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Articles 571 - 600 of 3168

Full-Text Articles in Physical Sciences and Mathematics

Observation Of Gravitational Waves From The Coalescence Of A 2.5–4.5 M⊙ Compact Object And A Neutron Star, A. Abac, R. Abbott, I. Abouelfettouh, F. Acernese, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Volker Quetschke, Wenhui Wang Aug 2024

Observation Of Gravitational Waves From The Coalescence Of A 2.5–4.5 M⊙ Compact Object And A Neutron Star, A. Abac, R. Abbott, I. Abouelfettouh, F. Acernese, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Volker Quetschke, Wenhui Wang

Physics & Astronomy Faculty Publications

We report the observation of a coalescing compact binary with component masses 2.5–4.5 M⊙ and 1.2–2.0 M⊙ (all measurements quoted at the 90% credible level). The gravitational-wave signal GW230529_181500 was observed during the fourth observing run of the LIGO–Virgo–KAGRA detector network on 2023 May 29 by the LIGO Livingston observatory. The primary component of the source has a mass less than 5 M⊙ at 99% credibility. We cannot definitively determine from gravitational-wave data alone whether either component of the source is a neutron star or a black hole. However, given existing estimates of the maximum neutron star mass, we find …


Temperature-Dependent Optical Constants Of Vanadium Dioxide Thin Films Deposited On Polar Dielectrics, Imtiaz Ahmad, Satya R. Kachiraju, Sundar Kunwar, Zachary M. Brown, Pinku Roy, Matthew Gaddy, Vladimir Kuryatkov, Yejin Kwon, Ayrton A. Bernussi, Myoung-Hwan Kim Aug 2024

Temperature-Dependent Optical Constants Of Vanadium Dioxide Thin Films Deposited On Polar Dielectrics, Imtiaz Ahmad, Satya R. Kachiraju, Sundar Kunwar, Zachary M. Brown, Pinku Roy, Matthew Gaddy, Vladimir Kuryatkov, Yejin Kwon, Ayrton A. Bernussi, Myoung-Hwan Kim

Physics & Astronomy Faculty Publications

Coating polar dielectrics with thin film vanadium dioxide (VO2) enables one to exploit the temperature-dependent phase transition within VO2 to actively tune and modulate surface phonon polaritons at mid-infrared. However, controlling the behavior of such systems requires intimate knowledge of the temperature-dependent optical constants of VO2, which depend greatly on the growth conditions and substrate material. Here, we accurately determine the complex optical constants of VO2 on polar dielectrics across the insulator-to-metal phase transition (IMT) using only normal incident reflectance spectra by analyzing the reflectance with Kramers–Kronig relations and thin film Fresnel equations. This non-ellipsometry technique offers an …


Microwave Spectroscopy And Large Amplitude Motion Of Chlorosulfonic Acid (Clso2oh), Aaron J. Reynolds, Diego E. Rodriguez, Wei Lin, Kenneth R. Leopold Aug 2024

Microwave Spectroscopy And Large Amplitude Motion Of Chlorosulfonic Acid (Clso2oh), Aaron J. Reynolds, Diego E. Rodriguez, Wei Lin, Kenneth R. Leopold

Physics & Astronomy Faculty Publications

The high-resolution rotational spectrum of chlorosulfonic acid (ClSO2OH) has been studied using both broadband and cavity-based Fourier transform microwave spectrometers over the frequency range of 5–18 GHz. a-, b-, and c-type transitions have been recorded for both the 35Cl and 37Cl isotopologues. The observation of c-type lines establishes that the molecule lacks a plane of symmetry and suggests that the OH group can undergo large amplitude motion between equivalent structures. Interconversion between these structures can be achieved via internal rotation through two inequivalent barriers occurring at Cl-S-O-H torsional angles of 0 or 180 degrees. As in …


Utilizing Unmanned Aerial Systems (Uas) And Computer Software To Assess Effects Of Cover Crops On Cash Crop Volumetric Mass And Plant Height, Carlos Andres Garcia Patlan Aug 2024

Utilizing Unmanned Aerial Systems (Uas) And Computer Software To Assess Effects Of Cover Crops On Cash Crop Volumetric Mass And Plant Height, Carlos Andres Garcia Patlan

