Dissertations / Theses on the topic 'Radical quantification'

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Resveratrol (cis and trans) and quercetin are important components in ensuring the quality of wine because of the diversity of biological activities that they have. Studies quantifying these constituents in Brazilian wines are rarely reported in the literature, especially in wines from the Vale Submédio do São Francisco. The objectives of this work were to develop and validate a quantification method for cis-resveratrol, trans-resveratrol, total resveratrol and quercetin by HPLC-UV in red wines, to evaluate and correlate the levels of total phenolics by Folin-Ciocalteu method with the anti-radical activity determined usingm the DPPH radical method and to determine the potential for classification of wines from their chromatographic profiles. In the study 45 samples of red wines were analysed. From these, 30 samples were from Brazilian wines:15 of the Vale Submédio do São Francisco, 11 of Serra Gaucha and 4 of Campanha Gaucha. There were 15 samples of imported wines: 5 from Argentina, 5 from Chile and 5 from French. The method developed for quantification of resveratrol (cis and trans) and quercetin was validated andused in the quantification. The results showed that Brazilian wines have about nine times more cis-resveratrol than trans-resveratrol and this relationship is even more pronounced in the Vale do São Francisco, with about 17 times more cis-resveratrol than trans-resveratrol in red wines from this region. The French wines presented quercetin in an amount above the rest of the wine samples. It was also observed that the wines from the Vale do São Francisco had higher levels of total resveratrol, significantly higher than imported wines, with p=0.0381. The total phenolics content was markedly higher in the wines from the Vale do São Francisco in relation to wines from the South, with p=0.001. The study of anti-radical activity against the DPPH radical showed that all wines are active, with EC50<130 μg/mL. In the study of the chromatographic profiles of the wines four distinct groupings among the wines were found, with 87% of the samples from the Vale do São Francisco, 80% of Chileans wines, 60% of the Serra Gaucha wines and 55% of French wines. Taken toghether the results show that Brazilian wines presented high level of phenolics, especially the wines from Vale do Submédio do São Francisco. This is translated into high levels of bioactive substances such as resveratrol (cis and trans) and quercetin, as well the high antioxidant activity. The high intensity of solar light in Brazil, mainly in the Vale do São Francisco, may have been the main factor contributing to the high content of these constituents, thus contributing to the high degree of grouping shown by the wines of this region using multivariate analysis.
O resveratrol (cis e trans) e quercetina são componentes de grande importância na garantia da qualidade do vinho, devido à diversidade de atividades biológicas que eles possuem. Estudos de quantificação destes constituintes em vinhos brasileiros são pouco relatados na literatura, especialmente nos vinhos do Vale Submédio do São Francisco. Os objetivos deste trabalho foram desenvolver e validar um método de quantificação do cis-resveratrol, trans-resveratrol, resveratrol total e quercetina por CLAE-UV/Vis em vinhos tintos, avaliar e correlacionar os teores de fenólicos totais pelo método de Folin-Ciocalteu com a atividade anti-radicalar, frente ao radical DPPH e determinar o potencial de classificação dos vinhos a partir dos perfis cromatográficos. Para execução do trabalho foram analisadas 45 amostras de vinhos tintos, sendo 30 brasileiros das regiões do Vale Submédio do São Francisco (15), Serra Gaúcha (11) e Campanha Gaúcha (4), e 15 importados: argentinos (5), chilenos (5) e franceses (5). O método desenvolvido para quantificação de resveratrol isômeros (cis e trans) e quercetina apresentou dados e características suficientemente bons para ser validado e utilizado no processo de quantificação. Os resultados obtidos demonstraram que os vinhos brasileiros possuem cerca de 9 vezes mais cis-resveratrol que trans-resveratrol, esta relação é ainda mais pronunciada na região do Vale Submédio do São