Physical Sciences and Mathematics Commons^™

Combining Atomic Force Microscopy And Shear-Force Acoustic Near-Field Microscopy To Characterize Confined Mesoscopic Fluids, Monte Allen Kozell, Theodore Brockman, Andres H. La Rosa

Physics Faculty Publications and Presentations

An atomic force microscopy (AFM) cantilever is integrated into to a quartz tuning fork (QTF) to probe the viscoelastic properties of mesoscopic fluid layers confined between two solid surfaces under shear. Two procedures to fabricate the AFM/QTF probe are described herein. In the first, a nano-manipulator is used to transport a commercially available afm cantilever from its chip holder to the edge of a QTF tine. In the second, an afm cantilever is fabricated at the edge of the QTF tine itself. In both cases we exploit the capabilities of a dual-beam system (focused ion beam/scanning electron microscope), equipped with …

Finite Element Method Analysis Of Whispering Gallery Acoustic Sensing, T. Le, H. Tran, Rodolfo Fernandez Rodriguez, C.J. Solano Salinas, Nima Laal, R. Bringas, J. Quispe, F. Segundo, Andres H. La Rosa

Physics Faculty Publications and Presentations

Whispering Gallery Acoustic Sensing (WGAS) has recently been introduced as a sensing feedback mechanism to control the probe-sample separation distance in scanning probe microscopy that uses a quartz tuning fork as a sensor (QTF-SPM). WGAS exploits the SPM supporting frame as a resonant acoustic cavity to monitor the nanometer-sized amplitude of the QTF oscillations. Optimal WGAS sensitivity depends on attaining an exact match between the cavity's frequency peak response and the TF resonance frequency. However, two aspects play against this objective: i) the unpredictable variability of the TF resonance frequency (upon attaching a SPM-probe to one of its tines), …

Instrumentation-Level Improvements In Shear-Force Near-Field Acoustic Microscopy, J. Bai, P. Devulapalli, Theodore Brockman, Andres H. La Rosa

Physics Faculty Publications and Presentations

The recently introduced Shear-force Near-field Acoustic Microscopy (SANM) brings a new sensing mechanism to the scanning probe microscopy family. SANM's ability to simultaneously monitor, in real time, several physical sample's responses presents some challenges for ensuring optimal operation; namely, avoid "cross-talk" among the multiple signals, address the compensation of thermal drift to ensure reproducibility of the measurements, and measuring the typical low-level signals obtained from nanometer-sized tested regions. Here, several improvements relevant to SANM, but valid for SPM in general, are addressed. i) The probe's coarse approach is performed via stepper motors, which are controlled either by a computer …

Probe Damage Evaluation In Frequency-Modulation Shear-Force Acoustic Near-Field Microscopy, Theodore Brockman, Rodolfo Fernandez Rodriguez, J. Bai, Monte Allen Kozell, Andres H. La Rosa

Physics Faculty Publications and Presentations

Shear-force acoustic near-field microscopy (SANM) and Whispering Gallery Acoustic Sensing have recently been introduced as a tandem system to characterize the viscoelastic response of fluids confined between two solid-boundaries in relative oscillatory lateral motion. SANM uses a) a laterally oscillating tapered probe (attached to a quartz tuning fork QTF) as one of the trapping boundaries, and b) an acoustic sensor (attached to the other flat-substrate boundary) that independently monitors the fluid’s acoustic emission. On the other and, WGAS is another technique that uses an acoustic transducer (attached to the frame holding the probe) to monitor the probe’s lateral motion amplitude. …

Phr: Patient Health Record, Quinn Nelson

Theses/Capstones/Creative Projects

The rapid development of information technology systems has expanded into multiple disciplines and results in systems that are limited by initial design and implementation: the Healthcare Information Technology (HIT) space is no different. The introduction of the Electronic Health Record (EHR) system has changed the way healthcare operates. Initial designs of these systems were focused on serving the needs of insurance companies and healthcare billing departments. Research shows that the design of EHR systems negatively impact provider-patient interactions and the care they receive. This capstone project capitalizes on the collaboration efforts between UNO and UNMC – by joining a research …

