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Gdańsk University of Technology

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  • Trace elements content of surface peat deposits in the Solovetsky Islands (White Sea)
    • Krystyna Kozioł
    • Joanna Korzeniowska
    • Daniel Okupny
    • Elżbieta Bezak-mazur
    • Stanisław Żurek
    2020 Full text Mires and Peat

    Peatlands form environmental archives of trace element deposition. In this regard they are particularly valuable for areas such as the Arctic, where regular pollution monitoring is either impossible or extremely costly. The aim of this study was to assess pollution in the Solovetsky Islands (65° 05' N, 35° 53' E) by examining the spatial variability in trace element content of the uppermost layer of peat, immediately below the surface layer of green vegetation. We evaluated Cr, Cd, Ni and Pb contents in samples taken from ombrotrophic (raised bog) and mesotrophic (transitional) mires and in different microtopographical settings (hummock/hollow), and calculated the following pollution indices: geoaccumulation index (Igeo), contamination factor (Cf) and degree of contamination (Cdeg). The contents of these elements were markedly lower in the Solovetsky Islands than reported from other parts of central and northern Europe. Depending on the pollution index considered, the studied peat samples could be classified as unpolluted to considerably polluted. The local spatial patterns showed the highest values of Cd in samples collected near the sea, while the highest contents of Cr and Ni were noted at sampling points located farther inland. Moreover, Cr and Pb concentrations were higher in raised bogs than in transitional mires, and this contrast was accentuated if raised bog was represented by hummocks alone. These patterns are consistent with the likely sources of Cr, Ni and Pb being atmospheric pollution; and with higher mobility of Cd in seawater, which periodically floods the transitional mires. Amongst the trace elements determined, the most consistent values across peat types and sampling locations were found for Ni, which could be successfully used for pollution monitoring even in transitional mires.

  • Transformacja Dworca Morskiego w Gdyni na Muzeum Emigracji
    • Robert Hirsch
    2020 Full text Ochrona Dziedzictwa Kulturowego

    Artykuł omawia współczesne adaptacje budynków historycznych w Polsce, określając dwa główne nurty: komercyjny i niekomercyjny. Jako przykład niekomercyjnej transformacji przedstawiony został przypadek modernistycznego Dworca Morskiego w Gdyni z lat 30. XX w. przekształconego na Muzeum Emigracji. Przedsięwzięcie zakończone uroczystym otwarciem muzeum w 2015 r. zyskało wiele przychylnych opinii i zostało laureatem w konkursie "Zabytek zadbany", organizowanym przez Generalnego Konserwatora Zabytków. Pomimo pozytywnych efektów tej transformacji, w artykule podjęto próbę krytycznej oceny tej inwestycji pod względem konserwatorskim.

  • Transient modeling in common DC link of power converters
    • A. Anuchin
    • G.l. Demidova
    • Ryszard Strzelecki
    • M.s. Yakovenko
    2020 Full text Science, Technology and Arts Research Journal

    Предмет исследования. Представлена математическая модель силовых преобразователей электропривода, питающихся от общего звена постоянного тока, на примере тяговых электроприводов карьерного самосвала БЕЛАЗ-90 мощностью 280 кВт. Модель выполнена в пакете MATLAB/Simulink. Новизна предложенной модели заключается в применении новой топологии силовой схемы для исследования работы двух инверторов, под- ключенных к одному звену постоянного тока. Представлена возможность исследования переходных процессов в распределенном звене постоянного тока с целью уменьшения пульсаций тока, как в конденсаторной батарее инверторов, так и в общем звене постоянного тока. Метод. В целях снижения пульсаций на аппаратном уровне предложен метод введения дополнительной индуктивности между конденсаторами инверторов. С этой же целью при широтно-импульсной модуляции на алгоритмическом уровне предложено введение фазового сдвига опор- ных сигналов двух параллельно работающих инверторов. Разработана математическая модель, позволяющая оценивать пульсации тока между инвертором и конденсатором звена постоянного тока и между конденсатором и источником питания. Основные результаты. Показано, что алгоритмический метод вдвое снижает пульсации тока между инвертором и конденсатором звена постоянного тока и до 10 раз снижает ток между конденсатором инвертора и источником питания. Практическая значимость. Предложенная модель может быть использована при проверке токовой нагрузки элементов силового преобразователя в процессе проектирования систем мно- годвигательного электропривода (станочные приводы, гибридные транспортные средства).

  • Transient States during Short-circuit in a Line Powered by UPS and its Impact on Earth Fault Loop Impedance Measurement and Power Quality
    • Jacek Katarzyński
    • Marek Olesz
    2020

    The short-circuit in a line powered by Uninterruptible Power Supply (UPS) during different UPS operation modes is presented in the article. The transient state condition related to the short-circuit in a line fed from double conversion On-line UPS is discussed in detail. The results of the measurements of earth fault loop impedance (FLI) in circuits powered by UPS with the instruments of various manufacturers are presented. The dispersion of the measurement results, depending on UPS operation mode and on the instrument test current value is observed. The uncertainty of FLI measurement in UPS-powered circuits is pointed out, and its impact on the power quality and the evaluation of effectiveness of protection against electric shock is explained.

  • Transport of paracetamol in swellable and relaxing polyurethane nanocomposite hydrogels
    • Marta Motke
    • Justyna Strankowska
    • Jerzy Kwela
    • Marek Józefowicz
    • Michał Strankowski
    2020 Full text POLYMER BULLETIN

    Polyurethane hydrogels are potentially attractive materials for biomedical applications. They are able to absorb large amount of water, biological fluids or active substances, and thus, they have potential to be used as absorbents or wound-healing dressings. They are also used for the controlled release of therapeutics because of their capacity to embed biologically active agents in their water-swollen network. The presence of organofillized montmorillonite (Cloisite® 30B) in polyurethane nanocomposite hydrogels remarkably improves the swelling capability, but on the other hand slows down the release process of an active substance from the matrix. The swelling of paracetamol solution by the nanocomposite matrix and the release process of this active substance from the hydrogel were investigated using gravimetric analysis and spectroscopic method. The kinetics of both these processes were accurately analyzed by the use of Korsmeyer–Peppas and modified Hopfenberg and Weibull models. In the present paper, three different nanocomposite systems with various amounts of Cloisite® 30B were studied. The results of these studies confirm beneficial impact of the nanosize effect on the drug diffusion processes in polyurethane nanocomposite hydrogels.

  • Transverse surface waves on a cylindrical surface with coating
    • Victor Eremeev
    • Giuseppe Rosi
    • Salah Naili
    2020 Full text INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE

    We discuss the propagation of transverse surface waves that are so-called whispering-gallery waves along a surface of an elastic cylinder with coating. The coating is modelled in the framework of linearized Gurtin–Murdoch surface elasticity. Other interpretations of the surface shear modulus are given and relations to so-called stiff interface and stiff skin model are discussed. The dispersion relations are obtained and analyzed.

  • Trendy rozwojowe współczesnej telekomunikacji i wynikające z tego zagrożenia
    • Ryszard Katulski
    2020 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    Telekomunikacja to dziedzina wiedzy i techniki, której przeznaczeniem jest przenoszenie informacji, z założenia z dowolnego miejsca do innego dowolnego miejsca nie tylko na kuli ziemskiej, lecz także w dostępnej nam przestrzeni. Walorem szczególnym tego jest telekomunikacja radiowa, która umożliwia tworzenie połączeń telekomunikacyjnych w sposób bezprzewodowy, za pomocą zjawiska fali radiowej, które – jak wiadomo – ma naturę pola elektromagnetycznego. Pozwala to przekazywać informacje od nadawców do odbiorców znajdujących się w stanie ruchu, a więc potencjalnie obsługiwać każdego użytkownika wyposażonego w tzw. terminal końcowy. Przy czym jest to możliwe w każdym czasie i w dowolnym miejscu. Jak widać, znaczenie telekomunikacji we współczesnym świecie trudno jest przecenić.

