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2016

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Full-Text Articles in Physical Sciences and Mathematics

A Pes Study Of Factors Influencing Metal Partitioning In Aquatic Systems: “Design Of Experiment As, Cd, Co, Cr, Cu, Pb, Ni, And Zn”, Eid A. Alkhatib, John Rapaglia, Leon Theim Dec 2016

A Pes Study Of Factors Influencing Metal Partitioning In Aquatic Systems: “Design Of Experiment As, Cd, Co, Cr, Cu, Pb, Ni, And Zn”, Eid A. Alkhatib, John Rapaglia, Leon Theim

Chemistry & Physics Faculty Publications

Mobility and bioavailability of heavy metals are related to their partitioning amongst suspended sediment and water. A Particle Entrainment Simulator (PES) is used to simulate sediment resuspention in natural surface water systems. The simulations were carried out under various conditions of water/suspended solids conditions. Five factors, each at various levels, are tested collectively: the pH of water at two levels (4 and 8), shear stress on bottom sediment at three levels (0.1, 0.3, and 0.5 N/m2 ) salinity of water at two levels (0.01 and 14.0 ppt), organic matter in sediment at three levels (0.50, 1.93, and 3.80%) and temperature …


Progression Magazine, 2016 Winter, Coastal Carolina University Dec 2016

Progression Magazine, 2016 Winter, Coastal Carolina University

Progression Magazine

Magazine of the College of Science at Coastal Carolina University.


A Comparison Of Online And Face-To-Face Achievement In Physical Science, Lisa F. Mozer Dec 2016

A Comparison Of Online And Face-To-Face Achievement In Physical Science, Lisa F. Mozer

Doctor of Education in Instructional Technology Dissertations

ABSTRACT

This study provided a descriptive analysis of learning outcomes in both online and face-to-face grades 9-12 physical science courses. Archived data from a single school system were used for a comparative analysis of learning outcomes in high school physical science between students enrolled in online classes and students enrolled in face-to-face classes. The study compared two years of summative assessment scores of two student groups and, overall, found equality between the two learning environments. Online learning outcomes and face-to-face learning outcomes were similar for both school years, 2013-2014 and 2014-2015. The overall comparison between learning environments was further examined …


High Order Harmonic Generation From Sf₆: Deconvolution Of Macroscopic Effects, B. P. Wilson, K. D. Fulfer, S. Mondal, X. Ren, J. Tross, E. D. Poliakoff, J. Jose, Anh-Thu Le, R. R. Lucchese, Carlos A. Trallero-Herrero Dec 2016

High Order Harmonic Generation From Sf₆: Deconvolution Of Macroscopic Effects, B. P. Wilson, K. D. Fulfer, S. Mondal, X. Ren, J. Tross, E. D. Poliakoff, J. Jose, Anh-Thu Le, R. R. Lucchese, Carlos A. Trallero-Herrero

Physics Faculty Research & Creative Works

We measure high order harmonics from the molecule SF₆ over a large range of phase matching conditions and observe several features in the harmonics that are largely independent of such macroscopic conditions. The experimental data are then compared to the quantitative rescattering theory for the generation of harmonics from three orbitals. With this comparison, we are able to assign spectroscopic features in the harmonics to contributions from 1t1g (HOMO) and 5t1u (HOMO-1) orbitals.


Design And Synthesis Of Dynamic Covalent Polymer Scaffolds With Controlled Architectures, Emily Annette Hoff Dec 2016

Design And Synthesis Of Dynamic Covalent Polymer Scaffolds With Controlled Architectures, Emily Annette Hoff

Dissertations

The design and synthesis of functional, controlled polymer architectures is essential to the development of new materials with precise and tailorable properties or applications. The work described in this dissertation focuses on the development of controlled polymer architectures with dynamic linkages for the design of multifunctional materials and surfaces via robust, efficient, and stimuli-responsive strategies.

