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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.
141

Uma introdução à Cp (X) / An introduction on Cp(X)

Maués, Bartira 13 April 2015 (has links)
Neste trabalho estudamos algumas propriedades do espaço das funções contínuas munido da topologia da convergência pontual. Começamos estudando o espaço Cp(X) de forma geral, verificando que propriedades topológicas principais valem em Cp(X), usando teoremas de dualidade entre X e Cp(X). Em seguida estudamos a relação da estrutura topológica de X e a estrutura algébrica e topológica de Cp(X), onde o Teorema de Nagata é fundamental. Observamos algumas propriedades de X que são preservadas por l-equivalência ou t-equivalência, ou seja, que são determinadas pela estrutura linear topológica, ou pela estrutura topológica de Cp(X), respectivamente. Por último estudamos as condições para que Cp(X) seja um espaço de Lindelöf. Concluímos com a prova de Okunev de que o número de Lindelöf de Cp(X) é igual ao número de Lindelöf de Cp(X)xCp(X), para espaços fortemente zero-dimensionais X. / In this work we study some properties of the space of continuous functions endowed with the topology of pointwise convergence. We begin by studying the space Cp(X) in general terms, verifying that the main topological properties are valid in Cp(X), using duality theorems between X and Cp(X). Next we study the relationship between the topological structure of X and the algebraic as well as topological structure of Cp(X), in which the Nagata theorem theorem is essential. We observe some properties of X, which are preserved by l-equivalence or t-equivalence, i.e., which are respectively determined either by the linear topological structure of Cp(X) or by its topological one. Finally we study in which conditions Cp(X) is a Lindelöf space. We conclude with the proof of Okunev that the Lindelöf number of Cp(X) is equal to the Lindelöf number of Cp(X)xCp(X), for strongly zero-dimensional spaces X.
142

Matéria orgânica e a sorção de herbicidas em solos sob plantio direto nas regiões tropical e subtropical do Brasil / Organic matter and herbicides sorption in soils under no-tillage in tropical and subtropical regions of Brazil

