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Gdańsk University of Technology

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  • Rectangular Waveguide Filters Based on Deformed Dual-Mode Cavity Resonators
    • Michał Baranowski
    • Łukasz Balewski
    • Adam Lamęcki
    • Michał Mrozowski
    2023 Full text

    In this paper, a novel design for rectangular waveguide filters with deformed dual-mode (DM) cavity resonators is demonstrated. The new resonant cavity shape is a result of applying shape deformation to the basic rectangular cavity to enable its dual-mode operation. Internal coupling between the two orthogonal cavity modes is realized by geometry deformation, eliminating the need for additional coupling elements. The designs are developed within the constraints of 3-D printing to allow their fabrication in one piece. In addition, the design method used results in models with smooth surfaces, which is highly desirable for high-power and low-loss applications. A deformed DM cavity is analyzed and a single cavity second-order filter is designed and presented. Finally, two types of fourth-order filters with transmission zeros are designed by combining two deformed DM cavities and their performance is verified experimentally by a 3D-printed prototype.

  • Recycling of photovoltaic modules - legal status, technology, market prospects
    • Jakub Łukasik
    • Jan Wajs
    2023 Rynek Energii

    The increase in the number of manufactured and installed photovoltaic modules and the growing concern about the insufficient supply of pure silicon imply the need to take action to develop infrastructure for recycling PV modules. The article presents a multifaceted analysis of the current state of development of the photovoltaic module recycling sector from a global and national perspective. The essence of the issue was introduced in the context of the rapid growth of the solar energy sector in recent years. Various technologies for the production of PV cells were presented, categorized according to their generations. The available methods of recycling the most popular on the market silicon crystal modules (I generation) and thin-film modules (II generation) were presented, as well as innovative techniques that are currently in the stage of laboratory research. The current legal status dedicated to recycling processes and requirements for effective waste processing are discussed. In the face of the ongoing energy transformation and forecasts on the increase in installed capacity in photovoltaics in Poland and worldwide, the prospects for the development of this market in the future have been outlined.

  • Red Kale (Brassica oleracea L. ssp. acephala L. var. sabellica) Induces Apoptosis in Human Colorectal Cancer Cells In Vitro
    • Kamila Rachwał
    • Iwona Niedźwiedź
    • Adam Waśko
    • Tomasz Laskowski
    • Paweł Szczeblewski
    • Wirginia Kukula-Koch
    • Magdalena Polak-Berecka
    2023 Full text MOLECULES

    This article presents the results of studies investigating the effect of red kale (Brassica oleracea L. ssp. acephala L. var. sabellica) extract on cancer cells (HT-29). The cytotoxicity of the red kale extract was assessed using MTT and LDH assays, while qRT-PCR was employed to analyze the expression of genes associated with the p53 signaling pathway to elucidate the effect of the extract on cancer cells. Furthermore, HPLC-ESI-QTOF-MS/MS was applied to identify bioactive com- pounds present in red kale. The obtained results indicated that red kale extract reduced the viability and suppressed the proliferation of HT-29 cells (the IC50 value of 60.8 μg/mL). Additionally, mRNA expression analysis revealed significant upregulation of several genes, i.e., casp9, mapk10, mapk11, fas, kat2 b, and ubd, suggesting the induction of cell apoptosis through the caspase-dependent path- way. Interestingly, the study revealed a decrease in the expression of genes including cdk2 and cdk4 encoding cell cycle-related proteins, which may lead to cell cycle arrest. Furthermore, the study identified certain bioactive compounds, such as sinigrin, spirostanol, hesperetin and usam- barensine, which could potentially contribute to the apoptotic effect of red kale extracts. However, further investigations are necessary to elucidate the specific role of these individual compounds in the anti-cancer process.

  • Rediscovering Automatic Detection of Stuttering and Its Subclasses through Machine Learning—The Impact of Changing Deep Model Architecture and Amount of Data in the Training Set
    • Piotr Filipowicz
    • Bożena Kostek
    2023 Full text Applied Sciences-Basel

    This work deals with automatically detecting stuttering and its subclasses. An effective classification of stuttering along with its subclasses could find wide application in determining the severity of stuttering by speech therapists, preliminary patient diagnosis, and enabling communication with the previously mentioned voice assistants. The first part of this work provides an overview of examples of classical and deep learning methods used in automated stuttering classifications as well as databases and features used. Then, two classical algorithms (k-NN (k-nearest neighbor) and SVM (support vector machine) and several deep models (ConvLSTM; ResNetBiLstm; ResNet18; Wav2Vec2) are examined on the available stuttering dataset. The experiments investigate the influence of individual signal features such as Mel-Frequency Cepstral Coefficients (MFCCs), pitch-determining features in the signal, and various 2D speech representations on the classification results. The most successful algorithm, i.e., ResNet18, can classify speech disorders at the F1 measure of 0.93 for the general class. Additionally, deep learning shows superiority over a classical approach to stuttering disorder detection. However, due to insufficient data and the quality of the annotations, the results differ between stuttering subcategories. Observation of the impact of the number of dense layers, the amount of data in the training set, and the amount of data divided into the training and test sets on the effectiveness of stuttering event detection is provided for further use of this methodology.

  • Reduced-Cost Microwave Modeling Using Constrained Domains and Dimensionality Reduction
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    • Ullah Ubaid
    2023 Full text Scientific Reports

    Development of modern microwave devices largely exploits full-wave electromagnetic (EM) simulations. Yet, simulation-driven design may be problematic due to the incurred CPU expenses. Addressing the high-cost issues stimulated the development of surrogate modeling methods. Among them, data-driven techniques seem to be the most widespread owing to their flexibility and accessibility. Nonetheless, applicability of approximation-based modeling for real-world microwave components is hindered by a high nonlinearity of the system characteristics, dimensionality issues, and broad ranges of operating parameters the model should cover to make it practically useful. Performance-driven modeling frameworks deliver a partial mitigation of these problems through appropriate spatial orientation of the metamodel domain, which only encapsulates high-quality designs and not the entire space. Unfortunately, the initial model setup cost is high, as defining the domain requires database designs that need to be a priori acquired. This paper introduces a novel approach, where the database designs are replaced by random observables, and dimensionality of the domain is reduced using spectral analysis thereof. The major contributions of the work include implementation of the explicit dimensionality reduction of the confined surrogate model domain and introducing this concept into a complete cost-efficient framework for modeling of microwave components. Comprehensive benchmarking demonstrates excellent performance of the introduced framework, both in terms of predictive power of the rendered surrogates, their scalability properties, as well as low computational overhead associated with the model setup.

  • Reducing nighttime light exposure in the urban environment to benefit human health and society
    • Karolina Zielińska-Dąbkowska
    • Eva S. Schernhammer
    • John, P. Hanifin
    • George Brainard
    2023 SCIENCE

    Nocturnal light pollution can have profound effects on humans and other organisms. Recent research indicates that nighttime outdoor lighting is increasing rapidly. Evidence from controlled laboratory studies demonstrates that nocturnal light exposure can strain the visual system, disrupt circadian physiology, suppress melatonin secretion, and impair sleep. There is a growing body of work pointing to adverse effects of outdoor lighting on human health, including the risk of chronic diseases, but this knowledge is in a more nascent stage. In this Review, we synthesize recent research on the context-specific factors and physiology relevant to nocturnal light exposure in relation to human health and society, identify critical areas for future research, and highlight recent policy steps and recommendations for mitigating light pollution in the urban environment.

