bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydromechanical Earthquake Nucleation Model Forecasts Onset, Peak, and Falling Rates of Induced Seismicity in Oklahoma and Kansas
Authors: Norbeck J. H. , Rubinstein J. L. 
Published: March 2018

AbstractThe earthquake activity in Oklahoma and Kansas that began in 2008 reflects the most widespread instance of induced seismicity observed to date. We develop a reservoir model to calculate the hydrologic conditions associated with the activity of 902 saltwater disposal wells injecting into the Arbuckle aquifer. Estimates of basement fault stressing conditions inform a rate‐and‐state friction earthquake nucleation model to forecast the seismic response to injection. Our model replicates many salient features of the induced earthquake sequence, including the onset of seismicity, the timing of the peak seismicity rate, and the reduction in seismicity following decreased disposal activity. We present evidence for variable time lags between changes in injection and seismicity rates, consistent with the prediction from rate‐and‐state theory that seismicity rate transients occur over timescales inversely proportional to stressing rate. Given the efficacy of the hydromechanical model, as confirmed through a likelihood statistical test, the results of this study support broader integration of earthquake physics within seismic hazard analysis.
Medium‐Scale Traveling Ionospheric Disturbances Observed by Detrended Total Electron Content Maps Over Brazil
Authors: Figueiredo C. A. O. B. , Takahashi H. , Wrasse C. M. , Otsuka Y. , Shiokawa K. , Barros D. 
Published: March 2018

AbstractA ground‐based network of Global Navigation Satellite Systems receivers has been used to monitor medium‐scale traveling ionospheric disturbances (MSTIDs). MSTIDs were studied using total electron content perturbation maps and keograms over south‐southeast of Brazil during the period from December 2012 to February 2016. In total, 826 MSTIDs were observed mainly in daytime, thus presenting median values of horizontal wavelength, period, and horizontal phase velocity of 452 ± 107 km, 24 ± 4 min. and 323 ± 81 m/s, respectively. The direction of propagation varies on the season: during the winter (June–August), the waves preferentially propagated to north‐northeast, while in the other seasons the waves propagated to other directions. The anisotropy observed in the MSTID propagation direction could be associated with the region of the gravity wave generation that takes place in the troposphere. We also found that the MSTIDs were observed most frequently during the daytime, between 11 and 15 local time in winter and near to dusk solar terminator (17–19 local time) in the other seasons. Furthermore, the occurrence of MSTIDs was higher in winter. We suggest that atmospheric gravity waves in the thermosphere, mesosphere, and troposphere could play an important role in generating the MSTIDs and the propagation direction may depend on location of the wave sources.
Polar Cap Energy Deposition Events During the 5–6 August 2011 Magnetic Storm
Authors: Horvath Ildiko , Lovell Brian C. 
Published: March 2018

AbstractWe study the 5–6 August 2011 storm for its energy deposition events occurring deep in the polar cap region, where the consequential localized intensifications of earthward directed Poynting flux led to the development of their related localized neutral density increases. For unraveling the underlying physical processes, we investigate the relations among Poynting flux intensifications, flow channels (FCs), and localized neutral density enhancements plus the nature of the underlying reconnection events. Observational results demonstrate Poynting flux increase deep in the polar cap in a FC‐2 type FC during magnetopause reconnections and in a FC‐4 type FC during lobe reconnections. During the latter stages of these different types of reconnection events, energy/momentum transfer occurred along old‐open field lines and commonly led to the development of localized neutral density increases during their respective upwelling events fueled by field‐aligned currents and above/within these polar FCs. The prevailing BY domination and the pulsed nature of this storm created favorable conditions for the development of these FC‐2 and FC‐4 types in the sunlit northern summer hemisphere and caused the observed Poynting flux intensifications deep in the polar cap. The solar wind source of these reconnections taking place along old‐open field lines was situated in the high‐latitude boundary layer. Thus, the high‐latitude boundary layer dynamo provided a vigorous source of energy/momentum transfer during the latter‐stage reconnections unfolding along old‐open field lines.
Seismicity Induced by Wastewater Injection in Washington County, Ohio: Influence of Preexisting Structure, Regional Stress Regime, and Well Operations
Authors: Currie Brian S. , Free James C. , Brudzinski Michael R. , Leveridge Max , Skoumal Robert J. 
Published: March 2018

