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  • Geographical and chronological knowledge in teaching the history of architecture
    • Aleksander Piwek
    • Tomasz Jażdżewski
    • Piotr Samól
    2020 Pełny tekst World Transactions on Engineering and Technology Education

    The subject of this article is the analysis of examination results from the course, the History of Polish Architecture. These Bachelor studies present the political, economic and cultural issues of medieval and early modern architecture, and their changes over time. Basic knowledge of the administrative division and historical regions is needed for a proper understanding of the regional diversity of cultural heritage monuments in Poland. One of the tasks of the final test is to identify from pictures ten historic buildings and to provide the name, function, time of creation, architectural style, author, city and region of the pictures. Analysis of the answers shows that many students, despite their good knowledge of architecture, have problems with the correct location of not only small- and medium-sized cities, but also the largest cities and the capital. Another issue discussed in this article is the problem of students recognising architectural styles and the time of their occurrence in various regions.

  • GEOINFORMATYCZNE NARZĘDZIE DO BADANIA ZASIĘGU LOKALNYCH STACJI NADAWCZYCH RADIOFONII CYFROWEJ DAB+
    • Przemysław Falkowski-Gilski
    • Ryszard J. Zieliński
    • Marek Kulawiak
    • Marcin Kulawiak
    2020 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    Kwestia zapewnienia odpowiedniego pokrycia sygnałem multipleksu jest kluczowym aspektem zarówno dla nadawców publicznych jak i prywatnych, a w szczególności lokalnych stacji zainteresowanych procesem cyfryzacji. W pracy przedstawiono geoinformatyczne narzędzie, umożliwiające badanie zasięgu lokalnych stacji nadawczych radiofonii cyfrowej DAB+. Analizę przeprowadzono dla pionierskiej w Polsce stacji LocalDAB we Wrocławiu. Wyniki opisanych prac mogą być pomocne dla naukowców i profesjonalistów działających we wspomnianej dziedzinie.

  • Geokompozyty drenażowe w odwodnieniach drogowych i kolejowych
    • Remigiusz Duszyński
    2020 Magazyn Autostrady

    Zagadnienie zagospodarowania wód opadowych i gruntowych w rejonie konstrukcji drogowych i kolejowych stanowi istotny element bezpiecznej i efektywnej eksploatacji tych obiektów. Odpowiednie wykorzystanie geokompozytów drenażowych zapewnia bezproblemową pracę konstrukcji oraz właściwą ochronę przed uszkodzeniami wynikającymi z niekontrolowanego oddziaływania wody.

  • Geometry of cycling track
    • Maciej Solarczyk
    2020 Pełny tekst Budownictwo i Architektura

    The paper describes the problems related to shaping of the geometry of the cycling track. The method of selection of the angle at the track curve is presented. Issues related to the selection of the appropriate transition curve and the superelevation section along the transition curve are presented. Reference to the recommendations presented in the literature and scientific papers has been made. Special attention to the need of consideration of the subjective feelings of the cyclist is paid. The paper describes the guidelines of the International Cycling Union (UCI) on shaping the geometry of the cycling track.

  • Geospatial Coverage and Signal Quality Measurements of Terrestrial DAB+ Network in Northern Poland
    • Przemysław Falkowski-Gilski
    • Marek Kulawiak
    • Marcin Kulawiak
    2020

    Modern signal coverage maps are prepared based on industry-standard radio propagation models, which take into account a number of parameters, including: type of antenna, distance from the transmitter, type of terrain, etc. However, such simulations are prone to location-specific inaccuracies, and should be verified with in-situ measurements. This paper presents results of a field test of a terrestrial DAB+ (Digital Audio Broadcasting plus) network in the metropolitan area of the Tricity, the largest agglomeration in Northern Poland. Obtained results were compared to previously generated radio signal coverage maps. The study shown that terrain topology has a profound impact on signal strength, and should be more accurately implemented in coverage modeling, particularly in order to provide a stable and reliable high-quality connection.

  • Geosyntetyki w funkcji zbrojenia
    • Angelika Duszyńska
    2020 Geoinżynieria, Drogi, Mosty, Tunele

    Wymiarowanie geosyntetyków pełniących funkcję zbrojenia gruntu nasypowego polega na dobraniu wyrobów spełniających stosowne warunki stateczności zewnętrznej i wewnętrznej konstrukcji, które zagwarantują zachowanie integralności konstrukcji i bezpieczną współpracę zbrojenia oraz gruntu w projektowanym okresie użytkowalności. Prawidłowe zaprojektowanie budowli ziemnej zbrojonej geosyntetykami wymaga szczegółowych i rzetelnych danych dotyczących zbrojenia. Należą do nich przede wszystkim: - wytrzymałość geosyntetyku na rozciąganie z uwzględnieniem pełzania w projektowym okresie użytkowania, - wpływ uszkodzeń w trakcie wbudowania zbrojenia i zagęszczania gruntu (kruszywa), - wpływ oddziaływań środowiskowych itp.

  • GIUSEPPE VOLPI. IL GRANDE MEDIATORE TRA ISTITUZIONI, POLITICA ED ECONOMIA
    • Luciano Segreto
    2020 Studi Storici

    Giuseppe Volpi di Misurata represented a mediation point between different interests both in the economic field and in the complex national – but also regional and local – political balance that long underpinned the fascist regime. This article intends to revisit this figure between the 1920s and the Second World War. The attempt will be made to identify, through an approach that will be chronological and thematic, the passages that led Volpi to embody the ideal prototype of the mediator between different economic and political interests. In his relationship with the institutions and with the fascist government the paper will identify the elements that made him – to the eyes of many, in Italy as well as abroad – a potential successor to Mussolini in the event of a regime crisis.

  • Global Optimization for Recovery of Clipped Signals Corrupted With Poisson-Gaussian Noise
    • Arthur Marmin
    • Anna Węsierska
    • Marc Castella
    • Jean-Christophe Pesquet
    2020 IEEE SIGNAL PROCESSING LETTERS

    We study a variational formulation for reconstructing nonlinearly distorted signals corrupted with a Poisson-Gaussian noise. In this situation, the data fidelity term consists of a sum of a weighted least squares term and a logarithmic one. Both of them are precomposed by a nonlinearity, modelling a clipping effect, which is assumed to be rational. A regularization term, being a piecewise rational approximation of the ℓ0 function provides a suitable sparsity measure with respect to a preset linear operator. We propose a global optimization approach for such a problem. More specifically, it is first transformed into a generalized moment problem by introducing some auxiliary variables. Then, a hierarchy of semidefinite programming relaxations is built. Numerical examples show the good performance of the proposed approach.

