• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 10
  • 10
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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.
1

Vyžuonos upės ekologinė charakteristika / Ecological characteristic of Vyžuona river

Kazlauskienė, Rasa 09 June 2006 (has links)
Work object – Vyžuona river, which has 26 km lenght, is left affluent of Šventoji river, belongs to subbasin of Šventoji river and runs from northeast to southwest of Lithuania. Work aim – identify water quality and bounded with it live organisms of Vyžuona river. Work tasks – analyse physical-chemical water parameters of Vyžuona river, identify varietal composition of organisms, define and evaluate contamination of river objects. Work results – After the reasearch was made there was defined that Vyžuona river in Utena town (1 km from Krašuona river and Vieša river junction) belongs to average contaminated rivers category measuring by parameters of water quality: common nitrogen quantity 1.9 times exceeds permissible quotas, 68.6 % of common nitrogen is composed of nitrate nitrogen, BDS7 quantity 2,7 times exceeds the LDK, concentration of phosphates 2.3 times exceeded permissible quotas. Krašuona river and Vieša river runs trough private houses section, which has no central sewer and that is the reason why mentioned rivers are bearing domestic contaminants into Vyžuona river. According to 2004-2006 data below the outlet from drain mechanism of UAB „Utenos vandenys“ refinement system there was found concentration of phosphorus which averagely 1,75 times, common nitrogen 1,1 times and BDS7 1,7 times less in comparison with river part in centre of Utena town above UAB „Utenos vandenys“. That may be explained by UAB „Utenos vandeys“ affect, which drains large amount of enough... [to full text]
2

Biržų miesto įtaka Tatulos upės vandens kokybei / Influence Birzai town to Tatula River Water Quality

Drevinskas, Dalius 10 June 2005 (has links)
The master student’s work analyzes water quality of the river Tatula above and below the tributary Juodupė saturated with municipal wastewater of Biržai town. Study object. The river Tatula is a 66.2-km long right tributary of the Mūša. The river Tatula belongs to the river Lielupė basin located in northern part of Lithuania. The Tatula is flowing via cultivated karst region. Objective of work: to determine the changes in water quality of the river Tatula within the period of 1994-2004, when old wastewater treatment facilities were functioning in Biržai town and the new facilities started working in 2003. Study methodology. The study is based on the data of water quality measurements conducted by the United Research Center of the Ministry of Environment as well as additional data collected by the author in 2003-2004 in the river Tatula above the Juodupė inflow (distance from the outlet 18.8 km; basin area 191.4 km2) and below the tributary (distance from the outlet 17.5 km, basin area 283 km2). To estimate the changes in water quality during the study period, 26 parameters indicating water quality were analyzed; the changes in concentrations of nitrogen and phosphorus were considered as topical issues. Water quality was estimated on the basis of river water classification. Water samples were analyzed in the laboratory of wastewater treatment facilities of Biržai town. Study results. As the study results have shown, according to all water quality parameters the stretch of... [to full text]
3

Monitoramento da qualidade da água do Rio Grande Bacia do Rio Paraíba do Sul / Monitoring of water quality in the Rio Grande - Paraíba River Basin South

