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Extracting High-Molecular Weight Dna From Cyanobacteria Using Promega's Wizard® Hmw Dna Extraction Kit With A Modified Protocol, Metis, Megan A. Hept, Lesley H. Greene Jan 2023

Extracting High-Molecular Weight Dna From Cyanobacteria Using Promega's Wizard® Hmw Dna Extraction Kit With A Modified Protocol, Metis, Megan A. Hept, Lesley H. Greene

Chemistry & Biochemistry Faculty Publications

Extraction of high molecular weight (HMW) DNA for long read sequencing with little to no fragmentation and high purity is difficult to acquire from cyanobacterial species. Here we describe a modified method of extraction using Promega's Wizard® HMW DNA Extraction Kit to acquire high molecular weight DNA from cyanobacterial species. The protocol used in the kit is the “3.D. Isolating HMW DNA from Gram-Positive and Gram-Negative Bacteria” protocol. During a key step in the protocol, the lingering remnants of the mucilage layer of the cyanobacterial species is removed, preventing it from sticking to the DNA pellet produced. This customized modification …

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Abiotic Stress Mitigation: A Case Study From 21 Trials Using A Natural Organic Matter Based Biostimulant Across Multiple Geographies, Rachel L. Sleighter, Terry Hanson, David Holden, Kristen M. Richards Jan 2023

Abiotic Stress Mitigation: A Case Study From 21 Trials Using A Natural Organic Matter Based Biostimulant Across Multiple Geographies, Rachel L. Sleighter, Terry Hanson, David Holden, Kristen M. Richards

Chemistry & Biochemistry Faculty Publications

Crop productivity and yields can be greatly diminished by abiotic stress events including drought, extreme temperatures, excess moisture, and saline irrigation water. Multiple stressors occurring simultaneously can further exacerbate the strain on plants. Various types of biostimulants have been shown to mitigate abiotic stress and here, the results of 21 trials on corn, wheat, soybean, and various high-value crops are discussed in the context of the abiotic stress that either occurred naturally or was experimentally induced. Treatments in these trials included stressed and non-stressed plants, as well as either an untreated control or grower standard fertilizer applications alone and in …

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Coastal Science For Resilience And Management At The Cape Hatteras National Seashore, Nc, Usa, Michael J. Flynn, Thomas R. Allen, Meaghan E. Johnson, David E. Hallac Jan 2023

Coastal Science For Resilience And Management At The Cape Hatteras National Seashore, Nc, Usa, Michael J. Flynn, Thomas R. Allen, Meaghan E. Johnson, David E. Hallac

Political Science & Geography Faculty Publications

National seashores are cherished public lands with rich environmental, cultural, and historic resources. The Cape Hatteras National Seashore is one such coastal asset that is both bountiful yet vulnerable, with historic lighthouses, critical habitats, and recreational amenities alike facing threats of sea-level rise and continual storm and climate change impacts. Over 3 million visitors to the Seashore in 2021 set an annual visitation record. Historic resources such as the Bodie Island Lighthouse and Ocracoke Lighthouse are among the most visited sites, yet these assets are also among those most vulnerable to flooding, compromised structural integrity, and reduced accessibility. Future challenges …

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Speculative Futures On Chatgpt And Generative Artificial Intelligence (Ai): A Collective Reflection From The Educational Landscape, Aras Bozkurt, Junhong Xiao, Sarah Lambert, Angelica Pazurek, Helen Crompton, Suzan Koseoglu, Robert Farrow, Melissa Bond, Chrissi Nerantzi, Sarah Honeychurch, Maha Bali, Jon Dron, Kamran Mir, Bonnie Stewart, Eamon Costello, Jon Mason, Christian M. Stracke, Enilda Romero-Hall, Apostolos Koutropoulos, Cathy Mae Toquero, Lenandlar Singh, Ahmed Tlili, Kyungmee Lee, Mark Nichols, Ebba Ossiannilsson, Mark Brown, Valerie Irvine, Juliana Elisa Raffaghelli, Gema Santos-Hermosa, Orna Farrell, Taskeen Adam, Ying Li Thong, Sunagul Sani-Bozkurt, Ramesh C. Sharma, Stefan Hrastinski, Petar Jandrić Jan 2023

