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  • Study on the Structure-Property Dependences of Rigid PUR-PIR Foams Obtained from Marine Biomass-Based Biopolyol
    • Paulina Kosmela
    • Aleksander Hejna
    • Jan Suchorzewski
    • Łukasz Piszczyk
    • Józef Haponiuk
    2020 Pełny tekst Materials

    The paper describes the preparation and characterization of rigid polyurethane-polyisocyanurate (PUR-PIR) foams obtained with biopolyol synthesized in the process of liquefaction of biomass from the Baltic Sea. The obtained foams differed in the content of biopolyol in polyol mixture (0–30 wt%) and the isocyanate index (IISO = 200, 250, and 300). The prepared foams were characterized in terms of processing parameters (processing times, synthesis temperature), physical (sol fraction content, apparent density) and chemical structure (Fourier transform infrared spectroscopy), microstructure (computer microtomography), as well as mechanical (compressive strength, dynamic mechanical analysis), and thermal properties (thermogravimetric analysis, thermal conductivity coefficient). The influence of biopolyol and IISO content on the above properties was determined. The addition of up to 30 wt% of biopolyol increased the reactivity of the polyol mixture, and the obtained foams showed enhanced mechanical, thermal, and insulating properties compared to foams prepared solely with petrochemical polyol. The addition of up to 30 wt% of biopolyol did not significantly affect the chemical structure and average cell size. With the increase in IISO, a slight decrease in processing times and mechanical properties was observed. As expected, foams with higher IISO exhibited a higher relative concentration of polyisocyanurate groups in their chemical structure, which was confirmed using principal component analysis (PCA).

  • Studying the Effect of Working Conditions on WEDM Machining Performance of Super Alloy Inconel 617
    • Stefan Dzionk
    • Mieczysław Siemiątkowski
    2020 Pełny tekst Machines

    Wire electrical discharge machining (WEDM) has been for many years a precise and efficient non-conventional manufacturing solution in various industrial applications, mostly involving the use of hard-to machine materials like, among other, the Inconel super alloys. The focus of the present study is on exploring the effect of selected control parameters, including pulse duration, pulse-off time and the dielectric flow pressure on the WEDM process performance characteristics of Inconel 617 material such, as: volumetric material removal rate (MRR), the dimensional accuracy of cutting (reflected by the kerf width) and surface roughness (SR). The research experiment has been designed and carried out using the response surface methodology (RSM) accordingly with the Box-Behnken design scheme. The results of experiments derived in the form of a fitted regression model have been subjected to the analysis of variance (Anova) tests. Thus, the variable process parameters and the relevant interactions between them characterized by a significant influence on the values of the derived output responses could be explicitly determined.

  • Subcritical Thermodynamic Cycles with Organic Medium and Isothermal Expansion
    • Krzysztof Kosowski
    • Marian Piwowarski
    2020 Pełny tekst ENERGIES

    The efffciencies of the Organic Rankine Cycle (ORC) are not very high and only very seldom do they exceed 20%. The increase and optimization of initial parameters and certain modifications of the thermodynamic cycle make it possible to overcome these drawbacks. A new modified cycle has been described and analyzed in detail in the paper. Similarly to the Ericsson cycle for gas turbines, isothermal expansion in the turbine is suggested for the power plant with organic media. The new cycle and the typical ORC power plants have the same block diagram. The only difference is that expansion in the proposed cycle occurs not adiabatically but as an isothermal process. The thermodynamic calculations have been carried out for 11 various fluids and 4 different cycles. The obtained results have clearly shown that cycles with isothermal expansion (isothermal turbines) are characterized by remarkably higher efffciency than typical power plants with adiabatic turbines. The increase in efffciency varies from 6 to 12 percent points for cycles with saturated live vapor and from 4 to 7 percent points for cycles with superheated live vapor. The performed analyses have shown that it is possible to achieve a very high efffciency (over 45%) of organic cycle, which is a very competitive value. In such cases the proposed power plants can achieve an efficiency which is higher than that of modern steam turbine plants with supercritical parameters.

  • SUBIEKTYWNA OCENA MULTIPLEKSU RADIOFONII LOKALNEJ DAB+ DZIAŁAJĄCEJ W GDAŃSKU I WROCŁAWIU
    • Przemysław Falkowski-Gilski
    • Stefan Brachmański
    • Andrzej Dobrucki
    2020 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    Standard DAB+ (Digital Audio Broadcasting plus) jest wiodącym systemem naziemnej radiofonii cyfrowej. W porównaniu do analogowej radiofonii FM wszystkie usługi, obejmujące tradycyjne programy radiowe oraz usługi transmisji danych, grupowane są w zbiór (ensemble). Praca ta przedstawia proces rekonfiguracji polskiego multipleksu na przykładzie lokalnej radiofonii DAB+ w Gdańsku i Wrocławiu. Opisuje wyniki badań subiektywnych dotyczących jakości programów radiowych nadawanych jednocześnie w technice cyfrowej i analogowej.

  • Subjective and Objective Quality Evaluation Study of BPL -PLC Wired Medium
    • Grzegorz Debita
    • Przemysław Falkowski-Gilski
    • Marcin Habrych
    • Bogdan Miedziński
    • Bartosz Polnik
    • Jan Wandzio
    • Przemysław Jedlikowski
    2020 Pełny tekst Elektronika Ir Elektrotechnika

    This paper presents results of research on the effectiveness of bi-directional voice transmission in a 6 kV mine cable network using BPL-PLC (Broadband over Power Line - Power Line Communication) technology. It concerns both emergency cable state (supply outage with cable shorted at both ends) and loaded with distorted current waveforms. The narrowband (0.5 MHz–15 MHz) and broadband (two different modes, frequency range of 3 MHz–7.5 MHz) transmission efficiency, considered as an objective study, was correlated with the level of noise in the cable for both induction-inductive and mixed capacitive-inductive coupling of the measurement devices and/or modems. The quality of voice transmission, considered as a subjective study, was assessed by a group of 15 people aged between 25 and 35 years old. The test audio signals included samples in 3 languages sourced from ITU (International Telecommunication Union) and processed in 3 bitrates ranging from 8 kbps to 24 kbps.

  • Subjective Quality Evaluation of Speech Signals Transmitted via BPL-PLC Wired System
    • Przemysław Falkowski-Gilski
    • Grzegorz Debita
    • Marcin Habrych
    • Bogdan Miedziński
    • Przemysław Jedlikowski
    • Bartosz Polnik
    • Jan Wandzio
    • Xin Wang
    2020

    The broadband over power line – power line communication (BPL-PLC) cable is resistant to electricity stoppage and partial damage of phase conductors. It maintains continuity of transmission in case of an emergency. These features make it an ideal solution for delivering data, e.g. in an underground mine environment, especially clear and easily understandable voice messages. This paper describes a subjective quality evaluation of such a system. The solution was designed and tested in real-time operating conditions. It consists of a one-way transmission system, dedicated to delivering speech signals and voice commands. The study involved signal samples in three languages: English, German, and Polish, processed at different bitrates: 8, 16, and 24 kbps. Obtained results confirmed the usefulness of BPL-PLC technology for speech transmission purposes. Even in a narrowband scenario, with bitrates smaller than 1 Mbps, it proved to be a potentially life-saving communication system. Results of this study may aid researchers and parties from the mining and oil industry, as well as professionals involved in rescue operations.

  • Subjective Quality Evaluation of Underground BPL-PLC Voice Communication System
    • Grzegorz Debita
    • Przemysław Falkowski-Gilski
    • Marcin Habrych
    • Bogdan Miedziński
    • Bartosz Polnik
    • Jan Wandzio
    • Przemysław Jedlikowski
    2020

    Designing a reliable voice transmission system is not a trivial task. Wired media, thanks to their resistance to mechanical damage, seem an ideal solution. The BPL-PLC (Broadband over Power Line – Power Line Communication) cable is resilient to electricity stoppage and partial damage of phase conductors. It maintains continuity of transmission in case of an emergency situation, including paramedic rescue operations. These features make it an ideal solution for delivering data, e.g. in an underground mine environment. This paper describes a subjective quality evaluation of such a system. The solution was designed and tested in real-time operating conditions. It involved two types of coupling, namely: induction-inductive and capacitive-inductive, as well as two transmission modes (Mode 1 and Mode 11 operating in the 2–7.5 MHz frequency range). The tested one-way transmission system was designed to deliver clear and easily understandable voice messages. The study involved signal samples in three languages: English (both British and American dialects), German, and Polish, processed in three bitrates: 8, 16, and 24 kbit/s, with the Ogg Vorbis codec. Obtained results confirmed the usefulness of the BPL-PLC technology for voice communication purposes. Results of this study may be of interest to professionals from the mining and oil industry.

