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Gdańsk University of Technology

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  • Association of Genes Related to Oxidative Stress with the Extent of Coronary Atherosclerosis
    • Milena Racis
    • Anna Stanisławska-Sachadyn
    • Wojciech Sobiczewski
    • Marcin Wirtwein
    • Michał Krzemiński
    • Natalia Krawczyńska
    • Janusz Limon
    • Andrzej Rynkiewicz
    • Marcin Gruchała
    2020 Full text Life

    Oxidative stress is believed to play a critical role in atherosclerosis initiation and progression. In line with this, in a group of 1099 subjects, we determined eight single nucleotide polymorphisms (SNPs) related to oxidative stress (PON1 c.575A>G, MPO c.463G>A, SOD2 c.47T>C, GCLM c.590C>T, NOS3 c.894G>T, NOS3 c.786T>C, CYBA c.214C>T, and CYBA c.932A>G) and assessed the extent of atherosclerosis in coronary arteries based on Gensini score. An increased risk of having a Gensini score in the higher half of the distribution was observed for the PON1 c.575G allele (odds ratio (OR) = 1.27, 95% confidence interval (CI): 1.004–1.617, p = 0.046). Next, the genetic risk score (GRS) for the additive eect of the total number of pro-oxidative alleles was assessed. We noted an increase in the risk of having a Gensini score above the median with the maximum number of risk alleles (OR = 2.47, 95% CI: 1.19–5.23, p = 0.014). A univariate Spearman’s test revealed significant correlation between the total number of pro-oxidant alleles (GRS) and the Gensini score ( = 0.068, p = 0.03). In conclusion, the PON1 c.575A>G variant and the high number of risk alleles (GRS) were independent risk factors for a high Gensini score. We suggest, however, that GRS might occur as a more valuable component in adding a predictive value to the genetic background of atherosclerosis.

  • Attempt to a Video-Transmission Capability in MV Mine Cable Network Using BPL-PLC Technology
    • Grzegorz Debita
    • Przemysław Falkowski-Gilski
    • Marcin Habrych
    • Bogdan Miedziński
    • Grzegorz Wiśniewski
    • Przemysław Jedlikowski
    • Bartosz Polnik
    2020

    This article presents and discusses the attempt to transmit video content using the BPL-PLC (Broadband over Power Line - Power Line Communication) technology. It includes simulation results of a specially developed digital transmitter and receiver, dedicated to a given predefined 6 kV mining power cable. The effect of two different transmission modes (2-7 MHz and 3-7.5 MHz) and two types of coupling (capacitive-inductive and induction-inductive), on the quality of bi-directional transmission, was also examined. The quality assessment of transmitted content, including both QoS (Quality of Service) and QoE (Quality of Experience) approaches, was evaluated on a set of samples processed in different resolution, namely: 480x270, 768x432, and 1280x720. Based on this, conclusions have been formulated, regarding the expected efficiency, as well as guidelines for further video transmission tests, including real-time mining conditions.

  • Atypical application of the parametric method for track infrastructure inventory
    • Krzysztof Czaplewski
    • Cezary Specht
    • Władysław Koc
    • Andrzej Wilk
    • Krzysztof Karwowski
    • Paweł Dąbrowski
    • Mariusz Specht
    • Piotr Chrostowski
    • Jacek Szmagliński
    2020 Full text Zeszyty Naukowe Akademii Morskiej w Szczecinie

    For many years, satellite systems have seen widespread use in a variety of technical applications, as well as in operations related to setting-out and the exploitation of track infrastructure. Their main applications include an inventory of the trackage course and detecting changes in its position. In both of these tasks, the most important element that determines the quality of an analyses is the high accuracy of the determinations being carried out. Satellite surveying techniques are not always sufficiently accurate, and in such cases, it is necessary to employ other land surveying methods to process surveying data. This article presents the authors’ considerations with regards to the possibility of applying one of the most common land surveying adjustment methods, the parametric method, to operations related to an inventory of tram infrastructure in Gdańsk. The results are based on surveys carried out during a surveying campaign in the autumn of 2018. The considerations presented in the article concern a small part of the research conducted under project No. POIR.04.01.01-00-0017/17 entitled “Development of an innovative method for determining the precise trajectory of a railborne vehicle” which is being implemented by a consortium of Gdansk University of Technology and Gdynia Maritime University.

  • Audio Feature Analysis for Precise Vocalic Segments Classification in English
    • Szymon Zaporowski
    • Andrzej Czyżewski
    2020

    An approach to identifying the most meaningful Mel-Frequency Cepstral Coefficients representing selected allophones and vocalic segments for their classification is presented in the paper. For this purpose, experiments were carried out using algorithms such as Principal Component Analysis, Feature Importance, and Recursive Parameter Elimination. The data used were recordings made within the ALOFON corpus containing audio signal recorded employing 7 speakers who spoke English at the native or near-native speaker level withing a Standard Southern British English variety accent. The recordings were analyzed by specialists from the field of phonology in order to extract vocalic segments and selected allophones. Then parameterization was made using Mel Frequency Cepstral Coefficients, Delta MFCC, and Delta Delta MFCC. In the next stage, feature vectors were passed to the input of individual algorithms utilized to reduce the size of the vector by previously mentioned algorithms. The vectors prepared in this way have been used for classifying allophones and vocalic segments employing simple Artificial Neural Network (ANN) and Support Vector Machine (SVM). The classification results using both classifiers and methods applied for reducing the number of parameters were presented. The results of the reduction are also shown explicitly, by indicating parameters proven to be significant and those rejected by particular algorithms. Factors influencing the obtained results were discussed. Difficulties associated with obtaining the data set, its labeling, and research on allophones were also analyzed.

  • AutoCAD: Examination of Factors Influencing User Adoption
    • Anna Baj-Rogowska
    2020 Full text Engineering Management in Production and Services

    The primary purpose of the research is to examine and validate determinants of user intention to use AutoCAD software, utilising the constructs from prior studies in a more integrated model. The paper proposes a revised Technology Acceptance Model (TAM) for measuring the adoption of AutoCAD. In the study, a latent construct PPA (perceived physical accessibility) was added to the proposed research model as a new determinant of AutoCAD adoption. An online survey of AutoCAD users was conducted to collect data. This data was empirically used to test the proposed research model. The Structural Equation Modelling (SEM) technique was used to evaluate the causal model, and the confirmatory factor analysis was performed to examine the reliability and validity of the measurement model. The study results show that user behavioural intention to use AutoCAD is significantly affected by three determinants: perceived usefulness, perceived ease of use and perceived physical accessibility of the software. This finding contributes to an expanded understanding of the factors that promote acceptance of AutoCAD software. Moreover, the main contribution of this study is to verify the impact of the added PPA variable on the behavioural intention to use and the actual use of AutoCAD, and also to create measurement scales for this new latent variable in TAM.

