Physical Sciences and Mathematics Commons^™

The Role Of Eolian-Fluvial Interactions And Dune Dams In Landscape Change, Late Pleistocene-Holocene, Mojave Desert, Usa, Mark R. Sweeney, Eric V. Mcdonald, Lucas P. Chabela, Paul R. Hanson

School of Natural Resources: Faculty Publications

The formation of the Kelso Dunes in the eastern Mojave Desert, California, was a landscape-changing event triggered by an increase in sediment supply that followed the incision of Afton Canyon by the Mojave River ca. 25 ka. Eastward migration of sand dunes occurred along a well-defined eolian trans­port corridor. Dunes temporarily blocked washes resulting in substantial aggradation of eolian and fluvial sediments. Stratigraphic exposures reveal numerous fining-up sequences with interbedded eolian sands that provide evidence of dune dams and subsequent aggradation. Luminescence ages reveal that dune blocking and aggradation correspond to a regional pulse of alluvial fan sedimentation that occurred …

Reinvestigation Of The Intrinsic Magnetic Properties Of (Fe1-Xcox)2b Alloys And Crystallization Behavior Of Ribbons, Tej Nath Lamichhane, Olena Palasyuk, Vladimir P. Antropov, Ivan A. Zhuravlev, Kirill Belashchenko, Ikenna C. Nlebedim, Kevin W. Dennis, Anton Jesche, Matthew J. Kramer, Sergey L. Bud'ko, R. William Mccallum, Paul C. Canfield, Valentin Taufour

Kirill Belashchenko Publications

New determination of the magnetic anisotropy from single crystals of (Fe_1-xCo_x)2B alloys are presented. The anomalous temperature dependence of the anisotropy constant is discussed using the standard Callen-Callen theory, which is shown to be insufficient to explain the experimental results. A more material specific study using first-principles calculations with disordered moments approach gives a much more consistent interpretation of the experimental data. Since the intrinsic properties of the alloys with x=0.3-0.35 are promising for permanent magnets applications, initial investigation of the extrinsic properties are described, in particular the crystallization of melt spun ribbons with Cu, Al, …

Helmholtz Spacing Of Thin Rectangular Magnetic Field Coils, Karl J. Ahrendsen, Sarah Reyes, Timothy J. Gay

Timothy J. Gay Publications

In this Note, we discuss the Helmholtz spacing for a pair of thin rectangular coils of arbitrary aspect ratio and consider how best to use such coils to compensate for Earth’s magnetic field along the coils’ Cartesian symmetry axes. Such coils are frequently used in conjunction with charged-particle beam machines. The Helmholtz spacing varies non-monotonically between that for square coils and that for four optimally spaced infinite wires. We consider other coil spacings that extend the length over which the field varies by less than some tolerance along the Cartesian symmetry axes. The calculations also provide a convenient means to …

Spotted Owls And Forest Fire: Comment, Gavin M. Jones, R. J. Gutiérrez, William M. Block, Peter C. Carlson, Emily J. Comfort, Samuel A. Cushman, Raymond J. Davis, Stephanie A. Eyes, Alan B. Franklin, Joseph L. Ganey, Shaula Hedwall, John J. Keane, Rodd Kelsey, Damon B, Lesmeister, Malcolm P. North, Susan L. Roberts, Jeremy T. Rockweit, Jamie S. Sanderlin, Sarah C. Sawyer, Ben Solvesky, Douglas J. Tempel, Ho Yi Wan, A. Leroy Westerling, Gary C. White, M. Zachariah Peery

United States Department of Agriculture Wildlife Services: Staff Publications

Western North American forest ecosystems are experiencing rapid changes in disturbance regimes because of climate change and land use legacies (Littell et al. 2018). In many of these forests, the accumulation of surface and ladder fuels from a century of fire suppression, coupled with a warming and drying climate, has led to increases in the number of large fires (Westerling 2016) and the proportion of areas burning at higher severity (Safford and Stevens 2017, Singleton et al. 2018). While the annual area burned by fire is still below historical levels (Taylor et al. 2016), some forest types in the west …

