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Long Lived Second Mode Internal Solitary Waves In The Andaman Sea, J.M. Magalhaes, J.C.B. Da Silva, Maarten C. Buijsman Jun 2020

Long Lived Second Mode Internal Solitary Waves In The Andaman Sea, J.M. Magalhaes, J.C.B. Da Silva, Maarten C. Buijsman

Faculty Publications

Internal waves are density oscillations propagating along the ocean’s inner stratification, which are now acknowledged as a key constituent of the ocean’s dynamics. They usually result from barotropic tides, which flow over bottom topography, causing density oscillations to propagate along the pycnocline with a tidal frequency (i.e. internal tides). These large-scale waves propagate away from their forcing bathymetry and frequently disintegrate into nonlinear short-scale (higher-frequency) internal wave packets. Typically, short-scale internal wave observations in the ocean are associated with vertical structures (in the water column) of the lowest fundamental mode. Higher vertical modes have recently been documented as well, but …


Effects Of Temperature And Antioxidants On The Oxidation Of Biodiesel Derived From Waste Vegetable Oil, Randy L. Maglinao, Torrey J. Wagner, Keegan Duff Jun 2020

Effects Of Temperature And Antioxidants On The Oxidation Of Biodiesel Derived From Waste Vegetable Oil, Randy L. Maglinao, Torrey J. Wagner, Keegan Duff

Faculty Publications

Biodiesel offers several environmental benefits and improvements to some fuel performance properties, but its poor oxidative stability has been a major concern. Currently, the accepted practice to improve biodiesel oxidative stability is the addition of antioxidants; numerous antioxidants have been studied but their effectiveness in inhibiting biodiesel oxidation is difficult to predict due to variation with resonance stability, solubility, reactivity, and volatility. To improve prediction efforts, this study explored the Rapid Small-Scale Oxidation Test (RSSOT) as a means to investigate how biodiesel oxidation is affected by antioxidant concentration and temperature, and compared its results with the oxidative stability index test. …


The Influence Of Stochasticity, Landscape Structure And Species Traits On Abundant–Centre Relationships, Tad Dallas, Luca Santini Jun 2020

The Influence Of Stochasticity, Landscape Structure And Species Traits On Abundant–Centre Relationships, Tad Dallas, Luca Santini

Faculty Publications

Species have been commonly hypothesized to have high population densities in geographic areas which correspond to either the centre of the species geographic range or climatic niche (abundant–centre hypothesis). However, there is mixed empirical support for this relationship, and little theoretical underpinning. We simulate a species spreading across a set of replicated artificial landscapes to examine the expected level of support for abundant–centre relationships in geographic and niche space. Species niche constraints were modeled as a single axis which was related directly to population growth rates. We found strong evidence for abundant–centre relationships when populations follow deterministic growth, dispersal is …


Gw190814: Gravitational Waves From The Coalescence Of A 23 Solar Mass Black Hole With A 2.6 Solar Mass Compact Object, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, K. Ackley, C. Adams, R. X. Adhikari, V. B. Adya, C. Affeldt, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, A. Aich, L. Aiello, A. Ain, P. Ajith, S. Akcay, G. Allen, A. Allocca, P. A. Altin, A. Amato, S. Anand, A. Ananyeva, S. B. Anderson, W. G. Anderson, S. V. Angelova, S. Ansoldi, S. Antier, S. Appert, K. Arai, Tiffany Z. Summerscales Jun 2020

Gw190814: Gravitational Waves From The Coalescence Of A 23 Solar Mass Black Hole With A 2.6 Solar Mass Compact Object, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, K. Ackley, C. Adams, R. X. Adhikari, V. B. Adya, C. Affeldt, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, A. Aich, L. Aiello, A. Ain, P. Ajith, S. Akcay, G. Allen, A. Allocca, P. A. Altin, A. Amato, S. Anand, A. Ananyeva, S. B. Anderson, W. G. Anderson, S. V. Angelova, S. Ansoldi, S. Antier, S. Appert, K. Arai, Tiffany Z. Summerscales

Faculty Publications

© 2020. The American Astronomical Society.. We report the observation of a compact binary coalescence involving a 22.2-24.3 M o˙ black hole and a compact object with a mass of 2.50-2.67 M o˙ (all measurements quoted at the 90% credible level). The gravitational-wave signal, GW190814, was observed during LIGO's and Virgo's third observing run on 2019 August 14 at 21:10:39 UTC and has a signal-to-noise ratio of 25 in the three-detector network. The source was localized to 18.5 deg2 at a distance of 241 +41-41 Mpc; no electromagnetic counterpart has been confirmed to date. The source has the most unequal …


