Hydrogen defects in α-Al2O3 and water weakening of sapphire and alumina ceramics between 600°C and 1000°C: II. Mechanical properties
J. Castaing, A. K. Kronenberg, S. H. Kirby, T. E. Mitchell
2000, Acta Materialia (48) 1495-1504
Hydrogen impurities in alumina have been introduced by hydrothermal annealing (see part I). In this paper, we report on reductions in the flow strength of α-Al2O3 single crystals and polycrystals associated with hydrogen incorporation. Prior to deformation, α-Al2O3 single crystal and ceramic specimens were annealed in the presence of supercritical water at 850° or...
New site coefficients and site classification system used in recent building seismic code provisions
R. Dobry, R. D. Borcherdt, C.B. Crouse, I.M. Idriss, W. B. Joyner, G. R. Martin, M.S. Power, E.E. Rinne, R.B. Seed
2000, Earthquake Spectra (16) 41-67
Recent code provisions for buildings and other structures (1994 and 1997 NEHRP Provisions, 1997 UBC) have adopted new site amplification factors and a new procedure for site classification. Two amplitude-dependent site amplification factors are specified: Fa for short periods and Fv for longer periods. Previous codes included only a...
Distribution of trace elements in selected pulverized coals as a function of particle size and density
C.L. Senior, T. Zeng, J. Che, M.R. Ames, A.F. Sarofim, I. Olmez, Frank E. Huggins, N. Shah, G.P. Huffman, A. Kolker, S. Mroczkowski, C. Palmer, R. Finkelman
2000, Fuel Processing Technology (63) 215-241
Trace elements in coal have diverse modes of occurrence that will greatly influence their behavior in many coal utilization processes. Mode of occurrence is important in determining the partitioning during coal cleaning by conventional processes, the susceptibility to oxidation upon exposure to air, as well as the changes in physical...
Evaluation of a 16-inch minimum length limit for smallmouth bass in Pallette Lake, Wisconsin
S.P. Newman, M.H. Hoff
2000, North American Journal of Fisheries Management (20) 90-99
We evaluated a 16-in minimum length limit and two-fish daily bag limit for smallmouth bass Micropterus dolomieu in Pallette Lake, Wisconsin, from 1989 to 1996. Fish abundance, biomass, growth, survival, and angler harvest were compared with data from years when no length or bag limits were in force. Angler harvest...
North-south geological differences between the residual polar caps on Mars
P.C. Thomas, M. C. Malin, K.S. Edgett, M. H. Carr, W.K. Hartmann, A.P. Ingersoll, P.B. James, L.A. Soderblom, J. Veverka, R. Sullivan
2000, Nature (404) 161-164
Polar processes can be sensitive indicators of global climate, and the geological features associated with polar ice caps can therefore indicate evolution of climate with time. The polar regions on Mars have distinctive morphologic and climatologic features: thick layered deposits, seasonal CO2 frost caps extending to mid latitudes, and near-polar...
Generation of data acquisition requests for the ASTER satellite instrument for monitoring a globally distributed target: glaciers
B.H. Raup, H. H. Kieffer, T.M. Hare, J.S. Kargel
2000, IEEE Transactions on Geoscience and Remote Sensing (38) 1105-1112
The advanced spaceborne thermal emission and reflection radiometer (ASTER) instrument is scheduled to be launched on the EOS Terra platform in 1999. The Global Land Ice Measurements from Space project has planned to acquire ASTER images of most of the world's land ice annually during the six-year ASTER mission. This...
Consequences of slow growth for 230Th/U dating of Quaternary opals, Yucca Mountain, NV, USA
L.A. Neymark, J.B. Paces
2000, Chemical Geology (164) 143-160
Thermal ionization mass-spectrometry 234U/238U and 230Th/238U data are reported for uranium-rich opals coating fractures and cavities within the silicic tuffs forming Yucca Mountain, NV, the potential site of a high-level radioactive waste repository. High uranium concentrations (up to 207 ppm) and extremely high 230Th/232Th activity ratios (up to about 106)...
Whole-lake burdens and spatial distribution of cadmium in sediments of Wisconsin seepage lakes, USA
D.E. Powell, R.G. Rada, J.G. Wiener, G.J. Atchison
2000, Environmental Toxicology and Chemistry (19) 1523-1531
Cadmium was quantified in the surface sediments of six seepage lakes ranging from 8 to 70 ha in surface area, 6 to 20 m in maximum depth, 5.2 to 7.0 in mean epilimnetic pH, and 1.7 to 6.8 mg·L−1 in dissolved organic carbon. Within each lake, dry-weight concentrations of cadmium (range,...
