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1999

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Non-Intrusive Assessment Of Radionuclides In Enclosed Pipes And Vessels, Traci Renee Glew Jan 1999

Non-Intrusive Assessment Of Radionuclides In Enclosed Pipes And Vessels, Traci Renee Glew

UNLV Retrospective Theses & Dissertations

The assessment and cleanup of various nuclear sites throughout the country has become an increasingly important issue. Methods for assessment of radioactive material within pipe and duct systems at these sites must be cost effective, efficient, and safe. Several tests were conducted at the University of Nevada, Las Vegas, using both steel and aluminum pipes with a Cesium 137 source placed inside. A Geiger-Muller pancake detector was used to measure gamma rays from several angular positions and at various axial distances along the outside of the pipe. A plot of the data showed excellent results despite the low efficiency of …

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United States Business Travelers' Response To Price Changes And Overbooking: Its Effect On Intentional Loyalty In The Hospitality Industry, Nicholas Jee Gordon Jan 1999

United States Business Travelers' Response To Price Changes And Overbooking: Its Effect On Intentional Loyalty In The Hospitality Industry, Nicholas Jee Gordon

UNLV Retrospective Theses & Dissertations

Companies that have highly perishable inventories have used yield management quite extensively over the past decade. The process helps to maximize revenues based on demand. The airline industry was the first to adopt the process into a business setting and has seen varying results along the way. Much of the existing research is geared towards examining the revenue producing potential of the system. There has been little research however, to examine how this process of shifting price to manipulate demand effects customer loyalty; This research attempts to evaluate what the effects actually are when price is used as the major …

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On Lossless Image Compression, Huawen He Jan 1999

On Lossless Image Compression, Huawen He

UNLV Retrospective Theses & Dissertations

Accompanying the growth in the size of database and the use of images has been a large increase in the number of users and duration of usage by personnel at remote locations. These factors result in tremendous amounts of data being stored and transferred between computers and remote terminals. Data compression is therefore very important to reduce the size of data files and the time needed to transfer between the remote terminals. A wide variety of compression techniques have been developed over past 20 years to reduce size of image files. Some techniques represent the application of modified lossless compression …

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"Welcome, Fellow Toastmasters": The History And Membership Of A Public Speaking Phenomenon, Ellen Beth Levine Bremen Jan 1999

"Welcome, Fellow Toastmasters": The History And Membership Of A Public Speaking Phenomenon, Ellen Beth Levine Bremen

UNLV Retrospective Theses & Dissertations

Since 1905, Toastmasters International (TI) serves as the most recognized organization for voluntary oral communication practice in the world. Due to the dearth of scholarly communication research regarding TI, this thesis details the history, educational structure, and program dynamics of the organization. Literature review included the nature and extent of post-secondary communication education, as well as social affiliation and leisure theories. Finally, an Internet survey of 343 international TI members revealed the demographics of the "typical" TI member: a male or female college graduate between the ages of 36--50, who works in a wide range of professions. The study also …

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Measuring Efficiency In The Clark County Hotel Casino Industry, Daniel Encinoza Jan 1999

Measuring Efficiency In The Clark County Hotel Casino Industry, Daniel Encinoza

UNLV Retrospective Theses & Dissertations

The analysis and comparison of productivity in the service sector have proven to be difficult. Nevertheless, the Tomqvist index of relative productivity used in this study allows me to compare the relative productivity of different hotel-casino properties, while avoiding the usual problems that arise when measuring efficiency in service industries. This empirical study illustrates the efficiency of index numbers in evaluating relative efficiency. The simplicity of the model and its ability to evaluate all aspects of the production process, including economies of scale, renders this methodology far superior to the use of direct indexes. From calculations included in the study, …

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Effect Of Atmospheric Variations On Subsurface Flow And Transport, Laila Badran Jan 1999

Effect Of Atmospheric Variations On Subsurface Flow And Transport, Laila Badran

UNLV Retrospective Theses & Dissertations

This thesis investigates the effect of atmospheric variations on subsurface flow and transport at the proposed high level waste repository at Yucca Mountain, Nevada. The conditions of subsurface transport were simulated with NUFT (Nonisothermal Unsaturated-Saturated Flow and Transport model) modeling software developed by the Lawrence Livermore National Labs (Nitao, 1995). Rock properties and surface ambient conditions specific to the mountain, including diurnal and seasonal changes in temperature, pressure and humidity were incorporated into the NUFT model. The effects of changing atmospheric conditions on the liquid and vapor phase components and fluxes were examined as well. Time swing analysis of weather …