Theses and Dissertations

Sustainability in agriculture starts with the health of soil-- from its productivity and fertility, to its ability to retain water during droughts and allow for drainage during rain. One approach of improving soil health is the use of cover crops, a practice associated with improved nutrient availability in soils, the promotion of soil biodiversity and organic matter to improve density and structure, effective weed management, and ultimately improved yields of subsequent cash crops. Assessing the cumulative impacts of cover crops is difficult, with various metrics and indicators. Crop dry weight may be a way to predict the effects cover crops …


Intrinsic Universality In Tile Automata And Related Results, Elise C. Grizzell Aug 2024

Intrinsic Universality In Tile Automata And Related Results, Elise C. Grizzell

Theses and Dissertations

The Tile Automata (TA) model describes self-assembly systems in which monomers can build structures and transition with an adjacent monomer to change their states. This paper shows that seeded TA is a non-committal intrinsically universal model of self-assembly. We present a single universal Tile Automata system containing approximately 4600 states that can simulate (a) the output assemblies created by any other Tile Automata system Γ, (b) the dynamics involved in building Γ’s assemblies, and (c) Γ’s internal state transitions. It does so in a non-committal way: it preserves the full non-deterministic dynamics of a tile’s potential attachment or transition by …


Increasing The Robustness Of Machine Learning By Adversarial Attacks, Gourab Mukhopadhyay Jul 2024

Increasing The Robustness Of Machine Learning By Adversarial Attacks, Gourab Mukhopadhyay

Theses and Dissertations

By perturbation or physical attacks any machine can be fooled into predicting something else other than the intended output. There are training data based on which the model is trained to predict unknown things. The objective was to create noises and shades of different levels on the images and do experiments for measuring accuracy and making the model classify the traffic signs. When it comes to adding shades to the pictures, pixels were modified for three different layers of the pictures. The experiment also shows that with the shadows getting deeper, the accuracies drop significantly. Here, some changes in pixels …


Nilpotent Global Centers Of Generalized Polynomial Kukles System With Degree Three, Hebai Chen, Zhaosheng Feng, Rui Zahg Jul 2024

Nilpotent Global Centers Of Generalized Polynomial Kukles System With Degree Three, Hebai Chen, Zhaosheng Feng, Rui Zahg

School of Mathematical & Statistical Sciences Faculty Publications

In this paper, we study and characterize the nilpotent global centers of a generalized polynomial Kukles system with degree three. A sufficient and necessary condition of global centers is established under certain parametric conditions.


Answers To Frequently Asked Questions About The Pulsar Timing Array Hellings And Downs Curve, Joseph D. Romano, Bruce Allen Jul 2024

Answers To Frequently Asked Questions About The Pulsar Timing Array Hellings And Downs Curve, Joseph D. Romano, Bruce Allen

Physics & Astronomy Faculty Publications

We answer frequently asked questions (FAQs) about the Hellings and Downs correlation curve—the ‘smoking-gun’ signature that pulsar timing arrays (PTAs) have detected gravitational waves (GWs). Many of these questions arise from inadvertently applying intuition about the effects of GWs on LIGO-like detectors to the case of pulsar timing, where not all of it applies. This is because Earth-based detectors, like LIGO and Virgo, have arms that are short (km scale) compared to the wavelengths of the GWs that they detect (≈102–104 km). In contrast, PTAs respond to GWs whose wavelengths (tens of light-years) are much shorter than their arms (a …


Personalized Driving Using Inverse Reinforcement Learning, Rodrigo J. Gonzalez Salinas Jul 2024

Personalized Driving Using Inverse Reinforcement Learning, Rodrigo J. Gonzalez Salinas

Theses and Dissertations

This thesis introduces an autonomous driving controller designed to replicate individual driving behaviors based on a provided demonstration. The controller employs Inverse Reinforcement Learning (IRL) to formulate the reward function associated with the provided demonstration. IRL is implemented through a dual-feedback loop system. The inner loop utilizes Q-learning, a model-free reinforcement learning technique, to optimize the Hamilton-Jacobi-Bellman (HJB) equation and derive an appropriate control solution. The outer loop leverages this derived control solution to generate parameters for the reward function, which are subsequently integrated into the HJB equation. The ultimate control policy is deduced from the final reward function obtained …


