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  • Singlet oxygen in the removal of organic pollutants: An updated review on the degradation pathways based on mass spectrometry and DFT calculations
    • Manoj P Rayaroth
    • Usha K. Aravind
    • Grzegorz Boczkaj
    • Charuvila T. Aravindakumar
    2023 CHEMOSPHERE

    The degradation of pollutants by a non-radical pathway involving singlet oxygen (1O2) is highly relevant in advanced oxidation processes. Photosensitizers, modified photocatalysts, and activated persulfates can generate highly selective 1O2 in the medium. The selective reaction of 1O2 with organic pollutants results in the evolution of different intermediate products. While these products can be identified using mass spectrometry (MS) techniques, predicting a proper degradation mechanism in a 1O2-based process is still challenging. Earlier studies utilized MS techniques in the identification of intermediate products and the mechanism was proposed with the support of theoretical calculations. Although some reviews have been reported on the generation of 1O2 and its environmental applications, a proper review of the degradation mechanism by 1O2 is not yet available. Hence, we reviewed the possible degradation pathways of organic contaminants in 1O2-mediated oxidation with the support of density functional theory (DFT). The Fukui function (FF, f−, f+, and f0), HOMO–LUMO energies, and Gibbs free energies obtained using DFT were used to identify the active site in the molecule and the degradation mechanism, respectively. Electrophilic addition, outer sphere type single electron transfer (SET), and addition to the hetero atoms are the key mechanisms involved in the degradation of organic contaminants by 1O2. Since environmental matrices contain several contaminants, it is difficult to experiment with all contaminants to identify their intermediate products. Therefore, the DFT studies are useful for predicting the intermediate compounds during the oxidative removal of the contaminants, especially for complex composition wastewater.

  • Skalowalne modele fizyczne wybranych typów siłowni wiatrowych w technologii hardware-in-the-loop
    • Robert Rink
    2023 Pełny tekst

    Celem niniejszej rozprawy jest opracowanie adekwatnego programowalnego modelu fizycznego siłowni wiatrowej wykorzystującego urządzenia elektryczne oraz model przetwarzania energii kinetycznej wiatru na energię mechaniczną ruchu obrotowego wirnika generatora. Zaproponowany przez autora model sterowany jest przez regulator prędkości, bazujący jedynie na pomiarach prędkości obrotowej oraz momentu elektromagnetycznego. Monografia stanowi syntezę aktualnego stanu wiedzy dotyczącej modeli matematycznych oraz sposobów modelowania turbin wiatrowych. Studia i analiza obecnego stanu wiedzy w zakresie przedmiotu pracy objęły stosowane sposoby realizacji modeli fizycznych oraz symulacyjnych siłowni wiatrowej i jej poszczególnych elementów oraz analizę publikowanych wyników przeprowadzonych prac badawczych z wykorzystaniem modeli fizycznych. Przeprowadzona analiza pozwoliła na zidentyfikowanie wad i ograniczeń dotychczasowych realizacji. W konsekwencji, zaproponowano autorskie rozwiązanie skalowalnego modelu fizycznego siłowni wiatrowej z maszyną dwustronnie zasilaną pracującą jako generator bazując na rozwiązaniach stosowanych w technice hardware-in-the-loop. Rozwiązanie łączy uniwersalność modeli cyfrowych z wykorzystaniem urządzeń elektrycznych. W skład opracowanej cyfrowej części modelu wchodzą wszystkie elementy występujące w rzeczywistej siłowni wiatrowej. Część cyfrowa modelu zrealizowana została w środowisku czasu rzeczywistego Simulink Real-Time. Strukturę modelu opracowano w taki sposób, aby możliwa była stabilna praca modelu w sprzężeniu z przekształtnikami i zespołem maszynowym. W szczególności zaproponowano autorską metodę dostosowania stałej bezwładności maszyny dwustronnie zasilanej skalowalnego modelu fizycznego siłowni wiatrowej z modelowaniem inercji w torze sterowania momentem wraz z regulatorem prędkości. Istotnym elementem pracy jest opracowanie sposobu walidacji skalowalnego fizycznego modelu siłowni wiatrowej z maszyną dwustronnie zasilaną. Przeprowadzono badania porównawcze fizycznego modelu siłowni wiatrowej oraz referencyjnej farmy wiatrowej. Uzyskane w rozprawie wyniki badań symulacyjnych oraz testów laboratoryjnych wykazały, że zaproponowany model fizyczny siłowni wiatrowej pozwala na miarodajną oraz efektywną emulację wybranych typów rzeczywistych siłowni wiatrowych.

  • "SKONTEKSTOWANE. zamieszkiwanie krajobrazów", dwa tryptyki malarskie, akryl/ podobrazie płócienne, materiał video
    • Agnieszka Kurkowska
    2023

    Poruszamy się w świecie przemieszanych znaczeń. Kierowani tradycją, doświadczeniem i intuicją przemierzamy przestrzenie odnosząc je do swojego domu. W każdy otaczający krajobraz podświadomie lub celowo wpisujemy siebie. Filtrujemy obraz, dźwięk i zapach włączając wartości niesione przez życie. Dom z marzeń, dom ze wspomnień, dom, do którego tęsknimy, nasz dom: wypełniają kadry i współtworzy historię odwiedzanych miejsc. Przedstawione obrazy to autorska próba przedstawienia sytuacji umieszczania domu w kaszubskim krajobrazie Pojezierza Wdzydzkiego. Plastyczna interpretacja wybranych miejsc łączy się z dokumentującymi fotografiami.

  • Skuteczność kluczowych technologii w określaniu stabilności i kompatybilności ropy naftowej
    • Dagmara Aptowicz
    • Aleksandra Małachowska
    • Katarzyna Kibort
    • Monika Rogowska
    • Jacek Gębicki
    2023 Pełny tekst Przemysł Chemiczny

    Przedstawiono porównanie metod pomiarowych dotyczących oznaczania stabilności i kompatybilności rop naftowych celem ułatwienia przerobu ropy naftowej i paliw ciężkich. Przeanalizowano doświadczenia innych naukowców w porównaniu z wynikami własnych badań eksperymentalnych. Zaobserwowano różną skuteczność stosowanych metod w odniesieniu do wybranych gatunków rop naftowych. Wytypowano P-value, S-value, metodę SARA oraz metody mikroskopowe jako najbardziej skuteczne, określając możliwości wykorzystania danego oznaczenia w praktyce, w zależności od celu badań i potrzeb odbiorcy. Ponadto w pracy wskazano istotne zalety i wady wymienionych metod, stanowiących użyteczne narzędzie do wyboru najbardziej właściwej metody oznaczania stabilności i kompatybilności dla danego gatunku ropy naftowej i paliw ciężkich.

  • Skutki zanieczyszczenia środowiska związane z generowaniem energii
    • Anna Dettlaff
    2023

    Na całym świecie (dane z 2020 roku) spalanie paliw kopalnych takich jak węgiel, ropa naftowa i gaz ziemny dostarczyło ok. 84% całej zużywanej energii pierwotnej. W przypadku Polski konwencjonalne źródła energii stanowiły ponad 93%. Gigantyczne zużycie konwencjonalnych paliw powoduje wielkie straty w środowisku, objawiające się m.in. skażeniem powietrza, które stanowi największe środowiskowe zagrożenie dla zdrowia ludzi na świecie i jest przyczyną milionów przedwczesnych zgonów i chorób. Szacuje się, że obciążenie chorobami powodowanymi przez skażenie powietrza jest porównywalne do innych globalnych zagrożeń dla zdrowia, w tym niezdrowej diety i palenia tytoniu. W tym rozdziale szczegółowo omówiono dwa zjawiska, smog i globalne ocieplenie, które stanowią środowiskowy, społeczny, ekonomiczny i zdrowotny koszt spalania paliw kopalnych.

  • Sliding bearings with sintered bronze bush lubricated by contaminated water with solid particles – Theoretical and experimental studies
    • Wojciech Litwin
    • Steffen Kropp
    2023 WEAR

    Sliding journal bearings lubricated with water coming directly from the environment are a solution used in shipbuilding, pumps and hydropower. However, the working fluid or surrounding water cannot always be filtered because of design limitations, which often causes the problem of premature wear of these sensitive bearings. The research conducted made it possible to assess the wear of sliding bearings lubricated with water containing solid particles of mineral origin. It has been proved that the geometry of the bearing and the relative size of the particles have a significant impact on the wear process of the tested sliding pair of sintered bronze and steel.

