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Politechniki Gdańskiej

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  • Reviewing the recent developments of using graphene-based nanosized materials in membrane separations
    • Roberto Castro-Muñoz
    • Angélica Cruz-Cruz
    • Yrenka Alfaro-Sommers
    • Luisa Ximena Aranda-Jarillo
    • Emilia Gontarek-Castro
    2021 CRITICAL REVIEWS IN ENVIRONMENTAL SCIENCE AND TECHNOLOGY

    According to the potentialities of graphene-based materials and their unique physicochemical properties. Such 2D nanomaterials are likely to be the most implemented within the improvement of the selective separations of polymer membranes, together with enhanced physicochemical properties (such as hydrophilicity/hydrophobicity, transport of molecules, mechanical and thermal features, among others). Hence, this review compiles and analyzes the latest development works (over the last 5 years) for combining graphene materials (including graphene oxide, reduced graphene oxide, etc.) in polymer phases at aiming their implementation in different membrane-based technologies. Herein, particular emphasis has been crucially paid to the novel studies together with relevant findings in the field. Based on the most important insights, the concluding remarks are given with compelling recommendations to the new researchers at exploring graphene materials in membrane separations.

  • Revitalization of Residential Buildings Dating Back to the Late19th and Early 20th Century on the Example of “Willa Halina” in Sopot (Poland)
    • Antoni Taraszkiewicz
    2021 Pełny tekst Buildings

    Residential buildings dating back to the late 19th and early 20th century constitute an important element of the urban composition of many European cities, often determining their overall spatial expression. These buildings often require revitalization and sometimes also reconstruction or extension. Such activities make it possible to restore historical buildings to their former glory, but also to create new architecture, inscribed in the context of the place, yet bearing witness to modern times. Revitalization of historically and architecturally valuable but technically degraded residential buildings is one of the important elements of maintaining and sometimes rebuilding the image of modern cities and their sustainable development. However, revitalization activities require solving many problems of conservational nature, especially issues related to preserving the authenticity of the existing tissue, ways of reconstructing lost elements, and connecting historical architecture with contemporary architecture. Historic residential buildings of Sopot, a city located in Poland on the shores of the Baltic Sea, dating back to the late 19th and early 20th century, provide excellent research material for such considerations. In the article, the historical center of Sopot was examined, with particular emphasis on the historic Willa Halina from 1896 located there, which was revitalized (according to the design of the author of the article). Using such research methods as analysis of historical source material (iconography), observation (operationalization of preserved historical objects), comparative analysis of contemporary investments, and analysis of the revitalization design of “Willa Halina”, an attempt was made to present spatial and technical solutions leading to the desired effects in the revitalization process. This work aims to show (on the example of Willa Halina in Sopot) the author’s method of revitalizing valuable, historical residential buildings, complying with international conservation standards, including the Venice Charter, adopted in 1964 by the Second International Congress of Architects and Technicians of Historical Monuments. The paper also aims to present spatial and technical solutions leading to desired effects in the revitalization process, consistent with the idea of sustainable development.

  • Rewitalizacja posadzek betonowych typu lastrico w obiektach zabytkowych. Część 1
    • Sylwia Świątek-Żołyńska
    • Maciej Niedostatkiewicz
    • Władysław Ryżyński
    2021 Pełny tekst Builder

    W artykule przedstawiono zagadnienia materiałowe i technologiczne dotyczące posadzek typu lastrico w aspekcie oceny ich stanu technicznegooraz sposobów naprawy i rewitalizacji.

  • Rewitalizacja posadzek betonowych typu lastrico w obiektach zabytkowych. Część 2
    • Sylwia Świątek-Żołyńska
    • Maciej Niedostatkiewicz
    • Władysław Ryżyński
    2021 Pełny tekst Builder

    W artykule przedstawiono zagadnienia materiałowe i technologiczne dotyczące posadzek typu lastrico w aspekcie oceny ich stanu technicznego oraz sposobów naprawy i rewitalizacji. Tekst stanowi kontynuacje artykułu zamieszczonego w Builder Science3 nr 9/2021

  • Ring Opening of Triflates Derived from Benzophospholan-3-one Oxides by Aryl Grignard Reagents as a Route to 2‑Ethynylphenyl(diaryl)phosphine Oxides
    • Łukasz Ponikiewski
    • Sylwia Sowa
    2021 Pełny tekst JOURNAL OF ORGANIC CHEMISTRY

    A new simple method for the synthesis of 2-ethynylphenyl(diaryl)phosphine oxides via ring opening of benzophosphol-3-yl triflates has been developed. This process occurs via nucleophilic attack of a Grignard reagent at the phosphorus center, which results in ring opening and cleavage of a leaving group. The reaction proceeds under mild conditions and, within 15−60 min, leads to a library of previously unavailable 2-ethynylphenylphosphine oxides in yields up to 98%.

  • Risk Analysis by a Probabilistic Model of the Measurement Process
    • Wojciech Toczek
    • Janusz Smulko
    2021 Pełny tekst SENSORS

    The aim of the article is presentation of the testing methodology and results of examination the probabilistic model of the measurement process. The case study concerns the determination of the risk of an incorrect decision in the assessment of the compliance of products by measurement. Measurand is characterized by the generalized Rayleigh distribution. The model of the meas-urement process was tested in parallel mode by six risk metrics. An undesirable effect in the re-construction building block of the model was detected, consisting in the distortion of probability distribution at the edges of the measuring range. The paper gives guidelines on how to use the model, to obtain the analytical risk assessment consistent with the results of the Monte Carlo method. The study can be useful in product quality control, test design, and fault diagnosis.

  • Risk assessment for tram traffic on tramway bridges
    • Kazimierz Jamroz
    • Sławomir Grulkowski
    • Krystian Birr
    • Łukasz Jeliński
    • Marcin Budzyński
    2021 Pełny tekst Archives of Civil Engineering

    Miejski transport szynowy wielu miastach stanowi istotny element systemu transportowego i jest przestrzennie rozwijającym się systemem zapewniającym mieszkańcom codzienną obsługę transportową. Bezpieczeństwo pasażerów transportu szynowego i użytkowników dróg jest jednym z najważniejszych czynników, który należy uwzględnić w trakcie projektowania infrastruktury oraz w ocenie operacyjnej systemu miejskiego transportu tramwajowego. Jedną z nierozwiązanych kwestii funkcjonowania transportu tramwajowego są odcinki dróg tramwajowych o dużych pochyleniach podłużnych. W artykule przedstawiono próbę zastosowania metody zarządzania ryzkiem do oceny bezpieczeństwa funkcjonowania dróg tramwajowych na obiektach zlokalizowanych na odcinkach dróg o dużych pochyleniach podłużnych. Taki problem występuje na trasie tramwajowej w Gdańsku przebiegającej na ulicy (częściowo na estakadzie) o pochyleniu położonej powyżej 5 % i małym łuku poziomym. Do oceny ryzyka zastosowano metodę zarządzania ryzykiem w transporcie TRANS-RISK. W pierwszym etapie przeprowadzono analizę ryzyka zagrożeń, korzystając z metod Bow-Tie i drzewa błędów zidentyfikowano główne zagrożenia poważnymi wypadkami na analizowanym odcinku drogi tramwajowej. Do oceny ryzyka zastosowano trzy podejścia oceniając ryzyko: indywidualne, społeczne i kolektywne. To ostatnie, nie używane w tego typu ocenach miejskiej infrastruktury transportowej, okazało się najbardziej przydatne do oceny bezpieczeństwa analizowanej infrastruktury. Wyniki przeprowadzonych analiz i ocen pozwoliły na sformułowanie zasad projektowania i utrzymania obiektów infrastruktury tramwajowej położonej na odcinkach o dużych pochyleniach.

