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Articles 1 - 30 of 6056

Full-Text Articles in Physical Sciences and Mathematics

Generalized Periodicity And Applications To Logistic Growth, Martin Bohner, Jaqueline Mesquita, Sabrina Streipert Sep 2024

Generalized Periodicity And Applications To Logistic Growth, Martin Bohner, Jaqueline Mesquita, Sabrina Streipert

Mathematics and Statistics Faculty Research & Creative Works

Classically, a continuous function f:R→R is periodic if there exists an ω>0 such that f(t+ω)=f(t) for all t∈R. The extension of this precise definition to functions f:Z→R is straightforward. However, in the so-called quantum case, where f:qN0→R (q>1), or more general isolated time scales, a different definition of periodicity is needed. A recently introduced definition of periodicity for such general isolated time scales, including the quantum calculus, not only addressed this gap but also inspired this work. We now return to the continuous case and present the concept of ν-periodicity that connects these different formulations of periodicity for …

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The Cubic-Quintic Nonlinear Schrödinger Equation With Inverse-Square Potential, Alex H. Ardila, Jason Murphy Sep 2024

The Cubic-Quintic Nonlinear Schrödinger Equation With Inverse-Square Potential, Alex H. Ardila, Jason Murphy

Mathematics and Statistics Faculty Research & Creative Works

We consider the nonlinear Schrödinger equation in three space dimensions with a focusing cubic nonlinearity and defocusing quintic nonlinearity and in the presence of an external inverse-square potential. We establish scattering in the region of the mass-energy plane where the virial functional is guaranteed to be positive. Our result parallels the scattering result of [11] in the setting of the standard cubic-quintic NLS.

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Instantons In Φ4 Theories: Transseries, Virial Theorems, And Numerical Aspects, Ludovico T. Giorgini, Ulrich D. Jentschura, Enrico M. Malatesta, Tommaso Rizzo, Jean Zinn-Justin Aug 2024

Instantons In Φ4 Theories: Transseries, Virial Theorems, And Numerical Aspects, Ludovico T. Giorgini, Ulrich D. Jentschura, Enrico M. Malatesta, Tommaso Rizzo, Jean Zinn-Justin

Physics Faculty Research & Creative Works

We discuss numerical aspects of instantons in two- and three-dimensional φ4 theories with an internal O(N) symmetry group, the so-called N-vector model. By combining asymptotic transseries expansions for large arguments with convergence acceleration techniques, we obtain high-precision values for certain integrals of the instanton that naturally occur in loop corrections around instanton configurations. Knowledge of these numerical properties is necessary in order to evaluate corrections to the large-order factorial growth of perturbation theory in φ4 theories. The results contribute to the understanding of the mathematical structures underlying the instanton configurations.

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Perturbative Versus Non-Perturbative Renormalization, S. Hariharakrishnan, Ulrich D. Jentschura, I. G. Marian, K. Szabo, I. Nandori Aug 2024

Perturbative Versus Non-Perturbative Renormalization, S. Hariharakrishnan, Ulrich D. Jentschura, I. G. Marian, K. Szabo, I. Nandori

Physics Faculty Research & Creative Works

Approximated functional renormalization group (FRG) equations lead to regulator-dependent β-functions, in analogy to the scheme-dependence of the perturbative renormalization group (pRG) approach. A scheme transformation redefines the couplings to relate the β-functions of the FRG method with an arbitrary regulator function to the pRG ones obtained in a given scheme. Here, we consider a periodic sine-Gordon scalar field theory in d = 2 dimensions and show that the relation of the FRG and pRG approaches is intricate. Although both the FRG and the pRG methods are known to be sufficient to obtain the critical frequency β c 2 = 8 …

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Doubly Differential Cross Sections For Ionization In Proton Collisions With Atomic Hydrogen: Energy And Angular Distribution Of Emitted Electrons, C. T. Plowman, K. H. Spicer, N. W. Antonio, M. S. Schöffler, Michael Schulz, I. Bray, A. S. Kadyrov Aug 2024