  • Soft skills among academics: Five theoretically informed lessons for current times
    • Joanna Szulc
    • Magdalena Toporek
    • Michał Tomczak
    • Małgorzata Gawrycka
    2023 Pełny tekst Horyzonty Polityki

    RESEARCH OBJECTIVE: The aim of this article is to provide a comprehensive examination of the role of soft skills among academics in the context of the evolving higher-education landscape. THE RESEARCH PROBLEM AND METHODS: We use a scoping review of existing literature to discuss the importance of soft skills in academia. Through critical analysis and synthesis, we identify patterns and gaps in current knowledge and develop five theoretically informed lessons to improve practice and theory. THE PROCESS OF ARGUMENTATION: A unique theoretical blending of five theories (resource-based, dynamic capabilities, cultural learning, implicit leadership, and human capital) forms the conceptual framework we used to arrive at our conclusions. RESEARCH RESULTS: Our first conclusion emphasizes that soft skills are essential for a competitive advantage in the performative culture of neoliberal academies. Second, we emphasize that updating soft skills is crucial in order to respond to the changing higher-education environment. Third, going beyond the universal view of academia as a sharply hierarchical industry, we demonstrate how building relationships with stakeholders is necessary for academic skill development. Our fourth lesson explores the implications of different evaluators’ perceptions of soft skills, highlighting the need for recognition of their value. The ultimate lesson highlights the need to invest in the skills of academics. CONCLUSIONS, INNOVATIONS, AND RECOMMENDATIONS: We consolidate existing theoretical approaches and overcome theoretical fragmentation to arrive at a comprehensive and theoretically grounded set of lessons for those interested in developing and utilizing soft skills among academics in the unique context of the ever-changing higher-education environment. We challenge the norms of neoliberal academia and call for the development of realistic policies and procedures that promote a respectful, collaborative, and sustainable higher-education environment.

  • Solar light driven degradation of textile dye contaminants for wastewater treatment – studies of novel polycationic selenide photocatalyst and process optimization by response surface methodology desirability factor
    • Arif Nawaz
    • Muhammad Atif
    • Adnan Khan
    • Mohsin Siddique
    • Nisar Ali
    • Falak Naz
    • Muhammad Bilal
    • Tak H. Kim
    • Malwina Momotko
    • Hameed Haq
    • Grzegorz Boczkaj
    2023 CHEMOSPHERE

    The unplanned anthropogenic activities and raced industrial revolution detrimentally causes serious threat to terrestrial and aquatic life. A high discharge of wastewater from industries using dyes affects living organisms and the environment. This paper presents studies on polycationic selenides (PCS) synthesized by hydrothermal methods for photocatalytic degradation of dyes. The synthesized PCS were confirmed by various characterization techniques such as FTIR, SEM, EDX, UV/Vis, and XRD. The FTIR spectra revealed characteristic band at 843, 548 cm−1, and 417 cm−1 due to the M − Se stretching and intrinsic stretching vibrations, respectively. The optical bandgap of polycationic selenide lies in the visible light region (2.36 eV). The SEM images showed that PCS has a spherical shape with an average crystallite size of 29.23 nm calculated from XRD data using Scherer's equation. The PCS has a point of zero charge (PZC) at pH 7. The efficiency of synthesized PCS photocatalyst was confirmed in terms of its activity towards Eosin (EY) and Crystal violet (CV) dyes mineralization. The photocatalytic degradation for EY and CV dyes at optimum conditions was 99.47% and 99.31% and followed second order reactions kinetics with 1.4314 and 0.551 rate constant, respectively. The polynomial quadratic model is the best-fitted response surface methodology (RSM) model having a maximum desirability factors value and significant terms, with R2 (0.9994) and adj R2 values (1.0).

  • Solubility of carbon dioxide in water: Some useful results for hydrate nucleation
    • Jesús Algaba
    • Iván M. Zerón
    • José Manuel Míguez
    • Joanna Grabowska
    • Samuel Blazquez
    • Eduardo Sanz
    • Carlos Vega
    • Felipe J. Blas
    2023 Pełny tekst JOURNAL OF CHEMICAL PHYSICS

    In this paper, the solubility of carbon dioxide (CO2) in water along the isobar of 400 bar is determined by computer simulations using the well-known TIP4P/Ice force field for water and the TraPPE model for CO2. In particular, the solubility of CO2 in water when in contact with the CO2 liquid phase and the solubility of CO2 in water when in contact with the hydrate have been determined. The solubility of CO2 in a liquid–liquid system decreases as the temperature increases. The solubility of CO2 in a hydrate–liquid system increases with temperature. The two curves intersect at a certain temperature that determines the dissociation temperature of the hydrate at 400 bar (T3). We compare the predictions with T3 obtained using the direct coexistence technique in a previous work. The results of both methods agree, and we suggest 290(2) K as the value of T3 for this system using the same cutoff distance for dispersive interactions. We also propose a novel and alternative route to evaluate the change in chemical potential for the formation of hydrates along the isobar. The new approach is based on the use of the solubility curve of CO2 when the aqueous solution is in contact with the hydrate phase. It considers rigorously the non-ideality of the aqueous solution of CO2, providing reliable values for the driving force for nucleation of hydrates in good agreement with other thermodynamic routes used. It is shown that the driving force for hydrate nucleation at 400 bar is larger for the methane hydrate than for the carbon dioxide hydrate when compared at the same supercooling. We have also analyzed and discussed the effect of the cutoff distance of dispersive interactions and the occupancy of CO2 on the driving force for nucleation of the hydrate.

  • Solvent influence on the crystal structures of new cadmium tri-tert -butoxysilanethiolate complexes with 1,4-bis(3-aminopropyl)piperazine: luminescence and antifungal activity
    • Daria Kowalkowska-Zedler
    • Piotr Bruździak
    • Zbigniew Hnatejko
    • Renata Łyszczek
    • Anna Brillowska-Dąbrowska
    • Łukasz Ponikiewski
    • Bartosz Cieśla
    • Agnieszka Pladzyk
    2023 Pełny tekst Acta Crystallographica Section C-Structural Chemistry

    Monocrystals of dinuclear 1,4-bis(3-aminopropyl)piperazine-�4N1,N10:N4,N40-bis[bis(tri-tert-butoxysilanethiolato-�S)cadmium(II)], [Cd2(C12H27O3SSi)4(C10-H24N4)] or [Cd2{SSi(OtBu)3}4(�-BAPP)], 1, and polynuclear catena-poly[[bis- (tri-tert-butoxysilanethiolato-�S)cadmium(II)]-�-1,4-bis(3-aminopropyl)piperazine-�2N10:N40], [Cd(C12H27O3SSi)2(C10H24N4)]n or [Cd{SSi(OtBu)3}2(�-BAPP)]n, 2, with 1,4-bis(3-aminopropyl)piperazine (BAPP) and tri-tert-butoxysilane-thiolate ligands, were obtained from the same ratio of reactants, but with different solvents used for the crystallization processes. The structures and properties of both complexes were characterized using elemental analysis, X-ray diffraction and FT–IR, 1H NMR and luminescence spectroscopy. Applied density functional theory (DFT) computational methods and noncovalent interaction (NCI) analysis were used for geometry optimization and visualiza- tion of the interactions between the metallic centres and their surroundings. The X-ray analysis revealed four-coordinate CdII centres bound to two S atoms of the silanethiolate groups and two N atoms of the BAPP ligand; however, it chelates to tertiary and primary N atoms in 1, whilst in 2 it does not chelate and bonds only to RNH2. The photoluminescence properties of complexes 1 and 2 result from free-ligand emission and differ significantly from each other with respect to emission intensity. Additionally, antifungal activity was investigated against 18 isolates of fungi. Compound 1 strongly inhibited the growth of three dermatophytes: Epidermophyton floccosum, Microsporum canis and Trichophyton rubrum.

  • Sources of contamination in sediments of retention tanks and the influence of precipitation type on the size of pollution load
    • Karolina Matej-Łukowicz
    • Ewa Wojciechowska
    • Tomasz Kolerski
    • Nicole Nawrot
    • Karol Kuliński
    • Aleksandra Winogradow
    2023 Pełny tekst Scientific Reports

    Densification of cities and urban population contributes to increased runoff and suspended solids and alteration of the urban water cycle. Nowadays, Blue-Green Infrastructure is promoted to increase a city’s resilience to floods; however, stormwater drainage systems, supported with retention tanks are still important in protecting urban areas against floods. Sediment accumulation in stormwater infrastructure relates to an issue of pollutants such as heavy metals, nutrients etc. Research on the origin of the pollutants associated with the suspension and ultimately sediment accumulated in sewage can bring new insights about processes in urban catchment areas. This is the first study, which is focused on the analysis of stable carbon and nitrogen isotopes in bottom sediments collected from municipal retention tanks to verify the origin of the deposited pollutants immediately after pluvial floods. The research was additionally extended with water quality analyzes immediately after three types of weather: a dry period, typical precipitation (< 30 mm) and torrential rainfalls (2 events with daily precipitation over 30 mm which caused pluvial flooding of the city area). Analyses of sediments indicated that the main source of carbon and nitrogen in the bottom of the retention tanks had been brought with stormwater runoff from the city area. Organic nitrogen fertilizers appeared to be the main source of nitrogen, while the sources of organic carbon were mixed: C3 land plants, wood, and oil. Additionally, it was found that torrential rainfall caused a 23-fold increase of N-NO3 concentration, a sevenfold increase of P-PO4 concentration, and an over fivefold increase of concentration of organic matter, in comparison to typical precipitation.

