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Conference Papers

Browse almost 5,000 conference papers authored by our scientists and refine search by topic, location, year, and advanced search.

Filter Total Items: 5321

Effectiveness of the addition of alkaline materials at surface coal mines in preventing or abating acid mine drainage--Part 1. Geochemical considerations

The addition of alkaline materials to supplement deficient "neutralization potential" (NP) of mine spoil, and thus to prevent or abate acid mine drainage, has riot been successful at most surface coal mines in Pennsylvania. A basic problem may have been improper accounting for acid‐production potential and thus inadequate addition rates of calcium carbonate (CaCO3 ), calcium oxide (CaO) , or calci
Authors
Charles A. Cravotta, Keith Brady, Michael W. Smith, Richard L. Beam

Effectiveness of the addition of alkaline materials at surface coal mines in preventing or abating acid mine drainage--Part 2. Mine site case studies

The effectiveness of preventing or ameliorating acid mine drainage (AMD) through the application of alkaline additives is evaluated for eight surface coal mines in Pennsylvania. Many of the mine sites had overburden characteristics that made prediction of post‐mining water quality uncertain. Alkaline materials were applied at rates ranging from 42 to greater than 1,000 tons as calcium carbonate pe
Authors
Keith Brady, Michael W. Smith, Richard L. Beam, Charles A. Cravotta

Methods of measurement of exploratory well impacts, offshore Florida

Six offshore oil well tests were drilled off Key West in the late 1950s and early 1960s. Two wells were drilled on coral bottom, two on carbonate sand, and two on mixed turtle grass and gorgonian/sponge hardbottom. After locating the sites with a proton magnetometer; several underwater assessment methods were used to measure the ecological impacts of drilling. Because of differing environments and
Authors
Phillip A. Dustan, Jack L. Kindinger, B. H. Lidz, J.H. Hudson

Offshore and onshore sediment resource delineation and usage for coastal erosion control in Louisiana: The Isles Dernieres and Plaquemines barrier systems

No abstract available.
Authors
S. Penland, J. Mossa, R.A. McBride, K. Ramsey, J.R. Suter, C.G. Groat, S.J. Williamson

Reevaluation of large-scale dispersivities for a waste chloride plume: Effects of transient flow

This paper investigates the effects of transient groundwater flow on dispersion of a waste chloride plume in the basaltic aquifer beneath the Idaho (USA) National Engineering Laboratory. In an early application of numerical modeling techniques to the two-dimensional simulation of field-scale plumes, previous investigators identified longitudinal and transverse dispersivities using an independently
Authors
Daniel J. Goode, Leonard F. Konikow

Selected geographic analysis projects: U. S. Fish and Wildlife Service's National Wetlands Research Center

No abstract available.
Authors
Floyd O. Stayner, James D. Scurry, James B. Johnston, Mary C. Watzin, Pasquale F. Roscigno

The New Ireland Basin; a frontier basin in Papua New Guinea

No abstract available.
Authors
N.F. Exon, Michael S. Marlow

Development of an aquifer management model AQMAN3D

A computer code that enables the use of the USGS Modular groundwater flow model for aquifermanagement modeling has been developed. Aquifermanagement techniques integrate groundwater flow modeling with linear quadratic optimization methods for the solution of various aquifer management problems. The model AQMAN3D, is a modified version of a previously developed two-dimensional AQMAN model. The idea
Authors
Juan Carlos Puig, L. I. Rolon-Collazo, Ishmael Pagan-Trinidad

Landslide processes in saprolitic soils of a tropical rain forest, Puerto Rico

Shallow soil slips, earth and debris slides appear to be a primary mechanism of hillslope denudation in the rainforest of eastern Puerto Rico. Annual rainfall in excess of 4,000 mm, and thick sequences (up to 20 m) of residual soils (saprolite) combine to produce these landslides. Shear strength testing and observatons of tension cracks indicate that landslides may start as tensile failure of sapr
Authors
Matthew C. Larsen, Andrew Simon

Rainfall-soil moisture relations in landslide-prone areas of a tropical rain forest, Puerto Rico

Soil moisture conditions are not well documented in steep, tropical landslide-prone terrain. In the 11,330 ha Caribbean National Forest (CNF) in northeastern Puerto Rico more than 170 landslides that occurred from one to approximately 60 years ago have been mapped. Most of these landslides are shallow, with failure depths of 0.5 ot 7 m, and are associated with periods of intense, prolonged rainfal
Authors
Matthew C. Larsen, Angel J. Torres-Sanchez