Francisco, sendo cerca de 17 vezes mais cis do que trans. Os vinhos franceses apresentaram quercetina em quantidade superior ao restante dos conjuntos amostrais de vinhos. Foi observado também que os vinhos do Vale Submédio do São Francisco possuem teores de resveratrol total, significativamente superiores aos vinhos importados, com p=0,0381. O teor de fenólicos totais foi marcadamente superior nos vinhos do Vale Submédio do São Francisco em relação aos vinhos da região Sul, com p=0,001. O estudo de atividade anti-radicalar frente ao radical DPPH demonstrou que todos os vinhos são ativos, com CE50 <130 μg/mL. No estudo do perfil cromatográfico dos vinhos foram determinados quatro agrupamentos distintos, sendo 87 % entre os vinhos do Vale Submédio do São Francisco, 80 % entre os chilenos, 60 % entre os da Serra Gaúcha e 55 % entre os vinhos franceses. Os estudos realizados com os vinhos revelaram resultados que posicionam os vinhos brasileiros, especialmente os vinhos da região do Vale Submédio do São Francisco, em um elevado patamar em termos de qualidade. Isto é corroborado pelos elevados teores de substâncias bioativas tais como o resveratrol (isômeros cis e trans) e quercetina, bem como o elevado teor de fenólicos totais e alta atividade anti-radicalar. A alta intensidade de insolação no Brasil, principalmente na região do Vale Submédio do São Francisco, pode ter sido o principal fator a contribuir para elevação do teor destes constituintes, contribuindo, desta forma, para um elevado grau de agrupamento dos vinhos desta região por análise multivariada.

Cette étude a pour but d’explorer l’influence du nanoconfinement sur le comportement de substrats organiques incorporés dans des silices mésoporeuses. Ces travaux s’articulent en deux volets. Le premier est une étude sur l’efficacité de la réaction de fragmentation par voie photochimique ou thermique d’alcoxyamines confinées. Par comparaison avec une étude réalisée en solution, des mesures effectuées par spectroscopie RPE quantitative ont permis de montrer que l’efficacité de cette rupture n’est pas altérée par l’incorporation des précurseurs organiques dans une matrice de silice. Dans un second temps des matériaux hybrides organiques-inorganiques fonctionnalisés par des précurseurs diazèniques ont été synthétisés. Ces derniers sont capables, sous irradiation à 360 nm, de former des radicaux hétéroatomiques qui sont transitoires en solution mais persistants dans la silice. Différentes structures ont été synthétisées, notamment des matériaux fonctionnalisés par une paire de radicaux de nature différente, i.e. un radical aryloxyle disposé face à un radical arylsulfanyle. Des études RPE en onde continue et pulsée ont permis de mettre en évidence la grande durée de vie de ces espèces paramagnétiques confinées et de mesurer leurs temps de relaxation
The aim of this work was to investigate the influence of the nanocofinement on the behaviour of organic substrates embedded in mesoporous silicas. This research hinged on two parts. The first study focused on the efficiency of the fragmentation reaction of confined alkoxyamines, under thermal or photochemical activation. Thanks to the comparison with the very same reactions in solution, the quantitative EPR measurements showed that the confinement of organic precursors had no effect on the efficiency of these reactions. Secondly, organic-inorganic hybrid materials were synthesized. These mesoporous silicas were functionalized with diazene radical precursors. Upon 360 nm irradiation, they generated heteroatomic radicals. Different materials were prepared, including one which enabled to form a face-to-face pair of different radicals, i.e. an aryloxyl radical in front of an arylsulfanyl radical. Studies carried out by continuous and pulsed wave EPR enabled to highlight the high stability of these confined paramagnetic species and to measure their relaxation times

