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Repozytorium publikacji
Politechniki Gdańskiej

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  • Wytwarzanie, badania i analiza płyt pochodzących z odpadu celulozowego –case study
    • Patryk Puchowski
    • Marcin Szczepański
    2024 Builder

    Niniejszy artykuł zawiera opis procesu wytwarzania oraz badań płyt kompozytowych wykonanych z wykorzystaniem odpadu celulozowego. Ten nowo powstały materiał wyprodukowany został z odpadów papierowych w postaci zmielonych gazet w kilku wariantach składu o różnym udziale procentowym wsadu celulozowego. W celu określenia jego właściwości mechanicznych i fizycznych przeprowadzono dwa badania laboratoryjne. Z wykorzystaniem maszyny wytrzymałościowej zbadano zachowanie się materiału podczas próby rozciągania osiowego i na podstawie wyników obliczono moduł sprężystości. Z kolei poprzez dynamiczną analizę mechaniczną DMA (ang. Dynamic Mechanical Analysis) określone zostały właściwości lepkosprężyste materiału w zależności od zmiany temperatury. Otrzymane wyniki wraz z wynikami przyszłych badań pozwolą wypozycjonować badany materiał wśród podobnych rozwiązań płyt drewnopochodnych dostępnych na rynku. Na tej podstawie możliwe będzie określenie jego potencjalnej przydatności do zastosowania w przemyśle np. budowlanym.

  • Wytwarzanie i modyfikacja powierzchni porowatych struktur tytanowych przeznaczonych na implanty
    • Magda Rościszewska
    2024 Pełny tekst

    Celem pracy było wytworzenie stopu Ti-13Nb-13Zr z wykorzystaniem technologii selektywnego topienia laserowego (SLM) oraz jego biofunkcjonalizacja za pomocą utleniania mikrołukowego (MAO), a następnie określenie wpływu parametrów procesowych na właściwości otrzymanych materiałów pod kątem ich zastosowania na implanty. Oceniono wpływ napięcia, natężenia i czasu procesu MAO przeprowadzanego w elektrolicie zawierającym wapń i fosfor na charakterystykę warstw. Następnie zbadano wpływ bioaktywnych dodatków srebra i galu na charakterystykę otrzymanych warstw, oraz porównano właściwości uzyskanych warstw MAO w zależności od metody wytwarzania materiału referencyjnego. Metodyka badań obejmowała charakteryzację topografii powierzchni (SEM, AFM), składu chemicznego (EDS) i fazowego (XRD), pomiary kąta zwilżania (tensjometr optyczny), badania mechaniczne (nanoindentacja i test zarysowania), ocenę wstępnej bioaktywności (test immersji), badania uwalniania jonów (MP-AES), test żywotności komórek (MTT) oraz ocenę cytotoksyczności (zliczanie kolonii bakterii). Badania wykazały, że warstwy MAO, zawierające wapń i fosfor z dodatkiem srebra lub galu, wytworzone przy odpowiedniej kombinacji parametrów procesu zwiększają biozgodność oraz aktywność biologiczną implantu tytanowego, a charakterystyka materiałów wytworzonych SLM, w tym ich mikrostruktura, istotnie wpływa na właściwości warstw MAO.

  • Wyzwania współpracy z robotem jako członkiem zespołu
    • Beata Krawczyk-Bryłka
    • Krzysztof Nowicki
    2024 Pełny tekst Zeszyty Naukowe Uniwersytetu Ekonomicznego w Krakowie

    – Cel: Ocena, jakie są przekonania dotyczące współpracy z robotami w zespole, jakie są obawy i oczekiwania związane z „zatrudnianiem” robotów. – Metodyka badań: Badania ilościowe zrealizowane z zastosowaniem kwestionariusza ankiety w grupie 593 specjalistów IT. – Wyniki badań: Roboty nadal traktowane są głównie jako narzędzia, nie jako podmioty uczestniczące w pracy zespołu. Przekonanie, że obecność robota w zespole nie wyeliminuje człowieka, a raczej zastąpi go w wykonywaniu niebezpiecznych i niekomfortowych zadań i zapewni przestrzeń do skupienia się na bardziej kreatywnych działaniach to podstawy pozytywnej postawy do zatrudniania robotów w zespołach. – Wnioski: Konieczne jest budowanie świadomości twórców robotów, że będą one członkami zespołów, które wchodzą w relacje z ludźmi, z którymi realizują zadania zawodowe. Przygotowanie do współpracy w takich zespołach to ważne współczesne zadanie z zakresu zarządzania zasobami ludzkimi. – Wkład w rozwój dyscypliny: Badania dotyczące zespołów, w których roboty współpracują z ludźmi w roli członków zespołów pracowniczych to nowość w polskiej literaturze przedmiotu. Artykuł może być źródłem inspiracji do dalszej eksploracji tego obszaru badawczego.

  • Wzmocnienie podstaw nasypów i wykonanie platform roboczych na słabym podłożu
    • Remigiusz Duszyński
    • Katarzyna Zamara
    2024 Inżynieria i Budownictwo

    Georuszty w budownictwie infrastrukturalnym, a zwłaszcza komunikacyjnym i w geotechnice, są stosowane od dziesięcioleci. Pomimo tego wciąż stosunkowo słabo rozpowszechnione są metody projektowania rozwiązań z wykorzystaniem tych materiałów. O ile zastosowania georusztów (czy też szerzej: geosyntetyków) w konstrukcjach z gruntu zbrojonego (ściany oporowe, strome skarpy) i związane z tym metody projektowe są dobrze opisane w literaturze i normach, to znacznie skromniejsza jest dostępna wiedza na temat zastosowań związanych ze wzmocnieniem podłoża bezpośrednio pod konstrukcjami nawierzchni drogowych i kolejowych, z budową platform roboczych na gruntach o bardzo niskiej nośności, czy też ze zwiększeniem trwałości zmęczeniowej samej nawierzchni. Taka sytuacja wynika między innymi z faktu, że różne geosyntetyki, w tym różne georuszty, w różny i często bardzo odmienny sposób wpływają na nośność podłoża i trwałość konstrukcji. Stąd też – inaczej niż np. w przypadku ścian oporowych – trudno jest opracować jedną uniwersalną metodę projektową obejmującą ten zakres zastosowań. Konieczne jest opieranie się na doświadczeniach producentów poszczególnych odmian georusztów czy geosiatek oraz korzystanie z opracowanych przez nich na bazie tych doświadczeń metod projektowych. W niniejszym artykule przedstawiono technologię materacy geokomórkowych wykorzystywaną przede wszystkim w podstawie nasypów na słabych i odkształcalnych podłożach, jak również do konstrukcji tymczasowych platform roboczych. Na przykładzie zrealizowanych inwestycji dokonano analizy pracy konstrukcji w złożonych warunkach geotechnicznych. Przedstawiono rezultaty analizy wstecznej konstrukcji poddanych badaniom w skali rzeczywistej, które mogą posłużyć do wstępnej analizy rozwiązań w programach modelowania numerycznego

  • YADE - An extensible framework for the interactive simulation of multiscale, multiphase, and multiphysics particulate systems
    • Vasileios Angelidakis
    • Katia Boschi
    • Karol Brzeziński
    • Robert Caulk
    • Bruno Chareyre
    • Carlos Andrés del Valle
    • Jérôme Duriez
    • Anton Gladky
    • Dingeman L.H. van der Haven
    • Jan Kozicki
    • Gerald Pekmezi
    • Luc Scholtès
    • Klaus Thoeni
    2024 Pełny tekst COMPUTER PHYSICS COMMUNICATIONS

    This contribution presents the key elements of YADE, an extensible open-source framework for dynamic simulations. During the past 19 years, YADE has evolved from "Yet Another Dynamic Engine"' to a versatile multiscale and multiphysics solver, counting a large, active, and growing community of users and developers. The computationally intense parts of the source code are written in C++, using flexible object models that allow for easy implementation of new features. The source code is wrapped in Python, equipping the software with an interactive kernel used for rapid and concise scene construction, simulation control, post-processing, and debugging. The project, including documentation and examples, is hosted on https://yade-dem.org, while the source code is freely available on GitLab. Over the last decade, YADE has expanded in terms of capabilities thanks to the contribution of many developers from different fields of expertise, including soil and rock mechanics, chemical engineering, physics, bulk material handling, and mineral processing. The rapid growth of YADE can be attributed to (1) the careful and robust design of the framework core, (2) a continuous integration pipeline with fully embedded thorough tests which are executed upon each merge request, ensuring stable compilation for various operating systems, and (3) user-friendliness, facilitated by the Python interface, detailed documentation, and rigorous user support. In this paper, we review the main features of YADE, highlighting its versatility in terms of applications, its flexibility in terms of code development, as well as recent improvements in terms of computational efficiency.

