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Politechniki Gdańskiej

Publikacje z roku 2023

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  • Evaluating aerial laser scanning for seafloor mapping automation Shallow seabed mapping based on airborne Lidar bathymetry
    • Łukasz Janowski
    • Paweł Tysiąc
    • Agnieszka Kubowicz
    2023 GIM International-The Worldwide Magazine for Geomatics

    This article presents a novel methodological approach to understand and assess the suitability of ALB for the automatic classification and mapping of the seabed. ALB allows recording of the depth below the Secchi disk.


  • Evaluating Gelatin-Based Films with Graphene Nanoparticles for Wound Healing Applications
    • Piotr Kamedulski
    • Marcin Wekwejt
    • Lidia Zasada
    • Anna Ronowska
    • Anna Michno
    • Dorota Chmielniak
    • Paweł Binkowski
    • Jerzy P. Lukaszewicz
    • Beata Kaczmarek-Szczepańska
    2023 Pełny tekst Nanomaterials

    In this study, gelatin-based films containing graphene nanoparticles were obtained. Nanoparticles were taken from four chosen commercial graphene nanoplatelets with different surface areas, such as 150 m2/g, 300 m2/g, 500 m2/g, and 750 m2/g, obtained in different conditions. Their morphology was observed using SEM with STEM mode; porosity, Raman spectra and elemental analysis were checked; and biological properties, such as hemolysis and cytotoxicity, were evaluated. Then, the selected biocompatible nanoparticles were used as the gelatin film modification with 10% concentration. As a result of solvent evaporation, homogeneous thin films were obtained. The surface’s properties, mechanical strength, antioxidant activity, and water vapor permeation rate were examined to select the appropriate film for biomedical applications. We found that the addition of graphene nanoplatelets had a significant effect on the properties of materials, improving surface roughness, surface free energy, antioxidant activity, tensile strength, and Young’s modulus. For the most favorable candidate for wound dressing applications, we chose a gelatin film containing nanoparticles with a surface area of 500 m2/g.


  • Evaluating the risk of endometriosis based on patients’ self-assessment questionnaires
    • Krystian Zieliński
    • Dajana Drabczyk
    • Michał Kunicki
    • Damian Drzyzga
    • Anna Kloska
    • Jacek Rumiński
    2023 Pełny tekst Reproductive Biology and Endocrinology

    Background Endometriosis is a condition that significantly affects the quality of life of about 10 % of reproductive-aged women. It is characterized by the presence of tissue similar to the uterine lining (endometrium) outside the uterus, which can lead lead scarring, adhesions, pain, and fertility issues. While numerous factors associated with endometriosis are documented, a wide range of symptoms may still be undiscovered. Methods In this study, we employed machine learning algorithms to predict endometriosis based on the patient symptoms extracted from 13,933 questionnaires. We compared the results of feature selection obtained from various algorithms (i.e., Boruta algorithm, Recursive Feature Selection) with experts’ decisions. As a benchmark model architecture, we utilized a LightGBM algorithm, along with Multivariate Imputation by Chained Equations (MICE) and k-nearest neighbors (KNN), for missing data imputation. Our primary objective was to assess the model’s performance and feature importance compared to existing studies. Results We identified the top 20 predictors of endometriosis, uncovering previously overlooked features such as Cesarean section, ovarian cysts, and hernia. Notably, the model’s performance metrics were maximized when utilizing a combination of multiple feature selection methods. Specifically, the final model achieved an area under the receiver operator characteristic curve (AUC) of 0.85 on the training dataset and an AUC of 0.82 on the testing dataset. Conclusions The application of machine learning in diagnosing endometriosis has the potential to significantly impact clinical practice, streamlining the diagnostic process and enhancing efficiency. Our questionnaire-based prediction approach empowers individuals with endometriosis to proactively identify potential symptoms, facilitating informed discussions with healthcare professionals about diagnosis and treatment options.


