cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Rapid and sustained surface ocean acidification during the Paleocene-Eocene Thermal Maximum
Creators: name: Penman, Donald E.
name: Hoenisch, Baerbel
name: Zeebe, Richard E.
name: Thomas, Ellen
name: Zachos, James C.
Publisher: name: Columbia University
Year: 2014
Subjects: Paleocene Geologic Epoch
Carbon dioxide
Ocean acidification
Chemical oceanography
Paleontology

description: The Paleocene-Eocene Thermal Maximum (PETM) has been associated with the release of several thousands of petagrams of carbon (Pg C) as methane and/or carbon dioxide into the ocean-atmosphere system within ~10 kyr, on the basis of the co-occurrence of a carbon isotope excursion (CIE), widespread dissolution of deep sea carbonates, and global warming. In theory, this rapid carbon release should have severely acidified the surface ocean, though no geochemical evidence has yet been presented. Using boron-based proxies for surface ocean carbonate chemistry, we present the first observational evidence for a drop in the pH of surface and thermocline seawater during the PETM. Planktic foraminifers from a drill site in the North Pacific (Ocean Drilling Program Site 1209) show a ~0.8‰ decrease in boron isotopic composition (δ11B) at the onset of the event, along with a 30–40% reduction in shell B/Ca. Similar trends in δ11B are present in two lower-resolution records from the South Atlantic and Equatorial Pacific. These observations are consistent with significant, global acidification of the surface ocean lasting at least 70 kyr and requiring sustained carbon release. The anomalies in the B records are consistent with an initial surface pH drop of ~0.3 units, at the upper range of model-based estimates of acidification.
Built Environment Evaluation in Virtual Reality Environments—A Cognitive Neuroscience Approach
Creators: name: Hu, Ming
name: Roberts, Jennifer
Publisher: name: MDPI
Year: 2020
Subjects: built environment
data driven
virtual reality
electroencephalogram
emotion

description: To date, the predominant tools for the evaluation of built environment quality and impact have been surveys, scorecards, or verbal comments—approaches that rely upon user-reported responses. The goal of this research project is to develop, test, and validate a data-driven approach for built environment quality evaluation/validation based upon measurement of real-time emotional responses to simulated environments. This paper presents an experiment that was conducted by combining an immersive virtual environment (virtual reality) and electroencephalogram (EEG) as a tool to evaluate Pre and Post Purple Line development. More precisely, the objective was to (a) develop a data-driven approach for built environment quality evaluation and (b) understand the correlation between the built environment characters and emotional state. The preliminary validation of the proposed evaluation method identified discrepancies between traditional evaluation results and emotion response indications through EEG signals. The validation and findings have laid a foundation for further investigation of relations between people’s general cognitive and emotional responses in evaluating built environment quality and characters.
Numerical simulations of composite supernova remnants for small $σ$ pulsar wind nebulae
Creators: name: Vorster, M. J.
name: Ferreira, S. E. S.
name: de Jager, O. C.
name: Djannati-Ataï, A.
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Composite supernova remnants consist of a pulsar wind nebula located inside a shell-type remnant. The presence of a shell has implications on the evolution of the nebula, although the converse is generally not true. The purpose of this paper is two-fold. The first aim is to determine the effect of the pulsar's initial luminosity and spin-down rate, the supernova ejecta mass, and density of the interstellar medium on the evolution of a spherically-symmetric, composite supernova remnant expanding into a homogeneous medium. The second aim is to investigate the evolution of the magnetic field in the pulsar wind nebula when the the composite remnant expands into a non-uniform interstellar medium. The Euler conservation equations for inviscid flow, together with the magnetohydrodynamic induction law in the kinematic limit, are solved numerically for a number of scenarios where the ratio of magnetic to particle energy is $σ< 0.01$. The simulations in the first part of the paper is solved in a one-dimensional configuration. In the second part of the paper, the effect of an inhomogeneous medium on the evolution is studied using a two-dimensional, axis-symmetric configuration.
Asymptotic properties of CP violation in the Standard Model
Creators: name: Pérez, Hilario
name: Kielanowski, Piotr
name: W., S. Rebeca Juárez
name: Mora, Gerardo
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present the analysis of the renormalization based evolution of the CP-violation observables obtained from the $C$ matrix introduced by Jarlskog. We show that the observables $\vert\det C\vert$ and $\operatorname{Tr}C^{2}$ decrease very fast with the energy and their value is reduced at the Planck's scale by 5 and 3 orders of magnitude with respect to their low energy values. On the other hand the Jarlskog's CKM matrix rephasing invariant $J$ increases with energy and at the Planck's scale is 25 % larger than at low energy. The absolute value of the coefficient $a_{CP}\sim \det C/(\operatorname{Tr}C^{2})^{3/2}$ decreases with energy and at the Planck's scale it is 12 % smaller than at low energy. We also find that the pattern of the eigenvalues of the $C$ matrix is such that two eigenvalues almost cancel each other and their absolute values are much bigger than the absolute value of the third eigenvalue. The low rate of the CP-violation is a consequence of this pattern of the eigenvalues.
description: 8 pages, 9 figures
Comparative Efficacy of Common Active Ingredients in Organic Insecticides Against Difficult to Control Insect Pests
Creators: name: Dively, Galen P.
name: Patton, Terrence
name: Barranco, Lindsay
name: Kulhanek, Kelly
Publisher: name: MDPI
Year: 2020
Subjects: organic insecticide
control efficacy
spinosad
pyrethrin
azadirachtin

