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2017

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Articles 10981 - 11010 of 11069

Full-Text Articles in Physical Sciences and Mathematics

The Conservation Status Of Marine Bony Shorefishes Of The Greater Caribbean, Kent E. Carptenter, Christi Linardich, Gina Ralph, N. Cox, D. R. Robertson, H. Harwell, A. Acero P., W. Anderson Jr., F. Barthelat, J. -L. Bouchereau, J. J. Brown, J. Buchanan, D. Buddo, B. Collette, M. Comeros-Raynal, M. Craig, M. Curtis, T. Defex, J. Dooley, W. Driggers Iii, C. Elfes Livsey, T. Fraser, R. Gilmore Jr., L. Grijalba Bendeck, A. Hines, R. Kishore, K. Lindeman, J. -P. Maréchal, J. Mceachran, R. Mcmanus, J. Moore, T. Munroe, H. Oxenford, F. Pezold, F. Pina Amargós, A. Polanco Fernandez, B. Polidoro, C. Pollock, R. Robins, B. Russell, C. Sayer, S. Williams Jan 2017

The Conservation Status Of Marine Bony Shorefishes Of The Greater Caribbean, Kent E. Carptenter, Christi Linardich, Gina Ralph, N. Cox, D. R. Robertson, H. Harwell, A. Acero P., W. Anderson Jr., F. Barthelat, J. -L. Bouchereau, J. J. Brown, J. Buchanan, D. Buddo, B. Collette, M. Comeros-Raynal, M. Craig, M. Curtis, T. Defex, J. Dooley, W. Driggers Iii, C. Elfes Livsey, T. Fraser, R. Gilmore Jr., L. Grijalba Bendeck, A. Hines, R. Kishore, K. Lindeman, J. -P. Maréchal, J. Mceachran, R. Mcmanus, J. Moore, T. Munroe, H. Oxenford, F. Pezold, F. Pina Amargós, A. Polanco Fernandez, B. Polidoro, C. Pollock, R. Robins, B. Russell, C. Sayer, S. Williams

Biological Sciences Faculty Publications

The greater Caribbean biogeographic region covered in this report (representing 38 countries and territories) encompasses an outstanding marine bony shorefish richness of approximately 1,360 species, with many (53%) being endemic. This report provides an overview of the conservation status of greater Caribbean shorefishes, with detailed information available through the IUCN Red List, and gives recommendations.

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Informing Marine Protected Area Designation And Management For Nesting Olive Ridley Sea Turtles Using Satellite Tracking, Tiffany M. Dawson, Angela Formia, Pierre D. Agamboué, Georges M. Asseko, François Boussamba, Floriane Cardiec, Emmanuel Chartrain, Philip D. Doherty, J. Michael Fay, Brendan J. Godley, Francis Lambert, Brice D. Koumba Mabert, Jean C. Manfoumbi, Kristian Metcalfe, Gianna Minton, Ivan Ndanga, Jacob Nzegoue, Carmen K. Kouerey Oliwina, Philippe Du Plessis, Guy-Philippe Sounguet, Dominic Tilley, Matthew J. Witt, Sara M. Maxwell Jan 2017

Informing Marine Protected Area Designation And Management For Nesting Olive Ridley Sea Turtles Using Satellite Tracking, Tiffany M. Dawson, Angela Formia, Pierre D. Agamboué, Georges M. Asseko, François Boussamba, Floriane Cardiec, Emmanuel Chartrain, Philip D. Doherty, J. Michael Fay, Brendan J. Godley, Francis Lambert, Brice D. Koumba Mabert, Jean C. Manfoumbi, Kristian Metcalfe, Gianna Minton, Ivan Ndanga, Jacob Nzegoue, Carmen K. Kouerey Oliwina, Philippe Du Plessis, Guy-Philippe Sounguet, Dominic Tilley, Matthew J. Witt, Sara M. Maxwell

