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The significance of magnesium for human health
Škeřík, Jan ; Hrstka, Miroslav (referee) ; Vránová, Dana (advisor)
Aim of this bachelor thesis was to compare different forms of magnesium. The characteristics and history of magnesium was briefly described at the beginning of the theoretical part. The following chapters explain the importance of magnesium in the body, hypomagnesemia, hypermagnesemia. Another section describes magnesium effect on various diseases, increased intake of magnesium and magnesium metabolism. The ninth and tenth chapter describes the effects of nicotine and alcohol on the metabolism of magnesium and magnesium content in drinking and mineral water. Conclusion of the theoretical part is dedicated to the description of the analytical methods of dosage forms. At the heart of the practical part was using several commonly used methods to determine best magnesium addition. It was the method of determination of the mass uniformity, determining magnesium contents in the tablet, the determination of disintegration, dissolution determination and hardness determination.
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Milk composition changes after fortification milch cow feed with selected additive
Tůmová, Michaela ; Hrstka, Miroslav (referee) ; Křížová,, Ludmila (advisor)
This thesis is dealing with effect of supplement limiting aminoacid histidin, that was applied as duodenal infusion, on yield and composition of high production dairy cows milk. The theoretical part describes overview about milk composition and metabolism of dairy cows. There are described nutrition requirements of dairy cows for esential aminoacids. In this part are also presented principles of analytical methods used for analysis of milk. For determination of basic components of milk were used infrared spectroscopy and enzymatic-conductometry. Aminoacid profile of casein was determined by ion exchange liquid chromatography. In the experimental part is described method of experiment. There is described technique of acid and oxidative hydrolysis of lyofilized casein and technique of determination aminoacids in this hydrolyzated casein. Results of analysis were interpreted and discussed with literature. This diploma thesis was made as a cooperation between the Institute of Food Science and Biotechnology, the Faculty of Chemistry, University of Technology, Brno and the Research Institute for Cattle Breeding, Department of Animal Physiology and Nutrition, Pohorelice.
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Comparison of vitamin C content between less known kinds of fruit
Mařáková, Veronika ; Hrstka, Miroslav (referee) ; Vespalcová, Milena (advisor)
This thesis deals with the determination of vitamin C in different varieties of cornelian cherry (Cornus mas) and mountain ash (Sorbus aucuparia). The theoretical part describes the botanical characteristics of both plants, the extension in the CZ and in the world, methods of reproduction, the content of meaningful health substances and the importance of both plants in food-processing industry. Attention is paid to vitamin C, which is in their fruits in high quantity. Conclusion of the theoretical part discusses various methods of determination of vitamin C. The aim of the experimental part was to comparison of the vitamin C content in different varieties cornelian cherry and mountain ash. The chosen method for the determination of vitamin C by high performance liquid chromatography (HPLC) with UV detection was first tested on standards. Selected validation parameters of this method was then determined. Validated method was used to determine the content of vitamin C in nine varieties cornelian cherry and six varieties of the mountain ash. For comparison were also tested some samples of the determination of total vitamin C after reducing dehydroascorbic acid by using dithiothreitol (DTT).
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Assembled Steel Tanks
Konečný, Jiří ; Hrstka, Miroslav (referee) ; Marcián, Petr (advisor)
This thesis deals with the area of bolted steel tanks, which constitute a significant share of the total number of tanks of all types of tanks. In the first part of this thesis is mentioned short history of bolted steel tanks, tanks producers and major standards and standards governing the calculation and realization not only these tanks. In the next part of this thesis mentions the various segments and major parts of bolted steel tanks. This is followed by a short description of the assembling. The last section describes the creation of a computer model of roofs used in simulation program ANSYS and subsequently performed stress-strain analysis for snow loads according to various snow areas for different FEM model in the 2D and 3D levels.
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Stress distribution near sharp orthotropic bi-material notch tips
Krepl, Ondřej ; Klusák, Jan (referee) ; Hrstka, Miroslav (advisor)
Presented diploma thesis is concerned with problems of a stress singularity exponent and a generalized stress intensity factor determination, by dint the stress field in the vicinity of the stress concentrator can be consecutively determined. This task is possible to sectionalize into three parts. The first part summarizes basic information about linear anisotropic materials, deals with fundamentals of the linear elastic fracture mechanics and introduces its generalization to the case of the generalized stress intensity factors. The second part is dedicated to a special theory of anisotropic elasticity - Lekhnitskii-Eshelby-Stroh formalism (LES). Furthermore, a theory of the psi-integral is introduced, by dint the stress intensity factor is determined. The final part applies the LES theory and the psi-integral to the concrete material configuration of a crack on the bimaterial interface, a special example of a sharp bimaterial notch. By means of analytical-numerical algorithm in ANSYS and Silverforst FNT95 software the stress singularity exponents and generalised stress intensity factors are consecutively computed.
