2014 - Repozytorium publikacji - Politechnika Gdańska

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Publikacje z roku 2014

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237Np Mössbauer effect study on NpFeAsO
- P. Gaczyński
- Tomasz Klimczuk
- H. Walker
- R. Springell
- E. Colineau
- R. Eloirdi
- J-C. Griveau
- R. Caciuffo
2014 JOURNAL OF PHYSICS-CONDENSED MATTER
We report 237Np Mössbauer measurements on NpFeAsO. The Np atoms were found to occupy only one crystallographic site. The value of the isomer shift (δ ∼ 9.1 mm s−1 versus NpAl2) indicates a 5f4 electronic configuration (Np3+ ions). The magnetic ordering of the Np sublattice below 60 K is established and the saturated ordered magnetic moment is determined to be 1.73μB at 3.6 K. The unique set of hyperfine parameters exclude a modulated magnetic structure or spin waves on the Np site. The neptunium magnetic moments μNp are found to lie along the tetragonal c-axis.
30 lat aplikacji metody hydrofitowej na Pomorzu - postęp i badania
- Hanna Obarska-Pempkowiak
- Magdalena Gajewska
- Ewa Wojciechowska
- Katarzyna Kołecka
- Arkadiusz Ostojski
2014 Pełny tekst Inżynieria Morska i Geotechnika
Aktualnym dążeniem wszystkich działań związanych z szeroko pojętą gospodarką komunalną jest uwzględnienie zasady zrównoważonego rozwoju tak, aby zaspokajać potrzeby ludności bez pomniejszania zasobów dla przyszłych pokoleń. Zasada zrównoważonego rozwoju polega na wykorzystaniu najlepszych dostępnych technik i praktyk, które pomagają rozwijać się społecznościom, bez uszczerbku dla środowiska przyrodniczego. Systemy hydrofitowe nazywane często systemami „zielonymi”, z powodu małego zapotrzebowania na energię, stanowią proekologiczną alternatywę dla konwencjonalnych systemów w oczyszczaniu różnych rodzajów ścieków. Obiekty hydrofitowe wykorzystywane są w gospodarce komunalnej do oczyszczania i podczyszczania ścieków: komunalnych, deszczowych i różnych rodzajów przemysłowych, do odwadniania i stabilizacji osadów ściekowych, a także w szeroko pojętej ochronie wód. Usuwanie zanieczyszczeń w systemach hydrofitowych zachodzi dzięki procesom fizycznym, chemicznym i biologicznym. Procesy te zachodzą w środowisku wodno-roślinnym lub gruntowo-roślinnym. W systemach tych dzięki obecności hydrofitów (roślin wodnych i wodolubnych) tworzą się specyficzne warunki umożliwiające rozwój różnorodnych mikroorganizmów. W rezultacie następuje intensyfikacja procesów utleniania i redukcji, odpowiedzialnych za przebieg procesów zarówno w warunkach tlenowych, jak i beztlenowych. Procesy te są intensyfikowane przez procesy sorpcji, sedymentacji i asymilacji. Celem pracy jest przedstawienie doświadczeń z wdrażania, funkcjonowania oraz eksploatacji systemów hydrofitowych w województwie pomorskich w latach 1984-2014.
30 years of treatment wetland application in poland- progress and reserch
- Hanna Obarska-Pempkowiak
- Magdalena Gajewska
- Ewa Wojciechowska
- Katarzyna Kołecka
- Arkadiusz Ostojski
2014
The experiences with design and operation of constructed wetlands in the Pommerania region during last 30 years followed by carried out investigations of treatment processes lead to the following conclusions:First applications of constructed wetlands for biological sewage treatment were made in 1984-92. The later implementations of multi-stage constructed wetlands in the individual household and local scale enable wastewater treatment according to the rule of sustainable development, with special impact on natural treatment processes and elimination of by-products. The investigations carried out in the years 2008-10 indicated that constructed wetlands can provide effective removal of toxic pollutants from reject waters from sewage sludge centrifugation and from municipal landfill leachate. The new application of constructed wetlands in Poland is treatment of stormwater runoff and protection of streams in the urbanized area against the inflow of huge loads of pollutants during rain events. The reed beds provide dewatering and stabilization of sewage sludge with the efficiency similar to mechanical devices used in highly effective wastewater treatment plants
3D Computer Model of the Hip Joint Cartilage
- Magdalena Karczewska-Wysocka
2014 International Journal of Computational Bioinformatics and In Silico Modeling
This paper presents 3D computer model of the hip joint cartilage in the ANSYS program. Model is made on the basis of anatomy and collected data on the material constants of bone and cartilage components. Analysis and comparison of biochemical model, viscoelastic and molecular mixed - aggregation serves to facilitate the creation of the next model of reality, which could be used in the design of joint prostheses. The correctness of the model was tested in a series of simulations for three different cases in which distinguished 15 variants of the "stickiness - order". The results for one of them is presented in the form of graphs.