  • Evaluation and cellular responses of modulators of TRF1/TRF2 protein’s function as potential anticancer drugs interfering with telomeric shelterin’s function
    • Wioletta Brankiewicz
    2023 Pełny tekst

    A number of proteins that interact with telomeres have been identified in human cells, indicating the high plasticity of human nucleoprotein complex organization. The most important complex is the "shelterin" complex, which consists of six proteins: TRF1, TRF2, TIN2, POT1, TPP1. The TRF1 and TRF2 directly bind to telomeric double-stranded DNA and the TIN2 protein. The TIN2 protein also binds to the TPP1 protein, stabilizing the structure of the entire "shelterin" complex. The PhD thesis presents the characterization of the effect of eleven small molecule compounds (B070, B087, B176, B280, B327, A822, A378, A670, A628, ST50, ST2S), which were designed in silico as potential inhibitors of interactions between TRF1-TIN2 and TRF2-TIN2 proteins. Human breast cancer cell lines were used for the studies: MDA-MB-231 (ER/PR-; HER2/Neu-), BT-20 (ER/PR-; HER2/Neu-), SK-BR-3 (ER/PR-; HER2/Neu+), BT-474 (ER/PR+; HER2/Neu+), MCF-7 (ER/PR+; HER2/Neu-) and T47D (ER/PR+; HER2/Neu), which represent the basic molecular subtypes of breast cancer. Experiments were also carried out on primary HMEC cells and material from patients (invasive ductal breast cancer, ER/PR+; HER2/Neu-). Based on the results obtained using molecular biology methods - starting from toxicity tests, through the advanced technique of fluorescent staining using confocal microscopy and SPR technique - two compounds (A822 and B327) were identified as promising, which were included in a patent application.


  • Evaluation and rationale of the performance of several elastomeric composites incorporating devulcanized EPDM
    • X. Colom
    • F. Carrillo-Navarrete
    • Mohammad Saeb
    • Marc Marín-Genescà
    • Krzysztof Formela
    • J Canavate
    2023 Pełny tekst POLYMER TESTING

    thylene Propylene Diene rubber (EPDM), is present in many applications. However, its crosslinked structure makes difficult its recycling. The use of devulcanized EPDM, (dEPDM) as a component of elastomeric composites, is a real possibility to reuse EPDM scraps. In this study, three matrices (natural rubber (NR), styrene butadiene rubber (SBR) and EPDM rubber) have been tested including devulcanized EPDM as a recycled component. The EPDM previously was devulcanized using a thermomechanical process followed by microwave irradiation. The resulting devulcanized EPDM was blended with the matrixes and then the new compound was vulcanized again. The samples showed a general increase of their mechanical properties and their thermal stability specially marked for NR and SBR. Compositions including about 40 phr dEPDM within the EPDM matrix exhibited a difference in their general behavior that it was manifested by a general decrease in properties compared with lower amounts of dEPDM. In order to further understand this behavior, the samples were analyzed in terms of cross-link density, swelling degree, and scanning electron microscopy. The study of the microstructure of the samples indicated that microagglomerates of dEPDM are formed inside the samples. In case of NR or SBR the agglomerates were very linked to the matrix through the covalent bonds established in the crosslinking process. In the case of the EPDM matrix, the agglomerates presented less interfacial cross-links. The cross-linking takes place preferentially within the dEPDM microdomains and this results in a relative decrease in mechanical properties and thermal stability when compared to NR and SBR.


  • Evaluation of adhesion strength, corrosion, and biological properties of the MWCNT/TiO2 coating intended for medical applications
    • Dorota Rogala-Wielgus
    • Beata Majkowska-Marzec
    • Andrzej Zieliński
    • Katarzyna Roszek
    • Malwina Liszewska
    2023 Pełny tekst RSC Advances

