Repozytorium publikacji - Politechnika Gdańska

Ustawienia strony

english
Repozytorium publikacji
Politechniki Gdańskiej

Pokaż publikacje z roku

Publikacje z roku 2012

Pokaż wszystkie
  • Entropy measures of heart rate variability for short ECG datasets in patients with congestive heart failure
    • Beata Graff
    • Grzegorz Graff
    • Agnieszka Kaczkowska
    2012 Acta Physica Polonica B Proceedings Supplement

    We investigated the usefulness of entropy measures calculated for short ECG series in distinguishing healthy subjects from patients with congestive heart failure (CHF). Four entropy measures were tested: Approximate Entropy (ApEn), Sample Entropy (SampEn), Fuzzy Entropy (FuzzyEn) and Permutation Entropy (PE), each computed for ECG series of 1000, 500, 250 and 100 RR intervals. We found that with a reduction of the data set length up to 250 RR intervals, values of ApEn, SampEn, FuzzyEn and PE can remain significantly different in patients with CHF compared to healthy individuals. SampEn and FuzzyEn differentiated considered groups even for data sets of 100 RR intervals.

  • Entropy Measures of heart rate variability for short ECG datasets in patients with congestive heart failure
    • Beata Graff
    • Agnieszka Kaczkowska
    • Grzegorz Graff
    2012 Pełny tekst Acta Physica Polonica B Proceedings Supplement

    We investigated the usefulness of entropy measures calculated for short ECG series in distinguishing healthy subjects from patients with congestive heart failure (CHF). Four entropy measures were tested: Approximate Entropy (ApEn), Sample Entropy (SampEn), Fuzzy Entropy (Fuzzy En) and Permutation Entropy (PE), each computed for ECG series of 1000, 500, 250 and 100 RR intervals. We found that with a reduction of the data set length up to 250 RR intervals, values of ApEn, SampEn, Fuzzy En and PE can remain significantly different in patients with CHF compared to healthy individuals. SampEn and Fuzzy En differentiated considered groups even for data sets of 100 RR intervals.

  • Environmental consequences of emulsifying properties of biosurfactant produced by Pseudomonas sp.
    • Ilona Edyta Kłosowska-Chomiczewska
    • Elżbieta Hallmann
    • Krystyna Mędrzycka
    • Elena Karpenko
    2012

    Biosurfactants are natural surfactants produced by variety of microorganisms. They are very prospective product due to good biodegradability, low toxicity, good physicochemical properties and high efficiency in many applications. Moreover, they are efficient in wide range of pH, temperatures and salinity. Thus, they have potential to be used in many applications. However, their later presence in municipal and industrial wastewater can pose many problems due to emulsification. Thus, the emulsifying properties of crude biosurfactant produced by Pseudomonas sp. and its single species were investigated. Paraffin and rapeseed oils were used as oil phase.

  • Environmental Degradation of Engineering Materials & Materials Engineering and Technologies
    • Jerzy Łabanowski
    • Andrzej Zieliński
    2012 Solid State Phenomena

  • Environmental degradation of titanium alloy in artificial saliva
    • Andrzej Zieliński
    • Łukasz Zborowski - Weychman
    2012 Pełny tekst Advances in Materials Science

    The titanium and its alloys are potentially prone to hydrogen embrittlement, including those proposed for dental implants. The research has been aimed to assess a susceptibility to environment-enhanced degradation of the Ti-13Zr-13Nb alloy in artificial saliva with or without hydrofluoric acid, subject or not to cathodic polarisation. The results have shown that even if artificial saliva is safe environment, both cathodic polarization and cathodic current result in brittle cracking. Either hydride-related embrittlement or fluoride-related stress corrosion cracking are considered as potential sources.