Biological Sciences Faculty Publications

Understanding the horizontal and vertical habitat of olive ridley sea turtles (Lepidochelys olivacea), a threatened species, is critical for determining regions for protection and relevant gear modifications that may effectively reduce bycatch, the largest threat to this species. Satellite transmitters were used to determine the movement and dive behavior of 21 female olive ridley turtles tagged in Pongara National Park, Gabon during the 2012, 2013, and 2015 nesting seasons. A switching state-space model was used to filter the tracking data and categorize the internesting and post-nesting movements. Gridded utilization distribution (UD) home range analysis of tracking data revealed …

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So What Are You Going To Do With That? The Promises And Pitfalls Of Massive Data Sets, Sigrid Anderson Cordell, Melissa Gomis Jan 2017

So What Are You Going To Do With That? The Promises And Pitfalls Of Massive Data Sets, Sigrid Anderson Cordell, Melissa Gomis

University of Nebraska-Lincoln Libraries: Faculty Publications

This article takes as its case study the challenge of data sets for text mining, sources that offer tremendous promise for digital humanities (DH) methodology but present specific challenges for humanities scholars. These text sets raise a range of issues: What skills do you train humanists to have? What is the library’s role in enabling and supporting use of those materials? How do you allocate staff? Who oversees sustainability and data management? By addressing these questions through a specific use case scenario, this article shows how these questions are central to mapping out future directions for a range of library …

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Quantifying Ephemeral Gully Erosion With Photogrammetry Surveying, C. B. Weerasekara, A. Y. Shechukov Jan 2017

Quantifying Ephemeral Gully Erosion With Photogrammetry Surveying, C. B. Weerasekara, A. Y. Shechukov

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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Smart Underground Antenna Arrays: A Soil Moisture Adaptive Beamforming Approach, Abdul Salam, Mehmet C. Vuran Jan 2017

Smart Underground Antenna Arrays: A Soil Moisture Adaptive Beamforming Approach, Abdul Salam, Mehmet C. Vuran

School of Computing: Technical Reports

In this paper, a novel framework for underground beamforming using adaptive antenna arrays is presented. Based on the analysis of propagation in wireless underground channel, a theoretical model is developed which uses soil moisture information and feedback mechanism to improve performance wireless underground communications. Array element in soil has been analyzed empirically and impacts of soil type and soil moisture on return loss and resonant frequency are investigated. Beam patterns are investigated to communicate with both underground and above ground devices. Depending on the incident angle, refraction from soil-air interface has the adverse effects in the UG communications. It is …

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Wireless Underground Channel Diversity Reception With Multiple Antennas For Internet Of Underground Things, Abdul Salam, Mehmet C. Vuran Jan 2017

Wireless Underground Channel Diversity Reception With Multiple Antennas For Internet Of Underground Things, Abdul Salam, Mehmet C. Vuran

School of Computing: Conference and Workshop Papers

Internet of underground things (IOUT) is an emerging paradigm which consists of sensors and communication devices, partly or completely buried underground for real-time soil sensing and monitoring. In this paper, the performance of different modulation schemes in IOUT communications is studied through simulations and experiments. The spatial modularity of direct, lateral, and reflected components of the UG channel is exploited by using multiple antennas. First, it has been shown that bit error rates of $10^{-3}$ can be achieved with normalized delay spreads ($\tau_d$) lower than $0.05$. Evaluations are conducted through the first software-defined radio-based field experiments for UG channel. Moreover, …

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Towards Internet Of Underground Things In Smart Lighting: A Statistical Model Of Wireless Underground Channel, Abdul Salam, Mehmet C. Vuran, Suat Irmak Jan 2017

Towards Internet Of Underground Things In Smart Lighting: A Statistical Model Of Wireless Underground Channel, Abdul Salam, Mehmet C. Vuran, Suat Irmak

School of Computing: Conference and Workshop Papers

The Internet of Underground Things (IOUT) has many applications in the area of smart lighting. IOUT enables communications in smart lighting through underground (UG) and aboveground (AG) communication channels. In IOUT communications, an in-depth analysis of the wireless underground channel is important to design smart lighting solutions. In this paper, based on the empirical and the statistical analysis, a statistical channel model for the UG channel has been developed. The parameters for the statistical tapped-delay-line model are extracted from the measured power delay profiles (PDP). The PDP of the UG channel is represented by the exponential decay of the lateral, …

