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Data From: Dibridged, Monobridged, Vinylidene-Like, And Linear Structures For The Alkaline Earth Dihydrides Be2h2, Mg2h2, Ca2h2, Sr2h2, And Ba2h2. Proposals For Observations, Alexander I. Boldyrev, Nikolay Tkachenko

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This research reports a search for peculiar monobridged structures of the E2H2 molecules (E = Be, Mg, Ca, Sr, Ba). For Be2H2 and Mg2H2, the monobridged geometry is not an equilibrium but rather a transition state between the vinylidene-like structure and the global minimum HE–EH linear geometry. However, for Ca2H2, Sr2H2, and Ba2H2, this situation changes significantly; the linear structure is no longer the global minimum but lies higher in energy than two other equilibria, the dibridged and monobridged structures. The planar dibridged structures of both Sr2H2 and Ba2H2 should be observable via IR spectroscopy. Although the remarkable monobridged structures …

Data For: Record Low Ionization Potentials Of Alkali Metal Complexes With Crown Ethers And Cryptands, Alexander I. Boldyrev, Nikolay Tkachenko

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Electronic properties of series of alkali metals complexes with crown ethers and cryptands were studied via DFT hybrid functionals. For [M([2.2.2]crypt)] (M=Li, Na, K) extremely low (1.70–1.52 eV) adiabatic ionization potentials were found. Such low values of ionization energies are significantly lower than those of alkali metal atoms. Thus, the investigated complexes can be defined as superalkalis. As a result, our investigation opens up new directions in the designing of chemical species with record low ionization potentials and extends the explanation of the ability of the cryptates and alkali crown ether complexes to stabilize multiple charged Zintl ions.

Data From: Structure And Bonding In [Sb@In8sb12]3− And [Sb@In8sb12]5−, Alexander I. Boldyrev, Nikolay Tkachenko

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We report the characterization of the compound [K([2.2.2]crypt)]4[In8Sb13], which proves to contain a 1:1 mixture of [Sb@In8Sb12]3− and [Sb@In8Sb12]5−. The tri-anion displays perfect Th symmetry, the first completely inorganic molecule to do so, and contains eight equivalent In3+ centers in a cube. The gas-phase potential energy surface of the penta-anion has eight equivalent minima where the extra pair of electrons is localized on one In+ center, and these minima are linked by low-lying transition states where the electron pair is delocalized over two adjacent centers. The best fit to the electron density is obtained from a model where the structure …

Data From: All-Metal Σ-Antiaromaticity In Dimeric Cluster Anion {[Cuge9mes]2}4−, Alexander I. Boldyrev, Nikolay Tkachenko

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In this work, we report a dimeric cluster anion, {[CuGe9Mes]2}4−, which was isolated as the [K(2,2,2-crypt)]+ salt and characterized by using single-crystal X-ray diffraction and ESI mass spectroscopy. The title cluster represents the first locally σ-antiaromatic compound in the solid state, as well as the first heteroatomic antiaromatic compound.

Data From: Σ-Aromaticity-Induced Stabilization Of Heterometallic Supertetrahedral Clusters [Zn6ge16]4− And [Cd6ge16]4−, Alexander I. Boldyrev, Nikolay Tkachenko

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In this work, the largest heterometallic supertetrahedral clusters, [Zn6Ge16]4− and [Cd6Ge16]4−, were directly self-assembled through highly-charged [Ge4]4− units and transition metal cations, in which 3-center–2-electron σ bonding in Ge2Zn or Ge2Cd triangles plays a vital role in the stabilization of the whole structure. The cluster structures have an open framework with a large central cavity of diameter 4.6 Å for Zn and 5.0 Å for Cd, respectively. Time-dependent HRESI-MS spectra show that the larger clusters grow from smaller components with a single [Ge4]4− and ZnMes2 units. Calculations performed at the DFT level indicate a very large HOMO–LUMO energy gap in …

Transport-Based Pattern Recognition Versus Deep Neural Networks In Underwater Oam Communications, Patrick L. Neary, Jonathan M. Nichols, Abbie T. Watnik, K. Peter Judd, Gustavo K. Rohde, James R. Lindle, Nicholas S. Flann