AbstractRecent seismicity in Washington County, Ohio, has been suggested to be induced by wastewater disposal operations despite injection ~2 km above the Precambrian basement. We investigated the relationships between disposal well locations and operational histories, spatiotemporal patterns of seismicity enhanced by waveform correlation, and mapped subsurface structures. We also analyzed proxies for in situ stress conditions to evaluate existing principal stress orientations and magnitudes. Double‐difference relocations of small (ML ≤ 2.1) seismicity revealed linear clusters defining a NE‐SW orientation that parallels the trend of small‐amplitude folds in Upper Paleozoic rocks within 1–2 km of the injection well. Hypocenter depths of ~3.1 to 4.3 km indicate seismicity occurred along faults below the Silurian injection interval in lower Paleozoic strata and Precambrian crystalline basement. Similar folds/faults imaged in nearby seismic reflection lines were associated with basement‐involved fault systems that cut the injection interval targeted by the injection well, providing permeability pathways for fluid pressure increases that initiated slip. Interpreted faults were also optimally oriented in the regional stress field for reactivation due to injection‐related decreases in effective stress. Well completion records suggest that during the recorded seismicity, the Long Run‐1 well was injecting disposal fluids close to or above the fracture pressure of the targeted Silurian injection interval. A comparison of observed seismicity rates and monthly injection records from the disposal well also indicate a close correspondence between earthquake frequency and injection rate. Taken together, these results provide a physical framework for understanding why wastewater disposal operations induced the Washington County seismic sequence.
Aerosol and Urban Land Use Effect on Rainfall Around Cities in Indo‐Gangetic Basin From Observations and Cloud Resolving Model Simulations
Authors: Sarangi Chandan , Tripathi S. N. , Qian Yun , Kumar Shailendra , Ruby Leung L. 
Published: March 2018

AbstractCoupling of urban land use land cover (LULC) and aerosol loading on rainfall around cities in the Gangetic Basin (GB) is examined here. Long‐term observations illustrate more rainfall at urban core and climatological downwind regions compared to the upwind regions of Kanpur, a metropolitan area located in central GB. In addition, analysis of a 15 day cloud resolving simulation using the Weather Research and Forecasting model also illustrated similar rainfall pattern around other major cities in the GB. Interestingly, the enhancement of downwind rainfall was greater than that over urban regions, and it was positively associated with both the urban area of the city and ambient aerosol loading during the propagating storm. Further, to gain a process‐level understanding, a typical storm that propagated northwestward across Kanpur was simulated using Weather Research and Forecasting under three different scenarios. Case 1 has realistic LULC representation of Kanpur, while the grids representing the Kanpur urban region were replaced by cropland LULC pattern in Case 2. Comparison illustrated that urban heat island effect caused convergence of winds and moisture in the lower troposphere, which enhances convection over urban region and induced more rainfall over the urban core compared to upwind regions. Case 3 is similar to Case 1 but lower aerosol concentration (by a factor of 100) over the storm region. Analysis shows that aerosol‐induced microphysical changes delay the initiation of warm rain (over the upwind region) but enhance ice phase particle formation in latter stages (over the urban and downwind regions) resulting in increase in downwind rainfall.
Watershed System Model: The Essentials to Model Complex Human‐Nature System at the River Basin Scale
Authors: Li Xin , Cheng Guodong , Lin Hui , Cai Ximing , Fang Miao , Ge Yingchun , Hu Xiaoli , Chen Min , Li Weiyue 
Published: March 2018

