Digital Commons Network^™

The Structure, Oxidation States, And Energetics Of Co Nanoparticles On Ceo2(111): An Stm And Dft Study, Md Saeedur Rahman, Nishan Paudyal, Linze Du Hill, Jing Zhou, Ye Xu

Faculty Publications

Co nanoparticles (NPs) dispersed on ceria have been widely studied as active catalytic materials for many industrially relevant reactions. The detailed nature of such particles and the factors affecting their interaction with ceria remain to be better understood. In this study, a very low coverage (∼0.02 ML) of Co is deposited on a model CeO2(111) thin-film surface and is examined using scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS). The Co NPs that nucleate on terrace sites grow with coverage in this range to a maximum size of ca. 40 Co atoms, with an average diameter and height of …

Variations Of Aquaculture Structures, Operations, And Maintenance With Increasing Ocean Energy, Kevin G. Heasman, Nicholas Scott, Tyler Sclodnick, Michael Chambers, Barry Costa-Pierce, Tobias Dewhurst, Wolf Isbert, Bela H. Buck

Faculty Publications

Aquaculture in exposed and/or distant ocean sites is an emerging industry and field of study that addresses the need to improve food security along with the challenges posed by expansion of urban and coastal stakeholders into nearshore and sheltered marine waters. This move necessitates innovative solutions for this industry to thrive in high-energy environments. Some innovative research has increased understanding of the physics, hydrodynamics, and structural requirements enabling the development of appropriate systems. The blue mussel (Mytilus edulis), the New Zealand green shell or green lipped mussel (Perna canaliculus), and the Pacific Oyster (Magallana gigas), are the primary targets for …

Covid-19 Pandemic And Ghana’S Economy: A Deep Dive Into Economic Indicators, Williams Kwasi Peprah, Isaac Anowuo [email protected], Ebenezer Owusu-Yeboah, Daniel Adofo Kwakye Ameyaw, Lucile Sabas

Faculty Publications

The study presents an in-depth analysis of the COVID-19 pandemic’s effect on Ghana’s gross domestic product (GDP), balance of payments and international investment position (BPM6), and inflation (INFL). Employing a pre-and post-COVID-19 comparison (2017-2022) through repeated measures ANOVA and tests of between-subject effects, it investigates whether the government’s economic performance was significantly impacted. Key findings show a notable decrease in GDP and BPM6, alongside a major increase in inflation rates post-pandemic. The study concludes that the COVID-19 pandemic had a statistically significant impact on Ghana’s economic performance in terms of GDP and BPM6, but not inflation. Recommendations include implementing economic …

Evaluation And Lessons Learned From The Dissemination And Implementation Science Scholars Program In The National Cancer Prevention And Control Research Network, Daniela B. Friedman, Cam Escoffery, Elaine H. Morrato, Cynthia A. Thomson, Courtney N. Petagna, Freda Allyson Hucek, Mary Wangen, Aubrey Villalobos, James R. Hébert Scd, Samuel Noblet, Mayank Sakhuja, David O. Garcia, Jennifer L. Cruz, Stephanie B. Wheeler

Faculty Publications

Background:

The Centers for Disease Control and Prevention (CDC)-funded Cancer Prevention and Control Research Network (CPCRN) has been a leader in cancer-related dissemination & implementation (D&I) science. Given increased demand for D&I research, the CPCRN Scholars Program launched in 2021 to expand the number of practitioners, researchers, and trainees proficient in cancer D&I science methods. Methods:

The evaluation was informed by a logic model and data collected through electronic surveys. Through an application process (baseline survey), we assessed scholars’ competencies in D&I science domains/subdomains, collected demographic data, and asked scholars to share proposed project ideas. We distributed an exit survey …

Advancing Heteroanionicity In Zintl Phases: Crystal Structures, Thermoelectric And Magnetic Properties Of Two Quaternary Semiconducting Arsenide Oxides, Eu8zn2as6o And Eu14zn5as12o, Mohd Ishtiyak, Spencer R. Watts, Bhushan Thipe, Frank Womack, Philip Adams, Xiaojian Bai, David P. Young, Svilen Bobev, Sviatoslav Baranets

