Repozytorium publikacji - Politechnika Gdańska

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Repozytorium publikacji
Politechniki Gdańskiej

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  • Proces ciągłego doskonalenia wśród laureatów XXIII edycji Konkursu o Pomorską Nagrodę Jakości
    • Anna Wendt
    2021

    Model doskonałości można zdefiniować jako zbiór zasad kompleksowej oceny organizacji, który często wykorzystywany jest jako podstawa konkursów jakości. Europejski Model Doskonałości EFQM pozwala na doskonalenie organizacji m.in. poprzez kompleksowe podejście, identyfikację mocnych i słabych stron organizacji czy zwiększenie zaangażowania pracowników w doskonalenie. Celem niniejszego referatu jest analiza działań doskonalących zidentyfikowanych u laureatów XXIII edycji Konkursu o Pomorską Nagrodę Jakości, który tak jak Polska Nagroda Jakości swoje zasady opiera na Modelu EFQM. Analiza raportów tych jednostek dowodzi, że organizacje na najwyższym poziomie skuteczności zarządzania stosują wiele metod i narzędzi, które pozwalają na ciągłe doskonalenie procesów. Podmioty te wykazują podejście systemowe, monitorują wszystkie procesy w organizacji. Cały czas też analizują potrzeby i oczekiwania klientów. Kierownictwo daje dobry przykład i angażuje pracowników do zmian poprzez m.in. różnego rodzaju systemy motywacyjne. Otrzymane nagrody i wyróżnienia stanowią potwierdzenie zaangażowania laureatów w procesy ciągłego doskonalenia organizacji.

  • Process of Medical Dataset Construction for Machine Learning-Multifield Study and Guidelines
    • Jan Cychnerski
    • Tomasz Dziubich
    2021

    The acquisition of high-quality data and annotations is essential for the training of efficient machine learning algorithms, while being an expensive and time-consuming process. Although the process of data processing and training and testing of machine learning models is well studied and considered in the literature, the actual procedures of obtaining data and their annotations in collaboration with physicians are in most cases based on the personal intuition and suppositions of the researchers.

  • Processing, Performance Properties, and Storage Stability of Ground Tire Rubber Modified by Dicumyl Peroxide and Ethylene-Vinyl Acetate Copolymers
    • Paulina Wiśniewska
    • Łukasz Zedler
    • Krzysztof Formela
    2021 Pełny tekst Polymers

    In this paper, ground tire rubber was modified with dicumyl peroxide and a variable content (in the range of 0–15 phr) of ethylene-vinyl acetate copolymers characterized by different vinyl acetate contents (in the range of 18–39 wt.%). Modification of ground tire rubber was performed via an auto-thermal extrusion process in which heat was generated during internal shearing of the material inside the extruder barrel. The processing, performance properties, and storage stability of modified reclaimed ground tire rubber were evaluated based on specific mechanical energy, infrared camera images, an oscillating disc rheometer, tensile tests, equilibrium swelling, gas chromatography combined with a flame ionization detector, and gas chromatography with mass spectrometry. It was found that the developed formulas of modified GTR allowed the preparation of materials characterized by tensile strengths in the range of 2.6–9.3 MPa and elongation at break in the range of 78–225%. Moreover, the prepared materials showed good storage stability for at least three months and satisfied processability with commercial rubbers (natural rubber, styrene-butadiene rubber).

  • Production of six-degrees-of-freedom (6DoF) navigable audio using 30 Ambisonic microphones
    • Bartłomiej Mróz
    • Marek Kabaciński
    • Tomasz Ciotucha
    • Andrzej Rumiński
    • Tomasz Żernicki
    2021

    This paper describes a method for planning, recording, and post-production of six-degrees-of-freedom audio recorded with multiple 3rd order Ambisonic microphone arrays. The description is based on the example of recordings conducted in August 2020 with the Poznan Philharmonic Orchestra using 30 units of Zylia ZM-1S. A convenient way to prepare and organize such a big project is proposed – this involves details of stage planning, collecting needed equipment, management, and running the recording. Additionally, the placement of 2D and 360 cameras as well as the design of moving camera paths are described. Two use cases of the collected Ambisonic audio are proposed. The first one is a production of a virtual reality application using Unreal Engine 4 and Wwise. The second one uses a combination of the virtual scene from the previously mentioned application and a footage from a mobile, moving camera to create a so-called “walkthrough movie”. The proposed approach for six-degrees-of-freedom Ambisonic interpolation was evaluated on listening tests. Those tests demonstrate that it is possible to recreate a navigable 3D audio taking into account Ambisonic only input and given assumptions for microphone placement.

  • Progress on Roman and Weakly Connected Roman Graphs
    • Joanna Raczek
    • Rita Zuazua
    2021 Pełny tekst Mathematics

    A graph G for which γR(G)=2γ(G) is the Roman graph, and if γwcR(G)=2γwc(G), then G is the weakly connected Roman graph. In this paper, we show that the decision problem of whether a bipartite graph is Roman is a co-NP-hard problem. Next, we prove similar results for weakly connected Roman graphs. We also study Roman trees improving the result of M.A. Henning’s A characterization of Roman trees, Discuss. Math. Graph Theory 22 (2002). Moreover, we give a characterization of weakly connected Roman trees.

  • PROJEKT STANOWISKA DYDAKTYCZNEGO DO WYZNACZANIA CHARAKTERYSTYK POMP WIROWYCH
    • Norbert Ochał
    2021 Pełny tekst Journal of Polish CIMEEAC

    W artykule przedstawiono projekt oraz gotowe stanowisko do wyznaczenia charakterystyk przepływowych pomp wirowych w pracy indywidualnej oraz w wybranych wariantach współpracy szeregowej jak i równoległej. Obserwację parametrów kontrolnych pomp wirowych w różnych stanach pracy: dławienie przepływu, zmiana prędkości obrotowej. Dużą zaletą stanowiska jest wymuszanie obserwację zjawiska kawitacji.

  • Projekt "Walizka"
    • Dominika Krechowicz
    2021

    Projekt "Walizka", koncepcja: prof. dr hab. Zbigniew Szot Uniwersytet Artystyczny w Poznaniu, Wydział Malarstwa i Rysunku. W projekcie wzięło udział 23 artystów z Polski oraz z Czech, Niemiec, Gruzji I Japonii. Koncepcja projektu dotyczy szeroko pojętego tematu podróży. W obecnych czasach zagrożenia COVID-19 słowo „podróż” zaczyna nabierać zupełnie innego znaczenia. Żyjąc i tworząc w izolacji od wielu miesięcy, została stworzona wspólnie autonomiczna kolekcja prac, dedykowanych tylko tej walizce, która teraz jest wysyłana w podróż. Prace i walizka stanowią nierozłączną całość. Koncepcją projektu jest zaprezentowanie prac w wybranych miejscach oraz pozostawienie swojego znaku na wieku walizki. Wystawa została zaprezentowana w Galerii Szewska 16 w Poznaniu w terminie 19.04 - 04.05. 2021.