Leão, Marina Mendonça 22 February 2011 (has links)
Made available in DSpace on 2015-03-26T13:28:02Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1211971 bytes, checksum: 0f6618d19ac83222d911f8105b6a9ec9 (MD5) Previous issue date: 2011-02-22 / The assessment of water quality in the Rio Grande, a tributary basin of the Paraíba do Sul, was performed by monitoring physical-chemical, microbiological and hydrobiological parameters to check their correlation with changes in the diversity of habitats and microhabitats and determine the impact of modification of water quality on biological communities in the future. Monitoring physical, chemical and biological water was conducted at eleven points in Bom Jardim, São Sebastião do Alto and Santa Maria Madalena (RJ) in eight collection campaigns in the months of June, August and December 2008, May, April , July and October 2009 and January 2010. The parameters analyzed include metals (arsenic, barium, cadmium, lead, copper, chromium, mercury and zinc), phenols, dissolved oxygen, fecal coliforms, pH, biochemical oxygen demand, total nitrogen, ammonia, nitrites, nitrates, total phosphorus, temperature, turbidity, total solids and phytoplankton, zooplankton and zoobenton. Collections and analyses were performed according to Standard Methods for the Examination of Water and Wastewater (APHA, 2005). The data was converted to quality indexes - water quality index (WQI), toxicity index (TI), trophic state index (TSI), index of water quality for protection of aquatic life and aquatic communities (LAI) and Shannon-Wiener index (H'). Examination of the and relationships among variables and indices showed that while the WQI and LAI consistently pointed to good water quality, the biological indices indicated poor water quality. It was also verified that at points where there were higher concentrations of toxic substances, phosphorus and organic matter, non-tolerant species were absent from the hydrobiological communities (phytoplankton, zooplankton and zoobenton), suggesting contamination by industrial wastes. / A avaliação da qualidade da água do Rio Grande, afluente da bacia do Rio Paraíba do Sul, foi realizada através do monitoramento de parâmetros físicos e químicos, microbiológicos e hidrobiológicos para verificar sua correlação com alterações na diversidade de habitats e microhabitats e determinar o impacto da modificação da qualidade de água sobre as comunidades biológicas. O monitoramento da qualidade da água foi realizado em onze pontos nos municípios de Bom Jardim, São Sebastião do Alto e Santa Maria Madalena (RJ) em oito campanhas de coleta nos meses de junho, agosto e dezembro de 2008; maio, abril, julho e outubro de 2009 e janeiro de 2010. Os parâmetros quantificados incluem metais (arsênio, bário, cádmio, chumbo, cobre, cromo, mercúrio e zinco), fenóis, oxigênio dissolvido, coliformes termotolerantes, pH, demanda bioquímica de oxigênio, nitrogênio total, amônia, nitritos, nitratos, fósforo total, temperatura, turbidez, sólidos totais e fitoplâncton, zooplâncton e zoobenton. As coletas das amostras e as análises físicas e químicas, microbiológicas e hidrobiológicas foram realizadas conforme os procedimentos dispostos no Standard Methods for the Examination of Water and Wastewater (APHA, 2005). Os dados gerados foram convertidos em índices de qualidade índice de qualidade da água (IQA), índice de toxicidade (IT), Índice do Estado Trófico (IET), Índices de Qualidade das Águas para Proteção da Vida Aquática e de Comunidades Aquáticas (IVA) e índice Shannon-Wiener (H ) sendo realizada a interpretação das variáveis individuais e a relação com os demais. Enquanto IQA e IVA apontontaram para qualidade regular a ótima durante o período e monitoramento, os índices biológicas apontaram para qualidade de ruim a péssimo na maioria do tempo. Foi possível verificar que nos pontos onde foram observados maiores concentrações de substâncias tóxicas, fósforo e matéria orgânica, houve ausência de espécies não tolerantes e presença de espécies tolerantes nas comunidades hidrobiológicas (fitoplâncton, zooplâncton e zoobenton), evidenciando efeitos de contaminação por despejos industriais.
4

DYNAMIC HARMONIC DOMAIN MODELING OF FLEXIBLE ALTERNATING CURRENT TRANSMISSION SYSTEM CONTROLLERS

Vyakaranam, Bharat GNVSR January 2011 (has links)
No description available.
5

Avaliação temporal e espacial da qualidade da água no lago da Usina Hidrelétrica de Miranda, Região do Triângulo Minas Gerais.