  • Space Vector Pulsewidth Modulation Strategy for Multilevel Cascaded H-Bridge Inverter With DC-Link Voltage Balancing Ability
    • Arkadiusz Lewicki
    • Charles Odeh
    • Marcin Morawiec
    2023 Pełny tekst IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS

    Space vector pulsewidth modulation (SVPWM) algorithms for cascaded H-bridge multilevel (CHB ML) inverter usually provide the possibility of using several combinations of active voltage vectors to generate the same output voltage vector. For preselected H-bridges, some of them may generate output voltages opposite to the assumed direction. This results in the change of the dc-link voltages of these H-bridges in the opposite direction to the assumed direction in the ordering algorithm. Consequently, these algorithms are characterized by undue constraints and narrow possibilities of dc-link voltage balancing. In the proposed control algorithm, CHB ML inverter is treated as groups of successively activated three-level inverters; depending on the length of the reference voltage vector. These three-level inverters consist of three H-bridges selected from each phase. The proposed extended selection method enables firm-grip control of the dc-link voltages. For a given direction of phase currents, the possibility of using H-bridges with lowest and highest dc-link voltages is simultaneously analyzed. Additionally, each of the three-level inverters is controlled by one of three proposed alternative modulation methods for which both the attainable output voltage vectors and unbalanced dc-link voltages are predicted. Simulation and experimental results confirm the correctness of the algorithm execution.

  • Spatial aspects of urban air quality management: Estimating the impact of micro-scale urban form on pollution dispersion
    • Joanna Badach
    • Wojciech Wojnowski
    • Jacek Gębicki
    2023 Pełny tekst COMPUTERS ENVIRONMENT AND URBAN SYSTEMS

    Urban planning and design solutions affect urban ventilation conditions, thus mitigating the effects of atmospheric pollution. However, these findings are not being implemented in the planning practice to a sufficient extent, partly due to the lack of specific guidelines. Moreover, many urban air quality monitoring (AQM) sites have low represnentativeness and thus do not provide comprehensive data for effective urban air pollution control with respect to the urban spatial policy. An integrated assessment method based on modelling, simulation, and geospatial data processing tools was used to investigate the impact of micro-scale urban form on the local ventilation conditions and pollution dispersion. The proposed approach combined computational fluid dynamics (CFD) and geographic information system (GIS) tools, and particularly the newly developed Residence Time Index (RTI) - a single CFD-derived parameter quantifying the capabilities of the micro-scale built environment to retain PM10 pollution. Urban segments around monitoring sites in three Polish cities (Gda´nsk, Warsaw, and Pozna´n), characterised by relatively low density and varied urban form typologies, were investigated. The results indicate that in these conditions the following features of the urban form have the strongest correlation with the RTI: plan area density (λP), gross floor area ratio (λGFA), and occlusivity (Oc), making them useful indicators for urban air quality management. On the other hand, PM10 data from the AQM sites are rather poorly linked with urban form indicators, which suggests that in complex urban scenarios a higher spatial resolution of air quality data is required for shaping the spatial policy. The implications from this analysis are useful for the urban planning practice. The developed approach may be also a valuable decision support tool for the assessment of the spatial representativeness of AQM sites.

  • Spatial Distribution of Eucalyptus Plantation and its Impact on the Depletion of Groundwater Resources of Tehsil Swat Ranizai, District Malakand
    • Muhammad Jamal Nasir
    • Waqar Akhtar
    • Vipin Kumar Oad
    2023 Pełny tekst Arabian Journal of Geosciences

    Native to the continent of Australia, eucalyptus is a tall, evergreen tree belonging to the Myrtaceae family. Malakand district has the largest eucalyptus plantation in the province, covering an area of 22,071.29 ha. The present study aims to evaluate its impact on the groundwater table (GWT) in three selected union councils (UCs) of the study area, i.e., Agra, Totakan, and Kot. Both primary and secondary data support the study. The data regarding eucalyptus plantations were collected from the Malakand Forest Division. GPS was used to mark the wells’ locations. The current GWT was measured in the field. Rainfall data of the study area and surrounding was acquired from the Regional Meteorological Office Peshawar. A questionnaire survey was conducted to determine the respondents’ opinion of the impact of eucalyptus plantations. The study reveals that though the GWT dropped from 2000 to 2019 in the study area, the decline is more significant in the vicinity of the plantation. The GWT near the plantation in the Agra UC dropped from 39 to 60 ft., 25 to 45 ft. in Totakan, and from 20 to 60 ft. in Kot UC during the study period. The study reveals no significant impact of rainfall on GWT depletion. The respondents appear to be aware of the negative effects of eucalyptus plantations on the GWT, agriculture, and biodiversity. The study concludes that, while considering community interests, there is a critical need for research to investigate and quantify the site-specific effects of eucalyptus on the ecosystem. The study concludes that, while considering community interests, there is a critical need for research to investigate and quantify the site-specific effects of eucalyptus on the ecosystem. The Eucalyptus will be able to continue fending off the rising deforestation and demand for fuel until then.

  • Spatial Visualization Based on Geodata Fusion Using an Autonomous Unmanned Vessel
    • Marta Wlodarczyk-Sielicka
    • Dawid Połap
    • Katarzyna Prokop
    • Karolina Połap
    • Andrzej Stateczny
    2023 Pełny tekst Remote Sensing

    The visualization of riverbeds and surface facilities on the banks is crucial for systems that analyze conditions, safety, and changes in this environment. Hence, in this paper, we propose collecting, and processing data from a variety of sensors—sonar, LiDAR, multibeam echosounder (MBES), and camera—to create a visualization for further analysis. For this purpose, we took measurements from sensors installed on an autonomous, unmanned hydrographic vessel, and then proposed a data fusion mechanism, to create a visualization using modules under and above the water. A fusion contains key-point analysis on classic images and sonars, augmentation/reduction of point clouds, fitting data and mesh creation. Then, we also propose an analysis module that can be used to compare and extract information from created visualizations. The analysis module is based on artificial intelligence tools for the classification tasks, which helps in further comparison to archival data. Such a model was tested using various techniques to achieve the fastest and most accurate visualizations possible in simulation and real case studies.

  • Spatio-Temporal Validation of GNSS-Derived Global Ionosphere Maps Using 16 Years of Jason Satellites Observations
    • Mateusz Poniatowski
    • Grzegorz Nykiel
    • Claudia Borries
    • Jędrzej Szmytkowski
    2023 Pełny tekst Remote Sensing

    Existing ionospheric models perform very well in mapping the calm state of the ionosphere. However, the problem is accurately determining the total electron content (TEC) for disturbed days. Knowledge of the exact electron density is essential for single−frequency receivers, which cannot eliminate the ionospheric delay. This study aims to investigate temporal and spatial variability in the distribution of TEC based on differences between maps of individual Ionospheric Associated Analysis Centers (IAACs) of the International GNSS Service (IGS) and aligned altimetry−TEC from 2005–2021. Based on the temporal distribution, we have observed a significant effect of solar activity on the mean and standard deviation behavior of the differences between global ionospheric maps (GIMs) and Jason−derived TEC. We determined the biases for the entire calculation period, through which it can be concluded that the upcg-Jason and igsg-Jason differences have the lowest standard deviation (±1.81 TECU). In addition, the temporal analysis made it possible to detect annual, semi−annual, and 117-day oscillations occurring in the Jason−TEC data, as well as 121-day oscillations in the GIMs. It also allowed us to analyze the potential sources of these cyclicities, solar and geomagnetic activity, in the case of the annual and semi−annual periodicities. When considering spatial variations, we have observed that the most significant average differences are in the intertropical areas. In contrast, the smallest differences were recorded in the southern hemisphere, below the Tropic of Capricorn (23.5°S). However, the slightest variations were noted for the northern hemisphere above the Tropic of Cancer (23.5°N). Our research presented in this paper allows a better understanding of how different methods of GNSS TEC approximation affect the model’s accuracy.

  • Spawalność ferrytyczno-austenitycznej stali odpornej na korozję typu dupleks 2205 w warunkach podwodnych
    • Karolina Prokop-Strzelczyńska
    2023 Pełny tekst

    Praca dotyczy problemów spawalności stali odpornej na korozję typu dupleks w warunkach spawania mokrego elektrodami otulonymi i lokalną komorą suchą. Całość rozprawy składa się z dwóch części. Część pierwsza to przegląd literatury, w którym omówiono główne problemy wynikające z przeniesienia procesu spawania pod wodę oraz sposoby minimalizowania negatywnego wpływu środowiska. Część druga jest częścią doświadczalną, zawiera tezę i cele rozprawy, a także charakterystykę badanych materiałów, opis metodyki badań oraz wyniki wraz z ich omówieniem. Do badań zastosowano stal dupleks 1.4462, którą poddano badaniom spawalności metodą Tekken oraz zmiennej sztywności w warunkach podwodnych jak i na powietrzu. Próby wykonano w oparciu o dwie metody, tj. elektrodami otulonymi (MMA), metodą Lokalnej Komory Suchej w warunkach podwodnych i na powietrzu. Wykonano pomiary zawartości wodoru dyfundującego w stopiwie oraz badania struktur każdej próbki. Złącza poddano badaniom wizualnym i penetracyjnym oraz badaniom metalograficznym makro- i mikroskopowym. Próbki o zmieniającej się sztywności poddano badaniom fraktograficznym przełomów. Wykazano, że spawalność stali dupleks w warunkach podwodnych elektrodami otulonymi jest ograniczona z uwagi na utrudnioną spawalność technologiczną. Stwierdzono również, że zastosowanie metody LKS skutecznie ułatwia uzyskanie złączy, spełniających odpowiednie wymagania norm przedmiotowych.