Bonfleur, Eloana Janice 27 June 2014 (has links)
O sistema de plantio direto (SPD) é extensivamente utilizado no Brasil por tratar-se de prática conservacionista, capaz de melhorar a qualidade do solo e diminuir os custos da produção em relação ao plantio convencional. Neste sistema as condições edafoclimáticas distintas e a adoção de diferentes culturas na entressafra sugerem diferenças na distribuição e na qualidade da matéria orgânica de solos (MOS), devido ao tempo de resiliência da palha em cobertura. A interação entre a MOS e os pesticidas já foi bastante estudada, mas apenas parcialmente esclarecida uma vez que a maioria dos estudos considera a MOS como um compartimento homogêneo, ignorando o papel de seus diferentes componentes moleculares. Assim sendo, o objetivo principal deste trabalho é avaliar o efeito da composição, distribuição e interação com a fase mineral da MOS na sorção de herbicidas aplicados às culturas de soja e milho, sob sistema plantio direto em diferentes condições edafoclimáticas: tropical (Região Centro-Oeste) e subtropical (Região Sul). Os herbicidas alaclor, bentazon e imazetapir foram selecionados devido às suas importâncias junto a essas culturas e suas propriedades físico-químicas distintas. Para tal, soram amostrados 12 Latossolos, na camada de 0 a 5 cm excluindo a palha de superfície, sendo seis representativos do Estado do Paraná (clima subtropical) e seis representativos do Estado do Mato Grosso do Sul (clima tropical). A determinação dos atributos físico e químicos, formas de ferro e alumínio, estudo da qualidade da MOS por espectroscopia de Ressonância Nuclear Magnética do 13C e fracionamento físico dos solos foram os métodos utilizados. Foi observado maior acúmulo de carbono orgânico (C.O) nos solos subtropicais devido ao maior teor de óxidos de alumínio de baixa cristalinindade, além da maior precipitação. Para os solos de ambas as regiões, a estabilização da MOS ocorre através da formação de complexos nos agregados tamanho argila ( ~ 50% do teor de C.O). Em relação às interações com a fase mineral, observou-se que os óxidos de alumínio estão relacionados à proteção física da MOS enquanto que os óxidos de ferro parecem participar das reações de decomposição e humificação através da formação de complexos com grupos carboxílicos. Para o alaclor, a presença de formas de alumínio de baixa cristalinidade diminuiu a sua sorção a MOS, entretanto a sorção deste herbicida não foi correlacionada a nenhum grupo funcional. Para o bentazon, foi observada correlação positiva entre a sorção e materiais orgânicos mais decompostos e também, com o alumínio complexado a MOS. Para o imazetapir, houve correlações positivas com as formas de ferro e alumínio e o grupo funcional carboxil. Para os três herbicidas a maior sorção foi observada nos agregados de tamanho silte (53 a 2 ?m) e, de maneira geral, a sorção nos solos tropicais foi maior que nos subtropicais. O efeito da exposição de sítios de carga após o fracionamento físico dos solos foi evidente para o imazetapir incrementando sua sorção em comparação a sorção no solo inteiro o que evidencia a maior quantidade de sítios bloqueados nos solos tropicais. / No-tillage System (NT) is widely used in Brazil due to improve soil quality and reduce production costs compared to conventional tillage. Different climatic conditions and the adoption of different cultures in the offseason suggest differences in the distribution and quality of soil organic matter (SOM) due to the resilience time of straw in coverage in NT. Interactions between SOM and pesticides has been widely studied, but only partially elucidated. In most of studies, the MOS as a homogeneous compartment and there is not the knowledge about the role of its various molecular components. Therefore, the aim of this work is to evaluate the effect of the composition, distribution and interaction with the mineral phase of SOM on sorption of herbicides applied to soybean and corn under no-tillage in tropical (Central-west) and subtropical (South Region) soils. Alachlor, bentazon and imazethapyr herbicides were selected because of its large use in these cultures and different physicochemical properties. For this, it was sampled 12 soils at 0-5 cm layer excluding the straw surface, six representing the Paraná State (subtropical) and six representative of Mato Grosso de Sul State (tropical). Physical and chemical attributes, iron and aluminum forms, study of quality of SOM by Nuclear Magnetic Resonance Spectroscopy of 13C and soil physical fractionation methods were used for this purpose. Greater accumulation of organic carbon (OC) was observed in subtropical soils due to higher low crystalline aluminum oxides contents, in addition to lower temperatures and higher moisture in this region. For soils of both regions, the SOM stabilization occurs through the formation of complexes in the clay fraction (~ 50 % of the OC content). Regarding interactions with the mineral phase, it was observed that aluminum oxides are related to physical protection of SOM while iron oxides appear to participate in the decomposition and humification reactions by forming complexes with carboxylic groups. For alachlor, low crystallinity aluminum forms decreased its MOS sorption but sorption of this herbicide was not correlated with any functional group. For bentazon, positive correlation was observed between sorption and more decomposed organic material and with the complexed aluminum in MOS. For imazethapyr, there were positive correlations with iron and aluminum forms and carboxyl functional group. For the three herbicides better sorption was observed in the silt size fractions (53-2 ?m) and in general, sorption in tropical was higher than in subtropical soils. The effect of charge sites exposure after soil physical fractionation was evident for imazethapyr increasing its sorption compared to the whole soil which shows the greatest amount of blocked sites in tropical soils.
143