  • Environmental fate of BTEX compounds in ambient air
    • Marta Słomińska
    • Piotr Konieczka
    • Jacek Namieśnik
    2012 CRITICAL REVIEWS IN ENVIRONMENTAL SCIENCE AND TECHNOLOGY

    As a result of the industrialization and urbanization in the world, human pressure on the environment is intensifying, leading to detrimental changes in both biotic and abiotic compartments. One of the many consequences of this state of affairs is the increasing rate of emission into the atmosphere of volatile organic compounds, including the so-called BTEX (benzene, ethylbenzene, toluene, xylenes) compounds. The article reviews the main sources of BTEX compounds in ambient air and the impact on the photochemistry and individual elements of the environment (water, air , soil, living organisms). Potential transport mechanisms, which include: transpiration, distribution, bioaccumulation, biodegradation, etc. are described. The paper presents the characteristic mechanisms of radical reactions and gives a view on environmental fate of BTEX compounds in the atmosphere. The article comprises the concentration of BTEX compounds both in rural and industrial areas of different parts of world, showing the scale of existing emissions of BTEX compounds to the atmosphere.

  • Environmental Risk Assessment of WWII Shipwreck pollution
    • Justyna Rogowska
    • Jacek Namieśnik
    2012

    The pollution of the sea is a global problem that has arisen as a consequence of the industrialization of the world and the intense transportation of crude oil and the products of its refinement. As sailing vessels were replaced by motor propelled ships towards the end of the 19th century, a new source of sea water pollution came into being. Every emergency involving a tanker carrying crude oil and its products is a potential source of pollution, not only of the sea water but also of shorelines. An important though little understood problem is the seepage of bunker fuel or cargoes from sunken ships, many of which went to the bottom as a result of hostilities at sea during the two World Wars. Among these wrecks are vessels that still contain fuel or other dangerous substances in their tanks/holds. After 60 years at the bottom of the sea, most of these wrecks will have begun to corrode, so it is clear that before long petroleum products are likely to seep from them into the surrounding water. The seepage of petroleum products from wrecks like the USS Mississinewa or the s/s Skytteren have made it clear that detailed studies must be carried out to assess the risk of seepage, or if this has already taken place, to evaluate its effects on the marine environment. In this context, a series of questions has arisen about how to proceed with wrecks that are a potential threat to the environment. The objectives, principles and methods of investigating the effect on marine ecosystems of wrecks need to be defined and the probable hazard they present assessed. Such assessments provide crucial information upon which decisions are based regarding the procedures for dealing with wrecks and for minimizing the environmental hazards they pose. In addition, a thorough assessment of the state of a wreck will help to reduce the costs and duration of operations to remove fuel from it and will improve the chances of their success.

  • Environmental Role of Rime Chemistry at Selected Mountain Sites in Poland
    • Michał Godek
    • Marek Błaś
    • Mieczysław Sobik
    • Żaneta Polkowska
    • Katarzyna Cichała-Kamrowska
    • Jacek Namieśnik
    2012 PURE AND APPLIED GEOPHYSICS

    The results of field experiments on fog pollutantdeposition enhanced by local mountain climate, completed by thedendrochronological analysis of the forest response, are presentedin this paper. In spite of their low absolute altitude (1,000-1,600 ma.s.l), the Sudetes and the Silesian Beskid form a noticeable orographicbarrier for the airflow of the humid Atlantic air masses.This results in the increase of cloudiness and fog frequency as wellas both atmospheric precipitation and horizontal precipitationvolume. Between January and December 2009 the daily samples ofatmospheric precipitation and rime were collected on three selectedmountain tops of similar height. The selected measurement siteswere situated along a 300 km WNW-ESE profile parallel to thedirection of the prevailing atmospheric circulation. High day-todayvariability of rime water volume, the total ionic content andchemical composition of the individual samples were typical ofeach measurement site and depended on the emission patterns,synoptic situation and the local climatic conditions influencedchiefly by terrain relief. Significantly larger rime efficiency andpollution deposition via fog were observed at the westernmostSzrenica Mt site rather than more to the southeast at S ´ nie_znik Mtand Skrzyczne Mt. This difference should be explained by moreintense orographic deformation of predominant airflow from thewestern sector as well as the higher liquid water content of fog inthe vicinity of Szrenica. Both temporal and spatial variability of fogdeposition correlates closely with the health status of the drilledtrees of Norway Spruce (Picea Abies) in the S ´ nie_znik Massif. Theaveraged annual tree rings width near the local tree line (1,350 ma.s.l.) on the summit dome of S ´ nie_znik decreased by 71% between1950 and the early 1980s. This is also the area of the highest rate ofatmospheric pollutant deposition due to particularly important roleof fog. At an altitude of 1,200 m a.s.l. The relevant changes of ringwidth were different depending on slope aspect: 60% on westernslopes well exposed for orographic fog formation and 42% oneastern slopes where fog deposition is less intense. The results ofthe dendrochronological analysis provide the evidence for theupward trend of tree rings width since 1981-1984 break through upto date, which should be attributed to the progressive reduction ofpollutant emission in Central Europe.

