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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The leaf biomass flows of Alexandergrass (Urochloa plantaginea (Link) Hitch), the intensity and frequency of defoliation were evaluated using Zero, 100, 200 or 300 kg ha-1 of nitrogen (N), in the form of urea. The grazing method was continuous with variable number of animals to keep the forage mass in 3000 kg ha-1 DM. The experimental animals were Angus heifers with age and initial average body weight of 15 months and 241.5±5.7 kg, respectively. The experimental design was completely randomized following a repeated measure arrangement measures with four treatments and variable number of experimental units. Application of 100 kg ha-1 N provided higher leaf blades growth flow. The senescence and intake fluxes and defoliation intensity were similar in N fertilizer rates used. The return frequency (days) was influenced by N rates and evaluation periods. It is recommended using 100 kg ha-1 N in Alexandergrass pasture. / Os fluxos de biomassa foliar do papuã (Urochloa plantaginea (Link) Hitch), a intensidade e frequência de desfolha foram avaliados com o uso de Zero, 100, 200 ou 300 kg ha-1 de nitrogênio (N), na forma de ureia. O método de pastejo foi contínuo com número variável de animais para manter a massa de forragem em 3000 kg ha-1 de MS. Os animais experimentais foram bezerras Angus com idade e peso corporal médio inicial de 15 meses e 241,5±5,7 kg, respectivamente. O delineamento experimental foi inteiramente casualizado, com medidas repetidas no tempo, com quatro tratamentos e número variável de unidades experimentais. O uso de 100 kg ha-1 de N proporcionou maior fluxo de crescimento de lâminas foliares. Os fluxos de senescência e de consumo e a intensidade de desfolha foram similares nas doses de N utilizadas. A frequência de retorno (dias) foi influenciada pelas doses de N e períodos de avaliação. É recomendada a utilização de 100 kg ha-1 de N em pastagem de papuã.

Des polymères supramoléculaires liés par liaisons hydrogènes basés sur des motifs associatifs de type benzène-1,3,5-tricarboxamide (BTA) et bis-urée ont été étudiés comme support dynamique pour la catalyse. Les propriétés catalytiques d'un lot de ligands, comprenant une série de onze nouveaux ligands bis-urées, et des co-monomères complémentaires ont été étudiés pour diverses réactions catalysées par des métaux. Des copolymères formés par mélange de monomères achiraux fonctionnalisés par des phosphines (les ligands) et des additifs sans fonctions phosphines (les co-monomères) ont été étudiés comme supports pour la catalyse asymétrique. L'objectif était de transférer, amplifier et changer la chiralité supramoléculaire du support polymère vers le centre métallique intrinsèquement achiral localisé à sa périphérie. Des mélanges de BTA ont été utilisés aves succès dans deux différentes catalyses asymétriques avec jusqu'à 85% ou 80% d'e.e. pour respectivement l'hydrogénation de l'itaconate de diméthyle catalysée par le rhodium et l'hydrosilylation de la 4'-nitro-acétophénone catalysée par le cuivre. Les centres catalytiques de rhodium et de cuivre supportés par les BTA montrent de fortes propriétés d'amplification de chiralité : i) pour la catalyse au rhodium, la quantité nécessaire de co-monomère chiral peut être réduite jusqu'à un quart de celle du ligand sans détérioration de l'énantioséléctivité de la réaction et ii) la chiralité du catalyseur au cuivre peut être changée pendant le déroulement de la réaction. Une autre plateforme, basée sur des mélanges de monomères bis-urée, a aussi été étudiée dans plusieurs réactions asymétriques catalysées par des métaux mais de l’énantioséléctivité n’a été obtenue que pour l’hydrosilylation de la 4’-nitro-acétophénone catalysé par le cuivre (22% e.e.). Dans le contexte de l’organocatalyse, la possibilité de modifier l’activité d’un centre catalytique de type thiourée en contrôlant son auto-assemblage a aussi été étudié. Au bilan, nos études montrent clairement les propriétés innovantes de catalyseurs supportés par des polymères supramoléculaires liés par liaisons hydrogène. / Hydrogen-bonded supramolecular polymers based on benzene-1,3,5-tricarboxamide (BTA) and bis-urea recognition units were investigated