bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidences for a large hot spot on the disk of Betelgeuse (α Ori)
Authors: Montargès M. , Kervella P. , Perrin G. , Chiavassa A. , Le Bouquin J. B.
Published: January 2015

Massive evolved stars contribute to the chemical enrichment of the Galaxy. When they die as supernova but also through their mass loss during the several thousands of years of their red supergiant (RSG) phase. Unfortunately the mass loss mechanism remains poorly understood. Detailed study of the CSE and photosphere of nearby RSGs is required to constrain this scenario.

Betelgeuse is the closest RSG (197 pc) and therefore has a large apparent diameter (~ 42 mas) which makes it a very interesting target. For several years, our team has lead a multi-wavelength and multi-scale observing program to characterize its mass loss. We will review here our recent results in near-infrared interferometry.
Angular Diameters of O- and B-type Stars
Authors: Gordon Kathryn , Gies Douglas , Schaefer Gail
Published: January 2015

We are observing a sample of 10 O-type stars and 60 B-type stars to determine angular diameters using the Center for High Angular Resolution Astronomy (CHARA) Array, the foremost optical long baseline interferometer in the world. Our goal is to establish accurate stellar parameters to test modern theories of stellar evolution that include rotation. We will combine our stellar angular diameter measurements with flux and line measurements from spectroscopy, projected rotational velocities, and distances to determine radius, effective temperature, luminosity, equatorial rotational velocity, and evolutionary mass. Knowing these properties will allow us to place the stars in a Hertzsprung-Russell diagram and obtain estimates for the age and evolutionary state.
Binarity of the LBV HR Car
Authors: Rivinius Th. , Boffin H. M. J. , de Wit W. J. , Mehner A. , Martayan Ch. , Guieu S. , Le Bouquin J.-B.
Published: January 2015

VLTI/AMBER and VLTI/PIONIER observations of the LBV HR Car show an interferometric signature that could not possibly be explained by an extended wind, more or less symmetrically distributed around a single object. Instead, observations both in the Brγ line and the H-band continuum are best explained by two point sources (or alternatively one point source and one slightly extended source) at about 2 mas separation and a contrast ratio of about 1:5. These observations establish that HR Car is a binary, but further interpretation will only be possible with future observations to constrain the orbit. Under the assumption that the current separation is close to the maximum one, the orbital period can be estimated to be of the order of 5 years, similar as in the η Car system. This would make HR Car the second such LBV binary.
AMBER/VLTI Snapshot Survey on Circumstellar Environments
Authors: Rivinius Th. , de Wit W.J. , Demers Z. , Quirrenbach A. ,   the VLTI Science Operations Team
Published: January 2015

OHANA is an interferometric snapshot survey of the gaseous circumstellar environments of hot stars, carried out by the VLTI group at the Paranal observatory. It aims to characterize the mass-loss dynamics (winds/disks) at unexplored spatial scales for many stars. The survey employs the unique combination of AMBER's high spectral resolution with the unmatched spatial resolution provided by the VLTI. Because of the spatially unresolved central OBA-type star, with roughly neutral colour terms, their gaseous environments are among the easiest objects to be observed with AMBER, yet the extent and kinematics of the line emission regions are of high astrophysical interest.
Basics of spectropolarimetry
Authors: Landstreet John D.
Published: January 2015

Many astronomical sources of radiation emit polarised radiation, for example because of the presence of a disk which produces linear polarisation by scattering some photospheric radiation, or because of the presence of a magnetic field, which leads to circular and sometimes linear polarisation of spectral line profiles. Measuring the wavelength dependence of the polarisation of radiation from such sources can reveal valuable and interesting constraints on the nature of the objects observed. This paper summarises the basic ideas of spectropolarimetry and describes some of the information it can provide.
Magnetic Field - Stellar Winds Interaction
Authors: ud-Doula Asif
Published: January 2015

As per the recent study by the MiMeS collaboration, only about 10% of massive stars possess organized global magnetic fields, typically dipolar in nature. The competition between such magnetic fields and highly non-linear radiative forces that drive the stellar winds leads to a highly complex interaction. Such an interplay can lead to a number of observable phenomena, e.g. X-ray, wind confinement, rapid stellar spindown. However, due to its complexity, such an interaction cannot usually be modeled analytically, instead numerical modeling becomes a necessary tool. In this talk, I will discuss how numerical magnetohydrodynamic (MHD) simulations are employed to understand the nature of such magnetized massive star winds.
Beam me up, Spotty: Toward a new understanding of the physics of massive star photospheres
Authors: David-Uraz Alexandre , Wade Gregg , Owocki Stan
Published: January 2015

For 30 years, cyclical wind variability in OB stars has puzzled the astronomical community. Phenomenological models involving co-rotating bright spots provide a potential explanation for the observed variations, but the underlying physics remains unknown. We present recent results from hydrodynamical simulations constraining bright spot properties and compare them to what can be inferred from space-based photometry. We also explore the possibility that these spots are caused by magnetic fields and discuss the detectability of such fields.
Linear Polarization and the Dynamics of Circumstellar Disks of Classical Be Stars
Authors: Halonen Robbie J. , Jones Carol E.
Published: January 2015

The intrinsic linearly polarized light arising from electron scattering of stellar radiation in a non-spherically symmetric distribution of gas is a characterizing feature of classical Be stars. The distinct polarimetric signature provides a mean for directly probing the physical and geometric properties of the gaseous material enveloping these rapidly-rotating massive stars. Using a Monte Carlo radiative transfer computation and a self-consistent radiative equilibrium solution for the circumstellar gas, we explore the role of this observable signature in investigating the dynamical nature of classical Be star disks. In particular, we focus on the potential for using linearly polarized light to develop diagnostics of mass-loss events and to trace the evolution of the gas in a circumstellar disk. An informed context for interpreting the observed linear polarization signature can play an important role in identifying the physical process(es) which govern the formation and dissipation of the gaseous disks surrounding classical Be stars.
Project VeSElkA : Preliminary results for CP stars recently observed with ESPaDOnS
Authors: Khalack Viktor , LeBlanc Francis
Published: January 2015