Glitch Veto Based On Unphysical Gravitational Wave Binary Inspiral Templates, Raghav Girgaonkar, Soumya D. Mohanty Jul 2024

Glitch Veto Based On Unphysical Gravitational Wave Binary Inspiral Templates, Raghav Girgaonkar, Soumya D. Mohanty

Physics & Astronomy Faculty Publications

Transient signals arising from instrumental or environmental factors, commonly referred to as glitches, constitute the predominant background of false alarms in gravitational wave searches with ground-based detectors. Therefore, effective data analysis methods for vetoing glitch-induced false alarms are crucial to enhancing the sensitivity of a search. We present a veto method for glitches that impact matched filtering-based searches for binary inspiral signals. The veto uses unphysical sectors in the space of chirp time parameters as well as an unphysical extension including negative chirp times to efficiently segregate glitches from gravitational wave signals in data from a single detector. Inhabited predominantly …


Detection And Mitigation Of Misleading Pheromone Trails In Foraging Robot Swarms, Ryan Luna, Qi Lu Jul 2024

Detection And Mitigation Of Misleading Pheromone Trails In Foraging Robot Swarms, Ryan Luna, Qi Lu

Computer Science Faculty Publications

This study addresses the overlooked aspect of security in swarm robotics by exploring the vulnerabilities of stigmergic communication in foraging robot swarms. More specifically, we study the swarm's susceptibility to attacks that introduce misleading pheromone trails. Simulated scenarios in which detractor robots lay misleading trails to deceive benign foraging robots effectively reduce the foraging performance of the swarm. We analyze the impact of the attack on the swarm and evaluate the reduction of foraging efficiency. We introduce a defense mechanism using distance-based clustering (DBSCAN) along with a cluster grouping method to isolate large batches of detractors early in the simulation. …


Tuning Pid Controller For Quadrotor Using Particle Swarm Optimization, Eric X. Rodriguez, Qi Lu Jul 2024

Tuning Pid Controller For Quadrotor Using Particle Swarm Optimization, Eric X. Rodriguez, Qi Lu

Computer Science Faculty Publications

Energy expenditure for quadrotor control has a likelihood of being costly given parameter-dependent controllers that are less than optimal. The cost can grow proportionally when applied to multiple quadrotors for tracking and collaborative navigation tasks. This research aims to establish a basic approach to tuning PID (Proportional-Integral-Derivative) parameters for a simulated quadrotor drone. A PID controller for autonomy provides a straightforward method for correcting robotic movement based on its current state. However, applying a PID system to a flight controller poses challenges with an inherently under-actuated system, which includes the likelihood of large overshoots and lengthy adjustment times. To address …


Variable Radio Emission Of Neutron Star X-Ray Binary Ser X–1 During Its Persistent Soft State, Eli C. Pattie, Thomas J. Maccarone, Alexandra J. Tetarenko, James C. A. Miller-Jones, Manuel Pichardo Marcano, Liliana E. Rivera Sandoval Jul 2024

Variable Radio Emission Of Neutron Star X-Ray Binary Ser X–1 During Its Persistent Soft State, Eli C. Pattie, Thomas J. Maccarone, Alexandra J. Tetarenko, James C. A. Miller-Jones, Manuel Pichardo Marcano, Liliana E. Rivera Sandoval

Physics & Astronomy Faculty Publications

Ser X–1 is a low-mass neutron star X-ray binary and has been persistently accreting since its discovery in the 1960s. It has always been observed to be in a soft spectral state and has never showed substantial long-term X-ray variability. Ser X–1 has one previous radio observation in the literature in which radio emission was detected during this soft state, which is contrary to the behavior of black hole X-ray binaries. We have recently obtained 10 randomly sampled radio epochs of Ser X–1 in order to further investigate its anomalous soft-state radio emission. Out of 10 epochs, we find 8 …


The Arbitrariness Of Symmetry In Mathematical Proofs, Melisa Vivanco Jul 2024

The Arbitrariness Of Symmetry In Mathematical Proofs, Melisa Vivanco

Philosophy Faculty Publications

Symmetry is not an inherent characteristic of mathematical proofs; instead, it is a property that arbitrarily manifests in different modes of presentation. This arbitrariness leads to the conclusion that symmetry cannot be part of the defining or essential properties that characterize proofs. Consequently, contrary to some authors’ claims, symmetry does not significantly contribute to the validity, accuracy, or soundness of mathematical proofs. What is more, it does not even play any critical role in heuristic aspects such as explanatory power. The examples developed in this paper constitute compelling evidence supporting these claims.


