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Articles 57721 - 57750 of 294440

Full-Text Articles in Physical Sciences and Mathematics

First-Order Phase Transition And Fate Of False Vacuum Remnants, Kiyoharu Kawana, Philip Lu, Ke-Pan Xie Jun 2022

First-Order Phase Transition And Fate Of False Vacuum Remnants, Kiyoharu Kawana, Philip Lu, Ke-Pan Xie

Department of Physics and Astronomy: Faculty Publications

False vacuum remnants in first-order phase transitions in the early Universe can form compact objects which may constitute dark matter. Such remnants form because particles develop large mass gaps between the two phases and become trapped in the old phase. We focus on remnants generated in a class of models with trapped dark sector particles, trace their development, and determine their ultimate fate. Depending on model and phase transition parameters, the evolutionary endpoint of these remnants can be primordial black holes, Fermi-balls, Q-balls, or thermal balls, and they all have the potential to constitute some portion or the whole of …


Differentiating Fissure-Fed Lava Flow Types And Facies Using Radar And Lidar: An Example From The 2014–2015 Holuhraun Lava Flow-Field, Gavin Douglas Tolometti, Catherine D. Neish, Christopher W. Hamilton, Gordon R. Osinski, Antero Kukko, Joana R.C. Voigt Jun 2022

Differentiating Fissure-Fed Lava Flow Types And Facies Using Radar And Lidar: An Example From The 2014–2015 Holuhraun Lava Flow-Field, Gavin Douglas Tolometti, Catherine D. Neish, Christopher W. Hamilton, Gordon R. Osinski, Antero Kukko, Joana R.C. Voigt

Earth Sciences Publications

Distinguishing between lava types and facies using remote sensing data is important for interpreting the emplacement history of lava flow-fields on Earth and other planetary bodies. Lava facies typically include a mixture of lava types and record the collective emplacement history of material preserved at a particular location. We seek to determine if lava facies in the 2014–2015 Holuhraun lava flow-field are discernible using radar roughness analysis. Furthermore, we also seek to distinguish between lava types using high resolution Light Detection and Ranging (LiDAR) data. We extracted circular polarization ratios (CPR) from the Uninhabited Aerial Vehicle Synthetic Aperture Radar and …


Gull Plumages Are, And Are Not, What They Appear To Human Vision, Muir D. Eaton, Pilar Benites, Luke Campillo, Robert E. Wilson, Sarah A. Sonsthagen Jun 2022

Gull Plumages Are, And Are Not, What They Appear To Human Vision, Muir D. Eaton, Pilar Benites, Luke Campillo, Robert E. Wilson, Sarah A. Sonsthagen

School of Natural Resources: Faculty Publications

Clear correlations between human and bird visual assessments of color have been documented, and are often assumed, despite fundamental differences in human and avian visual physiology and morphology. Analyses of plumage colors with avian perceptual models have shown widespread hidden inter-sexual and inter-specific color variation among passerines perceived as monochromatic to humans, highlighting the uncertainty of human vision to predict potentially relevant variation in color. Herein, we use reflectance data from 13 Larus gull species as an exemplar data set to study concordance between human vision and avian visual modeling of feather colors near, or below, the human threshold for …


The Natural History And Ecology Of Melanism In Red Wolf And Coyote Populations Of The Southeastern United States – Evidence For Gloger’S Rule, Joseph W. Hinton, Kyla M. West, Daniel J. Sullivan, Jacqueline L. Frair, Michael J. Chamberlain Jun 2022

The Natural History And Ecology Of Melanism In Red Wolf And Coyote Populations Of The Southeastern United States – Evidence For Gloger’S Rule, Joseph W. Hinton, Kyla M. West, Daniel J. Sullivan, Jacqueline L. Frair, Michael J. Chamberlain

United States Environmental Protection Agency: Publications

Background: Gloger’s rule postulates that animals should be darker colored in warm and humid regions where dense vegetation and dark environments are common. Although rare in Canis populations, melanism in wolves is more common in North America than other regions globally and is believed to follow Gloger’s rule. In the temperate forests of the southeastern United States, historical records of red wolf (Canis rufus) and coyote (Canis latrans) populations document a consistent presence of melanism. Today, the melanistic phenotype is extinct in red wolves while occurring in coyotes and red wolf-coyote hybrids who occupy the …