AbstractWatershed system models are urgently needed to understand complex watershed systems and to support integrated river basin management. Early watershed modeling efforts focused on the representation of hydrologic processes, while the next‐generation watershed models should represent the coevolution of the water‐land‐air‐plant‐human nexus in a watershed and provide capability of decision‐making support. We propose a new modeling framework and discuss the know‐how approach to incorporate emerging knowledge into integrated models through data exchange interfaces. We argue that the modeling environment is a useful tool to enable effective model integration, as well as create domain‐specific models of river basin systems. The grand challenges in developing next‐generation watershed system models include but are not limited to providing an overarching framework for linking natural and social sciences, building a scientifically based decision support system, quantifying and controlling uncertainties, and taking advantage of new technologies and new findings in the various disciplines of watershed science. The eventual goal is to build transdisciplinary, scientifically sound, and scale‐explicit watershed system models that are to be codesigned by multidisciplinary communities.
Flux and Seasonality of Dissolved Organic Matter From the Northern Dvina (Severnaya Dvina) River, Russia
Authors: Johnston Sarah Ellen , Shorina Natalia , Bulygina Ekaterina , Vorobjeva Taisya , Chupakova Anna , Klimov Sergey I. , Kellerman Anne M. , Guillemette Francois , Shiklomanov Alexander , Podgorski David C. , Spencer Robert G. M. 
Published: March 2018

AbstractPan‐Arctic riverine dissolved organic carbon (DOC) fluxes represent a major transfer of carbon from land‐to‐ocean, and past scaling estimates have been predominantly derived from the six major Arctic rivers. However, smaller watersheds are constrained to northern high‐latitude regions and, particularly with respect to the Eurasian Arctic, have received little attention. In this study, we evaluated the concentration of DOC and composition of dissolved organic matter (DOM) via optical parameters, biomarkers (lignin phenols), and ultrahigh resolution mass spectrometry in the Northern Dvina River (a midsized high‐latitude constrained river). Elevated DOC, lignin concentrations, and aromatic DOM indicators were observed throughout the year in comparison to the major Arctic rivers with seasonality exhibiting a clear spring freshet and also some years a secondary pulse in the autumn concurrent with the onset of freezing. Chromophoric DOM absorbance at a350 was strongly correlated to DOC and lignin across the hydrograph; however, the relationships did not fit previous models derived from the six major Arctic rivers. Updated DOC and lignin fluxes were derived for the pan‐Arctic watershed by scaling from the Northern Dvina resulting in increased DOC and lignin fluxes (50 Tg yr−1 and 216 Gg yr−1, respectively) compared to past estimates. This leads to a reduction in the residence time for terrestrial carbon in the Arctic Ocean (0.5 to 1.8 years). These findings suggest that constrained northern high‐latitude rivers are underrepresented in models of fluxes based from the six largest Arctic rivers with important ramifications for the export and fate of terrestrial carbon in the Arctic Ocean.
Average information‐weighted consensus filter for target tracking in distributed sensor networks with naivety issues
Authors: Yao Peng , Liu Gang , Liu Yanfei 
Published: March 2018

SummaryIn the consensus‐based state estimation, multiple neighboring nodes iteratively exchange their local information with each other and the goal is to get more accurate and more convergent state estimation on each node. In order to improve network scalability and fault tolerance, the distributed sensor networks are desirable because the requirements of the fusion node are eliminated. However, the state estimation becomes challenging in the case of limited sensing regions and/or distinct measurement‐noise covariances. A novel distributed average information‐weighted consensus filter (AICF) is proposed, which does not require the knowledge of the total number of sensor nodes. Based on the weighted average consensus, AICF effectively addresses the naivety issues caused by unequal measurement‐noise covariances. Theoretical analysis and experimental verification show that AICF can approach the optimal centralized state estimation.
Lithiation/Delithiation Synthesis of Few Layer Silicene Nanosheets for Rechargeable Li–O2 Batteries
Authors: Zhang Wenyu , Sun Libo , Nsanzimana Jean Marie Vianney , Wang Xin 
Published: March 2018

AbstractSilicene has recently received increasing interest due to its unique properties. However, the synthesis of silicene remains challenging, which limits its wide applications. In this work, a top‐down lithiation and delithiation process is developed to prepare few layer silicene‐like nanosheets from ball‐milled silicon nanopowders. It is found that delithiation solvent plays a critical role in the structure evolution of the final products. The use of isopropyl alcohol renders 2D silicene‐like products 30–100 nm in length and ≈2.4 nm in thickness. The electrochemical characterization analysis suggests that the product shows high performance for rechargeable Li–O2 batteries with 73% energy efficiency and high stability. The top‐down synthesis strategy proposed in this work not only provides a new solution to the challenging preparation issue of few layer silicene but also demonstrates the feasibility of producing 2D materials from nonlayered starting structures.
Nanomaterials for Cancer Precision Medicine
Authors: Wang Yilong , Sun Shuyang , Zhang Zhiyuan , Shi Donglu 
Published: March 2018

