Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The ingestive behavior and the ingestion of forage by beef heifers were evaluated in the vegetative and flowering stages of ryegrass (Lolium multiflorum L.). The treatments were: grazing exclusively on ryegrass, ryegrass intercropping with vetch (Vicia sativa L.) or red clover (Trifolium pratense L.). The grazing method was continuous with variable stocking. The experimental design was the completely randomized with repeated measures arrangement, three forage systems and three repetitions of area. For evaluations of forage intake, chromic oxide was used as an indicator of fecal production and heifers were considered as experimental units. The forage mass, allowance of forage and allowance of leaf blades were, 1596.2 kg / ha DM, 12 kg DM / 100 kg BW and 4.5 kg DM / 100 kg BW respectively. The participation of vetch and red clover in the forage mass corresponded to 13.2% and 4.5% respectively in the vegetative stage. In the flowering stage, the participation of legumes corresponded to 0.6%. In forage as grazed, crude protein (17.8%), neutral detergent fiber (55.8%) and in situ dry matter digestibility (76.7%) were similar among forage systems. These variables differed between phenological stages of ryegrass. The grazing time differed between the systems being superior in the system with vetch. The forage intake rate in the clover system was higher than the other systems. The dry matter intake was similar among forage systems and was higher in the vegetative stage compared to the flowering stage. The average daily gain was similar among forage systems and phenological stages. With little participation of red clover or vetch in the herbage mass intercropped with ryegrass, it does not modify the intake of dry matter, crude protein and neutral detergent fiber, resulting in the same performance of beef heifers. / Foram avaliados o comportamento ingestivo e a ingestão de forragem por bezerras de corte, nos estádios vegetativo e de florescimento do azevém (Lolium multiflorum L.). Os tratamentos foram: pastagem exclusiva de azevém, azevém consorciado com ervilhaca (Vícia sativa L.) ou com trevo vermelho (Trifolium pratense L.). O método de pastejo foi o contínuo com lotação variável. O delineamento experimental foi o inteiramente casualizado com medidas repetidas no tempo, três sistemas forrageiros e três repetições de área. Para as avaliações da estimativa de ingestão de forragem, foi utilizado o óxido de cromo como indicador da produção fecal e as bezerras foram consideradas as unidades experimentais. A massa de forragem, oferta de forragem e oferta de lâminas foliares foram: 1596,2 kg/ha de MS, 12 kg de MS/100 kg PC e 4,5 kg de MS/ 100 kg PC, respectivamente. A participação de “ervilhaca” e “trevo vermelho” na massa de forragem correspondeu a 13,2% e 4,5% respectivamente no estádio vegetativo. No estádio de florescimento o percentual das leguminosas correspondeu a 0,6%. Na forragem da simulação do pastejo, a proteína bruta (17,8%), fibra em detergente neutro (55,8%) e digestibilidade in situ da matéria seca (76,7%), foram similares entre os sistemas forrageiros. Essas variáveis diferiram entre estádios fenológicos do azevém. O tempo de pastejo diferiu entre os sistemas sendo superior no sistema com ervilhaca. A taxa de ingestão de forragem no sistema com trevo foi superior aos demais sistemas. A ingestão de matéria seca foi similar entre os sistemas forrageiros e foi maior no estádio vegetativo em relação ao estádio de florescimento. O ganho médio diário foi semelhante entre sistemas forrageiros e estádios fenológicos. Com pequena participação de “trevo vermelho” ou “ervilhaca” na massa de forragem consorciada com azevém, a ingestão de matéria seca, de proteína bruta e de fibra em detergente neutro não são modificadas resultando em mesmo desempenho de bezerras de corte.

