Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

Utah State University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 5431 - 5460 of 7341

Full-Text Articles in Physical Sciences and Mathematics

Evaluation Of Volatilization Of Hazardous Constituents At Hazardous Waste Land Treatment Sites, R. Ryan Dupont, J. A. Reineman Jan 1986

Evaluation Of Volatilization Of Hazardous Constituents At Hazardous Waste Land Treatment Sites, R. Ryan Dupont, J. A. Reineman

Reports

The magnitude and extent of volatile organic emissions from hazardous waste land treatment systems were evaluated in laboratory and field studies using complex petroleum refining hazardous wastes. Laboratory experiments were conducted using two soils and a intert construction sand to investigate the emission flux rates of seven volatile constituents, i.e., benzene, toluene, ethylbenzene, p-, m-, o-xylene, and naphthalene, from API Separatory Sludge and Slop Oil Emulsion Solids wastes in column and flask laboratory units as a function of waste application rate, application method (surface versus subsurface), soil type and soil physical characteristics. Field experiemtns were conducted at an active petroleum …

Go to article

Infrared Surface-Wave Interferometry On W(100), L. M. Hanssen, D. Mark Riffe, A. J. Sievers Jan 1986

Infrared Surface-Wave Interferometry On W(100), L. M. Hanssen, D. Mark Riffe, A. J. Sievers

All Physics Faculty Publications

An IR grating on a clean W(100) surface is shown to generate both homogeneous and inhomogeneous surface electromagnetic waves. An observed interference between these two components, which can be described in terms of a two-beam interferometer with variable arm amplitude and fixed optical path, is used to measure the plasma frequency accurately in the IR.

Go to article

Problems With Deducing Ionospheric Plasma Convection Patterns, Jan Josef Sojka, Robert W. Schunk Jan 1986

Problems With Deducing Ionospheric Plasma Convection Patterns, Jan Josef Sojka, Robert W. Schunk

All Physics Faculty Publications

It is well-known that convection electric fields have an important effect on the ionosphere-thermosphere system at high latitudes and that a quantitative understanding of their effect requires a knowledge of the plasma convection pattern. Consequently, convection electric fields have been measured by a variety of techniques, including satellite, rocket, and balloon-borne probes, optical tracking of ionized barium clouds, incoherent scatter observations of drifting F region plasma, and coherent scatter observations of drifting E region irregularities. Since all of these measurement techniques provide information on only a limited spatial region at any time, the construction of the overall convection pattern requires …

Go to article

Comparison Of Simultaneous Chatanika And Millstone Hill Observations With Ionospheric Model Predictions, C. E. Rasmussen, Robert W. Schunk, Jan Josef Sojka, Vincent B. Wickwar, O. De La Beaujardiere, J. Foster, J. Holt, D. S. Evans, E. Nielsen Jan 1986

Comparison Of Simultaneous Chatanika And Millstone Hill Observations With Ionospheric Model Predictions, C. E. Rasmussen, Robert W. Schunk, Jan Josef Sojka, Vincent B. Wickwar, O. De La Beaujardiere, J. Foster, J. Holt, D. S. Evans, E. Nielsen

All Physics Faculty Publications

As part of the MITHRAS program, the Chatanika and Millstone Hill incoherent-scatter radars made coordinated observations of the polar ionosphere on June 27 and 28, 1981. We compare these data with predictions made by a high-latitude ionospheric model. Qualitatively, the same features are evident in both the model and the radar data: fairly constant densities on the dayside with a mid-latitude trough forming poleward of 65 degrees around 1900 MLT (magnetic local time). This trough is seen to extend equatorward with increasing MLT, such that the minimum densities occurring in the trough appear just after midnight around 60 degrees dipole …

Go to article

An Interplanetary Magnetic Field Dependent Model Of The Ionospheric Convection Electric Field, Jan Josef Sojka, C. E. Rasmussen, Robert W. Schunk Jan 1986

