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Gdańsk University of Technology

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  • Rapid Variable-Resolution Parameter Tuning of Antenna Structures Using Frequency-Based Regularization and Sparse Sensitivity Updates
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    2022 IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION

    Geometry parameter tuning is an inherent part of antenna design process. While most often performed in a local sense, it still entails considerable computational expenses when carried out at the level of full-wave electromagnetic (EM) simulation models. Moreover, the optimization outcome may be impaired if good initial design is not available. This paper proposes a novel approach to fast and improved-reliability gradient-based optimization of antenna structures. Our approach employs a frequency-based regularization to facilitate relocation of antenna operating parameters to their target values, which increases the chances of identifying a satisfactory design under challenging conditions (e.g., poor-quality starting point). At the same time, computational efficiency of the tuning process is enhanced through the involvement of variable-resolution EM models, and restricting the finite-differentiation sensitivity updates to selected parameters only. The latter are decided upon based on the analysis of the design relocation between the subsequent iterations of the optimization algorithm. The presented technique is validated using three examples of microstrip antennas optimized under different scenarios (matching improvement, gain enhancement, size reduction). The results demonstrate superior performance in terms of reliability and design quality as compared to conventional gradient-based and derivative-free search procedures. At the same time, a significant speedup is achieved over the frequency-regularization-based procedure not using the acceleration mechanisms.

  • Rapid Yield Optimization of Miniaturized Microwave Passives by Response Features and Variable-Fidelity EM Simulations
    • Anna Pietrenko-Dąbrowska
    • Sławomir Kozieł
    2022 Full text Scientific Reports

    The operation of high-frequency devices, including microwave passive components, can be impaired by fabrication tolerances but also incomplete knowledge concerning operating conditions (temperature, input power levels) and material parameters (e.g., substrate permittivity). Although the accuracy of manufacturing processes is always limited, the effects of parameter deviations can be accounted for in advance at the design phase through optimization of suitably selected statistical performance figures. Perhaps the most popular one is the yield, which provides a straightforward assessment of the likelihood of fulfilling performance conditions imposed upon the system given the assumed deviations of designable parameters. The latter are typically quantified by means of probability distributions pertinent to the fabrication process. The fundamental obstacle of the yield-driven design is its high computational cost. The primary mitigation approach nowadays is the employment of surrogate modeling methods. Yet, a construction of reliable metamodels becomes problematic for systems featuring a large number of degrees of freedom. Our work proposes a technique for fast yield optimization of microwave passives, which relies on response feature technology as well as variable-fidelity simulation models. Utilization of response features enables efficient handling of issues related to the system response nonlinearities. Meanwhile, the incorporation of variable-resolution simulations allows for accelerating the yield estimation process, which translates into remarkably low overall cost of the optimizing the yield. Our approach is verified with the use of three microstrip couplers. Comprehensive benchmarking demonstrates its superiority in terms of computational efficiency over the state-of-the-art algorithms, whereas reliability is corroborated by electromagnetic (EM)-driven Monte Carlo simulations.

  • "Raport z wstępnych badań własności stali trudnościeralnej 460HB",. ang "Report on preliminary tests of the properties of wear-resistant steel 460HB"
    • Wojciech Kiełczyński
    • Maria Głowacka
    • Lech Nadolny
    • Izydor Jóźwowski
    2022

    Mikrostrukturę badanej stali trudnościeralnej 460HB stanowi drobnoziarnisty martenzyt odpuszczony, który jest właściwy dla stali konstrukcyjnych niskowęglowych, niskostopowych ulepszonych cieplnie. W przypadku blach grubych, do których zalicza się badana stal, struktura może ulec zaburzeniu, jeżeli w hutniczym procesie wytwórczym wystąpiła niejednorodność odkształcenia plastycznego i w konsekwencji tworzenie się pasm segregacyjnych, jak w przypadku badanej stali. W badanej stali we występujących w strukturze obszarach jasnych pasm, zmierzona mikrotwardość HV0,05 jest znacząco większa w porównaniu do twardości w pasmach ciemnych- średnie wartości: 640 HV0,05 do 485 HV0,05..Powodem jest większy udział twardych węglików, powstałych podczas odpuszczania w pasmach jasnych. Pasmowy rozkład węglików wzdłuż kierunku walcowania jest przyczyną wydatnego obniżenia odporności stali na pękanie oraz niekorzystne zwiększenie anizotropii własności plastycznych blach, wyrażonej przez stosunek energii łamania próbek Charpy V poprzecznych do wzdłużnych, co ma istotne znaczenie podczas procesu spawania. Poziom udarności uzyskany wyniku łamania próbek w badaniach udarności jest nie do zaakceptowania.

  • Realizacja definiowanego programowo interfejsu radiowego NB-IoT
    • Olga Błaszkiewicz
    • Jarosław Magiera
    • Alicja Olejniczak
    • Piotr Rajchowski
    • Jarosław Sadowski
    • Jacek Stefański
    • Krzysztof Cwalina
    2022

    W niniejszym artykule przedstawiono sposób realizacji definiowanego programo-wo, uniwersalnego interfejsu radiowego do inteligentnych urządzeń IoT (Internet of Things) - DUCH IoT, pracującego zgodnie z międzynarodowymi standardami: LTE (Long Term Evolution) kat. NB1 (Narrowband) oraz LTE kat. NB2. Interfejs radiowy został za-implementowany w formie sprzętowo-programowego, frameworka z konfigurowalnym podziałem realizowanych funkcji pomiędzy częścią sprzętową (zrealizowaną jako moduły IP Core opisane w języku HDL (Hardware Description Language) w sposób niezależny od technologii) a częścią programową frameworka NB1/NB2 (zrealizowaną jako programowe moduły opracowane w języku C/C++), w zależności od możliwości obliczeniowych i za-sobów sprzętowych urządzenia IoT. Przedstawiono architekturę całego interfejsu wraz z modułową strukturą zaprojektowaną do przetwarzania stosu LTE NB-IoT.

  • Real-time monitoring of the emission of volatile organic compounds from polylactide 3D printing filaments
    • Wojciech Wojnowski
    • Kaja Kalinowska
    • Tomasz Majchrzak
    • Bożena Zabiegała
    2022 Full text SCIENCE OF THE TOTAL ENVIRONMENT

    Establishing the emission profile of volatile organic compounds generated during fused deposition modeling 3D printing using polymer filaments is important in terms of both understanding the processes taking place during thermal degradation of thermoplastics, and assessing the user's exposure to potentially harmful volatiles. However, obtaining detailed, real-time qualitative and quantitative results poses a challenge. In this paper solid-phase microextraction-gas chromatography-time-of-flight mass spectrometry and proton transfer reaction time-of-flight mass spectrometry were used to identify and monitor the emission of volatiles during thermal degradation of polylactide filaments and during 3D printing. Filaments of two different grades and three colours were used. It was possible to obtain detailed, time- and temperature-resolved emission profiles of the main products of thermal decomposition of lactide and polylactide 3D printing filaments at concentration levels of a few μg/g. This revealed different temperature-dependent emission characteristics of particular volatiles, such as, among others, lactide, acetaldehyde, acetic acid, and 2-butanone between various polylactide 3D printing filaments. This approach can be used to monitor the emission associated with printing with various other types of polymer 3D printing materials.

  • Real‐Time PPG Signal Conditioning with Long Short‐Term Memory (LSTM) Network for Wearable Devices
    • Marek Wójcikowski
    2022 Full text SENSORS

    This paper presents an algorithm for real‐time detection of the heart rate measured on a person’s wrist using a wearable device with a photoplethysmographic (PPG) sensor and accelerometer. The proposed algorithm consists of an appropriately trained LSTM network and the Time‐Domain Heart Rate (TDHR) algorithm for peak detection in the PPG waveform. The Long Short‐Term Memory (LSTM) network uses the signals from the accelerometer to improve the shape of the PPG input signal in a time domain that is distorted by body movements. Multiple variants of the LSTM network have been evaluated, including taking their complexity and computational cost into consideration. Adding the LSTM network caused additional computational effort, but the performance results of the whole algorithm are much better, outperforming the other algorithms from the literature.

