bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transient brightening of Jupiter's aurora observed by the Hisaki satellite and Hubble Space Telescope during approach phase of the Juno spacecraft
Authors: Kimura T. , Nichols J. D. , Gray R. L. , Tao C. , Murakami G. , Yamazaki A. , Badman S. V. , Tsuchiya F. , Yoshioka K. , Kita H. , Grodent D. , Clark G. , Yoshikawa I. , Fujimoto M. 
Published: May 2017

AbstractIn early 2014, continuous monitoring with the Hisaki satellite discovered transient auroral emission at Jupiter during a period when the solar wind was relatively quiet for a few days. Simultaneous imaging made by the Hubble Space Telescope (HST) suggested that the transient aurora is associated with a global magnetospheric disturbance that spans from the inner to outer magnetosphere. However, the temporal and spatial evolutions of the magnetospheric disturbance were not resolved because of the lack of continuous monitoring of the transient aurora simultaneously with the imaging. Here we report the coordinated observation of the aurora and plasma torus made by Hisaki and HST during the approach phase of the Juno spacecraft in mid‐2016. On day 142, Hisaki detected a transient aurora with a maximum total H2 emission power of ~8.5 TW. The simultaneous HST imaging was indicative of a large “dawn storm,” which is associated with tail reconnection, at the onset of the transient aurora. The outer emission, which is associated with hot plasma injection in the inner magnetosphere, followed the dawn storm within less than two Jupiter rotations. The monitoring of the torus with Hisaki indicated that the hot plasma population increased in the torus during the transient aurora. These results imply that the magnetospheric disturbance is initiated via the tail reconnection and rapidly expands toward the inner magnetosphere, followed by the hot plasma injection reaching the plasma torus. This corresponds to the radially inward transport of the plasma and/or energy from the outer to the inner magnetosphere.
The analysis of initial Juno magnetometer data using a sparse magnetic field representation
Authors: Moore Kimberly M. , Bloxham Jeremy , Connerney John E. P. , Jørgensen John L. , Merayo José M. G. 
Published: May 2017

AbstractThe Juno spacecraft, now in polar orbit about Jupiter, passes much closer to Jupiter's surface than any previous spacecraft, presenting a unique opportunity to study the largest and most accessible planetary dynamo in the solar system. Here we present an analysis of magnetometer observations from Juno's first perijove pass (PJ1; to within 1.06 RJ of Jupiter's center). We calculate the residuals between the vector magnetic field observations and that calculated using the VIP4 spherical harmonic model and fit these residuals using an elastic net regression. The resulting model demonstrates how effective Juno's near‐surface observations are in improving the spatial resolution of the magnetic field within the immediate vicinity of the orbit track. We identify two features resulting from our analyses: the presence of strong, oppositely signed pairs of flux patches near the equator and weak, possibly reversed‐polarity patches of magnetic field over the polar regions. Additional orbits will be required to assess how robust these intriguing features are.
A planetary‐scale disturbance in the most intense Jovian atmospheric jet from JunoCam and ground‐based observations
Authors: Sánchez‐Lavega A. , Rogers J. H. , Orton G. S. , García‐Melendo E. , Legarreta J. , Colas F. , Dauvergne J. L. , Hueso R. , Rojas J. F. , Pérez‐Hoyos S. , Mendikoa I. , Iñurrigarro P. , Gomez‐Forrellad J. M. , Momary T. , Hansen C. J. , Eichstaedt G. , Miles P. , Wesley A. 
Published: May 2017

AbstractWe describe a huge planetary‐scale disturbance in the highest‐speed Jovian jet at latitude 23.5°N that was first observed in October 2016 during the Juno perijove‐2 approach. An extraordinary outburst of four plumes was involved in the disturbance development. They were located in the range of planetographic latitudes from 22.2° to 23.0°N and moved faster than the jet peak with eastward velocities in the range 155 to 175 m s−1. In the wake of the plumes, a turbulent pattern of bright and dark spots (wave number 20–25) formed and progressed during October and November on both sides of the jet, moving with speeds in the range 100–125 m s−1 and leading to a new reddish and homogeneous belt when activity ceased in late November. Nonlinear numerical models reproduce the disturbance cloud patterns as a result of the interaction between local sources (the plumes) and the zonal eastward jet.
Preliminary JIRAM results from Juno polar observations: 3. Evidence of diffuse methane presence in the Jupiter auroral regions
Authors: Moriconi M. L. , Adriani A. , Dinelli B. M. , Fabiano F. , Altieri F. , Tosi F. , Filacchione G. , Migliorini A. , Gérard J. C. , Mura A. , Grassi D. , Sindoni G. , Piccioni G. , Noschese R. , Cicchetti A. , Bolton S. J. , Connerney J. E. P. , Atreya S. K. , Bagenal F. , Gladstone G. R. , Hansen C. , Kurth W. S. , Levin S. M. , Mauk B. H. , McComas D. J. , Turrini D. , Stefani S. , Olivieri A. , Amoroso M. 
Published: May 2017