  • Golden artefacts, resin figurines, body adhesives and tomb sediments from the pre-Columbian burial site El Caño (Gran Coclé, Panamá): tracing organic contents using molecular archaeometry
    • Joeri Kaal
    • María Martín Seijo
    • César Oliveira
    • Ewa Wagner-Wysiecka
    • Victoria E. McCoy
    • Mónica M. Solórzano Kraemer
    • Alexander Kerner
    • Philip Wenig
    • Carlos Mayo
    • Julia Mayo
    2020 Pełny tekst Journal of Archaeological Science

    This research aimed to determine the origin of organic residues from funerary contexts in the El Ca~no settlement (Gran Cocl�e area, Panam�a, Central America) by means of multiple molecular probing techniques (GC-MS of organic solvent extracts and pyrolysis-GC-MS, THM-GC-MS and FTIR of solid samples). The samples include particles of precious resin figurines, fillings of golden objects, tomb sediments, plant exudates from extant plants (reference collection) and other reference materials (amber). The labdane diterpene fingerprints (eperuic, isoozic, copalic and kolavenic acids and derivatives) of the resin figurines, a resinous bead and several other samples, suggest that they were composed primarily of Hymenaea resin. Besides traditional interpretation approaches (visual comparison of chromatograms and relative proportions data), we used a novel OpenChrom® application that resolves complex pyrolysis chromatograms by screening data from archaeological samples for marker products defined on the basis of a reference collection (ChromIdent). ChromIdent confirmed the Hymenaea origin of many samples and also Burseraceae resin was identified in some samples, which is present as a minor ingredient in resin figurines (indicative of mixing practices) and as the dominant resin in tomb sediment that had been in contact with the corpses (indicating balsaming practices). The degree of polymerization of the Hymenaea resin was higher than for extant resin but diagenetic alteration (especially condensation of cyclic moieties) was much smaller than for amber, implying that the manufacturers used resin (or copal), not amber. These results were confirmed by FTIR, which allowed identification of non-fossil Hymenaea resin as the main constituent of one of the resin figurines. Several golden object infillings contained wax derivatives, probably beeswax, accompanied by various types of plant resin, which may well indicate the use of meliponines’ cerumen for manufacturing (lost-wax casting). The findings highlight the potential of complementary molecular techniques to resolve questions on materials and manufacturing of archaeological artefacts, and the need for crosscomparison of molecular and ethnographic information in the study of archaeobotanical remains and the processes involved in their management.

  • Graph classes generated by Mycielskians
    • Mieczysław Borowiecki
    • Piotr Borowiecki
    • Ewa Drgas-Burchardt
    • Elżbieta Sidorowicz
    2020 Pełny tekst Discussiones Mathematicae Graph Theory

    In this paper we use the classical notion of weak Mycielskian M'(G) of a graph G and the following sequence: M'_{0}(G) =G, M'_{1}(G)=M'(G), and M'_{n}(G)=M'(M'_{n−1}(G)), to show that if G is a complete graph oforder p, then the above sequence is a generator of the class of p-colorable graphs. Similarly, using Mycielskian M(G) we show that analogously defined sequence is a generator of the class consisting of graphs for which the chromatic number of the subgraph induced by all vertices that belong to at least one triangle is at most p. We also address the problem of characterizing the latter class in terms of forbidden graphs.

  • Green Chromatography: State-of-the-art, Opportunities and Future Perspectives
    • Justyna Płotka-Wasylka
    • Magdalena Fabjanowicz
    • Kaja Kalinowska
    • Jacek Namieśnik
    2020

    It is well known that chromatographic procedures could have a significant impact on the environment if laboratory practice is not in line with the principles of green analytical chemistry (GAC). However, chromatographic techniques have the potential to be greener in all steps of the analysis. The approaches used to make chromatographic separations greener differ depending on the type of chromatographic method. This chapter considers the ways in which chromatography can become greener. Liquid and gas chromatography are compared from the GAC point of view. In addition, the importance of miniaturization in sample preparation and chromatographic separations is pointed out. On-line process analysers and portable chromatographs are also discussed.

  • Green thermoplastic poly(ether-urethane)s – synthesis, chemical structure and selected properties investigation
    • Paulina Kasprzyk
    • Kamila Błażek
    • Paulina Parcheta
    • Janusz Datta
    2020 Pełny tekst Polimery

    This work aimed to characterize the effect of the monomers chemical structure on the selected properties of the green thermoplastic poly(ether-urethane)s. During synthesis two types of polyether biopolyols, 4,4′-diphenylmethane diisocyanate and bio-based 1,3-propanediol were employed. Materials were synthesized with the use of two step method and two different prepolymers, which were mixed together in equimolar quantities. Obtained materials were characterized by spectroscopic method, size exclusion chromatography, thermal, static mechanical and melt flow index tests. It was confirmed that the prepolymers mixture has an effect on the thermal stability and selected properties of synthesized green thermoplastic poly(ether-urethane)s.

  • Grimm Grass 1 (Słówka Grimmów)
    • Krzysztof Wróblewski
    2020

    Krzysztof Wróblewski | Eksperyment: Ekslibris - ekslibris do powieści „Słówka Grimmów” Güntera Grassa LINK DO PREZENTACJI EKSLIBRISU → https://youtu.be/823ryLQzxas W swoim ekslibrisie Krzysztof Wróblewski sięgnął po technikę graficzną linorytu. Dzięki niej artysta osiągnął efekt powtarzalnego, dynamicznego znaku-plamy, który stanowi kwintesencję wypowiedzi z pogranicza sztuk wizualnych i literatury. Zainspirowany poezją konkretną, gdzie rytm, autonomia słowa, gry językowe i eksperymenty formalne odgrywają kluczową rolę, Wróblewski bardzo silnie nawiązał także do swojego własnego rozpoznawalnego sposobu wypowiedzi twórczej. Polega on na przenikaniu się form, równorzędności abstrakcji i rzeczywistości, wizualnych zagadkach, zacieraniu znaczeń i kreowaniu nowych, odkrywaniu i zakrywaniu wizerunków i treści. Jest w nim sporo formalnej precyzji a jednocześnie przypadkowości, gier logicznych i semantycznych, fascynacji geometrią, rozważań z pogranicza estetyki i tekstu. Stawiane przez Wróblewskiego znaki działają jako całość, ale także stają się indywidualnymi bytami. Wizualizują analogie i różnice pomiędzy poszczególnymi słowami zaczerpniętymi z języka polskiego i niemieckiego, a także stanowią analizę rytmu i struktury nazwisk: Grass i Grimm. Artysta bowiem zmierzył się z jedną z najtrudniejszych powieści Grassa, jaką są „Słówka Grimmów”. Cała książka stanowi eksperyment werbalny, nieustanny pojedynek treści i formy. Każdy z rozdziałów inspirowany jest kolejną literą alfabetu, rozpoczynającą słowa, z których skomponowana jest jego zawartość. Stąd też powieść ta uznawana jest przez wielu tłumaczy za nieprzekładalną na inne języki. Ewidentnym wyjątkiem jest tu język sztuki, sprzyjający eksperymentowaniu i skomplikowanym uwikłaniom zachodzącym pomiędzy dyscyplinami twórczymi.

  • Grimm Grass 2 (Słówka Grimmów)
    • Krzysztof Wróblewski
    2020

    Krzysztof Wróblewski | Eksperyment: Ekslibris - ekslibris do powieści „Słówka Grimmów” Güntera Grassa LINK DO PREZENTACJI EKSLIBRISU → https://youtu.be/823ryLQzxas W swoim ekslibrisie Krzysztof Wróblewski sięgnął po technikę graficzną linorytu. Dzięki niej artysta osiągnął efekt powtarzalnego, dynamicznego znaku-plamy, który stanowi kwintesencję wypowiedzi z pogranicza sztuk wizualnych i literatury. Zainspirowany poezją konkretną, gdzie rytm, autonomia słowa, gry językowe i eksperymenty formalne odgrywają kluczową rolę, Wróblewski bardzo silnie nawiązał także do swojego własnego rozpoznawalnego sposobu wypowiedzi twórczej. Polega on na przenikaniu się form, równorzędności abstrakcji i rzeczywistości, wizualnych zagadkach, zacieraniu znaczeń i kreowaniu nowych, odkrywaniu i zakrywaniu wizerunków i treści. Jest w nim sporo formalnej precyzji a jednocześnie przypadkowości, gier logicznych i semantycznych, fascynacji geometrią, rozważań z pogranicza estetyki i tekstu. Stawiane przez Wróblewskiego znaki działają jako całość, ale także stają się indywidualnymi bytami. Wizualizują analogie i różnice pomiędzy poszczególnymi słowami zaczerpniętymi z języka polskiego i niemieckiego, a także stanowią analizę rytmu i struktury nazwisk: Grass i Grimm. Artysta bowiem zmierzył się z jedną z najtrudniejszych powieści Grassa, jaką są „Słówka Grimmów”. Cała książka stanowi eksperyment werbalny, nieustanny pojedynek treści i formy. Każdy z rozdziałów inspirowany jest kolejną literą alfabetu, rozpoczynającą słowa, z których skomponowana jest jego zawartość. Stąd też powieść ta uznawana jest przez wielu tłumaczy za nieprzekładalną na inne języki. Ewidentnym wyjątkiem jest tu język sztuki, sprzyjający eksperymentowaniu i skomplikowanym uwikłaniom zachodzącym pomiędzy dyscyplinami twórczymi.