  • Rearrangements of the nitrifiers population in an activated sludge system under decreasing solids retention times
    • Przemysław Kowal
    • Mohamad-Javad Mehrani
    • Dominika Sobotka
    • Sławomir Ciesielski
    • Jacek Mąkinia
    2022 Full text ENVIRONMENTAL RESEARCH

    Due to the key role of nitrite in novel nitrogen removal systems, nitrite oxidizing bacteria (NOB) have been receiving increasing attention. In this study, the coexistence and interactions of nitrifying bacteria were explored at decreasing solids retention times (SRTs). Four 5-week washout experiments were carried out in laboratory-scale (V=10 L) sequencing batch reactors (SBRs) with mixed liquor from two full-scale activated sludge systems (continuous flow vs SBR). During the experiments, the SRT was gradually reduced from the initial value of 4.0 d to approximately 1.0 d. The reactors were operated under limited dissolved oxygen conditions (set point of 0.6 mg O2/L) and two process temperatures: 12℃ (winter) and 20℃ (summer). At both temperatures, the progressive SRT reduction was inefficient for the out-selection of both canonical NOB and comammox Nitrospira. However, the dominant NOB switched from Nitrospira to Ca. Nitrotoga, whereas the dominant AOB was always Nitrosomonas. The results of this study are important for optimizing NOB suppression strategies in the novel N removal processes, which are based on nitrite accumulation.

  • Recent Advancements in Cyclodextrin-Based Adsorbents for the Removal of Hazardous Pollutants from Waters
    • Shan E Zehra Syeda
    • Dominika Nowacka
    • Muhammad Shahzeb Khan
    • Muhammad Khan
    • Anna Skwierawska
    2022 Full text Polymers

    Water is an essential substance for the survival on Earth of all living organisms. However, population growth has disturbed the natural phenomenon of living, due to industrial growth to meet ever expanding demands, and, hence, an exponential increase in environmental pollution has been reported in the last few decades. Moreover, water pollution has drawn major attention for its adverse effects on human health and the ecosystem. Various techniques have been used to treat wastewater, including biofiltration, activated sludge, membrane filtration, active oxidation process and adsorption. Among the mentioned, the last method is becoming very popular. Moreover, among the sorbents, those based on cyclodextrin have gained worldwide attention due to their excellent properties. This review article overviewed recent contributions related to the synthesis of Cyclodextrin (CD)-based adsorbents to treat wastewater, and their applications, especially for the removal of heavy metals, dyes, and organic pollutants (pharmaceuticals and endocrine disruptor chemicals). Furthermore, new adsorption trends and trials related to CD-based materials are also discussed regarding their regenerative potential. Finally, this review could be an inspiration for new research and could also anticipate future directions and challenges associated with CD-based adsorbents.

  • Recent advancements in LC‐MS based analysis of biotoxins: Present and future challenges
    • Debabrata Panda
    • Bisnu P. Dash
    • Sivakumar Manickam
    • Grzegorz Boczkaj
    2022 MASS SPECTROMETRY REVIEWS

    There has been a rising concern regarding the harmful impact of biotoxins, source of origin, and the determination of the specific type of toxin. With numerous reports on their extensive spread, biotoxins pose a critical challenge to figure out their parent groups, metabolites, and concentration. In that aspect, liquid chromatography‐mass spectrometry (LC‐MS) based analysis paves the way for its accurate identification and quantification. The biotoxins are ideally categorized as phytotoxins, mycotoxins, shellfish‐toxins, ciguatoxins, cyanotoxins, and bacterial toxins such as tetrodotoxins. Considering the diverse nature of biotoxins, both low‐resolution mass spectrometry (LRMS) and high‐resolution mass spectrometry (HRMS) methods have been implemented for their detection. The sample preparation strategy for complex matrix usually includes “QuEChERS” extraction or solid‐phase extraction coupled with homogenization and centrifugation. For targeted analysis of biotoxins, the LRMS consisting of a tandem mass spectrometer operating in multiple reaction monitoring mode has been widely implemented. With the help of the reference standard, most of the toxins were accurately quantified. At the same time, the suspect screening and nontarget screening approach are facilitated by the HRMS platforms during the absence of reference standards. Significant progress has also been made in sampling device employment, utilizing novel sample preparation strategies, synthesizing toxin standards, employing hybrid MS platforms, and the associated data interpretation. This critical review attempts to elucidate the progress in LC‐MS based analysis in the determination of biotoxins while pointing out major challenges and suggestions for future development.

  • Recent advances in aqueous virus removal technologies
    • Hussein Al-Hazmi
    • Hanieh Shokrani
    • Amirhossein Shokrani
    • Karam Jabbour
    • Otman Abida
    • Seyed Soroush Mousavi Khadem
    • Sajjad Habibzadeh
    • Shirish H. Sonawane
    • Mohammad Saeb
    • Adrián Bonilla-Petriciolet
    • Michael Badawi
    2022 CHEMOSPHERE

    The COVID-19 outbreak has triggered a massive research, but still urgent detection and treatment of this virus seems a public concern. The spread of viruses in aqueous environments underlined efficient virus treatment processes as a hot challenge. This review critically and comprehensively enables identifying and classifying advanced biochemical, membrane-based and disinfection processes for effective treatment of virus-contaminated water and wastewater. Understanding the functions of individual and combined/multi-stage processes in terms of manufacturing and economical parameters makes this contribution a different story from available review papers. Moreover, this review discusses challenges of combining biochemical, membrane and disinfection processes for synergistic treatment of viruses in order to reduce the dissemination of waterborne diseases. Certainly, the combination technologies are proactive in minimizing and restraining the outbreaks of the virus. It emphasizes the importance of health authorities to confront the outbreaks of unknown viruses in the future.

  • Recent Advances in Development of Waste-Based Polymer Materials: A Review
    • Krzysztof Formela
    • Maria Kurańska
    • Mateusz Barczewski
    2022 Full text Polymers

    Limited petroleum sources, suitable law regulations, and higher awareness within society has caused sustainable development of manufacturing and recycling of polymer blends and composites to be gaining increasing attention. This work aims to report recent advances in the manufacturing of environmentally friendly and low-cost polymer materials based on post-production and postconsumer wastes. Sustainable development of three groups of materials: wood polymer composites, polyurethane foams, and rubber recycling products were comprehensively described. Special attention was focused on examples of industrially applicable technologies developed in Poland over the last five years. Moreover, current trends and limitations in the future “green” development of waste-based polymer materials were also discussed.

  • Recent advances in hydrodynamic cavitation-based pretreatments of lignocellulosic biomass for valorization
    • Xun Sun
    • Shuai Liu
    • Xinyan Zhang
    • Yang Tao
    • Grzegorz Boczkaj
    • Joon Yong Yoon
    • Xiaoxu Xuan
    2022 BIORESOURCE TECHNOLOGY

    Recently, the hydrodynamic cavitation (HC)-based pretreatment has shown high effectiveness in laboratories and even in industrial productions for conversion of lignocellulosic biomass (LCB) into value-added products. The pretreatment capability derives from the extraordinary conditions of pressures at ∼500 bar, local hotspots with ∼5000 K, and oxidation (hydroxyl radicals) created by HC at room conditions. To promote this emerging technology, the present review summarizes the recent advances in the HC-based pretreatment of LCB. The principle of HC including the sonochemical effect and hydrodynamic cavitation reactor is introduced. The effectiveness of HC on the delignification of LCB as well as subsequent fermentation, paper production, and other applications is evaluated. Several key operational factors (i.e., reaction environment, duration, and feedstock characteristics) in HC pretreatments are discussed. The enhancement mechanism of HC including physical and chemical effects is analyzed. Finally, the perspectives on future research on the HC-based pretreatment technology are highlighted.

