bluuebunny/crossref_metadata_2025 huggingface dataset:
A fluorescent metal–organic framework for highly selective detection of nitro explosives in the aqueous phase
Authors: Nagarkar Sanjog S. , Desai Aamod V. , Ghosh Sujit K.
Published: May 2014

Aqueous phase selective and sensitive nitro explosive detection by a porous luminescent metal–organic framework.
Encapsulation of manganese and cobalt complexes within resorcin[4]arene dimers
Authors: Drachnik Amanda M. , Kumari Harshita , Barnes Charles L. , Deakyne Carol A. , Atwood Jerry L.
Published: May 2014

Resorcin[4]arene capture of Mn2+ or Co2+ metals yields inclusion complexes 1, 2a and 2b.
Two-way effects of surfactants on Pickering emulsions stabilized by the self-assembled microcrystals of α-cyclodextrin and oil
Authors: Li Xue , Li Haiyan , Xiao Qun , Wang Liuyi , Wang Manli , Lu Xiaolong , York Peter , Shi Senlin , Zhang Jiwen
Published: May 2014

Two way effects of Tween 80 and soybean lecithin (PL) on the stability of cyclodextrin (CD) Pickering emulsions.
The nanocomposite of polyaniline and nitrogen-doped layered HTiNbO5with excellent visible-light photocatalytic performance
Authors: Liu Chao , Wu Liang , Chen Jing , Liang Ji-yuan , Li Chang-shun , Ji Hong-mei , Hou Wen-hua
Published: May 2014

N-doping and intercalation resulted in a PANI–N-HTiNbO5lamellar nanocomposite, which showed a dramatic enhanced visible-light photocatalytic activity and stability for the degradation of methylene blue (MB), due to the high efficiency of charge separation.
Exploiting level anti-crossings (LACs) in the rotating frame for transferring spin hyperpolarization
Authors: Pravdivtsev Andrey N. , Yurkovskaya Alexandra V. , Lukzen Nikita N. , Vieth Hans-Martin , Ivanov Konstantin L.
Published: May 2014

A method of transferring hyperpolarization among scalar-coupled nuclear spins is proposed, which is based on spin mixing at energy level anti-crossing (LAC) regions.
Electronic and structural study of Pt-modified Au vicinal surfaces: a model system for Pt–Au catalysts
Authors: Prieto Mauricio J. , Carbonio Emilia A. , Fatayer Shadi , Landers Richard , Siervo Abner de
Published: May 2014

Morphology and electronic properties of Pt nanostructures are influenced by the underlying Au surface orientation and surface alloy formation, respectively.
A Raman spectroscopic study of the carbon deposition mechanism on Ni/CGO electrodes during CO/CO2 electrolysis
Authors: Duboviks V. , Maher R. C. , Kishimoto M. , Cohen L. F. , Brandon N. P. , Offer G. J.
Published: May 2014

In situ and ex situ Raman analyses of porous Ni/CGO electrodes reveal differences in the amount, location and type of carbon formed during CO/CO2 electrolysis. The majority of the carbon forms in the region of the anode, which lies in the range of ca. 4 micrometers from the electrode–electrolyte interface.
Reported and predicted structures of Ba(Co,Nb)1−δO3hexagonal perovskite phases
Authors: Bradley Kathryn A. , Collins Christopher , Dyer Matthew S. , Claridge John B. , Darling George R. , Rosseinsky Matthew J.
Published: May 2014

The Extended Module Materials Assembly method was implemented for close-packed hexagonal structures and applied to doped barium niobate perovskites.
Conversion efficiency of skutterudite-based thermoelectric modules
Authors: Salvador James R. , Cho Jung Y. , Ye Zuxin , Moczygemba Joshua E. , Thompson Alan J. , Sharp Jeffrey W. , Koenig Jan D. , Maloney Ryan , Thompson Travis , Sakamoto Jeffrey , Wang Hsin , Wereszczak Andrew A.
Published: May 2014

We describe materials and device preparation of high temperature capable skutterudite based thermoelectric modules and present their conversion efficiency.
Template-directed synthesis of metal–organic materials
Authors: Zhang Zhenjie , Zaworotko Michael J.
Published: May 2014

