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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.
21

Vliv přídavku ethenu na aktivitu Z-N katalyzátoru pro nízkotlakou polymeraci propenu / Influence of Ethene Addition on Ziegler-Natta Catalyst Performance in Low-pressure Propene Polymerization

Hoza, Adam January 2010 (has links)
The aim of the study will be the determination of the kinetic profiles of the polymerization of propene, ethene and their mixtures with commercial Ziegler-Natta catalyst by application of two different experimental procedures. The prepared polymer material will be utilized for the SEC analysis and subsequent evaluation of the concentration of active sites. The determined molecular mass distribution curves will be further investigated by the application of the procedure, which deconvolute the overall profile on the basic Flory's distribution functions. Then the comprehensive study about character and behavior of various types of active centers in dependence on time and type of monomer will result from this investigation.
22

Možnosti zlepšení agregace a separace suspenze při úpravě pitné vody / Methods of improvement of particle formation and separation processes in drinking water treatment

Kubalík, David January 2013 (has links)
This work is focused on improvement of particle formation and separation processes in drinking water. These include the comparison of the dynamics of different coagulation reagents (aluminum sulphate and ferric sulphate) to find the optimal dose of coagulant. During centrifugation test is important to find such a setting centrifuge where we get the best results. In this work we studied the influence of the total mineralization at the optimum dose of coagulant.
23

Vztah parametrů přípravy belitického cementu a jeho hydraulických vlastností / Relation between Preparation Parameters of Belite Cement and its Hydraulic Properties

Staněk, Theodor January 2009 (has links)
The dissertation thesis is devoted to the study of belite clinkers and to the possibilities of the increase in their hydraulic activity. The mechanism and the kinetics of belite clinker formation were studied together with the relation of the velocity of these processes and the hydraulic activity of clinker. The influence of various parameters (degree of lime saturation, duration and temperature of burning) of the belite clinker preparation on the belite clinker development in time, on belite polymorphism, on the chemical composition of belite crystals and on the belite cement hydraulic activity was studied, too. The research methods used for the investigation involved electron microscopy, optical microscopy, X-ray diffraction analysis, high-temperature microphotometry and calorimetry. The resulting clinkers were hydraulically activated by addition of calcium sulfate. The experiments have proven that the higher rate of belite formation does not lead to the increase of its hydraulic activity, as opposed to that of alite. On the other hand, the chemical activation by sulfate anions enables to prepare clinker with relatively higher degree of lime saturation with minor admixture of alite and anhydrite, which is hydraulically activated. The work was concluded by experimental burning of belite clinker doped with sulfate anions in a model rotary kiln and by the preparation of cements blended with common industrial alite clinker. The results indicate the possibility of separate industrial production of special belite clinker alongside with common alite clinker and the production of economically and environmentally beneficial blended Portland cements with suitable technological parameters, or targeted production of special cements with properties corresponding to their required utilization.
24

Kinetika krystalizace v semikrystalických nanokompozitech / The Crystallization Kinetics in Semicrystalline Nanocomposites

Fiore, Kateřina January 2010 (has links)
Růst krystalů zásadně ovlivňuje morfologii a tím také mechanické vlastnosti semikrystalických polymerů. Tato PhD práce přináší alternativní pohled na popis kinetiky krystalizace v polyolefinech plněných slabě interagujícími částicemi. V nanokompozitních materiálech vysoký specifický povrch plniva i při nízkých plněních zásadně ovlivňuje dynamiku řetězců. V blízkosti povrchu plniva začíná hrát významnou roli zpomalená reptace způsobená jak vzájemnými interakcemi plnivo-polymer tak prostorovým omezením mezi nanočásticemi. Růst krystalů byl zkoumán pomocí polarizovaného optického mikroskopu vybaveného horkým stolkem. Výsledky byly korelovány s teoretickými modely a rozsáhlými počítačovými simulacemi na molekulární úrovni. Pozorovaný pokles rychlosti růstu sférolitů v závislosti na obsahu plniva a molekulové hmotnosti matrice je interpretován na základě imobilizační teorie, tedy, zpomalení reptačního pohybu.
25

