Digitální knihovnaUPCE
 

10 (2004) Scientific papers, Series A

Permanentní URI k tomuto záznamuhttps://hdl.handle.net/10195/38120

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200529

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Nyní se zobrazuje 1 - 10 z 29
  • Náhled
    ČlánekOtevřený přístuppeer-reviewedpublished
    Integrated pollution prevention and control and enterprises in the chemical industry
    (Univerzita Pardubice, 2005) Špaček, Ladislav; Hyršlová, Jaroslava
    Enterprises are becoming increasingly active in their approach to protection of the environment. In the 80's and 90's of the 20th century, the strategy of prevention became increasingly important in Europe. These trends were reflected in the European Commission mainly through the Directive on Integrated Pollution Prevention Union countries since 1999. This paper is concerned with the integrated prevention process in the Czech Republic (CR). It concentrates mainly on the progress of this process in enterprises in the chemical industry and generalizes this information.
  • Náhled
    ČlánekOtevřený přístuppeer-reviewedpublished
    Cholesteric fingersa review
    (Univerzita Pardubice, 2005) Pirkl, Slavomír; Oswald, Patrick
    The behaviour of a cholesteric liquid crystal subjected to a topological frustration together with an a.c. electric field is described. The frustration comes from the homeotropic anchoring of the molecules on the two electrodes limiting the sample. This geometrical boundary condition is incompatible with the helical structure of the phase. As a result, the helix can partly unwind to form "cholesteric fingers" (CF) of different types in coexistence with the homeotropic nematic phase.We review their static and dynamic properties in electric field.
  • Náhled
    ČlánekOtevřený přístuppeer-reviewedpublished
    Study of new colour pigments based on Bi2O3
    (Univerzita Pardubice, 2005) Šulcová, Petra; Jurčíková, Dagmar
    In this work we have studied the colour properties of the Bi2O3 -Ln2O3 system. By solid state reaction we have prepared the mixed oxides (Bi2O3)1-x(Ln2O3)x, where Ln=Er and Ho, with nominal compositions x=0.1, 0.3 and 0.5, and at calcination temperature 800 °C. The structure of prepared compounds was studied by X-ray diffraction analysis. The obtained orange oxide pigments present f.c.c. flurite-type structure. The colour properties measured in the visible region of light (400-700 nm) indicate that the pigments can be expected as new ecological inorganic pigments.
  • Náhled
    ČlánekOtevřený přístuppeer-reviewedpublished
    Influence of ionic strenght and pH of dispersed feeds on microfiltration
    (Univerzita Pardubice, 2005) Šmídová, Dagmar; Mikulášek, Petr; Kőrösová, Mária; Wakeman, Richard J.
    The fluences of particle shape, -potencial and size with change of pH and ionic strenght on permeate flux during the microiltration o model dispersions (two different china clays with mean particle sizes 3.5 m and 1.5 um) on flat sheet ceramic membranes (ZrO2, mean size o pores 0.2 mm) have been studied. The experimental filtration system and the dispersion characterisation experiments are presented. The results of the experiments show that -potential of the particleshas considerable impact on the magnitude of the cake resistance and hence on the permeate flux. The effects are especially pronounced during the microfiltration of dispersion in the area close to isoelectric point of dispersion, where the dispersionhas tendency to instability and the particles tend to aggregate. The effects resulted in higher porosity filter cakes (deposits) and a lower value of filter cake resistance, and hence to a permeate flux that increased to double the value of a non-treated dispersion. These observations are caused the particle interactions.
  • Náhled
    ČlánekOtevřený přístuppeer-reviewedpublished
    A Study on simultaneous determination of indium and cadmium at mercury based- and bismuth film-plated electrodes
    (Univerzita Pardubice, 2005) Tesařová, Eva; Bobrowski, Andrzej; Królicka, Agnieszka; Švancara, Ivan; Vytřas, Karel
    Linear sweep anodic stripping voltammetry (LSASV) and differential pulse anodic stripping voltammetry (DPASV) have been used for the simultaneous determination of In and Cd in hydrochloric acid-based media at the hanging mercury drop electrode (HMDE), mercury-, and bismuth-plated glassy carbon electrode (MF-GCE and BiF-GCE, respectively). The main focus of the study was concentrated on the resolution of In- and Cd-signals achieved by means of the three investigated working electrodes. Whereas the LSASV as well as DPASV signals for indium and cadmium almost overlapped when using the HMDE, the corresponding In- and Cd-peaks were well-separated at both MF-GCE and BiF-GCE. In addition, at the latter film electrode, a typical resolution as well as the sensitivity of the respective stripping signals were even superior to those evaluated for the MFE. Based on the results obtained, the possibilities and limitations of the individual elctrodes are outlined with particular emphasis on the bismuth film-plated electrode substrate.