  • ROAD SAFETY FOR CYCLISTS BASED ON THE CALORIES NEEDED
    • Gaetano Bosurgi
    • Orazio Pellegrino
    • Joanna Wachnicka
    • Romanika Okraszewska
    2021 Pełny tekst Transport Problems

    Cyclists are a vulnerable group of road users, especially when no separate infrastructure for cyclists is provided. Then, road factors such as distance and altitude differences can indirectly affect cyclists' safety. Therefore, the authors proposed a procedure based on the geometric characteristics of the road that can determine riding difficulties for cyclists. The proposed procedure can be used both by the public authorities who manage cyclists' safety and as a method of classifying the road network for cycling. The proposed procedure, based on the use of pattern recognition techniques, analyses data from a sample of nine riders who travelled on rural roads within the Municipality of Messina (Italy) to classify the roads according to their cycling difficulty. For each rider, duration, distance, road slope, altitude difference and spent calories have been measured and analysed. The collected data were used for the development of a model capable of predicting the cyclist’s physical effort as a function of the road alignment itself. Knowing the effort required to cycle along a route can contribute to a more complete assessment of road classification, commonly defined according to motor vehicles. Moreover, it may constitute a measure determining the safety of cycling by encouraging cyclists to travel along roads compatible with their physical abilities.

  • Roadmap on dynamics of molecules and clusters in the gas phase
    • Henning Zettergren
    • Alicja Domaracka
    • Thomas Schlathölter
    • Paola Bolognesi
    • Sergio Díaz-Tendero
    • Marta Łabuda
    • Sanja Tosic
    • Sylvain Maclot
    • Per Johnsson
    • Amanda Steber
    • Denis Tikhonov
    • Mattea Carmen Castrovilli
    • Lorenzo Avaldi
    • Sadia Bari
    • Aleksandar Milosavljević
    • Alicia Palacios
    • Shirin Faraji
    • Dariusz G. Piekarski
    • Patrick Rousseau
    • Daniela Ascenzi
    • Claire Romanzin
    • Ewa Erdmann
    • Manuel Alcamí
    • Janina Kopyra
    • Paulo Limão-Vieira
    • Jaroslav Kočišek
    • Juraj Fedor
    • Simon Albertini
    • Michael Gatchell
    • Henrik Cederquist
    • Henning T. Schmidt
    • Elisabeth Gruber
    • Lars H. Andersen
    • Oded Heber
    • Yoni Toker
    • Klavs Hansen
    • Jennifer A. Noble
    • Christophe Jouvet
    • Christina Kjær
    • Steen Nielsen
    • Eduardo Carrascosa
    • James Bull
    • Alessandra Candian
    • Annemieke Petrignani
    2021 Pełny tekst EUROPEAN PHYSICAL JOURNAL D

    This roadmap article highlights recent advances, challenges and future prospects in studies of the dynamics of molecules and clusters in the gas phase. It comprises nineteen contributions by scientists with leading expertise in complementary experimental and theoretical techniques to probe the dynamics on timescales spanning twenty orders of magnitudes, from attoseconds to minutes and beyond, and for systems ranging in complexity from the smallest (diatomic) molecules to clusters and nanoparticles. Combining some of these techniques open up new avenues to unravel hitherto unexplored reaction pathways and mechanisms, and to establish their significance in, e.g. radiotherapy and radiation damage on the nanoscale, astrophysics, astrochemistry, and atmospheric science.

  • Robot-Based Intervention for Children With Autism Spectrum Disorder: A Systematic Literature Review
    • Katrin D. Bartl-Pokorny
    • Pinar Uluer
    • Duygun Erol Barkana
    • Alice Baird
    • Hatice Kose
    • Tatjana Zorcec
    • Ben Robins
    • Bjorn Schuller
    • Agnieszka Landowska
    • Małgorzata Pykała
    2021 Pełny tekst IEEE Access

    Children with autism spectrum disorder (ASD) have deficits in the socio-communicative domain and frequently face severe difficulties in the recognition and expression of emotions. Existing literature suggested that children with ASD benefit from robot-based interventions. However, studies varied considerably in participant characteristics, applied robots, and trained skills. Here, we reviewed robot-based interventions targeting emotion-related skills for children with ASD following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. We systematically searched for all relevant articles published in English language until May 2021, using the databases Scopus, Web of Science, and PubMed. From a total of 609 identified papers, 60 publications including 50 original articles and 10 non-empirical articles including review articles and theoretical articles were eligible for the synthesis. A total of 892 participants were included in the robot-based intervention studies; 570 of them were children with ASD. Nao and ZECA were the most frequently used robots; recognition of basic emotions and getting into interaction were the most frequently trained skills, while happiness, sadness, fear, and anger were the most frequently trained emotions. The studies reported a wide range of challenges with respect to robot-based intervention, ranging from limitations for certain ASD subgroups and security aspects of the robots to efforts regarding the automatic recognition of the children’s emotional state by the robotic systems. Finally, we summarised and discussed recommendations regarding the application of robot-based interventions for children with ASD.

  • Robust Parameter Tuning of Antenna Structures by Means of Design Specification Adaptation
    • Sławomir Kozieł
    • Wacław Pietrenko
    2021 Pełny tekst IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION

    Parameter tuning through numerical optimization has become instrumental in the design of high-performance antenna systems. Yet, practical optimization faces several major challenges, including high cost of massive evaluations of antenna characteristics, normally involving full-wave electromagnetic (EM) analysis, large numbers of adjustable variables, the shortage of reasonable initial solutions in the case of topologically complex structures, and multimodality of the objective function landscapes. The last two reasons foster the employment of global search routines, which might be prohibitively expensive. This paper proposes a novel procedure for efficient and reliable antenna optimization by means of design specification adaptation. By using appropriate selection criteria and the predictions from a linear expansion model, the ability of improving the current design is verified, and—in the case of a negative outcome—performance requirements are relaxed temporarily. The adjustment is carried out before each iteration of the optimization process with the specifications eventually converging to their original levels. The algorithm is intended to improve the efficacy of local optimizers if the target operating frequencies of the structure at hand are severely misaligned with respect to those at the available initial design. This eliminates the need for global routines, and greatly enhances the robustness of the search process, as demonstrated using several antenna structures optimized under different scenarios.

  • Robust-adaptive dynamic programming-based time-delay control of autonomous ships under stochastic disturbances using an actor-critic learning algorithm
    • Hossein Nejatbakhsh Esfahani
    • Rafał Szłapczyński
    2021 Pełny tekst JOURNAL OF MARINE SCIENCE AND TECHNOLOGY

    This paper proposes a hybrid robust-adaptive learning-based control scheme based on Approximate Dynamic Programming (ADP) for the tracking control of autonomous ship maneuvering. We adopt a Time-Delay Control (TDC) approach, which is known as a simple, practical, model free and roughly robust strategy, combined with an Actor-Critic Approximate Dynamic Programming (ACADP) algorithm as an adaptive part in the proposed hybrid control algorithm. Based on this integration, Actor-Critic Time-Delay Control (AC-TDC) is proposed. It offers a high-performance robust-adaptive control approach for path following of autonomous ships under deterministic and stochastic disturbances induced by the winds, waves, and ocean currents. Computer simulations have been conducted under two different conditions in terms of the deterministic and stochastic disturbances and all simulation results indicate an acceptable performance in tracking of paths for the proposed control algorithm in comparison with the conventional TDC approach.