An Interplanetary Magnetic Field Dependent Model Of The Ionospheric Convection Electric Field, Jan Josef Sojka, C. E. Rasmussen, Robert W. Schunk

All Physics Faculty Publications

A mathematical model of the magnetospheric electric field imposed upon the ionosphere is presented. The model provides an interplanetary magnetic field (IMF) dependent description of the magnetospheric electric field at ionospheric altitudes for global ionospheric and thermospheric modelers. Although many theoretical and empirical ionospheric convection models have been published, none give both a quantitative and a general Kp, IMF (Bx , By , Bz) dependent description. The need for such a model is particularly pressing with the success of the Dynamic Explorer (DE) mission. As a result of this mission, extensive data sets of …

Go to article

Formation Kinetics Of Thermal Donors In Silicon, J T. Borenstein, J W. Corbett, David Peak Jan 1986

Formation Kinetics Of Thermal Donors In Silicon, J T. Borenstein, J W. Corbett, David Peak

All Physics Faculty Publications

The kinetics of thermal donor formation in Czochralski-silicon at ca. 450° C are explained by a simple model based on the work of Suezawa and Sumino which derives forward and reverse reaction rates for each electrically active species from the general features of the infrared electronic absorption spectra. The model, which is independent of the chemical nature of the thermal donor core, assumes that all thermal donors beyond the first donor species are chemically stable at the donor formation temperature, and approximates the reactions for species smaller than the first thermal donor as being in chemical equilibrium. The model is …

Go to article

Crossover From Contact Propagation To Chemical Propagation In First-Passage Percolation, A. R. Kerstein, Boyd F. Edwards Jan 1986

Crossover From Contact Propagation To Chemical Propagation In First-Passage Percolation, A. R. Kerstein, Boyd F. Edwards

All Physics Faculty Publications

On lattices whose bonds are assigned time delays from a bimodal distribution with modes at b and a≫b whose relative weights are p and 1-p, the dependence of the first-passage velocity v on p is investigated by means of scaling arguments and computations. As p increases, v exhibits a sharp rise near the percolation threshold due to a crossover from the contact-propagation regime, in which slow-bond crossings are rate limiting, to the chemical-propagation regime, in which the tortuosity of the shortest path through the fast-bond network is rate limiting. Previous analyses of criticality in the limit a/b→∞ are extended by …

Go to article

A Theoretical Study Of The Production And Decay Of Localized Electron Density Enhancements In The Polar Ionosphere, Jan Josef Sojka, Robert W. Schunk Jan 1986

A Theoretical Study Of The Production And Decay Of Localized Electron Density Enhancements In The Polar Ionosphere, Jan Josef Sojka, Robert W. Schunk

All Physics Faculty Publications

The origins, transport, and decay of large-scale (≳ 10 km) F region density irregularities were theoretically studied using a high-latitude time dependent ionospheric model. Such density irregularities (blobs) have been found both in the polar cap and the auroral zone. The model study, which focuses on blobs being produced by auroral precipitation, shows that the observed energy fluxes can readily account for the blob densities if a plasma flux tube is exposed to the precipitation for 5-10 min. Once the flux tube is transported away from the source, the F region density profile recovers its shape on a time scale …

Go to article

Effects Of Different Convection Models Upon The High-Latitude Ionosphere, C. E. Rasmussen, Robert W. Schunk, Jan Josef Sojka Jan 1986

Effects Of Different Convection Models Upon The High-Latitude Ionosphere, C. E. Rasmussen, Robert W. Schunk, Jan Josef Sojka

All Physics Faculty Publications

It is well known that convection electric fields have an important effect on the ionosphere at high latitudes and that a quantitative understanding of their effect requires a knowledge of plasma convection over the entire high-latitude region. Two empirical models of plasma convection that have been proposed for use in studying the ionosphere are the Volland and Heelis models. Both of these models provide a similar description of two-celled ionospheric convection, but they differ in several ways, in particular, in the manner in which plasma flows over the central polar cap and near the polar cap boundary. In order to …

