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Politechniki Gdańskiej

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  • Zastosowanie fotogrametrii do tworzenia replik w obiektach zabytkowych
    • Anna Banaś
    • Maciej Niedostatkiewicz
    • Jacek Bramorski
    2025 Pełny tekst Inżynieria i Budownictwo

    Podczas użytkowania zabytków nieruchomych, którymi bardzo często są obiekty sakralne, nierzadko zachodzi konieczność stworzenia, znajdującego się wewnątrz obiektu, kopii oryginalnego elementu, w tym również będącego zabytkiem ruchomym. Realizacja wiernej kopii użytkowej, niezależnie od przyczyn konieczności jej wykonania, wymaga zastosowania techniki umożliwiającej stworzenie samej repliki. Kluczowymi wymaganiami dla techniki tworzenia replik zabytków ruchomych są szybkość ich wykonania, wysoka jakość oraz niski koszt realizacji. Istotnym zagadnieniem jest również uniwersalność samej metody, jak również jej dostępność oraz łatwość jej aplikacji. Wymagania te spełnia technika fotogrametrii, która w połączeniu z drukiem 3D umożliwia tworzenie w szybkim czasie wiernych replik zabytków ruchomych, w tym będących wyposażeniem obiektów sakralnych. Artykuł stanowi studium przypadku, w którym opisano i przedstawiono zastosowanie techniki fotogrametrii do realizacji wiernej kopii rzeźby sakralnej. W pracy omówiono zarówno wady, jak i zalety techniki fotogrametrycznej, określono istotne parametry umożliwiające stworzenie przestrzennego wydruku 3D na podstawie rekonstrukcji grupy standardowych zdjęć dwuwymiarowych.

  • 20 Jahre Bremer Kunststipendium
    • Krzysztof Wróblewski
    2024

    Seit 2004 vergeben die Bremische Bürgerschaft und die Bremer Heimstiftung gemeinsam ein Stipendium für bildende Künstler:innen aus den Partnerstädten Bremens. Das Bremer Kunststipendium wird von einer Jury maximal vier Mal jährlich für einen Zeitraum von jeweils drei Monaten vergeben. Das Stipendium beinhaltet freies Wohnen und Verpflegung in einer eigenständigen Atelier-Wohnung in der „Stiftungsresidenz Landhaus Horn“ der Bremer Heimstiftung. Die Bremische Bürgerschaft ergänzt dieses Angebot mit einem Zuschuss für die weiteren Kosten der Stipendiaten. Auch bietet sie ihnen die Möglichkeit einer Präsentation im Haus der Bürgerschaft. Weitere Institutionen der Stadt unterstützen die Stipendiaten, indem sie freien Eintritt in Veranstaltungen, Sammlungen und Ausstellungen gewähren. Das Bremer Kunststipendium bietet den Künstler:innen aus den Partnerstädten Bremens die Möglichkeit, die Stadt Bremen und ihre Institutionen kennenzulernen, berufliche Kontakte zu knüpfen, Anregungen für Ihre künstlerische Arbeit zu bekommen und freundschaftliche Begegnungen mit Kunstschaffenden und Kulturinteressierten vor Ort zu erleben. Es leistet damit einen Beitrag zum gegenseitigen Verstehen und der Verständigung zwischen den Partnerstädten. Anlässlich des Jubiläums sind ausgewählte Werke ehemaliger Stipendiat:innen aus allen Jahren und Partnerstädten im Haus der Bürgerschaft zu sehen. Zum Stipendium sind bisher drei Kataloge erschienen, siehe unter "Kunstprojekte".

  • 3-D Printable Metal-Dielectric Metasurface for Risley Prism-Based Beam-Steering Antennas
    • Md Yeakub Ali
    • Ali Lalbakhsh
    • Khushboo Singh
    • Sławomir Kozieł
    • Łukasz Gołuński
    2024 Pełny tekst IEEE Access

    A 3-D printable, planar, metal-dielectric metasurface-based, 2-D beam-steering system for aperture-type antennas is presented in this paper. This beam steering system, also known as the near-field meta-steering system, comprises two fully passive phase-gradient metasurfaces placed in the antenna’s nearfield region to steer the radiation beam. To address the non-uniform electric field phase of the aperture antenna, phase correction is also incorporated into the bottom metasurface placed on top of the antenna aperture in its near-field to enhance the far-field radiation of the antenna. Near-field phase transformation and phased array antenna theory concepts are applied to design the proposed metasurfaces. Two types of metal-dielectric unit cells are implemented to provide a phase range of 360◦ . The height of each metasurface is only 6.25 mm (0.25λ0), and the height of the whole system is only 1.56 λ0 at 12 GHz. The proposed beam steering system with a resonant cavity antenna can steer the beam to a maximum of ±44◦ in the elevation plane and 360◦ in the azimuth plane with only a 1.4 dB deviation in directivity over the full steering range.

  • 3D-Breast System for Determining the Volume of Tissue Needed for Breast Reconstruction
    • Gabriela Małyszko
    • Julia Czałpińska
    • Andżelika Janicka
    • Katarzyna Ostrowska
    • Mariusz Kaczmarek
    2024

    3D imaging systems can be used to effectively determine breast volumes for surgical applications. This article presents methods for surface reconstruction and volume determination based on the point cloud created by 3D imaging. Such a system would be used to accurately estimate breast volume in patients classified for breast reconstruction surgery at plastic surgery centers. To develop such a system, various methods of determining volume, based on images from the Intel D435i camera, were tested. In addition, an application and a measuring station tailored to clinical needs were developed

  • 9,10-Dioxoanthracenyldithiocarbamates effectively inhibit the proliferation of non-small cell lung cancer by targeting multiple protein tyrosine kinases
    • Mateusz Olszewski
    • Maryna Stasevych
    • Viktor Zvarych
    • Natalia Maciejewska
    2024 Pełny tekst JOURNAL OF ENZYME INHIBITION AND MEDICINAL CHEMISTRY

    Anthraquinones have attracted considerable interest in the realm of cancer treatment owing to their potent anticancer properties. This study evaluates the potential of a series of new anthraquinone derivatives as anticancer agents for non-small-cell lung cancer (NSCLC). The compounds were subjected to a range of tests to assess their cytotoxic and apoptotic properties, ability to inhibit colony formation, pro-DNA damage functions, and capacity to inhibit the activity of tyrosine kinase proteins (PTKs). Based on the research findings, it has been discovered that most active derivatives (i84, i87, and i90) possess a substantial capability to impede the viability of NSCLC while having mostly a negligible effect on the human kidney cell line. Moreover, the anthraquinones displayed pro-apoptotic and genotoxic attributes while blocking the phosphorylation of multiple PTKs. Collectively, our findings indicate that these derivatives may demonstrate promising potential as effective anticancer agents for lung cancer treatment.

  • A 0.5 V Nanowatt Biquadratic Low-Pass Filter with Tunable Quality Factor for Electronic Cochlea Applications
    • Jacek Jakusz
    • Waldemar Jendernalik
    2024 Pełny tekst Electronics

    A novel implementation of an analogue low-power, second-order, low-pass filter with tunable quality factor (Q) is presented and discussed. The filter feature is a relatively simple, buffer-based, circuit network consisting of eleven transistors operating in a subthreshold region. Q tuning is accomplished by injecting direct current into a network node, which changes the output resistance of the transistors and, as a result, modifies the filter network’s loss, and thus its Q. Q tuning is independent of a filter cut-off frequency (ω0). The filter, with a nominal ω0 of 1 kHz, was fabricated using a 0.18 μm CMOS technology, and features a Q range of 2–11, power consumption of up to 52 nW, and a 59 dB dynamic range when using a 0.5 V supply. The ω0 can be tuned from 0.5 to 2.5 kHz using a traditional method by changing the transistor transconductances, but this process partially affects the quality factor.

  • A business simulation method in educating architects
    • Michał Kwasek
    • Piotr Konwicki
    2024 World Transactions on Engineering and Technology Education

    In this article, the authors analyse the application of the business simulation method as a support tool in educating undergraduate architecture students. While running a fictional architectural practice, students learn about the role of an architect in the investment process and are introduced to economic aspects of running a small practice, including the importance of cash flow. They are also made aware about the importance of employability soft skills. The article is based on a simulation tested for several years in teaching classes during which students learn the practical aspects of managing their own architectural design practice, including cost management. A questionnaire survey has been used to assess both the prior knowledge of business principles among the students, as well as the effectiveness of this business simulation method as a learning tool for undergraduate students. Findings indicate that the applied method has improved the employability skills of graduates, in particular with respect to their actual knowledge of practical business skills, including legal, tax and financial issues.

