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161.
The flow characteristics of polypropylene filled with high percentages of wood flour (50 and 70 wt%) are investigated at a feasible processing temperature (195 °C). Rotational rheometry in oscillatory mode in conjunction with the Cox–Merz rule is ineffective at this temperature due to insufficient linear viscoelastic region (LVR) size and ease of fibres degradation. An in-line rheometer, directly attached to a single screw extruder, is used to avoid these problems: this method allows measurements in real processing conditions with no LVR issues and with reduced degradation risks. The 70 wt% displays plug flow, thus it has been impossible to obtain the flow curve but only the slip velocity as a function of shear stress. The 50 wt% could be corrected for slip using the Mooney procedure. Comparing the flow curve of this material with the ones of the 30 wt% and the unfilled polypropylene matrix, a single master-curve can be obtained and modelled with a Carreau–Yasuda equation. 相似文献
162.
Elena Gissi Jennifer McGowan Chiara Venier Davide Di Carlo Francesco Musco Stefano Menegon Peter Mackelworth Tundi Agardy Hugh Possingham 《Conservation biology》2018,32(5):1107-1117
The Adriatic and Ionian Region is an important area for both strategic maritime development and biodiversity conservation in the European Union (EU). However, given that both EU and non‐EU countries border the sea, multiple legal and regulatory frameworks operate at different scales, which can hinder the coordinated long‐term sustainable development of the region. Transboundary marine spatial planning can help overcome these challenges by building consensus on planning objectives and making the trade‐offs between biodiversity conservation and its influence on economically important sectors more explicit. We address this challenge by developing and testing 4 spatial prioritization strategies with the decision‐support tool Marxan, which meets targets for biodiversity conservation while minimizing impacts to users. We evaluated these strategies in terms of how priority areas shift under different scales of target setting (e.g., regional vs. country level). We also examined the trade‐off between cost‐efficiency and how equally solutions represent countries and maritime industries (n = 14) operating in the region with the protection‐equality metric. We found negligible differences in where priority conservation areas were located when we set targets for biodiversity at the regional versus country scale. Conversely, the prospective impacts on industries, when considered as costs to be minimized, were highly divergent across scenarios and biased the placement of protection toward industries located in isolation or where there were few other industries. We recommend underpinning future marine spatial planning efforts in the region through identification of areas of national significance, transboundary areas requiring cooperation between countries, and areas where impacts on maritime industries require careful consideration of the trade‐off between biodiversity conservation and socioeconomic objectives. 相似文献
163.
Alessandra Pugnetti Francesco Acri Luisa Alberighi Donato Barletta Mauro Bastianini Fabrizio Bernardi-Aubry 《Chemistry and Ecology》2013,29(6):399-409
Taxonomic composition, biomass, primary production and growth rates of the phytoplankton community were studied in two stations in the NW Adriatic Sea on a seasonal basis, in areas characterized by differing hydrological and trophic conditions. The main differences between the two stations were quantitative rather than qualitative, most phytoplankton species being common to both stations. The effects of differing nutrient concentrations and plume spreading were evident. Biomass and primary production rates were significantly higher in the coastal station (S1), and the phytoplankton distribution in the water column was markedly stratified in S1 and more even in the offshore station (S3). However, chlorophyll a specific production, potential growth rate and production efficiencies were very similar in both stations, even when phosphorus concentrations were limiting. A discrepancy between potential and actual growth rate was observed: as a feature common to both stations, comparisons between potential and actual growth rates revealed that little carbon produced by phytoplankton accumulated as algal biomass; therefore, very high loss rates were estimated. 相似文献
164.
Economic theory provides different perspectives on the relationship between environmental regulation and company environmental and competitive performance. A frequently analysed issue refers to the impact of environmental regulation on company performance. Using qualitative data collected within the recently completed Environmental regulation and Market forces Providing Incentives for Resource Efficiency (EMPIRE) project, we analysed the relationship between environmental regulation and company competitiveness, operating in the building and construction (B&C) sector. Empirical evidence from the correlation analysis emphasises that environmental regulation can be an important driver of competitive performance improvements in relevant segments of the European B&C sector. 相似文献
165.
