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  • 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.

  • Estimating the parameter of inequality aversion on the basis of a parametric distribution of incomes
    • Stanisław Kot
    2020 Pełny tekst EQUILIBRIUM Quarterly Journal of Economics and Economic Policy

    Research background: In applied welfare economics, the constant relative inequality aversion function is routinely used as the model of a social decisionmaker’s or a society’s preferences over income distributions. This function is entirely determined by the parameter, ε, of inequality aversion. However, there is no authoritative answer to the question of what the range of ε an analyst should select for empirical work. Purpose of the article: The aim of this paper is elaborating the method of deriving ε from a parametric distribution of disposable incomes. Methods: We assume that households’ disposable incomes obey the generalised beta distribution of the second kind GB2(a,b,p,q). We have proved that, under this assumption, the social welfare function exists if and only if ε belongs to (0,ap+1) interval. The midpoint εmid of this interval specifies the inequality aversion of the median social-decisionmaker. Findings & Value added: The maximum likelihood estimator of εmid has been developed. Inequality aversion for Poland 1998–2015 has been estimated. If inequality is calculated on the basis of disposable incomes, the standard inequality–development relationship might be complemented by inequality aversion. The “augmented” inequality–development relationship reveals new phenomena; for instance, the stage of economic development might matter when assessing the impact of inequality aversion on income inequality.

  • Estimating the uncertainty of discharge coefficient predicted for oblique side weir using Monte Carlo method
    • Ahmed Y. Mohammed
    • Anna Golijanek-Jędrzejczyk
    2020 Pełny tekst FLOW MEASUREMENT AND INSTRUMENTATION

    Side weir is a hydraulic structure, which is used in irrigation systems to divert some water from main to side channel. It is installed at the entrance of the side channel to control and measure passing water into the side channel. Many studies provided side weir water surface profile and coefficient of discharge to measure water discharge diverted into the side channel. These studies dealt with different side weir shapes (rectangular, trapezoidal, triangular and circular), which were installed perpendicular to the flow direction. Recently, some studies dealt with skew side weir, but these studies still need to more investigation. Here we report to investigate oblique side weir theoretically using statistical method to supported other studies in this case. Measurement uncertainty discharge coefficient Cd was obtained by two methods: analytical according to the 'Guide to the expression of uncertainty in measurement' and the Monte Carlo method. The results indicate that all experimental results are consistent with the analytical results. The relative expanded uncertainty of the discharge coefficient Cd does not exceed 2%.

  • Estimation and Prediction of Vertical Deformations of Random Surfaces, Applying the Total Least Squares Collocation Method
    • Zbigniew Wiśniewski
    • Waldemar Kamiński
    2020 Pełny tekst SENSORS

    This paper proposes a method for determining the vertical deformations treated as random fields. It is assumed that the monitored surfaces are subject not only to deterministic deformations, but also to random fluctuations. Furthermore, the existence of random noise coming from surface’s vibrations is also assumed. Such noise disturbs the deformation’s functional models. Surface monitoring with the use of the geodetic levelling network of a free control network class is carried out. Assuming that, in some cases, the control networks are insufficient in surface’s deformation analysis, additional and non–measurable reference points have been provided. The prediction of these points’ displacements and estimation of the free control network points’ displacement are carried out using the collocation method applying the total least squares adjustment. The proposed theoretical solutions were verified by the simulation methods and on the example of a real control network

  • Estimation of Broadband Complex Permeability Using SIW Cavity-Based Multimodal Approach
    • Nilesh K. Tiwari
    • Abhishek Jha
    • Surya P. Singh
    • M. Jaleel Akhtar
    2020 Pełny tekst IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT

    In this article, an attractive multimodal substrate integrated waveguide (SIW) based methodology is presented for the characterization of magnetic materials in the broadband microwave frequency. The proposed approach employs a modified feed under-coupled SIW cavity instead of conventional feed over-coupled multiple SIW cavities; it uses the modified closedform expression, developed from the first principle to consider the effect of finite sample dimensions, and mode-specific sinusoidal field variations, which were not considered before for magnetic testing using the over-coupled SIW cavity and conventional formulations. The metallic cavity borne approximations i.e., very small frequency shift for the imaginary part calculation, and very high Q-factor for the real permeability estimation are also relaxed in the modified formulations. The proposed technique is numerically verified using the full-wave electromagnetic (EM) simulator for several dispersive and nondispersive standard samples; thereafter, it is validated for the estimation of complex permeability of synthesized dispersive magnetic composites. It can characterize the dispersive magnetic composites, where the permeability value varies from paramagnetic to diamagnetic range, with improved accuracy than that of the conventional cavity perturbation approach. The modified formulation provides 34% and 12% better estimation of loss tangent and real permeability, respectively, as compared with the conventional technique. The uncertainty analysis for change in sample volume, sample misalignment, and the possible air gap is also carried out in detail. The proposed scheme typically provides more than 92% and 84% accuracy in the measured values of real permeability and loss tangent data, respectively, for various synthesized magnetic samples in broadband of microwave frequency (10–22 GHz).

  • Etapy projektowania statków oraz przepływ dokumentacji
    • Dominik Kreft
    2020 Pełny tekst Journal of Polish CIMEEAC

    W artykule przedstawiono główne etapy projektu okrętowego wg. różnych autorów. Następnie opisano zakres prac dla każdego z etapów i przedstawiono je w postaci spirali projektowej. Przedstawiono i opisano również schemat przepływu dokumentacji podczas realizacji projektu klasyfikacyjnego z wyszczególnieniem armatora, biura projektowego, stoczni oraz towarzystwa klasyfikacyjnego.

  • Evaluating calibration and robustness of pedestrian detectors
    • Sebastian Cygert
    • Andrzej Czyżewski
    2020

    In this work robustness and calibration of modern pedestrian detectors are evaluated. Pedestrian detection is a crucial perception com- ponent in autonomous driving and here we study its performance under different image corruptions. Furthermore, we provide analysis of classifi- cation calibration of pedestrian detectors and we show a positive effect of using style-transfer augmentation technique. Our analysis is aimed as a step towards understanding and improving current safety-critical detection systems.

  • Evaluating the Cost of Personnel Activities in Cybersecurity Management: A Case Study
    • Rafał Leszczyna
    2020 Pełny tekst

    The methods of cybersecurity costs' evaluation are inclined towards the cost of incidents or technological acquirements. At the same time, there are other, less visible costs related to cybersecurity that require proper recognition. These costs are associated with the actions and the time spent by employees on activities connected to cybersecurity management. The costs form a considerable component of cybersecurity expenditures, but because they become evident only during scrupulous analyses, often they are disregarded. CAsPeA is a method that enables estimating the costs based on a model derived from the Activity-Based Costing (ABC) and the NIST SP 800-53 guidelines. This paper presents the application of CAsPeA in a steel structures manufacturing company.

  • Evaluation of a company’s image on social media using the Net Sentiment Rate
    • Anna Baj-Rogowska
    2020

    Vast amounts of new types of data are constantly being created as a result of dynamic digitization in all areas of our lives. One of the most important and valuable categories for business is data from social networks such as Facebook. Feedback resulting from the sharing of thoughts and emotions, expressed in comments on various products and services, is becoming the key factor on which modern business is based. This feedback is called sentiment on social media. The sentiment analysis method is used for the mining of polarity views, feelings and emotions from text data with the help of natural language processing (NLP). The fundamental task in this technique is to classify the polarity of opinions into classes such as positive, negative and neutral. This chapter introduces a novel approach to the quantitative measurement of sentiment by means of a created indicator called the Net Sentiment Rate (NSR). The proposed NSR expresses the net sentiment extracted from text data and provides values on a scale from -1 to +1. The Net Sentiment Rate implementation has been verified on large datasets crawled from Facebook in the period from 1 October 2014 to 31 December 2018, for three international companies from the same sector. The created Net Sentiment Rate, together with the classification of its strength, and its verification, constitutes the contribution of this study.

  • Evaluation of Foundation Input Motions Based on Kinematic Interaction Models
    • Tomasz Falborski
    2020

    The present study was designed to demonstrate the importance of baseslab averaging and embedment effects on the foundation-level input motions due to earthquake excitations. Evaluation of foundation-level input motions based on the most commonly adopted kinematic interaction models are presented. In order to conduct this investigation, original records of horizontal accelerations for two casestudy buildings were utilized. Computed foundation-level input motions, in both NS and EW directions, were compared to the actual acceleration-time histories recorded at the foundation levels. The results clearly indicate that incorporating base-slab averaging and embedment effects in seismic analyses can modify the dynamic excitation imposed at the foundation level, and, as a consequence, lead to more accurate structural response due to earthquake ground motions.