  • Projektowanie ukierunkowane na prosumpcję. Koncepcja domu do samodzielnego montażu
    • Robert Idem
    • Stanisław Kempa
    • Katarzyna Zielonko-Jung
    2021 Pełny tekst Builder

    Idea prosumpcji polega na włączaniu przyszłego użytkownika w proces powstawania dobra, z którego będzie w przyszłości korzystał. Zjawisko to pojawia się w architekturze i budownictwie w niewielkim zakresie, jednak dynamiczny rozwój technologii w coraz większym stopniu tworzy możliwości dla takiego podejścia. W artykule poruszono ideę prosumpcji w odniesieniu do procesu wznoszenia budynku. Przedstawiono kierunki, które można wyodrębnić na podstawie analizy podejmowanych współcześnie prób samodzielnego budowania. Na ich tle zaprezentowano autorską koncepcję systemu pozwalającego wznosić obiekty o niewielkiej skali samodzielnie przez osoby nieposiadające wiedzy w zakresie budownictwa. Koncepcja powstała w ramach poszukiwań badawczych typu research by design. Studium obejmuje ogólną koncepcję systemu oraz projekt jego wykorzystania przy wzniesieniu domu mieszkalnego rekreacyjnego o powierzchni 35 m2. Projekt pozwolił autorom na wstępną ocenę jego możliwości i ograniczeń oraz przewidywania, w jaki sposób można je rozwijać.

  • Promising Nanoparticle-Based Heat Transfer Fluids—Environmental and Techno-Economic Analysis Compared to Conventional Fluids
    • Natalia Czaplicka
    • Anna Grzegórska
    • Jan Wajs
    • Joanna Sobczak
    • Andrzej Rogala
    2021 Pełny tekst INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    Providing optimal operating conditions is one of the major challenges for effective heating or cooling systems. Moreover, proper adjustment of the heat transfer fluid is also important from the viewpoint of the correct operation, maintenance, and cost efficiency of these systems. Therefore, in this paper, a detailed review of recent work on the subject of conventional and novel heat transfer fluid applications is presented. Particular attention is paid to the novel nanoparticle-based materials used as heat transfer fluids. In-depth comparison of environmental, technical, and economic characteristics is discussed. Thermophysical properties including thermal conductivity, specific heat, density, viscosity, and Prandtl number are compared. Furthermore, the possible benefits and limitations of various transfer fluids in the fields of application are taken into account.

  • Properties of Barium Cerate-Zirconate Thin Films
    • Piotr Winiarz
    • Monica Susana Covarrubias Campos
    • Mantas Sriubas
    • Kristina Bockute
    • Tadeusz Miruszewski
    • Wojciech Skubida
    • Daniel Jaworski
    • Giedrius Laukaitis
    • Maria Gazda
    2021 Pełny tekst Crystals

    In this work, we review several experimental results showing the electrical properties of barium cerate-zirconate thin films and discuss them in view of the possible influence of various factors on their properties. Most of the presented Ba(Ce, Zr, Y)O3 thin films were formed by the pulsed laser deposition (PLD) technique, however thin films prepared using other methods, like RF magnetron sputtering, electron-beam deposition, powder aerosol deposition (PAD), atomic layer deposition (ALD) and spray deposition are also reported. The electrical properties of the thin films strongly depend on the film microstructure. The influence of the interface layers, space-charge layers, and strain-modified layers on the total conductivity is also essential but in many cases is weaker.

  • Properties of Different Varieties of Durian
    • Supeeraya Arsa
    • Angkana Wipatanawin
    • Rachit Suwapanich
    • Orachorn Makkerdchoo
    • Niphattha Chatsuwan
    • Pensiri Kaewthong
    • Praphan Pinsirodom
    • Ruchira Taprap
    • Ratiporn Haruenkit
    • Sumitra Poovarodom
    • Martyna Lubinska-Szczygeł
    • Elena Katrich
    • Shela Gorinstein
    2021 Pełny tekst Applied Sciences

    Durian (Durio zibethinus Murr.), like many other exotic, tropical, and conventional fruits, is important in the prevention of different diseases. In this study, the characterization of the main bioactive compounds of the most popular cultivars of durian and their properties are described. The changes in the quality indices of the antioxidant status were determined by CUPRAC, ABTS, FRAP, DPPH, and ORAC assays. The profiling of phytochemicals was carried out by Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). For the first time, in vitro studies were performed by the interaction of extracted durian polyphenols with human serum proteins (HSP) such as human serum albumin (HSAlb), fibrinogen (HSFib) and globulin (HSGlo) as novel biomarkers of coronary artery disease (CAD). The fluorescence measurements of the resulting intensity and calculated binding properties of the interaction of polyphenols with proteins showed that the most reactive was Monthong durian cultivar. This study suggests that durian cultivars have relatively strong antioxidant, binding, and health potentials and could be a significant source of natural antioxidants used in daily fresh consumption and for functional foods.

  • Proteolysis of whey protein isolates in nanoemulsion systems: impact of nanoemulsification and additional synthetic emulsifiers
    • Patrycja Szumała
    • Aneta Pacyna-Kuchta
    • Andrzej Wasik
    2021 FOOD CHEMISTRY

    Nanoemulsions are currently of interest in the functional food sector because their small droplet size (100–500 nm) provides a number of potential advantages over conventional emulsions. This study concerned the behavior of nanoemulsions stabilized with whey proteins and two synthetic emulsifiers (Tween 80 and Croduret), and exposed to conditions simulating the human upper gastrointestinal tract. In particular, the effect of synthetic emulsifiers (food additives) on the interfacial composition and digestion rate of milk proteins at the interface of nanoemulsions was determined. The results indicate that the protein was partially co-absorbed with only one synthetic emulsifier (Croduret) at the interface, which made protein more resistant to digestion in the nano-emulsion system. This suggests that the degree of protein digestion can be controlled by appropriate selection of synthetic emulsifiers and presenting the protein in nanoemulsion system.

  • Prototype design and development of low-load-roof photovoltaic modules for applications in on-grid systems
    • Piotr Jerzy Grygiel
    • Jan Tarłowski
    • Marta Prześniak-Welenc
    • Marcin Łapiński
    • Jacek Łubiński
    • Aleksandra Mielewczyk-Gryń
    • Krzysztof Mik
    • Michał Bartmański
    • Daniel Pelczarski
    • Maciej Kwiatek
    2021 Pełny tekst SOLAR ENERGY MATERIALS AND SOLAR CELLS

    Four prototypes of lightweight photovoltaic modules for applications in on-grid systems have been designed, developed, manufactured and tested for compliance with relevant IEC standards. Selected, commercially available materials characterized by thermogravimetry, differential scanning calorimetry, dilatometry, scanning electron microscopy and nanoindentation technique were used in frameless, adhesively-bonded sandwich-structures carrying the interdigitated back contact solar cells. With dedicated manufacturing processes the prototype-dependent weight between 3.37 and 3.77 kg/m2, the STC-maximum power in the range of 221–239 Wp together with power conversion efficiencies of 19.98–20.71% were obtained. Millimetre-sized texture improved module's performance for steeper solar incidence angles. The self-cleaning capability of modules was enhanced by a hydrophobic material utilized in front linings. The structure of the prototypes helps to build non-intrusive installations on low-load capacity roofs, even in large-scale lightweight buildings.