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Smart Underground Antenna Arrays: A Soil Moisture Adaptive Beamforming Approach, Abdul Salam, Mehmet C. Vuran Jan 2017

Smart Underground Antenna Arrays: A Soil Moisture Adaptive Beamforming Approach, Abdul Salam, Mehmet C. Vuran

School of Computing: Conference and Workshop Papers

Current wireless underground (UG) communication techniques are limited by their achievable distance. In this paper, a novel framework for underground beamforming using adaptive antenna arrays is presented to extend communication distances for practical applications. Based on the analysis of propagation in wireless underground channel, a theoretical model is developed which uses soil moisture information to improve wireless underground communications performance. Array element in soil is analyzed empirically and impacts of soil type and soil moisture on return loss (RL) and resonant frequency are investigated. Accordingly, beam patterns are analyzed to communicate with underground and above ground devices. Depending on the …

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Biosimp: Using Software Testing Techniques For Sampling And Inference In Biological Organisms, Mikaela Cashman, Jennie L. Catlett, Myra B. Cohen, Nicole R. Buan, Zahmeeth Sakkaff, Massimiliano Pierobon, Christine A. Kelley Jan 2017

Biosimp: Using Software Testing Techniques For Sampling And Inference In Biological Organisms, Mikaela Cashman, Jennie L. Catlett, Myra B. Cohen, Nicole R. Buan, Zahmeeth Sakkaff, Massimiliano Pierobon, Christine A. Kelley

School of Computing: Conference and Workshop Papers

Years of research in software engineering have given us novel ways to reason about, test, and predict the behavior of complex software systems that contain hundreds of thousands of lines of code. Many of these techniques have been inspired by nature such as genetic algorithms, swarm intelligence, and ant colony optimization. In this paper we reverse the direction and present BioSIMP, a process that models and predicts the behavior of biological organisms to aid in the emerging field of systems biology. It utilizes techniques from testing and modeling of highly-configurable software systems. Using both experimental and simulation data we show …

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Tropospheric Emissions: Monitoring Of Pollution (Tempo), P. Zoogman, X. Liu, R. M. Suleiman, W. F. Pennington, D. E. Flittner, J. A. Al-Saadi, B. B. Hinton, D. K. Nicks, M. J. Newchurch, J. L. Carr, S. J. Janz, M. R. Andraschko, A. Arola, B. D. Baker, B. P. Canova, C. Chan Miller, R. C. Cohen, J. E. Davis, M. E. Dussault, D. P. Edwards, J. Fishman, A. Ghulam, G. Gonzalez Abad, M. Grutter, J. R. Herman, J. Houck, D. J. Jacob, J. Joiner, B. J. Kerridge, J. Kim, N. A. Krotkov, L. Lamsal, C. Li, A. Lindfors, R. V. Martin, C. T. Mcelroy, C. Mclinden, V. Natraj, D. O. Neil, C. R. Nowlan, E. J. O'Sullivan, P. I. Palmer, R. B. Pierce, M. R. Pippin, A. Saiz-Lopez, R. J. D. Spurr, J. J. Szykman, O. Torres, J. P. Veefkind, B. Veihelmann, H. Wang, J. Wang Jan 2017

Tropospheric Emissions: Monitoring Of Pollution (Tempo), P. Zoogman, X. Liu, R. M. Suleiman, W. F. Pennington, D. E. Flittner, J. A. Al-Saadi, B. B. Hinton, D. K. Nicks, M. J. Newchurch, J. L. Carr, S. J. Janz, M. R. Andraschko, A. Arola, B. D. Baker, B. P. Canova, C. Chan Miller, R. C. Cohen, J. E. Davis, M. E. Dussault, D. P. Edwards, J. Fishman, A. Ghulam, G. Gonzalez Abad, M. Grutter, J. R. Herman, J. Houck, D. J. Jacob, J. Joiner, B. J. Kerridge, J. Kim, N. A. Krotkov, L. Lamsal, C. Li, A. Lindfors, R. V. Martin, C. T. Mcelroy, C. Mclinden, V. Natraj, D. O. Neil, C. R. Nowlan, E. J. O'Sullivan, P. I. Palmer, R. B. Pierce, M. R. Pippin, A. Saiz-Lopez, R. J. D. Spurr, J. J. Szykman, O. Torres, J. P. Veefkind, B. Veihelmann, H. Wang, J. Wang