Speculative Futures On Chatgpt And Generative Artificial Intelligence (Ai): A Collective Reflection From The Educational Landscape, Aras Bozkurt, Junhong Xiao, Sarah Lambert, Angelica Pazurek, Helen Crompton, Suzan Koseoglu, Robert Farrow, Melissa Bond, Chrissi Nerantzi, Sarah Honeychurch, Maha Bali, Jon Dron, Kamran Mir, Bonnie Stewart, Eamon Costello, Jon Mason, Christian M. Stracke, Enilda Romero-Hall, Apostolos Koutropoulos, Cathy Mae Toquero, Lenandlar Singh, Ahmed Tlili, Kyungmee Lee, Mark Nichols, Ebba Ossiannilsson, Mark Brown, Valerie Irvine, Juliana Elisa Raffaghelli, Gema Santos-Hermosa, Orna Farrell, Taskeen Adam, Ying Li Thong, Sunagul Sani-Bozkurt, Ramesh C. Sharma, Stefan Hrastinski, Petar Jandrić

Teaching & Learning Faculty Publications

While ChatGPT has recently become very popular, AI has a long history and philosophy. This paper intends to explore the promises and pitfalls of the Generative Pre-trained Transformer (GPT) AI and potentially future technologies by adopting a speculative methodology. Speculative future narratives with a specific focus on educational contexts are provided in an attempt to identify emerging themes and discuss their implications for education in the 21st century. Affordances of (using) AI in Education (AIEd) and possible adverse effects are identified and discussed which emerge from the narratives. It is argued that now is the best of times to define …

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Commentary On Thematic Special Issue: Seeing Self-Based Methodology Through A Philosophical Lens, Elizabeth Suazo-Flores, Signe E. Kastberg, Melva Grant, Olive Chapman Jan 2023

Commentary On Thematic Special Issue: Seeing Self-Based Methodology Through A Philosophical Lens, Elizabeth Suazo-Flores, Signe E. Kastberg, Melva Grant, Olive Chapman

Teaching & Learning Faculty Publications

A mathematics teacher educator’s (MTE) use of self-based methodologies goes beyond developing MTE professional knowledge by contributing scholarly inquiry into MTE work. Existing discussions of MTEs’ use of self-based methodologies have provided descriptions of the methodologies and examples of their use by MTEs to unpack their practice. What is less clear is why MTEs elect to use self-based methodologies. Yet central to understanding and validating self-based methodologies as a means of developing knowledge in mathematics teacher education is understanding the aims of MTEs who use such methodologies. On the basis of author interviews, drafts, and final papers for this special …

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Preparing Undergraduates For The Post-Pandemic Workplace: Teams Of Education And Engineering Students Teach Engineering Virtually, Kristie S. Gutierrez, Jennifer Kidd, Min J. Lee, Krishnanand Kaipa, Orlando Ayala Jan 2023

Preparing Undergraduates For The Post-Pandemic Workplace: Teams Of Education And Engineering Students Teach Engineering Virtually, Kristie S. Gutierrez, Jennifer Kidd, Min J. Lee, Krishnanand Kaipa, Orlando Ayala

Teaching & Learning Faculty Publications

When schools and universities across the world transitioned online due to the COVID-19 pandemic, Ed+gineering, a National Science Foundation (NSF) project that partners engineering and education undergraduates to design and deliver engineering lessons to elementary students, also had to shift its hands-on lessons to a virtual format. Through the lens of social cognitive theory (SCT), this study investigates engineering and education students’ experiences during the shift to online instruction to understand how they perceived its influence on their learning. As a result of modifying their lessons for online delivery, students reported learning professional skills, including skills for teaching online and …

