Digital Commons Network^™

Life In A Temperate Polar Sea: A Unique Taphonomic Window On The Structure Of A Late Cretaceous Arctic Marine Ecosystem, Karen Chin, John Bloch, Arthur Sweet, Justin Tweet, Jaelyn Eberle, Stephen Cumbaa, Jakub Witowski, David M. Harwood

Department of Earth and Atmospheric Sciences: Faculty Publications

As the earth faces a warming climate, the rock record reminds us that comparable climatic scenarios have occurred before. In the Late Cretaceous, Arctic marine organisms were not subject to frigid temperatures but still contended with seasonal extremes in photoperiod. Here, we describe an unusual fossil assemblage from Devon Island, Arctic Canada, that offers a snapshot of a ca 75 _MYR ago marine paleoecosystem adapted to such conditions. Thick siliceous biogenic sediments and glaucony sands reveal remarkably persistent high primary productivity along a high-latitude Late Cretaceous coastline. Abundant fossil feces demonstrate that this planktonic bounty supported benthic invertebrates and large, …

Elevated Primary Productivity Of Calcareous Nannoplankton Associated With Ocean Anxoic Event 1b During The Aptian/Albian Transition (Early Cretaceous), Emily L. Browning, David K. Watkins

Department of Earth and Atmospheric Sciences: Faculty Publications

Previous isotopic investigations of Aptian/Albian oceanic anoxic event (OAE) 1b from the western North Atlantic (Blake Nose) posited that increased sea surface temperatures and decreased salinity led to stratification of the upper water column, resulting in lowered dissolved oxygen and enhanced organic matter preservation. We examined calcareous nannofossils from the same site in the western North Atlantic (Blake Nose) to evaluate changes in surface water conditions prior to, during, and after the Aptian/Albian OAE1b. The results of our analysis conflict somewhat with the previous interpretation that OAE1b at Blake Nose was linked to water column stratification. The signal from calcareous …

Seismic Facies And Stratigraphy Of The Cenozoic Succession In Mcmurdo Sound, Antarctica: Implications For Tectonic, Climatic And Glacial History, Christopher R. Fielding, Joanne Whittaker, Stuart A. Henrys, Terry J. Wilson, Timothy R. Naish

Department of Earth and Atmospheric Sciences: Faculty Publications

Integration of data from fully cored stratigraphic holes with an extensive grid of seismic reflection lines in McMurdo Sound, Antarctica, has allowed the formulation of a new model for the evolution of the Cenozoic Victoria Land Basin of the West Antarctic Rift. The Early Rift phase (Eocene to Early Oligocene) is recorded by wedges of strata confined by early extensional faults, and which contain seismic facies consistent with drainage via coarse-grained fans and deltas into discrete, actively subsiding grabens and half-grabens. The Main Rift phase (Early Oligocene to Early Miocene) is represented by a lens of strata that thickens symmetrically …

Chloride And The Environmental Isotopes As The Indicators Of The Groundwater Recharge In The Gobi Desert, Northwest China, J. Z. Ma, Z. Ding, John B. Gates, Y. Su

Department of Earth and Atmospheric Sciences: Faculty Publications

The long term recharge in Gobi Desert from Hexi Corridor to Inner Mongolia Plateau was estimated to Be 1 mm year^-1 by using the chloride mass balance method from one unsaturated zone profile, which shows that no effective modern recharge is taking place. A good rainfall database from Zhangye provides definition of the stable isotopic composition of modern rainfall. The signature of groundwater from the late Pleistocene differs markedly from that of the Holocene, shown clearly by the compositions of -10.5‰ δ¹⁸O as compared with values of -7‰ at the present day. It is apparent that the …

Seismic Facies And Stratigraphy Of The Cenozoic Succession In Mcmurdo Sound, Antarctica: Implications For Tectonic, Climatic And Glacial History, Christopher R. Fielding, J. Whittaker, Stuart A. Henrys, T. J. Wilson, T. R. Naish