  • Recent advances on SOA formation in indoor air, fate and strategies for SOA characterization in indoor air - A review
    • Klaudia Pytel
    • Renata Marcinkowska
    • Małgorzata Rutkowska
    • Bożena Zabiegała
    2022 Full text SCIENCE OF THE TOTAL ENVIRONMENT

    Recent studies proves that indoor air chemistry differs in many aspects from atmospheric one. People send up to 90 % of their life indoors being exposed to pollutants present in gas, particle and solid phase. Particle phase indoor is composed of particles emitted from various sources, among which there is an indoor source – secondary chemical reactions leading to formation of secondary organic aerosol (SOA). Lately, researchers' attentions turned towards the ultrafine particles, for there are still a lot of gaps in knowledge concerning this field of study, while there is evidence of negative influence of ultrafine particles on human health. Presented review sums up current knowledge about secondary particle formation in indoor environment and development of analytical techniques applied to study those processes. The biggest concern today is studying ROS, for their lifetime in indoor air is very short due to reactions at the very beginning of terpene oxidation process. Another interesting aspect that is recently discovered is monoterpene autooxidation process that leads to HOMs formation that in turn can influence SOA formation yield. A complex studies covering gas phase and particle phase characterization, but also toxicological studies are crucial to fully understand indoor air chemistry leading to ultrafine particle formation.

  • Recent and Emerging Applications of Graphene-based metamaterials in Electromagnetics
    • Meisam Esfandiari
    • Ali Lalbakhsh
    • Paria Shehni
    • Saughar Jarchi
    • Mohsen Miab
    • Hamideh Mahtaj
    • Sam Reisenfeld
    • Mohammad Alibakhshikenari
    • Sławomir Kozieł
    • Stanisław Szczepański
    2022 Full text MATERIALS & DESIGN

    Surface Plasmon Polaritons (SPPs) operating in mid-infrared up to terahertz (THz) frequencies have been traditionally manufactured on expensive metals such as gold, silver, etc. However, such metals have poor surface confinement that limits the optical applications of SPPs. The invention of graphene is a breakthrough in plasmon-based devices in terms of design, fabrication and applications, thanks to its plasmonic wave distribution, low-cost prototyping and its inherent reconfigurability. In addition, recent advancements in plasmon-based metamaterials and metasurfaces led to the elimination of the past constraints on regular optical devices, opening a new door in THz devices and applications. This paper provides an operational perspective of the advanced graphene-based electromagnetic devices, with a focus on graphene enabled antennas, absorbers and sensors, analyzing the strengths and limitations of various design methodologies.

  • Recent Progress on Hydrogen Storage and Production Using Chemical Hydrogen Carriers
    • Ewelina Pawelczyk
    • Natalia Łukasik
    • Izabela Wysocka
    • Andrzej Rogala
    • Jacek Gębicki
    2022 Full text ENERGIES

    Depleting fossil fuel resources and anthropogenic climate changes are the reasons for the intensive development of new, sustainable technologies based on renewable energy sources. One of the most promising strategies is the utilization of hydrogen as an energy vector. However, the limiting issue for large-scale commercialization of hydrogen technologies is a safe, efficient, and economical method of gas storage. In industrial practice, hydrogen compression and liquefaction are currently applied; however, due to the required high pressure (30–70 MPa) and low temperature (−253 °C), both these methods are intensively energy consuming. Chemical hydrogen storage is a promising alternative as it offers safe storage of hydrogen-rich compounds under ambient conditions. Although many compounds serving as hydrogen carriers are considered, some of them do not have realistic perspectives for large-scale commercialization. In this review, the three most technologically advanced hydrogen carriers—dimethyl ether, methanol, and dibenzyltoluene—are discussed and compared. Their potential for industrial application in relation to the energy storage, transport, and mobility sectors is analyzed, taking into account technological and environmental aspects.

  • Recognition of Emotions in Speech Using Convolutional Neural Networks on Different Datasets
    • Marta Zielonka
    • Artur Piastowski
    • Andrzej Czyżewski
    • Paweł Nadachowski
    • Maksymilian Operlejn
    • Kamil Kaczor
    2022 Full text Electronics

    Artificial Neural Network (ANN) models, specifically Convolutional Neural Networks (CNN), were applied to extract emotions based on spectrograms and mel-spectrograms. This study uses spectrograms and mel-spectrograms to investigate which feature extraction method better represents emotions and how big the differences in efficiency are in this context. The conducted studies demonstrated that mel-spectrograms are a better-suited data type for training CNN-based speech emotion recognition (SER). The research experiments employed five popular datasets: Crowdsourced Emotional Multimodal Actors Dataset (CREMA-D), Ryerson Audio-Visual Database of Emotional Speech and Song (RAVDESS), Surrey Audio-Visual Expressed Emotion (SAVEE), Toronto Emotional Speech Set (TESS), and The Interactive Emotional Dyadic Motion Capture (IEMOCAP). Six different classes of emotions were used: happiness, anger, sadness, fear, disgust, and neutral. However, some experiments were prepared to recognize just four emotions due to the characteristics of the IEMOCAP dataset. A comparison of classification efficiency on different datasets and an attempt to develop a universal model trained using all datasets were also performed. This approach brought an accuracy of 55.89% when recognizing four emotions. The most accurate model for six emotion recognition was trained and achieved 57.42% accuracy on a combination of four datasets (CREMA-D, RAVDESS, SAVEE, TESS). What is more, another study was developed that demonstrated that improper data division for training and test sets significantly influences the test accuracy of CNNs. Therefore, the problem of inappropriate data division between the training and test sets, which affected the results of studies known from the literature, was addressed extensively. The performed experiments employed the popular ResNet18 architecture to demonstrate the reliability of the research results and to show that these problems are not unique to the custom CNN architecture proposed in experiments. Subsequently, the label correctness of the CREMA-D dataset was studied through the employment of a prepared questionnaire.

  • Recurrent Neural Network Based Adaptive Variable-Order Fractional PID Controller for Small Modular Reactor Thermal Power Control
    • Bartosz Puchalski
    • Tomasz Rutkowski
    • Jarosław Tarnawski
    • Tomasz Karla
    2022

    This paper presents the synthesis of an adaptive PID type controller in which the variable-order fractional operators are used. Due to the implementation difficulties of fractional order operators, both with a fixed and variable order, on digital control platforms caused by the requirement of infinite memory resources, the fractional operators that are part of the discussed controller were approximated by recurrent neural networks based on Gated Recurrent Unit cells. The study compares the performance of the proposed neural controller with other solutions, which are based on definitional fractional-order operators exploiting an infinite memory buffer and a classical adaptive PID controller. The proposed neural approximations of variable-order fractional operators applied to a PID-type controller provide a viable solution that can be successfully implemented on present-day digital control platforms. The research presented here focuses on the aspects of accuracy of approximators in simulated operating conditions within the thermal power control system of the challenging plant such as Small Modular Nuclear Reactor.

