bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeled diurnally varying sea surface temperatures and their influence on surface heat fluxes
Authors: Weihs Rachel R. , Bourassa Mark. A. 
Published: May 2014

AbstractA diurnal warming model is used to create a new data set of global, diurnally varying sea surface temperatures (dSSTs) and surface turbulent heat fluxes over a 5 year period. The magnitude of diurnal warming is primarily a function of low wind speed and net heat flux. Differences between each of the surface turbulent fluxes with and without a diurnally varying SST are examined on hourly, daily, and seasonal time scales. Over a 2 month period, maximum averaged diurnal warming is as large as 0.3°C, and latent heat flux is underestimated by as much as 8 W/m2 in the Indian Ocean. They also exceed roughly 0.7°C and 10 W/m2, respectively, up to 25% of the total daytime in the Atlantic. A best‐case approach validation shows the model overestimates peak warming and underestimates the duration of the cycle, though the average error is quite small. The model is tested under a variety of wind speed, solar radiation, and precipitation conditions to examine the impact of potential biases or error in the input data. To test the impact of a positive bias in the wind speeds, diurnal warming magnitudes are recomputed with an adjusted wind under near‐neutral conditions. Compared to the original data, diurnal warming can increase by as much as 1.5°C on an hourly scale but generally is <0.06°C. Although precipitation effects on dSSTs are small compared to winds and radiation, the model configuration wrongly causes diurnal warming to increase by precipitation, contrary to the underlying model physics.
Wind‐driven spreading of fresh surface water beneath ice shelves in the Eastern Weddell Sea
Authors: Zhou Q. , Hattermann T. , Nøst O. A. , Biuw M. , Kovacs K. M. , Lydersen C. 
Published: May 2014

AbstractSolar heated, fresh Antarctic Surface Water (ASW) is a permanent feature along the Eastern Weddell Sea (EWS) coast in summer down to a depth of roughly 200 m. Recently, ASW has been observed beneath the Fimbul Ice Shelf, suggesting that it might play an important role in basal melting. We propose that wind‐driven coastal downwelling is the main mechanism that spreads ASW beneath the ice shelf in this sector of Antarctica. We validate this hypothesis with observations, scaling analyses, and numerical modeling, along three principle lines: (i) data analyses of about 1500 salinity profiles collected by instrumented seals indicate that the observed freshening of the coastal water column is likely explained by the on‐shore Ekman transport and subsequent downwelling of ASW; (ii) an analytical model of the coastal momentum balance indicates that wind‐driven downwelling is capable of depressing the buoyant surface water to a depth similar to the ice shelf draft; and (iii) simulations from both idealized and regional eddy‐resolving numerical ice shelf/ocean models support our proposition. Our main conclusion is that wind‐driven spreading of ASW beneath the ice shelf occurs when downwelling exceeds the depth of the ice shelf base. Furthermore, our study adds to the understanding of the oceanic processes at the Antarctic Slope Front in the EWS, with possible implications for other sectors of Antarctica.
Ocean eddy freshwater flux convergence into the North Atlantic subtropics
Authors: Gordon Arnold L. , Giulivi Claudia F. 
Published: May 2014

AbstractFor a quasi steady state condition, the water vapor flux from the ocean to atmosphere typical of the salty subtropics must be compensated by ocean processes that transfer freshwater into the evaporative regime. Observations of the North Atlantic subtropical sea surface salinity maximum region frequently reveal the presence of eddies with distinct salinity/temperature signatures of up to 0.2 psu/1°C, with horizontal scales of up to 200 km. Using the surface layer salinity and meridional velocity from the Simple Ocean Data Assimilation (SODA) reanalysis data, we find that the eddy flux can accomplish 50% to 75% of the required freshwater convergence into the subtropical regime, the rest being delivered by Ekman transport convergence, and therefore represents a significant component of the marine hydrological cycle. Interannual fluctuations of the eddy freshwater flux are reflected in sea surface salinity variability.
Low‐latitude midnight brightness in 630.0 nm limb observations by FORMOSAT‐2/ISUAL
Authors: Rajesh P. K. , Chen C. H. , Lin C. H. , Liu J. Y. , Huba J. D. , Chen A. B. , Hsu R. R. , Chen Y. T. 
Published: May 2014

