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Articles 16261 - 16290 of 17789
Full-Text Articles in Entire DC Network
Post-Middle Miocene Geologic History Of The Tualatin Basin, Oregon With Hydrogeologic Implications, Doyle Coley Wilson
Post-Middle Miocene Geologic History Of The Tualatin Basin, Oregon With Hydrogeologic Implications, Doyle Coley Wilson
Dissertations and Theses
The geologic history and sedimentary till of the Tualatin Basin after Columbia River Basalt Group (CRBG) emplacement is assessed and related to groundwater characteristics. The 334 m deep HBD-1 core from the Hillsboro Airport, provides the primary information for sediment characterization and is supported by over 2400 well logs and cores, and four seismic lines. The sedimentary section above the 26 m thick paleosol on the CRBG in HBD-I is divided into two main groups: a 25 m thick section of Missoula flood sediments called the Willamette Silt overlies a 263 m thick finegrained sequence of fluvial Neogene sediments.
Pollen, …
A Hydrogeochemical Study Of The Evolution Of The Headwaters Of The Bear River In The Uinta Mountains, Utah, Michael F. Leschin
A Hydrogeochemical Study Of The Evolution Of The Headwaters Of The Bear River In The Uinta Mountains, Utah, Michael F. Leschin
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The headwaters of the Bear River in the Uinta Mountains of Utah provide a good setting in which to examine the influence of geological materials on stream chemistry. Ionic contributions to the stream-water from soils, vegetation, and the atmosphere generally are sparse enough that they do not mask the geologic contributions. Samples from 37 sites on the four major headwater streams and several minor tributaries were examined geochemically. Data derived from the samples allowed the construction of a hydrogeochemical weathering model specific to the study area. A significant feature of this model is that carbonic acid is the dominant chemical …
Identification Of Belowground Woody Structures Using Molecular Biomarkers, Benny R. Bobowski
Identification Of Belowground Woody Structures Using Molecular Biomarkers, Benny R. Bobowski
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Within the last two decades substantial progress has been made in understanding seed bank dynamics and the contribution of the soil seed bank to a post-disturbance plant community. There has been relatively little progress, however, in understanding perennial bud bank dynamics and the contribution of the soil bud bank to secondary succession. This lack of information is due primarily to the inability to reliably identify roots, rhizomes, and lignotubers that lie dormant beneath the soil surface. This scientific investigation, therefore, addressed the issue of identification of belowground woody structures.
The first objective was to develop a methodology that utilizes molecular …
Thermal Characterization Of Ground And Surface Waters At The Upjohn Company's Portage Road Manufacturing Facility, William K. Hunsberger
Thermal Characterization Of Ground And Surface Waters At The Upjohn Company's Portage Road Manufacturing Facility, William K. Hunsberger
Masters Theses
This study focused on thermal characteristics of the ground water and recharged surface water at The Upjohn Company's (now Pharmacia and Upjohn) Portage Road manufacturing facility. Major objectives were: (a) a compilation and graphical evaluation of historical lower aquifer ground water temperatures; (b) estimates of thermal energy introduced into the ground water system through recharge from Upjohn Pond, and predictions of future production well discharge temperatures; (c) an evaluation of hydraulic conductivity related to changes in water density and viscosity influenced by variable temperature; and (d) the stratigraphy beneath Upjohn Pond.
Records reveal increasing ground water temperatures through time in …
Reconstruction Of Wetland Hydrology Dynamics Using Tree Rings, Allan P. Hascall Iii
Reconstruction Of Wetland Hydrology Dynamics Using Tree Rings, Allan P. Hascall Iii
Dissertations
Increment core samples were collected and examined to test the hypothesis that the history of punctuated or intermediate-term changes in wetland soil-moisture conditions can be reconstructed from the annual growth-ring record of trees. The hypothesis is based on plant physiological principles that indicate a relationship between water surplus stress and impaired physiological activity that could lead to reduced growth.
