rogoń
    • Mariusz Kaczmarek
    2024 Pełny tekst

    This work aims to develop a numerical tissue model and implement software to simulate photon propagation using the Monte Carlo method to determine design guidelines for a physical measurement system. C++ was used for the simulation program, and Python as a programming environment to create an interface that allows the user to customize individual simulation elements, allowing for increased accuracy and flexibility when simulating photon movement. This allows the user to customize the simulation to their specific requirements, ensuring the results are as accurate and reliable as possible. It also models the detector to determine if a given photon is in the desired location. The program simulates the propagation of light from a normal illumination medium with anisotropic scattering and records the escape of photons on the upper surface. The simulation also takes into account absorption and scattering coefficients for a given wavelength, and data regarding these parameters are read from a .csv file. The variance reduction technique is used to improve the efficiency of the simulation. The user interface allows users to define their own parameters, such as wavelength, anisotropy coefficient, refractive index, and layer thickness. In this paper, we simulate four photodiodes and different distances between the source and detector to determine the most suitable model for designing a physical sensor.

  • More than just a beer – Brewers' spent grain, spent hops, and spent yeast as potential functional fillers for polymer composites
    • Aleksander Hejna
    • Mateusz Barczewski
    • Paulina Kosmela
    • Joanna Aniśko
    • Joanna Szulc
    • Katarzyna Skórczewska
    • Adam Piasecki
    • Tairong Kuang
    2024 WASTE MANAGEMENT

    Beer is among the most popular beverages in the world, with the production distributed uniformly between the biggest continents, so the utilization of brewing by-products is essential on a global scale. Among their potential recipients, the plastics industry offers extensive range of potential products. Herein, the presented study investigated the application of currently underutilized solid brewing by-products (brewers' spent grain, spent hops, spent yeast) as fillers for highly-filled poly(ε-caprolactone)-based composites, providing the first direct connection between spent hops or spent yeast and the polymer composites. Comprehensive by-product characterization revealed differences in chemical composition. The elemental C:O ratio, protein content, and Trolox equivalent antioxidant capacity varied from 1.40 to 1.89, 12.9 to 32.4 wt%, and 2.41 to 10.24 mg/g, respectively, which was mirrored in the composites' structure and performance. Morphological analysis pointed to the composition-driven hydrophilicity gap limiting interfacial adhesion for high shares of brewers' spent grain and spent hops, due to high hydrophilicity induced by carbohydrate content. Phytochemicals and other components of applied by-products stimulated composites' oxidative resistance, shifting oxidation onset temperature from 261 °C for matrix over 360 °C for high spent yeast shares. Simultaneously, spent yeast also provided compatibilizing effects for poly(ε-caprolactone)-based composites, reducing complex viscosity compared to other fillers and indicating its highest affinity to poly(ε-caprolactone)due to the lowest hydrophilicity gap. The presented results indicate that the proper selection of brewing by-products and adjustment of their shares creates an exciting possibility of engineering composites' structure and performance, which can be transferred to other polymers differing with hydrophilicity.

  • Morphology and internal structure of small-scale washovers formed in the coastal zone of the semi-enclosed tideless basin, Gulf of Gdańsk, Baltic Sea
    • D. Moskalewicz
    • F. Bahr
    • Łukasz Janowski
    • K. Leszczyńska
    • P. Sitkiewicz
    • M. Słowik
    • K. Stattegger
    • Paweł Tysiąc
    • C. Winter
    2024 GEOMORPHOLOGY

    This study explores the morphological features and internal structure of small-scale washovers along the southeastern Baltic Sea coast, providing insights into these most widespread yet often neglected deposits in the recent research of geomorphological and sedimentary record of storm surges. A 15-year-long record of morphological changes of the coast was acquired from regional orthophotos to analyse their geometry and spatial characteristics. Sedimentological analyses comprising a description of deposits, grain size and shape analyses, and Ground Penetrating Radar profiling were undertaken to investigate the internal structure of washovers. The formation of washovers appeared to be correlated with the average winter NAO (North Atlantic Oscillation) index. The study revealed different scaling relationships of selected spatial parameters in two coastal settings and extended previously hypothesized relationships of length-area, area-volume, and length-volume. The internal structure of washovers is defined by low-angle planar cross-stratification and horizontal stratification, both disrupted by small troughs. Grain-size data indicated extremely short transport of dune and beach sediments, lately deposited in the form of washovers. The study proves that in all domains, the geomorphological characteristics of washovers are scalable, despite the different coastal settings, and even small-scale washovers fit the existing development models

