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Articles 991 - 1020 of 7340

Full-Text Articles in Physical Sciences and Mathematics

Feasibility Of Multi-Year Forecast For The Colorado River Water Supply: Time Series Modeling, Brian Plucinski, Yan Sun, Shih-Yu (Simon) Wang, Robert R. Gilies, James Eklund, Chih-Chia Wang Nov 2019

Feasibility Of Multi-Year Forecast For The Colorado River Water Supply: Time Series Modeling, Brian Plucinski, Yan Sun, Shih-Yu (Simon) Wang, Robert R. Gilies, James Eklund, Chih-Chia Wang

Mathematics and Statistics Faculty Publications

The future of the Colorado River water supply (WS) affects millions of people and the US economy. A recent study suggested a cross-basin correlation between the Colorado River and its neighboring Great Salt Lake (GSL). Following that study, the feasibility of using the previously developed multi-year prediction of the GSL water level to forecast the Colorado River WS was tested. Time-series models were developed to predict the changes in WS out to 10 years. Regressive methods and the GSL water level data were used for the depiction of decadal variability of the Colorado River WS. Various time-series models suggest a …

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Retrieval Of Intrinsic Mesospheric Gravity Wave Parameters Using Lidar And Airglow Temperature And Meteor Radar Wind Data, Robert Reichert, Bernd Kaifler, Natalie Kaifler, Markus Rapp, Pierre-Dominique Pautet, Michael J. Taylor, Alexander Kozlovsky, Mark Lester, Rigel Kivi Nov 2019

Retrieval Of Intrinsic Mesospheric Gravity Wave Parameters Using Lidar And Airglow Temperature And Meteor Radar Wind Data, Robert Reichert, Bernd Kaifler, Natalie Kaifler, Markus Rapp, Pierre-Dominique Pautet, Michael J. Taylor, Alexander Kozlovsky, Mark Lester, Rigel Kivi

Publications

We analyse gravity waves in the upper-mesosphere, lower-thermosphere region from high-resolution temperature variations measured by the Rayleigh lidar and OH temperature mapper. From this combination of instruments, aided by meteor radar wind data, the full set of ground-relative and intrinsic gravity wave parameters are derived by means of the novel WAPITI (Wavelet Analysis and Phase line IdenTIfication) method. This WAPITI tool decomposes the gravity wave field into its spectral component while preserving the temporal resolution, allowing us to identify and study the evolution of gravity wave packets in the varying backgrounds. We describe WAPITI and demonstrate its capabilities for the …

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The Hydrogen Bond: A Hundred Years And Counting, Steve Scheiner Nov 2019

The Hydrogen Bond: A Hundred Years And Counting, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Since its original inception, a great deal has been learned about the nature, properties, and applications of the H-bond. This review summarizes some of the unexpected paths that inquiry into this phenomenon has taken researchers. The transfer of the bridging proton from one molecule to another can occur not only in the ground electronic state, but in various excited states as well. Study of the latter process has developed insights into the relationships between the nature of the state, the strength of the H-bond, and the height of the transfer barrier. The enormous broadening of the range of atoms that …

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Evidence For Large Holocene Earthquakes Along The Denali Fault In Southwest Yukon, Canada, Andrée Blais-Stevens, John J. Clague, Janice Brahney, Panya Lipovsky, Peter J. Haeussler, Brian Menounos Nov 2019

Evidence For Large Holocene Earthquakes Along The Denali Fault In Southwest Yukon, Canada, Andrée Blais-Stevens, John J. Clague, Janice Brahney, Panya Lipovsky, Peter J. Haeussler, Brian Menounos

Watershed Sciences Faculty Publications

The Yukon–Alaska Highway corridor in southern Yukon is subject to geohazards ranging from landslides to floods and earthquakes on faults in the St. Elias Mountains and Shakwak Valley. Here we discuss the late Holocene seismic history of the Denali fault, located at the eastern front of the St. Elias Mountains and one of only a few known seismically active terrestrial faults in Canada. Holocene faulting is indicated by scarps and mounds on late Pleistocene drift and by tectonically deformed Pleistocene and Holocene sediments. Previous work on trenches excavated against the fault scarp near the Duke River reveals paleoseismic sediment disturbance …

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Isotope Summary Data, Andrew Kulmatiski Nov 2019

Isotope Summary Data, Andrew Kulmatiski

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Data includes deuterium tracer uptake data from plant species at the US Sheep Experiment Station.

