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The influence of aluminum toxicity on the dynamics of plant cortical microtubules
Pohl, Jana ; Schwarzerová, Kateřina (advisor) ; Pejchar, Přemysl (referee)
Aluminium toxicity is the main factor limiting plant growth on acid soils. Aluminium inhibits root growth within few minutes after aluminium treatment. The mechanism and primary target of his action is still unknown. In this diploma thesis the effect of aluminium toxicity on dynamics of cortical microtubules WT and pldα1 plants was studied using the EB1a-GFP marker. Polymerization rate in both the transition and the elongation zone increased immediately after the aplication of aluminium. Nevertheless, microtubules in the transition zone are much more sensitive to aluminium, because the aluminium-induced increase in the polymerization rate was higher than in the elongation zone. Plants lacking PLDα1 showed higher dynamics on plus ends of cortical microtubules compared to WT during aluminium stress, which enabled them to react faster to stress stimuli. Mutants showed lower sensitivity to aluminium and 100 μM concentration of aluminium ions has beneficial effect on root growth in pldα1. These results suggest that PLDα1 influences microtubule dynamics. Microtubules in pldα1 plants were more dynamic and they polymerized faster in the response to aluminium, which was accompanied by decreased sensitivity to aluminium stress compared to WT. Changes in microtubule dynamics may play a role in aluminium...
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Issue of Internal Tension in Materials during Machining of Thin-walled Components
Osička, Petr ; Chladil, Josef (referee) ; Sedlák, Josef (advisor)
This master thesis focuses on analysing the origins of residual stress in material caused by face milling. Representatives of three groups of aluminum alloys (5000, 6000, 7000) are compared by measurements. For measuring of the residual stress in aluminum alloys, the hole-drilling method was used by applying tensometric rosettes. In order to determine the influence of the used milling cutters', flatness of the machined surface was analyzed by comparative method. The thesis concludes with a discussion and an overall evaluation of the results.
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Productive milling of aluminum alloys
Dvořák, Jakub ; Žídek, Jan (referee) ; Jaroš, Aleš (advisor)
This bachelor thesis is focused on milling of aluminum alloys, where the technology of milling is described in the first place, then the cutting materials and aluminum alloys. The main subject of the work was to carry out the experiment. The Experiment was focused on influence of cutting conditions on the final quality of the surface with regard to machine time. The aluminum workpiece was milled at different cutting speeds and various feed per tooth. At the same time the quality of the surface was examened and machine times were calculated. The Experiment showed us, whether it pays to use higher cutting speeds and feed per tooth, keeping the set of limited values of surface roughness with respect to the machine time. The result of the experiment is the following - the increasing feed per tooth deteriorates the quality of machined surface, but machine time is reduced.
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Catalytic Activity of Cobalt Impregnated on Ordered Mesoporous Silica Materials in N2O Decomposition.
Kuboňová, L. ; Fridrichová, D. ; Peikertová, P. ; Mamulová Kutláková, K. ; Kozubová, S. ; Jirátová, Květa ; Obalová, L. ; Cool, P.
Three different ordered mesoporous silica materials, such as MCM-41, Al containing MCM-41 (mass ratio Si/Al = 10) and SBA-15, were prepared. In a next step, cobalt (5-8 wt%) as an active metal for redox reactions, was introduced by the impregnation. The prepared catalysts were characterized by AAS, EDX, N-2 physisorption, XRD, DR UV-Vis spectroscopy, Raman spectroscopy, TPR-H-2 and their catalytic properties were evaluated for N2O decomposition and reduction. The catalysts showed poor activity in N2O decomposition while the use of reducing agent (carbon monoxide) was beneficial for their catalytic activities. The lowest catalytic activity showed Co/Al-MCM indicating that the aggregated CoxOy species present in this catalyst were inactive and not beneficial for the catalytic activity.
Fulltext: content.csg -  PDF
Plný tet: NANOCON 2015 - PDF
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Multifunctional Building Brno
Prchal, Václav ; Drobníček, Ladislav (referee) ; Menšíková, Naděžda (advisor) ; Šuhajda, Karel (advisor)
Building concept is based on many factors which determine such a small plot of land. The building symbolizes the tendency to intensify the development, but as the first of its kind must also adapt to a low area in which it is planted so far. To reduce the size of the contrast of adjacent materials are brand new roof slanted towards low buildings, creating a line that from the perspective of a street in perspective seemingly follows the curve formed ridges houses in the block. Localizing the edge industrial zones to buildings not only traced angular features, but also the chosen material, which is most surfaces aluminum and glass. High population how busy traveling and working in the expanded urban area, which becomes a new landmark building and gives overall charge.
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Applications of aluminium alloys
Ponka, Ondřej ; Juliš, Martin (referee) ; Němec, Karel (advisor)
This bachelor thesis deals with basic overview of aluminum and its alloys. It deals with properties of primary aluminum, its production and the benefits resulting from the processing of secondary aluminum. The thesis also discusses aluminum alloys as well. It describes the basic alloying elements, their distribution and their specific properties. It also mentions the effects of the heat and surface treatments on the properties of the alloys. Finally, the thesis deals with applicability of aluminum and its alloys in various industries. Briefly describes the issue of specific applications and provides advantages and disadvantages arising from their use.
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Aluminium foams and their applications in engineering practice
Belák, Kristián ; Čížek, Jan (referee) ; Němec, Karel (advisor)
Bachelor thesis includes knowledge of aluminum foams and their practical use. The first part of the thesis is focused on the basic characteristics of aluminum and its alloys, consequently, there are characterized metal foams and stated their basic division. Further, there is also devoted considerable attention to selected methods of its manufacturing. Also, properties of these foams are mentioned, mainly the most important ones – mechanical. Thesis deals even about technological processing of foams and the last part contains description of selected applications of metal foams in technical practice.
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Assessment of phosphorus associated with Fe and Al (hydr)oxides in sediments and soils
JAN, Jiří
The established fractionation scheme of Psenner and Pucsko with consecutive BD and NaOH steps was shown to be ineffective in distinguishing between the stable crystalline (hydr)oxides and their more active amorphous and poorly crystalline forms. These forms highly vary in their ability to sorb P and thus in their ecological significance. Dissolution kinetics of the Fe and Al minerals were performed using both the BD and NaOH extraction solutions. The results were applied to modify the original fractionation scheme for better quantification of P associated with active Al and Fe (hydr)oxides, and better estimation of the amounts of these Fe and Al forms in soils and sediments.
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Photochemical degradation of dissolved organic matter - the kinetics of insoluble particles
ŠAVRDOVÁ, Tereza
This bachelor thesis deals with the kinetics of the formation of insoluble substances. In the theoretical part we will deal with photochemistry, kinetics and organic substances. What forms of aluminum and iron can be found in aquatic environments with different pH values. In the experimental part we will examine the kinetics of the formation of insoluble particles in water after photochemical irradiation. We will find out how it changes the concentration of aluminum, iron and carbon according to the length of irradiation and how pH can affect the final result.
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