A 4300 m de altura aproximadamente a 15 km al Este de la ciudad de Potosí, se tiene el emplazamiento del batolito del K’ari K’ari con un área de 450 km2. Los depósitos sedimentarios glaciares producto de la erosión y meteorización de los materiales ígneos dieron origen a la formación de diferentes valles glaciales conformado en su mayor parte por material morrénico y eólico. Circunda a estos valles elevaciones que sobrepasan los 5000 m de altura donde la recarga producto de la precipitación pluvial aumenta hasta mas de 1000 mm/a, además de tener la presencia de lagunas, que por efecto de rebalse, parte de estas aguas infiltran recargando el acuífero en las morrenas, formando de esta manera grandes recursos hídricos subterráneos en depósitos morrénicos.Los resultados obtenidos de las investigaciones geofísicas e hidrogeológicas muestran la importancia de explotar agua subterránea como fuente alternativa en materiales morrénicos y a bajos costos de explotación. Los resultados de las pruebas hidráulicas demuestran que son acuíferos altamente permeables con capacidad de recarga anual alta.

This article presents the report on a research developed in the seven palm oil mills of the central oil palm zone of Colombia. The objectives of the study were to analyze, through statistical tools, the historical information during 1998, on the incidence and correlation of the different variables measured during the clarification process (dilutions, heavy sludge, light sludge, oil at the exit of the clarifiers, recovered oil of the sludge removers, dry solids without oil, etc.) with the loss of oil at the exit of the sludge removers. Important correlation was found between the presence of light sludge at the exit of the clarifier and the losses of oil on dry non-fatty base in the discharges of the sludge removers. It was also found that the percentage of oil in clarification effluents had a lower incidence in the loses in centrifuges, than the sludge previously mentioned. Some important correlations of other variables and important differences between two sub-zones of the central Colombian palm zone are also shown. | Se presenta el informe sobre las investigaciones realizadas en las siete plantas de beneficio de la zona palmera central de Colombia. Los objetivos del estudio fueron analizar, mediante herramientas estadísticas, la información histórica, durante 1998, sobre la incidencia y correlaciones de las diferentes variables que se miden en la clarificación (diluciones, lodos pesados, lodos ligeros, aceite a la salida de los clarificadores, aceite recuperado en las deslodadoras, sólidos secos no aceitosos, etc.) con la pérdida de aceite a la salida de las deslodadoras. Se encontraron correlaciones significativamente estadísticas entre la presencia de lodos ligeros a la salida del clarificador y las pérdidas de aceite sobre base seca no aceitosa en las descargas de las deslodadoras. También se encontró que el porcentaje volumétrico de aceite en los efluentes de clarificación tenía menor incidencia en las pérdidas en las centrífugas que los lodos ligeros antes mencionados. Se muestran correlaciones significativas de otras variables y diferencias importantes entre dos subzonas de la Zona Central.

O presente experimento teve como objetivo comparar valores de velocidade de infiltração de água no solo, determinados por duas metodologias distintas: infiltrômetro de anéis concêntricos (IANC) e infiltrômetro de aspersores (IAS). Em uma parcela de controle com dimensões de 12 x 12 m obtiveram-se, pela metodologia do IANC, 36 curvas de infiltração de água no solo e a velocidade básica de infiltração de água nesta área, através da metodologia do IAS. Comparando-se os resultados obtidos em ambas as metodologias, constatou-se que a média aritmética dos valores obtidos pela metodologia do IANC superestimou a velocidade de infiltração de água no solo, obtida pela metodologia do IAS, e que somente os valores da média geométrica e da moda obtidas com o IANC se aproximaram da velocidade de infiltração obtida com o IAS.<br>The objective of this paper was to compare values of water infiltration rate in soil, obtained with two distinct methodologies: cylinder infiltrometer and sprinkler infiltrometer. Thirty six infiltration rate curves were obtained using the cylinder infiltrometer methodology and four infiltration rate curves using a sprinkler infiltrometer. It was observed that the arithmetic mean of results from the cylinder infiltrometer methodology obtained overestimated the infiltration rate obtained with sprinkler infiltrometer and that the geometric mean and mode of the results obtained with cylinder infiltrometer approached the velocity of infiltration of water in soil obtained with the sprinkler infiltrometer.

Water soluble pentosans (WSP) from doughs and breads made with different enzyme preparations are characterized according to extraction yield, sugar composition, xylose/arabinose ratio and molecular weight (MW) distribution. Extraction yield was greater for dough than for bread samples, ranging from 0.94 to 1.64%, but bread extracts had a higher purity. Percent of pentoses in purified WSP was greater in pentosanase supplemented samples (28-55%) than in control and amylase containing samples (23-32%). Major sugars were xylose and arabinose, but glucose and mannose also appeared in the extracts. The xylose/arabinose (Xyl/Ara) ratio was 1.3-1.6 and underwent small changes during processing. Enzyme addition caused an increase in Xyl/Ara ratio, attributable to a debranching of arabinoxylans (AX) with higher degree of Ara substitution by arabinofuranosidase. Addition of pentosanases had a significant effect in increasing WSP with MW over 39 000, whereas those of low MW changed only slightly. MW distribution depended on enzyme source, and whereas some enzymes showed activity during fermentation others increased their activity during baking. No synergistic effects were observed in studied variables due to the combination of amylases with pentosanases. Protein in WSP extracts eluted together with ferulic acid suggesting they were linked, but not associated with a determined carbohydrate fraction.