  • Redesigning Informal Beirut: Shaping the Sustainable Transformation Strategies
    • Piotr Lorens
    • Dorota Wojtowicz-Jankowska
    • Bahaa Bou Kalfouni
    2022 Full text Urban Planning

    Lebanon is distinguished by its strategic geographical location among the Arab countries. Beirut, as the capital city and the major commercial and cultural centre of the country, is a point of interest for migrants. The region has witnessed many changes since the end of World War II, which have resulted in internal and external conflicts, migrations, the centralization of the country’s economy, etc. Furthermore, the city has witnessed many periods of urbanization, destruction, reconstruction, and regeneration, which has contributed to the complex nature of the city’s population and a blurring of the boundaries between settlements which are quite different in their natures. As a result, Beirut has become a home to mixed communities and societies of different origins and natures. The extensive inflow of migrants combined with economic crises has contributed to the appearance of informal settlements. They are located in different areas of the city and its surroundings, known as Greater Beirut. These settlements face various challenges, including spatial organization, socioeconomic standing, and environmental concerns. The current situation in Lebanon (resulting from the Covid‐19 pandemic combined with the 4th of August 2020 blast in the port of Beirut) makes these challenges even more appalling. Some of the key issues discussed in this article are associated with the origin, current state, and prospects for improving the urban quality of these informal settlements considering their unplanned development and underused potentials. The article includes an inventory and speculates about the best possible strategies derived from three local interventions which are based on published reports. These examples represent rehabilitation and reconstruction activities in different cities in Lebanon. They can be applied to the specific situation of Beirut, given the variety of possible contexts there. The authors’ initial intention is to deal with the possible scope of the physical improvement in these settlements which will lead to socioeconomic and environmental development and will also include possible ways of reinventing Beirut’s urban structure

  • Reduced-cost optimization-based miniaturization of microwave passives by multi-resolution EM simulations for internet of things and space-limited applications
    • Anna Pietrenko-Dąbrowska
    • Sławomir Kozieł
    • Ali Raef
    2022 Full text Electronics

    Stringent performance specifications along with constraints imposed on physical dimensions, make the design of contemporary microwave components a truly onerous task. In recent years, the latter demand has been growing in importance, with the innovative application areas such as Internet of Things coming into play. The need to employ full-wave electromagnetic (EM) simu-lations for response evaluation, reliable yet CPU heavy, only aggravates the issue. This paper proposes a reduced-cost miniaturization algorithm that employs trust-region search procedure and multi-resolution EM simulations. In our approach, the resolution of the EM model is ad-justed throughout the optimization process based on its convergence status starting from the lowest admissible fidelity. As the algorithm converges, the resolution is increased up to the high-fidelity one, used at the final phase to ensure reliability. Four microwave components have been utilized as verification structures: an impedance matching transformer, and three branch-line couplers. Significant savings in terms of the number of EM analyses required to con-clude the size reduction process of 41, 42, 38 and 50 percent have been obtained (in comparison to a single-fidelity procedure). The footprint area of the designs optimized using the pro-posed approach are equal to: 32, 205, 410 and 132 mm2, in comparison to 52, 275, 525, and 213 mm2 of the initial (and already compact) design.

  • Reduced-Cost Two-Level Surrogate Antenna Modeling using Domain Confinement and Response Features
    • Anna Pietrenko-Dąbrowska
    • Sławomir Kozieł
    • Ullah Ubaid
    2022 Full text Scientific Reports

    Electromagnetic (EM) simulation tools have become indispensable in the design of contemporary antennas. Still, the major setback of EM-driven design is the associated computational overhead. This is because a single full-wave simulation may take from dozens of seconds up to several hours, thus, the cost of solving design tasks that involve multiple EM analyses may turn unmanageable. This is where faster system representations (surrogates) come into play. Replacing expensive EM-based evaluations by cheap yet accurate metamodels seems to be an attractive solution. Still, in antenna design, application of surrogate models is hindered by the curse of dimensionality. A practical workaround has been offered by the recently reported reference-design-free constrained modeling techniques that restrict the metamodel domain to the parameter space region encompassing high-quality designs. Therein, the domain is established using only a handful of EM-simulations. This paper proposes a novel modeling technique, which incorporates the response feature technology into the constrained modeling framework. Our methodology allows for rendering accurate surrogates using exceptionally small training data sets, at the expense of reducing the generality of the modeling procedure to antennas that exhibit consistent shape of input characteristics. The proposed technique can be employed in other fields that employ costly simulation models (e.g., mechanical or aerospace engineering).

  • Regeneration Project of Market Places GOSPOSTRATEG – “Polanki” Market in Gdańsk-Oliwa Pilot Project Monitoring Dataset
    • Justyna Borucka
    2022 Full text

    The dataset entitled Monitoring of activities carried out as part of prototyping and implementation of the pilot project in the area of the “Polanki” market and its direct neighbourhood, in the Gdańsk-Oliwa district, step1; stage from July 2020 year contains tabular monitoring lists (quantitative and qualitative documentation report in the form of tables) of activities carried out as part of the prototyping and implementation of the pilot project in the area of the Polanki market and its immediate vicinity in the Gdańsk-Oliwa district conducted during the month of July 2020. The data collection was carried out as part of the first step of monitoring in the series: “Monitoring of activities, prototyping and implementation of the pilot project in the area of the “Polanki” market, Gdańsk-Oliwa district, step1”. The second step of monitoring is scheduled for 2021. Monitoring is the basis for the subsequent analysis used in the implementation of the pilot project of the “Polanki” Market and supports the proper development of the regeneration project of the marketplace.

  • Regenerative Drug Discovery Using Ear Pinna Punch Wound Model in Mice
    • Paweł Sosnowski
    • Piotr Sass
    • Paulina Słonimska
    • Rafał Płatek
    • Jolanta Kamińska
    • Jakub Baczyński-Keller
    • Piotr Mucha
    • Grażyna Peszyńska-Sularz
    • Artur Czupryn
    • Michał Pikuła
    • Arkadiusz Piotrowski
    • Łukasz Janus
    • Sylwia Rodziewicz-Motowidło
    • Piotr Skowron
    • Paweł Sachadyn
    2022 Full text Pharmaceuticals

    The ear pinna is a complex tissue consisting of the dermis, cartilage, muscles, vessels, and nerves. Ear pinna healing is a model of regeneration in mammals. In some mammals, including rabbits, punch wounds in the ear pinna close spontaneously; in common-use laboratory mice, they remain for life. Agents inducing ear pinna healing are potential regenerative drugs. We tested the effects of selected bioactive agents on 2 mm ear pinna wound closure in BALB/c mice. Our previous research demonstrated that a DNA methyltransferase inhibitor, zebularine, remarkably induced ear pinna regeneration. Although experiments with two other demethylating agents, RG108 and hydralazine, were unsuccessful, a histone deacetylase inhibitor, valproic acid, was another epigenetic agent found to increase ear hole closure. In addition, we identified a pro-regenerative activity of 4-ketoretinoic acid, a retinoic acid metabolite. Attempts to counteract the regenerative effects of the demethylating agent zebularine, with folates as methyl donors, failed. Surprisingly, a high dose of methionine, another methyl donor, promoted ear hole closure. Moreover, we showed that the regenerated areas of ear pinna were supplied with nerve fibre networks and blood vessels. The ear punch model proved helpful in testing the pro-regenerative activities of small-molecule compounds and observations of peripheral nerve regeneration.

  • Regulation of LPS assembly via controlled proteolysis and sensing of LPS stress in Escherichia coli
    • Daria Biernacka
    2022 Full text

    Lipopolysaccharide (LPS) is a complex glycolipid, essential for the bacterial viability and along with phospholipids, it constitutes the major amphiphilic component of outer membrane (OM) in most of the Gram-negative bacteria, including Escherichia coli. LPS molecules confer an effective permeability barrier to the OM and play a crucial role in bacteria-environment and -host interactions. The synthesis and accumulation of this highly heterogeneous in the composition molecule are controlled by abundance of regulatory factors and growth conditions. Furthermore, the synthesis of LPS and phospholipids is tightly co-regulated and held at a nearly constant ratio. Any alterations in the balance of phospholipids and LPS are not tolerated by bacteria and cause cell death. This balance is achieved by tightly regulated turnover of unstable LpxC enzyme to maintain the flux of common precursor for the utilization in either LPS or phospholipid biosynthetic pathways. It constitutes an essential branch point in the biosynthesis of phospholipids and the lipid A part of LPS and simultaneously determines the first committed step in LPS biosynthetic pathway. It has been reported that LPS assembly requires the essential LapB protein to regulate FtsH-mediated proteolysis of LpxC protein. To further understand the function of LapB and its role in LpxC turnover, multicopy suppressor screening of ΔlapB was employed and it revealed a role for HslUV proteases in regulating LpxC amounts, providing the first alternative pathway of LpxC degradation. Isolation and characterization of an extragenic suppressor mutation that prevents lethality of ΔlapB by restoration of normal LPS synthesis identified a frame-shift in the essential gene designated lapC, suggesting LapB and LapC act antagonistically. The same lapC gene was identified during selection for mutations that induce transcription from LPS defects-responsive rpoEP3 promoter, confer sensitivity to LpxC inhibitor CHIR090 and exhibit a temperature-sensitive phenotype. Suppressors of lapC mutants that restored growth at elevated temperatures mapped to lapA/lapB, lpxC and ftsH genes. Such suppressor mutations restored normal levels of LPS and prevented excessive proteolysis of LpxC in lapC mutants. Interestingly, a lapC deletion could be constructed in strains either overproducing LpxC or in the absence of LapB, revealing that FtsH, LapB and LapC together regulate LPS synthesis by controlling LpxC amounts.

