bluuebunny/crossref_metadata_2025_split huggingface dataset:
Young Martian crater Gratteri and its secondary craters
Authors: Quantin Cathy , Popova Olga , Hartmann William K. , Werner Stephanie C. 
Published: June 2016

AbstractIn response to questions that have been raised about formation and effects of secondary craters on crater chronometry techniques, we studied properties of the secondary crater field around the young Martian primary ray crater Gratteri (diameter 7 km). The crater has an estimated age of 1 to 20 Myr, based on counts of small craters on flat interior surface, consistent with a likely age for a young crater its size (Hartmann et al., 2010). The following are among our findings: (1) We identify an unusual class of craters we call “rampart secondaries” which may suggest low‐angle impacts. (2) We measure size distributions of secondaries as a function of distance from Gratteri and used these data to reconstruct the mass‐velocity distribution of ejecta blasted out of Gratteri. Our data suggest that crater density in rays tends to peak around 120–230 km from Gratteri (roughly 20–30D) and reaches roughly 30–70 times the interray crater density. (3) Comparable total numbers of secondaries form inside rays and outside rays, and about half are concentrated in clusters in 2% of the area around Gratteri, with the others scattered over 98% of the area out to 400 km away from Gratteri. (4) In the old Noachian plains around Gratteri, secondaries have minimal effect on crater chronometry. These results, along with recently reported direct measurements of the rate of formation of 10 m to 20 m primaries on Mars (Daubar et al., 2013), tend to negate suggestions that the numbers and/or clustering of secondaries destroy the effectiveness of crater counting as a chronometric tool.
A new angle for probing field‐aligned irregularities with the Murchison Widefield Array
Authors: Loi Shyeh Tjing , Murphy Tara , Cairns Iver H. , Trott Cathryn M. , Hurley‐Walker Natasha , Feng Lu , Hancock Paul J. , Kaplan David L. 
Published: June 2016

AbstractElectron density irregularities in the ionosphere are known to be magnetically anisotropic, preferentially elongated along the lines of force. While many studies of their morphology have been undertaken by topside sounding and whistler measurements, it is only recently that detailed regional‐scale reconstructions have become possible, enabled by the advent of widefield radio telescopes. Here we present a new approach for visualizing and studying field‐aligned irregularities (FAIs), which involves transforming interferometric measurements of total electron content gradients onto a magnetic shell tangent plane. This removes the perspective distortion associated with the oblique viewing angle of the irregularities from the ground, facilitating the decomposition of dynamics along and across magnetic field lines. We apply this transformation to the data set of Loi et al. (2015a), obtained on 15 October 2013 by the Murchison Widefield Array (MWA) radio telescope and displaying prominent FAIs. We study these FAIs in the new reference frame, quantifying field‐aligned and field‐transverse behavior, examining time and altitude dependencies, and extending the analysis to FAIs on subarray scales. We show that the inclination of the plane can be derived solely from the data and verify that the best fit value is consistent with the known magnetic inclination. The ability of the model to concentrate the fluctuations along a single spatial direction may find practical application to future calibration strategies for widefield interferometry, by providing a compact representation of FAI‐induced distortions.
Actively heated high‐resolution fiber‐optic‐distributed temperature sensing to quantify streambed flow dynamics in zones of strong groundwater upwelling
Authors: Briggs Martin A. , Buckley Sean F. , Bagtzoglou Amvrossios C. , Werkema Dale D. , Lane John W. 
Published: June 2016

AbstractZones of strong groundwater upwelling to streams enhance thermal stability and moderate thermal extremes, which is particularly important to aquatic ecosystems in a warming climate. Passive thermal tracer methods used to quantify vertical upwelling rates rely on downward conduction of surface temperature signals. However, moderate to high groundwater flux rates (>−1.5 m d−1) restrict downward propagation of diurnal temperature signals, and therefore the applicability of several passive thermal methods. Active streambed heating from within high‐resolution fiber‐optic temperature sensors (A‐HRTS) has the potential to define multidimensional fluid‐flux patterns below the extinction depth of surface thermal signals, allowing better quantification and separation of local and regional groundwater discharge. To demonstrate this concept, nine A‐HRTS were emplaced vertically into the streambed in a grid with ∼0.40 m lateral spacing at a stream with strong upward vertical flux in Mashpee, Massachusetts, USA. Long‐term (8–9 h) heating events were performed to confirm the dominance of vertical flow to the 0.6 m depth, well below the extinction of ambient diurnal signals. To quantify vertical flux, short‐term heating events (28 min) were performed at each A‐HRTS, and heat‐pulse decay over vertical profiles was numerically modeled in radial two dimension (2‐D) using SUTRA. Modeled flux values are similar to those obtained with seepage meters, Darcy methods, and analytical modeling of shallow diurnal signals. We also observed repeatable differential heating patterns along the length of vertically oriented sensors that may indicate sediment layering and hyporheic exchange superimposed on regional groundwater discharge.
Profiling float‐based observations of net respiration beneath the mixed layer
Authors: Hennon Tyler D. , Riser Stephen C. , Mecking Sabine 
Published: June 2016

