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Articles 34231 - 34260 of 294517

Full-Text Articles in Physical Sciences and Mathematics

Complexity, Entanglement And Codes In Quantum Field Theory, Nikolaos Angelinos Jan 2024

Complexity, Entanglement And Codes In Quantum Field Theory, Nikolaos Angelinos

Theses and Dissertations--Physics and Astronomy

In recent decades many deep connections between quantum information theory and quantum field theory have been unearthed. In this dissertation we study topics in high-energy physics through the lens of quantum information: 1) We develop connections between error-correcting codes and Narain conformal field theories. 2) We study the entanglement entropy of one-dimensional fermionic chains with long-range interactions. 3) We study the temperature dependence of Lanczos coefficients and Krylov complexity.


Topics In Quantum Information, Complexity And Chaos, Debarghya Chakraborty Jan 2024

Topics In Quantum Information, Complexity And Chaos, Debarghya Chakraborty

Theses and Dissertations--Physics and Astronomy

This dissertation explores quantum information, the use of codes to describe quantum field theories, and introduces new concepts to characterize the dynamics of quantum many-body systems. The contributions of this dissertation are the following: 1) We constructed Narain Conformal Field Theories (CFTs) using additive codes, where the modular bootstrap constraints translate into algebraic conditions on the codes, extending previous approaches. This helps express key CFT data, including the torus partition function, in terms of codewords. We constructed optimal Narain CFTs for small central charges, and described CFT ensembles for asymptotically large central charge with large spectral gap. 2) We studied …


การอัตโนมัติกระแสงานของระบบการจัดการเนื้อหาด้วยพาวเวอร์ออโตเมต, อภิญญา แขนสูงเนิน Jan 2024

การอัตโนมัติกระแสงานของระบบการจัดการเนื้อหาด้วยพาวเวอร์ออโตเมต, อภิญญา แขนสูงเนิน

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้นำเสนอการพัฒนาระบบอัตโนมัติกระแสงานของระบบจัดการเนื้อหา หรือ ซีเอ็มเอส โดยใช้ ไมโครซอฟต์ พาวเวอร์ ออโตเมต และ เอไอ บิวเดอร์ บูรณาการกับ สตราพี ซีเอ็มเอส และ แชร์พอยต์ เพื่อเพิ่มประสิทธิภาพ ลดความผิดพลาดจากการดำเนินงานด้วยมือ และยกระดับความคล่องตัวในองค์กร กระแสงานที่พัฒนาแชร์พอยต์ประกอบด้วยการบูรณาการเว็บฮุก ของ สตราพี ซีเอ็มเอส เพื่อเริ่มต้นกระบวนการอัตโนมัติ การตรวจสอบความถูกต้องของเนื้อหาด้วยเอไอ บิวเดอร์ การบันทึกข้อมูลเหตุการณ์และข้อผิดพลาดในแชร์พอยต์ อีกทั้งการแจ้งเตือนผ่านไมโครซอฟท์ ทีม นอกจากนี้ ยังมีการใช้ จีพีที 4.0 สำหรับการวิเคราะห์บันทึกข้อผิดพลาด เพื่อเสนอแนวทางแก้ไขและปรับปรุงกระบวนการ ผลการทดลองในธนาคารพาณิชย์ไทยแห่งหนึ่งแสดงให้เห็นว่าสามารถลดระยะเวลาในการจัดการเนื้อหาได้ร้อยละ 87.5 และลดข้อผิดพลาดจากการป้อนข้อมูลได้ร้อยละ 80 เมื่อเทียบกับการทำงานแบบเดิมด้วยมนุษย์ งานวิจัยนี้ได้เน้นให้เห็นถึงศักยภาพของการใช้เทคโนโลยีดิจิทัลที่นำไปสู่โซลูชันการอัตโนมัติระบบการจัดการเนื้อหาที่เป็นรูปธรรม


Structure Identification For High-Dimensional Data In The Vicinity Of Bear Lake, Ben Shaw, Haley Burger, Brennan L. Bean, Kevin R. Moon Jan 2024

Structure Identification For High-Dimensional Data In The Vicinity Of Bear Lake, Ben Shaw, Haley Burger, Brennan L. Bean, Kevin R. Moon