Department of Earth and Atmospheric Sciences: Faculty Publications

TEMPO was selected in 2012 by NASA as the first Earth Venture Instrument, for launch between 2018 and 2021. It will measure atmospheric pollution for greater North America from space using ultraviolet and visible spectroscopy. TEMPO observes from Mexico City, Cuba, and the Bahamas to the Canadian oil sands, and from the Atlantic to the Pacific, hourly and at high spatial resolution (~2.1kmN/S x 4.4 kmE/W at 36.5°N, 100°W). TEMPO provides a tropospheric measurement suite that includes the key elements of tropospheric air pollution chemistry, as well as contributing to carbon cycle knowledge. Measurements are made hourly from geostationary (GEO) …

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Fire And Smoke Remote Sensing And Modeling Uncertainties: Case Studies In Northern Sub‐Saharan Africa, Charles Ichoku, Luke T. Ellison, Yun Yue, Jun Wang, Johannes W. Kaiser Jan 2017

Fire And Smoke Remote Sensing And Modeling Uncertainties: Case Studies In Northern Sub‐Saharan Africa, Charles Ichoku, Luke T. Ellison, Yun Yue, Jun Wang, Johannes W. Kaiser

Department of Earth and Atmospheric Sciences: Faculty Publications

Significant uncertainties are incurred in deriving various quantities related to biomass burning from satellite measurements at different scales, and, in general, the coarser the resolution of observation the larger the uncertainty. WRF‐Chem model simulations of smoke over the northern sub‐Saharan African (NSSA) region for January–February 2010, using fire energetics and emissions research version 1.0 (FEERv1) aerosol emissions derived from MODIS measurements of fire radiative power (FRP) and aerosol optical depth (AOD), resulted in a severe model underestimation of AOD compared with satellite retrievals. Such uncertainties are attributable to three major factors: limitations in the spatial and temporal resolutions of the …

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Intercomparison Of Modis And Viirs Fire Products In Khanty-Mansiysk Russia: Implications For Characterizing Gas Flaring From Space, Ambrish Sharma, Jun Wang, Elizabeth M. Lennartson Jan 2017

Intercomparison Of Modis And Viirs Fire Products In Khanty-Mansiysk Russia: Implications For Characterizing Gas Flaring From Space, Ambrish Sharma, Jun Wang, Elizabeth M. Lennartson

Department of Earth and Atmospheric Sciences: Faculty Publications

Gas flaring is commonly used by industrial plants for processing oil and natural gases in the atmosphere, and hence is an important anthropogenic source for various pollutants including CO2, CO, and aerosols. This study evaluates the feasibility of using satellite data to characterize gas flaring from space by focusing on the Khanty-Mansiysk Autonomous Okrug in Russia, a region that is well known for its dominant gas flaring activities. Multiple satellite-based thermal anomaly data products at night are intercompared and analyzed, including MODIS (Moderate Resolution Imaging Spectroradiometer) Terra level 2 Thermal Anomalies product (MOD14), MODIS Aqua level 2 Thermal …

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Evaporation From A Shallow, Saline Lake In The Nebraska Sandhills: Energy Balance Drivers Of Seasonal And Interannual Variability, Diego Andrés Riveros-Iregui, John Lenters, Colin Peake, John T. Ong, Nathan C. Healey, Vitaly A. Zlotnik Jan 2017

Evaporation From A Shallow, Saline Lake In The Nebraska Sandhills: Energy Balance Drivers Of Seasonal And Interannual Variability, Diego Andrés Riveros-Iregui, John Lenters, Colin Peake, John T. Ong, Nathan C. Healey, Vitaly A. Zlotnik

