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 9601 - 9630 of 13060

Full-Text Articles in Entire DC Network

Predicting Quaking Aspen Stand Dynamics In Minnesota, R.A. Leary, G.J. Brand, D.A. Perala Jan 1993

Predicting Quaking Aspen Stand Dynamics In Minnesota, R.A. Leary, G.J. Brand, D.A. Perala

Aspen Bibliography

This paper presents equations for predicting future basal area, number of trees, and total cubic-foot volume of aspen stands in Minnesota. The modeling methodology uses a fully-stocked yield table for quaking aspen as a density standard. A relative density change equation based on observed growth from permanent plots provides the basis for predicting the future relative density and therefore the future basal area, number of trees, and volume. The equations are easy to apply and require only site index, age, and beginning basal area, number of trees, and volume. North. J. Appl. For. 10(1):20-27.


Proton‐Donor Properties Of Water And Ammonia In Van Der Waals Complexes. Be–H2o And Be–Nh3, G. Chalasinski, M. M. Szczesniak, Steve Scheiner Jan 1993

Proton‐Donor Properties Of Water And Ammonia In Van Der Waals Complexes. Be–H2o And Be–Nh3, G. Chalasinski, M. M. Szczesniak, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The potential energy surfaces (PES) of Be–H2O and Be–NH3 are studied with particular attention to characterization of proton‐donor properties of water and ammonia. Calculations were performed by means of both supermolecular and intermolecular Møller Plesset perturbation theory. The Be–H2O PES reveals two van der Waals minima: the C2v minimum (De=176 cm−1, Re=6.5 bohr), and the H‐bonded minimum (De=161 cm−1, Re=7.5 bohr), separated by a barrier of 43 cm−1 at the T‐shaped configuration. The Be–NH3 PES reveals only …


Best Management Of Pesticide And Irrigation Application Systems: Background And Candi Software, Alaa H. Aly, Richard C. Peralta, Howard M. Deer Jan 1993

Best Management Of Pesticide And Irrigation Application Systems: Background And Candi Software, Alaa H. Aly, Richard C. Peralta, Howard M. Deer

Civil and Environmental Engineering Faculty Publications

In this chapter, we discuss a commonly-used volume balance approach for simulating the movement of water through the root zone. We then show how this approach can be coupled with pesticide leaching prediction. Finally we show how information about irrigation system design can be used with the previous processes. The result is an integrated approach for estimating the environmental consequences of irrigation and pesticide management.


Effectiveness Determination Of Two Different Water-Saving Devices For Toilet Tanks, C. Earl Israelsen, Gilberto Urroz Jan 1993

Effectiveness Determination Of Two Different Water-Saving Devices For Toilet Tanks, C. Earl Israelsen, Gilberto Urroz

Reports

Introduction: The project was successful in obtaining eight different brands of new toilet tanks in the 3.5 gals-per-flish-bariety, and two used ones requiring 5.0 gals per flish. The tanks were installed on a t atime on a padded stell frame and connected to a water supply. The float was adjusted to maintain the water in the tank at the level recommended by the manufacturer. When the flush and shut-off mechanisms were adjusted properly, the testing begain.


Present Developments In Image Analysis, Peter Smart, Xiaoling Leng Dec 1992

Present Developments In Image Analysis, Peter Smart, Xiaoling Leng

Scanning Microscopy

The paper discusses novel methods of analysing oriented textures, explains some of the problems which had to be overcome to make these methods work, and indicates where future developments might be expected. This has required improvements in the methods of intensity gradient analysis, the development of large filter methods for mapping features defined in terms of their texture, and the introduction of ideas from the theory of regionalised variables.


Insights, Winter, 1992, Utah State University Dec 1992

Insights, Winter, 1992, Utah State University

Discovery Magazine

Bi-annual alumni newsletter for the College of Science of Utah State University in Logan.


