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Repozytorium publikacji
Politechniki Gdańskiej

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  • An LC-MS/MS Method for a Comprehensive Determination of Metabolites of BTEX Anaerobic Degradation in Bacterial Cultures and Groundwater
    • Simon Godin
    • Paweł Kubica
    • Anthony Ranchou-Peyruse
    • Isabelle Le Hecho
    • Delphine Patriarche
    • Guilhem Caumette
    • Joanna Szpunar
    • Ryszard Lobinski
    2020 Pełny tekst Water

    BTEX (benzene, toluene, ethylbenzene, and the different xylene isomers), known for carcinogenic and neurotoxic effects, are common environmental contaminants. The first step for the development of the bioremediation technologies is the detection of intense microbial degradation in contaminated waters in the quest for the most active bacterial strains. This requires the multispecies analysis for BTEX metabolites which are considered as markers of microbial degradation. A direct (50 µL injection) HPLC–electrospray MS/MS analytical method was developed for the simultaneous analysis of 11 BTEX metabolites (o-, m-, p-toluic, salicylic, benzoate, benzyl, and phenyl succinic acids, 2-(1-phenylethyl)-, 2-(2-methylbenzyl), and 2-(3-methylbenzyl)-, 2-(4-methyl benzyl)-succinic acids) in bacterial cultures and ground waters down to 0.1 ng/mL. The optimization of the chromatographic conditions allowed for the resolution of position isomers of toluic and methylbenzyl-succinic acids. The stability of the analytes during sample storage tested in different conditions showed the instability of some of them when stored at room temperature. The feasibility of the method was demonstrated by the detection of all the investigated metabolites in a water sample of a deep aquifer hosting natural gas storage. A model laboratory study emphasized the importance of 2-(2-methylbenzyl)-succinic acid as a marker of anaerobic microbial degradation.

  • Analiza bibliometryczna w badaniach dotyczących prognozowania upadłości przedsiębiorstw w Polsce
    • Błażej Prusak
    2020

    Celem opracowania jest ukazanie obrazu piśmiennictwa poświęconego zagadnieniom prognozowania upadłości przedsiębiorstw w Polsce. Jako metodę badawczą zastosowano analizę bibliometryczną. Do analizy wykorzystano bazę Google Scholar oraz narzędzie Publish or Perish 7. Okresem badań objęto lata 1995– 2019. Jako frazy do wyszukiwania publikacji zastosowano: „prognozowanie upadłości”, „prognozowanie zagrożenia finansowego”, „systemy wczesnego ostrzegania”. Z analizy wynika, że tylko kilka publikacji uzyskało liczbę cytowań powyżej 100, a kilkanaście powyżej 50. Wiele opracowań charakteryzuje się niskim poziomem cytowalności. Liczba cytowanych publikacji z tego obszaru badawczego rosła od początku okresu analizy do lat 2012–2014 w zależności od przyjętej frazy a następnie malała. Jako ostateczny wynik badań ukazano ranking najbardziej cytowanych publikacji dotyczących prognozowania upadłości przedsiębiorstw w Polsce, co może być pomocne przy opracowywaniu analizy literatury podczas przygotowywania publikacji dotyczących prognozowania upadłości przedsiębiorstw.

  • Analiza danych pomiarowych na potrzeby obrazowania optyczną tomografią koherentną
    • Jerzy Pluciński
    2020

    W rozdziale omówiono wybrane aspekty związane z analizą danych pomiarowych na potrzeby obrazowania metodą optycznej tomografii koherentnej. Przedstawiono podstawowe zależności umożliwiające obrazowanie tkanek na podstawie analizy promieniowania wstecznie rozproszonego, mierzonego przez systemy OCT pracujące w dziedzinie czasu (TD-OCT) lub w dziedzinie częstotliwości (FD-OCT). Pokazano, że wykorzystując zaawansowane przetwarzanie sygnałów w funkcjonalnych systemach OCT, możliwe jest również obrazowanie również innych właściwości tkanek niż te, które wynikają bezpośrednio z właściwości rozpraszających. W szczególności omówiono dopplerowskie systemy OCT (D-OCT), systemy OCT czułe na stan polaryzacji (PS-OCT), spektroskopowe systemy OCT (S-OCT) oraz systemy pozwalające na optyczną elastografię koherentną (systemy OCE).

  • Analiza doboru parametrów pogłębiarki ssącej nasiębiernej
    • Damian Bocheński
    2020 Pełny tekst Journal of Polish CIMEEAC

    Artykuł przedstawia analizę doboru parametrów pogłębiarek ssących nasiębiernych. Do najważniejszych parametrów charakteryzujących pogłębiarki ssące nasiębierne należą pojemność ładowni gruntowej, prędkość pływania pogłębiarki oraz parametry instalacji pogłębiarskiej. Zaproponowano w analizie doboru tych parametrów zmienność kilku zmiennych ściśle związanych z doborem pogłębiarki, jest to czas załadunku i rozładunku oraz czas trwania przemieszczania się pogłębiarki pomiędzy miejscami załadunku i rozładunku. Przedstawiono wyniki obliczeń i sposób ich wykorzystania w procesie doboru parametrów pogłębiarki ssącej nasiębiernej.

  • Analiza dwóch zatorów lodowych wraz z przedstawieniem sposobów ochrony przed ich skutkami
    • Małgorzata Bratnikow
    2020

    W Polsce podczas zimy tworzą się różnego rodzaju zjawiska lodowe. Zalicza się do nich między innymi zatory lodowe. Mogą one stwarzać zagrożenie dla ludzi, czego przykładem mogą być zatory lodowe, które mogą wywołać powodzie zatorowe. Jednakże istnieją sposoby ograniczania negatywnych skutków tych zjawisk. W pracy omówiono formy lodowe przyczyniające się do tworzenia zatorów lodowych. Przedstawiono również dwa zatory lodowe, jeden w Pucku z roku 2010 oraz drugi z Elbląga z 2012 roku. Po omówieniu warunków wystąpienia tych zatorów lodowych przedstawione zostały wybrane sposoby zapobiegania ich skutkom.

  • Analiza funkcjonalnych właściwości innowacyjnych klejów modyfikowanych związkami cynku.
    • Robert Tylingo
    • Szymon Mania
    • Adrianna Banach
    2020

    Przedmiotem projektu było określenie aktywności wybranych związków cynku oraz klejów z ich dodatkiem w funkcji stężenia. Określono także wpływ modyfikacji klejów związkami cynku na właściwości reologiczne oraz wytrzymałość tworzonych połączeń papierowych.

