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Page 1412, results 35276 - 35300

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Not all publications have extents, not all extents are completely accurate
Gas transfer within a multi-stage packed column oxygen absorber: Model development and application
Barnaby J. Watten, Claude E. Boyd
1990, Aquacultural Engineering (9) 33-59
A packed column oxygen obsorber was developed in which oxygen flow is directed, in serial reuse, through parallel packed column stages receiving equal portions of the liquid being treated. The relative performance of the absorber was established using a computer simulation program employing finite difference-mass transfer calculations. The program was...
Changes in Wisconsin's Lake Michigan salmonid sport fishery, 1969-1985
Michael J. Hansen, Paul T. Schultz, Becky A. Lasee
1990, North American Journal of Fisheries Management (10) 442-457
The modern sport fishery for salmonids in Wisconsin waters of Lake Michigan was begun during 1963-1969 with the stocking of rainbow trout (Oncorhynchus mykiss), lake trout (Salvelinus namaycush), brook trout (S. fontinalis), brown trout (Salmo trutta), coho salmon (O. kisutch), and chinook salmon (O. tshawytscha). The fishery grew rapidly...
H, O, Sr, Nd, and Pb isotope geochemistry of the Latir volcanic field and cogenetic intrusions, New Mexico, and relations between evolution of a continental magmatic center and modifications of the lithosphere
C.M. Johnson, P. W. Lipman, G.K. Czamanske
1990, Contributions to Mineralogy and Petrology (104) 99-124
Over 200 H, O, Sr, Nd, and Pb isotope analyses, in addition to geologic and petrologic constraints, document the magmatic evolution of the 28.5-19 Ma Latir volcanic field and associated intrusive rocks, which includes multiple stages of crustal assimilation, magma mixing, protracted crystallization, and open- and closed-system evolution in the...
Modeling the effects of serial off-gas reuse on the performance of a hooded surface oxygen obsorption system
Barnaby J. Watten, J. W. Meade, Claude E. Boyd
1990, Aquacultural Engineering (9) 97-120
A numerical model was used to evaluate the performance of a surface agitation system designed to contact commercial oxygen with water. The modeled system was unique in that oxygen-rich off-gas, normally discharged to the atmosphere, was directed in serial reuse through additional contact stages receiving untreated water. A correlation between...
Earthquakes, January-February 1990
W. J. Person
1990, Earthquakes & Volcanoes (USGS) (22) 179-182
There were no major earthquakes during the first 2 months of the year and there were no earthquake-related deaths reported during this same time period. In the United States a moderate earthquake on February 28 in southern California caused some minor injuries and considerable damage. ...
Volcano hazard mitigation program in Indonesia
A. Sudradjat
1990, Earthquakes & Volcanoes (USGS) (22) 227-229
Volcanological investigations in Indonesia were started in the 18th century, when Valentijn in 1726 prepared a chronological report of the eruption of Banda Api volcno, Maluku. Modern and intensive volcanological studies did not begin until the catastrophic eruption of Kelut volcano, East Java, in 1919. The eruption took 5,011 lives...
A new planktic foraminifer transfer function for estimating pliocene-Holocene paleoceanographic conditions in the North Atlantic
H.J. Dowsett, R.Z. Poore
1990, Marine Micropaleontology (16) 1-23
A new planktic foraminifer transfer function (GSF18) related 5 North Atlantic assemblages to winter and summer sea surface temperature. GSF18, based on recombined and simplified core top census data, preserves most environmental information and reproduces modern North Atlantic conditions with approximately the same accuracy as previous transfer functions, but can...
Relative efficiency of four parameter-estimation methods in steady-state and transient ground-water flow models
M. C. Hill
Gambolati G.Rinaldo A.Brebbia C.A.Gray W.G.Pinder G.F., editor(s)
1990, Conference Paper, Computational Methods in Subsurface Hydrology
Parameters in numerical ground-water flow models have been successfully estimated using nonlinear-optimization methods such as the modified Gauss-Newton (GN) method and conjugate-direction methods. This paper investigates the relative efficiency of GN and three conjugate-direction parameter-estimation methods on two-dimensional, steady-state and transient ground-water flow test cases. The steady-state test cases are...
The geology of selected peat-forming environments in temperate and tropical latitudes
C. C. Cameron, C.A. Palmer, J.S. Esterle
1990, International Journal of Coal Geology (16) 127-130
We studied peat in several geologic and climatic settings: (1) a glaciated terrain in cold-temperate Maine and Minnesota, U.S.A.; (2) an island in a temperate maritime climate in the Atlantic Ocean off the coast of Maine, U.S.A., where sea level is...
Horizontal density-gradient effects on simulation of flow and transport in the Potomac Estuary
Raymond W. Schaffranek, Robert A. Baltzer
Chang Howard H.Hill Joseph C., editor(s)
1990, Conference Paper, Hydraulic Engineering - Proceedings of the 1990 National Conference
A two-dimensional, depth-integrated, hydrodynamic/transport model of the Potomac Estuary between Indian Head and Morgantown, Md., has been extended to include treatment of baroclinic forcing due to horizontal density gradients. The finite-difference model numerically integrates equations of mass and momentum conservation in conjunction with a transport equation for heat, salt, and...
Controls on porphyrin concentrations of Pennsylvanian organic-rich shales, Western U.S.A.
J.L. Clayton, G.E. Michael
1990, Energy & Fuels (4) 644-646
Organic-rich black shales of Middle Pennsylvanian (Desmoinesian) age occur over much of the central U.S. and as far west as the northern Denver and southeastern Powder River basins. Total organic carbon contents (Corg) are commonly greater than 10 wt %. Porphyrin concentrations (vanadyl + nickel) are as high as 40000...
