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Gdańsk University of Technology

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Publications from the year 2014

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  • Ulepszone podłoże gruntowe i dolne warstwy konstrukcji nawierzchni
    • Marek Pszczoła
    • Jacek Alenowicz
    • Mariusz Jaczewski
    • Marcin Stienss
    • Józef Judycki
    2014

    Analityczne opracowanie wyjaśniające zasady weryfikacji i aktualizacji obliczeń zawartych w nowym katalogu typowych konstrukcji nawierzchni podatnych i półsztywnych z 2013 roku dostosowanym do współczesnych technologii i materiałów, zwiększonego obciążenia dróg przez ruch drogowy, zmienionych sposobów wzmacniania podłoża, recyklingu materiałów drogowych, ujednoliconego nazewnictwa warstw konstrukcji nawierzchni oraz nowych metod obliczeń konstrukcji nawierzchni. Zawiera również porównanie katalogów typowych nawierzchni z Austrii, Francji, Niemiec i Wielkiej Brytanii z katalogiem polskim.

  • Ultrashort Opposite Directed Pulses Dynamics with Kerr Effect and Polarization Account
    • Mateusz Kuszner
    • Sergey Leble
    2014 JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN

    We present the application of projection operator methods to solving the problem of the propagation and interaction of short optical pulses of different polarizations and directions in a nonlinear dispersive medium. We restrict ourselves by the caseof one-dimensional theory, taking into account material dispersion and Kerr nonlinearity. The construction of operators is delivered in two variants: for the Cauchy problem and for the given boundary regime at the initial point of the propagation half-space x > 0. As a result, we derive a system of four first-order differential equations that describe the interaction of four specified modes. In the construction of projection operators, we use an expansion with respect to a small parameter that characterizes the material dispersion, amplitude, and pulse profile. The results are compared with the vector short pulse equations (VSPE) as well as ours previous, the one for opposite propagated pulses.

  • Ultrasonic diagnostics of concrete T-beams used in bridge structures
    • Aleksandra Kuryłowicz-Cudowska
    • Magdalena Rucka
    • Krzysztof Wilde
    2014

    This paper describes a method of ultrasonic diagnostics used for prefabricated concrete elements. The studies are focused on the applicability of nondestructive techniques based on impulse and wave packet induced elastic waves for the condition assessment of T-shaped bridge beams. Experimental tests were performed for the prestressed beam used for the superstructure of the viaduct on A1 highway near Toruń. In addition numerical studies have been conducted to obtain information of the phenomenon of stress wave propagation in the T-beam. The results of numerical examinations allowed formulating requirements on configuration of a multipoint ultrasonic diagnostic system for concrete prefabricated beams.

  • Ultrawideband transmission in physical channels: a broadband interference view
    • Henryk Lasota
    • Iwona Kochańska
    • Romuald Mazurek
    2014 Full text HYDROACOUSTICS

    The superposition of multipath components (MPC) of an emitted wave, formed by reflections from limiting surfaces and obstacles in the propagation area, strongly affects communication signals. In the case of modern wideband systems, the effect should be seen as a broadband counterpart of classical interference which is the cause of fading in narrowband systems. This paper shows that in wideband communications, the time- and frequency-domain approach of the linear time-invariant (LTI) systems theory does not fully reveal the significance of channelinduced distortions. A survey of MPC interference phenomena is presented, with time-evolving impulse responses and space-dependent notransfer functions. Linear prediction technique based on the autoregressive model is successfully applied as a complementary tool for speech signal distortion analysis in public address systems.