  • Special Issue on “Advanced Liquid Waste and Gas Waste Treatment Processes”
    • Piotr Rybarczyk
    2023 Pełny tekst Processes

    The editorial contains a short review of the content of the Special Issue on waste gas and liquid streams treatment strategies.

  • Spectrum Sensing Based on Hybrid Spectrum Handoff in Cognitive Radio Networks
    • Lakshminarayanan Vaduganathan
    • Shubhangi Neware
    • Przemysław Falkowski-Gilski
    • Parameshachari Bidare Divakarachari
    2023 Pełny tekst ENTROPY

    The rapid advancement of wireless communication combined with insufficient spectrum exploitation opens the door for the expansion of novel wireless services. Cognitive radio network (CRN) technology makes it possible to periodically access the open spectrum bands, which in turn improves the effectiveness of CRNs. Spectrum sensing (SS), which allows unauthorized users to locate open spectrum bands, plays a fundamental part in CRNs. A precise approximation of the power spectrum is essential to accomplish this. On the assumption that each SU’s parameter vector contains some globally and partially shared parameters, spectrum sensing is viewed as a parameter estimation issue. Distributed and cooperative spectrum sensing (CSS) is a key component of this concept. This work introduces a new component-specific cooperative spectrum sensing model (CSCSSM) in CRNs considering the amplitude and phase components of the input signal including Component Specific Adaptive Estimation (CSAE) for mean squared deviation (MSD) formulation. The proposed concept ensures minimum information loss compared to the traditional methods that consider error calculation among the direct signal vectors. The experimental results and performance analysis prove the robustness and efficiency of the proposed work over the traditional methods.

  • Speed estimation of a car at impact with a W-beam guardrail using numerical simulations and machine learning
    • Dawid Bruski
    • Łukasz Pachocki
    • Adam Ścięgaj
    • Wojciech Witkowski
    2023 Pełny tekst ADVANCES IN ENGINEERING SOFTWARE

    This paper aimed at developing a new method of estimating the impact speed of a passenger car at the moment of a crash into a W-beam road safety barrier. The determination of such a speed based on the accident outcomes is demanding, because often there is no access to full accident data. However, accurate determination of the impact speed is one of the key elements in the reconstruction of road accidents. A machine learning algorithm was used to create the speed estimation model. The model was based on regression trees algorithms, with base regressors forming a final voting ensemble. The model was trained, validated, and tested using a database containing results from full-scale crash tests and numerical simulations. The developed machine learning model had a mean absolute error of 6.76 km/h with a standard deviation of 1.01 km/h on the cross-validation set, and a coefficient of determination, R2, of 0.85. This model was used to estimate the impact speed of the vehicle in three real road accidents with the W-beam barrier, and then the determined speeds were used in additional simulations to verify the results. A good quantitative and qualitative agreement between the simulation and accident outcomes was achieved, and this confirmed that the proposed method and the developed ML models combined with numerical simulations and full-scale crash tests can be effective tools for estimating the speed of the vehicle at impact with a roadside barrier.

  • Spike patterns and chaos in a map-based neuron model
    • Piotr Bartłomiejczyk
    • Frank Llovera Trujillo
    • Justyna Signerska-Rynkowska
    2023 Pełny tekst International Journal of Applied Mathematics and Computer Science

    The work studies the well-known map-based model of neuronal dynamics introduced in 2007 by Courbage, Nekorkin and Vdovin, important due to various medical applications. We also review and extend some of the existing results concerning β-transformations and (expanding) Lorenz mappings. Then we apply them for deducing important properties of spike-trains generated by the CNV model and explain their implications for neuron behaviour. In particular, using recent theorems of rotation theory for Lorenz-like maps, we provide a classification of periodic spiking patterns in this model.

  • Spin-Resolved Band Structure of Hoffman Clathrate [Fe(pz)2Pt(CN)4] as an Essential Tool to Predict Optical Spectra of Metal–Organic Frameworks
    • Adrian Olejnik
    • Wioletta Kopeć
    • Dominik Maskowicz
    • Mirosław Sawczak
    2023 ACS Applied Materials & Interfaces

    Paramount spin-crossover properties of the 3D-Hoffman metalorganic framework (MOF) [Fe(pz)2Pt(CN)4] are generally described on the basis of the ligand field theory, which provides adequate insight into theoretical and simulation analysis of spintronic complexes. However, the ligand field approximation does not take into account the 3D periodicity of the actual complex lattice and surface effects and therefore cannot predict a full-scale periodic structure without utilizing more advanced methods. Therefore, in this paper, the electronic properties of the exemplar MOF were analyzed from the band structure perspective in low-spin (LS) and high-spin (HS) states. The density-of-states spectra determined for both spin-up and spin-down electrons of Fe d6 orbitals indicate spin–orbital splitting and delocalization for HS due to spin polarization in the iron atom ligand field. Presence of the surface states in the real crystal causes a red shift of the metal–metal charge transfer (MMCT) and metal–ligand charge transfer (MLCT) peaks for both HS and LS states. The addition of residual water molecules and disorder among the pyrazine rings reveal additional influences on the positions of the pyrazine band and, therefore, on the absorption spectra of the crystal. The results show a magnification of the peak correlated with the MLCT in the HS state and a significant red shift of the LS characteristic absorption band. The presented approach involving band structure analysis delivers a more complete image of the electronic properties of the [Fe(pz)2Pt(CN)4] crystalline network and can be a landmark for insightful studies of other MOFs

  • Splice variants of mitofusin 2 shape the endoplasmic reticulum and tether it to mitochondria
    • Déborah Naón
    • María Isabel Hernández-Alvarez
    • Satoko Shinjo
    • Miłosz Wieczór
    • Saska Ivanova
    • Olga Martins de Brito
    • Albert Quintana
    • Juan Hidalgo
    • Manuel Palacín
    • Pilar Aparicio
    • Juan Castellanos
    • Luis Lores
    • David Sebastián
    • Sonia Fernández-Veledo
    • Joan Vendrell
    • Jorge Joven
    • Modesto Orozco
    • Antonio Zorzano
    • Luca Scorrano
    2023 SCIENCE

    In eukaryotic cells, different organelles interact at membrane contact sites stabilized by tethers. Mitochondrial mitofusin 2 (MFN2) acts as a membrane tether that interacts with an unknown partner on the endoplasmic reticulum (ER). In this work, we identified the MFN2 splice variant ERMIT2 as the ER tethering partner of MFN2. Splicing of MFN2 produced ERMIT2 and ERMIN2, two ER-specific variants. ERMIN2 regulated ER morphology, whereas ERMIT2 localized at the ER-mitochondria interface and interacted with mitochondrial mitofusins to tether ER and mitochondria. This tethering allowed efficient mitochondrial calcium ion uptake and phospholipid transfer. Expression of ERMIT2 ameliorated the ER stress, inflammation, and fibrosis typical of liver-specific Mfn2 knockout mice. Thus, ER-specific MFN2 variants display entirely extramitochondrial MFN2 functions involved in interorganellar tethering and liver metabolic activities.

  • Społeczny wymiar adaptacji do zmian klimatu w środowisku miejskim na przykładzie Gdańska
    • Małgorzata Dymnicka
    • Paweł Starosta
    • Jarosław Załęcki
    2023 Pełny tekst PRZEGLĄD SOCJOLOGICZNY

    Kwestie zmian klimatycznych przestały być przedmiotem zainteresowania jedynie wąskich grup specjalistów, a stały się problemem społecznym angażującym szerszą opinię publiczną. Wobec wzrastającego znaczenia problemów środowiskowych w społeczeństwach, głównie na przełomie XX i XXI wieku, władze centralne we współpracy z samorządami miejskimi zaczęły podejmować działania na rzecz wsparcia tzw. środowiskowej (zielonej) polityki. Artykuł poświęcony jest charakterystyce stanu świadomości ekologicznej mieszkańców Gdańska. Autorzy przedstawiają wnioski ze zrealizowanych badań na temat wybranych zagadnień związanych ze zmianami klimatycznymi. W pierwszej części tekstu przywołują opracowania dotyczące kwestii klimatycznej i jej obecności w dyskursie ekologicznym, który w ostatnich dwóch dekadach angażuje coraz więcej podmiotów podejmujących działania na rzecz ochrony środowiska przyrodniczego. W drugiej części skupiają uwagę na analizie empirycznej zachowań proekologicznych i ich uwarunkowań społecznych.

