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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
411

Vliv odběrového místa na hygienicky významné ukazatele kvality vody v přírodních koupalištích / The effect of sampling point on hygienically significant water indicators in natural bathing establishment

Zelinková, Myra January 2012 (has links)
In this diploma thesis, I deal with the influence of the sampling site on water quality in natural bathing lakes (Hostivar reservoir, Seberak pond and Vyzlovka pond) in this. I have established that hygienically significant kinds of phytoplankton may differ in terms of water quality especially where there are cyanobacteria constituting water bloom. Surface water bloom may be moved by wind to the lee side of the water body (Microcystis sp.). Aphanizomenon flos-aquae water bloom floating in water column can be affected by wind and by water flow (which may be partly affected by wind as well). With the prevailing fibrous Planktothrix agardhii which does not connstitute water bloom the concentration of chlorophyll-a and cyanobacterial cell abundance in individual sampling sites are similar although the concentration of chlorophyll-a a is about 200 g.l-1 . Microcystis sp. and Scenedesmus sp. survive under eutrophic conditions in competition. From the microbiological perspective, water quality can differ within a single sampling site in places at a distance of less than 100 m. Microbial contamination can be caused by bathers, water birds, farm animals and probably by the removing of microorganisms from sand, mud and sediments on the beach or shore. Rain episodes probably increase the abundance of E.coli...
412

Hodnocení zátěže životního prostředí v ČR pomocí indikátoru Vodní stopa / Environmental assessment of the Czech Republic based on Water Footprint

Žlábková, Jana January 2013 (has links)
This dissertation sets its goal in application of the water footprint indicator, which is a practical and multi-layered indicator of water sources consumption. Of human activities, agriculture presents the most significant demands on water sources consumption. Therefore I have turned my focus to the widely-discussed issue of biofuels production, because the input materials for production of this kind of energy are agricultural crops (in the Czech republic those are: oilseed rape, sugar beet, Indian corn and winter wheat). The calculated results of water footprints of the selected industrial crops (m3 /t) and of water footprints of the heating value units of that crops (m3 /GJ) offer us a concrete notion of energy requirements of water of that chosen industrial crops in the conditions of the Czech republic. Keywords: water footprint indicator, biofuels, oilseed rape, water consumption, biodiesel, bioethanol, evapotranspiration.
413

Inovace systému chlazení točivých elektrických strojů s využitím CFD metod / Innovation of the Cooling System of Rotating Electrical Machines using CFD Methods

Sikora, Michal January 2011 (has links)
This thesis deal with design and implementation of innovative cooling method, intended primarily for medium-power synchronous generators. The main objective of this proposal is to remove the large heat exchanger connected to generator. This heat exchanger unduly increases the space requirements for the machine location. The proposed solution is to use a direct water-cooled stator. It is assumed that the rotor winding will be still cooled by air. Unlike current cooling system, the hot air from the rotor can be cooled in smaller cooler inside the generator. In this work are described methods which can be used for design of water cooling basic parameters, taking required temperatures into account. A small induction motor was selected for practical verification of the proposed cooling concept. This motor was modified into two variants - related to the old cooling of synchronous generators and related to the proposed solution. Both of these variants were measured and compared with each other. Subsequently, CFD models of these two variants were set up. Measured temperatures were used for debugging of models and identification of material properties of components of these machines. The final model of water-cooled variant also makes it possible to simulate the work of motor for higher performance and to determine the overload compared with the old cooling variant. Some knowledge and experience obtained from the small water-cooled induction machine were used in the design of water-cooling for large synchronous generator. In a similar way, CFD models of the old variant of cooling and proposed variant of water- cooling were created. Although these models were not verified by actual measurements on the generators, the results indicated that the application of water-cooling in this type of machine is appropriate and provides many benefits.
414

Tvorba a estimace modelu malé vodní elektrárny v programu PSCAD / Creation and estimation of small hydro power plant model in PSCAD

Razyapova, Aygul Unknown Date (has links)
This thesis focused on creating a model of a small hydropower plant model (SHPP) and a part of the electricity network in the simulation software "PSCAD" (basing on real sources). The model will be specified on the basis of the data obtained from the measurements to correspond with the real equipment.
415

Analýza konstrukce tarifů vodného a stočného ve vztahu ke kritériím efektivnosti udržitelnosti a solidarity / Analysis of the water pricing structures in relation to objectives efficiency, sustainability and equity

Romášková, Adéla January 2009 (has links)
Expenditures on water are the significant part of aggregate household spending and their height depends on a design of tariff for public water supply and sewage services among others. This diploma work describes different water pricing structures used in foreign and shows how each structure can be used to achieve objectives -- efficiency, sustainability and equity. The Czech system of price making is referred to as efficient but unfair because it doesn't take in consideration households with low incomes. Because of the continual rise in prices affected by fulfilment standard of the European Union are expected future problems with social acceptability of water prices. The goal of the work is to find possible modification of regulation which might solve this problem.
416