Space Dynamics Laboratory Publications

Comparisons between machine learning and optimal transport-based approaches in classifying images are made in underwater orbital angular momentum (OAM) communications. A model is derived that justifies optimal transport for use in attenuated water environments. OAM pattern demultiplexing is performed using optimal transport and deep neural networks and compared to each other. Additionally, some of the complications introduced by signal attenuation are highlighted. The Radon cumulative distribution transform (R-CDT) is applied to OAM patterns to transform them to a linear subspace. The original OAM images and the R-CDT transformed patterns are used in several classification algorithms, and results are compared. The …

Fruits, Frugivores, And The Evolution Of Phytochemical Diversity, Susan R. Whitehead, Gerald F. Schneider, Ray Dybzinski, Annika S. Nelson, Mariana Gelambi, Elsa Jos, Noelle G. Beckman

Biology Faculty Publications

Plants produce an enormous diversity of secondary metabolites, but the evolutionary mechanisms that maintain this diversity are still unclear. The interaction diversity hypothesis suggests that complex chemical phenotypes are maintained because different metabolites benefit plants in different pairwise interactions with a diversity of other organisms. In this synthesis, we extend the interaction diversity hypothesis to consider that fruits, as potential hotspots of interactions with both antagonists and mutualists, are likely important incubators of phytochemical diversity. We provide a case study focused on the Neotropical shrub Piper reticulatum that demonstrates: 1) secondary metabolites in fruits have complex and cascading effects for …

Chapter 12- Conducting Guided, Virtual Homework Sessions To Support Student Success During Covid Campus Closures, Rebecca Campbell, Kevin Kelly

Resilient Pedagogy

College students have long used community-based practices such as study halls, review sessions, study groups, homework buddies, and the like as academic strategies to support their learning (Hogan, 1999; Madland & Richards, 2019; Thalluri et al., 2014). With increased access to online conferencing capabilities, working in community has been adapted by faculty who have used the technology to participate in virtual write-on-sites, writing retreats and writing sprints. Thus, it is no surprise that both faculty and learning centers saw the potential for creating virtual spaces for students to work together.

Chapter 8- Creating Adaptable Courses: A Course Design Approach That Accommodates Flexible Delivery, Kosta Popovic, Eric M. Reyes, Jennifer B. O'Connor, Kay C. Dee, Ella Ingram

Resilient Pedagogy

In early 2020, educators and students around the world endured lapses in quality of educational experiences due to the disruption caused by COVID-19. In return for these lapses, students continued their programs of study within previously established timelines, and educators balanced helping students achieve learning objectives while keeping a manageable workload. Moving forward, students will expect educators and their institutions to deliver high-quality education when disruptions occur, like natural disasters, facilities emergencies, or supply chain disturbances. This expectation will extend to all modes of delivery. We assert that training educators to build adaptable courses that provide them and their students …

A Practical Guide To Selecting Models For Exploration, Inference, And Prediction In Ecology, Andrew T. Trednnick, Giles Hooker, Stephen P. Ellner, Peter B. Adler

Wildland Resources Faculty Publications

Selecting among competing statistical models is a core challenge in science. However, the many possible approaches and techniques for model selection, and the conflicting recommendations for their use, can be confusing. We contend that much confusion surrounding statistical model selection results from failing to first clearly specify the purpose of the analysis. We argue that there are three distinct goals for statistical modeling in ecology: data exploration, inference, and prediction. Once the modeling goal is clearly articulated, an appropriate model selection procedure is easier to identify. We review model selection approaches and highlight their strengths and weaknesses relative to each …

Examining The Influence Of Instructor Interventions On Group Collaboration, Luettamae Lawrence, Taylor Tucker, Emma Mercier

Instructional Technology and Learning Sciences Faculty Publications

Collaborative problem solving is often used in STEM higher education courses to support conceptual knowledge and teamwork. However, course teaching assistants (TAs) often lack the collaborative pedagogical knowledge necessary to orchestrate this form of learning. In this paper, we examine TAs’ orchestration strategies and technology used to understand how these factors influence groups’ collaboration. Contributions from this paper describe the interplay among technology, strategies, and groups’ collaboration toward understanding how to support collaboration in these courses.