In Chapter III, a post-polymerization modification strategy based on ambient temperature nucleophilic chemical deblocking of polymer scaffolds bearing N-heterocycle blocked isocyanate moieties is reported. Room temperature RAFT polymerization of three azole-N-carboxamide methacrylates, including 3,5-dimethyl pyrazole, imidazole, and 1,2,4-triazole derivatives, afforded reactive polymer scaffolds …


Ground-Penetrating Radar Water Content Mapping Of Golf Course Green Sand Layers, Barry J. Allred, Robert S. Freeland, Katherine R. Grote, Edward L. Mccoy, Luis R. Martinez, Debra L. Gamble Dec 2016

Ground-Penetrating Radar Water Content Mapping Of Golf Course Green Sand Layers, Barry J. Allred, Robert S. Freeland, Katherine R. Grote, Edward L. Mccoy, Luis R. Martinez, Debra L. Gamble

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Information on the spatial distribution of water content across the sand layer component of a golf course green can be important to golf course superintendents for evaluating drainage effectiveness and scheduling irrigation. To estimate the bulk volumetric water content of the sand layer at point locations across the green, a technique was developed that combined (1) depth (or thickness) of the sand layer measured with a steel shaft tile probe, (2) radar signal two-way travel time from the base of the sand layer obtained using a ground-penetrating radar (GPR) system with 900 MHz antennas, and (3) an empirical equation relating …


Optical Spectroscopy And The Contruction Of An Optimal Wannier Basis With Application To The Development Of Ab Initio Models, Robert Gerard Van Wesep Dec 2016

Optical Spectroscopy And The Contruction Of An Optimal Wannier Basis With Application To The Development Of Ab Initio Models, Robert Gerard Van Wesep

Doctoral Dissertations

Understanding the role of local orbital degrees of freedom in the behavior of solid state systems has long been understood as a key to unraveling the mysteries presented by complex transition metal compounds. A general approach to the many-body problem is density functional theory (DFT) and its time-dependent extension (TDDFT), which provide a realistic representation of the material-dependent symmetry and chemistry of a compound. Calculation of quantities in (TD)DFT are most often performed using the basis of Bloch states, which is not natural for investigating local degrees of freedom. The Wannier basis provides localized orbitals that retain all of the …


Development And Validation Of The Statistics Assessment Of Graduate Students, Dammika Lakmal Walpitage Dec 2016

Development And Validation Of The Statistics Assessment Of Graduate Students, Dammika Lakmal Walpitage

Doctoral Dissertations

This study developed the Statistics Assessment of Graduate Students (SAGS) instrument, and established its preliminary item characteristics, reliability, and validity evidence. Even though there are limited number of assessments available for measuring different aspects of statistical cognition, these previously available assessments have numerous limitations. The SAGS instrument was developed using Rasch modeling approach to create a new measure of statistical research methodology knowledge of graduate students in education and other behavioral and social sciences. Thirty-five multiple-choice questions were written with stems representing applied research situations and response options distinguishing between appropriate use of various statistical tests or procedures. A focus …


Development Of An F-Element Separation Chemistry Using Solid Electrolytes, Kristian Guy Myhre Dec 2016

Development Of An F-Element Separation Chemistry Using Solid Electrolytes, Kristian Guy Myhre

Doctoral Dissertations

The f‒elements (lanthanides and actinides) have numerous applications and are critically important to many industries, including the energy, security, and medical industries. One of the barriers to increased use and availability of the f‒elements is the difficulty in separating them from each other due to their similar chemistries. This is especially true of the trivalent f‒elements (lanthanides and minor actinides). The development of separation techniques that maximize the differences in the physicochemical properties of the f‒elements is therefore an important area of research. For these reasons, an effort was undertaken to explore the use of solid …


Catalytic Aziridination With A Borate-Containing N-Heterocyclic Tetracarbene Iron Complex, Preeti Pradip Chandrachud Dec 2016

Catalytic Aziridination With A Borate-Containing N-Heterocyclic Tetracarbene Iron Complex, Preeti Pradip Chandrachud

Doctoral Dissertations

Aziridines, the nitrogen analog of epoxides, are an important class of compounds. They are present in many biologically active compounds having antibacterial and antitumor properties. Along with biological significance, it can also be considered as a synthetic tool for various functional group transformations. Being an important functional group we focused on the development of synthetic methodology using alkenes as substrates and organic azides as the nitrene source [C2 (carbon2)+ N1 (nitrogen1) addition reaction].

