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Politechniki Gdańskiej

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Publikacje z roku 2015

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  • Fractional-order Systems and Synchronous Generator Voltage Regulator
    • Wojciech Lubośny
    • Zbigniew Lubośny
    2015 Pełny tekst Acta Energetica

    Modern regulators of synchronous generators, including voltage regulators, are digital systems, in their vast majority with standard structures contained in the IEEE standard. These are systems described with stationary differential equations of integral order. Differential equations of fractional order are not employed in regulators for synchronous generator control. This paper presents an analysis of the possibilities of using a system of fractional differential equations in the voltage regulator of an synchronous generator with a static excitation system.

  • Fragmentation of Tetrahydrofuran Molecules by H+, C+, and O+ Collisions at the Incident Energy Range of 25–1000 eV
    • Tomasz Wąsowicz
    • Bogusław Pranszke
    2015 JOURNAL OF PHYSICAL CHEMISTRY A

    We have studied fragmentation processes of the gas-phase tetrahydrofuran (THF) molecules in collisions with the H+, C+, and O+ cations. The collision energies have been varied between 25 and 1000 eV and thus covered a velocity range from 10 to 440 km/s. The following excited neutral fragments of THF have been observed: the atomic hydrogen H(n), n = 4–9, carbon atoms in the 2p3s 1P1, 2p4p 1D2, and 2p4p 3P states and vibrationally and rotationally excited diatomic CH fragments in the A2Δ and B2Σ– states. Fragmentation yields of these excited fragments have been measured as functions of the projectile energy (velocity). Our results show that the fragmentation mechanism depends on the projectile cations and is dominated by electron transfer from tetrahydrofuran molecules to cations. It has been additionally hypothesized that in the C++THF collisions a [C–C4H8O]+ complex is formed prior to dissociation. The possible reaction channels involved in fragmentation of THF under the H+, C+, and O+ cations impact are also discussed.

  • Frequency Guided Generalized Adaptive Notch Filtering - Tracking Analysis and Optimization
    • Michał Meller
    2015 IEEE TRANSACTIONS ON SIGNAL PROCESSING

    Generalized adaptive notch filters (GANFs) are estimators of coefficients of quasi-periodically time-varying systems, encountered e.g., in RF applications when Doppler effect takes place. Current state of the art GANFs can deliver highly accurate estimates of system variations’ frequency, but underperform in terms of accuracy of system coefficient estimates. The paper proposes a novel multistage GANF with improved coefficient tracking properties and smaller sensitivity to choice of estimation gains. The processing pipeline consists of three stages. First, a pilot filter computes preliminary frequency estimates. Second, a special linear filter reshapes the pilot frequency estimates. Third, a frequency guided GANF works out final estimates of system coefficients. A nontrivial design of the second stage filter assures that the proposed solution has a considerably better performance than current stage of the art solutions or a simpler two-stage approach consisting of the pilot and the frequency guided filter only.

  • Friction and Lubrication of Large Tilting-Pad Thrust Bearings
    • Michał Wasilczuk
    2015 Pełny tekst Lubricants

    Fluid film bearings have been extensively used in the industry because of their unbeatable durability and extremely low friction coefficient, despite a very low coefficient of friction dissipation of energy being noticeable, especially in large bearings. Lubricating systems of large tilting pad thrust bearings utilized in large, vertical shaft hydrogenerators are presented in this paper. A large amount of heat is generated due to viscous shearing of the lubricant large tilting pad thrust bearings, and this requires systems for forced cooling of the lubricant. In the dominant bath lubrication systems, cooling is realized by internal coolers or external cooling systems, with the latter showing some important advantages at the cost of complexity and also, potentially, lower reliability. Substantial losses in the bearings, reaching 1 MW in extreme cases, are a good motivation for the research and development aimed at reducing them. Some possible methods and their potential efficiency, along with some effects already documented, are also described in the paper.