as dynamic scaffolds for catalysis. The catalytic properties of a full set of ligands, including a series of eleven new bis-urea ligands, and complementary co-monomers have been investigated in various metal-catalyzed reactions. Co-polymers formed by mixing an achiral phosphine-functionalized monomer (the ligand) and a chiral phosphine-free additive (the co-monomer) were investigated as scaffolds for asymmetric catalysis. The aim was to transfer, amplify and switch the supramolecular chirality of the polymer scaffold to intrinsically achiral metal centres located at its periphery. BTA mixtures have been successfully applied in two different asymmetric reactions providing up to 85% and 80% e.e. in the rhodium-catalysed hydrogenation of dimethylitaconate and in the copper-catalysed hydrosilylation of 4’-nitro-acetophenone respectively. The BTA scaffold supporting the catalytic rhodium and copper centres display strong chirality amplification properties: i) for the rhodium catalysis, the amount of chiral co-monomer can be decreased down to one-fourth of that of the ligand without deteriorating the enantioselectivity of the reaction and ii) the chirality of the copper catalyst can be switched during the course of the catalytic reaction. In the case of the bis-urea platform, mixtures of monomers have been investigated in several asymmetric metal-catalysed reactions but selectivity was obtained only for the copper-catalyzed hydrosilylation of 4’-nitro-acetophenone (22% e.e). We also tested the use of supramolecular polymers in the context of organocatalysis: the possibility of tuning the activity of a thiourea catalytic centre by controlling its self-assembly behaviour was investigated. Overall, our studies clearly reveal the innovative properties of catalysts supported by hydrogen-bonded supramolecular polymers

Improvised explosives may be based on smokeless gunpowder, fertilizers, or inorganic oxidizers such as nitrate (NO3-), chlorate (ClO3-), and perchlorate (ClO4-) salts. Identification is a priority for the military and law enforcement but due to their varying physical properties and complexity, identification can be challenging. Consequently, three methods have been developed to aid in presumptive and confirmatory detection. Smokeless powder contains plasticizers, stabilizers, dyes, opacifiers, flash suppressants, and other compounds. Identification of these additives can narrow down or identify the brands of smokeless powder used in a device. Fourteen organic smokeless powder components were identified by capillary electrochromatography (CEC) using a hexyl acrylate monolithic stationary phase coupled to UV detection and time-of-flight mass spectrometry (TOF-MS). The CEC-UV method efficiently detects all 14 organic components, while TOF-MS provides sensitivity and selectivity. A mixed smokeless powder component standard was analyzed and the composition of the additive package in commercial smokeless powders determined. Detection limits ranged from 1.0 – 3.2 μg/ml and analysis time was 18 minutes. Second, a procedure for the detection of urea nitrate (UN) and ammonium nitrate (AN) by infusion electrospray ionization - mass spectrometry (ESI-MS/MS) was developed. Solubility tests were performed to find a solvent for both UN and AN that did not cause UN to dissociate. Two adduct ions were detected for each explosive: for AN, m/z 178 [2AN+NH4]+ and m/z 258 [3AN+NH4]+ ions, and for UN m/z 185 [UN+NO3]− and m/z 248 [UN+HNO3+NO3]−. Specificity of the analysis was examined by mixing the explosives with various salts and interferents. Gas-phase adduct ions were useful in distinguishing between ion pairs and mixed salts. Finally, a paper microfluidic device (PMD) was developed as a presumptive test using colorimetric reagents for the detection of ions associated with improvised explosives. The device was configured to test for nitrate (NO3-), nitrite (NO2-), chlorate (ClO3-), perchlorate (ClO4-), and urea nitrate (UN). Proof of concept was performed using extracts of soil containing inorganic oxidizers. The development of these analytical methods allows the detection of smokeless powder components, fertilizers, and oxidizers and expands the suite of analytical methods available for the analysis of improvised explosives.

