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Design of a 3D print head for mixing additives into cement mixtures
Vícha, Daniel ; Dočkal, Aleš (referee) ; Škaroupka, David (advisor)
The subject of the thesis is the design of a 3D printing head for cement-composite mixtures (concretes). The device enables the addition of the basic component of the mixture by using a liquid solidification accelerator, followed by active homogenization of the mixture and dosing at the printing site. 3D printing of cementitious mixtures often leads to a loss of buckling stability of the printout. Therefore, it is necessary for the printed material to contain additives that accelerate the solidification of the mixture. However, these additives can cause clogging of the hoses when the mixture is pumped into the print head due to premature solidification. Hence, a more suitable solution is to mix these additives in the print head itself. The objective was to develop a 3D print head that allows for homogeneous mixing of the additives in the mixture, thereby eliminating complications associated with pumping. A working prototype of the print head was designed, which consists of a mixing and extrusion chamber. The mixing efficiency of this prototype was verified through numerical simulations using Particleworks. Subsequently, the prototype underwent a mixture experiment without a solidification accelerator to investigate pumpability through the printhead. Based on the numerical simulations, it was determined that the proposed prototype provides sufficient homogeneity of the solidification accelerator with the cement mixture, which should resolve the issues associated with pumping the accelerated mixture. By having a separate mixing chamber, the mixing efficiency can be controlled by adjusting the speed of the motor that drives the mixing shaft. The print head was designed to allow extrusion to be interrupted during print head passes. This was achieved by extruding the mixture into the open space of the chamber using a screw feeder. Therefore, based on the conducted experiments and numerical simulations, it can be concluded that the developed print head has the potential to enhance the quality of 3D printing of cement mixtures and eliminate the problems associated with pumping.
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Filament Winding Machine
Dorňák, Michal ; Hampl,, Štěpán (referee) ; Foller, Bronislav (advisor)
The aim of this diploma thesis is the proposal of solution of three-axial winding machine for winding technology of rotary profile. Winding materials are continual springs of carbon, aramid or glass fibre impregnated by resin. The main construction change of the machine compared to commercial available solutions is the use of linear motor as a frame element instead of roller screws or toothed chain. Linear motors have higher dynamics of the movement and they can reach higher speed compared to other solutions, which guarantee increase of the machine productivity. The main importance is put not only on the functionality but also on the low price of this solution. The 3D model of the mechanism is created in the program Inventor 2009.
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Design of the robot head for palletising buckets
Bukovský, Radim ; Kovář, Radoslav (referee) ; Kašpárek, Jaroslav (advisor)
This diploma thesis deals with the design of a robot head, which is intended for transfering plastic buckets from the belt conveyor to the pallet. The document comprises of the analysis of various solutions, the part with calculations of selected components, the pneumatic circuit design and the proposal for a periodic service system. The complete drawing documentation can be found in the appendixes.
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Finite element modelling of voice propagation through the vocal tract and around the human head
Tomeček, Vojtěch ; Pellant, Karel (referee) ; Švancara, Pavel (advisor)
This diploma thesis deals with creating of finite element model for the analysis of acustic waves radiation through human vocal tract and through the head surrounding space. The thesis contains a short overview of the anatomy of relevant parts and a short overview of formerly published models relevant to the topic. Then the process of creating the 3D model of human head, including the vocal tract, based on CT scans, and the mesh itself follows. This is succeeded by the computational solution taking in the acount the acoustic absorption of the vocal tract walls and radiation into the open space. The results gained are compared to relevant literature on this topic. The changes in frequency spectra in specific nodes of the mesh are reviewed and compared to relevant literature on the topic. The results could be used as basis of eventual frequention corrections of microphones used for voice diagnosis or registration in general, eg of speach or singing.
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Anthropomorphic Metaphors in Czech and in Spanish: Analysis of non-literary texts
DUDOVÁ, Štěpánka
The aim of our work is to analyze 500 samples from the Spanish and Czech corpora. When analyzing the samples, we will focus on the occurrence of anthropomorphic metaphors. Due to the large amount we generated, we specified our search for a lexical unit head and la cabeza. The thesis is divided into two parts, theoretical and practical. The theoretical part includes the approximation of the terms of metaphors and metonymies from the literary and non-literary point of view and the practical part of the analysis and description of the found excerpts. After analyzing all the lexical units in the practical part, there is a chapter containing the comparison of the excerpts in both languages and a summary in the Spanish language.
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Head in the Linguistic Picture of the World in Czech
Čížková, Klára ; Vaňková, Irena (advisor) ; Bozděchová, Ivana (referee)
This thesis focuses on the image of "hlava" (head) in the Czech linguistic picture of the world. It is based on theories and methods of cognitive linguistics. The purpose of the thesis is to describe the structure of the meaning of the word hlava. The paper by I. Vaňková and V. Vitkovskaya was used as a methodological and theoretical starting point. In that paper four semantic profiles of "hlava" are defined. The results of Vaňková and Vitkovskaya were compared with the findings of our research. We try to find out, whether the mentioned profiles are valid on a larger linguistic material, too. Two types of data are analysed - systemic data (especially phraseology, then also etymology of the word, derivatives, compounds and synonyms) and corpus materials (from Czech National Corpus). Then, we also compare the differences in the findings between systemic and textual (corpus) data. Finally, all results are summarized in the cognitive definition of hlava.
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Finite element modelling of voice propagation through the vocal tract and around the human head
Tomeček, Vojtěch ; Pellant, Karel (referee) ; Švancara, Pavel (advisor)
This diploma thesis deals with creating of finite element model for the analysis of acustic waves radiation through human vocal tract and through the head surrounding space. The thesis contains a short overview of the anatomy of relevant parts and a short overview of formerly published models relevant to the topic. Then the process of creating the 3D model of human head, including the vocal tract, based on CT scans, and the mesh itself follows. This is succeeded by the computational solution taking in the acount the acoustic absorption of the vocal tract walls and radiation into the open space. The results gained are compared to relevant literature on this topic. The changes in frequency spectra in specific nodes of the mesh are reviewed and compared to relevant literature on the topic. The results could be used as basis of eventual frequention corrections of microphones used for voice diagnosis or registration in general, eg of speach or singing.
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Filament Winding Machine
Dorňák, Michal ; Hampl,, Štěpán (referee) ; Foller, Bronislav (advisor)
The aim of this diploma thesis is the proposal of solution of three-axial winding machine for winding technology of rotary profile. Winding materials are continual springs of carbon, aramid or glass fibre impregnated by resin. The main construction change of the machine compared to commercial available solutions is the use of linear motor as a frame element instead of roller screws or toothed chain. Linear motors have higher dynamics of the movement and they can reach higher speed compared to other solutions, which guarantee increase of the machine productivity. The main importance is put not only on the functionality but also on the low price of this solution. The 3D model of the mechanism is created in the program Inventor 2009.
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Design of the robot head for palletising buckets
Bukovský, Radim ; Kovář, Radoslav (referee) ; Kašpárek, Jaroslav (advisor)
This diploma thesis deals with the design of a robot head, which is intended for transfering plastic buckets from the belt conveyor to the pallet. The document comprises of the analysis of various solutions, the part with calculations of selected components, the pneumatic circuit design and the proposal for a periodic service system. The complete drawing documentation can be found in the appendixes.
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