Physical Sciences and Mathematics Commons^™

Regional Distribution Of Mesospheric Small‐Scale Gravity Waves During Deepwave, Pierre-Dominique Pautet, Michael J. Taylor, S. D. Eckermann, Neal R. Criddle

Publications

The Deep Propagating Gravity Wave Experiment project took place in June and July 2014 in New Zealand. Its overarching goal was to study gravity waves (GWs) as they propagate from the ground up to ~100 km, with a large number of ground‐based, airborne, and satellite instruments, combined with numerical forecast models. A suite of three mesospheric airglow imagers operated onboard the NSF Gulfstream V (GV) aircraft during 25 nighttime flights, recording the GW activity at OH altitude over a large region (>7,000,000 km²). Analysis of this data set reveals the distribution of the small‐scale GW mean power …

Open/Closed Boundary And Energy Cutoff Latitude Data For Papers 1 And 2, David Alan Smith

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Abstract for Paper 1: The open-closed boundary (OCB) defines a region of significant transformation in Earth's protective magnetic shield. Principle among these changes is the transition of magnetic field lines from having two foot points, one in each hemisphere, to one foot point at Earth, the other mapping to the solar wind (SW). Charged particles in the SW are able to follow these open field lines into Earth's upper atmosphere. The OCB also defines the polar cap boundary (PCB). Being able to identify and track the OCB allows study of several components of the geomagnetic system. Among them are the …

Comparison Of Halogen With Proton Transfer. Symmetric And Asymmetric Systems, Jia Lu, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The transfer of the halogen atom X within (A⸳⸳X⸳⸳A)+ systems was calculated for A = NH3, OH2, and CH3, and where X=Cl, Br, and I. These potentials are similar to those computed for equivalent proton transfers. Each contains a single symmetric well for short R(A⸳⸳A) distances. As R is stretched a second minimum appears, separated from the first by a transfer barrier E† which climbs quickly as R is elongated. The central X prefers association with the N in asymmetric systems (H3NX⸳⸳OH2)+, but a second (H3N⸳⸳XOH2)+ minimum, albeit less stable than the first, can appear if R(N⸳⸳O) is stretched.

The Impact Of Energetic Neutral Particles Raining Down On The Thermosphere Due To Charge Exchange Reactions In The Upper Ionosphere And Polar Wind, Larry Gardner

Funded Research Records

No abstract provided.

Collaborative Research: Tespresso, Tectonic Encoding, Shredding, And Propagation Of Environmental Signals As Surficial Observables, Tammy M. Rittenour

Funded Research Records

No abstract provided.

The Ability Of A Tetrel Bond To Transition A Neutral Amino Acid Into A Zwitterion, Mingchang Hou, Qing-Zhong Li, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The interaction between glycine and F2CO/F2SiO occurs through the formation of a π-tetrel bond between the C/Si atom and a carboxyl O atom. The interaction energy is some 20 kJ/mol for the C···O tetrel bond, but exceeds 300 kJ/mol for Si···O. As part of the latter complexation process, the proton engaged in the intramolecular OH··N H-bond is transferred across to the N, forming a zwitterion. This Si···O tetrel bond is more effective at inducing this proton transfer than is placement of the glycine in an aqueous medium, complexation with an anionic BH4-, or adding an electron to the glycine.

On The Balance Between Plasma And Magnetic Pressure Across Equatorial Plasma Depletions, J. Rodríguez-Zuluaga, C. Stolle, Y. Yamazaki, H. Lühr, J. Park, Ludger Scherliess, J. L. Chau

All Physics Faculty Publications

In magnetized plasmas such as the ionosphere, electric currents develop in regions of strong density gradients to balance the resulting plasma pressure gradients. These currents, usually known as diamagnetic currents decrease the magnetic pressure where the plasma pressure increases, and vice versa. In the low‐latitude ionosphere, equatorial plasma depletions (EPDs) are well known for their steep plasma density gradients and adverse effect on radio wave propagation. In this paper, we use continuous measurements of the magnetic field and electron density from the European Space Agency's Swarm constellation mission to assess the balance between plasma and magnetic pressure across large‐scale EPDs. …

