2017 - Repozytorium publikacji - Politechnika Gdańska

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Publikacje z roku 2017

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Phosphanylphosphido and phosphanylphosphinidene complexes of zirconium(IV) supported by bidentate N,N ligands
- Mateusz Zauliczny
- Rafał Grubba
- Łukasz Ponikiewski
- Jerzy Pikies
2017 POLYHEDRON
Phosphanylphosphido complexes of zirconium, [NacNacZrCl2(η2-R2P–PSiMe3)] (R = t-Bu, i-Pr), were synthesized in the reaction of R2P–P(SiMe3)Li·nTHF (R = t-Bu, i-Pr) with a β-diketiminate complex, [NacNacZrCl3], in toluene. Elimination of Me3SiCl from [NacNacZrCl2(η2-R2P–PSiMe3)] provided the phosphanylphosphinidene complexes [NacNacZrCl(η2-R2P–P)] (R = t-Bu, i-Pr). Moreover, the reaction of [NacNacZrCl2(η2-R2P–PSiMe3)] with R2P–P(SiMe3)Li·nTHF yielded the phosphanylphosphinidenoid complexes [NacNacZrCl2(η2-R2P–PLi)] (R = t-Bu, i-Pr). The same reaction, but in the presence of 12-crown-4, gave rise to the phosphanylphosphinidene complexes [NacNacZrCl(η2-R2P–P)]. The X-ray structures of [NacNacZrCl2(η2-i-Pr2P–PSiMe3)] and [NacNacZrCl(η2-t-Bu2P–P)] revealed that the R2P-P ligands exhibit side-on coordination to the metal center. From the reaction of i-Pr2P–P(SiMe3)Li·3THF with [{PhN(CH2)3NPh)}ZrCl2], a triple-core, anionic, phosphanylphosphinidene complex, [{PhN(CH2)3NPh)}Zr3Cl2(μ2-Cl)(μ2-i-Pr2P–P)2(μ3-i-Pr2P–P)2]−[Li(DME)3]+, was obtained in which the i-Pr2P–P ligands exhibit bridging coordination.
Photoactivity of decahedral TiO2 loaded with bimetallic nanoparticles: Degradation pathway of phenol-1- 13 C and hydroxyl radical formation
- Magdalena Diak
- Marek Klein
- Tomasz Klimczuk
- W. Lisowski
- Hynd Remita
- Adriana Zaleska-Medynska
- Ewelina Grabowska
2017 APPLIED CATALYSIS B-ENVIRONMENTAL
Decahedral TiO2decorated with bimetallic nanoparticles were synthesized via radiolysis and photode-position method. The effect of bimetallic surface composition (Ag Pt, Ag Au, Au Pd, Au Pt) as well asdeposition technique (simultaneous or sequential) on the photocatalytic activity in phenol degradationand efficiency of hydroxyl radicals generation under UV–vis light irradiation were investigated. Modifiedand pristine decahedral TiO2anatase with exposed {001} were characterized by X-ray diffraction (XRD),diffuse reflectance spectroscopy (DRS), transmission electron microscopy (TEM) with energy-dispersiveX-ray (EDX) spectroscopy, scanning electron microscopy (SEM), inductively coupled plasma-massspectrometry (ICP-MS) and X-ray photoelectron spectroscopy (XPS). The gas chromatography-mass spec-trometry was employed to detect organic intermediates to establish degradation pathway of isotopicallylabeled (1-13C) phenol. The modification with Pt and Ag nanoparticles induced an increase in photocat-alytic activity of phenol degradation under UV–vis light irradiation (79% of phenol was degraded after90 min of irradiation). The main by-products detected in phenol oxidation were catechol, hydroquinone,malonic, fumaric and maleic acid. The results indicated the formation of isotopically labeled and unlabeledmaleic acid. It was noticed that all samples sequentially photodeposited on TiO2surface exhibited higher•OH radicals generation compared to pristine TiO2. Our results suggest that synergistic effects betweenspecifically engineered TiO2nanocrystals and unique properties of loaded bimetallic nanoparticles canenhance the charge separation of photoinduced carriers.
