National Repository of Grey Literature 182 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Numerical estimation of blade displacement due to air excitation
Mekhalfia, Mohammed Lamine ; Procházka, Pavel ; Tchawou Tchuisseu, Eder Batista ; Hodboď, Robert ; Maturkanič, Dušan
For the last few years, vibration measurement has taken an intense interest from research activities. For this reason, this article considers, besides vibration measurements, the impact of air forced excitation on blade motion, displacement and vibration through both simulation analysis and The Transformation of mathematical analysis that explain the interaction between fluid (Air) and the structure (Blade) into numerical setup along with FEM analysis through ANSYS Software. 3D Blade was created to meet the same characteristics of the real blade to enable real environment criteria for the simulation.
Dynamics of a magnetically excited blade: theoretical and experimental analysis
Tchawou Tchuisseu, Eder Batista ; Procházka, Pavel ; Mekhalfia, Mohammed Lamine ; Hodboď, Robert ; Maturkanič, Dušan
This work dealt with the theoretical and experimental analysis of a static blade subjected to a magnetic excitation. The theoretical analysis combines the modeling and design of the blade via ANSYS in whih the modal analysis is done. Both methods showed qualitative agreement of the results.
Accuracy of the analytical methods developed for blade tip-timing analysis
Maturkanič, Dušan ; Procházka, Pavel ; Kozánek, Jan
Within the research of methods for precision solution of rotor blade vibration based on the philosophy of Blade Tip-Timing at the Institute of Thermomechanics AS CR, v.v.i., the effort was concentrated on the decomposition of measured data. This paper describes the accuracy of analytical methods taking into consideration the errors of the measured sensors or the influence of the measurement conditions on the results.
In-situ electron microscopy of graphene growth on metal substrates
Mahel, Vojtěch ; Procházka, Pavel (referee) ; Bukvišová, Kristýna (advisor)
This bachelor thesis aims to get familiar with graphene growth using chemical vapor deposition in a scanning electron microscope chamber. During this reaction, inhomogeneous nucleation occurs, and grain boundaries are formed worsening graphenes' physical properties. Thus graphene is prepared on liquid substrates to improve final quality. The thesis discusses problems with our method in-situ and graphene growth on liquid gold.
Graphene on SiC as a substrate for molecular self-assembly systems
Černá, Lenka ; Průša, Stanislav (referee) ; Procházka, Pavel (advisor)
This bachelor thesis deals with the fabrication and characterization of metal-organic frameworks formed by self-assembly mechanism of metal atoms (Fe) and organic molecules (tetracyanoquinodimethane, TCNQ) on a graphene surface. The fabrication of self-assembled structures has been performed on epitaxial graphene on SiC(0001) substrate. The deposition of metal-organic networks, as well as subsequent surface characterization by low-energy electron microscopy (LEEM) scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS), were performed under ultra-high vacuum conditions.
Detection of experimental minimal disease using PCR
Procházka, Pavel
Title of thesis: Detection of experimental minimal disease using PCR Abstract of thesis: Introduction: Minimal residual disease is a presence of viable tumor cells in the body during or after cancer treatment. These cells can not be detected by usual methods. Diagnosis is based on proof of differences between tumor and healthy cells using very sensitive methods. In experimental medicine, there is a need for detection of human cells in mouse tissues after xenotransplantation. That's why I introduced a sensitive PCR method capable of detecting minimum quantities of human cells in animal tissues. Material: I worked with human lymphocytes, neuroblastoma cell line, cell line derived from Ewing sarcoma, tissue samples from commonly used laboratory animals - mouse, rat, rabbit, monkey, dog, guinea pig and rat brain tissues from the injection site where they were delivered human CD34+ haematopoietic progenitor cells, and tissue from the lesions. Results: I set the sensitivity of PCR method 1:105 using dilution test. In the experiment with various animal's tissue I showed that the method detect only the presence of human DNA. I tried applicability of the method in an experiment of monitoring human CD34+ hematopoietic progenitor cells in mice brains. I proved that CD34+ cells implanted into the brain migrate to the...
Dependence of signal strangth on the radial distance and different types of magnets
Procházka, Pavel ; Voronova, Evgeniya ; Maturkanič, Dušan
The paper describes dependence of signal strength on the radial distance between the sensor and the measured object and dependence of signal strength on the different types of magnets. The measurements were performed in the laboratory of the rotational laser vibrometry originated at the Institute of Thermomechanics AS CR, v.v.i.
Preference and Popularity of Combative Activities among Primary School Pupils in Bohemia and Moravia
Procházka, Pavel ; Dlouhý, Martin (referee)
The thesis deals with the preferences and popularity of individual combative activities of pupils of the second level in selected primary schools in Bohemia and Moravia, the choice of which was determined in relation to the cities' population. It is based on a diploma thesis entitled Preference and Popularity of Combative Activities among Primary School Pupils in the Selected Region. The thesis brings basic information about the developmental specifics of the given age category. In the theoretical part, the reader learns about the knowledge of combative systems. The work also highlights the importance of regular sports in children' lives and in this respect, it points out combative activities as a key element in the development of an active lifestyle. The practical part focuses on an active sports involvement of children in individual combative activities and their interest in them not only in physical education lessons but also beyond them. Moreover, it compares the differences of these preferences among pupils of the second grade across the selected elementary schools in Bohemia and Moravia. Attention is also paid to gender differences. The thesis is recommended for practice and supplementation of existing knowledge in the field of combat activities. It points out their importance in the...
Simple model for investigation of aerodynamic coupling in linear blade cascades
Chládek, Štěpán ; Pešek, Luděk ; Procházka, Pavel
Simple viscous-elastic model has been proposed for investigation of aerodynamic coupling in linear blade cascades. One blade is connected with both adjacent blades using idealized springs and dampers which represent viscous fluid. All blades may oscillate with one degree of freedom represented by vertical translation. Energy method using travelling waves model was utilized for aerodynamic damping coefficient derivation. The proposed model does not compute the damping values quantitatively, nevertheless it provides the damping shape analysis. Interesting results are presented within zero and low subsonic flow velocities, where the experiment included velocity flow field measurement.
A simple algorithm for probes positioning in BTT systems
Tchawou Tchuisseu, Eder Batista ; Procházka, Pavel ; Maturkanič, Dušan
The Blade Tip Timing (BTT), a non-contact method for measuring the blade tip displacement through the time of arrival, is studied in this article. This work proposes a simple algorithm based on the minimization of the coherence and the condition number of the sensingmatrix for defining the best probe positioning in the case of synchronous and asynchronous vibrations.

National Repository of Grey Literature : 182 records found   1 - 10nextend  jump to record:
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