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Aerial And Ground-Based Optical Gas Imaging Survey Of Uinta Basin Oil And Gas Wells, Seth N. Lyman, Trang Tran, Marc L. Mansfield, Arvind P. Ravikumar Nov 2019

Aerial And Ground-Based Optical Gas Imaging Survey Of Uinta Basin Oil And Gas Wells, Seth N. Lyman, Trang Tran, Marc L. Mansfield, Arvind P. Ravikumar

Bingham Research Center

We deployed a helicopter with an infrared optical gas imaging camera to detect hydrocarbon emissions from 3,428 oil and gas facilities (including 3,225 producing oil and gas well pads) in Utah’s Uinta Basin during winter and spring 2018. We also surveyed 419 of the same well pads from the ground. Winter conditions led to poor contrast between emission plumes and the ground, leading to a detection limit for the aerial survey that was between two and six times worse than a previous summertime survey. Because the ground survey was able to use the camera’s high-sensitivity mode, the rate of detected …

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Structures And Energetics Of Clusters Surrounding Diatomic Anions Stabilized By Hydrogen, Halogen, And Other Noncovalent Bonds, Steve Scheiner, Mariusz Michalczyk, Rafal Wysokiński, Wiktor Zierkiewicz Nov 2019

Structures And Energetics Of Clusters Surrounding Diatomic Anions Stabilized By Hydrogen, Halogen, And Other Noncovalent Bonds, Steve Scheiner, Mariusz Michalczyk, Rafal Wysokiński, Wiktor Zierkiewicz

Chemistry and Biochemistry Faculty Publications

Diatomic anions CN-, NO-, and OH- are surrounded by 2, 3, and 4 ligand molecules drawn from the HF, HCl, XF, YF2, ZF3, TF4, and TrF3 set wherein X= Cl,Br, Y=S,Se, Z=P,As, T=Si,Ge, and Tr=Al,Ga. In the case of two ligands, both interact with the N of NO- and the O of OH-, but one approaches either end of CN-. Unlike the H and halogen bonding units, as the number of ligands increases there is a tendency for chalcogen, pnicogen, tetrel, and triel-bonding ligands to form a cage around the central anion, with strong inter-ligand noncovalent bonds. There are a …

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Aluminum Secondary Electron Yield, Jr Dennison, Phillip Lundgreen Nov 2019

Aluminum Secondary Electron Yield, Jr Dennison, Phillip Lundgreen

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Accurate modeling of spacecraft charging is essential to mitigate well-known and all-too-common deleterious and costly effects on spacecraft resulting from charging induced by interactions with the space plasma environment. This paper addresses how limited availability of electron emission and transport properties of spacecraft materials—in particular secondary electron yields—and the wide range measured for such properties pose a critical issue for modeling spacecraft charging. It describes a materials charging database being developed, which when used in concert with the strategies outlined herein for best practices for establishing optimized materials properties for spacecraft charging models and specific mission requirements and how these …

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Melissa: System Description And Spectral Features Of Pre- And Post-Midnight F-Region Echoes, Fabiano S. Rodrigues, Weijia Zhan, Marco A. Milla, B. G. Fejer, Eurico R. De Paula, Acacio C. Neto, Angela M. Santos, Inez S. Batista Nov 2019

Melissa: System Description And Spectral Features Of Pre- And Post-Midnight F-Region Echoes, Fabiano S. Rodrigues, Weijia Zhan, Marco A. Milla, B. G. Fejer, Eurico R. De Paula, Acacio C. Neto, Angela M. Santos, Inez S. Batista

All Physics Faculty Publications

Most of the low‐latitude ionospheric radar observations in South America come from the Jicamarca Radio Observatory, located in the western longitude sector (∼75°W). The deployment of the 30 MHz FAPESP‐Clemson‐INPE (FCI) coherent backscatter radar in the magnetic equatorial site of São Luis, Brazil, in 2001 allowed observations to be made in the eastern sector (∼45°W). However, despite being operational for several years (2001–2012), FCI only made observations during daytime and pre‐midnight hours, with a few exceptions. Here, we describe an upgraded system that replaced the FCI radar and present results of full‐night F‐region observations. This radar is referred to …