Steel Module-To-Concrete Core Connection Methods In High Rise Modular Buildings: A Critical Review, Bishal Poudel, Seungtaek Lee, Jin Ouk Choi Jun 2022

Steel Module-To-Concrete Core Connection Methods In High Rise Modular Buildings: A Critical Review, Bishal Poudel, Seungtaek Lee, Jin Ouk Choi

Civil and Environmental Engineering and Construction Faculty Research

Modularization in a high-rise building is different from a small building, as it is exposed to more lateral forces like wind and earthquakes. The integrity, robustness, and overall stability of the modules and their performance is based on the joining techniques and strong structural systems. High lateral stiff construction structures like concrete shear walls and frames, braced steel frames, and steel moment frames are used for the stability of high-rise modular buildings. Similarly, high-rise stick-built buildings have concrete cores and perimeter frames for lateral load strength and stiffness. Methods for general steel-concrete connections are available in many works of literature. …


Butte Priority Soils Operable Unit (Bpsou) Draft Final Insufficiently Reclaimed Sites - Field Sampling Plan (Fsp) Bres No. 32 – Corra-2 Dumps., Mike Mcanulty Jun 2022

Butte Priority Soils Operable Unit (Bpsou) Draft Final Insufficiently Reclaimed Sites - Field Sampling Plan (Fsp) Bres No. 32 – Corra-2 Dumps., Mike Mcanulty

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Hybrid Modulated-Phase-Grating For Phase Contrast X-Ray For A Varying Fringe Period Clinical Interferometry System, Elizabeth Jeong Park Jun 2022

Hybrid Modulated-Phase-Grating For Phase Contrast X-Ray For A Varying Fringe Period Clinical Interferometry System, Elizabeth Jeong Park

LSU Master's Theses

Phase contrast x-rays are of use due to the range of imaging they can provide. Not only are they useful for attenuation they also can provide phase and small angle scatter X-ray (SAXS) information simultaneously which adds additional contrast and information to the original attention image. In prior work, a phase contrast system with Modulated Phase Grating was shown to eliminate the need for analyzer in standard Talbot Lau Xray Interferometers (TLXI). The system is clinically compatible in footprint due to its length being limited to


Exploring Structure-Function Relationship In Small-Molecular Catalysts Using Computational And Experimental Methodologies, Avik Bhattacharjee Jun 2022

Exploring Structure-Function Relationship In Small-Molecular Catalysts Using Computational And Experimental Methodologies, Avik Bhattacharjee

Dissertations and Theses

Molecular modeling is a useful tool in the field of catalyst design for various processes. The use of Density Functional Theory (DFT) is routine in almost every discipline of chemistry. This allows for a deeper understanding of a molecular system even in situations where implementation of an experimental technique is unfeasible. However, without the right choice of theory and insufficient description, the model becomes susceptible to produce ambiguous results. This often leads to poor correlation with experimental findings hence an incomplete understanding of the system under study. Hence, to acquire a thorough knowledge of the intricacies involved in a system, …


Narrowband Searches For Continuous And Long-Duration Transient Gravitational Waves From Known Pulsars In The Ligo-Virgo Third Observing Run, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Volker Quetschke, Wenhui Wang Jun 2022

Narrowband Searches For Continuous And Long-Duration Transient Gravitational Waves From Known Pulsars In The Ligo-Virgo Third Observing Run, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Volker Quetschke, Wenhui Wang

Physics & Astronomy Faculty Publications

Isolated neutron stars that are asymmetric with respect to their spin axis are possible sources of detectable continuous gravitational waves. This paper presents a fully coherent search for such signals from eighteen pulsars in data from LIGO and Virgo's third observing run (O3). For known pulsars, efficient and sensitive matched-filter searches can be carried out if one assumes the gravitational radiation is phase-locked to the electromagnetic emission. In the search presented here, we relax this assumption and allow both the frequency and the time derivative of the frequency of the gravitational waves to vary in a small range around those …


Emplacement Of The Dadeville Complex Of The Southernmost Inner Piedmont Within The 7.5 Min. Cusseta Quadrangle, Chambers County, Alabama: Channel Flow, Klippe Kinematics, Or Orogen Parallel Translation, Timothy Black Jun 2022