Characteristics of forage intake process by lambs grazing Italian ryegrass pasture (Lolium multiflorum Lam.) were studied, from the hypothesis that different phenological stages of the plant may influence the food gathering process by grazing animals. The experiment was carried out from May to November of 2007 in the Federal University of Santa Maria. Evaluations where made in three occasions within phenological stages of annual ryegrass: Vegetative (11/09), Pre-flowering (14/10) and Flowering (11/11). Eight female lambs (45.0 ± 4.3 kg), Ile de France x Texel crossbreed, with an average age of eight months were utilized. To quantify intake rate and grazing behavior parameters by lambs, grazing tests were conducted. Forage mass, sward height, vertical structure of the pasture and chemical composition of the forage apparently ingested by the lambs were evaluated to determine pasture characteristics. A completely randomized design with three treatments and five replicates in the vegetative stage and six replicates in the other phenological stages was used. Intake rate, bite mass and bite depth were similar (P>0.05) between different stages with a forage on offer of 13.7kg of dry matter per 100kg of live weight. At vegetative stage, bite rate is negatively determined by sward height. At pre-flowering and flowering stages grazing time is positively influenced by sward height. The bite depth is positively influenced by the sward height and negatively influenced by stem bulk density in all phenological stages. The bite rate is negatively influenced by sward height at the vegetative stage of Italian Ryegrass. At the pre-flowering and flowering stage the grazing time is positively influenced by sward height. Grazing time (GT= 27.46 + 0.09day) and number of bites (NB= -175.04 + 9.41day) increased linearly during the pasture cycle. The smaller bite rate was at 135º day after Italian ryegrass emergence and the greater time per bite happened at 146º day. In non limiting forage on offer, lambs maintained the rate of intake constant by increasing bite rate. Among the herbage attributes, the sward height is the most important to determine changes in the grazing behavior of lambs on Italian Ryegrass pasture. / Foram estudadas as características do processo de ingestão de forragem por cordeiras em pastagem de azevém (Lolium multiflorum Lam.), a partir da hipótese de que diferentes estádios fenológicos do pasto influenciam no processo de captura de alimento por animais em pastejo. O experimento foi desenvolvido no período de maio a novembro de 2007 na Universidade Federal de Santa Maria e as avaliações foram realizadas em três datas nos estádios fenológicos do azevém: Vegetativo (11/09), Pré-florescimento (14/10) e Florescimento (11/11). Foram utilizadas oito cordeiras, cruzas Ile de France x Texel com oito meses de idade e 45,0 ± 4,3 kg de peso vivo, em média. Foram realizados testes de pastejo para quantificar a taxa de ingestão de matéria seca (MS) pelas cordeiras e variáveis de comportamento ingestivo de acordo com a metodologia adaptada de PENNING; HOOPER (1985). Na pastagem foram realizadas avaliações de massa de forragem, altura do dossel, estrutura vertical e composição química da forragem aparentemente colhida. O delineamento experimental foi o inteiramente casualizado, com medidas repetidas no tempo, com três tratamentos e cinco repetições no estádio vegetativo e seis nos demais estádios estudados. Com oferta de forragem de 13,7 kg de matéria seca/100 kg de peso vivo, a taxa de ingestão, a massa do bocado e a profundidade de bocado foram semelhantes (P>0,05) nos diferentes estádios. No estádio vegetativo do azevém a altura do pasto influencia negativamente a taxa de bocados. Nos estádios de pré-florescimento e florescimento a altura do pasto influencia positivamente o tempo de alimentação. A profundidade de bocados é positivamente influenciada pela altura do pasto e negativamente pela densidade de colmos no estrato superior. O tempo de alimentação (TA= 27,46 + 0,09 dia) e o número de bocados totais (NBT= -175,4 + 9,41dia) aumentaram linearmente ao longo do ciclo do azevém. O menor número de bocados por unidade de tempo foi realizado no 135º dia após a emergência do azevém e o maior tempo de formação do bocado foi no 146º. Em azevém, com oferta de forragem não limitante ao consumo, o aumento na taxa de bocados é o mecanismo utilizado por cordeiras para manter a taxa de ingestão constante. Dentre os atributos do pasto, sua altura é o de maior importância para determinar mudanças nas variáveis do comportamento ingestivo.

