bluuebunny/crossref_metadata_2025_split huggingface dataset:
GRACE Detected Rise of Groundwater in the Sahelian Niger River Basin
Authors: Werth S. , White D. , Bliss D. W. 
Published: November 2017

AbstractWest African regions along the Niger River experience climate and land cover changes that affect hydrological processes and therewith the distribution of fresh water resources (WR). This study provides an investigation of long‐term changes in terrestrial water storages (TWS) of the Niger River basin and its subregions by analyzing a decade of satellite gravity data from the Gravity Recovery and Climate Experiment (GRACE) mission. The location of large trends in TWS maps of differently processed GRACE solutions points to rising groundwater stocks. Soil moisture data from a global land surface model allow separating the effect of significantly increasing amount of WR from that of TWS variations. Surface water variations from a global water storage model validated with observations from altimetry data were applied to estimate the groundwater component in WR. For the whole Niger, a rise in groundwater stocks is estimated to be 93 ± 61 km3 between January 2003 and December 2013. A careful analysis of uncertainties in all data sets supports the significance of the groundwater rise. Our results confirm previous observations of rising water tables, indicating that effects of land cover changes on groundwater storage are relevant on basin scales. Areas with rising water storage are stocking a comfortable backup to mitigate possible future droughts and to deliver water to remote areas. This has implications for Niger water management strategies. Increasing groundwater recharges may be accompanied by reduction in water quality. This study helps to inform authority's decision to mitigate its negative impacts on local communities.
FDTD Modeling of LEMP Propagation in the Earth‐Ionosphere Waveguide With Emphasis on Realistic Representation of Lightning Source
Authors: Tran Thang H. , Baba Yoshihiro , Somu Vijaya B. , Rakov Vladimir A. 
Published: November 2017

AbstractThe finite difference time domain (FDTD) method in the 2‐D cylindrical coordinate system was used to compute the nearly full‐frequency‐bandwidth vertical electric field and azimuthal magnetic field waveforms produced on the ground surface by lightning return strokes. The lightning source was represented by the modified transmission‐line model with linear current decay with height, which was implemented in the FDTD computations as an appropriate vertical phased‐current‐source array. The conductivity of atmosphere was assumed to increase exponentially with height, with different conductivity profiles being used for daytime and nighttime conditions. The fields were computed at distances ranging from 50 to 500 km. Sky waves (reflections from the ionosphere) were identified in computed waveforms and used for estimation of apparent ionospheric reflection heights. It was found that our model reproduces reasonably well the daytime electric field waveforms measured at different distances and simulated (using a more sophisticated propagation model) by Qin et al. (2017). Sensitivity of model predictions to changes in the parameters of atmospheric conductivity profile, as well as influences of the lightning source characteristics (current waveshape parameters, return‐stroke speed, and channel length) and ground conductivity were examined.
Using Cell‐Phone Tower Signals for Detecting the Precursors of Fog
Authors: David N. , Gao H. O. 
Published: November 2017

AbstractIn the last decade, published research has indicated the potential of commercial microwave links that comprise the data transmission infrastructure of cellular communication networks as an environmental monitoring technology. Different weather phenomena cause interference in the wireless communication links that can therefore essentially act as a low‐cost sensor network, already deployed worldwide, for atmospheric monitoring. In this study we focus on the attenuation effect caused in commercial microwave networks due to gradients in the atmospheric refractive index with altitude as a result of the combination of temperature inversions and falls in the atmospheric humidity trapped beneath them. These conditions, when combined with high relative humidity near ground level, are precursors to the creation of fog. The current work utilizes this novel approach to demonstrate the potential for detecting these preconditions of fog, a phenomenon associated with severe visibility limitations that can lead to dangerous accidents, injuries, and loss of lives.
Prominent Midlatitude Circulation Signature in High Asia's Surface Climate During Monsoon
Authors: Mölg Thomas , Maussion Fabien , Collier Emily , Chiang John C. H. , Scherer Dieter 
Published: November 2017

