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Gdańsk University of Technology

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  • Influence of stabilizing osmolytes on hen egg white lysozyme fibrillation
    • Jarosław Wawer
    • Emilia Kaczkowska
    • Jakub Karczewski
    • Danuta Augustin-Nowacka
    • Joanna Krakowiak
    2022 JOURNAL OF BIOMOLECULAR STRUCTURE & DYNAMICS

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  • Influence of Surface Modification of Titanium and Its Alloys for Medical Implants on Their Corrosion Behavior
    • Łukasz Pawłowski
    • Magda Rościszewska
    • Majkowska-marzec Beata
    • Magdalena Jażdżewska
    • Michał Bartmański
    • Andrzej Zieliński
    • Natalia Tybuszewska
    • Pamela Samsel
    2022 Full text Materials

    Titanium and its alloys are often used for long-term implants after their surface treatment. Such surface modification is usually performed to improve biological properties but seldom to increase corrosion resistance. This paper presents research results performed on such metallic materials modified by a variety of techniques: direct voltage anodic oxidation in the presence of fluorides, micro-arc oxidation (MAO), pulse laser treatment, deposition of chitosan, biodegradable Eudragit 100 and poly(4-vinylpyridine (P4VP), carbon nanotubes, nanoparticles of TiO2, and chitosan with Pt (nano Pt) and polymeric dispersant. The open circuit potential, corrosion current density, and potential values were determined by potentiodynamic technique, and microstructures of the surface layers and coatings were characterized by scanning electron microscopy. The results show that despite the applied modifications, the corrosion current density still appears in the region of very low values of some nA/cm2. However, almost all surface modifications, designed principally for the improvement of biological properties, negatively influence corrosion resistance. The reasons for observed effects can vary, such as imperfections and permeability of some coatings or accelerated degradation of biodegradable deposits in simulated body fluids during electrochemical testing. Despite that, all coatings can be accepted for biological applications, and such corrosion testing results are presumed not to be of major importance for their applications in medicine.

  • Influence of the Shear Cap Size and Stiffness on the Distribution of Shear Forces in Flat Slabs
    • Maciej Grabski
    • Andrzej Ambroziak
    2022 Full text Materials

    The scope of this paper is to investigate analytically and numerically the influence of shear cap size and stiffness on the distribution of shear forces in flat slabs in a slab–column-connections-reinforced concrete structure. The effect of support (shear cap) stiffness on the calculation of the length of the shear control perimeter according to the available methods is presented. Based on the analysis, the authors indicate in what range of support stiffness the corner concentrations become important in the calculation of the punching resistance. For shear caps with high flexibility (≤ 0.5), the concentration of internal forces in the corners does not occur. The authors compare the numerical results obtained from the calculation methods and indicate the correlations, which can be useful guidance for structural designers. In the case of large shear caps, the simplified MC2010 method gives a significantly lower value of the effective control perimeter length compared to more accurate methods. This paper is intended to provide scientists, civil engineers, and designers with guidelines on which factors influence punching shear load capacity of the slab–column connections with shear caps.

  • Influence of the Tool Rotational Speed on Physical and Chemical Properties of Dissimilar Friction-Stir-Welded AA5083/AA6060 Joints
    • Aleksandra Laska
    • Marek Szkodo
    • Pasquale Cavaliere
    • Angelo Perrone
    2022 Full text Metals

    Aluminum alloys have been successfully used in the railroad and automotive industries because of their potential to significantly reduce component weights, and their good mechanical and anti-corrosion properties. Problems with joining aluminum alloys are characterized by low weldability, which influences the need for studies focused on unconventional methods. The environmentally friendly and low-cost friction-stir-welding method enables the material to be joined without melting. In the following study, dissimilar butt joints were produced from AA5083 and AA6060 alloys. A constant tool traverse speed of 100 mm/min and a tool tilt angle of 2º were used, combined with tool rotational speeds of 800, 1000 and 1200 RPM. It was revealed that as the tool speed increases, the hardness in the weld nugget zone increases, due to higher heat input and more effective recrystallization. The highest hardness of the mweld nugget zone was observed for the weld that was produced with the highest tool rotational speed, and was equal to 1.07 GPa, compared to the hardness of both parent materials of 0.75 and 1.15 GPa for AA5083 and AA6060, respectively. mIncreasing the heat input also decreased the hardness of the heat-affected zone, where recrystallization was not bobserved. The lowest density of dislocations with the highest mobility was observed in the heat-affected zone on the AA6060 side, which also contributed to the reduction in strength in this zone. The produced welds exhibited corrosion resistance between both parent materials, with the lowest corrosion current density being 6.935 ± 0.199 µA·cm–2 for the weld that was produced at a tool speed of 1200 RPM.

  • Influence of Urea and Dimethyl Sulfoxide on K-Peptide Fibrillation
    • Jarosław Wawer
    • Jakub Karczewski
    • Robert Aranowski
    • Rafał Piątek
    • Danuta Augustin-Nowacka
    • Piotr Bruździak
    2022 Full text INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    Protein fibrillation leads to formation of amyloids—linear aggregates that are hallmarks of many serious diseases, including Alzheimer’s and Parkinson’s diseases. In this work, we investigate the fibrillation of a short peptide (K-peptide) from the amyloidogenic core of hen egg white lysozyme in the presence of dimethyl sulfoxide or urea. During the studies, a variety of spectroscopic methods were used: fluorescence spectroscopy and the Thioflavin T assay, circular dichroism, Fourier-transform infrared spectroscopy, optical density measurements, dynamic light scattering and intrinsic fluorescence. Additionally, the presence of amyloids was confirmed by atomic force microscopy. The obtained results show that the K-peptide is highly prone to form fibrillar aggregates. The measurements also confirm the weak impact of dimethyl sulfoxide on peptide fibrillation and distinct influence of urea. We believe that the K-peptide has higher amyloidogenic propensity than the whole protein, i.e., hen egg white lysozyme, most likely due to the lack of the first step of amyloidogenesis—partial unfolding of the native structure. Urea influences the second step of K-peptide amyloidogenesis, i.e., folding into amyloids.

  • Influence of User Mobility and Antenna Placement on System Loss in B2B Networks
    • Manuel M. Ferreira
    • Filipe D. Cardoso
    • Sławomir Ambroziak
    • Luis M. Correia
    2022 Full text IEEE Access

    In this paper, the influence of user mobility and on-body antenna placement on system loss in body-to-body communications in indoor and outdoor environments and different mobility scenarios is studied, based on system loss measurements at 2.45 GHz. The novelty of this work lies on the proposal of a classification model to characterise the effect of user mobility and path visibility on system loss, allowing to identify the best set of on-body antenna placements. To quantify the influence of visibility and mobility on the average system loss, a combined score is proposed, allowing to map system loss onto the degree of visibility and mobility that depends on the scenario being considered and on on-body antenna placements. Overall, a good agreement is observed between the proposed classification model and the average measured values of system loss, with the higher values of combined scores being associated with lower values of systems loss. For the cases under study, the average values of system loss are 61.6 dB for the cases of the antennas being positioned only on the front of the body and/or the head, and 64.5 dB if at least one of the antennas is placed on an arm.

  • Influence of Water-Induced Degradation of Polytetrafluoroethylene (PTFE)-Coated Woven Fabrics Mechanical Properties
    • Andrzej Ambroziak
    • Paweł Kłosowski
    2022 Full text Materials

    The impact of water-induced degradation on the mechanical properties of the chosen two PTFE-coated, glass threads woven fabrics is investigated in this paper. The paper begins with a survey of literature concerning the investigation and determination of coated woven fabric properties. The authors carried out the uniaxial tensile tests with an application of flat and curved grips to establish the proper values of the ultimate tensile strength and the longitudinal stiffness of groups of specimens treated with different moisture conditions. Despite the water resistance of the main materials used for fabrics manufacturing, the change of the mechanical properties caused by the influence of water immersion has been noticed. The reduction in the tensile strength resulting under waterlogged is observed in the range from 5% to 16% depending on the type of investigated coated woven fabric and direction of weft or warp.

