bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evolution of stratospheric sulfate aerosol from the 1991 Pinatubo eruption: Roles of aerosol microphysical processes
Authors: Sekiya T. , Sudo K. , Nagai T. 
Published: February 2016

AbstractThis study investigates the role of aerosol microphysics in stratospheric sulfate aerosol changes after the 1991 Mount Pinatubo eruption using an atmospheric general circulation model that is coupled interactively with a chemistry module and a modal aerosol microphysical module with three modes. Our model can reproduce the global mean stratospheric aerosol optical depth (SAOD) observed by the Stratospheric Aerosol and Gas Experiment (SAGE) II during June 1991 to January 1993. The model underestimates the observed SAOD before the eruption and after January 1993. The model also underestimates the integrated backscatter coefficient observed by ground‐based lidar at Tsukuba, Naha, and Lauder. The modeled effective radius becomes larger (about 0.5 μm) and agrees with the balloon‐borne measurements at Laramie, Wyoming (41°N, 105°W). We further investigate effects of the inclusion of evaporation along with the condensation processes and the inclusion of van der Waals and viscous forces in the coagulation processes. The inclusion of evaporation along with the condensation processes reduces the global mean effective radius by up to 0.04 μm and increases the global burden of stratospheric sulfate aerosols (about 15% in late 1993). The inclusion of van der Waals and viscous forces in the coagulation processes increases the global mean effective radius by up to 0.06–0.07 μm and decreases the global burden (15–30% in late 1993). The effects of van der Waals and viscous forces differ between two schemes. However, we do not conclude which simulation is superior because all simulations fall within error bars.
Comparison of the Hazard Mapping System (HMS) fire product to ground‐based fire records in Georgia, USA
Authors: Hu Xuefei , Yu Chao , Tian Di , Ruminski Mark , Robertson Kevin , Waller Lance A. , Liu Yang 
Published: February 2016

AbstractBiomass burning has a significant and adverse impact on air quality, climate change, and various ecosystems. The Hazard Mapping System (HMS) detects fires using data from multiple satellite sensors in order to maximize its fire detection rate. However, to date, the detection rate of the HMS fire product for small fires has not been well studied, especially using ground‐based fire records. This paper utilizes the 2011 fire information compiled from ground observations and burn authorizations in Georgia to assess the comprehensiveness of the HMS active fire product. The results show that detection rates of the hybrid HMS increase substantially by integrating multiple satellite instruments. The detection rate increases dramatically from 3% to 80% with an increase in fire size from less than 0.02 km2 to larger than 2 km2, resulting in detection of approximately 12% of all recorded fires which represent approximately 57% of the total area burned. The spatial pattern of detection rates reveals that grid cells with high detection rates are generally located in areas where large fires occur frequently. The seasonal analysis shows that overall detection rates in winter and spring (12% and 13%, respectively) are higher than those in summer and fall (3% and 6%, respectively), mainly because of higher percentages of large fires (>0.19 km2) that occurred in winter and spring. The land cover analysis shows that detection rates are 2–7 percentage points higher in land cover types that are prone to large fires such as forestland and shrub land.
Five millennia of surface temperatures and ice core bubble characteristics from the WAIS Divide deep core, West Antarctica
Authors: Fegyveresi John M. , Alley Richard B. , Fitzpatrick Joan J. , Cuffey Kurt M. , McConnell Joseph R. , Voigt Donald E. , Spencer Matthew K. , Stevens Nathan T. 
Published: February 2016

AbstractBubble number densities from the West Antarctic Ice Sheet (WAIS) Divide deep core in West Antarctica record relatively stable temperatures during the middle Holocene followed by late Holocene cooling. We measured bubble number density, shape, size, and arrangement on new samples of the main WAIS Divide deep core WDC06A from ~580 m to ~1600 depth. The bubble size, shape, and arrangement data confirm that the samples satisfy the requirements for temperature reconstructions. A small correction for cracks formed after core recovery allows extension of earlier work through the “brittle ice” zone, and a site‐specific calibration reduces uncertainties. Using an independently constructed accumulation rate history and a steady state bubble number density model, we determined a temperature reconstruction that agrees closely with other independent estimates, showing a stable middle Holocene, followed by a cooling of ~1.25°C in the late Holocene. Over the last ~5 millennia, accumulation has been higher during warmer times by ~12%°C−1, somewhat stronger than for thermodynamic control alone, suggesting dynamic processes.
Spatiotemporal patterns of water table fluctuations and evapotranspiration induced by riparian vegetation in a semiarid area
Authors: Yue Weifeng , Wang Tiejun , Franz Trenton E. , Chen Xunhong 
Published: February 2016