  • Przed modernizmem - style w gdyńskiej architekturze lat dwudziestych
    • Maria Sołtysik
    2021

    Zarówno w historiografii architektury polskiej jak i europejskiej lata dwudzieste XX wieku omawiane są głównie w kontekście rodzącego się modernizmu. Nic w tym zresztą nie ma dziwnego, bo to właśnie ten nurt wyznaczał nowe trendy i w przyszłości decydować miał o dziejach architektury w całym stuleciu. Odchodziła w przeszłość trwająca od połowy XIX wieku epoka historyzmu, a zaczynała się epoka nowa, modernistyczna. Tak więc oblicze stylowe lat dwudziestych było niezwykle różnorodne i obok tendencji modernistycznych obecne były tendencje osadzone głęboko w tradycji historycznej. Celem rozdziału monograficznego było przedstawienie panoramy stylowej Gdyni w okresie historyzmu, a więc w okresie poprzedzającym rewolucyjne zmiany jakie w architekturze miasta wprowadziła modernistyczna awangarda. Publikację otwierają rozważania o przedmodernistycznej architekturze Polski i Gdyni na tle międzynarodowym. Następnie tematem są gdyńskie realizacje stylu dworkowego i zakopiańskiego. Kolejny podrozdział dotyczy specyficznej odmiany formacji narodowej, jaką był tzw. styl swojski. Rozdział kończy przedstawienie licznych realizacji klasycyzmu akademickiego w Gdyni.

  • Przedsiębiorczość cyfrowa oparta na blogu – wiwisekcja
    • Julita Wasilczuk
    2021

    Postęp technologiczny oraz powszechny dostęp do sieci przyczynił się do powstania różnych form przedsiębiorczości, które nie zawsze można zamknąć w ramy dotychczasowych teorii. Możliwość zarobkowania dzięki cyfrowemu połączeniu ze społecznością zgromadzoną wokół dziennika internetowego – bloga, przyczynia się do zwiększania liczby blogerów, jednak nie wszyscy blogerzy są w stanie wygenerować ze swojej działalności zyski. Wykorzystując metodę netnografii opisano zachowania przedsiębiorcze blogerów, opisując proces przedsiębiorczy oparty na prowadzeniu dziennika internetowego – bloga. Wskazano, że sam proces tworzenia bloga ma wiele wspólnego z procesem przedsiębiorczym, wykazano także analogie tego procesu do lean start-upu.

  • Przegląd metod szybkiego prototypowania algorytmów uczenia maszynowego w FPGA
    • Robert Smyk
    • Paweł Kowalski
    2021 Pełny tekst Poznan University of Technology Academic Journals. Electrical Engineering

    W artykule opisano możliwe do wykorzystania otwarte narzędzia wspomagające szybkie prototypowanie algorytmów uczenia maszynowego (ML) i sztucznej inteligencji (AI) przy użyciu współczesnych platform FPGA. Przedstawiono przykład szybkiej ścieżki przy realizacji toru wideo wraz z implementacją przykładowego algorytmu prze-twarzania w trybie na żywo.

  • Przegląd rozwiązań systemowych łączników balkonowych
    • Maciej Solarczyk
    • Paweł Piotrkowski
    • Maciej Niedostatkiewicz
    2021 Pełny tekst Przegląd Budowlany

    W artykule zamieszczono przegląd aktualnie stosowanych na rynku łączników balkonowych, przeprowadzono szczegółową analizę ich zalet i wad, ze szczególnym uwzględnieniem aspektów wytrzymałościowych oraz izolacyjności termicznej

  • Przemiany metaboliczne in vitro niesymetrycznych bisakrydyn w układach bezkomórkowych i w komórkach nowotworowych oraz określenie wpływu tych pochodnych na aktywność enzymów metabolizujących leki
    • Anna Mieszkowska
    2021 Pełny tekst

    Przedmiotem badań prowadzonych w ramach niniejszej pracy doktorskiej są cztery niesymetryczne bisakrydyny: C-2028, C-2041, C-2045 i C-2053, wykazujące wysoką aktywność cytotoksyczną [Konopa i in. 2019]. Otrzymane wyniki wskazały, że każdy z pierścieni (imidazoakrydonu i 1-nitroakrydyny) obecny w strukturze badanych związków odgrywa inną rolę w wykazywanych przez nie właściwościach fizykochemicznych i biologicznych. Właściwości te różnią się też od tych wykazywanych przez ich monomeryczne analogi. Wszystkie związki podlegają w pewnym stopniu przemianom metabolicznym I fazy wobec enzymów mikrosomalnych i izoenzymów P450 2C19 i 3A4. Prowadzą one do czterech grup metabolitów. Związki C-2028, C-2045 i C-2053 metabolizują również wobec FMO1 do N-tlenku. Tylko związek C-2045 (analog z grupą hydroksylową w pierścieniu imidazoakrydonu) ulega glukuronidacji wobec izoenzymów UGT1A1, 1A9 i 1A10. Metabolit ten otrzymano również w komórkach HCT-116-1A10, jak i HT-29. Pozostałe związki nie wykazały zdolności do przemian metabolicznych w tych liniach komórkowych, a więc, aby wykazać efekt terapeutyczny nie wymagają uprzedniej biochemicznej aktywacji. Wszystkie cztery związki hamowały aktywność P4503A4 oraz modulowały aktywność UGT1A1 i UGT2B7. Otrzymane wyniki wskazują również, że w zależności od różnic ekspresji izoenzymów UGT w danej tkance, badane związki mogą powodować odmienny efekt.

  • Przemiany przestrzenne w obrębie średniowiecznego założenia klasztornego karmelitów przy kościele św. Józefa w Gdańsku w świetle wykopalisk archeologicznych
    • Monika Kasprzak
    • Piotr Samól
    2021 Archeologia Gdańska

    Artykuł dotyczy prac archeologicznych prowadzonych w latach 2017-2019 oraz opracowań architektonicznych wykonywanych w latach 2018-2019. Wprowadza nowe ustalenia na temat przekształceń zespołu karmelickiego w późnym średniowieczu tj. dla okresu po 1464 - ok. 1520. Ponadto wskazuje na możliwe usytuowanie zabudowań szpitala św. Jerzego (przed 1335 - przed 1464).

