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  • High Isolation Metamaterial-based Dual-band MIMO Antenna for 5G Millimeter-wave Applications
    • Bashar Esmail
    • Sławomir Kozieł
    2023 AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS

    This article presents a high-isolation metamaterial-based dual-band multiple-input multiple-output (MIMO) antenna for 5G millimeter-wave communication networks. The proposed antenna is a pentagon-shaped monopole that provides a dual-band response with a wide operating bandwidth at 5G 28/28 bands. The antenna is printed on 0.508-mm-thick Rogers RT5880 substrate of relative permittivity ɛr =2.2. It exhibits a small physical size of 5.5 × 5.4 × 0.508 mm3, excluding the feeding line. The MIMO system is constructed of two symmetric radiating elements arranged adjacently with the mutual coupling of −18.5 dB at both resonant frequencies. The dual-band metamaterial is designed and placed between the two radiators to reduce the mutual coupling. Embedding a 3×1 metamaterial array enhances the isolation to −39 dB and −38 dB at 28 GHz and 38 GHz, respectively. The proposed system is capable of covering both 28/28 5G bands and has the merits of broad bandwidth, low profile, high gain ( > 5 dB), improved isolation (−38 dB), low envelope correlation coefficient (ECC) (< 0.0001) and channel capacity loss (CCL) (< 0.05), and high diversity gain (DG) (> 9.99 dB). The system performance is verified experimentally with good agreement between the simulated and measured data. These properties demonstrate the system applicability for 5G millimeter-wave communication networks.

  • High-Efficacy Global Optimization of Antenna Structures by Means of Simplex-Based Predictors
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    2023 Pełny tekst Scientific Reports

    Design of modern antenna systems has become highly dependent on computational tools, especially full-wave electromagnetic (EM) simulation models. EM analysis is capable of yielding accurate representation of antenna characteristics at the expense of considerable evaluation time. Consequently, execution of simulation-driven design procedures (optimization, statistical analysis, multi-criterial design) is severely hindered by the accumulated cost of multiple antenna evaluations. This problem is especially pronounced in the case of global search, frequently performed using nature-inspired algorithms, known for poor computational efficiency. At the same time, global optimization is often required, either due to multimodality of the design task or the lack of sufficiently good starting point. A workaround is to combine metaheuristics with surrogate modeling methods, yet a construction of reliable metamodels over broad ranges of antenna parameters is challenging. This work introduces a novel procedure for global optimization of antenna structures. Our methodology involves a simplex-based automated search performed at the level of approximated operating and performance figures of the structure at hand. The presented approach capitalizes on weakly-nonlinear dependence between the operating figures and antenna geometry parameters, as well as computationally cheap design updates, only requiring a single EM analysis per iteration. Formal convergence of the algorithm is guaranteed by implementing the automated decision-making procedure for reducing the simplex size upon detecting the lack of objective function improvement. The global optimization stage is succeeded by gradient-based parameter refinement. The proposed procedure has been validated using four microstrip antenna structures. Multiple independent runs and statistical analysis of the results have been carried out in order to corroborate global search capability. Satisfactory outcome obtained for all instances, and low average computational cost of only 120 EM antenna simulations, demonstrate superior efficacy of our algorithm, also in comparison with both local optimizers and nature-inspired procedures.

  • Highly Occupied Surface States at Deuterium-Grown Boron-Doped Diamond Interfaces for Efficient Photoelectrochemistry
    • Michał Sobaszek
    • Maria Brzhezinskay
    • Adrian Olejnik
    • Vincent Mortet
    • Mahebub Alam
    • Sawczak Mirosław
    • Mateusz Ficek
    • Maria Gazda
    • Zdenek Weiss
    • Robert Bogdanowicz
    2023 Pełny tekst SMALL

    Polycrystalline boron-doped diamond is a promising material for high-power aqueous electrochemical applications in bioanalytics, catalysis, and energy storage. The chemical vapor deposition (CVD) process of diamond forma-tion and doping is totally diversified by using high kinetic energies of deu-terium substituting habitually applied hydrogen. The high concentration of deuterium in plasma induces atomic arrangements and steric hindrance during synthesis reactions, which in consequence leads to a preferential (111) texture and more effective boron incorporation into the lattice, reaching a one order of magnitude higher density of charge carriers. This provides the surface reconstruction impacting surficial populations of CC dimers, CH, CO groups, and COOH termination along with enhanced kinetics of their abstraction, as revealed by high-resolution core-level spectroscopies. A series of local densities of states were computed, showing a rich set of highly occupied and localized surface states for samples deposited in deuterium, negating the connotations of band bending. The introduction of enhanced incorporation of boron into (111) facet of diamond leads to the manifestation of surface electronic states below the Fermi level and above the bulk valence band edge. This unique electronic band structure affects the charge transfer kinetics, electron affinity, and diffusion field geometry critical for efficient electrolysis, electrocatalysis, and photoelectrochemistry

  • Highly stable CsFAPbIBr perovskite solar cells with dominant bulk recombination at real operating temperatures
    • Beatriz Romero
    • Silvia Delgado
    • Damian Głowienka
    • Cheng-Tsung Chang
    • Gonzalo Del Pozo
    • Belén Arredondo
    • Diego Martín-Martín
    • Pedro Contreras
    • Yulia Galagan
    2023 Pełny tekst Sustainable Energy & Fuels

    Mixed-cation mixed-halide perovskite solar cells have been characterized in DC at different temperatures (from −20 °C up to 50 °C) and the time evolution of the device efficiency has been assessed using different degradation protocols (indoors and outdoors). The completely planar p–i–n structure is ITO/CuNiOx/PTAA/CsFAPbIBr/PCBM/PEI/Ag. Pristine current–voltage characteristics barely show hysteresis, at any temperature. Open circuit voltage decreases with temperature at a rate of −1.5 mV °C−1, and the obtained PCE temperature coefficient is lower than −0.001% K−1, which is an outstanding value for this emerging photovoltaic technology. Cells have been degraded under different protocols: indoors using different light/dark cycles and outdoors in a high temperature and high irradiation location. Cells show no significant decrease of the efficiency after more than 350 h of indoor light cycling and the estimated T80 obtained for the sample degraded outdoors under high irradiation and high temperature conditions is ∼15 days.

  • Highly-Miniaturized Self-Quadruplexing Antenna Based on Substrate-Integrated Rectangular Cavity
    • Rusan Kumar Barik
    • Sławomir Kozieł
    2023 IEEE Antennas and Wireless Propagation Letters

    This paper introduces a novel self-quadruplexing antenna (SQA) architecture using a substrate-integrated rectangular cavity (SIRC) for compact size, wide-frequency re-designability, and high isolation responses. The proposed SQA is developed by engraving two U-shaped slots (USSs) on the top conductor of the SIRC. The USSs are excited by employing four microstrip feedlines to achieve self-quadruplexing antenna characteristics. The operating frequencies can be tuned independently according to the assumed targets, with a wide tuning range from 2.3 GHz to 7 GHz. The dimensions of USSs are meticulously chosen to achieve high isolation and compact size. An equivalent circuit is suggested to validate the proposed SQA. Finally, the SQA operating at 2.33, 2.96, 5.43, and 6.15 GHz is fabricated and validated. As compared to the earlier SQAs, the proposed antenna offers competitive performance with a compact size of 0.124λ2 (45.6% smaller than the most compact SQA reported in the literature), high isolation of 32.5 dB, and a wide tunable range from 2.3 GHz to 7 GHz. Its measured gain is 4.31, 3.39, 6.12, and 4.34dBi at 2.33, 2.96, 5.43, and 6.15 GHz, respectively.

  • High-Resolution, Broad-Range Detection Setup for Polarimetric Optical Fiber Sensors
    • Paweł Wierzba
    2023 Pełny tekst Applied Sciences-Basel

    A common-path polarization interferometer using a Wollaston prism and an area detector for the measurement of retardation or optical path difference is presented. Employing a moderate-resolution 1280 by 1024 pixel monochrome camera, it offers a measurement range of approximately 780 radians at 830 nm and 1350 radians at 515 nm while maintaining a high measurement resolution. Retardation introduced by a zero-order waveplate or a Soleil–Babinet compensator was measured to evaluate the performance of the interferometer. Based on the presented measurement results, the resolution of the measurement is estimated to be better than 0.002 rad

  • High-temperature Corrosion of ~ 30 Pct Porous FeCr Stainless Steels in Air: Long-Term Evaluation Up to Breakaway
    • Damian Koszelow
    • Małgorzata Makowska
    • Agnieszka Drewniak
    • Grzegorz Cempura
    • Piotr Jasiński
    • Sebastian Molin
    2023 Pełny tekst METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE

    In this work, a long-term (up to 6000 hours) corrosion evaluation of three porous (~ 30 pct of initial porosity) ferritic iron-chromium alloys with different Cr contents (20, 22, and 27 wt pct of Cr) was carried out at 600 C, 700 C, 800 C, and 900 C in air. Mass gain measurements and SEM analyses revealed that at temperatures above 600 C, all alloys exhibit breakaway corrosion, whereas at 600 C, none of the alloys were heavily oxidized even after 6000 hours. Based on the results, the diffusion character of the corrosion of porous chromia-forming alloys was identified. The microstructure changes at high temperatures in porous alloys containing 22 wt pct of Cr were determined in detail by transmission electron microscopy. The proposed prediction model indicated that the lifetimes of the Fe20Cr and Fe22Cr alloys were determined as 1250 hours (± 535 hours) and 1460 hours (± 640 hours), respectively. It is in agreement with the long-term oxidation experiment. For the Fe27Cr alloy, the deviation between predicted and observed lifetimes occurs. The proposed model allows for qualitative estimation of the porous alloys’ lifetime with experimentally validated accuracy.