  • Ground Tire Rubber Modified by Ethylene-Vinyl Acetate Copolymer: Processing, Physico-Mechanical Properties, Volatile Organic Compounds Emission and Recycling Possibility
    • Łukasz Zedler
    • Paulina Burger
    • Shifeng Wang
    • Krzysztof Formela
    2020 Pełny tekst Materials

    Ground tire rubber (GTR) was reclaimed and modified with 10 phr of ethylene-vinyl acetate copolymer via low-temperature extrusion process. Processing, physico-mechanical properties, volatile organic compounds emission, and recycling possibility were investigated. In order to better understand the impact of used modifiers, their efficiency was compared with transpolyoctenamer, which is an additive that is commercially dedicated to waste rubber recycling. The results showed that a relatively small amount of ethylene-vinyl acetate copolymer improves the mechanical properties of modified reclaimed GTR and also allows further recycling by multiple processing without the deterioration of performance after three cycles.

  • Guest Editorial
    • Jakub Szczepański
    2020 Pełny tekst World Transactions on Engineering and Technology Education

    Architectural Education

  • Heavy Metals in a High Arctic Fiord and Their Introduction with the Wastewater: A Case Study of Adventfjorden-Longyearbyen System, Svalbard
    • Agnieszka Kalinowska
    • Małgorzata Szopińska
    • Stanisław Chmiel
    • Magdalena Kończak
    • Żaneta Polkowska
    • Wojciech Artichowicz
    • Katarzyna Jankowska
    • Aga Nowak
    • Aneta Łuczkiewicz
    2020 Pełny tekst Water

    Longyearbyen is the largest settlement on Svalbard archipelago, with 2400 permanent residents and approximately 150,000 tourists visiting every year. The city annually releases approximately 285,000 m3 of untreated wastewater to the nearby Adventfjorden. To date, the environmental impact of this continuous input has been studied mainly regarding the sediments and benthic fauna in the fiord. Here, we present results from a study of raw wastewater entering Adventfjorden as well as heavy metals concentrations in the water column within the fjord itself. Two surveys were carried out in summer and autumn season 2018, to establish physical and chemical properties of water at various locations. Trace elements (V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Hg, As, Cd, Pb, U), total suspended solids (TSS) and total organic carbon (TOC) were measured. Our results show that Longyearbyen’s raw wastewater introduces low concentrations of heavy metals to the fiord, but due to the growing number of inhabitants and tourists, it should be monitored to avoid degradation of Adventfjorden ecosystem

  • Henryk Hadrian i jego praca w Instytucie Elektrotechniki i na Politechnice Gdańskiej
    • Witold Parteka
    2020 Pełny tekst Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej

    W artykule przedstawiono sylwetkę Henryka Hadriana, absolwenta Wydziału Budowy Maszyn i Elektrotechniki politechniki w Gdańsku z 1935 roku. W latach 1945-1950 pracował w Zjednoczeniu Stoczni Polskich w Gdańsku, a w latach 1951- 1975 w gdańskim oddziale Instytutu Elektrotechniki, gdzie zorganizował i kierował działem elektrotechniki okrętowej, a także w centrali w Warszawie. Od przejścia na emeryturę w 1975, pełnił do 1990 roku funkcję rzecznika patentowego i konsultanta z zakładami pracy do spraw patentów i wdrożeń na Wydziale Elektrycznym Politechniki Gdańskiej .

  • Hierarchical MnO2 nanoflowers blooming on 3D nickel foam: A novel micro-macro catalyst for peroxymonosulfate activation
    • Ruixia Yuan
    • Zhongqiu Jiang
    • Zhaohui Wang
    • Simeng Gao
    • Zhanjian Liu
    • Meiling Li
    • Grzegorz Boczkaj
    2020 JOURNAL OF COLLOID AND INTERFACE SCIENCE

    In this work, birnessite-type δ-MnO2 nanoflowers were uniformly deposited on 3D nickel foam (NF) by one-step hydrothermal route for high-efficient activation of peroxymonosulfate (PMS) towards degradation of acid orange 7 (AO7). High specific surface area, large pore volume and 3D hierarchical structure promotes the mass and electron transfer for great catalytic activity. Low reaction energy barrier (Ea=27.5 kJ/mol) and outstanding reusability with extremely low manganese leaching during recycling (< 0.06 mg/L) was achieved due to the 3D hierarchical structure which could effectively avoid the agglomeration of nano-sized MnO2. SO4•- was confirmed to be the predominant reactive species for AO7 decomposition by electron spin resonance and quenching tests. The synergistic catalytic mechanism of MnO2/NF and the role of inner-sphere complexation between the active sites of MnO2 and peroxymonosulfate were thoroughly investigated. Compared with traditional nano/micro-sized catalysts, 3D macroscopic MnO2/NF with facile recovery and high stability potentially facilitates fascinating applications as green heterogeneous catalysis approach.

  • High catalytic performance of laccase wired to naphthylated multiwall carbon nanotubes
    • A. Ben Tahar
    • Kamila Sadowska
    • Jan Biernat
    • Ewa Paluszkiewicz
    • P. Cinquin
    • D. Martin
    • A. Zebda
    2020 Pełny tekst BIOSENSORS & BIOELECTRONICS

    The direct electrical connection of laccase on the electrode surface is a key feature in the design of efficient and stable biocathodes. However, laccases can perform a direct electron transfer only when they are in the preferable orientation toward the electrode. Here we report the investigation of the orientation of Laccase from Amano on multi-walled carbon nanotube surface modified with naphthalene group. Naphthylated multi wall carbon nanotubes were synthesized and the kinetics of Amano laccase adsorption and its direct electro catalytic activity toward oxygen reduction were investigated by QCM and electrochemical technics. Compared to pristine multi-walled carbon nanotube, laccase shows a high affinity to be adsorbed on naphthylated carbon nanotube. Moreover, laccase adsorption on naphthylated multi-walled carbon nanotubes surface is a very fast process and its electrical wiring to naphthylated multi-walled carbon nanotubes is accompanied by a reorientation and arrangement of adsorbed laccase. The naphthylated carbon nanotubes composite biocathode exhibits a high-performance biocathodes for oxygen reduction by direct electron transfer with maximum current densities of 3 mAcm-2.

