National Repository of Grey Literature 85 records found  beginprevious39 - 48nextend  jump to record: Search took 0.00 seconds. 
Determination of Copper in Food Supplements by AAS
Hadbavníková, Alexandra ; Hraníček, Jakub (advisor) ; Nováková, Eliška (referee)
EN This bachelor thesis deals with the determination of copper in the form of copper ions in selected food supplements by atomic absorption spectrometry. The first step of the experiment was to find the optimal measurement conditions for the parameters: beam height above the burner edge, burner horizontal position, fuel flow rate, burner angle and spectral interval width. Subsequently, the calibration dependence was determined and the basic measurement characteristics were calculated: repeatability, sensitivity, limit of detection (0.019 mg dm−3 ) and limit of quantification (0.065 mg dm−3 ) at the burner position 0 ř. Interference studies were performed for the presence of iron, manganese and sodium elements in selected food supplements because of theirs increased concentrations. These selected food supplements were analysed: Spektrum 50, Supradyn Energy Complex, Center from A to iron, GS Extra Strong Multivitamin, Caltrate Plus, DAS Gesunde Plus, A-Z Multispektrum and Calibrum 50 Plus. Selected samples were converted to solutions using three procedures: decomposition in water at room temperature, decomposition in nitric acid at room temperature and decomposition in nitric acid at high temperature. The determination of copper itself was performed using a GBC 933 AA spectrometer and the results...
Produkce alelopatických látek u vybraných bylin a jejich biologická účinnost
Nováková, Eliška
The thesis is focused on the study of allelopathy and allelopathic effects of Ambrosia artemisiifolia and Festuca rubra on selected species of herbs. The first theoretical part describes plants relationships and available information about allelopathy. The second part deals with the influence of Ambrosia artemisiifolia on the growth of Plantago lanceolata, Lotus corniculatus, Arrhenatherum elatius, Festuca rubra, Phacelia tanacetifolia and Pisum sativum in outdoor conditions in different cultivation substrates. The effect of extracts from roots of Festuca rubra and synthetic m-tyrosine on the germination of seeds Ambrosia artemisiifolia was evaluated. The obtained results confirmed the effect of Ambrosia artemisiifolia on the growth of the studied plants and the effect of the tested solutions on germination seeds of Ambrosia.
Comparison of mercury determination by electrochemical or UV-photochemical vapor generation with detection by atomic fluorescence
Šandlová, Petra ; Červený, Václav (advisor) ; Nováková, Eliška (referee)
~ 5 ~ Abstract The functionality of the add-on Millennium Merlin Satellite module towards the PSA Millennium Excalibur atomic fluorescence spectrometer for determination of mercury has been proven. At the same time, the ratios of the average signal to the sample standard deviations of the results of repeated measurements of this module were compared with the mercury determination using an atomic absorption spectrometer ContrAA700 with a radiation source with continuous spectrum and high resolution. In model experiments performed on an atomic absorption spectrometer, the experimental conditions of the cold vapor detection above the level of the elemental mercury were optimized. The flow rate of argon and hydrogen, the temperature of the detection cell and the storage bottle and the mercury evaporation time were optimized. It has been shown that the reduction environment in the detection tube reduces the signal. The need to heat the detection tube up to 650 řC has been surprising. The causes of this phenomenon were discussed and confronted with data from the available literature. Subsequently, the mercury signal was monitored unde roptimal conditions found on the AAS, using an atomic fluorescence PSA Millennium Excalibur spectrometer with an additional Millennium Merlin Satellite unit for mercury...
Determination of lead and zinc in great tits blood
Greguš, Viktor ; Hraníček, Jakub (advisor) ; Nováková, Eliška (referee)
EN Determination of heavy metals in urban living passerine birds organism has been considered as suitable method for monitoring pollution of human enviroment which these elements can cause. This study deals with determination of zinc and lead in dried great tits blood samples using inductively coupled plasma-mass spectrometry technique. Dried blood samples were weighed, solubilized in nitric acid and hydrogen peroxide and microwavelly digested. Calibration standards for determined elements were prepared and basic analytical characteristics of the measurement were determined. Matrix interference was examined by measuring the recovery of element determination presented as a ratio of the slope of standard addition to the certified reference material of whole blood sample and the slope of external calibration.
