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Gdańsk University of Technology

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  • Exploring the Benefits, Challenges, and Opportunities of Collaborative Business Intelligence
    • Paweł Weichbroth
    • Jozef Zurada
    • Celina Olszak
    2024 Full text

    In traditional business intelligence (BI) settings, the collective decision-making process is often hindered by the absence of knowledge and expertise exchange among various stakeholders, as well as lack of information sharing. The study delves into the concept of Collaborative BI, which aims to overcome these limitations by promoting collaboration, business networking, knowledge sharing, and improved communication among stakeholders. Based on a systematic literature review, the study explores the notion of Collaborative BI, formulates its definition, and reports on its challenges, benefits, and limitations. It also provides an insightful overview of Collaborative BI landscape and multiple advantages it can deliver to modern business organizations. The study also acknowledges potential threats to the validity of its findings due to the limited scope of the literature review. Finally, the study highlights the need for further research to address the limitations and expand our understanding of the CBI field

  • Exploring the technological dimension of Autonomous sensory meridian response-induced physiological responses
    • Sahar Seifzadeh
    • Bożena Kostek
    2024 PeerJ

    Background In recent years, the scientific community has been captivated by the intriguing Autonomous sensory meridian response (ASMR), a unique phenomenon characterized by tingling sensations originating from the scalp and propagating down the spine. While anecdotal evidence suggests the therapeutic potential of ASMR, the field has witnessed a surge of scientific interest, particularly through the use of neuroimaging techniques including functional magnetic resonance imaging (fMRI) as well as electroencephalography (EEG) and physiological measures such as eye tracking (Pupil Diameter), heart rate (HR), heartbeat-evoked potential (HEP), blood pressure (BP), pulse rates (PR), finger photoplethysmography (PPG), and skin conductance (SC). This article is intended to provide a comprehensive overview of technology’s contributions to the scientific elucidation of ASMR mechanisms. Methodology A meticulous literature review was undertaken to identify studies that have examined ASMR using EEG and physiological measurements. The comprehensive search was conducted across databases such as PUBMED, SCOPUS, and IEEE, using a range of relevant keywords such as ‘ASMR’, ‘Autonomous sensory meridian response’, ‘EEG’, ‘fMRI’, ‘electroencephalography’, ‘physiological measures’, ‘heart rate’, ‘skin conductance’, and ‘eye tracking’. This rigorous process yielded a substantial number of 63 PUBMED and 166 SCOPUS-related articles, ensuring the inclusion of a wide range of high-quality research in this review. Results The review uncovered a body of research utilizing EEG and physiological measures to explore ASMR’s effects. EEG studies have revealed distinct patterns of brain activity associated with ASMR experiences, particularly in regions implicated in emotional processing and sensory integration. In physiological measurements, a decrease in HR and an increase in SC and pupil diameter indicate relaxation and increased attention during ASMR-triggered stimuli. Conclusions The findings of this review underscore the significance of EEG and physiological measures in unraveling the psychological and physiological effects of ASMR. ASMR experiences have been associated with unique neural signatures, while physiological measures provide valuable insights into the autonomic responses elicited by ASMR stimuli.

  • Exploring the trends in flux-cored arc welding: scientometric analysis approach
    • Aleksandra Świerczyńska
    • Balázs Varbai
    • Chandan Pandey
    • Dariusz Fydrych
    2024 Full text INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY

    Flux-cored arc welding (FCAW) is a universal group of welding methods in terms of the scope of application and automation possibilities, the share of which in various industries in many countries is still increasing. The paper presents the results of bibliographic analyses (scientometric analysis with the use of VOSviewer, Bibliometrix and CitNetExplorer tools) of a data set of 993 publications indexed in the Web of Science database on the subject of FCAW for all types of flux-cored wires. An objective and unbiased approach to analysis resulted in a relatively neutral assessment of the state of knowledge in the field of FCAW and allowed for the identification of research directions carried out in the world, the dynamics of their changes as well as research gaps and needs. The scientometric analysis approach provided a holistic picture of the development of FCAW over the last 58 years, pointing to the geographical areas where this process has been and is most intensively researched, the agencies funding this research, the most active research teams, as well as the journals that have most often published articles on this topic. The most current research directions in relation to FCAW include underwater welding, hardfacing and cladding purposes, health and safety issues, and more general topic: properties and weldability of ferrous alloys. However, among the most urgent research needs the following topics: fatigue analysis of welded joints, environmental degradation of flux-cored wires, properties and weldability of nickel alloys, development of hybrid and combined welding procedures can be listed.

  • Exposure to cooking emitted volatile organic compounds with recirculating and extracting ventilation solutions
    • Wojciech Wojnowski
    • Aileen Yang
    • Tomas Mikoviny
    • Armin Wisthaler
    • Kari Thunshelle
    2024 Full text BUILDING AND ENVIRONMENT

    Energy-efficient urban development leads to the compact design of apartments. Recirculating ventilation solutions are an attempt to minimize the space required for ventilation ducting, but more data on their performance are needed. Cooking is a major source of volatile organic compounds (VOCs) emissions. It is necessary to assess how well recirculating kitchen hoods perform in reducing the residents' exposure to cooking fumes compared to extracting hoods, and what airflow rates assure good removal efficiency. We have monitored the occupant exposure to several VOCs generated during the cooking of a model meal under different ventilation scenarios in a purpose-built test kitchen resembling the layout of a modern, open-space apartment. Time-resolved VOC emission profiles were measured using a proton transfer reaction time-of-flight mass spectrometer. The performance of activated carbon sorption-based filters for recirculating kitchen hoods in the removal of selected VOCs was also assessed. Alcohols, particularly ethanol, dominated emissions from cooking a typical Norwegian meal, but they also included acetaldehyde, acetone, carboxylic acids, and trimethylamine, among others. The use of recirculating kitchen hoods led to, on average, higher occupant exposure to VOCs compared to extracting kitchen hoods during and after cooking. This was in part due to the poor ethanol removal efficiency of the recirculating ventilation's air filters.

  • Extending loophole-free nonlocal correlations to arbitrarily large distances
    • Anubhav Chaturvedi
    • Giuseppe Viola
    • Marcin Pawłowski
    2024 Full text npj Quantum Information

    Quantum theory allows spatially separated observers to share nonlocal correlations, which enable them to accomplish classically inconceivable information processing and cryptographic feats. However, the distances over which nonlocal correlations can be realized remain severely limited due to their high fragility to noise and high threshold detection efficiencies. To enable loophole- free nonlocality across large distances, we introduce Bell experiments wherein the spatially separated parties randomly choose the location of their measurement devices. We demonstrate that when devices close to the source are perfect and witness extremal nonlocal correlations, such correlations can be extended to devices placed arbitrarily far from the source. To accommodate imperfections close to the source, we demonstrate an analytic trade-off: the higher the loophole-free nonlocality close to the source, the lower the threshold requirements away from the source. We utilize this trade-off and formulate numerical methods to estimate the critical requirements of individual measurement devices in such experiments.

  • Extraction pathways and purification strategies towards carminic acid as natural-based food colorant: A comprehensive review
    • Dante Ferreyra-Suarez
    • Leonardo Paredes-Vargas
    • Seid Mahdi Jafari
    • Octavio García-Depraect
    • Roberto Castro Munoz
    2024 ADVANCES IN COLLOID AND INTERFACE SCIENCE

    As a current trend of fabricating healthier products, food manufacturing companies seek for natural-based food colorant aiming to replace the synthetic ones, which apart from meeting sensorial and organoleptic aspects, they can also act as health promoters offering additional added value. Carminic acid is a natural based food colorant typically found in several insect taxa. However, there are current approaches which pursue the production of this natural pigment via biotechnological synthesis. To date, this colorant has been intensively applied in the manufacture of several food items. Unfortunately, one of the main limitations deals with the establishment of the right protocol of extraction and purification of this component since there is no report analyzing the main extraction techniques for obtaining carminic acid. Therefore, this review, for the first time, comprehensively analyzes the ongoing strategies and protocols proposed by scientists towards either extraction or purification of carminic acid from its origin source, and from biotechnological systems. Emphasis has been focused on the main findings dealing with extraction techniques and the relevant insights in the field. A detailed discussion is provided on the advantages and drawbacks of the reported extraction and purification methods, main solvents used and their key interactions with target molecules.

