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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Elektrochemická depozice křemíku z organických sloučenin / Electrochemical deposition of silicone from organic solvents

Kaválek, Ondřej January 2010 (has links)
The diploma thesis deals with researching electrodeposition of silicon in anhydrous solutions. As electrolyte was used EC:DMC (1:1) with (C2H5)4NBF4, LiPF6 and LiClO4. Research was measured by cyclic voltammetry and XRD.
22

Vícekanálové zařízení pro elektrochemické měření ze senzorového pole / Multichannel instrumentation for electrochemical measurement from sensor array

Žák, Jaromír January 2010 (has links)
The work deals with n-channel system enabling many sample analysis at sort time from sensor array using electrochemical methods. The 8x12 sensor arrays are formed from 3 electrodes system created on PCB which can be used for heavy metal analysis and toxic substances determination. The control unit switches each 3 electrode sensor to 8 channel precise potentiostat which was designed for electrochemical analysis with current sensitivity below 10 pA. The potentiostat can synchronize with control unit. Developed system is able to measure up to eight single inputs and may be simply converted to measure other nonchemical values. Measured data will be sent to user-friendly application in computer and analyzed or saved consequently.
23

Optimalizace struktury kompozitních materiálů na bázi uhlíku / Optimalisation of coposite materials for civil engineering

Kazda, Tomáš January 2011 (has links)
This work is focused on optimalisation of coposite materials for civil engineering. In the theoretical part of the project is introduction of the composite materials and materials which are used for their production. There are also concerned their properties and possible application areas. In conclusion of theoretical part this project is a summary of the possible use of composite materials. The practical part compares the characteristics of the different types of composites made in terms of conductivity and the rate of corrosion.
24

Sensor pro analýzu kapalin / Liquid analysis sensor

Hanus, Martin January 2011 (has links)
This thesis deals with the mixing of liquids issues. The simulation of structure for mixing of liquids and evaluation of parametres which have most significant influence on mixing of liquids was made with help of COMSOL programm. In the next section of thesis the quality of electrodes used for cyclic voltammetry made on LTCC by thick layer technology was determined. In the end of this thesis the 3D structure for mixing of liquids was made. The quality of mixing was controlled by cyclic voltammetry.
25

Elektrochemické senzory s 3-D strukturou elektrod / The electrochemical sensors with 3-D structure of electrodes

Štekovič, Michal January 2012 (has links)
Miniature electrochemical sensors can be produced by thick-film technology. The optimal properties of thick-film electrode system, the production technology optimization of thick-film sensors and the adjustment of optimal technological properties are main problems of sensor design. An area of working electrode and an electrode topology design is the important parts in design of electrode system optimization. The rules for optimization of electrode systems in classical electrochemistry exist. The design of standard thick-film electrode construction is limited (2-D construction, substrate dimensions, resolution, paste parameters …). Therefore rules for classical electrode systems cannot be used fully in this case and larger electrode area can be making by 3D structure only. One of resolutions is unconventional method. The increase of working electrode surface by unconventional method – ball and wire bonding is discussed in this work.
26

Optické stanovení stavu nabití průtokových vanadových článků / Optical determination of the state of charge of vanadium flow battery cells

Šacl, Vojtěch January 2015 (has links)
The investigated subject for this diploma thesis is getting know properties of the vanadium redox battery (VRB), especially electrolyte. Specialization is applied to the state of charge of this cell and its measurements using the optical methods. Upon different state of charge is changed oxidation number of vanadium and resultant color of the electrolyte. Using spectrofotometry method that characteristic property is undergone measurement. The basic thing was learning to handle a measurement system. The first practical measurement was executed on example foils. Upon measurement of vanadium cell there was obtained the values of absorbation, which they were used for determination of state of charge.
27

Stanovení sulfamethizolu pomocí uhlíkových pastových elektrod / Determination of sulfamethizole using carbon paste electrodes

Mikeš, Miroslav January 2012 (has links)
The proposed Thesis deals with the electrochemical behavior of sulfamethizole on carbon paste electrodes. Sulfamethizole is a sulfonamide antibiotic effective against a number of gram-positive and gram-negative bacteria. In human medicine, the most frequent application is for the treatment of urinary tract. In veterinary medicine, it is used for the and preventive treatment of both aquatic and terrestic animals. Due to the wide utilization and low metabolization, it also presents an environmental burden. The development of quick and sensitive methods for the determination in both biological and pharmaceutical matrices is therefore important. This Thesis deals with the search of optimum conditions for differential pulse voltammetric determination of sulfamethizole in tablets Micturol sedante, used for the treatment of urinary tract. The method uses Britton-Robinson (B-R) buffer pH 7 and reaches detection limit 0,39 µmol·l-1 . Results of the method complied with the manufacturer's information and with the results of spectrophotometric determination. In the other part of the work, conditions for the determination of sulfamethizole determination in urine samples. Fonund conditions were: Lichrospher® RP-18, 100 (5 µm), 125×4 mm, (LichroCART) column, mobile phase B-R buffer pH 3 : methanol (7:3, v/v) and...
28

