cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Evaluation of Diffusion of Liquid Solvents in Bitumen and Heavy Oil Using the X-Ray Tomography Technique
Creators: name: Chaustre Ruiz, Andres Javier
Publisher: name: Schulich School of Engineering
Year: 2022
Subjects: subject: Diffusion coefficient
subject: Mass transfer
subject: Solvents
subject: Heavy oil
subject: Bitumen
subject: CT-Scanner
subject: Asphaltene
subject: Engineering--Chemical
subject: Engineering--Petroleum

description: The overall goal of this study was to conduct a series of diffusivity experiments between liquid hydrocarbons (propane and pentane) and Canadian bitumen and heavy oil in order to attempt to determine the role of different factors such as asphaltene precipitation and settling, among others, in these mass transfer processes. An apparatus was constructed and commissioned to measure the mass transfer in these systems based on the density profiles established over time in aluminum vessels containing a column of solvent over bitumen/heavy oil. The vessels were scanned regularly using a CT-Scanner in order to track the behavior of the density profiles over time, the liquid-liquid mass transfer data were collected and analyzed, obtaining interesting results, which will be important as a starting point for future research related to systems that integrate interactions between solvents and oils in recovery processes as VAPEX. This research is unique due to the obtained results; one of the findings, which was never published in previous literature, was the partial miscibility when mixing n-propane and bitumen, and another results to highlight are the oil swelling, oil shrinkage, asphaltene precipitation and settling, fully miscibility, and the effect of adding pure asphaltenes and calcium carbonate to the mixture, among others. It was found that partial miscibility was not manifested for all the cases (this condition occurred in cases when solvents and oils were mixed at certain solvent fractions). It was determined that oil is the controlling factor in the diffusion process when partial miscibility exists. Diffusion coefficients were calculated for all cases, and it was determined that diffusion is concentration dependent.
Overlapping Schwarz methods with GenEO coarse spaces for indefinite and non-self-adjoint problems
Creators: name: Bootland, Niall
name: Dolean, Victorita
name: Graham, Ivan G.
name: Ma, Chupeng
name: Scheichl, Robert
Publisher: name: arXiv
Year: 2021
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 65N22, 65N55, 65F10

description: GenEO (`Generalised Eigenvalue problems on the Overlap') is a method for computing an operator-dependent spectral coarse space to be combined with local solves on subdomains to form a robust parallel domain decomposition preconditioner for elliptic PDEs. It has previously been proved, in the self-adjoint and positive-definite case, that this method, when used as a preconditioner for conjugate gradients, yields iteration numbers which are completely independent of the heterogeneity of the coefficient field of the partial differential operator. We extend this theory to the case of convection-diffusion-reaction problems, which may be non-self-adjoint and indefinite, and whose discretisations are solved with preconditioned GMRES. The GenEO coarse space is defined here using a generalised eigenvalue problem based on a self-adjoint and positive-definite subproblem. We prove estimates on GMRES iteration counts which are independent of the variation of the coefficient of the diffusion term in the operator and depend only very mildly on variations of the other coefficients. These are proved under the assumption that the subdomain diameter is sufficiently small and the eigenvalue tolerance for building the coarse space is sufficiently large. While the iteration number estimates do grow as the non-self-adjointness and indefiniteness of the operator increases, practical tests indicate the deterioration is much milder. Thus we obtain an iterative solver which is efficient in parallel and very effective for a wide range of convection--diffusion--reaction problems.
Bifurcation and local rigidity of homogeneous solutions to the Yamabe problem on spheres
Creators: name: Bettiol, Renato G.
name: Piccione, Paolo
Publisher: name: arXiv
Year: 2011
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53C30, 58J55, 53C20, 53C24, 58E07, 58E50

description: We study existence and non-existence of constant scalar curvature metrics conformal and arbitrarily close to homogeneous metrics on spheres, using variational techniques. This describes all critical points of the Hilbert-Einstein functional on such conformal classes, near homogeneous metrics. Both bifurcation and local rigidity type phenomena are obtained for 1-parameter families of U(n+1), Sp(n+1) and Spin(9)-homogeneous metrics.
description: LaTeX2e, 18 pages, 1 figure, revised version. To appear in Calc. Var. and PDEs
A sensitive cloud chamber without radioactive sources
Creators: name: Zeze, Syoji
name: Itoh, Akio
name: Oyama, Ayu
name: Takahashi, Haruka
Publisher: name: arXiv
Year: 2012
Subjects: subject: Popular Physics (physics.pop-ph)
subject: Physics Education (physics.ed-ph)
subject: FOS: Physical sciences