Go to article

Theoretical Study Of The Electron Temperature In The High-Latitude Ionosphere For Solar Maximum And Winter Conditions, Robert W. Schunk, Jan Josef Sojka, M. D. Bowline Jan 1986

Theoretical Study Of The Electron Temperature In The High-Latitude Ionosphere For Solar Maximum And Winter Conditions, Robert W. Schunk, Jan Josef Sojka, M. D. Bowline

All Physics Faculty Publications

The electron temperature (Te) variation in the high-latitude ionosphere at altitudes between 120 and 800 km has been modeled for solar maximum, winter solstice, and strong magnetic activity conditions. The calculated electron temperatures are consistent with the plasma densities and ion temperatures computed from a time-dependent ionospheric model. Heating rates for both solar EUV and auroral precipitation were included. In general, the predicted UT variation of the electron temperature that results from the displacement between the magnetic and geographic poles is only a few hundred degrees. However, in sunlit trough regions, Te hot spots develop, and …

Go to article

Catastrophic Damage From Dam Break Floods, L. Douglas Jemes, Al-Hassan Sumani, Melanie L. Bengston Jan 1986

Catastrophic Damage From Dam Break Floods, L. Douglas Jemes, Al-Hassan Sumani, Melanie L. Bengston

Reports

No abstract provided.

Go to article

National Surface Water Survey: National Stream Survey Phase I--Pilot Survey, J. J. Messer, C. W. Ariss, R. Baker, S. K. Drouse, K. N. Eshleman, P. R. Kaufmann, R. A. Linthurst, J. M. Omernik, W. S. Overton, M. J. Sale, R. D. Schonbrod, S. M. Stambaugh, J. R. Tuschall Jr. Jan 1986

National Surface Water Survey: National Stream Survey Phase I--Pilot Survey, J. J. Messer, C. W. Ariss, R. Baker, S. K. Drouse, K. N. Eshleman, P. R. Kaufmann, R. A. Linthurst, J. M. Omernik, W. S. Overton, M. J. Sale, R. D. Schonbrod, S. M. Stambaugh, J. R. Tuschall Jr.

Reports

No abstract provided.

Go to article

Economic Evaluation Of Conservation Concepts For Municipal Water Systems, Trevor C. Hughes, Rangesan Narayanan, Mac Mckee, A. Bruce Bishop, Robert Leconte, Sumani Al-Hassan Jan 1986

Economic Evaluation Of Conservation Concepts For Municipal Water Systems, Trevor C. Hughes, Rangesan Narayanan, Mac Mckee, A. Bruce Bishop, Robert Leconte, Sumani Al-Hassan

Reports

Five concepts for conservation of municipal water supply are analyzed from an economic efficiency perspectice. They include: 1) seasonal pricing (for reduction of peak period water use), 2) dual water systems (separate high quality drinking water and untreated outdoor irrigation systems), 3) imported water transmission facility capacity optimization, 4) flow restricting devices, and 5) short-term rationing concepts. Optimization models, including generalized model generators, were developed for analysis of the first three concepts and demonstrated by applications to cities in Utah. The flow restricting device and short-term rationsing concept analyses applied approaches taken from the literature to example sites in Utah. …

Go to article

Water Quality Management Studies For Water Resources Development In The Bear River Basin, Darwin L. Sorensen, Craig Caupp, William J. Grenney, Steve Eberl, Jay J. Messer, Phillip Ludvigsen, Charles W. Ariss Jan 1986

Water Quality Management Studies For Water Resources Development In The Bear River Basin, Darwin L. Sorensen, Craig Caupp, William J. Grenney, Steve Eberl, Jay J. Messer, Phillip Ludvigsen, Charles W. Ariss

Reports

Summary: The quality of water that develops in the proposed reservoirs of the Upper Bear River Storage Project will determine the possible uses of the water. Previous studies of water quality in the Bear River and its tributaries have reported water quality problems relating to nitrate ion, sanitary indicator bacteria, suspended solids, and phosphorus concentrations. Most point sources of water pollution inthe basin have been eliminated or improved in quality, but nonpoint sources of pollution continue to degrade the quality of the Bear River. Concentrations of phosphours have been sufficiently high to encourage dense algal growth and create eutrophic conditions …

