bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic behavior of coalbed methane flow along the annulus of single-phase production
Authors: Liu Xinfu , Liu Chunhua , Liu Guoqiang 
Published: October 2019

Abstract
Dynamic behavior of coalbed methane (CBM) flow will provide the theoretical basis to optimize production performance for a given well. A mathematical model is developed to simulate flowing pressures and pressure drops of CBM column from well head to bottom hole. The measured parameters and independent variables of flow rates, flowing pressures and temperatures are involved in CBM producing process along the annulus. The developed relationships are validated against full-scale measured data in single-phase CBM wellbores. The proposed methodology can analyze the dynamic behavior in CBM reservoir and process of CBM flow with an overall accuracy of 2%. The calculating process of flowing pressures involves friction factor with variable Reynolds number and CBM temperature and compressibility factor with gravitational gradients. The results showed that the effect of flowing pressure on CBM column was more obvious than that on CBM and water column accompanied by an increase of dynamic water level. The ratios of flowing pressure on increment of CBM column to the whole column increased with the declined flow rates of water column. Bottom-hole pressure declined with the decreased flowing pressure of CBM column along the annulus. It will lead to the results of the increased pressure drop of CBM column and CBM flow rate in single-phase CBM wellbores.
Longitudinal study of self‐reported hearing loss and subjective cognitive function decline in women
Authors: Curhan Sharon G. , Willett Walter C. , Grodstein Francine , Curhan Gary C. 
Published: October 2019

AbstractIntroductionWe investigated the relation between self‐reported hearing loss and risk of subjective cognitive function (SCF) decline among women.MethodsWe conducted a longitudinal study of 20,193 women in the Nurses’ Health Study aged ≥66 years who reported their hearing status and had no subjective cognitive concerns in 2012. SCF scores were assessed by a 7‐item questionnaire in 2012 and 2014. SCF decline was defined as a new report of at least one cognitive concern during follow‐up.ResultsSelf‐reported hearing loss was associated with higher risk of SCF decline. Compared with women with no hearing loss, the multivariable‐adjusted odds ratios (95% confidence interval) for incident SCF score ≥1 were 1.35 (1.25, 1.47), 1.39 (1.24, 1.56), and 1.40 (1.21, 1.75) among women with mild, moderate, and severe hearing loss, respectively. Recent progression of hearing loss was associated with even higher risk.DiscussionSelf‐reported hearing loss was associated with higher risk of incident subjective cognitive function decline in women.
Epidemiological Characteristics and Risk Factors of Posttraumatic Stress Disorder in Chinese Children After Exposure to an Injury
Authors: Yu Huiting , Nie Chan , Zhou Yanna , Wang Xue , Wang Haiyan , Shi Xiuquan 
Published: October 2019

ABSTRACTObjective:The aim of this study is to describe the risk factors of injured children’s posttraumatic stress disorder (PTSD) in China and provide the scientific data for PTSD prevention and control in children.Methods:Electronic databases, including Medline, Science Direct, Google Scholar, and CNKI (China National Knowledge Infrastructure), were searched for articles published on or before October 30, 2018, searching for the words, “PTSD,” “child”/“children,” “injury”/“injuries,” and “China”/“Chinese.” Forty-seven articles met the inclusion criteria and were meta-analyzed using random-effect models.Results:The total sample size in our meta-analysis was 65 298, and there were 13 402 children diagnosed with PTSD. The prevalence of PTSD after suffering from injury was 20.52% (95% CI = 17%–23%). PTSD occurrence was higher in girls than boys (24.61% vs 19.36%, P < 0.001). The PTSD rate for students was 51.82%, 37.12%, and 14.02% in senior, junior high school children, and primary school student, respectively. PTSD prevalence was 58.93% in rural children and higher than the urban children (57.36%). The prevalence of PTSD in ethnic minority children was significantly higher than that of Han Chinese children (35.38% vs 13.50%).Conclusion:PTSD in injured children is significantly higher in girls, senior high school children, in rural areas, and in ethnic minority children. PTSD prevention and control should be focused on these 4 subgroups.
The Asymmetry of population ethics: experimental social choice and dual-process moral reasoning
Authors: Spears Dean 
Published: October 2019

