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Gdańsk University of Technology

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  • SPATIAL AND BEHAVIOURAL COGNITION OF WAYFINDING SYSTEM IN HOSPITAL BUILDINGS IN TERMS OF ONCOLOGY PATIENTS' COMFORT
    • Weronika Mazurkiewicz
    • Michał Sitek
    2024 Architecture Civil Engineering Environment

    This paper discusses the results of a study of the quality of space in hospital buildings in the context of solutions facilitat- ing the orientation of patients in the space of the Outpatient Clinic, in the clinic building complex of the National Institute of Oncology in Gliwice (NIO). By combining qualitative research methods with a syntactic description of the space, the aim was to record the experiences of users and define objective design guidelines for the new visual identity system. Completed research walks testing selected patient routes in the clinic space made it possible to identify decision points as nodal spaces in the wayfinding system. On the other hand, the use of the Space Syntax method allowed the identification of key areas for signage visibility and orientation in space. The proposed method can be adapted for various types of public buildings, pro- viding a flexible framework for pre-design research and analysis. Furthermore, the results show the potential of linking qualitative research methods with simulation-based user participation and digital tools for in-depth pre-design analyses.

  • Spatial variability of the hydrochemistry of shallow groundwaters and surface waters of the Rensdyrbekken: A case study of a permafrost catchment in Bellsund (SW Spitsbergen, Svalbard)
    • Sara Lehmann-konera
    • Piotr Zagorski
    • Kamil Nowinski
    • Krzysztof Raczynski
    • Marcin Frankowski
    • Łukasz Franczak
    • Mateusz Dobek
    • Danuta Szumińska
    • Ruman Marek
    • Ramia Bakain Al
    • Żaneta Polkowska
    2024 Full text LAND DEGRADATION & DEVELOPMENT

    Progressive climate change may have unpredictable consequences for the Arctic environment. Permafrost catchments off the west coast of Svalbard, described as “thin” and “warm,” are particularly sensitive to climate change. The interdisciplinary research on the hydrochemical response of surface and underground water functioning within a small permafrost catchment area focused on the determination of the impact of meteorological conditions (temperature (T), precipitation (P)) on the mean daily discharge (Q), and the lowering of the groundwater table (H). We determined physical and chemical properties (pH and SEC) and concentrations of major elements (Ca, Mg, Na, K) and 23 trace elements (i.a. Cd, Cu, Hg, Pb, Zn) in 280 water samples. The results of the correlation matrix showed that an increase in the average air temperature in the summer of 2021 had a significant impact on the hydrochemistry of both types of waters operating in the catchment. In response to increase in T, the lowering of the H (0.52 < r < 0.66) and a decrease in Q (0.66 < r < 0.68) were observed what in consequence also leads to changes in water chemistry. The principal component analysis (CA) indicates that chemical weathering and binding of elements to DOC are processes influencing water chemistry. Results of statistical analysis showed that the resultant of the hydrometeorological conditions that prevailed in that season and the type of geological formations on which they were located had a significant impact on the water chemistry at individual measurement points. Significant differences in the concentrations of elements between points on the same geological formations were also found.

  • Specification-Oriented Automatic Design of Topologically Agnostic Antenna Structure
    • Adrian Bekasiewicz
    • Mariusz Dzwonkowski
    • Tom Dhaene
    • Ivo Couckuyt
    2024

    Design of antennas for modern applications is a challenging task that combines cognition-driven development of topology intertwined with tuning of its parameters using rigorous numerical optimization. However, the process can be streamlined by neglecting the engineering insight in favor of automatic de-termination of structure geometry. In this work, a specification-oriented design of topologically agnostic antenna is considered. The radiator is developed using a bi-stage algorithm that involves min-max classification of randomly-generated topologies followed by local tuning of the promising designs using a trust-region optimization applied to a feature-based representation of the structure frequency response. The automatically generated antenna is characterized by –10 dB reflection for over 600 MHz around the center frequency of 6.5 GHz and a dual-lobe radiation pattern. The obtained performance figures make the radiator of use for in-door positioning applications. The design method has been favorably compared against the frequency-based trust-region optimization.

  • Spectroscopic studies on physicochemical properties of selected unsymmetrical bisacridine derivatives and NMR analysis of their interactions with the model sequence Pu22 aided by molecular dynamics
    • Michał Kosno
    2024 Full text

    In recent years, new promising acridine derivatives have appeared, belonging to the unsymmetrical bisacridines (UAs) family with high anticancer activity. Both their physicochemical properties and their mechanism of action at the molecular level have not been thoroughly analyzed so far. Four derivatives were selected for the study, termed as: C-2028, C-2041, C-2045 and C-2053. The first aim of this work was to determine the protonation forms in which the studied compounds exist at different pH. The second aim was the analysis of aggregation process at different conditions. Methods such as UV-Vis and NMR spectroscopy were used for this purpose. The obtained spectral data were subjected to a thorough chemometric analysis, using techniques such as principal components analysis, multiple regression and numerical optimization. Previous studies have shown that a potential molecular target for unsymmetrical bisacridines may be the promoter sequence of the C-Myc proto-oncogene, known as Pu22. Next goal of the presented work was to determine the interactions of the studied compounds with the above mentioned sequence using advanced NMR spectroscopy and molecular dynamics methods. These studies were narrowed down to the two most promising derivatives: C-2045 and C-2053. In order to determine the exact molecular structure of the obtained complexes, a series of one- and two-dimensional NMR spectra of both investigated compounds and their monomeric derivatives (C-1311 and C-1748) were recorded, which allowed to build the initial structures of the studied complexes. In the next step, they were subjected to an equilibrium MD simulation. In the final stage of the research, the nature and strength of the interactions between the studied compounds and the selected G-quadruplex were estimated using the umbrella sampling method, which allowed the determination of the free energy profiles of the obtained complexes. The results obtained allowed to determine the way in which the unsymmetrical bisacridines interact with the C-Myc promoter sequence - their potential molecular target. In addition, their basic physicochemical properties have been determined, which will allow further research on the compounds described above. In this work, a simple and reliable method for the determination of physicochemical constants has been developed and presented, which yields well credible results, even in the case of compounds with a complex structure having many sites capable of protonation.

  • Społeczna opieka nad zabytkami - doświadczenia z ostatnich kilkunastu lat z Gdyni
    • Robert Hirsch
    • Celina Łozowska
    2024 Full text Ochrona Dziedzictwa Kulturowego

    W artykule przedstawiono analizę funkcjonowania społecznej opieki nad zabytkami w Gdyni po 2003 r. Kilkanaście lat doświadczenia samorządu lokalnego oraz czas jaki upłynął od wejścia w życie obowiązujących regulacji związanych z instytucją społecznych opiekunów zabytków pozwalają na sformułowanie wniosków i pokazanie wad oraz zalet różnych rozwiązań. W artykule przedstawiono doświadczenia Biura Miejskiego Konserwatora Zabytków w Gdyni ze współpracy zarówno ze społecznymi opiekunami zabytków jak i z lokalnymi stowarzyszeniami zajmującymi się ochroną dziedzictwa. Z doświadczeń autorów wynika jednoznacznie, że przepisy ustawy o ochronie zabytków i opiece nad zabytkami, regulujące działalność społecznych opiekunów zabytków są anachroniczne i w praktyce mają minimalny wpływ na ochronę zabytków. Natomiast rozwinęła i rozwija się działalność społeczna aktywnych mieszkańców z wykorzystaniem stowarzyszeń i innych form kolektywnego współdziałania. Dużą rolę odgrywają obecnie portale internetowe a zwłaszcza media społecznościowe, które ułatwiają komunikację i pozwalają szybko reagować. Widoczne jest ogromne zainteresowanie społeczne ochroną zabytków i spora aktywność mieszkańców w tym zakresie. W ocenie autorów należy skorzystać z nowych doświadczeń i całkowicie przeformułować zasady współpracy organów ochrony zabytków ze społeczeństwem. Taka współpraca może przynieść korzystne efekty.

  • Sport as a Tool for the Development of Healthy and Sustainable Cities: A Strategic Documentation Review
    • Aleksander Orłowski
    • Narek Parsamyan
    2024

    The rapidly changing cities and their environment are causing new challenges for which actions and solutions must be sought. Most of all, a major challenges facing cities are adverse environmental changes and issues related to public health and citizens well-being. Sport is present in the lives of most of us and is an essential component of urban infrastructure, while in relation to this, to what extent is it being used to support health and sustainable goals, shaping cities of tomorrow. The area of relevance of sport for healthy and sustainable cities has not been explored in depth so far. The study aims to examine the sport dimensions and sport factors that contribute to healthy and sustainable city frameworks, through a literature review and analysis of international institutions' policy documents and metrics. The study will contribute to broader understanding of the role of sport within the framework of healthy and sustainable cities and creates the paradigm of future considerations of the relevance of sport from the perspective of city management and policy maker. The novelty of this study is the use of primary sources (strategic documents) for analysis, being a relevant step for the further process of identifying the sport role towards healthy and sustainable cities.