description: We present a sensitive diffusion cloud chamber which does not require any radioactive sources. A major difference from a commonly used chamber is use of a heat sink as its bottom plate. A result of a performance test of the chamber is given.
description: 8 pages, 8 figures, iopart.cls, figures and references added
Continuum modeling of freeway traffic flows: State-of-the-art, challenges and future directions in the era of connected and automated vehicles
Creators: name: Mohammadian, Saeed
name: Zheng, Zuduo
name: Haque, Md. Mazharul
name: Bhaskar, Ashish
Publisher: name: arXiv
Year: 2021
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: Connected and automated vehicles (CAVs) are expected to reshape traffic flow dynamics and present new challenges and opportunities for traffic flow modeling. While numerous studies have proposed optimal modeling and control strategies for CAVs with various objectives (e.g., traffic efficiency and safety), there are uncertainties about the flow dynamics of CAVs in real-world traffic. The uncertainties are especially amplified for mixed traffic flows, consisting of CAVs and human-driven vehicles, where the implications can be significant from the continuum-modeling perspective, which aims to capture macroscopic traffic flow dynamics based on hyperbolic systems of partial differential equations. This paper aims to highlight and discuss some essential problems in continuum modeling of real-world freeway traffic flows in the era of CAVs. We first provide a select review of some existing continuum models for conventional human-driven traffic as well as the recent attempts for incorporating CAVs into the continuum-modeling framework. Wherever applicable, we provide new insights about the properties of existing models and revisit their implications for traffic flows of CAVs using recent empirical observations with CAVs and the previous discussions and debates in the literature. The paper then discusses some major problems inherent to continuum modeling of real-world (mixed) CAV traffic flows modeling by distinguishing between two major research directions: (a) modeling for explaining purposes, where making reproducible inferences about the physical aspects of macroscopic properties is of the primary interest, and (b) modeling for practical purposes, in which the focus is on the reliable predictions for operation and control. The paper proposes some potential solutions in each research direction and recommends some future research topics.
A note on conjectures of F. Galvin and R. Rado
Creators: name: Dorais, François G.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Logic (math.LO)
subject: FOS: Mathematics
subject: 03E05 (Primary) 03E35 03E55 (Secondary)

description: In 1968, Galvin conjectured that an uncountable poset $P$ is the union of countably many chains if and only if this is true for every subposet $Q \subseteq P$ with size $\aleph_1$. In 1981, Rado formulated a similar conjecture that an uncountable interval graph $G$ is countably chromatic if and only if this is true for every induced subgraph $H \subseteq G$ with size $\aleph_1$. Todorcevic has shown that Rado's Conjecture is consistent relative to the existence of a supercompact cardinal, while the consistency of Galvin's Conjecture remains open. In this paper, we survey and collect a variety of results related to these two conjectures. We also show that the extension of Rado's conjecture to the class of all chordal graphs is relatively consistent with the existence of a supercompact cardinal.
description: To appear in the Canadian Mathematical Bulletin
Studying dark matter with MadDM: lines and loops
Creators: name: Massaro, Daniele
name: Arina, Chiara
name: Heisig, Jan
name: Maltoni, Fabio
name: Mattelaer, Olivier
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Automated tools for the computation of amplitudes and cross sections have become the backbone of phenomenological studies beyond the standard model. We present the latest developments in MadDM, a calculator of dark-matter observables based on MadGraph5_aMC@NLO. The new version enables the fully automated computation of loop-induced annihilation processes, relevant for indirect detection of dark matter. Of particular interest is the direct annihilation into photons, $γγ,\, γX$. These processes lead to monochromatic gamma-ray lines that are smoking-gun signatures for dark-matter annihilation in our Galaxy. MadDM computes the predictions for the expected photon fluxes near Earth and derives constraints from the gamma-ray line searches by Fermi-LAT and HESS. As an application, we present the implications for the parameter space of the Inert Doublet Model.
description: 5 pages, 1 figure; proceedings of the "17th International Conference on Topics in Astroparticle and Underground Physics" (TAUP 2021)
Bubble collision with gravitation
Creators: name: Hwang, Dong-il
name: Lee, Bum-Hoon
name: Lee, Wonwoo
name: Yeom, Dong-han
Publisher: name: arXiv
Year: 2012
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this paper, we study vacuum bubble collisions with various potentials including gravitation, assuming spherical, planar, and hyperbolic symmetry. We use numerical calculations from double-null formalism. Spherical symmetry can mimic the formation of a black hole via multiple bubble collisions. Planar and especially hyperbolic symmetry describes two bubble collisions. We study both cases, when two true vacuum regions have the same field value or different field values, by varying tensions. For the latter case, we also test symmetric and asymmetric bubble collisions, and see details of causal structures. If the colliding energy is sufficient, then the vacuum can be destabilized, and it is also demonstrated. This double-null formalism can be a complementary approach in the context of bubble collisions.
description: 31 pages, 19 figures
Disorder correlations at smeared phase transitions
Creators: name: Svoboda, Christopher
name: Nozadze, David
name: Hrahsheh, Fawaz
name: Vojta, Thomas
Publisher: name: arXiv
Year: 2011
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: We investigate the influence of spatial disorder correlations on smeared phase transitions, taking the quantum phase transition in itinerant magnets as an example. We find that even short-range correlations can have a dramatic effect and qualitatively change the behavior of observable quantities. This is in marked contrast to conventional critical phenomena, at which short-range disorder correlations are irrelevant. We develop an optimal fluctuation theory of the quantum phase transition in the presence of correlated disorder, and we illustrate the results by computer simulations. As an experimental application, we discuss the ferromagnetic quantum phase transition in Sr$_{1-x}$Ca$_x$RuO$_3$.
description: 6 pages, 4 eps figures, final version as published
Additional file 2 of Exosome-derived circKIF20B suppresses gefitinib resistance and cell proliferation in non-small cell lung cancer
Creators: name: Wei, Si-Liang
name: Ye, Jing-Jing
name: Sun, Li
name: Hu, Lei
name: Wei, Yuan-Yuan
name: Zhang, Da-Wei
name: Xu, Meng-Meng
name: Fei, Guang-He
Publisher: name: figshare
Year: 2023
Subjects: subject: Biophysics
subject: Biochemistry
subject: Cell Biology
subject: Genetics
subject: FOS: Biological sciences
subject: Molecular Biology
subject: Pharmacology
subject: Biotechnology
subject: Biological Sciences not elsewhere classified
subject: Developmental Biology
subject: Cancer
subject: Hematology

