• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 16
  • 10
  • Tagged with
  • 26
  • 25
  • 7
  • 7
  • 6
  • 5
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 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.
21

Funkční organicko-anorganické nanostruktury / Functional organic-inorganic nanostructures

Kelíšek, Petr January 2019 (has links)
Diploma thesis deals with preparation of multilayered organic-inorganic nanostructures via PECVD technology and analysis of optical properties of these layers by spectroscopic ellipsometry. The theoretical part handles the definition of thin layers, layered and gradient nanostructures, plasma enhanced chemical vapor deposition and principles of spectroscopic ellipsometry. In the experimental part, used materials and chemicals are described, afterwards follow a complete description of the apparatus used for sample preparation and a description of the sample preparation procedure. The results part consists of methodology of preparing material models necessary for ellipsometric measurements and evaluation of optical properties of deposited nanolayers.
22

Studium vlastností virových kapsidových proteinů a vývoj rekombinantních vakcín a diagnostických komponent založených na umělých virových strukturách / Studies of properties of viral capsid proteins and development of recombinant vaccines and diagnostic components based on artificial viral structures

Fraiberk, Martin January 2017 (has links)
The aim of this study was to develop a system for easy production of different veterinary chimeric vaccines based on stable mouse polyomavirus (MPyV) structures. The system is designed for antigens that are problematic in production or stability. First, universal vectors for baculovirus-directed production of chimeric MPyV VLPs or pentamers based on the major capsid protein VP1 were designed to be exploited as vaccines against other pathogens. The different strategies used in this study are based on: A) exposure of selected immunogenic epitopes on the surface of MPyV VLPs by inserting them into a surface loop of the VP1 protein, B) insertion of foreign protein molecules inside the VLPs, or C) fusion of a foreign protein or its part with the C-terminus of VP1 protein, thus forming giant pentamers of a chimeric protein. Candidate vaccine antigens against porcine circovirus 2 (PCV2), the causative agent of porcine circovirus 2 systemic diseases (PCV2-SD) which causes significant economic losses in swine breeding, were prepared using the constructed vectors. All candidate vaccines induced the production of antibodies against the capsid protein of PCV2 after immunization of mice. The candidate vaccine Var C based on fusion of MPyV and PCV2 capsid proteins, is able to induce production of antibodies with...
23

Studium fotovoltaických nanostruktur mikroskopickými metodami / Study of photovoltaic nanostructures using microscopy methods

Hertl, Vít January 2018 (has links)
V této diplomové práci je nejprve ve zkratce uvedena teorie fyziky solárních článků, kde jsou zmíněny klíčové procesy ovlivňující účinnost konverze slunečního záření na elektrickou energii. Dále je předložena rešerše o fotovoltaických nanostrukturách (nanodráty, nanokrystaly), jejichž implementací je možné účinnost solárních článků zvýšit. V přehledu experimentálních technik ke zkoumání fotovoltaických nanostruktur je důraz kladen zejména na korelativní měření pomocí SEM a AFM, vodivostního AFM, měření EBIC a mikroskopické měření elektroluminiscence. V experimentální části jsou předloženy výsledky měření struktur mikrokrystalického křemíku, vzorku hetero-přechodového Si solárního článku s kontakty na zadní straně (IBC-SHJ z projektu NextBase) a V-pitů vzorku InGaN/GaN kvantových jam. Měření elektroluminiscence bylo provedeno na vzorcích III-V polovodičů (InGaP, GaAs). Byly vypočítány jinak těžko dostupné charakteristiky III-V tandemových solárních článků pomocí elektroluminiscence a srovnání vlastností IBC-SHJ zjištěných pomocí mikroskopického měření elektroluminiscence a EBIC. Provedením experimentů bylo zjištěno, jakým způsobem se dělí proud vybuzený svazkem elektronů mezi hrot AFM a vzorek mikrokrystalického křemíku.
24

Studium transportu náboje v polovodičových nanostrukturách pomocí časově rozlišené multi-terahertzové spektroskopie / Charge transport in semiconductor nanostructures investigated by time-resolved multi-terahertz spectroscopy

Kuchařík, Jiří January 2019 (has links)
Terahertz conductivity spectra contain information on charge transport mechanisms and charge confinement on nanometer distances. In this thesis, we make a substantial progress in understanding of terahertz conductivity in several regimes. First, we theoretically investigate linear terahertz conductivity of confined electron gas: while the spectra of degenerate electron gas exhibit geometrical resonances, the response in non-degenerate case smears into a single broad resonance due to the wide distribution of charge velocities. Then, we theoretically and experimentally analyze various TiO2 nanotube layers: their linear charge transport properties strongly depend on the fabrication process, which influences the internal structure of the nanotube walls. In the main part of the thesis, we develop a framework for evaluation of the nonlinear terahertz response of semiconductor nanostructures based on microscopic Monte-Carlo calculations. The nonlinear regime is highly non-perturbative even in moderate fields as illustrated by efficient high harmonics generation. We investigate measurable nonlinear signals for various semiconductor nanostructures; metallic nanoslits filled with nanoelements are the most promising for the experimental observation of terahertz nonlinearities. These nonlinearities per unit charge are...
25

Analýza nanostruktur metodou ToF-LEIS / Analysis of Nanostructures by ToF-LEIS

Duda, Radek January 2015 (has links)
The presented thesis deals with the utilization of TOF-LEIS analytical method in the area of nanostructure analysis. A new procedure for depth profiling of the elemental composition of the sample, based on the alternate measurement with the DSIMS method, was established. The TOF-LEIS method is able to detect the interface between the layers before its mixing by the ion beam of the DSIMS method. Furthermore, a procedure of TOF-LEIS spektra modification was established to obtain the actual concentration of elements in the sample by reduction of a multiple collision contribution. By comparison of TOF-LEIS spectra with the results received by the DSIMS method the ratio of molybdenum and silicon ion yields was obtained. In the next section advantages of the TOF-LEIS method in combination with XPS during analysis of thermal stability of gold nanoparticles are presented. The mutual complementarity of both methods is shown and final conclusions are supported by electron microscopy images. The final section deals with a newly assembled apparatus for the TOF-SARS analytical method and shows its possibilities regarding the detection of hydrogen on the graphene.
26

Elektrochemická charakterizace nanostrukturovaných povrchů modifikovaných biolátkami s thiolovou vazbou / Electrochemical Characterization of Nanostructured Surfaces Modified by Substancies with Thiol Bound

Urbánková, Kateřina January 2014 (has links)
This master thesis deals with nanotechnology, nanoparticles and nanostructured surfaces, electrochemical methods, especially voltammetry, cyclic voltammetry, electrochemical impedance spectroscopy and contact angle measurement. One part is focused on electrodes primarily nanostructured and modified by substancies with thiol bound. Tutorial for preparation of gold nanostructured electrods is introduced in practical section including SEM photos of electrode surface. Nanostructured and bare gold electrodes were modified by 11-mercaptoundecanoic acid, streptavidin, glycine and biotin and measured by cyclic voltammetry, electrochemical impedance spectroscopy and contact angle.

Page generated in 0.0693 seconds