Comparison Between Hydrogen And Halogen Bonds In Complexes Of 6-Ox-Fulvene With Pnicogen And Chalcogen Electron Donors, Mingchang Hou, Qing-Zhong Li, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Quantum chemical calculations are applied to complexes of 6‐OX‐fulvene (X=H, Cl, Br, I) with ZH3/H2Y (Z=N, P, As, Sb; Y=O, S, Se, Te) to study the competition between the hydrogen bond and the halogen bond. The H‐bond weakens as the base atom grows in size and the associated negative electrostatic potential on the Lewis base atom diminishes. The pattern for the halogen bonds is more complicated. In most cases, the halogen bond is stronger for the heavier halogen atom, and pnicogen electron donors are more strongly bound than chalcogen. Halogen bonds to chalcogen atoms strengthen in the order O

Equatorial Disturbance Dynamo Vertical Plasma Drifts Over Jicamarca: Bi‐Monthly And Solar Cycle Dependence, Luis A. Navarro Dominguez, B. G. Fejer, Ludger Scherliess

All Physics Faculty Publications

We use extensive incoherent scatter radar observations from the Jicamarca Radio Observatory to study the local time and bi‐monthly dependence of the equatorial disturbance dynamo vertical plasma drifts on solar flux and geomagnetic activity. We show that the daytime disturbance drifts have generally small magnitudes with largest values before noon and an apparent annual variation. Near dusk, they are downward throughout the year with largest values during the equinoxes and smallest during June solstice. These downward drifts increase strongly with solar flux, and shift to later local times. They also increase with increasing geomagnetically active conditions with no apparent local …

Deformation Conditions During Syn-Convergent Extension Along The Cordillera Blanca Shear Zone, Peru, Cameron A. Hughes, Micah J. Jessup, Colin A. Shaw, Dennis L. Newell

Geosciences Faculty Publications

Strain localization across the brittle-ductile transition is a fundamental process in accommodating tectonic movement in the mid-crust. The tectonically active Cordillera Blanca shear zone (CBSZ), a ∼200-km-long normal-sense shear zone situated within the footwall of a discrete syn-convergent extensional fault in the Peruvian Andes, is an excellent field laboratory to explore this transition. Field and microscopic observations indicate consistent top-down-to-the-southwest sense of shear and a sequence of tectonites ranging from undeformed granodiorite through mylonite and ultimately fault breccia along the detachment.

Using microstructural analysis, two-feldspar and Ti-in-quartz (TitaniQ) thermometry, recrystallized quartz paleopiezometry, and analysis of quartz crystallographic preferred orientations, we …

Consumption Of Black Raspberries Altered The Composition Of The Fecal Microbiome In Mice Fed A Western Type Diet (Or04-01-19), Abby D. Benninghoff, Sumira Phatak, Korry Hintze

Chemistry and Biochemistry Faculty Publications

Dietary strategies to reduce colonic inflammation and promote gut homeostasis may markedly reduce the risk of colitis-associated colorectal cancer. Previously, we showed that dietary supplementation with black raspberries significantly suppressed colitis and colon tumorigenesis promoted by the consumption a Western type diet in mice. In this study, our goal was to assess the impact of consumption of the TWD with and without black raspberry supplementation on the composition of the fecal microbiome over the course of disease development.

Dietary Intervention With Black Raspberries To Reduce Colitis Symptoms In Mice Fed Either Standard Ain93g Diet Or The Total Western Diet (P05-021-19), Daphne Michelle Rodriguez Jimenez, Michaela Brubaker, Elizabeth Park, Canyon Neal, Korry Hintze, Abby D. Benninghoff

Chemistry and Biochemistry Faculty Publications

Approximately 1.4 million people suffer from inflammatory bowel disease, which is a major risk factor for developing colitis associated colorectal cancer (CAC). Dietary interventions with the goal to reduce colon inflammation and encourage gut microbiome homeostasis may be a strategy to reduce the risk of CAC. The antioxidants and anti-inflammatory compounds present in black raspberries (BRB) have demonstrated protective effects in the colon epithelium and may alter the composition of the gut microbiome. Previously, we showed that dietary supplementation with black raspberries significantly suppressed colitis and colon tumorigenesis promoted by the consumption of a Western type diet in mice. The …

Quantifying Methane Emissions In The Uintah Basin During Wintertime Stagnation Episodes, C. S. Foster, Erik T. Crosman, J. D. Horel, Seth Lyman, B. Fasoli, R. Bares, J. C. Lin