  • Analiza ilościowa technologiczności konstrukcji oprzyrządowania obróbkowego - studium przypadku
    • Adam Barylski
    2020

    Omówiono ilościową metodę oceny technologiczności konstrukcji oprzyrządowania obróbkowego. Przedstawiono przykład oceny technologiczności zaprojektowanych trzech wersji uchwytów wiertarskich w procesie technologicznym części klasy dźwignia

  • ANALIZA MAGAZYNOWANIA ENERGII W UKŁADZIE CAES SPRZĘŻONYM Z GRUNTOWYM MAGAZYNEM CIEPŁA
    • Rafał Hyrzyński
    • Paweł Ziółkowski
    • Sylwia Gotzman
    • Bartosz Kraszewski
    • Janusz Badur
    2020 Energetyka, problemy energetyki i gospodarki paliwowo - energetycznej

    Elastyczne i dyspozycyjne elektrownie przyczynią się do trwającego procesu transformacji Polskich Sieci Elektroenergetycznych SA (PSE), ponieważ kompensują wahania energii elektrycznej wytwarzanej z odnawialnych źródeł energii, takich jak wiatr i fotowoltaika. W tym kontekście zasobniki CAES (Compressed Air Energy Storage) są obecnie jedyną alternatywą dla magazynów z wykorzystaniem elektrowni szczytowo-pompowych ze względu na możliwości uzyskania stosownej pojemności energetycznej magazynu. Wadą niniejszych instalacji jest strata ciepła wywołana wychłodzeniem powietrza po sprężeniu. W niniejszej pracy w pierwszej kolejności przeanalizowano sytuację współpracy obecnych elektrowni konwencjonalnych z farmami wiatrowymi, a następnie w oparciu o modele termodynamiczne przedstawiono wyniki procesu magazynowania energii w układzie CAES sprzężonym z rekuperacją za turbiną gazową. Zaproponowano również rozwiązanie z gruntowym wymiennikiem ciepła, ponieważ grunt ze względu na swoje własności może pełnić rolę magazynu energii cieplnej.

  • Analiza modeli opisujących wrzenie w przepływie w kanałach konwencjonalnych
    • Blanka Jakubowska
    2020 Chłodnictwo : organ Naczelnej Organizacji Technicznej

    W artykule przedstawiona została analiza wybranych korelacji pozwalających na wyznaczenie współczynników przejmowania ciepła podczas wrzenia w przepływie, które przeznaczone są dla kanałów o średnicach konwencjonalnych. Przedstawiona w pracy analiza została wykonana na podstawie badań eksperymentalnych dostępnych w literaturze, które prowadzone były dla pełnego zakresu zmiany stopnia suchości oraz stosunkowo szerokiego zakresu zmiany prędkości masowej. Zebrana baza danych eksperymentalnych zawiera dziesięć czynników chłodniczych, takich jak: NH3, CO2, R290, R600a, R1234yf, R134a, R245fa, R236fa, R152a oraz HFE7000. Zebraną i usystematyzowaną bazę danych eksperymentalnych porównano z dostępnymi w literaturze korelacjami opisującymi wrzenie w przepływie. W przedstawionych w pracy obliczeniach wykorzystanych zostało dziewięć modeli, tj. ogólną zależność Fanga i innych, Chena, Bertscha i innych, Shaha, Gungora i Wintertona, zmodyfikowaną korelację Gungora i Wintertona, Kima i Mudawara, Wojtana i innych oraz Lillo i innych.

  • Analiza numeryczna i analityczna przekrycia w kształcie powłoki synklastycznej o podstawie kwadratowej
    • Andrzej Ambroziak
    • Krzysztof Piątkowski
    2020 Pełny tekst Przegląd Budowlany

    W pracy poruszono problem obliczania przekrycia żelbetowego w kształcie powłoki synklastycznej ściętej o podstawie kwadratowej. Przedstawiono obliczenia analityczne i numeryczne sił w powłoce. Powłoka jest poddana działaniu głównie sił ściskających, co jest korzystne dla tego typu konstrukcji. W strefie brzegowej i podporowej konieczne jest wymiarowanie na mimośrodowe ściskanie i rozciąganie z uwagi na znaczący wzrost momentów zginających

  • Analiza numeryczna i wymiarowanie stropu kablobetonowego
    • Andrzej Ambroziak
    • Anna Błochowiak
    2020 Pełny tekst Przegląd Budowlany

    W pracy poruszono tematykę analizy numerycznej i wymiarowania stropu kablobetonowego. Przedstawiono przykład obliczeniowy, w którym omówiono poszczególne etapy budowy modelu numerycznego w programie SOFiSTiK oraz wymiarowania stropu żelbetowego kablobetonowego budynku biurowo-usługowego zaprojektowanego w układzie płytowo-słupowym.

  • Analiza porównawcza metod obliczeniowych stopnia turbinowego
    • Bożena Sobczak
    • Tomasz Groth
    2020

    Rozwój technologii komputerowych i ciągły wzrost dostępności do odpowiednich zasobów mocy obliczeniowej spowodował popularyzację obliczeń numerycznych. Aktualnie korzysta się na szeroką skalę z numerycznej mechaniki płynów, czyli tak zwanych obliczeń CFD. Właściwie przygotowane modele obliczeniowe pozwalają uzyskać bardzo dokładne wyniki na podstawie przeprowadzonych symulacji trójwymiarowych. Odpowiednio skorelowana symulacja może umożliwić przeprowadzenie analizy i znalezienie zależności w przepływie dla różnych geometrii obiektu. Ponadto wykorzystując różne algorytmy, można przeprowadzić optymalizację kształtu bez prowadzenia kosztownych badań na rzeczywistym przedmiocie. W ubiegłym stuleciu podczas procesu projektowania jakiegokolwiek obiektu technicznego posługiwano się głównie tzw. wzorami empirycznymi czyli takimi, które zostały opracowane na podstawie badań. Zawierały one jednak pewne uproszczenia mające na celu skrócenie i uproszczenie wykonywanych obliczeń. Do dzisiaj z powodzeniem można stosować te wzory, szczególnie dla uproszczonych przypadków, uzyskując przy tym bardzo dobre wyniki. Takim przypadkiem może być np. przepływ czynnika roboczego w pracującej turbinie.Celem niniejszego artykułu jest przedstawienie wyników przeprowadzonej analizy. Porównano efekty obliczeń parametrów termodynamicznych czynnika pracującego w turbinie nadkrytycznej, przeprowadzonych w arkuszu kalkulacyjnym, jak również symulacji trójwymiarowych w programie Ansys CFX. Sama zasada działania tego programu nie została opisana, natomiast skupiono się przede wszystkim na opracowaniu otrzymanych wyników i wyciągnięciu

  • Analiza procesów cieplnych zachodzących w skraplaczu płaszczowo-rurowym
    • Blanka Jakubowska
    2020 Ciepłownictwo, Ogrzewnictwo, Wentylacja