description: There exists a lack of control efficacy information to enable decision-making about which organic insecticide product works best for a given insect pest. Here, we summarize results of 153 field trials on the control efficacy of common active ingredients in organic insecticides against 12 groups of the most difficult to control insect pests. These trials evaluated primarily the organic products Entrust (spinosad), Azera (pyrethrin and azadirachtin), PyGanic (pyrethrin) and Neemix (azadirachtin), which reduced pest infestations by an overall 73.9%, 61.7%, 48.6% and 46.1% respectively, averaged across all trials. Entrust was the most effective control option for many insect pests, particularly providing >75% control of flea beetles, Colorado potato beetle, cabbageworms and alfalfa weevil, but was relatively ineffective against true bugs and aphids. Azera provided >75% control of green peach aphid, flea beetles, Japanese beetle, Mexican bean beetle, potato leafhopper and cabbageworms. PyGanic was less effective than Entrust and Azera but still provided >75% control of green peach aphid, flea beetles and potato leafhopper. The growth inhibition effects of azadirachtin in Neemix were particularly effective against larvae of Mexican bean beetle and Colorado potato beetle but was generally less effective in trials with insect infestations consisting mainly of adult stages. Those insect pests that were particularly difficult to control included thrips, stinkbugs, cucumber beetles and fruitworms. Several caveats pertaining to the application of the results are discussed.
Supplementary Information - COMMSENV-22-0653A
Creators: name: Khan, Muhammad Haider
Publisher: name: figshare
Year: 2022
Subjects: Chemical and thermal processes in energy and combustion
Electrochemical energy storage and conversion

description: This folder contains the supplementary files for the Communications Earth and Environment Article - An Integrated Framework of Open-Source Tools for designing and evaluating Green Hydrogen production opportunities.
 Details of File
 - Table S1 compares the proposed framework against currently available resources
 - Table S4 provides the site specific data collected for the Australian case study - including data on renewable energy potential, available resources (water, natural gas pipelines, electricity transmission/network, hydrogen storage and road/rail network) and potential end users. The raw data were then ranked and scored using the scoring matrix (included in the attached file) and the subsequent ranks were calculated and graphed as rose diagrams (included in the attached file)
Export and circulation of ice cavity water in Pine Island Bay, West Antarctica
Creators: name: Thurnherr, Andreas M.
name: Jacobs, S. S.
name: Dutrieux, Pierre
name: Giulivi, Claudia
Publisher: name: Columbia University
Year: 2014
Subjects: subject: Sea ice
subject: Geophysics
subject: FOS: Earth and related environmental sciences
subject: Ocean temperature
subject: Oceanography

description: Large sectors of the Antarctic ice sheet are vulnerable to increases in melting at the bases of fringing ice shelves, with melt rates depending on ocean temperatures and circulations in the sub-ice cavities. Here we analyze an oceanographic data set obtained in austral summer 2009 in Pine Island Bay, which is bounded in the east by the calving front of the Amundsen Sea's fast-moving Pine Island Ice Shelf. The upper-ocean velocity field in the ice-free bay was dominated by a 700 m deep and 50 km wide gyre circulating 1.5 Sv of water clockwise around the bay. Ice cavity water was observed in a surface-intensified and southward-intensified boundary current along the ice front, and in a small ice cove at the end of the southern shear margin of the ice shelf. Repeat measurements in the cove reveal persistent cavity water export of ≈ 0.25 Sv during 10 days of sampling. Vertical velocities in the cove above the ice draft were dominated by buoyancy-frequency oscillations with amplitudes of several cm/s but without significant net upwelling. In combination with the seawater properties, this observation indicates that much of the upwelling occurs within fractured ice near the cove, potentially contributing to weakening the ice shelf shear margin.
Supplementary Information - COMMSENV-22-0653A
Creators: name: Khan, Muhammad Haider
Publisher: name: figshare
Year: 2022

description: This folder contains the supplementary files for the Communications Earth and Environment Article - An Integrated Framework of Open-Source Tools for designing and evaluating Green Hydrogen production opportunities.
 Details of File
 - Table S1 compares the proposed framework against currently available resources
 - Table S4 provides the site specific data collected for the Australian case study - including data on renewable energy potential, available resources (water, natural gas pipelines, electricity transmission/network, hydrogen storage and road/rail network) and potential end users. The raw data were then ranked and scored using the scoring matrix (included in the attached file) and the subsequent ranks were calculated and graphed as rose diagrams (included in the attached file)
Design and Validation of a Method to Characterize Human Interaction Variability
Creators: name: Cage, Kailyn
name: Vaughn-Cooke, Monifa
name: Fuge, Mark
Publisher: name: MDPI
Year: 2020
Subjects: interaction variability
human factors
user experience
human variability
validation
functional mapping
user error
anthropometry
ergonomics