Subsurface Analysis Of Mississippian Tripolitic Chert In Northwest Arkansas, Thomas Jason Liner

Graduate Theses and Dissertations

Over the past 70 years the Mississippian strata of Northwest Arkansas have been studied in great detail. The study area is located on the escarpment between the Boston Mountains Plateau and the Springfield Plateau where a surface occurrence of Mississippian age rock allows for access to outcrops in close proximity to gas wells that encounter subsurface Mississippian strata. Many outcrops found in Northwest Arkansas expose Lower Mississippian (Kinderhookian-Osagean) strata that represent a full third order transgressive/regressive sequence that is unconformity bounded. These Mississippian outcrops are commonly treated as surface analogs to the Mississippi Lime Play in North Central Oklahoma. This …

Subsurface Stratigraphic Interpretation Of The Lower Atoka Formation, Northern Arkoma Basin, Arkansas, William Stephen Denham

Graduate Theses and Dissertations

The Arkoma Basin is a Carboniferous peripheral foreland basin creating a structural depression covering an approximate area of 33,800 miles2 that extends through east-central Oklahoma and west-central Arkansas. The entire basin fill includes Pre-Mississippian carbonate shelf deposits, Mississippian marine carbonates and black shales, and Pennsylvanian mixed carbonated/clastic and shore zone/deltaic deposits. The Lower Atoka formation (Pennsylvanian) occurs in outcrop along the southern Boston Mountain Plateau in northern Arkansas and extends into the subsurface of the Arkoma Basin over an area of 2,300 miles2. The Lower Atoka ranges from 600 to 1500 feet in thickness and represents a cyclic succession of …

Hartogs Domains And The Diederich-Fornæss Index, Muhenned Abdulameer Abdulsahib

Graduate Theses and Dissertations

The Diederich-Fornss Index has played a crucial role in studying regularity of the Bergman projection on pseudoconvex domains in Sobolov spaces as is shown by Kohn, Harrington, Pinton and Zampieri and others. In this work, we discuss the Diederich-Fornss Index on Hartogs domains, and its relation to other properties connected to regularity of the Bergman projection. An upper and lower bound for the Diederich-Fornss Index is calculated for Hartogs domains and computed sharply for worm domains. Related conditions for the existence of a strong Stein neighborhood basis for Hartogs domains are introduced.

Quantitative Microbial Risk Assessment For Parts, Ground, And Msc Poultry Product Including Intervention Analysis And Exploration Of Enterobacteriaceae As An Indicator Organism In Poultry Processing, Leigh Ann Parette

Graduate Theses and Dissertations

Samples collected at five different large bird poultry processing facilities over a period of 7 months from prescald to post debone locations were enumerated for Enterobacteriaceae, Salmonella spp., and Campylobacter spp. and the results were used to create Quantitative Microbial Risk Analyses (QMRA) models for parts, ground, and mechanically separated chicken (MSC) products. Sensitivity analyses indicated the points in the process at which reductions would be most advantageous to the endpoint and simulation models were run to test reductions required to meet the current USDA performance standards.

These data were analyzed to determine the reductions from one node (location) to …

Keeping Pace With Relative Sea Level Rise: Marsh Platform Monitoring Shows Minimal Sediment Deficit Along The Louisiana Coast, Kelly Marie Sanks

Graduate Theses and Dissertations

Recent reports estimate that the marshes of the Mississippi Delta receive just 30% of the sediment necessary to sustain current land area1. An extensive monitoring campaign by the USGS and LCPRA provides direct measurements of sediment accumulation, subsidence rates, and deposit characteristics along the coast over the past 10 years2, allowing us to directly evaluate this sediment balance. By interpolating bulk density, organic fraction, and vertical accretion rates from 273 sites, a direct measurement of organic and inorganic sediment accumulation can be made. Results show that a total of 82 MT/year of sediment is delivered to the coast. Using a …

