998 resultados para sustainable chemistry
Resumo:
The coadsorption of water with organic molecules under near-ambient pressure and temperature conditions opens up new reaction pathways on model catalyst surfaces that are not accessible in conventional ultrahigh-vacuum surfacescience experiments. The surface chemistry of glycine and alanine at the water-exposed Cu{110} interface was studied in situ using ambient-pressure photoemission and X-ray absorption spectroscopy techniques. At water pressures above 10-5 Torr a significant pressure-dependent decrease in the temperature for dissociative desorption was observed for both amino acids, accompanied by the appearance of a newCN intermediate, which is not observed for lower pressures. The most likely reaction mechanisms involve dehydrogenation induced by O and/or OH surface species resulting from the dissociative adsorption of water. The linear relationship between the inverse decomposition temperature and the logarithm of water pressure enables determination of the activation energy for the surface reaction, between 213 and 232 kJ/mol, and a prediction of the decomposition temperature at the solidliquid interface by extrapolating toward the equilibrium vapor pressure. Such experiments near the equilibrium vapor pressure provide important information about elementary surface processes at the solidliquid interface, which can be retrieved neither under ultrahigh vacuum conditions nor from interfaces immersed in a solution.
Resumo:
This paper explores in particular how Teikei groups, as forms of Community Supported Agriculture (CSA), operate in Japan, focussing on one particular group. The paper links the Teikei approach to debates around social capital and consumer-citizenship, arguing that pre-existing consumer/citizen institutions may usefully be engaged in developing food citizenship and CSA operations. The discussion is linked to CSA and various other alternative food networks (AFNs) that have grown up in various forms in Japan, the US, the UK and elsewhere in Europe over the past thirty years or so. CSA in similar fashion to Teikei involves bringing producers and consumers closer together in terms of reconnecting the agricultural producer and consumer to aid food traceability and quality (including organic). CSA also exhibits elements of new assemblies of agricultural governance based on enhanced consumer-citizenship where consumers, to varying degrees, have a say in what and how produce is grown and how the land is managed.
Resumo:
This paper investigates whether obtaining sustainable building certification entails a rental premium for commercial office buildings and tracks its development over time. To this aim, both a difference-in-differences and a fixed-effects model approach are applied to a large panel dataset of office buildings in the United States in the 2000–2010 period. The results indicate a significant rental premium for both ENERGY STAR and LEED certified buildings. Controlling for confounding factors, this premium is shown to have increased steadily from 2006 to 2008, followed by a moderate decline in the subsequent periods. The results also show a significant positive relationship between ENERGY STAR labeling and building occupancy rates.