Mathematics and Statistics Faculty Publications

This report focuses on seven water quality measurements taken at 43 different depths on the Bear Lake, Utah-Idaho for the months of June - November in the years 2018 - 2023. These measurements create a high-dimensional dataset on which we apply state-of-the-art machine learning (ML) techniques to look for low-dimensional structure in the data. A similar effort was made for weather measurements taken near the lake. Our analysis reveals that water quality measurements tend to cluster (i.e., group together) by year, while weather measurements tend to cluster by time of the year. This in mind, we explore potential drivers of …


Learning To Code With Github Copilot: A Resource For New Student Developers, Sarah Zelikovitz Jan 2024

Learning To Code With Github Copilot: A Resource For New Student Developers, Sarah Zelikovitz

Open Educational Resources

This resource provides a step-by-step guide for new student developers on using GitHub Copilot. It covers the process of signing up for GitHub's Educa􀀁on program, integra􀀁ng Copilot into two popular integrated development environments (IDEs), and using Copilot to generate, document, debug, and optimize code through prompt-based interactions. This guide empowers students to leverage AI-driven assistance in solving coding challenges. It also gives students an understanding of the limitations of AI, and how to use it safely and effectively.


Magnetic Spin Transport Coils For The N2edm Experiment, David C. Bowles Jan 2024

Magnetic Spin Transport Coils For The N2edm Experiment, David C. Bowles

Theses and Dissertations--Physics and Astronomy

The n2EDM experiment is being construct at Paul Scherrer Institute to measure the electric dipole moment of the neutron (nEDM), in a search for new physics which could help explain the baryon asymmetry of the universe. To reach the experimental sensitivity goal of $d_n \sim 10^{-27}$, over an order of magnitude improvement from the current world limit, a spin polarization transfer efficiency of 99\% for ultracold neutrons entering or exiting the precession chamber is required, placing a stringent requirement on the adiabaticity of the magnetic field taper in the neutron guide system. The spin transport fields transition from 5~T (longitudinal) …


Qcd Analysis Of Flavor-Nonchanging Hadronic Weak Processes Through Next-To-Leading Order, Girish Lingadahalli Muralidhara Jan 2024

Qcd Analysis Of Flavor-Nonchanging Hadronic Weak Processes Through Next-To-Leading Order, Girish Lingadahalli Muralidhara

Theses and Dissertations--Physics and Astronomy

Studies in quantum chromodynamics (QCD), the fundamental theory of the strong interactions, of low-energy hadronic weak processes utilize an effective Hamiltonian framework. Below the weak-mass scale, an effective Hamiltonian contains a series of Wilson coefficients and four-quark operators that come from the operator product expansion in the Standard Model. The effective hadronic Hamiltonian pertinent to a weak process is then obtained via a renormalization group analysis in QCD from the weak-mass scale to the low-energy scale of O(2 GeV). In this thesis, the construction and phenomenological implications of such an effective Hamiltonian for flavor-conserving, parity-violating quark processes in the Standard …


Exploring The Hot And Gaseous Universe From Infrared To X-Ray, Chamani Gunasekera Jan 2024

Exploring The Hot And Gaseous Universe From Infrared To X-Ray, Chamani Gunasekera

Theses and Dissertations--Physics and Astronomy

Over 90% of baryonic matter in the universe exists as astrophysical plasmas. The gas
is often far from thermodynamic equilibrium, so numerical non-equilibrium spectral
synthesis simulations are used to understand observations. cloudy simulates vari-
ous physical conditions, providing spectra predictions. This thesis aims to meet the
challenge of new observatories like the JWST (James Webb Space Telescope) and
XRISM (X-Ray Imaging Spectroscopy Mission). These simulations are no better
than the underlying atomic and molecular database and the fourth chapter details
a long-needed update to an evolving database. The predicted spectra are strongly
affected by the composition of the gas, which …


Techniques For Optimizing Neutron Beta Decay Particle Detection, Austin W. Nelsen Jan 2024

Techniques For Optimizing Neutron Beta Decay Particle Detection, Austin W. Nelsen

Theses and Dissertations--Physics and Astronomy

Over the last couple decades, use of free neutron beta decay (n → p + e- + νe) to extract the up-down quark transition element Vud has become competitive with more conventional Fermi decays. Extraction of Vud requires measurements of the vector to axial-vector coupling constant ratio λ and the free neutron lifetime τn. With a precise determination of Vud, the 2.8σ departure from CKM unitarity can be addressed.

