Physical Sciences and Mathematics Commons^™

Magnetoelectric Coupling At The Euo/Batio3 Interface, Shi Cao, P Liu, Jinke Tang, Haidong Lu, C W. Bark, Sangjin Ryu, Chang-Beom Eom, Alexei Gruverman, Peter A. Dowben

Peter Dowben Publications

Magnetization modulation by ferroelectric polarization switching is reported for the ferromagnetic-ferroelectric EuO/BaTiO₃heterostructure. The value of the magnetization critical exponent β is consistent with the expected Heisenberg-like ferromagnetism of EuO and reported Curie temperature. The critical exponent is seen to decrease with increased magnetic coupling. The results are discussed in the context of data obtained earlier for epitaxial La_0.67Sr_0.33MnO₃/BaTiO₃ heterostructures, where magnetization increases and critical exponent b also declines with ferroelectric polarization pointing away from ferromagnetic layer. The observed similarity between two systems illustrates an importance of charge doping in magnetoelectric coupling, …

Reversible Mn Segregation At The Polar Surface Of Lithium Tetraborate, Christina Dugan, Robert L. Hengehold, Steve R. Mchale, Juan A. Colon Santana, John W. Mcclory, V T. Adamiv, Ya V. Burak, Yaroslav B. Losovyj, Peter A. Dowben

Peter Dowben Publications

We find Mn surface segregation for single crystals of Mn doped Li₂B₄O₇, nominally Li_1.95Mn_0.05 B₄O₇(001), but as the temperature increases, evidence of this Mn surface segregation diminishes significantly. At room temperature, the surface photovoltaic charging is significant for this pyroelectric material but is quenched at a temperature well below that seen for the undoped Li₂B₄O₇ samples. The suppression of surface charging in the region of 120°C that accompanies the temperature of Mn dissolution in the bulk of Li₂B₄O …

Grand Challenges In Condensed Matter Physics: From Knowledge To Innovation, Evgeny Y. Tsymbal, Peter A. Dowben

Peter Dowben Publications

Condensed Matter Physics (CMP) explores the fundamental properties of matter and their origins resulting from the interactions of a large number of atoms and electrons. The intricate nature of these interactions results in properties and associated phenomena that often hint at a rich vein of underlying physics. Although the perspective is changing constantly with new discoveries, the basic challenges in CMP are to predict and observe new phenomena and elucidate novel properties of materials often pushing at the frontiers of quantum mechanics [1].

CMP is also a field which stimulates technological innovation that revolutionizes modern society. For more than five …

Gamma And X-Ray Sensitivity Of Gd2O3 Heterojunctions, Juan A. Colon Santana, C M. Young, J W. Mcclory, J C. Petrosky, X Wang, P Liu, Jinke Tang, V T. Adamiv, Ya V. Burak, Keisuke Fukutani, Peter A. Dowben

Peter Dowben Publications

We find that Gd₂O₃ thin films strongly favor a (-402) texture growth on a variety of substrates and will form heterojunction diodes with silicon, especially when doped with oxygen vacancies. Even in the thin film limit, these heterojunction diodes appear to be sensitive to gamma radiation, likely from the X-rays created by scattering events, adding to the numerous hurdles that must be overcome if Gd based semiconductor devices are to be used for solid state neutron detection applications.

Melt Generation Beneath Arctic Ridges: Implications From Ule, Lynne J. Elkins, K. W. Sims, J. Prytulak, J. Blichert-Toft, T. Elliott, J. Blusztajn, S. Fretzdorff,, M. Reagan, K. Haase, S. Humphris, J.-G. Schilling

Geology Faculty Research and Scholarship

We present new ²³⁸U-²³⁰Th-²²⁶Ra-²¹⁰Pb, ²³⁵U-²³¹Pa, and Nd, Sr, Hf, and Pb isotope data for the slow- to ultraslow-spreading Mohns, Knipovich, and Gakkel Ridges. Combined with previous work, our data from the Arctic Ridges cover the full range of axial depths from the deep northernmost Gakkel Ridge shallowing upwards to the Knipovich, Mohns, and Kolbeinsey Ridges north of Iceland. Age-constrained samples from the Mohns and Knipovich Ridges have (²³⁰Th/²³⁸U) activity ratios ranging from 1.165 to 1.30 and 1.101 to 1.225, respectively. The high ²³⁰Th excesses of …

New Microarray Image Segmentation Using Segmentation Based Contours Method, Yuan Cheng

Doctoral Dissertations

The goal of the research developed in this dissertation is to develop a more accurate segmentation method for Affymetrix microarray images. The Affymetrix microarray biotechnologies have become increasingly important in the biomedical research field. Affymetrix microarray images are widely used in disease diagnostics and disease control. They are capable of monitoring the expression levels of thousands of genes simultaneously. Hence, scientists can get a deep understanding on genomic regulation, interaction and expression by using such tools.