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A Study To Determine The Minimum Autocad Command Set For Computer-Aided Drafting In The Las Vegas Area, David John Brodersen Jan 1999

A Study To Determine The Minimum Autocad Command Set For Computer-Aided Drafting In The Las Vegas Area, David John Brodersen

UNLV Retrospective Theses & Dissertations

The purpose of this study was to identify the computer aided drafting (CAD) commands most frequently used in the industrial application of the thirteenth release of the software product AutoCAD, vended by AutoDESK. Respondents were located within the Las Vegas drafting community and nearby areas. The outcome of this study was used to identify commands needed to operate the software at a desired level of competency and to identify any relationship between the release thirteen commands used by the respondents and commands available in the previous release of the software; A questionnaire was delivered to 90 businesses engaged in drafting …

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Fast Algorithms For Wavelet-Based Analysis Of Hyperspectral Signatures, Jiang Li Jan 1999

Fast Algorithms For Wavelet-Based Analysis Of Hyperspectral Signatures, Jiang Li

UNLV Retrospective Theses & Dissertations

Hyperspectral sensors promise great improvements in the quality of information gathered for remote sensing applications. However, they also present a huge challenge to data storage and computing systems. Thus there is a great need for reliable compression schemes, as well as analysis tools that can exploit the hyperspectral data in a computationally efficient manner. It has been proposed that wavelet-based methods may be superior to currently used methods for the analysis of hyperspectral signatures. In this thesis, a wavelet-based method, as well as traditional analytical methods, was implemented and applied to hyperspectral images. The computational expense of the various methods …

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Ethical Climates In Lodging Operations: An Exploratory Study Of Management Perceptions, Todd Isaac Weinstein Jan 1999

Ethical Climates In Lodging Operations: An Exploratory Study Of Management Perceptions, Todd Isaac Weinstein

UNLV Retrospective Theses & Dissertations

This study explored the role of ethics in lodging organizations. Managers working at five different properties constituted the survey sample. The study examined management perceptions as measured by the Ethical Climate Questionnaire (ECQ). This instrument, used in previous research on moral reasoning, is designed to assess the perceptions of respondents based on three categories in two separate dimensions: ethical criteria (egoism, benevolence and principle) and loci of analysis (individual, local, and cosmopolitan). Each category comprises a separate ethical climate. Results from the ECQ were compared to various demographic variables such as gender, age, years of management experience, and number of …

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Automated Stenosis Quantification In Coronary Arteriograms, Yu Zhang Jan 1999

Automated Stenosis Quantification In Coronary Arteriograms, Yu Zhang

UNLV Retrospective Theses & Dissertations

Computer-assisted techniques have been shown to be useful in estimating the diameter and cross-sectional area of coronary artery lesions. In this study, two different strategies are employed for identification of artery contours, i.e., scanning and tracKing The scanning approach is accomplished by a canny edge detector. The edge tracking approach is in favor due to its low variability and fast analysis time. Given a start point and search direction, a tracking process automatically detects the arteries edge. From the edge points, a quantitative analysis process calculates the arteries diameter and percent diameter stenosis. As the software runs within a second, …

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The Use Of Continuum Models For Conducting Both Linear And Nonlinear Analyses Of Lattice Structures, Simon Yi Luk Jan 1999

The Use Of Continuum Models For Conducting Both Linear And Nonlinear Analyses Of Lattice Structures, Simon Yi Luk

UNLV Retrospective Theses & Dissertations

Large structural projects, such as lattices for framing tall buildings or space purpose can result in huge finite element models. The use of continuum methodology for conducting both linear and nonlinear analyses of lattice structures in finite-element models results in significantly fewer degrees of freedom than discrete finite-element models, which individually model each structural element. Hence, the use of continuum models can result in a considerable reduction in computational effort with a corresponding savings in cost, at least during early 1990s when Pentium computer was not available. Now, it can still be a good design method especially for tall buildings …

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Midpoint Estimation Applied To The Vertical-Horizontal Illusion, Gary Wayne Ogren Jan 1999

Midpoint Estimation Applied To The Vertical-Horizontal Illusion, Gary Wayne Ogren

UNLV Retrospective Theses & Dissertations

Eighty-three college undergraduates estimated midpoints of vertical lines presented in cued (a letter or figure presented below the line), uncued, and inverted T conditions. Subject's mean estimates were near the geometric midpoint in the two cued conditions, and significantly above the midpoint in the uncued and inverted T conditions. Mean estimates in the inverted T conditions were significantly above those in the uncued condition. These displacements are discussed in relation to previous midpoint estimation findings and theoretical explanations of the vertical-horizontal illusion. The midpoint estimation task is evaluated as an investigative tool in studies of geometric-optical illusions, and recommendations for …