Sampling sites were selected for their ostensible historic hydrologic variability and the availability of documentation of hydrologic disturbances. A conceptual model was developed by which trees were sampled along a hydrotopographic gradient for comparison of radial stem growth in uplands versus …
The Columbia Slough, Scott A. Wells
The Columbia Slough, Scott A. Wells
Civil and Environmental Engineering Faculty Publications and Presentations
This report was written in an attempt to provide the public and Bureau of Environmental Services Staff with a summary of work accomplished on the Columbia Slough system by Portland State University and other consultants working on the Slough over the last 6 years. An attempt was made to create an easy-to-read report with important overviews of the "big picture", glossary of definitions, index, and further details to assist in technology transfer.
Manure On Alfalfa: Why, When, And How Much?, Monroe Rasnake
Manure On Alfalfa: Why, When, And How Much?, Monroe Rasnake
Kentucky Alfalfa and Stored Forage Conference
Manure is an excellent source of nutrients for growing crops. Its' value has been recognized for thousands of years. Before the development of chemical fertilizers, it served as the primary source of nutrients. It has decreased in importance as a nutrient source in this century and in some cases has become a disposal problem. This has led many farmers to consider using it on legume crops such as alfalfa that don't need to have nitrogen added, but will utilize it and other . nutrients in relatively large amounts. The first question to be considered, then, is why apply manure to …
Late Cretaceous Dinosaurs In Eastern Usa—A Taphonomic And Biogeographic Model Of Occurrences., David R. Schwimmer
Late Cretaceous Dinosaurs In Eastern Usa—A Taphonomic And Biogeographic Model Of Occurrences., David R. Schwimmer
Faculty Bibliography
The eastern Coastal Plains of the USA contain a Late Cretaceous dinosaur assemblage of limited taxic diversity, but with wide distribution and reasonably good abundance. The ages of specimens range from Santonian through late Maastrichtian. All Late Cretaceous eastern dinosaur specimens occur in pericontinental or marine strata, and therefore all such fossils are likely to be allochthonous. New materials and insights bear on the taphonomy of these marine occurrences, suggesting that fluvially-transported, floating carcasses, many scavenged by sharks, make up most of the eastern marine dinosaur record. There is little evidence of faunal provinciality across the entire eastern outcrop: fossil …
The Selachian Genus Sqaulicorax As Preeminent Scavengers In Upper Cretaceous Marine Sediments Of North America, David R. Schwimmer
The Selachian Genus Sqaulicorax As Preeminent Scavengers In Upper Cretaceous Marine Sediments Of North America, David R. Schwimmer
Faculty Bibliography
No abstract provided.
Jamaican Cave Vertebrates, Donald A. Mcfarlane
Jamaican Cave Vertebrates, Donald A. Mcfarlane
WM Keck Science Faculty Papers
Limestone caves in the tropics are typically associated with a more diverse assemblage of vertebrates than are caves in temperate regions. Chapman [87] for example, has reported 37 species from the caves of Gunung Mulu National Park, Sarawak, whereas Bailey [43] lists only 13 for the equally cavernicolous Guadeloupe Mountains National Park, New Mexico, USA. Twenty-eight vertebrate species have been recorded from Jamaican caves. The relative importance of the five Classes differ in these three areas as shown in Table 1 (overleaf).
Old Growth Ponderosa Pine And Western Larch Stand Structures: Influences Of Pre-1900 Fires And Fire Exclusion, United States Department Of Agriculture, Forest Service
Old Growth Ponderosa Pine And Western Larch Stand Structures: Influences Of Pre-1900 Fires And Fire Exclusion, United States Department Of Agriculture, Forest Service
Forestry
Presents detailed age structure for two western larch stands that historically experienced frequent fires. Compares age structures of eleven ponderosa pine and western larch stands representing a broad range of sites that had frequent fires. Interprets causal factors possibly linked to variations in stand age structures.