This tutorial review details the emergence of template-directed synthesis of metal–organic materials (MOMs) with emphasis upon reports of MOMs in which the template is retained, template@MOMs, and structurally characterized.
Oxygen content, crystal structure and chemical expansion of PrBaCo2−xFexO6−δ double perovskites
Authors: Tsvetkov D. S. , Ivanov I. L. , Malyshkin D. A. , Zuev A. Yu.
Published: May 2014

The oxygen content, crystal structure and chemical expansion of PrBaCo2−xFexO6−δ double perovskites have been investigated.
Contamination event detection using multiple types of conventional water quality sensors in source water
Authors: Liu Shuming , Che Han , Smith Kate , Chen Lei
Published: May 2014

A correlative relationship between multiple types of conventional sensors can be used to detect a contamination event.
Water-soluble fullerene materials for bioapplications: photoinduced reactive oxygen species generation
Authors: Yamakoshi Yoko , Aroua Safwan , Nguyen Thach-Mien Duong , Iwamoto Yuko , Ohnishi Tsuyoshi
Published: May 2014

The photoinduced reactive oxygen species (ROS) generation from several water-soluble fullerenes was examined. Macromolecular or small molecular water-soluble fullerene complexes/derivatives were prepared and their 1O2 and O2˙− generation abilities were evaluated by ESR spin-trapping methods. As a result, efficient 1O2 generation was detected from photoexcited C60, not only in organic solvents, but also in aqueous media and especially from small molecule C60–carboxylic acid derivatives. Whereas efficient O2˙− generation was observed in the aqueous solution of the C60/γ-CD complex under photoirradiation.
When proteins start to make sense: fine-tuning of aminoglycosides for PTC suppression therapy
Authors: Shalev Moran , Baasov Timor
Published: May 2014

The read-through mechanism of a premature stop codon.
Small-molecule phosphodiesterase probes: discovery of potent and selective CNS-penetrable quinazoline inhibitors of PDE1
Authors: Humphrey John M. , Yang Eddie , Ende Christopher W. am , Arnold Eric P. , Head Jenna L. , Jenkinson Stephen , Lebel Lorraine A. , Liras Spiros , Pandit Jayvardhan , Samas Brian , Vajdos Felix , Simons Samuel P. , Evdokimov Artem , Mansour Mahmoud , Menniti Frank S.
Published: May 2014

We describe the discovery of potent, selective, brain penetrable quinazoline inhibitors of PDE1 that represent valuable new tools for the dissection of related biological events.
Synthesis of cyclohexapeptides as antimalarial and anti-trypanosomal agents
Authors: Peña S. , Fagundez C. , Medeiros A. , Comini M. , Scarone L. , Sellanes D. , Manta E. , Tulla-Puche J. , Albericio F. , Stewart L. , Yardley V. , Serra G.
Published: May 2014

Azolic and non-azolic cyclohexapeptides were obtained and/or evaluated as promising antimalarial and/or anti-trypanosomal agents.
High-yield synthesis of poly(m-phenylenediamine) hollow nanostructures by a diethanolamine-assisted method and their enhanced ability for Ag+ adsorption
Authors: Su Zhen , Zhang Liyuan , Chai Liyuan , Wang Haiying , Yu Wanting , Wang Ting , Yang Jianxiong
Published: May 2014

DEA induces the formation of PmPD hollow nanostructures which exhibit improved adsorption performance.
DNA-binding studies and antioxidant activities of two-, three- and four-coordinate silver(i) complexes containing bis(2-benzimidazolyl)aniline derivatives
Authors: Wu Huilu , Zhang Yanhui , Chen Chengyong , Zhang Jiawen , Bai Yuchen , Shi Furong , Wang Xiaoli
Published: May 2014

Three novel structure Ag(i) complexes have been synthesized and characterized. The three ligands and Ag(i) complexes bind to DNA in an intercalation mode. The Ag(i) complexes have stronger ability of antioxidation for hydroxyl radical and superoxide radical.
Nanoscale-resolved elasticity: contact mechanics for quantitative contact resonance atomic force microscopy
Authors: Jakob A. M. , Buchwald J. , Rauschenbach B. , Mayr S. G.
Published: May 2014

