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Contamination of soil and sediment by hazardous metals
Pidima, Tomáš ; Komendová, Renata (referee) ; Doležalová Weissmannová, Helena (advisor)
This bachelor thesis deals with soil and sediments from the environmental perspective. For selected heavy metals – cadmium, lead and mercury are given information about their occurrence, characteristics and potential sources of environmental contamination. It is also mentioned legislation dealing with the topic. The limit concentrations in soil and sediments, determination methodology and principles of the most commonly used instrumental analytical methods for these elements are described.
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Reactivity of modified humic gels
Lang, David ; Sedláček, Petr (referee) ; Klučáková, Martina (advisor)
This bachelor thesis deals with humic acid gels and their ability to bind metallic ions on their surface. In the thesis the adsorption of copper ions on humic gels was studied. The gels were prepared by dissolving the humic acid in sodium hydroxide or sodium tripolyphosphate and then by precipitating with hydrochloric acid or magnesium chloride. Adsorption was studied at different concentrations of the copper (II) chloride and measured on UV-VIS spectrophotometer. It was proved from measuring that gels made from sodium tripolyphosphate are adsorbing less copper ions than the ones prepared by sodium hydroxide. Also, the copper ions are bound with smaller force on gels prepared with polyphosphate. Gels precipitated with magnesium chloride adsorb much more than gels precipitated with acid, Thus the extracted amounts are bigger.
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Optimization of WiFi Distributed Nets
Žlůva, Ivan ; Krejzlíková, Libuše (referee) ; Matoušek, Radomil (advisor)
This thesis describes theoretic proposal and two practical realization of multi - point wireless network, first for communications between two endpoints and second for wireless signal coverage of a structured space. The wireless network is realized by the equipment working in unlicenced 2,4GHz and 5GHz ISM band. The wireless device are configured in three different wireless mods: WDS, WDS bridge and AP. This paper contains short information about IEEE 802.11a/b/g/n standard and associated proprietary wireless specifications. Practical workshop describes several variants connections and present the result of throughtput measurements, depending on wireless network topology.
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The effect of investment in tertiary education on gross wages in the region Prague
Diessner, Daniel ; Chytil, Zdeněk (advisor) ; Babin, Jan (referee)
The aim of this work is to determine whether and how higher education affects gross wages. The theoretical part focuses on the theory of human capital, especially investment in education. The theory posits that a higher investment in human capital leads to higher yield, higher wages. The validity of this concept will be tested on the group of respondents who entered the labour market at the turn of millennium. Concentration of candidates with tertiary education in this period has risen considerably, which could cause an imbalance in the labour market. The practical part is based on the work of Mincer (1974). I used Mincer Earnings Function as a basis to build regression model. Partial aim is to prove the declining rate of return on investment in tertiary education using Mincer Equation.
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Aerodynamic design and analysis of "Twin Shark" glider
Krmela, Luděk ; Kouřil, Martin (referee) ; Popela, Robert (advisor)
The thesis contains determination of real aerodynamics characteristics of PW09-135 flap airfoil with help of calibration method via CFD, followed by accomplishment of CFD analysis of parts and the whole Twin Shark glider. Detailed research and optimization was made to flow field quality of fuselage and wing fuselage junction. On the basis of CFD solution was determine a stability control, static margin and angle of attack of a horizontal stabilizer. The thesis concludes an evaluation of results applicability in praxis.