  • Reducing the Uncertainty of the Moving Object Location Measurement with the Method of Quasi-Multiple Measurement in GNSS Technology in Symmetrical Arrangement
    • Jacek Skibicki
    • Andrzej Wilk
    • Władysław Koc
    • Roksana Licow
    • Jacek Szmagliński
    • Piotr Chrostowski
    • Sławomir Judek
    • Krzysztof Karwowski
    • Sławomir Grulkowski
    2023 Full text SENSORS

    The article presents a solution to the problem of limited accuracy of dynamic measurements performed with GNSS receivers. The proposed measurement method is a response to the needs related to the assessment of the measurement uncertainty of the position of the track axis of the rail transport line. However, the problem of reducing the measurement uncertainty is universal for many different situations where high accuracy of positioning of objects is required, especially in motion. The article proposes a new method to determine object’s location using geometric constraints of a number of GNSS receivers arranged in symmetric configuration. The proposed method has been verified by comparing signals recorded by up to five GNSS receivers during stationary and dynamic measurements. The dynamic measurement was made on a tram track within the framework of a cycle of studies upon effective and efficient methods to catalogue and diagnose tracks. A detailed analysis of the results obtained with the quasi-multiple measurement method confirms remarkable reduction in their uncertainty. Their synthesis shows the usability of this method in dynamic conditions. The proposed method is expected to find application in measurements requiring high accuracy, and in case of deterioration of the signal quality from satellites by one or more of GNSS receivers due to the appearance of natural obstacles.

  • Reduction in Errors in Roughness Evaluation with an Accurate Definition of the S-L Surface
    • Przemysław Podulka
    • Wojciech Macek
    • Ricardo Branco
    • Reza Masoudi Nejad
    2023 Full text Materials

    Characterization of surface topography, roughly divided into measurement and data analysis, can be valuable in the process of validation of the tribological performance of machined parts. Surface topography, especially the roughness, can respond straightly to the machining process and, in some cases, is defined as a fingerprint of the manufacturing. When considering the high precision of surface topography studies, the definition of both S-surface and L-surface can drive many errors that influence the analysis of the accuracy of the manufacturing process. Even if precise measuring equipment (device and method) is provided but received data are processed erroneously, the precision is still lost. From that matter, the precise definition of the S-L surface can be valuable in the roughness evaluation allowing a reduction in the rejection of properly made parts. In this paper, it was proposed how to select an appropriate procedure for the removal of the L- and S- components from the raw measured data. Various types of surface topographies were considered, e.g., plateau-honed (some with burnished oil pockets), turned, milled, ground, laser-textured, ceramic, composite, and, generally, isotropic. They were measured with different (stylus and optical) methods, respectively, and parameters from the ISO 25178 standard were also taken into consideration. It was found that commonly used and available commercial software methods can be valuable and especially helpful in the precise definition of the S-L surface; respectively, its usage requires an appropriate response (knowledge) from the users.

  • Reduction of CO2 Emissions from Offshore Combined Cycle Diesel Engine-Steam Turbine Power Plant Powered by Alternative Fuels
    • Wojciech Olszewski
    • Marek Dzida
    • Van Giao Nguyen
    • Dao Nam Cao
    2023 Full text Polish Maritime Research

    Diverse forms of environmental pollution arise with the introduction of materials or energy that exert adverse effects on human health, climate patterns, ecosystems, and beyond. Rigorous emission regulations for gases resulting from fuel combustion are being enforced by the European Union and the International Maritime Organization (IMO), directed at maritime sectors to mitigate emissions of SOx, NOx, and CO2. The IMO envisions the realisation of its 2050 targets through a suite of strategies encompassing deliberate reductions in vessel speed, enhanced ship operations, improved propulsion systems, and a transition towards low and zero-emission fuels such as LNG, methanol, hydrogen, and ammonia. While the majority of vessels currently depend on heavy fuel or low-sulphur fuel oil, novel designs integrating alternative fuels are gaining prominence. Technologies like exhaust gas purification systems, LNG, and methanol are being embraced to achieve minimised emissions. This study introduces the concept of a high-power combined ship system, composed of a primary main engine, a diesel engine, and a steam turbine system, harnessing the energy contained within the flue gases of the main combustion engine. Assumptions, constraints for calculations, and a thermodynamic evaluation of the combined cycle are outlined. Additionally, the study scrutinises the utilisation of alternative fuels for ship propulsion and their potential to curtail exhaust emissions, with a specific focus on reducing CO2 output

  • Reduction of exceeding the guaranteed service time for external trucks at the DCT Gdańsk container terminal using a six sigma framework
    • Karol Moszyk
    • Mariusz Deja
    2023 Full text International Journal of Lean Six Sigma

    Purpose The purpose of this research was to investigate ways to reduce the average amount of exceeded guaranteed service time for external trucks at Deepwater Container Terminal Gdańsk Sp z o.o. (DCT Gdańsk) via dosing the gate activities, in particular IN-Gate entry process of trucks carrying import/export/transit containers. Design/methodology/approach A Six Sigma methodology with the DMAIC methods along with the SIPOC chart, cause and effect diagram, scatterplot, benchmark and brainstorming and finally multi-voting tool are used as analyses tools in this research. Findings Deepwater Container Terminal Gdańsk Sp z o.o. (DCT Gdańsk) reorganized and modernized the Gate Operations. Gate reorganization and modernization includes streaming line traffic at the gates, external parking lot optimization, implementation of dedicated supporting software and installation of dedicated CCTV cameras to provide 24h life view. During gates development, the external truck service times data were collected and analysed. The obtained materials concerned the measurement of the average truck turnaround time before and after the implementation of the improvements. Originality/value The proposed approach of reducing the average amount of exceeded guaranteed service time of external trucks at the container terminal is unique and relatively cheap mainly due to organisational changes with some widely available low-cost investments and can be applied on a different scale to other container terminals or to transport and logistics companies.

  • Reemission of inorganic pollution from permafrost? A freshwater hydrochemistry study in the lower Kolyma basin (North-East Siberia)
    • Danuta Szumińska
    • Kozioł Krystyna
    • Sergey R. Chalov
    • Vasilii A. Efimov
    • Marcin Frankowski
    • Sara Lehmann-konera
    • Żaneta Polkowska
    2023 LAND DEGRADATION & DEVELOPMENT

    Permafrost regions are under particular pressure from climate change resulting in widespread landscape changes, which impact also freshwater chemistry. We investi- gated a snapshot of hydrochemistry in various freshwater environments in the lower Kolyma river basin (North-East Siberia, continuous permafrost zone) to explore the mobility of metals, metalloids and non-metals resulting from permafrost thaw. Partic- ular attention was focused on heavy metals as contaminants potentially released from the secondary source in the permafrozen Yedoma complex. Permafrost creeks represented the Mg-Ca-Na-HCO3-Cl-SO 4 ionic water type (with mineralisation in the range 600–800 mg L1 ), while permafrost ice and thermokarst lake waters were the HCO 3-Ca-Mg type. Multiple heavy metals (As, Cu, Co, Mn and Ni) showed much higher dissolved phase concentrations in permafrost creeks and ice than in Kolyma and its tributaries, and only in the permafrost samples and one Kolyma tributary we have detected dissolved Ti. In thermokarst lakes, several metal and metalloid dis- solved concentrations increased with water depth (Fe, Mn, Ni and Zn – in both lakes; Al, Cu, K, Sb, Sr and Pb in either lake), reaching 1370 μg L1 Cu, 4610 μg L1 Mn, and 687 μg L1 Zn in the bottom water layers. Permafrost-related waters were also enriched in dissolved phosphorus (up to 512 μg L1 in Yedoma-fed creeks). The impact of permafrost thaw on river and lake water chemistry is a complex problem which needs to be considered both in the context of legacy permafrost shrinkage and the interference of the deepening active layer with newly deposited anthropogenic contaminants.

