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Articles 1 - 23 of 23

Full-Text Articles in Physical Sciences and Mathematics

The Effectiveness Of The Asos, Mmts, Gill, And Crs Air Temperature Radiation Shields*, K. G. Hubbard, X. Lin, E.A. Walter-Shea Nov 2000

The Effectiveness Of The Asos, Mmts, Gill, And Crs Air Temperature Radiation Shields*, K. G. Hubbard, X. Lin, E.A. Walter-Shea

School of Natural Resources: Faculty Publications

Periodic upgrades of air temperature measurement systems in surface weather station networks cause data discontinuities. From a climatological viewpoint, it is necessary to evaluate the air temperature data discontinuities when air temperature radiation shields are upgraded. This study was undertaken to investigate the effectiveness of four common air temperature radiation shields including the Automated Surface Observing System (ASOS), the Maximum–Minimum Temperature System (MMTS), the Gill, and the Cotton Region Shelter (CRS) shields. The solar radiation shielding effectiveness for each shield under typical grass ground surface and different artificial surfaces (black, white, and aluminum) were investigated. The shield effectiveness was evaluated …


Ecology Of Elk In The Pine Ridge Region Of Northwestern Nebraska: Seasonal Distribution, Characteristics Of Wintering Sites, And Herd Health, Michael A. Cover Aug 2000

Ecology Of Elk In The Pine Ridge Region Of Northwestern Nebraska: Seasonal Distribution, Characteristics Of Wintering Sites, And Herd Health, Michael A. Cover

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.


Evaluation And Assessment Of Agrichemical Contaminants In The Creighton, Ne Area, Mark E. Burbach, Roy F. Spalding Jul 2000

Evaluation And Assessment Of Agrichemical Contaminants In The Creighton, Ne Area, Mark E. Burbach, Roy F. Spalding

School of Natural Resources: Faculty Publications

The Lewis and Clark Natural Resources District (LCNRD) has reported elevated nitrate- nitrogen (NO3-N) concentrations in ground water near Creighton, NE. The U.S. Environmental Protection Agency has set a maximum contaminant level (MCL) of 10 mg/L for NO3-N in public water supplies. NO3-N in the city of Creighton municipal drinking water wells and several rural domestic and irrigation wells have exceeded the MCL. The city of Creighton has constructed a reverse-osmosis water treatment system at a cost of $1.1 million to reduce the NO3-N concentration below the MCL in its water supply. In response to this NO3-N contamination problem the …


Airflow Characteristics Of Commonly Used Temperature Radiation Shields*, X. Lin, Kenneth G. Hubbard, George E. Meyer May 2000

Airflow Characteristics Of Commonly Used Temperature Radiation Shields*, X. Lin, Kenneth G. Hubbard, George E. Meyer

School of Natural Resources: Faculty Publications

The air temperature radiation shield is a key component in air temperature measurement in weather station networks; however, it is widely recognized that significant errors in the measured air temperature exist due to insufficient airflow past the air temperature sensor housed inside the shield. During the last several decades, the U.S. National Weather Service has employed a number of different shields in air temperature measurements. This paper focuses on the airflow characteristics inside air temperature shields including the Maximum–Minimum Temperature System (MMTS), the Gill shields, and the Cotton Region Shelter (CRS).

Average airspeed profiles and airflow efficiency inside the shields …


Changes In Primary Production Of Pawnee Reservoir As A Result Of Reservoir Aging, Kristopher A. Fischer May 2000

Changes In Primary Production Of Pawnee Reservoir As A Result Of Reservoir Aging, Kristopher A. Fischer

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.


Forestry's Role In Sustainable Agriculture, James R. Brandle Jan 2000

Forestry's Role In Sustainable Agriculture, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.


Determination Of Drag Properties Of A Shelterbelt From Measurements And A Numerical Model, James R. Brandle Jan 2000

Determination Of Drag Properties Of A Shelterbelt From Measurements And A Numerical Model, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.


Pressure Perturbations Around Shelterbelts: Measurements And Model Results, James R. Brandle Jan 2000

Pressure Perturbations Around Shelterbelts: Measurements And Model Results, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.


Windbreaks An Old System With A New Look, James R. Brandle Jan 2000

Windbreaks An Old System With A New Look, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.


Windbreaks: Are They Effective?, James R. Brandle Jan 2000

Windbreaks: Are They Effective?, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.


Silvopastoral Systems In The Pine Ridge Of Nebraska, James R. Brandle Jan 2000

Silvopastoral Systems In The Pine Ridge Of Nebraska, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.


