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Model of DC motor
Turanský, Luboš ; Dvořáček, Martin (referee) ; Chomát, Luděk (advisor)
In this work is described essential division of electric motors and possibilities of their regulation. In detail is shown how was obtained mathematical model of DC motor and its implementation to Matlab/Simulink. Subsequently is described how was created hardware and firmware of model which is simulating behavior of described DC motor. Final model is connected with PLC. For PLC is created visualization which allows monitoring of regulation process and changing PSD regulator parameters. Last part of the work is model manual and task laboratory exercise for the model.
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Design of unit for Power HIL simulation of DC motor
Chalupa, Jan ; Maršík, Jiří (referee) ; Grepl, Robert (advisor)
This thesis deals with analysis and implementation of Power-HIL system that is designed to simulate real DC motor with comutator and permanent magnets. For problem analysis were used simulations of real components in Matlab / Simulink. The electronic parts of system were simulated with using the SimElectronic library. Idividual hardware components were designed according to simulation results. The outcome of this thesis is a power electronic simulator of real DC motor, which is implemented on dSPACE platform. The system allows software to setup parameters and behavior of simulated motor. The final system can be used for testing DC motor ECU (electronic control units).
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Analysis of some biologicaly active components in natural plant extracts
Kováčová, Ivana ; Márová, Ivana (referee) ; Němcová, Andrea (advisor)
This thesis is focused on the study of the effectiveness of active ingredients from natural extracts such as milk thistle and turmeric. The thesis describes the use of modern methods of analysis and identification of active substances located in plants of milk thistle and turmeric. In the experimental part of thesis, which was preceded by a literature search focused on the biological effects of active substances in the chosen natural extracts, the extracts were characterized according to group characteristics (total assessment of polyphenols and flavonoids, assessment of antioxidant activity, and assessment of vitamin C volume and tocopherol). The next part is focused on the study of the encapsulation of natural active substances into the organic particles: liposomes. Silymarin and curcumin were encapsulated as active substances. The idea of a plant with a single active ingredient is usually erroneous. Plants usually contain hundreds of components which cooperate on a given effect. Therefore, the majority of herbalists believe that a simple plant is an active ingredient. However, some plants are known to be containing a particular active phytochemical. For instance, plants such as the milk thistle, turmeric, or a ginkgo are great examples of the plant containing a particular active phytochemical. In these cases, the active compound is disproportionately more effective than the plant itself. Encapsulation efficiency of active ingredients of Silymarin and curcumin was determined by HPLC/PDA. The aim of the analysis was to observe the behavior of elements during the incubation in surrounding of gastric juice model, and the stability while maintaining the particles in model food.
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ICP-OES with electrothermal vaporisation (ETV) as a possible tool for direct analysis of biologic samples
Matějková, Stanislava
Solid sampling electrothermal vaporization (ETV) inductively coupled plasma optical emission spectroscopy (ICP-OES) enable simple and rapid multielemental analysis of major, minor and trace elements without the need for pre-treatment of solid or liquid samples. By comparison with more common ICP-OES combined with a solution nebulization, the risk of contamination of analysed samples is reduced. The detection limits and the sample quantity needed for analysis via ETV-ICP-OES decrease as a result of the high-efectivity transport of the sample aerosol into the ICP torch. The connection of ETV unit to simultaneous ICP-OES allows us the fast direct and fully automatised analysis of numerous samples. The technique enable usually the combined calibration with home-made or certified solid and aqueous standards. We developed the methodology for tracking the carboran-based candidate-drugs time dependent concentration and for their pharmacokinetic evaluation. The method is based on direct boron or together boron and cobalt contents direct estimation in little amounts of fresh frozen mice tissues (5 – 10 mg of serum, brain or liver).\n
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Applications of chiral and achiral chromatography in pharmacology and toxicology
Chytil, Lukáš ; Slanař, Ondřej (advisor) ; Bultas, Jan (referee) ; Coufal, Pavel (referee)
Development and validation of methods for analysis of several drugs or their metabolites are decribed in this thesis. The document is presented as a commentary to the original papers, which were published in peer reviewed journals. Discussion on the optimization of each method is presented and covers also method development and influence of preanalytical aspects. Additionally, examples of the application of the developed methods in clinical pharmacology and toxicology are shown. This dissertation consists of three parts: enantiomeric determination of tramadol and its metabolite, determination of some antihypertensive drugs, and qualitative analysis of benzodiazepines. Development of a method for chiral analysis of tramadol and its desmethylated metabolite O- desmethyltramadol (ODT) in human urine and plasma is described in the first part of the thesis. Tramadol is a centrally acting analgetic drug, which is used as racemate in clinical practise. Each enantiomer displays different binding properties for various receptors: (+)-tramadol preferentially inhibits serotonin reuptake while (-)-tramadol mainly inhibits noradrenalin reuptake. (+)-tramadol is considered 10-times more potent than (-)-tramadol. Major active metabolite (ODT), which is considered to be the main agent responsible for the...
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Enterprise use of social networks
Píša, Luděk ; Pavlíček, Antonín (advisor) ; Böhmová, Lucie (referee)
The thesis deals with theme of social networks especially from the view of companies. The thesis is divided into two main parts -- theoretical and practical. There is a necessary knowledge base of social networks and its use from perspective of a company in the theoretical part. There is also mentioned the topic of social networks analytics because it's the main theme of the practical part of the thesis. The research in the practical part analyzes the companies from Czech Republic, Germany and United States of America. The research is aimed on their behavior on Facebook and their company presentations there. There are two methods used in the practical part. One method compares the list of companies during the time period of 3 year (90 days of 2011 compared to 90 days of 2014). The other one compares the list of companies from geographical point of view. The goal of the practical part of the thesis if evaluation of pre-defined hypotheses.