  • Reinforcing and plasticizing effects of reclaimed rubber on the vulcanization and properties of natural rubber
    • Teng Ren
    • Pan Song
    • Weihong Yang
    • Krzysztof Formela
    • Shifeng Wang
    2023 JOURNAL OF APPLIED POLYMER SCIENCE

    The production of high-added value reclaimed rubber (RR) is of great signifi-cance for the sustainability of rubber industries. To green recycle waste rub-bers and broaden the application of RR, a RR material with potentialreinforcing and plasticizing effects on nature rubber (NR) composites are pre-pared by a thermo-oxidative reclamation process. The reclamation degree ofRR is controlled by adjusting the content of soybean oil. The plasticizing effectis demonstrated by the decrease of torque during vulcanization and theenhancement of elongation at break of NR/RR composites with the increasingreclamation of RR. The tensile strength of NR/RR composites is enhanced byadding the RR, and the existence of RR also improves the thermal stability andrheological properties of NR/RR composites. The formation of new bound rub-ber in NR/RR compound indicates the reinforcing ability of RR. In addition,the average particle size of RR reaches nano-scale according to scanning elec-tron microscope photographs and its dispersion in NR/RR compounds isimproved with the increasing reclamation degree of RR as shown in Payneeffect. This work demonstrates the reinforcing and plasticizing ability of theRR, which is beneficial to improving the added value of reclaimed and broad-ening its application.

  • Rekordowe liczby pierwsze
    • Marek Kubale
    2023 Pismo PG

    Problem liczb pierwszych ma długą historię sięgającą czasów starożytnych. W śród liczb całkowitych liczby pierwsze grają rolę analogiczną do pierwiastków w chemii.

  • Relationship between Chemical Structure and Biological Activity Evaluated In Vitro for Six Anthocyanidins Most Commonly Occurring in Edible Plants
    • Izabela Koss-Mikołajczyk
    • Agnieszka Bartoszek-Pączkowska
    2023 Full text MOLECULES

    Numerous studies have provided evidence that diets rich in anthocyanins show a broad spectrum of health benefits. Anthocyanins in nature are usually found in the form of glycosides. Their aglycone forms are called anthocyanidins. The chemical structure of anthocyanins is based on the flavylium cation, but they differ in the position and number of substituents. However, the bioactives and foods that contain them are frequently treated as a uniform group of compounds exhibiting the same biological activity, without paying attention to the structural differences between individual anthocyanidins. The aim of this study was to find out how structural differences impact the biological activity of the six most common dietary anthocyanidins, i.e., delphinidin (Dp), petunidin (Pt), cyanidin (Cd), malvidin (Mv), pelargonidin (Pg) and peonidin (Po). The study concentrated on redox-related phenomena and compared the following parameters: antioxidant activity (measured using various methods: spectrophotometric tests (ABTS, DPPH), ORAC assay and CAA test (cellular antioxidant activity)), the ability to inhibit growth of human colon cancer cells (HT29; determined using MTT assay), and the ability of studied compounds to protect DNA from oxidative damage (comet assay). Based on the obtained results, the relationship between the structure of studied antho- cyanidins and their biological activity was assessed. The obtained results revealed that the number and position of the hydroxyl and methoxy groups in the anthocyanidin structure strongly influenced not only the color of anthocyanidins but most of all their antioxidant and biological activities.

  • Release of Encapsulated Bioactive Compounds from Active Packaging/Coating Materials and Its Modeling: A Systematic Review
    • Shahida Anusha Siddiqui
    • Shubhra Singh
    • Nur Alim Bahmid
    • Taha Mehany
    • Douglas J. H. Shyu
    • Elham Assadpour
    • Narjes Malekjani
    • Roberto Castro Munoz
    • Seid Mahdi Jafari
    2023 Full text Colloids and Interfaces

    The issue of achieving controlled or targeted release of bioactive compounds with specific functional properties is a complex task that requires addressing several factors, including the type of bioactive, the nature of the delivery system, and the environmental conditions during transportation and storage. This paper deals with extensive reporting for the identification of original articles using Scopus and Google Scholar based on active packaging as a novel packaging technology that controls the release of antimicrobial agents encapsulated into carriers in the food packaging systems. For evidence-based search, the studies were extracted from 2015 to 2020 and screened using the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Following the review and screening of publications, 32 peer-reviewed articles were subjected to systematic analysis. The preliminary search indicated that the encapsulation of bioactives enhances their bioavailability and stability. From a theoretical viewpoint, mathematical models play an important role in understanding and predicting the release behavior of bioactives during transportation and storage, thus facilitating the development of new packaging material by a systematic approach. However, only a few studies could formulate parameters for mathematical models in order to achieve the specific release mechanism regulated for the quality and safety of foods. Therefore, this paper will cover all encapsulation approaches, active packaging, and mathematical modeling in the food industry into structural form and analyze the challenges faced by the complex nature of active packaging in real food systems.

  • Release systems based on self-assembling RADA16-I hydrogels with a signal sequence which improves wound healing processes
    • Maria Dzierżyńska
    • Justyna Sawicka
    • Milena Deptula
    • Paweł Sosnowski
    • Piotr Sass
    • Barbara Peplińska
    • Zuzanna Pietralik-Molińska
    • Martyna Fularczyk
    • Franciszek Kasprzykowski
    • Jacek Zieliński
    • Maciej Kozak
    • Paweł Sachadyn
    • Michal Pikula
    • Sylwia Rodziewicz-Motowidło
    2023 Full text Scientific Reports

    Self-assembling peptides can be used for the regeneration of severely damaged skin. They can act as scaffolds for skin cells and as a reservoir of active compounds, to accelerate scarless wound healing. To overcome repeated administration of peptides which accelerate healing, we report development of three new peptide biomaterials based on the RADA16-I hydrogel functionalized with a sequence (AAPV) cleaved by human neutrophil elastase and short biologically active peptide motifs, namely GHK, KGHK and RDKVYR. The peptide hybrids were investigated for their structural aspects using circular dichroism, thiofavin T assay, transmission electron microscopy, and atomic force microscopy, as well as their rheological properties and stability in diferent fuids such as water or plasma, and their susceptibility to digestion by enzymes present in the wound environment. In addition, the morphology of the RADA-peptide hydrogels was examined with a unique technique called scanning electron cryomicroscopy. These experiments enabled us to verify if the designed peptides increased the bioactivity of the gel without disturbing its gelling processes. We demonstrate that the physicochemical properties of the designed hybrids were similar to those of the original RADA16-I. The materials behaved as expected, leaving the active motif free when treated with elastase. XTT and LDH tests on fibroblasts and keratinocytes were performed to assess the cytotoxicity of the RADA16-I hybrids, while the viability of cells treated with RADA16-I hybrids was evaluated in a model of human dermal fibroblasts. The hybrid peptides revealed no cytotoxicity; the cells grew and proliferated better than after treatment with RADA16-I alone. Improved wound healing following topical delivery of RADA-GHK and RADA-KGHK was demonstrated using a model of dorsal skin injury in mice and histological analyses. The presented results indicate further research is warranted into the engineered peptides as scaffolds for wound healing and tissue engineering.

  • Reliability Analysis of Data Storage Using Survival Signature and Logic Differential Calculus
    • Patrik Rusnak
    • Peter Sedlacek
    • Stanisław Czapp
    2023

    The Data storage system is an important part of any information system. All the necessary data that must be available for the successful operation of the information system are stored here. Therefore, it is advisable to think about the reliability of such a data storage system. As part of reliability engineering, it is possible to perform a reliability analysis of any system. Therefore, the data storage system can be analyzed as well. As part of the reliability analysis, it is necessary to select the mathematical representation of the analyzed system. One such form is the structure function. A structure function is a mathematical representation of the analyzed system that maps the state of a system based on the state of its components. Main advantage is that the structure function can be used to describe a system of any complexity. However, if we have components of the same type in the system, the survival signature may be used as well. The structure function as well as the survival signature permits the use of multiple mathematical approaches such as logic differential calculus. Logic differential calculus can be used to detect situations where a change in the number of working components affects a change in the state of the system. This is useful in importance analysis, which is a part of the reliability analysis. In this paper, a reliability analysis will be performed for data storage in which multiple types of hard disk drives can be used as well as multiple methods of storing data on multiple disks using redundant array of independent disks.