3D Imaging Of Underwater Objects Using Multi-Beam Data
- Marek Kulawiak
- Zbigniew Łubniewski
2014 Pełny tekst HYDROACOUSTICS
One of the main applications of multibeam sonars is high resolution bathymetry measurement, as well as detecting and imaging of underwater objects like shipwrecks. In order to obtain the visualisation quality good enough to allow the researcher to investigate an object in more detail, the approach relying on construction of three-dimensional model of an imaged object, e.g. consisting of nodes, edges and plane elements (facets) is needed. Preceded by the short State-of-the-Art review, the application of selected algorithms for three-dimensional seafloor surface and underwater object shape reconstruction have been presented. Two types of algorithms were investigated in the context of real time application possibility, namely, raster height map as well as 2D Delaunay triangulation. The presented preliminary results are promising both with respect to reconstructed 3D shape quality as well as to algorithm computational complexity allowing for real time mode applications.
3D Machine Vision System for Inspection of Contact Strips in Railway Vehicle Current Collectors
- Leszek Jarzębowicz
- Sławomir Judek
2014
Construction and technical condition of current collectors is crucial to reliability and safety of railway transportation. According to the Technical Specifications for Interoperability railway vehicles in the European Union should be equipped with carbon contact strips. Excessive wear or defects of contact strips degrade the capability of undisturbed power transmission, cause faster wear of contact wire, and can even result in catenary rupture. The technical condition of contact strips is assessed manually during periodical services performed by rolling stock operators. However, rail infrastructure companies are also interested in pantographs inspection of the vehicles running within their network. A novel inspection system for current collectors contact strips is presented. The system uses a specialized camera and a laser line generator to scan the contact strips surface. The scanning is performed on a railway line, when a vehicle passes the inspection point. A prototype of the system was tested in the target conditions and sample scanning results were recorded. Basic algorithms for automatic analysis of contact strips wear were introduced. Accuracy and repeatability of the measurement were assessed. The potential of commercial implementation of the system was confirmed.
A 3D-FEM mesh technique for fast analysis of waveguide problems containing rotatable tuning elements
- Grzegorz Fotyga
- Paweł Bielski
- Krzysztof Nyka
2014
In this paper a meshing technique for 3D Finite Element Method is presented. It allows for fast analysis and optimization of the waveguide structures, which contain rotatable tuning elements. In the proposed procedure a thin layer of varying cylindrical mesh buffer is introduced in order to reuse unchanged mesh and FEM matrices in the rest of the domain.
A calculation proposal of labour time input when concreting in difficult atmospheric conditions
- Beata Grzyl
- Adam Kristowski
2014 Pełny tekst Czasopismo Techniczne
The paper presents a selected proposal of establishing labour input in concreting jobs carried out in difficult atmospheric conditions.
A calibration model for gas sensor array in varying environmental conditions
- Paweł Kalinowski
- Karolina Sturgulewska
- Katarzyna Koc
- Piotr Jasiński
- Grzegorz Jasiński
2014
Abstract: Gas-analyzing systems based on gas sensors, commonly referred to as electronic noses, are the systems which enable the recognition of volatile compounds in their working environment and provide the on-line results of analysis. The most commonly used type of sensors in such systems is semiconductor gas sensors. They are considered to be the most reliable in the long-term applications (more than 1 year), however, their signal tends to drift. Instability of semiconductor gas sensors is one of the most challenging issues to solve in order to get reliable e-nose systems. There are a few causes of drift phenomenon, like i.e. sensors poisoning or aging. On the other hand, drift-like effects are also connected with the influence of environmental parameters such as temperature, humidity or the parameters connected with measurement systems – such as gas flow rate in sensors measurement chamber. In the case of devices for air-quality monitoring, which are exposed to varying environmental conditions it is crucial to develop the robust sensor signals processing system, which is insensitive to the variation of environmental conditions. In this article we present the calibration model for an array of four semiconductor sensors which is able to eliminate the influence of temperature and gas flow rate effect from the sensor responses.
