Larvas de Boophilus microplus, que eclodiram imersas em água, eram colocadas sobre orelhas de coelhos de 3 em 3 dias. A maior porcentagem de ninfas foi obtida no terceiro dia com 31,4%, enquanto que a menor 21 dias, com 9,5%. Em outror experimento larvas de Boophilus microplus eclodidas em imersão, mantidas nesta condição por 9 dias e depois colocadas em desidratação a temperatura de 24,2 grau C e umidade relativa de 76%, reduziram seu peso em 21,9% nas primeiras 24 horas. Estas larvas, quando colocadas em orelhas de coelhos, deram 22,9% de ninfas. Entretanto, o máximo de ninfas (40,4%) se obtinha quando as larvas eram desidratadas durante 48 horas.

Neste trabalho foi avaliada a distribuição de água e de potássio aplicados por um protótipo aplicador de produtos químicos que opera de forma acoplada a um pivô central, utilizando-se da mobilidade da torre como meio de deslocamento para aplicação de calda através de microaspersores. Concluiu-se que o protótipo apresentou boa uniformidade de distribuição de água, com variações próximas aos microaspersores, devido a respingos causados pelos impactos dos jatos de água no corpo dos mesmos e que a injeção de solução de cloreto de potássio proporcionou concentração uniforme de potássio na solução emitida pelos microaspersores.

Fil: Cornaglia, Carolina Andrea. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina. | El objetivo general de la Tesis es contribuir a desarrollar un sistema catalítico eficiente para la purificación de hidrógeno mediante la reacción del gas de agua (RGA), garantizando en el permeado del reactor de membrana (RM) una concentración de CO menor a las 10 ppm. Para ello se actuó en dos frentes: i) Estudio comparativo de Rh y Pt soportado sobre La2O3 y La2O3.SiO2. ii) Minimización y optimización de la carga de metal noble teniendo como objetivo maximizar la actividad catalítica por gramo de metal noble sin afectar la estabilidad ni formar metano. Se estudió la relación existente entre las características fisicoquímicas de los catalizadores y su comportamiento catalítico (actividad, selectividad y durabilidad) empleando diversas técnicas instrumentales de caracterización. Las mejores formulaciones fueron finalmente ensayadas en el reactor de membrana cuyo comportamiento fue comparado con sistemas similares reportados en la literatura. En el cumplimiento del objetivo general además, se cubrieron los siguientes objetivos complementarios: Minucioso estudio cinético de la RGA catalizada por una formulación estable de metal noble soportado. Dilucidación de las causas de desactivación del Rh/La2O3 que había resultado inicialmente más activo que la muy estable formulación Rh/La2O3.SiO2. Simulación del comportamiento del RM utilizando un modelo unidimensional heterogéneo que incluye el efecto de limitaciones difusivas externas. Estudio del efecto de la presión en el sistema catalizador-membrana empleando una de las formulaciones más activas y estables desarrolladas en la Tesis. Estudio del comportamiento del sistema catalizador-membrana utilizando una alimentación de composición similar a la salida de un reformador de bioetanol. | The objective of the Thesis is contribute to developing an efficient catalytic system for hydrogen purification through the water gas shift reaction (WGSR) in a membrane reactor (MR), in order to obtain a permeate stream with a CO content lower than 10 ppm. For this objective, two issues were dealt with: i) A comparative study of Rh and Pt catalysts supported over La2O3 and La2O3.SiO2, respectively. ii) Minimization and optimization of the noble metal loading, in order to maximize the catalytic activity per gram of noble metal not affecting the stability and selectivity. The catalytic phisicochemical properties were correlated with the catalytic behavior (activity, selectivity and stability) employing different charaterization tecnhiques. The best formulations were finally evaluated in the membrane reactor. Other complementary tasks were also performed: A detailed kinetic study of the WGSR; a study of deactivation for the Rh/La2O3 (initially more active than the Rh/La2O3.SiO2 formulation); a MR simulation using a unidimensional heterogeneous model and including external difussional limitations; a study of the pressure effect over the catalyst-membrane system employing one of the most active and stables formulations developed during the Thesis; a study of the catalyst-membrane system behavior feeding a stream with a composition similar to the outlet of an ethanol reformer. | Consejo Nacional de Investigaciones Científicas y Técnicas | Agencia Nacional de Promoción Científica yTecnológica | Universidad Nacional del Litoral