  • Autogenous Fiber Laser Welding of 316L Austenitic and 2304 Lean Duplex Stainless Steels
    • Michał Landowski
    • Aleksandra Świerczyńska
    • Grzegorz Rogalski
    • Dariusz Fydrych
    2020 Full text Materials

    This study presents results of experimental tests on quality of dissimilar welded joints between 316L austenitic and 2304 lean duplex stainless steels, welded without ceramic backing. Fiber laser welded butt joints at a thickness of 8 mm were subjected to non‐destructive testing (visual and penetrant), destructive testing (static tensile test, bending test, and microhardness measurements) and structure observations (macro‐ and microscopic examinations, SEM, element distribution characteristics, and ferrite content measurements). Non‐destructive tests and metallographic examinations showed that the welded joints meet the acceptance criteria for B level in accordance with EN ISO 13919–1 standard. Also the results of the destructive tests confirmed the high quality of the joints: specimens were fractured in base material with lower strength—316L austenitic stainless steel and a 180° bending angle was obtained confirming the high plasticity of the joints. Microscopic examination, SEM and EDS analysis showed the distribution of alloying elements in joints. The microhardness of the autogenous weld metal was higher by about 20 HV0.2 than that of the lean duplex steel. Ferrite content in the root was about 37% higher than in the face of the weld. The Schaeffler phase diagram was used to predict the phase composition of the welded joints and sufficient compliance with the magnetic method was found. The presented procedure can be used for welding of 316L–2304 stainless steels dissimilar welded joints of 8 mm thickness without ceramic backing.

  • Automated Classifier Development Process for Recognizing Book Pages from Video Frames
    • Adam Brzeski
    • Jan Cychnerski
    • Karol Draszawka
    • Krystyna Dziubich
    • Tomasz Dziubich
    • Waldemar Korłub
    • Paweł Rościszewski
    2020 Communications in Computer and Information Science

    One of the latest developments made by publishing companies is introducing mixed and augmented reality to their printed media (e.g. to produce augmented books). An important computer vision problem that they are facing is classification of book pages from video frames. The problem is non-trivial, especially considering that typical training data is limited to only one digital original per book page, while the trained classifier should be suitable for real-time utilization on mobile devices, where camera can be exposed to highly diverse conditions and computing resources are limited. In this paper we address this problem by proposing an automated classifier development process that allows training classification models that run real-time, with high usability, on low-end mobile devices and achieve average accuracy of 88.95% on our in-house developed test set consisting of over 20 000 frames from real videos of 5 books for children. At the same time, deployment tests reveal that the classifier development process time is reduced approximately 16-fold.

  • Automatic Marking of Allophone Boundaries in Isolated English spoken Words
    • Janusz Rafałko
    • Andrzej Czyżewski
    2020 Full text

    The work presents a method that allows delimiting the borders of allophones in isolated English words. The described method is based on the DTW algorithm combining two signals, a reference signal and an analyzed one. As the reference signal, recordings from the MODALITY database were used, from which the words were extracted. This database was also used for tests, which were described. Test results show that the automatic determination of the allophone limits in English words is possible with good accuracy. Tests have been carried out to determine the error of particular allophones borders marking and to find out the cost of matching the given allophone to the reference one. Based on this cost, a coefficient has been introduced that allows for determining in percentage how much the automatically marked allophone is similar to the reference one. This coefficient can be used for an assessment of the correctness of the pronunciation of the allophone. The possibilities of further research and development of this method were also analyzed.

  • Automatic Threat Detection for Historic Buildings in Dark Places Based on the Modified OptD Method
    • Wioleta Błaszczak-bąk
    • Czesław Suchocki
    • Joanna Janicka
    • Andrzej Dumalski
    • Robert Duchnowski
    • Anna Sobieraj-Żłobińska
    2020 Full text ISPRS International Journal of Geo-Information

    Historic buildings, due to their architectural, cultural, and historical value, are the subject of preservation and conservatory works. Such operations are preceded by an inventory of the object. One of the tools that can be applied for such purposes is Light Detection and Ranging (LiDAR). This technology provides information about the position, reflection, and intensity values of individual points; thus, it allows for the creation of a realistic visualization of the entire scanned object. Due to the fact that LiDAR allows one to ʹseeʹ and extract information about the structure of an object without the need for external lighting or daylight, it can be a reliable and very convenient tool for data analysis for improving safety and avoiding disasters. The main goal of this paper is to present an approach of automatic wall defect detection in unlit sites by means of a modified Optimum Dataset (OptD) method. In this study, the results of Terrestrial Laser Scanning (TLS) measurements conducted in two historic buildings in rooms without daylight are presented. One location was in the basement of the ruins of a medieval tower located in Dobre Miasto, Poland, and the second was in the basement of a century‐old building located at the University of Warmia and Mazury in Olsztyn, Poland. The measurements were performed by means of a Leica C‐10 scanner. The acquired dataset of x, y, z, and intensity was processed by the OptD method. The OptD operates in such a way that within the area of interest where surfaces are imperfect (e.g., due to cracks and cavities), more points are preserved, while at homogeneous surfaces (areas of low interest), more points are removed (redundant information). The OptD algorithm was additionally modified by introducing options to detect and segment defects on a scale from 0 to 3 (0—harmless, 1—to the inventory, 2—requiring repair, 3—dangerous). The survey results obtained proved the high effectiveness of the modified OptD method in the detection and segmentation of the wall defects. The values of area of changes were calculated. The obtained information about the size of the change can be used to estimate the costs of repair, renovation, and reconstruction.

  • Autonomous Ship Utility Model Parameter Estimation Utilising Extended Kalman Filter
    • Anna Witkowska
    • Krzysztof Armiński
    • Tomasz Zubowicz
    • Filip Ossowski
    • Roman Smierzchalski
    2020

    In this paper, a problem of autonomous ship utility model identification for control purposes is considered. In particular, the problem is formulated in terms of model parameter estimation (one-step-ahead prediction). This is a complex task due to lack of measurements of the parameter values, their time-variability and structural uncertainty introduced by the available models. In this work, authors consider and compare two utility models based on often utilised ship model structures with time-varying parameters identified recursively using the extended Kalman lter (EKF). The validation results have been obtained using simulation experiments in which the required information for the parameter estimation task had been generated using a cognitive model of B-481 ship. The results indicate the benefits and drawbacks, In terms of estimation accuracy and computational complexity, of using each of the investigated utility model structures.

  • Auto-tuning methodology for configuration and application parameters of hybrid CPU + GPU parallel systems based on expert knowledge
    • Paweł Czarnul
    • Paweł Rościszewski
    2020 Full text

    Auto-tuning of configuration and application param- eters allows to achieve significant performance gains in many contemporary compute-intensive applications. Feasible search spaces of parameters tend to become too big to allow for exhaustive search in the auto-tuning process. Expert knowledge about the utilized computing systems becomes useful to prune the search space and new methodologies are needed in the face of emerging heterogeneous computing architectures. In this paper we propose an auto-tuning methodology for hybrid CPU/GPU applications that takes into account previous execution experi- ences, along with an automated tool for iterative testing of chosen combinations of configuration, as well as application-related parameters. Experimental results, based on a parallel similarity search application executed on three different CPU+GPU parallel systems, show that the proposed methodology allows to achieve execution times worse by only up to 8% compared to a search algorithm that performs a full search over combinations of application parameters, while taking only up to 26% time of the latter.