  • Submicron inorganic particles as an additional filler in hybrid epoxy matrix composites reinforced with glass fibres
    • Marcin Włoch
    • Filip Bagiński
    • Piotr Koziński
    • Janusz Datta
    2020 POLYMERS & POLYMER COMPOSITES

    In this study, the effect of selected submicron metal oxide (zinc oxide, titanium oxide) or non-metal oxide (silicon dioxide) particles on mechanical and thermo-mechanical properties of epoxy/glass composites was investigated. The applied epoxy resin was a diglycidyl ether of bisphenol-A cured with triethylenetetramine. As a reinforcement twill weave E-glass fabric was used. Hybrid composites (contained particulate and fibrous filler) were fabricated by using the hand lay-up method and the average content of glass fibres was 39–41 wt%. Flexural properties, thermo-mechanical properties, abrasion resistance and hardness were determined for each group of the prepared hybrid epoxy/glass composites. The obtained results were compared with control samples (without submicron particles). Investigations showed that the addition of 2 wt% SiO2, 4 wt% TiO2 or 4 wt% ZnO to epoxy resin improved the flexural strength and the flexural modulus of composites. Dynamic mechanical analysis showed that the addition of the mentioned particles enhanced storage and loss modulus. It can be attributed to the good dispersion and good interaction between submicron-mentioned particles and the epoxy matrix.

  • Sub-national structures matter when evaluating physical activity promotion: Lessons from Germany
    • Sarah Forberger
    • Peter Gelius
    • Sven Messing
    • Kevin Volf
    • Liam Kelly
    • Simon J. E. Taylor
    • Joanna Żukowska
    • Jeroen Lakerveld
    • Catherine Woods
    2020 EUROPEAN JOURNAL OF PUBLIC HEALTH

    Background Public policies are increasingly acknowledged as important part of promoting physical activity (PA). However, especially in states with sub-national administrative structures such as Germany, national and sub-national approaches differ considerably. In Germany, sport for all (SfA) promotion is mostly organized at sub-national level, which is usually not covered in national evaluations. Knowledge of these structures helps to understand national outcomes, enables comparisons and learning within and between countries, and assists in identifying support structures for effective PA promotion. Methods Data were collected in the PEN Policy Evaluation Network project. In addition to the WHO HEPA PAT, a questionnaire was sent to the sports representatives of the 16 federal states. Responses of 11 state representatives were included and overarching issues were identified using inductive thematic analysis. Results PA promotion in Germany is organized in three areas: SfA, professional sports and school sports. SfA promotion at sub-national level is assigned to different administrative bodies (ministries, senate administration, state chancellery) and policy areas: culture, health and care, home affairs with various aspects, education, social affairs and family. The priorities of the federal states are more diverse and specific compared to the national level. There is an overlap in the topics: urban planning, cycling, health prevention and targeting children. Cooperation mechanisms and partners vary between federal states, but some partners are active at sub-national and national level. Conclusions The results provide an insight into the complexity of PA and especially SfA promotion at sub-national level in Germany. Our results suggest that a broader range of approaches is used in the 16 German states than national overviews would suggest. These particularities must be taken into account when assessing and comparing the results from different countries.

  • Substancje biogenne i inne problemy w zarządzaniu wodami opadowymi w portach
    • Klaudia Kosek
    • Małgorzata Szopińska
    • Hubert Byliński
    • Wojciech Artichowicz
    • Sylwia Fudala-Książek
    • Aneta Łuczkiewicz
    2020 Pełny tekst Pismo PG

    Do niedawna uważano, że substancjami zanieczyszczającymi wody portowe są głównie substancje ropopochodne. Ich rozlewy powstawały najczęściej w wyniku awarii, nieuwagi lub np. zatonięcia statku. W ostatnich latach jednak organizacja HELCOM w roboczych dokumentach pt.: „Draft Report on potentialsources of nutrientinputs: Baltic Sea portshandlingfertilizers” (HOD 52-2017) oraz „Results of the questionnaire on fertilizer cargo handling in Baltic Sea ports” (MARITIME 18-2018) zwraca uwagę na przeładunek substancji sypkich, takich jak nawozy, czy pasze dla zwierząt. Straty podczas ich załadunku/rozładunku i składowania, mycia ładowni, a także niewłaściwego zarządzania wodą opadową powoduje, iż istotny ładunek substancji organicznej, fosforu i azotu trafia do wód portowych. Co istotne ilość substancji nawozowych przeładowywanych w portach Morza Bałtyckiego stale rośnie (od ok 33 milionów ton w 2013 r. do ok. 45 milionów ton w 2015 r.). Wychodząc naprzeciw wyzwaniom polityki środowiskowej związanej z koniecznością monitoringu i ograniczenia emisji substancji biogennych do wód Morza Bałtyckiego, w Katedrze Technologii Wody i Ścieków, na wydziale Inżynierii Lądowej i Środowiska Politechniki Gdańskiej, w ramach Programu „Interreg Południowy Bałtyk”, realizowany jest projekt „Water Innovation System Amplifier” (WISA) - „Innowacyjne zielone technologie wspomagające gospodarkę wodami opadowymi”, 2019 – 2022 (STHB.02.02.00-SE-0153/18). Jego głównym celem jest opracowanie i wdrożenie technologii ograniczających emisję związków biogennych i innych zanieczyszczeń z obszarów portowych do przybrzeżnych wód Morza Bałtyckiego. Liderem projektu WISA jest Krinova AB z siedzibą w Kristianstad w Szwecji, a partnerami, poza Politechniką Gdańską, Uniwersytet w Kłąjpedzie, Port w Gdyni, Port w Åhus, oraz Gmina Hässleholm. Do współpracy w projekcie WISA zostali zaproszeni także lokalni przedsiębiorcy oraz organizacje pozarządowe, które mogłyby być zainteresowane wdrożeniem innowacyjnych narzędzi gospodarowania wodami opadowymi, zarówno w zakresie ich oczyszczania jak i możliwości ich ponownego wykorzystania.

  • Substrate Dependence in the Formation of Au Nanoislands for Plasmonic Platform Application
    • Marcin Łapiński
    • Robert Kozioł
    • Anita Cymann
    • Wojciech Sadowski
    • Barbara Kościelska
    2020 Pełny tekst PLASMONICS

    In this work, the influence of the various substrates on Au nanoisland formation has been studied. Nanostructures were obtained via annealing of thin Au films. In order to determine nanoisland formation mechanisms, correlation between an initial film thickness and temperature of formation, shapes, and dimensions of nanostructures was examined. For the surface morphology studies, nanograin structure, and chemical composition analysis, SEM, HR TEM, and EDS measurements were performed, respectively. Morphology studies showed that the temperature at which nanostructures form varies for different substrates, which indicates high impact of the substrate material on the nanostructure formation. In the case of silicon substrate, besides the phenomenon of spinodal dewetting, the effect of eutectics on the nanostructures was additionally taken into consideration.

  • Sugar matters: sugar moieties as reactivity-tuning factors in quercetin O-glycosides
    • Cezara Zagrean-Tuza
    • Augusitn Mot
    • Tomasz Chmiel
    • Attila Bende
    • Ioan Turcu
    2020 Pełny tekst Food & Function

    Quercetin, one of the most abundant flavonoids in plant-based foods, commonly occurs in nature in various glycosylated forms. There is still a less explored aspect regarding the cause of its glycosides diversity, depending on the sugars moiety attached. This work focuses on four widespread quercetin glycosides—hyperoside, isoquercitrin, quercitrin and rutin—by testing property-tuning capacity of different sugar moieties and thus explain and predict some of their functions in plant-based food. Electron paramagnetic spectra of the semiquinone anion radicals of these glycosides were interpreted in terms of hyperfine coupling constants and linewidths, highlighting a clear link between spin density trends, the identity of the bound sugar, as well as their reactivity corroborated with their modelled structures. Redox potential and lipophilicity were connected to a specific flavonoid-enzyme interaction and correlated with their prooxidant reactivity assessed by oxidation of ferrous hemoglobin. Hyperoside and isoquercitin—galactose and glucose glycosides—exhibit the highest prooxidant reactivity owing to their lowest redox potential and lipophilicity whereas rutin and quercitrin—rutinose and rhamnose glycosides—behave vice versa. The ability of the tested glycosides to undergo HAT or SET-type reactions has also been tested using five different analytical assays, including inhibition of cytochrome ctriggered liposome peroxidation. In most cases, rutin proved to be the most unreactive of all four tested glycosides considering either steric or redox reasons whereas the reactivity hierarchy of the other three glycosides were rather assay dependent.

