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Articles 57091 - 57120 of 59364
Full-Text Articles in Entire DC Network
Saltmarsh Ecology And Resource Protection, Gerard Desire Blais Jr.
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.
The Microtine Rodents Of The Mullen Assemblage From The Pleistocene Of North Central Nebraska, Larry D. Martin
The Microtine Rodents Of The Mullen Assemblage From The Pleistocene Of North Central Nebraska, Larry D. Martin
Bulletin of the University of Nebraska State Museum (1924–2023)
The University of Nebraska State Museum has had an active collecting program in Hooker and Cherry counties, Nebraska, since the 1930's. The following University of Nebraska State Museum collecting localities have been extensively excavated: Cr-10, Cr-102, Cr-11, Ho-101, Ho-102, and Ho-103. These localities have produced a large vertebrate fauna described by Jakway as the Mullen Local Fauna which he considered for the most part to be Early lllinoian. Further study of this local fauna now demonstrates that assemblage does include Early as well as Middle Pleistocene animals. The purpose of this paper is to report on the evidence regarding the …
Use Of Groundwater For Irrigation In Clay County, Nebraska, 1970, Eugene K. Steele Jr.
Use Of Groundwater For Irrigation In Clay County, Nebraska, 1970, Eugene K. Steele Jr.
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Model For Estimating Soil Water Flow, Water Content, Evapotranspiration And Root Extraction, Musa N. Nimah
Model For Estimating Soil Water Flow, Water Content, Evapotranspiration And Root Extraction, Musa N. Nimah
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
A mathematical model was developed to predict water content profiles, evapotranspiration, water flow from or to the water table, root extraction and root water potential at the surface as functions of time under unsteady state conditions.
The model was tested in the field at The Hullinger Farm near Vernal, Utah, in 1970 and 1971. Comparison of water content-depth profiles show excellent agreement at the end of a 9- day run in 1970 on oats seeded to alfalfa. In 1971 with alfalfa as the crop, the data show best agreement, between predicted and computed water content-depth profiles, 48 hours after any …
An Examination Of The Inorganic Nitrogen Status Of A Soil Of The Alaskan Coastal Tundra Plain, Norton R. Munn
An Examination Of The Inorganic Nitrogen Status Of A Soil Of The Alaskan Coastal Tundra Plain, Norton R. Munn
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
This experiment was designed to measure in situ concentrations of NH4+ and NO3--N in a soil of the arctic coastal tundra plain, to determine if nitrification was taking place in this soil and to determine if the vascular plants growing in this soil could assimilate NH4+-N.
The extractable NH4+-N concentration was approximately 40 μg/g in the 01 horizon and 10 μg/g in the 02 horizon. The NO3--N concentration was approximately 5 μg/g in the 01 horizon and 4 μg/g in the 02 …
Groundwater Levels In Nebraska, 1971, C.F. Keech
Groundwater Levels In Nebraska, 1971, C.F. Keech
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Tertiary Igneous Rocks Of Northeastern Cache Valley, Idaho, Parry D. Willard
Tertiary Igneous Rocks Of Northeastern Cache Valley, Idaho, Parry D. Willard
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The tuffs and limestones of the Tertiary Salt Lake Formation in northeastern Cache Valley, Franklin County, Idaho, are intruded by basic and intermediate igneous dikes and sills. The Tertiary intrusives are exposed in an area 10 miles long and 2 miles wide between Bear River and Maple Creek in the foothills of the Bear River Range east of Preston, Idaho. They trend north-northwest. The intrusives are mostly diabase but include a small body of syenodiorite and several small andesite dikes. The intrusives seem to be emplaced along early Basin and Range faults. They are limited to the Cache Valley Member …
Geology Of The Wildcat Hills, Utah, Ronald C. Howes
Geology Of The Wildcat Hills, Utah, Ronald C. Howes
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The Wildcat Hills, located in Curlew Valley of northwestern Utah, are composed of a series of late Tertiary extrusive and dike rocks. Five volcanic rock types have been identified: an andesite, a rhyolite, a perlite, a basalt, and a welded tuff. Hydration of obsidian pellets contained in the flows has produced some of the perlite. Diatremes in the andesite attest to the high-volatile content and the explosive extrusion of some of the lavas. A compound basalt neck indicates that basalt was extruded at the Wildcat Hills and is not an erosional remnant of the basalt flow from the base of …
Stratigraphy And Environmental Analysis Of The Swan Peak Formation And Eureka Quartzite, Northern Utah, George Gregory Francis
Stratigraphy And Environmental Analysis Of The Swan Peak Formation And Eureka Quartzite, Northern Utah, George Gregory Francis
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The Swan Peak Formation in north-central Utah thickens westward, from zero feet near Logan to 687 feet in the Promontory Range. The unit is subdivided into three distinct members: 1) A lower member of interbedded shales, limestones, and quartzites; 2) A middle member of interbedded shales and brown quartzites; and 3) An upper member of white quartzites. The Swan Peak thins southward toward the east-west-trending Tooele Arch in the area of study; this thinning probably reflects both lesser deposition and greater subsequent erosion there than elsewhere. The lower member in northern Utah probably was deposited in shallow-shelf and/or traditional shoreface-shelf …
Some Physical Characteristics Of A Small Agricultural Watershed In East-Central Illinois, Ruth Laurence Davis
Some Physical Characteristics Of A Small Agricultural Watershed In East-Central Illinois, Ruth Laurence Davis
Senior Honors Papers / Undergraduate Theses
No abstract provided.
