2012 - Repozytorium publikacji - Politechnika Gdańska

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Publikacje z roku 2012

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Expression of Deinococcus geothermalis Trehalose Synthase Gene in Escherichia coli and Its Enzymatic Properties
- Paweł Filipkowski
- Anna Panek
- Agnieszka Felczykowska
- Olga Pietrow-Tobiszewska
- Józef Synowiecki
2012 AFRICAN JOURNAL OF BIOTECHNOLOGY
A novel trehalose synthase gene from Deinococcus geothermalis (DSMZ 11300) containing 1,692 bp reading-frame encoding 564 amino acids was amplified using PCR. The gene was ligated into pET30Ek/LIC vector and expressed after isopropyl alfa-D-thiogalactopyranoside induction in Escherichia coli BL21(DE3)pLysS. The recombinant trehalose synthase (DgeoTreS) containing a His6 tag at the C-terminus was purified by metal affinity chromatography and characterized. The expressed enzyme is a homodimer with deduced molecular mass of 64.69 kDa for each subunit and exhibits the highest activity at pH and temperature of 7.6 and 40C, respectively. The activity of DgeoTreS was almost unchanged after 8 h preincubation at 40C and pH 7.6, and retained about 57 % of maximal value after 8 h of incubation at 55C. The DgeoTreS was highly inhibited by Cu2+, Hg2+ and 10 mM Tris as well as by EDTA when its concentration exceeded 1 mM, but slightly activated by 1 mM dithiotreitol. The Km and kcat values of maltose conversion were 254 mM and 31.86 s-1, respectively.
Extendable Safety and Security Ontology
- Tomasz Maria Boiński
- Henryk Krawczyk
2012 Pełny tekst Studies & Proceedings of Polish Association for Knowledge Management
Security plays an increasingly important role in our everyday life, and research and users of computer systems point out that the need arises for a common, formalised model capable of integrating different solutions. In this paper we show that an ontology can be designed and created in a way that will make it suitable for interoperability and integration. A security and safety ontology and the methodology for creating a common model allowing future expandability and reuse are considered. such interoperable ontologies can be easily integrated with current and future solutions and provide principles for increasing system interoperability.
Extensions of ETSI performance measurements methodology for statistical results analysis =Rozszerzenia metodologii pomiarów wydajności zaproponowanej przez ETSI przy statystycznej analizy wyników
- Sylwester Kaczmarek
- Magdalena Młynarczuk
- Marcin Narloch
- Maciej Sac
2012 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne
Next Generation Network (NGN) architecture was proposed by International Telecommunication Union Telecommunication Standardization Sector (ITU-T) to deliver telecommunication services satisfying the needs of modern society for an access to information. The core of NGN service stratum are IP Multimedia Subsystem (IMS) elements acting as service controls units. To assess performance of IMS components, European Telecommunications Standards Institute standardized a testing methodology, which can be also easily adopted to other network architectures. In the paper a proposition of statistical extensions of the ETSI methodology is presented. The main idea of the extensions is to evaluate system under test performance based on statistical result analysis including mean value and confidence intervals of performance metric instead of using instantaneous metric values susceptible to random factors. The extended methodology is applied and verified in performance measurements of ASON/GMPLS connection control layer in the implemented laboratory testbed.
Extinction Event Concepts for the Evolutionary Algorithms
- Bartosz Jaworski
- Łukasz Kuczkowski
- Roman Śmierzchalski
- Piotr Kolendo
2012 Pełny tekst Przegląd Elektrotechniczny
The main goal of this present paper is to propose a structure for a tool helping to determine how algorithm would react in a real live application, by checking it's adaptive capabilities in an extreme situation. Also a different idea of an additional genetic operator is being presented. As Genetic Algorithms are directly inspired by evolution, extinction events, which are elementary in our planet's development history, became a foundation for those concepts.
