2014 - Repozytorium publikacji - Politechnika Gdańska

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Nanostructure and dielectric behavior of vanadate glasses containing BaTiO3
- Natalia Anna Wójcik
- Piotr Kosiorek
- Kamil Kasiak
- Jakub Karczewski
- Maria Gazda
- Ryszard Jan Barczyński
2014 JOURNAL OF NON-CRYSTALLINE SOLIDS
The ac and dc electrical conductivity of barium titanate doped bismuth-vanadate as-quenched and heat-treated materials was measured in the frequency range from 1 mHz to 1 MHz and in the temperature range from 153 K to 423 K with the impedance spectroscopy method. The microstructure was investigated by means of XRD, scanning electron microscopy (SEM), atomic force microscopy (AFM) and confocal microscopy. The obtained results showed that the structure of both as-quenched and heat-treated samples is not homogenous. Heat-treatment had significant influence on the amount, size and chemical composition of formed micro- and nanocrystallites. It also had great impact on the conduction process in investigated materials. As-quenched samples showed one relaxation process that was due to the overlapping polaron hopping. Conduction process in heat-treated samples may be caused by two different conduction mechanisms within nanostructures and in the matrix or by the interface polarization. Direct current conductivity increased and activation energies of this process decreased after heat-treatment. The experimental results were discussed based on a “core–shell” model and conductivity models collected by Elliot.
Nano-structured Pt embedded in the acidic salts of heteropolymolybdate matrices: MS XAFS study
- Agnieszka Witkowska
- Sonia Dsoke
- Roberto Marassi
- Andrea Di Cicco
2014 Synchrotron Radiation in Natural Science
Multiple-scattering extended X-ray absorption fine structure (MS EXAFS) study combined with TEM and XRD analysis of a novel Pt-based catalyst operating at low temperature fuel cells (FCs) is presented. Innovation in the case of the considered catalyst resides in the use of a porous inorganic matrix of acidic heteropolymolybdate salts as a catalyst support. Obtained results show the relation between the matrix composition and the size of the obtained metallic Pt nanoparticles. Thus, the desired/optimal Pt nanoparticle size can be precisely controlled by the application of the proper support composition.
Nanotechnologia w architekturze – korzyści i problemy wynikające z zastosowania nanotechnologii w aspekcie cyklu życia budynku
- Paweł Sikora
- Andrzej Stokwisz
2014
Dynamiczny rozwój technologii zawsze odgrywał ważną rolę w procesie kształtowania architektury. Postęp w dziedzinie inżynierii materiałowej już od Rewolucji Przemysłowej pozwalał na osiąganie co raz bardziej skomplikowanych i jednocześnie wytrzymałych konstrukcji budynków. Obecnie, w dziedzinie architektury, zaczyna pojawiać się pojęcie nanotechnologii, która pozwala zmieniać stosowane materiały w bardziej wydajne i odporne. Elementy wyposażenia wyprodukowane z zastosowaniem nanotechnologii są bardziej trwałe a proces ich zużycia znacząco się opóźnia. Zapewniają wieloletnią użyteczność i wytrzymałość budynków, zmniejszają ilość remontów, oszczędzają energię i czas. Budynki wykorzystujące nanotechnologię, stanowią przyszłość w dziedzinie rozwoju architektury, są wysokiej jakości zaawansowanymi technologicznie produktami, które powinny przyczynić się do poprawy jakości życia i pracy ich użytkowników. Użycie materiałów i rozwiązań opartych na nanotechnologii wiąże się jednak z szeregiem problemów, jakie mogą pojawić się w trakcie procesu inwestycyjnego, a także później w trakcie cyklu życia budynku. Wiedza o nich może w znacznym stopniu przyczynić się do lepszego zarządzania ryzykiem podczas realizacji projektu, a także zarządzania samym projektem, a następnie budynkiem. Problemy związane z wykorzystaniem nanotechnologii skupiają się głównie wokół ich wdrożenia do realizacji, w szczególności w inwestycjach finansowanych w oparciu o ustawę „Prawo Zamówień Publicznych”, z powodu praw własności i praw patentowych dla użytych rozwiązań i ograniczenia konkurencji w stosunku do innych firm. W artykule zostaną opisane kwestie dotykające potencjału, ale także problemów związanych z wdrożeniem i zastosowaniem materiałów opartych na nanotechnologii.