  • Axial-Flux Permanent-Magnet Dual-Rotor Generator for a Counter-Rotating Wind Turbine
    • Filip Kutt
    • Krzysztof Blecharz
    • Dariusz Karkosiński
    2020 Full text ENERGIES

    Coaxial counter-rotating propellers have been widely applied in ships and helicopters for improving the propulsion efficiency and offsetting system reactive torques. Lately, the counter-rotating concept has been introduced into the wind turbine design. Distributed wind power generation systems often require a novel approach in generator design. In this paper, prototype development of axial-flux generator with a counter-rotating field and armature is presented. The design process was composed of three main steps: analytical calculation, FEM simulation and prototype experimental measurements. The key aspect in the prototype development was the mechanical construction of two rotating components of the generator. Sturdy construction was achieved using two points of contact between both rotors via the placement of the bearing between the inner and outer rotor. The experimental analysis of the prototype generator has been conducted in the laboratory at the dynamometer test stand equipped with a torque sensor. The general premise for the development of such a machine was an investigation into the possibility of developing a dual rotor wind turbine. The proposed solution had to meet certain criteria such as relatively simple construction of the generator and the direct coupling between the generator and the wind turbines. The simple construction and the lack of any gearbox would allow for such a system to be constructed relatively cheaply, which is a key aspect in further system development.

  • Badania bezczujnikowego układu napędowego z silnikiem pięciofazowym w normalnych i awaryjnych stanach pracy.
    • Filip Wilczyński
    • Marcin Morawiec
    • Krzysztof Blecharz
    • Andrzej Jąderko
    2020 Full text Przegląd Elektrotechniczny

    W artykule przedstawiono bezczujnikowe sterowanie polowo zorientowane dla pięciofazowego silnika indukcyjnego. Zaproponowany układ sterowania został przebadany pod kątem możliwej pracy w przypadku braku zasilania jednej oraz dwóch faz stojana silnika. Zaprezentowane wyniki badań eksperymentalnych przeprowadzono dla normalnego i awaryjnego trybu pracy napędu w zakresach prędkości ponad znamionowych oraz bardzo niskich.

  • Badania doświadczalne przyczepności
    • Marcin Burdziński
    • Maciej Niedostatkiewicz
    2020 Full text Builder

    W artykule przedstawiono podstawowe informacje dotyczące zjawisko przyczepności stalowych prętów i betonu, w sposób szczegółowy opisano autorski program badań tego zjawiska

  • Badania eksperymentalne stalowych łączników balkonowych typu podwójnego
    • Maciej Solarczyk
    • Paweł Piotrkowski
    • Maciej Niedostatkiewicz
    2020

    Artykuł stanowi prezentację wyników badań eksperymentalnych przeprowadzonych na czterech pełnowymiarowych prefabrykowanych zestawach balkonowych o wymiarach (szerokość × długość × wysokość): 2,0 m × 2,78 m × 0,186 m (w spadku do 0,17 m). Zestawy składały się z żelbetowych płyt (balkonowej oraz stropowej), połączonych ze sobą łącznikami balkonowymi typu podwójnego (łącznik składający się z dwóch prętów rozciąganych oraz dwóch blach ścinanych, połączonych ze sobą za pomocą środnika przekroju ceowego). Publikacja jest kontynuacją tematyki podjętej w pracy [1]. Przeanalizowano wpływ zmiennych parametrów na nośność elementów. Przedstawiono przegląd literatury naukowej z zakresu łączników balkonowych [2, 3].

  • Badania nieniszczące jakości spoin szyn poddźwigowych na nabrzeżu przeładunkowym T1 w DCT w Porcie Północnym
    • Wojciech Kiełczyński
    • Jacek Haras
    • Marian Siejka
    2020

    Celem podstawowym niniejszego opracowania było sprawdzenie za pomocą NDT jakości spoin wykonanych w ramach prac naprawczych w DCT w roku 2017 (styki szyn poddźwigowych typu A120 na nabrzeżu T1 w DCT Port Północny Gdańsk). W ramach opracowania: 1) Ustalono zakres badań - na podstawie potrzeb Kierownictwa Infrastrukury DCT; b) Analizowano wyniki badań nieniszczących wykonanych w sierpniu 2017r.; c) Wykonano badania UT-puls i MT oraz pomiary ugięcia szyn poddźwigowych na odcinkach 1m wg wskazań Zleceniodawcy; 4) Sporządzono raporty z badań NDT; 5) Opracowano wyniki badań nieniszczących.

  • Badania tribologicznych właściwości nanokompozytowych warstw Ni-P/Si3N4 osadzanych metodą redukcji chemicznej na stopie aluminium AW-7075
    • Kazimierz Czapczyk
    2020 Full text Przemysł Chemiczny

    Przedstawiono wyniki tribologicznych badań warstw nanokompozytowych Ni-P/Si3N4 i niklowych Ni-P osadzonych na stopie aluminium AW-7075 metodą redukcji chemicznej, a także stopu AW-7075 bez powłoki. Warstwy nanokompozytowe wytworzono, stosując azotek krzemu Si3N4 w postaci polidyspersyjnego proszku o wielkości cząstek 20–25 nm. Analizowano wpływ zawartości w materiale warstwy fazy dyspersyjnej na twardość i zużycie ścierne, którą określono metodą ball-on-disc. Topografię powierzchni zbadano metodą stykową za pomocą profilometru. Wprowadzenie cząstek Si3N4 do warstwy Ni-P spowodowało zwiększenie twardości oraz odporności na zużycie ścierne części ze stopu aluminium AW-7075 z osadzoną powłoką nanokompozytową. Warstwy Ni-P/Si3N4 charakteryzowały się lepszymi właściwościami tribologicznymi niż warstwy Ni-P oraz stop AW-7075 i stanowiły dobre zabezpieczenie przed zużyciem ściernym.

  • Badanie jakości sieci komórkowych w przededniu technologii 5G na wybranym przykładzie
    • Przemysław Falkowski-Gilski
    • Tadeus Uhl
    2020 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    Wraz z rosnącą popularnością i dostępnością urządzeń mobilnych, zwiększa się liczba abonentów w sieci. Fakt ten prowadzi do wzrostu świadomości użytkowników, pod kątem jakości treści, które konsumują. Wielu dostawców usług oraz operatorów skupia swoje działania na monitorowaniu parametrów jakościowych QoN (Quality of Network) i QoS (Quality of Service). Niniejsza praca przed-stawia wyniki badań przeprowadzonych na terenie kampusu uniwersyteckiego, uwzględniając ogólną wydajność sieci komórkowych w przededniu technologii 5G.

