The objective of this multiyear effort was the development, fabrication and testing of a zirconia oxygen production module capable of delivering approximately 100 liters/minute (LPM) of oxygen. The work discussed in this report consists of development and improvement of the zirconia cell along with manufacture of cell components, preliminary design of the final plant, additional economic analysis and industrial participation. (VC)

The objective of this multiyear effort was the development, fabrication and testing of a zirconia oxygen production module capable of delivering approximately 100 liters/minute (LPM) of oxygen. The work discussed in this report consists of development and improvement of the zirconia cell along with manufacture of cell components, preliminary design of the final plant, additional economic analysis and industrial participation. (VC)

The increasing availability of digital elevation data (DED) created from remotely sensed data has promoted the development of computer algorithms for the calculation of geomorphometric properties of the land surface. These include parameters that are tedious or impossible to do by hand, for example, stream properties by order and flow path mapping for every location within the drainage basin. Flow paths especially are critical for water routing in hydrologic models. These algorithms can be used to explore spatial trends in landscape properties as a function of rock type, climate or neotectonic environment. The DED can be readily linked with a geographic information system (GIS) which is used to parameterize a quasi-physically based surface runoff model. Various representations (Shreve orders) of the watershed are created by simplifying a stream network delineated from the DED. Different Shreve orders produce significantly different geomorphometrics that affect simulated runoff volumes. At one of the study sites, the DED are not of sufficient detail to allow stream network extraction. Therefore, classification of SPOT panchromatic data was used to delineate ephemeral, fluvial networks on this low-relief, arid basin. A one pixel proximity search classified correctly over 80 percent of the channelized flow. 3 figs., 2 tabs.

Pacific Northwest Laboratory (PNL) and Westinghouse Hanford Company (Westinghouse Hanford) are collaborating on a field study of the effects of gravel admixtures on plant growth and soil water storage in protective barriers. Protective barriers are engineered earthern covers designed to prevent water, plants, and animals from contacting buried waste and transporting contaminants to groundwater or the land surface. Some of the proposed designs include gravel admixtures or gravel mulches on the barrier surface to control soil loss by wind and runoff. The purpose of this study is to measure, in a field setting, the influence of surface gravel additions on soil water storage and plant cover. The study plots are located northwest of the Yakima Gate in the McGee Ranch old field. Here we report the status of work completed in FY 1989 on the creation of a data management system, a test of water application uniformity, field calibration of neutron moisture gages, and an analysis of the response of plants to various combinations of gravel admixtures and increased rainfall. 23 refs., 11 figs., 6 tabs.

X-ray computed tomography is a useful tool for investigating soil physical properties nondestructively. There is a need to develop proper calibration relationships between soil properties and the x-ray absorption coefficient. The objective of the work was to evaluate soil factors affecting the x-ray absorption coefficient. Based on a theoretical analysis, experimental data from five soils and on results of several other investigators, it was concluded that for many applications, one calibration relationship is applicable to a wide range of soils. The montmorillinitic clay used in the study required special handling due to the extreme shrinkage of this soil upon drying. Knowledge of chemical composition enables approximations but not exact predictions of the x-ray absorption coefficient. The results suggested some reasonable alternative to exhaustive calibration for each anticipated soil condition. Quantification of root activity in terms of root growth and indirectly through water uptake is necessary for understanding plant growth dynamics. X-ray computed tomography (CT) enables qualitative as well as two quantitative outputs, one of which can lead to conclusions regarding root activity. A greenhouse study involving soil columns (Lakeland sand, bulk density 1.4 Mg/m{sup 3}) planted to soybean, Bahiagras, and control (no vegetation) was conducted in 1989. A treflan based …

Municipal solid waste (MSW) represents both a significant problem and an abundant resource for the production of energy. The residential, institutional, and industrial sectors of this country generate about 250 million tons of MSW each year. In this report, the authors have compiled data on the status of MSW in the 13-state western region, including economic and environmental issues. The report is designed to assist the members of the Western Regional Biomass Energy Program Ad Hoc Resource Committee in determining the potential for using MSW to produce energy in the region. 51 refs., 7 figs., 18 tabs.

The sintering of ZnO varistor precursor powders, doped with Co, Mn and different concentrations of Bi and Al, is investigated and discussed in relation with sintering models. One purpose of the present study is to provide information valuable for the fabrication of high field varistors. As the fundamental parameter of these electronic components is the breakdown voltage per unit of thickness, which is determined by the number of grain boundaries per linear dimension, the grain size and the sintered density are crucial variables, and the sintering is a central step in the manufacturing of such varistors. Sintering experiments performed at constant heating rate in a loading dilatometer provide data on the densification and creep of the compacted powders. Another goal of the present study is to provide an experimental basis for the interpretation of the evolution of the ratio between densification rate and creep rate in terms of competition between densification and microstructure coarsening. This is accomplished by taking advantage of the variety of sintering behaviors that takes place in the system ZnO-Bi-Al: the comparison of these behaviors allows us to correlate the macroscopic sintering parameters to the evolution of the microstructure. It results that, while in non-doped powders densification …

The primary purpose of this study was to evaluate which small mammal species are the best monitors of specific environmental contaminants. The evaluation is based on the published literature and on an analysis of small mammals trapped at several sites on the Oak Ridge National Laboratory (ORNL) Reservation in Oak Ridge, Tennessee. Studies on the uptake of heavy metals, radionuclides, and organic chemicals are reviewed in Chapter II to evaluate several small mammal species for their capacity to serve as sentinels for the presence, accumulation, and effects of various contaminants. Where several species were present at a site, a comparative evaluation was made and species are ranked for their capacity to serve as monitors of specific contaminants. Food chain accumulation and food habits of the species are used to establish a relationship with suitability as a biomonitor. Tissue-specific concentration factors were noted in order to establish target tissues. Life histories, habitat, and food habits are reviewed in order to make generalizations concerning the ability of similar taxa to serve as biomonitor. Finally, the usefulness of several small mammal species as monitors of three contaminants -- benzo(a)pyrene, mercury, and strontium-90 -- present on or near the ORNL facilities was investigated. 133 …