2018 - Publications Repository - Gdańsk University of Technology

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Publications from the year 2018

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Ekspertyza z pomiarów drgań linii wałów na jednostce ORP "ORKAN"
- Zbigniew Korczewski
- Jacek Rudnicki
2018
Ekspertyza diagnostyczna dotycząca stanu technicznego trzech linii transmisji mocy (linii wałów) opracowana na podstawie przeprowadzonych pomiarów drgań w 14 punktach pomiarowych, przy jednoczesnej pracy silników napędowych L, ŚR i PB (wspólnej pracy wszystkich linii wałów), w III zakresach ustalonego obciążenia. Pomiary prędkości i przyspieszeń drgań generowanych przez węzły konstrukcyjne okrętowego układu napędowego wykonano po naprawie głównej układu napędowego w celu określenia jego stanu dynamicznego. Analizę wyników pomiarów przeprowadzono zgodnie z zaleceniami normy ISO 10816
Ekspertyza z pomiarów drgań linii wałów na jednostce TRB631
- Zbigniew Korczewski
- Jacek Rudnicki
2018
Ekspertyza diagnostyczna dotycząca stanu technicznego dwóch linii transmisji mocy (linii wałów) opracowana na podstawie przeprowadzonych pomiarów drgań w 26 punktach pomiarowych, przy jednoczesnej pracy silników napędowych L i PB (wspólnej pracy linii wałów obu burt), w II zakresach ustalonego obciążenia „pół-naprzód” i „cała-naprzód”. Pomiary prędkości i przyspieszeń drgań generowanych przez węzły konstrukcyjne okrętowego układu napędowego wykonano po naprawie głównej układu napędowego w celu określenia jego stanu dynamicznego. Analizę wyników pomiarów przeprowadzono zgodnie z zaleceniami normy ISO 10816
Eksploatacja oraz zakres remontu przyczynami destrukcji
- Maciej Niedostatkiewicz
2018 Izolacje
Błędy projektowe oraz wykonawcze mają bezpośredni wpływ na bezpieczeństwo konstrukcji i bezpieczeństwo użytkowania budynków. Na pogorszenie stanu technicznego może miec też wpływ niewłaściwy sposób użytkowania budynków.Decydujacy wpływ na tutaj regularnośc prowadzenia prac remontowych, z drugiej strony prowadzenie prac remontowych z pominięciem zasad wiedzy technicznej, często bez opracowania dokumentacji remontowej oraz przy zastosowaniu niewłaściwych rozwiązań meteriałowo-technologicznych również przycyznia sie do obniżenia sprawnosic technicznej budynków. Powyższe zagadnienia zostały opisane w omawianym artykule. .
Eksternalizacja w binauralnej ambisonicznej auralizacji źródeł kierunkowych
- Bartłomiej Mróz
- Bożena Kostek
2018 Full text Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
W artykule przedstawiono najważniejsze składniki procesu skutecznego renderowania trójwymiarowego obrazu dźwiękowego za pomocą słuchawek. W tym celu badany jest stopień oddziaływania poszczególnych czynników wpływających na eksternalizację dźwięku: śledzenie położenia głowy (ang. head tracking), indywidualne funkcje przenoszenia głowy (HRTF – Head Related Transfer Function, odnoszące się do matematycznej funkcji propagacji dźwięku wokół głowy), model pomieszczenia, jak również tzw. efekt zgodności pomieszczenia oraz indywidualne wyrównywanie charakterystyki przenoszenia słuchawek. Uzyskane wyniki wskazują, że śledzenie głowy, a także indywidualne funkcje przenoszenia głowy mają kluczowe znaczenie dla wiernej reprodukcji dźwięku. Z przeprowadzonych badań wynika również, że efekt zgodności pomieszczenia i wyrównywanie charakterystyki przenoszenia słuchawek są znaczącymi elementami procesu auralizacji.
Elastic waves in the railroad track substructures and its surroundings analyzed with non-classical operational methods
- Eligiusz Mieloszyk
- Anita Milewska
- Sławomir Grulkowski
2018
We analyze the propagation of the waves generated by the rolling stock and the interaction of those waves on the medium and its surroundings. We use non-classical operational methods for monitoring construction of the railway infrastructure and for noise damping.