  • Zaawansowany układ samoczynnego załączania rezerwy oparty na sterowniku WAGO PFC200
    • Andrzej Augusiak
    • Remigiusz Izbaner
    • Jakub Labudda
    2024 Wiadomości Elektrotechniczne

    Artykuł opisuje projekt i wykonanie układu samoczynnego załączania rezerwy (SZR) na potrzeby stacji elektroenergetycznej Laboratorium LINTE^2 na Politechnice Gdańskiej. Układ SZR został zbudowany na podstawie modułowego sterownika PLC WAGO PFC200. W artykule omówiono zasadę działania układu, a także jego program sterowania i aplikację panelu HMI, opracowane w zintegrowanym środowisku programistycznym CoDeSys 3.5. Oprócz zadań typowego układu SZR (takich jak sterowanie łącznikami, czy blokady przed wykonaniem niedozwolonych operacji łączeniowych), zaproponowany algorytm sterowania realizuje zaawansowane funkcje dodatkowe. Na szczególną uwagę zasługuje współpraca układu SZR z instalacją fotowoltaiczną, którą układ ten odłącza od sieci podczas realizacji zasilania rezerwowego z jednego z dwóch agregatów prądotwórczych. Innym przykładem zaawansowanych funkcji układu SZR jest wybór agregatu rezerwowego na podstawie informacji o ilości paliwa dostępnego w zbiornikach.

  • Zagrożenie porażeniem podczas gaszenia pożaru w budynkach z fotowoltaicznymi źródłami energii
    • Stanisław Czapp
    • Konrad Seklecki
    • Leszek Litzbarski
    • Marek Olesz
    2024 Pełny tekst Przegląd Elektrotechniczny

    Podczas prowadzenia akcji gaśniczej w budynku z fotowoltaicznymi źródłami energii występuje zwiększone ryzyko porażenia prądem elektrycznym ze względu to, że moduły fotowoltaiczne są źródłami autonomicznymi i mogą generować niebezpieczne napięcie mimo odłączenia inwertera zarówno od strony AC, jak i DC instalacji elektrycznej. Szczególnie duże ryzyko porażenia powstaje podczas dotknięcia przez strażaka przewodów pod napięciem przyłączonych do modułów fotowoltaicznych oraz podczas podawania na nie środka gaśniczego. W artykule przedstawiono ogólne zasady ochrony przeciwporażeniowej w instalacjach fotowoltaicznych, wyniki badań rezystancji środków ochrony osobistej strażaków i oceniono zagrożenie porażeniem podczas prowadzenia akcji gaśniczej w budynku z fotowoltaicznymi źródłami energii.

  • Zagubiona tożsamość a pomorskie doświadczenie domu. Blok i chata
    • Agnieszka Kurkowska
    2024

    Architektura jest zjawiskiem uniwersalnym i stanowi dziedzinę kulturotwórczą powiązaną ściśle z innymi dziedzinami sztuki. Stąd doświadczanie i odczuwanie tożsamości warunkowane są również właściwym formowaniem obiektów architektonicznych, będących nośnikami określonych wartości i współdecydujących o możliwości zaistnienia tego doświadczenia w powiązaniu z określonym miejscem i realizacją w nim określonej potrzeby. W epoce wszechobecnej bezrefleksyjnej konsumpcji i powszechnego unikania słowa pisanego, obiekty należące do kultury materialnej, jaką współtworzy architektura, stają się istotnymi przedmiotami procesu przekazu idei i określonych treści. Przynależność do miejsca, grupy kulturowej, społeczności, czy wspólnoty regionalnej, ma swój wyraz w świadomie projektowanych formach przestrzennych. Pomorskie doświadczenie domu można odnieść do dwóch kontrastujących sytuacji. Po pierwsze - dawnej wsi kaszubskiej z jej regionalną zabudową, gdzie dom mieszkalny stanowiła drewniana chata kaszubska. (Ta architektura, wyrastająca z uwarunkowań lokalny i osadzona kulturowo w świadomości Kaszubów, wzmacniała poczucie utożsamienia z zamieszkiwanym regionem i konkretnym miejscem.) Po wtóre – współczesnego pomorskiego osiedla, zabudowanego wieloklatkowymi, prefabrykowanymi blokami. (Wydaje się, że ten rodzaj zabudowy, pozbawiony kulturowego ukorzenienia w tradycjach regionalnych zubaża osobistą identyfikację z zamieszkiwanym budynkiem/ mieszkaniem.) Wspomniany blok stoi zazwyczaj na wielkim osiedlu z dala od lasu, łąki, wody, a chata pośród pól, czasem w pobliżu rzeki lub jeziora, gęstego boru. Coś jednak je łączy: i blok, i chata, choć tak bardzo się od siebie różnią, stanowią dla ich mieszkańców najważniejsze miejsce w przestrzeni: DOM. Przestrzeń osiedli mieszkaniowych, a także zaniedbana zabudowa niektórych wsi oczekują rewaloryzacji. Zagubionej tożsamości można poszukiwać dbając o wartościowe zamieszkiwanie. Pożądane byłyby zarówno kompetentna interwencja zewnętrzna jak i oddolne działania prowspólnotowe oparte na świadomym czym jest dom i jaki powinien, czy mógłby być. Jedną z form nieoczywistych działań w tym zakresie mogłyby być działania o charakterze intencjonalnym, artystycznym.

  • Zarządzanie dostępnością Zintegrowanych Węzłów Przesiadkowych
    • Romanika Okraszewska
    • Kazimierz Jamroz
    • Joanna Wachnicka
    • Lech Michalski
    • Krystian Birr
    • Aleksandra Romanowska
    2024

    Podstawowym celem badawczym opisanym w monografii było przedstawienie stanu prawnego (obowiązującego w Polsce na dzień dzisiejszy), stanu technicznego oraz organizacyjnego w zakresie planowania, projektowania, budowy/przebudowy oraz eksploatacji węzłów przesiadkowych w dużych miastach, z uwzględnieniem bezpieczeństwa i komfortu podróżowania osób ze szczególnymi potrzebami. Planując budowę/rozbudowę Zintegrowanego Węzła Przesiadkowego, należy zapewnić dostępność systemu transportu wszystkim grupom pasażerów. Zasady dostępności zostały wpisane w akty prawne zarówno Rzeczypospolitej Polskiej, jak i Unii Europejskiej czy Organizacji Narodów Zjednoczonych.

  • Zasady związane z dawstwem mleka ludzkiego i kryteria rekrutacji dawczyń – stanowisko ekspertów w świetle wyników najnowszych badań
    • Dorota Martysiak-Żurowska
    • Edyta Malinowska-Pańczyk
    • Agtnieszska Bzikowska-jura
    • Izabela Drążkowska
    • Aleksandra Mołas
    • Kinga Kalita-Kurzyńska
    • Aleksandra Wesołowska
    2024 Pełny tekst Standardy Medyczne Pediatria

    godnie z rekomendacjami Światowej Organizacji Zdrowia (World Health Organization, WHO), Amerykańskiej Akademii Pediatrii (American Academy of Pediatrics, AAP), Europejskiego Towarzystwa Gastroenterologii, Hepatologii i Żywienia Dzieci (European Society for Pediatric Gastroenterology, Hepatology and Nutrition, ESPGHAN) oraz Polskiej Grupy Ekspertów, mleko pochodzące z banków mleka kobiecego (BMK) jest preferowanym sposobem żywienia dzieci urodzonych przedwcześnie, w sytuacjach braku dostępu do mleka biologicznej matki. Zalecenia te opierają się na przekonujących dowodach, dotyczących mniejszego ryzyka występowania martwiczego zapalenia jelit u niemowląt karmionych mlekiem dawczyń w porównaniu z niemowlętami otrzymującymi preparaty zastępujące mleko kobiece. Beneficjentami mleka z BMK jest grupa niezwykle wrażliwych noworodków – urodzonych przedwcześnie i/lub obciążonych licznymi patologiami. Skład mleka kobiecego gromadzonego w bankach determinowany jest wieloma czynnikami, z których najważniejsze to te zależne od dawczyń pokarmu oraz sposobów postępowania z odciągniętym mlekiem, przekazanym do BMK. Ostatnie badanie ankietowe, przeprowadzone wśród pracowników polskich BMK, wykazało wiele istotnych różnic, dotyczących wymogów wobec dawczyń oraz stosowanych praktyk laboratoryjnych i procedur postępowania z mlekiem przeznaczonym do donacji. Niniejsze opracowanie jest aktualizacją rekomendacji, które pozwolą na poprawę jakości i bezpieczeństwa mleka pochodzącego od honorowych dawczyń.