  • PRZE-MIESZKIWANIE [w ramach:] PUSTKA, wystawa zbiorowa
    • Agnieszka Kurkowska
    2021

    „Prze-mieszkiwanie” to praca ukazująca podstawową potrzebę i konieczność zapewnienia sobie przez wszelkie organizmy żywe, w tym w szczególności przez człowieka, bezpiecznej kryjówki w obliczu dojmującego poczucia postpandemicznej pustki i przymusowej izolacji, ale też kulturowego wykorzenienia. Metaforyczne wyobrażenia archetypicznej formy schronienia pokazuje jej adaptowalność do różnorodnych uwarunkowań, gdzie kontekst stanowi zadanie problemowe, na które odpowiedzią jest konkretna forma, spasowana do swojego otoczenia i odpowiadająca zastanej sytuacji przestrzennej.

  • Przemysł, zanieczyszczenie i klimat
    • Bartłomiej Cieślik
    2021

    W wielu doniesieniach literaturowych można znaleźć informacji o stale rosnącej średniej temperaturze na ziemi. Wiele gałęzi przemysłu bezpośrednio wpływa na klimat. Niektóre z nich, takie jak przemysł węglowy, paliwowy czy energetyczny, uznawane są za szczególnie problematyczne. Większość ludzi nie zdaje sobie jednak sprawy jak bardzo pozostałe gałęzie przemysłu mogą wpływać na zanieczyszczenie środowiska. Niektóre z nich pośrednio, mogą oddziaływać na jakość różnych elementów środowiska. To my, konsumenci mamy największy wpływ na to co wytwarza dla nas przemysł. Dlatego edukacja i uświadamianie społeczeństwa powinno znaleźć się na liście TOP 10 działań mających wpłynąć na poprawę stanu środowiska.

  • Przestrzenie nieoczywiste
    • Agnieszka Kurkowska
    2021

    Projektujemy naszą przyszłość poruszając się w przestrzeniach nieoczywistych, nienazwanych, niezmierzonych. Przekraczamy granice. Marzenia wypełniają sytuacje codzienne. Stąd czerpiemy energię do pokonywania trudności. Mierzenia się z wyzwaniami, szczególnie wobec spiętrzających się ograniczeń. Jak przywołać wyobrażenie sytuacji nienazwanych? Czy barwne plamy i linie opowiadają realne historie z przestrzeni nieoczywistych? Zapraszam do konfrontacji z moją wizją.

  • Przewodnik Architektoniczny=Architectural Guide=Architekturführer. Gdynia
    • Justyna Borucka
    • Harald Gatermann
    2021

    Gdynia is a unique city that is particularly interesting for architects due to its homogeneous architecture. The city, based on the structure of an earlier fishing village, was entirely designed and built from scratch in the interwar period, as was the case later for cities such as Brasilia and Chandigarh. Today, Gdynia is a modern port town that forms the Tri-City metropolitan area together with Gdańsk, the city of amber, and Sopot, an internationally popular seaside resort. Gdańsk was completely destroyed during the Second World War and was subsequently rebuilt as Polish Gdańsk; it serves as a bright example of reconstruction in Poland. Sopot is considered a museum of architecture from the turn of the twentieth century, full of Art Nouveau villas and nostalgic baths. Gdynia, in turn, is a city of avant-garde modernism from the 1920s and 1930s. Thus, the Tri-City combines three great trends of the past century which are the subject of intense debates among architects. This architectural guide is an excerpt from a broader publication, Architekturfuehrer Danzig: Gdańsk Sopot Gdynia, concerning the Tri-City metropolitan region. It presents the modern and unique city of Gdynia by way of eight city walks. The two authors go on a tour around Gdynia, presenting around 80 buildings and projects. The architectural descriptions, accompanied by an extensive collection of plans and photographs, offer ideal guidance for those who wish to get to know the city.

  • Przyrządy do docierania powierzchni płaskich i płasko-równoległych docierakami aktywizowanymi w sposób swobodny i wymuszony
    • Adam Barylski
    2021

    Przedstawiono konstrukcje przyrządów do docierania powierzchni płaskich i płasko-równoległych elementów o niewielkich wymiarach gabarytowych. Analizowano wersje oprzyrządowania w aspekcie łatwości obsługi przy docieraniu dwutarczowym z obiegowym układem kinematycznym i przy użyciu dawkowanej okresowo pasty ściernej. Opracowano też koncepcję zmechanizowanej aktywizacji wymuszonej powierzchni roboczej tarczy docierającej mikroziarnami ściernymi

  • PTD4 Peptide Increases Neural Viability in an In Vitro Model of Acute Ischemic Stroke
    • Jarosław Mazuryk
    • Izabela Puchalska
    • Kamil Koziński
    • Magdalena J. Ślusarz
    • Jarosław Ruczyński
    • Piotr Rekowski
    • Piotr Rogujski
    • Rafał Płatek
    • Marta Barbara Wiśniewska
    • Arkadiusz Piotrowski
    • Łukasz Janus
    • Piotr M. Skowron
    • Michał Pikuła
    • Paweł Sachadyn
    • Sylwia Rodziewicz-Motowidło
    • Artur Czupryn
    • Piotr Mucha
    2021 Pełny tekst INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    Ischemic stroke is a disturbance in cerebral blood flow caused by brain tissue ischemia and hypoxia. We optimized a multifactorial in vitro model of acute ischemic stroke using rat primary neural cultures. This model was exploited to investigate the pro-viable activity of cell-penetrating peptides: arginine-rich Tat(49–57)-NH2 (R49KKRRQRRR57-amide) and its less basic analogue, PTD4 (Y47ARAAARQARA57-amide). Our model included glucose deprivation, oxidative stress, lactic acidosis, and excitotoxicity. Neurotoxicity of these peptides was excluded below a concentration of 50 μm, and PTD4-induced pro-survival was more pronounced. Circular dichroism spectroscopy and molecular dynamics (MD) calculations proved potential contribution of the peptide conformational properties to neuroprotection: in MD, Tat(49–57)-NH2 adopted a random coil and polyproline type II helical structure, whereas PTD4 adopted a helical structure. In an aqueous environment, the peptides mostly adopted a random coil conformation (PTD4) or a polyproline type II helical (Tat(49–57)-NH2) structure. In 30% TFE, PTD4 showed a tendency to adopt a helical structure. Overall, the pro-viable activity of PTD4 was not correlated with the arginine content but rather with the peptide’s ability to adopt a helical structure in the membrane-mimicking environment, which enhances its cell membrane permeability. PTD4 may act as a leader sequence in novel drugs for the treatment of acute ischemic stroke.