  • Tribological Properties of Ni-P/Si3N4 Nanocomposite Layers Deposited by Chemical Reduction Method on Aluminum Alloy AW-7075
    • Kazimierz Czapczyk
    2020 Full text Materials

    The article presents the results of tribological tests of Ni-P/Si3N4 nanocomposite and Ni-P nickel layers deposited on the AW-7075 aluminum alloy by chemical reduction method, and the AW-7075 alloy without coating. Nanocomposite layers were produced using Si3N4 siliconnitride in the form of a polydisperse powder whose particle sizes ranged from 20 to 25 nm. The influence of the content of the dispersion phase layer material on the abrasive wear, which was determined as the “ball on disc” method, was analyzed. Surface topography was examined by the contact method using a profilometer. The purpose of introducing Si3N4 particles into the Ni-P layer was to increase the wear resistance of AW-7075 aluminum alloy parts with an embedded nanocomposite coating. Based on the obtained test results, it was found that the Ni-P/Si3N4 layers are more resistant to wear than the Ni-P layers and the AW-7075 alloy layers, and are a good barrier against abrasive wear at various loads and environmental conditions.

  • Trimethylamine N-oxide and the reverse cholesterol transport in cardiovascular disease: a cross-sectional study
    • Laura Bordoni
    • Joanna J. Samulak
    • Angelika K. Sawicka
    • Iwona Pelikant-Malecka
    • Adrianna Radulska
    • Lukasz Lewicki
    • Leszek Kalinowski
    • Rosita Gabbianelli
    • Robert Olek
    2020 Full text Scientific Reports

    The early atherosclerotic lesions develop by the accumulation of arterial foam cells derived mainly from cholesterol-loaded macrophages. Therefore, cholesterol and cholesteryl ester transfer protein (CETP) have been considered as causative in atherosclerosis. Moreover, recent studies indicate the role of trimethylamine N-oxide (TMAO) in development of cardiovascular disease (CVD). The current study aimed to investigate the association between TMAO and CETP polymorphisms (rs12720922 and rs247616), previously identified as a genetic determinant of circulating CETP, in a population of coronary artery disease (CAD) patients (n = 394) and control subjects (n = 153). We also considered age, sex, trimethylamine (TMA) levels and glomerular filtration rate (GFR) as other factors that can potentially play a role in this complex picture. We found no association of TMAO with genetically determined CETP in a population of CAD patients and control subjects. Moreover, we noticed no differences between CAD patients and control subjects in plasma TMAO levels. On the contrary, lower levels of TMA in CAD patients respect to controls were observed. Our results indicated a significant correlation between GFR and TMAO, but not TMA. The debate whether TMAO can be a harmful, diagnostic or protective marker in CVD needs to be continued.

  • Tripped at the Finishing Line: The Åland Islands Internet Voting Project
    • David Duenas Cid
    • Iuliia Krivonosova
    • Radu Serrano
    • Marlon Freire
    • Robert Krimmer
    2020 Full text

    The Åland Islands spent years preparing an internet voting system, to be implemented for the first time in October 2019 for Parliamentary Elections. Despite this, the project was canceled the evening before the expected release date. In this paper, we explore the causes of this failure using a two-pronged approach including Information System failure perspectives and the approach to e-voting Mirabilis, focusing on organizational elements which provoked the decision not to use the system.

  • Trouble in Paradise? Barriers to Open Innovation in Regional Clusters in the Era of the 4th Industrial Revolution
    • Marita Mcphillips
    2020 Full text Journal of Open Innovation: Technology, Market, and Complexity

    The purpose of this paper is to provide an insight into the barriers faced by clusters as open innovation intermediaries. Literature review and an empirical study were performed, involving a nation-wide survey, case studies, and in-depth interviews with cluster actors involved in open innovation activities. This article conceptually links open innovation and clusters in the context of the fourth industrial revolution, empirically identifies barriers hindering open innovation in clusters, and indicates factors that might affect the open innovation processes in networked ecosystems. The findings confirm that the perception of barriers hindering open innovation in clusters differs between clusters already implementing open innovation and those which are still not active in this area. The findings contribute to a comprehensive understanding of the potential roles of clusters as open innovation intermediaries in the context of transitioning economies. With clusters playing a role in open innovation intermediary, public support at cluster level could increase openness to cooperation not only for member companies, but all participants in the regional innovation ecosystem.

  • Trust-Based Model for the Assessment of the Uncertainty of Measurements in Hybrid IoT Networks
    • Piotr Cofta
    • Cezary Orłowski
    • Jacek Lebiedź
    2020 Full text SENSORS

    The aim of this paper is to introduce a NUT model (NUT: network-uncertainty-trust) that aids the decrease of the uncertainty of measurements in autonomous hybrid Internet of Things sensor networks. The problem of uncertainty in such networks is a consequence of various operating conditions and varied quality of measurement nodes, making statistical approach less successful. This paper presents a model for decreasing the uncertainty through the use of socially inspired metaphors of reputation, trust, and confidence that are the untapped latent information. The model described in the paper shows how the individual reputation of each node can be assessed on the basis of opinions provided by other nodes of the hybrid measurement network, and that this method allows to assess the extent of uncertainty the node introduces to the network. This, in turn, allows nodes of low uncertainty to have a greater impact on the reconstruction of values. The verification of the model, as well as examples of its applicability to air quality measurements are presented as well. Simulations demonstrate that the use of the model can decrease the uncertainty by up to 55% while using the EWMA (exponentially weighted moving average) algorithm, as compared to the reference one.

  • Tuning the extraction properties of ionogel-coated Solid-phase microextraction fibers based on the solvation properties of the ionic liquids
    • Kateryna Yavir
    • Karolina Konieczna
    • Łukasz Marcinkowski
    • Adam Kloskowski
    2020 SEPARATION AND PURIFICATION TECHNOLOGY

    A silica-based network was used to immobilize ionic liquid-based ionogels and applied as a fiber coating forsolid-phase microextraction (SPME). The ionogels were prepared by a sol–gel process, using two ionic liquids,triethylsulfonium bis(trifluoromethylsulfonyl)imide ([Set3][TFSI]) and 1-butyl-1-methylpiperidinium bis(tri-fluoromethylsulfonyl)imide ([C4C1Pip][TFSI]), as well as their equimolar mixture. Methyltrimethoxysilane wasused as the sol–gel precursor, and trifluoroacetic acid as a reaction catalyst.The fabricated ionogel fibers were evaluated as sorbent coating in headspace SPME combined with gaschromatography with barrier ionization discharge detection for volatile organic compounds (VOCs). The fibersshowed a high affinity to aromatic VOCs, yielding good sensitivity and precision. Then, the developed methodwas applied to the analysis of aqueous samples.During the study, the main extraction parameters, i.e., salt concentration, extraction time, and temperature,were optimized for maximum fiber sorption and to maximize the enrichment factors. The average limits ofdetection were found to be 0.15 μg L−1, 0.40 μg L−1, and 0.07 μg L−1, and the enrichment factors were in the25700–61000, 33200–84700, and 29100–96500 ranges for [Set3], [C4C1Pip] and [Set3/C4C1Pip], respectively.The single fiber and fiber-to-fiber reproducibilities were below 11.2% and 30.6%, respectively. The results of thiswork suggest the possibility of fabricating selected extractants based on the physicochemical properties of theionic liquids and target analytes.