  • Inhibitive effect of sodium molybdate on corrosion of AZ31 magnesium alloy in chloride solutions
    • Maria Osipenko
    • Dmitry Kharitonov
    • Aliaksandr Kasach
    • Jacek Ryl
    • Janusz Adamiec
    • Irina Kurilo
    2022 ELECTROCHIMICA ACTA

    In this work, corrosion inhibition of the AZ31 magnesium alloy was investigated in NaCl solutions containing different amounts of sodium molybdate inhibitor. Electrochemical, hydrogen evolution, microscopic, and spectroscopic experiments were utilized to examine the mechanism of corrosion inhibition by molybdates. The results showed that Na2MoO4 inhibitor provides reliable inhibition at high concentrations (150 mM). Surface examination by Raman and XPS spectroscopy confirmed the formation of a protective surface layer of mixed Mo(VI, V, IV) species. Based on these results, the mechanism of corrosion inhibition of the AZ31 alloy by aqueous molybdates was proposed.

  • Inhibitors of glucosamine-6-phosphate synthase as potential antimicrobials or antidiabetics – synthesis and properties
    • Joanna Stefaniak
    • Michał Nowak
    • Marek Wojciechowski
    • Sławomir Milewski
    • Andrzej Skwarecki
    2022 Full text JOURNAL OF ENZYME INHIBITION AND MEDICINAL CHEMISTRY

    Glucosamine-6-phosphate synthase (GlcN-6-P synthase) is known as a promising target for antimicrobial agents and antidiabetics. Several compounds of natural or synthetic origin have been identified as inhibitors of this enzyme. This set comprises highly selective L-glutamine, amino sugar phosphate or transition state intermediate cis-enolamine analogues. Relatively low antimicrobial activity of these inhibitors, poorly penetrating microbial cell membranes, has been improved using the pro-drug approach. On the other hand, a number of heterocyclic and polycyclic compounds demonstrating antimicrobial activity have been presented as putative inhibitors of the enzyme, based on the results of molecular docking to GlcN-6-P synthase matrix. The most active compounds of this group could be considered promising leads for development of novel antimicrobial drugs or antidiabetics, provided their selective toxicity is confirmed.

  • Inline Microstrip Bandpass Filter With Two Transmission Zeros and Increased Order Using Spurious Resonance of Frequency-Dependent Inverter
    • Maciej Jasiński
    • Muhammad Yameen Sandhu
    • Adam Lamęcki
    • Roberto Gómez-García
    • Michał Mrozowski
    2022 Full text

    A design method for a class of fourth-order inline microstrip bandpass filter with two transmission zeros and 20% fractional bandwidth is presented. The filter consists of two quarter-wavelength transmission-line resonators coupled by a frequency-dependent inverter. The inverter is composed of two open-ended stubs that are connected by an interdigital capacitor and introduces two poles and two transmission zeros in the filter response. One of these poles is obtained from the spurious resonance of the capacitor, which leads to a very compact filter structure. An equivalent circuit model of the frequencydependent inverter is provided along with a detailed couplingmatrix-based synthesis procedure to design the filter prototype. The design theory is validated with a constructed 2-GHz proofof-concept prototype. Measured results are in close agreement with the synthesis and EM-simulated ones, hence verifying the devised design approach.

  • Inline Microwave Filters With N+1 Transmission Zeros Generated by Frequency-Variant Couplings: Coupling-Matrix-Based Synthesis and Design
    • Martyna Mul
    • Maciej Jasiński
    • Adam Lamęcki
    • Roberto Gómez-García
    • Michał Mrozowski
    2022 Full text IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS

    A general coupling-matrix-based synthesis methodology for inline Nth-order microwave bandpass filters (BPFs) with frequency-variant reactive-type couplings that generate N+1 transmission zeros (TZs) is presented in this brief. The proposed approach exploits the formulation of the synthesis problem as three inverse nonlinear eigenvalue problems (INEVPs) so that the coupling matrix is built from their sets of eigenvalues. For this purpose, an optimization nonlinear least-squares procedure is employed. The theoretical foundations of the engineered INEVP coupling-matrix-based synthesis framework are described. In addition, its effectiveness is verified through various synthesis examples of a third-order BPF with four TZs based on different circuit models. Moreover, as experimental validation, a 2.4-GHz microstrip prototype of the distributed-element BPF synthesis example is built and measured.

  • Innovative Bidirectional Isolated High-Power Density On-Board Charge for Vehicle-to-Grid
    • Roman Hrbáč
    • Libor Hrdina
    • Vaclav Kolar
    • Zdenek Slanina
    • Vojtech Blazek
    • Tomas Vantuch
    • Mikołaj Bartłomiejczyk
    • Stanislav Misak
    2022 Full text SENSORS

    This paper deals with developing and implementing a bidirectional galvanically isolated on-board charger of a high-power density. The power density of the new charger was 4 kW/kg and 2.46 kW/dm3, and the maximum efficiency was 96.4% at 3.4 kW. Due to the requirement to achieve a high-power density, a single-stage inverter topology was used. Regarding switching losses, due to the topology of the circuit with so-called hard switching, the switching frequency was set to 150 kHz. A laboratory prototype was built to verify the properties and operating principles of the described charger topology. The on-board charger has been tested in a microgrid test platform. Due to the parasitic properties of the transformer and other electronic components, overvoltage with subsequent oscillations occurred on the primary side of the transformer and damped resonance on its secondary side. These parasitic properties caused interference and especially voltage stress on the semiconductor elements. These undesirable phenomena have been eliminated by adding an active element to the charger topology and a new transistor control strategy. This new switching control strategy of transistors has been patented.

  • Innowacyjne zastosowanie betonu jamistego PERVIA, jako warstwy odsączającej w tunelu na węźle MPL Okęcie w Warszawie
    • Michał Kałużyński
    • Anna Banaś
    • Andrzej Kuryłowicz
    2022 Full text

    Choć beton jamisty jest stosowany w budownictwie od wielu lat, to mimo swoich wyjątkowych właściwości filtracyjnych jest często niedocenianym elementem budowlanym. Wynika to z jego niewystarczającej wytrzymałości, która spowodowana jest brakiem frakcji piaskowej. Patrząc na problem z drugiej strony, właściwe odwodnienie nawierzchni komunikacyjnych jest podstawowym zadaniem, które musi rozwiązać projektant. Szybkie odprowadzenie wody z powierzchni drogi jest niezbędne, gdyż odpowiada za prawidłową przyczepność opony do nawierzchni, a tym samym za bezpieczeństwo ruchu drogowego. W przedstawionym w niniejszej pracy tunelu, ze względu na uwarunkowania konstrukcyjne, w tym niewielką wysokość skrajni drogowej, poszukiwano rozwiązania, które będzie optymalne zarówno pod względem szybkiego odprowadzania wody, jak i zapewnienia odpowiedniej wytrzymałości i zapobiegania powstawaniu kolein w nawierzchni. Zdecydowano się na zastosowanie betonu jamistego PERVIA jako podbudowy i warstwy filtracyjnej jezdni asfaltowej. To innowacyjne rozwiązanie nie tylko rozwiązało problem przesiąkania wody przez płytę denną, ale także sprzyja odpowiedzialnej gospodarce wodnej, zwiększając poziom wód gruntowych i zachowując równowagę ekologiczną.

  • Innowacyjny system do lokalizacji zasobów dla poprawy efektywności i bezpieczeństwa w służbie zdrowia
    • Mateusz Rzymowski
    • Mateusz Groth
    • Krzysztof Nyka
    • Łukasz Kulas
    2022 Full text Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    Przedstawiono innowacyjne podejście do lokalizacji wewnątrzbudynkowej, które może zostać wykorzystane do podniesienia bezpieczeństwa i efektywności w służbie zdrowia. Opiera się ono na stacjach bazowych pracujących w standardzie Bluetooth Low Energy (BLE), wykorzystujących dedykowany moduł bezprzewodowy. zawierający układ scalony Nordic Semiconductor nRF5284 oraz na antenach rekonfigurowalnych, w których możliwe jest elektryczne przełączanie kierunku wiązki głównej. Zaproponowany algorytm lokalizacji umożliwia odnajdywanie nieznanych pozycji etykiet radiowych BLE, używając wyłącznie mocy sygnału odebranego bez wykonywania dodatkowych wcześniejszych kalibracji i wykorzystując tylko pojedynczą stację bazową oraz etykiety referencyjne BLE przyczepione do ścian. Pomiary wykonane w rzeczywistym środowisku wewnątrz budynku pokazują, że zaproponowane podejście z powodzeniem może zostać wykorzystane w obszarze służby zdrowia i zapewnia wyniki lokalizacji na akceptowalnym poziomie przy jednoczesnym niskim poziomie całkowitych kosztów instalacji oraz utrzymania systemu w porównaniu do komercyjnie dostępnych systemów lokalizacji.