  • Extra-curricular project-oriented education in optoelectronics in the Faculty of Electronics, Telecommunications and Informatics at Gdańsk University of Technology, Poland
    • Adam Mazikowski
    • Paweł Wierzba
    2024 Global Journal of Engineering Education

    Project-oriented education constitutes a key part of the curriculum in the Faculty of Electronics, Telecommunications and Informatics of Gdańsk University of Technology (Gdańsk Tech), Poland. Students on the Engineer and Master of Science level studies take part in several projects, both individually and in teams. In addition to compulsory activities, students have the opportunity to take part in the activities of student scientific chapters of international professional societies, such as SPIE or Optica, as well as in scientific research projects, in particular financed by Gdańsk Tech in the framework of its Technetium and Plutonium programmes. In this article, the authors present the framework and implementation of these projects. Opportunities, limitations and threats in the projects in optoelectronics are discussed, based on selected cases. Results of example projects are outlined, and modifications to the process are formulated.

  • Fabrication of high-density nitrogen-vacancy (NV) center-enriched diamond particles through methyl trityl amine (C20H19N) seeding
    • Srinivasu Kunuku
    • Mateusz Ficek
    • Saravanan Sengottuvel
    • Jacek Ryl
    • Mariusz Mrózek
    • Aneta Lewkowicz
    • Adam M. Wojciechowski
    • Robert Bogdanowicz
    2024 DIAMOND AND RELATED MATERIALS

    Diamond particles (DPs) show promise for advanced applications in bioimaging and quantum sensing due to the presence of defect centers. This work reports a unique growth process for diamond particles composed of nitrogen-vacancy centers (NV-DPs) using a methyl trityl amine (C20H19N) diamondoid seed, which acts as a nitrogen source for NV creation. Growth was performed via microwave plasma-assisted chemical vapor deposition in a CH4/H2 plasma. Tantalum plates were chosen as the substrate to facilitate the release of the NV-rich DPs after growth. Raman spectra of NV-DPs grown at 550 °C showed a sharp, intense peak at ~1334 cm−1, while those grown at 750 °C exhibited a broader, high intensity peak at 1336 cm−1. Photoluminescence revealed the formation of high-density NV centers, with the highest intensity for NV-DPs grown at 750 °C and 20 Torr. Optically detected magnetic resonance confirmed the presence of NV centers, especially for DPs grown at 750 °C. This seeding process enables precise nitrogen incorporation into diamond crystals to generate required spin properties by growing high-quality, well-faceted NV-DPs with customizable NV densities.

  • Fabrication of the cross-linked PVA/TiO2/C nanocomposite membrane for alkaline direct methanol fuel cells
    • Faiz Khalid
    • Aashis S. Roy
    • Ameena Parveen
    • Roberto Castro Munoz
    2024 MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY (Materials Science and Engineering B-Advanced Functional Solid-State Materials)

    A crosslinked Poly(vinyl alcohol) based composite membrane was developed through a phase inversion process for use in alkaline direct methanol fuel cells (ADMFCs). The titanium dioxide (TiO2) and carbon nanoparticles (NPs) have been incorporated into the PVA polymer matrix to improve the mechanical and thermal properties. The membrane samples were further modified with maleic acid, a carboxylic acid acting as the cross-linker, under controlled temperature and time conditions to enhance electrochemical properties. The mechanical strength and thermal stability of membranes were determined using a Universal testing machine (UTM) and thermogravimetric analysis (TGA), while the crystallographic and morphological features were examined through X-ray diffraction (XRD) and Scanning electron microscopy (SEM), respectively. The proton conductivity (σ), methanol permeability, and water uptake (%) were also assessed. The XRD curves, SEM images, and TGA trends confirmed the successful cross-linking of maleic acid, uniform dispersion of nanoparticles (NPs), and excellent thermal stability in the crosslinked PVA-TiO2-C membrane. This sample also exhibited the highest tensile strength (163 MPa), and lower permeability (45000 Ss/cm3). Moreover, the ionic conductivity was obtained in the order of 10−2 S/cm. These combined characteristics position the cross-linked PVA-TiO2-C membrane as a promising candidate for application in alkaline direct methanol fuel cells (ADMFCs).

  • Facile synthesis and characterization of graphene and N-doped graphene by CVD method from liquid precursors for promising electrode materials
    • Mohammad Taghi Tourchi Moghadam
    • Karolina Cysewska
    2024 MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY (Materials Science and Engineering B-Advanced Functional Solid-State Materials)

    In this study, high-quality and few-layered graphene was synthesized using the chemical vapor deposition (CVD) method from liquid sources. Two different liquid carbon sources, pyridine, and benzene, were used and deposited on nickel foam under heat conditions using a bubbler in a quartz tube. X-ray diffraction (XRD) and Raman analysis confirmed the crystalline properties of graphene and N-doped graphene, demonstrating the high quality and few layers of graphene produced through the synthesis procedure. Energy dispersive X-ray (EDX) confirmed N doping while scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) provided clear sample morphology. The study reports the feasibility of utilizing liquid precursors to produce large-area, continuous, and mostly few-layer graphene, and N-doped graphene, making it a promising candidate for use as an electrode for different applications.

  • Facilitated water transport in composite reduced graphene oxide pervaporation membranes for ethanol upgrading
    • Maksymilian Plata Gryl
    • Grzegorz Boczkaj
    • Alfonso Policicchio
    • Alberto Figoli
    • Francesco Galiano
    • Roberto Castro Munoz
    2024 SEPARATION AND PURIFICATION TECHNOLOGY

    High purity ethanol is one of the most sought-after renewable energy sources. However, standard production methods yield ethanol of insufficient quality. Membrane processes such as pervaporation are recognized as a viable method for upgrading ethanol. Their performance and selectivity depend solely on membrane employed. Hydrophilic polyvinyl alcohol (PVA) membranes are used industrially for this purpose, but there is a trade-off between selectivity and permeability. Among other materials, chemically converted graphene attracts particular attention due to its exceptional water transport properties, however its application is limited by the fabrication of free-standing membranes. In this study, a composite reduced PVA/graphene oxide (rGO) membranes with different rGO content (up to 49 wt%) was synthesized. Polyvinyl alcohol acted as a mediator to improve the mechanical stability of membrane layers by crosslinking rGO flakes with hydrogen bonds. The resulting membranes were fully characterized by scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, water contact angle and mechanical tests. Pervaporation tests with water/ethanol mixtures (10/90 wt%) at temperatures between 20 and 50 °C demonstrated an excellent selectivity (over 12 000) of membranes and satisfactory flux, even at high temperatures. The total permeate flux for membranes varied slightly as a function of operating temperature, demonstrating a good thermostability of the reduced graphene oxide-based membranes. The pervaporation separation index (PSI) of synthesized membrane exceed 5000 and surpassed majority of rGO containing membranes reported in the literature. Results indicate that rGO membranes noncovalently strengthened with PVA are a promising material for selective ethanol dehydration via pervaporation.

  • Fast EM-Driven Nature-Inspired Optimization of Antenna Input Characteristics Using Response Features and Variable-Resolution Simulation Models
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    2024 Full text Scientific Reports

    Utilization of optimization technique is a must in the design of contemporary antenna systems. Often, global search methods are necessary, which are associated with high computational costs when conducted at the level of full-wave electromagnetic (EM) models. In this study, we introduce an innovative method for globally optimizing reflection responses of multi-band antennas. Our approach uses surrogates constructed based on response features, smoothing the objective function landscape processed by the algorithm. We begin with initial parameter space screening and surrogate model construction using coarse-discretization EM analysis. Subsequently, the surrogate evolves iteratively into a co-kriging model, refining itself using accumulated high-fidelity EM simulation results, with the infill criterion focusing on minimizing the predicted objective function. Employing a particle swarm optimizer (PSO) as the underlying search routine, extensive verification case studies showcase the efficiency and superiority of our procedure over benchmarks. The average optimization cost translates to just around ninety high-fidelity EM antenna analyses, showcasing excellent solution repeatability. Leveraging variable-resolution simulations achieves up to a seventy percent speedup compared to the single-fidelity algorithm.