Current Practices And Infrastructure For Open Data Based Research On Occupant-Centric Design And Operation Of Buildings, Mikkel B. Kjærgaard, Omid Ardakanian, Salvatore Carlucci, Bing Dong, Steven K. Firth, Nan Gao, Gesche Margarethe Huebner, Ardeshir Mahdavi, Mohammad Saiedur Rahaman, Flora D. Salim, Fisayo Caleb Sangogboye, Jens Hjort Schwee, Dawid Wolosiuk, Yimin Zhu Jun 2020

Current Practices And Infrastructure For Open Data Based Research On Occupant-Centric Design And Operation Of Buildings, Mikkel B. Kjærgaard, Omid Ardakanian, Salvatore Carlucci, Bing Dong, Steven K. Firth, Nan Gao, Gesche Margarethe Huebner, Ardeshir Mahdavi, Mohammad Saiedur Rahaman, Flora D. Salim, Fisayo Caleb Sangogboye, Jens Hjort Schwee, Dawid Wolosiuk, Yimin Zhu

Faculty Publications

Many new tools for improving the design and operation of buildings try to realize the potential of big data. In particular, data is an important element for occupant-centric design and operation as occupants’ presence and actions are affected by a high degree of uncertainty and, hence, are hard to model in general. For such research, data handling is an important challenge, and following an open science paradigm based on open data can increase efficiency and transparency of scientific work. This article reviews current practices and infrastructure for open data-driven research on occupant-centric design and operation of buildings. In particular, it …


Magic-Angle Semimetals With Chiral Symmetry, Yang Zhi Chou, Yang Zhi Chou, Yixing Fu, Justin H. Wilson, E. J. König, J. H. Pixley Jun 2020

Magic-Angle Semimetals With Chiral Symmetry, Yang Zhi Chou, Yang Zhi Chou, Yixing Fu, Justin H. Wilson, E. J. König, J. H. Pixley

Faculty Publications

We construct and solve a two-dimensional, chirally symmetric model of Dirac cones subjected to a quasiperiodic modulation. In real space, this is realized with a quasiperiodic hopping term. This hopping model, as we show, at the Dirac node energy has a rich phase diagram with a semimetal-to-metal phase transition at intermediate amplitude of the quasiperiodic modulation, and a transition to a phase with a diverging density of states (DOS) and subdiffusive transport when the quasiperiodic hopping is strongest. We further demonstrate that the semimetal-to-metal phase transition can be characterized by the multifractal structure of eigenstates in momentum space and can …


An Inverse Function Theorem Converse, Jimmie Lawson Jun 2020

An Inverse Function Theorem Converse, Jimmie Lawson

Faculty Publications

We establish the following converse of the well-known inverse function theorem. Let g:U→V and f:V→U be inverse homeomorphisms between open subsets of Banach spaces. If g is differentiable of class Cp and f is locally Lipschitz, then the Fréchet derivative of g at each point of U is invertible and f must be differentiable of class Cp.


Hamiltonian Theory Of Classical And Quantum Gauge Invariant Perturbations In Bianchi I Spacetimes, Ivan Agullo, Javier Olmedo, V. Sreenath Jun 2020

Hamiltonian Theory Of Classical And Quantum Gauge Invariant Perturbations In Bianchi I Spacetimes, Ivan Agullo, Javier Olmedo, V. Sreenath

Faculty Publications

We derive a Hamiltonian formulation of the theory of gauge invariant, linear perturbations in anisotropic Bianchi I spacetimes, and describe how to quantize this system. The matter content is assumed to be a minimally coupled scalar field with potential V(φ). We show that a Bianchi I spacetime generically induces both anisotropies and quantum entanglement on cosmological perturbations, and provide the tools to compute the details of these features. We then apply this formalism to a scenario in which the inflationary era is preceded by an anisotropic Bianchi I phase, and discuss the potential imprints in observable quantities. The formalism developed …


Search For Lepton-Flavor-Violating Decays D0→X0E±Μ∓, J. P. Lees, V. Poireau, V. Tisserand, E. Grauges, A. Palano, G. Eigen, D. N. Brown, Yu G. Kolomensky, M. Fritsch, H. Koch, T. Schroeder, R. Cheaib, C. Hearty, T. S. Mattison, J. A. Mckenna, R. Y. So, V. E. Blinov, A. R. Buzykaev, V. P. Druzhinin, Milind Purohit, Et. Al. Jun 2020

