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Articles 15931 - 15960 of 302419

Full-Text Articles in Physical Sciences and Mathematics

Dipole Cooperativity And Polarization Frustration Determine The Secondary Structure Distribution Of Short Alanine Peptides In Water, Ying Yuan, Feng Wang Apr 2023

Dipole Cooperativity And Polarization Frustration Determine The Secondary Structure Distribution Of Short Alanine Peptides In Water, Ying Yuan, Feng Wang

Chemistry & Biochemistry Faculty Publications and Presentations

The physical driving forces for secondary structure preferences of hydrated alanine peptide are investigated with B3LYP-D3(BJ) and the adaptive force matching (AFM) method. The AFM fit to the DFT surface, ALA2022, provides excellent agreement with the nuclear magnetic resonance scalar coupling constants from experiments. In turn, the model is used to gain insight into the physical driving forces behind secondary structure preferences of hydrated peptides. DFT calculations with and without the Conductor-like Screening Model (COSMO) show that the α helix is stabilized by solvent polarization due to dipole cooperativity. The two adjacent amide groups in β strand form a near-planar …

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Simulating A Flexible Water Model As Rigid: Best Practices And Lessons Learned, Raymond Weldon, Feng Wang Apr 2023

Simulating A Flexible Water Model As Rigid: Best Practices And Lessons Learned, Raymond Weldon, Feng Wang

Chemistry & Biochemistry Faculty Publications and Presentations

Two ways to create rigid versions of flexible models are explored. The rigid model can assume the Model’s Geometry (MG) as if the molecule is not interacting with any other molecules or the ensemble averaged geometry (EG) under a particular thermodynamic condition. Although the MG model is more straightforward to create, it leads to relatively poor performance. The EG model behaves similarly to the corresponding flexible model (the FL model) and, in some cases, agrees even better with experiments. While the difference between the EG and the FL models is mostly a result of flexibility, the MG and EG models …

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Developing Resilient Cyber-Physical Systems: A Review Of State-Of-The-Art Malware Detection Approaches, Gaps, And Future Directions, M. Imran Malik, Ahmed Ibrahim, Peter Hannay, Leslie F. Sikos Apr 2023

Developing Resilient Cyber-Physical Systems: A Review Of State-Of-The-Art Malware Detection Approaches, Gaps, And Future Directions, M. Imran Malik, Ahmed Ibrahim, Peter Hannay, Leslie F. Sikos

Research outputs 2022 to 2026

Cyber-physical systems (CPSes) are rapidly evolving in critical infrastructure (CI) domains such as smart grid, healthcare, the military, and telecommunication. These systems are continually threatened by malicious software (malware) attacks by adversaries due to their improvised tactics and attack methods. A minor configuration change in a CPS through malware has devastating effects, which the world has seen in Stuxnet, BlackEnergy, Industroyer, and Triton. This paper is a comprehensive review of malware analysis practices currently being used and their limitations and efficacy in securing CPSes. Using well-known real-world incidents, we have covered the significant impacts when a CPS is compromised. In …

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Influence Of Clay Content On Co2-Rock Interaction And Mineral-Trapping Capacity Of Sandstone Reservoirs, Emad A. Al-Khdheeawi, Doaa Saleh Mahdi, Yujie Yuan, Stefan Iglauer Apr 2023

Influence Of Clay Content On Co2-Rock Interaction And Mineral-Trapping Capacity Of Sandstone Reservoirs, Emad A. Al-Khdheeawi, Doaa Saleh Mahdi, Yujie Yuan, Stefan Iglauer

Research outputs 2022 to 2026

The injection of carbon dioxide (CO2) is an essential technology for maximizing the potential of hydrocarbon reservoirs while reducing the impact of greenhouse gases. However, because of the complexity of this injection, there will be many different chemical reactions between the formation fluids and the rock minerals. This is related to the clay content of sandstone reservoirs, which are key storage targets. Clay content and clay types in sandstone can vary substantially, and the influence of these factors on reservoir-scale CO2-water-sandstone interactions has not been managed appropriately. Consequently, by simulating the process of CO2 injection in two different clay-content sandstones …

