Physical Sciences and Mathematics Commons^™

Characterization Of The Constituent Mineral Components Of North African Surface Dust Samples Utilizing Computer Controlled Scanning Electron Microscopy (Ccsem), Zakariah Edward Sabatka

Earth & Environmental Sciences Theses - Archive

Analysis of the constituent mineral components of surface dusts/soils from Chad-Niger region, North Africa, was undertaken by computer controlled scanning electron microscopy (CCSEM) to determine if differences in composition could be used for source attribution to distinguish windblown material from different contributing source areas. A total of 11 surficial samples were selected for analysis by computer controlled scanning electron microscopy (CCSEM). These samples were from two different geographic locations in the Chad-Niger region. CCSEM analysis generates data on individual dust particles that includes: particle size, shape, and chemical composition. This type of particle characterization used a Scanning Electron Microscope (SEM) …

Nebraska's Public Access Hunting Program: Hunter Preferences And Usage Final Report, Lisa Pennisi, Mark E. Burbach, Namyun Kil, Muhammed Imran Kahn, Andrew J. Tyre

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Real Time Analytics On Digital Distraction, Kristian Welch

Computer Science and Software Engineering

Hypothesis: empirically measuring the users productivity has the potential to significantly increase their productivity. This paper is the documentation of the process of building software capable of verifying this hypothesis. Starting with the research which gives enough evidence to warrant the hypothesis, also included is commentary on the prototyping, design decisions, and iteration based on user feedback of the software.

Gas Dynamics In Tidal Dwarf Galaxies: Disc Formation At Z = 0, Federico Lelli, Stacy Mcgaugh

Faculty Scholarship

Tidal dwarf galaxies (TDGs) are recycled objects that form within the collisional debris of interacting and merging galaxies. They are expected to be devoid of non-baryonic dark matter, since they can only form from dissipative material ejected from the discs of the progenitor galaxies. We investigate the gas dynamics in a sample of six bona fide TDGs around three interacting and post-interacting systems: NGC 4694, NGC 5291, and NGC 7252 ("Atoms for Peace"). For NGC 4694 and NGC 5291, we analyse existing HI data from the Very Large Array (VLA),while for NGC 7252 we present new HI observations from the …

Deposition And Characterization Of Carbon Nanotubes (Cnts) Based Films For Sensing Applications, Amila C. Dissanayake

Dissertations

The advent of carbon nanotubes (CNTs) has opened up lot of novel applications because of their unique electrical and mechanical properties. CNTs are well known material for its exceptional electrical, mechanical, optical, thermal and chemical properties. A single-wall nanotube (SWNT) can be either semiconducting, metallic or semi-metallic, based on its chirality and diameter. SWNTs can be used in transistor device as active channels due to high electron mobility (~10000 cm2/(V s), electrical interconnects, nano-scale circuits, field-emission displays, light-emitting devices and thermal heat sinks due to low resistivity, high current density (~109A cm-2) and high thermal conductivity (~3500 W m-1). Further, …

Deep Fluid Inputs Into The Continental-Scale Nubian Sandstone Aquifer System Constrained By Hydrochemical, Stable Isotope, And Noble Gas Data, Abdel Mawgoud Mohammed

Dissertations

The Nubian Sandstone Aquifer System (NSAS) of northeastern Africa is one of the largest confined fossil-water aquifer systems in the world, with several nations relying on it (Egypt, Libya, Sudan and Chad). This groundwater is the biggest and in some cases the only future source of water to meet the development goals of each NSAS country. This study provides new geochemical data from the main oases of the Western Desert of Egypt and a compilation of published hydrochemical data from the regional aquifer. Interpretation of results suggests heterogeneous fluid mixing within the aquifer, the potential for hydrochemical sub-basins, and a …

Co-Rotational Finite Element Solid Simulation With Collisions, Patrick Riordan

Computer Science and Software Engineering

This paper is a tutorial on how to implement a deformable solid simulation with collisions based off of Matthias Mueller's Real Time Physics Course Notes. It covers the topics continuum mechanics, finite element analysis, implicit Euler integration, and handling collision.

