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3D-printed Electrodes with Nearly Ideal Charge Transfer Characteristics
Vaněčková, Eva ; Sebechlebská, Táňa ; Kolivoška, Viliam
3D printing is an outstanding manufacturing tool for prototyping customized designs at reduced time and costs, having found applications in fields such as medicine or the automotive industry. The development of printable electrically conductive composite materials brought a revolution to electrochemistry, with 3D-printed electrodes being intensively studied from the viewpoint of\nanalytical performance and stability. However, it is often reported that 3D-printed electrodes have poor charge transfer characteristics, typically due to limited exposure of the electrically conductive phase at the composite surface to the surrounding solution. In this work, we devise and apply simple electrochemical activation procedures that lead to a significant improvement of charge transfer characteristics of 3D printed electrodes.
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Simulation of earthing system resistance measurement
Pirochta, Josef ; Topolánek, David (referee) ; Vyčítal, Václav (advisor)
In this bachelor thesis, the effect of different soil models and random wire placed underground on the results of earth resistance measurements using the 4-pole method was investigated. To determine this influence, simulations were performed in Ansys Electronics software, in which different soil models (with local inhomogeneity, horizontally divided soil and soil divided at an angle) were created. In these models, the measured earth was placed together with the measured random wire and its resistance was determined by simulating the measurements and with respect to the distant ground. The effect of the different soil models on the accuracy of the measurements was determined from the differences in the resistance of the earth random wire obtained by measurement and with respect to the distant ground. It was found by simulations that, of all the variants investigated, performing measurements in the presence of different soil models and a random wire can lead to a measurement error of up to 7,2 %.
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Thick-film sensors for heavy metals detection
Gajdoš, Libor ; Majzlíková, Petra (referee) ; Prášek, Jan (advisor)
This project describes the possibilities of heavy metals detections in solutions using differential pulse voltammetry with tree-electrode electrochemical thick-film sensors. In the theoretical part, the thick-film technology is described as well as thick-film pastes’ types and compositions, followed by introduction to electrochemistry and electro-analytical methods of measurement. This project also describes the three measured heavy metals – cadmium, lead and copper. In the practical part, heavy metals’ ions detection in solutions using carbon working electrode and determination of the detection limit and sensitivity are described and discussed. Finally the evaluation of obtained results and results comparison to hygienic limits are included.
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Optical levitation of dielectric objects in an external electric field
Zemánková, Tereza ; Flajšmanová,, Jana (referee) ; Svak, Vojtěch (advisor)
The bachelor's thesis deals with the optical levitation of a dielectric microparticle in vacuum and its displacement by an external electric field. The theoretical part mathematically describes the laser beam, in which particles are stably trapped. Subsequently, the principles of optical trapping, particle confinement and the most common experimental geometries of optical traps, e.g. counter-propagating beams, optical levitation and optical tweezers, are introduced. Because the trapped particle behaves very similarly to a harmonic oscillator excited by white noise, at the end of the theoretical part there are presented the equations of motion of the particle and their solutions for various cases, including Langevin equation of motion. The experimental part describes two experimental setups, in the assembly of which I participated. In the last part results of two main experiments are presented - displacement of the trapped particle by an external electric field, including determination of its charge, driving the particle by controlled white noise and determination of the effective temperature of stochastic motion of the particle.
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Skin resist and psycho-galvanic reflex
Trávníčková, Hana ; Bubník, Karel (referee) ; Chmelař, Milan (advisor)
The aim of this bachelor’s thesis was to clarify the phenomenon called psychogalvanic reflex, describe mechanism of its origin, its affects and use in practice. It analyzes the structure of the skin and its properties in terms of conducting electrical current, describes the phenomenon itself and discusses the conditions for its measurement. The practical part is devoted to the concept and realization of a simple psychogalvanometer. This device is connected with PC and acquired signal is processed by LabView.
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Polarographic analysis of water
Klečka, Tomáš ; Rozman, Jiří (referee) ; Čížek, Martin (advisor)
This bachelor's project creates the necessary theoretical foundation of polarography and voltametry in the first part, which is needed to successful measurement using these technics. In the second part there is realized measurement with anodic stripping voltametry and accomplished evaluation in MATLAB. Finally there is example of procedure for laboratory task with polarograph.
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Electrochemical Characterization of Nanostructured Surfaces Modified by Substancies with Thiol Bound
Urbánková, Kateřina ; Kynclová, Hana (referee) ; Hrdý, Radim (advisor)
This master thesis deals with nanotechnology, nanoparticles and nanostructured surfaces, electrochemical methods, especially voltammetry, cyclic voltammetry, electrochemical impedance spectroscopy and contact angle measurement. One part is focused on electrodes primarily nanostructured and modified by substancies with thiol bound. Tutorial for preparation of gold nanostructured electrods is introduced in practical section including SEM photos of electrode surface. Nanostructured and bare gold electrodes were modified by 11-mercaptoundecanoic acid, streptavidin, glycine and biotin and measured by cyclic voltammetry, electrochemical impedance spectroscopy and contact angle.
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Analysis of EMG Signal for Prosthetic hand based on Fuzzy Logic Technique
Ollé, Tamás ; Kolářová, Jana (referee) ; Pathak, Pawan Kumar (advisor)
Lidská ruka je koncový orgán horní končetiny, který slouží k důležité funkci uchopení, stejně jako důležitý orgán pro vnímání a komunikaci. Je to úžasný příklad o tom, jak komplexní mechanismus může být implementovaný, schopný chápat velice komplexní a užitečné úkoly používáním velmi efektivní kombinace mechanismů, snímání a řídicích funkcí. Elektromyogram (EMG) byl původně vyvinutý pro vyšetrování svalnatého nepořádku. Klinické aplikace se brzo rozšířila, nejpozoruhodněji ve výzkumu epilepsii a nakonec se stal populární po zavedení protéz, specificky tělem poháněných protéz. EMG nahrávání je použito pro studování funkčního stavu svalu během různých pohybů. Cílem tohoto projektu je vyvinutí elektromyogramové (EMG) metody třídění, která bude pomáhat v aplikacích jako systém pracující v reálném čase. První část tohoto projektu bylo získávání informací. Údaje reálného času byly zaznamenaný pomocí EMG monitorovacího systému (BIOPAC) a kompletní datová sada různých osob byl zaznamena. Tyto EMG data byly konvertované ze souboru ASCII do čitelné formy pro MATLAB. Druhou částí projektu byla extrakce vlastností. Pět tradičních parametrických rysů bylo vypočítáno, jmenovitě Integrovaný EMG (IEMG), variance (VAR), Zero Crossing (ZC), Slope Sign Changes (SSC) a Vlnová délka (WL). Třetí část projektu byla klasifikace EMG vzorů s použitím fuzzy logiky. Výsledky jsou docela slibné.
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