AbstractThroughout the first orbit of the NASA Juno mission around Jupiter, the Jupiter InfraRed Auroral Mapper (JIRAM) targeted the northern and southern polar regions several times. The analyses of the acquired images and spectra confirmed a significant presence of methane (CH4) near both poles through its 3.3 μm emission overlapping the H3+ auroral feature at 3.31 μm. Neither acetylene (C2H2) nor ethane (C2H6) have been observed so far. The analysis method, developed for the retrieval of H3+ temperature and abundances and applied to the JIRAM‐measured spectra, has enabled an estimate of the effective temperature for methane peak emission and the distribution of its spectral contribution in the polar regions. The enhanced methane inside the auroral oval regions in the two hemispheres at different longitude suggests an excitation mechanism driven by energized particle precipitation from the magnetosphere.
Juno's first glimpse of Jupiter's complexity
Authors: Bolton Scott , Levin Steven , Bagenal Fran 
Published: May 2017

AbstractPreliminary results from NASA's Juno mission are presented in this special issue of Geophysical Research Letters. The data were gathered by nine scientific instruments as the Juno spacecraft approached Jupiter on the dawn flank, was inserted into Jupiter orbit on 4 July 2016, and made the first polar passes close to the planet. The first results hint that Jupiter may not have a distinct core, indicate puzzling deep atmospheric convection, and reveal complex small‐scale structure in the magnetic field and auroral processes that are distinctly different from those at Earth.
Electron density variability of nighttime D region ionosphere in Vietnamese and Japanese sectors
Authors: Tan Le Minh , Shiokawa Kazuo , Thu Nguyen Ngoc , Ha Tran Quoc 
Published: May 2017

AbstractRecording tweek atmospherics on geomagnetically quiet days in 2014 at Tay Nguyen University (TNU) (12.65°N, 108.02°E), Vietnam, and at Kagoshima (KAG) (31.48°N, 130.72°E), Japan, we investigated the nighttime electron density variability of the D region ionosphere between the equatorial‐low‐latitude Vietnamese and the low‐ to middle‐latitude Japanese sectors. We estimated the reflection height and electron density of the D region ionosphere using the first‐order mode cutoff frequency of tweek atmospherics. The results observed at both stations show that the mean electron density at the reflection height during winter season was higher than that during summer and equinox seasons. The electron density observed at TNU gradually decreased from 20:15 to 4:15 LT from winter to equinox and to summer. The electron density observed at KAG increased from 20:20 to 4:20 LT during summer and winter seasons. The mean electron density during 2014 observed at TNU (25.0 cm−3) was higher by 2.1 cm−3 than that observed at KAG (22.9 cm−3). During 2014, the nighttime electron density variations show a moderate positive correlation with the sunspot number but show weak to no correlation with the galactic cosmic rays. We suggest that the seasonal variations in the nighttime electron density could be significantly caused by the enhancement of geocoronal hydrogen Lyman α intensity and seasonal variation of nitric oxide density in the lower ionosphere.
Warm layer and cool skin corrections for bulk water temperature measurements for air‐sea interaction studies
Authors: Alappattu Denny P. , Wang Qing , Yamaguchi Ryan , Lind Richard J. , Reynolds Mike , Christman Adam J. 
Published: May 2017