description: Additional file 2 (Figure S1-S2).
$L^2$-Density of Wild Initial Data for the Hypodissipative Navier-Stokes Equations
Creators: name: Gorini, Michele
Publisher: name: arXiv
Year: 2021
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: In this paper we deal with the Cauchy problem for the hypodissipative Navier-Stokes equations in the three-dimensional periodic setting. For all Laplacian exponents $θ<\frac13$, we prove non-uniqueness of dissipative $L^2_tH^θ_x$ weak solutions for an $L^2$-dense set of $\mathcal C^β$ Hölder continuous wild initial data with $θ<β<\frac13$. This improves previous results of non-uniqueness for infinitely many wild initial data ([8,20]) and generalizes previous results on density of wild initial data obtained for the Euler equations ([14, 13]).
description: arXiv admin note: text overlap with arXiv:2004.00391 by other authors
Attack and Parry: An Examination of Gubernatorial Rhetoric and Agenda Setting for Higher Education in Texas, 2000-2015
Creators: name: Drake, A.
name: Marsicano, C.
Publisher: name: Texas Education Review
Year: 2018
Subjects: higher education
governors
agenda setting
state politics

description: This paper applies political discourse analysis to an examination of gubernatorial rhetoric and agenda setting around higher education in Texas during Governor Rick Perry’s leadership, from 2000-2015. The authors analyzed 28 gubernatorial speeches using manifest content analysis in STATA and qualitative coding via pattern matching in Atlas.ti. Findings reveal that Governor Rick Perry: 1) framed the higher education agenda around reform strategies to increase accountability, efficiency, and affordability; 2) functioned as both an agenda setter and policy entrepreneur; and 3) primed constituents to support his agenda by positioning higher education as a workforce development mechanism and invoking Texas’s tradition of leadership and competitiveness.
Volatilization and partitioning of residual electronic cigarette emissions to particulate matter
Creators: name: Colby, Henry J.
name: Katz, Erin F.
name: DeCarlo, Peter F.
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Biochemistry
subject: Microbiology
subject: FOS: Biological sciences
subject: Pharmacology
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: 69999 Biological Sciences not elsewhere classified
subject: Science Policy

description: The growing prevalence of electronic cigarettes (e-cigs) prompts investigation of their impact on indoor air quality. While the investigation of residual cigarette smoke, also known as third-hand smoke (THS), has been increasing, there is minimal literature on similar residue from e-cig emissions. Lab generated ammonium sulfate aerosol was introduced into a stainless-steel chamber which previously contained JUUL electronic cigarette vape. Aerosol composition was monitored using a high-resolution aerosol mass spectrometer. This was performed in the same chamber 3 times over 5 days. Species from electronic cigarette residue (nicotine and vegetable glycerin) were found to partition to particles with decreasing concentration over the multiple experiments while maintaining a consistent chemical signature. This signature matches closely to that of the primary electronic cigarette vape with notable exclusions of propylene glycol, benzoic acid, and cadmium. Electronic cigarette vape can deposit onto surfaces and act as a long-term source of gas phase nicotine which can concentrate on aerosols and increase human exposure. The chemical processing of vape residue observed here is less substantial than has been previously presented for residual cigarette smoke. While our experiments were performed under controlled conditions, they highlight the importance of understanding indoor electronic cigarette use and unintended routes of exposure. Copyright © 2023 American Association for Aerosol Research
Transcending sovereignty : locating Indigenous peoples in transboundary water law
Creators: name: Archer, Jennifer Lynne
Publisher: name: University of British Columbia
Year: 2012