  • In-Reactor Polypropylene Functionalization─The Influence of Catalyst Structures and Reaction Conditions on the Catalytic Performance
    • Miloud Bouyahyi
    • Lidia Jasińska-Walc
    • Rob Duchateau
    • Muhammad Naseem Akhtar
    • E. A. Jaseer
    • Rajesh Theravalappil
    • Nestor Garcia
    2022 Full text MACROMOLECULES

    To unravel the relationship between silylene-bridged metallocene catalyst structures and polymerization conditions and their effect on the performance in in-reactor functionalization of polypropylene, the behaviors of rac-Me2Si(2-Me-4-Ph-Ind)2ZrCl2/MMAO, rac-Me2Si(Ind)2ZrCl2, rac-Me2Si(2-Me-4-Ph-Ind)2HfCl2, and rac-Me2Si(Ind)2HfCl2 in propylene/aluminum alkyl-passivated 10-undecen-1-ol copolymerization were compared. Kinetic analysis revealed higher catalytic activities for zirconocenes compared to analogous hafnocenes. Both the zirconocene and hafnocene with substituted indenyl ligands afforded a higher molecular weight capability, improved stereo-selectivity, and enhanced ability to incorporate functionalized comonomers compared to their non-substituted congeners. An in-depth study of polypropylene functionalization using the best performing catalyst system, rac-Me2Si(2-Me-4-Ph-Ind)2ZrCl2/MMAO, at temperatures ranging from 40 to 100 °C, revealed a linear inversely proportional correlation of polymerization temperature with functionalized comonomer reactivity (↑Tp → ↓ r1), copolymer molecular weight (↑Tp → ↓Mn), and melting temperature (↑Tp → ↓Tm). While performing well under standard laboratory polymerization conditions, rac-Me2Si(2-Me-4-Ph-Ind)2ZrCl2/MMAO showed limited molecular weight and stereo-selectivity capabilities under high-temperature (130–150 °C) solution process conditions. Although immobilization of rac-Me2Si(2-Me-4-Ph-Ind)2ZrCl2 onto silica, allowing it to be used under industrially relevant slurry and gas-phase conditions, led to an active catalyst, it failed to incorporate any functionalized comonomer.

  • Insight into Potassium Vanadates as Visible-Light-Driven Photocatalysts: Synthesis of V(IV)-Rich Nano/Microstructures for the Photodegradation of Methylene Blue
    • Małgorzata Nadolska-Dawidowska
    • Mariusz Szkoda
    • Konrad Trzciński
    • Paweł Niedziałkowski
    • Jacek Ryl
    • Aleksandra Dorota Mielewczyk-Gryń
    • Karolina Górnicka
    • Marta Prześniak-Welenc
    2022 Full text INORGANIC CHEMISTRY

    Photocatalysis is regarded as a promising tool for wastewater remediation. In recent years, many studies have focused on investigating novel photocatalysts driven by visible light. In this study, K2V6O16·nH2O nanobelts and KV3O8 microplatelets were synthesized and investigated as photocatalysts. Samples were obtained via the facile method based on liquid-phase exfoliation with ion exchange. By changing the synthesis temperature (20–80 °C), different compositions, morphologies, and V4+/V5+ ratios were obtained and investigated as photocatalysts for organic dye degradation. Potassium vanadates’ structural, morphological, and optical properties were characterized using X-ray diffraction(XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Physical Property Measurement System (PPMS), thermogravimetric analysis (TGA) with mass spectrometry (MS), N2 adsorption, scanning electron microscopy (SEM), photoluminescence (PL), and UV–vis diffuse reflectance spectroscopy (DRS). Synthesized K2V6O16·nH2O and KV3O8 showed an efficient absorption in the visible wavelength region with a narrow band gap energy of 1.80 and 1.91 eV, respectively. Their photocatalytic activity was evaluated by the degradation of methylene blue (MB) under simulated solar light illumination. The KV3O8 microplatelets exhibited the greatest photocatalytic activity, resulting in more than 90% degradation of the dye within the first 30 min. It is suggested that the observed excellent photocatalytic performance is attributed to the high content of V4+ species. Furthermore, the influence of active species was investigated, and the mechanism responsible for the photodegradation of the MB dye was discussed for the first time for potassium vanadates.

  • Insights into Stoichiometry Adjustments Governing the Performance of Flexible Foamed Polyurethane/Ground Tire Rubber Composites
    • Adam Olszewski
    • Paulina Kosmela
    • Wiktoria Żukowska
    • Paweł Wojtasz
    • Mariusz Szczepański
    • Mateusz Barczewski
    • Łukasz Zedler
    • Krzysztof Formela
    • Aleksander Hejna
    2022 Full text Polymers

    Polyurethanes (PU) are widely applied in the industry due to their tunable performance adjusted by changes in the isocyanate index—stoichiometric balance between isocyanate and hydroxyl groups. This balance is affected by the incorporation of modifiers of fillers into the PU matrix and is especially crucial for PU foams due to the additional role of isocyanates—foaming of the material. Despite the awareness of the issue underlined in research works, the contribution of additives into formulations is often omitted, adversely impacting foams’ performance. Herein, flexible foamed PU/ground tire rubber (GTR) composites containing 12 different types of modified GTR particles differing by hydroxyl value (LOH) (from 45.05 to 88.49 mg KOH/g) were prepared. The impact of GTR functionalities on the mechanical, thermomechanical, and thermal performance of composites prepared with and without considering the LOH of fillers was assessed. Formulation adjustments induced changes in tensile strength (92–218% of the initial value), elongation at break (78–100%), tensile toughness (100–185%), compressive strength (156–343%), and compressive toughness (166–310%) proportional to the shift of glass transition temperatures (3.4–12.3 °C) caused by the additional isocyanates’ reactions yielding structure stiffening. On the other hand, formulation adjustments reduced composites’ thermal degradation onset due to the inferior thermal stability of hard segments compared to soft segments. Generally, changes in the composites’ performance resulting from formulation adjustments were proportional to the hydroxyl values of GTR, justifying the applied approach.

  • Insights into the microbial community of treated wastewater, its year-round variability and impact on the receiver, using cultivation, microscopy and amplicon-based methods
    • Agnieszka Kalinowska
    • Mattia Pierpaoli
    • Katarzyna Jankowska
    • Sylwia Fudala-Książek
    • Anna Remiszewska-Skwarek
    • Aneta Łuczkiewicz
    2022 Full text SCIENCE OF THE TOTAL ENVIRONMENT

    Apart from chemical constituents, wastewater treatment plant (WWTP) effluents also release microorganisms that can be important to the receiving water bodies either from a sanitary point of view, or taking to the account the biogeochemical potential of the recipients. However, little is known about the treated wastewater microbial community, its composition, seasonal changes, functions and fate in the waters of the receiver. Thus, this study presents a synergistic approach coupling new and traditional methods: analytical chemistry, classical microbiology (cultivation- and microscopy-based methods), as well as Next Generation Sequencing and a quantitative real-time polymerase chain reaction (qPCR). The results show that in terms of bacterial community composition, treated wastewater differed from the environmental samples, irrespectively if they were related or unrelated to the WWTP effluent discharge. The canonical correspondence analysis (CCA) taking into account chemical parameters and taxonomical biodiversity indirectly confirmed the seasonal deterioration of the treated wastewater quality as a result of temperature-driven change of activated sludge community structure and biomass washout (observed also by DAPI staining). Despite seasonal fluctuations of total suspended solids and inter-related parameters (such as COD, BOD, TN, TP), the treated wastewater quality remained within current discharge limits. It was due to treatment processes intensively adjusted by WWTP operators, particularly those necessary to maintain an appropriate rate of autotrophic processes of nitrification and to support biological phosphorus removal. This can explain the observed microbiome composition similarity among WWTP effluents at high taxonomic levels. Obtained data also suggest that besides wastewater treatment efficiency, WWTP effluents are still sources of both human-related microorganisms as well as bacteria equipped in genes involved in N-cycling. Their potential of participation in nutrients cycling in the receivers is widely unknown and require critical attention and better understanding.