Timothée R. Cook Maike Hamann Lorien Pichegru Francesco Bonadonna David Grémillet Peter G. Ryan 《Marine Biology》2012,159(2):373-387
Knowledge on how divers exploit the water column vertically in relation to water depth is crucial to our understanding of
their ecology and to their subsequent conservation. However, information is still lacking for the smaller-bodied species,
due mostly to size constraints of data-loggers. Here, we report the diving behaviour of a flying diving seabird, the Cape
Cormorant Phalacrocorax capensis, weighing 1.0–1.4 kg. Results were obtained by simultaneously deploying small, high resolution and high sampling frequency
GPS and time-depth loggers on birds breeding on islands off Western South Africa (34°S, 18°E) in 2008. In all, dive category
was assigned to all dives performed by 29 birds. Pelagic dives occurred almost as frequently as benthic dives. Pelagic dives
were shallow (mean: 5 m) and took place over seafloors 5–100 m deep. Benthic dives were deeper, occurring on seafloors mainly
10–30 m deep. Dive shape was linked to dive category in only 60% of dives, while the descent rate, ascent rate and bottom
duration/dive duration ratio of a dive best explained its dive category. This shows that only the concomitant use of tracking
and depth tags can adequately classify diving strategies in a diver like the Cape Cormorant. Diet was mainly Cape Anchovy
Engraulis encrasicolis, suggesting that birds probably displayed two contrasted strategies for capturing the same prey. Flexible foraging techniques
represent an important key to survival inside the highly productive but heterogeneous Benguela upwelling ecosystem. 相似文献
166.
167.
Environmental and Ecological Statistics - A regression model for correlated circular data is proposed by assuming that samples of angular measurements are drawn from a multivariate von Mises... 相似文献
168.
Marwan A. Hassan Michael Church Thomas E. Lisle Francesco Brardinoni Lee Benda Gordon E. Grant 《Journal of the American Water Resources Association》2005,41(4):853-876
This paper reviews sediment transport and channel morphology in small, forested streams in the Pacific Northwest region of North America to assess current knowledge of channel stability and morphology relevant to riparian management practices around small streams. Small channels are defined as ones in which morphology and hydraulics may be significantly influenced by individual clasts or wood materials in the channel. Such channels are headwater channels in close proximity to sediment sources, so they reflect a mix of hillslope and channel processes. Sediment inputs are derived directly from adjacent hillslopes and from the channel banks. Morphologically significant sediments move mainly as bed load, mainly at low intensity, and there is no standard method for measurement. The larger clastic and woody elements in the channel form persistent structures that trap significant volumes of sediment, reducing sediment transport in the short term and substantially increasing channel stability. The presence of such structures makes modeling of sediment flux in these channels — a potential substitute for measurement — difficult. Channel morphology is discussed, with some emphasis on wood related features. The problem of classifying small channels is reviewed, and it is recognized that useful classifications are purpose oriented. Reach scale and channel unit scale morphologies are categorized. A “disturbance cascade” is introduced to focus attention on sediment transfers through the slope channel system and to identify management practices that affect sediment dynamics and consequent channel morphology. Gaps in knowledge, errors, and uncertainties have been identified for future research. 相似文献
169.
The management of solid waste is changing. The traditional approach based on landfilling of mixed refuses is shifting toward
a system based on the at-source sorting of waste into specific fractions. The biological treatment of the organic fraction
is considered to be an appropriate form of disposal not only for the “traditional≓ feedstock such as food scraps and vegetable
and garden waste, but also for biodegradable packaging, when not recyclable in other ways. Any change from a complex system
to another is difficult since many factors are to be organized and optimized. Industry must develop and manufacture compostable
products, municipalities must build composting plants and organize source-separated collection, and regulatory bodies must
define widely acceptable criteria of compostability. In Europe, the European Union has assigned the last task to the CEN,
to provide common criteria and avoid hindrance to commercial exchanges. In Italy the UNI, the national standardization organization,
has produced a working document to contribute to the discussion on the European level. In this paper the UNI scheme is described.
A condensed version of this paper was presented by one of the authors (F.D.I.) at the 5th annual meeting of the BEDP Society,
held in Nashville, September 22–26, 1996, during a session covering International Standards for Biodegradation Testing. 相似文献
170.
Two typical waters from thermal springs of Montecatini Terme-used as therapeutical beverages-exhibit a small complexing capacity towards Cu2+. By differential pulse anodic stripping voltammetry the following values were found: 0.46 μmol 1-1 and 0.10 μmol 1-1, respectively for Regina and Rinfresco waters.
Owing to the presence of a small amount of complexed copper in the original samples, the complexing capacity has to be regarded as residual capacity. In bottled waters from the same springs no complexing capacity was detected. Values of formation constants for copper complexes are given. No residual complexing capacity for Cu2+ was displayed for Tamerici and Tettuccio thermal waters. 相似文献
Owing to the presence of a small amount of complexed copper in the original samples, the complexing capacity has to be regarded as residual capacity. In bottled waters from the same springs no complexing capacity was detected. Values of formation constants for copper complexes are given. No residual complexing capacity for Cu2+ was displayed for Tamerici and Tettuccio thermal waters. 相似文献