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The use of bioimpedance analysis for kidney function evaluation
Veselková, Alena ; Šrámek, Petr (advisor) ; Švára, František (referee)
Objective: To calculate glomerular filtration (GF) through the use six available methods to estimate GF and measure impedance parameters phase angle () and fat free mass (FFM) by using multifrequency and monofrequency measurement. Select one method of estimating GF as a strict method of estimation GF for this study and by using linear regression relate with other method of estimating GF and impedance parameters measured () and FFM. Consider if () and FFM are significant parameters to improve methods of estimating GF given below (MDRD-A, MDRD-B, CLCG, CLcysC). (...) Conclusions: Impedance parameters () and FFM correlate with GF, decreasing GF cause decreasing of these impedance parameters. This study proved very close relationship between parameters FFMx and FFMc, obtained by using two different kinds of measuring (R2 - FFMx and FFMc = 0,843). Method of bioimpedance is ready to other validation and to develope bioimpedance scale to estimate renal function.
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Propagation of inclined cracks to the interface of ceramic laminates
Novotná, Lenka ; Trunec, Martin (referee) ; Chlup, Zdeněk (advisor)
Composite materials with laminated structure provide advantages which are utilised during component design. Low density, temperature and chemical stability are the profitable properties predetermining application of ceramic laminates. The main obstacle for wide spread of ceramic materials is their inherent brittleness. Therefore, in this thesis, the crack propagation in ceramics laminates has been extensively studied. Laminated structures with various volume fractions of components (alumina and zirconia) were prepared by electrophoretic deposition. Evaluation of crack propagation through the interface and determination of basic mechanical properties was conducted on the basis of extensive literature search. Crack deflection originated in both presence of internal stresses and differences in elastic modulus during the crack interface passing was monitored. A special type of specimen geometry was employed with the aim to set arbitrary angle between crack and interface. It was experimentally found that the degree of crack deflection is dependent on entering angle and volume fraction of components. Higher crack deflection was already found in the bulk of the test piece comparing to the test piece surface. The 3D fracture surface reconstruction generated using laser confocal microscopy was used in this detailed crack propagation study. Further basic elastic and strength characteristics of laminates were determined and compared to those obtained from monolithic materials. The validity of the mix rule for elastic characteristics was confirmed by comparing of elastics modulus. The most reliable method for elastic modulus determination was marked the dynamic resonance method due to low scatter and consistency in measurement. The flexural strength of all laminates tends to be close to the flexural strength of the weakest component. Therefore the mix rule is not applicable for flexural strength estimation on the contrary of elastic characteristics. The change of component volume fraction leads only to change of flexural strength scatter. Thanks to gained knowledge about crack propagation and basic characteristic determination will be possible to design ceramic laminates more efficiently for given needs of application.
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Analysis and modification of thin layers using ion beams
Jonner, Jakub ; Lörinčík, Jan (referee) ; Bábor, Petr (advisor)
This diploma thesis deals with analysis and modification of thin layers using ion beams. The first part of this diploma thesis deals with phenomena accompanying ion beam bombardment of solid matter. The second part of this diploma thesis is concerned with Secondary Ion Mass Spectroscopy (SIMS) and Low Energy Ion Scattering (LAIS). This work convey some basic information about these two techniques and it also deals with some benefits result in their connection into parallel depth profiling mode (such as better depth resolution of the LEIS profile, quantification of the SIMS). These benefits are demonstrated on MoSi film measurement. Within the framework of this thesis a new UHV manipulator was designed. This new UHV manipulator is equipped with precise stepper UHV motor and since the proportions are smaller, the manipulation with a sample in a space limited UHV chamber is much more comfortable and more precise. The third part of this diploma thesis deals with ion-beam induced transformation of epitaxially grown Fe films with thickness of 22 monolayer (ML) and 44 ML on Cu(100) single crystal at room temperature. Metastable Fe films of 22 ML thickness were prepared in CO pressure and 44 ML Fe films were prepared by co-evaporation of Fe with Fe64Ni36 (invar). Structural changes are analyzed by scanning tunneling microscopy and low-energy electron diffraction. The aim of this thesis is to discuss the influence of the sputtering parameters such as ion dose and ion energy on the nucleation of bcc nanocrystals, their growth, final shape and size. The influence of different Ni concentration on stability of 44 ML thick Fe films is also discussed.
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Optical Scanners - Suspension Kinematics Points Measurement
Souček, Ondřej ; Hejtmánek, Petr (referee) ; Blaťák, Ondřej (advisor)
The master´s thesis deals with creating a usable methodology for measuring the position of kinematic points McPherson suspension using optical scanners available on ÚADI. The answer lies in comparing the measurement results obtained using the scanners ATOS and TRITOP with regard to the different measurement methods. Using analytic geometry and the software ADAMS are fixed characteristics of the suspension, they are compared with values measured on the geometry. Finally, it evaluated the accuracy of measurement methods.
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Comparison of quantitative LIBS analysis of steel standards utilizing single-pulse and double-pulse LIBS
Pořízka, Pavel ; Hrdlička, Aleš (referee) ; Kaiser, Jozef (advisor)
In this diploma thesis the differences between single pulse and double pulse laser induced breakdown spectroscopy (LIBS) methods are discussed. The time evolution of laser induced plasma (LIP) parameters, such electron density, plasma temperature, density of ions and atoms is shown. Selected methods for evaluation of plasma parameters (Boltzmann equation, Saha-Boltzmann equation etc.) are also stated. The theoretical bases of local thermodynamic equilibrium (LTE), which is necessary condition for using of previously stated methods for computation of plasma parameters, are discussed. Diploma thesis also contains the description of each component of our LIBS experimental set up and the way of their optimization. Presented theoretical advantages of DP LIBS method are demonstrated on results of experimental measurements of steel standards.
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Localized Surface Plasmons: Principles and Application
Kvapil, Michal ; Schmidt, Eduard (referee) ; Šikola, Tomáš (advisor)
The diploma thesis deals with plasmonic nanostructures for visible eventually near-infrared region of electromagnetic spectrum. At first, there are discussed basic terms which are necessary for description of plasmonic nanostructures and their properties. Then the resonant properties of gold nanoantennas on a fused silica substrate and in proximity of nanocrystalline diamond are addressed. FDTD simulations are used for an assesment of resonant properties and local electric field enhancement of these nanostructures. Possible manufacturing methods of the antennas and techniques for the measurement of their properties are mentioned at the end of the thesis.
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