  • Integrated Functional Safety and Cybersecurity Evaluation in a Framework for Business Continuity Management
    • Kazimierz Kosmowski
    • Emilian Piesik
    • Jan Piesik
    • Marcin Śliwiński
    2022 Full text ENERGIES

    This article outlines an integrated functional safety and cybersecurity evaluation approach within a framework for business continuity management (BCM) in energy companies, including those using Industry 4.0 business and technical solutions. In such companies, information and communication technology (ICT), and industrial automation and control system (IACS) play important roles. Using advanced technologies in modern manufacturing systems and process plants can, however, create management impediments due to the openness of these technologies to external systems and networks via various communication channels. This makes company assets and resources potentially vulnerable to risks, e.g., due to cyber-attacks. In the BCM-oriented approach proposed here, both preventive and recovery activities are considered in light of engineering best practices and selected international standards, reports, and domain publications.

  • Integrated Three-Level Dual-Phase Inverter
    • Charles Odeh
    • Arkadiusz Lewicki
    • Marcin Morawiec
    • Andrzej Jąderko
    2022 Full text ENERGIES

    In view of reducing the number of inverter legs that provide dual-phase, three-level output voltages (as may be needed in an uninterruptible power supply), and that also provide a wide range of output frequencies (as needed in an advanced motor drive system with wide speed ranges), a three-level, dual-phase inverter topology is presented in this paper. Its three-level attribute was based on the F-type inverter topological concept, and its dual-output feature was based on the common representation of the inverter-leg concept. The proposed inverter could deliver single- and three-phase voltages to corresponding one- and three-phase loads, in common or different frequency modes of operation. A boundary between these modes of operation was established for the proposed inverter. An additional possibility of either operation in the one-phase or the three-phase system was offered by the inverter configuration. A modified carrier-based sinusoidal pulse-width modulation scheme is presented for the control of the inverter topology. The performances of the dual-phase inverter are given in the simulation results and demonstrated with a hardware prototype.

  • Integrating conventional nitrogen removal with anammox in wastewater treatment systems: Microbial metabolism, sustainability and challenges
    • Hussein Al-Hazmi
    • Gamal K.hassan
    • Mojtaba Maktabifard
    • Dominika Derwis
    • Joanna Majtacz
    • Jacek Mąkinia
    2022 ENVIRONMENTAL RESEARCH

    The various forms of nitrogen (N), including ammonium (NH4+), nitrite (NO2−), and nitrate (NO3−), present in wastewaters can create critical biotic stress and can lead to hazardous phenomena that cause imbalances in biological diversity. Thus, biological nitrogen removal (BNR) from wastewaters is considered to be imperatively urgent. Therefore, anammox-based systems, i.e. partial nitrification and anaerobic ammonium oxidation (PN/anammox) and partial denitrification and anammox (PD/anammox) have been universally acknowledged to consider as alternatives, promising and cost-effective technologies for sustainable N removal from wastewaters compared to nitrification-denitrification processes. This review comprehensively presents and discusses the latest advances in BNR technologies, including traditional nitrification-denitrification and anammox-based systems. To a deep understanding of a better-controlled combining anammox with traditional processes, the microbial community diversity and metabolism, as well as, biomass morphological characteristics were clearly reviewed in the anammox-based systems. Explaining simultaneous microbial competition and control of crucial operation parameters in single-stage anammox-based processes in terms of optimization and economic benefits makes this contribution a different vision from available review papers. The most important sustainability indicators, including global warming potential (GWP), carbon footprint (CF) and energy behaviours were explored to evaluate the sustainability of BNR processes in wastewater treatment. Additionally, the challenges and solutions for BNR processes are extensively discussed. In summary, this review helps facilitate a critical understanding of N removal technologies. It is confirmed that sustainability and saving energy would be achieved by anammox-based systems, thereby could be encouraged future outcomes for a sustainable N removal economy.

  • Integration Data Model of the Bathymetric Monitoring System for Shallow Waterbodies Using UAV and USV Platforms
    • Oktawia Lewicka
    • Mariusz Specht
    • Andrzej Stateczny
    • Cezary Specht
    • Gino Dardanelli
    • David Brčić
    • Bartosz Szostak
    • Armin Halicki
    • Marcin Stateczny
    • Szymon Widźgowski
    2022 Full text Remote Sensing

    Changes in the seafloor relief are particularly noticeable in shallow waterbodies (at depths up to several metres), where they are of significance for human safety and environmental protection, as well as for which the highest measurement accuracy is required. The aim of this publication is to present the integration data model of the bathymetric monitoring system for shallow waterbodies using Unmanned Aerial Vehicles (UAV) and Unmanned Surface Vehicles (USV). As part of this model, three technology components will be created: a hydroacoustic and optoelectronic data integration component proposed by Dąbrowski et al., a radiometric depth determination component based on optoelectronic data using the Support Vector Regression (SVR) method, and a coastline extraction component proposed by Xu et al. Thanks to them, it will be possible to cover the entire area with measurements in the coastal zone, in particular between the shallow waterbody coastline and the min. isobath recorded by the echo sounder (the area is lacking actual measurement data). Multisensor data fusion obtained using Global Navigation Satellite System (GNSS)/Inertial Navigation System (INS), Light Detection And Ranging (LiDAR), Real Time Kinematic (RTK), UAV, and USV will allow to meet the requirements provided for the International Hydrographic Organization (IHO) Special Order (horizontal position error ≤ 2 m (p = 0.95), vertical position error ≤ 0.25 m (p = 0.95)). To this end, bathymetric and photogrammetric measurements shall be carried out under appropriate conditions. The water transparency in the tested waterbody should be at least 2 m. Hydrographic surveys shall be performed in windless weather and the water level is 0 in the Douglas sea scale (no waves or sea currents). However, the mission with the use of an UAV should take place in appropriate meteorological conditions, i.e., no precipitation, windless weather (wind speed not exceeding 6–7 m/s), sunny day.

  • Integration of antifouling properties into epoxy coatings: a review
    • P. Poornima Vijayan
    • Krzysztof Formela
    • Mohammad Saeb
    • P. G. Chithra
    • Sabu Thomas
    2022 Journal of Coatings Technology and Research

    he need for nontoxic antifouling coatings has encouraged material scientists to develop a class of organic coatings for diverse applications. As a versatile thermosetting resin and well known for coating application, antifouling characteristics have been integrated into epoxy along with anticorrosion and adhesive functions. Accordingly, both micro- and macro-biofoulings have been successfully controlled by using epoxy-based antifouling coatings. Epoxy nanocomposites, silicon-grafted epoxy, epoxy-aided conductive polymer blends, and nanocomposites are important antifouling epoxy variants far and wide examined in developing epoxy-based coatings. Besides, some purpose-specific multifunctional smart coatings based on epoxy with antifouling features are used to integrate several functions into one material. This review discusses various types of epoxy-based antifouling coatings. The ability of nanomaterials, siloxanes, and conducting polymers to induce antifouling activity into the epoxy and corresponding antifouling mechanisms is also covered. The review concludes with the enormous potential of antifouling epoxy coatings as cost-effective, environmentally sustainable solution to biofouling in diverse industrial applications. Finally, the future ahead of antifouling epoxy coating is patterned.