For the potential use as an aziridination catalyst a macrocyclic N-heterocyclic tetracarbene (NHC) ligand system was developed. First, the neutral NHC ligand was used …


Kinematic, Metamorphic, And Geochronologic Constraints On The Evolution Of The Lhagoi Kangri Gneiss Dome, Southern Tibet: Insight Into Mid-Crustal Processes During Himalayan Orogenesis, Timothy Francis Diedesch Dec 2016

Kinematic, Metamorphic, And Geochronologic Constraints On The Evolution Of The Lhagoi Kangri Gneiss Dome, Southern Tibet: Insight Into Mid-Crustal Processes During Himalayan Orogenesis, Timothy Francis Diedesch

Doctoral Dissertations

The north Himalayan gneiss domes are a series of isolated structures in southern-central Tibet that expose middle crust and record an early history of deformation, metamorphism, and partial melting. The domes are windows into the processes and physical conditions that promoted growth and uplift of the Himalaya during the early stage of collision (Eocene to Miocene) between India and Asia. Mechanisms responsible for creating the north Himalayan gneiss domes are crucial to understanding the early tectonic evolution of large orogens, such as the Himalaya, particularly with respect to crustal rheology and how middle crust is exhumed in collisional settings. Models …


Synthesis And Behavior Of Stimuli-Responsive Shape-Changing Linear Molecular Bottlebrushes, Daniel Mark Henn Dec 2016

Synthesis And Behavior Of Stimuli-Responsive Shape-Changing Linear Molecular Bottlebrushes, Daniel Mark Henn

Doctoral Dissertations

Molecular bottlebrushes are composed of polymer side chains densely grafted to a macromolecular backbone. The main focus of this dissertation work is the synthesis and behavior of linear molecular brushes that can undergo unimolecular size and shape changes in response to environmental stimuli in dilute aqueous solution. Chapter 1 provides an introduction to molecular bottlebrushes and stimuli-responsive polymers.

Chapter 2 presents the development of a robust method for the synthesis of well-defined molecular brushes by a “grafting to” approach using copper-catalyzed azide-alkyne cycloaddition “click” reactions. Well-defined, new azide-containing backbone polymers with different lengths and high degrees of azide functionality were …


Geomorphology, Stratigraphy, And Paleohydrology Of The Aeolis Dorsa Region, Mars, With Insights From Modern And Ancient Terrestrial Analogs, Robert Eric Jacobsen Ii Dec 2016

Geomorphology, Stratigraphy, And Paleohydrology Of The Aeolis Dorsa Region, Mars, With Insights From Modern And Ancient Terrestrial Analogs, Robert Eric Jacobsen Ii

Doctoral Dissertations

Ancient fluvial features on Mars evidence past episodes of hydrologic activity and paleoclimate conditions suitable for liquid water. The Aeolis Dorsa region preserves the most numerous and diverse assemblage of fluvial features yet observed on Mars and many of these features have experienced a history of burial, exhumation, and topographic inversion. This dissertation describes analyses of visual images and topography of Mars and complementary analyses of fluvial analogs on Earth. These analyses provide information about the styles of fluvial activity, magnitudes of paleodischarge, changes in slope, and inferences about Martian paleoclimate conditions. Results indicate that the Aeolis Dorsa deposits encapsulate …


On The Quantification Of Complexity And Diversity From Phenotypes To Ecosystems, Zachary Harrison Marion Dec 2016

On The Quantification Of Complexity And Diversity From Phenotypes To Ecosystems, Zachary Harrison Marion

Doctoral Dissertations

A cornerstone of ecology and evolution is comparing and explaining the complexity of natural systems, be they genomes, phenotypes, communities, or entire ecosystems. These comparisons and explanations then beget questions about how complexity should be quantified in theory and estimated in practice. Here I embrace diversity partitioning using Hill or effective numbers to move the empirical side of the field regarding the quantification of biological complexity.

First, at the level of phenotypes, I show that traditional multivariate analyses ignore individual complexity and provide relatively abstract representations of variation among individuals. I then suggest using well-known diversity indices from community ecology …


Persistent Organic Chemicals In The Pacific Basin Countries: An Overview, Bommanna G. Loganathan Dec 2016

Persistent Organic Chemicals In The Pacific Basin Countries: An Overview, Bommanna G. Loganathan

Faculty & Staff Research and Creative Activity

The Pacific Basin is a unique geographical region representing tropical, temperate and polar zones. This region is home to 2/3 of world’s population and consists of rapidly growing economies (countries) and highly developed countries. The Pacific Basin countries have had a history of use of persistent organic chemicals (POCs) at varying proportions during the last five decades. Due to diverse climatic and socio-economic conditions, the environment and biota in different countries in this basin have varying degrees of environmental contamination and effects on wildlife and humans. In this chapter, the historical background of POCs including, discovery, production, use, regulations/restrictions imposed, …


How Do Designers Of The Built Environment Attempt To Make Ecological Sustainability Sensory Legible?, Carly L. Bartow Dec 2016

How Do Designers Of The Built Environment Attempt To Make Ecological Sustainability Sensory Legible?, Carly L. Bartow

Architecture Undergraduate Honors Theses

This paper attempts to provide a theoretical framework for making ecosystem function and ecologically sustainable design more perceptible or sensible to people through architecture and the built environment. Design features of the Bertschi School Science Wing and the Bullitt Center in Seattle, Washington are incorporated to illustrate the sensory legibility of ecological sustainability criteria.The criteria are available to designers to help educate a building's occupants on environmentally sustainable design and motivate more sustainable behavior.