  • High-Temperature Tensile Behaviour of GTAW Joints of P92 Steel and Alloy 617 for Two Different Fillers
    • Amit Kumar
    • Sachin Sirohi
    • Shailesh M. Pandey
    • Pradeep Kumar
    • Dariusz Fydrych
    • Chandan Pandey
    2023 Pełny tekst Materials

    This study explores the high-temperature (HT) tensile rupture characteristics of a dissimilar gas-tungsten-arc-welded (GTAW) joint between P92 steel and Alloy 617, fabricated using ER62SB9 and ERNiCrCoMo-1 fillers. The high-temperature tensile tests were performed at elevated temperatures of 550 ◦C and 650 ◦C. An optical microscope (OM) and a field emission scanning electron microscope (FESEM) were utilized to characterize the joint. The high-temperature test results indicated that the specimen failed at the P92 base metal/intercritical heat-affected zone (ICHAZ) rather than the weld metal for the ERNiCrCoMo-1(IN617) filler. This finding confirmed the suitability of the joint for use in the Indian advanced ultra-supercritical (A-USC) program. The fracture surface morphology and presence of precipitates were analysed using an SEM equipped with energy dispersive spectroscopy (EDS). The appearance of the dimples and voids confirmed that both welded fillers underwent ductile–dominant fracture. EDS analysis revealed the presence of Cr-rich M23C6 phases, which was confirmed on the fracture surface of the ER62S-B9 weld (P92-weld). The hardness plot was analysed both in the as-welded condition and after the fracture.

  • Historia kształtowania polskiej terminologii elektrotechnicznej
    • Dariusz Świsulski
    2023 Pełny tekst Przegląd Elektrotechniczny

    Przedstawiono prace nad kształtowaniem języka w zakresie elektrotechniki. Prace te zaczynają od początków wykorzystania elektryczności pod koniec XIX wieku, kończą na dostosowaniu do norm europejskich i tworzeniu słownika internetowego. Omówiono wydarzenia związane z organizacją słowotwórstwa oraz najważniejsze publikacji zawierające słownictwo obowiązujące w danym okresie.

  • Homogeneous nucleation rate of methane hydrate formation under experimental conditions from seeding simulations
    • Joanna Grabowska
    • Samuel Blazquez
    • Eduardo Sanz
    • E. G. Noya
    • Iván M. Zerón
    • Jesús Algaba
    • José Manuel Míguez
    • Felipe J. Blas
    • Carlos Vega
    2023 Pełny tekst JOURNAL OF CHEMICAL PHYSICS

    In this work, we shall estimate via computer simulations the homogeneous nucleation rate for the methane hydrate at 400 bars for a supercooling of about 35 K. The TIP4P/ICE model and a Lennard-Jones center were used for water and methane, respectively. To estimate the nucleation rate, the seeding technique was employed. Clusters of the methane hydrate of different sizes were inserted into the aqueous phase of a two-phase gas–liquid equilibrium system at 260 K and 400 bars. Using these systems, we determined the size at which the cluster of the hydrate is critical (i.e., it has 50% probability of either growing or melting). Since nucleation rates estimated from the seeding technique are sensitive to the choice of the order parameter used to determine the size of the cluster of the solid, we considered several possibilities. We performed brute force simulations of an aqueous solution of methane in water in which the concentration of methane was several times higher than the equilibrium concentration (i.e., the solution was supersaturated). From brute force runs, we infer the value of the nucleation rate for this system rigorously. Subsequently, seeding runs were carried out for this system, and it was found that only two of the considered order parameters were able to reproduce the value of the nucleation rate obtained from brute force simulations. By using these two order parameters, we estimated the nucleation rate under experimental conditions (400 bars and 260 K) to be of the order of log10 (J/(m3s)) = −7(5).

  • Hopf bifurcation in time‐delayed gene expression model with dimers
    • Agnieszka Bartłomiejczyk
    • Marek Bodnar
    2023 MATHEMATICAL METHODS IN THE APPLIED SCIENCES

    We study a mathematical model of gene transcription and protein synthesis with negative feedback. We consider a system of equations taking into account the formation of dimers (i.e., complex formed by two protein monomers), the way in which dimers bind to DNA and time delay in translation process. For the model consisting of three ordinary differential equations with time delay, we derive conditions for stability of the positive steady state and for the existence of the Hopf bifurcation. We check the influence of delay in transcription process on the model dynamics, and we formulate conditions determining the type of the Hopf bifurcation and stability of arising limit cycle.

  • HOSPICJUM CARITAS/OLSZTYN
    • Agnieszka Błażko
    2023 Pełny tekst Architektura-Murator

    Obiekt hospicjum stacjonarnego Caritas dla dzieci w Olsztynie wzbudza pozytywne uczucia nie tylko u mieszkańców miasta, lecz także profesjonalistów. To miejsce całodobowej intensywnej opieki stacjonarnej w ostatnich miesiącach życia dziecka, ale też przestrzeń, w którym rodzina uzyskuje wsparcie i uczy się postępowania w tej trudnej sytuacji. To funkcja bez wątpienia niezwykle potrzebna w wymiarze społecznym, ale jednocześnie działanie bardzo ważne w aspektach architektonicznym i przestrzennym. Odrestaurowany i rozbudowany na potrzeby hospicjum budynek, zlokalizowany w dawnym zespole Starych Koszar Strzelców (1883-1884) przy ulicy Kromera 5 i 7, został oddany do użytku w czerwcu 2022 roku. Autorom przedsięwzięcia udało się nie tylko przywrócić rangę zdegradowanemu obiektowi przez odzyskanie substancji zabytkowej i kulturalne jej uzupełnienie z szacunkiem dla czynnika czasu, ale też uporządkować fragment przestrzeni miasta. W trudnym zagadnieniu integrowania części rozbudowanej z odrestaurowanym obiektem zabytkowym na szczególną uwagę zasługuje mistrzowskie, na pozór rzemieślnicze, a jednocześnie nowoczesne operowanie detalem. Elewację nowej części zrealizowano, wykorzystując dwa rodzaje komponentów: indywidualnie zaprojektowane na potrzeby tego obiektu kształtki ceramiczne i stanowiące szkielet do ich mocowania czarne elementy stalowe o przekroju prostokątnym. Nowoczesne w wyrazie, surowe kształtki wchodzą w dialog z odzyskaną, częściowo uzupełnioną okładziną ceglaną budynku koszar. Dzięki stworzeniu kilku planów w strukturze fasady projektantom udało się uzyskać ciekawe rytmy, poziome i pionowe podziały elewacji rozbudowanej części, a także atrakcyjną grę światła i cienia.

  • How acidic amino acid residues facilitate DNA target site selection
    • Kazi Hossain
    • Mateusz Kogut
    • Joanna Słabońska
    • Subrahmanyam Sappati
    • Miłosz Wieczór
    • Jacek Czub
    2023 Pełny tekst PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA

    Despite the negative charge of the DNA backbone, acidic residues (Asp/Glu) commonly participate in the base readout, with a strong preference for cytosine. In fact, in the solved DNA/protein structures, cytosine is recognized almost exclusively by Asp/Glu through a direct hydrogen bond, while at the same time, adenine, regardless of its amino group, shows no propensity for Asp/Glu. Here, we analyzed the contribution of Asp/Glu to sequence-specific DNA binding using classical and ab initio simulations of selected transcription factors and found that it is governed by a fine balance between the repulsion from backbone phosphates and attractive interactions with cytosine. Specifically, Asp/Glu lower the affinity for noncytosine sites and thus act as negative selectors preventing off-target binding. At cytosine-containing sites, the favorable contribution does not merely rely on the formation of a single H-bond but usually requires the presence of positive potential generated by multiple cytosines, consistently with the observed excess of cytosine in the target sites. Finally, we show that the preference of Asp/Glu for cytosine over adenine is a result of the repulsion from the adenine imidazole ring and a tendency of purine–purine dinucleotides to adopt the BII conformation.

