Physical Sciences and Mathematics Commons^™

Biodiverse Cities: The Nursery Industry, Homeowners, And Neighborhood Differences Drive Urban Tree Composition, Meghan L. Avolio, Diane E. Pataki, Tara L. E. Trammell, Joanna Endter-Wada

Environment and Society Faculty Publications

In arid and semiarid regions, where few if any trees are native, city trees are largely human planted. Societal factors such as resident preferences for tree traits, nursery offerings, and neighborhood characteristics are potentially key drivers of urban tree community composition and diversity, however, they remain critically understudied. We investigated patterns of urban tree structure in residential neighborhoods of the Salt Lake Valley, Utah, combining biological variables, such as neighborhood and plant nursery tree species and trait composition, and sociological data comprised of resident surveys and U.S. Census data. We sampled nine neighborhoods that varied in household income and age …

Estimating Discharge In Low-Order Rivers With High-Resolution Aerial Imagery, Tyler V. King, Bethany T. Neilson, Mitchell T. Rasmussen

Publications

Remote sensing of river discharge promises to augment in situ gauging stations, but the majority of research in this field focuses on large rivers (>50 m wide). We present a method for estimating volumetric river discharge in low-order (wide) rivers from remotely sensed data by coupling high-resolution imagery with one-dimensional hydraulic modeling at so-called virtual gauging stations. These locations were identified as locations where the river contracted under low flows, exposing a substantial portion of the river bed. Topography of the exposed river bed was photogrammetrically extracted from high-resolution aerial imagery while the geometry of the remaining inundated portion …

Pi Tetrel Bonds, And Their Influence On Hydrogen Bonds And Proton Transfers, Yuanxin Wei, Qingzhong Li, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The positive region that lies above the plane of F2TO (T=C and Si) interacts with malondialdehyde (MDA), which contains an intramolecular H‐bond. The T atom of F2TO can lie either in the MDA molecular plane, forming a T⋅⋅⋅O tetrel bond, or F2TO can stack directly above MDA in a parallel arrangement. The former structure is more stable than the latter, and in either case, F2SiO engages in a much stronger interaction than does F2CO, reaching nearly 200 kJ mol−1. The π‐tetrel bond strengthens/weakens the MDA H‐bond when the bond is formed to the hydroxyl/carbonyl group of MDA, and causes an …

Monthly Paleostreamflow Reconstruction From Annual Tree-Ring Chronologies, James H. Stagge, David E. Rosenberg, R. J. Derose, Tammy M. Rittenour

Publications

Paleoclimate reconstructions are increasingly used to characterize annual climate variability prior to the instrumental record, to improve estimates of climate extremes, and to provide a baseline for climate-change projections. To date, paleoclimate records have seen limited engineering use to estimate hydrologic risks because water systems models and managers usually require streamflow input at the monthly scale. This study explores the hypothesis that monthly streamflows can be adequately modeled by statistically decomposing annual flow reconstructions. To test this hypothesis, a multiple linear regression model for monthly streamflow reconstruction is presented that expands the set of predictors to include annual streamflow reconstructions, …

Fully Discrete Second-Order Linear Schemes For Hydrodynamic Phase Field Models Of Binary Viscous Fluid Flows With Variable Densities, Yuezheng Gong, Jia Zhao, Xiaogang Yang, Qi Wang

Mathematics and Statistics Faculty Publications

We develop spatial-temporally second-order, energy stable numerical schemes for two classes of hydrodynamic phase field models of binary viscous fluid mixtures of different densities. One is quasi-incompressible while the other is incompressible. We introduce a novel energy quadratization technique to arrive at fully discrete linear schemes, where in each time step only a linear system needs to be solved. These schemes are then shown to be unconditionally energy stable rigorously subject to periodic boundary conditions so that a large time step is plausible. Both spatial and temporal mesh refinements are conducted to illustrate the second-order accuracy of the schemes. The …

Animal Movement Affectsinterpretation Of Occupancy Models From Camera Trap Surveys Of Unmarked Animals, Eric W. Neilson, Tal Avgar, A. Cole Burton, Kate Broadley, Stan Boutin