  • Friction-Induced Oscillations of a Non-Asbestos Organic Pin Sliding on a Steel Disc
    • Oleksii Nosko
    • Takuo Nagamine
    • Hiroki Mori
    • Yuichi Sato
    2015 Pełny tekst Acta Mechanica et Automatica

    Friction-induced oscillations result in deterioration of performance of disc brakes and are generally undesired. We conduct experimental study of friction-induced oscillations in a non-asbestos organic material / steel pair used in disc brakes of motor vehicles. The tests are done by use of a pin-on-disc machine which has the pin sample supported on a deformable beam. The adjustable friction parameters are the disc velocity, contact pressure and temperature. The tests show that the friction coefficient decreases with the sliding velocity and increases with the temperature. The friction-induced tangential oscillation of the pin sample occurs with a frequency equal to the first natural frequency of the beam. The effects of the disc velocity and temperature on the oscillation characteristics are investigated. The oscillation amplitude increases with the disc velocity on the interval of velocities below 2 m/s. Temperature change of several tens of degrees Celsius can result in the oscillation occurrence / decay. The obtained results can be useful for prognostication of friction-induced oscillations in disc brakes with non-asbestos organic pads.

  • From hobbies, straightforward analysis to serious research – the road to phd degree
    • Katarzyna Bobkowska
    2015

    The illustration of the main articles goal is an example of author's academic career course, the aim of which is to obtain a doctoral degree in the field of geodesy and cartography. Today, the most important thing for the young scientist is the devotion to research in certain field of science, which is interested for the large community of scientists. From a psychological point of view, a unity of interest and experiments must characterized work of a young scientist. The article focuses on describing innovative research which is maintained independently by the PhD student and research conducted on the rest of the team. Multidisciplinary interests of the author (photogrammetry, remote sensing, computer vision, biometrics and psychology) have become the source of many interesting and innovative ideas that can find their application in a remote diagnosis of emotions, identifying people, whether the fight against terrorism. In addition, it describes the importance of cooperation and motivation to achieve individual and common purpose. Attention was drawn to the possibilities and limitations faced by the young researcher. The aspect of continuity of research topics from the beginning an academic career has been also addresses.

  • Functionalization of indium-tin-oxide electrodes by laser-nanostructured gold thin films for biosensing applications
    • Katarzyna Grochowska
    • Katatrzyna SiuzdaK
    • Jakub Karczewski
    • Gerard Śliwiński
    2015 APPLIED SURFACE SCIENCE

    of a relatively large area formed by pulsed laser nanostructuring of thin gold films arereported and discussed. The SEM inspection of modified electrodes reveals the presence of the nearlyspherical and disc-shaped particles of dimensions in the range of 40–120 nm. The NP-array geometry canbe controlled by selection of the laser processing conditions. It is shown that particle size and packingdensity of the array are important factors which determine the electrode performance. In the case ofNP-modified electrodes the peak current corresponding to the glucose direct oxidation process showsrise with increasing glucose concentration markedly higher comparing to the reference Au disc electrode.The detection limit reaches 12 M and linear response of the sensor is observed from 0.1 to 47 mM thatcovers the normal physiological range of the blood sugar detection.© 2015 Elsevier B.V. All rights reserved.1. IntroductionThe importance of nanomaterials for science and technologysteadily increases during last decades. The noble metal nanopar-ticles

  • Functioning and legal regulations of perpetual usufruct right in Poland in relation to similar rights in other countries of the European Union
    • Paweł Wysocki
    2015

    1 May 2004, Poland became part of the European Union, which main aim is the political, economic and social integration of democratic European countries as well as the construction of a common market ensuring of persons, goods, services and capital move freely. The Accession Treaty provides some transitional periods for the adjustment of the right of Member States to the EU regulations. Next year, 12 years after joining the EU, will be abolished restrictions on the acquisition of real property in Poland by citizens and entrepreneurs of the European Economic Area (EEA) and the Swiss Confederation (Confoederatio Helvetica). In addition to the ownership, there is in Poland the so-called perpetual usufruct right, which is an intermediate form between ownership and limited property rights. It allows for long-term use of the land which is not our ownership. Makes it possible to mortgage a property, is transferable and inheritable. The article describes the legal regulations governing the establishment and functioning of the perpetual usufruct, and the conditions under which it is possible to transform it into full ownership. The paper presents a comparison of other similar rights existing in developed market economies inter alia Great Britain, Germany, the Netherlands and Sweden related to long-term lease of land (leasehold). The publication presents the pros and cons of this right, both from the point of view of the perpetual user, as well as the owner and the impact of its use on real estate, spatial planning and economy.