  • Fast Re-Design of Multi-Band Antennas by Means of Orthogonal-Direction Geometry Scaling and Local Parameter Tuning
    • Anna Pietrenko-Dąbrowska
    • Sławomir Kozieł
    2024 IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION

    Application-driven design of antenna systems fosters a reuse of structures that have proven competitive in terms of their electrical and field performance, yet have to be re-designed for a new application area. In practice, it most often entails relocation of the operating frequencies or bandwidths, which is an intricate endeavor, normally requiring utilization of numerical optimization techniques. If the center frequencies of the available design reside away from the targets, local routines tend to be inadequate, whereas global procedures incur extraordinary computational costs, which may be unmanageable if antenna characteristics are evaluated using full-wave electromagnetic (EM) analysis. Recently, a procedure involving a combination of joint parameter scaling and intermittent local tuning has been proposed and shown effective in re-design of single-band microwave devices across broad ranges of operational frequencies. Here, we introduce a generalized framework that capitalizes on the aforementioned concept but enables independent scaling of multiple operating frequencies. The fundamental component of the developed approach is identification of orthogonal scaling directions affecting individual center frequencies, which is a non-trivial extension of concurrent parameter adjustment. Our technique has been validated using several multi-band antennas, all re-designed for operating conditions unreachable using conventional tuning methods. Superior performance has been demonstrated for all considered cases in terms of a precise allocation of antenna resonances while maintaining low computational cost, lower than 180 EM antenna analyses on the average. Experimental validation has been also provided.

  • Fatigue behaviour of SLM maraging steel under variable-amplitude loading
    • Zbigniew Marciniak
    • Ricardo Branco
    • Wojciech Macek
    • Cândida Malça
    2024 Full text Procedia Structural Integrity

    One of the most challenging issues for additive manufactured materials is fatigue endurance. Engineering components often operate under complex, variable amplitude loadings, in which existing technological imperfections promote fatigue cracks growth and damage of elements eventually. In this study the effects of different variable-amplitude strain levels on fatigue life, 18Ni300 steel was tested. The work presents various behaviours of the material depending on the load level.

  • Fault detection in the marine engine using a support vector data description method
    • Klaudia Wrzask
    • Jerzy Kowalski
    • Van Vang Le
    • Van Bac Nguyen
    • Dao Nam Cao
    2024 Journal of Marine Engineering and Technology

    Fast detection and correct diagnosis of any engine condition changes are essential elements of safety andenvironmental protection. Many diagnostic algorithms significantly improve the detection of malfunctions.Studies on diagnostic methods are rarely reported and even less implemented in the marine engine industry.To fill this gap, this paper presents the Support Vector Data Description (SVDD) method as applied to thefault detection of the fuel delivery system of a two-stroke marine engine. The selected diagnostic data is theexhaust gas composition, with four components considered: oxygen, carbon oxide, nitric oxide, and carbondioxide. With these diagnostics, the method distinguishes eight different engine faults from the efficient state.The manuscript presents in detail the methodology for applying the SVDD method in a marine engine. Themethod of obtaining diagnostic data and its scaling is described. The method of training and validating thealgorithm is also presented, along with ready-made algorithms for use. The 100% accuracy of the proposedfault detection method. Based on the obtained results, the proposed fault detection method is promising fora simple application. Moreover, generalised algorithms that may be adapted to different technical solutionsare also presented.

  • Feasibility Study of Three-Phase Modular Converter for Dual-Purpose Application in DC and AC Microgrids
    • Carlos Roncero-Clemente
    • Oleksandr Husev
    • Oleksandr Matiushkin
    • Javier Gutiérrez-Escalona
    • Fermin Barrero-Gonzalez
    • Dmitri Vinnikov
    • Ryszard Strzelecki
    2024 IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS

    The modern concept of a universal converter is intended as a power converter (PC) suitable for application in both dc or ac grids using the same external connectors. This novel family was recently proposed to allow easier integration of renewable energy sources and energy storage systems (ESSs), interfacing with dc/ac grids and/or loads with a minimum redundancy of power switches and passive elements. This kind of solution and applications are expected to be a reality in the nearest decade, as ac and dc low voltage distribution networks will coexist. Nevertheless, the initial solutions proposed as universal converters were focused on ac single-phase power conversion systems. In this sense, this article proposes and describes a new member of the universal converter family suitable for dc–dc and dc–ac power conversion (both in three-phase three-wire and in three-phase four-wire). The proposed power topology is derived as a modular extension from the single buck-boost bidirectional cell. Its main operation modes (buck and boost) are discussed, and a pulsewidth-modulation technique is developed to generate the corresponding switching patterns. The proposed solution is successfully validated in open-loop mode both in simulation and experimentally with a laboratory prototype. The measured efficiency of the PC was above 97% in the dc–ac mode and around 99% in the dc–dc mode.

  • Feasibility Study of Three-Phase Modular Converter for Dual-Purpose Application in DC and AC Microgrids
    • Carlos Roncero-Clemente
    • Oleksandr Husev
    • Oleksandr Matiushkin
    • J. Gutierrez-Escalona
    • Fermin Barrero-Gonzalez
    • D. Vinnikov
    • Ryszard Strzelecki
    2024 IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS

    The modern concept of a universal converter is intended as a power converter suitable for application in both dc or ac grids using the same external connectors. This novel family was recently proposed to allow an easier integration of renewable energy sources and energy storage systems, interfacing with dc/ac grids and/or loads with a minimum redundancy of power switches and passive elements. This kind of solution and applications are expected to be a reality in the nearest decade, as ac and dc low voltage distribution networks will coexist. Nevertheless, the initial solutions proposed as universal converter were focused on ac single-phase power conversion systems. In this sense, this article proposes and describes a new member of the universal converter family suitable for dc to dc and dc to ac power conversion (both in three-phase three-wire and in three-phase four-wire). The proposed power topology is derived as a modular extension from the single buck-boost bidirectional cell. Its main operation modes (buck and boost) are discussed, and a pulse-width-modulation technique is developed to generate the corresponding switching patterns. The proposed solution is successfully validated in open-loop mode both in simulation and experimentally with a laboratory prototype. The measured efficiency of the power converter was above 97% in the dc to ac mode and around 99% in the dc to dc mode

  • Feedback Control of Doubly-Fed Generator Connected to Current Source Converter
    • Marcin Morawiec
    • Pawel Kroplewski
    • Filip Wilczyński
    2024 IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS

    Doubly-fed induction generator (DFIG) system supplied by current source converter (CSC) is considered in this article. The DFIG can work in two independent modes: AC grid connection and stand-alone mode. The DFIG is connected to the ac grid directly through its stator and the CSC links the rotor side. In this mode, the active and reactive powers of the DFIG must be controlled. This article proposes two control system structures for the DFIG working in the generator mode. Both control structures are based on nonlinear transformations but on different state-feedback control variables. The selection of the variables is similar to the input–output linearization but more complicated due to the CSC and “voltage control” involved. Both proposed control structures ensure independent control of the active and reactive powers with different accuracies; as evidenced in the simulation and experimental results. The proposed approach can be named by voltage control of the DFIG because the control variables are the voltage in the dc-link and the angular speed of the output current vector from the inverter. For both proposed control structures, the current in the dc-link is not a constant value, but depends on the dynamic states and values of the controlled powers; thus, it varies accordingly. The proposed control strategy can be applied to low- and high-power DFIG systems. Simulation and experimental results from a 2-kW generator validate theoretical propositions.

