O Projeto Gavião e a Embrapa Semi-Árido.

bitstream/CPATSA/29047/1/OPB1920.pdfDisponível em: . Acesso em: 9 out. 2003

On the relation between Euclidean and Lorentzian 2D quantum gravity

Starting from 2D Euclidean quantum gravity, we show that one recovers 2D Lorentzian quantum gravity by removing all baby universes. Using a peeling procedure to decompose the discrete, triangulated geometries along a one-dimensional path, we explicitly associate with each Euclidean space-time a (generalized) Lorentzian space-time. This motivates a map between the parameter spaces of the two theories, under which their propagators get identified. In two dimensions, Lorentzian quantum gravity can therefore be viewed as a ``renormalized'' version of Euclidean quantum gravity.Comment: 12 pages, 2 figure

Synthesis of novel room temperature chiral ionic liquids. application as reaction media for the heck arylation of aza-endocyclic acrylates.

New achiral and chiral RTILs were prepared using novel and/or optimized synthetic routes. These new series of imidazolinium, imidazolium, pyridinium and nicotine-derived ionic liquids were fully characterized including differential scanning calorimetry (DSC) analysis. The performance of these achiral and chiral room temperature ionic liquids (RTILs) was demonstrated by means of the Heck arylation of endocyclic acrylates employing arenediazonium salts and aryl iodides. The Heck arylations performed in the presence of these ionic entities, either as a solvent or as an additive, were effective leading to complete conversion of the substrate and good to excellent yield of the Heck adduct. In spite of the good performances, no asymmetric induction was observed in any of the cases studied. Two new diastereoisomeric NHC-palladium complexes were prepared in good yields from a chiral imidazolium salt and their structure characterized by X-ray diffraction. Overall, the Heck arylations employing arenediazonium tetrafluoroborates in RTILs were more effective than the traditional protocols employing aryl iodides in terms of reactivity and yields

As cabras leiteiras de Sobradinho.

bitstream/item/124066/1/Rebert.pd

Avaliação dos impactos ambientais do sistema de produção integrada de uva de mesa na região do Submédio São Francisco.

O objetivo deste estudo foi analisar os impactos ambientais do sistema de produção integrada de uva na região do Submédio São Francisco, que é o principal pólo de exportação desta fruta no país

Análise dos custos de produção e da rentabilidade do sistema típico de produção de banana orgânica, na região do Vale do Submédio São Francisco.

Edição dos Resumos do 7 Congresso Brasileiro de Agroecologia, Fortaleza, dez. 2011