    W artykule przedstawiony został algorytm obliczeń cieplnych skraplacza płaszczowo- rurowego. Ten wymiennik ciepła wpływa na efektywność działania całego układu, w którym jest zastosowany. Z tego powodu, dobór odpowiedniego wymiennika do całej instalacji nie jest prosty i jest ściśle związany z szeregiem założeń projektowych, które znacząco wpływają na poprawną pracę urządzenia oraz całej instalacji. Prawidłowe określenie współczynników przejmowania ciepła podczas przepływu czynników stanowi jedno z najtrudniejszych zagadnień projektowych, zwłaszcza w przypadku, gdy w wymienniku występuje przemiana fazowa czynnika. Z tego względu, w niniejszym artykule największą uwagę poświęcono temu zagadnieniu, oraz przedstawiono algorytm obliczeń pozwalający na wyznaczanie współczynnika przejmowania ciepła w przepływie dwufazowym. W celu modelowania procesu skraplania w przepływie wybrano cztery modele opisujące to zjawisko, tj. model: Shaha, Akersa i innych, Cavalliniego i Zecchina oraz Boyko i Kruzhilina. Dodatkowo, do problemów natury projektowej, można zaliczyć m.in. założenia związane z doborem odpowiedniego płynu roboczego; w związku z tym w artykule przedstawiono również wpływ rodzaju skraplającego się czynnika na rozkład współczynników przejmowania ciepła w przepływie dwufazowym. W celu przeprowadzenia analizy wpływu rodzaju czynnika roboczego na proces skraplania w analizowanym wymienniku do rozważań przyjęto dziewięć różnych czynników, tj. R22, R32, R134a, R1234yf, R1234ze, R290 (propan), R600a (izobutan), R1270 (propylen) oraz R717 (amoniak).

  • ANALIZA PRZEBIEGÓW ZMIAN TEMPERATURY CZYNNIKA ROBOCZEGO W CYLINDRZE ORAZ KANALE SPALIN WYLOTOWYCH SILNIKA O ZS DLA POTRZEB DIAGNOSTYCZNYCH - STAN BADAŃ
    • Patrycja Puzdrowska
    2020 Pełny tekst Journal of Polish CIMEEAC

    Charakter przebiegów zmian ciśnienia i temperatury czynnika roboczego w silniku o zapłonie samoczynnym jest istotnym źródłem informacji diagnostycznych. Pozwalają na analizę stanu technicznego zarówno aparatury paliwowej jak i układu cieplno - przepływowego. Dotyczy to zarówno temperatury i ciśnienia gazów w czasie całego cyklu pracy silnika o ZS wewnątrz cylindra, jak i tych samych parametrów dotyczących spalin, rejestrowanych w kanale wylotowym. W niniejszym artykule przedstawiono wymienione powyżej przebiegi, zarówno te o charakterze teoretycznym lub analitycznym, jak i powstałe w rezultacie badań obiektów rzeczywistych. Poddano analizie porównawczej przebiegi teoretyczne i rzeczywiste, w przestrzeni wewnątrzcylindrowej i w kanale spalin wylotowych oraz omówiono przyczyny różnic pomiędzy nimi. Wskazano i omówiono czynniki mające największy wpływ na te różnice. Przeanalizowano przyczyny przesunięcia wartości maksymalnej temperatury względem maksymalnego ciśnienia w obrębie jednego cyklu pracy silnika o ZS.

  • Analiza ruchu drogowego z wykorzystaniem analizy akustycznej
    • Karolina Marciniuk
    • Bożena Kostek
    2020 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    Tematyka pracy porusza zagadnienia dotyczące pozyskiwania informacji o ruchu drogowym z wykorzystaniem monitoringu akustycznego. Przybliżono podstawowe techniki nadzoru nad ruchem drogowym. Przedstawiono założenia akustycznego detektora ruchu i zbadano jego skuteczność na trzech płaszczyznach działania – zliczania pojazdów, klasyfikacji rodzajowej i klasyfikacji warunków pogodowych panujących na nawierzchni

  • Analiza zastosowania gumowych słupków na przejściach przez dwupasowe drogi jednokierunkowe do poprawy brd
    • Joanna Wachnicka
    • Filip Ropiński
    2020 Pełny tekst Transport Miejski i Regionalny

    Bezpieczeństwo pieszych w Polsce, mimo prowadzonych wielu działań systemowych, nadal pozostawia wiele do życzenia i jest na niepokojąco niskim poziomie. W roku 2018 prawie 24% wypadków stanowiły wypadki z pieszymi, a udział ofiar śmiertelnych w nich stanowi od wielu lat niezmiennie około 30% pieszych. W celu zwiększenia bezpieczeństwa na przejściach dla pieszych znajdujących się na jezdniach o przekroju 2 x 2 zaczęto niedawno stosować rozwiązanie polegające na zastosowaniu gumowych słupków na jezdni przed przejściem. W niniejszym artykule przedstawiono wyniki badania zachowań pieszych i kierowców przed i po zastosowaniu takiego rozwiązania na jednej z ulic w Gdańsku. Jako metodę badawczą zastosowano wideorejestrację wraz z cyfrową i wzrokową analizą obrazu oraz badania ankietowe. Z analiz wynika, że kierowcy zredukowali swoją prędkość na dojeździe do przejścia o 15 %, jednak nadal pojawiały się sytuacje wyprzedzania jednego pojazdu, który zatrzymał się, by przepuścić pieszego, przez drugi pojazd. Wykonana modernizacja zniechęciła wyraźnie pieszych do przekraczania jezdni poza przejściem „na ukos” i zwłaszcza młodzi piesi ocenili badane rozwiązanie za poprawiające bezpieczeństwo pieszych.

  • Analiza zmienności generacji energii elektrycznej w 2019 r. ze szczególnym uwzględnieniem generacji energii ze źródeł wiatrowych II połowa roku i okres pandemii w 2020 jako czynnik nieprzewidywalny
    • Rafał Hyrzyński
    • Badur Janusz
    • Bartosz Kraszewski
    • Paweł Ziółkowski
    • Waldemar Dudda
    2020 Pełny tekst Nowa Energia

    W artykule przedstawiono zagadnienia związane z szeroko pojętym rozwojem energetyki wiatrowej. Omówiono stan rozwoju energetyki wiatrowej na świecie. Na podstawie dostępnych badań przybliżono także zagadnienia związane z czynnikami wpływającymi na rozwój odnawialnych źródeł energii oraz ich oddziaływania na środowisko naturalne. Główny nacisk położono jednakże na analizę zjawisk w pracy Krajowego Systemu Elektroenergetycznego (KSE) w okresie od 1 stycznia 2019 r. do dnia 31 grudnia 2019 r.

  • Analysis
    • Gertrud Morlock
    • Andrzej Wasik
    • Benno Zimmermann
    2020

    New food products and diverse formulations containing the regulated steviol glycoside(s) as well as Stevia extracts or Stevia leaves have been brought on the global market. The upcoming multitude of such food products, but also their falsification and adulteration, does have impact on food analysis. Robust high-throughput methods that cope with different food matrices are required for food control to ensure food safety. The analysis of steviol glycosides is mainly performed by high-performance liquid chromatography or high-performance thin-layer chromatography (HPTLC). Mass spectrometry is used for detection, when evaluation of the UV absorbance was challenging due to matrix interferences. HPTLC methods used a simple derivatization step to detect selectively the steviol glycosides. If needed, the recording of mass spectra followed. Further techniques like capillary electrophoresis, near infrared spectroscopy, nuclear magnetic resonance spectroscopy, enzymatic and electroanalytical methods have been reported. Among others, performance data, efficiency, robustness with regard to different sample matrices and relevant sample preparations were discussed. Important analytical techniques were compared with regard to routine analysis.