Radium distribution and indoor radon in the Pacific Northwest
J. S. Duval, J. K. Otton
1990, Geophysical Research Letters (17) 801-804
Aerial gamma-ray data were compiled to produce a map showing the distribution of radium (226Ra) in near-surface materials in the Pacific Northwest (Washington, Oregon, and Idaho, and parts of Montana, Wyoming, California, Nevada, and Utah). A comparison of measurements of indoor concentration levels of radon (222Rn)...
Geometry of the September 1971 eruptive fissure at Kilauea volcano, Hawaii
J.J. Dvorak
1990, Bulletin of Volcanology (52) 507-514
A three-dimensional model has been used to estimate the location and dimensions of the eruptive fissure for the 24-29 September 1971 eruption along the southwest rift zone of Kilauea volcano, Hawaii. The model is an inclined rectangular sheet embedded in an elastic half-space with constant displacement on the plane of...
Return to ranger submarine slide, Baja California, Mexico
W. R. Normark
1990, Geo-Marine Letters (10) 81-91
Ranger Slide is a modest (12 km3) slide deposit of Pliocene and younger sediment on the continental slope in northern Sebastian Vizcaino Bay, Mexico. A limited survey using a deeply-towed instrument shows that hummocky terrain immediately downslope from the slide scar consists of large blocks of semiconsolidated sediment, some exceeding...
Instantaneous and daily values of the surface energy balance over agricultural fields using remote sensing and a reference field in an arid environment
William P. Kustas, M. S. Moran, R. D. Jackson, L. W. Gay, L.F.W. Duell, K. E. Kunkel, A.D. Matthias
1990, Remote Sensing of Environment (32) 125-141
Remotely sensed surface temperature and reflectance in the visible and near infrared wavebands along with ancilliary meteorological data provide the capability of computing three of the four surface energy balance components (i.e., net radiation, soil heat flux, and sensible heat flux) at different spatial and temporal scales. As a result,...
Crustal strain near the Big Bend of the San Andreas Fault: Analysis of the Los Padres-Tehachapi Trilateration Networks, California
D. Eberhart-Phillips, M. Lisowski, Mark D. Zoback
1990, Journal of Geophysical Research Solid Earth (95) 1139-1153
In the region of the Los Padres-Tehachapi geodetic network, the San Andreas fault (SAF) changes its orientation by over 30° from N40°W, close to that predicted by plate motion for a transform boundary, to N73°W. The strain orientation near the SAF is consistent with right-lateral shear along the fault, with...
Petrology, isotope characteristics, and K-Ar ages of the Maranhão, northern Brazil, Mesozoic basalt province
R.V. Fodor, A.N. Sial, S.B. Mukasa, E.H. McKee
1990, Contributions to Mineralogy and Petrology (104) 555-567
Northern Brazil contains remnants of Mesozoic flood basalts and hypabyssal rocks that were apparently emplaced during tectonism related to opening of the Atlantic Ocean. Analyses and new K-Ar ages reveal that this ∼700x250 km Maranhão province (5°–8°S) has low-Ti basalts (∼1.1 wt% TiO2) in the western part that range...
Reflected and mode-converted seismic waves within the shallow Aleutian subduction zone, southern Kenai Peninsula, Alaska
C.D. Stephens, R.A. Page, J.C. Lahr
1990, Journal of Geophysical Research Solid Earth (95) 6883-6897
Pronounced secondary phases observed in local recordings of quarry shots and earthquakes on the southern Kenai Peninsula, Alaska, are identified as reflected P and S and converted S-to-P phases originating within four depth ranges: in the upper few kilometers of the Cook Inlet Tertiary basin, at midcrustal depths within the...
Disseminated flake graphite and amorphous graphite deposit types. An analysis using grade and tonnage models
David M. Sutphin, James D. Bliss
1990, CIM Bulletin (83) 85-89
On the basis of differences derived from genetic, descriptive, and grade-tonnage data, graphite deposits are classified here into three deposit types: disseminated flake, amorphous (microcrystalline), or graphite veins. Descriptive models have been constructed for each of these deposit types, and grade-tonnage models are constructed for disseminated flake and amorphous deposit...
Rheological analysis of fine-grained natural debris-flow material
Jon J. Major, Thomas C. Pierson
French Richard H., editor(s)
1990, Conference Paper, Hydraulics/Hydrology of Arid Lands
Experiments were conducted on large samples of fine-grained material (???2mm) from a natural debris flow using a wide-gap concentric-cylinder viscometer. The rheological behavior of this material is compatible with a Bingham model at shear rates in excess of 5 sec. At lesser shear rates, rheological behavior of the material deviates...
Metal and nutrient behavior in the Raritan estuary, New Jersey, U.S.A.: The effect of multiple freshwater and industrial waste inputs
A.S. Maest, D.A. Crerar, R.F. Stallard, J. N. Ryan
1990, Chemical Geology (81) 133-149
A geochemical analysis of the Raritan estuary during high and low river flow is presented. Several statistical and graphical approaches, in addition to a hydrodynamic model of the Raritan estuary, are used to demonstrate the effects of lateral inputs on trace-element distribution in a complicated fluvial-marine system. Results from factor...
Thermal maturity of Jurassic shales from the Newark Basin, U.S.A.: Influence of hydrothermal fluids and implications to basin modeling
C.C. Walters, R. K. Kotra
1990, Applied Geochemistry (5) 211-225
Organic geochemical investigations were conducted on a series of cores that systematically sampled the uppermost Jurassic strata from the northern Newark Basin. Each sedimentary unit consists of fluvial red sandstones and siltstones with cyclic deposits of interbedded black lacustrine shales and...