Nab, located at the Spallation Neutron Source at ORNL, will measure the electron-neutrino momentum correlation coefficient a (which couples quadratically …


Spinning Spheroidal Components Of Disk Galaxies: Resonant Interactions With Stellar Bars, Xingchen Li Jan 2024

Spinning Spheroidal Components Of Disk Galaxies: Resonant Interactions With Stellar Bars, Xingchen Li

Theses and Dissertations--Physics and Astronomy

The majority of disk galaxies possess stellar bars, which are the main driver in the internal evolution of barred galaxies. Bars represent non-axisymmetric perturbations in the galactic disks, producing strong gravitational torques that facilitate angular momentum transfer from the disk to the spheroidal components, such as central stellar bulges and host dark matter (DM) halos. The redistribution of angular momentum in barred galaxies proceeds mainly via resonant interactions between the bar and orbits in the spheroids. The amount of angular momentum emitted or absorbed at each resonance depends on the mass distribution, density and spin in the spheroidal components. Thus, …


Development Of A Source To Detector Simulation Of The Los Alamos National Lab Neutron Electric Dipole Moment Experiment, Dillon Buskirk Jan 2024

Development Of A Source To Detector Simulation Of The Los Alamos National Lab Neutron Electric Dipole Moment Experiment, Dillon Buskirk

Theses and Dissertations--Physics and Astronomy

The Los Alamos National Laboratory (LANL) neutron electric dipole moment (nEDM) experiment is planning an increased precision measurement of the neutron’s permanent electric dipole moment. LANL nEDM expects to lower the statistical uncertainty to δdLANL = 2 × 10−27 e cm after a year of live-time, which puts a more stringent upper bound on the nEDM. This statistical uncertainty is an order of magnitude less than the current best measurement set by nEDM at PSI. To reach this goal, the LANL nEDM collaboration requires a simulation tool that can tackle optimization problems, investigate systematic effects, and provide mock data …


Development Of A Novel Beam-Type Neutron Lifetime Experiment Using Ultracold Neutrons, Nicholas Floyd Jan 2024

Development Of A Novel Beam-Type Neutron Lifetime Experiment Using Ultracold Neutrons, Nicholas Floyd

Theses and Dissertations--Physics and Astronomy

Precision measurements of the neutron lifetime are critical to tests of the Standard Model. The CKM quark mixing matrix has recently been shown to deviate from unitarity in the top row, motivating the development of alternative extractions of the first element. Complementary measurements of the neutron’s lifetime and decay correlations can be used to accomplish this.

While the reported neutron lifetime by the Particle Data Group is taken from ultracold neutron (UCN) measurements, a separate class of experiments suggest a value in four sigma disagreement, meriting further study. The goal of the UCNProBe experiment at Los Alamos National Laboratory is …


The Application Of Novel Machine Learning Algorithms To Study Multi-Dimensional Fragmentation Functions Of Hadrons In Jets At Star, Hannah A. Harrison-Smith Jan 2024

The Application Of Novel Machine Learning Algorithms To Study Multi-Dimensional Fragmentation Functions Of Hadrons In Jets At Star, Hannah A. Harrison-Smith

Theses and Dissertations--Physics and Astronomy

Hadronization, the process by which colored quarks and gluons shower from high energy collisions and recombine to form stable, experimentally-observable particles, is a fundamental aspect of Quantum Chromodynamics (QCD) that is not yet fully understood. Fragmentation functions, typically measured in electron-positron collisions, encapsulate this hadronization process well for quarks. Studying proton-proton collisions offers direct access to gluon fragmentation that other channels like electron-positron do not. Recent theoretical developments have proposed the study of hadronic showers in groupings called jets, introducing the concept of multi-dimensional jet fragmentation functions. This thesis presents the extraction of collinear and transverse momentum-dependent fragmentation functions for …


Precision Neutrino Interactions In And Beyond The Standard Model, Kaushik Borah Jan 2024