Photocatalytical degradation of toluene and cyclohexane using LED illumination
- Joanna Mioduska
- Anna Zielińska-Jurek
- Jan Hupka
2017 Pełny tekst POLISH JOURNAL OF ENVIRONMENTAL STUDIES
A sol-gel process followed by hydrothermal reaction was used to prepare coupled WO3-TiO2 photocatalysts with varying amounts of WO3 in respect to TiO2 (3 mol% and 5 mol% respectively). Additionally, photocatalysts have been subjected to different calcination temperatures of 400ºC and 800ºC, which allowed us to compare how these affect photodegradation efficiency. Photocatalysts were characterized under a scanning electron microscope, x-ray diffraction, and by measuring BET surface area. Photocatalytic tests have been carried out following the degradation of toluene and cyclohexane in the gas phase under LED UV light (375 nm). Elevated calcination temperature turned to enhance photocatalytical efficiency of coupled WO3-TiO2 while degrading the model pollutant cyclohexane. It was demonstrated thatlight emitting diodes (LEDs) can be used effectively as a source of illumination in photoreactors, sufficient to obtain 90% compound elimination from the air during 15 minutes of illumination while applying a wellmatched photocatalyst.
Photocatalytical properties of maze-like MoO3 microstructures prepared by anodization of Mo plate
- Mariusz Szkoda
- Konrad Trzciński
- Katatrzyna SiuzdaK
- Anna Lisowska-Oleksiak
2017 ELECTROCHIMICA ACTA
In this work, we present a simple method of the formation of MoO3 microstructures via an electrochemical anodization of Mo plate carried out under varied conditions. The morphology, composition and structure of samples were investigated by SEM, EDX, XRD and Raman spectroscopy. The band gap energy was estimated using the Kubelka–Munk function and was found to be 2.87 eV. Finally, the photocatalytic activities of MoO3 samples were evaluated using the decolorisation of methylene blue (MB) as a model organic contamination. Additionally, photostability of the materials were verified and the formation of hydroxyl ions was investigated by photoluminescence (PL) spectra of terephthalic acid as a probe molecule. Various conditions of MB decolorization allow the main mechanism of dye decomposition to be identified. It was shown that the presence of F− during anodization positively affects photocatalytic properties of tested samples. After 2 h of constant illumination, the degradation reached 34% of the initial value of MB when α-MoO3 (prepared without F−) was used as photocatalyst, whereas the degradation efficiency equals 57% in the case of α-MoO3 (with F−). Furthermore, photoluminescence intensity of the 2-hydroxyterephthalic acid formed in the presence of α-MoO3(F−) was higher comparing to the intensity of spectra recorded in the presence of α-MoO3.
Photocatalytically Active TiO2/Ag2O Nanotube Arrays Interlaced with Silver Nanoparticles Obtained from the One-Step Anodic Oxidation of Ti–Ag Alloys
- Paweł Mazierski
- Anna Malankowska
- Marek Kobylański
- Diak Magdalena
- Magda Kozak
- Michał Jerzy Winiarski
- Tomasz Klimczuk
- Wojciech Lisowski
- Grzegorz Nowaczyk
- Adriana Zaleska-Medynska
2017 ACS Catalysis
The development of a photocatalyst with remarkable activity to degrade pollutants in aqueous and gas phase requires visible lightresponsive stable materials, easily organized in the form of a thin layer (to exclude the highly expensive separation step). In this work, we present a one-step strategy for synthesizing material in the form of a self-organized TiO2/Ag2O nanotube (NT) array interlaced with silver nanoparticles (as in a cake with raisins) that exhibited photoactivity significantly enhanced compared to that of pristine TiO2 NTs under both ultraviolet (UV) and visible (vis) irradiation. An NT array composed of a mixture of TiO2 and Ag2O and spiked with Ag nanoparticles was formed via the anodization of a Ti−Ag alloy in a one-step reaction. Silver NPs have been formed during the in situ generation of Ag ions and were (i) embedded in the NT walls, (ii) stuck on the external NT walls, and (iii) placed inside the NTs. The enhancement of photocatalytic efficiency can be ascribed to the existence of an optimal content of Ag2O and Ag NPs, which are responsible for decreasing the number of recombination centers. In contrast to UV−vis light, performance improvement under vis irradiation occurs with increasing Ag2O and Ag0 contents in the TiO2/Ag2O/Ag NTs as a result of the utilization of larger amounts of incident photons. The optimized samples reached phenol degradation rates of 0.50 and 2.89 μmol dm−3 min−1 under visible and UV light, respectively, which means degradation activities 3.8- and 2-fold greater than that of the reference sample, respectively, remained after four photodegradation cycles under UV light.
