Physical Sciences and Mathematics Commons^™

Retrieval Of Aerosol Microphysical Properties From Aeronet Photopolarimetric Measurements: 1. Information Content Analysis, Xiaoguang Xu, Jun Wang

Department of Earth and Atmospheric Sciences: Faculty Publications

This paper is the first part of a two-part study that aims to retrieve aerosol particle size distribution (PSD) and refractive index from the multispectral and multiangular polarimetric measurements taken by the new-generation Sun photometer as part of the Aerosol Robotic Network (AERONET). It provides theoretical analysis and guidance to the companion study in which we have developed an inversion algorithm for retrieving 22 aerosol microphysical parameters associated with a bimodal PSD function from real AERONET measurements. Our theoretical analysis starts with generating the synthetic measurements at four spectral bands (440, 675, 870, and 1020 nm) with a Unified Linearized …

U.S. Drought Monitor, December 30, 2014, Brad Rippey

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for December 30, 2014 (12/30/14) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.

Enso Teleconnection Pattern Changes Over The Southeastern United States Under A Climate Change Scenario In Cmip5 Models, Ji-Hyun Oh, D.W. Shin, Steven D. Cocke, Guillermo A. Baigorria

School of Natural Resources: Faculty Publications

A strong teleconnection exists between the sea surface temperature (SST) over the tropical Pacific and the winter precipitation in the southeastern United States (SE US).This feature is adopted to validate the fidelity of Coupled Model Intercomparison Project Phase 5 (CMIP5) in this study. In addition, the authors examine whether the teleconnection pattern persists in the future under a global warming scenario. Generally, most of the eight selected models show a positive correlation between November SST over Ni˜no 3 region and December–February (DJF) mean daily precipitation anomalies over the SE US, consistent with the observation. However, the models with poor realization …

U.S. Drought Monitor, December 16, 2014, David Miskus

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for December 16, 2014 (12/16/14) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.

Integrating Path-Dependent Functionals On Yeh-Wiener Space, Ian Pierce, David Skough

Department of Mathematics: Faculty Publications

Denote by Ca,b(Q) the generalized two-parameter Yeh-Wiener space with associated Gaussian measure. We investigate several scenarios in which integrals of functionals on this space can be reduced to integrals of related functionals over an appropriate single-parameter generalized Wiener space Cˆa,ˆb[0, T ]. This extends some interesting results of R. H. Cameron and D. A. Storvick.

Modeling The Snow Surface Temperature With A One-Layer Energy Balance Snowmelt Model, J. You, D. G. Tarboton, C. H. Luce

School of Natural Resources: Faculty Publications

Snow surface temperature is a key control on and result of dynamically coupled energy exchanges at the snow surface. The snow surface temperature is the result of the balance between external forcing (incoming radiation) and energy exchanges above the surface that depend on surface temperature (outgoing longwave radiation and turbulent fluxes) and the transport of energy into the snow by conduction and meltwater influx. Because of the strong insulating properties of snow, thermal gradients in snow packs are large and nonlinear, a fact that has led many to advocate multiple layer snowmelt models over single layer models. In an effort …

Ferroelectric Polarization Dependent Interface Effects, Xiaohui Liu

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

Utilization of the switchable spontaneous polarization of nanometer scale ferroelectric materials offers a promising avenue for future nanoelectronic devices. In this dissertation, we use density-functional calculations and phenomenological modeling to explore the effects of interface termination on thin-film heterostructures, the effects of electron doping in bulk ferroelectric materials on ferroelectric stability, and the effects of ferroelectric polarization switching on the electronic and transport properties of interfaces.

For SrRuO₃/BaTiO₃/SrRuO₃ epitaxial heterostructures grown on SrTiO₃, we find that the built-in dipole at the BaO/RuO₂ terminated interface leads to a strong preference for one polarization. …

U.S. Drought Monitor, December 9, 2014, Anthony Artusa

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for December 9, 2014 (12/9/14) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.

Nebraska Center For Educational Science Outreach: A Clearinghouse Meeting People At Their Level To Make Stem Outreach Easier, Kiyomi D. Deards

University of Nebraska-Lincoln Libraries: Conference Presentations and Speeches

Identify key partners and stakeholders.