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The Total Syntheses Of Jbir-94 And Two Synthetic Analogs And Their Cytotoxicities Against A549 (Ccl-185) Human Small Lung Cancer Cells, Cathy L. Mangum, Mica B. Munford, Alyssa Sam, Sandra K. Young, Jeremy T. Beales, Yagya Prasad Subedi, Chad D. Mangum, Tanner J. Allen, Miranda S. Liddell, Andrew I. Merrell, Diana I. Saavedra, Becky L. Williams, Nicole Evans, Joseph L. Beales, Mike A. Christiansen Nov 2019

The Total Syntheses Of Jbir-94 And Two Synthetic Analogs And Their Cytotoxicities Against A549 (Ccl-185) Human Small Lung Cancer Cells, Cathy L. Mangum, Mica B. Munford, Alyssa Sam, Sandra K. Young, Jeremy T. Beales, Yagya Prasad Subedi, Chad D. Mangum, Tanner J. Allen, Miranda S. Liddell, Andrew I. Merrell, Diana I. Saavedra, Becky L. Williams, Nicole Evans, Joseph L. Beales, Mike A. Christiansen

Chemistry and Biochemistry Faculty Publications

We here disclose the total syntheses of the natural polyphenol JBIR-94 and two nonnatural analogs, whose structures are of interest for their bioactivity potential as radical scavengers. Although we initially attempted this by dually acylating both of putrecine’s amine nitrogens in a single pot, our endeavors with this method (which has been successfully reported by other groups) proved ineffectual. We accordingly opted for the lengthier approach of acylating each amine individually, which gratuitously prevailed and also aligns with separate literature precedent. Moreover, we here share our analysis of these target compounds’ cytotoxicities and IC50 values against A549 (CCL-185) human …

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An Efficient Viologen-Based Electron Donor To Nitrogenase, Artavazd Badalyan, Zhi-Yong Yang, Bo Hu, Jian Luo, Maowei Hu, T. Leo Liu, Lance C. Seefeldt Nov 2019

An Efficient Viologen-Based Electron Donor To Nitrogenase, Artavazd Badalyan, Zhi-Yong Yang, Bo Hu, Jian Luo, Maowei Hu, T. Leo Liu, Lance C. Seefeldt

Chemistry and Biochemistry Faculty Publications

Nitrogenase catalyzes the reduction of N2 to NH3, supporting all biological nitrogen fixation. Electron donors to this enzyme are ferredoxin or flavodoxin (in vivo) and sodium dithionite (in vitro). Features of these electron donors put a limit on spectrophotometric studies and electrocatalytic applications of nitrogenase. Although it is common to use methyl viologen as an electron donor for many low-potential oxidoreductases, decreased nitrogenase activity is observed with an increasing concentration of methyl viologen, limiting its utility under many circumstances. In this work, we suggest that this concentration-dependent decrease in activity can be explained …

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Nonlinear Reaction–Diffusion Process Models Improve Inference For Population Dynamics, Xinyi Lu, Perry J. Williams, Mevin B. Hooten, James A. Powell, Jamie N. Womble, Michael R. Bower Nov 2019

Nonlinear Reaction–Diffusion Process Models Improve Inference For Population Dynamics, Xinyi Lu, Perry J. Williams, Mevin B. Hooten, James A. Powell, Jamie N. Womble, Michael R. Bower

Mathematics and Statistics Faculty Publications

Partial differential equations (PDEs) are a useful tool for modeling spatiotemporal dynamics of ecological processes. However, as an ecological process evolves, we need statistical models that can adapt to changing dynamics as new data are collected. We developed a model that combines an ecological diffusion equation and logistic growth to characterize colonization processes of a population that establishes long‐term equilibrium over a heterogeneous environment. We also developed a homogenization strategy to statistically upscale the PDE for faster computation and adopted a hierarchical framework to accommodate multiple data sources collected at different spatial scales. We highlighted the advantages of using a …

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Salt Tolerance Of Sego Supremetm Plants, Asmita Paudel, Ji Jhong Chen, Youping Sun, Yuxiang Wang, Richard M. Anderson Nov 2019