  • Zastosowanie betonu jamistego jako warstwy nawierzchni obiektów inżynierskich
    • Anna Banaś
    • Michał Kałużyński
    • Andrzej Kuryłowicz
    2024 Materiały Budowlane

    Intensywny rozwój infrastruktury transportowej, przez budowę konwencjonalnych nawierzchni drogowych, powoduje przekształcanie naturalnego przepuszczalnego gruntu w nieprzepuszczalne pokrycie terenu [1 – 4]. Nawierzchnie nieprzepuszczalne przyczyniają się do zmian w środowisku lokalnym, szczególnie miejskim, które dotyczą nie tylko aspektów hydrologicznych, ale również wpływają na zmiany termiczne [5, 6]. W niniejszym artykule przedstawiono innowacyjne zastosowanie betonu jamistego, jako warstwy odsączającej w tunelu, na przykładzie tunelu na Węźle „OPL Okęcie” w Warszawie. Użycie betonu jamistego w tym przypadku pozwoliło na ekologiczne rozwiązanie, uniknięcie nadmiernej przebudowy obiektu i sprawne odprowadzenie wody. Rozwiązanie to wpisuje się w trendy zrównoważonego rozwoju miast i stanowi kompromis pomiędzy rozbudową infrastruktury drogowej, a zapewnieniem swobodnego ujścia wód gruntowych.

  • „Zdrowy” system finansowy samorządu terytorialnego fundamentem „zdrowych” finansów samorządowych
    • Maria Jastrzębska
    2024 Pełny tekst Optimum. Studia Ekonomiczne

    Celem artykułu jest identyfikacja cech, które powinny charakteryzować system finansowy samorządu terytorialnego jako fundament zdrowych finansów samorządowych. Ponadto celem artykułu jest wskazanie zmian konstrukcji systemu finansowego samorządu terytorialnego ze szczególnym uwzględnieniem systemu dochodów jednostek samorządu terytorialnego w powyższym kontekście. Wykorzystano analizę deskryptywną i porównawczą, wnioskowanie indukcyjne i dedukcyjne oraz krytyczną analizę literatury przedmiotu. Na wstępie określono cechy „zdrowego” systemu finansowego samorządu terytorialnego. Cechy „zdrowego” systemu finansowego samorządu terytorialnego związane są z jakością konstrukcji tego systemu (sposób, w jaki system został zaprojektowany i zorganizowany), jak również z jakością jego funkcjonowania w praktyce (czy system jest stabilny, skuteczny i zgodny z oczekiwaniami społeczności samorządowych). Następnie poddano ocenie nowe rozwiązania w zakresie systemu dochodów jednostek samorządu terytorialnego w kontekście zdrowych finansów samorządowych w naszym kraju. Przeprowadzono badania teoretyczne nad istotą i cechami „zdrowego” systemu finansowego samorządu terytorialnego. Badania te stanowią autorskie podejście do problematyki jakości systemu finansowego samorządu terytorialnego. Zaproponowano termin „zdrowy” system finansowy samorządu terytorialnego oraz katalog cech, którymi powinien się on charakteryzować. Poddano również ocenie nowe rozwiązania w zakresie systemu dochodów jednostek samorządu terytorialnego w Polsce w kontekście wskazanych cech „zdrowego” systemu finansowego samorządu terytorialnego.

  • Zero-Emissions, Off-grid, Autonomous Houseboat – a Case Study of Selected Locations in Europe
    • Jakub Gorzka
    • Artur Karczewski
    • Wojciech Litwin
    • Karolina Matej-Łukowicz
    • Nicole Nawrot
    • Lucyna Nyka
    • Łukasz Piątek
    2024 Polish Maritime Research

    The aim of this study was to assess the feasibility of creating a prototype of a self-sufficient houseboat that is capable of prolonged independence from power grids and freshwater sources. In this design, electricity demand is met by a photovoltaic installation, and the energy is stored in batteries. Fresh water for living needs may be obtained from many sources, depending on the environmental conditions, such as through purifying outboard water, desalinating seawater, and collecting and storing rainwater. No waste production of the vessel can be achieved in two ways: waste can be treated and discharged into a body of water, or processed into fertiliser for later use in agriculture. Four possible locations were analysed: Rome, Lisbon, Gdańsk and Stockholm. The findings reveal that the length of time for which the unit is autonomous and emission-free depends on the geographical location of the facility. In periods when there is overproduction of energy, the system can produce hydrogen, donate energy to the grid, use it for the needs of its own movement, or perform other useful work, e.g. cleaning or aerating the water body on which it is floating.

  • Zmiany składu chemicznego wód podziemnych na obszarze Żuław Wielkich w ujęciu historycznym i współcześnie
    • Małgorzata Pruszkowska-Caceres
    • Agnieszka Puskarz
    • Szymon Grabowski
    • Alicja Wolańska
    2024 Gospodarka Wodna

    Badania hydrogeologiczne Żuław Wielkich koncentrują się na zasoleniu wód podziemnych. Od początku XX wieku do chwili obecnej obserwuje się wysokie stężenia chlorków, jonów amonowych i mineralizacji we wszystkich poziomach wodonośnych. Uznaje się, iż na przeważającym obszarze nie występują tu warstwy wodonośne o znaczeniu użytkowym, a zasoby wód podziemnych Żuław Wielkich są ograniczone. Przeprowadzone badania pozwoliły na ustalenie genezy występujących problemów z jakością wód podziemnych i powiązanie ich z warunkami hydrogeologicznymi regionu.

  • ZWIĘKSZENIE EFEKTYWNOŚCI METODY ELEMENTÓW SKOŃCZONYCH Z WYKORZYSTANIEM WŁASNOŚCI GEOMETRII STRUKTUR
    • Małgorzata Warecka
    2024 Pełny tekst Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    Niniejsza praca jest omówieniem fragmentów rozprawy doktorskiej autorki. Przedstawia ideę połączenia opisu analitycznego z metodą elementów skończonych poprzez uogólnioną macierz impedancji. Przedstawione zostały analizy dwóch struktur z wykorzystaniem metody hybrydowej, które wraz z porównaniem względem innych metod stanowią potwierdzenie zasadności prezentowanego podejścia.

  • Франтішек Кржіжік – чеський Едісон
    • Dariusz Świsulski
    2024

    Франтішек Кржіжік (František Křižík) – чеський інженер-електрик, винахідник і промисловець, який зробив великий внесок у розвиток електротехнічної промисловості в Чехії. Як автора численних патентів його називають чеським Едісоном.

  • 16-kanałowy moduł LED do systemu wspomagającego rozwój roślin sterowany za pomocą Raspberry PI
    • Mateusz Feldzenstajn
    • Jerzy Pluciński
    • Sebastian Siedlecki
    • Adam Mazikowski
    2023 Pełny tekst Przegląd Elektrotechniczny

    Opracowywane są nowe rozkłady widma światła, które wpływają na poprawę zarówno ilości plonów i jakości dokonywanych zbiorów. W celu uproszczenia wprowadzania zmian widma w procesach badawczych oraz w celu przyspieszenia i zrównoleglenia badań w tym zakresie został opracowany niedrogi programowalny moduł LED pozwalający sterować 16 niezależnymi stałoprądowymi kanałami. Niska cena proponowanego rozwiązania oraz jeden sterownik obsługujący do 12 modułów LED może przyczynić się do bardziej efektywnych poszukiwań optymalnego widma dla poszczególnych gatunków roślin.