    Multi-wall carbon nanotube (MWCNT) coatings are gaining increasing interest because of their special properties used in many science fields. The titania coatings are known for their improvement of osteoblast adhesion, thus changing the surface architecture. Bi-layer coatings comprising 0.25 wt% of the MWCNTs and 0.30 wt% of titania (anatase structure) were synthesized in a two-stage procedure using the electrophoretic deposition method (EPD). The MWCNT and TiO2 coatings were deposited with voltage and time parameters, respectively, of 20 V and 0.5 min, and 50 V and 4 min. EDS, AFM, SEM, Raman spectroscopy, nano-scratch test, potentiodynamic corrosion tests, wettability studies, and cytotoxicity determined with MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) test on human dermal fibroblasts (HDF) and mouse osteoblast precursors (MC3T3), and lactate dehydrogenase (LDH) activity test were carried out on examined surfaces. The prepared MWCNT/TiO2 coating is uniformly distributed by MWCNTs and agglomerated by TiO2 particles of size ranging from 0.1 to 3 mm. Raman spectroscopy confirmed the anatase structure of the TiO2 addition and showed typical peaks of the MWCNTs. The MWCNT/TiO2 coating had higher roughness, higher adhesion strength, and improved corrosion resistance compared to the MWCNT basic coating. The results of biological tests proved that physicochemical properties of the surface, such as high porosity and wettability of MWCNT/TiO2-coated material, would support cell adhesion, but toxic species could be released to the culture medium, thus resulting in a decrease in proliferation.


  • Evaluation of ChatGPT Applicability to Learning Quantum Physics
    • Agata Stefańska
    • Tomasz Stefański
    • Michał Czubenko
    2023

    ChatGPT is an application that uses a large language model. Its purpose is to generate answers to various questions as well as provide information, help solve problems and participate in conversations on a wide range of topics. This application is also widely used by students for the purposes of learning or cheating (e.g., writing essays or programming codes). Therefore, in this contribution, we evaluate the ability of ChatGPT to answer questions in quantum physics. That is, we develop a benchmark consisting of ten questions, whose difficulty is measured on a ten-grade scale. Then ChatGPT answers are evaluated and discussed. In this way, we can measure how well quantum-physics information is processed by this application. Our results demonstrate that ChatGPT does not notice subtle differences between physical terms, and can provide wrong answers to quantum-physics-related questions. It can also provide false mathematical formulas, claim that they are correct and confirm its answers. Note that this AI application is not sure of its answers, and in seven cases it apologizes for the first answer when a user has negated it. To sum up, AI represented by ChatGPT is only able to support students in the process of learning quantum physics at the fundamental level. Moreover, during collective exams in the future, where cheating and the use of AI by students may occur, exam questions should not be descriptive, but should be focused on solving computational problems.


  • Evaluation of electrosynthesized reduced graphene oxide–Ni/Fe/Co-based (oxy)hydroxide catalysts towards the oxygen evolution reaction
    • Karolina Cysewska
    • Marcin Łapiński
    • Marcin Zając
    • Jakub Karczewski
    • Piotr Jasiński
    • Sebastian Molin
    2023 Pełny tekst Beilstein Journal of Nanotechnology

    In this work, the specific role of the addition of graphene oxide (GO) to state-of-the-art nickel–iron (NiFe) and cobalt–nickel–iron (CoNiFe) mixed oxides/hydroxides towards the oxygen evolution reaction (OER) is investigated. Morphology, structure, and OER catalytic activity of the catalysts with and without GO were studied. The catalysts were fabricated via a two-step electrodeposition. The first step included the deposition of GO flakes, which, in the second step, were reduced during the simultaneous deposition of NiFe or CoNiFe. As a result, NiFe-GO and CoNiFe-GO were fabricated without any additives directly on the nickel foam substrate. A significant improvement of the OER activity was observed after combining NiFe with GO (OER overpotential η(10 mA·cm−2): 210 mV) compared to NiFe (η: 235 mV) and GO (η: 320 mV) alone. A different OER activity was observed for CoNiFe-GO. Here, the overall catalytic activity (η: 230 mV) increased compared to GO alone. However, it was reduced in comparison to CoNiFe (η: 224 mV). The latter was associated with the change in the morphology and structure of the catalysts. Further OER studies showed that each of the catalysts specifically influenced the process. The improvement in the OER by NiFe-GO results mainly from the structure of NiFe and the electroactive surface area of GO.