  • Badanie jakości wybranych produktów
    • Maria Szpakowska
    • Ewa Marjańska
    • Elwira Brodnicka
    • Wojciech Szpakowski
    2020

    W monografii „Badania jakości wybranych produktów” scharakteryzowano siedem grup produktów żywnościowych oraz dwie grupy produktów nieżywnościowych i opisano badania pozwalające na ocenę ich jakości, które można wykonać w laboratorium Katedry Nauk o Jakości Wydziału Zarządzania i Ekonomii Politechniki Gdańskiej. Są to: pieczywo, tłuszcze jadalne, mleko i płynne produkty mleczne, jaja i produkty jajeczne, wody pitne, gazowane napoje bezalkoholowe, produkty przemysłu fermentacyjnego, papier i opakowania z papieru, metale, stopy metali, minerały i kamienie szlachetne. Każdy rozdział opisujący poszczególną grupę produktów składa się z pięciu podroz¬działów: części teoretycznej (podrozdziały 1–4) i praktycznej (podrozdział 5). W części teoretycznej omówiono skład i rodzaje produktów z danej grupy, właściwości fizyko¬chemiczne, organoleptyczne i inne cechy jakościowe oraz – w niektórych przypadkach – procesy technologiczne. W części praktycznej opisano metody wyznaczania niektórych właściwości fizykochemicznych, sposoby oceny jakości wybranych produktów, a także rozpoznawania autentyczności niektórych wyrobów jubilerskich.. Dziewięć rozdziałów opisujących wybrane produkty i badania ich jakości poprzedzono dwoma rozdziałami, w których zaprezentowano sposoby przedstawienia wyników pomiarów i obserwacji oraz analizę błędów pomiarów wielkości fizycznych. Niniejsza książka jest przeznaczona dla studentów kierunków studiów społecznych w zakresie nauk o jakości, a w szczególności ma stanowić bazę do przedmiotu jakość produktu, realizowanego w ramach studiów I stopnia na Wydziale Zarządzania i Ekonomii Politechniki Gdańskiej. Ze względu na zamieszczone schematy blokowe procesów technologicznych produkcji wybranych produktów książka ta będzie pomocna dla studentów realizujących przedmiot technologia produktu. Opracowanie powinno być przydatne również studentom lub wykładowcom z innych uczelni, zajmującym się szeroko pojętą jakością różnych produktów oferowanych konsumentom w handlu.

  • Badanie jakościowe zachowań w organizacji
    • Tomasz Ochinowski
    • Marta Szeluga-Romańska
    2020

    Publikacja jest zbiorem specjalistycznych tekstów przygotowanych przez polskich psychologów pracy, organizacji oraz zachowań konsumenckich. To rezultat współdziałania ekspertów z wielu dziedzin, których łączy ciekawość zachowań ludzkich w przestrzeni biznesu. Publikacja prezentuje psychologię biznesu szeroko, zgodnie z aktualnymi programami kształcenia w prestiżowych ośrodkach, ale zakorzenia ją w polskich realiach, uwzględniając pokaźny dorobek polskich teoretyków i badaczy.

  • Badanie wytrzymałości połączeń klejonych węglowych i aluminiowych elementów zawieszenia bolidu formuły student
    • Michał Formela
    • Adrian Pluto-Prondziński
    • Andrzej Grucza
    2020

    Podczas projektowania innowacyjnego zawieszenia, które pozwoliłoby uzyskać przewagę nad konkurencyjnymi bolidami Formuły Student, postawiono warunek, aby jak najbardziej zmniejszyć masę elementów. Używane do tej pory rurki wykonane ze stali S235 o średnicy zewnętrznej 12 mm i grubości 2 mm oraz w miejscach bardziej obciążonych o średnicy zewnętrznej 14 mm i grubości 2 mm cechowały się znaczną masą. Ich głównym zadaniem jest połączenie ramy bolidu ze zwrotnicą (rys. 1 i rys. 2). Po porównaniu własności wytrzymałościowych rurki stalowe postanowiono zastąpić kompozytowymi rurkami z włókna węglowego. Wiele zespołów, mających już wieloletnie doświadczenie, zajmujących corocznie znaczące pozycje w zawodach Formuły Student zdecydowało, że takie rozwiązanie korzystnie wpływa na zachowanie się bolidu. W starym zawieszeniu końcówki wpustów zabezpieczano promieniową zawleczką, ale przy kompozycie takie rozwiązanie mogło nie być trwałe, więc zdecydowano się na połączenie klejone. Głównym problemem mogłoby być wykonanie promieniowego otworu w kompozycie, co nie tylko zmniejsza wytrzymałość samej rurki kompozytowej, ale podczas wiercenia lub powiercenia uszkadza poszczególne włókna, które są wcześniej nawijane w kolejnych warstwach na siebie. Próbki, a później gotowe elementy zawieszenia bolidu, wykonywane w ten sposób nie gwarantują powtarzalności, co za tym idzie, nie można jasno określić, czy dany element nie ulegnie uszkodzeniu bądź nawet zniszczeniu podczas wyścigu. Dlatego do połączenia elementów zawieszenia (metalowych insertów i rurek kompozytowych) zdecydowano się na połączenie klejone.Układ kinematyczny zawieszenia został zaprojektowany w taki sposób, że na wahacze działają w dużej mierze wyłącznie siły rozciągające i ściskające. Przekłada się to na powstawanie naprężeń ścinających w połączeniu rurka-wpust. W tym celu zaplanowano badanie rozciągania statycznego, które miało na celu sprawdzenie wytrzymałości na rozciąganie elementów zawieszenia (metalowych insertów i rurek kompozytowych) połączonych klejowo. Jest to ważniejsze tym bardziej, że w kartach technologicznych klejów z reguły podawana jest jedynie statyczna wytrzymałość połączeń (naprężenia normalne). Spośród wielu rodzajów kleju, które przeznaczone są do spajania kompozytów i metali wytypowano trzy, które uznano za umożliwiające uzyskanie najbardziej wytrzymałego połączenia klejonego. Kleje użyte do badania to: SCIGRIP SG5000-06, LOCTITE EA3423 i VIVTEK X705.06.B.

  • Balancing energy consumption in limited power grid with active front-end and three phase dual active bridge system
    • Konstantin Vorobev
    • Ryszard Strzelecki
    • Nikolai Poliakov
    2020 Full text

    Paper deals with simulation analysis of bidirectional power converters system for charging station of electric vehicle in condition of limited power source in city infrastructure. In case of incapability to provide additional power supply through the grid by virtue of historical, architectural and economic reasons it is possible to solve this issue by implementation of mobile battery-powered supply source. The proposed bidirectional power converters system for consist of three-phase dual active bridge two-directional converter and active front end. Bidirectional power converters system operation modes considered in the paper include transmission of energy from both the battery station, and grid and the joint power supply with battery and grid

  • Balkan Stock Exchanges – Consideration of the Length of the Estimation Window in Similar Markets
    • Katarzyna Kubiszewska
    • Marcin Potrykus
    2020 Full text European Research Studies Journal

    Purpose: We study if capital markets in the Balkan are closely and positively related in terms of rate of return, risk, efficiency, and maximum cumulative loss in relation to different lengths of the estimation window. Design/Methodology/Approach: The research was carried out for the period from 01/01/2017 to 31/12/2019 using portfolio analysis. It was divided into an estimation window (01/01/2019 to 31/12/2019) and another with observations from the remaining days. The results were compared with a naive strategy. Four-element portfolios, consisting of three investments in companies from a given stock exchange and one investment in gold as a haven, were created. After determining all possible combinations of portfolios for each stock exchange and for all lengths of estimation window, the obtained results for rate of return, risk, efficiency, for each length of estimation window were averaged and were subjected to correlation analysis. Findings: In Balkan capital markets, a change in the length of the estimation window (optimal length 120 observations) had the same impact on the results for investment portfolio risk, efficiency, and maximum cumulative loss, but not for the rate of return. Practical Implications: An investor from one of the Balkan countries using a strategy based on portfolio theory would not be able to gain a competitive advantage over another investor from this region if he built a portfolio based on the same number of observations from the past. The investor should construct an investment portfolio based on historical data from the previous six months. Longer estimation periods are not recommended, as the results for the studied portfolio were worse than a naive strategy. Originality/Value: The study concentrates on the unique region of Europe, which was the subject of system transformation latest therefore it should not be compared directly to the current achievements in the stock changes which tradition of operation is longer.