Elektrochemická oxidace žlučových kyselin na elektrodách na bázi uhlíku. Možnosti využití v elektroanalýze. / Electrochemical oxidation of Bile Acids on Carbon Based Electrodes. The Possible Use in Electroanalysis.

Klouda, Jan January 2015 (has links)
The goal of this master's thesis was to examine the possibility of oxidation of seven selected bile acids and evaluate whether such processes are suitable for analytical purposes. The secondary goal was to describe the oxidation products of bile acid electrolysis. The experiments were carried out in a non-aqueous medium of acetonitrile and in a mixed medium of acetonitrile:water using linear sweep and cyclic voltammetry. The working electrode materials employed for voltammetric experiments were: highly oriented pyrolytic graphite, -cyclodextrin modified glassy carbon and boron doped diamond. Preparative electrolysis was carried out on a platinum electrode in the non-aqueous medium of acetonitrile. Experiments have shown that neither the highly oriented pyrolytic graphite electrode nor the -cyclodextrin modified glassy carbon electrode are suitable for analytical purposes under conditions used. The results achieved on the boron doped diamond electrode, on the other hand, have not yet been described in the literature. Primary bile acids cholic and chenodeoxycholic were oxidized at approximately 0.5 V lower potential in the mixed medium of acetonitrile:water than in the papers using carbon electrodes published until now. Products of oxidation on the platinum electrode were separated by TLC and...
29

Morfologie modelových katalyzátorů v prostředí elektrolytu / Morphology of model catalysts in electrolyte environment

Keresteš, Jiří January 2016 (has links)
The aim of this thesis is preparation of inverse model catalyst CeOx/Pt(111) and its investigation using combination of surface physics methods and electrochemistry. New electrochemical cell was designed and built for electrochemical experiments. CeOx/Pt(111) samples were prepared and studied in UHV using STM and XPS methods. After that, samples were transferred to the electrolyte environment and studied by means of cyclic voltammetry and AFM. For high surface coverage of CeOx, new reaction was observed. We have identified this reaction as a combination of the reduction of cerium(IV) oxide by interaction with hydrogen adsorbed on the Pt(111) surface and oxidation of cerium(III) oxide by dissociative adsorption of water molecules. Powered by TCPDF (www.tcpdf.org)
30

Voltametrické stanovení dinitronaftalenů pomocí krystalové stříbrné amalgámové elektrody / Voltammetric Determination of Dinitronaphthalenes Using Single Crystal Silver Amalgam Electrode

Tvrdíková, Jana January 2011 (has links)
Voltammetric methods for determination of 1,3-dinitronaphthalene (1,3-DNN), 1,5-dinitronaphthalene (1,5-DNN) and 1,8-dinitronaphthalene (1,8-DNN) using DC voltammetry (DCV) and differential pulse voltammetry (DPV) at novel single crystal silver amalgam electrode (CAgAE) were developed in this work. Developed methods may be used for determination of 1,3-DNN within a concentration range 2 - 10 μmol.L-1 with LoQ 2 μmol.L-1 using DCV and 1 - 100 μmol.L-1 with LoQ 1 μmol.L-1 by DPV; 1,5-DNN wihin a concentration range 2 - 10 μmol.L-1 with LoQ 2 μmol.L-1 using DCV and 1 - 10 μmol.L-1 with LoQ 1 μmol.L-1 by DPV and 1,8-DNN within a concentration range 2 - 10 μmol.L-1 with LoQ 2 μmol.L-1 using DCV and 0,3 - 1 μmol.L-1 with LoQ 0,3 μmol.L-1 by DPV. An attepmt to decrease LoQ by adsorptive stripping differential pulse voltammetry was not successful. Process of electrochemical reduction of selected dinitronaphthalenes on the working electrode was also studied by cyclic voltammetry. This work verified the use of CAgAE as alternative electrode material to mercury electrodes for determination of electrochemically reducible organic compounds in aqueous-methanolic media. Small dimensions of the CAgAE are the main advantages which predetermine its use in voltammetric microvolume batch analysis and amperometric detection in...

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