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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.
61

Povrchová úprava stavebně-truhlářských výrobků s krátkou životnosti

Suchý, Michal January 2015 (has links)
This diploma thesis deals with the design system of finishing of structural wood construction with a short lifetime and performing tests of physical and mechanical properties. The system of finishing is based on the used adhesives. Three different kinds of adhesives (UF, MUF, PVAc) were used to test. Tests were conducted by technical standards ČSN, EN, ISO and BS. The aim of the study was to determine the properties and durability of the proposed surface treatment and to evaluate the possibility of using it for practice. Tests were conducted: surface hardness, adhesion to substrates, resistance to scratching, to steam, cold liquid, falling steel ball, abrasion and attrition. Furthermore, the measured sheen, color changes and light fastness.
62

Využití inovativních sorbentů při imobilizaci Zn v půdě / The use of inovative sorbents for immobilization of Zn in soil

Řečínská, Magdalena Unknown Date (has links)
Amorphous manganese oxide has been already successfully tested as an efficient amendment for limiting the mobile fraction of risk elements in soil. However, its application is accompanied with an unsolicited phenomenon of increased dissolution of this agent related to oxidation of soil organic matter. For that reason, surface modification of the studied Mn oxide with the layer of MnCO3 has been proposed (Sm-AMO). The subject of this thesis is to assess the effectiveness of chemical stabilization of two contaminated soils using Sm-AMO with a focus on Zn and to verify the stability Sm-AMO based on laboratory experiments. The results of preliminary stability testing of both materials in demineralized water confirmed that Sm-AMO is less soluble than the original AMO. However, this fact was not confirmed by the results of testing of AMO and Sm-AMO performed using pH-static leaching experiments, when no differences were observed between AMO and Sm-AMO stability based statistical analysis, except for the natural pH (6.03) in the Litavka soil (soil L). Both sorbents yielded greater stability with increasing pH. Adsorption kinetics of Pb, Zn, Cd and As, which are present in the tested soils, onto AMO and Sm-AMO was studied to compare the adsorption properties of both materials. Affinity of these metals was generally higher towards AMO, but the recorded equilibrium time was similar for both sorbents. The results of adsorption kinetics for both materials tested showed the highest sorption rate and the highest adsorbed amount for Pb and the lowest for Zn. Similar results were also observed at pH-static leaching experiment. Stabilization effectiveness of Sm-AMO compared to AMO was mainly demonstrated for Pb and As under natural pH conditions (pH 6,03 and 6,43) of Litavka and Smolotely soils. Considering the stabilization of Zn statistically significant stabilizing effect of AMO/Sm-AMO was observed only at pH 8, when the AMO showed to be more effective. The effectiveness of Sm-AMO for the immobilization of Zn was not as significant as expected, but compared with other immobilization amendments Sm-AMO is an effective sorbent for Zn stabilization.
63

Pigmentové povrchové úpravy ve vysokém lesku vodou ředitelnými nátěrovými hmotami

Vávra, Lukáš January 2016 (has links)
The diploma thesis is focused on the comparison of the influence two-component and one-component waterborne base coatings on the quality of pigmented finished surface in high gloss. There are analyzed requirements for the mentioned surface treatment and applied coatings in the thesis. Samples preparation, depending on base coating and base material used and determination of the physical-mechanical, chemical and optical properties are indispensable part of the diploma thesis. The selected base coatings are compared with each other and with commonly used polyester and polyurethane coatings.
64

Variabilní sedací prvek do veřejného prostoru

Vašut, Jan January 2016 (has links)
A description of this thesis can be presented as the design of variable seating elements in two dimensional versions. Each element is intended for short-term seating in public interiors. The first section of the thesis is focused on the research and theory related to the design of seating furniture, while the second section examines the practical elements which make up the creation of a design from initial idea, sketches, and visualization, on to material selection and the final design.
65

Elektromyografická analýza vzájemného vlivu stoje a stereotypu pohybu v pletenci ramenním / Electromyographic analyis of mutual relation between standing and movement pattern in shoulder girdle.

Konečná, Gabriela January 2018 (has links)
Title: Electromyographic analysis of mutual relation between standing and movement pattern in shoulder girdle Objectives: This thesis examines the electric activity and recruitment (timing) of m. latissimus dorsi, m. obliquus externus abdominis, m. gluteus maximus, m. tensor fasciae latae, m. tibialis anterior, m. erector spinae and m. trapezius during shoulder girdle movement standing on both feet, ipsilateral or contralateral foot. Furthermore the thesis explores whether it is possible to objectify the existence of published tendomuscular chains or the whole hypothetic Latissimus dorsi muscle chain of Spiral stabilization concept using surface electromyography. Methods: The muscles mentioned above were measured bilaterally with surface electromyography electrodes during particular movements. Twelve healthy individuals participated, seven women and five men in the age of 23 - 30. All participants were instructed to do the specific movement from Spiral Stabilization concept against the 2kg resistence of elastic rope when standing on both feet or in one leg stand on contralateral or ipsilateral leg. Results: We can identify muscles that are active in the particular movements almost within all participants, that are activated less often and those that are involved rarely. But we are not able to...
66

