Influence of hydraulic conditions over dunes on the distribution of the benthic macroinvertebrates in a large sand bed river

This study aims to relate the flow structure over mobile dunes recorded on the channel bed of the Paraná River (Argentina) with the spatial distribution of the benthic macroinvertebrates. The following main conclusions have been obtained: (1) the dunes found in the active channel could be considered as hydraulic biotopes at a mesohabitat scale: the bed forms in the thalweg region are subjected to higher shear stresses with low benthic densities; (2) differences in benthic densities were also recorded at within-dunes microhabitat scales: the largest densities were found in the dune troughs where small bed shear stresses occur and minimum densities on the low stoss side of dunes where turbulent agitation near the bottom strongly disturb the bed particles; (3) superimposed dunes on larger dunes may be considered as another microhabitat of still smaller dimensions. Summarizing, multiscale approaches are needed if a comprehensive understanding linking hydrodynamics and morphodynamics processes with benthic ecology is intended.Fil: Amsler, Mario Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Blettler, Martin Cesar Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Ezcurra, Ines Delia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentin

The assessment of a smart anticorrosive coating by the electrochemical noise technique

Zinc phosphate and related compounds are convenient replacements for chromates. However, more eco-compatible pigments are being investigated. The objective of this research was to develop a modified zeolitic rock which is intended to replace phosphate pigments in anticorrosive paints. The modified zeolitic rock was obtained by grinding the rock followed with ionic exchange with molybdenyl ions. This “composite” has an intelligent behavior because molybdenum compounds are leached from the zeolite particle by corrodent species. The anticorrosive properties of this zeolitic rock were studied by electrochemical techniques, employing inhibitor suspensions, and formulating anticorrosive coatings. Coatings performance was evaluated by accelerated tests (humidity chamber and salt spray) and electrochemical noise measurements (ENM). Electrochemical noise data were analyzed in the time domain. The noise resistance (Rn) was compared, as far as possible, with the polarization resistance. It was demonstrated that zinc phosphate content could be reduced to one-third with respect to the recommended value in the literature. The electrochemical noise technique allowed to differentiate the anticorrosive performance of the different coatings formulated in this research.Centro de Investigación y Desarrollo en Tecnología de Pintura

The assessment of a smart anticorrosive coating by the electrochemical noise technique

Zinc phosphate and related compounds are convenient replacements for chromates. However, more eco-compatible pigments are being investigated. The objective of this research was to develop a modified zeolitic rock which is intended to replace phosphate pigments in anticorrosive paints. The modified zeolitic rock was obtained by grinding the rock followed with ionic exchange with molybdenyl ions. This “composite” has an intelligent behavior because molybdenum compounds are leached from the zeolite particle by corrodent species. The anticorrosive properties of this zeolitic rock were studied by electrochemical techniques, employing inhibitor suspensions, and formulating anticorrosive coatings. Coatings performance was evaluated by accelerated tests (humidity chamber and salt spray) and electrochemical noise measurements (ENM). Electrochemical noise data were analyzed in the time domain. The noise resistance (Rn) was compared, as far as possible, with the polarization resistance. It was demonstrated that zinc phosphate content could be reduced to one-third with respect to the recommended value in the literature. The electrochemical noise technique allowed to differentiate the anticorrosive performance of the different coatings formulated in this research.Centro de Investigación y Desarrollo en Tecnología de Pintura

Preparation, Characterisation, and Photocatalytic Behaviour of Co-TiO2 with Visible Light Response

The preparation of cobalt-modifiedTiO2(Co-TiO2) was carried out by the incipient impregnation method starting from commercialTiO2(Degussa, P-25) and cobalt acetate. XPS data show that cobalt is incorporated as divalent ion, and it is likely present within few subsurface layers. No appreciable change in structural-morphologic properties, such as surface area and anatase/rutile phase ratio, was observed. Conversely, Co addition brings about conspicuous changes in the point of zero charge and in surface polarity. Diffuse reflectance spectra feature a red shift in light absorption that is dependent on the amount of cobalt. The influence of cobalt addition on the performance ofTiO2as a photocatalyst in the degradation of 4-chlorophenol and Bisphenol A is investigated. The results show that the modified oxide presents a higher photoactivity both for illumination with UV-visible (λ>360 nm) and visible light (λ>420 nm;λ>450 nm), and that this enhancement depends on the amount of the added species and on the final thermal treatment in the preparation step. We also show that Co-TiO2is a more active catalyst than pureTiO2for the reduction ofO2in the dark, which is an important reaction in the overall photocatalytic processes

Análisis socio-técnico del desarrollo de la Cañera INTA: como tecnología de inclusión

En 2004 es sancionada la Ley 6.253 posteriormente modificada por la Ley 7.459, la cual prohíbe quemar caña de azúcar en todo el territorio de la Provincia de Tucumán. Esto impactó fuertemente en pequeños y medianos productores quienes mediante el uso del fuego evitan el pelado manual realizando una cosecha semi-mecanizada. Esta situación generó un acercamiento de dichos cañeros al INTA, Institución en la que plantearon sus inquietudes respecto a las dificultades de realizar dicha tarea sin practicar la quema. Como respuesta al problema-solución, la Institución construye la Cañera-INTA. El objetivo del presente trabajo es abordar el análisis de este caso, mediante herramientas que estudien los cambios políticos y sociales que llevaron al desarrollo de la Cañera-INTA, haciendo hincapié en cómo fueron variando los mapas de alianzas entre los actores a lo largo de las diferentes etapas de este proceso.Instituto de EconomíaFil: Jaldo Alvaro, Delia Mariana. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigación en Ciencias Políticas, Económicas y Sociales. Instituto de Economía; ArgentinaFil: Ortiz, Joaquin Mario. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Famaillá; Argentin

Neutral and adaptive variation in the most widely distributed native tree species in Patagonia: on the way to defining provenance regions for Nothofagus pumilio

In our ongoing project, we aim to define Provenance Regions (PR) for the species along its distribution range in Argentina, from 36º S to 55º S. We propose the combination of neutral genetic variation with quantitative information generated from common garden provenance and progeny genetic trials.Estación Experimental Agropecuaria BarilocheFil: Mattera, María Gabriela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estacion Experimental Agropecuaria Bariloche; ArgentinaFil: Torres, Ana Delia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estacion Experimental Agropecuaria Bariloche; ArgentinaFil: Soliani, Carolina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Aparicio, Alejandro Gabriel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estacion Experimental Agropecuaria Bariloche; ArgentinaFil: Marchelli, Paula. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Pastorino, Mario Juan. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; Argentin

Propuesta de organización del Fondo Documental Acumulado de la Dirección de Tránsito y Transporte de Floridablanca-Santander, 1988-1995

Spa: El trabajo presenta la propuesta de organización del Fondo Documental Acumulado de la Dirección de Tránsito y Transporte de Florida Blanca Santander, que permite recuperar la información y salvaguardarla, permitiendo que los usuarios accedan a ella de manera rápida y efectiva, y que la entidad reconozca su patrimonio documental.Bibliografía y webgrafía: páginas 51-53.EspecializaciónEspecialista en Archivistic

Improving food production from livestock

This chapter is made accessible with permission from the Worldwatch Institute. Purchase the full report online at: http://www.nourishingtheplanet.or