bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical lithiation of silicon electrodes: neutron reflectometry and secondary ion mass spectrometry investigations
Authors: Jerliu Bujar , Dörrer Lars , Hüger Erwin , Seidlhofer Beatrix-Kamelia , Steitz Roland , Borchardt Günter , Schmidt Harald 
Published: August 2017

AbstractIn-situ neutron reflectometry and ex-situ secondary ion mass spectrometry in combination with electrochemical methods were used to study the lithiation of amorphous silicon electrodes. For that purpose specially designed closed three-electrode electrochemical cells with thin silicon films as the working electrode and lithium as counter and reference electrodes were used. The neutron reflectometry results obtained in-situ during galvanostatic cycling show that the incorporation, redistribution and removal of Li in amorphous silicon during a lithiation cycle can be monitored. It was possible to measure the volume modification during lithiation, which is found to be rather independent of cycle number, current density and film thickness and in good agreement with first-principles calculations as given in literature. Indications for an inhomogeneous lithiation mechanism were found by secondary ion mass spectrometry measurements. Lithium tracer diffusion experiments indicate that the diffusivities inside the lithiated region (D > 10−15 m2 s−1) are considerably higher than in pure amorphous silicon as known from literature. This suggests a kinetics based explanation for the occurrence of an inhomogeneous lithiation mechanism.
Application of the grey-based fuzzy logic approach for materials selection
Authors: Babu Jalumedi , James Ajith , Philip Jose , Chakraborty Shankar 
Published: August 2017

Abstract
Material selection is considered an important step in the design and manufacturing of a part/product. Wrong selection of material may cause poor quality, increase in cost, early failure of the product, or any combination of them. It may also create difficulties in the manufacturing process leading to increases in manufacturing time and cost. The general rule in design is to select materials based on their properties that match with the product requirements. Hence, decision making for material selection is a crucial process, and several mathematical tools and techniques have been presented in the literature to aid this process. Those techniques have their own advantages and limitations. This paper proposes the application of the grey-based fuzzy logic approach to solve three real time material selection problems. For all the examples, the first and the last ranks of materials derived using the adopted method and those obtained by past researchers are exactly the same. This indicates that when uncertainties are involved, grey-based fuzzy logic can be employed as an efficient tool for solving complex material selection problems.
Exporting a Prince, Ideas and Institutions to Greece, 1862–4: Mid–Victorian Perceptions of Britain's Stand and Mission in the World
Authors: Hionidis Pandeleimon 
Published: August 2017

The expulsion from Greece of King Otho in 1862 and the Greeks’ decision to offer the throne of their kingdom to Alfred, the second son of Queen Victoria, provided a good opportunity for commenting on national progress for the following two years. Through the description of the gloomy condition of Greece, all the errors and omissions that a state should avoid in its struggle for political stability and material improvement were exhibited. Moreover, British comments celebrated the ‘exemplary’, the principles of government, the material and the scientific advancement that had given Britain its world supremacy. On the whole, British confidence in the reforming power of economic progress remained strong enough to enable writers to believe in the abilities of the Greeks to advance in ‘modern civilization’. In a sense, the debate occasioned by the case of Greece was enlarged upon in the question of the elements of national strength. Within this wider perspective, commentary and judgmental pronouncements on other European nations facilitated the discovery and display of elements that could be widely accepted as constituent parts of British national identity and international success in the mid–Victorian era, such as free institutions, industrial progress and a ‘liberal character’.
Comparative transcriptomics indicate changes in cell wall organization and stress response in seedlings during spaceflight
Authors: Johnson Christina M. , Subramanian Aswati , Pattathil Sivakumar , Correll Melanie J. , Kiss John Z. 
Published: August 2017

PREMISE OF THE STUDY:Plants will play an important role in the future of space exploration as part of bioregenerative life support. Thus, it is important to understand the effects of microgravity and spaceflight on gene expression in plant development.METHODS:We analyzed the transcriptome of Arabidopsis thaliana using the Biological Research in Canisters (BRIC) hardware during Space Shuttle mission STS‐131. The bioinformatics methods used included RMA (robust multi‐array average), MAS5 (Microarray Suite 5.0), and PLIER (probe logarithmic intensity error estimation). Glycome profiling was used to analyze cell wall composition in the samples. In addition, our results were compared to those of two other groups using the same hardware on the same mission (BRIC‐16).KEY RESULTS:In our BRIC‐16 experiments, we noted expression changes in genes involved in hypoxia and heat shock responses, DNA repair, and cell wall structure between spaceflight samples compared to the ground controls. In addition, glycome profiling supported our expression analyses in that there was a difference in cell wall components between ground control and spaceflight‐grown plants. Comparing our studies to those of the other BRIC‐16 experiments demonstrated that, even with the same hardware and similar biological materials, differences in results in gene expression were found among these spaceflight experiments.CONCLUSIONS:A common theme from our BRIC‐16 space experiments and those of the other two groups was the downregulation of water stress response genes in spaceflight. In addition, all three studies found differential regulation of genes associated with cell wall remodeling and stress responses between spaceflight‐grown and ground control plants.
The Cosmic-Ray Ionization Rate in the Galactic Disk, as Determined from Observations of Molecular Ions
Authors: Neufeld David A. , Wolfire Mark G. 
Published: August 2017

