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61.
Smart characterization approaches apply the latest high‐resolution site characterization methods to find the contaminant mass flux, by integrating relative permeability mapping, classical hydrostratigraphy interpretation, and high‐density groundwater and saturated soil sampling. The key factor that makes Smart characterization different is the application of quantitative saturated soil sampling in less permeable slow advection and storage zones to diagnose plume maturity and understand its implications for remedy selection and performance. Because direct sensing tools like the membrane interface probe are capable of providing screening‐level assessments for hydrocarbons and chlorinated solvents in storage zones, but not 1,4‐dioxane, the recommended Smart approach involves application of specialized high‐capacity mobile laboratories or rapid turn‐around using fixed commercial labs. In addition to the benefit of rapidly characterizing sites, Smart characterization facilitates a flux‐based conceptual site model, which allows stakeholders to focus remedies on the mobile portion of the contaminant mass or, in effect, the mass that matters. Through systematic planning and implementation, predesign characterization can be completed to optimize source and plume remedy strategies, balancing investment in Smart characterization with reductions in total life‐cycle costs to ensure that an appropriate return on investigation is obtained.  © 2016 Wiley Periodicals, Inc.  相似文献   
62.
The role of nitrogen (N) in acidification of soil and water has become relatively more important as the deposition of sulphur has decreased. Starting in 1991, we have conducted a whole-catchment experiment with N addition at Gårdsjön, Sweden, to investigate the risk of N saturation. We have added 41 kg N ha−1 yr−1 as NH4NO3 to the ambient 9 kg N ha−1 yr−1 in fortnightly doses by means of sprinkling system. The fraction of input N lost to runoff has increased from 0% to 10%. Increased concentrations of NO3 in runoff partially offset the decreasing concentrations of SO4 and slowed ecosystem recovery from acid deposition. From 1990-2002, about 5% of the total N input went to runoff, 44% to biomass, and the remaining 51% to soil. The soil N pool increased by 5%. N deposition enhanced carbon (C) sequestration at a mean C/N ratio of 42-59 g g−1.  相似文献   
63.
The growing interest in bio-polymers as a packaging material, particularly from companies looking to reduce their environmental footprint, has resulted in wider adoption. Traditionally the selection and specification of packaging materials was based on aesthetic, technical and financial factors, for which established metrics exist. However with bio-polymers, where the primary rationale for their use is environmental, alternative metrics are required. Furthermore, there is a significant strategic element to the decision process that requires a broader range of horizontal and vertical inputs, both within the business and the wider supply chain. It is therefore essential that a holistic approach is taken to the bio-polymer based packaging design process to ensure that the final packaging meets the original strategic intent and overall requirements of the business. Current eco-packaging design tools are generally limited to professional users, such as designers or packaging engineers, and generally provide tactical rather than strategic support. This disconnect, between the need for inclusivity and greater strategic support in holistic design, and the exclusivity and largely tactical support of current eco-design support tools, indicates a clear need for a new decision support tool for sustainable pack design using bio-polymers. This paper proposes a framework for an eco-design decision support tool for bio-polymer based packaging that has been developed using a predominantly qualitative research approach based on reviews, interviews and industrial packaging design experience and is an extension of previously published work. This research investigates further how existing eco-design methods, such as the ‘Balanced Score Card’, can be applied within the tool and how the shortcomings associated with incorporating social and environmental aspects can be partly resolved, through a simplified set of metrics tailored specifically for bio-polymer packaging decisions. The results of this research is a framework for the development of a three tier eco-design tool for bio-polymer packaging that provides decision support at the three critical stages of the design process: strategic fit, Feasibility assessment and concept/pack development.  相似文献   
64.
Mozambique, like many African countries, is already highly susceptible to climate variability and extreme weather events. Climate change threatens to heighten this vulnerability. In order to evaluate potential impacts and adaptation options for Mozambique, we develop an integrated modeling framework that translates atmospheric changes from general circulation model projections into biophysical outcomes via detailed hydrologic, crop, hydropower and infrastructure models. These sector models simulate a historical baseline and four extreme climate change scenarios. Sector results are then passed down to a dynamic computable general equilibrium model, which is used to estimate economy-wide impacts on national welfare, as well as the total cost of damages caused by climate change. Potential damages without changes in policy are significant; our discounted estimates range from US$ 2.3 to US $7.4 billion during 2003?C2050. Our analysis identifies improved road design and agricultural sector investments as key ??no-regret?? adaptation measures, alongside intensified efforts to develop a more flexible and resilient society. Our findings also support the need for cooperative river basin management and the regional coordination of adaptation strategies.  相似文献   
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Compost application to turfgrass soils may increase dissolved organic C (DOC) levels which affects nutrient dynamics in soil. The objectives of this study were to investigate the influence of compost source and application rate on soil organic C (SOC), DOC, NO(3), and available P during 29 months after a one-time application to St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] turf. Compost sources had variable composition, yet resulted in few differences in SOC, DOC, and NO(3) after applied to soil. Available NO(3) rapidly decreased after compost application and was unaffected by compost source and application rate. Available P increased after compost application and exhibited cyclical seasonal patterns related to DOC. Compost application decreased soil pH relative to unamended soil, but pH increased during the course of the study due to irrigation with sodic water. Increasing the compost application rate increased SOC by 3 months, and levels remained fairly stable to 29 months. In contrast, DOC continued to increase from 3 to 29 months after application, suggesting that compost mineralization and growth of St. Augustinegrass contributed to seasonal dynamics. Dissolved organic C was 75%, 78%, and 101% greater 29 months after application of 0, 80, and 160 Mg compostha(-1), respectively, than before application. Impacts of composts on soil properties indicated that most significant effects occurred within a few months of application. Seasonal variability of SOC, DOC, and available P was likely related to St. Augustinegrass growth stages as well as precipitation, as declines occurred after precipitation events.  相似文献   
68.