  • Superconductivity in Metal-Rich Chalcogenide Ta2Se
    • Xin Gui
    • Karolina Górnicka
    • Qiang Chen
    • Haidong Zhou
    • Tomasz Klimczuk
    • Weiwei Xie
    2020 INORGANIC CHEMISTRY

    The metal–metal bond in metal-rich chalcogenide is known to exhibit various structures and interesting physical properties. Ta2Se can be obtained by both arc-melting and solid-state pellet methods. Ta2Se crystallizes a layered tetragonal structure with space group P4/nmm (No. 129; Pearson symbol tP6). Each unit cell consists of four layers of body-centered close-packing Ta atoms sandwiched between two square nets of Se atoms, forming the Se–Ta–Ta–Ta–Ta–Se networks. Herein, we present magnetic susceptibility, resistivity, and heat capacity measurements on Ta2Se, which together indicate bulk superconductivity with Tc = 3.8(1) K. According to first-principles calculations, the d orbitals in Ta atoms dominate the Fermi level in Ta2Se. The flat bands at the Γ point in the Brillouin zone yield the van Hove singularities in the density of states around the Fermi level, which is intensified by introducing a spin–orbit coupling effect, and thus could be critical for the superconductivity in Ta2Se. The physical properties, especially superconductivity, are completely different from those of Ta-rich alloys or transition-metal dichalcogenide TaSe2.

  • Superconductivity on a Bi Square Net in LiBi
    • Karolina Górnicka
    • Sylwia Gutowska
    • Michał Winiarski
    • Bartlomiej Wiendlocha
    • Weiwei Xie
    • R.j. Cava
    • Tomasz Klimczuk
    2020 Pełny tekst CHEMISTRY OF MATERIALS

    We present the crystallographic analysis, superconducting characterization and theoretical modeling of LiBi, that contains the lightest and the heaviest nonradioactive metal. The compound crystallizes in a tetragonal (CuAu-type) crystal structure with Bi square nets separated by Li planes (parameters a = 3.3636(1)Å and c = 4.2459(2) Å, c/a = 1.26). Superconducting state was studied in detail by magnetic susceptibility and heat capacity measurements. The results reveal that LiBi is a moderately coupled type-I superconductor (λe‑p = 0.66) with Tc = 2.48 K and a thermodynamic critical field Hc(0) = 157 Oe. Theoretical studies show that bismuth square net is responsible for superconductivity in this compound, but the coupling between the Li planes and Bi planes makes a significant contribution to the superconductivity.

  • Super-resolved Thermal Imagery for High-accuracy Facial Areas Detection and Analysis
    • Alicja Kwaśniewska
    • Jacek Rumiński
    • Maciej Szankin
    • Mariusz Kaczmarek
    2020 Pełny tekst ENGINEERING APPLICATIONS OF ARTIFICIAL INTELLIGENCE

    In this study, we evaluate various Convolutional Neural Networks based Super-Resolution (SR) models to improve facial areas detection in thermal images. In particular, we analyze the influence of selected spatiotemporal properties of thermal image sequences on detection accuracy. For this purpose, a thermal face database was acquired for 40 volunteers. Contrary to most of existing thermal databases of faces, we publish our dataset in a raw, original format (14-bit depth) to preserve all important details. In our experiments, we utilize two metrics usually used for image enhancement evaluation: Peak-Signal-to-Noise Ratio (PSNR) and Structural Similarity Index Metric (SSIM). In addition, we present how to design a SR network with a widened receptive field to mitigate the problem of contextual information being spread over larger image regions due to the heat flow in thermal images. Finally, we determine whether there is a relation between achieved PSNR and accuracy of facial areas detection that can be analyzed for vital signs extraction (e.g. nostril region). The performed evaluation showed that PSNR can be improved even by 60\% if full bit depth resolution data is used instead of 8 bits. Also, we showed that the application of image enhancement solution is necessary for low resolution images to achieve a satisfactory accuracy of object detection.

  • Supervisory fuzzy control system for biological processes in sequencing wastewater batch reactor
    • Robert Piotrowski
    2020 Urban Water Journal

    The paper proposes the design of the supervisory heuristic fuzzy control system applied to a Sequencing Batch Reactor (SBR) in the Wastewater Treatment Plant (WWTP). Based on real data records and the biological process and aeration system models, a control system for biological processes has been designed. The supervisory control system performs management of the reactor work cycle, determines the phase length, controls the sludge age, calculates the setpoint of dissolved oxygen, and adapts parameters of the lower control layer. The results of simulation tests for the case study wastewater treatment plant are presented.

  • Supporting study tours in the teaching of architectural heritage
    • Michał Kwasek
    • Aleksander Piwek
    2020 Pełny tekst World Transactions on Engineering and Technology Education

    Study tours are a highly effective way to acquire knowledge. They improve students’ understanding of issues that otherwise may seem partly abstract to them. Presented in this article is the unique way in Poland in which support is given to the teaching of architectural heritage. It has been carried out continuously for almost 50 years in the Faculty of Architecture at Gdańsk University of Technology (FA-UT), Gdańsk, Poland, in co-operation with the staff and the Students’ Tourist Association (TXA), which also organises scientific trips. Knowledge of historical architecture provides students with a link to contemporary architecture. Study tours enable students to benefit from direct contact with historic buildings; thus they become aware of the scale as well as the nature of them. This improves students’ understanding of the theory. For the teacher, the study tour is an attractive teaching model. Demonstrated in this article are the advantages of the study tours, their impact on education and their potentialities.

  • Suppression of Supply Current Harmonics of 18-Pulse Diode Rectifier by Series Active Power Filter with LC Coupling
    • Wojciech Śleszyński
    • Artur Cichowski
    • Piotr Mysiak
    2020 Pełny tekst ENERGIES

    The reported research aims at improving the quality of three-phase rectifier supply currents. An effective method consists of adding properly formed booster voltages to the fundamental supply voltages using a series active filter. In the proposed solution, the booster voltages are generated by three single-phase systems consisting of inverters, LC filters, and single-phase transformers. The application of LC couplings ensures low emission of disturbances, but may provoke compensator stability problems. The article presents the current control system for a series active filter designed to suppress the dominant harmonics in the supply currents of an 18-pulse rectifier, without interference into fundamental current components. A proportional control is proposed in combination with integral terms implemented in the orthogonal coordinate systems, which synchronically rotate with frequencies equal to those of the harmonic components to be eliminated. The use of complex gains in integral terms allows a simple phase correction of the output signals. A description is given of the method to determine controller parameters based on the mathematical model of the control object. Sample results of experimental tests performed in steady-state and transient conditions are included to illustrate the quality of performance of the series active filter as compared to the results recorded for the rectifier alone, and for the rectifier with additional line reactor. The applied control method of active filter significantly reduces harmonic distortion of the grid current, which is particularly advantageous at nonideal supply voltage and low loads.

  • Surface and Corrosion Properties of AA6063-T5 Aluminium Alloy in Molybdate-containing Sodium Chloride Solutions
    • Dmitry Kharitonov
    • Illia Dobryden
    • Birhan Sefer
    • Jacek Ryl
    • Angelika Wrzesińska
    • Irina Makarova
    • Izabela Bobowska
    • Irina Kurilo
    • Per Claesson
    2020 Pełny tekst CORROSION SCIENCE

    Corrosion properties of aluminium alloy AA6063-T5 were investigated in molybdate-containing NaCl solutions. Electrochemical, microscopic, and spectroscopic experiments were utilized to examine the mechanism of corrosion inhibition by molybdates. SEM-EDX, magnetic force, and intermodulation electrostatic force microscopy data suggested that the inhibition initiation preferentially occurred over Fe-rich cathodic IMPs. Spectroscopic measurements demonstrated that the formed surface layer consists of mixed Mo(VI, V, IV) species. This layer provided inhibition with an efficiency of ∼90% after 4 h of exposure. High efficacy of ∼70% was achieved even after one week of exposure. A two-step oxidation-reduction mechanism of corrosion inhibition by aqueous molybdates was proposed

