Conference Papers
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Browse almost 5,000 conference papers authored by our scientists and refine search by topic, location, year, and advanced search.
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Climatic changes near the Great Lakes inferred from 141 year ice records Climatic changes near the Great Lakes inferred from 141 year ice records
Freeze-up and break-up dates and duration of ice cover for lakes and rivers represent an integration of weather conditions prior to the specified event(s). Changes in mean ice conditions may be used as quantitative indicators of climatic changes if long homogenous ice records are accompanied by sufficiently homogenous air temperature records to calibrate the changes in mean ice cover in...
Authors
Raymond A. Assel, Dale M. Robertson
Comparison of three newton-like nonlinear least-squares methods for estimating parameters of ground-water flow models Comparison of three newton-like nonlinear least-squares methods for estimating parameters of ground-water flow models
Three methods of solving nonlinear least-squares problems were compared for robustness and efficiency using a series of hypothetical and field problems. A modified Gauss-Newton/full Newton hybrid method (MGN/FN) and an analogous method for which part of the Hessian matrix was replaced by a quasi-Newton approximation (MGN/QN) solved some of the problems with appreciably fewer iterations...
Authors
R.L. Cooley, M. C. Hill
Computer simulation of dry layered granular flow down an incline composed of grains Computer simulation of dry layered granular flow down an incline composed of grains
Experiments show that gravity-driven dry granular flows are essentially layered for smooth spheres. This paper describes layer-to-layer interaction in the flow. Assuming two-dimensional flow and neglecting the interaction of grains within the same layer, one may idealize the problem as an elastic sphere under external forces moving down an incline within a layer of identical spheres...
Authors
Chi-Hai Ling, Chyan-Deng Jan
D4Z: A new renumbering for iterative solution of ground-water flow and solute-transport equations D4Z: A new renumbering for iterative solution of ground-water flow and solute-transport equations
D4 zig-zag (D4Z) is a new renumbering scheme for producing a reduced matrix to be solved by an incomplete LU preconditioned, restarted conjugate-gradient iterative solver. By renumbering alternate diagonals in a zig-zag fashion, a very low sensitivity of convergence rate to renumbering direction is obtained. For two demonstration problems involving groundwater flow and solute transport...
Authors
K.L. Kipp, T.F. Russell, J.S. Otto
Data set for verification of 3-D free-surface hydrodynamic models, Carquinez Strait, California Data set for verification of 3-D free-surface hydrodynamic models, Carquinez Strait, California
No abstract available.
Authors
P. E. Smith, R.N. Oltmann, M.R. Simpson
Design and performance of a horizontal, axial-flow, water circulator Design and performance of a horizontal, axial-flow, water circulator
No abstract available at this time
Authors
R.D. Howerton, C.E. Boyd, B.J. Watten
Desk-top model buildings for dynamic earthquake response demonstrations Desk-top model buildings for dynamic earthquake response demonstrations
Models of buildings that illustrate dynamic resonance behavior when excited by hand are designed and built. Two types of buildings are considered, one with columns stronger than floors, the other with columns weaker than floors. Combinations and variations of these two types are possible. Floor masses and column stiffnesses are chosen in order that the frequency of the second mode is...
Authors
A. Gerald Brady
Development of ground-water vulnerability database for the U.S. Environmental protection agency's hazard ranking system using a geographic information system Development of ground-water vulnerability database for the U.S. Environmental protection agency's hazard ranking system using a geographic information system
Geographic information system (GIS) methods were applied to the U.S. Environmental Protection Agency's (EPA) hazard ranking system (HRS) to evaluate the vulnerability of ground water to contamination from actual or potential releases of hazardous materials from waste-disposal sites. Computerized maps of four factors influencing ground-water vulnerability - hydraulic conductivity...
Authors
John S. Clarke, Jerry W. Sorensen, Henry G. Strickland, George Collins
Development of spatial data guidelines and standards: spatial data set documentation to support hydrologic analysis in the U.S. Geological Survey Development of spatial data guidelines and standards: spatial data set documentation to support hydrologic analysis in the U.S. Geological Survey
Spatial data analysis has become an integral component in many surface and sub-surface hydrologic investigations within the U.S. Geological Survey (USGS). Currently, one of the largest costs in applying spatial data analysis is the cost of developing the needed spatial data. Therefore, guidelines and standards are required for the development of spatial data in order to allow for data...
Authors
James L. Fulton
Diel feeding ecology of the fish community on the Juniata River, Pennsylvania Diel feeding ecology of the fish community on the Juniata River, Pennsylvania
No abstract available at this time
Authors
D. S. Dropkin, J. H. Johnson
Disappearing coastal wetlands Disappearing coastal wetlands
No abstract available.
Authors
James B. Johnston, Donald W. Field, Anthony J. Reyer
Effects of acidic deposition on the erosion of carbonate stone - experimental results from the U.S. National Acid Precipitation Assessment Program (NAPAP) Effects of acidic deposition on the erosion of carbonate stone - experimental results from the U.S. National Acid Precipitation Assessment Program (NAPAP)
One of the goals of NAPAP-sponsored research on the effects of acidic deposition on carbonate stone has been to quantify the incremental effects of wet and dry deposition of hydrogen ion, sulfur dioxide and nitrogen oxides on stone erosion. Test briquettes and slabs of freshly quarried Indiana limestone and Vermont marble have been exposed to ambient environmental conditions in a long...
Authors
P. A. Baedecker, M.M. Reddy, K.J. Reimann, C.A. Sciammarella