Salt Tolerance Of Sego Supremetm Plants, Asmita Paudel, Ji Jhong Chen, Youping Sun, Yuxiang Wang, Richard M. Anderson

Plants, Soils, and Climate Faculty Publications

Sego SupremeTM is a designated plant breeding and introduction program at the Utah State University Botanical Center and the Center for Water Efficient Landscaping. This plant selection program introduces native and adapted plants to the arid West for aesthetic landscaping and water conservation. The plants are evaluated for characteristics such as color, flowering, ease of propagation, market demand, disease/pest resistance, and drought tolerance. However, salt tolerance has not been considered during the evaluation processes. Four Sego SupremeTM plants [Aquilegia barnebyi (oil shale columbine), Clematis fruticosa (Mongolian gold clematis), Epilobium septentrionale (northern willowherb), and Tetraneuris acaulis var. arizonica …

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Individual Variation And Ecotypic Niches In Simulations Of The Impact Of Climatic Volatility, George P. Malanson, R. Justin Derose, Matthew F. Bekker Nov 2019

Individual Variation And Ecotypic Niches In Simulations Of The Impact Of Climatic Volatility, George P. Malanson, R. Justin Derose, Matthew F. Bekker

Wildland Resources Faculty Publications

Expectations of the impacts of climatic variation on species can depend on whether and how intraspecific variability is incorporated in models. Coefficients of variation from tree-ring records of Pinus albicaulis through time and across space were used to parameterize volatility and individuality, respectively. The records across sites were used to differentiate the average modes on an environmental gradient for Gaussian fitness of ecotypic niches, and to add further individual variation in mode and standard deviation of these functions in individual-based Monte Carlo simulations of reproduction and mortality with inheritance of individual variability. Ecotypic gamma and Shannon diversity decreased with volatility …

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Embedding The Su(3) Sector Of So(8) Supergravity In D = 11, Gabriel Larios, Praxitelis Ntokos, Oscar J. Varela Oct 2019

Embedding The Su(3) Sector Of So(8) Supergravity In D = 11, Gabriel Larios, Praxitelis Ntokos, Oscar J. Varela

All Physics Faculty Publications

The SU(3)-invariant sector of maximal supergravity in four dimensions with an SO(8) gauging is uplifted to D = 11 supergravity. In order to do this, the SU(3)-neutral sector of the tensor and duality hierarchies of the D = 4 �� = 8 supergravity is first worked out. The consistent D = 11 embedding of the full, dynamical SU(3) sector is then expressed at the level of the D = 11 metric and three-form gauge field in terms of these D = 4 tensors. The redundancies introduced by this approach are eliminated at the level of the D = 11 four-form …

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The Role Of The Dispersion Parameter In Electrical Properties Of Highly Disordered Insulating Materials, Zachary Gibson Oct 2019

The Role Of The Dispersion Parameter In Electrical Properties Of Highly Disordered Insulating Materials, Zachary Gibson

Physics Student Research

Charge transport in disordered solids can be described with use of a dispersion parameter. The dispersion parameter can be defined simply as either the thermal energy (low electric field regime) or the field energy (high field regime) scaled by the reciprocal of a characteristic energy of the material. A transitionary temperature and electric field are defined when the ratio of thermal or field energy over the characteristic energy is one, respectively. This indicates a transition from dispersive transport to normal transport. Dispersive transport can be described simply by the dispersion parameter for many disordered materials. Models involving the dispersion parameter …

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Minimal D = 4 �� = 2 Supergravity From D = 11: An M-Theory Free Lunch, Gabriel Larios, Oscar J. Varela Oct 2019

Minimal D = 4 �� = 2 Supergravity From D = 11: An M-Theory Free Lunch, Gabriel Larios, Oscar J. Varela

All Physics Faculty Publications

We present a new consistent truncation of D = 11 supergravity to D = 4 �� = 2 minimal gauged supergravity, on the seven-dimensional internal Riemannian space corresponding to the most general class of D = 11 solutions with an AdS4 factor and �� = 2 supersymmetry. A truncation ansatz is proposed and its consistency checked at the level of the D = 11 Bianchi identity, bosonic equations of motion, and supersymmetry variations of the gravitino. The general class includes an �� = 2 AdS4 solution dual to the conformal, low energy physics phase corresponding to a mass …