Seasonal Grassland Productivity Forecast For The U.S. Great Plains Using Grass-Cast, Melannie D. Hartman, William J. Parton, Justin D. Derner, Darin K. Schulte, William K. Smith, Dannele E. Peck, Ken A. Day, Stephen J. Del Grosso, Susan Lutz, Brian Fuchs, Maosi Chen, Wei Gao

Drought Mitigation Center: Faculty Publications

Every spring, ranchers in the drought-prone U.S. Great Plains face the same difficult challenge —trying to estimate how much forage will be available for livestock to graze during the upcoming summer grazing season. To reduce this uncertainty in predicting forage availability, we developed an innovative new grassland productivity forecast system, named Grass-Cast, to provide science-informed estimates of growing season aboveground net primary production (ANPP). Grass-Cast uses over 30 yr of historical data including weather and the satellite-derived normalized vegetation difference index (NDVI)—combined with ecosystem modeling and seasonal precipitation forecasts—to predict if rangelands in individual counties are likely to produce below-normal, …

A Stable Version Of Harbourne's Conjecture And The Containment Problem For Space Monomial Curves, Eloísa Grifo

Department of Mathematics: Faculty Publications

The symbolic powers I(ⁿ⁾ of a radical ideal I in a polynomial ring consist of the functions that vanish up to order n in the variety defined by I. These do not necessarily coincide with the ordinary algebraic powers In, but it is natural to compare the two notions. The containment problem consists of determining the values of n and m for which I(ⁿ⁾⊆Im holds. When I is an ideal of height 2 in a regular ring, I(³⁾⊆I2 may fail, but we …

Photodissociation Of Aqueous I 3 - Observed With Liquid-Phase Ultrafast Mega-Electron-Volt Electron Diffraction, K. Ledbetter, E. Biasin, J. P.F. Nunes, Martin Centurion, K. J. Gaffney, M. Kozina, M. F. Lin, X. Shen, J. Yang, X. J. Wang, T. J. A. Wolf, A. A. Cordones

Martin Centurion Publications

Developing femtosecond resolution methods for directly observing structural dynamics is critical to understanding complex photochemical reaction mechanisms in solution. We have used two recent developments, ultrafast mega-electron-volt electron sources and vacuum compatible sub-micron thick liquid sheet jets, to enable liquid-phase ultrafast electron diffraction (LUED). We have demonstrated the viability of LUED by investigating the photodissociation of tri-iodide initiated with a 400 nm laser pulse. This has enabled the average speed of the bond expansion to be measured during the first 750 fs of dissociation and the geminate recombination to be directly captured on the picosecond time scale.

Introduction To Special Section: Integrated Geophysical Imaging, Irina Filina, Rao Yalamanchili, Simone Re, Daniele Colombo, Antony Price, Vsevolod Egorov, Guimin Liu

Department of Earth and Atmospheric Sciences: Faculty Publications

This special section illustrates the value of integration with nonseismic geophysical methods, namely potential fields (gravity and magnetics) and electric and electromagnetic techniques. The primary objective is to overcome the overall underappreciation of these methods as exploration tools. We provide their brief overview and present nine case studies illustrating how the integrative approach to geophysical data analysis influences the overall result and reduces the uncertainty of the derived solution.

