bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ion kinetic properties in Mercury's pre‐midnight plasma sheet
Authors: Gershman Daniel J. , Slavin James A. , Raines Jim M. , Zurbuchen Thomas H. , Anderson Brian J. , Korth Haje , Baker Daniel N. , Solomon Sean C. 
Published: June 2014

AbstractWith data from the Fast Imaging Plasma Spectrometer sensor on the MErcury Surface, Space ENvironment, GEochemistry, and Ranging spacecraft, we demonstrate that the average distributions for both solar wind and planetary ions in Mercury's pre‐midnight plasma sheet are well‐described by hot Maxwell‐Boltzmann distributions. Temperatures and densities of the H+‐dominated plasma sheet, in the ranges ~1–10 cm−3 and ~5–30 MK, respectively, maintain thermal pressures of ~1 nPa. The dominant planetary ion, Na+, has number densities about 10% that of H+. Solar wind ions retain near‐solar‐wind abundances with respect to H+ and exhibit mass‐proportional ion temperatures, indicative of a reconnection‐dominated heating in the magnetosphere. Conversely, planetary ion species are accelerated to similar average energies greater by a factor of ~1.5 than that of H+. This energization is suggestive of acceleration in an electric potential, consistent with the presence of a strong centrifugal acceleration process in Mercury's magnetosphere.
Pyroclast Tracking Velocimetry: A particle tracking velocimetry‐based tool for the study of Strombolian explosive eruptions
Authors: Gaudin Damien , Moroni Monica , Taddeucci Jacopo , Scarlato Piergiorgio , Shindler Luca 
Published: June 2014

AbstractImage‐based techniques enable high‐resolution observation of the pyroclasts ejected during Strombolian explosions and drawing inferences on the dynamics of volcanic activity. However, data extraction from high‐resolution videos is time consuming and operator dependent, while automatic analysis is often challenging due to the highly variable quality of images collected in the field. Here we present a new set of algorithms to automatically analyze image sequences of explosive eruptions: the pyroclast tracking velocimetry (PyTV) toolbox. First, a significant preprocessing is used to remove the image background and to detect the pyroclasts. Then, pyroclast tracking is achieved with a new particle tracking velocimetry algorithm, featuring an original predictor of velocity based on the optical flow equation. Finally, postprocessing corrects the systematic errors of measurements. Four high‐speed videos of Strombolian explosions from Yasur and Stromboli volcanoes, representing various observation conditions, have been used to test the efficiency of the PyTV against manual analysis. In all cases, >106 pyroclasts have been successfully detected and tracked by PyTV, with a precision of 1 m/s for the velocity and 20% for the size of the pyroclast. On each video, more than 1000 tracks are several meters long, enabling us to study pyroclast properties and trajectories. Compared to manual tracking, 3 to 100 times more pyroclasts are analyzed. PyTV, by providing time‐constrained information, links physical properties and motion of individual pyroclasts. It is a powerful tool for the study of explosive volcanic activity, as well as an ideal complement for other geological and geophysical volcano observation systems.
Time‐averaged discharge rate of subaerial lava at Kīlauea Volcano, Hawai‘i, measured from TanDEM‐X interferometry: Implications for magma supply and storage during 2011–2013
Authors: Poland Michael P. 
Published: June 2014