Doubly Differential Cross Sections For Ionization In Proton Collisions With Atomic Hydrogen: Energy And Angular Distribution Of Emitted Electrons, C. T. Plowman, K. H. Spicer, N. W. Antonio, M. S. Schöffler, Michael Schulz, I. Bray, A. S. Kadyrov

Physics Faculty Research & Creative Works

We use the two-center wave-packet convergent close-coupling approach to ion-atom collisions to calculate the energy and angular distribution of electrons emitted in proton collisions with atomic hydrogen. Results are provided across a wide range of intermediate energies where many competing reaction channels make calculations challenging. The present data consistently agree with the available experimental measurements and improve upon previously available results based on perturbative and classical methods. Furthermore, we extend the range of electron angles and energies over which theoretical data are available for the doubly differential cross section for ionization. This provides strong evidence that at the level of …

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Dispersive Shock Waves In A One-Dimensional Droplet-Bearing Environment, Sathyanarayanan Chandramouli, S. I. Mistakidis, G. C. Katsimiga, P. G. Kevrekidis Aug 2024

Dispersive Shock Waves In A One-Dimensional Droplet-Bearing Environment, Sathyanarayanan Chandramouli, S. I. Mistakidis, G. C. Katsimiga, P. G. Kevrekidis

Physics Faculty Research & Creative Works

We demonstrate the controllable generation of distinct types of dispersive shock waves emerging in a quantum droplet bearing environment with the aid of steplike initial conditions. Dispersive regularization of the ensuing hydrodynamic singularities occurs due to the competition between mean-field repulsion and attractive quantum fluctuations. This interplay delineates the dominance of defocusing (hyperbolic) and focusing (elliptic) hydrodynamic phenomena being designated by the real and the imaginary speed of sound, respectively. Specifically, the symmetries of the extended Gross-Pitaevskii model led to a three-parameter family, encompassing two densities and a relative velocity of the underlying Riemann problem utilized herein. Surprisingly, dispersive shock …

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Mesenchymal Stem Cells In Autoimmune Disease: A Systematic Review And Meta-Analysis Of Pre-Clinical Studies, Hailey N. Swain, Parker D. Boyce, Bradley A. Bromet, Kaiden Barozinksy, Lacy Hance, Dakota Shields, Gayla R. Olbricht, Julie A. Semon Aug 2024

Mesenchymal Stem Cells In Autoimmune Disease: A Systematic Review And Meta-Analysis Of Pre-Clinical Studies, Hailey N. Swain, Parker D. Boyce, Bradley A. Bromet, Kaiden Barozinksy, Lacy Hance, Dakota Shields, Gayla R. Olbricht, Julie A. Semon

Mathematics and Statistics Faculty Research & Creative Works

Mesenchymal Stem Cells (MSCs) Are of Interest in the Clinic Because of their Immunomodulation Capabilities, Capacity to Act Upstream of Inflammation, and Ability to Sense Metabolic Environments. in Standard Physiologic Conditions, They Play a Role in Maintaining the Homeostasis of Tissues and Organs; However, there is Evidence that They Can Contribute to Some Autoimmune Diseases. Gaining a Deeper Understanding of the Factors that Transition MSCs from their Physiological Function to a Pathological Role in their Native Environment, and Elucidating Mechanisms that Reduce their Therapeutic Relevance in Regenerative Medicine, is Essential. We Conducted a Systematic Review and Meta-Analysis of Human MSCs …

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Particle-Imbalanced Weakly Interacting Quantum Droplets In One Dimension, I. A. Englezos, P. Schmelcher, S. I. Mistakidis Aug 2024

Particle-Imbalanced Weakly Interacting Quantum Droplets In One Dimension, I. A. Englezos, P. Schmelcher, S. I. Mistakidis