  • Surface diffusion and cluster formation of gold on the silicon (111)
    • Walery Pleczysty
    • Ihor Shtablavyi
    • Kamil Rybacki
    • Szymon Winczewski
    • Stepan Mudry
    • Jarosław Rybicki
    2020 Pełny tekst Journal of Achievements in Materials and Manufacturing Engineering

    Purpose: Investigation of the gold atoms behaviour on the surface of silicon by molecular dynamics simulation method. The studies were performed for the case of one, two and four atoms, as well as incomplete and complete filling of gold atoms on the silicon surface. Design/methodology/approach: Investigations were performed by the method of molecular dynamics simulation using the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS). MEAM potential of interatomic interaction was used for modelling. Molecular dynamic simulations were carried out in isothermal-isobaric ensemble (NpT) with a timestep 1.0 fs. Findings: As a result of studies, the preferred interaction between gold atoms and the formation of clusters at temperatures up to 800 K was revealed. Analysis of the temperature dependences of the number of large jumps of atoms made it possible to calculate the activation energy of a single jump. It was found that activation energy of single atomic displacement decreases with increasing number of gold atoms. Research limitations/implications: Only a limited number of sets of atoms were used in the study. It is possible that for another combination of atoms and a larger substrate surface, the formation of gold nanoislands on the silicon surface can be observed, which requires further research. Practical implications: The research results can be used to select the modes of gold sputtering to create gold nanoislands or nanopillars on the silicon surface. Originality/value: Computer modelling of the behaviour of gold atoms on the surface of silicon with the possibility of their self-organization and cluster formation was performed for the first time.

  • Surface effects of network materials based on strain gradient homogenized media
    • Yosra Rahali
    • Victor Eremeev
    • Jean-François Ganghoffer
    2020 Pełny tekst MATHEMATICS AND MECHANICS OF SOLIDS

    The asymptotic homogenization of periodic network materials modeled as beam networks is pursued in this contribution, accounting for surface effects arising from the presence of a thin coating on the surface of the structural beam elements of the network. Cauchy and second gradient effective continua are considered and enhanced by the consideration of surface effects. The asymptotic homogenization technique is here extended to account for the additional surface properties, which emerge in the asymptotic expansion of the effective stress and hyperstress tensors versus the small scale parameters and the additional small parameters related to surface effects. Based on the elaboration of small dimensionless parameters of geometrical or mechanical nature reflecting the different length scales, we construct different models in which the importance of surface effects is dictated by specific choice of the scaling relations between the introduced small parameters. The effective moduli reflect the introduced surface properties. We show in particular that surface effects may become dominant for specific choices of the scaling laws of the introduced small parameters. Examples of networks are given for each class of the considered effective constitutive models to illustrate the proposed general framework.

  • Surrogate modeling of impedance matching transformers by means of variable‐fidelity electromagnetic simulations and nested cokriging
    • Anna Pietrenko-Dąbrowska
    • Sławomir Kozieł
    2020 Pełny tekst INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING

    Accurate performance evaluation of microwave components can be carried out using full‐wave electromagnetic (EM) simulation tools, routinely employed for circuit verification but also in the design process itself. Unfortunately, the computational cost of EM‐driven design may be high. This is especially pertinent to tasks entailing considerable number of simulations (eg, parametric optimization, statistical analysis). A possible way of alleviating these difficulties is utilization of fast replacement models, also referred to as surrogates. Notwithstanding, conventional modeling methods exhibit serious limitations when it comes to handling microwave components. The principal challenges include large number of geometry and material parameters, highly nonlinear characteristics, as well as the necessity of covering wide ranges of operating conditions. The latter is mandatory from the point of view of the surrogate model utility. This article presents a novel modeling approach that incorporates variable‐fidelity EM simulations into the recently reported nested kriging framework. A combination of domain confinement due to nested kriging, and low‐/high‐fidelity EM data blending through cokriging, enables the construction of reliable surrogates at a fraction of cost required by single‐fidelity nested kriging. Our technique is validated using a three‐section miniaturized impedance matching transformer with its surrogate model rendered over wide range of operating frequencies. Comprehensive benchmarking demonstrates superiority of the proposed method over both conventional models and nested kriging.

  • Survey of Methodologies, Approaches, and Challenges in Parallel Programming Using High-Performance Computing Systems
    • Paweł Czarnul
    • Jerzy Proficz
    • Krzysztof Drypczewski
    2020 Pełny tekst Scientific Programming

    This paper provides a review of contemporary methodologies and APIs for parallel programming, with representative technologies selected in terms of target system type (shared memory, distributed, and hybrid), communication patterns (one-sided and two-sided), and programming abstraction level. We analyze representatives in terms of many aspects including programming model, languages, supported platforms, license, optimization goals, ease of programming, debugging, deployment, portability, level of parallelism, constructs enabling parallelism and synchronization, features introduced in recent versions indicating trends, support for hybridity in parallel execution, and disadvantages. Such detailed analysis has led us to the identification of trends in high-performance computing and of the challenges to be addressed in the near future. It can help to shape future versions of programming standards, select technologies best matching programmers’ needs, and avoid potential difficulties while using high-performance computing systems.

  • Sustainability of Cluster Organizations as Open Innovation Intermediaries
    • Anna Lis
    • Marita Mcphillips
    • Adrian Lis
    2020 Pełny tekst Sustainability

    The purpose of the paper is to identify the most important open innovation practices used by cluster organizations (COs). To reflect these practices, the paper uses the concept of the trajectory of relationship development in COs, applied in the Interizon cluster organization. Additionally, this paper introduces the potential sustainability-related implications of open innovation adoption in cluster organizations. An in-depth direct interview and secondary data analysis were the basic techniques used for data collection. The study demonstrates that cluster organizations can play the role of open innovation intermediaries, implementing a set of different open innovation practices, depending on the level of advancement of cluster cooperation. The use of these practices leads to the development of ever stronger relationships between cluster members, thus conditioning access to the increasingly valuable resources of information and knowledge which are most relevant for the future sustainability-pursuing context. The good effects of multidimensional cooperation in the studied cluster organization prompted the authors to formulate a recommendation for sustainable diversity in the CO. The research goes beyond the state-of-the-art knowledge in the concept of industrial clusters by exposing a broader view on cooperation developed within cluster organizations. The study links the issue of clustering with the concept of open innovation, shedding new light on the processes of supporting knowledge and information flows in COs. Additionally, it contributes to developing a broader comprehension of the context dependencies of open innovation for potential sustainable innovation.

  • Sustainable energy system combined biogas-feedSolid Oxide Fuel Cell and Microalgae technology
    • Araceli Fuerte
    • Rita Ximena Valenzuela
    • Paloma Ferreira-Aparicio
    • B. Bochentyn
    2020 Pełny tekst

    In the new frontier of energy and environmental safety, new efficient and clean safe energy conversion systems are required. In this sense, the present work is framed within the context of Circular Economy and proposes a multidisciplinary study for the development of more efficient, economically viable and non-polluting energy conversion systems, based on the synergetic combination of different technologies: fuel cells, biofuels, CO2 capture, and the use of solar energy and microalgae. In a first step, a doped cerium oxide (Rh/Cu-CeCa) was evaluated as SOFC anode at 1023 K and using H2 and biogas from different sources (algal biogas and landfill biogas) as fuel. Achieved maximum power density for the single cell running on algal biogas was 80 % higher than that obtained with landfill biogas. The comparative study shows the benefits of algal biogas as fuel for SOFC and clean energy production.

  • Synergistic effect of MWCNTs and MA-g-PP on the thermal and viscoelastic properties of immiscible PTT/PP blends
    • Ajitha Anthickamalil Ramachandran
    • Arunima Reghunadhan
    • Aswathi Madathinal Kunjappan
    • Lovely P. Mathew
    • Sabu Thomas
    • David Laroze
    • Michał Strankowski
    2020 NEW JOURNAL OF CHEMISTRY

    The properties of immiscible blends of PTT and PP were modified by grafting and nanoparticle inclusion. The observed synergistic effect of MWCNTs and MA-g-PP on the thermal and viscoelastic properties of PTT/PP blends was studied in detail and the properties of the composites were compared with those of ungrafted PP.