  • Two kinds of oxygen vacancies in lithium titaniate doped with copper as detected by EPR
    • Marcin Łapiński
    • Lidia Piekara-Sady
    • Robert Kozioł
    • Wojciech Sadowski
    • Barbara Kościelska
    2020 SOLID STATE SCIENCES

    Lithium titanate (Li1+xTi2-xO4) doped with Cu2+ ions was synthesized by sol-gel processing method. The structure and morphology are characterized by X-ray Diffraction (XRD), X-ray Photoemission Spectroscopy (XPS), Scanning Electron Microscopy (SEM) and Electron Paramagnetic Resonance (EPR). Spin Hamiltonian parameters describing Zeeman and hyperfine interaction for 63Cu2+ ions were obtained from EPR spectra simulations. The spectra are characteristic for (Cu-VO)0 close-associate pairs consisting of copper replacing Ti4+ ion and an adjacent doubly ionized oxygen vacancy. These oxygen vacancies serve as charge compensators for the substituting copper ions. However, there are additional narrow EPR signals at g = 2.004 in all samples, including the sample of LiTi2O4 without dopant. These signals are ascribed to single-electron trapped oxygen vacancies VO●. Superconductivity was not confirmed down to 4.2 K by magnetic measurements in all samples studied.

  • Tworzenie wartości wspólnej w uniwersytecie
    • Elżbieta Karwowska
    2020

    Problemem badawczym jest brak definicji pojęcia i modelu teoretycznego tworzenia wartości wspólnej w uniwersytecie, który jest przeszkodą dla przeprowadzenia dyskursu naukowego zmierzającego do zbadania jej możliwości oraz zasadności. Lepsze zrozumienie możliwości i zasadności tworzenia wartości wspólnej w uniwersytecie stworzy zaś nową przestrzeń do opracowania narzędzi wspomagających rozwijanie społecznej odpowiedzialności uniwersytetu. Celem rozprawy jest zdefiniowanie pojęcia oraz zbadanie możliwości i zasadności tworzenia wartości wspólnej w uniwersytecie. Aby osiągnąć przyjęty cel rozprawy, w pierwszej kolejności rozpoznano, jak rozumiane było dotąd pojęcie CSV w kontekście społecznej odpowiedzialności uniwersytetu. Następnie zaproponowano model tworzenia wartości wspólnej w uniwersytecie (CSVU, Creating Shared Value by the University) oraz zdefiniowano to pojęcie w oparciu o zaproponowany model. Kolejnym krokiem było zbadanie możliwości oraz zasadności tworzenia wartości wspólnej w uniwersytecie z perspektywy uczelni oraz z perspektywy jej otoczenia: administracji publicznej oraz biznesu. Eksploracja możliwości i zasadności CSVU z perspektywy uczelni nastąpiła za pomocą analizy tematycznej danych jakościowych zebranych za pomocą wywiadów z reprezentantami uczelni. Możliwość i zasadność CSVU z perspektywy administracji publicznej zbadano na podstawie analizy dokumentów i aktów prawnych, regulujących społeczną odpowiedzialność uczelni i ich relacje z otoczeniem społecznym i gospodarczym. Możliwość i zasadność CSVU z perspektywy biznesu zbadano zaś na podstawie analizy raportów z badań wtórnych, dotyczących opinii przedsiębiorców na temat współpracy z uczelniami. Rezultatem przeprowadzonych analiz jakościowych jest zidentyfikowanie szeregu uwarunkowań, a także szans i zagrożeń, które wpływają na możliwość i zasadność tworzenia wartości wspólnej w uniwersytecie. Wyniki przeprowadzonych badań mają również walor utylitarny, dzięki rekomendacjom w formie listy, która stanowi praktyczne wytyczne dla uniwersytetów, zainteresowanych tworzeniem wartości wspólnej.

  • Two-step mechanism of J-domain action in driving Hsp70 function
    • Bartlomiej Tomiczek
    • Wojciech Delewski
    • Łukasz Nierzwicki
    • Milena Stolarska
    • Igor Grochowina
    • Brenda Schilke
    • Rafal Dutkiewicz
    • Marta A. Uzarska
    • Szymon Ciesielski
    • Jacek Czub
    • Elizabeth Craig
    • Jaroslaw Marszalek
    2020 Full text PLoS Computational Biology

    J-domain proteins (JDPs), obligatory Hsp70 cochaperones, play critical roles in protein homeostasis. They promote key allosteric transitions that stabilize Hsp70 interaction with substrate polypeptides upon hydrolysis of its bound ATP. Although a recent crystal structure revealed the physical mode of interaction between a J-domain and an Hsp70, the structural and dynamic consequences of J-domain action once bound and how Hsp70s discriminate among its multiple JDP partners remain enigmatic. We combined free energy simulations, biochemical assays and evolutionary analyses to address these issues. Our results indicate that the invariant aspartate of the J-domain perturbs a conserved intramolecular Hsp70 network of contacts that crosses domains. This perturbation leads to destabilization of the domain-domain interface—thereby promoting the allosteric transition that triggers ATP hydrolysis. While this mechanistic step is driven by conserved residues, evolutionarily variable residues are key to initial JDP/Hsp70 recognition—via electrostatic interactions between oppositely charged surfaces. We speculate that these variable residues allow an Hsp70 to discriminate amongst JDP partners, as many of them have coevolved. Together, our data points to a two-step mode of J-domain action, a recognition stage followed by a mechanistic stage.

  • Tynki - wykonywanie i pielęgnacja
    • Maciej Niedostatkiewicz
    • Tomasz Majewski
    2020 Full text Inżynier Budownictwa

    W artykule przedstawiono podstawowe wymagania jakie powinny być zachowane podczas realizacji oraz późniejszej eksploatacji tynków tak aby jak najdłużej zachowac je w stanie wysokiej sprawności technicznej

  • Udział Biblioteki Politechniki Gdańskiej w procesie umiędzynarodowiania uczelni
    • Urszula Szybowska
    2020 Full text Pismo PG

    Umiędzynarodowienie szkolnictwa wyższego definiowane jest zasadniczo jako podejmowanie studiów na zagranicznych uczelniach oraz udział w międzynarodowych projektach badawczych i szkoleniowych. Umiędzynarodowienie szkół wyższych jest jednym z elementarnych wskaźników, które określają dziś rozwój nauki i szkolnictwa wyższego. Biblioteka PG na różnych polach wspiera uczelnię w procesie internacjonalizacji. Strategia rozwoju usług Biblioteki PG funkcjonującej w międzynarodowym środowisku opiera się zasadniczo na trzech filarach: dostosowaniu swoich zbiorów i usług do potrzeb użytkowników zagranicznych, uczestniczeniu w programie Erasmus+ oraz dynamicznym rozwijaniu współpracy z organizacjami międzynarodowymi.

