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Repozytorium publikacji
Politechniki Gdańskiej

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  • Miłość
    • Krzysztof Wróblewski
    2022

    Miłość Czymkolwiek jest - uczuciem dodającym skrzydeł, niszczącą siłą, miłością fizyczną, platoniczną, narcystyczną, do ludzi, do świata czy do „trzech pomarańczy” - bez jej inspiracji nie byłoby sztuki. Co prawda, teraz wystarczy kliknąć odpowiedni emotikon i już mamy obrazek miłości, wybieramy sobie emocje i przesłanie. Ale dzisiaj, w obliczu wojny i krzywdy wyrządzanej niewinnym, hasło „miłość” nie brzmi banalnie ani patetycznie, bo to z niej bierze się siła, która każe ludziom czynić dobro, pomagać innym wbrew wszystkiemu, przezwyciężając własną słabość i strach. Niech sztuka, oparta na takiej inspiracji, będzie sprzymierzeńcem dobra.

  • Mineral Composition of Dietary Supplements-Analytical and Chemometric Approach
    • Joanna Brzezińska-Rjek
    • Małgorzata Rutkowska
    • Justyna Brzezicha
    • Piotr Konieczka
    • Magdalena Prokopowicz
    • Małgorzata Grembecka
    2022 Pełny tekst Nutrients

    There is a lack of data on the actual composition and effectiveness of beetroot-based dietary supplements. The research aimed to determine the profile of 22 elements (Na, K, Ca, Mg, P, Fe, As, Se, Zn, Cu, Ag, Co, Ni, Mo, Al, Mn, Sr, Cr, Ba, Li, Pb, Cd) in beetroot and its supplements by the microwave plasma atomic emission spectrometry (MP-AES) method. The analytical procedure was optimised and validated. The composition of both groups was compared, assessing compliance with the recommended daily doses for the chosen elements, and the health risk was estimated. Furthermore, chemometric analysis was applied. Beetroots constituted a significant source of elements, especially K, Na, Mg, Ca, P, in contrast to supplements which contained their negligible amounts except from iron-enriched products which provided notable amounts of Fe (38.3–88% of the Recommended Dietary Allowance for an adult male from 19 to 75 years old). Some products were significantly contaminated with toxic elements (As, Cd). Factor and cluster analyses were helpful in the differentiation of beetroot and its supplements in view of their type (vegetable, supplement, iron-enriched supplement), origin, type of cultivation (conventional, organic), and form (capsule, tablet) based on their mineral composition. The obtained results indicate the need for more stringent control of supplements, as they may pose a significant health risk to consumers.

  • Miniaturized, green salting-out liquid–liquid microextraction coupled with GC–MS used to evaluate biogenic amines in wine samples
    • Magdalena Fabjanowicz
    • Anna Różańska
    • Kaja Kalinowska
    • Justyna Płotka-Wasylka
    2022 Pełny tekst MICROCHEMICAL JOURNAL

    Monitoring of the biogenic amines (BAs) content in food products, including wine, is important due to the health and safety of consumers and from the quality control point of view. In a given study, simultaneous derivatization and salting-out liquid–liquid microextraction (SALLME) coupled with GC–MS for BAs determination from wine samples was developed. For the optimization the Box-Behnken design was applied, where three independent factors were evaluated: the amount of NaCl, amount of EtAc and vortexing time. The proposed approach is characterized by good sensitivity expressed in the detection limit between 1.5 and 8.1 µg/L, good recovery on the level 84 – 106% and good reproducibility, it is fast (20 min) and easy to perform. Moreover, the BAs index (BAI) was applied in order to assess the quality of examined wines. BAI value for most of wine samples were below 2 mg/L what indicates that selected wines were of high quality.

  • Miniaturized Metal-Mountable U-shaped Inductive-Coupling-Fed UHF RFID Tag Antenna with Defected Microstrip Surface
    • Fuad Erman
    • Michał Kozieł
    • Effariza Hanafi
    • Rawan Soboh
    • Stanisław Szczepański
    2022 Pełny tekst IEEE Access

    This study presents a novel miniature ultra-high frequency (UHF) radio frequency identification (RFID) tag for metallic objects. Its arrangement includes a U-shaped feeder, which is inductively coupled to two E-type connected patches. Size reduction is achieved by means of utilizing the U-shaped feeder, and introducing a defection in the connection between the two E-type patches. The defection in the connection area between the patches modifies the current distribution by increasing the electrical length, and the antenna inductance. Furthermore, increasing the length of the U-shaped structure significantly raises the antenna inductance and, consequently, the flexibility of the structure for the impedance matching purpose. Polytetrafluoroethylene (PTFE) is employed for the fabrication of the designed tag. The tag’s size is 65 × 20 × 1.5 , and does not require any complex fabrication process such as utilization of metal vias and/or shorting stubs. It is observed that with 4W EIRP, the measured detection distance is 6.9 when it is attached onto metal sheets (20 × 20 ), and 5.54 when it is in free space. The measurement results also are in good agreement with the simulated results.

  • Minimal Sets of Lefschetz Periods for Morse-Smale Diffeomorphisms of a Connected Sum of g Real Projective Planes
    • Grzegorz Graff
    • Adrian Myszkowski
    2022 Pełny tekst

    The dataset titled Database of the minimal sets of Lefschetz periods for Morse-Smale diffeomorphisms of a connected sum of g real projective planes contains all of the values of the topological invariant called the minimal set of Lefschetz periods, computed for Morse-Smale diffeomorphisms of a non-orientable compact surface without boundary of genus g (i.e. a connected sum of g real projective planes), where g varies from 1 to 54.

  • Minimal surfaces and conservation laws for bidimensional structures
    • Victor Eremeev
    2022 Pełny tekst MATHEMATICS AND MECHANICS OF SOLIDS

    We discuss conservation laws for thin structures which could be modeled as a material minimal surface, i.e., a surface with zero mean curvatures. The models of an elastic membrane and micropolar (six-parameter) shell undergoing finite deformations are considered. We show that for a minimal surface, it is possible to formulate a conservation law similar to three-dimensional non-linear elasticity. It brings us a path-independent J-integral which could be used in mechanics of fracture. So, the class of minimal surfaces extends significantly a possible geometry of two-dimensional structures which possess conservation laws.

  • Mining Knowledge of Respiratory Rate Quantification and Abnormal Pattern Prediction
    • Piotr Szczuko
    • Adam Kurowski
    • Piotr Odya
    • Andrzej Czyżewski
    • Bożena Kostek
    • Beata Graff
    • Krzysztof Narkiewicz
    2022 Pełny tekst Cognitive Computation

    The described application of granular computing is motivated because cardiovascular disease (CVD) remains a major killer globally. There is increasing evidence that abnormal respiratory patterns might contribute to the development and progression of CVD. Consequently, a method that would support a physician in respiratory pattern evaluation should be developed. Group decision-making, tri-way reasoning, and rough set–based analysis were applied to granular computing. Signal attributes and anthropomorphic parameters were explored to develop prediction models to determine the percentage contribution of periodic-like, intermediate, and normal breathing patterns in the analyzed signals. The proposed methodology was validated employing k-nearest neighbor (k-NN) and UMAP (uniform manifold approximation and projection). The presented approach applied to respiratory pattern evaluation shows that median accuracies in a considerable number of cases exceeded 0.75. Overall, parameters related to signal analysis are indicated as more important than anthropomorphic features. It was also found that obesity characterized by a high WHR (waist-to-hip ratio) and male sex were predisposing factors for the occurrence of periodic-like or intermediate patterns of respiration. It may be among the essential findings derived from this study. Based on classification measures, it may be observed that a physician may use such a methodology as a respiratory pattern evaluation-aided method.