AbstractGroundwater evapotranspiration (ETg) links various ecohydrological processes and is an important component in regional water budgets. In this study, an extensive monitoring network was established in a semiarid riparian area to investigate various controls on the spatiotemporal pattern of water table fluctuations (WTFs) and ETg induced by riparian vegetation. Along a vegetation gradient (∼1200 m), diurnal WTFs were observed during a growing season in areas covered by woody species (Populus sect. Aigeiros and Juniperus virginiana) and wet slough vegetation (Panicum virgatum and Bromus inermis) with deeper root systems; whereas, no diurnal WTFs were found in the middle section with shallower‐rooted grasses (Poa pratensis and Carex sp.). The occurrence of diurnal WTFs was related to temperature‐controlled plant phenology at seasonal scales and to radiation at subdaily scales. Daily ETg in the mid‐growing season was calculated using the White method. The results revealed that depth to water table (DTWT) was the dominant control on ETg, followed by potential evapotranspiration (ETp). By combining the effects of DTWT and ETp, it was found that at shallower depths, ETg was more responsive to changes in ETp, due to the closer linkage of land surface processes with shallower groundwater. Finally, exponential relationships between ETg/ETp and DTWT were obtained at the study site, although those relationships varied considerably across the sites. This study demonstrates the complex interactions of WTFs and ETg with surrounding environmental variables and provides further insight into modeling ETg over different time scales and riparian vegetation.
Modeling of Store Gletscher's calving dynamics, West Greenland, in response to ocean thermal forcing
Authors: Morlighem M. , Bondzio J. , Seroussi H. , Rignot E. , Larour E. , Humbert A. , Rebuffi S. 
Published: February 2016

AbstractGlacier‐front dynamics is an important control on Greenland's ice mass balance. Warmer ocean waters trigger ice‐front retreats of marine‐terminating glaciers, and the corresponding loss in resistive stress leads to glacier acceleration and thinning. Here we present an approach to quantify the sensitivity and vulnerability of marine‐terminating glaciers to ocean‐induced melt. We develop a plan view model of Store Gletscher that includes a level set‐based moving boundary capability, a parameterized ocean‐induced melt, and a calving law with complete and precise land and fjord topographies to model the response of the glacier to increased melt. We find that the glacier is stabilized by a sill at its terminus. The glacier is dislodged from the sill when ocean‐induced melt quadruples, at which point the glacier retreats irreversibly for 27 km into a reverse bed. The model suggests that ice‐ocean interactions are the triggering mechanism of glacier retreat, but the bed controls its magnitude.
Surface temperature dependence of tropical cyclone‐permitting simulations in a spherical model with uniform thermal forcing
Authors: Merlis Timothy M. , Zhou Wenyu , Held Isaac M. , Zhao Ming 
Published: February 2016

AbstractTropical cyclone (TC)‐permitting general circulation model simulations are performed with spherical geometry and uniform thermal forcing, including uniform sea surface temperature (SST) and insolation. The dependence of the TC number and TC intensity on SST is examined in a series of simulations with varied SST. The results are compared to corresponding simulations with doubly periodic f‐plane geometry, rotating radiative convective equilibrium. The turbulent equilibria in simulations with spherical geometry have an inhomogenous distribution of TCs with the density of TCs increasing from low to high latitudes. The preferred region of TC genesis is the subtropics, but genesis shifts poleward and becomes less frequent with increasing SST. Both rotating radiative convective equilibrium and spherical geometry simulations have decreasing TC number and increasing TC intensity as SST is increased.
Variability and future decreases in winter wave heights in the Western North Pacific
Authors: Shimura Tomoya , Mori Nobuhito , Hemer Mark A. 
Published: February 2016

