bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Impact of Frictional Healing on Stick‐Slip Recurrence Interval and Stress Drop: Implications for Earthquake Scaling
Authors: Im Kyungjae , Elsworth Derek , Marone Chris , Leeman John 
Published: November 2017

AbstractInterseismic frictional healing is an essential process in the seismic cycle. Observations of both natural and laboratory earthquakes demonstrate that the magnitude of stress drop scales with the logarithm of recurrence time, which is a cornerstone of the rate and state friction (RSF) laws. However, the origin of this log linear behavior and short time “cutoff” for small recurrence intervals remains poorly understood. Here we use RSF laws to demonstrate that the back‐projected time of null‐healing intrinsically scales with the initial frictional state θi. We explore this behavior and its implications for (1) the short‐term cutoff time of frictional healing and (2) the connection between healing rates derived from stick‐slip sliding versus slide‐hold‐slide tests. We use a novel, continuous solution of RSF for a one‐dimensional spring‐slider system with inertia. The numerical solution continuously traces frictional state evolution (and healing) and shows that stick‐slip cutoff time also scales with frictional state at the conclusion of the dynamic slip process θi (=Dc/Vpeak). This numerical investigation on the origins of stick‐slip response is verified by comparing laboratory data for a range of peak slip velocities. Slower slip motions yield lesser magnitude of friction drop at a given time due to higher frictional state at the end of each slip event. Our results provide insight on the origin of log linear stick‐slip evolution and suggest an approach to estimating the critical slip distance on faults that exhibit gradual accelerations, such as for slow earthquakes.
Wintertime Phytoplankton Blooms in the Western Equatorial Indian Ocean Associated With the Madden‐Julian Oscillation
Authors: Liao Xiaomei , Du Yan , Zhan Haigang , Wang Tianyu , Feng Ming 
Published: November 2017

AbstractThis study investigated boreal wintertime phytoplankton blooms in the western equatorial Indian Ocean (WEIO) and the underlying physical mechanisms. The Sea viewing Wide field of View sensor (SeaWiFS) chlorophyll‐a (Chla) concentrations show that phytoplankton blooms occur in the WEIO during December–March. The development of these blooms is not only a seasonal process but also consists of 2–3 intraseasonal events induced by the Madden‐Julian Oscillation (MJO). During a typical intraseasonal event, enhanced cross‐equatorial wind induces strong upwelling and ocean mixing, thus increasing the supply of nutrients to the surface in equatorial regions. Argo profiles clearly show various responses to the intraseasonal wind bursts, including shoaling of the thermocline and deepening of the mixed layer. Further analysis reveals that the former is the dominant mechanism for the blooms along the equator, while the latter controls the high Chla concentrations off the coast of Somalia. Surface ocean circulations not only account for the blooms south of the equator but also modulate the thermocline depth in the WEIO. The shallower thermocline during the early period of the northeast monsoon season provides favorable conditions for a stronger Chla response to intraseasonal forcing.
Effect of the Initial Vortex Size on Intensity Change in the WRF‐ROMS Coupled Model
Authors: Zhao Xiaohui , Chan Johnny C. L. 
Published: November 2017

AbstractNumerous studies have demonstrated that the tropical cyclone (TC) induced sea surface temperature (SST) cooling strongly depends on the preexisting oceanic condition and TC characteristics. However, very few focused on the correlation of SST cooling and the subsequent intensity with TC size. Therefore, a series of idealized numerical experiments are conducted using the Weather Research Forecasting (WRF) model coupled with the Regional Ocean Model System (ROMS) model to understand how the vortex size is related to SST cooling and subsequent intensity changes of a stationary TC‐like vortex. In the uncoupled experiments, the radius of maximum wind (RMW) and size (radius of gale‐force wind (R17)) both depend on the initial size within the 72 h simulation. The initially small vortex is smaller than the medium and large vortices throughout its life cycle and is the weakest. In other words, thermodynamic processes do not contribute as much to the R17 change as the dynamic processes proposed (e.g., angular momentum transport) in previous studies. In the coupled experiments, the area‐averaged SST cooling induced by medium and large TCs within the inner‐core region is comparable due to the similar surface winds and thus mixing in the ocean. Although a stronger SST cooling averaged within a larger region outside the inner‐core is induced by the larger TC, the intensity of the larger TC is more intense. This is because that the enthalpy flux in the inner‐core region is higher in the larger TC than that in the medium and small TCs.
Mathematical Modelling of Arctic Polygonal Tundra with Ecosys: 1. Microtopography Determines How Active Layer Depths Respond to Changes in Temperature and Precipitation
Authors: Grant R. F. , Mekonnen Z. A. , Riley W. J. , Wainwright H. M. , Graham D. , Torn M. S. 
Published: November 2017