Photoelectron spectroscopy of a series of acetate and propionate esters
- Małgorzata Śmiałek-Telega
- Julien Guthmuller
- Michael MacDonald
- Lucia Zuin
- Jacques Delwiche
- Marie-Jeanne Hubin-Franskin
- Tadeusz Lesniewski
- Nigel J. Mason
- Paulo Limão-Vieira
2017 JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
The electronic state and photoionization spectroscopy of a series of acetate esters: methyl acetate, isopropyl acetate, butyl acetate and pentyl acetate as well as two propionates: methyl propionate and ethyl propionate, have been determined using vacuum-ultraviolet photoelectron spectroscopy. These experimental investigations are complemented by ab initio calculations. The measured first adiabatic and vertical ionization energies were determined as: 10.21 and 10.45 eV for methyl acetate, 9.99 and 10.22 eV for isopropyl acetate, 10.07 and 10.26 eV for butyl acetate, 10.01 and 10.22 eV for pentyl acetate, 10.16 and 10.36 eV for methyl propionate and 9.99 and 10.18 eV for ethyl propionate. For the four smaller esters vibrational transitions were calculated and compared with those identified in the photoelectron spectrum, revealing the most distinctive ones to be a Csingle bondO stretch combined with a Cdouble bond; length as m-dashO stretch. The ionization energies of methyl and ethyl esters as well as for a series of formates and acetates were compared showing a clear dependence of the value of the ionization energy on the size of the molecule with very little influence of its conformation.
Photogrammetric and total station's measurement of compressed column's model
- Tadeusz Widerski
- Karol Daliga
2017
Modelling studies continue to play an important role. One of such study is stress determination in the reinforcement bars of reinforced columns and determine column's axis deformation. The article presents measurements results of control points located on the model of reinforced concrete column. The column was compressed in few series till it's destruction. In this studies, photogrammetric method and total station measurements were used. The main goal was to use photo points located around column with known coordinates to calculate coordinates of marked points on the column and perform surface model of the column. Based on obtained column's surface, column axis was approximated. In addition, based on total station measurements, axis approximation also was performed. There were also conducted a simplified analysis of measurement uncertainty. Based on results for each series of load, deformation over time analyses was performed. Comparison of used methods was performed. Some attention was also drawn to the factors affecting the accuracy of photogrammetric measurement.
Photophysical processes in the selected white organic light-emitting diodes
- Wojciech Mróz
2017 Pełny tekst
The first part discusses history of organic emitters, the scope of the work, phenomena in molecular systems, types of architectures in OLEDs, types of OLEDs emitting white light with examples from the literaturę and a description of the parameters chcracterizing LEDs. The second part describes materials, production of the samples, the measurement systems and results. In chapter 8.1 the results for the OLEDs based on emission from dendrons with pyrene antennae are presented. Suitable chromophore concentration allowed to obtain emission from pyrene excimer and acceptor moiety of the dendrons, together creating white light. Chapter 8.2 describes the results for green and red emitting diodes with complexes of terbium and europium, and those for the WOLED. It is discussed energy transfer mechanism and the diffusion coefficients of excitons in the matrix and their diffusion lengths were determined. In chapter 8.3 the results obtained for diodes with organic platinum complexes are presented. Mechanisms responsible for decrease of the external quantum efficiency are discussed and from comparison with theoretical models annihilation constant was determined for the triplet-triplet annihilation proces. It was built and characterized double-layer white light-emitting diode employing emissions of the monomers and excimers of the Platinum complex.
