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Preparation of glass fiber/polyester composites
Horská, Pavlína ; Richtera, Lukáš (referee) ; Čech, Vladimír (advisor)
The bachelor thesis is aimed at an influence of surface modifications of fibrous reinforcements on mechanical properties at the fiber-matrix interface in fiber reinforced composites. Glass fibers were used as reinforcements and polyester resin was the matrix. The sample of composite consisted of polymer matrix in a form of cylindrical body placed on a bundle of glass fibers. The tensile test using a materials testing machine (Zwick) was employed to evaluate adhesion at the fiber-matrix interface. Untreated glass fibers and fibers with commercial sizing were used for fabrication of composite samples.
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Design of the Timber-Concrete Composite Ceiling Structure
Válek, Jakub ; Horák, David (referee) ; Švaříčková, Ivana (advisor)
The reconstruction of existing houses is currently a frequent issue. This work deals with the possibilities of reinforcing wooden ceilings with the focus on ceiling reinforcement using an over concrete slab. This suggested ceiling reconstruction work is desirable from the point of view of the rigidity of the object in the horizontal direction. The work includes the proposition for the composite, according to various norms and their comparison regarding the economic side of the design. The work further provides a description of the experiment, its preliminary results and its comparison with the theoretical calculation.
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Digital photography post-production and its purpose in commercial sphere
Polcíková, Michaela ; Krsek, Libor (advisor) ; Horný, Stanislav (referee)
Objective of this thesis is to define Photography Postproduction and present specific techniques of editing commercial photographs. Theoretical part is focused on the clarification of expression Photography Postproduction itself, it's understanding in the past and mainly actual application in distinct areas of commercial field. Practical part of this document elaborates on an implementation of digital composite. In separate steps are described different processes and reasons of their application. In addition, practical abstracts are included in form of photographs and videos, amending to the explanation of the techniques used. This assignment assume that a reader has basic understanding of a employed softwares, specifically Adobe Lightroom and Adobe Photoshop.
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METALLURGY AND PROPERTIES OF ADVANCED NiAl-Mo EUTECTICS
Barták, Tomáš ; Kuchařová, Květa ; Záležák, Tomáš ; Dlouhý, Antonín
A NiAl-Mo eutectic alloy was melt from 99,99% purity components and cast by the drop casting technique. The drop-cast ternary alloy (nominal composition of Ni-45Al-9Mo at. %), was re-melted and directionally solidified using a high temperature optical floating zone furnace. A resulting in-situ composite consists of Ni-45,2Al matrix and Mo-10Al-4Ni fibers, all in at. %. The volume fraction of 14% Mo-fibers stems from the eutectic composition. Backscatter diffraction shows that the NiAl-matrix and the Mo-fibers are both < 001 >-oriented with respect to the axis of the cylindrical rods. Preliminary creep experiments confirmed an immense improvement of high temperature strength due to the fine distribution of Mo-fibres. The amount of strengthening in terms of minimum creep rate can be as high as 7 orders of magnitude. Post-mortem transmission electron microscopy experiments provided evidence that creep in the temperature range of 800 - 900 degrees C results in an extensive formation of subgrain boundaries. The strengthening effect is very likely associated with the reactions between subgrain boundaries and fine Mo-fibres.
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Tungsten-Steel Composites and FGMs Produced by Hot Pressing
Matějíček, Jiří ; Boldyryeva, Hanna ; Brožek, Vlastimil ; Čižmárová, E. ; Pala, Zdeněk
Tungsten-steel composites and FGMs are being developed for potential application in plasma facing components of fusion devices. In this study, uniform composites and graded layers produced from tungsten and steel powders by hot pressing were investigated. Formation of dense composites with uniform distribution and good bonding of the phases was observed. A thin layer of intermetallic phase Fe7W6 formed at the interfaces. Thermal and mechanical properties of the composites in the as-produced and annealed state were characterized.
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Breathing Apparatus equipment in the Units of the Fire Rescue Service of the South Bohemia Region
SOKOL, Karel
The Fire Rescue Service of the Czech Republic is one of the fundamental components of the Integrated Rescue System. Its overall development and modern equipment allows for a very effective way to provide assistance in all types of emergencies. The breathing apparatus equipment is one of the many parts of the common personal protective equipment that allows firefighters to remain within even a stifling environment. The aim of this thesis was to make a full analysis of the numbers and the range of age in use of these kinds of breathing apparatuses and cylinders, which belong to the units of the equipment in the Fire Rescue Service of the South Bohemia Region. Furthermore, I have made a comparison between the two basic types of air breathing apparatuses that are being used, in terms of the protection period, which have been provided to the users (carriers). The participants of this inquiry were members of the FRS of the South Bohemia Region, which include the separation of chemical and technical services into the various local departments. I have received the data from twenty different fire stations in total. In the questionnaire which was given, I collected the data from the respondents, according to their age and added the number of different types of breathing apparatus and cylinders and period or time of use to this study. The data was collected during February and March 2010. Hypothesis 1: the number of pieces of the breathing apparatus equipment in the South Bohemia Fire Rescue units is sufficient; this was confirmed. The result has been compared with the numerical data collected from the indicated positions in the current legislation set to 1.7 times of the number of the members serving in one inning. Hypothesis 2: that these breathing apparatuses meet the requirements of all of the current legislation; this has not been confirmed. The result shows a comparison of the technical parameters of the instruments and technical conditions, as reported by the Interior Ministry decree No. 255/1999 Coll. as amended, regarding the technical conditions kind of fire. The results will be used to establish the financial balance sheet and the planned purchases of the pressurized breathing apparatus equipment and the used variations of the composite cylinders.
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