  • Uncertainty of antioxidant profiling in complex mixtures using liquid chromatography involving post-column derivatisation
    • Bronisław K. Głód
    • Marian Antoni Kamiński
    • Paweł Zarzycki
    2014 JOURNAL OF FOOD COMPOSITION AND ANALYSIS

    The main goal of this paper is to discuss the problems associated with antioxidant profiling in complex samples using a high-throughput HPLC system coupled with post-column derivatisation reactor. Based on the experimental data reported in the literature, we demonstrated that improper optimisation of temperature and/or pH assay conditions performed using an on-line derivatisation reactor may substantially change the antioxidant peaks ratio of targeted phytochemical compounds. It has been found that despite the relatively high stability of flavonoids at high temperature and under binary mobile phase HPLC conditions, the reaction of target compounds with common ABTS, FCR and DPPH radicals at elevated regions (particularly above 100 °C) dramatically changes their antioxidant activity values expressed, for example, as TEAC (Trolox equivalent antioxidant capacity) parameters. In principle, separation and detection processes of antioxidant profiling assay must not significantly affect the antioxidant activity of target compounds. In the case of foods eaten by humans or animals, critical experimental parameters such as pH and temperature concerning interaction of target analytes with derivatisation reagent should be as close as possible to the real physiological values.

  • Uncertainty Quantification in Experimental Structural Dynamics Identification of Composite Material Structures
    • Marcin Łuczak
    • Bart Peeters
    • Maciej Kahsin
    • Simone Manzato
    • Kim Branner
    2014

    Composite materials are widely used in manufacture of aerospace and wind energy structural components. These load carrying structures are subjected to dynamic time-varying loading conditions. Robust structural dynamics identification procedure impose tight constraints on the quality of modal models estimates obtained from vibration experiments. Modal testing results are influenced by numerous factors introducing uncertainty to the measurement results. Different experimental techniques applied to the same test item or testing numerous nominally identical specimens yields different test results. This paper aims at a systematic approach for uncertainty quantification of the parameters of the modal models estimated from experimentally obtained data. Statistical analysis of modal parameters is implemented to derive an assessment of the entire modal model uncertainty measure. Investigated structures represent different complexity levels ranging from coupon, through sub-component up to fully assembled aerospace and wind energy structural components made of composite materials. The proposed method is demonstrated on two application cases of a small and large wind turbine blade.

  • Underwater Acoustic Imaging of the Sea
    • Grażyna Grelowska
    • Eugeniusz Kozaczka
    2014 Full text Archives of Acoustics

    Acoustic waves are a carrier of information mainly in environments where the use of other types of waves, for example electromagnetic waves, is limited. The term acoustical imaging is widely used in the ultrasonic engineering to imaging areas in which the acoustic waves propagate. In particular, ultrasound is widely used in the visualization of human organs - ultrasonography (Nowicki, 2010). Expanding the concept, acoustical imaging can also be used to presentation (monitoring) the current state of sound intensity distribution leading to characterization of sources in observed underwater region. This can be represented in the form of an acoustic characteristic of the area, for example as a spectrogram. Knowledge of the underwater world which is built by analogy to the perception of the space on the Earth’s surface is to be systematize in the form of images. Those images arise as a result of graphical representation of processed acoustic signals. In this paper, it is explained why acoustic waves are used in underwater imaging. Furthermore, the passive and active systems for underwater observation are presented. The paper is illustrated by acoustic images, most of them originated from our own investigation.

  • Uniwersalna bezprzewodowa stacja monitorująca
    • Piotr Rajchowski
    2014

    W artykule opisany został projekt oraz wykonanie uniwersalnej bezprzewodowej stacji monitorującej umożliwiającej rejestrowanie wielkości nieelektrycznych środowiska naturalnego, bądź spełniającej funkcję prostego systemu alarmowego. Scharakteryzowano budowę każdego z modułów składowych stacji monitorującej. Dodatkowo zawarty został opis działania stacji jak i możliwe punkty zastosowania.

