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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.
11

DFT výpočty grafenu s výhledem na uplatnění v biosenzorech / DFT calculations of graphene regarding to biosenzoric applications

Špaček, Ondřej January 2021 (has links)
This diploma thesis is focused on calculation of both structure and electronic properties of the graphene after the adsorption of atomic and molecular oxygen and urea using the Density Functional Theory (DFT). The influence of van der Waals interactions on the structure and adsorption energy is studied, as well as influence of the thermal corrections, the charge density spatial distribution and the electronic doping of graphene after the adsorption of the adsorbant on the graphene.
12

Zušlechťování bioplynu metodou PSA / Upgrading biogas by PSA

Krhut, Štěpán January 2017 (has links)
This work deals with bio gas cleaning by a PSA method and modernizing of a laboratory unit. Raw bio gas contains many unwanted elements like carbon dioxide mostly which lowers its energy potential then. To extend the possibilities of usage of bio gas it is necessary to remove such elements. One of the well-known method for eliminating CO2 out of the bio gas is the method called Pressure Swing Adsorption (PSA). This work describes PSA method and compares it with other methods for cleaning the bio gas. In the following part of my work I am introducing the original laboratory PSA unit which is placed in the laboratory of UPI institution for research purposes. The modernization of the method was made by changing the manual valves for electromagnetic ones and there was also designed a new control system unit for two control modes. For manual and for automatic. The essential function is based on remote controlling the valves either by switches or by a program. The electric control panel was created for such required modes. The automated process was controlled by Arduino programming platform which was integrated into the panel. In the case of the next measurement and reading there was created a detailed description for user on how to operate the control panel and also the comments for control program of automatization.
13

Sledování účinnosti vybraných adsorbentů na odstraňování mikropolutantů z pitné vody / Monitoring the effectiveness of selected adsorbents to remove micropollutants from drinking water

Kabelíková, Eva January 2019 (has links)
This diploma thesis deals with the effectiveness of selected adsorbents for the removal of micropollutants from drinking water. In the first part there are described individual types of micropollutants and their occurrence in water. Further, there are described pharmaceuticals and their consumption in the world. At the end of the first part, the possibilities of removing micropollutants in drinking water treatment are approached and two water treatment plants in the Czech Republic have been selected, which already use the technology of the removal of some micropollutants. In the practical part of this diploma thesis is performed an experiment of removal of Ibuprofen from model water by adsorption on selected materials, which are Filtrasorb F100, Bayoxide E33 and GEH.
14

Studium nových katalytických materiálů pro palivové články s polymerní membránou / Study of new catalytic materials for proton exchange membrane fuel cells

Homola, Petr January 2012 (has links)
Title: Study of new catalytic materials for proton exchange membrane fuel cells Author: Petr Homola Department: Department of Surface and Plasma Science Supervisor: Prof. RNDr. Vladimír Matolín, DrSc. Abstract: Submitted thesis deals with study of thin layers based on platinum and cerium oxides in order to use them in fuel cells with polymer membrane (PEM- FC). A set of samples with different amount of platinum was prepared by means of magnetron sputtering. Samples were investigated by X - ray Photoelectron Spectroscopy (XPS) and results were confronted with sputtering parameters. It was found out that chemical state of platinum is related to its amount in thin layer. The less platinum was contained in thin layer, the less amount of Pt0 state was observed and amounts of Pt2+ and Pt4+ states increased. Furthermore the temperature stability of prepared layers in the interval from room temperature to 250 ◦ C was studied by means of XPS. The adsorption of carbon monoxide was measured by infrared absorption spectroscopy (IRAS). Increasing degree of adsorption on sample probably related to platinum reduction with increased tem- perature was observed. Measurements of other samples were devaluated by strong contamination with nickel carbonyls. Keywords: PEMFC, cerium oxide, magnetron sputtering, XPS, CO adsorption
15

Analýza aDNA ze zubů a kosterního materiálu s využitím miniSTR lokusů. / Ancient-DNA analysis of teeth and skeletal remains with utilization of miniSTR loci.

Kvítková, Dana January 2010 (has links)
During the last twenty years, immense progress occurred in the area of analysis of DNA extracted from historical material. Considering the common level of preservation of tissue material, this analysis is usually executed on samples procured from bones and teeth. The analysis of soft mummified tissue is possible only in rare cases. Limiting factor of these analyses is a high degree of degradation and small amount of DNA extractable from this kind of material. First researches concentrated only on short sections of mainly mitochondrial DNA. Today, the analysis of the complete mitochondrial genome of both contemporary and extinct organisms was made possible. In case of analyses conducted on human remains, sections of nuclear DNA are far more valuable, because they can reveal information including not only subject's sex, but also possible kinship between subjects found e.g. in the same grave. Fundamental component of the whole analysis is the process of extracting DNA from cells. Probably every laboratory working with historical DNA uses a differently modified extract protocol. The main requirement for methods of extraction is to secure enough DNA with such a level of purity that would allow its use for following steps of the analysis. Taking in consideration high fragmentation of DNA, it is necessary...
16

Teoretické studium vlastností 3D a 2D zeolitů / Theoretical Investigation of Properties of 3D and 2D Zeolites

