National Repository of Grey Literature 13 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
Effect of selected activators on the properties of alkali-activated composites reinforced with basalt fibers
Švardala, Daniel ; Hrubý, Petr (referee) ; Kalina, Lukáš (advisor)
This paper deals with the alkali activated materials (AAM) applicable as a construction material, thanks to low cost, environmental friendliness and good mechanical properties. The goal of this thesis is to search for suitable alkaline activator with respect to the final properties of alkali activated composite reinforced with basalt fibers. This thesis is focused on the determination the effect of basalt fibers addition on the mechanical properties. The influence of alkaline activator to basalt reinforcement was determined by simply strength tests, like the compressive and flexural strength measurements. The matrix fiber interaction, as one of the main parameters indicating the quality of the material reinforcement, was measured by electron scanning microscope equipped with an X ray energy dispersing analyzer (SEM EDS). It was found out that the most significant effect on the improvement of the mechanical properties of alkali activated material was in the case of the samples activated by sodium and lithium waterglass. The mechanical strength of these reinforced materials was considerably higher compared to non reinforced samples. AAM activated by potassium waterglass with and without the basalt reinforcement indicates the same or very similar mechanical strength. The comparison of composites with different alkaline activator leads to the conclusion that the mechanical properties depend on the type of used waterglass. AAM activated by sodium waterglass achieve the highest strengths compared to potassium and lithium waterglass activated materials and therefore seems to be the most appropriate for basalt fiber composites preparation.
Utilization of basalt fibers in alkali activated materials
Hrubý, Petr ; Šoukal, František (referee) ; Kalina, Lukáš (advisor)
Alkali activated materials (AAMs) represent construction materials with a huge potential especially because of environmental and economic aspects but sufficient mechanical properties as well. A fibre or fabric reinforcement of the AAMs could support more widespread application potential due to the mechanical properties, fracture toughness or composite durability improvement. Various alkaline activators were used for a blast furnace slag (BFS) activation to produce a suitable matrix for basalt fibres (BF) implementation in this thesis. The BFs represent applicable reinforcing material because of its favourable mechanical and thermal properties. Still, the utilization of BFs in the AAMs is quite limited due to the fibres low chemical stability under the alkaline conditions. Accelerated leaching tests with a determination of basalt fibres chemical composition same as tensile strength change using various analytical techniques (XRD, XPS, SEM-EDX, ICP-OES) have confirmed these assumptions. An influence of basalt fabric reinforcement in one or more layers on the mechanical properties was determined with the meaning of the compressive and flexural strengths. The fibre/matrix adhesion and transition zone properties were studied using SEM-EDX and pull-out tests as well because they are crucial parameters for the composite material reinforcement efficiency.
Historical landscape of the Bohemian-Moravian Highlands. Settlement from prehistoric to late medieval times
Bajer, Aleš ; Bísko, Richard ; Dejmal, Miroslav ; Hrubý, Petr ; Malý, Karel ; Mazáčková, Jana ; Machová, Barbora ; Milo, Peter ; Plaček, Miroslav ; Šabatová, Klára ; Těsnohlídek, Jakub ; Zimola, David ; Žahourková, Alena ; Hejhal, Petr
The exhibition catalogue is one of the important possibilities how make public the facts about historical landscape of the Bohemian-Moravian Highlands, the preservation of the archaeological monuments, stay of the knowledge and possibilities of their documentation. The good knowledge increases the chances of preservation of unique information’s about our own past in the landscape. Landscape currently is the most significant witness of historical and cultural changes in our country. And as regards the state of preservation of prehistoric archaeological monuments, landscape even is the only witness. One of extraordinary regions in this regard is the Bohemian-Moravian Highlands. It always was and still is a peripheral region, which is not really significantly affected by the ongoing destruction of historical cultural landscape. In chapters of the exhibition catalogue are introduced the issues of research. The catalogue of artefacts documenting the material culture for all investigated periods is published at the end.
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High mediaeval mining settlemens, focused on site Kremsiger (Přísečnice district).
