This study aimed to evaluate, in vitro, the influence of Diode Laser on the evaporation of adhesive systems solvent applied on the dentin. The groups were distributed in relation to the adhesive systems (Adper Single Bond 2, Adper Scotchbond Multi Purpose, Single Bond Universal, Clearfil SE Bond e Optibond All-in-one) and also to the technique for the evaporation of the solvent (air dry stream or Diode Laser). The degree of evaporation (GE) was determined through the measuring of mass loss through the gravimetric method in an analytical digital balance. To do so, a hundred human third molars had cavities class I made of following a pattern with the diamond burs # 4054 (KG Soresen, Barueri, SP, Brasil), under refrigeration, on which 10 μL were dispensed of each adhesive system, then one of the both techniques of solvent evaporation was applied: air dry stream, from a distance of 10 cm for each 5 seconds (control technique) or Diode Laser irradiated in a continuous mode perpendicularly and from a distance of 1 cm, in the power of 3 W in the interval of 30 seconds (experimental technique). To each one of the adhesive systems and to each one of the evaporation techniques ten monitoring repetitions were realized (n=10). Regarding the experimental technique, the measurements were realized from 5 to 5 seconds, up to 30 seconds. The variation between the initial mass (mi) and the final mass (mf) of the samples, respectively, before and after the application methods of evaporation proposed were turned into GE, by using the following equation: (mi-mf/mi)x100. In this way, to each time interval (5, 10, 15, 20, 25 and 30 seconds) it happened a calculated GE outcome. Those values were submitted to variance analysis (ANOVA) of two factors and Tukey s test as well. To the comparison between both of the evaporation techniques in each adhesive system a t-student test (α=5%) was realized. Basing on the obtained values of the GE, verified on the current study, it is possible to conclude that the irradiation with Diode Laser was capable of inducing the solvent evaporation of the tested adhesive systems, being superior to the control technique when used in the time of 30 seconds, excepted to the Optibond-all-in-one adhesive system. / Este estudo objetivou avaliar, in vitro, a influência do Laser de Diodo sobre a evaporação do solvente de sistemas adesivos aplicados sobre dentina. Os grupos foram distribuídos em função dos sistemas adesivos (Adper Single Bond 2, Adper Scotchbond Multi Purpose, Single Bond Universal, Clearfil SE Bond e Optibond All-in-one) e da técnica para a evaporação do solvente (jato de ar ou Laser de Diodo). O grau de evaporação (GE) foi determinado através da mensuração da perda de massa pelo método gravimétrico. Para tal, 100 terceiros molares humanos tiveram cavidades classe I confeccionadas de forma padronizada com ponta diamantada em alta rotação (# 4054, KG Soresen, Barueri, SP, Brasil), sob refrigeração, nas quais foi dispensado 10 μL de cada sistema adesivo, seguido da aplicação de uma das técnicas de evaporação do solvente: jato de ar a uma distância de 10 cm por 5 segundos (técnica controle) ou Laser de Diodo irradiado em modo contínuo, perpendicularmente e a uma distância de 1 cm, na potência de 3W no tempo de 30 segundos (técnica experimental). Para cada um dos sistemas adesivos e para cada uma das técnicas de evaporação foram realizadas dez repetições de monitoramento (n=10). Para a técnica experimental as mensurações foram realizadas de 5 em 5 segundos, até 30 segundos. A variação entre massa inicial (mi) e final (mf) das amostras, respectivamente, antes e após a aplicação dos protocolos de evaporação propostos, foram transformadas em GE aplicando-se a seguinte equação: (mi-mf/mi)x100. Portanto, para cada intervalo de tempo, 5, 10, 15, 20, 25 e 30 segundos, houve um desfecho GE calculado. Os resultados foram submetidos à análise de variância (ANOVA) de dois fatores e teste de Tukey. Para comparação entre as técnicas de evaporação em cada sistema adesivo foi utilizado teste t-student (α = 5%).Com base nos valores obtidos do GE verificados no presente estudo, o laser provocou maior evaporação do solvente quando comparado ao Jato de ar, no tempo de 30 segundos, exceto para o sistema adesivo acetonado. Desta forma, a irradiação com Laser de Diodo foi capaz de provocar a evaporação do solvente dos sistemas adesivos testados, sendo superior à técnica controle quando utilizada no tempo de 30 segundos, exceto para o sistema adesivo Optibond-all-in-one.

