Physical Sciences and Mathematics Commons^™

Development Of Novel Dart Tofms Analytical Techniques For The Identification Of Organic Contamination On Spaceflight-Related Substrates And Aqueous Media, Kathleen Loftin

Electronic Theses and Dissertations

Organic contamination on spaceflight hardware is an ongoing concern for spaceflight safety. In addition, for the goal of analyzing for possible evidence of extra-terrestrial life, it is necessary to consider the presence of terrestrial contamination. This paper will introduce and evaluate a new method using a direct analysis real time (DART) ionization source paired with a high resolution time of flight mass spectrometer (TOFMS) for the determination of organic contamination involved in spaceflight hardware and ground support materials. This novel analytical technique has significant advantages over current methodologies. Materials analyzed in this study were historically considered as probable contaminants in …

Bootstrap Enhanced N-Dimensional Deformation Of Space With Acoustic Resonance Spectroscopy, David John Link

University of Kentucky Doctoral Dissertations

Acoustic methods can often be used with limited or no sample preparations making them ideal for rapid process analytical technologies (PATs). This dissertation focuses on the possible use of acoustic resonance spectroscopy as a PAT in the pharmaceutical industry. Current good manufacturing processes (cGMP) need new technologies that have the ability to perform quality assurance testing on all products. ARS is a rapid and non destructive method that has been used to perform qualitative studies but has a major drawback when it comes to quantitative studies. Acoustic methods create highly non linear correlations which usually results in high level computations …

Analysis Of Security Measures For Sequences, Ramakanth Kavuluru

University of Kentucky Doctoral Dissertations

Stream ciphers are private key cryptosystems used for security in communication and data transmission systems. Because they are used to encrypt streams of data, it is necessary for stream ciphers to use primitives that are easy to implement and fast to operate. LFSRs and the recently invented FCSRs are two such primitives, which give rise to certain security measures for the cryptographic strength of sequences, which we refer to as complexity measures henceforth following the convention. The linear (resp. N-adic) complexity of a sequence is the length of the shortest LFSR (resp. FCSR) that can generate the sequence. Due …

Just Add Water: Colonisation, Water Governance, And The Australian Inland, Leah Maree Gibbs

Faculty of Science - Papers (Archive)

Water has played a key role in the development of the Australian inland and the nation. For European colonists, the dry and variable landscape challenged ideas about nature imported from northern temperate regions. I argue first, that colonists brought with them ideas for ordering nature and tools for transforming landscapes that led to inappropriate and destructive water management and the silencing of local voices and knowledge systems. Secondly, colonial patterns of ordering and transforming landscapes are ongoing, but new ways of governing water, which challenge colonialism, are emerging. In the first section of the paper I discuss colonial relationships with …

A Flexible Solvolysis Experiment For The Undergraduate Organic Laboratory, John J. Esteb, John R. Magers, Luanne M. Mcnulty, Paul Morgan

Scholarship and Professional Work - LAS

A simple SN1 reaction is presented that uses bromotriphenylmethane and a range of oxygen-based nucleophiles including water and various alcohols. This procedure represents a process that affords easy isolation of solid products. Typical student yields ranged from 17–128% with the average yield of 50%. Students obtained products with a melting point range of 140 to 164 °C. This procedure offers multiple ways to adapt this experiment from a straight solvolysis reaction to a discovery-based experiment that explores the effect of nucleophile (for a more advanced group) or the method of product isolation.

Estimating Hydraulic Conductivity From Drainage Patterns Derived From Dem-A Case Study In The Oregon Cascades, B. P. Grudzinski, W. Luo, Darryll T. Pederson

Department of Earth and Atmospheric Sciences: Faculty Publications

Hydraulic conductivity is an important parameter in hydrology which describes the ease with which water moves through porous media. This parameter is also important in understanding the hydrology of Mars. On Earth, this parameter can be measured by conducting controlled experiments in laboratories or conducting pumping tests in the field. This study introduces a new method of estimating hydraulic conductivity from drainage dissection pattern derived from digital elevation model (DEM). This method can be applied to Mars if it is robustly tested on Earth.

