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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.
11

Analýza emisí polétavého prachu při provozu dopravních zařízení a návrh opatření pro eliminaci vlivu na životní prostředí. / Analysis of emissions of particulate matter during the traffic proposal of measures to eliminate the occurrence and impact on the environment.

JIRAŇ, Josef January 2013 (has links)
I dealt with the analysis of emissions of particulate matter during the traffic transport equipment in this work. I made measurements at five different locations with different pollution and various kind of transport. I wrote the measured values to the charts and I made assessment situation. I also made a proposal of measures to eliminate the occurrence and impact on the environment.
12

Vliv emisí prachových částic a pachových látek z intenzivního výkrmu drůbeže na životní prostředí v okolí chovu.

COUFAL, Marek January 2018 (has links)
This thesis is about evaluation of the influence of odorus substances and dust particles from intensive poultry farming to the environment. Measurement was done on a family farm near the forest in spring and autumn in 2017. The fattening of broilers is carried out there in four fattening halls with a total of 103,000 units. Poultry is fattened on the farm for 238 days during the whole calendar year after 7 batches. Sampling was carried out from one of these halls. The values obtained are ranged from 59 / m3 to 215 / m3 for odorous substances and particulate matter PM10 ranging from 0.061 mg to 0.0765 mg. PM2.5 dust particles showed values of 0.042 mg after 0.1535 mg. Evaluation of odorous substances was performed by the method of dynamic olfactometry according to the standard ČSN EN 13 725. The values obtained were ranged from 59 / m3 to 215 / m3. The range of production specific emissions was between 0.013828 and 0.298366 ( / / s). The PM10 particle emission production rate between 0,0000179 and 0,0001094 (mg / pc / year) and PM2,5 from 0,0000642 to 0,0001672 (mg / pc / year) was determined using the particulate measurement methodology. These data were compared with the relevant air pollution limits according to Annex No. 1 to the Act on Air Protection No.201 / 2012 Coll., Immission background in the locality and a dispersion study was prepared for them.
13

Cihelný prach vznikající při broušení pálených zdících tvarovek a možnosti jeho využití / Brick Dust Arising During Grinding of Burnt Brickwork and Possibilities of its Utilization

Kocmánek, Tomáš January 2020 (has links)
The diploma thesis focuses on the brick dust arising during grinding of burnt brickwork and the possibilities of its utilization. In the theoretical part origin and basic properties of brick dust is described. Some published results of research on the potential utilization of brick dust in various industries are presented here. Also proposal of utilization of brick dust in the ceramic industry is presented. In the practical part two ceramic raw materials and the two brick dust with different granulometry arising during grinding of burnt brickwork (made from these two ceramic raw materials) were selected. The effect of the addition of brick dust to the ceramic raw materials on the physical - mechanical properties of ceramic body after sintering was investigated.
14

Interakce prachu s UV zářením / Dust-UV interaction

Nouzák, Libor January 2012 (has links)
Title: Dust - UV interaction Author: Libor Nouzak Department: Department of Surface and Plasma Science Supervisor: RNDr. Jiri Pavlu, Ph.D. Supervisor's e-mail address: jiri.pavlu@mff.cuni.cz Abstract: Micrometer objects (dust grains) are an integral part of the universe. As other objects in the plasma, these dust grains charge to potencial close to the potencial of the plasmas (in this case, interplanetary plasma). In the universe, the photoelectric charging dust grain dominantes all other charging processes. In general, the resulting charge of dust grain is given by a balance of all processes, which haven't been mostly jet theoretically described. In our laboratory, we are simulating space conditions and measure resulting charge and his changes on a single separated dust grain. This work is partly focused to UV source application and to finishing its electronics, and partly on test measurements and model calculations, connected with newly built experiment (e.g., to estimate effects of backgound currents, surfaces, and the geometry of the dust trap electrodes). The work is finished by the first measurements of glass grain charge under electron bombardment with provisional detection optics. Obtained results are compared with previous measurements on the same type of dust grains. Key words: dust, dusty plasma,...
15

Experimentální studium teploty elektronů a iontů v impaktovém plazmatu / Experimental study of electron and ion temperatures in impact plasmas

Kočiščák, Samuel January 2021 (has links)
Title: Experimental study of electron and ion temperatures in impact plasmas Author: Samuel Kočiščák Department: Department of Surface and Plasma Science - DSPS Supervisor: doc. RNDr. Jiří Pavlů, Ph.D., DSPS Abstract: In-situ analysis of a hypervelocity grain impact is a complex discipline, making use of multiple physical phenomena. An important one, if not the most important one, being a dust impact ionisation. Future experiments could benefit substantially from better understanding of the phenomenon. The goal of this work was a study of the impact ionisation per-se, with the objective: to experimentally determine the effective temperatures of post-impact charged ejecta. Importance of this parameter is obvious, although different approaches scarcely ever report similar results. Our way was the analysis in a retarding potential analyzer. Firstly, large data set of laboratory data from dust accelerator was analyzed, secondly a Monte Carlo study of the results and the analyzer itself was performed. Lastly, recommendations for future in-situ experiments are provided based on our results. Keywords: impact plasmas cosmic dust impact ionization
16