Made available in DSpace on 2017-07-10T18:08:02Z (GMT). No. of bitstreams: 1 Driano Rezende.pdf: 778367 bytes, checksum: 7597f1358aac607cb4a419129f60518b (MD5) Previous issue date: 2013-02-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The aim of this study was to evaluate the quality of groundwater in the region of Maringá - PR and reduction of nitrate ion with extract of seeds of Moringa oleifera Lam. For this, 38 groundwater sources samples, distributed in Maringá-PR were collected. These samples were sent to the laboratory management control and environmental preservation of the State University of Maringa, where they were subjected to physicochemical analysis. Once evaluated, it was possible to locate sources contaminated with nitrate at different concentrations, some of these (water samples containing 10, 25, 45 and 60 mg L-1 NO3-) were used to evaluate the removal of this ion in jar test equipment, treatment by coagulation / flocculation with the aid of the crude extract of Moringa oleifera Lam seeds (saline and aqueous solutions) (MO). These tests allowed to observe the behavior that the extract exerts MO in different concentrations of nitrate in groundwater. Finally, was evaluated the nitrate íon removal by coagulation / flocculation in jar test equipment combined with filtration tests (two slow domestic filters),it was compared with the filtration of groundwater in natura (without contact with coagulants). Results of the evaluation of groundwater quality in this region have shown risks to human health. The treatment of coagulation / flocculation with Moringa oleifera Lam removed nitrate up to 67% and 87% with the aqueous and saline extracts, respectively. The use of MO seeds extract was satisfactory to removal nitrate íon, however, it was observed that the higher the dosage of the seeds extract, increased the final turbidity (NTU over 30). Combined treatments with slow domestic filters were used to remove the residual turbidity after coagulation / flocculation, however, combined treatment did not meet the Ordinance of the Ministry of Health No. 2914, 2011 for the parameters studied. The best results were obtained in treatment of groundwater in natura with domestic filters, without coagulants, with residual of 40 mgL-NO3- and turbidity between 0 and 1 NTU. This study demonstrated that it is possible to remove nitrate using Moringa oleifera lam seeds extract, however, was observed increased turbidity in reaction becoming a not potable source water. Thus, more research is needed, evaluating different techniques in the active principle extraction present in these seeds to removal of nitrate íon in groundwater. / O objetivo da presente pesquisa foi avaliar a qualidade da água subterrânea da região de Maringá PR com maior atenção à concentração de nitrato e estudar a redução deste íon com extrato bruto de sementes da planta Moringa oleífera Lam. A água subterrânea foi avaliada por meio de amostragens em 38 fontes de água subterrânea, distribuídas na região de Maringá-PR. Estas amostras foram encaminhadas ao laboratório de gestão controle e preservação ambiental da Universidade Estadual de Maringá, onde foram submetidas às análises físico-químicas. Depois de avaliada, foi possível localizar fontes contaminadas com nitrato em diferentes concentrações, algumas destas (amostras de água contendo 10, 25, 45 e 60 mg L-1 de NO3-) foram utilizadas para avaliar a remoção deste íon em equipamento jar test, tratamento por coagulação/floculação com auxílio do extrato bruto das sementes de Moringa oleífera Lam (soluções salina e aquosa) (MO). Estes ensaios possibilitaram observar o comportamento que o extrato de MO exerce em diferentes concentrações de nitrato presente em águas subterrâneas. Por último, foi avaliada a remoção de nitrato por coagulação/floculação em equipamento jar test combinado a ensaios de filtração (dois filtros lentos domésticos), comparados com a filtração da água subterrânea in natura (sem contato com coagulantes) nestes filtros. Os resultados da avaliação da qualidade da água subterrânea na região demonstraram riscos à saúde humana, principalmente por nitrato. O tratamento de coagulação/floculação com a Moringa oleifera Lam removeu nitrato em até 67% e 87% com o extrato aquoso e extrato salino, respectivamente. A