  • Robustness Analysis of a Distributed MPC Control System of a Turbo-Generator Set of a Nuclear Plant – Disturbance Issues
    • Paweł Sokólski
    • Tomasz Rutkowski
    • Bartosz Ceran
    • Dariusz Horla
    2021 Pełny tekst Advances in Intelligent Systems and Computing

    Typically, there are two main control loops with PI controllers operating at each turbo-generator set. In this paper, a distributed model predictive controller with local quadratic model predictive controllers for the turbine generator is proposed instead of a set of classical PI controllers. The local quadratic predictive controllers utilize step-response models for the controlled system components. The parameters of these models are determined based on the proposed black-box models of the turbine and synchronous generator, which parameters are identified on-line with the recursive least-squares algorithm. A robustness analysis of the control system with respect to different disturbances is presented in the paper. There are various configurations considered, such as change in disturbance levels from the side of electrical and thermal systems, or changes in prediction horizons.

  • Robustness in Compressed Neural Networks for Object Detection
    • Sebastian Cygert
    • Andrzej Czyżewski
    2021 Pełny tekst

    Model compression techniques allow to significantly reduce the computational cost associated with data processing by deep neural networks with only a minor decrease in average accuracy. Simultaneously, reducing the model size may have a large effect on noisy cases or objects belonging to less frequent classes. It is a crucial problem from the perspective of the models' safety, especially for object detection in the autonomous driving setting, which is considered in this work. It was shown in the paper that the sensitivity of compressed models to different distortion types is nuanced, and some of the corruptions are heavily impacted by the compression methods (i.e., additive noise), while others (blur effect) are only slightly affected. A common way to improve the robustness of models is to use data augmentation, which was confirmed to positively affect models' robustness, also for highly compressed models. It was further shown that while data imbalance methods brought only a slight increase in accuracy for the baseline model (without compression), the impact was more striking at higher compression rates for the structured pruning. Finally, methods for handling data imbalance brought a significant improvement of the pruned models' worst-detected class accuracy.

  • Rola i techniki eksploracji w uczeniu przez wzmacnianie
    • Piotr Januszewski
    2021

    W rozdziale podjęto rozważania na temat roli eksploracji w uczeniu się agentów sztucznej inteligencji przez wzmacnianie. Prezentuje przegląd współczesnych technik eksploracji i rozróżnia dwie główne rodziny technik: eksplorację nieukierunkowaną i eksplorację ukierunkowaną. Praca ta powinna pomóc zrozumieć dylemat pomiędzy eksploatacją wiedzy a eksploracją środowiska, któremu poddany jest agent w każdym kroku interakcji ze środowiskiem. Opisane tutaj techniki mogą być inspiracją do dalszych prac nad rozwiązaniem tego dylematu i tym samym ulepszenia metod uczenia się przez wzmacnianie.

  • Role of cholesterol in substrate recognition by -secretase
    • Łukasz Nierzwicki
    • Michał Olewniczak
    • Paweł Chodnicki
    • Jacek Czub
    2021 Pełny tekst Scientific Reports

    -Secretase is an enzyme known to cleave multiple substrates within their transmembrane domains, with the amyloid precursor protein of Alzheimer’s Disease among the most prominent examples. The activity of -secretase strictly depends on the membrane cholesterol content, yet the mechanistic role of cholesterol in the substrate binding and cleavage remains unclear. In this work, we used all-atom molecular dynamics simulations to examine the role of cholesterol in the initial binding of a direct precursor of -amyloid polypeptides by -secretase. We showed that in cholesterol-rich membranes, both the substrate and the enzyme region proximal to the active site induce a local membrane thinning. With the free energy methods we found that in the presence of cholesterol the substrate binds favorably to the identified exosite, while cholesterol depletion completely abolishes the binding. To explain these findings, we directly examined the role of hydrophobic mismatch in the substrate binding to -secretase, showing that increased membrane thickness results in higher propensity of the enzyme to bind substrates. Therefore, we propose that cholesterol promotes substrate binding to -secretase by increasing the membrane thickness, which leads to the negative hydrophobic mismatch between the membrane and binding partners.

  • Room temperature depinning of the charge-density waves in quasi-two-dimensional 1T-TaS2 devices
    • A. Mohammadzadeh
    • A. Rehman
    • F. Kargar
    • S. Rumyantsev
    • Janusz Smulko
    • W. Knap
    • R. K. Lake
    • A. A. Balandin
    2021 Pełny tekst APPLIED PHYSICS LETTERS

    We report on the depinning of nearly commensurate charge-density waves in 1T-TaS2 thin films at room temperature. A combination of the differential current–voltage measurements with the low-frequency noise spectroscopy provides unambiguous means for detecting the depinning threshold field in quasi-2D materials. The depinning process in 1T-TaS2 is not accompanied by an observable abrupt increase in electric current—in striking contrast to depinning in the conventional charge-density-wave materials with quasi-1D crystal structure. We explained it by the fact that the current density from the charge-density waves in the 1T-TaS2 devices is orders of magnitude smaller than the current density of the free carriers available in the discommensuration network surrounding the commensurate charge-density wave islands. The depinning fields in 1T-TaS2 thin-film devices are several orders of magnitude larger than those in quasi-1D van der Waals materials. Obtained results are important for the proposed applications of the charge-density wave devices in electronics.

  • Rozwój systemu finansowego Polski w gospodarce globalnej
    • Karolina Tura-Gawron
    • Adam Marszk
    2021

    Temat niniejszej monografii to powstanie oraz rozwój systemu finansowego w Polsce od rozpoczęcia transformacji ustrojowej, ze szczególnym uwzględnieniem miejsca Polski w globalnej gospodarce. Istotną częścią monografii są przesłanki i wytyczne dotyczące możliwych przyszłych rozwiązań oraz kierunków ewolucji polskiego systemu finansowego, wyprowadzone na podstawie wykonanych przez autorów badań i analiz polskiej/ globalnej gospodarki. Cele główne monografii: - przedstawienie oraz ocena zmian, które zaszły w polskim systemie finansowym po 1989 roku, od kiedy Polska stała się w pełni częścią globalnej gospodarki; - określenie kierunków, w których podąża lub powinien podążać system finansowy w Polsce w warunkach postępującej globalizacji w XXI wieku. Zakres czasowy monografii obejmuje okres po rozpoczęciu transformacji gospodarczej w Polsce, tj. lata 1989–2018 (w niektórych rozdziałach zakres ten jest krótszy lub dłuższy ze względu na dostępność danych lub poruszane zagadnienie), a przedmiotem badania są system finansowy w Polsce oraz – dla celów porównawczych – systemy finansowe w innych wybranych krajach (głównie europejskich). W kolejnych rozdziałach omówione zostały zagadnienia teoretyczne, rezultaty badań (w tym przeprowadzonych przez autorów) oraz płynące z nich wnioski. Część pierwsza opracowania, Polityka monetarna w Polsce – od transformacji do globalizacji, obejmuje cztery rozdziały dotyczące prowadzenia polityki w warunkach niepewności, inflacji, strategii polityki monetarnej oraz problemów współczesnej polityki monetarnej. Wybrane zagadnienia pokazują bezpośrednio ewolucję polskiej bankowości centralnej, ze szczególnym uwzględnieniem zastosowanych rozwiązań operacyjno-instytucjonalnych. Klamrą scalającą i tematyką wiodącą tej części jest wdrażanie przez Narodowy Bank Polski (NBP) strategii bezpośredniego celu inflacyjnego (BCI). Część druga monografii, Rynek kapitałowy i stabilność polskiego systemu finansowego – perspektywa lokalna i globalna, stanowi, symetryczny w stosunku do poprzedniego, zbiór czterech rozdziałów na temat historii i roli polskiego rynku kapitałowego, innowacji w systemie finansowym oraz stabilności polskiego systemu finansowego. Zakończenie zawiera wnioski z rozważań o charakterze teoretycznym oraz empirycznym, przedstawionych w obu częściach pracy.