Department of Earth and Atmospheric Sciences: Faculty Publications

A new stratigraphic model is presented for the evolution of the Cenozoic Victoria Land Basin of the West Antarctic Rift, based on integration of seismic reflection and drilling data. The Early Rift phase (?latest Eocene to Early Oligocene) comprises wedges of strata confined by early extensional faults, and which contain seismic facies consistent with drainage via coarse-grained fans and deltas into discrete, actively subsiding grabens and half-grabens. The Main Rift phase (Early Oligocene to Early Miocene) comprises a lens of strata that thickens symmetrically from the basin margins into a central depocenter, and in which stratal events pass continuously over …

An Observational Analysis And Evaluation Of Land Surface Model Accuracy In The Nebraska Sand Hills, David B. Radell, Clinton M. Rowe

Department of Earth and Atmospheric Sciences: Faculty Publications

In this study, the influence of subsurface water on the energy budget components of three locations with heterogeneous land surfaces in the Nebraska Sand Hills are examined through observations and use of the Noah land surface model (LSM). Observations of the four primary components of the surface energy budget are compared for a wet interdunal meadow valley, a dry interdunal valley, and a dunal upland location. With similar atmospheric forcing at each site, it was determined that differences in the partitioning of the mean diurnal net radiation (R_net) existed among the three locations due to the influence …

Improved Algorithm For Modis Satellite Retrievals Of Aerosol Optical Depths Over Western North America, Easan Drury, Daniel J. Jacob, Jun Wang, Robert J.D. Spurr, Kelly Chance

Department of Earth and Atmospheric Sciences: Faculty Publications

Quantitative evaluation of chemical transport models (CTMs) with aerosol optical depth (AOD) products retrieved from satellite backscattered reflectances can be compromised by inconsistent assumptions of aerosol optical properties and errors in surface reflectance estimates. We present an improved AOD retrieval algorithm for the MODIS satellite instrument using locally derived surface reflectances and CTM aerosol optical properties for the 0.47, 0.65, and 2.13 μm MODIS channels. Assuming negligible atmospheric reflectance at 2.13 μm in cloud-free conditions, we derive 0.65/2.13 surface reflectance ratios at 1° X 1.25° horizontal resolution for the continental United States in summer 2004 from the subset of top-of-atmosphere …

The Optimal Bulk Wind Differential Depth And The Utility Of The Upper-Tropospheric Storm-Relative Flow For Forecasting Supercells, Adam L. Houston, Richard L. Thompson, Roger Edwards

Department of Earth and Atmospheric Sciences: Faculty Publications

An analysis of 4 yr of Rapid Update Cycle-2 (RUC-2) derived soundings in proximity to radar-observed supercells and nonsupercells is conducted in an effort to answer two questions: 1) over what depth is the fixed-layer bulk wind differential (BWD; the vector difference between the wind velocity at a given level and the wind velocity at the surface) the best discriminator between supercell and nonsupercell environments and 2) does the upper-tropospheric storm-relative flow (UTSRF) discriminate between the environments of supercells and nonsupercells? Previous climatologies of sounding-based supercell forecast parameters have documented the ability of the 0–6-km BWD in delineating supercell from …

Ex-Situ And In-Situ Selenization Of Copper-Indium And Copper-Boron Thin Films, Rodney J. Soukup, Natale J. Ianno, Chad Kamler, Martin Diaz, Shuchi Sharma, James Huguenin-Love, Jiri Olejnicek

Department of Electrical and Computer Engineering: Faculty Publications

It has recently been established that the ideal bandgap for terrestrial photovoltaics is 1.37 eV and the bandgap for CulnSe2 is only around 1.04 eV. Thus, a larger bandgap is needed. However, neither the substitution of Ga nor of AI has made a high efficiency solar cell absorber with a band gap of 1.37 eV possible. B, an even smaller atom, should require less atomic substitution than either Ga or AI to achieve a wider bandgap. In order to fabricate a thin film of Culn_xB_1-xSe₂ (CIBS), Cu, In and B were deposited from a variety …