We present the first results for the estimation of gravity and effective temperature of poorly studied chemically peculiar stars recently observed with the spectropolarimeter ESPaDOnS at CFHT in the frame of the VeSElkA (Vertical Stratification of Elements Abundance) project. A grid of theoretical stellar atmosphere models with the corresponding fluxes has been calculated using the PHOENIX code. We have used these fluxes to fit Balmer line profiles employing the code FITSB2 that produces estimates of the effective temperature, surface gravity and radial velocity for each star.
ξ1CMa: An Extremely Slowly Rotating Magnetic B0.7 IV Star
Authors: Shultz Matt , Wade Gregg , Rivinius Thomas , Marcolino Wagner , Henrichs Huib , Grunhut Jason ,   the MiMeS Collaboration
Published: January 2015

We present our analysis of 6 years of ESPaDOnS spectropolarimetry of the magnetic β Cep star ξ1CMa (B1 III). This high-precision magnetometry is consistent with a rotational periodProt> 40 yr. Absorption line profiles can be reproduced with a non-rotating model. We constrainR⋆,L⋆, and the stellar age via a Baade-Wesselink analysis. Spindown due to angular momentum loss via the magnetosphere predicts an extremely long rotational period if the magnetic dipoleBd> 6 kG, a strength also inferred by the best-fit sinusoids to the longitudinal magnetic field measurementsBZwhen phased with a 60-yearProt.
Magnetic fields and internal mixing of main sequence B stars
Authors: Wade G. A. , Folsom C. P. , Grunhut J. , Landstreet J. D. , Petit V.
Published: January 2015

We have obtained high-quality magnetic field measurements of 19 sharp-lined B-type stars with precisely-measured N/C abundance ratios (Nieva & Przybilla 2012). Our primary goal is to test the idea (Meynetet al. 2011) that a magnetic field may explain extra drag (through the wind) on the surface rotation, thus producing more internal shear and mixing, and thus could provide an explanation for the appearance of slowly rotating N-rich main sequence B stars.
The X-ray properties of magnetic massive stars
Authors: Nazé Yaël , Petit Véronique , Rinbrand Melanie , Cohen David , Owocki Stan , ud-Doula Asif , Wade Gregg
Published: January 2015

Early-type stars are well-known to be sources of soft X-rays. However, this high-energy emission can be supplemented by bright and hard X-rays when magnetically confined winds are present. In an attempt to clarify the systematics of the observed X-ray properties of this phenomenon, a large series of Chandra and XMM observations was analyzed, over 100 exposures of 60% of the known magnetic massive stars listed recently by Petit et al. (2013). It is found that the X-ray luminosity is strongly correlated with mass-loss rate, in agreement with predictions of magnetically confined wind models, though the predictions of higher temperature are not always verified. We also investigated the behaviour of other X-ray properties (absorption, variability), yielding additional constraints on models. This work not only advances our knowledge of the X-ray emission of massive stars, but also suggests new observational and theoretical avenues to further explore magnetically confined winds.
Abundance study of two magnetic B-type stars in the Orion Nebula Cluster
Authors: Morel T.
Published: January 2015

We present the results of an abundance analysis of two magnetic B-type stars in the Orion Nebula Cluster that support the lack of a direct relationship between the existence of a magnetic field and a nitrogen excess in the photosphere.
Chemotaxis by natural populations of coral reef bacteria
Authors: Tout Jessica , Jeffries Thomas C , Petrou Katherina , Tyson Gene W , Webster Nicole S , Garren Melissa , Stocker Roman , Ralph Peter J , Seymour Justin R
Published: January 2015

Corals experience intimate associations with distinct populations of marine microorganisms, but the microbial behaviours underpinning these relationships are poorly understood. There is evidence that chemotaxis is pivotal to the infection process of corals by pathogenic bacteria, but this evidence is limited to experiments using cultured isolates under laboratory conditions. We measured the chemotactic capabilities of natural populations of coral-associated bacteria towards chemicals released by corals and their symbionts, including amino acids, carbohydrates, ammonium and dimethylsulfoniopropionate (DMSP). Laboratory experiments, using a modified capillary assay, and in situ measurements, using a novel microfabricated in situ chemotaxis assay, were employed to quantify the chemotactic responses of natural microbial assemblages on the Great Barrier Reef. Both approaches showed that bacteria associated with the surface of the coral species Pocillopora damicornis and Acropora aspera exhibited significant levels of chemotaxis, particularly towards DMSP and amino acids, and that these levels of chemotaxis were significantly higher than that of bacteria inhabiting nearby, non-coral-associated waters. This pattern was supported by a significantly higher abundance of chemotaxis and motility genes in metagenomes within coral-associated water types. The phylogenetic composition of the coral-associated chemotactic microorganisms, determined using 16S rRNA amplicon pyrosequencing, differed from the community in the seawater surrounding the coral and comprised known coral associates, including potentially pathogenic Vibrio species. These findings indicate that motility and chemotaxis are prevalent phenotypes among coral-associated bacteria, and we propose that chemotaxis has an important role in the establishment and maintenance of specific coral–microbe associations, which may ultimately influence the health and stability of the coral holobiont.
Fumarate induces redox-dependent senescence by modifying glutathione metabolism
Authors: Zheng Liang , Cardaci Simone , Jerby Livnat , MacKenzie Elaine D. , Sciacovelli Marco , Johnson T. Isaac , Gaude Edoardo , King Ayala , Leach Joshua D. G. , Edrada-Ebel RuAngelie , Hedley Ann , Morrice Nicholas A. , Kalna Gabriela , Blyth Karen , Ruppin Eytan , Frezza Christian , Gottlieb Eyal
Published: January 2015