  • How Can We Identify Electrophysiological iEEG Activities Associated with Cognitive Functions?
    • Michał Kucewicz
    • Gregory A. Worrell
    • Krishnakant Saboo
    2023

    Electrophysiological activities of the brain are engaged in its various functions and give rise to a wide spectrum of low and high frequency oscillations in the intracranial EEG (iEEG) signals, commonly known as the brain waves. The iEEG spectral activities are distributed across networks of cortical and subcortical areas arranged into hierarchical processing streams. It remains a major challenge to identify these activities in the frequency spectrum, time, and anatomical space, especially during memory and higher-order cognitive functions. Traditionally, this has been done manually by visual inspection of the activities induced in iEEG signals, or semiautomatically by supervised signal detections of computer algorithms. Emerging machine-learning and artificial intelligence tools enable more automated, efficient, objective, and accurate solutions than the traditional expert review. In this chapter, we showcase example applications of features and methods to study cognitive functions and to identify brain areas for therapeutic interventions, including electrical stimulation. These resulted in unexpected findings about the spatiotemporal organization of memory processing and the effects of stimulating the brain. Thus identified iEEG activities offer electrophysiological biomarkers for mapping not only cognitive but also other sensorimotor functions, and are ideally suited for new brain-computer interface approaches to intelligently modulate specific neural processes.

  • How do personality traits influence Open Government Data (OGD) adoption and usage? Investigating the indirect and moderating effects
    • Nina Rizun
    • Charalampos Harris Alexopoulos
    • Stuti Saxena
    • Fernando Kleiman
    • Ricardo Matheus
    2023 Pełny tekst

    Open Government Data (OGD) research has focused for a long on the adoption and usage from the perspectives of users across different contexts. The underlying rationale for this specific focus is that OGD initiatives are undertaken to further citizen engagement with OGD for value generation and innovation purposes. Conceding that usage propensity is different across individuals, it is important to understand the influence of personality traits vis-à-vis OGD adoption and usage. Given that OGD has been regarded as a sophisticated “technology” and the role of personality traits has been considered as important in the adoption and usage of “technologies” in general, therefore, the present study contributes to the extant OGD-focused literature from a novel dimension. The study invokes the adapted model of the Unified Theory of Technology Adoption and Use (UTAUT) alongside the HEXACO-100 inventory constructs for studying the relationships between the constructs with a sample of 530 respondents. The results demonstrate that higher user Openness to Experience contributes to their higher Effort and Performance Expectancy; exposure to Social Influence; an increased level of Trust; and a more positive perception of Facilitating Conditions and Information Quality. Agreeable people are more likely to voluntarily use OGD. An individual's conscientiousness improves their perception of factors related to OGD quality. Excessive emotionality leads to a more critical perception of systems and information quality issues. Our findings also attest to the moderating impact of Honesty-Humility across Information Quality-Behavioral Intention positively; Extraversion across Information Quality-Behavioral Intention negatively and Extraversion across Trust-Behavioral Intention positively. Honesty turns out to be important for considering Information Quality vis-à-vis OGD adoption and usage but whilst extroverts are concerned about Information Quality, i.e. flawless information retrieval via OGD sources, Introverts are concerned about OGD trustworthiness, i.e. credible OGD for its adoption and usage and Extroverts find the OGD reliable and credible. With pointers for further research across the personality traits-OGD adoption and usage theme, the study closes with practitioner implications.

  • How do responsible universities perceive their social engagement? In search of signs of Creating Shared Value by the University
    • Elżbieta Karwowska
    2023 Pełny tekst Journal of Modern Science

    Objectives: University social responsibility still lacks legitimisation and is perceived as a burden that hinders academics from doing research and teaching. Creating Shared Value by the University may serve as a tool to motivate universities to engage in initiatives for society, as this is beneficial for both parties. Yet, some researchers perceive the creation of economic value as inappropriate for academia. Thus, it was interesting to examine how the world's best universities elaborate on this matter. Material and methods: A thematic analysis of textual data published online by universities in the top 30 in THE Impact Rankings 2022 has been conducted to determine if they create shared value and what benefits they create or expect. Results: Signs of indirect Creating Shared Value by the University were observed in the dataset. Some universities create social and economic benefits from the same initiatives, mainly strategic. The observed benefits are both intangible and tangible, but most are related to increasing brand value: receiving recognition and awards, building reputation, strengthening competitive advantage, boosting brand attractiveness, and employer branding. Universities modestly mention that they gain tangible benefits, such as an expansion of research funds, and earned or passive income, which may point out that such values are not perceived as suitable in an academic context yet. Conclusions: The results shed new light on the perception of creating economic value in academia, indicating that CSVU could be a legitimate tool to develop the theory and practice of USR. Still, results suggest that any CSVU framework should focus primarily on intangible benefits.

  • How pesticides affect neonates? - Exposure, health implications and determination of metabolites
    • María José Santoyo Treviño
    • Marina Pereira-Coelho
    • Andrea Guadalupe Rodríguez López
    • Sergio Zarazúa
    • Luiz Augusto dos Santos Madureira
    • Tomasz Majchrzak
    • Justyna Płotka-Wasylka
    2023 Pełny tekst SCIENCE OF THE TOTAL ENVIRONMENT

    This review covers key information related to the effects of pesticides on fetal and child health. All humans are exposed to environmental toxicants, however child's health, due to their high vulnerability, should be of special concern. They are continuously exposed to environmental xenobiotics including a wide variety of pesticides, and other pollutants. These compounds can enter the child's body through various routes, both during fetal life, in the first days of life with breast milk, as well as during environmental exposure in later years of life. Consequently, in the body, some of them are metabolized and excreted with urine or faces, while others accumulate in tissues causing toxic effects. This review will provide information on the types of pesticides, their pathways of uptake and metabolism in children's bodies. Determination of the impact of them on children's organism performance is possible through effective identification of these compounds and their metabolites in children's tissues and biofluids. Therefore, the main procedures for the determination of pesticides are reviewed and future trends in this field are indicated. We believe that this comprehensive review can be a good starting place for the future readers interested in the impact of environmental xenobiotics on the health of children as well as the aspects relates with the analytical methods that can be used for analysis and monitoring of these pollutants in children's tissues and biofluids.

  • How Swiss Watchmaking Brands are Communicating Made in Switzerland
    • Alina Rech
    • Alice Noris
    • Nadzeya Sabatini
    2023

    Country-of-origin indications, also called “made in” labeling [35], are utilized in marketing strategies by companies to distinguish themselves from others, trying to associate their products with positive characteristics [9]. Swiss watchmaking companies have an iconic status that is essential to their reputation - mainly due to their high quality, precision, innovation, and craftsmanship [7]. They are also using country-of-origin information as a competitive advantage in their communication strategies [11]. Although people have become acquainted with the “Swiss-made” label, and numerous studies have been dedicated to diverse Swiss watchmaking field topics [26], a significant research gap exists regarding the understanding of what are the “made in Switzerland” communication strategies and how Swiss watchmaking brands are using them. This study aims to examine how country-of-origin symbols - considering Swiss made related terms - and watchmaking-related words are employed by analyzing the official communication of thirty Swiss watchmaking brands.

  • How the Depths of the Danish Straits Shape Gdańsk's Port and City Spatial Development
    • Karolina Krośnicka
    • Aleksandra Wawrzyńska
    2023 Pełny tekst Urban Planning

    The depths of the Danish Straits limit the drafts of ships entering the Baltic Sea. The largest ships calling the Baltic in a laden condition are called Baltimax. The article presents how the dredging works carried out in the Danish Straits in the 1970s enabled the development of the Port of Gdańsk and consequently also influenced the city, being a residential base for employees of the new port and shipyards. The analysed case proves that, for port cities, overcoming a distant navigational bottleneck by dredging the existing passage or constructing a new channel might lead to a significant change in their development. The article also raises a question on the current development opportunities of the Port of Gdańsk, which is again increasingly limited by the depths of the Danish Straits, as large tankers and bulk carriers have already been entering Gdańsk not fully loaded for some time, and recently the largest container ships also reached the maximum permissible drafts.

  • How to evaluate methods used in chemical laboratories in terms of the total chemical risk? – a ChlorTox Scale
    • Paweł Mateusz Nowak
    • Renata Wietecha-Posłuszny
    • Justyna Płotka-Wasylka
    • Marek Tobiszewski
    2023 Pełny tekst Green Analytical Chemistry

    Reliable assessment of the health and environmental risk associated with the use of chemicals is critical to ob- jectively evaluate the greenness and whiteness of an analytical method. An objective and useful way of risk assessment should take into account all the relevant properties of used substances, their actual amounts needed for application of the method, and quantify the assessment result using a standardized unit. This article presents a relatively simple approach to meet the above requirements, which we call the Chloroform-oriented Toxicity Estimation Scale (ChlorTox Scale). The risk posed by a given substance is expressed by the ChlorTox value, and the sum of the values obtained for all reagents is the overall risk posed by the method (Total ChlorTox). The ChlorTox value is calculated by comparing the hazards for the substance being assessed to the standard – chlo- roform, using the approach selected by the user as optimal, taking into account the amount of a pure substance needed for single analysis. The ChlorTox unit is the equivalent mass of chloroform which reflects the estimated degree of predicted risk. This tool can be used for risk assessment in laboratories of various profiles

  • Human Resource Management Digitalisation in Multidisciplinary Ship Design Companies
    • Piotr Bilon
    • Wojciech Litwin
    2023 Pełny tekst Polish Maritime Research

    The digitalisation in the ship design sector is currently applied to the design process itself and is well defined, partially standardised and practically implemented by both independent design companies and the design departments of shipyards. The situation is similar in other sectors of engineering. However, the requirements for the digitalisation of other processes in design and engineering companies have not previously been studied, and the limited financial resources of ship design companies mean that there is a need for research on the digitalisation needs of multidisciplinary ship design companies. The implementation of building information modelling (BIM) solutions is costly for design companies and generates benefits mainly for shipyards and shipowners. The lack of benefits for design companies leads to the hesitation of managers whenever digitalisation is considered; the scope and scale of the digitalisation, as well as the selected software and BIM level, are defined by the shipyard requirements. The participation and support of management in the digitalisation process is one of the key success factors; the expected benefits caused by digitalisation for the organisation will increase the motivation of managers to invest limited resources in digitalisation. There are no data that indicate the processes with a high potential for digitalisation and the scale of expected improvements in ship design companies; therefore, research in this area was performed with a group of project managers from design and engineering companies. The research focused on collecting the opinions and experiences of the managers related to the manual management of resources and comparing the poll results with the conclusions from the enterprise resource planning (ERP) system data analyses. The paper analyses if the digital automation of the resource management process can lead to the substantial improvement of the operations of multi-project, multidisciplinary engineering ship design companies.

