Digital Commons Network^™

Tree Diameter Measurements At English And Metric Standard Heights: A Comparison, United States Department Of Agriculture, Forest Service

Forestry

The impact of measuring trees at 1.3 m versus 1.37 m heights above ground line was analyzed. The results indicate that the difference in diameter measurement taken at the two points averages around 1 percent. An equation for converting from English diameter at breast height to the metric equivalent of 1.3 m is presented.

Effect Of Small Aspen Clearcuts On Water Yield And Water Quality, United States Department Of Agriculture, Forest Service

Forestry

Streamflow and water quality were monitored in a paired watershed study involving the removal of 20 percent of the aspen (on 13 percent of the area) in five small clearcuts from a 217-acre (88-ha) catchment. There were no significant changes in peak flow, timing, or annual yield during the 4 years of posttreatment monitoring. Significant changes in pH, calcium, magnesium, and nitrates in the snowmelt streamflow from ephemeral subdrainages occurred the second year after cutting. At least some of the differences were attributed to the chemistry of the 1976-77 snowfall, which was also significantly different from snow sampled in the …

Development Of Structured Regression Hypotheses Interactive/Descriptive Geometry Through Five Dimensions, United States Department Of Agriculture, Forest Service

Miscellaney

Regression hypotheses admitted to statistical evaluation should, of course, be germain to relations between the variables considered. This constraint is easily violated with the screening of arbitrarily adopted sets of hypotheses. Sequential polynomials in additive models, for example, may include components that are not commensurate with expectation (prior knowledge) and may not include those that are (e.g., unique interaction terms) and, since the analytical results from the screening of meaningless hypotheses may themselves be meaningless, there is substantial incentive for serious preanalysis consideration of the hypotheses to be evaluated.

The Polar Ionosphere: Editorial, Vincent B. Wickwar, J W. Meriwether Jr.

All Physics Faculty Publications

Editorial

On The Reversal From “Sunward” To “Antisunward” Plasma Convection In The Dayside High Latitude Ionosphere, T S. Jorgensen, E Friis-Christensen, Vincent B. Wickwar, J D. Kelly, C R. Clauer, P M. Banks

All Physics Faculty Publications

Preliminary observations of dayside high latitude ionospheric plasma convection with the Sondrestrom incoherent‐scatter radar indicate that plasma can be observed to enter the polar cap region through rotational reversals at most local times between dawn and dusk and not just in a narrow region around noon. Assuming that rotational reversals are signatures of a solar wind‐magnetosphere interaction which drives magnetospheric convection, the observations indicate that this interaction occurs over a longitudinally wide area of the dayside magnetosphere. The observations also show that the distribution of F‐region plasma in the polar cap is dependent on ionization sources anywhere between dawn and …

Electron Detectors Used For Imaging In The Scanning Electron Microscope, V. N. E. Robinson

Scanning Electron Microscopy

Electron detectors used for imaging in the scanning electron microscope include those which detect secondary electrons, various portions of the backscattered electron signal, and the residual specimen current. The use of a different detector will often produce a different image of the same specimen. The information contained in these images depends upon the signal detected and the properties of the detector used. The choice of detector to be used depends upon the information desired.

Magnetic Electron Lenses, Wolfgang Dieter Riecke

Scanning Electron Microscopy

The electron optical properties of magnetic lenses are determined by the ratio S/D of gap width S to bore diameter D, by the actual size of the gap and by the lens strength NJ√U*. Objective lenses of particularly small aberrations are obtained if the specimen is positioned close to the center of the gap and if the width of the gap is made as small as possible. For projector lenses the best performance results if the lens is employed at its minimum focal length. Another aspect important for high resolution lenses is that a stigmator is available for the correction …

Progress In The Theory Of Electron-Beam Deflection, E. F. Ritz Jr.

Scanning Electron Microscopy

Analysis, simulation, and design of electron-beam-deflection systems are reviewed in light of the current state of theoretical understanding. A brief review of the physical principles is followed by a detailed discussion of electrostatic, magnetostatic, mixed-field, traveling-wave, and scan-expansion systems. Each methodology is examined from a triple perspective: calculation of electromagnetic fields, calculation of electron trajectories, and calculation of the ensemble of trajectories forming the beam. Applications discussed include deflectors for television displays, lithography, scanning microscopes, and CRT oscillography. Developments of the last ten years are stressed, thereby supplementing and updating the author's previous review on this subject.

