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Articles 59281 - 59310 of 302480

Full-Text Articles in Physical Sciences and Mathematics

Defect Detection In Atomic Resolution Transmission Electron Microscopy Images Using Machine Learning, Philip Cho, Aihua W. Wood, Krishnamurthy Mahalingam, Kurt Eyink May 2021

Defect Detection In Atomic Resolution Transmission Electron Microscopy Images Using Machine Learning, Philip Cho, Aihua W. Wood, Krishnamurthy Mahalingam, Kurt Eyink

Faculty Publications

Point defects play a fundamental role in the discovery of new materials due to their strong influence on material properties and behavior. At present, imaging techniques based on transmission electron microscopy (TEM) are widely employed for characterizing point defects in materials. However, current methods for defect detection predominantly involve visual inspection of TEM images, which is laborious and poses difficulties in materials where defect related contrast is weak or ambiguous. Recent efforts to develop machine learning methods for the detection of point defects in TEM images have focused on supervised methods that require labeled training data that is generated via …


Areas Suitable For Living Shorelines: Ranked For Co-Benefits Provided, Pamela Mason, Tamia Rudnicky, Jessica Hendricks, Marcia Berman May 2021

Areas Suitable For Living Shorelines: Ranked For Co-Benefits Provided, Pamela Mason, Tamia Rudnicky, Jessica Hendricks, Marcia Berman

Data

The Center for Coastal Resources Management (CCRM) at the Virginia Institute of Marine Science (VIMS) has been developing tools to guide local governments in shoreline management. Using a number of criteria, the Shoreline Management Model (SMM) determines appropriate shoreline best management practices. This layer contains only those areas determined to be suitable for non-structural plant marsh or plant marsh with sill recommendations. These areas are prioritized using a scoring method that considers nutrient removal potential, benefits provided to coastal buildings, the potential for the project to provide habitat continuity and enhancement, and the potential the project to add resilience for …


Toward A More Holistic Worldview: Environmental Values In Context, Erica Lynne Walters May 2021

Toward A More Holistic Worldview: Environmental Values In Context, Erica Lynne Walters

Undergraduate Honors Thesis Collection

This study extensively examines the formation of pro-environmental behaviors as mediated by the Value-Belief-Norm (VBN) Theory. Using this theoretical framework, qualitative, in-depth interviews were conducted with a small number of Butler University students (n=10). The findings of the data collection demonstrate the limitations of the VBN Theory when applied to pro-environmental behavior. Data analysis demonstrates the role that formative experiences, environmental education, and connectedness to nature can play as intervening influences in the linear translation posited by the VBN Theory. Moreover, the confluence of various values that emerged among research participants suggests the need for a more holistic value orientation …


Optimal Control Of Algae Biofilm Growth In Wastewater Treatment Using Computational Mathematical Models, Gerald Benjamin Jones May 2021

Optimal Control Of Algae Biofilm Growth In Wastewater Treatment Using Computational Mathematical Models, Gerald Benjamin Jones

Undergraduate Honors Capstone Projects

Microalgal biofilms are comprised of a syntrophic consortium of microalgae and other microorganisms embedded within an extracellular matrix. Despite significant processes in the application of microalgal biofilms in wastewater treatment, mechanistic understanding and optimization of microalgal biomass yield and productivity under environmental constraints is still lacking. This paper identifies theoretical insights on this challenging biological problem by leveraging novel mathematical and computational tools. In particular, through a computational mathematical model to advance the understanding of microalgal biofilm growth kinetics under environmental constraints through a systematic parameter study. Moreover, design of algae biofilm reactors for optimal biomass yield and productivity in …


The Reflection Of Light From Periodic Conducting Interfaces, Christian Lange May 2021

The Reflection Of Light From Periodic Conducting Interfaces, Christian Lange

Undergraduate Honors Capstone Projects

It is known that carbon-nanotube (CNT) forests, nanopillar arrays, and other high aspect-ratio conducting and semi-conducting nanostructures can have extremely low reflectance in a wide range of wavelengths, and that reflectance begins to rise at long wavelengths. The mechanism for this behavior is poorly understood. It has been shown that the reflectance of CNT forest varies with the morphology of the forest, which indicates that the interface of such a material may play a primary role in its reflectance and absorptance.

