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141.
Phosphorus (P) runoff from fields fertilized with swine (Sus scrofa domesticus) manure may contribute to eutrophication. The objective of this study was to evaluate the effect of aluminum sulfate (alum) and aluminum chloride applications to swine manure on P runoff from small plots cropped to tall fescue (Festuca arundinacea Shreb.). There were six treatments in this study: (i) unfertilized control plots, (ii) untreated manure, (iii) manure with alum at 215 mg Al L(-1), (iv) manure with aluminum chloride at 215 mg Al L(-1), (v) manure with alum at 430 mg Al L(-1), and (vi) manure with aluminum chloride at 430 mg Al L(-1). Manure application rates were equivalent to approximately 125 kg N ha(-1). Alum and aluminum chloride additions lowered soluble reactive phosphorus (SRP) levels from about 130 mg P L(-1) to approximately 30 mg P L(-1) at low rates. At high rates, SRP levels in swine manure were around 1 mg P L(-1). Soluble reactive P concentrations in runoff were 5.50, 3.66, 3.00, 0.87, 0.87, and 0.55 mg P L(-1), for normal manure, low alum, low aluminum chloride, high alum, high aluminum chloride, and unfertilized control plots, respectively. Hence, high alum and aluminum chloride reduced SRP concentrations in runoff by 84% and were not statistically different from SRP concentrations in runoff from unfertilized control plots. These data indicate that treating swine manure with alum or aluminum chloride could result in significant reductions in nonpoint-source P runoff.  相似文献   
142.
Daniel Maxwell 《Disasters》2007,31(S1):S25-S39
Food aid is a key component of a humanitarian response but its use in other programming contexts is subject to numerous criticisms. Even in humanitarian emergencies food aid is often late, unreliable and out of proportion to other elements of the response. Three major factors will shape the future of food aid. First, mechanisms of food aid governance are being reviewed and may undergo major changes—particularly the Food Aid Convention now that hopes have diminished for an Agreement on Agriculture at the World Trade Organisation. The second significant factor is donor agency trends. Overall levels of food aid have dropped fairly steadily in recent decades and there are several discernible trends in resource allocation, procurement and the use of food aid. The third factor is an emerging body of best practice that will define acceptable standards of food aid programming in the future.  相似文献   
143.
The flammability of vapors above aqueous solutions of ethanol and acetonitrile was studied experimentally in a 20-L combustion apparatus. No liquid was present in the apparatus, but the vapor concentrations were adjusted to correspond to the vapor in equilibrium with a specified aqueous solution. The experimental results for these two systems show that
• As water is added to the vapor, the lower boundary of the flammability zone decreases. For ethanol, the lower flammability limits (LFL) decreases from 3.7% for pure vapor to 3.2% with saturated water vapor. For acetonitrile, the decrease is from 4.2% to 3.8%. Thus, to a good approximation, the water vapor can be treated as an inert, enabling the data to be displayed on a single flammability triangle diagram. This provides a very simplified method for estimating the flammable behavior for aqueous solutions.

• The upper boundary of the flammability zone is unchanged with the addition of water.

• The limiting oxygen concentration (LOC) is essentially constant for all concentrations of aqueous solutions. The LOC for the pure solvent may be used as a universal LOC for all solvent concentrations.

• The vapor mixture above the aqueous solution is not flammable below a certain liquid mol fraction of flammable. The flammable concentration at which this occurs can be called the maximum safe solvent concentration (MSSC). A method is presented to determine the MSSC from experimental flammability data.

• The oxygen concentration defining the flammable boundary for the vapor decreases rapidly from the MSSC and then increases as the liquid solvent concentration increases.

The calculated adiabatic flame temperature (CAFT) method qualitatively predicts the same behavior as the experimental data.  相似文献   