AbstractMicrotopographic variation that develops among features (troughs, rims, and centers) within polygonal landforms of coastal arctic tundra strongly affects movement of surface water and snow and thereby affects soil water contents (θ) and active layer depth (ALD). Spatial variation in ALD among these features may exceed interannual variation in ALD caused by changes in climate and so needs to be represented in projections of changes in arctic ALD. In this study, increases in near‐surface θ with decreasing surface elevation among polygon features at the Barrow Experimental Observatory (BEO) were modeled from topographic effects on redistribution of surface water and snow and from lateral water exchange with a subsurface water table during a model run from 1981 to 2015. These increases in θ caused increases in thermal conductivity that in turn caused increases in soil heat fluxes and hence in ALD of up to 15 cm with lower versus higher surface elevation which were consistent with increases measured at BEO. The modeled effects of θ caused interannual variation in maximum ALD that compared well with measurements from 1985 to 2015 at the Barrow Circumpolar Active Layer Monitoring (CALM) site (R2 = 0.61, RMSE = 0.03 m). For higher polygon features, interannual variation in ALD was more closely associated with annual precipitation than mean annual temperature, indicating that soil wetting from increases in precipitation may hasten permafrost degradation beyond that caused by soil warming from increases in air temperature. This degradation may be more rapid if increases in precipitation cause sustained wetting in higher features.
Estimation of Woody and Herbaceous Leaf Area Index in Sub‐Saharan Africa Using MODIS Data
Authors: Kahiu M. N. , Hanan N. P. 
Published: November 2017

AbstractSavannas are widespread global biomes covering ~20% of terrestrial ecosystems on all continents except Antarctica. These ecosystems play a critical role in regulating terrestrial carbon cycle, ecosystem productivity, and the hydrological cycle and contribute to human livelihoods and biodiversity conservation. Despite the importance of savannas in ecosystem processes and human well‐being, the presence of mixed woody and herbaceous components at scales much finer than most medium‐ and coarse‐resolution satellite imagery poses significant challenges to their effective representation in remote sensing and modeling of vegetation dynamics. Although previous studies have attempted to separate woody and herbaceous components, the focus on greenness indices and fractional cover provides little insight into spatiotemporal variability in woody and herbaceous vegetation structure, in particular, leaf area index (LAI). This paper presents a method to partition 1 km spatial resolution Moderate Resolution Imaging Spectroradiometer (MODIS) aggregate green leaf area index (LAIA) from 2003 to 2015, into separate woody (LAIW) and herbaceous (LAIH) constituents in both drought seasonal savannas and moist tropical forests of Sub‐Saharan Africa (SSA). In our analysis, we use an allometric relationship describing the variation in peak within‐canopy woody LAI of dominant tree species (LAIWpinc) across gradients in mean annual precipitation, coupled with independent estimates of woody canopy cover (τw), to constrain seasonally changing LAIW. We present the LAI partitioning approach and highlight the broad spatial and temporal patterns of woody and herbaceous LAI across SSA. The long‐term average 8 day phenologies of woody and herbaceous LAI (averaged across 2003–2015) are available for evaluation, research, and application purposes.
Tailoring Hybrid Layered Double Hydroxides for the Development of Innovative Applications
Authors: Taviot‐Guého Christine , Prévot Vanessa , Forano Claude , Renaudin Guillaume , Mousty Christine , Leroux Fabrice 
Published: November 2017

AbstractHybrid materials based on layered double hydroxides (LDHs) exhibit great potential in diverse fields such as health care, polymer composites, environment, catalysis, and energy generation. Indeed, the compositional flexibility and the scalability of LDH structures, their low cost, and their ease of synthesis have made hybrid LDHs extremely attractive for constructing smart and high‐performance multifunctional materials. This review provides a comprehensive and critical overview of the current research on multifunctional hybrid LDHs. Organic–inorganic hybrid LDHs, intercalated and surface‐immobilized structures, are both specifically addressed. The new trends and strategies for hybrid LDH synthesis are first described, and then the potential of the latest hybrid LDHs, polymer LDH nanocomposites, and LDH bio‐nanocomposites are presented. Significant achievements published from ≈2010, including authors' results, which employ hybrid LDH assemblies in materials science, medicine, polymer nanocomposites, cement chemistry, and environmental technologies, are specifically addressed. It is concluded with remarks on present challenges and future prospects.
High‐Resolution Patterning and Transferring of Graphene‐Based Nanomaterials onto Tape toward Roll‐to‐Roll Production of Tape‐Based Wearable Sensors
Authors: Oren Seval , Ceylan Halil , Schnable Patrick S. , Dong Liang 
Published: November 2017

