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Articles 7921 - 7950 of 9404
Full-Text Articles in Entire DC Network
Bacteriological Water Quality Of Forested And Pastured Streams Receiving Land-Applied Poultry Litter, Matthew W. Mcbroom, Chang Mingteh, Charles Wells
Bacteriological Water Quality Of Forested And Pastured Streams Receiving Land-Applied Poultry Litter, Matthew W. Mcbroom, Chang Mingteh, Charles Wells
Faculty Publications
Poultry production is a growing industry in East Texas, generating about 360,000 m tons of broiler litter each year as a by-product for application on pasturelands. Grab samples of fecal coliform (FC) and fecal streptococcus (FS) were collected monthly between March and December 1996 and FC and E-coli samples were collected weekly between July and October 2001 at six sites on the Waffelo and Terrapin Creeks in Nacogdoches County, Texas to assess possible impacts of poultry litter application on bacterial water quality. Sites were grouped by three pairs with each pair consisting of one upstream site in predominantly forested area …
West Mortlock Catchment Appraisal 2002, D G. Cummins
West Mortlock Catchment Appraisal 2002, D G. Cummins
Resource management technical reports
This report describes the soils, hydrology, natural vegetation and farming systems of the West Mortlock catchment and provides information on the threats to agriculture, infrastructure and natural resources caused by land degradation. West Mortlock covers over 700,000 hectares in the central wheatbelt. Rapid Catchment Appraisal aims to document salinity risk and management options by addressing all threats to the natural resource base, rather than isolating salinity as a separate issue.
Sequence Stratigraphy And Depositional Facies Of Lower Ordovician Cyclic Carbonate Rocks, Southern Missouri, U.S.A., Robert Brandon Overstreet, Francisca Oboh-Ikuenobe, Jay M. Gregg
Sequence Stratigraphy And Depositional Facies Of Lower Ordovician Cyclic Carbonate Rocks, Southern Missouri, U.S.A., Robert Brandon Overstreet, Francisca Oboh-Ikuenobe, Jay M. Gregg
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
Lower Ordovician cyclic carbonate strata of southern Missouri were deposited in a warm, shallow, epeiric sea on a fully aggraded carbonate platform. Sedimentological characteristics distinguish the Jefferson City and Cotter dolomites from the underlying Gasconade and Roubidoux formations. Mixed carbonate-siliciclastic sedimentation characterizes the Roubidoux Formation, with sandstones accounting for up to 60% of sedimentation. The Gasconade, Jefferson City, and Cotter dolomites exhibit an increased occurrence of chalcedonic chert nodules in very similar shape and texture to the gypsum and anhydrite nodules common on modern sabkha supratidal flats. Casts of halite and ghosts of gypsum laths also exist in the Jefferson …
Understanding Wavelet Analysis And Filters For Engineering Applications, Chethan Bangalore Parameswariah
Understanding Wavelet Analysis And Filters For Engineering Applications, Chethan Bangalore Parameswariah
Doctoral Dissertations
Wavelets are signal-processing tools that have been of interest due to their characteristics and properties. Clear understanding of wavelets and their properties are a key to successful applications. Many theoretical and application-oriented papers have been written. Yet the choice of a right wavelet for a given application is an ongoing quest that has not been satisfactorily answered. This research has successfully identified certain issues, and an effort has been made to provide an understanding of wavelets by studying the wavelet filters in terms of their pole-zero and magnitude-phase characteristics. The magnitude characteristics of these filters have flat responses in both …
A Geochemical Survey Of The Natural Waters Of Belize, Central America, Anthony D. Marfia
A Geochemical Survey Of The Natural Waters Of Belize, Central America, Anthony D. Marfia
Masters Theses
A geochemical survey of the natural waters in Belize, Central America was carried out to compliment routine water quality analysis and to identify processes affecting water quality. The objective of this research was to provide a geochemical assessment of natural waters throughout Belize by examining select major ions (Ca2+, Mg2+ , SO42-), and stable isotopes of carbon (13C), oxygen (18O) and hydrogen (2H).
