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Determination of distribution coefficients of perfuorinted compounds in 1-octanole/water system
Skrottová, Anežka ; Čabala, Radomír (advisor) ; Nesměrák, Karel (referee)
The aim of the bachelor thesis was to determinate distribution coefficients of 1H,1H,2H,2H-Perfluoro-1-octanol and 1H,1H,2H,2H-Perfluoro-1-decanol in 1-octanol/water system. Method used for measurement was the shake flask method. Measured substance is distributed between two immiscible liquids after intensive shaking. Concentration in both phases was measured after equilibration with Gas Chromatography - Mass Spectrometry. Knowledge of distribution coefficients helps to estimate toxic potential of substance. Logarithm of distribution coefficient of measured substances was about 3,5. It means, that measured substances are lipophilic. It is associated with their high bioaccumulation potential. They accumulate in organism and their excretion is very difficult. They also accumulate in abiotic environment. So they have negative effects on it and their production is reduced.
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Multimedia communication
Vondra, Zdeněk ; Horný, Stanislav (advisor) ; Skrbek, Jan (referee) ; Jurášková, Olga (referee)
Multimedia is a form of communication and sharing knowledge using synergic effect of parallel connected communication channels. Its main use is in producing communications products and services and in design of user interfaces. Main objective of this dissertation is to develop and create a model of multimedia communication for better understanding of the meaning and the purpose of using multimedia forms in communication process. The model will describe a system of elements and parameters of multimedia communication within the internal and external context. Another objective of this dissertation is to develop multimedia communication methodology that will be used for the design, development and evaluations of concepts of multimedia communication. The methodology will be created by applying the model of multimedia communication into the procedure structure. In theoretical way this dissertation is based on analysis of different definitions and approaches to the multimedia communications topic. This is followed by an analysis of communication theories, concepts of media, multimedia, delivery channels, and communication functions. The theoretical part is followed by the outcomes of the research in practice of four different fields of multimedia use. The knowledge gained is analyzed in the following parts in purpose of creating the model of multimedia communication and the methodology which is derived from the model. The methodology is further validated through case studies and the recommendations for further development are formulated. The model and the methodology of multimedia communication created in this dissertation present complex view on multimedia communication topic that is considered as a useful tool for meeting a specific communication purpose. Dissertation provides mechanics for use and study of multimedia communication and also defines the opportunities for further development of the methodology.
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Charakter proudění v náplňovém superkritickém extraktoru
Rochová, Kristina ; Sovová, Helena
This contribution provides a brief review on the effect of flow direction on SFE and reports our first experiments on axial dispersion measured in the course of extraction; this topic has not been sufficiently discussed in the literature yet. The flow pattern was examined by means of response to tracer injection and the results were expressed in the form of dimensionless variance S2 T,0. Tetracosane deposited on glass beads was extracted and presence of natural convection was observed when the flow was switched from downflow to upflow mode.
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Raman optical activity and conformational flexibility of peptides in solution
Hudecová, Jana ; Baumruk, Vladimír (advisor)
Title: Raman optical activity and conformational flexibility of peptides in solution Author: Jana Hrudíková Department: Institute of Physics of Charles University Supervisor: Doc. RNDr. Vladimír Baumruk, DrSc. Supervisor's e-mail address: baumruk@karlov.mff.cuni.cz Abstract: Molecular flexibility can significantly modify Raman and ROA spectral intensities, band positions and the ROA signs. Taking into account dynamic aspects of behavior of studied molecules in solution via conformational averaging therefore seems to be crucial for spectral interpretation. The first of studied models, histidine, plays an important role in metallo-enzymatic reactions and peptide folding, due to its imidazole ring. ROA spectra of His at different pH, His complexed with Cu2+ and dipeptides His- Gly and Gly-His were recorded on the spectrometer built at the Institute of Physics of the Charles University as a first step of the subsequent study. The second studied system, a cyclic hexapeptide c-(Phe-D-Pro-Gly-Arg-Gly-Asp), serves as a convenient model for β- hairpin and anti-parallel β-sheet. It was previously studied by means of VCD and IR. From molecular dynamics simulations 10 peptide geometries were selected for spectral modeling. The Raman and ROA spectra were calculated ab initio. For a model fragment Phe-D-Pro, which...
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Anthropological conceptualisations of sexual categories
Prokopík, Petr ; Vrhel, František (advisor) ; Uherek, Zdeněk (referee) ; Skupnik, Jaroslav (referee)
The thesis inquires into the possibilities which anthropological study has in attempting to conceptualise the rich manifestations of human sexuality. It discusses the problems of biological determination and normativity in the study of sexuality as well as its problems in cross-cultural applications. In examples of interpretation of well known phenomena such as "hijra", "two-spirit" and "ritual homosexuality" it demonstrates theoretical concepts of "third sex", "third gender", and "sexual lifeways" as possible tools of cross-cultural categorization. It presents an original field research investigating the formation of a specific new alternative sexual category within gay communities in three language contexts - Czech, English and German. Offering a situational analysis which concerns not only a description of cultural meanings and symbols known by actors, and an analyses of historical development, but also offers an interpretation of actors subjectivity displayed in individual motivations, desires and meanings created and used by actors. It endeavours to give a reflection of relations between sexual category and individual motivations during the process of accepting sexual identity and forming an alternative sexual category.
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Influence of cement moulds on the structure of nodular iron castings
Stachovec, Ivo ; Šenberger, Jaroslav (referee) ; Rusín, Karel (advisor)
The object of the diploma thesis was to solve and to describe the influence of cement sands moulds on the structure of castings with cast iron LKG. The work was intent on watching the tendency of cement sands to the metal penetration of castings, rising of the compounds on the metal mould interface and liquid metal and accompanies elements on the shape of the graphite in the surface of casting. The study of this processes has a big theoretical and a practical meaning, for prevent and prediction of rising of the defects that are attached with unsuitable choice of sand.
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Phosphate Binders in Refractory Application
Švec, Jiří ; Drábik, Milan (referee) ; Lang, Karel (referee) ; Havlica, Jaromír (advisor)
The doctoral thesis is focused on the study, research and development of refractories with phosphate bonding. Primary motivation is preparation of phosphate-based binders that can be applied for non-shaped insulating material fabricated by “in situ” foaming. The phosphate binders based on Al2O3-H3PO4 system are one of the most common in refractory technology. The amphoteric nature of the aluminium and its oxides require the setting of Al2O3-H3PO4 binders under the higher temperatures. Application of higher temperatures is necessary to obtain the minimal manipulation strength of as-prepared green bodies. The main goal of the work is preparation of ytrium phosphate-based binders via different preparation techniques. Yttrium based binders would allow phosphate refractory preparation by standard way, i.e via reaction between binder and reactive aggregate, without structural disintegration of foamed material even before getting manipulation strength or the final firing procedure. Yttrium is more basic than aluminium and therefore more reactive in Y2O3-H3PO4 system.. Yttrium oxide is highly refractory material and sintered yttrium monophosphate has excellent properties from the thermal and corrosive stability point of view. This fact should compensate higher price of this material. Experimental part of this work studies the possibilities of binders preparation in Y2O3-H3PO4 system. The mixtures were designed to prepare binding phase Y(H2PO4)3. Products of these reactions were characterized in phase and chemical point of view. In order to study and describe setting and hardening processes of phosphate binders, the products were “in situ” analyzed by the thermal analyses and high-temperature diffraction analysis up to the 1300 °C. High temperature products were then characterized by means of phase and chemical composition and morphology.
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