Toward The Standardization Of Mesoscale Meteorological Networks, Christopher Fiebrich, Kevin Brinson, Rezaul Mahmood, Stuart Foster, Megan Schargorodski, Nathan L. Edwards, Christopher A. Redmond, Jennie R. Atkins, Jeffrey Andresen, Xiaomao Lin

School of Natural Resources: Faculty Publications

Although they share many common qualities in design and operation, mesonetworks across the United States were established independently and organically over the last several decades. In numerous instances, the unique ways each network matured and developed new protocols has led to important lessons learned. These experiences have been shared in informal ways among various network operators over the years to promote reliable operation. As existing networks begin to introduce new sensors and technologies, and as new networks come online, there is a common need for guidance on best practices. This paper aims to formally provide recommendations to improve and harmonize …

Significance Statements Communicate Our Science More Widely, Rezaul Mahmood

School of Natural Resources: Faculty Publications

The American Meteorological Society (AMS) mission statement specifically calls for advancing ‘‘the atmospheric and related sciences . . . for the benefit of society.’’ To further the goal of communicating the importance of the science in our journals more widely, AMS is encouraging the inclusion in submitted papers of a ‘‘significance statement,’’ written in plain language and aimed at an educated layperson without formal training or education in the atmospheric and related sciences. As of 6 November 2020, Earth Interactions authors now have the option to include a significance statement with their submitted papers. A significance statement is an explanation …

Data Availability Principles And Practice, Rezaul Mahmood, Joseph A. Santanello, Xiaoyang Zhang

School of Natural Resources: Faculty Publications

Science requires evidence. Making data available lets other scientists confirm results, uncover errors, or find new insights. Moreover, gathering data can be expensive and time consuming. Since the same data can be used for a range of purposes, making data available can be an efficient use of limited research resources. Doing so can also improve traceability and, thus, accountability, when it comes to research findings. These reasons and more lie behind recent efforts to promote data availability. The American Meteorological Society (AMS) recently updated its data policy guidelines (https://www.ametsoc.org/ index.cfm/ams/publications/ethical-guidelines-and-ams-policies/data-policy-and-guidelines/) to require, among other things, that papers in its journals …

Anthropogenic Change On The Distribution Of Marine Megafauna And Their Prey, Baylie Fadool

Honors Theses

Anthropogenic change is impacting the distribution and survival of marine megafauna and their prey. Humans are changing every aspect of the marine environment, with effects reaching as large as changing the composition of marine environments to directly overexploiting species through the fishing industry. The role that marine megafauna play in balancing ecosystems, including as top apex predators, leads to detrimental results in the absences and population declines of these species. Migrations and declines due to threats on marine apex predator species will alter their environments by causing mesopredator release and changes in community structure, which is often associated with reduced …

Loci Associated With Antibody Response In Feral Swine (Sus Scrofa) Infected With Brucella Suis, Courtney F. Pierce, Vienna R. Brown, Steven C. Olsen, Paola Boggiatto, Kerri Pedersen, Ryan S. Miller, Scott E. Speidel, Timothy J. Smyser

United States Department of Agriculture Wildlife Services: Staff Publications

Feral swine (Sus scrofa) are a destructive invasive species widespread throughout the United States that disrupt ecosystems, damage crops, and carry pathogens of concern for the health of domestic stock and humans including Brucella suis—the causative organism for swine brucellosis. In domestic swine, brucellosis results in reproductive failure due to abortions and infertility. Contact with infected feral swine poses spillover risks to domestic pigs as well as humans, companion animals, wildlife, and other livestock. Genetic factors influence the outcome of infectious diseases; therefore, genome wide association studies (GWAS) of differential immune responses among feral swine can provide …

A Review Of Avian Influenza A Virus Associations In Synanthropic Birds, Susan A. Shriner, J. Jeffrey Root

United States Department of Agriculture Wildlife Services: Staff Publications

Avian influenza A viruses (IAV) have received significant attention due to the threat they pose to human, livestock, and wildlife health. In this review, we focus on what is known about IAV dynamics in less common avian species that may play a role in trafficking IAVs to poultry operations. Specifically, we focus on synanthropic bird species. Synanthropic species, otherwise known as peridomestic, are species that are ecologically associated with humans and anthropogenically modified landscapes, such as agricultural and urban areas. Aquatic birds such as waterfowl and shorebirds are the species most commonly associated with avian IAVs, and are generally considered …