Afin d’améliorer les traitements par radiothérapie, des radiosensibilisateurs tels que les nanoparticules d’or (NPo) sont étudiés. Mais leur translation en clinique nécessite une bonne compréhension des phénomènes en jeu. Si l’effet radiosensibilisateur a bien été confirmé sur des cibles biologiques (ADN, cellules et in vivo) et si les radicaux hydroxyle ont souvent été proposés comme intermédiaires, aucune preuve claire n’a encore été apportée. Ce travail avait pour premier objectif d’élaborer un protocole de « référence » afin de quantifier les radicaux hydroxyle et les électrons produits par les NPo en interaction avec un rayonnement ionisant. Cette étude a mis en évidence des productions massives de ces deux espèces pour des NPo non-fonctionnalisées. De plus, l'étude de différents paramètres, tels que la quantité de dioxygène en solution ou le rayonnement incident, nous a conduits à proposer un nouveau mécanisme permettant de rendre compte de nos résultats. Néanmoins, l'application biologique des NPo ne peut être envisagée que si ces nano-objets sont fonctionnalisés afin de les rendre furtifs et de les adresser spécifiquement à la tumeur. Après synthèse et caractérisation poussée de différents types de NPo fonctionnalisées, nous avons comparé la production de radicaux hydroxyle avec la dégradation d’une cible biologique, l'ADN, et mis en évidence l'impact significatif de la fonctionnalisation sur l'effet radiosensibilisateur. Ainsi, cette étude apporte des informations essentielles en vue de l’optimisation de la conception des NPo les plus efficaces pour la radiosensibilisation, une première étape vers leur application radiothérapeutique
To improve radiotherapy efficiency, radiosensitizers such as gold nanoparticles (GNP) are developed. But to translate them to clinics, a good knowledge of the processes at stage is needed. GNP radiosensitizing effect was well-confirmed on biological targets (DNA, cells and in vivo) and hydroxyl radicals are often proposed to be key intermediates, but no clear evidence has been given yet. In this work, we first developed a ‘reference’ protocol to quantify hydroxyl radicals and electrons produced by GNP in their interaction with ionizing radiation. These investigations reveal a massive production of both species for non-functionalized GNP. Moreover the study of various parameters such as the concentration of dissolved dioxygen or the energy of the incident radiation leads us to propose a new mechanism on the origin of the radiosensitizing effect. Nevertheless, biological applications of GNP can only be considered if the nano-objects are functionalized to make them furtive, address them or deliver medicines to the tumor. After synthesis and characterization of different functionalized GNP, we compared hydroxyl radicals production with the damages induced on DNA and highlighted a significant impact of functionalization on the radiosensitizing effect. Finally, this work gives valuable information for the design of the most efficient GNP for radiotherapy which is a first step towards their medical application

Cette thèse évolue selon trois axes de recherche. La première partie présente des travaux de spectroscopie TéraHertz (THz) de COV réalisés à l'aide du spectromètre THz par technique de photomélange, ce dernier rendant accessible la région spectrale 0,3-3 THz à haute résolution. Ces travaux concernent l'amélioration de paramètres moléculaires du formaldéhyde (H₂CO) obtenue grâce à la mise en oeuvre d'un système de métrologie performant reposant sur l'utilisation d'un peigne de fréquence. La très haute résolution de ce spectromètre a également permis un travail de collaboration efficace avec différents laboratoires concernant la détermination de coefficients d'élargissement du chlorure de méthyle (CH₃Cl). La deuxième partie montre la possibilité de détection de radicaux légers par technique de photomélange au travers d'études concernant les radicuax hybroxyle (OH) et mercaptan (SH). La très haute résolution de notre spectromètre donne accès à leur structure hyperfine avec des précision encore inégalées dans la région 1-3 THz. Cette partie illustre également l'intérêt de notre collaboration avec la ligne AILES du synchrotron SOLEIL et démontre la grande complémentarité entre le spectromètre photo-mélange et l'interféromètre couplée au rayonnement synchrotron. La dernière partie présente l'initiation au sein du groupe THz d'une étude cinétique effectuée grâce à une chaîne par multiplication de fréquence. Cette étude concerne concerne la photolyse de H₂CO. S'ajoute à ceci une étude visant à caractériser le rayonnement THz en présence d'aérosols de chlorure de sodium hydratés.