  • Fundamentowanie obiektów mostowych na palach żelbetowych
    • Adam Krasiński
    2015 Pełny tekst Budownictwo Mostowe : Vademecum

    Ogólna charakterystyka posadowień na palach obiektów mostowych. Zasady wyboru rodzaju i technologii pali do warunków gruntowych i parametrów obiektu. Wskazówki dotyczące obliczania i projektowania fundamentów palowych podpór mostowych.

  • Fundusze UE w Gdańsku w latach 2004–2013 i ich wpływ na rozwój funkcji metropolitalnych
    • Dorota Dominika Kamrowska-Załuska
    2015

    Trudno przecenić rolę funduszy Unii Europejskiej i ich wpływ na rozwój funkcji metropolitalnych w Polsce. Dużą część tych funduszy przeznacza się na inwestycje infrastrukturalne, co spowodowane jest wieloletnimi zapóźnieniami. Jednocześnie coraz większa waga przykładana jest do znaczenia jakie polityka spójności UE powinna odgrywać w podnoszeniu konkurencyjności i jakości życia w metropoliach. Rozdział opisuje rola funduszy europejskich we wzmacnianiu funkcji metropolitalnych i ich wpływ na rozwój polskich miast na przykładzie Gdańska. W pierwszej części omówiono politykę miejską i jej powiązanie z polityką spójności Unii Europejskiej oraz priorytety działań współfinansowanych przez jednostki samorządu terytorialnego. W następnej przeanalizowano rozwój funkcji metropolitalnych przy wsparciu funduszy Unii Europejskiej w Gdańsku. Miast to, jako najważniejszy ośrodek północnej Polski, jest w ostatnich latach miejscem powstania wielu inwestycji wzmacniających metropolitalny jego charakter i wpływających na rozwój całej metropolii. Wyraźnie widać tworzenie się w przestrzeni sieci silnych usług metropolitalnych, mających zwiększyć konkurencyjność tego obszaru. W rozdziale szczegółowo przebadane zostały przykłady inwestycji z dziedziny kultury, sportu i rekreacji, takie jak: Gdańskie Centrum Muzyczno-Kongresowe, Europejskie Centrum Solidarności oraz Ergo Arena.

  • Funkcjonowanie lądowego transportu ładunków w otoczeniu portów Morskich Morza Bałtyckiego z perspektywy uwarunkowań miejskich i regionalnych
    • Daniel Kaszubowski
    2015

    Lądowa dostępność transportowa współczesnych portów morskich odgrywa coraz istotniejsza rolę w kształtowaniu rozwiązań logistycznych zgodnych z rosnącymi wymaganiami klientów. Konkurencyjność portów morskich jest coraz częściej postrzegana z perspektywy jakości ich infrastrukturalnych oraz organizacyjnych powiązań z zapleczem oraz poziomu integracji funkcji portowych z otoczeniem miejskim i regionalnym, co warunkuje możliwość aktywnego kształtowania ich potencjału. Znaczenie efektywności logistycznej obsługi zaplecza jest szczególnie ważne w odniesieniu do portów Regionu Morza Bałtyckiego. Ze względu na lokalizację i charakter usług bardzo często konkurują one ze sobą o pozyskanie klientów na ograniczonym geograficznie rynku. Z tego powodu coraz częściej podejmowane są aktywne działania integracyjne pomiędzy portami morskimi a uczestnikami łańcuchów logistycznych. Ważną rolę w tym systemie odgrywa otoczenie portów, zlokalizowanych najczęściej w bezpośrednim sąsiedztwie obszarów miejskich. Działalność transportowa i logistyczna nie jest obojętna dla otoczenia, stąd w obszarach jej koncentracji niezbędne jest podejmowanie przemyślanych działań służących ograniczeniu jej niepożądanego oddziaływania w postaci hałasu, degradacji infrastruktury, emisji szkodliwych substancji itp. Zastosowanie znajdą tu narzędzia stosowane w zarządzaniu transportem ładunków w miastach (środki logistyki miejskiej) oraz inne rozwiązania dostosowane do specyfiki lądowo-morskich łańcuchów logistycznych. Ich racjonalna kombinacja może pozwolić na poprawę efektywności wykorzystania dostępnych zasobów infrastrukturalnych i zwiększenie niezawodności transportu. Większość z analizowanych rozwiązań dotyczy drogowego transportu ładunków jako posiadającego największy udział w obsłudze działalności portowej. Z uwagi na charakterystykę wykorzystywanych technologii transportowych jego oddziaływanie jest jednocześnie najbardziej uciążliwe dla mieszkańców.