  • Reliability estimation of underground horizontal fuel tank limit states
    • Przemysław Sorn
    • Mateusz Sondej
    • Jarosław Górski
    2023 Full text Bulletin of the Polish Academy of Sciences-Technical Sciences

    Fuel tanks are designed with regard to standard loads and operating conditions. The investigations of the paper show the impact of such factors as tank corrosion and other means on the variation of stress fields and deformation of the underground horizontal tank shell. The introduction of probabilistic methods allows for structural reliability assessment. While the computational time of the entire tank FEM model is high, the preliminary analysis is restricted to the structural part only. The analysis makes it possible to optimize the structure with regard to construction costs

  • Reliable computationally-efficient behavioral modeling of microwave passives using deep learning surrogates in confined domains
    • Sławomir Kozieł
    • Nurullah Calik
    • Peyman Mahouti
    • Mehmet Belen
    2023 IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES

    The importance of surrogate modeling techniques has been steadily growing over the recent years in high-frequency electronics, including microwave engineering. Fast metamodels are employed to speedup design processes, especially those conducted at the level of full-wave electromagnetic (EM) simulations. The surrogates enable massive system evaluations at nearly EM accuracy and negligible costs, which is invaluable in parameter tuning, multi-objective optimization, or uncertainty quantification. Nevertheless, modeling of electrical characteristics of microwave components is impeded by nonlinearity of their electrical characteristics, the need for covering broad parameter ranges, as well as dimensionality issues. Recently, a two-stage modeling approach has been proposed, which addresses some of these issues by constraining the surrogate model domain to only include high-quality designs, thereby reducing the cardinality of the dataset required to establish an accurate metamodel. In this paper, a novel technique is proposed, which combines the two-stage modeling concept with Multi-head Deep Regression Network (MHDRN) surrogates customized to handle responses of microwave passives over wide ranges of operating frequencies and geometry parameters. Using three microstrip circuits, a superior performance of the proposed modeling framework is demonstrated with respect to multiple state-of-the-art benchmark methods. In particular, the relative RMS error is shown to reach the level of less than three percent for the datasets consisting of just a few hundred samples.

  • Remediation of soils on municipal rendering plant territories using Miscanthus × giganteus
    • Anna Grzegórska
    • Natalia Czaplicka
    • Jacek Antonkiewicz
    • Piotr Rybarczyk
    • Agnieszka Baran
    • Krzysztof Dobrzyński
    • Dawid Zabrocki
    • Andrzej Rogala
    2023 Full text ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH

    Phytoremediation, as a cost-effective, highly efficient, environmentally friendly, and green approach, gained attention to the removal of metals, including heavy metals, from contaminated soils. The toxic nature of heavy metals can have an adverse effect on human health and the ecosystem, and their removal remains a worldwide problem. Therefore, in this study, a field experiment was carried out to evaluate the potential of Miscanthus × giganteus for the removal of ten microelements and heavy metals (Al, Zn, Fe, Pb, Cd, Co, Cr, Cu, Mn, Ni) from contaminated soil in the territory of a Municipal Waste Rendering Plant. Moreover, the effect of the incorporation of soil improver obtained upon composting biodegradable waste as well as the addition of highly contaminated post-industrial soil on the efficiency of phytoremediation and plant growth was described. The soil improver (SK-8) was applied to the soil at a rate of 200 Mg ha−1 and 400 Mg‧ha−1. Meanwhile, in the last object, 100 Mg‧ha−1 of highly contaminated post-industrial soil was added. Herein, the research was aimed at assessing the possibility of phytoextraction of heavy metals from soils with different physicochemical properties. The results showed that plants cultivated in soil with 400 Mg‧ha−1 of soil improver exhibited the highest yield (approximately 85% mass increase compared to the soil without additives). Furthermore, the application of a single dose of SK-8 (200 Mg ha−1) increased the uptake of Al, Fe, Co, Pb, Mn, Ni, and Cd by Miscanthus × giganteus compared to the soil without additives. Additionally, the performed biotests demonstrated no or low toxicity of the investigated soils affecting the test organisms. However, in all experiments, the phytorecovery of the elements did not exceed 1% of the amount introduced to the soil, which may result from a short cultivation period and large doses of SK-8 or highly contaminated post-industrial soil.

  • Removal of Arsenic from Wastewater Using Hydrochar Prepared from Red Macroalgae: Investigating Its Adsorption Efficiency and Mechanism
    • Aisha Khanzada
    • Muhammad Rizwan
    • Hussein Al-Hazmi
    • Joanna Majtacz
    • Tonni Agustiono Kurniawan
    • Jacek Makinia
    2023 Full text Water

    Arsenic (As) is a prominent carcinogen component produced via both geogenic and anthropogenic processes, posing serious risks to human health. This study aimed to investigate the potential of hydrochar prepared from red macroalgae for removing As from synthetic wastewater. The hydrochar was produced through 5 h hydrothermal carbonization (HTC) treatment at 200 °C, and then, chemically activated with ferric chloride hexahydrate (FeCl3·6H2O). SEM analysis revealed a permeable structure of hydrochar, while FTIR analysis detected the occurrence of several functional groups at the hydrochar interface. EDS analysis showed an increase in carbon concentration after FeCl3·6H2O activation. Hydrochar was then tested in batch experiments to investigate its As removal efficiency, with ICP-MS used to determine the levels of As after the adsorption process. The results showed that As removal efficiency increased with increasing initial As concentration from 50 to 250 mg/L, and the highest As removal efficiency was 84.75% at a pH of 6, initial concentration of 0.25 mg/L, and adsorbent dose of 1000 mg at 120 min. The Langmuir isotherm model supported the occurrence of homogeneous adsorption over the surface of hydrochar, while the pseudo-second-order model confirmed the chemisorptive nature of the process.

  • Removal of cyclohexane vapors from air in biotrickling filters: Effects of gas mixture composition and circular economy approach
    • Piotr Rybarczyk
    • Bartosz Szulczyński
    • Dominik Dobrzyniewski
    • Karolina Kucharska
    • Jacek Gębicki
    2023 Full text Chemical and Process Engineering : New Frontiers

    This work presents results of investigations on biotrickling filtration of air polluted with cyclohexane co-treated in binary, ternary and quaternary volatile organic compounds (VOCs) mixtures, including vapors of hexane, toluene and ethanol. The removal of cyclohexane from a gas mixture depends on the physicochemical properties of the co-treated VOCs and the lower the hydrophobicity of the VOC, the higher the removal efficiency of cyclohexane. In this work, the performance of biotrickling filters treating VOCs mixtures is discussed based on surface tension of trickling liquid for the first time. A mixed natural – synthetic packing for biotrickling filters was utilized, showing promising performance and limited maintenance requirements. Maximum elimination capacity of about 95 g/(m 3·h) of cyclohexane was reached for the total VOCs inlet loading of about 450 g/(m 3·h). This work presents also a novel approach of combining biological air treatment with management of a spent trickling liquid in the perspective of circular economy assumptions. The waste liquid phase was applied to the plant cultivation, showing a potential for e.g. enhanced production of energetic biomass or polluted soil phytoremediation.

  • Renovation works in buildings in the area of former defensive fortifications
    • Maciej Niedostatkiewicz
    • Tomasz Majewski
    • Adam Baryłka
    2023 Full text Inżynieria Bezpieczeństwa Obiektów Antropogenicznych

    he paperpresents the Complex of Buildings which was created in Gdańsk as a result of the reconstruction and development of the remains of the defensive fortifications of Redita Napoleońska. Some of the buildings of the Building Complex, after many years of operation, were in an emergency condition and required urgent renovation and repair work. The papercontains a detailed analysis of the technicalcondition of individual buildings of the Building Complex and analyzes the impact of the current use and the lack of regular periodic repairs on the technical efficiency of these facilities. Conceptual solutions in the field of renovation and repair workswere also presented, the purpose of which was to bring the objects in question to the proper technical condition.