Kontrolní systém základních technických požadavků pro výrobu u mikro a malých podniků dřevařského průmyslu

Roháčková, Michaela January 2017 (has links)
The purpose of this dissertation is to examine the issue of a job position as part of the working environment. It defines basic requirements and is based on the current view of the role of man who is the focal point for creating the working environment in manufacturing industries. The dissertation also deals with closely related occupational health and safety. As it primarily concentrates on the wood processing industry, the assessment of the working environment also examines the issues of fire safety and the ubiquitous wood dust. The purpose of the dissertation is also to create a control system for wood processing companies. The suggested control questionnaire follows its theoretical basis in the presented overview. The practical usability of the questionnaire is subsequently tested in an existing wood processing company. Major faults in areas under review can be identified by the evaluation of the questionnaire survey. On the basis of an evaluation of the current situation, practical measures for every category are suggested in a discussion; the employer can implement the measures to improve occupational health and safety of its employees.
17

Emise prašnosti při broušení tepelně modifikovaného buku

Železný, Antonín January 2017 (has links)
The thesis is focused on wood dust generated during sanding modified beech. The analysis concerns the characteristics and composition of this dust. The thesis addresses also the danger for human health exposed to the wood dust and its impact on the work environment. The theoretical part is focused on properties and biological effects of airborne dust on the human body as well as the thermal modification of wood. The experimental part was carried out on a test stand to simulate standard sanding. For our experiment three samples were selected, namely a modified beech at 180 °C, 200 °C and a native beech. In order to evaluate the incidence of wood dust, a methodology was designed to determine the representation of individual fractions of wood particles. Very fine particles (particles smaller than 100 micrometres) were subjected to microscopic and probabilistic analysis.
18

Magnetometrické a spektrometrické analýzy polétavého prachu z lokalit s emisním znečištěním ovzduší převážně z automobilové dopravy (Pražský okruh) a z průmyslu (poblíž ostravských hutí) s využitím meteorologických dat / Magnetometrical and spectrometrical analyses of fly ashes from the areas with emissonal air pollution mainly from automobile traffic (near Prague's D0 motorway) and from industry (near Ostrava's iron-mills) with a use of meteorological data

Hrušková, Gloria January 2018 (has links)
The content of analytical part of this thesis is the study of airborne dust samples collected in places with its higher concentration: by the Prague Ring (D0 motorway) and near the Ostrava's iron-mills. In both places, automobile transportation or industrial production are the primary sources of particulate matter emissions in the air. Received samples of PM1, PM2, PM10 a TSP filters were obtained by a standard air pollution monitoring procedure. This study examines the relationship between the magnetic parameters of the samples, their level of concentration of metals frequently present in emissions from these sources, the total mass of the dust fraction in the samples and the meteorological parameters (for Ostrava samples). The magnetic properties of the filters were investigated by magnetometric analyzes using a vibration sampling magnetometer. The concentrations of the metals were monitored by X-ray fluorescence spectrometer, the weight of parts of dust filtres was measured on laboratory scales.
19

Rizika chemických škodlivin v pracovním ovzduší kovovýroby, měření a hodnocení. / The hazards of harmful chemical substances in metal production environment, measuring and assessment.

GRUBEROVÁ, Michaela January 2009 (has links)
The target of the thesis was to evaluate the risk of chemical harmful substances and dust in the working air of metal production. Four research questions were asked: {\clqq}What harmful substances are fixed in the working environment of the metal production?`` {\clqq}Are the hygienic limits of chemical substances and dust in the working environment of metal production observed?``, {\clqq}What measures were taken by the employer for the purpose of the health protection of employees?`` and {\clqq}Are the measures taken by the employer for the purpose of the health protection of employees effective?`` The thesis was treated as qualitative research. The followed file consisted of three South Bohemian companies dealing with metal production. The method of the direct, non participating and clear observation was applied for the data collection, moreover the study of documents {--} testing reports. The secondary analysis of data was performed. The results of measuring were compared with the hygienic limits fixed by the Directive of government No. 361/2007 Coll.. The evaluated professions were divided in categories pursuant the Directive No. 432/2003 Coll. In the working air of metal production, the concentration of the total dust, chromium, hexavalent chromium, carbon monoxide and ozone were followed. The last measuring in the monitored workshops proved that the hygienic limits were observed, except for two cases when the highest acceptable concentration determined for chromium and the chromium (II,III) compounds as Cr, and of the hygienic limit for welding fumes were exceeded. The most important protective measure applied by the employers on their workplaces was the reconstruction of air-conditioning, or installation of local exhausting. In view of the gradual decrease of the harmful substance in the working air in connection to the taken measures may be stated that the given measures were effective. The hypothesis {\clqq}Modernisation of operations in metal production improves the working environment of employees and in the modern operations no above-the-limit values of the most monitored harmful substances were found out. ``
20

Vliv prachových částic na kluzný kontakt / Influence of dust particles on sliding contact

Píšala, Jan January 2019 (has links)
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.

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