Faculty Publications

Two novel quaternary oxyarsenides, Eu8Zn2As6O and Eu14Zn5As12O, were synthesized through metal flux reactions, and their crystal structures were established by single-crystal X-ray diffraction methods. Eu8Zn2As6O crystallizes in the orthorhombic space group Pbca, featuring polyanionic ribbons composed of corner-shared triangular [ZnAs3] units, running along the [100] direction. The structure of Eu14Zn5As12O crystallizes in the monoclinic space group P2/m and its anionic substructure can be described as an infinite “ribbonlike” chain comprised of [ZnAs3] trigonal-planar units, although the structural complexity here is greater and also amplified by disorder on multiple crystallographic positions. In both structures, the O^2- anion occupies an octahedral …

Joint Subarray Acoustic Tweezers Enable Controllable Cell Translation, Rotation, And Deformation, Liang Shen, Zhenhua Tian, Kaichun Yang, Joseph Rich, Jianping Xia, Neil Upreti, Jinxin Zhang, Chuyi Chen, Nanjing Hao, Zhichao Pei, Tony Jun Huang

Faculty Publications

Contactless microscale tweezers are highly effective tools for manipulating, patterning, and assembling bioparticles. However, current tweezers are limited in their ability to comprehensively manipulate bioparticles, providing only partial control over the six fundamental motions (three translational and three rotational motions). This study presents a joint subarray acoustic tweezers platform that leverages acoustic radiation force and viscous torque to control the six fundamental motions of single bioparticles. This breakthrough is significant as our manipulation mechanism allows for controlling the three translational and three rotational motions of single cells, as well as enabling complex manipulation that combines controlled translational and rotational motions. …

Coastal Wetlands In The Anthropocene, John Day, Edward Anthony, Robert Costanza, Douglas Edmonds, Joel Gunn, Charles Hopkinson, Michael E. Mann, James Morris, Michael Osland, Tracy Quirk, Andre Rovai, John Rybczyk, Thomas Spencer, Jessica Stephens, Jaia Syvitski, Robert Twilley, Jenneke Visser, John R. White

Faculty Publications

We review the functioning and sustainability of coastal marshes and mangroves. Urbanized humans have a 7,000-year-old enduring relationship to coastal wetlands. Wetlands include marshes, salt flats, and saline and freshwater forests. Coastal wetlands occur in all climate zones but are most abundant in deltas. Mangroves are tropical, whereas marshes occur from tropical to boreal areas. Quantification of coastal wetland areas has advanced in recent years but is still insufficiently accurate. Climate change and sea-level rise are predicted to lead to significant wetland losses and other impacts on coastal wetlands and the humans associated with them. Landward migration and coastal retreat …

Hydrodynamic Exposure – On The Quest To Deriving Quantitative Metrics For Mariculture Sites, Oliver Lojek, Nils Goseberg, Heidi Moe Føre, Tobias Dewhurst, Thea Bölker, Kevin Gerald Heasman, Bela H. Buck, David W. Fredriksson, Samuel Rickerich

Faculty Publications

This work attempts to define metrics for hydrodynamic exposure, using known oceanographic variables to provide a universal site assessment method for mariculture structures. Understanding environmental conditions driving open-ocean mariculture siting is crucial in establishing consistent ocean governance, minimizing adverse environmental impacts, and facilitating economically sustainable farm operations. To provide a metric of oceanic conditions and associated requirements for structural design and operation of aquaculture systems, six Exposure Indices (EI) are proposed that consider physical energy levels related to hydrodynamic forces at a site. Four of the proposed indices consider only environmental conditions, while the other two also consider the dimensions …

Personalized Learning Path Problem Variations: Computational Complexity And Ai Approaches, Sean A. Mochocki, Mark Reith, Brett J. Borghetti, Gilbert L. Peterson, John Jasper, Laurence D. Merkle

Faculty Publications

E-learning courses often suffer from high dropout rates and low student satisfaction. One way to address this issue is to use personalized learning paths (PLPs), which are sequences of learning materials that meet the individual needs of students. However, creating PLPs is difficult and often involves combining knowledge graphs (KGs), student profiles, and learning materials. Researchers typically assume that the problem of creating PLPs belong to the nondeterministic polynomial (NP)-hard class of computational problems. However, previous research in this field has neither defined the different variations of the PLP problem nor formally established their computational complexity. Without clear definitions of …