Modeling The Effects Of Tile Drain Placement On The Hydrologic Function Of Farmed Prairie Wetlands1, Brett Werner, John Tracy, W. Carter Johnson, Richard A. Voldseth, Glenn R. Guntenspergen, Bruce Millett Dec 2016

Modeling The Effects Of Tile Drain Placement On The Hydrologic Function Of Farmed Prairie Wetlands1, Brett Werner, John Tracy, W. Carter Johnson, Richard A. Voldseth, Glenn R. Guntenspergen, Bruce Millett

United States Geological Survey: Staff Publications

The early 2000s saw large increases in agricultural tile drainage in the eastern Dakotas of North America. Agricultural practices that drain wetlands directly are sometimes limited by wetland protection programs. Little is known about the impacts of tile drainage beyond the delineated boundaries of wetlands in upland catchments that may be in agricultural production. A series of experiments were conducted using the well-published model WETLANDSCAPE that revealed the potential for wetlands to have significantly shortened surface water inundation periods and lower mean depths when tile is placed in certain locations beyond the wetland boundary. Under the soil conditions found in …


Resource Assessment Report Western Rock Lobster Resource Of Western Australia, Simon De Lestang, Nick Caputi, Jason How Dec 2016

Resource Assessment Report Western Rock Lobster Resource Of Western Australia, Simon De Lestang, Nick Caputi, Jason How

WA Marine Stewardship Council report series

The western rock lobster Panulirus cygnus (George) is taken by commercial and recreational fishers throughout its geographic range along the lower west coast of Western Australia. The main commercial fishery for P. cygnus is the West Coast Rock Lobster Managed Fishery (WCRLMF), which is Australia’s largest single-species fishery, currently worth about $400 million annually. Western rock lobster provides the basis for the economies of a number of coastal towns and also supports a recreational fishery.


Finding The Best Remaining Black Hills Montane Grasslands, The First Step In Conservation, Hollis Marriott, Don Faber-Langendoen, David J. Ode Dec 2016

Finding The Best Remaining Black Hills Montane Grasslands, The First Step In Conservation, Hollis Marriott, Don Faber-Langendoen, David J. Ode

The Prairie Naturalist

Black Hills Montane Grassland is a rare and endangered plant community endemic to the Black Hills of western South Dakota and northeastern Wyoming. It is restricted to higher elevations on the Limestone Plateau in the western part of the uplift. Early visitors to the Black Hills wrote glowing reports of flower-filled grasslands on the Limestone Plateau. Lieutenant Colonel George A. Custer and his soldiers reveled in lush grass, and decorated the headgear of their horses with flowers (Custer 1875). Expedition botanist A. B. Donaldson “estimated the number of flowers in bloom in Floral Valley at 50, while an equal number …


Assessment Of Smallmouth Bass Growth And Mortality In Nebraska Waters, Benjamin J. Schall, Keith D. Koupal, Casey W. Schoenebeck, Keith L. Hurley Dec 2016

Assessment Of Smallmouth Bass Growth And Mortality In Nebraska Waters, Benjamin J. Schall, Keith D. Koupal, Casey W. Schoenebeck, Keith L. Hurley

The Prairie Naturalist

Smallmouth bass (Micropterus dolomieu) have been introduced across Nebraska into a variety of waterbodies. However, an estimate of smallmouth bass growth and mortality in Nebraska waters has not been produced. The objectives of this study were to use historic sampling data to describe the growth of smallmouth bass in Nebraska lakes in relation to other regional models, growth among waterbody types (reservoirs, Interstate 80 [I-80] lakes, and rivers), estimates of age at quality, preferred, and memorable lengths, and mortality for Nebraska smallmouth bass populations. Mean length ± SE of Nebraska smallmouth bass at age 7 was 383 ± …


Review Of Booming From The Mists Of Nowhere: The Story Of The Greater Prairie-Chicken By Greg Hoch, Ross H. Hier Dec 2016