Wildland Resources Faculty Publications

Occupancy models are increasingly applied to data from wildlife camera-trap (CT) surveys to estimate distribution, habitat use, or relative abundance of unmarked animals. Fundamental to the occupancy modeling framework is the temporal pattern of detections at camera stations, which is influenced by animal population density and the speed and scale of animal movement. How these factors interact with CT sampling designs to affect the interpretation of occupancy parameter estimates is unclear. We developed a simple yet ecologically relevant animal movement simulation to create CT detections for animal populations varying in movement rate, home range area, and population density. We also …

Bonding And Bridging Forms Of Social Capital In Wildlife Tourism Microentrepreneurship: An Application Of Social Network Analysis, K. C. Birendra, Duarte B. Morals, Erin Seekamp, Jordan Smith, M. Nils Peterson

Environment and Society Faculty Publications

Tourism has been recognized as an important economic sector, requiring a high degree of involvement from the entrepreneurial sector to diversify tourism products and services to meet increasing demand. Tourism is often considered a tool for economic development and a strategy to improve the livelihoods of rural citizens. Specifically, nature-based tourism, such as wildlife tourism, is growing faster than tourism in general, providing a myriad of opportunities for small-scale entrepreneurial engagement. However, several obstacles exist for these small-scale tourism enterprises, such as a lack of social capital. This study examined a network of wildlife tourism microentrepreneurs for bonding and bridging …

Time-Evolved Constant Voltage Conductivity Measurements Of Common Spaceborne Polymeric Materials, Brian Wood, David King, Jr Dennison

Presentations

No abstract provided.

Survival Rates Indicate That Correlations Between Community-Weighted Mean Traits And Environments Can Be Unreliable Estimates Of The Adaptive Value Of Traits, Daniel C. Laughlin, Robert T. Strahan, Peter B. Adler, Margaret M. Moore

Wildland Resources Faculty Publications

Correlations between community-weighted mean (CWM) traits and environmental gradients are often assumed to quantify the adaptive value of traits. We tested this assumption by comparing these correlations with models of survival probability using 46 perennial species from long-term permanent plots in pine forests of Arizona. Survival was modeled as a function of trait-by-environment interactions, plant size, climatic variation, and neighborhood competition. The effect of traits on survival depended on the environmental conditions, but the two statistical approaches were inconsistent. For example, CWM specific leaf area (SLA) and soil fertility were uncorrelated. However, survival was highest for species with low SLA …

Community-Level Plant–Soil Feedbacks Explain Landscape Distribution Of Native And Non-Native Plants, Andrew Kulmatiski

Wildland Resources Faculty Publications

Plant–soil feedbacks (PSFs) have gained attention for their potential role in explaining plant growth and invasion. While promising, most PSF research has measured plant monoculture growth on different soils in short-term, greenhouse experiments. Here, five soil types were conditioned by growing one native species, three non-native species, or a mixed plant community in different plots in a common-garden experiment. After 4 years, plants were removed and one native and one non-native plant community were planted into replicate plots of each soil type. After three additional years, the percentage cover of each of the three target species in each community was …

Observations Of The Breakdown Of Mountain Waves Over The Andes Lidar Observatory At Cerro Pachon On 8/9 July 2012, James Hecht, Dave Fritts, L. Wang, L. J. Gelinas, R. J. Rudy, Richard L. Walterscheid, Michael J. Taylor, Pierre-Dominique Pautet, Steven Smith, S. J. Franke

All Physics Faculty Publications

Although mountain waves (MWs) are thought to be a ubiquitous feature of the wintertime southern Andes stratosphere, it was not known whether these waves propagated up to the mesopause region until Smith et al. (2009) confirmed their presence via airglow observations. The new Andes Lidar Observatory at Cerro Pachon in Chile provided the opportunity for a further study of these waves. Since MWs have near-zero phase speed, and zero wind lines often occur in the winter upper mesosphere (80 to 100 km altitude) region due to the reversal of the zonal mean and tidal wind, MW breakdown may routinely occur …

Exploring Wave-Wave Interactions In A General Circulation Model, Virginia Nystrom, Federico Gasperini, Jeffrey M. Forbes, Maura E. Hagan