Mutations in the tricarboxylic acid (TCA) cycle enzyme fumarate hydratase (FH) are associated with a highly malignant form of renal cancer. We combined analytical chemistry and metabolic computational modelling to investigate the metabolic implications of FH loss in immortalized and primary mouse kidney cells. Here, we show that the accumulation of fumarate caused by the inactivation of FH leads to oxidative stress that is mediated by the formation of succinicGSH, a covalent adduct between fumarate and glutathione. Chronic succination of GSH, caused by the loss of FH, or by exogenous fumarate, leads to persistent oxidative stress and cellular senescence in vitro and in vivo. Importantly, the ablation of p21, a key mediator of senescence, in Fh1-deficient mice resulted in the transformation of benign renal cysts into a hyperplastic lesion, suggesting that fumarate-induced senescence needs to be bypassed for the initiation of renal cancers.
Gene therapy restores vision in rd1 mice after removal of a confounding mutation in Gpr179
Authors: Nishiguchi Koji M. , Carvalho Livia S. , Rizzi Matteo , Powell Kate , Holthaus Sophia-Martha kleine , Azam Selina A. , Duran Yanai , Ribeiro Joana , Luhmann Ulrich F. O. , Bainbridge James W. B. , Smith Alexander J. , Ali Robin R.
Published: January 2015

The rd1 mouse with a mutation in the Pde6b gene was the first strain of mice identified with a retinal degeneration. However, AAV-mediated gene supplementation of rd1 mice only results in structural preservation of photoreceptors, and restoration of the photoreceptor-mediated a-wave, but not in restoration of the bipolar cell-mediated b-wave. Here we show that a mutation in Gpr179 prevents the full restoration of vision in rd1 mice. Backcrossing rd1 with C57BL6 mice reveals the complete lack of b-wave in a subset of mice, consistent with an autosomal recessive Mendelian inheritance pattern. We identify a mutation in the Gpr179 gene, which encodes for a G-protein coupled receptor localized to the dendrites of ON-bipolar cells. Gene replacement in rd1 mice that are devoid of the mutation in Gpr179 successfully restores the function of both photoreceptors and bipolar cells, which is maintained for up to 13 months. Our discovery may explain the failure of previous gene therapy attempts in rd1 mice, and we propose that Grp179 mutation status should be taken into account in future studies involving rd1 mice.
A number-form area in the blind
Authors: Abboud Sami , Maidenbaum Shachar , Dehaene Stanislas , Amedi Amir
Published: January 2015

Distinct preference for visual number symbols was recently discovered in the human right inferior temporal gyrus (rITG). It remains unclear how this preference emerges, what is the contribution of shape biases to its formation and whether visual processing underlies it. Here we use congenital blindness as a model for brain development without visual experience. During fMRI, we present blind subjects with shapes encoded using a novel visual-to-music sensory-substitution device (The EyeMusic). Greater activation is observed in the rITG when subjects process symbols as numbers compared with control tasks on the same symbols. Using resting-state fMRI in the blind and sighted, we further show that the areas with preference for numerals and letters exhibit distinct patterns of functional connectivity with quantity and language-processing areas, respectively. Our findings suggest that specificity in the ventral ‘visual’ stream can emerge independently of sensory modality and visual experience, under the influence of distinct connectivity patterns.
Quantum Clock Synchronization with a Single Qudit
Authors: Tavakoli Armin , Cabello Adán , Żukowski Marek , Bourennane Mohamed
Published: January 2015

Clock synchronization for nonfaulty processes in multiprocess networks is indispensable for a variety of technologies. A reliable system must be able to resynchronize the nonfaulty processes upon some components failing causing the distribution of incorrect or conflicting information in the network. The task of synchronizing such networks is related to Byzantine agreement (BA), which can classically be solved using recursive algorithms if and only if less than one-third of the processes are faulty. Here we introduce a nonrecursive quantum algorithm, based on a quantum solution of the detectable BA, which achieves clock synchronization in the presence of arbitrary many faulty processes by using only a single quantum system.
Insolation driven biomagnetic response to the Holocene Warm Period in semi-arid East Asia
Authors: Liu Suzhen , Deng Chenglong , Xiao Jule , Li Jinhua , Paterson Greig A. , Chang Liao , Yi Liang , Qin Huafeng , Pan Yongxin , Zhu Rixiang
Published: January 2015

The Holocene Warm Period (HWP) provides valuable insights into the climate system and biotic responses to environmental variability and thus serves as an excellent analogue for future global climate changes. Here we document, for the first time, that warm and wet HWP conditions were highly favourable for magnetofossil proliferation in the semi-arid Asian interior. The pronounced increase of magnetofossil concentrations at ~9.8 ka and decrease at ~5.9 ka in Dali Lake coincided respectively with the onset and termination of the HWP and are respectively linked to increased nutrient supply due to postglacial warming and poor nutrition due to drying at ~6 ka in the Asian interior. The two-stage transition at ~7.7 ka correlates well with increased organic carbon in middle HWP and suggests that improved climate conditions, leading to high quality nutrient influx, fostered magnetofossil proliferation. Our findings represent an excellent lake record in which magnetofossil abundance is, through nutrient availability, controlled by insolation driven climate changes.
Single wall carbon nanotubes-oxide test strip for one-step solid phase extraction of simetryn and fast detection using surface enhanced Raman spectroscopy
Authors: Deng Zhuo , Liu Haihong , Wang Yiru , Chen Xi
Published: January 2015

