National Repository of Grey Literature 87 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Atomization of bismuthane in two flame atomizers for atomic fluorescence spectrometry
Štádlerová, Barbora ; Kolrosová, Marta ; Dědina, Jiří ; Musil, Stanislav
Atomization of bismuthane in the minature diffusion flame and the flame-in-gas-shield atomizer by hydride generation coupled with atomic fluorescence spectrometry.
Development of Instrumentation and Methodology for Elemental and Speciation Analysis of Arsenic Based on Hydride Generation and on Atomic Fluorescence Spectrometric Detection
Marschner, Karel ; Dědina, Jiří (advisor) ; Kanický, Viktor (referee) ; Spěváčková, Věra (referee)
(EN) The presented dissertation is devoted to hydride generation from arsenic species and its application for speciation analysis based on atomic fluorescence detection. Hydride generation from toxicologically relevant arsenic species was optimized in order to achieve a 100% efficiency. The resulted experimental setup was subsequently used for speciation analysis of arsenic in human urine by high performance liquid chromatography with detection by atomic fluorescence spectrometry. The accuracy of the developed method was verified by comparative analyses of human urine samples collected from five individuals with an independent reference method. The cleavage of As-C bond during the reaction of methylated arsenic species with tetrahydridoborate(1-) (THB) in acidic media was studied in detail. Pronounced demethylation of methylated arsenic species was found during the reaction of THB with HCl, H2SO4, and HClO4 while hydride generation from CH3COOH or TRIS buffer after prereduction with L- cysteine resulted in the exclusive formation of the corresponding hydrides. Firstly, this phenomenon can endanger the accuracy of arsenic speciation which is based on hydride generation of substituted arsanes. Secondly, the more complex arsenic species can be converted to the hydride. That was demonstrated on hydride...
Determination of Inorganic Arsenic in Samples of Marine Origin
Marschner, Karel ; Matoušek, Tomáš ; Dědina, Jiří ; Musil, Stanislav
A fast screening method for determination of inorganic arsenic in marine samples was developed. This method is based on selective\nhydride generationanddetectionby inductively coupled plasmamass spectrometry. Using a high concentration of hydrochloric acid\ntogether with hydrogen peroxide for hydride generation leads to selective conversion of inorganic arsenic species into arsane. The\naccuracy of this method was verified by comparative analyse by high performance liquid chromatography coupled with hydride generationandatomic\nfluorescence detection.
Stories as a source of knowledge for decision-making
Kejzlarová, Nina ; Mládková, Ludmila (advisor) ; Dědina, Jiří (referee)
The aim of this Master thesis has been to summarize the current theoretical knowledge about the possibilities of using stories in management, especially their use as a tool for better and easier decision-making in a nowadays turbulent period, and to summarize the aspects explaining their positive contribution in this issue. In the practical part, the thesis focuses on exploring the use of stories by students of the University of Economics in Prague to decide on subjects and teachers. More specifically, the aim has been to find out how students are influenced by stories told by their colleagues in selection of subjects and teachers, how actively students use stories for obtaining and transmitting knowledge and information, in what form stories spread among students, which communication channel students prefer and why, what the quality of stories is and what the differences between Bachelor's and Master's students in those aspects are. The purpose of this research has been to demonstrate the power of stories in influencing individuals decision-making, applicable also to classical management in the corporate environment. As a research method, a combination of a quantitative and simple qualitative analysis in the form of the semi-structured questionnaire has been used. Based on the research, it has been found out that students do decide about subjects and teachers on the basis of others'stories, they do actively seek those stories and they do prefer personal narrative from friends, as this form has turned out to be considered as the most reliable for students, and also the one which will find the most consistent validation in what they will experience next. Students of Bachelor's and Master's studies differ in the selected communication channel and the activity with which they search for and use the stories.
Comparison of organizational architecture of small and medium companies in the financial consulting sector
Král, Dorian ; Dědina, Jiří (advisor) ; Cejthamr, Václav (referee)
The thesis is focused on the comparison of organizational architecture of selected companies-OVB Allfinanz, a.s., Partners Financial Services, a.s. and Broker Trust, a.s. The aim of the thesis is to examine individual elements of organizational architectures in relation to the overall performance of selected organizations. Based on the theoretical and practical knowledge, the basic elements of organizational architecture will be presented for each of the selected companies. In the practical part was set up a questionnaire focused on the recognition of executive management styles. At the end of the thesis the results are confronted with the theoretical background.