utilização dos extratos das sementes de MO foi satisfatória para a remoção do nitrato de águas subterrâneas da região, no entanto, foi observado que, quanto maior a dosagem do extrato das sementes, maior a turbidez final (acima de 30 NTU). Os tratamentos combinados com filtros domésticos lentos foram empregados a fim de remover a turbidez residual após o processo de coagulação/floculação, entretanto, os tratamentos combinados não atenderam à Portaria do Ministério da Saúde nº 2914 de 2011 para os parâmetros estudados. Os melhores resultados nos filtros domésticos foram obtidos com a filtração da água subterrânea in natura, sem contato com coagulantes, que atenderam os padrões de potabilidade, com maior residual de 40 mg L- de NO3- e turbidez entre 0 e 1 NTU. O presente estudo demonstrou que é possível remover nitrato utilizando extrato bruto das sementes da planta Moringa oleifera Lam, no entanto, foi observado o aumento da turbidez no meio reacional, o que inviabilizou o uso para fins potáveis. Assim, são necessárias novas pesquisas, em especial diferentes técnicas na extração do princípio ativo presente nestas sementes para remoção de nitrato em águas subterrâneas.

En i dagsläget vanlig byggteknik i Sverige är användandet av en stålstomme i kombination medprefabricerade betonghåldäck. Detta arbete grundar sig på frågeställningen om KL-träbjälklag skullekunna vara ett reellt alternativ till betongbjälklag i en sådan konstruktion, i kombination medhattbalkar. Som ett första steg skisserades en typkonstruktion för att ha en väl definierad utgångspunkt för enanalys. Utgångspunkten för denna typkonstruktion var främst en studie av två tidigare konstruktioner,konstruerade med stålstomme med hattbalkar och håldäcksbjälklag. Litteraturstudien fokuserade påbakomliggande teorier i relation till bjälklagets funktion i konstruktionen. Ett antal områdendefinierades som utgångspunkt för en teknisk utvärdering. Dessa områden var spännvidder,dimensionering i brottgränstillståndet, dimensionering i bruksgränstillståndet, knutpunkter,dimensionering för olyckslaster, akustik och byggbarhet. Utgående från ovanstående områdenutvärderades så tekniska förutsättningar för användandet av KL-träbjälklag i den aktuellakonstruktionstypen. Det konstaterades att det på många områden finns väl fungerande lösningar ochatt det finns många positiva aspekter med ett lätt och lättmonterat KL-träbjälklag. De problemområdensom hittats kan sammanfattas som: 1. Begränsad spännvidd 2. Ökade horisontella deformationer i bjälklaget 3. Beräkning av svängningar med hänsyn till upplag på stålbalkar 4. Förband mellan bjälklag och hattbalkar 5. Akustisk dimensionering Två av dessa områden valdes för vidare analys; förband mellan bjälklag och hattbalkar samt denbegränsade spännvidden. För förbandet utvecklades en lösning med en klack på hattbalkens fläns ikombination med en slits i KL-träskivan som enkelt ska kunna hakas på vid montage. För att ta krafterlängs balkens längd måste dock lösningen sedan kompletteras med ett skruvförband genombalkflänsen. Förhoppningen är att en enklare lösning för att ta dessa förhållandevis små krafter skakunna utvecklas som komplement till det primära förbandet med klack och slits. Handberäkningarutfördes för det utvecklade förbandet och det konstaterades att det är möjligt att utforma ett sådantförband, med rimliga dimensioner, för alla verkande laster. Som den sista delen av arbetet studerades lösningar för att kunna uppnå längre spännvidder, för ettplattbjälklag är spännvidden begränsad till något mindre än 7,7m. Olika typer av samverkansbjälklagstuderades och det konstaterades att samverkan med ett prefabricerat betongbjälklag med en limmadförbindelse skulle kunna vara en lämplig lösning. Limmade förbindelser studerades så mer ingåendeoch det konstaterades att en limmad förbindelse mellan trä och prefabricerad betong medför storstyrka och styvhet. Upp mot 100% samverkan har observerats för samverkansbjälklag med denna typav förbindelse. En osäkerhetsfaktor är dock långtidseffekter, där fler studier behöver hittas ellerutföras för att få en större kunskap på området. Handberäkningar utfördes enligt teorin i SS-EN 1995-1-1 på två typer av samverkansbjälklag med ett antal olika dimensioner. I beräkningarna medräknades100% samverkansgrad. Det