  • Representativity of ISO test track surface based on controlled pass-by measurements
    • Truls Berge
    • Piotr Mioduszewski
    2023

    Within the Polish-Norwegian research project ELANORE, a limited Round Robin Test has been performed on four ISO tracks in Northern Europe. The basic objective of the project is to improve the EU directive on labelling of tyres for noise and rolling resistance. This directive is based on the measurement procedures proscribed in the UNECE Reg.117. Measurements on 3 ISO tracks were performed in 2021 and presented at InterNoise 2022. This paper adds results from tests conducted on a fourth ISO track as well as on trafficked roads with different conventional pavements: 2 in Norway (MA11 and SMA16) and 3 in Poland (SMA8, SMA11 and EACC). On all ISO test tracks and road test sites the same car, test tyres and test equipment as well as the same personnel were used to minimize the measurement uncertainties. Measurements were done using the controlled pass-by (CPB) method for vehicle test speeds between 40 and 90 km/h, with 2 test conditions: according to Reg.117 and with so-called "light test conditions". The main conclusion is that the noise ranking of the tyres on both, the ISO tracks and conventional pavements do not correspond to the ranking based on the label values given by tyre manufacturers.

  • Requirements for Residual Current Devices Intended for Electric Vehicle Charging Systems
    • Stanisław Czapp
    2023 Automatyka Elektryka Zakłócenia

    The properties of residual current devices have been presented from the point of view of their ability to detect a specific shape of the residual current waveform. Moreover, the standard requirements relating to residual current protection used in electric vehicle charging installations have been pointed out. The operating characteristics of the IC-CPD and RDC-DD protections, which are intended for charging electric vehicles in mode 2 and mode 3, respectively, have been also discussed.

  • RESEARCH ON HYDRODYNAMIC PEEK JOURNAL BEARINGS LUBRICATED WITH WATER AND OIL
    • Tomasz Żochowski
    • Artur Olszewski
    • Michał Wasilczuk
    2023 Full text TRIBOLOGIA

    The main purpose of the research was to determine the possibilities and experimentally test the benefits of replacing conventional oil lubrication with ecological water lubrication. Tests were carried out on a test rig for hydrodynamic radial bearings under conditions representative of the expected applications for the bearing in water turbines. Bearings made from the polymer material PEEK (polyether ether ketone) were tested under static loads. The tests were carried out for two types of lubrication: pure water and oil, with a viscosity of ISO VG 46. A comparison of friction coefficients and load-carrying capacity for both lubricants was made. During the tests, an interesting phenomenon of polymer material running in was observed for relatively high pressures when lubricated with a very low-viscosity lubricating medium, i.e., water (pressures in the bearing over 2 MPa).

  • Research on the effect of low-sulphur marine fuels on the dynamic characteristics of a CI engine
    • Zbigniew Korczewski
    2023 Full text Combustion Engines

    The implementation of low-sulphur, so-called modified marine fuels into operation requires prior labora- tory engine tests to assess the energy, emission and structural effects of their usage. This type of research are carried out on the test bed of a diesel engine as a small-scale physical model that reproduces the adequate design and process (parametric) features of a full-size marine engine. Their key stage is to determine the energy characteristics of the engine in the steady state of operation determined on the basis of the analysis of the developed indicator diagram and the dynamic characteristics of the transient processes from idling to the reference steady state of load – and vice versa. In this way, the basic diagnostic parameters of the fuel usable quality are determined: the rate of pressure increase in the cylinder and the average deceleration of the engine crankshaft within the strenuous transient process. This article presents representative results of this type of research carried out on six different, low-sulphur marine fuels used to feed marine engines.

  • Resonator-Loaded Waveguide Notch Filters with Broad Tuning Range and Additive-Manufacturing-Based Operating Frequency Adjustment Procedure
    • Tanveer Haq Ul
    • Hanna Koziel
    • Anna Pietrenko-Dąbrowska
    2023 Full text Electronics

    This article presents a new class of ring-resonator-loaded waveguide notch filters with a broad tuning range, low cost, and improved performance. The proposed approach employs a comple-mentary asymmetric split ring resonator coupled to a microstrip transmission line and excited in a rectangular waveguide. An equivalent circuit model is proposed to explain the working principle of the proposed notch filter. The adjustment of the operating frequency is based on additive man-ufacturing of a metallic copper patch allocated on the microstrip transmission line, which enables extensive tuning capabilities and consistent performance with minimum variations across the tuning window. For demonstration purposes, a filter employing a WR-28 waveguide and photo-lithography-manufactured resonator is prototyped and experimentally validated. The measured results indicate a broad 8-GHz tuning range with a consistent insertion loss, ranging from 23.4 to 31.4 GHz. An inverse regression model is constructed using measurement data obtained for tun-ing patches of various sizes, which allows for determining the relationships between the operating frequency and the copper patch size. The resulting calibration curve enables rapid filter tuning to the required frequency by inserting metallic patches of the model-predicted size.

  • Resource productivity and environmental degradation in EU-27 countries: context of material footprint
    • Muhammad Mushafiq
    • Błażej Prusak
    2023 Full text ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH

    This study explores the relationship between the resource productivity and environmental degradation in European Union-27 countries. This study tests this relationship in context of high, moderate, and low material footprint sub-samples; these samples are formed utilizing the expectation–maximization machine learning algorithm. Using the panel data set of EU-27 countries from 2000 to 2020, linear and non-linear autoregressive distributed lag (ARDL) are applied for the symmetric and asymmetric evidence and to test environmental Kuznets curve (EKC), linear ARDL with the quadratic function is included. Results of the symmetric relationship find evidence of resource productivity’s impact on the environmental degradation. In full sample of EU-27, both symmetric and asymmetric methods show that the short run and long run increase of resource productivity lower the environmental degradation. Only long run asymmetric relationship in high material footprint subsamples supports that the resource productivity controls environmental degradation. Results of moderate material footprint sub-sample are mixed. However, low material footprint countries show that resource productivity in long run controls the environmental degradation in symmetry and only positive resource controls productivity in short run in asymmetric relationship. The reason for mixed results is the quadratic nature of sub-samples. EKC hypothesis is validated in moderate and low material footprint sub-samples. This research has many policy implications.

  • Respiration rate estimation using non-linear observers in application to wastewater treatment plant
    • Mateusz Czyżniewski
    • Rafał Łangowski
    • Robert Piotrowski
    2023 JOURNAL OF PROCESS CONTROL

    A problem of respiration rate estimation using two new non-linear observers for a wastewater treatment plant is addressed in this paper. In particular, a non-linear adaptive Luenberger-like observer and a super twisting sliding mode observer have been derived to produce stable and bounded estimates of the respiration rate. During the synthesis of the particular observer, an appropriate mathematical utility model was used. The observability analysis of this model was performed using a method of indistinguishable state trajectories. The stability of the devised observers was proved using the Lyapunov stability theory. The performance of the developed observers was validated by simulation using ranges of data from the case study wastewater treatment plant. Satisfactory results have been obtained and they demonstrate high effectiveness of the devised observers.

  • Respiratory Rate Estimation Based on Detected Mask Area in Thermal Images
    • Natalia Kowalczyk
    • Jacek Rumiński
    2023

    The popularity of non-contact methods of measuring vital signs, particularly respiratory rate, has increased during the SARS-COV-2 pandemic. Breathing parameters can be estimated by analysis of temperature changes observed in thermal images of nostrils or mouth regions. However, wearing virus-protection face masks prevents direct detection of such face regions. In this work, we propose to use an automatic mask detection approach to select pixels within a mask region as a source of respiration information allowing efficient estimation of respiratory signals. We performed experiments with two important types of virus protection masks, i.e., FFP2 (N95) and surgical masks, for subjects while sitting, slowly walking from a short distance toward a camera, and slowly walking with moderate head movements. Experiments conducted with the adapted YOLO model have shown that detection of the mask area on the face allows for higher SNR values and reduces error in respiratory rate estimation in all analyzed scenarios. The Mean Absolute Error for respiratory rate estimation was below 1 bpm for sitting subjects for all types of masks. The error for walking subjects was 1.21 bpm for an FFP2 mask and about 2.1 bpm for a surgical mask. In the presence of head movements, while walking, the MAE was below 1.39 bpm and less than 1 bpm when only one outlier was removed.