description: Human interactions are paramount to the user experience, satisfaction, and risk of user errors. For products, anthropometry has traditionally been used in product sizing. However, structured methods that accurately map static and dynamic capabilities (e.g., functional mapping) of musculoskeletal regions for the conceptualization and redesign of product applications and use cases are limited. The present work aims to introduce and validate the effectiveness of the Interaction Variability method, which maps product components and musculoskeletal regions to determine explicit design parameters through limiting designer variation in the classification of human interaction factors. This study enrolled 16 engineering students to evaluate two series of interactions for (1) water bottle and (2) sunglasses applications enabling method validity and designer consistency assessments. For each interaction series, subjects identified and characterized product applications, components, and human interaction factors. Primary interactions, product mapping, and application identification achieved consensus between ranges of 31.25% and 100.00%, with significance (p < 0.1) observed at consensus rates of ≥75.00%. Significant levels of consistency were observed amongst designers, for at least one measure in all phases except anthropometric mapping for the sunglasses application indicating method effectiveness. Interaction variability was introduced and validated in this work as a standardized approach to identify, define, and map human and product interactions, which may reduce unintended use cases and user errors, respectively, in consumer populations.
Spatially Varying Coefficient Model for Neuroimaging Data with Jump Discontinuities
Creators: name: Zhu, Hongtu
name: Fan, Jianqing
name: Kong, Linglong
Publisher: name: arXiv
Year: 2013
Subjects: subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: Motivated by recent work on studying massive imaging data in various neuroimaging studies, we propose a novel spatially varying coefficient model (SVCM) to spatially model the varying association between imaging measures in a three-dimensional (3D) volume (or 2D surface) with a set of covariates. Two key features of most neuorimaging data are the presence of multiple piecewise smooth regions with unknown edges and jumps and substantial spatial correlations. To specifically account for these two features, SVCM includes a measurement model with multiple varying coefficient functions, a jumping surface model for each varying coefficient function, and a functional principal component model. We develop a three-stage estimation procedure to simultaneously estimate the varying coefficient functions and the spatial correlations. The estimation procedure includes a fast multiscale adaptive estimation and testing procedure to independently estimate each varying coefficient function, while preserving its edges among different piecewise-smooth regions. We systematically investigate the asymptotic properties (e.g., consistency and asymptotic normality) of the multiscale adaptive parameter estimates. We also establish the uniform convergence rate of the estimated spatial covariance function and its associated eigenvalue and eigenfunctions. Our Monte Carlo simulation and real data analysis have confirmed the excellent performance of SVCM.
Holographic vacuum energy regularization and corrected entropy of de Sitter space
Creators: name: Jalalzadeh, S.
name: Moradpour, H.
name: Tebyanian, H.
Publisher: name: arXiv
Year: 2024
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We propose that the spectrum of the surface area of the apparent horizon (AH) of de Sitter (dS) spacetime leads to corrected temperature and entropy of the dS spacetime, offering new insights into its thermodynamic properties. This is done by employing the spectrum of the AH radius, acquired from the Wheeler--DeWitt (WDW) equation, together with the Stefan--Boltzmann law, the time-energy uncertainty relation, and the unified first law of thermodynamics.
description: 16 pages, 1 figure
Virtual Modeling of User Populations and Formative Design Parameters
Creators: name: Knisely, Benjamin M.
name: Vaughn-Cooke, Monifa
Publisher: name: MDPI
Year: 2020
Subjects: human variability
human performance
digital human modeling
heterogeneity
design validation

description: Human variability related to physical, cognitive, socio-demographic, and other factors can contribute to large differences in human performance. Quantifying population heterogeneity can be useful for designers wishing to evaluate design parameters such that a system design is robust to this variability. Comprehensively integrating human variability in the design process poses many challenges, such as limited access to a statistically representative population and limited data collection resources. This paper discusses two virtual population modeling approaches intended to be performed prior to in-person design validation studies to minimize these challenges by: (1) targeting recruitment of representative population strata and (2) reducing the candidate design parameters being validated in the target population. The first approach suggests the use of digital human models, virtual representations of humans that can simulate system interaction to eliminate candidate design parameters. The second approach suggests the use of existing human databases to identify relevant human characteristics for representative recruitment strata in subsequent studies. Two case studies are presented to demonstrate each approach, and the benefits and limitations of each are discussed. This paper demonstrates the benefit of modeling prior to conducting in-person human performance studies to minimize resource burden, which has significant implications on early design stages.
Searching for Black Holes in Space - the key role of X-ray observations
Creators: name: Pounds, Ken
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Although General Relativity had provided the physical basis of black holes, evidence for their existence had to await the Space Era when X-ray observations first directed the attention of astronomers to the unusual binary stars Cygnus X-1 and A0620-00. Subsequently, a number of faint Ariel 5 and Uhuru sources, mainly at high Galactic latitude, were found to lie close to bright Seyfert galaxies,suggesting the nuclear activity in AGN might also be driven by accretion in the strong gravity of a black hole. Detection of rapid X-ray variability with EXOSAT later confirmed that the accreting object in AGN was almost certainly a supermassive black hole.
description: 15 pages, 11 figures. To be published in Space Science Reviews and as hard cover in the Space Science Series of ISSI: The Physics of Accretion onto Black Holes (Springer Publisher)
Evidence for complete and partial surface renewal at an air-water interface
Creators: name: Atmane, M.
name: Jessup, A. T.
name: Asher, W. E.
name: Phadnis, K.
name: Zappa, Christopher J.
name: Loewen, M. R.
Publisher: name: Columbia University
Year: 2009
Subjects: subject: Ocean-atmosphere interaction
subject: Wind waves
subject: Thermal boundary layer
subject: Atmospheric chemistry
subject: Oceanography
subject: FOS: Earth and related environmental sciences

