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991.
992.
This paper analyses the extent to which the new Reagan mineral policy will encourage increased US production, substitution, recycling and conservation, domestic stock-piling and diversification of foreign supplies. Major inadequacies of the mineral policy are the transfer of responsibility for research and development from the government to the unprepared private sector, the lack of emphasis on short-term research and development in mineral processing technology, and the lack of coordination between minerals policy and national security and foreign policy. However, overall the policy is a positive step towards reducing the current US minerals supply vulnerability. 相似文献
993.
994.
995.
Terence P. Curran Thomas W. King 《Journal of the American Water Resources Association》1974,10(1):127-136
ABSTRACT The National Environmental Policy Act of 1969, has been called a revolutionary piece of legislation. It has changed, and is still changing the traditional ways of governmental decision-making. NEPA has strongly influenced the field of water resources management. An environmental statement can now be seen not as a document to support or justify a plan, but an objective assessment of what environmental costs and benefits are involved. New York State has seized upon NEPA as an important feature of its environmental quality management programs and has used the opportunity to comment upon draft environmental statements under NEPA to increase its influences upon Federal decision-making. The Department of Environmental Conservation coordinates and synthesizes all comments and provides one unified State response on a statement. At the State level, lacking a comprehensive “little NEPA”, an extensive environmental analysis program has been built by utilizing a wide spectrum of Federal and State Laws and administrative regulations. 相似文献
996.
Herbert M. Runkle Thomas H. Perkins 《Journal of the American Water Resources Association》1971,7(2):348-354
Time is running out on this country's planners. Generally speaking, the art of planning has retrogressed since the time of Christ. If we are to survive, this will have to be drastically changed by the year 2000. To achieve this, we need to begin to change our thinking, today. We badly need wider social planning, giving us more alternatives-more thought on where we are going. Reasonableness requires blending of planning and construction-but a sharp line of independence is essential. We must think about all the consequences of a particular act. Through intensive professional development and achievement of professional expertise, many outstanding technicians often move into vital decision making positions within their respective agencies. As planners, they see a part of the action but miss the big picture. Problem solutions become restricted to agency or individual authorities and are not always the best alternative. Thus, the planning field is overflowing with solutions to our every problem but many solutions offer spot control, and while the black spot is removed from the garment the white spot remaining from the solution offers little consolation to the wearer. 相似文献
997.
Release of dissolved organic matter from natural populations of marine phytoplankton 总被引:1,自引:0,他引:1
J. P. Thomas 《Marine Biology》1971,11(4):311-323
A new method is presented for measuring the rate of release of dissolved organic matter (DOM) produced by natural populations of marine phytoplankton. The method has been field-tested using natural populations of estuarine, coastal, and oceanic phytoplankton. Problems associated with the necessity for long incubation times, high initial activity of the inorganic 14C added to the sample, and self-absorption are overcome. Improved sensitivity is obtained by utilizing a large portion of the sample filtrate, Results from sampling at different times of day and for different lengths of incubation suggest that these problems should be reexamined in terms of both the percent and rate of relase of DOM from natural populations of phytoplankton. The rate of release of DOM from natural populations of marine phytoplankton decreases seaward. Phytoplankton in Georgia (USA) estuaries release <1 to 40 mg C m-3 day-1, in southeastern USA coastal waters from 0 to 19 mg C m-3 day-1, and in the westernmost Sargasso Sea from 0 to 2 mg C m-3 day-1. The percent of photoassimilated carbon released as DOM increases seaward. The percents are less than 7% in the Georgia estuaries, generally less than 13% in southeastern USA surface coastal waters, generally less than 21% for these coastal waters below the surface, and less than 44% for the westernmost Sargasso Sea. The results of this study and of other studies suggest that the measurement of primary productivity in estuarine and nearshore coastal waters is not seriously in error because of the absence of measurements on the rate of release of DOM from such phytoplankton. However, the estimation of primary-productivity values for oceanic waters is underestimated in some cases by about 50%.Contribution No. 595 from the Department of Oceanography, University of Washington, Seattle, Washington, USA and Contribution No. 224 from the University of Georgia Marine Institute, Sapelo Island, Georgia, USA.Extracted in part from a dissertation submitted to the Graduate Faculty of the University of Georgia in partial fulfillment of the requirements for the degree of Doctor of Philosophy. 相似文献
998.
999.
Method for determination of methane potentials of solid organic waste 总被引:15,自引:0,他引:15
Hansen TL Schmidt JE Angelidaki I Marca E Jansen Jl Mosbaek H Christensen TH 《Waste management (New York, N.Y.)》2004,24(4):393-400
A laboratory procedure is described for measuring methane potentials of organic solid waste. Triplicate reactors with 10 grams of volatile solids were incubated at 55 degrees C with 400 ml of inoculum from a thermophilic biogas plant and the methane production was followed over a 50-day period by regular measurements of methane on a gas chromatograph. The procedure involves blanks as well as cellulose controls. Methane potentials have been measured for source-separated organic household waste and for individual waste materials. The procedure has been evaluated regarding practicality, workload, detection limit, repeatability and reproducibility as well as quality control procedures. For the source-separated organic household waste a methane potential of 495 ml CH4/g VS was found. For fat and oil a lag-phase of several days was seen. The protein sample was clearly inhibited and the maximal methane potential was therefore not achieved. For paper bags, starch and glucose 63, 84 and 94% of the theoretical methane potential was achieved respectively. A detection limit of 72.5 ml CH4/g VS was calculated from the results. This is acceptable, since the methane potential of the tested waste materials was in the range of 200-500 ml CH4/g VS. The determination of methane potentials is a biological method subject to relatively large variation due to the use of non-standardized inoculum and waste heterogeneity. Therefore, procedures for addressing repeatability and reproducibility are suggested. 相似文献
1000.
Gamma-ray spectrometric systems carried by helicopters prove to be indispensable for the surveillance of environmental radioactivity. The aerial measurements are an important tool for rapid and large-scale nuclide specific determination of soil contamination after an accidental release of radionuclides from a nuclear facility. Furthermore this technique is also applied for the determination of anomalies of elevated radioactivity of natural radionuclides, the detection of lost radioactive sources and geological mapping. For the measurements the helicopters are equipped with a NaI(Tl)-detector array and a high purity germanium-semiconductor (HPGe) detector. Especially with the HPGe-detector it is possible to clearly identify individual radionuclides. To improve and to guarantee the quality of this method several exercises with different fields of interest have been carried out during the last years. Thereby the main focus is on the improvement of the instrumentation, data handling and data analysis. The results of the airborne radionuclide measurements from the Black Forest which was performed in co-operation with the Swiss National Emergency Operation Centre, are presented here. During this exercise the gamma dose rate, soil contamination due to 137Cs and the specific activities of natural radionuclides in soil were determined. 相似文献