Influence Of Redox Engineering On The Trade-Off Relationship Between Thermopower And Electrical Conductivity In Lanthanum Titanium Based Transition Metal Oxides, Mohammad El Loubani, Gene Yang, Seyed Morteza Taghavi Kouzehkanan, Tae-Sik Oh, Santosh Kiran Balijepalli, Dongkyu Lee

Faculty Publications

Discovery of new materials plays a critical role in developing advanced high-temperature thermoelectric (TE) applications. Transition metal oxides (TMOs) are one of the attractive candidates for high-temperature TE applications due to their thermal and chemical stability. However, the trade-off relationship between thermopower (S) and electrical conductivity (σ) limits the maximum attainable power factor (PF), thereby hindering improvements in TE conversion efficiency. To overcome this trade-off relationship, the emerging approach of the redox-driven metal exsolution in TMOs shows promise in improving both S and σ. However, the effect of metal exsolution with different particle sizes and …

Data-Driven Sparse Sensor Placement Optimization On Wings For Flight-By-Feel: Bioinspired Approach And Application, Alex C. Hollenbeck, Atticus J. Beachy, Ramana V. Grandhi, Alexander M. Pankonien

Faculty Publications

Flight-by-feel (FBF) is an approach to flight control that uses dispersed sensors on the wings of aircraft to detect flight state. While biological FBF systems, such as the wings of insects, often contain hundreds of strain and flow sensors, artificial systems are highly constrained by size, weight, and power (SWaP) considerations, especially for small aircraft. An optimization approach is needed to determine how many sensors are required and where they should be placed on the wing. Airflow fields can be highly nonlinear, and many local minima exist for sensor placement, meaning conventional optimization techniques are unreliable for this application. The …

Exploring The Association Between Parenting Stress And A Child’S Exposure To Positive Childhood Experiences (Pces), Elizabeth Crouch Ph.D., Elizabeth Radcliff, Monique J. Brown Ph.D., Mph, Peiyin Hung Ph.D

Faculty Publications

High levels of parenting stress, defined as a caregiver or parent feeling stress or aggravation from parenting, has been previously shown to be associated with an increased likelihood of neglect, child maltreatment, and household dysfunction: adverse childhood experiences (ACEs). Despite the potential mitigation of positive childhood experiences (PCEs) on ACEs, prior studies on the increased likelihood of a child experiencing ACEs due to parenting stress have left a critical question unanswered: whether high parenting stress may decrease a child’s likelihood of experiencing PCEs. We analyzed the 2019–2020 National Survey of Children’s Health to examine whether higher levels of parenting stress …

Rootzone Soil Moisture Dynamics Using Terrestrial Water-Energy Coupling, Vinit Sehgal, Binayak P. Mohanty, Rolf H. Reichle

Faculty Publications

A lack of high-density rootzone soil moisture (θRZ) observations limits the estimation of continental-scale, space-time contiguous θRZ dynamics. We derive a proxy of daily θRZ dynamics — active rootzone degree of saturation (SRZ) — by recursive low-pass (LP) filtering of surface soil moisture (θS) within a terrestrial water-energy coupling (WEC) framework. We estimate the LP filter parameters and WEC thresholds for the piecewise-linear coupling between SRZ and evaporative fraction (EF) at remote sensing and field scale over the Contiguous U.S. We use θS from the Soil Moisture Active-Passive (SMAP) satellite and 218 in-situ stations, with EF from the Moderate Resolution …

Predictability Limit Of The 2021 Pacific Northwest Heatwave From Deep‐Learning Sensitivity Analysis, P. Trent Vonich, Gregory J. Hakim

Faculty Publications

The traditional method for estimating weather forecast sensitivity to initial conditions uses adjoint models, which are limited to short lead times due to linearization around a control forecast. The advent of deep‐learning frameworks enables a new approach using backpropagation and gradient descent to iteratively optimize initial conditions, minimizing forecast errors. We apply this approach to the June 2021 Pacific Northwest heatwave using the GraphCast model, yielding over 90% reduction in 10‐day forecast errors over the Pacific Northwest. Similar improvements are found for Pangu‐Weather model forecasts initialized with the GraphCast‐derived optimal, suggesting that model error is an unimportant part of the …

Numerically Efficient Coherent Mode Representations For Partially Coherent Beams With Separable Phases, Milo W. Hyde, Carolina Rickenstorff

Faculty Publications

We present a method to numerically compute the coherent mode representations (CMRs) for partially coherent beams with separable phases. This special class of random light field has the ability to self-focus and is resistant to turbulence-induced degradation, making it potentially useful in applications such as optical communications. We validate our method by generating (in simulation) two such sources from the literature using their computed CMRs. Lastly, we conclude with a summary of our approach and a discussion of potential applications.