konstaterades att 9m spännvidd skulle kunna uppnås med en kombinationav KL-trä och betong, medan 12m spännvidd kan uppnås med hjälp av mellanliggande träreglar. Andraberäkningsmodeller för svängningar där egenfrekvensen inte är den begränsande faktorn skulle kunna leda till bättre resultat för denna typ av samverkansbjälklag. / A currently common building technology in Sweden is the use of a steel structure in combination withprefabricated HD/F concrete slabs. This work is based on the issue of whether CLT slabs could be asuitable alternative to concrete slabs in such a structure, in combination with the type of weldedplated beams that are often called hat beams. As a first step a type-structure was sketched to have a well-defined starting point for an analyze. Thebasis for this structure was mainly a study of two designs constructed with steel structures composedof hat beams and HD/F slabs. The literature study was focused on underlying theories in relation to theslabs function in the structure. A number of areas were defined as a basis for an evaluation of thebuilding type. These areas where spans, design in the ultimate limit state, design in the serviceabilitylimit state, joints, design for accidental actions, acoustics and constructability. Based on the above,technical conditions for the use of CLT slabs in the building type in question were evaluated. It wasfound that in many areas there were working solutions, and that there are many positive aspectsrelated to the use of a light and easily mounted CLT slab. The issues that were found can be concluded as: 1. Limited span lengths 2. An increase of horizontal deformations in the slab 3. Calculations of vibrations with respect to the flexible support 4. Joints between slabs and hat beams 5. Acoustic design Two of these issues were chosen for further analysis: joints between slabs and beams and the limitedspan length. A solution was developed for the joint, composed of a heel on the flange of the steelbeam in combination with a slit in the CLT slab. The joint is supposedly easy to mount during assembly.To be able to handle the forces along the length of the beam the solution must however becomplemented with a secondary screw joint through the flange of the beam. The hope is that a simplersolution to handle these relatively small forces can be developed, as complement to the primary jointmade up of the heel and slit. Calculations were performed by hand for the developed joint and it wasfound that it is possible to design such a joint, with reasonable dimensions, for all the acting loads. As the last part solutions to achieve longer spans were studied, for a flat CLT slab the span length islimited to somewhat less than 7,7m. Different types of composite slabs were studied and it was notedthat a composite with a prefabricated concrete slab and a glued connection could be a suitablesolution. Glued connections were then studied more closely, and I was found that a glued connectionbetween wood and prefabricated concrete entails great strength and rigidity. About 100% unitedaction has been observed for this type of connection. An uncertain factor is however long-term effectswhere further studies need to be found or performed to achieve more knowledge. Hand calculationswere performed using the theory in SS-EN 1995-1-1 on two types of composite slabs for a couple ofdifferent dimensions. In the calculations 100% united action was used. It was found that 9m span couldbe achieved with the combined action of CLT and concrete, while 12m could be achieved using woodenstuds for spacing. Other theories for the calculations where the natural frequency isn’t the limiting factor could lead to better results for this kind of composite slabs.

This paper describes four tools for verification security protocols Athena, Casper, Isabelle and Murphi. Each tool is briefly characterized and implementation of protocol Needham Schroeder. One part of this paper is comparing of selected tools. The second part of this paper describes in detail a tool Athena and mentions examples of verified protocols. By each protocol is stated a specifications of communication, a detected attack and results of own verification. At the end compares this paper verification results with already publicated attacks.