AbstractThis paper reports on a simple and versatile method for patterning and transferring graphene‐based nanomaterials onto various types of tape to realize flexible microscale sensors. The method involves drop‐casting a graphene film on a prepatterned polydimethylsiloxane (PDMS) surface containing negative features by graphene suspensions, applying Scotch tape to remove the excess graphene from the nonpatterned areas of the PDMS surface, and then transferring the patterned graphene from the inside of the negative features at the PDMS surface onto a target tape. The feature size of transferred graphene patterns on the final tape is as small as a few micrometers. This method is easy to implement, but does not require the use of expensive equipment, except for needing a PDMS substrate containing negative features. This method has a high versatility in producing micropatterns of graphene‐based nanomaterials on different types of adhesive tape. For the purpose of application demonstration, flexible mechanical sensors and sensor arrays, smart gloves, and plant leaf sensors on tapes to realize real‐time monitoring of important signals indicating human motion and plant water transport behavior have been developed. This technology will open a new route for low‐cost, scalable, and roll‐to‐roll production of graphene‐based sensors on tape.
Das schwach koordinierende Tris(trichlorsilyl)silyl‐Anion
Authors: Olaru Marian , Hesse Maxie F. , Rychagova Elena , Ketkov Sergey , Mebs Stefan , Beckmann Jens 
Published: November 2017

AbstractIn Anlehnung an die Vorschrift von Roesky und Stalke et al. (Angew. Chem. 2009, 121, 5793–5796) zur Herstellung des basenstabilisierten Dichlorsilylen‐Komplexes NHCDipp⋅SiCl2 wurden neben dem beschriebenen Nebenprodukt [NHCDipp‐H+⋅⋅⋅Cl‐] wenige Kristalle des Salzes [NHCDipp‐H⋅⋅⋅Cl⋅⋅⋅H‐NHCDipp]Si(SiCl3)3 isoliert und kristallographisch charakterisiert (NHCDipp=N,N‐Bis(2,6‐diisopropylphenyl)imidazo‐2‐yliden). Sie enthalten das schwach koordinierende Si(SiCl3)3−‐Anion, das systematisch in hohen Ausbeuten durch die Deprotonierung der konjugierten Brønsted‐Säure HSi(SiCl3)3 mit NHCDipp oder 1,2,2,6,6‐Pentamethylpiperidin erhalten wurde. Die durch DFT‐Rechnungen abgeschätzte Acidität von HSi(SiCl3)3 ist bedeutend höher als die anderer H‐Silane. DFT‐Rechnungen zur elektronischen Struktur von Si(SiCl3)3−, einschließlich des elektrostatischen Potentials und der Elektronenlokalisierbarkeit, bestätigen die geringe Basizität und Nukleophilie im Vergleich zu anderen Silylanionen.
Impacts of projected urban expansion and global warming on cooling energy demand over a semiarid region
Authors: Tewari Mukul , Salamanca Francisco , Martilli Alberto , Treinish Lloyd , Mahalov Alex 
Published: November 2017

AbstractLarge impacts of global warming and urbanization on near‐surface air temperature increase and cooling energy demand are expected for the American Southwest region. The relative importance of these two features and their interactions are studied by means of a mesoscale model with a multilayer building energy model that allows accounting for the feedback between cooling energy consumption and air temperature for a typical summer period in Arizona. This approach allows to separate the impact of global warming from the one due to urbanization, on energy demand and air temperature. Under the highest greenhouse gas emissions scenario (RCP8.5), adverse effects on mean air temperature of global warming overwhelm those from the urbanization of new areas. In particular, the mean temperature increase for a summer period due to global warming and urban expansion in the Phoenix metropolitan area is 3.6 °C and in the Tucson metropolitan area, it is 3.1 °C. These result in an increase in the spatial density of the cooling energy demand (MW km−2) by 36.2 and 42.6% in the respective regions compared to present consumption. The citywide cooling energy demand (MW) on the other hand, is expected to increase up to a factor two (Phoenix) and three (Tucson), with ∼75% of this increase due to urban expansion, and ∼25% due to global warming.
Quantification of the responses of equatorial Pacific surface wind to uncertain cloud‐related parameters in GAMIL2
Authors: Xie Feng , Xue Wei , Li Lijuan , Zhang Tao , Wang Bin , Xu Shiming 
Published: November 2017