  • 2-Methoxyestradiol and Hydrogen Peroxide as Promising Biomarkers in Parkinson’s Disease
    • Paulina Bastian
    • Lucyna Konieczna
    • Jarosław Dulski
    • Agnieszka Daca
    • Dagmara Jacewicz
    • Agata Płoska
    • Narcyz Knap
    • Jarosław Sławek
    • Tomasz Baczek
    • Leszek Kalinowski
    • Joanna Drzeżdżon
    • Anna Roszmann
    • Mariusz Belka
    • Magdalena Górska-Ponikowska
    2023 Pełny tekst MOLECULAR NEUROBIOLOGY

    Estrogens function in numerous physiological processes including controlling brain cell growth and differentiation. 2-Meth- oxestradiol (2-ME2), a 17β-estradiol (E2) metabolite, is known for its anticancer effects as observed both in vivo and in vitro. 2-ME2 affects all actively dividing cells, including neurons. The study aimed to determine whether 2-ME2 is a potentially cancer-protective or rather neurodegenerative agent in a specific tissue culture model as well as a clinical setup. In this study, 2-ME2 activity was determined in a Parkinson’s disease (PD) in vitro model based on the neuroblastoma SH-SY5Y cell line. The obtained results suggest that 2-ME2 generates nitro-oxidative stress and controls heat shock proteins (HSP), resulting in DNA strand breakage and apoptosis. On the one hand, it may affect intensely dividing cells preventing cancer develop- ment; however, on the other hand, this kind of activity within the central nervous system may promote neurodegenerative diseases like PD. Thus, the translational value of 2-ME2’s neurotoxic activity in a PD in vitro model was also investigated. LC–MS/MS technique was used to evaluate estrogens and their derivatives, namely, hydroxy and methoxyestrogens, in PD patients’ blood, whereas the stopped-flow method was used to assess hydrogen peroxide (H2O2) levels. Methoxyestrogens and H2O2 levels were increased in patients’ blood as compared to control subjects, but hydoxyestrogens were simultaneously decreased. From the above, we suggest that the determination of plasma levels of methoxyestrogens and H2O2 may be a novel PD biomarker. The presented research is the subject of the pending patent application “The use of hydrogen peroxide and 17β-estradiol and its metabolites as biomarkers in the diagnosis of neurodegenerative diseases,” no. P.441360.

  • 3D Metamaterial Ultra-Wideband Absorber for curved surface
    • Mahdi Norouzi
    • Saughar Jarchi
    • Mohsen Miab
    • Meisam Esfandiari
    • Ali Lalbakhsh
    • Sławomir Kozieł
    • Sam Reisenfeld
    • Gholamhosein Moloudian
    2023 Pełny tekst Scientific Reports

    This paper proposes a three-dimensional metamaterial absorber based on a resistive film patch array to develop a low-cost, lightweight absorber for curved surfaces. An excellent absorption over a large frequency band is achieved through two different yet controllable mechanisms; In the first mechanism, a considerable attenuation in the wave power is achieved via graphite resistive films. The absorption is then intensified through magnetic dipoles created by the surface currents, leading to absorption peaks. The simulation results of the absorber show that a broadband absorption greater than 85% is achieved over 35 to 400 GHz for both TE and TM polarization waves at normal incidence. The structure has more than 167% and 80% absorption bandwidth above 85% and 90%, respectively. It is shown that the proposed metamaterial absorber is independent of incident wave polarization. In addition, the structure is insensitive to incident angle up to 60˚ for TE mode and full range angle 90˚for TM mode. To describe the physical mechanism of the absorber, E-field, power loss density and surface current distributions on the structure are calculated and shown. Moreover, the oblique incidence absorption efficiency is also explained. This absorber paves the way for practical applications, such as sensing, imaging and stealth technology. In addition, the proposed structure can be extended to terahertz, infrared and optical regions.

  • 5G Millimeter Wave Network Optimization: Dual Connectivity and Power Allocation Strategy
    • Abdulhalim Fayad
    • Tibor Cinkler
    • Jacek Rak
    2023 Pełny tekst IEEE Access

    The fifth generation (5G) of mobile networks utilizing millimeter Wave (mmWave) bands can be considered the leading player in meeting the continuously increasing hunger of the end user demands in the near future. However, 5G networks are characterized by high power consumption, which poses a significant challenge to the efficient management of base stations (BSs) and user association. Implementing new power consumption and user association strategies is imperative to address this issue. For that in this work, we focus on the Dual Connectivity-User and Power Allocation (DC-UPA) problem utilizing BS switching on/off along with user dual connectivity. The problem is mathematically formulated as an Integer Linear Program (ILP), and its NP-hardness is proven by showing its equivalence to a variant of the set covering problem. Moreover, we developed two heuristic algorithms: Simulated Annealing (SA) and Distance-Aware (DA) greedy, to mitigate the impact of the problem complexity and resolve the ILP scalability issue. We conducted extensive simulations to validate the effectiveness of the proposed heuristics in a two-dimensional area containing multiple BSs and users with uniform and nonuniform geographical distributions. The performance of the SA and DA algorithms was compared against the ILP approach. We evaluated the performance of the proposed solutions considering different aspects such as the number of users, the BS radius, and the traffic load changes. The numerical results show that SA outperforms the DA in both uniform and nonuniform geographical distributions of users. The SA provides a sub-optimal solution with an optimality gap of about 3.2%, while the optimality gap of the DA is 8.62% in the case of the uniform distribution. Moreover, the optimality gap in the case of nonuniform distribution is equal to about 1% and 5.2% of SA and DA, respectively. Additionally, by utilizing our solutions, the reduction of the level of power consumption up to 16.1% and 20% in the case of uniform and nonuniform distributions can be achieved. The obtained results highlight the efficiency of the proposed algorithms in addressing the DC-UPA problem, providing practical solutions for managing power consumption and maintaining continuous user connectivity in 5G mmWave networks.

  • 5G/6G optical fronthaul modeling: cost and energy consumption assessment
    • Abdulhalim Fayad
    • Tibor Cinkler
    • Jacek Rak
    2023 Pełny tekst Journal of Optical Communications and Networking

    In fifth generation (5G) and the future beyond 5G (6G) radio access networks (RANs), the cost of fronthaul deployment is a main challenge for mobile network operators. Depending on different constraints, there are various solutions to deploy an efficient fronthaul. Fiber-optic-based fronthaul offers long-term support with regard to a rapid increase in capacity demands. When fiber connections, either point-to-point (P2P) or point-to-multipoint [i.e., passive optical networks (PONs)], are not available due to economic or geographical constraints, new optical fronthaul solutions such as free space optics (FSO) can be applied. Before deploying any optical fronthaul architecture, mobile operators must assess its impact on the total cost of ownership (TCO) of the network (i.e., capital and operational expenditures). To assist operators in choosing the most cost-effective fronthaul architecture, in this paper, we show how to evaluate the TCO of 5G and beyond RANs while taking various fronthaul architectures (P2P, PON, and hybrid PON-FSO) into consideration. Furthermore, this paper answers the question of how much energy is needed to run a network using each of the considered optical fronthaul architectures. To do so, we propose a holistic framework based on an integer linear program that minimizes the TCO of the network. Furthermore, we propose a heuristic algorithm to solve large-sized problems. We run simulations to compare different fronthaul architectures for two deployment areas: dense and sparse.

  • A Bayesian regularization-backpropagation neural network model for peeling computations
    • Saipraneeth Gouravaraju
    • Jyotindra Narayan
    • Roger Sauer
    • Sachin Singh Gautam
    2023 Pełny tekst JOURNAL OF ADHESION

    A Bayesian regularization-backpropagation neural network (BRBPNN) model is employed to predict some aspects of the gecko spatula peeling, viz. the variation of the maximum normal and tangential pull-off forces and the resultant force angle at detachment with the peeling angle. K-fold cross validation is used to improve the effectiveness of the model. The input data is taken from finite element (FE) peeling results. The neural network is trained with 75% of the FE dataset. The remaining 25% are utilized to predict the peeling behavior. The training performance is evaluated for every change in the number of hidden layer neurons to determine the optimal network structure The relative error is calculated to draw a clear comparison between predicted and FE results. It is shown that the BR-BPNN model in conjunction with the k-fold technique has significant potential to estimate the peeling behavior.

  • A BODIPY‐Based Molecular Rotor in Giant Unilamellar Vesicles: A Case Study by Polarization‐Resolved Time‐Resolved Emission and Transient Absorption Spectroscopy
    • Keshav Kumar Jha
    • Amrutha Prabhakaran
    • Lukas Spantzel
    • Rengel Cane Sia
    • Iván Pérez
    • Ruben Arturo Arellano-Reyes
    • Anna Elmanova
    • Anindita Dasgupta
    • Christian Eggeling
    • Michael Börsch
    • Julien Guthmuller
    • Martin Presselt
    • Tia E. Keyes
    • Benjamin Dietzek-Ivanšić
    2023 Pełny tekst ChemPhotoChem

    BODIPY and BODIPY-derived systems are widely applied as fluorophores and as probes for viscosity detection in solvents and biological media. Their orientational and rotational dynamics in biological media are thus of vital mechanistic importance and extensively investigated. In this contribution, polarization-resolved confocal microscopy is used to determine the orientation of an amphiphilic BODIPY-cholesterol derivative in homogeneous giant unilamellar vesicles (GUV) made from 1,2- dioleoyl-sn-glycero-3-phosphocholine (DOPC). The BODIPY-moiety of the molecule is placed near the polar head groups, and the cholesterol moiety is embedded in the membrane along the acyl chain of the lipids. The rotational relaxation of fluorophore is conventionally investigated by time-resolved emission anisotropy (TEA); and this method is also used here. However, TEA depends on the emission of the fluorophore and may not be useful to probe rotational dynamics of the nonemissive triplet states. Thus, we employ femtosecond transient absorption anisotropy (TAA), that relies on the absorption of the molecule to complement the studies of the amphiphilic BODIPY in DCM and GUV. The photoinduced anisotropy of the BODIPY molecule in DCM decays tri-exponentially, the decay components (sub-5 ps, 43 ps and 440 ps) of anisotropy are associated with the non-spherical shape of the BODIPY molecule. However, the anisotropy decay in homogenous GUVs follows a biexponential decay; which arises from the wobblingin-a-cone motion of the non-spherical molecule in the high viscous lipid bilayer media. The observations for the BODIPYchol molecule in the GUV environment by TAA will extend to the investigation of non-emissive molecules in cellular environment since GUV structure and size resembles the membrane of a biological cell.