Studium kinetiky samouspořádávacího procesu kolagenu I / Kinetics Studies of Collagen I Self-Assembly

Voldánová, Michaela January 2016 (has links)
Collagen, the most abundant protein of connective tissues, in various forms has a wide applications due to their diverse biological and chemical properties. One of the forms are collagen hydrogels, which are considered very suitable material for applications in tissue engineering, because they are able to provide biodegradable scaffolds that its properties correspond with living tissues. These systems are used for example as scaffold for targeted drug delivery with controlled release, in combination with cells can be used for the regeneration and reconstruction of tissues and organs. Heating the aqueous solution of collagen leads to spontaneous self-assembly process to variously distributed fibrillar structures, which are at a later stage of fibrillogenesis prerequisite for creating a three-dimensional supporting network, which is the basic building block of the gel. The resulting properties of the hydrogel depend not only on its structure, but also on the conditions which cause self-assembly process. Hydrogels were performed at 37 ° C and physiological pH. Studied structural variable was the concentration of collagen. So far, for the research of self-assembly were used spectrometric methods, which only provide information about kinetics of morphogenesis. In this work to study the kinetics of collagen I self-assembly were used rheological methods, which additionally give information about viscoelastic properties of the resulting material. The obtained experimental data confirmed two-step process of collagen I fibrillogenesis consisting of nucleation and growth process. Rheological hydrogels collagen behaved as a nonlinear yield-pseudoplastic. An attempt was made to molecular interpretation of the results. Using two-parametric Avrami equation was determined the rate of self-assembly for each concentration of collagen and the value of Avrami exponent determining the shape of produced units. The prepared hydrogels were subjected to increasing shear stresses (strain amplitude, shear rate). Larger amplitudes leads to collapse of the hydrogel structure, which is able to again partially regenerated.
26

Fyzikální simulace na GPU / Physics Simulation on GPU

Janošík, Ondřej January 2016 (has links)
This thesis addresses the issue of rigid body simulation and possibilities of paralellization using GPU. It describes the basics necessary for implementation of basic physics engine for blocks and technologies which can be used for acceleration. In my thesis, I describe approach which allowed me to gradually accellerate physics simulation using OpenCL. Each significant change is described in its own section and includes measurement results with short summary.
27

Vliv rozdílného způsobu silového tréninku na tělesné složení, posturální stabilitu a svalovou a explozivní sílu u skupin závodníků v Men's physique a vrcholových Street Workout atletů / Influence of different way of strength training on body composition, postural stability and muscle and explosive strength in Men's Physique and Street Workout Athletes

Regál, Ondřej January 2018 (has links)
Title: Influence of different way of strength training on body composition, postural stability and muscle and explosive strength in Men's Physique and Street Workout Athletes Objectives: The aim of the thesis was to find out the level and the difference between the parameters of body constitution, postural stability and muscular and explosive force of upper and lower limbs with groups of Men's Physique and Street Workout athletes. Methods: The research sample was represented by two groups (Men's Physique competitors and Street Workout athletes). We assessed chosen parameters of body constitution by Tanita MC-980MA, postural stability by RS Footscan, explosive force (Kistler) and muscular force (Cybex Humac Norm and Takei A5401). Assessed parameters of body constitution were percentage of body fat and fatless matter. In the tests of postural stability, we assessed total travel way of the center of pressure (TTW) in chosen stands (open/closed eyes and one- leg left/right). When testing explosive force, overall produced maximal force and height of the leap were assessed. Muscular force of upper limbs was evaluated by produced force in kg and muscular force of lower limbs was assessed with the help of muscular force moment in concentric muscle activity with angular velocity 60ř·s-1. Result: We found...
28

Nové metody hmotnostní spektrometrie pro stopovou analýzu látek v lidském dechu. / New mass spectrometric methods for trace gas analysis of human breath.