  • REJESTRACJA SERII ZDJĘĆ, Z WYMUSZENIEM ZMIENNYCH WARUNKÓW OŚWIETLENIOWYCH, JAKO TECHNIKI WSPOMAGAJĄCEJ PRZY AUTOMATYCZNYM ROZPOZNAWANIU TEKSTU
    • Grzegorz Jędrzejewski
    • Stanisław Galla
    2022 Elektronika : konstrukcje, technologie, zastosowania

    W artykule przedstawiono autorskie rozwiązania problemu wykonywania zdjęć niewyraźnych tekstów na opakowaniach i niewielkich produktach. W sytuacji gdy napis posiada niską rozdzielczość (drukarka atramentowa), albo jest wykonany poprzez technikę tłoczenia, wykonanie zwykłego, pojedynczego zdjęcia daje przeważnie niezadowalające wyniki. Dzięki przedstawionym tu rozwiązaniom, znacząco polepszamy materiał wejściowy (fotografie), który jest podstawą, na przykład do analizy przez algorytmy uczenia maszynowego, dedykowanych do rozpoznawania znaków (OCR).

  • Relations between magnetosonic perturbations as an indicator of a magnetosonic exciter and equilibrium parameters of a plasma
    • Anna Perelomova
    2022 Full text CONTRIBUTIONS TO PLASMA PHYSICS

    The thermodynamic relations between perturbation of pressure and pertur- bation of mass density and between components of velocity which specify a magnetosonic wave are theoretically studied. A planar flow with the wave vec- tor forming a constant angle with the equilibrium magnetic field is investigated. The theory considers deviation from the adiabaticity of a flow due to some kind of heating–cooling function and thermal conduction of a plasma. It considers also the weak impact of nonlinearity. The thermodynamic relations and corre- sponding diagrams reveal the hysteretic character of irreversible processes in a plasma flow and may indicate damping and nonlinear parameters of a flow. They may indicate also the geometry of a flow, the equilibrium parameters of plasma, and specify a magnetosonic source. The harmonic and impulsive exciters are discussed in this connection.

  • Relationship between Telomere Length, TERT Genetic Variability and TERT, TP53, SP1, MYC Gene Co-Expression in the Clinicopathological Profile of Breast Cancer
    • Marta Dratwa
    • Barbara Wysoczanska
    • Wioletta Brankiewicz
    • Martyna Stachowicz-Suhs
    • Joanna Wietrzyk
    • Rafał Matkowski
    • Marcin Ekiert
    • Jolanta Szelachowska
    • Adam Maciejczyk
    • Mariusz Szajewski
    • Maciej Bagiński
    • Katarzyna Bogunia-Kubik
    2022 Full text INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    The molecular mechanisms of telomerase reverse transcriptase (TERT) upregulation in breast cancer (BC) are complex. We compared genetic variability within TERT and telomere length with the clinical data of patients with BC. Additionally, we assessed the expression of the TERT, MYC, TP53 and SP1 genes in BC patients and in BC organoids (3D cell cultures obtained from breast cancer tissues). We observed the same correlation in the blood of BC patients and in BC organoids between the expression of TERT and TP53. Only in BC patients was a correlation found between the expression of the TERT and MYC genes and between TP53 and MYC. We found associations between TERT genotypes (rs2735940 and rs10069690) and TP53 expression and telomere length. BC patients with the TT genotype rs2735940 have a shorter telomere length, but patients with A allele rs10069690 have a longer telomere length. BC patients with a short allele VNTR-MNS16A showed higher expression of the SP1 and had a longer telomere. Our results bring new insight into the regulation of TERT, MYC, TP53 and SP1 gene expression related to TERT genetic variability and telomere length. Our study also showed for the first time a similar relationship in the expression of the above genes in BC patients and in BC organoids. These findings suggest that TERT genetic variability, expression and telomere length might be useful biomarkers for BC, but their prognostic value may vary depending on the clinical parameters of BC patients and tumor aggressiveness.

  • Relative quantification of pork and beef in meat products using global and species-specific peptide markers for the authentication of meat composition
    • Katarzyna Nalazek-Rudnicka
    • Ilona Kłosowska-Chomiczewska
    • Jens Brockmeyer
    • Andrzej Wasik
    • Adam Macierzanka
    2022 Full text FOOD CHEMISTRY

    We used global and species-specific peptide markers for a relative quantitative determination of pork and beef in raw and processed meat products made of the two meat species. Four groups of products were prepared (i.e., minced raw meats, sausages, raw and fried burgers) in order to represent products with different extents of food processing. In each group, the products varied in the pork/beef proportions. All products were analysed by multiple reaction monitoring mass spectrometry (MRM–MS) for the presence/concentration of pork- and beefspecific peptide markers, as well as global markers – peptides widely distributed in muscle tissue. The combined MRM-MS analysis of pork-specific peptide HPGDFGADAQGAMSK, beef-specific peptide VLGFHG and global marker LFDLR offered the most reliable validation of declared pork/beef compositions across the whole range of meat products. Our work suggests that a simultaneous analysis of global and species-specific peptide markers can be used for composition authentication in commercial pork/beef products.

  • Reliability of acicular grindable thermocouples for transient temperature measurements at sliding contacts
    • Oleksii Nosko
    • Yurii Tsybrii
    • Wojciech Tarasiuk
    • Andrey Nosko
    2022 Full text MEASUREMENT

    Acicular grindable thermocouples represent an interesting and prospective technique of temperature measurements at sliding contacts. This study aimed at the investigation of their reliability and accuracy as applied to the friction materials of various classes in contact with steel. The tests were conducted on a pin-on-disc tribometer under stationary and transient regimes. The experimental results were validated by comparing the temperature data obtained by the acicular thermocouple, conventional thermocouples and infrared thermography. It was found that the measurements conducted with the acicular thermocouples are test-retest reliable for copper and a brake pads material, whereas they are not reliable for a polyamide. The temperature rise measured with the acicular thermocouple deviates from that registered by infrared thermography by 7–15% for copper and 10–19% for the brake pads material.

  • Reliable EM-driven size reduction of antenna structures by means of adaptive penalty factors
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    2022 Full text IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION

    Miniaturization has become of paramount importance in the design of modern antenna systems. In particular, compact size is essential for emerging application areas such as internet of things, wearable and implantable devices, 5G technology, or medical imaging. On the other hand, reduction of physical dimensions generally has a detrimental effect on antenna performance. From the perspective of numerical optimization, miniaturization is a heavily constrained problem, with most constraints being expensive to evaluate due to involving full-wave electromagnetic (EM) simulation. A convenient way of handling such a task is a penalty function approach where constraint violations contribute, upon suitable scaling, to the primary objective, i.e., the antenna size. The penalty coefficients determining the aforementioned contributions are normally adjusted through engineering experience, which does not allow for a reliable control of antenna performance figures. This paper proposes an efficient management scheme for adaptive adjustment of penalty coefficients, which eliminates the need for objective function setup by trial and error, and ensures precise control of the design constraints. Our approach is demonstrated using three broadband antennas optimized for minimum size with acceptance thresholds imposed on the in-band matching level. The adaptive adjustment of penalty coefficients is shown to outperform experience-driven setups in terms of constraint control precision and the final design quality.

