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Experimental Investigation of The Flow Pattern Behind Cylinder
Vítkovičová, R. ; Skála, Vladislav ; Čížek, J.
Investigation of the flow behind bluff bodies, especially for cylinder, is one of the highly topical research topics in the fluid mechanics. Nevertheless, mainly because of its complexity, this topic is still an open problem. This article discusses the running project at the Czech Technical University in Prague, Faculty of Mechanical Engineering and it deal with the implementation of a methodology for measuring the cylinder wake in a wind tunnel and also recapitulates the partial results obtained measurements.
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Design of Landscape Management of Horní Počernice
Barešová, Terezie ; Syrovátka, Oldřich (advisor) ; Novotná, Eliška (referee)
This bachelor thesis deals with the assessment of the current landscape management in Horní Počernice and the design of ecological measures, which can be used as a basis for comprehensive land changes of Horní Počernice. The theoretical part defines basic terms of landscaping and landscape ecology. The practical part describes the selected area including processing of ecological characteristics. Ecological measures of landscape are designed to improve the quality of life in Horní Počernice. A research was made to investigate the attitude of residents to the scenic countryside in connection with the expansion of buildings at the expense of vegetation. The conclusion contains an evaluation of the research.
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International involvement in the peacebuilding process on Sri Lanka
Mojžíš, Michal ; Havlová, Radka (advisor) ; Burešová, Jana (referee)
The final months of Sri Lankan civil war, the 26 year military campaign between the Government of Sri Lanka and the insurgent separatist organization Liberation Tigers of Tamil Eelam, are marked by allegations of war crimes committed by both parties of the conflict, including attacks on civilians, summary executions of prisoners, enforced disappearances, restrictions on humanitarian assistance and recruitment of children. Since the attempts to put the Sri Lankan issue on the agenda of the United Nations Security Council failed on the unwillingness of China and Russia, the UN bodies in Geneva have taken a leading role in promoting the peacebuilding process on the island. The thesis aims to analyse the impact of the Geneva-based human rights bodies, in particular of the United Nations Human Rights Council, on the process of reconciliation in Sri Lanka, for which is crucial that the alleged violations of human rights in the last months of the civil war would be properly investigated and that the perpetrators would be held accountable. In order to put the activity of the UN Human Rights Council into broader context, the paper will examine the political development in Sri Lanka since the end of the civil war in 2009 as well as the failed efforts of Sri Lankan governments to launch the process of reconciliation.
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HYDROGENATION PROPERTIES OF BALL-MILLED Mg-Ti-C-Zr COMPOSITE
Král, Lubomír ; Čermák, Jiří ; Roupcová, Pavla
The hydrogen storage properties of ball-milled Mg-Ti-Zr-C composite (1.8 wt.% Ti, 1.9 wt.% Zr and 0.2 wt.% C) were investigated. It has been previously shown, that the addition of Ti, Zr and C improved its storage properties. This beneficial effect of additives upon hydrogen storage properties can be explained by catalysis by the particles rich in Ti or Zr located on the surface of Mg grains. They provide effective pathways for the hydrogen diffusion into the MgH2. The morphological and microstructural characteristics were investigated by scanning electron microscopy and by X-ray diffraction. The hydrogen sorption was measured by Sieverts method using Setaram PCT-Pro device. In this paper, sorption behaviour of the composite after ball-milling and after aging on the air was compared. The ball-milled composite adsorbed 3.5 wt.% H2 within 10 min at 623 K. However, hydrogen storage capacity of the composite aged on the air for 7 months remarkably decreased: The aged composite adsorbed within 10 min only 2 wt.% H2 at 623 K and the sorption capacity decreased from 4.7 wt.% H2 to 2.1 wt.% H2.
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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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PM2.5 Chemical Composition at the Rural Background Site Košetice.
Schwarz, Jaroslav ; Cusack, Michael ; Karban, Jindřich ; Chalupníčková, E. ; Havránek, Vladimír ; Smolík, Jiří ; Ždímal, Vladimír
Measurements of atmospheric aerosols at rural background areas are important because they are not influenced by the urban emissions, and are therefore better suited to investigate the influence of long-range transport and trends in concentrations of individual pollutants. Summary of the measurements of total concentration and the concentration of PM10 and PM2.5 components was carried out in the works Putaud et al. (2004, 2010). Although the later work included the measurement of more than 60 stations across Europe, the post-communist countries contained data on PM2.5 from only four locations (Prague, Debrecen, Hungary, and two rural locations). Although Košetice place where this study was made, is also discussed there, it was for only PM10 and total carbon (TC). Therefore, the aim of this study is to fill this information gap, and provide additional information regarding the PM2.5 fraction and composition at the Central European background station Košetice.
Fulltext: content.csg -  PDF
Plný tet: SKMBT_C22016110313110 - PDF
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Age management
Jirásková, Barbora ; Dvořák, Marek (advisor)
This thesis processes the concept of the human resources management with respect to the age structure of employees in the intentions of the Czech Republic. In the theoretical part, there is outlined the history of the application of the principle of age management, focusing on current demographic trends, forecasts of population age structure, the aging workforce and the need to preserve the ability to work into old age. Points to the need to adapt corporate strategy, personnel management trend of an aging population. It presents ideas for the main underlying programs and legislative measures which form the basis of the latest concepts and strategic plans in the Czech Republic and Europe. The empirical part deals with a specific level of allowance organization established by TSU and two sub investigation. The first is a case study of age management staff. The resulting data are confronted with the results of a survey among employees of the organization. The second investigation are interviews with members of management and employees of the HR department on the issue of the introduction of age management, their awareness of the concept of age management, the question of age discrimination, the issue of maintaining the continuity of knowledge in the organization and their views on these topics. The outcome of this survey indicates a willingness and readiness of the organization has already received age management principles adhere to and develop further.
