bluuebunny/crossref_metadata_2025_split huggingface dataset:
Understanding the local structure of Eu3+- and Y3+-stabilized zirconia: insights from luminescence and X-ray absorption spectroscopic investigations
Authors: Eibl M. , Shaw S. , Prieur D. , Rossberg A. , Wilding M. C. , Hennig C. , Morris K. , Rothe J. , Stumpf T. , Huittinen N. 
Published: May 2020

AbstractThis study combines bulk structural and spectroscopic investigations of Eu3+- or Y3+/Eu3+ co-doped tetragonal and cubic zirconia polymorphs to gain an in-depth understanding of the solid solution formation process. Our bulk structural characterizations show that the dopant is homogenously distributed in the ZrO2 host structure resulting in an increase of the bulk symmetry with increasing dopant substitution (from 8 to 26 mol%). The local site symmetry around the Eu3+ dopant, however, determined with luminescence spectroscopy (TRLFS), remains low in all samples. Results obtained with X-ray pair distribution function and X-ray absorption spectroscopy show that the average coordination environment in the stabilized zirconia structures remains practically unchanged. Despite this very constant average dopant environment, site-selective TRLFS data show the presence of three nonequivalent Eu3+ environments in the ZrO2 solid structures. These Eu3+ environments are assumed to arise from Eu3+ incorporation at superficial sites, which increase in abundance as the size of the crystallites decrease, and incorporation on two bulk sites differing in the location of the oxygen vacancies with respect to the dopant cation.
Existence and properties of solutions for boundary value problems based on the nonlinear reactor dynamics
Authors: Orpel Aleksandra 
Published: May 2020

AbstractWe deal with the existence of positive solutions for the following class of nonlinear equation $$u^{\prime \prime }(t)+Au^{\prime }(t)+g(t,u(t),v(t))=0$$

u
″

(
t
)

+
A

u
′

(
t
)

+
g

(
t
,
u

(
t
)

,
v

(
t
)

)

=
0

a.e. in (0, 1), with boundary conditions $$u^{\prime }(0)=0$$

u
′

(
0
)

=
0

, $$u^{\prime }(1)+Au(1)=0$$

u
′

(
1
)

+
A
u

(
1
)

=
0

, where v is a functional parameter. The form of the problem is associated with the classical model described by Markus and Amundson. We show the existence of at least one positive solution of this problem and discuss its properties. Moreover we describe conditions that guarantee the continuous dependence of solution on parameter v also in the case of the lack of the uniqueness of a solution. The results are based on the clasical fixed point methods. Our approach allows us to consider both sub and superlinear nonlinearities which may be singular with respect to the first variable.
Magnetization of Bi2Sr2CaCu2O8+δ Micrometer Thin Ring and Its Depinning Line
Authors: Semenenko B. , Camargo B. C. , Setzer A. , Böhlmann W. , Kopelevich Y. , Esquinazi P. D. 
Published: May 2020

AbstractWe demonstrate a geometrical effect on the depinning line (DL) of the flux line lattice of the Bi2Sr2CaCu2O8+δ high-Tc superconductor (HTSC) micrometer ring. The DL shifts to notably lower temperatures in comparison with bulk crystals and thin flakes of the same sample. The shift is attributed to a decrease in the overall pinning potential due to a double size effect, namely (a) the ring thickness $\sim 1~\mu $
∼
1

μ
m being smaller than the pinning correlation length and (b) the increase in the effective London penetration depth of the vortices (Pearl vortices). The large shift of the DL to lower temperatures may influence the suitability of this HTSC for applications in microstrip antennas and THz emitters.
Enhancing the Electrical Conductivity of Electrolytic Tough Pitch Copper Rods Processed by Incremental Equal Channel Angular Pressing
Authors: Ciemiorek Marta , Pawliszak Łukasz , Chromiński Witold , Olejnik Lech , Lewandowska Małgorzata 
Published: May 2020

Abstract
Electrolytic tough pitch copper rods were processed by Incremental Equal Channel Angular Pressing and subjected to short-term annealing. Conductivity of 94 pct IACS without significant changes in the material’s microstructure and mechanical properties, up to 130 HV0.2, was achieved, which gives a very good ratio of electrical conductivity to strength in comparison with other processing methods. The proposed method offers a solution for manufacturing rods of significant sizes with good mechanical strength and electrical conductivity.
Charged Exciton Dissociation Energy in (Cd,Mn)Te Quantum Wells with Variable Disorder and Carrier Density
Authors: Łopion A. , Bogucki A. , Połczyńska K. E. , Pacuski W. , Golnik A. , Kazimierczuk T. , Kossacki P. 
Published: May 2020