  • Analysis of a caustic formed by a spherical reflector: Impact of a caustic on architectural acoustics
    • Andrzej Kulowski
    2020 Pełny tekst APPLIED ACOUSTICS

    Focusing sound in rooms intended for listening to music or speech is an acoustic defect. Design recommendations provide remedial steps to effectively prevent this. However, there is a category of objects of high historical or architectural value in which the sound focus correction is limited or even abandoned. This also applies to indoor or outdoor concert shells, installations for teaching and acoustic presentations, etc. The main content of this article is deriving the equation of a caustic created by a concave hemispherical reflector with a source of rays situated at a given position. It is explained why under real conditions, both indoors and outdoors, no clear caustic resulting from the geometric approach is observed. Instead, its blurred form is perceived, usually limited to the caustic cusp taking the form of a point-like sound focus. This can be attributed to the effect of diffraction and interference, the impact of which on a caustic is analyzed in the paper.

  • Analysis of chiral pharmaceutical residues in influent and effluent samples at racemic and enantiomeric level using liquid chromatography-tandem mass spectrometry
    • Aysegul Dogan
    • Dagmara Kempińska-Kupczyk
    • Paweł Kubica
    • Agata Kot-Wasik
    2020 Pełny tekst MICROCHEMICAL JOURNAL

    In this work, two different chromatographic methods for seasonal monitoring of pharmaceutical residue in wastewater samples were developed. In the case of enantiomeric separation of selected compounds, LC-MS technique combining with vancomycin based chiral stationary phase was used. The performance of chiral analysis enabled to monitor the pharmaceutical contamination at the enantiomeric level. The d-SPE procedure was developed as sample preparation step and compared with SPE protocol in terms of recoveries and environmental friendliness. Due to satisfactory recoveries (around 60%) and greener character assessed using GAPI and AGREE tools, d-SPE-LC-MS/MS method was applied in further analysis. The concentration of detected enantiomers in wastewater collected in different seasons did not exceed 10 µg L−1, whereas the evaluated EF values were generally in the range of 0.4–0.7. Moreover, no significant changes in EF values after wastewater treatment were observed.

  • Analysis of Corrugated Coaxial Line with the Use of Body of Revolution and Finite Element Method
    • Sebastian Dziedziewicz
    • Rafał Lech
    • Piotr Kowalczyk
    2020

    A combination of the body-of-revolution and finite element methods is utilized to the analysis of coaxial lines with corrugated rod and wall. Both periodic and non-periodic structures can be investigated. As the structure is axially symmetrical the two dimensional scalar-vector finite element method can be used, which allows for the investigation of complex geometries and is computationally efficient. A generalized impedance matrix at the line ports is calculated from which the scattering parameters are derived. A few examples of corrugated coaxial lines have been analyzed and the results were compared to those obtained from commercial software.

  • Analysis of electricity generation variability in 2019 with special consideration of electrical energy generation from wind sources.
    • Sylwia Kruk-Gotzman
    • Paweł Ziółkowski
    • Janusz Badur
    2020 Pełny tekst

    This article presents issues related to the broadly understood development of wind energy. The state of the art of wind energy in the world has been discussed. This paper also shows issues related to factors affecting the development of renewable energy sources and their impact on the natural environment on the basis of available research. The focus is, however, on the critical analysis of phenomena in the data of the Transmission System Operator (TSO) in the period from 1 January 2019 to 31 December 2019. This analysis concentrates primarily on capturing the correlation between demand for TSO power capacity and the electrical power output generated by wind farms. As part of the article, specific operating condition for the TSO has been presented, in particular from the point of view of generating energy by wind sources. These were the days of 2019, in which there occurred: the maximum national demand for electricity of 26,136 MW, the minimum national demand for capacity of 11,400 MW, the maximum generation of power from wind farms of 5,222 MW, the minimum generation of power from wind farms of 5,222 MW and maximum hourly variability of wind farm generation - a decrease by 954 MW. The presented work closes with a forecast indicating the need to invest in making conventional generating units more flexible as well as in increasing the system’s installed capacity. The article does not take up issues related to power system security.

  • Analysis of flat compensator lapping in an assembly process
    • Adam Barylski
    2020 Technologia i Automatyzacja Montażu

    Przedstawiono sposób analizy docierania kompensatora płaskiego podczas montażu połączenia konstrukcyjnego. Wyznaczono czas główny obróbki i koszty operacji docierania jednotarczowego

  • Analysis of free‐air anomalies on the seaway of the Gulf of Gdańsk. A case study
    • Krzysztof Pyrchla
    • Małgorzata Pająk
    • Jerzy Pyrchla
    • Jakub Idczak
    2020 Pełny tekst Earth and Space Science

    In this paper, we present an attempt to determine the accuracy of shipborne gravimetry for the needs of geoid determination. The shipborne gravity campaign, described in this article, is the beginning of a series of gravimetry measurements in the Polish Exclusive Economy Zone. The campaign was conducted in the area where the accuracy of geoid determination is crucial for the safety of navigation on numerous intersecting ships routes. The vicinity of the seashore, various depths and short-lasting campaign enabled determination of the level of measurement accuracy that can be obtained depending on the conditions. Inter n al d at a consistency was estimated as well as an attempt to compute external accuracy. The data were compared with satellite data available for the region. We identified which of the dierences are related to the influence of external factors.

  • Analysis of hull, propeller and engine interactions in regular waves by a combination of experiment and simulation
    • Mohammad Ghaemi
    • Hamid Zeraatgar
    2020 Pełny tekst JOURNAL OF MARINE SCIENCE AND TECHNOLOGY

    Analysis of hull, propeller and engine interactions in regular waves by a combination of experiment and simulation

  • Analysis of Modal Parameters Using a Statistical Approach for Condition Monitoring of the Wind Turbine Blade
    • Łukasz Doliński
    • Marek Krawczuk
    2020 Pełny tekst Applied Sciences-Basel

    The primary objective of the presented paper is the numerical and experimental investigation related to developing a useful diagnostic method, which can be used for determining the site and size of damage in laminated shells of wind turbine blades. The described detection technique is based on the analysis of low frequencies bending vibrations mode shapes of rotor blades. The authors used the commonly applied statistics methods that have been adapted to detect edges of damage, including the normalized determination coefficient fit, which is a measure of the absolute fit between two curves. The research was conducted for a scaled-down blade of a three-bladed horizontal-axis wind turbine with 36 m diameter rotor. The study was divided into two parts. The first stage included numerical calculations using the finite element method, which were supplemented in the second stage by measurements under laboratory conditions of the specially manufactured composite blade. The forms of natural vibrations for intact and damaged blade were determined using Laser Doppler Scanning Vibrometry. The results of the presented research confirm the effectiveness of the modal analysis combined with statistic calculation in damage detection. The method points out the location of relatively small damage.