L'argomento principale della tesi è l'applicazione delle tecniche di quantificazione dell'incertezza (UQ) alla simulazione numerica (CFD) di turbine radiali twin entry impiegate nella turbosovralimentazione automobilistica. Lo studio approfondito di questo tipo di turbomacchine è affrontato nel capitolo 3, finalizzato alla comprensione dei principali parametri che caratterizzano e influenzano le prestazioni fluidodinamiche delle turbine twin scroll. Il capitolo 4 tratta di una piattaforma per l'analisi UQ sviluppata internamente tramite il set di strumenti open source ‘Dakota’. La piattaforma è stata testata dapprima su un caso di interesse industriale, ovvero un ugello de Laval supersonico (capitolo 5); l'analisi ha evidenziato l'utilizzo pratico delle tecniche di quantificazione dell'incertezza nella previsione delle prestazioni di un ugello affetto da condizioni di fuori progetto con complessità fluidodinamica dovuta alla forte non linearità. L'esperienza maturata con l'approccio UQ ha agevolato l'identificazione di metodi idonei per applicare la propagazione dell’incertezza alla simulazione CFD di turbine radiali twin scroll (capitolo 6). In tal caso sono state studiate e messe in pratica diverse tecniche di quantificazione dell'incertezza al fine di acquisire un'esperienza approfondita sull’attuale stato dell'arte. Il confronto dei risultati ottenuti dai diversi approcci e la discussione dei pro e dei contro relativi a ciascuna tecnica hanno portato a conclusioni interessanti, che vengono proposte come linee guida per future applicazioni di quantificazione dell’incertezza alla simulazione CFD delle turbine radiali. L'integrazione di modelli e metodologie UQ, oggi utilizzati solo da alcuni centri di ricerca accademica, con solutori CFD commerciali consolidati ha permesso di raggiungere l'obiettivo finale della tesi di dottorato: dimostrare all'industria l'elevato potenziale delle tecniche UQ nel migliorare, attraverso distribuzioni di probabilità, la previsione delle prestazioni relative ad un componente soggetto a diverse fonti di incertezza. Lo scopo dell’attività di ricerca consiste pertanto nel fornire ai progettisti dati prestazionali associati a margini di incertezza che consentano di correlare meglio simulazione e applicazione reale. Per accordi di riservatezza, i parametri geometrici relativi alla turbina twin entry in oggetto sono forniti adimensionali, i dati sensibili sugli assi dei grafici sono stati omessi e nelle figure si è reso necessario eliminare le legende dei contours ed ogni eventuale riferimento dimensionale.
The main topic of the thesis is the application of uncertainty quantification (UQ) techniques to the numerical simulation (CFD) of twin entry radial turbines used in automotive turbocharging. The detailed study of this type of turbomachinery is addressed in chapter 3, aimed at understanding the main parameters which characterize and influence the fluid dynamic performance of twin scroll turbines. Chapter 4 deals with the development of an in-house platform for UQ analysis through ‘Dakota’ open source toolset. The platform was first tested on a test case of industrial interest, i.e. a supersonic de Laval nozzle (chapter 5); the analysis highlighted the practical use of uncertainty quantification techniques in predicting the performance of a nozzle affected by off-design conditions with fluid dynamic complexity due to strong non-linearity. The experience gained with the UQ approach facilitated the identification of suitable methods for applying the uncertainty propagation to the CFD simulation of twin entry radial turbines (chapter 6). In this case different uncertainty quantification techniques have been investigated and put into practice in order to acquire in-depth experience on the current state of the art. The comparison of the results coming from the different approaches and the discussion of the pros and cons related to each technique led to interesting conclusions, which are proposed as guidelines for future uncertainty quantification applications to the CFD simulation of radial turbines. The integration of UQ models and methodologies, today used only by some academic research centers, with well established commercial CFD solvers allowed to achieve the final goal of the doctoral thesis: to demonstrate to industry the high potential of UQ techniques in improving, through probability distributions, the prediction of the performance relating to a component subject to different sources of uncertainty. The purpose of the research activity is therefore to provide designers with performance data associated with margins of uncertainty that allow to better correlate simulation and real application. Due to confidentiality agreements, geometrical parameters concerning the studied twin entry radial turbine are provided dimensionless, confidential data on axes of graphs are omitted and legends of the contours as well as any dimensional reference have been shadowed.