  • FEM simulations applied to the failure analysis of RC structure under the influence of municipal sewage pressure
    • Łukasz Skarżyński
    • Ireneusz Marzec
    2024 ENGINEERING FAILURE ANALYSIS

    The paper discusses a failure mechanism of reinforced concrete (RC) structure with steel cover that failed under the influence of municipal sewage pressure. To explain the reasons of failure, in-situ measurements, laboratory experiments and comprehensive Finite Element Method (FEM) computations were performed. Non-destructive in-situ scanning tests were carried out to determine quantity and cover thickness of embedded reinforcement bars, simultaneously, laboratory tests regarding concrete and shotcrete thickness, density and compressive strength were performed on samples prepared from core drills taken from the RC structure. FEM computations were carried out with the constitutive continuum model for concrete and steel with material parameters designated on the basis of stress-strain curves in uniaxial compression and uniaxial tension, respectively. An isotropic coupled elasto-plastic-damage formulation based on the strain equivalence hypothesis was used. In order to describe strain localization in concrete, model was enhanced in a softening regime by a characteristic length of micro-structure by means of a non-local theory. FEM analyses were carried out for different values of sewage pressure. The main attention was paid to the evolution of steel cover deformation and strain localization of the RC ceiling slab. FEM results revealed strong dependence between a bond-slip between anchors and steel cover deformation as well as between sewage pressure value and strain localization pattern of RC structure. Mechanism of the structure failure under complex loading conditions was realistically captured and its reasons were discussed in detail.

  • Femtosecond laser ablated trench array for improving performance of commercial solid oxide cell
    • Mohamed A. Baba
    • Bartłomiej Lemieszek
    • Mantas Sriubas
    • Brigita Abakevičiene
    • Sigitas Tamulevičius
    • Sebastian Molin
    • Tomas Tamulevičius
    2024 JOURNAL OF POWER SOURCES

    The performance of electrode-supported solid oxide cells (SOCs) is limited adversely by gas diffusion impedance in thick and porous support. This work focuses on the improvement of gas transport properties of commercial Ni-YSZ anode-supported SOFC by femtosecond laser-based micromachining where micro-holes of identical depth but different hole separations pitches with minimal heated affected zones were imposed. The polarization resistance calculations and DRT analysis revealed that the presence of the micro-holes improves fuel transport in the anode active zone of commercial SOFC. The presence of the micro-holes resulted in up to 20.8 % and up to 17.2 % reduction in polarization resistance for dry H2 and wet H2 gas-fueled SOFC samples, respectively. Moreover, the decrease in intensity of peaks responsible for fuel diffusion with increasing micro-holed density was observed. Therefore, dense and sparse cells exhibited a performance augmentation of 25 % and 11 % in dry H2 and enhancement of 16 % and 15.6 % in wet H2, respectively. Fs-laser ablation appeared as a unique capability for the post-processing of SOFC elements via imposing different gas channel geometries.

  • Few-Layer Black Phosphorus/Chitosan Nanocomposite Electrodes via Controlled Electrodeposition for Enhanced Electrochemical Kinetic Performance
    • Paweł Jakóbczyk
    • Iwona Kaczmarzyk
    • Robert Bogdanowicz
    2024 Journal of Physical Chemistry C

    This study presents the preparation and characterization of few-layer black phosphorus (FLBP) chitosan electrodes by controlled electrochemical deposition of chitosan nanoparticles on FLBP-modified glassy carbon electrodes. FLBP was prepared by solvent-assisted exfoliation of bulk BP and was further modified with chitosan forming together a nanocomposite, including easy cross-linking with nanomaterials and film-forming properties. Cyclic voltammetry was employed to analyze the kinetic properties of electrodes fabricated at different electrochemical deposition durations of chitosan, revealing distinct reduction and oxidation peaks using 10 V. The electrochemical impedance spectroscopy technique was employed to further characterize the investigated FLBP-chitosan nanocomposites, which provides valuable insights into the electrode material properties. The controlled electrochemical deposition of chitosan nanoparticles on FLBP-modified glassy carbon electrodes opens up possibilities for developing a wide range of electrochemical sensors and devices for energy storage applications.

  • Field Calibration of Low-Cost Particulate Matter Sensors Using Artificial Neural Networks and Affine Response Correction
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    • Marek Wójcikowski
    • Bogdan Pankiewicz
    2024 Full text MEASUREMENT

    Due to detrimental effects of atmospheric particulate matter (PM), its accurate monitoring is of paramount importance, especially in densely populated urban areas. However, precise measurement of PM levels requires expensive and sophisticated equipment. Although low-cost alternatives are gaining popularity, their reliability is questionable, attributed to sensitivity to environmental conditions, inherent instability, and manufacturing imperfections. The objectives of this paper include (i) introduction of an innovative approach to field calibration for low-cost PM sensors using artificial intelligence methods, (ii) implementation of the calibration procedure involving optimized artificial neural network (ANN) and combined multiplicative and additive correction of the low-cost sensor readings, (iii) demonstrating the efficacy of the presented technique using a custom-designed portable PM monitoring platform and reference data acquired from public measurement stations. The results obtained through comprehensive experiments conducted using the aforementioned low-cost sensor and reference data demonstrate remarkable accuracy for the calibrated sensor, with correlation coefficients of 0.86 for PM1 and PM2.5, and 0.76 PM10 (particles categorized as having diameter equal to or less than 1m, 2.5m, and 10m, respectively), along with low RMSE values of only 3.1, 4.1, and 4.9 µg/m³.

  • Fine-Tuning the Photocatalytic Activity of the Anatase {1 0 1} Facet through Dopant-Controlled Reduction of the Spontaneously Present Donor State Density
    • Szymon Dudziak
    • Jakub Karczewski
    • Adam Ostrowski
    • Grzegorz Trykowski
    • Kostiantyn Nikiforow
    • Anna Zielińska-Jurek
    2024 Full text ACS Materials Au

    The present study highlights the importance of the net density of charge carriers at the ground state on photocatalytic activity of the faceted particles, which can be seen as a highly underexplored problem. To investigate it in detail, we have systematically doped {1 0 1} enclosed anatase nanoparticles with Gd3+ ions to manipulate the charge carrier concentration. Furthermore, control experiments using an analogical Nb5+ doped sample were performed to discuss photocatalytic activity in the increased range of free electrons. Overall results showed significant enhancement of phenol degradation rate and coumarin hydroxylation, together with an increase of the designed Gd/Ti ratio up to 0.5 at. %. Simultaneously, the mineralization efficiency, measured as a TOC reduction, was controlled between the samples. The observed activity enhancement is connected with the controlled decrease of the donor state density within the materials, being the net effect of the spontaneously present defects and introduced dopants, witch reduce hydroxylation and the hole trapping ability of the {1 0 1} facets. This allows to fine-tune multi-/single-electron processes occurring over the prepared samples, leading to clear activity maxima for 4-nitrophenol reduction, H2O2 generation, and ·OH formation observed for different donor densities. The optimized material exceeds the activity of the TiO2 P25 for phenol degradation by 52% (377% after surface normalization), showing its suitable design for water treatment. These results present a promising approach to boost photocatalyst activity as the combined result of the exposed crystal facet and dopant-optimized density of ground-state charge carriers.

  • Finger Vein Presentation Attack Detection Method Using a Hybridized Gray-Level Co-Occurrence Matrix Feature with Light-Gradient Boosting Machine Model
    • Kashif Shaheed
    • Piotr Szczuko
    • Inam Ullah
    • Hammed Mojeed
    • Abdullateef O. Balogun
    • Luiz Fernando Capretz
    2024

    Presentation Attack Detection (PAD) is crucial in biometric finger vein recognition. The susceptibility of these systems to forged finger vein images is a significant challenge. Existing approaches to mitigate presentation attacks have computational complexity limitations and limited data availability. This study proposed a novel method for identifying presentation attacks in finger vein biometric systems. We have used optimal Gray-Level Co-occurrence Matrix (GLCM) features with the Light-Gradient Boosting Machine (LGBM) classification model. We use statistical texture attributes namely, energy, correlation, and contrast to extract optimal features from counterfeit and authentic finger-vein images. The study investigates cluster-pixel connectivity in finger vein images. Our approach is tested using K-fold cross-validation and compared to existing methods. Results demonstrate that Light-GBM outperforms other classifiers. The proposed classifier achieved low APCER values of 2.73% and 8.80% compared to other classifiers. The use of Light-GBM in addressing presentation attacks in finger vein biometric systems is highly significant.

  • Fire evacuations of public places - theory and practise
    • Beata Świeczko-Żurek
    • Marcin Żurek
    2024

    Publikacja dotyczy ewakuacji pożarowych miejsc publicznych.