Biostratigraphy Of The Hunter Creek Sandstone, Verdi Basin, Washoe County, Nevada, Thomas S. Kelly, Ross Secord

Department of Earth and Atmospheric Sciences: Faculty Publications

The Hunter Creek Sandstone of the Verdi Basin, Nevada, yielded a succession of superposed continental faunal assemblages ranging in age from the late Clarendonian (late Miocene) through the late Blancan (late Pliocene) in the North American land mammal age framework, or ca. 10.5-2.5 Ma. We describe two new local faunas from the Hunter Creek Sandstone: the East Verdi local fauna, of late-medial to late Clarendonian age, which includes Dinohippus cf. D. leardi, Camelidae, ?Antilocapridae, and Mammutidae or Gomphotheriidae; and the Mogul local fauna, of Hemphillian age, which includes Dinohippus sp., Rhinocerotidae, Camelidae (at least two species), Mammut sp., and …

The Nature And Origin Of Decadal To Millennial Scale Climate Variability In The Southern Tropics Of South America: The Holocene Record Of Lago Umayo, Peru, Paul A. Baker, Sherilyn C. Fritz, Stephen J. Burns, Erik Ekdahl, Catherine A. Rigsby

Department of Earth and Atmospheric Sciences: Faculty Publications

This paper serves two purposes: to review current ideas about the nature and forcing of decadal to millennial scale precipitation variation in the southern tropics of South America during the late Quaternary and to present a new methodology for the reconstruction of precipitation as applied to a Holocene stable isotopic record of carbonate sediments in a tropical Andean lake, Lago Umayo, Peru. The basic thesis of the first part of the paper is that, although modern instrumental records suffice for deducing climate variability at decadal and shorter time scales, these records cannot adequately characterize the nature and forcing of lower-frequency …

Evolution Of The Cretaceous Calcareous Nanofossil Genus Eiffellithus And Its Biostratigraphic Significance, Jamie L. Shamrock, David K. Watkins

Department of Earth and Atmospheric Sciences: Faculty Publications

The calcareous nanofossil genus Eiffellithus is an important taxon of mid- to Upper Cretaceous marine sediments in biostratigraphy and paleoceanography. The definition of species within Eiffellithus have been both broadly interpreted and variably applied by nanofossil workers. This is particularly true for the Eiffellithus eximius plexus. While the taxonomy of mid-Cretaceous Eiffellithus species has recently been well-defined, the remaining 35 m.y. history of the genus has not been closely examined. Our investigation of Cenomanian to Maastrichtian sediments from the Western Interior Seaway, Gulf of Mexico, and Western Atlantic gives rise to six new species of Eiffellithus that can be reliably …

Clues To The Medieval Destabilization Of The Nebraska Sand Hills, Usa, From Ancient Pocket Gopher Burrows, Rebecca L. Schmeisser, David B. Loope, David A. Wedin

Department of Earth and Atmospheric Sciences: Faculty Publications

The Nebraska Sand Hills are a stabilized dune field in the central United States that reflect past conditions of drought. The most recent drought, known as the Medieval Climatic Anomaly, occurred from A.D. 900 to A.D. 1300 and had an enormous effect on the thriving prairie ecosystem, which included large populations of the plains pocket gopher (Geomys bursarius). Burrows of these organisms across a paleosol-eolian sand boundary in the Sand Hills indicate abrupt climate change during the transition from stabilized to active dune field and from humid to arid conditions. Medieval gophers tunneled at greater depths below the …

Energies For The High- L Rydberg States Of Helium: Asymptotic Analysis, R. El-Wazni, Gordon W. F. Drake

Physics Publications

The asymptotic expansion method based on a core polarization potential for the Rydberg electron is reviewed and extended to the high angular momentum states of helium up to L=15. A comparison with recent large-scale configuration interaction calculations for the nonrelativistic energies shows that there is good agreement for L=7, but there are serious systematic disagreements for the states of higher angular momentum. A possible explanation is that there is an important class of configurations missing from the CI calculations. © 2009 The American Physical Society.

2009 Chesapeake Bay Bridge Tunnel Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans

Miscellaneous

These calendars are produced monthly using David Evans' Tidecal.

Mate Choice For Nonadditive Genetic Benefits And The Maintenance Of Genetic Diversity In Song Sparrows, Bryan D. Neff, Trevor E. Pitcher

Great Lakes Institute for Environmental Research Publications

The lek paradox asserts that strong directional selection via female choice should deplete additive genetic variation in fitness and consequently any benefit to females expressing the preference. Recently, we have provided a novel resolution to the paradox by showing that nonadditive genetic effects such as overdominance can be inherited from parent to offspring, and populations with females that express a mating preference for outbred males maintain higher genetic variation than populations with females that mate randomly. Here, we test our dynamic model using empirical data previously published from a small island population of song sparrows (Melospiza melodia). The model assumes …

How Can Information And Communication Technology Bring About Development? An Information Architecture For Guiding Interventions In Developing Regions, Mehruz Kamal, Sajda Qureshi

Information Systems and Quantitative Analysis Faculty Proceedings & Presentations

While a great deal is known about how Information and Communication Technologies are used in developing and underserved communities, there are still gaps as to how ICTs may enable development outcomes to be achieved. It appears that the majority of businesses in developing regions are micro-enterprises which employ between 1-5 people and face challenges of limited resources. This research investigates what is known about how ICTs bring about development and uses these insights to develop an information architecture adapted from the Zachman Framework that integrates the different perspectives. In this research, the key stakeholders are the micro-entrepreneurs who adopt technology …