AbstractPopulation ethics is widely considered to be exceptionally important and exceptionally difficult. One key source of difficulty is the conflict between certain moral intuitions and analytical results identifying requirements for rational (in the sense of complete and transitive) social choice over possible populations. One prominent such intuition is the Asymmetry, which jointly proposes that the fact that a possible child’s quality of life would be bad is a normative reason not to create the child, but the fact that a child’s quality of life would be good is not a reason to create the child. This paper reports a set of questionnaire experiments about the Asymmetry in the spirit of economists’ empirical social choice. Few survey respondents show support for the Asymmetry; instead respondents report that expectations of a good quality of life are relevant. Each experiment shows evidence (among at least some participants) of dual-process moral reasoning, in which cognitive reflection is statistically associated with reporting expected good quality of life to be normatively relevant. The paper discusses possible implications of these results for the economics of population-sensitive social welfare and for the conflict between moral mathematics and population intuition.
Mapping Stress and Structure From Subducting Slab to Magmatic Rift: Crustal Seismic Anisotropy of the North Island, New Zealand
Authors: Illsley‐Kemp Finnigan , Savage Martha K. , Wilson Colin J. N. , Bannister Stephen 
Published: October 2019

AbstractWe use crustal seismic anisotropy measurements in the North Island, New Zealand, to examine structures and stress within the Taupō Volcanic Zone, the Taranaki Volcanic Lineament, the subducting Hikurangi slab, and the Hikurangi forearc. Results in the Taranaki region are consistent with NW‐SE oriented extension yet suggest that the Taranaki volcanic lineament may be controlled by a deep‐rooted, inherited crustal structure. In the central Taupō Volcanic Zone anisotropy fast orientations are predominantly controlled by continental rifting. However at Taupō and Okataina volcanoes, fast orientations are highly variable and radial to the calderas suggesting the influence of magma reservoirs in the seismogenic crust (≤15 km depth). The subducting Hikurangi slab has a predominant trench‐parallel fast orientation, reflecting the pervasive presence of plate‐bending faults, yet changing orientations at depths ≥120 km beneath the central North Island may be relics from previous subduction configurations. Finally, results from the southern Hikurangi forearc show that the orientation of stresses there is consistent with those in the underlying subducting slab. In contrast, the northern Hikurangi forearc is pervasively fractured and is undergoing E‐W compression, oblique to the stress field in the subducting slab. The north‐south variation in fore‐arc stress is likely related to differing subduction‐interface coupling. Across the varying tectonic regimes of the North Island our study highlights that large‐scale tectonic forces tend to dictate the orientation of stress and structures within the crust, although more localized features (plate coupling, magma reservoirs, and inherited crustal structures) can strongly influence surface magmatism and the crustal stress field.
On the Relation Between Jovian Aurorae and the Loading/Unloading of the Magnetic Flux: Simultaneous Measurements From Juno, Hubble Space Telescope, and Hisaki
Authors: Yao Z. H. , Grodent D. , Kurth W. S. , Clark G. , Mauk B. H. , Kimura T. , Bonfond B. , Ye S.‐Y. , Lui A. T. , Radioti A. , Palmaerts B. , Dunn W. R. , Ray L. C. , Bagenal F. , Badman S. V. , Rae I. J. , Guo R. L. , Pu Z. Y. , Gérard J.‐C. , Yoshioka K. , Nichols J. D. , Bolton S. J. , Levin S. M. 
Published: October 2019

