National Repository of Grey Literature 281 records found  1 - 10nextend  jump to record: Search took 0.03 seconds. 

Capillary electrophoresis employed for quantitative characterization of peptide interactions with small ions and cyclodextrins
Kašička, Václav ; Ehala, Sille ; Šolínová, Veronika ; Schimperková, Tereza ; Sázelová, Petra ; Koval, Dušan ; Makrlík, E.
Capillary affinity electrophoresis has been applied to investigate quantitatively two types of non-covalent peptide interactions: i) complexes of pseudopeptide valinomycin with ammonium ion and alkali metal ions, Li+, Na+, K+, Rb+ and Cs+, in methanol, and ii) complexes of enantiomers of dipeptide beta alanyl-D,L-tyrosine and its derivatives with chiral selector, 2-hydroxypropyl-beta-cyclodextrin, in water.

Properties of aprotic electrolytes for lithium-ion accumulators
Staněk, Vladimír ; Máca, Josef (referee) ; Frk, Martin (advisor)
The present work deals with the properties of suitable electrolytes for lithium-ion batteries. The first part described in the current issue of electrolytes for lithium-ion batteries, types of solvents and their properties and methods of measurement properties. The second part is devoted to the measurement of the properties of solvents and electrolytes such as relative permittivity, density and viscosity. Measurement of relative permittivity was focused on the measurement of the solvent mixture with varying the percentage of the solvent. Viscosity and density were measured on a solvent with a lithium salt added (final electrolyte).

Pollutant concentrtion in fog-water at Kopisty (1999 – 2004)
Fišák, Jaroslav ; Chaloupecký, Pavel ; Fottová, D.
In this contribution, results of our studies devoted to analyses of fog water samples collected at the meteorological observatory over the period of 1999 - 2004 are summarized. The study deals with the parameters: conductivity, acidity and following selected ions: NH4+, Na+, Ca2+, Mg2+, K+, F-, Cl-, NO3- and SO42-. Overall, the total concentration of selected ions was remarkably decreasing during the period 2000 - 2004. Specifically, we found out an increase in the cation fraction for NH4+ and Ca2+, and a decrease in the anion NO3- fraction in the mean annual sample.

Binární Homogenní Nukleace H2SO4-H2O
Brus, David ; Hyvärinen, A.-P. ; Lihavainen, H. ; Kulmala, M.
In this study binary homogeneous nucleation of sulfuric acid and water was measured in a laminar flow tube. The concentration of sulfuric acid was determined experimentally by employing bubblers along the nucleation chamber and subsequent ion chromatography analysis. The experimental nucleation rates as a function of sulfuric acid concentration at three different relative humidities, as well as comparison with other studies and atmospheric nucleation are presented.

Tuned semiconductor laser for the diagnostic of the channel waveguides
Ondráček, František ; Skalský, Miroslav ; Čtyroký, Jiří
In contribution is described new measuring set up with tuned semiconductor laser and there are given first results of spectral losses and group refractive index in various channel waveguides by using a resonator method. The waveguides were prepared in special glasses by ion exchanges method and in LiNbO.sub.3./sub. crystal by proton exchange and also by titan difusion. Experimental results have demonstrated accuracy and rate of this arangement. In conclusion we have shown the possibility of the next research.

Study of the properties of a cathode material for Li-ion cells depending on the structure of the active layer
Kršňák, Jiří ; Vondrák, Jiří (referee) ; Kazda, Tomáš (advisor)
This article deals with properties of cathode material of lithium-ion cells study in term of active layer dependence. Aim of the work is to get familiar with problematics of cathode material production and diagnostics and to compare different active layer production methods. The opening of the work is concentrating on rechargeable batteries, mainly lithium-ion batteries and their electrode materials. Practical part is describing method of cathode material production and its characteristics.

