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Microstructural Investigation and Mechanical Testing of an Ultrafine-grained Austenitic Stainless Steel
Chlupová, Alice ; Man, Jiří ; Polák, Jaroslav ; Karjalainen, L. P.
Special thermomechanical treatment based on high degree deformation followed by reversion annealing was applied to 301LN austenitic stainless steel to achieve ultrafine-grained (UFG) structure with considerably enhanced mechanical properties. Two different conditions of the thermomechanical treatment were adopted and resulting microstructures with different grain sizes were characterised by optical and high resolution scanning electron microscopy (SEM-FEG). Hardness measurements and tensile tests were performed to characterize mechanical properties. To reveal structural changes induced during thermomechanical treatment and during tensile tests a magnetic induction method was additionally applied. Experimental study validated the ability of the above special treatment to produce austenitic stainless steel with grain size about 1.4 m which exhibits tensile strength about 1000MPa while ductility remains on level about 60 %. The results obtained for both thermomechanical conditions are compared and the relationship between microstructure refinement, phase content and mechanical properties is discussed.
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Single particle analysis of size-segregated aerosol in Prague city center
Marvanová, S. ; Skoupý, Radim ; Kulich, P. ; Bendl, J. ; Hovorka, J. ; Machala, M.
Particulate matter (PM) is omnipresent pollutant in the ambient air known to cause cardiovascular and respiratory diseases (WHO 2004). Recently, outdoor air pollution and particulate matter in outdoor air pollution were classified as carcinogenic to humans, Group 1 (IARC 2015). Especially, ambient PM of aerodynamic diameter < 100 nm, ultrafine particles, appears to be of great importance due to its high specific surface area and high number concentration (Hughes et al. 1998). Ultrafine particles also easily enter and are being transferred in organisms, and interact with cells and subcellular components (Oberdorster et al. 2005). As the evidence of ultrafine PM significance increased, size-fractionated PMs sampled by various cascade impactors have been employed into the toxicological studies on cell cultures or isolated cells, using the organic extracts of size-fractionated PMs (Topinka et al. 2013, Topinka et al. 2015) or directly the size-fractionated particles (Becker et al. 2003, Ramgolam et al. 2009, Reibman et al. 2002, Loxham et al. 2013, Jalava et al. 2006, Thomson et al. 2015, Jalava et al. 2015). The aim of this study was to evaluate shape and composition of size-segregated aerosol particles, sampled by high volume cascade impactor, using electron microscopy and energy dispersive X-ray spectroscopy (EDX).
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Black Chromia Plating for the Solar Radiation Absorbers
Brožek, Vlastimil ; Březina, Václav ; Brom, Petr ; Kubatík, Tomáš František ; Vilémová, Monika ; Mastný, L. ; Novák, M.
Black chromia layers were produced on copper, zirconium and aluminium substrates. These layers are aimed to serve as solar collectors. Efficiency of the layers during UV-VIS, UV radiation and WSP® plasma torch radiation is described. The chromia layers were prepared by a new procedure, i.e. deposition of ammonium dichromate solution using plasma torch or so called Liquid Precursor Plasma Spraying (LPPS). Solution of ammonium dichromate is fed into plasma stream, where dissociation takes place under temperatures of 4000 K – 25000 K. Up to nanometric oxide particles can be produced; the resulting size is dependent on solution concentration and feeding nozzle diameter. The particles impact on substrate and form coating. Using 2 wt.% to 5 wt.% solution of ammonium dichromate and feeding nozzle of 0.2 mm in diameter is the size of produced chromia particles about 6 µm which results in formation of 2 µm to 3 µm thick coating, i.e. according to the theory an optimal thickness 2.5 um for absorption layers, necessary condition for formation energy traps for IR radiation emitters up to 100°C. Moreover, black chromia coating is a suitable corrosion barrier of metallic substrates. \n\n
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Simulace a protiřetězce pro efektivní práci s konečnými automaty
Holík, Lukáš ; Černá, Ivana (referee) ; Jančar, Petr (referee) ; Vojnar, Tomáš (advisor)