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Talking To The Earth: A Digital Documentation Of Biodiversity In The Sherpa Language, Dvij Sharma Apr 2023

Talking To The Earth: A Digital Documentation Of Biodiversity In The Sherpa Language, Dvij Sharma

Independent Study Project (ISP) Collection

Identified as a pressing matter by organizations as prominent as the UN, the conservation of minority and indigenous languages “is essential for ensuring the continuation and transmission of culture, customs, and history, but it is also important to address biodiversity loss and climate change.” This project focuses on one of the latter issues, biodiversity loss, as it relates to Sherpa, a minority language spoken primarily in Eastern Nepal. In an effort to help preserve the native vocabulary and descriptions of basic plants and animals found in Sherpa-speaking regions, primarily interview-based fieldwork was conducted in the lower Solu regions of Lumsa, …

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Ecological Living In Nepali Food Systems: A Synthesis Of Circular Nutrient And Knowledge Flows In The Kathmandu Valley, Kaitlyn Feely Apr 2023

Ecological Living In Nepali Food Systems: A Synthesis Of Circular Nutrient And Knowledge Flows In The Kathmandu Valley, Kaitlyn Feely

Independent Study Project (ISP) Collection

Researching food-systems in Nepal can feel like drinking from a fire hydrant. Sixty-six percent of the population is directly involved in agriculture and a diverse set of ecocultural understandings influence the practice across the country’s landscapes, ranging from the Himalayas to urban centers to southern plains. In the Kathmandu Valley and peripheral hills where I conducted my research, seemingly any spare land was under cultivation, enabled by fertile ground, optimal climate, and market potential. But despite the prevalence of farming in daily life throughout the country, Nepal’s food system is not domestically self-sufficient. A complex web of imports and exports …

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Abcds Of Triggerfish In Pemba And Misali Island: Abundance, Biodiversity, Behaviour, Cultural Significance And Distribution, Hannah Ng Shueh Yi Apr 2023

Abcds Of Triggerfish In Pemba And Misali Island: Abundance, Biodiversity, Behaviour, Cultural Significance And Distribution, Hannah Ng Shueh Yi

Independent Study Project (ISP) Collection

This study takes a socioecological approach to understanding triggerfish (Balistidae) in Pemba Island, using Misali Island reefs as a sample ecological site. Two reef sites on Misali Island and three of four districts in Pemba were observed during the study. The abundance of Balistipus undulatus at one of two study sites is close to the maximum carrying capacity of the reef. Overall observed biodiversity was low. Behavioural trends point to distinct species specific defence strategies and species aggression taking different forms. Triggerfishes cultural significance was primarily as a food fish, though it is not highly sought after. With polarised responses …

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Wishing For Water While Fleeing Their Farms: A Study Of Water Scarcity And Internal Migration In Tunisia, Tyler Rak Apr 2023

Wishing For Water While Fleeing Their Farms: A Study Of Water Scarcity And Internal Migration In Tunisia, Tyler Rak

Independent Study Project (ISP) Collection

How does water scarcity and limited water access impact internal migration? I argue that water scarcity and limited access to water is likely to increase internal migration in Tunisia. The mechanism through which I will investigate this relationship is in the agricultural sector. In this research, I found that water scarcity does exist in Tunisia and that scarcity impacts the economy, employment, and perceptions of rural areas in Tunisia. This, in turn, likely contributes to internal migration, although my research could not conclude whether water scarcity acts a causative factor to internal migration. This topic has become more prevalent than …

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Consumo Verde ¿Para Quién?: Las Tierras, Cosmovisiones, Y Personas Escondidas Detrás De La Fiebre Del Oro Blanco / Green Consumption, For Who?: The Lands, World Views, And People Hidden Behind The White Gold Rush., Gabriel Gómez Apr 2023

Consumo Verde ¿Para Quién?: Las Tierras, Cosmovisiones, Y Personas Escondidas Detrás De La Fiebre Del Oro Blanco / Green Consumption, For Who?: The Lands, World Views, And People Hidden Behind The White Gold Rush., Gabriel Gómez