The Characterization Of An Amiid Species From The Fort Union Rock Formation Of The Early Paleocene, Alexis Penot
The Characterization Of An Amiid Species From The Fort Union Rock Formation Of The Early Paleocene, Alexis Penot
Honors Capstone Projects and Theses
No abstract provided.
Factors Affecting Atrazine Fate In North Central U.S. Soils, W. C. Koskinen, Sharon Clay
Factors Affecting Atrazine Fate In North Central U.S. Soils, W. C. Koskinen, Sharon Clay
Agronomy, Horticulture and Plant Science Faculty Publications
Atrazine (6-chloro-N-ethyl-N′-(l-methylethyl)-l,3,5-triazine-2,4-diamine) is a herbicide of the triazine family used for controlling broadleaf and some grassy weeds in corn and sorghum. Since its introduction in the late 1950s, atrazine has been a popular herbicide because it is relatively inexpensive and, in most cases, gives good season-long weed control. It can be applied pre-or postemergence and is often tank mixed with grass herbicides, such as alachlor (2-chloro-N-(2,6-diethylphenyl-N-(methoxymethyl)acetamide), metolachlor(2-chloro-N-(2-2ethyl-6-methylphenyl)-N-(2-methoxy-l-methylethyl) acetamide), butylate (S-ethyl bis(2-methylpropyl)carbamothioate), or EPTC (S-ethyl dipropylcarbamothioate), or with other broadleaf herbicides, such as dicamba (3,6-dichloro-2-methoxybenzoic …
Forest Resource Statistics For Northern Utah, 1993, United States Department Of Agriculture, Forest Service
Forest Resource Statistics For Northern Utah, 1993, United States Department Of Agriculture, Forest Service
Forestry
About 5.2 million acres, or 25 percent, of northern Utah is forested. Fifty-two percent of this forest area is capable of producing commercial wood products and is classified as timberland. Forty-eight percent is classified as woodland, primarily pinyon-juniper. The predominant forest types on the timberland are aspen, Douglas-fir, lodgepole pine, and spruce-fir. The National Forest System manages 70 percent of the timberland; 23 percent is under private ownership, and 7 percent is under other public ownership (local, State, and other Federal). Thirteen percent of the timberland is withdrawn from commercial timber production and is in a reserved status. Most reserved …
Physical, Chemical, And Biological Data For Detailed Study Of Irrigation Drainage In The San Juan Area, New Mexico, 1993-94, With Supplemental Data, 1991-95, United States Geological Survey
Physical, Chemical, And Biological Data For Detailed Study Of Irrigation Drainage In The San Juan Area, New Mexico, 1993-94, With Supplemental Data, 1991-95, United States Geological Survey
All U.S. Government Documents (Utah Regional Depository)
Investigators collected water, bottom-sediment, soil, and biological samples at more than 50 sites in the San Juan River area during 1993-94. Sample sites included (1) sites located within Department of the Interior irrigation project service areas, or areas that receive drainage from irrigation projects; (2) reference sites for comparison with irrigation project sites; and (3) sites located within the reach of the San Juan River from Navajo Dam to 10 miles downstream from the dam.
First Record Of Common Moorhen Nesting In South Dakota, William A. Meeks, Kenneth F. Higgins
First Record Of Common Moorhen Nesting In South Dakota, William A. Meeks, Kenneth F. Higgins
United States Geological Survey: Staff Publications
The common moorhen (Gallinula chloropus) is widespread in North America, but is not very abundant throughout its range (Greij 1994, Common Moorhen, Pages 145-157 in Tacha and Braun [eds.] Migratory Shore and Upland Game Bird Management in North America, Allen Press, Lawrence). In North Dakota its status is accidental (Konrad 1983, Prairie Nat. 15:144); in South Dakota it is considered a casual visitor and a probable breeding species (South Dakota Ornithologists' Union 1991, The Birds of South Dakota, Northern State University Press, Aberdeen; Peterson 1995, The Breeding Bird Atlas of South Dakota, Northern State University Press, Aberdeen).
