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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.
51

Nákladní lodní doprava na Labi v ČR / Cargo inland waterway transport on the Elbe river in the Czech republic

Chrustová, Kateřina January 2008 (has links)
The thesis attends to cargo inland waterway transport on the river Elbe in the Czech republic. The target is to analyse its progress, function and place in national and international transport. The thesis shows actual problems that occur in inland waterway transport. The main problem is the bottleneck at the Czech - German border which should be solved by building-up of the weir in Děčín. But this is not acceptable for environmentalists. The target as well is to quote reasons why to built-up the weir which is important for the development of inland waterway transport.
52

Determinação da concentração de metais em cultivares produzidos nos perímetros irrigados Jacarecica I e açude Macela localizados na cidade de Itabaiana-SE / DETERMINATION OF THE CONCENTRATION OF METALS PRODUCED IN CULTIVARS IN IRRIGATED AREAS JACARECICA IE WEIR MACELA LOCATED IN THE CITY OF YOURSELF ITABAIANA.

Santos, Marcos Santiago 28 February 2012 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / The technological development and population growth have led man to increasingly exploit the natural resources of Earth Planet to meet their own needs, which has caused a major concern as the environment, since this operation has not been done so rational, but a predatory way. With population growth, it´s necessary to increase food production, but the area of cropland in the world does not grow as fast as population. Thus, increase of food production becomes possible with intensification of agriculture in the areas available, through the use of inputs such as fertilizers, agrochemicals, fossil energy and irrigation techniques. Currently, one of the most serious problems affecting the environment from chemical pollution is organic or inorganic in nature, resulting from residential and industrial discharges. All forms of life are affected by the presence of heavy metals, ones more and ones less, depending on the dose and chemical form. Thus, the major concern with these elements is related to its bioaccumulation by aquatic flora and fauna that ultimately reach the man, producing lethal and sublethal effects arising from metabolic disorders. The knowledge about the interactions between plants and heavy metals is very important, not only the safety of the environment, but also to reduce the risks associated with the introduction of these elements in the food chain. This study determined the concentration of metals in cultivars produced in irrigated areas Jacarecica I and Macela Dam in Itabaiana-SE. The quantification of metals Zn, Cu, Ni, Cr, Pb, Mn, Fe, Na, K, Mg and Ca was made by Atomic Absorption Spectrometry. The results of the analyzes in vegetables were expressed as a function of wet mass. Of the metals analyzed, compared with the levels established by the Agency for Sanitary Surveillance (ANVISA), all samples of vegetables analyzed had levels below the limit of tolerance. The results for the soil samples collected in each irrigated vegetable plots were compared with the "Guiding Values for Soils and Groundwater in the State of Sao Paulo" the BOARD DECISION No. 195-2005 - E (CETESB, 2005), and all soil samples analyzed had levels below these values. The data set obtained with the mean concentrations of vegetables and soil samples was subjected to exploratory data techniques, principal component analysis (PCA) and hierarchical cluster analysis (HCA) promoting the separation of vegetables according to their type , showing that there is a predominance in metal concentrations in vegetables of roots, while the soil was separated according with the perimeter and the elements in macro and micronutrientes. The computational program Statistica 6.0 was used for processing the data and generation of graphics . The accuracy and precision of the analytical method for samples of vegetables and soils were determined by analyzing, in triplicate, the certified reference material Peach leaf (NIST 1547) and sediment (NCS DC 75304), respectively. The results showed that at the present time, there is no contamination in irrigated areas, for the studied metals. / O desenvolvimento tecnológico e o crescimento populacional têm levado o homem a explorar cada vez mais os recursos naturais do planeta Terra para satisfação de suas necessidades, o que vem causando uma maior preocupação com o meio ambiente, visto que, essa exploração não tem sido feita de forma racional, mas de maneira predatória. Com o crescimento populacional, é necessário incrementar a produção de alimentos, porém a área de terras cultiváveis no mundo não cresce na mesma velocidade que a população. Dessa forma, aumentar da produção de alimentos torna-se possível com intensificação da agricultura nas áreas disponíveis, através da utilização de insumos como fertilizantes, agroquímicos, energia fóssil e técnicas de irrigação. Atualmente, um dos problemas mais sérios que afetam o meio ambiente é a poluição química de natureza orgânica ou inorgânica, decorrente dos despejos residenciais e industriais. Todas as formas de vida são afetadas pela presença de metais pesados, umas mais e outras menos, dependendo da dose e da forma química. Assim sendo, a maior preocupação com estes elementos está relacionada à sua bioacumulação pela flora e fauna aquáticas que acaba por atingir o homem, produzindo efeitos subletais e letais, decorrentes de disfunções metabólicas. O conhecimento sobre as interações entre as plantas e os metais pesados é muito importante, não só à segurança do meio ambiente, mas também para reduzir os riscos associados com a introdução desses elementos na cadeia alimentar. Este trabalho determinou a concentração de metais em cultivares produzidos nos perímetros irrigados Jacarecica I e Açude Macela, localizados na cidade de Itabaiana-SE. A quantificação dos metais Zn, Cu, Ni, Cr, Pb, Mn, Fe, Na, K, Mg e Ca foi feita por Espectrometria de Absorção Atômica. Os resultados das análises realizadas em hortaliças foram expressos em função da massa úmida. Dos metais analisados, em comparação com os níveis estabelecidos pela Agência de Vigilância Sanitária (ANVISA), todas as amostras de hortaliças analisadas apresentaram níveis abaixo do limite máximo de tolerância. Os resultados referentes às amostras de solo coletadas nas hortas em cada perímetro irrigado foram comparados com os Valores Orientadores para Solos e Águas Subterrâneas no Estado de São Paulo da DECISÃO DE DIRETORIA Nº 195-2005- E (CETESB, 2005), sendo que todas as amostras de solo analisadas apresentaram níveis abaixo desses valores. O conjunto de dados obtidos com as médias das concentrações das amostras de hortaliças e solos foi submetido a técnicas exploratórias de dados, análise de componentes principais (PCA) e análise de agrupamento hierárquico (HCA), promovendo a separação das hortaliças de acordo com o seu tipo, mostrando que há uma predominância na concentração de metais nas hortaliças de raízes, enquanto que o solo foi separado de acordo com o perímetro e os elementos em macro e micronutrientes. O programa computacional Statistica 6.0 foi utilizado para o processamento dos dados e geração dos gráficos. A exatidão e a precisão do método analítico para as amostras de hortaliças e solos foram determinadas pela análise, em triplicatas, do material de referência certificado de folha de pêssego (NIST 1547) e sedimento (NCS DC 75304), respectivamente. Os resultados obtidos mostraram que até o presente momento, não há contaminação nos perímetros irrigados, para os metais estudados.
53