AbstractOcean surface wave climate is a key consideration for a number of industrial and environmental systems, both offshore and at the coast. A dynamical spectral wave model forced with global climate models (GCMs) was used to produce an ensemble of simulations of both historical and projected future wave climate. To estimate the uncertainty of the projected wave climate, we combined a multimember ensemble experiment using MRI‐AGCM3.2H with a multimodel ensemble using eight CMIP5 GCMs. Future changes in wintertime wave heights from the end of the 20th to the 21st century were analyzed. Projected decreases in wave heights over the Western North Pacific are highly consistent among the ensemble. The future decreases in wave heights are significantly related to changes in the West Pacific pattern. Both locally generated waves and remotely generated swells are important to estimate future changes in the wave climate on a regional scale.
Tin‐Catalyzed Selective Reductive Hydroamination of Alkynes for the Synthesis of Tertiary Amines
Authors: Nayal Onkar S. , Thakur Maheshwar S. , Kumar Manoranjan , Sharma Sushila , Kumar Neeraj 
Published: February 2016

AbstractA unique preference of tin(II) for aniline activation is disclosed. In the present work tin(II) triflate‐catalyzed highly selective Markovnikov reductive hydroamination of internal as well as terminal alkynes is reported. The mechanistic study revealed the involvement of two steps in one pot wherein alkyne reduces to corresponding alkene in presence of PMHS as reducing agent followed by hydroamination of alkene. A broad range of alkynes transformed into tertiary amines with good to excellent yield. This method is equally applicable in synthesis of secondary amines.magnified image
Association of genetic variants with skin pigmentation phenotype among populations of west Maharashtra, India
Authors: Jonnalagadda Manjari , Norton Heather , Ozarkar Shantanu , Kulkarni Shaunak , Ashma Richa 
Published: February 2016

ObjectivesSouth Asians exhibit extensive variation in skin melanin index (MI) which is observed across the broader region of South Asia as well as within restricted geographic regions. However, the genetic variants associated with variation in the skin pigmentation phenotype are poorly understood in these populations. The present study examines the association between MI measures and genetic variants from 5 candidate pigmentation genes among 533 individuals representing 6 populations of West Maharashtra.MethodsAssociations between five single nucleotide polymorphisms (SNPs) known to play a role in pigmentation (rs1426654‐SLC24A5, rs1042602‐TYR, rs16891982‐SLC45A2, rs6058017‐ASIP, and rs642742‐KITLG) and MI measures were tested using standard one‐way analysis of variance (ANOVA) within each population. Multiple linear regression was used to test the effects of these SNPs in the full West Maharashtra sample using sex, age, and population or social group as covariates.Resultsrs1426654 showed significant association with MI in all six study populations (P < 0.01). Association tests using sex, age, and population as covariates showed rs1426654 and rs1042602 to be significantly (P < 0.01) associated with lighter skin pigmentation in West Maharashtra as a whole. By contrast, when social group was added as a covariate instead of population, rs1426654, rs1042602, and rs16891982 were significantly (P < 0.01) associated with lighter skin pigmentation.ConclusionsOnly rs1426654 is significantly associated with MI in each individual population; however, rs1426654, rs1042602, and rs16891982 are significantly associated with pigmentation in the broader West Maharashtra region after controlling for population and social group, with rs1426654 (SLC24A5) explaining the majority of the observed variation. Am. J. Hum. Biol. 28:610–618, 2016. © 2016 Wiley Periodicals, Inc.
Efficient Synthesis of Indole Derivatives via Tandem Cyclization Catalyzed by Magnetically Recoverable Palladium/Magnetite (Pd‐Fe3O4) Nanocrystals
Authors: Kwon Jungmin , Chung Jooyoung , Byun Sangmoon , Kim B. Moon 
Published: February 2016

AbstractA magnetically recyclable Pd‐Fe3O4 heterodimeric nanocrystal system has been utilized as a catalyst for an efficient synthesis of 2‐substituted indoles from 2‐haloanilines. The synthesis involves the Sonogashira coupling reaction of a 2‐haloaniline and an alkyne followed by the tandem cyclization of the resulting Sonogashira product to give indole derivatives in the presence of 1 mol % of Pd‐Fe3O4 nanocrystals and one equivalent of CuI. The Pd‐Fe3O4 nanocrystals were recovered with an external magnet and used up to ten times without loss of their catalytic activity.
Capture CO2 from Ambient Air Using Nanoconfined Ion Hydration
Authors: Shi Xiaoyang , Xiao Hang , Lackner Klaus S. , Chen Xi 
Published: February 2016

