Physical Sciences and Mathematics Commons^™

Synthesis And Characterization Of Sustainable And Biobased Copolymers From Lignocellulosic, Guery Saenz

Theses and Dissertations

Natural compounds have been the primary resource used to produce polymeric materials by humankind since the mid-1900s. Yet, progress in bio-based polymers from renewable feedstock has encountered some obstacles, mainly due to the low prices of petroleum-based monomers, compared to natural and sustainable materials. However, most commodity plastics are non-degradable materials, and solid plastic waste accumulation adversely affects the environment. As the world population is growing and demanding chemicals, energy, and plastics materials, polymer research is focusing on synthesizing bio-based and degradable polymers. Thus, biomass, a sustainable and inexpensive feedstock, is highly appropriate for designing alternative thermoplastics that are degradable …

Towards Upcycling Biomass-Derived Crosslinked Polymers With Light, Ravichandranath Singathi, Ramya Raghunathan, Retheesh Krishnan, Saravana Kumar Rajendran, Sruthy Baburaj, Mukund P. Sibi, Dean C. Webster, Jayaraman Sivaguru

Chemistry Faculty Publications

Photodegradable, recyclable, and renewable, crosslinked polymers from bioresources show promise towards developing a sustainable strategy to address the issue of plastics degradability and recyclability. Photo processes are not widely exploited for upcycling polymers in spite of the potential to have spatial and temporal control of the degradation in addition to being a green process. In this report we highlight a methodology in which biomass-derived crosslinked polymers can be programmed to degrade at ≈300 nm with ≈60 % recovery of the monomer. The recovered monomer was recycled back to the crosslinked polymer.

Maximization Of Fitness By Phenological And Phenotypic Plasticity In Range Expanding Rabbitfishes (Siganidae), Salvador Zarco-Perello, David Fairclough, Chris Dowling, Joey Dibattista, Rachel Austin, Thomas Wernberg, Brett Taylor

Fisheries Research Articles

1. Global warming is modifying the phenology, life-history traits and biogeography of species around the world. Evidence of these effects have increased over recent decades; however, we still have a poor understanding of the possible outcomes of their interplay across global climatic gradients, hindering our ability to accurately predict the consequences of climate change in populations and ecosystems.
2. We examined the effect that changes in biogeography can have on the life-history traits of two of the most successful range-extending fish species in the world: the tropical rabbitfishes Siganus fuscescens and Siganus rivulatus. Both species have established abundant populations at higher …

Hepatitis B And D: A Forecast On Actions Needed To Reduce Incidence And Achieve Elimination, Scott Greenhalgh, Andrew Klug

Spora: A Journal of Biomathematics

Viral hepatitis negatively affects the health of millions, with the worst health outcomes associated with the hepatitis D virus (HDV). Fortunately, HDV is rare and requires prior infection with the hepatitis B virus (HBV) before it can establish infection and transmit. Here, we develop a mathematical model of HBV and HDV transmission in Sub-Saharan Africa to investigate the effects of hepatitis B vaccination on both HBV and HDV. Our findings illustrate a hepatitis B vaccination rate above 0.006 year^-1 reduces hepatitis D by over 90%, and a vaccination rate above 0.0221 year^-1 reduces hepatitis B by over 90%, …

The Best Linear Approximation To Y= √X On The Interval [0, B] Using The Minimax Error, Hyounkyun Oh

Georgia Journal of Science

This study discusses how to find the best linear approximation y=mx+b to a fundamental function y=sqrt(x) on the interval [0,b], especially using the minimax error in Numerical Analysis. For this aim we employ two mathematical techniques: a) using the MATLAB code, positioning m and n values of the smallest maximum error on a broad range of m, and n value matrix in a rough scale and then repeatedly refining the regions in the smaller scales and b) Finding three-point fitting line to a set of non-colinear three points. We see that both results are successfully obtained and identical …

Sustainable Rural Development: Is It Possible To Boost Rural Economies While Protecting The Environment?, Jack M. Hempleman

Undergraduate Theses, Capstones, and Recitals

Amidst rapid depletion of our carbon budget, the need to change our practices to be more in line with Earth’s limits has become important in every sector of our economy. From advances in renewable energy generation to the growth of urban gardening, people around the world are taking action to change the way they interact with our planet. However, growing concerns have been raised that protections for the environment will disproportionately harm struggling communities. For instance, rural communities in the United States already exhibit disproportionately high poverty rates, income inequality, and unemployment, as well as lower quality healthcare and public …