  • Higher Responsiveness to Rosuvastatin in Polygenic versus Monogenic Hypercholesterolemia: A Propensity Score Analysis
    • Agnieszka Mickiewicz
    • Marta Futema
    • Agnieszka Ćwiklinska
    • Agnieszka Kuchta
    • Maciej Jankowski
    • Mariusz Kaszubowski
    • Magdalena Chmara
    • Bartosz Wasąg
    • Marcin Fijałkowski
    • Miłosz Jaguszewski
    • Steve E. Humphries
    • Marcin Gruchała
    2020 Pełny tekst Life

    Background: The monogenic defect in familial hypercholesterolemia (FH) is detected in ∼40% of cases. The majority of mutation-negative patients have a polygenic cause of high LDL-cholesterol (LDL-C). We sought to investigate whether the underlying monogenic or polygenic defect is associated with the response to rosuvastatin. Methods: FH Individuals were tested for mutations in LDLR and APOB genes. A previously established LDL-C-specific polygenic risk score (PRS) was used to examine the possibility of polygenic hypercholesterolemia in mutation-negative patients. All of the patients received rosuvastatin and they were followed for 8 ± 2 months. A propensity score analysis was performed to evaluate the variables associated with the response to treatment. Results: Monogenic subjects had higher mean (±SD) baseline LDL-C when compared to polygenic (7.6 ± 1.5 mmol/L vs. 6.2 ± 1.2 mmol/L; p < 0.001). Adjusted model showed a lower percentage of change in LDL-C after rosuvastatin treatment in monogenic patients vs. polygenic subjects (45.9% vs. 55.4%, p < 0.001). The probability of achieving LDL-C targets in monogenic FH was lower than in polygenic subjects (0.075 vs. 0.245, p = 0.004). Polygenic patients were more likely to achieve LDL-C goals, as compared to those monogenic (OR 3.28; 95% CI: 1.23-8.72). Conclusion: Our findings indicate an essentially higher responsiveness to rosuvastatin in FH patients with a polygenic cause, as compared to those carrying monogenic mutations.

  • Highly Conserved Homotrimer Cavity Formed by the SARS-CoV-2 Spike Glycoprotein: A Novel Binding Site
    • Umesh Kalathiya
    • Monikaben Padariya
    • Marcos Mayordomo
    • Małgorzata Lisowska
    • Judith Nicholson
    • Ashita Singh
    • Maciej Bagiński
    • Robin Fahraeus
    • Neil Carragher
    • Kathryn Ball
    • Juergen Haas
    • Alison Daniels
    • Ted R. Hupp
    • Javier Antonio Alfaro
    2020 Pełny tekst Journal of Clinical Medicine

    An important stage in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) life cycle is the binding of the spike (S) protein to the angiotensin converting enzyme-2 (ACE2) host cell receptor. Therefore, to explore conserved features in spike protein dynamics and to identify potentially novel regions for drugging, we measured spike protein variability derived from 791 viral genomes and studied its properties by molecular dynamics (MD) simulation. The findings indicated that S2 subunit (heptad-repeat 1 (HR1), central helix (CH), and connector domain (CD) domains) showed low variability, low fluctuations in MD, and displayed a trimer cavity. By contrast, the receptor binding domain (RBD) domain, which is typically targeted in drug discovery programs, exhibits more sequence variability and flexibility. Interpretations from MD simulations suggest that the monomer form of spike protein is in constant motion showing transitions between an “up” and “down” state. In addition, the trimer cavity may function as a “bouncing spring” that may facilitate the homotrimer spike protein interactions with the ACE2 receptor. The feasibility of the trimer cavity as a potential drug target was examined by structure based virtual screening. Several hits were identified that have already been validated or suggested to inhibit the SARS-CoV-2 virus in published cell models. In particular, the data suggest an action mechanism for molecules including Chitosan and macrolides such as the mTOR (mammalian target of Rapamycin) pathway inhibitor Rapamycin. These findings identify a novel small molecule binding-site formed by the spike protein oligomer, that might assist in future drug discovery programs aimed at targeting the coronavirus (CoV) family of viruses.

  • High-Temperature Oxidation of Heavy Boron-Doped Diamond Electrodes: Microstructural and Electrochemical Performance Modification
    • Jacek Ryl
    • Mateusz Cieślik
    • Artur Zieliński
    • Mateusz Ficek
    • Bartłomiej Dec
    • Kazimierz Darowicki
    • Robert Bogdanowicz
    2020 Pełny tekst Materials

    In this work, we reveal in detail the effects of high-temperature treatment in air at 600 °C on the microstructure as well as the physico-chemical and electrochemical properties of boron-doped diamond (BDD) electrodes. The thermal treatment of freshly grown BDD electrodes was applied, resulting in permanent structural modifications of surface depending on the exposure time. High temperature affects material corrosion, inducing crystal defects. The oxidized BDD surfaces were studied by means of cyclic voltammetry (CV) and scanning electrochemical microscopy (SECM), revealing a significant decrease in the electrode activity and local heterogeneity of areas owing to various standard rate constants. This effect was correlated with a resultant increase of surface resistance heterogeneity by scanning spreading resistance microscopy (SSRM). The X-ray photoelectron spectroscopy (XPS) confirmed the rate and heterogeneity of the oxidation process, revealing hydroxyl species to be dominant on the electrode surface. Morphological tests using scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealed that prolonged durations of high-temperature treatment lead not only to surface oxidation but also to irreversible structural defects in the form of etch pits. Our results show that even subsequent electrode rehydrogenation in plasma is not sufficient to reverse this surface oxidation in terms of electrochemical and physico-chemical properties, and the nature of high-temperature corrosion of BDD electrodes should be considered irreversible.

  • High-Temperature Structural and Electrical Properties of BaLnCo2O6 Positrodes
    • Iga Szpunar
    • Ragnar Strandbakke
    • Magnus H. Sorby
    • Sebastian Wachowski
    • Maria Balaguer
    • Mateusz Tarach
    • José M Serra
    • Agnieszka Witkowska
    • Ewa Dzik
    • Truls Norby
    • Maria Gazda
    • Aleksandra Mielewczyk-Gryń
    2020 Pełny tekst Materials

    The application of double perovskite cobaltites BaLnCo2O6−δ (Ln = lanthanide element) in electrochemical devices for energy conversion requires control of their properties at operating conditions. This work presents a study of a series of BaLnCo2O6−δ (Ln = La, Pr, Nd) with a focus on the evolution of structural and electrical properties with temperature. Symmetry, oxygen non-stoichiometry, and cobalt valence state have been examined by means of Synchrotron Radiation Powder X-ray Diffraction (SR-PXD), thermogravimetry (TG), and X-ray Absorption Spectroscopy (XAS). The results indicate that all three compositions maintain mainly orthorhombic structure from RT to 1000 °C. Chemical expansion from Co reduction and formation of oxygen vacancies is observed and characterized above 350 °C. Following XAS experiments, the high spin of Co was ascertained in the whole range of temperatures for BLC, BPC, and BNC.

  • Historia rozwoju trakcji elektrycznej i jej obecność na Politechnice Gdańskiej
    • Jacek Skibicki
    2020 Pełny tekst Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej

    W artykule przedstawiono zarys historii trakcji elektrycznej w świetle obecności i rozwoju tej dyscypliny na Politechnice Gdańskiej. Szczególnie skupiono się na rozwoju transportu zelektryfikowanego w rejonie Pomorza Gdańskiego z perspektywy prac wykonywanych przez pracowników Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej.

  • HISTORY OF INITIAL ENERGY AND WATER NETWORK DEVELOPMENT IN QATAR
    • Mohd Zaman
    • Marek Olesz
    2020 Pełny tekst Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej

    Qatar: A country which had to be associated with neighboring countries like UAE or Saudi Arabia for people to know about it, stands proud today due to the ample production and exporting of Black Gold. A country with almost no vegetation or suitable weather to harvest crops, turned from being heavily dependent on trading Pearls to exporting natural oil and gas to all over the globe. The paper outlines in details the history of the development of Energy sector in the State of Qatar. Being under British protection around the Arabian sea and Ottoman Empire from Land, there was not much of interest in this region. However, the scenario changed drastically after the discovery of Oil in 1938. Being able to produce and export the oil in huge quantity, it took Qatar less than 40 years to transform its energy sector totally. The paper describes these post oil discovery developments in the energy sector of the State of Qatar and links History to the Present.

