The aim of the present doctoral thesis was to reveal the active deformation mechanisms in novel high strength magnesium (Mg) alloys using advanced in-situ techniques with high time and space resolutions. The deformation behavior of two extruded Mg-LPSO alloys with a different volume fraction of the long-period stacking ordered (LPSO) phase was investigated in tension and compression at room temperature and in compression at 200 řC, 300 řC, and 350 řC. In order to support the results obtained by in-situ acoustic emission and synchrotron diffraction methods, detailed microstructure investigation was provided by transmission and scanning electron microscopy, particularly the backscattered electron imaging and electron backscatter diffraction technique were used. The results indicate that both temperature and the LPSO phase content significantly influence the plasticity of the magnesium matrix, particularly they affect the activation of extension twins and non-basal slip. Moreover, both parameters have a high impact on the formation of the deformation kinks in the LPSO phase. Keywords: Mg-LPSO alloys, deformation mechanisms, acoustic emission, synchrotron diffraction, in-situ methods.

Bibliographical record: KOLÁŘ, J. The Use of Hearing Perception Elimination in Motoric Activity. Prague: Charles University, 2nd Faculty of Medicine, Department of Rehabilitation and Sports Medicine 2020. 79 p. Thesis supervisor prof. PaedDr. Pavel Kolář, Ph.D. Abstract This thesis focuses on the importance and significance of human senses - especially hearing and vision - in connection with a performance of a motor activity. The theoretical part brings a summary of knowledge about the influence of hearing and vision on human movements and the induction of changes in the body during the elimination (deprivation) of some of the senses. Furthermore, in this part we briefly inform about the mutual relationship between vision and hearing, ideomotor functions, an auditory deprivation and lastly, we try to point out the possibilities and importance of a neuro-visual complex therapy. The main goal of the practical part is to prove the influence of hearing on the motor expression of the tested probands. A secondary goal of the practical part is to determine the influence of the quality of a visual perception on a motor expression and whether there can be an immediate intensification of a visual perception during auditory deprivation. Methodology: As a part of the main goal of the practical part, we tested 77...

In this present work, the dynamics of deformation mechanisms activated in binary magnesium-gadolinium alloys with respect to amount of Gd were investigated with in-situ experimental methods. Cast alloys are characterized by random texture. Compression test were done at room temperature with simultaneous record of acoustic emission response. The acoustic emission signal was subsequently analysed using advanced clustering method providing information about the dominant deformation mechanisms. High speed camera was used to study the dynamics of twinning, including estimation of the velocity of twin propagation with respect to Gd concentration. The deformation tests were repeated in a chamber of scanning electron microscope (in-situ SEM) with concurrent following the microstructure development using secondary electrons and electron back-scattered diffraction (EBSD) in different stages of the deformation. Main goal of this measurements was to identify active slip systems and the progress of twin volume fraction during deformation. Keywords: magnesium alloy, deformation tests, acoustic emission, high-speed camera, electron microscopy, twinning

More and more attention of scientists and artists is paid to the effect of sound to human and ecosystems. Due to technology development and growing urgency of human impact new approaches are being formed. This thesis is based on concepts of acoustics ecology by R. M. Schafer. In addition to noise mapping, Czech geographical research does not reflect the growing urgency of sound environment issues. In this thesis I present terminology, concepts and some methods which are used in acoustic ecology or soundscape ecology. A literature search shows the application of these terminology, concepts and methods in a geographical research, specifically in urban and landscape planning, geography of tourism, leisure, health geography or landscape ecology. In an empirical part I followed a pioneering idea of acoustic landscape typology. I used qualitative research, listening walk and narrative conversation, to obtain data about soundscapes. Through these data I critically evaluated and compared acoustic typology of landscape by Hendrych and Hynek (2008). I used recording of soundscapes and spectrograms as secondary methods. Recordings and spectrograms are availabled in ArcGIS Online application. I found out the typology according to Hendrych and Hynek appropriately describes soundscapes from the perspective of...