Les leucémies aiguës myéloïdes (LAM) sont des maladies hématologiques hétérogènes caractérisées par une prolifération clonale des blastes myéloïdes qui s’infiltrent dans la moelle osseuse (MO), le sang et d’autres organes. Identifiée comme le type le plus courant de leucémie aiguë chez l’adulte avec 80% des cas, la LAM est synonyme de rechute et de mauvais pronostic, avec 70% des patients étant confrontés à une mortalité dans l’année suivant le diagnostic. La présence des cellules souches leucémiques (CSL) a été associée à une résistance à la chimiothérapie et à une rechute dans la LAM. Le microenvironnement tumoral a été décrit pour son rôle clé dans la régulation des CSL par l’interaction des voies de signalisation. La voie des Bone Morphogenetic Proteins (BMP) est fortement impliquée dans la régulation des cellules souches hématopoïétiques (CSH), mais elle a également été reconnue pour réguler les CSL. Ici, nous avons identifié des concentrations élevées de BMP2 et BMP4 dans la MO des patients atteints de LAM au moment du diagnostic. De plus, nous avons identifié pour la première fois une nouvelle cascade de signalisation impliquant la liaison de BMP4 au récepteur BMPR1A, qui induit l’expression de ΔNp73 et NANOG. L’activation de cette signalisation favorise un phénotype proche des cellules souches dans les cellules leucémiques. Par conséquent, nous avons émis l’hypothèse que cette voie est responsable de la capacité de résistance des cellules leucémiques à la chimiothérapie. En outre, nous avons identifié BMPR1A/ΔNp73/NANOG comme marqueurs potentiels du pronostic dans la LAM, en raison de leurs surexpressions au moment du diagnostic associé à une rechute dans les trois ans. Lorsque nous avons analysé des échantillons de LAM lors d’une rechute, nous avons constaté des taux plus élevés de l’isoforme ΔNp73 par rapport à ceux de patients au moment du diagnostic. D’autre part, nous avons identifié une forte expression du récepteur BMPR1A, ΔNp73, NANOG, SOX2 et ID1 dans les cellules leucémiques primaires résistantes à court terme. Ces résultats sont en corrélation avec ce que nous avons observé dans les cellules résistantes de LAM, où BMPR1A, ΔNp73, NANOG et ID1 semblent être impliqués dans la capacité de résistance des cellules de LAM face à la chimiothérapie. La modulation et le ciblage des éléments de la voie BMP et des gènes associés identifiés au travers de notre étude représentent donc une approche prometteuse pour le développement de stratégies thérapeutiques innovantes et plus efficaces contre les LAM / Acute myeloid leukemias (AML) are heterogeneous hematological malignancies characterized by a clonal proliferation of myeloid blasts which infiltrate the bone marrow, blood and other organs. Identified as the most common type of acute leukemia in adults with 80% of cases, AML is associated with high relapse and poor prognosis where 70% of patients face mortality within one year after diagnosis. Leukemic stem cell (LSCs) presence has been related to resistance to chemotherapeutic agents and relapse in AML. The tumor microenvironment has been described for its key role regulating LSCs through the crosstalk of signaling pathways. Bone Morphogenetic Proteins (BMP) pathway is highly involved in hematopoietic stem cell (HSC) regulation, but has also been recognized to regulate LSCs. Here, we have identified high concentrations of BMP2 and BMP4 in bone marrow (BM) AML samples at diagnosis. Furthermore, we have identified for the first time a new signaling cascade, involving the binding of BMP4 to BMPR1A receptor, which induces the expression of ΔNp73 and NANOG. Activation of this signaling promotes a stem-like phenotype in leukemic cells. Therefore, we hypothesized that this signaling is responsible for the resistant capacity of leukemic cells to chemotherapy. In addition, we have reported BMPR1A/ΔNp73/NANOG as potential AML prognosis markers, due to their overexpression at diagnosis associated to an increased rate of relapse of AML patients within three years. When we analyzed AML samples at relapse, higher levels of ΔNp73 isoform were found compared to patients at diagnosis. Moreover, we have identified high expression of the BMPR1A receptor, ΔNp73, NANOG, SOX2 and ID1 in short-term resistant primary leukemic cells. These results correlate with what we observed in AML resistant cells, where BMPR1A, ΔNp73, NANOG and ID1 seem to be implicated in driving the resistant capacity of AML cells to drug therapy. Therefore, modulation and targeting of the BMP pathway elements and related genes identified with our study, represent a promising approach towards the development of new and more effective therapeutic strategies against AML