Emplacement Of The Dadeville Complex Of The Southernmost Inner Piedmont Within The 7.5 Min. Cusseta Quadrangle, Chambers County, Alabama: Channel Flow, Klippe Kinematics, Or Orogen Parallel Translation, Timothy Black

Master's Theses

The Appalachian Mountains have a complex geologic history spanning three orogenic periods, the Taconic, the Acadian/Neoacadian, and Alleghanian orogenies. The Inner Piedmont of the Appalachian Mountains within Alabama contains two distinct lithologic complexes, the Dadeville Complex, and the Opelika Complex separated by the Stonewall Line. These complexes were formed during an arc-back arc fringing system during the Taconic orogeny and emplaced and recorded peak metamorphism during the Acadian orogeny.

The Dadeville Complex is an allochthonous arc terrain built on extended Laurentian crust. The mode of transportation and accretion after formation is not well understood, which has implications for the role …


Examining Metal Contents In Primary And Secondhand Aerosols Released By Electronic Cigarettes, Kashala Fabrice Kapiamba, Weixing Hao, Stephen Adom, Wenyan Liu, Yue-Wern Huang, Yang Wang Jun 2022

Examining Metal Contents In Primary And Secondhand Aerosols Released By Electronic Cigarettes, Kashala Fabrice Kapiamba, Weixing Hao, Stephen Adom, Wenyan Liu, Yue-Wern Huang, Yang Wang

Chemistry Faculty Research & Creative Works

The usage of electronic cigarettes (ECs) has surged since their invention two decades ago. However, to date, the health effects of EC aerosol exposure are still not well understood because of insufficient data on the chemical composition of EC aerosols and the corresponding evidence of health risks upon exposure. Herein, we quantified the metals in primary and secondhand aerosols generated by three brands of ECs. By combining aerosol filter sampling and inductively coupled plasma mass spectrometry (ICP-MS), we assessed the mass of metals as a function of EC flavoring, nicotine concentration, device power, puff duration, and aging of the devices. …


Constructing Green Gdp Evaluation System By Using Think Tank Double Helix Methodology, Hongbing Wang, Yijun Liu, Dawei Song Jun 2022

Constructing Green Gdp Evaluation System By Using Think Tank Double Helix Methodology, Hongbing Wang, Yijun Liu, Dawei Song

Bulletin of Chinese Academy of Sciences (Chinese Version)

In the new development stage, taking green GDP as the starting point for the development of green economy, low-carbon economy, and circular economy and an important indicator to measure high-quality development, sustainable development, and modernization is an effective way to ensure the construction of "beautiful China", basically realize socialist modernization and achieve the goal of carbon neutrality. This study uses the double helix theory of think tank to innovate a new paradigm of green GDP research and broaden the research path of GDP evaluation system. In terms of epistemology, the think tank double helix methodology provides a new systematic perspective …


Marine Ranching Version 3.0: History, Status And Prospects, Hongsheng Yang, Dewen Ding Jun 2022

Marine Ranching Version 3.0: History, Status And Prospects, Hongsheng Yang, Dewen Ding

Bulletin of Chinese Academy of Sciences (Chinese Version)

Since the 1930s, the construction of marine ranching has successively experienced the version 1.0 (traditional marine ranching) of farming-ranching and engineering, and the version 2.0 (marine ecological ranching) of ecologization and informatization, and now it is about to enter the version 3.0 (global aquatic ecological ranching) of digitalization and systematization, which covers seawater and fresh water. Marine ranching version 3.0 must adhere to the modern aquatic ecological ranching development concept of "ecology, precision, intelligence, integration", characterized by synchronous protection and utilization, expansion of scene and space, breakthrough in core technology, and innovation in development patterns. After establishing the whole industrial …


Determining Depth Of Closure Based On Time-Series Beach Profiles And Empirical Formulas: A Case Study Along The Florida Coast, Elizabeth Royer Jun 2022

Determining Depth Of Closure Based On Time-Series Beach Profiles And Empirical Formulas: A Case Study Along The Florida Coast, Elizabeth Royer