AbstractThis paper investigates the intense airglow brightness often observed in the 630.0 nm limb images taken using Imager of Sprites and Upper Atmospheric Lightnings (ISUAL), onboard FORMOSAT‐2 satellite, where the tangent plane of the measurement falls in the local midnight sector. Most of the images show only single brightness, but in some cases there could be multiple peaks, which sometimes appears to be centered on geographic equator and in some cases falls on either sides of the magnetic equator. In order to understand such intense emission in the near‐midnight hours, the observations are simulated using SAMI2 (SAMI2 is Another Model of the Ionosphere) model parameters based on the ISUAL viewing geometry. The simulations reproduced the measured airglow intensity pattern quite remarkably and suggested that the meridional neutral wind and the resulting plasma distribution are closely related with the observed brightness. The intensity and locations of the airglow brightness peaks could potentially be utilized to infer the strength of meridional neutral wind.
Changes in mining‐induced seismicity before and after the 2007 Crandall Canyon Mine collapse
Authors: Kubacki Tex , Koper Keith D. , Pankow Kristine L. , McCarter Michael K. 
Published: May 2014

AbstractOn 6 August 2007, the Crandall Canyon Mine in central Utah experienced a major collapse that was recorded as anMw4.1 seismic event. Application of waveform cross‐correlation detection techniques to data recorded at permanent seismic stations located within ~30 km of the mine has resulted in the discovery of 1494 previously unknown microseismic events related to the collapse. These events occurred between 26 July 2007 and 19 August 2007 and were detected with a magnitude threshold of completeness of 0.0, about 1.6 magnitude units smaller than the threshold associated with conventional techniques. Relative locations for the events were determined using a double‐difference approach that incorporated absolute and differential arrival times. Absolute locations were determined using ground‐truth reported in mine logbooks. Lineations apparent in the newly detected events have strikes similar to those of known vertical joints in the mine region, which may have played a role in the collapse. Prior to the collapse, seismicity occurred mostly in close proximity to active mining, though several distinct seismogenic hot spots within the mine were also apparent. In the 48 h before the collapse, changes inbvalue and event locations were observed. The collapse appears to have occurred when the migrating seismicity associated with direct mining activity intersected one of the areas identified as a seismic hot spot. Following the collapse,bvalues decreased and seismicity clustered farther to the east.
Extremely low frequency electromagnetic field measurements at the Hylaty station and methodology of signal analysis
Authors: Kulak Andrzej , Kubisz Jerzy , Klucjasz Slawomir , Michalec Adam , Mlynarczyk Janusz , Nieckarz Zenon , Ostrowski Michal , Zieba Stanislaw 
Published: May 2014

AbstractWe present the Hylaty geophysical station, a high‐sensitivity and low‐noise facility for extremely low frequency (ELF, 0.03–300 Hz) electromagnetic field measurements, which enables a variety of geophysical and climatological research related to atmospheric, ionospheric, magnetospheric, and space weather physics. The first systematic observations of ELF electromagnetic fields at the Jagiellonian University were undertaken in 1994. At the beginning the measurements were carried out sporadically, during expeditions to sparsely populated areas of the Bieszczady Mountains in the southeast of Poland. In 2004, an automatic Hylaty ELF station was built there, in a very low electromagnetic noise environment, which enabled continuous recording of the magnetic field components of the ELF electromagnetic field in the frequency range below 60 Hz. In 2013, after 8 years of successful operation, the station was upgraded by extending its frequency range up to 300 Hz. In this paper we show the station's technical setup, and how it has changed over the years. We discuss the design of ELF equipment, including antennas, receivers, the time control circuit, and power supply, as well as antenna and receiver calibration. We also discuss the methodology we developed for observations of the Schumann resonance and wideband observations of ELF field pulses. We provide examples of various kinds of signals recorded at the station.
Comparative analysis of facial morphology between Okinawa Islanders and mainland Japanese using three‐dimensional images
Authors: Miyazato Eri , Yamaguchi Kyoko , Fukase Hitoshi , Ishida Hajime , Kimura Ryosuke 
Published: May 2014

