National Repository of Grey Literature 78 records found  beginprevious59 - 68next  jump to record: Search took 0.00 seconds. 
Nuclear energetics in CR and in the world
Peroutka, Tomáš ; Bartošík, Tomáš (referee) ; Mastný, Petr (advisor)
This work is about a basic principles of nuclear reaction, creation of nuclear reaction and its development. Here is also described contemporary status and its level of progression. The first part is about a history of nuclear energy – its beginnings and further progress. Next the work deals with a nuclear power stations, nuclear reactors etc. The other part of this work is based on a nuclear waste. Then, I will write about a future of nuclear energy. The last point is creating the enegetic conception of our country.
Preconcentration Techniques for Determination of Uranium Using the Modified Sorbents.
Moos, Martin ; Řehůřková, Irena (referee) ; Kanický, Viktor (referee) ; Kráčmar, Stanislav (referee) ; Sommer, Lumír (advisor)
The work has been focused on the preconcentration techniques for determination of uranium on the modified sorbent, with the final use of ICP-OES and ICP-MS. First ICP-OES at a wavelength of 385.958 nm was used for determination of uranium. Parameters were optimized and the effect of mineral acids (HCl, HNO3), tensides (Septonex, Ajatin) and organic reagents like (4-(2-pyridylazo)resorcinol, ammonium pyrrolidinedithiocarbamate, 8-hydroxyquinoline-5-sulphonic acid and 1,2-dihydroxyanthraquinone-3-sulphonic acid) was observed. For ICP-MS an isotope 238U was chosen. As an internal standard 209Bi (200 ?g•l-1) was used. Modified silica gel was used (Silicagel tethered with C18, C8 alkyls and phenyl) and two types of Amberlite XAD 4 and XAD 16 for the preconcentration of uranium (VI). Commercially produced Amberlite was modified as follows: Drying at 100 °C (24 hours), milled, minced sorbent was selected and fractionated to particles size ranging from 0.32 to 0.63 ?m and finally activated in methanol. The deionised water and Septonex (5•10-3 mol•l-1) at pH 8 were used for Amberlite conditioning. The optimal sorption of uranium (VI) proceeded at pH 8 in the presence of 4-(2-pyridylazo)resorcinol or ammonium pyrrolidinedithiocarbamate with Amberlite XAD-16 moreover with 1,2-dihydroxyanthraquinone-3-sulphonic acid. All organic reagents have mass concentration five time larger than uranium . For the elution of uranium the mixture of 1 mol•l-1 HNO3 with acetone (ratio of 1:1) was used. Acetone was evaporated and the final analysis performed using ICP-OES. The preconcentration of uranium (VI) using Silicagel-C18 conditioning was performed with ethanol, deionised water and Zephyraminu (5•10-4 mol•l-1) at pH 8. For the Silica-C8 and Silicagel-Phenyl the same conditioning procedure without zephyramin was used. Silica-C18 had the highest sorption efficiency with 1,2-dihydroxyanthraquinone-3-sulphonic acid, Silicagel-C8 with ammonium pyrrolidinedithiocarbamate and Silicagel-Phenyl with 8-hydroxyquinoline-5-sulfonic acid, all organic reagents have mass concentration five time larger than uranium concentration. As an optimal elution mixture acetone and ethanol (ratio of 1:1) in the presence of 1 mol•l-1 HCl was evaluated. Acetone and ethanol was evaporated and the final analysis was performed using ICP-MS. Silicagel-C18 was evaluate as the most effective in the presence of zephyramin and 1,2-dihydroxyanthraquinone-3-sulphonic acid. Sorption was also tested in the presence of 20 ?g•l-1 microelements (Be, V, Co, Ni, Y, Pb, Th, Cd) and in the presence of a defined concentrations of K, Na, Ca, Mg, Al and Fe. Direct analysis of uranium was carried out on samples of water from the river Ploucnice and Turonian aquifers containing uranium, 3,5 and 19,3 ?g•l-1. Different type of water required preconcentration of uranium (VI) on Silica-C18 in the presence of 1,2-dihydroxyanthraquinone-3-sulphonic acid and zephyramin. The analysis results gave statistically satisfactory results, which were confirmed using standard addition of 20 ?g•l-1.
Nuclear energetics in CR and in the world
Peroutka, Tomáš ; Bartošík, Tomáš (referee) ; Mastný, Petr (advisor)
This work is about a basic principles of nuclear reaction, creation of nuclear reaction and its development. Here is also described contemporary status and its level of progression. The first part is about a history of nuclear energy – its beginnings and further progress. Next the work deals with a nuclear power stations, nuclear reactors etc. The other part of this work is based on a nuclear waste. Then, I will write about a future of nuclear energy. The last point is creating the enegetic conception of our country.