Nanotubular oxide layers and hydroxyapatite coatings on ‘Ti–13Zr–13Nb’ alloy
- Andrzej Zieliński
- Paulina Strąkowska
- Krzysztof Krzysztofowicz
2014 SURFACE ENGINEERING
The presented research was aimed to determine the mechanical properties of the nanotubular oxide layer covered with hydroxyapatite coating. The Ti–13Zr–13Nb alloy was oxidised in 1M phosphoric acid with an addition of 0?5% HF for HF solution at 20 V voltage. The electrochemically assisted deposition of hydroxyapatite was performed at cyclic polarisation in NH4H2PO4 and CaCl2 solution at 80uC. The mechanical properties were determined by nanoindentation, nanocreep and nanoscratch tests. The surface examinations were made with the light, scanning electron and atomic force microscopes. The measurements showed the significant difference between an oxide layer and nanotubular oxide coated with hydroxyapatite. The observed differences may be explained by an appearance of mechanically strong oxide layer, to which the ceramic hydroxyapatite layer is not tightly bound. The obtained results suggest that the nanotubular oxide layers should be covered with nanohydroxyapatite coatings, which would come inside the nanotubes resulting in better adhesion.
Narzędzia i problemy kształtowania urbanistyki małych miast
- Hanna Obracht-Prondzyńska
2014
Narzędzia i problemy kształtowania urbanistyki małych miast
NASBA – IZOTERMICZNA AMPLIFIKACJA RNA
- Milena Kordalewska
2014 Dokonania Młodych Naukowców
NASBA (ang. Nucleic Acid Sequence-Based Amplification) jest skuteczną i czułą techniką izotermicznej amplifikacji opartej na transkrypcji, służąca głównie do detekcji cząsteczek RNA. Znalazła ona zastosowanie do wykrywania RNA wirusowego, bakteryjnego i grzybiczego w próbkach klinicznych oraz żywości.
Natural radioactivity of solid and liquid phases from shale oil and gas prospection in Pomerania
- Anna Mykowska
- Jan Hupka
2014 Pełny tekst POLISH JOURNAL OF ENVIRONMENTAL STUDIES
Ionizing radiation intensity data and estimation of equivalent absorbed dose from solid and liquid samples from prospection of shale gas and oil at selected sites in Pomerania are presented. Naturally occurring radioactive materials (NORM) are associated with geological formations or fluids and can be enhanced during oil and gas production. They appear in e.g. drilling cuttings, flow back water, produced water, scale and sludge. In this study only gamma rays were detected and their intensity was comparable to the background radiation which is 20,0±4,6 [min-1]. The highest value: 27,3 [min-1] was detected in solid residue from evaporated flow back fluid after hydraulic fracturing. The equivalent absorbed dose from this sample was ~ 2 Sv/a what is lower than the global average dose from the background radiation 2,4 Sv/a. In this regard, workers and others in the vicinity of drilling well sites will not be exposed to external or internal ionizing radiation.
Nauczanie bioinżynierii z zastosowaniem narzędzi informatycznych i metod stosowanych w elektrotechnice oraz grafach wiązań
- Wacław Matulewicz
2014 Pełny tekst Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
Przedstawiono sposoby badań zjawisk zachodzących w krwiobiegu za pomocą obwodów elektrycznych oraz grafów wiązań. Symulacje zjawisk stanowią jeden z elementów nauczania bioinżynierii dla studentów uczelni technicznych.
Nauczanie chemii analitycznej w Polsce (I)
- Marek Biziuk
2014 Orbital
W publikacji, opracowanej na podstawie ankiet, przedstawiono rolę i zadania Chemii Analitycznej oraz zakres materiału, który powinien być wykładany na uniwersytetach, politechnikach i uniwersytetach medycznych. Przedstawiono również jak te założenia są realizowane na poszczególnych uniwersytetach, a także jakie kierunki dyplomowania, ściśle związane z Chemią Analityczną,są w nich prowadzone. Zestawiono także kursy, letnie szkoły i szkolenia, a także Studia Podyplomowe prowadzone w poszczególnych uczelniach.
Navier number and transition to turbulence
- Paweł Ziółkowski
- Janusz Badur
2014 Pełny tekst Journal of Physics : Conference Series
The motivation behind this article is to explain a role of the Navier number (Na -dimensionless slip-length) in prediction of closures for laminar to turbulent transition undergoing via eddies detachment from the slip layer in nano-cannals. Additionally the role of the Navier number Na in universal modeling of phenomenon of enhanced mass flow rate reported in micro- and nano-channels has been explained. The Na number should be treated as a ratio of internal viscous to external viscous momentum transport and therefore this notion cannot be extended onto whole friction resistance phenomena. Our proposal for unique expressing of a critical point in turbulence transition is that on a plane of fD - Re one needs two coordinates. The second critical coordinate has been discovered by Stanton and Pannell and is known to be the Stanton-Pannell number StPa. Finally dependence of the Stanton-Pannell number StPa on Navier number Na and Reynolds number Re is presented.