In field calculation, …

Magnetic Electron Lenses Ii, T. Mulvey

Scanning Electron Microscopy

Conventional magnetic electron lenses have evolved to their present highly developed state under the pressure of meeting the exacting requirements of high resolution electron microscopy. More recently, however, the desire to extract quantitative analytical information from the specimen has led to significant changes in the design of electron optical systems. The introduction of efficient lanthanum hexaboride cathodes and high beam current field-emission sources has strengthened this tendency. In addition, more complex lens systems than previously envisaged are now possible since microprocessors can be employed to assist in the rapid and reliable readjustment of the lens system, including the extensive alignment …

Synthesis Of Electron Lenses, M. Szilagyi

Scanning Electron Microscopy

This paper is a review of different approaches to one of the most ambitious goals of Electron and Ion Optics: to produce elements and systems with prescribed first-order properties and minimal aberrations. Synthesis of such elements is usually done in two steps: the first is a search for a field distribution with the given properties and the second is the reconstruction of electrodes (pole pieces) that would produce this field distribution. The first problem can be solved by the use of different techniques: Calculus of Variations, Dynamic Programming or Function Minimization. The second one is more complicated and requires a …

Very High Electron Temperatures In The Daytime F-Region At Sondrestrom, W Kofman, Vincent B. Wickwar

All Physics Faculty Publications

Sondrestrom observations show that a characteristic F‐region signature of the interaction between the magnetosphere and ionosphere is a narrow band of elevated electron temperatures. Its location is associated with the ion convection reversal in the morning and evening convection cells. Typically, near 500 km altitude, the temperature is 3500 to 4000 K. However, on 24 April 1983, a geomagnetically very active day with Kp values of 6‐ during the period of interest, the electron temperature reached 6000 K in the afternoon convection reversal. The ion velocities were between 1 and 2 km/s on both sides of the reversal. There was …

Ionospheric Currents And F-Region Plasma Boundaries Near The Dayside Cusp, S Vennerstrom, E Friis-Christensen, T S. Jorgensen, C. E. Rasmussen, C R. Clauer, Vincent B. Wickwar

All Physics Faculty Publications

Observational evidence of the location of a dayside high‐latitude ionospheric current (DPY current) with respect to the different regimes of the high‐latitude magnetosphere is obtained by analyzing data from the magnetometer chain along the west coast of Greenland in conjunction with simultaneous measurements from the newly established incoherent‐scatter radar facility at Sondre Stromfjord. The latitudinal location of the DPY current is compared with the location of the maximum F‐region electron temperature and with the location of the plasma convection reversal from sunward to antisunward. The maximum in the F‐region electron temperature roughly coincides with the velocity reversal boundary, while the …

The Meridional Thermospheric Neutral Wind Measured By Radar And Optical Techniques In The Auroral Region, Vincent B. Wickwar, J W. Meriwether Jr., P B. Hays, A F. Nagy

All Physics Faculty Publications

Radar observations of ion velocities in the magnetic zenith over Chatanika, Alaska, were used to determine the geomagnetic meridional component of the thermospheric neutral wind. Corrections for molecular diffusion and molecular ion contamination of the pure O⁺ composition assumed for the ionosphere were included in the analysis. Comparison of the averaged diurnal variation of the meridional wind showed good agreement between the two measurement techniques. Good agreement was also found for several cases of simultaneous observations. The evidence suggested that differences were caused by gravity waves. The 7 years of radar meridional wind results were examined with respect to …

Initial Millstone Hill, Sondrestrom, And Hilat Observations Of Thermospheric Temperatures And Frictional Heating, W L. Oliver, J C. Foster, J M. Holt, G B. Loriot, Vincent B. Wickwar, J D. Kelly, O De La Beaujardiere, P F. Bythrow, D I. Meng, F J. Rich, R E. Huffman

All Physics Faculty Publications

Elevation scan observations made by the Millstone Hill and Sondrestrom incoherent scatter radars are combined to provide extended latitudinal coverage of thermospheric measurements. Maps of the latitudinal and temporal structure of the exospheric temperature are presented for two 24‐hour periods over the latitude range 45 to 72 degrees north. On the magnetically quiet June day the Millstone and Sondrestrom data formed a consistent picture of thermospheric structure. On the disturbed July day the two radars observed very different behavior, with Millstone Hill observing strong, long‐lived ion frictional heating events but Sondrestrom observing more quiescent behavior. Comparison with HILAT satellite data …

Pitch Angle Properties Of Magnetospheric Thermal Protons And Satellite Sheath Interference In Their Observation, Jan Josef Sojka, G. L. Wrenn, J.F. E. Johnson