AbstractWater confined in nanoscopic pores is essential in determining the energetics of many physical and chemical systems. Herein, we report a recently discovered unconventional, reversible chemical reaction driven by water quantities in nanopores. The reduction of the number of water molecules present in the pore space promotes the hydrolysis of CO32− to HCO3− and OH−. This phenomenon led to a nano‐structured CO2 sorbent that binds CO2 spontaneously in ambient air when the surrounding is dry, while releasing it when exposed to moisture. The underlying mechanism is elucidated theoretically by computational modeling and verified by experiments. The free energy of CO32− hydrolysis in nanopores reduces with a decrease of water availability. This promotes the formation of OH−, which has a high affinity to CO2. The effect is not limited to carbonate/bicarbonate, but is extendable to a series of ions. Humidity‐driven sorption opens a new approach to gas separation technology.
New polymer to enhance the permanent memory effect of polymer dispersed liquid crystal films
Authors: Mouquinho Ana , Luís Nélia , Sotomayor João 
Published: February 2016

ABSTRACTConventional polymer dispersed liquid crystals (PDLC) are devices with recognized applications. New PDLCs with permanent memory effect (PME) can be used as digital memory devices. The synthesis and characterization of a new monomer [pentaerythritoltetramethacrylate (PE4MA)] is here described. A PDLC was produced using the synthesized monomer (PE4MA) copolymerized with commercially available monomethacrylate oligomer poly(propyleneglycol) methacrylate (PPGMA) and 70% (w/w) liquid crystal (E7), showing 98% permanent memory effect, with 72% memory state contrast (MSC) and an electric field required to achieve 90% of the maximum transmittance (E90) of 3 V µm−1. The synthesized monomer (PE4MA) copolymerized with PPGMA seems to be a prospective material for preparation of PDLC with permanent memory effect with a view to application for digital memory devices based on write‐read‐erase cycles. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43482.
Synthesis, characterization, and curing behavior of carborane‐containing benzoxazine resins with excellent thermal and thermo‐oxidative stability
Authors: Qi Shicheng , Wang Hongrui , Han Guo , Yang Zhen , Zhang Xiao A , Jiang Shengling , Lu Yafei 
Published: February 2016

ABSTRACTTwo benzoxazine precursors bearing carborane moiety (1 and 2) were designed and synthesized successfully by the Mannich reaction of corresponding carborane bisphenol (3 and 4) with aniline and formaldehyde in 1,4‐dioxane. The obtained precursors were characterized by using multiple spectroscopic techniques including GPC, FTIR, 1H NMR, 13C NMR, and 11B NMR. Nonisothermal DSC studies showed that precursor 1 owned lower apparent activation energies (Ea) than 2. The optimum curing processes of benzoxazine precursors were also obtained on the basis of DSC data. TGA analyses manifested that the incorporation of carborane moiety endowed the obtained benzoxazine resins (cured 1 and 2) with excellent thermal stability and unique thermo‐oxidative stability. The Td data showed that the initial degradation of both cured 1 and 2 under nitrogen and air was postponed to some extent owing to the shielding effect of carborane moiety on adjacent organic fragments. At higher temperature three‐dimensional polymer networks with B‐O‐B and B–C linkages were formed as chars by the reaction of carborane cage with atmospheric moisture, degradation products such as phenolic hydroxyl, and oxygen (under air). Under nitrogen this network hindered the motion of radicals formed at elevated temperature and thus inhibited further polymer degradation processes. While under air, the formed boron‐rich networks could hardly be further oxidized into carbon dioxide so that the carborane‐containing benzoxazine resins also showed very high char yields. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43488.
Effects of processing parameters on the properties of microwave‐devulcanized ground tire rubber/polyethylene dynamically revulcanized blends
Authors: Danielli Bastos de Sousa Fabiula , Scuracchio Carlos Henrique , Hu Guo‐Hua , Hoppe Sandrine 
Published: February 2016

ABSTRACTThis work aimed to evaluate the effects of processing parameters on properties of dynamically revulcanized blends based on 60 wt % of devulcanized ground tire rubber (GTR) and 40 wt % of high density polyethylene (HDPE). Devulcanization of the GTR was carried out in a system comprised of a conventional microwave oven adapted with a motorized stirring system with speed control. The resulting devulcanized GTR contained 26 wt % soluble in toluene. It was processed with HDPE in a twin screw extruder to produce a dynamically revulcanized blend. Processing parameters such as screw speed and feeding mode were varied. Their effects were evaluated based on tensile, dynamic mechanical, thermal and rheological properties, as well as on morphology. The results show the importance of the processing parameters involved in the production of blends with dynamically revulcanized rubber phase in the extruder, and good match between the residence time of the rubber and its revulcanization kinetics. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2016,133, 43503.
Nonmonotonic piezoresistive effect in elastomeric composite films
Authors: Paliy M. , Trebicky T. , Guo Q. , Kobe B. , Suhan N. , Arsenault G. , Ferrari L. , Yang J. 
Published: February 2016

