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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Vlastnosti povlaků řezných nástrojů ze slinutého karbidu / Coating properties of cutting tools carbide

Doležalová, Petra January 2013 (has links)
Diploma thesis is divided into two parts. The first part is focused on theoretical description of coating methods, on currently used coatings, their properties and it is also focused on description of methods, which are used for analyzing each property. The second part focuses on testing of coatings and analyzing of the values obtained from experiments. The aim of this thesis is then to compare the properties of the tested coatings.
52

Vliv prvků aktivní bezpečnosti vozidel na prevenci dopravních nehod / Effect of Active Vehicle Safety in the Prevention of Road Accidents

Franc, Šimon January 2013 (has links)
This diploma thesis focuses on effects of active vehicle safety on the prevention of traffic accidents. In the introductory section, the term of active safety is defined and divided into four categories. In next four chapters, the particular elements of active safety are described in more detail and some selected elements are described in depth. Chapter seven includes a questionnaire; it enquires opinions of people about some of the elements of active safety. Practical road tests were conducted as part of this work. Theirs description and evaluation are in the last chapters.
53

Povrchová topografie a mechanické vlastnosti tenkých vrstev na bázi tetravinylsilanu / Surface topography and mechanical properties of thin films on tetravinylsilane basis

Plichta, Tomáš January 2016 (has links)
Proposed diploma thesis is focused on preparation and characterization of the plasma polymer thin films based on tetravinylsilane monomer (TVS). Plasma enhanced chemical vapour deposition (PECVD) method involving pulse and continual plasma discharge modes were used for thin film deposition on silicon wafer pieces. Reactive plasma composition was containing pure TVS or mixtures of TVS and argon or oxygen gas. Atomic force microscopy was used for surface topography and roughness characterization. Cyclic nanoindentation was involved to measurements to determine the Young’s modulus and hardness of prepared films and scratch test was performed to evaluate the degree of adhesion. Special attention was drawn to the characterization of films with a Young’s modulus below 10 GPa. Tip geometry of indenter influence on scratch test was also commented. Surface and mechanical properties of thin films in relation to the deposition conditions were correlated to the obtained results and final analysis of deposition conditions influence is proposed.
54

Jízdní dynamika traktoru / Driving dynamics of a tractor

Renza, Jaroslav January 2016 (has links)
This thesis analyses driving dynamics of tractors and its dependence on their weight and age. In the beginning, brief history of tractor development and definition of basic concept of the tractor analysis is described. The thesis states procedures for obtaining magnitudes necessary for determining of driving dynamics. Experimental part describes the realized measurement on chosen sample of tractors and interprets measured values. Last part of the thesis contains evaluation of the measurement results.
55

Studium přírodního a vytvoření umělého nanostrukturovaného povrchu gekona / Study of gecko adhesion force and formation of a nanostructured gecko mimicking surface

Vyskočilová, Marta January 2016 (has links)
This thesis deals with the surface of a gecko in relation to its adhesion ability. Understanding the mechanism of movement and adhesion principle is important for the design and manufacture of nanostructured material. Likewise, knowledge of the origin of the self-cleaning ability allows the description of the influence of surface structure on movement and forces acting at the contact. The work describes the process of making nanostructured surface, which was modified in order to obtain maximum adhesion forces. The material properties were determined by the values of wettability and by force spectrum measurement. Their results were compared with the theoretical assumption of capillary forces and other possibilities to increase adhesion.
56

Povrchové úpravy skleněných vláken pro polymerní kompozity / Surface modification of glass fibers for polymer composites

Knob, Antonín January 2016 (has links)
The doctoral thesis is aimed at preparation of glass fiber reinforced polymer composites with controlled interphase formed by plasma-polymerized tetravinylsilane and tetravinylsilane/oxygen thin films. The thin polymer films of specific physico-chemical properties and thickness were deposited to improve interfacial adhesion of glass fiber/polyester composites. The fiber surface modification was performed by using plasma enhanced chemical vapor deposition in low-temperature RF plasma operating in an various effective power range and different treatment time. Test results were examined in relation to the interlayer thickness and different treatment conditions. The prepared interlayers were analyzed to evaluate physico-chemical composition and properties (XPS, RBS, ERDA, FTIR and spectroscopic elipsometry). Selected mechanical properties were evaluated by AFM. Mechanical response of plasma interlayers was evaluated by short beam shear test and direct method of testing the interfacial shear strength using microindentation. The interphase shear failure was controlled by the shear strength at the interlayer/fiber interface as follows from experimental and model data.
57

