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Gdańsk University of Technology

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  • Nauka w świecie cyfrowym okiem młodego inżyniera - jakość życia a jakość powietrza w miastach
    • Bartosz Pingot
    • Przemysław Falkowski-Gilski
    2022 Pismo PG

    Obecne w powietrzu zanieczyszczenia biorą udział w procesach zmian klimatycznych, a także bezpośrednio wpływają na ludzkie zdrowie, przejawiając toksyczność w wyższych stężeniach oraz zwiększając ryzyko występowania szerokiej gamy chorób. Jest to szczególnie niebezpieczne dla mieszkańców dużych miast oraz tych znajdujących się w grupach ryzyka. Dlatego też bardzo ważna pozostaje kwestia monitorowania stanu zanieczyszczenia powietrza w miastach.

  • Nauka w świecie cyfrowym okiem młodego inżyniera - początki techniki wirtualnej rzeczywistości
    • Karol Fidurski
    • Przemysław Falkowski-Gilski
    2022 Pismo PG

    Istnieje wiele definicji wirtualnej rzeczywistości (VR – Virtual Reality), które mniej lub bardziej pokrywają się ze sobą w różnych obszarach naukowych. Obecnie, gdy używamy określenia „VR”, odnosi się ono konkretnie do obrazów generowanych komputerowo, które zostały specjalnie zaprojektowane tak, aby dostarczyć jak najbardziej immersyjnych wrażeń. Sporo opracowań mówi również, że VR musi być interaktywna. To odróżniałoby ją od takich rozwiązań jak filmy 3D, wideo 360 itp.

  • Negative Poisson’s ratio from pentagons: A new auxetic structure combining three different auxetic mechanisms
    • Szymon Winczewski
    • Jarosław Rybicki
    2022 COMPUTATIONAL MATERIALS SCIENCE

    A novel class of two-dimensional auxetic structures based on the pentagon motif is proposed. Their mechanical properties are investigated by combining molecular mechanics simulations with a simple three-parameter mechanical model which assumes perfectly elastic behavior. It is predicted that the proposed structures – termed as double re-entrant honeycomb – may possess unique mechanical characteristics, which include complete and perfect auxeticity, as well as the negative Poisson’s ratio observed in both the tensile and compressive regimes. The behavior of the considered structures is explained in relation to well-known auxetic models. It is shown that the considered structures simultaneously implement three different mechanisms leading to a negative Poisson’s ratio: the opening of the re-entrant units, the rotation of the squares, and the flattening effect.

  • Negative result about the construction of genuinely entangled subspaces from unextendible product bases
    • Maciej Demianowicz
    2022 Full text PHYSICAL REVIEW A

    Unextendible product bases (UPBs) provide a versatile tool with various applications across different areas of quantum information theory. Their comprehensive characterization is thus of great importance and has been a subject of vital interest for over two decades now. An open question asks about the existence of UPBs, which are genuinely unextendible, i.e., they are not extendible even with biproduct vectors. In other words, the problem is to verify whether there exist genuinely entangled subspaces (GESs), subspaces composed solely of genuinely multiparty entangled states, complementary to UPBs. We solve this problem in the negative for many sizes of UPBs in different multipartite scenarios. In particular, in the all-important case of equal local dimensions, we show that there are always forbidden cardinalities for such UPBs, including the minimal ones corresponding to GESs of the maximal dimensions.

  • Neural Approximators for Variable-Order Fractional Calculus Operators (VO-FC)
    • Bartosz Puchalski
    2022 Full text IEEE Access

    The paper presents research on the approximation of variable-order fractional operators by recurrent neural networks. The research focuses on two basic variable-order fractional operators, i.e., integrator and differentiator. The study includes variations of the order of each fractional operator. The recurrent neural network architecture based on GRU (Gated Recurrent Unit) cells functioned as a neural approximation for selected fractional operators. The paper investigates the impact of the number of neurons in the hidden layer, treated as a hyperparameter, on the quality of modeling error. Training of the established recurrent neural network was performed on synthetic data sets. Data for training was prepared based on the modified Grünwald-Letnikow definition of variable-order fractional operators suitable for numerical computing without memory effects. The research presented in this paper showed that recurrent network architecture based on GRU-type cells can satisfactorily approximate targeted simple yet functional variable-order fractional operators with minor modeling errors. The presented solution is a novel approach to the approximation of VO-FC operators. It has the advantage of automatic selection of neural approximator parameters by optimization based on data customized for specific requirements.

  • Neural modelling of dynamic systems with time delays based on an adjusted NEAT algorithm
    • Krzysztof Laddach
    • Rafał Łangowski
    2022

    A problem related to the development of an algorithm designed to find an architecture of artificial neural network used for black-box modelling of dynamic systems with time delays has been addressed in this paper. The proposed algorithm is based on a well-known NeuroEvolution of Augmenting Topologies (NEAT) algorithm. The NEAT algorithm has been adjusted by allowing additional connections within an artificial neural network and developing original specialised evolutionary operators. This resulted in a compromise between the size of neural network and its accuracy in capturing the response of the mathematical model under which it has been learnt. The research involved an extended validation study based on data generated from a mathematical model of an exemplary system as well as the fast processes occurring in a pressurised water nuclear reactor. The obtaining simulation results demonstrate the high effectiveness of the devised neural (black-box) models of dynamic systems with time delays.

  • Neural network training with limited precision and asymmetric exponent
    • Marek Blok
    • Mariusz Pietrołaj
    2022 Full text Journal of Big Data

    Along with an extremely increasing number of mobile devices, sensors and other smart utilities, an unprecedented growth of data can be observed in today’s world. In order to address multiple challenges facing the big data domain, machine learning techniques are often leveraged for data analysis, filtering and classification. Wide usage of artificial intelligence with large amounts of data creates growing demand not only for storage and operational memory, but also computational power. Increasing complexity and variety of neural network architectures are vivid examples of such trends in the modern data-driven industry. In response to this situation, focusing on less demanding operations for inference and training of neural networks became a popular approach among many researchers to overcome resources related issues. This work aims to investigate one of the paths associated with the mentioned efficiency problems and shows the impact of floating-point precision limitation on convolutional neural networks, including experiments on various exponent and mantissa sizes. Additionally, authors explore floating-point numbers utilization and optimization techniques in the scope of neural network training. Based on conducted research a novel method of asymmetric exponent utilization is presented achieving almost identical accuracy of 32-bit floating-point parameters while training a neural network with only 12-bit variables without additional rounding.

  • Neural Network-Based Sequential Global Sensitivity Analysis Algorithm
    • Yen-Chen Liu
    • Leifur Leifsson
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    2022

    Performing global sensitivity analysis (GSA) can be challenging due to the combined effect of the high computational cost, but it is also essential for engineering decision making. To reduce this cost, surrogate modeling such as neural networks (NNs) are used to replace the expensive simulation model in the GSA process, which introduces the additional challenge of finding the minimum number of training data samples required to train the NNs accurately. In this work, a recently proposed NN-based GSA algorithm to accurately quantify the sensitivities is improved. The algorithm iterates over the number of samples required to train the NNs and terminates using an outer-loop sensitivity convergence criteria. The iterative surrogate-based GSA yields converged values for the Sobol’ indices and, at the same time, alleviates the specification of arbitrary accuracy metrics for the NN-based approximation model. In this paper, the algorithm is improved by enhanced NN modeling, which lead to an overall acceleration of the GSA process. The improved algorithm is tested numerically on problems involving an analytical function with three input parameters, and a simulation-based nondestructive evaluation problem with three input parameters.