AbstractThe response of surface winds over the equatorial Pacific to cloud‐related parameters is quantified by using a uniform sampling method and conducting a large number of perturbed parameter simulations. The results show that the surface winds are highly sensitive to, and even linearly dependent on some parameters that include the precipitation efficiency for deep convection (C0_deep), the time scale for the consumption rate of shallow CAPE (CMFTAU), and the threshold value for RH for deep convection (RHCRIT), indicating the potential to improve surface wind simulations by tuning these parameters. Parameter changes indirectly affect surface winds through changes in vertical velocity or deduced circulation linked to diabatic heating (DH) above the surface. The relative contribution of static stability changes induced by perturbed parameter to balancing DH and affecting vertical velocity exceeds 10% in most of the troposphere.
Early executive dysfunction in ASD: Simple versus complex skills
Authors: Garon Nancy , Smith Isabel M. , Bryson Susan E. 
Published: November 2017

Despite the strong evidence of executive function (EF) impairment in Autism Spectrum Disorder (ASD), findings in the preschool period have been inconsistent. Whereas some research has supported an early deficit, many studies have not found early differences in EF. The present study assessed simple and complex components of three EF abilities: working memory, inhibition, and shifting, using a novel battery, the Preschool EF Battery (PEFB; Garon, Smith & Bryson, Child Neuropsychology, 20, 713–736, 2014). Previous research has indicated that the PEFB is sensitive to age differences in typically developing (TD) children aged 18–60 months. Current participants were 34 preschoolers (M = 54.79 months) diagnosed with ASD and 255 TD preschoolers (M = 42.98 months). Results indicated significant differences between the two groups in the three EF abilities, but specific findings were moderated by mental and chronological age. The findings highlight the importance of testing simpler EF skills in very young children with ASD. Autism Res 2018, 11: 318–330. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.Lay SummaryGiven that executive functions (EF) have been found to predict various outcomes such as academic ability and occupational success, sensitive early assessment is important. The current study suggests the presence of early EF deficits in preschool children with autism spectrum disorder. The study highlights the importance of considering how EF develops during early life in typically developing children in order to design sensitive EF measures.
Frailty in nonagenarians: A bridge too far?
Authors: Morad Mohammad , Gray William A. 
Published: November 2017

Key Points

There is no clear consensus about the definition of frailty and how to accurately measure it.
There is accumulating evidence that frail old patients have worse outcomes after TAVR compared to non‐frail patients.
Further randomized research is needed to confirm those concerns and to standardize the role of frailty assessment in patient selection for TAVR.
Exceptionally Efficient and Recyclable Heterogeneous Metal–Organic Framework Catalyst for Glucose Isomerization in Water
Authors: Oozeerally Ryan , Burnett David L. , Chamberlain Thomas W. , Walton Richard I. , Degirmenci Volkan 
Published: November 2017

AbstractHeterogeneous catalysts are desired for the conversion of glucose, the most abundant sugar in renewable biomass, but presently their synthesis requires highly toxic chemicals with long synthesis times. We report the conversion of glucose into fructose and 5‐hydroxymethylfurfural on a heterogeneous catalyst that is stable and selective and operates in the most environmentally benign solvent, water. We used a bifunctional solid with Lewis and Brønsted acid sites by partially replacing the organic linker of the zirconium organic framework UiO‐66 with 2‐monosulfo‐benzene‐1,4‐dicarboxylate. This catalyst showed high product selectivity (90 %) to 5‐hydroxymethylfurfural and fructose at 140 °C in water after a reaction time of 3 h. It was recyclable and showed only a minor loss in activity after the third recycle, offering a realistic solution for the bottleneck glucose isomerization reaction for scale‐up and industrial application of biomass utilization.
Photophysical and Photoacoustic Properties of Quadrupolar Borondifluoride Curcuminoid Dyes
Authors: Bellinger Stephanie , Hatamimoslehabadi Maryam , Bag Seema , Mithila Farha , La Jeffrey , Frenette Mathieu , Laoui Samir , Szalda David J. , Yelleswarapu Chandra , Rochford Jonathan 
Published: November 2017