AbstractDifferencing digital elevation models (DEMs) derived from TerraSAR add‐on for Digital Elevation Measurements (TanDEM‐X) synthetic aperture radar imagery provides a measurement of elevation change over time. On the East Rift Zone (EZR) of Kīlauea Volcano, Hawai‘i, the effusion of lava causes changes in topography. When these elevation changes are summed over the area of an active lava flow, it is possible to quantify the volume of lava emplaced at the surface during the time spanned by the TanDEM‐X data—a parameter that can be difficult to measure across the entirety of an ~100 km2 lava flow field using ground‐based techniques or optical remote sensing data. Based on the differences between multiple TanDEM‐X‐derived DEMs collected days to weeks apart, the mean dense‐rock equivalent time‐averaged discharge rate of lava at Kīlauea between mid‐2011 and mid‐2013 was approximately 2 m3/s, which is about half the long‐term average rate over the course of Kīlauea's 1983–present ERZ eruption. This result implies that there was an increase in the proportion of lava stored versus erupted, a decrease in the rate of magma supply to the volcano, or some combination of both during this time period. In addition to constraining the time‐averaged discharge rate of lava and the rates of magma supply and storage, topographic change maps derived from space‐based TanDEM‐X data provide insights into the four‐dimensional evolution of Kīlauea's ERZ lava flow field. TanDEM‐X data are a valuable complement to other space‐, air‐, and ground‐based observations of eruptive activity at Kīlauea and offer great promise at locations around the world for aiding with monitoring not just volcanic eruptions but any hazardous activity that results in surface change, including landslides, floods, earthquakes, and other natural and anthropogenic processes.
Global multiple tropopause features derived from COSMIC radio occultation data during 2007 to 2012
Authors: Xu Xiaohua , Gao Pan , Zhang Xiaohong 
Published: June 2014

AbstractThe spatiotemporal structure of the climatology of multiple tropopauses (MTs) is presented in this paper by using the temperature profiles from the Global Positioning System radio occultation measurements from the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) mission between January 2007 and December 2012. Various climatological characteristics about MTs are studied, including the relationship between the occurrence of double tropopauses (DTs) and jet streams, the interannual variation and the trends of the occurrence of DTs, the seasonal and geographical variations of the occurrence of MTs, and the meridional distributions of the features of MTs in different seasons. Our results agree well with those of earlier studies based on other data sets. In addition, we find some new MT features. A global increase of the occurrence of DTs of about 0.15% ± 0.09% yr−1 (0.13% ± 0.09% yr−1) is found between 2007 and 2012 including (excluding) the sampling errors, respectively. There is an increasing trend of the occurrence of DTs in the extratropics, especially in the subtropics in both hemispheres, and a decreasing trend in the tropics. We also find that the maximum seasonal variation of the occurrence of DTs is located between 30°N and 40°N, which is much stronger than that in the Southern Hemisphere. The occurrence of DTs is much lower from the winter of 2009 to the spring of 2010 than during the same time period of other years.
Damping of glacial‐interglacial cycles from anthropogenic forcing
Authors: Haqq‐Misra Jacob 
Published: June 2014

AbstractClimate variability over the past million years shows a strong glacial‐interglacial cycle of ∼100,000 years as a combined result of Milankovitch orbital forcing and climatic resonance. It has been suggested that anthropogenic contributions to radiative forcing may extend the length of the present interglacial, but the effects of anthropogenic forcing on the periodicity of glacial‐interglacial cycles has received little attention. Here I demonstrate that moderate anthropogenic forcing can act to damp this 100,000 year cycle and reduce climate variability from orbital forcing. Future changes in solar insolation alone will continue to drive a 100,000 year climate cycle over the next million years, but the presence of anthropogenic warming can force the climate into an ice‐free state that only weakly responds to orbital forcing. Sufficiently strong anthropogenic forcing that eliminates the glacial‐interglacial cycle may serve as an indication of an epoch transition from the Pleistocene to the Anthropocene.
Rapid and large‐scale separation of magnetic nanoparticles by low‐field permanent magnet with gas assistance
Authors: Li Wensong , Yang Liangrong , Liu Huizhou , Li Xiaopei , Liu Zhini , Wang Fuchun , Sui Na , Xiao Chuanxu 
Published: June 2014

