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Optimization of spectral segmentation for electron microscopes
No full textThis bachelor's thesis focuses on the development of a new method for optimal placement of EDS (Energy Dispersive Spectroscopy) measurement points based on BSE (Backscattered Electron) images in SEM (Scanning Electron Microscopy) to improve the efficiency and accuracy of elemental analysis. The proposed segmentation-based method eliminates the issues of existing approaches, such as mixed signals at material interfaces and inadequate point distribution for crystalline structures, through edge exclusion, adaptive point placement, and dynamic point allocation to segments. The results confirm the method's potential for integration into automated mineralogical systems, thereby contributing to more efficient material analysis
Analysis of hazardous elements in aquatic ecosystems by the diffusion gradient in thin film (DGT) technique
No full textThis bachelor thesis is focused on the possibilities of using the diffusion gradient in thin films (DGT) technique for determination of risk elements, specifically cadmium, lead and chromium. The theoretical part describes these specific risk elements and their impact on the environment and humans. Furthermore, the diffusion gradient in thin films technique is described, including its principle and use and the commonly used types of gels. Last but not least the theoretical part also briefly describes the atomic absorption spectrometry technique, which is one of the methods of elemental analysis commonly used in the final step of the process of determining metals after applying the DGT technique. In the experimental part, tests of the DGT technique as in situ sampling technique for the determination of Cd, Pb and Cr in aqueous environments were carried out under laboratory conditions, starting from the step of preparing agarose-based gels
Analysis of substrate mixing for tap root planting material using DEM simulations
No full textThis diploma thesis focuses on the analysis of substrate mixing for planting stock using the Discrete Element Method (DEM). Based on experimental measurements, the physical properties of the substrate were determined, including bulk density, angle of repose, friction coefficients, and behavior under uniaxial compression. A calibrated model was created in Altair EDEM using particles of various shapes to better reflect the behavior of real substrate components. The simulation was conducted using the geometry of the Urbinati MC1120–C mixer and included evaluation of mixing quality using the Lacey mixing index as well as an analysis of the forces acting on the moving parts of the device
The effect of the inlet velocity on the flow in the interior of the hydrocyclone
No full textThis thesis focuses on the effect of inlet velocity on the internal flow in a hydrocyclone using numerical simulations. CFD modelling was used to analyse pressure distribution, vortex structure development, and particle motion under varying inlet conditions. Simulations were carried out using an advanced turbulence model and discrete particle tracking. The results show that higher inlet velocities increase tangential velocity and improve separation efficiency. The findings contribute to the optimization of hydrocyclone design and operational performance
Crawler chassis for mobile chipper
No full textThis bachelor's thesis focuses on the design of the central section of a mobile tracked undercarriage with variable track width, intended for a chipper with hydraulic drive. The aim is to develop a mechanism that allows adjustment of the track width to enhance the machine's stability and mobility in challenging terrain. The undercarriage is powered by rotary hydraulic motors, while the width adjustment is achieved using a pair of linear hydraulic actuators. The thesis includes a theoretical analysis of tracked undercarriages and their comparison with wheeled systems. It also presents a custom design solution based on the specific requirements of the chipper and the company, along with calculations of key parameters such as hydraulic system performance and structural strength. The outcome is a conceptual design of the central section of a tracked undercarriage with variable width, accompanied by technical drawings, dimensional, force and power calculations, and a specification of the selected components
Optimization of the plasma cutting process