Simulations of the reflection of light from arrays of conducting nanorods using commercial finite-difference-time-domain software predict a similar increase …


Environmental Racism In A Growing City: Investigating Demographic Shifts In Salt Lake City's Polluted Neighborhoods, Emma Nathel Jones May 2021

Environmental Racism In A Growing City: Investigating Demographic Shifts In Salt Lake City's Polluted Neighborhoods, Emma Nathel Jones

Undergraduate Honors Capstone Projects

Studies investigating the spatial distribution of environmental hazards have repeatedly demonstrated the existence of environmental racism -- the disproportionate impact of environmental hazards on communities of color. We aim to contribute to research on environmental racism by asking how relationships between race and hazard exposure change over time. Our study area, Salt Lake City (SLC), UT, USA is one of the largest cities in the intermountain west and is expected to see continued population growth. SLC was 99% white from 1860-1950. 2019 census estimates indicate that SLC is becoming more racially diverse with 35.6% of the population identifying as racial …


Circular Dichroism In Atomic Resonance-Enhanced Few-Photon Ionization, A. H. N. C. De Silva, T. Moon, Daniel Fischer, For Full List Of Authors, See Publisher's Website. May 2021

Circular Dichroism In Atomic Resonance-Enhanced Few-Photon Ionization, A. H. N. C. De Silva, T. Moon, Daniel Fischer, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

We investigate few-photon ionization of lithium atoms prepared in the polarized 2p(m = +1) state when subjected to femtosecond light pulses with left- or right-handed circular polarization at wavelengths between 665 and 920 nm. We consider whether ionization proceeds more favorably for the electric field co- or counter-rotating with the initial electronic current density. Strong asymmetries are found and quantitatively analyzed in terms of "circular dichroism"(CD). While the intensity dependence of the measured CD values is rather weak throughout the investigated regime, a very strong sensitivity on the center wavelength of the incoming radiation is observed. While the co-rotating …


Assessing The Real-Time Lagrangian Predictability Of The Operational Navy Coastal Ocean Model In The Gulf Of Mexico, Lea Kristen Locke May 2021

Assessing The Real-Time Lagrangian Predictability Of The Operational Navy Coastal Ocean Model In The Gulf Of Mexico, Lea Kristen Locke

Dissertations

This study quantitatively assesses the drift predictive skill of Fleet Numerical Meteorology and Oceanography Center’s (FNMOC’s) operational ocean models which are used to support a wide range of military and civilian applications. Overall, the findings of this work support the recommendation of spatial filtering for regional-scale ocean model velocity fields used in deep-water drift applications. In conjunction with filtering, the use of a pure particle drift algorithm is suggested for short-term forecasts and a drift algorithm including a sub-grid scale, random flight, parameterization for predictions requiring extended forecast predictions.

Drift prediction skill is quantified through metrics of in-cloud percentage, distance …


Anomalous Dimensions From Yukawa Couplings In Smneft: Four-Fermion Operators, Alakabha Datta, Jacky Kumar, Hongkai Liu, Danny Marfatia May 2021

Anomalous Dimensions From Yukawa Couplings In Smneft: Four-Fermion Operators, Alakabha Datta, Jacky Kumar, Hongkai Liu, Danny Marfatia

Faculty and Student Publications

The Standard Model Neutrino Effective Field Theory (SMNEFT) is the Standard Model Effective Field Theory (SMEFT) augmented with right-handed neutrinos. Building on our previous work, arXiv:2010.12109, we calculate the Yukawa coupling contributions to the one-loop anomalous dimension matrix for the 11 dimension-six four-fermion SMNEFT operators. We also present the new contributions to the anomalous dimension matrix for the 14 four-fermion SMEFT operators that mix with the SMNEFT operators through the Yukawa couplings of the right-handed neutrinos.


