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Production of castings from austenitic-ferritic hyperduplex stainless steels
Kaněra, Miloš ; Pernica, Vítězslav (referee) ; Záděra, Antonín (advisor)
The thesis deals with hyper duplex stainless austenitic-ferritic steels and their mechanical and castability properties. The evaluation of resistance to pitting corrosion is divided by PRE values. Steels with a PRE value higher than 48 belong to the group of hyper duplex steels. The theoretical part contains an introduction to the chemical composition, structure and properties of these steels. The practical part is focused on the conditions of tendency to crack castings during solidification and cooling. Furthermore, there is evaluated influence of intermetallic phases on mechanical properties.
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Quality parameters of dry fermented sausages
Pavlík, Zdeněk ; Ing.Miroslav Jůzl, Ph.D. (referee) ; Alena,, Saláková (advisor)
The aim of this study was to evaluate quality parameters of dry fermented sausages. Samples of two types of dry fermented sausages were sampled – sausage “Poličan“ and “Lovecký salám“, from three different producers. Basic physical-chemical analysis of quality parameters were performed in sausage mixture and immediately after end of ripening (21 days for Poličan and 16 days for Lovecký salám). Results of quality parameters analysis were compared with requirements of Czech legislation and differences between producers were observed. There were significant differences between producers, however all of them met requirements set by 326/2001 Czech notification as amended of Ministry of agricultural.
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Comparison of selected nutritional parameters of lesser known small fruit
Kaniová, Lenka ; Vránová, Dana (referee) ; Vespalcová, Milena (advisor)
The work deals with the chemical analysis of fruits and juices selected varieties of mulberry (Morus) and elderberry (Sambucus nigra L.). In the theoretical part there are the botanical characteristics of mulberry and elderberry, including the origin, history and prevalence. This part is focused on the content of active substances in fruits with a description of certain chemicals and the use of the fruit for food purposes. Finally, this section discusses methods for the determination of water content, soluble solids, pH, titratable acidity and formol number. In the experimental part was do determination in up in four samples of two varieties of mulberry and in samples of fifteen varieties of elderberry. Based on these results, it is possible to deduce the nutritionally important varieties. Mulberry Trnava and elderberry Sambu I contain the most water, and therefore are suitable for the production of juices. Unripe mulberry Trnava elderberries Samyl 2, Sambu I, Sambu 3 and Sampo I are the sourest varieties and they contain the highest content of mineral and organic acids.
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Influence of using the secondary metallurgy on steel properties
Navrátil, Horymír ; Fila, Pavel (referee) ; Záděra, Antonín (advisor)
This bachelor thesis describes metallurgical processes of production of steel in electric arc furnaces. It also describes oxidation and reduction phases of melting. Furthermore, it describes the main elements of secondary metallurgy used in steel foundries and their applications. The thesis also concerns with impurities in the steel, namely non-metallic inclusions, gases and trace elements, which is also connected with final utility properties of the steel. This thesis also describes in detail the technological properties of steel. The influence of several selected elements on steel properties is also described. Finally, the thesis evaluates the effect of secondary metallurgy on the volume of defects in steel castings, on mechanical properties and the resulting chemical composition.
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Structure of Heat Resistant Steels
Skýba, Pavel ; Foret, Rudolf (referee) ; Jan, Vít (advisor)
This work is a compilation essay about structure of heat-resistant steels, creep, strengthening and heat treatment based on available literature sources. The main chapters of the work deal with creep deformation, its mechanisms and the ways of strengthening used in heat-resistant steels. Separate chapters deal specifically with precipitation strengthening, minority phases that can be found in heat-resistant steels and their heat treatment.
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Mechanically separated meat from poultry produced by different techniques: Proteins, fat and bone fragment determination.
Čížková, Silvie ; Babák, Libor (referee) ; Šalplachta, Jan (advisor)
The diploma thesis is focused on mechanically separated chicken meat (MSM), which was produced on the machine Baader 601 (soft way of separation) and Lima D (hard way of separation). The history, production, composition and legislation relating to the MSM have been described in the theoretical part. The experiments involving the results of the determination of total solids, total fat, total protein, muscle protein and collagen have been introduced in the experimental part. Bone fragments have been determined by weight and visually after alkaline hydrolysis of samples at elevated, respectively atmospheric pressure. Results have been evaluated with regard to the feedstock and the method of mechanical separation. Values have been compared with data published in the scientific literature and legislative requirements. Data from the experiment confirm high variability and thus different food quality of MSMs, depending on the sort of feedstock used in the production of MSM and the separation method.