A Canonical Switched Capacitor DC-DC Converter. A look at how the historical SC synthesis problem is getting solved
- Marek Makowski
2014
We reconsider a solution to the historical problem in switched capacitor (SC) DC-DC converter synthesis. Specifically, we retackle the problem of constructing an SC twophase network realizing arbitrary voltage conversion ratio within rational bounds defined. Theoretical foundations are available in our earlier research [3] where a nonconstructive proof of existence was given. We briefly review and comment on known circuit solutions and conclude that they cannot be complete as they lack some general setting in view of the results given in [2] and [3] and versus the consecutive notions of canonical, semicanonical, and subcanonical converters, defined in the current paper. Eventually, and in complementary opposition to [3] we give now alternative constructive proofs by providing circuit examples. Two canonical topologies emerged based on series-parallel and Fibonacci converters.
A compact microstrip rat-race coupler constituted by nonuniform transmission lines
- Adrian Bekasiewicz
- Piotr Kurgan
2014 MICROWAVE AND OPTICAL TECHNOLOGY LETTERS
In this work, a step-by-step development of a compact microstrip rat-race coupler (RRC) has been presented and discussed. A high degree of miniaturization has been obtained by substituting six quarter-wavelength uniform atomic building blocks of a RRC by their nonuniform counterparts. The miniaturization procedure has been realized in three progressive steps: (i) the first layout solution of a miniaturized RRC has been acquired by using an accurate mathematical model of a nonuniform transmission line (NUTL); (ii) the second layout solution has been obtained by a manual refinement and EM fine-tuning of the NUTL geometry aimed at the utilization of the interior of the RRC in a highly efficient manner; (iii) the final layout, occupying only 8.5% estate area in comparison to a conventional RRC, is the result of the EM optimization. The experimental results confirm the theoretical predictions, proving the vital usefulness of the approach.
A compartment model of alveolar–capillary oxygen diffusion with ventilation–perfusion gradient and dynamics of air transport through the respiratory tract
- Jacek Jaworski
- Grzegorz Redlarski
2014 COMPUTERS IN BIOLOGY AND MEDICINE
This paper presents a model of alveolar–capillary oxygen diffusion with dynamics of air transport through the respiratory tract. For this purpose electrical model representing the respiratory tract mechanics and differentia equations representing oxygen membrane diffusion are combined. Relevant thermodynamic relations describing the mass of oxygen transported into the human body are proposed as the connection between these models, as well as the influence of ventilation–perfusion mismatch on the oxygen diffusion. The model is verified based on simulation results of varying exercise intensities and statistical calculations of the results obtained during various clinical trials. The benefit of the approach proposed is its application in simulation-based research aimed to generate quantitative data of normal and pathological conditions. Based on the model presented, taking into account many essential physiological processes and air transport dynamics, comprehensive and combined studies of the respiratory efficiency can be performed. The impact of physical exercise, precise changes in respiratory tract mechanics and alterations in breathing pattern can be analyzed together with the impact of various changes in alveolar–capillary oxygen diffusion. This may be useful in simulation of effects of many severe medical conditions and increased activity level.
A Comprehensive Analysis of Impedance of the Electrochemical Cell
- Paweł Ślepski
- Ewa Janicka
2014 RUSSIAN JOURNAL OF ELECTROCHEMISTRY
A comprehensive impedance characteristics of two electrodes electrochemical cell has been pre sented. In this method a multisinusoidal current excitation signal is used. The change of potential of both the electrodes are all registered as a function of time. The proposed method gives the possibility of determining the impedance of both electrodes individually as well as the impedance of a twoelectrode system. Additional application of short time Fourier transform of time registers allows the determination of changes in the mea sured impedance values over time. In order to present the possibilities of the proposed technology was applied to a process of charging commercially available electrochemical cell NiCd. The new measurement method ology allows understanding the dynamics of processes occurring in a electrochemical cell. This is the basis for the development of effective and affordable electrocatalysts. Thanks to results obtained with Dynamic Elec trochemical Impedance spectroscopy (DEIS) method it is possible to understand the mechanisms and kinet ics of processes occurring in electrochemical cells while charging.