The dominant geology relevant to this investigation comprises a varied landscape of carbonates and elastic sediments in a subtropical rainforest/savannah climate. Stable oxygen and hydrogen …
The Development Of Relationships Between Constituent Concentrations And Generic Hydrological Variables, Carmen T. Agouridis, Dwayne R. Edwards
The Development Of Relationships Between Constituent Concentrations And Generic Hydrological Variables, Carmen T. Agouridis, Dwayne R. Edwards
Biosystems and Agricultural Engineering Faculty Publications
The collection and analysis of samples from storm events constitutes a large portion of the effort associated with water quality research. Estimating concentrations or loads from these events is often difficult. The equipment necessary to analyze the samples and the required laboratory resources are typically significant expenses incurred by the researcher. One potential method to reduce these costs is through the development of generic relationships between concentrations and easily measured variables such as dimensionless flow rate or time. The benefits recognized from such an effort include a reduction in the number of required samples, resulting in a reduction in cost. …
Water-Quality Assessment Of The Central Nebraska Basins-— Enering A New Decade, Ronald B. Zelt, Jill D. Frankforter
Water-Quality Assessment Of The Central Nebraska Basins-— Enering A New Decade, Ronald B. Zelt, Jill D. Frankforter
United States Geological Survey: Publications
In 2001, the U.S. Geological Survey’s (USGS) National Water- Quality Assessment (NAWQA) Program began its second decade of intensive water-quality assessments (Cycle II). NAWQA scientists plan to revisit 42 major river-basin and aquifer systems (called study units) that were assessed in the first decade (Gilliom and others, 2001).
The Application Of A Diatom-Based Transfer Function To Evaluate Regional Water-Quality Trends In Minnesota Since 1970, J. M. Ramstack, Sherilyn C. Fritz, D. R. Engstrom, S. A. Heiskary
The Application Of A Diatom-Based Transfer Function To Evaluate Regional Water-Quality Trends In Minnesota Since 1970, J. M. Ramstack, Sherilyn C. Fritz, D. R. Engstrom, S. A. Heiskary
Department of Earth and Atmospheric Sciences: Faculty Publications
Significant population growth over the last three decades, as well as efforts to improve surface-water quality mandated by the Clean Water Act, potentially have had opposing influences on aquatic ecosystems in the U.S. Because historical data on water-quality trends are limited over this time period, we developed a diatom-based transfer function to reconstruct chloride, color, acid neutralizing capacity (ANC), total phosphorus (TP), and pH in 55 Minnesota lakes. The lakes span three different ecoregions, as well as the Twin Cities metropolitan area, and differ in their history of settlement and land use, and in surficial geology, climate, and vegetation. Lakes …
Producing Quality Alfalfa Hay, Jimmy C. Henning, Garry D. Lacefield
Producing Quality Alfalfa Hay, Jimmy C. Henning, Garry D. Lacefield
Kentucky Alfalfa and Stored Forage Conference
Hay is one of the most versatile of stored forages in that (1) it can be kept for long periods of time with little loss of nutrients if protected from weather; (2) a large number of crops can be successfully used for hay production; (3) it can be produced and fed in small or large amounts; (4) it can be harvested, stored and fed by hand or the production and feeding can be completely mechanized; and (5) hay can supply most nutrients needed by many classes of livestock. Hay is, therefore, the most commonly used stored feed on most farms.
Buying And Selling Alfalfa Hay, Garry D. Lacefield, Jimmy C. Henning
Buying And Selling Alfalfa Hay, Garry D. Lacefield, Jimmy C. Henning
Kentucky Alfalfa and Stored Forage Conference
Alfalfa hay is an important agricultural product. Although often fed on the farms where it is produced, much alfalfa hay is also sold as a cash crop. It often constitutes a major source of income for those who sell it, or a major expense for those who buy it. Such transactions involve billions of dollars nationwide each year.
Alfalfa, The Queen Of Forage Crops — Reflections After Sixty Years Experience With The Crop, Warren C. Thompson
Alfalfa, The Queen Of Forage Crops — Reflections After Sixty Years Experience With The Crop, Warren C. Thompson
Kentucky Alfalfa and Stored Forage Conference
Yes, it is true I have been involved with alfalfa for 60 years and then some. Fact is I was fortunate enough to pick the World's best forage on which to base much of my career about the same time I fell in love with and married the best lady I ever knew. Betty has stuck with me through these crazy wonderful years. She was largely responsible for matters at home and raising the family. She managed our family and home while I was on the move trying to encourage maybe even coerce farmers in Kentucky and then over the …
Advances In Developing Better Alfalfa Varieties, Jim Moutray
Advances In Developing Better Alfalfa Varieties, Jim Moutray
Kentucky Alfalfa and Stored Forage Conference
Alfalfa breeders continue to actively pursue the development of varieties that will bring more benefits to farmers. Yield and better persistence are our highest priorities. Other traits under selection can make alfalfa easier and cheaper to grow, better and safer for livestock and more attractive to livestock.
