• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 70
  • 15
  • 1
  • Tagged with
  • 86
  • 57
  • 26
  • 26
  • 21
  • 17
  • 16
  • 13
  • 11
  • 11
  • 11
  • 10
  • 9
  • 9
  • 9
  • 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

Formulace a testování nanočástic z větvených polyesterů s siRNA / Formulation and testing of siRNA-loaded branched polyesters nanoparticles

Medviďová, Simona January 2018 (has links)
Charles University Faculty of Pharmacy in Hradcec Králové Department of Pharmaceutical Technology Supervisor: doc. RNDr. Milan Dittrich, CSc. Student: Simona Medviďová Title of thesis: Formulation and testing of branched polyesters siRNA-loaded nanoparticles The progression of development increases demand for new and more effective drug systems formulations. This diploma thesis is focused on the preparation of nanoparticles from biodegradable branched polyesters based on PLGA, which are suitable for the transport of an oligonucleotide of a small interfering nucleic acid, siRNA. The theoretical part focuses on the characteristics of usable polymers, their possible modifications, the methods of preparation with closer look at the selected nanoprecipitation method, the important parameters such as particles size, zeta potential, and polydispersity. The main part is also characterization of siRNA in terms of structure, properties, modifications, and its function. A more extensive experimental part deals with the appropriate choice of type and concentration of polyester and stabilizer, methods of preparation and characterization of nanoparticles, and the possibility of analyzing encapsulated siRNA. Chapters results and discussion compares polyesters branched on tripentaerythritol, and polyacrylic acid...
22

Statistické vlastnosti lokálních stereologických odhadů / Statistical properties of local stereological estimators

Hájek, Tadeáš January 2017 (has links)
In this thesis statistical properties of local stereological estimators of par- ticle volume are investigated. The emphasis is on the estimation of the va- riance of the local estimator and its components - the variance due to the variability in the particle size distribution and the variance due to the lo- cal stereological procedures. Various ways of estimation for independent and correlated particles are presented. Results of simulation studies for both inde- pendent and correlated ellipsoidal-shaped particles are presented. Described estimators are demonstrated on real biological data. Comprehensive theory that leads to the local stereological estimators of volume is presented too. 1
23

Vliv provozních parametrů kotle na přítomnost jemných částic ve spalinách / Effect of operating parameters of the boiler on presence of fine particles in flue gas

Košťál, Jan January 2017 (has links)
This diploma thesis is devoted to the issues of the formation of fine particles in dependents on the combustion parameters. The first part of thesis is review, which summarized the information about combustion process and about formation of the gaseous products and fine particles inside them which created during combustion process. The main content of thesis is realization of measurements of fine particles from combustion, in several types of the tested combustion devices. Next part is a description of used measurement devices, which used for measurement. Last chapters are focused on evaluation of results from the measurements, comparison of the measurements between themselves and the finding the existence of the dependence of the formation of fine particles on operational parameters of boiler. And all results are evaluated in the conclusion.
24

Vliv prachových částic na kluzný kontakt / Influence of dust particles on sliding contact

Píšala, Jan January 2019 (has links)
Master's thesis "effect of dust particles on sliding electrical contact" summarizes the sliding contact theory and praxe in rotating electrical machines. The principle of brush machines is described and the working environments are defined. The individual components of the sliding contact and reasons of their degradation are described in detail. Emphasis is placed on the influence of foreign particles, which can be assessed in practice by the method of dust particles. Furthermore, these theoretical knowledge was used in the practical assessment of the technical condition of various machines, as well as the called method. One set of brushes for the traction motor of the locomotive T47.0 was also experimentally innovated.
25

Návrh metodiky měření pro hodnocení účinnosti filtrace přenosných čističek vzduchu / Design of the methodology of measurement for evaluation of filtration efficiency of portable air cleaners and purifiers

Dvořáková, Michaela January 2021 (has links)
This work focuses on the research and comparison of several types of air purifiers. It clarifies the principles of filtration and describes the basic types of air purifiers. Part of this work is designed methodology of measurement for comparison of filtration efficiency and filtration rate. The experimental part of this work contains the measurement and comparison made for two types of air purifiers. Selected purifiers were De’Longhi AC230 with mechanical filters and ionic air purifier Ionic-CARE Triton X6. Within the framework of this work an experimental set-up was constructed in the home environment for the simulation of real conditions for the function of the air purifiers. The measurement results provide information about aerosol number concentration process during the measurements and evaluation of filtration efficiency of air purifiers.
26