  • Future research directions in design of reliable communication systems
    • Jacek Rak
    • Mario Pickavet
    • Kishor S. Trivedi
    • Javier Alonso Lopez
    • Arie M. C. A. Koster
    • James P.G. Sterbenz
    • Egemen Çetinkaya
    • Teresa Gomes
    • Matthias Gunkel
    • Krzysztof Walkowiak
    • Dimitri Staessens
    2015 Pełny tekst TELECOMMUNICATION SYSTEMS

    In this position paper on reliable networks, we discuss new trends in the design of reliable communication systems. We focus on a wide range of research directions including protection against software failures as well as failures of communication systems equipment. In particular, we outline future research trends in software failure mitigation, reliability of wireless communications, robust optimization and network design, multilevel and multirealm network resilience, multiple criteria routing approaches in multilayer networks, resilience options of the fixed IP backbone network in the interplay with the optical layer survivability, reliability of cloud computing networks, and resiliency of software-defined networks. Described research directions are frequently enhanced with examples.

  • Games and play with light in architecture
    • Małgorzata Rogińska-Niesłuchowska
    2015 Pełny tekst Czasopismo Techniczne

    The paper deals with the issue of the influence of daylight on the creation of architecture in the view of designers` play with light in the architectural space. Using the examples of contemporary realizations of some art museums, the work demonstrates the impact of exploration and experimentation conducted by the creators of visual arts on the design styles and architectural solutions. It also reveals the historical continuity of the use of light manipulation in architecture.

  • Gamma oscillations precede interictal epileptiform spikes in the seizure onset zone
    • Liankun Ren
    • Michał Tomasz Kucewicz
    • Jan Cymbalnik
    • Joseph Matsumoto
    • Benjamin H. Brinkmann
    • Wei Hu
    • W. Richard Marsh
    • Frederic Meyer
    • S. Matthew Stead
    • Gregory A. Worrell
    2015 NEUROLOGY

    OBJECTIVE: To investigate the generation, spectral characteristics, and potential clinical significance of brain activity preceding interictal epileptiform spike discharges (IEDs) recorded with intracranial EEG. METHODS: Seventeen adult patients with drug-resistant temporal lobe epilepsy were implanted with intracranial electrodes as part of their evaluation for epilepsy surgery. IEDs detected on clinical macro- and research microelectrodes were analyzed using time-frequency spectral analysis. RESULTS: Gamma frequency oscillations (30-100 Hz) often preceded IEDs in spatially confined brain areas. The gamma-IEDs were consistently observed 35 to 190 milliseconds before the epileptiform spike waveforms on individual macro- and microelectrodes. The gamma oscillations associated with IEDs had longer duration (p < 0.001) and slightly higher frequency (p = 0.045) when recorded on microelectrodes compared with clinical macroelectrodes. Although gamma-IEDs comprised only a subset of IEDs, they were strongly associated with electrodes in the seizure onset zone (SOZ) compared with the surrounding brain regions (p = 0.004), in sharp contrast to IEDs without preceding gamma oscillations that were often also detected outside of the SOZ. Similar to prior studies, isolated pathologic high-frequency oscillations in the gamma (30-100 Hz) and higher (100-600 Hz) frequency range, not associated with an IED, were also found to be associated with SOZ. CONCLUSIONS: The occurrence of locally generated gamma oscillations preceding IEDs suggests a mechanistic role for gamma in pathologic network activity generating IEDs. The results show a strong association between SOZ and gamma-IEDs. The potential clinical application of gamma-IEDs for mapping pathologic brain regions is intriguing, but will require future prospective studies.