  • Sport-related concussion alters cerebral hemodynamic activity during controlled respiration
    • Cody A. Ellingson
    • Jyotpal Singh
    • Chase J. Ellingson
    • M. Abdullah Shafiq
    • Luke W. Sirant
    • Kim D. Dorsch
    • Marcin Gruszecki
    • Gregory Kratzig
    • J Neary
    2024 JOURNAL OF NEUROPHYSIOLOGY

    This study investigated cerebral hemodynamic activity following sport-related concussion. Prefrontal cortex oxygenation was assessed by near-infrared spectroscopy (NIRS) during a controlled breathing protocol. Wavelet transformation of the NIRS signals showed significant decreases in HbO2 and HbD amplitude at the respiratory frequency interval (0.10–0.6 HZ) from preseason baseline to acute concussion. These results suggest a decreased respiratory contribution to cerebral hemodynamic activity following acute concussion.

  • Standardy dostępności do Zintegrowanych Węzłów Przesiadkowych
    • Kazimierz Jamroz
    • Marek Wysocki
    • Jacek Szmagliński
    • Romanika Okraszewska
    • Łukasz Jeliński
    • Anna Gobis
    2024

    Wiele z istniejących węzłów wymaga integracji pomiędzy poszczególnymi rodzajami transportu pasażerskiego i dostosowania do wymagań osób ze szczególnymi potrzebami, co jest związane z opracowaniem jednolitych standardów dostępności, jednolitej procedury i narzędzi przeprowadzenia oceny dostępności tych węzłów dla OzSP i zaproponowania skutecznych i efektywnych usprawnień. Problemy z samodzielnym i bezproblemowym przemieszczaniem się uwidaczniają się w zależności od klasy i wielkości węzła przesiadkowego (międzynarodowy, krajowy, regionalny, lokalny), jego dostępności, jakości infrastruktury i systemu obsługi. Różnice między przyjętymi rozwiązaniami i stosowanymi udogodnieniami występować mogą nie tylko między węzłami, ale również w obszarze jednego węzła, w zależności od obszaru lub elementu węzła. Sytuacja ta wynika z braku spójnych zasad projektowania obszarów węzłów transportowych traktowanych jako całość, niezależnie od rodzaju podsystemu i odpowiedzialnej jednostki. Nawet w sytuacji stosowania rozwiązań uwzględniających potrzeby poszczególnych grup OzSP, w przypadku braku spójnego podejścia dla niektórych grup – jak np. osoby niewidome – wielość rozwiązań i brak standaryzacji może również stanowić barierę. Dlatego w ramach projektu „Przesiadka bez Barier” podjęto wyzwanie zwiększenia dostępności węzłów przesiadkowych poprzez opracowanie spójnych zasad dla wszystkich elementów Zintegrowanego Węzła Przesiadkowego (budynków, ciągów pieszych, przystanków). Zasady te zebrano i przedstawiono w dokumencie zatytułowanym „Zintegrowane Węzły Przesiadkowe. Standardy Dostępności” (dalej zwanym Standardami Dostępności). Opracowany dokument z jednej strony integruje już istniejące standardy, a dodatkowo rozszerza je o zasady dla miejsc styku infrastruktury poszczególnych rodzajów transportu. Holistyczne podejście, zestawienie zbioru zasad i wytycznych odnoszących się do całego obszaru i wszystkich elementów węzła są podstawą spójnej w skali kraju oceny dostępności ZWP.

  • Static and dynamic concrete calculations: Breakable aggregates in DEM model
    • Michał Nitka
    2024 Journal of Building Engineering

    The paper deals with the calculations of a 3-point bending beam under static and dynamic loads. The real microstructure was obtained from laboratory tests using micro-tomography images. The quasi-static results were compared directly with experimental data at both macro and micro levels. Subsequently, higher strain rates were applied to investigate dynamic effects. The study focused on the influence of dynamic loading on the macroscopic stress-strain curve, crack propagation, the number of broken contacts, and the distribution of forces and stresses. Special attention was given to micro-fracture and cracking. The calculations were performed using the discrete element method (DEM) and were limited to a 2D problem. The proposed model introduced the consideration of aggregate breakages, which is a novel aspect compared to our previous computations. Fragmentation of the aggregate is particularly important in dynamic tests due to the release of higher energy. Finally, a beam with weak aggregate was used to validate the effectiveness of the model.

  • Statistical Data Pre-Processing and Time Series Incorporation for High-Efficacy Calibration of Low-Cost NO2 Sensor Using Machine Learning
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    • Marek Wójcikowski
    • Bogdan Pankiewicz
    2024 Full text Scientific Reports

    Air pollution stands as a significant modern-day challenge impacting life quality, the environment, and the economy. It comprises various pollutants like gases, particulate matter, biological molecules, and more, stemming from sources such as vehicle emissions, industrial operations, agriculture, and natural events. Nitrogen dioxide (NO2), among these harmful gases, is notably prevalent in densely populated urban regions. Given its adverse effects on health and the environment, accurate monitoring of NO2 levels becomes imperative for devising effective risk mitigation strategies. However, the precise measurement of NO2 poses challenges as it traditionally relies on costly and bulky equipment. This has prompted the development of more affordable alternatives, although their reliability is often questionable. The aim of this article is to introduce a groundbreaking method for precisely calibrating cost-effective NO2 sensors. This technique involves statistical preprocessing of low-cost sensor readings, aligning their distribution with reference data. Central to this calibration is an artificial neural network (ANN) surrogate designed to predict sensor correction coefficients. It utilizes environmental variables (temperature, humidity, atmospheric pressure), cross-references auxiliary NO2 sensors, and incorporates short time series of previous readings from the primary sensor. These methods are complemented by global data scaling. Demonstrated using a custom-designed cost-effective monitoring platform and high-precision public reference station data collected over five months, every component of our calibration framework proves crucial, contributing to its exceptional accuracy (with a correlation coefficient near 0.95 concerning the reference data and an RMSE below 2.4 µg/m3). This level of performance positions the calibrated sensor as a viable, cost-effective alternative to traditional monitoring approaches.

  • Statistical Method for Analysis of Interactions Between Chosen Protein and Chondroitin Sulfate in an Aqueous Environment
    • Piotr Weber
    • Piotr Bełdowski
    • Adam Gadomski
    • Krzysztof Domino
    • Piotr Sionkowski
    • Damian Ledziński
    2024

    We present the statistical method to study the interaction between a chosen protein and another molecule (e.g., both being components of lubricin found in synovial fluid) in a water environment. The research is performed on the example of univariate time series of chosen features of the dynamics of mucin, which interact with chondroitin sulfate (4 and 6) in four different saline solutions. Our statistical approach is based on recurrence methods to analyze chosen features of molecular dynamics. Such recurrence methods are usually applied to reconstruct the evolution of a molecular system in its reduced phase space, where the most important variables in the process are taken into account. In detail, the analyzed time-series are spitted onto sub-series of records that are expected to carry meaningful information about the system of molecules. Elements of sub-series are splinted by the constant delay-time lag (that is the parameter determined by statistical testing in our case), and the length of sub-series is the embedded dimension parameter (using the Cao method). We use the recurrent plots approach combined with the Shannon entropy approach to analyze the robustness of the sub-series determination. We hypothesize that the robustness of the sub-series determines some specifics of the dynamics of the system of molecules. We analyze rather highly noised features to demonstrate that such features lead to recurrence plots that graphically look similar. From the recurrence plots, the Shannon entropy has been computed. We have, however, demonstrated that the Shannon entropy value is highly dependent on the delay time value for analyzed features. Hence, elaboration of a more precise method of the recurrence plot analysis is required. For this reason, we suggest the random walk method that can be applied to analyze the recurrence plots automatically.

  • Sterowanie napięciem pracy kabli eksportowych morskich farm wiatrowych
    • Jacek Klucznik
    2024 Full text Przegląd Elektrotechniczny

    Referat przestawia problematykę doboru napięcia pracy kabli eksportowych morskich farm wiatrowych. Wskazano, że praca przy napięciu odbiegającym od napięcia znamionowego kabli może skutecznie ograniczyć straty energii jakie występują w sieci farmy. Zaproponowano uzależnienie napięcia pracy kabla od generowanej przez farmę mocy czynnej, na wzór stosowanych w przeszłości w regulatorach napięcia transformatorów układów kompensacji prądowej. Dla przykładowej farmy morskiej o mocy zainstalowanej 510 MW uzyskano zmniejszenie rocznych strat energii o około 3%.