144.
145.
ABSTRACT: The use of continuous hydrologic-hydraulic-water quality models is inhibited by their large computer run costs relative to cost incurred with discrete event models. The fixed recurrence interval transfer (FRIT) technique is a means of achieving substantial reductions in computer costs associated with continuous models while retaining their technical advantages. The FRIT technique is applicable where it is reasonable to assume that the recurrence interval of the response of a watershed to a causative meteorologic event is the same for both “before” and “after” conditions. Example applications of the FRIT technique to the hydrologic-hydraulic modeling of floodwater storage, land use changes, and channel modifications are presented to demonstrate the procedure, to suggest the expected accuracy, and to illustrate how computer run costs might be reduced by 99% or more. The FRIT technique is intended for preliminary assessment of the impact of alternative land use conditions and structural water control measures.  相似文献   
146.
Paired water samples were simultaneously activated from two different vertical positions within the approach section of a flow-control structure to determine the effect of sample intake position on nonpoint runoff parameter concentrations and subsequent event loads. Suspended solids (SS), total phosphorus (TP) and organic plus exchangeable nitrogen [(Or+Ex)-N] were consistently higher throughout each runoff event when sampled from the floor of the approach section as opposed to those samples taken at midstage. Dissolved molybdate reactive phosphorus (DMRP) and ammonium (NH4-N) concentrations did not appear to be significantly affected by the vertical difference in intake position. However, the nitrate plus nitrite nitrogen [(NO3+NO2)-N] concentrations were much higher when sampled from the midstage position.Although the concentration differences between the two methods were not appreciable, when evaluated in terms of event loads, discrepancies were evident for all parameters. Midstage sampling produced event loads for SS, TP, (Or + Ex)–N, DMRP, NH4-N, and (NO3+NO2)-N that were 44,39,35,80,71, and 181%, respectively, of floor sampling loads. Differences in loads between the two methods are attributed to the midstage position, sampling less of the bed load. The correct position will depend on the objective; however, such differences should be recognized during the design phase of the monitoring program.This work was supported by the Soil Science Department, College of Agriculture and Life Sciences, University of Wisconsin-Madison, and by the U.S. Environmental Protection Agency, Region V., Chicago, Illinois (Grant No. G005139-01).  相似文献   
147.
Some of the literature pertinent to the interactions of birds of flight and man made obstacles, such as transmission lines is reviewed here. Some birds use these towers, poles, and buildings for nesting and perches. They also collide with them. Original observations presented here suggest that the environmental impacts of these types of obstacles on birds, and vice-versa, seem not due to the inability of the birds to perceive the obstacles, but rather that the birds are apparently distracted from a safe flight pattern by their own species, or by others. Editor's Note: Although this paper is quite specialized in comparison with many other articles published in Environmental Management, I feel it is a very useful overview of the problems and the literature related to bird collisions with manmade obstacles. It is hoped that the information presented by the Willards will be helpful to other workers who are perhaps engaged in preparing environmental impact statements concerning structures that could invite bird collisions.  相似文献   
148.
Planning considerations to be evaluated early in the design of water quality monitoring programs are reviewed. These criteria emphasize the importance of isolating the study area, parameter section, and type of measurements required to ensure meaningful results. A demonstration automatic water quality monitoring program is described. Details with respect to type of equipment, coordination of component parts, sampling program, and analysis of specific parameters are reviewed. General costs of implementation and maintenance of such programs are presented.  相似文献   
149.
To the USSR resource depletion is not a threat to be taken seriously on a world-wide basis but rather a manifestation of capitalism. Shortages caused by the system will aggravate the contradictions inherent in capitalism and hasten its downfall. The socialist world avoids resource crises by planning its economies. The author examines here the ideological basis of views held on the resources question in the USSR and the role resources planning will play in the eventual triumph of socialism.  相似文献   
150.
ABSTRACT: The applicability of the U.S Environmental Protection Agency's (USEPA) water temperature criteria in evaluating the impact of a thermal discharge from the P. H. Glatfelter Paper Company, Spring Grove, Pennsylvania, is analyzed. A review of the literature relative to 11 temperature Criteria was conducted for six fish species designated by the USEPA as “representative important species” (RIS) of the West Branch Codorus Creek, Susquehanna River drainage. The species were: Notemigonus crysolcucas (golden shiner), Notropis analostanus (satinfin shiner), Rhinichthys atratulus (blacknose dace), Catostomus comme-soni (white sucker), Lepomis gibbosus (pumpkinseed). and Micropterous salmoides (largemouth bass). It was found that by applying only USEPA suggested criteria that a complete evaluation was not satisfactory. Temperature behavior data, specifically preference and avoidance information, coupled with field sampliug was needed to properly assess the effects of the thermal effluent. The final analysis indicated that the thermal discharge of the paper company should have minimal effect on the fish community of Codorus Creek.  相似文献   
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