  • Inteligentne rozwiązania z zakresu post-processingu dla drukowanych elementów
    • Dawid Zieliński
    2022 Full text Tworzywa Sztuczne w Przemyśle

    Coraz większe zainteresowanie i wykorzystywanie drukowanych elementów w różnych gałęziach przemysłu wiąże się ze stosowaniem odpowiednich metod ich obróbki wykańczającej tzw. post-processing. Tego typu metody służą zazwyczaj poprawie ogólnego wyglądu wydruków, a także ich właściwości mechanicznych i eksploatacyjnych. Celem niniejszego artykułu jest zaprezentowanie wybranych i nowoczesnych rozwiązań z zakresu post-processingu na przykładzie zaawanasowanych urządzeń firmy Addiblast by FerroECOBlast, których produkty są również oferowane przez firmę BIBUS MENOS Sp. z o.o.

  • Inteligentne zarządzanie usługami chmurowymi
    • Henryk Krawczyk
    • Piotr Orzechowski
    2022

    Rozwój chmur obliczeniowych stanowi wyzwanie dla nowych efektywnych metod zarządzania zasobami chmurowymi, zwłaszcza, że oprócz usług typu SaaS rozwija się nowe kategorie usług jak obliczenia brzegowe czy wielochmurowe. W pracy zaproponowano ogólny model zarządzania usługami oraz efektywne procedury alokacji zasobów. Podkreślono potrzebę oszacowania parametrów zasobów chmury by zapewnić wykonanie żądanych usług. Przedstawiono również przykładowe rozwiązanie bazujące na sztucznej inteligencji, wdrożone w chmurze TASKcloud rozwijanej w CI TASK.

  • Intelligence Augmentation and Amplification: Approaches, Tools, and Case Studies
    • Edward Szczerbicki
    • Ngoc-Thanh Nguyen
    2022 Full text CYBERNETICS AND SYSTEMS

    Most experts agree that truly intelligent artificial system is yet to be developed. The main issue that still remains a challenge is imposing trust and explainability into such systems. However, is full replication of human intelligence really desirable key aim in intelligence related technology and research? This is where the concept of augmented intelligence comes into play. It is an alternative conceptualization of artificial intelligence (AI) that focuses on AI's assistive role, emphasizing the fact that cognitive technology is designed to enhance human intelligence rather 2 than simply replacing it. Visionaries believe that one of the most promising potentials for intelligence augmentation is the creation of a hybrid biological and non-biological thinking as a way to “supercharge” the human brain.

  • Intelligent Audio Signal Processing − Do We Still Need Annotated Datasets?
    • Bożena Kostek
    2022 Full text

    In this paper, intelligent audio signal processing examples are shortly described. The focus is, however, on the machine learning approach and datasets needed, especially for deep learning models. Years of intense research produced many important results in this area; however, the goal of fully intelligent signal processing, characterized by its autonomous acting, is not yet achieved. Therefore, a review of state-of-the-art concerning this area is given. The aspect of showing the importance of acquiring an appropriate dataset containing audio samples dedicated to the task is also shown. The paper starts with samples of audio-related datasets resulting from the search engine inquiry. Then, examples of research studies along with results are given. Also, several works carried out by the author and her collaborators are presented. Some thoughts on future work are included with answering a question of whether annotated datasets are still needed.

  • Intelligent Decision Forest Models for Customer Churn Prediction
    • Fatimah E. Usman-Hamzah
    • Abdullateef O. Balogun
    • Luiz Fernando Capretz
    • Hammed Mojeed
    • Saipunidzam Mahamad
    • Shakirat A. Salihu
    • Abimbola G. Akintola
    • Shuib Basri
    • Ramoni Tirimisiyu Amosa
    • Nasiru Kehinde Salahdeen
    2022 Full text Applied Sciences-Basel

    Customer churn is a critical issue impacting enterprises and organizations, particularly in the emerging and highly competitive telecommunications industry. It is important to researchers and industry analysts interested in projecting customer behavior to separate churn from non‐churn consumers. The fundamental incentive is a firm’s intent desire to keep current consumers, along with the exorbitant expense of gaining new ones. Many solutions have been developed to address customer churn prediction (CCP), such as rule‐based and machine learning (ML) solutions. However, the issue of scalability and robustness of rule‐based customer churn solutions is a critical drawback, while the imbalanced nature of churn datasets has a detrimental impact on the prediction efficacy of conventional ML techniques in CCP. As a result, in this study, we developed intelligent decision forest (DF) models for CCP in telecommunication. Specifically, we investigated the prediction performances of the logistic model tree (LMT), random forest (RF), and Functional Trees (FT) as DF models and enhanced DF (LMT, RF, and FT) models based on weighted soft voting and weighted stacking methods. Extensive experimentation was performed to ascertain the efficacy of the suggested DF models utilizing publicly accessible benchmark telecom CCP datasets. The suggested DF models efficiently distinguish churn from non‐churn consumers in the presence of the class imbalance problem. In addition, when compared to baseline and existing ML‐based CCP methods, comparative findings showed that the proposed DF models provided superior prediction performances and optimal solutions for CCP in the telecom industry. Hence, the development and deployment of DF‐based models for CCP and applicable ML tasks are recommended.

  • Intense and stable room-temperature photoluminescence from nanoporous vanadium oxide formed by in-ambient degradation of VI3 crystals
    • Dario Mastrippolito
    • Hanna Świątek
    • Paolo Moras
    • Matteo Jugovac
    • Roberto Gunnella
    • Luca Lozzi
    • Paola Benassi
    • Tomasz Klimczuk
    • Luca Ottaviano
    2022 JOURNAL OF LUMINESCENCE

    Vanadium oxides have attracted research interest because their optoelectronic properties make them optically active with room-temperature photoluminescence (PL) emission, which, however, is not sufficiently intense for real applications. For this reason, many nanostructured vanadium oxides are currently fabricated through several precursors and different treatments to improve the PL efficiency and enhance the PL intensity. Herein, we propose an alternative and facile route to the fabrication of nanoporous vanadium oxide flakes through the spontaneous in-ambient degradation of layered van der Waals VI3 crystal, which is composed of a mixture of V2O5 and V3O7 phases. The as-grown VI3 crystals and the formed nanostructured vanadium oxide have been thoroughly studied using X-ray diffraction (XRD) and Raman spectroscopy to access the structural properties, Xray photoemission spectroscopy (XPS) and synchrotron-based XPS to analyze the electronic core levels and valence bands, scanning electron microscopy (SEM) to access the morphology, and PL spectroscopy to grasp the optoelectronic properties. The nanoporous vanadium oxide system reveals an intense room-temperature PL emission in the red light visible range between 1.7 and 2.0 eV (620 and 730 nm), which is consistent with the V2O5 PL response. Remarkably, the PL emission reaches high intensity compared with those of different V2O5 nanostructures and is stable for months without intensity quenching and energy shifting. This discovery easies the integration of nanostructured vanadium oxides in optoelectronic nanodevices. Besides, the facile methodology proposed here promises to be applied to realize other nanostructured transition metal oxides.

  • Intensification of catechin extraction from the bark of Syzygium cumini using ultrasonication: Optimization, characterization, degradation analysis and kinetic studies
    • Yogesh A. Bhadange
    • Virendra Kumar Saharan
    • Shirish H. Sonawane
    • Grzegorz Boczkaj
    2022 CHEMICAL ENGINEERING AND PROCESSING

    Catechin is a prominent polyphenolic component that possesses various medicinal properties. Present work communicates the intensification and optimization of catechin extraction from the bark of Syzygium cumini tree using stirred reactor, soxhlet, ultrasonic bath, and ultrasonic horn technique. The optimization of several parameters such as type of solvent, solid to solvent ratio (1:100 w/v), speed of agitation (300 RPM), extraction temperature (40 °C), and amplitude (20%) has been done for the maximization of catechin extraction yield. The kinetic (second-order rate mechanism) and degradation analysis (based on LC-MS characterization) have been performed to understand the extraction mechanism, forecast extraction stability, and avoid unwanted catechin degradation during ultrasonication. The effectiveness of different extraction techniques was compared based on the yield of catechin per unit of power dissipated. These studies revealed that ultrasonic horn produced maximum extraction yield (13.8 mg/g) in a shorter time (5 min), consumed less energy (0.2974 kJ), and gave the highest extraction rate (0.0910 g/mg.min) as compared to other techniques. The effectiveness of extraction using the ultrasonic horn was 39.67 mg/g.kJ. A mathematical model using the linear regression method was investigated for the process, which shows numerical correlation and significance factor between the yield and all other parameters.