Srážkově - odtokové parametry vybraných povodí Stropnice / Rainfall - runoff parameters selected basin Stropnice

FRAŇKOVÁ, Diana January 2010 (has links)
Dissertation work rainfall-drainage parameters on chosen river-basin Stropnice is dealing with measurement of drainage value of surface water on five specific profiles in the area of Horní Stropnice. The goal was discovery and analysis of information on the river-basin Bedřichovský, Pasecký and Váckový stream, Humenická dam and in closure profile at Tomkův mill in the years 2007 {--} 2010, where there were monitoring heights of water level. After substitution into discharge-rating curve were scoring flow rate for individual parts of river-basins and examination of influence Humenická dam on flow rate wave in the closure profile. Between the upper specific profiles of individual streams above Humenická dam and specific profile by the Tomkův mill there was not found any influence of Humenická dam on flow wave in the river basin of Stropnice.
67

Optická charakterizace transportu náboje v polovodičových detektorech záření / Charge transport optical characterization in semiconductor radiation detectors

Ridzoňová, Katarína January 2016 (has links)
Measurements of DC photocurrent-voltage characteristic, photocurrents spectral response and laser induced transient current technique enable investigation of surface recombination centers, bulk trap levels and distribution of the inner electric field. In the presented work, the n- type planar CdZnTe detectors with quasi Ohmic contacts were studied by above mentioned methods. It has been shown that in the case of strongly absorbed light under the DC regime of illumination not only surface recombination influences the detector's transport properties. The effect of the space charge, created as a consequence of carriers trapped by the impurity levels, must be taken into account. Therefore some new theoretical models were created in order to describe measured photocurrent-voltage dependencies. Obtained data were fitted with the new theory and the mobility and surface recombination velocity for electrons were determined.
68

Vliv typu aktivátoru na reologii a povrchovou chemii alkalicky aktivované strusky / Effect of activator nature on rheology and surface chemistry of alkali-activated slag

Russkykh, Kostyantyn January 2021 (has links)
V této závěrečné práci bylo popsáno časné reologické chování alkalicky aktivované strusky, anorganického materiálu, který vzniká aktivací mleté granulované vysokopecní strusky alkalickým roztokem. Vliv typu aktivačního roztoku (hydroxidů, křemičitanů a uhličitanů) a jeho koncentrace na časné reologické parametry byl zkoumán pomocí amplitudových oscilačních měření. Bylo pozorováno, že typ aktivátoru je hlavním faktorem ovlivňujícím reologické chování alkalicky aktivované strusky. Dále bylo pozorováno, že aktivátory na bázi draslíku vedou ke slabší struktuře (nižší mez kluzu, mez toku a nižší hodnoty viskoelastických modulů) oproti použití aktivátorů na bázi sodíku. To lze vysvětlit rozdíly ve velikosti alkalických iontů. Na rozdíl od ostatních aktivátorů křemičitany způsobovaly zvýšení ztrátového faktoru, přičemž vykazovaly spíše kapalné chování. Z výsledků vyplynulo, že většina aktivátorů má tzv. kritickou hodnotu koncentrace, po jejímž dosažení mají reologické vlastnosti vzorků tendenci se měnit s rostoucí koncentrací. Získané výsledky korelovaly s výstupy zeta potenciálu.
69

Povrchové úpravy hliníkových slitin / Surface treatment of aluminum alloys

Petr, Jiří January 2013 (has links)
The thesis is focused on the surface treatment used for the preparation of aluminium alloys for the adhesive bonding. The theoretical part can be divided into three chapters. The first of them deals with aluminium alloys, the second one speaks about the adhesive bonding. The surface treatment itself, especially the conversion coating issues, is discussed in the last chapter. The experimental part is focused on the optimalization of a two-step titanium and zirconium based conversion coating technology. In the first part, the aluminium alloy is analysed by the glow discharge optical emission spectroscopy. The second part of the experiment deals with the first step of the technology, acidic deoxidation. The objective was to examine the influence of the exposure time on the morphology of the alloy surface and the shear strength of adhesive joints. In the last part of the experiment, the conversion coatings are prepared and characterised by the scanning electron microscopy and energy dispersive spectroscopy.
70

Deformačně-napěťová analýza povrchové náhrady kyčelního kloubu / Strain-stress analysis of the surface replacement of the hip joint

Vosynek, Petr January 2008 (has links)
Today is the surface hip repacement very often surgery becouse of new studies and improvements. For young and active people it's the best way to delay implantation of a total hip replacement. The objective of this study was to perform finite-element analyses of computational model of the partial/total surface replacement, conventional partial/total replacement and physiological hip joint. We obtained strain-stress states from these analyses. All results were compared one another and then were confronted with results of the physiological hip joint. The three-dimensional computational model consists of these components: sacral, pelvic and femoral bone, muscles, artificial socket, and surface hip replacement. We were using FEM system ANSYS. The geometrical models of bones were generated by means of computed tomography (CT) images. The FE model of bone reflects two types of the bone tissues (trabecular and cortical bone) and muscles which are important when standing on one leg. The model of the muscle corresponds to isometric contraction. The implants material and bone tissues were modelled as isotropic linear elastic material. The model was loaded by force, corresponding to load by standing on one leg.

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