Physical Sciences and Mathematics Commons^™

Ecology, Economy And Ecotourism: Sustaining People And The Environment, Richard Snow

Masters Theses & Specialist Projects

Tourism is the world's largest industry. The fastest growing segment of the travel and tourist trade is ecotourism. The concept of sustainable development insists that humans cooperate with nature in the search for an ecological economy which can support present and future populations. Ecotourism attempts to attain this elusive goal by preserving ecosystems while generating revenue for local communities. In this study, the researcher examines the positive and negative effects of ecotourism on people, culture, and landscape. An analysis of tourism data seems to suggest that developing countries, which are popular ecotour destinations, are benefitting economically and ecologically from properly …

Environmentalism In The United States: An Evolving Perspective, Mary Snow

Masters Theses & Specialist Projects

The purpose of this study is to investigate environmentalism in the United States. The dimension of perspective receives considerable attention. The prevailing perspective by a society regarding the importance of the health of the natural world greatly influences the degree of support of environmental organizations, environmental policy, as well as the direction charted for the future of that society. The perspectives of the Native Americans and the dominant European cultures which arrived in North America are presented and contrasted. It is supposed that the perspective which prevails in the United States regarding the importance of the natural world is evolving. …

Trace Element Analysis Of Selected Springs In The Virgin River Basin, Mary A. Yelken

UNLV Theses, Dissertations, Professional Papers, and Capstones

Spring water from 23 springs in and near the Virgin River Basin (southwestern Utah, northwestern Arizona, and southeastern Nevada) was collected and analyzed for chemical concentrations. Trace elements and major ion chemistry was used to determine the potential for utilizing water chemistry to provide information on spring water source and flow pathways. Principal Component Analysis (PCA), rare earth element (REE) normalization patterns, and mineral equilibrium modeling (PHREEQE) techniques were used to analyze the data set. Four major spring water groups were displayed by the PCA, based on similarities in water chemistry. The analyses suggest that spring water chemistry is a …

Applications Of Optimal Control, Katherine Renee Fister

Doctoral Dissertations

In this dissertation, we investigate optimal control of partial and ordinary differential equations. We prove the existence of an optimal control for which the objective functional is maximized. The goal is to characterize the optimal control in terms of the solution of the optimality system. The optimality system consists of the state equations coupled with the adjoint equations. To obtain the optimality system we differentiate the objective functional with respect to the control. This process is applied to harvesting in a predator-prey parabolic system, to analyzing surface runoff in a parabolic problem, and to controlling the effect of the HIV …

Residence Time Of Groundwater Issuing From The South Rim Aquifer In The Eastern Grand Canyon, Jim Fitzgerald

UNLV Theses, Dissertations, Professional Papers, and Capstones

In the eastern Grand Canyon, secondary porosity created by north trending faults, folds, and breccia pipes, facilitates groundwater flow through the South Rim carbonate aquifer. Springs associated with the South Rim Aquifer have low ³H concentrations, [Ca²⁺]/[Mg²⁺] rations close to unity, and variable uranium concentrations. For a geochemical comparison, springs are subcategorized on the basis of geology and discharge. Type I springs are associated with high-angle normal faults and have high discharge rates. These springs discharge Ca²⁺ - Mg²⁺, HCO₃^- waters, have ³H concentrations <2 TR, and ²³⁴U/²³⁸U activity …

A Test Of An Alternate Calibration Matrix For Niosh Method 7300, Robert T. Vitek

Community & Environmental Health Theses & Dissertations

The purpose of this study was to determine if the analytical results (when determining cadmium, lead, and zinc concentrations) for air sample filters prepared and analyzed according to N:OSH Method 7300, differ significantly, from those obtained when the instrument is calibrated using EPA Method 200.7 acid matrix standards. The null hypothesis was that no statistically significant difference, measured at the 95% confidence level, would exist between results obtained from the two calibration standards. Careful standard and sample preparation, the use of an internal standard, and the application of working standard and working internal standard correction factors served to isolate the …