description: A wind-wave flume is used to determine the extent to which the thermal boundary layer (TBL) at a wind-forced air-water interface is completely renewed from below. We measure skin temperature, Tskin, radiometrically, temperature immediately below the TBL, Tsubskin, using a temperature profiler, and net heat flux using the gradient flux technique. The Tskin probability density function, p(Tskin), and surface renewal time scale, τ, were measured using passive and active infrared imaging techniques, respectively. We find that the mean percentile rank of Tsubskin in p(Tskin) is 99.90, implying that complete surface renewal occurs. This result suggests an alternative to radiometric measurement of Tskin through the simple combination of an infrared camera and an in situ temperature sensor. Comparison of the temperature difference across the TBL to the expected cooling implies that a significant portion of events only partially renew the TBL. This result should impact efforts to improve air-sea transfer models.
$S_3$ discrete group as a source of the quark mass and mixing pattern in $331$ models
Creators: name: Hernández, A. E. Cárcamo
name: Martinez, R.
name: Nisperuza, Jorge
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We propose a model based on the $SU(3)_{C}\otimes SU(3)_{L}\otimes U(1)_{X}$ gauge symmetry with an extra $S_{3}\otimes Z_{2}\otimes Z_{4}\otimes Z_{12}$ discrete group, which successfully accounts for the SM quark mass and mixing pattern. The observed hierarchy of the SM quark masses and quark mixing matrix elements arises from the $Z_{4}$ and $Z_{12}$ symmetries, which are broken at very high scale by the $SU(3)_{L}$ scalar singlets ($σ$,$ζ$) and $τ$, charged under these symmetries, respectively. The Cabbibo mixing arises from the down type quark sector whereas the up quark sector generates the remaining quark mixing angles. The obtained magnitudes of the CKM matrix elements, the CP violating phase and the Jarlskog invariant are in agreement with the experimental data.
description: 12 pages. Version published in European Physical Journal C
Unveiling the Impact of Sulfur Doping on Copper-Substituted Lead Apatite: A Theoretical Study
Creators: name: Wang, Ming-Long
name: Peng, Yin-Hui
name: Liao, Ji-Hai
name: Yang, Xiao-Bao
name: Yao, Yao
name: Zhao, Yu-Jun
Publisher: name: arXiv
Year: 2024
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Room-temperature superconductivity represents a significant scientific milestone, with the initial report of LK-99, a copper-substituted lead apatite $\mathrm{Pb}_{10-x}\mathrm{Cu}_{x}(\mathrm{PO}_{4})_{6}\mathrm{O}$, offering a potential breakthrough. However, other researchers have encountered numerous challenges in replicating the original experimental results. In recent studies, Wang et al. successfully observed signs of a possible superconducting phase, such as smaller resistance and stronger diamagnetism, upon doping S into the samples. This indicates that the introduction of S is of significant importance for achieving an appropriate structure. To further investigate the role of S, we have considered the $\mathrm{Pb}_{10-x}\mathrm{Cu}_{x}(\mathrm{PO}_{4})_{6}\mathrm{S}$, systematically discussing its thermodynamic stability, as well as the influence of S on the distribution, concentration, and electronic properties of Cu. We find that $\mathrm{Pb}_{10-x}\mathrm{Cu}_{x}(\mathrm{PO}_{4})_{6}\mathrm{S}$ maintains thermodynamic stability, with S primarily influencing the distribution of Cu. The critical element dictating the electronic characteristics of the material post-synthesis is Cu, while the impact of S on the electronic properties is relatively minor. Our work provides valuable insights into the synthesis of potential apatite based room-temperature superconductors and the role of S in facilitating Cu doping.
description: 8 pages, 4 figures
Study of the phase transition in polycrystalline (Ba_{0.90}Pb_{0.10})(Ti_{0.90}Sn_{0.10})O_3
Creators: name: Kajtoch, C.
name: Bąk, W.
name: Garbarz-Glos, B.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Polycrystalline sample of (Ba_{0.90}Pb_{0.10})(Ti_{0.90}Sn_{0.10})O_3 was obtained by means of a conventional ceramic technology. The dielectric measurements were performed depending on temperature and frequency of electric measuring field. The character of the phase transitions of (Ba_{0.90}Pb_{0.10})(Ti_{0.90}Sn_{0.10})O_3 ceramics strongly depends on the presence of Pb in the sample. The obtained results pointed out the diffused character of phase transition. The temperature dependence of the dielectric properties showed that the phase transition from the paraelectric phase to ferroelectric one takes place at the same temperature (T_{m}=367 K). It does not depend on the frequency of the measuring electric field. A change of the value of the parameter γtakes place in the paraelectric phase.
description: 5 pages, 6 figures
Measurement- and comparison-based sizes of Schrödinger cat states of light
Creators: name: Volkoff, T. J.
name: Whaley, K. B.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Quantum Physics (quant-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We extend several measurement-based definitions of effective "cat-size" to coherent state superpositions with branches composed of either single coherent states or tensor products of coherent states. These effective cat-size measures depend on determining the maximal quantum distinguishability of certain states associated with the superposition state: e.g., in one measure, the maximal distinguishability of the branches of the superposition is considered as in quantum binary decision theory; in another measure, the maximal distinguishability of the initial superposition and its image after a one-parameter evolution generated by a local Hermitian operator is of interest. The cat-size scaling with the number of modes and mode intensity (i.e., photon number) is compared to the scaling derived directly from the Wigner function of the superposition and to that estimated experimentally from decoherence. We also apply earlier comparison-based methods for determining macroscopic superposition size that require a reference GHZ state. The case of a hierarchical Schrödinger cat state with branches composed of smaller superpositions is also analyzed from a measurement-based perspective.
Two-particle multichannel systems in a finite volume with arbitrary spin
Creators: name: Briceno, Raul A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The quantization condition for two-particle systems with arbitrary number of two-body open coupled channels, spin, momentum, and masses in a finite volume with either periodic or twisted boundary conditions is presented. Although emphasis is placed in cubic volumes, the result holds for asymmetric volumes. The result is relativistic, holds for all momenta below the three- and four-particle thresholds, and is exact up to exponential volume corrections that are governed by L/r, where L is the spatial extent of the volume and r is the range of the interactions between the particles. For hadronic systems the range of the interaction is set by the inverse of the pion mass, m_pi, and as a result the formalism presented is suitable for m_pi L >> 1. The condition presented is in agreement with all previous studies of two-body systems in a finite volume. Implications of the formalism for the studies of multichannel baryon-baryon systems are discussed.
description: 12 pages, 2 figures, minor typos corrected, results remains unchanged, corrected some of the references
title: Urit mature; 1771
title: drama in scenam datum a discipulis classis infimae ... gymnasii Soc. Iesu Burghusii anno MDCCLXXI. menese Maio
titleType: Subtitle
Creators: name: (:Unav)
Publisher: name: Universitätsbibliothek der Ludwig-Maximilians-Universität München
Year: 2008