AbstractWe present simultaneous observations of aurorae at Jupiter from the Hubble Space Telescope and Hisaki, in combination with the in situ measurements of magnetic field, particles, and radio waves from the Juno Spacecraft in the outer magnetosphere, from ~ 80RJ to 60RJ during 17 to 22 March 2017. Two cycles of accumulation and release of magnetic flux, named magnetic loading/unloading, were identified during this period, which correlate well with electron energization and auroral intensifications. Magnetic reconnection events are identified during both the loading and unloading periods, indicating that reconnection and unloading are independent processes. These results show that the dynamics in the middle magnetosphere are coupled with auroral variability.
Rapid CO2 Release From Eroding Permafrost in Seawater
Authors: Tanski G. , Wagner D. , Knoblauch C. , Fritz M. , Sachs T. , Lantuit H. 
Published: October 2019

AbstractPermafrost is thawing extensively due to climate warming. When permafrost thaws, previously frozen organic carbon (OC) is converted into carbon dioxide (CO2) or methane, leading to further warming. This process is included in models as gradual deepening of the seasonal non‐frozen layer. Yet, models neglect abrupt OC mobilization along rapidly eroding Arctic coastlines. We mimicked erosion in an experiment by incubating permafrost with seawater for an average Arctic open‐water season. We found that CO2 production from permafrost OC is as efficient in seawater as without. For each gram (dry weight) of eroding permafrost, up to 4.3 ± 1.0 mg CO2 will be released and 6.2 ± 1.2% of initial OC mineralized at 4 °C. Our results indicate that potentially large amounts of CO2 are produced along eroding permafrost coastlines, onshore and within nearshore waters. We conclude that coastal erosion could play an important role in carbon cycling and the climate system.
Remarkable Capacity for Anaerobic Oxidation of Methane at High Methane Concentration
Authors: Bowles M.W. , Samarkin V.A. , Hunter K.S. , Finke N. , Teske A.P. , Girguis P.R. , Joye S.B. 
Published: October 2019

AbstractAnaerobic oxidation of methane (AOM), a central process in the carbon cycle of anoxic environments, moderates the release of methane from soils and sediments to water bodies and, ultimately, the atmosphere. The regulation of AOM in the environment remains poorly constrained. Here we quantified AOM and sulfate reduction (SR) rates in diverse deep seafloor samples at in situ pressure and methane concentration and discovered that, in some cases, AOM exceeded SR rates by more than four times when methane concentrations were above 5 mM. Methane concentration also affected other carbon‐cycling processes (e.g., carbon assimilation) in addition to SR. These results illustrate that substantial amounts of methane may be oxidized independent of SR under in situ conditions, reshaping our view of the capacity and mechanism of AOM in methane‐rich environments, including the deep biosphere, where sulfate availability is considered to limit AOM.
Spatial and Temporal Quantification of Spontaneous Imbibition
Authors: Zahasky Christopher , Benson Sally M. 
Published: October 2019

AbstractSpontaneous imbibition—the process of a wetting fluid displacing a nonwetting fluid purely by capillary forces—is a ubiquitous phenomenon in porous and fibrous materials. Here we present a new experimental method for quantification of spontaneous imbibition in geologic materials. This method makes it possible to perform spontaneous imbibition under elevated pressure conditions relevant to environmental and energy resource applications. Computed tomography imaging reveals a new time‐independent scaling relationship that describes local imbibition rates as a function of water saturation. Imbibition capillary pressure curves are calculated with this wetting‐phase pressure and flow rate characterization, with no assumptions about the functional form, end point behavior, or scaling factors. Calculated end point capillary pressure is nonzero, in agreement with recent pore‐scale measurements of capillary pressure of trapped nonwetting phase. This work provides a new approach and insights into trapping and remobilization of nonwetting fluids in CO2 storage reservoirs and contaminated groundwater aquifers.
A Fermi Gamma‐Ray Burst Monitor Event Observed as a Terrestrial Gamma‐Ray Flash and Terrestrial Electron Beam
Authors: Stanbro M. , Briggs M. S. , Roberts O. J. , Cramer E. , Dwyer J. R. , Holzworth R.H. , Mailyan B. G. , Xiong S. L. 
Published: October 2019