  • Synergistic effect of TiO2 photocatalytic advanced oxidation processes in the treatment of refinery effluents
    • Andre Fernandes
    • Patrycja Makoś
    • Zhaohui Wang
    • Grzegorz Boczkaj
    2020 Pełny tekst CHEMICAL ENGINEERING JOURNAL

    Different types of photolytic and photocatalytic advanced oxidation processes (AOPs) were used for treatment of refinery effluents from bitumen production. The treatment efficiency was evaluated by analyzing chemical oxygen demand (COD), biological oxygen demand (BOD5), volatile organic compounds (VOCs) and sulfide ions concentration. The studies revealed a synergistic effect of application of external oxidants (O3, H2O2, O3/H2O2) with TiO2 and UV applied for improved COD and BOD5 reduction as well as the degradation of the VOCs present in the effluents. Among studied processes a photocatalytic process combined with peroxone (TiO2/UV/O3/H2O2) was the optimal and the most economical technology. It allows to reduce 38 and 32% of COD and BOD5 respectively and degrade 84% of total VOCs in 280 min of treatment. At this conditions the reduced COD exceeds over 30% a theoretical value based on the dose of oxidants, which proves the importance of photocatalysis in the developed technology. The sulfide ions were completely depleted in all experiments in the first 30 min of treatment. The addition of TiO2 in the AOPs technology revealed a decrease in the process cost using less amount of chemicals achieving similar treatment efficiency when comparing with photolytic and non-catalytic technologies. The application of these technologies can be conducted in two alternative scenarios; whether to deplete the sulfides ions concentration or to maximize the treatment efficiency. In both options, the technologies studied are promising as a pre-treatment before other types of AOPs effective at neutral/acidic pH values or before a biological treatment stage. Further studies should be developed, by scaling up the process to a pilot scale in a real case scenario to check the possibility of its implementation in the industrial practice.

  • Synergy between AgInS2 quantum dots and ZnO nanopyramids for photocatalytic hydrogen evolution and phenol degradation
    • María C. Nevárez Martínez
    • Beata Bajorowicz
    • Tomasz Klimczuk
    • Andrzej Żak
    • Justyna Łuczak
    • Wojciech Lisowski
    • Adriana Zaleska-Medynska
    2020 JOURNAL OF HAZARDOUS MATERIALS

    Despite the unique properties of single semiconductor nanomaterials and quantum dots, poor photocatalytic activity has characterized them and the fabrication of nanocomposites has become necessary to enhance their photocatalytic performance. Thus, AgInS2 quantum dots (AIS QDs, 4.0±1.6 nm), have been successfully prepared and loaded onto ZnO nanopyramids (ZnO NPy). The effect of the nominal amount of AIS QDs decorating ZnO NPy on the morphology, optical properties, structure and surface chemistry of the nanocomposites was systematically studied. Photocatalytic tests revealed that the 1%AIS@ZnO NPy sample reported the highest photoactivity for phenol degradation in aqueous phase (92 % after one hour of irradiation, λ>350 nm) that was 4 and 68 times the reported for bare ZnO NPy and AIS QDs, respectively. Accordingly, the maximum photocatalytic hydrogen evolution, under UV–vis light, for the same sample corresponded to 17 and 21 times the estimated for pristine ZnO NPy and AIS QDs, respectively. Hence, the AIS QDs – ZnO system has been applied in the photocatalytic field for the first time in this work and a synergetic effect was confirmed owing to a strong heterojunction formation between both semiconductors that allows an enhanced charge carrier separation, improving the photocatalytic activity.

  • Synteza, struktura chemiczna i właściwości termoplastycznych bio-poli(etero-uretanów) syntezowanych z surowców pochodzenia roślinnego.
    • Paulina Kasprzyk
    2020 Pełny tekst

    Przeprowadzone studia literaturowe, zaprezentowane w części teoretycznej dysertacji, umożliwiły wskazanie głównego kierunku badawczego w ramach studiów doktoranckich. Zaplanowane badania miały na celu opracowanie syntezy oraz zbadanie struktury chemicznej i właściwości nowych termoplastycznych bio-poli(etero-uretanów) (TPUs) otrzymywanych z zastosowaniem monomerów pochodzenia roślinnego. Zrealizowane badania zostały podzielone na trzy główne etapy. Pierwszy z nich polegał na syntezie TPUs z zastosowaniem jednego monomeru pochodzenia roślinnego, którym był bio-glikol. W kolejnym etapie do struktury TPUs wprowadzono bio-poliol. Ostatni etap polegał na modyfikacji triizocyjanianu, w celu otrzymania monomeru dwufunkcyjnego, który lepiej nadawał się do syntezy TPUs. W pracy wykonano także syntezy TPUs z monomerów petrochemicznych w celu otrzymania próbek referencyjnych. Wszystkie TPUs były otrzymywane metodą dwu-etapową. W badaniach otrzymanych materiałów wykorzystano spektroskopię w podczerwieni z transformacją Fouriera, magnetyczny rezonans jądrowy, skaningową kalorymetrię różnicową, dyfrakcję rentgenowską, analizę termiczną dynamicznych właściwości mechanicznych, analizę termograwimetryczną oraz pomiar właściwości wytrzymałościowych w warunkach statycznych. Zbadano przetwarzalność TPUs poprzez pomiary wskaźnika szybkości płynięcia. W rezultacie przeprowadzonych badań wykazano, że możliwe jest TPUs z wykorzystaniem monomerów pochodzenia roślinnego o właściwościach porównywalnych, a nawet lepszych do TPUs syntezowanych w 100% z pochodnych ropy naftowej.

  • Synteza, właściwości i struktura wybranych pochodnych tiomocznika oraz ich związków kompleksowych z kationami metali o konfiguracji d10
    • Damian Rosiak
    2020 Pełny tekst

    Przedstawiona rozprawa doktorska poświęcona jest 1-benzoilotiomocznikom i produktom ich reakcji z halogenkami metali o konfiguracji elektronowej d10 (miedziowce na +1 stopniu utlenienia i cynkowce na +2 stopniu utlenienia) ze szczególnym nastawieniem na ich związki kompleksowe. Istota i cel takich badań przedstawione są we wstępie pracy. Na początku części teoretyczno-literaturowej opisane zostały pochodne tiomocznika ze szczególnym uwzględnieniem 1-acylotiomoczników. Następnie scharakteryzowane zostały metale tworzące kationy o konfiguracji elektronowej d10, które wykorzystano do syntezy połączeń kompleksowych. W dalszej części opisano, czym są związki kompleksowe oraz przedstawiono ich podział ze względu na wymiarowość oddziaływań oraz geometrię ich centrów koordynacyjnych. Omówiono także motywy strukturalne tworzone przez związki kompleksowe 1-acylotiomoczników z miedziowcami i cynkowcami. Zakończeniem tej części jest opis oddziaływań występujących w przedstawianych w dalszej części strukturach krystalicznych i zestawienie stosowanych parametrów. Następnym rozdziałem jest część eksperymentalna, w której przedstawiono techniki badawcze, oraz opisy syntez 1-benzoilotiomoczników i ich związków kompleksowych z halogenkami miedziowców i cynkowców. Kolejny rozdział zawiera opis otrzymanych 1-benzoilo-tiomoczników, związków kompleksowych oraz produktów reakcji pobocznych. Zsyntezowanie dużej liczby ligandów o różnym rozmieszczeniu podstawników oraz użycie różnych halogenków metali pozwoliło na otrzymanie szerokiej gamy związków kompleksowych, co z kolei dało możliwość prowadzenia dyskusji na temat wpływu części organicznej oraz nieorganicznej na ich finalną strukturę. Na zakończenie podjęta została dyskusja wyników i analiza porównawcza otrzymanych związków. Najważniejsze wnioski płynące z zaprezentowanego materiału badawczego zebrane zostały w odrębnym rozdziale. Do pracy dołączone są trzy załączniki – pierwszy stanowią parametry krystalograficzne omawianych związków, drugi – parametry wiązań wodorowych, a trzeci – podsumowanie działalności naukowej i dydaktycznej. Pracę kończy bibliografia. Wykaz wszystkich zsyntezowanych i omówionych związków znajduje się na stronach dołączonych do pracy.

  • Synthesis and Cholinesterase Inhibitory Activity of N-Phosphorylated /N-Tiophosphorylated Tacrine
    • Maja Przybyłowska
    • Iwona Inkielewicz-Stępniak
    • Szymon Kowalski
    • Krystyna Dzierzbicka
    • Sebastian Demkowicz
    • Mateusz Daśko
    2020 Medicinal Chemistry

    Novel phosphorus and thiophosphorus tacrine derivatives were designed, synthesized and their biological activity and molecular modeling was investigated as a new potential anti-Alzheimer's disease (AD) agents. All new synthesized compound exhibited lower toxicity against neuroblastoma cell line (SH-SY5Y) in comparison with tacrine. Two analogues in the series, 7 and 9, demonstrated lack of cytotoxicity against hepatocellular cells (hepG2).