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Translanguaging, Multiliteracy, And Sociocultural Dynamics: Exploring Diasporic Identity And Belonging, Seongryeong Yu Jan 2023

Translanguaging, Multiliteracy, And Sociocultural Dynamics: Exploring Diasporic Identity And Belonging, Seongryeong Yu

Teaching & Learning Faculty Publications

This ethnographic study delves into the language and literacy practices of immigrant children in a public elementary school setting. The purpose of the study is to understand the role of multiliteracy in their learning, their ability to connect with the curriculum and instruction, and their sense of belonging within their peer groups, classrooms, and home countries. To explore how these children utilized their linguistic and cultural repertoires to engage in language and literacy activities in different contexts (Kwon, 2019), the study focused on 10-year-old students from various linguistic backgrounds, including Korean and Chinese students in a United States classroom. Through …

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Critical Friend Intimacy And Individual Transformations, Melva R. Grant, Signe E. Kastberg Jan 2023

Critical Friend Intimacy And Individual Transformations, Melva R. Grant, Signe E. Kastberg

Teaching & Learning Faculty Publications

We have been investigating how critical friendships develop and we found that our critical friendship evolved in ways that went beyond what is in the self-study teacher and teacher education practices (S-STEP) foundational research literature. We continue to wonder about the power of critical friendship for supporting individual transformation. This paper is an elaboration about the essence of critical friend intimacy and its complicity in influencing individual transformations by those in the relationship. We examined S-STEP literature to determine how critical friend intimacy is discussed and if others connected it to individual transformations. We found 13 refereed empirical S-STEP reports …

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New Frontiers In The Application Of Stable Isotopes To Ecological And Ecophysiological Research, Keith Alan Hobson (Editor), John P. Whiteman (Editor), Seth Newsome (Editor) Jan 2023

New Frontiers In The Application Of Stable Isotopes To Ecological And Ecophysiological Research, Keith Alan Hobson (Editor), John P. Whiteman (Editor), Seth Newsome (Editor)

Biological Sciences Faculty Books

This Research Topic aims to present cutting-edge applications of stable isotope methods to animal and plant ecology and ecophysiology.

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Unification And Division: A Theory Of Institutional Choices In Imperial China, Haiwen Zhou Jan 2023

Unification And Division: A Theory Of Institutional Choices In Imperial China, Haiwen Zhou

Economics Faculty Publications

Ancient China experienced various rounds of division and unification. Unification was maintained through economic and political institutions such as low tax rates to reduce peasant rebellions and the division of authority among government officials to reduce usurpation of power. A ruler’s choice of institutions to maintain unification is studied in a theoretical model. Interactions among external threats, internal rebellions by peasants, and usurpation of power by government officials are established. A higher level of external threats induces the ruler to choose a higher level of autonomy for government officials and a higher tax rate. That is, equilibrium probability of internal …

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Defending Ai-Based Automatic Modulation Recognition Models Against Adversarial Attacks, Haolin Tang, Ferhat Ozgur Catak, Murat Kuzlu, Evren Catak, Yanxiao Zhao Jan 2023

Defending Ai-Based Automatic Modulation Recognition Models Against Adversarial Attacks, Haolin Tang, Ferhat Ozgur Catak, Murat Kuzlu, Evren Catak, Yanxiao Zhao

Engineering Technology Faculty Publications

Automatic Modulation Recognition (AMR) is one of the critical steps in the signal processing chain of wireless networks, which can significantly improve communication performance. AMR detects the modulation scheme of the received signal without any prior information. Recently, many Artificial Intelligence (AI) based AMR methods have been proposed, inspired by the considerable progress of AI methods in various fields. On the one hand, AI-based AMR methods can outperform traditional methods in terms of accuracy and efficiency. On the other hand, they are susceptible to new types of cyberattacks, such as model poisoning or adversarial attacks. This paper explores the vulnerabilities …