Spatial Analysis Of Distributions And Habitat Conditions Of Fallopia Japonica (Japanese Knotweed) Invasive Species Applying Unmanned Helicopter Remote Sensing, Jiazhen Zhang

Great Lakes Center Masters Theses

Abstract:

Fallopia japonica (Japanese knotweed) is a perennial herbaceous plant that is native to East Asia. It is considered as one of the worst invasive species worldwide because of its serious impact on biological diversity and human activities (Lowe et al., 2001). Once established, Japanese knotweed forms dense stands that shade and crowd out native plant species. The objectives of this research were to verify and confirm the distribution of Japanese knotweed as published online by the New York Department of Environmental Conservation (DEC) – iMap and to identify the geographic areas of spreading and the local habitat conditions. In …

Mycorrhizal Roots In A Temperate Forest Take Up Organic Nitrogen From 13c- And 15n-Labeled Organic Matter, Matthew A. Vadeboncoeur, Andrew P. Ouimette, Erik A. Hobbie

All Materials

Background and Aims

The importance of the uptake of nitrogen in organic form by plants and mycorrhizal fungi has been demonstrated in various ecosystems including temperate forests. However, in previous experiments, isotopically labeled amino acids were often added to soils in concentrations that may be higher than those normally available to roots and mycorrhizal hyphae in situ, and these high concentrations could contribute to exaggerated uptake.

Methods

We used an experimental approach in which we added ¹³C-labeled and ¹⁵N-labeled whole cells to root-ingrowth cores, allowing proteolytic enzymes to release labeled organic nitrogen at a natural rate, as …

Semi-Automated Object-Based Classification Of Coral Reef Habitat Using Discrete Choice Models, Steven Saul, Samuel J. Purkis

Marine & Environmental Sciences Faculty Articles

As for terrestrial remote sensing, pixel-based classifiers have traditionally been used to map coral reef habitats. For pixel-based classifiers, habitat assignment is based on the spectral or textural properties of each individual pixel in the scene. More recently, however, object-based classifications, those based on information from a set of contiguous pixels with similar properties, have found favor with the reef mapping community and are starting to be extensively deployed. Object-based classifiers have an advantage over pixel-based in that they are less compromised by the inevitable inhomogeneity in per-pixel spectral response caused, primarily, by variations in water depth. One aspect of …

Combating Anti-Statistical Thinking Using Simulation-Based Methods Throughout The Undergraduate Curriculum, Nathan L. Tintle, Beth Chance, George Cobb, Soma Roy, Todd Swanson, Jill Vanderstoep

Faculty Work Comprehensive List

The use of simulation-based methods for introducing inference is growing in popularity for the Stat 101 course, due in part to increasing evidence of the methods ability to improve students’ statistical thinking. This impact comes from simulation-based methods (a) clearly presenting the overarching logic of inference, (b) strengthening ties between statistics and probability/mathematical concepts, (c) encouraging a focus on the entire research process, (d) facilitating student thinking about advanced statistical concepts, (e) allowing more time to explore, do, and talk about real research and messy data, and (f) acting as a firmer foundation on which to build statistical intuition. Thus, …

Studies Of Influence Of Energy Distribution On The Upper Atmosphere, Cheng Sheng

Physics Theses - Archive

The energy inputs into the upper atmosphere including both solar irradiation and geomagnetic energy can significantly change the upper atmosphere such as the neutral and plasma densities, velocities and temperatures. Therefore, the precise specification of the energy inputs is critical to estimate the ionosphere/thermosphere variation during both quiet and storm times. In order to improve the understanding of the energy distribution and its influence at high latitudes, specifically, we have conducted the following studies. (1) Estimation of the altitudinal distribution of Joule heating from COSMIC observations. Joule heating is the most significant way to dissipate geomagnetic energy at high latitudes. …