  • A Case Study of Electric Vehicles Load Forecasting in Residential Sector Using Machine Learning Techniques
    • Sheetal Deshmukh
    • Atif Iqbal
    • Mousa Marzband
    • Mohammad Amir
    • Jarosław Guziński
    2024

    Electric vehicles (EVs) have been widely adopted to prevent global warming in recent years. The higher installation of Level-1 and Level-2 chargers in residential areas soon poses challenges to the distributed network. However, such challenges can be mitigated through the adoption of smart charging or controlled charging schemes. To facilitate the implementation of smart charging, accurate forecasting of EV charging demand in residential sectors is essential. This study focuses on utilizing machine learning (ML) techniques to predict EV charging demand based on charging data from Trondheim, Norway. A key contribution of this research is its systematic approach, providing a step-by-step implementation process of EV load forecasting using ML algorithms. By addressing the pressing issues surrounding the increasing demand for EV charging in residential areas, this paper offers valuable insights into sustainable transportation energy management. The results, obtained through Linear SVM, Wide Neural Network, Naive Bayes, and K-Nearest Neighbors algorithms implemented in MATLAB software, emphasize the effectiveness of ML techniques. This paper serves as an intelligent-based residential EV load forecast approach for researchers, policymakers, and industry professionals seeking effective strategies to mitigate the impact of EV charging on distributed networks.

  • A case study on the rotomolding behavior of black tea waste and bio-based high-density polyethylene composites: Do active compounds in the filler degrade during processing?
    • Mateusz Barczewski
    • Zaida Ortega
    • Paweł Piaskowski
    • Joanna Aniśko
    • Paulina Kosmela
    • Joanna Szulc
    2024 Composites Part C: Open Access

    This study verified the possibility of using waste material from the food industry (black tea) as functional filler of rotomolded biobased high-density polyethylene-based composites. As part of the experimental work, the influence of the materials preparation, i.e., dry blending versus twin-screw extrusion, on the effectiveness of the stabilizing antioxidant effect of the black tea was analyzed. The aim of the work was to verify whether, despite the initial degradation of the structure of the lignocellulosic filler, it would be possible to keep its antioxidant capacity and the stabilizing effect on the polyethylene matrix. The research showed that the filler allowed to stabilize the polymeric matrix during the rotomolding process, despite the appearance of numerous defects in the form of pores and a reduction in mechanical properties, more significant for composites prepared by dry blending, obtaining elastic modulus drops of about 50 %. Furthermore, the pre-processing step by melt mixing results in a significant improvement of the composite's thermo-oxidation stability, with increases in the oxidation induction time (OIT), from 25 min for the HDPE to over 70 min for composites with 5 % black tea, and improved rheological behavior, preventing the crosslinking of the matrix, indicative of its thermo-oxidative degradation. The tea brewing process caused the decrease of antioxidant activity of the filler; however, it did not significantly affect the antioxidant behavior, maintaining its influence on the polymeric matrix when the material is prepared via twin-screw compounding, which was proved to provide better stability, increasing OIT by approximately 20 min later when compared to dry blending.

  • A Closed Bipolar Electrochemical Cell for the Interrogation of BDD Single Particles: Electrochemical Advanced Oxidation
    • Anna Dettlaff
    • Joshua Tully
    • Georgia Wood
    • Deep Chauhan
    • Ben Breeze
    • Lijiang Song
    • Julie V. Macpherson
    2024 Pełny tekst ELECTROCHIMICA ACTA

    A closed bipolar electrochemical cell containing two conductive boron-doped diamond (BDD) particles of size  250 – 350 m, produced by high-pressure high-temperature (HPHT) synthesis, has been used to demonstrate the applicability of single BDD particles for electrochemical oxidative degradation of the dye, methylene blue (MB). The cell is fabricated using stereolithography 3D printing and the BDD particles are located at either end of a solution excluded central channel. Platinum wire electrodes placed in each of the two outer solution compartments are used to drive electrochemical reactions at the two BDD particles, which, under bipolar conditions do not require direct electrical connection to a potential source. Experiments using ultra high-performance liquid chromatography coupled with mass spectrometry (UHPLC-MS) show that the anodic pole BDD particle is able to electrochemically remove > 99% of the dye (originally present at 1  10-4 M) to undetectable UHPLC-MS products in 600 s. Monitoring of the time dependant change in MB peak area, from the UHPLC chromatograms, enables a pseudo first order rate constant of 0.54 min-1 to be determined for MB removal. Given the large scale at which such particles can be produced (tonnes), such data bodes well for scale up opportunities using HPHT-grown BDD particles, where the particles can be assembled into high surface area electrode formats.

  • A closer look at how the dispersive liquid–liquid microextraction method works. Investigation of the effect of solvent mixture composition on the quality and stability of the cloudy state
    • Serhii Zaruba
    • Michaela Ovšonková
    • Patrycja Makoś-Chełstowska
    • Vasil Andruch
    2024 Pełny tekst Frontiers in Chemistry

    The dispersive liquid–liquid microextraction (DLLME) is one of the most popular miniaturized extraction procedures. In this paper, the degree of dispersion and dispersion stability were studied with the aim to assess the correlations of these parameters with efficiency for the selected analytical application. The dependence between the degree of dispersion (cloudy state quality) and its stability obtained by various emulsification procedures, such as solvent-assisted emulsification (using various dispersive solvents) and mechanical emulsification (using auxiliary energies), is investigated and discussed. It was found out that the degree of dispersion depends on the type of emulsification procedure and decreases in the series: solvent-assisted (SA-) = ultrasound-assisted (UA-) > air-assisted (AA-) > vortex-assisted (VA-) emulsification. The emulsion stability depends on the degree of dispersion and there were 1810 and 2070 s for the most effective emulsification procedures, such us solvent-assisted and ultrasound-assisted emulsification, respectively. A comparison between the sensitivity of the analytical methods (using spectrophotometric determination of the anionic surfactants) and the degree of dispersion have been made. The sensitivity of the methods was ranked as follows: DLLME > UA-LLME > VA-LLME > AA-LLME.

  • A Compact Circularly Polarized Dielectric Resonator Antenna with MIMO Characterizations for UWB Applications
    • Shahid Khan
    • Owais Khan
    • Syed Ahson Ali Shah
    • Bilal Malik
    • Neelam Gohar
    • Sławomir Kozieł
    2024 Pełny tekst Scientific Reports

    Ultra-wideband (UWB) technology is extensively used in indoor navigation, medical applications, and Internet of Things (IoT) devices due to its low power consumption and resilience against multipath fading and losses. This paper examines a multiple input multiple-output (MIMO), circularly polarized (CP) dielectric resonator antenna (DRA) for UWB systems. Compact form factor, high gain, wideband response, improved port isolation, and high data rates are the major design goals. This arrangement consists of two identical DRAs with self-decoupled orthogonal orientations eliminating the need for extra decoupling structures while achieving an impressive maximum isolation of 43 dB. The corner-edge feeding mechanism of the extended feedline generates two orthogonal E-fields, facilitating circular polarization. Additionally, a printed hook-shaped stub integrated with the ground plane enhances CP performance across the two operating bands without altering the DR structure. Fabrication and testing exhibit an impressive 133% impedance bandwidth (2.5-14 GHz) with high port isolation. For a 3 dB axial ratio reference, the single-element design exhibits axial ratio bandwidths (ARBW) of 1.2 GHz (3.6–4.8 GHz) and 0.8 GHz (9.3–10.1 GHz). Remarkably, the MIMO configuration achieves a single ARBW of 0.5 GHz (3.9–4.4 GHz). Detailed investigations of MIMO performance parameters, including diversity gain (DG), envelope correlation coefficient (ECC), channel capacity loss (CCL), and total active reflection coefficient (TARC), underscore the design’s efficacy, making it a good choice for UWB wireless applications.