  • Różnica w subiektywnej ocenie jakości mowy pomiędzy nastolatkami dwujęzycznymi a jednojęzycznymi
    • Przemysław Falkowski-Gilski
    • Stefan Brachmański
    • Maurycy Kin
    • Andrzej Dobrucki
    2021

    Proces percepcji mowy omawiany jest w szerokim zakresie dziedzin i dyscyplin naukowych, od nauk humanistycznych, technicznych, aż po nauki medyczne. Wiele badań skupia się np. na ocenie różnicy w grupach bez i z wykształceniem muzycznym. Skoro stwierdzono, że zdolności muzyczne wpływają na percepcję poszczególnych atrybutów dźwięku, autorzy postanowili zbadać, czy zdolności językowe także mogą mieć wpływ na ocenę jakości sygnału mowy. W pracy przedstawiono różnicę w postrzeganiu sygnałów mowy pomiędzy młodzieżą szkolną z klas dwujęzycznych i jednojęzycznych. Badania obejmowały grupę 30 uczestników, po 15 osób w każdej klasie, w wieku 16-18 lat. Próbki mowy składały się z 3 zbiorów: angielski amerykański, angielski brytyjski i polski. Otrzymane wyniki mogą stanowić cenną wskazówkę zarówno dla naukowców jak i nauczycieli w szkolnictwie podstawowym, średnim oraz wyższym, a także inżynierów projektujących usługi i dostarczających treści.

  • Rubrene Thin Films with Viably Enhanced Charge Transport Fabricated by Cryo-Matrix-Assisted Laser Evaporation
    • Rafał Jendrzejewski
    • Natalia Majewska
    • Sayani Majumdar
    • Sawczak Mirosław
    • Jacek Ryl
    • Gerard Śliwiński
    2021 Pełny tekst Materials

    Among organic semiconductors, rubrene (RB; C42H28) is of rapidly growing interest for the development of organic and hybrid electronics due to exceptionally long spin diffusion length and carrier mobility up to 20 cm2V−1s−1 in single crystals. However, the fabrication of RB thin films resembling properties of the bulk remains challenging, mainly because of the RB molecule’s twisted conformation. This hinders the formation of orthorhombic crystals with strong π–π interactions that support the band transport. In this work, RB films with a high crystalline content were fabricated by matrix-assisted laser evaporation and the associated structure, composition, and transport properties are investigated. Enhanced charge transport is ascribed to the crystalline content of the film. Spherulitic structures are observed on top of an amorphous RB layer formed in the initial deposition stage. In spherulites, orthorhombic crystals dominate, as confirmed by X-ray diffraction and the absorption and Raman spectra. Surprisingly, nanowires several microns in length are also detected. The desorption/ionization mass and X-ray photoelectron spectra consistently show minimal material decomposition and absence of RB peroxides. The observed carrier mobility up to 0.13 cm2V−1s−1, is close to the technologically accepted level, making these rubrene films attractive for spintronic and optoelectronic applications

  • Rynek pracy w Azerbejdżanie, Armenii i Gruzji
    • Krystyna Gomółka
    2021

    Praca ukazuje zmiany na rynku pracy w trzech państwach Kaukazu Południowego w latach 2000-2020

  • RYNEK PRACY w dobie pandemii COVID-19 na przykładzie Azerbejdżanu i Polski
    • Krystyna Gomółka
    • Marzena Kacprzak
    • Dorota Kmieć
    • Agnieszka Król
    • Janusz Majewski
    2021

    Nieoczekiwane pojawienie się pandemii COVID-19 spowodowało prawdziwą rewolucję w wielu sektorach gospodarek na całym świecie. Jedne z nich dotknięte zostały bardziej niż inne, a z kolei niektóre, jak na przykład branża e-commerce, kurierska, EdTech – edukacja online, przeżywały wręcz prawdziwy rozkwit. W zasadzie można powiedzieć, że każde państwo odczuwa skutki pandemii, zwłaszcza te negatywne, choć oczywiście uwarunkowane jest to wieloma różnymi czynnikami. Kryzys nie ominął też rynków pracy na całym świecie. Panująca na nich sytuacja w dość dużym stopniu uzależniona jest od ich kondycji z czasów sprzed pandemii, a także efektywności mechanizmów, zwłaszcza w kontekście adaptacji i funkcjonowania w turbulentnym otoczeniu. Polityka rynku pracy w poszczególnych krajach stanęła przed trudnym zadaniem, jakim jest konieczność wdrażania rozwiązań, często innowacyjnych, które pomogą zapobiec wzrastającej stopie bezrobocia oraz zapewnić równowagę w obszarze popytu i podaży pracowników, uwzględniając kształtujący się nowy profil kompetencyjny pracowników na rynku pandemicznym, a także w niedalekiej przyszłości popandemicznej. Autorzy niniejszej monografii podjęli próbę identyfikacji kluczowych trendów i zjawisk na dotkniętych skutkami pandemii rynkach pracy, ze szczególnym uwzględnieniem sytuacji panującej w Azerbejdżanie i Polsce. Analizę rynku pracy oparto na wynikach własnych badań empirycznych. Cele szczegółowe pracy dotyczyły m.in. charakterystyki rynków pracy w Azerbejdżanie i Polsce; określenia sytuacji różnych grup społecznych (kobiet, pracowników 50+, młodych pracowników) na rynku pracy w okresie kryzysu; identyfikacji sytuacji na rynku pracy osób zatrudnionych w korporacjach i MSP w kontekście pandemii COVID-19.

  • Safeguarding democracy during pandemics. Social distancing, postal, or internet voting—the good, the bad, or the ugly?
    • Robert Krimmer
    • David Duenas Cid
    • Iuliia Krivonosova
    2021 Pełny tekst PUBLIC MONEY & MANAGEMENT

    During a pandemic, many countries and organizations must decide whether to postpone upcoming elections or to hold them (Krimmer et al., 2020a). If the decision is made to hold the election, three main scenarios come to mind: continue using the existing system but include measures to ensure the health of participants; or look for alternatives among remote voting channels which could ensure social distancing is guaranteed either by postal voting, or internet voting.

  • Safety and Functionality Assessment of Tram Loops in Wrocław
    • Agnieszka Tubis
    • Mateusz Rydlewski
    • Marcin Budzyński
    2021 Pełny tekst Journal of KONBiN

    The article presents the implementation of the ISFTL method proposed by the authors consisting in an indicator assessment of the safety and functionality of tram loops. Five tram loops located in Wrocław were analyzed. Each of these loops has different characteristics. The components of each assessment are described in detail and further directions for improving the proposed assessment are indicated.

  • Safety at railway level crossings and Vision Zero
    • Eligiusz Mieloszyk
    • Anita Milewska
    • Sławomir Grulkowski
    2021 Pełny tekst Archives of Civil Engineering

    In this work, safety analysis at the railway level crossings is presented using advanced mathematical modelling. Resistivity of track subgrade panels is taken into account. The analysis does not refer to the assessment of the current regulations. Specific cases of generalized dynamic system are considered by introducing operations S=Δ, S=P defined in space C(N) of real sequences. In this model, generalized discrete exponential and trigonometric functions that reflect the oscillatory nature of the analysed quantities are used. The advantage of the analyzes is the avoidance of numerical errors. We show also the importance of the resistivity of track subgrade panels in safety at the level crossings. The safety at the level crossings can be increased through providing track subgrade panels with appropriate resistivity to minimize negative effect of stray currents. The results may be used to evaluate selected safety indicators as well as to predict safety levels and to determine the ways of improving safety.