Abilities of quantitative nanomechanical surface analysis are improved by a deeper understanding of influences on nanoscale contact physics.
Outstanding effects on antithrombin activity of modified TBA diastereomers containing an optically pure acyclic nucleotide analogue
Authors: Scuotto M. , Persico M. , Bucci M. , Vellecco V. , Borbone N. , Morelli E. , Oliviero G. , Novellino E. , Piccialli G. , Cirino G. , Varra M. , Fattorusso C. , Mayol L.
Published: May 2014

Optically pure modified acyclic nucleosides offer unique advantages in exploring the effect on thrombin inhibition of single residue modifications at key positions of TBA.
Polyamine modification by acrolein exclusively produces 1,5-diazacyclooctanes: a previously unrecognized mechanism for acrolein-mediated oxidative stress
Authors: Tsutsui Ayumi , Imamaki Rie , Kitazume Shinobu , Hanashima Shinya , Yamaguchi Yoshiki , Kaneda Masato , Oishi Shinya , Fujii Nobutaka , Kurbangalieva Almira , Taniguchi Naoyuki , Tanaka Katsunori
Published: May 2014

Polyamines were found to react with acrolein to produce 1,5-diazacyclooctane.
Efficient asymmetric synthesis of spiro-2(3H)-furanones via phase-transfer-catalyzed alkynylation
Authors: Wu Xiangfei , Shirakawa Seiji , Maruoka Keiji
Published: May 2014

Efficient asymmetric synthesis of spiro-2(3H)-furanones was achieved via chiral phase-transfer-catalyzed alkynylation.
From particles to stabilizing blocks – polymerized ionic liquids in aqueous heterophase polymerization
Authors: Yu Ran , Tauer Klaus
Published: May 2014

Dispersions of polymerized ionic liquids (PIL) are a new class of reactive stabilizers for aqueous heterophase polymerizations, which are either hydrophilic or hydrophobic with regard to their reaction partner.
One pot synthesis of higher order quasi-block copolymer librariesviasequential RAFT polymerization in an automated synthesizer
Authors: Haven Joris J. , Guerrero-Sanchez Carlos , Keddie Daniel J. , Moad Graeme , Thang San H. , Schubert Ulrich S.
Published: May 2014

The utility of automated high-throughput methods for the one pot synthesis of functional polymers of increased complexity is reported.
Microwave-assisted solution polycondensation of l-lactic acid using a Dean–Stark apparatus for a non-thermal microwave polymerization effect induced by the electric field
Authors: Yamada Shinji , Takasu Akinori , Takayama Sadatsugu , Kawamura Kazuhiko
Published: May 2014

The solution polycondensation of l-lactic acid (l-LA) in xylene catalyzed by Sc(OTf)3 was examined using a Dean–Stark apparatus under various microwave power conditions (100–400 W). The results indicate the existence of a non-thermal microwave effect induced by an electric field.
The kinetics of alkyl radical ring closures at selenium: formation of selenane
Authors: Hancock Amber N. , Kavanagh Yvonne , Schiesser Carl H.
Published: May 2014

Intramolecular homolytic substitution reactions of 5-(alkylseleno)pentyl radicals 4 have been investigated by competition kinetics as well as computational techniques.
Solution processed transparent nanoparticulate ZnO thin film electrode for photoelectrochemical water oxidation
Authors: Bora Debajeet K. , Braun Artur
Published: May 2014

A solution processed synthetic route has been developed for making transparent ZnO thin film having nanoparticle size of around 21 nm. Without additional modification ZnO films shows current density of 1 mA cm−2. The films also exhibit the production of oxygen gas from photo electrochemical water oxidation.
Effects of organic polymer addition in magnetite synthesis on the crystalline structure
Authors: Kuwahara Yoshimitsu , Miyazaki Toshiki , Shirosaki Yuki , Kawashita Masakazu
Published: May 2014

Various polymers with different functional groups and surface charges were added to the precursor solution of Fe3O4 to clarify the relationship between the chemical structure of the organic substances and the crystal structure of Fe3O4.
Multifactorial evaluation of the electrochemical response of a microbial fuel cell
Authors: Lepage G. , Perrier G. , Merlin G. , Aryal N. , Dominguez-Benetton X.
Published: May 2014