  • UNIWERSALNY SPRAWDZIAN JAKOŚCI OBRÓBKI WYKOŃCZENIOWEJ CZĘŚCI MASZYN
    • Romuald Kolman
    • Włodzimierz Przybylski
    2014

    W rozdziale omówiono podstawy jakości i przemian jakościowych. Zaprezentowano istotę kryterialnych sprawdzianów jakości. Zaprojektowano uniwersalny sprawdzian jakości obróbki wykończeniowej przez nagniatanie i szlifowanie o szczegółowości do 30 kryteriów i przykłady jego wykorzystania.

  • Unusual structural properties of water within the hydration shell of hyperactive antifreeze protein
    • Anna Kuffel
    • Dariusz Czapiewski
    • Jan Zielkiewicz
    2014 Full text JOURNAL OF CHEMICAL PHYSICS

    Many hypotheses can be encountered explaining the mechanism of action of antifreeze proteins. One widespread theory postulates that the similarity of structural properties of solvation water of antifreeze proteins to ice is crucial to the antifreeze activity of these agents. In order to investigate this problem, the structural properties of solvation water of the hyperactive antifreeze protein from Choristoneura fumiferana were analyzed and compared with the properties of solvation water present at the surface of ice. The most striking observations concerned the temperature dependence of changes in water structure. In the case of solvation water of the ice-binding plane, the difference between the overall structural ordering of solvation water and bulk water diminished with increasing temperature; in the case of solvation water of the rest of the protein, the trend was opposite. In this respect, the solvation water of the ice-binding plane roughly resembled the hydration layer of ice. Simultaneously, the whole solvation shell of the protein displayed some features that are typical for solvation shells of many other proteins and are not encountered in the solvation water of ice. In the first place, this is an increase in density of water around the protein. The opposite is true for the solvation water of ice – it is less dense than bulk water. Therefore, even though the structure of solvation water of ice-binding plane and the structure of solvation water of ice seem to share some similarities, densitywise they differ.

  • Updating Finite Element Model of a Wind Turbine Blade Section Using Experimental Modal Analysis Results
    • Marcin Łuczak
    • Simone Manzato
    • Bart Peeters
    • Kim Branner
    • Peter Berring
    • Maciej Kahsin
    2014 Full text SHOCK AND VIBRATION

    This paper presents selected results and aspects of themultidisciplinary and interdisciplinary research oriented for the experimental and numerical study of the structural dynamics of a bend-twist coupled full scale section of awind turbine blade structure.Themain goal of the conducted research is to validate finite elementmodel of themodified wind turbine blade section mounted in the flexible support structure accordingly to the experimental results. Bend-twist coupling was implemented by adding angled unidirectional layers on the suction and pressure side of the blade. Dynamic test and simulations were performed on a section of a full scale wind turbine blade provided byVestasWind Systems A/S.Thenumerical results are compared to the experimental measurements and the discrepancies are assessed by natural frequency difference andmodal assurance criterion. Based on sensitivity analysis, set ofmodel parameters was selected for the model updating process. Design of experiment and response surface method was implemented to find values of model parameters yielding results closest to the experimental.The updated finite element model is producing results more consistent with the measurement outcomes.

  • Urban city lights. Light pollution as one of the effects of incorrectly designed external illumination. How can a successful lighting masterplan diminish its impact?
    • Karolina M. Zielińska-Dąbkowska
    2014

    In the modern world, artificial lighting brings many tangible benefits such as the ability to extend working hours and so increase production, recreational use of the city after dark, or the possibility to travel regardless of the time of day. However, this flexibility comes at a price and negatively impacts on the environment. One such negative phenomenon is Light Pollution ‐ a term used to describe excessive nighttime artificial lighting, present especially in large urban agglomerations. This effect is most pronounced in developed and densely populated cities in North America, East Asia and Europe [1]. Contamination of this type makes it difficult for astronomers to observe the night sky and has a negative impact on the fauna and flora, which has naturally adapted to life during night time; it can also have adverse effects on human health. The resulting phenomenon is mainly due to the operation of wrongly designed street lighting, advertising, illumination of sports stadiums, construction, security and façade lighting. To this day there is no real effective policy which deals with the problem of light pollution. There are no specific government programs which would prevent its growth, nor are there effective action plans dealing with its limitation. Therefore, this paper aims to introduce guidelines for a high quality, successful lighting masterplan ‐ from the overall context at the macro level to specific chosen issues at the micro level.