Grid Connection Requirements And Solutions For Dfig Wind Turbines, Wei Qiao, Ronald G. Harley

Department of Electrical and Computer Engineering: Faculty Publications

As the number and size of windfarms continue to grow,many countries have established or are developing a set of specific requirements (i.e., grid codes) for operation and grid connection of windfarms. The objective of these grid codes is to ensure that wind farms do not adversely affect the power system operation with respect to security of supply, reliability and power quality. This paper reviews major grid code requirements for wind farms, and investigates various technologies developed by and solutions proposed by researchers and wind turbine manufactures in order to meet these requirements. In addition, some ofthe authors' work on these …

Reliability-Based Stand-Alone Photovoltaic System Sizing Design- A Case Study, Haifeng Ge, Liqin Ni, Sohrab Asgarpoor

Department of Electrical and Computer Engineering: Faculty Publications

This paper introduces a method for designing a standalone photovoltaic system to improve the load point reliability, extend the operation life, and minimize the design cost. This approach examines the impacts of solar panel sizes, tilt angles and battery volumes toward load point reliability, as well as the expected system life, by using real insolation data in a given location and random load burdens. The reliability evaluation incorporating solar insolation variations and load point uncertainty is performed. Life evaluation of battery is included in this paper with consideration of the battery State of Charge (SoC) history. The Economical analysis to …

A Quantitative Study Of Mobility Impact For Real- Time Services On A Wi-Fi Multi-Hop Network, Ting Zhou, Hamid Sharif, Michael Hempel, Puttipong Mahasukhon, Wei Wang, Song Ci

Department of Electrical and Computer Engineering: Faculty Publications

In this paper, we analyze the performance of mobile real time services in a large-scale IEEE 802.11 multi-hop network. We present our field measurements with discussion of performance bottlenecks for VoIP services under mobile scenarios. We utilized our test bed which is located in Nebraska and supported by the University of Nebraska-Lincoln (UNL), US Federal Railroads Administrations (FRA), and major US railroad companies. Our UNL-FRA test bed consists of 8 outdoor access point towers, which are deployed along 3.5 mile of BNSF railroad. Passive measurement approaches are taken to ensure the integrity of collected data and multi-layer stream based packet …

Full-Wave Finite-Difference Time-Domain Simulation Of Electromagnetic Cloaking Structures, Yan Zhao, Christos Argyropoulos, Yang Hao

Department of Electrical and Computer Engineering: Faculty Publications

This paper proposes a radial dependent dispersive finitedifference time-domain method for the modeling of electromagnetic cloaking structures. The permittivity and permeability of the cloak are mapped to the Drude dispersion model and taken into account in dispersive FDTD simulations. Numerical simulations demonstrate that under ideal conditions, objects placed inside the cloak are ‘invisible’ to external electromagnetic fields. However for the simplified cloak based on linear transformations, the back scattering has a similar level to the case of a PEC cylinder without any cloak, rendering the object still being ‘visible’. It is also demonstrated numerically that the simplified cloak based on …

Gene Expression Analysis Of Embryonic Stem Cells Expressing Ve-Cadherin (Cd144) During Endothelial Differentiation, Vesna Nikolova-Krstevski, Manoj Bhasin, Hasan H. Otu, Towia A. Libermann, Peter Oettgen

Department of Electrical and Computer Engineering: Faculty Publications

Background: Endothelial differentiation occurs during normal vascular development in the developing embryo. This process is recapitulated in the adult when endothelial progenitor cells are generated in the bone marrow and can contribute to vascular repair or angiogenesis at sites of vascular injury or ischemia. The molecular mechanisms of endothelial differentiation remain incompletely understood. Novel approaches are needed to identify the factors that regulate endothelial differentiation.