Independent Study Project (ISP) Collection

La “Transición energética” a consumo verde ha sido reconocida globalmente como el camino necesario para evitar lo peor de la crisis climática, pero es una solución que depende en un aumento del litio. La manera más usada para extraer el litio genera impactos destructivos en los ambientes que contienen el recurso, y en Sudamérica, donde los habitantes son mayormente indígena. Usando las comunidades de Salinas Grandes y Laguna de Guayatayoc en Jujuy, Argentina como un caso práctico, este proyecto propone analizar cómo el discurso hegemónico del consumo verde invisibiliza a gente indígena, y cómo estas comunidades resisten entendimientos occidentales y …

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A Transition Point: The Role Of The Global Power Shift In Facilitating Saudi Internal Reforms, Aidan Aguilar Apr 2023

A Transition Point: The Role Of The Global Power Shift In Facilitating Saudi Internal Reforms, Aidan Aguilar

Independent Study Project (ISP) Collection

The increasing political and economic influence of China represents a pivotal point within international relations. This paper aims to explore the implications of this global power shift on Saudi Arabia’s attempted economic reforms. The Kingdom’s reliance on oil has created an unsustainable economic model, and this model is intrinsically linked to Saudi Arabia’s relationship with the United States. Its growing relationship with China could create change. As such, this paper analyzes the intersection of economics and security in relation to the Saudi Vision 2030. I argue that, not only does China serve as an important source of the investment necessary …

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Anuran Species Diversity And Abundance Between Three Locations In El Valle De Antón, Coclé, Panamá, Xena Gehring Apr 2023

Anuran Species Diversity And Abundance Between Three Locations In El Valle De Antón, Coclé, Panamá, Xena Gehring

Independent Study Project (ISP) Collection

Panama is an incredibly biodiverse country that houses 230 species of amphibians including 188 species of frogs, 35 of which are endemic to Panama. Commonly found in terrestrial and aquatic habitats, frogs play a very important role in the regulation of insect populations and serve as a valuable food resource to other predators. The greatest threat to amphibian species at this time is Chytridiomycosis, a fungal pathogen that infects the skin and often results in death. Many species of amphibians have already gone completely extinct or are extinct in the wild due to the proliferation of this disease. The skin …

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Understanding Invasive Predation: Detections Of Feral Cats (Felis Catus) On Kangaroo Island’S Western River Refuge, Leah Boget Apr 2023

Understanding Invasive Predation: Detections Of Feral Cats (Felis Catus) On Kangaroo Island’S Western River Refuge, Leah Boget

Independent Study Project (ISP) Collection

Feral cats (Felis catus) are a priority-level threat for small to medium-sized native vertebrates across Australia and especially so in insular environments like that of Kangaroo Island, South Australia. The island is home to several endangered and geographically restricted species, including the Kangaroo Island Dunnart (Sminthopsis aitkeni), an endangered marsupial endemic to Kangaroo Island. When bushfires spread across the island and burned x percent of native vegetation in late 2019 to early 2020, these populations were critically impacted and post-fire feral cat predation on the island risked their extinctions, motivating the creation of a refuge with …

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Impact Of Wildlife Provisioning On Species Diversity, Relative Frequency, And Richness In New South Wales, Alanah Cohen-Tigör Apr 2023

Impact Of Wildlife Provisioning On Species Diversity, Relative Frequency, And Richness In New South Wales, Alanah Cohen-Tigör

Independent Study Project (ISP) Collection

Wildlife provisioning and camera trapping are two recently evolving methods of conservation and wildlife management, aimed at protecting animals in the face of ever worsening climate change. Habitats are being destroyed by climate disruption, decreasing species diversity and abundance worldwide. It is imperative that methods of protecting species are developed to slow or reverse this era of extinction. By providing supplementary food and water to ecological communities, the hope is that species will have improved survivorship and reproduction, making them more resilient and resistant to population decline. Camera trapping is product of modern technology, allowing researchers to monitor species without …

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Dairy & Development: An Investigation Into The Economic And Sociopolitical Dynamics Of Yak Cheesemaking In Nepal, Audrey Peiker Apr 2023

Dairy & Development: An Investigation Into The Economic And Sociopolitical Dynamics Of Yak Cheesemaking In Nepal, Audrey Peiker