Les cristaux apériodiques possèdent la propriété d’avoir un ordre à grande distance mais sans la symétrie de translation. Ces cristaux se décrivent dans des superespaces cristallographiques de dimension supérieure à trois. Dans ce mémoire, nous nous intéressons plus particulièrement aux brisures de symétrie présentes dans de tels espaces cristallographiques en considérant la famille prototype de n-alcane/urée. Des études par diffraction de rayons X sur sources synchrotron révèlent de multiples solutions structurales impliquant des changements ou non de la dimension du groupe de superespace. Une fois la caractérisation du paramètre d’ordre et de la brisure de symétrie faite nous présentons les phénomènes prétransitionnels critiques associés à ces transitions de phase de type groupe/sous-groupe. La diffusion cohérente de neutrons et la diffusion de rayons X inélastiques permettent une analyse dynamique des différentes excitations dans ces matériaux (phonons, phasons). Les composés d’inclusion avec des molécules invitées courtes (alcane CnH2n+2 avec n variant de 7 à 13) révèlent à température ambiante des phases « quasi-liquides » uni-dimensionnelles. Ce désordre dynamique le long de la direction d'incommensurabilité de ces matériaux génère à basse température des solutions structurales nouvelles (composite monoclinique intermodulé, ancrages commensurables). / Aperiodic crystals have the property to possess long range order without translational symmetry. These crystals are described within the formalism of superspace crystallography. In this manuscript, we will focus on symmetry breakings which take place in such crystallographic superspace groups, considering the prototype family of n-alkane/urea. Studies performed by X-ray diffraction using synchrotron sources reveal multiple structural solutions implying or not changes of the dimension of the superspace. Once the characterization of the order parameter and of the symmetry breaking is done, we present the critical pretransitionnal phenomena associated to phase transitions of group/subgroup types. Coherent neutron scattering and X-ray scattering allow a dynamical analysis of different kind of excitations in these materials (phonons, phasons). The inclusion compounds with short guest molecules (alkane CnH2n+2, n varying from 7 to 13) show at room temperature unidimensional “liquid-like” phases. The dynamical disorder along the incommensurate direction of these materials generates new structural solutions at low temperature (intermodulated monoclinic composite, commensurate lock-in).

L'objectif de cette thèse est de développer un ensemble de modèles numériques afin de simuler les processus physico-chimiques dans la chambre de combustion ainsi que dans le système de post-traitement des gaz d'échappement des moteurs à combustion interne. Dans la première partie de cette thèse, deux nouveaux modèles d'évaporation de gouttelettes et de film liquide multi-composants sont proposés. Dans le modèle d'évaporation des gouttelettes, une nouvelle expression du débit d'évaporation a été proposée. Il a été montré que la prise en compte du flux de chaleur dû à la diffusion d'enthalpie des espèces est primordiale dans le bilan d'énergie à l'interface de la goutte. De plus, les investigations numériques ont montré l'importance de la prise en compte d'une équation d'état de gaz réel dans les conditions de hautes pressions et / ou de basses températures ambiantes. Un modèle d'évaporation multi-composant de film liquide a ensuite été développé sur la base du modèle d'évaporation de film mono-composant déjà mis en oeuvre dans le code industriel IFP-C3D. En particulier, les lois de paroi ont été généralisées pour l'évaporation du film multi-composant de manière similaire au modèle de l'évaporation des gouttelettes. Il a été montré l'importance de la température de la paroi dans le processus d'évaporation d'un film liquide. Contrairement à l'évaporation des gouttes, les investigations numériques effectuées ont montré que l'utilisation d'une équation d'état de gaz parfait conduit à des résultats proches de ceux qui sont obtenus en utilisant une équation d'état de gaz réel. Ceci se traduit par un gain en temps de calculs important. La deuxième partie de la thèse utilise les modèles d'évaporation, développés dans la première partie de la thèse, avec un nouveau modèle de thermolyse développé afin de produire de l'ammoniac nécessaire pour le système SCR. Dans la présente étude, l'ammoniac est produit à partir de la solution aqueuse d'urée injectée dans la ligne de tuyau d'échappement. L'eau s'évapore et l'urée se décompose en ammoniac nécessaire pour le système SCR. L'évaporation de l'eau est modélisée avec les modèles d'évaporation proposés dans la première partie de cette thèse, avec quelques modifications afin de prendre en compte l'influence de l'urée sur l'évaporation de l'eau. Un nouveau modèle de thermolyse multi-étape pour l'urée a été ensuite implanté dans IFP- 3D afin de simuler la distribution