  • Spray-Based Method for Protecting and Restoring Historic Adobe Walls Using Nanomontmorillonite Clay
    • Mona Khasar
    • Hamed Niroumand
    • Maryam Afsharpour
    • Lech Bałachowski
    2023 Pełny tekst ACS NANO

    Restoringandprotectinghistoricbuildingsworldwideareimportant becauseheritagebuildingsarerecordsofthecivilizationsofvariouscountries.Herein, nanotechnologywasusedtorestorehistoricadobewalls.AccordingtotheIranPatent andTrademarkOffice(IRPATENT)102665,nanomontmorilloniteclayhasbeen selectedasanaturalandcompatiblematerialwithadobe.Furthermore,ithasbeenused asnanospraytobeaminimallyinvasivemethodtofillcavitiesandcracksintheadobe surface.Variouspercentagesofnanomontmorilloniteclay(1−4%)intheethanolsolvent andthefrequencyofsprayingonthewallsurfacewereevaluated.Scanningelectron microscopyandatomicforcemicroscopyimages,porositytests,watercapillary absorption,andcompressivestrengthtestswereusedtoevaluatetheefficiencyofthe method,analyzecavityfilling,anddetecttheoptimalpercentageofnanomontmorillonite clay.Resultsindicatethatthedoubleuseofthe1%nanomontmorilloniteclaysolution exhibitedthebestresults,filledthecavities,andreducedtheporesonthesurfaceofthe adobe,increasingcompressivestrengthandreducingwaterabsorptionandhydraulic conductivity.Theuseofamoredilutesolutioncausesthenanomontmorilloniteclaytopenetratedeeplyintothewall.This innovativemethodcanhelpmitigatetheexistingdisadvantagesofhistoricadobewalls.

  • Stability Enhancement of Grid-Connected Wind Power Generation System Using PSS, SFCL and STATCOM
    • Muhammad Sarwar
    • Muhammad Arshed
    • Babar Hussain
    • Muhammad Rasheed
    • Hanan Tariq
    • Stanisław Czapp
    • Sarmad Tariq
    • Intisar Ali Sajjad
    2023 Pełny tekst IEEE Access

    The stability related issues may occur in a power system due to disturbances in generating or loading conditions, especially in the presence of distributed generation (DG) based on renewable energy resources (RERs). This paper proposes a novel strategy for the stability enhancement of a wind power generation system (WPGS) by using a combination of three devices, namely, a power system stabilizer (PSS), resistive superconductor fault current limiter (R-SFCL) and static synchronous compensator (STATCOM). The small signal (SS) stability of the test system is enhanced by selecting the best PSS type from the different types of PSS. An R-SFCL is used for improving the rotor angle and the frequency stability of the test system. Two indices, namely, transient stability index and sum of maximum deviations (SMD) index are introduced for determining the optimal locations of different sized R-SFCLs for increasing the rotor angle stability. The sensitivity index (SI) based on the power change between areas is applied for determining the optimal locations of different sized R-SFCLs for enhancing the frequency stability. Along with rotor angle and frequency stability, LVRT capability improvement of the wind farm using STATCOM is also considered. Finally, the combined effect of R-SFCL and STATCOM on the rotor angle and the frequency stability, for different fault locations, is also investigated for determining the optimal location of an R-SFCL in the presence of STATCOM. The results presented in the paper show that STATCOM affects both the number of feasible locations and the optimal locations that can be selected for different sized R-SFCLs for augmenting the rotor angle and the frequency stability of the system during faults. Moreover, it is pointed out that an optimal combination between the different sizes and the locations of R-SFCLs and STATCOM exists to enhance the overall stability of the test system under fault conditions.

  • Stability Investigation of the PCM Nanocomposites
    • Janusz Cieśliński
    • Paulina Boroń
    • Maciej Fabrykiewicz
    2023 Pełny tekst Acta Mechanica et Automatica

    Ensuring the stability is a key issue to be solved for the technical application of nanocomposites. In this work, fatty acid P1801 served as base phase change material (PCM)P1801, and its main ingredients are palmitic acid (58%) and stearic acid (38%). Titania (TiO2) and alumina (Al2O3) with mass concentrations of 1% and 5% were selected as nanoparticles, while polyvinylpyrrolidone (PVP) or oleic acid (OA) with mass concentrations of 5% were tested as surfactants. On the basis of the measured temperature distributions in the sample, which is subject to melting and solidification processes, it was determined which of the tested nanocomposites are stable and which are not. In addition, a thermal test was proposed to assess the stability of the produced nanoPCM, which consists in measuring the temperature distribution versus time according to a precisely given procedure.

  • State Interventionism in Tax System - Example of Action in a COVID-19 Crisis
    • Piotr Kasprzak
    2023 Pełny tekst International Journal of Social Science

    The following article presents and classifies changes in tax systems of selected countries as well as counts them as the response to the emergence of the crisis caused by the COVID-19 pandemic. Such actions were undertaken the context of state interventionism in the tax system. In order to achieve the objective of presenting the state interventionism in the context of tax rates, an analysis of the literature on the phenomenon described, as well as specialised industry reports, were analysed. Among the research methods used are literature studies as well as review and an analysis of reports published by the OECD that dealt with the subject described and analysed in the paper. The article focuses on the presentation of the change in the individual tax burden in the countries selected for analysis. It also focuses on the presentation of tax interventionism as an opportunity for the state to influence the economy against the negative effects of the crisis. It should be noted that crises and crisis situations play an crucial role in the economic life of a country, but their course and ultimate consequences depend on the measures taken by individual countries to reduce the negative effects of their outbreak. The COVID-19 pandemic had a significant impact on changing the macroeconomic perspective and situation of many countries around the globe. The pandemic outbreak had also a negative impact on the functioning of companies (especially SME sector). As a result, governments have decided to introduce various relief measures, including changes in the functioning of tax systems. This should be considered as the state interventionism.

  • Static in vitro digestion model adapted to the general older adult population: an INFOGEST international consensus
    • O Ménard
    • U Lesmes
    • C. S. Shani-Levi
    • A. Araiza Calahorra
    • A. Lavoisier
    • M. Morzel
    • A. Rieder
    • G. Feron
    • S. Nebbia
    • L. Mashiah
    • Ana Andres
    • G. Bornhorst
    • F Carriere
    • L Egger
    • S. Gwala
    • Ana Heredia
    • B Kirkhus
    • Adam Macierzanka
    • R Portmann
    • I Recio
    • V. Santé-Lhoutellier
    • C. Tournier
    • A. Sarkar
    • A Brodkorb
    • Alan Mackie
    • D Dupont
    2023 Pełny tekst Food & Function

    Understanding the mechanisms of food digestion is of paramount importance to determine the effect foods have on human health. Significant knowledge on the fate of food during digestion has been generated in healthy adults due to the development of physiologically-relevant in vitro digestion models. However, it appears that the performance of the oro-gastrointestinal tract is affected by ageing and that a model simulating the digestive conditions found in a younger adult (<65 years) is not relevant for an older adult (>65 years). The objectives of the present paper were: (1) to conduct an exhaustive literature search to find data on the physiological parameters of the older adult oro-gastrointestinal tract, (2) to define the parameters of an in vitro digestion model adapted to the older adult. International experts have discussed all the parameters during a dedicated workshop organized within the INFOGEST network. Data on food bolus properties collected in the older adult were gathered, including food particle size found in older adult boluses. In the stomach and small intestine, data suggest that significant physiological changes are observed between younger and older adults. In the latter, the rate of gastric emptying is slowed down, the pH of the stomach content is higher, the amount of secretions and thus the hydrolytic activities of gastric and intestinal digestive enzymes are reduced and the concentration of bile salts lower. The consensus in vitro digestion model of the older adult proposed here will allow significant progress to be made in understanding the fate of food in this specific population, facilitating the development of foods adapted to their nutritional needs. Nevertheless, better foundational data when available and further refinement of the parameters will be needed to implement the proposed model in the future.

  • Static Shape and Stress Control of Trusses with Optimum Time, Actuators and Actuation
    • Najmadeen Saeed
    • Ahmed Manguri
    • Marcin Szczepański
    • Robert Jankowski
    • Barham. A. Haydar
    2023 Pełny tekst International Journal of Civil Engineering

    Traditional shape and stress control of structures use many actuators and require enormous time to find reasonable solutions that need designers to input specific target displacement and stress. This study employs a linear technique to static shape and stress control of pin-jointed assemblies as a theoretical advancement to prior works and provides a comparative analysis against previously established works. The study evaluates the proposed method using MATLAB to find the optimum set of actuators, and MATLAB and SAP2000 to verify the actuation results obtained through applying the set of actuations to the numericalmodels. The proposed method minimizes the number of trials, count of actuators, and total actuation up to 83%, 73%, and 50%, respectively. Furthermore, the optimum solution could be found in a single trial. The study focuses on the three aspects: (a) finding the optimal count of actuators; (b) optimum amount of actuation using fmincon function; and c) Implementing two-sided inequalities to control equations allowing designers to develop target internal forces and nodal displacements, as domains rather than specific numbers. This improves the optimization process affecting actuator count, total actuation elements, and processing time.