  • Hybrid all-cellulose reinforcement in polypropylene matrix biocomposites for injection moulding - influence of particle geometry and volume fraction on hybrid effect
    • P. Franciszczak
    • Jakub Smoliński
    2023 COMPOSITE STRUCTURES

    The presented study is focused on evaluation of influence of reinforcement volume fraction and geometry on the occurrence of positive hybrid effect by the hybridisation of man-made cellulose fibres (rayon viscose) with cellulose microparticle fillers applied in polypropylene matrix. Four volume fractions of reinforcement were used at 1:1 combination of short man-made cellulose fibres with cellulose microfillers of different aspect ratio. The highest volume fraction was applied for a comparison of four types of cellulose microfillers characterised by different aspect ratios. Proportional volume content of compatibiliser to volume of reinforcement and manufacturing conditions were maintained for all composites. Positive hybrid effect present in tensile and flexural performance was found to result from different factors such as: favourable combination of reinforcement owing to their similar stress–strain characteristic, decreased void fraction, slightly improved orientation of short rayon viscose fibres in hybrid and reduced relaxation of stresses during deformation.

  • Hybrydowa koncepcja łagodzenia stromości zmian napięcia du/dt dla wielopoziomowych przekształtników kaskadowych SiC
    • Marek Adamowicz
    • Janusz Szewczyk
    • Zbigniew Krzemiński
    2023 Pełny tekst Przegląd Elektrotechniczny

    W referacie zaproponowano nową hybrydową koncepcję łagodzenia stromości zmian napięcia du/dt w wielopoziomowych przekształtnikach kaskadowych SiC. Proponoana koncepcja polega na wykorzystaniu nietłumionego filtra du/dt, podatnego na rezonans oraz zastosowaniu w algorytmie sterowania PWM dodatkowych impulsów sterujących tranzystorami SiC MOSFET, wymuszających rezonansowe przełączanie napięcia na wyjściu filtra. Efekt zmniejszenia stromości du/dt w przekształtniku wielopoziomowym uzyskuje się przy wykorzystaniu pojedynczego filtra du/dt, wspólnego dla całej gałęzi fazowej, co pozwala uzyskać kompaktową konstrukcję całego przekształtnika.

  • Hydraulic fracturing process in rocks – small-scale simulations with a novel fully coupled DEM/CFD-based thermo-hydro-mechanical approach
    • Marek Krzaczek
    • Andrzej Tejchman-Konarzewski
    2023 Pełny tekst ENGINEERING FRACTURE MECHANICS

    W artykule przedstawiono dwuwymiarową (2D) symulację numeryczną szczelinowania hydraulicznego w małej skali przeprowadzoną w próbkach skał posiadających pojedynczą szczelinę wtryskową. Wykorzystano unikalny model termo-hydro-mechaniczny (THM) w skali porów oparty na DEM/CFD do symulacji dwufazowego laminarnego przepływu płynu (wody i gazu) z przenoszeniem ciepła w nienasyconych materiałach porowatych o niskiej porowatości. Korzystając z metody DEM w pełni połączonej z metodą CFD (w oparciu o sieć przepływu płynu składającą się z kanałów w domenie ciągłej pomiędzy dyskretnymi elementami) i przenoszeniem ciepła w mezoskali, przeprowadzono serię obliczeń numerycznych dla małych spoistych próbek ziarnistych o uproszczonej mezostrukturze z jedną szczeliną wtryskową. Przyjęto dwuosiowe ściskanie w warunkach płaskiego stanu odkształcenia. Zarówno płyn (dyfuzja i adwekcja), jak i połączone cząstki skały (przewodnictwo) wzięły udział w wymianie ciepła. Zbadano szczegółowo w procesie szczelinowania hydraulicznego wpływ lepkości dynamicznej płynu, zawartości fazy gazowej i różnicy temperatur pomiędzy matrycą skalną a wtryskiem płynu na inicjację i propagację pęknięcia. Odkryto, że te efekty wszystkie miały ogromne znaczenie na zachowanie si ępojedynczego pęknięcia hydraulicznego.

  • Hydrazinolysis Products of Selected Sugar Lactones—Crystal Structure and Microbiological Activity
    • Justyna Samaszko-Fiertek
    • Artur Sikorski
    • Barbara Dmochowska
    • Piotr Szweda
    • Janusz Madaj
    2023 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    Commercially available lactones, as well as those synthesized by us, turned out to be good substrates for the synthesis of sugar hydrazides. The exception was L-ascorbic acid, whose hydrazinolysis led to the formation of a hydrazinium salt, not the hydrazide as expected. The structure of all compounds was confirmed by NMR and X-ray analyses. The lower durability of hydrazinium L-ascorbate was additionally confirmed by thermogravimetric tests. All products were tested for biological activity against Gram-negative bacteria strains Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853 and against Gram-positive Staphylococcus aureus ATCC 25923 and Staphylococcus aureus ATCC 29213. Their antifungal activity against Candida albicans SC5314, Candida glabrata DSM 11226 SM 11226, Candida krusei DSM 6128, and Candida parapsilosis DSM 5784 was also tested. The most interesting results of microbiological activity were obtained for D-gluconic acid hydrazide and hydrazinium L-ascorbate. The results of the latter encourage more extensive testing.

  • Hydrochar-nanoparticle integration for arsenic removal from wastewater: Challenges, possible solutions, and future horizon
    • Aisha Khanzada
    • Hussein Al-Hazmi
    • Bogna Śniatała
    • Tomy Muringayil
    • Joanna Majtacz
    • Sameer A.M. Abdulrahman
    • Saeed S. Albaseer
    • Tonni Agustiono Kurniawan
    • Zohreh Rahimi-Ahar
    • Sajjad Habibzadeh
    • Jacek Mąkinia
    2023 ENVIRONMENTAL RESEARCH

    Arsenic (As) contamination poses a significant threat to human health, ecosystems, and agriculture, with levels ranging from 12 to 75% attributed to mine waste and stream sediments. This naturally element is abundant in Earth's crust and gets released into the environment through mining and rock processing, causing ≈363 million people to depend on As-contaminated groundwater. To combat this issue, introducing a sustainable hydrochar system has achieved a remarkable removal efficiency of over 92% for arsenic through adsorption. This comprehensive review presents an overview of As contamination in the environment, with a specific focus on its impact on drinking water and wastewater. It delves into the far-reaching effects of As on human health, ecosystems, aquatic systems, and agriculture, while also exploring the effectiveness of existing As treatment systems. Additionally, the study examines the potential of hydrochar as an efficient adsorbent for As removal from water/wastewater, along with other relevant adsorbents and biomass-based preparations of hydrochar. Notably, the fusion of hydrochar with nanoparticle-centric approaches presents a highly promising and environmentally friendly solution for achieving the removal of As from wastewater, exceeding >99% efficiency. This innovative approach holds immense potential for advancing the realms of green chemistry and environmental restoration. Various challenges associated with As contamination and treatment are highlighted, and proposed solutions are discussed. The review emphasizes the urgent need to advance treatment technologies, improve monitoring methods, and enhance regulatory frameworks. Looking outlook, the article underscores the importance of fostering research efforts, raising public awareness, and fostering interdisciplinary collaboration to address this critical environmental issue. Such efforts are vital for UN Sustainable Development Goals, especially clean water and sanitation (Goal 6) and climate action (Goal 13), crucial for global sustainability.