Go to article

'Hobble Creek' - A Superior Selection Of Low-Elevation Mountain Big Sagebrush, United States Department Of Agriculture, Forest Service Jan 1986

'Hobble Creek' - A Superior Selection Of Low-Elevation Mountain Big Sagebrush, United States Department Of Agriculture, Forest Service

Forestry

This is the foundation document for the release of the 'Hobble Creek' selection of big sagebrush. It is a low-elevation mountain big sagebrush (Artemisia tridentata ssp. vaseyana). 'Hobble Creek' is needed to increase the nutrient content of winter diets of mule deer (Odocoileus hemionus hemionus) and domestic sheep (Ovis aries). This sagebrush exceeds the typical winter forage values in amount of energy-producing compounds, crude protein, phosphorus, and carotene. Of the 186 big sagebrush selections tested. 'Hobble Creek' is the most preferred by wintering mule deer and ranks high in preference by wintering domestic sheep. 'Hobble Creek' does not contain substances …

Go to article

The Influence Of Viewing Angle On Elk Hiding Cover In Young Timber Stands, United States Department Of Agriculture, Forest Service Jan 1986

The Influence Of Viewing Angle On Elk Hiding Cover In Young Timber Stands, United States Department Of Agriculture, Forest Service

Forestry

Young timber stands, even when providing 100 percent visual concealment for elk when viewed on a horizontal plane, may provide 50 percent or less cover when viewed from an opposing slope at an elevated viewing angle. The higher the viewing angle, the greater the relative cover loss. In a simple linear model, viewing angle explained 52 percent of the variation in hiding cover values. Slightly more variation was accounted for when the data were stratified by tree height. On the average, for a 10-degree elevation in viewing angle, hiding cover decreased by 10 percent. The cover loss relationship was most …

Go to article

Proceedings -- National Wilderness Research Conference: Current Research, United States Department Of Agriculture, Forest Service Jan 1986

Proceedings -- National Wilderness Research Conference: Current Research, United States Department Of Agriculture, Forest Service

Forestry

Includes more than 70 reports of current wilderness research. Papers are organized around nine topics: wilderness resource research, including natural fire, air quality, impacts to soil and vegetation, fish and wildlife, and water; and wilderness user research related to recreational use and user characteristics, attitudes and behavior, benefits, and management concepts and tools.

Go to article

The Guy Smith Interviews: Rationale For Concepts In Soil Taxonomy, U.S. Soil Conservation Service Jan 1986

The Guy Smith Interviews: Rationale For Concepts In Soil Taxonomy, U.S. Soil Conservation Service

Natural Resources-Planning, Management, and Conservation

Interviews with Guy D. Smith, former director of the Soil Survey Investigations Division of the Soil Conservation Service and distinguished international soil scientist.

Go to article

Modeling Moisture Content Of Fine Dead Wildland Fuels: Input To The Behave Fire Prediction System, United States Department Of Agriculture, Forest Service Jan 1986

Modeling Moisture Content Of Fine Dead Wildland Fuels: Input To The Behave Fire Prediction System, United States Department Of Agriculture, Forest Service

Wildfires

A method for predicting the time-dependent nature of fine fuel moisture is badly needed to support fire behavior prediction systems used in fire management. Of the models available, none met all the requirements of the BEHAVE fire behavior prediction system. The Canadian Fire Fuel Moisture Code (FFMC) came closest to meeting our needs and was selected as a base model. Improvements to the FFMC were concentrated on providing a means of accounting for annual and diurnal variation due to solar heating of woody fuels. This was necessary because the FFMC was developed for fuels located within forest stands, a generally …

Go to article

Visitor Attitudes Toward Wilderness Fire Management Policy -- 1971-84, United States Department Of Agriculture, Forest Service Jan 1986