Methods: Mouse embryonic stem (ES) cells were used to further define the molecular mechanisms of endothelial differentiation. By flow cytometry a population of VEGF-R2 positive cells was identified as early as 2.5 days after differentiation …

Aspects Of Producing, Directing, Conditioning, Impinging And Detecting Spectroscopic Electromagnetic Radiation From Small Spots On Samples, Martin M. Liphardt, Ping He, Blaine D. Johs, Galen L. Pfeiffers, James D. Welch, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

Sytems and mehtods for providing and enhancing electromagnetic radiation beam radail energy homogeneity and intensity vs. wavelength content, for reliably directing electromagnetic radiation emitted by a source thereof in a common direction, for achromatically reducing spot size on a sample (eg. liquid cavity containing lenses and low aberration 1:1 imaging systems modified to perform as spatial filters), and for directing directing different wavelengths into different detectors, in ellipsometer, polarizer or the like systems.

System And Method Ofselectively Monitoring Sample Front And Backside Reflections In Ellipsometer And The Like Systems, James D. Welch, John A. Woollam, Martin M Liphardt

Department of Electrical and Computer Engineering: Faculty Publications

A spectrophotometer, reflectometer, ellipsometer polarimeter or the like system having a detector means for independently intercepting electromagnetic radiation reflected from a sample frontside or backside, and methodology for pursuing less correlated determination of refractive index and thickness values.

Ex–Dividend Day Price And Volume: The Case Of 2003 Dividend Tax Cut, Yi Zhang, Kathleen A. Farrell, Todd A. Brown

Department of Finance: Faculty Publications

We examine the impact of the 2003 dividend tax cut, which removes the differential taxation between dividends and capital gains for individual investors, on the ex–dividend day price and trading volume. We find the ex–dividend day price and volume are affected by taxes, risk, and transaction costs. The ex–dividend day price drop ratio (excess return) increases (decreases) and dividend clienteles weaken after the tax cut. Ex–dividend day abnormal volume among high dividend yield stocks decreases after the tax cut consistent with a diminished motivation for tax–induced trading. Our results suggest that individual investors have a measurable effect on the ex–dividend …

How Do Firms Adjust Director Compensation?, Kathleen A. Farrell, Geoffrey C. Friesen, Philip L. Hersch

Department of Finance: Faculty Publications

This paper examines outside director compensation for a sample of 237 Fortune 500 firms over the 1998-2004 period. We document a trend towards fixed-value equity compensation and away from cash only and fixed-number equity compensation. Adjustments to director compensation are consistent with firms targeting a market level of compensation, and firms that deviate from their market wage symmetrically adjust compensation back toward the market level. We also document the relation between changes in compensation and changes in equity values, and find that upward adjustments begin sooner than downward adjustments. When equity values rise, we find virtually no immediate offset to …

Non-Optimal Receiver For Space Time Spreading Across A Time Hopping Over Ultra Wideband Ppm, Peter Vial, Beata Wysocki, Tadeusz Wysocki

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

A novel non-optimal chip based technique is proposed to use two antennas to transmit data across a Direct Sequence Time Hopping Ultra Wideband dual antenna wireless communication system to a single receiver. The spread data is sent over the independent channels using the Space Time Spreading technique to encode the chips which are sent on each antenna simultaneously. A hard decision is made at each chip of the spreading code received based on the known Channel State Information which Pulse Position Modulated signal was received from each antenna. The paper shows that by adapting the Space Time Spreading technique to …

Performance Analysis Of Multi-Hop Ieee 802.11 Dcf Backhaul Networks, Puttipong Mahasukhon, Hamid Sharif, Michael Hempel, Ting Zhou, Wei Wang, Tadeusz Wysocki