Towards Bringing Human-Centered Design To K-12 And Post-Secondary Education, Saadeddine Shehab, Mike Tissenbaum, Luettamae Lawrence, Daniel Rees Lewis, Matthew Easterday, Spencer Carlson, Adam Royalty, Helen Chen, Sheppard Sheri, Shelley Goldman, Annie Camey Kuo, Kimiko Lange, Melissa Mesinas, Rose K. Pozos, Dhvani Toprani, Mona Alqahtani, Yu Xia, Marcela Borge, Keith Sawyer

Instructional Technology and Learning Sciences Faculty Publications

Human-Centered Design (HCD) is a growing field that has the potential to positively impact students’ learning. A general consensus on the terms, practices, scaffolds, and assessments of HCD can foster its effective implementation in K-12 and post-secondary education. This session brings together researchers whose work is focused on implementing HCD across K-16 classrooms. It aims to develop a coherent definition of HCD, its methods, practices, and assessments, to help frame the field and reduce ambiguity at a critical time in its broader adoption.

Range-Wide Declines Of Northern Spotted Owl Populations In The Pacific Northwest: A Meta-Analysis, Alan B. Franklin, Katie M. Dugger, Damon B. Lesmeister, Raymond J. Davis, J. David Wiens, Gary C. White, James D. Nichols, James E. Hines, Charles B. Yackulic, Carl J. Schwarz, Steven H. Ackers, L. Steven Andrews, Larissa L. Bailey, Robin Bown, Mary M. Conner, Et Al.

Wildland Resources Faculty Publications

The northern spotted owl (Strix occidentalis caurina) inhabits older coniferous forests in the Pacific Northwest and has been at the center of forest management issues in this region. The immediate threats to this federally listed species include habitat loss and competition with barred owls (Strix varia), which invaded from eastern North America. We conducted a prospective meta-analysis to assess population trends and factors affecting those trends in northern spotted owls using 26 years of survey and capture-recapture data from 11 study areas across the owls' geographic range to analyze demographic traits, rates of population change, and …

Digital Appendix Of Masters Thesis "Constraining Deformation Mechanisms Of Damage Zones: A Case Study Of The Shallow San Andreas Fault At Elizabeth Lake, Southern California, James P. Evans, Caroline Studnicky

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We performed macroscopic, optical petrographic, scanning electron microscopy, and geochemical analyses on rock core acquired across the San Andreas Fault at Elizabeth Lake, California, in order to understand the distribution and accommodation of fault-related slip and energy within the shallow damage zone of this continental scale strike-slip fault. We characterized the deformation structures, alteration textures, and elemental variabilities to constrain the properties of the uppermost ~2 km fault-related damage zone at this site. We identified evidence for coseismic slip in the form of pulverized rocks, injection veins, clay-clast aggregates, and pseudotachylyte, and aseismic slip through calcite twins, dilatant vein fills, …

Electron Yield Decay Curves For Analysis Of Sample Charging And Neutralization, Matthew Robertson

Utah Space Grant Consortium

Excess charge on a material will affect the electron yield of the material. Electron yield is an attribute of materials which describe how the material behaves when irradiated with electrons. It is the ratio of the number of electrons going into the material over the number of electrons leaving the material. Understanding how a sample charges is important in both how it affects the electron yield and how it can be neutralized.

Comparing P-11b To D-3he Fusion For Direct Drive Fusion Rockets, Christopher Hooper

Utah Space Grant Consortium

Direct Fusion Drive (DFD) is a theoretical configuration that uses a magnetically confined fusing plasma to provide thrust for a rocket. In the words of the original authors, Princeton Satellite Systems (PSS) and Razinet al., it is “...a compact, anuetronic fusion engine [which] will enable more challenging exploration missions in the solar system.” DFD is proposed as a theoretical alternative to chemical and ion propulsion rockets – as seen in Table 1, it has clear advantages over both in exhaust velocity (specific impulse) and mass ratio, and a large advantage over ion propulsion in thrust and thrust-to-weight ratio. Despite being …

Air Quality Measurements In Ephraim, Ut, Alex Allred

Utah Space Grant Consortium

Standard Air Quality indicators: NO, NOx, SO2, CO, O3 and PM2.5 were measured in Ephraim, Sanpete county, Utah from Dec 16, 2020 -Mar 6, 2021. The Air quailty monitoring station was installed in December 2020 and is currently operating. Ephraim is located in a high mountain valley at 5541 feet elevation. Events of interest were evaluated using back trajectories and wind rose analysis.