Cílem této práce je vývoj technik umožňujících praktické využití nedeterministických konečných automatů, zejména nedeterministických stromových automatů. Jde zvláště o techniky pro redukci velikosti a testování jazykové inkluze, jež hrají zásadní roli v mnoha oblastech aplikace konečných automatů. V oblasti redukce velikosti vycházíme z dobře známých metod pro slovní automaty které jsou založeny na relacích simulace. Navrhli jsme efektivní algoritmy pro výpočet stromových variant simulačních relací a identifikovali jsme nový typ relace založený na kombinaci takzvaných horních a dolních simulací nad stromovými automaty. Tyto kombinované relace jsou zvláště vhodné pro redukci velikosti automatů slučováním stavů. Navržený princip kombinace relací simulace je relevantní i pro slovní automaty. Náš přínos v oblasti testování jazykové inkluze je dvojí. Nejprve jsme zobecnili na stromové automaty takzvané protiřetězcové algoritmy, které byly původně navrženy pro slovními automaty. Dále se nám podařilo použitím simulačních relací výrazně zefektivnit protiřetězcové algoritmy pro testování jazykové inkluze jak pro slovní, tak pro stromové automaty. Relevanci našich technik pro praxi jsme demonstrovali jejich nasazením v rámci regulárního stromového model checkingu, což je verifikační metoda založená na stromových automatech. Použití našich algoritmů zde vedlo k výraznému zrychlení a zvětšení škálovatelnosti celé metody. Základní myšlenky našich algoritmů pro redukci velikosti automatů a testování jazykové inkluze jsou aplikovatelné i na jiné typy automatů. Příkladem jsou naše redukční techniky pro alternující Büchiho automaty prezentované v poslední části práce.
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Small Size Municipality Revenues in Czech Republic
JIREKOVÁ, Kateřina
The aim of this thesis is to evaluate the system of municipality incomes in the Czech Republic with respect to specifics of small municipalities. In last few years these municipalities have become a frequently discussed topic because of their lower incomes. The legislation has been devoting to this problem since 2008 and the differences between large and small municipalities in the Czech Republic were removed. There is income analysis of all municipalities in the Czech Republic from 2000 up to 2012 in this thesis. The municipalities were divided into two groups. The first group contains small villages, defined as municipalities up to 499 inhabitants. In the second group there are other municipalities of the Czech Republic except small villages, statutory cities and the Capital City of Prague. The real data were recalculated per head for this analysis and minimum, maximum, median and arithmetic mean were found. Variability of incomes is evaluated from these results. Regression and correlation analysis is made in some groups of revenues because of finding dependence among variables. Disparity in incomes of small towns and other communities is assessed by comparing the arithmetic means and medians between groups of municipalities using a Two-Sample t-test and Mann-Whitney test. Revenue growth is evaluated determination of the trends of the time series using linear regression. Some specifics in financing small villages were found from these analyzes. There was also confirmation of the hypothesis that small municipalities have lower incomes per an inhabitant.
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Gastrointestinal nematodes in wild ruminants from Czech Republic
Heinclová, Pavla ; Langrová, Iva (advisor) ; Vynikalová, Lucie (referee)
This study is focused on the occurrence of gastrointestinal nematodes in cervids in the Czech Republic. The aim of the study was to determine the species composition of gastrointestinal nematodes of roe deer (Capreolus capreolus) and fallow deer (Dama dama) . Research on presence of parasites in the digestive tract of roe deer and falow deer was done by using autopsy which was performed in the laboratory of the Department of Zoology and Fisheries FAPPZ CULS Prague according to K. I. Skrjabin.
Autopsy material was extracted from small intestine of the captured pieces during the years 2009 - 2014. Research was done on 15 deer coming from Central Bohemia, Ústí and Liberec region. For determination were used microscope and determination key. Among determination characteristics determined in females include overall length of the body width, shape and size of the vulva, the presence of flaps, vulva distance from the anus, the shape of the end of the body. Males observed features: overall length, size and shape of spicules, gubernaculum.
Among the common features observed included the formation of the pharynx and oral capsule. Each of the nematode was measured and incorporated into species and genera. Result shows nematodes: Trichostrongylus capricola, Nematodirus fillicolis venulosum and Oesophagostomum, Cooperia pectinata and subsequently evaluated prevalence.