A facile method was established for the preparation of a SWCNTs-oxide test strip to act as a one-step SPE adsorbent and SERS substrate, which can be used as a rapid monitor for triazine residues in lake water by combing solid-phase extraction and surface-enhanced Raman spectroscopy.
Improved monitoring of P. aeruginosa on agar plates
Authors: Webster T. A. , Sismaet H. J. , Sattler A. F. , Goluch E. D.
Published: January 2015

A disposable electrochemical assay that is integrated with standard culture plates for the selective and specific detection of Pseudomonas aeruginosa.
β-(1-Azulenyl)-l-alanine – a functional probe for determination of pKa of histidine residues
Authors: Gosavi Pallavi M. , Moroz Yurii S. , Korendovych Ivan V.
Published: January 2015

Substitution of tryptophan with β-(1-azulenyl)-l-alanine allows for direct and straightforward determination of pKa values of histidines without perturbing protein function.
Low band gap benzothiophene–thienothiophene copolymers with conjugated alkylthiothieyl and alkoxycarbonyl cyanovinyl side chains for photovoltaic applications
Authors: Feng Kui , Xu Xiaopeng , Li Zuojia , Li Ying , Li Kai , Yu Ting , Peng Qiang
Published: January 2015

Alkylthiothieyl substituted benzothiophene (BDT) and alkoxycarbonyl cyanovinyl modified thienothiophene (TT) were copolymerized to obtain a new low band gap copolymer PBDTTT-S-CN with a efficiency of 7.00%.
Promoting the “water-wire” mechanism of double proton transfer in [2,2′-bipyridyl]-3,3′-diol by porous gold nanoparticles
Authors: Nag Tarak Nath , Das Tarasankar , Mondal Somen , Maity Arnab , Purkayastha Pradipta
Published: January 2015

The “water-wire” mechanism of double proton transfer in [2,2′-bipyridyl]-3,3′-diol (BP(OH)2) is promoted in nanopores on gold nanoparticles.
Large protonation-gated photochromism of an OPE-embedded difurylperfluorocyclopentene
Authors: Wolf Jannic , Huhn Thomas , Steiner Ulrich E.
Published: January 2015

Double protonation (red) increases the ring-closing quantum yield Q⃑ of a molecular switch more than tenfold.
Nonlinear optical imaging of single plasmonic nanoparticles with 30 nm resolution
Authors: Horneber Anke , Braun Kai , Rogalski Jan , Leiderer Paul , Meixner Alfred J. , Zhang Dai
Published: January 2015

Femtosecond-scanning near-field optical microscopy resolves the location-correlated second harmonic generation and two-photon photoluminescence from single nanoparticles with 30 nm resolution.
Hierarchical graphene@Fe3O4 nanocluster@carbon@MnO2 nanosheet array composites: synthesis and microwave absorption performance
Authors: Wang Lei , Huang Ying , Li Chao , Chen Junjiao , Sun Xu
Published: January 2015

The fabrication of novel hierarchical graphene@Fe3O4 nanocluster@carbon@MnO2 nanosheet array composites has been successfully carried out for the first time.
Correlating structure with non-linear optical properties in xAs40Se60·(1 − x)As40S60glasses
Authors: Barney Emma R. , Abdel-Moneim Nabil S. , Towey James J. , Titman Jeremy , McCarthy John E. , Bookey Henry T. , Kar Ajoy , Furniss David , Seddon Angela B.
Published: January 2015

A series ofxAs40Se60·(100 −x)As40S60glasses, wherex= 0, 25, 33, 50, 67, 75 and 100 mol% As40Se60, has been studied using neutron and X-ray total scattering, Raman spectroscopy and77Se MAS-NMR.
Hydrogen generation by the reaction of H2O with Al2O3-based materials: a computational analysis
Authors: Lu Yu-Huan , Chen Hsin-Tsung
Published: January 2015

By combined DFT and first-principles MD simulation, we propose detailed reaction mechanisms for H2O splitting and hydrogen generation on Al2O3-based materials.
Pressure-induced oversaturation and phase transition in zeolitic imidazolate frameworks with remarkable mechanical stability
Authors: Zhao Pu , Bennett Thomas D. , Casati Nicola P. M. , Lampronti Giulio I. , Moggach Stephen A. , Redfern Simon A. T.
Published: January 2015

ZIF-7/9 are shown be able to withstand high hydrostatic pressure unaffected by metal substitution, whilst retaining porosity and structural integrity.
Oxidation behavior of zero-valent iron nanoparticles in mixed matrix water purification membranes
Authors: Torrey Jessica D. , Killgore Jason P. , Bedford Nicholas M. , Greenlee Lauren F.
Published: January 2015

AFM measurements show mechanical decay of ZVI nanoparticles, but the force is much higher than that found in membranes.
Glycerol acetals and ketals as bio-based solvents: positioning in Hansen and COSMO-RS spaces, volatility and stability towards hydrolysis and autoxidation
Authors: Moity Laurianne , Benazzouz Adrien , Molinier Valérie , Nardello-Rataj Véronique , Elmkaddem Mohammed Kamal , de Caro Pascale , Thiébaud-Roux Sophie , Gerbaud Vincent , Marion Philippe , Aubry Jean-Marie
Published: January 2015