Satellite-Based Monitoring Of Irrigation Water Use: Assessing Measurement Errors And Their Implications For Agricultural Water Management Policy, T. Foster, Taro Mieno, Nicholas Brozovic

Daugherty Water for Food Global Institute: Faculty Publications

Reliable accounting of agricultural water use is critical for sustainable water management. However, the majority of agricultural water use is not monitored, with limited metering of irrigation despite increasing pressure on both groundwater and surface water resources in many agricultural regions worldwide. Satellite remote sensing has been proposed as a low-cost and scalable solution to fill widespread gaps in monitoring of irrigation water use in both developed and developing countries, bypassing the technical, socioeconomic, and political challenges that to date have constrained in situ metering. In this paper, we show through a systematic meta-analysis that the relative accuracy of different …

Tapping Twitter Data For Analyzing And Visualizing Public Sentiments On Censorship, Naveen Kumar Yadav, Akhilesh K.S. Yadav

Library Philosophy and Practice (e-journal)

The main objective of this research study is to analyse and visualize Twitter data with tags “#Censorship”. A connection was established with twitter using Twitter API, and receiving the tweets on Google Spreadsheets. Data visualization was performed using various tools such as Voyant Tools, Tableau, Google Spreadsheet and Orange in order to generate different visualizations based upon, language, geographical areas, retweets etc. The sentiment analysis was performed for the sentiments that were attached to the given set of data by the public in their respective tweets. The 23680 tweets were retrieved during the data collection time and there were 13,771 …

Investigating Factors Predicting Effective Learning In A Cs Professional Development Program For K-12 Teachers, Patrick Morrow

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

The demand for K-12 Computer Science (CS) education is growing and there is not an adequate number of educators to match the demand. Comprehensive research was carried out to investigate and understand the influence of a summer two-week professional development (PD) program on teachers’ CS content and pedagogical knowledge, their confidence in such knowledge, their interest in and perceived value of CS, and the factors influencing such impacts. Two courses designed to train K-12 teachers to teach CS, focusing on both concepts and pedagogy skills were taught over two separate summers to two separate cohorts of teachers. Statistical and SWOT …

Interval Estimation Of Proportion Of Second-Level Variance In Multi-Level Modeling, Steven Svoboda

The Nebraska Educator: A Student-Led Journal

Physical, behavioral and psychological research questions often relate to hierarchical data systems. Examples of hierarchical data systems include repeated measures of students nested within classrooms, nested within schools and employees nested within supervisors, nested within organizations. Applied researchers studying hierarchical data structures should have an estimate of the intraclass correlation coefficient (ICC) for every nested level in their analyses because ignoring even relatively small amounts of interdependence is known to inflate Type I error rate in single-level models. Traditionally, researchers rely upon the ICC as a point estimate of the amount of interdependency in their data. Recent methods utilizing an …

A Detailed Assessment Of Groundwater Quality In The Kabul Basin, Afghanistan, And Suitability For Future Development, Hussain Ali Jawadi, Jay Sagin, Daniel D. Snow

Nebraska Water Center: Faculty Publications

Abstract: Kabul is one of the most populated cities in Afghanistan and providing resources to support this population in an arid climate presents a serious environmental challenge. The current study evaluated the quality of local Kabul Basin groundwater to determine its suitability water for drinking and irrigation purposes now and into the future. This aim was aided through groundwater parameter assessment as well as determination ofWater Quality Index (WQI) developed from 15 observation points near the city. The results of our physicochemical analysis illustrate that groundwater in the majority of areas of the Kabul Basin is not generally suitable for …

A Detailed Assessment Of Groundwater Quality In The Kabul Basin, Afghanistan, And Suitability For Future Development, Hussain Ali Jawadi, Jay Sagin, Daniel D. Snow