Calibrating The Global Network Of Gravitational Wave Observatories Via Laser Power Calibration At Nist And Ptb, Dripta Bhattacharjee, Richard Lenox Savage, Rishabh Bajpai, Joseph Betzwieser, Vladimir Bossilkov, Dan Chen, Cervane Grimaud, Shingo Hido, Sudarshan Karki, Francisco Llamas Jul 2024

Calibrating The Global Network Of Gravitational Wave Observatories Via Laser Power Calibration At Nist And Ptb, Dripta Bhattacharjee, Richard Lenox Savage, Rishabh Bajpai, Joseph Betzwieser, Vladimir Bossilkov, Dan Chen, Cervane Grimaud, Shingo Hido, Sudarshan Karki, Francisco Llamas

Physics & Astronomy Faculty Publications

Current gravitational wave (GW) observatories rely on photon calibrators that use laser radiation pressure to generate displacement fiducials used to calibrate detector output signals. Reducing calibration uncertainty enables optimal extraction of astrophysical information such as source distance and sky position from detected signals. For the ongoing O4 observing run that started on 24 May 2023, the global GW detector network is employing a new calibration scheme with transfer standards calibrated at both the National Institute of Standards and Technology (NIST) and the Physikalisch-Technische Bundesanstalt (PTB). These transfer standards will circulate between the observatories and the metrology institutes to provide laser …


Constrained Quantization For The Cantor Distribution, Megha Pandey, Mrinal Kanti Roychowdhury Jul 2024

Constrained Quantization For The Cantor Distribution, Megha Pandey, Mrinal Kanti Roychowdhury

School of Mathematical & Statistical Sciences Faculty Publications

The theory of constrained quantization has been recently introduced by Pandey and Roychowdhury. In this paper, they have further generalized their previous definition of constrained quantization and studied the constrained quantization for the classical Cantor distribution. Toward this, they have calculated the optimal sets of n-points, nth constrained quantization errors, the constrained quantization dimensions, and the constrained quantization coefficients, taking different families of constraints for all n∈N. The results in this paper show that both the constrained quantization dimension and the constrained quantization coefficient for the Cantor distribution depend on the underlying constraints. It also shows that the constrained quantization …


Road Mitigation Structures Designed For Texas Ocelots: Influence Of Structural Characteristics And Environmental Factors On Non-Target Wildlife Usage, Anna Rivera Roy, Kevin W. Ryer, Md. Saydur Rahman, John H. Young Jr., Richard J. Kline Jul 2024

Road Mitigation Structures Designed For Texas Ocelots: Influence Of Structural Characteristics And Environmental Factors On Non-Target Wildlife Usage, Anna Rivera Roy, Kevin W. Ryer, Md. Saydur Rahman, John H. Young Jr., Richard J. Kline

School of Earth, Environmental, & Marine Sciences Faculty Publications

Roads negatively impact wildlife through habitat fragmentation, loss of habitat connectivity, and wildlife-vehicle collisions, thus road mitigation structures, such as wildlife crossing structures (WCS), wildlife guards (WG), and fencing are commonly used to address this issue all over the world, including in the United States. In South Texas, such structures were built or modified along a State Highway in an effort to address road mortality for the endangered ocelot (Leopardus pardalis) and non-target wildlife species. The goal of this study was to examine temporal changes in wildlife interactions with WCS and WG during and after their construction and …


Red Harvester Ant, Pogonomyrmex Barbatus, Nests Impact Soil Compaction But Not Temperature In Peri-Urban Habitats Of The Lower Rio Grande Valley, Geovanni Hernandez, Hannah J. Penn, Richard Cano, Lilly Victoria Elliott-Vidaurri, Robin A. Choudhury Jul 2024

Red Harvester Ant, Pogonomyrmex Barbatus, Nests Impact Soil Compaction But Not Temperature In Peri-Urban Habitats Of The Lower Rio Grande Valley, Geovanni Hernandez, Hannah J. Penn, Richard Cano, Lilly Victoria Elliott-Vidaurri, Robin A. Choudhury