L’application aux procédés agroalimentaires des approches d'écoconception combinant modélisation et optimisation multiobjectif est freinée par un manque de modèles de procédé intégrant les caractéristiques du produit. Ce travail consiste à développer un cadre méthodologique d'écoconception de procédés agroalimentaires combinant modélisation et optimisation, avec pour support l'exemple du procédé d'évaporation du lait. Le procédé est modélisé à l’aide d’un simulateur de procédés commercial, auquel sont intégrés des modèles de propriétés du produit et de coefficient d'échange sélectionnés dans la littérature. Le nettoyage est pris en compte à l’aide d’un outil de calcul des inventaires d'une séquence de nettoyage en place. Des critères économiques et environnementaux sont calculés pour analyser les solutions de conception du procédé.L'optimisation multiobjectif est réalisée à l'aide d'un algorithme génétique, et une méthode d'aide à la décision permet d'identifier les meilleures solutions de compromis. Les potentialités du cadre méthodologique sont illustrées dans trois études d’écoconception. Les perspectives de ce travail portent sur l’écoconception de la production de poudre de lait incluant des opérations à membranes et du séchage, l’utilisation de méthodes d’intégration énergétique, et la prise en compte de la qualité du produit.L'optimisation multiobjectif est réalisée à l'aide d'un algorithme génétique, et une méthode d'aide à la décision permet d'identifier les meilleures solutions de compromis. Les potentialités du cadre méthodologique sont illustrées dans tro / The application of eco-design approaches to food processes is yet hampered by a lack of process models which incorporate product attributes. This thesis consists in developing a methodological framework for the eco-design of food processes, which combines simulation and multiobjective optimisation. This development is supported by the example of the evaporation of milk. The process is modelled with a commercial process simulator, to which property models of the product and heat transfer coefficient models, selected from the literature, are integrated. Cleaning is taken into account with a simplified tool for the calculation of the inventories of a cleaning-in-place sequence.Economic and environmental criteria are computed, so as to analyse the different design solutions. Multiobjective optimisation is carried out with a genetic algorithm, and a multicriteria decision-making method identifies the solutions which offer the best compromise. The potential of the framework is demonstrated through three eco-design studies. This work paves the way for the eco-design of the milk powder production including membrane operations and drying, the use of energy integration methods, and the integration of product quality.

Cette thèse étudie l'évaporation et l'humidité du sol, deux paramètres clefs du cycle hydrologique et du système climatique.L'évaporation potentielle (ETP) est un paramètre clef pour les modèles hydrologiques et agronomiques qui décrit les interactions entre la surface et l'atmosphère. Il constitue la base des estimations de l'évaporation réelle. Nous avons évalué, à l'échelle globale et pour le climat actuel ainsi que pour les changements attendus, des estimations de l'ETP basées sur des principes physiques ainsi que des approches empiriques. La méthode d'estimation du flux potentiel conseillée par la Food and Agriculture Organization (FAO) montre une sous évaluation par rapport au schéma de surface, ce qui a pu être relié à certaines hypothèses faites. Ceci implique aussi une sensibilité plus faible au changement climatique de la formulation proposée par la FAO. Nous avons aussi constaté que les méthodes empiriques ne représentent pas correctement l'impact du changement climatique sur l'ETP.L'humidité du sol est analysée du point de vue de la température de brillance en Bande-L (TB). Cette mesure du rayonnement émis par la surface dans une bande spectrale sensible à l'eau dans les premiers centimètres du sol, constitue une des pistes pour l'estimation de l'humidité de surface depuis l'espace. Des mesures de TB ont été comparées, au dessus de la Péninsule Ibérique, à des données simulées par deux schémas de surface. Un bon accord a été trouvé entre les observations et les simulations sur l'évolution temporelle des signaux. Par contre, les structures spatiales peuvent être très différentes au cours de l'automne et l'hiver à cause de cycles annuels très contrastés. / This thesis deals with the study of evaporation and soil moisture, t wo main parameters of the hydrological cycle, and thus the climate system. First, potential evaporation (ET P ) is analysed. It is an