Ereigniswissen / Insights into event knowledge

Welke, Tinka 22 October 2014 (has links)
Ausgehend von dem Fokus der Ereignisrepräsentation auf die Patiens-Rolle (Personen und Objekte, die der im Ereignis stattfindenden Zustandsveränderung unterliegen) wird untersucht, ob die sich während des Ereignisses verändernden Merkmale des Patiens Bestandteil des Ereigniswissens sind und zur Repräsentation des chronologischen Verlaufs von Ereignissen beitragen. Dies wurde anhand der Bearbeitung von antonymen Adjektiven geprüft, die Anfangs- und Endmerkmale des Patiens eines zuvor dargebotenen Ereignisverbs benennen. Ausgewertet wurden behaviorale Daten und Blickbewegungen. Dabei wurden mit zeit-impliziten und zeit-expliziten Aufgaben folgende Ergebnisse erzielt: (1) Die Ereignisrepräsentation enthält sich verändernde Merkmale des Patiens. (2) Die Merkmale des Patiens werden abhängig von der angewandten Strategie (sprachliche vs. Simulationsstrategie) in einer chronologischen Abfolge mental simuliert. (3) Endmerkmale haben gegenüber Anfangsmerkmalen Priorität in der Ereignisrepräsentation. Sie sind im Ereignisverb impliziert und können so sprachlich bereitgestellt werden. (4) Die Zeiteffekte (Chronologie und Zielpräferenz) treten bereits unter automatischen Bedingungen (SOA 250 ms, zeit-implizite Aufgabe) auf. (5) Antwortstrategien wurden insbesondere durch Blickbewegungen indiziert. Antwortstrategien modifizieren die Zeiteffekte und geben Aufschluss über den Anteil der sprachlichen Verarbeitung und der Simulation. Insgesamt lässt sich aus den Untersuchungen schließen, dass die Veränderung des Patiens und damit Aspekte des zeitlichen Verlaufs von Ereignissen zur Ereignisrepräsentation gehören. Die Befundlage deutet auf ein dynamisches Zusammenspiel von sprachlichen und Simulationsprozessen bei der Repräsentation des zeitlichen Verlaufs hin. / This thesis comprises three investigations into the mental representation of events. Proceeding on the assumption that representations of events focus on the role of the patient (the person or object undergoing a change of state during the event), it is investigated whether the changing features of the patient form part of event knowledge and whether or not they contribute to the way in which the temporal progression of events is represented. The study involved time-implicit and time-explicit tasks that required participants to process antonymous adjectives denoting the source and resulting features of the patient involved in an event prime. Behavioural and eye movement data were analysed and the following results obtained: (1) The changing features of the patient form part of the representation of the event. (2) Depending on the strategy adopted (linguistic vs. simulation), patient features can be mentally simulated in chronological order. (3) Resulting features play a more prominent role in event representations than source features. Resulting features are implied by the event verb and can thus be accessed linguistically. (4) Temporal effects (preference for resulting features, effect of chronology) already occur in the automatic condition (SOA 250 ms, time-implicit tasks). (5) Response strategies are indicated by eye movements. Response strategies modify temporal effects and provide an indication of how much linguistic processing is taking place and how much simulation. All in all the investigations show that the change undergone by the patient, i.e. the aspect which expresses the temporal progression of an event, forms part of the representation of that event. The results point to a dynamic interplay of linguistic and simulation processing in the representation of temporal progression.
144

