This thesis deals with the sliding contact of electrical machines and its diagnostic methods. Namely, the dust-particles method for assessing the length decrease of brushes is deeply described. Then, usage of the method in industry is described. The comparison of accuracy between manual version and new automated version of the method using computer analysis is presented. The final section is devoted to the practical verification of the new automated version which was developed especially for large machines. Measurements were performed on a small machine.

Master's thesis "effect of dust particles on sliding electrical contact" summarizes the sliding contact theory and praxe in rotating electrical machines. The principle of brush machines is described and the working environments are defined. The individual components of the sliding contact and reasons of their degradation are described in detail. Emphasis is placed on the influence of foreign particles, which can be assessed in practice by the method of dust particles. Furthermore, these theoretical knowledge was used in the practical assessment of the technical condition of various machines, as well as the called method. One set of brushes for the traction motor of the locomotive T47.0 was also experimentally innovated.

This thesis is devoted to the topic of kluzný kontakt and its diagnostic, especially to the type of diagnostic using the method of -- of dust particles. The author presents an example of applying this method and deals with the topic of development of a laboratory template that will give access to bigger variability in studying this method.

Dust is an almost ubiquitous component of the cosmic plasma (e.g., planetary and cometary magnetospheres, the heliosphere, the interstellar medium, supernova shells). However, it can be also frequently encountered in industrial applications as a principal agent in material treatments, or as an undesirable ingredient in a production of microelectronic components, or in fusion devices. Since dust particles are one of the main elements of interest in the solar system (e.g., Earth, Jovian and Saturnian systems) and in the interstellar medium, there is a number of missions (e.g., ROSETTA, Cassini) that provided investigations of the properties and global dynamics of charged dust grains. In these environments, the relevant charging processes are interactions with electrons and ions of the solar wind and photoemission by solar UV radiation that often dominates. However, in-site investigations of such processes are difficult because several processes act in accord. The present thesis studies charging processes in laboratory settings where these processes can be investigated separately. In the first series of experiments focused on applications in the lunar or planetary surroundings, a single (charged) dust grain is stored in an electrodynamic trap and expose to electron and/or ion beams with variable energies and...