  • Neural networks and deep learning
    • A. Pastor López-Monroy
    • Jesus Garcia Salinas
    2022

    In this chapter we will provide the general and fundamental background related to Neural Networks and Deep Learning techniques. Specifically, we divide the fundamentals of deep learning in three parts, the first one introduces Deep Feed Forward Networks and the main training algorithms in the context of optimization. The second part covers Convolutional Neural Networks (CNN) and discusses their main advantages and shortcomings for different scenarios and variants of CNNs. Finally, the third part presents Neural Networks for sequence modeling, in particular Recurrent Neural Networks (RNN), Gated Recurrent Units (GRU), Long Short-Term Memory (LSTM) and Attention Mechanisms. The description of the latter models are made in the context of different applications that allows to explain in a better way the details of each particular kind of neural network.

  • Neuroeconomy and Neuromarketing: The Study of the Consumer Behaviour in the COVID-19 Context
    • Juan Jose Blazquez-Resino
    • Santiago Gutierrez-Broncano
    • Edyta Gołąb-Andrzejak
    2022 Full text Frontiers in Psychology

    To address the study of consumer behavior in the post-COVID-19 era, the present Research Topic brings together a set of papers that attempt to study how different factors triggered by the pandemic have achieved a significant effect on consumers' behavioral intentions. These papers examine different subtopics related to food, health products, collaborative economy and, of course, neuroscience. Globally, the objectives of this special issue try to broadly reach the different perspectives in the study of consumer behavior in the context of COVID-19, considering: - A study of the effects of COVID-19 on consumer behavior in the short term. - An analysis of the economic effects of COVID-19. - The social and psychological changes brought about by the current situation of social change. - A study of consumer behavior from the perspective of neuromarketing and/or neuroeconomics. - Forecasting of changes in habits and behaviors caused by COVID-19. - The development of new marketing and distribution systems aimed at meeting new market needs. - New retailing techniques adapted to consumer changes.

  • Neuroobrazowanie u pacjentów uzależnionych od substancji psychoaktywnych
    • Klaudia Malisz
    2022 INŻYNIER I FIZYK MEDYCZNY

    Celem artykułu jest przedstawienie charakterystycznych zmian w obrębie mózgowia wynikających z zażywania substancji psychoaktywnych, możliwych do zaobserwowania za pomocą badań obrazowych.

  • Neutral Dissociation of Pyridine Evoked by Irradiation of Ionized Atomic and Molecular Hydrogen Beams
    • Tomasz Wąsowicz
    2022 Full text INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    The interactions of ions with molecules and the determination of their dissociation patterns are challenging endeavors of fundamental importance for theoretical and experimental science. In particular, the investigations on bond-breaking and new bond-forming processes triggered by the ionic impact may shed light on the stellar wind interaction with interstellar media, ionic beam irradiations of the living cells, ion-track nanotechnology, radiation hardness analysis of materials, and focused ion beam etching, deposition, and lithography. Due to its vital role in the natural environment, the pyridine molecule has become the subject of both basic and applied research in recent years. Therefore, dissociation of the gas phase pyridine (C5H5N) into neutral excited atomic and molecular fragments following protons (H+) and dihydrogen cations (H2+) impact has been investigated experimentally in the 5–1000 eV energy range. The collision-induced emission spectroscopy has been exploited to detect luminescence in the wavelength range from 190 to 520 nm at the different kinetic energies of both cations. High-resolution optical fragmentation spectra reveal emission bands due to the CH(A2Δ→X2Πr; B2Σ+→X2Πr; C2Σ+→X2Πr) and CN(B2Σ+→X2Σ+) transitions as well as atomic H and C lines. Their spectral line shapes and qualitative band intensities are examined in detail. The analysis shows that the H2+ irradiation enhances pyridine ring fragmentation and creates various fragments more pronounced than H+ cations. The plausible collisional processes and fragmentation pathways leading to the identified products are discussed and compared with the latest results obtained in cation-induced fragmentation of pyridine.

  • New 2-[(4-Amino-6-N-substituted-1,3,5-triazin-2-yl)methylthio]-N-(imidazolidin-2-ylidene)-4-chloro-5-methylbenzenesulfonamide Derivatives, Design, Synthesis and Anticancer Evaluation
    • Łukasz Tomorowicz
    • Beata Żołnowska
    • Krzysztof Szafrański
    • Jarosław Chojnacki
    • Ryszard Konopiński
    • Ewa A. Grzybowska
    • Jarosław Sławiński
    • Anna Kawiak
    2022 Full text INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    In the search for new compounds with antitumor activity, new potential anticancer agents were designed as molecular hybrids containing the structures of a triazine ring and a sulfonamide fragment. Applying the synthesis in solution, a base of new sulfonamide derivatives 20–162 was obtained by the reaction of the corresponding esters 11–19 with appropriate biguanide hydrochlorides. The structures of the compounds were confirmed by spectroscopy (IR, NMR), mass spectrometry (HRMS or MALDI-TOF/TOF), elemental analysis (C,H,N) and X-ray crystallography. The cytotoxic activity of the obtained compounds toward three tumor cell lines, HCT-116, MCF-7 and HeLa, was examined. The results showed that some of the most active compounds belonged to the R1 = 4-trifluoromethylbenzyl and R1 = 3,5-bis(trifluoromethyl)benzyl series and exhibited IC50 values ranging from 3.6 μM to 11.0 μM. The SAR relationships were described, indicating the key role of the R2 = 4-phenylpiperazin-1-yl substituent for the cytotoxic activity against the HCT-116 and MCF- 7 lines. The studies regarding the mechanism of action of the active compounds included the assessment of the inhibition of MDM2-p53 interactions, cell cycle analysis and apoptosis induction examination. The results indicated that the studied compounds did not inhibit MDM2-p53 interactions but induced G0/G1 and G2/M cell cycle arrest in a p53-independent manner. Furthermore, the active compounds induced apoptosis in cells harboring wild-type and mutant p53. The compound design was conducted step by step and assisted by QSAR models that correlated the activity of the compounds against the HCT-116 cell line with molecular descriptors.

  • New approach for the synthesis of Ag3PO4-graphene photocatalysts
    • Łukasz Lewandowski
    • Julia Zwara-Sidorko
    • Anna Gołąbiewska
    • Tomasz Klimczuk
    • Grzegorz Trykowski
    • Adriana Zaleska-Medynska
    2022 Full text MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING

    A facile and effective plasma sputtering method for the preparation of a visible light active photocatalyst - rhombic dodecahedral silver phosphate Ag3PO4 covered with nanographene (Ag3PO4-GR) with improved stability has been developed. Proposed method allows for the usage of readily available materials for nanographene sputtering and for easy scaling-up. The stability improvement, confirmed by visible light-induced phenol degradation experiment, could be attributed to the synergistic effect of the silver phosphate particles and graphene material allowing for migration of metallic silver nanoparticles from semiconductor’s surface to graphene body keeping the semiconductors surface “silver free”. Also due to its conductive properties, nanographene may additionally be preventing electron-hole recombination and metallic silver formation.

