Eficacia de la Webquest como metodología acorde con el nuevo Espacio Europeo de Ecuación Superior : una experiencia universitaria.

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Estudio sobre una iniciativa de adaptar la docencia al Espacio Europeo de Educación Superior.

Analiza las iniciativas de adaptación de la docencia al Espacio Europeo de Educación Superior, con el fin de conocer las demandas y preferencias de los docentes. En primer lugar, se hace un repaso a los planes establecidos para evaluar la calidad de la enseñanza universitaria y se muestra un cuadro en el que se identifican las causas que impiden una renovación metodológica de la universidad. En segundo lugar, se estudia la acogida que adquiere entre el profesorado la primera convocatoria de Proyectos Piloto para la Adaptación de la Docencia al Espacio Europeo de Educación Superior, de la Universidad Nacional de Educación a Distancia. La investigación se aborda desde un estudio de caso, encuadrado en un enfoque descriptivo-interpretativo, que valora los resultados obtenidos en cuanto a la participación del profesorado, la participación por. Resumen tomado de la publicación.

El Prácticum de Pedagogía : una innovadora formación universitaria en el marco de la educación y formación a lo largo de la vida.

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La formación del profesorado de secundaria en Chile : el estado de la cuestión y sus efectos.

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Espacios de reflexión y de actuación asociados al quehacer educativo del profesorado.

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Estudio sobre la formación inicial del profesorado relacionada con la atención a la diversidad.

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Pb-210-Ra-226 and Ra-228-Th-232 systematics in young arc lavas: implications for magma degassing and ascent rates

New data show that island arc rocks have (Pb-210/Ra-226)(o) ratios which range from as low as 0.24 up to 2.88. In contrast, (Ra-22S/Th-232) appears always within error of I suggesting that the large Ra-226-excesses observed in arc rocks were generated more than 30 years ago. This places a maximum estimate on melt ascent velocities of around 4000 m/year and provides further confidence that the Ra-226 excesses reflect deep (source) processes rather than shallow level alteration or seawater contamination. Conversely, partial melting must have occurred more than 30 years prior to eruption. The Pb-210 deficits are most readily explained by protracted magma degassing. Using published numerical models, the data suggest that degassing occurred continuously for periods up to several decades just prior to eruption but no link with eruption periodicity was found. Longer periods are required if degassing is discontinuous, less than 100% efficient or if magma is recharged or stored after degassing. The long durations suggest much of this degassing occurs at depth with implications for the formation of hydrothermal and copper-porphyry systems. A suite of lavas erupted in 1985-1986 from Sangeang Api volcano in the Sunda arc are characterised by deficits of Pb-210 relative to Ra-226 from which 6-8 years of continuous Rn-222 degassing would be inferred from recent numerical models. These data also form a linear (Pb-210)/Pb-(Ra-226)/Pb array which might be interpreted as a 71-year isochron. However, the array passes through the origin suggesting displacement downwards from the equiline in response to degassing and so the slope of the array is inferred not to have any age significance. Simple modelling shows that the range of (Ra-226)/Pb ratios requires thousands of years to develop consistent with differentiation occurring in response to cooling at the base of the crust. Thus, degassing post-dated, and was not responsible for magma differentiation. The formation, migration and extraction of gas bubbles must be extremely efficient in mafic magma whereas the higher viscosity of more siliceous magmas retards the process and can lead to Pb-210 excesses. A possible negative correlation between (Pb-210/Ra-226)(o) and SO2 emission rate requires further testing but may have implications for future eruptions. (C) 2004 Elsevier B.V. All rights reserved.

Tracing pre-eruptive magma degassing using (Pb-210/Ra-226) disequilibria in the volcanic deposits of the 1980-1986 eruption of Mount St. Helens

Disequilibria between Pb-210 and Ra-226 can be used to trace magma degassing, because the intermediate nuclides, particularly Rn-222, are volatile. Products of the 1980-1986 eruptions of Mount St. Helens have been analysed for (Pb-210/Ra-226). Both excesses and deficits of Pb-210 are encountered suggesting rapid gas transfer. The time scale of diffuse, non-eruptive gas escape prior to 1980 as documented by Pb-210 deficits is on the order of a decade using the model developed by Gauthier and Condomines (Earth Planet. Sci. Lett. 172 (1999) 111-126) for a non-renewed magma chamber and efficient Rn removal. The time required to build-up Pb-210 excess is much shorter (months) as can be observed from steady increases of (Pb-210/Ra-226) with time during 1980-1982. The formation of Pb-210 excess requires both rapid gas transport through the magma and periodic blocking of gas escape routes. Superposed on this time trend is the natural variability of (Pb-210/Ra-226) in a single eruption caused by tapping magma from various depths. The two time scales of gas transport, to create both Pb-210 deficits and Pb-210 excesses, cannot be reconciled in a single event. Rather Pb-210 deficits are associated with pre-eruptive diffuse degassing, while Pb-210 excesses document the more vigorous degassing associated with eruption and recharge of the system. (c) 2006 Elsevier B.V. All rights reserved.