De nombreux problèmes scientifiques et industriels ont besoin de la résolution de systèmes linéaires non symétriques à grande échelle, qui sont décrits par des matrices creuses de très grande taille. On utilise fréquemment dans ce cas des méthodes numériques itératives et on fait appel au parallélisme pour une résolution rapide et efficace. L'algorithme GMRES(m) est une méthode itérative qui donne de bons résultats dans la plupart des cas. Mais on observe une limitation à sa parallélisation en raison des nombreuses communications produites. Dans quelques cas, la convergence est atteinte très lentement, voire jamais. Nous présentons dans cette thèse une méthode hybride GMRES(m)/LS-Arnoldi qui accélère la convergence grâce à la connaissance des valeurs propres calculées parallèlement par la méthode d'Arnoldi pour les cas réels, avec son implantation sur des supercalculateurs. Une extension aux cas complexes est également étudiée. La dernière tendance du calcul global, le calcul de grille, propose l'exploitation massive des ressources vacantes des réseaux locaux ainsi que sur Internet. Son avantage peut être énorme pour l'exécution d'applications parallèles. L'environnement XtremWeb est un système de grille léger, tolérant aux défaillances et sécurisé pour l'exécution d'applications parallèles. Il est un environnement de calcul haute-performance, une plate- forme de grille logicielle d'expérimentation pour des institutions académiques ou industrielles. Nous présentons dans cette thèse les implantations de la méthode GMRES(m) sur ce système de grille XtremWeb ainsi que sur un environnement distribué de calcul LAM-MPI. Nous avons fait de multiples tests sur grille et supercalculateur. Des performances que nous avons obtenues, nous constatons les avantages et les inconvénients de ces plates-formes de calcul différentes.

Amorphous metals have been discovered in 1960 and, because of their structures, exhibit very unique mechanical, magnetic and chemical properties that can have various applications. These properties qualify them as the potential material of the future. This work focuses on a new laser ablation technique to synthesize nanoparticles of amorphous metals from aqueous feedstock. One of the critical factors in the production of amorphous metal is the cooling rate used to synthesize them. The laser ablation of microparticle aerosol (LAMA) process used in this work, with a cooling rate estimated of 10¹² K/s, has all the characteristics required for the production of such metallic glasses. A Collison nebulizer is used to generate microdroplets of a nitrate solution containing the corresponding ratio of metals for the production of a Zr-Al-Ni based alloy. Once dried and conditioned, these microdroplets leave solid microparticles which are ablated by an excimer laser producing nanoparticles that are then filtered by virtual impaction. In order to characterize the nanoparticles obtained with this process nanoparticulate films produced by LAMA have been analyzed by optical profilometry, scanning electron microscopy (SEM) equipped with energy-dispersive x-ray spectroscopy (EDS) and transmission electron microscopy (TEM) equipped with EDS. The results agree with a hypothesis that the films contain oxidized, amorphous metal on the surface of the films. When the films are thin, they are fully oxidized, and simultaneous segregation of Zr occurs to the surface. The hypothesis and the results are discussed. / text

published_or_final_version / Architecture / Master / Master of Architecture

published_or_final_version / Architecture / Master / Master of Architecture