An Adaptive Memory-Based Reinforcement Learning Controller, Keith August Cissell

Graduate Theses/Dissertations

Recently, the use of autonomous robots for exploration has drastically expanded--largely due to innovations in both hardware technology and the development of new artificial intelligence methods. The wide variety of robotic agents and operating environments has led to the creation of many unique control strategies that cater to each specific agent and their goal within an environment. Most control strategies are single purpose, meaning they are built from the ground up for each given operation. Here we present a single, reinforcement learning control solution for autonomous exploration intended to work across multiple agent types, goals, and environments. The solution presented …

Metal Contamination And Food Web Changes Alter Exposure To Upper Trophic Levels In Upper Blackfoot River Basin Streams, Montana, Jack E. Landers, Sean Sullivan, Lisa Eby, Andrew C. Wilcox, Heiko Langner

Geosciences Faculty Publications

Reduced invertebrate abundance and diversity are common responses to metals contamination in mining-impacted streams. The resulting changes in community composition may have implications for metals accumulation and transfer through the food web. We investigated how changes in invertebrate community composition (abundance, species richness, and food web complexity) influence metals bioaccumulation and exposure risk to upper trophic levels along a contamination gradient in the upper Blackfoot River Basin, Montana. Invertebrate species richness exhibited the strongest decline with increasing sediment metals concentrations, driven by the loss of metals-sensitive taxa. These changes in invertebrate community composition resulted in a decline in the proportion …

Relationships Between Social Network Characteristics, Alcohol Use, And Alcohol-Related Consequences In A Large Network Of First-Year College Students: How Do Peer Drinking Norms Fit In?, Graham T. Diguiseppi, Matthew K. Meisel, Sara G. Balestrieri, Miles Q. Ott, Melissa A. Clark, Nancy P. Barnett

Statistical and Data Sciences: Faculty Publications

A burgeoning area of research is using social network analysis to investigate college students' substance use behaviors. However, little research has incorporated students' perceived peer drinking norms into these analyses. The present study investigated the association between social network characteristics, alcohol use, and alcohol-related consequences among first-year college students (N 1,342; 81% of the first-year class) at one university. The moderating role of descriptive norms was also examined. Network characteristics and descriptive norms were derived from participants' nominations of up to 10 other students who were important to them; individual network characteristics included popularity (indegree), network expansiveness (outdegree), relationship reciprocity, …

Framing Climate Change As National Security: A Survey-Experiment On Climate Change Perceptions., Adam Lyons

Electronic Theses and Dissertations

The issues surrounding climate change continue to have polarizing effects on many Americans. In this thesis I offer a potential bridge to this divide with a comprehensive study on how issue frames can impact how individuals shape their opinions on environmental issues. Focusing on a national security frame, I ask the central research “Will the public perceive issues of climate change differently when they are framed as threats to national security?” For this thesis I design an original experimental survey to measure the impact security framing has on participants’ perception of both climate change and environmental policy options. The survey …

Spatial And Temporal Structure Of A Canid Community In Nebraska, Lucia Corral Hurtado

School of Natural Resources: Dissertations, Theses, and Student Research

Understanding patterns of space-use by individuals, their distribution, and how they coexist with ecologically similar species is crucial to address various issues in ecology, evolution, conservation biology, and wildlife management. However, the study of such patterns challenging because the relationship among species and their environment is shaped by multiple ecological processes, many of which are acting at different scales, often in a hierarchical manner. In the Canidae family, for instance, where interference competition appears critical, larger species such as coyotes (Canis latrans), can often affect smaller species, such as red fox (Vulpes vulpes) and swift fox …

Relationships Among Biodiversity Dimensions Of Birds In Nebraska, Nadejda Mirochnitchenko

School of Natural Resources: Dissertations, Theses, and Student Research

Biological diversity, or biodiversity, is a multi-dimensional concept that can be decomposed to measure information about taxonomic, phylogenetic, and functional variation within communities. Although the dimensions of biodiversity are interrelated, the assumption that measuring one dimension of diversity can inform about patterns in another dimension does not necessarily follow from theory or empirical study. The relationships among biodiversity dimensions is not well understood, nor how differences among dimensions could influence conservation decision making. Using the avian community as a study system, we explored the relationships of breadth metrics from the taxonomic, phylogenetic, and functional dimensions among each other and across …

