CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior / Embora se tenha muitos estudos sobre estresse salino, pouco se conhece sobre os mecanismos individuais de sÃdio (Na+) e cloro (Cl-) na fisiologia de plantas expostas à salinidade. Baseado nisso, objetivou-se, atravÃs deste estudo, avaliar a extensÃo com que os Ãons Na+ e Cl- sÃo acumulados em diferentes partes jovens de feijÃo-caupi [Vigna unguiculata (L.) Walp.] e as suas possÃveis interferÃncias sobre as medidas de transpiraÃÃo. Para comprovar a hipÃtese que os Ãons Na+ e Cl- apresentam modelos diferentes de distribuiÃÃo nas partes vegetativas de feijÃo-caupi e que esse processo nÃo à afetado pela temperatura, foi organizada uma seqÃÃncia metodolÃgica envolvendo trÃs experimentos, onde o experimento I consistiu em avaliar a distribuiÃÃo de Na+ e Cl- em partes jovens de feijÃo-caupi submetido a concentraÃÃes crescentes de NaCl (0; 25; 50; 75 e 100 mM) durante 3 dias, onde ocorreu um maior acÃmulo de cloreto em todas as partes estudadas com exceÃÃo do caule que teve acÃmulo similar de ambos os Ãons. Baseado nessa distribuiÃÃo, utilizou-se a concentraÃÃo de 50mM, pois essa concentraÃÃo nÃo superaria a capacidade de armazenamento e, assim, seria possÃvel, nesse nÃvel, uma recuperaÃÃo (foi mantida durante 6 dias em NaCl e, a partir do 4 dia, as amostras foram divididas em dois lotes). Um lote permanecia com NaCl e o outro trocava a soluÃÃo sem NaCl e assim verificar se essa estratÃgia a planta seria capaz de recuperase. Os resultados corroboram com os obtidos no experimento I com exceÃÃo da primeira folha trifoliolada que acumulou mais Na que Cl. A literatura relata, abundantemente, que nas Ãpocas de verÃo (perÃodo do experimento I), principalmente no semi-Ãrido, as plantas acumulam mais Ãons, onde a temperatura à uma medida de fator climÃtico que pode interferir na distribuiÃÃo de Ãons e esse efeito està ligado à transpiraÃÃo. No experimento III, foi avaliado o efeito combinado de estresse salino e de temperaturas elevadas, com concentraÃÃes de 0 e 100 mM de NaCl e exposiÃÃo a temperaturas de 27; 32; 37 e 42ÂC, separadamente, por um fotoperÃodo de 12 horas. Os resultados corroboram com os obtidos, anteriormente, em que o sÃdio concentrou-se mais nas raÃzes e caules das plantas quando tratadas nas duas Ãltimas temperaturas. Em relaÃÃo ao Ãon cloreto, foi verificado um comportamento similar aos experimentos anteriores, pois este se acumulou, em maior proporÃÃo, nas folhas sob temperaturas de 32 a 42ÂC. Notadamente, o acÃmulo de cloreto està associado à quantidade de Ãgua absorvida durante a aplicaÃÃo do estresse. Em relaÃÃo à transpiraÃÃo, os resultados tambÃm corroboram com os anteriores. Dessa forma, conclui-se que, independente da concentraÃÃo, tempo, recuperaÃÃo e temperatura, o sÃdio à mais concentrado na raiz e caule, enquanto o cloreto concentra-se nas folhas. / Although it has many studies on salinity, little is known about the mechanisms of individual Na+ and Cl- in the physiology of plants exposed to salinity. Based on that meant to use this study to evaluate the extent to which the ions Na+ and Cl- are accumulated in different parts of young cowpea [Vigna unguiculata (L.) Walp.] and the possible interference on the steps of perspiration. To prove the hypothesis that the ions present different models of distribution in vegetative parts of cowpea and this process is not affected by temperature. It organized a string surrounding methodological three experiments. Where will I study was to evaluate the distribution of Na+ and Cl- young in parts of cowpea subjected to increasing concentrations of sodium chloride (0, 25, 50, 75 and 100 mM) for 3 days. In what was a greater accumulation of sodium chloride that in all parts studied, except the stem which accumulation in the equivalent proportions. Based on this distribution used with a concentration of 50 mM because it would not exceed the storage capacity and it was possible that a recovery level (it was held for 6 days in NaCl and from the 4th day the samples were divided into two lots. A lot remains NaCl and other exchanges with the solution without NaCl and thus verify that this strategy the plant would be able to recover it. The results corroborated with those obtained in the experiment I except the 1st trifoliate leaves that accumulated more in that Cl. The literature reports that plenty of times in the summer (period of the experiment I), particularly in semi-arid plants accumulate more ions. Where the temperature is a measure of climatic factors that may interfere with the distribution of ions and whether this effect is linked to transpiration. And then we performed the experiment III to assess the combined effect of salinity and high temperatures, in concentrations from 0 to 100 mM NaCl. Exposed to temperatures of 27, 32, 37 and 42 C, separately, during a photoperiod of 12 hours. The results corroborate with those obtained previously in the sodium has focused more on the roots and stems when treated in the last two temperatures. Regarding the chloride ion, was found a behavior similar to previous experiments, as they accumulated in greater proportion in the leaves at temperatures of 32 to 42 C. Notably the accumulation of chloride, is associated withthe amount of water absorbed during the implementation of stress. Regarding transpiration also corroborate the previous results. Thus it appears that regardless of concentration, time, temperature recovery and the ash is more concentrated in the root and stem while chloride is concentrated in the leaves.

Cette thèse porte sur l'étude de la production d'ions négatifs (INs) en surface pour des applications à la fusion contrôlée. Les INs formés en surface d'un échantillon dans un plasma d'hydrogène à partir de bombardement par les ions positifs sont collectés et analysés en énergie par un spectromètre de masse (SM). Les fonctions de distribution en énergie des INs (FDIs) que mesure le SM sont différentes de celles émises par la surface f(E, Θ) du fait des modifications de trajectoires et d'énergie induites par la traversée du plasma et du SM. Afin de déterminer la FDI émis par la surface f(E, Θ) en se servant des fonctions de distribution mesurée par le SM f''(E) nous avons développé un modèle qui calcule les trajectoires des ions entre la surface et le détecteur du SM. A partir d'une fonction test f(E,Θ) il est alors possible de calculer f''(E) et de comparer à l'expérience. L'élément critique de cette méthode est le choix de f (E, Θ). Le choix effectué dans cette thèse est la fonction de distribution des neutres calculée par le logiciel SRIM pour les particules pulvérisées et rétrodiffusées lors de bombardement d'une surface dans des conditions similaires aux conditions expérimentales. Les résultats du modèle montrent un bon accord entre les FDIs expérimentales et les fonctions calculées, et valident nos calculs et le choix de SRIM.Dans le but de comparer les mécanismes de production et les rendements des INs, une étude comparative a été réalisée sur différents matériaux carbonés. Les FDIs mesurées présentent la même forme à la température ambiante. / This thesis deals with negative ions (INs) surface production for applications in controlled fusion. Negative ions (NIs) formed at the sample surface from positive ions bombardment in hydrogen plasma are collected and analyzed with energy mass spectrometer (MS). The NI energy distribution functions (NIDF) measured by the MS are different from those emitted from surface f(E, Θ) due to modifications trajectories and energies which result when NI cross plasma and MS. In order to determine the NIDF emitted by the surface f(E,Θ) using the NIDF measured by MS f''(E), we developed a model that calculates the ion trajectories between the surface and MS detector. Then from a test function f(E,Θ) it is possible to calculate f''(E) and compare it to the experimental one. The critical issue is this method is the choice of f(E, Θ). The approach used in this thesis is the neutral backscattered and sputtered distribution function calculated by SRIM software during a surface bombardment similar to the experimental conditions. The model resulting show a good agreement between experimental and calculated NIDF, and validate our calculations and the choice of SRIM.In order to compare production mechanisms and NIs yields, a comparative study on different carbons materials was performed. Measured NIDFs show the same shape at room temperature. This indicates that the mechanisms involved in the NI production and the contribution of these mechanisms in the NIDF are the same for all materials. The best NI yield at low temperature is observed on DLC surface. The highest NI yield for all temperatures is observed on Boron doped diamond (BDD) surface at 400°C.