Conduct a STEM outreach needs assessment.

Develop a long-term plan.

1. How can faculty & staff support your STEM outreach?

2. How can you help faculty & staff with STEM outreach?

Combating Eutrophication: An Ecosystem Scale Analysis Of Aluminum Sulfate (Alum) Effectiveness Among Lakes, With Comparison To Alum And Biomanipulation Dual Treatment, Christa M. Webber

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

Eutrophic conditions in lakes and reservoirs in agricultural regions often drive summer blooms of toxic cyanobacteria. Aluminum sulfate (alum) applications are commonly used to control cyanobacteria blooms and restore water quality in eutrophic lakes. However, studies of alum treatments often lack true replication, comparison to reference lakes, or comparison to other restoration techniques, such as an alum and biomanipulation combined or “dual” treatments. Without these comparisons, the variation of treatment response between replicate lakes and restoration techniques remains uncertain. Therefore, I sought to assess how water quality is affected by multiple restoration techniques among geographically proximate (1.4 km²) …

A Niobium Deposit Hosted By A Magnetite-Dolomite Carbonatite, Elk Creek Carbonatite Complex, Nebraska, Usa, Michael J. Blessington

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The Elk Creek Carbonatite Complex (ECCC) is a large Early Cambrian carbonatite complex that intrudes Precambrian basement rocks in Southeast Nebraska. This dolomitic carbonatite complex includes a magnetite-dolomite rock with accessory barite, ilmenite, rutile, and quartz. This rock is identified by a characteristic enrichment in niobium due to accessory pyrochlore mineralization in the form of disseminations and inclusions in ilmenite and magnetite. Pyrochlore is also present in other carbonatite rocks in the complex as an accessory mineral with sporadic local high-grade intercepts in drill cores.

Carbonatite rock samples are characterized by transmitted-light microscopy, cathodoluminescent microscopy, backscattered electron imaging (BEI), and …

Analysis Of Drug Interactions With Lipoproteins By High Performance Affinity Chromatography, Matthew R. Sobansky

Department of Chemistry: Dissertations, Theses, and Student Research

High density lipoprotein (HDL), low density lipoprotein (LDL), and very low density lipoprotein (VLDL) are lipoproteins previously shown to bind many basic and neutral hydrophobic drugs in serum. These interactions impact the distribution, delivery, metabolism, and excretion of drugs and are important in determining drug activity, pharmacokinetics, and toxicity in the human body. Information about drug-lipoprotein interactions and the strength of these interactions can be useful in determining the distribution of drugs following administration.

The research presented in this dissertation uses high performance affinity chromatography (HPAC) and packed columns to study binding of the drug propranolol to immobilized lipoproteins such …

U.S. Drought Monitor, December 2, 2014, Anthony Artusa

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for December 2, 2014 (12/2/14) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.

Identification Of Groundwater Sources For Municipal Wells Using Geochemical Data On The Platte Alluvial Aquifer And Underlying Limestone At The Lincoln Water Well Field Near Ashland Nebraska, Juanita Cruz Torres

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Alluvial aquifer systems where pumping of municipal wells induces recharge from the adjacent river are the primary source of water for many cities. The city of Lincoln, NE has a primary water source in an alluvial aquifer adjacent to the Platte River. The Lincoln Water System manages the stream/aquifer system by using integrated models for a better understanding during periods of high stress such as a drought. The integrated models set the limestone aquifer as an impermeable boundary to understand the alluvial aquifer system without having a secondary water source. The limestone aquifer is permeable and the purpose of this …

Decision Support Tools To Address Climate Change: Climate Model - Land Surface Models, Zea Mays L. (Corn) Phenology And Evapotranspiration-Yield Sensitivity Models For Nebraska, Usa., Jane A. Okalebo

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

Nebraska's climate is highly variable and is expected to change in the future with anthropogenic global warming (AGW), resulting in warmer spring and summer temperatures coupled with more erratic rainfall events. This has strong implications for agriculture in the region, yet it is not clear that current modeling and decision-support tools are adequate to address these looming changes and provide planning, mitigation and adaptation strategies. To address climate change and its implications to agriculture in Nebraska, a set of robust decision support tools are very crucial. This study herein are divided into three chapters, with each chapter addressing a specific …