Review Of Booming From The Mists Of Nowhere: The Story Of The Greater Prairie-Chicken By Greg Hoch, Ross H. Hier

The Prairie Naturalist

The Greater Prairie-Chicken (Tympanuchus cupido pinnatus) is an iconic species inhabiting one of the most iconic and rarest habitats in the world—the tallgrass prairies of central North America. To tell the story of the Greater Prairie-Chicken is a monumental task. Its history is intricately woven into pre- and post-European settlement of the North American prairies in such a way that knowledge of the species is spread over several centuries. Thus, researching the “old and the new” regarding the Greater Prairie-Chicken requires a substantial literature review, much of which occurs in publications from the 1800s. Hoch has done a …


Environmental Emission Of Pharmaceuticals From Wastewater Treatment Plants In The Usa, Bikram Subedi, Bommanna G. Loganathan Dec 2016

Environmental Emission Of Pharmaceuticals From Wastewater Treatment Plants In The Usa, Bikram Subedi, Bommanna G. Loganathan

Faculty & Staff Research and Creative Activity

The residual drugs, drug bioconjugates, and their metabolites, mostly from human and veterinary usage, are routinely flushed down the drain, and enter wastewater treatment plants (WWTP). Increasing population, excessive use of allopathic medicine, continual introduction of novel drugs, and existing inefficient wastewater treatment processes result in the discharge of large volumes of pharmaceuticals and their metabolites from the WWTPs into the environment. The effluent from the WWTPs globally contaminate ~25% of rivers and the lakes. Pharmaceuticals in the environment, as contaminants of emerging concerns, behave as pseudo-persistent despite their relatively short environmental half-lives in the environment. Therefore, residual levels of …


Applying Ahp And Clustering Approaches For Public Transportation Decisionmaking: A Case Study Of Isfahan City, Alireza Salavati, Hossein Haghshenas, Bahador Ghadirifaraz, Jamshid Laghaei, Ghodrat Eftekhari Dec 2016

Applying Ahp And Clustering Approaches For Public Transportation Decisionmaking: A Case Study Of Isfahan City, Alireza Salavati, Hossein Haghshenas, Bahador Ghadirifaraz, Jamshid Laghaei, Ghodrat Eftekhari

Journal of Public Transportation

The main purpose of this paper is to define appropriate criteria for the systematic approach to evaluate and prioritize multiple candidate corridors for public transport investment simultaneously to serve travel demand, regarding supply of current public transportation system and road network conditions of Isfahan, Iran. To optimize resource allocation, policymakers need to identify proper corridors to implement a public transportation system. In fact, the main question is to adopt the best public transportation system for each main corridor of Isfahan. In this regard, 137 questionnaires were completed by experts, directors, and policymakers of Isfahan to identify goals and objectives in …


Experimental Methods In Cryogenic Spectroscopy: Stark Effect Measurements In Substituted Myoglobin, Bradley Michael Moran Dec 2016

Experimental Methods In Cryogenic Spectroscopy: Stark Effect Measurements In Substituted Myoglobin, Bradley Michael Moran

Theses and Dissertations

Dawning from well-defined tertiary structure, the active regions of enzymatic proteins exist as specifically tailored electrostatic microenvironments capable of facilitating chemical interaction. The specific influence these charge distributions have on ligand binding dynamics, and their impact on specificity, reactivity, and biological functionality, have yet to be fully understood. A quantitative determination of these intrinsic fields would offer insight towards the mechanistic aspects of protein functionality. This work seeks to investigate the internal molecular electric fields that are present at the oxygen binding site of myoglobin.

Experiments are performed at 1 K on samples located within a glassy matrix, using the …


Report On The Condition Trend Of The Western Australian Pastoral Resource Base 2016, Andrew Watson, Philip Thomas Dec 2016

Report On The Condition Trend Of The Western Australian Pastoral Resource Base 2016, Andrew Watson, Philip Thomas

Natural resources published reports

Consistent with the Pastoral Lands Board’s (PLB) direction, data and analyses are reported at the Land Conservation District (LCD) scale. Some caution is urged when interpreting the report as this summary data may mask the variation in condition evident on leases within an LCD.