Ho, Viet Thang January 2016 (has links)
Zeolites have been widely used in many different fields including catalysis, adsorption and separation, ion exchange, or gas storage. Conventional zeolites have three- dimensional (3D) structures with microporous channel system; typical pore sizes are well below 1 nanometer, therefore, diffusion limitation plays important role in many process and bulkier reactants (or products) cannot enter (or leave) the zeolite channel system. Two-dimensional (2D) zeolites prepared in last years can lift all diffusion limitation and they thus offer a very attractive alternative to conventional 3D zeolites. 2D zeolites attracted considerable attention on the experimental side; however, understanding of 2D zeolites based on computational investigation or on a combination of experimental and computational investigation is limited. A motivation for the computational work presented here is to improve our understanding of properties of 2D zeolites based on computational investigation. The originality of the research presented herein is in the strategy: we carried out systematic investigation of properties of corresponding 2D and 3D zeolites and we focus on the identification of similarities and differences. The most important zeolite properties, i.e., presence of Brønsted and Lewis acid sites, are investigated. A number of...
17

Příprava tenkých vrstev plazmovou polymerací jako stabilních podložek pro biolékařské aplikace / Thin films of plasma polymers as stable supports for biomedical applications

Gordeev, Ivan January 2012 (has links)
Title: Thin films of plasma polymers as stable supports for biomedical applications Author: Ivan Gordeev Institute: Charles University in Prague, Department of Macromolecular Physics Supervisor of the doctoral thesis: Doc. Ing. Andrey Shukurov, Ph.D, Charles University in Prague, Department of Macromolecular Physics. Abstract: Plasma polymers have been widely considered for use as bio-active coatings. In biomedicine, the surfaces that withstand accumulation of biofilms are of particular importance. This thesis is focused on development of new plasma-based methods for deposition of bio-resistant (non-fouling) plasma polymers. Poly(ethylene oxide) was the subject material. R.f. magnetron sputtering, plasma-assisted thermal vapour deposition and amplitude modulated atmospheric pressure surface dielectric barrier discharge were the methods adapted to fabricate thin films with tunable chemical composition, cross-link density and biological response. A new insight was gained into the processes of plasma polymerization as well as into composition/structure relationship and its effect on biological properties of resultant films. Keywords: plasma polymerization, PEO, 'non-fouling' properties, protein adsorption, cell adhesion
18

Biodegradace lehčených polyuretanů v půdě a následná analýza produktů rozkladu / Biodegradation of lightweight polyurethanes in soil and subsequent analysis of their degradation products

Pražanová, Kateřina January 2018 (has links)
According to the Waste Framework Directie 2008/98/ES and the Czech law on waste 185/2001 Sb., waste preienton is the main priority in waste management. Using biodegradable plastcs seems to represent a suitable approach in fulflling the strategy. The subject of this diploma thesis is biodegradable lightweight polyurethanes (PURs), which might represent suitable materials for repellent fences in agricultural landscapes. Biodegradaton processes are assumed to begin in the agricultural soil afer their lifetme. The biodegradability of new lightweight PURs (BIO 8-10), presented as material mineralizaton, was tested in agricultural soil under laboratory conditons according to the ASTM Internatonal standard method D5988-03. Afer the nine-month experiment the material with the highest biodegradability (BIO 10) containing starch (28 wt. %) was mineralized to 42.0 ± 4.2 %. Cellulose (the positie control) was completely mineralized; thus, the ialidity criterion (positie control mineralizaton > 70 %) was accomplished. Afer the biodegradability test, degradaton products (residual PURs) were separated from the soil by a two-step method using fuidisaton and fotaton, according to a modifed procedure described in Nuelle et al. (2014). The procedure enabled a subsequent analysis of PUR residues with Fourier transform...
19

Imobilizace proteinových makromolekul na polymerní nosiče / Protein macromolecules immobilization onto polymer carriers

Šitnerová, Michaela January 2017 (has links)
Charles University, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical Technology Consultant: PharmDr. Ondřej Holas, Ph.D. Student: Michaela Šitnerová Title of Thesis: Protein macromolecules immobilization onto polymer carriers Enzymes are unique biocatalysts because of their properties. They are highly specific, selective and functional even under mild reaction conditions. The method of immobilization is used to increase their operational stability, activity and possible reuse. This process allows the wide use of enzymes in industry, for example in the food industry, analytical chemistry, chemical synthesis and in the pharmaceutical industry. The aim of my thesis was immobilized enzyme acetylcholinesterase (AChE) on the surface pellets of microcrystalline cellulose (MCC). Used method was simple sorption, immobilization using glutaraldehyde, and TEMPO oxidation using MCC. Well known Ellman's method served to measure the activity of AChE. The absorbance of the solution with the immobilized AChE was measured spectrophotometrically at 412 nm.
20

Interakce ibuprofenu s huminovými látkami a stabilita vzniklých komplexů / Interaction of Ibuprofen with Humic Substances and Stability of Formed Complexes

Vlašicová, Silvie January 2021 (has links)
Nowadays, huge amounts of drugs get into watercourses and soil due to wrong disposal in sewage treatment plants. In this work, the sorption and desorption behavior of Ibuprofen in the soil system was studied, especially in relation to humic acids. The degree of sorption and desorption was defined from the change in ibuprofen concentration analyzed by UV-VIS spectrometry, changes in conductivity and pH were also observed. Ibuprofen shows good sorption properties, desorption was really minimal. It can be assumed that there is a strong bond between ibuprofen and both soil and lignite humic acids and therefore there is no risk of leaching back into solutions. Therefore, if ibuprofen entered the environment, it would be sorbed into the humic acids contained in lignite or soil, which means that it should not be harmful in any way.

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