This research investigated the radial-inflow turbo-expander, the conical diffuser, and the annular-radial diffuser using high-density working fluid in typical renewable energy power system. This study highlights the need to achieve a high performance of a whole radial-inflow turbine including a radial-inflow turbo-expander and a new designed annular-radial diffuser in order to improve overall energy conversion efficiency, which is critical to further development of renewable power solutions.

Les radicaux libres sont capables de réagir avec pratiquement toutes les familles de molécules présentes dans les systèmes biologiques. Ainsi les radicaux libres réagissent en particulier sur l'ADN, induisant des mutations qui conduisent au développement de cancer. De même les radicaux libres réagissent avec les lipides, produisant des phénomènes inflammatoires qui peuvent entraîner le développement de maladies cardiovasculaires. La Résonance Paramagnétique Électronique est la technique classique pour l'identification et la quantification des radicaux libres. Pour la plupart des radicaux en solution une étape de piégeage du radical pour former une espèce radicalaire à longue durée de vie est indispensable. Les milieux réactionnels sièges de réaction d'oxydoréduction conduisent à une transformation de ces adduits en espèces non radicalaires qui ne sont plus détectables par Résonance paramagnétique Électronique. De plus l'identification des radicaux est difficile dans le cas de mélange complexes
Nous avons développé une nouvelle méthode de détection et de quantification des radicaux libres basée sur la spectrométrie de masse en utilisant l'ionisation par électronébulisation. Nous avons tout d'abord testé les principales familles de piégeurs de radicaux en spectrométrie de masse. Nous en avons optimisé les conditions d'analyse par spectrométrie de masse pour une nitrone, la 2,2,5-triméthyl-3-phényl-3,4-dihydro-2H-pyrrole-l-oxyde (TMPO), spécifique des radicaux centrés sur les hétéroélements et pour un nitroxyde, le 3-amino-2,2,5,5-tetraméthyl-pyrrolidinyloxy (AMP), spécifique des radicaux C-centrés. Nous avons constitué une bibliothèque MS/MS des différents types de radicaux libres permettant leur identification dans des mélanges complexes. Nous avons ensuite appliqué cette méthodologie pour identifier et quantifier les radicaux libres présents dans les fumées de cigarette. La quantité globale de radicaux est de l'ordre de 2. 10+17 radicaux par cigarette fumée en accord avec les études antérieures. Nous avons identifié et quantifié de nombreux radicaux originaux dans la fumée de cigarette comme les radicaux hydroxyle (OH), cyanogène (CN) et méthyle (CH3). Cette étude a également permis de déboucher sur des recherches d'optimisation de filtres permettant la diminution de la teneur en substance radicalaire de la fumée de cigarette. Nos résultats ont montré de plus que les différentes familles de radicaux présentes dans la fumée de cigarette sont éliminés avec des efficacités variables