Department of Earth and Atmospheric Sciences: Faculty Publications

Despite potential evaporation rates in excess of the local precipitation, dry climates often support saline lakes through groundwater inputs of water and associated solutes. These groundwater-fed lakes are important indicators of environmental change, in part because their shallow water levels and salinity are very sensitive to weather and climatic variability. Some of this sensitivity arises from high rates of open-water evaporation, which is a dominant but poorly quantified process for saline lakes. This study used the Bowen ratio energy budget method to calculate open-water evaporation rates for Alkali Lake, a saline lake in the Nebraska Sandhills region (central United States), …

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Evaluation Of Aerosol Optical Depth And Aerosol Models From Viirs Retrieval Algorithms Over North China Plain, Jun Zhu, Xiangao Xia, Jun Wang, Huizheng Che, Hongbin Chen, Jinqiang Zhang, Xiaoguang Xu, Robert Levy, Min Oo, Robert Holz, Mohammed Ayoub Jan 2017

Evaluation Of Aerosol Optical Depth And Aerosol Models From Viirs Retrieval Algorithms Over North China Plain, Jun Zhu, Xiangao Xia, Jun Wang, Huizheng Che, Hongbin Chen, Jinqiang Zhang, Xiaoguang Xu, Robert Levy, Min Oo, Robert Holz, Mohammed Ayoub

Department of Earth and Atmospheric Sciences: Faculty Publications

The first Visible Infrared Imaging Radiometer Suite (VIIRS) was launched on Suomi National Polar-orbiting Partnership (S-NPP) satellite in late 2011. Similar to the Moderate resolution Imaging Spectroradiometer (MODIS), VIIRS observes top-of-atmosphere spectral reflectance and is potentially suitable for retrieval of the aerosol optical depth (AOD). The VIIRS Environmental Data Record data (VIIRS_EDR) is produced operationally by NOAA, and is based on the MODIS atmospheric correction algorithm. The “MODIS-like” VIIRS data (VIIRS_ML) are being produced experimentally at NASA, from a version of the “dark-target” algorithm that is applied to MODIS. In this study, the AOD and aerosol model types from these …

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Evolution Of A Long-Track Violent Tornado Within A Simulated Supercell, Leigh Orf, Robert Wilhelmson, Bruce Lee, Catherine Finley, Adam L. Houston Jan 2017

Evolution Of A Long-Track Violent Tornado Within A Simulated Supercell, Leigh Orf, Robert Wilhelmson, Bruce Lee, Catherine Finley, Adam L. Houston

Department of Earth and Atmospheric Sciences: Faculty Publications

Utilizing state-of-the-art visualization and analysis software, we explore the evolution of a violent tornado within a simulated supercell thunderstorm and describe associated computational challenges.

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Interactions Of A Paleocene River, A Rising Fold, And Early-Diagenetic Concretions, David B. Loope, Ross Secord Jan 2017

Interactions Of A Paleocene River, A Rising Fold, And Early-Diagenetic Concretions, David B. Loope, Ross Secord

Department of Earth and Atmospheric Sciences: Faculty Publications

The relative rates of sediment accumulation, erosion, and structural uplift determine whether a growing fold develops positive topographic relief, is beveled by antecedent streams, or is buried under thick growth strata. When folds rise in subsiding basins, upward, convergent flow of groundwater through the permeable growth strata that underlie antecedent streams enhances the flux of ions required for concretion growth. Early diagenetic concretions that grow in such alluvial strata may constitute the only clasts larger than sand size available for transport when antecedent streams become erosive. The first reworked concretions deposited by these streams should accurately mark the transition from …

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Polarimetric Radar Metrics Related To Tornado Life Cycles And Intensity In Supercell Storms, Matthew S. Van Den Broeke Jan 2017

Polarimetric Radar Metrics Related To Tornado Life Cycles And Intensity In Supercell Storms, Matthew S. Van Den Broeke