Analýza srážko-odtokových procesů a erozních charakteristik vybraného povodí při různém uspořádání krajiny

VANČUROVÁ, Lenka January 2019 (has links)
The diploma thesis focuses on the analysis of rainfall-runoff processes and erosion characteristics of selected catchment in different landscape management. This analysis was solved at the Lukavecký brook catchment, which is located in the Pelhřimov district in Vysočina region. The theoretical part of the thesis describes the rainfall-runoff process and then focuses more on individual processes. It also characterizes water erosion, its consequences, forms and erosion control. At the end of the theoretical part are described methods of calculation of water runoff and water erosion. The practical part describes the catchment of the Lukavecký brook, its characteristics of natural conditions and the threat of water erosion. Then there is a procedure for processing of bases and data in the program ArcGIS. Subsequently, it includes an assessment of the different measures and changes in the type of land to drain water from the catchment and erosion threat.
417

Vodní režim blatkových borů na Třeboňsku a vodní provoz jejich dominant / Vodní režim blatkových borů na Třeboňsku a vodní provoz jejich dominant

Kučerová, Andrea January 2011 (has links)
The thesis was intended to fill the information gap in the ecohydrology of the Pinus rotundata dominated peatbogs in the Třeboň Basin Biosphere Reserve, Czech Republic by studying various aspects of their water régime (i.e., transpiration of the dominant tree species, soil water chemistry, retention ability). The study is based on regular monitoring of the water table, water discharge, soil water chemistry and precipitation (during 1995-2000, study sites Červené blato and Žofinka peatbogs). Additionally, the transpiration of adult Pinus rotundata trees was measured in the field during 1999-2000 at the experimental plot in the Červené blato peatbog (330 ha, 465-475 m a.s.l.). Nowadays, the Pinus rotundata-dominated peatbogs represent almost natural (peaty) forests inside of otherwise human-made forest plantations. Long-term vegetation changes after natural disturbances such as windstorms, insect infestation and fire are only occasionally reported for the central European natural forests. Therefore the evaluation of vegetation changes after disturbances, typical of boreal forests, and their impact on peatbog hydrology has also been included in this thesis (study site Žofinka peatbog, 130 ha, 470-475 m a.s.l.). Transpiration of the central European endemic tree species, Pinus rotundata Link, was...
418

Detekce a monitoring potenciálně toxických sinicových lipopeptidů

BÁRTOVÁ, Marie January 2019 (has links)
The aim of this study was to design and optimize new PCR primers for detection of potential cyanobacterial producers of cytotoxic lipopeptides puwainaphycins and minutissamides in environmental samples. Samples from two distinct localities were tested, as suggested based on preliminary data. The first set of samples consisted of cyanobacterial soil biofilms from sheep pastures affected by Alveld illness in Norway. The other one contained samples of planktic cyanobacaterial blooms from Protected Landscape Area Třeboň and its vicinity. Three different approaches were used for evaluation of the presence of cyanobacterial lipopeptide producers: microscopy, PCR with the designed primeres, and liquid chromatography-mass spectrometry analysis. Results of this study confirmed the specificity of the newly designed PCR primers. The presence of producers of puwainaphycins/minutissamides was proven at both tested localities.
419

Trénink a příprava plavců vodní záchranné služby / Training and preparation of swimmers Water Rescue

Marešová, Anna January 2018 (has links)
This thesis looks into a preparation and training of lifeguards during one year training cycle. The objective of this thesis is monitoring (tracking) changes of functional indicators (heart rate) over the period of one year training for lifeguards. My thesis is divided into several parts. Theoretical part is mapping history of lifeguarding and origins of Lifesaving sport. It is focused on disciplines of this sport, specifics of the training and selected functional indicators. The practical part is divided on survey and reflexion (result) part. The survey is recording changes of heart rate in selected phases of a year training cycle. The reflection part is processing results. During a practical part have been used methods of observation, questioning, testing, statistics- collecting and analysing data. KEYWORDS  Lifeguard service  Swimming  Lifesaving sport  Year training cycle  heart rate  sport tester
420

Vyhodnocení efektivnosti investic obnovitelných zdrojů energie na příkladu malých vodních elektráren / Evaluation of Investment Effectiveness on the Field of Renewable Sources by the Examples of Small Hydro Plants

Pavlíčková, Eva January 2011 (has links)
Thesis deals with the use of renewable sources of energy focused on water energy, especially small hydropower plants in Czech Republic. It should clarify the legal and technical framework for energy production in small hydro power plants, types of aid and the amount for the operator. Case studies describe the construction and reconstruction of small hydroelectric power plants which are dependant on the amount of feed-in tariffs and try to find out the economic efficiency according to the selected methods of investment appraisal.

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