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Gdańsk University of Technology

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Publications from the year 2024

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  • 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.

  • Modeling of free vibrations and resonant frequencies of simply-supported submerged horizontal plate
    • Justyna Slawinska-Budzich
    • Wojciech Sulisz
    • Jarosław Przewłócki
    2024 Full text 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.

  • Modeling with the Anaerobic Digestion Model No. 1 for Enhanced Understanding and Application of Anaerobic Treatment Processes
    • Rongrong Mo
    • Wenjie Guo
    • Damien Batstone
    • Jacek Mąkinia
    • Yongmei Li
    2024

    Mathematical model is a valuable tool for prediction and recovery of resources and energy through anaerobic digestion of organic wastes. The International Water Association (IWA) Anaerobic Digestion Model No. 1 (ADM1) is the most commonly used structured anaerobic digestion model. However, as substrates become more complex and our deeper understanding of the anaerobic digestion mechanism, both systematic and specific modifications have been applied to ADM1. The modified models have provided a diverse range of applications besides anaerobic digestion processes, such as fermentation and biogas upgrading processes. A brief introduction to the original structure of ADM1 was presented, followed by extensions to extracellular and intracellular biochemical processes as well as physicochemical processes of the model. Then the introduction and modifications to kinetics (including inhibition functions) and stoichiometry are proposed. Furthermore, the applications of the model to a variety of anaerobic digestion scenarios are presented. Finally, the need for improvements in simulating anaerobic digestion and biogas upgrading processes, as well as the lack of full-scale application to other substrates besides sludge are highlighted. Future research perspectives are provided for the model development based on the in-depth understanding of the anaerobic treatment processes of different organic wastes and the recovery of valuable resources.

  • 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 Full text 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 Full text 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 Full text

    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 Full text 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 Full text 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 Full text 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.