  • Hydrogen Production Mechanism in Low-Temperature Methanol Decomposition Catalyzed by Ni3Sn4 Intermetallic Compound: A Combined Operando and Density Functional Theory Investigation
    • Silvia Mauri
    • Gianluca D'Olimpio
    • Corneliu Ghica
    • Luca Braglia
    • Chia-Nung Kuo
    • Marian Cosmin Istrate
    • Chin Shan Lue
    • Luca Ottaviano
    • Tomasz Klimczuk
    • Danil W. Boukhvalov
    • Antonio Politano
    • Piero Torelli
    2023 Journal of Physical Chemistry Letters

    Hydrogen production from methanol decomposition to syngas (H2 + CO) is a promising alternative route for clean energy transition. One major challenge is related to the quest for stable, cost-effective, and selective catalysts operating below 400 °C. We illustrate an investigation of the surface reactivity of a Ni3Sn4 catalyst working at 250 °C, by combining density functional theory, operando X-ray absorption spectroscopy, and high-resolution transmission electron microscopy. We discovered that the catalytic reaction is driven by surface tin-oxide phases, which protects the underlying Ni atoms from irreversible chemical modifications, increasing the catalyst durability. Moreover, we found that Sn content plays a key role in enhancing the H2 selectivity, with respect to secondary products such as CO2. These findings open new perspectives for the engineering of scalable and low-cost catalysts for hydrogen production.

  • Hydrophobic (deep) eutectic solvents (HDESs) as extractants for removal of pollutants from water and wastewater – A review
    • Mateusz Marchel
    • Manoj P Rayaroth
    • Chongqing Wang
    • Lingshuai Kong
    • Javed Khan
    • Grzegorz Boczkaj
    2023 Pełny tekst CHEMICAL ENGINEERING JOURNAL

    Deep eutectic solvents (DESs) are a new generation of solvents that attracted increasing attention in diverse applications. In last years, growing number of studies on hydrophobic (deep) eutectic solvents (HDESs) as an alternative extractants for various chemicals from aqueous environments have been reported. This article provides an overview on the usage of HDESs in liquid–liquid extraction (LLE) of different pollutants from water and wastewater, where purified water tends to be further used or released into the environment. Discussed applications were developed for several emerging organic pollutants, such as pharmaceuticals (including antibiotics – ciprofloxacin, sulfamethoxazole, trimethoprim and vasoprotectant – calcium dobesilate), pesticides (neonicotinoids – imidacloprid, thiamethoxam, nitenpyram, acetamiprid), phenolic compounds, metal ions, among others. The particular attention was given to discuss chemical stability of HDESs after contact with water. On this basis, a matrix of possible water stable DESs was proposed. Furthermore, simple protocols to control HDESs solubility were suggested. Finally, the suggestions and guidelines for future research were provided, with focus on most important physicochemical properties of HDESs playing a key role in presented application. A perspective on their future was discussed suggesting that such HDESs-based LLE should be mainly used for pre-treatment of wastewater with high pollution load, followed by adsorption or biological treatment process for removal of HDES traces. This review also highlights a serious environmental issue related to application of HDESs for sample preparation (microextraction) in analytical chemistry. Waste aqueous samples can contain hazardous – HDES related – substances and their utilization should be done with proper care on this aspect.

  • I love to write and create. Can I earn money doing it? Entrepreneurial process of bloggers
    • Julita Wasilczuk
    • Jarna Heinonen
    2023

    New technologies and a new way of looking at the life of future generations, open up new perspectives of entrepreneurial activities. One of them is to run a blog. Although the first blogs appeared many years ago and earning money from running them is also known to bloggers, little research is devoted to this form of entrepreneurship. The analysis of this phenomenon was carried out using the netnography method, which is not common in research on entrepreneurship. The literature review shows that modern technologies have mobilized researchers to search for new definitions and approaches in the study of entrepreneurship. Opening up to the customer and allowing him to co-create the product is one of the changes that digital entrepreneurship, in particular in connection with social media, has introduced. The latter provide not only a commercial product, but also non-commercial values, which nowadays are of great importance (e.g. emotional support, information, knowledge, sense of belonging to the community). A blogger's entrepreneurial process is very broadly similar to a typical entrepreneurial process, consists of a preparatory phase and an implementation phase. However, this similarity is only superficially similar. A blogger must be credible in the eyes of the community to which he directs his blog, which is not and will not necessarily be his clients. This credibility will help him attract clients, both individual and corporate. Each of these groups is interested in a different product: An individual client will purchase in the blogger's store, and a corporate client will be interested in partner cooperation. That is why the preparatory phase mainly includes the legitimization of the blog and the content on it. The difference between traditional entrepreneurs and blogger entrepreneurs also appears in the area of consumers and the product. The blogger deals with customers who pay and those who do not pay - and the latter are the most numerous. However, they are very important in the entrepreneurial process, as they constitute the basis for the monetization of a blog. And since there are non-paying customers, there is also a free product that is the core of all blogging, blogger's regular entries.

  • Idea zrównoważonego rozwoju
    • Anna Kuczyńska-Łażewska
    2023

    Zrównoważony rozwój to termin bardzo popularny, w ostatnich latach pojawiający się nie tylko w aktach prawnych, statutach i dokumentach strategicznych, lecz także w publikacjach naukowych czy wnioskach grantowych. Dla wielu osób mimo jasności koncepcji i rozumienia przekazu termin ten jest niejednoznaczny i pozwala na dowolną interpretację.

  • Identification of High-Value Dataset determinants: is there a silver bullet for efficient sustainability-oriented data-driven development?
    • Anastasija Nikiforova
    • Charalampos Harris Alexopoulos
    • Nina Rizun
    • Magdalena Ciesielska
    2023

    Open Government Data (OGD) are seen as one of the trends that has the potential to benefit the economy, improve the quality, efficiency, and transparency of public administration, and change the lives of citizens, and the society as a whole facilitating efficient sustainability-oriented data-driven services. However, the quick achievement of these benefits is closely related to the “value” of the OGD, i.e., how useful, and reusable the data provided by public agencies are for creating value for the above stakeholder. This is where the notion of "high-value datasets" (HVD), defined by the European Commission in Open Data Directive, comes, referring to data that can create the most value for society, the economy, and the environment. This is even more so, considering the proliferation of Artificial Intelligence (AI) and machine learning (ML) applications in various domains. While there are some efforts in that direction, there is still no available framework for identifying country-specific high-value datasets (and their determinants). The objective of the workshop is to raise awareness and build a network of key stakeholders around the HVD issue, to allow each participant to think about how and whether the determination of HVD is taking place in their country, how this can be improved with the help of portal owners, data publishers, data owners, businesses and citizens, what are and can be determinants to be used for identifying HVDs, whether they are SMART. Our main motivation is that, as members of the dg.o community, we can collaboratively answer the above questions, and those raised during the previous two editions of this workshop at ICEGOV2022 and ICOD2022, forming an initial knowledge base, as well as assessing currently used indicators. In this 3rd edition of the workshop, previously obtained results, which make up a list of the most promising indicators, will be discussed, validated and possibly refined through live discussions with the workshop participants following the DELPHI method.

  • Identification of ship’s hull mathematical model with numerical methods
    • Agnieszka Piekło
    • Paweł Hoffmann
    • Anna Witkowska
    • Tomasz Zubowicz
    2023 Pełny tekst

    The modern maritime industry is moving toward the development of technology that will allow for full or partial autonomy of ship operation. This innovation places high demands on ship performance prediction techniques at the design stage. The researchwork presented in the article is related to the design stage of the ship and concerns methods for prognosis and evaluation of the specific operational condition of the ship, namely the dynamic positioning (DP). The paper is an introduction to a study that seeks to assess the impact of using advanced simulation models on the accuracy of DP capability prediction. To this end, the Potential Theory and methods of Computational Fluid Dynamics (CFD) are applied to determine the mathematical model of the ship. The parameters obtained in the course of simulation studies have been compared to those obtained experimentally. The study showed that the proposed method is sufficiently accurate for the purposes of determining the added mass and damping coefficients of the ship. Consequently, it is considered that design offices could improve the accuracy of the DP prediction by using mathematical modeling and numerical methods to estimate selected ship parameters.

  • Impact assessment culture in the European Union. Time for something new?
    • Andrea Saltelli,
    • Marta Kuc-Czarnecka
    • Samuele Lo Piano
    • Máté János Lőrincz
    • Magdalena Olczyk
    • Arnald Puy,
    • Erik, S. Reinert
    • Stefán Thor Smith
    • Jeroen P. van der Sluijs
    2023 Pełny tekst ENVIRONMENTAL SCIENCE & POLICY

    Current approaches and cultures for the economic evaluations of environmental and health policies may suffer from excessive reliance on a standard neoclassic economic toolbox that neglects alternative perspectives. This may prematurely limit the spectrum of available policy options. Here we show how the inclusion of neglected currents of thought such as non-Ricardian economics, bioeconomics and a set of qualitative-quantitative methods from post-normal science leads to richer perspectives for a more inclusive uses of quantitative evidence, and opens the analysis to more possible futures. We also present some case studies in the energy, water, health and climate domains that highlight the point in a practical context for a more policy-oriented audience. We situate our analysis in the context of recent calls in the EU for the inclusion of more perspectives from the social sciences and the humanities in environmental assessment works.