Widerspiegelung der Sprachproduktion im Hochfrequenzbereich des EEG

Riewe, Dagmar 22 February 1999 (has links)
In einer Pilotstudie sollten deutschsprachigen Probanden (n=28) in zwei Versuchsabschnitten kurze Sätze sprechen, die das Homonym "Leiter" im Sinne von "Steiggerät" bzw. "Teamchef" näher definieren. Das Homonym sollte am Satzanfang ohne Artikel genannt werden. Das Breitband-EEG (bis 2000 Hz, Zeitkonstante 1,5 s) wurde über F3, F4, C3 und C4 (Intern. 10-20-System) vor und kurz nach Sprachbeginn abgeleitet. Signalepochen des EEG- und Mikrophonsignals von 6 s Dauer wurden gespeichert. Off-line erfolgte die Auswertung der auf Sprachbeginn zentrierten und auf 1 Sekunde gekürzten EEG-Episoden. Es wurden vor Vokalisation motorische Bereitschaftspotentiale gefunden, die im gesamten Zeitbereich (750 ms prä- und 250 ms perireaktiv) wenig strukturiert sind und sich an den vier Ableitorten weder in ihrer Amplitude noch in ihrer Amplituden-Zeit-Struktur unterscheiden. Die Spektralanalyse der EEG-Signalstrecke zeigt unter beiden Versuchsbedingungen eine überproportional hohe Amplitude im [delta]-Band. Mit Hilfe der von Bartsch und Krüger entwickelten Subpotentialanalyse, die im Hochfrequenzbereich des EEG (10-400 Hz) dem "local field potential" ähnliche Phänomene nachweist, konnten in der Signalperiode des Bereitschaftspotentials positive und negative Subpotentiale ermittelt werden. Die Amplitude dieser Subpotentiale liegt zwischen 6 und 12[mycro]V. Der Zeitpunkt des Erscheinens der Subpotentiale wurde als Subpotentialevent (SPe) bezeichnet. Die SPe treten teils gruppiert und teils kohärent auf. Die Intervalle zwischen den SPe wurden histographisch aufgetragen, sie reichen vom 4 bis 15 ms. Auffallendstes Ergebnis war die unterschiedliche Struktur der SPe-Intervallhistogramme, die sich in den linksseitigen Ableitungen anders verhielten als in den rechtsseitigen. Möglicherweise sind diese Differenzen typisch für den eloquenten Unterschied. / During a pilot study, 28 german speeking subjects were supposed in two trial parts to speak in short sentences in order to define the german homonyme "Leiter" with the meaning "leader" respectively "manager". The homonyme should be used without any article at the beginning of the sentence. The EEG-activity (0-2000 Hz, time constant 1,5 sec) was recorded from F3, F4, C3 and C4 (international 10-20-system) before and after starting speech. Signalepochs of EEG-activity and microphone signals of 6 seconds were stored. The offline-evaluation was based on the centered and to the one second shortened EEG-episodes. Before staring speech there had been found a movement-related readines-potential (motor. Bereitschaftspotential), which had been less structured during the whole period of time (750ms pre- and 250 ms perireactive). Neither in their amplitude nor in their amplitude-time-structure distinctions were observed. The spectral analysis of EEG showed an overpropotional high amplitude in [delta]-band under both conditions of the trial. The subpotential-analysis developed by Bartsch and Krüger, which shows similar phenomenons as the "local field potentials" in the high frequency-EEG (10-400 Hz), could show positve and negative subpotentials during the period of the readiness-potential. The amplitudes of those subpotentials lay between 6 and 12[mycro]V. The point of time, when the subpotentials showed up, is called the subpotential-event (SPe). The SPe showed up partly in groups and partly coherent. The intervals between the SPe were put on histographically with a reach from 4 to 25 ms. The most striking result was the varying structure of the histography of the SPe-intervalls. The left-sided histography was conducted differently to the right-sided. May be that these distinctions are typical for the eloquent difference.
145

Critérios robustos de seleção de modelos de regressão e identificação de pontos aberrantes / Robust model selection criteria in regression and outliers identification