Bingham Research Center

This study presents a meteorologically-based methodology for quantifying basin-scale methane (CH₄) emissions in Utah’s Uintah Basin, which is home to over 9,000 active and producing oil and natural gas wells. Previous studies in oil and gas producing regions have often relied on intensive aircraft campaigns to estimate methane emissions. However, the high cost of airborne campaigns prevents their frequent undertaking, thus providing only daytime snapshots of emissions rather than more temporally-representative estimates over multiple days. Providing estimates of CH₄ emissions from oil and natural gas production regions across the United States is important to inform leakage rates …

Blandford-Znajek Process In Vacuo And Its Holographic Dual, Ted Jacobson, Maria J. Rodriguez

All Physics Faculty Presentations

Blandford and Znajek discovered a process by which a spinning black hole can transfer rotational energy to a plasma, offering a mechanism for energy and jet emissions from quasars. Here we describe a version of this mechanism that operates with only vacuum electromagnetic fields outside the black hole. The setting, which is not astrophysically realistic, involves either a cylindrical black hole or one that lives in 2+1 spacetime dimensions, and the field is given in simple, closed form for a wide class of metrics. For asymptotically anti–de Sitter black holes in 2+1 dimensions, the holographic dual of this mechanism is …

Enabling Multi-Hop Remote Method Invocation In Device-To-Device Networks, Minh Le, Stephen Clyde, Young‑Woo Kwon

Computer Science Faculty and Staff Publications

To avoid shrinking down the performance and preserve energy, low-end mobile devices can collaborate with the nearby ones by offloading computation intensive code. However, despite the long research history, code offloading is dilatory and unfit for applications that require rapidly consecutive requests per short period. Even though Remote Procedure Call (RPC) is apparently one possible approach that can address this problem, the RPC-based or message queue-based techniques are obsolete or unwieldy for mobile platforms. Moreover, the need of accessibility beyond the limit reach of the device-to-device (D2D) networks originates another problem. This article introduces a new software framework to overcome …

Interfacial Amino Acids Support Spa47 Oligomerization And Shigella Type Three Secretion System Activation, Hannah J. Demler, Heather B. Case, Yalemi Morales, Abram R. Bernard, Sean J. Johnson, Nicholas E. Dickenson

Chemistry and Biochemistry Faculty Publications

Like many Gram-negative pathogens, Shigella rely on a type three secretion system (T3SS) for injection of effector proteins directly into eukaryotic host cells to initiate and sustain infection. Protein secretion through the needle-like type three secretion apparatus (T3SA) requires ATP hydrolysis by the T3SS ATPase Spa47, making it a likely target for in vivo regulation of T3SS activity and an attractive target for small molecule therapeutics against shigellosis. Here, we developed a model of an activated Spa47 homo-hexamer, identifying two distinct regions at each protomer interface that we hypothesized to provide intermolecular interactions supportingSpa47 oligomerization and enzymatic activation. Mutational analysis …

Forty Years Of Progress In The Study Of The Hydrogen Bond, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The author looks back at developments over the last few decades concerning the H–bond. The list of atoms involved as proton donor and acceptor has broadened dramatically, including most electronegative atoms and even metals. The factors that control the transfer of the proton across the H–bond have been elucidated and show the importance of even minor changes in its geometry. Small stretches can shut down the transfer entirely, and certain bends can force a proton to transfer against a pK gradient. Along with the recognition that a CH..O interaction can represent a true H–bond, and one with strength comparable to …

The Slow Displacement Of Smallholder Farming Families: Land, Hunger, And Labor Migration In Nicaragua And Guatemala, Lindsey Carte, Birgit Schmook, Claudia Radel, Richard Johnson

Environment and Society Faculty Publications

Smallholders worldwide continue to experience processes of displacement from their lands under neoliberal political-economic governance. This displacement is often experienced as “slow”, driven by decades of agricultural policies and land governance regimes that favor input-intensive agricultural and natural resource extraction and export projects at the expense of traditional agrarian practices, markets, and producers. Smallholders struggle to remain viable in the face of these forces, yet they often experience hunger. To persist on the land, often on small parcels, families supplement and finance farm production with family members engaging in labor migration, a form of displacement. Outcomes, however, are uneven and …

Usu Materials Physics Group Nasa Missions, Jr Dennison

Posters

No abstract provided.