  • New Architecture of Solid-State High-Voltage Pulse Generators
    • Yahia Achour
    • Jacek Starzyński
    • Kazimierz Jakubiuk
    2022 Full text ENERGIES

    The application of the nanosecond pulsed electric field (nsPEF) for biomedical treatments has gained more interest in recent decades due to the development of pulsed power technologies which provides the ability to control the electric field dose applied during tests. In this context, the proposed paper describes a new architecture of solid-state high-voltage pulse generators (SSHVPG) designed to generate fully customised sequences of quasi-rectangular pulses. The idea is based on the combination of semiconductor switches (IGBT/MOSFET) known for their flexibility and controllability with special magnetic switches to build compact and modular generators. The proposed structure is inspired by the most known pulse generator of Marx, but mixes its two variants for negative and positive polarities. Thus, the polarity of the generated pulses can be freely selected. In addition to that, the use of IGBTs/MOSFET ensures a tunable repetition rate and pulse width. The capacitors are charged via a series of magnetic switches and a flyback DC–DC converter which provides fast and efficient charging and also an adjustable amplitude of the output pulses. The design can be easily simplified giving two other modified structures, based on the same idea, for mono-polar operating (only positive or only negative pulses) with a reduced number of switches. A SPICE simulation of the generator and results of experimental tests carried out on a three stages generator are presented. The obtained results confirm the operating principle and the claimed performances of the new structure.

  • New insights into modeling two-step nitrification in activated sludge systems – The effects of initial biomass concentrations, comammox and heterotrophic activities
    • Mohamad-Javad Mehrani
    • Dominika Sobotka
    • Przemysław Kowal
    • Jianhua Guo
    • Jacek Mąkinia
    2022 Full text SCIENCE OF THE TOTAL ENVIRONMENT

    In this study, the conventional two-step nitrification model was extended with complete ammonia oxidation (comammox) and heterotrophic denitrification on soluble microbial products. The data for model calibration/validation were collected at four long-term washout experiments when the solid retention time (SRT) and hydraulic retention time (HRT) were progressively reduced from 4 d to 1 d, with mixed liquor suspended solids (MLSS) of approximately 2000 mg/L at the start of each trial. A new calibration protocol was proposed by including a systematic calculation of the initial biomass concentrations and microbial relationships as the calibration targets. Moreover, the impact assessment of initial biomass concentrations (X) and maximum growth rates (µ) for ammonia-oxidizing bacteria (AOB), nitrite-oxidizing bacteria (NOB), comammox Nitrospira, and heterotrophs on the calibration accuracy were investigated using the response surface methodology (RSM). The RSM results revealed the strongest interaction of XAOB and µAOB on the model calibration accuracy. All the examined model efficiency measures confirmed that the extended model was accurately calibrated and validated. The estimated µ values were as follows: µAOB = 0.38±0.005 d-1, µNOB = 0.20±0.01 d-1, µCMX = 0.20±0.01 d-1, µHET = 1.0±0.03 d-1. For comparison, when using the conventional model, µAOB and µNOB increased respectively by 26 and 15% (µAOB = 0.48±0.02 d-1 and µNOB = 0.23±0.005 d-1). This study provides better understanding of the effects of the initial biomass composition and the accompanying processes (comammox and heterotrophic denitrification) on modeling two-step nitrification.

  • New insights of nanomaterials usage toward superhydrophobic membranes for water desalination via membrane distillation: A review
    • Emilia Gontarek-Castro
    • Roberto Castro-Muñoz
    • Marek Lieder
    2022 Full text CRITICAL REVIEWS IN ENVIRONMENTAL SCIENCE AND TECHNOLOGY

    Membrane distillation (MD) is a promising technology for seawater desalination due to the ability to process high-salinity waters and the ability to be driven by low-grade or waste heat. However, practical applications of MD membranes are limited by the low vapor flux and fouling problem. Recently, there is a growing interest in developing novel MD membrane materials with enhanced hydrophobicity to improve the efficiency of desalination performance. Interestingly, the incorporation of nanomaterials for tailoring superhydrophobic properties of MD membranes has attracted enormous attention in MD. Herein, according to the new insights of the available literature data, the current trend for achieving superhydrophobic MD membranes by embedding inorganic nanomaterials is provided. The influence of the inorganic additives on membrane fouling, stability, separation performance, is also discussed. Finally, theoretical principles of MD, the milestones of the evolution of developing superhydrophobic membrane surfaces, and future trends are also given for the new readers in the field.

  • New nanoadsorbent based on magnetic iron oxide containing 1,4,7,10-tetraazacyclododecane in outer chain (Fe3O4@SiO2-cyclen) for adsorption and removal of selected heavy metal ions Cd2+, Pb2+, Cu2+
    • Amanda Kulpa-Koterwa
    • Jacek Ryl
    • Karolina Górnicka
    • Paweł Niedziałkowski
    2022 Full text JOURNAL OF MOLECULAR LIQUIDS

    Magnetic Fe3O4@SiO2-cyclen nanoparticles were prepared and used as adsorbent for Cd2+, Pb2+ and Cu2+ from aqueous solution removal process controlled with differential pulse anodic stripping voltammetry (DPASV) and hanging mercury drop electrode (HDME). Nanomaterial was synthesised in three-step process co-precipitation of Fe3O4 core, coating with silane and N-(3-(triethoxysilyl)propyl)-1,4,7,10-tetraazacyclododecane-1-carboxamide silane functionalisation. The effectiveness of each step of the synthesis was confirmed using scanning electron microscopy (SEM), high-resolution X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (pXRD) and fourier-transform infrared spectroscopy (FT-IR) techniques. The Fe3O4@SiO2-cyclen nanoparticles were employed for Cd2+, Pb2+ and Cu2+ ions elimination from individual and mixed solutions by carrying out titration with a suspension of nanocomposites. The binding level for all ions both in the individual solutions and in the mixture was very similar at high levels. For Cd2+ and Cu2+ ions sorption efficiency level was from 83% to 89%, while for Pb2+ ions it was slightly lower at the level over 73%. In all cases, the equilibrium adsorption capacity parameter was over 1 mg/g and reached definitely higher values for individual ions solutions. The research results revealed that Fe3O4@SiO2- cyclen nanoparticles can be a promising adsorbent for magnetic heavy metal ions water treatment agents.

  • New Peptide Based Fluconazole Conjugates with Expanded Molecular Targets
    • Wioletta Brankiewicz
    • Joanna Okońska
    • Katarzyna Serbakowska
    • Jan Lica
    • Marek Drab
    • Natalia Ptaszyńska
    • Anna Łęgowska
    • Krzysztof Rolka
    • Piotr Szweda
    2022 Full text Pharmaceutics

    Infections of Candida spp. etiology are frequently treated with azole drugs. Among azoles, the most widely used in the clinical scenario remains fluconazole (FLC). Promising results in treatment of dangerous, systemic Candida infections demonstrate the advantages of combined therapies carried out with combinations of at least two different antifungal agents. Here, we report five conjugates composed of covalently linked FLC and cell penetrating or antimicrobial peptide: TP10-7-NH2, TP10-NH2, LFcinB(2-11)-NH2, LFcinB[Nle1,11]-NH2, and HLopt2-NH2, with aspects of design, chemical synthesis and their biological activities. Two of these compounds, namely FLCpOH-TP10-NH2 and FLCpOH-TP10-7-NH2, exhibit high activity against reference strains and fluconazole-resistant clinical isolates of C. albicans, including strains overproducing drug transporters. Moreover, both of them demonstrate higher fungicidal effects compared to fluconazole. Analysis performed with fluorescence and scanning electron microscopy as well as flow cytometry indicated the cell membrane as a molecular target of synthesized conjugates. An important advantage of FLCpOH-TP10-NH2 and FLCpOH-TP10-7-NH2 is their low cytotoxicity. The IC90 value for the human cells after 72 h treatment was comparable to the MIC50 value after 24 h treatment for most strains of C. albicans. In reported conjugates, FLC was linked to the peptide by its hydroxyl group. It is worth noting that conjugation of FLC by the nitrogen atom of the triazole ring led to practically inactive compounds. Two compounds produced by us and reported herein appear to be potential candidates for novel antifungal agents.