  • Remarks on use of the term “deep eutectic solvent” in analytical chemistry
    • Vasil Andruch
    • Patrycja Makoś-Chełstowska
    • Justyna Płotka-Wasylka
    2022 Full text MICROCHEMICAL JOURNAL

    About 20 years ago, Abbott and co-workers researched new solvents that were based on mixtures of choline chloride with urea and carboxylic acids and that were liquid at ambient temperature. The term “deep eutectic solvent” (DES) was later adopted for similar mixtures. As DESs have a number of interesting features, they quickly attracted the attention of researchers and found application in various branches of chemical and materials research. To date, various definitions of DES have been proposed. Nevertheless, there are still differing views among researchers on what a DES really is and what exact properties a mixture must have in order to be included into this group. The prefix “deep” should only be used for deep eutectic solvents with melting points significantly below ideal predictions. Otherwise, the simpler term “eutectic solvent” (ES) should be used. It therefore follows that in order to correctly assign a solvent to the DES or ES group, a phase diagram must be available to evaluate the deviation from the ideality, as well as to quantify the DES’s liquid window. The term DES is now commonly used in analytical chemistry, but authors rarely go into a detailed examination of a DES from the viewpoint of whether it actually is a DES or an ES. Instead, they logically focus mainly on the analytical part, that is, on taking advantage of the benefits that the DES provides. Therefore, it may happen that the solvent used is designated as a DES, even if it does not meet all the necessary requirements. Of course, we cannot or should not expect analytical chemists to do a detailed study of the physical properties of DESs in addition to solving analytical tasks, although we should encourage analysts to pay due attention to the correct use of the terms (D)ES in their publications, as it would certainly help further development in the utilization of DESs in various areas, not just in analytics.

  • Remote Health Monitoring of Wind Turbines Employing Vibroacoustic Transducers and Autoencoders
    • Andrzej Czyżewski
    2022 Full text Frontiers in Energy Research

    Implementation of remote monitoring technology for real wind turbine structures designed to detect potential sources of failure is described. An innovative multi-axis contactless acoustic sensor measuring acoustic intensity as well as previously known accelerometers were used for this purpose. Signal processing methods were proposed, including feature extraction and data analysis. Two strategies were examined: Mel Frequency Cepstral Coefficients pruned with principal component analysis and autoencoder-based feature extraction. The scientific experiment resulted in data gathering and analysis to predict potential wind turbine mechanism failures.

  • Remote Work Support Needs of Employees with Autism Spectrum Disorder in Poland: Perspectives of Individuals with Autism and Their Coworkers
    • Michał Tomczak
    • Elias Mpofu
    • Nathan Hutson
    2022 Full text International Journal of Environmental Research and Public Health

    Background and Aims: With remote work becoming more common across industries, employees with autism may experience different work support needs from neurotypical peers. However, the specific remote work needs of this group of employees are underexplored in the literature. We aim to propose ways to assess workplace digital adaptation needs for individuals with autism and a framework for communicating these needs to employers. Methods: This qualitative study included interviews with 13 Polish business professionals, including coworkers and/or supervisors of employees with autism (n = 9) and female employees with autism (n = 4), about their remote work support needs. Participants responded to semi-structured interview questions identifying advantages and risk factors associated with remote work for this specific group of employees. Results: Participants reported advantages of remote work, such as limiting sensory overload and intensive interpersonal contacts, indirect interpersonal communications, flexible work hours, and eliminating the need to travel to work. Participants also reported challenges of remote work, such as reducing wanted or helpful social contacts, engaging in direct electronic communications, limiting opportunities to learn from other employees, and managing work–life balance. Conclusion: These findings suggest a need for an autism-inclusive digitalized remote work design customized to the unique needs of employees on the autism spectrum. Business managers would be key partners in the design of autism-inclusive digitalized remote work systems. Additional research is needed with larger and more diverse samples of employees with autism.

  • Removal of diphenols using pine biochar. Kinetics, equilibrium, thermodynamics, and mechanism of uptake
    • Nilton F.G.M. Cimirro
    • Eder C. Lima
    • Mariene R. Cunha
    • Pascal S. Thue
    • Alejandro Grimm
    • Glaydson S. dos Reis
    • Navid Rabiee
    • Mohammad Saeb
    • Farhad Keivanimehr
    • Sajjad Habibzadeh
    2022 JOURNAL OF MOLECULAR LIQUIDS

    Thermal pyrolysis synthesized activated biochar from the Pinus elliottii sawdust (PS) at 600° C. The obtained activated biochar (PB600) was used for the removal of three diphenols, catechol (CAT), resorcinol (RES), and hydroquinone (HYD), which are utilized mainly in different industries. The PB600 was characterized by several analytical techniques. The BET surface area of 1473 m2.g−1 and a total pore volume of 0.707 cm3 g−1 was obtained. The functional groups and amount of acidic and basic groups on the biochar were determined by FTIR and Bohem titration, respectively. From the isotherm studies, it was obtained that the maximum adsorption capacities (Qmax) based on the Liu isotherm model were 419.8 (CAT 45 °C), 263.8 (RES 40 °C), and 500.9 mg g−1 (HYD 25 °C). The values of thermodynamic parameters demonstrated that CAT, RES, and HYD adsorption processes were spontaneous, exothermic, and energetically favorable, and the magnitude of ΔH° was compatible with physisorption. The CAT, RES, and HYD adsorption mechanism onto the biochar is followed by porous filling, π-π interactions, and hydrogen bonds. Subsequently, PB600 biochar was employed as a potential adsorbent for treating simulated industrial effluents in a complex matrix simulating a real industrial effluent, and the overall removal attained up to 95.97 %. In concert with the experimental results, the electronic properties of the developed adsorption systems, including frontier molecular orbitals, charge density difference, and partial density of states, were studied by the density functional theory (DFT) approach to explore the mechanism of adsorption on the activated biochar surface.

  • Removal of lead ions from wastewater using lanthanum sulfide nanoparticle decorated over magnetic graphene oxide
    • Shahabaldin Rezania
    • Amin Mojiri
    • Junboum Park
    • Nicole Nawrot
    • Ewa Wojciechowska
    • Najat Marraiki
    • Nouf S.S. Zaghloul
    2022 Full text ENVIRONMENTAL RESEARCH

    In this study, the new lanthanum sulfide nanoparticle (La2S3) was synthesized and incorporated onto magnetic graphene oxide (MGO) sheets surface to produce potential adsorbent (MGO@LaS) for efficient removal of lead ions (Pb2+) from wastewater. The synthesized MGO@LaS adsorbent was characterized using Fourier transform infrared spectroscopy, field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. The effective parameters on the adsorption process including solution pH (∼5), adsorbent dosage (20 mg), contact time (40 min), initial Pb2+ concentration and temperature were studied. The removal efficiency was obtained >95% for lead ions at pH 5 with 20 mg adsorbent. To validate the adsorption rate and mechanism, the kinetic and thermodynamic models were studied based on experimental data. The Langmuir isotherm model was best fitted to initial equilibrium concentration with a maximum adsorption capacity of 123.46 mg/g. This indicated a monolayer adsorption pattern for Pb2+ ions over MGO@LaS. The pseudo-second-order as the kinetic model was best fitted to describe the adsorption rate due to high R2 > 0.999 as compared first-order. A thermodynamic model suggested a chemisorption and physisorption adsorption mechanism for Pb2+ ions uptake into MGO@LaS at different temperatures; ΔG° < −5.99 kJ mol−1 at 20 °C and ΔG° −18.2 kJ mol−1 at 45 °C. The obtained results showed that the novel nanocomposite (MGO@LaS) can be used as an alternative adsorbent in wastewater treatment.