  • Enzymatic cross-linking of β-lactoglobulin in solution and at air–water interface: Structural constraints
    • Dilek Ercili-Cura
    • Riitta Partanen
    • Fiona Husband
    • Mike Ridout
    • Adam Macierzanka
    • Martina Lille
    • Harry Boer
    • Raija Lantto
    • Johanna Buchert
    • Alan Mackie
    2012 FOOD HYDROCOLLOIDS

    Effective and controlled use of cross-linking enzymes in structure engineering of food systems depends on characterization of the favorable conditions for enzyme-substrate complex and the limiting factors for the desired modification. In this respect, we analyzed the susceptibility of bovine β-lactoglobulin (BLG) to enzymatic cross-linking by Trichoderma reesei tyrosinase (TrTyr) and transglutaminase (TG). Changes in BLG molecular structure were determined at pH 6.8, 7.5 and 9.0 before and after high-temperature heat treatment. The conformational change was linked to efficiency of protein cross-linking. BLG was not susceptible to TrTyr without heat treatment. TG, however, induced inter-molecular cross-links at pH 7.5 and 9.0. After the heat treatments, BLG molecules adopted a molten-globule-like conformation. Both of the enzymes were able to form inter-molecular cross-links between heat-denatured BLG molecules. Electrophoretic mobility and broadness of the oligomer bands created by both enzymes on SDS-PAGE gels showed differences which were linked to the availability and number of target amino acid residues. Evidence for intra-molecular cross-linking was obtained. Once adsorbed to air/water interface, BLG formed a viscoelastic surface film which was characterized by surface shear rheology. Application of cross-linking enzymes under a dense layer of BLG molecules at the interface led to decreasing G′ with time. Intra-molecular links were most probably favored against inter-molecular on packed BLG layer leading to constrained molecules. Results in general emphasize the importance of structural and colloidal aspects of protein molecules in controlling inter/intra-molecular bond formation by cross-linking enzymes.

  • Enzyme immobilization on magnetic nanoparticles
    • Anna Panek
    • Olga Pietrow-Tobiszewska
    • Józef Synowiecki
    2012 New Biotechnology

    Immobilized enzymes have been commonly used in many branches of industry, biotechnology, medicine and also in analytical chemistry. Their use provides many advantages in comparison with free enzymes including repeated, easy recovery of the enzyme and improvement in enzyme stability. Enzymes are strong and specific catalysts, but are also expensive and fragile. Their immobilization and stabilization may reduce reaction costs, which are especially beneficial for industrial applications.

  • Epigenetic regulation and regeneration: the search for differentially methylated genes in the MRL mouse
    • Justyna Podolak-Popinigis
    • Bartosz Górnikiewicz
    • Anna Ronowicz
    • Piotr Madanecki
    • Paweł Sachadyn
    2012 Acta Biochimica Polonica

