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Articles 8941 - 8970 of 9279

Full-Text Articles in Earth Sciences

Consumption, Utilization And Modification Of Nutritional Resources By The Jackrabbit (Lepus Californicus) In The Mohave Desert, V.H. Shoemaker, K.A. Nagy, W.R. Costa Jan 1973

Consumption, Utilization And Modification Of Nutritional Resources By The Jackrabbit (Lepus Californicus) In The Mohave Desert, V.H. Shoemaker, K.A. Nagy, W.R. Costa

Memorandum

No abstract provided.


Chronic Toxicity Of A Copper, Cadmium And Zinc Mixture To The Fathead Minnow (Pimephales Promelas Rafinesque), John G. Eaton Jan 1973

Chronic Toxicity Of A Copper, Cadmium And Zinc Mixture To The Fathead Minnow (Pimephales Promelas Rafinesque), John G. Eaton

United States Environmental Protection Agency: Publications

Fathead minnows were exposed to a series or concentrations of a copper, cadmium and zinc mixture during a 12.5 month chronic test in water of 200 mg 1-1 total hardness. The metal concentrations in the mixture were selected on the basis of results obtained during previous chronic exposures to each of the metals individually in the same water. Strict summation of the chronic toxicities of the metals was not indicated when they were tested in combination. Toxic effects of the mixture attributable to copper appeared to be increased, but that attributable to cadmium was reduced. The effects thought to …


Captan Toxicity To Fathead Minnows (Pimephales Promelas), Bluegills (Lepomis Macrochirus), And Brook Trout (Salvelinus Fontinalis), Roger O. Hermanutz, Leonard H. Mueller, Kenneth D. Kempfert Jan 1973

Captan Toxicity To Fathead Minnows (Pimephales Promelas), Bluegills (Lepomis Macrochirus), And Brook Trout (Salvelinus Fontinalis), Roger O. Hermanutz, Leonard H. Mueller, Kenneth D. Kempfert

United States Environmental Protection Agency: Publications

The toxic effects of capt an on survival, growth, and reproduction of fathead minnows (Pimephales promelas) and on survival of bluegiIIs (Lepomis macrochirus) and brook trout (Salvelinus fontinalis) were determined in a flow-through system. In a 45-week exposure of fathead minnows, survival and growth were adversely affected at 39.5 μLg/Iiter. Adverse effects on spawning were suspected but not statisticaIly demonstrated at 39.5 and 16.5 μLg/Iiter. The maximum acceptable toxicant concentration (MATC), based on survival and growth, lies between 39.5 and 16.5 μLg/liter. The lethal threshold concentration (LTC) derived from acute exposures was 64 μLg/liter, …


Chronic Effect Of Low Ph On Fathead Minnow Survival, Growth And Reproduction, Donald I. Mount Jan 1973

Chronic Effect Of Low Ph On Fathead Minnow Survival, Growth And Reproduction, Donald I. Mount

United States Environmental Protection Agency: Publications

Fathead minnows (Pimephales promelas Rafinesque) were continuously exposed to reduced pH levels of 4.5, 5.2, 5.9, 6.6 and 7.5 (control) during a 13-month, one-generation test. Survival was not affected, even at the lowest pH tested. Fish behavior was abnormal, and fish were deformed at pH 4.5 and 5.2. Egg production and egg hatchability were reduced at pH 5.9 and lower, and all eggs were abnormal. A pH of 6.6 was marginal for vital life functions, but safe for continuous exposure. Free carbon dioxide, liberated by the addition of sulfuric acid to reduce the pH, may have had an unknown …


The Soil Conservation Service : Its Basis Of Co-Operation With Landowners, G W. Spencer, J. E. Watson Jan 1973

The Soil Conservation Service : Its Basis Of Co-Operation With Landowners, G W. Spencer, J. E. Watson

Journal of the Department of Agriculture, Western Australia, Series 4

The Soil Conservation Act of 1945 set up within the Department of Agriculture a Soil Conservation Service under the control of a Commissioner of Soil Conservation.

The Service aims to promote types of land use which will conserve the soil and prevent or overcome soil erosion. It also aims to educate landholders and the public generally in the aims and practice of soil conservation.

This article relates mainly to farm land activities, and in particular the co-operation of the Service with individual primary producer landholders for the prevention and control of erosion on their land.