Electronic Structure And Dynamics Of Uranyl-Peroxide Species, Ethan T. Hare May 2021

Electronic Structure And Dynamics Of Uranyl-Peroxide Species, Ethan T. Hare

Honors Thesis

Uranyl-peroxide nanocapsules are a unique family of self-assembled actinide species. Uranyl ions rapidly self-assemble in basic peroxidic media through a myriad of reactions to coalesce into a single nanocapsule that includes both peroxide and hydroxide bridging groups between the uranyl moieties. A wide variety of capsules can be formed, and it has been proposed that square and pentagonal building blocks assemble prior to nanocapsule formation. We have studied the speciation of the pentagonal 2) uranyl-peroxide nanocapsule building blocks using density functional theory calculations. We predicted the most favorable speciation pathways for the self-assembly of the building blocks prior to cluster …


Synthesis And Characterization Of Functiona Materials For 3d Printed Composites, Elizabeth Irene Reza May 2021

Synthesis And Characterization Of Functiona Materials For 3d Printed Composites, Elizabeth Irene Reza

Open Access Theses & Dissertations

The following body of work encompasses the synThesis, upscaling, additive manufacturing, and characterization of microspheres as functional fillers incorporated into polymer syntactic foams. Synthesizing microspheres permits control over morphology, dispersion of particles, and size while the use of direct write manufacturing allowed for the controllability of filler orientation. Two different syntactic foams were developed from similar methodologies: (1) a silicone syntactic foam (2) epoxy syntactic foam. The silicone epoxy foam showed an increasing in damping and elastic modulus. The epoxy syntactic foams showed an enhanced thermal and electrical properties.


Fundamental Aspects Of Black Holes, Jacob Fisher Ciafre May 2021

Fundamental Aspects Of Black Holes, Jacob Fisher Ciafre

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

The literature study here seeks to present the foundations of black hole physics in General Relativity. The report includes a discussion of the Kerr black hole metric, black hole entropy, particle creation, the laws of black hole mechanics, and a bilinear mass formula for the Kerr-Newman black hole solution.


Impacts Of Multiple Environmental Changes On Long- Term Nitrogen Loading From The Chesapeake Bay Watershed, Shufen Pan, Zihao Bian, (...), Marjorie A.M. Friedrichs, Et Al May 2021

Impacts Of Multiple Environmental Changes On Long- Term Nitrogen Loading From The Chesapeake Bay Watershed, Shufen Pan, Zihao Bian, (...), Marjorie A.M. Friedrichs, Et Al

VIMS Articles

Excessive nitrogen can enter estuarine and coastal areas from land, disturbing coastal ecosystems and causing serious environmental problems. The Chesapeake Bay is one of the regions that have experienced hypoxia and harmful algal blooms in recent decades. This study estimated nitrogen export from the Chesapeake Bay watershed (CBW) to the estuary from 1900 to 2015 by applying a state-of-the-art numerical model. Nitrogen loading from the CBW continually increased from the 1900s to the 1990s and has declined since then. The key contributors to nitrogen export have shifted from atmospheric nitrogen deposition (before the 1960s) to synthetic nitrogen fertilizer (after the …


Multi-Scale Computational Modeling Of Metal/Ceramic Interfaces, Abu Shama Mohammad Miraz May 2021

Multi-Scale Computational Modeling Of Metal/Ceramic Interfaces, Abu Shama Mohammad Miraz

Doctoral Dissertations

Multi-scale atomistic calculations were carried out to understand the interfacial features that dictate the mechanical integrity of the metal/ceramic nanolaminates. As such, first principles density functional theory (DFT) calculations were performed to understand the electronic and atomistic factors governing adhesion and resistance to shear for simple metal/ceramic interfaces, whereas molecular dynamics (MD) simulations were performed to observe the impact of interfacial structures, such as misfit dislocation network geometries and orientation relationships, on interfacial mechanical properties.