AbstractHigh Asia has experienced strong environmental changes in recent decades, as evident in records of glaciers, lakes, tree rings, and vegetation. The multiscale understanding of the climatic drivers, however, is still incomplete. In particular, few systematic assessments have evaluated to what degree, if at all, the midlatitude westerly circulation modifies local surface climates in the reach of the Indian Summer Monsoon. This paper shows that a southward shift of the upper‐tropospheric westerlies contributes significantly to climate variability in the core monsoon season (July–September) by two prominent dipole patterns at the surface: cooling in the west of High Asia contrasts with warming in the east, while moist anomalies in the east and northwest occur with drying along the southwestern margins. Circulation anomalies help to understand the dipoles and coincide with shifts in both the westerly wave train and the South Asian High, which imprint on air mass advection and local energy budgets. The relation of the variabilities to a well‐established index of midlatitude climate dynamics allows future research on climate proxies to include a fresh hypothesis for the interpretation of environmental changes.
Gravity Wave Dynamics in a Mesospheric Inversion Layer: 2. Instabilities, Turbulence, Fluxes, and Mixing
Authors: Fritts David C. , Wang Ling , Laughman Brian , Lund Thomas S. , Collins Richard L. 
Published: November 2017

AbstractA companion paper by Fritts, Laughman, et al. (2017) employed an anelastic numerical model to explore the dynamics of gravity waves (GWs) encountering a mesospheric inversion layer (MIL) having a moderate static stability enhancement and a layer of weaker static stability above. That study revealed that MIL responses, including GW transmission, reflection, and instabilities, are sensitive functions of GW parameters. This paper expands on two of the Fritts, Laughman, et al. (2017) simulations to examine GW instability dynamics and turbulence in the MIL; forcing of the mean wind and stability environments by GW, instability, and turbulence fluxes; and associated heat and momentum transports. These direct numerical simulations resolve turbulence inertial‐range scales and yield the following results:

GW breaking and turbulence in the MIL occur below where they would otherwise, due to enhancements of GW amplitudes and shears in the MIL.
2‐D GW and instability heat and momentum fluxes are ~20–30 times larger than 3‐D instability and turbulence fluxes.
Mean fields are driven largely by 2‐D GW and instability dynamics rather than 3‐D instabilities and turbulence.
2‐D and 3‐D heat fluxes in regions of strong turbulence yield small departures from initial T(z) and N2(z) profiles, hence do not yield nearly adiabatic “mixed” layers.
Our MIL results are consistent with the relation between the turbulent vertical velocity variance and energy dissipation rate proposed by Weinstock (1981) for the limited intervals evaluated.
Discovery, Controls, and Hazards of Widespread Deep‐Seated Gravitational Slope Deformation in the Etsumi Mountains, Central Japan
Authors: Kaneda Heitaro , Kono Taiyo 
Published: November 2017

AbstractDeep‐seated gravitational slope deformation (DSGSD) is a largely unnoticed but important long‐term mass wasting process that may result in catastrophic failure of mountain slopes. Manifested by small topographic irregularities such as ridge‐parallel scarps and linear depressions, it has been predominantly reported in alpine landscapes above timber lines. On the basis of area‐wide high‐resolution topographic data acquired by light detection and ranging (lidar) surveys, we here show that ~96% of existing gravitational scarps have been hidden under forest canopies in the Etsumi Mountains, central Japan. The scarps are surprisingly widespread over the mountains with a mean line density of as large as 0.87 km/km2. Our analyses of the scarp distribution suggest that uphill‐facing scarps are primary geomorphic signals of DSGSD with a destabilized rock mass larger than ~105 m2, whereas downhill‐facing scarps principally occur in response to more localized slope deformation. In terms of controls, topography is by far the most influential factor in triggering and promoting DSGSD. Despite theM7.5 earthquake in 1891, impact of large local earthquakes proves to be not very strong. Comparison with preexisting landslide maps further suggests that DSGSD and large‐scale landslides are not different slope processes but represent different stages of the same process. Our results highlight limitations of aerial‐photograph interpretation in forest‐covered mountains and the need for lidar‐assisted mapping for deeper understanding of this long‐term process and interactions between surface and tectonic processes.
Formation, Fate, and Impacts of Microscopic and Macroscopic Oil‐Sediment Residues in Nearshore Marine Environments: A Critical Review
Authors: Gustitus Sarah A. , Clement T. Prabhakar 
Published: November 2017