AbstractThe sea surface temperature (SST) relevant to air‐sea interaction studies is the temperature immediately adjacent to the air, referred to as skin SST. Generally, SST measurements from ships and buoys are taken at depths varies from several centimeters to 5 m below the surface. These measurements, known as bulk SST, can differ from skin SST up to O(1°C). Shipboard bulk and skin SST measurements were made during the Coupled Air‐Sea Processes and Electromagnetic ducting Research east coast field campaign (CASPER‐East). An Infrared SST Autonomous Radiometer (ISAR) recorded skin SST, while R/V Sharp's Surface Mapping System (SMS) provided bulk SST from 1 m water depth. Since the ISAR is sensitive to sea spray and rain, missing skin SST data occurred in these conditions. However, SMS measurement is less affected by adverse weather and provided continuous bulk SST measurements. It is desirable to correct the bulk SST to obtain a good representation of the skin SST, which is the objective of this research. Bulk‐skin SST difference has been examined with respect to meteorological factors associated with cool skin and diurnal warm layers. Strong influences of wind speed, diurnal effects, and net longwave radiation flux on temperature difference are noticed. A three‐step scheme is established to correct for wind effect, diurnal variability, and then for dependency on net longwave radiation flux. Scheme is tested and compared to existing correction schemes. This method is able to effectively compensate for multiple factors acting to modify bulk SST measurements over the range of conditions experienced during CASPER‐East.
Icing detection and identification for unmanned aerial vehicles using adaptive nested multiple models
Authors: Cristofaro Andrea , Johansen Tor Arne , Aguiar A. Pedro 
Published: May 2017

SummaryA multiple‐model approach for icing diagnosis and identification in small unmanned aerial vehicles is proposed. The accretion of ice layers on wings and control surfaces modifies the shape of the aircraft and, consequently, alters the performance and controllability of the vehicle. Pitot tubes might be blocked due to icing, providing errors in the airspeed measurements. In this paper, we propose a nested multiple‐model adaptive estimation framework to detect and estimate icing using standard sensors only, ie, a pitot tube and an inertial measurement unit. The architecture of the estimation scheme is based on 2 different time scales, ie, one for the accretion of ice on aircraft surfaces and one for the accretion of ice on sensors, and consists of 2 nested adaptive observers, namely, outer and inner loops, respectively. The case study of a typical small unmanned aerial vehicle supports and validates the proposed theoretical results.
Double closed‐loop control with adaptive strategy for automotive engine speed tracking system
Authors: Feng Meiyu , Jiao Xiaohong 
Published: May 2017

SummaryIn order to improve the transient and static performances of an engine speed control system in a wide speed range, this paper presents an adaptive double closed‐loop control strategy. The control scheme possesses intake manifold pressure inner closed‐loop adaptive proportional‐integral control and engine speed outer closed‐loop adaptive proportional‐integral control for achieving the tracking precision in a wide range of speed, as well as adaptive nonlinearity and feedforward compensators for overcoming parameter uncertainty and nonlinearity. The whole closed‐loop system's stability and the speed tracking convergence are ensured theoretically by the Lyapunov stability theory and the LaSalle invariant principle. The effectiveness of the proposed control strategy is validated through the operation results on the simulator of a V6 engine exploited by the Research Committee of the Society of Instrument and Control Engineers of Japan.
Doping‐Free Asymmetrical Silicon Heterocontact Achieved by Integrating Conjugated Molecules for High Efficient Solar Cell
Authors: Liu Jiawei , Ji Yujin , Liu Yuqiang , Xia Zhouhui , Han Yujie , Li Youyong , Sun Baoquan 
Published: May 2017

AbstractOrganic conjugated molecule/silicon (Si) heterojunction has been widely investigated to build up an asymmetrical heterocontact for efficient photovoltaics. However, it is still unclear how the organic molecular structures can affect their electronic coupling interaction with Si. Here, two widely explored electron acceptors of poly{[N,N′‐bis(2‐octyldodecyl)‐naphthalene‐1,4,5,8‐bis(dicarboximide)‐2,6‐diyl]‐alt‐5,5′‐(2,2′‐bithiophene)} (N2200) and [6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM) are used to build up asymmetrical Si heterocontact to investigate their electronic coupling interaction. It is found that PCBM displays different electronic coupling with Si from N2200, which is ascribed to their various physical distance with Si based on a systematic and detailed density functional theory calculation. Organic layer incorporation not only suppresses the surface charge recombination velocity but also leads to an Ohmic contact between Si and Al. Therefore, a doping‐free organic/Si heterojunction photovoltaic with a power conversion efficiency of 14.9% is achieved with PCBM layer. This work discloses a key factor affecting organic/Si electronic coupling interaction, which helps build up high quality Si heterocontact for solar cells and other optoelectronic devices. Furthermore, the simplified heterocontact achieved by a low temperature, solution processed, and lithography‐free steps has a dramatic improvement on conventional diffusion doped‐silicon one at high temperature.
Cs‐Symmetric Donor–Acceptor Bis(thiazole)s: Synthesis and Photophysical, Electrochemical, and Computational Studies
Authors: Maragani Ramesh , Bijesh S. , Sharma Rekha , Misra Rajneesh 
Published: May 2017

