bluuebunny/crossref_metadata_2025_split huggingface dataset:
TEMPORAL EVOLUTION OF CHROMOSPHERIC OSCILLATIONS IN FLARING REGIONS: A PILOT STUDY
Authors: Monsue T. , Hill F. , Stassun K. G. 
Published: September 2016

ABSTRACT
We have analyzed Hα intensity images obtained at a 1 minute cadence with the Global Oscillation Network Group (GONG) system to investigate the properties of oscillations in the 0–8 mHz frequency band at the location and time of strong M- and X-class flares. For each of three subregions within two flaring active regions, we extracted time series from multiple distinct positions, including the flare core and quieter surrounding areas. The time series were analyzed with a moving power-map analysis to examine power as a function of frequency and time. We find that, in the flare core of all three subregions, the low-frequency power (∼1–2 mHz) is substantially enhanced immediately prior to and after the flare, and that power at all frequencies up to 8 mHz is depleted at flare maximum. This depletion is both frequency- and time-dependent, which probably reflects the changing depths visible during the flare in the bandpass of the filter. These variations are not observed outside the flare cores. The depletion may indicate that acoustic energy is being converted into thermal energy at flare maximum, while the low-frequency enhancement may arise from an instability in the chromosphere and provide an early warning of the flare onset. Dark lanes of reduced wave power are also visible in the power maps, which may arise from the interaction of the acoustic waves and the magnetic field.
A MULTI-RESOLUTION, MULTI-EPOCH LOW RADIO FREQUENCY SURVEY OF THE Kepler K2 MISSION CAMPAIGN 1 FIELD
Authors: Tingay S. J. , Hancock P. J. , Wayth R. B. , Intema H. , Jagannathan P. , Mooley K. 
Published: September 2016

ABSTRACT
We present the first dedicated radio continuum survey of a Kepler K2 mission field, Field 1, covering the North Galactic Cap. The survey is wide field, contemporaneous, multi-epoch, and multi-resolution in nature and was conducted at low radio frequencies between 140 and 200 MHz. The multi-epoch and ultra wide field (but relatively low resolution) part of the survey was provided by 15 nights of observation using the Murchison Widefield Array (MWA) over a period of approximately a month, contemporaneous with K2 observations of the field. The multi-resolution aspect of the survey was provided by the low resolution (4′) MWA imaging, complemented by non-contemporaneous but much higher resolution (20″) observations using the Giant Metrewave Radio Telescope (GMRT). The survey is, therefore, sensitive to the details of radio structures across a wide range of angular scales. Consistent with other recent low radio frequency surveys, no significant radio transients or variables were detected in the survey. The resulting source catalogs consist of 1085 and 1468 detections in the two MWA observation bands (centered at 154 and 185 MHz, respectively) and 7445 detections in the GMRT observation band (centered at 148 MHz), over 314 square degrees. The survey is presented as a significant resource for multi-wavelength investigations of the more than 21,000 target objects in the K2 field. We briefly examine our survey data against K2 target lists for dwarf star types (stellar types M and L) that have been known to produce radio flares.
L’immigration en Bulgarie : entre ingénierie sociale, libre circulation et rétablissement des clôtures aux frontières
Authors: Gruev Radoslav 
Published: September 2016

Le profil migratoire de la Bulgarie est en train de changer depuis quelques années. Une perspective socio-historique nous permet de suivre les tendances depuis le début du XX e siècle, en partant d’une période de préférence ethnique et de secours aux réfugiés, passant par une politique stricte de gestion étatique de toute forme de mobilité durant le régime communiste et en arrivant à une période contemporaine pluridimensionnelle. Dans les années 1990, la Bulgarie se transforme progressivement autour des mouvements migratoires, d’abord d’« un pays d’émigration » vers l’Occident, ensuite en devenant « un pays de transit » et se profilant actuellement comme un « pays d’immigration » en perspective. Cette tendance est reflétée par les politiques publiques adoptées dans le domaine depuis l’adhésion de la Bulgarie à l’Union européenne et reste très présente dans les débats quotidiens depuis la « crise des réfugiés syriens » de l’été 2013.
An Empirical Study of Reading Habits and Interests of Saudi University EFL Learners
Authors: Rajab Hussam , Al-Sadi Alhasan 
Published: September 2016