  • New Performance Indices for Power System Stabilizers
    • Michał Izdebski
    • Robert Małkowski
    • Piotr Miller
    2022 Full text ENERGIES

    The subject of the article is issues related to innovative indices for power system stabilizers (PSSs). These new indices will be able to quickly show which PSS (among many other PSSs) is not working properly and that advanced optimization and simulation methods should be used to improve the PSS settings. The authors note the fact that the acceptance requirements for PSSs are different in various power systems. Moreover, the authors pay attention to the fact that transmission system operators (TSOs) often have different PSS requirements (tests) even though they work in the same large power system. The article reviews the requirements for the PSSs used by TSOs of various power systems. The need to supplement the required tests with new qualitative indices is demonstrated. In the paper, new performance indices are proposed to improve the evaluation of the PSS and to check the desired performance of the stabilizer. These indices are derived from the active power frequency response characteristic with PSS and without PSS (PSS ON and PSS OFF). Additionally, the new PSS indices allow the graphical visualization of the properties of all synchronous generators equipped with the PSS in a predefined area on a single 3D graph. Such visualization can be used to quickly detect weak points of the power system.

  • New Simple and Robust Method for Determination of Polarity of Deep Eutectic Solvents (DESs) by Means of Contact Angle Measurement
    • Łukasz Cichocki
    • Dorota Warmińska
    • Justyna Łuczak
    • Andrzej Przyjazny
    • Grzegorz Boczkaj
    2022 Full text MOLECULES

    The paper presents a new method for evaluating the polarity and hydrophobicity of deep eutectic solvents (DESs) based on the measurement of the DES contact angle on glass. DESs consisting of benzoic acid derivatives and quaternary ammonium chlorides–tetrabutylammonium chloride (TBAC) and benzyldimethylhexadecylammonium chloride (16-BAC)—in selected molar ratios were chosen for the study. To investigate the DESs polarity, an optical goniometer and an ET(30) solvatochromic scale based on Reichardt’s dye were used. The research demonstrated the high accuracy and precision of the developed procedure. The simplicity of the examination and the availability of basic equipment allow for the implementation of the developed method in routine investigations of DESs.

  • Nieświadome sieci neuronowe
    • Stanisław Barański
    2022

    Coraz większą popularność zyskuje usługa predykcji za pomocą sieci neuronowych. Model ten zakłada istnienie serwera, który za pomocą wyuczonej sieci neuronowej dokonuje predykcji na danych otrzymanych od klienta. Model ten jest wygodny, ponieważ obie strony mogą skupić się na rozwoju w swojej specjalizacji. Wystawia on jednak na ryzyko utraty prywatności zarówno klienta, wysyła- jącego wrażliwe dane wejściowe, jak i serwer, udostępniający wy- uczony model sieci neuronowej. Niniejszy rozdział opisuje proces dokonywania nieświadomej predykcji za pomocą sieci neuronowych. Nieświadomość pozwala na dokonanie predykcji za pomocą sieci neu- ronowych przy zachowaniu prywatności danych wejściowych klienta oraz modelu serwera. Umożliwia świadczenie usług, które dotych- czas blokowane były przez regulacje prawne lub brak wiarygodności przetwarzających je systemów.

  • Niobate in silicate and phosphate glasses: Effect of glass basicity on crucible dissolution
    • Natalia Wójcik
    • Sharafat Ali
    • Efstratios Kamitsos
    • Doris Möncke
    2022 Full text International Journal of Applied Glass Science

    Using niobium crucibles for melting phosphate and silicate glasses of various modifier oxide contents, and therefore varying optical basicity (Λ), was found to result in varying dissolution rates of niobate during melting. Because of their high electronic polarizability, even small concentrations of niobates are detectable in the Raman spectra of glasses. Even less than 1 mol% Nb2O5 can be identified, as independently confirmed by SEM‐EDX analysis. Silica‐rich glasses (~60 % SiO2, Λ~0.6) did not show significant Nb dissolution from the crucible, while higher basicity metasilicate glasses (~ 50% SiO2, Λ~0.65) and pyrophosphate glasses (~30% P2O5, Λ~0.7) did show the typical niobate signature in the Raman spectra at 810‐840 cm‐1, depending on composition. While niobium is well dissolved throughout the pyrophosphate glass, metasilicate glasses showed a much more intense Raman signature of niobate units near the outer surface of the glass. Measurements along the cross section of a fractured metasilicate glass showed a steady decrease of the strength of the niobate signature from the surface toward the bulk of the material. Besides correlation with optical basicity, the tendency of melts to dissolve Nb crucible was discussed in terms of the connectivity or polymerization of the network and the corresponding melt viscosity.

  • Nitrate and nitrite silver complexes with weakly coordinating nitriles
    • Karolina Gutmańska
    • Anna Ciborska
    • Zbigniew Hnatejko
    • Anna Dołęga
    2022 Full text POLYHEDRON

    Simple system of weak nitrile ligands and silver nitrite/nitrate allowed the formation and isolation of coordination compounds of diverse nuclearity and dimensionality. The extension of the network does not enhance the luminescent properties of the ligands however it gives rise to the new MLCT bands in the visible region.

  • NLITED - New Level of Integrated Techniques for Daylighting Education: Preliminary Data on the Use of an E-learning Platform
    • Federica Giuliani
    • Natalia Sokół
    • Niko Gentile,
    • Mandana Khanie, Sarey
    • Valerio R.M. Lo Verso
    • Federica Caffaro
    2022

    Project NLITED – New Level of Integrated Techniques for Daylighting Education - is an educational project for students and professionals. The project's objective is to create and develop an online eLearning platform with 32 eModules dedicated to daylight knowledge. The project also offers e-learners two summer school training where the theory is put into practice. The platform was launched on January 31, 2022. The paper analyses the participation during the first four months of online activity until May 31, 2022. It discusses which eModules have received the highest participation rate and which have the lowest. These data are compared to the preferences on modules expressed by different panels of experts. The experts expressed their recommendations for specific educational content during workshops conducted in 2021, which led to the definition of the curriculum. Furthermore, participants also fill out an evaluation test on the quality and the usability of the eModule(s) they have taken. This information leads to the amendments of the ePlatform which are in the scope of action for the final year of the NLTED project.