  • Evaluation of Immobilization of Selected Peat-Isolated Yeast Strains of the Species Candida albicans and Candida subhashii on the Surface of Artificial Support Materials Used for Biotrickling Filtration
    • Milena Marycz
    • Anna Brillowska-Dąbrowska
    • Jacek Gębicki
    2020 Pełny tekst Processes

    The paper describes the process of n-butanol abatement by unicellular fungi, able to deplete n-butanol content in gas, by using n-butanol as source of carbon. Isolated and identified fungi species Candida albicans and Candida subhashii were subjected to a viability process via assimilation of carbon from hydrophilic and hydrophobic compounds. The isolates, which exhibited the ability to assimilate carbon, were immobilized on four different types of artificial support materials used for biotrickling filtration. Application of optical microscopy, flow cytometry and the tests employing propidium iodide and annexin V revealed viability of the fungi isolated on support materials’ surfaces at the average level of 95%. The proposed method of immobilization and its evaluation appeared to be effective, cheap and fast. Based on performed comparative analyses, it was shown that polyurethane foam and Bialecki rings (25 × 25) could be attractive support materials in biotrickling filtration.

  • Evaluation of Lombard Speech Models in the Context of Speech in Noise Enhancement
    • Grazina Korvel
    • Krzysztof Kąkol
    • Olga Kurasova
    • Bożena Kostek
    2020 Pełny tekst IEEE Access

    The Lombard effect is one of the most well-known effects of noise on speech production. Speech with the Lombard effect is more easily recognizable in noisy environments than normal natural speech. Our previous investigations showed that speech synthesis models might retain Lombard-effect characteristics. In this study, we investigate several speech models, such as harmonic, source-filter, and sinusoidal, applied to Lombard speech in the context of speech enhancement. For this purpose, 100 utterances of natural speech, and 100 with the Lombard effect induced are used. The goal of this study is to check to what extent speech utterances based on these models are recognizable and at what SNR (Signal-to-Noise Ratio) level threshold a particular model stops working. For this purpose, the synthesized models and Lombard speech are mixed with babble speech and street noise recordings with different SNRs. The quality of these models is measured, employing objective indicators as well as subjective tests. Since there is no standardized measure to apply to enhanced speech, an objective measure of assessing the speech quality of a model synthesizing Lombard speech characteristics, based on a feature vector, is proposed. Our approach is then compared with the standardized metric used in telecommunications as well as with subjective test results. The experimental investigations show the superiority of the source-filter models applied to synthesize Lombard speech over other models utilized. Also, the measure proposed correlates more closely with the results of the subjective evaluation than the outcomes from the ITU-T P.563 recommendation. This was checked with a ANOVA statistical analysis.

  • Evaluation of Mechanical Properties of Two-Stage Concrete and Conventional Concrete Using Nondestructive Tests
    • Ali M. Rajabi
    • Farzam Omidimoaf
    • Hakim Abdelgader
    2020 Pełny tekst JOURNAL OF MATERIALS IN CIVIL ENGINEERING

    Different types of concrete mixtures are used as building materials. The manufacturing process of two-stage concrete (TSC) differs from that of conventional concrete. This study investigated conventional mechanical properties derive empirical relations for estimation of the mechanical parameters of TSC and conventional concrete mixtures. TSC was used to prepare 216 specimens and conventional concrete was used to prepare 108 specimens that then were aged for 28 days. Uniaxial compression, Brazilian tensile strength, and point load tests were carried out as destructive testing. Schmidt hammer and ultrasonic pulse velocity tests were carried out as nondestructive testing. The data from testing were categorized as regression or test data. Empirical relations were derived between the parameters for the two types of concrete, and these relations were validated. It was concluded that indirect, nondestructive testing of engineering materials, including concrete, considerably increases the speed and decreases the estimation cost of determining the mechanical parameters. This method can be recommended for estimation of these mechanical parameters.