A lab-scale microbial fuel cell (MFC) with a reticulated vitreous carbon (RVC) anode and a non-catalyzed multi-layered carbon air-cathode was electrochemically characterized under various physicochemical factors: temperature (15–25 °C), phosphate buffer concentration (4–8 mM), acetate concentration (7.1–14.3 mM), and equivalent solution conductivity (2.5–5 mS cm−1).
Looking for links: examining student responses in creative exercises for evidence of linking chemistry concepts
Authors: Ye Li , Lewis Scott E.
Published: May 2014

Assumptive Learning Theory values the active process of linking concepts to promote meaningful over rote learning. To promote meaningful learning, assessment practices that encourage the linking of concepts need to be developed and utilized. Creative Exercises (CEs) have the potential to encourage such links. CEs are an open-ended assessment technique where students are given a single prompt and are asked to describe as many statements as they can that are distinct, correct, and relevant to the prompt. This study describes a qualitative investigation into student responses to CEs for evidence of students linking concepts throughout the course and the nature of the linked concepts. The findings indicate considerable interconnections of content in student responses. Further, students’ efforts toward making connections revealed several misconceptions regarding their understanding of the limits of models. CEs are therefore proposed as a means to encourage students to link concepts and to inform instructors about the links made, both correctly and incorrectly. Finally, to determine the prevalence of the incorrect links, a novel assessment technique is proposed based on students' responses to CEs.
Bulk crystal seeding in the generation of mesopores by organosilane surfactants in zeolite synthesis
Authors: Kim Jaeheon , Jo Changbum , Lee Seungjun , Ryoo Ryong
Published: May 2014

Bulk crystal seeding in hierarchical zeolite synthesis using organosilane surfactants – widening the mesopore-generating region and zeolite structures.
Effects of hydroxyapatite microparticle morphology on bone mesenchymal stem cell behavior
Authors: Yang Hui , Zeng Huijun , Hao Lijing , Zhao Naru , Du Chang , Liao Hua , Wang Yingjun
Published: May 2014

Hydroxyapatite (HAp) particles with different morphology but similar physicochemical properties were prepared by a novel and facile route. The interaction between the particles with BMSCs was investigated, and results revealed that particles’ shape has a strong influence on cellular behavior.
Broadly tuning Bi3+ emission via crystal field modulation in solid solution compounds (Y,Lu,Sc)VO4:Bi for ultraviolet converted white LEDs
Authors: Kang Fengwen , Peng Mingying , Yang Xiaobao , Dong Guoping , Nie Guochao , Liang Weijiang , Xu Shanhui , Qiu Jianrong
Published: May 2014

For phosphor-converted white LEDs based on UV chips, it is essential to search high efficient phosphors that better feature with broadly tunable emission and particularly have no or less excitation in visible ranges.
In situ photo-induced chemical doping of solution-processed graphene oxide for electronic applications
Authors: Savva K. , Lin Y.-H. , Petridis C. , Kymakis E. , Anthopoulos T. D. , Stratakis E.
Published: May 2014

In situ laser-induced chemical doping of solution-processed graphene oxide.
Polarized and non-polarized photoluminescence of GaInP2 alloy with partial CuPt-type atomic ordering: ordered domains vs. disordered regions
Authors: Ning J. Q. , Xu S. J. , Deng Z. , Su Z. C.
Published: May 2014

Polarized and non-polarized PL spectra of GaInP2 alloy at 4 K, 60 K, and 100 K.
Solution-based synthesis of anisotropic metal chalcogenide nanocrystals and their applications
Authors: Min Yuho , Moon Geon Dae , Kim Chang-Eun , Lee Ji-Hwan , Yang Heesung , Soon Aloysius , Jeong Unyong
Published: May 2014

This article reviews recent advances in solution-phase synthesis of anisotropic metal chalcogenide nanomaterials (1-D & 2-D) and their practical applications with some challenges in the solution-based synthesis.
Global adaptive output feedback tracking for a class of non‐linear systems with unknown backlash‐like hysteresis
Authors: Liu Ye , Lin Yan
Published: May 2014