  • Urban Waterfront Regeneration: Origins of the Issue
    • Piotr Lorens
    2014

    This paper deals with the origins of the issue of urban waterfront regeneration. The process of city-water interface was described with references to the three generations of port structures.

  • Uruchomienie Laboratorium Zanurzonej Wizualizacji Przestrzennej
    • Jacek Lebiedź
    • Adam Mazikowski
    2014 Szybkobieżne Pojazdy Gąsienicowe

    Artykuł przedstawia koncepcję Laboratorium Zanurzonej Wizualizacji Przestrzennej (ang. Immersive 3D Visualization Laboratory), powstającego właśnie przy Wydziale Elektroniki, Telekomunikacji i Informatyki (ang. Faculty of Electronics, Telecommunications and Informatics) Politechniki Gdańskiej (ang. Gdańsk University of Technology) w ramach grantu Nowoczesne Audytoria Politechniki Gdańskiej (ang. project Gdansk University of Technology’s Modern Auditoriums). Podstawowym urządzeniem tego laboratorium będzie sześcienna instalacja typu CAVE (ang. Cave Automatic Virtual Environment) wzbogacona w sferyczny symulator chodu (ang. spherical walk simulator). Urządzenie to umożliwi użytkownikowi nieograniczony marsz, a nawet bieg, przez dowolnie wykreowany świat wirtualny. Jeśli świat wirtualny przyjmie postać pola bitwy lub płonącego budynku, to urządzenie będzie mogło pełnić funkcję trenażera żołnierza piechoty lub strażaka. Otwarcie laboratorium nastąpi w połowie 2014 r.

  • Urządzenia i działania dla poprawy bezpieczeństwa pieszych poruszających się wzdłuż drogi
    • Kazimierz Jamroz
    • Judyta Rychlewska
    2014

    W niniejszym rozdziale przedstawiono charakterystykę grupy urządzeń dla pieszych poruszających się wzdłuż drogi wraz z wymaganiami i standardami bezpieczeństwa ruchu drogowego, jakie te urządzenia powinny spełniać.

  • Usage of concentrated spectrogram for analysis of acoustical signals
    • Krzysztof Czarnecki
    • Marek Moszyński
    2014

    A novel precise method of signal analysis in the time-frequency domain is presented. A signal energy distribution is estimated by discard and displacement of energy parts of the classical spectrogram. A channelized instantaneous frequency and a local group delay are used in order to energy replacement. Additionally, newly introduced representations such as: a channelized instantaneous bandwidth and a local group duration are used for remove some part of irrelevant energy. An obtained energy distribution called attractogram is highly concentrated. And it causes that mono-components of an analyzed signal are precisely localized in the time-frequency domain. The presented method is utilised in order to acustical signals analysis

  • Use of electronic nose for quality assessment of agricultural ethanol distillates Wykorzystanie elektronicznego nosa do oceny jakości etanolowych destylatów rolniczych
    • Tomasz Dymerski
    • Jacek Gębicki
    • Jacek Namieśnik
    2014 Przemysł Chemiczny

    Przedstawiono wyniki badań oceny jakości destylatów rolniczych za pomocą prototypu elektronicznego nosa, wyposażonego w zestaw 6 półprzewodnikowych czujników. Frakcję lotną próbek destylatu rolniczego wytwarzano za pomocą procesu barbotażu. Klasyfikację próbek do odpowiedniej klasy jakości, przeprowadzano przy użyciu funkcji dyskryminacyjnych: liniowej i kwadratowej wspartej metodą kroswalidacji. Na podstawie przeprowadzonych analiz zaobserwowano ponad 96% poprawność klasyfikacji próbek destylatu rolniczego do poszczególnych klas jakości.