School of Earth, Environmental, & Marine Sciences Faculty Publications

Ants are vital ecosystem engineers that can influence soil properties, subsequent soil processes, and associated biota via underground nest construction. Harvester ants consume seeds and are often found in arid areas. They frequently alter the soil chemistry and bulk density of the soils in and around their nest sites. Many species of harvester ants also intentionally remove vegetation around their nest openings, which creates cones or discs of bare soil that may further alter soil temperatures. However, much of the work to study the impacts of harvester ants on soil properties has occurred in shrubland and grassland settings rather than …


Future Climate Doubles The Risk Of Hydraulic Failure In A Wet Tropical Forest, Zachary Robbins, Jeffrey Chambers, Rutuja Chitra-Tarak, Bradley O. Christoffersen, L. Turin Dickman, Rosie Fisher, Alex Jonko, Ryan Knox, Charles Koven, Lara Kueppers Jul 2024

Future Climate Doubles The Risk Of Hydraulic Failure In A Wet Tropical Forest, Zachary Robbins, Jeffrey Chambers, Rutuja Chitra-Tarak, Bradley O. Christoffersen, L. Turin Dickman, Rosie Fisher, Alex Jonko, Ryan Knox, Charles Koven, Lara Kueppers

School of Integrative Biological & Chemical Sciences Faculty Publications

Summary

  • Future climate presents conflicting implications for forest biomass. We evaluate how plant hydraulic traits, elevated CO2 levels, warming, and changes in precipitation affect forest primary productivity, evapotranspiration, and the risk of hydraulic failure.
  • We used a dynamic vegetation model with plant hydrodynamics (FATES-HYDRO) to simulate the stand-level responses to future climate changes in a wet tropical forest in Barro Colorado Island, Panama. We calibrated the model by selecting plant trait assemblages that performed well against observations. These assemblages were run with temperature and precipitation changes for two greenhouse gas emission scenarios (2086–2100: SSP2-45, SSP5-85) and two CO2 levels (contemporary, …


Multi-Symplectic Method For The Two-Component Camassa–Holm (2ch) System, Xiaojian Xi, Weipeng Hu, Bo Tang, Pingwei Deng, Zhijun Qiao Jul 2024

Multi-Symplectic Method For The Two-Component Camassa–Holm (2ch) System, Xiaojian Xi, Weipeng Hu, Bo Tang, Pingwei Deng, Zhijun Qiao

School of Mathematical & Statistical Sciences Faculty Publications

In this paper, the multi-symplectic formulations of the two-component Camassa–Holm system are presented. Both the multi-symplectic structure and two local conservation laws of the generalized two-component Camassa–Holm model are proposed for its first-order canonical form. Then, combining the Fourier pseudo-spectral method in the spatial domain with the midpoint method in the time dimension, the multi-symplectic Fourier pseudo-spectral scheme is constructed for the first-order canonical form. Meanwhile, the discrete scheme of the residuals of the multi-symplectic structure and two local conservation laws are also provided. By using the multi-symplectic Fourier pseudo-spectral scheme, the evolution of one- and two-soliton solutions for the …


P-Adic Quantum Mechanics, The Dirac Equation, And The Violation Of Einstein Causality, Wilson A. Zuniga-Galindo Jul 2024

P-Adic Quantum Mechanics, The Dirac Equation, And The Violation Of Einstein Causality, Wilson A. Zuniga-Galindo

School of Mathematical & Statistical Sciences Faculty Publications

This article studies the breaking of the Lorentz symmetry at the Planck length in quantum mechanics. We use three-dimensional ℘-adic vectors as position variables, while the time remains a real number. In this setting, the Planck length is 1/℘, where ℘ is a prime number, and the Lorentz symmetry is naturally broken. In the framework of the Dirac-von Neumann formalism for quantum mechanics, we introduce a new ℘-adic Dirac equation that predicts the existence of particles and antiparticles and charge conjugation like the standard one. The discreteness of the ℘-adic space imposes substantial restrictions on the solutions of the new …


Controlling Adversarial Pheromone-Based Infections Via Quarantine Strategies In Foraging Robot Swarms, Ryan Luna, Qi Lu Jul 2024

Controlling Adversarial Pheromone-Based Infections Via Quarantine Strategies In Foraging Robot Swarms, Ryan Luna, Qi Lu