  • Most średnicowy w Warszawie. Koncepcja przebudowy
    • Krzysztof Żółtowski
    • Mikołaj Binczyk
    • Przemysław Kalitowski
    • Piotr Żółtowski
    • Sebastian Chylewski
    • Daniel Pełka
    • Tomasz Jabłoński
    2024 Mosty

    Artykuł omawia koncepcję przebudowy Mostu Średnicowego w Warszawie, który, ze względu na zły stan techniczny i nieprzystosowanie do współczesnych wymagań, wymaga rekonstrukcji. Planowana przebudowa obejmuje wykorzystanie istniejących filarów nurtowych oraz wydłużenie mostu, co pozwoli na eliminację wiaduktów nad Wisłostradą i Wybrzeżem Szczecińskim. Przedstawiono trzy warianty konstrukcyjne: kratownicę o zmiennej wysokości, skrzynkowe przęsła blachownicowe oraz konstrukcję nawiązującą do pierwotnego projektu z lat 20. XX wieku. Analizy nośności i detali konstrukcyjnych wykonano przy użyciu zaawansowanych modeli numerycznych w środowisku MES SOFiSTiK. Ostatecznie inwestor wybrał do dalszego projektowania wariant łukowy. Prace projektowe były częścią większej modernizacji całej Linii Średnicowej w Warszawie, której realizacja ma kluczowe znaczenie dla funkcjonowania stołecznego węzła kolejowego.

  • MSP for port areas – To what extent should we interfere with governance of ports’ waters? Case study of Polish seaports
    • Ernest Czermański
    • Magdalena Matczak
    • Aneta Oniszczuk-Jastrząbek
    • Karolina Krośnicka
    • Joanna Witkowska
    2024 Pełny tekst MARINE POLICY

    The EU MSP Directive imposed the requirement to develop plans for all water areas under the jurisdiction of an EU country by the end of March 2021. Poland is the only country in the Baltic Sea Region whose maritime administration has decided to elaborate detailed maritime spatial plans for port waters. The aim of the paper is to draw conclusions from the work carried out so far on the MSP for Polish port water areas. For this purpose, the drafts of the first ever plans for port areas, constituting Poland’s internal marine waters, were considered. The authors analysed planning efforts concerning Polish port water areas in two stages, quantitative and qualitative. The subjects of the analysis were the draft spatial maritime plans, prepared or in preparation, for three selected ports – Gdańsk, Szczecin and Elbląg. These study cases were chosen to represent the best variety of approaches (they were elaborated by different planning companies, having very different planning backgrounds) and were the basis for evaluating the solutions proposed in the draft plans in terms of possible interpretations of the plan’s provisions. The paper raises such questions as: What kind of functions (uses) occur while elaborating the maritime spatial plan of the port’s waters?; How are the functions distinguished within the ports’ plans interpreted by planers originating from different environments and having different types of planning experience?; How could the process of maritime spatial planning for port waters be coordinated between port authorities, maritime administration, and municipal authorities?

  • Multi-Analytical Techniques for the Study of Burial Clothes of Polish King Sigismund III Vasa (1566–1633) and His Wife Constance Habsburg (1588–1631)
    • Magdalena Śliwka-Kaszyńska
    • Maria Cybulska
    • Anna Drążkowska
    • Sławomir Kuberski
    • Jakub Karczewski
    • Anna Marzec
    • Przemysław Rybiński
    2024 Pełny tekst MOLECULES

