National Repository of Grey Literature 898 records found  1 - 10nextend  jump to record: Search took 0.25 seconds. 

A method of sample combustion for determination of 14C activity
Světlík, Ivo ; Michálek, V.
A method of samples combustion for purpose of 14C activity determination by the routine of benzene synthesis and liquid scintillation measurement.

The use of bioimpedance analysis for kidney function evaluation
Veselková, Alena ; Šrámek, Petr (advisor) ; Švára, František (referee)
Objective: To calculate glomerular filtration (GF) through the use six available methods to estimate GF and measure impedance parameters phase angle () and fat free mass (FFM) by using multifrequency and monofrequency measurement. Select one method of estimating GF as a strict method of estimation GF for this study and by using linear regression relate with other method of estimating GF and impedance parameters measured () and FFM. Consider if () and FFM are significant parameters to improve methods of estimating GF given below (MDRD-A, MDRD-B, CLCG, CLcysC). (...) Conclusions: Impedance parameters () and FFM correlate with GF, decreasing GF cause decreasing of these impedance parameters. This study proved very close relationship between parameters FFMx and FFMc, obtained by using two different kinds of measuring (R2 - FFMx and FFMc = 0,843). Method of bioimpedance is ready to other validation and to develope bioimpedance scale to estimate renal function.

Analysis and modification of thin layers using ion beams
Jonner, Jakub ; Lörinčík, Jan (referee) ; Bábor, Petr (advisor)
This diploma thesis deals with analysis and modification of thin layers using ion beams. The first part of this diploma thesis deals with phenomena accompanying ion beam bombardment of solid matter. The second part of this diploma thesis is concerned with Secondary Ion Mass Spectroscopy (SIMS) and Low Energy Ion Scattering (LAIS). This work convey some basic information about these two techniques and it also deals with some benefits result in their connection into parallel depth profiling mode (such as better depth resolution of the LEIS profile, quantification of the SIMS). These benefits are demonstrated on MoSi film measurement. Within the framework of this thesis a new UHV manipulator was designed. This new UHV manipulator is equipped with precise stepper UHV motor and since the proportions are smaller, the manipulation with a sample in a space limited UHV chamber is much more comfortable and more precise. The third part of this diploma thesis deals with ion-beam induced transformation of epitaxially grown Fe films with thickness of 22 monolayer (ML) and 44 ML on Cu(100) single crystal at room temperature. Metastable Fe films of 22 ML thickness were prepared in CO pressure and 44 ML Fe films were prepared by co-evaporation of Fe with Fe64Ni36 (invar). Structural changes are analyzed by scanning tunneling microscopy and low-energy electron diffraction. The aim of this thesis is to discuss the influence of the sputtering parameters such as ion dose and ion energy on the nucleation of bcc nanocrystals, their growth, final shape and size. The influence of different Ni concentration on stability of 44 ML thick Fe films is also discussed.

Monitoring of photocatalytic activity
Jurášek, Martin ; Drbohlavová, Jana (referee) ; Veselý, Michal (advisor)
Bachelors thesis deals with kinetics of redox dye 2,6-dichloroindophenol degradation. Thanks to photo-reduced form is colourless, it’s suitable to use it for photocatalytic activity rapid assessment of the thin titanium dioxide layers. The thin layers of TiO2 were prepared using nano-crystalline titanium dioxide suspension with amorphous silica. These layers, including layers of redox dye, were deposited by material printing process. The rate of redox dye photo-reduction was monitored in dependence of number of thin titanium dioxide layers at different UV irradiance. Redox dye concentration was studied using UV-VIS spectroscopy.

Preparation of grafted PP with diferent concentration of MA and IA
Běťák, Lukáš ; Žídek, Jan (referee) ; Kučera, František (advisor)
The bachelor thesis deal with a preparation and a characterization of polypropylene grafted with anhydrides carboxylic acids in a melt. A present knowledge about radical grafting was summarized in a theoretical part. Samples of polypropylene grafted with itaconic anhydride (IA) and maleic anhydride (MA) were prepared in the experimental part. 2,5 dimethyl 2,5bis(tert-buthylperoxy)hexane (Luperox 101) was used as a radical initiator. A Brabender mixer was used for experiment, conditions for grafting were 210 °C, 30 RPM and 6 min. Weight concentration of grafted monomer was in range 0,25 wt % 1 wt %. It was found that a degree of conversion depended on concentration ratio of initiator to monomer. Attached carboxylic groups to polypropylene backbone were confirmed by FTIR spectroscopy. The percentage of grafting was determined by acid-base titration.


Evaluation of ecotoxicity of selected chemicals with using algal test.
Kosárová, Hedvika ; Pavlovský, Jiří (referee) ; Doležalová Weissmannová, Helena (advisor)
This bachelor thesis deals with the ecotoxicity of 2 - [(2,6-dichlorophenyl)aniline] benzene acetic acid (diclofenac), ?-methyl-4-(2-methylpropyl) benzene acetic acid (ibuprofen) and mixture of cadmium and diclofenac and studies the above using algal toxicity test in accordance with ISO 8692. The theoretical part describes the issue of pharmaceuticals in the environment, and characteristics of standards algae tests and alternative tests. Freshwater green algae Desmodesmus subspicatus were used as testing organisms in all the implemented algal toxicity tests. By the means of these tests, the IrC50 values for the standard substance potassium dichromate, the drugs diclofenac and ibuprofen and cadmium were determined. The toxicity of cadmium in mixture with diclofenac was also evaluated.

Modification of RAPID 200 Aircraft for Towing
Seďa, Ondřej ; Daněk, Vladimír (referee) ; Píštěk, Antonín (advisor)
This master’s thesis deal with design modification of the RAPID 200 (Skyleader 200) airplane for towing at compliance with maximum take-off weight 450 kilogramme. A necessary construction modification, a weight analysis these adjustments and a balance verification are included. The thesis contains of power plants installation consisting from the M 132 engine and the V 541.2 propeller, a towing gear and a landing gear, a load calculation of power plants and towing gear and basic flight performance calculation too. Last but not least valuation of operation ekonomy, operation characteristics assesment and a using of the airplane for specialized duty are included.

Artificial sweeteners and their potential impact on the ecosystem
Vavrčíková, Veronika ; Mravcová, Ludmila (referee) ; Zlámalová Gargošová, Helena (advisor)
This diploma thesis deals with the determination and ecotoxicological assessment of artificial sweeteners. The diploma was focused on monitoring the most commonly used sweeteners, which includes acesulfam-K, cyclamate, saccharin and sucralose. These sweeteners were analyzed by liquid chromatography with mass spectrometry, using solid phase extraction for their concentration. The samples for their determination were taken from wastewater treatment plant in Modrice. Artificial sweeteners are synthetically produced substances, which is the main reason for their occurrence in waste water. Some of them are not efficiently removed from the wastewater treatment plant and penetrate into the environment. Analysis of the samples was found, that sucralose penetrates into the environment. The ecotoxicological effect of the sweeteners was evaluated via aquatic organisms, namely on the freshwater crustaceans Thamnocephalus platyurus and Daphnia magna, on the water plant Lemna minor, and the battery of tests was supplemented by a representative of the destructors Vibrio fischeri. For all sweeteners, LC20, EC20 and IC20 values were determined. For some sweeteners, LC50, EC50 and IC50 values were also determined. During testing, saccharin represented the highest toxicity.