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Nickel silicides layer by electron beam melting of electro deposited layer
Petr, Jiří ; Pantělejev, Libor (referee) ; Jan, Vít (advisor)
This master’s thesis deals with the possibility of creating a compact nickel-silicide layer on austenitic substrates. The theoretical part describes a variety of surface treatments, silicide division, and basic principles of electron beam. The experimental part contains a description of used experimental methods for evaluation of samples, creation of Ni-Si coating using electroplating, and the parameters of electron beam used for melting the sample coating. The last part is devoted to structural evaluation of the sample coating and its microhardness.
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Leachability of Cu, Ni and Co from alkali-activated matrices
Janíčková, Vlasta ; Kalina, Lukáš (referee) ; Koplík, Jan (advisor)
The work deals with the determination and comparison of leaching of heavy metals from two types of alkali activated systems based on blast furnace slag and high-temperature fly ash. These systems are capable in their structure encapsulate heavy metals, toxic substances or radioactive substances, which can be harmful for the environment. The aim of this work is to prepare a mixture with acceptable mechanical properties. Leachibility from matrix was tested according to ČSN EN 12457–4, followed by analyses Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Structure of matrix was analysed using Scanning electron microscope (SEM).
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Photochemical generation of volatile species of nickel for analytical atomic spectrometry methods
Šoukal, Jakub ; Musil, Stanislav (advisor) ; Kratzer, Jan (referee)
This thesis deals with optimization of conditions of photochemical generation of volatile species of nickel for atomic absorption spectrometry. The volatile species of nickel were generated in the flow arrangement, when sample was injected to a stream of a reaction medium. Either formic acid was used as the reaction medium or formic acid with the addition of formate anions. Two types of a generator were tested, a generator with a PTFE tube wrapped around a mercury UV lamp and a high efficiency generator with an inside channel. At the same time, two types of a gas-liquid separator were tested. Diffusion flame was used as an atomizer due to its high robustness. Quartz atomizer didn't provide higher sensitivity and measurements had worse repeatability. All the parameters affecting atomization in the diffusion flame were optimized (flow rates and composition of gases, observation height). In the next section, conditions of generation (irradiation time, HCOOH concentration, addition of formate anions) were optimized. Interferences of inorganic acids in photochemical generation were investigated as well. It was found out that the generator with the inside channel provided slightly higher sensitivity and thus generation efficiency than the generator with the PTFE tube wrapped around. Transmission of...
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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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