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Diurnal changes of Rubisco activity under ambient and elevated concentrations of carbon dioxide
Uhrová, Lucie ; Vítová, Eva (referee) ; Hrstka, Miroslav (advisor)
Diurnal changes of Rubisco activity under the impact of ambient (380 µmol mol-1) and elevated (700 µmol mol-1) concentrations of carbon dioxide were studied in beech (Fagus sylvatica). Samples from leaves were taken in the two-hour intervals from 4:00 to 21:30 on the 22. 7. 2009 and activity of Rubisco was determined spectrophotometrically. No statistically significant differences were found between Rubisco activity of leaves growing in ambient and elevated CO2 concentrations. No increase of Rubisco total activity after daylight shows that nocturnal inhibitor CA1P is not present or plays only negligible role in beech. During the day Rubisco activity showed only statistically insignificant deviations. A slight decrease of Rubisco activation state in the afternoon indicates the afternoon depression of Rubisco initial activity.
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Basic characterization of selected samples of animal feeds
Svoboda, Ilona ; Hrstka, Miroslav (referee) ; Vítová, Eva (advisor)
The aim of the diploma thesis was to choose poper parameters for a quick and simple characterization of animal feed, to verify working procedures and to apply these on chosen samples. Within the scope of this work, samples of animal dog feed produced in a private company „Adamkovy tlacenky“ were analyzed. The feed is in the form of brawn, stored in artificial casing; it consists of up to 80% of animal components and up to 20% of vegetable components, while the rest of the weight is the pork gelatine. The feed does not contain preservatives, colourings as well as any other chemically produced additives. For the analysis three formulas were chosen: "Hovězinka", "Kuřátko" and "Srdcovka", the composition of which is protected by the patent. The choice was made to include samples of different composition. The content of raw crude protein, fat, fibre, dry basis, and ash was determined. The obtained values were compared with the standards for feed normally utilized by the feed industry. The results will be used to improve the formulas and to develop new types of feed.
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Impact of elevated carbon dioxide concentration and nitrogen fertilization on protein content of glutenin fraction in winter wheat
Veselá, Markéta ; Vespalcová, Milena (referee) ; Hrstka, Miroslav (advisor)
This bachelor thesis studies the impact of elevated carbon dioxide concentration in the atmosphere and nitrogen nutrition on protein kontent in winter wheat (Triticum aestivum) var. Bohemia. Glutenin proteins were separated by SDS-PAGE method and protein quantification was performed by computer densitometry. It was proved that the nitrogen fertilization has a great influence on the amount of glutenin proteins, which increased in all samples. Effect of elevated CO2 concentrationis not nearly as significant, however certain differences can be seen. Samples of wheat grown under conditions of reduced UV radiation, and samples of wheat grown under natural conditions did not show great differences in the content of glutenins.
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Assessment of rutin in elderberries
Kaňová, Kateřina ; Hrstka, Miroslav (referee) ; Vítová, Eva (advisor)
This work is focused on determination of the concentration of rutin in the fruits of elderberry (Sambucus nigra L.). The theoretical part provides an overview of the properties, occurrence and use of elderberry in natural healing, medicine and food industry. Furthermore, important substances contained in elderberry, especially flavonoids, including rutin, are mentioned. Properties, biological effects and the possibility of determination of rutin are briefly described. In the experimental part the optimization and validation of the method of high performance liquid chromatography (HPLC), which is used for identification and quantification of rutin in fruits of 18 elderberry species, was performed. The pressurized hot water extraction was used for the preparation and solid phase extraction (SPE) for purification of the sample. The largest amount of rutin was found in a variety of elderberry Albida, 6,70 mg per 1 g of dry matter. High concentrations of rutin included varieties Haschberg, Sambu, Pregarten, Sambo and Sampo. On the other hand, the lowest concentration was found in variety Aurea, 1,24 mg.g-1. Finally, rutin content in elderberries was compared with the content of rutin in elder leaves and branches andwith significant sources of rutin – buckwheat and rue.
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Influence of early and late drought on grain proteins content and composition in early and late variety of wheat
Vojteková, Vanesa ; Zemanová, Jana (referee) ; Hrstka, Miroslav (advisor)
In this bachelor thesis, the influence of early and late drought on grain protein content and composition in an early and late variety of winter wheat was studied. The varieties used were Avenue and Tobacco.One part of the plants was cultured under the conditions of early drought (bloom season), another part was grown under the conditions of late drought (grain filling season), the last part was grown under the conditions of natural irrigation. Half of the plants were fertilized using nitrogen fertilizer (200 kg N/ha), the second half of plants were without nitrogen fertilizer (0 kg N/ha). Wet gluten, crude protein content, gliadin and glutenin content were determined from flour samples. Results were evaluated by analysis of variance. Drought resistance depends on the genotype. Tobak genotype is more tolerant to climatic conditions, but the drought had a more significant effect on gliadin and glutenin ratio than on the Avenue genotype. Late drought increased wet gluten content in both genotypes and both types of fertilization. On the other hand, the early drought did not affect wet gluten content. Early drought decreased gliadin content, with the exception of Avenue genotype without fertilization. Early drought also increased glutenin content. Late drought increased glutenin content only in the unfertilized variant. Early drought increased glutenin content which leads to decreased gliadin content, especially for nitrogen fertilization. Late drought caused a decrease of gliadin and glutenin ratio, except for Tobak genotype with fertilization. Late drought increased crude protein content, except for Tobak genotype without fertilization. Early drought decreased crude protein content, especially for the unfertilized variant.
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