Hansen and COSMO-RS approaches show that glycerol ketals and acetals can be effective alternatives to certain harmful petro-sourced solvents.
Deep eutectic solvents as highly active catalysts for the fast and mild glycolysis of poly(ethylene terephthalate)(PET)
Authors: Wang Qian , Yao Xiaoqian , Geng Yanrong , Zhou Qing , Lu Xingmei , Zhang Suojiang
Published: January 2015

Urea/metal salt DESs can catalyze PET degradation into a monomer with high selectivity in a short time under mild conditions.
Early markers of Fabry disease revealed by proteomics
Authors: Matafora V. , Cuccurullo M. , Beneduci A. , Petrazzuolo O. , Simeone A. , Anastasio P. , Mignani R. , Feriozzi S. , Pisani A. , Comotti C. , Bachi A. , Capasso G.
Published: January 2015

Discovery of early urinary biomarkers for Fabry disease in male and female adult patients revealed by proteomics.
The design of phenylboronic acid azoprobe–polyamidoamine dendrimer complexes as supramolecular sensors for saccharide recognition in water
Authors: Tsuchido Yuji , Sakai Yuuki , Aimu Keisuke , Hashimoto Takeshi , Akiyoshi Kazunari , Hayashita Takashi
Published: January 2015

Phenylboronic acid azoprobe–PAMAM dendrimer complex responded to saccharides and exhibited selective aggregation particularly with glucose at neutral pH.
Efficient synthesis of some new antiproliferative N-fused indoles and isoquinolines via 1,3-dipolar cycloaddition reaction in an ionic liquid
Authors: Sutariya Tushar R. , Labana Balvantsingh M. , Parmar Narsidas J. , Kant Rajni , Gupta Vivek K. , Plata Gabriela B. , Padrón José M.
Published: January 2015

Triethylammonium acetate (TEAA) as a new, recyclable and environmentally friendly reaction medium for the intramolecular[3+2] cycloaddition reaction.
Graphene nanomesh photodetector with effective charge tunnelling from quantum dots
Authors: Liu Xiang , Liu Nianze , Liu Mingju , Tao Zhi , Kuang Wenjian , Ji Xiangbing , Chen Jing , Lei Wei , Dai Qing , Li Chi , Li Xuehua , Nathan Arokia
Published: January 2015

A high-performance photodetector is fabricated with high responsivity, high on/off ratio and short response time with the merits of GNM and QDs.
Metallic-nanowire-loaded silicon-on-insulator structures: a route to low-loss plasmon waveguiding on the nanoscale
Authors: Bian Yusheng , Gong Qihuang
Published: January 2015

Metallic nanowires on top of silica-covered silicon-on-insulator substrates enable the realization of high-performance light transport on the nanoscale.
Size dependent effect of new organometallic triptycene tectons on the dimensions of self-assembled macrocycles
Authors: Chakraborty Sourav , Bhowmick Sourav , Ma Jianqiu , Tan Hongwei , Das Neeladri
Published: January 2015

The effect of changing the dimension of triptycene-based acceptor building blocks on the shape and size of the resulting supramolecular framework is reported.
UV-patternable nanocomposite containing CdSe and PbS quantum dots as miniaturized luminescent chemo-sensors
Authors: Rodríguez-Cantó Pedro J. , Abargues Rafael , Gordillo Henry , Suárez Isaac , Chirvony Vladimir , Albert Sandra , Martínez-Pastor Juan
Published: January 2015

We have developed a patternable nanocomposite sensor based on luminescent CdSe QDs and a polyisoprene-based photoresist (PIP) as host matrix that showed chemosensing response against MET and EDA in vapour with a LOD around 0.1 pg and 15 ng, respectively.
Enzymatically degradable EMI shielding materials derived from PCL based nanocomposites
Authors: Pawar Shital Patangrao , Kumar Sachin , Misra Anupam , Deshmukh Subrajeet , Chatterjee Kaushik , Bose Suryasarathi
Published: January 2015

Bio-degradable nanocomposites with enhanced microwave attenuation ability were designed from PCL and MWNTs.
Hydrogen-assisted catalytic ignition characteristics of propane–air with a chemical kinetic model in a Pt/γ-Al2O3micro-combustor in different feeding modes
Authors: Chen Junjie , Yan Longfei , Song Wenya
Published: January 2015

From ambient cold-start conditions, the hydrogen self-ignition and hydrogen-assisted ignition of propane–air mixtures with chemical kinetic model in different feeding modes were numerically investigated in Pt/γ-Al2O3catalytic micro-combustors.
Synthesis and characterization of a Sr0.95Y0.05TiO3−δ-based hydrogen electrode for reversible solid oxide cells
Authors: Ling Yihan , Chen Luyang , Lin Bin , Yu Weili , Isimjan Tayirjan T. , Zhao Ling , Liu Xingqin
Published: January 2015

Reversible solid oxide cells (RSOCs) can generate electricity as solid oxide fuel cells (SOFC) facing a shortage of electricity and can also store the electricity as solid oxide electrolysis cells (SOEC) at the time of excessive electricity.
Reduction kinetics of hematite to magnetite under hydrothermal treatments
Authors: Lu J. F. , Tsai C. J.
Published: January 2015

The phase transformation of α-Fe2O3 to Fe3O4 was observed by the hydrothermal treatment of a ferric solution at 160–220 °C with the addition of both KOH and EDA into the reaction system.
Analysis of pathogenic bacteria using exogenous volatile organic compound metabolites and optical sensor detection
Authors: Tait Emma , Stanforth Stephen P. , Reed Stephen , Perry John D. , Dean John R.
Published: January 2015