Monolithically Integrated Microscale Pressure Sensor On An Optical Fiber Tip, Jeremiah C. Williams, Hengky Chandrahalim

AFIT Patents

A passive microscopic Fabry-Pérot Interferometer (FPI) pressure sensor includes an optical fiber and a three-dimensional microscopic optical enclosure. The three-dimensional microscopic optical enclosure includes tubular side walls having lateral pleated corrugations and attached to a cleaved tip of the optical fiber to receive a light signal. An optically reflecting end wall is distally engaged to the tubular side walls to enclose a trapped quantity of gas that longitudinally positions the optically reflecting end wall in relation to ambient air pressure, changing a distance traveled by a light signal reflected back through the optical fiber.

Mesosphere And Lower Thermosphere Changes Associated With The 2 July 2019 Total Eclipse In South America Over The Andes Lidar Observatory, Cerro Pachon, Chile, A. Liu, F. Vargas, G. Swenson, C. Segura, P. Vega, J. Fuentes, D. Pautet, M. Taylor, Y. Zhao, Y. Morton, H. Bourne

Publications

This article presents the results of a week of observations around the 2 July 2019, total Chilean eclipse. The eclipse occurred between 19:22 and 21:46 UTC, with complete sun disc obscuration at 20:38–20:40 UTC (16:38–16:40 LT) over the Andes Lidar Observatory (ALO) at (30.3°S, 70.7°W). Observations were carried out using ALO instrumentation with the goal to observe possible eclipse-induced effects on the mesosphere and lower thermosphere region (MLT; 75–105 km altitude). To complement our data set, we have also utilized TIMED/SABER temperatures and ionosonde electron density measurements taken at the University of La Serena's Juan Soldado Observatory. Observed events include …

Orbital Analysis Of Bonding In Diarylhalonium Salts And Relevance To Periodic Trends In Structure And Reactivity, Shubhendu S. Karandikar, Avik Bhattacharjee, Bryan Metze, Nicole Javaly, Edward J. Valente, Theresa M. Mccormick, David R. Stuart

Chemistry Faculty Publications and Presentations

Diarylhalonium compounds provide new opportunities as reagents and catalysts in the field of organic synthesis. The three center, four electron (3c–4e) bond is a center piece of their reactivity, but structural variation among the diarylhaloniums, and in comparison with other λ3-iodanes, indicates that the model needs refinement for broader applicability. We use a combination of Density Functional Theory (DFT), Natural Bond Orbital (NBO) Theory, and X-ray structure data to correlate bonding and structure for a λ3-iodane and a series of diarylchloronium, bromonium, and iodonium salts, and their isoelectronic diarylchalcogen counterparts. This analysis reveals that the s-orbital on the central halogen …

Optimization Of Paper-Based Substrates For Surface Enhanced Raman Spectroscopic Biosensor Development, Kaylee M. Cappuccio

Undergraduate Honors Theses

Advancements in the field of analytical chemistry have greatly expanded the development of biosensors for the detection of a wide array of diseases. This study aims to optimize an affordable paper-based nanocomposite biosensor that utilizes surface-enhanced Raman spectroscopy (SERS). Specifically, it investigates the preparation parameters for a paper-based SERS substrate, including nanoparticle administration and drying procedures. A particular focus of this work is to assess how the wax-defined paper channels can effectively enhance SERS intensity. The results revealed that while the wax-printed wells can define the nanoparticle administration for SERS detection, wax backing may reduce the sensitivity of SERS by …

Multifunctional Carbon-Supported Cobalt-Nickel Compounds For Water Splitting And Energy Storage Applications, Wang Lin

Electronic Theses & Dissertations

In order to effectively reduce carbon emission and achieve the goal of mitigating climate change, hydrogen energy has high hopes as a representative of green energy. According to the most current and updated research, compounds of cobalt and nickel have been widely studied as alternatives instead noble metal materials as catalysts for the electrolysis of water. Based on some other research reports, a hydrothermal method to grow cobalt-nickel hydroxide on nickel foam that has been carbonized in advance was proposed. To compare the modification results of these materials by different activation methods, calcination, sulfidation, and phosphating were performed on the …

Teaching & Learning Guide For Disability And Climate Justice, Molly M. King, Maria A. Gregg, Ana V. Martinez, Emily Y. Pachoud