The authors consider a class of non‐linear systems preceded by unknown backlash‐like hysteresis. Unlike other schemes dealing with hysteresis, the non‐linear systems of this study not only involve unknown parameters but also take non‐linear terms linear in the unmeasured states into account. An adaptive output feedback controller by utilising a modified high‐gain observer and backstepping approach is proposed, which is able to mitigate the effects of the hysteresis, and guarantee the global stability of the closed‐loop system and the arbitrarily small steady‐state tracking error. Moreover, it is proved that by introducing an initialisation technique, the ℒ∞ tracking performance can be achieved.
Evaluation of 2.0-mm Titanium Three-Dimensional Curved Angle Strut Plate in the Fixation of Mandibular Angle Fractures—A Prospective Clinical and Radiological Analysis
Authors: Chhabaria Gaurav , Halli Rajshekhar , Chandan Sanjay , Joshi Samir , Setiya Sneha , Shah Anand
Published: May 2014

The aim of the study was to evaluate the efficacy and complication rate with use of 2.0-mm titanium three-dimensional (3D) curved angle strut plate for mandibular angle fractures. Twenty cases requiring internal fixation of the mandibular angle by 2.0-mm titanium 3D curved angle strut plates were evaluated. Postoperative clinical and radiological analyses were done on 1st, 2nd, 4th, and 6th weeks, which included wound healing, transmitted movements, difficulty in function and occlusion, and neurosensory changes, if any. Reasonable level of success in terms of immediate jaw function was noted in all cases. Transient inferior alveolar nerve dysfunction was observed in three cases, which recovered gradually in 2 months, and surgical site infection was observed in two cases, which resolved with appropriate course of antibiotics and wound care. Fixation of mandibular angle fractures with a 2.0-mm titanium 3D curved angle strut plate is predictable, expeditious, and has less complication rate.
The Delay Phenomenon: A Compilation of Knowledge across Specialties
Authors: Hamilton Kristy , Wolfswinkel Erik M. , Weathers William M. , Xue Amy S. , Hatef Daniel A. , Izaddoost Shayan , Hollier Larry H.
Published: May 2014

Objective

The purpose of this article is to review and integrate the available literature in different fields to gain a better understanding of the basic physiology and optimize vascular delay as a reconstructive surgery technique.

Methods

A broad search of the literature was performed using the Medline database. Two queries were performed using “vascular delay,” a search expected to yield perspectives from the field of plastic and reconstructive surgery, and “ischemic preconditioning,” (IPC) which was expected to yield research on the same topic in other fields.

Results

The combined searches yielded a total of 1824 abstracts. The “vascular delay” query yielded 76 articles from 1984 to 2011. The “ischemic preconditioning” query yielded 6534 articles, ranging from 1980 to 2012. The abstracts were screened for those from other specialties in addition to reconstructive surgery, analyzed potential or current uses of vascular delay in practice, or provided developments in understanding the pathophysiology of vascular delay. 70 articles were identified that met inclusion criteria and were applicable to vascular delay or ischemic preconditioning.

Conclusion

An understanding of IPC's implementation and mechanisms in other fields has beneficial implications for the field of reconstructive surgery in the context of the delay phenomenon. Despite an incomplete model of IPC's pathways, the anti-oxidative, anti-apoptotic and anti-inflammatory benefits of IPC are well recognized. The activation of angiogenic genes through IPC could allow for complex flap design, even in poorly vascularized regions. IPC's promotion of angiogenesis and reduction of endothelial dysfunction remain most applicable to reconstructive surgery in reducing graft-related complications and flap failure.
Isotope effects and spectroscopic assignments in the non-dissociative photoionization spectrum of N2
Authors: Randazzo John B. , Croteau Philip , Kostko Oleg , Ahmed Musahid , Boering Kristie A.
Published: May 2014