description: Programm
Rain impacts on CO2 exchange in the western equatorial Pacific Ocean
Creators: name: Turk, Daniela
name: Zappa, Christopher J.
name: Meinen, Christopher S.
name: Christian, James R.
name: Ho, David T.
name: Dickson, Andrew G.
name: McGillis, Wade R.
Publisher: name: Columbia University
Year: 2010
Subjects: subject: Rain and rainfall--Environmental aspects
subject: Carbon cycle (Biogeochemistry)
subject: Atmospheric carbon dioxide
subject: Oceanography
subject: FOS: Earth and related environmental sciences
subject: Atmospheric chemistry

description: The ocean plays a major role in the global carbon cycle through the atmosphere-ocean partitioning of atmospheric carbon dioxide. Rain alters the physics and carbon chemistry at the ocean surface to increase the amount of CO2 taken up by the ocean. This paper presents the results of a preliminary study wherein rain measurements in the western equatorial Pacific are used to determine the enhanced transfer, chemical dilution and deposition effects of rain on air-sea CO2 exchange. Including these processes, the western equatorial Pacific CO2 flux is modified from an ocean source of +0.019 mol CO2 m−2 yr−1 to an ocean sink of −0.078 mol CO2 m−2 yr−1. This new understanding of rain effects changes the ocean's role in the global carbon budget, particularly in regions with low winds and high precipitation.
Hysteretic phenomena in a 2DEG in quantum Hall effect regime studied in a transport experiment
Creators: name: Budantsev, M. V.
name: Pokhabov, D. A.
name: Pogosov, A. G.
name: Zhdanov, E. Yu.
name: Bakarov, A. K.
name: Toropov, A. I.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We investigated experimentally non-equilibrium state of a two-dimensional electron gas (2DEG) in the quantum Hall effect (QHE) regime, studying the hysteresis of magnetoresistance of a 2DEG with a constriction. The large amplitude of the hysteresis enabled us to make the consistent phenomenological description of the hysteresis. We studied the dependence on the magnetic field sweep prehistory (minor loop measurements), recovered the anhysteretic curve, and studied the time dependence of the magnetoresistance. We showed that the hysteresis of magnetoresistance of a 2DEG in the QHE regime has significant phenomenological similarities with the hysteresis of magnetization of ferromagnetic materials, showing multistability, jumps of relaxation, and having the anhysteretic curve. Nevertheless, we revealed the crucial difference, manifested itself in an unusual inverted (anti-coercive) behavior of the magnetoresistance hysteresis. The time relaxation of the hysteresis has fast and slow regimes, similar to that of non-equilibrium magnetization of a 2DEG in QHE regime pointing to their common origin. We studied the dependence of the hysteresis loop area on the lithographic width of the constriction and found the threshold value of width $\sim$1.35 $μ$m beyond which the hysteresis is not observed. This points to the edge nature of the non-equilibrium currents (NECs) and allows us to determine the width of the NECs area ($\sim$0.5 $μ$m). We suggest the qualitative picture of the observed hysteresis, based on non-equilibrium redistribution of the electrons among the Landau level states and assuming huge imbalance between the population of bulk and edge electronic states.
description: 8 pages, 6 figures. Submitted to Phys. Rev. B
Microbreaking and the enhancement of air-water transfer velocity
Creators: name: Zappa, Christopher J.
name: Asher, W. E.
name: Jessup, A. T.
name: Klinke, J.
name: Long, S. R.
Publisher: name: Columbia University
Year: 2004
Subjects: subject: Ocean-atmosphere interaction--Simulation methods
subject: Heat--Transmission
subject: Water waves--Research
subject: Oceanography
subject: FOS: Earth and related environmental sciences
subject: Hydrology