Analýza proudových poměrů v okolí nové vodní elektrárny / Hydraulic analysis in the surrounding of hydro power plant

Lorenc, Václav January 2018 (has links)
The diploma thesis deals with analysis of flow ratios at the hydraulic plant Klecany – Roztoky, located in the region of Střední Čechy at Vltava river (km 37,08). At this site 3D streaming of superficial water was simulated aiming to evaluate the influence of potencial construction of the new hydroelectric power plant Klecany II on existing Klecany I. Using all of the base documentation available, 3D models of current and planned conditions were created to serve as base for calculation in FLOW 3D. The first part of the thesis describes, how the planned construction of the new hydroelectric power plant Klecany II could influence the current fairway at the inlet 400 m3/s. The second part analyses shape of planned flow hydroelectric power plant Klecany II for flow Q90d, equal to 180 m3/s. All of the results are presented in intelligible charts and images.
54

Studie rybích přechodů na Bečvě / Study of fish-passing facility on the weirs on Bečva river

Chovancová, Kateřina January 2013 (has links)
This master's thesis consists of three main parts. The first section describes some types of fish crossings and basic information of their design. There is also marginally described program HEC-RAS. The second part is about the Zuberská weir and Osek stage. I review here fish ladders according to the original drawings in the HEC-RAS and suggest possible options to address these passable fish crossings for the fish crew. The last section is devoted to Mikulenkov weir where the fish crossing has been completely removed. Here I propose a new fish ramp according to modern knowledge and applicable standards. I also review the proposed fish ramp in the HEC-RAS program in order to verify the hydraulic characteristics.
55

Zhodnocení kapacity nízkých přelivů při převádění extrémních průtoků / Capacity evaluation of the extremely hydraulically loaded low weirs

Jobánek, Stanislav January 2014 (has links)
The thesis deals with values of overfall discharge coefficients for commonly used types of low weirs. Comparison of their values with values based on established procedures. Determination of low weir capacity at free and submerged overfall.
56

Environmentally Friendly and Sustainable Stream Stability in the Vicinity of Bridges