ABSTRACTObjectivesDifferences in facial height and breadth between Okinawa Islanders and mainland Japanese have been reported in previous craniometric and somatometric studies. This study using three‐dimensional (3D) images aimed to identify more detailed characteristics of facial morphology in each population.MethodsUsing a hand‐held 3D scanner, we obtained 60 facial surface images each from Okinawa Islanders and mainland Japanese. Twenty‐one landmarks were plotted on a computer and 27 measurements of distances and angles between the landmarks were taken. Statistical analyses such as t test, principal component analysis (PCA), regression analysis, and discriminant analysis were performed to identify sex and regional differences, the patterns of facial features, factors explaining the facial patterns, and other features.ResultsOkinawa Islanders showed lower facial and nasal heights than mainland Japanese. Furthermore, we identified larger protrusions of the glabella and nasal root in Okinawa Islanders than in mainland Japanese. In the PCA, we observed components of facial shape patterns. These components mainly represented facial size (PC1), facial depth (PC2), the prominence of the glabella and nasal root (PC3), and facial breadth (PC4). We identified that the population difference is strongly associated with PC3.ConclusionsThis study quantitatively identified differences in the facial morphology between Okinawa Islanders and mainland Japanese using 3D digital images, with special emphases on the differences in the nasal height and the prominence of the glabella and nasal root. Am. J. Hum. Biol. 26:538–548, 2014. © 2014 Wiley Periodicals, Inc.
Removal of Cd2+, Cu2+, Ni2+, and Pb2+ ions from aqueous solutions using tururi fibers as an adsorbent
Authors: Melo Diego Q. , Vidal Carla B. , da Silva André Leandro , Teixeira Raimundo N. P. , Raulino Giselle Santiago Cabral , Medeiros Thiago C. , Fechine Pierre B. A. , Mazzeto Selma Elaine , De Keukeleire Denis , Nascimento Ronaldo F. 
Published: May 2014

ABSTRACTThis work investigates the removal of Cd2+, Cu2+, Ni2+, and Pb2+ ions from aqueous solutions using tururi fibers as an adsorbent under both batchwise and fixed‐bed conditions. It was found that modification of the tururi fibers with sodium hydroxide increased the adsorption efficiencies of all metal ions studied. The fractional factorial design showed that pH, adsorbent mass, agitation rate, and initial metal concentration influenced each metal adsorption differently. The kinetics showed that multi‐element adsorption equilibria were reached after 15 min following pseudo‐second‐order kinetics. The Langmuir, Freundlich, and Redlich–Peterson models were used to evaluate the adsorption capacities by tururi fibers. The Langmuir model was found to be suitable for all metal ions. Breakthrough curves revealed that saturation of the bed was reached in 160.0 mL with Cd2+ and Cu2+, and 52.0 mL with Ni2+ and Pb2+. The Thomas model was applied to the experimental data of breakthrough curves and represented the data well. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40883.
Morphology and chain mobility of reactive blend nanocomposites of PP‐EVA/Clay
Authors: Mata‐Padilla José M. , Medellín‐Rodríguez Francisco J. , Ávila‐Orta Carlos A. , Ramírez‐Vargas Eduardo , Cadenas‐Pliego Gregorio , Valera‐Zaragoza Mario , Vega‐Díaz Sofía M. 
Published: May 2014

ABSTRACTPolypropylene (PP)‐ethylene vinyl acetate (EVA)/clay nanocomposites were prepared via reactive blending using dicumyl peroxide (DCP) as an initiator with the goal of enhancing the interaction between both phases and modified nanoclay. The effect of the reactive blending and clay incorporation strategies (direct and masterbatch) on the blend and nanostructure morphology, and chain mobility of nanocomposites were studied. The chemical analysis showed the chemical bonding of PP‐EVA, which helped to enhance the interaction in the nanocomposites. The nanocomposites obtained from the direct clay strategy presented a co‐continuous morphology of bordering intercalated and agglomerated nanoclay sheets, while the nanocomposites obtained from the masterbatch strategy showed that blend morphology change from droplet to co‐continuous with the increase of EVA concentration, with intercalated/exfoliated nanoclay sheets located in the EVA domains and at the interface. The dynamic mechanical and creep‐recovery results showed different behavior for the both strategies in terms of chain mobility and relaxation. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40897.
The effect of graft copolymers of maleic anhydride and epoxy resin on the mechanical properties and morphology of PP/ABS blends
Authors: Luo Zhu , Lu Qiuyi , Ma Fenghe , Jiang Yi 
Published: May 2014