  • Impact of AlphaFold on structure prediction of protein complexes: The CASP15‐CAPRI experiment
    • Marc F. Lensink
    • Guillaume Brysbaert
    • Nessim Raouraoua
    • Paul A. Bates
    • Marco Giulini
    • Rodrigo Vargas Honorato
    • Charlotte van Noort
    • Joao S. Teixeira
    • Alexandre M. J. J. Bonvin
    • Ren Kong
    • Hang Shi
    • Xufeng Lu
    • Shan Chang
    • Jian Liu
    • Zhiye Guo
    • Xiao Chen
    • Alex Morehead
    • Raj S. Roy
    • Tianqi Wu
    • Nabin Giri
    • Farhan Quadir
    • Chen Chen
    • Jianlin Cheng
    • Carlos A. Del Carpio
    • Eichiro Ichiishi
    • Luis A. Rodriguez‐Lumbreras
    • Juan Fernandez‐Recio
    • Ameya Harmalkar
    • Lee‐Shin Chu
    • Sam Canner
    • Rituparna Smanta
    • Jeffrey J. Gray
    • Hao Li
    • Peicong Lin
    • Jiahua He
    • Huanyu Tao
    • Sheng‐You Huang
    • Jorge Roel‐Touris
    • Brian Jimenez‐Garcia
    • Charles Christoffer
    • Anika J. Jain
    • Yuki Kagaya
    • Harini Kannan
    • Tsukasa Nakamura
    • Genki Terashi
    • Jacob Verburgt
    • Yuanyuan Zhang
    • Zicong Zhang
    • Hayato Fujuta
    • Masakazu Sekijima
    • Daisuke Kihara
    • Omeir Khan
    • Sergei Kotelnikov
    • Usman Ghani
    • Dzmitry Padhorny
    • Dmitri Beglov
    • Sandor Vajda
    • Dima Kozakov
    • Surendra S. Negi
    • Tiziana Ricciardelli
    • Didier Barradas‐Bautista
    • Zhen Cao
    • Mohit Chawla
    • Luigi Cavallo
    • Romina Oliva
    • Rui Yin
    • Melyssa Cheung
    • Johnathan D. Guest
    • Jessica Lee
    • Brian G. Pierce
    • Ben Shor
    • Tomer Cohen
    • Matan Halfon
    • Dina Schneidman‐Duhovny
    • Shaowen Zhu
    • Rujie Yin
    • Yuanfei Sun
    • Yang Shen
    • Martyna Maszota-Zieleniak
    • Krzysztof Bojarski
    • Emilia Lubecka
    • Mateusz Marcisz
    • Annemarie Danielsson
    • Lukasz Dziadek
    • Margrethe Gaardlos
    • Artur Gieldon
    • Adam Liwo
    • Sergey A. Samsonov
    • Rafał Ślusarz
    • Karolina ZiĘba
    • Adam Sieradzan
    • Cezary Czaplewski
    • Shinpei Kobayashi
    • Yuta Miyakawa
    • Yasuomi Kiyota
    • Mayuko Takeda-shitaka
    • Kliment Olechnovič
    • Lukas Valancauskas
    • Justas Dapkunas
    • Česlovas Venclovas
    • Bjorn Wallner
    • Lin Yang
    • Chengyu Hou
    • Xiaodong He
    • Shuai Guo
    • Shenda Jiang
    • Xiaoliang Ma
    • Rui Duan
    • Liming Qui
    • Xianjin Xu
    • Xiaoqin Zou
    • Sameer Velankar
    • Shoshana J. Wodak
    2023 Pełny tekst PROTEINS-STRUCTURE FUNCTION AND BIOINFORMATICS

    We present the results for CAPRI Round 54, the 5th joint CASP-CAPRI protein assembly prediction challenge. The Round offered 37 targets, including 14 homodimers, 3 homo-trimers, 13 heterodimers including 3 antibody–antigen complexes, and 7 large assemblies. On average 70 CASP and CAPRI predictor groups, including more than 20 automatics servers, submitted models for each target. A total of 21 941 models submitted by these groups and by 15 CAPRI scorer groups were evaluated using the CAPRI model quality measures and the DockQ score consolidating these measures. The prediction performance was quantified by a weighted score based on the number of models of acceptable quality or higher submitted by each group among their five best models. Results show substantial progress achieved across a significant fraction of the 60+ participating groups. High-quality models were produced for about 40% of the targets compared to 8% two years earlier. This remarkable improvement is due to the wide use of the AlphaFold2 and AlphaFold2-Multimer software and the confidence metrics they provide. Notably, expanded sampling of candidate solutions by manipulating these deep learning inference engines, enriching multiple sequence alignments, or integration of advanced modeling tools, enabled top performing groups to exceed the performance of a standard AlphaFold2 Multimer version used as a yard stick. This notwithstanding, performance remained poor for complexes with antibodies and nanobodies, where evolutionary relationships between the binding partners are lacking, and for complexes featuring conformational flexibility, clearly indicating that the prediction of protein complexes remains a challenging problem.

  • Impact of blending with polystyrene on the microstructural and electrochemical properties of SiOC ceramic
    • Monika Wilamowska-Zawłocka
    • Magdalena Graczyk-Zajac
    2023 Pełny tekst International Journal of Applied Ceramic Technology

    In this work, we present the electrochemical behavior and microstructural analysis of silicon oxycarbide (SiOC) ceramics influenced by an addition of polystyrene (PS). Polymer-derived ceramics were obtained by pyrolysis (1000°C, Ar atmosphere) of different polysiloxanes prepared by sol–gel synthesis. This method is very effective to obtain desired composition of final ceramic. Two alkoxysilanes phenylthriethoxysilane and diphenyldimethoxysilane were used as precursors. Before pyrolysis polysiloxanes were mixed with PS using toluene as a solvent. Blending with PS affects the microstructure and free carbon content in the final ceramic material. Free carbon phase has been confirmed to be a major lithium storage host. Nevertheless, we demonstrate here that capacity does not increase linearly with increasing carbon content. We show that the amount of SiO4 units in the SiOC microstructure increases the initial capacity but decreases the cycling stability and rate capability of the material. Furthermore, the microstructure of the free carbon influences the electrochemical performance of the ceramic: More ordered graphitic clusters favor better rate capability performance.

  • Impact of climate change on groundwater recharge in shallow young glacial aquifers in northern Poland
    • Anna Gumuła-Kawęcka
    • Beata Jaworska-Szulc
    • Adam Szymkiewicz
    • Wioletta Gorczewska-Langner
    • Rafael Angulo-Jaramillo
    • Jirka Simunek
    2023 SCIENCE OF THE TOTAL ENVIRONMENT

    We investigated the influence of climate change in the period 1951–2020 on shallow aquifers in the Brda and Wda outwash plains (Pomeranian Region, Northern Poland). There was a significant temperature rise (0.3 °C/10 years), which accelerated after 1980 (0.66 °C/10 years). Precipitation became increasingly irregular – extremely rainy years occurred right after or before extremely dry years, and intensive rainfall events became more frequent after 2000. The groundwater level decreased over the last 20 years, even though the average annual precipitation was higher than in the previous 50 years. We carried out numerical simulations of water flow in representative soil profiles for the years 1970–2020 using the HYDRUS-1D model, developed and calibrated during our earlier work at an experimental site in the Brda outwash plain (Gumuła-Kawęcka et al., 2022). We used a relationship between the water head and flux at the bottom of the soil profiles (the third-type boundary condition) to reproduce groundwater table fluctuations caused by recharge variability in time. The calculated daily recharge showed a decreasing linear trend for the last 20 years (0.05–0.06 mm d−1/10 years), and dropping trends in water table level and soil water content in the entire profile of vadose zone. Field tracer experiments were performed to estimate impact of extremely rain events on water flux in vadose zone. The results suggest that tracer travel times are strongly determined by water content in the unsaturated zone which is determined by precipitation amount in span of weeks, rather than extremely high precipitation events.

  • Impact of Climate Change on Water Sources and River‐Floodplain Mixing in the Natural Wetland Floodplain of Biebrza River
    • Tomasz Edward Berezowski
    • Daniel Partington
    2023 Pełny tekst WATER RESOURCES RESEARCH

    The origins of river and floodplain waters (groundwater, rainfall, and snowmelt) and their extent during overbank flow events strongly impact ecological processes such as denitrification and vegetation development. However, the long-term sensitivity of floodplain water signatures to climate change remains elusive. We examined how the integrated hydrological model HydroGeoSphere and the Hydraulic Mixing-Cell method could help us understand the long-term impact of climate change on water signatures and their spatial distribution in the protected Biebrza River Catchment in northeastern Poland. Our model relied on 20th century Reanalysis Data from 1881 to 2015 and an ensemble of EURO-CORDEX simulations for representative concentration pathways (RCP) 2.6, 4.5, and 8.5 from 2006 to 2099. The historical component of the simulations was subjected to extensive multiple-variable validation from 1881 to 2019. The results show that the extents of water sources were rather stable in the floodplain in the 1881–2015 period. The projected future impacts were variable with each analyzed RCP, but in all cases, different significant trends were present for the spatial distribution of water sources and for the river-floodplain mixing. However, the total volume of water from different sources was less sensitive to climate change than the dominant sources and spatial distribution of water. The simulation results highlight the impact of climate change on the extent of water sources in temperate zone wetlands with significant implications for ecological processes and management. These results also underscore the urgent need to leverage such modeling studies to inform protective and preservation strategies of floodplain wetlands.

