7,615 research outputs found
Four dimensional R^4 superinvariants through gauge completion
We fully compute the N=1 supersymmetrization of the fourth power of the Weyl
tensor in d=4 x-space with the auxiliary fields. In a previous paper, we showed
that their elimination requires an infinite number of terms; we explicitely
compute those terms to order \kappa^4 (three loop). We also write, in
superspace notation, all the possible N=1 actions, in four dimensions, that
contain pure R^4 terms (with coupling constants). We explicitely write these
actions in terms of the \theta components of the chiral density \epsilon and
the supergravity superfields R, G_m, W_{ABC}. Using the method of gauge
completion, we compute the necessary \theta components which allow us to write
these actions in x-space. We discuss under which circumstances can these extra
R^4 correction terms be reabsorbed in the pure supergravity action, and their
relevance to the quantum supergravity/string theory effective actions.Comment: 20 pages, no figures. Sec. 3 clarified; typos correcte
Political economy, political entrepreneurship and biofuels regulation in the US
Title from PDF of title page (University of Missouri--Columbia, viewed on March 31, 2011).The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Thesis advisor: Dr. Michael Sykuta.M.S. University of Missouri--Columbia 2010.This paper draws on theories of regulation from the political entrepreneurship and political economy fields to explore the dynamics of the US biofuels market. The conducted case study addresses questions regarding the life cycle and development of this industry and attempts to identify the actors, the roles they play(ed) and the driving forces shaping it. Archer Daniels Midland (ADM) is identified as having played a significant role through exercising immense political entrepreneurship, which laid ground for the present market. As the market matured, profit incentives stimulated the emergence of competing actors, who in their combined actions, shaped regulation of the biofuels industry. Although interest group action may not be the only factor explaining the creation and persistence of the US biofuels market, I conclude that it is a significant factor.Includes bibliographical references
The evolution of the European framework for coastal management, linked to the new environmental challenges. The Portuguese case
The sharing of space by various human activities leading to social conflicts and threats to ecosystems,
alongside increased awareness of the threats to coastal zones has created the need to legislate on coastal planning and integrated management by developing international guidelines. A new management challenge has emerged due to climate change that had not previously been considered in legislation or policies. Therefore, the European tools and frameworks applied in Portugal, their implementation and effectiveness will be analysed. Extensive bibliographic data was analysed including EU directives and policies, and Portuguese governmental documents from national to a municipal level. We found that all the European Union guidelines and frameworks are being implemented in the Portuguese Governmental planning and are very well substantiated, whereas the base of all land management instruments (IGT), have a questionable implementation, mainly due to the number of entities involved and the long implementation process.MACOMA SGA ERASMUS MUNDUS 2015-1626/001-001-EMJDinfo:eu-repo/semantics/publishedVersio
Análisis de la conducta matemática de estudiantes desde modelos económicos a la teoría de las situaciones didácticas
En este póster se presenta un estudio cuyo objetivo es interpretar modelos económicos (Morton, 1971; Elster, 1989; Carmona, 1997; Bueno, 2004), concretamente los que implican “elección”, “toma de decisiones” y “teoría de juegos”, para analizar la conducta matemática de los estudiantes cuando resuelven problemas en el aula y establecer la relación entre dichos modelos
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