  • Analysis of positioning methods using Global Navigation Satellite Systems (GNSS) in Polish State Railways (PKP)
    • Mariusz Specht
    • Jacek Szmagliński
    • Cezary Specht
    • Władysław Koc
    • Andrzej Wilk
    • Krzysztof Czaplewski
    • Krzysztof Karwowski
    • Paweł Dąbrowski
    • Piotr Chrostowski
    • Sławomir Grulkowski
    2020 Pełny tekst Zeszyty Naukowe Akademii Morskiej w Szczecinie

    Each year, global navigation satellite systems (GNSS) improve their accuracy, availability, continuity, integrity, and reliability. Due to these continual improvements, the systems are increasingly used in various modes of transport, including rail transport, the subject of this publication. GNSS are used for rail passenger information, rail traffic management, and rail traffic control. These applications differ in the positioning requirements that satellite navigation systems must meet. This article presents the methods and systems of rolling stock location and tracking using the Polish State Railways (PKP) as an example. The information on the equipment used for train positioning is not specified anywhere, hence they may differ, even for the same multiple units travelling in different parts of the country. In addition, the publication presents the progress of the European Train Control System (ETCS) implementation by the PKP.

  • Analysis of the Dynamic Height Distribution at the Estuary of the Odra River Based on Gravimetric Measurements Acquired with the Use of a Light Survey Boat—A Case Study
    • Jerzy Pyrchla
    • Krzysztof Pyrchla
    • Paulina Kowalska
    • Arkadiusz Tomczak
    • Grzegorz Zaniewicz
    2020 Pełny tekst SENSORS

    LaCoste) for determining the dynamic height along the Odra River, in northwest Poland. The gravity measurement campaign described in this article was conducted on a small, hybrid-powered survey vessel (overall length: 9.5 m). We discuss a method for processing the results of gravimetric measurements performed on a mobile platform affected by strong external disturbances. Because measurement noise in most cases consists of signals caused by non-ideal observation conditions, careful attempts were made to analyze and eliminate the noise. Two different data processing strategies were implemented, one for a 20 Hz gravity data stream and another for a 1 Hz data stream. A comparison of the achieved results is presented. A height reference level, consistent for the entire estuary, is critical for the construction of a safe waterway system, including 3D navigation with the dynamic estimation of under-keel clearance on the Odra and other Polish rivers. The campaign was conducted in an area where the accuracy of measurements (levelling and gravimetric) is of key importance for shipping safety. The shores in the presented area of interest are swampy, so watercraft-based measurements are preferred. The method described in the article can be successfully applied to measurements in all near-zero-depth areas.

  • Analysis of the radiation dose in UV-disinfection flow reactors.
    • Wojciech Artichowicz
    • Aneta Łuczkiewicz
    • Jerzy Sawicki
    2020 Pełny tekst Water

    Theoretical considerations devoted to the variation of UV radiation doses in flow disinfection reactors are presented. The minimal time required by the fluid to pass the reactor was determined and combined with the radiation intensity. The active zones of the reactor were determined.

  • Analysis of the Ways to Identify Rail Running Surface Defects by Means of Vibration Signals
    • Roksana Licow
    • Franciszek Tomaszewski
    2020 Pełny tekst Problemy Kolejnictwa

    Th e article discusses a preliminary concept of a method enabling the identifi cation of chosen rail running surface defects, such as squats, spalling, and running surface defects, by analysing the parameters of vibration signals. It features a description of the methodology of the conducted tests, the scope thereof, and the selection of the measurement points with specifi c defect types. Th e article covers selected results of vibration tests, the results of analyses of recorded signals for defective track sections and those for control track sections. Th e presented measurement results have been obtained for the technical–operating conditions occurring on railway line no. 213 Reda – Hel and line no. 131 Chorzów Batory – Tczew. Th e preliminary test results and conclusions included in the article show that it is reasonable to pursue further research into the phenomena involving the utilisation of vibroacoustics in rail performance diagnostics.

  • Analysis of ultimate compressive strength of cracked plates with the use of DOE techniques
    • Krzysztof Wołoszyk
    • Yordan Garbatov
    2020 Pełny tekst Polish Maritime Research

    The objective of this work is to investigate the structural compressive response of plates with locked cracks accounting for all relevant factors and correlation between them. The nonlinear FE model considering both geometric and material nonlinearities is employed herein, and the FE model of the structural response of intact plates is validated with the available experimental data. In the common studies, based on One Factor at a Time analysis, some of the parameters and interactions between them are excluded. In the present study, the numerical investigations are conducted with the use of the Design of Experiments techniques, where all essential parameters and their interactions are adequately considered. With a total of 32 numerical analyses, the most influential factors and their interactions are identified. As a study outcome, empirical formulations, which allow for a fast estimation of the ultimate compressive strength of intact plates, plates with locked cracks, and repaired cracked plates, are derived. The developed formulations represent a fast and practical tool for estimating the ultimate compressive strength of intact, cracked, and repaired plates, which can be easily employed in the reliability analysis.

  • Analysis of Validation and Simplification of Timber-Frame Structure Design Stage with PU-Foam Insulation
    • Marcin Szczepański
    • Wojciech Migda
    2020 Pełny tekst Sustainability

    The transition from experimental studies to the realm of numerical simulations is often necessary for further studies, but very difficult at the same time. This is especially the case for extended seismic analysis and earthquake-resistant design. This paper describes an approach to moving from the experimental testing of an elementary part of a wood-frame building structure to a numerical model, with the use of a commercial engineering analysis software. In the presented approach, a timber-frame structure with polyurethane (PU)-foam insulation and OSB (oriented strand board) sheathing was exposed to dynamic excitation. The results were then used to generate a numerical 3D model of the wooden frame element. The process of creating the 3D model is explained with the necessary steps to reach validation. The details of the model, material properties, boundary conditions, and used elements are presented. Furthermore, the authors explain the technical possibilities for simplifying the numerical model in used software. Simplifying the model leads to a substantial reduction of calculation time without the loss of accuracy of results. Such a simplification is especially useful when conducting advanced numerical calculations in the field of seismic and dynamic resistant object design.

  • Analysis of Vibration and Acoustic Signals for Noncontact Measurement of Engine Rotation Speed
    • Shan Xuansheng
    • Tang Lu
    • He Wen
    • Radek Martinek
    • Janusz Smulko
    2020 Pełny tekst SENSORS

    The non-contact measurement of engine speed can be realized by analyzing engine vibration frequency. However, the vibration signal is distorted by harmonics and noise in the measurement. This paper presents a novel method for the measurement of engine rotation speed by using the cross-correlation of vibration and acoustic signals. This method can enhance the same frequency components in engine vibration and acoustic signal. After cross-correlation processing, the energy centrobaric correction method is applied to estimate the accurate frequency of the engine’s vibration. This method can be implemented with a low-cost embedded system estimating the cross-correlation. Test results showed that this method outperformed the traditional vibration-based measurement method.