Nebraska Water Center: Faculty Publications

Kabul is one of the most populated cities in Afghanistan and providing resources to support this population in an arid climate presents a serious environmental challenge. The current study evaluated the quality of local Kabul Basin groundwater to determine its suitability water for drinking and irrigation purposes now and into the future. This aim was aided through groundwater parameter assessment as well as determination ofWater Quality Index (WQI) developed from 15 observation points near the city. The results of our physicochemical analysis illustrate that groundwater in the majority of areas of the Kabul Basin is not generally suitable for human …

High-Resolution Movies Of Molecular Rotational Dynamics Captured With Ultrafast Electron Diffraction, Yanwei Xiong, Kyle J. Wilkin, Martin Centurion

Martin Centurion Publications

Imaging the structure of molecules during a photoinduced reaction is essential for elucidating reaction mechanisms. This requires high spatiotemporal resolution to capture nuclear motions on the femtosecond and subangstrom scale, and a sufficiently high signal level to sample their continuous evolution with high fidelity. Here we show that, using high-repetition-rate ultrafast electron diffraction, we can accurately reconstruct a movie of the coherent rotational motion of laser-aligned nitrogen molecules. We have used a tabletop 90-keV photoelectron gun to simultaneously achieve high temporal resolution of 240 fs full width at half maximum and an electron beam current that is more than an …

Resource Selection At Homesites By Wolves And Eastern Coyotes In A Canis Hybrid Zone, Teresa Oliveira, John F. Benson, Connor Thompson, Brent R. Patterson

School of Natural Resources: Faculty Publications

We modeled resource selection by wolves (Canis spp.), eastern coyotes (C. latrans), and admixed canids during the pup-rearing season at den and rendezvous sites (collectively, homesites) within a largely unprotected landscape proposed as the recovery zone for federally and provincially threatened eastern wolves (C. lycaon) in Ontario, Canada. Overall, canids selected wetlands, while avoiding secondary roads and open-structure rock-grass habitat patches. Packs with greater wolf ancestry selected wetlands and tertiary roads more strongly, while avoiding mixed conifer-hardwood forests. Contrary to our prediction, canids with greater coyote ancestry did not establish homesites closer to roads, which likely mitigated their risk of …

Developing A Model Of Graduate Teaching Assistant Teacher Efficacy: How Do High And Low Teacher Efficacy Teaching Assistants Compare?, Cody R. Smith, Cesar Delgado

School of Natural Resources: Faculty Publications

Graduate teaching assistants (TAs) are often responsible for teaching introductory courses to undergraduate science, technology, engineering, and mathematics students. The TAs are usually novices at teaching, and an important factor in their resilience and persistence in the face of inevitable challenges is self-efficacy. Little is known about what affects TA teacher efficacy or whether and how high- and low-efficacy TAs differ in their development as teachers. Bridging these gaps in the literature will inform best practices in developing and implementing professional development (PD) for TAs. Using a mixed-methods sequential exploratory research design, this study found differences in high- and low-efficacy …

Implementation Of An Occupancy-Based Monitoring Protocol For A Widespread And Cryptic Species, The New England Cottontail (Sylvilagus Transitionalis), Colin P. Shea, Mitchell J. Eaton, Darryl I. Mackenzie

United States Geological Survey: Staff Publications

Context. Designing effective long-term monitoring strategies is essential for managing wildlife populations. Implementing a cost-effective, practical monitoring program is especially challenging for widespread but locally rare species. Early successional habitat preferred by the New England cottontail (NEC) has become increasingly rare and fragmented, resulting in substantial declines from their peak distribution in the mid-1900s. The introduction of a possible competitor species, the eastern cottontail (EC),may also have played a role. Uncertainty surrounding how these factors have contributed to NEC declines has complicated management and necessitated development of an appropriate monitoring framework to understand possible drivers of distribution and dynamics.