The goal of this paper is to update you on the types of alfalfa research going on in the U.S., time tables on when you may expect to see these new developments and how they may help you in your operation.
Alfalfa Hay Quality: Terms And Definitions, Garry D. Lacefield
Alfalfa Hay Quality: Terms And Definitions, Garry D. Lacefield
Kentucky Alfalfa and Stored Forage Conference
At the 22nd Kentucky Alfalfa Conference we discussed the relationship among Alfalfa - Yield-Quality-Persistence. In our presentation, we indicated that all three components must be considered for best management of alfalfa stands. Over the past week, I have looked through the past twenty-two years of Alfalfa Conference Proceedings. It's interesting, but not surprising that we have focused far more attention on yield than on quality and/or persistence.
Alfalfa yield (quantity) and quality are both important; however, it is easier for producers to recognize problems associated with quantity than quality because quantity can be easily assessed visually. Thus, forage quantity …
Vegetation Establishment For Erosion Control Under Simulated Rainfall, Brent G. Hallock, Misty Scharff, Steve Rein, Kaila Dettman
Vegetation Establishment For Erosion Control Under Simulated Rainfall, Brent G. Hallock, Misty Scharff, Steve Rein, Kaila Dettman
Earth and Soil Sciences
The California Department of Transportation (Caltrans) manages rights of ways that transect 41 m H (101m ac) and span over 3000 m (9000 ft) in elevation from seashore to sup alpine. There are approximately 4,900 native and 1,000 naturalized alien plant species in California. Only a few hundred are reliably useful in erosion and sediment control. Specifying native and naturalized vegetation mixes for use in hydroseeding or plug planting in conjunction with mechanical erosion control methods can have varying result for minimizing accelerated soil erosion. To investigate these factors, Cal Poly, San Luis Obispo, in conjunction with Caltrans and CSU, …
Geographic Information System Methodologies To Evaluate Relationships Between Land Use And Groundwater Quality In South Central Kentucky, Rhonda Pfaff
Masters Theses & Specialist Projects
The development of Geographic Information System (GIS) technology has provided techniques for a holistic approach to the study of karst groundwater contamination. While karst groundwaters supply water to a large percentage of the earth's population, its complex environments often have lacked the scientific examination and conservation measures typical of non-karst regions. In this study, GIS methodologies were explored to examine the relationships between land-use and water quality in karst watersheds. Eight watersheds throughout southern and western Kentucky were examined. The study areas included the Mammoth Cave Karst Aquifer, which is the watershed that drains the Mammoth Cave System, and seven …
Sediment Transport By Dry Ravel, Emmanuel Gabet
Sediment Transport By Dry Ravel, Emmanuel Gabet
Faculty Publications
Dry ravel is a general term that describes the rolling, bouncing, and sliding of individual particles down a slope and is a dominant hillslope sediment transport process in steep arid and semiarid landscapes. During fires, particles can be mobilized by the collapse of sediment wedges that have accumulated behind vegetation. On a daily basis, particles may be mobilized by bioturbation and by small landslides. Experiments on a dry ravel flume indicate that a basic expression of the momentum equation predicts the distance traveled by particles propelled down a rough surface. This equation is further elaborated to produce a nonlinear slope-dependent …
Magmatic Subsidence Of The East Pacific Rise (Epr) At 18˚14'S Revealed Through Fault Restoration Of Ridge Crest Bathymetry, S M. Carbotte, William B F Ryan, Wen Jin, Marie-Helene Cormier, Eric Bergmanis, John Sinton, Scott M. White