Search For Lepton-Flavor-Violating Decays D0→X0E±Μ∓, J. P. Lees, V. Poireau, V. Tisserand, E. Grauges, A. Palano, G. Eigen, D. N. Brown, Yu G. Kolomensky, M. Fritsch, H. Koch, T. Schroeder, R. Cheaib, C. Hearty, T. S. Mattison, J. A. Mckenna, R. Y. So, V. E. Blinov, A. R. Buzykaev, V. P. Druzhinin, Milind Purohit, Et. Al.

Faculty Publications

We present a search for seven lepton-flavor-violating neutral charm meson decays of the type D0→X0e±μ∓, where X0 represents a π0, K 0 S S, K0* ρ0, ϕ, ω, or η meson. The analysis is based on 468 fb−1 of e+e- annihilation data collected at or close to the Υ(4S)resonance with the BABAR detector at the SLAC National Accelerator Laboratory. No significant signals are observed, and we establish 90% confidence level upper limits on the branching fractions in …


A Highly Elastic And Fatigue-Resistant Natural Protein-Reinforced Hydrogel Electrolyte For Reversible-Compressible Quasi-Solid-State Supercapacitors, Jingya Nan, Gaitong Zhang, Tianyu Zhu, Zhongkai Wang, Lijun Wang, Hongsheng Wang, Fuxiang Chu, Chunpeng Wang, Chuanbing Tang Jun 2020

A Highly Elastic And Fatigue-Resistant Natural Protein-Reinforced Hydrogel Electrolyte For Reversible-Compressible Quasi-Solid-State Supercapacitors, Jingya Nan, Gaitong Zhang, Tianyu Zhu, Zhongkai Wang, Lijun Wang, Hongsheng Wang, Fuxiang Chu, Chunpeng Wang, Chuanbing Tang

Faculty Publications

Compressible solid-state supercapacitors are emerging as promising power sources for next-generation flexible electronics with enhanced safety and mechanical integrity. Highly elastic and compressible solid electrolytes are in great demand to achieve reversible compressibility and excellent capacitive stability of these supercapacitor devices. Here, a lithium ion-conducting hydrogel electrolyte by integrating natural protein nanoparticles into polyacrylamide network is reported. Due to the synergistic effect of natural protein nanoparticles and polyacrylamide chains, the obtained hydrogel shows remarkable elasticity, high compressibility, and fatigue resistance properties. More significantly, the supercapacitor device based on this hydrogel electrolyte exhibits reversible compressibility under multiple cyclic compressions, working well …


Fourier Propagation Tool For Aberration Analysis And A Point Spread Function Calculation Of Systems With Curved Focal Planes, Stephen C. Cain Jun 2020

Fourier Propagation Tool For Aberration Analysis And A Point Spread Function Calculation Of Systems With Curved Focal Planes, Stephen C. Cain

Faculty Publications

This paper describes a new Fourier propagator for computing the impulse response of an optical system with a curved focal plane array, while including terms ignored in Fresnel and Fraunhofer calculations. The propagator includes a Rayleigh-Sommerfeld diffraction formula calculation from a distant point through the optical system to its image point predicted by geometric optics on a spherical surface. The propagator then approximates the neighboring field points via the traditional binomial approximation of the Taylor series expansion around that field point. This technique results in a propagator that combines the speed of a Fourier transform operation with the accuracy of …


Heavy Metals In The Arctic: Distribution And Enrichment Of Five Metals In Alaskan Soils, Clarice R. Perryman, Jochen Wirsing, Kathryn A. Bennett, Owen Brennick, Apryl L. Perry, Nicole Williamson, Jessica G. Ernakovich Jun 2020

Heavy Metals In The Arctic: Distribution And Enrichment Of Five Metals In Alaskan Soils, Clarice R. Perryman, Jochen Wirsing, Kathryn A. Bennett, Owen Brennick, Apryl L. Perry, Nicole Williamson, Jessica G. Ernakovich

