Physical Sciences and Mathematics Commons^™

Seasonal Temperatures From The Upper Mesosphere To The Lower Thermosphere Obtained With The Large, Alo-Usu, Rayleigh Lidar, Vincent B. Wickwar, Leda Sox, Matthew T. Emerick, Joshua P. Herron

Posters

Observations have been made with the large, Rayleigh-scatter lidar at the Atmospheric Lidar Observatory at Utah State University (ALO-USU; 41.74° N, 111.81° W) from summer 2014 to summer 2015. During this first operational year, the lidar acquired nearly 100 nights of observations between 70 and 115 km altitude, i.e., from the upper mesosphere, through the mesopause, and into the lower thermosphere. This was possible because of the large 4.9 m2 collecting area of the mirrors and the 42 W of 532 nm emission at 30 Hz. These two factors produce a figure of merit, the power-aperture-product, of 206 Wm2, making …

Searching For Troposphere-Mesosphere Connections Using The Alo-Usu Rayleigh-Scatter Lidar, David K. Moser, Vincent B. Wickwar, Joshua P. Herron

Posters

The paucity of whole-atmosphere data introduces significant challenges that hinder the study of atmospheric couplings. The mesosphere in particular is a low-information void between the lower and upper atmosphere, which may prevent us from a complete realization of vertical interactions. The Rayleighscatter lidar at Utah State University’s Atmospheric Lidar Observatory (ALO-USU; 41.74° N, 111.81° W), operated with little interruption from 1993 to 2004, providing a valuable temporal and spatial (45 – 90 km) resource in this realm. When studied alongside a multitude of other atmospheric data sources, possible unforeseen connections or insights may result. In this study, an adaptive fit …

Reestablishing Observations Throughout The Mesosphere With The Alo-Usu Rayleigh-Scatter Lidar, Shayli Elliott, Bryant Ward, Benjamin Lovelady, Jessica Gardiner, Lucas Priskos, Matthew T. Emerick, Vincent B. Wickwar

Posters

In the last few years, the Rayleigh-scatter lidar at the Atmospheric Lidar Observatory at Utah State University (ALO-USU; 41.74° N, 111.81° W) has been upgraded to extend observations from 70 km up to 115 km. This project describes a student project to build and use a complementary Rayleigh-scatter lidar to go from 40 to 90 km, from the upper stratosphere to the upper mesosphere. At the upper end, this new lidar overlaps with the high-altitude lidar. This was done in a period of just over two months. This lidar shares the same lasers, but introduces a 44-cm mirror and a …

Obtaining Continuous Observations From The Upper Stratosphere To The Lower Thermosphere Using The Alo-Usu Rayleigh-Scatter Lidar., Jonathan L. Price, Vincent B. Wickwar, Leda Sox, Matthew T. Emerick, Joshua P. Herron, Shayli Elliott, Bryant Ward, Benjamin Lovelady

Posters

The Rayleigh-scatter lidar at the Atmospheric Lidar Observatory at Utah State University (ALO-USU; 41.74° N, 111.81° W) started observations in 1993. In 2012 the original lidar system was upgraded with an array of larger mirrors and two lasers to enable observations of the upper mesosphere and lower thermosphere from 70 km to about 115 km in altitude. (Continued refinement should provide data to above 120 km.) Recently, the original system was reconfigured [Elliott et al., 2016] to again observe the lower mesosphere between 40 km and 90 km. Initial data collected by these two parts of the Rayleigh system have …

Simultaneous, Collocated Rayleigh And Sodium Lidar Temperature Comparison, Leda Sox, Vincent B. Wickwar, Tao Yuan, Neal Criddle

Posters

There are relatively few instruments that have the capabilities to make near continuous measurements of the mesosphere-lower-thermosphere (MLT) region. Rayleigh-scatter (RS) and resonance lidars, particularly sodium (Na) resonance lidar, have been the two dominant ground-based techniques for acquiring mesosphere and MLT vertical temperature profiles, respectively, for more than two decades. With these measurements, the dynamics and long-term temperature trends of the MLT region can be studied. For the first time, we will present simultaneous, night-time averaged temperatures acquired from the same observational site, on the campus of Utah State University (USU), using these two lidar techniques. This comparison is also …

The Response Of Equatorial Electrojet, Vertical Plasma Drift, And Thermospheric Zonal Wind To Enhanced Solar Wind Input, Chao Xiong, Hermann LüHr, B. G. Fejer

