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271.
Rebecca A. Efroymson Virginia H. Dale Keith L. Kline Allen C. McBride Jeffrey M. Bielicki Raymond L. Smith Esther S. Parish Peter E. Schweizer Denice M. Shaw 《Environmental management》2013,51(2):291-306
Indicators of the environmental sustainability of biofuel production, distribution, and use should be selected, measured, and interpreted with respect to the context in which they are used. The context of a sustainability assessment includes the purpose, the particular biofuel production and distribution system, policy conditions, stakeholder values, location, temporal influences, spatial scale, baselines, and reference scenarios. We recommend that biofuel sustainability questions be formulated with respect to the context, that appropriate indicators of environmental sustainability be developed or selected from more generic suites, and that decision makers consider context in ascribing meaning to indicators. In addition, considerations such as technical objectives, varying values and perspectives of stakeholder groups, indicator cost, and availability and reliability of data need to be understood and considered. Sustainability indicators for biofuels are most useful if adequate historical data are available, information can be collected at appropriate spatial and temporal scales, organizations are committed to use indicator information in the decision-making process, and indicators can effectively guide behavior toward more sustainable practices. 相似文献
272.
This study adopted an open-ended exploratory approach to elicit the perspectives of a selection of six Climate Challenge Fund projects. This central idea is that communities' perspective on attempted carbon reduction initiative in their areas has use in other contexts and could enable better design of such interventions in future. The main finding was that emphasising local benefits was conducive to their achieving local involvement in the project. The results of this research should be tested in other contexts. Three broad implications for the design of community carbon reduction initiatives are raised in assuming these outcomes are correct. First, the community hosting such initiatives should be perceived to hold a degree of power over the project. Second, central authorities should not be overly prohibitive about the motivations of those participating in such projects. Finally, the use of non-environmental messaging has value in shifting people to more pro-environmental behaviours. 相似文献
273.
Methyl bromide, a pre-emergent soil fumigant, is scheduled to be phased out in the US by 2005, with exceptions for critical use. Comparison of some of the physical constants related to distribution and retention for methyl bromide (MBr) to other fumigants yields a useful quantification of possible alternatives. In this study, the atmospheric and subsurface dissipation of methyl bromide as well as (Z)- and (E)-1,3-dichloropropene (1,3-D) isomers in Telone II were examined. The Henry's law constants of the three chemicals at soil temperature and their mass transfer coefficients for movement through an agricultural mulch of UV-resistant, high-density polyethylene (PE) were evaluated using field data. At the soil temperature of 16.4 degrees C, calculated Henry's law constant gave a fumigant ranking of MBr (0.21)>(Z)-1,3-D (0.041)>(E)-1,3-D (0.027). Since rapid subsurface distribution of a fumigant is highly dependent on the amount in the gas phase, the greater value for Henry's law constant implies faster distribution throughout the soil. After distribution through the soil, retention of the fumigant becomes imperative. Calculation of the fumigant's mass transfer coefficients through PE from field data gave a ranking of the three chemicals: MBr (1.08 cm/h)<(E)-1,3-D (3.25 cm/h)<(Z)-1,3-D (4.13 cm/h). With mass transfer coefficients of this magnitude, it was concluded that PE film was an inadequate barrier for retaining these fumigants in an agricultural setting. 相似文献
274.
Pedological processes such as gleization and organic matter accumulation may affect the vertical distribution of P within agricultural drainage ditch soils. The objective of this study was to assess the vertical distribution of P as a function of horizonation in ditch soils at the University of Maryland Eastern Shore Research Farm in Princess Anne, Maryland. Twenty-one profiles were sampled from 10 agricultural ditches ranging in length from 225 to 550 m. Horizon samples were analyzed for total P; water-extractable P; Mehlich-3 P; acid ammonium oxalate-extractable P, Fe, and Al (P ox, Fe ox, Al ox); pH; and organic C (n = 126). Total P ranged from 27 to 4882 mg kg(-1), P ox from 4 to 4631 mg kg(-1), Mehlich-3 P from 2 to 401 mg kg(-1), and water-extractable P from 0 to 17 mg kg(-1). Soil-forming processes that result in differences between horizons had a strong relationship with various P fractions and P sorption capacity. Fibric organic horizons at the ditch soil surface had the greatest mean P ox, Fe ox, and Al ox concentrations of any horizon class. Gleyed A horizons had a mean Fe ox concentrations 2.6 times lower than dark A horizons and were significantly lower in total P and P ox. Variation in P due to organic matter accumulation and gleization provide critical insight into short- and long-term dynamics of P in ditch soils and should be accounted for when applying ditch management practices. 相似文献
275.
276.
Annie Resse 《Waste management & research》2005,23(1):87-91
According to the new regulations on junk mail management to be adopted in France, both producers and distributors must participate in the recycling process. This case study was carried out in 2000 in four sectors in the Departement of Charente in the south west of France. This report presents the quantities of junk mail in residual waste and in separate collections. The conclusion is that the new regulations may reduce overall domestic waste production by 2-4%, with the impact on separately collected paper being some 20%. 相似文献
277.
Carl P. Maertz Jr Rodger W. Griffeth Nathanael S. Campbell David G. Allen 《组织行为杂志》2007,28(8):1059-1075
This study examines mediated effects of perceived supervisor support (PSS) and perceived organizational support (POS) on turnover cognitions, and their interactive effects on turnover behavior in a sample of 225 social services workers. In this study, we address a seeming contradiction in current findings regarding support and attachments to managers versus attachments to the organization itself. The POS literature suggests fully mediated causal paths to turnover from POS and PSS, through affective commitment. Whereas, the commitment, LMX, and turnover literatures suggest alternative causal paths that imply broader effects for POS and PSS on turnover. Contrary to earlier POS literature, findings showed that PSS had independent effects on turnover cognitions not mediated through POS. Model tests also indicated that POS had significant effects on turnover mediated through normative commitment, as well as affective organizational commitment. Moreover, a new significant interactive relationship was discovered such that low PSS strengthened the negative relationship between POS and turnover, while high PSS weakened it. Implications for research and practice are discussed. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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