ABSTRACTIn this work, maleic anhydride‐grafted polypropylene (PP‐g‐MAH) and maleic anhydride‐grafted poly(acrylonitrile‐butadiene‐styrene) (ABS‐g‐MAH) at 2 : 1 mass ratio were added as a compatibilizer in the PP/ABS blends. The compatibilizing effect was evaluated by adding the graft copolymers together with epoxy resin/imidazole curing agent (E51/2E4MZ). The reaction in reactive extrusion, morphological structure, and properties of PP and ABS blends were investigated by using infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X‐ray spectrum, transmission electron microscope (TEM), dynamic thermomechanical analysis (DMA), differential scanning calorimetry (DSC), and mechanical properties tests. The results showed that the compatibilizing effect was greatly improved because of the addition of the graft copolymers together with epoxy resin/imidazole curing agent (E51/2E4MZ) because the link structure of PP‐g‐MAH and ABS‐g‐MAH was formed by the reaction of anhydride group with epoxy group catalyzed by the imidazole. The size of the dispersed phase decreased dramatically, the interfacial adhesion between ABS particles and PP matrix was improved, and the tensile strength and flexural modulus of the PP/ABS blends increased further. The optimizing properties were obtained at 3 phr E51/2E4MZ. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40898.
Synthesis and characterization of polyhydroxylated polybutadiene binding 2,2′‐thiobis(4‐methyl‐6‐tert‐butylphenol) with isophorone diisocyanate
Authors: Wu Wenjian , Zeng Xingrong , Li Hongqiang , Lai Xuejun , Yan Zengyang 
Published: May 2014

ABSTRACTA macromolecular hindered phenol antioxidant, polyhydroxylated polybutadiene containing thioether binding 2,2′‐thiobis(4‐methyl‐6‐tert‐butylphenol) (PHPBT‐b‐TPH), was synthesized via a two‐step nucleophilic addition reaction using isophorone diisocyanate (IPDI) as linkage. First, the OH groups of PHPBT reacted with secondary NCO groups of IPDI to form the adduct PHPBT‐NCO, then the PHPBT‐b‐TPH was obtained by one phenolic OH of 2,2′‐thiobis(4‐methyl‐6‐tert‐butylphenol) (TPH) reacting with the PHPBT‐NCO. The PHPBT‐b‐TPH was characterized by Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance (1H‐NMR), 13C‐NMR, and thermogravimetric analysis, and its antioxidant activity in natural rubber was studied by an accelerated aging test. Influences of reaction conditions on the two nucleophilic reactions between OH group and NCO group were investigated. In addition, catalytic mechanism for the reaction between PHPBT‐NCO and TPH was discussed. The results showed that the adduct PHPBT‐NCO could be obtained by using dibutyltin dilaurate (DBTDL) as catalyst, and the suitable temperature and DBTDL amount were 35°C and 3 wt %, respectively. However, triethylamine (TEA) was more efficient than DBTDL to catalyze the reaction between PHPBT‐NCO and TPH because of steric hindrance effect. In addition, it was found that the thermal stability and antioxidant activity of PHPBT‐b‐TPH were higher than those of the low molecular weight antioxidant TPH. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40942.
Optimization of Coordinate Transformation Matrix for H∞ Static‐Output‐Feedback Control of Linear Discrete‐Time Systems
Authors: Feng Zhi‐Yong , Xu Li , She Jinhua , Guo Xue‐Xun 
Published: May 2014

AbstractThis paper presents a new iterative algorithm as an upgrade to sufficient LMI conditions for the H∞ static‐output‐feedback (SOF) control of discrete‐time systems. Based on an analysis of the structures of the coordinate transformation matrix and the Lyapunov matrix, the open question of how to fix the Lyapunov matrix structure raised by G. I. Bara and M. Boutayeb is replaced with the question of how to choose the coordinate transformation matrix. Then, an iterative algorithm for selecting the optimum coordinate transformation matrix that produces a locally optimal solution is presented. Finally, numerical examples demonstrate the effectiveness and advantages of this method.
A Port‐Hamiltonian Approach to Visual Servo Control of a Pick and Place System
Authors: Dirksz Daniel A. , Scherpen Jacquelien M.A. , Steinbuch Maarten 
Published: May 2014

AbstractIn this paper, we take a port‐Hamiltonian approach to address the problem of image‐based visual servo control of a pick and place system. Through a coordinate transformation and a passive interconnection between mechanical system and camera dynamics we realize a closed‐loop system that is port‐Hamiltonian. The resulting control strategy depends only on the camera states and it can be proven that the closed‐loop system is also asymptotically stable. Furthermore, a region of attraction is defined for which asymptotic stability holds.
1,4‐Addition of TMSCCl3 to Nitroalkenes: Efficient Reaction Conditions and Mechanistic Understanding
Authors: Wu Na , Wahl Benoit , Woodward Simon , Lewis William 
Published: May 2014