Brůhová Michalčíková, Regina January 2019 (has links)
This dissertation thesis summarizes results of experiments that have been carried out during my PhD studies related to the new mass spectrometric methods for trace gas analysis of human breath. The thesis is divided into the theoretical and experimental part. The chapter at the beginning of this dissertation summarizes the current research in the area of breath analysis. It is describing the common breath metabolites, benefits and challenges of the method for therapeutic monitoring and clinical diagnosis and current applications. The next chapter of the theoretical introduction describes the techniques suitable for this area of research, with a special emphasis on mass-spectrometric techniques (in particular the selected ion flow tube mass spectrometry, SIFT-MS, method that allows accurate quantification of trace gases and vapours in humid air/human breath). All these parts are elaborated via the scientific literature review. The following chapters are then directly related to my own research and describes the conducted experiment, including the results obtained. This experimental part "Results and Discussion" is divided to the individual subsections, which are conceived as the commentaries to the enclosed research papers published in peer reviewed journals. The first is the detailed step by step...
29

Studium mechanismu účinku metallakarboranových inhibitorů HIV proteasy / Analysis of the mechanism of action of metallacarborane inhibitors of HIV PR

Svoboda, Michal January 2011 (has links)
English Abstract Shortly after the identification of HIV as a causative agent of AIDS, an aspartic protease was identified in the viral genetic information. The very same time protease has become one of the dominant therapeutical targets in AIDS therapy. The introduction of protease inhibitors into the antiretroviral therapy has led to a significant improvement in the quality and length of life of HIV patients. However, the virus is still able to effectively prevent the impact of an inhibitor via generating inhibitor-resistant mutated protease variants. Thus, there is a constant need for novel types of inhibitors that would be capable of effectively blocking these resistant variants and simultaneously not supporting the development of novel resistant viral strains. One way to identify such inhibitors could be searching for compounds interacting with the enzyme at different sites than the active cavity, via the mechanisms of noncompetitive or uncompetitive inhibition. The group of compounds called metallacarboranes - inorganic compounds consisting of carbon, boron, hydrogen and metall ion - were shown to exhibit such an activity against HIV-1 protease. However, for further optimization of these inhibitors, detailed biophysical investigation of the enzyme-inhibitor complex is needed. This work focuses on the...
30

Příprava a následující in vitro saturační studie radiofarmaka 99mTc-DTPA-ramucirumab na PC-3 buňkách / The preparation and the following in vitro saturation study of the radiopharmaceutical 99mTc-DTPA-ramucirumab on PC-3 cell line

Sabolová, Klaudia January 2020 (has links)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Student: Klaudia Sabolová Supervisor: Mgr. Pavel Bárta, Ph.D. Title of diploma thesis: The preparation and the following in vitro saturation study of the radiopharmaceutical 99m Tc-DTPA-ramucirumab on PC-3 cell line In cancer treatment, immunology is given prominence, which compared with chemotherapy and radiotherapy has a lower risk of side effects on healthy tissues. Immunotherapy includes application of monoclonal antibodies aimed at some tumour antigens using either non conjugated monoclonal antibodies or conjugated ones with an appropriate effector element, such as radionuclide. Angiogenesis plays the important role in pathogenesis of tumour diseases. Angiogenic process is regulated mostly by the interactions among vascular growth factors (VEGFs) and VEGF receptors (VEGFR). The main regulator of angiogenesis is VEGF-A. The blocking of the interaction among VEGF-A and its receptors VEGFR-1 and VEGFR-2 inhibits angiogenesis, and so does the growth of tumours. Ramucirumab is the monoclonal antibody with antiangiogenic effect, which blocks this interaction by its binding to the extracellular VEGFR-2 domain with high affinity. The presented study is focused on ramucirumab...

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