  • Bankruptcy Law Severity for Debtors: Comparative Analysis Among Selected Countries
    • Sylwia Morawska
    • Błażej Prusak
    • Przemysław Banasik
    • Katarzyna Pustułka
    • Bartosz Groele
    2020 Full text European Research Studies Journal

    Purpose: The objective of this paper is to propose the new indicator of bankruptcy law severity for debtors (BLSI-Bankruptcy Law Severity Index). On the basis of this index we conducted comparative analysis of debtor/creditor friendliness of bankruptcy laws among 27 selected countries. Design/Methodology/Approach: In the research the following methods were used: analysis of legal acts, literature review and expert method. Findings: The empirical results show that the most debtor-friendly bankruptcy and restructuring laws are those of the USA, Ireland and Canada. At the opposite pole were Slovenia, Australia and Austria. It can also be noted that many EU countries have a similar level of BLSI measure, which is most likely a consequence of harmonisation activities undertaken within the Community. Practical Implications: The conducted research enables us to propose the direction of changes in bankruptcy and restructuring laws in the next stage. Originality/value: On the basis of proposed BLSI, we will be able to examine the relationship between the severity of bankruptcy law and innovation, entrepreneurship and the level of development of financial markets in the studied countries.

  • Barriers to and Facilitators of Scientific Productivity: A Case Study from Polish Technical University
    • Magdalena Szuflita-Żurawska
    • Beata Basińska
    • Krzysztof Leja
    2020 Full text

    Scientific productivity plays an essential role in the creation of innovation and it stimulates social and economic growth. This study aimed to identify the barriers to and facilitators of scientific productivity in engineering and technology field, as perceived from the perspective of academic managers. Along with quality approach, the study relied on semi-structured interviews with managing bodies, i.e. seven deans and deputy deans from four faculties representing scientific field of engineering and technology. A single case study of Polish technical university was analysed in accordance with Braun and Clark’s six-step framework and coded in NVivo software. Findings fell into four themes: scientific publication, recognition, funding research, and collaboration. The results revealed more barriers than facilitators in terms of acceleration of and motivation for research productivity. Most of them related to human, financial, organisational, structural resources, and organizational culture. The novelty of our study lies in the insights into the middle management of universities in the scientific field of engineering and technology in light of the Positive Organisational Scholarship framework.

  • BEHAVIOR OF REINFORCED CONCRETE BEAMS CONTAINING LIGHTWEIGHT AGGREGATE IN THE TENSILE ZONE
    • Jamal Khatib
    • Ali Jahami
    • Oussama Baalbaki
    • Adel Elkordi
    • Hakim Abdelgader
    2020 Full text BAU Journal - Science and Technology

    .

  • Benchmarking Deep Neural Network Training Using Multi- and Many-Core Processors
    • Paweł Czarnul
    • Klaudia Jabłońska
    2020 International Journal of Computer Information Systems and Industrial Management Applications

    In the paper we provide thorough benchmarking of deep neural network (DNN) training on modern multi- and many-core Intel processors in order to assess performance differences for various deep learning as well as parallel computing parameters. We present performance of DNN training for Alexnet, Googlenet, Googlenet_v2 as well as Resnet_50 for various engines used by the deep learning framework, for various batch sizes. Furthermore, we measured results for various numbers of threads with ranges depending on a given processor(s) as well as compact and scatter affinities. Based on results we formulate conclusions with respect to optimal parameters and relative performances which can serve as hints for researchers training similar networks using modern processors.

  • Bennet
    • Luciano Segreto
    2020

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  • Beyond quid pro quo: good soldiers and characteristics of their helping behaviours
    • Joanna Szulc
    2020 Full text Personnel Review

    Purpose – Good soldiers are people who engage in citizenship behaviours “to do good” instead of “to look good”. The purpose of this article is to explore the motivations behind and the specific characteristics of behaviours of the good soldiers in the context of work using social exchange theory (SET) as a theoretical framework. Design/methodology/approach – 47 dyadic interviews with 94 individuals from three organisations where good soldiers are most likely to be observed were conducted. Findings – Data analysis revealed that good soldiers are driven by concern for others and generalised reciprocity, but not expectations of self-benefits. Their actions were further found to be discretionary, reactive and proactive, and associated with different levels of self-sacrifice. Practical implications – The findings of this study point human resources (HR) practitioners’ attention towards qualitatively unique acts of good soldiers. An assumption is made that awareness of such behaviours can help organisations to stimulate individual self-motivation, so that the quality of helping behaviours could be improved. Originality/value - Arguing for a fundamental rethink of the psychological foundations underpinning helpful behaviours, this paper departs from predominantly individualistic view on work motivation and reinforces the other-oriented, altruistic dimension of SET. In doing so, it addresses the lack of conceptual and theoretical clarity on differently motivated helping and extends the existing limited research evidence in this area. It further addresses a need for a comprehensive understanding of other-oriented behaviours and accounts for vital - yet neglected – features of such acts.

  • Bezpośrednie inwestycje zagraniczne Świat-Europa-Kaukaz-Polska
    • Krystyna Gomółka
    • Elżbieta Kacperska
    • Jakub Kraciuk
    • Michał Wojtaszek
    2020

    W ostatnich dziesięcioleciach bezpośrednie inwestycje zagraniczne należą do najbardziej dynamicznych strumieni międzynarodowych przepływów gospodarczych obok przepływów towarów i usług. Procesy liberalizacji i regionalizacji w dużej mierze przyczyniły się do rosnących przepływów bezpośrednich inwestycji zagranicznych w gospodarce światowej. Przemieszczanie się kapitału w skali międzynarodowej stało się jednym z głównych, i najbardziej pożądanych czynników rozwojowych wielu państwach. W 1970 r. wartość globalnych bezpośrednich inwestycji zagranicznych osiągnęła 13,2 mln USD, zaś w 2018 r. kwotę 1,3 bln USD. Napływ kapitału w postaci bezpośrednich inwestycji zagraniczny do różnych regionów świata cechuje silne zróżnicowanie. Głównymi kreatorami światowych przepływów są kraje rozwinięte, jednak w ostatnich latach dołączyły do tego grona państwa rozwijające się, których udział cały czas ulega wzrostowi. W ostatnich latach obserwujemy zmiany zarówno w strukturze geograficznej, jak też w strukturze rodzajowej bezpośrednich inwestycji zagranicznych. Niniejsze opracowanie jest próbą oceny uwarunkowań, stanu i kierunków zmian międzynarodowych przepływów kapitałowych nastawionych na analizę bezpośrednich inwestycji zagranicznych w ujęciu globalnym i regionalnym. Z uwagi na złożoność problematyki w pracy zawarto jedynie wybrane aspekty. W pierwszej kolejności ukazano teoretyczne przesłanki bezpośrednich inwestycji zagranicznych. Następnie naświetlono empiryczne aspekty bezpośrednich inwestycji zagranicznych w ujęciu globalnym. Ujęcie globalne odnosi się do analizy przepływów bezpośrednich inwestycji w skali świata. Ujęcie regionalne obejmuje analizę przepływów bezpośrednich inwestycji zagranicznych na terenie państw Kaukazu Południowego (Armenii, Azerbejdżanu i Gruzji) oraz na terenie Polski. Polskę przedstawiono jako przykład kraju, który dzięki inwestycjom dokonał znaczącej transformacji gospodarki. Doświadczenia te mogą być wykorzystane przez inne kraje, w tym państwa Kaukazu Południowego. Szczególnie mając na uwadze fakt, że bezpośrednie inwestycje zagraniczne w coraz większym stopniu są lokowane w krajach rozwijających się, w tym w analizowanych krajach Kaukazu Południowego, które mogą jeszcze dzięki inwestycjom zagranicznym wiele zyskać. Zatem przedstawione przykłady mogą być uznane za typowe dla wielu innych krajów na świecie.