Extracted window offsetting using maximally flat fractional delay filter
- Marek Blok
2012
W pracy przedstawiono koncepcję projektowania filtru ułamkowoopóźniającego (FD) z wykorzystaniem metody okien offsetowanych. W zaproponowanym podejściu jako okna prototypowego, offsetowanego o opóźnienie ułamkowe projektowanego filtru, użyto okna wyodrębnionego z odpowiedzi impulsowej filtru optymalnego. Zaprojektowane w ten sposób filtry FD nie są optymalne jednak zapewniają lepszą jakość algorytmu zmiany szybkości próbkowania (SRC) bazującego na nim. Główną zaletą jest eliminacja silnych listków bocznych w paśmie zaporowym zbiorczego filtru interpolacyjnego, które są typowe SRC z użyciem filtrów optymalnych. Dodatkowo użycie okien offsetowanych pozwala na swobodne określenie położenia pasma przejściowego zbiorczego filtru interpolacyjnego.
Eye Blink Based Detection of Liveness in Biometric Authentication Systems Using Conditional Random Fields
- Mariusz Szwoch
- Paweł Pieniążek
2012
The goal of this paper was to verify whether the conditional random fields are suitable and enough efficient for eye blink detection in user authentication systems based on face recognition with a standard web camera. To evaluate this approach several experiments were carried on using a specially developed test application and video database.
Fabrication and structural properties of Y and Fe co-doped SrTiO3 nanoceramics for SOFC
- Tadeusz Miruszewski
2012
Yttria and iron co-doped strontium titanate perovskites, (Y0,07Sr0,93Ti1-xFexO3-δx=0,1; 0,2) samples were fabricated by two methods: solid-state synthesis (SS) and the Pechinisol-gel modified method. The morphology of samples were measured by SEM and X-raydiffraction. Results were compared and discussed. The strong relationship between fabricationprocedure and microstructure has been proven. It was also observed, that the nanoceramicsobtained by Pechini method has microstructure, required for application in Solid Oxide FuelCell electrodes.
Fabrication and Study of BiNbO4 Ceramics
- Agata Lisińska-Czekaj
- Dionizy Czekaj
2012 Key Engineering Materials
Aim of the present research was to fabricate and study crystalline structure as well as dielectric properties of BiNbO4 ceramics. In the present study BiNbO4 ceramics was fabricated by solid state reaction from the mixture of simple oxides viz. Bi2O3, and Nb2O5. Stoichiometric mixture of the powders was thermally analyzed so parameters of the thermal treatment were determined. The EDS measurements proved conservation of the chemical composition of the ceramic powder after calcination (T=800°C). Free sintering at T=870 – 1080 °C was used for fabrication of the ceramic samples. Morphological analysis using scanning electron microscopy was performed. The crystalline structure of the sintered samples were examined by X-ray diffraction method at room temperature. It was found that for low temperature of sintering (T0C) bismuth niobate crystallized in orthorhombic symmetry Pnna (52) whereas for high sintering temperature (T>1000 °C) BiNbO4 exhibited anorthic symmetry P-1 (2). Low frequency (ν=100Hz – 1MHz) impedance spectroscopy was applied to study influence of the sintering temperature on dielectric properties of bismuth niobate at room temperature. The equivalent circuit method was used for analysis of the impedance data.
Fabrication of Bi6Fe2Ti3O18 Ceramics by Mixed Oxide Method
- Agata Lisińska-Czekaj
2012 MATERIALS SCIENCE FORUM
In the present study Bi6Fe2Ti3O18 (BFTO) ceramics has been fabricated by solid state reaction from the mixture of simple oxides viz. Bi2O3, TiO2 and Fe2O3. Stoichiometric mixture of the powders was thermally analyzed so parameters of the thermal treatment were determined. The EDS measurements have shown conservation of the chemical composition of the ceramic powder after calcination. Hot-pressing method was used for final densification of ceramic samples. The crystalline structure of the sintered samples was examined by X-ray diffraction method at room temperature. It was found that BFTO ceramics sintered at T=980 °C adopted the orthorhombic structure of Aba2 (41) space group with the following elementary cell parameters: a=5.4567(2)Å, b=49.418(2) and c=5.4826(2). Details concerning the atom’s positions are presented.
