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31.
Keith C. Heidorn 《Journal of the Air & Waste Management Association (1995)》2013,63(8):803-806
In order to make the information in the Federal Register more easily accessible, a summary has been prepared of Federal standards of performance for new stationary sources of air pollution. The standards of performance promulgated by the Environmental Protection Agency in the period from December 1971 through June 1979 are presented in tabular form. 相似文献
32.
Lance S. Evans George R. Hendrey Keith H. Thompson 《Journal of the Air & Waste Management Association (1995)》2013,63(11):1107-1116
Published results of four field experiments testing effects of acidic precipitation in field-grown soybeans have led to contradictory conclusions. This paper examines the experimental procedures and protocols of the four experiments which could have contributed to differences in both the reported crop yields and the interpretations or conclusions drawn from the experiments. The most important difference among the experiments is in their statistical designs. Two of the field layouts used only one plot per treatment, providing replication only for plants, rows or sectors within plots, but not among plots. By using real data from a highly replicated experiment it is shown that with such deficient statistical designs treatment effects cannot be separated from other microenvironmental variables peculiar to a specific plot location. The other two experiments were highly replicated. They were designed to detect differences of approximately 10% among treatment means. Type 1 error, a, was predetermined, and replication was sufficient to keep type 2 error low. This design was made possible because a preliminary experiment was available to estimate the expected components of variance. Despite differences in the procedures and protocols among the four experiments, it is primarily the quality of the experimental design which has determined their validity and relative utility for crop loss assessment. 相似文献
33.
Cheryl L. Dahlin Connie A. Williamson W. Keith Collins David C. Dahlin 《Environmental Forensics》2013,14(2):191-201
The applicability of sequential extraction as a means to determine species of heavy-metals was examined by a study on soil samples from two Superfund sites: the National Lead Company site in Pedricktown, NJ, and the Roebling Steel, Inc., site in Florence, NJ. Data from a standard sequential extraction procedure were compared to those from a comprehensive study that combined optical- and scanning-electron microscopy, X-ray diffraction, and chemical analyses. The study shows that larger particles of contaminants, encapsulated contaminants, and/or man-made materials such as slags, coke, metals, and plastics are subject to incasement, non-selectivity, and redistribution in the sequential extraction process. The results indicate that standard sequential extraction procedures that were developed for characterizing species of contaminants in river sediments may be unsuitable for stand-alone determinative evaluations of contaminant species in industrial-site materials. However, if employed as part of a comprehensive, site-specific characterization study, sequential extraction could be a very useful tool. 相似文献
34.
William A. McClenny S. Mark Schmidt Keith G. Kronmiller 《Journal of the Air & Waste Management Association (1995)》2013,63(1):64-69
ABSTRACT Dalton's law of partial pressures and the hypothesis that water vapor equilibrium in a canister is identical to that established above liquid water are used to predict the variation of the percent relative humidity (%RH) of air released from canisters used in ambient air sampling, typically 6-L canisters pressurized with 18 L of air. When (and if) the water vapor partial pressure in a canister exceeds its saturation vapor pressure, water vapor condensation begins and the condensation rate equals the sampling rate of water vapor into the canister. Under constant temperature conditions, the air subsequently released from the canister is less humid than the original sample, following the relationship %RH = 100% (6 L/Vs) for Vs> Vr, where Vs is the residual air volume (referenced to atmospheric pressure), and Vr is shown to depend on the %RH of the ambient air sample. Vr is the residual air volume at which water is completely removed (except for adsorbed water vapor) from the canister wall. For Vs < Vr, the predicted %RH is constant and equal to its value at Vr. Experimental values agree reasonably well with predictions at both high (90%) and low (34%) RH. However, experimental values are often slightly displaced (usually towards lower values of %RH) for mid-range %RH (61%) and variations in %RH near Vr change from canister to canister. 相似文献
35.
Keith C. Knapp Ariel Dinar Phyllis Nash 《Journal of the American Water Resources Association》1990,26(2):289-298
ABSTRACT: Agricultural drainage water is a major source of environmental pollution in many areas. This paper reviews the literature on the economics of nonpoint-source pollution and applies it to the regulation of agricultural drainage water. Four types of regulatory policies are considered. The empirical analysis is carried out for cotton production in the San Joaquin Valley of California. Variable inputs are the quantity of water applied and the type of irrigation system. All four policies can achieve economic efficiency under the conditions assumed here, but the policies differ in terms of the distributional impacts and administrative requirements. 相似文献
36.