In the Kimberley, the analyses of the WARMS point data suggest that the trend in rangeland condition indicated by the frequency of desirable perennial grasses is stable. This is consistent with previous recent reports. However, the analyses of MODIS satellite plant cover data and greenness response indicated by NDVI, suggest areas of the Derby – West …


On The Propagation Of Atmospheric Gravity Waves In A Non-Uniform Wind Field: Introducing A Modified Acoustic-Gravity Wave Equation, Ahmad Talaei Dec 2016

On The Propagation Of Atmospheric Gravity Waves In A Non-Uniform Wind Field: Introducing A Modified Acoustic-Gravity Wave Equation, Ahmad Talaei

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

Atmospheric gravity waves play fundamental roles in a broad-range of dynamical processes extending throughout the Earth’s neutral atmosphere and ionosphere. In this paper, we present a modified form for the acoustic-gravity wave equation and its dispersion relationships for a compressible and non-stationary atmosphere in hydrostatic balance. Importantly, the solutions have been achieved without the use of the well-known Boussinesq approximation which have been used extensively in previous studies.

We utilize the complete set of governing equations for a compressible atmosphere with non-uniform airflows to determine an equation for vertical velocity of possible atmospheric waves. This intricate wave equation is simplified …


Inter-Relationships Linking Probability Of Becoming A Case Of Nicotine Dependence With Frequency Of Tobacco Cigarette Smoking, Olga A. Vsevolozhskaya, James C. Anthony Dec 2016

Inter-Relationships Linking Probability Of Becoming A Case Of Nicotine Dependence With Frequency Of Tobacco Cigarette Smoking, Olga A. Vsevolozhskaya, James C. Anthony

Biostatistics Faculty Publications

INTRODUCTION: Once smoking starts, some tobacco cigarette smokers (TCS) can make very rapid transitions into tobacco dependence syndromes (TCD). With adjustment for smoking frequency, we posit female excess risk for this rapid-onset TCD. In a novel application of functional analysis for tobacco research, we estimate four Hill function parameters and plot TCD risk against a gradient of smoking frequency, as observed quite soon after smoking onset.

METHODS: In aggregate, the National Surveys of Drug Use and Health, 2004-2013, identified 1546 newly incident TCS in cross-sectional research, each with standardized TCD assessment.

RESULTS: Hill function estimates contradict our apparently over-simplistic hypothesis. …


The Relationship Between Lead In Groundwater And Elementary School Students' Academic Performance In Missouri, Lynnette Xiangling Li Dec 2016

The Relationship Between Lead In Groundwater And Elementary School Students' Academic Performance In Missouri, Lynnette Xiangling Li

MSU Graduate Theses

Lead exposure can come from various sources, e.g., lead mines, industrial areas, and lead based paint. Missouri has more than 4,128 lead mines. Lead is a neurotoxin. The objectives of the study were to investigate i) the spatial relationship between lead mines and lead distribution in groundwater, ii) the statistical impact of lead in groundwater on students' Missouri Assessment Program (MAP) scores, and iii) the geographic variations of lead's impact on students' MAP scores. Geographic Information Science spatial analysis tools were used to analyze the concentration of lead in groundwater within school districts in Missouri. Regression analysis was utilized to …


Random Walks In A Sparse Random Environment, Anastasios Matzavinos, Alexander Roitershtein, Youngsoo Seol Dec 2016

Random Walks In A Sparse Random Environment, Anastasios Matzavinos, Alexander Roitershtein, Youngsoo Seol

Mathematics and Statistics Faculty Publications

We introduce random walks in a sparse random environment on ℤ and investigate basic asymptotic properties of this model, such as recurrence-transience, asymptotic speed, and limit theorems in both the transient and recurrent regimes. The new model combines features of several existing models of random motion in random media and admits a transparent physical interpretation. More specifically, a random walk in a sparse random environment can be characterized as a “locally strong” perturbation of a simple random walk by a random potential induced by “rare impurities,” which are randomly distributed over the integer lattice. Interestingly, in the critical (recurrent) regime, …


Infrasound Propagation In Terrestrial Planetary Atmospheres, Lynsey B. Schroeder Dec 2016

Infrasound Propagation In Terrestrial Planetary Atmospheres, Lynsey B. Schroeder

Doctoral Dissertations and Master's Theses

Acoustic waves in the infrasonic frequency range, that is below 10 Hertz, have been observed to propagate to high altitudes in Earth's atmosphere. These waves have many sources, both natural and artificial, such as seismic events, convective storm systems, and nuclear explosions. Here, we seek to better understand the characteristics of atmospheric infrasound- below 0.1 Hz in particular- so as to improve the ability to detect their presence and sources. It is well-known that ambient attributes of an atmosphere, such as temperature, density, and composition, directly affect the propagation and growth of waves, and therefore it is likely that these …