Photovoltaic module temperature stabilization with the use of phase change materials
- Ewa Klugmann-Radziemska
- Patrycja Wcisło-Kucharek
2017 Pełny tekst SOLAR ENERGY
The worldwide growth of photovoltaics (PVs) has formed an exponential curve for more than four decades. During this period of time, PVs have evolved from a pure niche market of small-scale applications towards becoming a mainstream electricity source. The influence of temperature on the electrical parameters of crystalline silicon solar cells and solar modules is well described in the literature. In order to diminish these effects, it is useful to decrease the module temperature by removing the heat in a hybrid system that combines a PV module and thermal collector (T) into a photovoltaic–thermal (PV/T) system. Two types of PV/T systems are popular on the market: air cooled and water cooled. A relatively new solution is the use of phase change material (PCM) in order to pick up excess heat. PCMs absorb, store, and release large amounts of energy in the form of latent heat at constant temperature. Many innovative applications can be found for PCMs, which raise the efficiency of equipment, among other advantages. In the present paper, the experience of using PCMs for the stabilization of PV module temperature is presented. The results of these experiments are promising: for constant solar irradiance, the modified solar PV module (PV/PCM) heats up to a lower temperature than the unmodified PV module and the cheapest option is to apply 42–44 paraffin to the module without cooling, which made possible to lower the temperature of the module by 7 K. During the experiment, the lowered temperature was maintained for more than 5 h, allowing the PV module to work at a temperature close to the optimum one for the entire period of intense lighting.
PHYSICAL MODELLING OF GEOTECHNICAL STRUCTURES IN PORTS AND OFFSHORE
- Lech Bałachowski
2017 Pełny tekst Polish Maritime Research
The physical modelling of subsoil behaviour and soil-structure interaction is essential for the proper design of offshore structures and port infrastructure. A brief introduction to such modelling of geoengineering problems is presented and some methods and experimental devices are described. The relationships between modelling scales are given. Some examples of penetration testing results in centrifuge and calibration chamber are presented. Prospects for physical modelling in geotechnics are also described.
Piezoelectric Transducer for Mechanical Assessment of Soft Tissues. Concept, Implementation and Analysis
- Łukasz Sienkiewicz
2017
The main goal of this work was following: preparation of a new concept, implementation and analysis of the piezoelectric resonant sensor/actuator for measuring the aging process of human skin. The research work has been carried out in the framework of cooperation between the INP-ENSEEIHT-LAPLACE, Toulouse, France, and at the Gdansk University of Technology, Faculty of Electrical and Control Engineering, Research Group of Power Electronics and Electrical Machines, Gdańsk, Poland. A concept of transducer for the characterization of mechanical properties of soft tissues was presented. The piezoelectric resonant, bending transducer, referred to as “unimorph transducer” was chosen from different topologies of piezoelectric benders based on the fulfillment of the stated requirements. The innovation of the project lies in the integration of the dynamic indentation method by using a unimorph as an indentation device. This allows the use of a number of attractive electromechanical properties of piezoelectric transducers. This work is divided into seven chapters. Chapter 1 states the thesis and goals of the dissertation. Chapter 2 presents piezoelectric phenomenon and piezoelectric applications in the fields of medicine and bioengineering. Chapter 3 describes the requirements for the developed transducer. The choice of unimorph transducer is justified. Chapter 4 presents an analytical description of the unimorph transducer, including the calculations of static deformations, equivalent circuit description, and description of the contact conditions between the transducer and the tested materials. Chapter 5 contains the numerical analysis of the unimorph transducer using FEM virtual model. Results of static and modal simulations are described for two considered geometries of the transducer. Chapter 6 describes the experimental verification process of analytic and numerical models developed for unimorph transducer. The final chapter includes general conclusions concerning obtained research results and achievements, as well as possible future works.
