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Christopher?H.?SchillingEmail author Piotr?Tomasik David?S.?Karpovich Bruce?Hart Jagdeep?Garcha Paul?T.?Boettcher 《Journal of Polymers and the Environment》2005,13(3):203-211
Corn distillers’ dry grain, corncob powder, hardwood powder, and sugar beet pulp were separately anionized by oxidation with sodium hypochlorite in aqueous solution. Solid reaction products instantly precipitated upon admixing each of the above-oxidized materials with soy protein isolate. Infrared spectra and differential scanning calorimetry supported the hypothesis that soy protein isolate complexed with all of the above-oxidized polysaccharides. Reaction products with either oxidized corn distillers’ dry grain or oxidized sugar beet pulp provided hard, brittle pellets with tensile strengths as high as 9.5 MPa, suggesting that these materials could be viable as biodegradable plastics. 相似文献
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D. F. Soule M. Oguri F. Shahrokhi N. L. Jones L. A. Sharver M. S. Connor R. W. Howarth R. W. Yeung G. C. Christodoulou J. J. Connor B. R. Pearce D. A. Rice R. D. Anderson J. W. Anderson N. V. Alisov E. B. Valev A. V. Doncheva V. N. Kalutskov Paul E. Lydolph Philip P. Micklin N. T. Kuznetsov 《Environmental management》1977,1(6):549-555
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Paul D. Robillard Michael F. Walter David J. Allee 《Journal of the American Water Resources Association》1979,15(5):1430-1443
ABSTRACT: The suggested methodology matches flooding risks to development classes. The matching process is accomplished on a mapping grid basis. Flooding risks include stage and velocity measures. Development classes are based on size and building material parameters for residential, commercial, industrial, and public structures. A computer program counts structures requiring predetermined nonstructural measures given the flooding variables, development classes, and desired effectiveness levels in question. A case study is presented to demonstrate data collection techniques, output, and the use of output in developing nonstructural mixes. 相似文献
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Although it is understood that the composition of riparian trees can affect stream function through leaf litter fall, the potential effects of genetic variation within species are less understood. Using a naturally hybridizing cottonwood system, we examined the hypothesis that genetic differences among two parental species (Populus fremontii and P. angustifolia) and two groups of their hybrids (F1 and backcrosses to P. angustifolia) would affect litter decomposition rates and the composition of the aquatic invertebrate community that colonizes leaves. Three major findings emerged: (1) parental and hybrid types differ in litter quality, (2) decomposition differs between two groups, a fast group (P. fremontii and F1 hybrid), and a slow group (P. angustifolia and backcross hybrids), and (3) aquatic invertebrate communities colonizing P. fremontii litter differed significantly in composition from all other cross types, even though P. fremontii and the F1 hybrid decomposed at similar rates. These findings are in agreement with terrestrial arthropod studies in the same cottonwood system. However, the effects are less pronounced aquatically than those observed in the adjacent terrestrial community, which supports a genetic diffusion hypothesis. Importantly, these findings argue that genetic interactions link terrestrial and aquatic communities and may have significant evolutionary and conservation implications. 相似文献
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Modeling the beta diversity of coral reefs 总被引:1,自引:0,他引:1
Quantifying the beta diversity (species replacement along spatiotemporal gradients) of ecosystems is important for understanding and conserving patterns of biodiversity. However, virtually all studies of beta diversity focus on one-dimensional transects orientated along a specific environmental gradient that is defined a priori. By ignoring a second spatial dimension and the associated changes in species composition and environmental gradients, this approach may provide limited insight into the full pattern of beta diversity. Here, we use remotely sensed imagery to quantify beta diversity continuously, in two dimensions, and at multiple scales across an entire tropical marine seascape. We then show that beta diversity can be modeled (0.852 > or = r2 > or = 0.590) at spatial scales between 0.5 and 5.0 km2, using the environmental variables of mean and variance of depth and wave exposure. Beta diversity, quantified within a "window" of a given size, is positively correlated to the range of environmental conditions within that window. For example, beta diversity increases with increasing variance of depth. By analyzing such relationships across seascapes, this study provides a framework for a range of disparate coral reef literature including studies of zonation, diversity, and disturbance. Using supporting evidence from soft-bottom communities, we hypothesize that depth will be an important variable for modeling beta diversity in a range of marine systems. We discuss the implications of our results for the design of marine reserves. 相似文献