  • Stiffness assessment of the laminate recovered from end-of-life wind turbine blade
    • Łukasz Pyrzowski
    • Agnieszka Sabik
    • Jacek Kluska
    • Jakub Zembrzuski
    2024 COMPOSITE STRUCTURES

    In the paper the stiffness parameters of the laminate recovered from an aerodynamic shell of a decommissioned wind turbine blade are evaluated. The aim of the work is to assess selected methods for identifying material data, as well as to estimate the level of stiffness degradation during turbine operation. Several practical identification methods are presented and compared. Two concepts of a single laminate layer are considered, global and local. The global concept assumes that the equivalent layer of the laminate is a system of three physical layers of a single triaxial fabric. The local concept takes into account all physical layers of the laminate. The material parameters of the global layer are identified and validated in experimental tests. Data for individual physical layers are determined by inverse analysis and the rule of mixtures. The compliance of the results obtained allows one to conclude that the stiffness of the material did not degrade significantly during the operation period. The stiffness parameters of the laminate have shown that the tested material is still very attractive for structural purposes.

  • Storage of High-Strength Steel Flux-Cored Welding Wires in Urbanized Areas
    • Adrian Wolski
    • Aleksandra Świerczyńska
    • Grzegorz Lentka
    • Dariusz Fydrych
    2024 Full text International Journal of Precision Engineering and Manufacturing-Green Technology

    The condition of the consumables is a key factor determining the waste reduction in the welding processes and the quality of the welded joint. The paper presents the results of tests of four types of fux-cored wires dedicated for welding high-strength steels, stored for 1 month and 6 months in Poland in two urbanized areas: in a large seaside city (Gdańsk) and in Warsaw, located in the center of the country. The wires were subjected to macroscopic and microscopic (stereoscopic, SEM) observations, EDS analysis, technological tests assessing elastic properties and targetability. The degree of degradation of the wires was also tested using resistance measurements. In order to assess the efect of storing wires on the weldability of steel, the difusible hydrogen content in deposited metal was determined by high-temperature extraction. It was found that the storage caused changes in the surface condition of the wires, afected their elasticity and electrical properties, which afects the behavior of the wires during welding. A signifcant infuence of storage conditions on the hydrogenation of deposited metal was found: in the case of three types of wires, the level of low hydrogen processes was exceeded and the maximum result was 15.18 ml/100 g of deposited metal. It was also found that copper-plated wire showed a signifcantly increased resistance to storage conditions compared to non-copper-plated wires.

  • Strain energy density and entire fracture surface parameters relationship for LCF life prediction of additively manufactured 18Ni300 steel
    • Wojciech Macek
    • Ricardo Branco
    • Joel de Jesus
    • José Domingos Costa
    • Shun-Peng Zhu
    • Reza Masoudi Nejad
    • Andrew Gryguć
    2024 Full text INTERNATIONAL JOURNAL OF DAMAGE MECHANICS

    In this study, the connection between total strain energy density and fracture surface topography is investigated in additively manufactured maraging steel exposed to low-cycle fatigue loading. The specimens were fabricated using laser beam powder bed fusion (LB-PBF) and examined under fully-reversed strain-controlled setup at strain amplitudes scale from 0.3% to 1.0%. The post-mortem fracture surfaces were explored using a non-contact 3D surface topography measuring system and the entire fracture surface method. The focus is on the relationship between fatigue characteristics, expressed by the total strain energy density, and the fracture surface topography features, represented by areal, volume, and fractal dimension factors. A fatigue life prediction model based on total strain energy density and fracture surface topography parameters is proposed. The presented model shows good accordance with fatigue test results and outperforms other existing models based on the strain energy density. This model can be useful for post-failure analysis of engineering elements under low-cycle fatigue, especially for materials produced by additive manufacturing (AM).

  • Strain-dependent behaviour of cold recycled material mixtures in cyclic compression tests
    • Mariusz Jaczewski
    • Andrea Graziani
    2024 Full text MATERIALS AND STRUCTURES

    The purpose of the study is to evaluate strain-dependent behaviour of Cold Recycled Material (CRM) mixtures using three frameworks typically applied for Hot Mix Asphalt (HMA): linear viscoelastic (LVE) limits; non-linearity directions; changes in rheological model parameters. To this aim, the complex modulus of three CRM mixtures with different bitumen-to-cement ratio (0.2, 0.6 and 1.8) was measured in cyclic compression mode, at increasing level of axial deformation (from 35 to 195 μstrain) and at three temperatures (4, 20 and 40 °C). CRM mixtures showed strong strain dependent behaviour, which does not fully comply with the LVE hypothesis. LVE limit framework is applicable, but strain limits for CRM are different from HMA. Linearity direction framework does not give unique trend, hence it is not applicable in the same way as it was developed for HMA. The most promising framework for further analysis is the change in rheological model parameters, but it requires high number of performed tests.

  • STRATEGIC PARTNERSHIPS IN THE DEVELOPMENT OF THE POLISH BIOTECHNOLOGY INDUSTRY
    • Piotr Grudowski
    • Sylwia Sieracka
    2024 Zeszyty Naukowe Politechniki Śląskiej. Seria Organizacja i Zarządzanie

    Purpose: Identification of causative factors and the resulting benefits regarding strategic partnerships in developing biotechnology enterprises in Poland. Design/methodology/approach: Analysis of the literature on the subject, in-depth interviews, case studies and participant observations. Findings: Effective strategic partnerships in Poland are few. They intertwine with other forms of cooperation, striving to create an innovation ecosystem that can increase the commercialisation of the work being carried out. Research limitations/implications: The biotechnology enterprise sector does not maintain a register of strategic partnerships. Enterprises do not willingly disclose newly developed technologies. The research is of a pilot nature and requires continuation. Practical implications: No register of strategic partnerships could guide the government in developing cooperation. Identify the sector's needs and measure the effectiveness of concluded partnerships (evaluation) and the directions of collaboration undertaken. Originality/value: Identification of strategic partnerships in the biotechnology industry in Poland compared to other countries.

  • Stress Assessment of a Steel Bullet LPG Tank Under Differential Settlement Based on Geodetic Measurements and Sensitivity Analysis
    • Tomasz Ferenc
    • Rafał Gierasimczyk
    • Tomasz Mikulski
    2024 Full text Polish Maritime Research

    This paper presents an analysis of a steel bullet LPG tank in operation at a base in Poland. The structure was set on a sand-gravel pillow and rigid concrete slab, and its settlement was periodically measured at five measuring points along the structure. After a few years, differential settlement was observed. Based on geodetic data, we attempt to assess the current stress level in the structure. The proposed methodology uses a sensitivity analysis apparatus. A numerical model of the structure and sand-gravel pillow is analysed using the finite element method, and the impact of variation in the stiffness of the sand-gravel pillow on the vertical displacement of the tank is determined. The algorithm involves six iterations of calculations, and after each iteration, the stiffness modified sand-gravel pillow is determined. After the sixth iteration, the vertical displacement in the FEM model is found to be similar to the measured values in the real structure. The results obtained after the last iteration are used to assess the stress state in the bullet tank’s shell structure.

  • Structural phase transitions in multicomponent La0.2Nd0.2Sm0.2Gd0.2RE50.2NbO4 (RE5 = Ho, Y, Tb, Eu, Pr) oxides
    • Arkadiusz Dawczak
    • Aleksandra Mielewczyk-Gryń
    • Maria Gazda
    2024 Full text JOURNAL OF THE AMERICAN CERAMIC SOCIETY

    In this work, the influence of compositional complexity on the structural and thermal properties of multicomponent rare-earth ortho-niobates from the La0.2Nd0.2Sm0.2Gd0.2RE50.2NbO4 (RE5 = Ho, Y, Tb, Eu, Pr) series have been investigated. Based on X-ray powder diffraction studies using synchrotron radiation, it was found that all tested materials were pure single-phase compositions and showed stability in the monoclinic I2/c crystal structure at room temperature. High-temperature X-ray powder diffraction studies and dilatometry studies confirmed the presence of a structural phase transition between low- (I2/c ) and high-temperature (I41/a) polymorphs. The structural phase transition temperatures are between 676 °C and 701 °C. Interestingly, despite their compositional complexity, the structural phase transition temperature behaves similarly to conventional ortho-niobates, i.e. it depends on the radius of the A-cation, that is, as the ionic radius increases, the phase transition temperature decreases. The transition has been categorized as a second-order phase transition based on the observed relationship between the Landau order parameter and spontaneous strain. The coexistence of the tetragonal and monoclinic phases has been seen in all compositions around the temperature of the structural phase transition. The presence of two orientation states in the monoclinic structure leads to the so-called spontaneous strain, which consists of longitudinal (u) and shear (v) strain components. The values of these strains at 300 °C range between 2.42 – 2.58·10-2 for longitudinal, 2.98 – 3.04·10-2 for shear, and 5.46 – 5.57·10-2 for scalar spontaneous strain. It was found that the spontaneous strain in each of the materials under test was very little impacted by the variation in the complexity of the A sublattice's composition. In addition, thermal expansion coefficients of both polymorphs were determined, which range from 12.7·10-6 1/K to 13.2·10-6 1/K for the monoclinic structure and 9.7·10-6 1/K to 9.9·10-6 1/K for the tetragonal one.