A Land-Use And Water-Quality History Of White Rock Lake Reservoir, Dallas, Texas, Based On Paleolimnological Analyses, J. Platt Bradbury, Peter C. Van Metre
A Land-Use And Water-Quality History Of White Rock Lake Reservoir, Dallas, Texas, Based On Paleolimnological Analyses, J. Platt Bradbury, Peter C. Van Metre
United States Geological Survey: Staff Publications
White Rock Lake reservoir in Dallas, Texas contains a 150-cm sediment record of silty clay that documents land-use changes since its construction in 1912. Pollen analysis corroborates historical evidence that between 1912 and 1950 the watershed was primarily agricultural. Land disturbance by plowing coupled with strong and variable spring precipitation caused large amounts of sediment to enter the lake during this period. Diatoms were not preserved at this time probably because of low productivity compared to diatom dissolution by warm, alkaline water prior to burial in the sediments. After 1956, the watershed became progressively urbanized. Erosion decreased, land stabilized, and …
Comparison Of Source Rock Geochemistry Of Selected Rocks From The Schei Point Group And Ringnes Formation, Sverdrup Basin, Arctic Canada, P. K. Mukhopadhyay, F. Goodarzi, Michael A. Kruge, M. H. Alimi
Comparison Of Source Rock Geochemistry Of Selected Rocks From The Schei Point Group And Ringnes Formation, Sverdrup Basin, Arctic Canada, P. K. Mukhopadhyay, F. Goodarzi, Michael A. Kruge, M. H. Alimi
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
Organic-rich from the Schei Point group (middle to late Triassic in age) and the Ringnes formation (late Jurassic) from the Sverdrup basin of the Canadian arctic archipelago have been geochemically evaluated for source rock characterization. Most samples from the Schei Point group are organic-rich (> 2% TOC) and are considered as immature to mature oil-prone source rocks [kerogen types I, I-II (IIA) and II (IIA)]. These kerogen types contain abundant AOM1, AOM2 and alginite (Tasmanales, Nostocopsis, Leiosphaeridia, acritarch and dinoflagellate) with variable amounts of vitrinite, inertinite and exinite. Samples from the Ringnes formation contain dominant vitrinite and inertinite …
Soil Information Sheets For The Northern Agricultural Areas, Natural Resources Assessment Group, Agriculture Western Australia, Landcare Western Australia
Soil Information Sheets For The Northern Agricultural Areas, Natural Resources Assessment Group, Agriculture Western Australia, Landcare Western Australia
Agriculture reports
These soil information sheets are produced for farmers in the Northern Wheatbelt. Each sheet summaries information on the particular soil's characteristic properties and associated land use suitability and management. A photograph of a representative profile is provided for each soil. Technical terms are defined in the glossary. Information is presented under the following headings: Soil series and group, occurrence, native vegetation, soil profile description, characteristic soil properties, soil classification (Australian Soil Classification and Northcote Principal Profile Form).
Separation And Artificial Maturation Of Macerals From Type Ii Kerogen, Michael A. Kruge, Patrick Landais, David F. Bensley, B Artur Stankiewicz, Marcel Elie, Olivier Ruau
Separation And Artificial Maturation Of Macerals From Type Ii Kerogen, Michael A. Kruge, Patrick Landais, David F. Bensley, B Artur Stankiewicz, Marcel Elie, Olivier Ruau
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
Immature Type II kerogen (HI= 660 mg/g) from the Lower Toarcian of the Paris Basin was separated into an alginite concentrate (HI = 952 mg/g) and an amorphous organic matter (AOM) concentrate (HI = 573 mg/g) by density centrifugation. The flash pyrolyzate of the alginite is characterized by high relative concentrations of several series of n-alkanones and n-alkenones (including mid-chain alkyl ketones), in addition to n-alkanes, n-alk-1-enes and n-alkadienes. To our knowledge, this Toarcian alginite is the oldest example of marine organic matter whose pyrolyzate contains mid-chain alkanones in such high relative concentrations. In sharp …
Soil Management For Intensive Grazing, Kenneth L. Wells, Charles T. Dougherty
Soil Management For Intensive Grazing, Kenneth L. Wells, Charles T. Dougherty
Soil Science News and Views
Recycling of plant nutrients is of major concern in managing paddocks in pasturefields for intensive grazing. Redistribution of nutrients present in fecal and urine deposits is an important issue in growing climatically and seasonally-adapted forage species and for efficient conversion of herbage into animal products while adding to the sustainability of the system. Some of the questions that arise in managing soils for intensive grazing are discussed below.