L'hépatotoxicité alcoolique met en jeu les produits du métabolisme de l'éthanol par le cytochrome P450 2E1 (CYP2E1) tels que l'acétaldéhyde (oxydation bi-électronique) et les radicaux hydroxyéthyles (HER) (oxydation mono-électronique). Le CYP2E1 est le principal site d'oxydation micromal de l'éthanol (84% chez le rat, 30% chez l'Homme). L'oxydation produit de l'acétaldéhyde et des HER dans le rapport 9/1. La voie mono-électronique représente 5 à 7 %. L'incubation de guanine avec des HER produits in situ entraîne la formation d'adduits HER-guanine (HEG) (12% de la guanine). Les adduits HEG n'ont pas pu être détectés au niveau de l'Adn de patients alcooliques, d'hépatocytes en culture traotés à l'alcool, ni d'ADN incubé avec des microsomes et de l'alcool. L'étude de l'alkylation des protéines microsomales montre que les adduits HER se forment principalement avec le CYP2E1. Néanmoins, la formation d'HER-CYP2E1 n'affecte pas son activité catalytique sous des conditions normales
Hepatotoxicity of alcoholic intoxication brings into play the products resulting from the metabolism of ethanol by the cytochrome P4502E1 (CYP2E1): acetaldehyde (two-electron oxidation), and hydroxyethyl radicals (HER) (one electron-oxidation). This products can form adducts with surrounding molecules. CYP2E1 is the principal site of oxidation microsomal of ethanol (84% in the rat, only 30% in the Man ). Ethanol oxidation leads to the formation of acetaldehyde and HER in the 9/1 ratio. The contribution of the mono-electronics pathway, revealed by spin-trapping method of HER, accounts for 5 to 7 %. Incubation of guanine with HER formed in situ results in HER-guanine adducts (HEG) (12% of incubated guanine). However, HEG adducts could not be detected either in DNA from several biological materiels. Alkylation of the microsomals proteins shows that adduits HER are formed mainly with the CYP2E1. The formation of HER-CYP2E1 does not affect the catalytic activity under normal conditions

This degree project focused on examining new possible application of near-infrared (NIR) spectroscopy for quantitative and qualitative characterization of refuse derived fuel (RDF). Particularly, two possible applications were examined as part of the project. Firstly, use of NIR hyperspectral imaging for classification of common materials present in RDF. The classification was studied on artificial mixtures of materials commonly present in municipal solid waste and RDF. Data from hyperspectral camera was used as an input for machine learning models to train them, validate them, and test them. Three classification machine learning models were used in the project; partial least-square discriminant analysis (PLS-DA), support vector machine (SVM), and radial basis neural network (RBNN). Best results for classifying the materials into 11 distinct classes were reached for SVM (accuracy 94%), even though its high computational cost makes it not very suitable for real-time deployment. Second best result was reached for RBNN (91%) and the lowest accuracy was recorded for PLS-DA model (88%). On the other hand, the PLS-DA model was the fastest, being 10 times faster than the RBNN and 100 times faster than the SVM. NIR spectroscopy was concluded as a suitable method for identification of most common materials in RDF mix, except for incombustible materials like glass, metals, or ceramics. The second part of the project uncovered a potential in using NIR spectroscopy for identification of inorganic chlorine content in RDF. Experiments were performed on samples of textile impregnated with a water solution of kitchen salt representing NaCl as inorganic chlorine source. Results showed that contents of 0.2-1 wt.% of salt can be identified in absorbance spectra of the samples. Limitation appeared to be water content of the examined samples, as with too large amount of water in the sample, the influence of salt on NIR absorbance spectrum of water was too small to be recognized.