Cope, Evan David 12 March 2014 (has links) (PDF)
This report was sponsored by the Utah Department of Transportation (UDOT) to determine if stream restoration structures could be used as scour countermeasures near state highways and bridges. Scour countermeasures that are effective in preventing erosion exist but that are not so friendly for aquatic organisms. UDOT is interested in finding a countermeasure that is both effective in preventing erosion while not harming aquatic organisms. Stream restoration structures are friendly for aquatic organisms but are prone to failure when flows exceed the design levels. David Rosgen has developed restoration structures that are friendly for aquatic organisms and that have provided streambank protection. These structures are the J-Hook vane, Cross-Vane and W-Weir. Based research done in this report, Cross-Vanes and W-Weirs are best suited to protect bridges because they will protect both sides of a stream bank. For these restoration structures to be reliable at higher flows and shear stresses experienced at bridges, they must follow the design criteria specified in this report. One of the most important design requirements is that the structures designed by David Rosgen have an attached floodplain where the structure meets the streambank. The floodplain disperses the energy of the flow, reducing shear stress. In the vicinity of some bridges, a floodplain cannot be implemented. In such cases, culverts can be installed at the floodplain level, that pass under the bridge to help reduce shear stresses, mimicking a floodplain. Cross-Vanes and W-Weirs can be used to protect bridges and other infrastructure. Based on modeling and comparing restoration structures to a labyrinth weir, they still have an impact on higher flows. At higher than design flows, such as experienced at bridges, the structures help to reduce shear stresses. To further investigate their use as a scour countermeasure near bridges, it is recommended that a structure be installed near a bridge following this report's design criteria. This will be determined depending on available funding.
57

Konstrukční návrh výukového hydraulického okruhu / Construction design of instructional hydraulic laboratory circuit

Havlát, Michal January 2015 (has links)
It is suitable to add practical illustrations of hydraulic tasks during teaching hydraulics and hydrology. These practical illustrations can be realized by mobile hydraulic circuit which is situated in the auditorium. This thesis is focused on constructional and project solution of the circuit which consists of a compensatory tank with sufficient capacity, pump aggregate and hydraulic measure flume. The construction of hydraulic flume must enable quick, simple and safety installation of a scaled down models of a hydro technical structures. The main requirements of a mobile teaching circuit are clearness of practical hydraulic illustrations, compact dimensions, comparatively low weight, mobility and simple control and manipulation. This diploma thesis also includes design of a scaled down models of a hydro technical structures, especially set of plate weirs, bed-crested weir, ogee-crested weir, culvert, Venturi flume, sluice and radial gate, pier and roughened bed. The hydraulic circuit drawing part also includes instrument carrier with level gauge. This diploma thesis includes theoretical text part, technical report of designed objects, hydraulic calculations and drawing part.
58

Posouzení vlivu nestandardních přítokových proudových poměrů na Q/h charakteristiku ostrohranného přelivu s obdélníkovým výřezem / Assessment effects substandard tributaries flowing a proportion on Q/h characteristics thin-plate weir with a rectangular cutout

Šmidrkalová, Nina January 2012 (has links)
This master´s thesis deals with the problem of measuring flow, especially using the method of Q/H characteristics. It describes the thin-plate weir and mentions specific channels. The master´s thesis suggests options of monitoring flow capacity in fixed proffiles with free surface. The master´s thesis also includes an experiment, which is focused on simulation of substandard tributary flowing proportions before weirs for determining their effect on Q/H characteristcs. The experiment is carried out on a thin-plate weir with a rectangular notch at the Department of Water Structures at the Faculty of Civil Engeneering in Brno. Another part of the master´s thesis is data processing to get an idea about the impact of the phenomenon in real applications. Finally, options are recommended for follow-up research.
59

Selfpublishing v českém prostředí a změny na knižním trhu s ním spojené / Self-publishing v českém prostředí a změny na knižním trhu s ním spojené

Blažek, Radek January 2016 (has links)
One of the first Czech research papers on self-publishing. Even though unsuccessful and forbidden authors could publish a book on their own in the past, the current phenomenon of self-publishing can be arranged on-line in just a few clicks and for much cheaper. Self- publishing began to spread since circa 2005 - in the Czech Republic and abroad simultaneously. This thesis shows how the development has unfolded differently in the Czech Republic and in the USA, which is considered the cradle of this technology. The first chapter of this thesis analyzes the history of book publishing and many different ways to publish a book, and defines self-publishing. The second chapter shows how the new technologies and media influenced the expansion of self-publishing. The third chapter analyzes and puts into context some of the Czech and the American self-publishing portals, and compares the providers of these services. Many professionals - editors, authors, and literary critics - criticize self-publishing for its amateurism and low quality content, which this work takes into account as well. This paper also documents some of the rare cases of self-published authors, who managed to succeed despite the tough competition from traditional publishing houses. In the last chapter the whole process of self-publishing...
60