description: All people rely upon water for life. Indigenous peoples are especially vulnerable to water conflicts and yet lack recognition in international water law. This thesis adopts Critical Race Theory to examine the intersection between transboundary water law, the doctrine of sovereignty and the international law of Indigenous peoples. The methodology adopted in this thesis includes: (i) a deconstruction of the UN Watercourse Convention and the doctrine of sovereignty; (ii) a review of Indigenous perspectives on sovereignty; and (iii) a proposal for the reconstruction of transboundary water law in a manner that recognizes the internationally affirmed rights of Indigenous peoples. A deconstruction of the UN Watercourse Convention and related discourse reveals that state-centric approaches to transboundary water law fail to recognize Indigenous peoples’ international rights or the pivotal role that Indigenous peoples’ traditional knowledge might play in transcending conflict. Case examples are provided (Columbia River and Tsangpo-Brahmaputra River) that illustrate the vulnerability of Indigenous peoples in the face of state development agreements. The inequities that exist in international water law are rooted in the historical doctrine of sovereignty which has evolved to subordinate Indigenous peoples’ interests to state interests. Indigenous perspectives regarding sovereignty provide a counter-point to the dominant legal discourse and weave an alternate narrative that challenges the myth of objectivity and neutrality that surrounds the doctrine of sovereignty and international law generally. Once we recognize that sovereignty is a social construct, we can recognize our collective ability to reconstruct international laws in a manner that transcends the sovereign discourse and recognizes the rights of Indigenous peoples. Endorsement of the United Nations Declaration on the Rights of Indigenous Peoples (UNDRIP) is indicative of states’ commitment to recognize Indigenous peoples’ rights throughout the international legal system. This thesis concludes by offering a proposal for reconstructing transboundary water law through a return to ethics and coalition building. Future reform should be directed towards (a) articulating an international water ethic with the critical engagement of Indigenous peoples; and (b) ensuring that river basin organizations are established on every transboundary river in a manner consistent with this shared international water ethic.
Volatilization and Partitioning of Residual Electronic Cigarette Emissions to Particulate Matter
Creators: name: Colby, Henry J.
name: Katz, Erin F.
name: DeCarlo, Peter F.
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Biochemistry
subject: Microbiology
subject: FOS: Biological sciences
subject: Pharmacology
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: 69999 Biological Sciences not elsewhere classified
subject: Science Policy

description: The growing prevalence of electronic cigarettes (e-cigs) prompts investigation of their impact on indoor air quality. While the investigation of residual cigarette smoke, also known as third-hand smoke (THS), has been increasing, there is minimal literature on similar residue from e-cig emissions. Lab generated ammonium sulfate aerosol was introduced into a stainless-steel chamber which previously contained JUUL electronic cigarette vape. Aerosol composition was monitored using a high-resolution aerosol mass spectrometer. This was performed in the same chamber 3 times over 5 days. Species from electronic cigarette residue (nicotine and vegetable glycerin) were found to partition to particles with decreasing concentration over the multiple experiments while maintaining a consistent chemical signature. This signature matches closely to that of the primary electronic cigarette vape with notable exclusions of propylene glycol, benzoic acid, and cadmium. Electronic cigarette vape can deposit onto surfaces and act as a long-term source of gas phase nicotine which can concentrate on aerosols and increase human exposure. The chemical processing of vape residue observed here is less substantial than has been previously presented for residual cigarette smoke. While our experiments were performed under controlled conditions, they highlight the importance of understanding indoor electronic cigarette use and unintended routes of exposure.
On the spectrum and support theory of a finite tensor category
Creators: name: Nakano, Daniel K.
name: Vashaw, Kent B.
name: Yakimov, Milen T.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Category Theory (math.CT)
subject: Quantum Algebra (math.QA)
subject: Rings and Algebras (math.RA)
subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: 18M05

