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

Digital Commons Network™

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

Utah State University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 13711 - 13740 of 16604

Full-Text Articles in Entire DC Network

Vulnerability Of Cougars To Hunting, Dan Barnhurst May 1986

Vulnerability Of Cougars To Hunting, Dan Barnhurst

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Forty radio-collared cougars (Felis concolor) were monitored for 630 cougar months. Track searches were conducted and tracking information was gathered over a 20-month period. Vulnerability was estimated to be greatest for 0 to 6-month-old kittens. This age class is the most susceptible to starvation after being orphaned, or being killed by hounds when the hunter is unaware of their presence, since their tracks were found with their mother's tracks only 19 percent of the time. Tracks of 7 to 12-month old kittens were found with their mother's tracks 43 percent of the time. Relative road-crossing frequencies of seven …


The Redevelopment Of Plant Community Diversity On A Surface Coal Mine In Southwestern Wyoming, Thomas Joseph Hatton May 1986

The Redevelopment Of Plant Community Diversity On A Surface Coal Mine In Southwestern Wyoming, Thomas Joseph Hatton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A study was initiated in 1981 to investigate the redevelopment of plant communities on a recontoured, surface-mined site in southwestern Wyoming. The landscape pattern of vegetation was compared with topographic position, the initial topsoil pattern, and cultural practices including shrub planting density, shrub planting pattern and topsoil treatments for the years 1982-1985. In addition, differences in vascular plant species diversity within these various factors and treatments were determined, along with the trend in intracommunity (alpha), intercommunity (beta) and landscape (gamma) diversity for the entire study area.

The influence of site factors and tested cultural practices on the differentiation of the …


Revegetation Of Denuded High Elevation Watersheds In Mustang, Nepal, Madhukar Upadhya May 1986

Revegetation Of Denuded High Elevation Watersheds In Mustang, Nepal, Madhukar Upadhya

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Lack of vegetative cover largely caused by such human activities as firewood collection, intensive grazing, and deforestation have accelerated the process of desertification at high elevation watersheds in Nepal. Mountain environment at high elevation is delicate and regeneration of vegetation is slow. Livestock grazing and firewood collection are the basic needs of the people. However, constant human pressure on natural vegetation upsets the hydrologic processes and results in disastrous soil erosion. Desertification caused by long-term soil erosion in semi-arid regions of Mustang district (a severely desertified, high elevation area) in Nepal probably indicates the future of other high elevation watersheds, …


Integration Of Precision Teaching Instructional Materials For Levels K-6 State Of Utah Core Curriculum Standards And Objectives In Math: A Directory For Computer Managed Instruction/Decision Making, Nancy Joanne Christner Williams May 1986

Integration Of Precision Teaching Instructional Materials For Levels K-6 State Of Utah Core Curriculum Standards And Objectives In Math: A Directory For Computer Managed Instruction/Decision Making, Nancy Joanne Christner Williams

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The State of Utah's Department of Education has developed an objective/outcome based education model, K-12 grade levels, based upon effective teaching research. The model components are 1) a core curriculum consisting of the basic elements essential for every student's educational program; 2) curriculum instruction based upon the mastery of educational outcomes at an appropriate level in accuracy and fluency, with a variety of options for learning; and 3) management systems which eliminate redundancy in the educational process. Two technological systems which have been piloted with some implementation through collaborations are the MID--Project developed at Utah State University and the CORVUS--Project …


Viruses In Water, Nasrin Mohammadpour Daryaee May 1986

Viruses In Water, Nasrin Mohammadpour Daryaee

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The use of water by man, plants and animals is universal. Without it there can be no life. Every living thing requires water. Man can live nearly two months without food, but can live only three or four days without water. In our homes, whether in the city or in the country, water is essential for cleanliness and health. Water can be considered as the principal raw material and the lowest cost raw material from which most of our farm produce is made. It is essential for the growth of crops and animals and is a very important factor in …


The Determination Of Wet Weight Concentrations Of Elements In Freeze-Dried Cryosections From Biological Cells, Karl Zierold Apr 1986