  • Evaluation of fire hazard in electrical installations due to unfavorable ambient thermal conditions
    • Seweryn Szultka
    • Stanisław Czapp
    • Adam Tomaszewski
    • Hayat Ullah
    2023 Pełny tekst Fire

    Evaluation of fire hazard caused by electrical installations is a difficult and important topic, and it limits the possibility of loss of life or health of people, as well as the occurrence of significant property damage. In particular, this hazard was caused by power cables and especially photovoltaic (PV) installations. The authors proved that power cables directly exposed to strong solar radiation are likely to exceed maximum permissible temperature in unfavorable ambient conditions. Overheated and damaged cable insulation can be a source of electric shock and a strong leakage current causing fire. In the case of typical PV connectors (MC4 connectors), the main problem is poor contact at the connections of the PV cables. A poor connection can even cause the connector to melt, as shown in this study. In the paper, the authors present a computer simulation regarding critical thermal points of electrical installations, in particular, of the PV type. It may be an indication of what should be paid attention to when designing and implementing such installations. This is important for the safety of people and buildings.


  • Evaluation of Linkers’ Influence on Peptide-Based Piezoelectric Biosensors’ Sensitivity to Aldehydes in the Gas Phase
    • Tomasz Wasilewski
    • Damian Neubauer
    • Marek Wojciechowski
    • Bartosz Szulczyński
    • Jacek Gębicki
    • Wojciech Kamysz
    2023 Pełny tekst INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    Recent findings qualified aldehydes as potential biomarkers for disease diagnosis. One of the possibilities is to use electrochemical biosensors in point-of-care (PoC), but these need further development to overcome some limitations. Currently, the primary goal is to enhance their metrological parameters in terms of sensitivity and selectivity. Previous findings indicate that peptide OBPP4 (KLLFDSLTDLKKKMSEC-NH2) is a promising candidate for further development of aldehyde-sensitive biosensors. To increase the affinity of a receptor layer to long-chain aldehydes, a structure stabilization of the peptide active site via the incorporation of different linkers was studied. Indeed, the incorporation of linkers improved sensitivity to and binding of aldehydes in comparison to that of the original peptide-based biosensor. The tendency to adopt disordered structures was diminished owing to the implementation of suitable linkers. Therefore, to improve the metrological characteristics of peptide-based piezoelectric biosensors, linkers were added at the C-terminus of OBPP4 peptide (KLLFDSLTDLKKKMSE-linker-C-NH2). Those linkers consist of proteinogenic amino acids from group one: glycine, L-proline, L-serine, and non proteinogenic amino acids from group two: β-alanine, 4-aminobutyric acid, and 6-aminohexanoic acid. Linkers were evaluated with in silico studies, followed by experimental verification. All studied linkers enhanced the detection of aldehydes in the gas phase. The highest difference in frequency (60 Hz, nonanal) was observed between original peptide-based biosensors and ones based on peptides modified with the GSGSGS linker. It allowed evaluation of the limit of detection for nonanal at the level of 2 ppm, which is nine times lower than that of the original peptide. The highest sensitivity values were also obtained for the GSGSGS linker: 0.3312, 0.4281, and 0.4676 Hz/ppm for pentanal, octanal, and nonanal, respectively. An order of magnitude increase in sensitivity was observed for the six linkers used. Generally, the linker’s rigidity and the number of amino acid residues are much more essential for biosensors’ metrological characteristics than the amino acid sequence itself. It was found that the longer the linkers, the better the effect on docking efficiency.