A Concept and Design Optimization of Compact Planar UWB Monopole Antenna
- Adrian Bekasiewicz
- Sławomir Kozieł
2014
A novel structure concept of a compact UWB monopole antenna is introduced together with a low-cost design optimization procedure. Reduced footprint is achieved by introduction of a protruded ground plane for current path increase and a matching transformer to ensure wideband impedance matching. All geometrical parameters of the structure are optimized simultaneously by means of surrogate based optimization involving variable-fidelity EM antenna simulations, which allows us to obtain small antenna size while maintaining low reflection in the UWB frequency range.
A Concept of Mechatronic design for a Surveillance of Dynamic Systems
- Krzysztof Jan Kaliński
- Marek Galewski
- Marek Chodnicki
- Cezary Buchholz
2014
W publikacji przedstawiono zastosowanie koncepcji projektowania mechatronicznego w nadzorowaniu systmów dynamicznych. W szczególności są to aktywne nadzorowanie drgań podczas frezowania oraz nadzorowanie ruchu platformy 3-kołowej. Przy tworzeniu opisywanych rozwiązań zastosowano techniki projektowania wirtualnego, symulacjje komputerowe jaki w technice Hardware-in-the-Loop. W pracy zamieszczono także przykładowe wyniki badań eksperymentalnych w.w. systemów.
A constitutive model for concrete based on continuum theory with non-local softening coupled with eXtended Finite Element Method. Computational Modelling of Concrete Structures,
- Jerzy Bobiński
- Andrzej Tejchman-Konarzewski
2014
Artykuł omawia model połączony ciągły-nieciągły do modelowania stref lokalizacji i rys w betonie niezbrojonym. Obliczenia wykonano stosując rozszerzoną metodę elementów skończonych. Wyniki numeryczne porównano z doświadczeniami.
A detector of sleep disorders for using at home
- Piotr Przystup
- Adam Bujnowski
- Jacek Rumiński
- Jerzy Wtorek
2014 Pełny tekst Journal of Telecommunications and Information Technology
Obstructive sleep apnea usually requires all-ni ght examination in a specialized clinic, under the supervision of a medical staff. Because of those requirements it is an expensive and a non-widely utilized test. Moving the examination procedure to patients’ home with automatic analysis algorithms involved will decrease the costs and make it available for larger group of patients. The developed device allows all-night recordings of the following biosignals: three channels ECG, thoracic impedance (respiration), snoring sound sand larynx vibrations. Additional information, like patient’s body position changes and electrodes’ attachment quality are estimated as well. The reproducible and high quality signals are obtained using the developed and unobtrusive device.
A Dirac delta-type orthogonality relation for the on-the-cut generalized associated Legendre functions of the first kind with imaginary second upper indices
- Radosław Szmytkowski
- Sebastian Bielski
2014 INTEGRAL TRANSFORMS AND SPECIAL FUNCTIONS
The orthogonality relation for the on-the-cut generalized associated Legendre functions of the first kind with imaginary second upper indices is evaluated in a closed form. It is found to be proportional to a sum of two terms, both depending on the second upper indices and containing the Dirac delta distribution.
A first-principles study of electron attachment to the fully hydrated bromonucleobases
- Miłosz Wieczór
- Paweł Wityk
- Jacek Czub
- Lidia Chomicz
- Janusz Rak
2014 CHEMICAL PHYSICS LETTERS
Degradation mechanism of four brominated nucleobases (BrX), potential DNA radiosensitizers, is studied in explicit water solution, using ab initio molecular dynamics. Several fs long dynamics is needed to localize an electron on the nucleobase. Produced by electron attachment BrX anion radical degrades through the bromide anion abstraction, barrier-free (purines) or with low barrier (pyrimidines), to a reactive nucleobase radical. Such differences in dissociative behavior of purines and pyrimidines suggest that brominated purine anions should dissociate more effectively than their pyrimidine counterparts.
A fuzzy logic model for forecasting exchange rates
- Tomasz Korol
2014 KNOWLEDGE-BASED SYSTEMS
This article is devoted to the issue of forecasting exchange rates. The objective of the conducted research is to develop a predictive model with the use of an innovative methodology - fuzzy logic theory - and to evaluate its effectiveness in times of prosperity and during the financial crisis. The model is based on sets of rules written by the author in the form of IF-THEN, where expert knowledge is stored. This model is the result of ten years of the author's research on this issue. Empirically, this paper employs three currency pairs as experimental datasets: JPY/USD, GBP/USD and CHF/USD. From the model verification, it is demontrasted that refined processes are effective in improving the forecasting of exchange rate movements.