  • Misje i misjonarska retoryka w zarządzaniu platformami mediów
    • Jan Kreft
    2022

    Trudno o bardziej znane i poruszające zbiorową wyobraźnię przekazy cyfrowych platforma, niż zapisy ich misji. Nie tylko łatwo wyjaśniają one rolę organizacji, ale zapewniają racjonalizację tego, kto lub czym jest coś lub jak działa. Dla Facebooka, Google i wielu innych organizacji pragnących „zmienić świat na lepszy” są elementem samonapędzającego się mechanizmu utwierdzającego w słuszności obranej drogi. W przypadku cyfrowych platform mediów zapisy misji nie tytko są częścią narracji kształtujących ich tożsamość organizacyjną, ale formują misjonarski charakter organizacji. W ich przypadku dochodzi jednak do powstawania zniekształceń komunikacyjnych: pod presją osiągania podstawowych celów rynkowych tak konstruują przekazy misjne, by powstały korzystne konteksty społeczne i polityczne1. Misje są zatem formą autokreacji - misjonarskiej retoryki konfrontowanej z obawami o wpływ (władzę) platform na kulturę i przekonaniem, że ani korporacje nowych technologii i mediów, ani ich produkty nie tylko nie czynią świata jednoznacznie lepszym, ale oferują przede wszystkim uporanie się z trywialnymi problemami (PDF) J. KREFT - Misje i misjonarska retoryka. Available from: https://www.researchgate.net/publication/365476703_J_KREFT_-_Misje_i_misjonarska_retoryka [accessed Jan 25 2023].

  • Mission impossible for cellular internalization: When porphyrin alliance with UiO-66-NH2 MOF gives the cell lines a ride
    • Sepideh Ahmadi
    • Vahid Jajarmi
    • Milad Ashrafizadeh
    • Ali Zarrabi
    • Józef Haponiuk
    • Mohammad Saeb
    • Eder C. Lima
    • Mohammad Rabiee
    • Navid Rabiee
    2022 JOURNAL OF HAZARDOUS MATERIALS

    Is it possible to accelerate cell internalization by hybridization of nanomaterials? Herein we support the realization of using metal-organic frameworks (MOFs) with the assistance of rigid porphyrin structure (H2TMP) aimed at drug loading, drug release, relative cell viability, and targeted in vitro drug delivery. There are several MOFs, i.e., UiO-66-NH2 (125 ± 12.5 nm), UiO-66-NH2 @H2TMP (160 ± 14 nm), UiO-66-NH2 @H2TMP@DOX, and UiO-66-NH2 @H2TMP@DOX@RO were synthesized and characterized applying HEK-293, HT-29, MCF-7, and MCF-10A cell lines. MTT investigations proved a significantly higher relative cell viability for H2TMPaided leaf-extract-coated nanocarriers (above 62 % relative cell viability). Furthermore, the rigid H2TMP structure improved drug loading capacity by 24 % through an enhanced hydrogen bond, van der Waals, and π-π interactions. The in vitro targeted drug delivery experiments were conducted on HT-29 and MCF-7 cell lines. First, nanocarriers were treated with HT-29 cells, where UiO-66-NH2 @H2TMP@DOX@RO appeared as the best nanocarrier. Then, the selected nanocarrier was extracted from the HT-29 cell line and treated with the MCF-7 cell line. For the first time, the DOX remained inside the UiO-66-NH2 @H2TMP@DOX@RO after successful delivery to the HT-29 cell lines was observed on the MCF-7 cell line, and the second targeted drug delivery was performed. The results of this survey can enlighten the future ahead of cell internalization in MOF-based hybrid nanostructures.

  • Mitigating Traffic Remapping Attacks in Autonomous Multi-hop Wireless Networks
    • Jerzy Konorski
    • Szymon Szott
    2022 Pełny tekst IEEE Internet of Things Journal

    Multihop wireless networks with autonomous nodes are susceptible to selfish traffic remapping attacks (TRAs). Nodes launching TRAs leverage the underlying channel access function to receive an unduly high Quality of Service (QoS) for packet flows traversing source-to-destination routes. TRAs are easy to execute, impossible to prevent, difficult to detect, and harmful to the QoS of honest nodes. Recognizing the need for providing QoS security, we use a novel network-oriented QoS metric to propose a self-enforcing game-theoretic mitigation approach. By switching between TRA and honest behavior, selfish nodes engage in a noncooperative multistage game in pursuit of high QoS. We analyze feasible node strategies and design a distributed signaling mechanism called DISTRESS, under which, given certain conditions, the game produces a desirable outcome: after an upper bounded play time, honesty tends to become a selfish node’s best reply behavior, while yielding acceptable QoS to most or all nodes. We verify these findings by Monte Carlo and ns-3 simulations of static and mobile nodes.

  • Mobility’s Influence on System Loss in Off-Body BAN Scenarios
    • Manuel M. Ferreira
    • Filipe D. Cardoso
    • Sławomir Ambroziak
    • Kenan Turbić
    • Luis M. Correia
    2022

    In this paper, a measurement campaign for off body communications in an indoor environment is investigated for a set of on-body antennas. The channel impulse response was measured with the user approaching and departing from an off-body fixed antenna using two user dynamics, standing at fixed positions and walking. The processing of the measurement data allowed to evaluate system loss statistics. Different antenna configurations are classified in terms of mobility and visibility depending on the on-body antenna placement. A dependence on distance is found for the antennas with the lowest mobility (chest and head), while no significant dependence is found for the antennas with the highest mobility (arms and legs). Regarding the standard deviation of system loss, higher values are found in walking scenarios (above 2.6 dB) compared to the standing ones (below 0.6 dB); standard deviation also shows a clear dependence on mobility, 1.6 dB for walking and 0.5 dB for standing scenarios.

  • Moda na lastrico
    • Sylwia Świątek-Żołyńska
    • Maciej Niedostatkiewicz
    • Władysław Ryżyński
    2022 Builder

    W oresie renesansu posadzek betonowych typu ;astrico oraz zainteresowania tym rodzajem posadzek wśród inwestorów warto zwrócić uwagę na zagadnienia materiałowe i technologiczne w kontekście eksploatacji oraz napraw. W artykule na przywołanych przykładach przedstawiono rózne warianty napraw posadzek typu lastrico

  • Modal FEM Analysis of Ferrite Resonant Structures
    • Małgorzata Warecka
    • Grzegorz Fotyga
    • Piotr Kowalczyk
    • Rafał Lech
    • Michał Mrozowski
    • Adam Pacewicz
    • Bartlomiej Salski
    • Jerzy Krupka
    2022 IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS

    The finite-element method (FEM) is applied for modal analysis of ferrite-loaded spherical resonators. To improve the efficiency of the numerical calculations, the body-of-revolution (BOR) technique is utilized. Due to the frequency-dependent ferrite permeability, FEM leads to a nonlinear eigenvalue problem that is challenging to solve. To this end, Beyn’s method is proposed. The effectiveness of the proposed approach is confirmed by comparing with the results obtained analytically and with the measured data.

  • Model tests of cast-in-place piles formed by using different types of auger
    • Adam Krasiński
    • Paweł Więcławski
    • Mateusz Wiszniewski
    • Tomasz Kusio
    2022

    Model tests are still a popular research tool used to observe and determine the mechanisms of pile-soil interaction. Due to the significant scale effect, the results of model tests performed in the 1g system can only be analysed from the qualitative side. This article describes and presents the results of 1g pile model tests carried out for comparative purposes. There were tested the effectiveness and efficiency of various types of drilling augers forming cast-in-place piles in non-cohesive soil. The SDP and prototype DPDT augers were mainly tested. The tests were performed in fine, moist and fully saturated sand. The screwing resistance of individual drills and Q-s characteristics of pile models were analysed, with its division into the shaft and base resistances. Pile test results were correlated with CPT results. Comparative analyses have shown some advantages and disadvantages of the DPDT auger versus the SDP drill in relation to the screwing torque, load-bearing capacity and settlement characteristic of piles formed by both augers.