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Fate Of The Organophosphate Insecticide, Chlorpyrifos, In Leaves, Soil, And Air Following Application, Supta Das, Kimberly J. Hageman, Madeleine Taylor, Sue Michelsen-Heath, Ian Stewart Oct 2019

Fate Of The Organophosphate Insecticide, Chlorpyrifos, In Leaves, Soil, And Air Following Application, Supta Das, Kimberly J. Hageman, Madeleine Taylor, Sue Michelsen-Heath, Ian Stewart

Chemistry and Biochemistry Faculty Publications

A field study was conducted to further our understanding about the fate and transport of the organophosphate insecticide, chlorpyrifos, and its degradation product, chlorpyrifos oxon. Leaf, soil and air sampling was conducted for 21 days after chlorpyrifos application to a field of purple tansy (Phacelia tanacetifolia). Air samples were collected using a high-volume air sampler (HVAS) and seven battery-operated medium-volume active air samplers placed around the field and on a 500-m transect extending away from the field. Chlorpyrifos was detected every day of the sampling period in all matrices, with concentrations decreasing rapidly after application. Chlorpyrifos oxon was …

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Physics-Driven Dual-Defect Model Fits Of Voltage Step-Up To Breakdown Data In Spacecraft Polymers, Allen Andersen, Jr Dennison Oct 2019

Physics-Driven Dual-Defect Model Fits Of Voltage Step-Up To Breakdown Data In Spacecraft Polymers, Allen Andersen, Jr Dennison

Journal Articles

Overly conservative estimates of breakdown strength can increase the mass and cost of spacecraft electrostatic discharge (ESD) mitigation methods. Improved estimates of ESD likelihood in the space environment require better models of ESD distributions. The purpose of this work is to evaluate our previously proposed dual-defect model of voltage step-up-to-breakdown tests with a case study across four dielectric materials. We predicted that materials best fit by mixed Weibull distributions would exhibit better fits with the dual-defect model compared to a mean field single defect theory. Additional data for biaxially oriented polypropylene (BOPP), polyimide (PI or Kapton) from three sources, and …

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Aromatic Character Of [Au13]5+ And [Mau12]4+/6+ (M = Pd, Pt) Cores In Ligand Protected Gold Nanoclusters – Interplay Between Spherical And Planar Σ-Aromatics, Nikita Fedik, Alexander I. Boldyrev, Alvaro Muñoz-Castro Oct 2019

Aromatic Character Of [Au13]5+ And [Mau12]4+/6+ (M = Pd, Pt) Cores In Ligand Protected Gold Nanoclusters – Interplay Between Spherical And Planar Σ-Aromatics, Nikita Fedik, Alexander I. Boldyrev, Alvaro Muñoz-Castro

Chemistry and Biochemistry Faculty Publications

The most characteristic feature of planar π-aromatics is the ability to sustain a long-range shielding cone under a magnetic field oriented in a specific direction. In this article, we showed that similar magnetic responses can be found in σ-aromatic and spherical aromatic systems. For [Au13]5+, long-range characteristics of the induced magnetic field in the bare icosahedral core are revealed, which are also found in the ligand protected [Au25(SH)18]− model, proving its spherical aromatic properties, also supported by the AdNDP analysis. Such properties are given by the 8-ve of the structural core satisfying …

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Hemispherical Shifted Symmetry In Polar Cap Patch Occurrence: A Survey Of Gps Tec Maps From 2015–2018, Michael David, Jan Josef Sojka, Robert W. Schunk, Anthea J. Coster Oct 2019

Hemispherical Shifted Symmetry In Polar Cap Patch Occurrence: A Survey Of Gps Tec Maps From 2015–2018, Michael David, Jan Josef Sojka, Robert W. Schunk, Anthea J. Coster

All Physics Faculty Presentations

Much theoretical and observational work has been devoted to studying the occurrence of F region polar cap patches in the Northern Hemisphere; considerably less work has been applied to the Southern Hemisphere. In recent years, the Madrigal database of mappings of total electron content (TEC) has improved in Southern Hemisphere coverage, to the point that we can now carry out a study of patch frequency and occurrence. We find that Southern Hemisphere patch occurrence is very similar to that of the Northern Hemisphere with a half‐year offset, plus an offset in universal time of approximately 12 hr. This is further …