  • Analytical calculations of scattering lengths for a class of long-range potentials of interest for atomic physics
    • Radosław Szmytkowski
    2020 Pełny tekst JOURNAL OF MATHEMATICAL PHYSICS

    We derive two equivalent analytical expressions for an $l$th partial-wave scattering length $a_{l}$ for central potentials with long-range tails of the form % \begin{math} \displaystyle V(r)=-\frac{\hbar^{2}}{2m}\frac{Br^{n-4}}{(r^{n-2}+R^{n-2})^{2}} -\frac{\hbar^{2}}{2m}\frac{C}{r^{2}(r^{n-2}+R^{n-2})}, \end{math} % ($r\geqslant r_{s}$, $R>0$). % For $C=0$, this family of potentials reduces to the Lenz potentials discussed in a similar context in our earlier works [Acta Phys. Pol.\ A 79 (1991) 613 and J.\ Phys.\ A 28 (1995) 7333]. The formulas for $a_{l}$ which we provide in this paper depend on the parameters $B$, $C$ and $R$ characterizing the tail of the potential, on the core radius $r_{s}$, as well as on the short-range scattering length $a_{ls}$, the latter being due to the core part of the potential. The procedure, which may be viewed as an analytical extrapolation from $a_{ls}$ to $a_{l}$, is relied on the fact that the general solution to the zero-energy radial Schr{\"o}dinger equation with the potential given above may be expressed analytically in terms of the \emph{generalized\/} associated Legendre functions.

  • Analyzing and Visualizing Government-Citizen Interactions on Twitter to Support Public Policy-making
    • Rocio Hubert
    • Elsa Estevez
    • Ana Maguitman
    • Tomasz Janowski
    2020 Pełny tekst Digital Government: Research and Practice

    Twitter is widely adopted by governments to communicate with citizens. It has become a major source of data for analyzing how governments communicate with citizens and how citizens respond to such communication, uncovering important insights about government-citizen interactions that could be used to support public policy-making. This article presents research that aims at developing a software tool called Twitter Analytics for Government Intelligence and Public Participation (TA4GIP) that applies sentiment analysis and visualization techniques to information collected from Twitter and presents the findings to policy-makers and other non-technical users to facilitate understanding and interpretation. The use of the tool is illustrated through the case study of Twitter communication carried by five government secretaries responsible for health, education, social development, labor, and environment sectors in Mexico, and corresponding citizen responses over a nine-month period. The case study demonstrates that TA4GIP helps identify and analyze relevant aspects of government presence and citizen participation on social media, such as abnormal activity, salient topics being discussed, citizen views about enacted public policies, correlations between types of emotions in responses to particular government announcements, topics that generate polarized reactions from citizens, and many others.

  • Analyzing the Effectiveness of the Brain–Computer Interface for Task Discerning Based on Machine Learning
    • Jakub Browarczyk
    • Adam Kurowski
    • Bożena Kostek
    2020 Pełny tekst SENSORS

    The aim of the study is to compare electroencephalographic (EEG) signal feature extraction methods in the context of the effectiveness of the classification of brain activities. For classification, electroencephalographic signals were obtained using an EEG device from 17 subjects in three mental states (relaxation, excitation, and solving logical task). Blind source separation employing independent component analysis (ICA) was performed on obtained signals. Welch’s method, autoregressive modeling, and discrete wavelet transform were used for feature extraction. Principal component analysis (PCA) was performed in order to reduce the dimensionality of feature vectors. k-Nearest Neighbors (kNN), Support Vector Machines (SVM), and Neural Networks (NN) were employed for classification. Precision, recall, F1 score, as well as a discussion based on statistical analysis, were shown. The paper also contains code utilized in preprocessing and the main part of experiments.

  • Analyzing the Impact of Simulated Multispectral Images on Water Classification Accuracy by Means of Spectral Characteristics
    • Krystyna Michałowska
    • Ewa Głowienka
    2020 Pełny tekst Geomatics and Environmental Engineering

    Remote sensing is widely applied in examining the parameters of the state and quality of water. Spectral characteristics of water are strictly connected with the dispersion of electromagnetic radiation by suspended matter and the absorp-tion of radiation by water and chlorophyll a and b.Multispectral sensor ALI has bands within the ranges of electromagnetic radia-tion: blue and infrared, absent in sensors such as Landsat, SPOT, or Aster. The main goal of the article was to examine the influence of the presence of these bands on water classification accuracy carried out for simulated images ALI, Landsat, Spot, and Aster. The simulation of images was based on the hyper-spectral image from a Hyperion sensor. Due to the spectral properties of water, all the operations on the images were carried out for the set of bands in visible and near-infrared (VNIR) spectral range. In the framework of these studies, the impact of removing individual bands or sets of bands on the classification results was tested. Tests were carried out for the area of the water body of the Dobczyce Reservoir. It was observed that the lack of a spectral response in the infrared range of ALI image can reduce the accuracy of a classification by as much as 60%. On the other hand, the lack of blue and red bands in the data-set for the classification decreased the accuracy of water classification by 15% and 10%, respectively.

  • ANALYZING TITLES OF ECONOMY NEWS TO UNDERSTAND IMPACT OF COVID-19 ON ECONOMICAL SITUATION
    • Olgun Aydin
    • Cansu Altunbas
    • Elvan Hayat
    2020

    Covid-19 affected the whole world in a short time, causing serious panic and uncertainty in society. Because it was an unprecedented disease, the medical community has worked hard to find out how to deal with it, and it continues to do so. The rapid spread of the disease, the shortage of hospital capacity and the increase in deaths drove the whole world to a closure, so to speak. In this time period, life in the world came to a halt. This also brought along many problems in terms of global economy. Many businesses announced their bankruptcy, many people were unemployed. Although the governments launched support packages, the lockdown caused huge damage to the global economy. In the light of this information, while studies continue intensively in the fields of medicine, chemistry and biology, researchers have accelerated their studies in fields such as data science, data analysis and open data as well. Within the scope of this study, in order to monitor and analyze the effects of Covid-19 on the economy, the economy news titles in the relevant period were collected and analyzed in detail using text mining techniques, and it was aimed to propose an alternative perspective to analyze the effect of the virus on the global economy.

  • Anodic titania nanotubes decorated with gold nanoparticles produced by laser-induced dewetting of thin metallic films
    • Katarzyna Grochowska
    • Nikolay Nedyalkov
    • Jakub Karczewski
    • Łukasz Haryński
    • Gerard Śliwiński
    • Katarzyna Siuzdak
    2020 Pełny tekst Scientific Reports

    Herein, we combine titania layers with gold species in a laser-supported process and report a substantial change of properties of the resulting heterostructures depending on the major processing parameters. Electrodes were fabricated via an anodisation process complemented with calcination to ensure a crystalline phase, and followed by magnetron sputtering of metallic films. The obtained TiO2 nanotubes with deposited thin (5, 10 nm) Au films were treated with a UV laser (355 nm) to form Au nanoparticles on top of the nanotubes. It was proven that selected laser working parameters ensure not only the formation of Au nanoparticles, but also simultaneously provide preservation of the initial tubular architecture, while above-threshold laser fluences result in partial destruction (melting) of the top layer of the nanotubes. For almost all of the samples, the crystalline phase of the nanotubes observed in Raman spectra was maintained independently of the laser processing parameters. Enhanced photoresponse up to ca 6 mA/cm2 was demonstrated by photoelectrochemical measurements on samples obtained by laser annealing of the 10 nm Au coating on a titania support. Moreover, a Mott–Schottky analysis indicated the dramatically increased (two orders of magnitude) concentration of donor density in the case of a laser-treated Au–TiO2 heterojunction compared to reference electrodes.