Pilot Testing of Developed Multimodal Biometric Identity Verification System
- Piotr Bratoszewski
- Andrzej Czyżewski
- Piotr Hoffmann
- Michał Lech
- Maciej Szczodrak
2017
The bank client identity verification system developed in the course of the IDENT project is presented. The total number of five biometric modalities including: dynamic signature proofing, voice recognition, face image verification, face contour extraction and hand blood vessels distribution comparison have been developed and studied. The experimental data were acquired employing multiple biometric sensors installed at engineered biometric terminals. The biometric portraits of 125 subjects were registered and stored in the database during the presented pilot study and then verified experimentally. The analysis of FAR and FRR measures obtained for developed biometric applications was made. Problem-specific survey was done on the basis of questionnaires completed by the subjects in order to assess the look and feel of the developed biometric system as well as to collect opinions concerning its implementation in banking outlets. A discussion concerning the quality of registered signals and results achieved in the pilot study is included.
Piotr Lorens — Challenges for Spatial Development and Planning – Outlook from a Post-socialist Country
- Piotr Lorens
2017 Pełny tekst disP
The article includes reflections regarding challenges for spatial development as seen from the perspective of the transformation country. The perspective of the Polish development challenges are taken into account.
Planning, Configuration and Usefulness of Microseismic Monitoring on Eastern-Europe Platform – Example from East Pomerania
- Mateusz Kmieć
- Michał Antoszkiewicz
- Paweł Szewczuk
- Marek Szkodo
- Robert Jankowski
2017
The microseismic monitoring is a method of monitoring of fracture propagation during hydraulic fracturing process. The method uses array of geophones to localize micro tremors induced by liquid pumped underground at high rate and pressure. The acquired information helps to optimize fracturing process and prevents fracture growth to aquifer levels. It proved to be useful on several unconventional hydrocarbon reservoirs in the USA. Conducted investigation was aimed at evaluation of the possibility of using the technology on Polish unconventional reservoirs. In order to stand better chances of success the analysis of several variants of monitoring was made. East Pomerania geological structure was compared to similar structures in the USA. With this knowledge, financially feasible configuration was selected. The array of geophones was dispatched around the drilling site and data acquisition was performed. The present paper is mainly focused on geological structure, hardware selection, damping factor and noise level analysis. The usefulness of receiver configuration is also assessed.
Planowanie realizacji projektów w środowisku wieloprojektowym z wykorzystaniem metody łańcucha krytycznego
- Jolanta Łopatowska
2017 Pełny tekst Zeszyty Naukowe. Organizacja i Zarządzanie / Politechnika Śląska
Metoda CCMPM (Critical Chain Multi Project Management) pozwala zarządzać projektami w środowisku wieloprojektowym zgodnie z zasadami teorii ograniczeń TOC. Poprzez zsynchronizowanie projektów względem terminów zadań wykorzystujących zasób ograniczający pozwala na maksymalne jego wyeksploatowanie. Bufor ograniczenia chroni termin wykonania zadania przez zasób ograniczający w kolejnym projekcie. W artykule przedstawiono schemat postępowania w procesie planowania realizacji projektów w środowisku wieloprojektowym zgodnie z metodą CCMPM. Przedstawiony przykład ilustruje realizację tych zasad.
Plasma-Based Deposition and Processing Techniques for Optical Fiber Sensing
- M. Dominik
- M. Koba
- Robert Bogdanowicz
- W. Bock
- M. Śmietana
2017
Plasma-based techniques are widely applied for well-controlled deposition, etching or surface functionalization of a number of materials. It is difficult to imagine fabrication of novel microelectronic and optoelectronic devices without using plasma-enhanced deposition of thin films, their selective etching or functionalization of their surfaces for subsequent selective binding of chemical or biological molecules. Depending on the process parameters, i.e., generator frequency and power, composition of gases , pressure, temperature, and applied substrates, different effects of the process can be obtained. The chapter discusses current trends in application of plasma-based techniques for fabrication of novel optical sensing devices. Fabrication of materials with different structure (from amorphous to crystalline, porous, and multilayers), optical properties (absorption, refractive index ), and surface activity, as well as their processing are reviewed. Application of the plasma methods enhancing sensing properties of various optical fiber sensing structures, namely long-period gratings, intermodal interferometers based on photonic crystal fiber, sensing structures based on lossy mode resonance or stacks of nano-films are given as examples and are discussed.