  • A comparative analysis of methods and tools for low impact development (LID) site selection
    • Khansa Gulshad
    • Michał Szydłowski
    • Andaleeb Yaseen
    • Rana Waqar Aslam
    2024 Pełny tekst JOURNAL OF ENVIRONMENTAL MANAGEMENT

    The site selection for Low Impact Development (LID) practices is a significant process. It affects the effectiveness of LID in controlling stormwater surface runoff, volume, flow rate, and infiltration. This research paper presents a comprehensive review of various methods used for LID site selection. It starts by introducing different methods and tools. Three main methods: index-based methods, GIS-based multi-criteria decision analysis (MCDA), and multi-criteria models and tools, are discussed in detail. A comparative analysis of these methods is then conducted based on ten different criteria. These criteria include the number of variables, data properties, the scale of analysis, benefits maximization approach, multi-attribute decision analysis, user-friendliness, community and stakeholder participation, and the validation methods. This comparison reveals limitations in each method. These include inadequate data availability and quality, lack of evaluation methods, comprehensive assessment criteria and spatial explicitness. These challenges underscore the need for future research to prioritize spatial clarity, broaden criteria, improve data quality through standardization, incorporate field visits and remote sensing for robust results, integrate big data, and develop web-based, open-source tools for enhanced accessibility. These key strategies provide valuable insights for advancing LID site selection methods.

  • A Comparative Study of Precision Surface Grinding Using Additively Fabricated Acrylonitrile–Butadiene–Styrene (ABS) Wheels with Continuous and Serrated Working Surfaces
    • Dawid Zieliński
    • Mariusz Deja
    • Mateusz Zator
    2024 Pełny tekst Materials

    Nowadays, high requirements imposed by mechanical components make it necessary to develop modern production methods. Additive technologies have been dynamically developing in recent years, showing many advantages associated with the fabrication of elements with complex ge-ometries and structures. One of the areas where the potential of additive technologies is exploited is the rapid tooling sector, which is based on the rapid production of tools and components used in various manufacturing methods. Currently, apart from industrial additive fabrication using metal and plastic powders, desktop and low-cost devices for additive manufacturing are gaining more and more importance in the production of functional elements. This paper presents the experi-mental results obtained from testing the micro-abrasive acrylonitrile–butadiene–styrene ABS tools fabricated by fused filament fabrication (FFF) technology and reinforced with SD 28/20 diamond grains uniformly distributed on the working surface of the tools after they were made. Precision surface grinding operations of 41Cr4 alloy steel were carried out on a portable five-axis CNC milling machine using wheels with continuous and serrated working surfaces. The tool with a serrated working surface enabled a more efficient material removal and produced a better surface finish. In particular, a low wear rate of both FFF-printed tools was confirmed after all experiments. Promising results were obtained, showing the potential for a wider industrial application of the tested tools.

  • A Comparison of Directional Beamforming Capabilities: High-Order Ambisonic Microphone vs. Shotgun Microphones
    • Paweł Perkowski
    • Paweł Pławczyk
    • Bartłomiej Mróz
    • Józef Kotus
    • Ewa Kujawska
    • Kamil Klonowski
    • Radosław Wierzbicki
    • Patryk Kosior
    2024 Pełny tekst

    This article presents the practical implications of the directional beamforming capability of a higher-order ambisonic microphone compared with popular shotgun microphones. Five different microphones were used in the study: Sennheiser MKH 416, Rode NTG2, Panasonic AG-MC200, Zoom SGH-6, and Zylia ZM-1 (ambisonic microphone). The results highlight the versatility of higher-order ambisonics for non-immersive use, which allows for beamforming in any direction even in post-production, as opposed to typical shotgun recordings. Measurements indicate that shotgun microphones show directional characteristics with apparent frequency-dependent directivity. The Zylia microphone has 5 beamforming modes, among which the S1 and S2 modes exhibit directional characteristics similar to shotgun microphones.

  • A Comprehensive Approach to Azo Dichlorotriazine Dye Treatment: Assessing the Impact of Physical, Chemical, and Biological Treatment Methods through Statistical Analysis of Experimental Data
    • Gamal K. Hassan
    • Montaser Y. Ghaly
    • Ghada E. Ahmed
    • Rehab M. Mohamed
    • Heba A. El-Gawad
    • Przemysław Kowal
    • Hussein Al-Hazmi
    • Ahmed A. Afify
    2024 Water

    This exploration investigates integrated treatment systems combining advanced oxidation processes (Fenton and photo-Fenton) with biological methods for the effective elimination of stubborn organic compounds in simulated textile wastewater composed of azo Dichlorotriazine dye. A comprehensive optimization of key process factors including catalyst dosage, hydrogen peroxide quantity, irradiation duration, etc. was systematically conducted for both Fenton and photo-Fenton processes to realize maximum COD and color removal. Under ideal conditions (0.4 g/L photocatalyst, 1 mL/L H2O2, and 75-Watt UV intensity for 60 min), the photo-Fenton process realized 80% COD elimination and complete decolorization, meeting industrial discharge limits without needing extra biological treatment. Statistical models correlating process parameters to treatment efficiency were developed, giving important design insights. For Fenton, effluent COD exceeded discharge thresholds, so a post-biological treatment using activated sludge was essential to comply with regulations. This integrated Fenton–biological scheme utilizes synergism between chemical and biological processes for enhanced overall treatment. Notable economic benefits were achieved by photo-Fenton over conventional UV-only and UV/H2O2 methods regarding energy consumption and operating costs. Overall, this pioneering work successfully proves integrated advanced oxidation–biological systems as a superior, sustainable alternative to traditional techniques for economically removing obstinate pollutants, such as azo Dichlorotriazine dye, as it is a simulated textile wastewater treatment used to satisfy environmental standards.

  • A Comprehensive Review: Applications of the Kozeny–Carman Model in Engineering with Permeability Dynamics
    • Maryam Rehman
    • Muhammad Bilal Hafeez
    • Marek Krawczuk
    2024 Pełny tekst ARCHIVES OF COMPUTATIONAL METHODS IN ENGINEERING

    In this review article, we investigate the dynamic nature of the Kozeny–Carman Model concerning permeability and its application in engineering contexts. Providing insights into the changing dynamics of permeability within mining, petroleum, and geotechnical engineering, among other engineering applications. While some are complex and require additional modifcations to be applicable, others are simple and still function in specifc situations. Therefore, having a thorough understanding of the most recent permeability evolution model would help engineers and researchers in fnding the right solution for engineering issues for prospects. The permeability evolution model Kozeny–Carman (KC) put forth by previous and current researchers is compiled in this paper, with a focus on its features and drawbacks

  • A COMPREHENSIVE REVIEW OF LIFE CYCLE ASSESSMENT AND ENERGY EFFICIENCY IN 3D PRINTING FOR CONSTRUCTION: CURRENT STATE, BENEFITS, LIMITATIONS, AND FUTURE OUTLOOK
    • Semahat Merve Top
    • Jan Cudzik
    2024 Pełny tekst Journal of Green Building

    The agenda of Industry 4.0 strongly affects design and construction at all its phases, and three-Dimensional Printing (3DP) is an essential part of it. The emerging technology has the potential to become a more valid and accepted form of construction. This research is based on a literature review regarding the relationships between the concepts of Life Cycle Assessment (LCA) and energy efficiency for 3DP in construction research to understand the developments. Systematic bibliometric and scientometric analyses are used as data analysis techniques to make a detailed comparison. The comparison allowed for assessing and determining the current state, benefits, limitations, and future outlook. Current research is based on insights examining materials first (80%), followed by walls (15%), buildings (11%), and 3DP technology (6%). The findings highlight that 3DP technology offers significant advantages in terms of time efficiency, reliability, ecological impact, and sustainability within the construction industry. However, several challenges, such as the complexity of material mixture content design, the lack of standardized 3DP materials and codes, and the limited availability of experts in the field, prevent its widespread adoption. Further advancement of 3DP requires the development of standards, policies, training and materials for its full implementation in the construction industry.

  • A Comprehensive Review of Reactive Flame Retardants for Polyurethane Materials: Current Development and Future Opportunities in an Environmentally Friendly Direction
    • Paulina Parcheta-Szwindowska
    • Julia Habaj
    • Izabela Krzemińska
    • Janusz Datta
    2024 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    Polyurethanes are among the most significant types of polymers in development; thesematerials are used to produce construction products intended for work in various conditions. Nowa-days, it is important to develop methods for fire load reduction by using new kinds of additivesor monomers containing elements responsible for materials’ fire resistance. Currently, additiveantipyrines or reactive flame retardants can be used during polyurethane material processing. Theuse of additives usually leads to the migration or volatilization of the additive to the surface of thematerial, which causes the loss of the resistance and aesthetic values of the product. Reactive flameretardants form compounds containing special functional groups that can be chemically bonded withmonomers during polymerization, which can prevent volatilization or migration to the surface of thematerial. In this study, reactive flame retardants are compared. Their impacts on polyurethane flameretardancy, combustion mechanism, and environment are described.