  • Bezzałogowy kołowy pojazd elektryczny do automatycznego wychodzenia z poślizgów
    • Juliusz Ciecierski
    • Piotr Drewek
    • Adam Misiak
    • Robert Piotrowski
    2020 Full text Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej

    Pojazdy bezzałogowe znajdują zastosowanie w wielu dziedzinach współczesnego świata. Pojazdy autonomiczne wraz z algorytmami wspomagającymi kierowanie pojazdami skupiają uwagę wielu zespołów inżynierskich. Jednym z ważniejszych aspektów bezpieczeństwa na drogach jest wspomaganie zapobiegania i wychodzenia z poślizgów w dynamicznym środowisku. Artykuł przedstawia projekt oraz wykonanie bezzałogowego pojazdu kołowego zdolnego do automatycznego wychodzenia z poślizgów. Następnie pojazd oprogramowano oraz opracowano aplikację mobilną na urządzenia z systemem Android. Na koniec wykonano badania testowe opracowanego rozwiązania.

  • Będziesz lubić to, co lubisz
    • Jarosław Wawer
    2020 Elektronika dla wszystkich

    Felieton popularno-naukowy dotyczący powstawania baniek informacyjnych/baniek filtrujących.

  • Biblioteka PG uzyskała dofinansowanie z Ministerstwa Nauki i Szkolnictwa Wyższego
    • Kamila Kokot-Kanikuła
    2020 Pismo PG

    „Konserwacja, digitalizacja i udostępnienie 15 wol. zbiorów historycznych z kolekcji Biblioteki PG” to tytuł kolejnego projektu zakwalifikowanego do finansowania w ramach programu ogłoszonego przez Ministerstwo Nauki i Szkolnictwa Wyższego – Społeczna Odpowiedzialność Nauki. Biblioteka otrzyma wsparcie w wysokości 121 tys. zł, przy czym wartość całego przedsięwzięcia wyniesie 136,5 tys. zł.

  • Bidirectional Fragment to Fragment Links in Wikipedia
    • Szymon Olewniczak
    • Tomasz Boiński
    • Julian Szymański
    2020 Full text

    The paper presents a WikiLinks system that extends the Wikipedia linkage model with bidirectional links between fragments of the articles and overlapping links’ anchors. The proposed model adopts some ideas from the research conducted in a field of nonlinear, computer-aided writing, often called a hypertext. WikiLinks may be considered as a web augmentation tool but it presents a new approach to the problem that addresses the specific nature of Wikipedia. The system, rather than working on the HTML level, works on the wiki code level and augments the Wikipedia content on the parsing phase. WikiLinks is shipped with a new kind of wiki code parser – a parallel markup parser, that allows applying externally-stored links to the content in an elegant way. The system also addresses the problem of bidirectional links' anchors adjustments on the articles' changes, provides a special link evolution procedure and handles the link’s visibility problem. According to our knowledge, this is the first attempt that brings bidirectional links directly to Wikipedia. One of the possible applications of bidirectional fragment-fragment links are associative links. An associative link is a connection between two document fragments that are related to each other in some sense. The new link type extends the current Wikipedia linkage model, dominated by definitional links and provides us an additional tool for content organization, that might be useful for still-growing Wikipedia’s article base. The associative links are from their nature more subjective that definitional ones. In order to test the relevance of this new linkage model, we conducted experiment that checked if the associative links created by one person are understandable to others. The obtained results are very promising and show the usefulness of a new linkage model for Wikipedia.

  • BIG PROBLEMS WITH BIG DATA
    • Krzysztof Goczyła
    2020 Full text TASK Quarterly

    The article presents an overview of the most important issues related to the phenomenon called big data. The characteristics of big data concerning the data itself and the data sources are presented. Then, the big data life cycle concept is formulated. The next sections focus on two big data technologies: MapReduce for big data processing and NoSQL databases for big data storage.

  • Bioavailability of Tannins and Other Oligomeric Polyphenols: a Still to Be Studied Phenomenon
    • Naira Sahakyan
    • Agnieszka Bartoszek-Pączkowska
    • Jacob Claus
    • Margarit Petrosyan
    • Armen Trchounian
    2020 Current Pharmacology Reports

    Purpose of Review Polyphenols are a group of plant secondary metabolites characterized with the presence ofmultiples of phenol structural units. Tannins are plant originated phenolic substances, which play an important role in plant defense system as well as have found applications in medicine, industry, and other fields of human activity. Despite these, the mechanisms of bioavailability of these substances are poorly studied and even there are very few amounts of sources gathering recent studies concerning this issue. So the main purpose of this review is to focus on the known peculiarities and possible ways of the bioavailability of these oligomeric substances. Recent Findings Due to the ability of tannins to bind proteins and other macromolecules, they are responsible for astringency or bitterness of red wines and also for the anti-nutritional effects, which can be reduced by the action of tannase. In nutriceutical industry, tannins are used as natural preservers and antioxidants. They have also a wide range of medicinal application as antihemorrhagic and hemostatic, anti-malarial and antitumor, antimicrobial, antioxidant, anti-tyrosinase, anthelmintic, antiviral, and anti-inflammatory activities among others. It is suggested that absorption of tannins is correlatedwith their polymerization degree and the activity of these components depends on their absorption in the gut, metabolism and, therefore, the bioavailability. Summary Despite numerous promising applications, there are still plenty of open spaces to fully understand determinants of the bioavailability of tannins and other oligomeric polyphenols pivotal for the expression of their biological activity.

  • Bio-Based Polyurethane Composites and Hybrid Composites Containing a New Type of Bio-Polyol and Addition of Natural and Synthetic Fibers
    • Adam Olszewski
    • Paulina Kosmela
    • Aleksandra Mielewczyk-Gryń
    • Łukasz Piszczyk
    2020 Full text Materials

    This article describes how new bio-based polyol during the liquefaction process can be obtained. Selected polyol was tested in the production of polyurethane resins. Moreover, this research describes the process of manufacturing polyurethane materials and the impact of two different types of fibers—synthetic and natural (glass and sisal fibers)—on the properties of composites. The best properties were achieved at a reaction temperature of 150 °C and a time of 6 h. The hydroxyl number of bio-based polyol was 475 mg KOH/g. Composites were obtained by hot pressing for 15 minutes at 100 °C and under a pressure of 10 MPa. Conducted researches show the improvement of flexural strength, impact strength, hardness, an increase of storage modulus of obtained materials, and an increase of glass transition temperature of hard segments with an increasing amount of fibers. SEM analysis determined better adhesion of sisal fiber to the matrix and presence of cracks, holes, and voids inside the structure of composites.