Magmatic Subsidence Of The East Pacific Rise (Epr) At 18˚14'S Revealed Through Fault Restoration Of Ridge Crest Bathymetry, S M. Carbotte, William B F Ryan, Wen Jin, Marie-Helene Cormier, Eric Bergmanis, John Sinton, Scott M. White
Faculty Publications
The fault restoration technique of De Chabalier and Avouac [1994] is applied to an ultra-highresolution bathymetry data set from the East Pacific Rise (EPR) at 18140S. Fault offsets are calculated and subtracted from the original seafloor bathymetry to examine the morphology of the unfaulted seafloor surface within an area encompassing the ridge axis 400 [1] 1600 m in dimension. The restored topography reveals a gently sloping seafloor 200 m wide, which slopes 5 inward toward the spreading axis. We attribute this inward sloping seafloor to subsidence within the axial trough due to subsurface magmatic deflation. The vertical deformation field extracted …
Sizes And Shapes Of 10-Ma Distal Fall Pyroclasts In The Ogallala Ggroup, Nebraska, William I. Rose, C. M. Riley, S. Dartevelle
Sizes And Shapes Of 10-Ma Distal Fall Pyroclasts In The Ogallala Ggroup, Nebraska, William I. Rose, C. M. Riley, S. Dartevelle
Department of Geological and Mining Engineering and Sciences Publications
Size distributions of distal ashfall particles from correlated 10-Ma layers in Nebraska, measured using laser diffraction methods, are lognormal with mode diameters of ∼90 mm. This ashfall is ∼100% bubble-wall shards of rhyolite glass and apparently represents a distal ashfall from an eruption 1400 km away. Measured terminal velocities of these ash particles are 0.2–18 cm/s, consistent with Stokes Law settling of spherical particles with diameters of 9–50 mm. Surface area of the ash particles, measured with gas adsorption, is 20–30 times the surface area of equivalent Stokes spheres. These results highlight the effects of shape and atmospheric drag in …
A Watershed Analysis Of Threemile Pond: Implications For Water Quality And Land Use Management, Colby Environmental Assessment Team, Colby College, Problems In Environmental Science Course (Biology 493), Colby College
A Watershed Analysis Of Threemile Pond: Implications For Water Quality And Land Use Management, Colby Environmental Assessment Team, Colby College, Problems In Environmental Science Course (Biology 493), Colby College
Colby College Watershed Study: Threemile Pond (2003)
The 2003 Colby Environmental Assessment Team chose to study the Threemile Pond watershed. The Threemile Pond watershed is located in Vassalboro, China., Windsor, and Augusta, Maine. Threemile Pond is a popular site for recreation and is home to a wide range of flora and fauna. Like all other lakes in Maine, it is a young lake. However, intensive human activity in the watershed contributes a substantial amount of nutrients and the lake has algal blooms annually in the summer months. The purpose of this study was to assess the impact of land use and development on the water quality of …
Natural Resource Management Issues In The Agricultural Zone Of Western Australia : South West Region, B Nicholas, Paul Galloway, Peter J. Tille, Angela Stuart-Street, Heather M. Percy
Natural Resource Management Issues In The Agricultural Zone Of Western Australia : South West Region, B Nicholas, Paul Galloway, Peter J. Tille, Angela Stuart-Street, Heather M. Percy
Resource management technical reports
Provides and analysis of current pressures on agricultural resources of the South West region of Western Australia. Differing ranges of risks are shown for different degradation issues because of various impacts. Each natural resource management issues covers nature and extent of susceptibility, impacts on agriculture and the environment, management options and effectiveness of management options.