Intrinsic Loss In Infrared Optical Fibers, Prapassorn Tantiphanwadi Dec 1992

Intrinsic Loss In Infrared Optical Fibers, Prapassorn Tantiphanwadi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Recently, in communication system, fiber optics has become a most interesting development tool as a transmission medium. It first appeared as a feasible transmission medium in 1970. The reason for the development in fiber optics comes from the overwhelming advantage in technology and economy compared to wires and coaxial links. For technology progress, typically, optical fiber has a wide transmission band-width (0.1-1000 GHz), lower loss per unit length (0.15 – 5 dB km-1[1]), and does not allow electromagnetic interference. For example, signal transmitted over commercial silica-based fiber must be reamplified every 10 to 50 kilometers, whereas signals transmitted …


Effects Of Citrate On The Different Phases Of Calcium Oxalate Crystallization, H. -G. Tiselius, C. Berg, A. -M. Fornander, M. -A. Nilsson Nov 1992

Effects Of Citrate On The Different Phases Of Calcium Oxalate Crystallization, H. -G. Tiselius, C. Berg, A. -M. Fornander, M. -A. Nilsson

Scanning Microscopy

Urinary citrate appears to be an important factor in the crystallization process of calcium oxalate and calcium phosphate. The urinary excretion of citrate was found to be significantly lower in patients with calcium oxalate stone disease as compared with normal subjects, and about 30 per cent of the calcium stone formers can be considered as hypocitraturic. The lowest excretion of citrate was recorded in urine collected during the night. Citrate has significant effects on supersaturation with respect to both calcium oxalate and calcium phosphate, it also inhibits the growth of these crystals. In addition, citrate appears to be capable of …


Exact Enumeration And Scaling For Fragmentation Of Percolation Clusters, Boyd F. Edwards, M. F. Gyure, M. V. Ferer Nov 1992

Exact Enumeration And Scaling For Fragmentation Of Percolation Clusters, Boyd F. Edwards, M. F. Gyure, M. V. Ferer

All Physics Faculty Publications

The fragmentation properties of percolation clusters yield information about their structure. Monte Carlo simulations and exact cluster enumeration for a square bond lattice and exact calculations for the Bethe lattice are used to study the fragmentation probability as(p) of clusters of mass s at an occupation probability p and the likelihood bs′s(p) that fragmentation of an s cluster will result in a daughter cluster of mass s′. Evidence is presented to support the scaling laws as(pc)∼s and bs′s(pc)=s-φg(s′/s), with φ=2-σ given by the standard cluster-number scaling …


Mapping Instream Habitat On The San Juan River Using Airborne Videography, Michael J. Pucherelli, William P. Goettlicher, Bureau Of Reclamation, U.S Department Of The Interior Nov 1992

Mapping Instream Habitat On The San Juan River Using Airborne Videography, Michael J. Pucherelli, William P. Goettlicher, Bureau Of Reclamation, U.S Department Of The Interior

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

Concerns have been raised over the potential impacts of the Animas/LaPlata project and the regulation of Navajo Dam. Flow depletions in the San Juan River may adversely affect the remnant population of the native fish, particularly the endangered Colorado squawfish and the razorback sucker. A multiyear research program is currently being conducted on the San Juan River as a result of a Jeopardy Opinion delivered by the U.S. Fish and Wildlife Service on Animas/LaPlata and the subsequent Reasonable and Prudent Alternative that was accepted. A mulidisciplinary research team composed of representatives from the affected agencies is currently investigating the relationship …


Calibration Of Atomic Force Microscope Tips Using Biomolecules, T. Thundat, X.-Y. Zheng, S. L. Sharp, D. P. Allison, R. J. Warmack, D. C. Joy, T. L. Ferrell Oct 1992

Calibration Of Atomic Force Microscope Tips Using Biomolecules, T. Thundat, X.-Y. Zheng, S. L. Sharp, D. P. Allison, R. J. Warmack, D. C. Joy, T. L. Ferrell