    The subjects of this research are the burial clothes of Polish King Sigismund III Vasa and his wife Constance, which were woven and embroidered with silk and metal threads. Fragments of the textiles underwent spectroscopic, spectrometric, and thermogravimetric analyses. The hydrofluoric acid extraction method was improved to isolate various classes of dyes from the textile samples that had direct contact with human remains. High-performance liquid chromatography, coupled with diode array and tandem mass spectrometry detectors with electrospray ionization (HPLC-DAD-ESIMS/ MS) facilitated the detection and identification of colorants present in the textiles. Cochineal, indigo-, madder-, orchil-, and tannin-producing plants were identified as the sources of dyes used. Scanning electron microscopy with an energy-dispersive X-ray detector (SEM-EDS) was employed to identify and characterize the silk fibers and mordants and the metal threads. The presence of iron, aluminum, sodium, and calcium in the silk threads suggests their potential use as mordants. The analysis of the metal threads revealed that most of them were made from flattened gilded silver wire, with only a few being cut from a sheet of metal. Typical degradation mechanisms of metal threads were shown, resulting from both burial environment and earlier manufacturing process, and the use of the textiles in clothing, i.e., a significant loss of the gold layer was observed in most of silver gilt threads, caused by abrasion and delamination. The results of the thermal analysis confirmed the presence of silk and silver threads in the examined textiles.

  • Multi-channel radio-over-fiber communication systems through modulation instability phenomenon
    • Rasul Azizpour
    • Hassan Zakeri
    • Gholamreza Moradi
    • Mohammad Alibakhshikenari
    • Francisco Falcone
    • Liu Bo
    • Tayeb Dendini
    • Imko Park
    • Sławomir Kozieł
    • Ernesto Limiti
    2024 Pełny tekst IEEE Photonics Journal

    Recent advancements in Radio-over-Fiber (RoF) technology have positioned it as a promising solution for highcapacity wireless communications. This paper explores novel applications of RoF systems in enhancing phased array antenna (PAA) performance for multi-channel wireless communication applications through the modulation instability (MI) phenomenon. Utilizing fibers experiencing MI with varying group velocity dispersions (β2) of -20, -11.3, -3.2, and -2 ps2/km, the RoF system achieves operational flexibility across distinct central frequencies of 12, 16, 30, and 38 GHz, respectively. This approach represents a significant advancement in wireless communication technology, leveraging MI gain and an MI-based control system architecture to enhance performance across diverse frequency bands. The study investigates the impact of MI on modulation efficiency, presenting experimental results validating the feasibility and effectiveness of the proposed approach. The maximum MI gain by employing a 30 km fiber under MI is 18 dB, experimentally. Further optimization, achieved by increasing the fiber length to 45 km and adjusting nonlinear parameters and input power, demonstrates a remarkable MI gain of 38.1 dB. MIbased true time delay (TTD) techniques also address beam squint challenges, enhancing beamforming capabilities. The findings suggest that integrating MI into RoF systems holds excellent potential for improving wireless communication capabilities with reduced costs and space requirements compared to conventional methods. This research contributes to the growing body of knowledge in the field of RoF systems and offers insights into their practical applications in modern wireless communication networks.

  • Multi-factor fuzzy sets decision system forecasting consumer insolvency risk
    • Tomasz Korol
    2024 Decision

    The objective of this study is to develop a multi-factor decision system predicting insolvency risk for natural persons with the use of fuzzy sets. Considering that the financial situation of households is affected by various endogenous and exogenous factors, the main assumption of this study is that the system for predicting financial difficulties should not be limited to the use of only a few financial variables concerning consumers, but also include variables describing the environment. The author proposes a system consisting of three different forecasting models that connect the macroeconomic and microeconomic environments. It monitors the economic situation of households by also identifying those environmental variables, which may directly, or indirectly, endanger the consumer, such as unemployment rate (job market situation), inflation and interest rates, exchange rates, or economic situation in the country (GDP growth rate, the dynamics of retail sales, etc.). Moreover, the created multi-factor tool is in the form of a flexible application that can be easily adapted to changing economic conditions. Another unique feature of the study is the proposed use of newly developed ratios in household finance, similar to that in financial ratio analysis, which is commonly used in corporate finance. The proposed ratios demonstrated high predictive abilities. The paper also identifies the predictive capabilities of selected macroeconomic variables from the perspective of their impact on the risk of consumer insolvency. The research relies on four samples consisting of a total of 2,400 consumers from Taiwan and Poland. The author created three forecasting models separately for the South-East Asian and Central European regions, and two multi-factor systems, each consisting of 1260 decision rules. The findings clearly showed that a multi-factor system is a significantly more effective method compared to single forecasting models.