  • Antenna Modeling Using Variable-Fidelity EM Simulations and Constrained Co-Kriging
    • Anna Pietrenko-Dąbrowska
    • Sławomir Kozieł
    2020 Pełny tekst IEEE Access

    Utilization of fast surrogate models has become a viable alternative to direct handling of fullwave electromagnetic (EM) simulations in EM-driven design. Their purpose is to alleviate the difficulties related to high computational cost of multiple simulations required by the common numerical procedures such as parametric optimization or uncertainty quantification. Yet, conventional data-driven (or approximation) modeling techniques are severely affected by the curse of dimensionality. This is a serious limitation when it comes to modeling of highly nonlinear antenna characteristics. In practice, general-purpose surrogates can be rendered for the structures described by a few parameters within limited ranges thereof, which is grossly insufficient from the utility point of view. This paper proposes a novel modeling approach involving variable-fidelity EM simulations incorporated into the recently reported nested kriging modeling framework. Combining the information contained in the densely sampled low- and sparsely sampled highfidelity models is realized using co-kriging. The resulting surrogate exhibits the predictive power comparable to the model constructed using exclusively high-fidelity data while offering significantly reduced setup cost. The advantages over conventional surrogates are pronounced even further. The presented modeling procedure is demonstrated using two antenna examples and further validated through the application case studies.

  • Anticancer Imidazoacridinone C-1311 is Effective in Androgen-Dependent and Androgen-Independent Prostate Cancer Cells
    • Magdalena Niemira
    • Barbara Borowa-Mazgaj
    • Samuel B. Bader
    • Adrianna Moszyńska
    • Marcin Ratajewski
    • Kaja Karaś
    • Mirosław Kwaśniewski
    • Adam Krętowski
    • Zofia Mazerska
    • Ester M. Hammond
    • Anna Skwarska
    2020 Pełny tekst Biomedicines

    Androgen receptor (AR) plays a crutial role in prostate cancer (PCa) development and metastasis. Here, we reported potent anti-PCa activity of a small molecule imidazoacridinone C-1311. In AR-positive PCa cells, C-1311 was found to inhibit the transcriptional activity of AR uncovering a novel mechanism that may be relevant for its anticancer effect. Mechanistically, C-1311 decreased AR binding to prostate-specific antigen (PSA) promoter, reduced PSA protein level, and as shown by transcriptome sequenvcing, down-regulated numerous AR target genes. Importantly, AR-negative PCa cells were also sensitive to C-1311, suggesting a promising efficacy in androgen-independent PCa sub-type. Irrespective of AR status, C-1311 induced DNA damage, arrested cell cycle progression and induced apoptosis. RNA sequencing indicated on the significant differences in transcriptional response to C-1311 between PCa cells. Gene ontology analysis showed that in AR-dependent PCa cells, C-1311 mainly affected DNA damage response pathways. In contrast, in AR-independent PCa cells, C-1311 targeted cellular metabolism and inhibited gene regulating glycolysis and gluconeogenesis. Together, these results indicate that C-1311 warrants further development for the treatment of PCa.

  • Antimony substituted lanthanum orthoniobate proton conductor – structure and electronic properties.
    • Aleksandra Mielewczyk-Gryń
    • Sebastian Wachowski
    • Agnieszka Witkowska
    • Kacper Dzierzgowski
    • Wojciech Skubida
    • Konrad Świerczek
    • Anna Regoutz
    • David J. Payne
    • Stephen Hull
    • Hangfeng Zhang
    • Isaac Abrahams
    • Maria Gazda
    2020 JOURNAL OF THE AMERICAN CERAMIC SOCIETY

    X‐ray and neutron diffraction have been utilized to analyze the crystalline and electronic structure of lanthanum orthoniobate substituted by antimony. Using X‐ray absorption spectroscopy and photoelectron spectroscopy, changes in the electronic structure of the material upon substitution have been analyzed. The structural transition temperature between fergusonite and scheelite phases for 30 mol% antimony substitution was found to be 15 °C. Based on the neutron data, the oxygen nonstoichiometry was found to be relatively low. Moreover, no influence on the position of the valence band maximum was observed. The influence of the protonation on the electronic structure of constituent oxides has been studied. Absorption data show that the incorporation of protonic defects into the lanthanum orthoniobate structure leads to changes in lanthanum electronic structure and a decrease in the density of unoccupied electronic states.

  • Application of 3D printing metal powder technology in the manufacture of components with complex geometries
    • Mariusz Deja
    • Dawid Zieliński
    2020 Pełny tekst Mechanik

    The possibilities of using 3D printing powder technologies for making objects with complex geometries were presented. For this purpose, selected examples of elements with different geometries were used, which were built using metal powder methods – DMLS (direct metal laser sintering) / SLM (selective laser melting). Simultaneously, the indicated elements concern those areas of industry where 3D printing technology has been widely used in recent years, i.e. maritime and aerospace industries. Also, the metal 3D printing process was characterized by a description of the particular stages of model building. The directions of further development of the above mentioned 3D printing methods and the areas of possible applications of the 3D printed parts were presented, respectively.

  • Application of Analytic Signal and Smooth Interpolation in Pulse Width Modulation for Conventional Matrix Converters
    • Paweł Szczepankowski
    • Patrick Wheeler
    • Tomasz Bajdecki
    2020 Pełny tekst IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS

    The paper proposes an alternative and novel approach to the PWM duty cycles computation for Conventional Matrix Converters (CMC) fed by balanced, unbalanced or non–sinusoidal AC voltage sources. The presented solution simplifies the prototyping of direct modulation algorithms. PWM duty cycles are calculated faster by the smooth interpolation technique, using only vector coordinates, without trigonometric functions and angles. Both input voltages and output reference voltages are expressed by analytic signals in the proposed direct modulation. Input voltages are represented by the rotating vector collection in the two–dimensional Cartesian coordinate system. All reference output voltages are located inside the triangular surface, named here as the voltage synthesis field, formed by these rotating vectors. A certain degree of reference signals placement freedom allows to maximize the voltage transfer ratio to 0:866 with less switching compared to the Optimum–Venturini direct method. The proposed solution was verified by simulations and experiments for CMC3xk. The comparison with the Optimum–Venturini modulation is included. The proposed PWM duty cycle computation approach can also be applied to multiphase CMC converters for any number of inputs as well as outputs.