  • Homoclinics for singular strong force Lagrangian systems
    • Marek Izydorek
    • Joanna Janczewska
    • Jean Mawhin
    2020 Pełny tekst Advances in Nonlinear Analysis

    We study the existence of homoclinic solutions for a class of generalized Lagrangian systems in the plane, with a C1-smooth potential with a single well of infinite depth at a point ξ and a unique strict global maximum 0 at the origin.Under a strong force condition around the singular point ξ, via minimization of an action integral, we will prove the existence of at least two geometrically distinct homoclinic solutions.

  • Homoleptic mono-, di-, and tetra-iron complexes featuring phosphido ligands: a synthetic, structural, and spectroscopic study
    • Kinga Kaniewska
    • Łukasz Ponikiewski
    • Natalia Szynkiewicz
    • Bartłomiej Cieślik
    • Jerzy Pikies
    • J. Krzystek
    • Alina Dragulescu-Andrasi
    • Sebastian Stoian
    • Rafał Grubba
    2020 Pełny tekst DALTON TRANSACTIONS

    We report the first series of homoleptic phosphido iron complexes synthesized by treating either the β-diketiminato complex [(Dippnacnac)FeCl2Li(dme)2] (Dippnacnac = HC[(CMe)N(C6H3-2,6-iPr2)]2) or [FeBr2(thf )2] with an excess of phosphides R2PLi (R = tBu, tBuPh, Cy, iPr). Reaction outcomes depend strongly on the bulkiness of the phosphido ligands. The use of tBu2PLi precursor led to an anionic diiron complex 1 encompassing a planar Fe2P2 core with two bridging and two terminal phosphido ligands. An analogous reaction employing less sterically demanding phosphides, tBuPhPLi and Cy2PLi yielded diiron anionic complexes 2 and 3, respectively, featuring a short Fe–Fe interaction supported by three bridging phosphido groups and one additional terminal R2P− ligand at each iron center. Further tuning of the P-substrates bulkiness gave a neutral phosphido complex 4 possessing a tetrahedral Fe4 cluster core held together by six bridging iPr2P moieties. Moreover, we also describe the first homoleptic phosphanylphosphido iron complex 5, which features an iron center with low coordination provided by three tBu2P-P(SiMe3)− ligands. The structures of compounds 1–5 were determined by single-crystal X-ray diffraction and 1–3 by 1H NMR spectroscopy. Moreover, the electronic structures of 1–3 were interrogated using zero-field Mössbauer spectroscopy and DFT methods.

  • Horyzontem II za koło polarne – arktyczna wyprawa polarna naukowców z Politechniki Gdańskiej
    • Klaudia Kosek
    • Małgorzata Szopińska
    • Joanna Potapowicz
    2020 Pełny tekst Pismo PG

    W dniach od 24 sierpnia do 17 września 2020 roku dr inż. Klaudia Kosek (WILiŚ), dr inż. Małgorzata Szopińska (WILiŚ) oraz mgr inż. Joanna Potapowicz (WCh) uczestniczyły w 43. Wyprawie Polarnej Instytutu Geofizyki PAN. Ekspedycja naukowa ujęta była w programie badawczym zawartym w projekcie grantowym Preludium (nr 2017/25/N/NZ9/01506), finansowanym przez Narodowe Centrum Nauki, pt. „Oznaczanie składników odżywczych, będących podstawowym czynnikiem umożliwiającym wzrost bakteriocenozy w zlewni rzeki arktycznej południowo-zachodniego Spitsbergenu”, którego kierownikiem jest dr inż. Klaudia Kosek.

  • How can Systems Thinking Help Us Handling the COVID-19 Crisis?
    • Krzysztof Zięba
    2020 Pełny tekst

    Purpose: COVID-19 pandemic outbreak remains one of the most influential events in the global economy over the recent years. While being primarily public health-related, it has a tremendous impact on many other aspects, such as public transport, education, and business management. Many businesses were forced to introduce rapid changes to their business models in order to survive. The aim of this paper is to show the complexity and inter-relations of changes triggered by COVID-19 outbreak. Understanding of this complexity is crucial for developing business resilience to similar events in the future. Methodology: The paper uses Systems Thinking approach to analyse influence of COVID-19 pandemic on business operations. Causal loop diagrams are used to show the complicated mechanisms behind the impact of pandemic on several aspects of business operation and management. Findings: Causal loop diagrams indicate that complicated relations between various elements may produce surprising and unexpected outcomes. The existing delays may result in actions bringing counterintuitive results. Perceptions of some variables play more important roles than actual variables and it often requires more than one actor to solve a particular problem – hence the need for organisational, as well as social learning. Adaptive business management may prove to be a particular challenge for small business owners. Research limitations: The paper is mostly of a conceptual nature. Causal loop diagrams require extensive data in order to be transformed into full Systems Thinking models. Hence this paper may serve as a basis for further development. Practical implications: The paper provides useful insights into the complex nature of contemporary business operation and management in the wake of a major epidemiological crisis. It may contribute to a better understanding of important factors that often tend to be disregarded and not paid enough attention to by business owners/managers. Originality/value: The paper links one of the major current challenges for the global economy with Systems Thinking, which offers a holistic perspective on business operation and management with emphasis on linkages and interactions between numerous stakeholders involved. It offers food for thought not only for academics, but also to business owners/managers, aware of the complexity of contemporary world

  • How does stakeholder pressure influence CSR-practices? A construction industry model based on a European sample
    • Rafał Kowalczyk
    2020 Pełny tekst

    The stakeholder pressure is one of the most vital powers which determines CSR implementation and can provide organizations with the motivation to adopt corporate social responsibility (CSR) strategy, as the stakeholder theory claims. The current investigation replications Kowalczyk’s (2019) study, who examined the same structure of relations based on the Polish sample. The essence of this replication is to find out whether CSR- practice is driven by ‘stakeholder pressure’ and ‘CSR-company culture’ vary when controlled by selected European countries or not. Namely, a 'European model of CSR-practice' is embedded in the European culture, or it does not exist (yet). Some earlier studies suggest that sociocultural context matters when it comes to CSR-practice. Therefore, this study aims to check how intensively European cultural context affects organizational cultural context and stakeholder pressure when influencing CSR-practices in the construction industry by employing a sample composed of selected European countries. Kowalczyk’s (2019) model was then replicated based on a convenience sample composed of 282 cases from five European countries. The structural equation modeling method (SEM) was applied to analyze data and verify hypotheses. The findings confirmed that stakeholder pressure is the most substantial influence of power on CSR-practices. Moreover, although the current study proves that CSR practice differs depending on its implementation, it does not present all aspects of the potential differences. Further, deeper research is required to understand it better.

  • How ethics combine with big data: a bibliometric analysis
    • Marta Kuc-Czarnecka
    • Magdalena Olczyk
    2020 Pełny tekst Humanities & Social Sciences Communications

    The term Big Data is becoming increasingly widespread throughout the world, and its use is no longer limited to the IT industry, quantitative scientific research, and entrepreneurship, but entered as well everyday media and conversations. The prevalence of Big Data is simply a result of its usefulness in searching, downloading, collecting and processing massive datasets. It is therefore not surprising that the number of scientific articles devoted to this issue is increasing. However, the vast majority of research papers deal with purely technical matters. Yet, large datasets coupled with complex analytical algorithms pose the risk of non-transparency, unfairness, e.g., racial or class bias, cherry-picking of data, or even intentional misleading of public opinion, including policymakers, for example by tampering with the electoral process in the context of ‘cyberwars’. Thus, this work implements a bibliometric analysis to investigate the development of ethical concerns in the field of Big Data. The investigation covers articles obtained from the Web of Science Core Collection Database (WoS) published between 1900 and July 2020. A sample size of 892 research papers was evaluated using HistCite and VOSviewer software. The results of this investigation shed light on the evolution of the junction of two concepts: ethics and Big Data. In particular, the study revealed the following array of findings: the topic is relatively poorly represented in the scientific literature with the relatively slow growth of interest. In addition, ethical issues in Big Data are discussed mainly in the field of health and technology.