Magnetic Hole Formation From The Perspective Of Inverse Scattering Theory, Robert L. Hamilton, D A. Peterson, S M. Libby

Faculty Publications - Department of Mathematics

The dynamics of oblique, weakly dispersive nonlinear Alfven waves in the presence of weak resistive damping are investigated numerically through an extension of the derivative nonlinear Schrodinger (DNLS) equation. It is observed numerically that the nonlinear dynamics are organized around the dynamics and allowed interactions of the underlying DNLS soliton families. There are three types of oblique Alfven solitons: the compressive two-parameter soliton and one-parameter bright soliton along with the rare factive one-parameter dark soliton. The damping of either of these compressive solitons is accompanied by the formation of one or more dark solitons. The implication of these processes is …

Singular Points Of Real Quartic And Quintic Curves, David A. Weinberg, Nicholas J. Willis

Faculty Publications - Department of Mathematics

There are thirteen types of singular points for irreducible real quartic curves and seventeen types of singular points for reducible real quartic curves. This classification is originally due to D. A. Gudkov. There are nine types of singular points for irreducible complex quartic curves and ten types of singular points for reducible complex quartic curves. There are 42 types of real singular points for irreducible real quintic curves and 49 types of real singular points for irreducible real quintic curves. The classification of real singular points for irreducible real quintic curves is originally due to Golubina and Tai. There are …

In Situ Chemical Oxidation Of Rdx-Contaminated Groundwater With Permanganate At The Nebraska Ordnance Plant, Jeffrey. A. Albano

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

Groundwater beneath the former Nebraska Ordnance Plant (NOP) is contaminated with the explosive hexahydro-1 ,3,5-trinitro-1 ,3,5-triazine (RDX). Laboratory and pilot-scale experiments were performed to quantify the efficacy of permanganate to remediate RDX-contaminated groundwater. Laboratory investigations were conducted to determine the effects of permanganate concentrations and temperature on RDX destruction kinetics as well as to determine the Permanganate Soil Oxidant Demand (PSOD) and permanganate (Mn04-) transport properties.

Batch and column experiments showed that the Todd Valley aquifer sands contained a low PSOD indicating that permanganate mass consumption by the aquifer would be minimal. PSOD experiments also showed that the PSOD of …

A Straightforward Path Routing In Wireless Ad Hoc Sensor Networks, Zhen Jiang, Junchao Ma, Wei Lou, Jie Wu

Computer Science Faculty Publications

No abstract provided.

Composing Analysis Patterns To Build Complex Models: Flight Reservation, Zhen Jiang, Eduardo B. Fernandez

Computer Science Faculty Publications

No abstract provided.

Sink-Anonymity Mobility Control In Wireless Sensor Networks, Qijun Gu, Xiao Chen, Zhen Jiang, Jie Wu

Computer Science Faculty Publications

No abstract provided.

Hole Drift Mobility Measurements On A-Si:H Using Surface And Uniformly Absorbed Illumination, Steluta A. Dinca, Eric A. Schiff, S. Guha, Baojie Yan, Jeff Yang

Physics - All Scholarship

The standard, time-of-flight method for measuring drift mobilities in semiconductors uses strongly absorbed illumination to create a sheet of photocarriers near an electrode interface. This method is problematic for solar cells deposited onto opaque substrates, and in particular cannot be used for hole photocarriers in hydrogenated amorphous silicon (a-Si:H) solar cells using stainless steel substrates. In this paper we report on the extension of the time-of-flight method that uses weakly absorbed illumination. We measured hole drift-mobilities on seven a-Si:H nip solar cells using strongly and weakly absorbed illumination incident through the n-layer. For thinner devices from two laboratories, the drift-mobilities …

Solvent-Washable Polymer Templated Synthesis Of Mesoporous Materials And Solic-Acid Nanocatalysts In One-Pot, Richard E. Mishler Ii, Ankush V. Biradar, Cole T. Duncan, Eric A. Schiff, Tewodros Asefa

Physics - All Scholarship

We report a new and simple one-pot synthetic method to produce mesoporous silica and nanoporous solid acid catalyst capable of catalyzing pinacole-pinacolone rearrangement and esterification reactions, by preparing a solvent washable phosphonated triblock copolymer template and self-assembling it in the presence of alkoxysilane.