Influence Of Solvent On The Interfacial Structure Of Self-Assembled Alkanethiol Monolayers, Mark Anderson, Mark Evaniak, Minhui Zhang

Mark R. Anderson

Polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) is used to study the structure of octadecanethiol, tetradecanethiol, and decanethiol monolayers in the presence of air, deuterium oxide, and acetonitrile-d3. It is found that the structure of the monolayer is dependent on both the adjacent environment and the initial structural order of the monolayer. In the D2O solutions, spectral changes are similar for the three monolayers and are characteristic of interaction predominantly between the solvent and the terminal portion of the monolayers. This correlates with electrochemical capacitance measurements that indicate little permeation of the aqueous electrolyte in the monolayer, even with the …

Development And Evaluation Of Internet-Based Hypermedia Chemistry Tutorials, Brian Tissue, Ronald Earp, Ching-Wan Yip, Mark Anderson

Mark R. Anderson

This progress report describes the development and student use of World-Wide-Web-based prelaboratory exercises in senior-level Instrumental Analysis during the 1995 Fall semester. The laboratory preparation exercises contained hypermedia tutorials and multiple-choice questions that were intended to familiarize the students with the experiments and instrumentation before their laboratory session. The overall goal of our work is to explore ways in which computer and network technology can be applied in education to improve the cost-effectiveness and efficacy of teaching. The course material can be accessed at http://www.chem.vt.edu/chem-ed/4114/Fall1995.html.

Our Common Future, American Style (Reviewing President’S Council On Sustainable Development, Sustainable America (1996)), John C. Dernbach

John C. Dernbach

No abstract provided.

An International Study Of Intensity In Talented Teenagers Using The Overexcitability Questionnaire (Oeq), John Fraas, Jane Piirto, Geri Cassone, Cheryl Ackerman

John W. Fraas

No abstract provided.

An Optical And X-Ray Study Of Abell 576, A Galaxy Cluster With A Cold Core, Joseph J. S. Mohr, Margaret J. Geller, Daniel G. Fabricant, Gary Wegner, John Thorstensen, Douglas O. Richstone

Dartmouth Scholarship

We analyze the galaxy population and dynamics of the galaxy cluster A576; the observational constraints include 281 redshifts (230 new), R- band CCD galaxy photometry over a 2 h^-1^ Mpc x 2 h^-1^ Mpc region centered on the cluster, an Einstein IPC X-ray image, and an Einstein MPC X-ray spectrum. We focus on an 86% complete magnitude-limited sample (R_23.5_ < 17) of 169 cluster galaxies. The cluster galaxies with emission lines in their spectra have a larger velocity dispersion and are significantly less clustered on this 2 h^-1^ Mpc scale than galaxies without emission lines. We show that excluding the emission-line galaxies from the cluster sample decreases the velocity dispersion by 18% and the virial mass estimate by a factor of 2. The central cluster region contains a nonemission galaxy population and an intracluster medium which is significantly cooler (σ_core_ = 387_-105_^+250^ km s^-1^ and T_x_ = 1.6_-0.3_^+0.4^ keV at 90% confidence) than the global populations (σ = 977_-96_^+124^ km s^- 1^ for the nonemission population and T_X_ > 4 keV at 90% confidence). Because (1) the low-dispersion galaxy population is no more luminous than the global population and (2) the evidence for a cooling flow is weak, we suggest that the core of A576 may contain the remnants of …

Nmr Study Of Neurophysin Dimer Dissociation By Cosolvents, Jian Yao

Dissertations and Theses

Neurophysins (NPs) make up a relatively small, stable, and highly soluble class of proteins. They have physiological roles of storage and stabilizing' of peptide hormones oxytocin and vasopression within the posterior pituitary neurosecretory granules. At the concentration of NP found within the granules, NP would exist as a dimer in the absence or presence of bound peptide. The NP monomer-monomer interface involves B-sheet/ B-sheet contact, which can be modulated by the presence of cosolvent. This remarkable feature of NP makes it a model for Alzheimer's disease. One of the characteristics of Alzheimer's disease is the presence of plaques of B-amyloid …