Controlled Hydrosilylations Of Carbonyl Compounds And Computational Investigations Of A Hydride Shuttle Mechanism For Alkene Hydrosilylation, Gabriela Trog

Chemistry & Biochemistry Theses - Archive

Chapter 1 describes tandem dual hydrosilylations of α,β-unsaturated enals. Hydrosilylations of both carbonyl compounds and alkenes have been utilized to create chiral alcohols. Tandem dual hydrosilylations (TDH) of α,β-unsaturated carbonyl compounds create five-membered oxasilacycles that can be further converted to 1,3- diols, which are a common structural motif in the polyketide natural product family. We present preliminary data and a substrate scope for the formation of these oxasilacycles en route to the 1,3-diol compounds. Chapter 2 describes hydrosilylations of esters that result in silyl acetals. The silyl acetals are chemical synthons of the corresponding aldehyde. This reaction can be coupled …

Evaluation Of Activated Carbon As A Commercial Drug Disposal Product Using Liquid Chromatography–Tandem Mass Spectrometry, Veronica B. Waybright

Chemistry & Biochemistry Theses - Archive

At present, pharmaceuticals, synthetic organic compounds, and endocrine disrupting compounds are ubiquitous in our environment. These have been introduced by consumers and manufacturers directly and indirectly for decades. There is plenty of published literature addressing the presence of these compounds, the development of newer and more sensitive techniques to detect them at low concentrations, as well as studies showing their effects in the environment and in human health. However, these studies are based on the measurement and detection of these compounds after the fact; and even though some have addressed the need to decrease these pollutants in the environment, procedures …

New Conductometric Detection Methods For Sensitive Ion Chromatographic Measurement Of Weak Electrolytes, Hongzhu Liao

Chemistry & Biochemistry Theses - Archive

Since Suppressed conductometric anion chromatography (SCAC) was proposed in the mid-1970s, SCAC has become a widely used tool for the determination of anion species in aqueous samples. Its application ranges from trace analysis in semiconductor manufacture to pharmaceutical analysis. This dissertation primarily focuses on three different projects on the conductometric determination of weak acids. Other work carried out during the same period both involved SCAC for the determination of anion composition of açaí Extracts and on the unusual ion exchange behavior of myo‐inositol phosphates. SCAC responds poorly and nonlinearly to weak acids, because they only ionize partially and the degree …

Determination Of Total And D-Amino Acid Content In Mice Brain Tissue By Achiral-Chiral Heart-Cutting Two-Dimensional Liquid Chromatography: Diagnostic And Clinical Relevance And A Comparison Between Non-Perfused And Perfused Tissue, Curran Parpia

Chemistry & Biochemistry Theses - Archive

A heart-cutting two dimensional liquid chromatographic method for the quantification of free amino acid enantiomers from mouse brain tissue is demonstrated. Evidence to support the occurrence of D-amino acids in significant concentrations in physiological samples has spurred studies toward the elucidation of their importance and function. In this work, the level and regional distribution of select amino acids were determined by achiral-chiral LC/LC. Additionally, the effect of tissue perfusion on these levels was investigated. The free amino acid extracts were analyzed as their 9-fluorenylmethyloxycarbonyl derivatives and separated in the reverse phase mode on superficially porous C18. In the second dimension, …

No Major Changes On Paleoclimate And Paleoenvironment Across The Eocene–Oligocene Transition In The Central Rocky Mountains, Sara Ayyash

Earth & Environmental Sciences Theses - Archive

Earth’s climate has experienced dramatic cooling during the Eocene-Oligocene Transition (EOT) based on well-constrained marine geological records, however, a consensus on the terrestrial responses to this event has not been reached. The White River Formation in the central Rocky Mountains, western U.S.A., is a well-dated stratigraphic unit covering the EOT. The formation contains tuffaceous mudrock and sandstone that were deposited in fluvial and eolian depositional environments. Here I study oxygen isotope ratios and clumped isotope temperatures of carbonate cements and bulk organic carbon isotope ratios in order to reconstruct the paleoenvironment and paleoclimate across the EOT. These carbonate cements were …