  • Structure versus hydrolytic and thermal stability of bio-based thermoplastic polyurethane elastomers composed of hard and soft building blocks with high content of green carbon
    • Ewa Głowińska
    • Joanna Smorawska
    • Joanna Niesiobędzka
    • Janusz Datta
    2024 Full text JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY

    Nowadays, sustainability plays a key role in the design and synthesis of new materials. One of the methods for the preparation of green materials is incorporation into their structure the monomers with a high content of green carbon. Therefore, the aim of this work was to investigate the influence of the type and molecular mass of two bio-based polyester polyols and bio-glycol on the properties of aliphatic partially bio-based thermoplastic polyurethane elastomers (bio-TPU). Two series of bio-TPUs materials composed of hard and soft building blocks with high green carbon content were prepared via the two-step method (prepolymer method). Two amorphous bio-based polyester polyols with the molecular mass ~ 2000 (P1) and ~ 3000 (P2) were used. Bio-TPUs were prepared at three different molar ratio of [NCO]/[OH]: 0.9, 0.95, and 1.0. In order to determine the influence of bio-based polyols and the content of hard segments on the properties of bio-TPU, relevant test methods were used. The Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogravimetry (TG) revealed hydrolytic and thermal stability of bio-TPUs. Viscoelastic behavior, mechanical and physical properties were examined in terms of dynamic mechanical thermal analysis (DMTA), tensile test, hardness, and density. Analysis of the measurement results confirmed the significant influence of the molecular mass of the bio-based polyols and the molar ratio of [NCO]/[OH] on the bio-TPUs properties. Due to good mechanical properties, low density, and thermal stability up to 300 °C, the obtained materials can find many useful applications. This issue is essential in terms of sustainable development and reduction in the CO 2 emissions to the atmosphere.

  • Studies of the Interaction Dynamics in Albumin-Chondroitin Sulfate Systems by Recurrence Method
    • Piotr Bełdowski
    • Piotr Weber
    • Adam Gadomski
    • Piotr Sionkowski
    • Natalia Kruszewska
    • Krzysztof Domino
    2024

    The physicochemical basis of lubrication of articular cartilage is still not fully understood. However, the synergy between components of the synovial fluid can be a crucial factor that could explain this phenomenon. This work presents a nonlinear data analysis technique named the recurrence method, applied to the system involving two components of synovial fluid: albumin and chondroitin sulfate (CS) immersed in a water environment. This analysis is performed in order to obtain the ”statistical fingerprint” of the dynamics of the interaction between the molecules and to answer whether the variables are more deterministic or more random. The system simulation has been prepared by molecular docking method followed by molecular dynamics simulations. The already mentioned recurrence method has been applied to the time series of the energy of binding, and the time series of the number of intermolecular hydrogen bonds, as these features describe well binding between the two molecules. In detail, the time delay approach and embedded dimension approach have been applied to extract meaningful records from time series. Then, by means of recurrence plots and entropy approach, we discuss the similarities and differences between the molecular systems consisting of CS-4 and CS-6 molecules. Our main finding is a higher affinity of chondroitin sulfate IV to albumin as compared with chondroitin sulfate VI.

  • Study of Nanohydroxyapatite Coatings Prepared by the Electrophoretic Deposition Method at Various Voltage and Time Parameters
    • Klaudia Malisz
    • Beata Świeczko-Żurek
    • Jean Marc Olive
    • Grzegorz Gajowiec
    • Gilles Pecastaings
    • Aleksandra Laska
    • Alina Sionkowska
    2024 Full text Materials

    The aim of the work is to compare the properties of nanohydroxyapatite coatings obtained using the electrophoretic deposition method (EDP) at 10 V, 20 V, and 30 V, and with deposit times of 2 and 5 min. The primary sedimentation was used to minimize the risk of the formation of particle agglomerates on the sample surface. Evaluation of the coating was performed by using a Scanning Electron Microscope (SEM), Energy-Dispersive Spectroscopy (EDS), Atomic Force Microscopy (AFM), optical profilometer, drop shape analyzer, and a nanoscratch tester. All of the coatings are homogeneous without any agglomerates. When low voltage (10 V) was used, the coatings were uniform and continuous regardless of the deposition time. The increase in voltage resulted in the formation of cracks in the coatings. The wettability test shows the hydrophilic behavior of the coatings and the mean contact angle values are in the range of 20–37° . The coatings showed excellent adhesion to the substrate. The application of a maximum force of 400 mN did not cause delamination in most coatings. It is concluded that the optimal coating for orthopedic implants (such as hip joint implants, knee joint implants or facial elements) is obtained at 10 V and 5 min because of its homogeneity, and a contact angle that promotes osseointegration and great adhesion to the substrate.

  • Study of the optical rotatory of potassium titanyl phosphate using the advanced dual-wavelength polarimetric method
    • Mykola Shopa
    • Nazar Ftomyn
    • Yaroslav Shopa
    2024 Full text OPTO-ELECTRONICS REVIEW

    A dual-wavelength high-accuracy universal polarimeter was applied to the circular birefringence and optical activity measurement in potassium titanyl phosphate (KTP) nonlinear crystal. The experimental setup used two single-mode He-Ne lasers with close wavelengths of 594 and 633 nm as light sources. Measurement has been carried out for two crystal settings in directions of a 45-degree relative angle to the [100] and [010] crystallographic axes. Multiple light reflections inside the crystal sample were considered when processing the results of the polarimetric measurements. The results have been analysed using the optical transmission function for the polariser-sample-analyser system, and 2D intensity contour maps made it possible to determine the phase parameters, systematic errors, and eigenwaves ellipticity. It was found that the gyration tensor component of the KTP crystal is equal to g12 = 1.4 ⋅10−5 which in terms of optical rotatory power corresponds to the very small magnitude of the rotation value of 2.3 deg/mm

  • Study on extraction and characterization of anchote (Coccinia abyssinica) starch and reinforced enset (Ensete ventricosum) fiber for the production of reinforced bioplastic film
    • Samuel Latebo Majamo
    • Temesgen Amibo
    2024 Full text Heliyon

    Population expansion is causing an increase in dependence on plastic materials. The worst aspects of conventional plastics were their inability to biodegrade, their poor capacity to transmit water vapor, and their production of greenhouse gases. Usages of bioplastics are necessary for the advancement of a green economy and environment in order to eradicate these drawbacks of traditional plastics. In this study, reinforced bioplastic film was produced from anchote (Coccinia Abyssinica) starch and enset (Ensete Ventricosum) fiber. Starch from anchote was extracted and its properties were characterized via adequate techniques. The maximum carbohydrate content (86.26 ± 0.25%w/w) of anchote starch indicates that it is suitable feedstock for plastic film production. In addition, extracted starch was characterized by SEM, FTIR, TGA and XRD. The reinforcing material enset fiber was extracted and characterized by FTIR and XRD. The results of both feedstock materials exhibited the good characteristics and viability for bioplastic film pro- duction. Enset fiber loadings used were 0 %, 4 %, 8 %, 12 % and 16 % w/w in starch basis. Tensile strength, elongation, thickness, moisture content, transparency, solubility and density of pro- duced bioplastic were determined. Tensile force grew and elongation reduced as fiber loading rose up to 8 %. The tensile strength gradually declined with increasing fiber loading. Additionally, the created bioplastic film’s groups of functions and chemical bonds were examined. In com- parison to unreinforced plastic film, the results showed that the reinforced bioplastic film used in this study was an excellent and effective product.

  • Study on the wear characteristics of a 3D printed tool in flat lapping of Al2O3 ceramic materials
    • Mariusz Deja
    • Dawid Zieliński
    • Sisay Workineh Agebo
    2024 Full text WEAR

    Widespread and popular use of ceramic products in various industry sectors necessitates the search for methods of their efficient processing. Lapping technology, which enables obtaining high dimensional and shape accuracy and high surface flatness, is one of the basic methods of finishing hard and brittle technical ceramics with a porous structure. This study analyzed the characteristics and wear value of an SLS-printed abrasive tool intended for single-sided lapping of Al2O3 technical ceramics. As earlier research demonstrated, introduction of a 3D printed lapping plate by selective laser sintering (SLS), leads to a significant development in the field of precision machining technology. This method showed not only efficient machining performance on oxide technical materials, but was also characterized by relatively low abrasive wear. Straightness errors were evaluated with the use of a least-squares method (LSQ) and minimum zone method based on control line rotation scheme (CLRS). The proposed model proved the experimental results by identifying a similar location of a higher contact density on the lapping tool, where this location is expected to be the one for bigger wear. Surface topography of the lapping tool depends on the tool wear intensity and as a consequence on its shape error. An SLS-printed lapping plate, by obtaining good technological effects, revealed its potential ability in machining hard and brittle technical ceramics.