  • Bioelectronic tongue: Current status and perspectives
    • Wasilewski Tomasz
    • Wojciech Kamysz
    • Jacek Gębicki
    2020 BIOSENSORS & BIOELECTRONICS

    In the course of evolution, nature has endowed humans with systems for the recognition of a wide range of tastes with a sensitivity and selectivity which are indispensable for the evaluation of edibility and flavour attributes. Inspiration by a biological sense of taste has become a basis for the design of instruments, operation principles and parameters enabling to mimic the unique properties of their biological precursors. In response to the demand for fast, sensitive and selective techniques of flavouring analysis, devices belonging to the group of bioelectronic tongues (B-ETs) have been designed. They combine achievements of chemometric analysis employed for many years in electronic tongues (ETs), with unique properties of bio-inspired materials, such as natural taste receptors (TRs) regarding receptor/ligand affinity. Investigations of the efficiency of the prototype devices create new application possibilities and suggest successful implementation in real applications. With advances in the field of biotechnology, microfluidics and nanotechnologies, many exciting developments have been made in the design of B-ETs in the last five years or so. The presented characteristics of the recent design solutions, application possibilities, critical evaluation of potentialities and limitations as well as the outline of further development prospects related to B-ETs should contribute to the systematisation and expansion of our knowledge.

  • Biogenne aminy
    • Edyta Malinowska-Pańczyk
    2020

    W rozdziale omówiono zagadnienia związane z powstawaniem biogennych amin w surowcach i produktach żywnościowych oraz ich wpływ na zdrowie konsumentów.

  • Biological and mechanical properties of bone cement with nanoarticles - in vitro and in vivo research
    • Beata Świeczko-Żurek
    • Marcin Wekwejt
    • Anita Kajzer
    • Wojciech Kajzer
    • Karolina Siwicka
    • Antonio Ramos
    • Michel Mesnard
    • Jean-marc Olive
    2020 Journal of Mechanical Engineering and Biomechanics

    Despite antibiotic preventive treatment both before and after implant implementation, the risks of infection are real. These infections develop at the implant surface a few months after inserting them into the body. To prevent the development of bacteria and reduce the risk of infection, implants coated with nanoparticles are used. The Mechanical Department of the Technical University of Gdansk carries out research into using bone cement and metal nanoparticles as an alternative to antibiotics [1-3]. Until now, bone cement has been used without a supplement or with one or two drugs. These new experiments included pure bone cement with nanometals, without drugs. The titanium specimens were covered with nanometal coatings. Specimens were inserted into a rat`s thigh for six weeks. The implant was then removed from the body and examined by scanning electron microscope. The results were positive: there was a good adhesion of osteoblasts on the implant surface and there were no traces of infection. Biological research was also carried out. Boneless samples were placed into a bacterial liquid generated by the researcher which contained the five most common bacteria in the human body (Patent no. P409082). Mechanical and corrosion research was carried out at the same time. This confirmed that the modification of bone cement using nanometals has no significant negative effect on the setting time of bone cement, or on the hardness and value of contact angle. In addition, the bone cement coating (with or without nanometals) improved corrosion resistance.

  • Biomateriały we współczesnej medycynie
    • Karolina Czarnecka
    • Mateusz Siwiak
    • Justyna Kucińska-Lipka
    • Jacek Zieliński
    • Helena Janik
    • Michał Pikuła
    2020

    Biomedycyna oznacza eksperymentalne biologiczne i medyczne nauki zintegrowane w całość, w tym nauki chemiczne o związkach wielkocząstoczkowych.

  • Bioterroryzm we współczesnym świecie
    • Marcin Żurek
    • Beata Świeczko-Żurek
    2020

    W definicji wojny biologicznej ważne są słowa dotyczące zastosowania osiągnięć nauki, ponieważ do świadomego i celowego korzystania z broni biologicznej wymagane jest zrozumienie choroby. Gwałtowny rozwój nauk biologicznych i towarzyszące mu liczne odkrycia doprowadziły do większego zainteresowania się bronią biologiczną. Doskonalono techniki hodowli i izolacji kultur mikrobiologicznych. Artykuł opisuje czym jest bioterroryzm i jakie są rodzaje broni biologicznej.

  • Bismuth-Doped Nano Zerovalent Iron: A Novel Catalyst for Chloramphenicol Degradation and Hydrogen Production
    • Murtaza Sayed
    • Aamir Khan
    • Sajid Rauf
    • Noor S. Shah
    • Faiza Rehman
    • Abdullah A. Al-Kahtani
    • Javed Khan
    • Jibran Iqbal
    • Grzegorz Boczkaj
    • Ikhtiar Gul
    • Maleeha Bushra
    2020 Full text ACS Omega

    In this study, we showed that doping bismuth (Bi) at the surface of Fe0 (Bi/Fe0, bimetallic iron system)—synthesized by a simple borohydride reduction method—can considerably accelerate the reductive degradation of chloramphenicol (CHP). At a reaction time of 12 min, 62, 68, 74, 95, and 82% degradation of CHP was achieved with Fe0, Bi/Fe0-1 [1% (w/w) of Bi], Bi/Fe0-3 [3% (w/w) of Bi], Bi/Fe0-5 [5% (w/w) of Bi], and Bi/Fe0-8 [8% (w/w) of Bi], respectively. Further improvements in the degradation efficiency of CHP were observed by combining the peroxymonosulfate (HSO5–) with Bi/Fe0-5 (i.e., 81% by Bi/Fe0-5 and 98% by the Bi/Fe0-5/HSO5– system at 8 min of treatment). Interestingly, both Fe0 and Bi/Fe0-5 showed effective H2 production under dark conditions that reached 544 and 712 μM by Fe0 and Bi/Fe0-5, respectively, in 70 mL of aqueous solution containing 0.07 g (i.e., at 1 g L–1 concentration) of the catalyst at ambient temperature.

  • Blood Pressure - Pulse Transit Time Relationships: Comparative Studies
    • Artur Poliński
    • Adam Bujnowski
    • Tomasz Kocejko
    • Jerzy Wtorek
    2020

    A non-invasive and continuous blood pressure estimation could allow a better diagnosis and an earlier detection of various diseases. It could be performed using a photoplethysmography. However, it requires that a relation between blood pressure and pulse transit time is known. Eleven theoretical formulas were used in obtaining the simulated and noise free synthetic data. Then, they were utilized in validation of three, commonly used, formulas for blood pressure estimation. Finally, the best one was indicated

  • Blowing Kinetics, Pressure Resistance, Thermal Stability, and Relaxation of the Amorphous Phase of the PET Container in the SBM Process with Hot and Cold Mold. Part I: Research Methodology and Results
    • Paweł Wawrzyniak
    • Waldemar Karaszewski
    2020 Full text Polymers

    The technology of filling drinks without preservatives (such as fresh juices, iced tea drinks, vitaminized drinks) is carried out using hot filling. Mainly due to the production costs and lower carbon footprint, polyethylene terephthalate bottles, commonly called PET, are increasingly used in this technology. In this paper, the main aim is to describe the statistical analysis methodology of the influence of the temperature of the blow mold in the SBM process and the method of hot filling on the macroscopic and microscopic bottle properties. The macroscopic bottle properties were defined by the thickness profile, pressure resistance, thermal stability, and the coefficients of blowing kinetics. Moreover, the influence of the SBM (stretch blow moulding) process on the microscopic PET material properties (in the bottle) relative to the microscopic preform properties was analyzed. The microscopic properties were defined by the degree of crystallite, density, and relaxation of the amorphous phase of the PET material. For this purpose, response surface experiments were performed for the two analyzed factors (independent variables), i.e., the temperature of the blow mold and the method of hot filling. The sample size was investigated to determine the minimum number of repetitions (number of bottles in the measurement series) required to achieve acceptable measurement uncertainty. The research conducted shows that despite fulfilling the postulate of acceptable measurement uncertainty, in terms of the power of ANOVA (analysis of variance) in DOE (design of experiment) the accepted number of bottles in the measurement series is too small. The tests of the bottle material density, material crystallite, and relaxation of amorphous phase relative to the preform material density, material crystallite, and relaxation of amorphous phase show that the microcavity effects occur during the deformation of the PET material, and that these are associated with the orientation of the microstructure. The blow kinetics study shows that there is a gradient of flow of the bottle material over the thickness of the bottle wall during blowing, and it has been deduced that the air temperature between the blow mold and the wall of the blown bottle has an impact on the kinetics of blowing the bottle.