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Nanoscale Evidence For Temperature-Induced Transient Rheology And Postseismic Fault Healing, Alexis K. Ault, Jordan L. Jensen, Robert G. Mcdermott, F.-A. Shen, B. R. Van Devener Oct 2019

Nanoscale Evidence For Temperature-Induced Transient Rheology And Postseismic Fault Healing, Alexis K. Ault, Jordan L. Jensen, Robert G. Mcdermott, F.-A. Shen, B. R. Van Devener

Geosciences Faculty Publications

Friction-generated heat and the subsequent thermal evolution control fault material properties and thus strength during the earthquake cycle. We document evidence for transient, nanoscale fault rheology on a high-gloss, light-reflective hematite fault mirror (FM). The FM cuts specularite with minor quartz from the Pleistocene El Laco Fe-ore deposit, northern Chile. Scanning and transmission electron microscopy data reveal that the FM volume comprises a2+ suboxides. Sub–5-nm-thick silica films encase hematite grains and connect to amorphous interstitial silica. Observations imply that coseismic shear heating (temperature >1000 °C) generated transiently amorphous, intermixed but immiscible, and rheologically weak Fe-oxide and silica. Hematite regrowth in …

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A Unified Description Of The Electrical Properties Of Low-Density Polyethylene Via The Dispersion Parameter, Zack Gibson, Megan Loveland, Jr Dennison Oct 2019

A Unified Description Of The Electrical Properties Of Low-Density Polyethylene Via The Dispersion Parameter, Zack Gibson, Megan Loveland, Jr Dennison

Physics Student Research

Low-density polyethylene is a prototypical highly disordered insulating material. This ubiquitous polymer has a variety of applications from spacecraft charging to high voltage DC power cable insulation. Therefore, the electrical properties are of great interest. The dispersion parameter, which originally appeared in a semi-empirical model to describe anomalies in permittivity data, is central to an understanding of these electrical properties. This parameter depends linearly on either temperature (low field regime) or on electric field (high field regime) and is scaled by the reciprocal of a characteristic energy. When the dispersion parameter reaches one, a transition from dispersive to non-dispersive transport …

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Ensemble Streamflow Forecasting Using An Energy Balance Snowmelt Model Coupled To A Distributed Hydrologic Model With Assimilation Of Snow And Streamflow Observations, Tseganeh Zekiewos Gichamo, David G. Tarboton Oct 2019

Ensemble Streamflow Forecasting Using An Energy Balance Snowmelt Model Coupled To A Distributed Hydrologic Model With Assimilation Of Snow And Streamflow Observations, Tseganeh Zekiewos Gichamo, David G. Tarboton

Publications

In many river basins across the world, snowmelt is an important source of streamflow. However, detailed snowmelt modeling is hampered by limited input data and uncertainty arising from inadequate model structure and parametrization. Data assimilation that updates model states based on observations, reduces uncertainty and improves streamflow forecasts. In this study, we evaluated the Utah Energy Balance (UEB) snowmelt model coupled to the Sacramento Soil Moisture Accounting (SAC‐SMA) and rutpix7 stream routing models, integrated within the Research Distributed Hydrologic Model (RDHM) framework for streamflow forecasting. We implemented an ensemble Kalman filter for assimilation of snow water equivalent (SWE) observations in …

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Charge Transport In Disordered Materials And The Dispersion Parameter, Zachary Gibson Oct 2019

Charge Transport In Disordered Materials And The Dispersion Parameter, Zachary Gibson

Physics Student Research

Charge transport in disordered solids can be described with use of a dispersion parameter. The dispersion parameter can be defined simply as either the thermal energy (low electric field regime) or the field energy (high field regime) scaled by the reciprocal of a characteristic energy of the material. A transitionary temperature and electric field are defined when the ratio of thermal or field energy over the characteristic energy is one, respectively. This indicates a transition from dispersive transport to normal transport. Dispersive transport can be described simply by the dispersion parameter for many disordered materials. Models involving the dispersion parameter …

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Data From: Cavitation Clusters In Lipid Systems – The Generation Of A Bifurcated Streamer And The Dual Collapse Of A Bubble Cluster, Silvana Martini, Peter Birkin, Tadd T. Truscott Oct 2019