  • Study the impact of design method preference on the usefulness of concrete and on CO2 emissions
    • Salem Abdelgader
    • Marzena Kurpińska
    • Hakim S. Abdelgader
    • Farzam Omidi Moaf
    • Mugahed Amran
    2024 International Journal of Building Pathology and Adaptation

    Purpose – The research investigates the impact of concrete design methods on performance, emphasizing environmental sustainability. The study compares the modified Bolomey method and Abrams’ law in designing concretes. Significant differences in cement consumption and subsequent CO2 emissions are revealed. The research advocates for a comprehensive life cycle assessment, considering factors like compressive strength, carbonation resistance, CO2 emissions, and cost. The analysis underscores the importance of evaluating concrete not solely based on strength but also environmental impact. The study concludes that a multicriteria approach, considering the entire life cycle, is essential for sustainable concrete design, addressing durability, environmental concerns, and economic factors. Design/methodology/approach – The study employed a comprehensive design and methodology approach, involving the formulation and testing of 20 mixed concretes with strengths ranging from 25 MPa to 45 MPa. Two distinct design methods, the modified Bolomey method (three equations method) and Abrams’ law, were utilized to calculate concrete compositions. Laboratory experiments were conducted to validate the computational models, and subsequent analyses focused on assessing differences in cement consumption, compressive strength, CO2 emissions, and concrete resistance to carbonation. The research adopted a multidisciplinary perspective, integrating theoretical analysis, laboratory testing, and life cycle assessment to evaluate concrete performance and sustainability.

  • Stymulacyjna funkcja podatku dochodowego
    • Piotr Kasprzak
    2024

    W opracowaniu podjęto próbę opisania i usystematyzowania wiedzy na temat systemu ulg i zwolnień podatkowych stosowanych w Polsce. Autor przedstawia m.in. historię i ewolucję systemu podatkowego w Polsce, począwszy od roku 1989, tłumacząc przy tym rolę państwa. Omówione zostały też trendy i kierunki rozwoju podatków dochodowych. W książce znajdują się informacje na temat istoty i funkcji podatków, ze szczególnym uwzględnieniem stymulacyjnej funkcji podatków. W pracy omówiono również teorię dotyczącą podatków dochodowych od osób fizycznych i prawnych. Autor wymienia i objaśnia stosowane w praktyce ulgi i zwolnienia w podatku dochodowym dla osób fizycznych i prawnych. W opracowaniu przedstawiono analizę pojęć systemu gospodarczego, podatku dochodowego, preferencji podatkowych. Przeprowadzono także analizę sposobów stymulacji zachowań przedsiębiorców w kontekście mechanizmów makroekonomicznych, w tym automatycznych stabilizatorów koniunktury w postaci ulg i zwolnień. Niniejsza książka jest kolejną pozycją, która powstała na podstawie rozprawy doktorskiej autora. Tym razem skupiono się jednak na teoretycznej stronie systemu preferencji podatkowych w systemie gospodarczym.

  • Subjective quality evaluation of 8- and 10-bit MP4-coded video sequences from Netflix
    • Przemysław Falkowski-Gilski
    • Tadeus Uhl
    • Parameshachari Bidare Divakarachari
    2024 Zeszyty Naukowe Akademii Morskiej w Szczecinie

    Recently, many researchers have been intensively conducting quality of service (QoS), quality of experience (QoE), and user experience (UX) studies in the field of video analysis. This paper is intended to make a new, complementary contribution to this field. Currently, streaming platforms are key products in relation to delivering video content online. Most often, they include the MP4 video format, which is most widely utilized among audio-visual codecs. This study involves a group of 38 individuals, aged between 21–35 years old, in a laboratory consisting of 20 iMacs with 4K retina display. The presented signal sequences included content sourced from the Netflix Chimera repository, with 8- and 10-bit depth, available in different resolutions of 270p, 432p, 720p, and 1080p. Tests included a subjective quality evaluation in a 5-step mean opinion score (MOS) scale, focused on the UX aspect. According to the obtained results, content with the lowest and highest resolutions is optimal in 8-bit depth, while movies with intermediate resolutions are better in 10-bit depth. For 8-bit content, the main problem is pixelation, whereas, in the case of 10-bit samples, the main issue is color noise, particularly in the case of the lowest resolution. Many viewers indicated that 10-bit encoding offered lower quality. Moreover, 8-bit movies caused a lower quality of the gradient, presumably due to the smaller range of the available color. However, 8-bit movies in the same situation generate visible stripes on static images in the background, causing a lower quality of the gradient, which is probably due to the smaller range of available colors. The results of the performed experiments may be of particular interest to content creators and distributors, particularly network and cable operators, as well as wireless and wired providers.

  • Substrate Integrated Waveguide-Based Frequency-Tunable Self-Octaplexing Antenna
    • Nrusingha Charan Pradhan
    • Sławomir Kozieł
    • Karthikeyan Sholampettai Subramanian
    2024 AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS

    This communication presents the first-ever substrate integrated waveguide (SIW)-based frequency-tunable self-octaplexing antenna (SOA) for wireless communication. The structure is arranged by implementing eight distinct patches with planar 50-ohm feedlines at the top of the SIW cavity, which realize eight distinct resonant frequencies. Independent tuning of each resonant frequency is achieved by incorporating appropriately allocated pockets in the antenna substrate, which can be filled with solid dielectrics of dierent permittivity. The obtained tuning range is broad, from 4.76 GHz to 9.82 GHz, with the capability of tuning each port individually. Furthermore, the port isolation (for all ports) that is better than 20.5 dB. The proposed antenna has a realized gain of 3.91, 3.2, 4.05, 4.14, 3.8, 3.37, 3.55 and 3.28 dBi when using Rogers RT-6010 for pocket filling. Furthermore, the antenna provides stable radiation characteristics with precise tuning. The proposed device is suitable for various applications, including multi-standard wireless communications, due to its small size, wide tuning range, consistent radiation patterns, and comparable isolation levels.

  • Substrate Integrated Waveguide-Based Ultra-Compact Self-Heptaplexing Antenna for IoT Connectivity
    • Nrusingha Charan Pradhan
    • Sławomir Kozieł
    • Karthikeyan Sholampettai Subramanian
    2024 AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS

    This paper introduces an innovative design of a substrate-integrated waveguide (SIW)-based self-heptaplexing antenna (SHA). The proposed structure is implemented using a combination of circular and rectangular HM-SIW cavities. Furthermore, the antenna contains seven individual patches on top of the SIW cavity to operate at seven distinct frequencies. The microstrip feeding technique has been used to activate seven distinct ports. All patches are excited through 50-ohm feedlines. The antenna operation is elucidated using an equivalent LC model. To demonstrate its operating principles a self-heptaplexing antenna has been designed to work at 2.45, 3, 3.58, 4, 4.45, 5.2, and 5.88 GHz. The measured realized gain of the proposed antenna at the respective bands is 3.2, 3.85, 3.1, 3.245, 4, 2.98, and 4.5 dBi. The isolation exceeds 20 dB over the entire working bands. The EM-simulated and measured characteristics are in good agreement. Although the suggested antenna has been designed for seven ports and lower frequencies, it has a relatively compact size of 0.28 2g. The major advantages of the proposed self-heptaplexing antenna include excellent isolation, an ultra-compact design, and good radiation characteristics. The proposed antenna offers a high degree of flexibility. It allows for independent frequency tuning, which makes it suitable for IoT, wireless communication systems, and diverse sub-6 GHz band applications.

  • Suitability of acoustic power amplifiers as power amplifiers in underwater communication systems
    • Aleksander Schmidt
    • Jan Schmidt
    • Iwona Kochańska
    2024 Full text International Journal of Electronics and Telecommunications

    The paper presents selected acoustic power amplifiers from among those currently available. The results of a series of measurements characterising the amplifiers are presented. The measured amplitude and phase characteristics as a function of frequency for four selected amplifiers are analysed. The spectra of the output signal in the band from 4 kHz to 30 kHz are presented. The usefulness of the selected amplifiers in an underwater communication system is assessed.