For the DFT investigation, we choose metals with different crystal structures, namely - Cu (fcc), Cr (bcc) and Ti (hcp) along with a variety of …


The Future Of Artificial Intelligence In The Healthcare Industry, Erika Bonnist May 2021

The Future Of Artificial Intelligence In The Healthcare Industry, Erika Bonnist

Honors Theses

Technology has played an immense role in the evolution of healthcare delivery for the United States and on an international scale. Today, perhaps no innovation offers more potential than artificial intelligence. Utilizing machine intelligence as opposed to human intelligence for the purposes of planning, offering solutions, and providing insights, AI has the ability to alter traditional dynamics between doctors, patients, and administrators; this reality is now producing both elation at artificial intelligence's medical promise and uncertainty regarding its capacity in current systems. Nevertheless, current trends reveal that interest in AI among healthcare stakeholders is continuously increasing, and with the current …


Effects Of Bounding Tree Complexity On Immersion In A Virtual Environment, Jonathan Caputo May 2021

Effects Of Bounding Tree Complexity On Immersion In A Virtual Environment, Jonathan Caputo

Honors Theses

Bounding boxes are volumetric spaces in a 3D environment defined by a set of points that denote the area of collision for a given object. Bounding trees are known as a collection of bounding boxes. Simple bounding trees contain few bounding boxes and complex bounding trees contain many. Our research aims to find the relationship between the complexity of a bounding tree and a user's immersion in a 3D virtual environment. We created an algorithm that used the bounding trees to check for when an object collides with another. Using this algorithm, we ran a user study where users would …


Long-Term Changes In Soil Surface Properties As Affected By Management Practices In A Wheat-Soybean, Double-Crop System, Machaela Morrison May 2021

Long-Term Changes In Soil Surface Properties As Affected By Management Practices In A Wheat-Soybean, Double-Crop System, Machaela Morrison

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Long-term agricultural sustainability and productivity are controlled by the integrative effects of different management practices on the soil. Many Arkansas producers use the double-crop system to grow soybeans [Glycine max (L.) Merr] and wheat (Triticum aestivum L.). Studying combinations of different, non-traditional, alternative agricultural techniques may help producers better understand the long-term implications of various management practice options on sustainability and productivity. The objective of this study was to evaluate the effects of agricultural management practices, including residue level, tillage, irrigation, and burning, and soil depth on the change in various soil properties from 2010 to 2020 in …


A Comparison Of The Environmental Effects Of Renewable And Non-Renewable Energies, Jordan Moore May 2021

A Comparison Of The Environmental Effects Of Renewable And Non-Renewable Energies, Jordan Moore

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

This study presents current energy data from the United States and data from literature reviews to create life cycle assessments (LCA) for comparing the environmental impacts of wind and coal-fired energy generation and use. The environmental impacts were evaluated using emissions data, principally carbon dioxide emissions and carbon dioxide equivalents from methane. Other environmental impacts such as avian mortality and land use were compared as well. The LCA includes four phases: raw materials, transportation, use/retail, and waste. Overall, wind energy has a smaller environmental impact than coal-fired energy for the raw materials, transportation, use/retail, and waste phases. Wind energy resulted …


Low Impact Development: Low-Maintenance Design To Encourage Residential Adoption Of Sustainable Systems, Haley Ellis May 2021

Low Impact Development: Low-Maintenance Design To Encourage Residential Adoption Of Sustainable Systems, Haley Ellis

Biological and Agricultural Engineering Undergraduate Honors Theses

Residential adoption of low-impact development (LID) technology can positively impact downstream watershed hydrology by reducing total volumetric discharge from the residential site. This reduction can provide economic, environmental, and social benefits for the residents as well as the community at large. Additionally, homeowners are often affected by stormwater related issues, like flooding or washout, that could be easily mitigated with a sustainably engineered LID structure or network. Engineering for sustainability often includes the blending of several objectives to provide greater overall benefit. This thesis compares the outflow characteristics of three low-maintenance residential LID design scenarios differing in rain garden soil …


Estimating Irrigation In Rice Fields With A Water Balance Approach, Kristen Trinh May 2021

Estimating Irrigation In Rice Fields With A Water Balance Approach, Kristen Trinh

Biological and Agricultural Engineering Undergraduate Honors Theses

Global food production must increase to meet the demand associated with increased population growth, so irrigation water use will continue to rise. Therefore, it is important to monitor water usage particularly when an irrigation flowmeter is unavailable. A field water balance was created for a selection of rice fields in East-central Arkansas under observation in 2018 and 2019. From those, irrigation inputs are deduced from the water balance alone. First, each field had sensors that collected water table level (WTL) data. Next, other water inputs and outputs such as precipitation and evapotranspiration (ET) were collected from two modeled sources. The …