Fresh-Water Aquifer In The Knox Group (Cambrian–Ordovician) Of Central Kentucky, James A. Kipp
Fresh-Water Aquifer In The Knox Group (Cambrian–Ordovician) Of Central Kentucky, James A. Kipp
Report of Investigations--KGS
Fresh water can be found in Cambrian and Ordovician carbonate rocks of the Knox Group in central Kentucky. The top of the aquifer is as much as 300 ft above mean sea level (m.s.l.) on the crest of the Cincinnati Arch, but descends off the flanks of the arch. Water is normally found in the upper 100 to 250 ft of the Knox, primarily in secondary porosity apparently associated with the unconformity at the top of the unit. Knox wells commonly exceed 750 ft in total depth, but because the aquifer is artesian, water rises to an elevation of about …
Fluxes Of Copper-Complexing Ligands From Estuarine Sediments, Stephen A. Skrabal, John R. Donat, David J. Burdige
Fluxes Of Copper-Complexing Ligands From Estuarine Sediments, Stephen A. Skrabal, John R. Donat, David J. Burdige
OES Faculty Publications
Most studies of the organic complexation of Cu in natural waters have focused on distributions and processes in the water column, where a significant fraction of Cu-complexing ligands may be biologically produced. We present direct evidence for a flux of Cu-complexing ligands from estuarine sediments, demonstrating that sediments are a significant, yet previously unrecognized source of the ligands. Fluxes of Cu-complexing ligands from Chesapeake Bay sediments range from 300 to 1,200 nmol m-2 d-1, exceeding fluxes of total dissolved Cu by 3->40-fold, suggesting that any Cu fluxing from the sediments is likely to be organically complexed. …
Regulation Of Algal Blooms In Antarctic Shelf Waters By The Release Of Iron From Melting Sea Ice, Peter N. Sedwick, Giacomo R. Ditullio
Regulation Of Algal Blooms In Antarctic Shelf Waters By The Release Of Iron From Melting Sea Ice, Peter N. Sedwick, Giacomo R. Ditullio
OES Faculty Publications
During summer 1995-96, we measured iron in the water column and conducted iron-enrichment bottle-incubation experiments at a station in the central Ross Sea (76°30'S, 170°40'W), first, in the presence of melting sea ice, and 17 days later, in ice-free conditions. We observed a striking temporal change in mixed-layer dissolved iron concentrations at this station, from 0.72-2.3 nM with sea ice present, to 0.16-0.17 nM in ice-free conditions. These changes were accompanied doubling of algal (diatom) biomass. Our incubation experiments suggest that conditions were iron-replete in the presence of sea ice, and iron-deficient in the absence of sea ice. We surmise …
Vegetative Filter Strip Removal Of Metals In Runoff From Poultry Litter-Amended Fescuegrass Plots, Dwayne R. Edwards, P. A. Moore Jr., Tommy C. Daniel, Puneet Srivastava, D. J. Nichols
Vegetative Filter Strip Removal Of Metals In Runoff From Poultry Litter-Amended Fescuegrass Plots, Dwayne R. Edwards, P. A. Moore Jr., Tommy C. Daniel, Puneet Srivastava, D. J. Nichols
Biosystems and Agricultural Engineering Faculty Publications
Runoff from land areas amended with poultry (Gallus gallus domesticus) manure can contain elevated concentrations of metals such as Cu, Fe, and Zn. Vegetative filter strips (VFS) can reduce runoff concentrations of animal manure components, but reported studies have typically focused on nutrients and solids rather than metals. This experiment assessed the impact of VFS length (0 to 12 m) on concentrations and mass losses of Cu, Fe, K, Na, Ni, and Zn in runoff from fescuegrass (Festuca arundinacea Schreb.) plots (1.5 m wide × 6 and 12 m long) treated with poultry litter. The runoff was produced from simulated …