Social Isolation And Loneliness Prevention Among Rural Older Adults Aging-In-Place: A Needs Assessment, Jodi L. Southerland, Shimin Zheng, Kayla Dodson, Erin Mauck, Juanita-Dawne R. Bacsu, Monique J. Brown Ph.D., Mph, Jeremy Holloway, Steffi M. Kim, Ayse Malatyali, Matthew Lee Smith

Faculty Publications

Introduction: The adverse effects of social isolation and loneliness (SI/L) have been documented among older adults in rural communities and contribute to poor health outcomes, premature disability and mortality, and increased burden on the healthcare system. The identification of factors contributing to SI/L among older adults can build the foundation for rural policymakers and leaders to allocate resources and develop tailored strategies more efficiently. The purpose of this article is to describe findings from a needs assessment designed to understand local factors that contribute to SI/L among rural older adults in a county in Northeast Tennessee. Findings from the needs …

The Overlooked First Intercostal Ligament: Does It Help To Stabilize The Weberian Apparatus?, Jake Leyhr, Tatjana Haitina, Nathan C. Bird

Faculty Publications

The Weberian apparatus is a novel hearing adaptation that facilitates increased hearing sensitivity in otophysan fishes. The apparatus is a complex system composed of modifications to anterior vertebral elements, the inner ear, and the swim bladder. A critical piece of the system that often receives minor attention are the various ligaments that bridge these three regions. The most famous of the ligaments is the interossicular ligament, which connects the Weberian ossicle chain (scaphium–intercalarium–tripus). Several other ligaments are present, including the suspensor (tripus to parapophysis 4) and the triple ligament (tripus–os suspensorium–tunica externa). Here, by combining diffusible iodine-based contrast enhancement (DICE) …

Physical Development And Sociocultural Context Influences On Children’S Physical Activity, Alessandro Hervaldo Nicolai Ré, Maria Teresa Cattuzzo, David F. Stodden Ph.D., Guilherme Dos Santos, Albert Lucas Olinto Tertuliano, Carlos Bandeira De Mello Monteiro, Diogo Henrique Constantino Coledam, Anthony David Okely

Faculty Publications

Objective:

To examine the predictive strength of cardiorespiratory fitness (CRF), motor competence (MC), maternal educational status, and parental perception of their children’s favorite leisure activities for meeting physical activity (PA) guidelines of each gender among children aged 3–6 years.

Methods: This is a cross-sectional study with 367 preschoolers (53% girls), assessing CRF (PREFIT 20m shuttle run), MC (battery of motor skills), PA (accelerometry), maternal education and parental perception of children’s preferred leisure (questionnaires). Factorial analysis of covariance, multiple logistic regression, and chi-square tests were conducted.

Results: In both genders, CRF was associated with meeting PA guidelines (girls: odds ratio [OR] …

Distributed Software Build Assurance For Software Supply Chain Integrity, Ken Lew, Arijet Sarker, Simeon Wuthier, Jinoh Kim

Faculty Publications

Computing and networking are increasingly implemented in software. We design and build a software build assurance scheme detecting if there have been injections or modifications in the various steps in the software supply chain, including the source code, compiling, and distribution. Building on the reproducible build and software bill of materials (SBOM), our work is distinguished from previous research in assuring multiple software artifacts across the software supply chain. Reproducible build, in particular, enables our scheme, as our scheme requires the software materials/artifacts to be consistent across machines with the same operating system/specifications. Furthermore, we use blockchain to deliver the …

Measuring The Behavior Of The Acoustic Standing Wave Exiting A Flue Organ Pipe, Lauren Krebs Schefter, Whitney L. Coyle, Eric Rokni, Ashley Cannaday