Physics Faculty Research & Creative Works

We explore the formation of one-dimensional two-component quantum droplets with intercomponent particle imbalance using an ab initio many-body method. It is shown that for moderate particle imbalance each component maintains its droplet flat-top or Gaussian-type character depending on the intercomponent attraction. Importantly, large particle imbalance leads to a flat-top shape of the majority component with the minority exhibiting spatially localized configurations. The latter imprint modulations on the majority component which become more pronounced for increasing interspecies attraction. The same holds for larger mass or increasing repulsion of the minority species. Such structural transitions are also evident in the underlying two-body …

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Novel Emergent Phases In A Two-Dimensional Superconductor, Simrandeep Kaur, Hemanta Kumar Kundu, Sumit Kumar, Anjana Dogra, Rajesh Narayanan, Thomas Vojta, Aveek Bid Aug 2024

Novel Emergent Phases In A Two-Dimensional Superconductor, Simrandeep Kaur, Hemanta Kumar Kundu, Sumit Kumar, Anjana Dogra, Rajesh Narayanan, Thomas Vojta, Aveek Bid

Physics Faculty Research & Creative Works

In this letter, we report our observation of an extraordinarily rich phase diagram of a LaScO3/SrTiO3 heterostructure. Close to the superconducting transition temperature, the system hosts a superconducting critical point of the Infinite-randomness type characterized by an effective dynamical exponent ν z that diverges logarithmically. At lower temperatures, we find the emergence of a magnetic field-tuned metallic phase that co-exists with a quantum Griffiths phase (QGP). Our study reveals a previously unobserved phenomenon in 2D superconductors—an unanticipated suppression of the QGP below a crossover temperature in this system. This concealment is accompanied by the destruction of the …

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Dispersive Shock Waves In A One-Dimensional Droplet-Bearing Environment, Sathyanarayanan Chandramouli, S. I. Mistakidis, G. C. Katsimiga, P. G. Kevrekidis Aug 2024

Dispersive Shock Waves In A One-Dimensional Droplet-Bearing Environment, Sathyanarayanan Chandramouli, S. I. Mistakidis, G. C. Katsimiga, P. G. Kevrekidis

Physics Faculty Research & Creative Works

We demonstrate the controllable generation of distinct types of dispersive shock waves emerging in a quantum droplet bearing environment with the aid of steplike initial conditions. Dispersive regularization of the ensuing hydrodynamic singularities occurs due to the competition between mean-field repulsion and attractive quantum fluctuations. This interplay delineates the dominance of defocusing (hyperbolic) and focusing (elliptic) hydrodynamic phenomena being designated by the real and the imaginary speed of sound, respectively. Specifically, the symmetries of the extended Gross-Pitaevskii model led to a three-parameter family, encompassing two densities and a relative velocity of the underlying Riemann problem utilized herein. Surprisingly, dispersive shock …

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A Human-Centered Power Conservation Framework Based On Reverse Auction Theory And Machine Learning, Enrico Casella, Simone Silvestri, Denise A. Baker, Sajal K. Das Jul 2024

A Human-Centered Power Conservation Framework Based On Reverse Auction Theory And Machine Learning, Enrico Casella, Simone Silvestri, Denise A. Baker, Sajal K. Das

Computer Science Faculty Research & Creative Works

Extreme outside temperatures resulting from heat waves, winter storms, and similar weather-related events trigger the Heating Ventilation and Air Conditioning (HVAC) systems, resulting in challenging, and potentially catastrophic, peak loads. As a consequence, such extreme outside temperatures put a strain on power grids and may thus lead to blackouts. To avoid the financial and personal repercussions of peak loads, demand response and power conservation represent promising solutions. Despite numerous efforts, it has been shown that the current state-of-the-art fails to consider (1) the complexity of human behavior when interacting with power conservation systems and (2) realistic home-level power dynamics. As …

