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41.
Nowadays, the world faces unprecedented challenges in social, environmental and economical dimensions, in which the industrial design has showed an important contribution with solutions that provide positive answers regarding these problems. In particular, due to its relevance, the automotive industry confronts a moment of crises, and based on the ecodesign of products it has been transforming the challenges in opportunities. In this context, the use of natural fiber composites, produced in developing countries, have presented several social, environmental and economical advantages to design “green” automotive components. Thus, this work through LCA method demonstrates the possibility to use natural fibers through a case study design which investigates the environmental improvements related to the replacement of glass fibers for natural jute fibers, to produce a structural frontal bonnet of an off-road vehicle (Buggy). Results pointed out the advantages of applying jute fiber composites in Buggy enclosures.  相似文献   
42.
An important alternative for sustainable use of tucunaré stocks and improvement in fishermen welfare in Balbina reservoir, Central Amazon, would be to train commercial fisherman to also become tourist guides for sport fishing. In this study, we modeled fishermen response to this question, in order to evaluate the acceptance of such an idea. Thus, we surveyed 47 fishermen, who currently comprise approximately 75% of the total fishermen population. This survey was implemented during December of 2001 and January of 2002. We used a probity analysis to run two models. The first model includes the variables: family size, school level, fishing time, residence time and boat ownership. On the other hand, the second model includes the number of children under and above eight years old but not the family size. Both models are significant and the most relevant variables are: fishing time (years of participation of fisherman is in the activity) and residence time (length of residency of particular fishermen live at the village nearby the reservoir).  相似文献   
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44.
This work was aimed at finding materials that could be used as alternatives to lichens as air quality monitors since the high natural variability and the large amount of lichen collected are two drawbacks of the use of these organisms. Lichen Flavoparmelia caperata(L.) Hale was exposed in three different forms (transplant, detached from the substratum and as a biomass-ground and homogeneized) and compared to the planetree bark (Platanus hybrida Brot.), exposed as a biomass, and two organic synthetic materials (Chelex(R) 100 resin and cellulose acetate). Materials were exposed for two months in the winter, spring and summer, at three Portuguese coastal cities. The results showed that the airborne accumulations of Cu, Ni, Pb and Sr were partially dependent on the meteorological conditions but mainly dependent on the nature of the exposed material. The standard deviations of the synthetic materials or homogenized biomass were the same or greater than lichen transplants or detached. The accumulation by biological materials, of the four studied elements, was comparable to the lichen transplant accumulation. The replacement of the traditional transplants by the biomass was not considered advantageous, since their preparation is time-consuming. Therefore lichens remain the most suitable in biomonitoring studies. The exposure of detached lichen allows the accurate measurement of the exposed area/volume so it can be useful to relate atmospheric deposition rates with the lichen metal content. The synthetic materials accumulated Cu and Ni and should only be used as an alternative to traditional transplants when these are the elements of interest.  相似文献   
45.
This paper compares the dynamics, i.e. the rates of change in element concentrations of young and older lichen thallus parts, of one foliose and one fruticose lichen, during a transplant experiment to a polluted site. Both lichen parts respond to environmental changes. Here, differential accumulation suggests that differential constitution leads to differential uptake and release, and/or the overall behaviour is partly due to internal translocation and regulation mechanisms within the whole lichen. For thallus parts, internal translocation should be taken into account as one more factor affecting lichen “memory length”. Young parts of the thallus presented higher rates of change, but different lichen parts accumulate different elements to different extents. Therefore tissue selection in monitoring may depend on the element of interest, and cannot be made into a generalized approach in survey set-ups: the choice depends on the element.  相似文献   
46.
Regarding Brazilian coast, industrial and urban developments are concentrated along Central South Brazil Bight. Samples from inshore and offshore species from the concerned area were analyzed, comprising 24 cetaceans (9 species) and 32 squids (2 species). Cadmium was determined by GFAAS and our results were in agreement with certified values (DOLT-2, NRCC). Mean cadmium concentration (in microg/g, wet weight) observed in the digestive gland of sexually mature Argentine short-finned squids (Illex argentinus) was 1002.9. To our knowledge this is the highest cadmium level ever reported for a cephalopod. Concerning cetaceans, our results include one of the highest renal cadmium concentrations described for striped dolphins (71.29 microg/g, wet weight). Anthropogenic action, upwelling and cannibalism of Argentine short-finned squid on the studied area are possible reasons for such remarkable cadmium concentrations.  相似文献   
47.
Regional Environmental Change - This paper examines barriers and opportunities for climate change adaptation in an urban coastal setting where adaptation is in its infancy. It draws on a diagnostic...  相似文献   
48.
Environmental Science and Pollution Research - Herbicides are hazardous organic pollutants that contribute to the risk of environmental contamination. The aim of this work was to investigate the...  相似文献   
49.
Trail-making ants lay pheromones on the substrate to define paths between foraging areas and the nest. Combined with the chemistry of these pheromone trails and the physics of evaporation, trail-laying and trail-following behaviours provide ant colonies with the quickest routes to food. In relatively uniform environments, such as that provided in many laboratory studies of trail-making ants, the quickest route is also often the shortest route. Here, we show that carpenter ants (Camponotus rufipes), in natural conditions, are able to make use of apparent obstacles in their environment to assist in finding the fastest routes to food. These ants make extensive use of fallen branches, twigs and lianas as bridges to build their trails. These bridges make trails significantly longer than their straight line equivalents across the forest floor, but we estimate that ants spend less than half the time to reach the same point, due to increased carriage speed across the bridges. We also found that these trails, mainly composed of bridges, are maintained for months, so they can be characterized as trunk trails. We suggest that pheromone-based foraging trail networks in field conditions are likely to be structured by a range of potentially complex factors but that even then, speed remains the most important consideration.  相似文献   
50.
Many situations in practice require appropriate specification of operating characteristics under extreme conditions. Typical examples include environmental sciences where studies include extreme temperature, rainfall and river flow to name a few. In these cases, the effect of geographic and climatological inputs are likely to play a relevant role. This paper is concerned with the study of extreme data in the presence of relevant auxiliary information. The underlying model involves a mixture distribution: a generalized Pareto distribution is assumed for the exceedances beyond a high threshold and a non-parametric approach is assumed for the data below the threshold. Thus, the full likelihood including data below and above the threshold is considered in the estimation. The main novelty is the introduction of a regression structure to explain the variation of the exceedances through all tail parameters. Estimation is performed under the Bayesian paradigm and includes model choice. This allows for determination of higher quantiles under each covariate configuration and upper bounds for the data, where appropriate. Simulation results show that the models are appropriate and identifiable. The models are applied to the study of two temperature datasets: maxima in the U.S.A. and minima in Brazil, and compared to other related models.  相似文献   
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