important input to hydrological and agronomic models, key to describe the interactions between the surface e and the atmosphere, and the basis of most of the estimations of actual evapora tion. Physically-based and empirical methods to estimate ET P are evaluated, at a global scale, under current climate conditions and in a changing climate. The former methods correspond to those implemented in land surface models (LSM) and the Food and Agriculture Organization (F AO) reference evapotranspiration equation. The assumptions made in FAO's method underest imate ET P if compared to LSM methods. They also result in a lower sensitive ty of ET P to climate change. In addition, empirical equations are not able to reproduce the impact of climate change on ET P if compared to that from LSM methods. Soil moisture is the second aim of this thesis. It is treated t hrough the analysis of brightness temperatures (TB). These are a measure of the radiation emitted by the surface , and thus an optimum parameter to use in remote sensing techniques for soi l moisture retrieval. Measured TB from the Soil Moisture and Ocean Salinity (SMOS) mission are compared, over the Iberian Peninsula, to two sets of TB modelled estimates from two LSM. There is a good agreement in the temporal evolution between them. However, discrepancy es are found regarding the spatial structures, which become more evident during fall and winter and are mainly explained by differences in the annual cycle of measured and modelled TB.

Ce travail de thèse s’intéresse à deux zones de l’Atlantique Nord : la région subpolaire et la région subtropicale. Cette large couverture permet d’étudier le cycle de l’eau dans des régions hydrologiquement différentes, où des processus variés rentrent en jeu comme l’évaporation, la convection atmosphérique, la formation des précipitations, le cycle saisonnier de la glace de mer, les apports des rivières et des glaciers, et l’advection des masses d’eau et des masses d’air. Dans la région subtropicale, les variations des compositions isotopiques de la vapeur d’eau sont étudiées afin de comprendre le rôle de l’évaporation et du mélange avec la troposphère libre dans le contrôle de l’humidité et des compositions isotopiques à la surface des océans. Ces données innovantes recueillies in situ principalement au cours de l’été 2012 dans le gyre subtropical de l’Atlantique nord (campagne STRASSE) ont offert l’opportunité d’étudier les processus de fractionnement isotopique lors de l’évaporation océanique et le renouvellement de l’air de la couche limite atmosphérique. Aux plus hautes latitudes de l’océan Atlantique nord, la circulation de surface du gyre subpolaire permet le transfert d’eaux froides et dessalées en provenance de la région (sub)arctique vers l’intérieur du gyre. Dans le cadre de cette thèse, un jeu de données a été recueilli sur la période 2010-2014 et porte plus particulièrement sur la région du courant du Labrador et permet de se poser les questions suivantes : Comment le cycle de la glace de mer affecte la salinité de ces courants dessalés ? Comment évolue l’apport en eau météorique dans un contexte de fonte accélérée des glaciers continentaux ? / This thesis focuses on two regions of the North Atlantic: the subtropical gyre and the subpolar gyre. This large coverage allows an investigation of the water cycle in different hydrological regimes, where various processes take place such as sea ice seasonal cycle, rivers runoff, continental ice melt and advection of air and water masses. In the subtropical region, the variability of the isotopic composition of the water vapor is studied to understand the role of evaporation and mixing with free troposphere in humidity and isotopic compositions at the ocean surface. In particular, new data collected during summer 2012 (STRASSE cruise) gave the opportunity to explore kinetic fractionation processes during oceanic evaporation and air renewal in the atmospheric boundary layer. In the subpolar region, the surface circulation is cyclonic and transfers cold and fresh water from the arctic region to the interior of the subpolar gyre. For this thesis, data were collected between 2010 and 2014 from oceanographic cruises and commercial vessels to study the gyre interior and the main coastal currents carrying water from the arctic to lower latitudes. The study is mainly focused on the Labrador Current. There, isotopic measurements are used to identify the freshwater sources and to consider the following questions: How is the salinity of fresh currents affected by the sea ice formation and melting? How is the contribution of meteoric waters changing in a context of an acceleration of the melting of continental glaciers?