The Effect Of Structure On The Drag Force Of A Windbreak, James R. Brandle Jan 2000

The Effect Of Structure On The Drag Force Of A Windbreak, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.


Windbreak Practices, James R. Brandle Jan 2000

Windbreak Practices, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.


Oxygen Budget For Lake Ogallala, Kyle D. Hoagland, John C. Holz, Tadd M. Barrow, Richard J. Ruane Jan 2000

Oxygen Budget For Lake Ogallala, Kyle D. Hoagland, John C. Holz, Tadd M. Barrow, Richard J. Ruane

School of Natural Resources: Faculty Publications

Lake Ogallala, located below Kingsley Dam which impounds Lake McConaughy in Keith County, Nebraska, is a 260-surface hectare lake with an average depth of approximately eight meters. The lake provides mUltiple uses including a sport fishery and a hydropower and irrigation regulation basin. Since the installation of the hydroelectric generating plant in 1984 (Kingsley Dam was constructed in 1942) and the continued eutrophication of Lake McConaughy, dissolved oxygen concentrations have generally declined in Lake Ogallala. Hypolimnetic withdrawal from Lake McConaughy results in depressed oxygen levels in Lake Ogallala during the mid to latter part of the summer, particularly in certain …


Late Albian Kiowa-Skull Creek Marine Transgression, Lower Dakota Formation, Eastern Margin Of Western Interior Seaway, R.L. Brenner, G.A. Ludvigson, B.J. Witzke, A.N. Zawistoski, E.P. Kvale, R.L. Ravn, R.M. Joeckel Jan 2000

Late Albian Kiowa-Skull Creek Marine Transgression, Lower Dakota Formation, Eastern Margin Of Western Interior Seaway, R.L. Brenner, G.A. Ludvigson, B.J. Witzke, A.N. Zawistoski, E.P. Kvale, R.L. Ravn, R.M. Joeckel

School of Natural Resources: Faculty Publications

No abstract provided.


Breeding Season Demography And Movements Of Eastern Towhees At The Savannah River Site, South Carolina, David G. Krementz, Larkin A. Powell Jan 2000

Breeding Season Demography And Movements Of Eastern Towhees At The Savannah River Site, South Carolina, David G. Krementz, Larkin A. Powell

School of Natural Resources: Faculty Publications

The Eastern Towhee (Pipilo erythrophthalmus) has undergone population declines across much of its range, especially in New England. Despite being a widespread and, at one time, a common species, relatively little is known about its natural history, ecology, or demographics. We conducted baseline research on Eastern Towhees at the Savannah River Site, South Carolina, in 1995 and 1996 to estimate breeding season survival rates, nest success rates, breeding densities, and daily movements. We also were interested in whether towhees had differences in survival and movement rates between young and mature managed pine stands. We found that survival rates during the …


Parental Care And Clutch Sizes In North And South American Birds, Thomas E. Martin, P. R. Martin, C. R. Olson, B. J. Heidinger, J. J. Fontaine Jan 2000

Parental Care And Clutch Sizes In North And South American Birds, Thomas E. Martin, P. R. Martin, C. R. Olson, B. J. Heidinger, J. J. Fontaine

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

The evolutionary causes of small clutch sizes in tropical and Southern Hemisphere regions are poorly understood. Alexander Skutch proposed 50 years ago that higher nest predation in the south constrains the rate at which parent birds can deliver food to young and thereby constrains clutch size by limiting the number of young that parents can feed. This hypothesis for explaining differences in clutch size and parental behaviors between latitudes has remained untested. Here, a detailed study of bird species in Arizona and Argentina shows that Skutch's hypothesis explains clutch size variation within North and South America. However, neither Skutch's hypothesis …


Shrinkage Of Inland Silverside Larvae Preserved In Ethanol And Formalin, Mandy K. Cunningham, William F. Granberry, Kevin L. Pope Jan 2000

Shrinkage Of Inland Silverside Larvae Preserved In Ethanol And Formalin, Mandy K. Cunningham, William F. Granberry, Kevin L. Pope

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Length measurements of preserved larval fish are necessary in many types of larval fish surveys. If the fixative causes significant shrinkage, then the preserved lengths cannot be used to indicate accurate live lengths. The objective of this study was to determine how preservation in two different concentrations of formalin and ethanol affects the total length of larval inland silversides Menidia beryllina. Larvae were measured (nearest 0.1 mm) and individually fixed in one of four fixative treatments (80% ethanol, 100% ethanol, 5% buffered formalin, and 10% buffered formalin). Fish were remeasured (nearest 0.1 mm) at 15 min; 4 h; and …


