181 research outputs found
Identifying discontinuities of flood frequency curves
Discontinuities in flood frequency curves, here referred to as flood divides, hinder the estimation of rare floods. In this paper we develop an automated methodology for the detection of flood divides from observations and models, and apply it to a large set of case studies in the USA and Germany. We then assess the reliability of the PHysically-based Extreme Value (PHEV) distribution of river flows to identify catchments that might experience a flood divide, validating its results against observations. This tool is suitable for the identification of flood divides, with a high correct detection rate especially in the autumn and summer seasons. It instead tends to indicate the emergence of flood divides not visible in the observations in spring and winter. We examine possible reasons of this behavior, finding them in the typical streamflow dynamics of the concerned case studies. By means of a controlled experiment we also re-evaluate detection capabilities of observations and PHEV after discarding the highest maxima for all cases where both empirical and theoretical estimates display flood divides. PHEV mostly confirms its capability to detect a flood divide as observed in the original flood frequency curve, even if the shortened one does not show it. These findings prove its reliability for the identification of flood divides and set the premises for a deeper investigation of physiographic and hydroclimatic attributes controlling the emergence of discontinuities in flood frequency curves.publishedVersio
Educação do campo : um olhar sobre Almirante Tamandaré
Orientador :Monografia (especialização) - Universidade Federal do Paraná, Setor de ..., Curso de Especialização em ...Inclui referência
Minimalinvasiv implantierbare Herzklappenprothesen: Beiträge zur Beurteilung der Qualitätsparameter und zur hydrodynamischen Charakterisierung von Klappendesigns
Das Ziel der vorliegenden Arbeit ist die Entwicklung und Adaption von In-vitro-Prüfmethoden zur hydrodynamischen Charakterisierung von TAVP und insbesondere zur detaillierten Analyse der paravalvulären Regurgitation. Die Beiträge dieser Arbeit sollen dem wachsenden Anspruch an Sicherheit und Effektivität von Medizinprodukten imgerecht werden und die Limitationen bestehender Prüfmethoden überwinden. Auf diese Weise sollen neue In-vitro-Standards zur entwicklungsbegleitenden Beurteilung von TAVP erarbeitet und zukünftige Implantat-Generationen verbessert werden
Fließgewässer in Baden-Württemberg als Lebensraum ausgewählter Artengruppen
Fließgewässer und ihre angrenzenden Auen bieten vielfältige Lebensräume für zahlreiche Tier- und Pflanzenarten. Diese Vielfalt zu sichern und vorhandene Defizite abzubauen, ist Ziel der naturnahen Gewässerentwicklung, wie sie im Wassergesetz für Baden-Württemberg verankert ist. Als Grundlage hierfür nimmt die vorliegende Schrift eine Bewertung der baden-württembergischen Fließgewässer als Lebensraum für die Artengruppen Vögel, Laufkäfer, Libellen und Muscheln vor (Karten 1 5, siehe Anhang). Einen Überblick gibt die Karte "Fließgewässer in Baden-Württemberg als Lebensraum ausgewählter Artengruppen", 2001 H im Maßstab 1 :350.000 (Anhang). Diese erste Analyse im Landesmaßstab, die ausschließlich durch die Sammlung und Aufbereitung verstreut vorliegender Daten entstand, soll den Zustand der Fließgewässer als Lebensraum von Arten verdeutlichen, prioritäre Gewässerabschnitte für den Gewässerschutz aufzeigen, aber auch Hinweise für die Gewässerentwicklung geben. Auf der Grundlage der Einzelbewertungen für die vier Artengruppen wurde eine Gesamtbewertung der Gewässer vorgenommen (Karte 6, siehe Anhang). Entstanden ist also neben Einzelbewertungen für die Artengruppen eine überblicksartige Gesamtbewertung der baden-württembergischen Fließgewässer als Artenlebensräume
Dissolved oxygen isotope modelling refines metabolic state estimates of stream ecosystems with different land use background