Flauzino, Fabrício Silvério 28 August 2008 (has links)
This work aims to evaluate in time and space the quality of the lake water of the Miranda hydroelectric power plant by means of physicochemical and bacteriologic analyses. The collections of samples were made in two distinct seasons of the year : dry and rainy in the years of 2003, 2004, 2005, 2006 and 2007. Results of the analyses indicated considerable variations in the biochemical demand of oxygen, of the chemical demand of oxygen, of the dissolved oxygen, of oils and grease, of total dissolved solid, of the transparency, of the turbidness and of the bacteria presence of the coliform group. The values of the samples were interpreted in function of the limits of acceptance established by the Resolut ion 357 of CONAMA (2005). To help in the understanding of the results of the physicochemical and bacteriologic analyses, the area of study was mapped in what concerns the usage and occupation of the lands. This mapping identif ied the presence of 70,55% of antropic usage, 26,77% of natural vegetation cover and 2,68% occupied by water bodies. The map with dist ribution of the Water Quality Indices (WQI) points out that the major varies f rom great (79< WQI<100) to regular (36< WQI<51). The evaluation of physical, chemical and biological variations of the water of Miranda Lake allied to techniques of geoprocessing, allowed a better knowledge of the envi ronmental condi tions of the study area, and the results obtained can be used as sources of primary data to promote the planning and local and regional envi ronmental gestalt. / Este trabalho possui o objetivo de avaliar temporal e espacialmente a qualidade da água do lago da Usina Hidrelétrica de Miranda por meio de análises f ísico-químicas e bacteriológicas. As coletas de amostras de água foram realizadas em duas estações distintas do ano: seca e chuvosa nos anos de 2003, 2004, 2005, 2006 e 2007. Resultados das análises realizadas indicaram variações consideráveis dos valores da Demanda Bioquímica de Oxigênio, da Demanda Química de Oxigênio, do Oxigênio Dissolvido, de Óleos e Graxas, de Sólidos Dissolvidos Totais, da Transparência, da Turbidez e da presença de bactérias do grupo Coliformes. Os valores dos ensaios foram interpretados em função dos limites de aceitação individuais para cada substância em cada classe, visando a atendimento aos padrões de qualidade das águas estabelecidos pela Resolução nº 357 do CONAMA (2005). Para auxiliar no entendimento dos resultados das análises físico-químicas e bacteriológicas, a área de estudo foi mapeada quanto ao uso e ocupação das terras. Este mapeamento identificou a presença de 70,55 % do uso antrópico, 26,77% de cobertura vegetal natural e 2,68 % ocupada pelos corpos d água. O mapa com distribuição do Índice de Qualidade da Água (IQA) most ra que a maioria oscila entre ótimo (79>IQA100) e regular (36>IQA51). A avaliação de variáveis f ísicas, químicas e biológicas da água do lago de Miranda, aliada a técnicas de geoprocessamento, propiciaram um melhor conhecimento das condições ambientais da área de estudo, e os resultados obtidos podem ser utilizados como fontes de dados primários para promover o planejamento e gestão ambiental local e regional. / Mestre em Geografia
6

Analyse comparative de modèles de la qualité des habitats basés sur la densité instantanée et cumulative de poissons

Guéveneux-Julien, Cynthia 05 1900 (has links)
Les écosystèmes aquatiques contiennent environ 25% de la biodiversité globale et sont parmi les plus affectés par l’activité humaine. Cela est entre autres causé par la position de « receveur » des rivières, lacs et océans dans leur bassin versant. Les espèces aquatiques, en eau douce particulièrement, sont ainsi hautement à risque d’être affectées par l’activité humaine. La protection de ces espèces peut inclure la protection et la restauration de leurs habitats. Les modèles de qualité d’habitats (MQH) peuvent être utilisés afin de déterminer quels habitats protéger et restaurer. Les MQH définissent la relation entre un indice de qualité d’habitats (IQH, e.g. densité) et des conditions environnementales. Toutefois, la performance des MQH dépend de l’IQH sélectionné. Ici, notre objectif est de comparer des MQH basés sur deux IQH estimés pour des poissons en rivière : 1) la densité instantanée, échantillonnée en transect par plongée en apnée et 2) la densité cumulative, échantillonnée en point fixe par caméra-vidéo en stéréo. Au total, douze modèles ont été construits et nos analyses indiquent que les MQH basés sur la densité instantanée ont des capacités explicatives significativement supérieures. Les variables environnementales retenues pour expliquer la distribution de chaque espèce sont toutefois différentes. Cela semble être causé en partie par des différences inhérentes à l’échantillonnage (e.g. échelle spatiale). Ces résultats démontrent que la densité instantanée en tant qu’IQH produit des MQH aux capacités explicatives supérieures et que les deux IQH semblent donner des informations complémentaires sur les caractéristiques des habitats à protéger et à restaurer. / Aquatic ecosystems contain approximately 25% of the global biodiversity and are among the most affected by human activity. This may be caused by the position of “receivers” rivers, lakes and oceans have in their watershed. Aquatic species, specially in freshwater, are thus at high risk of being affected by human activity. Assuring the survival of these species may include protecting and restoring their habitats. Habitat quality models (HQM) can be used to determine which habitats to protect and how to restore damaged habitats. HQM are relationships between habitat quality indices (HQI, e.g., density) and environmental conditions prevailing in those habitats. However, how well an HQM performs depends on the chosen HQI it is computed with. For this research, we compared HQM based on two HQI estimated for fish in a river : 1) instantaneous density, sampled by transect snorkeling survey and 2) cumulative density, sampled by fixed stereo-video recording. Analyses of twelve HQM show that, contrary to our hypothesis, HQM based on instantaneous density had higher explanatory capacities. However, environmental conditions selected by both types of HQM to explain a species’ distribution were different. This may in part be explained by inherent differences of the sampling methods (e.g., spatial scale). We conclude that instantaneous density as HQI produces HQM of higher explanatory capacities, yet both HQI may provide complementary information on the characteristics of habitats to protect and restore.
7