Vliv uhlíkových nanostruktur na chování lidských buněk a význam fetálního bovinního séra během buněčné adheze / The effect of carbon nanostructures on human cell behavior and the role of fetal bovine serum in cell adhesion

Verdánová, Martina January 2016 (has links)
Graphene (G) and nanocrystalline diamond (NCD) are carbon allotropes and promising nanomaterials with an excellent combination of their properties, such as high mechanical strength, electrical and thermal conductivity, possibility of functionalization and very high surface area to volume ratio. For these reasons, G and NCD are employed next to electronics in biomedical applications, including implant coating, drug and gene delivery and biosensing. For a fundamental characterization of cell behavior on G and NCD, we studied osteoblast adhesion and proliferation on differently treated G and NCD. Generally, both G and NCD exhibited better properties for osteoblast cultivation than control tissue culture polystyrene. Better cell adhesion but lower cell proliferation were observed on NCD compared to G. The most surprising finding was that hydrophobic G with nanowrinkled topography enhanced cell proliferation extensively, in comparison to hydrophilic and flat G and both NCDs (hydrophobic and hydrophilic) with slightly higher roughness. Promoted cell proliferation enables faster cell colonization of G and NCD substrates, meaning faster new tissue formation which is beneficial in biomedical applications. Furthermore, it was shown that osteoblast adhesion was promoted in the initial absence of fetal bovine...
58

Role adheze plazmatické membrány k buněčné stěně ve vývoji a funkci kořenového systému / The role of adhesion of the plasma membrane to the cell wall in the development and function of the root system

Králíková, Dagmar January 2019 (has links)
Adhesion between the plasma membrane and the cell wall and the existence of the continuum of these two compartments is needed for signal transmission, e.g. under pathogen attack, during cell expansion and cell wall growth, or in response to environmental conditions. This adhesion is, in addition to the turgor, provided by physical connection of both compartments. One of the best-known examples of physical connection is found in the root system, in the Caspary strip region, where it is required to maintain apoplastic barriers of the root system, even under adverse conditions and consequent plasmolysis. There is little information about the physical interconnection and the participating macromolecules but there are candidates, which could participate in this interaction. The diploma thesis deals with arabinogalactan (AGP) proteins with fasciclin-like domain (namely FLA9 and FLA2). These proteins may play a role in the adhesion of plasma membrane and cell wall and may be involved in the growth regulation and development of the root system. Both genes are are relatively strongly expressed in the roots, especially in the elongation zone and in the cortex, including the endodermis (according to chip data). Also, to a smaller extent, the thesis deals with integrin-like At14A protein. The most interesting...
59

Vývoj lepicí hmoty pro instalaci čedičových prvků na silikátový podklad v náročných expozičních podmínkách / Development of adhesive material for the installation of basalt elements on silicate foundations under severe exposure conditions

Bergerová, Kamila January 2019 (has links)
The diploma thesis deals with research and subsequent development of a new adhesive material for the installation of nonabsorbent basalt elements on silicate foundations under severe exposure conditions. For commercially produced tile adhesives, only primary raw materials are used as fillers. The purpose of this work is to evaluate the possibility of utilization of secondary raw materials as fillers in the tile adhesive. The thesis is mainly focused on the durability of these materials after exposure to the aggressive environment.
60

Analýza dynamických interakcí těl axonů a jejich biofyzikální modelování. / Analysis of dynamical interactions of axon shafts and their biopysical modelling.

Šmít, Daniel January 2017 (has links)
in English While axon fasciculation plays a key role in the development of neural networks, very lit- tle is known about its dynamics and the underlying biophysical mechanisms. In a model system composed of neurons grown ex vivo from explants of embryonic mouse olfactory epithelia, we observed that axons dynamically interact with each other through their shafts, leading to zippering and unzippering behaviour that regulates their fasciculation. Taking advantage of this new preparation suitable for studying such interactions, we carried out a detailed biophysical analysis of zippering, occurring either spontaneously or induced by micromanipulations and pharmacological treatments. We show that zippering arises from the competition of axon-axon adhesion and me- chanical tension in the axons. This is upheld on quantitative level by conforming change of network global structure in response to various pharmacological treatments, without active involvement of growth cones. The calibrated manipulations of interacting shafts provide qualitative support for the hypothesis, and also allow us to quantify the mechan- ical tension of axons in our system. Furthermore, we introduce a biophysical model of the zippering dynamics, which efficiently serves the purpose of estimating the magnitude of remaining involved...

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