Faculty Publications

Metal contamination of food and water resources is a known public health issue in Arctic and sub-Arctic communities due to the proximity of many communities to mining and drilling sites. In addition, permafrost thaw may release heavy metals sequestered in previously frozen soils, potentially contaminating food and water resources by increasing the concentration of metals in freshwater, plants, and wildlife. Here we assess the enrichment of selected heavy metals in Alaskan soils by synthesizing publicly available data of soil metal concentrations. We analyzed data of soil concentrations of arsenic, chromium, mercury, nickel, and lead from over 1,000 samples available through …


Nondestructive Electromagnetic Characterization Of Uniaxial Sheet Media Using A Two-Flanged Rectangular Waveguide Probe, Neil G. Rogers, Michael J. Havrilla, Milo W. Hyde Iv, Alexander G. Knisely Jun 2020

Nondestructive Electromagnetic Characterization Of Uniaxial Sheet Media Using A Two-Flanged Rectangular Waveguide Probe, Neil G. Rogers, Michael J. Havrilla, Milo W. Hyde Iv, Alexander G. Knisely

Faculty Publications

Excerpt: Recent advancements in fabrication capabilities have renewed interest in the electromagnetic characterization of complex media, as many metamaterials are anisotropic and/or inhomogeneous. Additionally, for composite materials, anisotropy can be introduced by load, strain, misalignment, or damage through the manufacturing process [1], [2]. Methods for obtaining the constitutive parameters for isotropic materials are well understood and widely employed [3]–[8]. Therefore, it is crucial to develop a practical method for the electromagnetic characterization of anisotropic materials.


Coherent Quantum Channel Discrimination, Mark M. Wilde Jun 2020

Coherent Quantum Channel Discrimination, Mark M. Wilde

Faculty Publications

This paper introduces coherent quantum channel discrimination as a coherent version of conventional quantum channel discrimination. Coherent channel discrimination is phrased here as a quantum interactive proof system between a verifier and a prover, wherein the goal of the prover is to distinguish two channels called in superposition in order to distill a Bell state at the end. The key measure considered here is the success probability of distilling a Bell state, and I prove that this success probability does not increase under the action of a quantum super-channel, thus establishing this measure as a fundamental measure of channel distinguishability. …


Hartree-Fock-Bogoliubov Theory Of Trapped One-Dimensional Imbalanced Fermi Systems, Daniel E. Sheehy Jun 2020

Hartree-Fock-Bogoliubov Theory Of Trapped One-Dimensional Imbalanced Fermi Systems, Daniel E. Sheehy

Faculty Publications

Ground-state Hartree-Fock-Bogoliubov (HFB) theory is applied to imbalanced spin-1/2 one-dimensional (1D) Fermi systems that are spatially confined by either a harmonic or a hard-wall trapping potential. It has been hoped that such systems, which can be realized using ultracold atomic gases, would exhibit the long-sought-after Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) superfluid phase. The HFB formalism generalizes the standard Bogoliubov quasiparticle transformation by allowing for Cooper pairing to exist between all possible single-particle states and accounts for the effects of the inhomogeneous trapping potential as well as the mean-field Hartree potential. This provides an unbiased framework to describe inhomogeneous densities and pairing correlations in …


Multiparticle Quantum Plasmonics, Chenglong You, Apurv Chaitanya Nellikka, Israel De Leon, Omar S. Magaña-Loaiza Jun 2020

Multiparticle Quantum Plasmonics, Chenglong You, Apurv Chaitanya Nellikka, Israel De Leon, Omar S. Magaña-Loaiza

Faculty Publications

A single photon can be coupled to collective charge oscillations at the interfaces between metals and dielectrics forming a single surface plasmon. The electromagnetic near-fields induced by single surface plasmons offer new degrees of freedom to perform an exquisite control of complex quantum dynamics. Remarkably, the control of quantum systems represents one of the most significant challenges in the field of quantum photonics. Recently, there has been an enormous interest in using plasmonic systems to control multiphoton dynamics in complex photonic circuits. In this review, we discuss recent advances that unveil novel routes to control multiparticle quantum systems composed of …


Search For Magnetically-Induced Signatures In The Arrival Directions Of Ultra-High-Energy Cosmic Rays Measured At The Pierre Auger Observatory, I. C. Maris, J. Pekala, R. Smda, J. Supk, A. Aab, P. Abreu, M. Aglietta, J. M. Albury, I. Allekotte, A. Almela, J. Alvarez Castillo, J. Alvarez-Muñiz, R. Alves Batista, G. A. Anastasi, L. Anchordoqui, B. Andrada, S. Andringa, C. Aramo, P. R.Araújo Ferreira, H. Asorey, P. Assis, G. Avila, A. M. Badescu, A. Bakalova, A. Balaceanu, F. Barbato, R. J.Barreira Luz, K. H. Becker, J. A. Bellido, C. Berat, M. E. Bertaina, X. Bertou, P. L. Biermann Jun 2020