Derner, Kryštof ; Hrubý, Petr (advisor) ; Schwabenicky, Wolfgang (referee)
(in English): The issue is focused on the survey and dig on the mining settlement Kremsiger in Ore Mountain. We discovered well planed and perhaps measured urbanism of the site. Our excavation took luckily place on the house with traces of ore assaing activity. In the issue we discuss the possibility of ore smelting directly on the mining settlements. We found out, that this activity is not exceptional, although there is no evident reason for avoiding the smelting in central smelting places. Second, the excavation brought the biggest assemblage of high mediaeval ceramic. Its analysis pointed out, that the settlement lived through two different ceramic horizonts, and due to this fact was not extremely short-living place as could be expected by mining settlement generally. Despite some exclusive finds as hollow glas, or the urbanism, we neglect the possibility of township of the site. There is no evidence for growth of mining settlement in such vicinity as by Kremsiger and the mediaeval Town Přísečnice.
Phenomenon of water in mining - gold panning, findings of ore mills in Slovakia.
Fajta, Martin ; Labuda, Jozef (advisor) ; Hrubý, Petr (referee)
Fajta, M. 2015: Phenomenon of water in mining - gold panning, findings of ore mills in Slovakia. [Master's thesis] Water has always been closely associated with the mining and processing of precious metals. Either it served as a secondary source from which gold was gained by gold-washing, or as a tool for further processing of primary mined ore. Thesis is divided into two sections which describe both of these options. In the first part, thesis deals with gold-panning. It describes sources for the history study of gold-panning in Slovakia and it presents current state of research. On the basis of historical knowledge from "De Re Metallica libri XII." (G. Agricola 1556) are presented the different types of chutes, which are used for gold-washing. This section also includes excursion about mining archaeology and excursion about origin and appearance of gold in Slovakia. The second part describes different steps in the processing of primary mined ores. Since there was no archaeological research of medieval facilities for processing ores in Slovakia, in the paper are presented examples of two researches of mining facilities from Czech Republic. In the chapters describing processing of ores is the biggest attention devoted to ore mills. The most common evidence for the existence of such mills are...
Reduction of hexavalent chromium in cement binders
Hrubý, Petr ; Šoukal, František (referee) ; Kalina, Lukáš (advisor)
The issue of hexavalent chromium contained in cement binders and the possibilities of its reduction are very current, due to the toxicity of Cr (VI) and constantly stricter regulations of the EU. The effort of achieving a cement binder with Cr (VI) concentration lower than 2 ppm and keeping this concentration unchanged during the long term storage is a frequently studied issue which needs to be solved. Requirements are put on the low cost for industrial use and without inducing changes of final properties of cement binders. A reducing agents based on iron (II) sulphate monohydrate potentially combined with some additives were studied in this study. The efficiency of reducing agents was analysed by commonly used UV-VIS spectrophotometry technique which uses 1,5-diphenylcarbazide as an indicator. The influence of added reducing agent on the mechanical properties was noticed by compressive strength test.
Metodika dokumentace drobných památek
Hrubý, Petr ; Altová, Eva ; Kadlec, Antonín
Předkládaná metodická publikace si klade za cíl popsat základní principy dokumentace drobných památek. V první řadě jednoduchými metodami, které jsou vesměs jednoduše dostupné všem dokumentátorům a badatelům, kteří se drobnými památkami za- bývají či chtějí zabývat. V druhém plánu jsou popsány a naznačeny cesty složitějších a specializovanějších dokumentačních metod vyžadující však specializovanou techniku a znalost příslušných dovedností.
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Analysis of working with fan SK Dynamo České Budějovice
Hrubý, Petr ; Kotáb, Jiří (advisor) ; Kuchár, Róbert (referee)
The aim of this thesis is to identify and analyse factors affecting the attendance of domestic football matches of SK Dynamo club České Budějovice. The main emphasis is placed on working with fans. The theoretical part relates to the topic and focuses on the determining factors of demand for sport events, the sport product theory and phenomenon of a fan. The practical part introduces the club SK Dynamo České Budějovice more closely and analyses individual factors affecting demand for the club's matches and defines the significance of these factors. A chapter on working with the fans follows. At first the elements of sport product are characterised and secondly the club marketing elements. The practical section chapters are underpinned by the results of a survey which was carried out among the fans of SK Dynamo České Budějovice. The discourse and conclusion summarize the analysed results, evaluates working with fans and last but not least outlines possible steps for improvements of attendance and working with club's fans.

National Repository of Grey Literature : 13 records found   1 - 10next  jump to record:
See also: similar author names
2 Hrubý, Patrik
5 Hrubý, Pavel
9 Hrubý, Petr
2 Hrubý, Přemysl
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