No full textThe bachelor thesis focuses on optimizing the plasma cutting process of S235JR structural steel. The aim of the thesis was to analyze the influence of various cutting parameters, specifically cutting current and cutting speed, on the final quality of the cut pieces. As part of the experiment, three sets of samples with different combinations of these parameters were prepared, and the quality of the cut surfaces was evaluated according to the ČSN EN ISO 9013 standard. The basic geometric characteristics of the cut pieces were monitored, such as the perpendicularity of the cut edges, surface roughness, dimensional deviations, and the accuracy of internal and external shape elements. Special attention was also paid to the heat-affected zone , where the width and hardness were measured in accordance with the requirements of ČSN EN 1090-2. The results showed that in terms of geometric accuracy, the best values were achieved at a current of 35 A, while the most suitable sample overall was C40 with a current of 40 A and a speed of 635 mm/min, which showed stable quality in all evaluated parameters. The work provides practical recommendations for the effective setting of plasma cutting when cutting sheets with a thickness of up to 4 mm
Detection of Alcohol Addiction from Brain Signals
No full textPoruchou způsobenou užíváním alkoholu (AUD) trpí mnoho lidí na celém světě. Stávající metody zjišťování závislosti na alkoholu se potýkají s problémy. Tato práce zkoumá vylepšený algoritmus detekce založený na datech elektroencefalogramu (EEG) a technikách strojového učení (ML). Tento výzkum využívá soukromou datovou sadu UTP-USM, která obsahuje záznamy EEG od osob s AUD a bez AUD, a to v podmínkách otevřených očí (EO) a zavřených očí (EC). Pro zachycení relevantní mozkové aktivity je extrahováno více funkcí. Při výběru příznaků jsou použity statistické metody t-testu a řazení LDA. Trénování a vyhodnocování modelu se provádí pomocí křížové validace. Klasifikátory vykazují slibné výsledky pro stav EC. Výkonnost je však nižší pro stav EO, pravděpodobně v důsledku zvýšeného šumu signálu. Tato zjištění naznačují, že ML modely založené na EEG mají potenciál pro detekci subjektů s AUD, a zdůrazňují důležitost předzpracování signálu a výběru příznaků
Simultaneous LIBS detection of nanoparticle markers based on yttrium and lanhanoides in imunocomplexes
No full textThis bachelor's thesis investigates the use of laser-induced breakdown spectroscopy (LIBS) for the simultaneous detection of silver, lutetium, and yttrium nanoparticles. The aim was to analyze prepared individual, binary, and ternary mixtures of nanoparticles and assess whether the nanoparticles mutually influence each other. The experimental work focused on the preparation and LIBS analysis of samples of different types of nanoparticles and their mixtures. The first part of the experiment suggested a possible enhancement of the LIBS signal due to the mutual interaction of nanoparticles in binary and ternary mixtures. However, this phenomenon was refuted by the second part of the experiment. It was demonstrated that the LIBS method enables the detection and differentiation of selected nanoparticles with high precision in mixtures, and no significant mutual influences of different types of nanoparticles were observed at lower concentration ranges of mixtures. The obtained results suggest the suitability of selected types of nanoparticles for their use as markers in indirect multiplex analysis of biomarkers in immunoassays with LIBS detection
Simulation of Animal Evolution
No full textTáto bakalárska práca sa zameriava na evolúciu zjednodušených živočíchov v kontexte meniaceho sa sveta. Cieľom tejto práce je vytvoriť simuláciu populácií živočíchov a sledovať ich genetické adaptácie na prostredie. Dôraz je tiež kladený na zmeny, ktoré sprevádzajú posuny v prostredí živočíchov, ako napríklad zmeny celkovej teploty, prístupu k vode a iné environmentálne zmeny a katastrofy. Výsledkom tejto bakalárskej práce je 2D simulácia v hernom engíne Godot a analýza zistení zo simulácie
Application of fuzzy logic for creating a cryptocurrency portfolio
No full textThe thesis deals with the application of fuzzy logic for the creation of a cryptocurrency portfolio. The main objective of the thesis is to propose a solution to assist beginner or less advanced investors with decision making in the dynamically changing cryptocurrency market. The resulting model is able to determine, based on defined criteria, whether it is appropriate to invest at a given moment or not, and help investors with the structure of their portfolio. To ensure functionality, testing is also carried out using historical data. The solution is based on the theoretical foundations of fuzzy logic