Absence Of Open Strings In A Lattice-Free Simulation Of Cosmic String Formation, Julian Borrill

Dartmouth Scholarship

Lattice-based string formation algorithms can, at least in principle, be reduced to the study of the statistics of the corresponding aperiodic random walk. Since in three or more dimensions such walks are transient, this approach necessarily generates a population of open strings. To investigate whether open strings are an artifact of the lattice we develop an alternative lattice-free simulation of string formation. Replacing the lattice with a graph generated by a minimal dynamical model of a first-order phase transition we obtain results consistent with the hypothesis that the energy density in string is due to a scale-invariant Brownian distribution of …

Wavelet Nonparametric Regression With Dependent Data, Chengjie Xiong, George A. Milliken

Conference on Applied Statistics in Agriculture

Estimation of the regression function has many applications in agriculture and industry. Usually, the regression function is assumed a known functional form which depends on unknown parameters. Nonparametric regression theory makes no such assumption and often uses some kernel functions to form the so-called Watson Nadaraya type estimators. Such estimators were extensively studied by Watson (1964), Nadaraya (1964, 1989) and Collomb (1981, 1985). When the data are independent, these estimators have nice asymptotic convergence properties. When the data are dependent, Gyorfi et al (1989) gave some large sample properties for the Watson-Nadaraya estimators. In this paper, the recently developed theory …

Validity Of 95% T-Confidence Intervals Under Some Transect Sampling Strategies, Stephen N. Sly, Jeffrey S. Pontius, James J. Higgins

Conference on Applied Statistics in Agriculture

Soil pH data were used to assess the capture rates of 95 % t-confidence intervals based on five different transect sampling strategies. Two different sampling methods were considered, "deterministic" and "two-stage simple random sampling". The data used were pH readings at 15 and 30 centimeter depths from two local agricultural fields in the Manhattan, Kansas area. The data provided three distinct populations with three different distributions - skewed left, symmetric, and bimodal. The total number of transects randomly sampled was 2, 5, and 10. The total number of points sampled along each transect was 2, 7 and 14. The 95% …

Designing Speech Interface Applications For Acquisition Of Agricultural Information, Jeffrey Willers, Susan Bridges, Xiaofeng Ma, James Mckinion, Jean Liang

Conference on Applied Statistics in Agriculture

It will be argued that customary software design strategies, by themselves, fall short when designing speech recognition applications. Concepts of experimental design and analysis are also necessary for developing speech interface software. This study demonstrates that these tools can be advantageous to the software developer, especially if the prototype methodology model of software development is applied. A case study for the problem of developing a speech interface for collecting, or mapping, information on cotton plant growth is presented. The acquisition of cotton plant map data is a 'hands and eyes' busy task that requires considerable investment to record and convert …

A New Approach To Teaching Natural Resource Sampling, Kenneth M. Portier, Loukas G. Arvanitis, Daniel Brackett

Conference on Applied Statistics in Agriculture

A basic undergraduate course in statistics is often not adequate for students in renewable natural resource programs such as wildlife, forestry, fisheries, and related subjects. A strong foundation in the basics of sampling in time and space of forest, vegetation, wildlife and fish populations is needed. A brief account of our experience in teaching such a course over the last three years along with progress on developing course-related material and activities is reported. This includes the development of: 1) computer-based simulations; 2) in-class participation simulations to illustrate the basic concepts of sampling in space and time; 3) exercises to introduce …

Experimentation Science: A Process Approach For The Complete Design Of An Experiment, D. D. Kratzer, K. A. Ash

Conference on Applied Statistics in Agriculture

Experimentation Science is introduced as a process through which the necessary steps of experimental design are all sufficiently addressed. Experimentation Science is defined as a nearly linear process of objective formulation, selection of experimentation unit and decision variable(s), deciding treatment, design and error structure, defining the randomization, statistical analyses and decision procedures, outlining quality control procedures for data collection, and finally analysis, presentation and interpretation of results. The protocol description form (PDF) is introduced as an instrument to guide the implementation and documentation of the Experimentation Science process.