  • A brief note on entire fracture surface topography parameters for 18Ni300 maraging steel produced by LB-PBF after LCF
    • Wojciech Macek
    • Ricardo Branco
    • Przemysław Podulka
    • Mateusz Kopec
    • Shun-Peng Zhu
    • José Domingos Costa
    2023 ENGINEERING FAILURE ANALYSIS

    The concept of entire fracture surface investigation is helpful in explaining fatigue phenomena. In this paper, this method has been applied for 18Ni300 maraging steel using a 3D measurement system. Before post-mortem analysis, the specimens produced by laser beam powder bed fusion (LB-PBF) were tested under low-cycle fatigue (LCF) for eight strain amplitudes in the interval 0.3% to 1.0%. The attention was placed on the relationship between the fatigue features, represented by the strain level and the fatigue life as well as the fracture surface topography evaluated in the form of areal, volume and fractal dimension parameters. It was found that fatigue life predictions calculated using the core material volume Vmc, obtained with the entire fracture surface method were within a scatter band with factors of ±1.5. The present results can be useful for the analysis of damaged structural elements exposed to LCF, especially for materials produced by additive manufacturing (AM). The outcomes of this brief note are important for the development of other fractographic methods and validation of fatigue life evaluation procedures.

  • A CNN based coronavirus disease prediction system for chest X-rays
    • Umair Hafeez
    • Muhammad Umer
    • Ahmad Hameed
    • Hassan Mustafa
    • Ahmed Sohaib
    • Michele Nappi
    • Hamza Madni
    2023 Journal of Ambient Intelligence and Humanized Computing

    Coronavirus disease (COVID-19) proliferated globally in early 2020, causing existential dread in the whole world. Radiography is crucial in the clinical staging and diagnosis of COVID-19 and offers high potential to improve healthcare plans for tackling the pandemic. However high variations in infection characteristics and low contrast between normal and infected regions pose great challenges in preparing radiological reports. To address these challenges, this study presents CODISCCNN (CNN based Coronavirus DIsease Prediction System for Chest X-rays) that can automatically extract the features from chest X-ray images for the disease prediction. However, to get the infected region of X-ray, edges of the images are detected by applying image preprocessing. Furthermore, to attenuate the shortage of labeled datasets data augmentation has been adapted. Extensive experiments have been performed to classify X-ray images into two classes (Normal and COVID), three classes (Normal, COVID, and Virus Bacteria), and four classes (Normal, COVID, and Virus Bacteria, and Virus Pneumonia) with the accuracy of 97%, 89%, and 84% respectively. The proposed CNN-based model outperforms many cutting-edge classifcation models and boosts state-of-the-art performance.

  • A commonly-accessible toolchain for live streaming music events with higher-order ambisonic audio and 4k 360 vision
    • Bartłomiej Mróz
    • Piotr Odya
    • Przemysław Danowski
    • Marek Kabaciński
    2023 Pełny tekst

    An immersive live stream is especially interesting in the ongoing development of telepresence tools, especially in the virtual reality (VR) or mixed reality (MR) domain. This paper explores the remote and immersive way of enabling telepresence for the audience to high-fidelity music performance using freely-available and easily-accessible tools. A functional VR live-streaming toolchain, comprising 360 vision and higher-order ambisonic audio, is presented and described in detail. Two separate recordings with two different approaches are outlined. The results gathered from the audiences' impressions are discussed. Finally, possible improvements to the immersive live streaming and recording processes were discussed.

  • A Compact Self-Hexaplexing Antenna Implemented on Substrate-Integrated Rectangular Cavity for Hexa-Band Applications
    • Rusan Kumar Barik
    • Sławomir Kozieł
    2023 IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS

    This brief introduces a novel architecture of a compact self-hexaplexing antenna (SHA) implemented on a substrate-integrated rectangular cavity (SIRC) for hexa-band applications. The proposed SHA is configured by using an SIRC resonator, two Pi-shaped slots (PSSs), and six 50Ω microstrip feedlines. The PSSs are connected back-to-back and loaded on top of the SIRC resonator to produce six patch radiators (PRs). The PRs are excited by 50Ω feedlines to radiate at six operating bands with self-multiplexing characteristics. The operating bands are tunable. A particular band can be adjusted independently based on the system requirement without altering the other operating bands. A comprehensive parametric study is carried out to allow a suitable band tunability, high isolation, and matching at the ports. For validation, an SIRC-based SHA radiating at 2.29, 2.96, 4.3, 5.0, 5.61, and 6.18 GHz is fabricated and experimentally demonstrated. The proposed SHA allows us to achieve a compact size of 0.173λg2, which is the smallest among the self-quadruplexing antennas and self-multiplexing antennas reported in the literature thus far. Additionally, it exhibits high isolation of 27 dB, hexa-band operation, a tunability range from 2.2 GHz to 8 GHz, along with measured gains greater than 3.73 dBi.

  • A comparative study of pentanol (C5 alcohol) and kerosene blends in terms of gas turbine engine performance and exhaust gas emission
    • Tomasz Suchocki
    • Paweł Kazimierski
    • Piotr Lampart
    • Katarzyna Januszewicz
    • T. Białecki
    • Bartosz Gawron
    • A. Janicka
    2023 FUEL

    The growing demand for sustainable and clean energy sources provides the incentive for the development of alternative fuels. Simultaneously, the development of gas turbine technologies with flexible fuel supply systems enables the use of alternative non-fossil fuels that can play key roles in contributing to global efforts in meeting emissions targets. This paper presents the current state of knowledge on the production and potential use of pentanol (C5 alcohol) in diesel engines and gas turbines. The combustion performance of a GTM-140 jet engine supplied by mixtures of pentanol with aviation kerosene is then evaluated and the results are compared with those of kerosene mixtures with other biofuels – propanol (C3 alcohol)) and butanol (C4 alcohol)). All the investigated liquid biofuel alternatives showed potential for reducing regulated emissions such as NOX (on average by 40%) and CO (on average by 25%) for C5 alcohol. The increase in the proportion of pentanol in the blends has the effect of reducing the temperature downstream of the combustion chamber on average by 5.8% for Turbine Inlet Temperature (TIT) and 6.1% for Exhaust Gas Temperature (EGT). The jet engine fuel efficiency expressed as thrust specific fuel consumption (TSFC) for all tested biofuels decreased on average by 40% for C5 alcohol. The use of alternative fuels such as bio-alcohols offers real opportunities for cleaner and more envi- ronmentally friendly gas turbine operation in aviation and power generation.

  • A comprehensive approach to SBR modelling for monitoring and control system design
    • Tomasz Ujazdowski
    • Tomasz Zubowicz
    • Robert Piotrowski
    2023 Journal of Water Process Engineering

    The aim of this research is to provide a comprehensive description of the Sequencing Batch Reactor (SBR) modelling for monitoring, control, and plant operational optimisation validation. The paper provides a detailed modelling of the SBR, its components and constituent processes. For this purpose, the mass balance principle and continuity equations were provided with a reactive term implemented using Activated Sludge Model (ASM). The spatially discretised models (along the vertical axis) are then used in numerical experiments. Simulations performed enable comparison of the impact of different models of activated sludge settling velocity, as well as two different approaches to modelling reactions in the SBR. The latter was achieved by using the ASM2d and ASM3-BioP extended with an enzyme group modelling the lag phase observed in microorganisms during a rapid change in environmental conditions. The presented results have been obtained using the model of the SBR at Swarzewo in the North of Poland.

