Microwave irradiation has been used to prepare Al, Fe-pillared clays from a natural Tunisian smectite from the El Hicha deposit (province of Gabes). Chemical analysis, XRD spectra and surface properties evidenced the success of pillaring process. The obtained solids present higher surface area and pore volume than conventionally prepared Al-Fe pillared clays. The main advantages of the microwave methodology are the considerable reduction of the synthesis time and the consumption of water. The microwave-derived Al-Fe pillared clays have been tested for catalytic wet air oxidation (CWAO) of phenol in a stirred tank at 160°C and 20 bar of pure oxygen pressure. These materials are efficient for CWAO of phenol and are highly stable despite the severe operating conditions (acidic media, high pressure, high temperature). The catalyst deactivation was also significantly hindered when compared to conventionally prepared clays. Al-Fe pillared clays prepared by microwave methodology are promising as catalysts for CWAO industrial water treatment.
Measures of fish abundance, assemblage composition and length were compared when sampled by baited remote underwater stereo-video
(stereo BRUV) and diver-operated stereo-video transects (stereo DOV) at the Houtman Abrolhos Islands and Ningaloo Reef. Species
richness counts were 40% higher on stereo BRUV than stereo DOV. Stereo BRUVs also recorded a greater number of large-bodied
targeted species in higher abundance than stereo DOV (e.g. Lethrinus nebulosus, Plectropomus leopardus) at the Houtman Abrolhos and at Ningaloo Reef. Many non-targeted species were also recorded in greater abundances on stereo
BRUV than stereo DOV (e.g. Coris auricularis, Gymnothorax spp). Stereo DOV transects recorded a greater abundance of some small-bodied Pomacentridae, Labridae and Scaridae species
than did stereo BRUV, particularly at Ningaloo Reef. This study demonstrates that choice of sampling technique for surveys
of reef fish can lead to very different biological interpretations of fish assemblage structure. 相似文献
Most woody plants contain a diverse array of plant secondary metabolites (PSMs) that deter vertebrate herbivores. However,
mammalian folivores have evolved a complex of physiological and behavioural strategies to counter these compounds, leading
to the development of an “evolutionary arms race”. Marsupial folivores are ideal models to investigate the role of PSMs in
the interaction between the external foraging environment and the digestive physiology of mammalian herbivores, as we have
a very strong understanding of the diversity and modes of action of PSMs in Eucalyptus, as well as the mechanisms by which animals overcome the effects of these compounds. Studies of marsupial folivores have
benefited from the facts that: these herbivores subsist on relatively poor quality diets; they include feeding types from
specialist species such as the koala, to generalists; and life history factors such as maternal investment in reproduction
can be measured more easily than in eutherians. Here, we describe patterns of spatial variation in the types and distributions
of plant secondary metabolites in Australian forests and discuss how this variation influences foraging behaviour, habitat
selection and life history strategies in arboreal, folivorous marsupials. We also provide a summary of our understanding of
the mechanisms by which marsupials detect and regulate their intake of toxic compounds. While our examples are drawn largely
from studies of the interaction between marsupials and Eucalyptus, this knowledge is applicable to advancing our understanding of interactions in plant–mammal systems more broadly. We also
identify and discuss key areas that should be the focus of future research. 相似文献
This research used distal motor latency (DML) and vibration thresholds (VT) to evaluate 84 hand activity and wrist deviation combinations to determine the best association with carpal tunnel syndrome (CTS). Female volunteers, 2 healthy and 2 CTS diagnosed, were age matched and operated a keyboard for 4 hrs a day. Room temperature was 28°C(±2). Beginning DML and VT were taken with a relaxed neutral posture hand. The wrist was deviated in a randomly selected combination, and determinations were taken at 5-min intervals. The trial ended at 20 min or when discomfort was felt. The CTS conditions were discriminated by pain four times, DML once, and VT 14 times. Vibrometry was the most consistent CTS discriminator. The best VT results for wrist positions were obtained with wrist extension and extended extension, whereas the unclenched, clenched, and loaded power grip activities proved to be the most consistent hand activities. 相似文献
Many regulating ecosystem services exhibit non-excludability and non-rivalry characteristics akin to public goods. This makes it unlikely that such regulating ecosystem services will attract a price in the marketplace. Policymakers, therefore, find difficulties in determining a correct economic valuation for regulating ecosystem services, with potentially severe consequences for aligning policy for ecosystem service provision with public preferences for service delivery. This research used a choice modelling approach to estimate public preferences for delivery of two regulating ecosystem services; reductions in the flood risk to the British city of York (implemented by filling in drainage ditches in peat moorland further up the catchment), and a reduction in CO2 emissions (implemented by planting Poplar trees for biomass either locally in the study area or elsewhere in the UK). The choice experiment presented respondents with options providing different levels of CO2 reduction, implemented locally or nationally, and different levels of flood risk reduction, at a range of different prices, with a tax as the payment vehicle. Subsequent analysis with latent class (LC) models showed considerable heterogeneity of preference among respondents, particularly with regard to the location of tree planting for CO2 reduction. One LC segment showed a significant preference for achieving a high level CO2 reduction through national, as opposed to local tree planting, potentially indicating the existence of NIMBYism. The same LC segment displayed a preference for moderate reductions in the flood risk to York, even though this would deliver no personal benefit for a substantial proportion of the segment. This could, therefore, indicate altruistic behaviour towards geographically proximate beneficiaries. 相似文献