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Responses Of Python Regius To Animal Chemosensory Stimuli: Implications Of Foraging Ecology, Albert Klein Jan 1999

Responses Of Python Regius To Animal Chemosensory Stimuli: Implications Of Foraging Ecology, Albert Klein

UNLV Retrospective Theses & Dissertations

Python regius is considered to be a sit-and-wait forager and has been reported to attempt capture of live and dead homeothermic prey. This preference for homeothermic prey may be innate and is not dependent on thermal cues. Chemosensory stimuli appear to be the only stimuli which may indicate to P. regius the metabolic group that a dead prey item at room temperature item may belong to. Snakes were exposed to novel odors from homeothermic and poikilothermic animals. Prey Searching Behavior (amount of locomotion) and Information Gathering Behavior (tongue flicking) were observed. Habituation to odors resulted in decreased behaviors. Odors of …

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A 3-Dimensional H-Adaptive Algorithm For Groundwater Flow And Contaminant Transport, Lan Li Jan 1999

A 3-Dimensional H-Adaptive Algorithm For Groundwater Flow And Contaminant Transport, Lan Li

UNLV Retrospective Theses & Dissertations

The simulation of contaminant transport through the subsurface is a very useful way to effectively design mitigation methods for cleanup and prevention of the deterioration of groundwater; The GWADAPT3 code is developed using the finite-element method and mesh adaptation to simulate groundwater flow and contaminant transport. The formulation is based on the equations for conservation of mass, Darcy's law for an anisotropic medium, and the time-dependent species transport equations. Petrov-Galerkin weighting of the advection terms provides numerical stability. An explicit time marching scheme is used to solve the transient equations. By utilizing unstructured adaptive meshing, concentration is accurately resolved; Benchmark …

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A Comparison Of Fast And Slow Contraction Speeds Using Electromyography, Philip James Melhorn Jan 1999

A Comparison Of Fast And Slow Contraction Speeds Using Electromyography, Philip James Melhorn

UNLV Retrospective Theses & Dissertations

The purpose of this study was to determine if differences in EMG activity existed between fast and slow contraction speeds during isolated, one-armed biceps curls to muscle failure. Participants performed one set of biceps curls to muscular failure on two separate occasions at different contraction speeds. Constant load equal to 75% of 1RM was used for each test. The dependent variables were integrated EMG (iEMG), percent change in mean frequency, and time to muscular failure. Integrated EMG measurements revealed significantly greater muscle activity for the slow contractions (t = 4.76, p {dollar}<{dollar}.001). The time to muscular failure also showed significant differences having the fast contraction speed achieve muscle failure faster than the slow contraction speed (t = 5.23, p {dollar}<{dollar}.001). The comparison of frequency data failed to reach significance. A significant correlation (r =.514) was determined for iEMG and time to muscular failure. These results suggest that differences exist in iEMG and time to muscle failure between fast and slow contraction speeds.

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The Aerodynamic Response Of Airborne Discs, Timothy Lewis Mitchell Jan 1999

The Aerodynamic Response Of Airborne Discs, Timothy Lewis Mitchell

UNLV Retrospective Theses & Dissertations

A study has been conducted to characterize the flow over a free-flying disc. In this study, three types of discs are analyzed in a series of stationary experiments, and a single disc is analyzed in a spinning experiment. Two dimensionless parameters dominate the experiments, the Reynolds number and the tip speed ratio. The first experiment measured the lift and drag at varying angles of attack on a stationary disc. The second stationary experiment was a unique measurement of the center of lift of a disc as a function of velocity. The third stationary experiment was a tuft test to describe …

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A Heuristic Approach For Path Planning For Redundant Robots, George Petrescu Jan 1999

A Heuristic Approach For Path Planning For Redundant Robots, George Petrescu

UNLV Retrospective Theses & Dissertations

A new method to solve the trajectory generation for a redundant manipulator is proposed. It avoids traditional computationally intensive methods by relying on the human experience; The proposed method uses a fuzzy logic controller to generate the magnitude of the angles needed to move the end effector to the next target point. The inputs to the controller are the desired displacement of the end effector and the elements of the jacobian matrix that correspond to the considered joint, while the output is the angle magnitude of the joint needed to reach the target point; An algorithm is used to determine …

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Experimental Study Of Drying Of A Porous Medium At Sub-Residual Saturations, Adaikkalavan Kumar Sathappan Jan 1999

Experimental Study Of Drying Of A Porous Medium At Sub-Residual Saturations, Adaikkalavan Kumar Sathappan