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Kinetic Characterization And Identification Of Key Active Site Residues Of The L-Aspartate N-Hydroxylase, Cree, Sydney B. Johnson, Hannah Valentino, Pablo Sobrado Jul 2024

Kinetic Characterization And Identification Of Key Active Site Residues Of The L-Aspartate N-Hydroxylase, Cree, Sydney B. Johnson, Hannah Valentino, Pablo Sobrado

Chemistry Faculty Research & Creative Works

CreE is a flavin-dependent monooxygenase (FMO) that catalyzes three sequential nitrogen oxidation reactions of L-aspartate to produce nitrosuccinate, contributing to the biosynthesis of the antimicrobial and antiproliferative nautral product, cremeomycin. This compound contains a highly reactive diazo functional group for which the reaction of CreE is essential to its formation. Nitro and diazo functional groups can serve as potent electrophiles, important in some challenging nucleophilic addition reactions. Formation of these reactive groups positions CreE as a promising candidate for biomedical and synthetic applications. Here, we present the catalytic mechanism of CreE and the identification of active site residues critical to …

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Kinetic Characterization And Identification Of Key Active Site Residues Of The L-Aspartate N-Hydroxylase, Cree, Sydney B. Johnson, Hannah Valentino, Pablo Sobrado Jul 2024

Kinetic Characterization And Identification Of Key Active Site Residues Of The L-Aspartate N-Hydroxylase, Cree, Sydney B. Johnson, Hannah Valentino, Pablo Sobrado

Chemistry Faculty Research & Creative Works

CreE is a flavin-dependent monooxygenase (FMO) that catalyzes three sequential nitrogen oxidation reactions of L-aspartate to produce nitrosuccinate, contributing to the biosynthesis of the antimicrobial and antiproliferative natural product, cremeomycin. This compound contains a highly reactive diazo functional group for which the reaction of CreE is essential to its formation. Nitro and diazo functional groups can serve as potent electrophiles, important in some challenging nucleophilic addition reactions. Formation of these reactive groups positions CreE as a promising candidate for biomedical and synthetic applications. Here, we present the catalytic mechanism of CreE and the identification of active site residues critical to …

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Doing Personal Laps: Llm-Augmented Dialogue Construction For Personalized Multi-Session Conversational Search, Hideaki Joko, Shubham Chatterjee, Andrew Ramsay, Arjen P. De Vries, Jeff Dalton, Faegheh Hasibi Jul 2024

Doing Personal Laps: Llm-Augmented Dialogue Construction For Personalized Multi-Session Conversational Search, Hideaki Joko, Shubham Chatterjee, Andrew Ramsay, Arjen P. De Vries, Jeff Dalton, Faegheh Hasibi

Computer Science Faculty Research & Creative Works

The future of conversational agents will provide users with personalized information responses. However, a significant challenge in developing models is the lack of large-scale dialogue datasets that span multiple sessions and reflect real-world user preferences. Previous approaches rely on experts in a wizard-of-oz setup that is difficult to scale, particularly for personalized tasks. Our method, LAPS, addresses this by using large language models (LLMs) to guide a single human worker in generating personalized dialogues. This method has proven to speed up the creation process and improve quality. LAPS can collect large-scale, human-written, multi-session, and multi-domain conversations, including extracting user preferences. …

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Trec Ikat 2023: A Test Collection For Evaluating Conversational And Interactive Knowledge Assistants, Mohammad Aliannejadi, Zahra Abbasiantaeb, Shubham Chatterjee, Jeffrey Dalton, Leif Azzopardi Jul 2024

Trec Ikat 2023: A Test Collection For Evaluating Conversational And Interactive Knowledge Assistants, Mohammad Aliannejadi, Zahra Abbasiantaeb, Shubham Chatterjee, Jeffrey Dalton, Leif Azzopardi