We also introduce a novel Affymetrix microarray image simulation model and how the Affymetrix microarray image is simulated by using this model. This simulation …

Nonlinear Granger Causality And Its Application In Decoding Of Human Reaching Intentions, Mengting Liu

Doctoral Dissertations

Multi-electrode recording is a key technology that allows the brain mechanisms of decision making, cognition, and their breakdown in diseases to be studied from a network perspective. As the hypotheses concerning the role of neural interactions in cognitive paradigms become increasingly more elaborate, the ability to evaluate the direction of neural interactions in neural networks holds the key to distinguishing their functional significance.

Granger Causality (GC) is used to detect the directional influence of signals between multiple locations. To extract the nonlinear directional flow, GC was completed through a nonlinear predictive approach using radial basis functions (RBF). Furthermore, to obtain …

An Approach To Discrete Quantum Gravity, S. Gudder

Mathematics Preprint Series

This article presents a simplified version of the author’s previous work. We first construct a causal growth process (CGP). We then form path Hilbert spaces using paths of varying lengths in the CGP. A sequence of positive operators on these Hilbert spaces that satisfy certain normalization and consistency conditions is called a quantum sequential growth process (QSGP). The operators of a QSGP are employed to define natural decoherence functionals and quantum measures. These quantum measures are extended to a single quantum measure defined on a suitable collection of subsets of a space of all paths. Continuing our general formalism, we …

Sellers Continue To Give Away Confidential Information On Second Hand Memory Cards Sold In Australia, Patryk Szewczyk, Nikki Robins, Krishnun Sansurooah

Australian Digital Forensics Conference

Second hand storage devices can be treasure troves of confidential data. This study investigated the remnant data on second hand memory cards that were purchased through Australian second hand auction websites throughout 2013. Memory cards continue to increase in capacity and are used in both smart phones and tablet computers as persistent storage. During this study a total of 140 second hand memory cards were purchased throughout 2013. Each memory card had its data recovered and subsequently analysed. The results show that sellers are sending memory cards with no evidence of erasure; poor attempts to erase data; or simply asking …

Extender Sets And Multidimensional Subshifts, Nic Ormes, Ronnie Pavlov

Mathematics Preprint Series

In this paper, we consider a Z d extension of the well-known fact that subshifts with only finitely many follower sets are sofic. As in [4], we adopt a natural Z d analogue of a follower set called an extender set. The extender set of a finite word w in a Z d subshift X is the set of all configurations of symbols on the rest of Z d which form a point of X when concatenated with w. As our main result, we show that for any d ≥ 1 and any Z d subshift X, if there exists …

A Dynamics For Discrete Quantum Gravity, Stan Gudder

Mathematics Preprint Series

This paper is based on the causal set approach to discrete quantum gravity. We first describe a classical sequential growth process (CSGP) in which the universe grows one element at a time in discrete steps. At each step the process has the form of a causal set (causet) and the “completed” universe is given by a path through a discretely growing chain of causets. We then quantize the CSGP by forming a Hilbert space H on the set of paths. The quantum dynamics is governed by a sequence of positive operators ρn on H that satisfy normalization and consistency conditions. …

Mass Transfer From A Vertical Flat Plate Due To Natural Convection With A Constant Counterflow, David Mcdonnell, Brendan Redmond, Lawrence J. Crane

Articles

This paper first examines the mass transfer from a vertical flat surface of a soluble material due to natural convection. A perturbation term is then introduced into the stream function to model the introduction of a constant counterflow. The effect this counterflow has on both the overall mass transfer and the overall velocity profile is studied in detail.