Search For Magnetically-Induced Signatures In The Arrival Directions Of Ultra-High-Energy Cosmic Rays Measured At The Pierre Auger Observatory, I. C. Maris, J. Pekala, R. Smda, J. Supk, A. Aab, P. Abreu, M. Aglietta, J. M. Albury, I. Allekotte, A. Almela, J. Alvarez Castillo, J. Alvarez-Muñiz, R. Alves Batista, G. A. Anastasi, L. Anchordoqui, B. Andrada, S. Andringa, C. Aramo, P. R.Araújo Ferreira, H. Asorey, P. Assis, G. Avila, A. M. Badescu, A. Bakalova, A. Balaceanu, F. Barbato, R. J.Barreira Luz, K. H. Becker, J. A. Bellido, C. Berat, M. E. Bertaina, X. Bertou, P. L. Biermann

Faculty Publications

We search for signals of magnetically-induced effects in the arrival directions of ultra-high-energy cosmic rays detected at the Pierre Auger Observatory. We apply two different methods. One is a search for sets of events that show a correlation between their arrival direction and the inverse of their energy, which would be expected if they come from the same point-like source, they have the same electric charge and their deflection is relatively small and coherent. We refer to these sets of events as "multiplets". The second method, called "thrust", is a principal axis analysis aimed to detect the elongated patterns in …


Simultaneous Measurement Of The Muon Neutrino Charged-Current Cross Section On Oxygen And Carbon Without Pions In The Final State At T2k, A. Zykova, K. Abe, N. Akhlaq, R. Akutsu, A. Ali, C. Alt, C. Andreopoulos, L. Anthony, M. Antonova, S. Aoki, A. Ariga, T. Arihara, Y. Asada, Y. Ashida, E. T. Atkin, Y. Awataguchi, S. Ban, M. Barbi, G. J. Barker, G. Barr, D. Barrow, M. Batkiewicz-Kwasniak, A. Beloshapkin, F. Bench, V. Berardi, L. Berns, S. Bhadra, S. Bienstock Jun 2020

Simultaneous Measurement Of The Muon Neutrino Charged-Current Cross Section On Oxygen And Carbon Without Pions In The Final State At T2k, A. Zykova, K. Abe, N. Akhlaq, R. Akutsu, A. Ali, C. Alt, C. Andreopoulos, L. Anthony, M. Antonova, S. Aoki, A. Ariga, T. Arihara, Y. Asada, Y. Ashida, E. T. Atkin, Y. Awataguchi, S. Ban, M. Barbi, G. J. Barker, G. Barr, D. Barrow, M. Batkiewicz-Kwasniak, A. Beloshapkin, F. Bench, V. Berardi, L. Berns, S. Bhadra, S. Bienstock

Faculty Publications

This paper reports the first simultaneous measurement of the double differential muon neutrino charged-current cross section on oxygen and carbon without pions in the final state as a function of the outgoing muon kinematics, made at the ND280 off-axis near detector of the T2K experiment. The ratio of the oxygen and carbon cross sections is also provided to help validate various models' ability to extrapolate between carbon and oxygen nuclear targets, as is required in T2K oscillation analyses. The data are taken using a neutrino beam with an energy spectrum peaked at 0.6 GeV. The extracted measurement is compared with …


First Combined Measurement Of The Muon Neutrino And Antineutrino Charged-Current Cross Section Without Pions In The Final State At T2k, K. Abe, N. Akhlaq, R. Akutsu, A. Ali, C. Alt, C. Andreopoulos, L. Anthony, M. Antonova, S. Aoki, A. Ariga, T. Arihara, Y. Asada, Y. Ashida, E. T. Atkin, Y. Awataguchi, S. Ban, M. Barbi, G. J. Barker, G. Barr, D. Barrow, C. Barry, M. Batkiewicz-Kwasniak, A. Beloshapkin, F. Bench, V. Berardi, L. Berns, S. Bhadra, S. Bienstock Jun 2020