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Složení a využití masa ryb
Žilková, Lucie
The diploma thesis "Composition and use of fish meat" is focused on the loss of water during smoking of fish fillets, the chemical composition of fish muscle, color measurement and a questionnaire survey of the consumption of fish and fish products. For the experimental part, African catfish (Clarias gariepinus) fish samples were used at the age of 6-9 months (smoking, chemical composition, color measurement) and 5-6 years (chemical composition, color measurement). Smoking was carried out with warm smoke for fish samples in the form of fillets with skin. The water loss per 1 kg of fish muscle was 220 g, i.e. 22% water loss. During the chemical determination of the composition of fish muscle, where dry matter, fat and proteins were determined, the dry matter content of the raw fish before smoking was 20-22%, fat 1-4% and protein 16-18%, after smoking the dry matter content was 27-32%, fat 2-7% and protein 22-25%. (depending on the part of the carcass.) Determination of chilled and frozen fish muscle showed a dry matter content of 23-34%, fat 3-17% and protein 15-20% for chilled, dry matter content for frozen 21-36%, fat 1-20 % and protein 14-19% (depending on the type of muscle and part of the carcass). Color measurement using a spectrophotometer in the CIELab color space did not yield any statistically significant difference when comparing smoked and raw fish or when comparing the color of light and dark muscle in chilled and frozen conditions. The questionnaire survey investigated the consumption of fish and fish products. A number of 200 respondents said that they consume fish in the range 1x a week to 1x a month. Most of the respondents had not heard of the new products, but they would like to try fish sausages, ham or tartare.
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Způsoby marinování a nakládání ryb
Fichtnerová, Lenka
The bachelor thesis on the topic "Methods of marinating and pickling fish" deals with the characteristics of individual freshwater and marine fish species, which are the most used in the food industry, their nutritional value, and nutritional properties. The introductory part focuses on the description of specific fish species, the different components of fish meat and their impact on human health. Furthermore, special hygienic rules for handling fishery products were described, which are determined by both Czech legislation and European Union regulations. Subsequently, the various methods of fish processing that ensure the extension of the shelf life of fish meat are explained in detail. This is followed by a description of the various methods, including marinating, pickling, and preserving. Finally, the sub-processes are evaluated in terms of the processing requirements, the raw materials used and the shelf life of the products.
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Kvalitativní parametry a využití masa nutrie říční
Neudertová, Karolína
The aim of the bachelor thesis Quality parameters and uses of nutria meat was to conduct a literature search focusing on the use of nutria meat in the Czech Republic and in the world. Nutria breeding has a long tradition in the Czech Republic. Previously, breeding was primarily focused on the production of quality fur, with meat and fat as by products. Nutria meat is often sought after in developing countries such as Africa or Asia, where nutria meat increases food self-sufficiency. Among European countries, nutria meat and products have a market presence in France. Nutria carcasses do not contain the head, skin, genital organs, bladder, gastrointestinal tract, distal parts of the legs, thoracic organs, liver, kidneys and peritoneal fat. The protein content of nutria meat ranges from 19.2 to 25.5 % and the fat content ranges from 4 to 10 %. Nutria meat has a higher collagen content than rabbit meat, making it more tender and more sought after by consumers. The meat is characterised as tender because of its higher peritoneal fat content. Nutria meat has a low intensity of aroma and flavour, so appropriate culinary preparation is important. In terms of technological parameters, nutria meat has a higher pH value and a darker colour.
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SUBMICRON AEROSOL AT TWO URBAN STATIONS IN PRAGUE
Pokorná, Petra ; Zíková, Naděžda ; Vodička, Petr ; Lhotka, Radek ; Ondráček, Jakub ; Schwarz, Jaroslav ; Ždímal, Vladimír ; Hopke, P.
The aim of this work was to determine the submicron aerosol dynamics, chemical compositions, and origins at two sites in Prague based on the particle number size distribution (PNSD) and chemical composition of 2/12/24h atmospheric aerosol samples (PM1) collected in parallel for half-year/within two seasons at two urban sites (suburban – Suchdol and traffic – Vršovice). Chemical analysis of PM1 for carbon (elemental, equivalent black – eBC and organic) by thermo-optical method and for water-soluble inorganic ions by IC was performed. For most months, both number and mass median \nconcentrations based on the SMPS data differed. Higher eBC concentrations were measured in Vršovice however eBC concentrations showed good correlation (r=0.80, yintercept=0) at the two stations. Higher average PM1 at the traffic site in summer and at the suburban site in winter, and seasonal differences in ionic PM1 composition reflected the seasonality of the local sources. Nevertheless, there were no statistically significant differences in PM1 concentration and ionic composition between the sites.
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