FUDIPO

En contexte tempéré, les études sur l'instabilité spatio-temporelle de la sensibilité des essences forestières au climat sont rares et souvent conduites à des échelles locales et régionales ; de telles approches ne permettant pas d'obtenir une vision globale de la réponse à l'environnement et à ses variations. La fusion de jeux de données dendrochronologiques (plus de 4500 arbres carottés) a permis d'analyser le comportement de croissance de sept essences européennes tempérées majeures (Quercus petraea, Fagus sylvatica, Abies alba, Picea abies, Pinus sylvestris, Pinus nigra, Pinus uncinata) dans des contextes climatiques variés (océanique à subalpin) et sur l'ensemble du 20ème siècle. Ce travail a également permis de préciser dans quelles mesures les conditions écologiques locales modulaient cette sensibilité au climat. Les relations cerne-climat ont été évaluées par le calcul de fonctions de corrélation. Quelque soit l'essence et le contexte écologique, la sécheresse estivale est le principal facteur limitant la croissance radiale (mais non l'unique), suivie par la sécheresse de l'automne précédent et enfin le froid hivernal. La variabilité spatiale de la réponse dépend plus fortement de la pluviométrie que des températures, une pluviométrie faible conduisant à une sensibilité plus forte au froid hivernal et aux sécheresses estivale et automnale. Ce comportement général est modulé par les conditions écologiques locales, avec une sensibilité à la sécheresse moindre sur sol profond. Les différences interspécifiques s'expriment principalement hors saison de végétation (novembre à mars), même si les corrélations sont rarement significatives. La croissance des résineux est généralement stimulée par des fins d'hiver chauds (février à avril), alors que celle des feuillus est corrélée négativement aux températures et positivement aux précipitations en décembre et janvier. Ces différences entre essences s'avèrent plutôt stables le long des gradients climatiques. Enfin, l'analyse temporelle révèle de fortes instabilités des relations cerne-climat au cours du siècle dernier. Le sens et l'ampleur de ces variations sont homogènes le long des gradients écologiques, mais en revanche peu synchrones avec les instabilités climatiques (automne, hiver, printemps) ou écophysiologiquement peu logiques (été). Cette faible cohérence entre tendances climatiques et instabilité de la sensibilité au climat pourrait s'expliquer par l'absence d'une contrainte climatique de croissance unique en contexte tempéré, où la largeur de cerne est sous le double contrôle du froid hivernal et du stress hydrique estival (et automnal). Elle pourrait également provenir de phénomènes non climatiques, tels que l'effet biologique lié au vieillissement ou l'évolution progressive des pratiques de gestion forestière. Les analyses des variations spatio-temporelles de sensibilité au climat questionnent également sur la précision des relations cerne-climat, estimée le plus souvent au travers du calcul des fonctions de corrélation. En effet, les comparaisons inter-région, inter-site et inter-période des réponses révèlent souvent des variations de corrélations dont les grandeurs pourraient être de l'ordre de la précision liée à l'échantillon considéré. Nous proposons ici de quantifier l'effet de la taille (nombre d'arbres carottés) et des caractéristiques de l'échantillon (nombre de placettes, nombre d'arbres par placette, statuts sociaux couverts) sur la qualité de l'estimation du signal environnemental contenu dans la chronologie moyenne et des fonctions de corrélation. Cette analyse a permis également de préciser dans quelles mesures les différences (1) de traits fonctionnels entre espèces et (2) de contextes climatiques (plus ou moins limitants) modulent cet effet " échantillon ". [...] Suite et fin du résumé dans la thèse.

碩士
國立高雄第一科技大學
環境與安全衛生工程所
95
The study employs dimethyl sulfoxide (DMSO) as a radical capture for quantifying formation concentration of hydroxyl radicals (·OH) in liquid-phase TiO2-photocatalytic reaction systems. In this study, a trapper/fluoresce technique has been developed to monitor formation concentration of formaldehyde which is the major reaction intermediate from reacting DMSO with hydroxyl radicals. The initial formation rate of formaldehyde is applied to calculate yield rate of the hydroxyl radicals formed onTiO2 surfaces. Several affecting factors including solution pH level, TiO2 dosage, irradiated light intensity and different wavelength light sources have been tested to investigate the capability of applying the developed technique for determining photocatalyst photocatalytic activities in various operation conditions. Experimental results indicate that DMSO concentration should be higher than 4 mM for covering most part of active sites on TiO2 particles while TiO2 concentration equal to 0.01 g/L. Otherwise, underestimation of ·OH formation concentration will be observed. The results also show hydroxyl radicals concentration increases with pH level due to increasing reactions between hydroxyl ions (OH-) with electron holes. More formation of hydroxyl radicals are detected in higher illumination light intensity, too. For the effect of TiO2 dosage concentration on the radical formation, it is observed that the overall radical yield rate increases withTiO2 concentration initially and then approaches a flat maximal level as TiO2 concentration above 200 mg/L. But the radical yield rate is declining with TiO2 concentration if the rate is expressed by unit gram of TiO2, which results from receiving less irradiated light intensity by each TiO2 particle because TiO2 particle scatters each other in high-concentration conditions. Besides, the experimental results indicate a low yield rate of hydroxyl radicals by using 446-nm light sources. The radical yield rate by using 256-nm lamps is about 2.5 times higher than by using 365-nm lamps. Finally, according to the achieved relationships among hydroxyl radical yield rates and the experimental parameters, a semi-empirical model for predicting formation rate of hydroxyl radicals is proposed in this study based on the variables including proton concentration, TiO2 concentration and irradiated light intensity. The prediction model demonstrates well correlations between radical concentrations and photocatalytic reaction rates assisted by TiO2, which not only shows the developed radical measurement technique being a good indicator representing photocatalytic activities of photocatalysts, but also indicates the formation of hydroxyl radical is the key reaction mechanism for fast degradation of organic compounds.