Landscape Structure And Dynamics Of Recreational Fisheries, Christine N. Ruskamp

School of Natural Resources: Dissertations, Theses, and Student Research

Angler populations and the waterbodies they use are patchily distributed, creating putatively complex user-resource dynamics on the landscape. Spatially and temporally dynamic relationships between anglers and waterbodies can be difficult to track, understand, and manage. We often focus our efforts on the angler (directly or indirectly) with far less attention devoted to understanding the spatial structure and dynamics of fisheries on the landscape. Waterbodies serve as dynamic attractors on the landscape, shaping landscape patterns in angler participation. We surmise that by understanding the spatial structure and dynamics of recreational fisheries we can gain tremendous insight to cross-scale patterns that shape …

Managing For Vegetation Heterogeneity On Rangelands: An Exploration Of Rancher Attitudes, Stephanie Marie Kennedy

School of Natural Resources: Dissertations, Theses, and Student Research

Grasslands provide food, fiber, and numerous ecosystem services to human populations as well as habitat for wildlife. They are also some of the most endangered ecosystems in the world because of their productive soils and open topography. This problem is exacerbated by the accelerating conversion of grassland to cropland and encroaching trees and shrubs. The quality of remaining grasslands will be of increasing importance because of the biodiversity and vital ecosystem services they provide. Heterogeneity is a term specific to rangeland science that is illustrative of grassland health. Grassland species require very specific and differing habitats and without the variation …

The Biological Significance And Utility Of Feeding By Dermestes Maculatus, Braymond Adams

School of Natural Resources: Dissertations, Theses, and Student Research

With their efficient feeding habits and tolerance to very low moisture and humidity, beetles in the Family Dermestidae are especially adapted to variable environments and habitats. Dermestid cultures have been in use since 1922 in cleaning tissue and flesh from bones, and proven benefit in multiple fields, including zoology, ornithology, and forensics. Dermestid feeding behaviors when coupled with known life stage and insect succession information aids in providing significant entomological evidence. However, the feeding activities of insects, like those of vertebrate scavengers and predators, change remains and may leave artifacts that can be sometimes be difficult to assign to a …

Role Of Misclassification Estimates In Estimating Disease Prevalence And A Non-Linear Approach To Study Synchrony Using Heart Rate Variability In Chickens, Dola Pathak

Department of Statistics: Dissertations, Theses, and Student Research

Infectious disease assays can be imperfect. When estimating disease prevalence, these imperfections are accounted for by incorporating assay sensitivity and specificity into point and variance estimates. Unfortunately, these accuracy measures are often treated as fixed constants, rather than acknowledging that they are estimates from an assay validation process. The purpose of this study is to show the detrimental effect of not taking into account this sampling variability when samples are obtained through group testing (aka, pooled testing). We show that confidence interval coverage can dramatically decline as the sample size increases for the main sample of interest. As a remedy …

Synthesis, Characterization, And Catalytic Activity Of Copper Palladium Oxide Solid Solutions., Gregory L. Christensen

Department of Chemistry: Dissertations, Theses, and Student Research

Cu_xPd_1-xO forms a homogeneous solid solution over the wide range of 0 ≤ x ≤ 0.725 in which compositional variation can be correlated with structural and chemical environmental changes. After a small lag at low Cu²⁺ concentrations, where the lattice cell parameters are pinned to that of the pure PdO structure, Cu_xPd_1-xO lattice parameters follow Vegard’s law in which the cell volume decreases linearly with x, indicating a homogenous solution in which Cu²⁺ randomly replaces the larger Pd²⁺ cation. The crystal structure also undergoes an increase in the c/a …

Pedogenic Carbonates And Radiocarbon Isotopes Of Organic Carbon At Depth In The Russian Chernozem, Elena A. Mikhailova, Ray B. Bryant, John M. Galbraith, Yang Wang, Christopher J. Post, Olga S. Khokhlova, Mark A. Schlautman, Michael P. Cope, Zhixiong Shen