<p align="left">This small-scale, quantitative study investigated the reading habits and interests of Saudi English-as-a-foreign-language (EFL) students at a university-level preparatory year program (PYP). The study aimed to identify certain habits and preferences of EFL learners with regard to various personal practices of the reading process in first language (L1) as well as in second language (L2). The study utilized a custom-designed, 10-item questionnaire on a Likert scale format in order to gain more insights into the manners with which students may or may not approach reading. The participants were newly-registered, male and female students (<em>n=330</em>) on the university PYP course with mixed English Language proficiency. Analysis of the data collected using descriptive statistical tools indicated several issues relating to the reading habits in general, including students’ lack of interest as well as lack of motivation towards ‘academic reading’ in both L1 and L2. However, the analysis revealed a greater level of engagement in reading in social media contexts. The study has several implications for future research and pedagogy in EFL reading as well as implications for the EFL classroom. </p>
Degradation Kinetics Study of Alogliptin Benzoate in Alkaline Medium by Validated Stability-Indicating HPTLC Method
Authors: Bodiwala Kunjan Bharatkumar , Shah Shailesh , Thakor Jeenal , Marolia Bhavin , Prajapati Pintu 
Published: September 2016

Abstract
A rapid, sensitive, and stability-indicating high-performance thin-layer chromatographic method was developed and validated to study degradation kinetics of Alogliptin benzoate (ALG) in an alkaline medium. ALG was degraded under acidic, alkaline, oxidative, and thermal stress conditions. The degraded samples were chromatographed on silica gel 60F254-TLC plates, developed using a quaternary-solvent system (chloroform–methanol–ethyl acetate–triethyl amine, 9+1+1+0.5, v/v/v/v), and scanned at 278 nm. The developed method was validated per International Conference on Harmonization guidelines using validation parameters such as specificity, linearity and range, precision, accuracy, LOD, and LOQ. The linearity range for ALG was 100–500 ng/band (correlation coefficient = 0.9997) with an average recovery of 99.47%. The LOD and LOQ for ALG were 9.8 and 32.7 ng/band, respectively. The developed method was successfully applied for the quantitative estimation of ALG in its synthetic mixture with common excipients. Degradation kinetics of ALG in an alkaline medium was studied by degrading it under three different temperatures and three different concentrations of alkali. Degradation of ALG in the alkaline medium was found to follow first-order kinetics. Contour plots have been generated to predict degradation rate constant, half-life, and shelf life of ALG in various combinations of temperature and concentration of alkali using Design Expert software.
Polarity-dependent effect of humidity on the resistive switching characteristics of nonpolar devices
Authors: Yin Qiaonan , Wei Chunyang , Wei Qi , Chen Yan , Xia Yidong , Xu Bo , Yin Jiang , Liu Zhiguo 
Published: September 2016

Abstract
The roles of moisture in resistive switching (RS) devices are closely related to the RS mechanism. In principle, the nonpolar RS promises symmetric behaviors independent of the polarities of operating voltages. However, the effect of humidity on the RS characteristics of Pt/TiO2−

x
/Pt nonpolar cells is confirmed to be polarity-dependent. The positive electroforming threshold voltage decreases when humidity increases, whereas the negative one is unaffected. This asymmetric phenomenon can be attributed to the polarity-associated rule of current varying with humidity before electroforming. The voltage distribution in the device and then the electroforming threshold voltage are modified.
Thermal cyclic etching of silicon nitride using formation and desorption of ammonium fluorosilicate
Authors: Shinoda Kazunori , Izawa Masaru , Kanekiyo Tadamitsu , Ishikawa Kenji , Hori Masaru 
Published: September 2016

Abstract
Novel selective cyclic etching of SiN over SiO2 via the formation and desorption of ammonium fluorosilicate was developed. The formation of ammonium fluorosilicate was observed using X-ray photoelectron spectroscopy after hydrofluorocarbon-based radical exposure. Etching of SiN was observed after ammonium fluorosilicate was removed by thermal annealing. Cyclic etching tests were carried out by repeated radical exposure and thermal annealing. The etching depth increased on increasing the number of cycles. It was found that the cyclic etching is self-limiting because the etching depth does not depend on the radical exposure time but on the number of cycles.
Growth of epitaxial Mn and Zn codoped BiFeO3 thin films and an enhancement of photovoltage generated by a bulk photovoltaic effect
Authors: Nakashima Seiji , Takayama Kota , Shigematsu Koji , Fujisawa Hironori , Shimizu Masaru 
Published: September 2016