All Physics Faculty Publications

In this study we used observations from the CHAMP and ROCSAT-1 satellites to investigate the solar wind effects on the equatorial electrojet (EEJ), vertical plasma drift, and thermospheric zonal wind. We show that an abrupt increase in solar wind input has a significant effect on the low-latitude ionosphere-thermosphere system, which can last for more than 24 h. The disturbance EEJ and zonal wind are mainly westward for all local times and show most prominent responses during 07–12 and 00–06 magnetic local time (MLT), respectively. The equatorial disturbance electric field is mainly eastward at night (most prominent for 00–05 MLT) and …

Nx∙∙Y Halogen Bonds. Comparison With Nh∙∙Y H-Bonds And Cx∙∙Y Halogen Bonds, Binod Nepal, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Quantum calculations examine how the NH∙∙Y H-bond compares to the equivalent NX∙∙Y halogen bond, as well as to comparable CH/CX donors. Succinimide and saccharin, and their corresponding halogen-substituted derivatives, are chosen as the prototype NH/NX donors, paired with a wide range of electron donor molecules. The NH∙∙Y H-bond is weakened if the bridging H is replaced by Cl, and strengthened by I; a Br halogen bond is roughly comparable to a H-bond. The lone pairs of the partner molecule are stronger electron donors than are π-systems. Whereas Coulombic forces represent the largest fraction of the attractive force in the H-bonds, …

Positive And Negative Gps-Tec Ionospheric Storm Effects During The Extreme Space Weather Event Of March 2015 Over The Brazilian Sector, P. R. Fagundes, F. A. Cardoso, B. G. Fejer, K. Venkatsch, B.A. G. Ribeiro, V. G. Pillat

All Physics Faculty Publications

We studied the response of the ionosphere (F region) in the Brazilian sector during extreme space weather event of 17 March 2015 using a large network of 102 GPS- total electron content (TEC) stations. It is observed that the vertical total electron content (VTEC) was severely disturbed during the storm main and recovery phases. A wavelike oscillation with three peaks was observed in the TEC diurnal variation from equator to low latitudes during the storm main phase on 17_18 March 2015. The latitudinal extent of the wavelike oscillation peaks decreased from the beginning of the main phase toward the recovery …

Solar Cycle Variability In Mean Thermospheric Composition And Temperature Induced By Atmospheric Tides, M. Jones Jr., J. M. Forbes, M. E. Hagan

All Physics Faculty Publications

In this paper we demonstrate that dissipation of upward propagating tides produces significant changes in the mean temperature of the thermosphere, ranging from +19æK at solar minimum to _15æK at solar maximum in the equatorial region. Our methodology consists of measuring the differential response of the thermosphere-ionosphere-electrodynamics general circulation model (TIE-GCM) under solar minimum and solar maximum conditions to constant tidal forcing at its 97ækm lower boundary, as specified by the observationally based Climatological Tidal Model of the Thermosphere. Diagnosis of the model reveals that these changes are mainly driven by 5.3æ_m nitric oxide (NO) cooling, which more efficiently cools …

Nitrogenase Bioelectrocatalysis: Heterogeneous Ammonia And Hydrogen Production By Mofe Protein, Ross D. Milton, Sofiene Abdellaoui, Nimesh Khadka, Dennis R. Dean, Donal Leech, Lance C. Seefeldt, Shelley D. Minteer

Chemistry and Biochemistry Faculty Publications

notrogenase is the only enzyme known to catalyze the reduction of N2 to 2NH3. In vivo, the MoFe protein component of nitrogenase is exclusively reduced by the ATP-hydrolyzing Fe protein in a series of transient association/dissociation steps that are linked to the hyderolysis of two ATP for each electron transeferred. We report MoFe protein immobilized at an electrode surface, where cobaltocene (as an electron mediator that can be observed in real time at a carbon electrode) is used to reduce the MoFe protein (independent of the Fe protein and of ATP hydrolysis) and support the bioelectrocatalytic reduction of protons to …

Segmentation And Additive Approach: A Reliable Technique To Study Noncovalent Interactions Of Large Molecules At The Surface Of Single‐Wall Carbon Nanotubes, Ana M. Torres, Steve Scheiner, Ajit K. Roy, Andrés M. Garay-Tapia, John J. Bustamante, Tapas Kar