The presented dissertation thesis deals with a simulation of the human phonation in terms of latest theories. Phonation is considered here as a bi-directional fluid-structure-acoustic interaction, where the interaction between all three physical domains occurs due to the unsteady viscous compressible Navier-Stokes equations. There is a solid knowledge background in the first part of the thesis. It concerns the latest concepts in computational modeling of the human phonation, the most important and recent theories about the human voice production and some key aspects of the human anatomy, physiology and pathology. Also voice assessment is discussed. The second part of the thesis describes an in-depth analysis of a phonation simulation in a planar computational model. The basic concepts proceed from algorithms developed in the Institute of Solid Mechanics, Mechatronics and Biomechanics. Created models are able to reproduce sounds of all Czech vowels and the most common evaluated parameters very close to physiological ranges. The simulated pathology, Reinke's edema, is demonstrated in order to explore its influence on the vowel sound. The third part focuses on modeling of phonation in a spatial computational model. All Czech vowels are simulated also here and compared to the planar model and to actual measurement. The spatial model serves as the starting point to modeling of a longitudinal pretension incorporated in the vocal folds. In the last part of the thesis, a modeling of the phonation with vocal folds pretension is investigated. Although the models are tuned to a rather soft phonation, the results are in agreement with the relevant physiologic phenomena. While the spatial model is highly computationally expensive, a hybrid planar model with pretension is proposed. A special attention is paid to the analysis of self-sustained oscillation of the vocal folds. It is shown, the planar model cannot reproduce such kind of oscillation in the actual version, albeit time of oscillation was considerably extended. On the other hand, oscillation of the spatial vocal folds are stabilized without effects accompanying subduing of oscillation. It can be supposed that the spatial model is able to reproduce self-sustained oscillation as a basic principle present during the human phonation.

The thesis deals with the application of nondestructive testing methods (acoustic emission, electron microscopy, X-ray diffraction topography) to description and identification of stages in the fatigue process in aluminium alloys. The main contribution of this dissertation thesis consists of the approach and evaluation methodology of cyclic damage in the materials. It dealt especially with the verification of measured data by using data obtained using other nondestructive methods. The experimental results show that the field of nondestructive testing materials can fundamentally uncover the process of fatigue damage and improve current knowledge in this area. Combination of used methods has become a powerful tool for the identification and monitoring of the whole fatigue degradation process of materials.

Birdsong is one of the most astounding natural sounds which profoundly shaped our evolutionary thinking since the 19th century. Despite a strong interest in birdsong for over 100 years, our understanding of birdsong ecology and evolution over large spatial and phylogenetic scales is still very fragmentary. Answering many basic questions requires a global synthesis covering vast diversity of extant bird species and adoption of multidisciplinary approaches. In presented dissertation thesis, my co-workers and I have explored important patterns in macroecology and macroevolution of song in passerines (Order: Passeriformes), the most diverse and widespread bird order. We have focused on three key song phenomena: (1) song complexity, (2) song frequency and (3) the presence of song in female birds. We have exploited birdsong "big data" available on public citizen science databases and other open sources in order to fill several important gaps in the current knowledge. These data were analysed by a combination of phylogenetically-informed cross-species analyses and spatial macroecological approaches. Since the publication of Darwin's seminal work, elaborated songs are generally agreed to be the result of sexual selection. We developed a simple but reliable song complexity metric to explore a global diversity in...

The subject of the diploma thesis is the design and the assessment of two variants of existing HVAC system, that serves the microelectronic laboratory premises of GL Electronic company, which are situated in JIC INMEC center. The aim of the designing process is to find the optimal solution of the problem, which is concerned of excessive air humidity gains in the clean rooms. The first proposed approach is the installation of controlled dehumidification in the form of direct cooling into the yet existing device. The second considered approach is a complete deconstruction of implemented air conditioning unit and subsequent reinstalling of the brand new unit, which would meet all the requirements. Both two variants will be in the beginning outlined in a form of pre-study, selected option will be later on processed as project documentation for construction. The winning solution will be designed in the way that will satisfie the criteria of hygiene, function, and economy. The next section of the text will be dedicated to the research regarding the topic of the physical nature of air humidity, of the transportation of humidity, dehumidification of the space, also. Last but not least, the heat recovery efficiency will be measured (in the form of thermal glycol tubes). The experiment provides evidence of the system's real-time performance.

Near-field acoustical holography is a standard method for sound source visualization and localization. In this thesis, commonly used and newly published near-field acoustic holography methods are introduced and analysed. In addition, regularization methods are presented together with finding options of optimal regularization parameter. Based on theory, a LabVIEW library is built containing four implemented near-field acoustical holography algorithms and two regularization methods. To verify the correctness of implementations, a testing application has been made. This application allows testing of implemented algorithms with simulated or experimentally measured data. The correctness of implementation is verified, and algorithms are compared to each other with respect to accuracy and speed of calculation.

This diploma thesis deals with the spectrum analysis, frequency characteristics, Chladni figures and simulation of modal and harmonic analysis of an acoustic guitar in ANSYS program interface. In the acoustic guitar analysis, various details that can influence the instrument spectrum are discussed. Especially on its performance over time, the number of generated harmonic components and their performance. Then the guitar bracing innovation of the dreadnought guitar was created from the measured, simulated and calculated data. Four acoustic guitars with the innovation were then made. These innovated instruments were further analyzed and compared with the acoustic guitar before the innovation and with a competitor’s guitar. Furthermore, the thesis describes parts of an acoustic guitar, wood properties, theoretical background and measurement methods.