Department of Earth and Atmospheric Sciences: Faculty Publications

Polarimetric radar signatures have been related to the typical evolution of supercell storms, including through tornado life cycles. Now that polarimetric radar observations are available for a large sample of supercell storms, time series of new radar metrics can be derived. These metrics can be compared with phases of known tornado life cycles in an effort to develop new methods of anticipating tornadoes and to increase understanding of storm-scale structural and microphysical changes through supercell and tornado life cycles. In this paper, radar metrics including measures of differential reflectivity ZDR columns, ZDR arcs, polarimetrically inferred hailfall regions, and …

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The Possible Role Of Density Current Dynamics In The Generation Of Low-Level Vertical Vorticity In Supercells, Adam L. Houston Jan 2017

The Possible Role Of Density Current Dynamics In The Generation Of Low-Level Vertical Vorticity In Supercells, Adam L. Houston

Department of Earth and Atmospheric Sciences: Faculty Publications

A physical mechanism based on density current dynamics is proposed to explain the generation of low-level vertical vorticity in supercells. This mechanism may serve as one explanation for the associative relationship between environmental low-level vertical shear and the occurrence of significant tornadoes. The mechanism proposed herein represents an indirect connection to the generation of strong surface-based rotation: the barotropic horizontal vorticity associated with the vertical shear acts to amplify existing rotation but does not directly contribute to surface rotation. The proposed mechanism couples the likelihood of a tornado to the vertical shear through the pattern of vertical motion induced through …

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Crustal Distribution In The Central Gulf Of Mexico From An Integrated Geophysical Analysis, Irina Filina Jan 2017

Crustal Distribution In The Central Gulf Of Mexico From An Integrated Geophysical Analysis, Irina Filina

Department of Earth and Atmospheric Sciences: Faculty Publications

This study addresses the question of the crustal composition in the central part of the northern Gulf of Mexico (GOM) – the region of the major disagreement between published tectonic models. The location of the Ocean-Continental Boundary (OCB) for different tectonic models varies within 140 km (87 mi) in the study area. I have developed a 2D model integrating the seismic reflection and refraction data with potential fields (gravity and magnetics) along the profile through the debated region. Two alternative OCB locations were tested. The preferred model suggests the OCB position near the Sigsbee Escarpment, which is in agreement with …

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Early Miocene Quantitative Calcareous Nannofossil Biostratigraphy From The Tropical Atlantic, Waheed A. Albasrawi, David K. Watkins Jan 2017

Early Miocene Quantitative Calcareous Nannofossil Biostratigraphy From The Tropical Atlantic, Waheed A. Albasrawi, David K. Watkins

Department of Earth and Atmospheric Sciences: Faculty Publications

A quantitative analysis of calcareous nannofossils was conducted on lower Miocene sediments from Ocean Drilling Program Hole 959A on the West African margin. Combined with data from previous investigations of the lower Miocene from the tropical Atlantic, this research identifies and tests the viability of markers used in current zonation schemes, identifies alternative markers for age boundaries, and examines statistically the most probable order of events in the lower Miocene with the use of the ranking and scaling method (RASC).

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Band-To-Band Transitions, Selection Rules, Effective Mass, And Excitonic Contributions In Monoclinic Β-Ga2o3, Alyssa Mock, Rafal Korlacki, Chad Briley, Vanya Darakchieva, Bo Monemar, Yoshinao Kumagai, Ken Goto, Masataka Higashiwaki, Mathias Schubert Jan 2017

Band-To-Band Transitions, Selection Rules, Effective Mass, And Excitonic Contributions In Monoclinic Β-Ga2o3, Alyssa Mock, Rafal Korlacki, Chad Briley, Vanya Darakchieva, Bo Monemar, Yoshinao Kumagai, Ken Goto, Masataka Higashiwaki, Mathias Schubert

Department of Electrical and Computer Engineering: Faculty Publications

We employ an eigenpolarization model including the description of direction dependent excitonic effects for rendering critical point structures within the dielectric function tensor of monoclinic β-Ga2O3 yielding a comprehensive analysis of generalized ellipsometry data obtained from 0.75–9 eV. The eigenpolarization model permits complete description of the dielectric response. We obtain, for single-electron and excitonic band-to-band transitions, anisotropic critical point model parameters including their polarization vectors within the monoclinic lattice. We compare our experimental analysis with results from density functional theory calculations performed using the Gaussian-attenuation-Perdew-Burke-Ernzerhof hybrid density functional. We present and discuss the order of the …