Precision Neutrino Interactions In And Beyond The Standard Model, Kaushik Borah

Theses and Dissertations--Physics and Astronomy

This dissertation investigates precision measurements of neutrino interactions within the framework of the Standard Model and explores potential extensions beyond it. Neutrinos, often referred to as ghostly particles due to their weak interactions and elusive nature, have long been a frontier in particle physics. Through detailed theoretical modeling and comparison with experimental data, this work focuses on improving our understanding of neutrino-nucleon cross-sections, nucleon form factors, and generalized neutrino interactions. The study begins with a comprehensive examination of the role of vector and axial-vector form factors in neutrino-nucleon scattering and their impact on the interpretation of neutrino oscillation data from …


Qctaas (Quality Cloud Teaching As A Service): An Immersive Framework For Teaching Cloud Computing For Cybersecurity Majors, Mahmoud K. Quweider, Liyu Zhang, Alexis Aaron De La Cruz Jan 2024

Qctaas (Quality Cloud Teaching As A Service): An Immersive Framework For Teaching Cloud Computing For Cybersecurity Majors, Mahmoud K. Quweider, Liyu Zhang, Alexis Aaron De La Cruz

Informatics and Engineering Systems Faculty Publications

Abstract Cloud Computing and Cybersecurity are at the heart of our recently created new bachelor-level degree in cybersecurity that addresses the national need for cybersecurity specialists. Cloud Computing involves many service models, including IaaS, PaaS, and SaaS, and many deployment models including Public, Private, and Hybrid clouds. Within the services and deployment models lies many concepts and practical implementations that a Cyber-analyst needs to master. We have adopted an immersive approach to teaching Cloud Computing services that introduces standard concepts based on clearly defined objectives from national certification authorities such as CompTIA Cloud+, covering all major services offered by the …


Basal Topography And Carbon Accumulation Rate Of A Rare Northern California Coastal Fen, Sarah Leidinger Jan 2024

Basal Topography And Carbon Accumulation Rate Of A Rare Northern California Coastal Fen, Sarah Leidinger

Cal Poly Humboldt theses and projects

Increasingly, the importance of peatlands as biodiversity hotpots, year-round water storage features, and significant carbon sinks are being recognized. Despite this, they are one of the most vulnerable ecosystems globally. While some peatland conservation and restoration initiatives are being developed, a greater understanding of small peatlands is needed to make management decisions. This study aims to determine the timing of peat formation, peat volume, and carbon accumulation rates of the Conspicuous Scoop Fen, a small (2.1-acre) fen near Bridgeville, California (~840 m.a.s.l.). During the summers of 2022 and 2023, I collected 39 m of peat cores at 14 sampling locations. …


Leveraging Redundancy As A Link Between Spreading Dynamics On And Of Networks, Felipe Xavier Costa Jan 2024

Leveraging Redundancy As A Link Between Spreading Dynamics On And Of Networks, Felipe Xavier Costa

Electronic Theses & Dissertations (2024 - present)

A constant quest in network science has been in the development of methods to identify the most relevant components in a dynamical system solely via the interaction structure amongst its subsystems. This information allows the development of control and intervention strategies in biochemical signaling and epidemic spreading. We highlight the relevant components in heterogeneous dynamical system by their patterns of redundancy, which can connect how dynamics affect network topology and which pathways are necessary to spreading phenomena on networks. In order to measure the redundancies in a large class of empirical systems, we develop the backbone of directed networks methodology, …


Informational Principles And Structures In Quantum Theory, Yang Yu Jan 2024

Informational Principles And Structures In Quantum Theory, Yang Yu

Electronic Theses & Dissertations (2024 - present)

This thesis examines the concept of information within the realm of quantum physics, investigating the nuanced relationship between information and physical laws as applied to quantum systems. With no consensus on a single definition of information in the physical sciences, our exploration is partitioned into two significant studies, each addressing distinct aspects of information in quantum contexts.

In the first study, we concentrate on the information that can be obtained from measurement results on identical quantum systems. The traditional approach of using Shannon entropy is limited due to its applicability primarily to discrete probability distributions. By incorporating a Bayesian update …


Fact Sheet, Yale University Office Of Institutional Research Jan 2024

Fact Sheet, Yale University Office Of Institutional Research

Fact Sheets

No abstract provided.