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A possible approach for assessment of general singular stress concentrators on the basis of linear elastic fracture mechanics
Náhlík, Luboš
This paper studies a stress distribution around a general singular stress concentrator tip on the basis of linear elastic fracture mechanics. A procedure for development of stability criteria of general singular stress concentrators is shown. Three different methods for determination of an essential critical stress for crack propagation from the stress concentrator tip are introduced. Each of used method is useful for different mechanism of crack propagation. The described procedures are based on three dissimilar physical basis: on the energetic ground – the generalized strain energy density factor is mentioned, on the failure stress of material grain ahead of concentrator tip and on the size of plastic zone in front of concentrator tip. The numerical results can contribute to better understanding of general stress concentrators behaviour and can be used for design of engineering structures with mentioned type of stress concentrator
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Determination of threshold values of components with protective layers
Náhlík, Luboš ; Bareš, Pavel
The contribution is focused on the influence of existing fatigue cracks in protective layers on fatigue life of structures with protective layers. The problem is solved under conditions of linear elastic fracture mechanics with help of finite element method. Is shown, that in the case of the hard protective layer on the ductile substrate represents existing crack with its tip on the bi-material interface dangerous singular stress concentrator, because of decrease of threshold values of applied loading necessary for crack propagation. Knowledge of crack propagation in protective film is of paramount importance when studying potential failure of the substrate.
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International and national aspects of double taxation
Doležalová, Veronika ; Novotný, Petr (advisor) ; Boháč, Radim (referee)
Veronika Doležalová Mezinárodní a vnitrostátní aspekty dvojího zdan ní 160 International and national aspects of double taxation - Resumé This thesis pays attention to the area of double taxation and its related national as well as international aspects. The reason for discussing this subject was its importance for removing the obstacles that double taxation presents to the development of economic relations between countries. The thesis is divided into five chapters. There are six annexes attached that are important to grasp the topic in its complexity. The first chapter is devoted to theoretical questions of double taxation. It is concentrated particularly on issues such as legal framework of taxation, the national and international treatment of double taxation from the point of view of the principle of origin, measures to eliminate double taxation by way of national unilateral measures or international Double Tax Conventions. The end of the chapter presents examples of national double taxation in the Czech Republic. The rest of the thesis discusses international double taxation. The second chapter is concerned with national aspects of international double taxation and describes legislation related to double taxation in the Czech Republic. As the point of departure to the analysis the following acts were...
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Hygiene Factors Issues of Noise, Dust and Vibrations in the Workplace Grinding Castings
STODOLOVSKÁ, Květa
My diploma work is focusing on the health problems of selected factors in the working enviroment of grinding the metal castings. There are high-risk factors, which are harmful to worker´s health, especially physical stress, noise, dust and vibrations, which are passed on hands. The employer is under the obligation to take precautions to carry on worker´s health, in consideration of exceed the health limits. The aim of this diploma work was setting the efficiency of precautions to health protection in work enviroment. The situation had been monitoring in a company in the South Bohemia over ten years. There were used results of factor´s precautions (noise, dust, vibrations) in work enviroment, where workers grind the metal castings by hand grinders. The monitoring ensemble was created by employess in a company, which makes the metal castings by hand grinders in its work enviroment. To data collecting were used the following methods: non-aligned observation, conversation with the chief of the company, studying of positive law and technical literature incl. test codes of the health institute (department Ceske Budejovice). The data of the test codes were processed by the secundary analysis and summarized to tables and graphs. Within qualitative analysis I determinated four research questions, which were answered gradually in my work: 1)Which precautions are carry out by employers to particular factors of employee´s health protection? 2)What is the factor´ s efficiency? 3)What impact do the precautions have on results of factor´s measuring? 4)Which precautions can I recommend on the grounds of the evalutation of the work enviroment? Both means of collective and individual protection belong to the precautions of worker´s health protection today. The technical, technologiacal and organisational precautions are included to collective protections. The individual precautions are focusing especially on employees and offer the substitute solutions. All precautions are specific to individual factors. I found out, that all precautions, which are used by the employers in work enviroment of metal casting, are effective. Especially we can talk about the precautions to protection of employee´s health against excessive dust (instalation of air ventilation with strong effect), which caused the exceed of dust concetration in work enviroment of grinding. Finally I can say, that this branch of metal casting has been connecting with certain high-risk factors all the time. Although all the protective precautions has been realized, the health limits given for noise, vibrations passed on hands and dust are still exceed. For this reason it´s very important to regularly inform the workers of high-risk factors, which they could meet in their work enviroment of cast grinding.
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