Independent Study Project (ISP) Collection

Cheesemaking in Nepal is full of love, passion, and creativity. What began as a Swiss development project in the 1950s has now grown into a full-fledged industry, providing jobs, creative outlets, and cultural expression for many. Nepal’s Dairy Development Corporation owns several factories throughout the country, setting the tone for the industry by establishing the standard price for milk and process for cheesemaking. From there, privately held factories innovate and compete, bringing new products to the market and increasing wages, but also struggle with consistency and reliability. Now, Nepal’s cheesemaking market is at a turning point—much of the herding population …

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Status Of Pangolins: A Case Study On "The Most Trafficked Mammal In The World" In Central-South Of Nepal, Tsogyal Wangmo Lama Apr 2023

Status Of Pangolins: A Case Study On "The Most Trafficked Mammal In The World" In Central-South Of Nepal, Tsogyal Wangmo Lama

Independent Study Project (ISP) Collection

Pangolins are subject to constant trafficking in Asia and increasingly in Africa for their meat and scales. Very little research is done on this species due to its nocturnal, burrowing, and elusive nature. The larger the size of an animal is, the better it is known to the people and vice versa. Hence all these eight species of pangolins despite being under the International Union for Conservation of Nature (IUCN) red list with the four Asian species declared endangered or critically endangered, are still illegally abused and used for ulterior motives due to a lack of awareness among the general …

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Biodiversidad De Plantas En La Reserva Natural Urbana Punta Popper En Río Grande: Una Propuesta Para Senderos Para La Gestión De La Conservación Y Métodos De Campo Replicables En Un Etorno Educativo, Lili Weir Apr 2023

Biodiversidad De Plantas En La Reserva Natural Urbana Punta Popper En Río Grande: Una Propuesta Para Senderos Para La Gestión De La Conservación Y Métodos De Campo Replicables En Un Etorno Educativo, Lili Weir

Independent Study Project (ISP) Collection

The Patagonian Steppe is an ecoregion that is rich in plant biodiversity (both native and introduced), and the Urban Nature Reserves like Punta Popper in Río Grande provide an opportunity to preserve these sensitive species and educate the public, especially students, about the value of this trophic level. However, many beautiful species are being affected by human activities in the Reserve: such as the mismanagement of the trail systems which has led to erosion of the sand dunes, and the pressures of rapid urban expansion contributing to trash pollution. It is essential that stakeholder communities have access to information and …

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Inside The Wave: How “The 100 Foot Wave” Changed The Lives Of The Local Community In Nazaré, Emilie Cohen Apr 2023

Inside The Wave: How “The 100 Foot Wave” Changed The Lives Of The Local Community In Nazaré, Emilie Cohen

Independent Study Project (ISP) Collection

Surfing and surfing tourism are a critical part of Portugal’s economy and culture. Nazaré is a town that embodies a transition from a traditional fishing village to one that lives and breathes surf. Such a quick change in the leading industry of a town raises concerns about the impacts it has on the community. Therefore, the project focuses on the economic, social and cultural, and environmental impacts of tourism intensification on the local community in Nazaré through the perspective of the local people who are directly impacted and witness these changes. Other stakeholders are included, such as the Garrett McNamara …

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A Multi-Factorial Analysis Of The Sustainability Of Non-Governmental Organizations’ Psychosocial Support Programs In Jordan, Dina Abdalla Apr 2023

A Multi-Factorial Analysis Of The Sustainability Of Non-Governmental Organizations’ Psychosocial Support Programs In Jordan, Dina Abdalla

Independent Study Project (ISP) Collection

This research paper aims to explore the factors that affect the sustainability of psychosocial support (PSS) programs provided by non-governmental organizations (NGOs) in Jordan. NGOs in Jordan are facing a significant issue when it comes to the sustainability of their programs, and they provide crucial programs for refugees and underserviced populations. So, it is crucial to investigate the factors affecting and solutions to sustainability. It is hypothesized that sustainability is a multi- factorial concept, affected by financial, organizational, and environmental factors. It is predicted that NGO characteristics, program effectiveness, and program type can affect sustainability. To combat sustainability issues, it …