USF Tampa Graduate Theses and Dissertations

Depth of closure (DOC) is defined as the most landward depth seaward of which there is no significant change in bed elevation and no significant net sediment exchange between the nearshore and the offshore over a certain period of time, such as 5 to 20 years. DOC is an essential parameter used in beach and shore protection, sediment management, and many other aspects of coastal studies. Taking advantage of advancements in wave hindcast and bathymetry measurement in the past 20 years (2000-2019), this study determined the DOC at 12 locations along the Florida coast, including three from the northwest Gulf …


Assessment Of Sentinel-2 And Landsat-8 Oli For Small-Scale Inland Water Quality Modeling And Monitoring Based On Handheld Hyperspectral Ground Truthing, Qasem Abdel, Mohammed N. Assaf, Abdulla Al-Rawabdeh, Sameer Arabasi, Nathir A. Rawashdeh Jun 2022

Assessment Of Sentinel-2 And Landsat-8 Oli For Small-Scale Inland Water Quality Modeling And Monitoring Based On Handheld Hyperspectral Ground Truthing, Qasem Abdel, Mohammed N. Assaf, Abdulla Al-Rawabdeh, Sameer Arabasi, Nathir A. Rawashdeh

Michigan Tech Publications, Part 1

This study investigates the best available methods for remote monitoring inland small-scale waterbodies, using remote sensing data from both Landsat-8 and Sentinel-2 satellites, utilizing a handheld hyperspectral device for ground truthing. Monitoring was conducted to evaluate water quality indicators: chlorophyll-a (Chl-a), colored dissolved organic matter (CDOM), and turbidity. Ground truthing was performed to select the most suitable atmospheric correction technique (ACT). Several ACT have been tested: dark spectrum fitting (DSF), dark object subtraction (DOS), atmospheric and topographic correction (ATCOR), and exponential extrapolation (EXP). Classical sampling was conducted first; then, the resulting concentrations were compared to those obtained using remote sensing …


Butte Priority Soils Operable Unit (Bpsou) Draft Final Insufficiently Reclaimed Sites - Field Sampling Plan (Fsp) Bres No. 158 - Waste Rock Dump., Mike Mcanulty Jun 2022

Butte Priority Soils Operable Unit (Bpsou) Draft Final Insufficiently Reclaimed Sites - Field Sampling Plan (Fsp) Bres No. 158 - Waste Rock Dump., Mike Mcanulty

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Microbiome Assembly In Thawing Permafrost And Its Feedbacks To Climate, Jessica G. Ernakovich, Robyn A. Barbato, Virginia I. Ritch, Christina Schadel, Rebecca E. Hewitt, Stacey J. Doherty, Emily D. Whalen, Benjamin Abbott, Jiri Barta, Christina Biasi, Chris L. Chabot, Jenni Hultman, Christian Knoblauch, Maggie C. Y. Lau Vetter, Mary-Cathrine Leewis, Susanne Liebner, Rachel Mackelprang, Tullis C. Onstott, Andreas Richter, Ursel M. E. Schutte, Henri M. P. Siljanen, Neslihan Tas, Ina Timling, Tatiana A. Vishnivetskaya, Mark P. Waldrop, Matthias Winkel Jun 2022

Microbiome Assembly In Thawing Permafrost And Its Feedbacks To Climate, Jessica G. Ernakovich, Robyn A. Barbato, Virginia I. Ritch, Christina Schadel, Rebecca E. Hewitt, Stacey J. Doherty, Emily D. Whalen, Benjamin Abbott, Jiri Barta, Christina Biasi, Chris L. Chabot, Jenni Hultman, Christian Knoblauch, Maggie C. Y. Lau Vetter, Mary-Cathrine Leewis, Susanne Liebner, Rachel Mackelprang, Tullis C. Onstott, Andreas Richter, Ursel M. E. Schutte, Henri M. P. Siljanen, Neslihan Tas, Ina Timling, Tatiana A. Vishnivetskaya, Mark P. Waldrop, Matthias Winkel

Faculty Publications

The physical and chemical changes that accompany permafrost thaw directly influence the microbial communities that mediate the decomposition of formerly frozen organic matter, leading to uncertainty in permafrost–climate feedbacks. Although changes to microbial metabolism and community structure are documented following thaw, the generality of post-thaw assembly patterns across permafrost soils of the world remains uncertain, limiting our ability to predict biogeochemistry and microbial community responses to climate change. Based on our review of the Arctic microbiome, permafrost microbiology, and community ecology, we propose that Assembly Theory provides a framework to better understand thaw-mediated microbiome changes and the implications for community …