Selectivities Of Potassium-Calcium And Potassium-Lead Exchange In Two Tropical Soils, Chip Appel, Lena Q. Ma, R. Dean Rhue, William Reve
Selectivities Of Potassium-Calcium And Potassium-Lead Exchange In Two Tropical Soils, Chip Appel, Lena Q. Ma, R. Dean Rhue, William Reve
Earth and Soil Sciences
Measurement of cation selectivity in soils provides important information about the affinity and binding strength of a particular cation on soil surfaces. Gaines-Thomas (KGT) selectivity coefficients were determined for a variety of K/Ca and K/Pb ratios on an Oxisol and Ultisol soil from Puerto Rico. The calculated KGT values indicated a preference for K+ over Ca2+ or Pb2+. The selectivity for Pb2+ was significantly greater than that for Ca2+ due to Pb2+'s larger hydrated charge density relative to that of Ca2+. The patterns of selectivity were independent …
Monitoring Trends In Bat Populations Of The United States And Territories: Problems And Prospects, T.J. O'Shea, M. A. Bogan
Monitoring Trends In Bat Populations Of The United States And Territories: Problems And Prospects, T.J. O'Shea, M. A. Bogan
United States Geological Survey: Publications
Bats are ecologically and economically important mammals. The life histories of bats (particularly their low reproductive rates and the need for some species to gather in large aggregations at limited numbers of roosting sites) make their populations vulnerable to declines. Many of the species of bats in the United States (U.S.) and territories are categorized as endangered or threatened, have been candidates for such categories, or are considered species of concern. The importance and vulnerability of bat populations makes monitoring trends in their populations a goal for their future management. However, scientifically rigorous monitoring of bat populations requires well-planned, statistically …
Geologic Studies Of Mercury By The U.S. Geological Survey
Geologic Studies Of Mercury By The U.S. Geological Survey
United States Geological Survey: Publications
A liquid at room temperature, mercury is a unique metal with unusual properties. Elemental mercury has long been used in thermometers because it responds to changes in temperature. In fact, mercury’s many diverse properties have made it useful for many products. Mercury is a good metallic conductor with a low electrical resistivity; it has been used in electrical products including electrical wiring and switches, fluorescent lamps, mercury batteries, and thermostats (Eisler, 1987). Mercury also is used in navigational instruments to measure changes in temperature and pressure. In the medical field, mercury is used as a component in dental fillings and …
Review Of Population Viability Analysis, Mark W. Miller
Review Of Population Viability Analysis, Mark W. Miller
United States Geological Survey: Staff Publications
Population viability analysis (PVA) historically has been used to estimate the probability that a population will become extinct within a given time period. More recently, PVA has been used to evaluate alternative management strategies. Some might even say PVA gave rise to conservation biology. Nevertheless, PVA has been heavily criticized. This is the second book to present a synthesis and address those concerns. It does so extremely well.
Genetic Variation In Black Bears In Arkansas And Louisiana Using Microsatellite Dna Markers, Ildiki Csiki, Cynthia Lam, Audie Key, Erica Coulter, Joseph D. Clark, Richard M. Pace Iii, Kimberley G. Smith, Douglas D. Rhoads
Genetic Variation In Black Bears In Arkansas And Louisiana Using Microsatellite Dna Markers, Ildiki Csiki, Cynthia Lam, Audie Key, Erica Coulter, Joseph D. Clark, Richard M. Pace Iii, Kimberley G. Smith, Douglas D. Rhoads
United States Geological Survey: Staff Publications
In the 1950s and 1960s, translocation projects reintroduced black bears (Ursus americanus) from Minnesota and Manitoba to Arkansas and Louisiana. Today, several geographically disconnected populations exist in Arkansas and Louisiana, but their origins are unclear. Some populations may represent a separate subspecies, U. a. luteolus, which is federally protected. We characterized 5 microsatellite loci in 5 isolated populations in Arkansas and Louisiana and compared them with genotypes from Minnesota. Our data indicate that bears of the Ozark and Ouachita mountains of Arkansas, an inland area of Louisiana, and those of Minnesota are similar in overall genetic diversity …
Evidence For Disease-Related Amphibian Decline In Colorado, Erin Muths, Paul Stephen Corn, Allan P. Pessier, D. Earl Green
Evidence For Disease-Related Amphibian Decline In Colorado, Erin Muths, Paul Stephen Corn, Allan P. Pessier, D. Earl Green
United States Geological Survey: Staff Publications