Focus Catchments : A New Approach To Salinity Research : National Dryland Salinity Program, Steve Porritt
Focus Catchments : A New Approach To Salinity Research : National Dryland Salinity Program, Steve Porritt
Journal of the Department of Agriculture, Western Australia, Series 4
Dry/and salinity is a major threat to the resource base of many rural industries around Australia. More than 1.8 million hectares of once productive land are affected by salinity, with a further 1.6 million hectares at risk in the next 15 to 25 years in Western Australia alone. Much of the past Commonwealth and State expenditure on salinity programs and activities has been poorly targeted and coordinated. In view of this, a national dry/and salinity program that supports specific State salinity management programs has been established jointly between the Commonwealth and State government agencies.
The Upper Kent River Catchment is …
Glacial Deposits, Vol. 25, 1996-1997, Department Of Geography-Geology
Glacial Deposits, Vol. 25, 1996-1997, Department Of Geography-Geology
Glacial Deposits
Newsletter of the Department of Geography-Geology
Herbicides And Their Metabolites In Rainfall: Origin, Transport, And Deposition Patterns Across The Midwestern And Northeastern United States, 1990-1991, Donald Goolsby, E. Michael Thurman, Michael Pomes, Michael Meyer, William Battaglin
Herbicides And Their Metabolites In Rainfall: Origin, Transport, And Deposition Patterns Across The Midwestern And Northeastern United States, 1990-1991, Donald Goolsby, E. Michael Thurman, Michael Pomes, Michael Meyer, William Battaglin
United States Geological Survey: Staff Publications
Herbicides were detected in rainfall throughout the midwestern and northeastern United States during late spring and summer of 1990 and 1991. Herbicide concentrations exhibited distinct geographic and seasonal patterns. The highest concentrations occurred in midwestern cornbelt states following herbicide application to cropland. Volume-weighted concentrations of 0.2-0.4 μg/L for atrazine and alachlor were typical in this area during mid-April through mid-July, and weighted concentrations as large as 0.6- 0.9 μg/L occurred at several sites. Concentrations of 1-3 μg/L were measured in a few individual samples. Atrazine was detected most often followed by alachlor, deethylatrazine, metolachlor, cyanazine, and deisopropylatrazine. The high ratio …
Climatic Fluctuations And Tropical Troglobitic Evolution, Pedro Gnaspini
Climatic Fluctuations And Tropical Troglobitic Evolution, Pedro Gnaspini
International Journal of Speleology
No abstract provided.
The Hawaiian Cave Planthoppers (Homoptera: Fulgoroidea: Cixiidae) - A Model For Rapid Subterranean Speciation?, Hannelore Hoch
The Hawaiian Cave Planthoppers (Homoptera: Fulgoroidea: Cixiidae) - A Model For Rapid Subterranean Speciation?, Hannelore Hoch
International Journal of Speleology
After the successful colonization of a single ancestral species in the Hawaiian Islands, planthoppers of the cixiid genus Oliarus underwent intensive adaptive radiation resulting in 80 described endemic species. Oliarus habitats range from montaneous rain forests to dry coastal biotopes and subterranean environments. At least 7 independant evolutionary lines represented by different species have adapted to lava tubes on Molokai (1), Maui (3), and Hawaii Island (3). Behavioral and morphological studies on one of these evolutionary lines on Hawaii Island, the blind, flight- and pigmentless Oliarus polyphentus have provided evidence for reproductive isolation between allopatric populations which may in fact …