04 (1998) Scientific papers, Series A
Permanentní URI k tomuto záznamuhttps://hdl.handle.net/10195/38114
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Článek Otevřený přístup peer-reviewedpublished Interaction of bentonite with dodecyl-benzyl-dimethylammonium bromide and N-[1-(ethoxycarbonyl)pentadecyl] trimethylammonium bromide(Univerzita Pardubice, 1999) Kalousová, JaroslavaInteraction of bentonites with tetrasubstituted ammonium cations of surface-active compounds were studied both by classic heating and in microwave field. The intercalation of the layered silicate which is contained in the bentonite proceeds as an ion exchange, and the interlayer distance increases during this process. Products of the reactions were characterized by gravimetry, DTA, DTG, IR, and X-ray diffraction.Článek Otevřený přístup peer-reviewedpublished Corporate bonds as a source of funds(Univerzita Pardubice, 1999) Tetřevová, LiběnaThe topic of this article is the corporate bonds as a source of funds. The corporate bonds represent external long-term source of funds. The corporate bonds become more and more significant and create a part of long-term debt intruments. This growth is related to rapid business expansion and inadequate funds generated from the internal operations of business firms.Článek Otevřený přístup peer-reviewedpublished The Effect of beating degree on physical characteristics of wood pulp fibres(Univerzita Pardubice, 1999) Potůček, František; Marhanová, MilenaThe purpose of our investigation was to study the influence of the degree of beating on the physical characteristics of unbleached and bleached kraft pulp fibres. For various degrees of beating, the specific volume as well as specific surface basedon on both volume and mass of fibres were determined. To characterize pulp fibres at different degrees of beating, the weighted and arithmetic average lengths of fibres were measured.Článek Otevřený přístup peer-reviewedpublished Contribution to sampling procedure of gold-bearing geological materials(Univerzita Pardubice, 1999) Dempír, JosefIf the gold particles in material to be analyzed are distributed homogeneously and follow the Poisson law, the sample weight necessary for analytical work can be easily estimated using the sampling constant according to Ingamells. With gold particles distributed heterogeneously, Visman's equation are used for the same purpose. In the present paper both approaches are described and their practical use is shown on two gold-bearing ores, one with homogeneously and the other with heterogeneously distributed gold particles.Článek Otevřený přístup peer-reviewedpublished Factors affecting gross-flow microfiltration of dispersions(Univerzita Pardubice, 1999) Mikulášek, PetrThis paper deals with the use of microfiltration in fouling dispersion and discusses the means available to the process designer to minimize the effects of fouling and take them into account when performing the design. The results of recent work which show how the characteristic parameters of membrane (pure water flux and pore size distribution), the effects of operating parameters (composition of dispersion, cross-flow velocity, transmembrane pressure), and the feed flow management (hydrodynamic) methods to improving the flux (the crossflow system in the presence of a fluidized bed and the rotating membrane system) can contribute to the minimisation of fouling and process optimalization.Článek Otevřený přístup peer-reviewedpublished Kinetics and mechanism of crystallization of borophosphate glasses of the ZnO-B2O3-P2O5 system(Univerzita Pardubice, 1999) Mošner, Petr; Koudelka, LadislavBorophosphate glasses of the ZnO-B2O3-P2O5 system were prepared by cooling the melt from 1230 °C. Their crystallization was studied by DSC and X-ray diffraction. The crystallization takes place mostly at 600-800 °C giving at least two crystalline phases with BPO4 as one of the products. The kinetics of the crystallization of borophosphate glass 58.3ZnO-8.3B2O3-33.4P2O5 can be describede be the Šesták-Berggren model, while that of 50ZnO-50B2O3 is better described by the Johnson-Mehl Avrami model. The analysis of the shape and position of the crystallization peak for different sizes of glass powders lead to the conclusion that surface crystallization prevails for the borophosphate glass, While for the borate glass surface crystallization dominates only when the particle size is under 300 um, but internal crystallization prevails in the bulk glass.Článek Otevřený přístup peer-reviewedpublished Segmentation of chemical product market(Univerzita Pardubice, 1999) Lošťáková, HanaThe paper deals with the process of segmentation of market of chemical products. It shows the partial phases of divided segmentation process with the key problem of the whole process of market segmentation-a choice of segmentation variables. The research carried out in chemical companies has shown that it is necessary to use several segmentation variables for segmentation of market of chemical products. The suitable segmentation variables for chemical product devoted to production consumption are given in this paper.Článek Otevřený přístup peer-reviewedpublished Projects of information system for environmental management in Synthesia Pardubice(Univerzita Pardubice, 1999) Hyršlová, Jaroslava; Obršálová, IlonaThe growing importance of environmental management is reflected in a number of important regulations and standards. The aim of these standards and regulations is to harmonize environmental management. All standards emphasize the need of controlling tools for environmental management as well as the need of environmental information system - environmental accounting - as one important part of corporate environmental management. One part of environmental accounting is the identification of environmental costs. Tracking and tracing of environmental costs is a precondition for correct allocation to cost carriers (products) and cost centers. This article deals with the projects of tracking and tracing of environmental costs of the plants incorporated into tha chemical company Synthesia Pardubice.Článek Otevřený přístup peer-reviewedpublished Das Vermengen der Rohstoffe zur Pigmentenherstellung in einem Mischer mit Stochastischer Behälterbewegung(Univerzita Pardubice, 1999) Kuchler, Milan; Kaspar, TomášThe paper deals with effects of time ans intensity of mixing in preparation of threecomponent pigment mixtures. The experiments were carried out in a mixer with stochastic movement of vessel and evaluated by indirect colourimetric method. Economic aspects of the process were investigated too. The results obtained enable finding the optimum combination of time and intensity of mixing for preparation of mixtures of required degree of blending. From economic point of view, the highest-intensity mixing process proved to be the best with the "dyna-Mischer" apparatus.Článek Otevřený přístup peer-reviewedpublished Preparation and characterization of (Bi1-xSbx)2Se3 single crystals(Univerzita Pardubice, 1999) Drašar, Čestmír; Lošťák, PetrThis review paper summarizes papers dealing with characterization of (Bi1-xSbx)2Se3 single crystals which have been produced at the Faculty of Chemical Technology, University of Pardubice. The single crystals of (Bi1-xSbx)2Se3, prepared by a modified Bridgman method, were characterized by means of the X-ray diffraction analysis, homogeneity assessment, and by measurements of the reflectance in the plasma resonance range, transmittance, electric conductivity , Hall constant RH(B//c), Seebeck coefficient alfa(T c) and by figure of merit Z. The model of point defects in single crystals (Bi1-xSbx)2Se3 is used for qualitetive explanation of the changes in physical properties induced by incorporation of Sb atoms into Bi2Se3.