  • Evaluation of Selected UX Techniques by Product Managers - A Preliminary Survey
    • Jakub Miler
    • Margarita Menjega-Schmidt
    2020

    In this paper we present the results of an opinion survey among 28 IT product managers who evaluated the subjective usefulness of 24 selected UX techniques to 6 IT product management tasks derived from ProdBOK®. We selected the UX techniques based on the literature review and 6 interviews with experienced IT product managers. Based on the survey results, we propose our recommendation of useful techniques for 5 of the 6 studied IT product management tasks. Additionally, we report on the overall perceived usefulness of the UX techniques to all affected IT product management tasks.

  • Evaluation of the Greenness of Analytical Procedures
    • Marta Bystrzanowska
    • Jacek Namieśnik
    • Marek Tobiszewski
    2020

    This contributions introduces the need to develop the methods to evaluate analytical procedures in the light of green analytical chemistry. Green chemistry metrics are not applicable in analytical chemistry because they refer to the mass of product and no product with mass is generated during analytical determination. Analytical greenness evaluations are based on scoring - such as NEMI or Eco-scale or comparative analysis as it is in case of multicriteria decision analysis. Important aspect is also the assessment of solvents and reagents that are applied in analytical procedures for their greening. The different environmental, safety and health parameters are included in the assessments of solvents and reagents. The contribution presents the mechanisms of evaluation and numerous examples. Some results of reagents and solvents assessments are also presented to help analysts in selection greener alternatives.

  • Evaluation of the Influence of Farming Practices and Land Use on Groundwater Resources in a Coastal Multi-Aquifer System in Puck Region (Northern Poland)
    • Adam Szymkiewicz
    • Dawid Potrykus
    • Beata Jaworska-Szulc
    • Anna Gumuła-Kawęcka
    • Małgorzata Pruszkowska-Caceres
    • Lidia Dzierzbicka-Głowacka
    2020 Pełny tekst Water

    This study focuses on the modeling of groundwater flow and nitrate transport in a multi-aquifer hydrosystem in northern Poland, adjacent to Puck Bay (Baltic sea). The main goal was to investigate how changes in land use and farming practices may affect groundwater recharge and submarine groundwater discharge (SGD) to the sea and the associated N-NO3 fluxes. An integrated modelling approach has been developed, which couples the SWAT hydrologic model, MODFLOW-NWT groundwater flow model, and MT3DMS transport model. Transient simulations were performed for a 10 y period, assuming 10 different scenarios of land use (farming, grassland, forest) and crop types. Both recharge and SGD showed a distinct pattern of seasonal time variability. In terms of the average flow rates, the effect of varying crop type was more significant than that of land use change, with the minimum recharge and SGD corresponding to winter wheat and the maximum for peas and potatoes. Nitrate loads were strongly affected by both land use and crop type, with minimum values obtained for grassland and maximum values for canola.

  • EVALUATION OF THE NO2CONCENTRATION PREDICTION POSSIBILITYBASED ON STATIC AND DYNAMIC RESPONSES OF TGS SENSORSAT CHANGING HUMIDITY LEVELS
    • Paweł Kalinowski
    • Łukasz Woźniak
    • Grzegorz Jasiński
    • Piotr Jasiński
    2020 Pełny tekst Metrology and Measurement Systems

    The commercially available metal-oxide TGS sensors are widely used in many applications due to thefact that they are inexpensive and considered to be reliable. However, they are partially selective and theirresponses are influenced by various factors,e.g. temperature or humidity level. Therefore, it is importanttodesign a proper analysis system of the sensor responses. In this paper, the results of examinations of eightcommercial TGS sensors combined in an array and measured over a period of a few months for the purposeof prediction of nitrogen dioxide concentration are presented. The measurements were performed at differentrelative humidity levels. PLS regression was employed as a method of quantitative analysis of the obtainedsensor responses. The results of NO2concentration prediction based on static and dynamic responses ofsensors are compared. It is demonstrated that it is possibleto predict the nitrogen dioxide concentrationdespite the influence of humidity

