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Determination of selective transition metals using electrochemical generation of volatile species with AAS detection
Mlejnek, Tomáš ; Hraníček, Jakub (advisor) ; Červený, Václav (referee)
The aim of this bachelor's thesis is to study the possibilities of electrochemical generation of volatile forms of copper, nickel and zinc with atomic absorption spectrometry detection. The electrochemical generation of volatile compounds were set in continuous flow analysis. A laboratory made on-membrane electrolytic cell with platinum electrodes was used for all experiments. Optimization of different conditions for electrochemical generation for specified analytes was determined via empiric methods. Optimized parameters were as follows: flow rate of carrier gas and electrolyte and generation current. The calibrations under the optimal values for both copper and zinc were measured. Other extended measurements were performed with zinc. For example, the optimization of electrolyte concentration, the influence of the atomization temperature, reversing polarity of the electrodes, the flow rate of electrolyte, the influence of salts as electrolytes, influence of DDTC, Antifoam B and oxygen addition. Possibilities of determination of zinc compounds by electrochemical generation were investigated at the end. Key words Electrochemical generation, volatile compounds, atomic absorption spectrometry, non- membrane flow-through electrolytic cell, quartz tube atomizer, copper, nickel, zinc
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Manufacturing, use and properties of nickel alloys
Kejha, Richard ; Blažík, Petr (referee) ; Záděra, Antonín (advisor)
This thesis presents a literary recherche of matters concerning on industrial use of nickel aluminates, especially on refractory and incandescent alloys. In this dissertation are witten basic market brands of constructional, refractory and incandescent alloys, and then their selected representatives. There are listed the basic properties of given materials and their approximate comparison. The basic constructional materials are monel alloys based on Ni-Cu, which achieves very good mechanicl properties and excellent corrosion resistence. Refractory and incandescent materials are mostly based on Ni-Cr or Ni-Cr-Fe. Their mechanical features are very different in normal conditions and even in high operating temperatures because there are used different kinds of addition elements and their concentration. These alloys are usually additioned by elements like W, Cu, V, Al, Nb, Ti, Ta, Mo, Co, Zr, B.
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Contamination of soils with selected metals due to the railway transport
VONDRUŠKA, Jan
This work deals with the determination of metals in soils taken close to the railway. Copper, zinc, nickel and chromium were selected as indicators of the environment contamination. Samples were taken from three localities in South Bohemia. These localities were chosen on the basis of different types of railway tracks (electrified and nonelectrified) and different frequency of train connection. Atomic absorption spectrometry was used for the determination of the metals. An AAS Thermo Scientific iCE 3500 spectrometer served to determine individual analytes. The highest level of copper pollution was detected for samples taken close to the railway with electrified track and with high frequency of train connection. The highest Cu concentration (66.30 mg/kg) was determined in the soil sample from 20cm depth. The highest level of zinc pollution was detected for samples taken in the distance of 3 m from the railway with electrified track and with high frequency of train connection. The highest Zn concentration (641.77 mg/kg) was determined in the soil sample from 30cm depth. The highest concentrations of other metals (Ni and Cr) were detected for the railway with nonelectrified track and with low frequency of train connection. The highest concentrations of Ni and Cr were 21.89 and 54.89 mg/kg, respectively. These concentrations were obtained for samples taken close to the railway.
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Distribution, binding and mobility of Ni in soil in the closed Ni mining area in the vicinity of Křemže
Pipková, Zuzana ; Ettler, Vojtěch (advisor) ; Vaněk, Aleš (referee)
Soils in the vicinity of Křemže in the Southern Bohemia are developed on altered ultrabasic rocks. The occurrence of Ni-hydrosilicate and Fe-rich ores in this area lead to their mining mainly during 19th century, then during the World War II. This thesis is focused on distribution and availability of Ni, Cr and Co and accompanying elements in soils at former mine and prospection sites (2 soil profiles and 32 topsoil samples at historical surface mine area). In all soil samples, physico-chemical parameters (pH, TOC, TS) and bulk concentrations of Al, Ca, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb and Zn were measured. In addition, deionised water, DTPA and EDTA extracts were used to determine the (bio)availability and mobility of these elements. Some of trace elements were found in elevated concentrations in the mining area topsoils; mean Ni: 1175 mg/kg (range 545-2849 mg/kg), mean Cr: 416 mg/kg (240-849 mg/kg), mean Co: 127 mg/kg (65-238 mg/kg), mean Fe: 49155 mg/kg (30460-113800 mg/kg), mean Mg: 12648 mg/kg (8795-18770 mg/kg) and mean Mn: 1480 mg/kg (1028-2319 mg/kg). In soil profiles the Ni availability decreased with depth. In the uppermost organic O horizon in forest soil profile, 19.5 % and 23.8 % of total Ni was extracted by DTPA and EDTA, respectively. The extractabilities are decreasing down to mineral...