  • How thermal stability of ionic liquids leads to more efficient TiO2-based nanophotocatalysts: Theoretical and experimental studies
    • Anna Rybińska-fryca
    • Alicja Mikoajczyk
    • Justyna Łuczak
    • Marta Paszkiewicz-Gawron
    • Monika Paszkiewicz
    • Adriana Zaleska-Medynska
    • Tomasz Puzyn
    2020 Pełny tekst JOURNAL OF COLLOID AND INTERFACE SCIENCE

    Ionic liquids (ILs) containing distinct nitrogen-bearing organic cations (pyridinium, pyrrolidinium, imidazolium, ammonium, morpholinium) were first used for the preparation of 23 IL-TiO2 types of composites by ionic liquid assisted solvothermal synthesis. These 23 optimal ILs structures (i.e. compounds exhibiting an optimal combination of specific properties, functionality, and safety) for synthesis and experimental validation were selected by computational high-throughput screening from a combinatorically created library containing 836 ILs theoretically designed and characterized candidates. Then, selected IL-TiO2 structures with potential photocatalytic activity were synthesized with the use of solvothermal reaction. Then, the decomposition level, the role of the individual IL cation structure on the morphology, thermal stability, surface and photocatalytic properties of the IL-TiO2 microparticles were determined experimentally. The chemoinformatic analysis of the relationship between the structure of the ionic liquid, its thermal stability under the conditions of synthesis and photocatalytic activity was applied for the first time. The results presented here are the first step in the development of methodology (combined experimental and theoretical) that may simplify the procedure of designing safer and more efficient TiO2-based photocatalyst. The developed computational methodology makes it possible to predict properties of newly synthesized IL-TiO2 materials before synthesis and identifies structural features of ILs that influence the efficiency of IL-TiO2 system. The presented approach reduces the number and cost of necessary experiments, as well as increases the success ratio of efficient TiO2-based photocatalyst design by a selection of optimal IL structures (i.e. ionic liquid characterized by a combination of most promising physicochemical features).

  • Human Feedback and Knowledge Discovery: Towards Cognitive Systems Optimization
    • Caterine Silva de Oliveira
    • Cesar Sanin
    • Edward Szczerbicki
    2020 Pełny tekst Procedia Computer Science

    Current computer vision systems, especially those using machine learning techniques are data-hungry and frequently only perform well when dealing with patterns they have seen before. As an alternative, cognitive systems have become a focus of attention for applications that involve complex visual scenes, and in which conditions may vary. In theory, cognitive applications uses current machine learning algorithms, such as deep learning, combined with cognitive abilities that can broadly generalize to many tasks. However, in practice, perceiving the environment and adapting to unforeseen changes remains elusive, especially for real time applications that has to deal with high-dimensional data processing with strictly low latency. The challenge is not only to extract meaningful information from this data, but to gain knowledge and also to discover insight to optimize the performance of the system. We envision to tackle these difficulties by bringing together the best of machine learning and human cognitive capabilities in a collaborative way. For that, we propose an approach based on a combination of Human-in-the-Loop and Knowledge Discovery in which feedback is used to discover knowledge by enabling users to interactively explore and identify useful information so the system can be continuously trained to gain previously unknown knowledge and also generate new insights to improve human decisions.

  • Hybrid Analysis of Structures Composed of Axially Symmetric Objects
    • Małgorzata Warecka
    • Rafał Lech
    • Piotr Kowalczyk
    2020 Pełny tekst IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES

    — A hybrid method for the scattering problems in shielded and open structures is presented. The procedure is based on the combination of body-of-revolution involving finite-element methods with impedance matrix formulation and the mode-matching technique, which can be utilized for the analysis of structures with axially symmetrical scatterers. In order to confirm the validity and efficiency of the proposed approach, a few examples of electromagnetic field scattering in open and waveguide structures are analyzed. The results cohere with those obtained by commercial software

  • Hybrid Expert System for Computer-Aided Design of Ship Thruster Subsystems
    • Andrzej Kopczyński
    2020 Pełny tekst IEEE Access

    The article presents an expert system supporting the design of ship's power subsystems, in particular the thruster subsystem. The proposed hybrid expert system uses the results of simulation tests as the additional source of knowledge. The results of system operation are collated in a report which can be used as part of ship design description. The work oriented on developing the expert system is the continuation of the research carried out in cooperation with the shipyard's design office, the main aim of which was to automate selected stages of the ship's design process. The hybrid expert system for computer-aided design of ship thruster subsystems can support designers by creating part of the technical description of the thruster subsystem, evaluation of static and dynamic properties, and by checking if design solutions have met the requirements of classification societies. Additionally, the expert system supports collecting and providing information about the elements and structures of the thruster subsystem. Finally, the system provides a document with the description of the thruster structure and elements used in it. The proposed expert system is dedicated to the initial design stages.

  • Hybrid Method Analysis of Unshielded Guiding Structures
    • Małgorzata Warecka
    • Rafał Lech
    • Piotr Kowalczyk
    2020 Pełny tekst

    A combination of mode matching, finite element methods and generalized impedance matrix is presented in a context of propagation problems for open guiding structures. The computational domain is divided into two regions: the first one is a circular cylinder containing whole guiding structure and the second one surrounds this artificial cylinder. The impedance matrix is calculated with the use of finite element method in the first region and fields outside are expressed by analytical functions. As a last step propagation coefficients are obtained with the use of global roots and poles finding algorithm. The results for simple dielectric ridge waveguides are presented and compared with alternative solutions.

  • Hybrid Modulation for Modular Voltage Source Inverters with Coupled Reactors
    • Krzysztof Szwarc
    • Paweł Szczepankowski
    • Janusz Nieznański
    • Cezary Swinarski
    • Aleksandr Usoltsev
    • Ryszard Strzelecki
    2020 Pełny tekst ENERGIES

    This paper proposes and discusses a concept of a hybrid modulation for the control of modular voltage source inverters with coupled reactors. The use of coupled reactors as the integrating elements leads to significant reduction in the size and weight of the circuit. The proposed modulation combines novel coarsely quantized pulse amplitude modulation (CQ-PAM) and innovative space-vector pulse width modulation (SVPWM). The former enjoys very low transistor switching frequency and low harmonic elimination, while the latter ensures high resolution of amplitude control. The SVPWM is based on the use of barycentric coordinates. The feasibility of the proposed solution is verified by simulations and laboratory tests of a 12-pulse modular voltage source inverters with two-level and three-level component inverters.