  • Samorządy i nauka
    • Piotr Wojtulek
    • Justyna Płotka-Wasylka
    2021 Pełny tekst Forum Akademickie

    inansowanie nauki w Polsce powinno dążyć do modelu, w którym są trzy źródła funduszy dla nauki: budżet centralny, budżety samorządów terytorialnych oraz przedsiębiorców. Obecnie zwłaszcza trzecie ze źródeł jest relatywnie słabo zaangażowane w rozwój nauki, być może jest to związane częściowo ze zbytnią dominacją budżetu centralnego w finansowaniu naszej nauki. Z kolei dla samorządów wojewódzkich inwestycje w uczelnie powinny być jednym ze sposobów budowania wysokiej pozycji regionów.

  • Sample Preparation in Foodomics: Miniaturized Solid-Phase Extraction
    • Dorota Garwolińska
    • Renata Marcinkowska
    • Jacek Namieśnik
    • Weronika Hewelt-Belka
    2021

    Analytical chemists face a challenge to bring comprehensive information on a given food and biological sample by using the best available analytical techniques and meet the requirements of sustainable development and green chemistry at the same time. A key objective of this chapter is to review selected literature data on the utilization of solid-phase extraction techniques with special attention to their miniaturized modes in order to assess the safety, quality and nutritional value of foods. The techniques will be discussed in the context of different samples and analytical information which is about to be obtained.

  • Satellite Image Classification Using a Hierarchical Ensemble Learning and Correlation Coefficient-Based Gravitational Search Algorithm
    • Kowsalya Thiagarajan
    • Mukunthan Manapakkam Anandan
    • Andrzej Stateczny
    • Parameshachari Bidare Divakarachari
    • Hemalatha Kivudujogappa Lingappa
    2021 Pełny tekst Remote Sensing

    Satellite image classification is widely used in various real-time applications, such as the military, geospatial surveys, surveillance and environmental monitoring. Therefore, the effective classification of satellite images is required to improve classification accuracy. In this paper, the combination of Hierarchical Framework and Ensemble Learning (HFEL) and optimal feature selection is proposed for the precise identification of satellite images. The HFEL uses three different types of Convolutional Neural Networks (CNN), namely AlexNet, LeNet-5 and a residual network (ResNet), to extract the appropriate features from images of the hierarchical framework. Additionally, the optimal features from the feature set are extracted using the Correlation Coefficient-Based Gravitational Search Algorithm (CCGSA). Further, the Multi Support Vector Machine (MSVM) is used to classify the satellite images by extracted features from the fully connected layers of the CNN and selected features of the CCGSA. Hence, the combination of HFEL and CCGSA is used to obtain the precise classification over different datasets such as the SAT-4, SAT-6 and Eurosat datasets. The performance of the proposed HFEL–CCGSA is analyzed in terms of accuracy, precision and recall. The experimental results show that the HFEL–CCGSA method provides effective classification over the satellite images. The classification accuracy of the HFEL–CCGSA method is 99.99%, which is high when compared to AlexNet, LeNet-5 and ResNet.

  • Scaling Up the Process of Titanium Dioxide Nanotube Synthesis and Its Effect on Photoelectrochemical Properties
    • Mariusz Szkoda
    • Konrad Trzciński
    • Zuzanna Zarach
    • Daria Roda
    • Marcin Łapiński
    • Andrzej Nowak
    2021 Pełny tekst Materials

    In this work, for the first time, the influence of scaling up the process of titanium dioxide nanotube (TiO2NT) synthesis on the photoelectrochemical properties of TiO2 nanotubes is presented. Titanium dioxide nanotubes were obtained on substrates of various sizes: 2 × 2, 4 × 4, 5 × 5, 6 × 6, and 8 × 8 cm2. The electrode material was characterized using scanning electron microscopy as well as Raman and UV–vis spectroscopy in order to investigate their morphology, crystallinity, and absorbance ability, respectively. The obtained electrodes were used as photoanodes for the photoelectrochemical water splitting. The surface analysis was performed, and photocurrent values were determined depending on their place on the sample. Interestingly, the values of the obtained photocurrent densities in the center of each sample were similar and were about 80 µA·cm2. The results of our work show evidence of a significant contribution to wider applications of materials based on TiO2 nanotubes not only in photoelectrochemistry but also in medicine, supercapacitors, and sensors

  • Scheduling of compatible jobs on parallel machines
    • Tytus Pikies
    2021

    The dissertation discusses the problems of scheduling compatible jobs on parallel machines. Some jobs are incompatible, which is modeled as a binary relation on the set of jobs; the relation is often modeled by an incompatibility graph. We consider two models of machines. The first model, more emphasized in the thesis, is a classical model of scheduling, where each machine does one job at time. The second one is a model of p-batching machines, where a machine can do many jobs at once. Precisely, the jobs have to be grouped into batches and the batches assigned to machines. In the case of the first model, no two jobs that are incompatible can be scheduled on the same machine. In the case of the second one, no two jobs that are incompatible can be scheduled in the same batch. The work analyzes problems of the scheduling with respect to two criteria of optimality, maximum completion time among the jobs and total completion time of jobs. We analyze the problem with the following types of machines: identical, uniform and unrelated. We provide further results for makespan criterion, which is quite commonly considered in the setting of classical machines. More importantly, we provide results for many classes of graphs with respect to the total completion time criterion, which has not been considered in the literature before for the classical machines in the considered setting. In particular, we provide polynomial time algorithms for identical machines; and complete partite graphs or cluster graphs. Also, for complete partite graphs and uniform machines we apply the techniques of rounding, partial exhaustive search, and linear programming to obtain 4-approximate algorithm. The algorithm demonstrates that an application of the techniques to the problems with total completion time criteria is feasible. Finally, there is presented a study of the cost coloring problem, which has direct implications for uniform p-batching machines. Hence, we also briefly consider uniform p-batching machines and weighted total completion time criterion, which is a generalization of total completion time. The study starts with an overview of recent advances in the scheduling algorithms in the context of scheduling incompatible jobs. After the overview, the results presented are: polynomial time algorithms; approximate algorithms with constant approximation ratio; inapproximability results up to some constant, and up to arbitrary constant.

  • Scheduling with Complete Multipartite Incompatibility Graph on Parallel Machines
    • Tytus Pikies
    • Krzysztof Turowski
    • Marek Kubale
    2021

    In this paper we consider a problem of job scheduling on parallel machines with a presence of incompatibilities between jobs. The incompatibility relation can be modeled as a complete multipartite graph in which each edge denotes a pair of jobs that cannot be scheduled on the same machine. Our research stems from the works of Bodlaender, Jansen, and Woeginger (1994) and Bodlaender and Jansen (1993). In particular, we pursue the line investigated recently by Mallek, Bendraouche, and Boudhar (2019). We provide several results concerning schedules, optimal or approximate with respect to the two most popular criteria of optimality: Cmax (makespan) and ΣCj (total completion time). We consider a variety of machine types in our paper: identical, uniform, and unrelated. Our results consist of delimitation of the easy (polynomial) and NP-hard problems within these constraints. We also provide algorithms, either polynomial exact algorithms for the easier problems, or algorithms with a guaranteed constant worst-case approximation ratio. In particular, we fill the gap on research for the problem of finding a schedule with the smallest ΣCj on uniform machines. We address this problem by developing a linear programming relaxation technique with an appropriate rounding, which to our knowledge is a novelty for this criterion in the considered setting.