Development of a Small Family Business
Nováková, Eliška ; Konečný, Štěpán (referee) ; Koráb, Vojtěch (advisor)
The bachelor thesis deals with the development of a small family business. The theoretical part contains business papers. This is followed by an analytical section describing in detail both the internal and external environment of a specific business. Its‘ position is determined, based on the strategic analysis, then things are designed to help increase the company revenue. The last part includes several suggestions, that should result in the higher sales.
The Efficiency of Machines Evaluation for Production Task Ensuring
Nováková, Eliška ; Průša, Michal (referee) ; Jurová, Marie (advisor)
The diploma thesis deals with evaluation of obtained data from selected production equipment. The theoretical part is focused on production management, description of information production systems and defining methods for evaluation of machine efficiency. The practical part describes the current situation of selected productive sections and outputs from two compared systems. Next step is the calculation of OEE indicators, evaluation of individual workplaces and suggestions for improvement.
Influence of technological process of powder painting on the quality of silver-plated components in gas insulated substation - GIS
Nováková, Eliška ; Prosecký, Vít (referee) ; Kubíček, Jaroslav (advisor)
The thesis deals with the topic of silver coating on the inner surface of the tubes made of aluminum alloy EN AW-6101B. The high affinity of the aluminum for the oxygen, the heterogeneity of the surface and the presence of the hydrogen in the base material, are the properties which hinder the formation of metallic coating on the surface of the aluminum alloy. The saturation of the base material with the hydrogen, e.g. due to the pretreatment of the surface or by the process of creating of coatings, may under certain conditions cause the defects of the silver coating in the form of the bubbles (blisters). Other factors that may affect the quality of the silver coating are the way of creating of the interlayer and the conditions for the electrolytic deposition of the silver.
Hydride generation of bismuth for atomic absorption and fluorescence spectrometry.
Kolrosová, Marta ; Musil, Stanislav (advisor) ; Nováková, Eliška (referee)
This master's thesis deals with the optimization of conditions of chemical hydride generation (HG) of bismuth, its atomization and detection by atomic absorption spectrometry (AAS) and atomic fluorescence spectrometry (AFS). Two types of atomizers were used for atomization of volatile species, a miniature diffusion flame for AAS as well as for AFS and a flame-in-gas-shield atomizer for AFS. At first, the parameters of HG in a flow injection mode were optimized - the concentration of hydrochloric acid, the concentration of sodium borohydride and the volume of the reaction coil. Subsequently, the atomization conditions were optimized using both atomizers. The parameters optimized were hydrogen fraction, total gas flow rate and observation height. Due to the more complicated construction of the FIGS atomizer, more parameters were studied, such as the oxygen flow rate through the capillary and the flow rate of shielding argon required for shielding the free atoms. A special part of the thesis dealt with the optimization of the optical path of the atomic fluorescence spectrometer, the selection of an interference filter and the optimization of a power supply of an electrodeless discharge lamp. It was found that under optimum conditions of generation, atomization and detection excellent detection limits...
UV-photochemical generation of cadmium volatile compounds with atomic spectrometric detection
Horová, Kateřina ; Nováková, Eliška (advisor) ; Červený, Václav (referee)
The aim of this master's thesis has been to develop and optimize the method of UV- photochemical vapor generation of cadmium volatile compounds for atomic fluorescence spectrometry. Two configurations with different materials wrapped around the low-pressure mercury vapor lamp were tested. I experimentally determined optimal conditions for both systems; the optimalized parametres included selection of photochemical reagent and its concentration, flow rate of liquids and gases, and the lenghth of the reaction coil. After finding the optimal parametres I determined the figures of merit of the method. I found from the measured data that UV-photoreactor with the quartz capillary provided lower limits of detection and thus was more suitable for generation of cadmium volatile compounds. With this arrangement and using the ferrous sulphate heptahydrate as the chemical modifier I obtained limit of detection 2,0 µg·l-1 , limit of determination 7,0 µg·l-1 , linear dynamic rate LOD-50 µg·l-1 and repeatibility 0,35 %. I also carried out the interference study in my thesis and determined the generation effeciency of cadmium volatile compounds. The interference study shows the influence of mineral acids (HCl, H2SO4, HNO3), their salts (NaNO2, NaNO3) and transition metals (Co, Ni, Cu). Based on literature review I also...

National Repository of Grey Literature : 85 records found   beginprevious39 - 48nextend  jump to record:
See also: similar author names
57 NOVÁKOVÁ, Eliška
50 NOVÁKOVÁ, Eva
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3 Nováková, Elena
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50 Nováková, Eva
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