The Effect Of Weather During Rearing On Morphometric Traits Of Juvenile Cliff Swallows, Erin A. Roche, Mary Bomberger Brown, Charles R. Brown

School of Natural Resources: Faculty Publications

Episodes of food deprivation may change how nestling birds allocate energy to the growth of skeletal and feather morphological traits during development. Cliff swallows (Petrochelidon pyrrhonota) are colonial, insectivorous birds that regu­larly experience brief periods of severe weather–induced food deprivation during the nesting season which may affect offspring development. We investigated how annual variation in timing of rearing and weather were associated with length of wing and tail, skeletal traits, and body mass in juvenile cliff swallows reared in southwestern Nebraska during 2001–2006. As predicted under conditions of food deprivation, nestling skeletal and feather measurements were generally smaller …

Umphlett Qci Dec 2014, Natalie A. Umphlett

HPRCC Personnel Publications

Highlights for the Basin

Temperature and Precipitation Anomalies

Drought Conditions

Agriculture

Horticulture

Recreation and Tourism

3-Month Precipitation and Temperature Outlooks

Soil Moisture Conditions

Cloud Impacts On Pavement Temperature And Shortwave Radiation, Curtis L. Walker

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Forecast systems provide decision support for end-users ranging from the solar energy industry to municipalities concerned with road safety. Pavement temperature is an important variable when considering vehicle response to various weather conditions. A complex, yet direct relationship exists between tire and pavement temperatures. Literature has shown that as tire temperature increases, friction decreases which affects vehicle performance. Many forecast systems suffer from inaccurate radiation forecasts resulting in part from the inability to model different types of clouds and their influence on radiation. This research focuses on forecast improvement by determining how cloud type impacts pavement temperature and the amount …

Development And Application Of Combined Quantum Mechanical And Molecular Mechanical Methods, Rui Lai

Department of Chemistry: Dissertations, Theses, and Student Research

Compromising of computational cost and accuracy, combined quantum mechanical and molecular mechanical (QM/MM) methods are practical methods for studying large molecular systems. The use of induced dipole polarizable force fields can significantly improve the accuracy of MM and QM/MM methods. However, induced dipole models tend to overestimate the polarization energy at short interaction distances. Damping functions can be applied to reduce the over polarization. MM-MM damping schemes have been developed to correct the overestimated polarization between MM atoms; QM-MM damping scheme has not been developed. In this thesis, a QM-MM damping scheme is developed for the damping of the MM …

Enumeration Of Tilings Of Quartered Aztec Rectangles, Tri Lai

Department of Mathematics: Faculty Publications

We generalize a theorem of W. Jockusch and J. Propp on quartered Aztec diamonds by enumerating the tilings of quartered Aztec rectangles. We use subgraph replacement method to transform the dual graph of a quartered Aztec rectangle to the dual graph of a quartered lozenge hexagon, and then use Lindstr¨om-Gessel- Viennot methodology to find the number of tilings of a quartered lozenge hexagon.

Von Neumann Algebras And Extensions Of Inverse Semigroups, Allan P. Donsig, Adam H. Fuller, David R. Pitts

Department of Mathematics: Faculty Publications

In the 1970s, Feldman and Moore classified separably acting von Neumann algebras containing Cartan MASAs using measured equivalence re- lations and 2-cocycles on such equivalence relations. In this paper, we give a new classification in terms of extensions of inverse semigroups. Our approach is more algebraic in character and less point-based than that of Feldman-Moore. As an application, we give a restatement of the spectral theorem for bimodules in terms of subsets of inverse semigroups. We also show how our viewpoint leads naturally to a description of maximal subdiagonal algebras.

U.S. Drought Monitor, November 25, 2014, Eric Luebehusen

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for November 25, 2014 (11/25/14) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.