  • Evaluation of long‑term immunity and protection against T. gondii after immunization with multivalent recombinant chimeric T. gondii proteins
    • Maciej Chyb
    • Bożena Dziadek
    • Katarzyna Dzitko
    • Bartłomiej Tomasz Ferra
    • Malwina Kawka
    • Lucyna Holec-Gąsior
    • Justyna Gatkowska
    2023 Pełny tekst Scientific Reports

    Toxoplasmosis caused by the opportunistic, cosmopolitan protozoan Toxoplasma gondii is one of the most common parasitoses in the world. Although it may prove dangerous or even fatal for immunocompromised individuals, immunoprophylaxis for humans is still nonexistent. Thus, the aim of the current work was to assess the ability of two immunogenic recombinant chimeric T. gondii proteins, SAG2-GRA1-ROP1 (SGR) and SAG1-MIC1-MAG1-GRA2 (SMMG), selected in previous experiments to induce long-lasting immunity when administered with a safe adjuvant. Thus, the determination of immunological parameters and parasite challenge were performed both two weeks after the last boost injection and 6 months postvaccination. Both experimental vaccines triggered specific humoral and cellular responses in immunized C3H/HeOuJ male mice, characterized by the production of specific IgG (IgG1/IgG2a) antibodies in vivo and the synthesis of key Th1/Th2 cytokines by Toxoplasma lysate antigen-stimulated splenocytes in vitro. Although the levels of specific antibodies and cytokine release were in most cases lower six months postimmunization, the protection rates conferred by the vaccination were comparable regardless of the time after the administration of the last vaccine dose. The results indicate that both preparations induce long-lasting immunity, which makes them attractive candidates for further research aimed at boosting their immunogenicity and immunoprotective capacity.


  • Evaluation of structural and electrical properties of multicomponent spinel oxide thin films deposited via spray pyrolysis technique
    • Bartosz Kamecki
    • Jakub Karczewski
    • Grzegorz Cempura
    • Piotr Jasiński
    • Sebastian Molin
    2023 Pełny tekst MATERIALS CHARACTERIZATION

    This work reports the preparation of (Mn,Co,Fe,Ni,Cr)3O4 high-entropy spinel oxide in the form of a ~ 500 nm thin film utilising a facile spray pyrolysis technique. The structural and electrical properties of the layers were characterised after exposure to temperatures in the range of 400–900 ◦C. The as-deposited layers were amorphous, and crystallised upon heat treatment at 500 ◦C. Microstructural analyses proved a homogeneous elemental distribution and the desired Fd-3 m cubic spinel structure. Electrical conductivity measurements indicated a dependence on the processing temperature, with the highest electrical conductivity values (~3 S cm 1 at 700 ◦C) obtained for layers heat-treated at 700 ◦C. The spray pyrolysis technique seems to be well suited to fabricating and exploring spinel-based high-entropy oxides synthesized as thin films, and to studying new compositions containing transition metal cations.


  • Evaluation of the energy efficiency of electric vehicle drivetrains under urban operating conditions
    • Jacek Kropiwnicki
    • Tomasz Gawłas
    2023 Pełny tekst Combustion Engines

    In electric vehicles, as in hybrids vehicles, a very important factor affecting the energy efficiency of the powertrain is the ability to use the regenerative braking energy. Depending on the settings available in electric vehicles, the driver can choose different modes of operation: switch off the regenerative braking mode altogether, select the intensity of regenerative braking, or leave the control system in automatic mode. The last mode is often the only one available on eclectic vehicles, so the driver cannot decide whether to switch off or increase intensity of the regenerative braking. This paper presents a new method for evaluating the energy efficiency of electric vehicle powertrains under urban operating conditions. The presented method uses a procedure for mapping the operating conditions allowing to determine the reference level of energy consumption in relation to those recorded during the identification tests. Identification tests were carried out in the Tri-City area using electric vehicles of different purposes and operating parameters. Performed tests allowed to evaluate the regenerative braking efficiency of tested vehicle, which varies over a relatively wide range, for vehicle A from 33 to 77%, for vehicle B from 27 to 55% and for vehicle C from 36 to 58%. It can be concluded that one of the main factors determining the regenerative braking efficiency is the level of state of charge of the accumulator and the management algorithm used by the vehicle for controlling this parameter.