  • Use of Modified Cuckoo Search algorithm in the design process of integrated power systems for modern and energy self-sufficient farms
    • Janusz Piechocki
    • Dominik Ambroziak
    • Aleksander Pałkowski
    • Grzegorz Redlarski
    2014 APPLIED ENERGY

    In the face of increasingly stringent pollutant emission regulations, designing an agricultural holding becomes a difficult challenge of connecting a large number of coefficients that describe an energy system of a farm in regard to its ecological and economic efficiency. One way to cope with this issue is to design an energy self-sufficient farm that integrates various technologies, including renewable energy. However, the selection of appropriate components of such a system may be difficult. Large selection of facilities for management of heating and water systems and the choice of appropriate building technology makes it difficult to solve the problem of optimizing characteristics of such a holding by using standard methods. In this paper the issue of computer-aided design of energy systems for farms is dealt with. The solution proposed use the Modified Cuckoo Search algorithm in the process of optimizing the selection of particular components that influence performance of the power system, such as energy sources, water preparation systems or structure of walls. Presented results of the optimization process with the use of different fitness functions allow to state that the system developed achieved very satisfactory results and is capable to cope with the task. Through the use of the swarm algorithm it is possible to search for solutions in a large feature space and achieve optimality in terms of energy, economy and pollutant emission simultaneously.

  • Use of Neural Networks in Diagnostics of Rolling-Element Bearing of the Induction Motor
    • Leon Swędrowski
    • Kazimierz Duzinkiewicz
    • Michał Grochowski
    • Tomasz Adam Rutkowski
    2014 Key Engineering Materials

    Bearing defect is statistically the most frequent cause of an induction motor fault. The research described in the paper utilized the phenomenon of the current change in the induction motor with bearing defect. Methods based on the analysis of the supplying current are particularly useful when it is impossible to install diagnostic devices directly on the motor. The presented method of rolling-element bearing diagnostics used indirect transformation, namely Clark transformation. It determines the vector of the spatial stator current based on instantaneous current measurements of the induction motor supply phases current. The analysis of the processed measurement data used multilayered, one-directional neural networks, which are particularly attractive due to their nonlinear structure and ability to learn. During the research 40 bearings: undamaged, with damages of three types and various degrees of fault extent, were used. The conducted research proves the efficiency of neural networks for detection and recognition of faults in induction motor bearings. In case of tests of the unknown state bearings, an efficiency approach to failure detection equaled 77%.

  • Use of response surface methodology in characterization of properties of recycled high density polyethylene/ground tire rubber compositions
    • Krzysztof Formela
    • Marcin Bogucki
    2014 Full text Polimery

    Searching for newways to utilize rubber and polymerwaste has been the focus of many studies conducted by research centers and companies worldwide. In this study, the influence of extrusion conditions on the properties of thermoplastic compositions containing post-production recycled high density polyethylene (PE-HD) and ground tire rubber (GTR) at 50:50 mass ratiowas examined. Response Surface Methodology (RSM) was used to determine the effects of the barrel temperature (160—240 °C), screw speed (250—650 rpm) and feed rate of extrusion (1—2.5 kg/h) on the quality of the obtained products. Empirical models for determining the relationship between extrusion conditions, mechanical properties and the mass flow rate of obtained thermoplastic compositions were developed. It has been determined that tensile strength, elongation at break, hardness and the mass flow rate of thermoplastic compositions depend mainly on the barrel temperature. Properties of PE-HD/GTR blends deteriorated with increased barrel temperature, which was due to degradation of polyethylene and reclaiming of ground tire rubber. In studied extrusion conditions the influence of screw speed and feed rate on the properties of recycled high density polyethylene/ground tire rubber compositions was negligible.