  • Noise profiling for speech enhancement employing machine learning models
    • Krzysztof Kąkol
    • Grazina Korvel
    • Bożena Kostek
    2022 Full text Journal of the Acoustical Society of America

    This paper aims to propose a noise profiling method that can be performed in near real-time based on machine learning (ML). To address challenges related to noise profiling effectively, we start with a critical review of the literature background. Then, we outline the experiment performed consisting of two parts. The first part concerns the noise recognition model built upon several baseline classifiers and noise signal features derived from the Aurora noise dataset. This is to select the best-performing classifier in the context of noise profiling. Therefore, a comparison of all classifier outcomes is shown based on effectiveness metrics. Also, confusion matrices prepared for all tested models are presented. The second part of the experiment consists of selecting the algorithm that scored the best, i.e., Naïve Bayes, resulting in an accuracy of 96.76%, and using it in a noise-type recognition model to demonstrate that it can perform in a stable way. Classification results are derived from the real-life recordings performed in momentary and averaging modes. The key contribution is discussed regarding speech intelligibility improvements in the presence of noise, where identifying the type of noise is crucial. Finally, conclusions deliver the overall findings and future work directions.

  • Non-Adaptive Rotor Speed Estimation of Induction Machine in an Adaptive Full-Order Observer
    • Marcin Morawiec
    • Paweł Kroplewski
    • Charles Ikechukwu Odeh
    2022 Full text IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS

    In the sensorless control system of an induction machine, the rotor speed value is not measured but reconstructed by an observer structure. The rotor speed value can be reconstructed by the classical adaptive law with the integrator. The second approach, which is the main contribution of this paper, is the non-adaptive structure without an integrator. The proposed method of the rotor speed reconstruction is based on an algebraic relationship – the rank of the mathematical model of the observer system is not increased. However, the problem with the stabilization of the observer structure does exist. For near to zero rotor speed or in the regenerating mode of an induction machine, the speed observer structure can be unstable. Therefore, in this paper, the new stabilization functions are proposed. The stability is provided by the Lyapunov theorem and the practical stability theorems in which the uncertainty of parameters is considered. In the proposed solution, the newly introduced stabilization functions guarantee observer stability during both the motoring and regenerating conditions at the chosen low rotor speed ranges and for different load torque values. All the theoretical considerations were confirmed by simulation and experimental tests during the chosen working modes and uncertainties of nominal parameters of the induction machine.

  • Non-Adaptive Speed and Position Observer of Doubly-Fed Induction Generator
    • Marcin Morawiec
    • Krzysztof Blecharz
    • Arkadiusz Lewicki
    2022 Full text

    The non-adaptive speed and position estimation of a doubly-fed induction generator (DFIG) is presented in this paper. The speed observer is based on the mathematical model of DFIG and to stabilize the structure the Lyapunov method is used. The classic stator field-oriented control to active and reactive power control is used in the sensorless control system. The performance of the proposed algorithm of a speed observer is validated by simulation and experimental results using the 2 kW generator. The stability analysis of the presented solution is confirmed by using the Lyapunov method and practical stability theorems.

  • Non-Contact Monitoring of ECG in the Home Environment—Selecting Optimal Electrode Configuration
    • Adam Bujnowski
    • Kamil Osiński
    • Piotr Przystup
    • Jerzy Wtorek
    2022 Full text SENSORS

    Capacitive electrocardiography (cECG) is most often used in wearable or embedded measurement systems. The latter is considered in the paper. An optimal electrocardiographic lead, as an individual feature, was determined based on model studies. It was defined as the possibly highest value of the R-wave amplitude measured on the back of the examined person. The lead configuration was also analyzed in terms of minimizing its susceptibility to creating motion artifacts. It was found that the direction of the optimal lead coincides with the electrical axis of the heart. Moreover, the electrodes should be placed in the areas preserving the greatest voltage and at the same time characterized by the lowest gradient of the potential. Experimental studies were conducted using the developed measurement system on a group of 14 people. The ratio of the R-wave amplitude (as measured on the back and chest, using optimal leads) was less than 1 while the SNR reached at least 20 dB. These parameters allowed for high-quality QRS complex detection with a PPV of 97%. For the “worst” configurations of the leads, the signals measured were practically uninterpretable.

  • Non-Contact Temperature Measurements Dataset
    • Aleksander Mroziński
    2022 Full text

    The dataset titled The influence of the distance of the pyrometer from the surface of the radiating object on the accuracy of measurements contains temperature measurements using a selection of four commercially available pyrometers (CHY 314P, TM-F03B, TFA 31.1125 and AB-8855) as a function of the measuring distance. The dataset allows a comparison of the accuracy and measuring precision of the devices, which are very important features in the reliable non-contact prediction of COVID-19 symptoms without interference from external disturbances during fast patient recognition.

  • Nonconventional 1,8-Diazafluoren-9-One Aggregates for Green Light Enhancement in Hybrid Biocompatible Media
    • Aneta Lewkowicz
    • Mattia Pierpaoli
    • Katarzyna Walczewska-Szewc
    • Martyna Czarnomska
    • Piotr Bojarski
    • Robert Bogdanowicz
    • Stanisław Pogorzelski
    • Leszek Kułak
    • Jakub Karczewski
    2022 Full text Materials

    Organic aggregates currently play a prominent role, mainly for their unique optoelectronic properties in the aggregated state. Such properties can be related to the aggregates’ structure and the molecular packing mode. In the literature, we have well-established models of H and J aggregates defined based on the molecular exciton model. However, unconventional aggregates, the most unrecognized forms, have been generating interest among researchers recently. Within unconventional aggregation, aggregation-induced emission systems (AIE) are considered. In the present work, we discuss the effect of the forming of unconventional aggregation together with the change in dye concentration on the surface energy characteristics of the materials. All materials were prepared as hybrid biocompatible thin films where the matrix is TiO2 or TiO2/carbon nanowalls (CNWs) with the incorporated dye in the form of 1,8-diazafluoren-9-one (DFO). Using the time-resolved emission spectra and the determination of surface parameters from contact angle measurements, we indicated the correlation between the changes in such parameters and the concentration of DFO dye in two types of TiO2 and TiO2/CNW structures. To examine the propensity of DFO for aggregation, the internal energy of the dye was assessed in several aggregate structures using Quantum chemistry calculations. The results emphasize that DFO is an attractive structure in the design of new fluorophores due to its low molecular weight, the presence of a nitrogen atom that provides good coordination properties, and the ability to form hydrogen bonds. Our studies show that when using suitable matrices, i.e., rigid media, it forms the preferred forms of aggregates in the excited state, characterized by high emission efficiency in the band maximum of around 550 nm.

  • Non-Isocyanate-Based Waterborne Polyurethanes
    • Marcin Włoch
    • Iga Carayon
    2022

    Non-isocyanate polyurethanes (NIPUs) are a greener alternative for the conventional polyurethanes synthesized using toxic and moisture-sensitive di- or polyisocyanates. The most often described method of NIPU synthesis involves the reaction of five-membered cyclic carbonates with amines, and resulting polymers containing primary and secondary hydroxyl groups (so they are also known as polyhydroxyurethanes), which can be further used for the functionalization of such macromolecules. What cannot be omitted is an application of bio-based substrates in the synthesis of NIPUs, which presently may constitute more than 50 wt.% of such NIPU systems. Waterborne non-isocyanate polyurethanes (WNIPUs) can be prepared as solids, solutions, or dispersions by several different synthetic pathways. Broad-spectrum synthesis methods and used compounds may lead to sufficient molecular masses and mechanical properties on a laboratory scale. Some semi-products of such reactions can be further processed into thin films, coatings, hydrogels, or functionalized nanoparticles. Thus, careful selection of substrates, as in the case of isocyanate-based polyurethanes, provides many opportunities for valuable product fabrication. WNIPUs in the form of dispersions may find an application to cast films with great success, whereas the formation of latexes allows for coating formation. Coatings are the largest group of proposed WNIPU applications due to excellent adhesion, gloss, mechanical properties (flexibility and impact resistance), and thermal stability. Hydrogels are just after coatings because they are characterized by favorable mechanical properties and swelling capability. In this chapter, we describe the synthesis and properties of WNIPUs.