  • A Comprehensive Review on DC Fast Charging Stations for Electric Vehicles: Standards, Power Conversion Technologies, Architectures, Energy Management, and Cybersecurity
    • Gabriele Arena
    • Andrii Chub
    • Mykola Lukianov
    • Ryszard Strzelecki
    • Dmitri Vinnikov
    • Giovanni De Carne
    2024 Pełny tekst IEEE Open Journal of Power Electronics

    This paper aims to review the main research points regarding DC fast charging stations. At the beginning, the paper addresses an overview of DC fast charging standards, galvanic isolation, EV powertrain, and some examples of real DC fast chargers. This part highlights that DC fast chargers are usually connected to an AC network or microgrid, whereas DC microgrids would be a better choice to increase the charging efficiency and reduce the costs. However, the lack of standards in terms of protection and metering made their spread limited for the moment. Moreover, the paper describes the power converter topologies typically adopted in DC fast charging stations and emerging solutions to interface EVs with both 400 V and 800 V powertrains. Then, the paper explains the main architectural features of DC fast charging stations connected to DC networks or microgrids because of their potential to become the standard infrastructure in this field. Furthermore, the energy management strategies for DC fast charging stations are discussed, taking into account their relevant goals. Finally, cybersecurity issues of charging stations are covered, also considering their impact on grid and electric vehicle supply equipment, and providing a particular discussion regarding DC fast charging stations.

  • A comprehensive review on economic, environmental impacts and future challenges for photovoltaic-based electric vehicle charging infrastructures
    • Haseeb Rashid
    • Liu Ming Hua
    • Lyu Guanghua
    • Rija Hasan
    • Abdulrahman AlKaseem
    • Aqsa Ali
    • Syed Hadi Hussain Shah
    • Shoaib Shaikh
    • Arsalan Muhammad Soomar
    • Piotr Musznicki
    2024 Pełny tekst Frontiers in Energy Research

    In this paper, a comprehensive review of the impacts and imminent design challenges concerning such EV charging stations that are based on solar photovoltaic infrastructures is presented, which is based on state-of-the-art frameworks for PV-powered charging stations and the latest case studies. The main factors that are targeted in this review are the management of an EV charging system that is a composite of PV and public grid, as well as a charging system business model that can affect consumer behavior by charging at different rates and the best design infrastructure for a PV electric vehicle charging services. The economic, environmental, and social impacts caused by the installation of PVdriven charging infrastructures are also compared. Moreover, the framework for recently emerging vehicle-to-grid and vehicle-to-home services, as well as the integration of these frameworks, is discussed. Finally, survey results for future EV demand and its public acceptance are presented. Appertaining to these issues, the case studies highlight that EV transportation between parking lots and charging stations is necessary to make the best use of the available charging stations. Statistically, in this study, it was inferred that there are no limitations on the amount of EV battery capacity that can be stored, and users of EVs can charge in both slow and fast modes. Furthermore, V2G systems are not suitable for widespread industrial use. Moreover, finding solutions and overcoming numerous obstacles remain unaddressed issues, and the size of the EV industry must reach a certain level to make profitable sales of V2B, V2H, V2G, and other V2X systems. The collected statistics indicate that although respondents generally have a favorable opinion of the mobility applications powered by photovoltaic cells, it seems unlikely that they will use them anytime soon.

  • A Computational Analysis of the Proton Affinity and the Hydration of TEMPO and Its Piperidine Analogs
    • Abolfazl Shiroudi
    • Maciej Śmiechowski
    • Jacek Czub
    • Mohamed A. Abdel-Rahman
    2024 CHEMPHYSCHEM

    The study investigated the impact of protonation and hydration on the geometry of nitroxide radicals using B3LYP and M06-2X methods. Results indicated that TEMPO exhibited the highest proton affinity in comparison to TEMPOL and TEMPONE. Two pathways contribute to hydrated protonated molecules. TEMPO shows lower first enthalpies of hydration (ΔH1-M), indicating stronger H-bonding interactions, while TEMPONE shows higher values, indicating weaker interactions with H2O. Solvent effects affect charge distribution by decreasing their atomic charge. Spin density (SD) is primarily concentrated in the NO segment, with minimal water molecule contamination. Protonation increases SD on N-atom, while hydration causes a more pronounced redistribution for water molecules. The stability of the dipolar structure (>N•+-O-) is evident in SD redistributions. The frontier molecular orbital (FMO) analysis of TEMPONE reveals a minimum EHOMO-LUMO gap (EH-L), enhancing the piperidine ring's reactivity. TEMPO is the most nucleophilic species, while TEMPONE exhibits strong electrophilicity. Transitioning from NO radicals to protonated forms increases the EH-L gap, indicating protonation stabilizes FMOs. Increased water molecules make the molecule less reactive, while increasing hydration decreases this energy gap, making the molecule more reactive. A smaller EH-L gap indicates the compound becomes softer and more prone to electron density and reactivity changes.

  • A Concept of Thermal Effort for Heat-Induced Metal Plasticity
    • Waldemar Dudda
    • Piotr Józef Ziółkowski
    • Paweł Ziółkowski
    • Mateusz Bryk
    • Janusz Badur
    2024 Materials

    This paper proposes a new concept of material effort that considers heat-induced plasticity for heat-resistant steels. These steels indicate a strength differential effect, a stress shearness effect, pressure sensitivity, and other features. Therefore, a three-parameter, temperature-dependent yield function was presented and, next, analytically and geometrically researched. To validate the accuracy of the formulated yield function, experiments were conducted with the designed specimens to characterize the heat-resistant steels St12T and 26H2MF, which underwent simple shear, uniaxial strain tension, and compression tests. The yield function was calibrated by using a simple analysis. Next, the calibrated constitutive equations were used to numerically determine the load–stroke responses of different tests. The numerical analysis showed that the proposed yield function based on three parameters could accurately describe the thermal effort in various loading conditions from the onset of yielding to the ultimate rupture. Accordingly, the proposed yield function is recommended to model material strength under various thermal loading conditions.

  • A Data-Driven Comparative Analysis of Machine-Learning Models for Familial Hypercholesterolemia Detection
    • Tomasz Kocejko
    2024 Applied Sciences-Basel

    This study presents an assessment of familial hypercholesterolemia (FH) probability using different algorithms (CatBoost, XGBoost, Random Forest, SVM) and its ensembles, leveraging electronic health record data. The primary objective is to explore an enhanced method for estimating FH probability, surpassing the currently recommended Dutch Lipid Clinic Network (DLCN) Score. The models were trained using the largest Polish cohort of patients enrolled in an FH clinic, all of whom underwent genetic testing for FH-associated mutations. The initial dataset comprised over 100 parameters per patient, which was reduced to 48 clinically accessible features to ensure applicability in routine outpatient settings. To preserve balance, the data were stratified according to DLCN score ranges (<0–2>, <3–5>, <6–8>, and ≥9), representing varying levels of FH likelihood. The dataset was then split into training and test sets with an 80/20 ratio. Machine-learning models were trained, with hyperparameters optimized via grid search. The accuracy of the DLCN score in predicting FH was first evaluated by examining the proportion of patients with positive DNA tests relative to those with a DLCN score of 6 and above, the threshold for genetic testing. The DLCN score demonstrated an accuracy of approximately 40%. In contrast, the CatBoost model and its ensembles achieved over 80% accuracy. While the DLCN score remains a clinically valuable tool, its diagnostic accuracy is limited. The findings indicate that the ML models offer a substantial improvement in the precision of FH diagnosis, demonstrating its potential to enhance clinical decision making in identifying patients with FH.