A recente Lei n° 9.433/97 e as respectivas leis estaduais criam a possibilidade de adoção de um novo modelo de gestão de recursos hídricos no Brasil. Entre as inovações está a consideração de que a gestão desses recursos deve ser participativa e descentralizada onde poder público, usuários e comunidades discutem e indicam as soluções para os problemas. A nova legislação entende que a água é recurso escasso e, portanto, com valor econômico e sugere a cobrança pelo seu uso como um dos instrumentos de gestão. Há muitos questionamentos, entretanto, sobre a aplicação da cobrança pelo uso da água no Brasil. O objetivo central desta pesquisa é conceber alternativas de cobrança e simular a sua aplicação em uma bacia hidrográfica brasileira, analisando os impactos causados e refletindo sobre as possibilidades de aprimoramentos. Sendo a cobrança um, entre tantos outros instrumentos de gestão, é objetivo do trabalho, também, pesquisar sobre a atuação de outros instrumentos. Simula-se a outorga dos direitos de uso da água (prevista na nova legislação de recursos hídricos) e analisam-se o licenciamento ambiental e o enquadramento dos corpos d’água em classes de usos preponderantes (mecanismos já aplicados pelos órgãos ambientais no Brasil). A bacia do rio Pirapama, na Região Metropolitana do Recife, congrega diversos problemas quantitativos e qualitativos referentes a recursos hídricos e foi escolhida como caso de estudo. Os resultados e as análises da pesquisa mostram que, se criteriosamente aplicados, os instrumentos simulados podem contribuir para o disciplinamento do uso da água na bacia. | The Brazilian Federal Law n° 9.433/97, as well as the Brazilian States ones, allow adoption of a new water resources management model in Brazil. This model considers that water management should be descentralized and involve participation by the Government, users and local communities. The new legislation establishes water as a scarce resource, which has an economic value. Charges on the use of water resources are considered as a management instrument. However, there are many questions related to the application of such charges in Brazil. This thesis proposes some schemes for water charges and simulates their application to a Brazilian river basin. Other management instruments are also studied as the award of water use rights, the environment licenses and the classification of water bodies according to their principal uses. The Pirapama River Basin in Recife Metropolitan Region has problems related to water quantity and quality. This basin was chosen as the case study. The results and analysis show that those instruments, if adequately implemented, help achieving efficient use of water.

Recientemente se ha aprobado la reforma de la Ley de aguas, introduciéndose por primera vez en nuestro país la posibilidad de crear mercados de agua. Con ello se confía en promover una distribución más eficiente de este recurso escaso. Este trabajo analiza el impacto que tendría la hipotética aplicación de estos mercados a través de técnicas multicriterio. Los resultados de simulación permiten cuantificar el volumen de agua intercambiado entre los agentes para cada precio de agua. Estos resultados ponen de manifiesto cómo esta política descentralizada de asignación de recursos hídricos no supondría una mejora de la eficiencia del agua, ni desde una perspectiva económica (renta agraria) ni social (empleo generado)

This article presents the report on a research developed in the seven palm oil mills of the central oil palm zone of Colombia. The objectives of the study were to analyze, through statistical tools, the historical information during 1998, on the incidence and correlation of the different variables measured during the clarification process (dilutions, heavy sludge, light sludge, oil at the exit of the clarifiers, recovered oil of the sludge removers, dry solids without oil, etc.) with the loss of oil at the exit of the sludge removers. Important correlation was found between the presence of light sludge at the exit of the clarifier and the losses of oil on dry non-fatty base in the discharges of the sludge removers. It was also found that the percentage of oil in clarification effluents had a lower incidence in the loses in centrifuges, than the sludge previously mentioned. Some important correlations of other variables and important differences between two sub-zones of the central Colombian palm zone are also shown. | Se presenta el informe sobre las investigaciones realizadas en las siete plantas de beneficio de la zona palmera central de Colombia. Los objetivos del estudio fueron analizar, mediante herramientas estadísticas, la información histórica, durante 1998, sobre la incidencia y correlaciones de las diferentes variables que se miden en la clarificación (diluciones, lodos pesados, lodos ligeros, aceite a la salida de los clarificadores, aceite recuperado en las deslodadoras, sólidos secos no aceitosos, etc.) con la pérdida de aceite a la salida de las deslodadoras. Se encontraron correlaciones significativamente estadísticas entre la presencia de lodos ligeros a la salida del clarificador y las pérdidas de aceite sobre base seca no aceitosa en las descargas de las deslodadoras. También se encontró que el porcentaje volumétrico de aceite en los efluentes de clarificación tenía menor incidencia en las pérdidas en las centrífugas que los lodos ligeros antes mencionados. Se muestran correlaciones significativas de otras variables y diferencias importantes entre dos subzonas de la Zona Central.