  • APPLICATION OF APRIORI ALGORITHM IN THE LAMINATION PROCESS IN YACHT PRODUCTION
    • Tacjana Niksa-Rynkiewicz
    • Michał Landowski
    • Paweł Szalewski
    2020 Pełny tekst Polish Maritime Research

    The article specifies the dependence of defects occurring in the lamination process in the production of yachts. Despite great knowledge about their genesis, they cannot be completely eliminated. Authentic data obtained through cooperation with one of the Polish yacht shipyards during the years 2013–2017 were used for the analysis. To perform a simulation, the sample size was observed in 1450 samples, consisting of 6 models of yachts with closed and open deck. Finding the dependence of the occurrence of specific defects will allow for faster procedures and more effective quality control, which will contribute to lower costs. The use of new methods based on artificial intelligence related to Big Data allows for easier observation of dependencies in the complex structure of data from yacht production. The association rules were defined using the algorithm Apriori and define interdependent defects. A number of dependencies were found for the occurrence of production defects not obvious to technologists, but occurring with a high probability of coexistence. The presented research results may allow the planning process of production tasks to be improved.

  • Application of BiOClnBrm photocatalyst to cytostatic drugs removal from water; mechanism and toxicity assessment
    • Patrycja Wilczewska
    • Andrea Elisabeth Natasha Ona
    • Aleksandra Bielicka-giełdoń
    • Anna Malankowska
    • Karol Tabaka
    • Jacek Ryl
    • Filip Pniewski
    • Ewa Siedlecka
    2020 Pełny tekst SEPARATION AND PURIFICATION TECHNOLOGY

    The photocatalytic activity of series of BiOClnBrm photocatalysts toward degradation and mineralization of the cytostatic drugs 5-fluorouracil (5-FU) and imatinib mesylate (IMA) both singly and in their mixture under simulated solar and visible light irradiation has been investigated. Screening test revealed that among BiOClnBrm photocatalysts synthesized by a solvothermal method, the one with molar 1.3Cl/0.7Br ratio was the most efficient in 5-FU removal under UV-Vis irradiation. The dose 200 mg L-1 and 6.3 pH were optimal to effective removal of 5-FU. The BiOCl1.3Br0.7 was successfully used to 5-FU and IMA removal singly and in their mixture under simulated solar and visible light irradiation. Scavenging experiments showed that h+ and •O2- were the major oxidative species participated in both drugs degradation. In presence of IMA, 5-FU removal was significantly depressed. In singly drug solutions and in the mixture of drugs, the presence of inorganic ions such as Cl−, SO42−, and NO3- significantly hindered 5-FU photocatalytic degradation, and increased the adsorption of IMA onto the photocatalyst surface in dark phase. The HCO3− anion, Fe3+ and Ag+ cations accelerated the 5-FU removal, while Ca2+ showed no impact on the process. The transformation products of 5-FU and IMA were identified by LC-MS revealing that hydroxylation and oxidation were the main transformation pathways, under the all studied systems. Some of intermediates were indicated for the first time in heterogeneous photocatalysis. The defluorination of 5-FU by the reaction with photogenerated e- was also possible. Furthermore, the alga toxicity assay was investigated using Chlorella vulgaris. A reduction of toxicity in effluents after photocatalytic degradation of both drugs singly and in their mixture was observed.

  • Application of Diffusion Models in the Analysis of Financial Markets: Evidence on Exchange Traded Funds in Europe
    • Ewa Lechman
    • Adam Marszk
    2020 Pełny tekst Risks

    Exchange traded funds (ETFs) are financial innovations that may be considered as a part of the index financial instruments category, together with stock index derivatives. The aim of this paper is to explore the trajectories and formulates predictions regarding the spread of ETFs on the financial markets in six European countries. It demonstrates ETFs’ development trajectories with regard to stock index futures and options that may be considered as their substitutes, e.g., in risk management. In this paper, we use mathematical models of the diffusion of innovation that allow unveiling the evolutionary patterns of turnover of ETFs; the time span of the analysis is 2004–2015, i.e., the period of dynamic changes on the European ETF markets. Such an approach has so far rarely been applied in this field of research. Our findings indicate that the development of ETF markets has been strongest in Italy and France and weaker in the other countries, especially Poland and Hungary. The results highlight significant differences among European countries and prove that diffusion has not taken place in all the cases; there are also considerable differences in the predicted development paths.

  • Application of Diversity Combining with RLS Adaptive Filtering in Data Transmission in a Hydroacoustic Channel
    • Agnieszka Czapiewska
    • Ryszard Studański
    • Andrzej Łuksza
    • Andrzej Żak
    2020 Pełny tekst SENSORS

    When transmitting data in a hydroacoustic channel under difficult propagation conditions, one of the problems is intersymbol interference (ISI) caused mainly by the effect of multipath propagation. This phenomenon leads to a decrease in transmission parameters, and sometimes completely prevents it. Therefore, we have made an attempt to use diversity combining with Recursive Least Squares (RLS) adaptive filtering to improve the quality of data transmission in a hydroacoustic channel with strong reflections. The method was tested in simulation and during measurements in a real environment. The influence of the method on data transmission in the hydroacoustic channel was examined in detail. The obtained results allow us to draw conclusions regarding the purposefulness of use of diversity combining and RLS adaptive filtering in order to improve the quality of data transmission by reducing the effect of ISI.

  • Application of Least Squares with Conditional Equations Method for Railway Track Inventory Using GNSS Observations
    • Krzysztof Czaplewski
    • Zbigniew Wiśniewski
    • Cezary Specht
    • Andrzej Wilk
    • Władysław Koc
    • Krzysztof Karwowski
    • Jacek Skibicki
    • Paweł Dąbrowski
    • Bartosz Czaplewski
    • Mariusz Specht
    • Piotr Chrostowski
    • Jacek Szmagliński
    • Sławomir Judek
    • Sławomir Grulkowski
    • Roksana Licow
    2020 Pełny tekst SENSORS

    Satellite geodetic networks are commonly used in surveying tasks, but they can also be used in mobile surveys. Mobile satellite surveys can be used for trackage inventory, diagnostics and design. The combination of modern technological solutions with the adaptation of research methods known in other fields of science offers an opportunity to acquire highly accurate solutions for railway track inventory. This article presents the effects of work carried out using a mobile surveying platform on which Global Navigation Satellite System (GNSS) receivers were mounted. The satellite observations (surveys) obtained were aligned using one of the methods known from classical land surveying. The records obtained during the surveying campaign on a 246th km railway track section were subjected to alignment. This article provides a description of the surveying campaign necessary to obtain measurement data and a theoretical description of the method employed to align observation results as well as their visualisation.

  • Application of mesh deformation for modeling of conformal RF components with 3D FEM
    • Maciej Jasiński
    • Adam Lamęcki
    • Michał Mrozowski
    2020 Pełny tekst

    In this paper, a method of analysis of conformal RF components has been proposed. In this approach, modeling of a curved structure is based on mesh deformation of planar objects rather than the construction of conformal geometry at CSG level. Since the model is represented as a 3D mesh, the deformation only requires the calculation of nodes position in the bent structure. The results of the proposed algorithm have been validated with simulation from other software and measurements, whereby method correctness has been confirmed