AbstractWe herein report the design and synthesis of Cs‐symmetric donor–acceptor (D–A) molecular systems that have electron‐donating and electron‐withdrawing groups of the type D‐π‐A‐π‐D and D‐A1‐A‐A1‐D by using a Pd‐catalyzed Sonogshira cross‐coupling and [2+2] cycloaddition–retroelectrocyclization reactions. The photophysical and electrochemical properties as well as computational studies of these systems were explored, and strong donor–acceptor interactions were found. The [2+2] cycloaddition–retroelectrocyclization reaction pathway was studied by computational calculations, which revealed that bis(thiazole)s that contain donor groups at the terminal positions were favored in the reaction with tetracyanoethene (TCNE), whereas bis(thiazole)s that contain electron‐withdrawing groups were disfavored.
Behavioral inferences from the high levels of dental chipping in Homo naledi
Authors: Towle Ian , Irish Joel D. , De Groote Isabelle 
Published: May 2017

AbstractObjectivesA variety of mechanical processes can result in antemortem dental chipping. In this study, chipping data in the teeth of Homo naledi are compared with those of other pertinent dental samples to give insight into their etiology.Materials and methodsPermanent teeth with complete crowns evidencing occlusal wear were examined macroscopically. The location, number, and severity of fractures were recorded and compared to those found in samples of two other South African fossil hominin species and in samples of nonhuman primates (n = 3) and recent humans (n = 7).ResultsWith 44% of teeth affected, H. naledi exhibits far higher rates of chipping than the other fossil hominin samples. Specifically, 50% of posterior teeth and 31% of anterior teeth display at least one chip. The maxillary teeth are more affected than the mandibular teeth (45% vs 43%, respectively), 73% of molar chipping occurs on interproximal surfaces, and right teeth are more often affected than left teeth (50% vs 38%).DiscussionResults indicate that the teeth of H. naledi were exposed to acute trauma on a regular basis. Because interproximal areas are more affected than buccal and posterior teeth more than anterior, it is unlikely that nonmasticatory cultural behavior was the cause. A diet containing hard and resistant food, or contaminants such as grit, is more likely. The small chip size, and steep occlusal wear and cupped dentine on some molars are supportive of the latter possibility. This pattern of chipping suggests that H. naledi differed considerably—in terms of diet, environment, and/or specialized masticatory processing—relative to other African fossil hominins.
Household pet exposure, allergic sensitization, and rhinitis in the U.S. population
Authors: Shargorodsky Josef , Garcia‐Esquinas Esther , Umanskiy Rachel , Navas‐Acien Ana , Lin Sandra Y. 
Published: May 2017

BackgroundThe effect of animal dander exposure on allergic sensitization may be age‐dependent. A comparison between the association of the levels of exposure to pet allergen with rhinitis symptoms and allergic sensitization in children and adults is yet to be performed in the U.S. population.MethodsCross‐sectional study of 3034 adults (age, 20 to 85 years) and 2104 children (age, 6 to 19 years) in the National Health and Nutrition Examination Survey, 2005–2006. Samples of household dust were collected to measure the amounts of indoor allergens in the participants’ homes. Self‐reported rhinitis was based on symptoms during the past 12 months, and allergen sensitization was defined as a positive response to any of the 19 specific immunoglobulin E (IgE) antigens tested.ResultsHigher levels of exposure to dog dander were associated with a higher prevalence of any allergic sensitization in adults (prevalence ratio [PR] 1.19; 95% confidence interval [CI], 1.01 to 1.39), but a lower prevalence in children (PR 0.84; 95% CI, 0.73 to 0.096), p‐interaction by age group 0.02. Cat exposure was associated with an increased prevalence of rhinitis symptoms in adults (PR for the 3rd vs lowest tertile of cat dander concentrations: 1.14; 95% CI, 1.05 to 1.23) but not in children (PR for the 3rd vs lowest tertile of cat dander IgE concentrations: 0.86; 95% CI, 0.70 to 1.07), p‐interaction 0.01.ConclusionAllergic sensitization and symptomatic response to pet dander exposure may vary based on age. Further studies are necessary to assess the mechanisms for these apparent differences.
Relative susceptibility of airway organisms to antimicrobial effects of nitric oxide
Authors: Workman Alan D. , Carey Ryan M. , Kohanski Michael A. , Kennedy David W. , Palmer James N. , Adappa Nithin D. , Cohen Noam A. 
Published: May 2017