All Physics Faculty Publications

Nonlinear interactions involving Kelvin waves with (periods, zonal wave numbers) = (3.7d, s =− 1) (UFKW1) and = (2.4d, s =− 1) (UFKW2) and s = 0 and s = 1 quasi 9 day waves (Q9DW) with diurnal tides DW1, DW2, DW3, DE2, and DE3 are explored within a National Center for Atmospheric Research (NCAR) thermosphere-ionosphere-mesosphere electrodynamics general circulation model (TIME-GCM) simulation driven at its ∼30 km lower boundary by interpolated 3-hourly output from Modern-Era Retrospective Analysis for Research and Applications (MERRA). The existence of nonlinear wave-wave interactions between the above primary waves is determined by the presence of secondary …

Spectrum Universality Properties Of Holographic Chern-Simons Theories, Yi Pang, Junchen Rong, Oscar J. Varela

All Physics Faculty Publications

We give a master formula for the sin-2 spectrum of a class of three-dimensional Chern-Simons theories at large N, with flavour group containing SU(3), that arise as infrared fixed points of the D2-brane worldvolume field theory and have AdS₄ duals in massive type IIA supergravtiy. We use this formula to compute the spin-2 spectrum of the individual theories discuss its supermultiplet structure and, for an N = 2 theory in this class, the spectrum of protected operators with spin 2. We also show that the trace of the Kaluza-Klein graviton mass matrix on the dual AdS₄ solutions …

Sensor Design For In-Flight Testing Of Small-Satellite Thruster, Alex Souvall

Senior Theses and Projects

No abstract provided.

Aerogen Bonds Formed Between Aeof2 (Ae = Kr, Xe) And Diaziness: Comparisons Between Σ-Hole And Π-Hole Complexes, Wiktor Zierkiewicz, Mariusz Michalczyk, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The interaction between KrOF2 or XeOF2 and the 1,2, 1,3, and 1,4 diazines is characterized chiefly by a Kr/Xe···N aerogen bond, as deduced from ab initio calculations. The most stable dimers take advantage of the σ-hole on the aerogen atom, wherein the two molecules lie in the same plane. The interaction is quite strong, as much as 18 kcal mol-1. A second class of dimer geometry utilizes the π-hole above the aerogen atom in an approximate perpendicular arrangement of the two monomers; these structures are not as strongly bound: 6-8 kcal mol-1. Both sorts of dimers contain auxiliary CH···F H-bonds …

Computational Assessment Of An Elusive Aromatic N3p3 Molecule, Alyona A. Starikova, Natalia M. Boldyreva, Ruslan M. Minyaev, Alexander I. Boldyrev, Vladimir I. Minkin

Chemistry and Biochemistry Faculty Publications

We computationally proved that the planar aromatic hexagonal isomer N₃P₃ with the alteration of N and P is the second most stable structure for the N₃P₃ stoichiometry. We found that the aromatic isomer has high barriers for transition into the global minimum structure or into the three isolated NP molecules, making this structure kinetically stable. We showed that the sandwich N₃P₃CrN₃P₃ molecule corresponds to a minimum on the potential energy surface; thus, the aromatic N₃P₃ molecule has a potential to be a new ligand …

Unexpected Occurrence Of Mesospheric Frontal Gravity Wave Events Over South Pole (90°S), Pierre-Dominique Pautet, Michael J. Taylor, J. B. Snively, Christina Solorio

Publications

Since 2010, Utah State University has operated an infrared Advanced Mesospheric Temperature Mapper at the Amundsen–Scott South Pole station to investigate the upper atmosphere dynamics and temperature deep within the vortex. A surprising number of “frontal” gravity wave events (86) were recorded in the mesospheric OH(3,1) band intensity and rotational temperature images (typical altitude of ~87 km) during four austral winters (2012–2015). These events are gravity waves (GWs) characterized by a sharp leading wave front followed by a quasi-monochromatic wave train that grows with time. A particular subset of frontal gravity wave events has been identified in the past (Dewan …

Late History Graph, David Peak

Background

Late History graph image.