Dissolved oxygen (DO) is crucial for aerobic life in streams and rivers and mostly depends on photosynthesis (P), ecosystem respiration (R) and atmospheric gas exchange (G). However, climate and land use changes progressively disrupt metabolic balances in natural streams as sensitive reflectors of their catchments. Comprehensive methods for mapping fundamental ecosystem services become increasingly important in a rapidly changing environment. In this work we tested DO and its stable isotope (OO) ratios as novel tools for the status of stream ecosystems. For this purpose, six diel sampling campaigns were performed at three low-order and mid-latitude European streams with different land use patterns. Modelling of diel DO and its stable isotopes combined with land use analyses showed lowest P rates at forested sites, with a minimum of 17.9 mg m h. Due to high R rates between 230 and 341 mg m h five out of six study sites showed a general heterotrophic state with P:R:G ratios between 0.1:1.1:1 and 1:1.9:1. Only one site with agricultural and urban influences showed a high P rate of 417 mg m h with a P:R:G ratio of 1.9:1.5:1. Between all sites gross G rates varied between 148 and 298 mg m h. In general, metabolic rates depend on the distance of sampling locations to river sources, light availability, nutrient concentrations and possible exchanges with groundwater. The presented modelling approach introduces a new and powerful tool to study effects of land use on stream health. Such approaches should be integrated into future ecological monitoring
The air pressure effect on the homogeneous nucleation of carbon dioxide by molecular simulation
Vapour-liquid equilibria (VLE) and the influence of an inert carrier gas on
homogeneous vapour to liquid nucleation are investigated by molecular
simulation for quaternary mixtures of carbon dioxide, nitrogen, oxygen, and
argon. Canonical ensemble molecular dynamics simulation using the
Yasuoka-Matsumoto method is applied to nucleation in supersaturated vapours
that contain more carbon dioxide than in the saturated state at the dew line.
Established molecular models are employed that are known to accurately
reproduce the VLE of the pure fluids as well as their binary and ternary
mixtures. On the basis of these models, also the quaternary VLE properties of
the bulk fluid are determined with the Grand Equilibrium method.
Simulation results for the carrier gas influence on the nucleation rate are
compared with the classical nucleation theory (CNT) considering the "pressure
effect" [Phys. Rev. Lett. 101: 125703 (2008)]. It is found that the presence of
air as a carrier gas decreases the nucleation rate only slightly and, in
particular, to a significantly lower extent than predicted by CNT. The
nucleation rate of carbon dioxide is generally underestimated by CNT, leading
to a deviation between one and two orders of magnitude for pure carbon dioxide
in the vicinity of the spinodal line and up to three orders of magnitude in
presence of air as a carrier gas. Furthermore, CNT predicts a temperature
dependence of the nucleation rate in the spinodal limit, which cannot be
confirmed by molecular simulation
ESTÁGIO OBRIGATÓRIO NA SEÇÃO DE POLÍTICAS AFIRMATIVAS E ASSUNTOS ESTUDANTIS E COMUNITÁRIOS – SEPOL, DA UNIVERSIDADE FEDERAL DO PARANÁ SETOR – LITORAL
Dentro das Políticas Públicas temos as ações afirmativas ou políticas de ação afirmativa e compondo uma parte desta encontramos a Política de Cotas, e para este relato essas direcionadas especificamente para o Ensino Superior, assim delimitamos o objeto que trataremos neste trabalho. Neste contexto, o relato apresenta a experiência da Seção de Políticas Afirmativas e Assuntos Estudantis - SEPOL, ao recepcionar dois estudantes do curso de Administração Pública da UFPR - Setor Litoral para realização do estágio obrigatório. O presente relato apresenta uma análise dos trabalhos desenvolvidos durante o período de estágio na Seção, especificamente na unidade de Políticas Afirmativas - Educação Étnico Racial. Descreveremos a aplicação e construção do Plano de Atividades com relação ao Currículo doCurso e a Lei de Diretrizes e Bases - LDB.Palavras-chave: políticas públicas, ações afirmativas, política de cotas
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