  • Sulfur cycle, a new opportunity for nitrogen removal from textile wastewater: A review
    • Shiyi Zhao
    • Hong Chen
    • Jun Sheng
    • Xin Yu
    • Kejia Zeng
    • Dong Cheng
    • Hanyue Wu
    • Ruiting Zhang
    • Xianbao Xu
    • Xiaoming Zou
    • Gang Xue
    2024 Journal of Water Process Engineering

    The problem of nitrogen removal from textile wastewater (TW) has plagued for quite a long time. Traditional biological nitrogen removal technology is limited by the complex water quality characteristics, and high concentration of sulfate (over 5000 mg/L) further aggravates its difficulty. After analyzing source and characteristics of nitrogen and sulfur in TW, using miraculous sulfur cycle caused by the existing sulfate to solve the problem of nitrogen removal seems to be a viable option. This review mainly elaborated the heterotrophic sulfate reduction combining with dye removal, which achieved >90 % sulfate reduction and almost complete dye removal, as well as sulfur-driven autotrophic denitrification, with over 85 % total nitrogen removal. The crucial bacteria and key parameters affecting sulfur cycle were summarized. Based on the characteristics of abundant sulfur and nitrogen in TW, the feasibility of relying on sulfur cycle to achieve nitrogen removal in TW is discussed in detail. Furthermore, the sulfur and nitrogen coupled processes, including sulfate reduction, autotrophic denitrification and nitrification integrated process (SANI) and Sulfammox are reviewed. Technology based on sulfur cycle has the advantages of low energy consumption and low sludge production (reduce by 90 %), as well as cutting greenhouse gas emissions (decrease by 90 %). In the context of carbon peaking and carbon neutrality goals, TW treatment based on sulfur cycle is an energy-saving and carbon-reduction technology with development potential.

  • Summary of the 27th IAHR International Symposium on Ice
    • Wojciech Artichowicz
    • Parisa Radan
    • Tomasz Kolerski
    2024 Full text

    The 27th IAHR International Symposium on Ice, held in Gdańsk, Poland, between 9 and 13 June 2024, gathered 153 scientists and industry professionals from 14 countries. Organized by Gdańsk University of Technology, the event focused on key global ice-related challenges, including ice mechanics, ice-structure interactions, climate change impacts on the cryosphere, and offshore wind development in the Baltic Sea. With 93 papers in the published conference proceedings, the symposium showcased diverse methodologies and multidisciplinary research on sea and river ice dynamics, as well as engineering challenges in cold regions. The event fostered engaging discussions and facilitated collaboration, reinforcing its role as a leading platform for advancing ice research. In this paper this event is summarized.

  • Superconductivity–Electron Count Relationship in Heusler Phases─the Case of LiPd2Si
    • Karolina Górnicka
    • Xin Gui
    • Juan Chamorro
    • Tyrel McQueen
    • Robert J. Cava
    • Tomasz Klimczuk
    • Michał Winiarski
    2024 Full text CHEMISTRY OF MATERIALS

    We report superconductivity in the full Heusler compound LiPd2Si (space group Fm3̅m, No. 225) at a critical temperature of Tc = 1.3 K and a normalized heat capacity jump at Tc, ΔC/γTc = 1.1. The low-temperature isothermal magnetization curves imply type-I superconductivity, as previously observed in LiPd2Ge. We show, based on density functional theory calculations and using the molecular orbital theory approach, that while LiPd2Si and LiPd2Ge share the Pd cubic cage motif that is found in most of the reported Heusler superconductors, they show distinctive features in the electronic structure. This is due to the fact that Li occupies the site which, in other compounds, is filled with an early transition metal or a rare-earth metal. Thus, while a simple valence electron count–property relationship is useful in predicting and tuning Heusler materials, inclusion of the symmetry of interacting frontier orbitals is also necessary for the best understanding.

  • Support Materials of Organic and Inorganic Origin as Platforms for Horseradish Peroxidase Immobilization: Comparison Study for High Stability and Activity Recovery
    • Muhammad Bilal
    • Oliwia Degorska
    • Daria Szada
    • Agnieszka Rybarczyk
    • Agata Zdarta
    • Michał Kaplon
    • Jakub Zdarta
    • Teofil Jesionowski
    2024 Full text MOLECULES

    In the presented study, a variety of hybrid and single nanomaterials of various origins were tested as novel platforms for horseradish peroxidase immobilization. A thorough characterization was performed to establish the suitability of the support materials for immobilization, as well as the activity and stability retention of the biocatalysts, which were analyzed and discussed. The physicochemical characterization of the obtained systems proved successful enzyme deposition on all the presented materials. The immobilization of horseradish peroxidase on all the tested supports occurred with an efficiency above 70%. However, for multi-walled carbon nanotubes and hybrids made of chitosan, magnetic nanoparticles, and selenium ions, it reached up to 90%. For these materials, the immobilization yield exceeded 80%, resulting in high amounts of immobilized enzymes. The produced system showed the same optimal pH and temperature conditions as free enzymes; however, over a wider range of conditions, the immobilized enzymes showed activity of over 50%. Finally, a reusability study and storage stability tests showed that horseradish peroxidase immobilized on a hybrid made of chitosan, magnetic nanoparticles, and selenium ions retained around 80% of its initial activity after 10 repeated catalytic cycles and after 20 days of storage. Of all the tested materials, the most favorable for immobilization was the above-mentioned chitosan-based hybrid material. The selenium additive present in the discussed material gives it supplementary properties that increase the immobilization yield of the enzyme and improve enzyme stability. The obtained results confirm the applicability of these nanomaterials as useful platforms for enzyme immobilization in the contemplation of the structural stability of an enzyme and the high catalytic activity of fabricated biocatalysts.

  • Surface finite viscoelasticity and surface anti-plane waves
    • Victor Eremeev
    2024 Full text INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE

    We introduce the surface viscoelasticity under finite deformations. The theory is straightforward generalization of the Gurtin–Murdoch model to materials with fading memory. Surface viscoelasticity may reflect some surface related creep/stress relaxation phenomena observed at small scales. Discussed model could also describe thin inelastic coatings or thin interfacial layers. The constitutive equations for surface stresses are proposed. As an example we discuss propagation shear (anti-plane) waves in media with surface stresses taking into account viscoelastic effects. Here we analysed surface waves in an elastic half-space with viscoelastic coatings. Dispersion relations were derived.

  • Surprising Radiolytic Stability of 8‑Thiomethyladenine in an Aqueous Solution
    • Magdalena Datta
    • Adrian Szczyrba
    • Magdalena Zdrowowicz
    • Dariusz Wyrzykowski
    • Olga Ciupak
    • Sebastian Demkowicz
    • Farhad Izadi
    • Stephan Denifl
    • Janusz Rak
    2024 Full text JOURNAL OF PHYSICAL CHEMISTRY B

    8-Thiomethyladenine (ASCH3), a potentially radiosensitizing modified nucleobase, has been synthesized in a reaction between 8-thioadenine and methyl iodide. Despite favorable dissociative electron attachment (DEA) characteristics, the radiolysis of an aqueous solution of ASCH3 with a dose of X-ray amounting to as much as 300 Gy leads to no effects. Nevertheless, crossed electron-molecule beam experiments in the gas phase on ASCH3 confirm the theoretical findings regarding the stability of its radical anion, namely, the most abundant reaction channel is related to the dissociation of the S-CH3 bond in the respective anion. Furthermore, electroninduced degradation of ASCH3 has been observed in aprotic acetonitrile, which is strong evidence for the involvement of proton transfer (PT) in stabilizing the radical anion in an aqueous solution. These findings demonstrate that PT in water can be the main player in deciding the radiosensitizing properties of modified nucleobases/nucleosides.

  • Survey of ICT students' views on self-assessment of professional preparation after remote study
    • Marta Szczerska
    • Michał Tomczak
    • Paweł Ziemiański
    • Katarzyna Wajszczyk
    2024 Edukacja Ustawiczna Dorosłych

    The contemporary post-pandemic reality is characterised by an undisputable shift toward remote education and work. The aim of this article is to identify the assessment of ICT evaluation of different forms of study, including desktop, remote and hybrid forms; to find out their preferences towards different forms of education and work, and to determine their sense of self-efficacy in terms of professional tasks undertaken after remote education. A survey method was used and the research sample was based on purposive sampling. The results indicate that, although a hybrid environment is preferred in both educational and professional contexts, the challenge remains to optimise this format in order to improve the quality of education. Nevertheless, the surveyed students feel self-efficacious in their professional activities after remote education.

  • Suspension and process parameters selection for electrophoretic deposition of Mn–Co spinel coating on steel interconnects
    • Omid Ekhlasiosgouei
    • Federico Smeacetto
    • Sebastian Molin
    2024 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY

    Metallic interconnect coatings, consisting of MnCo2O4 spinel, were effectively applied to Crofer 22 APU using the electrophoretic deposition (EPD) method in both H2O: ethanol and pure ethanol solvents. The primary goal of this method was to prevent chromium migration, minimize evaporation, and control the oxidation rate. The study aimed to assess the quality, adhesion, and thickness of the Mn–Co coating, with the objective of achieving a consistent and uniform layer. The results indicated a preference for pure ethanol solvent over H2O: ethanol (40:60 %Vol) for Mn–Co particles. Furthermore, the agglomeration of Mn–Co particles was notably lower (approximately 7 times) in ethanol compared to H2O: ethanol. The morphology and surface roughness of the sintered Mn–Co coating on the alloy were examined using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). A uniform and dense coating was successfully attained using pure ethanol solvent at a solid concentration of 10 g/L, with 0.5 g/L of iodine serving as a disperser. The deposition process, carried out at a voltage of 30V for 20 s, resulted in a coating with a thickness of 7.4 ± 0.3 μm and a surface roughness of 0.75 ± 0.5 μm.