Mapping forest canopy gaps using air-photo interpretation and ground surveys
T.J. Fox, M. G. Knutson, R. K. Hines
2000, Wildlife Society Bulletin (28) 882-889
Canopy gaps are important structural components of forested habitats for many wildlife species. Recent improvements in the spatial accuracy of geographic information system tools facilitate accurate mapping of small canopy features such as gaps. We compared canopy-gap maps generated using ground survey methods with those derived from air-photo interpretation. We...
Genetic diversity and epidemiology of infectious hematopoietic necrosis virus in Alaska
E.G Emmenegger, T.R. Meyers, T.O. Burton, Gael Kurath
2000, Diseases of Aquatic Organisms (40) 163-176
Forty-two infectious hematopoietic necrosis virus (IHNV) isolates from Alaska were analyzed using the ribonuclease protection assay (RPA) and nucleotide sequencing. RPA analyses, utilizing 4 probes, N5, N3 (N gene), GF (G gene), and NV (NV gene), determined that the haplotypes of all 3 genes demonstrated a consistent spatial pattern. Virus...
Intra- and inter-unit variation in fly ash petrography and mercury adsorption: Examples from a western Kentucky power station
J.C. Hower, R. B. Finkelman, R.F. Rathbone, J. Goodman
2000, Energy and Fuels (14) 212-216
Fly ash was collected from eight mechanical and 10 baghouse hoppers at each of the twin 150-MW wall-fired units in a western Kentucky power station. The fuel burned at that time was a blend of many low-sulfur, high-volatile bituminous Central Appalachian coals. The baghouse ash showed less variation between units...
Sorption of selected organic compounds from water to a peat soil and its humic-acid and humin fractions: Potential sources of the sorption nonlinearity
C. T. Chiou, D. E. Kile, D.W. Rutherford, G. Sheng, S.A. Boyd
2000, Environmental Science & Technology (34) 1254-1258
The sorption isotherms of ethylene dibromide (EDB), diuron (DUN), and 3,5-dichlorophenol (DCP) from water on the humic acid and humin fractions of a peat soil and on the humic-acid of a muck soil have been measured. The data were compared with those of the solutes with the whole peat from...
Geology of the Uranius Group Volcanic Constructs: Uranius Patera, Ceraunius Tholus, and Uranius Tholus
J. B. Plescia
2000, Icarus (143) 376-396
Uranius Patera, Ceraunius Tholus, and Uranius Tholus (three small constructs in the northeast Tharsis region) date to the Late Hesperian Epoch and define the earliest phases of constructional volcanism in the Tharsis province. All three volcanoes are interpreted as shields, built by effusive eruptions of low-viscosity lavas, presumably basalt. Ceraunius...
An unstructured grid, three-dimensional model based on the shallow water equations
V. Casulli, R. A. Walters
2000, International Journal for Numerical Methods in Fluids (32) 331-348
A semi-implicit finite difference model based on the three-dimensional shallow water equations is modified to use unstructured grids. There are obvious advantages in using unstructured grids in problems with a complicated geometry. In this development, the concept of unstructured orthogonal grids is introduced and applied to this model. The governing...
Physiological measures of neurotoxicity of diazinon and malathion to larval rainbow trout (Oncorhynchus mykiss) and their correlation with behavioral measures
S.L. Beauvais, S.B. Jones, S.K. Brewer, E. E. Little
2000, Environmental Toxicology and Chemistry (19) 1875-1880
Relations between neurotoxicants and changes in physiological parameters and behavior were investigated in larval rainbow trout (RBT; Oncorhynchus mykiss) exposed to sublethal concentrations of two organophosphate pesticides (OPs). Fish were exposed to diazinon and malathion in static-renewal experiments. After exposures for 24, 96, or 96 h, followed by 48 h...
Downed wood in Micronesian mangrove forests
J. A. Allen, K. C. Ewel, B. D. Keeland, T. Tara, T. J. Smith III
2000, Wetlands (20) 169-176
Dead, downed wood is an important component of upland forest and aquatic ecosystems, but its role in wetland ecosystems, including mangroves, is poorly understood. We measured downed wood in ten sites on the western Pacific islands of Kosrae, Pohnpei, and Yap, all located within the Federated States of Micronesia. Our...
Swimming performance of larval robust redhorse Moxostoma robustum and low-velocity habitat modeling in the Oconee River, Georgia
Carl R. Ruetz III, Cecil A. Jennings
2000, Transactions of the American Fisheries Society (129) 398-407
The robust redhorse Moxostoma robustum occurs in an 85-km stretch of the Oconee River, Georgia, downstream of a hydropower dam. The population consists primarily of older individuals and recruitment in recent years has been minimal. Operation of the hydropower dam may have affected recruitment negatively by displacing newly hatched larvae...