A novel, low-cost and simple method for the detection of pathogenic bacteria is proposed.
A non-template approach to fabricate mesoporous alumina with predefined morphology by solid-state transformation of Al-based metal–organic frameworks
Authors: Liu Dandan , Dai Fangna , Li Xuehui , Liang Jilei , Liu Yunqi , Liu Chenguang
Published: January 2015

Using different Al-MOFs as precursor, mesoporous γ-Al2O3 with special morphology and different textural properties were synthesized by thermal treatment method.
The KNIME based classification models for yellow fever virus inhibition
Authors: Narayana Moorthy N. S. Hari , Poongavanam Vasanthanathan
Published: January 2015

The Naïve Bayes method as implemented in KNIME platform for classification of YFV inhibition. The best classification model is able to correctly discriminate >90% of inhibitors and non-inhibitors.
Pyrrole: a resourceful small molecule in key medicinal hetero-aromatics
Authors: Bhardwaj Varun , Gumber Divya , Abbot Vikrant , Dhiman Saurabh , Sharma Poonam
Published: January 2015

Pyrrole is widely known as a biologically active scaffold which possesses a diverse nature of activities.
The impact of the HPMA polymer structure on the targeting performance of the conjugated hydrophobic ligand
Authors: Yang Qingqing , Li Lian , Zhu Xi , Sun Wei , Zhou Zhou , Huang Yuan
Published: January 2015

The structure of hydrophilic polymer plays a vital role in the targeting efficiency of the conjugated hydrophobic ligand.
Establishment of a controlled insulin delivery system using a glucose-responsive double-layered nanogel
Authors: Lee DaeYong , Choe Kibaek , Jeong YongJun , Yoo Jisang , Lee Sung Mun , Park Ji-Ho , Kim Pilhan , Kim Yeu-Chun
Published: January 2015

Glucose-responsive glycol chitosan/sodium alginate-poly(l-glutmate-co-N-3-l-glutamylphenylboronic acid) double-layered nanogel is a promising platform for controlled insulin release systems, achieving glucose-triggered insulin release at diabetic glucose levels in vivo.
A far-red emitting probe for unambiguous detection of mobile zinc in acidic vesicles and deep tissue
Authors: Rivera-Fuentes Pablo , Wrobel Alexandra T. , Zastrow Melissa L. , Khan Mustafa , Georgiou John , Luyben Thomas T. , Roder John C. , Okamoto Kenichi , Lippard Stephen J.
Published: January 2015

A fluorescent sensor that is pH-insensitive and compatible with two-photon microscopy was developed and applied to live cell and deep tissue imaging.
Facile synthesis of Z-scheme Ag2CO3/Ag/AgBr ternary heterostructured nanorods with improved photostability and photoactivity
Authors: Li Jingjing , Xie Yunlong , Zhong Yijun , Hu Yong
Published: January 2015

We demonstrated a facile reaction route, visible-light induced reduction followed by an anion exchange, to prepare one-dimensional (1D) Z-scheme Ag2CO3/Ag/AgBr ternary heterostructured nanorods (HNRs) with tunable chemical compositions at room temperature. The as-obtained 1D Ag2CO3/Ag/AgBr HNRs exhibit significantly enhanced photostability and photocatalytic activity.
Self-sorting behavior of a four-component host–guest system and its incorporation into a linear supramolecular alternating copolymer
Authors: Zeng Fei , Han Ying , Chen Chuan-Feng
Published: January 2015

Self-sorting behavior of a four-component host–guest system was found, which could be utilized to construct a linear supramolecular alternating copolymer.
A pillar[5]arene-fused cryptand: from orthogonal self-assembly to supramolecular polymer
Authors: Wang Qi , Cheng Ming , Zhao Yue , Wu Lin , Jiang Juli , Wang Leyong , Pan Yi
Published: January 2015

A supramolecular polymer based on a novel pillar[5]arene-fused cryptand host was successfully constructed by the orthogonal self-assembly of two host–guest interactions.
Synthesis of [POCOP]-pincer iron and cobalt complexes via Csp3–H activation and catalytic application of iron hydride in hydrosilylation reactions
Authors: Huang Shaofeng , Zhao Hua , Li Xiaoyan , Wang Lin , Sun Hongjian
Published: January 2015

Csp3–H bond activation in pincer ligand (Ph2PO(o-C6H2-(4,6-tBu2)))2CH2 (1) (POCH2OP) was achieved by Fe(PMe3)4 and CoMe(PMe3)4 to afford (POCHOP)Fe(H) (PMe3)2 (2) and (POCHOP)Co(PMe3)2 (4).
Electrical properties and flux performance of composite ceramic hydrogen separation membranes
Authors: Fish J. S. , Ricote S. , O'Hayre R. , Bonanos N.
Published: January 2015

Dual-phase ceramic composite hydrogen separation membranes composed of STN and BCZY are fabricated by spark plasma sintering. The electrical properties and hydrogen flux performance are evaluated, revealing challenges for this unique composite material.
Dynamic Assessment of Morphological Awareness and Third-Grade Literacy Success
Authors: Wolter Julie A. , Pike Katherine
Published: January 2015

Purpose

The purpose of this study was to examine a dynamic assessment with graduated prompts to assess morphological awareness and determine whether such a task was related to third-grade literacy success.

Method

A dynamic assessment of morphological awareness was adapted and administered to 54 third-grade students in addition to a norm-referenced language and literacy battery.

Results

A dynamic assessment of morphological awareness measured a range of performance including that of emerging morphological awareness abilities and provided rich linguistic insights for how best to scaffold and prompt for such a skill. In addition, the dynamic morphological awareness measure was found to be significantly related to, and to contribute unique variance to, reading comprehension abilities.

