2 resultados para Research reports
em Repositório Científico da Universidade de Évora - Portugal
Resumo:
This special issue reports some of the highlights of the conference Living Landscape – The European Landscape Convention in Research Perspective, organised jointly by UNISCAPE and Landscape Europe (UNISCAPE, 2010). Starting questions for this conference were: what has science contributed to the implementation of the European Landscape Convention (CoE, 2000) and what are the topics for the future of European landscape? The 10th anniversary of the Florence Convention in October 2010 was an opportunity to discuss the merits of landscape science in integrated research of a rapidly changing environment. Many interdisciplinary contributions presented referred to the Landscape Convention. The conference focused on cutting-edge research results at the crossroads of sciences and humanities, design and empiricism. Not by chance, the conference was also the occasion to launch a new ESF-COST Science-Policy Briefing on Landscape Research (Bloemers, Daniels, Fairclough, Pedroli, & Stiles, 2010 Bloemers, T., Daniels, S., Fairclough, G., Pedroli, B., & Stiles, R. (Eds.) (2010) Landscape in a changing world. Bridging Divides, integrating disciplines, serving society. Science Policy Briefing nr 41. Strasbourg and Brussels: ESF-COST. ): ‘Landscape in a Changing World – Bridging Divides, Integrating Disciplines, Serving Society’. It emphasises the importance of four interdisciplinary themes: Universal commons: securing landscape as a common good. Roots and routes: coming to terms with mobility and evolving lifestyles. Reactions and resilience: long-term landscape transformations. Road maps: landscape as baseline and context for future change. The papers in this special issue largely reflect these themes.
Resumo:
The cyclization of pseudoionone yields a mixture of alpha-ionone, beta-ionone and gamma-ionone. By careful control of reagent and reaction conditions, either the alpha- and beta- isomer can be favoured. The alpha-ionone has violet odour and is widely used in perfumery and flavours. beta-Ionone is the main precursor of Vitamin A and beta-carotene. Traditionally, strong homogeneous catalysts, like sulphuric acid and phosphoric acid have been used. These problems can be overcome by the use of solid acid catalysts. This work reports the cyclization of pseudoionone over USY zeolites, at 80ºC. USY It is observed that the initial activity increases with the Si/Al ratio of zeolite until a maximum, which is obtained with USY3. With higher Si/Al ratio, a decrease in the catalytic activity is observed. Selectivity to ionone isomers is around 42 %, at 75% of pseudoionone conversion, after 24 h of reaction. USY3 zeolite was reused four times with the same catalyst sample in the same condicions. It was observed a stabilization of the catalytic activity, after the second use.