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Enhancing Student Veterans' Self-Efficacy And Sense Of Belonging In A Targeted Learning Community: Four Years Of Qualitative Results, Anthony W. Dean, Cynthia Tomovic, Vukica Jovanovic, Kim E. Bullington Jan 2023

Enhancing Student Veterans' Self-Efficacy And Sense Of Belonging In A Targeted Learning Community: Four Years Of Qualitative Results, Anthony W. Dean, Cynthia Tomovic, Vukica Jovanovic, Kim E. Bullington

Engineering Technology Faculty Publications

Eight semesters of qualitative data, collected over four academic years, are presented from a project that resulted in the development of a student professional learning community of high-achieving, low-income engineering and engineering technology student veterans. In the context of this project, student veterans received academic, professional, and financial support that helped them to be successful in school and to prepare them for a career in the STEM workforce. As adult learners, students in this learning community were a vital part of the curriculum development which resulted in increasing the students’ interest and buy-in. Typically, adult learners have lower levels of …

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Outstanding Advantages, Current Drawbacks, And Significant Recent Developments In Mechanochemistry: A Perspective View, Silvina Pagola Jan 2023

Outstanding Advantages, Current Drawbacks, And Significant Recent Developments In Mechanochemistry: A Perspective View, Silvina Pagola

Chemistry & Biochemistry Faculty Publications

Although known since antiquity, mechanochemistry has remained dormant for centuries. Nowadays, mechanochemistry is a flourishing research field at the simultaneous stages of gathering data and (often astonishing) observations, and scientific argumentation toward their analysis, for which the combination of interdisciplinary expertise is necessary. Mechanochemistry’s implementation as a synthetic method is constantly increasing, although it remains far from being fully exploited, or understood on the basis of fundamental principles. This review starts by describing many remarkable advantages of mechanochemical reactions, simplifying and “greening” chemistry in solutions. This description is followed by an overview of the current main weaknesses to be addressed …

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More On The Demons Of Thermodynamics, Daniel P. Sheehan, Garret Moddel, James W. Lee Jan 2023

More On The Demons Of Thermodynamics, Daniel P. Sheehan, Garret Moddel, James W. Lee

Chemistry & Biochemistry Faculty Publications

No abstract provided.

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The Effect Of Metalation On Antimicrobial Piscidins Imbedded In Normal And Oxidized Lipid Bilayers, Ana Dreab, Craig A. Bayse Jan 2023

The Effect Of Metalation On Antimicrobial Piscidins Imbedded In Normal And Oxidized Lipid Bilayers, Ana Dreab, Craig A. Bayse

Chemistry & Biochemistry Faculty Publications

Metalation of the N-terminal Amino Terminal Cu(II)- and Ni(II)-binding (ATCUN) motif may enhance the antimicrobial properties of piscidins. Molecular dynamics simulations of free and nickelated piscidins 1 and 3 (P1 and P3) were performed in 3 : 1 POPC/POPG and 2.6 : 1 : 0.4 POPC/POPG/aldo-PC bilayers (POPC, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine: POPG, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol; aldo-PC, 1-palmitoyl-2-(9′-oxo-nonanoyl)-sn-glycero-3-phosphocholine) bilayer models. Nickel(II) binding decreases the conformation dynamics of the ATCUN motif and lowers the charge of the N-terminus to allow it to embed deeper in the bilayer without significantly changing the overall depth due to interactions of the charged half-helix …

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Mechanical Devices For Census And Detection Of Off-Host Larval Ticks (Acari: Ixodidae), Donald B. Thomas, Holly D. Gaff, Brenda Leal-Galvan Jan 2023

Mechanical Devices For Census And Detection Of Off-Host Larval Ticks (Acari: Ixodidae), Donald B. Thomas, Holly D. Gaff, Brenda Leal-Galvan