  • A Deformation Sweep Testing Procedure to Evaluate Damage in Cold Recycled Material Mixtures
    • Andrea Graziani
    • Vittoria Grilli
    • Amedeo Virgili
    • Mariusz Jaczewski
    2024

    This chapter describes a new testing procedure to assess damage in cold recycled material mixtures. Specifically, stiffness modulus tests were performed at increasing deformation levels, with the objective of creating a gradual increase in damage. The succession of tests with increasing deformation was interspersed with tests at small deformation, with the objective of evaluating the damage gradually inflicted on the specimen. In the present research, the resilient stiffness modulus test was carried out in indirect tensile configuration at peak horizontal deformations from 2 μm to 15 μm. Cement–bitumen-treated materials specimens (80% of RAP, 4.0% of bitumen emulsion and 2% of cement) with three level of voids (12%, 14%, and 16%) were tested. The results showed that even small deformation levels lead to a significant reduction in stiffness, which can be interpreted as damage accumulation. Moreover, the dissipated energy approach shows that the damage is probably due to the failure of cementitious bonds.

  • A dissimilar welded joint of grade 92 steel and AISI 304L steel obtained using IN82 buttering and IN617 fller: relationship of microstructure and mechanical properties
    • Hardik Sanjay Surkar
    • Amit Kumar
    • Sachin Sirohi
    • Shailesh M. Pandey
    • Aleksandra Świerczyńska
    • Dariusz Fydrych
    • Chandan Pandey
    2024 Archives of Civil and Mechanical Engineering

    Unfavourable operating conditions of equipment in the energy industry resulting from high-temperature loads determine the need to use special materials and technological solutions, including welding procedures. In this article, buttering using IN82 (ERNiCr-3) consumables was proposed as a method to improve the weldability of grade 92 steel joined by the gas tungsten arc welding (GTAW) process with AISI 304L (IN617 fller). The microstructural characterization of samples was carried out using an optical microscope, scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy. The welded joint was further characterized by hardness, tensile (room temperature and at 620 °C temperature) and impact tests. Additionally, the fracture surfaces of tensile and impact tests were studied by SEM. Despite the confrmation of the difusion of alloying elements and signifcant changes in their concentration, which indicates the formation of Ti and Nb-rich phases, no welding imperfections were detected and favourable joint structures and acceptable properties were obtained. In particular, this concerns the limitation of the formation of brittle structures and the elimination of the untempered martensitic layer. At the same time, there was a signifcant decrease in the maximum hardness of heat-afected zone (HAZ) on the grade 92 steel side to a relatively low value of 310 HV, and a minimum tensile strength criterion of 600 MPa was achieved with a simultaneous increase in ductility (35% elongation) of the joint. Comparatively, when compared to a non-buttered welded joint, the joint produced with a buttering layer exhibited an increase in the elongation and impact toughness of the welded joint without any compromise in ultimate tensile strength (Sut). The fracture surface of tensile and impact-tested specimens was also characterized using SEM/EDS. Summarizing all the results, it can be concluded that the proposed GTAW procedure of grade 92 and 304L steels can be used in extreme working conditions, in ultra-supercritical power units or the petrochemical and chemical industries.

  • A Finite Element Approach for Wave Propagation in Elastic Solids
    • Arkadiusz Żak
    2024

    This book focuses on wave propagation phenomena in elastic solids modelled by the use of the finite element method. Although the latter is a well-established and popular numerical tool used by engineers and researchers all around the word the process of modelling of wave propagation can still be a challenge. The book introduces a reader to the problem by presenting a historical background and offering a broad perspective on the development of modern science and numerical methods. The principles of wave phenomena are clearly presented to the reader as well as the necessary background for understanding the finite element method, which is the following chapter of the book is viewed from the modeller point-of-view. Apart from the principles the book also addresses more advanced topics and problems including the use of the spectral-finite element method, the spline-based finite element method as well as the problems of undesired and hidden properties of discrete numerical models.

  • A framework for risk matrix design: A case of MASS navigation risk
    • Cunlong Fan
    • Jakub Montewka
    • Di Zhang
    • Zhepeng Han
    2024 ACCIDENT ANALYSIS AND PREVENTION

    Risk matrix, a tool for visualizing risk assessment results, is essential to facilitate the risk communication and risk management in risk-based decision-making processes related to new and unexplored socio-technical systems. The use of an appropriate risk matrix is discussed in the literature, but it is overlooked for emerging technologies such as Maritime Autonomous Surface Ships (MASS). In this study, a comprehensive framework for developing a risk matrix based on fuzzy Analytic Hierarchy Process (AHP) is proposed. In this framework, a linear function is defined where the risk index is treated as a response variable, while the probability and consequence indices are explanatory variables, with weights of these two indices representing their importance on given risk level. This significance is assessed by experts and quantified using AHP in interval type 2 fuzzy environment. A continuous risk diagram is then created and converted into a risk matrix that can be improved. To verify the feasibility of the proposed framework, a risk matrix is designed in the context of MASS grounding. The results show that the proposed approach is feasible. Our discussion results can provide new insights for the design of risk matrices and promote the management of MASS navigational risks.

  • A framework to analyse the probability of accidental hull girder failure considering advanced corrosion degradation for risk-based ship design
    • Krzysztof Wołoszyk
    • Floris Goerlandt
    • Jakub Montewka
    2024 RELIABILITY ENGINEERING & SYSTEM SAFETY

    Ship’s hull girder failure could result from maritime accident that can cause human life loss, environmental disaster, and major economic impacts. In risk-based ship design paradigm, accounting for rare phenomena (e.g. ship-ship collision or grounding) is important to provide safe and durable structure. In-service corrosion-induced hull degradation should be considered at the design stage, as it can significantly affect structural strength. The current study presents a novel framework to estimate the probability of ship hull girder failure, accounting for novel corrosion modelling techniques and accidental damage. The associated uncertainties are considered using statistical sampling from evidence-based distributions. A state-of-the-art deterministic model for ultimate strength calculation is applied using Monte Carlo simulation approach, resulting in the probability of hull failure through a reliability assessment. Wave and still-water bending moments are considered random variables. Two case studies of tanker ships with varying sizes are executed to show the applicability of the proposed framework. The results indicate that proper consideration of corrosion is of high importance, as ageing can significantly increase the probability of failure if accidental damage happens. Therefore, whereas future research and model refinement are discussed, the presented framework can serve for risk-based ship design tool and assess existing structures’ safety.

  • A gap waveguide-based mechanically reconfigurable phase shifter for high-power Ku-band applications
    • Ali Farahbakhsh
    • Davood Zarifi
    • Michał Mrozowski
    2024 Scientific Reports

    This paper presents a novel design of a low-loss, reconfgurable broadband phase shifter based on groove gap waveguide (GGW) technology. The proposed phase shifter consists of a folded GGW and three bends with a few pins forming the GGW and one bend attached to a movable plate. This movable plate allows for adjustments to the folded waveguide length, consequently altering the phase of electromagnetic waves. The advantage of GGW technology is that it does not require electrical contact between diferent parts of a structure. Therefore, it enables the moving parts to slide freely without electromagnetic energy leakage, resulting in improved insertion loss in high-power applications. In addition, in the proposed design, the position of the input and output waveguide ports of the phase shifter remains fxed, which is advantageous from a practical point of view. As shown by measurement and simulation results, there is nearly 37% impedance bandwidth with the highest insertion loss of 0.6 dB, and the developed device has a maximum phase shift of 770° at the center frequency of 13GHz. The phase shifter can be used for various radar and satellite applications that require phase control, such as beamforming networks and phased array antennas.

  • A green route for high-performance bio-based polyurethanes synthesized from modified bio-based isocyanates
    • Joanna Brzoska
    • Joanna Smorawska
    • Ewa Głowińska
    • Janusz Datta
    2024 INDUSTRIAL CROPS AND PRODUCTS

    The need for sustainability and a circular economy leads to the development of innovative greener materials and technologies. This paper is focused on a novel class of bio-based polyurethanes (PUs) synthesized with the use of bio-monomers including bio-based isocyanates. The novelty of this work is related to the usage of bio-based modified isocyanate via a two-step solvent-free synthesis of novel cast bio-based poly(ester-urethanes) and poly(ether-urethanes). The designed and prepared bio-based PUs were analysed in terms of their chemical structure, thermal stability, mechanical and thermomechanical properties. Fourier transform infrared spectroscopy confirmed the formation of urethane groups and allowed the calculation of the carbonyl index and the degree of phase separation. Differential scanning calorimetry and X-ray diffraction indicated the amorphous behavior of the obtained bio-based materials. It was established that not only the thermal stability but also the degradation steps depended on the structure of the hard segments and the phase separation between hard and soft segments. The modification of hard segments was also revealed in the results of thermomechanical and mechanical behavior of bio-PU which indicated a mixed phase structure.