AbstractWe present an event that was detected by Fermi Gamma‐ray Burst Monitor on 4 February 2014 as the spacecraft was flying over Madagascar. We interpret the three pulses during this event (herein known as 140204581) as the following: the first pulse as a terrestrial gamma‐ray flash, the second as a 2 ms long terrestrial electron beam (TEB) 0.5 ms after the terrestrial gamma‐ray flash, and the last pulse as the TEB mirror pulse 90 ms after the TEB. The nature of these events were confirmed using both the World Wide Lightning Location Network and the Earth Networks Total Lightning Network, which detected the same simultaneous sferic underneath the spacecraft and in the magnetic footprint. Several models were fit to the data, and results show that the vertical narrow beam model was found to be inconsistent with the data.
Magnetosphere‐Ionosphere‐Thermosphere Coupling at Jupiter Using a Three‐Dimensional Atmospheric General Circulation Model
Authors: Yates J. N. , Ray L. C. , Achilleos N. , Witasse O. , Altobelli N. 
Published: October 2019

AbstractJupiter's upper atmosphere is ∼700 K hotter than predicted based on solar extreme ultraviolet heating alone. The reason for this still remains a mystery and is known as the “energy crisis.” It is thought that the interaction between Jupiter and its dynamic magnetosphere plays a vital role in heating its atmosphere to the observed temperatures. Here, we present a new model of Jupiter's magnetosphere‐ionosphere‐thermosphere‐coupled system where we couple a three‐dimensional atmospheric general circulation model to an axisymmetric magnetosphere model. We find that the model temperatures are on average ∼60 K, with a maximum of ∼200 K, hotter than the model's two‐dimensional predecessor making our high‐latitude temperatures comparable to the lower limit of observations. Stronger meridional winds now transport more heat from the auroral region to the equator increasing the equatorial temperatures. However, despite this increase, the modeled equatorial temperatures are still hundreds of kelvins colder than observed. We use this model as an intermediate step toward a three‐dimensional atmospheric model coupled to a realistic magnetosphere model with zonal and radial variation.
Tropical Lows in Southern Africa: Tracks, Rainfall Contributions, and the Role of ENSO
Authors: Howard Emma , Washington Richard , Hodges Kevin I. 
Published: October 2019

AbstractSouthern African tropical lows are synoptic‐scale cyclonic vortices that propagate westward across southern Africa in the Austral summer. They strongly influence local rainfall and aggregate in the climatological December, January, and February mean to form the Angola Low. In this study, tropical lows are identified and tracked using an objective feature tracking method. The statistics of tropical low tracks over southern Africa are presented and compared across three reanalysis products. Findings are compared to the literature of tropical low‐pressure areas elsewhere in the world, where it is found that most tracking statistics compare well but that the tendency of tropical lows to become semistationary over Angola is unique to southern Africa. The hypothesis that tropical lows in Angola have a causal relationship with Tropical Temperate Troughs is tested, and a correlation between occurrence frequencies is found at interannual but not daily time scales. Precipitation is attributed to the tropical lows, and it is found that tropical lows are associated with 31% of rainfall across tropical southern Africa, based on gridded precipitation products. The interannual variability of the number of tropical lows that form per year (σ=6 events/year) is linked to El Niño–Southern Oscillation (ENSO) and the tropical easterly jet. The mean latitude of tropical lows is shifted northward during El Niño and southward during La Niña. Much of the interannual precipitation variability maximum in Angola is attributed to rainfall associated with tropical lows. These results provide insights into the southern African response to ENSO and into the mechanisms of rainfall in the southern African tropical edge.
The Seismic Signatures of Recently Formed Impact Craters on Mars
Authors: Schmerr N. C. , Banks M. E. , Daubar I. J. 
Published: October 2019