Platforma eNauczanie – miejsce na edukację i spotkania – warto profesjonalnie dzielić się wiedzą
- Anita Maria Dąbrowicz-Tlałka
2017 Pismo PG
Każda z uczelni w Polsce korzysta z rozwiązań technologicznych pozwalających na organizowanie i wspomaganie nauczania przez Internet. Są to tzw. platformy edukacyjne. Podstawowe zadanie tych rozwiązań, będących czasami zaawansowanymi systemami, polega na gromadzeniu materiałów dydaktycznych, ich organizowaniu i udostępnianiu odbiorcom przez Internet. Spopularyzowanie swojej marki w Internecie to jedno, ale zapewnienie sobie dobrej pozycji na rynku to zupełnie inna sprawa. Prowadzenie działalności w branży edukacyjnej wymaga uwiarygodnienia siebie jako profesjonalisty w danej dziedzinie oraz świetnego nauczyciela, który potrafi przekazać najnowszą wiedzę oraz zachęcić swoich studentów do podnoszenia kompetencji. Tylko kompleksowe systemy zarządzania wiedzą dają możliwość oceny umiejętności w zakresie różnych bloków tematycznych, kontroli postępów, budowania inteligentnego systemu wsparcia i weryfikacji. Tylko dobrze przemyślane i funkcjonalne rozwiązania edukacyjne pomagają w budowaniu marki uczelni i zachęcaniu przyszłych studentów do nauki – a dzięki Internetowi dzieje się to nie tylko w kraju, ale i za granicą. Przecież wiadomo, że dobra pozycja uczelni opiera się na wiedzy, umiejętnościach i profesjonalizmie pracowników otwartych na świat i nowe możliwości, jakie stwarza technologia.
Platforma IPMed jako elastyczne źródło danych dla medycznych zespołów naukowych
- Tomasz Dziubich
2017 Pełny tekst Roczniki Kolegium Analiz Ekonomicznych
Przedstawiono architekturę rozproszonej platformy IPMed, która umożliwia akwizycję i przechowywanie zanonimizowanych danych medycznych. Pokazano wyniki zastosowania platformy w obszarze badań z zakresu hemodynamiki układu krążenia. Uzyskane dane pozwoliły na weryfikację hipotezy zespołu badawczego i określenie reguł rekomendacji w z leczeniu udarów.
Playback Attack Detection: The Search for the Ultimate Set of Antispoof Features
- Maciej Smiatacz
2017
Automatic speaker verification systems are vulnerable to several kinds of spoofing attacks. Some of them can be quite simple – for example, the playback of an eavesdropped recording does not require any specialized equipment nor knowledge, but still may pose a serious threat for a biometric identification module built into an e-banking application. In this paper we follow the recent approach and convert recordings to images, assuming that original voice can be distinguished from its played back version through the analysis of local texture patterns. We propose improvements to the state-of-the-art solution, but also show its severe limitations. This in turn leads to the fundamental question: is it possible to find one set of features which are characteristic for all playback recordings? We look for the answer by performing a series of optimization experiments, but in general the problem remains open.
Playback detection using machine learning with spectrogram features approach
- Jerzy Dembski
- Jacek Rumiński
2017 Pełny tekst
This paper presents 2D image processing approach to playback detection in automatic speaker verification (ASV) systems using spectrograms as speech signal representation. Three feature extraction and classification methods: histograms of oriented gradients (HOG) with support vector machines (SVM), HAAR wavelets with AdaBoost classifier and deep convolutional neural networks (CNN) were compared on different data partitions in respect of speakers or playback devices: for instance with different speakers in training and test subsets. The playback detection systems were trained and tested on two speech datasets S1 and S2 manufactured independently by two different institutions. The test error for both datasets oscillates about the level of 1% for HOG+SVM and even below it for CNN in bigger S1 base. In cross validation scenario in which one base was used for training and second base for the test the results were very poor what suggests that the information relevant for playback detection appeared in each base in different way.