Filtr s akustickou povrchovou vlnou / Surface acoustic wave filter

Tichý, Jakub January 2010 (has links)
The theoretical part of this thesis deals with principles and characteristics of the surface acoustic wave filter. It explained the principle of magnetostriction and piezoelectric effect, which uses a filter. In the practical part in the program Comsol Multiphysics are made three simple models of SAW filter. Some modes are founded and are compared to previously known results. In the next phase of project is further studied using the parametric analysis. In the last phase of project is applied global optimization PSO at admittance characteristic from simple 2D structure. The results are compared with the commercially produced devices.
27

Příspěvek k praktickému posouzení expresní metody pro hodnocení kvality kluzného kontaktu / Contribution to express practical assessment methods for evaluating the quality of the sliding contact

Kurzępa, Marek January 2015 (has links)
This thesis is devoted to the topic of kluzný kontakt and its diagnostic, especially to the type of diagnostic using the method of -- of dust particles. The author presents an example of applying this method and deals with the topic of development of a laboratory template that will give access to bigger variability in studying this method.
28

Porovnání vodní dýmky, elektronických cigaret a klasických cigaret z hlediska emitovaných částic / Comparison of hookah, electronic cigarette and classic cigarettes in regard to emitted particles

Krátký, Štěpán January 2015 (has links)
This master’s thesis is focusing on the research of chosen smoking types and their comparison in regard to emitted particles. Aerosol created during smoking represents a serious threat for human health. For purposes of this work an experimental set-up was constructed in the Laboratory of Aerosol Research at BUT FME and experiments simulating smoking process were carried out. The results of these experiments are presenting objective information about the constitution of produced aerosol which enters smoker’s lungs. There are many myths about the harmful effects of different types of smoking. The goal of this work is to verify and resolve these myths and set the foundation for possible upcoming research in this area.
29

Paralelizace evolučních algoritmů pomocí GPU / GPU Parallelization of Evolutionary Algorithms

Valkovič, Patrik January 2021 (has links)
Graphical Processing Units stand for the success of Artificial Neural Networks over the past decade and their broader application in the industry. Another promising field of Artificial Intelligence is Evolutionary Algorithms. Their parallelization ability is well known and has been successfully applied in practice. However, these attempts focused on multi-core and multi-machine parallelization rather than on the GPU. This work explores the possibilities of Evolutionary Algorithms parallelization on GPU. I propose implementation in PyTorch library, allowing to execute EA on both CPU and GPU. The proposed implementation provides the most common evolutionary operators for Genetic Algorithms, Real-Coded Evolutionary Algorithms, and Particle Swarm Op- timization Algorithms. Finally, I show the performance is an order of magnitude faster on GPU for medium and big-sized problems and populations. 1
30

Dodatečný ohřev plazmatu výkonovým svazkem atomů deuteria na tokamaku COMPASS / Additional plasma heating of tokamak plasma by powerful beam of deuterium atoms on the COMPASS tokamak

Bogár, Klára January 2021 (has links)
Two neutral beam injectors (NBIs) were installed on the COMPASS tokamak as a main upgrade after its move from the UK to Prague. The thesis deals with general experimental specifications of additionally heated plasmas by the NBI under the wide range of conditions on the COMPASS tokamak. The geometrical parameters of the beams are determined from the spectro- scopic measurements. Consequently, the NBI power passing through the narrow duct connecting NBI and tokamak chamber is investigated. The passing fraction of the NBI power is confirmed by the power balance analysis, which provides information about the delivered power into the plasma based on the plasma parameters. Once the delivered power is well known a description of beams interaction with plasma via global parameters such as the plasma temperatures, the plasma density, the energy confinement time and neutron yield is given. It is shown, that the NBIs heat mostly ions, which can reach ∼ 1 keV in the plasma core. Moreover, the impact of the fast ions presence on the commonly observed MHD activities, the sawtooth instability and the edge localized modes (ELMs), is discussed and compared with results from other tokamaks. The sawtooth period is prolonged by the influence of the NBI from 2 ms up to 4.5 ms. The knowledge of the NBI passing power into...

Page generated in 0.0369 seconds