Summary. Schistocerca gregaria, the desert locust, has been shown to regulate its dietary intake with respect to specific macronutrients in synthetic foods. This study examined the nutrients in the leaves of two starch mutants of Arabidopsis thaliana, and then compared the feeding behaviour of locusts on the two starch mutants. The high-starch mutant had c. 25 times more starch than the no-starch mutant. Newly molted 5th stadium locusts were preconditioned for 3 days on one of the mutants, and then observed for 90 min while exposed to the same or the alternative mutant. Locusts pretreated with the no-starch mutant fed longer during the first meal on high-starch mutants, spent more time feeding, and had the smaller latency to begin a meal when compared to the locusts pretreated on the high-starch mutant. The results of the study are interpreted in light of an integrative model of nutrient balancing. Received 16 November 1999; accepted 23 December 1999  相似文献   
69.
Multiple criteria evaluation (MCE) is often used with GIS to identify suitable sites for multi-purpose development such as ecotourism. Typically, expert or stakeholder consultation is used to identify weights reflecting the relative importance of map layers representing different criteria. The objective of this study was to evaluate a new consultative approach to GIS-based MCE, using ecotourism development in Kurdistan, Iraq, as a case study. In an initial and follow-up consultation, stakeholders were asked not only to assess the relative importance of different map layers for ecotourism development, but also to identify specific sites suitable for ecotourism. Seventy-eight ecotourism destinations nominated by participants had significantly higher MCE scores than a set of 58 locations chosen without reference to stakeholders (t-test = 21.16; p < 0.001). The approach thus provides a straightforward means of assessing the consistency of stakeholder input into MCE and could be adapted for use in other site suitability assessments.  相似文献   
70.
Abstract

Odorous gases associated with livestock operations are complex mixtures of hundreds if not thousands of compounds. Research is needed to know how best to sample and analyze these compounds. The main objective of this research was to compare recoveries of a standard gas mixture of 11 odorous compounds from the Carboxen/PDMS 75–μm solid–phase microextraction fibers, polyvinyl fluo–ride (PVF; Tedlar), fluorinated ethylene propylene copolymer (FEP; Teflon), foil, and polyethylene terephthalate (PET; Melinex) air sampling bags, sorbent 2,b–diphenylene–oxide polymer resin (Tenax TA) tubes, and standard 6–L Stabilizer sampling canisters after sample storage for 0.5, 24, and 120 (for sorbent tubes only) hrs at room temperature. The standard gas mixture consisted of 7 volatile fatty acids (VFAs) from acetic to hexanoic, and 4 semivolatile organic compounds including p–cresol, indole, 4–ethylphenol, and 2'–aminoacetophenone with concentrations ranging from 5.1 ppb for indole to 1270 ppb for acetic acid. On average, SPME had the highest mean recovery for all 11 gases of 106.2%, and 98.3% for 0.5– and 24–hr sample storage time, respectively. This was followed by the Tenax TA sorbent tubes (94.8% and 88.3%) for 24 and 120 hr, respectively; PET bags (71.7% and 47.2%), FEP bags (75.4% and 39.4%), commercial Tedlar bags (67.6% and 22.7%), in–house–made Tedlar bags (47.3% and 37.4%), foil bags (16.4% and 4.3%), and canisters (4.2% and 0.5%), for 0.5 and 24 hr, respectively. VFAs had higher recoveries than semivolatile organic compounds for all of the bags and canisters. New FEP bags and new foil bags had the lowest and the highest amounts of chemical impurities, respectively. New commercial Tedlar bags had measurable concentrations of N,N–dimethyl acetamide and phenol. Foil bags had measurable concentrations of acetic, propionic, butyric, valeric, and hexanoic acids.  相似文献   
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