Sociology

Disability is widespread: nearly one in four Americans has a disability (Taylor, 2018) and disability cuts across demographic categories. Among individuals aged 15 and over, 12.6% had some type of mobility disability; above age 65, it is nearly 40% (Brault, 2012). Mobility disabilities heighten vulnerability to climate change and climate-related disasters (UNHCHR, 2020). Reduced information resources and mobility, increased health risks, and a lack of visibility in climate change discourse put people with disabilities in a more vulnerable position in the climate crisis. However, this vulnerability can be mitigated through relevant and sufficient access to information, risk mitigation …

Analysis Of The Effectiveness Of Different Techniques For Creating Cross-Platform Compatible Software, Michael Westberg

Honors Theses

Creating cross-platform compatible software is a major issue in a world where users utilize a variety of devices and platforms. To ensure that a piece of software is accessible to as many users as possible, software must be cross-platform compatible. There are four main approaches that can be done to achieve this state of being cross-platform compatible, each with both advantages and disadvantages. These methods are: creating the software as separate binaries, using a scripting language with a cross-platform interpreter, compiling to an intermediate language, and creating the software as a web application. This paper will discuss how each of …

A Framework Comparison: .Net And Laravel, Guy Richard

Honors Theses

No abstract provided.

Seasonal Variation And Tracking Of Climate Niche Of A Migratory Bird, Javier Gutiérrez Illán, Guiming Wang, D. Tommy King, Fred L. Cunningham

United States Department of Agriculture Wildlife Services: Staff Publications

Migratory birds inhabit different areas during breeding and non-breeding seasons. Depending on the time of the year, they may utilize different resources available in seasonal habitats, but also are subjected to changing climate regimes during their annual life cycle. Migratory birds may adopt ecological niche tracking to cope with different environmental conditions between breeding and non-breeding grounds. The American White Pelican (Pelecanus erythrorhynchos, hereafter ‘AWPE’) is a short-distance migrant between the Gulf of Mexico coastal regions (nonbreeding grounds) and the Northern Great Plains (breeding grounds) of Canada and the US. The American White Pelican is a piscivore, feeding …

Determinations Of Chemical Equilibria In Natural Waters Using Spectrophotometric Techniques, Katelyn M. Schockman

USF Tampa Graduate Theses and Dissertations

Accurate characterizations of chemical equilibria and thermodynamic processes in natural waters are key components for assessing the current state of our global climate and predicting future changes, especially for observations of small rates of change over long time scales. One of the most important chemical systems in natural waters is the system of inorganic carbon species comprised of carbon dioxide (CO2), bicarbonate, and carbonate. The bicarbonate dissociation constant, K2, describes the relationship between pH and the relative concentrations of bicarbonate and carbonate ions at thermodynamic equilibrium. The carbonate/bicarbonate equilibrium quotient is required in nearly all CO2 system calculations relevant to …

Biophysical Insight Into The Sars-Cov2 Spike–Ace2 Interaction And Its Modulation By Hepcidin Through A Multifaceted Computational Approach, Hamid Hadi-Alijanvand, Luisa Di Paola, Guang Hu, David M. Leitner, Gennady M. Verkhivker, Peixin Sun, Humanath Poudel, Alessandro Giuliani

Mathematics, Physics, and Computer Science Faculty Articles and Research

At the center of the SARS-CoV2 infection, the spike protein and its interaction with the human receptor ACE2 play a central role in the molecular machinery of SARS-CoV2 infection of human cells. Vaccine therapies are a valuable barrier to the worst effects of the virus and to its diffusion, but the need of purposed drugs is emerging as a core target of the fight against COVID19. In this respect, the repurposing of drugs has already led to discovery of drugs thought to reduce the effects of the cytokine storm, but still a drug targeting the spike protein, in the infection …

Quantifying Impacts Of Grazing And Poor Land Management Strategies On Erosion Through A Semi-Automated Change Detection Workflow In Ka’Amola, Molokai, L. Kalai Ellis, Richard A. Gill

Utah Space Grant Consortium

A challenge faced by those working in a system plagued by non-native vegetation invasion and disturbance from ungulates is the ability to collect landscape-level information about land cover change and the mass movement of soils associated pulsed rainfall events. Our goal was to conduct high-precision change detection of land cover and surface features during a two-year period that included several mass sediment flux events associated with tropical storms. We present here preliminary results of the development and testing of a rule set based classification algorithm used to classify imagery from 2019 and 2021 of a single watershed in Molokai to …