  • Evaluation of the influence of the opening pressure of a marine Diesel engine injector on the results of numerical simulation of the working cycle and their comparison with the results of the laboratory experiment
    • Patrycja Puzdrowska
    2023 Pełny tekst Combustion Engines

    The article presents the results of a numerical simulation of the working process carried out in a diesel engine. In the applied utility program DIESEL-RK, the laboratory engine Farymann Diesel type D10 was implemented. A selected inoperability of its functional fuel supply system - reduced opening pressure of the injector pinj - was introduced. The values of adequate diagnostic parameters were determined: working gas temperature in the cylinder Tcyl, exhaust gas temperature Texh, combustion (flame) temperature Tcomb and concentration of nitrogen oxides in the exhaust gas NOx. Experimental tests were carried out on the experimental engine with the inoperative condition actually introduced, analogous to the numerical simulation, and the diagnostic parameters Texh and NOx were recorded. The results obtained by numerical simulation of the processes and during the active experiment on the experimental engine were compared.


  • EVALUATION OF THE USE OF M2M-TYPE NB-IoT AND LTE TECHNOLOGIES FOR MARITIME COMMUNICATION SYSTEMS
    • Sławomir Gajewski
    • Agnieszka Czapiewska
    • Małgorzata Gajewska
    2023 Pełny tekst Polish Maritime Research

    The development of IoT (the Internet of Things) wireless transmission opens a new era in communication systems. In the next years, the development and implementation of IoT systems will be very dynamic. It can be seen that the solutions of LTE – NB-IoT (Long Term Evolution – Narrowband IoT) transmission devices are implemented in a wide range of terrestrial solutions, e.g. smart grids. This paper aims to analyse the possibility of the use of NB-IoT technology for maritime communication applications and partially, for some maritime safety solutions, based on signal coverage analysis at sea. An interesting approach is the comparison of the results of NB-IoT coverage to the classic cellular LTE based communication systems. Proposed solutions are based on the practical implementation of a designed specialised data concentrator with implemented gateway and radio modems, for both NB-IoT technology as well as LTE. In the paper, analyses of radio link budget and propagation loss models for sea environment are presented. The coverage analysis is based on real measurements of the efficiency of transmissions using wireless modems implemented in the developed data concentrator.


  • Evaluation of the yield, chemical composition and biological properties of essential oil from bioreactor-grown cultures of Salvia apiana microshoots
    • Agata Krol
    • Adam Kokotkiewicz
    • Marcin Gorniak
    • Aleksandra M. Naczk
    • Bożena Zabiegała
    • Jakub Gebalski
    • Filip Graczyk
    • Daniel Zaluski
    • Adam Bucinski
    • Maria Luczkiewicz
    2023 Pełny tekst Scientific Reports

    Microshoot cultures of the North American endemic Salvia apiana were established for the first time and evaluated for essential oil production. Stationary cultures, grown on Schenk-Hildebrandt (SH) medium, supplemented with 0.22 mg/L thidiazuron (TDZ), 2.0 mg/L 6-benzylaminopurine and 3.0% (w/v) sucrose, accumulated 1.27% (v/m dry weight) essential oil, consisting mostly of 1,8-cineole, β-pinene, α-pinene, β-myrcene and camphor. The microshoots were adapted to agitated culture, showing biomass yields up to ca. 19 g/L. Scale-up studies demonstrated that S. spiana microshoots grow well in temporary immersion systems (TIS). In the RITA bioreactor, up to 19.27 g/L dry biomass was obtained, containing 1.1% oil with up to ca. 42% cineole content. The other systems employed, i.e. Plantform (TIS) and a custom made spray bioreactor (SGB), yielded ca. 18 and 19 g/L dry weight, respectively. The essential oil content of Plantform and SGB-grown microshoots was comparable to RITA bioreactor, however, the content of cineole was substantially higher (ca. 55%). Oil samples isolated from in vitro material proved to be active in acetylcholinesterase (up to 60.0% inhibition recorded for Plantform-grown microshoots), as well as hyaluronidase and tyrosinase-inhibitory assays (up to 45.8 and 64.5% inhibition observed in the case of the SGB culture).