All Physics Faculty Publications

Cold proton observations from the geosynchronous GEOS 2 satellite are presented to show the pitch angle distribution of the refilling cold ion population found beyond the plasmapause. This refilling cold ion population flows into the depleted equatorial regions of the flux tubes from the topside ionosphere. This refilling is observed both day and night. The ions have energies between 0.5 and 3 eV. These energy characteristics are consistent with other recent observations. Although the observed angular distribution of these ions is highly complex, when allowance is made for the satellite sheath several conclusions can be made concerning the ion pitch …

Plasma Characteristics Of Polar Cap F-Layer Arcs, H C. Carlson Jr., Vincent B. Wickwar, E J. Weber, J Buchau, J G. Moore, W Whiting

All Physics Faculty Publications

First results are reported of a comprehensive campaign to measure ionospheric structure and dynamics of nighttime polar cap F‐layer or F‐region arcs. Airborne optical and digital ionosonde data were collected simultaneously with ground based incoherent scatter radar data, continuously over many hours in time and 500 to 1000 km in space. Polar cap F‐region sub‐visual auroral arcs, which are commonly observed during quiet magnetic conditions, are found to represent boundaries (or shears) in the polar cap plasma circulation pattern. F‐region electron concentration enhancements are found in these features and can be of significance to polar thermospheric circulation, composition, and thermal …

Observations Of Interplanetary Magnetic Field And Of Ionospheric Plasma Convection In The Vicinity Of The Dayside Polar Cleft, C R. Clauer, P M. Banks, A Q. Smith, T S. Jorgensen, E Friis-Christensen, S Vennerstrom, Vincent B. Wickwar

All Physics Faculty Publications

Dayside ionospheric convection at high latitudes has been examined during a series of experiments using the Sondrestrom radar together with ancillary observations of the interplanetary magnetic field (IMF) by the IMP‐8 spacecraft. The radar experiments obtained a latitude coverage of 67.6° Λ to 81.30° Λ and a temporal resolution of between 14 to 25 minutes. A total of 17 rotations through the dayside cleft region during April, June and July, 1983 have been examined. The observations show two convection cells with sunward flow at lower latitudes and antisunward flow at higher latitudes. The flow commonly rotates through a 180° angle …

Thermospheric Neutral Wind At –39° Azimuth During The Daytime Sector At Sondrestrom, Vincent B. Wickwar

All Physics Faculty Publications

Measurements with the Sondrestrom radar have been used to examine the daytime thermospheric neutral wind and to relate that wind to other geophysical parameters. Ion drag is found to be particularly important for determining the wind pattern. However, evidence is presented that the wind pattern is significantly influenced by soft particle precipitation and, possibly, by Joule heating.

Dayside Red Auroras At Very High Latitudes: The Importance Of Thermal Excitation, Vincent B. Wickwar, W Kofman

All Physics Faculty Publications

Extensive radar observations have been made from Sondrestrom of the F region in the daytime sector between 70 and 79° Λ. Regions of enhanced electron temperature and electron density are found in close association with the velocity reversal in the morning and afternoon convection cells. From the radar measurements, calculations are made of the contributions to the atomic oxygen emission at 6300A from dissociative recombination and thermal excitation. The latter mechanism, in particular, in the enhancement regions gives rise to intensities that are comparable to those observed at very high latitudes during the past decade.

Sondrestrom Overview, Vincent B. Wickwar, J D. Kelly, O De La Beaujardiere, C A. Leger, F Steenstrup, C H. Dawson

All Physics Faculty Publications

This overview of the Sondrestrom radar provides background material to help understand the early scientific results discussed in the following series of papers. It describes the geophysical region probed by the radar, the data acquisition procedure, and the extensive set of physical parameters derived.

A Theoretical F Region Study Of Ion Compositional And Temperature Variations In Response To Magnetospheric Storm Inputs, Jan Josef Sojka, Robert W. Schunk

All Physics Faculty Publications

The response of the polar ionosphere to magnetospheric storm inputs was modeled. During the “storm,” the spatial extent of the auroral oval, the intensity of the precipitating auroral electron energy flux, and the plasma convection pattern were varied with time. The convection pattern changed from a symmetric two-cell pattern with a 20-kV cross-tail potential to an asymmetric two-cell pattern with enhanced plasma flow in the dusk sector and a total cross-tail potential of 90 kV. During the storm there were significant changes in the ion temperature, ion composition, and molecular/atomic ion transition height. The storm time asymmetric convection pattern produced …

Review And Evaluation Of The Gibson Dome High Level Nuclear Waste Repository Environmental Assessment: Geohydrologic Issues, Christopher J. Duffy, Brad Hall