  • Blowing Kinetics, Pressure Resistance, Thermal Stability, and Relaxation of the Amorphous Phase of the PET Container in the SBM Process with Hot and Cold Mold. Part II: Statistical Analysis and Interpretation of Tests
    • Paweł Wawrzyniak
    • Waldemar Karaszewski
    2020 Full text Polymers

    The technology of filling drinks without preservatives (such as fresh juices, iced tea drinks, and vitaminized drinks) is carried out using hot filling. Mainly due to the production costs and lower carbon footprint, polyethylene terephthalate (PET) bottles are increasingly used in this technology. In this paper, the main aim is to describe and interpret the results of statistical analysis of the influence of the temperature of the blow mold in the SBM (stretch blow molding) process and the method of hot filling on the macroscopic and microscopic bottle properties. The macroscopic bottle properties were defined by the thickness profile, pressure resistance, thermal stability, and the coefficients of blowing kinetics. In addition, the influence of the SBM process on the microscopic PET material properties (in the bottle) relative to the microscopic preform properties was analyzed. The microscopic properties were defined by the degree of crystallite, density, and relaxation of the amorphous phase of the PET material. For this purpose, response surface experiments were performed for the two analyzed factors, i.e. the temperature of the blow mold and the method of hot filling. The sample size was investigated to determine the minimum number of repetitions (number of bottles in the measurement series) required to achieve acceptable measurement uncertainty. The research conducted shows that, despite fulfilling the postulate of acceptable measurement uncertainty, in terms of the power of ANOVA (analysis of variance) in DOE (design of experiment), the accepted number of bottles in the measurement series is too small. The tests of the bottle material density, material crystallite, and relaxation of amorphous phase relative to the preform material density, material crystallite, and relaxation of amorphous phase show that microcavity effects occur during the deformation of the PET material, and that these are associated with the orientation of the microstructure. The blow kinetics study shows that there is a gradient of flow of the bottle material over the thickness of the bottle wall during blowing, and it has been deduced that the air temperature between the blow mold and the wall of the blown bottle has an impact on the kinetics of blowing the bottle.

  • Blurred quantum Darwinism across quantum reference frames
    • Thao P. Le
    • Piotr Mironowicz
    • Paweł Horodecki
    2020 Full text PHYSICAL REVIEW A

    Quantum Darwinism describes objectivity of quantum systems via their correlations with their environment--information that hypothetical observers can recover by measuring the environments. However, observations are done with respect to a frame of reference. Here, we take the formalism of [Giacomini, Castro-Ruiz, & Brukner. Nat Commun 10, 494 (2019)], and consider the repercussions on objectivity when changing quantum reference frames. We find that objectivity depends on non-degenerative relative separations, conditional state localisation, and environment macro-fractions. There is different objective information in different reference frames due to the interchangeability of entanglement and coherence, and of statistical mixing and classical correlations. As such, objectivity is subjective across quantum reference frames.

  • Bounded solutions of odd nonautonomous ODE
    • Zdzisław Dzedzej
    2020 Full text TOPOLOGY AND ITS APPLICATIONS

    Borsuk-Ulam type argument is used in order to prove exstence of nontrivial bounded solutions to some nonautonomous differential euations which are odd with respect to the spatial variable. A Poincare compactification trick is also applied.

  • BPL-PLC Voice Communication System for the Oil and Mining Industry
    • Grzegorz Debita
    • Przemysław Falkowski-Gilski
    • Marcin Habrych
    • Grzegorz Wiśniewski
    • Bogdan Miedziński
    • Przemysław Jedlikowski
    • Agnieszka Waniewska
    • Jan Wandzio
    • Bartosz Polnik
    2020 Full text ENERGIES

    Application of a high-efficiency voice communication systems based on broadband over power line-power line communication (BPL-PLC) technology in medium voltage networks, including hazardous areas (like the oil and mining industry), as a redundant mean of wired communication (apart from traditional fiber optics and electrical wires) can be beneficial. Due to the possibility of utilizing existing electrical infrastructure, it can significantly reduce deployment costs. Additionally, it can be applied under difficult conditions, thanks to battery-powered devices. During an emergency situation (e.g., after coal dust explosion), the medium voltage cables are resistant to mechanical damage, providing a potentially life-saving communication link between the supervisor, rescue team, paramedics, and the trapped personnel. The assessment of such a system requires a comprehensive and accurate examination, including a number of factors. Therefore, various models were tested, considering: different transmission paths and types of coupling (inductive and capacitive), as well as various lengths of transmitted data packets. Next, a subjective quality evaluation study was carried out, considering speech signals from a number of languages (English, German, and Polish). Based on the obtained results, including both simulations and measurements, appropriate practical conclusions were formulated. Results confirmed the applicability of BPL-PLC technology as an efficient voice communication system for the oil and mining industry.

  • Bridge of Knowledge: an Internet platform for R2R and R2B transfer of knowledge and promotion of cooperation
    • Henryk Krawczyk
    • Paweł Lubomski
    2020 Full text TASK Quarterly

    Currently, the European Commission puts emphasis on supporting collaboration between universities and business. There are many possible ways to create a strong relationship between both these parties. Positive results of such cooperation lead to increased competitiveness of the global market and, in consequence, bring significant growth of innovation. The cooperation between research-to-research (R2R) and research-to-business (R2B) is analysed. The paper shows how the IT technology can be used to support and stimulate it. In our University we proposed a two-step strategy. Firstly, we tried to improve collaboration among scientists in order to develop R2R activities. Secondly, we focused on R2B projects that stimulate promising scientists to take part in various innovative activities carried out in cooperation with the industry representatives. Based on some well-known good practices a special Internet platform was designed and implemented to support such a strategy. Its name is the “Bridge of Knowledge”. The platform architecture, its functionality and some other aspects of the development process are described. The platform was developed and introduced at the Gdańsk University of Technology. It has been available online for nearly 2 years now and it has been attracting increasing numbers of new visitors and returning users. Several use cases of cooperation between R2R and R2B were analysed and described with the use of advanced analytic tools and on the basis of the organisation’s resources. The idea of the Bridge of Knowledge platform is to gather and share resources not only from one university. The architecture of the platform focuses on a wide and easy interoperability. Other universities can share their resources without any additional cost.