Visitor Attitudes Toward Wilderness Fire Management Policy -- 1971-84, United States Department Of Agriculture, Forest Service

Wildfires

The historical role of naturally occurring fire in shaping the character of many American landscapes has become an accepted ecological principle. Prior to the coming of the Europeans, natural fires had a major influence in producing a variety of vegetational mosaics. Fire suppression policies of the 20th century, however, significantly changed the evolution of many landscapes compared to what would have occurred had natural fires been allowed to continue. Although natural fires can no longer be allowed to burn in many places because of resource values or danger to the public, such fires may be permitted in many wildernesses and …

Go to article

Flood Insurance Study, City Of Richfield, Utah, Sevier County, Federal Emergency Management Agency Jan 1986

Flood Insurance Study, City Of Richfield, Utah, Sevier County, Federal Emergency Management Agency

All U.S. Government Documents (Utah Regional Depository)

This Flood Insurance Study investigates the existence and severity of flood hazards in the City of Richfield, Sevier County, Utah, and aids in the administration of the National Flood Insurance Act of 1968 and the Flood Disaster Protection Act of 1973. This study has developed flood risk data for various areas of the community that will be used to establish actuarial flood insurance rates and assist the community in its efforts to promote sound flood plain management. Minimum flood plain management requirements for participation in the National Flood Insurance Program (NFIP) are set forth in the Code of Federal Regulations …

Go to article

Flood Insurance Study, City Of Salina, Utah, Sevier County, Federal Emergency Management Agency Jan 1986

Flood Insurance Study, City Of Salina, Utah, Sevier County, Federal Emergency Management Agency

All U.S. Government Documents (Utah Regional Depository)

This Flood Insurance Study investigates the existence and severity of flood hazards in the City of Salina, Sevier County, Utah, and aids in the administration of the National Flood Insurance Act of 1968 and the Flood Disaster Protection Act of 1973. This study has developed flood risk data for various areas of the community that will be used to establish actuarial flood insurance rates and assist the community in its efforts to promote sound flood plain management. Minimum flood plain management requirements for participation in the National Flood Insurance Program (NFIP) are set forth in the Code of Federal Regulations …

Go to article

The Seedskadee Project: Remote Sensing In Non-Site Archeology, Dwight L. Drager, Arthur K. Ireland, National Park Service, Bureau Of Reclamation, United Sates Department Of The Interior Jan 1986

The Seedskadee Project: Remote Sensing In Non-Site Archeology, Dwight L. Drager, Arthur K. Ireland, National Park Service, Bureau Of Reclamation, United Sates Department Of The Interior

All U.S. Government Documents (Utah Regional Depository)

The project area includes some 185,000 acres of land along the banks of the Green River below the Fontenelle Dam in southwestern Wyoming. The Statement of Work calls for 1) a Class I Cultural Resources Survey and Remote Sensing Survey to assess the general nature of the resources, 2) the preparation of a predictive study design based on available information, and 3) a ground truth survey on a small sample of the project area. This proposal discusses the methods that the Branch of Remote Sensing of the Division of Cultural Research of the Southwest Cultural Resources Center of the National …

Go to article

Correction Of The Basis Set Superposition Error In Scf And Mp2 Interaction Energies. The Water Dimer, M. M. Szczesniak, Steve Scheiner Jan 1986

Correction Of The Basis Set Superposition Error In Scf And Mp2 Interaction Energies. The Water Dimer, M. M. Szczesniak, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

There has been some discussion concerning whether basis set superposition error is more correctly evaluated using the full set of ghost orbitals of the partner molecule or some subset thereof. A formal treatment is presented, arguing that the full set is required at the Møller–Plesset level. Numerical support for this position is provided by calculation of the interaction energy between a pair of water molecules, using a series of moderate sized basis sets ranging from 6‐31G∗∗ to the [432/21] contraction suggested by Clementi and Habitz. These energies, at both the SCF and MP2 levels, behave erratically with respect to changes …

Go to article

Chemical Quality Of Ground Water In Salt Lake Valley, Utah, 1969-85, United States Geological Survey Jan 1986

Chemical Quality Of Ground Water In Salt Lake Valley, Utah, 1969-85, United States Geological Survey

All U.S. Government Documents (Utah Regional Depository)

During 1979-84, 35 wells completed in the principal aquifer in the Salt Lake Valley, Utah, that had been sampled during 1962-67 were resampled to determine if water-quality changes had occurred. The dissolved-solids concentration of the water from 13 of the wells has increased by more than 10 percent since 1962-67.