Foraging Habitat Selection Of Shrubland Bird Community In Tropical Dry Forest, Anant Deshwal, Steven L. Stephenson, Pooja Panwar, Brett A. Degregorio, Ragupathy Kannan, John D. Willson Jun 2022

Foraging Habitat Selection Of Shrubland Bird Community In Tropical Dry Forest, Anant Deshwal, Steven L. Stephenson, Pooja Panwar, Brett A. Degregorio, Ragupathy Kannan, John D. Willson

United States Geological Survey: Staff Publications

Habitat loss due to increasing anthropogenic disturbance is the major driver for bird population declines across the globe. Within the Eastern Ghats of India, shrubland bird communities are threatened by shrinking of suitable habitats due to increased anthropogenic disturbance and climate change. The development of an effective habitat management strategy is hampered by the absence of data for this bird community. To address this knowledge gap, we examined foraging sites for 14 shrubland bird species, including three declining species, in three study areas representing the shrubland type of forest community in the Eastern Ghats. We recorded microhabitat features within an …


4d Gas Geological Research On Coal Seam With Gas Hazard Potential In Mining Panel, Hongqing Cui, Xin He, Zehua Wang Jun 2022

4d Gas Geological Research On Coal Seam With Gas Hazard Potential In Mining Panel, Hongqing Cui, Xin He, Zehua Wang

Journal of Sustainable Mining

According to regulations of the mining industry in China, it is necessary to carry out gas hazard prevention projects in advance when mining coal seams with gas hazard potential, and gas geological research should be taken as the basic work for optimal design and effective construction of gas hazard prevention projects. Research on coal seam with gas hazard potential have shown that anomalous geological area could be the gas hazard potential area as well, where superimposed tectonic and mining stress field usually results in tectonically disturbed coal and pressured gas. A 4D gas geological research method is used to find …


Dynamic Prototype Convolution Network For Few-Shot Semantic Segmentation, Jie Liu, Yanqi Bao, Guo-Sen Xie, Huan Xiong, Jan-Jakob Sonke, Efstratios Gavves Jun 2022

Dynamic Prototype Convolution Network For Few-Shot Semantic Segmentation, Jie Liu, Yanqi Bao, Guo-Sen Xie, Huan Xiong, Jan-Jakob Sonke, Efstratios Gavves

Machine Learning Faculty Publications

The key challenge for few-shot semantic segmentation (FSS) is how to tailor a desirable interaction among sup-port and query features and/or their prototypes, under the episodic training scenario. Most existing FSS methods im-plement such support/query interactions by solely leveraging plain operations - e.g., cosine similarity and feature concatenation - for segmenting the query objects. How-ever, these interaction approaches usually cannot well capture the intrinsic object details in the query images that are widely encountered in FSS, e.g., if the query object to be segmented has holes and slots, inaccurate segmentation al-most always happens. To this end, we propose a dynamic …


Identifying The Geographic Origins Of Invasive Megathyrsus Maximus In The United States Using Molecular Data, John F. Gaskin, John A. Goolsby, Marie Claude Bon, Massimo Cristofaro, Paul André Calatayud Jun 2022

Identifying The Geographic Origins Of Invasive Megathyrsus Maximus In The United States Using Molecular Data, John F. Gaskin, John A. Goolsby, Marie Claude Bon, Massimo Cristofaro, Paul André Calatayud

All Peer-Reviewed Publications

Megathyrsus maximus is nonnative in the neotropics, with a tall form that is commonly used as a forage grass and a smaller-statured form that is considered invasive in south Texas, USA. Biological control researchers are challenged to find an agent that will attack the short form, but not the desirable tall form in other parts of the neotropics. We conducted molecular analyses on 155 Megathyrsus maximus samples from its native range in Africa and compared them with U.S. short-form samples to help determine the geographic origins of its invasion. We found eight distinct genotypes in 34 short-form samples from Texas …


Accident Simulation Study For Nuclear Power Plants Impacting Louisiana, Michael D. Mcmahon Jun 2022

Accident Simulation Study For Nuclear Power Plants Impacting Louisiana, Michael D. Mcmahon

LSU Master's Theses

INTRODUCTION: Louisiana has aligned its radiological emergency program with the 2017 Environmental Protection Agency Protective Action Guides Manual, but has added a child thyroid dose evacuation threshold in lieu of distributing Potassium Iodide to the public. The nuclear power plants will continue to align with the 1992 manual for the foreseeable future, so that under some accident scenarios the state recommendations will differ from those of the utility.