Pb-210-Ra-226 and Ra-228-Th-232 systematics in young arc lavas: implications for magma degassing and ascent rates

New data show that island arc rocks have (Pb-210/Ra-226)(o) ratios which range from as low as 0.24 up to 2.88. In contrast, (Ra-22S/Th-232) appears always within error of I suggesting that the large Ra-226-excesses observed in arc rocks were generated more than 30 years ago. This places a maximum estimate on melt ascent velocities of around 4000 m/year and provides further confidence that the Ra-226 excesses reflect deep (source) processes rather than shallow level alteration or seawater contamination. Conversely, partial melting must have occurred more than 30 years prior to eruption. The Pb-210 deficits are most readily explained by protracted magma degassing. Using published numerical models, the data suggest that degassing occurred continuously for periods up to several decades just prior to eruption but no link with eruption periodicity was found. Longer periods are required if degassing is discontinuous, less than 100% efficient or if magma is recharged or stored after degassing. The long durations suggest much of this degassing occurs at depth with implications for the formation of hydrothermal and copper-porphyry systems. A suite of lavas erupted in 1985-1986 from Sangeang Api volcano in the Sunda arc are characterised by deficits of Pb-210 relative to Ra-226 from which 6-8 years of continuous Rn-222 degassing would be inferred from recent numerical models. These data also form a linear (Pb-210)/Pb-(Ra-226)/Pb array which might be interpreted as a 71-year isochron. However, the array passes through the origin suggesting displacement downwards from the equiline in response to degassing and so the slope of the array is inferred not to have any age significance. Simple modelling shows that the range of (Ra-226)/Pb ratios requires thousands of years to develop consistent with differentiation occurring in response to cooling at the base of the crust. Thus, degassing post-dated, and was not responsible for magma differentiation. The formation, migration and extraction of gas bubbles must be extremely efficient in mafic magma whereas the higher viscosity of more siliceous magmas retards the process and can lead to Pb-210 excesses. A possible negative correlation between (Pb-210/Ra-226)(o) and SO2 emission rate requires further testing but may have implications for future eruptions. (C) 2004 Elsevier B.V. All rights reserved.

Modelling water adsorption on Au(210) surfaces: II. Monte Carlo simulations

Canonical Monte Carlo simulations for the Au(210)/H(2)O interface, using a force field recently proposed by us, are reported. The results exhibit the main features normally observed in simulations of water molecules in contact with different noble metal surfaces. The calculations also assess the influence of the surface topography on the structural aspects of the adsorbed water and on the distribution of the water molecules in the direction normal to the metal surface plane. The adsorption process is preferential at sites in the first layer of the metal. The analysis of the density profiles and dipole moment distributions points to two predominant orientations. Most of the molecules are adsorbed with the molecular plane parallel to surface, while others adsorb with one of the O-H bonds parallel to the surface and the other bond pointing towards the bulk liquid phase. There is also evidence of hydrogen bond formation between the first and second solvent layers at the interface. (c) 2007 Elsevier B.V. All rights reserved.

Methodology for identifying parameters for the TRNSYS model Type 210 -wood pellet stoves and boilers

This report describes a method how to perform measurements on boilers and stoves and how to identify parameters from the measurements for the boiler/stove-model TRNSYS Type 210. The model can be used for detailed annual system simulations using TRNSYS. Experience from measurements on three different pellet stoves and four boilers were used to develop this methodology. Recommendations for the set up of measurements are given and the re-quired combustion theory for the data evaluation and data preparation are given. The data evalua-tion showed that the uncertainties are quite large for the measured flue gas flow rate and for boilers and stoves with high fraction of energy going to the water jacket also the calculated heat rate to the room may have large uncertainties. A methodology for the parameter identification process and identified parameters for two different stoves and three boilers are given. Finally the identified models are compared with measured data showing that the model generally agreed well with meas-ured data during both stationary and dynamic conditions.

Estabelecimento da composição volátil do nutriente FNI 210 usado pela Ceratitis capitata (Wiedemann, 1824) e dos extratos de diferentes espécies de plantas avaliação do potencial atrativo e repelente das plantas: avaliação do potencial atrativo e repelente das plantas

A mosca da fruta é uma das principais pragas agrícolas. Neste trabalho determinou-se a composição volátil do nutriente FNI 210 (proteína alimentar) e dos extratos de cinco plantas: Cedronella canariensis, Eucalyptus globulus, Laurus novocanariensis, Myrtus communis e Ruta chalepensis e avaliou-se o seu potencial atrativo e repelente em moscas adultas num olfatómetro em Y. A composição volátil do nutriente e dos extratos foi semelhante à encontrada por outros autores e apresentou compostos atrativos para a mosca da fruta. Nos bioensaios com o olfatómetro as moscas foram atraídas à proteína mas a percentagem média de respostas variou de acordo com o sexo, estado sexual, idade e número de indivíduos por grupo sendo mais alta aos 8 dias em grupos de 5. No geral, as fêmeas virgens responderam mais do que as não virgens e mais do que os machos virgens. O número de insetos que se dirigiram à proteína foi superior na primeira repetição nos primeiros 10 e 20 minutos. Contudo, em todos os bioensaios houve um número elevado de indivíduos não responderam. Nos bioensaios das plantas a resposta do mesmo grupo de 5 indivíduos com 8 dias foi testada três vezes no olfatómetro pela ordem seguinte: sem amostra, com proteína e com extrato de planta. Nos três casos as respostas dos adultos variaram de acordo com o sexo e estado sexual. As percentagens médias de respostas aos extratos foram superiores às obtidas nos ensaios sem amostra e menores que à proteína, á exceção do extrato de L. novocanariensis que apresentou um potencial atrativo superior ao da proteína nos machos virgens. Nos testes com o extrato, as respostas ao braço com amostra foram superiores ao braço sem amostra, à exceção das respostas das fêmeas não virgens ao extrato de R. chalepensis, o que sugere ser esta a única planta com potencial repelente.