Proprietary mixtures of amines and carboxylic acids are used as volatile corrosion inhibitors (VCIs) for the protection of steel and iron components against atmospheric corrosion during storage and transportation. Interactions between amines and carboxylic acids have been comprehensively reported in the literature. However, little is known about the nature of the vapours these mixtures emit. The present study focused on the development of the evolved gas analysis method which will help in the characterisation of the vapours released by VCIs. In the method, the evaporation of various amine-carboxylic acid binary mixtures was monitored by thermogravimetric analysis (TGA). The nature and the composition of the released vapours was followed by Fourier transform infrared (FTIR) spectroscopy. Mixtures consisting of triethylamine (TEA) and acetic acid were studied as a model compound using TGA-FTIR at 50 °C to validate the TGA-FTIR method. As vaporisation progressed, the composition of the remaining liquid and the emitted vapour converged to a fixed amine content of ca. 27 mol %. This is just above the composition expected for the 1:3 amine: carboxylic acid complex. Mixtures close to this composition also featured the lowest volatility. TGA-FTIR proved to be a convenient method for studying the evaporation of TEA-acetic acid mixtures, and the nature and composition of the released vapours. Amine addition leads to the dissociation of carboxylic acid dimers in favour salt formation. The formation of an ion pair between the amine and carboxylic acid was confirmed by the FTIR spectra of the liquid phase. The resulting amine-carboxylic acid mixtures showed a slow mass loss rate on TGA when compared with the pure amines and pure carboxylic acids. This indicated that the mixtures have low volatility, hence low vapour pressure compared with the pure components. The low vapour pressure of the mixtures was confirmed by the calculated gas permeability values. These values were much higher for the pure amines and the pure carboxylic acids. However, they dropped significantly on amine addition. The strong amine-carboxylic acid interaction is responsible for the suppressed volatility of the mixtures. No interaction is observed between amine and carboxylic acid molecules in the vapour phase at 230 °C. The method developed was applied to characterise the model compounds simulating the amine-carboxylic acid-based volatile corrosion inhibitors. These model systems contained the primary, secondary and tertiary amines (hexylamine, morpholine and triethylamine), as well as carboxylic acids with different chain lengths (acetic, propanoic, hexanoic and octanoic). These systems are usually employed as equimolar mixtures to protect ferrous metals against atmospheric corrosion. The key finding of the study was that the vapours released by such equimolar mixtures initially contain almost exclusively free amine. After prolonged vaporisation, a steady-state “azeotrope”-like composition is approached. It contains excess acid and features impaired corrosion-inhibition efficiencies according to the Skinner test. In part, this behaviour can be attributed to the mismatch between the volatilities of the amine and carboxylic acid constituents. / Thesis (PhD)--University of Pretoria, 2013. / gm2013 / Chemical Engineering / unrestricted

Doctor of Philosophy / Department of Agronomy / Jay M. Ham / Land management practices such as burning and grazing may affect evapotranspiration (ET) and water balance of the tall grass prairie in the Flint Hills of eastern Kansas. Experiments were designed to estimate or measure the water balance of a stock-watering pond, and compare energy balance parameters and ET between grazed and ungrazed prairies. The hydrology of the native tallgrass prairie also was compared with mature stand of eastern red cedar (Juniperus virginiana), a site that was formerly prairie but converted to woodland when prescribed burning was discontinued. Data were collected to encompass the seasonal and yearly changes in weather variability. A host of micrometeorological sensors were used to measure surface atmosphere exchange and water losses, including: eddy covariance towers on prairie and woodland sites, specialized through fall and stem flow equipment at the woodland site, and an instrumentation raft at the stock watering pond. Results of the stock pond study showed that, on average, evaporation accounted for 64% of the water loss, followed by seepage at 31%, cattle use at 3% and transpiration at 2%. Comparisons of grazed and ungrazed areas showed that grazing caused only small, 3 to 6 %, reductions in seasonal ET compared with ungrazed pastures despite large differences in vegetative cover. In the woodland study, the 50-yr-old cedar canopy intercepted 54% of the precipitation received, thus decreasing the amount of precipitation reaching the soil. Evapotranspiration from woodland and prairie sites were similar, but net carbon exchange was greater on the prairie. Thus, the apparent water use efficiency during he summer months was 3 times greater on the prairie. Net radiation at the woodland site was 100 W m-2 higher compared with the prairie. This caused an increase in the woodland sensible heat flux and midday Bowen ratios, yet woodland latent heat flux and ET was similar to the prairie during the study, factors that could affect regional climate. Land management decisions regarding grazing, prescribed burning, and stock pond design will impact the watershed hydrology and productivity of the tallgrass prairie.