  • Statistical evaluation of the changes in cellulose properties caused by the stepwise solvent exchange and esterification
    • Stefan Cichosz
    • Katarzyna Dems-Rudnicka
    • Marcin Łapiński
    • Aleksandra Jastrzębska
    • Anna Masek
    2023 INDUSTRIAL CROPS AND PRODUCTS

    The objective of the research was to empirically confirm the changes in cellulose reactivity caused by the pre-treatment with solvents of different polarity. Therefore, 5 solvents varying in their polar component of surface tension from 0 to 4.6 mN/m were chosen. Their impact on the biopolymer properties was carefully analysed concerning chemical structure, crystallinity and surface characteristics. It was revealed that the length of 6OH⋯O3′ intermolecular H-bonds increased upon each solvent-exchange from (0.2748 ± 0.0001) nm to approx. 0.2760 nm for non-polar solvents, hence, potentially affecting cellulose structure and availability of active centres capable of reaction. As a consequence of structural variations, dioxane- and toluene-exchanged cellulose exhibited, respectively, the lowest (around 0.6 mJ/m2) and the highest (approx. 3.1 mJ/m2) polar component of surface free energy. Therefore, these samples were esterified. Further investigation successfully confirmed expected differences. Toluene-exchanged sample exhibited degree of substitution oscillating around 20%, while dioxane-exchanged specimen – approx. 7%.

  • Steady-State Vibration Level Measurement of the Five-Phase Induction Machine during Third Harmonic Injection or Open-Phase Faults
    • Adam Muc
    • Marcin Morawiec
    • Filip Wilczyński
    2023 ENERGIES

    Multiphase electric machines are increasingly used in various industries and for electromobility. Complex systems have been developed for the control and powering of multiphase machines, which require verification. The quality of control and the power supply of electric machines is usually evaluated by analyzing various electrical parameters. On the other hand, taking into account the fact that a motor is an electrical-mechanical object, its full diagnostics should also include the analysis of vibration signals to verify the operation of the motor as a mechanical device. In this paper, a sensorless control algorithm was studied and applied to a 5-phase induction motor. Various scenarios were considered; in particular, the operation of the studied motor in the absence of one or two phases and in the case of the introduction of the third harmonic to increase the torque was analyzed. In the scenarios considered, the motor was connected to another machine and operated with no load as well as with a preset load. The results obtained were analyzed in the time and frequency domain and were related to the standards used.

  • Stenty naczyniowe – problematyka i biomateriały
    • Klaudia Malisz
    • Marcin Hellmann
    • Beata Świeczko-Żurek
    2023

    Angioplastyka z opcjonalną implantacją stentu odgrywa ważną rolę w leczeniu chorób układu sercowo-naczyniowego w przebiegu miażdżycy. Obecnie na rynku można znaleźć implanty naczyniowe z różnych materiałów, pomimo tego nadal prowadzone są badania nad nowymi technologiami zapewniającymi lepsze własności mechaniczne, fizykochemiczne i biologiczne powłokom, a także usprawniającymi sposoby uwalniania leków. Stenty uwalniające leki dostarczają środki antyproliferacyjne, co znacznie obniża częstość nawrotów zwężenia w porównaniu ze stentami z czystego metalu. Chociaż w pełni biodegradowalne rusztowania potencjalnie mają zapobiegać późnym powikłaniom, nie osiągnęły jeszcze wyników równoważnych z wynikami konwencjonalnych metalowych stentów uwalniających leki we wczesnych latach po implantacji. Innym rozwiązaniem jest zastosowanie powłok, które nadają wyjątkowych właściwości materiałowi, np. wykorzystując powłoki diamentopodobne lub domieszkując powłokę nanocząstkami. Celem niniejszego artykułu jest przedstawienie najnowszych materiałów do stosowania w kardiologii i angiologii interwencyjnej jako stenty naczyniowe.

  • Sterowanie predykcyjne i fuzja danych w systemie dynamicznego pozycjonowania statku
    • Krzysztof Jaroś
    2023 Pełny tekst

    Rozprawa doktorska poświęcona jest badaniu zastosowania fuzji danych oraz sterowania predykcyjnego w systemie dynamicznego pozycjonowania statku. W pierwszej części pracy przedstawiono historię rozwoju systemów dynamicznego pozycjonowania, różne metody estymacji położenia statku, metody sterowania oraz cel i tezę pracy. Następnie zaprezentowano model matematyczny statku, kinematykę oraz dynamikę. W kolejnej części przedstawiono algorytmy fuzji danych, takie jak filtr Kalmana, rozszerzony filtr Kalmana, nieliniowy obserwator oraz filtr cząsteczkowy. W rozprawie przedstawiono również algorytm kaskadowego połączenia filtru cząsteczkowego i rozszerzonego filtru Kalmana. W kolejnej części zaprezentowano algorytmy sterowania, takie jak PID, regulator backstepping oraz sterowanie predykcyjne. W pracy przedstawiono dwa kierunki badań. Pierwszy dotyczy zadania fuzji danych z wykorzystaniem nadmiarowej struktury pomiarowej dokonującej pomiaru położenia, kursu i prędkości w celu estymacji tych wielkości i zakłóceń środowiskowych. Drugi kierunek badań dotyczy poprawy jakości sterowania statkiem z wykorzystaniem nieliniowego modelu statku w sterowaniu predykcyjnym. Wyniki tych badań wskazują, że połączenie fuzji danych i sterowania predykcyjnego pozwala na zwiększenie dokładności pozycjonowania statku oraz bezpieczeństwa statku w sytuacjach awaryjnych.

  • Stiffness of cold-recycled mixtures under variable deformation conditions in the IT-CY test
    • Mariusz Jaczewski
    • Cezary Szydłowski
    • Bohdan Dołżycki
    2023 Pełny tekst Case Studies in Construction Materials

    Stiffness modulus belongs to the most important properties describing the cold-recycled mixtures (CRM) in terms of their usability in road pavement structures. Previous research proved that this property is strongly dependent on the scheme and conditions of the test (temperature and time of loading) and the time that has passed since the compaction of the specimen or pavement layer. It is a result of the influence of two different types of bonds – hydraulic bonds from cement and bituminous bonds from bituminous emulsion or foamed bitumen. Research presented in this paper showed that the target horizontal deformation values selected during the stiffness modulus test have a strong impact on the obtained results as well. In this paper the popular Indirect Tensile Stiffness Modulus (ITSM) test on cylindrical specimen (IT-CY scheme) was used to show the dependence of the stiffness modulus values on the selected target horizontal deformation level. Research was conducted on four different CRM mixtures and three reference materials. The research proved that even for a narrow deformation range the CRMs do not present linear viscoelastic behavior and display very high effort of material even for typical test conditions. In consequence, they are very prone to failure. Research also proved that CRM mixtures present different rheological behavior than cement concrete or asphalt concrete, and more attention should be given to establishing proper test conditions. Based on the research, it was determined that the recommended target horizontal deformation in IT-CY test of CRM should be reduced to 3 μm.

  • Stochastic optimisation algorithm for optimisation of controller parameters for control of dissolved oxygen in wastewater treatment plant
    • Robert Piotrowski
    • Michał Wonia
    • Adam Wonia
    2023 Journal of Water Process Engineering

    Wastewater treatment plants (WWTPs) are very important facilities for mankind. They enable the removal and neutralisation of man-made pollutants. Therefore, it is important for wastewater treatment plants to operate as efficiently as possible so that the level of pollutants in the treated wastewater meets specific requirements. This paper concerns the design of a hierarchical nonlinear adaptive control system for dissolved oxygen (DO) concentration in wastewater for a biological Sequential Batch Reactor (SBR). The parameters of the control system used are optimised to ensure the best possible control quality and low energy consumption at the same time. Based on data collected from a case study WWTP, an Activated Sludge Model 2d (ASM2d) of the biological processes and a model of the aeration system are applied. The Coyote Optimization Algorithm (COA) is used to optimize the adaptive controller parameters. A Proportional-Integral-Derivative (PID) control system is also developed to compare the control results. The results obtained from simulation studies for both control systems are presented. As a result of optimised parameters, higher wastewater treatment efficiency and reduced electricity consumption are achieved.

  • Stock Markets’ Reactions to the Announcement of the Hosts. An Event Study in the Analysis of Large Sporting Events in the Years 1976–2032
    • Krystian Zawadzki
    • Marcin Potrykus
    2023 Pełny tekst Journal of Sports Economics

    This study attempts to estimate the impact of the announcements of hosts of large sporting events on domestic stock markets. The research problem is to establish a connection between the uniqueness of a sporting event and investors’ beliefs through stock price behavior. Using appropriate estimation windows, 13 different sporting events classified as large, including mega and major events, were tested. The obtained results show that, in principle, one day after the announcement of the host of a large sporting event, an average positive reaction of 0.22% is observed on national stock exchanges. The analyzed events were also classified as being neutral for capital markets or generating positive or negative reactions when the host country is announced to the public.