Computer Science Faculty Research & Creative Works

Conversational information seeking has evolved rapidly in the last few years with the development of Large Language Models (LLMs), providing the basis for interpreting and responding in a naturalistic manner to user requests. The extended TREC Interactive Knowledge Assistance Track (iKAT) collection aims to enable researchers to test and evaluate their Conversational Search Agent (CSA). The collection contains a set of 36 personalized dialogues over 20 different topics each coupled with a Personal Text Knowledge Base (PTKB) that defines the bespoke user personas. A total of 344 turns with approximately 26,000 passages are provided as assessments on relevance, as well …

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Critical Behavior And Collective Modes At The Superfluid Transition In Amorphous Systems, Pulloor Kuttanikkad Vishnu, Martin Puschmann, Rajesh Narayanan, Thomas Vojta Jul 2024

Critical Behavior And Collective Modes At The Superfluid Transition In Amorphous Systems, Pulloor Kuttanikkad Vishnu, Martin Puschmann, Rajesh Narayanan, Thomas Vojta

Physics Faculty Research & Creative Works

We investigate the critical behavior and the dynamics of the amplitude (Higgs) mode close to the superfluid-insulator quantum phase transition in an amorphous system (i.e., a system subject to topological randomness). In particular, we map the two-dimensional Bose-Hubbard Hamiltonian defined on a random Voronoi-Delaunay lattice onto a (2+1)-dimensional layered classical XY model with correlated topological disorder. We study the resulting model by laying recourse to classical Monte Carlo simulations. We specifically focus on the scalar susceptibility of the order parameter to study the dynamics of the amplitude mode. To do so, we harness the maximum entropy method to perform the …

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Eighth-Order Foldy-Wouthuysen Transformation, Ulrich D. Jentschura Jul 2024

Eighth-Order Foldy-Wouthuysen Transformation, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

The calculation of higher-order binding corrections to bound systems is a fundamental problem of theoretical physics. For any nonrelativistic expansion, one needs the Foldy-Wouthuysen transformation, which disentangles the particle and the antiparticle degrees of freedom. This transformation is carried out here to eighth order in the momenta or to eighth order in the momentum operators, which is equivalent to the eighth order of the fine-structure constant. Matrix elements of the eighth-order terms are evaluated for F5/2 and F7/2 states in hydrogenlike ions and compared with the Dirac-Coulomb energy levels.

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Tunneling Dynamics Of 164dy Supersolids And Droplets, S. I. Mistakidis, K. Mukherjee, S. M. Reimann, H. R. Sadeghpour Jul 2024

Tunneling Dynamics Of 164dy Supersolids And Droplets, S. I. Mistakidis, K. Mukherjee, S. M. Reimann, H. R. Sadeghpour

Physics Faculty Research & Creative Works

The tunneling dynamics of a magnetic Dy164 quantum gas in an elongated or pancake skewed double-well trap is investigated with a time-dependent extended Gross-Pitaevskii approach. Upon lifting the energy offset, different tunneling regimes can be identified. In the elongated trap and for sufficiently large offset, the different configurations exhibit collective macroscopic tunneling. For smaller offset, partial reflection from and transmission through the barrier lead to density accumulation in both wells, and eventually to tunneling locking. One can also reach the macroscopic self-trapping regime for increasing relative dipolar interaction strength, while tunneling vanishes for large barrier heights. A richer dynamical behavior …

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Magnetic Properties Of Diluted Hexaferrites, Logan Sowadski, Sean Anderson, Cameron Lerch, Julia E. Medvedeva, Thomas Vojta Jul 2024

Magnetic Properties Of Diluted Hexaferrites, Logan Sowadski, Sean Anderson, Cameron Lerch, Julia E. Medvedeva, Thomas Vojta