Guirado, Alia Garrudo 08 March 2019 (has links)
A Regressão Robusta surge como uma alternativa ao ajuste por mínimos quadrados quando os erros são contaminados por pontos aberrantes ou existe alguma evidência de violação das suposições do modelo. Na regressão clássica existem critérios de seleção de modelos e medidas de diagnóstico que são muito conhecidos. O objetivo deste trabalho é apresentar os principais critérios robustos de seleção de modelos e medidas de detecção de pontos aberrantes, assim como analisar e comparar o desempenho destes de acordo com diferentes cenários para determinar quais deles se ajustam melhor a determinadas situações. Os critérios de validação cruzada usando simulações de Monte Carlo e o Critério de Informação Bayesiano são conhecidos por desenvolver-se de forma adequada na identificação de modelos. Na dissertação confirmou-se este fato e além disso, suas alternativas robustas também destacam-se neste aspecto. A análise de resíduos constitui uma forte ferramenta da análise diagnóstico de um modelo, no trabalho detectou-se que a análise clássica de resíduos sobre o ajuste do modelo de regressão linear robusta, assim como a análise das ponderações das observações, são medidas de detecção de pontos aberrantes eficientes. Foram aplicados os critérios e medidas analisados ao conjunto de dados obtido da Estação Meteorológica do Instituto de Astronomia, Geofísica e Ciências Atmosféricas da Universidade de São Paulo para detectar quais variáveis meteorológicas influem na temperatura mínima diária durante o ano completo, e ajustou-se um modelo que permite identificar os dias associados à entrada de sistemas frontais. / Robust Regression arises as an alternative to least squares method when errors are contaminated by outliers points or there are some evidence of violation of model assumptions. In classical regression there are several criteria for model selection and diagnostic measures that are well known. The objective of this work is to present the main robust criteria of model selection and outliers detection measures, as well as to analyze and compare their performance according to different stages to determine which of them fit better in certain situations. The cross-validation criteria using Monte Carlo simulations and Beyesian Information Criterion are known to be adequately developed in model identification. This fact was confirmed, and in addition, its robust alternatives also stand out in this aspect. The residual analysis is a strong tool for model diagnostic analysis, in this work it was detected that the classic residual analysis on the robust linear model regression fit, as well as the analysis of the observations weights, are efficient measures of outliers detection points. The analyzed criteria and measures were applied to the data set obtained from the Meteorological Station of the Astronomy, Geophysics and Atmospheric Sciences Institute of São Paulo University to detect which meteorological variables influence the daily minimum temperature during the whole year, and was fitted a model that allows identify the days associated with the entry of frontal systems.
146

Matéria orgânica e a sorção de herbicidas em solos sob plantio direto nas regiões tropical e subtropical do Brasil / Organic matter and herbicides sorption in soils under no-tillage in tropical and subtropical regions of Brazil