Photoionization efficiency spectra of 14N2, 15N14N, and 15N2 from 15.5 to 18.9 eV were measured using synchrotron radiation at the Advanced Light Source at Lawrence Berkeley National Laboratory with a resolution of 6 meV, and significant changes in peak energies and intensities upon isotopic substitution were observed. Previously, we reported the isotope shifts and their applications to Titan's atmosphere. Here, we report more extensive experimental details and tabulate the isotope shifts of many transitions in the N2 spectrum, including those for 15N14N, which have not been previously reported. The isotope shifts are used to address several long-standing ambiguities in spectral peak assignments just above the ionization threshold of N2. The feature at 15.677 eV (the so-called second “cathedral” peak) is of particular interest in this respect. The measured isotope shifts for this peak relative to 14N2 are 0.015 ± 0.001 eV for 15N2 and 0.008 ± 0.001 eV for 15N14N, which match most closely with the isotope shifts predicted for transitions to the (A 2Πu v′ = 2)4sσg 1Πu state using Herzberg equations for the isotopic differences in harmonic oscillator energy levels plus the first anharmonic correction of 0.0143 eV for 15N2 and 0.0071 eV for 15N14N. More generally, the isotope shifts measured for both 15N2 and 15N14N relative to 14N2 provide new benchmarks for theoretical calculations of interferences between direct and indirect autoionization states which can interact to produce intricate resonant structures in molecular photoionization spectra in regions near ionization thresholds.
Benchmarking kinetic calculations of resistive wall mode stability
Authors: Berkery J. W. , Liu Y. Q. , Wang Z. R. , Sabbagh S. A. , Logan N. C. , Park J.-K. , Manickam J. , Betti R.
Published: May 2014

Validating the calculations of kinetic resistive wall mode (RWM) stability is important for confidently predicting RWM stable operating regions in ITER and other high performance tokamaks for disruption avoidance. Benchmarking the calculations of the Magnetohydrodynamic Resistive Spectrum—Kinetic (MARS-K) [Y. Liu et al., Phys. Plasmas 15, 112503 (2008)], Modification to Ideal Stability by Kinetic effects (MISK) [B. Hu et al., Phys. Plasmas 12, 057301 (2005)], and Perturbed Equilibrium Nonambipolar Transport (PENT) [N. Logan et al., Phys. Plasmas 20, 122507 (2013)] codes for two Solov'ev analytical equilibria and a projected ITER equilibrium has demonstrated good agreement between the codes. The important particle frequencies, the frequency resonance energy integral in which they are used, the marginally stable eigenfunctions, perturbed Lagrangians, and fluid growth rates are all generally consistent between the codes. The most important kinetic effect at low rotation is the resonance between the mode rotation and the trapped thermal particle's precession drift, and MARS-K, MISK, and PENT show good agreement in this term. The different ways the rational surface contribution was treated historically in the codes is identified as a source of disagreement in the bounce and transit resonance terms at higher plasma rotation. Calculations from all of the codes support the present understanding that RWM stability can be increased by kinetic effects at low rotation through precession drift resonance and at high rotation by bounce and transit resonances, while intermediate rotation can remain susceptible to instability. The applicability of benchmarked kinetic stability calculations to experimental results is demonstrated by the prediction of MISK calculations of near marginal growth rates for experimental marginal stability points from the National Spherical Torus Experiment (NSTX) [M. Ono et al., Nucl. Fusion 40, 557 (2000)].
Line-space description of resonant four-wave mixing: Theory for isotropic molecular states
Authors: Kouzov A. , Radi P.
Published: May 2014

Based on the quantum Liouville formalism, a theory of the two-color, triply resonant four-wave mixing is developed for molecules with isotropically oriented angular momenta. The approach allows to strictly incorporate the relaxation matrices Γ(r) (r = 0, 1, 2) into the third-order susceptibility χ(3) whose expression acquires therewith the form of a scalar product in the line space. Thanks to this representation, isolation of all resonance terms from χ(3) becomes a routine task. Some of these terms correspond to the case when a molecule initially interacts with two pump photons of the same frequency. Such interactions give rise to the grating line-space vectors which have the same (zero) eigenfrequency. Due to this degeneracy, the latter are easily mixed by rotationally inelastic collisions which shows up in a state-resolved coherence transfer. The satellite signals induced thereby provide a great scope to study the state-to-state inelastic rates in situ by purely optical means. If the diagonal form of Γ is assumed, the satellites become forbidden and our results reduce to conventional expressions for the main resonances. Polarization configurations are designed for direct measurements of the population (r = 0), orientation (r = 1), and alignment (r = 2) contributions to χ(3). Finally, depending on the photon-molecule interaction sequence, the resonance terms of χ(3) are shown to be differently affected by velocity averaging, the effect which conspicuously manifests itself when Doppler broadening becomes paramount.
Concentration fluctuations in miscible polymer blends: Influence of temperature and chain rigidity
Authors: Dudowicz Jacek , Freed Karl F. , Douglas Jack F.
Published: May 2014