  • Interdisciplinary research as a form of monument protection and preparation for the investment process on the example of the former Gdańsk Shipyard complex
    • Anna Orchowska-Smolińska
    • Anna Kriegseisen
    • Jakub Szczepański
    2022 Full text Architectus

    The multi-layered heritage of many industrial plants operating until the end of the 20th century creates a particular challenge for conservators, designers and investors. In the process of protecting its values, displaying qualities and managing the property, it is necessary to recognize a wider transformation of technology of the entire plant and the individual functions of its buildings, as well as the context of intangible heritage. An example of this type of complex historical building is the former Gdańsk Shipyard. The subject of the article is an interdisciplinary study of the shipyard complex, during which a research method based on several scales of analysis (in relation to the city, the complex and the facility) was developed. It was based on an in-depth recognition of the shipyard's operation in the 1970s and 1980s, which, due to workers' strikes in the plant and the establishment of NSZZ "Solidarność", had a special impact on constitutionalizing its property status to outstanding values. The authors set themselves the goal of presenting the results of a detailed study of the cultural resources of the shipyard, which included specialists from the shipbuilding industry historically associated with this particular industrial plant. As a result, multi-faceted conservation guidelines were created to set the framework for the protection of the shipyard's cultural resources, conduct conservation and investment works on its premises (material and color template). The summary shows the possibilities of using the presented model of research activities in connection with design activities using the example of an industrial facility prepared for the investment process (former Main Warehouse, the so-called U-Boat Hall).

  • Interference between Land and Sea Logistics Systems. Multifunctional Building System Design Towards Autonomous Integrated Transport Infrastructure
    • Mateusz Gerigk
    2022 Full text TransNav - The International Journal on Marine Navigation and Safety of Sea Transportation

    The research is focused on developing design theory towards efficient multifunctional facilities for logistics supply chains in the contemporary urban city structures. The development of modern systems based on autonomous transport creates new conditions for their management and generates an emerging need to define dedicated functional service structures. An important element of consideration also taken into account is the scenario for large-size unmanned facilities operation in the multifunctional port facility and its connections to power supply from renewable energy sources. Despite the high degree of complexity, modern transport solutions should be focused on optimizing the distribution time and trans-shipment time within the intermodal supply chain as well as provide ecological logistic solutions. Due to the large number of system components, the study presents a simplified database structure allowing for a comprehensive technological overview within the entire system.

  • Interlaboratory Test to Characterize the Cyclic Behavior of Bituminous Interlayers: An Overview of Testing Equipment and Protocols
    • Piotr Jaskuła
    • Dawid Ryś
    • Francesco Canestrari
    • Thomas Attia
    • Hervé Di Benedetto
    • Andrea Graziani
    • Youngsoo Richard Kim
    • Maciej Maliszewski
    • Jorge C. Pais
    • Christophe Petit
    • Christiane Raab
    • Davide Ragni
    • Cesare Sangiorgi
    • Cédric Sauzéat
    • Adam Zofka
    2022

    The performance assessment of multi-layered pavements strongly depends on the mechanical behavior of the interface between bituminous layers. So far, comprehensive studies have been carried out mainly using quasi-static laboratory tests focusing on the interlayer shear strength at failure. However, it is generally recognized that cyclic shear testing will lead to the determination of parameters which are more closely linked to the performance of pavements under traffic loading than the quasi-static shear tests. This paper outlines the research work that has been carried out within the Task Group 3 “Pavement multilayer system” of the RILEM TC 272-PIM. The activities focused on cyclic shear testing of interfaces in bituminous pavements involve an interlaboratory test with nine participating laboratories. The interface behavior was investigated through both direct shear and torque tests on double-layered specimens extracted from lab compacted slabs prepared by one of the laboratories. The different testing equipment and protocols used by the participating laboratories are presented, highlighting the variety of geometries, loading modes, and testing parameters. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.

  • Intermetallic disordered magnet Gd2Pt1.1Ge2.9 and its relation to other AlB2 -type compounds
    • Leszek Litzbarski
    • Michał Winiarski
    • Tomasz Klimczuk
    • Marcin Łapiński
    • M. Pugaczowa-Michalska
    • P. Skokowski
    • Bartłomiej Andrzejewski
    2022 Full text PHYSICAL REVIEW B

    The intermetallic germanide Gd 2 Pt 1.1 Ge 2.9 was synthesized using an arc-melting method. The crystal structure was characterized using powder x-ray diffraction, revealing a disordered ternary AlB 2 -type structure (space group P 6 / m m m , No. 191) with lattice parameters a = 4.2092 ( 1 ) Å and c = 4.0546 ( 2 ) Å . Physical properties were investigated by magnetic susceptibility and heat capacity measurements, which indicated onset of antiferromagnetic order at T t = 8 K . The obtained properties were compared with the ones reported for other members of the AlB 2 -type Gd 2 T Ge 3 ( T = Ni , Cu, and Pd) family. The magnetic ordering in these compounds was discussed in terms of their crystal structure and the influence of Gd ions.

  • Internal imaging of concrete fracture based on elastic waves and ultrasound computed tomography
    • Monika Zielińska
    • Magdalena Rucka
    2022 Full text MEASUREMENT

    The condition assessment of concrete structures belongs to the greatest challenges of non-destructive testing. Monitoring the fracture process of concrete and detecting cracks at the earliest possible stage is a vital aspect to ensure the safety of civil engineering objects. The use of ultrasound tomography enables imaging the internal structure of a tested element. This study aims at the visualization of fracture damage in concrete cubes. The tests are performed on samples made of plain concrete and concrete with fibres. The main contribution of this work is the study of the application of ultrasound transmission tomography to imaging cracks in concrete prisms before and after mechanical degradation in a wedge splitting test. A novel method of determination of the time-of-flight of a wave propagating from a transmitter to a receiver is introduced. The effectiveness of the imaging of fracture damage obtained using ultrasound tomography is proved by X-ray micro-computed tomography.

  • Internationalization and Quality Assurance in Higher Education
    • Karolina Wysocka
    • Christian Jungnickel
    • Katarzyna Szelągowska-Rudzka
    2022 Full text Management

    Internationalization is an inevitable phenomenon among all contemporary higher education institutions (HEIs) in a globalizing world. It is the driving force for development and progress. In course of the last 30 years, it became an inevitable element of HE management. However, it carries along a number of risks, pitfalls, and organizational challenges. To hedge those, quality assurance (QA) is called to the stage. HEIs therefore need not only to search for chances but also to increase the advancement of methods to safeguard the quality of education and research. It is for this reason that a discussion on the mutual evolution and impact of internationalization and QA is required, and this is the aim of this article to combine the issues dialectically. There are tools and institutions within the internationally and nationally developed QA concepts that have the potential and aim to secure the benefits of internationalization.

  • Interplay between Aryl···Perfluoroaryl and Hydrogen Bonding Interactions in Cocrystals of Pentafluorophenol with Molecules of Trigonal Symmetry
    • Jan Alfuth
    • Jarosław Chojnacki
    • Tadeusz Połoński
    • Aleksander Herman
    • Maria Milewska
    • Teresa Olszewska
    2022 Full text CRYSTAL GROWTH & DESIGN

    Cocrystals of seven star-shaped triaryl compounds with pentafluorophenol (pfp) were prepared and structurally characterized by the single-crystal X-ray diffraction method. Cocrystallization of pfp with planar (or almost planar) compounds gave six 3:1 molecular complexes with well-defined layered structures. The layers are composed of alternating pfp3 trimers, linked by hydrogen bonding, and triaryl molecules held together in planes by the weak C–H···F interactions. Stacking interactions of the triaryl-substituted molecules with the perfluorinated rings of pfp are responsible for the overall crystal packing, but most likely also stabilize the trimers in the solid state, as the assembly of the pfp into trimers provide an optimal geometry for the π···π interaction. The layers are flat for the cases of components with almost planar geometry and corrugated for those with more twisted geometry. In the case of nonplanar triphenyl isocyanurate, the pfp cocrystal does not contain pfp3 trimers, the stoichiometry changes from 3:1 to 3:2 (3 refers to pfp), and the packing is mainly controlled by intermolecular O–H···O=C hydrogen bonding.