Scanning Microscopy

Atomic force microscope (AFM) images of surfaces and samples mounted on substrates are subject to artifacts such as broadening of structures and ghost images of tips due to the finite size and shape of the contacting probe. Therefore, knowledge of the radius of the AFM probe tip is essential for the interpretation of images. We have deduced the shape of the AFM tip by imaging cylindrical biological molecules of various diameters such as deoxyribonucleic acid (DNA), tobacco mosaic virus (TMV), tobacco etch virus (TEV) and bacteriophage M-13 (M-13). Using a paraboloidal tip model and numerically solving equations of contact, the …


Hydrodynamic Instability Of Chemical Waves, D. A. Vasquez, J. W. Wilder, Boyd F. Edwards Oct 1992

Hydrodynamic Instability Of Chemical Waves, D. A. Vasquez, J. W. Wilder, Boyd F. Edwards

All Physics Faculty Publications

We present a theory for the transition to convection for flat chemical wave fronts propagating upward. The theory is based on the hydrodynamic equations and the one‐variable reaction‐diffusion equation that describes the chemical front for the iodate–arsenous acid reaction. The reaction term involves the reaction rate constants and the chemical composition of the mixture. This allows the discussion of the effects of the different chemical variables on the transition to convection. We have studied perturbations of different wavelengths on an unbounded flat chemical front and found that for wavelengths larger than a critical wavelength (λ≳λc) the perturbations grow …


Populating The Abyss-Investigating More Efficient Orbits -Or- "Getting More Miles To The Gallon For Your (Space) Vehicle", John Draim, Thomas Kacena Sep 1992

Populating The Abyss-Investigating More Efficient Orbits -Or- "Getting More Miles To The Gallon For Your (Space) Vehicle", John Draim, Thomas Kacena

Small Satellite Conference

Most satellites operating in orbit are spatially distributed in one of the following regions: LEO (below 600 nm and below), MEO (Molniya and GPS), and GEO (synchronous circular). Other than Molniya and a few similar systems, little use has been made of either elliptic orbits or the 'middle-ground' orbits lying between 600 nm and synchronous altitude. This paper explores the potential for exploiting these less populated regions and demonstrates that analyzing system optimization parametrically may in fact, also dictate an increasing interest in this new territory. A non-dimensional coverage parameter is presented which indicates that the 'efficiency' of an orbit …


Utah Families- The Issues They Face, Ted W. Warstadt, Larry Forthun Sep 1992

Utah Families- The Issues They Face, Ted W. Warstadt, Larry Forthun

All Archived Publications

With the wide variety of difficulties that our society faces and the limited funding available to address these concerns, it is important to identify and prioritize critical family issues. Because the family is a major contributor to individual and societal development, it is important to focus attention on issues which have a direct impact on family functioning. In identifying issues it is also helpful to understand demographic and geographic influences which may contribute to an individual's perceived urgency of a given issue. This can assist policy makers in their efforts to appropriately allocate limited funds to the best suited and …


Photosynthesis And Leaf Morphology Of Liquidambar Styraciflua L. Under Variable Urban Radiant Energy Conditions, Roger Kjelgren, James R. Clark Sep 1992

Photosynthesis And Leaf Morphology Of Liquidambar Styraciflua L. Under Variable Urban Radiant Energy Conditions, Roger Kjelgren, James R. Clark

Plants, Soils, and Climate Faculty Publications

Diminished sunlight, characteristic of urban canyons, has been suggested as being potentially limiting to plant growth. This study investigated the response of sweetgum (Liquidambar styraciflua L.) to variable irradiance in a range of urban locations. Diurnal photosynthesis was measured in situ on mature trees, comparing an open site at an urban park with an urban canyon that received 4 h of midday sun in midsummer. Photosynthesis for trees growing in the canyon was lower both during shaded and sunlit periods compared with trees at the park. Photosynthesis of detached shoots in a growth chamber was greater in canyon than park …


Ultrahigh Vacuum Chamber For Synchrotron X-Ray Diffraction From Films Adsorbed On Single-Crystal Surfaces, John R. Dennison, S. K. Wang, P. Dai, T. Angot, H. Taub, S. N. Ehrlich Aug 1992