Randall J. Schaetzl L. Keith Hendrie Scott W. Kirsch 《Journal of the American Water Resources Association》1989,25(5):1023-1030
ABSTRACT: Soil water was monitored by neutron scattering in six soils, three each within two drainage catenas in east-central Illinois, over a 15-month time span. The prairie soils have formed in: (1) 76–152 cm of silt loam, eolian sediments (bess) over glacial till (Catlin-Flanagan-Drummer catena), and (2) bess greater than 152 cm in thickness (Tama-Ipava-Sable catena). We characterized the water content of these soils over the total time span and for wet and dry climatic subsets, as an aid to potential irrigation decisions. Soils of the thin bess, C-F-D catena dried out to lower water contents and had greater soil water variability than did the thick bess soils. Under wet conditions, soil water contents in the two catenas were quite similar. Alleviation of surface and subsurface drying via irrigation would thus be more advantageous to yields on the C-F-D soils than on the T-I-S soils. 相似文献
37.
In Hawaii, trace concentrations of pesticides used in the production of pineapple were found in the groundwater supplies of
Mililani Town in the Pearl Harbor Basin on the island of Oahu. Groundwater serves as the major source of drinking water and
residents pay for wellhead treatment of the contaminated water, via their monthly water bill. The agricultural chemical users
within the Pearl Harbor Basin do not include these wellhead treatment costs in their production costs. The agricultural industry
benefits from using pesticides but does not pay the entire societal cost of using these chemicals. In this study we evaluate
the specific financial cost of wellhead treatment, and not the economic value of groundwater. While wellhead treatment costs
could conceivably be shared by several parties, this study focuses on the financial impact of the pineapple industry alone.
This study factors annual wellhead treatment costs into annual pineapple production costs to measure the effect on annual
financial return from pineapple production. Wellhead treatment costs are calculated from the existing granulated activated
carbon (GAC) water treatment facility for Millilani Wells I and II. Pineapple production costs are estimated from previous
cost of production studies. The inclusion of wellhead treatment costs produces different production-cost results, depending
on the scale of analysis. At the local scale, the Mililani wellhead treatment costs can be factored into the production costs
of the pineapple fields, which were probably responsible for contamination of the Mililani Wells, without causing a deficit
in economic return. At the larger regional scale, however, the return from all of the pineapple grown in the Pearl Harbor
Basin can not sustain the cost of wellhead treatmentfor the entire water supply of the basin. Recommendations point to the
prevention of groundwater contamination as more cost-effective measure than wellhead treatment. 相似文献
38.
The declining cocoa economy and the Atlantic Forest of Southern Bahia,Brazil: Conservation attitudes of cocoa planters 总被引:6,自引:0,他引:6
Summary The causes of the degradation of Brazilian Atlantic Forest in the south-eastern cocoa region of the State of Bahia are investigated by means of a survey on cocoa planter's forest conservation attitudes. Large land-owners were found to be responsible for most of the forest clearing that occurred in the past: cocoa prices compensated investment in the expansion of the area planted to cocoa on planters' forested land-holdings. Large land-owners were also responsible for most of the recent forest clearing, which occurred simply to sell trees in order to earn income while cocoa prices were depressed. Large land-owners are nonetheless more interested than small land-owners in conserving some of their forest. Policies encouraging private forest conservation, and the development of forest-conserving agricultural alternatives for the landless poor are recommended.Dr Keith Alger teaches at the Universidade Estadual de Santa Cruz in Southern Bahia, a community college in Brazil's cocoa producing region. He is Vice-President of Fundação Pau Brasil, a non-profit association of local researchers and environmentalists whose objective is to encourage the conservation of biodiversity in regional, economic and social development. He does volunteer work for Projeto Mico-Leão Baiano (The Bahian Lion Tamarin Project), an environmental education project coordinated by maria Cristina Alves and sponsored by the Wildlife Preservation Trust International. Dr Alger's current research on land-use tendencies in a wildlife park buffer zone is supported by Conservation International and the World Wildlife fund. Marcellus Caldas took his MS in agricultural economics at the Universidade Federal de Viçosa in Minas Gerais, and teaches at the Universidade Federal da Bahia in Cruz das Almas, Bahia, Brazil. 相似文献
39.
John E. Keith Rangesan Narayanan 《Journal of the American Water Resources Association》1988,24(6):1247-1256
ABSTRACF: Examination of a series of studies of the economically efficient water allocations in the Upper Colorado River, Yellowstone River, and Great Basins indicate that water is not a serious general physical constraint on the development of energy resources, so long as public institutions do not hinder the exchange of water rights in markets. Energy development will cause limited impacts on other water-using sectors, principally agriculture. There appears to be little reason to develop large-scale water storage facilities, even during periods of reduced water production. Water storage developments appear to be necessary only when institutional constraints severely restrict water rights markets and transfers. 相似文献
40.