AbstractImproved synthetic conditions allow preparation of TMSCCl3 in good yield (70 %) and excellent purity. Compounds of the type NBu4X [X=Ph3SiF2 (TBAT), F (tetrabutylammonium fluoride, TBAF), OAc, Cl and Br] act as catalytic promoters for 1,4‐additions to a range of cyclic and acyclic nitroalkenes, in THF at 0–25 °C, typically in moderate to excellent yields (37–95 %). TBAT is the most effective promoter and bromide the least effective. Multinuclear NMR studies (1H, 19F, 13C and 29Si) under anaerobic conditions indicate that addition of TMSCCl3 to TBAT (both 0.13 M) at −20 °C, in the absence of nitroalkene, leads immediately to mixtures of Me3SiF, Ph3SiF and NBu4CCl3. The latter is stable to at least 0 °C and does not add nitroalkene from −20 to 0 °C, even after extended periods. Nitroalkene, in the presence of TMSCCl3 (both 0.13 M at −20 °C), when treated with TBAT, leads to immediate formation of the 1,4‐addition product, suggesting the reaction proceeds via a transient [Me3Si(alkene)CCl3] species, in which (alkene) indicates an Si⋅⋅⋅O coordinated nitroalkene. The anaerobic catalytic chain is propagated through the kinetic nitronate anion resulting from 1,4 CCl3− addition to the nitroalkene. This is demonstrated by the fact that isolated NBu4[CH2NO2] is an efficient promoter. Use of H2CCH(CH2)2CHCHNO2 in air affords radical‐derived bicyclic products arising from aerobic oxidation.
New Developments of a Multifrequency Virtual Spectrometer: Stereo‐Electronic, Dynamical, and Environmental Effects on Chiroptical Spectra
Authors: Barone Vincenzo , Baiardi Alberto , Bloino Julien 
Published: May 2014

ABSTRACTComputational spectroscopy has recently evolved from a field reserved for specialists toward a general tool allowing interpretations and analyses of experimental results. However, the current practice of providing tables of transitions for rigid geometries, possibly tuned by phenomenological broadening, is by far too naive. In order to improve this situation in the last few years we have been developing a general, robust, and user‐friendly virtual spectrometer (VS) able to complement experimental studies for complex systems in condensed phases. The VS is based on flexible graphical pre‐ and postprocessing tools interfaced with general number‐crunching software. This last tool is rooted in several electronic structure methodologies (DFT, TD‐DFT, post‐Hartree‐Fock), powerful discrete/continuum models for describing environmental effects, and general vibrational and vibronic models. These last topics are the main focus of this work, which sketches our latest developments related to effective inclusion of anharmonic contributions, together with time‐independent and/or time‐dependent descriptions of vibronic transitions including Franck‐Condon, Herzberg‐Teller, and Duschinsky effects. Some test cases are described in some detail with the aim of showing the role of different effects in ruling vibrational (VCD) and electronic (ECD, CPL) chiral spectroscopies. Chirality 26:588–600, 2014. © 2014 Wiley Periodicals, Inc.
Circular Dichroism Sensing of Chiral Compounds Using an Achiral Metal Complex as Probe
Authors: Irfanoglu Burcin , Wolf Christian 
Published: May 2014

ABSTRACTCoordination of a chiral substrate to (meso‐salen)cobalt(II) nitrate and subsequent oxidation generates a Co(III) complex exhibiting a strong chiroptical readout that is attributed to spontaneous substrate‐to‐ligand chirality imprinting. The characteristic circular dichroism (CD) response of the (salen)cobalt complex can be used for enantiomeric analysis of a variety of chiral substrates based on a simple CD measurement at low concentration and without additional purification steps. This chirality sensing approach has potential for high‐throughput enantiomeric excess (ee) screening applications and minimizes solvent waste production. Chirality 26:379–384, 2014. © 2014 Wiley Periodicals, Inc.
Quantum chemical meta‐workflows in MoSGrid
Authors: Herres‐Pawlis Sonja , Hoffmann Alexander , Balaskó Ákos , Kacsuk Peter , Birkenheuer Georg , Brinkmann André , de la Garza Luis , Krüger Jens , Gesing Sandra , Grunzke Richard , Terstyansky Gabor , Weingarten Noam 
Published: May 2014

SummaryQuantum chemical workflows can be built up within the science gateway Molecular Simulation Grid. Complex workflows required by the end users are dissected into smaller workflows that can be combined freely to larger meta‐workflows. General quantum chemical workflows are described here as well as the real use case of a spectroscopic analysis resulting in an end‐user desired meta‐workflow. All workflow features are implemented via Web Services Parallel Grid Runtime and Developer Environment and submitted to UNICORE. The workflows are stored in the Molecular Simulation Grid repository and ported to the SHIWA repository. Copyright © 2014 John Wiley & Sons, Ltd.