  • Non-Least Square GNSS Positioning Algorithm for Densely Urbanized Areas
    • Jerzy Demkowicz
    2022 Full text Remote Sensing

    The paper introduces an essentially new algorithm for calculating the GNSS position as an alternative to the least-square method. The proposed approach can be widely applied to any positioning method that uses multiple position lines for position calculation and is an example ofhow using a numerical solution can improve position accuracy without access to historical data. In essence, the method is based on the adaptation of the median filtering method widely used in the field of image processing, while at the same time applying a combinatorial approach and order statistics. The proposed solution makes it possible to improve on and assess the credibility of a single measurement. The article highlights the differences between the proposed and currently used approaches, as well as their advantages and disadvantages. The algorithm has been extensively tested under various environmental and weather conditions. The tests were carried out in typical and also in very demanding conditions, thus taking into account the real application context, i.e., pedestrian and car navigation in densely urbanized areas.

  • Non-Linear Analysis of Structures Utilizing Load-Discretization of Stiffness Matrix Method with Coordinate Update
    • Najmadeen Saeed
    • Ahmed Manguri
    • Marcin Szczepański
    • Robert Jankowski
    2022 Full text Applied Sciences-Basel

    This paper proposes a stiffness method based structural analysis algorithm for geometrically non-linear structures. In this study, the applied load on the joints has been discretized to a sequence of a few loadings applied. Each loading step produces incremental external nodal displacements, which are added to the corresponding coordinates to get a new geometrical shape of the structure. This process is iteratively repeated until the sum of the loading of all iterations matches the total initial applied loading. The size of the increments affects the technique’s accuracy, subsequently affecting the number of iterations. The configuration of non-linear geometrical structures is vital in the work; a slight change of the coordinates makes a considerable variation of nodal displacements. In this paper, three pin-jointed assemblies and a cantilever beam have been examined using the proposed technique; significantly reasonable outcomes emerged, compared to the non-linear approaches, such as Dynamic Relaxation Method (DRM) and Non-linear approach by Kwan. In a numerical sense, the dissimilarity between the results of the conventional Stiffness Matrix (SM) method and the non-linear method is about 228%, while the maximum discrepancy between the proposed approach and the non-linear methods is just above 15%

  • Nonlinear material identification of heterogeneous isogeometric Kirchhoff–Love shells
    • Bartosz Borzeszkowski
    • Izabela Lubowiecka
    • Roger Sauer
    2022 Full text COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING

    This work presents a Finite Element Model Updating inverse methodology for reconstructing heterogeneous materialdistributions based on an efficient isogeometric shell formulation. It uses nonlinear hyperelastic material models suitable fordescribing incompressible material behavior as well as initially curved shells. The material distribution is discretized by bilinearelements such that the nodal values are the design variables to be identified. Independent FE analysis and material discretization,as well as flexible incorporation of experimental data, offer high robustness and control. Three elementary test cases and oneapplication example, which exhibit large deformations and different challenges, are considered: uniaxial tension, pure bending,sheet inflation, and abdominal wall pressurization. Experiment-like results are generated from high-resolution simulations withthe subsequent addition of up to 4% noise. Local optimization based on the trust-region approach is used. The results showthat with a sufficient number of experimental measurements, design variables and analysis elements, the algorithm is capableto reconstruct material distributions with high precision even in the presence of large noise. The proposed formulation isvery general, facilitating its extension to other material models, optimization algorithms and meshing approaches. Adaptedmaterial discretizations allow for an efficient and accurate reconstruction of material discontinuities by avoiding overfitting dueto superfluous design variables. For increased computational efficiency, the analytical sensitivities and Jacobians are provided.

  • Nonlinear strain gradient and micromorphic one-dimensional elastic continua: Comparison through strong ellipticity conditions
    • Victor Eremeev
    • Emanuele Reccia
    2022 Full text MECHANICS RESEARCH COMMUNICATIONS

    We discuss the strong ellipticity (SE) conditions for strain gradient and micromorphic continua considering them as an enhancement of a simple nonlinearly elastic material called in the following primary material. Recently both models are widely used for description of material behavior of beam-lattice metamaterials which may possess various types of material instabilities. We analyze how a possible loss of SE results in the behavior of enhanced models. We shown that SE conditions for a micromorphic medium is more restrictive than for its gradient counterpart. On the other hand we see that a violation of SE for a primary material affects solutions within enhanced models even if the SE conditions are fulfilled for them.

  • NONLINEAR VIBRATION ANALYSIS OF BEAM AND PLATE WITH CLOSED CRACK: A REVIEW
    • Samrawit Alemayehu Tewelde
    • Marek Krawczuk
    2022 Full text Acta Mechanica et Automatica

    The effect of nonlinearity is high sensitivity in damage detection, especially for closed cracks and delamination. This review illustrates the results of several researchers dealing with nonlinear effects caused by the closure of cracks in the structure, i.e., beam and plate structures. Early detection of damage is an important aspect for the structure and, therefore, continuous progress is being made in developing new and effective methods that use nonlinear effects for early detection of damage and barely visible cracks, i.e., closed cracks and delamination, as well as for the determination of crack size and location. After analysing various methods, the merits, drawbacks and prospects of a number of nonlinear vibration methods for structural damage detection are discussed, and recommendations are made for future researchers

  • Nonlocal Models of Plates and Shells with Applications in Micro- and Nanomechanics
    • Mohammad Malikan
    2022 Full text

    Nowadays, the use of small-scale structures in micro/nanomachines has become more and more widespread. The most important applications of such small-sized parts are in micro-electro-mechanical systems (MEMS) as well as nano-electro-mechanical systems (NEMS) as actuators, sensors, energy harvesters. For example, nanosensors are nanoscale devices that measure physical quantities and convert these to signals that can be detected and analyzed. On the applications of micro/nanosensors in civil engineering, one can state that nanosensors can be developed and used in construction to monitor and/or control the environmental conditions and the materials/structures' performance. As an example, nanosensors can be used to monitor concrete corrosion and micro-cracking. The smart sensor can also be employed for structural health monitoring in bridges and other structures. In this regard, understanding the mechanical response of such structures in various environmental and physical situations is seriously required. For the design and modelling of such a device, one can use various approaches. First, we mention straightforward experiments which need special equipment and result in high costs. Second, molecular dynamics could be used, which requires a lot of computational efforts, in general. Moreover, this method cannot be implemented for all types of nanostructures. Finally, the application of continuum models properly modified for modelling materials and structures at small scales is worth mentioning. Among various enhancements of classic mechanics of continua and structures, we mention the non-local approach related to the description of long-range interactions. In what follows, we apply the third technique based on non-local models and corresponding modelling to thin-walled structures as principal elements of MEMS and NEMS. Moreover, we consider the coupling between mechanical and electromagnetic fields. So this dissertation is based on this approach. Using it, the mechanical behavior of the MEMS and NEMS has been predicted.