Extraction Of Capsaicin Using The Polyol Induced Extraction (Pie) Method, Orlando Herrera Jan 2024

Extraction Of Capsaicin Using The Polyol Induced Extraction (Pie) Method, Orlando Herrera

All Student Theses and Dissertations

Polyol-induced extraction (PIE) is an extraction technique for separating organic solvents from water, using glycerol and polyol as separating agents. Glycerol binds water releasing the organic solvent as a separate liquid phase. this thesis, investigates how the PIE process may be used to separate caffeine and capsaicin. When acetonitrile and water are used as a 1:1 solvent mixture, two immiscible phases are created upon addition of the polyol, glycerol. Initially, for purposes of training on the PIE method, the studies primarly began with the extraction of pure caffeine. Using a 1:1 mixture of acetonitrile and water, 20 m/v % glycerol, …


Effects Of Electron Beam Irradiation On Crmnv And Crmntiv High Entropy Alloys: Nano-Mechanical, Structural, And Thermodynamic Perspectives, N. A. Sultana, Y. S. Mohammed, S. J. Pendleton, J. Vennekate, G. Ciovati, X. Li, H. Baumgart, A. A. Elmustafa Jan 2024

Effects Of Electron Beam Irradiation On Crmnv And Crmntiv High Entropy Alloys: Nano-Mechanical, Structural, And Thermodynamic Perspectives, N. A. Sultana, Y. S. Mohammed, S. J. Pendleton, J. Vennekate, G. Ciovati, X. Li, H. Baumgart, A. A. Elmustafa

Mechanical & Aerospace Engineering Faculty Publications

Beam exit windows are crucial components of any particle accelerator as they provide an interface between the beamline vacuum and target material at atmospheric media. For high beam power machines, special materials and designs are required to withstand high radiation and mechanical loads, while minimizing energy loss during transition and maximizing window lifetime. This research investigates the impact of electron beam exposure to bulk CrMnV and CrMnTiV high entropy alloys (HEAs) with the primary goal of identifying suitable candidate materials for the design of robust and durable exit window settings. The selection criteria include intrinsic characteristics, power dissipation, and mechanical …


On The Links Between Sea Level And Temperature Variations In The Chesapeake Bay And The Atlantic Meridional Overturning Circulation (Amoc), Tal Ezer, Teresa Updyke Jan 2024

On The Links Between Sea Level And Temperature Variations In The Chesapeake Bay And The Atlantic Meridional Overturning Circulation (Amoc), Tal Ezer, Teresa Updyke

CCPO Publications

Recent studies found that on long time scales there are often unexplained opposite trends in sea level variability between the upper and lower Chesapeake Bay (CB). Therefore, daily sea level and temperature records were analyzed in two locations, Norfolk in the southern CB and Baltimore in the northern CB; surface currents from Coastal Ocean Dynamics Application Radar (CODAR) near the mouth of CB were also analyzed to examine connections between the CB and the Atlantic Ocean. The observations in the bay were compared with daily Atlantic Meridional Overturning Circulation (AMOC) observations during 2005–2021. Empirical Mode Decomposition (EMD) analysis was used …


Evidence For Large-Scale Climate Forcing Of Dense Shelf Water Variability In The Ross Sea, Zhaoru Zhang, Chuan Xie, Pasquale Castagno, Matthew H. England, Xiaoqiao Wang, Michael S. Dinniman, Alessandro Silvano, Chuning Wang, Lei Zhou, Xichen Li, Meng Zhou, Giorgio Budillon Jan 2024

Evidence For Large-Scale Climate Forcing Of Dense Shelf Water Variability In The Ross Sea, Zhaoru Zhang, Chuan Xie, Pasquale Castagno, Matthew H. England, Xiaoqiao Wang, Michael S. Dinniman, Alessandro Silvano, Chuning Wang, Lei Zhou, Xichen Li, Meng Zhou, Giorgio Budillon

CCPO Publications

Antarctic Bottom Water (AABW), which supplies the lower limb of the thermohaline circulation, originates from dense shelf water (DSW) forming in Antarctic polynyas. Here, combining a long mooring record of DSW measurements with numerical simulations and satellite data, we show that significant correlation exists between interannual variability of DSW production in the Ross Sea polynyas, where DSW contributes between 20-40% of the global AABW production, and the Southern Annular Mode (SAM). The correlation is largest when the Amundsen Sea Low (ASL) is weakened and shifted east of the Ross Sea. During positive SAM phases, enhanced offshore winds and lower air …