  • A hierarchical observer for a non-linear uncertain CSTR model of biochemical processes
    • Mateusz Czyżniewski
    • Rafał Łangowski
    2024 Pełny tekst International Journal of Applied Mathematics and Computer Science

    The problem of estimation of unmeasured state variables and unknown reaction kinetic functions for selected biochemical processes modelled as a continuous stirred tank reactor is addressed in this paper. In particular, a new hierarchical (sequential) state observer is derived to generate stable and robust estimates of the state variables and kinetic functions. The developed hierarchical observer uses an adjusted asymptotic observer and an adopted super-twisting sliding mode observer. The stability of the proposed hierarchical observer is investigated under uncertainty in the system dynamics. The stability analysis of the estimation error dynamics is carried out based on the methodology associated with linear parameter-varying systems and sliding mode regimes. The developed hierarchical observer is implemented in the Matlab/Simulink environment and its performance is validated via simulation. The obtained satisfactory estimation results demonstrate high effectiveness of the devised hierarchical observer.

  • A high-gain gap waveguide-based 16 × 16 slot antenna array with low sidelobe level for mmwave applications
    • Davood Zarifi
    • Ali Sabbaghi Saber
    • Ashraf Uz Zaman
    2024 Scientific Reports

    This study presents the design of a high-gain 16 × 16-slot antenna array with a low sidelobe level (SLL) using a tapered ridge gap waveguide feeding network for Ka-band applications. The proposed antenna element includes four cavity-backed slot antennas. A tapered feeding network is designed and utilized for unequal feeding of the radiating elements. Ridge gap waveguide technology is used to reduce the feeding network loss and achieve a low-loss array antenna. The feed layer of the proposed antenna is coupled to a standard rectangular waveguide (WR-28) using a proper transition. The measured results show an impedance bandwidth of more than 17% over the frequency range of 27.5–32.6 GHz covering one of the standard vehicle-to-satellite band (29.4–31.0 GHz) and 5G mmWave N261 band (27.5– 28.35 GHz), a maximum gain of 28.9 dBi, and SLL lower than − 20 dB. Thanks to its high performance and desirable features, the proposed antenna shows potential for use in vehicular radar systems and high data rate mmWave communications.

  • A Highly Compact Split Ring Resonator Based Rectangular Dielectric Resonator Antenna with Multiband Characterization
    • Shahid Khan
    • Owais Khan
    • Kiran Raheel
    • Syed Ahson Ali Shah
    • Bilal Malik
    • Salahuddin Khan
    • Neelam Gohar
    • Sławomir Kozieł
    2024 Pełny tekst IEEE Access

    This work encompasses a novel highly compact Split Ring Resonator (SRR) based quad-band Dielectric Resonator Antenna (DRA) for 4G and 5G applications. The proposed antenna comprises of an extended rectangular feedline and a rectangular DR in combination with two SRRs. The DRA uses the extended rectangular microstrip feedline for providing better impedance matching and enhanced performance. Remarkably, the introduction of SRRs on either side of the feedline enables the DRA to resonate at four distinct frequency bands, i.e., 1.62 GHz, 3.03 GHz and 4.7 GHz and 6.56 GHz respectively. The two lower operating bands with narrow band response are due to SRRs while two upper bands with wide band characteristics are due to rectangular DR. The simulated performance of the rectangular DRA is validated through measurements, performed on a fabricated prototype. At the corresponding resonance frequencies, the suggested design exhibits -10 dB impedance bandwidths of 9.2%, 5%, 8.3%, and 5.6%. With a notable peak gain of 2.3 dBi and an efficiency of 93%, the suggested design has excellent radiation pattern stability. To the best of authors knowledge, this is the first design where SRRs are incorporated with rectangular DR to achieve multiband operations. The simulated and measured findings show a strong agreement, highlighting the SRR-based DRA appropriateness for multiband wireless applications (such as satellite television, radio astronomy, Bluetooth, WiFi, and 6G), while demonstrating its significant contribution to the field.

  • A learning community model: the Center for Innovative Education supporting academic didactics at Gdańsk University of Technology, Poland
    • Joanna Mytnik
    • Barbara Wikieł
    • Mariusz Kaczmarek
    2024 Global Journal of Engineering Education

    The current digital transformation requires academics to apply their pedagogical and technological skills to their teaching and professional development to address the newly emerging needs of the digital era. This study aims to analyse the operating model of the Center for Innovative Education (CIE) at Gdańsk University of Technology (Gdańsk Tech), Poland, as an incubator for professional development of academic staff at Gdańsk Tech, and outline the programmes carried out at the CIE. The focus is on systemic actions capable to elicit innovation at an organisational and personal level, including community building, higher education trend analyses, evidence-based professional training, designing new methods and tools for innovative teaching and appreciation programmes. The CIE’s offer extends to well-being support and providing measures against professional burnout. The establishment of the CIE enabled academic teachers at Gdańsk Tech to improve their professional competence and build a strong peer-learning community.

  • A Low-Profile 3-D Printable Metastructure for Performance Improvement of Aperture Antennas
    • Md Yeakub Ali
    • Ali Lalbakhsh
    • Sławomir Kozieł
    • Łukasz Gołuński
    • Foez Ahmed
    • Mohsen Asadnia
    2024 Pełny tekst Scientific Reports

    In order to increase the radiation performance of aperture-type antennas, this paper demonstrates a low-profile, planar, single-layer, three-dimensional (3-D) printable metastructure. The proposed hybridized metastructure is highly transparent as it is made out of novel hybrid meta-atoms having transmission coefficient magnitudes greater than -0.72 dB and fully complies with the near-field phase transformation principle. The hybridized design approach makes the metastructure planar, low-profile, light in weight, and compatible with additive printing technology. For the proof-of-concept, such metastructure is developed and numerically verified to enhance the radiation performance of a resonant cavity antenna (RCA). With the proposed metastructure, the peak directivity of the RCA is improved by 8.6 dBi (from 11.4 dBi to 20 dBi) at the operating frequency of 12.4 GHz. The aperture efficiency and 3-dB directivity bandwidth of the RCA with the metastructure are 41.46% and 16.5%, respectively. Using readily accessible thermoplastics or polymers and copper with cost-effective fused deposition modeling (FDM) 3-D printing technology, the proposed planar hybridized metastructure can be prototyped commercially.

  • A Low-Profile Metal-backed Dipole Loaded with Closely Coupled Arc-shaped Open Stubs for On-metal Tag Design with Wide Frequency Tuning Capability
    • Fuad Erman
    • Sławomir Kozieł
    • Eng-Hock Lim
    • Leifur Leifsson
    • Effariza Hanafi
    • Muthukannan Murugesh
    2024 IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION

    This research has presented a single-layer metal-backed dipole antenna, which consists of a feedline loaded with two pairs of closely-coupled arc-shaped open stubs, for designing a metal-mountable tag that features tuning capability over a wide range of frequency. Here, the stubs can generate sufficient inductive reactance for bringing down the tag resonant frequency tunable in both the regulated UHF RFID passbands (North American (NA) and Lower European (LEu) standards). Adjusting the stubs’ length can be utilized as a simple and effective tuning mechanism, enabling broadband frequency adjustment in between the two major spectra in a straightforward manner, while maintaining a maximum power transmission coefficient (τ=1). In addition, the proposed antenna structure is easy to construct. The tuning mechanism has enabled the antenna to match well with any commercial RFID chips, and it does not require the use of any external lumped components or shorting elements (vias or stubs). The proposed tag can be easily fabricated using an inexpensive flexible polytetrafluoroethylene (PTFE) substrate, which is broadly adopted by the RFID industry. Stable read performance is achievable, providing freedom of frequency tuning without the need to modify the radiator structure. The volume of the tag is reasonably small:   (28)2  1.5 mm3. It has a measured detection distance is 9.75 m (4 W EIRP) on metal surface in the NA RFID passband while 8.41 m (3.24 W EIRP) in the LEu passband.

