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441.
Sikora LJ 《Waste management (New York, N.Y.)》2004,24(2):139-142
A by-product of the construction aggregate industry is fines or dust that contain trace elements such as zinc and copper and significant amounts of iron, aluminum, silica and potassium. Beneficial uses for these materials have been proposed such as replenishing depleted soils and amendment in mixtures of organic byproducts prior to composting. To evaluate the beneficial uses in composting, outdoor bin studies were conducted using a beef cattle manure, straw and wood chip mixture amended with and without basaltic mineral fines. Temperature differences in composting mixtures of equal volumes, equal moisture and relatively equal material content are considered an indication of differing biological activities [Haug, Compost Engineering Principles and Practice. Ann Arbor Science, Ann Arbor, MI. (1980)]. Temperatures were lower in the mineral fine-treated manure mixture initially. After turning the piles at six weeks, temperatures tended to be higher in the mineral fine amended mixture. Overall, temperatures were not significantly different suggesting that mineral fines amendment does not significantly increase temperature and activity in composting mixtures. 相似文献
442.
Acid-neutralizing capacity (ANC) and pH were measured weekly from October 1991 through September 2001 in three streams in the western Adirondack Mountain region of New York to identify trends in stream chemistry that might be related to changes in acidic deposition. A decreasing trend in atmospheric deposition of SO4/2- was observed within the region over the 10-yr period, although most of the decrease occurred between 1991 and 1995. Both ANC and pH were inversely related to flow in all streams; therefore, a trend analysis was conducted on (i) the measured values of ANC and pH and (ii) the residuals of the concentration-discharge relations. In Buck Creek, ANC increased significantly (p < 0.05) over the 10 yr, but the residuals of ANC showed no trend (p > 0.10). In Bald Mountain Brook, ANC and residuals of ANC increased significantly (p < 0.01), although the trend was diatonic-a distinct decrease from 1991 to 1996 was followed by a distinct increase from 1996 to 2001. In Fly Pond outlet, ANC and residuals of ANC increased over the study period (p < 0.01), although the trend of the residuals resulted largely from an abrupt increase in 1997. In general, the trends observed in the three streams are similar to results presented for Adirondack lakes in a previous study, and are consistent with the declining trend in atmospheric deposition for this region, although the observed trends in ANC and pH in streams could not be directly attributed to the trends in acidic deposition. 相似文献
443.
Biobased Epoxy/Layered Silicate Nanocomposites: Thermophysical Properties and Fracture Behavior Evaluation 总被引:1,自引:0,他引:1
Hiroaki?Miyagawa Manjusri?Misra Lawrence?T.?Drzal Amar?K.?MohantyEmail author 《Journal of Polymers and the Environment》2005,13(2):87-96
The biobased epoxy containing epoxidized linseed oil (ELO) and its clay nanocomposites were processed with an anhydride curing agent. The certain amount of diglycidyl ether of bisphenol F (DGEBF) was replaced by ELO. The selection of the DGEBF, ELO, an anhydride curing agent, and organo-montmorillonite clay resulted in an excellent combination, to provide new biobased epoxy/clay nanocomposites showing high elastic modulus, high glass transition temperature, and high fracture toughness with larger amount of ELO. Izod impact strength was almost constant while changing the amount of ELO. This is a promising result for future applications in different engineering industries. 相似文献
444.
Summary The suckling behaviour of 130 freeranging elephant calves aged between birth and 4.5 years old was examined in Amboseli National Park, Kenya. Analyses of frequencies of suckling and durations of suckling bouts showed that males attempted to suckle more often, were more successful at their attempts, and as a result were estimated to have a higher milk intake than did female calves. Mothers were equally tolerant of their sons' and daughters' demands to suckle at young ages, but were less tolerant of their older sons' demands. The growth rates of males based on hind footprint length were faster than those of females from birth onwards. During drought years with low food availability, male calf survivorship in the first year was lower than that of female calves. During wet years, there was little difference between sexes in survivorship. It appeared that during dry years mothers were unable to sustain milk production at a level that met the metabolic requirements of their sons, and as result male calves were more likely to die. Females with a surviving son tended to have a longer interbirth interval than did females with a surviving daughter. We suggest that greater early maternal investment in male calves occurs because, in the highly-competitive polygynous mating system of elephants, size in adult male elephants is an important factor in mating success. 相似文献
445.
This paper deals with the problem of isolating random errors from rainfall measurements in watersheds of relatively small size. The residual variance is shown to be a practical measure for assessing the error term. KEY WORDS: random errors; rainfall; watershed 相似文献
446.
D. P. Lawrence 《Journal of Environmental Planning and Management》1996,39(2):165-188
The siting of waste facilities is a popular subject but one constrained by a tendency to advocate a single solution regardless of context. This effort to address the siting of waste facilities from a broader perspective describes three major siting approaches and a range of site selection methods. The application of siting approaches and methods in 10 waste siting examples are described, general conclusions are advanced and suggestions for further initiatives are offered. 相似文献
447.
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449.
Adrian R. Lawrence P. John Chilton Richard J. Barron William M. Thomas 《Journal of contaminant hydrology》1990,6(4)
Conventional methods of sampling groundwater in Chalk aquifers sample the mobile water in the fissures only and not the non-mobile water held in the microporous matrix. However, the microporous matrix can play an important role in modifying groundwater quality by attenuating contaminant migration through diffusion exchange and, in the long term, by acting as a reservoir for contaminant retention.A method for extracting and analysing chalk pore waters for chlorinated solvents has been developed. Chalk pore water-depth profiles at the site of a spillage of tetrachloroethene demonstrated that the immiscible phase of the solvent had migrated to depths of 50 m, producing solvent concentrations in the matrix pore waters of up to 40,000 μg L−1.In addition, the pore water-depth profile indicated that the immiscible phase had ponded upon a less permeable horizon within the Chalk aquifer at shallow depths. 相似文献
450.
A unique collaborative, sociological study undertaken during 1995-7, explored the social construction of drought as a disaster, looking at farm families in two Australian states: Queensland (beef producers) and New South Wales (sheep/wheat producers). A decision was made to interview the women and men separately to test our hypothesis that there would be gender issues in any analysis of a disaster, but particularly one which has had so much long-term impact on individuals, families and communities, such as drought. Interviews were conducted with over 100 individuals male and female. We conclude that drought as a disaster is a gendered experience. The paper draws on the narratives of some women involved in the study to identify 'themes of difference' which confirm the necessity to maintain gender as a variable in all studies of the social impacts of disaster. 相似文献