  • A comprehensive lipidomic analysis of oilseeds using LC-Q-TOF-MS and dispersive micro-solid phase (D-μ-SPE) extraction techniques
    • Inal Bakhytkyzy
    • Weronika Hewelt-Belka
    • Agata Kot-Wasik
    2023 JOURNAL OF FOOD COMPOSITION AND ANALYSIS

    Growing public health awareness increased the demand for natural products with positive health benefits. Vegetable oils containing omega-3 fatty acids (FA) such as alpha-linolenic acid (ALA) has been proposed as a possible source of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). In this work, a comprehensive lipidome analysis and comparison of seven oilseeds, including flaxseed, chia, hemp, black cumin, white sesame, black sesame and poppy using dispersive micro-solid phase extraction (D-μ-SPE) coupled with liquid chromatography quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS) was performed. The detailed characterisation of oilseed lipid profiles was presented. The identified lipid classes included lysophosphatidylcholines (LPC) and lysophosphatidylethanolamine (LPE), glycerophosphatidylcholines (PC) and glycerophosphatidylethanolamines (PE), diacylglycerols (DG), and triacylglycerols (TG). Multivariate data analysis demonstrated that flax, hemp, and chia seeds were very similar in their lipid content. These seeds contained higher amounts of lipids with less saturated FA substituents, while black cumin, black and white sesame samples shared similar lipid composition with more saturated FA substituents. ALA and linoleic acid (LA) were present in all detected classes of lipids

  • A Comprehensive Review of Phytonutrients as a Dietary Therapy for Obesity
    • Shahida Anusha Siddiqui
    • Iskandar Azmy Harahap
    • Priyanka Suthar
    • Yuan Seng Wu
    • Nibedita Ghosh
    • Roberto Castro Munoz
    2023 Pełny tekst Foods

    Obesity is a complex medical condition mainly caused by eating habits, genetics, lifestyle, and medicine. The present study deals with traditional diets like the Mediterranean diet, Nordic diet, African Heritage diet, Asian diet, and DASH, as these are considered to be sustainable diets for curing obesity. However, the bioavailability of phytonutrients consumed in the diet may vary, depending on several factors such as digestion and absorption of phytonutrients, interaction with other substances, cooking processes, and individual differences. Hence, several phytochemicals, like polyphenols, alkaloids, saponins, terpenoids, etc., have been investigated to assess their efficiencies and safety in the prevention and treatment of obesity. These phytochemicals have anti-obesity effects, mediated via modulation of many pathways, such as decreased lipogenesis, lipid absorption, accelerated lipolysis, energy intake, expenditure, and preadipocyte differentiation and proliferation. Owing to these anti-obesity effects, new food formulations incorporating these phytonutrients were introduced that can be beneficial in reducing the prevalence of obesity and promoting public health.

  • A comprehensive review on Ginger (Zingiber officinale) as a potential source of nutraceuticals for food formulations: Towards the polishing of gingerol and other present biomolecules
    • Clarissa Garza-Cadena
    • Daniela Marian Ortega-Rivera
    • Gerson Machorro-García
    • Eloy Mauricio Gonzalez-Zermeño
    • Diego Homma-Dueñas
    • Maksymilian Plata-Gryl
    • Roberto Castro-Muñoz
    2023 Pełny tekst FOOD CHEMISTRY

    Currently, ginger is one the most consumed plants when dealing with the treatments of various illnesses. So far, it is known that various biologically active molecules, such as gingerols, shogaols and zingerone, among others, are the main responsible for specific biological activities, opening a new window for its utilization as a nutraceutical in foods. In pioneering extraction processes, solvent extraction has been initially used for these applications; however, the drawbacks of this typical extraction method compared with other emergent separation techniques make it possible for the exploration of new extraction pathways, including microwave, ultrasound, supercritical, subcritical and pressurized-assisted extraction, along with three phase partitioning, high-speed counter current chromatography and magnetic solid phase extraction. To the best of our knowledge, there is no report documenting the recent studies and cases of study in this field. Therefore, we comprehensively review the progress and the latest findings (over the last five years) on research developments, including patents and emerging extraction methods, aiming at the purification of biologically active molecules (gingerols, shogaols and zingerone) contained in ginger. Over the course of this review, particular emphasis is devoted to breakthrough strategies and meaningful outcomes in ginger components extraction. Finally, dosage and safety concerns related to ginger extracts are also documented.

  • A Computational Analysis of the Aerodynamic and Aeromechanical Behavior of a Thermo-Well for Steam Temperature Measurement in a Steam Turbine
    • Mariusz Banaszkiewicz
    • Janusz Badur
    • Sebastian Kornet
    • Daniel Sławiński
    • Bartosz Kraszewski
    • Paweł Ziółkowski
    • Anna Rehmus-Forc
    • Grzegorz Bzymek
    2023 HEAT TRANSFER ENGINEERING

    The goal of the paper is twofold: firstly, it presents computational fluid dynamics analysis for finding maximum unsteady flow forces (and their frequencies) acting on a thermo-well for measuring steam temperature in a steam turbine control stage and secondly, it presents computational solid dynamics analysis of possibility of entry into resonance of the thermowell structure. There have been analyzed two cases of flow with changing temperature, pressure, and mass flow rate in the control stage chamber of a turbine high-pressure cylinder. The problem is also described in the ASME standard PTC19.3 TW-2010 providing detailed guidelines for thermo-well calculations. The problem under consideration is only a part of whole technical analysis and obeys a primary hypothesis that a reason of the thermo-well damage was a resonance phenomenon.

  • A Concept for Safe and Less Expensive Acceleration of a Marine Steam Turbine Start-up
    • Mateusz Bryk
    • Jerzy Głuch
    2023 Journal of Marine Science and Application

    This paper analyses the issue of accelerated start-up of a marine steam turbine, which is an important problem because the start-up of a steam machine involves the combustion of fuel that is not transformed into useful energy. To find novel technologies that offer improvements in this aspect is essential due to restrictions on reducing ship emissions. Thus, the shorter the start-up time, the better for the environment and economy. High-pressure (HP) part of the turbine originally located on the Queen Elizabeth II unit was analysed. Advanced numerical calculations by thermal fluid-solid-interaction (Thermal FSI) were carried out. A series of simulations were performed for the accelerated start-up with controlled steam injection. A description of the chosen calculation methodology and the results obtained by simulation are included in this paper. The stress occurring during the accelerated start-up are approximately 40 MPa higher than those during the reference start-up. The relative elongations between the rotor and the hull during accelerated start-up reach a maximum value of 0.89 mm (0.83 mm for ultra-fast start-up). Reducing the steam turbine start-up time by 75% results in a 36.7 tons reduction in fuel consumption for start-up, resulting in an annual savings of 5 372 USD. In conclusion, the concept proposed by the authors is safe, less expensive and does not affect the life of the turbine. In addition, results and applications from Siemens prove that additional injection of cooling steam is possible.

  • A critical review on electrospun membranes containing 2D materials for seawater desalination
    • Roberto Castro-Muñoz
    2023 DESALINATION

    Electrospun nanofibers are a cutting-edge class of membranes which have been applied in several molecular separations. These membranes can be well designed and tailored due to the versatility of the electrospinning process. Eminently, electrospun membranes, once implemented in membrane processes, are an alternative in removing salts and some other minerals from water, so-called desalination, for producing drinking water. Such membranes present unique properties over traditional membranes, such as outstanding performance thanks to the high porosity, adjustable pore size, and functionalized surface of the nanofibrous. Today, electrospun membranes are denominated as a “hot” topic in research for desalination purposes in which mainly polymer phases are used in membrane fabrication, however, a current trend deals with the doping of such polymer phases with two-dimensional (2D) materials, such as graphene, graphene oxide, MXene, boron and carbon nitrides, among others. Apart from their extraordinary physical and chemical properties, these latter materials exhibited unprecedented water transport rates, making them suitable for preparing more attractive membranes for desalination. Therefore, the aim of this comprehensive review is to reveal the latest advances in electrospun membranes containing 2D materials. Particular emphasis has been devoted to the reports published over the last two years, from 2020 up to now. In this review, apart from reporting the breakthroughs in membrane preparation and their desalination performance data, the main advantages and drawbacks of the developed membranes are elucidated. Finally, after analysing the recent literature, tentative research gaps and recommendations to the new researchers in the field are also stated.

  • A Diagnostic Method Based on Deflection Analysis for Monitoring Post-elastic Response of Beams
    • Adam Ścięgaj
    2023 Pełny tekst International Journal of Civil Engineering

    A non-destructive diagnostic method based on deflection analysis for monitoring the post-elastic response of beams was developed, and a diagnostic indicator was proposed. The indicator was defined as the second moment of the normalised curvature function about the mid-span, where the curvature was computed from the normalised deflection function. Elastic reference values of the indicator were computed for simply supported beams under uniformly distributed load, three-point, and four-point bending. Development of the indicator under progressive loading was examined with the help of finite element analyses. The indicator value monotonically decreased with increasing deformation provided that maximum bending moment was located between 0.41L and 0.59L, where L is the span of the beam. In this interval, the value of the indicator was unique and enabled the direct monitoring of the post-elastic stress level in the cross-section. The method was validated with the help of available experiments on simply supported beams. For beams working in the elastic range, a mean error of 2:1% was obtained between the measured and theoretical indicator values. For quasi-brittle material in the post-elastic stage, the decreasing value of the indicator signified the development of damage in accordance with experi- mental results.