  • Restrained differential of a graph
    • Abel Cabrera-Martinez
    • Magda Dettlaff
    • Magdalena Lemańska
    • Juan Alberto Rodriguez-Velazquez
    2023 Full text Discussiones Mathematicae Graph Theory

    Given a graph $G=(V(G), E(G))$ and a vertex $v\in V(G)$, the {open neighbourhood} of $v$ is defined to be $N(v)=\{u\in V(G) :\, uv\in E(G)\}$. The {external neighbourhood} of a set $S\subseteq V(G)$ is defined as $S_e=\left(\cup_{v\in S}N(v)\right)\setminus S$, while the \emph{restrained external neighbourhood} of $S$ is defined as $S_r=\{v\in S_e : N(v)\cap S_e\neq \varnothing\}$. The restrained differential of a graph $G$ is defined as $\partial_r(G)=\max \{|S_r|-|S|:\, S\subseteq V(G)\}.$ In this paper, we introduce the study of the restrained differential of a graph. We show that this novel parameter is perfectly integrated into the theory of domination in graphs. We prove a Gallai-type theorem which shows that the theory of restrained differentials can be applied to develop the theory of restrained Roman domination, and we also show that the problem of finding the restrained differential of a graph is NP-hard. The relationships between the restrained differential of a graph and other types of differentials are also studied. Finally, we obtain several bounds on the restrained differential of a graph and we discuss the tightness of these bounds.

  • Results of the “DPDT-Auger” Research Project on Screw Displacement Piles
    • Adam Krasiński
    • Andrzej Słabek
    • Paweł Więcławski
    • Mateusz Wiszniewski
    • Tomasz Kusio
    • Witold Tisler
    2023 Full text Architecture Civil Engineering Environment

    The main objective of the “DPDT-Auger” research project was to test the prototype DPDT auger for forming screw displacement piles in the ground (patented in Poland in 2020). An additional aim was to develop design methods and rules for the making of such piles. The augers and piles were first tested on a model scale, and then more extensively in the real scale on experimental field plots. The results found the overall functionality of the DPDT auger to be good, and in several aspects better than that of the SDP auger. The load-bearing capacities and Q-s characteristics of piles made with both augers were considered comparable. All the conducted tests and their derived dependencies together with the results of in situ subsoil tests allowed for the development of empirical calculation methods and prognostic procedures, useful for designing and producing piles with DPDT and SDP augers. FEM numerical simulation rules for the considered piles were also developed, verified and calibrated by the results of real pile tests. This article describes only the most important final results of the research project but not the detailed results of the numerous tests and analyses that were carried out. Also omitted are the results of model tests and numerical simulations, as well as the implementation and acceptance recommendations, as they have already been or will be the subject of separate publications.

  • Rethinking non-governmental organizations – at the crossroad of economics and civil society
    • Mikołaj Haczewski
    • Małgorzata Gawrycka
    2023 Full text Horyzonty Polityki

    The article aims to close the existing knowledge gaps, show why non‑governmental organizations are founded and maintained, and elaborate and systematize the existing knowledge through an analysis of the existing subdisciplines within economics, laying the groundwork for the economics of non‑governmental organizations. The article was written based on a structured literature review with an approach similar to the grounded theory method. The research question is: Why are NGOs founded and what is their modus operandi? After determining the research ques‑tion, literature evidence was collected from a variety of sources, which led to the creation of a theoretical explanatory model. Nevertheless, a deductive, top‑down approach has been taken to present the final model in a more comprehensible and transparent way. Based on the institutional hierarchy of O.E. Wil‑liamson and drawing from the theoretical framework of the economics of the public sector and the motives behind the sharing economy, a model was built that explains why NGOs are founded and maintained, thus elucidating the route from social theory (in particular, institutional environments) all the way to undertaking actions to solve a given issue. The article influences and enhances the current state of knowledge regarding non‑governmental institutions, including the placement of NGOs in particular disciplines within economics. It also significantly supports researchers doing subsequent studies regarding this area of social science. After further research in the proposed direction, more practical implications may arise in the future, including improvements in the management of NGOs that will facilitate their more efficient operation.

  • Reverberation divergence in VR applications
    • Patryk Rolkowski
    • Piotr Odya
    • Bartłomiej Mróz
    2023

    The aim of this project was to investigate the correlation between virtual reality (VR) imagery and ambisonic sound. With the increasing popularity of VR applications, understanding how sound is perceived in virtual environments is crucial for enhancing the immersiveness of the experience. By examining the relationship between visual scenes and sound scenes, this research attempts to explore how the interaction between vision and hearing influences the perception of the virtual environment. In the experiment, participants were immersed in a virtual environment that replicated a concert hall and were exposed to different types of sound scenes. Each sound scene differed in the employed impulse response recorded in real venues such as concert halls, auditoriums, churches, etc. To provide a realistic auditory experience, the sound scenes were processed using third-order ambisonics and decoded using binaural techniques with HRTF. The research was conducted using paired tests, where participants compared different sound scenes with each other, while viewing the same visual scene. One of the major conclusions drawn from the conducted research was the confirmation of the role of spatial sound in creating immersive VR experiences. The study demonstrated that the appropriate matching of spatial sound to the VR visual scene is an important factor for achieving full immersion. Additionally, the existence of expectations and preferences regarding the characteristics of reverberation in different types of spaces was discovered. These findings have significant implications for the design of virtual environments, and understanding these aspects can contribute to the improvement of VR technology and the creation of more immersive and realistic virtual experiences for users.

  • Reverse vaccinology-based prediction of a multi-epitope SARS-CoV-2 vaccine and its tailoring to new coronavirus variants
    • Wahiba Ezzemani
    • Anass Kettani
    • Subrahmanyam Sappati
    • Kavya Kondaka
    • Hicham El Ossmani
    • Kyoko Tsukiyama-Kohara
    • Haya Altawalah
    • Rachid Saile
    • Michinori Kohara
    • Soumaya Benjelloun
    • Sayeh Ezzikouri
    2023 JOURNAL OF BIOMOLECULAR STRUCTURE & DYNAMICS

    The genome feature of SARS-CoV-2 leads the virus to mutate and creates new variants of concern. Tackling viral mutations is also an important challenge for the development of a new vaccine. Accordingly, in the present study, we undertook to identify B- and T-cell epitopes with immunogenic potential for eliciting responses to SARS-CoV-2, using computational approaches and its tailoring to coronavirus variants. A total of 47 novel epitopes were identified as immunogenic triggering immune responses and no toxic after investigation with in silico tools. Furthermore, we found these peptide vaccine candidates showed a significant binding affinity for MHC I and MHC II alleles in molecular docking investigations. We consider them to be promising targets for developing peptide-based vaccines against SARS-CoV-2. Subsequently, we designed two efficient multi-epitopes vaccines against the SARS-CoV-2, the first one based on potent MHC class I and class II T-cell epitopes of S (FPNITNLCPF–NYNYLYRLFR–MFVFLVLLPLVSSQC), M (MWLSYFIASF–GLMWLSYFIASFRLF), E (LTALRLCAY–LLFLAFVVFLLVTLA), and N (SPRWYFYYL–AQFAPSASAFFGMSR). The second candidate is the result of the tailoring of the first designed vaccine according to three classes of SARS-CoV-2 variants. Molecular docking showed that the protein-protein binding interactions between the vaccines construct and TLR2–TLR4 immune receptors are stable complexes. These findings confirmed that the final multi-epitope vaccine could be easily adapted to new viral variants. Our study offers a shortlist of promising epitopes that can accelerate the development of an effective and safe vaccine against the virus and its adaptation to new variants.