  • Model-based identification of the dominant N2O emission pathway in a full-scale activated sludge system
    • Mojtaba Maktabifard
    • Kati Blomberg
    • Ewa Zaborowska
    • Anna Mikola
    • Jacek Mąkinia
    2022 Pełny tekst JOURNAL OF CLEANER PRODUCTION

    Activated sludge models (ASMs), extended with an N2O emission module, are powerful tools to describe the operation of full-scale wastewater treatment plants (WWTPs). Specifically, such models can investigate the most contributive N2O production pathways and guide towards N2O and carbon footprint (CF) mitigation measures. A common practice is to develop and validate models using data from a single WWTP. In this study, a successfully validated model in one plant (Slupsk / Poland) was extrapolated to another full-scale WWTP (Viikinmäki / Finland). For this purpose, the previously developed ASM No. 2d with the N2O module was used. Moreover, the results of calibration and validation of that model were compared with those obtained on the basis of the ASM No. 3 with an N2O module. A novel, rigorous calibration protocol, based on the system engineering approach, was implemented to minimize the number of adjusted parameters without compromising the accuracy of model predictions. The validated model accurately predicted the behavior of the system in terms of the liquid N2O production in the bioreactor and gaseous N2O emissions. Model-based identification of N2O production pathways revealed the key role of heterotrophs duo to their high abundance in the microbial community. The N2O emission factor (EF) at the studied plant was found between 0.9 to 0.94% of the influent TN-load for the validation and calibration period, respectively. Based on the model predictions, it was estimated that the aerobic zones contributed to over 93% of the N2O emitted to the atmosphere, while the remaining portion (7%) resulted from the N2O liquid-gas transfer in the non-aerated zones. The difference between the predicted N2O EF and the empirical EF calculation would lead to almost 1000 tonnes of CO2 equivalent reduction of the annual CF of the plant, which highlights the importance of model applications in CF studies.

  • Model-free and Model-based Reinforcement Learning, the Intersection of Learning and Planning
    • Piotr Januszewski
    2022

    My doctoral dissertation is intended as the compound of four publications considering: structure and randomness in planning and reinforcement learning, continuous control with ensemble deep deterministic policy gradients, toddler-inspired active representation learning, and large-scale deep reinforcement learning costs.

  • Modeling nutrient removal and energy consumption in an advanced activated sludge system under uncertainty
    • Bartosz Szeląg
    • Adam Kiczko
    • Ewa Zaborowska
    • Giorgio Mannina
    • Jacek Mąkinia
    2022 Pełny tekst JOURNAL OF ENVIRONMENTAL MANAGEMENT

    Activated sludge models are widely used to simulate, optimize and control performance of wastewater treatment plants (WWTP). For simulation of nutrient removal and energy consumption, kinetic parameters would need to be estimated, which requires an extensive measurement campaign. In this study, a novel methodology is proposed for modeling the performance and energy consumption of a biological nutrient removal activated sludge system under sensitivity and uncertainty. The actual data from the wastewater treatment plant in Slupsk (northern Poland) were used for the analysis. Global sensitivity analysis methods accounting for interactions between kinetic parameters were compared with the local sensitivity approach. An extensive procedure for estimation of kinetic parameters allowed to reduce the computational effort in the uncertainty analysis and improve the reliability of the computational results. Due to high costs of measurement campaigns for model calibration, a modification of the Generalized Likelihood Uncertainty method was applied considering the location of measurement points. The inclusion of nutrient measurements in the aerobic compartment in the uncertainty analysis resulted in percentages of ammonium, nitrate, ortho-phosphate measurements of 81%, 90%, 78%, respectively, in the 95% confidence interval. The additional inclusion of measurements in the anaerobic compartment resulted in an increase in the percentage of ortho-phosphate measurements in the aerobic compartment by 5% in the confidence interval. The developed procedure reduces computational and measurement efforts, while maintaining a high compatibility of the observed data and model predictions. This enables to implement activated sludge models also for the facilities with a limited availability of data.

  • Modeling of capillary fluid flow in concrete using a DEM-CFD approach
    • Marek Krzaczek
    • Michał Nitka
    • Andrzej Tejchman-Konarzewski
    2022

    Sformułowano połączone podejście do modelowania dwufazowego przepływu wody napędzanego hydraulicznie i kapilarnie w nienasyconym betonie. Proces przepływu analizowano numerycznie w mezoskali w warunkach dwuwymiarowych (2D), łącząc metodę elementów dyskretnych (DEM) z obliczeniową dynamiką płynów (CFD) w warunkach izotermicznych. Przeprowadzono w pełni sprzężone hydromechaniczne testy symulacyjne na małych próbkach betonu o uproszczonej mezostrukturze cząstek stałych. Obliczenia DEM/CFD wykonano kolejno dla próbek czystej osnowy cementowej, osnowy cementowej z kruszywem oraz osnowy cementowej z kruszywem i strefą przejściową międzyfazową (ITZ) o określonej grubości.

  • Modeling of Electrodynamic Phenomena in an Ultra-Rapid Inductive–Dynamic Actuator as Applied to Hybrid Short-Circuit Breakers - A Review Study
    • Damian Hallmann
    • Piotr Jankowski
    • Janusz Mindykowski
    • Kazimierz Jakubiuk
    • Mikołaj Nowak
    • Mirosław Wołoszyn
    2022 Pełny tekst ENERGIES

    This article is a study of the research development of electrodynamic phenomena occurring in ultra-fast electrodynamic drives. These types of linear drives are among the fastest, not only because of the huge accelerations achieved, but, above all, because of the extremely short reaction time. For this reason, electrodynamic drives are used in hybrid short-circuit breakers. The phenomena occurring in this type of drive are actually magneto-thermo-elastic in nature, but the coupling of these phenomena should be considered weak if the criteria for repeatable operation in a hybrid circuit breaker system are met. The authors have been researching this type of drive for many years through not only experimental studies, but also primarily simulation studies developing models of such drives. The authors present the history of the development starting from the first works of Thomson, and Kesserling and ending with the most current models, including mainly their own. This article presents mainly works studying electrodynamic phenomena. Thermal and mechanical phenomena were comprehensively presented by the authors in previous papers.

  • Modeling the Structure, Dynamics, and Transformations of Proteins with the UNRES Force Field
    • Adam K. Sieradzan
    • Cezary Czaplewski
    • Paweł Krupa
    • Magdalena Mozolewska
    • Agnieszka S. Karczyńska
    • Agnieszka G. Lipska
    • Emilia Lubecka
    • Ewa Gołaś
    • Tomasz Wirecki
    • Mariusz Makowski
    • Stanisław Ołdziej
    • Adam Liwo
    2022

    The physics-based united-residue (UNRES) model of proteins ( www.unres.pl ) has been designed to carry out large-scale simulations of protein folding. The force field has been derived and parameterized based on the principles of statistical-mechanics, which makes it independent of structural databases and applicable to treat nonstandard situations such as, proteins that contain D-amino-acid residues. Powered by Langevin dynamics and its replica-exchange extensions, UNRES has found a variety of applications, including ab initio and database-assisted protein-structure prediction, simulating protein-folding pathways, exploring protein free-energy landscapes, and solving biological problems. This chapter provides a summary of UNRES and a guide for potential users regarding the application of the UNRES package in a variety of research tasks.