  • Synthesis and hydrogen evolving catalysis of a panchromatic photochemical molecular device
    • Johannes Habermehl
    • Nauroozi Djawed
    • Miłosz Martynow
    • Yury E. Vilk
    • Beranek Radim
    • Julien Guthmuller
    • Rau Sven
    2020 Sustainable Energy & Fuels

    A dinuclear hydrogen evolution photocatalyst [(tbbpy)2Os(tpphz)PtI2](PF6)2 (tbbpy = 4,4′-tert-butyl-2,2′-bipyridine; tpphz = tetrapyrido[3,2-a:2′,3′-c:2′′,3′′-h:2′′′,3′′′-j]phenazine) is synthesized in order to make use of the broader range of visible light absorption mitigated by the osmium center. In a first step, the activity of the complex for hydrogen evolution is investigated by evaluating the role of different electron donors (triethylamine (TEA), 1-benzyl-1,4-dihydronicotinamide (BNAH) and 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]-imidazole (BIH)). The highest photocatalytic activity (TON(H2) of 59) was observed for BIH as the electron donor. UV-vis investigations during catalysis with 470 nm (LED) irradiation show the rise of an absorption band at around 600 nm during catalysis, which indicates the reduction of the bridging ligand. Interestingly, broadband light excitation with wavelengths >450 nm induces no catalytic behavior. An intra-ligand charge transfer transition within the reduced tpphz moiety is hypothesized in order to rationalize the breakdown of the catalysis by broad band excitation.

  • Synthesis of CoFe2O4 Nanoparticles: The Effect of Ionic Strength, Concentration, and Precursor Type on Morphology and Magnetic Properties
    • Izabela Malinowska
    • Zuzanna Ryżyńska
    • Eryka Mrotek
    • Tomasz Klimczuk
    • Anna Zielińska-Jurek
    2020 Pełny tekst Journal of Nanomaterials

    The present study highlights the effect of metal precursor types (SO4 2¯, Cl¯, and NO3¯), their concentration, and the influence of ionic strength of reaction environment on the morphology, surface, and magnetic properties of CoFe2O4 particles. The magnetic nanoparticles were obtained by chemical coprecipitation in alkaline medium at increasing metal concentration in the range of 0.0425 mol·dm-3 to 0.17 mol·dm-3 and calcination temperature from 400°C to 800°C. It was found that the chemistry of precursors can be directly correlated with magnetic properties. The CoFe2O4 particles from metal sulphate precursors showed the highest saturation magnetization and the lowest coercivity. The adjustment of ionic strength in the range of 1.25–5M was achieved by adding an appropriate quantity of metal sulphates into aqueous solutions at a constant pH or by adding an appropriate quantity of NaClO5 under similar conditions. The average hydrodynamic size of CoFe2O4 increased from 46nm to 54 nm with increasing metal concentration and ionic strength. An explanation of magnetic properties, caused by ionic strength and metal concentration, is given based mainly on the reduction in repulsive forces at the particle interface and compensation of the double electric layer in the presence of anions. The observed coercivity was lower for the particles obtained in solutions with the highest ionic strength, whereas the concentration of metals and calcination temperature affected the saturation magnetization and morphology of the obtained cobalt ferrite particles.

  • Synthesis of compounds with C-P-P and C=P-P bond systems based on the phospha-Wittig reaction
    • Aleksandra Ziółkowska
    • Natalia Szynkiewicz
    • Jerzy Pikies
    • Łukasz Ponikiewski
    2020 Pełny tekst DALTON TRANSACTIONS

    A reactivity study of a β-diketiminate titanium(III) phosphanylphosphido complex [MeNacNacTi(Cl){η2-P(SiMe3)-PtBu2}] (1) towards ketones such as benzophenone, 9-fluorenone, acetophenone, cyclopentanone, cyclohexanone and cycloheptanone is reported. The reactions of 1 with aromatic ketones (without α-protons) directly lead to the Ti(III) complex [MeNacNacTi(μ2-Cl)(OSiMe3)] (5) as well as Ti(IV) complexes with the pinacol condensation product [MeNacNacTi(OSiMe3)(η2-pinacolate)] (3), and phosphanylphosphaalkenes Ph2C=P-PtBu2 (2) and (fluorenyl)C=P-PtBu2 (6), respectively. The reaction with acetophenone leads to the titanium(III) complex with the aldol condensation product as ligand [MeNacNacTi(Cl){OC{Me(Ph)}CH2(C=O)Ph] (8) and in parallel to phosphanylphosphaalkene (Ph)MeC=P-PtBu2 (9) and 5. The reactions of 1 with cyclic ketones (cyclopentanone and cyclohexanone) lead to Ti(III) complexes [{(ArN=C(Me)CHC(Me)=NAr)((CH2)4CO)}Ti(Cl){PtBu2-P(SiMe3)((CH2)4CO)}] (10) and [{(ArN=C(Me)CHC(Me)=NAr)((CH2)5CO)}Ti(Cl){PtBu2-P(SiMe3)((CH2)5CO)}] (11), which are formed via successive insertion of two molecules of ketone to one molecules of 1. The stability investigation of complexes 10 and 11 in a polar solvent (THF) revealed that under these conditions, the complexes decompose, resulting in titanium(III) complexes with aldol condensation products and the expected phosphanylphosphaalkenes (CH2)4C=P-PtBu2 (10a) and (CH2)5C=P-PtBu2 (11a). In the reaction of 1 with cycloheptanone only the Ti(III) complex with the aldol condensation product [MeNacNacTi(Cl){OC(CH2)5}CH(C=O)(CH2)6] (12) was isolated. The structures 3, 5, 8, 10, 11, 11b and 12 were characterized by X-ray spectroscopy, while all the phosphanylphosphaalkenes were characterized by NMR spectroscopy.

  • Synthesis of eosin modified TiO2 film with co-exposed {001} and {101} facets for photocatalytic degradation of para-aminobenzoic acid and solar H2 production
    • Javed Khan
    • Murtaza Sayed
    • Noor S. Shah
    • Sanaullah Khan
    • Yuxin Zhang
    • Grzegorz Boczkaj
    • Hasan Khan
    • Dionysios D. Dionysiou
    2020 APPLIED CATALYSIS B-ENVIRONMENTAL

    Owing to the increasing photosensitivity and DNA damage properties of para-aminobenzoic acid (PABA), concerns have been raised over the exposure of humans to PABA. Solar light-driven photocatalysis (SPC) provides a promising solution for the effective removal of organic pollutants especially when directed towards sulfate radical (SO4−) production. Herein, we have developed a sulfite-enhanced SPC using Eosin-Y sensitized TiO2/Ti film as a photocatalyst. The removal efficiency of PABA was enhanced by coupling Eosin-Y with TiO2/Ti film as revealed from 23.6 and 48.9 % PABA degradation by reference-TiO2/solar and Eosin-TiO2/solar, respectively. The apparent rate constant of PABA degradation by Eosin-TiO2 was improved by 4.7 times in presence of 5 mM sulfite. Interestingly, Eosin-TiO2 showed appreciable H2 production rate under visible light illumination. Solar/sulfite/Eosin-TiO2 system is a promising technology for environmental sustainability by using the renewable solar energy and air pollutants since sulfite is a waste from flue gas desulfurization process.

  • Synthesis of Titanium Dioxide via Surfactant-Assisted Microwave Method for Photocatalytic and Dye-Sensitized Solar Cells Applications
    • Adam Kubiak
    • Zuzanna Bielan
    • Aleksandra Bartkowiak
    • Elżbieta Gabała
    • Adam Piasecki
    • Maciej Zalas
    • Anna Zielińska-Jurek
    • Marcin Janczarek
    • Katarzyna Siwińska-Ciesielczyk
    • Teofil Jesionowski
    2020 Pełny tekst Catalysts

    In this study, titania nanoparticles were obtained using the microwave-assisted technique. Moreover, different surfactants (PEG (Mn = 400), Pluronic P123 and Triton X−100) were used during the synthesis in order to determine their impact on the crystallinity and morphology of the final products. Subsequently, techniques such as XRD, SEM and TEM (performed in high contrast and high-resolution mode), diffuse reflectance spectroscopy (DRS), low temperature N2 sorption (BET model), FTIR and TGA were carried out. Based on the crystallinity analysis of the obtained materials, it was established that the addition of surfactants results in greater (PEG and Triton X−100) or smaller (Pluronic P123) average crystallite size. The main purpose of this study was to use the synthesized nanomaterials in the photodegradation process (in the UV light range) of the model organic pollutants – phenol (20 mg/L) and etodolac (15 mg/L). Furthermore, it was also pointed out that the dye-sensitized solar cells can be a second application for the synthesized titania nanomaterials. The photo-oxidation and photovoltaic tests have shown that the titanium dioxide obtained using the surfactant-assisted microwave method is characterized not only by better photodegradation efficiency of phenol and etodolac, but also by higher photocurrent density compared to the reference titania samples—the pristine TiO2 and commercial P25.