  • Fire-Retardant Flexible Foamed Polyurethane (PU)-Based Composites: Armed and Charmed Ground Tire Rubber (GTR) Particles
    • Paulina Kosmela
    • Kamila Sałasińska
    • Daria Kowalkowska-Zedler
    • Mateusz Barczewski
    • Adam Piasecki
    • Mohammad Saeb
    • Aleksander Hejna
    2024 Full text Polymers

    Inadequate fire resistance of polymers raises questions about their advanced applications. Flexible polyurethane (PU) foams have myriad applications but inherently suffer from very high flammability. Because of the dependency of the ultimate properties (mechanical and damping performance) of PU foams on their cellular structure, reinforcement of PU with additives brings about further concerns. Though they are highly flammable and known for their environmental consequences, rubber wastes are desired from a circularity standpoint, which can also improve the mechanical properties of PU foams. In this work, melamine cyanurate (MC), melamine polyphosphate (MPP), and ammonium polyphosphate (APP) are used as well-known flame retardants (FRs) to develop highly fire-retardant ground tire rubber (GTR) particles for flexible PU foams. Analysis of the burning behavior of the resulting PU/GTR composites revealed that the armed GTR particles endowed PU with reduced flammability expressed by over 30% increase in limiting oxygen index, 50% drop in peak heat release rate, as well as reduced smoke generation. The Flame Retardancy Index (FRI) was used to classify and label PU/GTR composites such that the amount of GTR was found to be more important than that of FR type. The wide range of FRI (0.94–7.56), taking Poor to Good performance labels, was indicative of the sensitivity of flame retardancy to the hybridization of FR with GTR components, a feature of practicality. The results are promising for fire protection requirements in buildings; however, the flammability reduction was achieved at the expense of mechanical and thermal insulation performance.

  • First highly effective non-catalytic nitrobenzene reduction in UV/dithionite system with aniline production – Advanced reduction process (ARP) approach
    • Łukasz Cichocki
    • Lingshuai Kong
    • Chongqing Wang
    • Andrzej Przyjazny
    • Grzegorz Boczkaj
    2024 Full text CHEMICAL ENGINEERING JOURNAL

    Advanced reduction processes (ARPs) are currently intensively investigated as an alternative to Advanced Oxidation Processes (AOPs). The study presents efficient reduction of nitrobenzene under non-catalytic conditions through reaction with free radicals having reductive potential. Effective conversion of nitrobenzene in a model wastewater solution, was obtained for sodium dithionite (SDT)/ dithionite (DTN). The developed process provide a nitrobenzene reduction efficiency of > 99.9 % within 10 min under neutral conditions, ambient temperature, with a molar ratio of reductant to pollutant (rred) of 3. Additional UV radiation lowered by 10 % the dose of DTN. Interestingly, addition of titanium dioxide (TiO2) as a photocatalyst did not show a positive effect. An extremely significant conclusion of this study is the observed excellent resistance of the reaction system to the negative influence of inorganic anions, with a reduction in efficiency in the following order: and dissolved organic matter (DOM) . The study showed that the process works effectively across the pH range from 3 to 12. Studies on the reaction mechanism revealed that sulfur dioxide anion radical ) was responsible for the main reduction effect. The main product of nitrobenzene reduction was aniline (>99.9 %). The total cost of purification process was USD 0.77/m3. The high efficiency, short process time, low cost, and lack of need for complicated equipment make this developed process potentially widely applicable in the industry. The developed method for the reduction of nitrobenzene to aniline is the first non-catalytic method with such high efficiency and without the formation of intermediate reaction products.

  • Flap Monitoring Techniques: A Review
    • Ignacy Rogoń
    • Agnieszka Rogoń
    • Adam Kaczmarek
    • Adam Bujnowski
    • Jerzy Wtorek
    • Filip Lachowski
    • Jerzy Jankau
    2024 Journal of Clinical Medicine

    Postoperative tissue flap vitality monitoring enables early detection of clinical complications, allowing for intervention. Timely re-operation can prevent the need for extensive correction procedures, thus reducing healthcare costs and hospitalisation time. Statistics show that monitoring can increase the success rate of flap survival to 95\% or higher. However, despite the significant progress in monitoring techniques, major and minor complications, leading to the loss of the flap, still occur. This clinical application review aims to provide a comprehensive overview of the recent advancements and findings in flap surgery reconstructions, transplants, and systems for their postoperative assessment. Literature from the years 1925 to 2024 has been reviewed to capture previous and current solutions for monitoring flap vitality. Clinically acclaimed methods and experimental techniques were classified and reviewed from a technical and clinical standpoint. Physical examination, metabolism change, ultrasound method, and electromagnetic (EM) radiation-based measurement methods were carefully evaluated from the perspective of their considered applications. Guidelines aiding engineers in the future design and development process of monitoring systems were proposed. This paper provides a comprehensive overview of the monitoring techniques used in postoperative flap vitality monitoring. It also gives an overview of each approach and potential ways for future development.

  • Flicker Noise in Resistive Gas Sensors—Measurement Setups and Applications for Enhanced Gas Sensing
    • Janusz Smulko
    • Graziella Scandurra
    • Katarzyna Drozdowska
    • Andrzej Kwiatkowski
    • Carmine Ciofi
    • He Wen
    2024 Full text SENSORS

    We discuss the implementation challenges of gas sensing systems based on low-frequency noise measurements on chemoresistive sensors. Resistance fluctuations in various gas sensing materials, in a frequency range typically up to a few kHz, can enhance gas sensing by considering its intensity and the slope of power spectral density. The issues of low-frequency noise measurements in resistive gas sensors, specifically in two-dimensional materials exhibiting gas-sensing properties, are considered. We present measurement setups and noise-processing methods for gas detection. The chemoresistive sensors show various DC resistances requiring different flicker noise measurement approaches. Separate noise measurement setups are used for resistances up to a few hundred kΩ and for resistances with much higher values. Noise measurements in highly resistive materials (e.g., MoS2, WS2, and ZrS3) are prone to external interferences but can be modulated using temperature or light irradiation for enhanced sensing. Therefore, such materials are of considerable interest for gas sensing.

  • Floodsar: Automatic mapping of river flooding extent from multitemporal SAR imagery
    • Tomasz Berezowski
    • Szymon Niemiec
    • Andrzej Chybicki
    2024 Full text SoftwareX

    Floodsar is an open-source tool for automatic mapping of the flood extent from a time series of synthetic aperture radar (SAR) imagery. Floodsar is unsupervised, however, it requires defining the parameters search space, geographical area of interest, and some river gauge observations (e.g. water levels or discharges) time series that overlap temporarily with the SAR imagery. Applications of Floodsar are mainly in real-time monitoring and elaborating long-time series of historical data. Floodsar features two algorithms for flood extent mapping. The 1D algorithm identifies a flood/no-flood threshold in one SAR polarization. The 2D algorithm performs clustering on two SAR polarizations at the same time. Floodsar chooses the optimal threshold or the composition of clusters by maximizing the correlation between the resulting flood area and the river gauge observations. Floodsar was tested on three case studies with different land uses to illustrate its performance. The 2D algorithm performed on average the best with the average kappa=0.78, yet the less complex 1D/VV algorithm obtained similar results.

  • Fluctuation-Enhanced Sensing of Organic Vapors by Ink-Printed MoS2 Devices under UV Irradiation
    • Katarzyna Drozdowska
    • Janusz Smulko
    • Sergey Rumyantsev
    • Andrzej Kwiatkowski
    2024

    This work presents the results of fluctuationenhanced sensing (FES) of selected organic gases by MoS2 sensor fabricated via a simple ink printing method. We demonstrate that low-frequency noise measured under UV irradiation (275 nm) is more sensitive to different gases than measured in the dark. The noise at 1 Hz under UV light increased 3.3, 3.5, 1.6, and 2.9 times for chloroform, tetrahydrofuran, acetonitrile, and acetone ambiances, respectively. By comparing the noise spectra collected in the dark and under UV light, we report that irradiation has a visible effect on the noise in the lowest frequency range (0.125–10 Hz), changing mainly the slope of the spectra. Thus, each organic gas produces a distinct signature by affecting the noise amplitude and the shape of the spectrum. The differences in the characteristic noise features among organic vapors are ascribed to differences in their molecular configuration and polar properties.