  • PTR-MS and electronic nose application for volatile fraction analysis of cigar tobacco
    • Paweł Jacek Hać
    • Julia Dobosz
    • Łukasz Kołodziejski
    • Bartłomiej Cieślik
    • Piotr Konieczka
    2021

    Cigar consumers attach great importance to the quality of these products. At the same time, cigars are often expensive, so destructive analytical methods of quality control are not being desired. However, it has been found that there are many volatile organic compounds in their headspace. Because of that, proton transfer reaction–mass spectrometry and electronic nose were used to analyse it. The obtained results were used to distinguish between cigars of different quality.

  • Public Perception of Digital Contact Tracing App and Implications for Technology Acceptance and Use Models
    • Adegboyega Ojo
    • Nina Rizun
    2021

    Governments are increasingly adopting digital contact tracing applications (DCT) as a key component of their response to the COVID-19 pandemic. However, governments are struggling to achieve widespread adoption of DCT necessary for obtaining the expected individual and public benefits associated with its use. Consequently, studies on DCT have focused on the barriers to DCT adoption in different contexts and possible ways of overcoming some of the public concerns regarding the technology. Given the global nature of this innovation, this study explores extant literature and the public perception of DCT expressed in public tweets from different regions of the world. Our findings reveal emergent factors associated with the diffusion and adoption of the technology and enable us to better account for the ambivalent nature of DCT and its public-health innovation context in technology adoption models such as UTAUT.

  • Pulsed UV-irradiated Graphene Sensors for Ethanol Detection at Room Temperature
    • Katarzyna Drozdowska
    • Adil Rehman
    • Pavlo Sai
    • Bartłomiej Stonio
    • Aleksandra Krajewska
    • Grzegorz Cywiński
    • Maciej Haras
    • S. Rumyantsev
    • Janusz Smulko
    • Andrzej Kwiatkowski
    2021 Pełny tekst

    A graphene-based gas sensor fabricated in a FET (GFET) configuration and its sensitivity towards ethanol and methane is reported. Detection of ethanol at the level of 100 ppm was observed under pulsed UV irradiation and after cleaning by UV light in the N2 ambient. Reduction of the frequency of UV irradiation pulses resulted in increased changes in sensor resistance in the presence of ethanol. Improved sensing behavior was ascribed to more effective diffusion and adsorption processes at the graphene surface during low-frequency UV light pulses. Additionally, modulation of charge carrier density allowed more pronounced sensor responses at higher gate voltages (~30 V). GFET was insensitive to methane (200 ppm) at room temperature, regardless of irradiation frequency used, suggesting the potential application of selective gas sensing capability of graphene-based devices.

  • Pulse-Width Modulation of Power Electronic DC–AC Converter
    • Atif Iqbal
    • Arkadiusz Lewicki
    • Marcin Morawiec
    2021

    The Second Edition of High Performance Control of AC Drives with Matlab®/Simulink delivers an updated and thorough overview of topics central to the understanding of AC motor drive systems. The book includes new material on medium voltage drives, covering state-of-the-art technologies and challenges in the industrial drive system, as well as their components, and control, current source inverter-based drives, PWM techniques for multilevel inverters, and low switching frequency modulation for voltage source inverters.

  • Pulse-Width Modulation Template for Five-Level Switch-Clamped H-Bridge-Based Cascaded Multilevel Inverter
    • Charles Ikechukwu Odeh
    • Dmytro Kondratenko
    • Arkadiusz Lewicki
    • Marcin Morawiec
    • Andrzej Jąderko
    • Janusz Baran
    2021 Pełny tekst ENERGIES

    This article presents a carrier-based pulse-width modulation (PWM) template for a 5-level, H bridge-based cascaded multilevel inverter (MLI). The developed control concept generates adequate modulation template for this inverter topology wherein a sinusoidal modulating waveform is modified to fit in a single triangular carrier signal range. With this modulation approach, classical multiplicity and synchronization of the triangular carrier signals criterion for the extension of sinusoidal pulse-width modulation, SPWM, to several cascaded 5-level, H-bridge-based MLI topology are removed. The proposed template can be used on the inverter configuration of any level with no further control modification. Nearly even distribution of switching pulses and equalized individual cascaded cell output power were achieved with the proposed modulation scheme. Three 5-level, H-bridge-based MLI units were cascaded for 1-phase, 13-level inverter operation; simulation and experimental results are adequately presented.

  • Pyrolysis of Pruning Residues from Various Types of Orchards and Pretreatment for Energetic Use of Biochar
    • Paweł Kazimierski
    • Paulina Hercel
    • Tomasz Suchocki
    • Jakub Smoliński
    • Agnieszka Pladzyk
    • Dariusz Kardaś
    • Justyna Łuczak
    • Katarzyna Januszewicz
    2021 Pełny tekst Materials

    The routine pruning and cutting of fruit trees provides a considerable amount of biowaste each year. This lignocellulosic biomass, mainly in the form of branches, trunks, rootstocks, and leaves, is a potential high-quality fuel, yet often is treated as waste. The results of a feasibility study on biochar production by pyrolysis of residues from orchard pruning were presented. Three types of biomass waste were selected as raw materials and were obtained from the most common fruit trees in Poland: apple (AP), pear (PR), and plum (PL) tree prunings. Two heating rates and three final pyrolysis temperatures were applied. For the slow (SP) and fast pyrolysis (FP) processes, the heating rates were 15 °C/min and 100 °C/min, respectively. The samples were heated from 25 °C up to 400, 500, and 600 °C. Chemical analyses of the raw materials were conducted, and the pyrolysis product yields were determined. A significant rise of higher heating value (HHV) was observed for the solid pyrolysis products, from approximately 23.45 MJ/kg for raw materials up to approximately 29.52 MJ/kg for pyrolysis products at 400 °C, and 30.53 MJ/kg for pyrolysis products at 600 °C. Higher carbon content was observed for materials obtained by fast pyrolysis conducted at higher temperatures

  • QUALITY GAPS IN HIGHER EDUCATION FROM THE PERSPECTIVE OF STUDENTS
    • Piotr Grudowski
    • Katarzyna, Szczepańska
    2021 Pełny tekst Foundations of Management

    The presented research work relates to the category of quality in higher education. This article aims to present the determinants of the quality of education in the context of international standards. The background of the considerations is the Bologna Declaration and the European Higher Education Area. The results of the research carried out with the use of the nominal group method and the data analysis carried out based on the SERVQUAL model for education revealed groups of quality determi-nants that are not included in the standards of internal quality assurance. It has been found that the prin-ciple of autonomy of universities in the European Higher Education Area is a sufficient basis to include the determinants of the quality of education identified by internal stakeholders of a given university in the internal quality of education assurance system.