AbstractWe employ profiling floats with dissolved oxygen sensors to observe in situ temporal oxygen evolution below the mixed layer, allowing us to characterize net respiration of organic carbon in eight distinct regions over the globe. Export and export efficiency are generally high in locations with strong seasonal variability and low in locations of weak seasonality. Vertically integrated respiration is weakly, yet significantly, correlated with remote observations of chlorophyll, net primary production, and planktonic community size structure. These correlations suggest that regimes of high net primary production and large phytoplankton fuel elevated respiration at depth. Several regions of float‐based observations intersect with sites of other detailed observations (e.g., Hawaii and Sargasso Sea), which allows us to compare our results to independent studies. We find that there is good agreement among export production estimates at highly seasonal locations, and that float‐based observations may be biased low at weakly seasonal locations. We posit that the reason for the low‐latitude discrepancy is the relative steady state of oxygen concentration caused by weak seasonality and shallow wintertime mixed layer depths.
Multispacecraft analysis of dipolarization fronts and associated whistler wave emissions using MMS data
Authors: Breuillard H. , Le Contel O. , Retino A. , Chasapis A. , Chust T. , Mirioni L. , Graham D. B. , Wilder F. D. , Cohen I. , Vaivads A. , Khotyaintsev Yu. V. , Lindqvist P.‐A. , Marklund G. T. , Burch J. L. , Torbert R. B. , Ergun R. E. , Goodrich K. A. , Macri J. , Needell J. , Chutter M. , Rau D. , Dors I. , Russell C. T. , Magnes W. , Strangeway R. J. , Bromund K. R. , Plaschke F. , Fischer D. , Leinweber H. K. , Anderson B. J. , Le G. , Slavin J. A. , Kepko E. L. , Baumjohann W. , Mauk B. , Fuselier S. A. , Nakamura R. 
Published: June 2016

AbstractDipolarization fronts (DFs), embedded in bursty bulk flows, play a crucial role in Earth's plasma sheet dynamics because the energy input from the solar wind is partly dissipated in their vicinity. This dissipation is in the form of strong low‐frequency waves that can heat and accelerate energetic electrons up to the high‐latitude plasma sheet. However, the dynamics of DF propagation and associated low‐frequency waves in the magnetotail are still under debate due to instrumental limitations and spacecraft separation distances. In May 2015 the Magnetospheric Multiscale (MMS) mission was in a string‐of‐pearls configuration with an average intersatellite distance of 160 km, which allows us to study in detail the microphysics of DFs. Thus, in this letter we employ MMS data to investigate the properties of dipolarization fronts propagating earthward and associated whistler mode wave emissions. We show that the spatial dynamics of DFs are below the ion gyroradius scale in this region (∼500 km), which can modify the dynamics of ions in the vicinity of the DF (e.g., making their motion nonadiabatic). We also show that whistler wave dynamics have a temporal scale of the order of the ion gyroperiod (a few seconds), indicating that the perpendicular temperature anisotropy can vary on such time scales.
Electron energization and mixing observed by MMS in the vicinity of an electron diffusion region during magnetopause reconnection
Authors: Chen Li‐Jen , Hesse Michael , Wang Shan , Gershman Daniel , Ergun Robert , Pollock Craig , Torbert Roy , Bessho Naoki , Daughton William , Dorelli John , Giles Barbara , Strangeway Robert , Russell Christopher , Khotyaintsev Yuri , Burch Jim , Moore Thomas , Lavraud Benoit , Phan Tai , Avanov Levon 
Published: June 2016