description: Finite tensor categories (FTCs) $\bf T$ are important generalizations of the categories of finite dimensional modules of finite dimensional Hopf algebras, which play a key role in many areas of mathematics and mathematical physics. There are two fundamentally different support theories for them: a cohomological one and a universal one based on the noncommutative Balmer spectra of their stable (triangulated) categories $\underline{\bf T}$. In this paper we introduce the key notion of the categorical center $C^\bullet_{\underline{\bf T}}$ of the cohomology ring $R^\bullet_{\underline{\bf T}}$ of an FTC, $\bf T$. This enables us to put forward a complete and detailed program for determining the exact relationship between the two support theories, based on $C^\bullet_{\underline{\bf T}}$ of the cohomology ring $R^\bullet_{\underline{\bf T}}$ of an FTC, $\bf T$. More specifically, we construct a continuous map from the noncommutative Balmer spectrum of an FTC, $\bf T$, to the $\text{Proj}$ of the categorical center $C^\bullet_{\underline{\bf T}}$, and prove that this map is surjective under a weaker finite generation assumption for $\bf T$ than the one conjectured by Etingof-Ostrik. Under stronger assumptions, we prove that (i) the map is homeomorphism and (ii) the two-sided thick ideals of $\underline{\bf T}$ are classified by the specialization closed subsets of $\text{Proj} C^\bullet_{\underline{\bf T}}$. We conjecture that both results hold for all FTCs. Many examples are presented that demonstrate how in important cases $C^\bullet_{\underline{\bf T}}$ arises as a fixed point subring of $R^\bullet_{\underline{\bf T}}$ and how the two-sided thick ideals of $\underline{\bf T}$ are determined in a uniform fashion. The majority of our results are proved in the greater generality of monoidal triangulated categories.
description: Appendix B has been revised from the prior version after considering comments from Greg Stevenson
Dynamical Dark Matter: II. An Explicit Model
Creators: name: Dienes, Keith R.
name: Thomas, Brooks
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In a recent paper (arXiv:1106.4546), we introduced "dynamical dark matter," a new framework for dark-matter physics, and outlined its underlying theoretical principles and phenomenological possibilities. Unlike most traditional approaches to the dark-matter problem which hypothesize the existence of one or more stable dark-matter particles, our dynamical dark-matter framework is characterized by the fact that the requirement of stability is replaced by a delicate balancing between cosmological abundances and lifetimes across a vast ensemble of individual dark-matter components. This setup therefore collectively produces a time-varying cosmological dark-matter abundance, and the different dark-matter components can interact and decay throughout the current epoch. While the goal of our previous paper was to introduce the broad theoretical aspects of this framework, the purpose of the current paper is to provide an explicit model of dynamical dark matter and demonstrate that this model satisfies all collider, astrophysical, and cosmological constraints. The results of this paper therefore constitute an "existence proof" of the phenomenological viability of our overall dynamical dark-matter framework, and demonstrate that dynamical dark matter is indeed a viable alternative to the traditional paradigm of dark-matter physics. Dynamical dark matter must therefore be considered alongside other approaches to the dark-matter problem, particularly in scenarios involving large extra dimensions or string theory in which there exist large numbers of particles which are neutral under Standard-Model symmetries.
description: 45 pages, LaTeX, 10 figures. Replaced to match published version
Factors influencing ambient particulate matter in Delhi, India: Insights from machine learning
Creators: name: Patel, Kanan
name: Bhandari, Sahil
name: Gani, Shahzad
name: Kumar, Purushottam
name: Baig, Nisar
name: Habib, Gazala
name: Apte, Joshua
name: Ruiz, Lea Hildebrandt
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Space Science
subject: Biotechnology
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Ecology
subject: FOS: Biological sciences

description: Concentrations of ambient particulate matter (PM) depend on various factors including emissions of primary pollutants, meteorology and chemical transformations. New Delhi, India is the most polluted megacity in the world and routinely experiences extreme pollution episodes. As part of the Delhi Aerosol Supersite study, we measured online continuous PM1 (particulate matter of size less than 1 μm) concentrations and composition for over five years starting January 2017, using an Aerosol Chemical Speciation Monitor (ACSM). Here, we describe the development and application of machine learning models using random forest regression to estimate the concentrations, composition, sources and dynamics of PM in Delhi. These models estimate PM1 species concentrations based on meteorological parameters including ambient temperature, relative humidity, planetary boundary layer height, wind speed, wind direction, precipitation, agricultural burning fire counts, solar radiation and cloud cover. We used hour of day, day of week and month of year as proxies for time-dependent emissions (e.g., emissions from traffic during rush hours). We demonstrate the applicability of these models to capture temporal variability of the PM1 species, to understand the influence of individual factors via sensitivity analyses, and to separate impacts of the COVID-19 lockdowns and associated activity restrictions from impacts of other factors. Our models provide new insights into the factors influencing ambient PM1 in New Delhi, India, demonstrating the power of machine learning models in atmospheric science applications. Copyright © 2023 American Association for Aerosol Research
QCD quark condensate in external magnetic fields
Creators: name: Bali, G. S.
name: Bruckmann, F.
name: Endrodi, G.
name: Fodor, Z.
name: Katz, S. D.
name: Schafer, A.
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present a comprehensive analysis of the light condensates in QCD with 1+1+1 sea quark flavors (with mass-degenerate light quarks of different electric charges) at zero and nonzero temperatures of up to 190 MeV and external magnetic fields B<1 GeV^2/e. We employ stout smeared staggered fermions with physical quark masses and extrapolate the results to the continuum limit. At low temperatures we confirm the magnetic catalysis scenario predicted by many model calculations, while around the crossover the condensate develops a complex dependence on the external magnetic field, resulting in a decrease of the transition temperature.
description: slight changes in the text, version accepted for publication in PRD. 5 pages, 5 figures
Autonomous Cleaning of Corrupted Scanned Documents - A Generative Modeling Approach
Creators: name: Dai, Zhenwen
name: Lücke, Jörg
Publisher: name: arXiv
Year: 2012
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: We study the task of cleaning scanned text documents that are strongly corrupted by dirt such as manual line strokes, spilled ink etc. We aim at autonomously removing dirt from a single letter-size page based only on the information the page contains. Our approach, therefore, has to learn character representations without supervision and requires a mechanism to distinguish learned representations from irregular patterns. To learn character representations, we use a probabilistic generative model parameterizing pattern features, feature variances, the features' planar arrangements, and pattern frequencies. The latent variables of the model describe pattern class, pattern position, and the presence or absence of individual pattern features. The model parameters are optimized using a novel variational EM approximation. After learning, the parameters represent, independently of their absolute position, planar feature arrangements and their variances. A quality measure defined based on the learned representation then allows for an autonomous discrimination between regular character patterns and the irregular patterns making up the dirt. The irregular patterns can thus be removed to clean the document. For a full Latin alphabet we found that a single page does not contain sufficiently many character examples. However, even if heavily corrupted by dirt, we show that a page containing a lower number of character types can efficiently and autonomously be cleaned solely based on the structural regularity of the characters it contains. In different examples using characters from different alphabets, we demonstrate generality of the approach and discuss its implications for future developments.
description: oral presentation and Google Student Travel Award; IEEE conference on Computer Vision and Pattern Recognition 2012
Impactor collection efficiencies can modify the uncertainty of multiply charged particles in optical extinction measurements
Creators: name: Mao, Chun-Ning
name: Asa-Awuku, Akua
name: Zangmeister, Christopher D.
name: Weaver, Jamie L.
name: Radney, James G.
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Biophysics
subject: Biochemistry
subject: Space Science
subject: 29999 Physical Sciences not elsewhere classified
subject: FOS: Physical sciences
subject: Cell Biology
subject: Biotechnology
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences

description: The complex distribution of particle charge states resulting from neutralization processes by radioactive or soft X-ray charge neutralizers is a well-documented problem in aerosol science. Here, we demonstrate that non-idealities in the collection efficiency of an impactor allows for the transmission of an unexpected population of multiply charged particles by a differential mobility analyzer that can bias optical measurements. The extinction cross sections (Cext) of ammonium sulfate particles were quantified using cavity ring-down spectroscopy and particle counting. Particles were selected by electrical mobility (i.e., a metric of particle size) using a differential mobility analyzer (DMA) or electrical mobility and mass selected by a tandem DMA and aerosol particle mass analyzer (APM), respectively, to elucidate multiple charging artifacts. Measured Cext exhibited statistically significant differences at particle sizes near the impactor cut point implying that these multiply charged particles should not be present and could not be confirmed by parallel size distribution measurements. Additionally, comparison of Cext with Mie theory demonstrates that misclassification of the multiply charged particles can give rise to numerically accurate results. To understand these observations, the collection efficiency (CE) of four impactors from similar electrostatic classifiers was investigated. From these measurements, it was determined that the nominal and actual diameters of the impactors differed by −0.5% (457 μm vs. (455 ± 1) μm, respectively (uncertainty is 1σ standard deviation)) but the average Stk50 (the Stokes number at the cut-point, D50) values differed by ≈ 23% (0.23 vs. 0.18 ± 0.01, respectively). The measured CE as a function of √Stk (a metric of particle aerodynamic size) exhibits a long tail toward higher √Stk values, allowing for transmission of the larger and multiply charged particles observed in the optical measurements. These measurements highlight the utility of using orthogonal, spectroscopic methods to quantify the presence of multiply charged particles. Copyright © 2023 American Association for Aerosol Research
Characterizing rings in terms of the extent of injectivity and projectivity of their modules
Creators: name: López-Permouth, Sergio R.
name: Simental, José E.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics

description: Given a ring R, we define its right i-profile (resp. right p-profile) to be the collection of injectivity domains (resp. projectivity domains) of its right R-modules. We study the lattice theoretic properties of these profiles and consider ways in which properties of the profiles may determine the structure of rings and viceversa. We show that the i-profile is isomorphic to an interval of the lattice of linear filters of right ideals of R, and is therefore modular and coatomic. In particular, we give a practical characterization of the i-profile of a right artinian ring. We show through an example that the p-profile is not necessarily a set, and also characterize the right p-profile of a right perfect ring. The study of rings in terms of their (i- or p-)profile was inspired by the study of rings with no (i- or p-) middle class, initiated in recent papers by Er, López-Permouth and Sökmez, and by Holston, López-Permouth and Orhan-Ertas. In this paper, we obtain further results about these rings and we also use our results to provide a characterization of a special class of QF-rings in which the injectivity and projectivity domains of any module coincide.
description: 19 pages, examples and propositions added. Title changed
FigureS1-S32, Table S4 and Section S1-S3 from Ecological dynamics of terrestrial and freshwater ecosystems across three mid-Phanerozoic mass extinctions from northwest China
Creators: name: Huang, Yuangeng
name: Chen, Zhong-Qiang
name: Roopnarine, Peter D.
name: Benton, Michael J.
name: Yang, Wan
name: Liu, Jun
name: Zhao, Laishi
name: Li, Zhenhua
name: Guo, Zhen
Publisher: name: The Royal Society
Year: 2021