  • Evaluation of the Possibility of Identifying a Complex Polygonal Tram Track Layout Using Multiple Satellite Measurements
    • Andrzej Wilk
    • Cezary Specht
    • Władysław Koc
    • Krzysztof Karwowski
    • Jacek Skibicki
    • Jacek Szmagliński
    • Piotr Chrostowski
    • Pawel S. Dabrowski
    • Mariusz Specht
    • Marek Zienkiewicz
    • Sławomir Judek
    • Marcin Skóra
    • Sławomir Grulkowski
    2020 Pełny tekst SENSORS

    We present the main assumptions about the algorithmization of the analysis of measurement data recorded in mobile satellite measurements. The research team from the Gda´nsk University of Technology and the Maritime University in Gdynia, as part of a research project conducted in cooperation with PKP PLK (Polish Railway Infrastructure Manager), developed algorithms supporting the identification and assessment of track axis layout. This article presents selected issues concerning the identification of a tramway line’s axis system. For this purpose, the supporting algorithm was developed and measurement data recorded using Global Navigation Satellite System (GNSS) techniques was evaluated and analyzed. The discussed algorithm identifies main track directions from multi-device data and repeated position recordings. In order to observe the influence of crucial factors, the investigated route was carefully selected. The chosen tramway track was characterized by its location in various field conditions and a diversified and complex geometric layout. The analysis of the obtained results was focused on the assessment of the signal’s dispersion and repeatability using residuals in relation to the estimated track’s direction. The presented methodology is intended to support railway infrastructure management processes, mainly in planning and maintenance through an effcient inventory of the infrastructure in service.

  • Evaluation of the resistance of steel–concrete adhesive connection in reinforced concrete beams using guided wave propagation
    • Beata Zima
    • Rafał Kędra
    2020 Archives of Civil and Mechanical Engineering

    The development of the nondestructive diagnostic methods is of significant importance in the last decades. A special attention is paid to diagnostics of reinforced concrete structures, which are very popular in the civil engineering field. A possible use of the guided waves in the estimation of the resistance of steel–concrete adhesive connection is studied in the following paper. The relationships relating adhesive connection resistance and wave propagation characteristics (wave velocity and the time of flight) have been derived and experimentally verified during pull-out tests conducted on a number of reinforced concrete beams varying in the debonding area. The pull-out tests were also monitored ultrasonically. On the basis of the results in the form of the time-domain signals, the theoretical load-carrying capacities of the pulled-out bars have been calculated and compared with the exact experimentally determined values. The high agreement of the results obtained proved the correctness of the developed method. Moreover, the signals registered during pull-out tests allowed to observe the changes of the wave velocity induced by the deterioration of the adhesive connection.

  • Evaluation of the significance of the effect of the active cross-sectional area of the inlet air channel on the specific enthalpy of the exhaust gas of a diesel engine using statistics F of the Fisher-Snedecor distribution
    • Patrycja Puzdrowska
    2020 Pełny tekst Combustion Engines

    This paper presents the application of Fisher-Snedecor distribution F statistics to assess the significance of the influence of changes in the active cross-sectional area of the inlet air channel (Adol) flow in a diesel engine on the observed diagnostic parameter determined on the basis of measurements of the quick changing exhaust gas temperature in the outlet channel, which is the specific enthalpy of the exhaust gas stream within one engine operating cycle (hspal). A plan of experimental tests carried out on the laboratory stand of a single-cylinder Farymann Diesel type D10 laboratory engine was presented and the method of determination of F statistics values for the obtained measurement results was characterized. Representative results of calculations were presented and the strength of Adol input parameter influence on the determined diagnostic parameter hspal simplified physical model of the working process of a compression ignition engine as the object of diagnosis was evaluated. It is planned to further develop the experimental research program to determine the significance of the influence of changes in the values of selected parameters of the engine structure on other diagnostic measures determined from the exhaust gas temperature signal, i.e. the mean peak-to-peak value as well as the rate (intensity) of increase and decrease in its value for individual engine cycles.