AbstractMeasurements from the Magnetospheric Multiscale (MMS) mission are reported to show distinct features of electron energization and mixing in the diffusion region of the terrestrial magnetopause reconnection. At the ion jet and magnetic field reversals, distribution functions exhibiting signatures of accelerated meandering electrons are observed at an electron out‐of‐plane flow peak. The meandering signatures manifested as triangular and crescent structures are established features of the electron diffusion region (EDR). Effects of meandering electrons on the electric field normal to the reconnection layer are detected. Parallel acceleration and mixing of the inflowing electrons with exhaust electrons shape the exhaust flow pattern. In the EDR vicinity, the measured distribution functions indicate that locally, the electron energization and mixing physics is captured by two‐dimensional reconnection, yet to account for the simultaneous four‐point measurements, translational invariant in the third dimension must be violated on the ion‐skin‐depth scale.
Compressional residual stress in Bastogne boudins revealed by synchrotron X‐ray microdiffraction
Authors: Chen Kai , Kunz Martin , Li Yao , Zepeda‐Alarcon Eloisa , Sintubin Manuel , Wenk Hans‐Rudolf 
Published: June 2016

AbstractLattice distortions in crystals can be mapped at the micron scale using synchrotron X‐ray Laue microdiffraction (μXRD). From lattice distortions the shape and orientation of the elastic strain tensor can be derived and interpreted in terms of residual stress. Here we apply the new method to vein quartz from the original boudinage locality at Bastogne, Belgium. A long‐standing debate surrounds the kinematics of the Bastogne boudins. The μXRD measurements reveal a shortening residual elastic strain, perpendicular to the vein wall, corroborating the model that the Bastogne boudins formed by layer‐parallel shortening and not by layer‐parallel extension, as is in the geological community generally inferred by the process of boudinage.
Experimental evidence supporting the insensitivity of cloud droplet formation to the mass accommodation coefficient for condensation of water vapor to liquid water
Authors: Langridge Justin M. , Richardson Mathews S. , Lack Daniel A. , Murphy Daniel M. 
Published: June 2016

AbstractThe mass accommodation coefficient for uptake of water vapor to liquid water, αM, has been constrained using photoacoustic measurements of aqueous absorbing aerosol. Measurements performed over a range of relative humidities and pressures were compared to detailed model calculations treating coupled heat and mass transfer occurring during photoacoustic laser heating cycles. The strengths and weaknesses of this technique are very different to those for droplet growth/evaporation experiments that have typically been applied to these measurements, making this a useful complement to existing studies. Our measurements provide robust evidence that αM is greater than 0.1 for all humidities tested and greater than 0.3 for data obtained at relative humidities greater than 88% where the aerosol surface was most like pure water. These values of αM are above the threshold at which kinetic limitations are expected to impact the activation and growth of aerosol particles in warm cloud formation.
The proton and electron radiation belts at geosynchronous orbit: Statistics and behavior during high‐speed stream‐driven storms
Authors: Borovsky Joseph E. , Cayton Thomas E. , Denton Michael H. , Belian Richard D. , Christensen Roderick A. , Ingraham J. Charles 
Published: June 2016

AbstractThe outer proton radiation belt (OPRB) and outer electron radiation belt (OERB) at geosynchronous orbit are investigated using a reanalysis of the LANL CPA (Charged Particle Analyzer) 8‐satellite 2‐solar cycle energetic particle data set from 1976 to 1995. Statistics of the OPRB and the OERB are calculated, including local time and solar cycle trends. The number density of the OPRB is about 10 times higher than the OERB, but the 1 MeV proton flux is about 1000 times less than the 1 MeV electron flux because the proton energy spectrum is softer than the electron spectrum. Using a collection of 94 high‐speed stream‐driven storms in 1976–1995, the storm time evolutions of the OPRB and OERB are studied via superposed epoch analysis. The evolution of the OERB shows the familiar sequence (1) prestorm decay of density and flux, (2) early‐storm dropout of density and flux, (3) sudden recovery of density, and (4) steady storm time heating to high fluxes. The evolution of the OPRB shows a sudden enhancement of density and flux early in the storm. The absence of a proton dropout when there is an electron dropout is noted. The sudden recovery of the density of the OERB and the sudden density enhancement of the OPRB are both associated with the occurrence of a substorm during the early stage of the storm when the superdense plasma sheet produces a “strong stretching phase” of the storm. These storm time substorms are seen to inject electrons to 1 MeV and protons to beyond 1 MeV into geosynchronous orbit, directly producing a suddenly enhanced radiation belt population.
Contamination in electron observations of the silicon detector on board Cluster/RAPID/IES instrument in Earth's radiation belts and ring current
Authors: Kronberg E. A. , Rashev M. V. , Daly P. W. , Shprits Y. Y. , Turner D. L. , Drozdov A. , Dobynde M. , Kellerman A. C. , Fritz T. A. , Pierrard V. , Borremans K. , Klecker B. , Friedel R. 
Published: June 2016