Ferroelectric Tunnel Junctions With Graphene Electrodes, Haidong Lu, Alexey Lipatov, Sangjin Ryu, D. J. Kim, H. Lee, M. Ye. Zhuravlev, Chang-Beom Eom, Evgeny Y. Tsymbal, Alexander Sinitskii, Alexei Gruverman

Evgeny Tsymbal Publications

Polarization-driven resistive switching in ferroelectric tunnel junctions (FTJs)—structures composed of two electrodes separated by an ultrathin ferroelectric barrier—offers new physics and materials functionalities, as well as exciting opportunities for the next generation of non-volatile memories and logic devices. Performance of FTJs is highly sensitive to the electrical boundary conditions, which can be controlled by electrode material and/or interface engineering. Here, we demonstrate the use of graphene as electrodes in FTJs that allows control of interface properties for significant enhancement of device performance. Ferroelectric polarization stability and resistive switching are strongly affected by a molecular layer at the graphene/BaTiO₃ interface. …

U.S. Drought Monitor, November 18, 2014, Eric Luebehusen

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for November 18, 2014 (11/18/14) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.

Boscor: Extending R From The Desktop To The Grid, Derek J. Weitzel, Jaime Frey, Marco Mambelli, Dan Fraser, Miha Ahronovitz, David Swanson

Holland Computing Center: Faculty Publications

In this paper, we describe a framework to execute R functions on remote resources from the desktop using Bosco. The R language is attractive to researchers because of its high level programming constructs which lower the barrier of entry for use. As the use of the R programming language in HPC and High Throughput Computing (HTC) has grown, so too has the need for parallel libraries in order to utilize computing resources.

Bosco is middleware that uses common protocols to manage job submissions to a variety of remote computational platforms and resources. The researcher is able to control and monitor …

Agricultural Advisors As Climate Information Intermediaries: Exploring Differences In Capacity To Communicate Climate, Tonya Haigh, Lois Wright Morton, Maria Carmen Lemos, Cody Knutson, Linda Stalker Prokopy, Yun Jia Lo, Jim Angel

Drought Mitigation Center: Faculty Publications

Although agricultural production faces chronic stress associated with extreme precipitation events, high temperatures, drought, and shifts in climate conditions, adoption of climate information into agricultural decision making has been relatively limited. Agricultural advisors have been shown to play important roles as information intermediaries between scientists and farmers, brokering, translating, and adding value to agronomic and economic information of use in agricultural management decision making. Yet little is known about the readiness of different types of agricultural advisors to use weather and climate information to help their clients manage risk under increasing climate uncertainty. More than 1700 agricultural advisors in four …

U.S. Drought Monitor, November 11, 2014, Matthew Rosencrans

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for November 11, 2014 (11/11/14) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.

The Development Of A Valid And Reliable Biogeochemistry Concept Inventory, Chris Mead

DBER Speaker Series

Concept inventories are a commonly used tool to measure conceptual understanding. To date, concept inventories have been published for geology, chemistry, and biology, but no instrument has been designed to measure conceptual understanding at the intersection of those fields. To fill that gap, we constructed a 32‐item biogeochemistry concept inventory (BGC‐CI). Item response theory analysis, using the Rasch model, shows the BGC‐CI is a reliable and valid tool to measure the biogeochemistry knowledge of science majors. Because biogeochemistry is an interdisciplinary field, we were concerned about the unidimensionality of the instrument. However, our analysis showed the BGC‐CI to be acceptably …

U.S. Drought Monitor, November 4, 2014, Matthew Rosencrans

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for November 4, 2014 (11/4/14) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.

Translating Aboveground Cosmic-Ray Neutron Intensity To High-Frequency Soil Moisture Profiles At Sub-Kilometer Scale, R. Rosolem, T. Hoar, A. Arellano, J. L. Anderson, W. J. Shuttleworth, X. Zeng, Trenton E. Franz

School of Natural Resources: Faculty Publications

Above-ground cosmic-ray neutron measurements provide an opportunity to infer soil moisture at the subkilometer scale. Initial efforts to assimilate those measurements have shown promise. This study expands such analysis by investigating (1) how the information from aboveground cosmic-ray neutrons can constrain the soil moisture at distinct depths simulated by a land surface model, and (2) how changes in data availability (in terms of retrieval frequency) impact the dynamics of simulated soil moisture profiles. We employ ensemble data assimilation techniques in a “nearly-identical twin” experiment applied at semi-arid shrubland, rainfed agricultural field, and mixed forest biomes in the USA. The performance …