  • Hybrid Multi-Criteria Method of Analyzing the Location of Distributed Renewable Energy Sources
    • Alicja Stoltmann
    2020 Pełny tekst ENERGIES

    This paper presents the development and the application of a hybrid multi-criteria method, the combination of the Analytic Hierarchy Process (AHP), and numerical taxonomy (NT),to support the decision making on the location of distributed renewable energy sources meetingvarious types of assessment criteria. Finding criteria weights, using the AHP method, eliminates thedisadvantage of NT—which, in current form, is defined by its extreme values. The NT method is less mathematically complicated than the AHP method, and thus, less time-consuming. The combination of methods was used to investigate: (1) Which location among these analyzed has the best chance of implementation considering the author's set of criteria to describe the proposed locations in detail; and (2) which detailed criterion has the greatest impact on achieving the main goal. The proposed universal set of criteria consists of five main criteria (technical, economic, social, environmental, and legal), under which twenty-eight detailed criteria are listed. The hybrid multicriteria methodology was used to rank the proposed set of four wind farm locations in terms of chances for investment implementation in the shortest possible time. The ranking of the location obtained with this method should be treated as an element supporting the decision-maker. The location for wind power plant with installed capacity 40 MW was found to be the most suitable, and the results showed that the main contributing factors are carbon avoidance rate and the impact of the investment on environmentally protected areas.

  • Hybrid P3HT: PCBM/GaN nanowire/Si cascade heterojunction for photovoltaic application
    • Giorgi Tchutchulashvili
    • Krzysztof P. Korona
    • Wojciech Mech
    • Sergij Chusnutdinow
    • Marta Sobanska
    • Kamil Klosek
    • Zbigniew R. Zytkiewicz
    • Wojciech Sadowski
    2020 Pełny tekst JOURNAL OF NANOPARTICLE RESEARCH

    Poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) are commonly used for the fabrication of organic photovoltaics (OPV). Efficiency limitations of OPVs could be circumvented by incorporation of inorganic nanostructures into organic blends. Again, integration of organic solar cells with well-developed silicon photovoltaic technology is ultimately desirable. In present work, GaN nanowires with diameters of 25-50 nm and two lengths (200 and 500 nm) have been grown using molecular beam epitaxy technique. Solar-grade monocrystalline silicon wafers were used as substrates for nanowire synthesis. GaN nanostructures were incorporated into P3HT:PCBM photoactive layer in order to facilitate charge transfer between P3HT:PCBM and Si. Samples with and without nanowires were compared. Addition of nanowires led to improvement in photovoltaic performance. Open circuit voltage has risen by 72% and short circuit current density – by 200%. Rs have decreased 50 times and PCE rose 20.7 times. Additional maxima could be observed in photocurrent spectrum corresponding to carriers being generated near GaN absorption edge. Moreover, External Quantum Efficiency pikes near GaN absorption edge, indicating the formation of current transfer channel via P3HT/GaN/Si cascade heterojunction. Mechanism explaining source of abovementioned improvement is proposed.

  • Hybrid Technique for the EM Scattering Analysis with the Use of Ring Domain Decomposition
    • Michał Baranowski
    • Sebastian Dziedziewicz
    • Rafał Lech
    • Piotr Kowalczyk
    2020

    A hybrid technique combining finite-element and mode-matching methods for the analysis of scattering problems in open space is presented here. The main idea is based on impedance matrix descriptions of the boundary surrounding the discrete computational domain and combine it with external field described analytically. The discrete analysis, which is the most time- and memory-consuming, is limited here only to the close proximity of the posts or fragments of post which geometry is complex. All the obtained results have been verified by comparison with simulations performed using alternative methods or commercial software.

  • Hybrid TiO2–Polyaniline Photocatalysts and their Application in Building Gypsum Plasters
    • Agnieszka Sulowska
    • Izabela Wysocka
    • Daniel Pelczarski
    • Jakub Karczewski
    • Anna Zielińska-Jurek
    2020 Pełny tekst Materials

    Hybrid materials of conjugated polymer and titanium(IV) oxide have attracted considerable attention concerning their potential benefits, including (i) ecient exploitation of visible light, (ii) a high adsorption capacity for organic contaminants, (iii) and eective charge carriers separation. The new class of the photocatalysts is promising for the removal of environmental pollutants in both aqueous and gaseous phases. For the first time, in this study, the polyaniline (PANI)–TiO2 hybrid composite was used for the degradation of phenol in water and toluene in the gas phase. Polyaniline–TiO2 was prepared by the in situ polymerization of aniline on the TiO2 surface. The obtained hybrid material was characterized by diuse reflectance spectroscopy (DR/UV-Vis), X-ray diraction (XRD), fast-Fourier transformation spectroscopy (FTIR), photoluminescence (PL) spectroscopy, microscopy analysis (SEM/TEM), and thermogravimetric analysis (TGA). An insight into the mechanism was shown based on the photodegradation analysis of charge carrier scavengers. Polyaniline is an ecient TiO2 photosensitizer for photodegradation in visible light ( > 420 nm). The trapping experiments revealed that mainly h+ and OH were the reactive oxygen species that were responsible for phenol degradation. Furthermore, the PANI–TiO2 hybrid nanocomposite was used in gypsum plaster to study the self-cleaning properties of the obtained building material. The eect of PANI–TiO2 content on the hydrophilic/hydrophobic properties and crystallographic structure of gypsum was studied. The obtained PANI–TiO2-modified gypsum plaster had improved photocatalytic activity in the reaction of toluene degradation under Vis light

  • Hybridization of valuation procedures as a medicine supporting the real estate market and sustainable land use development during the covid-19 pandemic and afterwards
    • Małgorzata Renigier-Biłozor
    • Sabina Źróbek
    • Marek Walacik
    • Artur Janowski
    2020 LAND USE POLICY

    Currently we are facing the pandemic situation that occur all over the world. Regardless the country or even the region, the negative consequences that are expected could be very big and the level of crisis is not predictable. This situation is the challenge for the real estate market as well. Due to this fact, the authors believe that there is the time when deep transformation of approaches, procedures and awareness related to valuation domain becomes. Today, due to the fact of the global COVID-19 and pandemic restrictions is the best time to implement the automated models and advanced technological solutions to the valuation world. The authors proposed the hybrid approach that is the way to reconcile the participants on the property market. Hybrid approach is understanding as the synergy in combining aspects of new (automated solutions) and traditional components that are developed in the agile mode system creation. The proposed solutions can be treated as a cure for some symptoms of the real estate market infection but also as a vaccine, which should to a large extent prevent restrictions and nuisance in real estate valuation in case of repeated infection.

  • Hybrid‐mode single‐slope ADC with improved linearity and reduced conversion time for CMOS image sensors
    • Miron Kłosowski
    2020 Pełny tekst INTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS

    In the paper, a single‐slope analog‐to‐digital converter (ADC) for integrated CMOS image sensor applications with an improved technique of conversion has been proposed. The proposed hybrid‐mode ADC automatically uses one of the following conversion techniques: time based (i.e. PWM) or voltage based (i.e. single‐slope). During the ADC operation, the clock frequency and reference voltage are modified in order to reduce the conversion time and achieve the optimal linearity. Owing to this, the pixel using a photodiode working in the integration mode achieves a linear photoconversion characteristics (irradiance to digital number), and the conversion period, which is determined by the darkest parts of a scene, is reduced by an order of magnitude comparing with known ADC solutions. The proposed conversion technique has been validated with the ASIC prototype of a CMOS imager containing photosensors integrated with the ADCs. The ASIC was fabricated in standard 0.18 μm CMOS technology. A specialized measurement system has been used to optimize linearity in the hybrid‐mode conversion (integral nonlinearity below 2 LSB). The conversion period has been reduced 15 times compared with the standard technique. Measurements confirm functionality of the proposed approach, implemented within a small pixel area.

