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Study of behavior of concrete and cement based composite materials exposed to high temperatures
Bodnárová, L. ; Horák, D. ; Válek, J. ; Hela, R. ; Sitek, Libor
The paper describes possibilities of observation of behaviour of concrete and cement based composite material exposed to high temperatures. Nowadays, for large-scale tests of behaviour of concrete exposed to high temperatures, testing devices of certified fire testing stations in the Czech Republic and surrounding states are used. These tests are quite expensive. For experimental verification of smaller test specimens, a testing device was built at the Technical University in Brno, where tests of thermal loading of concrete tests specimens of various sizes can be carried out (dimensions up to 800 x 800 x 800 mm or slabs up to 1100 mm of length). The testing device opens new ways of observation of behaviour of concrete and cement based composite materials exposed to high temperatures as well as preparation of specimens for observation of interaction of water jet and concrete degraded by action of high temperatures.
Fulltext: content.csg -  DOC
Plný tet: UGN_0398264 - DOC
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Light Induced Degradation of Solar Cells
Indra, Jiří ; Solčanský, Marek (referee) ; Vaněk, Jiří (advisor)
This master’s thesis deals with light induced degradation problems. In theoretical section it describes essentials of PN junction function and next light induced degradation mechanisms of solar cells and its symptoms at solar cell operation. In practical section it deals with set of measurements of solar cells since production of the silicon wafer to the complete solar cell. Selected cells are submitted to light induced degradation, measured dependencies are then evaluated. Degraded samples are subsequently recovered by two ways at high temperature treatment. The issues are evaluated.
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How are high school students informed about virus biology
Solarová, Pavlína ; Drda Morávková, Alena (advisor) ; Fraiberk, Martin (referee)
Biology is the study of viruses, which are engaged in teaching 2-3 lessons. During those hours, students must not only absorb information about the structure and function of the virus, but also the reproduction of the organism, several representatives and, ultimately, diseases that cause that exists prevention and treatment these diseases. Students remember what it is for the vaccine, the virus infects whom, how they can get infected or what the immune system. What makes the problem of students are questions: which of the viral disease is, what constitutes a viral particle, or what is an infectious disease. In the RVP G is determined curriculum is very vaguely. The teacher thus has a certain freedom in creating the ŠVP and its preparations. To more precise what students should know for graduation, testing requirements used common catalog of the school-leaving examination in this case of biology, who has broken the outputs of the curriculum of all biological disciplines.
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Multidisciplinary care in hemodialysis centers.
VYHLIDALOVÁ, Mária
It is inconceivable for only one person to take care of ill people in a health care. To achieve the aim which is in particular maintenance of the highest life quality of specimens in health or in disease, is important mutual cooperation of professionals in the branch, where every single ensure care for a patient on the basis of his own knowledge and skills. It is about team co-operation, where every single member of the team has his own obligations, but also rights and authority. The term multisiciplinary care means co-operation of more scientific branches. Hemodialysis patients'nursing care is about team of professionals, who are fully involved in satisfying patients' needs. This co-operation enables primarily the unitary communication, reduction of patient's issue analysis, unified and consecutive nursing care, complete documentation and quality evaluation of provided nursing care of these patients. The aim of the dissertation was to chart multidicsiplinary care's issues at hemodialysis, on the basis of available literature. The dissertation is based on theoretically processed topic by the method of documents' content analysis and method of review and synthesis. Information is obtained from domestic but also foreign science books, scientific magazines, and internet sources. Findings from the 42nd international conference EDTNA/ERCA, which topic was Innovation of renal care through multi-professional leadership, which took place in Malmö, Sweden, from 31st of August to 3rd of September 2013, also contributed. The dissertation is divided into three basic chapters. The first part is focused on team characteristic. There are definitions, types, features, building, composition, roles, conflicts within a team and elemental description of multidisciplinary co-operation. The second chapter deals with a history and hemodialysis as a medical extracorporal method. The third, and the broadest section, is focused on multidisciplinary co-operation at the centre of hemodialysis. It is divided into several sub-chapters. In each of them the information descend from general field to concrete needs of hemodialysed patient and continue to the description of each member of a multidisciplinary team. The result is comprehensive view on provision of multidisciplinary care in the centres of hemodialysis. The output of the dissertation is a draft of the nursing care algorithm within the purview of multidisciplinary care at the centres of hemodialysis. Multidisciplinary care is necessary requirement for assumption of effective, high quality and continuous medical and nursing care at all the centres.
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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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Sorption and Stabilization of Metals/Mettalloids by Innovative Synthesized Sorbent Amochar.
