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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.
41

Stanovení záplavového území na řece Kyjovce v km 71 až km 74 / Determination of floodplain in Kyjovka river at km 71 to km 74

Kašpar, Tomáš January 2017 (has links)
The diploma thesis discusses the current status of watercourse Kyjovka and a proposal for appropriate protection measures of the territory. The selected section starts at river-km 71,338 and ends at river-km 74,443. The selected part of the watercourse runs through the town of Koryčany. This thesis examines the selected section of Kyjovka split into two subsections. That allows for detailed presentation of several proposed appropriate measures to be applied at critical spots in the selected subsections. The calculation of the watercourse model and its capacity with the water level progresses for selected N(y.o.) flow rates were processed in HEC-RAS5.0.1. program. Proposed flood protection measures are incorporated in the drawings.
42

Vliv orientace přítoku na charakteristiky přepadu přes širokou korunu / Influence of inflow orientation on overflow characteristics over broad-crest

Major, Jakub Unknown Date (has links)
Weirs belong to the basic water structures mainly creating vertical contraction of stream against the flumes, which creating mainly horizontal contraction of stream. In the case of the flow over weir usually occurs change from subcritical flow over critical with critical depth to supercritical flow, therefore overflow. Weirs with rectangular control section are described rectangular longitudinal and transverse profile and horizontal crest. Can be distinguish three basic inflow directions to weir. The first is frontal inflow, which is the most frequent in practice. The second is lateral inflow used in distribution and consumption objects. The third is lower inflow used as laboratory weirs, weirs with deeply submerged wall, etc. In terms of knowledge of influence listed directions of inflows, currently are not sufficiently researched the cases of frontal inflow with side contraction and lower inflow on all types of weirs. Due to extent of the issue, labour is focused only on frontal inflow over broad-crested weir with side contraction and lower inflow over broad-crested weir without side contraction. The goal of the labour was to summarize the current knowledge of the flow over broad-crested weir with side contraction and lower inflow over broad-crested weir without side contraction, describe the character of the flow at the overflow and on the basis of it determine recommendations for measurement and calculation of discharge. Further to define unexplored area, specify methods of solution and verify own measurements. The research dealt with application and optimal numerical model setting for to solve the problem.
43

Key Influences on Hydraulic Efficiency in Treatment Wetlands

Wahl, Mark D. January 2013 (has links)
No description available.
44

Wastewater treatment in constructed wetlands : Effects of vegetation, hydraulics and data analysis methods

Bodin, Hristina January 2013 (has links)
Degradation of water resources has become one of the most pressing global concerns currently facing mankind. Constructed Wetlands (CWs) represent a concept to combat deterioration of water resources by acting as buffers between wastewater and receiving water bodies. Still, constructing wetlands for the sole purpose of wastewater treatment is a challenging task. To contribute to this research area, the fundamental question raised in this doctorate thesis was: how do factors such as vegetation and residing water movements (hydraulics) influence wastewater treatment in CWs? Also, effects of different data analysis methods for results of CW hydraulics and wastewater treatment were investigated. Research was focused on  phosphorus (P), ammonium-nitrogen (NH4+-N) and solids (TSS) in wastewater and o n P in macrophyte biomass. Studies were performed in pilot-scale free water surface (FWS) CW systems in Kenya (Chemelil) and Sweden (Halmstad) and as computer simulations. Results from the Chemelil CWs demonstrated that meeting effluent concentration standards simultaneously for all water quality parameters in one CW was difficult. Vegetation harvest, and thus nutrient uptake by young growing macrophytes, was important for maintaining low effluents of NH4+-N and P, especially during dry seasons. On the other hand, mature and dense vegetation growing for at least 4 months secured meeting TSS standards. Phosphorus in above-ground green biomass accounted for almost 1/3 of the total P mass removal, demonstrating high potential for P removal through macrophyte harvest in CWs. Also, results suggested that harvest should be species-specific to achieve high P removal by macrophytes and overall acceptable wastewater treatment in CWs. Still, different methods to estimate evapotranspiration (ET) from the Chemelil CWs showed that water balance calculations greatly impacted estimations of wastewater treatment results. Hydraulic tracer studies performed in the Chemelil and Halmstad CWs showed that mature and dense emergent vegetation in CWs could reduce effective treatment volumes (e-values), which emphasized the importance of regulating this type of vegetation. Also, it was shown that hydraulic tracer studies with lithium chloride performed in CWs with dense emergent vegetation had problems with low tracer recoveries. This problem could be reduced by promoting the distribution of incoming tracer solution into the CW using a barrier near the CW inlet pipe. Computer simulation results showed that the choice of tracer data analysis method greatly influenced quantifications of CW hydraulics and pollutant removal. The e-value could be 50% higher and the pollutant removal 13% higher depending upon used method. Moreover, unrealistic evalues (above 100%) in published literature could to some extent be explained by tracer data analysis method. Hence, to obtain more reliable hydraulic data and wastewater treatment results from CWs, more attention should be paid to the choice of tracer data analysis method. / Konstruerade våtmarker representerar ett koncept för möjligheten att nå en hållbar vattenresurshantering genom att agera som ”filter” mellan föroreningskälla och viktiga vattenresurser såsom sjöar och hav. Mycket kunskap saknas däremot om hur man konstruerar våtmarker med en optimal och pålitlig vattenreningskapacitet. Den här avhandlingen undersöker därför hur vegetation och vattnets väg genom våtmarken (hydrauliken) påverkar avloppsvattenrening i våtmarker. Dessutom undersöktes hur valet av dataanalysmetod av insamlad data påverkar resultaten. Studier genomfördes i Kenya och Sverige i experimentvåtmarker (ca. 40-60 m2) och inkluderadedatainsamling av vattenkvalité, hydraulik (spårämnesexperiment) samt biomassa och fosfor i biomassan av två olika våtmarksväxter. Dessutom genomfördes datorsimuleringar. Resultaten från Kenya visade att växtskörd och efterföljande näringsupptag av nyskördade växter var viktig för att uppnå låga utgående koncentrationer av fosfor och ammonium i en tropisk våtmark, speciellt under torrsäsongen. Däremot var en välutvecklad och tät vegetation viktig för reningen av partiklar. Fosfor i grön växtbiomassa representerade cirka 1/3 av våtmarkernas totala fosforrening, vilket påvisade potentialen i att genom skörd ta bort fosfor från avloppsvatten m.h.a. konstruerade våtmarker. Resultaten pekade också på att skörden bör vara art-specifik för att uppnå en hög fosforrening och generellt bra vattenreningsresultat. Dock visade olika beräkningsmetoder att vattenbalansen i en tropisk våtmark markant kan påverka vattenreningsresultaten. Resultaten från spårämnesexperimenten demonstrerade att den effektiva våtmarksvolymen för vattenrening blev mindre vid hög täthet av övervattensväxter. Detta pekade på att regelbunden växtskörd var viktig för att uppnå god vattenrening i våtmarker. Experiment med spårämnet litium visade att man kan få felaktiga resultat p.g.a. att en del spårämne fasthålls på botten i våtmarken om denna har mycket övervattensväxter. Därför bör spridningen av spårämnet i sådana våtmarker underlättas m.h.a. en spridningsbarriär nära inloppsröret. Simuleringar visade också att valet av dataanalysmetod av spårämnesdata starkt kan påverka resultaten och därmed också vår tolkning av en våtmarks hydraulik och reningskapacitet. Den effektiva volymen kunde vara 50% högre och reningseffekten 13% högre beroende på vilken metod som användes. Likaså kan valet av dataanalysmetod ha bidragit till överskattade och orealistiska effektiva volymer (över 100%) i artiklar publicerade de senaste 25 åren. Genom att fokusera mer på valet av dataanalysmetod och t.ex. jämföra resultaten från två olika metoder kan man minimera risken för bristfälliga resultat och därmed felaktiga slutsatser om en våtmarks vattenreningskapacitet.
45