  • Náhled
    ČlánekOtevřený přístuppeer-reviewedpublished
    Optimization of a new chemiluminescence sensor based on peroxyoxalate chemiluminescence
    (Univerzita Pardubice, 2005) Omanović, Enisa; Moderegger, Helmut; Kalcher, Kurt
    The optimization of the experimental conditions for using new single-shot sensors based on chemiluminescence (CL) with two oxalate esters is presented. The new sensors are suitable for the determination of hydrogen peroxide in different kinds of samples. Each sensor contains an oxalic acid ester, a fluorescer, and a polymer. Bis (2,4-dinitrophenyl) oxalate (DNPO) and bis (2, 4, 6-trichlorophenyl) oxalate (TCPO) are used as esters in chemiluminescent reagents. The fluorescer and the polymer in both systems was 9, 10-diphenylanthracene and cellulose acetate. The polymeric membrane on a transparent glass support contained reactants and was placed over a photocell as detector, the sample was directly applied onto the membrane. The composition of the membrane was optimized. The sensors will be tested on samples of commercially available washing powders.
  • Náhled
    ČlánekOtevřený přístuppeer-reviewedpublished
    Correct ways of using regression for method comparison studies - determination of LDL-cholesterol
    (Univerzita Pardubice, 2005) Islamčević, Maša; Mocak, Jan; Brodnjak-Vončina, Darinka; Blažíček, Pavol
    Statistical comparison of two laboratory methods, measuring the same objects, is usually performed by regression. However, the results achieved are often incorrect due to application of ordinary least squares linear regression, which should not be used for this purpose. A statistically correct decision whether two laboratory methods provide concordant or discordant results is reliable only when using regression techniques which respect the errors of both compared variables.Another correct possibility is to apply a robust regression where the errors of compared variables are not influencing the calculation of regression parametersand their standard deviations. A survey of appropriate regression techniques and their use for comparison of real-life clinical methods is given in this paper.
  • Náhled
    ČlánekOtevřený přístuppeer-reviewedpublished
    Application of carbon fiber microelectrodes in electrochemical investigations
    (Univerzita Pardubice, 2005) Posavec, D.; Petrović, Ž.; Metikoš-Huković, M.
    In this work, the electrocrystallization of nickel from Ni2+ -acidic bath has been investigated using an assembly of carbon fiber microelectrodes, consisting of single and multi microdics randomly distributed inside the matrix of a non-conducting polymer. The microdiscs were far enough apart that the crystals could not interact, thus limiting the total observed current density to a linear superposition of the current densities from each crystal considered independently. The current-time transient response was quantitatively evaluated using the Scharifker and Hills' nucleation model. The high rate of nucleation after a rapid increase in the overpotential was discussed in relation to the physical model for three-dimensional (3D) nucleation with diffusion-controlled growth. Excellent agreement between the experimental results and the theoretical curve for 3D progressive nucleation was obtained.
  • Náhled
    ČlánekOtevřený přístuppeer-reviewedpublished
    Determination of dioxins in dyes and pigments with HRGC/HRMS
    (Univerzita Pardubice, 2005) Križanec, B.; Brodnjak-Vončina, Darinka; Vončina, E.; Le Marechal, A. Majcen
    Dioxins in some textile dyes and pigments may be a significant source of both human exposure and environmental contamination. Dyes and pigments contaminated with dioxins are the main sources of dioxins in textile industry. Further formations of dioxins can occur via dyeing and textile finishing processes at the conditions favoured for the generation of PCDD/Fs (high temperatures, alkaline conditions, UV radiation or other radical starters). Distribution of dioxins and their fate during textile processes were investigated. Textile disperse dye contaminated with dioxins was used in dyeing process and increasing of dioxins content during the process was observed.
  • Náhled
    ČlánekOtevřený přístuppeer-reviewedpublished
    Synthesis of Co-Zn-Al-Ti-Cr spinel pigment
    (Univerzita Pardubice, 2005) Mesíková, Žaneta; Trojan, Miroslav; Šulcová, Petra
    A synthesis of the green spinel pigment Co3.7Zn4.3Al2.9TiCr11.7Ox by a new method of preparation has been investigated. All the samples of pigment were prepared by a two-step method of preparation. The influences of the raw material on the colour properties of the pigments were monitored. An STA Jupiter 449 apparatus (NETZSCH GmbH, Germany) was used for determination of the second step of the preparation. The colour of the pigments was measured in the visible region of light (400-700 nm) with a MiniScan (Hunter Lab, USA). The structures of prepared samples of pigment were studied by X-ray powder diffraction using D8 Advance equipment (Bruker, AXS, UK). The grain size distribution, specific weight, oil number and CPVC of the prepared samples were determined too.