Markov Chain Monte Carlo Methods For Modeling The Spatial Pattern Of Disease Spread In Bell Pepper, Jonathan M. Graham

Conference on Applied Statistics in Agriculture

With exponential family models for dependent data, such as the autologistic model for binary spatial lattice data, maximum likelihood estimates can be obtained using Markov chain sampling methods by simulating an ergodic Markov chain which converges weakly to the equilibrium distribution of the model. This Markov chain Monte Carlo maximum likelihood (MCMCML) procedure provides a competitor to the usual pseudolikelihood estimation method often used for modeling discrete lattice data. Within this MCMCML framework, it is also possible to conduct formal inference using MCMC analogues to the usual likelihood ratio, Wald, and Lagrange multiplier tests, for which the asymptotic distributions are …

Confidence Intervals For The Coefficient Of Variation, Mark E. Payton

Conference on Applied Statistics in Agriculture

The coefficient of variation (CV), defined as the ratio of the standard deviation to the mean, is often used in experimental situations. The exact distribution of the sample CV from a normally distributed population is complicated and obtaining a confidence interval for the population CV in this situation would require using the non-central t distribution and sequential techniques (Koopmans, et al., 1964). This paper explores the use of approximate distributions in determining confidence limits for the CV. The gamma distribution is used to model data appropriate for the calculation of the CV. A Monte Carlo simulation is performed to evaluate …

Estimation Of Kinetic Parameters Associated With Nutrient Uptake By An Intact Plant Root System, Edward Gbur, Craig Beyrouty

Conference on Applied Statistics in Agriculture

Several mechanistic models have been developed for the prediction of nutrient uptake at low concentrations from the soil by a plant root system. Claassen and Barber (1974 Plant Physiology 54, 564-568; 1976 Agronomy Journal 68, 961-964) presented an experimental procedure to obtain data from intact plants to fit an ion depletion curve and used the data in a model which they developed to predict nutrient uptake. Their model assumed that nutrient absorption from the soil solution followed Michaelis-Menten kinetics. In this paper, we develop a stochastic version of the Claassen-Barber model and illustrate its application to the estimation of the …

Analysis Of Unbalanced Mixed Model Data: Traditional Anova Versus Contemporary Methods, Ramon C. Littell

Conference on Applied Statistics in Agriculture

Analysis of unbalanced data and analysis of mixed model data are important topics of statistical discussion. Analysis of unbalanced data with fixed effects gives rise to the different types of sums of squares in analysis of variance. Mixed model riata raises issues of determining appropriate error terms for test statistics and standard errors Clf estimates. The situation is even more difficult when the two topics occur together, resulting in unbalanced mixed model data. These problems have plagued users ofPROC GLM in the SAS System. Now, with PROC MIXED available, some of the problems are resolved while others remain. This paper …

Analysis Of Proportions From Split-Plot And Repeated Measures Experiments, Kenneth J. Koehler

Conference on Applied Statistics in Agriculture

Several methods for analyzing proportions from split-plot and repeated measures experiments are illustrated and compared. One approach simply uses analysis of variance for the usual linear mixed model fit to split-plot and repeated measures experiments. Alternatively, logistic regression analysis is considered and a so-called robust estimate of the covariance matrix is used to adjust for possible correlations among responses. Finally, a quasi-likelihood approach to logistic regression analysis that requires more explicit specification of the covariance structure for the observed proportions is considered. These methods are illustrated with the analyses of data from a repeated measures study of acorn consumption by …

Estimation Of Cardinal Temperatures In Germination Data Analysis, Cindy Roche, Bahman Shafii, Donald C. Thill, William J. Price

Conference on Applied Statistics in Agriculture

Seed germination is a complex biological process which is influenced by various environmental and genetic factors. The effects of temperature on plant development are the basis for models used to predict the timing of germination. Estimation of the cardinal temperatures, including base, optimum, and maximum, is essential because rate of development increases between base and optimum, decreases between optimum and maximum, and ceases above the maximum and below the base temperature. Nonlinear growth curves can be specified to model the time course of germination at various temperatures. Quantiles of such models are regressed on temperature to estimate cardinal quantities. Bootstrap …

