| |
|
Invasive fish species in the Czech Republic
Lusk, Stanislav ; Lusková, Věra
In the Czech Republic, the following fish species are evaluated as invasive: Carassius auratus, a species showing a significantly negative influence on the occurrence of native species Carassius carassius and Tinca tinca in natural habitats. Certain manifestations and properties (such as the invasive way of dispersal, numerous populations, great ecological tolerance etc.) typical of invasive species can also be seen in Pseudorasbora parva, Ameiurus nebulosus, and Proterorhinus marmoratus. In some of its manifestations, even Cteropharyngodon idella can affect biodiversity in a negative way. One cannot exclude the future invasion or introduction of any alien species evaluated as invasive, particularly those of the genus Neogobius that occur in the Slovakian part of the Danube, and Perccottus glenii that has already invaded the Tisza River drainage area and the lower part of the Danube.
|
|
Sensory quality of chosen types of meat products
Javorská, Kateřina ; Sůkalová, Kateřina (referee) ; Vítová, Eva (advisor)
This Bachelor’s thesis deals with the evaluation of sensory quality of meat products. The 5 samples of pork ham of different quality and from different producers were selected for evaluation. The theoretical part focuses on the composition and properties of meat and meat products, and their production technology. The selected methods for sensory evaluation of quality are also mentioned. Ordinal and graphical scales were used for sensory evaluation of samples. The assessors evaluated these basic characteristics of the ham samples - color, appearance in the cut, preparation, consistency, smell, taste, saltiness and tenderness. The results were written down in the prepared questionnaires which were subsequently statistically and graphically evaluated. Sensory analysis was performed by group of students from the Faculty of Chemistry BUT.
|
|
Design of mobile horizontal wood-splitting machine
Dressler, Jan ; Škopán, Miroslav (referee) ; Knoflíček, Radek (advisor)
This thesis shows making of documentation for production powerfull wood-splitting machine for hardest forestal work. There are researched and soluted all phases of pre-production machine's lifecycle, also means analysis of conception, potentional risks and failures analysis and also definition of required properties. Based on those properties and results of analyses is possible to setting up condition which should be satisfied. At following part are descripted and shown features of machine-design . Main feature (component) of machine is its frame, also there are strenght analysis of frame. Machine movement features are mainly hydraulics pistons which are powered by asynchronous engine, whith alternative possibility movement by wheel tractor power-take off shaft or hydraulics output. There are performed all important properties. Working safety questions and high endurability of machine shold be also performed. At the end of work is realised conception and design study of forestal production system for wood processing with one universal source of energy – wheeled tractor.
|
| |
|
The properties of welding joint after hot-dip galvanizing
Vítek, Pavel ; Suchánková, Ivana (referee) ; Kubíček, Jaroslav (advisor)
The project elaborated in frame of Master's studies branch 2303T002 presents a study of welded joints for hot-dip galvanizing. On the basis of literature study it is assumed that zinc influences the properties of welded joints. Samples were made of high strength steels DOMEX and wear-resistant steels HARDOX which were welded using MAG. Subsequently, half of the samples treated with zinc. The evaluation is used tear test and test Vickers hardness. Finally, the project is the comparison of the measured values of galvanized steel and steel without zinc.
|
| |
| |
|
Vliv tepelného namáhání na mechanické vlastnosti FeNiB amorfní slitiny
Zábranský, Karel ; Jirásková, Yvonna
An influence of thermal treatment in the temperature range of 150 - 350 °C on the structural and mechanical properties of an amorphous FeNiB alloy is investigated. The high tensile strength of 2200 MPa in the as-prepared amorphous state slightly decreases with increasing temperature of annealing up to approximately 200 °C in opposite to microhardness where an increase is observed. Above 200 °C a pronounced deterioration of both characteristics reflect the embrittlement of amorphous structure without any indications of crystallization.
|
|
Fatigue properties of AZ61 magnesium alloy
Provazníková, Andrea ; Juliš, Martin (referee) ; Pantělejev, Libor (advisor)
This master’s thesis is dealing with low-fatigue behavior of magnesium alloy AZ61, prepared via squeeze casting method. The main aim of this work was to obtain the basic mechanical properties as well as the low cycle fatigue data. Additional metallographical evaluation of microstructure and fractographical analysis after fatigue tests was made.
|
guest ::
