11,583 research outputs found
FACILITATION OF DECOMMISSIONING LIGHT WATER REACTORS
Information on design features, special equipment, and construction methods useful in the facilitation of decommissioning light water reactors is presented in this report. A wide range of facilitation methods--from improved documentation to special decommissioning tools and techniques--is discussed. In addition, estimates of capital costs, cost savings, and radiation dose reduction associated with these facilitation methods are given
Controlled Ecological Life Support System. First Principal Investigators Meeting
Control problems in autonomous life support systems, CELSS candidate species, maximum grain yield, plant growth, waste management, air pollution, and mineral separation are discussed
Feasibility study ASCS remote sensing/compliance determination system
A short-term technical study was performed by the MSC Earth Observations Division to determine the feasibility of the proposed Agricultural Stabilization and Conservation Service Automatic Remote Sensing/Compliance Determination System. For the study, the term automatic was interpreted as applying to an automated remote-sensing system that includes data acquisition, processing, and management
Calcium carbonate, opal, and quartz in Holocene pelagic sediments and the calcite compensation level in the South Atlantic Ocean
Calcium carbonate is the dominant component in the pelagic sediments of the South Atlantic; its distribution pattern can be explained by use of bottom-water circulation. Biogenous opal concentrations occur in two bands, near the Equator and around 50°S; these concentrations are associated with zones of high biological productivity in surface waters...
The DEF’s of LIGA: An Update to the ABC’s of LIGA
The article offers information on ABC\u27s of Louisiana Insurance Guaranty Association (LIGA), and discusses its role in interpreting and understanding the law applicable to the LIGA, and discusses its benefits to legal practitioners
Nutrient Content of Runoff Water From Rice Fields
Current perception is that nutrient runoff from croplands is a significant contributor to poor water quality in some areas. While extensive research has been conducted to survey and ameliorate this problem for several upland crops, little work has been done to evaluate the problem with flooded rice (Oryza sativa, L.) soils. Since rice production utilizes a major portion of the total irrigation water usage for certain areas, it is important to understand the contribution of rice production to non-point source N and P in surface water. Several production fields were selected to evaluate the concentrations of nutrients in the floodwater at selected distances across the field, including inlet and exit. The fields were evaluated in either 1990, 1991, or 1992 and were managed by the individual rice producer. Water samples were collected from several locations within each field weekly following establishment of the permanent flood and analyzed for inorganic N (NH4-N, No3-N, and NO2-N) and soluble P. The N concentrations in the floodwater normally peaked following N fertilizer application but rapidly declined and remained below 1 mg N L-1. Water management resulted in some variation among locations with respect to the timing and magnitude of these peaks. The P concentrations were usually highest near the well and declined to less than 0.05 mg P L-1 as the water moved across the field. This was attributed to plant uptake, uptake by algae, and sediment deposition. The data indicates that rice fields have the potential to be utilized as a filtration system to reduce the nutrient load of irrigation water similar to constructed wetlands . Use of catfish pondwater, in comparison to well water, resulted in only slightly higher total N and total P levels with higher amounts of the nutrients in the organic form. Although the P levels were high enough to potentially contribute to eutrophication of surface water, the water exiting the field was lower than at the entry point irrespective of the source. Also, the total P (organic + inorganic) concentration was less than 0.05 mg P L- 1
Efficiency and Stability Issues in the Numerical Computation of Fourier Transforms and Convolutions on the 2-Sphere
Earlier work by Driscoll and Healy has produced an efficient algorithm for computing the Fourier transform of band-limited functions on the sphere. In this paper we present a greatly improved inverse transform, and consequent improved convolution algorithm for such functions. We also discuss implementational considerations and give heuristics for allowing reliable floating point implementations of a slightly modified algorithm at little cost in either theoretical or actual performance. This discussion is supplemented with numerical experiments from our implementation in C on a DecStation 5000. These results give strong indications that the algorithm is both reliable and efficient for a large range of useful problem sizes
Methods for comparative evaluation of propulsion system designs for supersonic aircraft
The propulsion system comparative evaluation study was conducted to define a rapid, approximate method for evaluating the effects of propulsion system changes for an advanced supersonic cruise airplane, and to verify the approximate method by comparing its mission performance results with those from a more detailed analysis. A table look up computer program was developed to determine nacelle drag increments for a range of parametric nacelle shapes and sizes. Aircraft sensitivities to propulsion parameters were defined. Nacelle shapes, installed weights, and installed performance was determined for four study engines selected from the NASA supersonic cruise aircraft research (SCAR) engine studies program. Both rapid evaluation method (using sensitivities) and traditional preliminary design methods were then used to assess the four engines. The method was found to compare well with the more detailed analyses
Sediment budget in a deep-sea core from the central equatorial Pacific
Stratigraphic, mineralogic, chemical, and geochronologic measurements on a core from 8°20\u27N, 153°W show that sediment has been accumulating at a rate of 160 g/cm2/106 years. Of this, 125 g is fresh Quaternary sediment while the remainder is lower and middle Tertiary material eroded from nearby outcrops...
Relationship between ferromanganese nodule compositions and sedimentation in a small survey area of the equatorial Pacific
The bulk chemical compositions of ferromanganese nodules recovered from 14 of 38 sediment cores collected from a 230 km2 area of abyssal hill topography in the northern equatorial Pacific (8°20\u27N; 153W; regional depth 5000m) vary nonrandornly between fairly wide limits. The nodules have Mn/Fe ratios ranging from 2.60 to 5.38 and all samples contain todorokite and 8-MnO2. The variation in the Mn/Fe ratio is governed by the total Fe contents of the nodules; Mn varies to a much smaller extent. Cu and Ni contents average about 1% and vary independently of the Mn contents...
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