An Examination Of The Acceptance, Adoption, And Diffusion Of Smartphone Devices With Senior Citizens., James M. Reneau

CCE Theses and Dissertations

This research looked at the process of the diffusion of an innovation in the context of smartphones with American senior citizens. The subject of diffusion, or spread of a technology, is a rich and varied topic with more than 60 years of research. Much of this diffusion research does not go beyond the study of the original acceptance of a new idea. An on-line and face-to-face questionnaire was used to collect data from 155 seniors on the entire process of diffusion. The questionnaire was adaptive in nature, focusing questions directly at participants based on where they were in the diffusion …

Comparison Of Molecular Breeding Values Based On Within- And Across-Breed Training In Beef Cattle, Stephen D. Kachman, Matthew L. Spangler, Gary L. Bennett, Kathryn J. Hanford, Larry A. Kuehn, Warren M. Snelling, Mark Thallman, Mahdi Saatchi, Dorian J. Garrick, Robert D. Schnabel, Jeremy F. Taylor, E John Pollak

Department of Statistics: Faculty Publications

Background: Although the efficacy of genomic predictors based on within-breed training looks promising, it is necessary to develop and evaluate across-breed predictors for the technology to be fully applied in the beef industry. The efficacies of genomic predictors trained in one breed and utilized to predict genetic merit in differing breeds based on simulation studies have been reported, as have the efficacies of predictors trained using data from multiple breeds to predict the genetic merit of purebreds. However, comparable studies using beef cattle field data have not been reported.

Methods: Molecular breeding values for weaning and yearling weight …

Evaluating Acropora Cervicornis Growth And Survivorship In A Line Nursery, Zachary Ostroff

HCNSO Student Theses and Dissertations

Acropora cervicornis and A. palmata were once dominant, reef-building corals of Caribbean reefs. Over the last several decades, population declines of Caribbean Acropora have been dramatic, and both species are now listed as “Threatened” under the United States Endangered Species Act. Numerous restoration efforts now utilize coral gardening techniques to cultivate these species for transplantation, in which A. cervicornis is primarily cultivated both on fixed structures and in line nurseries. This study evaluates growth and survivorship of multiple A. cervicornis genotypes grown via two line nursery techniques, and compares the efficacy of each against the conventional method of fixed nursery …

Conservation Mooring Study, Urban Harbors Institute, University Of Massachusetts Boston

Urban Harbors Institute Publications

Most boaters who moor their vessels in Massachusetts waters have traditionally employed free swinging moorings that use heavy bottom chain. In important sensitive habitats such as eelgrass beds, these types of moorings often have negative impacts on the benthic habitat – from the circular movement of the chain around the anchor point, and/or from the anchor itself.

This document objectively describes the different characteristics of conventional moorings versus conservation moorings designed to minimize disruption to the benthic habitat. This report includes discussions on the following topics:

• Technologies available
• Ecological impacts
• Functional differences
• Economical differences
• Regulatory issues

These comparisons, along with …

On The Difference In Quality Between Current Heuristic And Optimal Solutions To The Protein Structure Alignment Problem, Mauricio Arriagada, Aleksandar Poleksic

Faculty Publications

The importance of pairwise protein structural comparison in biomedical research is fueling the search for algorithms capable of finding more accurate structural match of two input proteins in a timely manner. In recent years, we have witnessed rapid advances in the development of methods for approximate and optimal solutions to the protein structure matching problem. Albeit slow, these methods can be extremely useful in assessing the accuracy of more efficient, heuristic algorithms. We utilize a recently developed approximation algorithm for protein structure matching to demonstrate that a deep search of the protein superposition space leads to increased alignment accuracy with …

A Global Standard For Monitoring Coastal Wetland Vulnerability To Accelerated Sea-Level Rise, Edward L. Webb, Daniel A. Friess, Ken W. Krauss, Donald R. Cahoon, Glenn R. Guntenspergen, Jacob Phelps

United States Geological Survey: Staff Publications

Sea-level rise threatens coastal salt-marshes and mangrove forests around the world, and a key determinant of coastal wetland vulnerability is whether its surface elevation can keep pace with rising sea level. Globally, a large data gap exists because wetland surface and shallow subsurface processes remain unaccounted for by traditional vulnerability assessments using tide gauges. Moreover, those processes vary substantially across wetlands, so modelling platforms require relevant local data. The low-cost, simple, high-precision rod surface-elevation table–marker horizon (RSET-MH) method fills this critical data gap, can be paired with spatial data sets and modelling and is financially and technically accessible to every …

Use Of Nmr Logging To Obtain Estimates Of Hydraulic Conductivity In The High Plains Aquifer, Nebraska, Usa, Katherine Dlubac, Rosemary Knight, Yi-Qiao Song, Nate Bachman, Ben Grau, Jim Cannia, John Williams