  • A facile strategy for reclaiming discarded graphite and harnessing the rate capabilities of graphite anodes
    • Honghong Tian
    • Magdalena Graczyk-Zajac
    • Dario M. De Carolis
    • Chuanmu Tian
    • Emmanuel III Ricohermoso
    • Zhiwu Yang
    • Wei Li
    • Monika Wilamowska-Zawłocka
    • Jan P. Hofmann
    • Anke Weidenkaff
    • Ralf Riedel
    2023 Pełny tekst JOURNAL OF HAZARDOUS MATERIALS

    Graphite negative electrodes are unbeaten hitherto in lithium-ion batteries (LiBs) due to their unique chemical and physical properties. Thus, the increasing scarcity of graphite resources makes smart recycling or repurposing of discarded graphite particularly imperative. However, the current recycling techniques still need to be improved upon with urgency. Herein a facile and efficient hydrometallurgical process is reported to effectively regenerate aged (39.5 %, 75 % state-of-health, SOH) scrapped graphite (SG) from end-of-life lithium-ion bat- teries. Ultimately, the first cycle reversible capacity of SG1 (SOH = 39.5 %) improved from 266 mAh/g to 337 mAh/g while 330 mAh/g (98 %) remain after 100 cycles at 0.5 C. The reversible capacity for the first cycle of SG2 (SOH = 75 %) boosted from 335 mAh/g to 366 mAh/g with the capacity retention of 99.3 % after 100 cycles at 0.5 C, which is comparable with the benchmark commercial graphite. The regenerated graphites RG1 and RG2 exhibit excellent output characteristics even increasing the rate up to 4 C. This is the best rate level reported in the literature to date. Finally, the diffusion coefficient of Li ions during deintercalation and intercalation in the regenerated graphites have been measured by galvanostatic intermittent titration technique (GITT), determining values 2 orders-of-magnitude higher than that of the spent counterparts. Taking advantage of the synergistic effect of acid leaching and heat treatment, this strategy provides a simple and up-scalable method to recycle graphitic anodes.

  • A first-principles study of electronic and magnetic properties of 4d transition metals doped in Wurtzite GaN for spintronics applications
    • Omkar A. Shilkar
    • Rajendra Adhikari
    • Subrahmanyam Sappati
    • Shreya Godi
    • Ashish M. Desai
    2023 Pełny tekst JOURNAL OF MOLECULAR MODELING

    We studied the electronic and magnetic properties of wurtzite GaN (w-GaN) doped with different concentrations of the 4d transition metal ions Nb, Mo, and Ru. We incorporated spin-polarized plane-wave density functional theory within an ultrasoft pseudopotential formalism. The 4d transition metals were doped at different geometrical sites to determine the geometry with the lowest total energy and the one that induced the largest magnetization. A spin-spin interaction study was performed to determine whether the doped compound was ferromagnetic or antiferromagnetic. The origin of magnetization in the transition metal-doped w-GaN compounds is due to the p-d hybridization of the nitrogen and 4d transition metals. From the bulk modulus results, we inferred that the structural integrity is preserved under compressive loads after doping w-GaN with these 4D transition metal ions. Our results indicate that these compounds can be used in spintronic applications.

  • A Five-Leg Three-Level Dual-Output Inverter
    • Charles Odeh
    • Arkadiusz Lewicki
    • Marcin Morawiec
    • Joseph O. Ojo
    2023 Pełny tekst IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS

    Classical 3-level dual-output inverter, 3-L DOI, involves two similar 3-level inverters that provides a pair of 3-phase output voltages with same or different frequencies from common input voltage source. Flexibility of either operation of the constituting inverters is evident in this DOI; but total duplication of power switches is a major drawback. State of the art coupled 3-L DOIs reduce this drawback by providing series-shared power devices between the two different 3-phase output terminals. Compared with the classical 3-L DOI, these newly developed coupled 3-L DOIs involves a smaller number of power switches; however, independent operation of the constituting inverters is lost. In this brief, a 3-L DOI is proposed which involves lesser number of power devices and provides flexibility of either operation of the constituting inverters. The 3-L DOI feature hinges on the concept of parallel-common-inverter-leg representation. At the same or varying frequency mode operation, the proposed inverter can synthesize two 3-phase output voltages. Range and relation between the two modes of operations are defined for the DOI. The control strategy is based on the single triangular carrier sinusoidal pulse-width modulation perspective. Experimental results are presented that depict the DOI inverter performances.

  • A Formal Approach to Model the Expansion of Natural Events: The Case of Infectious Diseases
    • Maria Teresa Signes-Pont
    • Joan Boters Pitarch
    • Julian Szymański
    • Higinio Mora-Mora
    2023 Parallel Processing Letters

    A formal approach to modeling the expansion of natural events is presented in this paper. Since the mathematical, statistical or computational methods used are not relevant for development, a modular framework is carried out that guides from the external observation down to the innermost level of the variables that have to appear in the future mathematical-computational formalization. As an example we analyze the expansion of Covid-19. We perform a qualitative estimation of the impact of the causes on the delays of the spread and an analysis of the parameters.

  • A framework estimating the minimum sample size and margin of error for maritime quantitative risk analysis
    • Romanas Puisa,
    • Przemysław Krata
    • Jakub Montewka
    2023 Pełny tekst RELIABILITY ENGINEERING & SYSTEM SAFETY

    The average accident frequency is essential for quantitative risk analysis and is conventionally estimated from accident statistics. This paper has systematically synthesised the knowledge on statistical errors and offered the missing instructions, a framework, for determining the minimum sample size and the margin of error (MOE) when calculating the average accident frequency from an accident database at hand. We have applied this framework to representative accident datasets in the maritime domain and presented the revealing results that can already be used in QRAs based on these datasets. The findings are useful to both QRA analysts and policy makers. Interestingly, the framework application has revealed that the determined minimum sample sizes would exceed the datasets available in existing maritime casualty databases by decades, requiring at least 10% MOE to be factored into pertinent QRAs. By the same token, the earlier notable QRAs (developed as part of formal safety assessments in support of rule making) had to consider the MOE of over 30%, given the sample sizes used, likely shifting the conclusions they arrived at. Other findings of the application have shown that the average accident frequencies for large passenger ships have remained constant over the past 40 years.

  • A framework of open government data (OGD) e-service quality dimensions with future research agenda
    • Charalampos Harris Alexopoulos
    • Stuti Saxena
    • Nina Rizun
    • Shao Deo
    2023 Pełny tekst Records Management Journal

    Purpose This research paper aims to present a framework of open government data (OGD) relating to e-service quality dimensions. In addition, it provides a research agenda for the e-service delivery of OGD. Design/methodology/approach A literature review pertaining to e-service quality with special reference to e-government was delivered to deduce the key dimensions of e-service quality for OGD. Findings Five e-service quality dimensions of OGD are identified in the study; website design, fulfilment, service provision to the user while interfacing with the OGD Web portal, service provision to the user during and after the value-creation and innovation period and security/privacy. To further OGD re-use for value creation and innovation, it is important that the e-service quality dimensions are built into all OGD programmes by public authorities. Originality/value Hitherto, extant research has focused on the data quality dimensions of OGD, but the dimensions linked with e-service have not been explored. This study seeks to fill this gap and, in addition, suggests further research requirements in this field.

  • A Generalized Version of the Lions-Type Lemma
    • Magdalena Chmara
    2023 Pełny tekst Annales Mathematicae Silesianae

    In this short paper, I recall the history of dealing with the lack of compactness of a sequence in the case of an unbounded domain and prove the vanishing Lions-type result for a sequence of Lebesgue-measurable functions. This lemma generalizes some results for a class of Orlicz–Sobolev spaces. What matters here is the behavior of the integral, not the space

  • A Generative Approach to Hull Design for a Small Watercraft
    • Artur Karczewski
    • Janusz Kozak
    2023 Pełny tekst Polish Maritime Research

    In the field of ocean engineering, the task of spatial hull modelling is one of the most complicated problems in ship design. This study presents a procedure applied as a generative approach to the design problems for the hull geometry of small vessels using elements of concurrent design with multi-criteria optimisation processes. Based upon widely available commercial software, an algorithm for the mathematical formulation of the boundary conditions, the data flow during processing and formulae for the optimisation processes are developed. As an example of the application of this novel approach, the results for the hull design of a sailing yacht are presented.

