Multiphase flow in geometrically simple fracture intersections
H. Basagaoglu, P. Meakin, C.T. Green, M. Mathew
Boghosian B.M., editor(s)
2006, Physica A: Statistical Mechanics and its Applications (362) 17-22
A two-dimensional lattice Boltzmann (LB) model with fluid-fluid and solid-fluid interaction potentials was used to study gravity-driven flow in geometrically simple fracture intersections. Simulated scenarios included fluid dripping from a fracture aperture, two-phase flow through intersecting fractures and thin-film flow on smooth and undulating solid surfaces. Qualitative comparisons with recently...
Useful ion yields for Cameca IMS 3f and 6f SIMS: Limits on quantitative analysis
R.L. Hervig, F.K. Mazdab, Pat Williams, Y. Guan, G.R. Huss, L.A. Leshin
2006, Chemical Geology (227) 83-99
The useful yields (ions detected/atom sputtered) of major and trace elements in NIST 610 glass were measured by secondary ion mass spectrometry (SIMS) using Cameca IMS 3f and 6f instruments. Useful yields of positive ions at maximum transmission range from 10-4 to 0.2 and are negatively correlated with ionization potential....
The effect of multiple stressors on salt marsh end-of-season biomass
J.M. Visser, C.E. Sasser, B.S. Cade
2006, Estuaries and Coasts (29) 328-339
It is becoming more apparent that commonly used statistical methods (e.g., analysis of variance and regression) are not the best methods for estimating limiting relationships or stressor effects. A major challenge of estimating the effects associated with a measured subset of limiting factors is to account for the effects of...
Spatial organization of a reintroduced population of bobcats
Duane R. Diefenbach, L.A. Hansen, R.J. Warren, M.J. Conroy
2006, Journal of Mammalogy (87) 394-401
The spacing patterns and mating systems of solitary carnivores have important implications for social behavior and for the survival and reproduction of individuals. Over 2 years, we reintroduced 32 (15 males and 17 females) bobcats (Lynx rufus) to a barrier island off the coast of Georgia and studied patterns of...
Regional patterns in the isotopic composition of natural and anthropogenic nitrate in groundwater, High Plains, U.S.A.
P.B. McMahon, J.K. Böhlke
2006, Environmental Science & Technology (40) 2965-2970
Mobilization of natural nitrate (NO3-) deposits in the subsoil by irrigation water in arid and semiarid regions has the potential to produce large groundwater NO3- concentrations. The use of isotopes to distinguish between natural and anthropogenic NO3- sources in these settings could be complicated by the wide range in δ15N...
Geophysical monitoring of a field-scale biostimulation pilot project
J.W. Lane Jr., F. D. Day-Lewis, C.C. Casey
2006, Ground Water (44) 430-443
The USGS conducted a geophysical investigation in support of a U.S. Naval Facilities Engineering Command, Southern Division field‐scale biostimulation pilot project at Anoka County Riverfront Park (ACP), downgradient of the Naval Industrial Reserve Ordnance Plant, Fridley, Minnesota. The goal of the pilot project is to evaluate...
Simulation of solute transport across low-permeability barrier walls
P. T. Harte, Leonard F. Konikow, G.Z. Hornberger
2006, Journal of Contaminant Hydrology (85) 247-270
Low-permeability, non-reactive barrier walls are often used to contain contaminants in an aquifer. Rates of solute transport through such barriers are typically many orders of magnitude slower than rates through the aquifer. Nevertheless, the success of remedial actions may be sensitive to these low rates of transport. Two numerical simulation...
Vascular flora of Izembek National Wildlife Refuge, westernmost Alaska Peninsula, Alaska
Stephen S. Talbot, Sandra Looman Talbot, Wilfred B. Schofield
2006, Rhodora (108) 249-293
The vascular flora of Izembek National Wildlife Refuge (NWR), where few previous collections had been reported, was collected and recorded at sites selected to represent the totality of environmental variation. A total of 349 species (339 native and 10 introduced) was identified. To provide a comparative phytogeographic framework, we analyzed...