  • Review and Indication of Key Activities for Energy Management Improvement in DC Microgrids
    • Kawsar Nassereddine
    • Marek Turzyński
    • Ryszard Strzelecki
    2023

    DC MicroGrids (MG) must have Energy Management Systems (EMS) to guarantee efficient, dependable, and environmentally friendly electricity. The application of Model Predictive Control (MPC), proved to be helpful due to its adaptability and capacity to use non-linear models. This paper, based on an extensive literature review, identifies and discusses the three key activities to improve the characteristics of DC microgrids, i.e.: the use of Energy Storage Systems (ESS), the implementation of Demand Side Management (DSM), and the use of MPC. These activities generally associated with the use of advanced control techniques allow optimization of microgrid operation taking into account various practical constraints, including time horizon, ESS parameters, and Demand Response program (DRP).

  • Review of Methods for Diagnosing the Degradation Process in Power Units Cooperating with Renewable Energy Sources Using Artificial Intelligence
    • Paweł Ziółkowski
    • Marta Drosińska-Komor
    • Jerzy Głuch
    • Łukasz Breńkacz
    2023 Full text ENERGIES

    This work is based on a literature review (191). It mainly refers to two diagnostic methods based on artificial intelligence. This review presents new possibilities for using genetic algorithms (GAs) for diagnostic purposes in power plants transitioning to cooperation with renewable energy sources (RESs). The genetic method is rarely used directly in the modeling of thermal-flow analysis. However, this assignment proves that the method can be successfully used for diagnostic purposes. The GA method was presented in this work for thermal-flow studies of steam turbines controlled from the central power system to obtain the stability of RESs. It should be remembered that the development of software using genetic algorithms to locate one-off degradations is necessary for a turbine that works sustainably with RESs. In this paper, against the background of the review, diagnostic procedures create an inverse model of a thermal power plant. Algorithms were used to detect fast global extremes through the convergence of simulated signatures with signs explaining degradation. In addition, statistical dependencies are used in the selection phase to accelerate fault detection. The created procedure allows obtaining a diagnosis in the form of a single degradation. This procedure turns out to be quite effective for the above example.

  • Review of Shoreline Extraction Methods from Aerial Laser Scanning
    • Andrzej Stateczny
    • Armin Halicki
    • Mariusz Specht
    • Cezary Specht
    • Oktawia Lewicka
    2023 Full text SENSORS

    Autonomous technologies are increasingly used in various areas of science. The use of unmanned vehicles for hydrographic surveys in shallow coastal areas requires accurate estimation of shoreline position. This is a nontrivial task, which can be performed using a wide range of sensors and methods. The aim of the publication is to review shoreline extraction methods based solely on data from aerial laser scanning (ALS). This narrative review discusses and critically analyses seven publications drawn up in the last ten years. The discussed papers employed nine different shoreline extraction methods based on aerial light detection and ranging (LiDAR) data. It should be noted that unambiguous evaluation of shoreline extraction methods is difficult or impossible. This is because not all of the methods reported achieved accuracy, the methods were assessed on different datasets, the measurements were conducted using different devices, the water areas differed in geometrical and optical properties, the shorelines had different geometries, and the extent of anthropogenic transformation. The methods proposed by the authors were compared with a wide range of reference methods.

  • Review on friction stir welding of dissimilar magnesium and aluminum alloys: Scientometric analysis and strategies for achieving high-quality joints
    • Mohamed M. Z. Ahmed
    • Mohamed M. El-Sayed Seleman
    • Dariusz Fydrych
    • Gürel Çam
    2023 Full text Journal of Magnesium and Alloys

    Magnesium and aluminum alloys continually attract interest as lightweight structural materials for transport applications. However, joining these dissimilar alloys is very challenging. The main obstacle that hinders progress in dissimilar Mg-Al joining is the formation of brittle intermetallic compounds (IMCs). As a solid-state joining technique, FSW is an excellent candidate to attenuate the deleterious IMC effects in dissimilar Al-Mg joining due to the inherent low heat inputs involved in the process. However, the IMCs, namely Al3Mg2 and Al12Mg17 phases, have also been reported to form during Al-Mg dissimilar FSW; their amount and thickness depend on the heat input involved; thus, the weld parameters used. Since the heat dissipated in the material during the welding process significantly affects the amount of IMCs, the heat input during FSW should be kept as low as possible to control and reduce the amount of IMCs. This review aims to critically discuss and evaluate the studies conducted in the dissimilar Al/Mg FSW through a scientometric analysis and also with a focus on the strategies recently applied to enhance joint quality. The scientometric analysis showed that the main research directions in Mg/Al FSW are the technological weldability of aluminum and magnesium during FSW, structural morphology, and mechanical properties of dissimilar welded joints. Considering the scope of application of the aforementioned joints, the low share of articles dealing with environmental degradation and operational cracking is surprising. This might be attributed to the need for well-developed strategies for obtaining high-quality and sustainable joints for applications. Thus, the second part of this review is conventional, focusing mainly on the new strategies for obtaining high-quality Mg/Al joints. It can be concluded that in addition to the necessity to optimum welding parameters to suppress the excessive heat to limit the amount and thickness of IMC formed and improve the overall joint quality, strategies such as using Zn interlayer, electric current assisted FSW(EAFSW), ultrasonic vibration FSW (UVaFSW), are considered effective in the elimination, reduction, and fragmentation of the brittle IMCs.

  • Revisiting Toroidal Dipolar Moment in Planar Metamaterial
    • Abhishek Kumar Jha
    • Adam Lamęcki
    • Michał Mrozowski
    2023 IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES

    This article revisits the electric, magnetic, and toroidal dipolar moments in the metamaterial structure and presents the flatland design for generating a toroidal dipolar response for the electromagnetic plane wave at normal incidence. Based on the numerical analysis of the surface current, the electric field, the magnetic field, and the quantitative analysis of scattered power supported by the electromagnetic multipole theory, it is shown that the earlier design involving symmetric unit cells is not able to produce toroidal dipolar moment. This study resulted in a new design of a planar metasurface, which provides a toroidal response as the dominant mode when excited by the transverse magnetic (TM)-polarized electromagnetic wave. The scattered power calculated for the proposed toroidal flatland metamaterial is found to be 1.7 × 105 times larger than the earlier design under investigation. The scattered power due to the toroidal dipole in the proposed design is found to be at least 70 times and 8 × 108 times larger than the electric dipole and the magnetic dipole, respectively, in the z-direction.

  • Revitalizing the Sacral Complex of the Parish of the Sacred Heart of Jesus in Gdynia: A Comprehensive Restoration Project in Alignment with Monument Conservator's Guidelines and Technical Prerequisites
    • Maciej Niedostatkiewicz
    • Jacek Bramorski
    2023 Full text Modern Engineering

    Religiouscomplexes, due to their monumental character, belong to the group of facilities in which carrying out renovation works is difficult. Very often, construction works carried out as part of planned renovation work include not only modernization but also repair works, includingthose related to the reinforcement of structural elements. Renovation work in sacral buildings is particularly difficult when they are located in the area covered by conservation.The paperis a case study of the existing religious complex of the Parish of the Sacred Heart of Jesus located in Gdynia, consisting of a church building and a bell tower. The church building realized in the 1960s and the belfry located in its immediate vicinity built in the 1980s after many years of use showednot only signs of operational decapitalization which lowered their aesthetic value as a monument containing elements of modernist architecture, but also all were characterized by damage to construction and finishing elements, which posed a threat to the safety of the structure and use.

  • RF Multi-Functional Input-Reflectionless Dispersive-Delay Structure With Sharp-Rejection Filtering Using Channelization Techniques
    • Maciej Jasiński
    • Li Yang
    • Adam Lamęcki
    • Roberto Gomez-Garcia
    • Michał Mrozowski
    2023 Full text IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS

    A class of RF multi-functional input-reflectionless dispersive-delay structure (DDS) with linear-type in-band groupdelay variation and sharp-rejection bandpass-filtering capability is reported. It exploits a two-branch-channelized/balanced-type circuit with similar low-order reflective DDS units inside its channels, which are connected through input/output 3-dB quadrature wideband couplers. The adopted DDS unit is based on a coupledresonator network with a frequency-dependent cross-coupling. It introduces a pair of complex transmission zeros (TZs) to shape the intended in-band group-delay profile. Unequal transmissionline-based phase-shifting sections are also inserted at the outputs of both channels. In this manner, an input-absorptive behavior and selectivity enhancement with TZ generation are attained by means of transversal signal-interference techniques at the overall input and output nodes, respectively. Moreover, as the transferfunction phase term of the interference action in transmission is linear with frequency, the total group-delay pattern is defined by the DDS unit of the channels. As practical validation, a 1.5-GHz proof-of-concept microstrip prototype is constructed and tested.

