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Measurement of Water Uptake of Historic Surfaces-State of the Art Review
Zíma, Pavel
In situ testing of material water uptake represents one of very basic and indispensable techniques in the conservation practice aiming different purposes. Water uptake of porous building materials used on historical constructions significantly correlated to some other materials characteristics. Capillary properties of porous materials can be measured by means of Karsten tube and modified tools of methods. A pilot prototype of one of them has been developed and tested in ITAM AS CR for measuring water absorption under low pressure. The device has output connector for linking to a computer and reading the stored data. The device was tested in laboratory as well as in situ for a basic performance. The acquired data were evaluated using software specially writen for this purpose in MatLab.
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The creation of videotutorials for the University of Economics, Prague
Zeman, Ondřej ; Šedivá, Zuzana (advisor) ; Kupec, Michael (referee)
The purpose of this bachelor thesis is to acquaint readers with new possibilities of teaching by using information technology and its application, when making learning material. The main outputs of this thesis are video tutorials, which serve as an education support for the course 4IT110 Use MS Excel in business practice taught in the University of Economics, Prague. However, it may be useful to other students of different courses. The process of making tutorials is described from the very beginning by specifying methodology, creating model exercises, subsequent testing of tutorials by students and optimisation of videos according to their suggestions and comments.
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Changes in structure and phase composition in the surface of tram rail
Švábenská, Eva ; Roupcová, Pavla ; Schneeweiss, Oldřich
We have investigated structure and phase composition of surface layer of tram rails after long time running and the results were compared with those obtained on the original part of material. Changes due to effects of severe plastic deformation together with thermal shocks by friction process were expected. The information about structure and phase composition was obtained by optical and scanning electron microscopy, X-Ray Powder Diffraction, Mössbauer Spectroscopy and Glow Discharge Emission Spectroscopy (GDOES) and this was completed by microhardness measurements. The results show that the surface layer in comparison with the original material exhibits important changes in grain structure, an increase in microhardness and high content of iron oxide and hydrooxides. According to the depth profile of the chemical composition measured by GDOES there is an increase in carbon content in the surface layer which can be effect of up-hill diffusion.
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STRAIN ENGINEERING OF THE ELECTRONIC STRUCTURE OF 2D MATERIALS
del Corro, Elena ; Peňa-Alvarez, M. ; Morales-García, A. ; Bouša, Milan ; Řáhová, Jaroslava ; Kavan, Ladislav ; Kalbáč, Martin ; Frank, Otakar
The research on graphene has attracted much attention since its first successful preparation in 2004. It possesses many unique properties, such as an extreme stiffness and strength, high electron mobility, ballistic transport even at room temperature, superior thermal conductivity and many others. The affection for graphene was followed swiftly by a keen interest in other two dimensional materials like transition metal dichalcogenides. As has been predicted and in part proven experimentally, the electronic properties of these materials can be modified by various means. The most common ones include covalent or non-covalent chemistry, electrochemical, gate or atomic doping, or quantum confinement. None of these methods has proven universal enough in terms of the devices' characteristics or scalability. However, another approach is known mechanical strain/stress, but experiments in that direction are scarce, in spite of their high promises.\nThe primary challenge consists in the understanding of the mechanical properties of 2D materials and in the ability to quantify the lattice deformation. Several techniques can be then used to apply strain to the specimens and thus to induce changes in their electronic structure. We will review their basic concepts and some of the examples so far documented experimentally and/or theoretically.
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ELECTRON BEAM REMELTING OF PLASMA SPRAYED ALUMINA COATINGS
Matějíček, Jiří ; Veverka, J. ; Čížek, J. ; Kouřil, J.