Index kvality napětí pro indikativní hodnocení kvality napětí v distribuční síti / Voltage quality index for distribution systems voltage quality benchmarking

Hausner, Josef January 2015 (has links)
This Master’s thesis deals with design of a new method for voltage quality benchmarking using voltage quality index. This index should determinate total voltage quality in the power grid and compare voltage quality in different places. There is design of several algorithms which value measured parameters in this thesis. The best suitable algorithm is selected. Program for this algorithm was compiled in GUI Matlab. The algorithm is verified by using measured parameters in this program. The last part of this thesis is focused on possible usage of created algorithm.
8

Sustainable Bioenergy Feedstock Production Using Long-Term (1999-2014) Conservation Reserve Program Land

Raut, Yogendra Y. 08 August 2017 (has links)
No description available.
9

Caractérisation et stabilité de la matière organique du sol en contexte montagnard calcaire : proposition d'indicateurs pour le suivi de la qualité des sols à l'échelle du paysage / Characterization and stability of soil organic matter in calcareous mountain : proposal of indicators for soil quality monitoring at the landscape scale

Saenger, Anaïs 16 April 2013 (has links)
Les sols de montagne représentent d'importants réservoirs de carbone (C) potentiellement vulnérables aux changements climatiques et changements d'usage qui les affectent de manière amplifiée. Or la grande variabilité de ces milieux, leur faible accessibilité ainsi que le manque d'outils de mesure appropriés limitent nos connaissances qui restent aujourd'hui très fragmentaires en ce qui concerne les stocks, la chimie et la réactivité du carbone organique des sols (COS). Ces informations sont pourtant nécessaires pour appréhender l'évolution de ces sols et de leur C dans ce contexte de changements globaux. Les objectifs de ce travail de thèse étaient (i) d'accéder à une meilleure compréhension de la nature, de la stabilité et de la vulnérabilité du COS dans une mosaïque d'écosystèmes des Préalpes calcaires (massif du Vercors), (ii) de rechercher des outils de caractérisation rapides et fiables adaptés à l'étude et au suivi du COS à l'échelle du paysage, et enfin (iii) de proposer des indices pour l'évaluation et le suivi de la qualité des sols en milieu de montagne. Dans un premier temps, nous avons testé l'application de la pyrolyse Rock-Eval pour l'étude du COS à grande échelle sur un ensemble d'unités écosystémiques. Nous avons ensuite comparé la pyrolyse Rock-Eval à deux techniques classiques d'étude de la matière organique du sol (MOS) : le fractionnement granulodensimétrique de la MOS et la spectroscopie moyen infrarouge. Ces approches analytiques couplées nous ont permis de quantifier les stocks de C à l'échelle de la zone d'étude et d'expliquer la stabilité et la vulnérabilité du COS sous des angles variés. Les facteurs responsables des patrons observés dans les différentes unités écosystémiques sont discutés. Ce travail a également confirmé la pertinence de l'outil Rock-Eval pour répondre aux objectifs fixés. Parallèlement, des approches biologiques nous ont permis d'évaluer l'importance de la composante microbienne dans ces sols. Enfin, des indices évaluant le statut organique des sols (stockage de COS, fertilité des sols, vulnérabilité du COS) sont proposés pour constituer des outils de gestion et d'aide à la décision. / Mountain soils are major reservoirs of carbon (C), potentially vulnerable to climate and land use changes that affect them significantly. However, the great variability of these soils, their limited accessibility and the lack of appropriate measurement tools restrict our knowledge. Today, our comprehension of the biogeochemistry of mountain soils remains very incomplete regarding stocks, chemistry and reactivity of soil organic carbon (SOC). Yet this information is necessary to understand the evolution of soil carbon in the current context of global change. The objectives of this work were (i) to gain a better understanding of the nature, stability and vulnerability of SOC in a mosaic of ecosystems in a calcareous massif in the Alps (Vercors massif), (ii) to search for fast and reliable characterization tools, suitable for the study and monitoring of COS at the landscape scale, and (iii) to propose indicators for the assessment and monitoring of soil quality in mountain regions. As a first step, we tested the application of Rock-Eval pyrolysis for the study of COS at large-scale on a set of ecosystem units. Then, we compared the Rock-Eval approach to two conventional techniques for soil organic matter (SOM) study: the particle-size fractionation of SOM, and the mid-infrared spectroscopy. These coupled analytical approaches allowed us to quantify C stocks across the study area, and explain the stability and the vulnerability of COS at various angles. Factors responsible for the patterns observed in the different eco-units are discussed. This work also confirmed the relevance of the Rock-Eval tool to achieve our previous objectives. Biological approaches allowed us to assess the significance of microbial pool in these soils. Finally, indices assessing the status of SOM (SOC storage, soil fertility, vulnerability COS) were proposed and constituted interesting management tools for decision-makers.
10