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Aesthetically Appealing Building Integrated Photovoltaic Systems For Net-Zero Energy Buildings. Current Status, Challenges, And Future Developments—A Review, Mohammad Khairul Basher, Mohammad Nur-E-Alam, Md Momtazur Rahman, Kamal Alameh, Steven Hinckley Apr 2023

Aesthetically Appealing Building Integrated Photovoltaic Systems For Net-Zero Energy Buildings. Current Status, Challenges, And Future Developments—A Review, Mohammad Khairul Basher, Mohammad Nur-E-Alam, Md Momtazur Rahman, Kamal Alameh, Steven Hinckley

Research outputs 2022 to 2026

With the sharp increase in global energy demand, industrial and residential buildings are responsible for around 40% of the energy consumed with most of this energy portion being generated by non-renewable sources, which significantly contribute to global warming and environmental hazards. The net-zero energy building (NZEB) concept attempts to solve the global warming issue, whereby a building will produce, on-site, its required energy demand throughout the year from renewable energy sources. This can be achieved by integrating photovoltaic (PV) building materials, called building-integrated photovoltaic (BIPV) modules, throughout the building skin, which simultaneously act as construction materials and energy generators. Currently, …

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Discovering Dune: Essays On Frank Herbert’S Epic Saga., Edited By Dominic J. Nardi And N. Trevor Brierly, G. Connor Salter Apr 2023

Discovering Dune: Essays On Frank Herbert’S Epic Saga., Edited By Dominic J. Nardi And N. Trevor Brierly, G. Connor Salter

Mythlore: A Journal of J.R.R. Tolkien, C.S. Lewis, Charles Williams, and Mythopoeic Literature

G. Connor Salter reviews Discovering Dune: Essays on Frank Herbert’s Epic Saga, edited by Dominic J. Nardi and N. Trevor Brierly, considering its new contributions to studies of Frank Herbert's work. Essays included fit into four categories (Politics and Power, History and Religion, Biology and Ecology, and Philosophy, Choice and Ethics) and range from Herbert's use of ecology in Dune to how game theory may help explain certain characters' apparent ability to see the future. Discovering Dune also includes an appendix which contains the only up-to-date bibliography of Herbert's work (primary and secondary sources).

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Counting Elliptic Curves With A Cyclic M-Isogeny Over Q, Grant S. Molnar Apr 2023

Counting Elliptic Curves With A Cyclic M-Isogeny Over Q, Grant S. Molnar

Dartmouth College Ph.D Dissertations

Using methods from analytic number theory, for m > 5 and for m = 4, we obtain asymptotics with power-saving error terms for counts of elliptic curves with a cyclic m-isogeny up to quadratic twist over the rational numbers. For m > 5, we then apply a Tauberian theorem to achieve asymptotics with power saving error for counts of elliptic curves with a cyclic m-isogeny up to isomorphism over the rational numbers.

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Regulating Artificial Intelligence In International Investment Law, Mark Mclaughlin Apr 2023

Regulating Artificial Intelligence In International Investment Law, Mark Mclaughlin

Research Collection Yong Pung How School Of Law

The interaction between artificial intelligence (AI) and international investment treaties is an uncharted territory of international law. Concerns over the national security, safety, and privacy implications of AI are spurring regulators into action around the world. States have imposed restrictions on data transfer, utilised automated decision-making, mandated algorithmic transparency, and limited market access. This article explores the interaction between AI regulation and standards of investment protection. It is argued that the current framework provides an unpredictable legal environment in which to adjudicate the contested norms and ethics of AI. Treaties should be recalibrated to reinforce their anti-protectionist origins, embed human-centric …

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Jwst’S Pearls: Dust Attenuation And Gravitational Lensing In The Backlit-Galaxy System Vv 191, William C. Keel, Rogier A. Windhorst, Rolf A. Jansen, Seth H. Cohen, Jake Summers, Benne Holwerda, Sarah T. Bradford, Clayton D. Robertson, Giovanni Ferrami, Stuart Wyithe, Haojing Yan, Christopher J. Conselice, Simon P. Driver, Aaron Robotham, Norman A. Grogin, Christopher N. A. Willmer, Anton M. Koekemoer, Brenda L. Frye, Nimish P. Hathi, Russell E. Ryan Jr., Nor Pirzkal, Madeline A. Marshall, Dan Coe, Jose M. Diego, Thomas J. Broadhurst, Michael J. Rutkowski, Lifan Wang, S. P. Willner, Andreea Petric, Cheng Cheng, Adi Zitrin Apr 2023

