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The Possible Assessments of Unprofessional Exposures of Low Frequency Noise
Potužníková, Dana ; Fiala, Zdeněk (advisor) ; Bencko, Vladimír (referee) ; Argalášová, Ĺubica (referee)
v anglickém jazyce The possible assessments of unprofessional exposures of low frequency noise Introduction: Along with technical development, the number of sources of low frequency noise increases in the human environment and the number of complaints from people exposed to noise from these sources increases as well. The statutory limit for non-professional exposure to low frequency noise has not yet been established (due to the limited amount of data on low frequency noise exposure risks) in the EU countries (USA) and no WHO recommendations have been issued in this area. For these reasons, the hygienic limit for municipal/non-professional exposure to low frequency noise was not specified in the Czech Republic. Objecticve: The present dissertation thesis was to investigate whether the short-term experimental exposure to low frequency noise with the tonic component induces significant changes in the circadian rhythm of cortisol and alpha-amylase in saliva in the experimental set of volunteers. Saliva is a biological material that allows low-invasiveness collection. The work was supposed to assess whether possible changes could be used as objective indicators of the presence of the stress response to the noise exposure. Material and metods: An experimental study was conducted on a set of 100...
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The purpose of design for hand tools
Remeš, David ; Fiala, Zdeněk (referee) ; Kalivoda, Milan (advisor)
This thesis deals with the effect of the design on hand tools. In the first theoretical part of this thesis, individual manual operations carried out during manufacturing are being further analyzed. The next part then focuses on the individual aspects of the product design and its influence on the hand tools. Followed by the processing of achieved parameters in handwork. The experimental part of this thesis deals with adjustments of the tap wrench´s handles made for manual cutting of internal threads. The utilization of the material when selecting a semi-finished product from blanks as well as the evaluation of the manufacturing in this way itself are also closely described in this part.
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Determining the best cutting tool for reaming the piston hole in Bosch Diesel company
Rauscher, Tomáš ; Jaroš, Aleš (referee) ; Fiala, Zdeněk (advisor)
The main goal of this diploma thesis is to increase cost savings on cutting tools, which are used to ream piston hole inside the housing of CP3 diesel pump made by Bosch Diesel s. r. o. Diploma thesis is divided into a theoretical description of the issue, which is initial knowledge for machining tests, and experimental part, whose task it is to find a suitable reamer for this technological operation. Cost savings will be achieved by selecting suitable tool instead of the serial tool that has been used so far.
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Factors affecting the quality of machined surfaces after milling operation
Černý, Libor ; Jaroš, Aleš (referee) ; Fiala, Zdeněk (advisor)
This diploma thesis deals with the final quality of the surface under variable working conditions during milling. The first part deals with the definition of qualitative parameters describing surface properties. This is followed by a brief description of the cutting resistance measurements. The thesis is complemented by experimental verification using front milling and its evaluation. The aim of the experiment is to determine the dependence of the surface quality and the size of cutting resistors under the variable working conditions of the machine that do not make a common part of the manufacturing processes.
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Prediction of suitable cutting conditions for machining of main steels
Beneš, Ondřej ; Fiala, Zdeněk (referee) ; Jaroš, Aleš (advisor)
In this thesis is described machining of barrel steels and determination of the most suitable cutting conditions for this process. In the theoretical part was characterized cutting process and explained problems of VBD wear, chip formation and roughness of the surface. There were also explained most common cutting materials and in the last part were described CVD and PVD coating methods. In the experimental part was measured force load during turning. There was also tested eight carbide cutting inserts from SECO TOOLS. During the tests were measured additional surface roughness values and taken chip samples as well. From the evaluated load force data were determined optimized cutting conditions for machining barrel steels and most suitable type of cutting insert.