Aerodynamic Effects Of Phase Offset Between Synchronized Propellers In Hover, Nathan Welker, Daniel Maynes

Utah Space Grant Consortium

Emerging advances in electric-propulsion technology are enabling aircraft to use distributed electric propulsion (DEP) to increase efficiency and maneuverability. The implementation of DEP effectively decreases the spacing between propellers, introducing complex aerodynamic interactions that are not well understood. This study presents the use of stereoscopic particle image velocimetry (SPIV) to obtain 3D velocity measurements of the flow fields of phase locked and synchronized propellers at close proximity in a side-by-side configuration. These experiments were performed to explore the aerodynamic effect of phase offset between the propellers. It was found that while the propeller interactions cause an induced upwash and a …

Biophysical Factors Control Invasive Grass Hot Spots In The Mojave Desert, Tanner C. Smith, Tara B. B. Bishop, Michael C. Duniway, Ryan R. Jensen, Richard A. Gill

Utah Space Grant Consortium

Invasive annual grasses are a nuisance in the American Southwest through promotion of the grass-fire cycle. Annual grasses such as Bromus rubens, Bromus tectorum, Schismus barbatus, and Schismus arabicus have invaded the Mojave Desert and increased fire occurrence, thus it is important to identify and characterize the areas where persistent invasion has occurred and subsequently fire risk is increased by understanding the distribution of these invasive grasses. Here we use a remote sensing framework to map persistent and productive populations of invasive annual grass, called hot spots, in the entire Mojave Desert ecoregion over 12 years, identify …

Progress Report: Covid-19 Hotspot Detection In University Campus Settings, Garrett Duncan, William F. Christensen, Camilla Handley

Utah Space Grant Consortium

The COVID-19 pandemic caused a lot of disruption in the academic world. Many schools and universities shut down entirely and transitioned to online learning. As BYU made the transition back to in-person learning, the administration needed to know if there was in-class transmission happening on campus in order to regulate restrictions and keep students and faculty safe. Using demographic information about the students, we built an XGBoost model that produces an estimated probability of testing positive for each student. We incorporated engineered variables from the demographic information as well. We evaluated model fit using metrics such as AUC. Using a …

Internal Wave Generation By Multiple Peak Topographies, Natsha Wilson, Julie Crockett

Utah Space Grant Consortium

Internal waves are generated in the oceans and atmosphere and play an important role in their energy budgets. The semidiurnal oscillation of the tides over topography in the oceans combined with the density stratification can create internal waves that radiate away from their source. The effect of multiple peaks on a single topography has on internal wave generation is explored. Initial results begin to show that multiple ridges create two parallel IW beams with smaller IWs between them compared to the single beam created by a one ridge topography. Kinetic energy is also tightly clustered at lower wavenumbers in Fourier …

Exploration Of An Electrochemical Sensor For Continuous Monitoring Of Estradiol In Application To Fertility Tracking, Julia S. Dominesey, Shad J. Roundy

Utah Space Grant Consortium

Estradiol is one of three estrogens, the primary female sex hormone; it fluctuates diurnally, and monthly, dictating the menstrual cycle. We developed a bench-top electrochemical sensor to detect estradiol with the intention of future realization into an implantable, continuously sampling sensor to be used as an aid for fertility health. The electrochemical sensor is comprised of a three electrode system which utilizes a gold working electrode, platinum counter electrode, and Ag/AgCl reference electrode to perform cyclic voltammetry. A monolayer of estradiol aptamers and mercaptohexanethiol coat the working electrode surface. The monolayer was exposed to 10ng/mL, 100n/mL and 1,000ng/mL of estradiol. …

Refill Friction Stir Spot Welding As An Alternative Jointing Method For Wing Spar Structures, Paul Blackhurst, Yuri Hovanski, Andrew Curtis

Utah Space Grant Consortium

Refill Friction Stir Spot Welding (RFSSW) is an emerging solid state joining process for thin sheet aluminum. Many researchers are developing RFSSW process parameters, thus enabling the use of RFSSW in many industries. Some work within this development has been on the application of RFSSW to wing spar stringer and skin joining. This is thanks to the RFSSW process being capable of welding the high-strength aluminum alloys used for wing spar construction. Traditionally wing spar joining has been achieved using rivets. This newer method has the potential to improve the strength, reduce the weight, and lower the cost of wing …