Jwst’S Pearls: Dust Attenuation And Gravitational Lensing In The Backlit-Galaxy System Vv 191, William C. Keel, Rogier A. Windhorst, Rolf A. Jansen, Seth H. Cohen, Jake Summers, Benne Holwerda, Sarah T. Bradford, Clayton D. Robertson, Giovanni Ferrami, Stuart Wyithe, Haojing Yan, Christopher J. Conselice, Simon P. Driver, Aaron Robotham, Norman A. Grogin, Christopher N. A. Willmer, Anton M. Koekemoer, Brenda L. Frye, Nimish P. Hathi, Russell E. Ryan Jr., Nor Pirzkal, Madeline A. Marshall, Dan Coe, Jose M. Diego, Thomas J. Broadhurst, Michael J. Rutkowski, Lifan Wang, S. P. Willner, Andreea Petric, Cheng Cheng, Adi Zitrin

Faculty and Staff Scholarship

We present the first JWST observations of the z = 4.11 luminous radio galaxy TN J1338–1942, obtained as part of the ‘Prime Extragalactic Areas for Reionization and Lensing Science’ (‘PEARLS’) project. Our NIRCam observations, designed to probe the key rest-frame optical continuum and emission line features at this redshift, enable resolved spectral energy distribution modelling that incorporates both a range of stellar population assumptions and radiative shock models. With an estimated stellar mass of log10(M/M⊙) ∼ 10.9, TN J1338–1942 is confirmed to be one of the most massive galaxies known at this epoch. Our observations also reveal extremely high equivalent-width …

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Galaxy And Mass Assembly (Gama): Low-Redshift Quasars And Inactive Galaxies Have Similar Neighbors, Maria B. Stone, Clare F. Wethers, Roberto De Propris, Jari Kotilainen, Nischal Acharya, Benne W. Holwerda, Jonathan Loveday, Steven Phillipps Apr 2023

Galaxy And Mass Assembly (Gama): Low-Redshift Quasars And Inactive Galaxies Have Similar Neighbors, Maria B. Stone, Clare F. Wethers, Roberto De Propris, Jari Kotilainen, Nischal Acharya, Benne W. Holwerda, Jonathan Loveday, Steven Phillipps

Faculty and Staff Scholarship

We explore the properties of galaxies in the proximity (within a ∼2 Mpc radius sphere) of Type I quasars at 0.1 <z <0.35, to check whether and how an active galaxy influences the properties of its neighbors. We further compare these with the properties of neighbors around inactive galaxies of the same mass and redshift within the same volume of space, using the Galaxy and Mass Assembly spectroscopic survey. Our observations reveal no significant difference in properties such as the number of neighbors, morphologies, stellar mass, star formation rates, and star formation history between the neighbors of quasars and those of the comparison sample. This implies that quasar activity in a host galaxy does not significantly affect its neighbors (e.g., via interactions with the jets). Our results suggest that quasar host galaxies do not strongly differ from the average galaxy within the specified mass and redshift range. Additionally, the implication of the relatively minor importance of the environmental effect on and from quasars is that nuclear activity is more likely triggered by internal and secular processes.

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Muon Intensity Measurement With The Majorana Demonstrator, Franklin Michael Adams Jr. Apr 2023

Muon Intensity Measurement With The Majorana Demonstrator, Franklin Michael Adams Jr.