  • Nonlocalized thermal behavior of rotating micromachined beams under dynamic and thermodynamic loads
    • Ahmed E. Abouelregal
    • Hamid M. Sedighi
    • Mohammad Malikan
    • Victor Eremeev
    2022 Full text ZAMM-Zeitschrift fur Angewandte Mathematik und Mechanik

    Rotating micromachined beams are one of the most practical devices with several applications from power generation to aerospace industries. Moreover, recent advances in micromachining technology have led to huge interests in fabricating miniature turbines, gyroscopes and microsensors thanks to their high quality/reliability performances. To this end, this article is organized to examine the axial dynamic reaction of a rotating thermoelastic nanobeam under a constant-velocity moving load. Using Eringen’s nonlocal elasticity in conjunction with Euler–Bernoulli theory and Hamilton's principle, the governing equations are derived. It is assumed that the nanobeam is affected by thermal load and the boundary condition is simply supported. The Laplace transform approach is employed to solve the partial differential equations. A numerical example is presented to analyze the effects of the nonlocal parameter, rotation speed and velocity of the static moving load on the dynamic behavior of the system. The numerical results are graphically illustrated and analyzed to recognize the variations of field variables. Finally, in some special cases, our results are compared to those reported in the literature to demonstrate the reliability of the current model.

  • Non-Perfect Propagation of Information to a Noisy Environment with Self-Evolution
    • Piotr Mironowicz
    • Paweł Horodecki
    • Ryszard Horodecki
    2022 Full text ENTROPY

    We study the non-perfect propagation of information for evolving a low-dimensional environment that includes self-evolution as well as noisy initial states and analyse the interrelations between the degree of objectivization and environment parameters. In particular, we consider an analytical model of three interacting qubits and derive its objectivity parameters. The numerical analysis shows that the quality of the spectrum broadcast structure formed during the interaction may exhibit non-monotonicity both in the speed of self-dynamics of the environment as well as its mixedness. The former effect is particularly strong, showing that—considering part of the environment as a measurement apparatus—an increase of the external magnetic field acting on the environment may turn the vague measurement into close to ideal. The above effects suggest that quantum objectivity may appear after increasing the dynamics of the environment, although not with respect to the pointer basis, but some other, which we call the generalized pointer or indicator basis. Furthermore, it seems also that, when the objectivity is poor, it may be improved, at least by some amount, by increasing the thermal noise. We provide further evidence of this by analysing the upper bounds on distance to the set of states representing perfect objectivity in the case of a higher number of qubits.

  • Non-volatile molecular composition and discrimination of single grape white of chardonnay, riesling, sauvignon blanc and silvaner using untargeted GC–MS analysis
    • Bekzod Khakimov
    • Inal Bakhytkyzy
    • Carsten Fauhl-Hassek,
    • Søren Balling Engelsen
    2022 FOOD CHEMISTRY

    This study developed and applied a GC–MS method aiming at molecular fingerprinting of 120 commercial single grape white wines (Chardonnay, Riesling, Sauvignon Blanc and Silvaner) for possible authentication according to grape variety. The method allowed detection of 372 peaks and tentative identification of 146 metabolites including alcohols, organic acids, esters, amino acids and sugars. The grape variety effect explained 8.3% of the total metabolite variation. Univariate tests showed two-thirds of the metabolites being different between grape varieties. Partial least squares-discriminant analysis based classification models were developed for each grape variety and a panel of classifiers (42 metabolites) was established. All the classification models for grape variety showed a high certainty (>91%) for an independent test set. Riesling contained the highest relative concentrations of sugars and organic acids, while concentrations of hydroxytyrosol and gallic acid, common antioxidants in wine, decreased in the order of Chardonnay > Riesling > Sauvignon Blanc > Silvaner.

  • Notch fatigue analysis and life assessment using an energy field intensity approach in 7050-T6 aluminium alloy under bending-torsion loading
    • Ricardo Branco
    • José Domingos Costa
    • L.p. Borrego
    • Wojciech Macek
    • Filippo Berto
    2022 Full text INTERNATIONAL JOURNAL OF FATIGUE

    This paper studies the fatigue crack initiation and fatigue crack propagation of notched cylindrical bars made of 7050-T6 aluminium alloy subjected to multiaxial bending-torsion loading. The sites of crack initiation and the angles of crack initiation were successfully predicted from the distribution of the first principal stress at the notch surface. Fatigue crack initiation lives were computed through the new concept of energy field intensity formalised in a linear-elastic framework along with a local stress-strain model for notch plasticity analysis. Regardless of the model used to compute the cyclic response at the geometric discontinuity, the fatigue life predictions were in good agreement with the experimental observations.

  • Novel amides of mycophenolic acid and some heterocyclic derivatives as immunosuppressive agents
    • Juliusz Walczak
    • Dorota Iwaszkiewicz-Grześ
    • Michalina Ziomkowska
    • Magdalena Śliwka-Kaszyńska
    • Mateusz Daśko
    • Piotr Trzonkowski
    • Grzegorz Cholewiński
    2022 Full text JOURNAL OF ENZYME INHIBITION AND MEDICINAL CHEMISTRY

    The group of new amide derivatives of mycophenolic acid (MPA) and selected heterocyclic amines was synthesised as potential immunosuppressive agents functioning as inosine-5'-monophosphate dehydrogenase (IMPDH) uncompetitive inhibitors. The synthesis employed uronium-type activating system (TBTU/HOBt/DIPEA) while or phosphonic acid anhydride method (T3P/Py) facilitating amides to be obtained in moderate to excellent yields without the need of phenolic group protection. Most of optimised protocols did not require complicated reaction work-ups, including chromatographic, solvent- consuming methods. The biological activity assay was performed on the T-Jurkat cell line and peripheral mononuclear blood cells (PBMCs) which are both dedicated for antiproliferative activity determination. Each of designed derivatives was characterised by reduced cytotoxicity and benzoxazole analogue revealed the most promising activity. Subsequently, an observed structure-activity relationship was discussed.

  • Novel Binary Mixtures of Alkanolamine Based Deep Eutectic Solvents with Water—Thermodynamic Calculation and Correlation of Crucial Physicochemical Properties
    • Bartosz Nowosielski
    • Marzena Jamrógiewicz
    • Justyna Łuczak
    • Dorota Warmińska
    2022 Full text MOLECULES

    This paper demonstrates the assessment of physicochemical and thermodynamic properties of aqueous solutions of novel deep eutectic solvent (DES) built of tetrabutylammonium chloride and 3-amino-1-propanol or tetrabutylammonium bromide and 3-amino-1-propanol or 2-(methylamino)ethanol or 2-(butylamino)ethanol. Densities, speeds of sound, refractive indices, and viscosities for both pure and aqueous mixtures of DES were investigated over the entire range of compositions at atmospheric pressure and T = (293.15 - 313.15) K. It was concluded that the experimental data were successfully fitted using the Jouyban–Acree model with respect to the concentration. Obtained results showed that this mathematical equation is an accurate correlation for the prediction of aqueous DES properties. Key physicochemical properties of the mixtures—such as excess molar volumes, excess isentropic compressibilities, deviations in viscosity, and deviations in refractive indices—were calculated and correlated by the Redlich–Kister equation with temperaturedependent parameters. The non-ideal behavior of the studied systems were also evaluated by using the Prigogine−Flory−Patterson theory and the results were interpreted in terms of interactions between the mixture components.