  • Sustainable chemically modified poly(butylene adipate-co-terephthalate)/thermoplastic starch/poly(ε-caprolactone)/cellulose biocomposites: looking at the bulk through the surface
    • Aleksander Hejna
    • Mateusz Barczewski
    • Paulina Kosmela
    • Olga Mysiukiewicz
    • Agnieszka Tercjak
    • Adam Piasecki
    • Mohammad Saeb
    • Marek Szostak
    2024 JOURNAL OF MATERIALS SCIENCE

    Sustainable polymer composites (or biocomposites) based on renewable and green polymers are progressively under development in a technological paradigm shift from “just use more and more” to “convert into value-added products”. Therefore, significant efforts should focus not only on their reduced environmental impact but also on maximizing their performance and broadening their application range. Herein, the bio-based blends based on Mater-Bi bio-plastic and poly(ε-caprolactone), at a weight ratio of 70:30, were developed, followed by the addition of UFC100 cellulose filler to yield sustainable biocomposites. The effects of cellulose chemical modification with three diisocyanates, i.e., hexamethylene diisocyanate (HDI), methylene diphenyl isocyanate (MDI), or toluene diisocyanate (TDI) on the surface properties of biocomposites were evaluated by water contact angle and surface roughness detected by atomic force microscopy (AFM). Biocomposites containing cellulose modified with HDI, MDI, or TDI revealed contact angle values of 93.5°, 97.7°, and 92.4°, respectively, compared to 88.5° for reference blend, indicating an enlarged hydrophobicity window. This action was further confirmed by increased fracture surface roughness and miscibility detected by microscopic observation (scanning electron microscopy (SEM) and AFM). An in-depth oscillatory rheological evaluation has identified MDI, followed by TDI, as the most efficient compatibilizer of the analyzed system. Correspondingly, thermogravimetric analysis and differential scanning calorimetry analyses showed more residue and higher melting temperatures for biocomposites, more promisingly with MDI and TDI modifiers. In conclusion, either incorporation or diisocyanate modification of cellulose affects both surface and bulk properties, providing vital insights into future developments in the field. Proper selection of diisocyanate modifier of cellulose may enable engineering of composites performance.

  • Sustainable energy consumption – Empirical evidence of a household in Poland
    • Ewelina Sokołowska
    • Jerzy Wiśniewski
    2024 Full text Energy Strategy Reviews

    There is an expected increase in the demand for electricity from households in European countries. The outcome of the growing proportion of renewable energy sources in the energy supply mix should result in improved customer awareness regarding their electricity usage. Additionally, they must assume a more proactive role in overseeing their electricity usage. Innovation and pollution management have become crucial catalysts for promoting sustainable economic development and environmental protection. This is a response to the increasing threats posed by climate change. This study addresses this existing research gap in sustainable energy consumption. The research aims to examine the advantages of replacing traditional sources of heating with renewable ones. The empirical case study of households in Poland serves as an illustration of the theoretical foundation. The purpose of the study entails the construction of a multi-equation econometric model describing the mechanisms of electricity consumption in a specific household. The model hypothesis indicates that the model should take the form of a system of interdependent equations. The following will be described: the monthly volume of electricity consumption, the cost of this energy payment (in PLN), and the price per one MWh in a given month. Monthly time series from September 2015 to June 2023 were used. The resulting time series amounted to a count of 94 statistical observations. The results in the form of a multi-level empirical econometric model indicate that the economic, environmental, and social benefits of using renewable sources of heating can make a significant contribution to reducing fossil fuel consumption and CO2 emissions. In the context of growing environmental awareness and the need to reduce greenhouse gas emissions, heat pumps are becoming an increasingly important element in the discussion of the future of heating. Their role in transforming the energy sector in the direction of sustainability is crucial.

  • Sustainable Management of Food Wastes Through Cavitation-Assisted Conversion into Value-Added Products
    • Zahra Askarniya
    • Xun Sun
    • Chongqing Wang
    • Grzegorz Boczkaj
    2024

    More than 30% of worldwide food consumption is thrown out as food wastes causing serious environmental, economic, and social problems. Therefore, it is required to develop sustainable food waste management methods leading to an enhancement in social and economic benefits and mitigation of environmental impacts. Anaerobic digestion can be regarded as one of those effective methods that can be employed for the conversion of food waste to value-added products. Food wastes are normally resistant towards hydrolysis (the first stage of anaerobic digestion), leading to a reduction in the formation of desired products. Cavitation is one of the useful pretreatment methods that can mitigate this problem and also increase mass transfer, which is a severe barrier to the reaction producing biodiesel (transesterification), leading to high rates of hydrolysis and transesterification. Cavitation is the formation, growth, and collapse of bubbles formed in the solution. Considering the subsequent effect of the collapse of generated bubbles (ability to disintegrate solid material, turbulence, high temperature and pressure, and radical formation), cavitation can be considered an efficient technique for minimizing the time and optimizing the generation of valuable products from food wastes. This technology can cause microbes to easily access substrates, resulting in an enhancement in microbial growth and the formation of products. Additionally, it can increase mass transfer between reactants, decreasing the time required in transesterification for producing biodiesel.

  • Symbolic multibody models for digital-twin applications
    • Nicolas Docquier
    • Krzysztof Lipiński
    • Olivier Lantsoght
    • Sebastien Timmermans
    • Paul Fisette
    2024 MULTIBODY SYSTEM DYNAMICS

    Symbolic generation of multibody systems equations of motion appeared in the 1980s. In addition to their computational advantage over their numerical counterparts, symbolic models can be very easily and straightforwardly interfaced with a wide range of software environments and hardware devices. These two features place this approach in a pole position to participate and intervene in the design of digital twins for systems such as vehicles, manipulators, walking robots or haptic devices. In this context, the first goal of this paper is to highlight the interest of symbolically generated multibody models – at the root of the ROBOTRAN program – in the form of a standalone set of equations calculating the dynamic model of multibody systems, for use as a computational component within a Digital-Twin-type process. The next goal is to embed realistic and complex multibody models within processes or devices whose functioning requires a synchronized real-time computation – or analysis – of their motion. An implementation (i) on specific hardware and (ii) on two extremely opposite but revealing applications (namely a railway vehicle and a digital piano) are presented to highlight the usefulness of symbolic models for the development of current and future multibody-based digital twins.

  • Synergism of floated paperboard sludge cake /sewage sludge for maximizing biomethane yield and biochar recovery from digestate: A step towards circular economy
    • Rania H. Hafez
    • Ahmed Tawfik
    • Gamal K. Hassan
    • Magdy Zahran
    • Ahmed A. Younes
    • Aleksandra Ziembińska-Buczyńska
    • Filip Gamoń
    • Mahmoud Nasr
    2024 CHEMOSPHERE

    Anaerobic digestion of floated paperboard sludge (PS) cake suffers from volatile fatty acids (VFAs) accumulation, nutrient unbalanced condition, and generation of digestate with a risk of secondary pollution. To overcome these drawbacks, sewage sludge (SS) was added to PS cake for biogas recovery improvement under a co-digestion process followed by the thermal treatment of solid fraction of digestate for biochar production. Batch experimental assays were conducted at different SS:PS mixing ratios of 70:30, 50:50, 30:70, and 20:80 (w/w), and their anaerobic co-digestion performances were compared to the mono-digestion systems at 35±0.2 °C for 45 days. The highest methane yield (MY) of 241.68±14.81 mL/g CODremoved was obtained at the optimum SS:PS ratio of 50:50 (w/w). This experimental condition was accompanied by protein, carbohydrate, and VFA conversion efficiencies of 47.3±3.2%, 46.8±3.2%, and 56.3±3.8%, respectively. The synergistic effect of SS and PS cake encouraged the dominance of Bacteroidota (23.19%), Proteobacteria (49.65%), Patescibacteria (8.12%), and Acidovorax (12.60%) responsible for hydrolyzing the complex organic compounds and converting the VFAs into biomethane. Further, the solid fraction of digestate was subjected to thermal treatment at a temperature of 500 °C for 2.0 h, under an oxygen-limited condition. The obtained biochar had a yield of 0.48 g/g dry digestate, and its oxygen-to-carbon (O/C), carbon-to-nitrogen (C/N), and carbon-to-phosphorous (C/P) ratios were 0.55, 10.23, and 16.42, respectively. A combined anaerobic co-digestion/pyrolysis system (capacity 50 m3/d) was designed based on the COD mass balance experimental data and biogenic CO2 market price of 22 USD/ton. This project could earn profits from biogas (12565 USD/yr), biochar (6641 USD/yr), carbon credit (8014 USD/yr), and COD shadow price (6932 USD/yr). The proposed project could maintain a payback period of 6.60 yr. However, further studies are required to determine the associated life cycle cost model that is useful to validate the batch experiment assumptions.