Elastoplastic nonlinear FEM analysis of FGM shells of Cosserat type
- Stanisław Burzyński
- Jacek Chróścielewski
- Karol Daszkiewicz
- Wojciech Witkowski
2018 Full text COMPOSITES PART B-ENGINEERING
The paper is a continuation of [1] where the formulation of the elastic constitutive law for functionally graded materials (FGM) on the grounds of nonlinear 6-parameter shell theory with the 6th parameter (the drilling degree of freedom) was presented. Here the formulation is extended to the elasto-plastic range. The material law is based on Cosserat plasticity and employs the well-known Tamura-Tomota-Ozawa (TTO) [2] mixture model with additional formulae for Cosserat material parameters. Formulation is verified by solving a set of demanding analyses of plates, curved and multi-branched shells, including geometry, thickness and material distribution variation parameter analyses.
Electric shock hazard in circuits with variable-speed drives
- Stanisław Czapp
- Jarosław Guziński
2018 Full text Bulletin of the Polish Academy of Sciences-Technical Sciences
The conventional approach to electrical safety under fault condition in typical power systems considers earth fault currents of sinusoidal waveform and frequency of 50/60 Hz. However, in circuits with variable-speed drives, there is earth fault current flow with harmonics, and these harmonics influence the threshold of ventricular fibrillation. The paper presents earth fault current waveforms in circuits with variable-speed drives without inverter output (motor) filter and with one of the two types of inverter output filters being used. The details of both filters are presented, and the effect of harmonics of earth fault current on ventricular fibrillation is evaluated. Furthermore, the effect of harmonics, which occurs in circuit of variable-speed drive, on the tripping current of residual current devices is presented. Residual current devices may be utilized to ensure protection against direct and indirect contact, but limitations in their proper operation, due to harmonics, may exist. Operational characteristics of a proposed residual current device dedicated to circuits with earth fault current containing harmonics, as in the variable-speed circuits, are presented.
Electric transport in organic system with planar DBP/F16ZnPc junction on the basis of direct current and small signal admittance spectra analysis
- Rafał Marczyński
- Justyna Szostak
- Ryszard Signerski
- Grażyna Jarosz
2018 Full text SYNTHETIC METALS
The objective of this work was to determine electric transport in the organic device based on a planar junction of electron donor and electron acceptor materials, namely ITO/MoO3/DBP/F16ZnPc/BCP/Ag. The analysis reported herein was based on direct current-voltage measurements and small-signal admittance spectra in the dark and under illumination. Such analysis may provide information on potential barriers, parasitic resistances and presence of space charge affecting the electric current flow within the device. Therefore, this approach could be applied for determination of physical processes related to electric charge transport within multilayer structures, such as photovoltaic cells or photodetectors. In the case of the investigated system, the parallel parasitic resistance, the resistance of electrodes, and the geometric capacitance of 10 MΩ, 55 Ω, and 1.6 nF respectively were found. It was also shown that the direct current flowing from ITO to Ag was limited by charge carrier injection from electrodes, while in the case of current flowing from Ag to ITO no essential barriers at electrodes were noticed.
Electrical properties of Na2O-CaO-P2O5 glasses doped with SiO2 and Si3N4
- Natalia Anna Wójcik
- B Jonson
- Ryszard Jan Barczyński
- Piotr Kupracz
- D Möncke
- S Ali
2018 Full text SOLID STATE IONICS
Sodium-calcium-phosphate glasses doped with SiO2 or Si3N4 having similar sodium ion concentrations were prepared by melt quenching. The conductivity was measured by impedance spectroscopy under nitrogen atmosphere in a wide frequency range (10 mHz–1 MHz) and wide temperature range (153–473 K). At 36.6 °C, DC conductivities of all glasses vary between 1.1 ∗ 10−12 and 8.9 ∗ 10−12 S cm−1 and have similar activation energies (between 0.87 and 0.91 eV), which are characteristic for an ionic conduction mechanism. The analysis of AC conductivities showed that the spectra are governed by one dynamic process – hopping of the mobile charge carriers - which may be described i.e., by the ‘concept of mismatch and relaxation’ or by the ‘random barrier’ model. The obtained results confirmed a higher influence of nitrogen incorporation on the various glass conductivity parameters than shown for silicon doping alone. However, the influence of fundamental structural changes on the glass conductivity is less relevant as is the overall sodium ion concentration, which remains the decisive factor for a high ion conduction.