  • Novel chalcone-derived pyrazoles as potential therapeutic agents for the treatment of non-small cell lung cancer
    • Natalia Maciejewska
    • Mateusz Olszewski
    • Jakub Jurasz
    • Marcin Serocki
    • Maria Dzierżyńska
    • Katarzyna Cekała
    • Ewa Wieczerzak
    • Maciej Bagiński
    2022 Full text Scientific Reports

    Lung cancer is considered to account for approximately one-fifth of all malignant tumor-related deaths worldwide and is therefore one of the most lethal malignancies. Pyrazole scaffold possesses a wide range of biological and pharmacological activities, which play important roles in medicinal chemistry. The present study reports the synthesis and in vitro biological characterization of nine pyrazoles derived from chalcones as potential anticancer agents for non-small cell lung cancer A-549, H226, and H460 cell lines. Most of the compounds efficiently inhibited the growth of all the tested cancer cell lines at micromolar concentrations. One of the most active compounds (PCH-1) was further evaluated for its effect on cell cycle distribution, apoptosis, migration, epithelial–mesenchymal transition, and oxidative stress. Furthermore, studies on the mechanism of action revealed that PCH-1 disrupts microtubule assembly, leading to cancer cell death. Molecular modeling studies confirmed the potent interaction of PCH-1 with the vinblastine binding site on tubulin. Overall, this study provides novel opportunities to identify anticancer agents in the pyrazole series.

  • Novel composite of Zn/Ti-layered double hydroxide coupled with MXene for the efficient photocatalytic degradation of pharmaceuticals
    • Anna Grzegórska
    • Izabela Wysocka
    • Paweł Głuchowski
    • Jacek Ryl
    • Jakub Karczewski
    • Anna Zielińska-Jurek
    2022 Full text CHEMOSPHERE

    In the present study, a hybrid photocatalyst of Zn/Ti layered double hydroxide (LDH) coupled with MXene – Ti3C2 was synthesized for the first time and applied in photocatalytic degradation of acetaminophen and ibuprofen, two commonly present in the natural environment and prone to accumulate in the aquatic ecosystem pharmaceuticals. The effect of MXene content (0.5 wt%, 2.5 wt%, and 5 wt%) on the photocatalytic activity of LDH/MXene composite was investigated. The composite of LDH/MXene containing 2.5 wt% of MXene revealed the highest photocatalytic activity in the degradation of acetaminophen (100% within 40 minutes) and ibuprofen (99.7% within 60 minutes). Furthermore, an improvement in acetaminophen and ibuprofen mineralization was observed for the composite material. Meanwhile, the introduction of interfering ions (Na+, Ca2+, Mg2+, Cl-, SO42-) in the model seawater did not affect the removal efficiency of both pharmaceuticals. The photocatalytic experiment performed in the four subsequent cycles, as well as FTIR, TEM, and XPS analyses after the photodegradation process confirmed the excellent stability and reusability of the prepared composite material. In order to evaluate the effect of various reactive oxidizing species (ROS) on the photocatalytic process, the trapping experiment was applied. It was noticed that •O2- had the main contribution in photocatalytic degradation of acetaminophen, while •OH and h+ mainly affected the degradation of ibuprofen. Finally, based on the results of Mott Schottky analysis, bandgap calculation, and ROS trapping experiment, the possible mechanism for pharmaceuticals degradation was proposed. This research illustrates the feasibility and novelty of the treatment of pharmaceuticals by LDH/MXene composites, implying that MXene plays a significant role in the electron-hole separation and thus high photocatalytic activity.

  • Novel Interpolation Method of Multi-DFT-Bins for Frequency Estimation of Signal with Parameter Step Change
    • Kai Wang
    • Shan Liu
    • Lanlan Wang
    • Janusz Smulko
    • He Wen
    2022 Full text IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT

    The IpDFT(Interpolation Discrete Fourier Trans-form) method is one of the most commonly used non-parametric methods. However, when a parameter (frequency, amplitude or phase) step changes in the DFT period, the DFT coefficients will be distorted seriously, resulting in the large estimation error of the IpDFT method. Hence, it is a key challenge to find an IpDFT method, which not only can eliminate the effect of the step-changed symbol, but also can sufficiently eliminate the fence effect and the spectrum leakage. In this paper, an IpDFT based method is proposed to estimate the frequency of the single tone signal with the step-changed parameters in the sampling signal sequence. The relationship between the DFT bins and the step changed parameters is given by several linear equations. At most six different DFT bins are used to eliminate the effect of symbol.

  • Novel Low-Loss Substrates for 5G Applications
    • Krzysztof Babicki
    • Adam Lamęcki
    • Michał Mrozowski
    • Michał Baranowski
    • Anna Wroblewska
    • Mariusz Zdrojek
    • Bartlomiej Salski
    • Jerzy Krupka
    2022

    This paper presents a feasibility study of a new type of microwave low-loss dielectric substrates for 5G network applications. The new substrate materials are composites of polypropylene and high-dielectric-constant micro-ceramics. This combination is expected to form a very low-loss dielectric material at low fabrication cost. Two substrate samples with different dielectric properties are fabricated and their characteristics at microwave frequencies are investigated in this paper. The investigation covers two scenarios for the metallization of the substrates to form printed circuit boards. The dielectric properties of the materials are measured using the split post dielectric resonator technique. Furthermore, the quality of the materials is experimentally verified though the design, fabrication, and measurement of simple resonator structures

  • Novel method of estimation of inertial and dissipative parameters of a railway pantograph model
    • Andrzej Wilk
    • Len Gelman
    • Sławomir Judek
    • Krzysztof Karwowski
    • Mirosław Mizan
    • Tadeusz Maciołek
    • Miroslaw Lewandowski
    • Aleksander Jakubowski
    • Karolina Klimowska
    2022 Full text VEHICLE SYSTEM DYNAMICS

    An increase in electric railway vehicles service velocity requires that correct interaction between the pantograph and the catenary is ensured. This implies the need for developing mathematical models of pantographs and catenaries and determining their parameters. The article presents a method to determine parameters of mechanical joints of a railway pantograph based on analysis of pantograph subassemblies in swinging motion. The experimental tests consisted in disassembling the pantograph and creating partial subassemblies which were then analysed with respect to their damped linear or angular oscillations. The simulation analysis required developing, in CAD, 3D models of individual pantograph parts and their subassemblies. Defined were joints between particular elements, which represent of real pantograph structure. The inertia parameters of the model were determined, based on structural characteristics and physical properties of materials, used for manufacturing individual pantograph elements, and then verified experimentally. The dissipative parameters of the mechanical joints were calculated iteratively. The model of complete pantograph assembly was also subject to verification and in this case, good convergence between simulation and experiment results was achieved. The obtained parameter values can be used in simulation models of other railway pantographs having a similar structure.

  • Novel Nonlinear High Order Technologies for Damage Diagnosis of Complex Assets
    • Tomasz Ciszewski
    • Len Gelman
    • Andrew Ball
    2022 Full text Electronics

    For the first time worldwide, innovative techniques, generic non-linear higher-order unnormalized cross-correlations of spectral moduli, for the diagnosis of complex assets, are proposed. The normalization of the proposed techniques is based on the absolute central moments, that have been proposed and widely investigated in mathematical works. The existing higher-order, crosscovariances of complex spectral components are not sufficiently effective. The novel technology is comprehensively experimentally validated for induction motor bearing diagnosis via motor current signals. Experimental results, provided by the proposed technique, confirmed high overall probabilities of correct diagnoses for bearings at early stages of damage development. The proposed diagnosis technology is compared with existing diagnosis technology, based on the triple cross-covariance of complex spectral components.