  • Road traffic can be predicted by machine learning equally effectively as by complex microscopic model
    • Andrzej Sroczyński
    • Andrzej Czyżewski
    2023 Full text Scientific Reports

    Since high-quality real data acquired from selected road sections are not always available, a traffic control solution can use data from software traffic simulators working offline. The results show that in contrast to microscopic traffic simulation, the algorithms employing neural networks can work in real-time, so they can be used, among others, to determine the speed displayed on variable message road signs. This paper describes an experiment to develop and test machine learning models, i.e., long short-term memory, gated recurrent unit recurrent networks, and stacked autoencoder networks. It compares their effectiveness with traffic prediction results generated using a widely recognized traffic simulator that analyzes traffic at the level of individual vehicles.

  • Role of Fungi in Biodegradation of Imidazolium Ionic Liquids by Activated Sewage Sludge
    • Joanna Klein
    • Justyna Łuczak
    • Anna Brillowska-Dąbrowska
    2023 MOLECULES

    Ionic liquids (ILs), due to their specific properties, can play the role of persistent water contaminants. Fungi manifest the ability to decompose hardy degradable compounds, showing potential in the biodegradation of ILs, which has been studied extensively on sewage sludge; however, attention was drawn mainly to bacterial and not fungal species. The aim of the research was to determine the significance of fungi in ILs’ biodegradation to extend the knowledge and possibly point out ways of increasing their role in this process. The research included: the isolation and genetic identification of fungal strains potentially capable of [OMIM][Cl], [BMIM][Cl], [OMIM][Tf2N], and [BMIM][Tf2N] degradation, adjustment of the ILs concentration for biodegradability test by MICs determination and choosing strains with the highest biological robustness; inoculum adaptation tests, and finally primary biodegradation by OECD 301F test. The study, conducted for 2 mM [OMIM][Cl] as a tested substance and consortium of microorganisms as inoculum, resulted in an average 64.93% biodegradation rate within a 28-day testing period. For the individual fungal strain (Candida tropicalis), the maximum of only 4.89% biodegradation rate was reached in 10 days, then inhibited. Insight into the role of fungi in the biodegradation of ILs was obtained, enabling the creation of a complex overview of ILs toxicity and the possibilities of its biological use. However, only an inoculum consisting of a consortium of microorganisms enriched with a selected strain of fungi was able to decompose the IL, in contrast to that consisting only of an individual fungal strain.

  • ROLE OF GREEN LOGISTICS IN THE CONSTRUCTION OF SUSTAINABLE SUPPLY CHAINS
    • Nguyen Dang Khoa Pham
    • Gia Huy Dinh
    • Hoang T. Pham
    • Janusz Kozak
    • Phuong Nguyen Hoang
    2023 Full text Polish Maritime Research

    The global supply chain has been growing strongly in recent years. This development brings many benefits to the economy, society, and human resources in each country but also causes a large number of concerns related to the environment since traditional logistics activities in the supply chain have been releasing significant amount of emissions. For that reason, many solutions have been proposed to deal with these environmental pollution problems. Among these, three promising solutions are expected to completely solve environmental problems in every supply chain: (i) application of blockchain in the supply chain, (ii) Use of renewable energy and alternative fuels, and (iii) Design of a closed supply chain. However, it seems to lack comprehensive study of these solutions aiming to overcome the drawbacks of traditional logistics. Indeed, this work focuses on analyzing and evaluating the three above-mentioned solutions and the impacts of each solution on solving problems related to traditional logistics. More importantly, this work also identifies critical factors and challenges such as policies, laws, awareness, and risks that are found to be remarkable difficulties in the shifting progress of traditional logistics to green logistics. Finally, directions for developing and deploying green solutions to the logistics, supply chain, and shipping sectors toward decarbonization strategies and net-zero goals are discussed in detail.

  • Role of research and development in internationalization of high-tech firms: Empirical results from Poland
    • Krzysztof Wach
    • Nelly Daszkiewicz
    2023 Full text Journal of International Studies

    The article focuses on the significance of research and development (R&D) in driving the internationalization of Polish high-tech firms. R&D is essential for businesses to remain competitive and adapt their products to the specific requirements of different markets. The study aims to investigate the relationship between R&D and the internationalization process of high-tech firms based in Poland, with a focus on the innovation context. We used a quantitative research method and employed a survey questionnaire to evaluate the internationalization of high-tech firms in Poland. The study employed a computer-assisted telephone interviewing (CATI) method and identified the random sample of 263 fully-filled questionnaires during the survey that were important for further statistical analysis. We confirmed that research and development as it is commonly understood, i.e., having one's own R&D department and making expenditures on R&D, helps and strengthens the internationalization of high-tech firms.

  • Rotor-Flux Vector based Observer of Interior Permanent Synchronous Machine
    • Marcin Morawiec
    • Arkadiusz Lewicki
    • Charles Ikechukwu Odeh
    2023 Full text IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS

    The sensorless control system of the interior permanent magnet machine is considered in this paper. The control system is based on classical linear controllers. In the machine, there occurs non-sinusoidal distribution of rotor flux together with the slot harmonics, which are treated as the control system disturbances. In this case, the classical observer structure in the (d-q) is unstable for the low range of rotor speed resulting in disturbances. This negative effect can be minimized by using the observer structure which is based on the rotor flux vector in (α-β) stationary frame together with the classical rotor speed and position law of estimation. The performance of the observer structure is validated by simulation and experimental results in the sensorless control system with field-oriented control

  • Roughness evaluation of turned composite surfaces by analysis of the shape of Autocorrelation Function
    • Przemysław Podulka
    • Wojciech Macek
    • Beata Zima
    • Grzegorz Lesiuk
    • Ricardo Branco
    • Grzegorz Królczyk
    2023 Full text MEASUREMENT

    In this paper, the application of an Autocorrelation Function for the characterisation of surface topography was validated. The roughness evaluation of turned composite surfaces was supported by sophisticated studies of the Autocorrelation Function properties, considering especially the shape of the function. Details were measured with the optical method. The selection of the surface roughness evaluation procedures was carried out based on the Autocorrelation Function for both profile and areal analyses. Moreover, the application of various types of regular analysis methods, proposed in commercial software, like regular Gaussian regression and robust Gaussian functions, median de-noising, regular isotropic Spline, and fast Fourier transform filters, was proposed for the evaluation of surface topography parameters from the ISO 25178 standards. It was found that many common techniques, like commonly used filters, spectral analysis, and characterisation of texture direction, were supported by the proposed Autocorrelation Function studies. Moreover, the hard thresholding technique was found to be valuable in the comprehensive noise-suppression analysis.

  • Routing Method for Interplanetary Satellite Communication in IoT Networks Based on IPv6
    • Paweł Dobrowolski
    • Grzegorz Debita
    • Przemysław Falkowski-Gilski
    2023

    The matter of interplanetary network (IPN) connection is a complex and sophisticated topic. Space missions are aimed inter alia at studying the outer planets of our solar system. Data transmission itself, as well as receiving data from satellites located on the borders of the solar system, was only possible thanks to the use of powerful deep space network (DSN) receivers, located in various places on the surface of the Earth. In this paper, we describe a routing method, based on geostationary orbits of the planets of our solar system, to give predictable, orderly motion of the satellites, equipped with measurement tools, i.e., managed by repro-grammable field-programmable gate arrays (FPGAs), related with the Internet of things (IoT) concept.