Chemistry and Biochemistry Faculty Publications

This investigation explores a new protocol, named Segmentation and Additive approach (SAA), to study exohedral noncovalent functionalization of single-walled carbon nanotubes (SWNTs) with large molecules, such as polymers, bio-molecules etc, by segmenting the entire system into smaller units to reduce computational cost. A key criterion of the segmentation process is the preservation of the molecular structure responsible for stabilization of the entire system in smaller segments. Noncovalent interaction of linoleic acid (LA, C18H32O2), a fatty acid, at the surface of a (10,0) zigzag nanotubeis considered for test purposes. Three smaller segmented models have been created from the full (10,0)-LA system …

A Proof Of Concept Study Of Function-Based Statistical Analysis Of Fnirs Data: Syntax Comprehension In Children With Specific Language Impairment Compared To Typically-Developing Controls, Matthew D. Meng, Nicholas J. Wan, Joseph M. Baker, James Montgomery, Julia L. Evans, Ronald Gillam

Mathematics and Statistics Faculty Publications

Functional near infrared spectroscopy (fNIRS) is a neuroimaging techonology that enables investigators to indirectly monitor brain activity in vivo through relative changes in the concentration of oxygenated and deoxygenated hemoglobin. One of the key features of fNIRS is its superior temporal resolution, with dense measurements over very short periods of time (100ms increments). Unfortunately, most statistical analysis approaches in the existing literature have not fully utilized the high temporal resolution of fNIRS. For example, many analysis procedures are based on linearity assumptions that only extract partial information, thereby neglecting the overall dynamic trends in fNIRS trajectories. The main goal of …

Record Of Paleofluid Circulation In Faults Revealed By Hematite (U-Th)/He And Apatite Fission-Track Dating: An Example From Gower Peninsula Fault Fissures, Wales, Alexis K. Ault, Max Frenzel, Peter W. Reiners, Nigel H. Woodcock, Stuart N. Thomson

Geosciences Faculty Publications

Fault rock low-temperature thermochronometry can inform the timing, temperature, and significance of hydrothermal fluid circulation in fault systems. We demonstrate this with combined hematite (U-Th)/He (He) dating, and sandstone apatite fission-track (AFT) and apatite and zircon (U-Th)/He (He) thermochronometry from fault-related fissures on the Gower Peninsula, Wales. Hematite He dates from 141 ± 5.1 Ma to 120 ± 5.0 Ma overlap with a 131 ± 20 Ma sandstone infill AFT date. Individual zircon He dates are 402–260 Ma, reflecting source material erosion, and imply a maximum Late Permian infill depositional age. Burial history reconstruction reveals modern exposures were not buried …

Instrumentation Enhancements For Electron Yield Measurements Of Extremely Low-Conductivity High-Yield Dielectrics, Justin Christensen, Gregory Wilson, Jr Dennison

Conference Proceedings

Electron yield, a material dependent property which describes how it will charge under incident electron irradiation of a given energy, is defined as the number of electrons emitted from a material per incident electron. While very important for spacecraft charging modelling, the measurement of electron yield for insulating materials is very challenging because insulators quickly charge up under electron irradiation, thereby modifying the yield measurements.

Improved techniques have been implemented to reduce charging with each yield measurement, as well as to neutralize acquired charge between measurements. The goal is to determine the “intrinsic yield” (yield of uncharged insulator). New analysis …

Instrumentation Enhancements For Electron Yield Measurements Of Extremely Low-Conductivity High-Yield Dielectrics, Justin Christensen, Gregory Wilson, Jr Dennison

Presentations

Electron yield, a material dependent property which describes how it will charge under incident electron irradiation of a given energy, is defined as the number of electrons emitted from a material per incident electron. While very important for spacecraft charging modelling, the measurement of electron yield for insulating materials is very challenging because insulators quickly charge up under electron irradiation, thereby modifying the yield measurements.

Improved techniques have been implemented to reduce charging with each yield measurement, as well as to neutralize acquired charge between measurements. The goal is to determine the “intrinsic yield” (yield of uncharged insulator). New analysis …

Complexity And Art, Jeffrey Jenkins

Physics Capstone Projects

A python application was written with the purpose of facilitating the representation of data in both an audio and visual manner. The representations are in the artistic forms of color field paintings and music. This allows for the quick recognition of similarities and differences in the complexities of the data and art. Data was created from musical pieces to give a reference of how closely the program could recreate art. They were chosen from nursery rhymes and Mozart. Also data was generated from random white noise, 1/f, and Brownian data sets. Comparing these data sets showed the greatest similarity between …

Atmospheric Modeling For Opal Mission, Preston Hooser

Physics Capstone Projects

Opal is a CubeSat mission which will measure the neutral temperature of the lower thermosphere (90-140km). It will do this by studying the O2 atmospheric band (A-band), a photoemission of excited molecular oxygen. One of the goals of OPAL is to detect and measure gravity waves traveling up through the region from storms below. In order to do this, it is important to understand the effects of gravity waves on the emission. This paper will describe efforts made to model the atmosphere for preflight mission simulation.