The Determination Of Wet Weight Concentrations Of Elements In Freeze-Dried Cryosections From Biological Cells, Karl Zierold

Scanning Electron Microscopy

Energy dispersive X-ray microanalysis in STEM (scanning transmission electron microscope) of freeze-dried cryosections from biological cells provides information on the subcellular element distribution in terms of dry weight concentration. The local dry weight content in the range of 5-50%, respectively the local water content within 50 to 95%, in different subcellular compartments can be determined by measuring the darkfield intensity by means of an annular detector in STEM. Calibration is done by measuring the darkfield intensity of similarly prepared cryosections from dextran-water-solutions in varying concentration. Thus, by combining the X-ray microanalytical data evaluated by the continuum method with the STEM …


Functional Aspects Of Renal Glomeruli Based On Scanning Electron Microscopy Of Corrosion Casts, With Special Emphasis On Reptiles And Birds, H. Ditrich, H. Splechtna Apr 1986

Functional Aspects Of Renal Glomeruli Based On Scanning Electron Microscopy Of Corrosion Casts, With Special Emphasis On Reptiles And Birds, H. Ditrich, H. Splechtna

Scanning Electron Microscopy

The glomerular complexity of several species of birds and reptiles is investigated in this study by scanning electron microscopy of vascular corrosion casts. Comparing these results with those of a freshwater teleost and a mammalian species, a trend towards small, simple glomeruli of the avian type, beginning with large, well vascularized glomeruli resembling the type found in fish, can be observed in reptiles.

A close correlation between glomerular size and habitat can be established comparing related species having a similar physiological mode of renal function.

Entirely different from this sauropsidian evolutionary line of development is the highly complex, large differentiation …


Technical Parameters Of Plastics (Mercox Cl-2b And Various Methylmethacrylates) Used In Scanning Electron Microscopy Of Vascular Corrosion Casts, T. Weiger, A. Lametschwandtner, P. Stockmayer Apr 1986

Technical Parameters Of Plastics (Mercox Cl-2b And Various Methylmethacrylates) Used In Scanning Electron Microscopy Of Vascular Corrosion Casts, T. Weiger, A. Lametschwandtner, P. Stockmayer

Scanning Electron Microscopy

The most frequently used resins for vascular corrosion casting Mercox Cl-2B, Mercox Cl-2B diluted with methylmethacrylate (MMA) monomer and various self prepared MMA and hydroxyproyl-methacrylate mixtures were tested with regard to their thermostability, shrinkage, viscosity and replication quality. It was found that tempering of the plastics improves their thermostability with the exception of Mercox Cl-2B and that shrinkage depends on the amount of monomers a resin contains. In detail; Mercox Cl-2B has the lowest shrinkage (8.018%) whereas a hydroxypropyl-methacrylate mixture possessed the highest (20.408%). But, on the other hand, viscosity decreases with the quantity of monomers. All resins tested were …


A Summary Of Ion Beam Etching Of Biological Material With Special Reference To The Saddle Field Source, D. Claugher Apr 1986

A Summary Of Ion Beam Etching Of Biological Material With Special Reference To The Saddle Field Source, D. Claugher

Scanning Electron Microscopy

A brief review of etching of biological materials using radio frequency, ion beam and electrostatic focused sources. Results of experiments using fast atom sources to dissect pollen, diatoms, protozoa and small arthropods, indicate that they produce a much smoother result which enables investigations to be carried out at high magnifications with the SEM.


Physical Basis For Spectrometer Calibration, M. Gautier, J. P. Duraud, J. P. Vigouroux, C. Le Gressus Apr 1986

Physical Basis For Spectrometer Calibration, M. Gautier, J. P. Duraud, J. P. Vigouroux, C. Le Gressus

Scanning Electron Microscopy

Progress in quantitative surface analysis is hampered by the lack of experimental procedure including spectrometer calibration, sample preparation, and general experimental setting-up. Two methods for spectrometer alignment are compared: the linearization method and the elastic peak test. Experimental spectra are presented, which can be considered as stringent reference data to check the instrument response and the analyser transmission at low energies.