First Combined Measurement Of The Muon Neutrino And Antineutrino Charged-Current Cross Section Without Pions In The Final State At T2k, K. Abe, N. Akhlaq, R. Akutsu, A. Ali, C. Alt, C. Andreopoulos, L. Anthony, M. Antonova, S. Aoki, A. Ariga, T. Arihara, Y. Asada, Y. Ashida, E. T. Atkin, Y. Awataguchi, S. Ban, M. Barbi, G. J. Barker, G. Barr, D. Barrow, C. Barry, M. Batkiewicz-Kwasniak, A. Beloshapkin, F. Bench, V. Berardi, L. Berns, S. Bhadra, S. Bienstock

Faculty Publications

This paper presents the first combined measurement of the double-differential muon neutrino and antineutrino charged-current cross sections with no pions in the final state on hydrocarbon at the off-axis near detector of the T2K experiment. The data analyzed in this work comprise 5.8×1020 and 6.3×1020 protons on target in neutrino and antineutrino mode respectively, at a beam energy peak of 0.6 GeV. Using the two measured cross sections, the sum, difference, and asymmetry were calculated with the aim of better understanding the nuclear effects involved in such interactions. The extracted measurements have been compared with the prediction from different Monte …


Fine Structure Of Angular Distribution Of X-Ray Transition Radiation From Multilayered Radiator In Geant4, A. A. Savchenko, A. A. Tishchenko, D. Yu Sergeeva, N. Belyaev, M. Cherry, F. Dachs, S. Doronin, K. Filippov, P. Fusco, F. Gargano, S. Konovalov, F. Loparco, V. Mascagna, M. N. Mazziotta, S. Nechaeva, D. Ponomarenko, A. Romaniouk, E. J. Schioppa, S. Smirnov, Y. Smirnov, M. Soldani, P. Spinelli, M. N. Strikhanov, P. Teterin, V. O. Tikhomirov, K. Vorobev, K. Zhukov Jun 2020

Fine Structure Of Angular Distribution Of X-Ray Transition Radiation From Multilayered Radiator In Geant4, A. A. Savchenko, A. A. Tishchenko, D. Yu Sergeeva, N. Belyaev, M. Cherry, F. Dachs, S. Doronin, K. Filippov, P. Fusco, F. Gargano, S. Konovalov, F. Loparco, V. Mascagna, M. N. Mazziotta, S. Nechaeva, D. Ponomarenko, A. Romaniouk, E. J. Schioppa, S. Smirnov, Y. Smirnov, M. Soldani, P. Spinelli, M. N. Strikhanov, P. Teterin, V. O. Tikhomirov, K. Vorobev, K. Zhukov

Faculty Publications

The present version of the Transition Radiation (TR) simulation module implemented in the Geant4 toolkit describes very well experimental data for the TR energy distribution; however, it does not allow reproducing the details of angular distribution at small angles. In order to solve this problem, corrections to the existing x-ray TR module in Geant4 are proposed. With these corrections, the results of the simulations are in a good agreement with the angular TR distributions predicted by theory and obtained in the test beam measurements using a 480 um Si pixel detector and Mylar radiator.


A Note On Species Richness And The Variance Of Epidemic Severity, Peter Shaffery, Bret D. Elderd, Vanja Dukic Jun 2020

A Note On Species Richness And The Variance Of Epidemic Severity, Peter Shaffery, Bret D. Elderd, Vanja Dukic

Faculty Publications

© 2020, Springer-Verlag GmbH Germany, part of Springer Nature. The commonly observed negative correlation between the number of species in an ecological community and disease risk, typically referred to as “the dilution effect”, has received a substantial amount of attention over the past decade. Attempts to test this relationship experimentally have revealed that, in addition to the mean disease risk decreasing with species number, so too does the variance of disease risk. This is referred to as the “variance reduction effect”, and has received relatively little attention in the disease-diversity literature. Here, we set out to clarify and quantify some …


Improving Estimates For Discrete Polynomial Averages, Rui Han, Vjekoslav Kovač, Michael T. Lacey, José Madrid, Fan Yang Jun 2020

Improving Estimates For Discrete Polynomial Averages, Rui Han, Vjekoslav Kovač, Michael T. Lacey, José Madrid, Fan Yang

