The thesis deals with the influence of storage time on particular physical and rheolo-gical properties of a yolk of chicken eggs. Monitored eggs were stored at 6 °C for 8 weeks. The thesis describes the influence of storage time on physical characteristics of a whole egg, such as weight and shape index. As expected, the weight loss of chicken eggs was demonstrated during eight weeks storing. Egg yolk (colour, height, width, weight, index and density) was also described and evaluated in detail. According to our estimates, there are no significant changes in weight during yolk storing. But yolk index is distinctly decreased. During the final part of monitoring rheological properties were evaluated - apparent viscosity, time dependence of viscosity and dependence of shear stress on the shear rate (flow curves). The experiments have proved Newtonian behaviour of egg yolk throughout the storage. The storage time has also clear impact on flow properties of yolk. The results of each experiment were modelled using the power law (Ostwald-de Waele) model.

This thesis is focused on the rheological properties of cow, goat and sheep milk. These kinds of milk are described and compared in the first part. The thesis describes physical properties and technology of milk transport. Next part deals with legislation about milk in the European Union and in the Czech Republic. Special attention is given to the requirements of warehouse equipment and heat treatment of milk. Another part deals with analytical properties of milk (dry matter, protein, fat, lactose, acidity of the milk, electrical conductivity and density). In the last part are monitored rheological properties of these three types of milk. Selected samples are measured with shear stress depending on the strain rate. It is important because it helps us to determine what type of fluid is milk. Then, there is monitored dependence of the dynamic viscosity at the shear stress and effect of temperature on viscosity. These experiments demonstrated that milk belongs to liquids with Newtonian behavior. To evaluation the results was used Newton's law of viscosity and Ostwald de Waele model.

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The diploma thesis deals with the technology of welding aluminum alloy AW 5754 by a method of arc welding TIG and with covered electrode. Introduction contains information about aluminum alloys and their labeling according to ČSN EN 573-1,2. Additional attention is focused on evaluation of the weld quality according to ISO 10042 and subsequent evaluation of the defects according to ISO 65 20 to 1. In the experimental section was welded samples tested at first by non-destructive methods (visual, capillary, X-ray testing) and followed by a destructive measurement of the weld (evaluation of micro-hardness, macroscopic and microscopic tests, tearing issues). Furthermore, part of weldments was subjected to a laboratory corrosion test in an aggressive environment of a salt chamber and then evaluating of mechanical properties of welds in both methods.

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The thesis is focused on lactic acid bacteria with protective effects. The work deals with the effects of protective cultures on fresh cheeses and their effect on the sensory properties of fresh cheeses. The thesis also includes a chapter on bacteriocins, their properties and effect of the action on cells. The thesis also provides informations about applications of protective cultures and their methods of uses in the production of fresh cheese. In the practical part of the thesis is observed effect of protective culture on the sensory properties. There are sensory evaluated cheese with protective cultures and cheeses without these cultures. Also is observed the acidification of cheeses, with the protective cultures and the status of their durability compared to cheese without these cultures.

This diploma thesis: Transformation of the dynamic resistance of stainless steels due to structural inhomogeneity deals with the effects of corrosive damage on fatigue properties of stainless steels. The theoretical part deals with general principles of creation and chemical reactions, the factors affecting their speed, as well as, fatigue properties of materials (formation of cracks, stages of high cycles fatigue, fatigue slip zone etc.) and description of the method of non destructive testing the acoustic emission. The practical part describes executed experiment which focuses on comparing the results of fatigue tests between the standards and thermal and corrosion exposed samples. The actual measurements supplement microscopic images of the fracture surfaces and the records acoustic emission during measurements of some samples.

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