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Page 2181, results 54501 - 54525

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Not all publications have extents, not all extents are completely accurate
Vulnerability of young lake trout to predation after chronic exposure to PCB's and DDE
Michael J. Mac
1981, Book chapter, Chlorinated hydrocarbons as a factor in the reproduction and survival of lake trout (Salvelinus namaycush) in Lake Michigan
The vulnerability of fry of Lake Michigan lake trout (Salvelinus namaycush) to predation by rainbow trout (Salmo gairdneri) was tested after the fry had been exposed to PCB's, DDE, and a combination of these contaminants in both water and food at concentrations corresponding to ambient levels (1X) in water and...
Growth and mortality of fry of Lake Michigan lake trout during chronic exposure to PCB's and DDE
William H. Berlin, Robert J. Hesselberg, Michael J. Mac
1981, Technical Paper 105
Fry hatched from eggs of Lake Michigan lake trout (Salvelinus namaycush) were exposed (beginning about 1 week after hatching) to contaminant concentrations of PCB's and DDE similar to those in water and plankton in southeastern Lake Michigan (1X level), and to concentrations about 5 (5X) and 25 (25X) times greater....
Temperature selection by young lake trout after chronic exposure to PCB's and DDE
Michael J. Mac, Roger A. Bergstedt
1981, Technical Paper 105
Temperature selection tests were conducted with fry of Lake Michigan lake trout (Salvelinus namaycush) exposed to PCB's, DDE and a combination of these contaminants in food and water at levels 25 times the ambient levels in plankton and water in Lake Michigan. The observed effect of the contaminants was...
Swimming performance of young lake trout after chronic exposure to PCBs and DDE
Donald V. Rottiers, Roger A. Bergstedt
1981, Technical Paper 105
Swimming performance was measured in fry of lake trout (Salvelinus namaycush) exposed to PCB's, DDE, and a combination of these two contaminants in both food and water at concentrations equal to, and 5 and 25 times higher than, levels found in Lake Michigan water and plankton. Fry were tested...
Potentiometric surface of the Wilcox-Carrizo aquifer; Bienville, Red River, and northern Natchitoches, and southern Webster Parishes, Louisiana
G.N. Ryals
1981, Open-File Report 80-1179
The potentiometric surface of the Wilcox-Carrizo aquifer in central northwestern Louisiana is shown by contours using data collected from 1960 to 1980. The aquifer is not affected by regional water-level declines as no large pumping centers have been developed. Seasonal water-level fluctuations in wells are generally less than 10 feet...
The origin of epigenetic graphite: Evidence from isotopes
P. L. Weis, I. Friedman, J.P. Gleason
1981, Geochimica et Cosmochimica Acta (45) 2325-2332
Stable carbon isotope ratios measured in syngenetic graphite, epigenetic graphite, and graphitic marble suggests that syngenetic graphite forms only by the metamorphism of carbonaceous detritus. Metamorphism of calcareous rocks with carbonaceous detritus is accompanied by an exchange of carbon between the two, which may result in large changes in isotopic...
Electrolytic oxidation of anthracite
F. E. Senftle, K.M. Patton, I. Heard Jr.
1981, Fuel (60) 1131-1136
An anthracite slurry can be oxidized only with difficulty by electrolytic methods in which aqueous electrolytes are used if the slurry is confined to the region of the anode by a porous pot or diaphragm. However, it can be easily oxidized if the anthracite itself is used as the anode....
Antipathetic magnesium-manganese relationship in basal metalliferous sediments
S. Bloch
1981, Chemical Geology (33) 101-113
Basal metalliferous sediments from sites 77B, 80 and 81 of the Deep Sea Drilling Project represent mixtures of pelagic clay, biogenic ooze, and a metalliferous component of hydrothermal origin. The metalliferous end-member of the sediments displays a strong inverse relationship (r = -0.88) between Mg and Mn. Mg is most...
Loss of nitrogenous dissolved organic matter from small lakes
Bruce A. Manny, Akira Otsuki
1981, Journal of Freshwater Ecology (1) 193-202
To determine how much organic nitrogen is lost from lakes during winter by natural processes, we collected water in fall and winter from six small lakes (area, 5-822 hectares) and separated organic matter dissolved in the water with n-butanol into three fractions--yellow organic acids, a white precipitate, and aqueous (nonextractable)...