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The influence of process fluid on the machining cycle
Ertl, Roman ; Fiala, Zdeněk (referee) ; Kalivoda, Milan (advisor)
The bachelor’s thesis focuses on literature search of problems of process fluids in the machining cycle. The aim of the thesis is to describe the properties of metalworking fluids and their distribution. Subsequently, the requirements for metalworking fluids from different angles of view are described. Process infuences are also discussed in detail on aspects such as temperature, wear, tool durability, etc. Another aim of the thesis is the feeding of process fluid into the machine’s working space and alternatives to process fluids, where MQL and dry machining are included. Great emphasis is placed on protecting the environment and the influence of liquids on the health of the machine operator. Subsequently, the basic maintenance of metalworking fluid sis described, starting with the creation of a new concentrate until their disposal.
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Threading operations in the building industry
Čech, Ondřej ; Fiala, Zdeněk (referee) ; Kalivoda, Milan (advisor)
The aim of this bachelor thesis is the sumarization of common threads and thread joints used in construction industry complemented with illustrations of actual joints. On construction thread cutting possibilities, more precisely situations, where there is no possibility to use stanionary placed machinery. Mechanical engineering machinery overwiev. Technological regime of selected thread joints. This thesis is supplemented with description of specific machining and thread cutting work on heavy-duty part of hydropower plant.
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Thread manufacturing in thin-walled mounting brackets
Malušek, Radek ; Fiala, Zdeněk (referee) ; Kalivoda, Milan (advisor)
The objective of this bachelor thesis is partition of the mounting brackets. It is especially of a thin-walled mounting bracket, where it is necessary to make a thread with the required bearing capacity. There has been thoroughly analyzed technologies of welding nuts, pressing nuts, riveting nuts and thermal drilling. The technological process for hinge trapeze sheet metal production is designed.
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Kinetics of selected substances in dermal exposure (Polycyclic aromatic hydrocarbons)
Kotingová, Lenka ; Fiala, Zdeněk (advisor) ; Bencko, Vladimír (referee) ; Čegan, Alexander (referee)
Kinetics of selected substances in dermal exposure (polycyclic aromatic hydrocarbons) Skin is one of the largest human body organs and its proper functioning is vital for human body. Dermal exposure represents one of the most important pathways of exogenous substances into the body. Data on kinetics of transdermal absorption of polycyclic aromatic hydrocarbons (PAH) have been yet so far insufficient. Present estimates of health risks level connected to dermal exposure to PAHs, are loaded with great deal of uncertainty. The aim of the dissertation thesis was employment and validation of appropriate testing method of transdermal absorption of substances in vitro and the use of this method to obtain new findings on the influence of concentration, dissolvent and form of application, on the measure of dermal absorption of selected PAH representatives. For the testing of transdermal absorption of substances in vitro, the method using static Franz vertical diffusion cell was chosen. As an absorption membrane, full leather of rear surface of the auricle of a domestic pig was used. Content of analytes in samples of receptor fluid was analyzed by gas chromatography with mass spectrometry (GC-MS) and by high performance liquid chromatography with fluorescence detection (HPLC), for which a new methods was developed and...
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Health risk assessment of chemical substances from removing of old environmental loads
Pelikánová, Denisa ; Fiala, Zdeněk (advisor) ; Dohnal, Karel (referee) ; Hrubá, Drahoslava (referee)
Health risk assessment of chemical substances from removing of old environmental loads Introduction. Hazardous wastes from refineries stored in lagoons are old environmental loads. One way of remediation is to extract and process this waste to an alternative fuel. Emissions of harmful substances released into the atmosphere during extraction and processing of waste can negatively affect the health of exposed persons. Aim of this study was to evaluate the potential level of health risks from remediation of old environmental loads based on the detected concentration levels of selected substances in the air and to build a view of potential health risk stratification in the wider area. Methods. Among the contaminants were monitored sulphur dioxide, toluene, hydrogen sulphide and 16 representatives of PAHs (acenaphthene, acenaphtylene, anthracene, benz[a]anthracene, dibenz(ah)anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[ghi]perylene, benzo[a]pyrene, fluoranthene, fluorene, chrysene, indeno[1,2,3-cd]pyrene, naphthalene phenanthrene, and pyrene). For that purpose was used combination of air pollutant concentrations and the dispersion model of substances in environment. The monitoring of contaminants was realized in the place of old environmental loads and in the nearby residential area....
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