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Gdańsk University of Technology

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Publications from the year 2023

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  • HEALTH MONITORING OF A COMPRESSION IGNITION ENGINE FED WITH DIFFERENT LOW-SULPHUR MARINE FUELS BY ENDOSCOPIC IMAGE PROCESSING AND ANALYSIS
    • Zbigniew Korczewski
    2023 Full text Polish Maritime Research

    This article characterises the methodology for the endoscopic testing of a laboratory diesel engine used for testing marine fuels. The ‘Shadow’ measurement method used in the XLG3 type EVEREST digital endoscope, for quantitative and qualitative identification of detected surface defects, was approximated. Representative endoscopic images of the elements limiting the working space of the research engine are demonstrated, having been recorded during the usable quality testing of newly produced, low-sulphur marine fuels, so-called ‘modified fuels’. The main purpose of the endoscopic examinations was the final verification of the tested fuel’s suitability for feeding full-size marine engines.

  • Healthy financial system of local government on the example of Poland
    • Maria Jastrzębska
    2023 Full text Financial Law Review

    healthy local government financial system lays the foundation for the ability of local government units (LGUs) to carry out public tasks at the current qualitative and quantitative level and to meet their obligations in the short and long term. A healthy financial system of local government is a system that is adequate, stable, unified, consistent, transparent, diversified, counter-cyclical, guarantees the financial independence of LGUs, and activates to take measures to increase revenues and efficiency of expenditures. The purpose of the article is to answer the question of what are the characteristics of a healthy financial system of local self-government, assess the system operating in Poland, and formulate recommendations for changes aimed at healing this system. Descriptive analysis, comparative analysis, inductive and deductive reasoning, and critical analysis of the national literature on the subject by economists and lawyers were used.

  • Heat transfer enhancement of modular thermal energy storage unit for reversible heat pump cooperation
    • Rafał Andrzejczyk
    • Tomasz Muszyński
    • M. Fabrykiewicz
    • Michał Rogowski
    2023 INTERNATIONAL JOURNAL OF THERMAL SCIENCES

    The following article presents experimental comparison research on a hexagonal shelland-tube latent thermal energy storage (TES). Such shape of a shell was deliberately chosen instead of a cylindrical one due to its high modularity and with intent for future applications in automobiles (EV and PHEV) air conditioning systems (HVAC). Two geometries of helical coils, acting as tubes, were studied in this article. One was a simple helical coil with a small pitch. The other one was a helical coil with a larger pitch but enhanced with six longitudinal fins for each corner of the hexagon. Fins were added to study the effects of higher heat transfer area as well as effects of better thermal penetration of the Phase Change Material (PCM). Geometries of coils were matched with intent to occupy the same volume in the storage tank for a better comparison of the results. Results were also compared with previous studies carried out by authors for a copper pipe placed in a cylindrical shell. PCM chosen for this study was RT18HC due to its high value of latent heat and the melting temperature close to 18◦C. Melting temperature value is crucial for applications in vehicle thermal control systems.

  • Heat Transfer of the Multicolor-Laser-Sources-Irradiated Nanoparticles in Reference to Thermal Processes
    • Piotr Radomski
    • Federica Zaccagnini
    • Paweł Ziółkowski
    • Francesca Petronella
    • Luciano de Sio
    • Dariusz Mikielewicz
    2023 Full text

    Unlike the standard materials, metallic nanoparticles offer enhancing the heat convertion rate which implies the maximum and average temperature boost significantly in the considered system. The work’s purpose is to examine heat transfer in the metallic nanoparticles which have been deposited on a glassy substrate, enabling the nanostructures thermoablation. Furthermore, the functionalized substrate is irradiated with multicolor-laser-sources, with a future perspective to develop a solar model. This is particularly crucial at improving efficiency in solar-collectors-based renewable energy sources. On the other hand, the theoretical investigations which have been previously verified for a single laser source aim to demonstrate the unsteady temperature and entropy increase in selected geometry cross-sections. The produced heat and the appropriate boundary conditions are calculated based on the advanced optics (Mie-Lorentz and Rayleigh-Drude theories) using an analytical approach. On the other hand, the temperature field and entropy production for the case study is being achieved via CFD simulations. The obtained results will be subsequently being applied in order to optimize the appropriate nanoparticle size and shape in operational work conditions.

  • Heterojunction of (P, S) co-doped g-C3N4 and 2D TiO2 for improved carbamazepine and acetaminophen photocatalytic degradation
    • Elvana Çako
    • Szymon Dudziak
    • Paweł Głuchowski
    • Grzegorz Trykowski
    • Marcin Pisarek
    • Agnieszka Fiszka Borzyszkowska
    • Karol Sikora
    • Anna Zielińska-Jurek
    2023 Full text SEPARATION AND PURIFICATION TECHNOLOGY

    Novel photocatalysts of phosphorus and sulfur co-doped graphitic carbon nitride incorporated in 2D TiO2 structure were successfully fabricated and applied for solar-driven degradation of emerging pollutants from the group of pharmaceuticals not susceptible to biodegradation. The hybrid photocatalysts with different loadings of (P, S)-doped g-C3N4 were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV–vis diffuse reflectance spectroscopy (DR/UV–vis), photoluminescence (PL) spectroscopy, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and transmission electron microscopy (TEM). The optimum (P, S)-doped g-C3N4/TiO2 (5 %) composite revealed improved photocatalytic activity towards the degradation of carbamazepine and acetaminophen. For CBZ, about 100 % degradation was achieved in less than 30 min of photodegradation, whereas for ACT, the complete removal was observed in 60 min of irradiation under simulated solar light. The multi-anion doped g-C3N4/2D TiO2 composite demonstrated an excellent synergy towards the degradation of CBZ and ACT with a synergy index of 1.35 and 1.62. Moreover, the mineralization efficiency measured as TOC removal was 76 % and 40 % for CBZ and ACT, respectively. The reactive oxygen species responsible for the degradation of selected pharmaceuticals are superoxide (•O2– ) and hydroxyl radicals (HO•), and the kinetics of reactions proved to fit the first-order kinetics with a rate constant of 0.21 min 1 for CBZ degradation and 0.074 min 1 for ACT degradation. Our results suggest that (P, S)-doped g-C3N4/ 2D TiO2 heterostructure is a Z-scheme heterojunction, which can effectively separate photogenerated charge carriers. The emissions and decay times analyzed for single components and the optimal (P, S)-doped g-C3N4/ 2D TiO2 (5 %) composite confirmed interfacial charge transfer between TiO2 nanosheets and (P, S)-g-C3N4 and more effective separation of electron-hole pairs. Identification of carbamazepine and acetaminophen intermediates was performed using LC-MS analysis in combination with additional DFT calculations of the possible by-products formation. Regarding reusability, the photocatalytic activity of (P, S)-doped g-C3N4/ 2D TiO2 (5 %) was stable after subsequent cycles of carbamazepine and acetaminophen degradation.

  • 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 Full text 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 Full text 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 Full text 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 Full text 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 Full text 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 Full text 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 Full text 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 Full text 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 Full text 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 Full text 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 Full text

    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.