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An Early Semester Mastery Activity And Intervention In First-Year Calculus, Allan P. Donsig, Nathan Wakefield Jan 2017

An Early Semester Mastery Activity And Intervention In First-Year Calculus, Allan P. Donsig, Nathan Wakefield

Department of Mathematics: Faculty Publications

Success in first-year mathematics courses is essential for students to pursue STEM careers, including teaching careers. We investigate a mastery activity given during the first two weeks of a first-year calculus course at the research site. Previous work showed a model using this activity in College Algebra, together with ACT and high school rank, was predictive of student success in precalculus. Here we do a similar analysis for such an activity in calculus, including an intervention for students who do not complete the activity. We also investigate the intervention’s effectiveness. These results show that the early mastery activity, especially when …

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Structure Evolution And Multiferroic Properties In Cobalt Doped Bi4Ndti3Fe1-XCoXO15- Bi3Ndti2Fe1-XCoxo12-Δ Intergrowth Aurivillius Compounds, D. L. Zhang, W. C. Huang, Z. W. Chen, W. B. Zhao, L. Feng, M. Li, Y. W. Yin, S. N. Dong, X. G. Li Jan 2017

Structure Evolution And Multiferroic Properties In Cobalt Doped Bi4Ndti3Fe1-XCoXO15- Bi3Ndti2Fe1-XCoxo12-Δ Intergrowth Aurivillius Compounds, D. L. Zhang, W. C. Huang, Z. W. Chen, W. B. Zhao, L. Feng, M. Li, Y. W. Yin, S. N. Dong, X. G. Li

Department of Physics and Astronomy: Faculty Publications

Here, we report the structure evolution, magnetic and ferroelectric properties in Co-doped 4- and 3-layered intergrowth Aurivillius compounds Bi4NdTi3Fe1-x CoxO15-Bi3NdTi2Fe1-xCoxO12-δ. The compounds suffer a structure evolution from the parent 4-layered phase (Bi4NdTi3FeO15) to 3-layered phase (Bi3NdTi2CoO12-δ) with increasing cobalt doping level from 0 to 1. Meanwhile the remanent magnetization and polarization show opposite variation tendencies against the doping level, and the sample with x = …

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Dualism Between Optical And Difference Parametric Amplification, Wayne Cheng-Wei Huang, Herman Batelaan Jan 2017

Dualism Between Optical And Difference Parametric Amplification, Wayne Cheng-Wei Huang, Herman Batelaan

Department of Physics and Astronomy: Faculty Publications

Breaking the symmetry in a coupled wave system can result in unusual amplification behavior. In the case of difference parametric amplification the resonant pump frequency is equal to the difference, instead of the sum, frequency of the normal modes. We show that sign reversal in the symmetry relation of parametric coupling give rise to difference parametric amplification as a dual of optical parametric amplification. For optical systems, our result can potentially be used for efficient XUV amplification.

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Moving Towards The Magnetoelectric Graphene Transistor, Shi Cao, Zhiyong Xiao, Chun Pui Kwan, Kai Zhang, Jonathan P. Bird, Lu Wang, Wai-Ning Mei, Xia Hong, Peter A. Dowben Jan 2017

Moving Towards The Magnetoelectric Graphene Transistor, Shi Cao, Zhiyong Xiao, Chun Pui Kwan, Kai Zhang, Jonathan P. Bird, Lu Wang, Wai-Ning Mei, Xia Hong, Peter A. Dowben