A field experiment was carried out in southern Xinjiang, China, to reveal soil-water flow pattern beneath a combined plastic-mulch (film) and drip-irrigation system using brackish water. The soil-water flow system (SWFS) was characterized from soil surface to the water table based on observed spatio-temporal distribution of total soil-water potential, water content and electric conductivity. Root suction provided a strong inner sink. The results indicated that SWFS determined the soil salinity and moisture distribution. Drip-irrigation events could leach excess salts from the root zone and provide soil conditions with a tolerable salinity level that supports the growth of cotton. High-salinity strips were formed along the wetting front and at the bare soil surface. Hydrogeology conditions, irrigation regime, climate, plant growth and use of mulch would affect potential sources and sinks, boundary conditions and the size of the SWFS. At depth 0–60 cm, the soil salinity at the end of the irrigation season was 1.9 times that at the beginning. Beneath the mulch cover, the soil-water content in the ‘wide rows’ zone (55 cm between the two rows with no drip line) was higher than that in the ‘narrow rows’ zone (15 cm between the two rows with a drip line) due to the strong root-water uptake. The downward water flow below the divergent curved surface of zero flux before irrigation, and the water-table fluctuation with irrigation events, indicated that excessive irrigation occurred.

The production of monoacylglycerol rich in polyunsaturated fatty acids (PUFA) via enzymatic glycerolysis of sardine oil in a homogeneous system was evaluated. Reactions were conducted in two different tert-alcohols. Based on the phase equilibrium data, the amount of solvent added to create a homogeneous system has been calculated and optimized. The immobilized lipase used in this work was Lipozyme RM IM from Rhizomucor miehei, a water dependent lipase. The amount of water added as well as other reaction parameters were studied to evaluate the optimum conditions for monoacylglycerol obtencion. An initial reactant mole ratio glycerol to sardine oil 3:1, 12 wt% of water based on glycerol content and 10 wt% of lipase loading (based on weight of reactants), achieved a MAG yield of around 70%, with nearly 28 wt% PUFA, with low free fatty acid content (lower than 18 wt%). | En este trabajo se ha estudiado la producción de monoacilglicéridos, ricos en ácidos grasos poliinsaturados (AGPI), mediante glicerolisis enzimática de aceite de sardina. La reacción se ha llevado a cabo en dos tert-alcoholes para conseguir de esta forma un medio homogéneo de reacción. La cantidad de disolvente añadida al medio de reacción se ha optimizado y calculado en base al equilibrio de fases de los componentes del sistema. La lipasa empleada como biocatalizador ha sido la enzima inmovilizada Lipozyme RM IM de Rhizomucor miehei, una lipasa dependiente de agua. Se ha estudiado el efecto de distintos parámetros cinéticos, así como de la cantidad de agua añadida al medio de reacción, en la producción de monoacilglicéridos. De los resultados obtenidos, se puede concluir que, para una relación molar inicial de reactantes glicerol:aceite de sardina de 3:1, un 12 % en peso de agua en base al glicerol y un 10 % en peso de lipasa, en base al peso de reactantes; se puede llegar a conseguir un rendimiento en monoacilglicéridos alrededor del 70 % en peso, con casi un 28 % en peso de AGPI y un bajo contenido en ácidos grasos libres (menor del 18 % en peso). | Spanish Government through MINECO and the European Regional Development Fund (ERDF) for financial support to the project CTQ2012-39131-C02-01. They wish to thank Novozymes A/S for kindly supplying the enzymes. RM acknowledges MINECO for an FPI grant (reference BES-2013-063937).

Modelling tools are necessary for quantitative assessment of groundwater-dependent systems such as interacting groundwater aquifers and lakes. Numerical groundwater models supplemented by stream and lake submodels are the best available tools for testing the conceptual relation of surface water to groundwater, for identifying gaps in the amount and quality of data, and for better understanding the sustainability of a groundwater-lake system in the presence of stresses. Models are of particular interest when applied to an infrequently studied geological context that is subject to specific vulnerabilities and patterns of interaction. Volcanic lakes are one setting where flow models serve to extend current conceptual and practical understanding. In this study, a groundwater/surface-water flow model is presented for the flow-through Bracciano deep caldera lake located near Rome, Italy. The steady-state model quantifies and tests the existing conceptual understanding of the system by taking account of all sources and sinks, and by calibration of key parameters to head and flow data. A transient version of the model demonstrates the response of the system to dry and wet years and to anthropogenic stresses. Although precipitation is the dominant source of water overall for the lake, a major finding of this study is that the groundwater inflow to the lake can buffer fluctuations in lake-water level and reduce lake-level declines, especially during shorter periods of dry conditions.