Biological Sciences Faculty Publications

Standard off-host tick census techniques are generally inefficient for larval stages. Also, such techniques expose the investigator to environmental hazards including tick bites. Mechanical devices are an option which were tested under field conditions for proof of concept and in side-by-side comparison to the standard techniques. The tick-vac collected more ticks than the legging technique, but with lower frequency of positive detections. It may have utility for sampling small areas, such as weedy corrals suspected of harboring ticks. Different configurations of tick-bots, robotic vehicles with flags, depended on intensive operator control to avoid obstacles, limiting operation to line of sight. …

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The Coral Bleaching Automated Stress System (Cbass): A Low Cost, Portable System For Standardized Empirical Assessments Of Coral Thermal Limits, Nicolas R. Evensen, Katherine E. Parker, Thomas A. Oliver, Stephen R. Palumbi, Cheryl A. Logan, James S. Ryan, Courtney N. Klepac, Gabriela Perna, Mark E. Warner, Christian R. Voolstra, Daniel J. Barshis Jan 2023

The Coral Bleaching Automated Stress System (Cbass): A Low Cost, Portable System For Standardized Empirical Assessments Of Coral Thermal Limits, Nicolas R. Evensen, Katherine E. Parker, Thomas A. Oliver, Stephen R. Palumbi, Cheryl A. Logan, James S. Ryan, Courtney N. Klepac, Gabriela Perna, Mark E. Warner, Christian R. Voolstra, Daniel J. Barshis

Biological Sciences Faculty Publications

Ocean warming is increasingly affecting marine ecosystems across the globe. Reef-building corals are particularly affected by warming, with mass bleaching events increasing in frequency and leading to widespread coral mortality. Yet, some corals can resist or recover from bleaching better than others. Such variability in thermal resilience could be critical to reef persistence; however, the scientific community lacks standardized diagnostic approaches to rapidly and comparatively assess coral thermal vulnerability prior to bleaching events. We present the Coral Bleaching Automated Stress System (CBASS) as a low-cost, open-source, field-portable experimental system for rapid empirical assessment of coral thermal thresholds using standardized temperature …

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Marine Heatwaves Modulate The Genotypic And Physiological Responses Of Reef-Building Corals To Subsequent Heat Stress, Kristen T. Brown, Amatzia Genin, Matheus A. Mello-Athayde, Ellie Bergstrom, Adriana Campili, Aaron Chai, Sophie G. Dove, Maureen Ho, Devin Rowell, Eugenia M. Sampayo, Veronica Z. Radice Jan 2023

Marine Heatwaves Modulate The Genotypic And Physiological Responses Of Reef-Building Corals To Subsequent Heat Stress, Kristen T. Brown, Amatzia Genin, Matheus A. Mello-Athayde, Ellie Bergstrom, Adriana Campili, Aaron Chai, Sophie G. Dove, Maureen Ho, Devin Rowell, Eugenia M. Sampayo, Veronica Z. Radice

Biological Sciences Faculty Publications

Back-to-back marine heatwaves in 2016 and 2017 resulted in severe coral bleaching and mortality across the Great Barrier Reef (GBR). Encouragingly, some corals that survived these events exhibit increased bleaching resistance and may represent thermally tolerant populations that can better cope with ocean warming. Using the GBR as a natural laboratory, we investigated whether a history of minimal (Heron Island) or severe (Lizard Island) coral bleaching in 2016 and 2017 equates to stress tolerance in a successive heatwave (2020). We examined the genetic diversity, physiological performance, and trophic plasticity of juvenile (<10 cm) and adult (>25 cm) corals of two common genera ( …

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Topologically Optimized Electrodes For Electroosmotic Actuation, Jianwen Sun, Jianyu Zhang, Ce Guan, Teng Zhou, Shizhi Qian, Yongbo Deng Jan 2023

Topologically Optimized Electrodes For Electroosmotic Actuation, Jianwen Sun, Jianyu Zhang, Ce Guan, Teng Zhou, Shizhi Qian, Yongbo Deng