AbstractThe synthesis and characterization of a series of donor‐π‐acceptor‐π‐donor (D‐A‐D) curcuminoid molecules is presented herein that incorporates π‐extended aryl and electron‐donating amino terminal functionalization. Computational evaluation shows these molecules possess quadrupolar character with the lowest energy transitions displaying high molar extinction coefficients with broad tunability through manipulation of terminal donating groups. Consistent with their quadrupolar nature, these molecules show varying degrees of solvatochromic behavior in both their absorption and emission spectra, which has been analyzed by Lippert–Mataga and Kamlet–Taft analysis. Photophysical and photoacoustic (PA) properties of these molecules have been investigated by the optical photoacoustic z‐scan (OPAZ) method. Selected curcuminoid molecules display nonlinear behavior at a high laser fluence through excited state absorption that translates to the production of an enhanced photoacoustic emission. A relative comparison of “molar PA emission” is also presented with the crystal violet linear optical absorbing/linear PA emitting system being utilized as a standard reference material for OPAZ experiments. Furthermore, PA tomography experiments are presented to illustrate the enhanced PA contrast obtainable via an excited state absorption.
Hybrid iterative learning fault‐tolerant guaranteed cost control design for multi‐phase batch processes
Authors: Wang Limin , Shen Yiteng , Li Bingyun , Yu Jingxian , Zhang Ridong , Gao Furong 
Published: November 2017

AbstractA robust design of a hybrid iterative learning fault‐tolerant guaranteed cost control scheme is proposed for a class of multi‐phase batch processes under faults and disturbances. Firstly, based on an equivalent two‐dimensional Fornasini‐Marchesini (2D‐FM) switched system with actuator faults varying within an allowable range, a 2D robustly hybrid controller that includes a robust hybrid extended feedback control to ensure performance over time and a hybrid iterative learning control to improve the tracking performance from cycle to cycle is formulated to guarantee the closed‐loop convergence and the H∞ performance level with a cost function bearing the upper bounds for all admissible uncertainty and actuator failures. Secondly, 2D system theory and the average dwell time strategy are adopted to derive conditions for guaranteeing exponential stability of the corresponding system in terms of linear matrix inequalities (LMIs), where the suboptimal hybrid guaranteed cost controller, which minimizes the quadratic performance index and rejects external disturbances, is designed using a convex optimization under LMI constraints. Finally, the proposed method is further verified by simulation on an injection molding process in comparison with traditional methods.
Effect of Tetrahydrofuran on the Solubilization and Depolymerization of Cellulose in a Biphasic System
Authors: Jiang Zhicheng , Zhao Pingping , Li Jianmei , Liu Xudong , Hu Changwei 
Published: November 2017

AbstractThe dissolution of cellulose from biomass is a crucial but complicated issue for maximizing the utilization of biomass resources to produce valuable chemicals, because of the extreme insolubility of cellulose. A biphasic NaCl–H2O–tetrahydrofuran (THF) system was studied, in which most of the pure microcrystalline cellulose (M‐cellulose, 96.6 % conversion at 220 °C) and that contained in actual biomass were converted. Nearly half of the O6−H⋅⋅⋅O3 intermolecular hydrogen bonds could be broken by THF in the H2O–THF co‐solvent system, whereas the cleavage of O2−H⋅⋅⋅O6 intramolecular hydrogen bonds by H2O was significantly inhibited. In the NaCl–H2O–THF system, THF could significantly promote the effects of both H2O and NaCl on the disruption of O2−H⋅⋅⋅O6 and O3−H⋅⋅⋅O5 intramolecular hydrogen bonds, respectively. In addition, THF could protect and transfer the cellulose‐derived products to the organic phase by forming hydrogen bonds between the oxygen atom in THF and the hydrogen atom of C4−OH in the glucose or aldehyde group in 5‐hydroxymethylfurfural (HMF), which can lead more NaCl to combine with the ‐OH of M‐cellulose and further disrupt hydrogen bonding in M‐cellulose, thereby improving the yield of small molecular weight products (especially HMF) and further promoting the dissolution of cellulose. As a cheap and reusable system, NaCl–H2O–THF system may be a promising approach for the dissolution and further conversion of cellulose in lignocellulosic biomass without any enzymes, ionic liquids, or conventional catalysts.