The Impact of Management Styles on Employee Efficiency
Stasa, Michele ; Dědina, Jiří (advisor) ; Cejthamr, Václav (referee)
The subject of the thesis is an analysis of management styles used in different departments and the impact of these styles on the employee efficiency in the concrete company. First theoretical part describes the main terms and definitions from leadership and management styles with regard to the employee efficiency. Defining the term efficiency and its factors such as motivation, satisfaction or turnover is one of the problematic areas of this work. Second practical part consists of the presentation of the company, analysis of the current problems and analysis of the management styles used in the company and its impact on the company culture and the employee efficiency. Summary is based on recommendations for the management regarding the efficiency of employees and the whole company.
The influence of the applied leadership and management styles on employee performance
Tokár, Adam ; Dědina, Jiří (advisor) ; Cejthamr, Václav (referee)
The bachelor thesis deals with the influence of the leadership and management styles on the determinants of employee performance. The main goal of the thesis is to broaden the horizons in the field of leadership and management approaches, and to point out the impact of specific styles on performance. The theoretical part defines the basic concepts of leadership and management, summarizes the styles of leadership, concentrates also on the issues of performance and its determinants. The practical part includes analysis of expert articles and comparison of selected countries based of performance factors. Each research has its own assumptions, model, specific saving and presentation of results. Finally, recommendations are set for use in a practical environment.
Hydride generation study for arsenic speciation analysis with AAS and AFS detection
Svoboda, Milan ; Dědina, Jiří (advisor) ; Spěváčková, Věra (referee) ; Komárek, Josef (referee)
The general aim of this work was a development of methodology and instrumentation for speciation analysis based on the combination of the selective generation of substituted hydrides with atomic absorption or atomic fluorescence spectrometry detection. The first topic of this work was the development of methodology and instrumentation for arsenic speciation analysis based on selective generation of substituted arsines with trapping in the cryogenic trap (U-tube packed with chromosorb) with AAS detection (HG- CT-AAS). The conditions of the selective hydride generation approach as well as working procedure of the cryogenic trap were optimized (appropriate approach for hydride generation, set up of heating program of cryogenic trap, new dryer - cartidge with NaOH, elimination of unspecific absorption, decreasing of the detection limits). The second important part of the work lay in applying of the developed method for arsenic speciation analysis in a homogenized mouse liver tissue. The direct slurry sampling to hydride generator was develop. Moreover the information about oxidation state (iAsIII,V , MAsIII,V a DMAsIII,V ) was obtain. The effect of relevant experimental parameters such as tetrahydroborate concentration, TRIS buffer concentration and time of pre-reduction of the samples by L-cysteine...
Optimization of generation and atomization of arsines for speciation analysis by atomic fluorescence spectrometry
Marschner, Karel ; Dědina, Jiří (advisor) ; Komárek, Josef (referee)
Speciation analysis of arsenic based on selective hydride generation and detection by atomic fluorescence spectrometry have been studied in this work. It was found that under optimum conditions of atomization in the flame in gas shield atomizer, sensitivity was approximately twice higher and detection limit was about four times lower compared to miniature diffusion flame, which is a standard atomizer for atomic fluorescence spectrometry. The conditions to generate hydrides from both inorganic forms of the arsenic, i.e. from arsenite and arsenate, with the same efficiency have been found in the batch arrangement, by using 1 mol dm-3 hydrochlorid acid and 1% solution of tetrahydridoborate. To determine only trivalent form, TRIS buffer at pH 6.00 was used together with 1% sodium tetrahydridoborate. The detection limits found for inorganic arsenic, i.e. for arsenite and arsenate, respectively, were 15 ng dm-3 and 9 ng dm-3 . It was found that in the batch arrangement under these conditions it is possible to generate corresponding hydrides methylarsonate and dimethylarsonate with the same efficiency as from the inorganic form. Finally, it was found when slightly changing the gas-liquid separator design in order to introduce the mixture of tetrahydridoborate with hydrochloric acid to the bottom of the...

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2 DĚDINA, Jan
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