Theses and Dissertations

The Majorana Demonstrator (MJD) is a shielded radiation detection system located a mile underground at the Sanford Underground Research Facility (SURF) in South Dakota. The system aims to detect the theorized, rare process of neutrinoless double-beta decay. The Demonstrator utilizes an array of scintillating acrylic detectors to veto any signals induced by earth-penetrating cosmogenic muons and reach background levels necessary for the detection of neutrinoless double-beta decay. Utilizing the data collected by the muon veto system, an analysis has been done to determine the differential muon intensity. The complex geometry of the interlacing detector panels requires the use of Monte …

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A Study Of Single Molecule Detection With Graphene Hall Bars, Kenneth Stephen Stephenson Apr 2023

A Study Of Single Molecule Detection With Graphene Hall Bars, Kenneth Stephen Stephenson

Theses and Dissertations

In 2007, detection of individual molecules with a solid-state gas sensor was reported for first time by Schedin et al. where they used micromechanically-cleaved graphene for their sensing material, which exhibits isotropic and homogeneous conduction [1]. However, despite the novelty and popularity of their work, it has never been repeated. Further, we found their associated calculations to be self-inconsistent by a factor of 103 . So, hoping to account for and resolve this discrepancy, we outline the plan we had to reproduce their experiment. We also justify any substantial modifications, particularly our choice to use epitaxial graphene instead. Then, we …

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Advancements In Parametric Modal Regression, Qingyang Liu Apr 2023

Advancements In Parametric Modal Regression, Qingyang Liu

Theses and Dissertations

This dissertation considers statistical inference methods for parametric modal regression models. In Chapter 1, we motivate the mode as the measure of central tendency instead of the median or the mean with an example. Following the motivational example, we include an overview of existing modal regression models. Later, in the same chapter, we explain advantages of the parametric modal regression models over existing nonparametric modal regression models. In Chapter 2, we address issues in statistical inference brought in by data contaminated with measurement error. With measurement error in covariates, statistical inference methods designed for modal regression models with error-free covariates …

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Detecting Spatially Varying Coefficient Effects With Conditional Autoregressive Models: A Simulation Study Using Social Determinants Of Health Screening Data, Reid J. Demass Apr 2023

Detecting Spatially Varying Coefficient Effects With Conditional Autoregressive Models: A Simulation Study Using Social Determinants Of Health Screening Data, Reid J. Demass

Theses and Dissertations

Generalized linear models which include spatially varying coefficient terms allow researchers to determine if the association between predictor and outcome variables vary across geographic space. Such models are particularly applicable to research with public health data where interventions and limited health care resources must be allocated carefully. The integrated nested Laplace approximation (INLA) methodology available in the R INLA package is a popular tool to estimate spatially varying coefficients. To assess the performance of the estimation procedure, patient emergency department (ED) visits were simulated from data sourced from a pilot study at Prisma Health. The INLA technique was used to …

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The Kinetic Control Of Polymer Micelles; Chemical Functionality, Material Interactions, And Equilibration, Taylor Larison Apr 2023

The Kinetic Control Of Polymer Micelles; Chemical Functionality, Material Interactions, And Equilibration, Taylor Larison

Theses and Dissertations

Polymer micelles have found significant uses in areas such as, energy storage devices, catalysis, opto-electronics, drug-delivery, oil additives, and nanoreactors. In many of these applications the overall micelle size (aggregation number) and chemical functionalization determines performance. To progress towards more advanced materials synthesized from the facile bottom-up approach with polymeric micelles the implementation and study of thermodynamic handles were investigated. Here the kinetic control of micelles was studied across a range of applications; independent control over micelle functionality, the spatial orientation of multiple metal oxide nanoparticles in mesoporous materials via self-assembly, and the use of small-angle neutron scattering (SANS) to …

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Coordination Environment And Thermodynamics Of Colloidal Quantum Dots In Polar Solvents, Nuwanthaka Prasad Jayaweera Millaniyage Apr 2023

Coordination Environment And Thermodynamics Of Colloidal Quantum Dots In Polar Solvents, Nuwanthaka Prasad Jayaweera Millaniyage

Theses and Dissertations

Colloidal semiconductor quantum dots (QDs) have been extensively investigated due to their attractive properties such as size-tunable absorption and emission spectra, large molar extinction coefficients, and significant photostability. These properties make them promising candidates for optoelectronic, photocatalytic, and biomedical applications. Common synthetic procedures of QDs produce nanocrystals capped with long-chain fatty acid derivatives which are stabilized in high boiling point solvents. Especially for bioimaging applications, the exchange of these native hydrophobic ligands with hydrophilic ligands should be performed, while preserving the smaller hydrodynamic radius. The coordination environment and thermodynamic parameters of the ligand exchanges should be carefully investigated to engineer …

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