AbstractWe report on the magneto-photoluminescence of (Cd,Mn)Te/(Cd,Mg)Te quantum wells excited by photons with varied energy. We observe that laser illumination modifies the carrier density and Coulomb disorder in the quantum wells. Three different regimes are analyzed, corresponding to low hole density with low disorder, low hole density with significant disorder, and high hole density. By using the diluted magnetic semiconductor as a quantum well material, we can induce the spin singlet–triplet transition of charged excitons in a magnetic field. This transition is then used as a tool to determine the charged exciton dissociation energy. With this approach, we find the same value for the dissociation energy in all the regimes of hole density and disorder. Our result is compared with the dissociation energy obtained from the PL splitting between the X and X$$^{\!\! +}$$

+

lines at zero field, which exhibits significantly greater variation.
Predictors of Successful First-Pass Thrombectomy with a Balloon Guide Catheter: Results of a Decision Tree Analysis
Authors: Velasco Gonzalez Aglaé , Görlich Dennis , Buerke Boris , Münnich Nico , Sauerland Cristina , Rusche Thilo , Faldum Andreas , Heindel Walter 
Published: May 2020

AbstractComplete recanalization after a single retrieval maneuver is an interventional goal in acute ischemic stroke and an independent factor for good clinical outcome. Anatomical biomarkers for predicting clot removal difficulties have not been comprehensively analyzed and await unused. We retrospectively evaluated 200 consecutive patients who suffered acute stroke and occlusion of the anterior circulation and were treated with mechanical thrombectomy through a balloon guide catheter (BGC). The primary objective was to evaluate the influence of carotid tortuosity and BGC positioning on the one-pass Modified Thrombolysis in Cerebral Infarction Scale (mTICI) 3 rate, and secondarily, the influence of communicating arteries on the angiographic results. After the first-pass mTICI 3, recanalization fell from 51 to 13%. The regression models and decision tree (supervised machine learning) results concurred: carotid tortuosity was the main constraint on efficacy, reducing the likelihood of mTICI 3 after one pass to 30%. BGC positioning was relevant only in carotid arteries without elongation: BGCs located in the distal internal carotid artery (ICA) had a 70% probability of complete recanalization after one pass, dropping to 43% if located in the proximal ICA. These findings demonstrate that first-pass mTICI 3 is influenced by anatomical and interventional factors capable of being anticipated, enabling the BGC technique to be adapted to patient’s anatomy to enhance effectivity.
What is the Value of Experimentation and Measurement?
Authors: Liu C. H. Bryan , Chamberlain Benjamin Paul , McCoy Emma J. 
Published: May 2020

AbstractExperimentation and Measurement (E&M) capabilities allow organizations to accurately assess the impact of new propositions and to experiment with many variants of existing products. However, until now, the question of measuring the measurer, or valuing the contribution of an E&M capability to organizational success has not been addressed. We tackle this problem by analyzing how, by decreasing estimation uncertainty, E&M platforms allow for better prioritization. We quantify this benefit in terms of expected relative improvement in the performance of all new propositions and provide guidance for how much an E&M capability is worth and when organizations should invest in one.
Anthropomorphism Indexes of the Kinematic Chain for Artificial Hands
Authors: Llop-Harillo Immaculada , Pérez-González Antonio , Andrés-Esperanza Javier 
Published: May 2020