description: The role of microscale wave breaking in controlling the air-water transfer of heat and gas is investigated in a laboratory wind-wave tank. The local heat transfer velocity, kH, is measured using an active infrared technique and the tank-averaged gas transfer velocity, kG, is measured using conservative mass balances. Simultaneous, colocated infrared and wave slope imagery show that wave-related areas of thermal boundary layer disruption and renewal are the turbulent wakes of microscale breaking waves, or microbreakers. The fractional area coverage of microbreakers, AB, is found to be 0.1–0.4 in the wind speed range 4.2–9.3 m s−1 for cleaned and surfactant-influenced surfaces, and kH and kG are correlated with AB. The correlation of kH with AB is independent of fetch and the presence of surfactants, while that for kG with AB depends on surfactants. Additionally, AB is correlated with the mean square wave slope, 〈S2〉, which has shown promise as a correlate for kG in previous studies. The ratio of kH measured inside and outside the microbreaker wakes is 3.4, demonstrating that at these wind speeds, up to 75% of the transfer is the direct result of microbreaking. These results provide quantitative evidence that microbreaking is the dominant mechanism contributing to air-water heat and gas transfer at low to moderate wind speeds.
Gravitational lensing and frame dragging of light in the Kerr-Newman and the Kerr-Newman-(anti) de Sitter black hole spacetimes
Creators: name: Kraniotis, G. V.
Publisher: name: arXiv
Year: 2014
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The null geodesics that describe photon orbits in the spacetime of a rotating electrically charged black hole (Kerr-Newman) are solved exactly including the contribution from the cosmological constant. We derive elegant closed form solutions for relativistic observables such as the deflection angle and frame dragging effect that a light ray experiences in the gravitational fields (i) of a Kerr-Newman black hole and (ii) of a Kerr-Newman-de Sitter black hole. We then solve the more involved problem of treating a Kerr-Newman black hole as a gravitational lens, i.e. a KN black hole along with a static source of light and a static observer both located far away but otherwise at arbitrary positions in space. For this model, we derive the analytic solutions of the lens equations in terms of Appell and Lauricella hypergeometric functions and the Weierstraßmodular form. The exact solutions derived for null, spherical polar and non-polar orbits, are applied for the calculation of frame dragging for the orbit of a photon around the galactic centre, assuming that the latter is a Kerr-Newman black hole. We also apply the exact solution for the deflection angle of an equatorial light ray in the gravitational field of a Kerr-Newman black hole for the calculation of bending of light from the gravitational field of the galactic centre for various values of the Kerr parameter, electric charge and impact factor. In addition, we derive analytic expressions for the Maxwell tensor components for a Zero-Angular-Momentum-Observer (ZAMO) in the Kerr-Newman-de Sitter spacetime.
description: updated version conforms to published version in General Relativity and Gravitation. The final Publication is available at Springer via http://dx.doi.org/10.1007/s10714-014-1818-8
Scalar flux profile relationships over the open ocean
Creators: name: Edson, J. B.
name: Zappa, Christopher J.
name: Ware, J. A.
name: McGillis, Wade R.
name: Hare, J. E.
Publisher: name: Columbia University
Year: 2004
Subjects: subject: Boundary layer
subject: Oceanography--Mathematical models
subject: Oceanography
subject: FOS: Earth and related environmental sciences
subject: Hydrology