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

Because of the wide deployment of 802.11 equipments in the past decade, current applications are not limited anymore to only single Access Points (AP) deployments for indoor usage, but have been extended to multi-hop networks to fulfill the need of high speed connectivity in mobile environments, where the analysis of multi-hop networks is extremely complicated. The behavior of an AP is dependent not only on its neighbors’ behavior, but also on the behavior of other hidden nodes. In this paper, we provide an accurate and verified multi-hop wireless backhaul analysis for performance of IEEE 802.11 DCF in terms of the …

Cooperative Communication In Space-Time-Frequency Coded Mb-Ofdm Uwb, L. C. Tran, A. Mertins, Tadeusz Wysocki

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

Though cooperative communication has been intensively examined for general wireless systems, such as mobile and ad-hoc networks, it has been almost unexplored in the case of Space-Time-Frequency Coded Multi-band OFDM Ultra-Wideband (STFC MB-OFDM UWB). This paper proposes a framework of cooperative communication in such systems where nodes are equipped with only one antenna. Simulation results show that cooperative communication might, in some cases, provide better error performance than non-cooperative communication without any additional transmission power.

Sample Editions Of The Oxford Hebrew Bible: Deuteronomy 32:1-9, 1 Kings 11:1-8, And Jeremiah 27:1-10 (34 G), Sidnie White Crawford, Jan Joosten, Eugene Ulrich

Department of Classics and Religious Studies: Faculty Publications

The following sample editions illustrate the theory and method of the Oxford Hebrew Bible. The Deuteronomy sample, edited by Sidnie White Crawford, concerns a text with one ancient edition, while the Kings sample, edited by Jan Joosten, and the Jeremiah sample, edited by Eugene Ulrich, concern texts with two ancient editions. The arguments that justify the editorial decisions are presented in the apparatuses and text-critical commentaries. (The detailed introductory chapters are not included.) The critical texts, following the conventions discussed in the previous article, contain the following sigla: a superlinear circlet to indicate an entry in the apparatus where the …

A 20-Year Plan For Hunter/Angler Recruitment, Development And Retention In Nebraska, Mark Pinkerton, Ron Stave, Mick Jensen, James Ziebarth, Jerrod Burke, Lynn Berggren, George Hall, Kent Forney

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

Hunting and fishing are important parts of Nebraska’s rich heritage. These time-honored outdoor pursuits are important to overall lifestyle, well-being and natural resources of the citizens of Nebraska. The North American Model for Conservation was based primarily on the activism from our nation’s hunters and anglers. Their role helped develop and instill the seven basic premises of the model: Wildlife is to be held in public trust, there should be an elimination of market hunting, wildlife should be allocated by law, there should be hunting/angling opportunities for all citizens, wildlife should only be killed for legitimate reasons, wildlife should be …

Later Christian Hebraists, Stephen G. Burnett

Department of Classics and Religious Studies: Faculty Publications

Christian Hebrew scholarship as an academic discipline was born during the sixteenth century. The founding of chairs of Hebrew language at European universities, the emergence of Hebrew presses to supply the needs of Christian customers, the willingness of some Jewish experts to instruct Christian pupils, and above all the humanist motivation for a return to the sources of the Christian faith together made Hebrew education possible for greater numbers of Christian scholars than ever before. The majority of these scholars had only a smattering of Hebrew, and those such as Conrad Pellican, and Paul Fagius who could read and understand …

Remembering And Forgetting Black Power In Mississippi Burning, Kristen Hoerl

Department of Communication Studies: Faculty Publications

Although critics are correct to point out that Mississippi Burning did not faithfully depict historical events surrounding the real-life disappearances of [civil rights activists] Chaney, Schwerner, and Goodman, I argue that these criticisms overlook some of the ways in which the film advances the cause of racial justice. On a formal level, Mississippi Burning evokes the struggles experienced by members of the Black Power movement, a social movement that emerged on the heels of civil rights. Looking at the film in the context of this movement, I argue that Mississippi Burning is a homology for the Black Power movement. Barry …

Network Coding For Wdm All-Optical Multicast, Eric D. Manley, Jitender S. Deogun, Lisong Xu, Dennis R. Alexander