  • Intracranial electrophysiological recordings from the human brain during memory tasks with pupillometry
    • Jan Cimbalnik
    • Jaromir Dolezal
    • Cagdas Topcu
    • Michał Lech
    • Victoria Marks
    • Boney Joseph
    • Martin Dobias
    • Jamie Van Gompel
    • Gregory Worrell
    • Michał Kucewicz
    2022 Full text Scientific Data

    Data comprise intracranial EEG (iEEG) brain activity represented by stereo EEG (sEEG) signals, recorded from over 100 electrode channels implanted in any one patient across various brain regions. The iEEG signals were recorded in epilepsy patients (N=10) undergoing invasive monitoring and localization of seizures when they were performing a battery of four memory tasks lasting approx. 1 hour in total. Gaze tracking on the task computer screen with estimating the pupil size was also recorded together with behavioral performance. Each dataset comes from one patient with anatomical localization of each electrode contact. Metadata contains labels for the recording channels with behavioral events marked from all tasks, including timing of correct and incorrect vocalization of the remembered stimuli. The iEEG and the pupillometric signals are saved in BIDS data structure to facilitate efficient data sharing and analysis.

  • Introduction to smart solutions for wastewater: Road-mapping the transition to circular economy
    • Giorgio Mannina
    • Dario Presti
    • Ashok Pandey
    • Herman Helness
    • Ranjna Sirohi
    • Jacek Mąkinia
    2022

    Today there is an urgent need to move from a linear to a circular economy approach with special focus to water and environment. Despite the paramount importance, this transition is hampered by barriers which concern not only technological but embrace also organizational, regulatory, social, and economic aspects. In order to overcome such barriers, innovative water-smart solutions are needed and a robust roadmap for the transition has to be established. In this introductive chapter, the key issues, including the roadmap, are presented. Future perspectives and research needs to roadmap the transition to circular economy are also outlined.

  • Inverse Flood Routing Using Simplified Flow Equations
    • Dariusz Gąsiorowski
    • Romuald Szymkiewicz
    2022 Full text WATER RESOURCES MANAGEMENT

    The paper considers the problem of inverse flood routing in reservoir operation strategy. The aim of the work is to investigate the possibility of determining the hydrograph at the upstream end based on the hydrograph required at the downstream end using simplified open channel flow models. To accomplish this, the linear kinematic wave equation, the diffusive wave equation and the linear Muskingum equation are considered. To achieve the hydrograph at the upstream end, an inverse solution of the afore mentioned equations with backward integration in the x direction is carried out. The numerical solution of the kinematic wave equation and the Muskingum equation bases on the finite difference scheme. It is shown that both these equations are able to provide satisfying results because of their exceptional properties related to numerical diffusion. In the paper, an alternative approach to solve the inverse routing using the diffusive wave model is also presented. To this end, it is described by a convolution which involves the instantaneous unit hydrograph (IUH) corresponding to the linear diffusive wave equation. Consequently, instead of a solution of partial or ordinary differential equations, the integral equation with Laguerre polynomials, used for the expansion of the upstream hydrograph, is solved. It was shown that the convolution approach is more reliable comparing to the inverse solution of the simplified models in the form of differential equations.

  • Inverse Modeling and Optimization of CSRR-based Microwave Sensors for Industrial Applications
    • Tanveer Haq Ul
    • Paulina Kozieł
    2022 IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES

    Design optimization of multivariable resonators is a challenging topic in the area of microwave sensors for industrial applications. This paper proposes a novel methodology for rapid re-design and parameter tuning of complementary split-ring resonators (CSRRs). Our approach involves inverse surrogate models established using pre-optimized resonator data as well as analytical correction techniques to enable rapid adjustment of geometry parameters and CSRR optimization over broad ranges of operating frequencies. The tuning process is arranged to precisely allocate the operating frequency while maximizing the quality factor of the circuit. The procedure is generic and characterized by an extremely low computational cost of up to two electromagnetic (EM) analyses of the circuit at hand (not counting the inverse model setup). The presented technique is demonstrated using a circular CSRR coupled to a microstrip transmission line (MTL), and optimized to operate between 5 GHz and 20 GHz. The design optimized for 15 GHz is fabricated and experimentally validated using a vector network analyzer. The sensor works in the transmission mode and senses the shift in resonance frequency determined by the properties of the material under test (MUT). Furthermore, an inverse regression model is developed that allows for directly finding the unknown permittivity of the MUT based on the measured resonant frequencies of the sensor. The obtained results corroborate the design utility of the proposed optimization method, as well as practical usefulness of the specific CSRR structure developed with the aid thereof.

  • Investigating an Optimal Computational Strategy to Retrofit Buildings with Implementing Viscous Dampers
    • Farzin Kazemi
    • Neda Asgarkhani
    • Ahmed Manguri
    • Robert Jankowski
    2022

    Civil engineering structures may seriously suffer from different damage states re-‎sult of earthquakes. Nowadays, retrofitting the existing buildings is a serious ‎need among designers. Two important factors of required performance level and ‎cost of retrofitting play a crucial role in the retrofitting approach. In this study, a ‎new optimal computational strategy to retrofit structures by implementing linear ‎Viscous Dampers (VDs) is investigated to achieve a higher performance level ‎with lower implementation cost. Regarding this goal, a Tcl programming code ‎was developed with the capability of considering damaged structure due to earth-‎quake-induced structural pounding. The code allows us to improve structural ‎models to take into account the real condition of buildings using both MATLAB ‎and Opensees software simultaneously. To present the capability of this strategy, ‎the 3-, and 6-story colliding Steel Moment-Resisting Frames (SMRFs) were se-‎lected. Incremental Dynamic Analysis (IDA) was performed based on the inter-‎story drift ratio of floor levels as engineering demand parameter, and Sa(T1) as in-‎tensity measure. Interstory median IDAs of floor levels of colliding SMRFs were ‎plotted to find out the floor level prone to damage and to retrofit only this floor ‎level instead of all stories. The results show that implementing only two linear ‎VDs with a cost of two units can achieve a higher life safety performance level in ‎the case of 3-, and 6-story SMRFs. Moreover, the proposed computational strat-‎egy can be used for any structure (with and without pounding conditions), and in ‎all performance levels prescribed in FEMA 356 code.‎

  • Investigating Noise Interference on Speech Towards Applying the Lombard Effect Automatically
    • Grazina Korvel
    • Krzysztof Kąkol
    • Povilas Treigys
    • Bożena Kostek
    2022 Full text

    The aim of this study is two-fold. First, we perform a series of experiments to examine the interference of different noises on speech processing. For that purpose, we concentrate on the Lombard effect, an involuntary tendency to raise speech level in the presence of background noise. Then, we apply this knowledge to detecting speech with the Lombard effect. This is for preparing a dataset for training a machine learning-based system for automatic speech conversion, mimicking a human way to make speech more intelligible in the presence of noise, i.e., to create Lombard speech. Several spectral descriptors are analyzed in the context of Lombard speech and various types of noise. In conclusion, pub-like and babble noises are most similar when comparing Spectral Entropy, Spectral RollOff, and Spectral Brightness. The larger values of these spectral descriptors, the more the speech-in-noise signal is degraded. To quantify the effect of noise on speech, containing the Lombard effect, an average formant track error is calculated as an objective image quality metric. For image quality assessment Structural SIMilarity (SSIM) index is employed.