  • Synthesis, structural characterization, and thermal properties of Ca‐ and La‐doped soda‐lime glasses by laser melting
    • Sharafat Ali
    • Natalia Wójcik
    • Bo Jonson
    • Efstratios Kamitsos
    • Xinghua Li
    • Jian Luo
    • Doris Möncke
    2020 Pełny tekst International Journal of Applied Glass Science

    Laser melting techniques have been used in the preparation of unconventional glass compositions with high melting temperatures. Thus, we wanted to test the feasibility of using a CO2 laser in the preparation of nitrogen-rich oxynitride glasses and nitride silicate glasses. Melting from oxides and metallic raw materials, we wanted to study first glass formation and possible evaporation losses of the glass components. Two glass series were prepared and studied for their structure and thermal properties, one with Ca2+- and a higher melting La3+-doped soda-lime-silicate (SLS) series. In less than 3minutes of laser melting, spheres of up to 6mm diameter were successfully fabricated. The obtained glass samples were homogeneous and transparent in the visible region. X-ray diffraction and Raman spectroscopic analysis confirmed the amorphous nature of the synthesized samples. Sodium losses increase as calcium is added to the soda-lime-silicate glass. As expected, increasing Ca2+ or La3+ addition lead to increased depolymerization of the silicate network. Moreover, the increases in Tg with the addition of Ca2+ or La3+ ions indicating strengthening of the soda-lime-silicate glass by increasing strength of the M-O bonds of divalent and trivalent ions over monovalent sodium ions, weak Na-O bonds also resulting in significant evaporation loss during the short laser melting times. The thermal stability decreases upon addition of Ca2+ or La3+ ions to the soda-lime-silicate glasses.

  • Synthesis, structure and physical properties of new intermetallic spin glass-like compounds RE2PdGe3 (RE = Tb and Dy)
    • Leszek Litzbarski
    • Tomasz Klimczuk
    • Michał Winiarski
    2020 Pełny tekst JOURNAL OF PHYSICS-CONDENSED MATTER

    New intermetallic compounds Tb2Pd1.25Ge2.75 and Dy2Pd1.25Ge2.75 have been synthesized using the arc-melting method. The crystallographic structure and magnetic, electronic transport, and thermal properties are reported. The crystal structure obtained from powder x-ray diffraction analysis suggests that these compounds crystallize in the AlB2-type structure (space group P6/mmm, no. 191) with lattice parameters a  =  4.228 53(5)/4.230 54 (2) Å and c  =  3.942 25(9)/3.945 52(5) Å for the compounds with Tb and Dy respectively. The ac and dc magnetic susceptibility studies reveal spin-glass like behavior, with freezing temperature T f  =  10.5 K for Tb2Pd1.25Ge2.75 and 4.5 K for Dy2Pd1.25Ge2.75. These data are in good agreement with the heat capacity measurements.

  • Synthesis, thermal, structural and electrical properties of vanadium-doped lithium-manganese-borate glass and nanocomposites
    • Agata Jarocka
    • Przemysław Michalski
    • Jacek Ryl
    • Marek Wasiucionek
    • Jerzy Garbarczyk
    • Tomasz Pietrzak
    2020 Pełny tekst IONICS

    A glassy sample with a nominal formula LiMn1−3x/2VxBO3 (where x = 0.05) was synthesised using the melt-quenching method. Material was characterised by differential thermal analysis (DTA), X-ray diffactometry (XRD) at room temperature and as a function of temperature (HT-XRD), X-ray photoelectron spectroscopy (XPS), impedance spectroscopy (IS) and scanning electron microscopy (SEM). Dependences of glass transition and crystallisation temperatures on the heating rate in DTA experiments were determined. The initial value of electrical conductivity of the glass was 1.4×10−15 Scm−1. It was significantly increased by a proper thermal nanocrystallisation. The maximum value was higher by 6 orders of magnitude and reached 2.6×10−9 Scm−1 at room temperature. Expected crystalline phases (i.e. monoclinic and hexagonal LiMnBO3) upon heating were identified and assigned to thermal events observed with DTA. Microstructure of nanocrystalline samples observed by SEM revealed nanocrystalline grains noticeably smaller than 100 nm. Results explaining nanocrystallisation process are coherent.

  • Synthetic strategies in construction of organic low molecular-weight carrier-drug conjugates
    • Andrzej Skwarecki
    • Michał Nowak
    • Maria Milewska
    2020 Pełny tekst BIOORGANIC CHEMISTRY

    Inefficient transportation of polar metabolic inhibitors through cell membranes of eukaryotic and prokaryotic cells precludes their direct use as drug candidates in chemotherapy. One of the possible solutions to this problem is application of the ‘Trojan horse’ strategy, i.e. conjugation of an active substance with a molecular carrier of organic or inorganic nature, facilitating membrane penetration. In this work, the synthetic strategies used in rational design and preparation of conjugates of bioactive agents with three types of organic low molecular-weight carriers have been reviewed. These include iron-chelating agents, siderophores and cell-penetrating peptides. Moreover, a less known but very promising “molecular umbrella” conjugation strategy has been presented. Special attention has been paid on appropriate linking strategies, especially these allowing intracellular drug release after internalisation of a conjugate.

  • Synthetic strategies in construction of organic macromolecular carrier–drug conjugates
    • Andrzej Skwarecki
    • Michał Nowak
    • Maria Milewska
    2020 ORGANIC & BIOMOLECULAR CHEMISTRY

    Many metabolic inhibitors, considered potential antimicrobial or anticancer drug candidates, exhibit verylimited ability to cross the biological membranes of target cells. The restricted cellular penetration ofthose molecules is often due to their highhydrophilicity. One of the possible solutions to this problem is aconjugation of an inhibitor with a molecular organic nanocarrier. The conjugate thus formed should beable to penetrate the membrane(s) by direct translocation, endocytosis or active transport mechanismsand once internalized, the active component could reach its intracellular target, either after release fromthe conjugate or in an intact form. Several such nanocarriers have been proposed so far, including macro-molecular systems, carbon nanotubes and dendrimers. Herein, we present a comprehensive review of thecurrent status of rational design and synthesis of macromolecular organic nanocarrier-drug conjugates,with special attention focused on the mode of coupling of a nanocarrier moiety with a“cargo”moleculethrough linking fragments of non-cleavable or cleavable type.

  • System architecture of an INSPIRE-compliant green cadastre system for the EU Member State of Poland
    • Agnieszka Dawidowicz
    • Marcin Kulawiak
    • Elżbieta Zysk
    • Katarzyna Kocur-Bera
    2020 Pełny tekst Remote Sensing Applications: Society and Environment

    In response to the need for a sustainable agricultural policy, which would support activities such as decision making in precise agriculture and mitigation of crop threats, a concept agricultural information system was developed for the area of Poland. This innovative concept, called Green Cadastre (GC), proposes to create a uniform system designed for use on a national scale by both state administration as well as local farmers. This article presents the concept system architecture of the proposed GC solution. The system architecture takes into account the current state of the INSPIRE Spatial Data Infrastructure, the previously established requirements for a GC system, as well as an analysis of current trends in geospatial IT. The proposed solution combines open data exchange protocols with Open Source technologies and current international SDI standards in order to provide a flexible and cost-effective solution.

  • System for monitoring road slippery based on CCTV cameras and convolutional neural networks
    • Dariusz Grabowski
    • Andrzej Czyżewski
    2020 Pełny tekst JOURNAL OF INTELLIGENT INFORMATION SYSTEMS

    The slipperiness of the surface is essential for road safety. The growing number of CCTV cameras opens the possibility of using them to automatically detect the slippery surface and inform road users about it. This paper presents a system of developed intelligent road signs, including a detector based on convolutional neural networks (CNNs) and the transferlearning method employed to the processing of images acquired with video cameras. Based on photos taken in different light conditions by CCTV cameras located at the roadsides in Poland, four network topologies have been trained and tested: Resnet50 v2, Resnet152 v2, Vgg19, and Densenet201. The last-mentioned network has proved to give the best result with 98.34% accuracy of classification dry, wet, and snowy roads.