  • Strategies for Dealing With Software Product Management Challenges
    • Olga Springer
    • Jakub Miler
    • Michał Wróbel
    2023 Pełny tekst IEEE Access

    Software product management, which involves multiple processes and responsibilities and links to many activities within the organisation, increases the success rate of IT projects. However, the adoption of product management activities and the implementation of the software product manager role itself varies between companies. This research explores the topic of software product managers’ strategies for dealing with challenges in their work. The aim of the study is to identify and evaluate solutions to the main problems that affect the software product management process and to provide guidelines for dealing with them. For this purpose, a focus group method was adopted and 47 software product managers participated in 15 focus groups. This was followed by a survey to assess the comprehensibility and effectiveness of the solutions identified. The paper proposes a list of 39 solutions to the 5 most common problems in the work of product managers. Furthermore, based on the identified solutions and the results of discussions with experienced professionals during the focus groups, guidelines for these problems were also developed. These guidelines can be used by product managers as well as other roles working in the product development team to create their own strategies for overcoming software product management challenges and improving software engineering practices. Finally, the solutions and guidelines presented, when combined with a list of problems identified in previous research, will form a Software Product Management Guide – a framework currently under construction, as part of wider research, for product development teams to improve software engineering practices.

  • Strategy towards the use of ultrafiltration and reverse osmosis for industrial water recovery and reuse as part of the Green Deal Implementation
    • Jakub Drewnowski
    • Jan Marjanowski
    • Maciej Sadaj
    • Bartosz Szeląg
    • Joanna Szulżyk-Cieplak
    • Grzegorz Łagód
    2023 Desalination and Water Treatment

    In line with the European Parliament’s Resolution of February 10th, 2021 on the new action plan for a closed economy, most of the activities undertaken in the wastewater treatment process should focus on the search for new technologies that use wastewater as a source of water and nutrients. The paper reviews the concept of water reuse in industrial installations, with special emphasis on the use of membrane technologies for this purpose. The results of authors’ own research on effectiveness of using ultrafiltration (UF) and reverse osmosis (RO) processes to recover process water from brewery wastewater, following pretreatment by the BIOPAQ®-IC process, are presented. Raw wastewater, after averaging the parameters, was digested in an anaerobic reactor, followed by deodorization and oxidation of sulfides to sulfate in an oxidation process in a pretreatment tank. The water recovered from pretreated brewery wastewater by UF and RO membrane techniques was found to be suitable for boiler feed, cooling technology and washing process without directly cleaning beer bottles. The study used a ZeeWeed capillary immersion ultrafiltration module operating under vacuum and a module equipped with a Filmtec XLE 2125 reverse osmosis membrane. The technology improved the efficiency of contaminant removal, yielding purified and high-quality water toward the implementation of the assumptions of Circular Economy and Green Deal Implementation.

  • Stress Relaxation Behaviour Modeling in Rigid Polyurethane (PU) Elastomeric Materials
    • Paweł Zielonka
    • Krzysztof Junik
    • Szymon Duda
    • Tomasz Socha
    • Krzysztof Kula
    • Arkadiusz Denisiewicz
    • Olaleye Kayode
    • Wojciech Macek
    • Grzegorz Lesiuk
    • Wojciech Błażejewski
    2023 Pełny tekst Materials

    Polyurethane (PU) has been used in a variety of industries during the past few years due to its exceptional qualities, including strong mechanical strength, good abrasion resistance, toughness, low-temperature flexibility, etc. More specifically, PU is easily “tailored” to satisfy particular requirements. There is a lot of potential for its use in broader applications due to this structure–property link. Ordinary polyurethane items cannot satisfy people’s increased demands for comfort, quality, and novelty as living standards rise. The development of functional polyurethane has recently received tremendous commercial and academic attention as a result. In this study, the rheological behavior of a polyurethane elastomer of the PUR (rigid polyurethane) type was examined. The study’s specific goal was to examine stress relaxation for various bands of specified strains. We also suggested the use of a modified Kelvin–Voigt model to describe the stress relaxation process from the perspective of the author. For the purpose of verification, materials with two different Shore hardness ratings—80 and 90 ShA, respectively—were chosen. The outcomes made it possible to positively validate the suggested description in a variety of deformations ranging from 50% to 100%.

  • Structural and electronic properties of diamond-composed heterostructures
    • Michał Rycewicz
    2023 Pełny tekst

    Diamond is a promising material for 21st century electronics due to its high thermal and electronic conductivity, biocompatibility, chemical stability, high wear resistance, and possibility of doping. However, the semiconductor properties of diamond, especially free-standing films, have not been fully explored. Nor have their integration with polymers and fragile materials and their applications as electronic components. In this thesis, the objective was the fabrication of heterostructures containing diamond films on flexible surfaces for application in electronic devices using the change of electrical parameters under the influence of external factors. To overcome this scientific challenge, boron-doped diamonds were grown using chemical vapour deposition on tantalum. After their delamination, the resulting free-standing films were investigated and analysed using Raman spectroscopy, Scanning and Atomic Force Microscopy, Nanoindentation Tests, Electrochemical measurements, and Electrical Evaluation as a function of temperature. Next, the diamond films were utilised for fabricating six heterostructures. Based on the conducted research, these heterostructures can be used as durable, transparent electrodes, strain sensors, Schottky or Ohmic junctions, capacitors, trinitrotoluene sensors, and as a protective layer for transistors.

  • Structural and luminescence properties of B2O3-Bi2O3-AlF3 glass doped with Eu3+, Tb3+ and Tm3+ ions
    • Karolina Milewska
    • Michał Maciejewski
    • Marcin Łapiński
    • Anna Synak
    • Mirosław Behrendt
    • Wojciech Sadowski
    • Barbara Kościelska
    2023 JOURNAL OF NON-CRYSTALLINE SOLIDS

    The B2O3-Bi2O3-AlF3 glass system doped with Eu3+, Tb3+, Tm3+ and triply doped with Eu3+/Tm3+/Tb3+ ions in different molar ratios were successfully synthesized. Glass transition and crystallization temperatures were examined by Differential Scanning Calorimetry (DSC) measurements. X-ray Diffraction (XRD) confirmed the amorphous character of the samples. Fourier Transform Infrared Spectroscopy (FTIR) revealed that the glass matrix consists of [BO3] and [BO4] structural units, while X-ray Photoelectron Spectroscopy (XPS) confirmed the presence of AlF3. An increase in luminescence spectra intensity was detected by Photoluminescence Spectroscopy (Pl), due to the presence of 10 mol% of AlF3. The RE3+ ions embedded in the glass matrix can be simultaneously excited by a single UV light. According to the CIE results the emitted color can be tunable by varying the excitation wavelength and sample composition. The presented results confirm that the proposed glass system could be a candidate for color-tunable phosphors in LEDs.

  • Structural insights, biocatalytic characteristics, and application prospects of lignin-modifying enzymes for sustainable biotechnology
    • Anil Kumar Singh
    • Hafiz M N Iqbal
    • Nunzio Cardullo
    • Vera Muccilli
    • Jesús Fernández-Lucas
    • Jens Ejbye Schmidt
    • Teofil Jesionowski
    • Muhammad Bilal
    2023 Pełny tekst INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES

    Lignin modifying enzymes (LMEs) have gained widespread recognition in depolymerization of lignin polymers by oxidative cleavage. LMEs are a robust class of biocatalysts that include lignin peroxidase (LiP), manganese peroxidase (MnP), versatile peroxidase (VP), laccase (LAC), and dye-decolorizing peroxidase (DyP). Members of the LMEs family act on phenolic, non-phenolic substrates and have been widely researched for valorization of lignin, oxidative cleavage of xenobiotics and phenolics. LMEs implementation in the biotechnological and industrial sectors has sparked significant attention, although its potential future applications remain underexploited. To understand the mechanism of LMEs in sustainable pollution mitigation, several studies have been undertaken to assess the feasibility of LMEs in correlating to diverse pollutants for binding and intermolecular interactions at the molecular level. However, further investigation is required to fully comprehend the underlying mechanism. In this review we presented the key structural and functional features of LMEs, including the computational aspects, as well as the advanced applications in biotechnology and industrial research. Furthermore, concluding remarks and a look ahead, the use of LMEs coupled with computational framework, built upon artificial intelligence (AI) and machine learning (ML), has been emphasized as a recent milestone in environmental research.

  • Structural, optical and electrochemical performance of black phosphorus and black arsenic-phosphorus nanostructures
    • Łukasz Macewicz
    2023 Pełny tekst

    Black phosphorus (BP)-based nanostructures have drawn a lot of attention due to their tunable bandgap and extraordinary properties such as: high surface-to-volume ratio, large number of active sites, and prominent edges. However, low dimensional structures of black phosphorus oxidize easily, which hamper their application on a broader scale. One way to overcome these difficulties is to modify the black phosphorus structure by substituting some of the phosphorus atoms for arsenic atoms, forming black arsenic-phosphorus (b-AsP). Despite the broad variety of atomically thin, two-dimensional materials, those with a bandgap range between 0.3 and 1.5 eV are plainly missing. Black phosphorus and black arsenic-phosphorus nanostructures not only correspond to the visible and infrared spectral range, but also possess additional tuning capabilities, which can further influence their electronic properties. In this dissertation, the structural and optical properties of BP and b-AsP nanoflakes and nanoribbons have been investigated. Moreover, surface modification of electrode materials with BP and b-AsP to enhance their electrochemical performance and sensing possibilities was investigated. The electrode materials chosen for BP and b-AsP modification were titania nanotubes (TiO2NTs), commercially available gold array electrodes, and CVD-fabricated polycrystalline boron-doped diamond (BDD) films.