Xia Hong Publications

The interfacial charge transfer between mechanically exfoliated few-layer graphene and Cr2O3 (0001) surfaces has been investigated. Electrostatic force microscopy and Kelvin probe force microscopy studies point to hole doping of few-layer graphene, with up to a 150 meV shift in the Fermi level, an aspect that is confirmed by Raman spectroscopy. Density functional theory calculations furthermore confirm the p-type nature of the graphene/chromia interface and suggest that the chromia is able to induce a significant carrier spin polarization in the graphene layer. A large magnetoelectrically controlled magneto-resistance can therefore be anticipated in transistor structures based on this …

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Multiple Drivers Of Seasonal Change In Pri: Implications For Photosynthesis 2. Stand Level, Anatoly A. Gitelson, John A. Gamon, Alexei E. Solovchenko Jan 2017

Multiple Drivers Of Seasonal Change In Pri: Implications For Photosynthesis 2. Stand Level, Anatoly A. Gitelson, John A. Gamon, Alexei E. Solovchenko

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The goal of this study was to explore the relationships between stand-level photochemical reflectance index (PRI) and canopy structure/ pigment pools, as well as light use efficiency (LUE) of photosynthetically active vegetation focusing on seasonal or ontogenetic time frames. PRI was originally designed as a means of assessing the xanthophyll cycle and LUE over short (e.g. diurnal) time frames, and few studies have explored the drivers of PRI over longer, seasonal time frames, particularly in crops having different photosynthetic pathways or canopy structures. Consequently, our purpose was to understand and quantify the drivers of PRI responses over seasonal time scales …

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Spatially Biased Dispersal Of Acorns By A Scatter-Hoarding Corvid May Accelerate Passive Restoration Of Oak Habitat On California’S Largest Island, Mario B. Pesendorfer, T. Scott Sillett, Scott A. Morrison Jan 2017

Spatially Biased Dispersal Of Acorns By A Scatter-Hoarding Corvid May Accelerate Passive Restoration Of Oak Habitat On California’S Largest Island, Mario B. Pesendorfer, T. Scott Sillett, Scott A. Morrison

School of Biological Sciences: Faculty Publications

Scatter hoarding by corvids (crows, jays, magpies, and nutcrackers) provides seed dispersal for many large-seeded plants, including oaks and pines. When hoarding seeds, corvids often choose nonrandom locations throughout the landscape, resulting in differential survival of seeds. In the context of habitat restoration, such disproportional storing of seeds in areas suitable for germination and establishment can accelerate expansion and recovery of large-seeded tree populations and their associated ecosystems. Here, we investigate the spatial preferences of island scrub jays Aphelocoma insularis during scatter hoarding of acorns (Quercus spp.) on Santa Cruz Island. We use a large behavioral data set on …

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Comment On “Electronic Structure Of Mo(1−X)Rex Alloys Studied Through Resonant Photoemission Spectroscopy”, Prescott Evans, Peter A. Dowben Jan 2017

Comment On “Electronic Structure Of Mo(1−X)Rex Alloys Studied Through Resonant Photoemission Spectroscopy”, Prescott Evans, Peter A. Dowben

Peter Dowben Publications

Further analysis of the resonant photoemission data, found within Sundar et al (2016 J. Phys.: Condens. Matter 28 315502), show the intensities do not follow the elemental composition in the Mo1−xRex alloy. Similar trends are observed in the published data for Gd1−xNix alloy films. The analysis of the resonant photoemission intensities suggests that Mo in the Mo1−xRex alloy and Gd in the Gd1−xNix alloy have nearest neighbor bonds to Re and Ni respectively. This means the A–B bond is favored over the average of …

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Mesonets: Meso-Scale Weather And Climate Observations For The U.S., Rezaul Mahmood Jan 2017

Mesonets: Meso-Scale Weather And Climate Observations For The U.S., Rezaul Mahmood

School of Natural Resources: Faculty Publications

No abstract provided.

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Droughts Of The Twentieth And Early Twenty First Centuries: Influences On The Production Of Beef And Forage In Kentucky, Usa, Rezaul Mahmood Jan 2017

Droughts Of The Twentieth And Early Twenty First Centuries: Influences On The Production Of Beef And Forage In Kentucky, Usa, Rezaul Mahmood

School of Natural Resources: Faculty Publications

No abstract provided.

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