Electrical Propterties of Solution Mixtures for Bath Supervision in Ambient Assisted Living
- Adam Bujnowski
- Kamil Osiński
- Artur Poliński
- Tomasz Kocejko
- Jerzy Wtorek
- Alexey Andrushevich
2018
Impedance properties of bath solution are compared. Any ingredient such as soap, shampoo or bathing salt changes bath-solution’s electrical properties eg. impedance. We have measured and analysed influence of typical bathing ingredients on electrical properties of the solution. We investigate impedance changes over frequency range from 100Hz tu 100kHz as it is most applicable for person detection. Electrical properties of bath solution knowledge is essential for person detection and biosignal acquisition of bathing person.
Electrical Stimulation Modulates High Gamma Activity and Human Memory Performance
- Michał Tomasz Kucewicz
2018 Full text eNeuro
Direct electrical stimulation of the brain has emerged as a powerful treatment for multiple neurological diseases, and as a potential technique to enhance human cognition. Despite its application in a range of brain disorders, it remains unclear how stimulation of discrete brain areas affects memory performance and the underlying electrophysiological activities. Here, we investigated the effect of direct electrical stimulation in four brain regions known to support declarative memory: hippocampus (HP), parahippocampal region (PH) neocortex, prefrontal cortex (PF), and lateral temporal cortex (TC). Intracranial EEG recordings with stimulation were collected from 22 patients during performance of verbal memory tasks. We found that high γ (62–118 Hz) activity induced by word presentation was modulated by electrical stimulation. This modulatory effect was greatest for trials with “poor” memory encoding. The high γ modulation correlated with the behavioral effect of stimulation in a given brain region: it was negative, i.e., the induced high γ activity was decreased, in the regions where stimulation decreased memory performance, and positive in the lateral TC where memory enhancement was observed. Our results suggest that the effect of electrical stimulation on high γ activity induced by word presentation may be a useful biomarker for mapping memory networks and guiding therapeutic brain stimulation.
Electrochemical and photoelectrochemical properties of the interface between titania nanotubes covered by conducting polymer in aqueous by conducting polymer in aqueous electrolytes – The effect of various geometry and electrolytes concentration
- Mariusz Szkoda
- Konrad Trzciński
- Anna Lisowska-Oleksiak
- Katarzyna Siuzdak
2018 APPLIED SURFACE SCIENCE
In the present work we show the impact of nanotubes (NTs) geometry of titania utilized as a substrate in organic-inorganic systems acting as a p-n junction on efficient conversion of radiation energy into electrochemical energy. The electrolytic bath composition and electrolysis conditions were controlled in order to obtain TiO2NTs of various geometry as a result of electrochemical oxidation of titanium foil. The electrode material was characterized using scanning electron microscopy, Raman and UV–vis spectroscopies in order to investigate their morphology, crystallinity and absorbance ability, respectively. According to SEM inspection, the electrolyte bath composition (water content) and duration of electrolysis significantly affects TiO2NTs morphology, namely the internal diameter and the layer thickness. The TiO2NTs electrode/electrolyte interface characterized using electrochemical impedance spectroscopy (EIS) exhibits varied impedance parameters depending on the outer K2SO4 electrolyte concentration (in the range of: 0.01–0.2 M) as the electric charge distribution at the interface is concentration dependent. The series of hydrogenated titania substrates were electrochemically modified by the conducting polymer: poly(3,4-ethylenedioxytiophene) doped with polystyrene sulphonate (pEDOT:PSS) thin film. The optimal geometry of titania was determined based on the photocurrent density recorded for the composite material (TiO2NTs/pEDOT:PSS). The most photoactive organic inorganic junction is composed of titania tubes of 2.5 µm length, the outer diameter equal to 205 nm giving the real surface area equal to 49.9 cm2 per 1 cm2.