  • Evidence of mutations conferring resistance to clarithromycin in wastewater and activated sludge
    • Anna Gnida
    • Ewa Felis
    • Aleksandra Ziembińska-Buczyńska
    • Aneta Łuczkiewicz
    • Joanna Surmacz-Górska
    • Krystyna Olańczuk-Neyman
    2020 3 Biotech

    The occurrence of clarithromycin in wastewater samples and of the activated sludge bacteria possibly resistant to this pharmaceutical was the object of the study. Samples of wastewater or activated sludge were taken from a municipal wastewater treatment plant in summer and winter and characterised regarding their clarithromycin concentrations and the presence of nucleic acid fragments (Cla-sequences) known to be responsible for clarithromycin resistance in Helicobacter pylori. The concentrations of clarithromycin in raw wastewater were about 1086-2271 ng/L. Around 50-60% less of the pharmaceutical was found in treated wastewater. The concentrations were much higher in winter samples, as compared to summer samples. The clarithromycin resistance markers in H. pylori were detected by fluorescence in situ hybridisation in activated sludge bacterial cells. Cla-sequences were found in all the detected Proteobacteria, independently of the sampling season. Among nitrifying or phosphate or glycogen accumulating bacteria only Nitrosomonas spp. revealed presence of the clarithromycin sequences.

  • Evolution of Ag nanostructures created from thin films: UV–vis absorption and its theoretical predictions
    • Robert Kozioł
    • Marcin Łapiński
    • Paweł Syty
    • Damian Koszelow
    • Wojciech Sadowski
    • Józef Eugeniusz Sienkiewicz
    • Barbara Kościelska
    2020 Pełny tekst Beilstein Journal of Nanotechnology

    Ag-based plasmonic nanostructures were manufactured by thermal annealing of thin metallic films. Structure and morphology were studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS). SEM images show that the formation of nanostructures is influenced by the initial layer thickness as well as the temperature and the time of annealing. The Ag 3d and Ag 4d XPS spectra are characteristic of nanostructures. The quality of the nanostructures, in terms of their use as plasmonic platforms, is reflected in the UV–vis absorption spectra. The absorption spectrum is dominated by a maximum in the range of 450–500 nm associated with the plasmon resonance. As the initial layer thickness increases, an additional peak appears around 350 nm, which probably corresponds to the quadrupole resonance. For calculations leading to a better illustration of absorption, scattering and overall absorption of light in Ag nanoparticles, the Mie theory is employed. Absorbance and the distribution of the electromagnetic field around the nanostructures are calculated by finite-difference time-domain (FDTD) simulations. For calculations a novel approach based on modelling the whole sample with a realistic shape of the nanoparticles, instead of full spheres, was used. This led to a very good agreement with the experiment.

  • Evolution of magnetic and transport properties in (Cr1−xMnx)2AlC MAX-phase synthesized by arc melting technique
    • Kirill V. Sobolev
    • Kamil Kolincio
    • Andrey Emelyanov
    • Aleksandra Mielewczyk-Gryń
    • Maria Gazda
    • Marta Roman
    • Anna Pazniak
    • Valeria Rodionova
    2020 JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

    Herein we initiate a comeback to the arc melting technique to produce MAX-phase solid solutions. Bulk samples of (Cr1−xMnx)2AlC MAX-phase with X = 0, 0.025, 0.05 and 0.1 were synthesized and studied by means of X-ray diffractometry, scanning electron microscopy in combination with energy-dispersive X-ray spectroscopy. Samples were established to be homogeneous with an incorporation of Cr7C3, AlCr2 and Al2O3 secondary phases which is slightly increasing with the raise of the dopant concentration. Manganese successfully intermixes in the MAX-phase structure due to the effect of the high-energetic plasma during the melting process. SQUID magnetometry identified the co-existence of ferro- and antiferromagnetic interactions with the latter prevailing in high temperatures and being attributed to the MAX-phase. Magnetic state transitions were observed at approximately 4 K and 5 K for doped samples which was associated with the presence of the marginal amount of ferromagnetic Mn-based secondary phases. The negative component of magnetoresistance was observed in highly doped samples at low temperatures that is likely due to the influence of ferromagnetic secondary phases as well. Transport properties measurement revealed the satisfactory quality of the produced samples.

  • Evolution of the HVDC Link Connecting Offshore Wind Farms to Onshore Power Systems
    • Roland Ryndzionek
    • Łukasz Sienkiewicz
    2020 Pełny tekst ENERGIES

    This paper presents an overview of the DC link development and evolution dedicated to HVDC structure for connecting offshore wind power plants to onshore power systems. The growing demand for the green energy has forced investors in power industry to look for resources further out at sea. Hence, the development of power electronics and industrial engineering has enabled offshore wind farms to be situated further from the shore and in deeper waters. However, their development will require, among other technologies, DC-DC conversion systems. The advantages of HVDC over HVAC technology in relation to transmission distance are given. The different HVDC configurations and topologies of HVDC converters are elucidated. In this context, the HVDC grids are a promising alternative for the expansion of the existing AC grid.