Reports

Introduction: Background/Authorization: This report is meant to provide a technical review and evaluation of Department of Energy documents concerning groundwater, radionuclide travel time and monitoring issues relative to siting a high level nuclear waste repository in the Gibson Dome area in Southern Utah. in so doing we have, during a relatively short period of time, examined in detail the Department of Energy Guidelines concerning high level nuclear waste disposal (1983) including revisions (1984), and each draft of the Environmental Assessments for Davis and Lavender Canyon, up to and including the fifth draft (dated July 27, 1984). In addition, a large …

Summary Report: Updating The Estimation Of Water Surface Elevation Probabilities And Associated Damages For Great Salt Lake, L. Douglas James, David S. Bowles, D. George Chadwick, J. Paul Riley

Reports

Problem Statement: Rising levels of the Great Salt Lake are severely impacting private and public property. in the private sector, the mineral industry, the railroad, and a number of recreation enterprises are suffering major damages. In the publi sector, the State of Utah is esperiencing large losses inflicted on roads and highways, waterfowl and related wildlife areas, and park and recreation facilities. The lake is partitioned by a semipervious railroad causeway into a north and a south arm with the sourth arm having about twice the water surface area and usually being two or three feet higher because it receibes …

Use Of The Hewlett-Packard 9810 Calculator System In Water Quality Analysis, Jerald S. Fifield

Reports

Introduction: It is the purpose of this manual to illustrate the utilization of the Hewlett-Packard, Model 9810A calculator for analyzing water quality data. Familiarization of each program's capabilities is essential for successful application, thus the user should read over the section used before beginning. Each section is complete with instructions and illustrative examples.

Arkansas Groundwater Management Via Target Level, Richard C. Peralta, Ann W. Peralta

Civil and Environmental Engineering Faculty Publications

AN approach to groundwater management by maintaining "target" groundwater elevations is presented. A finite difference form of the Boussinesq equation is proposed as a means of determining the groundwater withdrawals that will maintain those levels in the long term. This spatially distributed pumping can represent a sustained yielding pumping strategy. A sample pumping strategy is presented for the Arkansas Grand Prairie. Such a strategy is applicable under a variety of legal systems. It represents an especially attractive alternative for riparian rights states (like Arkansas) where effective groundwater management without radical changes in the basic water rights system is desired.

Erosion And Sedimentation In Utah: A Guide For Control, C. Earl Israelsen, Eugene K. Israelsen

Reports

No abstract provided.

Hydropower Potential At State Dam Logan River, Frank W. Haws

Reports

No abstract provided.

New Concepts For Preliminary Hydropower Design: The Powermax Slope, Binary Turbine Sizing, And Static Regain, Frank W. Haws, Eugene K. Israelsen

Reports

In Utah during the 1960s, the cost of producing electrical energy was as much, or in some cases more, by hydroelectric generation than by plants using steam from coal fired boilers. The relatively high hydropower cost was generally attributed to maintenance and replacement costs associated with plants that had been build in the 1920s. Utah Power & Light Company during the 1960 period decided not to renew power licenses and to abandon many small hdyroplants. Since 1973, rising coal and related fossil fuel costs have caused steam generation costs to accelerate and have made hydroelectric generation relatively more attractive. However, …

Sediment-Phosphorus Relationships In Deer Creek Reservoir, Jay J. Messer, Thomas B. Hardy, Jean M. Ihnat

Reports

Summary and Conclusions: Laboratory analyses of sediment samples recovered from Deer Creek Reservoir showed the sediments to have amoderate potential for serving as a source of phosphorus (P) for the overlying water solumn under anaerobic conditions. This source could account for the occurrence or exacerbation of blue-green algal blooms in the upper end of the reservoir when the sediment surface becomes anaerobic late in the summer. It could also delay the response of the reservoir to programs that decrease external P loading, if the upper end of the reservoir still has large enough algal blooms to render the sediment-water interface …

A Groundwater Model Of Cache Valley, Utah, Calvin G. Clyde, Roland W. Jeppson, Win-Kai Liu

Reports

This report describes the development, calibration and use of quantitative, predictive management model for the groundwater in the Utah portion of the Cache Valley in northern Utah. The quasi-three-dimensional finite difference computer model was adapted from the U.S. Geological Survey’s Trescott and Larson model and simulates the groundwater levels and flows in the groundwater basin. The variable spacing grid system is 23 nodes x 38 x 2 and represents the complex natural system by a simpler approximation with one unconfined and one confined aquifer and the appropriate boundary and initial conditions. River nodes, spring nodes, and constant head nodes were …