United States Geological Survey: Staff Publications

Hydraulic conductivity (K) is one of the most important parameters of interest in groundwater applications because it quantifies the ease with which water can flow through an aquifer material. Hydraulic conductivity is typically measured by conducting aquifer tests or wellbore flow (WBF) logging. Of interest in our research is the use of proton nuclear magnetic resonance (NMR) logging to obtain information about water-filled porosity and pore space geometry, the combination of which can be used to estimate K. In this study, we acquired a suite of advanced geophysical logs, aquifer tests, WBF logs, and sidewall cores at the …

The Floodplain Food Web Mosaic: A Study Of Its Importance To Salmon And Steelhead With Implications For Their Recovery, J. Ryan Bellmore, Colden V. Baxter, Kyle Martens, Patrick J. Connolly

United States Geological Survey: Staff Publications

Although numerous studies have attempted to place species of interest within the context of food webs, such efforts have generally occurred at small scales or disregard potentially important spatial heterogeneity. If food web approaches are to be employed to manage species, studies are needed that evaluate the multiple habitats and associated webs of interactions in which these species participate. Here, we quantify the food webs that sustain rearing salmon and steelhead within a floodplain landscape of the Methow River, Washington, USA, a location where restoration has been proposed to restore side channels in an attempt to recover anadromous fishes. We …

Predictive Models For Escherichia Coli Concentrations At Inland Lake Beaches And Relationship Of Model Variables To Pathogen Detection, Donna S. Francy, Erin A. Stelzer, Joseph W. Duris, Amie M. G. Brady, John H. Harrison, Heather E. Johnson, Michael W. Ware

United States Geological Survey: Staff Publications

Predictive models, based on environmental and water quality variables, have been used to improve the timeliness and accuracy of recreational water quality assessments, but their effectiveness has not been studied in inland waters. Sampling at eight inland recreational lakes in Ohio was done in order to investigate using predictive models for Escherichia coli and to understand the links between E. coli concentrations, predictive variables, and pathogens. Based upon results from 21 beach sites, models were developed for 13 sites, and the most predictive variables were rainfall, wind direction and speed, turbidity, and water temperature. Models were not developed at sites …

Controls On Recent Alaskan Lake Changes Identified From Water Isotopes And Remote Sensing, Lesleigh Anderson, Jennifer Rover, Nikki Gaulager, Jean Birks

United States Geological Survey: Staff Publications

High-latitude lakes are important for terrestrial carbon dynamics and waterfowl habitat driving a need to better understand controls on lake area changes. To identify the existence and cause of recent lake area changes in the Yukon Flats, a region of discontinuous permafrost in north central Alaska, we evaluate remotely sensed imagery with lake water isotope compositions and hydroclimatic parameters. Isotope compositions indicate that mixtures of precipitation, river water, and groundwater source ~95% of the studied lakes. The remaining minority are more dominantly sourced by snowmelt and/or permafrost thaw. Isotope-based water balance estimates indicate 58% of lakes lose more than half …

Characterizing Ledaps Surface Reflectance Products By Comparisons With Aeronet, Field Spectrometer, And Modis Data, T.K. Maiersperger, P.L. Scaramuzza, L. Leigh, S. Shrestha, K.P. Gallo, C.B. Jenkerson, J.L. Dwyer

United States Geological Survey: Staff Publications

This study provides a baseline quality check on provisional Landsat Surface Reflectance (SR) products as generated by the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center using Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) software. Characterization of the Landsat SR products leveraged comparisons between aerosol optical thickness derived from LEDAPS and measured by Aerosol Robotic Network (AERONET), as well as reflectance correlations with field spectrometer and Moderate Resolution Imaging Spectroradiometer (MODIS) data. Results consistently indicated similarity between LEDAPS and alternative data products in longer wavelengths over vegetated areas with no adjacent water, while less reliable performance was …

Ice-Age Megafauna In Arctic Alaska: Extinction, Invasion, Survival, Daniel H. Mann, Pamela Groves, Michael L. Kunz, Richard E. Reanier, Benjamin V. Gaglioti

United States Geological Survey: Staff Publications

Radical restructuring of the terrestrial, large mammal fauna living in arctic Alaska occurred between 14,000 and 10,000 years ago at the end of the last ice age. Steppe bison, horse, and woolly mammoth became extinct, moose and humans invaded, while muskox and caribou persisted. The ice age mega fauna was more diverse in species and possibly contained 6x more individual animals than live in the region today. Mega faunal biomass during the last ice age may have been 30x greater than present. Horse was the dominant species in terms of number of individuals. Lions, short-faced bears, wolves, and possibly grizzly …