The Equivalence Problem: Einstein­-Maxwell Solutions, Rebecca Whitney

Physics Capstone Projects

The “Equivalence Problem” is part of the Digital Einstein Project. The goal of this project is to create a digital and interactive library of all known solutions to the Einstein field equations in general relativity. The “Equivalence Problem” involves determining when two solutions are physically equivalent. This requires calculating physical and geometric features to characterize each solution independently of any coordinate system. One of the principal features used to characterize the solutions is the degree of symmetry or the isometry group of the space­-time metric. We have focused on the solutions to the Einstein­-Maxwell field equations and compared the isometry …

The Consensus Problem, Cellular Automata, And Self-Replicating Structures, David Griffin

Physics Capstone Projects

Over The course of the last four years I have researched the consensus problem. I have done so by studying how cellular automata following the 2DGKL rule are able to reach consensus in a verity of ways. There are only certain structures that can form within a network, and these structures can be described and examined directly from the rules that make them up. I have also explored a variety of methods to study the rule including, graph theory and liner algebra representations of the cellular automata. Additionally I collected an analyzed data on symmetry in the rule, dependency on …

Enhancing The Reduction Potential Of Quinones Via Complex Formation, Binod Nepal, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Quantum calculations are used to study the manner in which quinones interact with proton-donating molecules. For neutral donors, a stacked geometry is favored over a H-bond structure. The former is stabilized by charge transfers from the N or O lone pairs to the quinone’s π* orbitals. Following the addition of an electron to the quinone, the radical anion forms strong H-bonded complexes with the various donors. The presence of the donor enhances the electron affinity of the quinone. This enhancement is on the order of 15 kcal/mol for neutral donors, but up to as much as 85 kcal/mol for a …

The Role Of A Beaver In Shaping Stream Channel Complexity And Thermal Heterogeneity In A Central Oregon Stream, Florence Consolati Machen

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

North American beaver (Castor canadensis) alter stream channel morphology, hydrologic processes, and instream temperature regimes, yet there are few data driven studies that investigate the effect of beaver on stream channel complexity and stream temperature regimes across multiple spatial and temporal scales. The use of beaver as a restoration tool is a method at the forefront of watershed restoration, however little is known about the implications of this restoration technique, particularly with regard to its ability to alter stream channel complexity and stream temperature. This thesis addresses two knowledge gaps with the following objectives: to quantify the role …

Toward A General Parametric Model For Assessing The Impact Of Video Transcoding On Objective Video Quality, Nawaf Omar N. Alsrehin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The ultimate goal of any video delivery system is to allow any user to watch any video of any kind on any display device over any type of network with a desired output, i.e., viewing codec with preferred quality of service. This could theoretically require 1032 video transcoding functions that convert any original video to any desired output. Guaranteeing a required format and preferred quality of service of the perceived video requires selecting or composing a set of transcoding functions that satisfy the requested format and preferred quality of service. An effective way to accomplish this is by allowing the …

Investigating The Effect Of Carbon Nanotube Functionalization In A Polydimethylsiloxane Composite Through Use Of A Stepped Bar Apparatus, Matthew I. Ralphs

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Thermal interface materials (TIMs) are used in transporting heat away from a circuit or electronic module. Composite materials are a popular research area for TIMs because they allow the desired properties to be joined in a composite to take advantage of the best properties from all the constituents involved. The composite selected for this study uses carbon nanotubes (CNT) as the filler and an elastomeric polymer for the matrix, specifically a multiwalled carbon nanotube (MWCNT) / polydimethylsiloxane (PDMS) composite. This study looks at chemical modification (functionalization) of the CNTin an effort to produce a better bond between the CNT and …

The Eyes Have It: Eye Tracking Data Visualizations Of Viewing Patterns Of Statistical Graphics, Trent Fawcett