Mechanical & Aerospace Engineering Faculty Publications

Electroosmosis is one of the most used actuation mechanisms for the microfluidics in the current active lab-on-chip devices. It is generated on the induced charged microchannel walls in contact with an electrolyte solution. Electrode distribution plays the key role on providing the external electric field for electroosmosis, and determines the performance of electroosmotic microfluidics. Therefore, this paper proposes a topology optimization approach for the electrodes of electroosmotic microfluidics, where the electrode layout on the microchannel wall can be determined to achieve designer desired microfluidic performance. This topology optimization is carried out by implementing the interpolation of electric insulation and electric …

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Comparison Of Dynamics Stability Testing Techniques With Magnetic Suspension Wind Tunnel Capabilities, Otoniel A. Ramirez, Mark Schoenenberger, David E. Cox, Colin P. Britcher Jan 2023

Comparison Of Dynamics Stability Testing Techniques With Magnetic Suspension Wind Tunnel Capabilities, Otoniel A. Ramirez, Mark Schoenenberger, David E. Cox, Colin P. Britcher

Mechanical & Aerospace Engineering Faculty Publications

Dynamic stability testing techniques currently utilized at NASA Langley Research Center (LaRC) are conducted in multiple facilities and consists of free flight, forced oscillation, and free-to-oscillate tests. The NASA/ODU Magnetic Suspension and Balance System (MSBS) has been recommissioned to explore its utility as an additional facility to expand the dynamic stability test capabilities currently available at NASA LaRC. Simulations were created to replicate each current test facility and method as closely as possible. Data collected from the simulated environments was corrupted with replicated noise sources of the different testing environments and then compared to real data collected during tests when …

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Patch-Wise Training With Convolutional Neural Networks To Synthetically Upscale Cfd Simulations, John P. Romano, Alec C. Brodeur, Oktay Baysal Jan 2023

Patch-Wise Training With Convolutional Neural Networks To Synthetically Upscale Cfd Simulations, John P. Romano, Alec C. Brodeur, Oktay Baysal

Mechanical & Aerospace Engineering Faculty Publications

This paper expands the authors’ prior work[1], which focuses on developing a convolutional neural network (CNN) model capable of mapping time-averaged, unsteady Reynold’s-averaged Navier-Stokes (URANS) simulations to higher resolution results informed by time-averaged detached eddy simulations (DES). The authors present improvements over the prior CNN autoencoder model that result from hyperparameter optimization, increased data set augmentation through the adoption of a patch-wise training approach, and the predictions of primitive variables rather than vorticity magnitude. The training of the CNN model developed in this study uses the same URANS and DES simulations of a transonic flow around several NACA 4-digit airfoils …

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Model Based Systems Engineering With A Docs-As-Code Approach For The Sealion Cubesat Project, Kevin Chiu, Sean Marquez, Sharanabasaweshwara Asundi Jan 2023

Model Based Systems Engineering With A Docs-As-Code Approach For The Sealion Cubesat Project, Kevin Chiu, Sean Marquez, Sharanabasaweshwara Asundi

Mechanical & Aerospace Engineering Faculty Publications

The SeaLion mission architecture team sought to create a model-based systems engineering approach to assist improving CubeSat success rates as well as for the SeaLion CubeSat project to guide an implementation for the flight software. This is important because university CubeSat teams are growing in number but often have untrained students as their core personnel. This was done using a document-as-code, or docs-as-code, approach. With this the team created tools for the systems architecture with the Mach 30 Modeling Language to create an architecture that is easy to learn and use even for newly admitted team members with little to …

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The Impact Of A Multidisciplinary Service-Learning Project On Engineering Knowledge And Professional Skills In Engineering In Engineering And Education Students, Stacie I. Ringleb, Pilar Pazos, Francisco Cima, Isaac Koduah Kumi, Orlando M. Ayala, Krishnanand Kaipa, Jennifer Jill Kidd, Kristie Gutierrez, Min Jung Lee Jan 2023