AbstractSince more than 15 years, the Cluster mission passes through Earth's radiation belts at least once every 2 days for several hours, measuring the electron intensity at energies from 30 to 400 keV. These data have previously been considered not usable due to contamination caused by penetrating energetic particles (protons at >100 keV and electrons at >400 keV). In this study, we assess the level of distortion of energetic electron spectra from the Research with Adaptive Particle Imaging Detector (RAPID)/Imaging Electron Spectrometer (IES) detector, determining the efficiency of its shielding. We base our assessment on the analysis of experimental data and a radiation transport code (Geant4). In simulations, we use the incident particle energy distribution of the AE9/AP9 radiation belt models. We identify the Roederer L values, L⋆, and energy channels that should be used with caution: at 3≤L⋆≤4, all energy channels (40–400 keV) are contaminated by protons (≃230 to 630 keV and >600 MeV); at L⋆≃1 and 4–6, the energy channels at 95–400 keV are contaminated by high‐energy electrons (>400 keV). Comparison of the data with electron and proton observations from RBSP/MagEIS indicates that the subtraction of proton fluxes at energies ≃ 230–630 keV from the IES electron data adequately removes the proton contamination. We demonstrate the usefulness of the corrected data for scientific applications.
Community‐wide validation of geospace model local K‐index predictions to support model transition to operations
Authors: Glocer A. , Rastätter L. , Kuznetsova M. , Pulkkinen A. , Singer H. J. , Balch C. , Weimer D. , Welling D. , Wiltberger M. , Raeder J. , Weigel R. S. , McCollough J. , Wing S. 
Published: June 2016

AbstractWe present the latest result of a community‐wide space weather model validation effort coordinated among the Community Coordinated Modeling Center (CCMC), NOAA Space Weather Prediction Center (SWPC), model developers, and the broader science community. Validation of geospace models is a critical activity for both building confidence in the science results produced by the models and in assessing the suitability of the models for transition to operations. Indeed, a primary motivation of this work is supporting NOAA/SWPC's effort to select a model or models to be transitioned into operations. Our validation efforts focus on the ability of the models to reproduce a regional index of geomagnetic disturbance, the local K‐index. Our analysis includes six events representing a range of geomagnetic activity conditions and six geomagnetic observatories representing midlatitude and high‐latitude locations. Contingency tables, skill scores, and distribution metrics are used for the quantitative analysis of model performance. We consider model performance on an event‐by‐event basis, aggregated over events, at specific station locations, and separated into high‐latitude and midlatitude domains. A summary of results is presented in this report, and an online tool for detailed analysis is available at the CCMC.
Disagreement, Moral
Authors: Tersman Folke 
Published: June 2016

The discussion in which moral disagreement has received most attention is metaethical and concerns the objectivity of ethics. Consider a moral opinion, such as the view that it is morally wrong to eat meat. Could such an opinion be true? If so, could it be objectively true – that is, roughly, could it be true independently of whether anyone thinks that it is true? According to the position known as moral realism, the answer to both questions is yes. Moral realism is usually construed as the combination of two views. First, moral claims express beliefs about the way things are, states that purport to represent objective aspects of reality. Second, some of those beliefs are in fact true. It is often suggested that the fact that there is deep and widespread disagreement over moral issues is difficult to reconcile with this objectivist picture of ethics, and that the diversity is better accounted for by the competitors to realism.
Influence of Soluble Electrospun Co‐Polyethersulfone Veils on Dynamic Mechanical and Morphological Properties of Epoxy Composites: Effect of Polymer Molar Mass
Authors: Cicala Gianluca , Latteri Alberta , Mannino Salvatore , Ognibene Giulia , Blanco Ignazio 
Published: June 2016