Western Boundary Current-Subtropical Continental Shelf Interactions, William B. Savidge, Dana K. Savidge, Frederico Brandini, Adam T. Greer, Eileen E. Hofmann, Moninya Roughan, Iison De Silvera, Iain M. Suthers Jan 2024

Western Boundary Current-Subtropical Continental Shelf Interactions, William B. Savidge, Dana K. Savidge, Frederico Brandini, Adam T. Greer, Eileen E. Hofmann, Moninya Roughan, Iison De Silvera, Iain M. Suthers

CCPO Publications

Western boundary currents (WBCs) adjacent to subtropical continental shelves (STCSs; between ~25° and 35° latitude; Figure 1) transport heat, nutrients, and biota poleward along the western margins of major ocean basins, interacting with the continental margins and influencing their physics and biology. Eddies and meanders along the shelf edge upwell deep, nutrient-laden water that can be advected onto the adjacent shelves with a corresponding export of particle-rich shelf water (e.g., Lee et al., 1991; Kimura et al., 1997; Campos et al., 2000; Roughan and Middleton, 2002, 2004; Lutjeharms, 2006; Savidge and Savidge, 2014). Despite their similarities, the various STCS regions …


Building A Coordinated Framework For Research And Monitoring In Large-Scale International Marine Protected Areas: The Ross Sea Region As A Model System, Cassandra Brooks, Sharon Stammerjohn, Grant Ballard, Alice K. Duvivier, Eileen Hofmann, Michelle Larue, Cara Nissen, Alexander J. Orona, B. Jack Pan, Annie E. Schmidt, Nathan Walker, George M. Watters, John Weller Jan 2024

Building A Coordinated Framework For Research And Monitoring In Large-Scale International Marine Protected Areas: The Ross Sea Region As A Model System, Cassandra Brooks, Sharon Stammerjohn, Grant Ballard, Alice K. Duvivier, Eileen Hofmann, Michelle Larue, Cara Nissen, Alexander J. Orona, B. Jack Pan, Annie E. Schmidt, Nathan Walker, George M. Watters, John Weller

CCPO Publications

To fulfill their conservation potential and provide safeguards for biodiversity, marine protected areas (MPAs) need coordinated research and monitoring for informed management through effective evaluation of ecosystem dynamics. However, coordination is challenging, often due to knowledge gaps caused by inadequate access to data and resources, compounded by insufficient communication between scientists and managers. We propose to use the world's largest MPA in the Ross Sea, Antarctica as a model system to create a comprehensive framework for an interdisciplinary network supporting research and monitoring that could be implemented in other remote large-scale international MPAs. Our proposed framework has three key components: …


Delayed Coastal Inundations Caused By Ocean Dynamics Post-Hurricane Matthew, Kyungmin Park, Emanuele Di Lorenzo, Yinglong J. Zhang, Tal Ezer, Fei Yi Jan 2024

Delayed Coastal Inundations Caused By Ocean Dynamics Post-Hurricane Matthew, Kyungmin Park, Emanuele Di Lorenzo, Yinglong J. Zhang, Tal Ezer, Fei Yi

CCPO Publications

Post Hurricane Abnormal Water Level (PHAWL) poses a persistent inundation threat to coastal communities, yet unresolved knowledge gaps exist regarding its spatiotemporal impacts and causal mechanisms. Using a high-resolution coastal model with a set of observations, we find that the PHAWLs are up to 50 cm higher than the normal water levels for several weeks and cause delayed inundations around residential areas of the U.S. Southeast Coast (USSC). Numerical experiments reveal that while atmospheric forcing modulates the coastal PHAWLs, ocean dynamics primarily driven by the Gulf Stream control the mean component and duration of the shelf-scale PHAWLs. Because of the …


Divergent Responses Of Nitrogen-Species Loadings To Future Climate Change In The Chesapeake Bay Watershed, Zihao Bian, Shufen Pan, Raymond G. Najjar, Marjorie A.M. Friedrichs, Eileen E. Hofmann, Maria Herrmann, Kyle E. Hinson, Pierre St.-Laurent, Hanqin Tian Jan 2024