碩士
國立中興大學
畜產學系
93
The purpose of this study was to evaluate the effect of transgenic rice phytase (TRP) supplement in diet on growth performance, hematological characteristics, tibia characters, phosphorus excretion of broilers and developed a radial enzyme diffusion method to determine phytase activity. The basal diets in the experiment were corn-soybean meal, control group diet of the grower (0-3 weeks) and the finisher (4-6 weeks) containing 0.45% and 0.40% non-phytate phosphorus (NPP). The low NPP group diet containing 0.35% and 0.30% NPP, respectively. The enzyme treatments were low NPP group diet added Peniophora lycii phytase (PLP) 750 U/kg or TRP 60, 90, 120, 150 and 600 U/kg. The results showed that during 0-3 weeks, the body weight, weight gain and feed intake increased linearly with the level of TRP (P<0.05). Both diets supplement TRP 150 and 600 U/kg had similar broiler performance with control and PLP groups. The feed efficiency of all treatments didn’t have significantly different. During 4-6 weeks, the body weight and weight gain were in all TRP supplement groups were significantly higher than low NPP group (P<0.05), but didn’t improve the feed intake and the feed efficiency. During 0-6 week, the growth performance in all TRP groups significantly improved the body weight and weight gain compared with the low NPP group, and TRP 60 U/kg supplementing group can improve chicken growth performance. The serum phosphorus of 3-week-old broiler, all TRP groups didn’t significantly different with low NPP group, but supplementing TRP 600 U/kg showed similar result with control and PLP groups. The serum calcium of the low NPP group has significantly lower than control group, and the creatinine significantly higher than other treatments (P<0.05). The other hematological characteristics didn’t significantly different with all treatments. On 6-week-old all hematological characteristics of all treatments didn’t significantly different. On 3-week-old, the tibia break strength, stress, concentration of ash and phosphorus were increased linearly with the level of TRP (P<0.05). On 6-week-old, the concentration of ash, calcium and phosphorus in tibia were increased linearly with the level of TRP (P<0.05). On 3-week-old all TRP treatments had depressed the rate of phosphorus excretion similar with PLP treatment, but the result showed TRP 600 U/kg significantly lower phosphorus excretion than low NPP group. On 6-week-old, all TRP treatments have the same phosphorus excretion with the low NPP group. The pathological diagnosis of all treatmeats didn’t have significantly different. A conclusion, TRP supplement in low NPP diet can improve NPP utilization and increase grower performance, then didn’t affect healthy of broilers. In addition, try to use radial enzyme diffusion method to measuring the phytase activities in pure enzyme and in feed. The principle is using phytate-Na substrate containing gel plate, substrate was hydrolysis by enzyme to form diffusion zone by specific dye reaction. The diameters of the zones and the log of pure enzyme activity have high linearly. The basis of the diameters with feed extracts can to count enzyme activity, and also can use to compare both pure enzyme on similar activity. Further, radial enzyme diffusion to measuring activities of added phytase in chick or pig gastrointestinal tract contents, to understand the phytase stability in GI tract.