  • Modelling and Analysis of the Positioning Accuracy in the Loading Systems of Mobile Cranes
    • Wojciech Kacalak
    • Zbigniew Budniak
    • Maciej Majewski
    2022 Pełny tekst Materials

    In this work, the authors analyse the influence of the order and range of sequential movements of a crane's working members on the accuracy of the final cargo positioning. The analysis was conducted on the basis of a specially developed method in which the authors proposed the introduction of a geometrical indicator of positioning the load in the intermediate positions (after completing each movement sequence) and in the target position, depending on the adopted control strategy and the accuracy of kinematic input of the working mechanisms (powered mechanisms). A mathematical model was presented to enable the accuracy of unidirectional positioning of the crane's working members when conducting sequential movements controlled through the rotation of the crane column, inner and outer boom, and retractable stages of the six-section telescopic boom. Sample results of the numerical simulations showing the influence of the assumed kinematic inputs of the crane members on the accuracy of unidirectional angular and linear positioning and, consequently, on the accuracy of the final positioning of the transported cargo, were presented. Moreover, an indicator of the cargo positioning accuracy dependent on the location of an operator or a video camera and the trajectory of the cargo was developed, allowing the formulation of application conclusions.

  • Modelling of Longitudinal Elastic Wave Propagation in a Steel Rod Using the Discrete Element Method
    • Magdalena Knak
    • Michał Nitka
    • Erwin Wojtczak
    • Magdalena Rucka
    2022 Pełny tekst Materials

    The paper deals with the issue of modelling elastic wave propagation using the discrete element method (DEM). The case of a longitudinal wave in a rod with a circular cross-section was considered. A novel, complex algorithm consisting of the preparation of models and simulation of elastic waves was developed. A series of DEM models were prepared for simulations, differing in discretisation and material parameters. Additional calculations with the finite element method (FEM) were performed. Numerical wave signals were obtained from each simulation and compared with experimental results to choose the best DEM model based on the correlation between the waveforms. Moreover, dispersion curves were prepared for each model to verify the agreement with the Pochhammer-Chree wave propagation theory. Both experimental and theoretical approaches indicated the same model as the most suitable. The analysis results allowed stating that DEM can be successfully used for modelling wave propagation in structural rods.

  • Modelling the impact of the agricultural holdings and land-use structure on the quality of inland and coastal waters with an innovative and interdisciplinary toolkit
    • Lidia Anita Dzierzbicka-Glowacka
    • Dawid Dybowski
    • Maciej Janecki
    • Ewa Wojciechowska
    • Beata Szymczycha
    • Dawid Potrykus
    • Artur Nowicki
    • Adam Szymkiewicz
    • Piotr Zima
    • Beata Jaworska-Szulc
    • Stefan Pietrzak
    • Grażyna Pazikowska-sapota
    • Dominika Kalinowska
    • Nicole Nawrot
    • Paweł Wielgat
    • Grażyna Dembska
    • Karolina Matej-Łukowicz
    • Katarzyna Szczepańska
    • Tadeusz Puszkarczuk
    2022 Pełny tekst AGRICULTURAL WATER MANAGEMENT

    The changes taking place in the marine coastal zones are extremely important, as about 40% of the human population currently lives in the coastal areas (within 100 kilometres of the coastline) increasing anthropogenic pressure on the marine ecosystems. Agriculture is a significant source of nutrients to the marine environment that increase hypoxia, eutrophication and may pose a threat to the services provided by ecosystems. In particular, surface water and submarine groundwater discharge (SGD) are dominant pathways of nutrient loads. The main aim of this study is to present the capabilities and results of an innovative and complex toolkit that enables researchers to identify the sources of nutrient and pesticide pollution, calculate their flux via rivers and SGD, and directly assess the influence of pesticides and nutrient flux on the coastal ecosystem. We combined the in situ sampling of surface water, groundwater, soil, SGD, and seawater with a model study to create a set of tools for assessing the influence of agriculture on the marine environment. The maximum concentrations of nitrates and phosphates were measured in the drainage ditches and were equal to 15.5 mg N-NO L−1 and 7.7 mg P-PO L−1 respectively. The nutrients concentrations varied from 0.1 to 12.9 mg N-NO L−1 and from 0.0 to 0.5 mg P-PO L−1 in all freshwater samples. In contrast, the lowest concentrations were observed in seawater with maximum levels of 0.8 mg N-NO L−1 and 0.1 mg P-PO L−1 respectively. The collected data were used to establish an innovative and interdisciplinary online toolkit in which surface run-off was modelled with Soil and Water Assessment Tool (SWAT), groundwater flow with Modflow, and marine waters using the EcoPuckBay model. Additionally, the tool includes two interactive calculators for calculation of the nutrient balance and nitrogen leaching for single fields on farms.

  • Modelowanie 3D zabytkowego obiektu sakralnego za pomocą stacjonarnego skaningu laserowego na podstawie analizy światła naturalnego
    • Paweł Tysiąc
    • Anna Sieńska
    • Marta Tarnowska
    • Piotr Kędziorski
    • Marcin Jagoda
    2022 Pełny tekst Materiały Budowlane

    Technologia skanowania laserowego jest powszechnie stosowana w inwentaryzacji obiektów kultury. Ciągły wzrost technologiczny pozwala na wykorzystanie złożonych modeli cyfrowych 3D przez coraz większą liczbę odbiorców. Jedną z odmian zastosowania modeli jest tzw. HBIM (HistoricalBIM/ HeritageBIM). W artykule skupiliśmy się na pierwszym z etapów zarządzania takim projektem, jak inwentaryzacja. Celem pracy jest określenie przydatności stosowania modelowania 3D na potrzeby analizy obiektów kultury oraz analiza dokładności modelu. Na podstawie wykonanego modelu przeprowadzono analizę oświetlenia kościoła. Przedstawiona metoda może być interpretowana pod kątem technicznym oraz humanistycznym (w przypadku analizy sacrum).

  • Modelowanie emisji z wykorzystaniem symulacji mikroskopowych
    • Jacek Oskarbski
    • Konrad Biszko
    2022 Pełny tekst Transport Miejski i Regionalny

    W artykule poruszono zagadnienia związane z modelowaniem emisji spalin z wykorzystaniem mikroskopowych symulacji ruchu drogowego. Celem pracy było opracowanie modelu ruchu, na podstawie którego możliwe jest obliczenie emisji z pojazdów z uwzględnieniem typu skrzyżowania oraz wartości natężeń ruchu. W artykule skupiono się na wartościach zużycia paliwa i emisji dwutlenku węgla. Przeanalizowano literaturę w zakresie czynników wpływających na emisję, które zależne są od człowieka, pojazdu i infrastruktury. Dokonano przeglądu matematycznych modeli pozwalających na obliczenie wartości chwilowych, często związanych ze zużyciem paliwa, które stanowią podstawę do oszacowania emisji. Wybrany model został zaimplementowany do modułu oprogramowania mikrosymulacyjnego w celu analizy wielkości emisji, w zależności od natężenia ruchu na skrzyżowaniu o ruchu okrężnym i skrzyżowaniu z pierwszeństwem przejazdu. Przedstawiono wyniki badań z uwzględnieniem wariantów modeli sieci obejmujących jedynie dojazd i przejazd przez skrzyżowanie oraz niezależnie uwzględniających rozpędzanie pojazdów za skrzyżowaniem. W końcowym fragmencie artykułu objęto dyskusją wybrane założenia, możliwe do uwzględnienia w analizach i mające wpływ na osiągnięte wyniki, omówiono kwestie dokładności modelu oraz zaproponowano rozwiązania pozwalające na zwiększenie poziomu szczegółowości osiąganych wyników.