  • A Machine Learning Approach for Estimating Overtime Allocation in Software Development Projects
    • Hammed Mojeed
    • Rafał Szłapczyński
    2024 Pełny tekst

    Overtime planning in software projects has traditionally been approached with search-based multi-objective optimization algorithms. However, the explicit solutions produced by these algorithms often lack applicability and acceptance in the software industry due to their disregard for project managers' intuitive knowledge. This study presents a machine learning model that learns the preferred overtime allocation patterns from solutions annotated by project managers and applied to four publicly available software development projects. The model was trained using 1092 instances of annotated solutions gathered from software houses, and the Random Forest Regression (RFR) algorithm was used to estimate the PMs' preference. The evaluation results using MAE, RMSE, and R2 revealed that RFR exhibits excellent predictive power in this domain with minimal error. RFR also outperformed the baseline regression models in all the performance measures. The proposed machine learning approach provides a reliable and effective tool for estimating project managers' preferences for overtime plans.

  • A machine learning approach to classifying New York Heart Association (NYHA) heart failure
    • Krystian Jandy
    • Paweł Weichbroth
    2024 Pełny tekst Scientific Reports

    According to the European Society of Cardiology, globally the number of patients with heart failure nearly doubled from 33.5 million in 1990 to 64.3 million in 2017, and is further projected to increase dramatically in this decade, still remaining a leading cause of morbidity and mortality. One of the most frequently applied heart failure classification systems that physicians use is the New York Heart Association (NYHA) Functional Classification. Each NYHA class describes a patient’s symptoms while performing physical activities, delivering a strong indicator of the heart performance. In each case, a NYHA class is individually determined routinely based on the subjective assessment of the treating physician. However, such diagnosis can suffer from bias, eventually affecting a valid assessment. To tackle this issue, we take advantage of the machine learning approach to develop a decision-tree, along with a set of decision rules, which can serve as additional blinded investigator tool to make unbiased assessment. On a dataset containing 434 observations, the supervised learning approach was initially employed to train a Decision Tree model. In the subsequent phase, ensemble learning techniques were utilized to develop both the Voting Classifier and the Random Forest model. The performance of all models was assessed using 10-fold cross-validation with stratification.The Decision Tree, Random Forest, and Voting Classifier models reported accuracies of 76.28%, 96.77%, and 99.54% respectively. The Voting Classifier led in classifying NYHA I and III with 98.7% and 100% accuracy. Both Random Forest and Voting Classifier flawlessly classified NYHA II at 100%. However, for NYHA IV, Random Forest achieved a perfect score, while the Voting Classifier reported 90%. The Decision Tree showed the least effectiveness among all the models tested. In our opinion, the results seem satisfactory in terms of their supporting role in clinical practice. In particular, the use of a machine learning tool could reduce or even eliminate the bias in the physician’s assessment. In addition, future research should consider testing other variables in different datasets to gain a better understanding of the significant factors affecting heart failure.

  • A magnetic imprinted polymer nano-adsorbent with embedded quantum dots and mesoporous carbon for the microextraction of triazine herbicides
    • Nurhasima Phirisi
    • Justyna Płotka-Wasylka
    • Opas Bunkoed
    2024 JOURNAL OF CHROMATOGRAPHY A

    A magnetic molecularly imprinted polymer (MMIP) adsorbent incorporating amino-functionalized magnetite nanoparticles, nitrogen-doped graphene quantum dots and mesoporous carbon (MIP@MPC@NGQDs@ Fe3O4–NH2) was fabricated to extract triazine herbicides from fruit juice. The embedded magnetite nanoparticles simplified the isolation of the adsorbent from the sample solution. The N-GQDs and MPC enhanced adsorption by affinity binding with triazines. The MIP layer provided highly specific recognition sites for the selective adsorption of three target triazines. The extracted triazines were determined by high-performance liquid chromatography (HPLC) coupled with diode-array detection (DAD). The developed method exhibited linearity from 1.5 to 100.0 μg L 1 with a detection limit of 0.5 μg L 1. Recoveries from spiked fruit juice samples were in the range of 80.1– 108.4 %, with a relative standard deviation of less than 6.0 %. The developed MMIP adsorbent demonstrated good selectivity, high extraction efficiency, ease of fabrication and use, and good stability.

  • A magnetic stir bar sorbent of metal organic frameworks, carbon foam decorated zinc oxide and cryogel to enrich and extract parabens and bisphenols from food samples
    • Sirintorn Jullakan
    • Natnaree Rattanakunsong
    • Justyna Płotka-Wasylka
    • Opas Bunkoed
    2024 JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES

    A porous composite magnetic stir bar adsorbent was fabricated for the extraction and enrichment of parabens and bisphenols from selected beverage samples. The adsorbent comprised a metal organic framework, carbon foam decorated zinc oxide and magnetic nanoparticles embedded in polyvinyl alcohol cryogel. The porous composite stir bar adsorbent could adsorb parabens and bisphenols via hydrogen bonding, π-π and hydrophobic interactions. In the best conditions, linearity was good from 5.0 to 200.0 µg/L for methyl paraben, ethyl paraben and bisphenol A and from 10.0 to 200.0 µg/L for bisphenol B and butyl paraben. Limits of detection ranged from 1.5 to 3.0 µg/L. The developed composite stir bar was successfully applied to extract and determine parabens and bisphenols in fruit juice, beer and milk. Recoveries ranged from 89.5 to 99.5 % with RSDs lower than 6 %. The developed sorbent and new methodology were evaluated in terms of its green character with satisfactory results.

  • A Mammography Data Management Application for Federated Learning
    • Dmytro Tkachenko
    • Magdalena Mazur-Milecka
    2024

    This study aimed to develop and assess an application designed to enhance the management of a local client database consisting of mammographic images with a focus on ensuring that images are suitably and uniformly prepared for federated learning applications. The application supports a comprehensive approach, starting with a versatile image-loading function that supports DICOM files from various medical imaging devices and settings. It also aims to standardize the labeling and pre-processing of new images, statistical analysis and data visualization of mammographic images across all participating healthcare units. Initial image preprocessing is significantly enhanced through the use of Wiener and CLAHE filters, aimed at reducing noise and improving contrast, respectively, to ensure the highest quality of images for diagnostic purposes. Further refinement in the preprocessing pipeline is achieved with a U-Net model, trained on publicly available databases, which excels in segmenting the breast tissue from images, thereby eliminating irrelevant background and artifacts. This meticulous preparation of images not only standardizes data quality across multiple medical institutions but also facilitates collaborative model training within federated learning frameworks. The program allows for the review of images and their metadata, enables labeling of images with the ability to mark regions of interest (ROI), and utilize a pre-trained model for preliminary BI-RADS classification. A notable addition to the application is the integration of functionalities, thanks to the implementation of Grad-CAM model, designed to elucidate the decision-making processes of deep learning models. This integration further enriches the application's utility in supporting diagnostic and analytical tasks in mammography, providing clear insights into the interpretive reasoning behind model predictions.

  • A method to synthesise groove cam Geneva mechanisms with increased dwell period
    • Viacheslav Pasika
    • Pavlo Nosko
    • Oleksii Nosko
    • Oleksandr Bashta
    • Volodymyr Heletiy
    • Volodymyr Melnyk
    2024 Pełny tekst PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE

    The present study develops a method to synthesise the groove cam Geneva mechanism with increased dwell period. The main condition of the synthesis is to provide the desired law of motion of the wheel. Additional synthesis conditions are the limitation of the maximum pressure angle and the limitation of the minimum curvature radius of the cam profile. Unlike the conventional Geneva mechanisms, the synthesised groove cam Geneva mechanisms enable motion of the wheel due to an arbitrarily specified law, double locking of the wheel at its dwell-to-motion and motion-to-dwell transitions, absence of soft impacts in the extreme positions. The analysis shows that for the cycloidal law of motion, number of slots in range 3 to 15 and additional dwell coefficient in range 0 to 0.7, the operating time coefficient can be provided in wide range from 0.053 to 0.765. The effectiveness of the method is illustrated by numerical examples.

  • A methodology for ultimate strength assessment of ship hull girder accounting for enhanced corrosion degradation modelling
    • Krzysztof Wołoszyk
    • Floris Goerlandt
    • Jakub Montewka
    2024 MARINE STRUCTURES

    The presented work shows a methodology for the ultimate strength assessment of a ship hull, considering enhanced corrosion modelling. The approach is based on the classical Smith method. However, the recent findings regarding the impact of corrosion degradation on ultimate strength are incorporated. To this end, the stress–strain relationships for particular elements composing ship hull cross-section are modified using a specially developed correction factor. The proposed approach is validated with experimental results of the corroded box girders available in the literature, showing very good agreement. Further, a case study of a VLCC tanker ship is presented, and a comparison between contemporary and enhanced corrosion degradation modelling in terms of resulting ultimate strength is presented. The results indicate that the currently used method may significantly overestimate the hull’s structure capacity, especially considering the long exploitation period. Thus, current approaches lead to a non-conservative assessment of the ship hull girder’s ultimate strength, potentially increasing the risk of failure. It is therefore recommended to further investigate the proposed method, especially in the context of risk-based ship design approaches and holistic maritime transportation risk management.