Ultrahigh Vacuum Chamber For Synchrotron X-Ray Diffraction From Films Adsorbed On Single-Crystal Surfaces, John R. Dennison, S. K. Wang, P. Dai, T. Angot, H. Taub, S. N. Ehrlich

All Physics Faculty Publications

An ultrahigh vacuum chamber has been developed for structural analysis of adsorbed films and single‐crystal surfaces using synchrotron x‐ray diffraction. It is particularly well suited for investigations of physisorbed and other weakly bound films. The chamber is small enough to transport and mount directly on a standard four‐axis diffractometer and can also be used independently of the x‐ray diffractometer. A low‐current, pulse‐counting, low‐energy electron diffraction/Auger spectroscopy system with a position‐sensitive detector enables in situ characterization of the film and substrate while the sample is located at the x‐ray scattering position. A closed‐cycle He refrigerator and electron bombardment heater provide controlled …


An Approach To Solid Phase Identification In A Ca-S-O System By Quantitative Energy Dispersive X-Ray Microanalysis, K. Wieczorek-Ciurowa, S. J. Sivonen, P. Kokkonen Jul 1992

An Approach To Solid Phase Identification In A Ca-S-O System By Quantitative Energy Dispersive X-Ray Microanalysis, K. Wieczorek-Ciurowa, S. J. Sivonen, P. Kokkonen

Scanning Microscopy

Solid phases formed in the limestone sulphation reaction were identified by scanning electron microscopy with backscattered electron (BSE) imaging and by quantitative energy dispersive X-ray (EDX) microanalysis of calcium and sulphur. Since calcium and sulphur can form several compounds in the Ca-S-O system, two quantities, the sum of oxides (CaO+SO3) and the molar ratio (CaO/SO3), were used to calculate empirical formulae for the compounds actually present.

A method for analysing the experimental results is proposed, the mathematical expressions employed are presented and the numerical coefficients tabulated. It is shown with some examples that the method used …


Electron Mean-Free Paths In The Alkali Metals, G. K. Wertheim, D. Mark Riffe, N. V. Smith, P. H. Citrin Jul 1992

Electron Mean-Free Paths In The Alkali Metals, G. K. Wertheim, D. Mark Riffe, N. V. Smith, P. H. Citrin

All Physics Faculty Publications

Photoemission data in which the signal from the first atomic layer is well resolved from that of the bulk are used to determine accurately the kinetic-energy dependence of the inelastic-electron mean free path in the alkali metals. At the higher kinetic energies, the data are in very good agreement with the theory of Penn. Below about 10 eV, the mean free path in the heavier alkali metals drops markedly below the theoretical values. This is attributed to electron decay processes involving the unoccupied d bands.


Convective Instability Of Autocatalytic Reaction Fronts In Vertical Cylinders, D. A. Vasquez, J. W. Wilder, Boyd F. Edwards Jul 1992

Convective Instability Of Autocatalytic Reaction Fronts In Vertical Cylinders, D. A. Vasquez, J. W. Wilder, Boyd F. Edwards

All Physics Faculty Publications

Linear stability analysis predicts that the onset of convection for an ascending autocatalytic reaction front in a vertical cylinder corresponds to a nonaxisymmetric mode. This mode consists of a single convective roll confined to the region near the reaction front, with fluid rising in half of the cylinder and falling in the other half. Experiments show a flat front below the onset of convection and an axisymmetric front well above the onset of convection. New experiments are called for to closely examine the onset of convection in order to test this prediction.