  • Quality of Satellite Communication in Selected Mobile Android Smartphones
    • Przemysław Falkowski-Gilski
    2021 Pełny tekst Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska

    Today, thanks to mobile devices, satellite communication is available to anyone and everywhere. Gaining information on one’s position using GNSS (Global Navigation Satellite Systems), particularly in unknown urban environments, had become an everyday activity. With the widespread of mobile devices, particularly smartphones, each person can obtain information considering his or her location anytime and everywhere. This paper is focused on a study, considering the quality of satellite communication in case of selected mobile terminals. It describes a measurement campaign carried out in varying urban environments, including a set of Android-powered smartphones coming from different manufacturers. Based on this, respective conclusions and remarks are given, which can aid consumers as well as device manufacturers and application developers.

  • Quantitative fluorescent determination of DNA – Ochratoxin a interactions supported by nitrogen-vacancy rich nanodiamonds
    • Wioleta Białobrzeska
    • Maciej Głowacki
    • Monika Janik
    • Mateusz Ficek
    • Krzysztof Pyrchla
    • Sawczak Mirosław
    • Robert Bogdanowicz
    • Natalia Malinowska
    • Sabina Żołędowska
    • Dawid Nidzworski
    2021 Pełny tekst JOURNAL OF MOLECULAR LIQUIDS

    Ochratoxin A (OTA) is a hazardous contaminant of a large variety of plant and animal originated food. Herein, we report an interaction of OTA with calf thymus DNA (ct DNA) on the nanodiamond surface. We employed multispectroscopic techniques to elucidate the binding mechanism of OTA with ct DNA. The fluorescence and UV–Vis spectroscopy results show that OTA binds to ds ct DNA and forms complexes. We obtained the binding constants of OTA and ct DNA using fluorescence quenching and UV–Vis spectroscopy. The binding constant (Kb) for the interaction of OTA with ct DNA was determined using spectroscopic methods and was determined as 3.27 × 105 M−1 (UV–Vis) and 8.12 × 105 M−1 (fluorescence) for nanodiamond in green tea beverage OTA. Performed analyses directly indicate that OTA can interact with calf thymus DNA in a groove-binding mode as proved by the hyperchromic effect of the absorption spectra. This study of OTA–ct DNA interaction may provide novel insights into the toxicological effect of the mycotoxins.

  • Quantitative Risk Assessment in Construction Disputes Based on Machine Learning Tools
    • Hubert Anysz
    • Magdalena Apollo
    • Beata Grzyl
    2021 Pełny tekst Symmetry-Basel

    A high monetary value of the construction projects is one of the reasons of frequent disputes between a general contractor (GC) and a client. A construction site is a unique, one-time, and single-product factory with many parties involved and dependent on each other. The organizational dependencies and their complexity make any fault or mistake propagate and influence the final result (delays, cost overruns). The constant will of the parties involved results in completing a construction object. The cost increase, over the expected level, may cause settlements between parties difficult and lead to disputes that often finish in a court. Such decision of taking a client to a court may influence the future relations with a client, the trademark of the GC, as well as, its finance. To ascertain the correctness of the decision of this kind, the machine learning tools as decision trees (DT) and artificial neural networks (ANN) are applied to predict the result of a dispute. The dataset of about 10 projects completed by an undisclosed contractor is analyzed. Based on that, a much bigger database is simulated for automated classifications onto the following two classes: a dispute won or lost. The accuracy of over 93% is achieved, and the reasoning based on results from DT and ANN is presented and analyzed. The novelty of the article is the usage of in-company data as the independent variables what makes the model tailored for a specific GC. Secondly, the calculation of the risk of wrong decisions based on machine learning tools predictions is introduced and discussed

  • Quantum and carbon dots conjugated molecularly imprinted polymers as advanced nanomaterials for selective recognition of analytes in environmental, food and biomedical applications
    • Monika Sobiech
    • Piotr Luliński
    • Piotr Paweł Wieczorek
    • Mariusz Marć
    2021 TRAC-TRENDS IN ANALYTICAL CHEMISTRY

    Samples with complex matrix analyzed during explanation of pathogenesis of various diseases and food or environmental monitoring request advanced analytical and instrumental devices. Among the materials used for described purposes, quantum (QDs) or carbon dots (CDs) layered by molecularly imprinted polymer (MIP) shells have gained widespread attention. Unique optical and physicochemical properties of QDs/CDs together with high MIPs selectivity make the QD/CD-MIP conjugates capable of adsorbing specific target molecules e such a binding event is then transduced as the optical signal of the response by the QDs/CDs. This review includes brief introduction on principles of imprinting process, QD/CD properties and QD/CD-MIP preparation techniques. Then, recent advancement of QD/CD-MIP in bioanalysis including environmental, biological and food samples investigations are summarized and emphasized. Finally, current limits of QD/CD-MIPs are defined and prospects are outlined to intensify the capability of QD/CD-MIP in future bioanalytical procedures

  • Quantum Dots as a Good Carriers of Unsymmetrical Bisacridines for Modulating Cellular Uptake and the Biological Response in Lung and Colon Cancer Cells
    • Joanna Pilch
    • Patrycja Kowalik
    • Piotr Bujak
    • Anna M. Nowicka
    • Ewa Augustin
    2021 Pełny tekst Nanomaterials

    Nanotechnology-based drug delivery provides a promising area for improving the efficacy of cancer treatments. Therefore, we investigate the potential of using quantum dots (QDs) as drug carriers for antitumor unsymmetrical bisacridine derivatives (UAs) to cancer cells. We examine the influence of QD–UA hybrids on the cellular uptake, internalization (Confocal Laser Scanning Microscope), and the biological response (flow cytometry and light microscopy) in lung H460 and colon HCT116 cancer cells. We show the time- dependent cellular uptake of QD–UA hybrids, which were more efficiently retained inside the cells compared to UAs alone, especially in H460 cells, which could be due to multiple endocytosis pathways. In contrast, in HCT116 cells, the hybrids were taken up only by one endocytosis mechanism. Both UAs and their hybrids induced apoptosis in H460 and HCT116 cells (to a greater extent in H460). Cells which did not die underwent senescence more efficiently following QDs–UAs treatment, compared to UAs alone. Cellular senescence was not observed in HCT116 cells following treatment with both UAs and their hybrids. Importantly, QDgreen/red themselves did not provoke toxic responses in cancer or normal cells. In conclusion, QDs are good candidates for targeted UA delivery carriers to cancer cells while protecting normal cells from toxic drug activities.

  • Quantum randomness protected against detection loophole attacks
    • Piotr Mironowicz
    • Gustavo Cañas
    • Jaime Cariñe
    • Esteban S. Gómez
    • Johanna F. Barra
    • Adán Cabello
    • Guilherme B. Xavier
    • Gustavo Lima
    • Marcin Pawłowski
    2021 Quantum Information Processing

    Device and semi-device-independent private quantum randomness generators are crucial for applications requiring private randomness. However, they are vulnerable to detection inefficiency attacks and this limits severely their usage for practical purposes. Here, we present a method for protecting semi-device-independent private quantum randomness generators in prepare-and-measure scenarios against detection inefficiency attacks. The key idea is the introduction of a blocking device that adds failures in the communication between the preparation and measurement devices. We prove that, for any detection efficiency, there is a blocking rate that provides protection against these attacks. We experimentally demonstrate the generation of private randomness using weak coherent states and standard avalanche photo-detectors.

