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Static analysis of a concrete outlet channel
Skalník, Stanislav ; Nováček, Jan (referee) ; Zich, Miloš (advisor)
The thesis deals with the static analysis associated with the outlet channel of the lock chamber. The basis for the work was the design of reinforcement using full-threaded prestressing bars and the drawing documentation of the existing condition. The aim of the work was to present the issues associated with the anchoring of the prestressing bars by cohesion in the existing concrete structure, in particular testing on test blocks in the laboratory to verify a suitable solution. Following the data obtained, to perform an analysis and comparison on models solved by nonlinear computation in ATENA Science software. Subsequently, the analysis of the model of the existing condition of the outlet channel section is also carried out by nonlinear calculation with the evaluation of its behaviour to extreme loads. This model is then supplemented with reinforcement using prestressing bars with application of the knowledge associated with the pullout test models. The model of the pre-stressed outlet channel section is thus a simulation of the design on the lock itself.
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Influence of cold water immersion on repeated strength endurance performance in football players
Šíma, Marek ; Jebavý, Radim (advisor) ; Blažek, Dušan (referee)
Title: Influence of immersion in cold water on repeated strength endurance performance in football players Objectives: The aim of this study was to assess the acute effects of cold water immersion on repeated strength endurance performance in the form of 30 maximum vertical jumps in football players. Methods: The effect of immersing the lower limbs to the level of the navel in cold water on repeated strength endurance performance in the form of CMJ (countramovement jump) in football players. Twenty-two football players (men) performed an entry and exit strength endurance test in the form of vertical jumps on the Kistler board. Between the input and output performance tests, two cold water immersion regeneration procedures (CWI) and passive rest (PAS) were applied. For the evaluation of force endurance performance, data on jump height (cm), force impulse (Ns), flight time (ms), speed (m / s), force (N), force / weight (N / kg), power ( W), power / weight (W / Kg). As a marker of fatigue, blood lactate levels (mmol / l) were monitored, we also monitored skin temperature (ř C) during CWI and subjective feeling of fatigue (1-10). The influence of two types of regeneration procedure and two strength endurance performances were evaluated using ANOVA. Results: No statistically or materially significant...
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EMG analysis of lower limb muscles in dependence on growing muscle fatique
Raba, Lukáš ; Hojka, Vladimír (advisor) ; Pánek, David (referee)
Title: EMG analysis of lower limb muscles in dependence on growing muscle fatigue Objectives: The main objective of this thesis is monitor and evaluate changes in EMG parameters of muscles of low extremities depending on the level of local muscle fatigue (during exercise on legpress). Methods: Study included 8 subjects who completed the exercise on weight lifting machine legpress, while we were measuring 6 muscles on lower extremities by using surface EMG. The measuremets was at level 75 % of maximum weight, when probands doing exercises until he had complete muscle fatigue. Data from electromyography was processed and through them we could watched the spectral distribution of the EMG signal and changes of EMG amplitude. Key words: amplitude analysis, spectral analysis, surface polyelectromyography, muscle fatigue
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EMG analysis of lower limb muscles in dependence on growing muscle fatique
Raba, Lukáš ; Hojka, Vladimír (advisor) ; Pánek, David (referee)
Title: EMG analysis of lower limb muscles in dependence on growing muscle fatigue Objectives: The main objective of this thesis is monitor and evaluate changes in EMG parameters of muscles of low extremities depending on the level of local muscle fatigue (during exercise on legpress. Methods: Study included 8 subjects who completed the exercise on weight lifting machine legpress, while we were measuring 6 muscles on lower extremities by using surface EMG. The measuremets was at level 75 % of maximum weight, when probands doing exercises until he had complete muscle fatigue. Data from electromyography was processed and through them we could watched the spectral distribution of the EMG signal and changes of EMG amplitude, which we relate to maximal voluntary contraction. Results: After analysis of all 48 measured muscles, increased of EMG amplitude occured in 45 of them. There was 67 % statistically significant, another 6 % was really close to significant level and remaining 23 % was insignificant. We have 144 time series in analysis of quartile milestones (Q25, Q50 and Q75). From this number decrease of frequency occured 135 times. There was 75 % statistically significant. Then we found out that biggest decreased was in median and mainly in Q75, it was in 82 %. Conclusions: Study proved that during...
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Investigation of composite material degradation indicators using acoustic measurement: comparison with laser vibrometry
Fíla, Tomáš ; Urushadze, Shota ; Kytýř, Daniel ; Valach, Jaroslav ; Šperl, Martin
This paper deals with investigation of acoustic material degradation indicator (attenuation decrement drop of selected natural frequency) measured by a custom-built experimental device. Samples of C/PPS fibre composite material were analyzed. Acoustic signals were recorded and processed using spectral analysis and sound signal regression. Data measured by this method were verified by comparative experiment. Specimens were simultaneously measured using both acoustic experimental device and laser vibrometer. Modal analysis of the specimen were carried out prior to the experiment. This enabled assessment of specimens natural modes and therefore the best impact zone. In total, 10 measurements were performed for each specimen at the same level of degradation. Measured data were then processed and compared. The specimens were repetitively measured after designated number of loading cycles.
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