Migmatite Gneiss Of The Jættedal Complex, Liverpool Land, East Greenland: Protracted High-T Metamorphism In The Overriding Plate Of The Caledonian Orogen, S. M. Johnston, A. Kylander-Clark, H. K. Brueckner

Physics

The Greenland Caledonides (GC) formed in the overriding Laurentian plate during the closure of the Iapetus Ocean and the subduction of Baltica, and offer a unique opportunity to study metamorphic patterns, regional structures and the kinematic evolution of the overriding plate of a continental collision. We present new metamorphic petrology and coupled zircon geochronology and geochemistry data from the Jættedal complex in southern Liverpool Land to document the thermal evolution of the orogenic core of the southern GC. Pelitic migmatite gneisses from the Jættedal complex document metamorphic conditions of 850–730 °C at pressures of 11–9.5 kbar. Zircon from these samples …

Differentialgeometry In Brno, Ian M. Anderson

Presentations

This page will provide files supporting Ian Anderson's presentations in Brno, December 2015. The files can be found and downloaded from "Additional Files", below.

The files include:

(1) DifferentialGeometryUSU.mla: This is the Maple Library Archive file which provides all the DifferentialGeometry functionality. Here are Installation Instructions.

(2) DifferentialGeometry.help : this is the latest version of the DifferentialGeometry documentation. Copy this file to the same directory used for DifferentialGeometryUSU.mla (from step (1)).

The Unique Electrochemical Reactivity Of Small Metal Nanoparticles., Rafael A. Masitas

Electronic Theses and Dissertations

This dissertation describes the factors controlling metal nanoparticle (NP) oxidation, using Au oxidation in Br- and Ag oxidation in acid as model systems. We found that the oxidation potential depends on size, surface charge, and electrode material. Size has a dramatic effect, shifting about 200 mV from > 200 nm diameter down to 4 nm diameter. The shift is more dramatic below 4 nm. 2.3 nm average diameter Au NPs oxidized in the 300-500 mV range and 1.5 nm average diameter Au NPs displayed several sharp peaks from 200 mV to as low as -200 mV. These smallest Au NPs show …

Multiple Instance Fuzzy Inference., Amine Ben Khalifa

Electronic Theses and Dissertations

A novel fuzzy learning framework that employs fuzzy inference to solve the problem of multiple instance learning (MIL) is presented. The framework introduces a new class of fuzzy inference systems called Multiple Instance Fuzzy Inference Systems (MI-FIS). Fuzzy inference is a powerful modeling framework that can handle computing with knowledge uncertainty and measurement imprecision effectively. Fuzzy Inference performs a non-linear mapping from an input space to an output space by deriving conclusions from a set of fuzzy if-then rules and known facts. Rules can be identified from expert knowledge, or learned from data. In multiple instance problems, the training data …

The Volta Grande Do Xingu: Reconstruction Of Past Environments And Forecasting Of Future Scenarios Of A Unique Amazonian Fluvial Landscape, A. O. Sawakuchi, G. A. Hartmann, H. O. Sawakuchi, F. N. Pupim, D. J. Bertassoli, M. Parra, J. L. Antinao, L. M. Sousa, M. H. Sabaj Pérez, P. E. Oliveira, R. A. Santos, J. F. Savian, C. H. Grohmann, V. B. Medeiros, Michael M. Mcglue, D. C. Bicudo, S. B. Faustino

Earth and Environmental Sciences Faculty Publications

The Xingu River is a large clearwater river in eastern Amazonia and its downstream sector, known as the Volta Grande do Xingu (“Xingu Great Bend”), is a unique fluvial landscape that plays an important role in the biodiversity, biogeochemistry and prehistoric and historic peopling of Amazonia. The sedimentary dynamics of the Xingu River in the Volta Grande and its downstream sector will be shifted in the next few years due to the construction of dams associated with the Belo Monte hydropower project. Impacts on river biodiversity and carbon cycling are anticipated, especially due to likely changes in sedimentation and riverbed …