Background, 1, David Peak

Background

This course deals with the structure of matter at its extreme length scales: cosmological on the large end (on the order of 1026 m), sub-nuclear on the small (less than 10-19 m). It also deals with the now firmly established realization that the organization of matter on these two phenomenally different scales is actually intimately connected. This course is about science in its most alive and vibrant state: what we think we know about the big and small of the universe changes virtually daily. Satellite observatories and ground-based particle accelerators make what was formerly “common knowledge” obsolete at a rapid …

Background, 2, David Peak

Background

Ordinary, everyday, Galilean/Newtonian relativity

An “event” is something that happens at a point in space, at an instant in time. In physics, relativity means the rules by which two observers can compare and make sense of measurements each makes of the positions and times of the same events. In physics, an observer is not a person or an individual measuring device. Such isolated “detectors” are plagued by experimental issues of parallax, delay times, and so forth. For our purposes, an observer will always mean an infinite collection of rigidly attached, perfect sensors and microprocessors whose internal clocks are perfectly synchronized. …

History Graph, David Peak

Background

History graph image.

General Relativity, 2, David Peak

General Relativity

Newton’s law of gravitostatics is incompatible with special relativity. To see this, suppose at time t in frame O m₁ is at x₁(t) and m₂ is at x₂(t). Newton’s gravitational force law says F_{1on 2}(t) = Gm₁m₂ / [x₂(t) − x₁(t)]² and relativistic dynamics says dp₂ /dt = F_{1on 2}. Transforming to another frame Oʹ moving relative to O leads to dp′₂/dt′ = F′_{1on 2}. But what is F′_{1on 2} ? If x₁(t) and …

General Relativity, 1, David Peak

General Relativity

In special relativity, events occur in the arena of space-time which may be coordinatized differently by different observers, but which is otherwise immutable. Adding gravity to relativity provides an amazing result: space-time becomes “organic,” taking its form from the matter and energy it contains. This is Einstein’s general theory of relativity and it has the capacity to tell us about the past and future of the universe. Embedded in the history book of the cosmos are several chapters on the origins of matter. As a result, relativity + gravity unites the structures of matter on the largest and smallest scales.

General Relativity, 5, David Peak

General Relativity

No abstract provided.

General Relativity, 4, David Peak

General Relativity

Orbital motion of small test masses

The starting point for analyzing free fall trajectories in the (2-space, 1-time) Schwarzschild spacetime is Equation (3) from GR 3:

General Relativity, 3, David Peak

General Relativity

Gravity as geometry: part II

Even in a region of space-time that is so small that tidal effects cannot be detected, gravity still seems to produce curvature. The argument for this point of view starts with the recognition that, for mechanical systems, it is impossible to distinguish a frame of reference with a uniform gravitational field from a uniformly accelerating frame that has no gravity. Thus, for example, in a (small) rocket ship with no windows it is not possible to determine whether the weight one reads standing on a scale at the tail of the rocket is due to …

Inflation (Excel), David Peak

General Relativity

No abstract provided.

General Relativity, 6, David Peak

General Relativity

Modern cosmography

The “normal” matter in the universe—i.e., stuff made of protons, neutrons, and electrons— consists, approximately, of lumps floating in a dilute fog. The lumps are galaxies, clusters of 10⁷ to 10¹¹ stars bound together by gravity. In the currently observable universe, it is estimated that there are roughly 10¹¹ galaxies. The dilute fog is primarily neutral atomic hydrogen gas with some helium-4 mixed in (making up a total of 98% or more of the fog); there are also very small fractions of ²H (deuterium), ³He , and ⁷Li . The ratio …

General Relativity, 9, David Peak

General Relativity

Cosmic development

As discussed in GR 8, the cosmic scale factor a in the FLWR s-t obeys the Friedmann equation

General Relativity, 8, David Peak

General Relativity

The Cosmic Microwave Background (CMB)

As previously noted, the universe is filled with microwave radiation. The frequency spectrum of this ubiquitous radiation follows a blackbody curve, as shown to the right. (http://map.gsfc.nasa.gov/media/ContentMedia/990015b.jpg) Note that photon energy (proportional to 1/wavelength) increases to the right. You might think the curve shown is the plot of a theoretical equation, but what is shown is actual measured data taken during the flight of the COBE (Cosmic Microwave Explorer) satellite/microwave observatory in 1990. The uncertainties in the measurements are about the thickness of the curve plotted. When compared with a theoretical blackbody curve the disagreement …