  • Hydration of Oxometallate Ions in Aqueous Solution
    • Maciej Śmiechowski
    • Ingmar Persson
    2020 Pełny tekst INORGANIC CHEMISTRY

    The strength of hydrogen bonding to and structure of hydrated oxometallate ions in aqueous solution have been studied by double difference infrared (DDIR) spectroscopy and large-angle X-ray scattering (LAXS), respectively. Anions are hydrated by accepting hydrogen bonds from the hydrating water molecules. The oxygen atom of the permanganate and perrhenate ions form weaker and longer hydrogen bonds to water than the hydrogen bonds in bulk water (i.e., they act as structure breakers), while the oxygen atoms of the chromate, dichromate, molybdate, tungstate, and hydrogenvanadate ions form hydrogen bonds stronger than those in bulk water (i.e., they act as structure makers). The oxometallate ions form one hydration shell distinguishable from bulk water as determined by DDIR spectroscopy and LAXS. The hydration of oxoanions results in X−O bond distances ca. 0.02 Å longer than those in unsolvated ions in the solid state not involved in strong bonding to counterions. The oxygens of oxoanions with a central atom from the second and third series in the periodic table and the hydrogenvanadate ion hydrogen bind three hydrating water molecules, while oxygens of oxoanions with a heavier central atom only form hydrogen bonds to two water molecules.

  • Hydrodynamic cavitation based advanced oxidation processes: Studies on specific effects of inorganic acids on the degradation effectiveness of organic pollutants
    • Michał Gągol
    • Elvana Cako
    • Kirill Fedorov
    • Reza Soltani
    • Andrzej Przyjazny
    • Grzegorz Boczkaj
    2020 Pełny tekst JOURNAL OF MOLECULAR LIQUIDS

    The use of cavitation in advanced oxidation processes (AOPs) to treat acidic effluents and process water has become a promising trend in the area of environmental protection. The pH value of effluents – often acidified using an inorganic acid, is one of the key parameters of optimization process. However, in the majority of cases the effect of kind of inorganic acid on the effectiveness of degradation is not studied. The present study describes the results of investigations on the use of hydrodynamic cavitation (HC) for the treatment of a model effluent containing 20 organic compounds, representing various groups of industrial pollutants. The effluent was acidified using three different mineral acids. It was demonstrated that the kind of acid used strongly affects the effectiveness of radical processes of oxidation of organic contaminants as well as formation of harmful secondary pollutants. One of important examples is a risk of formation of p-nitrotolune. Sulfuric acid was the only chemical used for acidification which caused effective treatment with lack of formation of monitored type of secondary pollutants. The best treatment effectiveness – during a 6-hour cavitation process - in most cases much above 80% along with 90% TOC removal was obtained in the case of sulfuric acid. Nitric acid provided lower effectiveness (above 60% for most of the compounds). The worst performance are reported for hydrochloric acid – below 50% of degradation for most of the compounds.

  • Hydrodynamic Model of the New Waterway through the Vistula Spit
    • Michał Szydłowski
    • Tomasz Kolerski
    2020 Pełny tekst Polish Maritime Research

    The decision to build a new waterway (strait) in the Polish part of the Vistula Spit was made in 2017. The new connection between the Gulf of Gdańsk and the Vistula Lagoon is planned as an artificial navigable channel with a lock and a small port. During storm surges and wind tides in the gulf or in the lagoon, sluicing will be re-quired for vessels to tackle the Vistula Spit. This procedure does not require significant water flow through the channel in normal conditions. However, in the case of a lock failure or in the case of controlled opening of the gate to increase water exchange in the lagoon or to reduce flood risk in the Vistula Lagoon, high flow rates may occur in the navigable channel and in the neighboring port basin. In order to investigate the hydraulic conditions in such extraordinary situations, numerical modeling of the hydrodynamics during water damming in the gulf or in the lagoon is performed. To analyse the hydrodynamics of the artificial connection between the sea and the lagoon during periods of high water stages, mathematical modeling is required. This paper presents the shallow water equations (SWE) model adapted to simulate the flow through the port basin and the navigable channel.

  • Hydrogen Embrittlement and Oxide Layer E ect in the Cathodically Charged Zircaloy-2
    • Grzegorz Gajowiec
    • Michał Bartmański
    • Beata Majkowska-Marzec
    • Andrzej Zieliński
    • Bartosz Chmiela
    • Marek Derezulko
    2020 Pełny tekst Materials

    The present paper is aimed at determining the less investigated effects of hydrogen uptake on the microstructure and the mechanical behavior of the oxidized Zircaloy-2 alloy. The specimens were oxidized and charged with hydrogen. The different oxidation temperatures and cathodic current densities were applied. The scanning electron microscopy, X-ray electron diffraction spectroscopy, hydrogen absorption assessment, tensile, and nanoindentation tests were performed. At low oxidation temperatures, an appearance of numerous hydrides and cracks, and a slight change of mechanical properties were noticed. At high-temperature oxidation, the oxide layer prevented the hydrogen deterioration of the alloy. For nonoxidized samples, charged at different current density, nanoindentation tests showed that both hardness and Young’s modulus revealed the minims at specific current value and the stepwise decrease in hardness during hydrogen desorption. The obtained results are explained by the barrier effect of the oxide layer against hydrogen uptake, softening due to the interaction of hydrogen and dislocations nucleated by indentation test, and hardening caused by the decomposition of hydrides. The last phenomena may appear together and result in hydrogen embrittlement in forms of simultaneous hydrogen-enhanced localized plasticity and delayed hydride cracking.

  • Hydrogen embrittlement of X2CrNiMoCuN25-6-3 super duplex stainless steel welded joints under cathodic protection
    • Aleksandra Świerczyńska
    • Dariusz Fydrych
    • Michał Landowski
    • Grzegorz Rogalski
    • Jerzy Łabanowski
    2020 CONSTRUCTION AND BUILDING MATERIALS

    The effect of cathodic polarization conditions on hydrogen degradation of X2CrNiMoCuN25-6-3 super duplex stainless steel welded joints, obtained using flux cored arc and submerged arc welding methods, was evaluated. Slow strain rate tensile tests of base material and welded specimens, ferrite content measurements, scanning electron microscopy observations, and statistical analysis were performed. It was found that hydrogenation of super duplex steel welded joints under the conditions of cathodic protection in artificial seawater environment leads to hydrogen embrittlement and that the weld area shows the highest degree of degradation. Welded joints made with higher heat input and under higher current density tend to cause an increase in the degradation of mechanical properties. A series of models to analyze the relationship between conditions and properties of material under extreme environmental conditions were successfully elaborated and evaluated.

  • Hydrophobic deep eutectic solvents in microextraction techniques–A review
    • Patrycja Makoś
    • Edyta Słupek
    • Jacek Gębicki
    2020 Pełny tekst MICROCHEMICAL JOURNAL

    Over the past decade, deep eutectic solvents (DES) have been widely studied and applied in sample preparation techniques. Until recently, most of the synthesized DES were hydrophilic, which prevented their use in the extraction of aqueous samples. However, after 2015 studies on the synthesis and application of hydrophobic deep eutectic solvents (HDES) has rapidly expanded. Due to unique properties of HDES i.e. density, viscosity, acidity or basicity, polarity and volatility, good extractabilities for various target analytes, which could be altered by careful selection of the hydrogen bond donor (HBD) and hydrogen bond acceptor (HBA) components, HDES are promising alternatives to the traditional organic solvents employed in sample preparation. Moreover, the possibility HDES synthesis of non-toxic ingredients, makes HDES meet all the standards of green analytical chemistry. Practical applications of HDES in sample preparation include conventional liquid-liquid extraction, and several types of liquid-phase microextraction, as well as solid phase extraction. The present review covers a comprehensive summarizing of available literature data on the most important physicochemical properties of HDES playing a key role in aqueous sample preparation methods, their limitations as well as challenges in this area, and a perspective of their future are described.