  • A hybrid approach to optimization of radial inflow turbine with principal component analysis
    • Łukasz Witanowski
    • Paweł Ziółkowski
    • Piotr Klonowicz
    • Piotr Lampart
    2023 ENERGY

    Energy conversion efficiency is one of the most important features of power systems as it greatly influences the economic balance. The efficiency can be increased in many ways. One of them is to optimize individual components of the power plant. In most Organic Rankine Cycle (ORC) systems the power is created in the turbine and these systems can benefit from effective turbine optimization. The paper presents the use of two kinds of hybrid stochastic/deterministic methods for 3D blade shape optimization of a 10 kW single-stage radial inflow turbine (RIT) and compares the obtained results with those received from the stochastic or deterministic methods. Eight algorithms were used altogether, including one stochastic, three deterministic and four hybrid algorithms. Principal component analysis (PCA) was used to analyze the optimization process. 3D models of selected reference and optimized geometries were created to compare the differences in the obtained flow characteristics. At least two different geometries were found for which the efficiency increased by above 2 pp. (validated on refined grids). The increased efficiency was obtained over the entire investigated range of mass flow rate, with a value of the total-to-static efficiency of 90.6% at the nominal point obtained using a hybrid method.

  • A Low-Cost System for Far-Field Non-Anechoic Measurements of Antenna Performance Figures
    • Jan Olencki
    • Vorya Waladi
    • Adrian Bekasiewicz
    • Leifur Leifsson
    2023 Pełny tekst IEEE Access

    Prototype measurements are the key step in the development of antenna structures. Typically, their far-field characteristics are validated in expensive, dedicated facilities such as open range sites, or anechoic chambers. Despite being necessary for obtaining high-precision data (e.g., for device qualification), the use of costly infrastructure might not be fully justified when the main goal of measurements includes demonstration of the methodology behind determination of the performance figures of interest (e.g., for the purpose of teaching), or rough validation of the EM simulation model correctness. From this perspective, systems for far-field measurements in non-anechoic environments represent an interesting alternative to the utilization of the state-of-the-art equipment and facilities. Despite their proven usefulness, the mentioned systems are normally constructed around the expensive, laboratory-grade equipment, which contradicts the whole concept of low-cost measurements. This paper discusses a cost-efficient, mobile system for experimental validation of antennas. Its main components include the in-house developed rotary heads, an open-hardware-based vector network analyzer, and the measurements post-processing software. The cost of the system amounts to only around 3630 USD. The capabilities of the device have been demonstrated through measurements of two antenna structures. The considered performance figures include radiation pattern and single-direction gain vs. frequency. Comparisons against the measurements performed in benchmark conditions (anechoic chamber), as well as using professional network analyzer have also been provided. Furthermore, the documentation that facilitates the construction of the system components is shared in an online repository.

  • A mechanistically approached review upon assorted cell lines stimulated by athermal electromagnetic irradiation
    • Khadijeh Askaripour
    • Arkadiusz Żak
    2023 Pełny tekst CELL CYCLE

    The probable influence of electromagnetic irradiation on cancer treatment has been deduced from the interaction of artificial electromagnetic emissions with biological organisms. Nonetheless, the suspected health effects induced by electromagnetic-based technology imply that such a treatment may contaminate the adjacent healthy cells. Thus, gaining mechanistic insights into the problem is required to avoid athermal health hazards. To tackle that, the current review, based upon in vitro studies into assorted cell lines, depicts the alterations in physiological processes triggered by electromagnetic irradiation via addressing gene regulatory cascades. Furthermore, decisive factors in the hypothesized cause-effect linkage in terms of the cell line-associated, exposure-associated, or endpoint-associated parameters are highlighted. As a result, subcellular structures such as aberrant Ca2+ channels, rich glycocalyx charge, or high water content in cancerous cells, which have attracted a great deal of attention, can explain their higher susceptibility compared with healthy cells under irradiation. Affected by cell components or geometry, the cellular biological window correlates with the metabolic or cell cycle status and determines the irradiation that causes the maximum influence. For instance, correlations between the frequency (or intensity) of irradiation and cell excitability or between the duration of irradiation and cell doubling time are observed. There are unspecified signaling pathways such as the pathway of PPAR-γ or MAPKs, and also proteins devoid of any investigation such as p14, or S phase-related and G2 phase-related proteins. Other chains, such as the cAMP connection with mitochondrial ATP or ERK signaling, the association of Hsps releases with signaling pathways of MAPKs, or the role of different ion channels in regulating various cell processes, require further investigation.

  • A Monte Carlo Strategy to simulate Positrons and Positronium in biological Materials
    • Małgorzata Franz
    • Jan Franz
    2023 Pełny tekst Bio-Algorithms and Med-Systems

    We present an algorithm for Monte Carlo simulations of positron tracks in biological materials. The algorithm takes into account the cross-section data for elastic and inelastic collisions between positrons and molecules and processes like direct annihilation, ionization and positronium formation. In the case of positronium formation, the algorithm considers the interactions of positronium with molecules. The algorithm can be used to identify the processes that are responsible to determine the lifetime of the positrons and their annihilation mechanism (direct or through positronium formation).

  • A multi‑criteria approach to investigate spatial distribution,sources, and the potential toxicological effect of polycyclic aromatic hydrocarbons (PAHs) in sediments of urban retention tanks
    • Nicole Nawrot
    • Anna Pouch
    • Karolina Matej-Łukowicz
    • Ksenia Pazdro
    • Muhammad Mohsin
    • Shahabaldin Rezania
    • Ewa Wojciechowska
    2023 Pełny tekst ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH

    Bottom sediments deposited in retention tanks (RTs) located on two urban streams (Oliwski and Strzyza) in the central part of Gdansk (Poland) were analysed for polycyclic aromatic hydrocarbons’ (PAHs) content. PAHs were extracted from samples with methylene chloride, then the extracts were subjected to clean-up applying the solid phase extraction (SPE) method. Quantitative and qualitative determination of 16 PAHs was performed with the use of gas chromatography/mass spectrometry technique. A multi-dimensional approach was applied to analyse PAHs’ spatial distribution, source, and contamination status. Potential sources of PAHs were verified using isomer ratios supported by a statistical approach. The Σ16PAHs (in mg/kg d.w.) ranged from 1.95 ± 0.64 to 20.4 ± 6.8 for RTs located on the Oliwski Stream and from 0.50 ± 0.17 to 8.6 ± 2.9 for RTs located on the Strzyza Stream. PAHs detected in bottom sediments were mainly composed of 4- and 5-ring compounds. PAH isomer ratios such as Phen/Anth, Flth/Pyr, B(a)A/B(a)A + Chry, Inpy/Inpy + B(ghi)P, Flth/Flth + Pyr, Anth/Anth + Phen, and Flth/Flth + Pyr suggested delivery pathways for biomass, coal, and petroleum combustion. Petrogenic PAHs related to fuel leaks from cars were not detected. Statistical analyses confirmed traffic and heating system sources, while factor analysis (FA) pointed out the abrasion of wasting parts of vehicles. Based on threshold levels presented in sediment quality guidelines (SQGs), in most cases, PAHs were at low levels with occasional negative biological effects on organisms. Only sediments deposited in two RTs located on the Oliwski Stream presented harmful features for sediment-dwelling organisms. The risk assessment performed accordingly to the Σ16PAHs presented a moderate and high risk for biota. This study not only reflects the direct threat related to PAH content in bottom sediments, but also highlights the overall pollution of an area, considered to be a recreational part of the city (Oliwski Stream catchment). The findings of this study highlight the need to launch preventative methods to protect the area against pollution from heating system emission and traffic.

  • A Multifunctional Microwave Filter/Sensor Component Using a Split Ring Resonator Loaded Transmission Line
    • Zahra Shaterian
    • Michał Mrozowski
    2023 Pełny tekst IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS

    This research is focused on the design and realiza2 tion of a microwave component with multifunctional filter/sensor 3 operation using a resonator-loaded transmission line (TL). It is 4 shown that while the structure acts as a bandstop filter, the 5 phase of the reflection coefficient from the loading resonator(s) 6 on a movable layer can be used for displacement sensing, thus 7 allowing for combining filtering with sensing in one device. 8 The proposed multifunctional mechanism is validated through 9 electromagnetic (EM) simulation of the structure. The concept 10 and the performance of the proposed device are further examined 11 through the fabrication and measurement of a multifunctional 12 filter/sensor component based on a microstrip TL loaded with 13 movable split ring resonators (SRRs).