Invasion by a Japanese marine microorganism in western North America
M. McGann, D. Sloan, A.N. Cohen
2000, Hydrobiologia (421) 25-30
The earliest record in western North America of Trochammina hadai Uchio, a benthic foraminifer common in Japanese estuaries, is from sediment collected in Puget Sound in 1971. It was first found in San Francisco Bay in sediment samples taken in 1983, and since 1986 has been collected at 91% of...
Estimation of hydrocarbon biodegradation rates in gasoline-contaminated sediment from measured respiration rates
R.J. Baker, A. L. Baehr, M.A. Lahvis
2000, Journal of Contaminant Hydrology (41) 175-192
An open microcosm method for quantifying microbial respiration and estimating biodegradation rates of hydrocarbons in gasoline-contaminated sediment samples has been developed and validated. Stainless-steel bioreactors are filled with soil or sediment samples, and the vapor-phase composition (concentrations of oxygen (O2), nitrogen (N2), carbon dioxide (CO2), and selected hydrocarbons) is monitored...
Mode of occurrence of arsenic in four US coals
A. Kolker, Frank E. Huggins, C.A. Palmer, N. Shah, S.S. Crowley, G.P. Huffman, R. B. Finkelman
2000, Fuel Processing Technology (63) 167-178
An integrated analytical approach has been used to determine the mode of occurrence of arsenic in samples of four widely used US coals: the Pittsburgh, Illinois #6, Elkhorn/Hazard, and Wyodak. Results from selective leaching, X-ray absorption fine structure (XAFS) spectroscopy, and electron microprobe analysis show that pyrite is the principal...
Origin of Amazon mudbanks along the northeastern coast of South America
M. A. Allison, M.T. Lee, A.S. Ogston, R.C. Aller
2000, Marine Geology (163) 241-256
Seismic profiles, sediment cores, and water column measurements were collected along the northeastern coast of Brazil to examine the origin of mudbanks in the Amazon coastal mud belt. These 10-60-km-long, shore-attached features previously had been observed to migrate along the 1200 km coast of the Guianas in response to wave...
A surface-associated activity trap for capturing water-surface and aquatic invertebrates in wetlands
Mark A. Hanson, Christiane C. Roy, Ned Euliss, Kyle D. Zimmer, Michael R. Riggs, Malcolm G. Butler
2000, Wetlands (20) 205-212
We developed a surface-associated activity trap (SAT) for sampling aquatic invertebrates in wetlands. We compared performance of this trap with that of a conventional activity trap (AT) based on non-detection rates and relative abundance estimates for 13 taxa of common wetland invertebrates and for taxon richness using data from experiments...
Seasonal movements and pelagic habitat use of Murres and Puffins determined by satellite telemetry
Scott A. Hatch, P.M. Meyers, D.M. Mulcahy, David C. Douglas
2000, Condor (102) 145-154
We tracked the movements of Common Murres (Uria aalge), Thick-billed Murres (U. lomvia), and Tufted Puffins (Fratercula cirrhata) using surgically implanted satellite transmitters. From 1994–1996, we tagged 53 birds from two colonies in the Gulf of Alaska (Middleton Island and Barren Islands) and two colonies in the Chukchi Sea (Cape...
Using supplemental food and its influence on survival of northern bobwhite (Colinus virginianus)
D.E. Townsend II, R.L. Lochmiller, Stephen J. DeMaso, David M. Leslie Jr., A.D. Peoples, A C. Scott, E.S. Parry
2000, Wildlife Society Bulletin (27) 1074-1081
Biologists have debated the effectiveness of supplemental feeders as a management tool for the northern bobwhite (Colinus virginianus), but few extensive evaluations have been conducted. We examined 783 crops from harvested bobwhites during 1992-1996 to determine effects of climatic stress in winter on use of supplemental feeders and their impact...
Use of field-applied quality control samples to monitor performance of a Goulden large-sample extractor/GC-MS method for pesticides in water
W.T. Foreman, Paul M. Gates, G.D. Foster, F. A. Rinella, S. W. McKenzie
2000, International Journal of Environmental Analytical Chemistry (77) 39-62
Since 1985, the Goulden large-sample extractor (GLSE) has been used to isolate a broad array of trace-organic contaminants from large volumes of water. In this study, field-applied quality control measures, including matrix and surrogate spikes and blanks, were used to monitor method performance from GLSE extraction through GC-MS analysis. The...