Principles Of X-Ray Spectroscopy, Edwin R. Levin Apr 1986

Principles Of X-Ray Spectroscopy, Edwin R. Levin

Scanning Electron Microscopy

X-ray spectroscopy has become an essential tool for obtaining local chemical constituent data, particularly for identifying features observed in imaging systems. This tutorial paper is intended to introduce the basic ideas of X-ray spectroscopy, especially to the newcomer to scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The primary focus is on energy-dispersive analysis (EDS); however, the close parallels with wavelength-dispersive analysis (WDS) are shown. Topics include electron beam-specimen interactions, X-ray generation and detection, spectral analysis, approaches to quantitation, and limits of detection and resolution.


Surface Studies Of Duodenal Lesions Induced By Thoracic Irradiation, K. E. Carr, S. Ellis, A. Michalowski Apr 1986

Surface Studies Of Duodenal Lesions Induced By Thoracic Irradiation, K. E. Carr, S. Ellis, A. Michalowski

Scanning Electron Microscopy

Acute duodenal ulcers are produced in mice as a remote ("abscopal") effect of irradiation to the lower mediastinum. Such lesions have been examined with scanning electron microscopy at 5, 8 and 28 days after irradiation with 18 Gy of X-rays. All the ulcers occur within the first 1 cm long segment of the duodenum which is endowed with Brunner's glands. The single lesions vary in size, shape and position. The damaged area often includes much of the duodenal circumference and is distinguished by conical or rudimentary villi, or even by the complete absence of villi. In contrast, around the periphery …


Cell Ultrastructure In Disease, R. Laschi, E. Govoni Apr 1986

Cell Ultrastructure In Disease, R. Laschi, E. Govoni

Scanning Electron Microscopy

The doctor of today must adopt the 'cellular way of thinking' in the evaluation of diseases. This ultrastructural outlook provides him with much indispensable information that also serves a practical purpose. A diseased cell organelle is at the basis of every clinical sign and any attempt of therapy must be aimed at that specific point of lesion. We intend, in the light of a long experience, to propose to clinicians a new way of thinking in which a precise correlation between symptoms and sub-microscopic changes of the cell is considered. Many different examples amply justify this proposal. Electron microscopy can …


An Optimal Control Model For Analysis Of Timber Resource Utilization In Southeast Asia, Kenneth S. Lyon, Roger A. Sedjo, Bambang P. Adiwiyoto Apr 1986

An Optimal Control Model For Analysis Of Timber Resource Utilization In Southeast Asia, Kenneth S. Lyon, Roger A. Sedjo, Bambang P. Adiwiyoto

Economic Research Institute Study Papers

A discrete time optimal control forestry model is built and a shooting method solution algorithm identified. The applicability of the model and algorithm to public policies that affect forestry resources is demonstrated in an application of the model to examine the development of wood processing capacity in Southeast Asia. The necessary conditions of the optimal control model are manipulated to identify a difference equation problem with initial and terminal conditions. The solution to this boundry value problem is identified using a search routine that repetitively, numerically evaluates (shoots) the difference equations. The solution is the trajectory that satisfies the initial …


Utah Science Vol. 47 No. 1, Spring 1986 Apr 1986

Utah Science Vol. 47 No. 1, Spring 1986

Utah Science

2 ANNUAL FLOWERS W. A. Varga Looking for ways to add color and interest to the landscape? A USU horticulturist reviews the attributes of some annual flowers.

6 UNDERSTANDING PLANT-MICROBE COMMUNICATION Anne Anderson Eavesdropping on the "conversations" between plants and microbes may help researchers genetically engineer plants more resistant to pathogens and that can better utilize beneficial microorganisms.