  • Fluorescence of p-hydroxyazobenzocrowns – Tautomeric equilibrium effect
    • Paulina Szulc
    • Elżbieta Luboch
    • Andrzej Okuniewski
    • Ewa Wagner-Wysiecka
    2024 SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY

    The spectroscopic properties of a series of para-hydroxyazobenzocrowns, including three novel compounds, were investigated using UV–Vis absorption and emission spectroscopy. This study presents, for the first time, determined quantum yield (QY) values for macrocycles of this category, ranging between 0.122 and 0.195. The highest values were obtained for crowns bearing two phenyl substituents in benzene rings. The impact of aromatic ring substituents and macroring size on the spectral characterization (1H NMR and FTIR) of p-hydroxyazobenzocrowns was examined in consideration of the azophenol ⇄ quinone-hydrazone tautomeric equilibrium. Dipole moments of p-hydroxyazobenzocrowns in the ground and excited states have been determined. The alignment between experimental findings and theoretical studies was established.

  • Fluvial ecology disasters: the impact of the Gliwice Canal on the ecological crisis in the Oder River basin, Poland (2022)
    • Marek Ruman
    • Natalia Janczewska
    • Klaudia Kosek
    • Wojciech Artichowicz
    • Magdalena Nasiek
    • Magdalena Matysik
    2024 Acta Geophysica

    In August 2022, the Oder River experienced an ecological disaster, resulting in the extinction of hundreds of aquatic organ- isms. Mass fsh deaths also occurred during that time in the Gliwice Canal, located in southern Poland, which connects to the upper section of the Oder River. The aim of the article was to assess the impact of the waters from the Gliwice Canal on the water quality changes in the Oder River, as expressed by chloride, sulphate, nitrate, phosphate content, as well as its parameters such as conductivity, temperature, and pH. Statistical analyses were conducted based on our own research and a series of data collected by the Chief Inspectorate for Environmental Protection. Below the confuence of the Oder River with the waters of the canal, an increase in sulphates levels and a decrease in sodium content were observed. The other parameters remained unchanged. It was also noted that the magnitude of each parameter was signifcantly higher in the waters of the Gliwice Canal compared to the Oder River. The research conclusion is that there is no infuence of the canals’ waters on the quality of the Oder River waters, both during the ecological disaster and afterwards. The presented research clearly indicates the need for separate analyses of fowing waters (with signifcantly higher salt and other pollutant dissolution capacity) and stagnant waters in water infrastructure (without water exchange).

  • Forecasting energy consumption and carbon dioxide emission of Vietnam by prognostic models based on explainable machine learning and time series
    • Thanh Tuan Le
    • Prabhakar Sharma
    • Sameh M. Osman
    • Marek Dzida
    • Phuoc Quy Phong Nguyen
    • Minh Ho Tran
    • Dao Nam Cao
    • Viet Dung Tran
    2024 Clean Technologies and Environmental Policy

    This study assessed the usefulness of algorithms in estimating energy consumption and carbon dioxide emissions in Viet- nam, in which the training dataset was used to train the models linear regression, random forest, XGBoost, and AdaBoost, allowing them to comprehend the patterns and relationships between population, GDP, and carbon dioxide emissions, energy consumption. The results revealed that random forest, XGBoost, and AdaBoost outperformed linear regression. Furthermore, for random forest, XGBoost, and AdaBoost, the coefficients of determination were higher, indicating a better fit to the data. Moreover, time series forecasting models such as autoregressive integrated moving average, seasonal autore- gressive integrated moving average, and exponential smoothing were used to predict future energy consumption and carbon dioxide emissions in Vietnam. The models were trained and verified using historical data. The time series model findings showed that energy consumption rose steadily during the predicted timeframe. The autoregressive integrated moving aver- age model predicted 162258.77 ktoe of energy use by 2050, whereas the seasonal autoregressive integrated moving average and exponential smoothing modes predicted 160673.8 ktoe and 153206.44 ktoe of energy use, respectively. By 2050, the autoregressive integrated moving average model anticipated 6.51 metric tons of carbon dioxide emissions per capita, the SARIMA model 7.769 metric tons, and the exponential smoothing model 6.22 metric tons. The findings show how machine learning techniques and time series models may be used to estimate energy usage and carbon dioxide emissions in Vietnam. These insights could assist Vietnam government in making informed judgments concerning energy planning and policy development

  • Fractional Spectral and Fractional Finite Element Methods: A Comprehensive Review and Future Prospects
    • Muhammad Bilal Hafeez
    • Marek Krawczuk
    2024 ARCHIVES OF COMPUTATIONAL METHODS IN ENGINEERING

    In this article, we will discuss the applications of the Spectral element method (SEM) and Finite element Method (FEM) for fractional calculusThe so-called fractional Spectral element method (f-SEM) and fractional Finite element method (f-FEM) are crucial in various branches of science and play a significant role. In this review, we discuss the advantages and adaptability of FEM and SEM, which provide the simulations of fractional derivatives and integrals and are, therefore, appropriate for a broad range of applications in engineering, biology, and physics. We emphasize that they can be used to simulate a wide range of real-world phenomena because they can handle fractional differential equations that are both linear and nonlinear. Although many researchers have already discussed applications of FEM in a variety of fractional differential equations (FDEs) and delivered very significant results, in this review article, we aspire to enclose fundamental to advanced articles in this field which will guide the researchers through recent achievements and advancements for the further studies.

  • Fracture prediction in flat PMMA notched specimens under tension - effectiveness of the equivalent material concept and fictitious material concept
    • Elżbieta Bura
    • A.r. Torabi
    • Andrzej Seweryn
    2024 Full text THEORETICAL AND APPLIED FRACTURE MECHANICS

    The fracture of notched elements under mode I loading (tension) remains an inexhaustible research topic, especially when it comes to the fracture of thermoplastic materials such as polymethylmethacrylate (PMMA), which experience considerable plastic strains under tension. The paper points out that traditional brittle fracture criteria such as mean stress (MS) or maximum tangential stress (MTS) criteria used to predict this phenomenon do not accurately indicate the value of the critical load. They work much better when combined with the equivalent material concept (EMC) and fictitious material concept (FMC). The effectiveness of both concepts depends on the size of the notch root radius, and thus on the yield zone size.

  • Fracture surface topography measurements analysis of low-alloyed corrosion resistant steel after bending-torsion fatigue tests
    • Przemysław Podulka
    • Wojciech Macek
    • Beata Zima
    • Mateusz Kopec
    • Ricardo Branco
    • Henryk Achtelik
    2024 PRECISION ENGINEERING-JOURNAL OF THE INTERNATIONAL SOCIETIES FOR PRECISIONENGINEERING AND NANOTECHNOLOGY

    In this paper, an assessment of a topography measurement method for fracture surfaces of 10HNAP steel after bending-torsion fatigue tests was performed. Surface roughness was measured by using a non-contact Focus Variation Microscopy (FVM) technique in which the non-measured points (NMPs) and outliers (spikes) were removed by the application of general methods. The results revealed, that the optical measurement method introduced variations in the high-frequency errors, considered as noise within the selected bandwidth. Therefore, the minimization of the high-frequency noise (HFN) was proposed based on an extensive examination of ISO 25178 roughness parameters. Additionally, a general S-filter was applied, as recommended by international standards and commercial software. It was used to identify and remove noise from the measured data after pre-processing. Consequently, levelling and eliminating of NMPs and spikes was successfully performed. Subsequently, the results obtained by using various filters were compared to further assess the impact of different filtration bandwidths. Finally, the proposed procedure was validated by implementing different general functions, such as autocorrelation (ACF), power spectral densities (PSD), and texture direction (TD). It was concluded, that coupled characteristics, including profile and areal measurements, should be studied simultaneously since they are necessary to analyze the fracture surfaces comprehensively.

