Variabilidade temporal no transporte de sedimentos no rio Ivaí - Paraná (1977-2007)

This paper evaluates the behavior of suspended sediment load of the river Ivaí over a period of 32 years measured by the station further downstream the river (Novo Porto Taquara). The most suitable parameters for this assessment were the annual discharge of suspended sediment and water obtained from SUDERSA. The relationship between the concentration of suspended sediment and discharge of water had not a very good correlation (R 2 = 0,56) and hysteresis effect is quite clear. The justification for this behavior is given by the heterogeneity of the hydrological regime and basin occupation. There were no significant changes in annual flows which have remained the same during the study period. Already the discharge of suspended sediment showed a small gradual decline in which the end of the period (2007), the river carries less than 0.65 Mton at the beginning (1977). This reduction in suspended sediment transported is probably due to changes in soil management for agriculture.

Estimativa de alguns parâmetros de transporte de contaminantes para solos Brasileiros

This paper introduces an indirect estimate for the coefficients of distribution, hydrodynamic dispersion and retardation for contaminants commonly encountered in sanitary landfills and their liners, such as Cu2+ and K+; this estimate is based on the relationship between concentration and certain physical characteristics of typical Brazilian soils. The results of previous studies investigating the migration of contaminants were used to develop mathematical expressions from multiple non-linear regressions. Using minimal squares regression, this transport was linked to various combinations of contaminant concentration and both structural and textural characteristics of the porous medium. Various combinations of characteristics and concentrations were investigated, with a mathematical expression obtained for each. The relationship between percentage of clay and the contaminant content proved to be the most closely correlated with actual transport parameters, with coefficients close to one.

Determinantes de la inversión en el sector petróleo y gas en la Argentina

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Impacto de la reforma económica sobre las inversiones de la industria eléctrica en México: el regreso del capital privado como palanca de desarrollo

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Crisis bancarias: causas, costos, duración, efectos y opciones de política

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Planificación del transporte en países de América Latina

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Formulación de proyectos agropecuarios, extractivos, de transporte y energético

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Congelação de espermatozoides epididimários de gatos utilizando o diluidor Botu-crio® após refrigeração por 24 h em contêiner de transporte de sêmen Botu-tainer®

The possibilities of using the sperm collected from the epididymis have been widely used because the fertilizing capacity sperm preservation and the possibility of using it for wild cats. But in the process of cryopreservation, some studies show a decrease in the quality of the sperm when left under cooling before frozen for some time. This study aimed to assess the quality of the epididymal sperm obtained from domestic cats after cryopreservation using a diluent based on egg yolk and glycerol (Botu-crio®), comparing the morphofunctional characteristics after cooling for 24 hours in a container of semen transport (Botu-tainer®). We use eight cats submitted to elective orchiectomy, aging from eight months, without racial determination, and good nutritional status. These sperm characteristics were: motility, vigor, concentration, membrane integrity and morphology. It has been found, after statistical analysis, that the container of semen was able to maintain sperm viability, even for 24h. We also observed a significant decrease on all parameters after frozen, consequential, probably to thermal stress that occurs in processing. However, the percentage of membrane integrity after thawing shows good employability of the Botu-crio®, which viability is possible to perform in vitro fertilization, requiring higher ratings.

Planificación del transporte en los países del Cono Sur: evaluación comparativa de las metodologías aplicadas en cinco países

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Precios sombra en los estudios integrados de transporte: la experiencia argentina

Explica la significacion de los precios sombra en la evaluacion de proyectos en el contexto de America Latina y resume algunos metodos para derivarlos, citando el caso de la primera fase del Plan nacional de Transporte de Argentina.

Institucionalización de la planificación de transporte: la experiencia de la República Federativa del Brasil

Describe la Empresa Brasilena del Planeamiento de Transporte (GEIPOT), sus origenes, evolucion historica, caracteristicas, organizacion, recursos humanos, actividades, y clientes.

Papel de los estudios integrados en la planificación del transporte: la experiencia uruguaya

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Coordinación del transporte vial con los demas medios de transporte internacional en Sudamérica = Co-ordination of road transport with other international transport media in South America

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