  • Scheelite-Type Wide-Bandgap ABO4 Compounds (A = Ca, Sr, and Ba; B = Mo and W) as Potential Photocatalysts for Water Treatment
    • Marta Kowalkińska
    • Paweł Głuchowski
    • Tomasz Swebocki
    • Tadeusz Ossowski
    • Adam Ostrowski
    • Waldemar Bednarski
    • Jakub Karczewski
    • Anna Zielińska-Jurek
    2021 Pełny tekst Journal of Physical Chemistry C

    In the present study, alkaline-earth metal scheelite-type compounds ABO4 (A = Ca, Sr, Ba, B = Mo, W) synthesized by a hydrothermal method were systematically studied. The as-obtained photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller surface area analysis (BET), UV–Vis diffuse reflectance spectroscopy (DR/UV-Vis), photoluminescence, and thermoluminescence (TL) spectroscopy together with charge carrier’s lifetime measurements, electron paramagnetic resonance spectroscopy (EPR) and electrochemical impedance spectroscopy (EIS). The photocatalytic activity was studied in the reaction of phenol degradation under simulated solar light. The obtained tungstates and molybdates revealed excellent photocatalytic activity despite the low surface area and wide-bandgap typical for insulators. The mechanism of phenol degradation proceeded through hydroquinone and catechol formation in the presence of hydroxyl and superoxide radicals. The presence of electron traps allowed to absorb light with lower energy than resulting from the absorption edge. BaWO4 and SrWO4, with the most extended average carrier lifetime, were the most efficient photocatalysts from obtained series. In general, molybdates exhibited lower photocatalytic activity towards phenol degradation due to deeper trap states and lower average charge carriers' lifetimes than tungstates. Additionally, electrochemical studies emerged that molybdates exhibit more insulating behavior than tungstates. Overall results showed that wide-bandgap semiconductors, mainly tungstates, can be applied as earth-abundant photocatalytic materials for the degradation of persistent organic pollutants.

  • Searching by heterogeneous agents
    • Dariusz Dereniowski
    • Łukasz Kuszner
    • Robert Ostrowski
    2021 JOURNAL OF COMPUTER AND SYSTEM SCIENCES

    In this work we introduce and study a pursuit-evasion game in which the search is performed by heterogeneous entities. We incorporate heterogeneity into the classical edge search problem by considering edge-labeled graphs: once a search strategy initially assigns labels to the searchers, each searcher can be only present on an edge of its own label. We prove that this problem is not monotone even for trees and we give instances in which the number of recontamination events is asymptotically quadratic in the tree size. Other negative results regard the NP-completeness of the monotone, and NP-hardness of an arbitrary (i.e., non-monotone) heterogeneous search in trees. These properties show that this problem behaves very differently from the classical edge search. On the other hand, if all edges of a particular label form a (connected) subtree of the input tree, then we show that optimal heterogeneous search strategy can be computed efficiently.

  • Seasonal and spatial differences in metal and metalloid concentrations in the snow cover of Hansbreen, Svalbard
    • Krystyna Kozioł
    • Aleksander Uszczyk
    • Filip Pawlak
    • Marcin Frankowski
    • Żaneta Polkowska
    2021 Pełny tekst Frontiers in Earth Science

    Metals and metalloids in snow on glaciers, depending on the season of deposition, may come from various sources: local rock dust (erosion of the geological substratum), marine aerosol, local human activity (e.g. fuel combustion, waste incineration) and long-range atmospheric transport. Hansbreen glacier, located close to the Polish Polar Station in Svalbard, is a perfect site to study metals and metalloids: it has complex geological substratum, a year-round presence of a small group of people, and is near the coast. We analysed a snapshot of elemental concentrations in snow samples from shallow cores corresponding to autumn, winter and spring deposition on Hansbreen. Eighteen cores of snow were collected across the glacier, revealing the influence of potential local pollution sources. In these samples, we predominantly found Na, Mg and K, followed by Zn, Ca, Al and Fe. Heavy metals (Bi, Hg) were also detected. Cluster analysis of the determined elemental concentrations divided them into three distinct groups: 1) Ag, As, Bi, Cd, Hg, Mo, Sb, Se and Zn – representing mostly long-range transported volatile elements, with possible extra local geological sources; 2) Al, Fe, Cu and Mn – elements with crustal sources, and 3) Na, Ca, Mg, K and Sr – mainly from sea spray aerosol. Such interpretation was confirmed by the calculation of sea salt contribution based on mean seawater composition. In the study site, snow was up to six times more efficient in bringing metal and metalloid pollution into terrestrial environment, when comparared to rain.

  • Seaweed as a resource for Anaerobic Digestion
    • Iwona Cichowska-Kopczyńska
    • Robert Aranowski
    2021

    Extensive growth of algae contributes to disruptive changes to the water ecosystems. This is mainly caused by redundant nutrients that are washed off the land and end up in waters. Tackling eutrophication by recovery of nutrients can be a solution to the problem. Cast marine biomass can be a resource for renewable energy technologies like anaerobic digestion. Such approach can contribute to the transition to a circular bio-economy and to preserving recreational value of the area.

  • Seaweed utilization issues in biogas production
    • Robert Aranowski
    • Iwona Cichowska-Kopczyńska
    2021

    Macroalgae can be seen as a renewable feedstock for the production of biofuels in many coastal areas around the World and especially in Baltic Sea region where the eutrophication is particularly troublesome. The investigation of anaerobic digestion technologies for extracting inexhaustible bioenergy from seaweed was conducted in many research institutions mainly in laboratory scale. Although seaweeds seem to have a great potential as a feedstock in anaerobic digestion due to high biomass yields and lack of competition with terrestrial plants on limited agricultural land, their potentially high heavy metals content and other impurities (like sand and plastics) creates significant problems for the digestion process, but also for the further use of the digestate. Due to high levels of contaminants, it is not always possible to directly use the cast seaweed as a substrate for biogas production. The micro and macro elements uptake by algae strongly depends on factors as water salinity, characteristics of habitats (e.g. presence of an nearby industrial area or existence of an estuary whose waters might carry additional nutrient loads from urban and agriculture areas). The main limiting factor of a digestate utilisation as an organic fertiliser is the heavy metals concentration but the main process issues during anaerobic digestion are caused by the presence of sand in the feedstock. Collected seaweed biomass (especially from sandy beaches) very often contains sand, which can negatively effect the durability of bioreactors and other biogas plant equipment. Pre-treatment of the collected seaweed is essential for the anaerobic digestion process safety and efficient operation of the biogas plant. Furthermore, different stages of pre-treatment as well as the combination of pre-treatment methods can greatly increase the quality of the methane yield. Present study focuses on pre-treatment methods case reducing sand contents in seaweed feedstock.