Faculty Publications

Correctly predicting the playing frequencies of a musical instrument is dependent on the length of the resonator with the addition of an end correction. There are multiple theories describing this end correction, perhaps the simplest being that the end correction of a pipe is a physical extension of the sinusoidal pressure standing wave inside the pipe. However, recent optical imaging of the flow in a flue organ pipe found an unexpected exponential decay of pressure just outside of the pipe. This work looks to validate those findings acoustically. A flue organ pipe was played at the 1st, 5th, and 7th …

Journalists Under Attack: Global Perspectives On Threats, Violence And Impunity, Edward L. Carter

Faculty Publications

Journalists are under attack. The digital and physical intimidation and injuries cause harm to not only journalists themselves but also the societies they serve. Society suffers when journalists are silenced because the valuable information they would have provided is prevented from entering the public consciousness. Attacks on journalists are largely met with indifference or ineffective efforts to achieve justice. This impunity emboldens others. This book originated with an international online symposium in 2022 in which scholars and practitioners from around the globe met to discuss not only the problem but also possible solutions.

Closed-Loop Adaptive Optics In The Presence Of Speckle And Weak Scintillation, Derek J. Burrell, Mark F. Spencer, Ronald G. Driggers

Faculty Publications

In this paper, we show that speckle averaging helps to improve adaptive-optics (AO) performance in closed loop as a result of reduced measurement error associated with a Shack–Hartmann wavefront sensor (SHWFS); however, this reduction is rendered ineffective with increasing beacon anisoplanatism. We do so operating in a weak-scintillation regime, where the SHWFS offers robust performance, and using in-plane translation of the illuminated rough surface to accomplish frame-to-frame speckle diversity. Understanding these trade-space limitations is critical when performing AO with non-cooperative, extended-source beacons.

A Comparison Of Gaussian Processes And Polynomial Chaos Emulators In The Context Of Haemodynamic Pulse–Wave Propagation Modelling, L. Mihaela Paun, Mitchel J. Colebank, Dirk Husmeier

Faculty Publications

Computational modelling of the cardiovascular system is a promising future direction for patient-specific healthcare. However, the computational cost of these simulators is a bottleneck for their practical use in clinic for real-time digital twins. Emulation can overcome this, yet an extensive investigation into cardiovascular emulators is warranted. In this study, we emulate two one-dimensional haemodynamics models of the pulmonary circulation and compare two common emulation strategies: Gaussian processes (GPs) and polynomial chaos expansions (PCEs). We start by reducing the parameter space of the models through global sensitivity analysis, and then compare both emulation strategies using a multivariate, time-series output …

Aspect-Ratio-Dependent Heat Transport By Baroclinic Acoustic Streaming, Jacques Abdul Massih, Remil Mushthaq, Guillaume Michel, Gregory P. Chini

Faculty Publications

Standing acoustic waves have been known to generate Eulerian time-mean ‘streaming’ flows at least since the seminal investigation of Lord Rayleigh in the 1880s. Nevertheless, a recent body of numerical and experimental evidence has shown that inhomogeneities in the ambient density distribution lead to much faster flows than arise in classical Rayleigh streaming. The emergence of these unusually strong flows creates new opportunities to enhance heat transfer in systems in which convective cooling cannot otherwise be easily achieved. To assess this possibility, a theoretical study of acoustic streaming in an ideal gas confined in a rectangular channel with top and …

Aspect-Ratio-Dependent Heat Transport By Baroclinic Acoustic Streaming, Jacques Abdul Massih, Remil Mushthaq, Guillaume Michel, Gregory P. Chini

Faculty Publications

Standing acoustic waves have been known to generate Eulerian time-mean ‘streaming’ flows at least since the seminal investigation of Lord Rayleigh in the 1880s. Nevertheless, a recent body of numerical and experimental evidence has shown that inhomogeneities in the ambient density distribution lead to much faster flows than arise in classical Rayleigh streaming. The emergence of these unusually strong flows creates new opportunities to enhance heat transfer in systems in which convective cooling cannot otherwise be easily achieved. To assess this possibility, a theoretical study of acoustic streaming in an ideal gas confined in a rectangular channel with top and …