Model For Predicting Simultaneous Distribution Of Salt And Water In Soils, Satish C. Gupta
Model For Predicting Simultaneous Distribution Of Salt And Water In Soils, Satish C. Gupta
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Knowledge of water and salt movement in soils is necessary for development of a management scheme for controlling the quality of irrigation return flow. A computer model was developed to predict the distribution of water and salts in the root zone under varying initial and boundary conditions. The model consists of water flow and salt flow sub-models. The water flow sub-model considers the numerical approximation of the general water flow equation with modification for water loss by evapotranspiration (and thus root extraction). The salt flow sub-model considers the mass flow of salts, chemical exchange, precipitation or dissolution of CaCO3 …
Evaluation Of The Filter Paper Method For Estimating Soil Water Potential, Samir Al-Khafaf
Evaluation Of The Filter Paper Method For Estimating Soil Water Potential, Samir Al-Khafaf
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The filter paper method for measuring soil water potential was evaluated. The method was calibrated using salt solutions (-1.4 bars to -22.4 bars), sample chamber psychrometer (-1 to -50 bars), pressure plate (-0.1 to -15 bars) and soil column at equilibrium (0 to -0.2 bars). It was found that the absolute temperature had little effect on the predicted soil water potential, but a temperature variation had a large effect. It was found that the temperature fluctuation must be small. The predicted water potential was influenced by the type of contact of the soil with the filter paper. It is suggested …
Effect Of Early Growth Cultivation On Beans And Sweet Corn, Raymond L. Cartee
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 …
Potentiometric Titration Of Sulfate Using A Lead-Mercury Amalgam Indicator Electrode, Charles W. Robbins
Potentiometric Titration Of Sulfate Using A Lead-Mercury Amalgam Indicator Electrode, Charles W. Robbins
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
A lead sensitive indicator electrode was constructed with a 70 percent lead and 30 percent mercury amalgam billet. Sulfate concentrations in pure solutions, natural waters, and soil saturation extracts were determined potentiometrically using the lead-mercury amalgam indicator electrode and a standard calomel reference electrode. Sulfate concentrations over the range 0.4 to 20 milliequivalents sulfate per liter were determined with an automatic titrator and compared to a turbidimetric method for accuracy and precision. The values obtained by the two methods from twelve saturation extracts and three subsurface drainage waters were not significantly different and the potentiometric method was generally more precise. …
Petrology Of The Ordovician Swan Peak Formation, Southeastern Idaho And North-Central Utah, Warren J. Schulingkamp Ii
Petrology Of The Ordovician Swan Peak Formation, Southeastern Idaho And North-Central Utah, Warren J. Schulingkamp Ii
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The Swan Peak Formation in southeastern Idaho and north-central Utah is a sedimentary unit consisting of orthoquartzite, sandstone, siltite, shale, and limestone. The formation is divisible into three members, and the lower two members each are divisible into two informal lithologic subunits.
The lower member consists of a lower subunit of gray, calcareous sandy siltite composed of subangular to subrounded quartz grains cemented by quartz overgrowths, calcite, or iron oxide, and an upper subunit of black shale with minor interbedded silty quartzose sandstone and biomicrite (limestone).