Fabrication of La-Doped Bi4Ti3O12 Ceramics
- Agata Lisińska-Czekaj
- Henryk Bernard
- Katarzyna Osińska
- Jolanta Dzik
- Dionizy Czekaj
2012 MATERIALS SCIENCE FORUM
La-modified Bi4Ti3O12 is a typical ferroelectric, piezoelectric and electro-optic material, having relatively low coercive field, low dielectric constant, high Curie temperature and high breakdown strength. Goal of the present research was to apply mixed oxide method for fabrication of BiTLax ceramics, study its chemical composition, crystalline structure and microstructure. The compound BiTLax for x=0, 0.25, 0.5, 0.75 ceramic powders were prepared from mixture of oxides by a solid state reaction at T=1000°C for t=3h. Ceramic powders of BiTLax were next press and the compacts were sintered by the free sintering at temperature T=1000°C with the soaking time t=2h. A crystal structure Bi-layered structured of ferroelectrics was confirmed by a X-ray diffraction. It was found that La-doped BiT ceramics sintered at T=1000°C adopted the monoclinic symmetry. Influence of La-doping on chemical composition and microstructure of BiTLa ceramics was studied by scanning electron microscopy HITACHI S-4700 and energy dispersion spectroscopy.
Factors affecting the quality of bottled water
- Malwina Diduch
- Żaneta Polkowska
- Jacek Namieśnik
2012 Journal of Exposure Science and Environmental Epidemiology
The ever-increasing popularity of bottled water means that it is important to analyze not only its mineral content but also, above all,its content of possible contaminants, especially the organic ones. In this respect, bottled waters are a special case, because apartfrom organic chemical contaminants derived from the well from which they were acquired, their secondary contamination is alwayspossible, during treatment or storage or transport in unsuitable conditions (sunlight and elevated temperature). This paperdescribes how various factors, from the area around the well, and the method of drawing and treating water, to the manner inwhich the finished product is stored and transported may affect the quality of bottled waters. It also summarizes literatureinformation on the levels of organic contaminants in various kinds of bottled water samples.
Factors disturbing Internet usage in opinion of elderly users
- Jacek Wachowicz
- Bohdan Ludwiszewski
- Krzysztof Redlarski
2012
Internet became truly widespread in modern societies. This created its huge economic potential, which is widely used, especially in traditionally communication-oriented societies like USA and Scandinavian countries. This trend enables to create economic growth even despite of worldwide economic slowdown.Together with demographic changes this raise the necessity of research on how older users perceive modern, Internet-based tools and products and which factors disturb them. This seems to be vital in order to let older users effectively use modern tools and products. In this paper authors discuss basic factors that led to this situation. It is followed by outcomes of research driven in Poland in April 2012 on elderly students. This allowed to identify and discuss most irritating factors in Internet use for elderly Internet users.
Factors that strengthen and weaken the identity of the cluster structures
- Anna Lis
- Adrian Lis
2012
The main aim of this paper is the application of "identity" to the issues related to "clustering process" and particularly - to the cooperation in the clusters and the cluster initiatives. The authors distinguish these factors that have the greatest influence on the formation and maintenance of identity in mentioned networks of cooperation.
Failure model of main elements of the ship engine crankshaft-piston assembly
- Piotr Bzura
2012 Pełny tekst Journal of Polish CIMEEAC
The paper presents a failure model of main elements of the crankshaft-piston assembly, based on failures ofcrankshaft-piston assembly and timing gear system of the Sulzer RD engines, retrieved from the equipment reliabilitydata of selected ships.