AbstractElectrospun veils from copolyethersulfones (coPES) with a number‐average molar mass (Mn) of 9000 g/mol (coPES9k) and 20,000 g/mol (coPES20k) were prepared as soluble interlaminar veils for carbon fiber/epoxy composites. Dry carbon fabrics were covered with electrospun veils and then infused with an unmodified epoxy resin to prepare reinforced laminates. CoPES powder was predissolved in the unmodified epoxy to obtain an epoxy/coPES blend used for preimpregnation of laminates which were compared to the laminates obtained with resin infusion. The thermoplastic content varied from 10wt% to 20wt% for coPES9k and from 5wt% to 10wt% for coPES20k. Unreinforced samples with no carbon fabrics were also studied. The coPES9k veils showed full solubility and homogeneous morphology when added to the epoxy resin. Unreinforced samples, modified by coPES9k veils, showed only minor morphological differences compared to epoxy/coPES blends obtained from coPES9k powder predissolution. The glass transition temperatures for these samples displayed differences less than 10°C. Carbon‐reinforced samples obtained using the same route showed larger differences. The coPES20k veils showed undissolved fibers and inhomogeneous morphologies when blended with an epoxy in the unreinforced samples.
Ferrocenyl Quinone Methide–Thiol Adducts as New Antiproliferative Agents: Synthesis, Metabolic Formation from Ferrociphenols, and Oxidative Transformation
Authors: Wang Yong , Richard Marie‐Aude , Top Siden , Dansette Patrick M. , Pigeon Pascal , Vessières Anne , Mansuy Daniel , Jaouen Gérard 
Published: June 2016

AbstractFerrociphenols (FCs) and their oxidized, electrophilic quinone methide metabolites (FC‐QMs) are organometallic compounds related to tamoxifen that exhibit strong antiproliferative properties. To evaluate the reactivity of FC‐QMs toward cellular nucleophiles, we studied their reaction with selected thiols. A series of new compounds resulting from the addition of these nucleophiles, the FC‐SR adducts, were thus synthesized and completely characterized. Such conjugates are formed upon metabolism of FCs by liver microsomes in the presence of NADPH and thiols. Some of the FC‐SR adducts exhibit antiproliferative properties comparable to those of their FC precursors. Under oxidizing conditions they either revert to their FC‐QM precursors or transform into new quinone methides (QMs) containing the SR moiety, FC‐SR‐QM. These results provide interesting data about the reactivity and mechanism of antiproliferative effects of FCs, and also open the way to a new series of organometallic antitumor compounds.
Site‐Selective Tertiary Alkyl–Fluorine Bond Formation from α‐Bromoamides Using a Copper/CsF Catalyst System
Authors: Nishikata Takashi , Ishida Syo , Fujimoto Ryo 
Published: June 2016

AbstractA copper‐catalyzed site‐selective fluorination of α‐bromoamides possessing multiple reaction sites, such as primary and secondary alkyl−Br bonds, using inexpensive CsF is reported. Tertiary alkyl−F bonds, which are very difficult to synthesize, can be formed by this fluorination reaction with the aid of an amide group. Control experiments revealed that in situ generated CuF2 is a key fluorinating reagent that reacts with the tertiary alkyl radicals generated by the reaction between an α‐bromocarbonyl compound and a copper(I) salt.
Flocculation behavior of cationic pea starch prepared by the graft copolymerization of acrylamide for wastewater treatment
Authors: Zou Yongqiang , Li Shanshan , Wang Yuqi , Yuan Chenxi , Yuan Weijian , Zheng Lan , Han Xiaolong 
Published: June 2016

ABSTRACTTo improve the flocculation efficiency of coal mine wastewater treatment, we synthesized a cationic flocculant by grafting acrylamide (AM) onto pea starch, and we performed the characterization with elemental analysis, Fourier transform infrared spectrometry, scanning electron microscopy, thermogravimetric analysis, and NMR. The effects of the synthesis conditions were also investigated, and the optimal synthesis parameters of the cationic flocculant were obtained. The mass ratio between pea starch and AM was 0.5 with a reaction temperature of 65 °C. The dosages of ceric ammonium nitrate and 3‐chloro‐2‐hydroxypropyl‐trimethylammonium chloride were 0.02 and 0.11 mol/L, respectively. Application experiments for wastewater treatment were carried out consequently, and the optimal dosage of cationic pea starch was 40 mg/L within the pH range 6–8. Compared with other traditional flocculation products, the cationic pea starch showed the best flocculation behavior for coal mine wastewater. Therefore, the cationic pea‐starch‐grafted AM may be applicable as a novel flocculant in wastewater treatment and has already demonstrated outstanding features. It is bound to replace other traditional flocculants in the future. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43922.