OBJECTIVE: The objective of this study is to predict what accident and weather conditions will lead to a differing set of recommendations.

METHODS: More than 1000 simulations were performed of low-filtration nuclear …


Ocean-Atmosphere Variability In The Northwest Atlantic Ocean During Active Marine Heatwave Years, Lydia D. Sims, Bulusu Subrahmanyam, Corinne B. Trott Jun 2022

Ocean-Atmosphere Variability In The Northwest Atlantic Ocean During Active Marine Heatwave Years, Lydia D. Sims, Bulusu Subrahmanyam, Corinne B. Trott

Faculty Publications

The Northwest (NW) Atlantic has experienced extreme ecological impacts from Marine Heatwaves (MHWs) within the past decade. This paper focuses on four MHW active years (2012, 2016, 2017, and 2020) and the relationship between Sea Surface Temperature anomalies (SSTA), Sea Surface Salinity anomalies (SSSA), North Atlantic Oscillation (NAO), Geopotential Height anomalies (ZA), and anomalous Jet Stream positions (JSPA). Multichannel singular spectrum analysis (MSSA) reveals the strongest temporal covariances between SSSA and SSTA, and JSPA and SSTA for all years, particularly for 2020 (SSSA–SSTA: 50%, JSPA–SSTA: 51%) indicating that this active MHW year was more atmospherically driven, followed by 2012, which …


Actuator Cyberattack Handling Using Lyapunov-Based Economic Model Predictive Control, Keshav Kasturi Rangan, Henrique Oyama, Helen Durand Jun 2022

Actuator Cyberattack Handling Using Lyapunov-Based Economic Model Predictive Control, Keshav Kasturi Rangan, Henrique Oyama, Helen Durand

Chemical Engineering and Materials Science Faculty Research Publications

Cybersecurity has gained increasing interest as a consequence of the potential impacts of cyberattacks on profits and safety. While attacks can affect various components of a plant, prior work from our group has focused on the impact of cyberattacks on control components such as process sensors and actuators and the development of detection strategies for cybersecurity derived from control theory. In this work, we provide greater focus on actuator attacks; specifically, we extend a detection and control strategy previously applied for sensor attacks and based on an optimization-based control technique called Lyapunov-based economic model predictive control (LEMPC) to detect attacks …


Test Methods For Image-Based Information In Next-Generation Manufacturing, Henrique Oyama, Dominic Messina, Renee O'Neill, Samantha Cherney, Minhazur Rahman, Keshav Kasturi Rangan, Govanni Gjonaj, Helen Durand Jun 2022

Test Methods For Image-Based Information In Next-Generation Manufacturing, Henrique Oyama, Dominic Messina, Renee O'Neill, Samantha Cherney, Minhazur Rahman, Keshav Kasturi Rangan, Govanni Gjonaj, Helen Durand

Chemical Engineering and Materials Science Faculty Research Publications

Typical control designs in the process systems engineering literature have assumed that the primary sensing methodologies are traditional instruments such as thermocouples. Dig- italization is changing the landscape for manufacturing, and data-based sensing modalities (e.g., image-based sensing) are becoming of greater interest for plant control. These considerations require novel test/evaluation solutions. For example, process systems engineering researchers may wish to test image-based sensors in simulation. In this work, we provide preliminary thoughts on how image-based technologies might be evaluated via simulation for process systems.


