997 resultados para Nasmyth, James, 1808-1890.


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Actualmente una de las variantes historiográficas más importantes en el estudio de la independencia en América Latina está circunscrita al análisis de la participación política de los grupos populares. En ese sentido, en aquel contexto de guerra y lucha revolucionaria en el Perú, que va desde la crisis hispana de 1808 hasta la independencia definitiva en 1824, esta investigación, a partir de un conjunto de fuentes de archivo, impresos y periódicos diversos, desarrolla las imágenes y representaciones que las elites peruanas construyeron de estos sectores sociales, algunas de las respuestas que estos últimos les infringieron y las múltiples alternativas políticas, que en aquel escenario beligerante, todos estos actores supieron concebir, negociar y utilizar políticamente.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fil: Peretó Rivas, Rubén. Consejo Nacional de Investigaciones Científicas y Técnicas

Relevância:

20.00% 20.00%

Publicador:

Resumo:

An integrated instrument package for measuring and understanding the surface radiation budget of sea ice is presented, along with results from its first deployment. The setup simultaneously measures broadband fluxes of upwelling and downwelling terrestrial and solar radiation (four components separately), spectral fluxes of incident and reflected solar radiation, and supporting data such as air temperature and humidity, surface temperature, and location (GPS), in addition to photographing the sky and observed surface during each measurement. The instruments are mounted on a small sled, allowing measurements of the radiation budget to be made at many locations in the study area to see the effect of small-scale surface processes on the large-scale radiation budget. Such observations have many applications, from calibration and validation of remote sensing products to improving our understanding of surface processes that affect atmosphere-snow-ice interactions and drive feedbacks, ultimately leading to the potential to improve climate modelling of ice-covered regions of the ocean. The photographs, spectral data, and other observations allow for improved analysis of the broadband data. An example of this is shown by using the observations made during a partly cloudy day, which show erratic variations due to passing clouds, and creating a careful estimate of what the radiation budget along the observed line would have been under uniform sky conditions, clear or overcast. Other data from the setup's first deployment, in June 2011 on fast ice near Point Barrow, Alaska, are also shown; these illustrate the rapid changes of the radiation budget during a cold period that led to refreezing and new snow well into the melt season.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Within the Scotia Sea, the axis of the Antarctic Circumpolar Current (ACC) is geographically confined, and sediments therefore contain a record of palaeo-flow speed uncomplicated by ACC axis migration. We outline Holocene and Last Glacial Maximum (LGM) current-controlled sedimentation using data from 3.5-kHz profiles, cores and current meter moorings. Geophysical surveys show areas of erosion and deposition controlled by Neogene basement topography. Deposition occurs in mounded sediment drifts or flatter areas, where 500-1000 m of sediment overlies acoustic basement. 3.5-kHz profiles show parallel, continuous sub-bottom reflectors with highest sedimentation rates in the centre of the drifts, and reflectors converging towards marginal zones of non-deposition. Locally, on the flanks of continental blocks (e.g. South Georgia), downslope processes are dominant. The absence of mudwaves on the sediment drifts may result from the unsteadiness of ACC flow. A core transect from the ACC axis south to the boundary with the Weddell Gyre shows a southward decrease in biogenic content, controlled by the Polar Front and the spring sea-ice edge. Both these features lay farther north at LGM. The cores have been dated by relative abundance of the radiolarian Cycladophora davisiana, and by changes in the biogenic Ba content, a palaeoproductivity indicator. Sedimentation rates range from 3 to 17 cm/ka. The grain size of Holocene sediments shows a coarsening trend from south to north, consistent with strongest bottom-current flow near the ACC axis, though interpretation is complicated by the presence of biogenic grains. Year-long current meter records indicate mean speeds from 7 cm/s in the south to 12 cm/s in the north, with benthic storm frequency increasing northwards. LGM sediments are predominantly terrigenous and show a clearer northward-coarsening trend, with well-sorted silts in the northern Scotia Sea. Assuming a constant terrigenous source, this implies stronger ACC flow at the LGM, contrasting with weaker Weddell Gyre flow deduced from earlier work.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

En este trabajo nos ocuparemos de los debates, entre los ingenieros hidráulicos y entre los políticos, que dieron lugar a diferentes proyectos de solución entre 1890 y 1910, cuando se fueron consolidando las agencias estatales que tendrían intervención en el problema de las inundaciones. Nuestro objetivo es estudiar los recorridos intelectuales y burocráticos que permitieron delinear los proyectos de solución a los problemas hídricos, las investigaciones llevadas a cabo para su concreción y la relación entre la toma de decisiones y los cambios en la política y la economía bonaerense. De esta manera, realizaremos una descripción de las agencias estatales encargadas de la gestión de los recursos hídricos en la provincia de Buenos Aires y esbozaremos una caracterización de los funcionarios actuantes y su relación con el nivel político de la burocracia provincial

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fil: Amícola, José. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación. Instituto de Investigaciones en Humanidades y Ciencias Sociales (UNLP-CONICET); Argentina.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fil: Kiriacópulos, Yamila. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fil: Bordagaray, María Eugenia. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fil: Calvente, Sofía Beatriz. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.