AbstractCrude oil that is spilled in marine environments often interacts with suspended sediments to form residues that can impact the recovery of the affected nearshore ecosystems. When spilled oil and sediment interact, they can form either small microscopic aggregates, commonly referred to as oil‐particle aggregates, or large macroscopic agglomerates, referred to as sediment‐oil agglomerates or sediment‐oil mats. Although these different sized oil‐sediment residues have similar compositions, they are formed under different conditions and have different fates in nearshore environments; the goal of this review is to synthesize our current understanding of these two types of residues. We believe that researchers who focus solely on studying either microscopic aggregates or macroscopic agglomerates could benefit from understanding the research findings available in the other field. In this study, we compare and contrast various processes that control the formation, fate, and impacts of these two types of residues in nearshore environments and point out some of the knowledge gaps in this field. Additionally, these residues have been referred to by many names in the past, leading to confusion and misconceptions at times. In this effort, we recommend a uniform nomenclature to distinguish them based on their physical size. Our overall aim is to bridge the gap between microscopic and macroscopic oil‐sediment residue literature to foster a robust exchange of ideas, which we believe can lead to the development of efficient strategies for managing oil spills that affect nearshore environments.
Microwave‐Assisted Synthesis of Benzimidazole‐Linked Indoline and Indole Hybrids from C‐2 Linked (o‐Aminobenzyl)benzimidazoles
Authors: Lee Yun‐Ta , Chiu Feng‐Yu , Barve Indrajeet J. , Sun Chung‐Ming 
Published: November 2017

AbstractAn efficient and novel synthesis of benzimidazole‐linked indoline hybrids via an unconventional Pictet‐Spengler‐type condensation of C‐2 linked (o‐aminobenzyl)benzimidazoles with aldehydes and ketones under microwave irradiation has been explored. The key condensation step consists of acid‐catalyzed imine generation followed by intramolecular C–C bond formation through unique reactivity of the benzimidazole moiety. The scope of this method is further extended to synthesize tetracyclic pyrroloindole benzimidazole‐carboxylates through 2‐carboxaldehydes.magnified image
Copper/Iron‐Cocatalyzed Cascade Perfluoroalkylation/Cyclization of 1,6‐Enynes with Iodoperfluoroalkanes
Authors: Xia Xiao‐Feng , Yu Jipan , Wang Dawei 
Published: November 2017

AbstractA copper/iron‐cocatalyzed fluoroalkylative cyclization of 1,6‐enynes with readily available iodoperfluoroalkanes reagents for the synthesis of the corresponding fluoroalkylated pyrrolidines and benzofuran derivatives is reported. This novel protocol provides a mild method for the construction of Csp3‐CF2 and exocyclic double bonds in one step with high regio‐ and stereo‐selectivities.magnified image
Copper‐Catalyzed Dehydrative Cyclization of 1‐(2‐Hydroxyphenyl)propargyl Alcohols with P(O)H Compounds for the Synthesis of 2‐Phosphorylmethylbenzofurans
Authors: Zhang Ming , Yang Jianlin , Xu Qing , Dong Chao , Han Li‐Biao , Shen Ruwei 
Published: November 2017

AbstractA tetrakis(acetonitrile)copper(I) hexafluorophosphate [Cu(MeCN)PF6]‐catalyzed dehydrative reaction of 1‐(2‐hydroxyphenyl)propargyl alcohols with diarylphosphine oxides has been developed to provide an efficient synthesis of phosphorylated benzofurans in good to high yields. In the presence of a catalytic amount of an organic base, a variety of H‐phosphonates and H‐phosphinates can also be employed as good substrates to produce the corresponding products in moderate yields. The reaction has significant economical and ecological advantages since the formation of a new C(sp3)–P bond and the benzofuran framework could both be achieved using an inexpensive copper catalyst with water produced as the sole by‐product. Some synthetic transformations of the product have also been demonstrated.magnified image
Occupational cholangiocarcinoma caused by exposure to 1,2‐dichloropropane and/or dichloromethane
Authors: Kubo Shoji , Takemura Shigekazu , Tanaka Shogo , Shinkawa Hiroji , Kinoshita Masahiko , Hamano Genya , Ito Tokuji , Koda Masaki , Aota Takanori 
Published: November 2017