Abstract
We have obtained estimates for the cosmic-ray ionization rate (CRIR) in the Galactic disk, using a detailed model for the physics and chemistry of diffuse interstellar gas clouds to interpret previously published measurements of the abundance of four molecular ions: ArH+, OH+,

, and

. For diffuse atomic clouds at Galactocentric distances in the range

, observations of ArH+, OH+, and

imply a mean primary CRIR of

per hydrogen atom, where

. Within diffuse molecular clouds observed toward stars in the solar neighborhood, measurements of

and H2 imply a primary CRIR of

per H atom, corresponding to a total ionization rate per H2 molecule of

in good accord with previous estimates. These estimates are also in good agreement with a rederivation, presented here, of the CRIR implied by recent observations of carbon and hydrogen radio recombination lines along the sight line to Cas A. Here, our best-fit estimate for the primary CRIR is

per H atom. Our results show marginal evidence that the CRIR in diffuse molecular clouds decreases with cloud extinction,

, with a best-fit dependence

for

.
APOGEE Chemical Abundances of the Sagittarius Dwarf Galaxy
Authors: Hasselquist Sten , Shetrone Matthew , Smith Verne , Holtzman Jon , McWilliam Andrew , Fernández-Trincado J. G. , Beers Timothy C. , Majewski Steven R. , Nidever David L. , Tang Baitian , Tissera Patricia B. , Alvar Emma Fernández , Allende Prieto Carlos , Almeida Andres , Anguiano Borja , Battaglia Giuseppina , Carigi Leticia , Delgado Inglada Gloria , Frinchaboy Peter , García-Hernández D. A. , Geisler Doug , Minniti Dante , Placco Vinicius M. , Schultheis Mathias , Sobeck Jennifer , Villanova Sandro 
Published: August 2017

Abstract
The Apache Point Observatory Galactic Evolution Experiment provides the opportunity of measuring elemental abundances for C, N, O, Na, Mg, Al, Si, P, K, Ca, V, Cr, Mn, Fe, Co, and Ni in vast numbers of stars. We analyze thechemical-abundance patterns of these elements for 158 red giant stars belonging to the Sagittarius dwarf galaxy (Sgr). This is the largest sample of Sgr stars with detailed chemical abundances, and it is the first time that C, N, P, K, V, Cr, Co, and Ni have been studied at high resolution in this galaxy. We find that the Sgr stars with [Fe/H] ≳ −0.8 are deficient in all elemental abundance ratios (expressed as [X/Fe]) relative to the Milky Way, suggesting that the Sgr stars observed today were formed from gas that was less enriched by Type II SNe than stars formed in the Milky Way. By examining the relative deficiencies of the hydrostatic (O, Na, Mg, and Al) and explosive (Si, P, K, and Mn) elements, our analysis supports the argument that previous generations of Sgr stars were formed with a top-light initial mass function, one lacking the most massive stars that would normally pollute the interstellar medium with the hydrostatic elements. We use a simple chemical-evolution model, flexCE, to further support our claim and conclude that recent stellar generations of Fornax and the Large Magellanic Cloud could also have formed according to a top-light initial mass function.
Observable Emission Features of Black Hole GRMHD Jets on Event Horizon Scales
Authors: Pu Hung-Yi , Wu Kinwah , Younsi Ziri , Asada Keiichi , Mizuno Yosuke , Nakamura Masanori 
Published: August 2017