Dissolution of salt on the east flank of the Permian Basin in the southwestern U.S.A.
K.S. Johnson
1981, Journal of Hydrology (54) 75-93
Hydrogeologic studies prove that natural dissolution of bedded salt occurs at shallow depths in many parts of the Permian Basin of the southwestern U.S.A. This is especially well-documented on the east side of the basin in study areas on the Cimarron River and Elm Fork in western Oklahoma, and on...
Role of solute-transport models in the analysis of groundwater salinity problems in agricultural areas
Leonard F. Konikow
1981, Agricultural Water Management (4) 187-205
Undesirable salinity increases occur in both groundwater and surface water and are commonly related to agricultural practices. Groundwater recharge from precipitation or irrigation will transport and disperse residual salts concentrated by evapotranspiration, salts leached from soil and aquifer materials, as well as some dissolved fertilizers and pesticides. Where stream salinity...
Electrical properties of granite with implications for the lower crust
G.R. Olhoeft
1981, Journal of Geophysical Research Solid Earth (86) 931-936
The electrical properties of granite appear to be dominantly controlled by the amount of free water in the granite and by temperature. Minor contributions to the electrical properties are provided by hydrostatic and lithostatic pressure, structurally bound water, oxygen fugacity, and other parameters. The effect of sulfur fugacity may be...
Sedimentary framework of the Potomac River estuary, Maryland
Harley J. Knebel, E. Ann Martin, J.L. Glenn, Sally W. Needell
1981, Geological Society of America Bulletin (92) 578-589
Analyses of seismic-reflection profiles, sediment cores, grab samples, and side-scan sonar records, along with previously collected borehole data, reveal the characteristics, distribution, and geologic history of the shallow strata beneath the Potomac River estuary. The lowermost strata are sediments of the Chesapeake Group (lower Miocene to lower Pleistocene) that crop...
Stable isotope systematics in mesozoic granites of Central and Northern California and Southwestern Oregon
U. Masi, J. R. O’Neil, R. W. Kistler
1981, Contributions to Mineralogy and Petrology (76) 116-126
18O, D, and H2O+ contents were measured for whole-rock specimens of granitoid rocks from 131 localitics in California and southwestern Oregon. With 41 new determinations in the Klamath Mountains and Sierra Nevada, initial strontium isotope ratios are known for 104 of these samples. Large variations in ??18O (5.5 to 12.4),...
Flow through fractures
C. E. Neuzil, James V. Tracy
1981, Water Resources Research (17) 191-199
Flow through fractures is often idealized as flow between two parallel plates (plane Poiseuille flow). The opening or aperture between parallel plates is unambiguous and its relation to flowrate is well known. However, fractures in rock have uneven walls and a variable aperture. A model for flow in a fracture...
Tertiary carbonate-dissolution cycles on the Sierra Leone Rise, eastern equatorial Atlantic Ocean
Walter E. Dean, James V. Gardner, P. Cepek
1981, Marine Geology (39) 81-101
Most of the Tertiary section on Sierra Leone Rise off northwest Africa consists of chalk, marl, and limestone that show cyclic alterations of clay-rich and clay-poor beds about 20–60 cm thick. On the basis of biostratigraphic accumulation rates, the cycles in Oligocene and Miocene chalk have periods which average about...
Introduction and summary: Chlorinated hydrocarbons as a factor in the reproduction and survival of lake trout (Salvelinus namaycush) in Lake Michigan
Wayne A. Willford, Roger A. Bergstedt, William H. Berlin, Neal R. Foster, Robert J. Hesselberg, Michael J. Mac, Dora R. May Passino, Robert E. Reinert, Donald V. Rottiers
1981, Book chapter, Chlorinated hydrocarbons as a factor in the reproduction and survival of lake trout (Salvelinus namaycush) in Lake Michigan
Although lake trout (Salvelinus namaycush) were considered extinct in Lake Michigan by the mid 1950's, control of the parasitic sea lamprey (Petromyzon marinus) and extensive restocking resulted in an abundance of hatchery-produced lake trout in the lake by the early 1970's. However, no naturally produced yearling or older lake trout...