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Determination of material volume expansion
Silvestr, Jiří ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This Bachelor’s thesis deals with the temperature dependence of the density of solid and liquid materials. First of all I measured the density of solid and liquid materials, from which I made an overview. In the next section I focused on application of volumetric and length expansion in practice and made a table of densities of materials and their appropriate temperature coefficients of volumetric or length expansion. Last section focuses on the practical measurement with one of the methods and their automation.
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Mathematical models of retention object of urban drainage
Pavlík, Ondřej ; Stanko,, Ing Štefan (referee) ; Pollert,, Jaroslav (referee) ; Prax, Petr (advisor)
This work deals with the use of 3D mathematical models of fluid in water management practice. Using 3D mathematical model was assessed retention tank Jeneweinova, which is situated on a sewer network of the city of Brno and is an important object of urban drainage. Retention basin designed to keep overflow from CSO chambers to Svratka and Svitavský náhon during storm events. Retention tank Jeneweinova is suitable for the assessment, because tank was designed bassed the Master Plan drainage of Brno using 1D mathematical model. Another factor was the physical model, which was build in LVV Vin FAST BUT. And finally, near the retention tank will be installed measurement on the sewerage network, which will be able to verify the results whitch has been predicted in this work. Mathematical model of retention tanks Jeneweinova was build in software FLOW-3D. FLOW-3D is a general purpose CFD (Computational Fluid Dynamics) software for flow of fluid in steady and unsteady mode and uses computational techniques to solve the equations of motion of fluids. This software is mainly used for the calculation of hydraulic fluids, gas flow and heat transfer simulations. Results from 3D mathematical model has been compared with the values in the physical and 1D mathematical model.
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Study of active mass volume changes of lead acid battery electrodes
Nevoral, Miroslav ; Vaněk, Jiří (referee) ; Křivík, Petr (advisor)
This bachelor´s thesis deals with detailed study of influence of thurst on attributes of positive and negative electrode masses of lead acid battery electrodes with main accent on explanation of measured characteristics. Three kinds of electrode systems were put together and measured. Measured characteristics of changes of thurst power were recalculated during charging and discharging to changes of total thickness of system.
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Loudspeaker System for Laboratory Measurements of Polar Patterns
Morkus, Filip ; Káňa, Ladislav (referee) ; Schimmel, Jiří (advisor)
In the first part the attention is aiming to the choice of suitable loudspeakers. For this choice it was necessary to set required criteria and parameters. The aim of the system was to have as wide reproducibility range of frequency as possible but on the other hand not to be too large. The other criterion was the quality of the loudspeakers and its price. In the second part there was frequency crossover suggested according to the parameters of the chosen loudspeakers. This was suggested for low frequency spectrum as well as for high frequency spectrum. When determining the dividing frequency there were thought over producer’s recommendations and frequency characteristics of the loudspeakers so that the dividing frequency was not set in the place where the loudspeaker does not have “constant” character. The third part concerns the construction of the loudspeaker case. There one can find more details about the construction of the loudspeaker system called D´Appolito and its constructional requirements. This part was kept to the previous parts because integrating “D´Appolito” needs setting the distance between the loudspeakers according to the dividing frequency. It was also necessary to count with their size. According to the loudspeakers parameters it was possible to calculate the capacity of the loudspeaker case, also its shape was said and geometric proportions were calculated. Then everything was simulated in suitable software. In the last part the complete loudspeaker system was measured in an anechoic room. There were the direction characteristics and frequency characteristics measured there. The results of the measuring were compared with the software simulations.
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Optimization of an aircraft wing rib
Kopřiva, Lubomír ; Suchánek, Miroslav (referee) ; Petruška, Jindřich (advisor)
Topology optimization is a method providing new direction in designing of a technical objects. The aim of topology optimization is to find optimal distribution of material in design space. This diploma thesis is focused on optimization of aircraft wing rib num.6 of the airplane EV-55 using a software HW/Optistruct 7.0 implemented in a software package HyperWorks 7.0. The optimization of the rib was calculated under four different load cases. Resulting shapes of the rib were then tested by strenght calculations in software ANSYS 10.0. Finally, the obtained data of weights of optimized ribs were compared with the weight of the original rib.
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The Influence of Weather and Calendar Cycles on Trading Volumes at World Stock Exchanges
Kovaľová, Andrea ; Vozárová, Pavla (advisor) ; Slaný, Martin (referee)
Studies investigating stock-exchange anomalies -- mainly with respect to returns and volatility -- have been emerging in recent years and decades. This work explores whether weather conditions, days of the week, length of daylight, seasonal affective disorder, holidays, and lunar phase affect trading volume. Segmented into two parts, the work primarily analyses time-series cross-sectional data covering 12 major stock exchanges and spanning from January 2010 to March 2015. The other part of the work focuses on a detailed analysis of the New York Stock Exchange using only time-series data obtained for the time period from January 2001 to December 2009. Additionally, this period is further split to two time spans as the NYSE fundamentally changed its trading system during the period in question. We find strong evidence of the Monday effect -- manifested in low trading volume on Mondays -- recognizable in the time-series cross-sectional part of the analysis, as well as in the time-series part. Other aforementioned anomalies either do not affect the trading volume significantly or their effect is statistically significant only in one of the two parts of the analysis.
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The multiple Riemann integral and its applications in mathematics and physics
BRDLÍK, Pavel
The diploma thesis surveys the problematics of multidimensional Riemann integral. The goals of the thesis are, firstly, to provide a clear summary of the Multidimensional Riemann Integration Theory, secondly, to describe the basic calculation methods on carefully chosen examples, and, thirdly, to demonstrate its practical use in mathematics and natural sciences in general.
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Stanovení dřevní biomasy stínících dřevin kávových plantáží v oblasti Villa Rica, Peru
Šeptunová, Zuzana
Allometric models for dominant shade tree species were developed for coffee agroforestry systems in Villa Rica, Peru. The studied shade tree species were Eucalyptus saligna, Pinus tecunumanii, Pinus radiata and Prumnopitys harmsiana. The models predict total aboveground biomass volume of tree trunk and biomass volume of the commercial utilizable tree trunk based on diameter at breast height, which was identified as the best predictor, R2 > 0,98. By non-destructive method of using Field-Map technology was measured 258 individuals. From these data have been calculated volumes of 4 types of cut outs destined for the local standards for determining the commercial utilizable tree trunk. Thus prepared data was interleaved with tested models. The best-fit model was logarithmic transformation of power-law. This model was used to determine total volume and two types of cut outs for all studied species. In all cases was reached high R2 between 0.98 and 0.99. For the other two types of cut outs data the best-fit model was Gompertz.
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