Necessary and Sufficient Condition for State-Independent Contextual Measurement Scenarios
- Ravishankar Ramanathan
- Paweł Horodecki
2014 PHYSICAL REVIEW LETTERS
The problem of identifying measurement scenarios capable of revealing state-independent contextuality in a given Hilbert space dimension is considered. We begin by showing that for any given dimension d and any measurement scenario consisting of projective measurements, (i) the measure of contextuality of a quantum state is entirely determined by its spectrum, so that pure and maximally mixed states represent the two extremes of contextual behavior, and that (ii) state-independent contextuality is equivalent to the contextuality of the maximally mixed state up to a global unitary transformation. We then derive a necessary and sufficient condition for a measurement scenario represented by an orthogonality graph to reveal state-independent contextuality. This condition is given in terms of the fractional chromatic number of the graph χ f (G) and is shown to identify all state-independent contextual measurement scenarios including those that go beyond the original Kochen-Specker paradigm.
Nested Space Mapping Technique for Design and Optimization of Complex Microwave Structures with Enhanced Functionality
- Sławomir Kozieł
- Adrian Bekasiewicz
- Piotr Kurgan
2014
In this work, we discuss a robust simulation-driven methodology for rapid and reliable design of complex microwave/RF circuits with enhanced functionality. Our approach exploits nested space mapping (NSM) technology, which is dedicated to expedite simulation-driven design optimization of computationally demanding microwave structures with complex topologies. The enhanced func-tionality of the developed circuits is achieved by means of slow-wave resonant structures (SWRSs), used as replacement components for conventional transmis-sion lines. The NSM is a hierarchical, bottom-up methodology, in which the inner space mapping layer is applied to improve generalization capabilities of the equivalent circuit constructed on the SWRS level, whereas the outer layer is used to enhances the surrogate model of the entire structure of interest. We demonstrate that the NSM significantly improves the performance of traditional surrogate-based optimization routines applied to the design problem of computationally expensive microwave/RF structures with modular topology. The proposed technique is used to design three exemplary microwave/RF circuits with enhanced functionality: two abbreviated microstrip matching transformers and a miniaturized rat-race coupler with harmonic suppression. We also provide a comprehensive comparison with other surrogate-assisted methods, as well as supply the reader with basic design guidelines for the state-of-the-art SWRS-based microwave/RF circuits.
Nested Space Mapping Technology for Expedite EM-driven Design of Compact RF/microwave Components
- Adrian Bekasiewicz
- Sławomir Kozieł
- Piotr Kurgan
- Leifur Leifsson
2014 Pełny tekst Procedia Computer Science
A robust simulation-driven methodology for rapid and reliable design of RF/microwave circuits comprising compact microstrip resonant cells (CMRCs) is presented. We introduce a nested space mapping (NSM) technology, in which the inner space mapping layer is utilized to improve the generalization capabilities of the equivalent circuit model corresponding to a constitutive element of the circuit under consideration. The outer layer enhances the surrogate model of the entire structure under design. We demonstrate that NSM significantly improves performance of surrogate-based optimization of composite RF/microwave structures. It is validated using two examples of UWB microstrip matching transformers (MTs) and compared to other competitive surrogate-assisted methods attempting to solve the problem ofcompact RF/microwave component design.
Network Approach to Increments of RR-intervals for Visualization of Dynamics of Cardiac Regulation
- Danuta Makowiec
- Zbigniew R. Struzik
- Beata Graff
- Grzegorz Graff
- Dorota Wejer
- Agnieszka Kaczkowska
- Joanna Wdowczyk-Szulc
- Marta Buchowiecka
2014
The transition network for RR -increments is pre- sented in a directed and weighted graph, with vertices represent- ing RR -increments and edges corresponding to the order in a sequence of increments. The adjacency matrix and the transition matrix of this network provide a graphical tool which could be useful in the assessment of cardiac regulation. As an example, the method is applied in detecting differences between diurnal activity and nocturnal rest.
Network-aware Data Prefetching Optimization of Computations in a Heterogeneous HPC Framework
- Paweł Rościszewski
2014 Pełny tekst International Journal of Computer Networks & Communications (IJCNC)
Rapid development of diverse computer architectures and hardware accelerators caused that designing parallel systems faces new problems resulting from their heterogeneity. Our implementation of a parallel system called KernelHive allows to efficiently run applications in a heterogeneous environment consisting of multiple collections of nodes with different types of computing devices. The execution engine of the system is open for optimizer implementations, focusing on various criteria. In this paper, we proposea new optimizer for KernelHive, that utilizes distributed databases and performs data prefetching to optimize the execution time of applications, which process large input data. Employing a versatile data management scheme, which allows combining various distributed data providers, we propose using NoSQL databases for our purposes. We support our solution with results of experiments with real executions of our OpenCL implementation of a regular expression matching application in various hardware configurations. Additionally, we propose a network-aware scheduling scheme for selecting hardware for the proposed optimizer and present simulations that demonstrate its advantages.