Computer Science Faculty Publications

Virtual pheromone trails that facilitate efficient and adaptable coordination among foraging robot swarms are vulnerable to threats that exploit stigmergic communication. This study investigates the impact of a fake resource attack on the performance of a pheromone-based foraging algorithm and demonstrates the effectiveness of a “quarantine strategy” in mitigating the attack. The study simulates the fake resources and examines the swarm's behavior as robots are attracted to these fake resource locations. To prevent access to fake resources, circular quarantine regions are deployed, and a distance-based merging algorithm is implemented to reduce storage require-ments. The experiments are conducted with varying numbers …


Agenda De Investigación Para El Manejo Sustentable Del Manglar En Tamaulipas, México [Research Agenda For The Sustainable Management Of Mangroves In Tamaulipas, Mexico], Carlos Zamora-Tovar, Alejandro Fierro-Cabo, Glenda Nelly Requena-Lara Jul 2024

Agenda De Investigación Para El Manejo Sustentable Del Manglar En Tamaulipas, México [Research Agenda For The Sustainable Management Of Mangroves In Tamaulipas, Mexico], Carlos Zamora-Tovar, Alejandro Fierro-Cabo, Glenda Nelly Requena-Lara

School of Earth, Environmental, & Marine Sciences Faculty Publications

Se presenta un análisis de la información ecológica disponible sobre los manglares de Tamaulipas, México. El objetivo fue establecer una línea base de conocimiento que defina el estado del arte a partir de la información publicada; actualizar la estructura forestal con datos propios observados en el año 2018; y determinar una agenda de investigación prioritaria para el manejo sostenible del ecosistema de man-glar, ecosistema de vital importancia por la gran variedad de recursos y servicios ambientales que aporta a la sociedad. La investigación bibliográfica recopiló 32 trabajos relevantes: 16 publicaciones formales, siete ediciones institucionales y nueve consideradas literaturas gris; recopilación …


Chief Sustainability Officer’S Role Centrality And Corporate Sustainability Performance, Taiwo Abraham, Gabriel Owusu, Xuan Wang Jul 2024

Chief Sustainability Officer’S Role Centrality And Corporate Sustainability Performance, Taiwo Abraham, Gabriel Owusu, Xuan Wang

Management Faculty Publications

Corporate Sustainability Performance (CSP) has gained substantial attention as firms recognize its potential impact on competitive advantage. In response, there has been a significant increase in the appointment of Chief Sustainability Officers (CSOs) tasked with managing sustainability performance and integrating systemic sustainability initiatives for business growth. In this research, we draw upon upper echelon theory and social network theory to argue that merely having a CSO does not enhance CSP. However, the centrality of CSO within organizational networks significantly augments CSP. Further, leveraging literature from institutional theory and stakeholder theory, we provide a fresh perspective on how organizations should approach …


Valorization Of Seafood Waste For Food Packaging Development, Zhijing Zhan, Yiming Feng, Jikai Zhao, Mingyu Qiao, Qing Jin Jul 2024

Valorization Of Seafood Waste For Food Packaging Development, Zhijing Zhan, Yiming Feng, Jikai Zhao, Mingyu Qiao, Qing Jin

School of Earth, Environmental, & Marine Sciences Faculty Publications

Packaging plays a crucial role in protecting food by providing excellent mechanical properties as well as effectively blocking water vapor, oxygen, oil, and other contaminants. The low degradation of widely used petroleum-based plastics leads to environmental pollution and poses health risks. This has drawn interest in renewable biopolymers as sustainable alternatives. The seafood industry generates significant waste that is rich in bioactive substances like chitin, chitosan, gelatins, and alginate, which can replace synthetic polymers in food packaging. Although biopolymers offer biodegradability, biocompatibility, and non-toxicity, their films often lack mechanical and barrier properties compared with synthetic polymer films. This comprehensive review …


The Fishing Cat: New Insights On Distribution In The Northern Sector Of Chitwan National Park, Nepal, Rupesh Maharjan, Rama Mishra, Jhamak Bahadur Karki Jul 2024

The Fishing Cat: New Insights On Distribution In The Northern Sector Of Chitwan National Park, Nepal, Rupesh Maharjan, Rama Mishra, Jhamak Bahadur Karki