description: Figure S1. Palaeogeography of Xinjiang and stratigraphy of the studied formations; Figure S2. Nonmetric multidimensional scaling ordinations of food-web; Figure S3. Rarefaction analysis of number of species against number of guilds; Figure S4. Diversity versus duration of time bin plot of the palaeocommunities in Xinjiang; Figure S5. Boxplots showing the variation range in PC1 and PC2 for species-level networks for each community. Community robustness decreases with elevating PC scores for both components; Figure S6-19. Plots showing secondary extinction versus primary perturbation for each of the 14 communities. Period of community is indicated by color, with red for Permian, purple for Triassic and blue for Jurassic; Figure S20-32. Plots showing secondary extinction versus primary perturbation for each of the 13 communities (randomly reduced species richness to 54). Period of community is indicated by color, with red for Permian, purple for Triassic and blue for Jurassic; Table S4. Mann-Whitney U tests results of the collapse thresholds between the original and the reduced species richness communities; Section S1. Sampling and uneven strata issues; Section S2. Principal components analysis (PCA); Section S3. Sources used to compile the database.
The role of natural killer T cells in X-linked lymphoproliferative disease
Creators: name: Chung, Brian Kai-Ho
Publisher: name: University of British Columbia
Year: 2012

description: X-linked lymphoproliferative disease (XLP) is a fatal immunodeficiency syndrome characterized by fulminant infectious mononucleosis (IM), uncontrolled lymphoproliferation and B cell malignancies following infection with the Epstein-Barr virus (EBV). In the majority of affected individuals, XLP is caused by mutations to the gene Src homology 2-domain 1A (SH2D1A), which encodes for signaling lymphocyte activation molecule-associated protein (SAP). Studies in SAP-deficient (SAP-/-) mice and in humans with XLP indicate that SAP is necessary for the normal function of several immune cell populations including natural killer (NK) cells, CD4⁺ helper T (TH) cells and CD8⁺ cytotoxic T lymphocytes (CTL). Surprisingly despite these immune cell defects, individuals with XLP appear immuno-competent against most pathogens and only develop disease upon exposure to EBV. Why EBV infection specifically triggers XLP in humans with defective SAP expression is not fully understood, however, we observed that SAP-/- mice and XLP subjects completely lack the immune subset of natural killer T (NKT) cells. Given that NKT cells are known to play an important role in controlling immune responses and that XLP subjects generate dysregulated immune responses following EBV infection, we hypothesized that NKT cells may directly control the proliferation of EBV-infected B cells. To test this hypothesis, we established an in vitro experimental system using human NKT cell lines and EBV-transformed tonsillar B cells. EBV transformation of naïve B cells into lymphoblastoid cell lines (LCL) resulted in the downregulation of the NKT cell antigen-presenting molecule CD1d and correlated with the inability of LCL to activate NKT cells, even in the presence of the superagonist α-galactosylceramide (αGalCer). By contrast, LCL with induced CD1d expression strongly activate NKT cell effector functions even in the absence of αGalCer. Collectively, these results demonstrate that NKT cells may be critical for controlling early EBV replication in B cells prior to CD1d downregulation and suggest that the absence of NKT cells may underlie the immune dysregulation in XLP subjects following EBV infection.
Impactor Collection Efficiencies Can Modify the Uncertainty of Multiply Charged Particles in Optical Extinction Measurements
Creators: name: Mao, Chun-Ning
name: Asa-Awuku, Akua
name: Zangmeister, Christopher D.
name: Weaver, Jamie L.
name: Radney, James G.
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Biophysics
subject: Biochemistry
subject: Space Science
subject: 29999 Physical Sciences not elsewhere classified
subject: FOS: Physical sciences
subject: Cell Biology
subject: Biotechnology
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences

description: The complex distribution of particle charge states resulting from neutralization processes by radioactive or soft X-ray charge neutralizers is a well-documented problem in aerosol science. Here, we demonstrate that non-idealities in the collection efficiency of an impactor allows for the transmission of an unexpected population of multiply charged particles by a differential mobility analyzer that can bias optical measurements. The extinction cross sections (Cext) of ammonium sulfate particles were quantified using cavity ring-down spectroscopy and particle counting. Particles were selected by electrical mobility (i.e., a metric of particle size) using a differential mobility analyzer (DMA) or electrical mobility and mass selected by a tandem DMA and aerosol particle mass analyzer (APM), respectively, to elucidate multiple charging artifacts. Measured Cext exhibited statistically significant differences at particle sizes near the impactor cut point implying that these multiply charged particles should not be present and could not be confirmed by parallel size distribution measurements. Additionally, comparison of Cext with Mie theory demonstrates that misclassification of the multiply charged particles can give rise to numerically accurate results. To understand these observations, the collection efficiency (CE) of four impactors from similar electrostatic classifiers was investigated. From these measurements, it was determined that the nominal and actual diameters of the impactors differed by -0.5% (457 μm versus (455 ± 1) μm, respectively (uncertainty is 1σ standard deviation)) but the average Stk50 (the Stokes number at the cut-point, D50) values differed by ≈ 23% (0.23 versus 0.18 ± 0.01, respectively). The measured CE as a function of √Stk (a metric of particle aerodynamic size) exhibits a long tail towards higher √Stk values, allowing for transmission of the larger and multiply charged particles observed in the optical measurements. These measurements highlight the utility of using orthogonal, spectroscopic methods to quantify the presence of multiply charged particles.
DeePN$^2$: A deep learning-based non-Newtonian hydrodynamic model
Creators: name: Fang, Lidong
name: Ge, Pei
name: Zhang, Lei
name: E, Weinan
name: Lei, Huan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Machine Learning (cs.LG)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: A long standing problem in the modeling of non-Newtonian hydrodynamics of polymeric flows is the availability of reliable and interpretable hydrodynamic models that faithfully encode the underlying micro-scale polymer dynamics. The main complication arises from the long polymer relaxation time, the complex molecular structure and heterogeneous interaction. DeePN$^2$, a deep learning-based non-Newtonian hydrodynamic model, has been proposed and has shown some success in systematically passing the micro-scale structural mechanics information to the macro-scale hydrodynamics for suspensions with simple polymer conformation and bond potential. The model retains a multi-scaled nature by mapping the polymer configurations into a set of symmetry-preserving macro-scale features. The extended constitutive laws for these macro-scale features can be directly learned from the kinetics of their micro-scale counterparts. In this paper, we develop DeePN$^2$ using more complex micro-structural models. We show that DeePN$^2$ can faithfully capture the broadly overlooked viscoelastic differences arising from the specific molecular structural mechanics without human intervention.
The Spectral Evolution of Convective Mixing White Dwarfs, the non-DA Gap, and White Dwarf Cosmochronology
Creators: name: Chen, Eugene Y.
name: Hansen, Brad M. S.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The spectral distribution of field white dwarfs shows a feature called the "non-DA gap". As defined by Bergeron et al., this is a temperature range (5100K--6100K) where relatively few non-DA stars are found, even though such stars are abundant on either side of the gap. It is usually viewed as an indication that a significant fraction of white dwarfs switch their atmospheric compositions back and forth between hydrogen-rich and helium-rich as they cool. In this paper, we present a Monte Carlo model of the Galactic disk white dwarf population, based on the spectral evolution model of Chen and Hansen. We find that the non-DA gap emerges naturally, even though our model only allows white dwarf atmospheres to evolve monotonically from hydrogen-rich to helium-rich through convective mixing. We conclude by discussing the effects of convective mixing on the white dwarf luminosity function and the use thereof for Cosmochronology.
description: Submitted to ApJL on Feb. 20, 2012. Accepted on May 15, 2012
Factors Influencing Ambient Particulate Matter in Delhi, India: Insights from Machine Learning
Creators: name: Patel, Kanan
name: Bhandari, Sahil
name: Gani, Shahzad
name: Kumar, Purushottam
name: Baig, Nisar
name: Habib, Gazala
name: Apte, Joshua
name: Ruiz, Lea Hildebrandt
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Space Science
subject: Biotechnology
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Ecology
subject: FOS: Biological sciences

description: Concentrations of ambient particulate matter (PM) depend on various factors including emissions of primary pollutants, meteorology and chemical transformations. New Delhi, India is the most polluted megacity in the world and routinely experiences extreme pollution episodes. As part of the Delhi Aerosol Supersite study, we measured online continuous PM1 (particulate matter of size less than 1µm) concentrations and composition for over five years starting January 2017, using an Aerosol Chemical Speciation Monitor (ACSM). Here, we describe the development and application of machine learning models using random forest regression to estimate the concentrations, composition, sources and dynamics of PM in Delhi. These models estimate PM1 species concentrations based on meteorological parameters including ambient temperature, relative humidity, planetary boundary layer height, wind speed, wind direction, precipitation, agricultural burning fire counts, solar radiation and cloud cover. We used hour of day, day of week and month of year as proxies for time-dependent emissions (e.g., emissions from traffic during rush hours). We demonstrate the applicability of these models to capture temporal variability of the PM1 species, to understand the influence of individual factors via sensitivity analyses, and to separate impacts of the COVID-19 lockdowns and associated activity restrictions from impacts of other factors. Our models provide new insights into the factors influencing ambient PM1 in New Delhi, India, demonstrating the power of machine learning models in atmospheric science applications.