AbstractAnthropomorphic hands have received increasing research interest in the fields of robotics and prosthetics. But it is not yet clear how to evaluate their anthropomorphism. Similarity in the kinematic chain is essential to achieve both functionality and cosmesis. A few previous works have addressed the definition of anthropomorphism indexes, although they have some limitations in its definition. In this study, three different anthropomorphism indexes have been defined to compare the kinematic chain of artificial hands with that of the human hand. These indexes are based on the comparison of: (1) the parameters of the kinematic chain (dimensions, type of joints, orientations and ranges of motion), (2) the reachable workspace, and (3) common grasping postures. Five artificial hands with different degrees of anthropomorphism have been compared using the three Anthropomorphism Indexes of the Kinematic Chain (AIKC). The results show a high correlation between the first and third AIKC for the hands compared. The second AIKC presents much lower values than the other two, although they are higher for hands that combine abduction/adduction and flexion/extension movements in the kinematic chain of each finger. These indexes can be useful during the initial stage of designing artificial hands or evaluating their anthropomorphism.
Magnetic Reconnection Inside a Flux Transfer Event‐Like Structure in Magnetopause Kelvin‐Helmholtz Waves
Authors: Kieokaew R. , Lavraud B. , Foullon C. , Toledo‐Redondo S. , Fargette N. , Hwang K.‐J. , Malakit K. , Ruffolo D. , Øieroset M. , Phan T.‐D. , Hasegawa H. , Fadanelli S. , Avanov L. , Burch J. , Gershman D. J. , Giles B. , Dorelli J. , Génot V. , Jacquey C. , Moore T. , Paterson W. , Pollock C. , Rager A. , Saito Y. , Sauvaud J.‐A. , Schiff C. , Vernisse Y. , Penou E. 
Published: May 2020

AbstractMagnetopause Kelvin‐Helmholtz (KH) waves are believed to mediate solar wind plasma transport via small‐scale mechanisms. Vortex‐induced reconnection (VIR) was predicted in simulations and recently observed using NASA's Magnetospheric Multiscale (MMS) mission data. Flux Transfer Events (FTEs) produced by VIR at multiple locations along the periphery of KH waves were also predicted in simulations, but detailed observations were still lacking. Here we report MMS observations of an FTE‐type structure in a KH wave trailing edge during KH activity on 5 May 2017 on the dawnside flank magnetopause. The structure is characterized by (1) bipolar magnetic BY variation with enhanced core field (BZ) and (2) enhanced total pressure with dominant magnetic pressure. The cross‐section size of the FTE is found to be consistent with vortex‐induced flux ropes predicted in the simulations. Unexpectedly, we observe an ion jet (VY); electron parallel heating, ion, and electron density enhancements; and other signatures that can be interpreted as a reconnection exhaust at the FTE central current sheet. Moreover, pitch angle distributions of suprathermal electrons on either side of the current sheet show different properties, indicating different magnetic connectivities. This FTE‐type structure may thus alternatively be interpreted as two interlaced flux tubes with reconnection at the interface as reported by Kacem et al. (2018) and Øieroset et al. (2019s). The structure may be the result of interaction between two flux tubes, likely produced by multiple VIR at the KH wave trailing edge, and constitutes a new class of phenomenon induced by KH waves.
Statistical Study of Magnetosheath Jet‐Driven Bow Waves
Authors: Liu Terry Z. , Hietala Heli , Angelopoulos Vassilis , Omelchenko Yuri , Vainio Rami , Plaschke Ferdinand 
Published: May 2020

AbstractWhen a magnetosheath jet (localized dynamic pressure enhancements) compresses ambient magnetosheath at a (relative) speed faster than the local magnetosonic speed, a bow wave or shock can form ahead of the jet. Such bow waves or shocks were recently observed to accelerate particles, thus contributing to magnetosheath heating and particle acceleration in the extended environment of Earth's bow shock. To further understand the characteristics of jet‐driven bow waves, we perform a statistical study to examine which solar wind conditions favor their formation and whether it is common for them to accelerate particles. We identified 364 out of 2,859 (~13%) magnetosheath jets to have a bow wave or shock ahead of them with Mach number typically larger than 1.1. We show that large solar wind plasma beta, weak interplanetary magnetic field (IMF) strength, large solar wind Alfvén Mach number, and strong solar wind dynamic pressure present favorable conditions for their formation. We also show that magnetosheath jets with bow waves or shocks are more frequently associated with higher maximum ion and electron energies than those without them, confirming that it is common for these structures to accelerate particles. In particular, magnetosheath jets with bow waves have electron energy flux enhanced on average by a factor of 2 compared to both those without bow waves and the ambient magnetosheath. Our study implies that magnetosheath jets can contribute to shock acceleration of particles especially for high Mach number shocks. Therefore, shock models should be generalized to include magnetosheath jets and concomitant particle acceleration.
Broadband Finite Frequency Ambient Noise Tomography: A Case Study in the Western United States Using USArray Stations
Authors: Zhao Kaifeng , Yang Yingjie , Luo Yinhe 
Published: May 2020