ABSTRACTWe compared the change of electrical resistance with elongation (piezoresistive effect) in thin films made of conductive multiwalled carbon nanotubes embedded in eight different elastomers. Two distinct forms of piezoresistive effect were observed: (i) in the “monotonic” (M) case, the film resistance always increased with the applied strain; (ii) the “nonmonotonic” (NM) case showed an initial increase in the resistance, while with further elongation the resistance began to decrease. By varying the amount of nitrile and/or styrene groups in the polymer matrix one can alter the piezoresistive effect qualitatively: composites with ∼25 wt % or more of nitrile or styrene functional side groups exhibited M piezoresistance, while others, with no, or methyl side groups only, showed NM piezoresistance. Influence of the second filler (either conductive carbon black or nonconductive nanoclay) in the ternary composites on the piezoresistive effect was explored. The possibility to modify the piezoresistive behavior of the conductive elastomer composites, for example, via chemical modification of the polymeric matrix, opens up a new venue for practical applications such as diverse types of sensors and, in NM case, complex dynamical systems (bistable elements, electromechanical oscillators, etc.) in the MEMS field. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2016,133, 43518.
The Skull of Phyllomedusa sauvagii (Anura, Hylidae)
Authors: Ruiz‐Monachesi Mario R. , Lavilla Esteban O. , Montero Ricardo 
Published: February 2016

ABSTRACTThe hylid genus Phyllomedusa comprises charismatic frogs commonly known as monkey, leaf or green frogs, and is the most diverse genus of the subfamily Phyllomedusinae, including about 31 species. Although there is some information about the anatomy of these frogs, little is known about the osteology. Here the adult skull of Phyllomedusa sauvagii, both articulated and disarticulated, is described and the intraspecific variation is reported. Additionally, cartilage associated with the adult skull, such as the nasal capsules, auditory apparatus, and hyobranchial apparatus, are included in the analysis. Further examination of disarticulated bones reveals their remarkable complexity, specifically in the sphenethmoid and of the oocipital region. The description of disarticulated bones is useful for the identification of fossil remains as well as providing morphological characteristics that are phylogenetically informative. When comparing the skull morphology with the available information of other species of the genus, Phyllomesusa sauvagii skull resembles more that of P. vaillantii and P. venusta than P. atelopoides. Anat Rec, 299:557–572, 2016. © 2016 Wiley Periodicals, Inc.
Fabrication of High‐Energy Li‐Ion Cells with Li4Ti5O12 Microspheres as Anode and 0.5 Li2MnO3⋅0.5 LiNi0.4Co0.2Mn0.4O2 Microspheres as Cathode
Authors: Dai Chenguang , Ye Jing , Zhao Shiyong , He Ping , Zhou Haoshen 
Published: February 2016

AbstractIn this work, we propose an effective way to prepare nanosized Li4Ti5O12 (LTO) microspheres and 0.5 Li2MnO3⋅0.5 LiNi0.4Co0.2Mn0.4O2 (NCM) microspheres by similar spray‐drying methods. Both obtained materials are accumulated by primary nanoparticles and show a spherical morphology with particle distribution of 10–20 μm. The LTO microspheres deliver a tap density of 1.04 g cm−3, while the tap density of NCM microspheres is 2.07 g cm−3, which means an enhanced volumetric energy density. The as‐prepared LTO microspheres have a reversible capacity of 170 mA h g−1 at 0.1 C and a capacity retention of 97 % after 250 cycles at 1 C. The NCM microspheres have an initial discharge capacity of 270 mA h g−1 with a corresponding Coulombic efficiency of 88 % at 0.03 C. Both materials show a relatively good rate capability. The Li4Ti5O12/0.5 Li2MnO3⋅0.5 LiNi0.4Co0.2Mn0.4O2 cells deliver a high cathode specific capacity of 273 mA h g−1 and good initial Coulombic efficiency of 88 % at 0.03 C, and can be developed for powering hybrid and plug‐in hybrid vehicles.