  • Impact of laser beam welding on mechanical behaviour of 2.25Cr–1Mo (P22) steel
    • Sachin Sirohi
    • Shailesh M. Pandey
    • Vinita Tiwari
    • Dhowmya Bhatt
    • Dariusz Fydrych
    • Chandan Pandey
    2023 INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING

    The use of welding processes in the manufacturing and repair of structures intended for the energy industry plays a key role in the guarantee of a continuous supply of fossil fuels, which is the basic condition for ensuring energy security. A square butt joint of 10 mm thick plate of 2.25Cr–1Mo (P22) steel was fabricated by autogenous laser beam welding process and then post-weld heat treatment (PWHT) for two sets of process parameters (760 °C for 90 min–T1 and 730 °C for 180 min–T2). The joints were subjected to detailed metallographic investigations and hardness measurements, static tensile tests and impact toughness tests. The joint in as-welded state is characterized by significant heterogeneity of structural morphology and mechanical properties, while PWHT significantly improves uniformity in microstructure and mechanical properties along weldments. PWHT in particular causes tempering of the bainite and promotes the formation of carbide precipitates (M7C3, M23C6, and Mo2C) of globular and spherical shape along boundaries and bainite blocks. Laser welding caused a drastic increase in the weld metal hardness (388 HV) and coarse prior austenite grain bainite region (390 HV) compared to the hardness of base metal (BM) (below 200 HV). Both of the applied PWHT variants reduced the hardness of these areas of welded joints to the BM level. During the tensile tests, all the joints were fractured in BM. In the case of AW joints the tensile strength was higher than BM and it was 625 ± 10 MPa and after both PWHT, tensile strength was decreased by about 100 MPa. Due to over tempering of bainite in BM the elongation of the joints was several percentage points lower (27 ± 3 for AW joints) than the value for BM (35% ± 2), but slightly higher in the case of joints after PWHT (31 and 33 ± 1). Impact energy of the weld metal (259 ± 8 J) was lower than P22 base metal (320 ± 8 J), but PWHT causes a significant increase in impact energy of the weld metal (291 ± 6 J and 306 ± 10 J for T1 and T2, respectively). The analysis of these results shows that the proposed laser welding procedure with a high temperature gradient and PWHT enables the fabrication of P22 steel welded joints that meet the quality criteria.

  • Impact of rotor geometry optimization on the off-design ORC turbine performance
    • Łukasz Witanowski
    • Piotr Klonowicz
    • Piotr Lampart
    • Piotr Klimaszewski
    • Tomasz Suchocki
    • Łukasz Jędrzejewski
    • Dawid Zaniewski
    • Paweł Ziółkowski
    2023 ENERGY

    The paper describes the method of CFD based Nelder-Mead optimization of a 10 kW single-stage axial turbine operating in an ORC system working on R7100. The total-to-static isentropic efficiency is defined as an objective function. Multi-point linear regression is carried out to determine the significance of the objective function arguments and to pick up the set of particular variables and characteristic quantities (e.g. flow angles) which contribute most to improving the objective function value. This approach enables us to considerably reduce the number of optimized parameters and computational time needed for the optimization process. Variable operating parameters of ORC power systems become an everyday occurrence, which makes the analysis of ORC turbines under variable operating parameters a critical part of the design. Therefore, the paper presents the influence of a single-criterion optimization of the rotor geometry on the performance of the ORC turbine in a wide range of operating conditions. The results of optimization indicate that new geometry provides an approximately 5.5 pp. (percentage point) increase in total-to-static efficiency for the design point, and even larger improvements reaching 7 pp. For higher turbine loads, whereas for lower loads the efficiency improvements are at the level of 1.5–4 pp.

  • Impact of soluble organic matter and particulate organic matter on anammox system: Performance, microbial community and N2O production
    • Yingying He
    • Hongyu Mao
    • Jacek Mąkinia
    • Jakub Drewnowski
    • Bing Wu
    • Jun Xu
    • Li Xie
    • Xi Lu
    2023 JOURNAL OF ENVIRONMENTAL SCIENCES-CHINA

    In this study, the effects of soluble readily biodegradable COD (sCOD) and particulate slowly biodegradable COD (pCOD) on anammox process were investigated. The results of the longterm experiment indicated that a low sCOD/N ratio of 0.5 could accelerate the anammox and denitrification activity, to reach as high as 84.9% ±2.8% TN removal efficiency. Partial denitrification-anammox (PDN/anammox) and denitrification were proposed as the major pathways for nitrogen removal, accounting for 91.3% and 8.7% of the TN removal, respec- tively. Anammox bacteria could remain active with high abundance of anammox genes to maintain its dominance. Candidatus Kuenenia and Thauera were the predominant genera in the presence of organic matter. Compared with sCOD, batch experiments showed that the introduction of pCOD had a negative effect on nitrogen removal. The contribution of denitrification to nitrogen removal decreased from approximately 14% to 3% with increasing percentage of pCOD. In addition, the analysis result of the process data using an optimized ASM1 model indicated that high percentage of pCOD resulted in serious N 2 O emission (the peak value up to 0.25 mg N/L), which was likely due to limited mass diffusion and insufficient available carbon sources for denitrification. However, a high sCOD/N ratio was beneficial for alleviating N 2 O accumulation.

  • Impact of steel grade on a ship colliding with an offshore wind turbine monopile supporting structure
    • Karol Niklas
    • Alicja Bera
    • Yordan Garbatov
    2023 Pełny tekst OCEAN ENGINEERING

    Offshore wind power is experiencing rapid development around the world. The number of installations and their size is growing. Thousands of monopile support structures with diameters of 10 m and weights of 2000 tons will be installed in the coming years. Offshore wind power installations, often located close to the shore and shipping routes, pose a new challenge to ship safety. The study analyses the damages from an accidental collision between a 6500-tonne displacement Supply Offshore Vessel and the monopile support structure with a 10 m diameter and a 15 MW wind turbine. The head-on collision cases are performed according to the DNV-ST-0126, showing the consequences for the ship and the wind turbine support structure. In addition, simulation cases with an offset between the ship’s plane of symmetry and the monopile axis showed a new form of damage to the ship’s plating. During a head-on sliding collision, extensive plate tearing can occur due to its cutting at the deck line and concertina tearing under the pressure of the monopile. As a result, the hull may open over a large area, including the threat of unsealing the ship’s collision bulkhead. The S355 grade steel can significantly reduce collision damage by up to 50% (from 20.6 m2 to 10.5 m2 for the case studied here).

  • Impact of strontium non-stoichiometry of SrxTi0.3Fe0.7O3-δ on structural, electrical, and electrochemical properties for potential oxygen electrode of intermediate temperature solid oxide cells
    • Aleksander Mroziński
    • Sebastian Molin
    • Patryk Błaszczak
    • Tadeusz Miruszewski
    • Karolina Górnicka
    • Jakub Karczewski
    • Piotr Jasiński
    2023 Pełny tekst INTERNATIONAL JOURNAL OF HYDROGEN ENERGY

    This work presents the results of a comprehensive study on the impact of the A-site non-stoichiometry of SrxTi0.3Fe0.7O3-δ (x = 0.90, 0.95, 1.00, 1.05) ceramics on their physicochemical properties. The materials were fabricated by the conventional solid-state reaction method and their structure was determined by X-ray diffractometry, X-ray photoelectron spectroscopy and electron microscopy. Their sintering and thermal expansion properties were then evaluated. The electrical properties of the materials were determined by electrical conductivity and electrical relaxation measurements (on bulk materials) and by electrochemical impedance spectroscopy (EIS) studies of symmetrical, CGO-electrolyte based, porous electrodes. Finally, fuel cell tests with the non-stoichiometric electrodes were evaluated. To elucidate the electrochemical reaction pathways for oxygen reduction/evolution reaction, EIS measurements were carried out in different pO2 and were analysed via the distribution of relaxation times method. The results showed a dependence of materials’ properties on the A-site non-stoichiometry, which can be used to fine-tune their properties, e.g. increase the surface exchange rate or decrease the thermal expansion coefficient.

  • Impact of temperature on optical sensing in biology based on investigation of SARS‐CoV ‐2
    • Małgorzata Szczerska
    • Paweł Wityk
    • Paulina Listewnik
    2023 Pełny tekst Journal of Biophotonics

    In this paper, we present an investigation of the influence of the temperature on the sensing of biological samples. We used biofunctionalized microsphere-based fiber-optic sensor to detect immunoglobulin G attached to the sensor head at temperatures relevant in biological research: 5°C, 25°C, and 55°C. The construction of the sensor allowed us to perform measurements in the small amount of solution. The results of our experiment confirm substantial changes in the measured reflected optical power, indicating the need to control the temperature during such measurements. The sensitivity of the sensor used in this research is 8.82 nW/°C. Coefficient R was also calculated and it equals 0.998, which shows good fit between theoretical linear fit and obtained measured data.