  • Udział w wystawie zbiorowej WETWARE: PROLIFERACJA I PRZECZUCIE
    • Patryk Różycki
    2020

    „WETWARE: PROLIFERACJA I PRZECZUCIE” Wystawa w Instytucie Cybernetyki Sztuki Dzieła sztuki w ich materialnym aspekcie możemy postrzegać jako nośniki informacji programujące i stymulujące przebieg procesów społecznych. Wystawa proponuje namysł nad dziełami sztuki i aktywnościami artystycznymi poprzez pryzmat terminu WETWARE – rozrostu struktur biologicznych i fizycznych umożliwiających przejawianie się procesów mentalnych. Psycholog Karl H. Pribram ukuł termin „wetware”1, dla podkreślenia specyfiki biologicznej w zakresie zdolności przenoszenia poprzez struktury biologiczne (neurony) różnego rodzaju informacji. Marek Rogulski artystki i artyści: Marcin Bożek, Marta Branicka, Flora Ćwirko + Jan Maurycy Adamski, Jowan Czerkas, Urszula Dulewicz, Dorota Grubba Thiede + Danuta Ćwirko Godycka, Tomasz Kopcewicz, Marta Koniarska, Maria Krupa, Monika Krygier + Stefan Krygier + Włodzimierz Pietrzyk, Przemysław Kryszk, Ryszard Ługowski, Krzysztof Malec, Anna Malinowska, Andrzej Egon Fietke Miastkowski, Piotr Tadeusz Mosur, Mateusz Pęk, Katarzyna Podpora, Marek Rogulski, Magdalena Rosman, Patryk Różycki, Wojtek Sosnowski, Urszula Śliz, Xenia Uranova, Marcelo Zammenhoff, Sofia Żezmer.

  • Układy dynamiczne w analizie zachowania się geosyntetyków w kolejowych konstrukcjach inżynierskich
    • Eligiusz Mieloszyk
    • Anita Milewska
    • Sławomir Grulkowski
    2020 Full text Przegląd Komunikacyjny

    W analizie współpracy geosyntetyków z elementami konstrukcji inżynierskiej możemy je traktować jako membrany sprężyste lub powłoki posadowione na różnych rodzajach podłoża. Modelowanie układu rzeczywistego oznacza jego idealizację pod kątem uwzględnienia tych cech ośrodka i jego elementów, które wydają się najistotniejsze z punktu widzenia analizowanego problemu. Zbudowany zostanie model fizyczny, a następnie matematyczny przedstawiony w postaci uogólnionego układu dynamicznego. W tym opisie wykorzystuje się różne operatory. Prowadzą one do układów ciągłych o parametrach rozłożonych. Rozpoczynając od opisu z wykorzystaniem układów dynamicznych ciągłych można przejść do układów dynamicznych dyskretnych. Pozwala na to teoria uogólnionych układów dynamicznych, poprzez wykorzystanie innych operatorów. Takie podejście umożliwia prowadzenie analizy problemu z wykorzystaniem sygnałów ciągłych i dyskretnych. Otrzymane wyniki pozwalają też wyznaczać odpowiedzi analizowanych układów metodami analitycznymi, numerycznymi lub hybrydowymi.

  • Ultrafast degradation of brilliant cresyl blue under hydrodynamic cavitation based advanced oxidation processes (AOPs)
    • Elvana Cako
    • Kumaravel Dinesh Gunasekaran
    • Reza Darvishi Cheshmeh Soltani
    • Grzegorz Boczkaj
    2020 Full text Water Resources and Industry

    The study highlights effectiveness of hydrodynamic cavitation (HC) in the degradation of effluents polluted by Brilliant Cresyl Blue (BCB) dye. Optimal process parameters were cavitation number 0.27, inlet pressure 1.70 bar, temperature 20 °C and pH 7. The efficiency of HC was investigated in combination with other advanced oxidation processes, including the addition of external oxidants (hydrogen peroxide, ozone, and sodium persulfate) and photooxidation. A detailed investigation of reactive radical species present in the system is also presented. Hybrid processes based on HC revealed the highest synergism. Finally, ultrafast degradation of target oxazine dye (decolorization efficiency of 100%) within the short treatment time of 1 min was developed. The most effective process was a combination of hydrodynamic cavitation and ozonation with a synergistic coefficient of 1.84 and electrical energy per order EEO of 0.03 kWh m⁻³ order⁻¹. The presented solution is ready to be implemented as technology for industrial practice.

  • Ultrasound assisted solvent extraction of porous membrane-packed samples followed by liquid chromatography-tandem mass spectrometry for determination of BADGE, BFDGE and their derivatives in packed vegetables
    • Natalia Szczepańska
    • Paweł Kubica
    • Justyna Płotka-Wasylka
    • Błażej Kudłak
    • Jacek Namieśnik
    2020 Full text SCIENCE OF THE TOTAL ENVIRONMENT

    The problem of the presence of trace organic pollutants in food is of growing importance due to increasing awareness about their impact on newborns, infants and adults of reproductive age. Despite the fact that packaged food products offer many advantages, packaging can be a source of contamination for stored food. Thus, monitoring such pollution in food is of high importance. In this work, a novel methodology based on the solvent extraction of porous membrane-packed samples followed by liquid chromatography-tandem mass spectrometry was applied for the determination of bisphenol A diglycidyl ether (BADGE), bisphenol F diglycidyl ether (BFDGE) and their derivatives in packed vegetables. Several parameters of the extraction process were optimized, including the volume and type of extraction solvent as well as the sonication time. Due to advantages such as simplicity of use, short analysis time, and a reduction in the required amount solvent, the developed procedure can be considered green. In addition, the developed methodology was characterized by good validation parameters. Limit if quantitation (LOQ) was found to be in the range of 0.8 to 1.5 ng/g. The obtained recoveries varied from 78.3% to 111.2%. The repeatability of the extraction ranged between 0.6% and 5.8% (RSD). The proposed method was successfully applied to determine the presence of BADGE, BFDGE and their derivative compounds in the vegetable samples stored in different types of containers. The obtained data indicate that the majority of investigated samples were contaminated by chlorinated and hydroxyl derivatives of BADGE.

  • Ultrasound assisted synthesis of 3-alkynyl substituted 2-chloroquinoxaline derivatives: Their in silico assessment as potential ligands for N-protein of SARS-CoV-2
    • Shaik Shahinshavali
    • Kazi Hossain
    • Abbaraju Venkata Durga Nagendra Kumar
    • Alugubelli Gopi Reddy
    • Deepti Kolli
    • Ali Nakhi
    • Mandava Venkata Basaveswara Rao
    • Manojit Pal
    2020 TETRAHEDRON LETTERS

    In view of recent global pandemic the 3-alkynyl substituted 2-chloroquinoxaline framework has been explored as a potential template for the design of molecules targeting COVID-19. Initial in silico studies of representative compounds to assess their binding affinities via docking into the N-terminal RNA-binding domain (NTD) of N-protein of SARS-CoV-2 prompted further study of these molecules. Thus building of a small library of molecules based on the said template became essential for this purpose. Accordingly, a convenient and environmentally safer method has been developed for the rapid synthesis of 3-alkynyl substituted 2-chloroquinoxaline derivatives under Cu-catalysis assisted by ultrasound. This simple and straightforward method involved the coupling of 2,3-dichloroquinoxaline with commercially available terminal alkynes in the presence of CuI, PPh3 and K2CO3 in PEG-400. Further in silico studies revealed some remarkable observations and established a virtual SAR (Structure Activity Relationship) within the series. Three compounds appeared as potential agents for further studies.