  • A model for agribusiness supply chain risk management using fuzzy logic. Case study: Grain route from Ukraine to Poland
    • Ievgen Medvediev
    • Dmitriy Muzylyov
    • Jakub Montewka
    2024 Pełny tekst TRANSPORTATION RESEARCH PART E-LOGISTICS AND TRANSPORTATION REVIEW

    In order to establish new logistics routes, it is necessary to address several technical and organizational issues, among others. One of the most important criteria for evaluating the performance of a supply chain is the delivery time, proactive consideration of potential hazards and associated uncertainties that may occur along the route. However, the existing solutions are often passive and reactive, based on statistics, thus not leaving much room for proactive risk mitigation measures. Therefore, there is a need for a foreseeing modern approach to account for the impact of anticipated hazards on delivery time. The aim of this study is to develop a model for determining delivery time considering expected risk factors (RF), based on mathematical tools of fuzzy logic and actual background knowledge elicited from the literature and experts. The paper identifies primary technical and operational hazards that occur during loading and transport and converts them into risk factors. The risk factors are then quantified and fed into a fuzzy model developed with the Matlab Fuzzy Logic Toolbox and assembled in the Simulink environment. The application of the model is demonstrated in three case studies reflecting three potential grain supply chains (SC) from Ukraine to Poland: classical transport by rail grain hoppers (SC1); transport by containers on railway platforms (SC2); transport by bulk grain trucks (SC3). The resulting travel time for the analysed SCs is between 49 and 71 hours for SC1, between 45 and 62 hours for SC2 and between 42 and 62 hours for SC3. In addition, the outliers of the travel time values beyond the 1.5 quantiles were defined according to the uncertainty band. The results of the fuzzy model were compared with the results of the deterministic approach in the concurrent validation and a good agreement was found. This proves the appropriateness of the fuzzy model calculations and the possibility of using alternative SCs in grain delivery. The main benefit of the proposed model is a new universal tool based on a holistic and active approach to risk assessment using fuzzy logic.

  • A Model Modification for a Microturbine Set with Partial Admission Stages
    • Wojciech Włodarski
    • Marian Piwowarski
    2024 ENERGIES

    The vapour microturbine set’s mathematical model has been updated to consider the partial admission of turbine stages. Experimental data from two distinct microturbine sets were used to verify the model. The model of the microturbine set was tested under varying operating conditions. Examples of a comparison between the experimental results and simulations are presented and analysed. It has been shown that, when simulating the off-design operation of multistage microturbines, not taking into account power losses due to partial admission may lead to significantly incorrect results. This conclusion does not apply to single-stage microturbines.

  • A modified DC Hebb–Wagner polarization method for determining the partial protonic electrical conductivity in mixed-conducting BaGd0.3La0.7Co2O6−δ
    • Tadeusz Miruszewski
    • Ragnar Strandbakke
    • Kacper Dzierzgowski
    • Iga Szpunar
    • Aleksandra Mielewczyk-Gryń
    • Sebastian Wachowski
    • Maria Gazda
    2024 Journal of Materials Chemistry A

    In this work, partial protonic conductivity in mixed conducting (BZCY721) and BaGd0.3La0.7Co2O6−d (BGLC137) was studied. For this purpose, a modified DC Hebb–Wagner polarization method was used. A four-wire type of galvanic cell as well as a suitable calculation model was applied. The method was validated using proton conducting electrolyte – BaZr0.7Ce0.2Y0.1O3−d – as a reference material. For the first time, protonic partial conductivity in BaGd0.3La0.7Co2O6−d was determined. It was found that at 600 °C its total conductivity was ∼550 S cm−1, whereas the partial protonic conductivity under the same conditions was 4.4 × 10−5 S cm−1 (protonic transference number of 7.6 × 10−8). Therefore, the proposed measurement cell and the applied model allowed for the determination of a minor protonic conductivity in the BGLC137 electronic conductor.

  • A multiparameter simulation-driven analysis of ship response when turning concerning a required number of irregular wave realizations
    • Przemysław Krata
    • Mateusz Gil
    • Tomasz Hinz
    • Paweł Kozioł
    2024 OCEAN ENGINEERING

    The growing implementation of Decision Support Systems on modern ships, digital-twin technology, and the introduction of autonomous vessels cause the marine industry to seek accurate modeling of vessel response. Despite the contemporary 6DOF models can be used to predict ship motions in irregular waves, the impact of their stochastic realization is usually neglected and remains under-investigated. Especially in the case of turning, differences arising from the stochastic representation of the waves may result in excessive ship motions or even stability failure during maneuver execution. Therefore, in this study, statistical distributions of maximum amplitudes of roll, pitch, and lateral acceleration calculated in two representative locations on board a passenger vessel were analyzed concerning stochastic wave realization and existing extremes. The research utilized 6DOF simulation data and numerous realizations of the irregular wave with random phases of its components. Furthermore, the required number of wave realizations allowing for capturing the actual ranges of ship response at an assumed confidence level has been determined and analyzed. Ultimately, the results were compared in the safety-critical cases concerning various wave and operational conditions. The outcome of this study may be found useful by all parties involved in developing maritime autonomous systems and modeling ship motions.

  • A multiparameter simulation-driven analysis of ship turning trajectory concerning a required number of irregular wave realizations
    • Mateusz Gil
    • Przemysław Krata
    • Paweł Kozioł
    • Tomasz Hinz
    2024 OCEAN ENGINEERING

    In times of progressive automation of the marine industry, accurate modeling of ship maneuvers is of utmost importance to all parties involved in maritime transportation. Despite the existence of modern collisionavoidance algorithms using 6DOF motion models to predict ship trajectories in waves, the impact of stochastic realization of irregular waves is usually neglected and remains under-investigated. Therefore, herein, this phenomenon and its impact were investigated in the case study of the passenger ship’s turning. To this end, statistical and spatiotemporal distributions of ship positions and corresponding trajectory parameters were analyzed. This was made using massive 6DOF simulation data with particular attention to the observed extremes. Additionally, the minimum number of wave realizations has been determined using different methods in various simulation scenarios and afterward compared concerning parameters’ impact and existing dependencies. The results indicate that for simulated scenarios, the required number of wave realizations should be at least 20, but in rough seas should be greater than 30. These values satisfy an acceptable and operationally reasonable error limit reaching 15% of the ship’s length overall. The obtained results may be of interest to autonomous ship developers, scholars, and marine industry representatives working on intelligent collision-avoidance solutions and ship maneuvering models.

  • A New Approach of Solidification Analysis in Modular Latent Thermal Energy Storage Unit Based on Image Processing
    • Rafał Andrzejczyk
    • Muhammad Saqib
    • Michał Rogowski
    2024 Pełny tekst APPLIED THERMAL ENGINEERING

    The solidification process of RT18HC in a cylindrical shell and tube storage unit has been studied using a new methodology based on image processing. The main idea of the algorithm is to label the region of solidification and use statistical functions to calculate the dimensions of the solidification front over time. Said analysis includes two methods. The first method is to measure the solid fraction changes during solidification. The novelty of this method, as compared to other literature findings, is that pre-processing and calculation process occurs automatically via a calculation algorithm. This method is used to calculate the solid fraction of RT18HC which is reported to be a bit fast at the beginning that 40 % of its volume solidified in 1000 s while the rest of the process is completed in almost 6500 s. The second method is used to measure and calculate the thickness of the solid front by using image processing. This method’s error is calculated to be less than 7% throughout the entire process. The second method also acts as an experimental database of front thickness to use in a novel, simplified, semi-theoretical model proposed to calculate the solid front thickness as a function of time in this paper. It is also worth presenting solution extended by a general definition of thermal resistance for a cylindrical partition. The above study will enable the development of an enhanced and optimized model for complex geometries based on image processing techniques in the future. It will also allow the investigation of both processes i.e. solidification and melting alongside other influencing parameters such as the geometry of the storage unit in future.