Electrochemically Obtained TiO2/CuxOy Nanotube Arrays Presenting a Photocatalytic Response in Processes of Pollutants Degradation and Bacteria Inactivation in Aqueous Phase
- Magda Kozak
- Paweł Mazierski
- Joanna Żebrowska
- Marek Kobylański
- Tomasz Klimczuk
- Wojciech Lisowski
- Grzegorz Trykowski
- Grzegorz Nowaczyk
- Adriana Zaleska-Medynska
2018 Full text Catalysts
TiO2/CuxOy nanotube (NT) arrays were synthesized using the anodization method in the presence of ethylene glycol and different parameters applied. The presence, morphology, and chemical character of the obtained structures was characterized using a variety of methods—SEM (scanning electron microscopy), XPS (X-ray photoelectron spectroscopy), XRD (X-ray crystallography), PL (photoluminescence), and EDX (energy-dispersive X-ray spectroscopy). A p-n mixed oxide heterojunction of Ti-Cu was created with a proved response to the visible light range and the stable form that were in contact with Ti. TiO2/CuxOy NTs presented the appearance of both Cu2O (mainly) and CuO components influencing the dimensions of the NTs (1.1–1.3 µm). Additionally, changes in voltage have been proven to affect the NTs’ length, which reached a value of 3.5 µm for Ti90Cu10_50V. Degradation of phenol in the aqueous phase was observed in 16% of Ti85Cu15_30V after 1 h of visible light irradiation (λ > 420 nm). Scavenger tests for phenol degradation process in presence of NT samples exposed the responsibility of superoxide radicals for degradation of organic compounds in Vis light region. Inactivation of bacteria strains Escherichia coli (E. coli), Bacillus subtilis (B. subtilis), and Clostridium sp. in presence of obtained TiO2/CuxOy NT photocatalysts, and Vis light has been studied showing a great improvement in inactivation efficiency with a response rate of 97% inactivation for E. coli and 98% for Clostridium sp. in 60 min. Evidently, TEM (transmission electron microscopy) images confirmed the bacteria cells’ damage.
Electrode materials for electrochemical capacitors based on poly(3,4-ethylenedioxythiophene) and functionalized multi-walled carbon nanotubes characterized in aqueous and aprotic electrolytes
- Anna Danuta Dettlaff
- Pratik R. Das
- Lidiya Komsiyska
- Oliver Osters
- Justyna Łuczak
- Monika Wilamowska-Zawłocka
2018 SYNTHETIC METALS
Within this work, we report a facile one-stage synthesis of nanocomposites based on functionalized carbon nanotubes (CNTs) and electroactive polymer poly(3,4-ethylenedioxythiophene). Three different composites are investigated as potential electrode materials for the electrochemical capacitors. Two of the composites contain carbon nanotubes (ox-CNTs), functionalized by acid oxidation process (65% HNO3, 120 °C). The third composite comprises of non-covalently functionalized carbon nanotubes, modified by surfactant addition. The functionalization process provides a uniform distribution of carbon nanotubes in water, what in turn helps to synthesize homogenous and reproducible composite materials. The composites are synthesized by chemical polymerization of EDOT in the solution of dispersed carbon nanotubes. The goal of such synthesis is to obtain polymer chains directly on CNTs. For comparison, one composite is prepared by simple dispersion of ox-CNTs in the commercially available pEDOT/polystyrene sulfonate (PSS) solution. The composite layers are tested electrochemically in aqueous and aprotic electrolytes for electrochemical capacitor application. The electrochemical results reveal that the presence of oxidized carbon nanotubes improves the conductivity and increases the capacitance values of the composites layers. The best electrochemical performance (capacitance of approx. 80 F g−1 in the aqueous and aprotic electrolyte) is exhibited by the composite obtained by chemical polymerization of EDOT in the solution of ox-CNTs.
Electromagnetic forced vibrations of composite nanoplates using nonlocal strain gradient theory
- Mohammad Malikan
- Van Bac Nguyen
- Francesco Tornabene
2018 Full text Materials Research Express
This article is intended to analyze forced vibrations of a piezoelectric-piezomagnetic ceramic nanoplate by a new refined shear deformation plate theory in conjunction with higher-order nonlocal strain gradient theory. As both stress nonlocality and strain gradient size-dependent effects are taken into account using the higher-order nonlocal strain gradient theory, the governing equations of the composite nanoplate are formulated. When the nanoplate is subjected to a transverse harmonic loading and all the edges are considered as simple boundaries, the governing equations can be solved with a closed-form solution, from which the maximum dynamic deflections are obtained. To validate the results of the new proposed plate theory, the comparisons between ours and the well-known papers in the literature are presented. The influences of different nonlocal parameters and material properties on the nanoplate's dynamic responses are also studied.
