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Gdańsk University of Technology

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Publications from the year 2024

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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 Full text 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 and Lightweight ESPAR Antenna for WSN and IoT Applications
    • Luiza Leszkowska
    • Mateusz Czeleń
    • Mateusz Rzymowski
    • Krzysztof Nyka
    • Łukasz Kulas
    2024 Full text

    A new compact ESPAR antenna is investigated in this paper. The proposed antenna has 12 directional radiation patterns based on 12 passive elements and can be successfully used in Wireless Sensor Network applications. In proposed antenna design, the possibilities of 3D printing were used to implement a dielectric miniaturization overlay that allowed for reducing antenna occupied area by almost 60% and antenna profile by 27% in comparison to the standard ESPAR antenna. The total dimensions of the antenna are 98 mm in diameter and 20.25 mm in height, while the weight of the antenna is only 86 g, which makes it much more suitable for potential use in UAV-based wireless communication applications.

  • Miniaturized Dual-Band Bandpass Filter with Wide Inter Stopband for 5G Applications
    • Earla Shankar
    • Kanaparthi V. 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 Full text 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.

  • Min-max optimization of node‐targeted attacks in service networks
    • Bernard Fortz
    • Mariusz Mycek
    • Michał Pióro
    • Artur Tomaszewski
    2024 NETWORKS

    This article considers resilience of service networks that are composed of service and control nodes to node-targeted attacks. Two complementary problems of selecting attacked nodes and placing control nodes reflect the interaction between the network operator and the network attacker. This interaction can be analyzed within the framework of game theory. Considering the limited performance of the previously introduced iterative solution algorithms based on non-compact problem models, new compact integer programming formulations of the node attack optimization problem are proposed, which are based on the notion of pseudo-components and on a bilevel model. The efficiency of the new formulations is illustrated by the numerical study that uses two reference networks (medium-size and large-size), and a wide range of the sizes of attacks and controllers placements.

  • M-integral for finite anti-plane shear of a nonlinear elastic matrix with rigid inclusions
    • Victor Eremeev
    • Konstantin Naumenko
    2024 Full text 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 Full text 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-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 Full text

    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 Full text

    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 Full text

    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.

  • Modele biznesu akademickich spółek spin-off w Polsce
    • Kamil Brodnicki
    2024

    Przesłankami do podjęcia tematu w niniejszej pracy były luki badawcze dotyczące m.in. braku jednoznacznego i spójnego pojmowania akademickich spółek spin-off. Podmiotem badań były akademickie spółki spin-off w Polsce, utworzone w latach 2011 – 2020, za pośrednictwem spółek celowych uczelni, natomiast przedmiotem badań były modele biznesu tychże spółek. Celem głównym dysertacji było: zweryfikowanie i zdefiniowanie modeli biznesu akademickich spółek spin-off w Polsce, powstałych przy udziale spółek celowych uczelni, wraz z elementami stanowiącymi te modele. W części teoretycznej zawarto zagadnienia opisujące spółki spin-off, dokonano przeglądu literatury przedmiotu, koncentrując się na akademickim podejściu do ich tworzenia i funkcjonowania. Ponadto przedstawiono rozważania definicyjne, zagadnienia klasyfikacyjne oraz podstawy prawne tworzenia akademickich spółek spin-off w Polsce. Opisano czynniki sprzyjające tworzeniu i funkcjonowaniu oraz bariery ograniczające powstawanie tychże spółek. Przedstawiono również rozważania dotyczące definicji pojęcia modelu biznesu na podstawie przeglądu krajowej i zagranicznej literatury przedmiotu oraz elementy kształtujące ten model. W części empirycznej przedstawiono metodykę badań (badania ilościowe i jakościowe), zastosowane narzędzia i metody badawcze (m.in. kwestionariusz ankietowy, Analiza Głównych Składowych - PCA, Analiza Wiązkowa - Cluster Analysis, Analiza Korelacji, Analiza porównawcza) oraz wyniki z przeprowadzonych badań. W dysertacji opracowano autorski teoretyczny model biznesu akademickich spółek spin-off oraz bazę spółek celowych i akademickich spółek spin-off w Polsce. Zdefiniowano i sklasyfikowano czynniki oddziałujące na modele biznesu akademickich spółek spin-off w świetle prowadzonych badań empirycznych, tj. determinanty, ocena cech inicjatora/założyciela, które oddziaływały na zakładanie akademickiej spółki spin-off, bariery wewnętrzne i zewnętrzne mające wpływ na proces zakładania i funkcjonowania akademickich spółek spin-off. Następnie dokonano weryfikacji modeli biznesu akademickich spółek spin-off funkcjonujących w Polsce. W wyniku przeprowadzonych analiz PCA i CA oraz analizy porównawczej stwierdzono pięć rodzajów modeli akademickich spółek spin-off, z czego tylko jeden model jest tożsamy z modelem opisanym w literaturze, zaś pozostałe cztery modele biznesu nie zostały dotychczas scharakteryzowane w teorii.

  • 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 Full text 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 Full text 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 Full text 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.