    The MRL mouse is an inbred laboratory strain, which was developed in the 60’s of the 20th century and has been extensively used as a model of lupus erythematosus. The regenerative abilities of the strain were discovered in the 90' when the MRL mouse was shown to close 2 mm hole punches made in the ear pinnae four weeks after injury without scarring. The phenomenon has not been observed in other mouse strains, where the holes remain for life. The process is accompanied by cartilage regrowth, normal vascularisation, the restoration of hair follicles and peripheral nerves. Enhanced regenerative response in the MRL mouse has been observed in heart after cryo-injury of the right ventricle, spinal cord following hemi-section, digits after amputation, and articular cartilage. A remarkable feature of the strain is that the MRL mice retain several foetal biochemical characteristics as adults, including increased expression of stem cell markers. The epigenetic regulation, though known to play a key role in the organ development, has not been examined with respect to regeneration. The idea of our project is to examine the epigenetic basis of regeneration by comparing genome-wide DNA methylation and expression profiles in two murine strains: the MRL mouse which displays enhanced regeneration abilities and the control C57BL/6J mouse. In our experiments we applied methylated DNA immunoprecipitation followed by the analysis using NimbleGen microarray platform (Roche) which covers all promoter regions in the murine genome. We examined the promoter methylation profiles in heart, liver and spleen samples. The preliminary results allowed us to extract a number of genes that show the most spectacular differences in the DNA methylation of promoter regions between the MRL and the control strain (i.e. 100% methylated and 100% unmethylated). Our particular interest is focused on these among the differentially methylated genes which display similar methylation pattern in the MRL mouse and murine embryonic stem cells. The microarray data are being verified by quantitative Real-Time PCR. We believe that the elucidation of the epigenetic basis of regeneration phenomenon in the MRL mouse will contribute to a better understanding of regeneration processes, as well as it may provide clues on how cross the limitations of regeneration in mammals.

  • Equivalence of on-line and reference methods for measurement of pm10 = Równoważność metod pomiarowych on-line i odniesienia stosowanych do oznaczania pm10
    • Jacek Gębicki
    • Krystyna Szymańska
    2012

    W badaniach nad równoważnością wyników otrzymanych za pomocą pomiaru ciągłego PM10 w stosunku do metody odniesienia stosuje się nienormatywny przewodnik unijny "Demonstration of Equivalence of Ambient Air Monitoring Methods. EC Working Group on Guidance for the Demonstration of Equivalence". W pracy omówiono sposób postępowania wg tego przewodnika. Na podstawie testu terenowego przeprowadzonego na terenie Gdańska w latach 2010-2011 określono czy wyniki pomiaru ciągłego są/nie są równoważne wynikom uzyskanym za pomocą metody odniesienia.

  • Equivariant degree of convex-valued applied to set-valued BVP
    • Zdzisław Dzedzej
    2012 Pełny tekst Central European Journal of Mathematics

    W pracy określono stopień ekwiwariantny dla odwzorowań o wartościach zwartych i wypukłych. Zastosowano go do dowodu twierdzenia o istnieniu wielunietrywialnych rozwiązań problemu brzegowego typu Dirichleta dla inkluzji różniczkowych z warunkami wzrostu typu Bernsteina-Nagumo, z dodatkowymi symetriami

  • Equivariant Morse equation
    • Marcin Styborski
    2012 Pełny tekst Central European Journal of Mathematics

    The paper is concerned with the Morse equation for flows in a representation of a compact Lie group. As a consequence of this equation we give a relationship between the equivariant Conley index of an isolated invariant set of the flow given by x˙ = − ∇f(x) and the gradient equivariant degree of ∇f. Some multiplicity results are also presented.

  • Estimating the Impact of Globalization on International Competitiveneess : a Multidimensional Approach
    • Hanna Adamkiewicz
    2012 Pełny tekst China-USA Business Review

    This paper examines the effects of globalization on international competitiveness (IC). The aggregated and disaggregated indices of IC (World Economic Forum) and globalization (KOF) for 132 countries in 2008 are used for the estimation of regression functions. The results show that globalization positively influences IC at the highest aggregation levels of the indices used. Social and political globalization affect IC at intermediate aggregation levels, whereas, economic globalization has no impact on IC. A the lowest aggregation levels, personal contacts, cultural proximity, and political globalization are the primary, factors affecting IC's pillars, although the impact of economic restrictions on some of the IC pillars is also observed.

  • Estimation of Stresses in a Dry Sand Layer Tested on Shaking Table
    • Andrzej Sawicki
    • Marek Kulczykowski
    • Robert Jankowski
    2012 Pełny tekst Archives of Hydro-Engineering and Environmental Mechanics