  • Modelowanie wymiany ciepła przy wrzeniu w przepływie w warunkach podwyższonego ciśnienia zredukowanego dla R1233zd(E) jako potencjalnego czynnika w układach ORC [w:] Postępy w badaniach wymiany ciepła i masy
    • Michał Pysz
    • Dariusz Mikielewicz
    2022 Pełny tekst

    Proces wrzenia w wysokotemperaturowych pompach ciepła oraz układach ORC zachodzi przy temperaturach wyższych niż 80˚C. W literaturze występuje luka w wiedzy dla podwyższonych temperatur nasycenia oraz korespondujących wysokich ciśnień zredukowanych. Większość istniejących danych doświadczalnych dotyczy temperatur niższych niż 40 ˚C, co związane jest z zastosowaniami chłodniczymi czynników niskowrzących. Dla temperatur wyższych niż 120 ˚C większość czynników pracuje w okolicach termodynamicznego punktu krytycznego, gdzie występują gwałtowne zmiany lepkości oraz gęstości faz ciekłej oraz parowej, co ma znaczący wpływ na oddziaływania międzyfazowe. Większość modeli literaturowych opiera się na konkretnych parametrach eksperymentalnych i nie ma charakteru ogólnego dla zastosowań dla płynów i warunków termodynamicznych nie będących przedmiotem eksperymentu. Przedstawiony w pracy model ma solidne podstawy fizyczne i dużą ogólność, będąc niezależnym od rodzaju czynnika. Celem przetestowania modelu w warunkach podwyższonych ciśnień zredukowanych zbudowano dedykowane stanowisko eksperymentalne. W powyższym badaniu przeprowadzono systematyczne badania eksperymentalne dla wrzenia w przepływie czynnika R1233zd(E). Dane uzyskano dla cylindrycznego pionowego minikanału o średnicy wewnętrznej 2 mm oraz długości 300 mm. Zakres ciśnień zredukowanych przedstawionych w badaniu zawiera się w zakresie od 0,2 do 0,7, prędkość masowa od 400 do 1000 kg/m2s, a gęstość strumienia ciepła od 20 do 45 kW/m2. Przedstawiono wpływ struktury przepływu na uzyskane trendy wymiany ciepła. Dane eksperymentalne zostały również porównane z najbardziej znanymi modelami literaturowymi.

  • Modification of TiO2 nanotubes by graphene–strontium and cobalt molybdate perovskite for efficient hydrogen evolution reaction in acidic medium
    • Mariusz Szkoda
    • Anna Ilnicka
    • Malgorzata Skorupska
    • Marcin Wysokowski
    • Jerzy P. Lukaszewicz
    2022 Pełny tekst Scientific Reports

    Herein, we demonstrate that modification of TiO2 nanotubes with graphene–strontium and cobalt molybdate perovskite can turn them into active electrocatalysts for hydrogen evolution reaction (HER). For this purpose, a simple method of hydrothermal synthesis of perovskites was developed directly on the TiO2 nanotubes substrate. Moreover, the obtained hybrids were also decorated with graphene oxide (GO) during one-step hydrothermal synthesis. The obtained materials were characterized by scanning electron microscopy with energy dispersive X-ray analysis, Raman spectroscopy, and X-ray diffraction analysis. Catalytic properties were verified by electrochemical methods (linear voltammetry, chronopotentiometry). The obtained hybrids were characterized by much better catalytic properties towards hydrogen evolution reaction compared to TiO2 and slightly worse than platinum. The optimized hybrid catalyst (decorated by GO) can drive a cathodic current density of 10 mA cm−2 at an overpotential of 121 mV for HER with a small Tafel slope of 90 mV dec−1 in 0.2 M H2SO4.

  • Modified Preisach model of hysteresis in multi air gap ferrite core medium frequency transformer
    • Michał Michna
    • Piotr Dworakowski
    • Andrzej Wilk
    • Filip Kutt
    • Michel Mermet-Guyennet
    2022 Pełny tekst IEEE TRANSACTIONS ON POWER DELIVERY

    This article presents the modified Preisach model of hysteresis for a 3-phase medium frequency transformer in a 100 kW dual active bridge converter. The transformer magnetic core is assembled out of ferrite I-cores, which results in multiple parasitic air gaps. For this transformer, the hysteresis loops were measured and parameters of the Preisach model were determined. The Preisach distribution function is approximated with a two-dimensional Gauss function series and the feedback function is a 3rd-degree polynomial. The optimized identification of Preisach distribution function parameters was prepared. Two sets of parameters were determined based on the analysis of major and minor hysteresis loop. The developed model is used to analyze the transformer core power loss. A new set of Steinmetz equation parameters for multi air gap ferrite core MFT is proposed.

  • Modulation of dielectric properties in low-loss polypropylene-based composites at GHz frequencies: theory and experiment
    • Konrad Wilczyński
    • Anna Wróblewska
    • Agata Dzieniszewska
    • Jerzy Krupka
    • Michał Mrozowski
    • Mariusz Zdrojek
    2022 Pełny tekst Scientific Reports

    Polymer composites with high dielectric constant and low loss tangent are highly regarded as substrates for modern high-speed electronics. In this work, we analyze the high-frequency dielectric properties of two types of composites based on polypropylene infused with high-dielectric-constant microparticles. Two types of fillers are used: commercial ceramics or titanium oxide ( TiO2) with different concentrations. The key observation is that adding the fillers causes an increase of dielectric constants by around 100% (for highest loading) up to 4.2 and 3.4, for micro-ceramics and TiO2 based composites, respectively. Interestingly, for the TiO2 composite, the loss tangent depends on the filler loading volume, whereas the other composite has a slightly increasing tendency, however, being at the level ~ 10– 3. To explain the experimental results, a theoretical model determined by microwave reflection and transmission through a representative volume element is proposed, which allows the investigation of the impact of volume ratio, grain shape, aggregation, and size on the loss tangent and permittivity evolution. This approach could be used for modeling other low dielectric loss materials with inclusions.

  • Molecular Imaging and Nanotechnology—Emerging Tools in Diagnostics and Therapy
    • Marcin Woźniak
    • Agata Płoska
    • Anna Siekierzycka
    • Lawrence W. Dobrucki
    • Leszek Kalinowski
    • Iwona T. Dobrucki
    2022 Pełny tekst INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    Personalized medicine is emerging as a new goal in the diagnosis and treatment of diseases. This approach aims to establish differences between patients suffering from the same disease, which allows to choose the most effective treatment. Molecular imaging (MI) enables advanced insight into molecule interactions and disease pathology, improving the process of diagnosis and therapy and, for that reason, plays a crucial role in personalized medicine. Nanoparticles are widely used in MI techniques due to their size, high surface area to volume ratio, and multifunctional properties. After conjugation to specific ligands and drugs, nanoparticles can transport therapeutic compounds directly to their area of action and therefore may be used in theranostics—the simultaneous implementation of treatment and diagnostics. This review summarizes different MI techniques, including optical imaging, ultrasound imaging, magnetic resonance imaging, nuclear imaging, and computed tomography imaging with theranostics nanoparticles. Furthermore, it explores the potential use of constructs that enables multimodal imaging and track diseases in real time.

  • Monitoring działania wzmocnienia gruntu pod nasypem drogowym za pomocą sztywnych kolumn
    • Adam Jabłonowski
    • Piotr Kanty
    • Adam Krasiński
    2022 Pełny tekst Inżynieria Morska i Geotechnika

    Opis systemu pomiarowego zainstalowanego w kolumnach betonowych wzmacniających słabe podłoże gruntowe pod nasypem drogowym. Wstępne przedstawienie przykładowych wyników pomiarów. Problematyka niedokładności i odchyleń pomiarowych oraz sposób ich interpretacji.