  • Gas selectivity enhancement by sampling-and-hold method in resistive gas sensors
    • Janusz Smulko
    • Maciej Trawka
    2015 Pełny tekst SENSORS AND ACTUATORS B-CHEMICAL

    Commercial resistive gas sensors exhibit various sensitivity to numerous gases when working at different elevated temperatures. That effect is due to a change in velocity of adsorption and desorption processes which can be modulated by temperature. Thus, to reach better selectivity of gas detection, we propose to apply a known method (called the sampling-and-hold method) of cooling down the gas sensor in the presence of the investigated gas, and the fluctuation enhanced sensing. The adsorbed gas molecules were captured in the porous gas sensing layer and then slowly released by heating up. We observed a significant (greater than one order) change of the normalized low-frequency resistance noise during the process of slow heating up. That change was characteristic for different investigated gases. Moreover, the resistance noise reached its minimum at the temperature characteristic for the adsorbed gas. This effect can be explained by differences in the activation energy of the adsorbed gas molecules. The observed results are very promising for improving gas detection by determining the position of minimal noise intensity and can be utilized in practice.

  • Gazowa mikrosiłownia domowa z modułem ORC - doświadczenia z badania prototypu
    • Jan Wajs
    • Dariusz Mikielewicz
    2015 Technika Chłodnicza i Klimatyzacyjna

    Artykuł zawiera rozważania nad ideą wykorzystania obiegu parowego ORC (Organic Rankine Cycle) do skojarzonej produkcji ciepła i energii elektrycznej dla pokrycia potrzeb indywidualnego odbiorcy. Dokonano w nim podsumowania dotychczasowych prac prowadzonych przez Autorów, które zaowocowały budową demonstracyjno-badawczego stanowiska mikro-CHP z technologią ORC w skali „domowej”, współpracującą z komercyjnym kotłem gazowym. W publikacji przedstawiono charakterystykę techniczną zaprojektowanego i wykonanego na Politechnice Gdańskiej stanowiska mikrosiłowni ORC. Na tym tle omówiono autorskie konstrukcje wymienników ciepła i turbogeneratora. W końcowej części artykułu przywołano wybrane wyniki badań doświadczalnych prototypu, wykazując atrakcyjność jednostki i potrzebę prowadzenia dalszych prac dla usprawnienia jej pracy. Przedstawiony prototyp mikrosiłowni zyskał duży rozgłos w środowiskach naukowych (również za granicą) rozwijających urządzenia kogeneracyjne dla sektora energetyki rozproszonej.

  • Gdańsk palimpsest. On obscuring and retrieving traces of memory
    • Małgorzata Dymnicka
    • Jakub Szczepański
    2015 Forum Socjologiczne

    The article deals with the problems of collective identity resulting from over one thousand year history of the city on the Motława river and the role of historical policy of the local authorities regarding the material cultural heritage of many nations and cultures. In our opinion, the palimpsestic (palimpsestueuse) character of the city plays a significant role in the discourse about the past of Gdańsk. We use that notion after Philippe Lejeune to emphasize the complexity of the process of accumulating, obscuring, deciphering and “domesticating” the subsequent layers and activities leading to the creation of new spaces and new urban myths.

  • Gdańsk Shakespeare Theatre
    • Monika Arczyńska
    2015

    Text on Gdańsk Shakespeare Theatre.

  • Gdański student- to znaczy kto? Rzecz o tożsamości młodych w przestrzeni miejskiej
    • Paweł Bykowski
    2015

    Artykuł opisuje poczucie tożsamości gdańskich studentów z przestrzenią miejską. Opisuje odczucia oraz postawy względem najbliższej im przestrzeni zamieszkiwanego terenu miejskiego.

  • Gdański Teatr Szekspirowski
    • Monika Arczyńska
    2015

    Tekst o Gdańskim Teatrze Szekspirowskim.