  • Removal of nonsteroidal anti-inflammatory drugs and analgesics from wastewater by adsorption on cross-linked β-cyclodextrin
    • Anna Skwierawska
    • Dominika Nowacka
    • Katarzyna Kozłowska-Tylingo
    2022 Full text Water Resources and Industry

    We present a method using the material in the form of cross-linked β-cyclodextrin (CD) showing high efficiency in the simultaneous removal of hazardous pollutants from sewage, such as diclofenac (DIC), ibuprofen (IBU), ketoprofen (KETO), naproxen (NAPR), salicylic acid (SALI) and tramadol (TRAM). The material is stable and particularly easy to regenerate. The sorbent probably remembers the shape of the contaminants, which increases its sorption capacity after the second use. The kinetics of the KETO adsorption process from one-, two- and three-component solutions are well described by the pseudo-second-order model. The maximum polymer capacity was 162.60 mg g−1. The interactions of KETO with CD were investigated, indicating that the main sorption mechanism is based on supramolecular interaction and uptake by a polymer network. The material is not sensitive to low pH and high salinity, so it can be used for the treatment of DIC, IBU, and KETO post-production wastewaters.

  • Removal of Volatile Organic Compounds (VOCs) from Air: Focus on Biotrickling Filtration and Process Modeling
    • Piotr Rybarczyk
    2022 Full text Processes

    Biotrickling filtration is a well-established technology for the treatment of air polluted with odorous and volatile organic compounds (VOCs). Besides dozens of successful industrial applications of this technology, there are still gaps in a full understanding and description of the mechanisms of biotrickling filtration. This review focuses on recent research results on biotrickling filtration of air polluted with single and multiple VOCs, as well as process modeling. The modeling offers optimization of a process design and performance, as well as allows deeper understanding of process mechanisms. An overview of the developments of models describing biotrickling filtration and conventional biofiltration, as primarily developed and in many aspects through similar processes, is presented in this paper.

  • Renewable and Sustainable Energy: Current State and Prospects
    • Bartłomiej Igliński
    • Michał Pietrzak
    2022 Full text ENERGIES

    The last two decades of the twentieth century represented a period of above-average, systematic growth of formal and informal interdependencies between economies of different countries and between world markets. The intensity, magnitude, and diversity of these interdependencies have never been recorded before in economic history, and the market transformations taking place have been referred to in the literature as the process of world globalization. Over the next twenty years of the 21st century, the dynamic and systematic development of globalization processes has progressed to such an extent that, in fact, a very high level of interdependence has been achieved in every sector of the economy [1]. This means that national economies for the last forty years have faced functioning in new economic conditions, forced mainly by the developing globalization processes. This has mainly contributed to a significant increase in the socio-economic development [2,3] and the associated enrichment of the populations of most economies and worldwide changes in the labor market [4]. In addition, there have been new trends in consumer attitudes [5,6], where environmental issues have begun to play a dominant role in consumer decision-making.

  • Representing and Managing Experiential Knowledge with Decisional DNA and its Drimos® Extension
    • Edward Szczerbicki
    • Cesar Sanin
    • Karina Sterling-zuluaga
    2022 Full text

    The Semantic Web concept is proposing a future concept of the WorldWideWeb (WWW) where both humans and man-made systems are able to interconnect and exchange knowledge. One of the challenges of Semantic Web is smart and trusted accommodation of knowledge in artificial systems so it can be unified, enhanced, reused, shared, communicated and distributed with added aptitude. Our research represents an important component of addressing the above challenge and exciting, cutting-edge exploration trend in the general area of developing tool for intelligence augmentation.

  • Research of Accuracy of RSSI Fingerprint-Based Indoor Positioning BLE System
    • Michał Wysocki
    • Robert Nicpoń
    • Marta Trzaska
    • Agnieszka Czapiewska
    2022

    Radio localization in indoor environment is still a challenging task due to environment volatility. In the paper are compared achieved localization accuracies for RSSI-Fingerprinting method utilizing Bluetooth Low Energy (BLE) for two different environments: large empty hall and narrow corridor. Measurements were done by 6 different smartphones of 3 different producers, which makes those measurements unique as accuracies achieved by different devices can be compared

  • Research of Accuracy of RSSI Fingerprint-Based Indoor Positioning BLE System
    • Michał Wysocki
    • Robert Nicpoń
    • Marta Trzaska
    • Agnieszka Czapiewska
    2022 Full text Przegląd Elektrotechniczny

    Radio localization in indoor environment is still a challenging task due to environment volatility. In the paper are compared achieved localization accuracies for RSSI-Fingerprinting method utilizing Bluetooth Low Energy (BLE) for two different environments: large empty hall and narrow corridor. Measurements were done by 6 different smartphones of 3 different producers, which makes those measurements unique as accuracies achieved by different devices can be compared.

  • Research on Linear Actuators for Active Foil Bearings
    • Łukasz Breńkacz
    • Rafał Kędra
    • Waldemar Janicki
    • Artur Maurin
    • Paweł Bagiński
    • Artur Andrearczyk
    • Beata Zima
    2022 Full text Materials

    Active foil bearings are a kind of gas foil bearing. They contain actuators which allow for modification of the bearing sleeve size and the shape of the lubrication gap. Rotor vibrations can be actively controlled by these changes. It is possible, among other things, to reduce the starting torque, control the vibration amplitude at different speeds and improve operational safety. Prototypes of active foil bearings are being developed based on different mechanical concepts. This paper provides an analysis of the linear mechanisms that are the base, and they are crucial for such developments. In the literature, there is a lack of characteristics of these actuators tested under real operating conditions of an active foil bearing. This article aims to fill this gap. New test rigs have been developed and used to precisely investigate the possibility of using actuators in active foil bearings. Since their geometry and control methods differ, the measurement systems have been adapted accordingly. The actuators studied were piezoelectrics, shape-memory alloys (SMAs) and stepper motors. Each of them was characterized by different operating characteristics. The results obtained allow for a comparison of the actuators. This approach is especially useful for the design and analysis of active foil bearings.

  • Residents' Perception of Intangible Benefits and Costs Associated with Hosting Major Sporting Events
    • Krystian Zawadzki
    2022 Full text Event Management

    The main purpose of this paper is to estimate on the basis of inhabitants’ perception the overall composite and aggregated scores of two major sporting events held in Ergo Arena hall, on the border of Gdańsk and Sopot, in northern Poland. The indirect aim is to identify the determinants affecting the monetary offers of the locals of the two cities. The research results unveil that major sporting events may determine the appearance of intangible social effects which are eagerly valued by the citizens of host cities. The resident’s valuation ranges between 6,08 PLN (1,96 USD) and 11,29 PLN (3,64 USD) for intangible benefits, while between 1,75 PLN (0,56 USD) and 2,21 PLN (0,71 USD) for intangible costs, depending on the city and the event. The results determines an increase in the values of intangible net benefits. The amount of net intangible benefit is much lower than in the case of mega sporting events. Nevertheless, it is more likely to host many major sporting events in a short time in one place. The regression analysis shows that the decision to allocate funds to support the Championships in 2016 and 2017 in Gdańsk/Sopot was made by people with high incomes, who expressed an interest in sport, but not necessarily in the sports discipline, and perceived intangible benefits, in particular civic pride and the feel-good factor. In turn, the level of WTPcost was particularly high among people with high incomes who perceived the threats connected with the hosting of a major sporting event.

  • Residents’ Perception of Intangible Benefits and Costs Associated with Hosting Major Sporting Events
    • Krystian Zawadzki
    2022 Full text Event Management

    The main purpose of this paper is to estimate on the basis of inhabitants’ perception the overall composite and aggregated scores of two major sporting events held in Ergo Arena hall, on the border of Gdańsk and Sopot, in northern Poland. The indirect aim is to identify the determinants affecting the monetary offers of the locals of the two cities. The research results unveil that major sporting events may determine the appearance of intangible social effects which are eagerly valued by the citizens of host cities. The resident’s valuation ranges between 6,08 PLN (1,96 USD) and 11,29 PLN (3,64 USD) for intangible benefits, while between 1,75 PLN (0,56 USD) and 2,21 PLN (0,71 USD) for intangible costs, depending on the city and the event. The results determines an increase in the values of intangible net benefits. The amount of net intangible benefit is much lower than in the case of mega sporting events. Nevertheless, it is more likely to host many major sporting events in a short time in one place. The regression analysis shows that the decision to allocate funds to support the Championships in 2016 and 2017 in Gdańsk/Sopot was made by people with high incomes, who expressed an interest in sport, but not necessarily in the sports discipline, and perceived intangible benefits, in particular civic pride and the feel-good factor. In turn, the level of WTPcost was particularly high among people with high incomes who perceived the threats connected with the hosting of a major sporting event.