Spatial and temporal dynamics of microcystin in a Missouri reservoir
J.L. Graham, J.R. Jones, S.B. Jones, T.E. Clevenger
2006, Lake and Reservoir Management (22) 59-68
Environmental factors associated with spatiotemporal variation of microcystin (MC) in Mozingo Lake, a Missouri reservoir, were studied during summer 2001, and annual MC trends were characterized from May 2001-May 2002. MC increased during summer, ranging from 20 to 1220 ng/L. Seasonal patterns in MC corresponded with chlorophyll>35 ??m (Net Chl)...
Bobcat attack on a cottontail rabbit
E. Biggins, D.M. Biggins
2006, Southwestern Naturalist (51) 119-122
We observed an attack by a bobcat (Lynx rufus) on a cottontail rabbit (Sylvilagus) that involved stealthy approach by the cat for >1 h, followed by a 12.3-s chase covering 116.0 m for the cat and 128.4 m for the rabbit. During the chase, the route of the cat from...
Studies on stoneflies (Plecoptera) of Colorado with eastern faunal affinities, including a new state record of the midwestern salmonfly, Pteronarcys pictetii hagen (Plecoptera: Pteronarcyidae)
R.E. Zuellig, B.C. Kondratieff, R.W. Hood
2006, Proceedings of the Entomological Society of Washington (108) 335-340
Pteronarcys pictetii Hagen nymphs were collected and reared from the South Platte River at Julesburg in eastern Colorado. Including P. pictetii, eight species are now known from Colorado that exhibit eastern North American affinities, Paracapnia angulata Hanson, Taeniopteryx burksi Ricker and Ross, Taeniopteryx parvula Banks, Acroneuria abnormis (Newman), Perlesta decipiens...
Palynology and age of some Cretaceous nonmarine deposits in Mongolia and China
D. J. Nichols, M. Matsukawa, M. Ito
2006, Cretaceous Research (27) 241-251
To provide biostratigraphic and paleoecologic data for a major international project studying dinosaur trackways in eastern Asia, samples were collected for palynological analysis from the Choyr Basin of southeastern Mongolia and the Yanji Basin, Jilin Province, northeastern China. Palynologically productive samples from the Choyr Basin are from strata previously identified...
Sample size and the detection of a hump-shaped relationship between biomass and species richness in Mediterranean wetlands
J. L. Espinar
2006, Journal of Vegetation Science (17) 227-232
Questions: What is the observed relationship between biomass and species richness across both spatial and temporal scales in communities of submerged annual macrophytes? Does the number of plots sampled affect detection of hump-shaped pattern? Location: Don??ana National Park, southwestern Spain. Methods: A total of 102 plots were sampled during four...
Bias and uncertainty in regression-calibrated models of groundwater flow in heterogeneous media
R.L. Cooley, S. Christensen
2006, Advances in Water Resources (29) 639-656
Groundwater models need to account for detailed but generally unknown spatial variability (heterogeneity) of the hydrogeologic model inputs. To address this problem we replace the large, m-dimensional stochastic vector ?? that reflects both small and large scales of heterogeneity in the inputs by a lumped or smoothed m-dimensional approximation ????*,...
Side channel mapping and fish habitat suitability analysis using LIDAR topography and orthophotography
J. L. Jones
2006, Photogrammetric Engineering and Remote Sensing (71) 1202-1206
No abstract available....
Habitat use by a Midwestern U.S.A. riverine fish assemblage: effects of season, water temperature and river discharge
D.P. Gillette, J.S. Tiemann, D.R. Edds, M. L. Wildhaber
2006, Journal of Fish Biology (68) 1494-1512
The hypothesis that temperate stream fishes alter habitat use in response to changing water temperature and stream discharge was evaluated over a 1 year period in the Neosho River, Kansas, U.S.A. at two spatial scales. Winter patterns differed from those of all other seasons, with shallower water used less frequently,...
Cotectic proportions of olivine and spinel in olivine-tholeiitic basalt and evaluation of pre-eruptive processes
Peter Roeder, Emma Gofton, Carl Thornber
2006, Journal of Petrology (47) 883-900
The volume %, distribution, texture and composition of coexisting olivine, Cr-spinel and glass has been determined in quenched lava samples from Hawaii, Iceland and mid-oceanic ridges. The volume ratio of olivine to spinel varies from 60 to 2800 and samples with >0·02% spinel have a volume ratio of olivine to...