A 3d Numerical Study Of Interface Effects Influencing Viscous Gravity Currents In A Parabolic Fissure, With Implications For Modeling With 1d Nonlinear Diffusion Equations, Eden Furtak-Cole, Aleksey S. Telyakovskiy

Mathematics and Statistics Student Research and Class Projects

Although one-dimensional non-linear diffusion equations are commonly used to model flow dynamics in aquifers and fissures, they disregard multiple effects of real-life flows. Similarity analysis may allow further analytical reduction of these equations, but it is often difficult to provide applicable initial and boundary conditions in practice, or know the magnitude of effects neglected by the 1D model. Furthermore, when multiple simplifying assumptions are made, the sources of discrepancy between modeled and observed data are difficult to identify. We derive one such model of viscous flow in a parabolic fissure from first principals. The parabolic fissure is formed by extruding …

Tdim Ionospheric Model Tec Maps Of The High-Latitude Northern Hemisphere, Used In The Paper Titled "Hemispherical Shifted Symmetry In Polar Cap F-Region Patch Occurrence: A Survey Of Gps Tec Data From 2015 To 2018", Michael David, Jan J. Sojka

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TDIM ionospheric model was run for the year 2018 at 10-day intervals and 2-hr intervals in UT.

Combining Geographic Information Systems And Agent-Based Models In Archaeology: Part 2 Of 3, Benjamin Davies, Iza Romanowska, Kathryn Harris, Stefani Crabtree

Environment and Society Faculty Publications

Archaeologists are using spatial data in increasingly sophisticated analyses and invoking more explicit considerations of space in their interpretations. Geographic information systems (GIS) have become standard technology for professional archaeologists in the collection and management of spatial data. Many calls have been made to develop and adapt digital geospatial technologies for interpretation and understanding past social dynamics, but this has been limited to some extent by the static nature of map-oriented GIS approaches. Here, we illustrate how coupling GIS with agent-based modeling (ABM) can assist with more dynamic explorations of past uses of space and geospatial phenomena.

Outreach In Archaeology With Agent-Based Modeling: Part 3 Of 3, Stefani Crabtree, Kathryn Harris, Benjamin Davies, Iza Romanowska

Environment and Society Faculty Publications

A major challenge facing archaeologists is communicating our research to the public. Thankfully, new computational tools have enabled the testing and visualization of complex ideas in an easily packageable format. In this article we illustrate not only how agent-based modeling provides a platform for communicating complex ideas, but also how these game-like computer models can be explored and manipulated by members of the public therefore increasing their engagement in archaeological explanations. We suggest that these new digital tools serve as an excellent aid for education on the importance of archaeological sites and artifacts. To illustrate the above we walk the …

Elemental And Oxidized Mercury In Ambient Air At Rocky Flats, Colorado, Seth Lyman, Lynne Gratz

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This is a dataset of elemental and oxidized mercury in the ambient atmosphere at latitude 39.912799 and longitude -105.188587. This is the locations of the Rocky Flats North air quality monitoring station, operated by the Colorado Department of Public Health and Environment. We collected these measurements using a dual-channel atmospheric mercury speciation instrument.

Pmc Turbo: Studying Gravity Wave And Instability Dynamics In The Summer Mesosphere Using Polar Mesospheric Cloud Imaging And Profiling From A Stratospheric Balloon, David C. Fritts, Amber D. Miller, C. Bjorn Kjellstrand, Christopher Geach, Bifford P. Williams, Bernd Kaifler, Natalie Kaifler, Glenn Jones, Markus Rapp, Michele Limon, Jason Reimuller, Ling Wang, Shaul Hanany, Sonja Gisinger, Yucheng Zhao, Gunter Stober, Cora E. Randall

All Physics Faculty Publications

The Polar Mesospheric Cloud Turbulence (PMC Turbo) experiment was designed to observe and quantify the dynamics of small‐scale gravity waves (GWs) and instabilities leading to turbulence in the upper mesosphere during polar summer using instruments aboard a stratospheric balloon. The PMC Turbo scientific payload comprised seven high‐resolution cameras and a Rayleigh lidar. Overlapping wide and narrow camera field of views from the balloon altitude of ~38 km enabled resolution of features extending from ~20 m to ~100 km at the PMC layer altitude of ~82 km. The Rayleigh lidar provided profiles of temperature below the PMC altitudes and of the …