SignificanceBubbles can be used to greatly improve the speed of magnetic separation (MS) and overcome the limitation of magnetic force on the capture distance, making low‐field MS highly efficient and easily scalable. This novel method leads to the development of a medium‐free continuous gas‐assisted magnetic separator on small pilot scale using low‐field permanent magnet. This separator is demonstrated highly efficient for recovery of proteins‐loaded magnetic nanoparticles from large volume biosuspension. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3101–3106, 2014
Demographic transitions and migration in prehistoric East/Southeast Asia through the lens of nonmetric dental traits
Authors: Matsumura Hirofumi , Oxenham Marc F. 
Published: June 2014

ABSTRACTThe aim of this study is to examine and assess the nonmetric dental trait evidence for the population history of East and Southeast Asia and, more specifically, to test the two‐layer hypothesis for the peopling of Southeast Asia. Using a battery of 21 nonmetric dental traits we examine 7,247 individuals representing 58 samples drawn from East and Southeast Asian populations inhabiting the region from the late Pleistocene, through the Neolithic, Bronze Age, Iron Age, and into the historic and modern periods. The chief data reduction technique is a neighbor‐joining tree generated from the triangular matrix of mean measure of divergence values. Principal findings indicated a major dichotomization of the dataset into (1) an early Southeast Asian sample with close affinities to modern Australian and Melanesian populations and (2) a very distinct grouping of ancient and modern Northeast Asians. Distinct patterns of clinal variation among Neolithic and post‐Neolithic Mainland Southeast Asian samples suggest a center to periphery spread of genes into the region from Northeast Asia. This pattern is consistent with archaeological and linguistic evidence for demic diffusion that accompanied agriculturally driven population expansion in the Neolithic. Later Metal Age affinities between Island and Mainland coastal populations with Northeast Asian series is likely a consequence of a South China Sea interaction sphere operating from at least 500 BCE, if not from the Neolithic. Such results provide extensive support for the two‐layer hypothesis to account for the population history of the region. Am J Phys Anthropol 155:45–65, 2014. © 2014 Wiley Periodicals, Inc.
Functional anatomy of subthalamic nucleus stimulation in Parkinson disease
Authors: Eisenstein Sarah A. , Koller Jonathan M. , Black Kathleen D. , Campbell Meghan C. , Lugar Heather M. , Ushe Mwiza , Tabbal Samer D. , Karimi Morvarid , Hershey Tamara , Perlmutter Joel S. , Black Kevin J. 
Published: June 2014

ObjectiveWe developed a novel method to map behavioral effects of deep brain stimulation (DBS) across a 3‐dimensional brain region and to assign statistical significance after stringent type I error correction. This method was applied to behavioral changes in Parkinson disease (PD) induced by subthalamic nucleus (STN) DBS to determine whether these responses depended on anatomical location of DBS.MethodsFifty‐one PD participants with STN DBS were evaluated off medication, with DBS off and during unilateral STN DBS with clinically optimized settings. Dependent variables included DBS‐induced changes in Unified Parkinson Disease Rating Scale (UPDRS) subscores, kinematic measures of bradykinesia and rigidity, working memory, response inhibition, mood, anxiety, and akathisia. Weighted t tests at each voxel produced p images showing where DBS most significantly affected each dependent variable based on outcomes of participants with nearby DBS. Finally, a permutation test computed the probability that this p image indicated significantly different responses based on stimulation site.ResultsMost motor variables improved with DBS anywhere in the STN region, but several motor, cognitive, and affective responses significantly depended on precise location stimulated, with peak p values in superior STN/zona incerta (quantified bradykinesia), dorsal STN (mood, anxiety), and inferior STN/substantia nigra (UPDRS tremor, working memory).InterpretationOur method identified DBS‐induced behavioral changes that depended significantly on DBS site. These results do not support complete functional segregation within STN, because movement improved with DBS throughout, and mood improved with dorsal STN DBS. Rather, findings support functional convergence of motor, cognitive, and limbic information in STN. Ann Neurol 2014;76:279–295
Half‐submerged cultivation method for the microbial desulfurization of waste latex rubber
Authors: Yao Chu , Zhao Suhe , Hu Minghan , Wang Bingwu , Zhang Liqun 
Published: June 2014