Eloana Janice Bonfleur 27 June 2014 (has links)
O sistema de plantio direto (SPD) é extensivamente utilizado no Brasil por tratar-se de prática conservacionista, capaz de melhorar a qualidade do solo e diminuir os custos da produção em relação ao plantio convencional. Neste sistema as condições edafoclimáticas distintas e a adoção de diferentes culturas na entressafra sugerem diferenças na distribuição e na qualidade da matéria orgânica de solos (MOS), devido ao tempo de resiliência da palha em cobertura. A interação entre a MOS e os pesticidas já foi bastante estudada, mas apenas parcialmente esclarecida uma vez que a maioria dos estudos considera a MOS como um compartimento homogêneo, ignorando o papel de seus diferentes componentes moleculares. Assim sendo, o objetivo principal deste trabalho é avaliar o efeito da composição, distribuição e interação com a fase mineral da MOS na sorção de herbicidas aplicados às culturas de soja e milho, sob sistema plantio direto em diferentes condições edafoclimáticas: tropical (Região Centro-Oeste) e subtropical (Região Sul). Os herbicidas alaclor, bentazon e imazetapir foram selecionados devido às suas importâncias junto a essas culturas e suas propriedades físico-químicas distintas. Para tal, soram amostrados 12 Latossolos, na camada de 0 a 5 cm excluindo a palha de superfície, sendo seis representativos do Estado do Paraná (clima subtropical) e seis representativos do Estado do Mato Grosso do Sul (clima tropical). A determinação dos atributos físico e químicos, formas de ferro e alumínio, estudo da qualidade da MOS por espectroscopia de Ressonância Nuclear Magnética do 13C e fracionamento físico dos solos foram os métodos utilizados. Foi observado maior acúmulo de carbono orgânico (C.O) nos solos subtropicais devido ao maior teor de óxidos de alumínio de baixa cristalinindade, além da maior precipitação. Para os solos de ambas as regiões, a estabilização da MOS ocorre através da formação de complexos nos agregados tamanho argila ( ~ 50% do teor de C.O). Em relação às interações com a fase mineral, observou-se que os óxidos de alumínio estão relacionados à proteção física da MOS enquanto que os óxidos de ferro parecem participar das reações de decomposição e humificação através da formação de complexos com grupos carboxílicos. Para o alaclor, a presença de formas de alumínio de baixa cristalinidade diminuiu a sua sorção a MOS, entretanto a sorção deste herbicida não foi correlacionada a nenhum grupo funcional. Para o bentazon, foi observada correlação positiva entre a sorção e materiais orgânicos mais decompostos e também, com o alumínio complexado a MOS. Para o imazetapir, houve correlações positivas com as formas de ferro e alumínio e o grupo funcional carboxil. Para os três herbicidas a maior sorção foi observada nos agregados de tamanho silte (53 a 2 ?m) e, de maneira geral, a sorção nos solos tropicais foi maior que nos subtropicais. O efeito da exposição de sítios de carga após o fracionamento físico dos solos foi evidente para o imazetapir incrementando sua sorção em comparação a sorção no solo inteiro o que evidencia a maior quantidade de sítios bloqueados nos solos tropicais. / No-tillage System (NT) is widely used in Brazil due to improve soil quality and reduce production costs compared to conventional tillage. Different climatic conditions and the adoption of different cultures in the offseason suggest differences in the distribution and quality of soil organic matter (SOM) due to the resilience time of straw in coverage in NT. Interactions between SOM and pesticides has been widely studied, but only partially elucidated. In most of studies, the MOS as a homogeneous compartment and there is not the knowledge about the role of its various molecular components. Therefore, the aim of this work is to evaluate the effect of the composition, distribution and interaction with the mineral phase of SOM on sorption of herbicides applied to soybean and corn under no-tillage in tropical (Central-west) and subtropical (South Region) soils. Alachlor, bentazon and imazethapyr herbicides were selected because of its large use in these cultures and different physicochemical properties. For this, it was sampled 12 soils at 0-5 cm layer excluding the straw surface, six representing the Paraná State (subtropical) and six representative of Mato Grosso de Sul State (tropical). Physical and chemical attributes, iron and aluminum forms, study of quality of SOM by Nuclear Magnetic Resonance Spectroscopy of 13C and soil physical fractionation methods were used for this purpose. Greater accumulation of organic carbon (OC) was observed in subtropical soils due to higher low crystalline aluminum oxides contents, in addition to lower temperatures and higher moisture in this region. For soils of both regions, the SOM stabilization occurs through the formation of complexes in the clay fraction (~ 50 % of the OC content). Regarding interactions with the mineral phase, it was observed that aluminum oxides are related to physical protection of SOM while iron oxides appear to participate in the decomposition and humification reactions by forming complexes with carboxylic groups. For alachlor, low crystallinity aluminum forms decreased its MOS sorption but sorption of this herbicide was not correlated with any functional group. For bentazon, positive correlation was observed between sorption and more decomposed organic material and with the complexed aluminum in MOS. For imazethapyr, there were positive correlations with iron and aluminum forms and carboxyl functional group. For the three herbicides better sorption was observed in the silt size fractions (53-2 ?m) and in general, sorption in tropical was higher than in subtropical soils. The effect of charge sites exposure after soil physical fractionation was evident for imazethapyr increasing its sorption compared to the whole soil which shows the greatest amount of blocked sites in tropical soils.
147

Caractérisation Spectrale et Temporelle par Quenching de Fluorescence des Interactions Matière Organique-Eléments Métalliques / Spectral and Temporal Characterization of Organic Matter–Metal Elements by Fluorescence Quenching