Divergent Responses Of Nitrogen-Species Loadings To Future Climate Change In The Chesapeake Bay Watershed, Zihao Bian, Shufen Pan, Raymond G. Najjar, Marjorie A.M. Friedrichs, Eileen E. Hofmann, Maria Herrmann, Kyle E. Hinson, Pierre St.-Laurent, Hanqin Tian

CCPO Publications

Study region: Chesapeake Bay Watershed

Study focus: Climate plays a critical role in regulating N loading from terrestrial ecosystems to coastal waters and further affecting the health and functioning of coastal ecosystems. However, the sensitivities of riverine exports of different N species to climate change have rarely been investigated. This study examines the response of riverine exports of ammonia (NH₄+), nitrate (NO₃-), dissolved organic nitrogen (DON), and particulate organic nitrogen (PON) to future changes in precipitation and temperature. A suite of climate forcings was used to drive a processbased terrestrial-aquatic model, DLEM (Dynamic Land Ecosystem Model), …


Methods That Support The Validation Of Agent-Based Models: An Overview And Discussion, Andrew Collins, Matthew Koehler, Christopher Lynch Jan 2024

Methods That Support The Validation Of Agent-Based Models: An Overview And Discussion, Andrew Collins, Matthew Koehler, Christopher Lynch

Engineering Management & Systems Engineering Faculty Publications

Validation is the process of determining if a model adequately represents the system under study for the model’s intended purpose. Validation is a critical component in building the credibility of a simulation model with its end-users. Effectively conducting validation can be a daunting task for both novice and experienced simulation developers. Further compounding the difficult task of conducting validation is that there is no universally accepted approach for assessing a simulation. These challenges are particularly relevant to the paradigm of Agent-Based Modeling and Simulation (ABMS) because of the complexity found in these models’ mechanisms and in the real-world situations they …


Teaching Analytics Online: A Self-Study Of Professional Practice, Andrew J. Collins, Brandon Butler, James F. Leathrum Jr., Christopher J. Lynch Jan 2024

Teaching Analytics Online: A Self-Study Of Professional Practice, Andrew J. Collins, Brandon Butler, James F. Leathrum Jr., Christopher J. Lynch

Engineering Management & Systems Engineering Faculty Publications

As the COVID-19 pandemic caused severe disruption to education enterprises throughout the world, the main response by educational institutions was to move to online learning environments. The purpose of this study was to understand better how instructors could improve online learning for a professional-level week-long short course in a highly technical area (data analytics), which had, pre-COVID, been a hands-on computer, laboratory-based learning experience. The authors used self-study of professional practice to elicit and understand the major issues and concerns of the transition to an online learning environment. Under the guidance of a colleague in teacher education, three course instructors …


Heterogeneity Of Nitrogen Fixation In The Mesopelagic Zone Of The South China Sea, Siqi Wu, Xianhui Sean Wan, Moge Du, Xirong Chen, Corday R. Selden, Mar Benavides, Sophie Bonnet, Carolin R. Löscher, M. Robert Hamersley, Margaret R. Mulholland, Xiuli Yan, Shuh-Ji Kao Jan 2024

Heterogeneity Of Nitrogen Fixation In The Mesopelagic Zone Of The South China Sea, Siqi Wu, Xianhui Sean Wan, Moge Du, Xirong Chen, Corday R. Selden, Mar Benavides, Sophie Bonnet, Carolin R. Löscher, M. Robert Hamersley, Margaret R. Mulholland, Xiuli Yan, Shuh-Ji Kao

OES Faculty Publications

Biological dinitrogen (N₂) fixation, the energetically expensive conversion of N₂ gas to ammonia, plays an essential role in balancing the nitrogen budget in the ocean. Accumulating studies show detectable N₂ fixation rates below the euphotic zone in various marine systems, revealing new insights of marine N₂ fixation. However, the reported rates are highly variable and frequently fall close to detection limits, raising the question of the ubiquity and significance of N₂ fixation in the global dark ocean. Using highly sensitive isotopic labeling incubation including a set of control incubations, we confirm the occurrence of mesopelagic N₂ fixation in the South …