National Repository of Grey Literature 96 records found  beginprevious87 - 96  jump to record: Search took 0.00 seconds. 
On the Mechanism of Electrochemical Reduction of Dodecylpyridinium Bromide in Aprotic Media. An Impedance Study
Hromadová, Magdaléna ; Kolivoška, Viliam ; Pospíšil, Lubomír
Reduction mechanism of n-dodecylpyridinium bromide (DPBr) in dimethylsulfoxide has been studied. Based on the classical polarographis methods as well as on the use of AC voltammetry and impendance spectroscopy techniques it was shown that DPBr is reduced in a reversible one electron transfer step followed by the dimerization of the corresponding radical species.
Electrochemistry of selected radiosenzitizer-etanidazole
Gál, Miroslav ; Híveš, J. ; Sokolová, Romana ; Hromadová, Magdaléna ; Kocábová, Jana ; Kolivoška, Viliam ; Pospíšil, Lubomír
The first electron transfer to radiosensitizer etanidazole (ETN) and ETN radical anion formation in buffered aqueous media was studied by means of voltammetric techniques and Electrochemical Impendance Spectroscopy (EIS). The heterogeneous electron transfer rate constant for the first reduction of ETN (radical anion production) k0 for the redox couple and so called E1,7 potential were calculated. The obtained values of k0 and E1,7 potential indicate that ETN compared to some other possible chemical radiosensitizers requires lower energy to accept the first electron during metabolic pathway.
Fullerene C60 in Aqueous Medium
Kocábová, Jana ; Gál, Miroslav ; Hromadová, Magdaléna ; Kavan, Ladislav ; Pospíšil, Lubomír ; Sokolová, Romana
The aqueous solution of C60 was investigated by electrochemical and spectroscopis methods such as UV-Vis, Raman, FTIR and AFM techniques. The association constants of fullerene-gamma-cyclodextrin complex and ,ethanofullerene conjugates with beta-cyclodextrins in aqueous solution were evaluated from the shifts of the formal redox potential of complexed and uncomplexed fullerene. The most suitable techniques for electrochemical characterization of fullerene derivatives proved to be the low-frequency phase-sensitive AC polarography and the steady-state voltammetry.
The Electrochemistry of Natural Pigments
Sokolová, Romana ; Degano, I. ; Hromadová, Magdaléna ; Pospíšil, Lubomír
The electrochemical properties of flavonoid compounds (hemotoxylin, quercetin) were studied in buffered aqueous and non-aqueous solutions. The role of the preceding protonation/deprotonation on the electron transfer was estimated. The absorption spectra of these compounds, which contain a chromophore, were recorded during their oxidation. The electrochemical techniques were combined with GC-MS analysis in order to identify the degradation products. The mechanism of the formation of degradation products will be discussed.
Electrochemical characterization of water soluble fullerenes
Kocábová, Jana ; Gál, Miroslav ; Hromadová, Magdaléna ; Pospíšil, Lubomír
Fullere (C60) is a highly hydrophobic compound and it is considered to be insoluble in water. Different approaches were described for preparing aqueous solutions of C60. One of the possibilities is to create an inclusion complex of the C60 inside a cavity of gamma-cyclodextrin. Recently, we have shown that such complexes are capable of the electrochemical conversion of N2 to ammonium ions.
Electrochemical nitrogen fixation in the presence of fullerene -.gamma.-cyclodextrin complex
Kocábová, Jana ; Gál, Miroslav ; Hromadová, Magdaléna ; Pospíšil, Lubomír
We report on the electrochemical conversion of dinitrogen to ammonia at ambient pressure and 60oC mediated by reduced fullerene (C60) inside a molecular cavity of .gamma.-cyclodextrin (.gamma.-CD) in aqueous solution.
Electrochemistry of selected halogenated pesticides and their complexes with cyclodextrins
Sokolová, Romana ; Hromadová, Magdaléna ; Pospíšil, Lubomír
A detailed investigation of electrochemical properties of triazine pesticides, carboxyimid-type pesticides and benzonitrile pesticides was studied. Their degradation pathways include the protonization reactions coupled with electron transfer and several side chemical reactions. The study of inclusion complexes of halogenated pesticides with cyclodextrins was performed. The inclusion into the molecular cavities markedly influenced the decomposition mechanism of these compounds by protection of reactive groups by cyclodextrin environment. The degradation products were identified by GC-MS analysis and in-situ IR spectroelectrochemistry.
Nanotechnology as potential method for recycling of PET bottles
Kráčalík, Milan ; Mikešová, Jana ; Pospíšil, L. ; Fortelný, Ivan ; Šimoník, J.
Recycling of PET worldwide is not sufficient. This issue results from decreasing molecular weight due to thermal, mechanical and hydrolytic degradation during multiple processing of polymer. The viscosity (next processability) of material can be increased by preparation of nanocomposites (formation of physical network in the polymer/clay system). The improved processing and utility properties of recycled PET were analyzed by rheology, morphology and tensile tests.
Nanokompozity typu recyklát PET/organo-jíl
Kráčalík, Milan ; Puffr, Rudolf ; Pospíšil, L. ; Hrnčiřík, J. ; Fortelný, Ivan ; Šimoník, J.
The processable recycled PET/organo-clay nanocomposites were prepared via melt compounding method as a new possibility of recovery of the used PET bottles. XRD and rheological measurements revealed intercalation of polymer chains into the silicate gallery and significant increase of melt strength of the material, which result in improvement of processability of regranulate.
Communication strategy of Palace Flora
Caletková, Miroslava ; Postler, Milan (advisor) ; Pospíšil, Lukáš (referee)
This work is devided into to main parts. A theoretic one and a practical one. In the first one we can find concepts like: Marketing, Marketing mix, Communication strategy, Communication mix and others. And in the second one threre is analyze of current communication strategy and a proposal of the communication plan of Palace Flora for the year 2008. I was cooperating on this work with the director of marketing department of Palace Flora, Sarka Buskova.

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