BackgroundNitric oxide (NO) is released in the airway as a critical component of innate immune defense against invading pathogenic organisms. It is well documented that bacteriostatic and bactericidal effects of NO are concentration‐dependent. However, few data exist comparing relative susceptibility of common pathogens to NO at physiologic concentrations. In this study we evaluated the effects of NO on 4 common airway bacteria and 1 fungus, and examined the potential implications of discrepancies in sensitivity.MethodsStaphylococcus epidermis, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Candida albicans cultures were adjusted to a uniform optical density (OD) and grown in log phase at 37°C with varying concentrations of NO formed by DETA NONOate. Both OD readings and colony forming units (CFUs) were measured at varying time‐points to evaluate for inhibitory effects of NO.ResultsP aeruginosa and C albicans were significantly more sensitive to NO at physiologic concentrations typical of the human airway. S aureus was attenuated by NO to a lesser degree, and K pneumoniae and S epidermis were more resistant to NO at all concentrations tested. Air surface liquid from cultured human sinonasal epithelial cells had an additive effect in bacterial killing of P aeruginosa, but not in S aureus.ConclusionCommon airway pathogens have varying levels of susceptibility to NO at physiologic concentrations of innate immune defense. Relative sensitivity of P aeruginosa and relative resistance of S epidermis may help explain the composition of the healthy microbiome, as well as opportunistic infection in the absence of induced NO release.
A Unified Continuous Flow Assembly‐Line Synthesis of Highly Substituted Pyrazoles and Pyrazolines
Authors: Britton Joshua , Jamison Timothy F. 
Published: May 2017

AbstractA rapid and modular continuous flow synthesis of highly functionalized fluorinated pyrazoles and pyrazolines has been developed. Flowing fluorinated amines through sequential reactor coils mediates diazoalkane formation and [3+2] cycloaddition to generate more than 30 azoles in a telescoped fashion. Pyrazole cores are then sequentially modified through additional reactor modules performing N‐alkylation and arylation, deprotection, and amidation to install broad molecular diversity in short order. Continuous flow synthesis enables the safe handling of diazoalkanes at elevated temperatures, and the use of aryl alkyne dipolarphiles under catalyst‐free conditions. This assembly‐line synthesis provides a flexible approach for the synthesis of agrochemicals and pharmaceuticals, as demonstrated by a four‐step, telescoped synthesis of measles therapeutic, AS‐136A, in a total residence time of 31.7 min (1.76 g h−1).
Theoretical Treatment of CH3NH3PbI3 Perovskite Solar Cells
Authors: Yun Sining , Zhou Xiao , Even Jacky , Hagfeldt Anders 
Published: May 2017

AbstractHybrid halide perovskite solar cells (PSCs) giving over 22 % power conversion efficiencies (PCEs) have attracted considerable attention. Although perovskite plays a significant role in the operation of PSCs, the fundamental theories associated with perovskites have not been resolved in spite of the increase in research. In this Minireview, we assess the current understanding, based on the first‐principles calculations, of structural and electronic properties, defects, ionic diffusion, and shift current for CH3NH3PbI3 perovskite, and the effect of ionic transport on the hysteresis of current–voltage curves in PSCs. The shift current connected to the possible presence of ferroelectricity is also discussed. The current state‐of‐the‐art and some open questions regarding PSCs are also highlighted, and the benefits, challenges, and potentials of perovskite for use in PSCs are stressed.
Control of Product Distribution and Mechanism by Ligation and Electric Field in the Thermal Activation of Methane
Authors: Yue Lei , Li Jilai , Zhou Shaodong , Sun Xiaoyan , Schlangen Maria , Shaik Sason , Schwarz Helmut 
Published: May 2017

AbstractAn unexpected mechanistic switch as well as a change of the product distribution in the thermal gas‐phase activation of methane have been identified when diatomic [ZnO].+ is ligated with acetonitrile. Theoretical studies suggest that a strong metal–carbon attraction in the pristine [ZnO].+ species plays an important role in the rebound of the incipient CH3. radical to the metal center, thus permitting the competitive generation of CH3., OH., and CH3OH. This interaction is drastically weakened by a single CH3CN ligand. As a result, upon ligation the proton‐coupled single electron transfer that prevails for [ZnO].+/CH4 switches to the classical hydrogen‐atom‐transfer process, thus giving rise to the exclusive expulsion of CH3.. This ligand effect can be modeled quite well by an oriented external electric field of a negative point charge.