Feasibility Of Measuring The Shapiro Time Delay Over Meter-Scale Distances, Stefan Ballmer, S. Marka, P. Shawhan

Physics - All Scholarship

The time delay of light as it passes by a massive object, first calculated by Shapiro in 1964, is a hallmark of the curvature of space-time. To date, all measurements of the Shapiro time delay have been made over solar-system distance scales. We show that the new generation of kilometer-scale laser interferometers being constructed as gravitational wave detectors, in particular Advanced LIGO, will in principle be sensitive enough to measure variations in the Shapiro time delay produced by a suitably designed rotating object placed near the laser beam. We show that such an apparatus is feasible (though not easy) to …

Is The Spacetime Metric Euclidean Rather Than Lorentzian?, Rafael D. Sorkin

Physics - All Scholarship

My answer to the question in the title is "No". In support of this point of view, we analyze some examples of saddle-point methods, especially as applied to quantum "tunneling" in nonrelativistic particle mechanics and in cosmology. Along the way we explore some of the interrelationships among different ways of thinking about path-integrals and saddle-point approximations to them.

Supersymmetric Lattices - A Brief Introduction, Simon Catterall

Physics - All Scholarship

Recently, new theoretical ideas have allowed the construction of lattice actions which are explicitly invariant under one or more supersymmetries. These theories are local and free of doublers and in the case of Yang-Mills theories also possess exact gauge invariance. In this talk these ideas are reviewed with particular emphasis being placed on ${\cal N}=4$ super Yang-Mills theory.

Carrier Drift-Mobilities And Solar Cell Models For Amorphous And Nanocrystalline Silicon, Eric A. Schiff

Physics - All Scholarship

Hole drift mobilities in hydrogenated amorphous silicon (a-Si:H) and nanocrystalline silicon (nc-Si:H) are in the range of 10-3 to 1 cm2/Vs at room-temperature. These low drift mobilities establish corresponding hole mobility limits to the power generation and useful thicknesses of the solar cells. The properties of as-deposited a-Si:H nip solar cells are quite close to their hole mobility limit, but the corresponding limit has not been examined for nc-Si:H solar cells. We explore the predictions for nc-Si:H solar cells based on parameters and values estimated from hole drift-mobility and related measurements. The indicate that the hole mobility limit for nc-Si:H …

Transit Time Measurements Of Charge Carriers In Disordered Silicons: Amorphous, Nanocrystalline, And Nanoporous, Eric A. Schiff

Physics - All Scholarship

We summarize published hole transit-time measurements for hydrogenated amorphous silicon, microcrystalline silicon, and light-emitting nanoporous silicon in terms of drift mobilities and dispersion parameters. For amorphous and microcrystalline silicon, the anomalously dispersive measurements are broadly consistent with multiple-trapping by bandtail traps with an exponential distribution of energy depths. One unexplained result has been that the trap emission prefactor frequency is about 1000 times smaller in microcrystalline silicon than in amorphous silicon. We present a model incorporating both detailed-balance effects and a previously proposed Meyer–Neldel variation of with trap-depth; the model accounts for the factor 1000. We discuss general trap distributions …

Archetype Alignment: A Two-Level Driven Semantic Matching Approach To Interoperability In The Clinical Domain, Damon Berry, Jesus Bisbal

Conference Papers

Semantic interoperability between electronic health record systems and other information systems in the health domain implies agreement about the structure and the meaning of the information that is communicated. There are still a number of similar but different EHR system approaches. Some of the newer approaches adopt the two-layer model approach where a generic reference model is constrained by archetypes into valid clinical concepts which can be exchanged. The meaning of the concepts that are represented by an archetype can be conveyed by embedding codes from a commonly recognised terminology at appropriate points in the archetype. However, as the number …

Research Design And Statistical Applications, Grayson Holmbeck, Kathy Zebracki, Katie Mcgoron

Psychology: Faculty Publications and Other Works

What is the role of research in the field of pediatric psychology? To answer this question, it is useful to imagine what clinical practice would be like if we had no research foundation for our work. Without such a foundation, practitioners would have no basis for suggesting specific interventions or understanding why some interventions are successful and why others fail. Similarly, without a research foundation, assessments conducted with children would be based on unstandardized assessment methods, and no normative data would be available. Clearly, most of us would agree that scientific research is the foundation of pediatric psychology, including all …

Water Current, Volume 41, No. 1, Winter 2009

Water Current Newsletter

When Water Meets Money Topic of Sixth Annual Conference, April 29, 30
Meet the Faculty: Chad E. Brassil, Ph.D., Zhenghong Tan, Ph.D.
Database Connects Public to University of Nebraska Research
From the Director: Where Were You on the First Earth Day?
Arctic Lakes May Hold Clues to Understanding Climate Change
June Tour Examines California's Bay-Delta
Fall Symposium: Platte River Basin Science and Resource Management October 14 and 15 in Kearney
UNL Faculty Provide Updates to the Water Resources Advisory Panel
Through the Looking Glass: Multifaceted Fate of EmergingContaminants in Nebraska Waterways
Water Seminar Lectures Continue Through April
Get Your Water …