UNLV Retrospective Theses & Dissertations

An experimental study has been conducted to understand the drying effects in sub-residual saturated systems. Different flow rates and isothermal wall temperatures were used in the experiments. In two experimental runs, the test section was maintained at room temperature and gas flow initiated. Four other cases were started initially with heating up the porous medium with no flow, and then letting nitrogen gas flow through the test-section after a steady-state temperature distribution had been reached (denoted in what follows as the "steady heating case"); Temperatures throughout the bed and entering and exiting humidity values as a function of time among …

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Soluble Mineral Content Of Soils Using Electrical Conductivity, Merrill Gene Schweppe Jan 1999

Soluble Mineral Content Of Soils Using Electrical Conductivity, Merrill Gene Schweppe

UNLV Retrospective Theses & Dissertations

Soils with soluble salts occur in semi-arid and arid regions worldwide. The soluble mineral percentage of soil is determined by measuring the weight lost by diluting the soil mass with a fixed quantity of water. Correct estimation of soluble mineral content is made at the point of unsaturation. In the absence of clay, grain size does not affect determination of electrical conductivity for soils. Measurement of the electrical conductivity for a series of dilution ratios provides a reliable means of determining the correct dilution ratio. Measurement of the electrical conductivity of a subset of low water-soil dilution ratios and a …

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Classification Of Galaxies Using Fractal Dimensions, Sandip G Thanki Jan 1999

Classification Of Galaxies Using Fractal Dimensions, Sandip G Thanki

UNLV Retrospective Theses & Dissertations

The classification of galaxies is morphological. Shapes of the galaxies range from the very simple (e.g. elliptical galaxies) to the highly complex (e.g. irregular galaxies). Analyzing a measure of complexity for such shapes could lead to automatic classification. Fractal dimension, a quantity related to the complexity of a given shape, could be such a measure. Capacity dimension and correlation dimension are two of the several types of fractal dimensions. In this project, correlation dimensions and the capacity dimensions of the contours generated around different intensity levels of the galaxy images, versus the intensity levels were computed. It was found that …

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Impacts Of Stock Prices And Interest Rates On Tourism Consumption, Ming-Chih Tsai Jan 1999

Impacts Of Stock Prices And Interest Rates On Tourism Consumption, Ming-Chih Tsai

UNLV Retrospective Theses & Dissertations

Tourism industry has emerged as a leader in the U.S.'s service economy in the last decade. Meanwhile, stock markets and interest rates have been playing a more important role in Americans everyday lives. Prior research mainly focused on the economic impact of travel and tourism industry, but there are very few studies regarding how changes in economic factors will affect domestic tourism industry. This study focuses on measuring the impacts of stock prices and interest rates on tourism consumption. The results of this study show that stock prices and interest rates do have a certain amount of impacts on people's …

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Control Of Flexible Joint Robotic Manipulator Using Tuning Functions Design, Pavan Krishna Aripirala Venkata Jan 1999

Control Of Flexible Joint Robotic Manipulator Using Tuning Functions Design, Pavan Krishna Aripirala Venkata

UNLV Retrospective Theses & Dissertations

The goal of this thesis is to design the controller for a single arm manipulator having a flexible joint for the tracking problem in two different cases. A controller is designed for a deterministic case wherein the plant parameters are assumed to be known while another is designed for an adaptive case where all the plant parameters are assumed to be unknown. In general the tracking problem is; given a smooth reference trajectory, the end effector has to track the reference while maintaining the stability. It is assumed that only the output of the manipulator, which is the link angle, …

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Modeling Of Short-Distance Running, Maria Camille Theresa Jose Capiral Jan 1999

Modeling Of Short-Distance Running, Maria Camille Theresa Jose Capiral

UNLV Retrospective Theses & Dissertations

In this thesis, we construct a model of human performance in short distance foot races. First, we describe the Hill-Keller model of competitive running, based on the solution to an optimal control problem, and then focus on that part of the model dealing with short distance races. Our task is to estimate two underlying physiological parameters that characterize the runner's performance. Second, we customize this submodel by linearizing Keller's analytical solution for short distance races, we then apply a high quality linear least squares estimation based on the Singular Value Decomposition (SVD) in order to estimate the two physiological parameters. …

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Theoretical Study Of Mbe Growth Of Indium Gallium Arsenide Semiconductor Compound On Gallium Arsenide Substrate, Golshan Colayni Jan 1999

Theoretical Study Of Mbe Growth Of Indium Gallium Arsenide Semiconductor Compound On Gallium Arsenide Substrate, Golshan Colayni