AbstractA cluster of cholangiocarcinoma among printing company workers who were exposed to 1,2‐dichloropropane and/or dichloromethane was classified by the Ministry of Health, Labour and Welfare of Japan on 1 October 2013 as “occupational cholangiocarcinoma”. At the time of the diagnosis of cholangiocarcinoma, levels of γ‐glutamyl transferase, and aspartate and alanine aminotransferases were elevated, and had been elevated in some patients several years prior to the diagnosis. Regional dilatation of intrahepatic bile ducts without tumor‐induced obstruction was characteristic in diagnostic imaging. Pathological examination found chronic bile duct injury with DNA damage, precancerous/preinvasive lesions such as biliary intraepithelial neoplasia and intraductal papillary neoplasm of the bile duct in various sites of the large bile ducts, and invasive cholangiocarcinoma such as mass‐forming type and intraductal growth‐type intrahepatic cholangiocarcinoma and mainly papillary‐type extrahepatic cholangiocarcinoma. Whole‐exome analysis of the cancerous tissues showed hypermutation, substantial strand bias, and unique trinucleotide mutational changes. Patients seemed to suffer high incidence of postoperative complications including intra‐abdominal, which might be related to chronic bile duct injury. Postoperative recurrence from multicentric origins occurred in some patients, as DNA‐injured bile ducts have high carcinogenic potential. Aggressive treatment, including second resections for such multicentric recurrences, appeared to be effective. In 2014, the International Agency for Research on Cancer classified 1,2‐dichloropropane as Group 1 (carcinogenic to humans) and dichloromethane as Group 2A (probably carcinogenic to humans) carcinogens.
4′,5′‐Bis(dimethylamino)fluorescein Exhibits pH‐Dependent Emission Behavior Distinct From That of Fluorescein
Authors: Hwang Jun Yeon , Shim Sangdeok , Hwang Gil Tae 
Published: November 2017

Abstract4′,5′‐Diaminofluoresein (DAF) and 4′,5′‐bis(dimethylamino)fluorescein (BDMAF) have been synthesized and their pH‐dependent photophysical properties and protolytic equilibria investigated. Although the parent fluorescein exhibits decreased emission upon decreasing pH, DAF displayed quenched emission at all pH values; surprisingly, BDMAF exhibited strong fluorescence only at pH 3–6, with its emission almost completely quenched under strongly acidic, neutral, and basic conditions.
Superhydrophobic PES/PDA/ODTS fibrous mat prepared by electrospinning and silanization modification for oil/water separation
Authors: Cao Sujiao , Qiu Fang , Xiong Chen , Wang Xiaojun , Zhang Gang , Long Shengru , Yang Jie 
Published: November 2017

ABSTRACTWith polydopamine (PDA) acting as interlayer, combined with electrospinning technology and a silanization method, here a versatile method for fabricating a superhydrophobic PES/PDA/ODTS fibrous mat is reported. Scanning electron microscopy, attenuated total reflection Fourier transform infrared spectroscopy, and contact angle measurements were applied to characterize the morphologies and chemical composition changes of the prepared fibrous mats. Their separation ability for oil/water mixtures was measured by self‐made instruments. The results show that the fabricated PES/PDA/ODTS fibrous mat displays a water contact angle too large to be assessed by the ordinary amount of water applied in a conventional measurement. In other words, a water drop of less than 10 μL adheres to the syringe needle and leaves with it during the measurement. The prepared PES/PDA/ODTS fibrous mat also shows a threshold sliding angle no more than 2.5°. At the same time, this kind of material exhibits superoleophilicity for organic solvents, such as n‐hexane, gasoline, toluene, and chloroform. The experimental contact angles were also analyzed using the Cassie–Baxter model to gain insights into the fundamental microstructure–wetting property relationship. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45923.
Prediction of plasticity‐controlled failure in polyamide 6: Influence of temperature and relative humidity
Authors: Parodi Emanuele , Peters Gerrit W. M. , Govaert Leon E. 
Published: November 2017