The recent discovery of a pathogenic fungus (Batrachochytrium dendrobatidis) associated with declines of frogs in the American and Australian tropics, suggests that at least the proximate cause, may be known for many previously unexplained amphibian declines. We have monitored boreal toads in Colorado since 1991 at four sites using capture–recapture of adults and counts of egg masses to examine the dynamics of this metapopulation. Numbers of male toads declined in 1996 and 1999 with annual survival rate averaging 78% from 1991 to 1994, 45% in 1995 and 3% between 1998 and 1999. Numbers of egg masses also declined. …
Unprecedented Last-Glacial Mass Accumulation Rates Determined By Luminescence Dating Of Loess From Western Nebraska, Helen M. Roberts, Daniel R. Muhs, Ann G. Wintle, Geoff A. T. Duller, E. Arthur Bettis Iii
Unprecedented Last-Glacial Mass Accumulation Rates Determined By Luminescence Dating Of Loess From Western Nebraska, Helen M. Roberts, Daniel R. Muhs, Ann G. Wintle, Geoff A. T. Duller, E. Arthur Bettis Iii
United States Geological Survey: Staff Publications
A high-resolution chronology for Peoria (last glacial period) Loess from three sites in Nebraska, midcontinental North America, is determined by applying optically stimulated luminescence (OSL) dating to 35–50 µm quartz. At Bignell Hill, Nebraska, an OSL age of 25,000 yr near the contact of Peoria Loess with the underlying Gilman Canyon Formation shows that dust accumulation occurred early during the last glacial maximum (LGM), whereas at Devil’s Den and Eustis, Nebraska, basal OSL ages are significantly younger (18,000 and 21,000 yr, respectively). At all three localities, dust accumulation ended at some time after 14,000 yr ago. Mass accumulation rates …
Mapping Vegetation In Yellowstone National Park Using Spectral Feature Analysis Of Aviris Data, Raymond F. Kokaly, Don G. Despain, Roger N. Clark, K. Eric Livo
Mapping Vegetation In Yellowstone National Park Using Spectral Feature Analysis Of Aviris Data, Raymond F. Kokaly, Don G. Despain, Roger N. Clark, K. Eric Livo
United States Geological Survey: Staff Publications
Knowledge of the distribution of vegetation on the landscape can be used to investigate ecosystem functioning. The sizes and movements of animal populations can be linked to resources provided by different plant species. This paper demonstrates the application of imaging spectroscopy to the study of vegetation in Yellowstone National Park (Yellowstone) using spectral feature analysis of data from the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS). AVIRIS data, acquired on August 7, 1996, were calibrated to surface reflectance using a radiative transfer model and field reflectance measurements of a ground calibration site. A spectral library of canopy reflectance signatures was created by …
Holocene Paleoflood Hydrology Of The Lower Deschutes River, Oregon, Kurt J. Hosman, Lisa L. Ely, Jim E. O'Connor
Holocene Paleoflood Hydrology Of The Lower Deschutes River, Oregon, Kurt J. Hosman, Lisa L. Ely, Jim E. O'Connor
Student Published Works
Flood deposits at four sites along the lower Deschutes River, Oregon, were analyzed to determine magnitude and frequency of late Holocene flooding. Deposit stratigraphy was combined with hydraulic modeling at two sites to determine ranges of likely discharges for individual deposits. Combining these results with gaged flood data provides improved flood frequency estimates at the Axford site. The completeness and age spans of preserved flood chronologies differed among the four sites, but results were consistent for the largest floods of the last 5000 years. Single floods exceeded 2860-3800 mVs -4600 cal yr BP, 1060-1810 mVs -1300 cal yr BP, and …
Phosphorus Contamination And Storage In Bottom Sediments Of The James River Arm Of Table Rock Lake, Southwest Missouri, Marc R. Owen
Phosphorus Contamination And Storage In Bottom Sediments Of The James River Arm Of Table Rock Lake, Southwest Missouri, Marc R. Owen
Graduate Theses/Dissertations
Eutrophic conditions in the upper James River Arm (JRA) of Table Rock Lake have been linked to phosphorus (P) inputs by wastewater treatment facilities and increasing urban development in the upper James River Basin (3,770 km2). Since the majority of P in aquatic environments is bound to sediments, bottom sediment can function as both a source and sink of P in lake systems. This study evaluates the spatial distribution, physical and chemical characteristics, and storage of sediment-P in the active layer ( < 5cm) of bottom sediments in the JRA. The JRA makes up about 20% of Table Rock Lake’s surface area, contributes about 30% of the inflow, and has the poorest water quality of the entire lake. For this study, grab samples were collected in the main arm and tributary coves at the deepest part of the lake and at several shallow sites along the main arm. Concentrations increase in a down-lake direction in the main arm ranging from 5 to >2000 ppm P. However, water-column P concentrations show a decrease down-lake, indicating that sedimentation is removing P from …