  • Impact of thermal backfill parameters on current-carrying capacity of power cables installed in the ground
    • Seweryn Szultka
    • Stanisław Czapp
    • Adam Tomaszewski
    2023 Pełny tekst Bulletin of the Polish Academy of Sciences-Technical Sciences

    Proper design of power installations with the participation of power cables buried in homogeneous and thermally well-conductive ground does not constitute a major problem. The situation changes when the ground is non-homogeneous and thermally low-conductive. In such a situation, a thermal backfill near the cables is commonly used. The optimization of thermal backfill parameters to achieve the highest possible current-carrying capacity is insufficiently described in the standards. Therefore, numerical calculations based on computational fluid dynamics could prove helpful for designers of power cable lines. This paper studies the influence of dimensions and thermal resistivity of the thermal backfill and thermal resistivity of the native soil on the current-carrying capacity of power cables buried in the ground. Numerical calculations were performed with ANSYS Fluent. As a result of the research, proposals were made on how to determine the current-carrying capacity depending on the dimensions and thermal properties of the backfill. A proprietary mathematical function is presented which makes it possible to calculate the cable current-carrying capacity correction factor when the backfill is used. The research is expected to fill the gap in the current state of knowledge included in the provisions of standards.

  • Implementacja aktów prawa w metodyce badań emisyjności akustycznej w transporcie szynowym
    • Roksana Licow
    • Natalia Karkosińska-Brzozowska
    • Anna Świerkoska
    • Wiktor Żółkoś
    • Przemysław Barszcz
    • Julia Szulta
    • Kamil Łukaszewicz
    • Izabela Muzyka
    • Aleks Gołąbek
    • Magdalena Jóźwik
    • Daria Kassin
    • Michał Polakowski
    • Mateusz Racki
    • Maciej Wolski
    • Bartosz Nowak
    2023

    Przedmiotem artykułu jest przedstawienie zakresu działań wraz ze wstępnymi wnioskami, które dotyczą realizowanego projektu Plutonium Supporting Student Research Teams pn. Badania emisyjności akustycznej w transporcie szynowym realizowanym przez Koło Naukowe Inżynierii Drogowej i Kolejowej Politechniki Gdańskiej. Celem projektu jest ocena emisyjności akustycznej typu nawierzchni z typem pojazdu szynowego oraz ocena komfortu podróżnych w transporcie kolejowym i tramwajowym w kontekście hałasu. Realizacja badań została zaplanowana dwutorowo:  pomiary zewnątrz pojazdu w kontekście zależności poziomu dźwięku w odniesieniu do określonych typów nawierzchni,  pomiary wewnątrz pojazdów w kontekście wpływu hałasu na komfort podróżnych. Zespół projektowy został podzielony na dwie grupy badawcze, jedna z grup działa w zakresie hałasu emitowanego przez pociągi, druga zaś hałasu emitowanego przez tramwaje. W artykule zawarto analizę literatury w tym norm oraz aktów prawnych dotyczących hałasu emitowanego we wewnątrz i na zewnątrz pojazdów szynowych. Analizę przeprowadzano dla pojazdów kolejowych oraz tramwajów. Na podstawie wniosków opracowano szereg metodyk prowadzenia badań akustycznych celem implementacji ich w realizacji eksperymentów na rzeczywistych obiektach podczas ich eksploatacji. Opracowana metodyka badań może być podstawą do zmian prawnych w sposobach i metodach oceny hałasu na zewnątrz i przede wszystkim wewnątrz pojazdów szynowych np. z uwzględnieniem różnych typów wagonów.

  • Implementation of an Adaptive Method for Changing the Frequency Division of the Counter Clock Signal in a Frequency-to-Code Converter
    • Dariusz Świsulski
    • Piotr Warda
    2023 Pełny tekst ENERGIES

    Processing physical quantities into an indirect signal is a standard method of transferring information about the measured quantity to the master system, which analyzes the data obtained from the acquisition system. The intermediate signal is very often the voltage, but another transmission medium can be the frequency of the output signal of the “physical quantity-to-frequency” converter. The article presents the implementation of the adaptive method of selecting the clock signal frequency of the counter working in the converter. The issue of selecting the clock signal frequency for the required processing range of the transducer is discussed in detail. The application of the method using the STM32L476RG microcontroller is presented. The principle of checking the processing range of the developed transducer model is discussed. The algorithms of transducer operation in basic and adaptive modes of measuring the period of the variable frequency signal are proposed. The results of operation, in both modes, of the transducer model of frequency processing are presented, along with the metrological analysis of the results. The influence of selected approximations used to reconstruct the measured quantity on the final presentation of the measurement result is discussed.

  • Implementation of IMS/NGN Transport Stratum Based on the SDN Concept
    • Sylwester Kaczmarek
    • Maciej Sac
    • Kamil Bachorski
    2023 Pełny tekst SENSORS

    The paper presents the development and verification of software and a testbed aiming to demonstrate the ability of two telecommunication network concepts—Next Generation Network (NGN) and Software-Defined Networking (SDN)—to cooperate. The proposed architecture includes components of the IP Multimedia Subsystem (IMS) in its service stratum and of the SDN (controller and programmable switches) in its transport stratum, providing flexible transport resource control and management via open interfaces. One important feature of the presented solution is the inclusion of ITU-T standards for NGN networks, which are not considered in other related works. The paper includes details regarding the hardware and software architecture of the proposed solution as well as results of the performed functional tests, which confirm its proper operation.

  • IMPLEMENTING THE QUALITY ASSURANCE SYSTEM AND ASSURING HEALTH SAFETY IN THE LIGHT OF INCREASING BREAD QUALITY
    • Radosław Drozd
    • Radosław Wolniak
    2023 Pełny tekst Zeszyty Naukowe. Organizacja i Zarządzanie / Politechnika Śląska

    The article presents rules, requirements, and norms for quality management and health safety assurance systems among small and medium bakeries. This group of businesses does not have the obligation of implementing or certifying specific systems. They are, however, implemented in order to increase the quality of the bread or reach a better market position. Also, the results of a 2022 study of 53 bakeries’ implementation of individual quality management systems are presented in the paper. The study shows an important role of the implementation of coordinated systems in the increase of quality of bread. Theoretical considerations and the results of a questionnaire study allowed the author to discuss and explain why neither the TQM system nor the BRC standards were implemented in small- and medium- sized bakeries. The results of research on the implementation of quality management systems and ensuring the health safety of bread confirm the legitimacy of using integrated quality systems. They will have a fundamental impact in the long-term perspective of innovative management of bakery managers and owners.

  • Improved methods for stator end winding leakage inductance calculation
    • Grzegorz Kostro
    • Michał Michna
    • Filip Kutt
    • Roland Ryndzionek
    2023 Pełny tekst COMPEL-THE INTERNATIONAL JOURNAL FOR COMPUTATION AND MATHEMATICS IN ELECTRICAL AND ELECTRONIC ENGINEERING

    Calculating the stator end-winding leakage inductance, taking into account the rotor, is difficult due to the irregular shape of the end-winding. The end-winding leakage may distribute at the end of the active part and the fringing flux of the air gap. The fringing flux belongs to the main flux but goes into the end-winding region. Then, not all the magnetic flux occurring in the end region is the end-winding leakage flux. The purpose of this paper was to find a method to accurately separate the leakage from the total flux, taking into account the rotor.

  • Improved-Efficacy EM-Driven Optimization of Antenna Structures Using Adaptive Design Specifications and Variable-Resolution Models
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    2023 IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION

    Optimization-driven parameter tuning is an essential step in the design of antenna systems. Although in many cases it is still conducted through parametric studies, rigorous numerical methods become a necessity if truly optimum designs are sought for, and the problem intricacies (number of variables, multiple goals, constraints) make the interactive approaches insufficient. The two practical considerations of electromagnetic (EM)-driven optimization are reliability and computational cost. Repetitive EM simulations may incur unmanageable expenses, whereas the lack of a decent starting point or objective function multimodality may prevent the numerical procedures (especially the local ones) from identifying satisfactory designs. In pursuit of reliability improvements, a design specification adjustment procedure has been recently proposed that improves the immunity of local search procedures to poor starting points. Therein, the objective function is modified by relocating the design goals (e.g., center frequencies) closer to the actual operating parameters of the antenna at the current design, to make them attainable through local search. The goals are then gradually adjusted and converge to the original targets towards then end of the optimization process. In this paper, we introduce an algorithm for reliable and low-cost antenna tuning that capitalizes on the specification management scheme while embedding it in variable-resolution optimization framework. In our approach, the EM model fidelity is adaptively adjusted based on the misalignment between the actual and target operating conditions, as well as the convergence status of the algorithm. By initiating the search process from the lowest-fidelity model (gradually dialed up to the highest-fidelity one), considerable computational savings of almost sixty percent can be achieved, with respect to the single-fidelity procedure. The speedup is possible without compromising reliability of the optimization process, as demonstrated using three examples of microstrip antennas, designed under different and challenging scenarios.