On A Nature Of Cathodoluminescence Contrast Of Fine-Dispersed Structures In The Scanning Electron Microscope, M. V. Viskov, S. K. Obyden, G. V. Saparin Jun 1992

On A Nature Of Cathodoluminescence Contrast Of Fine-Dispersed Structures In The Scanning Electron Microscope, M. V. Viskov, S. K. Obyden, G. V. Saparin

Scanning Microscopy

Fine-dispersed structures (FDS) consisting of a large number of microcrystalline or amorphous particles of different sizes and shapes were examined in cathodoluminescence (CL) mode scanning electron microscopy (SEM). Line dimension of each particle (about 10 - 100 μm) was larger than the electron beam diameter as well as electron scattering volume in material under investigation. An analysis of observed images showed the existence of some peculiarities in contrast which have not been observed in the CL-images for solid specimens. The FDS CL-image topographic contrast arises as a result of detection of CL-emission from an aggregate of FDS-elements surrounding an irradiated …


Enamel Structure In Astrapotheres And Its Functional Implications, John M. Rensberger, Hans Ulrich Pfretzschner Jun 1992

Enamel Structure In Astrapotheres And Its Functional Implications, John M. Rensberger, Hans Ulrich Pfretzschner

Scanning Microscopy

Astrapotheres, large extinct ungulates of South America, share with rhinoceroses vertical prism decussation in the cheek tooth enamel. The similarity extends beyond merely the direction of the planes of decussation. The vertical decussation in astrapotheres is confined to the inner part of the enamel and has uniformly well-defined zones in which the prism direction differs by nearly 90° and the zones are separated by narrow transitional borders of intermediate prism direction. The outer enamel consists of predominantly occlusally and outwardly directed prisms. Within the outer enamel is a region of horizontally decussating prisms; here the angle of decussation is usually …


Early Effects On The Morphology Of Mouse Small Intestine Of Single Or Combined Modality Treatment With Hyperthermia And X-Irradiation, G. R. Dickson, H. M. H. Kamel, S. P. Hume, M. Jaber, K. E. Carr Jun 1992

Early Effects On The Morphology Of Mouse Small Intestine Of Single Or Combined Modality Treatment With Hyperthermia And X-Irradiation, G. R. Dickson, H. M. H. Kamel, S. P. Hume, M. Jaber, K. E. Carr

Scanning Microscopy

This study describes the effects of hyperthermia and X-irradiation on the morphological appearance of normal, at risk tissues in the ileum of the mouse. The early morphological effects day after a combined modality treatment are compared with those due to either hyperthermia or X-irradiation given alone. The response was assessed qualitatively and semiquantitatively using scanning electron microscopy and a villous scoring technique.

Early post-irradiation effects on topography did not differ significantly from those observed after small intestine exteriorisation without treatment. The villous scores for the combined modality treatments reflected greater damage than would be expected from the sum of villous …


Utah State University Commencement, 1992 – Main Campus, Utah State University Jun 1992

Utah State University Commencement, 1992 – Main Campus, Utah State University

Commencement Programs

Ninety-Ninth Annual Commencement of Utah State University


Final Environmental Impact Statement For Rangeland Ecosystem Management On He Uinta National Forest, Provo, Utah, Usda Forest Service Jun 1992

Final Environmental Impact Statement For Rangeland Ecosystem Management On He Uinta National Forest, Provo, Utah, Usda Forest Service

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

This Final Environmental Impact Statement describes alternatives, including a "No Action" alternative for management of National Forest Rangeland Resources on the Uinta National Forest. Alternatives range from no change from past management practices, which in some instances have resulted in less than favorable ecological conditions on National Forest Rangelands and riparian resources, to managing these resources to achieve the "Potential Natural Community" in terms of vegetative cover types and condition. The environmental consequences of all alternatives considered in detail are displayed. The alternatives selected for implementation will become an amendment to the Uinta National Forest Land and Resource Management Plan. …


Off-Line Data Evaluation Of Elemental Maps Obtained From Scanning Nuclear Microprobe Analyses, N. E. G. Lövestam, E. Swietlicki May 1992

Off-Line Data Evaluation Of Elemental Maps Obtained From Scanning Nuclear Microprobe Analyses, N. E. G. Lövestam, E. Swietlicki