  • Monitoring Lead Concentration in the Surrounding Environmental Components of a Lead Battery Company: Plants, Air and Effluents—Case Study, Kenya
    • Jeremiah Otieno
    • Przemysław Kowal
    • Jacek Mąkinia
    2022 Pełny tekst International Journal of Environmental Research and Public Health

    Lead (Pb) pollution from smelters and lead–acid battery has become a serious problem worldwide owing to its toxic nature as a heavy metal. Stricter regulations and monitoring strategies have been formulated, legislated and implemented in various parts of the world on heavy metal usage. Developed countries such as the USA and in Europe largely operate within the set standards, however, developing countries such as Kenya, Nigeria and India, with limited regulatory capacity, resources and sufficient data, face poor Pb waste management and exposure of the population to health risks. This study assessed the pollution concerns from Associated Battery Manufacturers (East Africa) Limited (ABM), located in the Nairobi Industrial Area in Kenya. Samples of air, extracts from plants (leaves) and factory wastewaters were taken from different operations units, prepared and analysed with Atomic Absorption Spectrometry (AAS). Pb traces remained fairly controlled with averages of 1.24 ± 0.42 parts per million (ppm), 1.21 ± 0.02 ppm and 0.29 ± 0.01 ppm in the air, plant extracts and effluents, respectively. The conducted research shows that the obtained lead concentrations in the air, wastewater and surrounding plants exceeded the recommended standards, and are potentially harmful not only to workers, but also to the surrounding villages

  • Monitoring the fracture process of concrete during splitting using integrated ultrasonic coda wave interferometry, digital image correlation and X-ray micro-computed tomography
    • Erwin Wojtczak
    • Magdalena Rucka
    • Łukasz Skarżyński
    2022 Pełny tekst NDT & E INTERNATIONAL

    The paper deals with the continuous-time monitoring of mechanical degradation in concrete cubes under splitting. A series of experiments performed with integrated coda wave interferometry (CWI) and digital image correlation (DIC), supported with X-ray micro-computed tomography (micro-CT) is reported. DIC and micro-CT techniques were used to characterize the fracture process in detail. CWI method was proved to be effective in the assessment of damage level based on the changes in decorrelation between coda wave signals. The possibility of early detection of damage using CWI is promising for possible applications in the diagnostics of concrete elements.

  • Monitoring the gas turbine start-up phase on the platform using a hierarchical model based on Multi-Layer Perceptron networks
    • Tacjana Niksa-Rynkiewicz
    • Anna Witkowska
    • Jerzy Głuch
    • Marcin Adamowicz
    2022 Pełny tekst Polish Maritime Research

    Very often, the operation of diagnostic systems is related to the evaluation of process functionality, where the diagnostics is carried out using reference models prepared on the basis of the process description in the nominal state. The main goal of the work is to develop a hierarchical gas turbine reference model for the estimation of start-up parameters based on multi-layer perceptron neural networks. A functional decomposition of the gas turbine start-up process was proposed, enabling a modular analysis of selected parameters of the process. Real data sets obtained from observations of the turbo-generator set located on a North Sea platform were used.

  • Monolithic vs. Microservice Architecture: A Performance and Scalability Evaluation
    • Grzegorz Blinowski
    • Anna Ojdowska
    • Adam Przybyłek
    2022 Pełny tekst IEEE Access

    Context. Since its proclamation in 2012, microservices-based architecture has gained widespread popularity due to its advantages, such as improved availability, fault tolerance, and horizontal scalability, as well as greater software development agility. Motivation. Yet, refactoring a monolith to microservices by smaller businesses and expecting that the migration will bring benefits similar to those reported by top global companies, such as Netflix, Amazon, eBay, and Uber, might be an illusion. Indeed, for systems that do not have thousands of concurrent users and can be scaled vertically, the benefits of such migration have not been sufficiently investigated, while the existing evidence is inconsistent. Objective. The purpose of this paper is to compare the performance and scalability of monolithic and microservice architectures on a reference web application. Method. The application was implemented in four different versions, covering not only two different architectural styles (monolith vs. microservices) but also two different implementation technologies (Java vs. C#.NET). Next, we conducted a series of controlled experiments in three different deployment environments (local, Azure Spring Cloud, and Azure App Service). Findings. The key lessons learned are as follows: (1) on a single machine, a monolith performs better than its microservice-based counterpart; (2) The Java platform makes better use of powerful machines in case of computation-intensive services when compared to.NET; the technology platform effect is reversed when non-computationally intensive services are run on machines with low computational capacity; (3) vertical scaling is more cost-effective than horizontal scaling in the Azure cloud; (4) scaling out beyond a certain number of instances degrades the application performance; (5) implementation technology (either Java or C#.NET) does not have a noticeable impact on the scalability performance.

  • Monomeric Triphosphinoboranes: Intramolecular Lewis Acid–Base Interactions between Boron and Phosphorus Atoms
    • Anna Ordyszewska
    • Natalia Szynkiewicz
    • Jarosław Chojnacki
    • Rafał Grubba
    2022 Pełny tekst INORGANIC CHEMISTRY

    Herein, we present the synthesis of the first fully characterized monomeric triphosphinoboranes. The simple reaction of boron tribromide with three equivalents of bulky lithium phosphide tBu2PLi yielded triphosphinoborane (tBu2P)3B. Triphosphinoboranes with diversified phosphanyl substituents were obtained via a two-step reaction, in which isolable bromodiphosphinoborane (tBu2P)2BBr is first formed and then reacts with one equivalent of less bulky phosphide R2PLi (R2P = Cy2P, iPr2P, tBuPhP, Ph2P). By utilizing this method, we obtained a series of triphosphinoboranes with the general formula (tBu2P)2BPR2. Based on structural and theoretical studies, two main types of triphosphinoborane structures can be distinguished. In the first type, all three electron lone pairs interact with the formally empty p-orbital of the central boron atom, resulting in delocalized π-bonding, whereas in the second type, one localized double P=B bond and two single P-B bonds are observed. The Lewis acidic-basic properties of triphosphinoboranes during the reaction of (tBu2P)2BPiPr2 with H3B·SMe2 were analyzed. The abovementioned P-B bond-containing compound not only formed an adduct with BH3 but also activated the B-H bond of the borane molecule, resulting in the incorporation of the BH2 unit into two phosphorus atoms and migration of a hydride to the boron atom of the parent triphosphinoborane. The structures of the triphosphinoboranes were confirmed by single crystal X-ray analysis, multinuclear NMR spectroscopy, and elemental analysis.

  • More Than just Antioxidants: Redox-Active Components and Mechanisms Shaping Redox Signalling Network
    • Monika Baranowska
    • Patrycja Jakubek
    • Agnieszka Bartoszek-Pączkowska
    2022 Pełny tekst Antioxidants

    settingsOrder Article Reprints This is an early access version, the complete PDF, HTML, and XML versions will be available soon. Open AccessReview More Than just Antioxidants: Redox-Active Components and Mechanisms Shaping Redox Signalling Network by Monika Kuczyńska,Patrycja Jakubek andAgnieszka Bartoszek *ORCID Faculty of Chemistry, Gdańsk University of Technology, 80-233 Gdańsk, Poland * Author to whom correspondence should be addressed. Antioxidants 2022, 11(12), 2403; https://doi.org/10.3390/antiox11122403 (registering DOI) Received: 26 September 2022 / Revised: 28 November 2022 / Accepted: 30 November 2022 / Published: 4 December 2022 (This article belongs to the Special Issue 10th Anniversary of Antioxidants—Review Collection) Download Versions Notes Abstract The concept of oxidative stress as a condition underlying a multitude of human diseases has led to immense interest in the search for antioxidant-based remedies. The simple and intuitive story of “the bad” reactive oxygen species (ROS) and “the good” antioxidants quickly (and unsurprisingly) lead to the commercial success of products tagged “beneficial to health” based solely on the presence of antioxidants. The commercial success of antioxidants by far preceded the research aimed at understanding the exact redox-related mechanisms that are in control of shaping the states of health and disease. This review describes the redox network formed by the interplay of ROS with cellular molecules and the resulting regulation of processes at the genomic and proteomic levels. Key players of this network are presented, both involved in redox signalling and control of cellular metabolism linked to most, if not all, physiological processes. In particular, this review focuses on the concept of reductive stress, which still remains less well-established compared to oxidative stress.