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

As statistical graphics continue to expand to manage an ever growing amount of diverse data, a need to evaluate the effectiveness of graphics, both basic and complex, has arisen. Technological advancements have given a means to evaluate the effectiveness of graphs and graphical components through eye tracking systems. Eye tracking systems are likewise in need of software that will enable easy evaluation and exploration of data. The focus of this Master's Report is to evaluate the dual solution. An exploration of an eye tracker setup is made, with extensive consideration of testing statistical graphics providing a basis for continued research …

The Effect Of Pure Infrared Light On The Growth Of Rhodospirrilum Rubrum, Jordan Lee Wilkes

Undergraduate Honors Capstone Projects

Scientists who study aquatic ecosystems quickly notice a diversity of pathways that different microbes and organisms can use to metabolize nutrients found in common ponds or pools. Competition for vital resources, such as light and inorganic minerals, allow only certain organisms to grow in certain niches within these ecosystems. Rhodospirillum rubrum is a gram negative, photosynthetic bacteria that competes for light within aquatic ecosystems in order to survive. R. rubrum is believed to specifically absorb light for photosynthesis at wavelengths in the range of infrared light. It was found that R. rubrum indeed can grow in "dark", anaerobic environments by …

Bayesian Models For Repeated Measures Data Using Markov Chain Monte Carlo Methods, Yuanzhi Li

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bayesian models for repeated measures data are fitted to three different data an analysis projects. Markov Chain Monte Carlo (MCMC) methodology is applied to each case with Gibbs sampling and/or an adaptive Metropolis-Hastings (MH) algorithm used to simulate the posterior distribution of parameters. We implement a Bayesian model with different variance-covariance structures to an audit fee data set. Block structures and linear models for variances are used to examine the linear trend and different behaviors before and after regulatory change during year 2004-2005. We proposed a Bayesian hierarchical model with latent teacher effects, to determine whether teacher professional development (PD) …

Computational Chemistry Of Non-Covalent Interaction And Its Application In Chemical Catalysis, Vincent De Paul Nzuwah Nziko

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Known to be weaker than conventional covalent bonds, non-covalent bonds, especially hydrogen bond, has shown to be of great importance in molecular structures such as DNA, RNA, proteins and other organic frameworks. In this dissertation, we looked at non-covalent interactions other than the hydrogen bond. Replacement of the bridging hydrogen atom in a typical hydrogen bond by other atoms such a halogen, chalcogen and tetrel lead to the formation of interactions which are comparable in strength to the hydrogen bond. Unlike the hydrogen bond which arises mainly from electrostatics, these unconventional interactions mostly result from induction. Besides studying the fundamentals …

Rayleigh-Scatter Lidar Measurements Of The Mesosphere And Thermosphere And Their Connections To Sudden Stratospheric Warmings, Leda Sox

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Earth’s middle atmosphere is comprised of the stratosphere, mesosphere and thermosphere, from approximately 10 to 110 km, or approximately 6 to 68 miles. An understanding of the dynamics and climatological conditions in this region is of vital importance to the aerospace industry and military, which both launch aircraft and spacecraft into this region, as well as researchers who study climate change and the interactions between the atmosphere and the Earth, oceans, and space.

Measurements of atmospheric properties (density, temperature, and pressure) in this region are relatively difficult to gather as the middle atmosphere’s altitudes are both too high for …

Synthesis, Structure-Activity Relationship Study, And Mode Of Action Study Of 1,4-Naphthoquinone Based Anticancer And Antimicrobial Agents, Jaya P. Shrestha

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The first three projects involve the synthesis and the mode of action study of 1,4-naphthoquinone based anticancer agents. These anticancer agents are highly potent against a wide range of cancer cell lines. These compounds showed ~8-fold selectivity towards the lung cancer cell line than the normal cell line. We also studied the mode of action and observed that generation of reactive oxygen species is the primary mode of action.

The final project involves the synthesis of multi-cationic antimicrobial agents. These compounds are active against both bacteria and fungi. These compounds are very easy to synthesize and can be scaled up …

Computational Studies Of Microscopic Superfluidity In 4he Clusters, Angeline R. Wairegi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The onset of microscopic superfluidity has been reported in ultracold droplets of bosons (⁴He atoms or para-H₂ molecules) containing a variety of molecular dopants. The physics of these droplets involve both Bose-Einstein condensation (BEC) and superfluidity. The two phenomena, while closely related, are not exactly the same. Superfluidity is fundamentally a microscopic effect and thermodynamic limit is necessary; it is still remarkable, though, that the signature of superfluidity has been reported in doped droplets consisting of as few as 4 ⁴He atoms. The studies presented here adopt a molecular vantage point to investigate the quantum mechanics …