AbstractWe demonstrate the feasibility of finite frequency ambient noise tomography (ANT) in mapping broadband surface wave phase velocities in the western United States using data from the USArray. We obtain cross‐correlation functions (CCFs) of ambient noise data between pairs of stations and then construct a 2‐D phase sensitivity kernel for each CCF between a pair of stations by treating one station as a “virtual” point source and the other as the receiver. Based on a standard, iterative, linearized inversion technique, we develop a finite frequency ANT method and use this method to construct phase velocity maps. These phase velocity maps are very similar to other reported maps generated by established tomography methods based on ray theory at short periods. At intermediate and long periods (>40 s), phase velocity maps based on finite frequency ANT significantly differ from those based on ray theory ANT; however, they are similar with those based on Helmholtz tomography which uses earthquake surface wave data and considers finite frequency effects of surface waves. Our results suggest that finite frequency effects need to be considered in intermediate‐ and long‐period ANT if one intends to resolve upper‐mantle structures with subwavelength scales using ANT.
Modeling Transverse Coastal Bedforms at Anna Maria Island (Florida)
Authors: Blondeaux Paolo , Vittori Giovanna 
Published: May 2020

AbstractSea bedforms with crests perpendicular to the coastline are observed at Anna Maria Island, close to the Passage Key inlet where the local velocity field is mainly driven by tidal currents and episodic longshore currents generated by the passage of cold fronts. An idealized model able to predict the formation and the geometrical characteristics of these bedforms is described. The depth‐averaged oscillating flow generated around the inlet by the tide propagation and by the longshore currents is analyzed by assuming the flow Reynolds number large enough to determine the flow field as the superposition of an irrotational component plus a contribution due to the vorticity shed by the edges of the inlet. Qualitative comparisons of the dynamics of the vortices shed by the inlet edges with laboratory and field visualizations suggest that the approach can provide a reliable evaluation of the depth‐averaged velocity. Then, the geometrical characteristics of the bedforms generated by the interaction of the local flow with the sea bed are determined by means of a linear stability analysis of the flat bed configuration. It is shown that the model fairly predicts the orientation and the wavelength of the observed bedforms. A southward migration of the bedforms is predicted only when the southward episodic currents observed in the area are taken into account.
Prebomb to Postbomb 14C History From the West Side of Palawan Island: Insights Into Oceanographic Changes in the South China Sea
Authors: Wu Yang , Fallon Stewart J. 
Published: May 2020

AbstractCompared to the natural production of 14C, thermonuclear tests have produced a globally abnormal 14C signal. To examine and reconstruct ocean circulation in the South China Sea (SCS), we generated a prebomb to postbomb 14C time series from a Porites lobata coral from the west side of Palawan Island, Philippines. Results show a diluted early bomb 14C intrusion in late 1955. We use this record to extend our understanding of the surface ocean circulation in and around the SCS by tracing 14C labeled water from nuclear test sites. Our postbomb Δ14C peaked at 154‰ in 1975, which lags ~10 years from the atmospheric peak, consistent with other marine records. This coral record also displayed clear seasonal Δ14C cycles indicating different surface waters passed the Palawan Island coral site due to seasonal variations of the East Asian Monsoon.
Quantifying Contributions of Uncertainties in Physical Parameterization Schemes and Model Parameters to Overall Errors in Noah‐MP Dynamic Vegetation Modeling
Authors: Li Jianduo , Chen Fei , Lu Xingjie , Gong Wei , Zhang Guo , Gan Yanjun 
Published: May 2020