The Impact Of A Multidisciplinary Service-Learning Project On Engineering Knowledge And Professional Skills In Engineering In Engineering And Education Students, Stacie I. Ringleb, Pilar Pazos, Francisco Cima, Isaac Koduah Kumi, Orlando M. Ayala, Krishnanand Kaipa, Jennifer Jill Kidd, Kristie Gutierrez, Min Jung Lee

Mechanical & Aerospace Engineering Faculty Publications

A multidisciplinary service-learning project that involved teaching engineering to fourth and fifth graders was implemented in three sets of engineering and education classes to determine if there was an impact on engineering knowledge and teamwork skills in both the engineering and education students as well as persistence in the engineering students. Collaboration 1 paired a 100-level engineering Information Literacy class in Mechanical and Aerospace Engineering with a 300-level Educational Foundation class. Collaboration 2 combined a 300-level Electromechanical Systems class in Mechanical Engineering with a 400-level Educational Technology class. Collaboration 3 paired a 300-level Fluid Mechanics class in Mechanical Engineering Technology …

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Convolutional-Neural-Network-Based Des-Level Aerodynamic Flow Field Generation From Urans Data, John P. Romano, Oktay Baysal, Alec C. Brodeur Jan 2023

Convolutional-Neural-Network-Based Des-Level Aerodynamic Flow Field Generation From Urans Data, John P. Romano, Oktay Baysal, Alec C. Brodeur

Mechanical & Aerospace Engineering Faculty Publications

The present paper culminates several investigations into the use of convolutional neural networks (CNNs) as a post-processing step to improve the accuracy of unsteady Reynolds-averaged Navier–Stokes (URANS) simulations for subsonic flows over airfoils at low angles of attack. Time-averaged detached eddy simulation (DES)-generated flow fields serve as the target data for creating and training CNN models. CNN post-processing generates flow-field data comparable to DES resolution, but after using only URANS-level resources and properly training CNN models. This document outlines the underlying theory and progress toward the goal of improving URANS simulations by looking at flow predictions for a class of …

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Tuning Microwave Losses In Superconducting Resonators, Alex Gurevich Jan 2023

Tuning Microwave Losses In Superconducting Resonators, Alex Gurevich

Physics Faculty Publications

Performance of superconducting resonators, particularly cavities for particle accelerators and micro cavities and thin film resonators for quantum computations and photon detectors has been improved substantially by recent materials treatments and technological advances. As a result, the niobium cavities have reached the quality factors Q ~ 1011 at 1-2 GHz and 1.5 K and the breakdown radio-frequency (rf) fields H close to the dc superheating eld of the Meissner state. These advances raise the question whether the state-of-the-art cavities are close to the fundamental limits, what these limits actually are, and to what extent the Q and H limits …

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Cavity And Cryomodule Developments For Eic, R. A. Rimmer, E. Daly, J. Guo, J. Henry, J. Matalevich, H. Wang, S. Wang, D. Holmes, K. Smith, W. Xu, A. Zaltsman, B. Xiao, Subashini De Silva, Jean R. Delayen Jan 2023

Cavity And Cryomodule Developments For Eic, R. A. Rimmer, E. Daly, J. Guo, J. Henry, J. Matalevich, H. Wang, S. Wang, D. Holmes, K. Smith, W. Xu, A. Zaltsman, B. Xiao, Subashini De Silva, Jean R. Delayen

Physics Faculty Publications

The EIC is a major new project under construction at BNL in partnership with JLab. It relies upon a number of new SRF cavities at 197 MHz, 394 MHz, 591 MHz and 1773 MHz to pre-bunch, accelerate, cool and crab the stored beams. R&D is focusing on the 591 MHz elliptical cavity and 197 MHz crab cavity first as these are the most challenging. Preliminary designs of these cavities are presented along with an R&D status report. To avoid developing multiple different cryostats a modular approach is adopted using a high degree of commonality of parts and systems. This approach …