  • QUASI-DISTRIBUTED NETWORK OF LOW-COHERENCE FIBER-OPTIC FABRY-PÉROT SENSORS WITH CAVITY LENGTH-BASED ADDRESSING
    • Katarzyna Karpienko
    • Marcin Marzejon
    • Adam Mazikowski
    • Jerzy Pluciński
    2021 Pełny tekst Metrology and Measurement Systems

    Distributed measurement often relies on sensor networks. In this paper, we present the construction of low coherent fiber-optic Fabry-Pérot sensors connected into a quasi-distributed network. We discuss the mechanism of spectrum modulation in this type of sensor and the constraints of assembly of such sensors in the network. Particular attention was paid to separate the signals from individual sensors, which can be achieved by cavity length-based addressing. We designed and built a laboratory model of a temperature sensors network. The employed sensors are lowcoherence Fabry-Pérot interferometric sensors in fiber-optics configuration. The extrinsic sensor cavity utilizes the thermal expansion of ceramics, and the sensors are addressed by the different lengths of the cavities. The obtained test results show that the signal components from each sensor can be successfully separated, and the number of sensors could be expanded depending on the FWHM of the light source

  • Quasistatic and fatigue behavior of an AISI H13 steel obtained by additive manufacturing and conventional method
    • José F. Garcias
    • Rui F. Martins
    • Ricardo Branco
    • Zbigniew Marciniak
    • Wojciech Macek
    • Cândida Pereira
    • Cyril Santos
    2021 Pełny tekst FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES

    This work aims to compare the mechanical behavior of an AISI H13 steel obtained by additive manufacturing with that obtained by conventional manufacturing methods. The average values of the ultimate tensile strength (UTS) and ductility obtained for the specimens produced by the conventional method were equal to 658 MPa and 18%, respectively, which compares with 503 MPa and 0.75% registered for the selective laser melting (SLM) specimens. Inversely, the average hardness value determined for the SLM specimens was higher, 450 HV, than the observed for the conventional, 200 HV. In addition, the maximum applied stress corresponding to a fatigue limit's endurance of 2 x 106 cycles was equal to 340 and 85 MPa for conventional and SLM specimens, respectively. Therefore, from a fatigue design point of view, it was possible to infer that σmax/UTS = 0.17 for the SLM specimens tested. Porosity and lack of fusion influenced the static and the fatigue strength negatively in the SLM specimens.

  • Quest for the Molecular Basis of Improved Selective Toxicity of All-Trans Isomers of Aromatic Heptaene Macrolide Antifungal Antibiotics
    • Julia Borzyszkowska-Bukowska
    • Justyna Górska
    • Paweł Szczeblewski
    • Tomasz Laskowski
    • Iwona Gabriel
    • Jakub Jurasz
    • Katarzyna Kozłowska-Tylingo
    • Piotr Szweda
    • Sławomir Milewski
    2021 Pełny tekst INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    Three aromatic heptaene macrolide antifungal antibiotics, Candicidin D, Partricin A (Gedamycin) and Partricin B (Vacidin) were subjected to controlled cis-trans to all trans photochemical isomerization. The obtained all-trans isomers demonstrated substantially improved in vitro selective toxicity in the Candida albicans cells: human erythrocytes model. This effect was mainly due to the diminished hemotoxicity. The molecular modeling studies on interactions between original antibiotics and their photoisomers with ergosterol and cholesterol revealed some difference in free energy profiles of formation of binary antibiotic/sterol complexes in respective membrane environments. Moreover, different geometries of heptaene: sterol complexes and variations in polyene macrolide molecule alignment in cholesterol- and ergosterol-containing membranes were found. None of these effects are of the crucial importance for the observed improvement of selective toxicity of aromatic heptaene antifungals but each seems to provide a partial contribution.

  • Racjonalność (w) ekonomii. Mapa problemu
    • Andrzej Lisak
    2021

    Praca analizuje racjonalność zjawisk ekonomicznych w perspektywie całości funkcjonowania systemu społecznego, racjonalność podmiotu (homo oeconomicus), racjonalność samych zjawisk ekonomicznych oraz racjonalność ekonomi jako nauki. Stwarza to szerszą filozoficzną perspektywę rozumienia sensu zjawisk ekonomicznych w ludzkim życiu jak i lepsze zrozumienie problemu racjonalności.

  • Radar and Sonar Imaging and Processing (2nd Edition)
    • Andrzej Stateczny
    • Witold Kazimierski
    • Krzysztof Kulpa
    2021 Pełny tekst Remote Sensing

    The 14 papers (from 29 submitted) published in the Special Issue “Radar and Sonar Imaging Processing (2nd Edition)” highlight a variety of topics related to remote sensing with radar and sonar sensors. The sequence of articles included in the SI deal with a broad profile of aspects of the use of radar and sonar images in line with the latest scientific trends, in which the latest developments in science, including artificial intelligence, were used.

  • Radiative lifetime of a BODIPY dye as calculated by TDDFT and EOM-CCSD methods: solvent and vibronic effects
    • Rengel Cane Sia
    • Ruben Arturo Arellano-Reyes
    • Tia E. Keyes
    • Julien Guthmuller
    2021 Pełny tekst PHYSICAL CHEMISTRY CHEMICAL PHYSICS

    The radiative emission lifetime and associated S1 excited state properties of a BODIPY dye are investigated with TDDFT and EOM-CCSD calculations. The effects of a solvent are described with the polarizable continuum model using the linear response (LR) approach as well as state-specific methods. The Franck–Condon (FC), Herzberg–Teller (HT) and Duschinsky vibronic effects are evaluated for the absorption and emission spectra, and for the radiative lifetime. The transition energies, spectra shapes and radiative lifetime are assessed with respect to experimental results. It is found that the TDDFT transition energies are overestimated by about 0.4–0.5 eV, whereas EOM-CCSD improves the vertical emission energy by about 0.1 eV in comparison to TDDFT. The solvatochromic and Stokes shifts are better reproduced by the state-specific solvation methods, which show that these methods are more suited than the LR model to describe the solvent effects on the BODIPY dye. The vibronic effects lead to an increase of the radiative lifetime of about 0.4 to 1.0 ns depending on the theoretical approach, which highlights the importance of such effects. Moreover, the HT effects are negligible on both the spectra and lifetime, which demonstrates that the FC approximation is accurate for the BODIPY dye. Finally, the comparison with experimental data shows that the radiative lifetimes predicted by EOM-CCSD and TDDFT have comparable accuracy.