  • Fracture susceptibility of high RAP content asphalt concrete in terms of aging
    • Cezary Szydłowski
    2024

    Due to the reduction of CO2 emissions during the production of asphalt mixtures and the decrease in the demand for mineral resources, the addition of reclaimed asphalt pavement (RAP) is becoming indispensable. The durability of asphalt pavements containing a high RAP content may be reduced due to a decrease in the cracking resistance of the material, especially under the influence of operational aging. The article presents the results of tests and analysis of fracture susceptibility of asphalt concretes with the addition of RAP (binder replacement ratio BR = 0.2 and 0.4), considering long-term aging. Asphalt mixtures were evaluated based on the semi-circular bending (SCB) test at intermediate temperature. It can be concluded that the addition of RAP with BR = 0.2 causes a decrease in fracture resistance comparable to that of the mixture without RAP but after long-term aging. The addition of RAP reduces the Flexibility Index (FI) by approximately 40% for short-term aging and 30% for long-term aging.

  • Framework for extracting rails and setting-out railway line axis based on UAV photogrammetric measurements
    • Paweł Burdziakowski
    • Cezary Specht
    • Andrzej Stateczny
    • Mariusz Specht
    • Pawel S. Dabrowski
    • Oktawia Lewicka
    2024 Full text International Journal of Rail Transportation

    Technical diagnostics enables assessing the current technical condition of a railway line and adjacent infrastructure, and forecasting its changes over a specific time horizon. One of its elements is the periodic monitoring of rail position and their geometry. This article presents a new framework for the setting-out of a railway track axis. The process presented in the manuscript is based on the specific filtration and extraction of rails from a point cloud originating from the photogrammetric process. Data was acquired using a small unmanned aerial vehicle (UAV). A railway track axis setting-out using the process described herein was related to dynamic satellite track measurement. An average accuracy achieved in the horizontal plane is 1.6 cm which corresponds to the accuracy of the source photogrammetric product. The achieved accuracy enables using this method to be suitable for technical track monitoring, geoinformation, and cartographic work.

  • Framework interfejsu radiowego NB-IoT
    • Olga Błaszkiewicz
    • Jarosław Magiera
    • Alicja Olejniczak
    • Piotr Rajchowski
    • Jarosław Sadowski
    • Jacek Stefański
    • Krzysztof Cwalina
    2024 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    W niniejszym artykule opisano rezultaty uzyskane w ramach zrealizowanego projektu definiowanego programowo frameworka wąskopasmowego interfejsu radiowego dla urządzeń Internetu Rzeczy. Przedstawiono elementy składowe konfigurowalnego interfejsu radiowego oraz jego charakterystykę eksploatacyjną.

  • Frequency-Reconfigurable Hybrid SIW-Based Self-Diplexing Antenna Using Solid and Liquid Dielectric Loading
    • Mettu Goutham Reddy
    • Karthikeyan Subramanian
    • Nrusingha Pradhan
    • Sławomir Kozieł
    2024 IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS

    This paper presents a novel frequencyreconfigurable self-diplexing antenna (SDA) utilizing a hybrid substrate-integrated waveguide (SIW). The antenna comprises a radiating slot, a feeding network, and a hybrid SIW cavity featuring half-mode circular and half-mode rectangular SIW structures. The unique feature of this antenna lies in its fine-tuning capability of each resonant frequency by inserting or injecting solid and liquid dielectrics into designated etched pockets. Experimental results demonstrate that the proposed structure can be effectively tuned within the frequency range of 2.7 to 3.47 GHz for the lower band and 4.05 to 4.96 GHz for the upper band. The mutual coupling between the ports is better than 20.4 dB, and the antenna maintains consistent radiation patterns across the entire operating range. The proposed tunable antenna, featuring precise frequency tuning capability, compact size, and stable radiation patterns, is well suited for various applications, including wireless communication systems, biomedical telemetry, microwave imaging, WiMAX, and Wi-Fi.

  • Frequency-Variant Double-Zero Single-Pole Reactive Coupling Networks for Coupled-Resonator Microwave Bandpass Filters
    • Muhammad Yameen Sandhu
    • Maciej Jasiński
    • Adam Lamęcki
    • Roberto Gómez-García
    • Michał Mrozowski
    2024 IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES

    In this work, a family of frequency-variant reactive coupling (FVRC) networks is introduced and discussed as new building blocks for the synthesis of coupled-resonator bandpass filters with real or complex transmission zeros (TZs). The FVRC is a type of nonideal frequency-dependent inverter that has nonzero elements on the diagonal of the impedance matrix, along with a nonlinear frequency-variation profile of its transimpedance parameter. The distinctive feature of these new FVRCs is that they can be modeled with a simple bridged-T network consisting of four reactive elements. Such FVRCs can introduce one pole and up to two TZs—so that they are referred to as double-zero single-pole (DZSP) networks. DZSP networks allow the pole to be located above, below, or inbetween the TZs. Depending on the choice of the elements in the bridged-T circuit, the position of the TZs and the pole can be controlled independently. The coupling matrix for filters with DZSP networks can be found by solving an inverse-structured nonlinear eigenvalue problem (ISNEVP). Examples of possible implementations of DZSP coupling networks are provided for both lumped and quasi-lumped-element circuits, as well as for transmission-line-based and waveguide technologies. The application of DZSP coupling networks to the design of microwave bandpass filters with generalized Chebyshev-type characteristics is illustrated by means of the synthesis of three microstrips and two waveguide coupled-resonator bandpass filters. The waveguide filters are verified through electromagnetic (EM) simulations and the microstrip filters are manufactured and characterized for proof-of-concept demonstration purposes, showing a fairly close agreement between EM simulations and measurements.

  • From ashes to porous hierarchical nanocarbon electrode: Upcycling secondary waste materials through self-catalytic chemical vapour deposition
    • Maciej Głowacki
    • Katarzyna Karpienko
    • Maciej Wróbel
    • Karol Szczodrowski
    • Chiara Giosuè
    • Gianni Barucca
    • Maria Letizia Ruello
    • Robert Bogdanowicz
    • Mattia Pierpaoli
    2024 Full text Sustainable Materials and Technologies

    Metal and metal oxide particles are abundant in various ash-based wastes. Utilizing these as catalyst sources for the fabrication of carbon nanomaterials could present a valuable approach to reduce our reliance on non-renewable and costly catalyst sources, thereby facilitating large-scale nanomaterial production. In this context, secondary waste materials (SWMs) are by-products resulting from the (complete or partial) combustion of carbon-rich sources or other industrial processes, the disposal of which poses a serious environmental problem. In this study, we demonstrate a novel strategy to upcycle SWMs as catalysts, as received, for the growth of carbon nanoarchitectured electrodes through microwave plasma-enhanced chemical vapour deposition (MPECVD), without the need for functionalization. Firstly, 10 SWMs were selected to fabricate porous hierarchical nanocarbon (PHN) electrodes by phase-inversion and subsequent catalytic MPECVD growth. Secondly, distinct growth conditions, both in the presence and absence of CH4 as an external carbon source were applied, resulting in conductive electrodes, on which acetaminophen oxidation was performed. Results show that not all SWMs, despite originating from similar processes, work as a catalyst. In particular, principal component analysis suggests the presence of calcium oxosilicate and calcium‑magnesium‑iron carbonate as potential catalysts, which are present in two SWMs. Contrary to what expected, the occurrence of metals, such as Fe, Ni, is not a sufficient factor for the catalytic growth of carbon nanostructure. Interestingly, water vapour adsorption isotherms suggest the formation of different porous networks according to the specific SWMs. Finally, the development of waste-derived catalysts fosters the concept of upcycling, converting waste into higher-value products, thus closing the loop on resource utilization and minimizing waste generation.