Politika vody / Water Politics

Dvořáková, Dana Unknown Date (has links)
The work is aimed at familiarizing the audience with the problems of water in the Czech Republic and its distribution within the landscape. However, its character, which approaches to documentary work, doesn´t explicitly describe the problem, but rather attempts to visualize it and give the viewer space for his own imagination. The work draws in contrast the examples of fine functional interventions in the landscape with examples of monstrous concrete structures - dams. It points to problematic places and tries to convey to the viewer the current issue not only in the chosen location. The main thing is the lyrical performance, which evokes not only a video but also the sound part and the narrative that explains the whole problem. The video is not purely informative, its specificity is also focused on the enjoyment of the viewer. He plays with documentary techniques but does not use them as a priority. The shots are deliberately chosen so that the concrete buildings look monumental and have their seriousness. The background of the shots also shows the time of their creation. This element is supposed to be critical and is supposed to be opposed to studies that use old plans to build new water reservoirs that do not give space for a more efficient solution. The work also touches on the overproduction and issues of today's modern agriculture.
46

Mikroklima bazénových hal / Indoor environment of pool halls

Halla, Ondřej January 2019 (has links)
The diploma thesis deals with the problems of the indoor environment of swimming pool halls. Firstly, it describes issues and principles of designing HVAC system in the areas with high humidity production. Thesis then focuses on various approaches to calculations of evaporation from the water surface and different possibilities of dehumidification including different types of HVAC units. This knowledge was applied to the design of HVAC system for particular assigned building, for which are proposed two different solutions. Thesis includes experimental part, its aim is to analyse one specific critical part of the hall. Based on local surveying and long-term measurements a few possibilities of improvement are suggested.
47

Quantification of the Effect of Bridge Pier Encasement on Headwater Elevation Using HEC-RAS

Sharma Subedi, Abhijit 21 August 2017 (has links)
No description available.
48

Zakládání na objemově nestálých zeminách / Foundations in Volume Unstable Soils

Legut, Dana Unknown Date (has links)
This dissertation is concerned with the foundations in volume unstable soils and objects disorders which are related to this. The thesis was focused on the study of clay and loess soils which are abundant in the geological profile of the Czech Republic. First, the formation of the two groups of soils is introduced, then their properties are examined and finally the influence of vegetation on the former type and the influence of collapsibility in the latter type are investigated. The conclusion is, in fact, a recommendation on the design of structures so that the system of clay / structure is not damaged and that structures are not subject to renovations. Several instance of problems with structures are discussed which were subject to structural repairs employing both a civil and geotechnical engineers.

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