Geophysical Institute Annual Report 1972-73, Geophysical Institute Jan 1973

Geophysical Institute Annual Report 1972-73, Geophysical Institute

GI Reports

The 1972-73 Geophysical Institute Annual Report presents an overview of the year’s scientific research achievements across the Institute’s disciplines, alongside operational summaries covering finances, administrative changes, and other key activities.


Regional Hydrothermal Alteration Of The Leadville Limestone (Mississippian) Of Central Colorado, L. V. Benson Jan 1973

Regional Hydrothermal Alteration Of The Leadville Limestone (Mississippian) Of Central Colorado, L. V. Benson

United States Geological Survey: Staff Publications

Massive metallic-sulfide deposits were implaced in the Leadville Limestone {Mississippian) of Central Colorado less than 70 million years ago. The thermal fluids which precipitated ore at Gilman, Colorado have regionally altered the Leadville Limestone. The sequence of alteration began with the recrystallization of limestone to a dark medium~grained dolomite containing a homogeneous distribution of Fe. This Was followed by partial recrystallization of the medium-grained dolomite to coarse-clear dolomite which contains an inhomogeneous distribution of Fe. The resulting banded rock is known as "zebra rock" . Precipitation of Si0 2 (jasperoid) occurred next. The jaspe=oid formed prior to the deposition of …


Characterization Of Water Movement Into And Through Soils During And Immediately After Rainstorms, C. T. Haan Dec 1972

Characterization Of Water Movement Into And Through Soils During And Immediately After Rainstorms, C. T. Haan

KWRRI Research Reports

The movement of water into and through soils in the unsaturated state is basic to many water resources problems including rainfall-runoff models, ground water recharge, irrigation, drainage, evapotranspiration and the movement of pollutants in soils. This study was conducted in an effort to determine if the flow equation based on Darcy's Law and the continuity equation could be used to describe watershed infiltration and thus be incorporated into hydrologic models.

The results of the study indicate that even on apparently uniform soils there is a great deal of variability in soil water properties. Handling this variability plus the difficulty of …


D.O. And Other Tests, Walter A. Lawrance Oct 1972

D.O. And Other Tests, Walter A. Lawrance

Walter Lawrance Papers

No abstract provided.


Mill Pollution, Walter A. Lawrance Oct 1972

Mill Pollution, Walter A. Lawrance

Walter Lawrance Papers

No abstract provided.


Press Reports, Walter A. Lawrance Oct 1972

Press Reports, Walter A. Lawrance

Walter Lawrance Papers

No abstract provided.


Pool Studies, Walter A. Lawrance Oct 1972

Pool Studies, Walter A. Lawrance

Walter Lawrance Papers

No abstract provided.


L.A. General Data, Walter A. Lawrance Oct 1972

L.A. General Data, Walter A. Lawrance

Walter Lawrance Papers

No abstract provided.


Computer Sheets, Walter A. Lawrance Oct 1972

Computer Sheets, Walter A. Lawrance

Walter Lawrance Papers

No abstract provided.


Special Reports, Walter A. Lawrance Oct 1972

Special Reports, Walter A. Lawrance

Walter Lawrance Papers

No abstract provided.


Bulletin No 3867 - Water For Agriculture. Clearing Cloudy Or Coloured Water, N. E. Platell Oct 1972

Bulletin No 3867 - Water For Agriculture. Clearing Cloudy Or Coloured Water, N. E. Platell

Bulletins - 3000 - 3999

THE suspended material in most water supplies is generally clay, although sometimes organic matter and materials precipitated from solution, such as hydrated iron oxides, may be present. Coloured waters are those waters that are still coloured, due to dissolved coloured matter, after suspended material has been removed. Some coloured waters such as those found in swampy areas may be entirely free of suspended material.

The amount of clay or colour present is mainly of concern where the water is used for household purposes. Only rarely is the clay or colour present in such quantities that the water is undrinkable for …


The Relation Between Soil Characteristics, Water Movement And Nitrate Contamination Of Ground Water, Grant W. Thomas, Matthew Mcmahon Sep 1972

The Relation Between Soil Characteristics, Water Movement And Nitrate Contamination Of Ground Water, Grant W. Thomas, Matthew Mcmahon

KWRRI Research Reports

Soils from several areas in Kentucky were placed in columns and leached with Ca(NO3)2. Subsoils high in iron oxide were found to retard the leaching of nitrate very significantly. In other soils, the nitrate moved through as fast as or slightly faster than the water.