  • Multi-GPU UNRES for scalable coarse-grained simulations of very large protein systems
    • Krzysztof Ocetkiewicz
    • Cezary Czaplewski
    • Henryk Krawczyk
    • Agnieszka Lipska
    • Adam Liwo
    • Jerzy Proficz
    • Adam K. Sieradzan
    • Paweł Czarnul
    2024 COMPUTER PHYSICS COMMUNICATIONS

    Graphical Processor Units (GPUs) are nowadays widely used in all-atom molecular simulations because of the advantage of efficient partitioning of atom pairs between the kernels to compute the contributions to energy and forces, thus enabling the treatment of very large systems. Extension of time- and size-scale of computations is also sought through the development of coarse-grained (CG) models, in which atoms are merged into extended interaction sites. Implementation of CG codes on the GPUs, particularly the multiple-GPU platforms is, however, a challenge due to more complicated potentials and removing the explicit solvent, forcing developers to do interaction- rather than space-domain decomposition. In this paper, we propose a design of a multi-GPU coarse-grained simulator and report the implementation of the heavily coarse-grained physics-based UNited RESidue (UNRES) model of polypeptide chains. By moving all computations to GPUs and keeping the communication with CPUs to a minimum, we managed to achieve almost 5-fold speed-up with 8 A100 GPU accelerators for systems with over 200,000 amino-acid residues, this result making UNRES the best scalable coarse-grained software and enabling us to do laboratory-time millisecond-scale simulations of such cell components as tubulin within days of wall-clock time.

  • Multi-GPU-powered UNRES package for physics-based coarse-grained simulations of structure, dynamics, and thermodynamics of protein systems at biological size- and timescales
    • Cezary Czaplewski
    • Paweł Czarnul
    • Henryk Krawczyk
    • Agnieszka Lipska
    • Emilia Lubecka
    • Krzysztof Ocetkiewicz
    • Jerzy Proficz
    • Adam Sieradzan
    • Rafał Ślusarz
    • Józef Liwo
    2024 BIOPHYSICAL JOURNAL

    Coarse-grained models are nowadays extensively used in biomolecular simulations owing to the tremendous extension of size- and time-scale of simulations. The physics-based UNRES (UNited RESidue) model of proteins developed in our laboratory has only two interaction sites per amino-acid residue (united peptide groups and united side chains) and implicit solvent. However, owing to rigorous physics-based derivation, which enabled us to embed atomic details in the energy function, it is able to model the structures, dynamics, and thermodynamics of protein systems at good accuracy without ancillary information from structural databases. The UNRES package is an implementation of the UNRES model and uses Langevin molecular dynamics and its extensions for conformational search. It can be applied in both unrestrained simulations and those with restraints from experimental data or bioinformatics models. The package has been heavily optimized for memory and parallel performance using the message passing interface (MPI) and OpenMP libraries. Further, a GPU (graphical processor unit) and a well-scalable multiple-GPU version have been developed, thus enabling us to reach about 1 ms laboratory time in 1 day of computations for a chunk of tubulin comprising 234,260 amino-acid residues. In this communication the recent developments of the UNRES package will be presented and illustrated with appropriate examples including the simulations of (i) the dynamics of human norovirus variants, (ii) the dynamics of kinesin binding to tubulin, (iii) the conversion of thermal energy into net rotational motion by selected molecular rotatory motors, (iv) prediction of the structures of proteins and protein assemblies in recent CASP/CAPRI experiments and (iv) determination of protein structures at coarse-grained level using ambiguous NMR data. The optimized UNRES package is available from www.unres.pl and https://projects.task.gda.pl/eurohpcpl-public/unres.