Development Of Optical Systems For In-Situ Measurements Of High-Temperature Combustion Plumes, Cara Frischkorn, Stephen A. Whitmore

Utah Space Grant Consortium

Results from proof-of-concept tests using fiber-optic cables inserted into the combustion port of a lab-scale hybrid rocket system are reported. The fiber optic cables transmit optical signals to miniature spectrometers and allow in-situ optical characterization of the combustion plume properties including flame temperature and combustion plume species. Multiple firings with burn durations varying from 5 to 25 seconds were performed. The fiber optic sensors survived all tests and resulting rocket performance data were correlated with in-situ optical spectra data. When the optical measurements were adjusted to account for the spectrometer transfer function and the resulting spectra were curve-fit to Planck's …

Ionosphere/Thermosphere Dynamics Obtained From Cosmic Satellite Observations, Layne Pedersen, Ludger Scherliess

Utah Space Grant Consortium

The morphology and climatology of thermospheric neutral winds play an important role in ionospheric and thermospheric dynamics. Thermospheric neutral winds effect temporal and spatial variations of ionospheric plasma which plays an important role F-region dynamics. However, direct observations of thermospheric neutral winds are historically limited both temporally and spatially [1]. For example, interferometric methods for measuring thermospheric winds are restricted to nighttime observations and cloudless conditions and are limited to relatively few locations. Space-based observations made by cross-track measurements from accelerometers as well as onboard interferometers and spectrometers provide valuable information of thermospheric winds but coverage is inconsistent over a …

Acoustic Analysis Of The Delta Iv Heavy Launch Vehicle, Griffin Houston, Grant W. Hart, Kent L. Gee

Utah Space Grant Consortium

The Delta IV Heavy is an orbital heavy class launch vehicle that has been in operation since 2004. In this study, the overall sound power level and other acoustic properties of the Delta IV Heavy launch vehicle will be calculated and analyzed. Five data acquisition systems with a wide frequency bandwidth were placed in a far-field arc around a 2021 launch. Using a weighted mean to compare results across stations, a maximum overall sound pressure level (OASPL) of 140 dB and an average maximum polar directivity angle of 69 deg were calculated. An overall sound power level of 198 dB …

Selecting Appropriate Axis Of Movement For Accurate Breath Detection, Magaly Sencion, Joe Orr, Lara Brewer

Utah Space Grant Consortium

Opioid-Induced Respiratory Depression can be characterized as a severe side effect of opioid therapy that is well known for causing high mortality rates in the postoperative period. Other than suppressing various respiration parameters, like those such as respiration rate or tidal volume, the effects of opioids can lead to irregular breathing patterns.

A 3-axis accelerometer has been proposed as an affordable respiratory sensor to detect suppressed respiratory drive. The challenge is to identify the best signal of three recorded axes.

In this study, we tested an algorithm that could automatically detect the best signal of the three recorded axes (x,y, …

Modeling Brown Dwarf Atmospheres In Preparation For Jwst Observations, Brayden Roberts, Joshua Lothringer

Utah Space Grant Consortium

Using three inputs, metallicity, effective temperature, and surface gravity, we can model a BD to simulate traits like pressure, temperature, density, spectra, etc.

By comparing the modeled spectra with observed spectra, we can make changes to our models to make them more accurate.

Byu Propulsion Development – Experimental Lox/Paraffin Hybrid Rocket, Jayson Davis, Lincoln Stewart, Logan Morse, David Andelin, Joshua Cook, Brennen Dover, Cameron Van Dyke, Cole Halverson, Elizabeth Barnett, Eric Christie, Gerritt Graham, Jacob Hansen, Jason Metten, Kendall Green, Matt Bozer, Oscar Escobar, Samuel Craven, Zachary Lyman, Courtney Payne, Ben Larson, Tyson Butterfield

Utah Space Grant Consortium

The "Blue Jay" is a 12 ft., LOX and paraffin hybrid rocket with a designed total impulse of 20,330 Ns. The rocket will have its maiden flight summer 2022 at the Friends of Amateur Rocketry with a target altitude of 10,000 ft. above ground level. The rocket is expected to weigh around 100 lbs. dry. This is BYU's first hybrid rocket, and one of the first LOX paraffin hybrids to be flown. The rocket is divided into four subsystems: structures and recovery, electronics and controls, plumbing, and propulsion.