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Development of Web-Based Computational Tool for Analysis of Microcalorimetry Data
Nedeljković, Sava ; Musil, Miloš (referee) ; Sumbalová, Lenka (advisor)
Proteins are organic molecules made up of amino acids which are present in all living organisms. They are the main building blocks of life. Study of protein stability has great application in pharmaceutical, biochemical and medical industries, which makes it in high demand. Stability of a protein and many other properties can be determined by observing its unfolding mechanisms. Differential Scanning Calorimetry (DSC) has proven to be a very precise method for this task. The main goal of this thesis is to improve functions of software CalFitter, which analyses data obtained from DSC experiments. The new functionality of the software enables it to automatically calculate initial parameters, which are needed for successful analyses.
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Determination of binary phase diagram
Dobeš, Pavel ; Havlík, Petr (referee) ; Jan, Vít (advisor)
This bachelor's thesis deals with the analysis and verification of binary diagram of the Ag-Sb system. The theoretical segment of the thesis describes the sub-elements of this system, the function of binary diagrams and the methods of thermal analysis. The experimental segment mainly deals with the interpretation of DSC signal, the analysis of the microstructures of specific Ag-Sb system samples and the comparison of the acquired data with the given binary diagram.
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Study of emulsion stability by means of physical-chemical and optical methods
Kuchyňová, Jitka ; Veselá, Mária (referee) ; Zmeškal, Oldřich (advisor)
The diploma thesis deals with the stability determination of model O/W (30/70) emulsions at 25°C. In fact, the time and emulsifier concentration (Tego Care PS) dependences of physical properties (aging) were monitored. In the second part of the work, the influence of conservant on emulsion stabilities were studied. In order to study physical properties of emusions rheometry, differential scanning calorimetry (DSC) and optical microscopy were employed. The rheological measurement provided information on viscosity and viscoelastic modulus. DSC experiments used the repeated freezing/thawing cycles which allowed monitoring of changes in crystallization temperature of water present in emulsions and melting enthalpy of ice formed during the cooling. The optical microscopy was used to examine the change in oil droplet size in the course of emulsion destabilization and phase separation. In this case the image analysis was carried out using program HarFA. The results showed that due to the emulsion creaming, the oil droplets diffuse and aggregate which causes phase separation. Those processes were quickest for the emulsion with lowest emulsifier concentration 0.1 % (destabilization during 51 days) The emulsions with emulsifier concentration about 1.5 and 1.3 % were stable at least for 4 months. The presence of the coemulsifiers increased the elastic modulus and descreased the phase difference due to the network formation. It was shown that for the stability determination is necessary to use conservant due to risk of microbial contamination. DSC experiments allowed to distingush samples prepared under different conditions. Lower rotational speed during emulsion preparation caused the appearance of two melting and crystalization peaks while for higher speed only one peak was observed.
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Universal BLDC motor controller
Pijáček, Ondřej ; Pohl, Lukáš (referee) ; Veselý, Libor (advisor)
This thesis describes the design of universal control unit for BLDC motor powered from airplane power distribution system of 28 V capable of driving motor up to 10 A. The maximal engine power is about 250 W. Important prerequisite is possibility of driving various motor size without needs of changing wiring board using only the configuration in the auxiliary memory unit. To control different motors is enough one unit with one program without any way to interfere to the unit itself.
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Physical ageing of polypropylene
Weiss, Jiří ; Kučera, Jaroslav (referee) ; Tocháček, Jiří (advisor)
Physical aging of commercially produced polypropylene homopolymers Mosten was studied. The work is focused on monitoring the changes in physical properties of polymer in the time period 90 days from the date of preparation of the test specimen. The aging of polymers was realized at storage temperatures of 23 and 80 °C. The changes in crystallinity, yield strength, modulus, elongation and impact strength using DSC method, tensile tests and impact tests according to Charpy were monitored. Molecular weight distribution was determined by means of GPC at each polymer. Relationships between the changes in physical properties and polymer molecular weight were sought.
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Optimized manufacturing of aluminium castings by using lost wax technology
Talanda, Ivan ; Horenský, Jiří (referee) ; Horáček, Milan (advisor)
Aim of this diploma thesis is to choose new pattern wax for Fimes a.s. foundry. New wax should substitute old not fully satisfactory pattern wax which caused problems in technological process resulting in increased number of rejects. New pattern wax should eliminate current problems and help foundry with producing large, thin-walled, high-quality castings. Numbers of pattern waxes supplied by world’s leading wax manufacturers were subjected to laboratory tests and pilot study. This diploma thesis is part of project Alfa TA01010766: „Research and development of production technology large, thin and high quality castings of aluminium alloys “
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Universal low voltage converter
Pilch, Tomáš ; Pazdera, Ivo (referee) ; Knobloch, Jan (advisor)
In this diploma thesis, universal inverter was manufactured and successfully tested with DC, BLDC and AC motor. Inverter is composed of the power board for driving extralow voltage supplied electric motors (from +12V to +24V) and control board with microcontroller MC56F8257. There is also explained the principle of driving DC, BLDC and AC motor as well as description of the most frequently used peripherals and inverter. components
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determination of kinetic parameter of reactions using DSC
Kopecký, Jan ; Kouřil, Miloslav (referee) ; Jan, Vít (advisor)
The master thesis deals with DSC measurments a calculation of kinetic parameters. In the theoretical part, iron alotropy is briefly described, followed by a description of the DSC analysis itself. The thesis also includes division and derivation of isoconversional methods for calculating the activation energy. In the experimental part, a series of measurments is perfomed on pure iron prepared by Cold Spray method. In the paper the influence of deformation on the Curie temperature of the magnetic transformation in -Fe and transformation > is investigated. The activation energy is calculated for transformation > for different degrees of deformation. The degree of deformation is monitored by channeling contrast.
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Pultrusion process optimizing of composites based on epoxy matrix
Ostrezi, Jan ; Bábík, Adam (referee) ; Přikryl, Radek (advisor)
The theoretical part of this bachelor thesis deals with current progress in the field of long fibre reinforenced composites with matrix based on epoxy resins. It also deals with production methods of composite materials, especially pultrusion. The practical part is based on pultrusion process optimizing of composites profiles based on epoxy matrix. Profiles were examined by DMA test to set the glass transition temperature.
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