  • Morphology changes in Fe-Cr porous alloys upon high-temperature oxidation quantified by X-ray tomographic microscopy
    • Damian Koszelow
    • Sebastian Molin
    • Jakub Karczewski
    • F. Marone
    • Małgorzata Makowska
    2022 Pełny tekst MATERIALS & DESIGN

    The effect of high-temperature oxidation at 850 C (10 h, 30 h, 100 h) and 900 C (10 h) on porous (30 % porosity) ferritic stainless steel (Fe22Cr) has been investigated using synchrotron tomographic microscopy, which allowed for visualisation, separation and quantitative analysis of the metallic core, closed pores, open pores and oxide scale phase. The same regions within the samples were investigated before and after oxidation performed at different conditions. Quantitative analysis of the tomographic data provided information on changes upon oxidation of the relative volume of the different phases, the specific surface area (SSA) of the metallic core, the thickness of the oxide scale and pore size distribution. The results were discussed in the context of thermogravimetric analysis of the samples and supported by SEM imaging. It was observed that oxidation leads to an increase of the SSA of steel and the largest increase (50 %) was obtained for the sample processed for 100 h at 850 C. It is demonstrated the open porosity forms a network of connected channels within the sample and it dominates in the volume. In addition, the 3D imaging revealed breakaway oxidation areas for samples, for which this phenomenon remained undetected using 2D SEM analysis.

  • MORPHOLOGY OF BUILDING DEVELOPMENT AS AN ELEMENT OF URBAN VENTIALTION SYSTEM
    • Katarzyna Zielonko-Jung
    • Mariya-Veronika Mochulska
    2022 Pełny tekst Architecture Civil Engineering Environment

    Problems related to air quality in large urban agglomerations (e.g., high concentration of pollutants, the urban heat island phenomenon) make it necessary to take comprehensive measures to improve air exchange in urban areas.The article concerns the relationship between wind phenomena observable in cities and the geometrical features of building development. The knowledge on the subject is already well-founded and has been intensively developed. Regardless, it remains relatively poorly applied to urban planning. Based on the analysis of source literature, the classification of features and spatial elements of building development that are crucial for ventilation is conducted in the following paper. Five different cities are also analyzed regardinghow the air exchange improvement policy should be pursued through conscious building development shaping. The cities selected for analysis include Warsaw and Cracow in Poland, a large agglomeration of New Dehli in India,the experimental Masdar Cityin the United Arab Emirates, and the newly designed Jätkäsaaridistrict of Helsinki. Based on the example of the above cities, the article investigates the possibilities of combining spatial features of building development that are essential to aerodynamics, in order to create effective ventilation systems.

  • Most Uniwersytecki w Bydgoszczy. Teoretyczne podstawy decyzji o wyłączeniu obiektu z ruchu
    • Krzysztof Żółtowski
    • Mikołaj Binczyk
    • Przemysław Kalitowski
    2022 Pełny tekst Inżynieria i Budownictwo

    W artykule przedstawiono ogólny opis konstrukcji podwieszonego mostu Uniwersyteckiego nad rzeką Brdą w Bydgoszczy. Opisano również prace eksperckie dotyczące oceny nośności konstrukcji. W wyniku badań i analiz obiekt został uznany za niebezpieczny dla użytkowników i wycofany z eksploatacji. W artykule przedstawiono zasadnicze przesłanki, które doprowadziły zarządcę do podjęcia głównych decyzji i postępowania naprawczego.

  • MPPT and GMPPT Implementation for Buck-Boost Mode Control of quasi-Z-Source Inverter
    • Oleksandr Husev
    • Dmitri Vinnikov
    • Carlos Roncero-Clemente
    • Frede Blaabjerg
    • Ryszard Strzelecki
    2022 Pełny tekst IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS

    The focus is on the maximum power point tracking implementation for the buck-boost voltage mode control of a single-phase multilevel inverter based on a three-level neutral point clamped quasi-Z-source topology. To utilize shoot-through states only when boost function is needed and avoid it in the buck mode, two different control approaches are required. This work proposes merged control system which provides switching between different control algorithms in the buck and boost modes. In particular, a hysteresis band between the buck and boost modes is proposed which provides smooth and stable performance. It also includes features of the implementation of the global maximum power point tracking, which can scan the entire input voltage range in up to 10 seconds. Experimental results showed that proposed control system provides high and stable MPPT efficiency in different operation points. Finally, the key features are verified, the advantages, drawbacks, and an eventual potential for other applications are presented in conclusions.

  • Multiaxial Fatigue Behaviour of SLM 18Ni300 Steel
    • Ricardo Branco
    • José Domingos Costa
    • J. A. M. Ferreira
    • C. Capela
    • Filippo Berto
    • Wojciech Macek
    2022 Structural Integrity

    Fatigue behaviour of SLM 18Ni300 steel under proportional bending-torsion loading is studied. The fatigue tests are conducted under pulsating loading conditions using tubular specimens with a transversal circular hole. Three ratios of the normal stress to shear stress are considered, namely σ/τ=4,σ/τ=2 and σ/τ = 4/3. Crack initiation sites were found for two diametrically opposite points around the hole, whose locations are governed by the loading scenario. Crack angles at the early stage of growth were successfully predicted from the first principal direction at the nodes with maximum values of the first principal stress at the hole. Fatigue crack initiation life was estimated based on the SWT parameter, defined from uniaxial low-cycle fatigue tests performed for smooth standard specimens under fully reversed strain-controlled conditions. Overall, predicted lives are in agreement with the experiments.

  • Multi-Beam Antenna for Ka-Band CubeSat Connectivity Using 3-D Printed Lens and Antenna Array
    • Kamil Trzebiatowski
    • Weronika Kalista
    • Mateusz Rzymowski
    • Łukasz Kulas
    • Krzysztof Nyka
    2022 Pełny tekst IEEE Antennas and Wireless Propagation Letters

    In this paper, the design of a passive multi-beam lens antenna is proposed for the CubeSat space communication system as an alternative application of a 2-D microstrip antenna array that has originally been designed for a 39 GHz 5 G MU-MIMO system. The half-ellipsoid lens is 3-D printed using stereolithography (SLA) technology. The antenna prototype is capable of selecting the main beam between 16 different directions with a gain ranging from 14 to 16 dBi and a half-power beamwidth of 14∘ to 18∘. The measurements carried out in an anechoic chamber show good agreement with numerical simulations. The presented prototype shows that by employing 3-D printing technologies existing antennas can be easily and inexpensively converted to switched-beam or multi-beam solutions.

  • Multi-Criterial Design of Antennas with Tolerance Analysis Using Response-Feature Predictors
    • Anna Pietrenko-Dąbrowska
    • Paulina Kozieł
    • Leifur Leifsson
    2022

    Imperfect manufacturing is one of the factors affecting the performance of antenna systems. It is particularly important when design specifications are strict and leave a minimum leeway for a degradation caused by geometry or material parameter deviations from their nominal values. At the same time, conventional antenna design procedures routinely neglect to take the fabrication tolerances into account, which is mainly a result of a challenging nature of uncertainty quantification. Nevertheless, the ability to assess the effects of parameter deviations and to mitigate thereof is instrumental in achieving truly robust antenna designs. Furthermore, identifying the antenna-specific relationships be-tween nominal requirements and tolerance immunity is essential to determine the necessary levels of fabrication accuracy, which affects both the reliability and the manufacturing costs. This paper proposes a technique for multi-criterial optimization of antenna structures oriented towards rendering a family of designs rep-resenting trade-offs between the nominal performance and the robustness. The fundamental components of our procedure are feature-based regression models constructed at the level of selected characteristic points of the antenna outputs. The trade-off designs are generated sequentially, using local search carried out for gradually relaxed nominal requirements. Numerical experiments conducted for two microstrip antennas demonstrate that the proposed algorithm is capable of yielding the performance/robustness Pareto set at the cost of only a few dozens of EM analysis of the antenna at hand per design, while ensuring reliability, as validated by means of EM-based Monte Carlo simulation.