Ouředníček, P. ; Trakal, L. ; Komárek, M. ; Pohořelý, Michael
Remediation of contaminated soil which is based on stabilization and immobilization of potential\nhazardous substance by sorption materials has been studied intensively nowadays. Biochar – activated organic carbon belongs to this group of stabilizing agents which can adsorb wide range of contaminants, including metals/metalloids. Surface area of the biochars is quite large in general and functional groups (e.g. COO–) can form chelates or alkaline elements on the surface, which is represented by cation exchange capacity. Altogether with the high pH values (7.00 – 10.00), biochars are quite effective sorbents and can adsorb metals/metalloids from the solution (ground water), especially in acidic soils (in the environments affected by intensive mining activities). Sorption\neffectiveness can be increased (especially for As (V) or Cr (VI) sorption) by modification of biochar by various types of secondary oxides. Innovative sorbent AMOchar (AMO + biochar) has been synthesized currently. The product was prepared by adding of biochar to the reaction solution during amorphous manganese oxide (AMO) synthesis. The AMOchar was formed mainly by Mn-oxalates which had coated surface of the pristine biochar. AMOchar composite was able to remove significantly higher amounts of various metal(loid)s from the solution despite the rather high pH of the material. Sorption effectiveness was high not only in case of Pb (II) sorption (almost 99%), and Cd(II) (51.2%), but also a very high amount of As(V), 91.4%. Additionally, both AMOchar composite was able to reduce Mn leaching. This can avoid potential post-contamination caused by the dissolution of less stable Mn-oxalates as observed in the pure AMO.
Fulltext: content.csg -  PDF
Plný tet: SKMBT_22316111113040 - PDF
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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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Determination of content substances for selected species and varieties of roses.
Slavíková, Eva ; Sus, Josef (advisor) ; Súkeníková, Tereza (referee)
This bachelor's work is focused on comparing the most significant content substance, vitamin C, in fruits of chosen rose kinds species and varieties. Herbal products are often seen by people as products of "second choice", when failure of allopathic treatment occurs, which is focused especially on suppressing symptoms of illness, but it ignores health of the human body as whole. That's why are herbal products often alternative for therapy of chronic diseases. The base of this work is extensive literary research and results of laboratory measurings. Literary part of this work includes description of botanical classification of rose plants. There is stated basic characteristic of individual rose species and their morphological features. In following chapters is composed overview of effective substances in rose fruits and their effect on human health. In practical part of this work are included results of laboratory tests for determining ascorbic acid content for chosen samples of rose species and it also includes results of weighing and measuring of fruit samples of chosen rose species. There are also stated chosen rose species and shortly their origin and description, in the beginning of practical part. For practical part were chosen samples of species. Results of practical part are compiled into statistic tables and graphs and it confirms high content of ascorbic acid in rose fruits. This content is in range of cca 300 - 900 mg.100 g-1. Due to growing interest in alternative treatment options and "clean" natural product, it can be assumed, that many plants of Rosaceae family will keep its place in treatment practice. Those plants will be used not only for treatment of acute and chronic diseases, but also for cosmetic products production, thanks to its large effects and process options.
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Arctic tundra dendrochronology
Lehejček, Jiří ; Svoboda, Miroslav (advisor) ; Monika, Monika (referee)
Historically unprecedented environmental change in the Arctic ecosystems is often given into the context of its past and possible future development. In the region where instrumental meteorological observations are scarce archives need to be investigated in order to address this issues. The comprehensive synthesis one of the archives: long-live circumpolar evergreen Juniperus communis L. shrub is presented here. 20 individuals from southwest Greenland were investigated at the cell anatomy level to understand the ecology of the species and unhide its potential for environmental and climate reconstructions. The findings are as follows:
i) Stop of exponential cross-sectional conduit-lumen widening with increasing age is in contrast with conduit-lumen nature of trees. This indicates that shrubs do not need to saturate their water and nutrient demands via traits of classical hydraulic conductivity law but rather developed different mechanisms. Extreme weather conditions result in prostrate growth form. However, different weather factors probably influence shrub growth differently: While snow and wind act mechanically (a), temperature influences the form of growth physiologically (b). a) So long as the young shrub stem has high resilience to bend back to an upright position after snow melt and so long as it can withstand the wind during the vegetation season it most likely grows upright and the conduit-lumens widen. b) Temperature, resp. freeze-thaw events are responsible for the shrubs preference of safety (finite size of conduit-lumens) over hydraulic efficiency, thus not allowing for more primary growth. All of these (and other) factors are apparently working together and the transition of vertical to more horizontal growth is gradual. As a consequence, the conduit-lumen sizes may not have to be further increased (due to ecophysiological restrictions possibly also must not) because water is no longer transported against gravity.
ii) Observed age/growth trend has to be taken into consideration for further employment of the wood anatomical parameter in paleoenvironmental studies. That is, shrub cell parameters can only be used for this purposes if correctly detrended. This allows for more accurate as well as longer reconstructions because youth trend was often neglected in reconstructions based on shrub annual-rings.
iii) The south-western Greenland Ice-Sheet (GrIS) melt rates reconstruction is presented for the whole 20th century. This part of GrIS is considered as the most active. According to the presented reconstruction current GrIS melt rates are not uncommon for the last century being comparable to first decades of 20th century. This finding is particularly important contribution to the debate on Atlantic meridional overturning circulation (AMOC). Too high fresh water inputs into the Northern Atlantic from GrIS melting may slow down or even stop the AMOC which would result in more continental climate in Europe. Presented results indicate that this threshold lies higher than observed current melt rates of GrIS.
Fascinating Juniperus comunnis species has shown to be able to address many ecological as well as environmental open questions and due to its longevity and abundant distribution has a great potential to become an important player in the Arctic research.
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