School of Earth, Environmental, & Marine Sciences Faculty Publications

Fishing cat Prionailurus viverrinus (Bennett, 1833) is an elusive and medium-sized feline species with distinguished marking patterns on their head and body separating them from other feline species. Despite being distributed widely among diverse geographic locations, their abundance has declined due to significant habitat loss and human disturbances. There exists a substantial research gap regarding their abundance and distribution in Nepal. In this article, we presented the updated documentation of the fishing cat distribution in the northern sector of Chitwan National Park through our species-focused camera trapping survey. The study was carried out between April and May 2021 with a …


Beta Lactams Anticancer Effect On Human Breast Cancer, Mcf-7 Cell Line, Ailis A. Abalos Jul 2024

Beta Lactams Anticancer Effect On Human Breast Cancer, Mcf-7 Cell Line, Ailis A. Abalos

Theses and Dissertations

Cancer is a disease where abnormal cells replicate uncontrollably in that same region and/or other parts of the body. One in eight women are diagnosed with breast cancer, thus making it the second leading cause of cancer-related deaths in the U.S. Chemotherapy, is the utilization of medicinal compounds (drugs) to treat cancer. While most are nonspecific and target both cancer and healthy cells, more emphasis is on developing drugs with specificity (only target tumor cells) and low toxicity. Interestingly, Beta Lactams (β-lactams) have emerged as a class of compounds that are effective in the treatment of various cancers. The benefits …


Modulating Covalency In A Ni-H-Al Subunit: Synthesis And Characterization Of A Series Of Electronically Differentiating Ni-Al Heterometallics, Aleida Guadalupe Gonzalez Jul 2024

Modulating Covalency In A Ni-H-Al Subunit: Synthesis And Characterization Of A Series Of Electronically Differentiating Ni-Al Heterometallics, Aleida Guadalupe Gonzalez

Theses and Dissertations

Metal hydrides are moieties that are present in a variety of applications as intermediates in catalysis. Despite the vast utilization of metal hydrides, monometallic metal hydride complexes bear limitations in inert-bond activation and functionalization. A strategy to overcome these limitations and access more challenging reactivity is utilizing metal-metal cooperativity on a single platform to further activate hydride moieties. Although incorporating multiple metal centers on a single ligand scaffold has been realized, access to heterometallic hydride-bearing complexes is a greater synthetic challenge. Given the limitations in accessing such systems, the reactivity and electronic structure of heterometallic hydrides are seldom studied. Recently, …


A Deep Dive Into The Conformations Of Fluorine-Substituted Benzoic Acids And Ethanesulfonic Acid And Spectroscopic Characterizations Of Their Hydrogen-Bonded Complexes, Alitza Gianina Gracia Jul 2024

A Deep Dive Into The Conformations Of Fluorine-Substituted Benzoic Acids And Ethanesulfonic Acid And Spectroscopic Characterizations Of Their Hydrogen-Bonded Complexes, Alitza Gianina Gracia

Theses and Dissertations

Microwave spectroscopy is a technique used to study the molecular structures of a wide range of systems. The first part of the thesis focuses on fluorinated benzoic acids and complexes they form through hydrogen bonding to explore the fluorination effect, while the last part shifts to ethanesulfonic acid and its interaction with water. The study of 3,4,5-triflurorbenzoic acid with formic acid offers insight on the proton tunneling process, which is a process that occurs in many chemical and biological processes. Microwave spectroscopy can help provide dynamic information for the better understanding of this fundamental process. Solvation is another topic that …


Conditional Optimal Sets And The Quantization Coefficients For Some Uniform Distributions, Evans Nyanney Jul 2024

Conditional Optimal Sets And The Quantization Coefficients For Some Uniform Distributions, Evans Nyanney

Theses and Dissertations

Bucklew and Wise (1982) established that the quantization dimension of an absolutely continuous probability measure on a Euclidean space equals the Euclidean dimension of the space, and that the quantization coefficient is finite and positive. This thesis explores the variability of quantization coefficients for uniform distributions on various geometric structures, including line segments, circles, and regular polygons. We derive the conditional optimal sets of n-points and calculate the n-th conditional quantization errors for uniform distributions under different conditions. On line segments, we identify optimal point distributions as either equally spaced or geometrically spaced towards fixed end-points. For circles, we analyze …