Go to article

Potential Geologic Hazards Near The Thistle Landslide, Utah County, Utah, United States Geological Survey Jan 1986

Potential Geologic Hazards Near The Thistle Landslide, Utah County, Utah, United States Geological Survey

All U.S. Government Documents (Utah Regional Depository)

In mid-April, 1983, an old landslide near Thistle, Utah, began to move, and within days had blocked Spanish Fork Canyon. As the slide's movement continued, construction crews gradually converted the toe of the slide into an earth-filled dam--Thistle dam--that impounded northwest-flowing Spanish Fork River. The resultant reservoir, known as Thistle Lake, was subsequently drained because of uncertainty about the stability of the dam. Recently, officials of Utah County have explored various alternatives for a water-retention structure in the area, including utilization of Thistle dam. The Thistle Slide Committee, established by the State of Utah to evaluate the suitability of using …

Go to article

The Potential Energy Surface Of (Nh3)2, Z. Latajka, Steve Scheiner Jan 1986

The Potential Energy Surface Of (Nh3)2, Z. Latajka, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Ab initio calculations at the SCF and correlated levels are carried out to characterize the potential energy surface of the NH3 dimer. The two basis sets used are 4‐31G∗ and a larger one containing two sets of d‐functions on N centers, 6‐31G∗∗ (1p, 2d). The only minimum occurring on the surface is a cyclic C2h structure in which the two H‐bonding protons are displaced 42° from the N‐‐N axis. The surface contains a very shallow valley along the direction leading from this geometry to a single linear H bond although …

Go to article

Feasibility Of Incorporating Aquaculture, Solar Pond Energy, And Mineral Extraction Technologies To Control Localized Sources Of Salinity In River Systems, J. Paul Riley Jan 1986

Feasibility Of Incorporating Aquaculture, Solar Pond Energy, And Mineral Extraction Technologies To Control Localized Sources Of Salinity In River Systems, J. Paul Riley

Reports

Salinity poses a serious and continuing problem to the full utilization of water resources in many river basins of western U.S. A variety of management measures have been employed to mitigate the damaging effects of salinity on agricultural crops as well as on municipal and industrial uses of water. The Colorado River Basin Salinity Control Act illustrates the logic of addressing the problem on a basin wide basis under a strategy that give priority to those localized sources of salinity that contribute disproportionately large amounts of salt to the system. It remains then to devise control measures specific to each …

Go to article

Appendices: Water Quality Management In Utah Mountain Watersheds, Keith R. Kimball, E. Joe Middlebrooks Jan 1986

Appendices: Water Quality Management In Utah Mountain Watersheds, Keith R. Kimball, E. Joe Middlebrooks

Reports

No abstract provided.

Go to article

Water Quality Management In Utah Mountain Watersheds, Keith R. Kimball, E. Joe Middlebrooks Jan 1986

Water Quality Management In Utah Mountain Watersheds, Keith R. Kimball, E. Joe Middlebrooks

Reports

What Quality Management in Utah Mountain Streams: Several years of thorough monitoring of water quality parameters in Little Cottonwood Creek in Salt Lake County, Utah, measured the natural levels of the major water constituents, spotted significant (largely nonpoint) pollution sources, identified the pollutants deserving primary attention, and suggested the approaches to land and water management for pollution control in a mountain watershed used primarily for recreation purposes. Bacterial pollution is greater at night than during the day, on weekends than on week days, and in the summer than in the winter. Mineral content is of natural origin and largely explained …

Go to article

First Prev Next Last