Evaluating Gallium As A Catalyst For Silicon Nanodot Synthesis, Rylan Woods

Utah Space Grant Consortium

Silicon nanostructures, such as silicon nanowires and silicon nanodots, exhibit notably different thermoelectric, electric, and optical properties from bulk silicon. These nanostructures are ideal for utilization in a variety of electronic and optical devices ranging from batteries to solar panels. While various synthesis methods and catalysts exist for making silicon nanowires, gallium exhibits unique nanowire shapes compared to other catalyst metals such as gold or silver. This experiment uses gallium as a catalyst to form silicon nanostructures onoriented silicon substrate at temperatures of 0, 850, and 900ºC. Analyzing dosed samples via SEM resulted in several samples showing possible evidence of …

A Preliminary Approach To Select An Origami Source Pattern For Deployable Space Arrays, Diana S. Bolanos

Utah Space Grant Consortium

This paper presents a systematic approach for selecting an origami pattern for deployable space array applications. A wide variety of origami patterns exist, thereby introducing a daunting task to decide on which pattern is most suitable for the application at hand. Similarly, different space missions present varying requirements. The focus of this paper is to provide aerospace engineers and designers with a framework for identifying optimal origami source models for space array applications.

A Study Of Oxidation In Thin-Film Uranium-Niobium Alloys, Logan C. Page

Utah Space Grant Consortium

Uranium, a nuclear fuel material, can oxidize and degrade in reactor conditions. Previous studies have shown oxidation resistance in a uranium-niobium alloy, U-6Nb (six weight percent niobium in uranium). The nature of the oxides that form on sputtered U-6Nb thin films after long exposure to air was previously explored using neutron diffraction at Los Alamos National Laboratory. In the present work, we deposited thin films of uranium-niobium alloys for oxidation studies. We used ellipsometry to quantify the oxide growth over time as a function of niobium content. We found that the oxide thickness increases linearly with the logarithmic of time. …

Comparison Of Rayleigh-Scatter Lidar Temperature Climatologies In The Mesosphere And Lower Thermosphere Between The Traditional Reduction Method And The New Optimal Estimation Method, Jonathan Price

Utah Space Grant Consortium

An optimal estimation method (OEM) was used to obtain all-night temperature profiles from Rayleigh-scatter lidar (RSL) observations obtained by the original and updated lidar systems at Utah State University (USU). These data were used to produce annual climatologies of temperatures above USU. The climatology of temperatures from the original lidar, which operated from late 1993 through 2004, was compared with the climatology produced using the widely used Hauchecorne-Chanin method (HC). This comparison highlights the similarities at lower altitudes and differences, which start between 70 km and 80 km and extend to the top altitudes with the OEM temperatures warmer on …

Seeking The Origin Of Electromagnetic Signatures Of Black Holes, Alexandra B. Chanson

Utah Space Grant Consortium

Relativistic-jet formation in astrophysical black holes lacks a rigorously understood mechanism of energy extraction in the high-energy regime although, in recent years, progress has been made in extending the non-linear equations of Force-Free Electrodynamics (FFE) into the high-spin regime. In particular, M. J. Rodriguez and A. Strominger were able to show, using the Near Horizon Extremal Kerr spacetime, that the near horizon FFE solutions have an additional scaling symmetry which allows the construction of a pseudo-analytical infinite tower of solutions. These families of solutions stand in stark contrast to the relatively few full Kerr solutions found analytically: this tension can …

Monitoring Acute Kidney Injury Risk With Urine Oxygen Partial Pressure, Lars Lofgren

Utah Space Grant Consortium

Acute kidney injury (AKI) is a common complication associated with cardiac surgery. AKI is associated with increased hospital costs, hospital length of stay (LOS), and mortality risk. The current diagnostic criteria rely on serum creatinine measurements and urine output data. Serum creatinine is not renal specific. It is known that there are factors other than renal injury that influence serum creatine concentrations. Serum creatinine levels are measured as concentrations which means large changes in fluid balance may alter the serum creatinine concentration. Urine output is not a reliable measurement of renal injury, either. During surgery it is common to administer …