  • Synergistic effects of a swirl generator and MXene/ water nanofluids used in a heat exchanger pipe of a negative CO2 emission gas power plant
    • Milad Amiri
    • Paweł Ziółkowski
    • Dariusz Mikielewicz
    2024 NUMERICAL HEAT TRANSFER PART A-APPLICATIONS

    focus on optimizing heat exchangers contributes to improved temperature control mechanisms, ensuring the sustainable operation of innovative power plants working towards negative CO2 emissions. In the realm of oxy-combustion within Negative CO2 Emission Power Plants (nCO2PP), the temperature of combustion products surpasses 3000 (K). Addressing this challenge, the imperative arises to reduce these elevated temperatures to a manageable 1100(°C). This critical cooling process is achieved through the injection of water, facilitated by the implementation of heat exchangers. The study delves into the optimization of heat transfer within the heat exchanger pipe, specifically tailored for the context of a Negative CO2 Emission Power Plant. Employing a numerical simulation, the investigation explores the impact of vortex generator geometry, vane angles, single and dual propeller-type swirl generators, and the integration of a novel class of fluid, MXene/water nanofluid. Initially, the study scrutinizes propeller-type geometry at vane angles spanning from 15 to 60 degrees. The enhanced swirl flow associated with lower vane angles leads to improved fluid mixing, fostering more effective heat transfer. Results showed that the 15-degree vane angle, with a wider circumferential coverage, may result in increased wall contact, influencing heat transfer efficiency. Subsequently, at Re=6000, incremental rates of the Nusselt number ((〖Nu〗_n-〖Nu〗_s)/〖Nu〗_s %), for θ=15, 30, 45, and 60 degrees are 175.1%, 108.8%, 90.7%, and 40.3%, respectively. Also, the increment rates of Friction Factor (f_n/f_s ) for aforementioned vane angle are 38.48%, 9.26%, 4.08%, and 2.42%, respectively. In addition, for ∅_MXene=0.5 %, the Nusselt number experiences considerable increments of 22.94%, 24.17%, 24.70%, and 24.707% at Reynolds numbers of 6000, 12000, 18000, and 24000, respectively, compared to pure water, emphasizing the potential of MXene to enhance heat transfer efficiency.

  • Synteza i charakterystyka „zielonych” mieszanin polimerowych na bazie biopochodnego termoplastycznego poliuretanu i octanomaślanu celulozy
    • Ewa Głowińska
    • Joanna Smorawska
    • Joanna Niesiobędzka
    • Julia Grocholska
    • Janusz Datta
    2024 Full text Przemysł Chemiczny

    Otrzymano mieszaniny polimerowe z biopochodnego termoplastycznego poliuretanu (TPU) i dostępnego handlowo octanomaślanu celulozy (CAB), stosowanego w ilości 0–20%. TPU syntezowano metodą prepolimerową z wykorzystaniem biopoliolu, glikolu 1,3-propylenowego i diizocyjanianu heksametylenu. Materiały poddano analizie pod kątem struktury chemicznej (FTIR), właściwości termicznych (TGA, DSC) i właściwości termomechanicznych (DMTA).

  • Synteza małocząsteczkowych pochodnych 2-pirydonu wykazujących właściwości przeciwnowotworowe oraz przeciwbakteryjne
    • Małgorzata Ryczkowska
    2024 Full text

    Tematyka i cel badawczy niniejszej rozprawy doktorskiej dotyczy syntezy chemicznej związków heterocyklicznych z grupy 2-pirydonu wykazujących potencjał przeciwbakteryjny oraz przeciwnowotworowy. W części teoretycznej podjęto tematykę znanych fluorochinolonów oraz chinolonów wykazujących aktywność przeciwnowotworową. Dodatkowo przedstawiono nowe metody syntezy chinolonów niewymagające stosowania katalizatorów metali przejściowych oraz opublikowane na przestrzeni ostatnich 15 lat. W części badań własnych przedstawiono syntezę arylokarbamoilowych pochodnych 4-fenylo-5,6,7,8-tetrahydrochinolin-2(1H)-onu oraz badania mające na celu poznanie mechanizmu demetylowania podczas acylowania 2-metoksy-5,6,7,8-tetrahydrochinolin-8-olu izocyjanianami fenylowymi. Przedstawiono w niej również syntezę 4-fenylo-5,6,7,8-tetrahydrochinolin-2(1H)-onów modyfikowanych w pozycji 3 podstawnikami typu benzylowego. Ponadto opisano nową metodę syntezy typu „one-pot” rdzeni 4-fenylo-5,6,7,8-tetrahydrochinolin-2(1H)-onu, zbadano mechanizm powstawania trójcyklicznych pochodnych oraz przedstawiono funkcjonalizację pilicydu grupami o charakterze hydrofilowym. W części eksperymentalnej przedstawiono procedury syntezy oraz analizę spektralną wszystkich otrzymanych związków.

  • Synthesis and biological evaluation of novel 3,6- amide and thioamide substituted- 2,3,4,9-tetrahydro-1H-carbazoles for anti-cancer activity
    • Alicja Trocka
    • Anoop Kallingal
    • Natalia Maciejewska
    • Narajczyk Magdalena
    • Anna Hromova
    • Sławomir Makowiec
    2024 Full text EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY

    Herein, we report the synthesis of new compounds with demonstrated anticancer properties based on the 2,3,4,9- tetrahydro-1H-carbazole scaffold. The Fischer indolization method was used to close the heterocyclic motif. The synthesis method’s scope and limitations were thoroughly assessed through a series of experiments. Biological assays revealed that two thioamide compounds exhibited significant anticancer activity against MCF-7, HTC116, and A596 cell lines. Comprehensive in vitro profiling included evaluation of cell cytotoxicity, morphological alterations, colony formation and cell adhesion in 3D cultures, cell cycle analysis, DNA damage induction, impact on mitochondria, and apoptosis. Ex ovo studies further demonstrated these compounds’ potential to inhibit angiogenic processes. Our results indicate that the newly developed compounds activate processes leading to DNA damage and disruption of mitochondrial function.

  • Synthesis and characterization of MoS2-carbon based materials for enhanced energy storage applications
    • Mariusz Szkoda
    • Anna Ilnicka
    • Konrad Trzciński
    • Zuzanna Zarach
    • Daria Roda
    • Andrzej Nowak
    2024 Scientific Reports

    The article delves into the synthesis and characterization of MoS2-carbon-based materials, holding promise for applications in supercapacitors and ion batteries. The synthesis process entails the preparation of MoS2 and its carbon hybrids through exfoliation, hydrothermal treatment, and subsequent pyrolysis. Various analytical techniques were employed to comprehensively examine the structural, compositional, and morphological properties of the resulting materials. The article explores the electrochemical performance of these electrode materials in supercapacitors and ion batteries (LiB, SiB, KiB). Electrochemical measurements were conducted in aqueous electrolyte for supercapacitors and various aprotic electrolytes for ion batteries. Results highlight the impact of the synthesis process on electrochemical performance, emphasizing factors such as capacitance, rate capability, and charge/discharge cycle performance. Hydrothermally treated MoS2-carbon exhibited a specific capacitance of approximately 150 F g-1 in supercapacitors, attributed to its high surface area and efficient charge storage mechanisms. Additionally, for Li-ion battery materials without hydrothermal treatment showed impressive capacity retention of around 88% after 500 charge-discharge cycles, starting with an initial specific capacity of about 920 mAh/g. Long-term stability was demonstrated in both supercapacitors and lithium-ion batteries, with minimal capacitance degradation even after extensive charge-discharge cycles. This research underscores the potential of MoS2-based materials as effective energy storage solutions.

  • Synthesis and physical properties of Sm2PdGe3 in a context of RE2PdGe3 family
    • Leszek Litzbarski
    • Marcin Łapiński
    • Tomasz Klimczuk
    • Michał Winiarski
    2024 JOURNAL OF SOLID STATE CHEMISTRY

    In this study, we present the crystallographic and magnetic characterization of a new intermetallic compound Sm2PdGe3, which was synthetized by a two stage method employing an eutectic alloy. The investigations carried out exhibited, that Sm2PdGe3 crystallize in AlB2-type structure with lattice parameters a = 4.2189(1) Å and c = 4.1031(2) Å. This compound can be classified as a cluster-glass with a spin freezing temperature Tf = 10.5 K. Furthermore, there were carried out the analysis of the role of the rare earth (RE) elements on the structural parameters of RE2PdGe3 and draw a correlation between the RE radius and the unit cell parameters. We show that a deviation from the ideal 1:3 Pd:Ge ratio is necessary to synthesize RE2PdGe3 with smaller RE elements.