Data From: Cavitation Clusters In Lipid Systems – The Generation Of A Bifurcated Streamer And The Dual Collapse Of A Bubble Cluster, Silvana Martini, Peter Birkin, Tadd T. Truscott

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Over the past decade several studies have reported the use of high intensity ultrasound (HIU) to induce the crystallization of lipids. The effect that HIU has on lipid crystallization is usually attributed to the generation of cavities but acoustic cavitation has never been fully explored in lipids. The dynamics of a particular cavitation cluster next to a piston like emitter in an oil, was investigated in this study. The lipid systems, which are important in food processing, are studied with high-speed camera imaging, laser scattering and pressure measurements. A sequence of stable clusters were noted. In addition, a bifurcated streamer …

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Differences In Drought Tolerance Among Gisela® Cherry Rootstocks Determined Using Automated Weighing Lysimeters, Lance V. Stott, Brent Black, Bruce Bugbee Oct 2019

Differences In Drought Tolerance Among Gisela® Cherry Rootstocks Determined Using Automated Weighing Lysimeters, Lance V. Stott, Brent Black, Bruce Bugbee

Plants, Soils, and Climate Faculty Publications

The Gisela® series of dwarfing rootstock are widely used because they enable high-density production, but they may be sensitive to drought. Drought tolerance may be associated with root-zone distribution and depth or with physiological adaptation to low water potential. Here we describe a novel technique for determining physiological tolerance to drought when root distribution is held constant. In two matching studies, we continuously measured transpiration of two groups of eight trees using a 16-container automated weighing lysimeter system in a greenhouse. With this system, Gisela® 3, 5, and 12 (G.3, G.5, and G.12) rootstocks were subjected to multiple, controlled drought …

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Dynamic Secondary Electron Emission In Rough Composite Materials, Leandro Olano, Maria E. Dávila, John R. Dennison, Petronilo Martín-Iglesias, Isabel Montero Sep 2019

Dynamic Secondary Electron Emission In Rough Composite Materials, Leandro Olano, Maria E. Dávila, John R. Dennison, Petronilo Martín-Iglesias, Isabel Montero

All Physics Faculty Publications

The interaction of ionizing radiation with matter is of critical importance in numerous areas of science and technology like space and vacuum technology and even medicine and biotechnology. Secondary electron emission is a consequence of electron irradiation on materials. We achieve extremely low secondary electron emission yield values smaller than 0.2, even up to incident electron energies ~1 keV, due to an undocumented synergy between neighbouring metal and dielectric domains in composite samples. To investigate this experimental discovery, we propose a simple 3D model where the dielectric and metallic domains are arranged in parallel and interleaved. The proposed surface profile …

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Definition Of The Chalcogen Bond (Iupac Recommendations 2019), Christer B. Aakeroy, David L. Bryce, Gautam R. Desiraju, Antonio Frontera, Anthony C. Legon, Francesco Nicotra, Kari Rissanen, Steve Scheiner, Giancarlo Terraneo, Pierangelo Metrangolo, Giuseppe Resnati Sep 2019

Definition Of The Chalcogen Bond (Iupac Recommendations 2019), Christer B. Aakeroy, David L. Bryce, Gautam R. Desiraju, Antonio Frontera, Anthony C. Legon, Francesco Nicotra, Kari Rissanen, Steve Scheiner, Giancarlo Terraneo, Pierangelo Metrangolo, Giuseppe Resnati

Chemistry and Biochemistry Faculty Publications

This recommendation proposes a definition for the term “chalcogen bond”; it is recommended the term is used to designate the specific subset of inter- and intramolecular interactions formed by chalcogen atoms wherein the Group 16 element is the electrophilic site.

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The Physical Significance Of Α For Electron Transport, Zachary Gibson Sep 2019

The Physical Significance Of Α For Electron Transport, Zachary Gibson

Physics Student Research

Charge transport in crystalline materials can be well understood through the use of Bloch functions, band theory, and extended state transport. Disordered materials do not allow the same luxury, and different methods have to be considered. It turns out that band structures still exist. Although extended state conduction can still occur, localized states within the band gap allow for alternative mechanisms of charge transport in disordered materials. Conduction can be understood through such models as hopping, multiple trapping, and percolation, but all of them can lead to a broad distribution of event times. For example, the hopping-time distribution proposed by …

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