  • EVOLUTIONARY MULTI–OBJECTIVE WEATHER ROUTING OF SAILBOATS
    • Ewa Sobecka
    • Rafał Szłapczyński
    • Marcin Życzkowski
    2020 Pełny tekst Polish Maritime Research

    The paper presents a multi-objective method, which optimises the route of a sailboat. The presented method makes use of an evolutionary multi-objective (EMO) algorithm, which performs the optimisation according to three objective functions: total passage time, a sum of all course alterations made during the voyage and the average angle of heel. The last two of the objective functions reflect the navigator’s and passenger’s comfort, which may decrease with multiple turns or when experiencing an excessive heel angle for a long time. The optimisation process takes into account static bathymetry-related constraints as well as dynamic constraints related to the sailboat’s safety in changing wind and wave conditions. The method makes use of all of the above and finally returns an approximated Pareto set containing non-dominated solutions to the optimisation problem. The developed method has been implemented as a simulation application. The paper includes selected simulation results followed by their discussion.

  • E-Voting System Evaluation Based on the Council of Europe Recommendations: nVotes
    • David Yeregui
    • David Duenas Cid
    • Hector Moretón
    • David Duenas-Cid
    2020 Pełny tekst

    E-voting implantation has been facing important challenges in recent years. Several incidents, together with a lack of evaluation methodologies social and cultural customs hinder a broader application. In this work, the authors aim to contribute to a safer introduction of e-voting tools by applying a practical evaluation framework strongly based on the security requirements issued by the Council of Europe (CoE) in 2017 to nvotes, a system that has been utilized to cast over 2 million votes over the last 6 years. The ultimate goal of the analysis is not to judge from a rigid, “infallible” but to contribute to a gradual and secure implementation of e-voting solutions in the democratic processes. The authors believe it can constitute a useful source of information for election officials, researchers and voters.

  • Exchange-Traded Funds on European Markets: Has Critical Mass been Reached? Implications for Financial Systems.
    • Adam Marszk
    • Ewa Lechman
    2020 Pełny tekst ENTROPY

    Exchange-traded funds (ETFs) are one of the most rapidly expanding categories of financial products in Europe. One of the key yet still unanswered questions is whether European ETF markets have reached the size at which they could affect the financial systems. In our study, we examine 13 European countries during the period 2004–2017 in order to trace whether the share of ETFs in the total assets of investment funds has reached the ‘critical’ level that makes possible their further growth and can be associated with an influence on the financial system. We use a novel methodological approach that identifies the ‘critical mass’ along diffusion trajectories. Our results show that, in 10 countries, the share of ETFs in assets of investment funds increased. Still, in most countries, the share of ETFs did not exceed 1%. Estimates of the diffusion models indicate that the process of growing shares of ETFs was most dynamic and relatively most stable in Switzerland and United Kingdom. Results of the critical mass analysis imply that its achievement may be forecasted exclusively in these two cases. However, even in such cases there is no substantial evidence for a possible significant influence of ETFs on the local financial systems.

  • Excited states of isoxazole molecules studied by electron energy-loss spectroscopy
    • Ireneusz Linert
    • Mariusz Zubek
    2020 Pełny tekst JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA

    Electron energy-loss spectra were measured in isoxazole in the excitation energy range 3.5−10 eV to investigate the valence excited states. Spectra recorded at different scattering conditions enabled the identification of the singlet and triplet states and the determination of their vertical excitation energies. The two lowest energy triplet bands, ππ* 13A' and ππ* 23A' at 4.20 and 5.30 eV, respectively show vibrational progressions. The first triplet state, 15a'π* 13A” that involves excitation from the nitrogen lone-pair orbital is observed at 5.68 eV. The three singlet valence states, ππ* 11A', nNπ* 11A” and ππ* 21A' are observed at 5.96, 6.49 and 6.88 eV, respectively in accord with the absorption measurements. Resonance excitation of the triplet and singlet states was noticed.