AbstractQuantifying contributions of errors in model structure and parameters to biases in a land surface model (LSM) is critical for model improvement. This paper investigated the uncertainties in parameterizations and parameters in the Noah with multiparameterization (Noah‐MP) LSM with dynamic vegetation using eddy flux data. First, we conducted full factorial experiments of eight land subprocesses, followed by sensitivity analysis (SA) to identify the subprocesses for which possible parameterizations made significant difference. Then, based on the full factorial experiments and SA results, we selected the statistically optimal parameterizations combination and the most biased parameterizations combination. Lastly, we calibrated the parameters in two selected parameterizations combinations. The results showed that five subprocesses—surface exchange coefficient, soil moisture β threshold, radiation transfer, runoff and groundwater, and surface resistance to evaporation—had significant influence on the model performances, and the interactions were generally low but contributed up to 80% of the variation in the performance at some sites. In the optimization period, following the criterion by Moriasi et al. (2007, https://doi.org/10.13031/2013.23153), parameter optimization improved the performance of both parameterizations combinations at most sites to be satisfactory, and the superiority between two parameterizations combinations was preserved; in the validation period, adjusting the parameterizations was more robust than parameter optimization in improving LSMs. Finally, we found that uncertainty in soil parameters was much higher than that in vegetation parameters because the optimal soil parameters were significantly different among sites with the same soil types and recommended that spatially calibrating the soil parameters was a major issue for Noah‐MP dynamic vegetation modeling.
Initial Observations by the GOLD Mission
Authors: Eastes R. W. , McClintock W. E. , Burns A. G. , Anderson D. N. , Andersson L. , Aryal S. , Budzien S. A. , Cai X. , Codrescu M. V. , Correira J. T. , Daniell R. E. , Dymond K. F. , England S. L. , Eparvier F. G. , Evans J. S. , Foroosh H. , Gan Q. , Greer K. R. , Karan D. K. , Krywonos A. , Laskar F. I. , Lumpe J. D. , Martinis C. R. , McPhate J. B. , Oberheide J. , Siegmund O. H. , Solomon S. C. , Veibel V. , Woods T. N. 
Published: May 2020

AbstractThe NASA Global‐scale Observations of the Limb and Disk (GOLD) mission has flown an ultraviolet‐imaging spectrograph on SES‐14, a communications satellite in geostationary orbit at 47.5°W longitude. That instrument observes the Earth's far ultraviolet (FUV) airglow at ~134–162 nm using two identical channels. The observations performed include limb scans, stellar occultations, and images of the sunlit and nightside disk from 6:10 to 00:40 universal time each day. Initial analyses reveal interesting and unexpected results as well as the potential for further studies of the Earth's thermosphere‐ionosphere system and its responses to solar‐geomagnetic forcing and atmospheric dynamics. Thermospheric composition ratios for major constituents, O and N2, temperatures near 160 km, and exospheric temperatures are retrieved from the daytime observations. Molecular oxygen (O2) densities are measured using stellar occultations. At night, emission from radiative recombination in the ionosphericFregion is used to quantify ionospheric density variations in the equatorial ionization anomaly (EIA). Regions of depletedFregion electron density are frequently evident, even during the current solar minimum. These depletions are caused by the “plasma fountain effect” and are associated with the instabilities, scintillations, or “spreadF” seen in other types of observations, and GOLD makes unique observations for their study.
Constraining Internal States in Progressive Rock Failure of Carrara Marble by Measuring Residual Strains With Neutron Diffraction
Authors: Voigtländer A. , Leith K. , Walter J. M. , Krautblatter M. 
Published: May 2020

AbstractKnowledge of the internal state of rock is key to anticipate its rheological response and susceptibility to external factors. Time‐dependent failure in rock is controlled by internal state changes, like damage accumulation or strength degradation. But assessing internal states and changes thereof, nondestructively and independent of external forcing is not straightforward. Residual strains, measured with neutron diffraction techniques are used as a proxy for the internal state in material sciences. We investigated its potential for progressive rock failure by measuring residual strain states of an untested and three mechanically and chemomechanically pretested Carrara marble samples. We collected neutron diffraction data for three crystal lattice planes {10̅14}, {0006}, and {11̅20}. Measurements showed an initial overall contractional spatially homogeneous residual unit cell volume strain state of about −400 μstrain, though magnitudes were strongly partitioned among measured crystal lattice planes. However, they are equal within the spatial orientations of the intact sample. For the pretested samples, the induction and relaxation of strains varied spatially with the pretesting stress field and environmental conditions. The vertical extent of superposition of the initial residual strain state was greatest in wet samples, the magnitude of induced extensional strain highest in the dry sample. This indicates chemomechanically enhanced subcritical crack growth with concomitant residual strain relaxation as well as the mitigation of extensional strain built up by the presence of water during pretesting. Our experiments show that residual strain has a significant potential to provide insights into past and actual internal states to anticipate progressive rock failure.