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Concentration of nickel in wastewater and its removal using a constructed wetland
KOUKLÍKOVÁ, Etela
This bachelor thesis is focused on the determination of the efficiency of the nickel removal from wastewater using constructed wetlands. During 2015, wastewater from the vegetation wastewater treatment plant in the villageSlavošovice was analyzed. Nickel concentration in wastewater was determined by atomic absorption spectrometry. Samples of wastewater were taken eight times from six different parts of the wetland. The obtained results of the wastewater analysis I evaluated the degree of the nickel removal in the profile of the vegetation wastewater treatment plant. The analysis was conducted using an atomic absorption spectrometer Thermo Scientific iCE 3500. The characteristics of the analytical method were as follows: accuracy (97.64%), precision (3.53%), sensitivity (9 x 10-3 s.l/g), limit of detection (LOD = 0.161 ?g /l), limit of quantification (LOQ = 0.537 ?g/l), linear dynamic range (0,537 - 10 ?g/l) and correlation coefficient (0.9992). The concentration of nickel obtained from samples from the inflow zone differed by several tenths or units of ?g/l compared to the inflow concentration value. The nickel of concentration at the outflow from the system was decreased by units of ?g/l compared to the inflow. The gradual decrease of the concentration of nickel was observed for the samples taken from the profile of the constructed wetland vegetated bed. The obtained results document the sufficient efficiency of the nickel removal from municipal wastewater in Slavošovice constructed wetland. The outflowing water, guided to a nearby stream, contains lower concentrations of nickel in comparison with the raw wastewater. With respect to aquatic organisms, it is very important to reduce the concentration of nickel in treated wastewater. Actually, the nickel toxicity for aquatic organisms is much higher than for humans.
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LabVIEW drivers for resistor decade
Procházka, Matěj ; Čala, Martin (referee) ; Havlíková, Marie (advisor)
This bachelor's thesis deals with description resistance decade M63x and M64x from Meatest company. I described functions and possibilities of remote access. Further are described how it's developed instrument driver in LabVIEW. At the end is cited how I conduct with testing this driver.
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Study of influence of admixtures on electrochemical characteristics electrode materials for lithium-ion batteries
Nejedlý, Libor ; Jirák, Tibor (referee) ; Sedlaříková, Marie (advisor)
The bachelor project deals with new intercalation materials with admixtures for positive electrode of lithium-ion accumulators. Concretely, the project works with new preparation methods of electrode materials and compares them with long-established industrial process. For this purpose were used electrochemical measurements and structure analysis obtaining materials. The theoretical part of the project is devoted summary of electrochemical power sources, electrochemical reactions, recycling and future of Li-ion batteries. The practical part describes electrochemical methods, measurements and discusses achieved results.
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Influence of Mn ionts in nickel hydroxide on behavour electrodes
Cirkovský, Jaroslav ; Vrbický, Jiří (referee) ; Sedlaříková, Marie (advisor)
The aim of my diploma thesis was to explore the influence of manganese ions put into nickel nitrate structure. The attention was focused mainly on the stabilization of nickel nitrate a modification, which could not change into b modification. The theoretical part of my thesis focused on applied materials, kinds of acumulators, basic parameters of acumulators and the description of chosen methods of measurement employed. It contained the electrodeposition, the impedance spectroscopy and the cyclic voltammetry. The task of the experimental part was to measure the effect of manganese ions put into potassium hydroxide structure. Proportions of Ni (nickel nitrate) : Mn (manganese nitrate) 10:0, 7:3, 5:5, 6:1 and 6:4 were blended for the measurement. By means of the electrodeposition, there was a thin layer of nickel hydroxide with an admixture of manganese ions from nickel nitrate and manganese nitrate dilution put on the nickel plate. After the spread of the thin layer on the nickel plate, the measurement by the method of cyclic voltammetry followed. The next task consisted in trying to add KOH (potassium hydroxide) anionic and cationic surfactant into the dilution.
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Preparation and evaluation of metallic contacts for crystalline
Frodl, Miroslav ; Jandová, Kristýna (referee) ; Hladík, Jiří (advisor)
This work deals with the advanced methods of contact’s fabrication for monocrystalline solar cells and the appropriate methods for the analysis of their properties with a focus on the study and realization the contact’s structures with low contact and sheet resistance fabricated by galvanic and electroless processes. In the first part of the work is discussed the theory of solar cells and buried contacts and in the second part of the work is an evaluation of practical realization.
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