Natural And Anthropogenic Influences On The Distribution Of The Threatened Neosho Madtom In A Midwestern Warmwater Stream, Mark L. Wildhaber, Vernon M. Tabor, Daniel W. Mulhern, Kenneth L. Powell, Scott P. Sowa Jan 2000

Natural And Anthropogenic Influences On The Distribution Of The Threatened Neosho Madtom In A Midwestern Warmwater Stream, Mark L. Wildhaber, Vernon M. Tabor, Daniel W. Mulhern, Kenneth L. Powell, Scott P. Sowa

United States Geological Survey: Staff Publications

We attempted to discern the contributions of physical habitat, water chemistry, nutrients, and contaminants from historic lead-zinc mining activities on the riffle-dwelling benthic fish community of the Spring River, a mid western warm water stream that originates in Missouri and flows into Kansas and Oklahoma. The Spring River has a fish community that includes the Neosho madtom Noturus placidus, a species federally listed as threatened. Although anthropogenic factors such as contaminants limited populations and densities of fishes, an integrated assessment of natural and anthropogenic factors was necessary to effectively estimate the influence of the latter. Fish populations in the …


Geomorphometry – Diversity In Quantitative Surface Analysis, Richard J. Pike Jan 2000

Geomorphometry – Diversity In Quantitative Surface Analysis, Richard J. Pike

United States Geological Survey: Staff Publications

A widening variety of applications is diversifying geomorphometry (digital terrain modelling), the quantitative study of topography. An amalgam of earth science, mathematics, engineering and computer science, the discipline has been revolutionized by the computer manipulation of gridded terrain heights, or digital elevation models (DEMs). Its rapid expansion continues. This article reviews the remarkable diversity of recent morphometric work in 15 selected topics and discusses their significance and prospects. The quantitative analysis of industrial microsurface topography is introduced to the earth science community. The 14 other topics are Internet access to geomorphometry; global DEMs; DEM modelling of channel networks; …


Single-Dilution Enzyme-Linked Immunosorbent Assay For Quantification Of Antigen-Specific Salmonid Antibody, Stewart W. Alcorn, Ronald J. Pascho Jan 2000

Single-Dilution Enzyme-Linked Immunosorbent Assay For Quantification Of Antigen-Specific Salmonid Antibody, Stewart W. Alcorn, Ronald J. Pascho

United States Geological Survey: Staff Publications

An enzyme-linked immunosorbent assay (ELISA) was developed on the basis of testing a single dilution of serum to quantify the level of antibody to the p57 protein of Renibacterium salmoninarum in sockeye salmon (Oncorhynchus nerka). The levels of antibody were interpolated from a standard curve constructed by relating the optical densities (OD) produced by several dilutions of a high-titer rainbow trout (O. mykiss) antiserum to the p57 protein. The ELISA OD values produced by as many as 36 test sera on each microplate were compared with the standard curve to calculate the antigen-specific antibody activity. Repeated …


Dating Marine Terraces With Relative-Age And Correlated-Age Methods, Daniel R. Muhs Jan 2000

Dating Marine Terraces With Relative-Age And Correlated-Age Methods, Daniel R. Muhs

United States Geological Survey: Staff Publications

Coastal landforms, and particularly emergent marine terraces, a re amongt he most importantg eomorphicfe aturesi n studieso f Quaternarys eal evel fluctuationsa nd neotectonics. A general model, first articulated by Alexander (1953) and borne out by detailedr ecent studieso n many coastlinesi,s that emergent flights of erosional terraces and coral reefs (Fig. 1) are the resulto f glacioeustaticallyc ontrolledf luctuations of global sea level superimposed on steady uplift. Similiarity of U-series ages of coral from both constructional reefsi n the tropicsa nd erosionalt erracesi n midlatitudesh as provided a rigorous test of this model (Mesolella and others, 1969; Bloom and …


Characterization And Improvement Of Eos Land Products Using Measurements At Ameriflux Grassland And Wheat Sites In The Arm/Cart Region: Research Annual Performance Report For Period March 1, 2000- February 28, 2001, E. A. Walter-Shea, S. B. Verma Jan 2000

Characterization And Improvement Of Eos Land Products Using Measurements At Ameriflux Grassland And Wheat Sites In The Arm/Cart Region: Research Annual Performance Report For Period March 1, 2000- February 28, 2001, E. A. Walter-Shea, S. B. Verma

School of Natural Resources: Documents and Reviews

No abstract provided.