From the results of the autopsy of the small intestine shows that the highest prevalence rate among deer and fallow deer reaches Trichostrongylus capricola (60 %) and Nematodirus filicollis (20 %). The lowest prevalence consistently achieve Oesophagostomum venulosum and Cooperia pectinata (6.7 %). The prevalence was consistent with studies carried out in other European countries. In comparison with studies in the Czech Republic with Trichostrongylus capricola was compared to another research from 2008 to decrease prevalence.
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An evaluation of erosion risks and design of erosion control measures in selected cadastral area
Janota, Petr ; Janků, Jaroslava (advisor) ; Karel, Karel (referee)
Erosion is exogenous geomorphological process that affects the formation of the Earth's surface since the formation of the Earth's solid crust. This activity, which under natural conditions proceeded slowly, in terms of human generations imperceptibly, in intensively used landscape dramatically accelerated and brought a number of adverse consequences. The aim of this study has been to assess and evaluate erosion risks in selected cadastral area and in the event of an over limit erosion hazard to suggest appropriate erosion control measures to eliminate the increased erosion.
The 77 erosion of closed units were examined by a computer program Atlas DMT erosion module, which uses digital terrain model together with data from databases or BPEJ or LPIS. The 14 of them have diagnosed overlimit value wash away the soil. As a basic erosion control measures the change of applied classic crop rotation to crop rotations using soil conservation technologies was considered. After adjusting cropping practices that positively impact factor of the protective effects of vegetation, it was found by erosion Atlas module, six parcels of land with over limited value of soil washes. These lands have suggested the use of technical erosion control measures, for example furrows, grassing thalwegs etc.. On the parcels, where, due to their size, shape or morphology technical measures proved inadequate or ineffective it has been proposed permanent grassing.
In the proposals erosion control measures it is necessary to combine the maximum efficiency of measures with condition of ease and minimal restriction of land users. When their making is to be assumed towards the user, because it depends on him only whether the proposed organizational and agronomic measures will be implemented or not. The fundamental problem with these measures is that their implementation is not backed by legislation. I assume that the more acceptable, less restrictive and inexpensive measures will be proposed, the more likely it will be implemented. One of the reasons why even the simple erosion control measures are put into practice slowly and with difficulty is the fact that in the Czech Republic the most of the agricultural land is managed by entities that are not its owners. This fact significantly contributes to the fact that land is viewed merely as a means of production, which must to bring maximum profit only. To improve this situation may also contribute to the establishment and consistent control of the GAEC standards.
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Formation of yield and dry matter with genetic resources of opium poppy (Papaver somniferum L.)
Slowiaczek, Lukáš ; Hnilička, František (advisor) ; Jan, Jan (referee)
Diploma thesis with the topic: Formation of yield and dry matter with genetic resources of opium poppy (Papaver somniferum L.) was worked out at the Department of botanics and plant physiology, Faculty of agrobiology, food and natural resources ČZU in Prague. The purpose of this thesis was to determine genotype and ontogenetic differences in amount of yield, production of dry mass, and value of growth-analytic characteristics in certain species of opium poppy. Diploma thesis was based on the fact that most of the studies about opium poppy (Papaver somniferum L.) are focused on the content of alkaloids and other substances present in poppy seeds. Due to this facts, it is necessary to describe the genotypes of poppy plants and their genetic resources from the physiological point of view.
Following species of opium poppy were chosen for the experiment: Akvarel, Albín, Buddha, Florian, Korneuburger Weisser, Lazur, Major, Marianne, Opál, Postomi, Sokol, Tatranský. These species were chosen according to their content of alkaloids, especially morfine very low content, low content, medium content and high content of morfine. All of the tested genotypes are tested as object of study of genetic poppy resources. Seeds were supplied by GB Oseva Pro s.r.o., o.z. VÚO Opava and company Český mák.
Field experiments were established at the research laboratory FAPPZ ČZU in Prague, in Červený Újezd. This location is in Prague-West division, in area of Middle Bohemia. The altitude of this location is 401 metres above the sea level. The size of the field for testing was 2 m2. The experiment was based in 4 repetitions by the method of Latin square. Winter wheat was used as the preceding crop. Opium poppy was planted according to agrotechnical principles of planting.