  • Secure Italian domination in graphs
    • Magda Dettlaff
    • Magdalena Lemańska
    • Juan A. RODRíGUEZ-VELáZQUEZ
    2021 Pełny tekst JOURNAL OF COMBINATORIAL OPTIMIZATION

    An Italian dominating function (IDF) on a graph G is a function f:V(G)→{0,1,2} such that for every vertex v with f(v)=0, the total weight of f assigned to the neighbours of v is at least two, i.e., ∑u∈NG(v)f(u)≥2. For any function f:V(G)→{0,1,2} and any pair of adjacent vertices with f(v)=0 and u with f(u)>0, the function fu→v is defined by fu→v(v)=1, fu→v(u)=f(u)−1 and fu→v(x)=f(x) whenever x∈V(G)∖{u,v}. A secure Italian dominating function on a graph G is defined as an IDF f which satisfies that for every vertex v with f(v)=0, there exists a neighbour u with f(u)>0 such that fu→v is an IDF. The weight of f is ω(f)=∑v∈V(G)f(v). The minimum weight among all secure Italian dominating functions on G is the secure Italian domination number of G. This paper is devoted to initiating the study of the secure Italian domination number of a graph. In particular, we prove that the problem of finding this parameter is NP-hard and we obtain general bounds on it. Moreover, for certain classes of graphs, we obtain closed formulas for this novel parameter.

  • Segmentation Quality Refinement in Large-Scale Medical Image Dataset with Crowd-Sourced Annotations
    • Tomasz Dziubich
    • Jan Cychnerski
    2021

    Deployment of different techniques of deep learning including Convolutional Neural Networks (CNN) in image classification systems has accomplished outstanding results. However, the advantages and potential impact of such a system can be completely negated if it does not reach a target accuracy. To achieve high classification accuracy with low variance in medical image classification system, there is needed the large size of the training data set with suitable quality score. This paper presents a study on the use of various consistency checking methods to refine the quality of annotations. It is assumed that tagging was done by volunteers (crowd-sourcing model). The aim of this work was to evaluate the fitness of this approach in the medical field and the usefulness of our innovative web tool designed to facilitate large-scale annotation of magnetic resonance (MR) images, as well as the accuracy of crowd-source assessment using this tool, comparing to expert classification. We present the methodology followed to annotate the collection of kidney MR scans. All of the 156 images were acquired from the Medical University of Gdansk. Two groups of students (with and without medical educational background) and three nephrologists were engaged. This research supports the thesis that some types of MR image annotations provided by naive individuals are omparable to expert annotation, but this process could be shortened in time. Furthermore, it is more costeffective in the simultaneous preservation of image analysis accuracy. With pixel-wise majority voting, it was possible to create crowd-sourced organ segmentations that match the quality of those created by individual medical experts (mAP up to 94% +/-3.9%).

  • Segmented bio-based polyurethane composites containing powdered cellulose obtained from novel bio-based diisocyanate mixtures
    • Ewa Głowińska
    • Paulina Kasprzyk
    • Janusz Datta
    2021 Pełny tekst WOOD SCIENCE AND TECHNOLOGY

    A considerable number of research works focus on the positive influence of cellulose on the properties of polymer-based composites and their wide range of application possibilities. The present work is focused on the synthesis of novel bio-based polyurethane (bio-PU) composites filled with powdered cellulose (microcellulose, MC) in an amount of 5 wt.%. Bio-PU composites were synthesized via a non-solvent prepolymer method. First, the prepolymer was synthesized from diisocyanate mixture based on hexamethylene diisocyanate and bio-based polyisocyanate Tolonate™ X Flo 100 and α,ω-oligo(ethylene-butylene adipate)diol which contained cellulose. Then, resulted prepolymer was extended by bio-based 1,4 butanediol (bio-BDO). Bio-PU composites were obtained with the different [NCO]/[OH] molar ratios: 0.95, 1.0, 105 and 1.1. Special attention was paid to the influence of MC on the phase separation between soft and hard segments of bio-PU by studying the chemical structure, morphology and thermal and mechanical properties of the prepared cellulose-based composites.

  • Seismic damage diagnosis in adjacent steel and RC MRFs considering pounding effects through improved wavelet-based damage-sensitive feature
    • Benyamin Mohebi
    • Omid Yazdanpanah
    • Farzin Kazemi
    • Antonio Formisano
    2021 Journal of Building Engineering

    This paper aims to propose complex Morlet (cmorfb-fc) wavelet-based refined damage-sensitive feature (rDSF) as a new and more precise damage indicator to diagnose seismic damages in adjacent steel and Reinforced Concrete (RC) Moment Resisting Frames (MRFs) assuming pounding conditions using acceleration responses. The considered structures include 6- and 9-story steel and 4- and 8-story RC benchmark MRFs that are assumed to have different values of separation distances, δMT, calculated according to the ASCE 7-10 seismic provision. For the sake of pounding modelling, linear viscoelastic contact elements among the pounding structures are assumed. Furthermore, an algorithm is developed to compute the seismic collapse capacities of each pounding MRF through Incremental Dynamic Analyses (IDA) using OpenSees software. In the next step, auto-regressive movingaverage with exogenous input (ARX) model together with a stabilization diagram is utilized to appraise the natural frequencies of each adjacent MRF. Shannon entropies and correlation coefficient (ρ) are used to select the best cmorfb-fc wavelet. Based on the results, damage resulting from pounding effects can be accurately detected in both cases of with and without δMT, especially for steel MRFs.

  • Seismic Pounding Between Bridge Segments: A State-of-the-Art Review
    • Mahmoud Miari
    • Kok Choong
    • Robert Jankowski
    2021 ARCHIVES OF COMPUTATIONAL METHODS IN ENGINEERING

    Earthquake-induced structural pounding in bridge structures has been observed in several previous seismic events. Collisions occur at the expansion joints provided between adjacent decks or between the deck and abutment. Pounding between the structural elements may lead to severe damages and even to the unseating of the bridge in certain cases. Several investigations have been performed to study pounding in bridges under uniform and non-uniform seismic excitations. Moreover, different mitigation measures have been suggested to overcome the drawbacks of this phenomenon. This work reviews previous research studies concerning earthquake-induced structural pounding in bridge structures, the factors that influence it and the recommended mitigation measures.

  • Selected Aspects of Pavement Texture Influence on Tire Rolling Resistance
    • Jerzy Ejsmont
    • Sławomir Sommer
    2021 Pełny tekst Coatings

    Tire rolling resistance has a significant influence on fuel consumption in cars and trucks and on CO2 emissions. Rolling resistance depends on the tire construction, pavement texture and stiffness, as well as environmental and traffic conditions. This article presents a pilot study on the impact of pavement texture on the rolling resistance of passenger car tires. Reasons why Mean Profile Depth is not a good descriptor of pavement characteristics from the point of view of rolling resistance are presented, and an experimental method which takes into account tire deformation on texture and partial enveloping is described. A method based on testing the volume and depth of tire tread deformation is also proposed.

  • Selected information technology tools supporting for maintenance and operation management electrical grids
    • Waldemar Kamrat
    2021 Pełny tekst Bulletin of the Polish Academy of Sciences-Technical Sciences

    The paper presents the main issues of management of electrical grids. Selected information technology tools supporting for electrical grids maintenance are presented. In electrical infrastructure maintenance of power companies the geographic information systems are increasingly used to support the management of theirs resources. Their functionalities in terms creating comprehensive databases for electrical infrastructure of power sector are described. The important information technology tools regarding spatial systems for supporting maintenance and operation management electrical grids and the conditions of their implementation are presented. This paper also attempts to innovative multidimensional evaluate the technical and economic benefits resulting from the use of modern information technology tools for the management of energy infrastructure.

  • Selected manufacturing difficulties encountered during setup of machining on cnc multi-axis linear automatic lathe and on cnc multi-spindle turning centers
    • Piotr Sender
    2021 Pełny tekst

    The article presents the observed manufacturing technology implementation difficulties in workshop practice, resulting from the construction and principles of operation on the DMG’s SPRINT 32/5 CNC linear automatic lathe and on the Mazak’s HQR 150 MSY and QTN 200 MS CNC turn - mill centers, and discusses possible rules for solving the production problems encountered. The article also discusses the principles of dividing the machining process and working steps on multi-spindle CNC turn - mill centers. It is worth to build a system supporting the selection of the sequence of treatments [1], taking into account the frequency of natural vibrations and stiffness obtained after each single machining operations. The article shows the method of verification of the selection of the machining planning method on CNC multi-spindle lathes.