>Magister Scientiae - MSc / The objective of this project is to study the production of Li, Be and B isotopes emitted in the interaction of 12C with 12C at incident energies of 200 and 400 MeV.The energies of these produced fragments were measured with a detector telescope consisting of two silicon detectors at the incident energy of 200 MeV while a third silicon detector was added for the measurements at 400 MeV. / South Africa

Magister Scientiae - MSc / This research investigated the nature, source and the spatial variation of the salinity of the water used for irrigation in the urban farming area of Philippi, which lies in the Cape Flats region of the Cape Town Metropolitan Area, South Africa. The irrigation water is mainly drawn from the Cape Flats aquifer, and pumped into ponds for eventual crop irrigation. Water samples were collected in summer and in winter from fifteen selected sites using standard water sampling procedures. Each site consisted of one borehole and one pond. The samples were routinely analyzed for salinity levels, and concentrations of major and minor ions. From the same boreholes and ponds, water was sampled in summer for isotope analysis to assess effects of evaporation on the water quality and salinity. Descriptive statistics were used to display the variation in range of specific ions in order to compare them with the recommended ranges. Geographical Information Systems analysis described the spatial distribution of the salinity across the study area, and hydrogeochemical analysis characterized the various waters and detected similarities between the water samples in the study area and other waters found in the Cape Flats region. In addition, the US salinity diagram classification of irrigation water developed by Richards (1954) was used to assess the current suitability of groundwater and pond water samples collected during the entire sampling period for irrigation activities. The research indicated that the concentrations of some ions such as chloride, nitrate, potassium and sodium exceeded in places in the study area, the target range values set by the Department of Water Affairs and Forestry (DWAF, 1996) and the Food and Agriculture Organization (Ayers and Westcot, 1985). It revealed that borehole and pond water were mostly brackish across the area regarding their total dissolved salts content, and fresh water was only found in the middle part of the study area. The research found that sea water does not intrude into the aquifer of the study area, and the accumulation of salts in groundwater and soil in the study area is mainly due to the agricultural activities and partially due to the natural movement of water through the geological formation of the Cape Flats region. The conceptual model of the occurrence of the salinization process supported these findings. From this investigation it is understood that the groundwater and pond water in the study area were generally suitable for irrigation purposes but they have to be used with caution as the vegetables are classified as sensitive and moderately sensitive to salt according to DWAF Irrigation water guidelines (1996). The quality of these waters was mainly affected by the land use activities. / South Africa

Philosophiae Doctor - PhD / Lying in a rapidly-changing transitional region between nuclei that may behave as spherical vibrators (N ≤ 88) or good rotors (N ≥ 92), the N = 90 isotones present a unique testing ground where new nuclear collective phenomena may be uncovered. As part of a general investigation of collective structures and the coupling of single-particle states to these structures, the 150Sm(12C,4nγγ) and 150Sm(13C,4nγγ) reactions at a beam energy of Elab = 65 MeV were used to study the low and medium spin structure of 158,159Er nuclei below spin 20~. The γ-γ coincidence events were detected in the nine escape-suppressed HPGe Clover detectors using the AFRODITE γ-ray spectrometer at the iThemba Laboratory for Accelerator Based Sciences. DCO ratios and γ-ray polarization measurements were used to establish the spins and parities of newly observed and confirm previously established rotational bands. The observed bands will be discussed in terms of both traditional quadrupole rotational-vibration models and recent predictions of octupole correlations in the N = 90 isotones and neighbouring nuclei. The data obtained will be compared with the spectroscopic systematics of neighbouring nuclei.