Content of dry mass in individual plant organs was measured in certain ontogenetic stages of opium poppy (35, 45, 49, 52, 54, 62, 81 BBCH). Size of leaf area was assessed by the image analysis WinDias. Yield of seeds was assessed as well. Growth-analytic characteristics were calculated from the values of wieght of dry mass and size of leaf area.
The results confirmed that the size of plants is influenced by its ontogeny and also by its species. The results also confirm, that the height of plants is not influenced by the content of morfine. Connection between the colour of seeds and height of plant was not confirmed either. Increase in weight of above-ground biomass depending on ontogenetic stage and influence of plant species was confirmed. There are differences in production of yield in species of poppy with different contents of morfine because the average weight of yield in species with very low content of morfine was 112,36 g, in species with low content of morfine 110,41 g, in species with middle content of morfine 12167 g and in species with high content of morfine 123,16 g. It was approved that ontogeny of plants influences the leaf area index (LAI) as it increases until blooming and then it decreases as a result of senescence and falling off the old leaves. Differences in leaf area index were detected among the species of opium poppy, depending on the content of morfine. It was detected that crop growth rate (CGR), relative crop growth rate (Rw) and relative growth rate of assimilation area (RA) are influenced by the ontogeny of plants. It was detected that species with high content of morfine in poppy seeds (Buddha, Postomi, Lazur) and species with white seeds Sokol and Albín have lower yield than species with middle content of morfine.
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Possible solutions to the restoration of overmature forest stands in the Lány game enclosuregame-park
Ambrož, Robin ; Vacek, Stanislav (advisor) ; Igor, Igor (referee)
Possible solutions to the restoration of overmature forest stands in the Lány game enclosure -- this is a problem that generations of foresters in the Křivoklátsko region have been faced with. The restoration has often been postponed; as a result, there has been a remarkable increase in the number of such stands in the game enclosure. Currently, almost a third of the game enclosure is covered by stands, predominantly beech, older than 160 years, and the suggestions on how to restore these stands are by no means unified, not only within the framework of the relevant authorities, but also among the management of the Lány forestry administration. In the past, the disintegration of stands in the highest age class was dealt with by a massive planting of large-sized plants in the whole area of the game enclosure, which has brought and will continue to bring about a remarkable increase in the forest protection costs. The aim of this PhD thesis is to answer the questions concerning the restoration of the local beech stands and to propose a solution that would be efficient in the long term. The basic questions have been phrased as follows: In what condition are the extensive large-sized plant plantings? What is the number of overmature forest stands in the Lány game enclosure and what will their future development be? Are these stands still capable of producing a sufficient number of beech seeds to ensure successful natural regeneration? In what way should we restore these overmature forest stands? How should we protect them from the game damage? It was necessary to find some of the answers within the framework of intermediate scientific tasks; however, the finding of a conceptual solution to the restoration of the game enclosure remained the main goal of this work. To fulfil the goals of this thesis, it was necessary to perform the inventory of large-sized plant plots; it was found out that the total number of individuals planted in the Lány game enclosure until the end of 2011 was 28,994 at 840 plots. The plantings established in 2011 were surveyed as to their vitality and height increment between the years 2011 and 2014. In 2015, a sample was selected on which the condition of the root system was analysed according to the type of a container used for the raising of large-sized plants. It is evident from the results that despite considerable investment in fencing, the large-sized plant plantings are very often damaged by game and have to be repeatedly reinforced. The root system analysis revealed that a significant number of individuals show serious root system deformations. Consequently, the optimization of large-sized plant planting was proposed. The condition of the beech stands at PRP was ascertained with the aid of the FieldMap technology; the stand development prediction was carried out by the growth simulator SIBYLA. The verification of the fertility of the overmature beech stands took place at smaller plots demarcated within PRP. The results show that the occurrence of game eliminates natural regeneration in these stands; thus, it is necessary to find a way which will not be only efficient, but also economical. The fertility verification proved that despite their advanced age, the beech stands preserve their ability to produce seed material, which could be used for regeneration under a shelterwood. Finally, a model regeneration block presenting two possible reproduction methods (with maximum utilization of natural regeneration and accelerated one) was designed on the basis of both the differentiation of the game enclosure and the localization of stands with the highest degree of regeneration urgency.
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