Origin Of The Sinai-Negev Erg, Egypt And Israel: Mineralogical And Geochemical Evidence For The Importance Of The Nile And Sea Level History, Daniel R. Muhs, Joel Roskin, Haim Tsoar, Gary Skipp, James Budahn, Amihai Sneh, Naomi Porat, Jean-Daniel Stanley, Itzhak Katra, Dan G. Blumberg

United States Geological Survey: Staff Publications

The Sinai-Negev erg occupies an area of 13,000 km² in the deserts of Egypt and Israel. Aeolian sand of this erg has been proposed to be derived from the Nile Delta, but empirical data supporting this view are lacking. An alternative source sediment is sand from the large Wadi El Arish drainage system in central and northern Sinai. Mineralogy of the Negev and Sinai dunes shows that they are high in quartz, with much smaller amounts of K-feldspar and plagioclase. Both Nile Delta sands and Sinai wadi sands, upstream of the dunes, also have high amounts of quartz relative …

Toxic Exposure Of Songbirds To Lead In The Southeast Missouri Lead Mining District, W. Nelson Beyer, J. Christian Franson, John B. French, Thomas May, Barnett A. Rattner, Valerie I. Shearn-Bochsler, Sarah E. Warner, John Weber, David Mosby

United States Geological Survey: Staff Publications

Mining and smelting in the Southeast Missouri Lead Mining District has caused widespread contamination of soils with lead (Pb) and other metals. Soils from three study sites sampled in the district contained from approximately 1,000–3,200 mg Pb/kg. Analyses of earthworms [33–4,600 mg Pb/kg dry weight (dw)] collected in the district showed likely high Pb exposure of songbirds preying on soil organisms. Mean tissue Pb concentrations in songbirds collected from the contaminated sites were greater (p < 0.05) than those in songbirds from reference sites by factors of 8 in blood, 13 in liver, and 23 in kidney. Ranges of Pb concentrations in livers (mg Pb/kg dw) were as follows: northern cardinal (Cardinalis cardinalis) = 0.11–3.0 (reference) and 1.3–30 (contaminated) and American robin (Turdus migratorius) = 0.43–8.5 (reference) and 7.6–72 (contaminated). Of 34 …

Robert B. Daugherty Water For Food Institute Annual Report 2012-2013, Monica Norby, Gillian Klucas

Daugherty Water for Food Global Institute: Literature

The Robert B. Daugherty Water for Food Institute was founded in 2010 to address the global challenge of achieving food security with less pressure on water resources through improved management of water in agricultural and food systems. We are committed to ensuring a water and food secure world without compromising the use of water for other human and environmental needs. Our approach is to extend the University of Nebraska’s expertise through strong partnerships with other universities and public and private sector organizations. Together we are developing research, education and engagement programs in a focused effort to increase food security while …

Loess And Its Geomorphic, Stratigraphic, And Paleoclimatic Significance In The Quaternary, Daniel R. Muhs

United States Geological Survey: Staff Publications

Loess is aeolian silt visible in the field as a sedimentary body. It covers a significant portion of the land surface of the Earth. Loess thickness, particle size, and carbonate content decrease downwind from sources, useful trends for paleowinds. Many loess sections consist of relatively thick deposits of mostly unaltered sediment with intercalated paleosols. Paleosols represent periods of landscape stability when loess deposition slowed significantly. Loess in most regions was deposited during glacial periods and paleosols formed during interglacial periods. Loess has the potential to record the timing and environment of glacial–interglacial cycles of the Quaternary on many continents.

Kentucky Water Resources Research Institute Annual Technical Report Fy 2012, Kentucky Water Resources Research Institute, University Of Kentucky

KWRRI Annual Technical Reports (USGS’s 104b Grant Program)

The 2012 Annual Technical Report for Kentucky consolidates reporting requirements for the Section 104(b) base grant award into a single document that includes; 1) a synopsis of each research project that was conducted during the period, 2) citations for related publications, reports, and presentations, 3) a description of information transfer activities, 4) a summary of student support during the reporting period, and 5) notable awards and achievements during the year.

Riparian Evapotranspiration In Nebraska, Brent M. Hall, David L. Rus

United States Geological Survey: Water Reports and Publications

With increasing demands being placed on the water resources of Nebraska, characterizing evapotranspiration (ET) from riparian vegetation has gained importance to water users and managers. This report summarizes and compares the results from several studies of the ET from cottonwood-dominated riparian forests, riparian grasslands, and common reed, Phragmites australis, in Nebraska. Reported results show that the highest seasonal ET amounts were associated with Phragmites australis, followed by riparian forests, with riparian grasslands experiencing the lowest total ET of the studied vegetation communities.