AbstractMedical science has recently advanced to the point where diagnosis and therapeutics can be carried out with high precision, even at the molecular level. A new field of “precision medicine” has consequently emerged with specific clinical implications and challenges that can be well‐addressed by newly developed nanomaterials. Here, a nanoscience approach to precision medicine is provided, with a focus on cancer therapy, based on a new concept of “molecularly‐defined cancers.” “Next‐generation sequencing” is introduced to identify the oncogene that is responsible for a class of cancers. This new approach is fundamentally different from all conventional cancer therapies that rely on diagnosis of the anatomic origins where the tumors are found. To treat cancers at molecular level, a recently developed “microRNA replacement therapy” is applied, utilizing nanocarriers, in order to regulate the driver oncogene, which is the core of cancer precision therapeutics. Furthermore, the outcome of the nanomediated oncogenic regulation has to be accurately assessed by the genetically characterized, patient‐derived xenograft models. Cancer therapy in this fashion is a quintessential example of precision medicine, presenting many challenges to the materials communities with new issues in structural design, surface functionalization, gene/drug storage and delivery, cell targeting, and medical imaging.
Preparation and the swelling properties of sodium alginate graft poly (acrylic acid‐co‐2‐acrylamide‐2‐methyl propane sulfonic acid)/graphene oxide hydrogel composite
Authors: Zhu Linhui , Liu Yangwenyi , Wang Fangyuan , He Tengteng , Tang Yaoji , Yang Jing 
Published: March 2018

AbstractSodium alginate graft poly (acrylic acid‐co‐2‐acrylamide‐2‐methyl propane sulfonic acid)/graphene oxide (SA‐g‐P(AA‐co‐AMPS)/GO) hydrogel composite is prepared. The composite is characterized by infrared (IR) spectroscopy, X‐ray diffraction (XRD), high‐resolution scanning electron microscope (HRSEM), and differential scanning calorimetry (DSC). The swelling properties of the composite are investigated. GO acts as part of the cross‐linking points, which improves the swelling property of the composite. Maximal amount of absorption capacity in water and 0.9% NaCl is 862.3 and 164.7 g/g, respectively, with a GO content of 5 wt% of total mass of monomers. However, the absorption of water and 0.9% NaCl is only 390.3 and 52.5 g/g, respectively, without the incorporation of GO. Water retention properties of the composite are also tested.
Hierarchical Co‐Assembly Enhanced Direct Ink Writing
Authors: Li Longyu , Zhang Pengfei , Zhang Zhiyun , Lin Qianming , Wu Yuyang , Cheng Alexander , Lin Yunxiao , Thompson Christina M. , Smaldone Ronald A. , Ke Chenfeng 
Published: March 2018

AbstractIntegrating intelligent molecular systems into 3D printing materials and transforming their molecular functions to the macroscale with controlled superstructures will unleash great potential for the development of smart materials. Compared to macromolecular 3D printing materials, self‐assembled small‐molecule‐based 3D printing materials are very rare owing to the difficulties of facilitating 3D printability as well as preserving their molecular functions macroscopically. Herein, we report a general approach for the integration of functional small molecules into 3D printing materials for direct ink writing through the introduction of a supramolecular template. A variety of inorganic and organic small‐molecule‐based inks were 3D‐printed, and their superstructures were refined by post‐printing hierarchical co‐assembly. Through spatial and temporal control of individual molecular events from the nano‐ to the macroscale, fine‐tuned macroscale features were successfully installed in the monoliths.
A Paper Sensor Printed with Multifunctional Bio/Nano Materials
Authors: Hui Christy Y. , Liu Meng , Li Yingfu , Brennan John D. 
Published: March 2018