description: The most commonly used flux-profile relationships are based on Monin-Obukhov (MO) similarity theory. These flux-profile relationships are required in indirect methods such as the bulk aerodynamic, profile, and inertial dissipation methods to estimate the fluxes over the ocean. These relationships are almost exclusively derived from previous field experiments conducted over land. However, the use of overland measurements to infer surface fluxes over the ocean remains questionable, particularly close to the ocean surface where wave-induced forcing can affect the flow. This study investigates the flux profile relationships over the open ocean using measurements made during the 2000 Fluxes, Air-Sea Interaction, and Remote Sensing (FAIRS) and 2001 GasEx experiments. These experiments provide direct measurement of the atmospheric fluxes along with profiles of water vapor and temperature. The specific humidity data are used to determine parameterizations of the dimensionless gradients using functional forms of two commonly used relationships. The best fit to the Businger-Dyer relationship [Businger, 1988] is found using an empirical constant of aq = 13.4 ± 1.7. The best fit to a formulation that has the correct form in the limit of local free convection [e.g., Wyngaard, 1973] is found using aq = 29.8 ± 4.6. These values are in good agreement with the consensus values from previous overland experiments and the Coupled Ocean-Atmosphere Response Experiment (COARE) 3.0 bulk algorithm [Fairall et al., 2003]; e.g., the COARE algorithm uses empirical constants of 15 and 34.2 for the Businger-Dyer and convective forms, respectively. Although the flux measurements were made at a single elevation and local similarity scaling is applied, the good agreement implies that MO similarity is valid within the marine atmospheric surface layer above the wave boundary layer.
Higher Order Variational Integrators: a polynomial approach
Creators: name: Campos, Cédric M.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Numerical Analysis (math.NA)
subject: Mathematical Physics (math-ph)
subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: Primary 65P10, Secondary 65L06, 65K10, 49Mxx

description: We reconsider the variational derivation of symplectic partitioned Runge-Kutta schemes. Such type of variational integrators are of great importance since they integrate mechanical systems with high order accuracy while preserving the structural properties of these systems, like the symplectic form, the evolution of the momentum maps or the energy behaviour. Also they are easily applicable to optimal control problems based on mechanical systems as proposed in Ober-Blöbaum et al. [2011]. Following the same approach, we develop a family of variational integrators to which we refer as symplectic Galerkin schemes in contrast to symplectic partitioned Runge-Kutta. These two families of integrators are, in principle and by construction, different one from the other. Furthermore, the symplectic Galerkin family can as easily be applied in optimal control problems, for which Campos et al. [2012b] is a particular case.
description: 12 pages, 1 table, 23rd Congress on Differential Equations and Applications, CEDYA 2013
Effects of Protein Unfolding on Aggregation and Gelation in Lysozyme Solutions
Creators: name: Nikfarjam, Shakiba
name: Jouravleva, Elena V.
name: Anisimov, Mikhail A.
name: Woehl, Taylor J.
Publisher: name: MDPI
Year: 2020
Subjects: lysozyme
aggregation
gelation
protein folding/unfolding

description: In this work, we investigate the role of folding/unfolding equilibrium in protein aggregation and formation of a gel network. Near the neutral pH and at a low buffer ionic strength, the formation of the gel network around unfolding conditions prevents investigations of protein aggregation. In this study, by deploying the fact that in lysozyme solutions the time of folding/unfolding is much shorter than the characteristic time of gelation, we have prevented gelation by rapidly heating the solution up to the unfolding temperature (~80 °C) for a short time (~30 min.) followed by fast cooling to the room temperature. Dynamic light scattering measurements show that if the gelation is prevented, nanosized irreversible aggregates (about 10–15 nm radius) form over a time scale of 10 days. These small aggregates persist and aggregate further into larger aggregates over several weeks. If gelation is not prevented, the nanosized aggregates become the building blocks for the gel network and define its mesh length scale. These results support our previously published conclusion on the nature of mesoscopic aggregates commonly observed in solutions of lysozyme, namely that aggregates do not form from lysozyme monomers in their native folded state. Only with the emergence of a small fraction of unfolded proteins molecules will the aggregates start to appear and grow.
Is climate sensitivity related to dynamical sensitivity? A Southern Hemisphere perspective
Creators: name: Grise, Kevin M.
name: Polvani, Lorenzo M.
Publisher: name: Columbia University
Year: 2014
Subjects: Atmospheric carbon dioxide
Atmospheric models
Atmospheric circulation
Air masses
Greenhouse gases
Atmosphere
Meteorology
Climatic changes
Atmosphere, Upper

description: This study examines whether the spread in the climate sensitivity of Coupled Model Intercomparison Project Phase 5 (CMIP5) models also captures the spread in the Southern Hemisphere dynamical response to greenhouse gas forcing. Three metrics are proposed to quantify the “dynamical sensitivity” of the Southern Hemisphere: the poleward expansion of the Hadley circulation, the poleward expansion of the subtropical dry zone, and the poleward shift of the midlatitude jet. In the CMIP5 abrupt 4 × CO₂ integrations, the expansion of the Hadley circulation is well correlated with climate sensitivity in all seasons; in contrast, the shifts in the subtropical dry zone and midlatitude jet are significantly correlated with climate sensitivity only in summer and fall. In winter, those responses are more strongly linked to the control climatology in each model. Thus, a narrow focus on traditional climate sensitivity alone might miss out on important features of the atmospheric circulation's response to increasing greenhouse gases, particularly in the extratropics.
How does a magnetic trap work?
Creators: name: Pérez-Ríos, J.
name: Sanz, A. S.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Atomic Physics (physics.atom-ph)
subject: Chemical Physics (physics.chem-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Magnetic trapping is a cornerstone for modern ultracold physics and its applications (e.g., quantum information processing, quantum metrology, quantum optics, or high-resolution spectroscopies). Here a comprehensive analysis and discussion of the basic physics behind the most commonly used magnetic traps in Bose-Einstein condensation is presented. This analysis includes the quadrupole trap, the time-averaged orbiting potential trap, and the Ioffe-Pritchard trap. It is shown how the trapping conditions and efficiency of these devices can be determined from simple derivations based on classical electromagnetism, even though they operate on quantum objects.
description: 24 pages, 5 figures
Developing Sensor Proxies for “Chemical Cocktails” of Trace Metals in Urban Streams
Creators: name: Morel, Carol J.
name: Kaushal, Sujay S.
name: Tan, Maggie L.
name: Belt, Kenneth T.
Publisher: name: MDPI
Year: 2020
Subjects: nonpoint source pollution
total maximum daily loads
proxy
surrogate
restoration