ABSTRACTIn this study, the influence of temperature and relative humidity on the plasticity controlled failure of polyamide 6 was investigated. Uniaxial tensile tests were performed at several temperatures, strain rates, and relative humidity; creep tests were performed at different relative humidity and applied load. In order to describe and predict the yield kinetics, the Ree–Eyring equation was employed and modified to include the effect of relative humidity. Subsequently, by the introduction of the concept of critical amount of accumulated plastic strain, the yield kinetics were successfully translated to predictions of time‐to‐failure. A good agreement between predictions and experimental results is obtained, showing that the model is a suitable and versatile tool to evaluate mechanical performance of a temperature and moisture sensitive material such as polyamide 6. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45942.
The stochastic effect of polydispersity on polymeric DNA delivery vectors
Authors: Wong Sharon Y. , Putnam David 
Published: November 2017

ABSTRACTThe molecular composition and architecture of polymeric DNA delivery reagents govern their transfection efficiency. One parameter that is understudied is the influence of polydispersity on transfection efficiency. Here we report the synthesis of two molecularly identical polymer series, but with different polydispersities (1.3 vs. 2.0) and quantify the effect polydispersity on transfection efficiency. The results show that the effect of polydispersity on transfection efficiency in cell culture is not predictable and is stochastic in nature. In general terms, polymers with high polydispersity mediated higher levels of transfection in vitro compared to low polydispersity polymers with the same side chain distribution and composition. However, at higher molecular weights, the effect of polydispersity was polymer specific, with enhanced transfection efficiency in some cases, but negligible in others. An interesting outcome is that the higher polydispersity polymers generally enhanced the stability of polymer:DNA complexes and this enhancement generally correlated with enhanced transfection efficiency. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45965.
Development of biodegradable cellulose‐g‐poly(butyl acrylate)/kaolin nanocomposite with improved fire retardancy and mechanical properties
Authors: Jena Dharmendra K. , Sahoo Prafulla K. 
Published: November 2017

ABSTRACTThe main aim of the work is to convert a low cost renewable biopolymer to a high performance fire‐retardant biomaterial by modification via grafting. Cellulose, a linear and most abundant biomacromolecule, has gained increasing attention for its interesting properties and potential applications in the synthesis of polymer nanocomposites. Cellulose has been grafted with butyl acrylate via emulsifier free emulsion polymerization using in situ developed transition metal complex initiating system: CuSO4/glycine/ammonium persulfate with and without additive kaolin to prepare nanocomposites and copolymer, respectively. The morphology of so‐prepared grafted nanocomposites was characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, and field emission scanning electron microscopy. The enhancement in thermal behavior and mechanical properties of nanocomposites over copolymer were outstanding. The fire‐retardant properties were evaluated by limiting oxygen index and cone calorimetry test. The biodegradation and water absorbency of the fire‐retardant nanocomposites have been carried out for better commercialization and environmental concern. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45968.
Water‐induced degradations in MWCNT embedded glass fiber/epoxy composites: An emphasis on aging temperature
Authors: Prusty Rajesh Kumar , Rathore Dinesh Kumar , Ray Bankim Chandra 
Published: November 2017

ABSTRACTThis article is focused to elucidate the critical influence of diffusion temperature on the water uptake and subsequent degradation behavior of multi‐walled carbon nanotube embedded glass fiber/epoxy (MWCNT‐GE) composite. Presence of MWCNT in the glass fiber/epoxy (GE) composite significantly suppressed its water absorption propensity at lower aging temperature (25 °C). However, MWCNT reinforcement in GE composite adversely affected its high temperature water resistance due to generation of unfavorable thermal and hygroscopic stresses at the MWCNT/polymer interfaces. Effect of MWCNT and water diffusion temperature on the glass transition temperature and chemical bonding characteristics of GE composite have been verified by differential scanning calorimetry and Fourier transformed infrared spectroscopy. Flexural testing of the water saturated samples revealed that diffused water exerts more detrimental effect on mechanical performance of MWCNT‐GE composite than that of control GE composite. The extent of recovery in mechanical performance of the composites has also been evaluated after complete desorption of the water saturated samples. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45987.