  • Ultrasound-assisted heterogeneous activation of persulfate and peroxymonosulfate by asphaltenes for the degradation of BTEX in water
    • Kirill Fedorov
    • Maksymilian Plata-Gryl
    • Javed Khan
    • Grzegorz Boczkaj
    2020 Full text JOURNAL OF HAZARDOUS MATERIALS

    This study investigated – for the first time - the simultaneous degradation of benzene, toluene, ethylbenzene and o-xylene (BTEX) by persulfate (PS) and peroxymonosulfate (PMS) activated by asphaltenes (Asph) under ultrasound (US) irradiation. Advantageous properties such as high thermal stability, low production cost and extensive availability make asphaltenes as an appealing carbonaceous material for heterogeneous catalysis. The application of asphaltenes in PS/US increased the degradation of BTEXs from 31%, 34%, 35%, 32% to 78%, 94%, 98% and 98%, while the removal of these compounds in PMS/US system was improved from 26%, 27%, 24%, 20% to 76%, 91%, 97%, 97%, respectively. PS and PMS activation followed a typical sulfate-radical based advanced oxidation processes. In terms of activation of PS and PMS, the particles of asphaltenes intensified formation of reactive radicals by creating additional centers of cavitational events. Moreover, owing to π–π stacking interaction between asphaltenes and sp2-hybridized systems of BTEX, the contaminants undergo adsorption on the surface of asphaltenes and subsequent oxidation by formed radicals. The radical route of BTEX degradation in both PS/US/Asph and PMS/US/Asph systems was mainly contributed by sulfate (SO4•−) and hydroxyl radicals (HO•) and coexisting superoxide radical anions (O2•−) played a minor role.

  • Ultrastructural analysis of the submandibular sialoliths: Raman spectroscopy and electron back-scatter studies
    • Dmitry Tretiakov
    • Andrzej Skorek
    • Jacek Ryl
    • Joanna Wysocka
    • Kazimierz Darowicki
    • Dmitry Tretiakow
    2020 Full text ULTRASTRUCTURAL PATHOLOGY

    The aim of work was the epidemiological analysis of the occurrence of sialolithiasis of the submandibular gland in adults and the evaluation of the ultrastructure of salivary stones. The study sample consisted of 44 sialoliths. Analysis of the structure and chemical composition of sialoliths was performed using a Scanning Electron Microscope and Raman Spectroscopy. Comparing our results with the literature we can say that the epidemiology of sialolithiasis has not changed significantly over the past 50 years. A wide variety of sialoliths structure was observed. In 75% (33) cases a layered structure of salivary stones was observed, while in 25% (11) – homogeneous structure. The various distribution of organic and inorganic components was observed among all the analyzed sialoliths. Raman spectroscopy allows for preliminary analysis of the sialoliths structure with only a qualitative assessment of their composition, which significantly reduces the research value of this method. The presence of organic and inorganic compounds in the core and inner layers of the salivary glands stones confirms 2 basic theories of the formation of sialoliths: inflammation and deposition of the inorganic component as a result of disruption of saliva flow in the salivary glands.

  • Uncertainty of mass flow measurement using centric and eccentric orifice for Reynolds number in the range 10,000 ≤ Re ≤ 20,000
    • Anna Golijanek-Jędrzejczyk
    • Andrzej Mrowiec
    • Robert Hanus
    • Marcin Zych
    • Dariusz Świsulski
    2020 Full text MEASUREMENT

    The article analyses the impact of the Reynolds number on the estimated uncertainty of the mass flow rate measurement using an orifice plate. The objects of the research were two types of orifices: centric (ISA) and eccentric, with the diameter ratio β = 0.5. Studies were performed by Monte Carlo simulation and experiments for Reynolds numbers in the range 10,000 ≤ Re ≤ 20,000. The obtained results have shown that for both orifice types, the results obtained from the experiments and from the Monte Carlo simulation are similar. The nature of changes in the expanded uncertainty of the flow measurement is very similar for each type. For the both types of orifices, the value of the expanded uncertainty of the flow measurement increases linearly with the increasing Reynolds number.

  • Underfrequency Load Shedding: An Innovative Algorithm Based on Fuzzy Logic
    • Robert Małkowski
    • Janusz Nieznański
    2020 Full text ENERGIES

    In contemporary power systems, the load shedding schemes are typically based on disconnecting a pre-specified amount of load after the frequency drops below a predetermined value. The actual conditions at the time of disturbance may largely dier from the assumptions, which can lead to non-optimal or ineective operation of the load shedding scheme. For many years, increasing the eectiveness of the underfrequency load shedding (UFLS) schemes has been the subject of research around the world. Unfortunately, the proposed solutions often require costly technical resources and/or large amounts of real-time data monitoring. This paper puts forth an UFLS scheme characterized by increased eectiveness in the case of large disturbances and reduced disconnected power in the case of small and medium disturbances compared to the conventional load-shedding solutions. These advantages are achieved by replacing time-consuming consecutive load dropping with the simultaneous load dropping mechanism and by replacing ineective fixed-frequency activation thresholds independent of the state of the system with implicit adaptive thresholds based on fuzzy logic computations. The proposed algorithm does not require complex and costly technical solutions. The performance of the proposed scheme was validated using multivariate computer simulations. Selected test results are included in this paper.

  • Understanding the formation of metastable furan dication in collisions with ions
    • Ewa Erdmann
    • Suvasthika Indrajith
    • Jacopo Chiarinelli
    • Sergio Díaz-Tendero
    • Nestor F. Aguirre
    • Manuel Alcamí
    • Alicja Domaracka
    • Patrick Rousseau
    • Bernd Alan Huber
    • Paola Bolognesi
    • Lorenzo Avaldi
    • Marta Łabuda
    2020 Full text Journal of Physics : Conference Series

    This work relies on complementary theoretical and experimental studies of the processes induced by ion-furan collisions. Results of the Molecular Dynamics simulations and exploration of the energy profiles combined with coincidence mass spectrometry provide complete picture of the fragmentation of furan dication.

  • Underwater in situ local heat treatment by additional stitches for improving the weldability of steel
    • Jacek Tomków
    • Anna Janeczek
    2020 Full text Applied Sciences-Basel

    In this paper the influence of in situ local heat treatment performed by additional stitches on the weldability of high-strength low-alloy (HSLA) S355J2C+N steel was tested. The investigated steel is characterized by high susceptibility to cold cracking. It is necessary to find a method to improve the quality of welded joints. The local heat treatment was applied as an eect of bead-on plate welding made on the face of a Tekken test joint. The specimens were made by the use of covered electrodes in the water environment. For testing weldability, Tekken test specimens were made. Then, the dierent number of the pad welds with dierent overlapping were laid on the face of the tested welds. Non-destructive (NDT) visual and penetrant tests were undertaken. During the NDT, imperfections like shape mistakes and spatters were found. Then, metallographic macro- and microscopic testing were performed. The macroscopic observations proved that water environment can generate imperfections like cracking and pores. However, for specimens with additional stitches the number of imperfections decreased. Microscopic tests proved that the proposed technique aected the structure of the heat-aected zone (HAZ). The specimens without the application of additional stitches are characterized by brittle bainitic and martensitic structure. Specimens, in which the additional stitches were applied, contain tempered martensite, fine ferrite and fine pearlite in their HAZ. It was also observed that the number of cracks decreased for in situ local heat-treatment specimens. The final step was Vickers HV10 hardness measurement. These measurements confirmed previous results. The heat from additional stitches aected the steel by significantly decreasing the hardness by 80–100 HV10. The results of experiments showed that the heat from pad welds provided microstructural changes in heat-aected zones and a decrease in the susceptibility to cold cracking, which results in improvement in the weldability of HSLA steel in wet welding conditions.