Dynamic Clustering and Visualization of Smart Data via D3-3D-LSA / with Applications for QuantNet 2.0 and GitHub

Borke, Lukas 08 September 2017 (has links)
Mit der wachsenden Popularität von GitHub, dem größten Online-Anbieter von Programm-Quellcode und der größten Kollaborationsplattform der Welt, hat es sich zu einer Big-Data-Ressource entfaltet, die eine Vielfalt von Open-Source-Repositorien (OSR) anbietet. Gegenwärtig gibt es auf GitHub mehr als eine Million Organisationen, darunter solche wie Google, Facebook, Twitter, Yahoo, CRAN, RStudio, D3, Plotly und viele mehr. GitHub verfügt über eine umfassende REST API, die es Forschern ermöglicht, wertvolle Informationen über die Entwicklungszyklen von Software und Forschung abzurufen. Unsere Arbeit verfolgt zwei Hauptziele: (I) ein automatisches OSR-Kategorisierungssystem für Data Science Teams und Softwareentwickler zu ermöglichen, das Entdeckbarkeit, Technologietransfer und Koexistenz fördert. (II) Visuelle Daten-Exploration und thematisch strukturierte Navigation innerhalb von GitHub-Organisationen für reproduzierbare Kooperationsforschung und Web-Applikationen zu etablieren. Um Mehrwert aus Big Data zu generieren, ist die Speicherung und Verarbeitung der Datensemantik und Metadaten essenziell. Ferner ist die Wahl eines geeigneten Text Mining (TM) Modells von Bedeutung. Die dynamische Kalibrierung der Metadaten-Konfigurationen, TM Modelle (VSM, GVSM, LSA), Clustering-Methoden und Clustering-Qualitätsindizes wird als "Smart Clusterization" abgekürzt. Data-Driven Documents (D3) und Three.js (3D) sind JavaScript-Bibliotheken, um dynamische, interaktive Datenvisualisierung zu erzeugen. Beide Techniken erlauben Visuelles Data Mining (VDM) in Webbrowsern, und werden als D3-3D abgekürzt. Latent Semantic Analysis (LSA) misst semantische Information durch Kontingenzanalyse des Textkorpus. Ihre Eigenschaften und Anwendbarkeit für Big-Data-Analytik werden demonstriert. "Smart clusterization", kombiniert mit den dynamischen VDM-Möglichkeiten von D3-3D, wird unter dem Begriff "Dynamic Clustering and Visualization of Smart Data via D3-3D-LSA" zusammengefasst. / With the growing popularity of GitHub, the largest host of source code and collaboration platform in the world, it has evolved to a Big Data resource offering a variety of Open Source repositories (OSR). At present, there are more than one million organizations on GitHub, among them Google, Facebook, Twitter, Yahoo, CRAN, RStudio, D3, Plotly and many more. GitHub provides an extensive REST API, which enables scientists to retrieve valuable information about the software and research development life cycles. Our research pursues two main objectives: (I) provide an automatic OSR categorization system for data science teams and software developers promoting discoverability, technology transfer and coexistence; (II) establish visual data exploration and topic driven navigation of GitHub organizations for collaborative reproducible research and web deployment. To transform Big Data into value, in other words into Smart Data, storing and processing of the data semantics and metadata is essential. Further, the choice of an adequate text mining (TM) model is important. The dynamic calibration of metadata configurations, TM models (VSM, GVSM, LSA), clustering methods and clustering quality indices will be shortened as "smart clusterization". Data-Driven Documents (D3) and Three.js (3D) are JavaScript libraries for producing dynamic, interactive data visualizations, featuring hardware acceleration for rendering complex 2D or 3D computer animations of large data sets. Both techniques enable visual data mining (VDM) in web browsers, and will be abbreviated as D3-3D. Latent Semantic Analysis (LSA) measures semantic information through co-occurrence analysis in the text corpus. Its properties and applicability for Big Data analytics will be demonstrated. "Smart clusterization" combined with the dynamic VDM capabilities of D3-3D will be summarized under the term "Dynamic Clustering and Visualization of Smart Data via D3-3D-LSA".

Page generated in 0.0532 seconds