  • Residual current devices in installations with PV energy sources
    • Stanisław Czapp
    2022 Full text Przegląd Elektrotechniczny

    The paper presents the principles of residual current devices (RCDs) application in photovoltaic (PV) installations. Provisions of standards in this regard are commented on, in particular, attention is drawn to the lack of obligation to use of RCDs in PV installations. The issue of the shape of the earth fault current and the level of leakage currents in such installations are discussed. These factors influence the selection of RCDs in terms of their rated residual operating current as well as the type of tripping characteristic.

  • Residual Current Devices: Selection, Operation, and Testing
    • Stanisław Czapp
    2022

    In this book, the idea for residual current protection has been presented. The evolution in construction types of residual current devices, which has taken place over decades, is discussed. Types and functional properties of the contemporary residual current devices are described. The main parameters of these devices, from the point of view of their selection and application, are indicated. Special constructions of the protective devices, among other portable and socket-outlets residual devices, are described. The reliability of residual current devices and main sources of their defects are discussed. The rules of backup protection of residual current devices without integrated overcurrent protection are presented. The application of residual current devices in TN, TT, and IT low-voltage systems is commented upon. Requirements of the standards, regarding the obligatory use of residual current devices, are quoted. The principles of application of residual current devices in protection in case of a fault, additional protection, as well as protection against fire, are explained. As extended information related to the use of residual current devices in protection against fire, arc fault detection devices are described, which can be treated as complementary protective devices especially in the case of dangerous series arcing. The issue of residual current devices’ operation in circuits with nonsinusoidal currents is commented in detail. Residual current devices also make difficulties during an earth fault loop impedance measurement, which is one of the commonly performed measurements to verify the effectiveness of protection against electric shock by automatic disconnection of the supply. The sources of unwanted tripping of the devices, during this type of measurement, are indicated and suitable methods of measurement are shown. Immunity of residual current devices to the impulse leakage currents is discussed. Moreover, coordination of residual current devices with surge protective devices is commented upon. Principles of residual current devices’ verifications, examples of their results, as well as fault diagnosis in circuits with these devices are described. At the end of the book, Appendix A presents examples of residual current devices’ selection. Additionally, Appendix B covers a list of the standards regarding residual current devices’ performance, application, and operation.

  • Resistant to correlated noise and outliers discrete identification of continuous non-linear non-stationary dynamic objects
    • Janusz Kozłowski
    • Zdzisław Kowalczuk
    2022

    In this article, specific methods of parameter estimation were used to identify the coefficients of continuous models represented by linear and nonlinear differential equations. The necessary discrete-time approximation of the base model is achieved by appropriately tuned FIR linear integral filters. The resulting discrete descriptions, which retain the original continuous parameterization, can then be identified using the classical least squares procedure. Since, in the presence of correlated noise, the relevant parameter estimates suffer from an asymptotic systematic error, the instrumental variable method is used here to significantly improve the consistency of the estimates. The finally applied algorithm based on the criterion of the smallest sum of absolute values is used to identify linear and nonlinear models in the presence of sporadic measurement errors. In summary, the effectiveness of the proposed solutions is demonstrated by means of numerical simulations.

  • Resistant to correlated noise and outliers discrete identification of continuous non-linear non-stationary dynamic objects
    • Janusz Kozłowski
    • Zdzisław Kowalczuk
    2022

    In this study, dedicated methods of parameter estimation were used to identify the coefficients of continuous models represented by linear and nonlinear differential equations. The necessary discrete-time approximation of the base model is achieved by appropriately tuned FIR linear integral filters. The resulting discrete descriptions, which retain the original continuous parameterization, can then be identified using the classical least squares procedure. Since, in the presence of correlated noise, the relevant parameter estimates suffer from an asymptotic systematic error, the instrumental variable method is used here to significantly improve the consistency of the estimates. The finally applied algorithm based on the criterion of the smallest sum of absolute values is used to identify linear and nonlinear models in the presence of sporadic measurement errors. In summary, the effectiveness of the proposed solutions is demonstrated by means of numerical tests.

  • Rethinking Sustainable Cities at Night: Paradigm Shifts in Urban Design and City Lighting
    • Karolina Zielińska-Dąbkowska
    • Katarzyna Bobkowska
    2022 Full text Sustainability

    Since the establishment of the 17 Sustainable Development Goals (SDGs) by the United Nations General Assembly in 2015, various perspectives on sustainable cities have been developed and adopted in order to achieve a better and more sustainable future. However, background research has revealed that these goals and targets are limited because they do not take into account the growing body of lighting-related research in diverse fields on the impact of outdoor illumination on humans, flora and fauna. Recently, exterior lighting has been also linked to environmental degradation and as an indirect contributor to the current climate change emergency. Therefore, this study aims, by using online interviews with over 50 experts who work in the field of artificial light at night (ALAN), to assess whether the SDG objectives adequately reflect the latest knowledge about sustainable cities. The Elsevier 2021 SDG mapping matrix was used to find the correlation between the keywords that define each SDG and the keywords used by a group of international experts. This work suggests there are missing targets in current SDGs, especially SDG 11, connected to sustainable cities and communities. It also offers useful guidance on how to rethink the existing approach of cities that aim for sustainability, by applying eight (8) key aspects of urban lighting for healthier and environmentally responsible outdoor illumination, by means of a correct design process, along with a five-step strategic plan of action. The crucial role of multidisciplinary and interdisciplinary collaboration with experts has also been outlined, via the inclusion of new actors such as lighting professionals and researchers, who are currently absent in this important discourse

  • Reversible data hiding in encrypted DICOM images using sorted binary sequences of pixels
    • Mariusz Dzwonkowski
    • Bartosz Czaplewski
    2022 SIGNAL PROCESSING

    In this paper, a novel reversible data hiding method for encrypted DICOM images is proposed. The method utilizes binary decomposition of the input data paired with a sorting process of the obtained binary sequences to ensure efficient data embedding in each predefined data block for specific most significant bit (MSB) planes while exploiting the properties of run-length encoding. The proposed scheme is lossless, and based on the receiver's privileges, allows separate or simultaneous recovery of the original and embedded data. The proposed method was originally designed for 16-bit DICOM images of monochrome photometric interpretation, however it can be used with any type of data while providing satisfactory results. A computer-based analysis has been carried out and simulation results for DICOM and non-DICOM images are shown at the end of this paper.

  • Review of cigars and cigar-type products as potential sources of consumer exposure to heavy metals
    • Paweł Hać
    • Bartłomiej Cieślik
    • Piotr Konieczka
    2022 Full text JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART C-ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS

    The popularity of cigars, growing since 1993, has not gone hand in hand with the increased interest of researchers in these products. Although the literature widely describes the harmfulness of tobacco and the content of toxic substances in tobacco products, the topic is often treated selectively as relating primarily to cigarettes and rarely extends to other products of the broadly defined tobacco industry. However, there is no reason to marginalize the harmful effects of other nicotine products, (which include tobacco products such as cigars). The study analyzed the available literature on the con- tent of selected heavy metals in cigar tobacco. Among the heavy metals, the following contents of elements in tobacco were recorded in cigars: Fe (420–2200mg/g), Mn (100–370mg/ g), Zn (14–180 mg/g), Cu (15–140 mg/g), Pb (not detec- ted–32mg/g), Cd (nd–19mg/g), Ni (nd–13mg/g), Cr (nd–10mg/ g), Co (0.65–1.0 mg/g), As (nd–0.66 mg/g), Hg (18–25 ng/g). Importantly, the values often differ between cigars of different origins and types, indicating the need for more extensive research.