Abstract
Recently, the bulk photovoltaic effect of BiFeO3 (BFO) thin films has attracted much attention because of its above bandgap photovoltage for realizing novel photovoltaic devices. In this study, the epitaxial growth of 1-µm-thick Mn and Zn codoped BFO thin films has been demonstrated, and the effects of Mn and Zn codoping on the ferroelectric and bulk photovoltaic properties of the BFO thin films have been investigated. A 0.5% Mn and 0.5% Zn codoped BFO (BFMZO050) thin film on a SrRuO3-buffered vicinal-SrTiO3(001) substrate showed an atomically flat surface with a step-and-terrace structure, a low leakage current of 1.5 × 10−6 A/cm2 at 100 kV/cm, and well-saturated ferroelectric electric displacement–electric field (D–E) hysteresis loops. In addition, a Pt/BFMZO/Pt coplanar capacitor with an interelectrode distance of 260 µm illuminated by a violet laser (λ = 405 nm) showed an enhanced photovoltage of 145 V owing to the reduction in photoconductance by Mn and Zn codoping.
Superconductivity of metal-induced surface reconstructions on silicon
Authors: Uchihashi Takashi 
Published: September 2016

Abstract
Recent progress in superconducting metal-induced surface reconstructions on silicon is reviewed, mainly focusing on the results of the author’s group. After a brief introduction of an ultrahigh-vacuum (UHV)–low-temperature (LT)-compatible electron transport measurement system, direct observation of the zero resistance state for the Si(111)–(

)-In surface is described, which demonstrates the existence of a superconducting transition in this class of two-dimensional (2D) materials. The measurement and analysis of the temperature dependence of the critical current density indicate that a surface atomic step works as a Josephson junction. This identification is further confirmed by LT-scanning tunneling microscopy (STM) observation of Josephson vortices trapped at atomic steps on the Si(111)–(

)-In surface. These experiments reveal unique features of metal-induced surface reconstructions on silicon that may be utilized to explore novel superconductivity.
Long‐lasting seismic repeaters in the Central Basin of the Main Marmara Fault
Authors: Schmittbuhl J. , Karabulut H. , Lengliné O. , Bouchon M. 
Published: September 2016

AbstractThe Main Marmara Fault which crosses the whole Marmara Sea is a significant seismic gap along the North Anatolian Fault. Here we show that nine long‐lasting strike‐slip seismic repeaters exist below the Central Basin within the seismogenic zone, in a 10 km region where deep creep was previously suggested from the analysis of the local seismicity. The typical recurrence time was 8 months during the 2008–2015 period. The cumulative slip of the repeating sequence appears to be compatible with the regional geodetic slip rate if they are assumed to be part of a large single asperity (10 km). The repeaters also exhibit short‐term crises and are possibly related to bursts of creep.
Simultaneous observations of storm‐generated sprite and gravity wave over Bangladesh
Authors: Chou Chien‐Chung , Dai Jeff , Kuo Cheng‐Ling , Huang Tai‐Yin 
Published: September 2016

AbstractWe report simultaneous observations of sprite and gravity wave generated by a storm over Bangladesh. The origin of a concentric gravity wave can be traced to the storm region on 27 April 2014 over Bangladesh with a low cloud top surface temperature (175 K). After data analysis, the time period of the concentric gravity wave is found to be 8.8–8.9 min. The horizontal wavelength is found to be ~50 km for red emissions (~55 km for green emissions), and the horizontal phase velocity is 94.4 ± 31.7 m s−1 for red emissions (102.6 ± 29.4 m s−1 for green emissions). Using the dispersion relation of gravity wave, the elevation angle of wave propagation direction is found to be ~53.3°. The sprite associated with the gravity wave was also recorded at 1534 UT on 27 April 2014. The initiation time of storm‐generated gravity wave is estimated to be 1454 UT at which lightning activity was relatively low using lightning data. At time 1534 UT of the recorded sprite, the lightning rate was close to its maximum value. The storm‐generated gravity wave could be thought as a precursor phenomenon for lightning and sprites since one of the necessary conditions for gravity wave, lightning, and sprites is strong convection inside storms.
Observed subseasonal variability of heat flux and the SST response of the tropical Indian Ocean
Authors: Raj Parampil Sindu , Bharathraj G. N. , Harrison Matthew , Sengupta Debasis 
Published: September 2016