Failure of austenitic stainless steel tubes during steam generator operation
- Santina Topolska
- Jerzy Łabanowski
- Maria Głowacka
2012 Pełny tekst Journal of Achievements in Materials and Manufacturing Engineering
The article presents the failure process of austenitic stainless steels used in power devices, such as heat exchangers, steam generators, in terms of local corrosion: pitting, stress and intergranular corrosion, paying particular attention to welded joints area. The effect of steel chemical composition, microstructure, welding process and work environment was analyzed. The second part of the article presents the results of the metallographic investigations conducted on the damaged steam generator coil performed with the use of light microscope and scanning electron microscope equipped with the EDS analysis device. On the base of obtained results some recommendations have been define relating to steel grade selection, processing (welding) technology, and the working environment, in order to increase the life time of power generation equipment.
Fala stojąca Stokesa - aproksymacja ciśnienia hydrodynamicznego 2 czy 5 rzędu?
- Waldemar Magda
2012 Inżynieria Morska i Geotechnika
Omówienie rozwiązania dla ciśnienia hydrodynamicznego pod falą stojącą Stokesa metodą perturbacji. Numeryczna analiza porównawcza rozwiązania dla oscylacji ciśnienia hydrodynamicznego w aproksymacji drugiego i piątego rzędu. Analiza porównawcza siły hydrodynamicznej obciążającej falochron pionowościenny, obliczonej zgodnie z aproksymacją fali stojącej Stokesa 2 i 5 rzędu.
Fala stojąca Stokesa - krytyczna analiza wzorów wynikających z aproksymacji 2 rzędu
- Waldemar Magda
2012 Inżynieria Morska i Geotechnika
Poprawne postaci wzorów na: rzędną swobodnej powierzchni, wzniesienie poziomu falowania i ciśnienie hydrodynamiczne, dla przypadku fali stojącej Stokesa 2 rzędu. Krytyczna ocena niektórych wzorów występujących w literaturze na podstawie wyników analiz porównawczych.
Falistość powierzchni obrobionych przez nagniatanie
- Stefan Dzionk
- Włodzimierz Przybylski
2012 Archiwum Technologii Maszyn i Automatyzacji
Powierzchnię po obróbce wykończeniowej definiuje się zazwyczaj za pomocą parametrów chropowatości. Rosnące wymagania jakościowe w stosunku do wytwarzanych części maszyn powodują rozszerzanie się zakresu parametrów opisujących powierzchnię. W artykule przedstawiono ocenę jakościową powierzchni nagniatanych za pomocą parametrów falistości.
Fast frequency sweep based on the model order reduction technique for calculating scattering parametersjinjFDFDj
- Jakub Podwalski
- Michał Mrozowski
2012
Artykuł prezentuje ulepszoną, efektywną metodę przemiatania częstotliwościowego dla metody FDFD. Liczba równań opisujących analizowaną strukturę jest redukowana za pomocą metody redukcjirzędu modeli, a następnie macierz wynikowa jest diagonalizowana. Kosztowne czasowo odwracanie dużych macierzy jest zastąpione prostym mnożeniem małej macierz diagonalnej przez wektor. Zaprezentowana metoda przemiatania częstotliwościowego może być róznież użyta w przypadku analizy za pomocą FDFD z użyciem makromodeli.
Fast implementation of FDTD-compatible green's function on multicore processor
- Tomasz Stefański
2012 IEEE Antennas and Wireless Propagation Letters
In this letter, numerically efficient implementation of the finite-difference time domain (FDTD)-compatible Green's function on a multicore processor is presented. Recently, closed-form expression of this discrete Green's function (DGF) was derived, which simplifies its application in the FDTD simulations of radiation and scattering problems. Unfortunately, the new DGF expression involves binomial coefficients, whose computations may cause long runtimes and numerical problems. The proposed fast implementation of the DGF is based on the multiple precision arithmetic and employs a common programming language extended with the OpenMP parallel programming interface. As a result, the speedup factor of three orders of magnitude compared to the previous implementation was obtained, thus applicability of the DGF in FDTD simulations was significantly improved.