  • Rapid determination of multiple aminoglycoside antibiotics in veterinary formulations by ion-pair chromatography coupled with evaporative light scattering detection
    • Marta Glinka
    • Andrzej Wasik
    2021 Pełny tekst MICROCHEMICAL JOURNAL

    A fast and simple method for simultaneous determination of eight aminoglycoside antibiotics using ion-pairing liquid chromatography (IPLC) coupled with evaporative light scattering detection (ELSD) has been developed and validated. Separation of amikacin, apramycin, gentamicin (as a sum of gentamicin C1, C2 and C1A), kanamycin A, neomycin B, paromomycin, streptomycin and tobramycin was achieved using C18 column with H2O and MeOH/acetone, both with addition of nonafluoropentanoic acid. Limits of detection ranged between 1.2 μg/mL and 2.8 μg/mL. The total analysis time was 9.5 min. The developed method showed the suitability for the routine quality control of veterinary drugs (drops, powders and paraffin-based suspensions).

  • Rapid development of the photoresponse and oxygen evolution of TiO2 nanotubes sputtered with Cr thin films realized via laser annealing
    • Łukasz Haryński
    • Jakub Karczewski
    • Jacek Ryl
    • Katarzyna Grochowska
    • Katarzyna Siuzdak
    2021 JOURNAL OF ALLOYS AND COMPOUNDS

    Recently, earth abundant transition metal oxides have gained particular attention as potential catalyst candidates due to their availability and low-cost comparing to substrates containing precious Pt or Au species. Herein, we present characterization of morphology, structure and electrochemical properties of pulsed 532 nm laser treated TiO2 nanotubes (NT) sputtered by the thin film of chromium. Scanning electron microscopy enables verification of the diameter and length of titania while Raman and X-ray photoelectron spectroscopies were used to evaluate crystalline phase and the oxidation state of elements, respectively. The recorded polarization curves clearly indicate that the optimized laser-treatment enhances activity towards oxygen evolution reaction (OER) of the TiO2 NT decorated with very small amount of Cr species. The analysis of Mott-Schottky plot shows significant increment in donor density (Nd) for the laser irradiated sample comparing to the one before annealing and pristine titania resulting from the effective manipulation of the electrode/electrolyte interface. Moreover, the impact of the processing parameters including energy fluence of laser beam and the thickness of sputtered Cr layer on the current density was evaluated by the electrochemical measurements performed under vis and UV–vis light. The results show promising application of direct interaction of laser beam with the surface of material exhibiting initially both poor OER activity and visible light response.

  • Rapid Multi-Criterial Antenna Optimization by Means of Pareto Front Triangulation and Interpolative Design Predictors
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    2021 Pełny tekst IEEE Access

    Modern antenna systems are designed to meet stringent performance requirements pertinent to both their electrical and field properties. The objectives typically stay in conflict with each other. As the simultaneous improvement of all performance parameters is rarely possible, compromise solutions have to be sought. The most comprehensive information about available design trade-offs can be obtained through multi-objective optimization (MO), typically in the form of a Pareto set. Notwithstanding, MO is a numerically challenging task, in a large part due to high CPU cost of evaluating the antenna properties, normally carried out through full-wave electromagnetic (EM) analysis. Surrogate-assisted procedures can mitigate the cost issue to a certain extent but construction of reliable metamodels is hindered by the curse of dimensionality, and often highly nonlinear antenna characteristics. This work proposes an alternative approach to MO of antennas. The major contribution of our work consists in establishing a deterministic machine learning procedure, which involves sequential generation of Pareto-optimal designs based on the knowledge gathered so far in the process (specifically, by triangulation of the already obtained Pareto set), and local surrogate-assisted refinement procedures. Our methodology allows for rendering uniformly-distributed Pareto designs at the cost of a few hundreds of antenna EM simulations, as demonstrated by means of three verification case studies. Benchmarking against state-of-the-art MO techniques is provided as well.

  • Reactivity of bulky aminophosphanes towards small molecules: Activation of dihydrogen and carbon dioxide by aminophosphane/borane frustrated Lewis pairs
    • Magdalena Siedzielnik
    • Kinga Kaniewska-Laskowska
    • Natalia Szynkiewicz
    • Jarosław Chojnacki
    • Rafał Grubba
    2021 POLYHEDRON

    A series of mono- and bisaminophosphanes with formulas R<sub>2</sub>NPR’R’’ and (R<sub>2</sub>N)<sub>2</sub>PR’ (R = iPr, Cy; R’ = Ph, Cy; R’’ = iPr) were characterized by X-ray analysis, NMR spectroscopy and computational methods. The common structural futures of these species are short and polarized PAN bonds, a pyramidal geometry at the P atom and an almost planar geometry at the N atoms. According to DFT calculations, these compounds are highly nucleophilic, with nucleophilic centers located on the N and P atoms. Except for species containing a PPh<sub>2</sub> moiety, the obtained aminophosphanes are air-stable and do not react with water. They form stable frustrated Lewis pairs with BPh3 or B(C6F5)3. Mono- and bisaminophosphanes in the presence of B(C6F5)3 activate dihydrogen and carbon dioxide at room temperature

  • Real-time isothermal DNA amplification monitoring in picoliter volumes using an optical fiber sensor
    • Monika Janik
    • Seyed Vahid Hamidi
    • Marcin Koba
    • Jonathan Perreault
    • Ryan Walsh
    • Wojtek J. Bock
    • Mateusz Śmietana
    2021 LAB ON A CHIP

    Rolling circle amplification (RCA) of DNA can be considered as a great alternative to the gold standard polymerase chain reaction (PCR), especially during this pandemic period, where rapid, sensitive, and reliable test results for hundreds of thousands of samples are required daily. This work presents the first research to date on direct, real-time and label-free isothermal DNA amplification monitoring using a microcavity in-line Mach–Zehnder interferometer (μIMZI) fabricated in an optical fiber. The solution based on μIMZI offers a great advantage over many other sensing concepts – making possible optical analysis in just picoliter sample volumes. The selectivity of the biosensor is determined by DNA primers immobilized on the microcavity's surface that act as selective biorecognition elements and trigger initiation of the DNA amplification process. In this study, we verified the sensing concept using circular DNA designed to target the H5N1 influenza virus. The developed biosensor exhibits an ultrahigh refractive index sensitivity reaching 14 000 nm per refractive index unit and a linear detection range between 9.4 aM and 94 pM of the target DNA sequence. Within a 30 min period, the amplification of as little as 9.4 aM DNA can be effectively detected, with a calculated limit of detection of as low as 0.2 aM DNA, suggesting that this methodology holds great promise in practical disease diagnosis applications in the future.

  • Real-time monitoring of volatiles and particles emitted from thermoplastic filaments during 3D printing
    • Wojciech Wojnowski
    2021

    Presentation on the use of instrumental analytical techniques for the assessment of emission of volatiles and particulates during fdm 3d printing.