  • Selected problems of decision making modelling in power engineering
    • Waldemar Kamrat
    2021 Pełny tekst Sustainable Energy Technologies and Assessments

    The paper presents the selected problems of decision making modelling in power engineering specially investment risk evaluation methods. The proposed model can be used in the range programming the development and investing process in power engineering. Decision making problems in power engineering and the evaluation of investment effectiveness in particular are closely related to modelling which relatively accurately reflects the complexity of market economy mechanisms. In order to analyze the phenomena mentioned above, models of existing processes, which are later used to achieve a set goal during decision making in a real situation, are applied. Its mathematical representation is a formalization of a model of a decision making task. A significant task in the whole process is to design a mathematical model, optimized by means of a goal function, whose arguments are decision variables meeting defined boundary conditions. Descriptions of decision making processes show that variables usually have non-negative values. Also the economic environment influences the quality of modelling. The dynamics of events causes that models of decision making processes can be analyzed. An attempt to take into account the influence of the factors mentioned above on the modelling of decision making in power engineering is presented in this paper.

  • Selection of an artificial pre-training neural network for the classification of inland vessels based on their images
    • Katarzyna Bobkowska
    • Izabela Bodus-olkowska Izabela
    2021 Pełny tekst Zeszyty Naukowe Akademii Morskiej w Szczecinie

    Artificial neural networks (ANN) are the most commonly used algorithms for image classification problems. An image classifier takes an image or video as input and classifies it into one of the possible categories that it was trained to identify. They are applied in various areas such as security, defense, healthcare, biology, forensics, communication, etc. There is no need to create one’s own ANN because there are several pre-trained networks already available. The aim of the SHREC projects (automatic ship recognition and identification) is to classify and identify the vessels based on images obtained from closed-circuit television (CCTV) cameras. For this purpose, a dataset of vessel images was collected during 2018, 2019, and 2020 video measurement campaigns. The authors of this article used three pre-trained neural networks, GoogLeNet, AlexNet, and SqeezeNet, to examine the classification possibility and assess its quality. About 8000 vessel images were used, which were categorized into seven categories: barge, special-purpose service ships, motor yachts with a motorboat, passenger ships, sailing yachts, kayaks, and others. A comparison of the results using neural networks to classify floating inland units is presented.

  • Selective monitoring of noise emitted by vehicles involved in road traffic
    • Andrzej Czyżewski
    • Tomasz Śmiałkowski
    2021 Pełny tekst Journal of the Acoustical Society of America

    An acoustic intensity probe was developed measures the sound intensity in three orthogonal directions, making possible to calculate the azimuth and elevation angles, describing the sound source position. The acoustic sensor is made in the form of a cube with a side of 10 mm, on the inner surfaces of which the digital MEMS microphones are mounted. The algorithm works in two stages. The first stage is based on the analysis of sound intensity signals, and it detects acoustic events. The second stage analyses a detection function based on the normalized source position; its task is to determine whether the acoustic event represents a vehicle passing the sensor and detecting its movement direction. The acoustic probes were mounted inside intelligent lamps that illuminate the roadways depending on the volume of traffic. The paper explains how accurately traffic can be monitored through directional noise analysis and shows the resulting application to smart cities.

  • Selenium enrichment in broccoli sprouts as an initial step in the preparation of Certified Reference Material
    • Chintankumar Padariya
    • Małgorzata Rutkowska
    • Piotr Konieczka
    2021 Pełny tekst

    Selenium is considered one of the essential elements in animals and humans. The main source of selenium intake for humans is the diet. Selenium deficiency has one of the most concerning issues worldwide. Broccoli sprouts are five-to-six-day old broccoli plants, and they may exhibit stronger chemoprotective effects. Thus, the enrichment of selenium in broccoli sprouts can enhance anticancer properties. As a result of conducted study, four batches of selenium enriched sprouts have been produced in order to verify the efficiency of selenium uptake by broccoli sprouts under commercial conditions. –1 Sodium selenite solution (10 mg L ) was used to prepare seleniumenriched broccoli sprouts. Sodium selenite is available for biological uptake by plants. The results might be different while the addition of sodium selenite in each step of the germination process could enhance the concentration of selenium in broccoli sprouts. Therefore, it could be potentially selected as a candidate for certified reference materials

  • Self Portrait with a Mask
    • Paweł Sasin
    2021 Pełny tekst Sztuka i Dokumentacja

    Paweł SASIN - Self Portrait with a Mask “Every work of art is the child of its time, and, in many cases, the mother of our emotions. “ Wassily Kandynsky, Concerning the Spiritual in Art The two years 2020 and 2021 were marked by the COVID-19 pandemic – a lengthy period of time in which everyone felt in danger of losing one’s health or life. As a result, many people were experiencing negative emotion, becoming subject to psychological stress: feeling anxious, fearful, frustrated, upset, depressed. In such situations, finding motivations to overcome these feelings is crucial and positive, as it helps people to overcome inactivity and achieve goals. During the phase of stress mobilization, one often experiences elevated efficiency of intellectual and cognitive processes: the ability to make associations and conceive unique ideas is enhanced, as well as one’s sensitivity to stimuli; which results in people accessing a greater range of their potential abilities (Frączek, Kofta, „Frustracja i stres psychologiczny”/ “Frustration and Psychological Stress”). What I am about to present is an attempt to address the question of the influence which the COVID-19 pandemic, as a socially challenging experience, may have had on the spontaneity and authenticity of creative imagination possessed by people studying architecture. Obligatory isolation, social distancing and other restraining regulations, dangers stemming from the infectious qualities of the disease, finally the huge number of gravely ill and deceased victims – those circumstance served as a trigger to ask architecture students at the Gdańsk University of Technology to create a piece on the topic Self Portrait with a Mask as part of their sculpture course.

  • Self-assembly of vertically oriented graphene nanostructures: multivariate characterisation by Minkowski functionals and fractal geometry
    • Mattia Pierpaoli
    • Mateusz Ficek
    • Paweł Jakóbczyk
    • Jakub Karczewski
    • Robert Bogdanowicz
    2021 Pełny tekst ACTA MATERIALIA

    The enormous self-assembly potential that graphene and its derived layered materials offer for responding to the contemporary environmental challenges has made it one of the most investigated materials. Hence, tuning its extraordinary properties and understanding the effect at all scales is crucial to tailoring highly customised electrodes. Vertically oriented graphene nanostructures, also known as carbon nanowalls (CNWs), due to the large surface area and unique maze-like morphology, have attracted attention as a platform for advanced sensing applications. In this work, a holistic investigation approach has been developed to disrupt the synthesis-composition-structure-property paradigm and to dig out the hidden materials relationships. To achieve that, autonomous advanced image-analysis methods (Minkowski Functionals, Fractal Analysis) have been applied to SEM micrographs and successfully classified them. Morphological, electrical, and electrochemical characterisation has been performed for all of the samples. Multivariate data analysis has been employed to mine the relationships between the material features, specifically as it relates to the understanding of the intrinsic properties. As a result, this study is intended to both shed light on CNWs as a promising transparent hybrid electrochemical substrate for perfectly assembled electrochemical devices and to provide a new flexible method for nanomaterial design, characterisation and exploitation.