Nouhi, Ayoub 13 December 2017 (has links)
L’étude du comportement des éléments métalliques est primordiale compte tenu leur effet souvent toxique dansde nombreux écosystèmes. Ces derniers lorsqu’ils interagissent avec la Matiere Organique (MO), peuvent formerdes complexes plus ou moins stables. Ainsi, la MO joue un rôle important dans leur spéciation chimique et leurtransport. Dans ce travail, l’analyse de cette complexation est réalisée par Quenching de Fluorescence (QF).Cette technique permet de modéliser la fixation des sites de complexation à l’aide d’une constante thermodynamiquedéterminée à partir d’un modèle 1 : 1. Le quenching de fluorescence a été mesuré par spectroscopie defluorescence en mode stationnaire et en mode résolue en temps. Les mesures de fluorescence en mode stationnairefournissent des Matrices d’Excitation et d’Émission de Fluorescence (MEEFs). L’extraction des différents composantsde ces MEEFs est effectué par séparation de sources : la décomposition multilinéaire CP/PARAFAC,qui permet de caractériser spectralement les composants. Les mesures par Spectroscopie Laser Résolue en Temps(SLRT) permettent une caractérisation spectrale et temporelle des composants fluorescents. L’étude des lois dedécroissance de la fluorescence induite par impulsion laser nanoseconde en l’occurrence a permis de déterminerle type d’interaction entre la MO et les quencheurs. Pour se faire, un algorithme de déconvolution temporellea été appliqué à chaque décroissance de fluorescence mesurée. L’interprétation des données temporelles a étéaccomplie en utilisant le graphique de Stern–Volmer. Les résultats des interactions du cuivre, de l’europiumet de l’uranium avec les Acides Humiques (AH) et les Acides Fulviques (AF) montrent des décroissances defluorescences importantes et des constantes de stabilité entre 2,04 et 4,52. Le cuivre a permis de valider notremodèle d’étude et l’interaction de l’europium et l’uranium avec les AH et AF étudiés a révélé des constantesde stabilité en général en bonne corrélation avec la littérature. Les résultats de la SLRT ont souvent révélé desdécroissances bi–exponentielles et des temps de vie entre 0,40 et 14 ns et montrent que les interactions étudiéesont principalement engendrer un quenching statique et donc la formation d’un complexe moléculaire à l’étatfondamental. Cette étude a donc permis par caractérisation spectrale et temporelle, de déterminer l’interactionde la matière organique avec les métaux plus ou moins toxiques. / The study of metal elements behavior, considering their impact in various ecosystems, is of paramount importance.The latter, upon contact with Organic Matter (OM) can form weak or strong stable complexes. Therefore,OM plays an important role in their chemical speciation and transport. The analysis of these properties is carriedout by Fluorescence Quenching (QF). This technique allows introspecting ligands–metal interactions andthe 1 : 1 modeling (one ligand site, one metal) gives information about the conditional thermodynamic constant.Fluorescence quenching was measured using steady–state and time–resolved fluorescence spectroscopy.The steady–state measurements provides Excitation and Emission Matrices of fluorescence (EEMs). The extractionof the different components from these matrices is carried out by a multi–mode factor analysis such asCP/PARAFAC, which allows a spectral composition of the samples. Time-Resolved Laser Spectroscopy (TRLS)measurements allow temporal and spectral characterization of the fluorescent components. Indeed, the study ofthe fluorescence decays induced by a nanosecond pulsed laser in this case allowed to measure the interaction betweenthe OM and the quencher. For those purposes, a fluorescence lifetime deconvolution algorithm was appliedto each fluorescence decay. Analysis of the fluorescence lifetime data was accomplished using the Stern–Volmerplot which gave reliable information on the quenching process that takes place. Copper, europium and uraniuminteractions with Humic Acids (HA) and Fulvic Acids (FA) shows significant fluorescence decays and stabilityconstants between 2.04 and 4.52. Copper allowed to calibrate our model study and the interactions of europiumand uranium with the HA and FA studied reported stability constants in agreement with the literature. TRLSresults have often revealed a bi–exponential decays and fluorescence lifetimes between 0.40 and 14 ns and showsthat the studied interactions mainly lead to static quenching and thus the formation of a molecular complex inthe ground state. This study has allowed spectral and temporal characterization to determine organic matterinteraction with toxic metals.
148

Search for CP violation in four-body fully charged b-baryon decays with the LHCb spectrometer / Recherche d'une violation CP avec le spectromètre LHCb

Maratas, Jan Mickelle 06 November 2015 (has links)
Résumé indisponible. / Résumé indisponible.
149

Direct CP violation in B decays including \rho - \omega mixing and covariant light-front dynamics

Leitner, Olivier Michel André 04 July 2003 (has links) (PDF)
NIL
150

Interaktion hos yngre barn med grav cerebral pares : En fallstudie av interaktionen hos två yngre barn och deras närmaste omgivning med ett strukturerat bedömningsmaterial