Field application of nitrogen to corn was most efficient when done in the spring or summer near the time that the corn takes it up. The one exception to this was a red soil, where fall application of nitrogen resulted in little loss due to the retarding effect mentioned in the …


The Geology Of The Pittsburg Landing Area, Snake River Canyon, Oregon-Idaho, David L. White Aug 1972

The Geology Of The Pittsburg Landing Area, Snake River Canyon, Oregon-Idaho, David L. White

All-Inclusive List of Electronic Theses and Dissertations

The major purpose of the study was to map, describe, and correlate the pre-Tertiary rocks. Accessible and excellent exposures at Pittsburg Landing enabled the writer to make a somewhat detailed study of the stratigraphy. The thesis area also offered an opportunity to study in a reconnaissance manner, the Tertiary Columbia River Basalt as described by Waters, and more recently y Ozier.


Location Of Solution Channels And Sinkholes At Dam Sites And Backwater Areas By Seismic Methods: Part Ii, Vincent P. Drnevich, D. Raghu Aug 1972

Location Of Solution Channels And Sinkholes At Dam Sites And Backwater Areas By Seismic Methods: Part Ii, Vincent P. Drnevich, D. Raghu

KWRRI Research Reports

Four seismic field methods and a laboratory method are used to determine shear wave propagation velocities and shear moduli for two sites. The four seismic methods are: standard seismic refraction survey, down hole shooting refraction survey, transient Rayleigh wave survey, and crosshole shooting survey. A torsional resonant column apparatus was used for the laboratory tests. The cross hole shooting method gave the best results because direct measurements were made. Criteria for using this method are given. Methods which measure compression wave velocity give inconsistent results because the conversion to shear wave velocity is very sensitive to Poisson's ratio. Laboratory tests …


Location Of Solution Channels And Sinkholes At Dam Sites And Backwater Areas By Seismic Methods: Part I, Vincent P. Drnevich, S. R. Smith, E. P. Cleveland Aug 1972

Location Of Solution Channels And Sinkholes At Dam Sites And Backwater Areas By Seismic Methods: Part I, Vincent P. Drnevich, S. R. Smith, E. P. Cleveland

KWRRI Research Reports

The basic concepts associated with the sledge hammer seismic refraction survey are reviewed and a modified version called down hole shooting is discussed. The latter method has distinct advantages for rock surface profiling. These include: calibration at the end points of the survey, measurement of vertical wave propagation velocities directly, and having a refracted wave ray path for almost the entire survey length.

The down hole shooting seismic refraction survey has been simulated with the digital computer. The method can handle any shaped rock surface profile and generates corresponding travel time curves for the forward and reverse profile surveys. This …


Hydraulic And Sediment Transport Studies In Relation To River Sediment Control And Solid Waste Pollution And Economic Use Of The By-Products, Bruce R. Moore, Michael R. Short Jul 1972

Hydraulic And Sediment Transport Studies In Relation To River Sediment Control And Solid Waste Pollution And Economic Use Of The By-Products, Bruce R. Moore, Michael R. Short

KWRRI Research Reports

The distribution of sediments and conditions of transport were studied in the Kentucky, Big Sandy and Ohio Rivers. The sand and coal were in transport at different flow velocities for the rivers and the deposition of these sediments was a direct function of the flow conditions at a particular locality.

The flow conditions of transport of the sediments were studied in flumes as were the hydraulic conditions in model dredge holes to determine the feasibility of trapping sediment. The conditions of scour and fill were also established and compared with known conditions in a dredge hole in the Ohio River. …


Saltmarsh Ecology And Resource Protection, Gerard Desire Blais Jr. May 1972

Saltmarsh Ecology And Resource Protection, Gerard Desire Blais Jr.

Marine Affairs Theses and Major Papers

A panoramic lack of conservation education has produced a populace largely unaware of the value of marshland resources or measures for their protection. In a relentless era of ecological abuse, wetlands and salt marshes rank with endangered animal species in the quantitative loss culminating in extinction. Challenged continually by the relentless sea and exploited by unsound attempts at development, management, or even conservation, the efficiency of the marshlands is decreasing with each successive invasion. There is a demonstrated reduction in biological productivity, flood control, and water quality in areas where dredging, draining, and filling of marshes has taken place.