  • Investigating the Impact of Weather Conditions and Time of Day on Traffic Flow Characteristics
    • Aleksandra Romanowska
    • Marcin Budzyński
    2022 Full text Weather Climate and Society

    Adverse weather such as rain, snow, and fog may significantly reduce visibility or change adhesion properties and, as a consequence, affect drivers’ sense of safety, driving comfort, and their reaction to a changing driving environment (i.e., lower speed and increased headways). The changed behavior of individual drivers affects both traffic flow characteristics, that is, average speed and headways, and parameters related to highway performance such as free-flow speed and capacity. Thus, understanding the impact may be important in the context of predicting and assessing traffic conditions on planned or existing road facilities. The paper discusses the effects of adverse weather conditions and time of day on traffic flow characteristics and the parameters related to highway performance. Using real traffic and weather data from a Polish expressway, the paper aims to identify factors related to weather and time of day that significantly influence traffic flow parameters and traffic conditions and to analyze and quantify this impact. The results of the study may help to develop coefficients of weather-related adjustment factors that will make it possible to estimate, for example, average speed of vehicles in the nighttime or in conditions of rain or limited visibility. The results of the study may contribute to a new Polish method for capacity estimation and traffic conditions assessment for uninterrupted traffic facilities.

  • Investigation of ecological parameters of a gas turbine combustion chamber with steam injection for the floating production, storage, and offloading vessel
    • Serhiy Serbin
    • Kateryna Burunsuz
    • Marek Dzida
    • Jerzy Kowalski
    • Daifen Chen
    2022 International Journal of Energy and Environmental Engineering

    The article is dedicated to the investigation of the possibility of using the contact type gas turbine cycle with steam injection into the combustion chamber for the floating production, storage, and offloading vessel in order to increase the specific power and efficiency and reduce emissions of toxic components. A new approach is proposed, associated with the use of the two-stage injection of superheated steam into a gas turbine combustion chamber operating on associated gas. In this case, ecological steam is injected to the primary zone of the chamber to reduce emissions of nitrogen oxides, and power steam is injected to the dilution zone of the chamber in order to increase the power of the installation. This approach can be used in gas turbine engines of various modifications and manufacturers. The thermodynamic parameters of the thermal scheme of a gas–steam turbine operating on associated gas have been determined. Three-dimensional calculations of ecological parameters of a combustion chamber have been carried out, making it possible to determine the rational ratio of the ecological and power steam flow rates to minimize emissions of nitrogen oxides. The results obtained can be used for the modernization of existing and refinement of new samples of environmentally friendly fuel-burning devices.

  • Investigation of Liquid–Gas Flow in a Horizontal Pipeline Using Gamma-Ray Technique and Modified Cross-Correlation
    • Robert Hanus
    • Marcin Zych
    • Anna Golijanek-Jędrzejczyk
    2022 Full text ENERGIES

    This article presents the application of the radioisotope absorption method in the study of two-phase water–air flow in a horizontal pipe. The measurement principle and the test stand are briefly described. The main part of the article presents the signal analysis methods applied to data obtained from scintillation detectors. Because these signals are mostly stochastic waveforms, they were analyzed statistically using the cross-correlation function (CCF), and methods that are a combination of CCF and differential methods: CCF/ASDF and CCF/AMDF, where ASDF is the average square difference function, and AMDF is the average magnitude difference function. Examples of the results of gas phase velocity measurement for four types of flow are presented. It was found that the CCF/ASDF and CCF/AMDF methods allow more accurate results of measurements of the dispersed phase to be obtained than the CCF method.

  • Investigation of Performance and Configuration of a Selected IoT System—Middleware Deployment Benchmarking and Recommendations
    • Robert Kałaska
    • Paweł Czarnul
    2022 Full text Applied Sciences-Basel

    Nowadays Internet of Things is gaining more and more focus all over the world. As a concept it gives many opportunities for applications for society and it is expected that the number of software services deployed in this area will still grow fast. Especially important in this context are properties connected with deployment such as portability, scalability and balance between software requirements and hardware capabilities. In this article, we present results of practical tests with multiple clients representing sensors sending notifications to an IoT middleware—DeviceHive. Firstly, we investigate performance using two deployment configurations—containerized and bare-metal showing small overhead of the former under different loads by various numbers of IoT clients. We present scaling of the middleware on the server side using various numbers of cores as well as HyperThreading for all aforementioned configurations. Furthermore, we also investigated how containarization affects performance when the system is scaled with various numbers of nodes each using a predefined number of cores, considering memory usage of various configurations. The latter could be found useful when assigning cores to Docker nodes in cloud environments.

  • INVESTIGATION OF THE CHARACTERISTICS OF A LOWEMISSION GAS TURBINE COMBUSTION CHAMBER OPERATING ON A MIXTURE OF NATURAL GAS AND HYDROGEN
    • Serhiy Serbin
    • Kateryna Burunsuz
    • Daifen Chen
    • Jerzy Kowalski
    2022 Full text Polish Maritime Research

    T his article is devoted to the investigation of the characteristics of a low-emission gas turbine combustion chamber, which can be used in Floating Production, Storage and Offloading (FPSO) vessels and operates on a mixture of natural gas and hydrogen. A new approach is proposed for modelling the processes of burning out a mixture of natural gas with hydrogen under preliminary mixing conditions in gaseous fuel with an oxidizer in the channels of radial-axial swirlers of flame tubes. The proposed kinetic hydrocarbon combustion scheme is used in three-dimensional calculations for a cannular combustion chamber of a 25 MW gas turbine engine for two combustion models: the Finite-Rate/EddyDissipation and the Eddy Dissipation Concept. It was found that, for the investigated combustion chamber, the range of stable operations, without the formation of a flashback zone in the channels of radial-axial swirlers, is determined by the hydrogen content in the mixture, which is less than 25-30% (by volume). For the operating modes of the chamber without the formation of a flashback zone inside the swirler channels, the emissions of nitrogen oxide NO and carbon monoxide CO do not exceed the values corresponding to modern environmental requirements for emissions of toxic components by gas turbine engines.

  • Investigation of the Effect of the Rocket's Suborbital Flight on Biofilm, Enzymes and Biosynthesis on Autonomous, Modular and Scalable Platforms For Conducting Experiments of an Astrobiotechnological Nature
    • Bartosz Rybacki
    • Marcin Jasiukowicz
    • Bartosz Rybak
    • Julia Godlewska
    • Beata Krawczyk
    2022 Full text

    With new incentives for human space exploration, biotechnological experiments in orbit became imperative. Answering this need, we build an autonomous, modular, and scalable platform that enables those experiments on rockets. We called it AMBER. The aim of the payload of the R6 suborbital rocket is to perform an experiment to study the influence of rocket flights on biofilm, molecular biology enzymes and biosynthesis using our platform. For this purpose, we use the interdisciplinary character of our team to ensure full integrity, reliability, and operational efficiency. The experiment carried out during the Spaceport America Cup competition constitutes the first stage of our team’s three-stage programme of astrobiotechnological experiments, which scientific value was confirmed by a letter of recommendation from the scientist working for NASA Ames Research Center. Two 96 well plates, as operational sectors, were subjected to the same effects of G-force, rocket launch velocity, temperature, pressure and vibration profile. In the experiment, we used 3D printed elements, Peltier cells, GPS, and sensors measuring vibrations, temperature, pressure and G-force. These instruments enable exact characterisation conditions experienced by biological samples.

  • Investigation of the Effect of The Temperature and Magnetization Pattern on Flux Density, Instantaneous Torque, Unbalanced Magnetic Forces of a Surface Inset PMM
    • Ahmed Abbas
    • Atif Iqbal
    • A. Hosseinpour
    • Mohammad Shahabuddin
    • Ersan Kabalci
    2022

    Electrical machines utilized in domestic applications such as ceiling fans should have low losses and cost. Permanent magnets are used instead of rotor excitation to reduce losses. Therefore, not only the losses of the rotor winding are eliminated, but also the efficiency of the machine is increased. A surface inset consequent pole (SICP) machine has also been used to reduce costs. Because less magnets are utilized in this structure. The main problem is the affecting the residual flux density from temperature. In this paper, the SICP is analyzed by two-dimensional method, then magnetic flux density, Back-EMF, instantaneous torque and unbalanced magnetic forces are calculated. In this research, either the effect of temperature changes on the mentioned cases has been investigated, or two types of magnetization patterns include radial and parallel have been considered.