description: Understanding transport mechanisms and temporal patterns in the context of metal concentrations in urban streams is important for developing best management practices and restoration strategies to improve water quality. In some cases, in-situ sensors can be used to estimate unknown concentrations of trace metals or to interpolate between sampling events. Continuous sensor data from the United States Geological Survey were analyzed to determine statistically significant relationships between lead, copper, zinc, cadmium, and mercury with turbidity, specific conductance, dissolved oxygen, and discharge for the Hickey Run, Watts Branch, and Rock Creek watersheds in the Washington, D.C. region. We observed a significant negative linear relationship between concentrations of Cu and dissolved oxygen at Rock Creek (p < 0.05). Sometimes, turbidity had significant positive linear relationships with Pb and Hg concentrations. There were negative or positive linear relationships between Pb, Cd, Zn, and Hg and specific conductance. There also appeared to be relationships between watershed areal fluxes of Pb, Cu, Zn, and Cd in streams with turbidity. Watershed monitoring approaches using continuous sensor data have the potential to characterize the frequency, magnitude, and composition of pulses in concentrations and loads of trace metals, which could improve the management and restoration of urban streams.
The Potential Skilling, Upskilling, and Reskilling Opportunities for the Migration and Mobility of Workers, with a Specific Focus on Gender Aspects of Workers in the Countries of Origin
Creators: name: Abdel Fattah, Dina
name: Micheal Botros, Jessica
name: Gaber, Nada
name: Boland, Colleen
Publisher: name: Global Strategy for Skills, Migration and Development (GS4S)
Year: 2024

description: This working paper is a part of the Horizon Europe project GS4S - Global Strategy for Skills, Migration and Development. The paper examines the intersection of skilling, reskilling, upskilling and migration in three countries of origin- Egypt, Bangladesh and Nigeria- offering a comparative analysis of their socio-economic contexts, policy landscapes and skilling initiatives. The analysis highlights commonalities across the countries, such as persistent skills mismatches, gender disparities and inequities in access to skilling programs especially in rural areas. Additionally, barriers including fragmented policies and limited data on labor market outcomes constrain the effectiveness of these existing initiatives. Each country presents unique insights: Bangladesh made significant progress in vocational training aligned with GCC country labor demand, albeit skills mismatches remain; Egypt’s strategic reliance on remittances highlight the significance of migration, yet issues hindering progress include lack of female labor force participation and insufficient coordination across skilling initiatives; Nigeria’s dynamic digital sector is promising to address global labor market needs, but infrastructure and policy fragmentation remain barriers. The paper concludes with actionable recommendations for policymakers, educational institutions, and development agencies. It advocates for aligning skilling programs with labor market needs, promoting inclusivity through gender-sensitive and regionally equitable policies, expanding legal migration pathways and adopting data-driven approaches to enhance program evaluation. Addressing the challenges, the countries of origin can better harness the potential of skilling and migration to support sustainable development, reduce inequalities and strengthen their global competitiveness.
Remote Sensing of Coconut Trees in Tonga Using Very High Spatial Resolution WorldView-3 Data
Creators: name: Vermote, Eric F.
name: Skakun, Sergii
name: Becker-Reshef, Inbal
name: Saito, Keiko
Publisher: name: MDPI
Year: 2020
Subjects: coconut tree
tree counting
satellite imagery
very high spatial resolution
WorldView-3
tree shadow
image processing

description: This paper presents a simple and efficient image processing method for estimating the number of coconut trees in the Tonga region using very high spatial resolution data (30 cm) in the blue, green, red and near infrared spectral bands acquired by the WorldView-3 sensor. The method is based on the detection of tree shadows and the further analysis to reject false detection using geometrical properties of the derived segments. The algorithm is evaluated by comparing coconut tree counts derived by an expert through photo-interpretation over 57 randomly distributed (4% sampling rate) segments of 200 m × 200 m over the Vaini region of the Tongatapu island. The number of detected trees agreed within 5% versus validation data. The proposed method was also evaluated over the whole Tonga archipelago by comparing satellite-derived estimates to the 2015 agricultural census data—the total tree counts for both Tonga and Tongatapu agreed within 3%.