de l'ammoniac gazeux à l'entrée de système de dépollution SCR. Ce modèle est également capable de simuler la formation de sous- roduits (dépôt solide) de la thermolyse d'urée. Les résultats numériques des modèles développés ont permis de montrer le potentiel des développements réalisés au cours de ce travail dans le cadre d'applications industrielles. / The aim of the present thesis is to develop a set of numerical models in order to simulate the physical and chemical processes in combustion chamber as well as in exhaust gas after-treatment system of internal combustion engines. In the first part of the thesis, two new multi- omponent evaporation models for droplet and liquid film are proposed. In the droplet evaporation model, a new expression of the evaporation rate has been proposed. It has been shown that taking into account the heat flux due to the enthalpy diffusion of species is of primary significance in the energy balance at the droplet surface. In addition, numerical investigations have shown the importance of considering a real gas equation of state in the high pressure and/or low temperature conditions. A multi-component liquid film evaporation model has then been developed based on the single-component film evaporation model already implemented in IFP-C3D code. Particularly, the wall laws have been generalized for the multi-component film evaporation taking into account the mentioned features applied to the droplet evaporation model. The importance of surface temperature in the evaporation of liquid film has also been shown. Contrary to the droplet evaporation, the numerical investigations on film evaporation have shown that using an ideal mixture equation of state leads to results similar to those obtained using a real gas equation of state. The second part of the thesis uses the evaporation models, developed in the first part of the thesis, along with a new developed thermolysis model in order to produce the ammonia needed for the SCR system. In the present study, ammonia is produced from the urea-water solution injected into the exhaust pipe line. Water evaporates and urea decomposes to ammonia needed for SCR system. The evaporation of water is modeled with the proposed evaporation models in the first part of the present thesis with some modifications in order to take into account the influence of urea on the water evaporation. New multi-step thermolysis model for urea is then implemented in the IFP-C3D code in order to simulate the distribution of gaseous ammonia at the entrance of SCR system. The present model is also able to simulate the formation of solid by-products from urea thermolysis. The numerical results of the developed models allow us to assess the contribution of the developments made during this work in the context of industrial applications.

Made available in DSpace on 2016-01-26T18:56:21Z (GMT). No. of bitstreams: 1 Katia.pdf: 198882 bytes, checksum: bd1173aa5b4a5537dec7db52bbd82ed1 (MD5) Previous issue date: 2006-02-20 / The neem tree (Azadirachta indica A. Jussieu) is an exotic tropical tree that has been studied because its gets azadiractin (AZ) an important active principle with medicinal and insecticide properties. However its forestry characteristics and its handling are few known, so this work comes to contribute with the knowledge of this specie. This work was carried out at west region of São Paulo state. The treatments were six nitrogen rates of urea corresponding at 0; 9; 18; 27; 36; e 45 g of N*plant-1. The experimental design was a randomized blocks with six treatments and five repetitions with four plants per fragment. The characteristics evaluated were: height of tree, Diameter at Breast Height (DBH at 1,30 m from soil) and Diameter at Lap Height (DLH at 0,05 m from soil) The evaluation system to collect measures was in a permanent plot system. There were no statisticals differences among the treatments at 5% of significance. / O nim, Azadirachta indica A Jussieu, é uma espécie arbórea exótica de clima tropical que tem sido muito pesquisada por apresentar azadiractina, princípio ativo com propriedades medicinais e inseticidas. No entanto, as características silviculturais e técnicas para seu manejo ainda são pouco conhecidas. Para contribuir com o conhecimento desta espécie, este experimento foi desenvolvido na região oeste do estado de São Paulo. Os tratamentos foram seis doses diferentes de adubação nitrogenada na forma de uréia equivalendo a 0; 9; 18; 27; 36; e 45 g de N*planta-1. O delineamento experimental foi em blocos casualizados, com 6 tratamentos e 5 repetições, onde cada parcela conteve 4 plantas. Anotou-se a altura da planta e o Diâmetro à Altura do Colo (DAC a 0,05 m do solo), o Diâmetro à Altura do Peito (DAP a 1,30 m do solo). O sistema de avaliação para coleta de dados adotado foi o de parcelas permanentes. Os resultados foram submetidos a análise estatística, que demonstram efeito não significativo a 5% de probabilidade para os tratamentos aplicados.

