Inelastic lifetimes of hot electrons in real metals

We report a first-principles description of inelastic lifetimes of excited electrons in real Cu and Al, which we compute, within the GW approximation of many-body theory, from the knowledge of the self-energy of the excited quasiparticle. Our full band-structure calculations indicate that actual lifetimes are the result of a delicate balance between localization, density of states, screening, and Fermi-surface topology. A major contribution from $d$-electrons participating in the screening of electron-electron interactions yields lifetimes of excited electrons in copper that are larger than those of electrons in a free-electron gas with the electron density equal to that of valence ($4s^1$) electrons. In aluminum, a simple metal with no $d$-bands, splitting of the band structure over the Fermi level results in electron lifetimes that are smaller than those of electrons in a free-electron gas.Comment: 4 papes, 2 figures, to appear in Phys. Rev. Let

“ENFERMEDADES DE TRANSMISIÓN SEXUAL EN ADOLESCENTES TRATADAS EN EL IMIEM DURANTE EL 2012”

El presente trabajo pretende identificar la frecuencia de las enfermedades de transmisión sexual y los factores socioculturales que favorecen la presencia de estas, entre las adolescentes que asistieron a la consulta externa en el IMIEM durante el 2012. Se realizó un estudio retrospectivo transversal descriptivo

Modelling and simulation of the effect loading on structures using and adaptive blending of discrete and finite element methods

We present a new computational model for predicting the effect of blast loading on structures. The model is based in the adaptive coupling of the finite element method (FEM) and the discrete element method (DEM) for the accurate reproduction of multifracturing and failure of structures under blast loading. In the paper we briefly describe the basis of the coupled DEM/FEM technology and demonstrate its efficiency in its application to the study of the effect of blast loading on a masonry wall, a masonry tunnel and a double curvature dam

Assessing water footprint at river basin level: a case study for the Heihe River Basin in Northwest China

Increasing water scarcity places considerable importance on the quantification of water footprint (WF) at different levels. Despite progress made previously, there are still very few WF studies focusing on specific river basins, especially for those in arid and semi-arid regions. The aim of this study is to quantify WF within the Heihe River Basin (HRB), a basin located in the arid and semi-arid northwest of China. The findings show that the WF was 1768 million m3 yr−1 in the HRB over 2004–2006. Agricultural production was the largest water consumer, accounting for 96% of the WF (92% for crop production and 4% for livestock production). The remaining 4% was for the industrial and domestic sectors. The "blue" (surface- and groundwater) component of WF was 811 million m3 yr−1. This indicates a blue water proportion of 46%, which is much higher than the world average and China's average, which is mainly due to the aridness of the HRB and a high dependence on irrigation for crop production. However, even in such a river basin, blue WF was still smaller than "green" (soil water) WF, indicating the importance of green water. We find that blue WF exceeded blue water availability during eight months per year and also on an annual basis. This indicates that WF of human activities was achieved at a cost of violating environmental flows of natural freshwater ecosystems, and such a WF pattern is not sustainable. Considering the large WF of crop production, optimizing the crop planting pattern is often a key to achieving more sustainable water use in arid and semi-arid region

Transit Stations: Sub-centers in Rotterdam Zuid

The City of Innovations Project ‘Walk-IN Stations’ is organized around speculating and projecting on future scenarios for the South of Rotterdam. Students are invited to reflect on the importance of transport networks within and extending from the city. In considering the way these networks have shaped the city through weaving the urbanities of the city center(s) and suburban areas and how they will further shape the future urban territories, this elective positions itself as a negotiation between architecture, network infrastructure, public realm, policy & governance and the territory. Stations are architectural objects which connect an area to the city’s territorial plane and have the potential to generate new urban dynamics. In the compact city the station no longer is simply the space to access mobility networks, in this informed by their dry pragmatism, but becomes an urban place of sociality and encounter - an extended public space beyond mobility itself. Furthermore, the Dutch Ministry of Infrastructure and Water Management has developed a vision on the future of Public Transport (towards 2040)1 based on new mobilities and Door-to-Door solutions. The vision was followed by the “Handelingsperspectief”, intended as an instrument to jointly map the current and future needs of PT nodes and their surroundings2. The stations of the future become hubs3, where you can transfer from one mode of transport to another. Hubs are also destinations in themselves, places to meet up, to work, to exercise, to eat. How are new mobility solutions integrated in the current system and take shape at public transport nodes, in the context of low car inner-cities (Autoluw) like in Rotterdam? Which relationships and cross-fertilizations can be significant for the design of the future urban stations in Rotterdam? How should these stations be developed in order to act as public places for collective action? How could one create an optimal mobility chain by decreasing transition friction, increasing quality of the space at station locations? This elective will attempt to answer those questions through research-by-design process, conducted by the students and tutors of Complex Projects in close collaboration with the City of Rotterdam, and enjoys the contribution of the University of Gustave Eiffel, Delta Metropool Association, De Zwarte Hond and PosadMaxwan experts on station developments. The elective course City of Innovations is scheduled in Q3, between MSc1 design studio and MSc2 research and design studio. It attracts students from different tracks, from architecture and landscape architecture to urban planning, urbanism and management. City of Innovations guides research-by-design projects focusing on mobility and public space challenges. Teachers and students work together exploring the increasingly complex world that demands increasingly complex projects, in design and also in the way of designing. The studio is organized with the method of charrette (period of intense design activity and short-term design project, usually developed in teams), focusing on 3 stations with different characters in Rotterdam Zuid. Research is done per station, in groups of 12 students; followed by a “stakeholder workshop”, students conclude the research result into spatial criteria and quality requirements. Departing from different priorities, the students split into smaller groups to develop different approaches for a more sustainable and inclusive station developed within the implementation of the new mobility method

Non-trace full-F gyro-fluid interchange impurity advection

A full-F isothermal gyro-fluid model and code (which is based on the full distribution function F compared to only small fluctuations) is extended to handle self-consistent coupling of multiple quasi-neutral ion species via the polarisation equation in the long wavelength approximation. The numerical model is used to determine two-dimensional interchange driven ‘blob’ transport in a plasma with intrinsic impurity content for a range of impurity parameters. With the same model, the self-consistent advective interaction of a main plasma species blob with a non-trace impurity cloud is studied. For homogeneous impurity distributions an increased effective mass reduces blob transport, whereas it is found that localised impurity clouds can lead either to acceleration or slowing down of blob propagation depending on the alignment of the impurity density gradient during the acceleration phase of the main ion species blob