Sjöblom, Evelina, Johannisson, Josefina January 2014 (has links)
Kommunikation är avgörande för att uppnå en god livskvalitet och grundläggande för att kunna förstå andra och göra oss själva förstådda. Grunden för en tillfredsställande kommunikation är att det finns ett samspel mellan de parter som ingår, vilket förutsätter att det sker ett ömsesidigt utbyte mellan samtalsparterna. De funktionsnedsättningar som cerebral pares ofta leder till kan medföra svårigheter för individen att göra sig förstådd. Det saknas idag svenska studier gällande interaktionen hos små barn med grav cerebral pares (CP). Denna studies syfte är att bidra till en ökad kunskap om hur interaktionen ser ut hos yngre barn (1,5-5 år) med grav CP (GMFCS IV-V) och deras närmaste omgivning. Studien är en kombinerad kvantitativ och kvalitativ fallstudie med fokus på strukturella bidrag och pragmatiska funktioner i den gemensamma interaktionen mellan två barn med grav CP och deras kommunikationspartners på respektive barns förskola. Barnen filmades i olika vardagliga aktiviteter och därefter transkriberades filmerna, innan de analyserades med ett strukturerat bedömningsmaterial och med beskrivande statistik. De frågeställningar som undersöktes i studien var: Vilka typer av kommunikativa bidrag använder yngre barn med grav cerebral pares i interaktionen med sin närmaste omgivning? Vilka typer av kommunikativa bidrag använder omgivningen i interaktionen med yngre barn med grav cerebral pares? Skiljer sig barnens sätt att delta åt mellan olika vardagliga aktiviteter? Går det att besvara ovanstående frågeställningar med det bedömningsmaterial som utvecklats och översatts av Paulsson 2011? Resultaten av analysen indikerade att fokusbarnen hade en passiv roll i samtalet och främst producerade responser, medan kommunikationspartnern var mer aktiv och tog fler initiativ. Resultaten går därmed i linje med tidigare studiers resultat, från andra länder och med äldre barn. Bedömningsmaterialet går att använda på målgruppen och kan identifiera mönster och skillnader i kommunikationen hos dessa yngre barn. Materialet kräver dock vidare bearbetning för att säkerställa validiteten i resultaten. Ett mer utvecklat material kan tänkas ligga till grund för framtida forskningsstudier av denna målgrupp samt för att skapa underlag för evidensbaserade logopediska insatser. / Communication is crucial to achieve a good quality of life, and it’s also a vital skill to be able to understand others and to make ourselves understood. The basis of a satisfactory communication is that there is an interaction between all parties involved. This requires that there is a mutual exchange between the conversational partners. Disabilities commonly associated with cerebral palsy often lead to difficulties in the individual’s ability to make him- or herself understood. Today there is a lack of Swedish studies investigating how young children with cerebral palsy (CP) interact. The aim of this study/master thesis is to contribute towards a better understanding of how young children (1,5-5 years old) with severe cerebral palsy (GMFCS IV-V) interact with their immediate surroundings. This thesis is a combined qualitative and quantitative case study focusing on turns and communicative functions in the joint interaction of two children with severe cerebral palsy and their communication partners in each child's preschool. Both children were filmed in various everyday activities and subsequently the films were transcribed before being analyzed with a structured assessment material and presented with descriptive statistics. The issues addressed in this study are: What kind of communicative contributions do young children with severe cerebral palsy use in their interaction with their communication partners? What kind of communicative contributions are used by the communication partners when they interact with young children with severe cerebral palsy? Do the way in which children interact vary between various everyday activities? Is it possible to use the assessment material that was developed and translated by Paulsson 2011 to try to answer the questions above? The result of this study indicated that the children in this study used a passive way of communicating. They mainly produced responses, while their communication partners were more active and made more initiations. The results are thus consistent with the results of previous studies from other countries and with older children. The findings indicate that the material can be used to identify patterns and differences in the communication even for younger children, but it requires further adaptations to ensure the validity of the result. A further developed assessment material may form the basis for future research studies of this target group and may create a basis for evidence-based speech- and language pathology interventions.

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