AbstractWe investigated the seismic signatures of recent impact crater clusters on Mars that would be recorded by the Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) seismometers. We used a database of 77 measured and dated impact sites, with craters with diameters between 2.1 and 33.8 m, along with inferred impact angle, bolide trajectory, and varying target material properties to empirically scale for the momentum, expected seismic source function, and radiation pattern of impacts. The impact source is simulated in a local 3‐D finite difference wave propagation code and coupled to teleseismic distances by scaling the spectra of 1‐D global synthetic seismograms. We use the InSight seismometer noise floors to estimate detectability of impact(s) across azimuth and distance. Our experiments reveal that impact clusters have a higher peak corner frequency resulting from energy contributed by smaller craters to the power spectrum. We also find that the time separation between individual impacts in a cluster is small (<10–15 ms) and requires a seismometer closely situated to the source (<10 km) and a high sampling rate (>100 Hz) to resolve individual impacts within the cluster. Two of the clusters in our database (>20‐m effective diameter) would have been detectable by InSight, with the assumptions that the Martian background noise and seismic attenuation are both low. Joint detection of surface changes from newly formed crater(s) in images and by InSight will provide precise source locations that are crucial for constraining the internal structure of Mars.
Impact History and Regolith Evolution on the Moon: Geochemistry and Ages of Glasses from the Apollo 16 Site
Authors: Norman Marc D. , Jourdan Fred , Hui Simeon S. M. 
Published: October 2019

AbstractLunar impact glasses are quenched droplets of melt that carry geochemical records of their target compositions, formation ages, and time‐integrated exposure in the upper layers of the lunar regolith. Here we present the first study to obtain major element, trace element, and Ar isotopic data for impact glasses from the Apollo 16 regolith sample 66031. Thirty particles were analysed with 27 of them yielding useable age information. The glasses have a wide range of major and trace element compositions, similar to that observed in lunar meteorites. Half of these glasses have compositions similar to Apollo 16 soils and are considered to be “locally derived”, whereas the others represent diverse source regions and are considered to be “exotic” particles that were delivered from a considerable distance to the landing site.Almost 40% of the samples analysed for this study have formation ages younger than 500 Ma. Duplicate particles produced in single impact events contribute minimally to the age distribution, and diurnal or transient heating of the regolith does not appear to have had a significant effect on the 40Ar/39Ar ages. Rather, the ages reflect primarily the formation of these glasses by impact melting, with the distribution modified to some degree by preservation bias. As most of these glasses are likely formed by relatively small impactors, their age distribution cannot be compared directly with the crystalline lunar melt rocks to constrain the impact mass flux through time.
Icelandic Pit Chains as Planetary Analogs: Using Morphologic Measurements of Pit Chains to Determine Regolith Thickness
Authors: Whitten Jennifer L. , Martin Emily S. 
Published: October 2019

AbstractPit chains are distinctive geologic landforms present on planetary bodies across the solar system, which can be used to understand regolith properties and formation. If there is a direct relationship between pit diameter and the regolith depth, pit chains can be used to map regolith thickness across a planetary surface. Here, the morphology of individual pits within pit chains in northern Iceland was measured as a planetary analog to determine whether there is a direct relationship between individual pit diameters and pit depth, which is assumed to be a proxy for regolith depth. The morphology of pit chains and regolith thickness was measured in three different locations in northern Iceland, within two different substrates: unconsolidated floodplain sediments and more consolidated soils overlaying basaltic lava flows. There is a significant linear relationship between pit diameter and depth for pit chains located in the floodplain sediment, but not for pits located in basaltic materials. However, this depth‐diameter relationship does not correlate with regolith thickness. The depth of the pits in basaltic materials is more representative of the regolith depth than the pits in the floodplain sediments. If high‐resolution topography data are available, then the depth of pits in more consolidated materials can be used as a reliable estimate of regolith thickness. In more unconsolidated materials, the pit depth represents a minimum regolith depth. This ability to resolve regolith thicknesses may help resolve the processes by which regolith is emplaced and has implications for the thermal evolution of planetary bodies.