Conclusions

These results suggest that morphological awareness is an important factor to consider when addressing students' literacy performance in early elementary school and that dynamic assessment appears to be a clinically valuable tool when examining early morphological awareness abilities.
Demosaicing using subband‐based classifiers
Authors: Sung Da‐Cheng , Tsao Hen‐Wai
Published: January 2015

A new wavelet‐based interpolation algorithm to improve the performance of colour filter array (CFA) interpolation is exploited. The purpose of a CFA is to filter a single colour in digital still camera images. A CFA interpolation can then restore full colour to images captured by the CFA. The proposed classifier can effectively restore edge information and reduce the complexity of computation.
Performance enhancement of fully transparent tin‐doped zinc oxide thin‐film transistors fabricated by sputtering at low temperature
Authors: Chen Zhuofa , Han Dedong , Zhao Nannan , Cong Yingying , Wu Jing , Dong Junchen , Zhao Feilong , Huang Lingling , Zhang Yi , Cui Guodong , Liu Lifeng , Zhang Shengdong , Zhang Xing , Wang Yi
Published: January 2015

Fully transparent tin‐doped zinc oxide thin‐film transistors (TZO TFTs) were successfully fabricated on glass substrate by radio‐frequency sputtering at room temperature. In this reported work, TZO is adopted as the channel layer, SiO2 as the gate insulator and indium tin oxide as gate and source/drain electrodes. The surface morphology and crystallographic structure of the TZO films were evaluated by scanning electron microscopy and X‐ray diffraction, respectively. Sn atoms are found to successfully replace Zn sites in the lattice and form stable Sn–O bonds. Sn dopants and adding O2 during the TZO channel deposition can enhance the device performance. The as‐fabricated TZO TFT exhibited excellent electrical and optical properties. Hence, TZO can be a promising candidate for the next generation driving active‐matrix flat panel displays.
Accelerating floating‐point to fixed‐point data type conversion with evolutionary algorithms
Authors: Rosa L.S. , Toledo C.F.M. , Bonato V.
Published: January 2015

The choice of the data type representation has significant impacts on the resource utilisation, maximum clock frequency and power consumption of any hardware design. Although arithmetic hardware units for the fixed‐point format can improve performance and reduce energy consumption, the process of tuning the right bit length is known as a time‐consuming task, since it is a combinatorial optimisation problem guided by the accumulative arithmetic computation error. A novel evolutionary approach to accelerate the process of converting algorithms from the floating‐point to fixed‐point format is presented. Results are demonstrated by converting three computing‐intensive algorithms from the mobile robotic scenario, where data error accumulated during execution is influenced by external factors, such as sensor noise and navigation environment characteristics. The proposed evolutionary algorithm accelerated the conversion process by up to 2.5 × against the state‐of‐the‐art methods, allowing even further bit‐length optimisations.
Frequency‐agile microstrip patch antenna on a biased liquid crystal substrate
Authors: Papanicolaou N.C. , Christou M.A. , Polycarpou A.C.
Published: January 2015

A frequency‐agile microstrip patch antenna printed on a biased nematic liquid crystal (N‐LC) substrate is accurately modelled. The dielectric properties of the N‐LC are controlled through the strength of the bias voltage. The model is based on the solution of Poisson's equation coupled to a nonlinear partial differential equation (PDE) describing the orientation of the directors in a non‐homogeneous electric field. The coupled problem was solved using an iterative finite difference (FD) scheme. The obtained numerical results are compared and verified against measurements already published in the literature.
Free class AB–AB Miller opamp with high current enhancement
Authors: Roman‐Loera Alejandro , Ramirez‐Angulo Jaime , Lopez‐Martin Antonio , Carvajal Ramon G.
Published: January 2015

A two‐stage (Miller) operational amplifier (opamp) with both class AB input and output stages is introduced. It has a well‐controlled quiescent current and generates dynamic output currents of up to a factor 45 times larger than the quiescent current. It uses very compact circuitry with small static power consumption in order to achieve class AB–AB operation and can operate with a low supply voltage. Experimental results of a test chip fabricated using 0.18 μm CMOS technology and simulations in 130, 90, 65 and 45 nm verify the proposed circuit.
Neuromorphic VLSI Bayesian integration synapse
Authors: Aggarwal A.
Published: January 2015

Bayesian integration is thought to be used by the brain for optimal decision‐making based on information from different sources. Recent evidence indicates that the hippocampal place cells use this mechanism to integrate information at the level of a single cell as opposed to that at the network level as postulated earlier. Therefore a synapse circuit is proposed, which can perform Bayesian integration on three inputs and present results from its implementation in silicon.
Ultraprecision XY stage using a hybrid bolt-clamped Langevin-type ultrasonic linear motor for continuous motion
Authors: Lee Dong-Jin , Lee Sun-Kyu
Published: January 2015

This paper presents a design and control system for an XY stage driven by an ultrasonic linear motor. In this study, a hybrid bolt-clamped Langevin-type ultrasonic linear motor was manufactured and then operated at the resonance frequency of the third longitudinal and the sixth lateral modes. These two modes were matched through the preload adjustment and precisely tuned by the frequency matching method based on the impedance matching method with consideration of the different moving weights. The XY stage was evaluated in terms of position and circular motion. To achieve both fine and stable motion, the controller consisted of a nominal characteristics trajectory following (NCTF) control for continuous motion, dead zone compensation, and a switching controller based on the different NCTFs for the macro- and micro-dynamics regimes. The experimental results showed that the developed stage enables positioning and continuous motion with nanometer-level accuracy.
Model for transport and reaction of defects and carriers within displacement cascades in gallium arsenide
Authors: Wampler William R. , Myers Samuel M.
Published: January 2015