Typing mineral deposits using their associated rocks, grades and tonnages using a probabilistic neural network
D.A. Singer
2006, Mathematical Geology (38) 465-474
A probabilistic neural network is employed to classify 1610 mineral deposits into 18 types using tonnage, average Cu, Mo, Ag, Au, Zn, and Pb grades, and six generalized rock types. The purpose is to examine whether neural networks might serve for integrating geoscience information available in large mineral databases to...
Associations between accelerated glacier mass wastage and increased summer temperature in coastal regions
M. Dyurgerov, G.J. McCabe
2006, Arctic, Antarctic, and Alpine Research (38) 190-197
Low-elevation glaciers in coastal regions of Alaska, the Canadian Arctic, individual ice caps around the Greenland ice sheet, and the Patagonia Ice Fields have an aggregate glacier area of about 332 ?? 103 km 2 and account for approximately 42% of all the glacier area outside the Greenland and Antarctic...
Subsurface imaging of an abandoned solid waste landfill site in Norman, Oklahoma
J.T. Zume, A. Tarhule, S. Christenson
2006, Ground Water Monitoring and Remediation (26) 62-69
Leachate plume emanating from an old unlined municipal landfill site near the city of Norman, Oklahoma, is discharging into the underlying alluvial aquifer. Subsurface imaging techniques, electrical resistivity tomography and electrical conductivity (EC) logging, were used on the site to detect and map the position of...
U-Pb SHRIMP dating of uraniferous opals
A.A. Nemchin, L.A. Neymark, S.L. Simons
2006, Chemical Geology (227) 113-132
U-Pb and U-series analyses of four U-rich opal samples using sensitive high-resolution ion microprobe (SHRIMP) demonstrate the potential of this technique for the dating of opals with ages ranging from several tens of thousand years to millions of years. The major advantages of the technique, compared to the conventional thermal...
Water and solute mass balance of five small, relatively undisturbed watersheds in the U.S.
N.E. Peters, J. B. Shanley, Brent T. Aulenbach, R. M. Webb, K. Campbell, R. Hunt, M. C. Larsen, R.F. Stallard, J. Troester, J.F. Walker
2006, Science of the Total Environment (358) 221-242
Geochemical mass balances were computed for water years 1992-1997 (October 1991 through September 1997) for the five watersheds of the U.S. Geological Survey Water, Energy, and Biogeochemical Budgets (WEBB) Program to determine the primary regional controls on yields of the major dissolved inorganic solutes. The sites, which vary markedly with...
A method for mapping corn using the US Geological Survey 1992 National Land Cover Dataset
S.K. Maxwell, J.R. Nuckols, M.H. Ward
2006, Computers and Electronics in Agriculture (51) 54-65
Long-term exposure to elevated nitrate levels in community drinking water supplies has been associated with an elevated risk of several cancers including non-Hodgkin's lymphoma, colon cancer, and bladder cancer. To estimate human exposure to nitrate, specific crop type information is needed as fertilizer application rates vary widely by crop type....
Relationships among condition indices, feeding and growth of walleye in Lake Erie
K.J. Hartman, F.J. Margraf
2006, Fisheries Management and Ecology (13) 121-130
Condition indices are often used as surrogates of fish health, growth, and feeding and to compare ecological well-being among fish populations. In an effort to identify easily measured indices, growth and food consumption were compared with gonadal-somatic index, liver-somatic index (LSI), fat-somatic index and relative weight (Wr) for ages 1-3...
Response of surface water chemistry to reduced levels of acid precipitation: Comparison of trends in two regions of New York, USA
Douglas A. Burns, M.R. McHale, C. T. Driscoll, K. M. Roy
2006, Hydrological Processes (20) 1611-1627
In light of recent reductions in sulphur (S) and nitrogen (N) emissions mandated by Title IV of the Clean Air Act Amendments of 1990, temporal trends and trend coherence in precipitation (1984-2001 and 1992-2001) and surface water chemistry (1992-2001) were determined in two of the most acid-sensitive regions of North...