Quantum Computing And Resilient Design Perspectives For Cybersecurity Of Feedback Systems, Keshav Kasturi Rangan, Jihan Abou Halloun, Henrique Oyama, Samantha Cherney, Ilham Azali Assoumani, Nazir Jairazbhoy, Helen Durand, Simon Ka Ng Jun 2022

Quantum Computing And Resilient Design Perspectives For Cybersecurity Of Feedback Systems, Keshav Kasturi Rangan, Jihan Abou Halloun, Henrique Oyama, Samantha Cherney, Ilham Azali Assoumani, Nazir Jairazbhoy, Helen Durand, Simon Ka Ng

Chemical Engineering and Materials Science Faculty Research Publications

Cybersecurity of control systems is an important issue in next-generation manufac- turing that can impact both operational objectives (safety and performance) as well as process designs (via hazard analysis). Cyberattacks differ from faults in that they can be coordinated efforts to exploit system vulnerabilities to create otherwise unlikely hazard scenarios. Because coordination and targeted process manipulation can be characteristics of attacks, some of the tactics previously analyzed in our group from a control system cybersecurity perspective have incorporated randomness to attempt to thwart attacks. The underlying assumption for the generation of this randomness has been that it can be achieved …


Challenges And Opportunities For Next-Generation Manufacturing In Space, Kip Nieman, A. F. Leonard, Katie Tyrell, Dominic Messina, Rebecca Lopez, Helen Durand Jun 2022

Challenges And Opportunities For Next-Generation Manufacturing In Space, Kip Nieman, A. F. Leonard, Katie Tyrell, Dominic Messina, Rebecca Lopez, Helen Durand

Chemical Engineering and Materials Science Faculty Research Publications

With commercial space travel now a reality, the idea that people might spend time on other planets in the future seems to have greater potential. To make this possible, however, there needs to be flexible means for manufacturing in space to enable tooling or resources to be created when needed to handle unexpected situations. Next-generation manufacturing paradigms offer significant potential for the kind of flexibility that might be needed; however, they can result in increases in computation time compared to traditional control methods that could make many of the computing resources already available on earth attractive for use. Furthermore, resilience …


A Generalization Of Combinatorial Identities For Stable Discrete Series Constants, Richard Ehrenborg, Sophie Moreland, Margaret Readdy Jun 2022

A Generalization Of Combinatorial Identities For Stable Discrete Series Constants, Richard Ehrenborg, Sophie Moreland, Margaret Readdy

Mathematics Faculty Publications

This article is concerned with the constants that appear in Harish-Chandra’s character formula for stable discrete series of real reductive groups, although it does not require any knowledge about real reductive groups or discrete series. In Harish-Chandra’s work the only information we have about these constants is that they are uniquely determined by an inductive property. Later, Goresky–Kottwitz–MacPherson (1997) and Herb (2000) gave different formulas for these constants. In this article, we generalize these formulas to the case of arbitrary finite Coxeter groups (in this setting, discrete series no longer make sense), and give a direct proof that the two …


Evaluating The Biogeochemical Effects Of Enhanced Rock Weathering At Lawrence University, Katie Mahorney Jun 2022

Evaluating The Biogeochemical Effects Of Enhanced Rock Weathering At Lawrence University, Katie Mahorney

Lawrence University Honors Projects

On geologic timescales, the weathering of silicate rocks is among the most powerful negative feedbacks controlling atmospheric CO2. However, this process is too slow to meaningfully impact our current climate crisis. Enhanced Rock Weathering (ERW) is one of the most promising carbon capture strategies to remove anthropogenic carbon from the atmosphere. Models suggest that by crushing silicate rocks such as basalt to increase surface area, the process of rock weathering can be accelerated to sequester enough carbon to be significant on human timescales. At Lawrence University, ERW is being investigated to (1) field test the efficacy of the …


Patterned And Infiltrated Vertically Aligned Carbon Nanotube Ultra-Black Materials, Kevin Laughlin Jun 2022

Patterned And Infiltrated Vertically Aligned Carbon Nanotube Ultra-Black Materials, Kevin Laughlin

Theses and Dissertations

Ultra-black materials reflect less than 1% of incident light, and are used in a wide variety of applications from low signal detector systems, to jewelry. The darkest ultra-black materials are made with vertically aligned carbon nanotubes (VACNTs). One downside to these VACNT based ultra-black material, is they are extremely fragile, and the types of surfaces they can be grown on is limited. Here I created a strengthened ultra-black material that can withstand light handling and drying from water exposure, and can be transferred to other substrates while remaining ultra-black. I also present theoretical models with supporting data on how to …