Made available in DSpace on 2016-07-18T17:51:05Z (GMT). No. of bitstreams: 1 Katia.pdf: 198882 bytes, checksum: bd1173aa5b4a5537dec7db52bbd82ed1 (MD5) Previous issue date: 2006-02-20 / The neem tree (Azadirachta indica A. Jussieu) is an exotic tropical tree that has been studied because its gets azadiractin (AZ) an important active principle with medicinal and insecticide properties. However its forestry characteristics and its handling are few known, so this work comes to contribute with the knowledge of this specie. This work was carried out at west region of São Paulo state. The treatments were six nitrogen rates of urea corresponding at 0; 9; 18; 27; 36; e 45 g of N*plant-1. The experimental design was a randomized blocks with six treatments and five repetitions with four plants per fragment. The characteristics evaluated were: height of tree, Diameter at Breast Height (DBH at 1,30 m from soil) and Diameter at Lap Height (DLH at 0,05 m from soil) The evaluation system to collect measures was in a permanent plot system. There were no statisticals differences among the treatments at 5% of significance. / O nim, Azadirachta indica A Jussieu, é uma espécie arbórea exótica de clima tropical que tem sido muito pesquisada por apresentar azadiractina, princípio ativo com propriedades medicinais e inseticidas. No entanto, as características silviculturais e técnicas para seu manejo ainda são pouco conhecidas. Para contribuir com o conhecimento desta espécie, este experimento foi desenvolvido na região oeste do estado de São Paulo. Os tratamentos foram seis doses diferentes de adubação nitrogenada na forma de uréia equivalendo a 0; 9; 18; 27; 36; e 45 g de N*planta-1. O delineamento experimental foi em blocos casualizados, com 6 tratamentos e 5 repetições, onde cada parcela conteve 4 plantas. Anotou-se a altura da planta e o Diâmetro à Altura do Colo (DAC a 0,05 m do solo), o Diâmetro à Altura do Peito (DAP a 1,30 m do solo). O sistema de avaliação para coleta de dados adotado foi o de parcelas permanentes. Os resultados foram submetidos a análise estatística, que demonstram efeito não significativo a 5% de probabilidade para os tratamentos aplicados.

This Master´s thesis deals with the verification calculation of boiler which burns brown coal for the application of the selective catalytic reduction method. The thesis is divided into several parts. In the first of all is performed the calculation of the furnace chamber which involves stoichiometrics calculations and enthalpy calculations of air and flue gas. In the second part the heat balance of the boiler, the boiler losses and the thermal efficiency are determined. After all the heating surfaces are calculed for the verify the dimensions. In the conclusion of the thesis we looked for the temperature range which is used for the SCR application. Then the improvements for the appropriate temperature range are designed.

This work deals with dietary supplements intake and its impact on the performance rise and muscle mass growth of bodybuilders. Twenty-five students (bodybuilders) were chosen for the purpose of this survey; they were divided into four groups according to the dosage of creatine and other dietary supplements (proteins and maltodextrine). Changes of the measured parameters (weight; bustline; weistline; limb girth; body lipid content; creatine and urea content in the urine) were compared during the survey. The tested dietary supplements impact on the muscle mass growth was evaluated on the basis of the acquired results.