Plasma sprayed alumina coatings find numerous applications in various fields, where they enhance the properties of the base material. Examples include thermal barriers, wear resistance, electrical insulation, and diffusion and corrosion barriers. A typical structure of plasma sprayed coatings, containing a multitude of voids and imperfectly bonded interfaces, gives them unique properties - particularly low thermal conductivity, high strain tolerance, etc. However, for certain applications such as permeation barriers or wear resistance, these voids may be detrimental.\nThis paper reports on the first experiments with remelting of plasma sprayed alumina coatings by electron beam technology, with the purpose of densifying the coatings and thereby eliminating the voids. Throughout the study, several parameters of the e-beam device were varied - beam current, traverse velocity and number of passes. The treated coatings were observed by light and electron microscopy and the thickness, structure and surface morphology of the remelted layer were determined and correlated with the process parameters. Based on the first series of experiments, the e-beam settings leading to dense and smooth remelted layer of sufficient thickness were obtained. In this layer, a change of phase composition and a marked increase in hardness were observed.\n
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The Liberation of Pilsen 1945 in Photography
Křenová, Tereza ; SILVERIO, Robert (advisor) ; JANOŠČÍK, Václav (referee)
This bachelor thesis deals with liberation of Pilsen in May 1945 by american army in photography. The aim of this thesis is finding and collecting archival materials and placing them in a historical-political context. Communist regime changed the portrayal of historical events and directly influenced the amount of exisiting photographs, documents and lives of those who created them. Important part of this bachelor thesis is working with those archival materials – particularly with photographs capturing arrival of Americans and their stay in Czechoslovakia at the end of WW2. Both professional and amateur photographers created valuable photographs as they witnessed the liberation of Pilsen. These photographs became in spite of communist propaganda a clear evidence that Pilsen was liberated by american army.
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San Minn (or) An Artist who prefer creating and paintings than his life
Zeya, Pyin Nyar ; JANEČEK, Vít (advisor) ; VOJTĚCHOVSKÝ, Miloš (referee)
No one can control a painter artist’s freely thoughts and ideas and although his paintings were under the high pressure and banned by force, the artistic value of his materials never go down. So that I am writing this paper.
He, San Minn has broken out the mainstream of Burmese painting field, he never made business paintings as well. He keeps his belief on the art of paints and he is always finding for the new way to make his paintings. His materials are very different from other Burmese painter artists’ materials. His style is unique in Burmese paintings. So I can get a chance to study of his style, ideas, ways of thinking and his determination on the art works.
My paper can show a painter artist’s life who grew up under the military rule for 50 years and the situation and history of Burmese painting field. Then not only people who are studying the painting subject, but also other people can know about the subject of Burmese painting and field of artists. I dare say that my paper must be colorful and fruitful.
As a painter artist, it seems that he wants his audience to feel his materials but he rare to show his real life behind the pictures. For me, I can get a chance to know about his real life for my thesis paper.
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Thesis Statement
My thesis can be useful for everybody who is interested in Burmese contemporary art field.
This is the biggest chance to read about one of the most famous, important and significant artists and art movements of Burma. His paintings are reflecting his journey through over 40 years of censorship, but he was not afraid to tackle political and social issues.
Many of San Minn's art works are based on autobiographical, making sharp social commentary on the popular culture, social values and scenario circumstances where he has lived in.
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Plasma spraying from liquids: plasma liquid interaction and coating build up
Tesař, Tomáš ; Mušálek, Radek ; Medřický, Jan ; Lukáč, František
Plasma spraying from liquid feedstocks is a rapidly developing field of thermal spraying since the coatings prepared from liquids exhibit some unique features, such as high hardness, thermal shock resistance or low thermal and electric conductivity. The key factor influencing the final coating character and properties is the input material which may be in the form of a suspension or a solution. Parameters of the selected suspension (solids concentration, viscosity, surface tension, chemical composition, etc.) or solution (concentration, etc.) determine its interaction with the plasma jet which strongly influences the coating buildup. This proceeding introduces the problematics of the interaction between the liquid feedstock material with the plasma jet and presents the way of evaluation of the coating buildup.
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