Long-Term Tillage Effects On Continuous Corn Yields, T. B. Bailey, J. B. Swan, R L. Higgs, W. H. Paulson

Conference on Applied Statistics in Agriculture

Long-term comparisons of alternative tillage systems are needed to evaluate their effect on corn (Zea mays L.) yield under the variable temperature and rainfall conditions of the Corn Belt. Our objective was to evaluate long-term effects of alternative tillage systems on corn growth and yield on low organic matter silt loam soils. The effect of no-tillage (NT), chisel plow (CP), and moldboard plow (MP) treatments on plant density and grain yield was measured from 1981 through 1990 on Palsgrove and Rozetta silt loam (fine-silty, mixed mesic Typic Hapludalfs) soils. Tillage treatments were randomly allocated to plots in 1981 …

An Introduction To Generalized Linear Mixed Models, Charles E. Mcculloch

Conference on Applied Statistics in Agriculture

The generalized linear mixed model (GLMM) generalizes the standard linear model in three ways: accommodation of non-normally distributed responses, specification of a possibly non-linear link between the mean of the response and the predictors, and allowance for some forms of correlation in the data. As such, GLMMs have broad utility and are of great practical importance. Two special cases of the GLMM are the linear mixed model (LMM) and the generalized linear model (GLM). Despite the utility of such models, their use has been limited due to the lack of reliable, well-tested estimation and testing methods. I first describe and …

Editor's Preface, Table Of Contents, And List Of Attendees, George A. Milliken

Conference on Applied Statistics in Agriculture

These proceedings contain papers presented in the eighth annual Kansas State University Conference on Applied Statistics in Agriculture, held in Manhattan, Kansas, April 28-30, 1996..

Iowa Academy Of Science President's Banquet [108th Session], Iowa Academy Of Science

Iowa Academy of Science Documents

Program:

Introductions
Awards:
Distinguished Fellow: Jerald Schnoor
Distinguished Iowa Scientist: David Benn
Distinguished Service: Paul Christiansen
Distinguished Iowa Science Teaching: Neil Bernstein
President's Address - Ross Iverson
Response - Bill Gilbert, President-Elect
General Sessions II - Dr. John Croat, "The Evolution & Technological Significance of the Modern Permanent Magnet"

Critical Pressures In Multicomponent Lipid Monolayers, John P. Hagen, Harden M. Mcconnell

Chemistry and Biochemistry

Epifluorescence microscopy has been used previously to study coexisting liquid phases in lipid monolayers of dihydrocholesterol and dimyristoylphosphatidylcholine at the air/water interface. This binary mixture has a critical point at room temperature (22°C), a monolayer pressure of approx. 10 mN/m, and a composition in the vicinity of 20-30 mol% dihydrocholesterol. It is reported here that this critical pressure can be lowered, raised, or maintained constant by systematically replacing molecules of this phosphatidylcholine with molecules of a phosphatidylethanolamine, or an unsaturated phosphatidylcholine, or mixtures of the two, while maintaining the dihydrocholesterol concentration at 20 mol%. Thus, even complex mixtures of lipids …

Indirect Ultraviolet Detection Of Biologically Relevant Organic Acids By Capillary Electrophoresis, Hong Chen, Yan Xu, Frederick Van Lente, Michael P.C. Ip

Chemistry Faculty Publications

Indirect UV detection of fourteen short-chain organic acids (e.g., oxalic acid, citric acid, malonic acid, tartaric acid, methylmalonic acid, α-ketoglutaric acid, succinic acid, ethylmalonic acid, methylsuccinic acid, glutaric acid, apidic acid, methylglutaric acid, lactic acid and pyruvic acid) by capillary electrophoresis is described. The method used phthalate as the UV-absorbing additive in carbonate buffer and the non-absorbing analytes were detected indirectly at 230 nm. The influences of buffer pH, ionic strenght, concentration of phthalate and organic modifier on indirect signal response and migration behavior of the organic acids were investigated. Comparisons of reproducibility on migration time, limit of detection and …