Abstract
The general-relativistic magnetohydrodynamical (GRMHD) formulation for black hole-powered jets naturally gives rise to a stagnation surface, where inflows and outflows along magnetic field lines that thread the black hole event horizon originate. We derive a conservative formulation for the transport of energetic electrons, which are initially injected at the stagnation surface and subsequently transported along flow streamlines. With this formulation the energy spectra evolution of the electrons along the flow in the presence of radiative and adiabatic cooling is determined. For flows regulated by synchrotron radiative losses and adiabatic cooling, the effective radio emission region is found to be finite, and geometrically it is more extended along the jet central axis. Moreover, the emission from regions adjacent to the stagnation surface is expected to be the most luminous as this is where the freshly injected energetic electrons are concentrated. An observable stagnation surface is thus a strong prediction of the GRMHD jet model with the prescribed non-thermal electron injection. Future millimeter/submillimeter (mm/sub-mm) very-long-baseline interferometric observations of supermassive black hole candidates, such as the one at the center of M87, can verify this GRMHD jet model and its associated non-thermal electron injection mechanism.
NuSTAR Hard X-Ray Observations of the Energetic Millisecond Pulsars PSR B1821-24, PSR B1937+21, and PSR J0218+4232
Authors: Gotthelf E. V. , Bogdanov S. 
Published: August 2017

Abstract
We present Nuclear Spectroscopic Telescope Array (NuSTAR) hard X-ray timing and spectroscopy of the three exceptionally energetic rotation-powered millisecond pulsars PSRs B1821-24, B1937+21, and J0218+4232. By correcting for the frequency and phase drifts of the NuSTAR onboard clock, we are able to recover the intrinsic hard X-ray pulse profiles of all three pulsars with a resolution down to

. The substantial reduction of background emission relative to previous broadband X-ray observations allows us to detect for the first time pulsed emission up to ∼50 keV, ∼20 keV, and ∼25 keV for the three pulsars, respectively. We conduct phase-resolved spectroscopy in the 0.5–79 keV range for all three objects, obtaining the best measurements yet of the broadband spectral shape and high-energy pulsed emission to date. We find extensions of the same power-law continua seen at lower energies, with no conclusive evidence for a spectral turnover or break. Extrapolation of the X-ray power-law spectrum to higher energies reveals that a turnover in the 100 keV to 100 MeV range is required to accommodate the high-energy γ-ray emission observed with Fermi-LAT, similar to the spectral energy distribution observed for the Crab pulsar.
The 12C/13C Ratio in Sgr B2(N): Constraints for Galactic Chemical Evolution and Isotopic Chemistry
Authors: Halfen D. T. , Woolf N. J. , Ziurys L. M. 
Published: August 2017

Abstract
A study has been conducted of 12C/13C ratios in five complex molecules in the Galactic center. H2CS, CH3CCH, NH2CHO, CH2CHCN, and CH3CH2CN and their 13C-substituted species have been observed in numerous transitions at 1, 2, and 3 mm, acquired in a spectral-line survey of Sgr B2(N), conducted with the telescopes of the Arizona Radio Observatory (ARO). Between 22 and 54 individual, unblended lines for the 12C species and 2–54 for 13C-substituted analogs were modeled in a global radiative transfer analysis. All five molecules were found to consistently exhibit two velocity components near V
LSR ∼ 64 and 73 km s−1, with column densities ranging from N
tot ∼ 3 × 1014 − 4 × 1017 cm−2 and ∼2 × 1013 − 1 × 1017 cm−2 for the 12C and 13C species, respectively. Based on 14 different isotopic combinations, ratios were obtained in the range 12C/13C = 15 ± 5 to 33 ± 13, with an average value of 24 ± 7, based on comparison of column densities. These measurements better anchor the 12C/13C ratio at the Galactic center, and suggest a slightly revised isotope gradient of 12C/13C = 5.21(0.52) D
GC + 22.6(3.3). As indicated by the column densities, no preferential 13C enrichment was found on the differing carbon sites of CH3CCH, CH2CHCN, and CH3CH2CN. Because of the elevated temperatures in Sgr B2(N), 13C isotopic substitution is effectively “scrambled,” diminishing chemical fractionation effects. The resulting ratios thus reflect stellar nucleosynthesis and Galactic chemical evolution, as is likely the case for most warm clouds.
The Initial Mass Function in the Nearest Strong Lenses from SNELLS: Assessing the Consistency of Lensing, Dynamical, and Spectroscopic Constraints
Authors: Newman Andrew B. , Smith Russell J. , Conroy Charlie , Villaume Alexa , van Dokkum Pieter 
Published: August 2017

