3 resultados para Grazing cycles
em Universidad de Alicante
Resumo:
This paper considers the influence of business cycles and economic crises on tourism destinations competitiveness. This competitiveness is measured by its share in world tourism. Analysing a period of forty years, the differential permanent or temporary effects that economic crises has on competitiveness of mature and emerging destinations are observed. Furthermore, it identifies the economic transmission mechanisms operating within this context, analysing them using the framework of the most relevant explanatory models of tourism destination competitiveness. The preliminary results obtained suggest that the effects of these shocks on competitiveness are not neutral. In mature destinations the negative effects are more persistent in highly intensive crises. In emerging destinations with a growing natural trend on tourism demand, the effects of the economic crises are softer and limited, reinforcing the process of convergence between destinations. This effect works through two basic transmission mechanisms: the reduction of internal and external tourism demand and the decrease on investment.
Resumo:
Even though it has been proved that a fully thermally coupled distillation (TCD) system minimizes the energy used by a sequence of columns, it is well-known that vapor/liquid transfers between different sections produce an unavoidable excess of vapor (liquid) in some of them, increasing both the investment and operating costs. It is proposed here to take advantage of this situation by extracting the extra vapor/liquid and subjecting it to a direct/reverse vapor compression cycle. This new arrangement restores the optimal operating conditions of some of the affected sections with energy savings of around 20–30% compared with conventional TCD columns. Various examples, including the direct and reverse vapor recompression cycles, are presented. Furthermore, in each example, all possible modes of distillation (direct, indirect and Petlyuk distillation) with and without vapor recompression cycles (VRC) are compared to ensure that this approach delivers the best results.
Resumo:
The combined effects of drought stress and grazing pressure on shaping plant–plant interactions are still poorly understood, while this combination is common in arid ecosystems. In this study we assessed the relative effect of grazing pressure and slope aspect (drought stress) on vegetation cover and soil functioning in semi-arid Mediterranean grassland–shrublands in southeastern Spain. Moreover, we linked these two stress factors to plant co-occurrence patterns at species-pair and community levels, by performing C-score analyses. Vegetation cover and soil functioning decreased with higher grazing pressure and more south-facing (drier) slopes. At the community level, plants at south-facing slopes were negatively associated at no grazing but positively associated at low grazing pressure and randomly associated at high grazing pressure. At north-facing slopes, grazing did not result in a shift in the direction of the association. In contrast, analysis of pairwise species co-occurrence patterns showed that the dominant species Stipa tenacissima and Anthyllis cytisoides shifted from excluding each other to co-occurring with increasing grazing pressure at north-facing slopes. Our findings highlight that for improved understanding of plant interactions along stress gradients, interactions between species pairs and interactions at the community level should be assessed, as these may reveal contrasting results.