ABSTRACTThe common method for microbial desulfurization is the submerged cultivation method. However, its cost is high because of the high consumption of the medium. To cut costs and improve the desulfurization effect, the new half‐submerged cultivation method was used in the microbial desulfurization of waste latex rubber (WLR) by Sphingomonas species With this method, much more WLR was added per unit volume of the culture medium to be desulfurized, and the desulfurization process was done without stirring. The technical conditions, such as the addition of WLR, the addition of polysorbate 80 (Tween 80), and the desulfurization time, for the half‐submerged cultivation method were studied, and its desulfurization effect was compared with that of the traditional submerged cultivation method. The results show that the optimum conditions for the half‐submerged cultivation method were the addition of 40% w/v WLR in the medium without Tween 80 and desulfurization for 10 days. The X‐ray photoelectron spectroscopy and Fourier transform infrared spectroscopy results demonstrate that the decreases in the content of sulfur, SC bonds, and SS bonds on the surface of WLR after desulfurization by the half‐submerged cultivation method were greater than those after desulfurization by the submerged cultivation method. The composite of waste latex rubber desulfurized by the submerged cultivation method (SDWLR) and styrene–butadiene rubber (SBR) had better mechanical properties than the composite of waste latex rubber desulfurized by the half‐submerged cultivation method (HDWLR) and SBR. Scanning electron microscopy photographs showed that the combinations of HDWLR and the matrix were better than those of SDWLR and the matrix. Compared with the submerged cultivation method, the half‐submerged cultivation method not only reduced the cost of desulfurization but also improved the desulfurization effect. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41039.
Patterned polymer surfaces with wetting contrast prepared by polydopamine modification
Authors: Zhang Liang , Yu Haizhu , Zhao Ning , Dang Zhi‐Min , Xu Jian 
Published: June 2014

ABSTRACTPatterned polymer surfaces with contrasting wettability are prepared by polydopamine (PD) modification. The fabrication process involves spraying dopamine solution droplets on hydrophobic polymer surfaces and PD deposition derived from the oxidative polymerization of dopamine. Each dopamine solution droplets functions as microreactor leading to the formation of patterned PD thin films on the solid/liquid interfaces. Multiple kinds of polymer substrates, including polypropylene, polystyrene, polycarbonate, polyethylene and polytetrafluoroethylene, are endowed with PD patterns using this method. Two types of wetting behaviors are achieved in relation to the micro morphology of the substrates. If smooth or porous substrates are used, the as‐formed film exhibited hydrophilic‐hydrophobic pattern. When a hierarchical‐structured film is used, the uncoated and coated regions have similar static wettability but different dynamic wetting behavior. This PD modification method is also proved to be suitable for flexible and curved surfaces. The results along with the fact that PD could deposit on virtually any surfaces makes this method find wide practical applications in many fields. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41057.
Poly(lactic acid) stereocomplex formation: Application to PLA rheological property modification
Authors: Saeidlou Sajjad , Huneault Michel A. , Li Hongbo , Park Chul B. 
Published: June 2014

ABSTRACTPoly(lactic acid) (PLA) stereocomplex formation in isothermal conditions in the absence and presence of a nucleating agent was studied from a rheological point of view due to sensitivity of viscoelastic properties to structural changes during this process. PDLA was melt blended in low concentrations with PLLA to produce a stereocomplex. Amorphous samples were prepared and crystallization was carried out in a rheometer at high temperatures to simulate melt processing conditions. Stereocomplexation was explored over time by measuring rheological parameters in small deformation oscillatory shear mode at a low frequency using parallel plate geometry. Kinetic data obtained by this means was compared to data from calorimetric studies, showing a different trend depending on the characterization method. Moreover, after the completion of crystallization, final crystalline structure was probed over a wide range of frequencies to investigate the rheological modification role of PDLA on PLLA major component. Differences in rheological characteristics of asymmetric PLLA/PDLA blends as compared to neat PLLA were associated to the structural changes happening because of the formation of the stereocomplex. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41073.
Influence of glycerides–xanthan gum synergy on their performance as lubricants for water‐based drilling fluids
Authors: Nunes Denise Gentili , da Silva Andréia de P.M. , Cajaiba João , Pérez‐Gramatges Aurora , Lachter Elizabeth Roditi , Nascimento Regina Sandra Veiga 
Published: June 2014