Abstract
We present new observations of the three nearest early-type galaxy (ETG) strong lenses discovered in the SINFONI Nearby Elliptical Lens Locator Survey (SNELLS). Based on their lensing masses, these ETGs were inferred to have a stellar initial mass function (IMF) consistent with that of the Milky Way, not the bottom-heavy IMF that has been reported as typical for high-σ ETGs based on lensing, dynamical, and stellar population synthesis techniques. We use these unique systems to test the consistency of IMF estimates derived from different methods. We first estimate the stellar M
*/L using lensing and stellar dynamics. We then fit high-quality optical spectra of the lenses using an updated version of the stellar population synthesis models developed by Conroy & van Dokkum. When examined individually, we find good agreement among these methods for one galaxy. The other two galaxies show 2–3σ tension with lensing estimates, depending on the dark matter contribution, when considering IMFs that extend to 0.08 M
⊙. Allowing a variable low-mass cutoff or a nonparametric form of the IMF reduces the tension among the IMF estimates to <2σ. There is moderate evidence for a reduced number of low-mass stars in the SNELLS spectra, but no such evidence in a composite spectrum of matched-σ ETGs drawn from the SDSS. Such variation in the form of the IMF at low stellar masses (m ≲ 0.3 M
⊙), if present, could reconcile lensing/dynamical and spectroscopic IMF estimates for the SNELLS lenses and account for their lighter M
*/L relative to the mean matched-σ ETG. We provide the spectra used in this study to facilitate future comparisons.
TMRT Observations of 26 Pulsars at 8.6 GHz
Authors: Zhao 赵汝 Ru-Shuang 双 , Wu 吴鑫 Xin-Ji 基 , Yan 闫 Zhen 振 , Shen 沈志 Zhi-Qiang 强 , Manchester R. N. , Qiao 乔国 Guo-Jun 俊 , Xu 徐仁 Ren-Xin 新 , Wu 吴亚 Ya-Jun 军 , Zhao 赵融 Rong-Bing 冰 , Li 李 Bin 斌 , Du 杜源 Yuan-Jie 杰 , Lee 李柯 Ke-Jia 伽 , Hao 郝龙 Long-Fei 飞 , Liu 刘庆 Qing-Hui 会 , Lu 卢吉 Ji-Guang 光 , Shang 尚伦 Lun-Hua 华 , Wang 王锦 Jin-Qing 清 , Wang 汪 Min 敏 , Yuan 袁 Jin 瑾 , Zhi 支启 Qi-Jun 军 , Zhong 仲伟 Wei-Ye 业 
Published: August 2017

Abstract
Integrated pulse profiles at 8.6 GHz obtained with the Shanghai Tian Ma Radio Telescope (TMRT) are presented for a sample of 26 pulsars. Mean flux densities and pulse width parameters of these pulsars are estimated. For 11 pulsars these are the first high-frequency observations and for a further four, our observations have a better signal-to-noise ratio than previous observations. For one (PSR J0742−2822), the 8.6 GHz profile differs from previously observed profiles. A comparison of 19 profiles with those at other frequencies shows that in nine cases, the separation between the outmost leading and trailing components decreases with frequency, which is roughly in agreement with radius-to-frequency mapping, whereas in the other 10 the separation is nearly constant. Different spectral indices of profile components lead to the variation of integrated pulse profile shapes with frequency. In seven pulsars with multi-component profiles, the spectral indices of the central components are steeper than those of the outer components. For the 12 pulsars with multi-component profiles in the high-frequency sample, we estimate the core width using Gaussian fitting and discuss the width-period relationship.
Detection of Extraplanar Diffuse Ionized Gas in M83*
Authors: Boettcher Erin , Gallagher III J. S. , Zweibel Ellen G. 
Published: August 2017

Abstract
We present the first kinematic study of extraplanar diffuse ionized gas (eDIG) in the nearby, face-on disk galaxy M83 using optical emission-line spectroscopy from the Robert Stobie Spectrograph on the Southern African Large Telescope. We use a Markov Chain Monte Carlo method to decompose the [N ii]

6548, 6583, Hα, and [S ii]

6717, 6731 emission lines into H ii region and diffuse ionized gas emission. Extraplanar, diffuse gas is distinguished by its emission-line ratios ([N ii]λ6583/Hα