9 WHOLE MILK OR MILK REPLACERS: A NUTRITIONAL AND ECONOMIC COMPARISON S. L. Maxfield. J. L. Walters, R. D. White, and S. D. Allen Even though prices for whole milk have declined in recent months, it still isn't economical to substitute marketable …


Signal Generation And Contrast Mechanisms In Scanning Electron Acoustic Microscopy, N. Kultscher, L. J. Balk Mar 1986

Signal Generation And Contrast Mechanisms In Scanning Electron Acoustic Microscopy, N. Kultscher, L. J. Balk

Scanning Electron Microscopy

In scanning electron acoustic microscopy (SEAM) until now the signal generation is explained mainly by an intermediate production of thermal waves. Though this so-called thermal wave approach has proven to give realistic results for metals, from experimental evidence it seems to fail for other material groups such as ceramics, dielectrics, piezoelectrics and semiconductors. As these material groups are of major technological importance, it is necessary to develop theories which help interpreting those SEAM micrographs obtained for these types of material.

In a comparative manner three different models are discussed in this paper, the well known thermal coupling, the piezoelectric coupling …


Elemental Content Of Anagen Hairs In A Normal Caucasian Population Studies With Proton Induced X-Ray Emission (Pixe), B. Forslind, H. K. Li, K. G. Malmqvist, D. Wiegleb Mar 1986

Elemental Content Of Anagen Hairs In A Normal Caucasian Population Studies With Proton Induced X-Ray Emission (Pixe), B. Forslind, H. K. Li, K. G. Malmqvist, D. Wiegleb

Scanning Electron Microscopy

The elemental content of anagen hair fibers in a Caucasian population of healthy females and males in the age range 10-69 years was performed to constitute a baseline for further studies of pathological conditions. Proton induced X-ray emission (PIXE) analyses were performed on single hair fibers in triplicates from 103 individuals in order to determine sulfur, zinc, calcium, and chlorine content. The hair fibers were all anagen hairs collected from a site little influenced by genetic and hormonal influences 1.5 cm above the right ear of the probands.

An area 5-8 mm from the follicle bottom was chosen for minimize …


Data Acquisition And Processing Techniques For Voltage Contrast Measurements, F. A. Dibianca, D. G. Johnson, C. R. Bagnell, E. I. Cole, W. V. Oxford, R. H. Propst, C. A. Smith Mar 1986

Data Acquisition And Processing Techniques For Voltage Contrast Measurements, F. A. Dibianca, D. G. Johnson, C. R. Bagnell, E. I. Cole, W. V. Oxford, R. H. Propst, C. A. Smith

Scanning Electron Microscopy

The effects of several data acquisition techniques on the accuracy of voltage contrast measurements are studied. In particular, the effect of using a voltage reference region directly connected to an external voltage source in performing the image intensity-to-voltage mapping of a node whose voltage is to be determined is examined. This is found to allow improved voltage measurement. The actual reference curves were obtained by least squares fitting the measured intensity-voltage reference data alternately to a quadratic and a cubic function. In addition, various mapping algorithms are considered including ones based alternately on the use of unprocessed, subtracted and normalized …


A Review Of Modern Characterization Methods For Semiconductor Materials, T. J. Shaffner Mar 1986

A Review Of Modern Characterization Methods For Semiconductor Materials, T. J. Shaffner

Scanning Electron Microscopy

The manufacture of solid state devices in the microelectronics industry involves crystal growth, slice preparation, diffusion and implantation, oxide and metal deposition, patterning and etching, probe testing and packaging of completed devices. This simplified process flow is adopted in an overview to briefly outline some established as well as newly developed techniques of materials characterization. The complexity of semiconductor processing has imposed greater stringency criteria which have resulted in the revitalization of old methods as well as the development of new techniques capable of extreme sensitivity and spatial resolution.

Examples given for trace impurity and dopant detection include neutron activation …


Deconvolution In Auger Electron Spectroscopy, B. Chornik, H. E. Bishop, A. Le Moel, C. Le Gressus Feb 1986

Deconvolution In Auger Electron Spectroscopy, B. Chornik, H. E. Bishop, A. Le Moel, C. Le Gressus

Scanning Electron Microscopy

Deconvolution calculations have been applied in Auger Electron Spectroscopy to increase resolution and/or to eliminate loss features. We present: i) A short review of the methodology; ii) Recent results obtained in our laboratory in spectroscopy of Al, Ni, Cu, Ag and Te; iii) A discussion on the conditions for the appearance of artefacts originating either in the calculation or the physical processes (emission anisotropy, distribution of electron path lengths, and intrinsic losses).