AbstractWe report a paper‐based aptasensor platform that uses two reaction zones and a connecting bridge along with printed multifunctional bio/nano materials to achieve molecular recognition and signal amplification. Upon addition of analyte to the first zone, a fluorescently labelled DNA or RNA aptamer is desorbed from printed graphene oxide, rapidly producing an initial fluorescence signal. The released aptamer then flows to the second zone where it reacts with printed reagents to initiate rolling circle amplification, generating DNA amplicons containing a peroxidase‐mimicking DNAzyme, which produces a colorimetric readout that can be read in an equipment‐free manner or with a smartphone. The sensor was demonstrated using an RNA aptamer for adenosine triphosphate (a bacterial marker) and a DNA aptamer for glutamate dehydrogenase (Clostridium difficile marker) with excellent sensitivity and specificity. These targets could be detected in spiked serum or feacal samples, demonstrating the potential for testing clinical samples.
Emulsion‐polymerized polyindole nanoparticles and their electrorheology
Authors: Park In Hye , Kwon Seung Hyuk , Choi Hyoung Jin 
Published: March 2018

ABSTRACTPolyindole (PIn) nanoparticles were synthesized through an emulsion polymerization technique in this study and then examined as an anhydrous semi‐conducting electro‐responsive material. Their surface morphology and chemical structure were observed with high‐resolution scanning electron microscopy and Fourier transform infrared spectroscopy, respectively. When dispersed in silicone oil, the electrorheological (ER) properties of the PIn particles were examined using a rotational rheometer with both steady shear and oscillatory tests under various applied electric field strengths with direct observation using an optical microscope. Flow curves of shear stress as a function of shear rate were well fitted using the Cho‐Choi‐Jhon model. Dielectric analysis was also performed to examine the permittivity and loss factor in relation to the ER effect. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46384.
Controllably Confined ZnO on USY Zeolites (USY@ZnO/Al2O3) as Efficient Lewis Acid Catalysts for Baeyer–Villiger Oxidation
Authors: Wang Bo , Xu Hao , Ding Yu , Zhu Zhiguo , Wang Darui , Guan Yejun , Wu Haihong , Wu Peng 
Published: March 2018

AbstractA ZnAl‐LDHs (layered double hydroxides) phase was readily formed on the surface of a USY zeolite through a distinctive in situ growth method that benefitted from the interaction of the added Zn source and aluminum species extracted from the Al‐rich USY zeolite crystals. The migration of aluminum and simultaneous interaction with the external Zn source took place in one pot to form a ZnAl‐LDHs phase coated on the surface of the USY crystals. Upon calcination, the ZnAl‐LDHs phase was transformed into a ZnO/Al2O3 composite that was still firmly anchored on the USY zeolite, without sacrificing the core–shell structure. The resultant USY@ZnO/Al2O3 materials gave rise to unique Lewis acidity and hierarchical porosity, which endowed the catalyst with promising performance in the Baeyer–Villiger oxidation of ketones with H2O2 or bulky tert‐butyl hydroxide as an oxidant.
Sustainable scenarios for alkaline protein extraction from leafy biomass using green tea residue as a model material
Authors: Zhang Chen , Slegers Petronella M. , Wisse Jacobus , Sanders Johan P.M. , Bruins Marieke E. 
Published: March 2018

AbstractLeaf protein can be extracted cost‐efficiently using 0.1 mol dm−3 NaOH, but this process is less sustainable due to the generation of large amounts of sodium salts. KOH or Ca(OH)2 are considered as replacements for NaOH, as these salts can be reused. This work evaluates the economic and environmental sustainability of weak alkaline pectin extraction followed by KOH enhanced protein extraction, and Viscozyme® L‐aided pectin extraction followed by Ca(OH)2 enhanced protein extraction. The evaluations are made for green tea residue and are compared to related processes using NaOH. The predicted profits using KOH are comparable to those using NaOH. Environmental sustainability improves for all impact categories in the case of KOH extraction. Further environmental benefits are obtained by substituting conventional K fertilizer with the K‐rich salty waste water from the extraction process. The profits of the process using Ca(OH)2 are highly dependent on the extraction yield of the protein product. Protein extraction yields using Ca(OH)2 need to be higher than 70% to be more profitable than the same process with NaOH. The environmental benefits of Ca(OH)2 extraction include the absence of salty waste water and the net production of heat. This is accompanied by increased electricity consumption. Thus, the impact categories of climate change, fossil and water depletion, and particulate matter formation worsen. Photochemical oxidant formations remain the same, while the other impacts improve. This work has shown the potential and bottlenecks of NaOH, KOH and Ca(OH)2 protein extraction on different types of biomass in terms of environmental and economic sustainability. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd