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Politechniki Gdańskiej

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  • ELECTRICAL CONDUCTIVITY AND pH IN SURFACE WATER AS TOOL FOR IDENTIFICATION OF CHEMICAL DIVERSITY
    • Joanna Potapowicz
    • Danuta Szumińska
    • Małgorzata Szopińska
    • Czapiewski Sebastian
    • Żaneta Polkowska
    2020 Pełny tekst Ecological Chemistry and Engineering S - Chemia i Inżynieria Ekologiczna S

    In the present study, the creeks and lakes located at the western shore of Admiralty Bay were analysed. The impact of various sources of water supply was considered, based on the parameters of temperature, pH and specific electrolytic conductivity (SEC25). All measurements were conducted during a field campaign in January-February 2017. A multivariate dataset was also created and a biplot of SEC25 and pH of the investigated waters was performed. The average temperatures of the investigated waters were 0.10-8.10 °C. The pH values indicate that most of the water environments of the analysed area are slightly acidic to alkaline (5.26-8.50) with two exceptions: Siodlo II Creek (9.26) and Petrified Forest Creek (8.95), which are characterised by greater alkalinity. At the measurement points closest to the Baranowski Glacier and Ecology Glacier, SEC25 values were the lowest (26.8-61.1 μS·cm–1), while the remaining values ranged from 79.0 to 382 μS·cm–1 for the whole studied area. Based on the results it is concluded that the periodic intensive inflow of ablation waters, combined with morphological changes in the glacier front, causes a significant variability in the outflow network, creating the conditions for changes in basic physicochemical parameters. Moreover, it is observed that local depressions in the terrain form sedimentation traps in which, alongside fine-grained deposits, compounds can accumulate that originate from in situ sedimentation and that are also associated with surface runoff from the melting of snow cover, buried ice and permafrost.

  • Electrical conductivity of nanostructured acceptor-doped ceria fabricated by spark plasma sintering (SPS)
    • Ahsanul Kabir
    • Sofie Colding-Jørgensen
    • Sebastian Molin
    • Vincenzo Esposito
    2020 MATERIALS LETTERS

    High purity nanoscale powders (~10–15 nm size) of two different compositions of ceria, doped with Gd3+ and Ca2+, have been consolidated by spark plasma sintering (SPS) at different temperatures. Fully-dense samples were observed only at a sintering temperature of 980 °C. The as-sintered samples showed rather fast grain growth with an average grain size below 300 nm. The electrical properties of the samples were evaluated by impedance spectroscopy over a wide range of temperatures (300–550 °C) in air. Electrical conductivity significantly enhanced with increasing sintering temperature. The compounds show an electrical blocking effect at the grain boundary, depending on the doping cations.

  • Electrochemical and in silico approaches for liver metabolic oxidation of antitumor-active triazoloacridinone C -1305
    • Agnieszka Potęga
    • Dorota Żelaszczyk
    • Zofia Mazerska
    2020 Pełny tekst Journal of Pharmaceutical Analysis

    5-Dimethylaminopropylamino-8-hydroxytriazoloacridinone (C-1305) is a promising antitumor compound developed in our laboratory. A better understanding of its metabolic transformations is still needed to explain the multidirectional mechanism of pharmacological action of triazoloacridinone derivatives at all. Thus, the aim of the current work was to predict oxidative pathways of C-1305 that would reflect its phase I metabolism. The multi-tool analysis of C-1305 metabolism included electrochemical conversion and in silico sites of metabolism predictions in relation to liver microsomal model. In the framework of the first approach, an electrochemical cell was coupled on-line to an electrospray ionization mass spectrometer. The effluent of the electrochemical cell was also injected onto a liquid chromatography column for the separation of different products formed prior to mass spectrometry analysis. In silico studies were performed using MetaSite software. Standard microsomal incubation was employed as a reference procedure. We found that C-1305 underwent electrochemical oxidation primarily on the dialkylaminoalkylamino moiety. An unknown so far N-dealkylated and hydroxylated C-1305 products have been identified. The electrochemical system was also able to simulate oxygenation reactions. Similar pattern of C-1305 metabolism has been predicted using in silico approach. Both proposed strategies showed high agreement in relation to the generated metabolic products of C-1305. Thus, we concluded that they can be considered as simple alternatives to enzymatic assays, affording time and cost efficiency.

  • Electrochemical detection of 4,4',5,5'-tetranitro-1H,1'H-2,2'-biimidazole on boron-doped diamond/graphene nanowall electrodes
    • Anna Dettlaff
    • Paweł Jakóbczyk
    • Michał Sobaszek
    • Mateusz Ficek
    • Bartłomiej Dec
    • Aneta Łuczkiewicz
    • Mateusz Szala
    • Jacek Wojas
    • Tadeusz Ossowski
    • Robert Bogdanowicz
    2020 Pełny tekst IEEE SENSORS JOURNAL

    We present a promising approach to the electroanalytical detection of a specific nitroaromatic explosive in landfill leachates (LLs) that originated from a municipal solid waste plant. The paper is focused but not limited to the sensing of 4,4',5,5'-tetranitro-1H,1'H-2,2'-biimidazole (TNBI) using differential pulse voltammetry and cyclic voltammetry. Highly electroactive nanocarbon was applied to determine low concentrations of the analyte in the complex interfering matrix as leachate samples. The mechanism of nitro- group reduction is attributed to the sensing effect, as revealed in the voltammograms of TNBI. The developed sensor model has two linear regions extending from 0.02 ppm to 1.4 ppm and from 2 ppm to 16 ppm resulting from adsorption and diffusion-controlled processes, respectively. The limit of detection was as low as 0.52 ppm (1.66 μM L-1) thanks to the electrochemical performance of the joint effect of the diamond/graphene composite nanowall surface.

  • Electrochemical determination of nitroaromatic explosives at boron-doped diamond/graphene nanowall electrodes: 2,4,6-trinitrotoluene and 2,4,6-trinitroanisole in liquid effluents
    • Anna Dettlaff
    • Paweł Jakóbczyk
    • Mateusz Ficek
    • B. Wilk
    • M. Szala
    • J. Wojtas
    • Tadeusz Ossowski
    • Robert Bogdanowicz
    2020 Pełny tekst JOURNAL OF HAZARDOUS MATERIALS

    The study is devoted to the electrochemical detection of trace explosives on boron-doped diamond/graphene nanowall electrodes (B:DGNW). The electrodes were fabricated in a one-step growth process using chemical vapour deposition without any additional modifications. The electrochemical investigations were focused on the determination of the important nitroaromatic explosive compounds, 2,4,6-trinitrotoluene (TNT) and 2,4,6-trinitroanisole (TNA). The distinct reduction peaks of both studied compounds were observed regardless of the pH value of the solution. The reduction peak currents were linearly related to the concentration of TNT and TNA in the range from 0.05–15 ppm. Nevertheless, two various linear trends were observed, attributed respectively to the adsorption processes at low concentrations up to the diffusional character of detection for larger contamination levels. The limit of detection of TNT and TNA is equal to 73 ppb and 270 ppb, respectively. Moreover, the proposed detection strategy has been applied under real conditions with a significant concentration of interfering compounds – in landfill leachates. The proposed bare B:DGNW electrodes were revealed to have a high electroactive area towards the voltammetric determination of various nitroaromatic compounds with a high rate of repeatability, thus appearing to be an attractive nanocarbon surface for further applications.

  • Electrochemical oxidation of PFOA and PFOS in landfill leachates at low and highly boron-doped diamond electrodes
    • Mattia Pierpaoli
    • Małgorzata Szopińska
    • Barbara Wilk
    • Michał Sobaszek
    • Aneta Łuczkiewicz
    • Robert Bogdanowicz
    • Sylwia Fudala-Książek
    2020 Pełny tekst JOURNAL OF HAZARDOUS MATERIALS

    Polyfluorinated alkyl substances (PFASs) may reach landfill leachates (LLs) due to improper waste management. In this study perfluorooctanoate (PFOA) and perfluorooctane sulphonate (PFOS) were used as representatives of PFASs in the decomposition on boron-doped diamond electrodes (BDDs) with high (10k ppm) and low (0.5k ppm) boron doping concentrations. The result shows that although better COD removal efficacies are obtained on the low-doped BDD (59 % after 8 h), the decomposition rate of PFOA and PFOS was not affected by boron doping. In LLs, at the current density of 75 mA/cm2, averaged removal efficiencies of 80 % and 78 % were achieved for PFOA and PFOS, respectively. But besides concentration of mother compounds, the presence of intermediates during electrolysis should be monitored. After 8 h of LL electrolysis, the presence of long-chain degradates C6 F13 and C6 F13 COO˗ was still observed only in 10k BDD-PFOA assays, while during 0.5k assays C 6F13 and C6 F13 COO˗ form more intesively at the beginning of the process. This indirectly confirms the more intensive generation of perfluoroalkoxy and hydroxyl radicals and higher susceptibility to electrolysis of PFOA’s long-chain intermediates on 0.5k BDD. This is the first study reporting BDD-electrolysis as promising in PFAS removal from the complex matrix of LLs, despite the oxidation of competing LLs components.

  • Electrochemical performance of thin free-standing boron-doped diamond nanosheet electrodes
    • Robert Bogdanowicz
    • Mateusz Ficek
    • Natalia Malinowska
    • Sanju Gupta
    • Romney Meek
    • Paweł Niedziałkowski
    • Michał Rycewicz
    • Sawczak Mirosław
    • Jacek Ryl
    • Tadeusz Ossowski
    2020 Pełny tekst JOURNAL OF ELECTROANALYTICAL CHEMISTRY

    In the following work we describe preparation and the electrochemical performance of thin and free-standing heavy boron-doped diamond (BDD) nanosheets. The investigated foils were deposited on Ta substrate using microwave plasma-enhanced chemical vapor deposition technique (MPECVD). Foils of two B-dopant densities were investigated, obtained on the base of 10 k and 20 k ppm [B]/[C] ratio in the gas admixture. The obtained foils can be easily peeled from substrate in deionized water to be then attached to other material, in this case polydimethylsiloxane (PDMS). We have shown that the top surface and the bottom side of investigated boron-doped diamond nanosheet possess significantly altered morphology and physico-chemical properties, revealed by electron microscopy, Raman spectroscopy and electrochemistry. The voltammetric response of investigated BDD foils as working electrodes indicates the highest activity for the nanosheet with higher dopant concentration, in particular on its top surface. Furthermore, electrodes are characterized with altered kinetics, characteristic for partially blocked electrodes with quasi-reversible charge transfer.

  • Electrochemical, theoretical and surface physicochemical studies of the alkaline copper corrosion inhibition by newly synthesized molecular complexes of benzenediamine and tetraamine with π acceptor
    • Mohamed Ibrahim
    • Gaber Mersal
    • Ahmed Fallatah
    • Murat Saracoglu
    • Fatma Kandemirli
    • Sarah Alharthi
    • Sabine Szunerits
    • Rabah Boukherroub
    • Jacek Ryl
    • Mohammed Amin
    2020 JOURNAL OF MOLECULAR LIQUIDS

    Two charge transfer complexes, namely [(BDAH)+(PA−)] CT1 [(BTAH)2+(PA−)2] and CT2 (BDAH = 1,2-benzenediamine, BTAH = 1,2,4,5-benzenetetramine, and PA− = 2,4,6-trinitrophenolate), were synthesized and fully characterized using various spectroscopic techniques. CT1 and CT2 were tested as inhibitors to effectively control the uniform and anodic corrosion processes of copper in an alkaline electrolyte (1.0 M KOH) using various electrochemical techniques. As a reference point, results were compared with the potassium salt of the π-acceptor potassium 2,4,6-trinitrophenolate (designated here as PA−K+). The highest inhibition efficiency (97%) was recorded for inhibitor CT2 at a concentration of 1.0 mM. The inhibition mechanism was discussed based on scanning electron microscopy and X-ray photoelectron spectroscopy results of the corroded and inhibited Cu surfaces. A theoretical study, based on quantum-chemical calculations of the synthesized compounds, performed by the DFT/B3LYP method with a 6-311++G(2d,2p) basis set by using Gaussian 09, Revision A.02 program, was also included to support experimental findings. The various quantum chemical parameters such as EHOMO, ELUMO, chemical hardness, and chemical softness of the investigated molecules were calculated, and their correlation with the inhibition efficiency of the synthesized compounds was discussed.

  • Electrochemically directed biofunctionalization of a lossy-mode resonance optical fiber sensor
    • Monika Janik
    • Paweł Niedziałkowski
    • Katarzyna Lechowicz
    • Marcin Koba
    • Petr Sezemsky
    • Vitezslav Stranak
    • Tadeusz Ossowski
    • Mateusz Śmietana
    2020 Pełny tekst OPTICS EXPRESS

    In this work, we present a direct electrochemical biofunctionalization of an indium-tin-oxide-coated lossy-mode resonance optical fiber sensor. The functionalization using a biotin derivative was performed by cyclic voltammetry in a 10 mM biotin hydrazide solution. All stages of the experiment were simultaneously verified with optical and electrochemical techniques. Performed measurements indicate the presence of a poly-biotin layer on the sensor’s surface. Furthermore, dual-domain detection of 0.01 and 0.1 mg/mL of avidin confirms the sensor’s viability for label-free detection.

  • Electro-chemo-mechanical properties in nanostructured Ca-doped ceria (CDC) by field assisted sintering
    • Ahsanul Kabir
    • Haiwu Zhang
    • Sofie Colding-Jørgensen
    • Simone Santucci
    • Sebastian Molin
    • Vincenzo Esposito
    2020 Pełny tekst SCRIPTA MATERIALIA

    Recent investigations have shown that highly oxygen defective cerium oxides generate non-classical electrostriction that is superior to lead-based ferroelectrics. In this work, we report the effect of field-assisted spark plasma sintering (SPS) on electro-chemo-mechanical properties of calcium doped ceria (CDC). Nanometric powders of Ca.10 nm are rapidly consolidated to form polycrystalline nanostructures with a high degree of crystalline disorder. Remarkably, the resultant material demonstrates a large electromechanical strain without a frequency-related relaxation effect. We conclude that electromechanical activity in CDC materials strictly depends on the Ca2+- interaction, while disorder at the crystalline boundaries has a minor effect.

  • Electrodeposited Biocoatings, Their Properties and Fabrication Technologies: A Review
    • Andrzej Zieliński
    • Michał Bartmański
    2020 Pełny tekst Coatings

    Coatings deposited under an electric field are applied for the surface modification of biomaterials. This review is aimed to characterize the state-of-art in this area with an emphasis on the advantages and disadvantages of used methods, process determinants, and properties of coatings. Over 170 articles, published mainly during the last ten years, were chosen, and reviewed as the most representative. The most recent developments of metallic, ceramic, polymer, and composite electrodeposited coatings are described focusing on their microstructure and properties. The direct cathodic electrodeposition, pulse cathodic deposition, electrophoretic deposition, plasma electrochemical oxidation in electrolytes rich in phosphates andcalciumions, electro-spark, andelectro-dischargemethods are characterized. The effects of electrolyte composition, potential and current, pH, and temperature are discussed. The review demonstrates that the most popular are direct and pulse cathodic electrodeposition and electrophoretic deposition. The research is mainly aimed to introduce new coatings rather than to investigate the effects of process parameters on the properties of deposits. So far tests aim to enhance bioactivity, mechanical strength and adhesion, antibacterial efficiency, and to a lesser extent the corrosion resistance.

  • Electrodes criticality: the impact of CRMs in the leachate electrochemical oxidation
    • Mattia Pierpaoli
    • Michał Rycewicz
    • Aneta Łuczkiewicz
    • Sylwia Fudala-Książek
    • Robert Bogdanowicz
    • Maria Letizia Ruello
    2020 Pełny tekst Manufacturing Review

    . Landfill leachate possesses high concentrations of ammonia, micropollutants, and heavy metals, and are characterised for low biodegradability. For this reason, conventional treatment technologies may result ineffective for complete pollutant removal. Electrochemical oxidation allows most of the of recalcitrant pollutants to be oxidised effectively within an easy operational and acceptable retention time, without the need to provide additional chemicals, and without producing waste materials. The mineralisation efficiency and electrode durability depend on the nature of the electrode material. The conventionally adopted anodes can contain critical raw materials (CRMs), and are subject to extreme corrosion conditions. CRM-free electrodes, such as carbon and graphite-based, exhibit a lower efficiency, and are subject to faster deactivation, or, as for lead-dioxide-based electrodes, can constitute a hazard due to the release into the effluent of the coating corrosion products. In this study, the relationship between electrode type, CRM content, and the removal efficiencies of organic compounds and ammonium-nitrogen (N-NH4) was investigated. Material criticality was estimated by the supply risk with economic importance indexes reported in the 2017 EU CRM List. The COD and N-NH4 removal efficiencies were obtained from a literature analysis of 25 publications. The results show that, while single and multi-oxide-coated electrodes may contain low amounts of CRM, but with limited efficiency, borondoped diamonds (BDD) may constitute the best compromise in terms of a reduced content of CRM and a high mineralisation efficiency.

  • Electromagnetic Modeling of Microstrip Elements Aided with Artificial Neural Network
    • Łukasz Sorokosz
    • Włodzimierz Zieniutycz
    2020 Pełny tekst

    The electromagnetic modeling principle aided withartificial neural network to designing the microwave widebandelements/networks prepared in microstrip technology is proposedin the paper. It is assumed that the complete information is knownfor the prototype design which is prepared on certain substratewith certain thickness and electric permittivity. The longitudinaland transversal dimensions of new design are calculated sep-arately using the scale coefficients which are determined fromtransmission line equation. Next the artificial neural networkcan be used for final tuning which should take into accountthe dispersion of microstrip line. The verification of proposedprocedure is shown for exemplary planar UWB balun.

  • Electromagnetic Simulation with 3D FEM for Design Automation in 5G Era
    • Łukasz Balewski
    • Michał Baranowski
    • Maciej Jasiński
    • Adam Lamęcki
    • Michał Mrozowski
    2020 ZTE COMMUNICATIONS

    Electromagnetic simulation and electronic design automation (EDA) play an important role in the design of 5G antennas and radio chips. The simulation challenges include electromagnetic effects and long simulation time and this paper focuses on simulation software based on finite-element method (FEM). The state-of-the-art EDA software using novel computational techniques based on FEM can not only accelerate numerical analysis, but also enable optimization, sensitivity analysis and interactive design tuning based on rigorous electromagnetic model of a device. Several new techniques that help to mitigate the most challenging issues related to FEM based simulation are highlighted. In particular, methods for fast frequency sweep, mesh morphing and surrogate models for efficient optimization and manual design tuning are briefly described, and their efficiency is illustrated on examples involving a 5G multiple-input multiple-output (MIMO) antenna and filter. It is demonstrated that these new computational techniques enable significant reduction of time needed for design closure with the acceleration rates as large as tens or even over one hundred.

  • Electronic structure calculations in electrolyte solutions: Methods for neutralization of extended charged interfaces
    • Arihant Bhandari
    • Lucian Anton
    • Jacek Dziedzic
    • Chao Peng
    • Denis Kramer
    • Chris-Kriton Skylaris
    2020 Pełny tekst JOURNAL OF CHEMICAL PHYSICS

    Density functional theory (DFT) is often used for simulating extended materials such as infinite crystals or surfaces, under periodic boundary conditions (PBCs). In such calculations, when the simulation cell has non-zero charge, electrical neutrality has to be imposed, and this is often done via a uniform background charge of opposite sign (“jellium”). This artificial neutralization does not occur in reality, where a different mechanism is followed as in the example of a charged electrode in electrolyte solution, where the surrounding electrolyte screens the local charge at the interface. The neutralizing effect of the surrounding electrolyte can be incorporated within a hybrid quantum–continuum model based on a modified Poisson–Boltzmann equation, where the concentrations of electrolyte ions are modified to achieve electroneutrality. Among the infinite possible ways of modifying the electrolyte charge, we propose here a physically optimal solution, which minimizes the deviation of concentrations of electrolyte ions from those in open boundary conditions (OBCs). This principle of correspondence of PBCs with OBCs leads to the correct concentration profiles of electrolyte ions, and electroneutrality within the simulation cell and in the bulk electrolyte is maintained simultaneously, as observed in experiments. This approach, which we call the Neutralization by Electrolyte Concentration Shift (NECS), is implemented in our electrolyte model in the Order-N Electronic Total Energy Package (ONETEP) linear-scaling DFT code, which makes use of a bespoke highly parallel Poisson–Boltzmann solver, DL_MG. We further propose another neutralization scheme (“accessible jellium”), which is a simplification of NECS. We demonstrate and compare the different neutralization schemes on several examples.

  • Electron-impact ionization cross section calculations for 5-chloropyridine and 5-bromopyridine molecules
    • Bożena Żywicka
    • Paweł Możejko
    2020 Pełny tekst Journal of Physics : Conference Series

    The total cross sections for the single electron-impact ionization of 5-chloropyridine (5-C5H4ClN) and 5-bromopyridine (5-C5H4BrN) molecules have been calculated using binary-encounter-Bethe method for electron energies ranging from the ionization threshold up to 5 keV.

  • Electron-impact ionization cross section calculations for selected ribonucleosides
    • Paweł Możejko
    2020 Pełny tekst Journal of Physics : Conference Series

    Total cross sections for the single electron-impact ionization of selected ribonuclosides (guanosine, adenosine, cytidine and uridine) have been calculated for electron energies ranging from the ionization threshold up to 5 keV.

  • Electrophoretic Deposition and Characteristics of Chitosan–Nanosilver Composite Coatings on a Nanotubular TiO2 Layer
    • Michał Bartmański
    • Łukasz Pawłowski
    • Andrzej Zieliński
    • Aleksandra Mielewczyk-Gryń
    • Gabriel Strugała
    • Bartłomiej Cieślik
    2020 Pełny tekst Coatings

    The surface treatment of titanium implants has been applied mainly to increase surface bioactivity and, more recently, to introduce antibacterial properties. To this end, composite coatings have been investigated, particularly those based on hydroxyapatite. The present research was aimed at the development of another coating type, chitosan–nanosilver, deposited on a Ti13Zr13Nb alloy. The research comprised characterization of the coating’s microstructure and morphology, timedependent nanosilver dissolution in simulated body fluid, and investigation of the nanomechanical properties of surface coatings composed of chitosan and nanosilver, with or without a surface-active substance, deposited at different voltages for 1 min on a nanotubular TiO2 layer. The microstructure, morphology, topography, and phase composition were examined, and the silver dissolution rate in simulated body fluid, nanoscale mechanical properties, and water contact angle were measured. The voltage value significantly influenced surface roughness. All specimens possessed high biocompatibility. The highest and best adhesion of the coatings was observed in the absence of a surface-active substance. Silver dissolution caused the appearanc

  • Electrophoretic Deposition and Characterization of Chitosan/Eudragit E 100 Coatings on Titanium Substrate
    • Łukasz Pawłowski
    • Michał Bartmański
    • Gabriel Strugała
    • Aleksandra Mielewczyk-Gryń
    • Magdalena Jażdżewska
    • Andrzej Zieliński
    2020 Pełny tekst Coatings

    Currently, a significant problem is the production of coatings for titanium implants, which will be characterized by mechanical properties comparable to those of a human bone, high corrosion resistance, and low degradation rate in the body fluids. This paper aims to describe the properties of novel chitosan/Eudragit E 100 (chit/EE100) coatings deposited on titanium grade 2 substrate by the electrophoretic technique (EPD). The deposition was carried out for different parameters like the content of EE100, time of deposition, and applied voltage. The microstructure, surface roughness, chemical and phase composition, wettability, mechanical and electrochemical properties, and degradation rate at different pH were examined in comparison to chitosan coating without the addition of Eudragit E 100. The applied deposition parameters significantly influenced the morphology of the coatings. The chit/EE100 coating with the highest homogeneity was obtained for Eudragit content of 0.25 g, at 10 V, and for 1 min. Young’s modulus of this sample (24.77 ± 5.50 GPa) was most comparable to that of human cortical bone. The introduction of Eudragit E 100 into chitosan coatings significantly reduced their degradation rate in artificial saliva at neutral pH while maintaining high sensitivity to pH changes. The chit/EE100 coatings showed a slightly lower corrosion resistance compared to the chitosan coating, however, significantly exceeding the substrate corrosion resistance. All prepared coatings were characterized by hydrophilicity.

  • Elektryczne zespoły zasobnikowe jako alternatywa dla elektryfikacji nowych linii w Trójmieście = Electric Multiple Units With Energy Storage – Alternative to Electrification of New Lines in Three City
    • Dariusz Karkosiński
    • Dominika Macedońska
    • Natalia Karkosińska-Brzozowska
    2020 Automatyka Elektryka Zakłócenia

    Rozważono zastosowanie nowoczesnych zespołów trakcyjnych na liniach pasażerskich Trójmiasta. Zaproponowano budowę linii Gdańsk Śródmieście - Orunia Górna oraz odtworzenie komunikacji do północnych dzielnic Gdyni. Przeanalizowano trójmiejski układ komunikacyjny dla ruchu pociągów z zasobnikami energii. Zaproponowano trasę Orunia Górna - Wrzeszcz - Osowa - Chylonia - Port Oksywie z naprzemiennie występującymi odcinkami zelektryfikowanymi i niezelektryfikowanymi Wykonano wstępne obliczenia.

  • Elementy uczenia maszynowego na zajęciach matematyki
    • Agnieszka Bartłomiejczyk
    • Dawid Ptach
    • Marcin Wata
    2020 Pełny tekst Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej

    W artykule omówiono związki między matematyką kursową a wybranymi zagadnieniami związanymi z uczeniem maszynowym. Pokazano w jaki sposób proste operacje na macierzach pomagają serwisom VOD w rekomendacji tytułów filmowych zgodnych z zainteresowaniami użytkowników na podstawie ich wcześniejszych wyborów. Zaprezentowano również uproszczoną wersję algorytmu regresji wielorakiej stosowaną do wyceny nieruchomości oraz wspomniano o zastosowaniu sieci neuronowych w problemach klasyfikacyjnych.

  • Ella4Life virtual assistant - user centered design strategy - evaluation following labolatory tests
    • Mariusz Kaczmarek
    • Adam Bujnowski
    • Kamil Osiński
    • Edith Birrer
    • Tomasz Neumann
    • Barry Teunissen
    2020

    In the paper, we summarize the evaluation of Anne4Care system after laboratory tests. A group of end users, seniors over 55 years of age, rated a virtual assistant by completing a questionnaire. The objectives of the pilot evaluations are mainly to assess the feasibility, usability, acceptance and functionality of the system and the ability of the potential target user to use the system and receive valuable information from it to help them address the complex needs of elderly people. The results of the assessment will be taken into account during further product development.

  • Emission profile of butan-2-one oxime from commercially available neutral silicone sealant
    • Krzysztof Klewicz
    • Mariusz Marć
    • Bożena Zabiegała
    2020 Pełny tekst MICROCHEMICAL JOURNAL

    The paper presents results of research on emission profile of butan-2-one oxime (methyl ethyl ketoxime, MEKO) released from two types of commercially available neutral silicone sealants: silicone type ‘S’ and silicone type ‘T’. To determine the emissions from silicone samples, the system consists of a stationary emission chamber, and the thermal desorption-gas chromatography-mass spectrometry system was applied. First, the research aimed to describe the emission profile of butan-2-one oxime considering different methods of application of silicone caulk: separate strips, merged strips, and dotted. Silicone sealant was applied in these three different ways to produce varying surfaces. As a result, significant differences in the emission profile were observed for the different methods of silicone application. The greatest difference in the emission rate was found to be between those of the dot shape and those of the separate strips; the emission rate was approximately five times smaller for dot shape. Moreover, the studies focused on quantitative emissions of butan-2-one oxime over a set time period. The research results indicate that, in the emission process of butan-2-oxime from a neutral silicone sealant, there are three main stages of emission. The first stage is dynamic emission, occurring during the first few days after application. The second stage is declining emission, and the third stage is stable residual emission. Between the first and third stages, the amounts of emitted oxime differ significantly. The difference in the emissions of butan-2-one oxime between the first and last stages of emission ranged from factors of 100 to 1000.

  • Emissions of selected monoaromatic hydrocarbons as a factor affecting the removal of single-use polymer barbecue and kitchen utensils from everyday use
    • Mariusz Marć
    2020 Pełny tekst SCIENCE OF THE TOTAL ENVIRONMENT

    The main focus of this study is the emission of monoaromatic hydrocarbons because these are the preliminary factors of potential solvent and monomer residues present in single-use plastic barbecue and kitchen utensils comprising polystyrene, polypropylene, natural cellulose, and biodegradable polymers intended for use with hot meal or beverages. Herein, the emissions of monoaromatic hydrocarbons (styrene, benzene, toluene, ethylbenzene, and xylene compounds and the total volatile organic compounds (TVOC)) fromnine types of disposable plastic utensils are reported. Seventy two samples of single-use plastic utensilswere conditioned at 40 and 80 °C using a stationary emission microchamber system. The average TVOC released from the studied polystyrene, polypropylene, and natural or biodegradable utensils were (2.3 ± 1.3), (1.01 ± 0.15), and (0.48 ± 0.37) μg g−1, respectively, at 40 °C and (11.1±1.2), (46.1±9.5), and (5.5±1.1) μg g−1, respectively, at 80 °C. Significant emissions of styrene (ranged from 3.5 up to 15.3 × 103 ng∙g−1), toluene (from 2.8 up to 0.53 × 103 ng∙g−1), and ethylbenzene (from3.7 up to 5.7 × 103 ng∙g−1) fromthe studied sampleswere observed, especially at 80 °C. Thus, elevated temperatures increase the potential emission of solvent and monomer residues fromplastics and could affect the quality of consumed meals or beverages, such as taste. Additionally, to determine the possible interactions between the measured chemical compounds in the plastic utensils, the Pearson's correlation coefficients were calculated.

  • Employee Commitment Matters for CSR Practice, Reputation and Corporate Brand Performance—European Model
    • Wioleta Kucharska
    2020 Pełny tekst Sustainability

    So far, there have been no studies that explore how employee brand commitment moderates CSR practice outcomes. Employee brand commitment is often claimed as a focal input and output of the CSR. So, it means that it shapes CSR conditions. Then, it is a moderator. This study aims to verify it. Besides, commitment exists in many forms and can be achieved in many ways. Hence the question, if employees are committed to the brand, then how does it affect the outcomes of social responsibility practices such as corporate reputation or brand performance? This study analyzed a sample of 282 cases from the construction industry in Europe, using SPSS Amos and the PROCESS macro, to reveal the strong alignment of an excellent level of all three: CSR practice, corporate brand reputation, employee brand commitment. Still, it also shows that the high level of CSR practice may leverage corporate brand reputation even though employees are not brand committed. It exposes how meaningful the excellent level of CSR practice is. Moreover, the study also reveals that the lack of employee brand commitment may jeopardize reputation. So, the simplest way to achieve sustainability of brand performance is to keep employee brand commitment and CSR practice at the highest possible level to secure corporate brand reputation, which is a strong mediator between CSR practice and brand performance. The people are the company. So, in light of the study findings, it is clear that the future of corporate brands is in employees’ hands. Thus, companies should focus on improving employee commitment to achieve better corporate socialresponsibility practice outcomes. Moreover, the findings in this study present evidence supporting the importance of internal branding. This is the first study that has explored how employee brand commitment moderates CSR outcomes in a national context.

  • Employing Subjective Tests and Deep Learning for Discovering the Relationship between Personality Types and Preferred Music Genres
    • Aleksandra Dorochowicz
    • Adam Kurowski
    • Bożena Kostek
    2020 Pełny tekst Electronics

    The purpose of this research is two-fold: (a) to explore the relationship between the listeners’ personality trait, i.e., extraverts and introverts and their preferred music genres, and (b) to predict the personality trait of potential listeners on the basis of a musical excerpt by employing several classification algorithms. We assume that this may help match songs according to the listener’s personality in social music networks. First, an Internet survey was built, in which the respondents identify themselves as extraverts or introverts according to the given definitions. Their task was to listen to music excerpts that belong to several music genres and choose the ones they like. Next, music samples were parameterized. Two parametrization schemes were employed for that purpose, i.e., low-level MIRtoolbox parameters (MIRTbx) and variational autoencoder neural network-based, which automatically extract parameters of musical excerpts. The prediction of a personality type was performed employing four baseline algorithms, i.e., support vector machine (SVM), k-nearest neighbors (k-NN), random forest (RF), and naïve Bayes (NB). The best results were obtained by the SVM classifier. The results of these analyses led to the conclusion that musical excerpt features derived from the autoencoder were, in general, more likely to carry useful information associated with the personality of the listeners than the low-level parameters derived from the signal analysis. We also found that training of the autoencoders on sets of musical pieces which contain genres other than ones employed in the subjective tests did not affect the accuracy of the classifiers predicting the personalities of the survey participants.

  • ENERGY ANALYSIS OF THE PROPULSION SHAFT FATIGUE PROCESS IN A ROTATING MECHANICAL SYSTEM PART II IDENTIFICATION STUDIES – DEVELOPING THE FATIGUE DURABILITY MODEL OF A DRIVE SHAFT
    • Zbigniew Korczewski
    • Konrad Marszałkowski
    2020 Pełny tekst Polish Maritime Research

    The article presents a continuation of research carried out concerning identification of energy consequences of mechanical fatigue within a propeller shaft in a rotating mechanical system, while working under conditions of the loss of the required alignment of shaft lines. Experimental research was carried out on a physical model reflecting a full-sized real object: i.e., the propulsion system of the ship. It is proven, by means of an active experiment, that changes in propeller shaft deflection are reflected in the amount of dissipated kinetic energy of masses in rotational motion and the accumulated internal energy in its construction material. Adoption of a high-cycle fatigue syndrome, consisting of diagnostic symptoms determined from the action of the propeller shaft associated with the transformation of mechanical energy into work and heat, as well as with the generation of mechanical vibrations and elastic waves of acoustic emission, is proposed. To assess the diagnostic information quantity brought about by the defined features of propeller shaft fatigue, an experimental research program was developed and implemented, in which two statistical hypotheses are verified: the significance of the impact of the values enforcing the fatigue process, presented in the first part of the article, and the adequacy of the regression equation describing the fatigue durability of the propeller shaft in the energy aspect, constituting the second part of the article. This finally gives us the opportunity, after the appropriate translation of the model test results into full-sized real objects, to develop a methodology to diagnose marine propeller shaft fatigue in operating conditions. The third part of the article is devoted to this issue

  • Energy neutrality versus carbon footprint minimization in municipal wastewater treatment plants
    • Mojtaba Maktabifard
    • Ewa Zaborowska
    • Jacek Mąkinia
    2020 Pełny tekst BIORESOURCE TECHNOLOGY

    This work aimed to compare the carbon footprint (CF) of six full-scale wastewater treatment plants (WWTPs). The CF was estimated in the range of 23–100 kg CO2e per population equivalent. In the total CF, the direct emissions held the highest share (62–74%) for the plants with energy recovery from biogas. In the plants depending entirely on the power grid, the indirect emissions due to energy consumption dominated the total CF (69–72%). The estimated CF was found highly sensitive towards the choice of N2O emission factors. A dual effect of external substrates co-digestion on the CF has been presented. After co-digestion, the overall CF decreased by 7% while increasing the biogas production by 17%. While applying the empirical model, the level of energy neutrality was strongly related to the ratio of the indirect to direct emissions.

  • Energy Yield Generated by a Small Building Integrated Photovoltaic Installation
    • Ewa Klugmann-Radziemska
    • Małgorzata Rudnicka
    2020 Pełny tekst Ecological Chemistry and Engineering S - Chemia i Inżynieria Ekologiczna S

    In the recent years photovoltaic (PV) industry has experienced a major growth, caused by the ever present annual decrease in module production prices and the expanding awareness of the general public in terms of renewable energy. There are numerous ways to implement PV modules as an additional energy source for a building, be it mounted on the rooftop, or building integrated (BIPV). An analysis of BIPV consisting of 8 modules with the power of 250 Wp each was carried out for the building of the Chemistry Faculty of Gdansk University of Technology (GUT). It included monthly irradiance and energy generation values and compared them to data obtained by the means of PV-GIS system, after inserting site specific coordinates. Additional research on the same type of a single module with the power of 270 Wp was conducted to provide more insight in this matter. A comprehensible analysis allows for defining a final conclusion for the decrease in energy yield for GUT BIPV installation. Data outputs are lower than expected based on PV-GIS values, as for the most time the facade mounted PV system experiences partial soft shading from t he nearby park. Furthermore, it is not located directly facing south, but rather south-east which does not prompt ideal working conditions.

  • Engendering responsibility in architecture students through real planning for a tram depot in Gdańsk
    • Justyna Borucka
    • Piotr Czyż
    • Wojciech Targowski
    2020 Pełny tekst World Transactions on Engineering and Technology Education

    Apart from technical competencies, the profession of architect requires specific social competencies: understanding the user’s needs, ability to diagnose social problems, negotiating and understanding the impact of construction investments on society and the environment. The architect plays a significant role in the collective effort to create spatial order. This is why it is important to include these social competencies in the curricula of architectural studies. It should be required that students of architecture actively engage in real design processes to develop competencies underpinning professional responsibility and cooperation. Presented in this article is an experimental course. Enrolled in the course were students engaged in preparatory work on planning documents prepared for the city of Gdańsk. Participation in real activities, with real partners and problems, engenders the students’ sense of responsibility. Attaining that is crucial in the future work of an architect.

  • Enhanced Activity of P4503A4 and UGT1A10 Induced by Acridinone Derivatives C-1305 and C-1311 in MCF-7 and HCT116 Cancer Cells: Consequences for the Drugs’ Cytotoxicity, Metabolism and Cellular Response
    • Monika Pawłowska
    • Anna Kwaśniewska
    • Zofia Mazerska
    • Ewa Augustin
    2020 Pełny tekst INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    Activity modulation of drug metabolism enzymes can change the biotransformation of chemotherapeutics and cellular responses induced by them. As a result, drug-drug interactions can be modified. Acridinone derivatives, represented here by C-1305 and C-1311, are potent anticancer drugs. Previous studies in non-cellular systems showed that they are mechanism-based inhibitors of cytochrome P4503A4 and undergo glucuronidation via UDP-glucuronosyltranspherase 1A10 isoenzyme (UGT1A10). Therefore, we investigated the potency of these compounds to modulate P4503A4 and UGT1A10 activity in breast MCF-7 and colon HCT116 cancer cells and their influence on cytotoxicity and cellular response in cells with dierent expression levels of studied isoenzymes. We show that C-1305 and C-1311 are inducers of not only P4503A4 but also UGT1A10 activity. MCF-7 and HCT116 cells with high P4503A4 activity are more sensitive to acridinone derivatives and undergo apoptosis/necrosis to a greater extent. UGT1A10 was demonstrated to be responsible for C-1305 and C-1311 glucuronidation in cancer cells and glucuronide products were excreted outside the cell very fast. Finally, we show that glucuronidation of C-1305 antitumor agent enhances its pro-apoptotic properties in HCT116 cells, while the cytotoxicity and cellular response induced by C-1311 did not change after drug glucuronidation in both cell lines.

  • Enhanced Charge Storage Mechanism And Long-Term Cycling Stability In Diamondized Titania Nanocomposite Supercapacitors Operating In Aqueous Electrolytes
    • Robert Bogdanowicz
    • Anna Dettlaff
    • Franciszek Skiba
    • Konrad Trzciński
    • Mariusz Szkoda
    • Michał Sobaszek
    • Mateusz Ficek
    • Bartłomiej Dec
    • Łukasz Macewicz
    • Dongsheng Geng
    • Arkadiusz Ignaczak
    • Jacek Ryl
    2020 Pełny tekst Journal of Physical Chemistry C

    The long cycle life stability jointly with high energy density are limiting broader feasible applications of supercapacitors. The novel diamondized titania nanocomposite supercapacitors deliver high power and energy densities along with high capacitance retention rates. Supercapacitor electrodes were fabricated utilizing a combination of Ti anodization followed by chemical vapor deposition resulting in simultaneous growth of complex BDD/TiC interface. The first-principles simulations along with extended molecular investigations conducted by BF-TEM and HR-SEM revealed that capacitive phenomena are delivered by nanoporous, multi-faceted, and substoichiometric TiC, forming clusters at the lateral surfaces of titania nanotubes. Next, TiC mechanical stability and effective charge transfer electrode-electrolyte are efficiently provided by highly conductive although discontinuous BDD overlayer. The assembled two-electrode supercapacitor devices exhibited capacitance 15 mF cm−2, which were stable at 0.1 V s−1 scan rate in various neutral aqueous electrolytes. The composite TiO2NT-BDD supercapacitors showed outstanding long-term cycling stability with capacitance retention of 93% after 100,000 chronopotentiometry cycles verified by post-aging cyclic voltammetry tests. In parallel, the energy and power density calculated at a current density of 3 A g-1 achieved levels as high as 14.74 Wh kg-1 and 24.68 kW kg-1, revealing the superior performance of the assembled devices compared to recently reported supercapacitors.

  • Enhanced interfacial and mechanical performance of styrene-butadiene rubber/silica composites compatibilized by soybean oil derived silanized plasticization
    • Adeel Hassan
    • Krzysztof Formela
    • Shifeng Wang
    2020 COMPOSITES SCIENCE AND TECHNOLOGY

    Silanized plasticizer (SP) was chemically derived and synthesized from soybean oil (SBO) co-vulcanized with bis-(3-(triethoxysilyl)-propyl) tetrasulfide (TESPT) by using the sulfur-accelerated curing system. SP extended styrene-butadiene rubber (SBR)/silica composites have been studied for their improved filler dispersion through coupling interaction at the SBR/silica interface. The effect of SP on cross-link density, thermal, static and dynamic mechanical properties of SBR composites related to the tire performance, were investigated. The results revealed that SP enhanced tensile strength, modulus, and hardness of the composites due to an improved matrix-filler interaction together with an excellent control over oil migration. Further improvement was observed for SP with increasing TESPT content, what was related to the increase in cross-linking density, and bound rubber content of the composite materials. Morphology and reduced Payne effect confirmed the silica particles have an even dispersion throughout the SBR matrix. The dynamic curves indicated the highest efficacy for wet and dry traction performances of SP extended SBR composites comparing to unmodified reference sample. This research provided the effect of SP as a novel reactive bio-plasticizer to improve the performance of SBR/silica composites for green tire manufacture, while being eco-friendly.

  • Enhanced Mobility and Large Linear Nonsaturating Magnetoresistance in the Magnetically Ordered States of TmNiC2
    • Kamil Kolincio
    • Marta Roman
    • Tomasz Klimczuk
    2020 Pełny tekst PHYSICAL REVIEW LETTERS

    We have studied the magnetic, magnetotransport, and galvanomagnetic properties of TmNiC2. We find that the antiferromagnetic and field induced metamagnetic and ferromagnetic orderings do not suppress the charge density wave. The persistence of Fermi surface pockets, open as a result of imperfect nesting accompanying the Peierls transition, results in an electronic carriers mobility of the order of 4 × 103 cm2 V−1 s−1 in ferromagnetic state, without any signatures for a significant deterioration of nesting properties. This is independently evidenced by high, nonsaturating linear magnetoresistance reaching 440% at T ¼ 2 K and an analysis of the Hall conductivity. We thus demonstrate that, the coexistence of charge density wave and magnetism provides an alternative route to maintain high electronic mobility in the magnetically ordered state.

  • Enhanced Photoelectrocatalytical Performance of Inorganic-Inorganic Hybrid Consisting BiVO4, V2O5, and Cobalt Hexacyanocobaltate as a Perspective Photoanode for Water Splitting
    • Konrad Trzciński
    • Mariusz Szkoda
    • Sawczak Mirosław
    • Anna Lisowska-Oleksiak
    2020 Pełny tekst Electrocatalysis

    Thin layers of BiVO4/V2O5 were prepared on FTO substrates using pulsed laser deposition technique. The method of cobalt hexacyanocobaltate (Cohcc) synthesis on the BiVO4/V2O5 photoanodes consists of cobalt deposition followed by electrochemical oxidation of metallic Co in K3[Co(CN)6] aqueous electrolyte. The modified electrodes were tested as photoanodes for water oxidation under simulated sunlight irradiation. Deposited films were characterized using UV-Vis spectroscopy, Raman spectroscopy, and scanning electron microscopy. Since the V2O5 is characterized by a narrower energy bandgap than BiVO4, the presence of V2O5 shifts absorption edge (ΔE = ~0.25 eV) of modified films towards lower energies enabling the conversion of a wider range of solar radiation. The formation of heterojunction increases photocurrent of water oxidation measured at 1.2 V vs Ag/ AgCl (3 M KCl) to over 1 mA cm-2, while bare BiVO4 and V2O5 exhibit 0.37 and 0.08 mA cm-2, respectively. On the other hand, the modification of obtained layers with Cohcc shifts onset potential of photocurrent generation into a cathodic direction. As a result, the photocurrent enhancement at a wide range of applied potential was achieved.

  • Enhanced trap-assisted recombination in organic semiconductors
    • Jędrzej Szmytkowski
    2020 Pełny tekst SOLID STATE COMMUNICATIONS

    An analytical model to describe the interaction of excitons and charge transfer states with deep traps is formulated for the case of molecular materials. Here, we have considered the influence of a trap-assisted recombination on this phenomenon. The final expression for the effective recombination rate has been derived from the Shockley–Read–Hall theory and kinetic equations which characterize different photophysical processes. The presented model can be applied in modeling of organic photovoltaic devices.

  • Enhanced Visible Light Active WO3 Thin Films Toward Air Purification: Effect of the Synthesis Conditions
    • Anna Pancielejko
    • Marta Rzepnikowska
    • Adriana Zaleska-Medynska
    • Justyna Łuczak
    • Paweł Mazierski
    2020 Pełny tekst Materials

    Taking into consideration, our current environmental situation in the world people should face with growing problem of air and water pollution. Heterogeneous photocatalysis is highly promising tool to improve both, air and water quality through decomposition/mineralization of contaminations directly into harmless CO2 and H2O under ambient conditions. In this contribution we focused on the synthesis of self-assembly WO3 thin films via an electrochemical approach in the aqueous electrolyte containing fluoride ions towards air purifications. The effect of preparation conditions such as applied potential (10 – 50 V), anodization time (15 – 120 minutes), concentration of H2SO4 (0.5 – 1.5 M) and NaF (0.1 – 1.0 wt.%) on the morphology, photocurrent response and photocatalytic activity addressed to removal of air pollutant in the presence of as-prepared WO3 samples were thoroughly examined and presented. The results revealed the growth of nanoplatelets and their gradual transformation into flower-like structure. The oxide layers and platelets thickness of the WO3 samples were found to be proportionally related with the synthesis conditions. The photocatalytic ability towards air purification was evaluated by degradation of toluene from air mixture using low-powered LEDs as an irradiation source (λmax = 415 nm). The highest photoactivity was achieved in presence of the sample which possessed well-ordered, regular shape and repeatable distribution of flower buds (100% of degradation). The results have confirmed that the oxide layer thickness of the anodic WO3 significantly affected the photocatalytic activity, which increased with the increasing thickness of WO3 (to 1.05 μm) and then had a down trend. The photocurrent response evidenced that well-organized sample had the highest ability in photocurrent generation under UV-Vis and Vis irradiation. Finally, a possible growth mechanism of WO3 NFs was also discussed.

  • Enhanced-Performance Circularly Polarized MIMO Antenna with Polarization/Pattern Diversity
    • Ubaid Ullah
    • Ismail Mabrouk
    • Sławomir Kozieł
    2020 Pełny tekst IEEE Access

    Design of a compact wideband circularly polarized (CP) multiple-input multiple-output (MIMO) antenna with polarization diversity is proposed and characterized for off-body communication. The antenna is based on a simple coplanar waveguide (CPW)-fed monopole extension of the microstrip line. The orthogonal field components required by CP are induced using a simply modified right/left side ground plane. In particular, a stub extending from the ground plane along the length of the microstrip line generates the vertical component, whereas the current along the width of the ground plane contributes to the horizontal components. To obtain a unidirectional radiation pattern in the off-body direction and to reduce the sensitivity to the human body loading effects, a flat reflector printed on a high permittivity flexible substrate is applied. The simple topology of the antenna can be described by a few adjustable parameters, which facilitates its EM design closure. Prior to the experimental validation in the free space and on the body, the antenna is optimized at the full-wave level of description for all major performance figures. The overall footprint of the antenna radiator is only Ls × Ws = 0.24 λ0 × 0.64 λ0 = 0.15 λ02. The proposed MIMO antenna features |S11|≤ -10 dB, average isolation |S21|≤ -22 dB, and axial ratio (AR)and axial ratio 3 dB from 5.2 GHz to 6.3 GHz with 100% bandwidth overlap between the impedance and axial ratio bandwidths. The envelope correlation coefficient (ECC) is less than 0.004 with the maximum diversity gain (DG) of approximately 9.99 dB. Moreover, the antenna maintains a high efficiency of up to 90% when loaded on the body, and a low specific absorption rate (SAR).

  • Enhancement of the Magnetic Coupling in Exfoliated CrCl 3 Crystals Observed by Low‐Temperature Magnetic Force Microscopy and X‐ray Magnetic Circular Dichroism
    • Michele Serri
    • Giuseppe Cucinotta
    • Lorenzo Poggini
    • Giulia Serrano
    • Philippe Sainctavit
    • Judyta Strychalska-Nowak
    • Antonio Politano
    • Francesco Bonaccorso
    • Andrea Caneschi
    • Robert J. Cava
    • Roberta Sessoli
    • Luca Ottaviano
    • Tomasz Klimczuk
    • Vittorio Pellegrini
    • Matteo Mannini
    2020 ADVANCED MATERIALS

    Magnetic crystals formed by 2D layers interacting by weak van der Waals forces are currently a hot research topic. When these crystals are thinned to nanometric size, they can manifest strikingly different magnetic behavior compared to the bulk form. This can be the result of, for example, quantum electronic confinement effects, the presence of defects, or pinning of the crystallographic structure in metastable phases induced by the exfoliation process. In this work, an investigation of the magnetism of micromechanically cleaved CrCl3 flakes with thickness >10 nm is performed. These flakes are characterized by superconducting quantum interference device magnetometry, surface-sensitive X-ray magnetic circular dichroism, and spatially resolved magnetic force microscopy. The results highlight an enhancement of the CrCl3 antiferromagnetic interlayer interaction that appears to be independent of the flake size when the thickness is tens of nanometers. The estimated exchange field is 9 kOe, representing an increase of ≈900% compared to the one of the bulk crystals. This effect can be attributed to the pinning of the high-temperature monoclinic structure, as recently suggested by polarized Raman spectroscopy investigations in thin (8–35 nm) CrCl3 flakes.

  • Enhancing Availability for Critical Services
    • Teresa Gomes
    • Lúcia Martins
    • Rita Girão-Silva
    • David Tipper
    • Alija Pašić
    • Balázs Vass
    • Luís Garrote
    • Urbano J. Nunes
    • Martin Zachariasen
    • Jacek Rak
    2020

    Traditional approaches to provide classes of resilient service take the physical network availability as an input and then deploy redundancy and restoration techniques at various layers, often without full knowledge of mappings between layers. This makes it hard (and often inefficient) to ensure the high availability required by critical services which are typically a small fraction of the total traffic. Here, the innovative technique of embedding a higher availability substructure, designated the spine, into the network at the physical layer, is explored. In the spine-based approach, it is considered that high availability must begin at the physical level and then must be reinforced in upper layers. A recent disaster-resilience framework, named Framework for Disaster Resilience, which incorporates reliable network design (i.e. using the spine), disaster failure modelling and protection routing to improve the availability of critical services is discussed. Next, a proposal to select network links for availability upgrade to ensure high availability is presented. This is followed by a study assuming that if disaster-prone areas are known, they can be represented as obstacles which should be avoided when deploying the physical backbone of a communications network. Hence, a heuristic for a minimum-cost Euclidean Steiner tree taking into account the presence of soft obstacles is presented.

  • Enhancing Product Manufacturing through Smart Virtual Product Development (SVPD) for Industry 4.0
    • Muhammad Ahmed
    • Cesar Sanin
    • Edward Szczerbicki
    2020 Pełny tekst CYBERNETICS AND SYSTEMS

    ABSTRACT This paper proposes the Smart Virtual Product Development (SVPD) system, which enhances the industrial product manufacturing processes. The proposed system comprises of three main modules: design knowledge management (DKM), manufacturing capability analysis and process planning (MCAPP), and product inspection planning (PIP). Smart virtual product development system collects, stores, and uses experiential knowledge from formal decisional events in the form of set of experience (SOE). This research explains the working mechanism of MCAPP module, and shows how manufacturing knowledge of similar products having some common features and functions is used to enrich the manufacturing process. First, the basic description and principles of the approach are introduced, then the prototype version of the system is developed and tested for manufacturing capability and process planning (MCAPP) module for the case study, which verifies the feasibility of the proposed approach. The presented system successfully supports smart manufacturing, and can play a vital role in Industry 4.0.

  • Enhancing women’s engagement in economic activities through information and communication technology deployment: evidence from Central–Eastern European countries
    • Ewa Lechman
    • Magdalena Popowska
    2020 Pełny tekst Gender, Technology and Development

    This study takes a macro perspective to examine the associations between the economic deployment of information and communication technology (ICT), women’s labor market participation, and economic growth in Central–Eastern European countries between 1990 and 2017. We use data extracted from World Bank Development Indicators, World Development Reports, and the World Telecommunication/ICT Indicators Database. Our methodological framework combines time trends, graphical non-parametric analysis, and panel vector-autoregressive models. The findings reveal significant relationships between ICT and women’s economic activity. Panel vector-auto-regression model estimates and Granger causality tests indicate causal relationships between ICT, economic growth, and female youth employment but not between the remaining pairs of variables.

  • Enriched buckling for beam-lattice metamaterials
    • Victor Eremeev
    • Emilio Turco
    2020 Pełny tekst MECHANICS RESEARCH COMMUNICATIONS

    We discuss two examples of beam-lattice metamaterials which show attractive mechanical properties concerning their enriched buckling. The first one considers pantographic beams and the nonlinear solution is traced out numerically on the base of a Hencky’s model and an algorithm based on Riks’ arc-length scheme. The second one concerns a beam-lattice with sliders and the nonlinear solution is discussed in analytic way and, finally, extended to the case of uniform in-plane tension. Some concluding remarks draw possible future developments and challenges.

  • Entrepreneurship nests in a polish edge city
    • Justyna Martyniuk-Pęczek
    • Olga Martyniuk
    • Tomasz Parteka
    2020

    The last two decades in Poland have been a period of both a dynamic development of the small and medium-sized enterprise sector and a transformation of the city surrounding territories. This development began during the economy transformation after 1989. Population migration and movement of economic entities away from central cities resulted in development of territorial structures within some Polish suburban areas, defined as entrepreneurship nests. This may mean that economic activity of these inhabitants may be higher than that of the central-city residents. What is more, it seems to be a distinguishing feature of the Polish suburban areas, compared to the suburbanization areas of other Western European countries or the United States. The topic of the relationship between suburbanization processes and the development of small and medium-sized enterprise (SME) sector derives from the Authors’ work on a scientific project entitled Creation of entrepreneurship nests in the Tri-City Metropolitan Area. Analysis of the spatial and economic relations of the SME sector, financed by the National Science Center1 – contract number UMO-2013/09/B/HS4/01175.

  • Entrepreneurship Today: Selected Aspects
    • Magdalena Byczkowska
    • Zhanna Poplavska
    • Sofiya Komarynets
    • Yulia Stukalina
    • Anna Majzel
    • Krzysztof Zięba
    2020 Pełny tekst

    At its very beginning, entrepreneurship was a purely economic notion. However, this growing interest in entrepreneurship-related problems prompted other sciences to participate in explaining the entrepreneurship phenomenon. Nowadays, entrepreneurship is analyzed through multiple theoretical lenses of economics, management, psychology, sociology – just to name a few. Therefore, it would be difficult to find a notion that could be equally diverse, complex and multifaceted. As a result, any book on entrepreneurship is in some sense fragmentary, based on the same aspects, inclusive of some problems, but at the same time exclusive of others. This book presents just a few interesting features linked to entrepreneurship in the modern economy. The first chapter presents some general considerations on entrepreneurship, its definitions, ways to measure the level of entrepreneurial activities in a country, as well as the role of human resources and innovations. Some empirical data is presented there, positioning Poland within the broader European context. In the second chapter, the view on entrepreneurship is broadened by discussing the concept of nascent entrepreneurship, its birth and further development. Based on several theoretical and empirical papers, the main strands of research into nascent entrepreneurship are presented. The broadening of the scope is continued in the next chapter which emphasizes the transition from a managed economy to an entrepreneurial economy. This transition amplifies the importance of so-called entrepreneurialism, defined as a constant operation in an entrepreneurial mode. Entrepreneurialism at modern universities allows creating new models of support for education and research activities which are discussed in this chapter. In the fourth chapter, the focus moves more towards the characteristics of modern economies, where skills and knowledge become more and more vital for economic growth. One of the main ways of knowledge diffusion in our globalized world are Foreign Direct Investments (FDIs). Empirical data in this chapter comes from one of the Western regions of Poland. The last chapter analyses the impact of economic and institutional environment on the activity of enterprises in Poland and Ukraine. Those neighbouring countries share a lot of common history, but in terms of economic situation, they currently differ significantly. This is what makes a comparative analysis between those two countries interesting and instructive.

  • Equivalent Single Layer Models in Free Vibration Analysis of Laminated Multi-Layered Plates
    • Ireneusz Kreja
    • Agnieszka Sabik
    2020 Pełny tekst International Journal of Structural Stability and Dynamics

    The performance of selected equivalent single-layer (ESL) models is evaluated within several classical benchmark tests for small amplitude free vibration analysis of multi-layered plates. The authors elaborated their own Finite Element software based on the first-order shear deformation (FOSD) theory with some modifications incorporated including a correction of the transverse shear stiffness and an application of zigzag type functions. Seven different ESL models were considered in the study; beside the classical FOSD model, there were three FOSD models with various transverse shear corrections and three ESL models enhanced by the application of zigzag functions and based on Reissner’s Mixed Variational Theorem.

  • Escherichia coli Strains with Virulent Factors Typical for Uropathogens were Isolated from Sinuses from Patients with Chronic Rhinosinusitis—Case Report
    • Beata Krawczyk
    • Michał Michalik
    • Magdalena Fordon
    • Magdalena Wysocka
    • Alfred Samet
    • Bogdan Nowicki
    2020 Pełny tekst Pathogens

    Escherichia coli were isolated from three patients with chronic rhinosinusitis (CRS) by intraoperative sinus tissue biopsy. Taking into account the unusual replicative niche and previous treatment failures, it was decided to focus on the virulence and drug resistance of these bacteria. The strains turned out to be multi-sensitive, but the rich virulence factors profile of bacteria typical for phylogenetic group B2 deserved attention. Tests were carried out for the presence of 32 genes using the PCR method. Particularly noteworthy are the toxins Cnf-1, HlyA, Usp—an extensive iron uptake system (enterobactin, salmochelin, yersiniabactin and outer membrane hemin receptor ChuA)—SPATE autotransporters such as vat and pic, Ag43 autoaggregative protein—important for biofilm formation—and TosA/B which enhance the fitness of E.coli. All these virulence factors are identified predominantly in UPEC strains and provide a fitness advantage during colonization of the sinuses. Patients with CRS should be asked for past or present UTI. The specific virulence factors of E. coli that facilitate the colonization of the GI tract and urinary tract may also favor the colonization of a new ecological niche (sinuses) as a result of microbial imbalance or dysbiosis.

  • ESPAR Antenna-Based WSN Node With DoA Estimation Capability
    • Mateusz Groth
    • Mateusz Rzymowski
    • Krzysztof Nyka
    • Łukasz Kulas
    2020 Pełny tekst IEEE Access

    In this paper, we present a low-cost energy-efficient electronically steerable parasitic array radiator (ESPAR) antenna-based wireless sensor network (WSN) node designed for IEEE 802.15.4 standard that is capable of performing direction of arrival (DoA) estimation in real-life outdoor environments. To this end, we propose the WSN node architecture, design and realization that utilizes NXP JN5168 radio frequency (RF) wireless transceiver and a microcontroller integrated with ESPAR antenna beam-switching circuits. To incorporate DoA estimation capability into the developed single-board WSN node, power-pattern cross-correlation (PPCC) algorithm, that relies solely on received signal strength (RSS) values measured by the transceiver at the antenna output for every considered directional antenna radiation pattern, has been adapted and implemented in a simple microcontroller embedded within NXP JN5168 integrated circuit. Measurements conducted in an outdoor environment show that the proposed low-cost WSN node can successfully provide DoA estimation results, which may be used to enhance WSN capabilities in practical applications. The obtained root mean square (RMS) DoA estimation errors are 7.91°, 6.58° and 9.47° for distances between WSN nodes equal to 3 m , 5 m and 10 m respectively.

  • Esselunga
    • Luciano Segreto
    2020

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  • Estimating the Cost of Cybersecurity Activities with CAsPeA: A Case Study and Comparative Analysis
    • Rafał Leszczyna
    • Adrian Litwin
    2020 Pełny tekst

    Contemporary approaches to the estimation of cybersecurity costs in organisations tend to focus on the cost of incidents or technological investments. However, there are other, less transparent costs related to cybersecurity management that need to be properly recognised in order to get a complete picture. These costs are associated with everyday activities and the time spent by employees on cybersecurity-related actions. Such costs constitute a substantial component of cybersecurity expenditures, but because they become evident only during scrupulous analyses, often they are neglected. This paper presents new developments on CAsPeA - a method which enables estimating the cost of these activities based on a model derived from the Activity-Based Costing (ABC) and the NIST SP 800-53 guidelines. The application of the method is illustrated by a case study of a civil engineering enterprise. The method's evaluation based on comparative analysis in respect to SQUARE is described.