Neural Networks, Support Vector Machine and Genetic Algorithms for Autonomous Underwater Robot Support
- Jerzy Balicki
- Jan Masiejczyk
- Piotr Przybecki
- Marcin Zadroga
2014
In this paper, artificial neural networks, a classification technique called support vector machine and meta-heuristics genetic algorithm have been considered for development in autonomous underwater robots. Artificial neural networks have been used for seabed modelling as well as support vector machine has been applied for the obstacles classification to avoid some collision problems. Moreover, genetic algorithm has been applied to trajectory planning of underwater robots. Finally, some numerical experiments have been presented.
New approaches for improving selectivity and sensitivity of resistive gas sensors: A review
- Janusz Smulko
- Maciej Trawka
- Lech Hasse
- Claes G. Granqvist
- Radu Ionescu
- Fatima E. Annanouch
- Eduard Llobet
- Laszlo B. Kish
2014
Resistive gas sensors are very popular and reliable but suffer from low selectivity and sensitivity. Various methods have been suggested to improve both features without increasing the number of sensors in gas detection systems. Fluctuation enhanced gas sensing was proposed to improve gas detection efficiency by analyzing low-frequency resistance fluctuations, and noise parameters can be more informative than the single DC resistance and can advance gas detection systems by improving detection and limiting energy consumption. Gas sensor temperature can be modulated as well to further increase selectivity and sensitivity. Finally, some gas sensing layers exhibit a photo-catalytic effect, which can be applied to improve detection and yield lower operating temperatures of the gas sensing materials.
New ceramic materials derived from pyrolyzed poly(1,2-dimethylsilazane) and starch as a potential anode for Li-ion batteries
- Andrzej Nowak
- Beata Wicikowska
- Anna Lisowska-Oleksiak
2014 SOLID STATE IONICS
Newmaterialswere obtained by pyrolysis of starch (S) and poly(1,2-dimethylsilazane) (PSN) (weight ratio: PSN/S 30/70) at temperature a) 500 °C, b) 700 °C and c) 900 °C. Ceramic materials were characterized by infrared spectroscopy, TGA, Raman spectroscopy and SEM. New Si\O and shifted Si\C stretching vibration modes emerged confirming direct interaction between silicon originating fromsilazane and oxygen coming fromstarch. The specific capacity of PSN/S 30/70 pyrolyzed at 900 °C was 301 mAh/g with capacity fading about 6% after 100th cycles. These values are higher (~50%) in comparison with the capacity of pure starch pyrolyzed at the same conditions. Electrochemical impedance spectroscopy allowed to establish temperature dependence of the particular components of an electrical equivalent circuit. The Arrhenius type behavior was confirmed for ionic transport within SEI. The charge transfer resistance, being a part of modified Randles circuit, was found to increase with temperature. Ionic transport within the electrode bulk material is represented by semiinfinitive Warburg impedance. The reciprocal of Warburg coefficient (1/σW) diminishes with temperature.
New developments in preparation and use of standard gas mixtures
- Marta Słomińska
- Piotr Konieczka
- Jacek Namieśnik
2014 TRAC-TRENDS IN ANALYTICAL CHEMISTRY
Standard gas mixtures are commonly applied in all stages of analytical work related to the analysis of gaseous samples. Numerous techniques for generating standard gas mixtures are in use. In this article, we present new developments regarding the production of standard gas mixtures, with particular focus on improvements in the application of dynamic techniques for generating them. Furthermore, we describe the application of new techniques, such as thermal decomposition or transferring a small amount of gas.
New First - Path Detector for LTE Positioning Reference Signals
- Paweł Gadka
2014
In today's world, where positioning applications reached a huge popularity and became virtually ubiquitous, there is a strong need for determining a device location as accurately as possible. A particularly important role in positioning play cellular networks, such as Long Term Evolution (LTE). In the LTE Observed Time Difference of Arrival (OTDOA) positioning method, precision of device location estimation depends on accuracy of the Positioning Reference Signal (PRS) first-path detection, what is particularly challenging in multipath environment. There are a few algorithms, available in the literature, that are dedicated to detect the first-path of PRS signals, often basing on estimation of the strongest path or which do not adapt to continuously changing environmental conditions. The paper presents a new algorithm, called First-Path Estimator (FPE), which detects the first path of received PRS signal in the LTE system. Simulations showed that proposed algorithm reduces Received Signal Time Difference (RSTD) measurement error compared to the well-known Maximum Likelihood Estimator (MLE) in urban scenario.