School of Computing: Technical Reports

Network coding has become a useful means for achieving efficient multicast, and the optical community has started to examine its application to optical networks. However, a number of challenges, including limited processing capability and coarse bandwidth granularity, need to be overcome before network coding can be effectively used in optical networks. In this paper, we address some of these problems. We consider the problem of finding efficient routes to use with coding, and we study the effectiveness of using network coding for optical-layer dedicated protection of multicast traffic. We also propose architectures for all-optical circuits capable of performing the processing …

Comparison Of Amylose Determination Methods And The Development Of A Dual Wavelength Iodine Binding Technique, Thianming Zhu, David S. Jackson, Randy L. Wehling, Bhima Geera

Department of Food Science and Technology: Faculty Publications

It has long been recognized that limitations exist in the analytical methodology for amylose determination. This study was conducted to evaluate various amylose determination methods. Purified amylose and amylopectin fractions were obtained from com, rice, wheat, and potato and then mixed in proportion to make 10, 20, 30, 50, and 80% amylose content starch samples for each source. These samples, considered amylose standards, were analyzed using differential scanning calorimetry (DSC), high-performance size-exclusion chromatography (HPSEC), and iodine binding procedures to generate standard curves for each of the methods. A single DSC standard equation for cereal starches was developed. The standard curve …

Genotypic Characterization And Prevalence Of Virulence Factors Among Canadian Escherichia Coli O157:H7 Strains, Kim Ziebell, Marina Steele, Yongxiang Zhang, Andrew K. Benson, Eduardo N. Taboada, Chad Laing, Scott Mcewen, Bruce Ciebin, Roger Johnson, Victor Gannon

Department of Food Science and Technology: Faculty Publications

In this study, the association between genotypic and selected phenotypic characteristics was examined in a collection of Canadian Escherichia coli O157:H7 strains isolated from humans and cattle in the provinces of Alberta, Ontario, Saskatchewan, and Quebec. In a subset of 69 strains selected on the basis of specific phage types (PTs), a strong correlation between the lineage-specific polymorphism assay (LSPA6) genotype and PT was observed with all strains of PTs 4, 14, 21, 31, 33, and 87 belonging to the LSPA6 lineage I (LSPA6-LI) genotype, while those of PTs 23, 45, 67, and 74 belonged to LSPA6 lineage II (LSPA6-LII) …

Short-Term Memory, Working Memory, And Executive Functioning In Preschoolers: Longitudinal Predictors Of Mathematical Achievement At Age 7 Years, Rebecca Bull, Kimberly Andrews Espy, Sandra A. Wiebe

Department of Educational Psychology: Faculty Publications

This study examined whether measures of short-term memory, working memory, and executive functioning in preschool children predict later proficiency in academic achievement at 7 years of age (third year of primary school). Children were tested in preschool (M age = 4 years, 6 months) on a battery of cognitive measures, and mathematics and reading outcomes (from standardized, norm-referenced school-based assessments) were taken on entry to primary school, and at the end of the first and third year of primary school. Growth curve analyses examined predictors of math and reading achievement across the duration of the study and revealed that …

Contributions Of Children’S Temperament To Teachers’ Judgments Of Social Competence From Kindergarten Through Second Grade, Kathleen Moritz Rudasill, Timothy R. Konold

Department of Educational Psychology: Faculty Publications

Research Findings: Children’s social competence has been linked to successful transition to formal school. The purpose of this study was to examine the contributions of children’s temperament to teachers’ ratings of their social competence from kindergarten through 2nd grade. Children (N = 1,364) from the National Institute of Child Health and Human Development Early Child Care Research Network participated in this study. Mothers rated children’s shyness, attentional focusing, and inhibitory control with the Children’s Behavior Questionnaire at 4½ years, and teachers rated children’s social competence with three subscales (cooperation, assertion, and self-control) of the Social Skills Rating System at …