Comparative Analysis Of Azo Dye Restriction In The International Textile Industry, Kayla Demark May 2021

Comparative Analysis Of Azo Dye Restriction In The International Textile Industry, Kayla Demark

Apparel Merchandising and Product Development Undergraduate Honors Theses

Azo dyes are the most used type of dye in the textile industry. Some of these dyes have the potential to be extremely toxic to both human health and the environment. While regulations of these dyes vary across the world, it is suggested that not enough is being done to protect consumers and the environment from potentially harmful azo dyes (Rawat et al., 2016). It is the responsibility of apparel companies to ensure that their products that contain azo dyes are safe for consumers.

The purpose of this study was to understand how azo dyes and their by-products are restricted …


Investigating The Potential Of A Combined Air Quality-Heat Index In Predicting Mortality, Shayna Fever May 2021

Investigating The Potential Of A Combined Air Quality-Heat Index In Predicting Mortality, Shayna Fever

Theses and Dissertations

Although the development of the Air Quality Index (AQI) has been significant in informing and protecting the public, it may not be entirely reflective of the health effects from exposure to air pollutants. Meteorological factors that are considered in the heat index (HI), temperature and relative humidity, are not considered when calculating the AQI. It may be important to consider certain meteorological factors when assessing the quality of the air because such factors affect the dynamics of air movement as well as the formation of certain pollutants.Through a series of Quasi-Poisson regression models, we investigated whether the relationship between the …


Fluvial And Sequence Stratigraphy Analysis Of The Hell Creek And Fort Union Formations To Test Models For Sedimentation Across The Cretaceous-Paleogene Boundary In Makoshika State Park, Glendive, Montana, Quintin Bendixen May 2021

Fluvial And Sequence Stratigraphy Analysis Of The Hell Creek And Fort Union Formations To Test Models For Sedimentation Across The Cretaceous-Paleogene Boundary In Makoshika State Park, Glendive, Montana, Quintin Bendixen

Theses and Dissertations

The Cretaceous-Paleogene Boundary outcrops extensively throughout Makoshika State Park in Glendive, Montana. A distinct change in sedimentation style occurs across the Cretaceous- Paleogene in the Williston Basin deposits found in eastern Montana and western North Dakota. The well documented Hell Creek Formation of the Upper Cretaceous period consists of fresh and brackish water influenced deposits on the western low-lying coast of the Western Interior Seaway. The overlying Fort Union Formation consists of coals and fluvial sandstone deposits. Geologic explanations for the depositional shift include tectonic forces of the Sevier/Laramide Orogeny to the west, The Cretaceous-Paleogene Extinction Event, and the advancement …


Autumn Tree Phenology In Northern Wisconsin: Humans Versus Photographs, Trevor Iglinski May 2021

Autumn Tree Phenology In Northern Wisconsin: Humans Versus Photographs, Trevor Iglinski

Theses and Dissertations

Ecosystem primary productivity halts when plants go dormant, and so the timing of dormancy as it relates to autumn phenology has been a focus of much interdisciplinary research. While monitoring plant phenology has its roots in directly observing specimens, digital sensors along with modern methods have also become a mainstay in phenology. Results from different methods often vary, so there is still a need to better understand how digital cameras record autumn phenology, especially in comparison with ground-based observations (Keenan et al. 2014). This study compared autumn phenology derived from direct ground observations with upward-facing fisheye photography, in the context …


Improving Logistics Efficiency Through Collaborative Truck Routing, Patrick Dougherty May 2021

Improving Logistics Efficiency Through Collaborative Truck Routing, Patrick Dougherty

Industrial Engineering Undergraduate Honors Theses

The logistics industry is among the world’s largest and most essential. Specifically, trucking is a massive component of the modern logistics system. In 2012, truck transportation carried 68% of all freight tonnage in the U.S. However, trucking currently faces significant problems with efficiency and sustainability. Of all miles driven by trucks yearly in the U.S., 25% are driven with empty loads and 36% are driven with underutilized loads. In addition to this economic inefficiency, the industry faces social and environmental challenges. Driver turnover rates are near 100%, and trucking accounts for a significant level of greenhouse gas emissions. One potential …


