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Qualification of welding procedure for aluminium alloy AW-5083 H111
Krejza, Jan ; Mrňa, Libor (referee) ; Sigmund, Marian (advisor)
The diploma thesis deals with the qualification of welding process of aluminum alloy EN AW-5083 H111. This aluminum alloy was used to make a Venturi tube. Therefore, a literature review has been developed dealing with the properties and use of aluminum and its alloys. The next chapter deals with the weldability of aluminum, aluminum alloys and the weldability of EN AW-5083 alloy. Part of the work is devoted to the used TIG method and its specifics when welding aluminum materials. The practical part of the thesis deals with the actual qualification of welding procedures according to the relevant standard and evaluation of production conditions according to the product standard. The last chapter deals with the overall manufacturing process of the Venturi tube.
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A variety of transpiration in the young spruce stands with different thinning management
Zavadilová, Ina ; Szatniewska, Justyna ; Vágner, Lukáš ; Krejza, Jan ; Pavelka, Marian
Managing the spruce forest growing beyond its favourable conditions is trading between water consumption and increasing biomass. We examined tree transpiration in four stands with different thinning intensities in a 40-year-old spruce forest in South Moravia. Tree transpiration was significantly higher under moderate and heavy intensity compared to low intensity and control plots. Tree transpiration differed also among trees of different sizes within the treatments and also between the treatments. The stem increment was visibly increasing with the intensity of treatment, particularly for suppressed trees. The findings show an ecological tree response two years after the thinning.
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Determination of stress of Norway spruce by direct methods
Krejza, Jan ; Světlík, J. ; Bellan, Michal ; Horáček, Petr
The aim of this methodology is to introduce methods of forest ground monitoring leading to evaluation of Norway spruce tree vitality. Certified methodology describes: measuring of the stem surface temperature by thermography, measuring of the sap flow, measuring the stem diameter fluctuation and by the analysis of xylogenesis and wood morphology. Emphasis was placed on the detection of the stress reaction before occurrence of the visual symptoms. The aim of this methodology is to present a comprehensive set of methods for measuring ecopysiological activity of a tree and to determine its health status. The goal of this methodology is to provide a unique tools for foresters and for forest management for direct and precise evaluation of health status of individual trees, but also a whole complexes of forest from the ground perspective. The individual methodological approaches are defined, can be used in practice and their interpretation is unambiguous. The novelty is based on the direct measurement of the physiological activity of the individual trees, which exclude any degree of subjectivity in the evaluation process.
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Qualification of welding procedure for aluminium alloy AW-5083 H111
Krejza, Jan ; Mrňa, Libor (referee) ; Sigmund, Marian (advisor)
The diploma thesis deals with the qualification of welding process of aluminum alloy EN AW-5083 H111. This aluminum alloy was used to make a Venturi tube. Therefore, a literature review has been developed dealing with the properties and use of aluminum and its alloys. The next chapter deals with the weldability of aluminum, aluminum alloys and the weldability of EN AW-5083 alloy. Part of the work is devoted to the used TIG method and its specifics when welding aluminum materials. The practical part of the thesis deals with the actual qualification of welding procedures according to the relevant standard and evaluation of production conditions according to the product standard. The last chapter deals with the overall manufacturing process of the Venturi tube.
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