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Educational Simulation in Task Situations (A survey focusing on the aspects of acceptance, interactivity, and authenticity)
Hannemann, Tereza ; Krykorková, Hana (advisor) ; Pinkas, Jaroslav (referee) ; Páchová, Anna (referee)
The dissertation 'Educational Simulation in Task Situations' is focused on a new medium - educational simulation, which is starting to establish itself in the field of education. This work is examining educational simulations from three different points of view: 1) the acceptance of educational simulations in the school environment, 2) the interactivity of learning material, and 3) the authenticity of learning material. The experimental results are divided into three separate chapters according to the respective viewpoint. The investigation focused on acceptance in the first chapter draws from the evaluation of 34 Czech teachers and more than 1000 students, who both evaluated the benefits and shortcomings of particular educational simulations that were used by the teachers and their students. The experiment on interactivity (N = 152) in the second chapter is focused on the experimental comparison of learning material with activated interactive features and learning material with deactivated features. The third experiment on authenticity (N = 48) compares teaching material using authentic media sequences and the same material converted into an animated form. All three main chapters contain a theoretical review of the respective topic and our own experimental research. The methodology is based on the...
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Draft modified winding technology of composite pipes
Bednár, Peter ; Pinkas, Jan (referee) ; Kandus, Bohumil (advisor)
This diploma thesis focuses on composite pipes production by winding of composite fibres soaked in resin binder and feeding with additional third type material simultaneously. It also describes the production machine FWMS180 and all of its additional devices necessary for the composites production by filament winding. The production process of composite pipes on the production machine FWMS180 is described in this paper as well as detailed description of the winding method. Furthermore, the technological bend and vibration tests procedures conducted on pipes of different material composition are discussed with related results and comparison. The thesis proves that presence of the third type material in composite pipes structure has different influence depending on observed and evaluated property.
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THE APPLICATION OF NANOMATERIALS FOR LEAD FREE SOLDERS DEVELOPMENT
Pešina, Zbyněk ; Pinkas, Jiří (referee) ; Spousta, Jiří (referee) ; Sopoušek, Jiří (advisor)
The present dissertation is motivated by the search for alternatives of lead-free soldering by nanoparticles of metals and their alloys. The research focuses on the possibility of replacing lead-free solders by nanoparticles. This issue is currently being addressed by the use of lead-free solders but their properties are not entirely equivalent to properties of lead-tin based alloys. The theoretical part of the dissertation first summarizes up-to date knowledge on the development of lead-free alloys currently used for soldering in the electronics. The work compares these lead-free solder candidates with previously used Pb-Sn alloys. The second section of the theoretical part is devoted to nanotechnology that offers possible solutions of problems associated with the use of lead-free solders. The text contains a description of the properties of nanocrystalline materials in comparison with those of compact alloys having the same chemical composition. The possibility of preparation of nanoparticles and potential problems associated with small particle sizes are also presented. Introduction of the experimental part focuses on the preparation of nanoparticles of pure metals and alloys by chemical and physical ways as well as on an instrumentation for characterisation and analysis. Attention is focused on the silver in nanoparticle form that exhibits the low temperature sintering effect, which is thermally activated by decomposition of oxide envelope covering the Ag nanoparticles. This factor is critical for low-temperature sintering and thus also for possible future applications. The thermal effects of the low sintering process were studied by methods of thermal analysis. The preparation of the Cu / Ag nano / Cu joints was carried out in-situ in inert atmosphere and under the action of atmospheric oxygen. In both cases varying conditions of thermal treatment were used. The cross sections of the prepared joints were then used for the metallographic analysis of the local mechanical properties of the resulting silver layer, for the chemical composition evaluation of the resulting layers of the joint, and for the microstructure study. Strength characteristics are represented by testing shear strength of individual joints.
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LC-NMR Analysis of Phenylsilane Polymers
Pinkas, Jiří ; Merna, J. ; Sýkora, Jan
We report the analysis of dehydrocoupling polymerization reactions of phenylsilane via on-flow LC-NMR experiment. The successful separation was achieved by isocratic elution of acetonitrile and aceton (80:20). The separation was solely monitored by 1H NMR detection. The properties of the polymeric product depend on the catalytical system. The products can differ in the molar weight distribution, degree of branching and amount of cyclic and rearranged products. In our particular cases, the weight average molar mass (Mw) varies from several silane units up to 4100 g.mol-1. The branching of polysilanes is monitored by 29Si{1H} INEPT experiment with the polarization transfer from the ortho hydrogen (J~7 Hz). The connectivity within branched unit was established via 1H à 29Si-29Si INEPT-INADEQUATE experiment.
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Alban Berg and his Lyric suite
Pinkas, Jiří ; Malý, Lubomír (advisor) ; Malý, Lubomír (advisor) ; Pěruška, Jan (referee) ; Štraus, Ivan (referee)
This thesis deals with an analysis of Lyric suite by Alban Berg concerning the little known facts based on the fascinating discovery of the annotated copy of the score from the year 1977. This score was prepared by the composer himself for Hanna Fuchs-Robettin. The analalysis explores the individual movements according to motives, numeric symbolism, symbolic tone rows and last but not least the thematic connections between the movements.
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Phase Equilibria in Systems for Lead-Free Solders
Vřešťál, J. ; Kroupa, Aleš ; Zemanová, Adéla ; Houserová, J. ; Pinkas, J.
In the year 2006,the optimization of parameters of systems Bi-Pd and Ag-In-Pd were completed by publications in articles and by addud of parameters to database COST 531. The optimisation of parameters for calculation of phase diagram of system Bi-Sb-Sn and In-Sb-Sn was performed and the results were publiced in Journal of Alloys and Compounds and parameters were added to database COST 531 and the optimisation of parameters in the system Cu-In-Sn was developing.
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