) and its rotational velocity lag with respect to the disk (

km s−1 in projection). With interesting implications for isotropy, the velocity dispersion of the diffuse gas,

km s−1, is a factor of a few higher in M83 than in the Milky Way and nearby, edge-on disk galaxies. The turbulent pressure gradient is sufficient to support the eDIG layer in dynamical equilibrium at an electron scale height of

kpc. However, this dynamical equilibrium model must be finely tuned to reproduce the rotational velocity lag. There is evidence of local bulk flows near star-forming regions in the disk, suggesting that the dynamical state of the gas may be intermediate between a dynamical equilibrium and a galactic fountain flow. As one of the first efforts to study eDIG kinematics in a face-on galaxy, this study demonstrates the feasibility of characterizing the radial distribution, bulk velocities, and vertical velocity dispersions in low-inclination systems.
Molecular Gas in Three z ∼ 7 Quasar Host Galaxies
Authors: Venemans Bram P. , Walter Fabian , Decarli Roberto , Ferkinhoff Carl , Weiß Axel , Findlay Joseph R. , McMahon Richard G. , Sutherland Will J. , Meijerink Rowin 
Published: August 2017

Abstract
We present ALMA band 3 observations of the CO(6–5), CO(7–6), and [C i] 369 μm emission lines in three of the highest-redshift quasar host galaxies at

. These measurements constitute the highest-redshift CO detections to date. The target quasars have previously been detected in [C ii] 158 μm emission and the underlying FIR dust continuum. We detect (spatially unresolved, at a resolution of >2″, or ≳14 kpc) CO emission in all three quasar hosts. In two sources, we detect the continuum emission around 400 μm (rest-frame), and in one source we detect [C i] at low significance. We derive molecular gas reservoirs of (1–3) × 1010

in the quasar hosts, i.e., approximately only 10 times the mass of their central supermassive black holes. The extrapolated [C ii]-to-CO(1–0) luminosity ratio is 2500–4200, consistent with measurements in galaxies at lower redshift. The detection of the [C i] line in one quasar host galaxy and the limit on the [C i] emission in the other two hosts enables a first characterization of the physical properties of the interstellar medium in z ∼ 7 quasar hosts. In the sources, the derived global CO/[C ii]/[C i] line ratios are consistent with expectations from photodissociation regions, but not X-ray-dominated regions. This suggest that quantities derived from the molecular gas and dust emission are related to ongoing star-formation activity in the quasar hosts, providing further evidence that the quasar hosts studied here harbor intense starbursts in addition to their active nucleus.
A Tale of Two Transients: GW 170104 and GRB 170105A
Authors: Bhalerao V. , Kasliwal M. M. , Bhattacharya D. , Corsi A. , Aarthy E. , Adams S. M. , Blagorodnova N. , Cantwell T. , Cenko S. B. , Fender R. , Frail D. , Itoh R. , Jencson J. , Kawai N. , Kong A. K. H. , Kupfer T. , Kutyrev A. , Mao J. , Mate S. , Mithun N. P. S. , Mooley K. , Perley D. A. , Perrott Y. C. , Quimby R. M. , Rao A. R. , Singer L. P. , Sharma V. , Titterington D. J. , Troja E. , Vadawale S. V. , Vibhute A. , Vedantham H. , Veilleux S. 
Published: August 2017

Abstract
We present multi-wavelength follow-up campaigns by the AstroSat CZTI and GROWTH collaborations in search of an electromagnetic counterpart to the gravitational wave event GW 170104. At the time of the GW 170104 trigger, the AstroSat CZTI field of view covered 50.3% of the sky localization. We do not detect any hard X-ray (>100 keV) signal at this time, and place an upper limit of

, for a 1 s timescale. Separately, the ATLAS survey reported a rapidly fading optical source dubbed ATLAS17aeu in the error circle of GW 170104. Our panchromatic investigation of ATLAS17aeu shows that it is the afterglow of an unrelated long, soft GRB 170105A, with only a fortuitous spatial coincidence with GW 170104. We then discuss the properties of this transient in the context of standard long GRB afterglow models.
Thermal Electrons in Gamma-Ray Burst Afterglows
Authors: Ressler Sean M. , Laskar Tanmoy 
Published: August 2017

Abstract
To date, nearly all multi-wavelength modeling of long-duration γ-ray bursts has ignored synchrotron radiation from the significant population of electrons expected to pass the shock without acceleration into a power-law distribution. We investigate the effect of including the contribution of thermal, non-accelerated electrons to synchrotron absorption and emission in the standard afterglow model, and show that these thermal electrons provide an additional source of opacity to synchrotron self-absorption, and yield an additional emission component at higher energies. The extra opacity results in an increase in the synchrotron self-absorption frequency by factors of 10–100 for fiducial parameters. The nature of the additional emission depends on the details of the thermal population, but is generally observed to yield a spectral peak in the optical brighter than radiation from the nonthermal population by similar factors a few seconds after the burst, remaining detectable at millimeter and radio frequencies several days later.