Meta-Analysis Reveals Different Competition Effects On Tree Growth Resistance And Resilience To Drought, Daniele Castagneri, Giorgio Vacchiano, Andrew Hacket-Pain, R. Justin Derose, Tamir Klein, Alessandra Bottero

Wildland Resources Faculty Publications

Drought will increasingly threaten forest ecosystems worldwide. Understanding how competition influences tree growth response to drought is essential for forest management aiming at climate change adaptation. However, published results from individual case studies are heterogeneous and sometimes contradictory. We reviewed 166 cases from the peer-reviewed literature to assess the influence of stand-level competition on tree growth response to drought. We monitored five indicators of tree growth response: mean sensitivity (inter-annual tree ring width variability); association between inter-annual growth variability and water availability; resistance; recovery; and resilience to drought. Vote counting did not indicate a consistent effect of competition on mean …

Phase-Space Dynamics Of Runaway Electrons In Tokamaks, Gavin Held

Physics Capstone Projects

Nuclear fusion converts the rest mass energy of ions like the deuteron and triton into kinetic energy. In theory, this energy can be harvested from a thermonuclear reactor to provide power outputs on the scale of 500 MW. High temperatures are needed for significant fusion to occur, hence the tokamak (a modern fusion confinement device) employs strong magnetic fields to keep the ionized gas (plasma) away from the tokamak wall. However, a problem that occasionally arises in a tokamak is that during a disruption an inductive electric field is created which can accelerate electrons to relativistic speeds (these electrons are …

Standard Non-Uniform Noise Dataset, Andres Imperial, John M. Edwards

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Fixed Pattern Noise Non-Uniformity Correction through K-Means Clustering

Fixed pattern noise removal from imagery by software correction is a practical approach compared to a physical hardware correction because it allows for correction post-capture of the imagery. Fixed pattern noise presents a unique challenge for de-noising techniques as the noise does not present itself where large number statistics are effective. Traditional noise removal techniques such as blurring or despeckling produce poor correction results because of a lack of noise identification. Other correction methods developed for fixed pattern noise can often present another problem of misidentification of noise. This problem can result …

The Effects Of Materials And Profiles Of Gratings On Diffraction Spectra, Brock Halling

Physics Capstone Projects

Diffraction patterns can be made either by transmitting or reflecting light from a grating which is an array of parallel lines (rulings) with a fixed periodicity. Elementary optical treatment of diffraction gratings only describes diffraction angles as a function of periodicity of the grating. However, we have observed that the profile and materials of the grating do affect the diffraction pattern. In this study, I investigated the correlation between the grating profiles obtained by scanning electron microscopy and the materials of the grating (polymer and silicon dioxide) and the spectra as a function of the diffraction angle. An optical spectrometer …

Developing Electron Beam Lithography At Nanoscale Device Laboratory, Din Pašić

Physics Capstone Projects

At the Nanoscale Device Laboratory, we can routinely create patterns with a minimum linewidth of 800 nm using photolithography. However, to create photonic devices, the pattern size must be smaller than the wavelength of visible light (400 to 800 nm). Dedicated electron beam writers can achieve a sub-10 nm linewidth, but this system is beyond our reach. In this project, we plan to use a Nanometer Pattern Generation System connected to a Quanta 650 scanning electron microscope to perform e-beam lithography. After setting up a computer to run the NPGS system, and establishing communications with the SEM, we experimented with …

Comparisons Of Mesospheric Temperatures Between 70 And 110 Km: Usu Lidar, Nasa's Timed Satellite, And The Msis2 Empirical Model, David M. Collins

Physics Capstone Projects

Earth’s atmosphere can be characterized by its temperature structure, dividing the atmosphere into natural discrete regions. The mesosphere (50 to ~100 km) has been the least studied. Rayleigh-scatter lidars (RSL) and rockets can obtain local, high-resolution measurements above one spot, while satellites looking almost horizontally obtain global measurements. These two methods of measuring atmospheric conditions are compared using the USU RSL and the SABER instrument on NASA’s TIMED satellite. These measurements were graphed to show four sets of temperatures from several sources in the atmospheric region 70 km to 110 km above USU. The results show similar temperatures for many …

Utah State University Commencement, 2021 – Kaysville Campus, Utah State University

Commencement Programs

2021 Commencement Ceremony for the Kaysville Campus of Utah State University.