Marine Science

Conversion of native grasslands to agricultural sites has resulted in remarkable changes in soil carbon at depth, but its impact on soil diagnostic horizons is unknown. This study was conducted to radiocarbon date the soil organic carbon (SOC) and quantify pedogenic carbonates in the Russian Chernozem at depth at three sites: a native grassland field (not cultivated for at least 300 years), an adjacent 50-year continuous fallow field in the V.V. Alekhin Central-Chernozem Biosphere State Reserve in the Kursk region of Russia (UNESCO—MAB Biosphere Reserve), and a cropland in the Experimental Station of the Kursk Institute of Agronomy and Soil …

The Response Of Ionosphere And Thermosphere To The High Latitude Energy Deposition, Yang Lu

Physics Dissertations - Archive

The ionosphere and thermosphere are the important regions in the Earth upper atmosphere. They represent the ionized and neutral particles, respectively. The main external energy sources in those regions are solar radiation and geomagnetic energy due to the solar wind-magnetosphere interaction. The neutral particles are ionized by solar radiation on the dayside. Meanwhile, the energy deposition from the magnetosphere is also critical at high latitudes. The energy source at high latitudes depends on whether the local magnetic field line is closed or not. In the polar cap region where it is connected to open magnetic field line, the main energy …

Full Issue, The Mcnair Team

McNair Scholars Research Journal

No abstract provided.

About The Mcnair Scholars Program, The Mcnair Team

McNair Scholars Research Journal

No abstract provided.

Scholarships, The Mcnair Team

McNair Scholars Research Journal

No abstract provided.

Towards Automated Domain-Oriented Lexicon Construction And Dimension Reduction For Arabic Sentiment Analysis, Hasan A. Alshahrani

Dissertations

Sentiment analysis is a type of text mining that uses Natural Language Processing (NLP) tools to identify and label opinionated text. There are two main approaches of sentiment analysis: lexicon-based, and statistical approach. In our research, we use the lexicon-based approach because the lexicon contains sentiment words and phrases which are the main linguistic units to express sentiments. More specifically, we work with domain-oriented lexicons as they are more efficient than general ones because the polarity is heavily driven by domains.

Arabic language has a degree of uniqueness that makes it hard to be processed with the available cross-language tools …

Generalized Line Graphs, Mohra Abdullah Z. Alqahtani

Dissertations

With every nonempty graph, there are associated many graphs. One of the best known and most studied of these is the line graph L (G) of a graph G, whose vertices are the edges of G and where two vertices of L (G) are adjacent if the corresponding edges of G are adjacent. This concept was implicitly introduced by Whitney in 1932. Over the years, characterizations of graphs that are line graphs have been given, as well as graphs whose line graphs have some specified property. For example, Beineke characterized graphs that are line graphs by forbidding certain graphs …

Protecting Privacy Of Data In The Internet Of Things With Policy Enforcement Fog Module, Abduljaleel Al-Hasnawi

Dissertations

The growth of IoT applications has resulted in generating massive volumes of data about people and their surroundings. Significant portions of these data are sensitive since they reflect peoples' behaviors, interests, lifestyles, etc. Protecting sensitive IoT data from privacy violations is a challenge since these data need to be handled by public networks, servers and clouds, most of which are untrusted parties for data owners. In this study, a solution called Policy Enforcement Fog Module (PEFM) is proposed for protecting sensitive IoT data. The primary task of the PEFM solution is mandatory enforcement of privacy polices for sensitive IoT data-whenever …

Assessing Land Deformation And Sea Encroachment In The Nile Delta: A Radar Interferometric And Modeling Approach, Esayas Gebrekidan Gebremichael

Dissertations

Many of the deltas of the world are experiencing land deformation, subsidence or uplift of landmass, due to natural or anthropogenic causes, or a combination of both processes and causes. These deltaic settings are densely populated and border some of our world’s largest water bodies (oceans and seas). The land deformation, especially the subsidence component, when combined with the climate change-induced sea level rise, coastal erosion, and other anthropogenic drivers, will undoubtedly impact the population and economy of coastal areas of deltas. For the Nile Delta of Egypt, the land deformation processes and the factors that control the deformation processes …