Preparation and properties of pyroelectric detectors for optoelectronic applications /III/
Novotný, Jan ; Zelinka, Jiří ; Podvalová, Zdislava ; Malina, Václav ; Vávra, Vladimír ; Franc, J. ; Fronc, Václav ; Fronc, Václav
The single crystals of TGS doped with Pt-ions and with L-alanine were grown as in ferroelectric phase as the full-shaped crystals. The growth rate along the axis c of the doped crystals is much higher than in an undoped one. Morphology, domain structure and hysteresis loops were investgated. The effect of the dopant on the growth velocity is explained on the basis of catalytic action of platinum complexes. The pyroelectric detectors were prepared from these materials and their parameters are presented.

New materials for Li-ion batteries with conversion mechanism
Petr, Jakub ; Straková Fedorková, Andrea (referee) ; Sedlaříková, Marie (advisor)
This thesis is interested in new materials for lithium – ion batteries. Two different samples were investigated, one intercalation and one conversion cathode material. The theoretical part is focused to the structure of cells, their advantages and disadvantages compared to other secondary batteries. Also other materials used in batteries are described. The practical part describes the preparation of cathode materials for subsequent testing by scanning elektron microscopy and thermogravimetric analysis. In conclusions two different materials were evaluated and compared with each other.

New materials for Li-ion batteries with conversion mechanism
Petr, Jakub ; Straková Fedorková, Andrea (referee) ; Sedlaříková, Marie (advisor)
This thesis is interested in new materials for lithium – ion batteries. Two different samples were investigated, one intercalation and one conversion cathode material. The theoretical part is focused to the structure of cells, their advantages and disadvantages compared to other secondary batteries. Also other materials used in batteries are described. The practical part describes the preparation of cathode materials for subsequent testing by scanning elektron microscopy and thermogravimetric analysis. In conclusions two different materials were evaluated and compared with each other.

Possibilities of reprocessing of glycerol layer from the manufacture of bionaphta
Hýža, Bohumil ; Bednařík, Karel (referee) ; Kizlink, Juraj (advisor)
The aim of this thesis was to introduce and apply the possibilities of using waste glycerol from biodiesel production and partly waste low-stiffen coolant from cars that could be applied in industry. At the beginning of the thesis is summarized biodiesel production and its world production. There is more developed biodiesel production in the Czech Republic and in the European Union and some European legal regulations and standards for biodiesel. Also described herein is a composition of biodiesel and the description of the technology of its production. In the theoretical section summarizes the physical and chemical properties of glycerol and there is also summarized the traditional use of glycerol as food, explosives, etc. There are also new procedures that were performed in the experimental part of the thesis. There are described the ion exchange mechanism, ion exchange resin properties and the properties of the acids and salts generated by neutralization with NaOH contained in the waste glycerol. Also is described herein the wood protection and properties of ethylene glycol coolants and properties of boroglycerol and boroglycol as protection for wood and mechanism of their preparation. Next is described the mechanism of dehydration of glycerol to acrolein and options which can perform the synthesis. In the experimental part, the pH of waste glycerol was measured, then was measured the exact amount of NaOH in the glycerol. There is also desribed cleaning of waste glycerol from NaOH using acidic cation exchange resins on columns, or by neutralization with oleic acid, lactic acid and CO2. Further syntheses were performed glycerol borate and ethylene glycol borate. Water amount in ethylene glycol and methanol with water amount in glycerol were found by distillation. Then were prepared boroglycol and boroglycerol. By the amount resulting from the amount of reaction water were observed reaction conditions H3BO3, Na2B4O7•10 H2O and glycerol. At the end was carried out experimental dilution resulting boroglycerol and boroglycol by ethanol, methanol, TMB. Finally, the diluted boroglycerol was deposited on wood. Dehydration of glycerol to acrolein under the catalytic action of KHSO4 was performed. The results are given all the results and discussed the possibility of using the knowledge gained in this work in the industry. In conclusion, there are listed the economic comparison using waste glycerol and crude oil as a raw material and also charts the development of oil prices in 40 years since 1970, and graph of the price of waste glycerol.