The Search For Life: Exoplanet Detection With Deep Learning, Natasha Scannell May 2021

The Search For Life: Exoplanet Detection With Deep Learning, Natasha Scannell

Theses and Dissertations

The discovery of new exoplanets, planets outside of our solar system, is essential for increasing our understanding of the universe. Exoplanets capable of harboring life are particularly of interest. Over 600 GB of data was collected by the Kepler Space Telescope, and about 30 GB is being collected each day by the Transiting Exoplanet Survey Satellite since its launch in 2018. Traditional methods of experts examining this data manually are no longer tractable; automation is necessary to accomplish the task of vetting all of this data to identify planet candidates from astrophysical false positives.

Previous state-of-the-art models, Astronet and Exonet, …


Addressing Diversity, Equality, Inclusion And Discrimination By Modeling, Selecting And Ordering Actions, Praneeth Keshav Madabhushi May 2021

Addressing Diversity, Equality, Inclusion And Discrimination By Modeling, Selecting And Ordering Actions, Praneeth Keshav Madabhushi

Theses and Dissertations

In the current era, Diversity, Equality, and Inclusion (DEI) are often not sufficiently addressed due to bias against certain people or unjust stereotypes or simply an inadequate understanding of the value of DEI. Not addressing DEI sufficiently leads to multiple problems including lawsuits, costly settlements, departure of valuable employees, reduced employee productivity, shortage of qualified workforce, and unjust hiring, compensation, and work-distribution practices. Initiatives to address DEI often fail or risk being ineffective. In this thesis, advances in modeling and search have been exploited to address DEI.


Road Accessibility From County Seat Under Flooding: Hampton, Newport News, James City, Poquoson, Williamsburg, York, Accomack, Northampton, Alexandria, Fairfax, Gloucester, Mathews, Middlesex, Molly Mitchell, Jessica Hendricks, Daniel Schatt, Marcia Berman May 2021

Road Accessibility From County Seat Under Flooding: Hampton, Newport News, James City, Poquoson, Williamsburg, York, Accomack, Northampton, Alexandria, Fairfax, Gloucester, Mathews, Middlesex, Molly Mitchell, Jessica Hendricks, Daniel Schatt, Marcia Berman

Data

The impacts of recurrent flooding on roadways present challenging social and economic considerations for all coastal jurisdictions. Maintenance, public and private accessibility, evacuation routes, and emergency services are just a few of the common themes local governments are beginning to address for low-lying roadways currently known to flood. The project implements a protocol developed by CCRM to analyze the level at which road flooding may impact communities and their ability to reach key locations at periodic intervals; through the year 2100 in coastal Virginia. Using a network analysis, road accessibility is evaluated at different levels of flooding (at 0.1 meter …


Revolt Pimenov Taught Us How To Be Scientists, Vladik Kreinovich May 2021

Revolt Pimenov Taught Us How To Be Scientists, Vladik Kreinovich

Departmental Technical Reports (CS)

In 2021, we are celebrating the 90th birthday of Revolt Pimenov, a specialist in space-time geometry. He was my teacher. In this article, I am trying to summarize what he taught to his students.


Development Of Nucleic Acid Aptamers To Inhibit Bacterial Efflux Pumps, Emilie A. Moses May 2021

Development Of Nucleic Acid Aptamers To Inhibit Bacterial Efflux Pumps, Emilie A. Moses

Honors Theses

Multidrug resistance in bacteria, defined as the ability of a bacterial strain to resist the killing effects of more than one antibiotic, represents a major threat to global healthcare. Every year in the United States, two million people are infected with a multidrug resistant strain of bacteria. According to the Center for Disease Control (CDC), out of those two million people, about 35,000 will die from their infection. Thus, these multidrug resistant diseases are considered by the CDC to be the most dangerous diseases in the world. While multidrug resistance can occur through several different mechanisms, a major contributor to …