  • Underwater Local Cavity Welding of S460N Steel
    • Jacek Tomków
    • Anna Janeczek
    • Grzegorz Rogalski
    • Adrian Wolski
    2020 Full text Materials

    In this paper, a comparison of the mechanical properties of high-strength low-alloy S460Nsteel welded joints is presented. The welded joints were made by the gas metal arc welding (GMAW)process in the air environment and water, by the local cavity welding method. Welded joints were testedfollowing the EN ISO 15614-1:2017 standard. After welding, the non-destructive—visual, penetrant,radiographic, and ultrasonic (phased array) tests were performed. In the next step, the destructive tests,as static tensile-, bending-, impact- metallographic (macroscopic and microscopic) tests, and VickersHV10 measurements were made. The influence of weld porosity on the mechanical properties of thetested joints was also assessed. The performed tests showed that the tensile strength of the jointsmanufactured in water (567 MPa) could be similar to the air welded joint (570 MPa). The standarddeviations from the measurements were—47 MPa in water and 33 MPa in the air. However, it was alsostated that in the case of a complex state of stress, for example, bending, torsional and tensile stresses,the welding imperfections (e.g., pores) significantly decrease the properties of the welded joint.In areas characterized by porosity the tensile strength decreased to 503 MPa. Significant differenceswere observed for bending tests. During the bending of the underwater welded joint, a smallerbending angle broke the specimen than was the case during the air welded joint bending. Also,the toughness and hardness of joints obtained in both environments were different. The minimumtoughness for specimens welded in water was 49 J (in the area characterized by high porosity) and inthe air it was 125 J (with a standard deviation of 23 J). The hardness in the heat-affected zone (HAZ)for the underwater joint in the non-tempered area was above 400 HV10 (with a standard deviation of37 HV10) and for the air joint below 300 HV10 (with a standard deviation of 17 HV10). The performedinvestigations showed the behavior of S460N steel, which is characterized by a high value of carbonequivalent (CeIIW) 0.464%, during local cavity welding.

  • Underwater Navigation Ssystem Based on Doppler Shift – Measurements and Error Estimations
    • Zawisza Ostrowski
    • Roman Salamon
    • Iwona Kochańska
    • Jacek Marszal
    2020 Full text Polish Maritime Research

    A new acoustic navigation system was developed to determine the position and speed of moving underwater objects such as divers and underwater vehicles. The path of an object and its speed were determined by the Doppler shifts of acoustic signals emitted by a transmitter placed on the object and received by four hydrophones installed at the periphery of the monitored body of water. The position and speed measurements were affected by errors mainly caused by acoustic reflections (returns) from the water body boundaries and surface reverberations. This paper discusses the source of the disturbances with the results of a simulation test and experimental measurements. It was demonstrated that the magnitude of the errors could be acceptable in most of the potential applications of the acoustic navigation system.

  • Unidirectional DC/DC Converter with Voltage Inverter for Fast Charging of Electric Vehicle Batteries
    • Jerzy, Ryszard Szymanski
    • Marta Żurek-mortka
    • Daniel Wojciechowski
    • Nikolai Poliakov
    2020 Full text ENERGIES

    The paper proposes the adaptation of the industrial plant’s power network to supply electric vehicle (EV) fast-charging converters (above 300 kW) using renewable energy sources (RESs). A 600 V DC microgrid was used to supply energy from RESs for the needs of variable speed motor drives and charging of EV batteries. It has been shown that it is possible to support the supply of drive voltage frequency converters (VFCs) and charging of EV batteries converters with renewable energy from a 600 V DC microgrid, which improves the power quality indicators in the power system. The possibility of implementing the fast EV batteries charging station to the industrial plant’s power system in such a way that the system energy demand is not increased has also been shown. The EV battery charging station using the drive converter has been presented, as well as the results of simulation and laboratory tests of the proposed solution.

  • Unieuro
    • Luciano Segreto
    2020

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  • Unifying Aspects of Generalized Calculus
    • Marek Czachor
    2020 Full text ENTROPY

    Non-Newtonian calculus naturally unifies various ideas that have occurred over the years in the field of generalized thermostatistics, or in the borderland between classical and quantum information theory. The formalism, being very general, is as simple as the calculus we know from undergraduate courses of mathematics. Its theoretical potential is huge, and yet it remains unknown or unappreciated.

  • Unlocking creativity with new technologies
    • Norbert Piotrowski
    2020 World Aerosols. The Voice of the Aerosol Industry

    Artificial intelligence, augmented and virtual reality, Internet of Things and digital twins are just a few concepts related to the fourth industrial revolution that is happening right before our eyes. The key question asked by managers in the aerosol sector recently is: what does all this new technology mean to me?

  • Untargeted Lipidomics Analysis of the Cyanobacterium Synechocystis sp. PCC 6803: Lipid Composition Variation in Response to Alternative Cultivation Setups and to Gene Deletion
    • Weronika Hewelt-Belka
    • Agata Kot-Wasik
    • Paula Tamagnini
    • Paulo Oliveira
    2020 Full text INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    Cyanobacteria play an important role in several ecological environments, and they are widely accepted to be the ancestors of chloroplasts in modern plants and green algae. Cyanobacteria have become attractive models for metabolic engineering, with the goal of exploring them as microbial cell factories. However, the study of cyanobacterial lipids’ composition and variation, and the assessment of the lipids’ functional and structural roles have been largely overlooked. Here, we aimed at expanding the cyanobacterial lipidomic analytical pipeline by using an untargeted lipidomics approach. Thus, the lipid composition variation of the model cyanobacterium Synechocystis sp. PCC 6803 was investigated in response to both alternative cultivation setups and gene deletion. This approach allowed for detecting differences in total lipid content, alterations in fatty-acid unsaturation level, and adjustments of specific lipid species among the identified lipid classes. The employed method also revealed that the cultivation setup tested in this work induced a deeper alteration of the cyanobacterial cell lipidome than the deletion of a gene that results in a dramatic increase in the release of lipid-rich outer membrane vesicles. This study further highlights how growth conditions must be carefully selected when cyanobacteria are to be engineered and/or scaled-up for lipid or fatty acids production.

  • Upper Limb Bionic Orthoses: General Overview and Forecasting Changes
    • Gustaw Rzyman
    • Jacek Szkopek
    • Grzegorz Redlarski
    • Aleksander Pałkowski
    2020 Full text Applied Sciences-Basel

    Using robotics in modern medicine is slowly becoming a common practice. However, there are still important life science fields which are currently devoid of such advanced technology. A noteworthy example of a life sciences field which would benefit from process automation and advanced robotic technology is rehabilitation of the upper limb with the use of an orthosis. Here, we present the state-of-the-art and prospects for development of mechanical design, actuator technology, control systems, sensor systems, and machine learning methods in rehabilitation engineering. Moreover, current technical solutions, as well as forecasts on improvement, for exoskeletons are presented and reviewed. The overview presented might be the cornerstone for future research on advanced rehabilitation engineering technology, such as an upper limb bionic orthosis.

  • Uproszczone metody obliczania cylindrycznych silosów z blachy falistej i słupów cienkościennych
    • Karol Rejowski
    • Piotr Iwicki
    • Andrzej Tejchman-Konarzewski
    2020 Full text Inżynieria i Budownictwo

    Celem artykułu jest wyznaczenie nośności wyboczeniowej trzech silosów wykonanych z falistej blachy ze sfałdowaniem w kierunku obwodowym, wzmocnionych słupami pionowymi stosując modele MES całych konstrukcji i ich segmentów oraz porównanie obliczonej nośności wyboczeniowej z Eurokodem 3, poprawkami do Eurokodu 3 i metodą zaproponowaną w literaturze. Nowym elementem analizowanym w pracy jest porównanie różnych metod analitycznych z wynikami analiz MES oraz procedurami normowymi. W artykule zweryfikowano także metodę opisaną w literaturze dla silosów, w których słupy miały zmienny przekrój poprzeczny, dopasowany do wypadkowych obciążeń w słupach.