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Antioxidant, anti-proliferative and immunomodulatory effect of fruits, vegetables and mushrooms in vitro
Doskočil, Ivo ; Havlík, Jaroslav (advisor) ; Orsák, Matyáš (referee)
Recently there has been an increasing interest in discovering of new species of plants and mushrooms which have antioxidant or anti proliferative activity. The interest is caused by the fact that these species have medicinal and food utilization. These properties of plants and mushrooms can be used when dealing with many diseases which may be connected with oxidative stress (inflammatory bowel disease, cardiovascular disease, hypertension, and tumour disease, etc.).
The thesis propounds characteristics of in vitro antioxidant and anti proliferative activity of 19 types of juices and 28 methanol extracts of fruits and vegetables, which are common parts of a diet. In the thesis there are also characteristics of 13 ethanol extracts of edible mushrooms of the order of Polypore (Popyporales). Antioxidant activity was quantifie by 2, 2 diphenyl 1 picrylhydrazyl (DPPH), oxygen radical absorbance capacity (ORAC), and inhibition of nitric oxide (NO) production. Cytotoxicity was measured by MTT (3 (4,5 dimethylthiazol 2 yl) 2,5 diphenyltetrazolium bromide. Immunomodulatory activity was determined by an assay of phagocytic activity of human neutrophil granulocytes. Further a total phenolic content (TPC) and total beta glucan content were investigated; these are considered to be the potentially active constituents participating in mentioned activities.
From the obtained results it is evident that juices (TPC = 1603.2 mg GAE/L; ORAC = 438.5 umol TE/g)
and a bilberry (Vaccinium myrtillus) fruit extract (ORAC 836.6 umol TE/g; DPPH = 404.6 umol TE/g) showed
the highest antioxidant activity of all tested samples of fruits and vegetables. Capsicum (Capsicum L.)
juices (TPC = 642.1 mg GAE/L; ORAC = 127.9 umol TE/g) and a radish (Raphanus sativus L.) extract
(ORAC 724.5 umol TE/g; DPPH = 52.2 umol TE/g) also proved to have the high values of antioxidant activity. From the tested fruits and vegetables the following inhibited to produce a nitric oxide: onion (Allium cepa L) juices (lowered the NO production by 57%), tangerine juices (Citrus reticulata Blanco)(by 52%), broccoli (Brassica oleracea var. botrytis italic) extract (by 21%), and orange (Citrus sinensis Pers.) extract (by 10%). Concerning edible
mushrooms, Lentinus tigrinus (Bull.) Fr. (TPC = 216.2 umol GAE/g of extract), Ganoderma lucidum (Curtis) P. Kras (TPC = 257.9 umol GAE/g of extract), and Royoporus badius (Pers.) A.B. De (TPC = 257.8 umol GAE/g of extract) presented the highest phenolic content. Sparassis crispa (Wulfen) Fr. (117.4 mg/g of extract) had the highest content of beta glucan. Substantial effect on phagocytic activity of granulocytes was noticed in connection with Neolentinus lepideus (Fr.) Redhead & Ginns, Polyporus squamosus (Huds.) Fr., and S. crispa. In connection with the latter of mentioned mushrooms, a moderate inhibitory effect towards HT 29 human colorectal adenocarcinoma cell line
(IC50 = 107 ug/ml of extract) was noticed.
The results indicate that the tested plants and mushrooms can be beneficial when reducing the negative effects of oxidative stress. The oxidative stress has been recognized as a contributing factor to a whole range of diseases and the reduction of the oxidative stress may lead to the decrease in the possibility of the diseases´ progression. The results show the possible favourable effects on the human health. When evaluating the results, the following fact should be taken into consideration; the in vitro tests and screenings are considered to be the first phase of systematic research of the effects and serve for the choice of respondents for further detailed studies.
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Total contents and speciation of arsenic and selenium in plants growing in soils with different physico-chemical properties
Tremlová, Jana ; Száková, Jiřina (advisor) ; Vymazal, Jan (referee)
This dissertation thesis deals with uptake, accumulation and transformation of arsenic and selenium in plants growing on soils with different chemico-physical soil properties. The contents of arsenic were investigated in 99 wild plant species, coming from 27 different families and 6 different vegetables growing in arsenic contaminated soils. The results suggest that there are species-specific mechanisms which protects certain plants from the excessive uptake of arsenic from the soil. On the other hand, there are plants using a strategy of accumulation, which theoretically may increase the risk of arsenic entry into the food chain, whether through grazing cattle and wildlife or through consumption of vegetables growing on arsenic contaminated soils. The most prevalent arsenic compounds are AsV and AsIII. Other arsenic compounds occure as minor species. An important finding was detection of arsenobetaine in Plantago lanceolata L. and Carex praecox Schreb ..
The contents of selenium were examined in 73 species of wild plants, coming from 29 different families. The results suggest that naturally low levels of selenium in the soil of selected locations along with a low capability of selenium uptake via collected plant species lead to the low content of selenium in plant biomass which may contribute to selenium deficient throughout the food chain. Foliar application of selenate on wild plant communities and on some types of vegetables in our case Brassica oleracea var. italica can have a positive impact on increasing the selenium content in the aboveground biomass of these plants and by extension, increase the selenium content in the human diet. Dominant selenium compounds in the aboveground biomass of the analyzed plants were SeVI and selenomethionine, with variable proportion of other commonly occurring organic selenium compounds, which is mainly affected by plant species.
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