A model is presented for recombination of charge carriers at evolving displacement damage in gallium arsenide, which includes clustering of the defects in atomic displacement cascades produced by neutron or ion irradiation. The carrier recombination model is based on an atomistic description of capture and emission of carriers by the defects with time evolution resulting from the migration and reaction of the defects. The physics and equations on which the model is based are presented, along with the details of the numerical methods used for their solution. The model uses a continuum description of diffusion, field-drift and reaction of carriers, and defects within a representative spherically symmetric cluster of defects. The initial radial defect profiles within the cluster were determined through pair-correlation-function analysis of the spatial distribution of defects obtained from the binary-collision code MARLOWE, using recoil energies for fission neutrons. Properties of the defects are discussed and values for their parameters are given, many of which were obtained from density functional theory. The model provides a basis for predicting the transient response of III-V heterojunction bipolar transistors to displacement damage from energetic particle irradiation.
Self-excited oscillations of two opposing planar air jets
Authors: Hassaballa M. , Ziada S.
Published: January 2015

This paper investigates the self-excited oscillations of two co-planar air jets impinging on each other, referred to, hereafter, by opposing planar jets. The study is performed for a single jet thickness of h = 2 mm and a span-wise aspect ratio of 50. The effects of flow velocity of the jets and the distance between them are examined. The opposing planar jets are found to produce strong acoustic tones over a wide range of jet Mach number and separation distance. Phase-locked averaged particle image velocity measurements showed that the tone is generated by out-of-phase flapping oscillations of the planar jets. These oscillations are sustained by two effects. The first is the high stagnation pressure at the impingement region, which deflects the jets laterally in opposite directions away from their common centerline, while the second effect is the cross stream oscillating velocity in the entrainment regions around the jet exits, which forces the jets back towards their common centerline.
Sensitivity of CoSi2 precipitation in silicon to extra-low dopant concentrations. II. First-principles calculations
Authors: Borodin V. A. , Ganchenkova M. G. , Ruault M.-O. , Fortuna F.
Published: January 2015

The paper is the second part of the study on the influence of very low dopant content in silicon on CoSi2 precipitation during high-temperature cobalt ion implantation into transmission electron microscope samples. It deals with the computational justification of various assumptions used in Paper I when rationalizing the kinetics of cobalt clustering in ion-implanted intrinsic silicon (both undoped and containing low concentrations of phosphorus atoms). In particular, it is proven that divacancies are efficient nucleation centers for the new Co-Si phase. It is shown that the capture of vacancies and divacancies on phosphorus atoms increases their lifetime in silicon matrix, but practically does not affect the mechanism of their interaction with interstitial cobalt atoms. Finally, it is demonstrated that the mobility of phosphorus interstitials at temperatures of our experiment is orders of magnitude higher than might be expected from the published literature data.
Conductance and spin-filter effects of oxygen-incorporated Au, Cu, and Fe single-atom chains
Authors: Zheng Xiaolong , Xie Yi-Qun , Ye Xiang , Ke San-Huang
Published: January 2015

We studied the spin-polarized electron transport in oxygen-incorporated Au, Cu, and Fe single-atom chains (SACs) by first-principles calculations. We first investigated the mechanism responsible for the low conductance (<1G0) of the Au and Cu SACs in an oxygen environment reported in recent experiments. We found that for the Au SACs, the low conductance plateau around 0.6G0 can be attributed to a distorted chain doped with a single oxygen atom, while the 0.1G0 conductance comes from a linear chain incorporated with an oxygen molecule and is caused by an antibonding state formed by oxygen's occupied frontier orbital with dz orbitals of adjacent Au atoms. For the Cu SACs, the conductance about 0.3G0 is ascribed to a special configuration that contains Cu and O atoms in an alternating sequence. This exhibits an even-odd conductance oscillation with an amplitude of ∼0.1G0. In contrast, for the alternating Fe-O SACs, conductance overall decreases with an increase in O atoms and it approaches nearly zero for the chain with more than four O atoms. While the Cu-O SACs behave as perfect spin filters for one spin channel due to the half metallic nature, the Fe-O SACs can serve as perfect spin filters for two spin channels depending on the polarity of the applied gate voltage.
Magnetotransport properties of spin-valve structures with Mg spacer layers
Authors: Martinez-Boubeta C. , Ferrante Y. , Parkin S. S. P.
Published: January 2015

A theoretical prediction by Wang et al. [Phys. Rev. B 82, 054405 (2010)] suggests the preferential transmission of majority-spin states with Δ1 symmetry across a magnesium interlayer in Fe/Mg/MgO/Fe based magnetic tunnel junctions. Here, we report experiments to probe this question in CoFe/Mg/CoFe structures. We find that the strength of the interlayer coupling decays exponentially with increasing the spacer thickness, however, a non-monotonic variation of the magnetoresistance as a function of the Mg layer is observed. These data may help revisit the role of the insertion of a Mg interface layer in MgO-based devices.
High mobility back-gated InAs/GaSb double quantum well grown on GaSb substrate
Authors: Nguyen Binh-Minh , Yi Wei , Noah Ramsey , Thorp Jacob , Sokolich Marko
Published: January 2015

We report a backgated InAs/GaSb double quantum well device grown on GaSb substrate. The use of the native substrate allows for high materials quality with electron mobility in excess of 500 000 cm2/Vs at sheet charge density of 8 × 1011 cm−2 and approaching 100 000 cm2/Vs near the charge neutrality point. Lattice matching between the quantum well structure and the substrate eliminates the need for a thick buffer, enabling large back gate capacitance and efficient coupling with the conduction channels in the quantum wells. As a result, quantum Hall effects are observed in both electron and hole regimes across the hybridization gap.