  • Multidirectional Characterization of Phytochemical Profile and Health-Promoting Effects of Ziziphora bungeana Juz. Extracts
    • Karlygash Zhaparkulova
    • Aigerim Karaubayeva
    • Zuriyadda Sakipova
    • Anna Biernasiuk
    • Katarzyna Gaweł-Bęben
    • Tomasz Laskowski
    • Aliya Kusniyeva
    • Azamat Omargali
    • Tolkyn Bekezhanova
    • Liliya Ibragimova
    • Galiya Ibadullayeva
    • Amangeldy Jakiyanov
    • Karolina Czech
    • Kuanysh Tastambek
    • Kazimierz Głowniak
    • Anna Malm
    • Wirginia Kukula-Koch
    2022 Pełny tekst MOLECULES

    Ziziphora species (Lamiaceae) have been used in traditional medicine as sedatives, anti-septics, carminatives, or expectorants. Despite their common applications in phytotherapy, there is still lack of evidence about the composition of their extracts and its impact on biological properties of the plants. The aim of this study was to evaluate the content of Ziziphora bungeana, a less studied species growing in Kazakhstan, using HPLC-ESI-QTOF-MS/MS instrumentation and to determine its antimicrobial, antioxidant, and cytotoxic activity together with inhibitory properties against tyrosinase and toxicity in erythrocyte lysis assay. Extracts from Z. bungeana were found to be sources of flavonoids, phenolic acids, organic acids, and terpenes that determined their antiradical activity. The minimum inhibitory concentrations of extracts were lower for Gram-positive bacteria (1.25–10 mg/mL) than for Gram-negative bacteria and fungi (5–20 mg/mL). The EC50 value calculated for antiradical activity ranged between 15.00 ± 1.06 µg/mL and 13.21 ± 3.24 µg/mL for ABTS and DPPH assays, respectively. Z. bungeana extracts were found to decrease the activity of tyrosinase by 50% (at 200 µg/mL) similarly to kojic acid and were slightly cytotoxic for human melanoma A375 cell line (at 200 µg/mL) with no effect on HaCaT keratinocytes. In the end, Z. bungeana did not reveal toxic effects in hemolytic assay as compared to the positive control Triton X-100. The performed tests show potential application of the plant in the treatment of infectious diseases, disorders caused by free radicals, and skin problems.

  • Multi-domain and Context-Aware Recommendations Using Contextual Ontological User Profile
    • Aleksandra Karpus
    • Krzysztof Goczyła
    2022

    Recommender Systems (RS) became popular tools in many Web services like Netflix, Amazon, or YouTube, because they help a~user to avoid an information overload problem. One of the types of RS are Context-Aware RS (CARS) which exploit contextual information to provide more adequate recommendations. Cross-Domain RS (CDRS) were created as a response to the data sparsity problem which occurs when only few users can provide reviews or ratings for many items. One of the kinds of CDRS are Multi-domain RS which use user information from at least two domains to recommend items from all these domains. In this paper, we investigate how Contextual Ontological User Profile can be used for making multi-domain and context-aware recommendations. We show the improvement of accuracy and diversity of recommendations while combining CARS with CDRS.

  • Multi-functional sensor based on photonic crystal fiber using plasmonic material and magnetic fluid
    • Muhammad Bilal
    • Servando Lopez-Aguayo
    • Małgorzata Szczerska
    • Hamza Madni
    2022 Pełny tekst OSA Continuum

    A unique highly sensitive photonic crystal fiber is investigated based on plasmonic material and magnetic fluid (MF) for the simultaneous measurement of temperature and magnetic field sensor. The designed sensor is explored by tracing the different parameters such as birefringence, coupling length, power spectrum, and the peak wavelength of the transmission intensity. The magnetic field and temperature computation are attained simultaneously by examining the linear fitting curve and the movement of transmission peaks. The obtained sensitivity for temperature is 7.1nm/°C with an exposure range of 25°C to 100°C. In contrast, the magnetic field sensitivity is 12nm/Oe with a detection range of 160-200 Oe. In addition, the resolutions are -1.245°C, 5.53 Oe for temperature and magnetic field, respectively. Our inspected sensor is used to detect extremely low and high values of magnetic fields. The investigated structure is presented with simplification, compactness, easy implementation, and high sensitivity, which is expected to be a good foundation for the advancement of optical sensing devices in the future applications of industries, security, small grids, and environmental systems.

  • Multi-layered mineral glass units used as viewport elements of underwater ship structures
    • Krzysztof Lipiński
    • Krzysztof Bobrowski
    • Edmund Wittbrodt
    • Bogusław Szarejko
    • Eugeniusz Ziółkowski
    2022

    In the paper, Authors deals with viewport elements of underwater marine constructions. If a single-plate viewport constructions are considered, big thicknesses of the glass plate are required to resist the pressure. To build the viewports from the commercially accessible glass panes, multi-layered glass units are proposed in the paper. Numerical calculations are presented, summarized and compared with experimental tests. Focusing on their main idea, proposed viewports are inspired by the classical glass-lamination, but instead of gluing them with polyvinyl butyral, the glass panes are separated with deionized water that fills up all the hermetic inter-chambers formed by the panes. Heat-tempered mineral-glass panes are considered. Significant areas of the viewports are required. Performed numerical tests are addressed to verify statics, strength and stability of the proposed multi-layered innovative construction. Finite elements are used to create the models and to calculate the stress fields of all the glass elements of the viewports. Strengths of the investigated multi-layered units are estimated according to probabilistic theory of failure. Different constructional variants are tested for the viewports, including these made of flat and of curved glass panes. The final parameters of the optimal solution are not presented in the paper. The paper-presented examples certify however, that significant reduction of stresses is possible, especially of these occurring in the glass panes and, what follows, it certify that construction of underwater viewports of considerable dimensions is possible for viewports based on the standard thicknesses of the commercially accessible glass panes.

  • Multipath Complex Root Tracing
    • Sebastian Dziedziewicz
    • Małgorzata Warecka
    • Rafał Lech
    • Piotr Kowalczyk
    2022

    The problem of multipath root tracing is being addressed in this communication. The self-adaptive complex root tracing algorithm, which was previously utilized for the investigation of various propagation and radiation problems, is analyzed here for the cases when the traced characteristic bifurcates. A procedure of multiroute detection is proposed and demonstrated on the coaxially loaded cylindrical waveguide example.

  • Multi-pathway mechanism of polydopamine film formation at vertically aligned diamondised boron-doped carbon nanowalls
    • Adrian Olejnik
    • Mateusz Ficek
    • Katarzyna Siuzdak
    • Robert Bogdanowicz
    2022 ELECTROCHIMICA ACTA

    Boron-doped carbon nanowall (B:CNW) electrodes were used as a platform for studying the electropolymerisation of dopamine. Due to the unique properties of B:CNW, including the fast charge-transfer kinetics and high surface conductivity, a high degree of reversibility of redox reactions was achieved. Three separated redox peaks were observed on voltammograms and attributed to three fundamental reactions in the dopamine polymerisation mechanism: dopamine/dopamine quinone, leukodopaminechrome/dopaminechrome, and dihydroxyindole/indolequinone. The mechanism was also supported by the density functional theory calculations of the single point energy of the polydopamine structural units. Moreover, the electrochemical impedance spectroscopy experiments strongly suggest that the majority of th epolymerisation occurs only in the narrow range of potentials between +0.0 and +0.4 V vs. the silver chloride reference electrode. The concept of a resistor-like CPE element is introduced to facilitate the description of the electrochemical properties of B:CNW electrodes in a neutral electrolyte. Further, it is shown that electropolymerisation differs significantly as a function of pH. In acidic environments (pH 3–6) mostly the dopamine/dopamine quinone reaction can be seen, whereas in a more alkaline pH (8–10), the leukodopaminechrome/dopaminechrome reaction becomes dominant. The dihydroxyindole/indolequinone redox pair is seen only in a short pH interval between 7 and 8. Additionally, the kinetics of polymerisation is significantly boosted when the pH is more than 7. Together, these results provide insight into the complexity of the formation of polydopamine and can assist in better controlling the properties of electropolymerised dopamine films.