Global carbon dioxide emissions from inland waters

Carbon dioxide (CO2) transfer from inland waters to the atmosphere, known as CO2 evasion, is a component of the global carbon cycle. Global estimates of CO2 evasion have been hampered, however, by the lack of a framework for estimating the inland water surface area and gas transfer velocity and by the absence of a global CO2 database. Here we report regional variations in global inland water surface area, dissolved CO2 and gas transfer velocity. We obtain global CO2 evasion rates of 1.8petagrams of carbon (Pg C) per year from streams and rivers and 0.32Pg Cyr-1 from lakes and reservoirs, where the upper and lower limits are respectively the 5th and 95th confidence interval percentiles. The resulting global evasion rate of 2.1 Pg Cyr-1 is higher than previous estimates owing to a larger stream and river evasion rate. Our analysis predicts global hotspots in stream and river evasion, with about 70 per cent of the flux occurring over just 20 per cent of the land surface. The source of inland water CO2 is still not known with certainty and new studies are needed to research the mechanisms controlling CO2 evasion globally. © 2013 Macmillan Publishers Limited. All rights reserved.

Vibration-rotation pattern in acetylene. II. Introduction of Coriolis coupling in the global model and analysis of emission spectra of hot acetylene around 3 microns

This paper was selected by the editors of the Journal of Chemical Physics as one of the few of the many notable JCP articles published in 2009 that present ground-breaking research

Vibration-rotation pattern in acetylene: Introduction of Coriolis coupling in the global model and analysis of emission spectra of hot acetylene around 3 µm

info:eu-repo/semantics/nonPublished

Radiación global estimada en Cerrillos (Salta) y Parque Provincial Caviahue Copahue (Neuquén)

p.257-266

Un método para estimar la radiación global con la amplitud térmica y la precipitación diarias

p.51-56

El cambio climático global

p.275-289

El uso de múltiples representaciones y la interpretación global

El presente trabajo plantea la posibilidad de impulsar la Interpretación Global, en diversas representaciones para desarrollar tratamientos que permitan fomentar la exploración de sus contenidos. La experiencia se llevó a cabo con alumnos que cursaban la asignatura de álgebra del nivel medio superior, cuyo objetivo fue identificar las conjeturas y procesos cognitivos que el alumno desarrolla cuando se ha tenido la vivencia de explorar tratamientos cualitativos y cuantitativos en múltiples representaciones. Los resultados muestran la identificación de patrones cuando se plantean situaciones familiares en el alumno, así como el anclaje del contexto para algunos estudiantes y la descontextualización para otros.

Tránsito entre representaciones en matemáticas ¿pensamiento global o local?

Este trabajo pretende dar a conocer el avance, que hasta el momento se ha logrado, en la línea de investigación: “Visualización y pensamiento global en Matemáticas”, la cual persigue, a partir de la Teoría de Representaciones Semióticas de Duval, la caracterización del estilo de pensamiento global y local, de estudiantes de nivel medio superior y superior y de sus profesores. En particular reporto los resultados preliminares encontrados hasta el momento con estudiantes de primeros semestres de licenciatura al abordar un problema de precálculo, contrastado con desempeños en ajedrez para interpretar aspectos semejantes en cuanto a la forma local o global de pensar un problema viendo sus registros que lleven a resultados que pudieran servir en la mejora de la enseñanza de algunos temas de matemáticas.

Evaluation of distortions in laser welded shipbuilding parts using local-global finite element approach

In recognition of the differences of scale between the welding pool and the heat affected zone along the welding line on one hand, and the overall size of the components being welded on the other, a local-global finite element approach was developed for the evaluation of distortions in laser welded shipbuilding parts. The approach involves the tandem use of a 'local' and a 'global' step. The local step involves a three-dimensional finite element model for the simulation of the laser welding process using the Sysweld finite element code, which takes into account thermal, metallurgical, and mechanical aspects. The simulation of the laser welding process was performed using a non-linear heat transfer analysis, based on a keyhole formation model, and a coupled transient thermomechanical analysis, which takes into account metallurgical transformations using the temperature dependent material properties and the continuous cooling transformation diagram. The size and shape of the keyhole used in the local finite element analysis was evaluated using a keyhole formation model and the Physica finite volume code. The global step involves the transfer of residual plastic strains and the stiffness of the weld obtained from the local model to the global analysis, which then provides the predicted distortions for the whole part. This newly developed methodology was applied to the evaluation of global distortions due to laser welding of stiffeners on a shipbuilding part. The approach has been proved reliable in comparison with experiments and of practical industrial use in terms of computing time and storage.

Global research collaboration: the UKIERI India-UK initiative – lessons from practice for sustainable international partnerships

As knowledge development is claimed to underpin the development of globalisation, interest in research collaboration and its internationalisation has become more widespread. This paper looks at the motivations behind, and development of, higher educational collaborations with a focus on research collaboration, and also compares some of the key issues surrounding academic collaborations. It employs current thinking on strategic alliances and in particular on social network and social capital theories to judge how collaborations can best be encouraged and managed. The paper uses the specific case of India-UK relationship as an example and looks at the context and motivation for collaboration in these two countries. It presents the UK India Education and Research Initiative (UKIERI) and reviews how this initiative deals with the issues discussed by current writers in relation to collaboration, as well as drawing lessons from the initiative for research collaboration more widely.