AbstractWe develop an experimental daily surface heat flux data set based on satellite observations to study subseasonal variability (periods shorter than 90 days) in the tropical Indian Ocean. We use incoming shortwave and longwave radiation from the International Satellite Cloud Climatology Project, and sea surface temperature (SST) from microwave sensors, to estimate net radiative flux. Latent and sensible heat fluxes are estimated from scatterometer winds and near‐surface air temperature and specific humidity from Atmospheric Infrared Sounder (AIRS) observations calibrated to buoy data. Seasonal biases in net heat flux are generally within 10 W m−2 of estimates from moorings, and the phases and amplitudes of subseasonal variability of heat fluxes are realistic. We find that the contribution of subseasonal changes in air‐sea humidity gradients to latent heat flux equals or exceeds the contribution of subseasonal changes in wind speed in all seasons. SST responds coherently to subseasonal oscillations of net heat flux associated with active and suppressed phases of atmospheric convection in the summer hemisphere. Thus, subseasonal SST changes are mainly forced by heat flux in the northeast Indian Ocean in northern summer, and in the 15°S–5°N latitude belt in southern summer. In the winter hemisphere, subseasonal SST changes are not a one‐dimensional response to heat flux, implying that they are mainly due to oceanic advection, entrainment, or vertical mixing. The coherent evolution of subseasonal SST variability and surface heat flux suggests active coupling between SST and large‐scale, organized tropical convection in the summer season.
A numerical model for water and heat transport in freezing soils with nonequilibrium ice‐water interfaces
Authors: Peng Zhenyang , Tian Fuqiang , Wu Jingwei , Huang Jiesheng , Hu Hongchang , Darnault Christophe J. G. 
Published: September 2016

AbstractA one‐dimensional numerical model of heat and water transport in freezing soils is developed by assuming that ice‐water interfaces are not necessarily in equilibrium. The Clapeyron equation, which is derived from a static ice‐water interface using the thermal equilibrium theory, cannot be readily applied to a dynamic system, such as freezing soils. Therefore, we handled the redistribution of liquid water with the Richard's equation. In this application, the sink term is replaced by the freezing rate of pore water, which is proportional to the extent of supercooling and available water content for freezing by a coefficient, β. Three short‐term laboratory column simulations show reasonable agreement with observations, with standard error of simulation on water content ranging between 0.007 and 0.011 cm3 cm−3, showing improved accuracy over other models that assume equilibrium ice‐water interfaces. Simulation results suggest that when the freezing front is fixed at a specific depth, deviation of the ice‐water interface from equilibrium, at this location, will increase with time. However, this deviation tends to weaken when the freezing front slowly penetrates to a greater depth, accompanied with thinner soils of significant deviation. The coefficient, β, plays an important role in the simulation of heat and water transport. A smaller β results in a larger deviation in the ice‐water interface from equilibrium, and backward estimation of the freezing front. It also leads to an underestimation of water content in soils that were previously frozen by a rapid freezing rate, and an overestimation of water content in the rest of the soils.
Distinct Short‐Range Order Is Inherent to Small Amorphous Calcium Carbonate Clusters (<2 nm)
Authors: Sun Shengtong , Chevrier Daniel M. , Zhang Peng , Gebauer Denis , Cölfen Helmut 
Published: September 2016

AbstractAmorphous intermediate phases are vital precursors in the crystallization of many biogenic minerals. While inherent short‐range orders have been found in amorphous calcium carbonates (ACCs) relating to different crystalline forms, it has never been clarified experimentally whether such orders already exist in very small clusters less than 2 nm in size. Here, we studied the stability and structure of 10,12‐pentacosadiynoic acid (PCDA) protected ACC clusters with a core size of ca. 1.4 nm consisting of only seven CaCO3 units. Ligand concentration and structure are shown to be key factors in stabilizing the ACC clusters. More importantly, even in such small CaCO3 entities, a proto‐calcite short‐range order can be identified but with a relatively high degree of disorder that arises from the very small size of the CaCO3 core. Our findings support the notion of a structural link between prenucleation clusters, amorphous intermediates, and final crystalline polymorphs, which appears central to the understanding of polymorph selection.
Modification of σ‐Donor Properties of Terminal Carbide Ligands Investigated Through Carbide–Iodine Adduct Formation
Authors: Reinholdt Anders , Vosch Tom , Bendix Jesper 
Published: September 2016