  • Urban regeneration in urban functional areas in Poland as an instrument of implementation of the EU Cohesion Policy
    • Dorota Kamrowska-Załuska
    • Hanna Obracht-Prondzyńska
    2020 GROWTH AND CHANGE

    This study examines the role of urban regeneration policies in planning and governance within urban functional areas (UFAs) in Poland, in the context of the EU Cohesion Policy (CP). The empirical part of this study is based on comparing the approaches adopted in two Polish regions: Pomerania and Silesia. We describe the first successes but also the bottlenecks of the process, from negotiations and programming up to the implementation of the first tranche of integrated projects. We consider the factors that strengthen planning and governance within UFAs, while simultaneously influencing the local development, and territorial impacts of the EU Cohesion Policy in the given regions. This study is based on interviews with national, regional, and local actors. It defines the role of urban regeneration policies in shaping local socio‐economic and spatial development in these regions and identifies the conditions required for the implementation of urban regeneration in functional areas. We also draw lessons for the future CP programming period from the experience of Polish regions, among the main beneficiaries of the EU Cohesion Policy. By evaluating the influence of Cohesion Policy at different government levels, our study may influence the discourse on its future, particularly in the context of strengthening the cooperation and multilevel governance.

  • Urban Vegetation in Air Quality Management: A Review and Policy Framework
    • Joanna Badach
    • Małgorzata Dymnicka
    • Andrzej Baranowski
    2020 Full text Sustainability

    Recent episodes of high air pollution concentration levels in many Polish cities indicate the urgent need for policy change and for the integration of various aspects of urban development into a common platform for local air quality management. In this article, the focus was placed on the prospects of improving urban air quality through proper design and protection of vegetation systems within local spatial planning strategies. Recent studies regarding the mitigation of air pollution by urban greenery due to deposition and aerodynamic effects were reviewed, with special attention given to the design guidelines resulting from these studies and their applicability in the process of urban planning. The conclusions drawn from the review were used to conduct three case studies: in Gdańsk, Warsaw, and Poznan, Poland. The existing local urban planning regulations for the management of urban greenery were critically evaluated in relation to the findings of the review. The results indicate that the current knowledge regarding the improvement of urban air quality by vegetation is not applied in the process of urban planning to a sufficient degree. Some recommendations for alternative provisions were discussed.

  • Urchin-like TiO2 structures decorated with lanthanide-doped Bi2S3 quantum dots to boost hydrogen photogeneration performance
    • Magdalena Miodynska
    • Alicja Mikolajczyk
    • Beata Bajorowicz
    • Julia Zwara
    • Tomasz Klimczuk
    • Wojciech Lisowski
    • Grzegorz Trykowski
    • Henry P. Pinto
    • Adriana Zaleska-Medynska
    2020 Full text APPLIED CATALYSIS B-ENVIRONMENTAL

    The formation of heterojunctions between wide- and narrow-bandgap photocatalysts is commonly employed to boost the efficiency of photocatalytic hydrogen generation. Herein, the photoactivity of urchin-like rutile particles is increased by decorating with pristine as well as Er- or Yb-doped Bi2S3 quantum dots (QDs) at varied QD loadings (1–20 wt%) and doping degrees (1–15 mol%), and the best hydrogen evolution performance is achieved at Er and Yb contents of 10 mol%. Specifically, a hydrogen productivity of 1576.7 μmol gcat −1 is achieved after 20-h irradiation for TiO2 decorated by 10 mol% Yb-doped Bi2S3 QDs. Theoretical calculations show that the introduction of defects into the Bi2S3 lattice through Er/Yb doping promotes the creation of new energy levels and facilitates the transport of photogenerated charges during photocatalysis.

  • Usability of mobile applications: a systematic literature study
    • Paweł Weichbroth
    2020 Full text IEEE Access

    Since the release of the first mobile devices, the usability of on-board applications has been the concern not only of software vendors but hardware manufacturers as well. The academia community later willingly joined the discussion on usability in terms of theory and empirical measurement, having experience and knowledge in desktop settings. At first sight, such a background should guarantee a solid foundation to conduct research on software usability in a new setting. However, a preliminary study on the subject matter revealed methodological disorder in contemporary literature. As a matter of fact, a need emerged to review existing usability definitions, attributes and measures to recognize all associated aspects. In order to fill this void, we conducted a systematic literature review on usability studies indexed by the Scopus database and devoted to mobile applications. The input volume covers 790 documents from 2001 to 2018. The data analysis shows that the ISO 9241–11 usability definition has been adopted in an unchanged form and popularized as the standard by the HCI community. Secondly, in total, 75 attributes were identified and analysed. The most frequent are efficiency (70%), satisfaction (66%) and effectiveness (58%), which directly originate from the above definition. Subsequently, the less frequent are learnability (45%), memorability (23%), cognitive load (19%) and errors (17%). The last two concern simplicity (13%) and ease of use (9%). Thirdly, in the evaluation of usability, controlled observation and surveys are two major research methods applied, while eye-tracking, thinking aloud and interview are hardly used and serve as complementary to collect additional data. Moreover, usability evaluations are often confused with user experience dimensions, covering not only application quality characteristics, but also user beliefs, emotions and preferences. All these results indicate the need for further research on the usability of mobile applications, aiming to establish a consensus in the theory and practice among all interested parties.

  • Use of pyridinium and pyrrolidinium ionic liquids for removal of toluene from gas streams
    • Iwona Cichowska-Kopczyńska
    • Robert Aranowski
    2020 Full text JOURNAL OF MOLECULAR LIQUIDS

    Separation of toluene from a toluene/N2 gas mixture using supported liquid membranes based on a series of pyridinium (1-butylpyridinium- bis(trifluoromethylsulfonyl)imide - [C4Py][Tf2N], 1-hexylpyridinium trifluoromethanesulfone [C6Py][Tf2N]) and pyrrolidinium (1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide - [C4Pyrr][Tf2N], 1-hexyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide - [C6Pyrr][Tf2N], 1-butyl-1-methylpyrrolidinium trifluoromethanesulfone - [C4Pyrr][TfO]) ionic liquids (ILs) was studied over a wide range of temperatures. The toluene permeability and selectivity of separation was investigated in terms of cation and anion type. It was found that both pyridinium and pyrrolidinium ILs show high toluene permeability, up to 2034 barrers, with satisfying separation selectivity. An analysis of two key factors that have an influence on this process, that is diffusion in a form of resistance resulting from the viscosity of membrane liquid and the solubility expressed by the partition coefficient, was made.

  • Using Fast Frequency Hopping Technique to Improve Reliability of Underwater Communication System
    • Jan Schmidt
    2020 Full text Applied Sciences-Basel

    Acoustic underwater communication systems designed to work reliably in shallow coastal waters must overcome major limitations such as multipath propagation and the Doppler effect. These restrictions are the reason for the complexity of receivers being built, whose task is to decode a symbol on the basis of the received signal. Additional complications are caused by the low propagation speed of the acoustic wave in the water and the relatively narrow bandwidth. Despite the continuous development of communication systems using coherent modulations, they are still not as reliable as is desirable for reliable data transmission applications. This article presents an acoustic underwater communication system that uses one of the varieties of the spread spectrum technique i.e., the fast frequency hopping technique (FFH). This technique takes advantage of binary frequency-shift keying (BFSK) with an incoherent detection method to ensure the implementation of a system whose main priority is reliable data transmission and secondary priority is the transmission rate. The compromised choice of parameters consisted of the selection between the narrow band of the hydroacoustic transducer and the maximum number of carrier frequency hops, which results from the need to take into account the effects of the Doppler effect. In turn, the number of hops and the symbol duration were selected adequately for the occurrence of multipath propagations of an acoustic wave. In addition, this article describes experimental communication tests carried out using a laboratory model of the FFH-BFSK data transmission system in the shallow water environment of Lake Wdzydze/Poland. The test results obtained for three channels of different lengths are discussed.