Effect Of Early Growth Cultivation On Beans And Sweet Corn, Raymond L. Cartee May 1972

Effect Of Early Growth Cultivation On Beans And Sweet Corn, Raymond L. Cartee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Investigations involving four cultivation treatments were conducted at the Utah State University Greenville Experimental Farm to determine the effect of these treatments on yields of beans and sweet corn. The effects of the different treatments on soil water content, soil temperature, and weed control in beans and corn were investigated. The effect of cultivation on the degree of root rot infection and the effect of different planting dates were also investigated in the bean study.

The pre-emergence treatment (ridged just before the plants emerge) produced a 48 percent greater bean yield and a 40 percent greater corn yield than the …


Methodological And Validation Study Of Seed Reserves In Desert Soils, David W. Goodall, Stuart Childs, Herman Wiebe Apr 1972

Methodological And Validation Study Of Seed Reserves In Desert Soils, David W. Goodall, Stuart Childs, Herman Wiebe

Memorandum

The development of a method for separating seeds from desert soils, and enumerating them, is described.

In the Great Basin desert, species differed greatly in their depth distribution, some having a peak at or just below the surface, while others were still abundant below 5 cm. Much higher seed densities were found beneath the canopies of shrubs and of tussock grasses than in the inter-spaces; no consistent differences were found, however, associated with the species of the canopy plant, or with distance from its center.

Tentative estimates are given of the seed population in the four validation sites in Curlew …


Digital Computer Modeling Of Limestone Groundwater Systems, John Thrailkill, David P. Beiter Apr 1972

Digital Computer Modeling Of Limestone Groundwater Systems, John Thrailkill, David P. Beiter

KWRRI Research Reports

Because limestone groundwater flows mainly In discrete openings, limestone aquifers are fundamentally different from aquifers In granular rocks. A digital computer program which simulates flow in a limestone aquifer as a pipe network was written and compared with the Sinkhole Plain aquifer of west-central Kentucky.

A reasonably good fit between observed parameters of the aquifer and those calculated were obtained under assumed conditions of both laminar and turbulent now In the aquifer. The Indicated gross permeablllty of the aquifer is 5600 melnzers with an assumed aquifer thickness of 100 feet. The location and discharge of springs along the streams bounding …


Eutrophication Factors In North Central Florida Lakes, H. D. Putnam, Patrick L. Brezonik, Earl E. Shannon Feb 1972

Eutrophication Factors In North Central Florida Lakes, H. D. Putnam, Patrick L. Brezonik, Earl E. Shannon

United States Environmental Protection Agency: Publications

A small Florida lake has been receiving a regimen of nutrient addition equivalent to 500 mg/m3-yr N and 43 mg/m3-yr P since 1967. Data has been accumulated through 1969. The effect on the lacustrine ecosystem of various biogenes includes production by primary producers, species diversity of plankton and certain production estimates at the secondary trophic level using natural populations of planktivorous fish. Plankton production using isotopic carbon is ca. 58 grms/m2-yr; Species diversity is slowly changing to a mixed chlorophycean and yellow-green. Biomass of benthic green filamentous types has increased slightly. Nutrient addition has …


Standing Crop And Productivity Of Marsh Vegetation At Saratoga Springs, California, W. G. Bradley Jan 1972

Standing Crop And Productivity Of Marsh Vegetation At Saratoga Springs, California, W. G. Bradley

Memorandum

No abstract provided.


Application Of Remote Sensing Techniques For Analysis Of Desert Biome Validation Studies, Paul T. Tueller, Garwin Lorain Jan 1972

Application Of Remote Sensing Techniques For Analysis Of Desert Biome Validation Studies, Paul T. Tueller, Garwin Lorain

Memorandum

No abstract provided.


Seasonal Use Of Soil Moisture By Mature Velvet Mesquite, Dwight R. Cable Jan 1972

Seasonal Use Of Soil Moisture By Mature Velvet Mesquite, Dwight R. Cable

Memorandum

No abstract provided.


Ingestion Rates, Live Weight Caloric Densities And Standing Crop Estimates For Desert Biome Rodents, R. K. Schreiber, D. R. Johnson Jan 1972

Ingestion Rates, Live Weight Caloric Densities And Standing Crop Estimates For Desert Biome Rodents, R. K. Schreiber, D. R. Johnson

Memorandum

No abstract provided.