AbstractThe terminal carbide ligands in [(Cy3P)2X2Ru≡C] complexes (X=halide or pseudohalide) coordinate molecular iodine, affording charge‐transfer complexes rather than oxidation products. Crystallographic and vibrational spectroscopic data show the perturbations of iodine to vary with the auxiliary ligand sphere on ruthenium, demonstrating the σ‐donor properties of carbide complexes to be tunable.
Two‐Dimensional Crowding Uncovers a Hidden Conformation of α‐Synuclein
Authors: Banerjee Priya R. , Moosa Mahdi Muhammad , Deniz Ashok A. 
Published: September 2016

AbstractThe intrinsically disordered protein (IDP), α‐synuclein (αS), is well‐known for phospholipid membrane binding‐coupled folding into tunable helical conformers. Here, using single‐molecule experiments in conjunction with ensemble assays and a theoretical model, we present a unique case demonstrating that the interaction–folding landscape of αS can be tuned by two‐dimensional (2D) crowding through simultaneous binding of a second protein on the bilayer surface. Unexpectedly, the experimental data show a clear deviation from a simple competitive inhibition model, but are consistent with a bimodal inhibition mechanism wherein membrane binding of a second protein (a membrane interacting chaperone, Hsp27, in this case) differentially inhibits two distinct modules of αS–membrane interaction. As a consequence, αS molecules are forced to access a hidden conformational state on the phospholipid bilayer in which only the higher‐affinity module remains membrane‐bound. Our results demonstrate that macromolecular crowding in two dimensions can play a significant role in shaping the conformational landscape of membrane‐binding IDPs with multiple binding modes.
Copper‐Catalyzed Oxidation of Alkanes with H2O2 under a Fenton‐like Regime
Authors: Garcia‐Bosch Isaac , Siegler Maxime A. 
Published: September 2016

AbstractCopper complexes bearing readily available ligand systems catalyzed the oxidation of alkanes with H2O2 as the oxidant with high efficiency in remarkable yields (50–60 %). The reactions proceeded with unprecedented selectivity to give alkyl hydroperoxides as the major products. Detailed scrutiny of the reaction mechanism suggests the involvement of C‐centered and O‐centered radicals generated in a Fenton‐like fashion.
Robust Output Feedback Controller Design for Time‐Delayed Teleoperation: Experimental Results
Authors: Sharifi I. , Talebi H. A. , Motaharifar M. 
Published: September 2016

AbstractIn this paper, a robust output feedback control strategy is proposed for a nonlinear teleoperation system which can deal with stability as well as transparency despite the variable time‐delay and uncertain dynamics. The proposed approach is composed of two steps. First, local Lyapunov based adaptive controllers are applied to both master and slave sides in order to suppress the nonlinearities in the system dynamics. Afterwards, a new observer‐based controller scheme is proposed to achieve stability and performance (transparency) of the teleoperation system. Using the Lyapunov techniques, stability and performance objectives are cast as some linear matrix inequality (LMI) feasibility conditions. To evaluate the performance of the proposed controller, a set of simulations and experiments are performed. Through simulation results, it is demonstrated that the proposed approach significantly outperforms the existing methodologies reported in the literature.
Effects of FOXJ2 on TGF‐β1‐induced epithelial–mesenchymal transition through Notch signaling pathway in non‐small lung cancer
Authors: Yang Qichang , Cao Xingjian , Tao Guohua , Zhou Feng , Zhao Ping , Shen Yi , Chen Xiang 
Published: September 2016

AbstractAs one member of Forkhead box transcription factors, Forkhead box J2 (FOXJ2) has been found to be involved in epithelial–mesenchymal transition (EMT) process. However, the role and mechanism of FOXJ2 in non‐small cell lung cancer (NSCLC) and EMT regulation have not been fully revealed. In this paper, it was revealed that the expression of FOXJ2 was lower in NSCLC samples compared with matched peritumoral lung tissue. We demonstrated that FOXJ2 expression was down‐regulated by transforming growth factor‐β1 (TGF‐β1) treated, and overexpression of FOXJ2 inhibited TGF‐β1‐induced EMT. Mechanistically, knocking out the expression of FOXJ2 promoted EMT by increasing the expression of Notch1 and NICD. This study implicates the potential value of FOXJ2 as a molecular marker for NSCLC.