Aims. …

A Profile Shape Correction To Reduce The Vertical Sensitivity Of Cosmic-Ray Neutron Sensing Of Soil Moisture, Lena M. Scheiffele, Gabriele Baroni, Trenton E. Franz, Jannis Jakobi, Sascha E. Oswald

School of Natural Resources: Faculty Publications

n recent years, cosmic-ray neutron sensing (CRNS) has shown a large potential among proximal sensing techniques to monitor soil moisture noninvasively, with high frequency and a large support volume (radius up to 240 m and sensing depth up to 80 cm). This signal is, however, more sensitive to closer distances and shallower depths. Inherently, CRNS-derived soil moisture is a spatially weighted value, different from an average soil moisture as retrieved by a sensor network. In this study, we systematically test a new profile shape correction on CRNS-derived soil moisture, based on additional soil moisture profile measurements and vertical unweighting, which …

Reliability And Validity Of Scales Assessing Anxiety Associated With Information Related Tasks: A Systematic Review, Muhammad Asif Naveed, Sajjad Ullah Jan, Mumtaz Ali Anwar

Library Philosophy and Practice (e-journal)

This research carried out a systematic review of the evidence of reliability and validity of scales available in studies reporting surveys of individuals to assess anxiety associated with information related tasks such as library anxiety, information seeking anxiety, and information anxiety. A systematic search using keywords ‘library anxiety’, ‘information anxiety’, 'information seeking anxiety', and 'information seeking' AND 'anxiety' was carried in Web of Science, Scopus, LISA, and LISTA to identify the relevant literature. This review included those studies reporting the use of any scale assessing information related anxiety, and published in the English language, and included all type of documents …

Water Current, Volume 52, No. 3, Fall 2020

Water Current Newsletter

NWC Convenes August 3 Mini-Conference

Water and Public Safety

University Receives $5 million Gift to Create Program on Water, Climate and Health

An Open-Sourced, Web-Based Application To Improve Our Ability To Understand Hunter And Angler Purchasing Behavior From License Data, Nathaniel B. Price, Christopher J. Chizinski, Joseph J. Fontaine, Kevin L. Pope, Micaela Rahe, Jeff Rawlinson

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

State fish and wildlife agencies rely on hunters and anglers (i.e., sportspersons) to fund management actions through revenue generated from license sales and excise taxes on hunting and fishing equipment. There is a need to develop new techniques that bridge the information gap on participation and provide agencies with an understanding of sportspersons at a resolution that can more directly inform efforts to engage sportspersons. Monitoring sportsperson participation using information about their license-purchasing behavior has the potential to reveal important patterns in recruitment (first-time purchase of a hunting or fishing license), retention (continued purchase of licenses across multiple years), and …

Tributes To Rick Edwards Upon His Retirement, Robert F. Diffendal Jr., Michael Farrell, Michael David Forsberg, Maurice Godfrey, John J. Janovy Jr., Katie Nieland, Linda Pratt, Rebecca S Wingo, David J. Wishart, George E. Wolf, Peter Longo, John R. Wunder

Robert F. Diffendal, Jr., Publications

I understand that you will be retiring from UNL in August. I wanted to express my sadness that you will be leaving the Center for Great Plains Studies, but am glad that you will now be able to perhaps enjoy life even more without having to do the administrative tasks that go with being the director of any organization. (RFD)

Cold Sintering Diisopropylamonium Bromide To Form Organic Ceramic Pellets, Darren Armstrong

Honors Theses

Diisopropylamonium bromide is an organic ferroelectric compound. Standard sample preparation methods either require a powder or a single crystal. Certain measurements cannot be done on powders due to equipment limitations, and single crystals are difficult and time consuming to produce and handle. Cold sintering is a relatively new process that allows the creation of ceramics. The original cold sintering process was adapted to work for diisopropylamonium bromide. This allows the creation of ceramics with a large surface area. These pellets can achieve up to 95% of the theoretical maximum density. While the pellets are currently unsuitable for electric testing at …