  • System monitoringu rozdzielnic kampusu Politechniki Gdańskiej
    • Krzysztof Kwasigroch
    • Maciej Łukaszewicz
    • Ireneusz Mosoń
    2020 Pełny tekst Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej

    W artykule opisano koncepcję, realizację programową oraz stanowisko testowe systemu monitoringu rozdzielnic kampusu Politechniki Gdańskiej. Zaproponowano realizację sprzętową oraz opracowano realizację programową systemu monitoringu rozdzielnic dla dwóch budynków: Gmachu Głównego i Centrum Obsługi Technicznej. Ważną cechą opracowanego rozwiązania jest jego skalowalność, gdyż docelowo system monitoringu będzie obejmował wszystkie rozdzielnice kampusu Politechniki Gdańskiej. Do akwizycji sygnałów z aparatów elektrycznych przewidziano sterowniki programowalne easyE4, które będą zainstalowane w rozdzielnicach poszczególnych budynków. Funkcję nadrzędną w systemie monitoringu będzie pełnił sterownik programowalny XC-303. Jego zadaniem będzie zbieranie sygnałów ze wszystkich sterowników easyE4. Sterownik XC-303 będzie znajdował się w budynku Centrum obsługi Technicznej, oraz docelowo na serwerze w tym budynku zostanie zainstalowana opracowana wizualizacja. Wszystkie przewidziane w systemie monitoringu funkcje zostały uruchomione i przetestowane na zbudowanym w tym celu stanowisku testowym. Do programowania sterowników easyE4 wykorzystano środowisko programistyczne easySoft 7, a program na sterownik XC-303 opracowano w środowisku programistycznym CODESYS 3. Wizualizacja została opracowana w środowisku programistycznym Galileo 10. Do komunikacji pomiędzy urządzeniami systemu monitoringu wykorzystano protokół Modbus TCP. System monitoringu będzie wykorzystywał uczelnianą sieć komputerową Politechniki Gdańskiej.

  • Systematic review examining the evidence for impact of school policies on physical activity
    • Kevin Volf
    • Liam Kelly
    • Enrique García Bengoechea
    • Anna Gobis
    • Jeroen Lakerveld
    • Joanna Żukowska
    • Peter Gelius
    • Sven Messing
    • Sarah Forberger
    • Catherine Woods
    2020 EUROPEAN JOURNAL OF PUBLIC HEALTH

    Background Epidemiological evidence has demonstrated that physical activity can have substantive health benefits for children and young people. The 'Policy Evaluation Network' is a multi-disciplinary research network across 7 European countries and New Zealand aimed at building capacity and evaluating the level of impact of policy interventions for promoting healthy lifestyles. The Toronto Charter identified 'whole-of-school' programmes as one of seven key investments for promotion of PA. This paper presents results of a SLR, designed to assess the level of evidence for policies within the school setting that contribute directly or indirectly to increasing PA. Methods Researchers searched six online databases for scientific literature regarding PA policy interventions in the school setting using key concepts of policy, school, PA and evaluation. Risk of bias will be assessed with tools appropriate to the design of the studies considered. Evidence of actual or potential positive PA outcomes arising directly or indirectly from policy actions will be catalogued. Results Preliminary searches identified 2327 unique scientific articles. 1938 (83.3%) were excluded on first reading and 189 (8.8%) were included for full text analysis. Initial findings suggest that organisational policies, for example avoiding overcrowding in playgrounds during school breaks, may be a promising policy action. Detailed analysis revealing other potential policy actions supported by evidence will be presented (SLR in progress). Conclusions Preliminary findings suggest that few studies link policy actions in the school setting to PA outcomes. However, studies that have investigated the effects of changes to the school environment on PA levels may provide evidence for policy actions. Preliminary recommendations include strengthening the evidence base for school-based PA policy by supporting studies into the effects of particular policy or legislative changes on PA outcomes.

  • Systematic Water Uptake Energetics of Yttrium-Doped Barium Zirconate—A High Resolution Thermochemical Study
    • Mayra Goncalves
    • Aleksandra Mielewczyk-Gryń
    • Pardha Saradhi Maram
    • Łukasz Kryścio
    • Maria Gazda
    • Alexandra Navrotsky
    2020 Pełny tekst Journal of Physical Chemistry C

    A combination of surface area analyzer and microcalorimetry was employed to investigate the in situ water uptake energetics and the mechanism of proton incorporation in yttrium-doped barium zirconate in the temperature range 200–400 °C. The BaZr1–xYxO3 solid solutions are made with variable yttrium content (x = 10, 20, and 30 mol %) by a controlled oxidant-peroxo synthesis method. The water uptake increases as the partial pressure of water increases; however, no saturation in the hydration isotherm is observed, implying further reaction at higher pH2O. The results suggest three distinct regions of hydration energies as a function of water content. The first water uptake enthalpy values showed high exothermicity, −140, −158, and −157 kJ mol–1 for BaZr1–xYxO3 (x = 10, 20, and 30 mol %), respectively, at 400 °C, and the strong exothermic contribution supports the dissociative incorporation of water. The stepwise in situ hydration energetics is essential to understand the mechanisms of water incorporation and the role of H2O uptake in transport properties.

  • Systems engineering approach to functional safety and cyber security of industrial critical installations
    • Kazimierz Kosmowski
    2020 Pełny tekst

    This chapter addresses the systems engineering approach to integrated functional safety and cybersecurity analysis and management regarding selected references, standards and requirements concerning critical installations and their industrial automation and control system (IACS). The objective is to mitigate the vulnerability of industrial installations that include the information technology (IT) and the operational technology (OT) to reduce relevant risks. This approach includes verifying the safety integrity level (SIL) of defined safety functions, and then to check the level obtained taking into account the security assurance level (SAL) of particular domain, such as a safety related control system (SRCS), in which given safety function is to be implemented. The SAL is determined based on a vector of fundamental requirements (FRs). The method proposed uses defined risk graphs for the individual and/or the societal risk, and relevant risk criteria, for determining the SIL required of given safety function, and probabilistic models to verify the SIL achievable for the SRCS architecture to be designed and then implemented in an industrial installation.

  • Systems engineering approach to functional safety and cyber security of industrial critical installations
    • Kazimierz Kosmowski
    2020

    This chapter addresses the systems engineering approach to integrated functional safety and cybersecurity analysis and management regarding selected references, standards and requirements concerning critical installations and their industrial automation and control system (IACS). The objective is to mitigate the vulnerability of industrial installations that include the information technology (IT) and the operational technology (OT) to reduce relevant risks. This approach includes verifying the safety integrity level (SIL) of defined safety functions, and then to check the level obtained taking into account the security assurance level (SAL) of particular domain, such as a safety related control system (SRCS), in which given safety function is to be implemented. The SAL is determined based on a vector of fundamental requirements (FRs). The method proposed uses defined risk graphs for the individual and/or the societal risk, and relevant risk criteria, for determining the SIL required of given safety function, and probabilistic models to verify the SIL achievable for the SRCS architecture to be designed and then implemented in an industrial installation.

  • Szkodliwe związki powstające wskutek przemian sacharydów
    • Hanna Staroszczyk
    2020

    W rozdziale opisano zagadnienia związane ze zdrowotnymi aspektami spożywania sacharydów, scharakteryzowano alternatywne substancje słodzące oraz przedstawiono interakcje sacharydów z innymi składnikami żywności.

  • Świat i jego ekosystem mobilny – dane statystyczne i perspektywy rozwoju
    • Józef Woźniak
    2020

    Główną uwagę położono na szeroką prezentację technologii informacyjno-komunikacyjne, które, jak się powszechnie oczekuje, będą, podobnie jak w ostatnich dwóch dziesięcioleciach, istotnym elementem rozwoju i katalizatorem zmian zachodzących we wszystkich obszarach bazujących na wymianie, przetwarzaniu, przechowywaniu i udostępnianiu informacji cyfrowych, wpływając na rozwój i kreowanie różnorodnych ekosystemów cyfrowych. zaprezentowano sposoby wdrażania technologii piątej generacji (5G), wskazując fazy w implementacji i kamienie milowe w rozwoju systemów i sieci 5G w Polsce i na świecie. Uwagę poświęcono też koncepcjom IoT oraz nowym, perspektywicznym technologiom sieciowym. Zaprezentowano też szkicowo problemy odnoszące się do usług chmurowych.