Faculty Publications

For a polynomial P mapping the integers into the integers, define an averaging operator ANf(x):=1N∑k=1Nf(x+P(k)) acting on functions on the integers. We prove sufficient conditions for the ℓp-improving inequality ‖ANf‖ℓq(Z)≲P,p,qN-d(1p-1q)‖f‖ℓp(Z),N∈N,where 1 ≤ p≤ q≤ ∞. For a range of quadratic polynomials, the inequalities established are sharp, up to the boundary of the allowed pairs of (p, q). For degree three and higher, the inequalities are close to being sharp. In the quadratic case, we appeal to discrete fractional integrals as studied by Stein and Wainger. In the higher degree case, we appeal to the Vinogradov Mean Value Theorem, recently established …


Multiscale-Spectral Gfem And Optimal Oversampling, Ivo Babuška, Robert Lipton, Paul Sinz, Michael Stuebner Jun 2020

Multiscale-Spectral Gfem And Optimal Oversampling, Ivo Babuška, Robert Lipton, Paul Sinz, Michael Stuebner

Faculty Publications

In this work we address the Multiscale Spectral Generalized Finite Element Method (MS-GFEM) developed in Babuška and Lipton (2011). We outline the numerical implementation of this method and present simulations that demonstrate contrast independent exponential convergence of MS-GFEM solutions. We introduce strategies to reduce the computational cost of generating the optimal oversampled local approximating spaces used here. These strategies retain accuracy while reducing the computational work necessary to generate local bases. Motivated by oversampling we develop a nearly optimal local basis based on a partition of unity on the boundary and the associated A-harmonic extensions.


Classification Of Super-Modular Categories By Rank, Paul Bruillard, César Galindo, Siu Hung Ng, Julia Y. Plavnik, Eric C. Rowell, Zhenghan Wang Jun 2020

Classification Of Super-Modular Categories By Rank, Paul Bruillard, César Galindo, Siu Hung Ng, Julia Y. Plavnik, Eric C. Rowell, Zhenghan Wang

Faculty Publications

We pursue a classification of low-rank super-modular categories parallel to that of modular categories. We classify all super-modular categories up to rank = 6, and spin modular categories up to rank = 11. In particular, we show that, up to fusion rules, there is exactly one non-split super-modular category of rank 2, 4 and 6, namely PSU(2)4k+ 2 for k = 0,1 and 2. This classification is facilitated by adapting and extending well-known constraints from modular categories to super-modular categories, such as Verlinde and Frobenius-Schur indicator formulae.


Projecting Stand Survival And Basal Area Based On A Self-Thinning Model For Chinese Fir Plantations, Xiongqing Zhang, Quang V. Cao, Hanchen Wang, Aiguo Duan, Jianguo Zhang Jun 2020

Projecting Stand Survival And Basal Area Based On A Self-Thinning Model For Chinese Fir Plantations, Xiongqing Zhang, Quang V. Cao, Hanchen Wang, Aiguo Duan, Jianguo Zhang

Faculty Publications

The self-thinning rule has played a critical role in controlling stand stocking and modeling stand development in forest stands. Chinese fir (Cunninghamia lanceolata) is a native and fast-growing tree species used for timber production and is widely grown in southern China. Effective management of this important tree species requires accurate and reasonable predictions of stand growth and survival. Remeasured data from 48 plots distributed in Fujian, Jiangxi, Guangxi, and Sichuan provinces were used to develop models to predict stand survival and basal area based on the self-thinning trajectories. These trajectories were constructed using a self-thinning slope of -1.605, as suggested …


The Importance Of Infrequent, High-Intensity Rainfall Events For Longleaf Pine (Pinus Palustris Mill.) Radial Growth And Implications For Dendroclimatic Research, Tyler J. Mitchell, Paul A. Knapp, Thomas W. Patterson Jun 2020

The Importance Of Infrequent, High-Intensity Rainfall Events For Longleaf Pine (Pinus Palustris Mill.) Radial Growth And Implications For Dendroclimatic Research, Tyler J. Mitchell, Paul A. Knapp, Thomas W. Patterson

Faculty Publications

Tree-ring based precipitation reconstructions are beneficial in placing interannual variability in an historical context. However, absent specificity on what is being modeled (e.g., event type or rainfall intensity), similar rainfall totals inferred from reconstructions between different years imply similar conditions. Consequently, variability in specific precipitation event types or intensity can affect radial growth widths despite no changes in overall precipitation amount. Here, we use a longleaf pine latewood chronology to demonstrate how infrequent, intense (i.e., > 2.0 SD above mean) rainfall events (IREs), representing ~ 50% of total summer (July–September) precipitation amounts and 14.1% of rainfall events, principally determine interannual variability …