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Temperature, Rf Field, And Frequency Dependence Performance Evaluation Of Superconducting Niobium Half-Wave Coaxial Cavity, N. K. Raut, G. Ciovati, S. U. De Silva, J. R. Delayen, P. Dhakal, B. D. Khanal, J. K. Tiskumara Jan 2023

Temperature, Rf Field, And Frequency Dependence Performance Evaluation Of Superconducting Niobium Half-Wave Coaxial Cavity, N. K. Raut, G. Ciovati, S. U. De Silva, J. R. Delayen, P. Dhakal, B. D. Khanal, J. K. Tiskumara

Physics Faculty Publications

Recent advancement in superconducting radio frequency cavity processing techniques, with diffusion of impurities within the RF penetration depth, resulted in high quality factor with increase in quality factor with increasing accelerating gradient. The increase in quality factor is the result of a decrease in the surface resistance as a result of nonmagnetic impurities doping and change in electronic density of states. The fundamental understanding of the dependence of surface resistance on frequency and surface preparation is still an active area of research. Here, we present the result of RF measurements of the TEM modes in a coaxial half-wave niobium cavity …

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A Review Of Piezoelectric Footwear Energy Harvesters: Principles, Methods, And Applications, Bingqi Zhao, Feng Qian, Alexander Hatfield, Lei Zuo, Tian-Bing Xu Jan 2023

A Review Of Piezoelectric Footwear Energy Harvesters: Principles, Methods, And Applications, Bingqi Zhao, Feng Qian, Alexander Hatfield, Lei Zuo, Tian-Bing Xu

Mechanical & Aerospace Engineering Faculty Publications

Over the last couple of decades, numerous piezoelectric footwear energy harvesters (PFEHs) have been reported in the literature. This paper reviews the principles, methods, and applications of PFEH technologies. First, the popular piezoelectric materials used and their properties for PEEHs are summarized. Then, the force interaction with the ground and dynamic energy distribution on the footprint as well as accelerations are analyzed and summarized to provide the baseline, constraints, potential, and limitations for PFEH design. Furthermore, the energy flow from human walking to the usable energy by the PFEHs and the methods to improve the energy conversion efficiency are presented. …

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The Managerial Factors Influencing The Retention Of Firms' It Capability, With Some Global Implications, Jinho Kim, Kayoung Park, Timothy Komarek, Li Xu Jan 2023

The Managerial Factors Influencing The Retention Of Firms' It Capability, With Some Global Implications, Jinho Kim, Kayoung Park, Timothy Komarek, Li Xu

Mathematics & Statistics Faculty Publications

Researchers have explored firms’ IT capability and its effects on business performance, yet the factors influencing the long-term retention of this capability have not been fully investigated. Therefore, our study examines what managerial and financial factors influence the retention of firms’ IT capability by utilizing survival analysis. The results show that IT executives’ managerial power does not contribute to retaining the firms’ IT capability. However, the change of IT managers can introduce fresh insights and expertise to an organization, enabling firms to maintain their IT capability, and the degree of retaining IT competency in firms can vary based on industry-specific …

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More Properties Of Optimal Polynomial Approximants In Hardy Spaces, Raymond Cheng, Christopher Felder Jan 2023

More Properties Of Optimal Polynomial Approximants In Hardy Spaces, Raymond Cheng, Christopher Felder

Mathematics & Statistics Faculty Publications

We study optimal polynomial approximants (OPAs) in the classical Hardy spaces on the unit disk, Hp (1 < p < ∞). For fixed f ∈ Hp and n ∈ N, the OPA of degree n associated to f is the polynomial which minimizes the quantity ∥qf −1∥p over all complex polynomials q of degree less than or equal to n. We begin with some examples which illustrate, when p ≠ 2, how the Banach space geometry makes the above minimization problem interesting. We then weave through various results concerning limits and roots of these polynomials, including results which show that OPAs can be witnessed as solutions …

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