  • Structural, physicochemical and anticancer study of Zn complexes with pyridyl-based thiazolyl-hydrazones
    • Jovana B. Araškov
    • Natalia Maciejewska
    • Mateusz Olszewski
    • Aleksandar Višnjevac
    • Vladimir Blagojević
    • Henrique S. Fernandes
    • Sérgio F. Sousa
    • Adrián Puerta
    • José M. Padrón
    • Berta Barta Holló
    • Miguel Monge
    • María Rodríguez-castillo
    • José M. López-de-luzuriaga
    • Özlem Uğuz
    • Atıf Koca
    • Tamara R. Todorović
    • Nenad R. Filipovići
    2023 JOURNAL OF MOLECULAR STRUCTURE

    Thiazolyl-hydrazones (THs) exhibit a wide spectrum of biological activity that can be enhanced by complexation with various metal ions. Zn(II) complexes with α-pyridine-1,3-TH ligands may represent an alternative to the standard platinum-based chemotherapeutics. In addition, they show photoluminescence properties and thus can be regarded as multifunctional materials. In this study, we synthesized and characterized three neutral Zn(II) complexes (1–3) with pyridine-based TH ligands HLS1‒3 in order to investigate the influence of the ligands charge on the structure and intermolecular interactions in the solid state, and consequently photophysical properties. The deprotonation of the ligands mainly affects the relative energies of electronic levels in the complexes, compared to cationic counterparts, resulting in similar photoluminescence mechanisms and quantum yields with a small shift in emission energy. The influence of the substitution at the ligands’ periphery on the selected quantum molecular descriptors of the complexes is localized to the substitution site. Also, the substituents did not considerably influence the redox responses of the complexes. However, predominant spectral changes were observed in the course of the first reduction and oxidation processes which caused distinct spectral colour changes indicating their possible functionality for electrochromic applications. In addition, complex 1 showed antiproliferative activity with GI50 values below 2 µM on all tested cancer cell lines.

  • Structurally well-defined functionalized polyolefins and graft copolymers thereof as bitumen modifiers
    • Mateusz Malus
    • Joanna Bojda
    • Maciej Sienkiewicz
    • Miloud Bouyahyi
    • Lanti Yang
    • Javier Francisco Navarro
    • Maria Soliman
    • Rob Duchateau
    • Lidia Jasińska-Walc
    2023 CONSTRUCTION AND BUILDING MATERIALS

    Here we demonstrate the application of hydroxyl-functionalized propylene-based copolymers, poly(propylene-co-1-hexene-co-10-undecen-1-ol) (FPP) and poly(styrene-co-maleic anhydride) (SMA) graft copolymers derived thereof, poly(propylene-co-1- hexene-graft-styrene-co-maleic anhydride) (FPP-g-SMA) as bitumen modifiers. The FPP samples were synthesized via solution copolymerization, while FPP-g-SMA products were obtained via transesterification of FPP with SMA either in solution or by a melt-grafting process. FPP-g-SMA modifiers prepared in solution, having a SMA content of around 30 wt.%, performed very well as compatibilizer for bitumen, generating a polymer-modified compositions with a uniform morphology and improved nanomechanical properties, storage stability, rheological properties and high- temperature performance as compared to neat bitumen samples.

  • Structure redetermination, transport and thermal properties of the YNi3Al9 compound
    • Ihor Oshchapovskyy
    • Ebube E. Oyeka
    • Thao Tran
    • Tomasz Klimczuk
    • Michał Winiarski
    2023 Pełny tekst JOURNAL OF SOLID STATE CHEMISTRY

    Single crystals of completely ordered variant of the YNi3Al9 compound were grown by self-flux method with excess of aluminum. The crystal structure of the title compound was redetermined from single crystal X-ray diffraction data. The structure adopts ErNi3Al9 type, space group R32, parameters of the unit cell a ​= ​7.2838(2) Å, c ​= ​27.4004(8) Å. The growth of relatively large single crystals of the YNi3Al9 compound, having completely ordered structure, indicates possible existence of region on phase diagram, where the title compound is in equilibrium with liquid. Comparison with the results in the literature on the investigations of the same and related compounds shows trend towards formation of more ordered structures in flux grown samples and more disordered ones in arc melted samples. Physical properties of the title compound - electrical resistivity, magnetoresistance and heat capacity - were measured for the first time. It shows metallic-like behavior with very high values of magnetoresistance up to 420% at low temperatures without presence of magnetic elements. Therefore electronic structure calculations were carried out. The phonon heat capacity reveals major Debye and minor Einstein contributions at the intermediate temperatures, and total heat capacity approaches Dulong-Petit limit at high temperatures. The calculated Debye temperature from the whole temperature range θD ​= ​480(6) K is typical for aluminium-rich compounds. Corresponding Einstein temperature is θE ​= ​198(8) K. The estimations of electron-phonon coupling constant λ ​= ​0.092 show very weak coupling and absence of superconducting transition.

  • Structured deformation of granular material in the state of active earth pressure
    • Leśniewska Danuta
    • A. Tordesillas
    • Magdale Pietrzak
    • Shuo Zhou
    • Michał Nitka
    2023 COMPUTERS AND GEOTECHNICS

    The paper focuses on the ability of granular materials to undergo structured deformation by analysing the data from the retaining wall model tests and discrete element simulations. The structured deformation means the movement of a granular material which produces a stable, regular pattern of multiple shear bands. The paper's primary purpose is to study this kind of deformation for the selected data representing the state of active earth pressure of granular materials. The locations of high and negligible shear strains (shear zones and 'dead' zones) in the displacement fields are determined using the shear strains definition. A recently introduced metric called s-LID, expressing the perspective of collective grain motion, is applied to the same data. The s-LID analysis finds the detailed structure of the localisation pattern directly from displacement data without using the continuum mechanics concept of strains. It is entirely consistent with the digital image correlation analysis in the areas of significant displacement. It expands the knowledge of the deformation structure in small displacement areas, where the digital image correlation method loses its capability. Low s-LID and point-like representations in the displacement state space identify nearly rigid zones in the area of high displacements.

  • Structure-Property Relationship and Multiple Processing Studies of Novel Bio-Based Thermoplastic Polyurethane Elastomers
    • Joanna Smorawska
    • Marcin Włoch
    • Ewa Głowińska
    2023 Pełny tekst Materials

    Currently, the growing demand for polymeric materials has led to an increased need to develop effective recycling methods. This study focuses on the multiple processing of bio-based thermoplastic polyurethane elastomers (bio-TPUs) as a sustainable approach for polymeric waste management through mechanical recycling. The main objective is to investigate the influence of two reprocessing cycles on selected properties of bio-TPUs. Two series of bio-based TPUs were synthesized via a solvent-free two-step method with the use of hexamethylene diisocyanate or hexamethylene diisocyanate/partially bio-based diisocyanate mixtures, bio-based poly(triamethylene ether) glycol, and bio-based 1,3 propanediol. Both the raw bio-TPUs and those subjected to two reprocessing cycles were examined with respect to their chemical, physical, thermal, thermomechanical, and mechanical properties. The conducted research revealed that reprocessing led to changes in the phase separation between the hard and soft segments, thereby affecting the bio-TPUs’ properties. Both series of materials showed similar chemical structures regardless of reprocessing (slight changes were observed in the range of carbonyl peak). The thermal properties of TPUs exhibited slight differences after each reprocessing cycle, but generally, the non-processed and reprocessed bio-TPUs were thermally stable up to about 300 °C. However, significant differences were observed in their mechanical properties. The tensile strength increased to 34% for the twice-reprocessed bio-TPUs, while the elongation at break increased by ca. 200%. On the other hand, the processing cycles resulted in a decrease in the hardness of both bio-TPU series (ca. 3–4 °ShA). As a result, the prepared bio-TPUs exhibited characteristics that were closer to those of the sustainable materials model, promoting the circular economy of plastics, with environmental benefits arising from their recyclability and their high content of bio-based monomers (78.4–78.8 wt.%).

  • Study of Soil Temperature and Moisture Changes in a Physical Model of an Underground Cable Line
    • Stanisław Czapp
    • Filip Ratkowski
    • Seweryn Szultka
    • Krzysztof Szuchnik
    • Michał Kołtun
    2023

    The ampacity of power cables is highly dependent on the thermal resistivity of the soil in which they are laid. The lower it is, the higher this ampacity. The thermal resistivity of the soil decreases as its moisture increases. Therefore, it is preferable that the soil around the cables has high moisture. Unfortunately, the heat generated in heavily loaded cables causes the migration of moisture from the surrounding soil, which adversely affects the ampacity of these cables. However, it turns out that it is possible to stop the migration of moisture from the immediate vicinity of the cables. The paper presents the results of a long-term experiment (soil/betonite temperature and moisture measurements), which proves that proper protection of the medium around the cables makes it possible to stop the migration of moisture. This has a positive effect on the ampacity of the cables and, thus, on the level of transmitted power.