The Long‐Term Trends Of Nocturnal Mesopause Temperature And Altitude Revealed By Na Lidar Observations Between 1990 And 2018 At Midlatitude, Tao Yuan, Stanley C. Solomon, Chiao -Y. She, D. A. Krueger, Han-Li Liu

All Physics Faculty Publications

The mesopause, a boundary between mesosphere and thermosphere with the coldest atmospheric temperature, is formed mainly by the combining effects of radiative cooling of CO2, and the vertical adiabatic flow in the upper atmosphere. A continuous multidecade (1990‐2018) nocturnal temperature data base of an advanced Na lidar, obtained at Fort Collins, CO (41°N, 105°W), and at Logan, UT (42°N, 112°W), provides an unprecedented opportunity to study the long‐term variations of this important atmospheric boundary. In this study, we categorize the lidar‐observed mesopause into two categories: the “high mesopause” (HM) above 97 km during nonsummer months, mainly formed through the radiative …

Climatology And Change Of Extreme Precipitation Events In Taiwan Based On Weather Types, Yi-Chao Wu, Shih-Yu (Simon) Wang, Yi-Chiang Yu, Chu-Ying Kung, An-Hsiang Wang, Sebastian A. Los, Wan-Ru Huang

Plants, Soils, and Climate Faculty Publications

Taiwan's most significant natural hazards are caused by hydrological extremes resulting from excessive precipitation. The threat of extreme precipitation is posed by several different types of weather patterns that affect Taiwan. This study examined the bi‐decadal changes in rainfall by defining an extreme precipitation occurrence (EPO) for a range of event durations from 1 to 24 hr. Three major weather types affecting EPO in Taiwan were identified from 1993 to 2015: the front type consisting of either a frontal zone or convective systems developing with an apparent Meiyu cloudband, diurnal rainfall events when no apparent synoptic features are present, and …

Electron Yield Measurements Of Multilayer Conductive Materials, Gregory Wilson, Matthew Robertson, Jordan Lee, Jr Dennison

Conference Proceedings

As energetic electrons interact with the surface of materials, they impart energy throughout the material. If the energy exchange is near the surface, secondary electrons within the material can be excited and emitted. It is also possible for the incident primary electron to undergo a quasi-elastic collision within the material, wherein the electron is backscattered and emitted from the surface. As the backscattered electron is leaving the material, it can continue to impart energy to the material, potentially exciting more secondary electrons as it approaches the surface on the way back out.

This process of imparting energy and charge to …

Suppresion Of Electron Yield With Carbon Nanotube Forests: A Case Study, Brian Wood, Jordan Lee, Gregory Wilson, T.-C. Shen, Jr Dennison

Conference Proceedings

Electron emission of carbon nanotube (CNT) forests grown on silicon substrates was measured to investigate possible electron yield suppression due to the composition and morphology of CNT forests. CNT forests are vertically-oriented tubular formations of graphitic carbon grown on a substrate; these have been widely investigated for their extreme properties in optical, electrical, and mechanical aspects of physics and material sciences. CNT coatings are good candidates for yield reduction, in analogy with the near-ideal blackbody optical properties of CNT forests. Carbon with its low atomic number has an inherent low yield due to its low density of bulk electrons. Furthermore, …

Strategies For Determining Electron Yield Material Parameters For Spacecraft Charge Modeling, Phil Lundgreen, Jr Dennison

Conference Proceedings

Modeling of space plasma environment-induced anomalies requires knowledge of:

• Environment and impinging fluxes during spacecraft orbits, which are mission specific and can be incorporated through environmental models and databases.
• Satellite geometry and orientation in the space environment, accomplished through such charging codes as NASCAP-2K, SPENVIS, or MUSCAT.
• Materials used in spacecraft construction, from the specific spacecraft design.
• Relevant materials properties characterizing the interaction of the materials with the environment and how these properties may change with exposure to the space environment.

A reliable, comprehensive database of spacecraft materials and the characterization of those materials is being created in the form …