  • Using Moodle as a Solution to Interdisciplinary E-collaboration Issues
    • Ewa Kozłowska
    2020 Full text International Journal of Research in E-learning

    Rapid technological development in recent years has contributed to numerous changes in many areas of life, including education and communication. Establishing interdisciplinary collaboration brings many benefits, however, it is often associated with numerous problems and inconveniences, as well as the need of constant improvement, lifelong learning, professional development (CPD) and finding an effective way of information transferring. Living in a constant rush makes logical order of information transferring become a key aspect, as more and more operations are being done chaotically using multiple online tools. Although collaboration happens to be complicated even for colleagues specializing in different aspects of the same profession, establishing cooperation between specific groups of interdisciplinary specialists, such as engineers and physicians, has a significant impact on modern diagnostics and medical treatment development. Based on some selected case studies investigated at Gdańsk University of Technology and Medical University of Gdańsk, supported by an overview of the available education and collaboration tools, a solution based on the Moodle LMS platform has been proposed, implemented, and analyzed.

  • Using UAV Photogrammetry to Analyse Changes in the Coastal Zone Based on the Sopot Tombolo (Salient) Measurement Project
    • Pawel Burdziakowski
    • Cezary Specht
    • Pawel S. Dabrowski
    • Mariusz Specht
    • Oktawia Lewicka
    • Artur Makar
    2020 Full text SENSORS

    The main factors influencing the shape of the beach, shoreline and seabed include undulation, wind and coastal currents. These phenomena cause continuous and multidimensional changes in the shape of the seabed and the Earth’s surface, and when they occur in an area of intense human activity, they should be constantly monitored. In 2018 and 2019, several measurement campaigns took place in the littoral zone in Sopot, related to the intensive uplift of the seabed and beach caused by the tombolo phenomenon. In this research, a unique combination of bathymetric data obtained from an unmanned surface vessel, photogrammetric data obtained from unmanned aerial vehicles and ground laser scanning were used, along with geodetic data from precision measurements with receivers of global satellite navigation systems. This paper comprehensively presents photogrammetric measurements made from unmanned aerial vehicles during these campaigns. It describes in detail the problems in reconstruction within the water areas, analyses the accuracy of various photogrammetric measurement techniques, proposes a statistical method of data filtration and presents the changes that occurred within the studies area. The work ends with an interpretation of the causes of changes in the land part of the littoral zone and a summary of the obtained results.

  • Utility analysis and rating of energy storages in trolleybus power supply system
    • Mikołaj Bartłomiejczyk
    • Leszek Jarzębowicz
    2020 Full text

    The article discusses two energy storage applications in power supply system of public electrified transport. The first application aims at reducing the peak power of the traction substation. The second application increases effectiveness of using solar power plant to cover partial power demand of traction supply system. These two applications were discussed and analyzed based on trolleybus supply system in Gdynia, where most measurements were recorded.

  • Utilization of Gaseous Carbon Dioxide and Industrial Ca-rich Waste for Calcium Carbonate Precipitation: A Review
    • Natalia Czaplicka
    • Donata Konopacka-Łyskawa
    2020 Full text ENERGIES

    Technologies for the management of various types of waste and the production of useful products from them are currently widely studied. Both carbon dioxide and calcium-rich waste from various production processes are problematic wastes that can be used to produce calcium carbonate. Therefore, the purpose of this paper is to provide an overview about the state of the development of processes that use these two wastes to obtain a valuable CaCO3 powder. The paper reviews the current research on the use of post-distillation liquid from the Solvay process, steelmaking slag, concrete, cement, and gypsum waste as well as some others industrial Ca-rich waste streams in the calcium carbonate precipitation process via carbonation route. This work is an attempt to collect the available information on the possibility of influencing the characteristics of the obtained calcium carbonate. It also indicates the possible limitations and implementation problems of the proposed technologies.

  • Utilizing Genome-Wide mRNA Profiling to Identify the Cytotoxic Chemotherapeutic Mechanism of Triazoloacridone C-1305 as Direct Microtubule Stabilization
    • Jarosław Króliczewski,
    • Sylwia Bartoszewska
    • Magdalena Dudkowska
    • Dorota Janiszewska
    • Agnieszka Biernatowska
    • David Crossman
    • Karol Krzymiński
    • Małgorzata Wysocka
    • Anna Romanowska
    • Maciej Bagiński
    • Michal Markuszewski
    • Renata J. Ochocka
    • James F. Collawn
    • Aleksander F. Sikorski
    • Ewa Sikora
    • Rafal Bartoszewski
    2020 Full text Cancers

    Rational drug design and in vitro pharmacology profiling constitute the gold standard in drug development pipelines. Problems arise, however, because this process is often dicult due to limited information regarding the complete identification of a molecule’s biological activities. The increasing aordability of genome-wide next-generation technologies now provides an excellent opportunity to understand a compound’s diverse eects on gene regulation. Here, we used an unbiased approach in lung and colon cancer cell lines to identify the early transcriptomic signatures of C-1305 cytotoxicity that highlight the novel pathways responsible for its biological activity. Our results demonstrate that C-1305 promotes direct microtubule stabilization as a part of its mechanism of action that leads to apoptosis. Furthermore, we show that C-1305 promotes G2 cell cycle arrest by modulating gene expression. The results indicate that C-1305 is the first microtubule stabilizing agent that also is a topoisomerase II inhibitor. This study provides a novel approach and methodology for delineating the antitumor mechanisms of other putative anticancer drug candidates.

  • UV Light-Modulated Fluctuation-Enhanced Gas Sensing by Layers of Graphene Flakes/TiO2 Nanoparticles
    • Janusz Smulko
    • Tomasz Chludziński
    • Umut Çindemir
    • Claes-Goran Granqvist
    • He Wen
    2020 Full text Journal of Sensors

    We present experimental results of fluctuation-enhanced gas sensing by low-cost resistive sensors made of a mixture of graphene flakes and TiO2 nanoparticles. Both components are photocatalytic and activated by UV light. Two UV LEDs of different wavelengths (362 and 394 nm) were applied to modulate the gas sensing of the layers. Resistance noise was recorded at low frequencies, between 8 Hz and 10 kHz. The sensors’ response was observed in an ambient atmosphere of synthetic air and toxic NO2 at selected concentrations (5, 10, and 15 ppm). We observed that flicker noise changed its frequency dependence at different UV light wavelengths, thereby providing additional information about the ambient atmosphere. The power spectral density changed by a few times as a result of UV light irradiation. The sensors were operated at 60 and 120°C, and the effect of UV light on gas sensing was most apparent at low operating temperature. We conclude that UV light activates the gas-sensing layer and improves gas detection at low concentrations of NO2. This result is desirable for the detection of the components of gas mixtures, and the modulated sensor can replace an array of independent resistive sensors which would consume much more energy for heating. We also suggest that a more advanced technology for preparing the gas-sensing layer, by use of spin coating, will produce corresponding layers with thickness of about a few μm, which is about ten times less than that for the tested samples. The effects induced by the applied UV light, having a penetration depth of only a few μm, would then be amplified.