L’objectif de ce travail est de réaliser, en premier lieu, une cartographie de l’évapotranspiration à l’échelle régionale et de cerner, en deuxième lieu, un zonage de la déficience d’évaporation dans le bassin versant de Mejerda. Cet objectif s’appuie sur l’amélioration de la performance du modèle de la FAO-PM, et ce par la combinaison de ce modèle avec les données satellitales (MODIS-Terra). Ce travail concerne le bassin versant Mejerda, considéré comme « le château d’eau de la Tunisie », il occupe une place de premier ordre dans la stratégie de mobilisation des ressources en eau et il compte le plus important potentiel agricole.La cartographie de l’évapotranspiration a permis de caractériser la variation spatiale et la variabilité temporelle de ses trois formes (ETP, ETM et ETR) dans le bassin versant Mejerda et de bien distinguer les sous-régions qui n’étaient connues que de manière très empirique. Les fluctuations temporelles sont assez importantes : les valeurs de janvier représentent en moyenne 15% de celles de juillet. La variation spatiale est surtout liée à la carte de l’occupation des sols dans la mesure où la végétation forestière évapore plus que la végétation annuelle et les effets du relief et du site. Les secteurs abrités se caractérisent par un pouvoir évapotranspérant le plus élevé (plaine de Jendouba, dépression de Siliana).Le zonage de la déficience d’évaporation, élaboré par la méthode de classification non supervisée, a montré un nouveau découpage du bassin versant de Mejerda. À ce propos, des sous-régions, légèrement différentes à celles connues la plupart du temps, ont été distingué. C’est le cas de la moyenne Mejerda qui se trouve souvent annexée à la haute Mejerda et une opposition très nette entre les versants sud de la Kroumirie et les versants nord de la Dorsale. Cette configuration est associée à l’effet de l’exposition, le comportement de la végétation et l’état de la teneur en eau du sol. Le zonage de la déficience d’évaporation montre aussi deux gradients du stress hydrique den la végétation. En effet, l’intensité du stress diminue du Nord au Sud de la région et des stations d’altitude vers les fonds de vallées. / The objective of this work is to realize, first, mapping evapotranspiration at the regional level and to identify, secondly, a zoning of the evaporation deficiency in the watershed Mejerda. This objective is based on improving the performance of the FAO model-PM, and the combination of this model with the satellite data (MODIS-Terra). This work concerns the Mejerda watershed, considered "the water tower of Tunisia", it occupies a prime position in the water resource mobilization strategy and it has the largest agricultural potential.Mapping evapotranspiration allowed to characterize the spatial variation and temporal variability of its three forms (FTE ETM and ETR) Mejerda in the watershed and to distinguish between the sub-regions that were known only to a very empirical. Temporal fluctuations are quite important: the values for January averaged 15% of those of July. Spatial variation is mainly related to the land use map since forest vegetation evaporates more than annual vegetation and the effect of terrain and site. Sheltered sectors are characterized by a power évapotranspérant highest (plain of Jendouba, Siliana depression).The zoning of the evaporation deficiency, developed y the clustering method, showed a new division of the watershed Mejerda. In this regard, the sub-regions, slightly different to those known for the most part, have been distinguished. This is the case of Mejerda average that is often attached to high Mejerda and a sharp contrast between the southern slopes of Kroumirie and the northern slopes of the Dorsal. This configuration is associated with the effect of exposure, vegetation behavior and the state of the soil water content. The zoning of the evaporation deficiency also shows two gradients den water stress vegetation. Indeed, the stress intensity decreases from north to south of the region and altitude resorts to valley bottoms