Design optimization of CSO CWS Key processes and development of a modelling toolkit / Optimisation du dimensionnement des filtres plantes pour le traitement des surverses de déversoir d’orage - Mécanismes clefs et développement d’un outils d’aide au dimensionnement

Ṕálfy, Tamás Gábor 20 December 2016 (has links)
En France les filtres plantés à écoulement vertical sont utilisés pour le traitement des surverses de déversoir d’orage (CSO en anglais). Ils sont efficaces pour le traitement des polluants ainsi que pour assurer un rôle de tampon hydraulique permettant de protéger les milieux hydriques superficiels. Ils ont la particularité de recevoir des effluents bruts dont la fréquence, l’intensité, la durée et les concentrations sont stochastiques. En conséquence de quoi l’optimisation du dimensionnement est particulièrement délicate. Dans ce travail, le dimensionnement est abordé suivant deux approches. D’une part en définissant les processus clefs pour une optimisation du dimensionnement et, d’autre part, en construisant un modèle dynamique simplifié (Orage)permettant de prendre en compte, sur le long terme, le caractère stochastique des évènements et les contraintes locales. Le cœur du modèle a été calibré et validé sur une large gamme d’évènements mesurées sur un site en taille réelle (site de Marcy l’Etoile). La qualité de la calibration a été validé aussi bien visuellement que statistiquement et la robustesse du modèle étudiée par une analyse de sensibilité (méthode de Morris). L’optimisation automatique du dimensionnement a nécessité la réalisation d’une boucle itérative également paramétrée et testée dans le cadre du site de Marcy l’Etoile et pour des cas théoriques. Les dimensionnements proposés ont été estimés réalistes. La définition des processus clefs du système de traitement, et le développement du modèle simplifié, a également été possible grâce à la simulation d’expérimentations sur colonnes par un modèle mécaniste (HYDRUS / CW2D). La paramétrisation des processus du modèle simplifié a été réalisée sur la base d’expérimentations détaillées sur le site de Marcy l’Etoile. Le site a été suivi pendant trois ans aussi bien par des prélèvements automatiques, des traçages, que des mesures en lignes (hydraulique, azote, teneur en eau). Parmi les processus calibrés, nous retiendrons i) l’importance du niveau de saturation de la base du filtre au début d’un évènement vis-à-vis des court circuits hydrauliques, ii) la définition des capacités d’adsorption de l’azote ammoniacale de différents matériaux (pouzzolane, mélange de sable et de zéolite) et iii), la définition des cinétiques de nitrification suivant la température et quantité d’azote ammoniacal adsorbé. Si les performances de l’ouvrage sont hautes pour les paramètres majeurs (MES, DCO, N-NH4), l’impact du dimensionnement, de la gestion et des facteurs environnementaux sur les performances et l’accumulation de boue a été étudié. De plus, quelques suivis ont été réalisés sur les métaux et les HAP. Ces mesures ont permis non seulement de calibrer le logiciel Orage mais aussi de proposer des modifications pour l’amélioration du dimensionnement. / Constructed wetlands for combined sewer overflow treatment (CSO CWs) are vertical flow filters in France. They effectively remove pollutants and mitigate hydraulic peaks, which protects natural waters. They receive unsettled flows with stochastic return periods, volumes and concentrations, making design optimization difficult. In the presented work, design is targeted from two sides. First, the scientific basis is laid down for the design-support software Orage. The tool is model-based and as such, it considers the stochasticity of CSOs site-specifically. Its core model has been calibrated and then verified by a range of tests. Simulations fit to measured data from a full-scale CSO site (Marcy l’Etoile). The goodness of fit is evaluated visually and statistically. Model robustness has been confirmed by a sensitivity analysis (Morris method). After this, the iterative shell has been parameterized and tested (the software element doing automatic optimization). The design proposals of the tool have been found realistic. The other approach to target optimization has been a detailed field research at Marcy l’Etoile. The site at Marcy l’Etoile has been monitored for three years, using automatic samplers and online probes. The filling of the porous media at event start proves and explains shortcutting behaviour. Adsorption capacities have been quantified for pozzolana and a sand and zeolite mixture. A temperature-dependent equation is calibrated to calculate nitrification rate. System efficiency is high for target pollutants (TSS, COD, NH4-N). Design, operational and environmental factors have been analysed to seek potential effects on removal performances and sludge accumulation. Additionally, PAHs and metals are indicated for a few selected events. The field results were essential to calibrate Orage and to see options for design improvements. The understanding of CSO CWs and the development of Orage was promoted also by simulating lab-scale columns using the process-based model package HYDRUS / CW2D.

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