Battlespace Next™: Developing A Serious Game To Explore Multi-Domain Operations, Nathaniel Flack, Alan C. Lin, Gilbert L. Peterson, Mark G. Reith Jun 2020

Battlespace Next™: Developing A Serious Game To Explore Multi-Domain Operations, Nathaniel Flack, Alan C. Lin, Gilbert L. Peterson, Mark G. Reith

Faculty Publications

Changes in the geopolitical landscape and increasing technological complexity have prompted the U.S. Military to coin the terms Multi-Domain Operations (MDO) and Joint All-Domain Command and Control (JADC2) as over-arching strategy to frame the complexity of warfare across both traditional and emerging warfighting domains. Teaching new concepts associated with these terms requires both innovation as well as distinct education and training tools in order to realize the cultural change advocated by senior military leaders. Battlespace Next™ (BSN) is a serious game designed to teach concepts integral to MDO and initiate discussion on military strategy while conserving time, money, and manpower. …


Introducing The Journal Of Nuclear Engineering: An Interdisciplinary Open Access Journal Dedicated To Publishing Research In Nuclear And Radiation Sciences And Applications, Dan Gabriel Cacuci May 2020

Introducing The Journal Of Nuclear Engineering: An Interdisciplinary Open Access Journal Dedicated To Publishing Research In Nuclear And Radiation Sciences And Applications, Dan Gabriel Cacuci

Faculty Publications

Note: In lieu of an abstract, this is an excerpt from the first page.


In 1938, Strassmann, Hahn and Meitner discovered neutron-induced nuclear fission in uranium, forever changing our world and opening multiple paths to developing nuclear energy, nuclear medicine, instrumentation, space propulsion, environmental monitoring, remediation and nuclear security [...]


Symmetry Energy Of Super-Dense Neutron-Rich Matter From Integrating Barotropic Pressures In Neutron Stars And Heavy-Ion Reactions, Bao-An Li, Wen-Jie Xie May 2020

Symmetry Energy Of Super-Dense Neutron-Rich Matter From Integrating Barotropic Pressures In Neutron Stars And Heavy-Ion Reactions, Bao-An Li, Wen-Jie Xie

Faculty Publications

Within the minimum model of neutron stars (NS) consisting of neutrons, protons and electrons, a new approach is proposed for inferring the symmetry energy of super-dense neutron-rich nucleonic matter above twice the saturation density ρ0 of nuclear matter directly from integrating iteratively barotropic pressures in both neutron stars and heavy-ion reactions. Simultaneously, the proton fraction of NSs at β equilibrium is extracted as a function of baryon density from the same procedure. An application of this approach using the NS pressure from GW170817 and the pressure in cold symmetric nuclear matter (SNM) extracted earlier by analyzing nuclear collective flow data …


Attosecond Time-Domain Measurement Of Core-Level-Exciton Decay In Magnesium Oxide, Romain Géneaux, Christopher J. Kaplan, Lun Yue, Andrew D. Ross, Jens E. Bækhøj, Peter M. Kraus, Hung Tzu Chang, Alexander Guggenmos, Mi Ying Huang, Michael Zürch, Kenneth J. Schafer, Daniel M. Neumark, Mette B. Gaarde, Stephen R. Leone May 2020

Attosecond Time-Domain Measurement Of Core-Level-Exciton Decay In Magnesium Oxide, Romain Géneaux, Christopher J. Kaplan, Lun Yue, Andrew D. Ross, Jens E. Bækhøj, Peter M. Kraus, Hung Tzu Chang, Alexander Guggenmos, Mi Ying Huang, Michael Zürch, Kenneth J. Schafer, Daniel M. Neumark, Mette B. Gaarde, Stephen R. Leone

Faculty Publications

Excitation of ionic solids with extreme ultraviolet pulses creates localized core-level excitons, which in some cases couple strongly to the lattice. Here, core-level-exciton states of magnesium oxide are studied in the time domain at the Mg L2,3 edge with attosecond transient reflectivity spectroscopy. Attosecond pulses trigger the excitation of these short-lived quasiparticles, whose decay is perturbed by time-delayed near-infrared pulses. Combined with a few-state theoretical model, this reveals that the infrared pulse shifts the energy of bright (dipole-allowed) core-level-exciton states as well as induces features arising from dark core-level excitons. We report coherence lifetimes for the two lowest core-level excitons …