  • Evaluation of thermal cracking probability for asphalt concretes with high percentage of RAP
    • Mariusz Jaczewski
    • Marek Pszczoła
    • Jacek Alenowicz
    • Dawid Ryś
    • Bohdan Dołżycki
    • Piotr Jaskuła
    2023 CONSTRUCTION AND BUILDING MATERIALS

    The paper presents determination of the probability of thermal cracking of asphalt mixtures with different reclaimed asphalt pavement (RAP) content on the basis of laboratory tests and analytical evaluation using thermal stress development method. Probability was evaluated taking into consideration: the type and gradation of the mixture and the quality and content of RAP. Thermal stresses were determined using two models: elastic and viscoelastic. Addition of RAP decreases the low-temperature properties of all the tested asphalt mixtures. In the case of wearing and binder courses, addition of 20% of RAP increases the cracking temperature by around 5–6 ◦C.


  • Evaluation of VSC Impact on Power System Using Adequate P-Q Capability Curve
    • Michal Brodzicki
    • Jacek Klucznik
    • Stanisław Czapp
    2023 Pełny tekst Electronics

    Renewable energy sources, which are becoming increasingly popular, often use a voltage source converter (VSC) for connection to the power system. Assessing the effects of connecting such a source to the power system is essential to ensure the proper operation of the power system and the connected source. For this purpose, it is necessary to know the range of active and reactive power generation by the converter. The authors indicate that the interaction between the power system and the converter affects its range of available active and reactive power. Therefore, a strictly defined range of the converter’s generating capability should not be assumed as invariant, but its capability for a given operating condition of the power system should be determined iteratively. In order to confirm this thesis, the authors analyzed the operation of the VSC-based energy source in an example power system using the PowerFactory software. Extending the calculation procedure to include iterative determination of the converter’s available power range showed a significant influence of the system’s operating state on the converter’s generating capabilities. The results obtained in this work extend the knowledge, and thanks to them, the operation of VSC systems can be modelled more accurately.


  • Event-Triggered Communication in Cooperative, Adaptive Model Predictive Control of a Nuclear Power Plant’s Turbo–Generator Set
    • Pawel Sokolski
    • Tomasz Rutkowski
    • Bartosz Ceran
    • Daria Złotecka
    • Dariusz Horla
    2023 Pełny tekst ENERGIES

    This paper discusses the issue of optimizing the communication between the components of a cooperating control system formed by a pair of MPC controllers of a nuclear power plant turbine set using online recursive least squares identification. It is proposed to use event-triggered communication, i.e., sending information only at selected time instants, as opposed to the standard approach where communication is triggered by time (time-triggered approach). The aim of this paper is to propose a change in the method of information exchange in the case of asynchronous communication between control system components and to prove its suitability for the selected application. Resignation from continuous communication in favor of sending information only at selected moments allows the load on the communication network to be reduced by approximately 90% while maintaining the quality of control.


  • Evolution of Physical Properties of RE 3 Ni 5 Al 19 Family (RE = Y, Nd, Sm, Gd, Tb, Dy, Ho, and Er)
    • Zuzanna Ryżyńska
    • Madalynn Marshall
    • Weiwei Xie
    • Tomasz Klimczuk
    • Michał Winiarski
    2023 Pełny tekst CRYSTAL RESEARCH AND TECHNOLOGY

    Single crystals of RE3Ni5Al19 series (RE = Y, Nd, Sm, Gd, Tb, Dy, Ho, and Er) are grown using the Al self-flux method. The crystal structure is examined by both single crystal and powder X-ray diffraction. Physical properties are studied for the first time for RE3Ni5Al19 (RE = Y, Nd, Gd, Tb, Dy, Ho, and Er) by means of magnetic susceptibility, electrical resistivity, and heat capacity measurements. Complex magnetic behaviors, with up to three transitions present for RE = Sm, Gd, Tb, and Dy, are revealed. Y3Ni5Al19 is found to be a nonmagnetic nonsuperconducting metal (above T = 1.8 K) with weak electron–phonon coupling strength.