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Operational Parameters of LED and their Modelling
Pavelka, Tomáš ; Novák,, Tomáš (referee) ; Gašparovský, Dionýz (referee) ; Baxant, Petr (advisor)
Doctoral thesis deals with parameters of LED light sources and their static and dynamic changes due to variable operational conditions. Firstly there is briefly described the history of light emitting diodes, that brought LED from unintentional observation of luminescence to light source, which is generally used through the whole area of lighting techniques. Thesis focuses on light parameters analysis, which are specific for semiconductor light sources and their mutual relations. These relations in compliance with understanding the principles of light emission in semiconductor light sources enable establishing of basic connections and effects usable for LED behaviour model. Mutual relations of LED parameters and influencing factors are verified by measurement of chosen testing samples. For deeper understanding of diode parameter influencing mechanisms there are analysed current degradation models including degradation of partial components. On the basis of these facts there is created a model of LED luminaire operating with LED parameters together with cooling system that represent the integral part of the luminaire. Impact of supply drivers is also studied, because they are necessary for LED operation. Designed model supports the area of static changes of light parameters, as well as the dynamic changes of output parameters. Presented model is verified by testing measurements at basic operational states and partially outside of the common operational limits. There are also presented the possibilities of real use of the model that involve the evaluation of designed luminaire for specific light sources, searching for optimal operational limits, optimization of luminaire heatsink or using public lighting systems for regulation of electricity grid load fluctuations.
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The synthesis of poly(butadiene)diol-based polyurethanes with LC properties
Poláková, Lenka ; Sedláková, Zdeňka (advisor) ; Šňupárek, Jaromír (referee) ; Hamplová, Věra (referee)
8 Summary The PhD thesis is focused on the synthesis and characterization of low-molecular mesogenic thiols and poly(butadiene)diols and polyurethanes with LC side chains. Within the frame of this work, following tasks have been solved: Two groups of low-molecular compounds containing a biphenyl or an azobenzene as a rigid mesogenic part have been synthesized: N YNOSHXO SH Y = -H -OCH3 -O(CH2)3CH3 -O(CH2)7CH3 X = -H -CN Composition and structure of the prepared units were confirmed by elemental analysis and 1 H NMR spectroscopy. Thermal behavior, with the respect to the temperature-dependent mesophase formation, was studied by differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and X-ray scattering techniques (SAXS, WAXS). It was found that the presence and the type of the substituent on the mesogenic core play a crucial role in the ordering of the thiol molecules into a LC phase. The thiols synthesized were grafted onto double bonds of the commercially available telechelic poly(butadiene)diol Krasol LBH 3 000 (declared Mn ~ 2 600 Da, Mw/Mn = 1.10). The addition reactions proceeded in the presence of radical initiator (AIBN). Molar ratio of thiol/double bonds varied within the range of 0.15 (resp. 0.2) to 1.0 for each type of the thiol. The structure of the resulted comb-like...
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Design of Wheel Flange Lubrication Experimental Apparatus
Nepovím, Radovan ; Dzimko, Marián (referee) ; Hartl, Martin (advisor)
The diploma thesis deals with construction design and practical realisation of experimental apparatus for investigation of wheel flange track vehicle lubrication. Experimental apparatus in full-scale uses optical interferometry for investigation of lubrication behaviour in wheel flange contact. It is an innovative approach which has not been used for such experiments so far. The aim of the following measurement with this apparatus is to determine the minimal amount of ecological lubrication in wheel flange contact under certain conditions when there is no lubrication film interruption. The apparatus enables to measure real rail wear. This work contains the apparatus description for the study of wheel flange lubrication, wheel flange contact specifications, the description of its influence on wear and acoustic emission, and a detailed description of the experimental apparatus.
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Bioresorbable polyurethanes with controlled mechanical properties
Letavaj, Emil ; Žídek, Jan (referee) ; Kupka, Vojtěch (advisor)
Presented diploma thesis deals with preparation of bioresorbable polyurethanes (PUR) and their characterization. The theoretical part describes the feedstocks used for the PUR preparation and summarizes the knowledge about PUR used in medical applications. Experimental part presents characterization of bioresorbable PUR films prepared by reactive casting in one step without the use of organic solvents. The absence of solvents represents a great advantage due to their toxicity and subsequent removal from the resulting product. The synthesis of PUR was conducted under an inert atmosphere by polyaddition reaction of hydrophobic poly(e-caprolactone) (PCL) and hydrophilic poly(ethylene glycol) (PEG) with hexamethylene diisocyanate (HDI). Synthesis under an inert atmosphere was necessary due to a side reaction of isocyanate with atmospheric humidity, which causes the formation of porous films instead of continuous ones. Prepared PUR films were characterized for different PCL/PEG ratios and different isocyanate index (ratio of NCO/OH reacted groups). PUR (isocyanate index 1.05) with PCL content 90 wt. % and higher demonstrated tought behavior in mechanical tests. Increase of isocyanate index and decrease of PCL content under 90 wt. % caused fragile sample behavior. The reason of such behavior was the different ability of PCL to crystallize in the structure of the polyurethane network. Increasing the PEG content has improved the ability of PUR films to absorb water and enhanced the rate of hydrolytic degradation. By adjusting the PCL/PEG ratio and the amount of isocyanate, solvent free bioresorbable PUR with suitable mechanical (flexibility, toughness) and physical properties (swelling, degradation) can be obtained. Prepared PUR films could be used in biomedicine e.g. as vascular grafts.
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