Effects Of Monetary Changes On The Price Level And Output In The U.S. Agricultural Sector, Peter J. Saunders, Deevon Bailey Feb 1986

Effects Of Monetary Changes On The Price Level And Output In The U.S. Agricultural Sector, Peter J. Saunders, Deevon Bailey

Economic Research Institute Study Papers

Accelerating inflation in the late 1970s and early 1980s led to renewed interest in empirical testing the causes of inflation. Although several possible causes of inflation have been suggested, all can be broadly divided into two major categories. The first is the keynesian or structuralist explanation asserting that inflation is directly caused by real shocks in some sectors of the economy. These exogenous shocks can be due to many factors, such as global crop failures, increases in prices of raw material, and other factors of this nature. The real shocks lead to a contraction in output which in turn increases …


Analytical Ultra High Vacuum Scanning Electron Microscopy With Field Emission Gun For Surface Study, P. Morin, P. Abraham, C. Bablet, M. Tholomier Jan 1986

Analytical Ultra High Vacuum Scanning Electron Microscopy With Field Emission Gun For Surface Study, P. Morin, P. Abraham, C. Bablet, M. Tholomier

Scanning Electron Microscopy

Surface studies can be carried out with a scanning electron microscope (SEM) having an ultra high vacuum specimen chamber. The main application of this SEM was the micro Auger analysis, but it is also interesting to combine the usual surface study technique with SEM observations. Indeed, these latter give valuable in formation about the topographic, chemical and crystallographic aspects of the surface when the secondary, backscattered and transmission SEM modes are used. The SEM performances are increased by the use of a field emission gun, the high brightness beam of this gun gives new observation possibilities such as the imaging …


Folk Art And Art Worlds, John Michael Vlach, Simon J. Bronner Jan 1986

Folk Art And Art Worlds, John Michael Vlach, Simon J. Bronner

All USU Press Publications

Respected voices combine in this volume to address the fundamental issues pertaining to American folk art. The eleven original essays explore the changing face of folk art in its different contexts or folk art "worlds"--the worlds of the creator, the academic, the art dealer, the gallery or museum, and the community. A new Introduction considers supplemental works on American Folk Art that have appeared since the volume was first published.


Proceedings From The 23rd Annual Marschall Invitational, Various Authors Jan 1986

Proceedings From The 23rd Annual Marschall Invitational, Various Authors

Cheese Industry Conference

No abstract provided.


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 …


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 …


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 …


Mountain Pine Beetle Outbreaks In The Rocky Mountains: Regulators Of Primary Productivity?, W. H. Romme, D. H. Knight, J. B. Yavitt Jan 1986

Mountain Pine Beetle Outbreaks In The Rocky Mountains: Regulators Of Primary Productivity?, W. H. Romme, D. H. Knight, J. B. Yavitt

The Bark Beetles, Fuels, and Fire Bibliography

We consider the hypothesis that mountain pine beetles function as cybernetic regulators of primary productivity in ecosystems of lodgepole pine forest through their selective killing of dominant trees and the subsequent redistribution of resources. Following a recent major beetle outbreak in Yellowstone and Grand Teton national parks, surviving trees did grow significantly faster (P < .1); wood production was redistributed among canopy, subcanopy, and understory trees; and annual wood production per hectare usually returned to pre-attack levels or exceeded them within 10-15 yr. However, reconstructions of annual wood production over the last 70-80 yr indicate that the beetle outbreak did not reduce the variation in productivity; rather, the beetles introduced more variation than would have existed in their absence. Hence, our results do not support the hypothesis that the beetles function as cybernetic regulators (in the strict sense). Nevertheless, the beetle-pine system that we studied shows great resilience, and the effects of beetles on primary productivity do not appear to be as severe as conventional wisdom maintains. Annual wood production per hectare returned quickly to previous levels in the stands we studied, and associated ecological changes can be considered generally benign or even beneficial.


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 …


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 …