Electron attachment to hexafluoropropylene oxide (HFPO)
- Mateusz Zawadzki
- Alise Chachereau
- Jaroslav Kočišek
- Christian Franck
- Juraj Fedor
2018 Full text JOURNAL OF CHEMICAL PHYSICS
We probe the electron attachment in hexafluoropropylene oxide (HFPO), C3F6O, a gas widely used in plasma technologies. We determine the absolute electron attachment cross section using two completely different experimental approaches: (i) a crossed-beam experiment at single collision conditions (local pressures of 5 × 10−4 mbar) and (ii) a pulsed Townsend experiment at pressures of 20–100 mbar. In the latter method, the cross sections are unfolded from the electron attach- ment rate coefficients. The cross sections derived independently by the two methods are in very good agreement. We additionally discuss the dissociative electron attachment fragmentation patterns and their role in the radical production in industrial HFPO plasmas.
Electron collisions with cyanoacetylene HC3N : Vibrational excitation and dissociative electron attachment
- Milos Ranković
- P Nag
- Mateusz Zawadzki
- L Ballauf
- J Žabka
- M Polášek
- Jaroslav Kočišek
- Juraj Fedor
2018 Full text PHYSICAL REVIEW A
We experimentally probe electron collisions with HC3N in the energy range from 0 to 10 eV with the focus on vibrational excitation and dissociative electron attachment. The vibrational excitation cross sections show a number of resonances which are mode specific: the two dominant π∗ resonances are visible in the excitation of all the vibrational modes; however, broad σ ∗ resonances are visible only in certain bond-stretching vibrational modes. The lower π∗ resonance shows a pronounced boomerang structure. Since it overlaps with the threshold peak originating from a long-range electron-molecule interaction, the interference pattern is rather unusual. Somewhat surprisingly, the boomerang structure is visible also in the elastic scattering cross section. The dissociative electron attachment cross sections agree qualitatively with the data of Gilmore and Field [J. Phys. B 48, 035201 (2015)]; however, approximately a factor of two difference is found in the absolute values.
Electron impact ionization and cationic fragmentation of the pyridazine molecules
- Marcin Dampc
- Paweł Możejko
- Mariusz Zubek
2018 Full text EUROPEAN PHYSICAL JOURNAL D
Electron impact mass spectroscopy was used to investigate ionization and cationic fragmentation of the pyridazine (1,2 diazine), C4H4N2, molecules in the gas phase. The mass spectra were measured and the observed mass peaks assigned to the corresponding cations. The appearance energies of most of the cationic fragments were determined and the possible fragmentation processes are discussed. The total cross section for electron impact ionization of pyridazine was calculated using the binary-encounter-Bethe (BEB) model. The calculated cross section was applied to normalize the measured cation yield curves and total and partial cross sections for ionization and cationic fragmentation were obtained over the energy range from the respective ionization thresholds to 140 eV.
Electron interactions with Bis(pentamethylcyclopentadienyl) titanium(IV) dichloride and difluoride
- Jakob Langer
- Mateusz Zawadzki
- Michal Fárník
- Jiří Pinkas
- Juraj Fedor
- Kočišek Jaroslav
2018 EUROPEAN PHYSICAL JOURNAL D
We present a combined experimental and theoretical study of the interaction of electrons with Bis(pentamethylcyclopentadienyl)titanium(IV) dichloride (Cp∗2TiCl2) and difluoride (Cp∗2TiF2). We report the experimental measurements of partial cross sections for the dissociative electron attachment (DEA) and the electron ionization (EI) mass spectra of isolated molecules. Estimates of the absolute cross sections are done on the basis of cross-calibration in the case of DEA and on the basis of binary-encounter-Bethe calculation in the case of EI. EI of both molecules is similar, concerning cross section amplitude and fragmentation pattern. DEA is different: DEA to Cp∗2 TiF2 primarily results in the formation of stable parent anion, while DEA to Cp∗2TiCl2 results in the strong fragmentation, primarily into Cl− anion. Possible use of the molecules as the model species for studies of DEA efficiency in postirradiation chemistry is discussed.
Electron Scattering on X(CH3)4 Molecules: Applicability of Simple Additivity Rule and Role of Methylation
- Sylwia Stefanowska-Tur
- Paweł Możejko
- Elżbieta Ptasińska-Denga
- Czesław Szmytkowski
2018
To investigate influence of target methylation (substitution of a hydrogen atom by methyl group) on electron-collision processes we compare absolute total cross sections for XH4 and X(CH3)4 molecules, where X is Si and Ge, respectively. We also compare experimental TCSs energy dependencies with estimated data obtained using simple formula and TCSs for methyl group and those for SiH4 and GeH4. Electron-scattering TCSs for mentioned compounds are measured using linear transmission method.