574 research outputs found
Els darrers jaciments arqueològics descoberts a Premià . Una aportació a l'inventari arqueològic de Premià de Dalt i Premià de Mar (El Maresme)
El Clientelismo de partido en España ante la opinión pública : el medio rural, la administración y las empresas
Risk Management in Megaprojects
AbstractDespite its high relevance to the success of megaprojects, risk management remains one of the least developed research issues. Risk management is a process composed of several phases. This paper is focused on the first of these phases: risk identification. Our purpose is to establish the state of the art in risk management in megaprojects, systematize the risks studied in the literature, as well as to identify potential areas of further research. To this end, a systematic review is carried out. Academic journals and conference papers published from 2000 onwards in main databases (WoK, Scopus and ABI) have been examined. A qualitative analysis has been performed by using ATLAS.ti together with a checklist. To the best of the authors’ knowledge, no previous systematic revision of papers on risk management in megaprojects has ever been carried out, although certain authors have emphasized its importance.The contribution of this research includes: a bibliometric analysis of the papers that focus on risk management in megaprojects; a systematization and classification of the risks; tw†o matrices comprised of the proposed risk categorization, first in relation to the sector studied, and second related with the different stakeholders; and an identification of gaps in the research in risk management in megaprojects.The systematization of the risks helps managers towards their identification within the megaproject, and to follow the subsequent steps in the risk management process. Moreover, the matrix developed on the transfer of risks can enable managers to analyse who would be the best partner to support each risk. Furthermore, from an academic point of view, potential areas for future lines of research are presented
Reversible Tuning of Ca Nanoparticles Embedded in a Superionic CaF2 Matrix
ABSTRACT: Controlling the size and shape of metallic colloids is crucial for a number of nanotechnological applications ranging from medical diagnosis to electronics. Yet, achieving tunability of morphological changes at the nanoscale is technically difficult and the structural modifications made on nanoparticles generally are irreversible. Here, we present a simple non-chemical method for controlling the size of metallic colloids in a reversible manner. Our strategy consists on applying hydrostatic pressure on a Ca cationic sublattice embedded in the irradiated matrix of CaF2 containing a large concentration of defects. Application of our method to CaF2 along with in situ optical absorption of the Ca plasmon shows that the radii of the Ca nanoparticles can be reduced with an almost constant rate of −1.2 nm/GPa up to a threshold pressure of ∼ 9.4 GPa. We demonstrate recovery of the original nanoparticles upon decompression of the irradiated matrix. The mechanisms for reversible nanocolloid-size variation are analyzed with first-principles simulations. We show that a pressure-driven increase in the binding energy between fluorine centers is responsible for the observed nanoparticle shrinkage. We argue that the same method can be used to generate other metallic colloids (Li, K, Sr, and Cs) with tailored dimensions by simply selecting an appropriate matrix
Estudi sobre el Movimento dos Trabalhadores Rurais Sem Terra : implementació de la reforma agrà ria per transformar la societat
Premi UAB de la Fundació Autònoma Solidà ria (FAS) als millors Treballs de Fi de Grau sobre desenvolupament sostenible i justÃcia global. 2n Edició, curs 2017/2018Grau Ciencia PolÃtica amb menció Relacions InternacionalsAquest estudi té com objectiu donar a conèixer la lluita del Movimento dos Trabalhadores Rurais Sem Terra, que a través de pressionar el govern per implementar una reforma agrà ria a Brasil, pretén provocar una transformació social tant a escala nacional com global. Perquè això esdevingui una realitat, proposen democratitzar el latifundi, el capital i el coneixement, i aixà es pot comprovar visitant els seus assentaments, on han pogut implementar la reforma agrà ria que proposen
Thallium under extreme compression
We present a combined theoretical and experimental study of the high-pressure
behavior of thallium. X-ray diffraction experiments have been carried out at
room temperature up to 125 GPa using diamond-anvil cells, nearly doubling the
pressure range of previous experiments. We have confirmed the hcp-fcc
transition at 3.5 GPa and determined that the fcc structure remains stable up
to the highest pressure attained in the experiments. In addition, HP-HT
experiments have been performed up to 8 GPa and 700 K by using a combination of
x-ray diffraction and a resistively heated diamond-anvil cell. Information on
the phase boundaries is obtained, as well as crystallographic information on
the HT bcc phase. The equation of state for different phases is reported. Ab
initio calculations have also been carried out considering several potential
high-pressure structures. They are consistent with the experimental results and
predict that, among the structures considered in the calculations, the fcc
structure of thallium is stable up to 4.3 TPa. Calculations also predict the
post-fcc phase to have a close-packed orthorhombic structure above 4.3 TPa.Comment: 29 pages, 14 figure
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