  • From creative writing, virtual environments to nature-based solutions: linking research and education to facilitate transition from sustainable to regenerative cities
    • Lucyna Nyka
    • Anahita Azadgar
    • Katarina Larsen
    • Pedro Ressano Garcia
    2024 Full text Global Journal of Engineering Education

    Challenges related to the climate crisis and its consequences, such as rising sea levels, urban heat islands or floods, engender pressure on architectural education. Sustainable design often inclines to regenerative one - an emerging trend focused on the restorative power of architecture. The question appears upon the tools and methods that would facilitate both students and academics to address new challenges. This article offers insights into one of such methods based on the integration of students into research programmes. The European Union’s Horizon 2020 research project SOS Climate Waterfront and follow-up interdisciplinary courses and events offered to students at Gdańsk University of Technology, Poland; KTH Royal Institute of Technology, Stockholm, Sweden; and Laval University, Quebec City, Quebec, Canada, are presented to illustrate this process. Starting with research by design approaches, and continuing with follow-up initiatives, groups of students gradually extend their areas of experimentation empowering urban designs with nature-based solutions (NBS), building their critical reflection through an immersion in the science-art-engineering nexus, virtual experience of nature or through creative writing about climate futures. Published, exhibited and awarded students’ works confirm numerous benefits and efficacy of the proposed research-based architectural education.

  • From flow to jamming: Lattice Gas Automaton simulations in granular materials
    • Mohamed Gaber
    • Raquel H. Ribeiro
    • Jan Kozicki
    2024 POWDER TECHNOLOGY

    We introduce the first extension of a Lattice Gas Automaton (LGA) model to accurately replicate observed emergent phenomena in granular materials with a special focus on previously unexplored jamming transitions by incorporating gravitational effects, energy dissipation in particle collisions, and wall friction. We successfully reproduce flow rate evolution, density wave formation, and jamming transition observed in experiments. We also explore the critical density at which jamming becomes probable. This research advances our understanding of granular dynamics and offers insights into the jamming behavior of granular materials.

  • From phosphanylphosphaalkenes to coordination copper and silver polymers containing P–P bonds
    • Aleksandra Ziółkowska
    • Marta Prześniak-Welenc
    • Tomasz Kruczyński
    • Michael Gamer
    • Łukasz Ponikiewski
    2024 DALTON TRANSACTIONS

    This study was focused on the activation of the C[double bond, length as m-dash]P bond via reactions of Ph2C[double bond, length as m-dash]P-PtBu2 (1) with 1,6-hexanediol and selected dithiols (1,4-butanedithiol, 1,4-benzenedithiol and 1,4-benzenedimethanethiol). These reactions proceed according to a 1,2-addition mechanism, providing new compounds with formulas {(Ph)2(H)C-P-PtBu2}{μ2-(O-(CH2)6-O)}{tBu2P-P-C(H)(Ph)2} (2), {(Ph)2(H)C-P-PtBu2}{μ2-(S-(CH2)4-S)}{tBu2P-P-C(H)(Ph)2} (3a), {(Ph)2(H)C-P-PtBu2}{μ2-(S-C6H4-S)}{tBu2P-P-C(H)(Ph)2} (3b), and {(Ph)2(H)C-P-PtBu2}{μ2-(S-CH2-C6H4-CH2-S)}{tBu2P-P-C(H)(Ph)2} (3c). Next, the reactions of 3a and 3c with metal chlorides led to the growth of desired coordination polymers of copper(I) and silver(I). All the obtained compounds remained stable under atmospheric conditions.

  • FRP-based reinforcement coatings of steel with application prospects in ships and offshore structures: a review
    • Abu Al Hassan
    • Krzysztof Wołoszyk
    • Przemysław Krata
    2024 Ships and Offshore Structures

    Latest research on novel FRP-based anti-corrosion structural coatings (for enhancing structural capacity and strengthening the coating layer) is discussed with application prospects for ships and offshore structures. In the marine environment, structures constantly face corrosion and fatigue cracks. Combining this with high operational and wave loads, it might cause a structural collapse. Recently, polymer composites have been studied for possible reinforcement, especially for steel structures in civil engineering. It is important to assess their effectiveness and review of research on the fatigue, tensile, buckling, and debonding properties of fibre-based structural coatings is given and summarised. Most research focused on carbon fibre reinforced composites. Resins matrices other than epoxy, behaviour on corroded steel, ply orientation, and pre-stress level are still untapped adequately. Similarly, another types of fibres than carbon and their hybrids are still insufficiently examined. Although such research direction is promising, the need for future research is highlighted and given in detail.

  • Fuel price, income and road safety as determinants of the level of the population’s economic well-being in Poland
    • Oleksandr Melnychenko
    • Tetiana Osadcha
    • Tetyana Kalna-Dubinyuk
    2024 AIP Conference Proceedings

    The opportunity to travel is one of the most favorite human activities, given that on a trip a person gets new knowledge, impressions and positive emotions. Recreational trips occupy a prominent place in the concept of the economics of happiness, and the study of factors that influence decision-making regarding travel is important for forecasting the number of tourists, infrastructure development, income and expenses of businesses and authorities. Using the panel data representative of Poland, the authors concluded that the price of fuel and the level of actual income are not key factors for travelers. At the same time, the proposed model gives an error of forecasting the number of tourists less than 1% on average for the entire period of research of monthly data from January 2014 to May 2022 on the cost of fuel at gas stations, the level of population’s income, the level of inflation and the level of drivers’ decency on the road. The obtained data can be used to calculate estimates of the flow of tourists, the level of welfare and happiness of the society.

  • Future opportunities for products derived from black soldier fly (BSF) treatment as animal feed and fertilizer - A systematic review
    • Shahida Anusha Siddiqui
    • Ankush Subhash Gadge
    • Muzaffar Hasan
    • Teguh Rahayu
    • Sergey Nikolaevich Povetkin
    • Ito Fernando
    • Roberto Castro Munoz
    2024 Full text ENVIRONMENT DEVELOPMENT AND SUSTAINABILITY

    The pursuit of novel food products with good nutritional value for both direct and indirect human consumption is crucial. Given the nutritional benefits of insects and the sustainability of this sort of farming, using them as food for farmed animals is a promising alternative. In this regard, the black soldier fly (Hermetia illucens) is most capable of efficiently converting a wide variety of organic materials, from food waste to manure, into insect biomass generating value and closing nutrient loops as they reduce pollution and costs. Their larvae have 29% fat and 42% crude protein, yet they have more saturated fats than most insects. They don't concentrate hazards such as mycotoxins or insecticides. Although rapid development is expected, insects remain underutilized in the animal feed industry mainly due to technical, financial, and regulatory barriers. The social stigmas and legal prohibitions against eating organisms that eat waste are added to extant taboos facing insect consumption. Bridging the knowledge gap is crucial to bring together stakeholders and to better understand the opportunities and challenges of this novel industry, so as to develop guidelines on producing insects on an industrial scale to facilitate the wider use of BSF products as animal feed, and fertilizer.

  • Game theory-based virtual machine migration for energy sustainability in cloud data centers
    • Francisco Javier Maldonado-Carrascosa
    • Sebastián García-Galán
    • Manuel Valverde-Ibáñez
    • Tomasz Marciniak
    • Małgorzata Szczerska
    • Nicolás Ruiz-Reyes
    2024 Full text APPLIED ENERGY

    As the demand for cloud computing services increases, optimizing resource allocation and energy consumption has become a key factor in achieving sustainability in cloud environments. This paper presents a novel approach to address these challenges through an optimized virtual machine (VM) migration strategy that employs a game-theoretic approach based on particle swarm optimization (PSO) (PSO-GTA). The proposed approach leverages the collaborative and competitive dynamics of Game Theory to minimize energy consumption while using renewable energy. In this context, the game is represented by the swarm, where each player, embodied by particles, carries both competitive and cooperative elements essential to shape the collective behavior of the swarm. PSO is integrated to refine migration decisions, improving global convergence and optimizing the allocation of VMs to hosts. Through extensive simulations and performance evaluations, the proposed approach demonstrates significant improvements in resource utilization and energy efficiency, promoting sustainability in cloud computing environments. This research contributes to the development of environmentally friendly cloud computing systems, thus ensuring the delivery of energy-efficient cloud computing. The results demonstrate that the proposed approach outperforms fuzzy and genetic methods in terms of renewable energy usage. The PSO-GTA algorithm consistently outperforms Q-Learning, Pittsburgh and KASIA across three simulation scenarios with varying cloudlet dynamics, showcasing its efficiency and adaptability, and yielding improvements ranging from 0.68% to 5.32% over baseline results in nine simulations.