ABSTRACTWater‐based fluids for drilling wells are an environmentally friendly alternative to oil‐based formulations typically used in the oil industry. Aqueous mixtures of nonionic monoglyceride surfactants (C6, C8, C10, C12, and C18 carbon chains) and xanthan gum (XG) were investigated with that purpose, correlating their lubricity and solubility in water, as well as using surface tension and contact angle measurements. The results showed that monoglycerides behave as excellent lubricants in water, with a steady decrease of the friction coefficient as the hydrocarbon chain length increased. Monoglycerides were able to reduce the friction coefficient even further when used in XG suspensions, suggesting that they are probably forming a complex with the polysaccharide that shows a synergy toward their performance as lubricants. Experiments of adsorption onto iron oxide nanoparticles also produced evidence of the interaction between these molecules, which favors their adsorption on the metal surface. These results indicate that interactions occurring in solution between the surfactants and the polysaccharide are crucial in the mechanism of action of these mixtures as lubricants in water‐based drilling fluids. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41085.
The preparation and analysis of chlorinated ethylene vinyl acetate copolymer as coating film in gas‐solid phase
Authors: Jing Zhao , Liu Lijuan , Zhang Shukai , Zhao Jiruo , Feng Ying 
Published: June 2014

ABSTRACTIn this article, the feasibility of preparing chlorinated ethylene vinyl acetate copolymer (CEVA) in gas–solid phase is investigated. Furthermore, the structure of the chlorination product and its performance as a coating material are also analyzed. Both the molecular structure and crystallinity of the product are well studied with various characterization methods, including 1H‐NMR, Fourier transform infrared, gel permeation chromatography, differential scanning calorimeter, and so forth. The results show that the chlorination of EVA in gas–solid phase is feasible and the chlorine content of CEVA can be made over 60%. It is also found that when the chlorine content is low, chlorination can easily occur in ethylene section but rarely happens in vinyl acetate section. Nevertheless, when the chlorine content of CEVA rises over 35%, CH in the vinyl acetate section is also found chlorinated. The removal of hydrogen chloride is induced during chlorination, producing double bonds in the main chain. Besides, the trace of CCl2 structure can also be found in the chain of CEVA. After chlorination, the crystallization will change and is negatively correlated with chlorine content. As the film forming material for coating, CEVA has its best performance with 50% chlorine content. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41093.
Influences of processing on the phase transition and crystallization of polypropylene cast films
Authors: Xu Meng , Zhang Shijun , Liang Jieying , Quan Hui , Liu Jianye , Shi Hongwei , Gao Dali , Liu Jie 
Published: June 2014

ABSTRACTPhase transition and changes of properties of isotactic polypropylene (i‐PP) cast films with the processing conditions have been investigated by wide‐angle X‐ray diffraction, two‐dimensional small‐angle X‐ray scattering, and atomic force microscopy. It was found that chill roll temperature was a major factor, which influenced the formation of mesomorphic phase and its transition to spherulitic structure. Only mesomorphic phase was observed in the films produced under a chill roll temperature of below 40°C. When the roll temperature was increased to 60°C, mesomorphic phase coexisted with spherulitic crystal structure, and totally transformed to monoclinic structure at the roll temperature of 80°C. Differential scanning calorimetry, tensile, and optical tests were also performed on the films. The results showed that the observed structure changes were closely related to the thermal behavior, tensile, and optical properties of the PP films. The influence of die temperature on the films was also discussed, but the effect was much less than chill roll temperature. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41100.