Scanning Microscopy

The results of scanning nuclear microprobe (SNM) analyses are normally presented as elemental maps showing the number of detector events, acquired within a certain energy region, for every pixel irradiated. Such elemental maps can be misleading if they are interpreted as directly reflecting the variations in the elemental concentrations across the analysed sample. The aim of this paper is to demonstrate how such elemental maps can be treated in order to facilitate the interpretation and extract the information contained in the data set, such as the covariation between elements. Examples of sample thickness correction, image processing and spectrum filtering as …


Idaho River Systems Management Study Wetlands Report, United States Department Of The Interior, Bureau Of Reclamations May 1992

Idaho River Systems Management Study Wetlands Report, United States Department Of The Interior, Bureau Of Reclamations

Natural Resources-Planning, Management, and Conservation

The Bureau of Reclamation is cooperating with the Idaho Department of Water Resources and others in the formulation of a comprehensive water plan for the conservation, development, management, and use of waters within the state's river basins. The impact that wetlands may have on the use of water in the state is a major consideration.

This report identifies opportunities that exist for private citizens, corporations, government agencies, and others to work together to slow the rate of wetland loss and to improve the quality of remaining wetlands. To work together effectively, these groups must reach an understanding of what comprises …


A Critique Of "The Mormon Concept Of God, A Philosophical Analysis", Kyle Robson May 1992

A Critique Of "The Mormon Concept Of God, A Philosophical Analysis", Kyle Robson

Undergraduate Honors Capstone Projects

The nature of deity through out the history of philosophy has always been a subject of debate, from some of the earliest writings, philosophers and theologians have given arguments for and against the existence and nature of God. Beckwith and Parrish, in "The Mormon Concept Of God, A Philosophical Analysis," add another page to this on-going debate with their attack of the "Mormon concept of God." In the introduction Beckwith and Parrish explain that it is their aim to show

(1) that the Mormon concept of God differs radically from the classical concept of God,

(2) that the Mormon concept …


Quaternary Geology And Neotectonics Of Southern Star Valley And The Southwest Flank Of The Salt River Range, Western Wyoming, Gregory A. Warren May 1992

Quaternary Geology And Neotectonics Of Southern Star Valley And The Southwest Flank Of The Salt River Range, Western Wyoming, Gregory A. Warren

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Southern Star Valley is a structural and physiographic basin bounded on the east by the southern Star Valley fault, an active normal fault associated with Basin and Range extension. The southern Star Valley fault separates southern Star Valley from the Salt River Range and forms a dramatic north-south trending topographic escarpment. Statistical analysis of relative-age dating (RD) parameters taken from glacial deposits in the Salt River Range defined distinctive age groups for the deposits, and comparison of RD data allowed correlations with late Pleistocene and Holocene glacial deposits elsewhere in the Rocky Mountains. However, the sedimentary lithologies in the glacial …


Demographic Influences On Perceived Urgency Of Family Life Issues In Utah, Ted W. Warstadt May 1992

Demographic Influences On Perceived Urgency Of Family Life Issues In Utah, Ted W. Warstadt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study recognizes the need to identify and prioritize critical issues facing families. The literature review identifies and documents a number of critical issues facing families in American society. Survey questionnaires, which contained an abstract version of 33 previously identified issues, were sent to a sample of 2,000 people in Utah. The sample was randomly selected from resident listings in Utah telephone books. The survey asked respondents to rate each of 33 issues on a scale of 1 to 10, 1 being the least urgent and 10 being the most urgent. These issues include childhood, economic, health, and elderly concerns. …


Home/School/Community Factors Which Compete With Time High School Students Spend On Homework, John A. Sadler May 1992

Home/School/Community Factors Which Compete With Time High School Students Spend On Homework, John A. Sadler

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Home/school/community factors of student jobs, extracurricular activities, church activities, community activities, family activities, and television watching were examined to determine the relationship between these factors and the time students spent on homework. Two hundred forty-seven high school students were used as subjects. A student time log and questionnaire were developed and used to collect the data. Eight students were closely examined through case studies. When time spent on homework was correlated with time spent at a job, the results were strongly negative (r = -.89). Time spent on homework was moderately correlated (r= + .46) with time …