Examination Of Photoinduced Radicals In Two Crystal Forms Of Triphenylamine Bis-Urea Macrocycles, Md Faizul Islam, Gamage Isuri P. Wijesekera, Anmon J. Sindt, Mark D. Smith, Linda S. Shimizu

Faculty Publications

This study probes two solvates of triphenylamine (TPA) bis-urea macrocycle 1 and their activated structures to evaluate their maximum photoinduced radicals (PIRs), the subsequent decay of the radicals, and their regeneration. The hierarchical assembly of TPAs shows promise in stabilizing less substituted derivatives, potentially expanding the utility of TPAs that lack stabilizing para-substituents. Single crystal structure analysis reveals that host 1 adopts a planar conformation with the two ureas pointing in opposite directions when dimethoxyethane (DME) is encapsulated within the channel. Whereas previously, 1 adopted a bowl-shaped conformation with the two ureas pointing in the same direction (syn …

Examination Of Photoinduced Radicals In Two Crystal Forms Of Triphenylamine Bis-Urea Macrocycles, Md Faizul Islam, Gamage Isuri P. Wijesekera, Ammon J. Sindt, Mark D. Smith, Linda S. Shimizu

Faculty Publications

This study probes two solvates of triphenylamine (TPA) bis-urea macrocycle 1 and their activated structures to evaluate their maximum photoinduced radicals (PIRs), the subsequent decay of the radicals, and their regeneration. The hierarchical assembly of TPAs shows promise in stabilizing less substituted derivatives, potentially expanding the utility of TPAs that lack stabilizing para-substituents. Single crystal structure analysis reveals that host 1 adopts a planar conformation with the two ureas pointing in opposite directions when dimethoxyethane (DME) is encapsulated within the channel. Whereas previously, 1 adopted a bowl-shaped conformation with the two ureas pointing in the same direction (syn …

Hydrogen Underground Storage For Grid Electricity Storage: An Optimization Study On Techno-Economic Analysis, Yunzhi Chen, Daniel Hill, Blake Billings, John Hedengren, Kody Powell

Faculty Publications

This study performs a techno-economic analysis of hydrogen underground storage systems for grid electricity storage, evaluating their economic viability at the plant scale using dynamic optimization. It explores the feasibility of various system configurations and revenue models in the context of volatile electricity prices and the necessity for multiple revenue streams. The hypothesis tested is that large-scale hydrogen storage, despite its low round-trip efficiency, can be economically viable with the right mix of revenue streams. This study uses scenario-based analysis to assess the impacts of different system configurations, including engaging in time-shifting arbitrage, ancillary service markets and blending hydrogen with …

The Provenance Of A Pali- And Thai-Language Manuscript At The Rollins College Library: A Buddhist Book Of Merit And Its Long Journey From Southeast Asia To America, Wenxian Zhang

Faculty Publications

Through researching the provenance of a Buddhist manuscript written in the Pali and Thai languages currently held at Rollins, this article seeks to answer the question of how a religious document created in Thailand ended up in a liberal arts college library in America. Regarded as an act of devotion by many Buddhist followers in Southeast Asia, the use of folding manuscripts (samut khoi) has been observed for centuries. The folding manuscripts served as handbooks and chanting manuals for Buddhist monks, who often recited in religious ceremonies while paying tributes to the deceased, with the hope of reincarnation in a …

The Role Of Benthic Fluxes In Acidifying The Bottom Waters In The Northern Gulf Of Mexico Hypoxic Zone Based On An Updated Water Column Biogeochemical-Seabed Diagenetic And Sediment Transport Model, Dongxiao Yin, Linlin Cui, Courtney K. Harris, Julia M. Moriarty, Hannah Beck, Kanchan Maiti

Faculty Publications

The seabed and the water column are tightly coupled in shallow coastal environments. Numerical models of seabed-water interaction provide an alternative to observational studies that require concurrent measurements in both compartments, which are hard to obtain and rarely available. Here, we present a coupled model that includes water column biogeochemistry, seabed diagenesis, sediment transport and hydrodynamics. Our model includes realistic representations of biogeochemical reactions in both seabed and water column, and fluxes at their interface. The model was built on algorithms for seabed-water exchange in the Regional Ocean Modeling System and expanded to include carbonate chemistry in seabed. The updated …