Understanding The Impact Of Intensive Horticulture Land-Use Practices On Surface Water Quality In Central Kenya, Faith K. Muriithi, Danlin Yu

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Rapid expansion of commercial horticulture production and related activities contribute to declining surface water quality. The study sought to understand the impacts on select rivers in Laikipia and Meru, production hotspots. The specific aims were (1) to identify prevailing surface water quality by examining variations of 14 physico-chemical parameters, and (2) to categorize measured surface water quality parameters into land use types highlighting potential pollutant source processes. Water samples were collected in July and August 2013 along 14 rivers in the study area. The data were analyzed using principal component analysis (PCA) and discriminant analysis (DA). Principal components (PCs) explained …

Full Issue, The Mcnair Team

McNair Scholars Research Journal

No abstract provided.

Alumni Earning Doctorates, The Mcnair Team

McNair Scholars Research Journal

No abstract provided.

Scholarships Awarded To Mcnair Scholars, The Mcnair Team

McNair Scholars Research Journal

No abstract provided.

Development Of A Miniaturized Ambient Glow Discharge Ionization Source And Its Application In Elemental And Molecular Analysis, Xinyan Zhang

All Dissertations

Since the liquid sampling-atmospheric pressure glow discharge (LS-APGD) was first developed as an excitation source for atomic emission spectroscopy, it has been improved upon and demonstrated as an ionization source for elemental mass spectrometry, molecular mass spectrometry, and ambient desorption mass spectrometry. Multiple functions coming from one package allowed the LS-APGD to hold a unique position among all atmospheric pressure glow discharges. It also has the capabilities to work with different sample forms including liquids, bulk solids, and solution residues. The high salt/matrix tolerance reduces sample prep work and thus provides convenience for its potential use as a field-Based ionization …

Book Reviews: Bumble Bees Of North America. Paul H. Williams, Robbin W. Thorp, Leif L. Richardson, And Sheila R. Colla., Samuel O’Dell

The Prairie Naturalist

Bumblebee identification is generally considered straight- forward, yet mistakes often are made due to the degree of similarity between the color patterns of different species. Bumble Bees of North America aims to improve the accuracy of identifications by both casual observers and professionals through the use of intuitive diagrams, descriptions, and the more technical dichotomous keys. In addition to providing the first complete field guide to North American bumblebees, the authors make efficient use of the reader’s attention by summarizing taxonomic history, favored food plants, and environmental issues concerning bumblebees.

Bumble Bees of North America is organized into three distinct …

Effects Of Short-Term Soil Conditioning By Cheatgrass And Western Wheatgrass, James J. O'Connor, Janet S. Prevey

The Prairie Naturalist

The exotic grass Bromus tectorum (cheatgrass) is a ubiquitous invader in the western USA. Cheatgrass is a proficient competitor, frequently displacing native plants, forming monotypic stands and reducing biodiversity in ecosystems it invades. Our experiment tested whether short-term soil modification by cheatgrass and a predominant native grass, Pascopyrum smithii (western wheatgrass), affected subsequent growth of both species. We compared productivity of cheatgrass and western wheatgrass by harvesting aboveground biomass of plants grown in either cheatgrass- or western wheatgrass-conditioned soils over two simulated growing seasons. Results indicated that cheatgrass soils do not inhibit the productivity of the native grass, but do …

North Shore: A Natural History Of Minnesota’S Superior Coast, Janet R. Koeugh

The Prairie Naturalist

Many readers of The Prairie Naturalist have lived along or visited Lake Superior’s coast. Like me, you have probably wondered about the geology and history of this beautiful and dramatic feature of northeastern Minnesota. Chel Anderson and Adelheid Fischer have written an accessible book that comprehensively describes the history and geology of the coast, surrounding highlands, and Lake Superior itself. In addition, the authors have provided fascinating subchapters on some of the most interesting species that are key elements of the region.

This rather large but beautiful book is arranged in five major chapters that cover the dominant geological units …