    Theoretical analysis of shaking table experiments, simulating earthquake response of a dry sand layer, is presented. The aim of such experiments is to study seismic-induced compaction of soil and resulting settlements. In order to determine the soil compaction, the cyclic stresses and strains should be calculated first. These stresses are caused by the cyclic horizontal acceleration at the base of soil layer, so it is important to determine the stress field as function of the base acceleration. It is particularly important for a proper interpretation of shaking table tests, where the base acceleration is controlled but the stresses are hard to measure, and they can only be deduced. Preliminary experiments have shown that small accelerations do not lead to essential settlements, whilst large accelerations cause some phenomena typical for limit states, including a visible appearance of slip lines. All these problems should be well understood for rational planning of experiments. The analysis of these problems is presented in this paper. First, some heuristic considerations about the dynamics of experimental system are presented. Then, the analysis of boundary conditions, expressed as resultants of respective stresses is shown. A particular form of boundary conditions has been chosen, which satisfies the macroscopic boundary conditions and the equilibrium equations. Then, some considerations are presented in order to obtain statically admissible stress field, which does not exceed the Coulomb-Mohr yield conditions. Such an approach leads to determination of the limit base accelerations, which do not cause the plastic state in soil. It was shown that larger accelerations lead to increase of the lateral stresses, and the respective method, which may replace complex plasticity analyses, is proposed. It is shown that it is the lateral stress coefficient K0 that controls the statically admissible stress field during the shaking table experiments.

  • Estimation of the minimal number of periodic points for smooth self-maps of odd dimensional real projective spaces
    • Grzegorz Graff
    • Jerzy Jezierski
    2012 Pełny tekst TOPOLOGY AND ITS APPLICATIONS

    Let f be a smooth self-map of a closed connected manifold of dimension m⩾3. The authors introduced in [G. Graff, J. Jezierski, Minimizing the number of periodic points for smooth maps. Non-simply connected case, Topology Appl. 158 (3) (2011) 276-290] the topological invariant NJD_r[f], where r is a fixed natural number, which is equal to the minimal number of r-periodic points in the smooth homotopy class of f. In this paper smooth self-maps of real projective space RP^m, where m>3 is odd, are considered and the estimations from below and above for NJD_r[f] are given

  • Estimation of the steam condensation flow via CFD methods
    • Witold Zakrzewski
    • Michał Karcz
    • Sebastian Kornet
    2012 Transactions of the Institute of Fluid-Flow Machinery

    The results of numerical simulations to predict the performance of different steam models have been presented. All of the considered models of steam condensation have been validated on the base of benchmark experiment employing expansion in nozzle and next on the low pressure part of the steam turbine stage. For numerical analysis three models have been finally used – the ideal steam model without condensation, an equilibrium steam model and a nonequilibrium steam model. It was confirmed that only the inclusion of the nonequilibrium effects in the computations can lead to a proper prediction of the condensation phenomena in the test nozzle. However the basic characteristics of the low-pressure turbine can be succesfully estimated using simple ideal steam or the equilibrium condensation model.

  • Estimation of wear of electroplated tools used for surface grinding
    • Mariusz Deja
    2012

    W pracy dokonano ilościowej oceny zużycia narzędzi galwanicznych diamentowych i borazonowych. Wykorzystano analizę jasności obrazów narzędzi oraz badano liczność ziaren ściernych na czynnej powierzchni narzędzia.

  • Etyka - o konieczności dyskursu etycznego w organizacjach
    • Ewa Hope
    2012 Ekonomika i Organizacja Przedsiębiorstwa

    Do budowania zasad dobrego funkcjonowania organizacji, do odkrywania mechanizmów jej funkcjonowania, analizowania ludzkich potrzeb i możliwości ich realizowania, do wpływu warunków ekonomicznych i kulturowych na sposób funkcjonowania organizacji – do tych problemów przywiązuje się wielką wagę w naukach o zarządzaniu. Czy równie dużą wagę przykłada się – i docenia – rangę zachowań ludzkich w sferze moralnej, wpływ zasad etycznych na funkcjonowanie organizacji, sposób i treści kształcenia przyszłych menedżerów? Poniższy artykuł postuluje nie tylko konieczność dyskursu etycznego w zarządzaniu, ale pokazując rosnącą rolę zasad etycznych w zarządzaniu przedsiębiorstwem ze względu na pojawiające się nowe zjawiska w sferze rynkowej, postuluje uwzględnianie treści etycznych w procesie kształcenia kadr menedżerskich – nie jako osobnego przedmiotu, lecz jako integralnych treści wszystkich wykładanych przedmiotów na uczelni.