Physics Faculty Research & Creative Works

We revisit the magnetic properties of the hexagonal ferrite PbFe12-xGaxO19. Recent experiments have reported puzzling dependences of the ordering temperature and the saturation magnetization on the Ga concentration x. To explain these observations, we perform large-scale Monte Carlo simulations, focusing on the effects of an unequal distribution of the Ga impurities over the five distinct Fe sublattices. Ab initio density-functional calculations predict that the Ga ions preferably occupy the 12k sublattice and (to a lesser extent) the 2a sublattice. We incorporate this insight into a nonuniform model of the Ga distribution. Monte Carlo simulations …

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Reinforcement Learning Based Proactive Entanglement Swapping For Quantum Networks, Tasdiqul Islam, Md Arifuzzaman, Engin Arslan Jul 2024

Reinforcement Learning Based Proactive Entanglement Swapping For Quantum Networks, Tasdiqul Islam, Md Arifuzzaman, Engin Arslan

Computer Science Faculty Research & Creative Works

Entanglement generation and swapping is a difficult process due to probabilistic nature of quantum mechanics. To overcome this issue, existing quantum routing algorithms try to create entanglement on multiple paths between source and destination. Although it is possible to save entangled qubits on unused links using quantum memories, the quantum routing algorithms discard them and try creating new entanglement in each time slot. In this work, we leverage the longevity of entanglement and introduce two enhancements to improve the performance of existing routing algorithms: (i) The generation and caching of entanglements across multiple time slots, and (ii) the proactively executing …

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Effective Data Sharing In An Edge-Cloud Model: Security Challenges And Solutions, Arijit Karati, Sajal K. Das Jul 2024

Effective Data Sharing In An Edge-Cloud Model: Security Challenges And Solutions, Arijit Karati, Sajal K. Das

Computer Science Faculty Research & Creative Works

The proposed protocol offers privacy-preserving authentication across several cloud platforms, flexible key management for consumer data protection, and effective user revocation. Performance evaluation demonstrates that the proposed framework supports low latency, safe unified remote access, and data privacy in the contemporary edge-enabled environment.

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Predicting Iot Distributed Ledger Fraud Transactions With A Lightweight Gan Network, Charles Rawlins, Jagannathan Sarangapani Jul 2024

Predicting Iot Distributed Ledger Fraud Transactions With A Lightweight Gan Network, Charles Rawlins, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

Decision-making and consensus in traditional blockchain protocols is formulated as a repeated Bernoulli trial that solves a computationally intense lottery puzzle, called Proof-of-Work (PoW) in Bitcoin. This approach has shown robustness through practice but does not scale with increasing network size and generation of new transactions. Resource constrained Internet of Things (IoT) networks are incompatible with full computation of schemes like Bitcoin's PoW. Our effort proposes a first step towards an alternative consensus using machine learning-based decision-making with prediction of fraud transactions to alleviate need for intense computation. To improve base approval probabilities for fraud detection in an ideal security …

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Harnessing Redox Polymer Dynamics For Enhanced Glucose-Oxygen Coupling In Dual Biosensing And Therapeutic Applications, Wassim El Housseini, Egor Baiarashov, Rokas Gerulskis, Adam Milam, Shelley D. Minteer Jun 2024

Harnessing Redox Polymer Dynamics For Enhanced Glucose-Oxygen Coupling In Dual Biosensing And Therapeutic Applications, Wassim El Housseini, Egor Baiarashov, Rokas Gerulskis, Adam Milam, Shelley D. Minteer

Chemistry Faculty Research & Creative Works

The burgeoning field of continuous glucose monitoring (CGM) for diabetes management faces significant challenges, particularly in achieving precise and stable biosensor performance under changing environmental conditions such as varying glucose concentrations and O2 levels. To address this, we present a novel biosensor based on the electroless coupling of glucose oxidation catalyzed by flavin-dependent glucose dehydrogenase (FAD-GDH) and O2 reduction catalyzed by bilirubin oxidase (BOD) via a redox polymer, dimethylferrocene-modified linear poly(ethylenimine), FcMe2-LPEI. Initial cyclic voltammetry tests confirm the colocalization of both enzymatic reactions within the potential range of the polymer, indicating an effective electron shuttle mechanism. …

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Thermal Stability Of Amorphous Metal Oxides: The Interplay Of Secondary Cations, Degree Of Substitution, And Local Structure, Li Zeng, D. Bruce Buchholz, Denis T. Keane, Tobin J. Marks, Julia E. Medvedeva, Michael J. Bedzyk Jun 2024

Thermal Stability Of Amorphous Metal Oxides: The Interplay Of Secondary Cations, Degree Of Substitution, And Local Structure, Li Zeng, D. Bruce Buchholz, Denis T. Keane, Tobin J. Marks, Julia E. Medvedeva, Michael J. Bedzyk

Physics Faculty Research & Creative Works

Indium-based amorphous metal oxides (AMOs) are important materials that enable a wide range of electronic and optoelectronic applications. The metal cations that substitute for In are known to effectively tune the material properties as well as to retain the desirable amorphous state when subjected to high operating temperatures. While much attention focuses on property tuning, there is less focus on those fundamental factors that enhance thermal stability. Hence, in this paper, we employ in situ X-ray scattering and ab initio molecular dynamics (MD) to systematically study the effects of secondary cations on the crystallization process. A series of amorphous (In …

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Interpenetrated Lattices Of Quaternary Chalcogenides Displaying Magnetic Frustration, High Na-Ion Conductivity, And Cation Redox In Na-Ion Batteries, Santhoshkumar Sundaramoorthy, Srikanth Balijapelly, Sudip Mohapatra, Sutapa Bhattacharya, Kartik Ghosh, Amitava Choudhury Jun 2024

Interpenetrated Lattices Of Quaternary Chalcogenides Displaying Magnetic Frustration, High Na-Ion Conductivity, And Cation Redox In Na-Ion Batteries, Santhoshkumar Sundaramoorthy, Srikanth Balijapelly, Sudip Mohapatra, Sutapa Bhattacharya, Kartik Ghosh, Amitava Choudhury

Chemistry Faculty Research & Creative Works

A series of quaternary selenides, NaxMGaSe4 (M = Mn, Fe, and mixed Zn/Fe), have been synthesized for the first time employing a high-temperature solid-state synthesis route through stochiometric or polychalcogenide flux reactions. Along with the selenides, a previously reported sulfide analogue, NaxFeGaS4, is also revisited with new findings. These compounds form an interpenetrated structure made up of a supertetrahedral unit. The electrochemical evaluations exhibit a reversible (de)intercalation of ∼0.6 and ∼0.45 Na-ions, respectively, from Na2.87FeGaS4 (1a) and Na2.5FeGaSe4 (2) involving Fe2+/Fe3+ redox when cycled between 1.5 and 2.5 …

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Mechanism Of Nitrone Formation By A Flavin-Dependent Monooxygenase, Sydney B. Johnson, Hao Li, Hannah Valentino, Pablo Sobrado Jun 2024

Mechanism Of Nitrone Formation By A Flavin-Dependent Monooxygenase, Sydney B. Johnson, Hao Li, Hannah Valentino, Pablo Sobrado

Chemistry Faculty Research & Creative Works

OxaD is a flavin-dependent monooxygenase (FMO) responsible for catalyzing the oxidation of an indole nitrogen atom, resulting in the formation of a nitrone. Nitrones serve as versatile intermediates in complex syntheses, including challenging reactions like cycloadditions. Traditional organic synthesis methods often yield limited results and involve environmentally harmful chemicals. Therefore, the enzymatic synthesis of nitrone-containing compounds holds promise for more sustainable industrial processes. In this study, we explored the catalytic mechanism of OxaD using a combination of steady-state and rapid-reaction kinetics, site-directed mutagenesis, spectroscopy, and structural modeling. Our investigations showed that OxaD catalyzes two oxidations of the indole nitrogen of …

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Ruling Out A Saddle-Point Mechanism Of Ionization In Intermediate-Energy Ion-Atom Collisions, K. H. Spicer, C. T. Plowman, N. W. Antonio, M. S. Schöffler, Michael Schulz, A. S. Kadyrov Jun 2024

Ruling Out A Saddle-Point Mechanism Of Ionization In Intermediate-Energy Ion-Atom Collisions, K. H. Spicer, C. T. Plowman, N. W. Antonio, M. S. Schöffler, Michael Schulz, A. S. Kadyrov

Physics Faculty Research & Creative Works

Is there a saddle-point mechanism for ionization in intermediate-energy ion-atom collisions Since Olson [Phys. Rev. A 33, 4397 (1986)0556-279110.1103/PhysRevA.33.4397] proposed the idea that the electrons stranded in the potential saddle between the two Coulomb centers dominate the ejected-electron spectra, multiple experimental and theoretical attempts have been made to answer this question. However, the topic has remained controversial. Here we provide a theoretical analysis of this question which can contribute significantly to a definitive answer, at least for intermediate and large projectile energies. To this end we calculate the energy and angular distribution of electrons emitted in proton-helium collisions. We use …

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Prescribed-Time Nash Equilibrium Seeking For Pursuit-Evasion Game, Lei Xue, Jianfeng Ye, Yongbao Wu, Jian Liu, D. C. Wunsch Jun 2024

Prescribed-Time Nash Equilibrium Seeking For Pursuit-Evasion Game, Lei Xue, Jianfeng Ye, Yongbao Wu, Jian Liu, D. C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

Dear Editor, this letter is concerned with prescribed-time Nash equilibrium (PTNE) seeking problem in a pursuit-evasion game (PEG) involving agents with second-order dynamics. In order to achieve the prior given and user-defined convergence time for the PEG, a PTNE seeking algorithm has been developed to facilitate collaboration among multiple pursuers for capturing the evader without the need for any global information. Then, it is theoretically proved that the prescribed-time convergence of the designed algorithm for achieving Nash equilibrium of PEG. Eventually, the effectiveness of the PTNE method was validated by numerical simulation results.

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Multivalued Variational Inequalities With Generalized Fractional Φ-Laplacians, Vy Khoi Le Jun 2024

Multivalued Variational Inequalities With Generalized Fractional Φ-Laplacians, Vy Khoi Le

Mathematics and Statistics Faculty Research & Creative Works

In this article, we examine variational inequalities of the form (Formula presented.), where (Formula presented.) is a generalized fractional (Formula presented.) -Laplace operator, K is a closed convex set in a fractional Musielak–Orlicz–Sobolev space, and (Formula presented.) is a multivalued integral operator. We consider a functional analytic framework for the above problem, including conditions on the multivalued lower order term (Formula presented.) such that the problem can be properly formulated in a fractional Musielak–Orlicz–Sobolev space, and the involved mappings have certain useful monotonicity–continuity properties. Furthermore, we investigate the existence of solutions contingent upon certain coercivity conditions.

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Differential Methylation Region Detection Via An Array-Adaptive Normalized Kernelweighted Model, Daniel Alhassan, Gayla R. Olbricht, Akim Adekpedjou Jun 2024

Differential Methylation Region Detection Via An Array-Adaptive Normalized Kernelweighted Model, Daniel Alhassan, Gayla R. Olbricht, Akim Adekpedjou

Mathematics and Statistics Faculty Research & Creative Works

A differentially methylated region (DMR) is a genomic region that has significantly different methylation patterns between biological conditions. Identifying DMRs between different biological conditions is critical for developing disease biomarkers. Although methods for detecting DMRs in microarray data have been introduced, developing methods with high precision, recall, and accuracy in determining the true length of DMRs remains a challenge. In this study, we propose a normalized kernel-weighted model to account for similar methylation profiles using the relative probe distance from "nearby" CpG sites. We also extend this model by proposing an array-adaptive version in attempt to account for the differences …

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