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Design of vacuum pressing device for plastics
Chlup, Pavel ; Drápela, Miloslav (referee) ; Koutný, Daniel (advisor)
This diploma thesis is about designing vacuum pressing device for plastics as an important method of manufacturing semi-finished plastic products. In introduction part of this thesis there is described a process of this method, the application field among the another plastics processing technologies, basic information about using semi-finished products and moulding forms. There are three versions of solution. After the estimation of this versions there is a decision about a final form vacuum pressing device. One’s own design work contains a project of a device like this with the help of Autodesk Inventor CAD system. In the end of the work, there is financial balance-sheet too.
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Measurement of oxygen activity in ferro-alloys
Žák, Štěpán ; Čamek, Libor (referee) ; Záděra, Antonín (advisor)
The thesis deals with determination of the oxygen content in ferro-alloys with emphasis on direct oxygen activity measurement in the meltage. The practical part of the thesis contains statistical analysis of oxygen activity values measured in austenitic and duplex stainless steel meltages. The measurements were done in vacuum furnace before vacuuming and afterwards. Statistically significant dependency of oxygen activity on the temperature of meltage was discovered among the values measured after the vacuuming. Therefore, its value can be predicted based just on the temperature of the meltage. No statistically significant dependency was found among the values measured before vacuuming (except for the low Chromium austenitic stainless steel meltages). Hence, other factors need to be considered when predicting oxygen activity before vacuuming.
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Secondary metallurgy of steel
Neduchal, Bronislav ; Balcar, Martin (referee) ; Záděra, Antonín (advisor)
This bachelor thesis focuses on dividing of individual processes of secondary metallurgy, which are being used in steel foundries. It describes the influence of individual ingredients contained in the steel, the molten aggregate, the dividing of individual processes of secondary metallurgy and the metallurgical possibilities and advantages of individual processes. The practical part focuses on evaluation of individual layers of low-alloy steel GS20Mn5 using two EOP and EOP-LF-VD methods, as well as high-alloy steels X20Cr13 using the EOP-LFVOD method.
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Numerical modeling of the prestress hollow core slabs Spiroll type on the flexural support and the evaluation of the stresses
Kršík, Jakub ; Vejvoda,, Stanislav (referee) ; Kaplan,, Věroslav (referee) ; Křiváková, Jarmila (advisor)
The doctoral thesis describes the possibilities of numerical modelling of hollow core concrete panels, SPIROLL type. The commercial finite element program ANSYS 13.0 is used for the modelling. The focus is on the specific flexural support of the panel and on the distribution of the shear stresses in the panel ribs near the support. The goal is to valid actually used method for homogenization of the panel’s foreheads and its influence on the shear resistance by using four numerical models. The numerical models are compared and verified with two experiments. The first experiment is vacuum loading on the hollow core slab. Second experiment is about shear loading by applying the loading blocks. Four methods for design of hollow core panels are evaluated. It is the method based on main stresses, design according EN 1992 and EN 1168 and Yang’s method of prestress effects transfer. Based on the results, a method of considering flexural support for the evaluation of hollow core panels is proposed.
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Analysis of the Ultra-High Performance Concrete Stair Thread
Lisztwan, Dominik ; Daněk, Petr
In this contribution, experimental and numeric analysis of slender stair tread model made of an ultra-high performance concrete, is described. Task of the analysis is to determine the behaviour of the model under acting load. The experimental part is represented by the static load test with the use of a vacuum method. Besides that, nonlinear numerical analysis in the environment of the ATENA Science software, is described. Gained results from both parts of the analysis are compared and unusual behaviour of the model is discussed.
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Hodnocení kvality brambor pro potravinářské využití
Andrýsek, Lukáš
The aim of this diploma thesis was to elaborate a literature research on „Evaluation of potatoes quality for food use“. In the practical part, a laboratory analysis of potatoes quality was performed at the end of 2017. After considering all the important quality parameters, the best variety Antonia was chosen for the preparation of potato products which were evaluated based on sensory quality and textural characteristics depending on storage. In 2018, a production of vacuumed potato products with a focus on various preservation methods. The products prepared by blanching potatoes, by blanching with added citric acid, potatoes boiled in brine and their combinations were chosen for this work. After storage, tubers were found to be more resistant to water release to outer environment than before storage. Of all the prepared products, the variety blanching with the added citric acid was evaluated as the best in sensory quality.
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Measurement of oxygen activity in ferro-alloys
Žák, Štěpán ; Čamek, Libor (referee) ; Záděra, Antonín (advisor)
The thesis deals with determination of the oxygen content in ferro-alloys with emphasis on direct oxygen activity measurement in the meltage. The practical part of the thesis contains statistical analysis of oxygen activity values measured in austenitic and duplex stainless steel meltages. The measurements were done in vacuum furnace before vacuuming and afterwards. Statistically significant dependency of oxygen activity on the temperature of meltage was discovered among the values measured after the vacuuming. Therefore, its value can be predicted based just on the temperature of the meltage. No statistically significant dependency was found among the values measured before vacuuming (except for the low Chromium austenitic stainless steel meltages). Hence, other factors need to be considered when predicting oxygen activity before vacuuming.
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Numerical modeling of the prestress hollow core slabs Spiroll type on the flexural support and the evaluation of the stresses
Kršík, Jakub ; Vejvoda,, Stanislav (referee) ; Kaplan,, Věroslav (referee) ; Křiváková, Jarmila (advisor)
The doctoral thesis describes the possibilities of numerical modelling of hollow core concrete panels, SPIROLL type. The commercial finite element program ANSYS 13.0 is used for the modelling. The focus is on the specific flexural support of the panel and on the distribution of the shear stresses in the panel ribs near the support. The goal is to valid actually used method for homogenization of the panel’s foreheads and its influence on the shear resistance by using four numerical models. The numerical models are compared and verified with two experiments. The first experiment is vacuum loading on the hollow core slab. Second experiment is about shear loading by applying the loading blocks. Four methods for design of hollow core panels are evaluated. It is the method based on main stresses, design according EN 1992 and EN 1168 and Yang’s method of prestress effects transfer. Based on the results, a method of considering flexural support for the evaluation of hollow core panels is proposed.
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Secondary metallurgy of steel
Neduchal, Bronislav ; Balcar, Martin (referee) ; Záděra, Antonín (advisor)
This bachelor thesis focuses on dividing of individual processes of secondary metallurgy, which are being used in steel foundries. It describes the influence of individual ingredients contained in the steel, the molten aggregate, the dividing of individual processes of secondary metallurgy and the metallurgical possibilities and advantages of individual processes. The practical part focuses on evaluation of individual layers of low-alloy steel GS20Mn5 using two EOP and EOP-LF-VD methods, as well as high-alloy steels X20Cr13 using the EOP-LFVOD method.
|
|
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Design of vacuum pressing device for plastics
Chlup, Pavel ; Drápela, Miloslav (referee) ; Koutný, Daniel (advisor)
This diploma thesis is about designing vacuum pressing device for plastics as an important method of manufacturing semi-finished plastic products. In introduction part of this thesis there is described a process of this method, the application field among the another plastics processing technologies, basic information about using semi-finished products and moulding forms. There are three versions of solution. After the estimation of this versions there is a decision about a final form vacuum pressing device. One’s own design work contains a project of a device like this with the help of Autodesk Inventor CAD system. In the end of the work, there is financial balance-sheet too.
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