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Dependence of Thermal Plasma Flow Velocity on Arc Current Determined by Correlation Analysis of Optical Records
Gruber, Jan ; Šonský, Jiří ; Hlína, Jan
Optical radiation of thermal plasma jet was recorded in two parallel cross-sections perpendicular to the jet axis and separated by 3.5 mm. Sufficient sampling rate was a prerequisite to obtain detectable shift between the time-series recorded in closer and farther cross-sections. We have determined time lags between the recorded signals both in the core and boundary regions by correlation analysis and subsequently determined associated velocities of plasma flow. Arc current was gradually increased in respective measurements, gas flow was fixed. Determined flow velocities are in the range 140 m/s - 280 m/s in the jet core and 110 m/s – 220 m/s in the boundary region. This is in agreement with the results obtained for similar plasma torches by other methods in the past. Velocity increases with arc current almost linearly and this dependence and velocity profile in the plasma jet cross-section are presented in this paper.
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Calculation of residual fatigue life of railway set
Náhlík, Luboš ; Hutař, Pavel ; Knésl, Zdeněk ; Matušek, P.
The calculation of residual fatigue life of railway set is described in the contribution. The initial defect is modeled as a semicircular crack, which propagates preferentially in normal mode of loading perpendicularly on the axis of the axle. The conservative approach based on linear elastic fracture mechanics was chosen for residual fatigue life prediction. The aim of calculation is to determine number of loading cycles, which permits safe run of the railway axle, i.e. the dependence of crack depth on number of loading cycles for given loading spectrum.
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Reliability assessment of bodies with general singular stress concentrator
Klusák, Jan
The paper presents a method leading to reliability assessment of bodies with general singular stress concentrator. The method uses combination of analytical and numerical procedures to determine fracture-mechanics parameters. The approach is based on comparison of fracture behaviour of body with a crack and a body with a general singular stress concentrator. The goal of the paper is to determine value of applied stress that leads to initiation of failure of construction.
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Cryotherapy as the oppurtunity for the regeneration of sportsmen
Počtová, Bohumila ; Nováková, Pavlína (advisor) ; Majorová, Simona (referee)
Title ofthesis : Cryotherapy is oppurtunity for the regeneration ofsportsmen Goal of the project : To map and compare information of c:ryotherapy center and places that provide c:ryotherapy application in the Czech Republic. Ifthere is a regulary and properly train information of cold effect for body and prove to provide. On the basis ofthis is determination the quality of information giving to clients and experience ofsportsmen clients at information about influence of cold and this procedure. To find out how the method is used and whether are conditions an fulfiled. Metb.ods :For research I use an exploratory method.The collection of dates was executed by public inguiry and guestionnaires PO:tv1S. The getting dates of particular items was evaluated by qualitative method. Results : This reseach charted cryotherapy centres in the Czech Republic. There was established professional skill specialists served in each of all questionnairy cryotherapy centres. However safety ofthe clients is provided in part only. The clients should have to udergo medical examinations. But these ones are not realised in some of them. The results of this rescach ís cryotherapy centres and sportsmen are deficienty ínformation. The results ofquestionnaires POMS cenfirmed players feelings are posítive after cold application....
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Assessment of aromatic compounds with allergenic effect
Obrdlíková, Blanka ; Sůkalová, Kateřina (referee) ; Vítová, Eva (advisor)
The thesis deals with the determination of allergenic fragrances in cosmetics. The theoretical part is focused on the description of cosmetic products, the use of fragrances in the preparation of cosmetics, obtaining fragrances and their allergenic effects on the human body. In the practical part the SPME-GC-FID method is used for the determination of aromatic substances with allergenic potential in selected cosmetic products (natural creams and toilet water).
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Iterative generation of sine and cosine signal by finite word length
Štursa, Jarmil
The iterative procedure of sine/cosine signal generation operates without the need of any ROM table. A special attention is given to the correct determination of initial conditions of the iteration process and to finite word length of some system factors. The program environment Matlab is used for the simulation of this process. The level of normalized errors of iteratively generated sine and cosine signal is investigated.
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Analysis of the company environment
Hladík, Ondřej ; Dvořáček, Jiří (advisor) ; Strouhal, Jiří (referee)
This bachelor thesis deals with methods of analysing the company environment and then using these methods on a company Travel Service, a.s. The primary purpose is to determine main factors affecting the market position of this company. Methods used for analyzing the company environment are introduced in theoretical part of the thesis. For analysing the macroenvironment is used PEST analysis and Porter five force model is used for analysing the critical factors of macroenvironment. The thesis include SWOT analysis and recommendations for the company based on the collected informations.
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Measurement of intermodal dispersion in a twin-core optical fibre
Peterka, Pavel ; Kaňka, Jiří ; Honzátko, Pavel
The intermodal dispersion (IMD), that arises from the difference of group delays of the two fundamental modes of the twin-core fibre (TCF), could have a detrimental effect for usage of TCF in high-speed applications. Therefore, its accurate determination is of a high interest. We have estimated the IMD from the fibre refractive index profile and we have determined it from the interference pattern in spectral domain and from the repetition rate of passively mode-locked fibre laser incorporating TCF.
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Stimulation of the zones used during reflex locomotion by TENS
Vodňanská, Markéta ; Malá, Jitka (advisor) ; Pánek, David (referee)
Thesis title: Stimulation of the zones used during reflex lokomotion by the TENS Name: Markéta Vodňanská The aim of the thesis: The aim of this thesis is to determine, whether is activated the appropriate locomotor pattern during Vojta reflex locomotion - reflexive crawling, when TENS is used for a stimulation of trigger zones, as it is during manual stimulation of trigger zones for reflexive crawling. Method: The essence of this study is the stimulation of trigger zones used in the reflex locomotion manually and by transcutaneous electrical nerve stimulation (TENS) at a frequency of 30 Hz and 182 Hz. Six probands participated in this experiment. During the manual and TENS stimulation was scanned electrical activity in selected muscles by surface electromyography. First, it was evaluated the order of activation of selected muscles, using "standard timing" analysis by MyoResearch XP Master program. Second, it was evaluated the crawling reflex locomotion pattern visually. Results: It was confirmed, that the crawling reflex locomotion pattern, which is provoked by manual stimulation of trigger zones, is provoked by TENS stimulation as well, using the same trigger zones. It follows that the vector of direction and pressure during manual stimulation of trigger zones is not necessary for recall of the...
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