Determination of radionuclides in water and sediments
Bílek, Jiří ; Holubová, Zuzana (referee) ; Komendová, Renata (advisor)
This thesis has been prepared for DIAMO, Branch GEAM Dolní Rožínka. Literature research includes a description of the ionizing radiation, natural radionuclides, mining of uranium ore and mineral deposits; Běstvina and Licoměřice. The experimental part includes sampling, analysis and evaluation of the content of selected radionuclides in the two selected locations. The content of uranium and radium in sludge from mine water treatment plant is determined annually by an external laboratory, using of semiconductor gamma-spectrometric analysis (GSA). Determination of both radionuclides in waters in these areas is carried out in the Centre of testing laboratories (SZLAB) in Dolní Rožínka. Uranium and radium activity is below the detection limit. Sludges from Běstvina, according to the results of external laboratories, routinely show activity of both radionuclides. But activity in the waters from this locality is below the detection limit. The goal of this diploma thesis is to verify the radionuclide content in sludge from CDV Běstvina by another method. As a comparative method was chosen determination of uranium using the UV-VIS spectrophotometry with separation on silicagel. Location Licoměřice was chosen as a reference. Like a supplementary method for determining the concentration of uranium was chosen ICP-MS. For the determination of the radium was chosen radiochemical method scintillator ZnS (Ag).
MONITORING OF URANIUM IN DRINKING WATER IN THE SOUTH MORAVIAN REGION AND ITS ANALYSIS.
Hanusková, Vendula ; Doležalová Weissmannová, Helena (referee) ; Ing.Dita Janečková, (advisor)
The determination of uranium in samples of the enviroment was considered for liquadeted chemical toxicity of uranium and it is impossible to leave out a potential occurrence in drinking water. The purpose of this diploma thesis was the monitoring of preselected public water supplies in the South Moravia and post action analysis of those samples. That was all on the basis of the requierement of the Regional Hygiene Station. For determination of trace concentrations of uranium in drinking waters the method ICP-MS (Inductively Coupled Plasma with Mass Spectrometry) was chosen. All of the results were then summarized and evaluated. At the end are proposed feasible solutions and precautions for public water supplies operators.
Equipment for the enrichment of nuclear fuel
Ostrezi, Matěj ; Martinec, Jiří (referee) ; Suk, Ladislav (advisor)
The aim of this bachelor thesis is to review the current knowledge and possibilities dealing with an enrichment of the nuclear fuel and to describe particular methods of the enrichment. An attention is paid to basic principles, functions, technological and power requirements and efficiency of the discussed methods. In conclusion, a difficulty of the enrichment process is pointed out and a balance sheet of the economic impact is made.
The current state of mining and uranium reserves
Vondra, Marek ; Nerud, Pavel (referee) ; Šnajdárek, Ladislav (advisor)
This bachelor thesis is engaged in current state of uranium mining. It describes development of uranium mining on the area of the Czech Republic from the beginning to current state of mining. There are summarized current uranium reserves in the world, with the most important mining areas included. The treatment of uranium ore is described, with its influence on the environment and the remediation of affected mining area. In the last section, the possible ways of uranium usage in the future are mentioned.
Fuel of nuclear reactors and fuel cycle
Bátěk, David ; Nerud, Pavel (referee) ; Šen, Hugo (advisor)
This bachelor thesis describes nuclear fuels used in today's nuclear reactors as well as parts of fuel cycle, which includes all activities like uranium mining and prepairing, energy utilization and storage at the end of a cycle. There are also information about world production of uranium and posibilities of manipulation with used nuclear fuel, including transmutation technologies.
Analytical methods applied for the evaluation of environmental contamination by uranium ore mining
Bílek, Jiří ; Holubová, Zuzana (referee) ; Čáslavský, Josef (advisor)
This thesis deals with the testing procedures used in monitoring of environmental contamination after uranium ore mining in the uranium mine in Dolní Rožínka. It deals with the determination of radioactive elements radium, uranium and radon. The methods used for the determination of radioactive elements in mine laboratory in Dolní Rožínka are described. The thesis also mentions other applicable methods for determination of uranium. The metods of determination of manganese, iron and other metallic elements are also summarized in brief.The values of concentrations of monitored analytes in selected locations are presented at the end of the thesis. These values, which were provided by laboratories in Dolní Rožínka, are valid for 2010.
International trade of uranium and its impact on world politics
Štětkář, Matěj ; Černá, Iveta (advisor) ; Bolotov, Ilya (referee)
I have written my bachelors thesis on International trade of uranium and its impact on world politics. The main goal is to analyze the evolution of international trade of uranium together with its impact on world events. Statistical and non-statistical data I have mainly taken from the official website of World Nuclear Organization and from statistical outlines made by OECD and IAEA. Based on the research, I have analyzed the Supply and Demand on the international market of uranium together with stating the main areas of extraction. Uranium is due to its importance in the energy and military industry very important strategic raw material that had great significance in the field of international relations in the past. The international trade of uranium is naturally connected with regulatory restrictions that are enforced by international nuclear organizations. The view of this work is the analysis of the impact of uranium on the world events in the last 50 years together with the prediction of the evolution of the international trade of uranium into the future. Although uranium is becoming more and more important source of energy in the future, it is still a subject of many controversial discussions.

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