UNLV Retrospective Theses & Dissertations

The theoretical study of Molecular Beam Epitaxy allows us to model and construct an experiment with the same conditions. Growth modeling investigates compound semiconductor characteristics during the MBE growth which can achieve the best results to control the quality of growth. Growth modeling also is less expensive and faster than experiments. The wide variation in the band-gap and lattice constants between InAs and GaAs is a subject for a variety of optical and electronic device applications involving InGaAs/GaAs systems. In this material system, the perfection is intrinsically controlled by the surface segregation of In due to its larger atomic size …

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Fluid Flow And Slope Stability Model, Gene Cotner Jan 1999

Fluid Flow And Slope Stability Model, Gene Cotner

UNLV Retrospective Theses & Dissertations

The objective of this work was to develop a computer model to calculate the changes in factor of safety of a slope with time resulting from changes in the water saturation. A two-phase fluid flow model was incorporated to calculate the saturation and saturation changes in fractured and nonfractured soil and rock. A slope stability model was created to calculate the factor of safety. The fluid flow module executes for every time interval specified by the user. The slope stability module is executed at the end of any time interval when desired. As examples, factors of safety for the downstream …

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The Relationship Between Casino Drop And Gaming Stock Performance: A Multivariate Analysis, Mark H Gilbert Jan 1999

The Relationship Between Casino Drop And Gaming Stock Performance: A Multivariate Analysis, Mark H Gilbert

UNLV Retrospective Theses & Dissertations

In reference to the gaming industry, investors and analysts examine many different variables that affect the financial viability of the business. Areas of investigation have included competition, governmental regulation, debt structure, cash flow, visitor volume, and so on; The purpose of this study was to analyze the relationship of yet another variable of casino performance, the casino drop, to gaming stock performance. Utilizing statistics provided from the State of Nevada's Gaming Revenue Report, the casino drop was divided into five segments, blackjack, craps, baccarat, quarter slots, and dollar slots; Tested by using a multiple regression analysis against a market capitalization-weighted …

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Do Rna-Dependent Polymerases Share Common Ancestry? A Bioinformatic Approach, Julianna Hudak Jan 1999

Do Rna-Dependent Polymerases Share Common Ancestry? A Bioinformatic Approach, Julianna Hudak

UNLV Retrospective Theses & Dissertations

Bioinformatics is the use of computational methods to perform hypothesis-driven research that generates new knowledge from existing biological databases. For any bioinformatic analysis, it is important that the most accurate method(s) be used. The first portion of this thesis is a comparative evaluation of six programs designed for the local alignment of protein sequences. The results demonstrate that two of the programs, MEME and PROBE, outperform all other programs (BLOCKMAKER, ITERALIGN, MATCHBOX, and PIMA). The second portion of this thesis uses MEME and PROBE in an attempt to locate an ordered-series-of-motifs (OSM) among two groups of RNA-dependent polymerases, the large …

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A Parametric Study On The Contained Burning Of Solid Rocket Motor Propellant, Jennifer Erin Politano Jan 1999

A Parametric Study On The Contained Burning Of Solid Rocket Motor Propellant, Jennifer Erin Politano

UNLV Retrospective Theses & Dissertations

Outmoded solid rocket motor propellant is being destroyed by burning as part of the worldwide demilitarization process. Many of these bums have been performed in spaces where the combustion products are contained within a sealed chamber. There is currently no accepted method to predict the gas temperature and pressure that results from this process. The primary focus of this study was the prediction of the peak temperature and pressure of the gas inside an underground containment chamber as a function of the propellant consumed and the prediction of the wall surface temperature as a function of time; A thermodynamic lumped …

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The Selection And Preparation Of Paramedic Preceptors In Emergency Medical Services, Brian James Tilton Jan 1999

The Selection And Preparation Of Paramedic Preceptors In Emergency Medical Services, Brian James Tilton

UNLV Retrospective Theses & Dissertations

In Emergency Medical Services, training programs for paramedics, providers of Advanced Life Support emergency care, include a field internship where students are partnered with a preceptor for training and evaluation before program completion; The purpose of this study was to determine if certain attributes could be used as predictors for preceptor success measured by a preceptor performance evaluation. The quantitative descriptive, correlation study was based on data gathered from paramedic preceptors in Clark County, Nevada in the spring of 1999. The sample (n = 66) was drawn through a consensus survey of every paramedic preceptor employed by a provider agency …

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Using Cottonwoods As Indicators Of Past Floods Along A Gravel-Bedded Stream, Edward A. Watson Jan 1999

Using Cottonwoods As Indicators Of Past Floods Along A Gravel-Bedded Stream, Edward A. Watson

Graduate Student Theses, Dissertations, & Professional Papers

No abstract provided.

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