The middle member consists of a lower subunit of interbedded pale green shale and …
Methodological And Validation Study Of Seed Reserves In Desert Soils, David W. Goodall, Stuart Childs, Herman Wiebe
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
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 …
Availability And Use Of Water In Nebraska, 1970, F. Butler Shaffer
Availability And Use Of Water In Nebraska, 1970, F. Butler Shaffer
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Eutrophication Factors In North Central Florida Lakes, H. D. Putnam, Patrick L. Brezonik, Earl E. Shannon
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 …
Upper Pennsylvanian Shoreline Deposits Form Iowa And Nebraska: Their Recognition, Variation, And Significance, J. A. Fagerstrom, R. R. Burchett
Upper Pennsylvanian Shoreline Deposits Form Iowa And Nebraska: Their Recognition, Variation, And Significance, J. A. Fagerstrom, R. R. Burchett
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Catechol Effected Dissolution Of Silicate Minerals, James Maurice Kelley
Catechol Effected Dissolution Of Silicate Minerals, James Maurice Kelley
Dissertations and Theses
The chemical properties of guanidinium tris(catecholato)siliconate, [(H₂N)₂C=NH₂]₂[Si(C₆H₄O₂)₃]·XH₂O (0 < X < 1), precipitated from an ammoniacal solution of silica and catechol by adding guanidinium hydrochloride, (H₂N)₂C=NH·HC1, were studied, and infrared, nmr, x-ray powder diffraction, and analytical data were gathered.
This same compound was, upon addition of' (H₂N)₂C=NH·HC1, isolated from 0.25, M aqueous catechol solutions buffered at pH 10 and containing the silicate minerals albite, andradite, muscovite, pyrophyllite, talc, and wollastonite, and also from unbuffered catechol solutions containing wollastonite and andradite.
It is concluded from this work that the formation of an anionic catechol-silicon complex, Si(C₆H₄O₂)₃²⁻, is largely responsible for the dissolution of the minerals mentioned above. From this conclusion, it is proposed that naturally occurring members of the class of organic compounds to which catechol belongs, the aromatic v̲i̲̲c̲-diols, may play …
Standing Crop And Productivity Of Marsh Vegetation At Saratoga Springs, California, W. G. Bradley
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
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
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
Ingestion Rates, Live Weight Caloric Densities And Standing Crop Estimates For Desert Biome Rodents, R. K. Schreiber, D. R. Johnson
Memorandum
No abstract provided.
Life History And Life Process Studies Of The Water Scavenger Beetle, Hydrophilus Triangularie Say, M. D. Hallmark, C. R. Ward
Life History And Life Process Studies Of The Water Scavenger Beetle, Hydrophilus Triangularie Say, M. D. Hallmark, C. R. Ward
Memorandum
No abstract provided.
Demography And Role Of Herbivorous Ants In A Desert Ecosystem As Functions Of Vegetation, Soil And Climate Variables, W. G. Whiteford, G. Ettershank
Demography And Role Of Herbivorous Ants In A Desert Ecosystem As Functions Of Vegetation, Soil And Climate Variables, W. G. Whiteford, G. Ettershank
Memorandum
No abstract provided.
The Geology Of The Southeast Quarter Of The Bone Mountain Quadrangle, Oregon, Richard Cortland Kent
The Geology Of The Southeast Quarter Of The Bone Mountain Quadrangle, Oregon, Richard Cortland Kent
Dissertations and Theses
This thesis is a study of the geology of the southeast quarter of the Bone Mountain Quadrangle. The bedrock geology mapped includes about 56 square miles.The Klamath Mountain and Coast Range Provinces of southwestern Oregon are represented in the area. Rocks in the area include the Rogue, Dothan Riddle, Days Creek, upper member of the Umpqua and Tyee Formations. The ages of these rocks range from Late Jurassic to middle Eocene. Late Jurassic ultramafic and mafic intrusive rocks associated with the Rogue Formation occur in the Klamath Province. The metavolcanics of the Rogue Format ion and an associated linear belt …
Radiative Environment And The Surface Temperature On A Microscale In A Sagebrush Biome, Inge Dirmhirn
Radiative Environment And The Surface Temperature On A Microscale In A Sagebrush Biome, Inge Dirmhirn
Memorandum
No abstract provided.
Gaseous Losses Of Nitrogen From The Soil Of Semi-Arid Regions, T. C. Tucker, R. L. Westerman
Gaseous Losses Of Nitrogen From The Soil Of Semi-Arid Regions, T. C. Tucker, R. L. Westerman
Memorandum
No abstract provided.