In contrast to binary mixtures of small molecule fluids, homogeneous polymer blends exhibit relatively large concentration fluctuations that can strongly affect the transport properties of these complex fluids over wide ranges of temperatures and compositions. The spatial scale and intensity of these compositional fluctuations are studied by applying Kirkwood-Buff theory to model blends of linear semiflexible polymer chains with upper critical solution temperatures. The requisite quantities for determining the Kirkwood-Buff integrals are generated from the lattice cluster theory for the thermodynamics of the blend and from the generalization of the random phase approximation to compressible polymer mixtures. We explore how the scale and intensity of composition fluctuations in binary blends vary with the reduced temperature τ ≡ (T − Tc)/T (where Tc is the critical temperature) and with the asymmetry in the rigidities of the components. Knowledge of these variations is crucial for understanding the dynamics of materials fabricated from polymer blends, and evidence supporting these expectations is briefly discussed.
A high precision, compact electromechanical ground rotation sensor
Authors: Dergachev V. , DeSalvo R. , Asadoor M. , Bhawal A. , Gong P. , Kim C. , Lottarini A. , Minenkov Y. , Murphy C. , O'Toole A. , Peña Arellano F. E. , Rodionov A. V. , Shaner M. , Sobacchi E.
Published: May 2014

We present a mechanical rotation sensor consisting of a balance pivoting on a tungsten carbide knife edge. These sensors are important for precision seismic isolation systems, as employed in land-based gravitational wave interferometers and for the new field of rotational seismology. The position sensor used is an air-core linear variable differential transformer with a demonstrated noise floor of \documentclass[12pt]{minimal}\begin{document}${1}{\,\times\, 10^{-11}}\textrm { m}/\sqrt{\textrm {Hz}}$\end{document}1×10−11m/ Hz . We describe the instrument construction and demonstrate low noise operation with a noise floor upper bound of \documentclass[12pt]{minimal}\begin{document}${5.7}{\,\times\, 10^{-9}}\textrm { rad}/\sqrt{\textrm {Hz}}$\end{document}5.7×10−9 rad / Hz at 10 mHz and \documentclass[12pt]{minimal}\begin{document}${6.4}{\,\times\, 10^{-10}}\textrm { rad}/\sqrt{\textrm {Hz}}$\end{document}6.4×10−10 rad / Hz at 0.1 Hz. The performance of the knife edge hinge is compatible with a behaviorur free of noise from dislocation self-organized criticality.
Note: On the measurement of plasma potential fluctuations using emissive probes
Authors: Bousselin G. , Lemoine N. , Cavalier J. , Heuraux S. , Bonhomme G.
Published: May 2014

In this Note, it is pointed out that emissive probes cannot be used to directly and reliably measure plasma potential fluctuations. An experimentally validated model demonstrates indeed that the floating potential fluctuations of an emissive probe which floats at the mean plasma potential depend not only on the plasma potential fluctuations but also on electron density and temperature fluctuations.
Structure, solvation, and dynamics of Mg2+, Ca2+, Sr2+, and Ba2+ complexes with 3-hydroxyflavone and perchlorate anion in acetonitrile medium: A molecular dynamics simulation study
Authors: Agieienko Vira N. , Kolesnik Yaroslav V. , Kalugin Oleg N.
Published: May 2014

Molecular dynamics simulations of complexes of Mg2+, Ca2+, Sr2+, and Ba2+ with 3-hydroxyflavone (flavonol, 3HF) and ${\rm ClO}_{\rm 4} ^ -$ ClO 4− in acetonitrile were performed. The united atoms force field model was proposed for the 3HF molecule using the results of DFT quantum chemical calculations. 3HF was interpreted as a rigid molecule with two internal degrees of freedom, i.e., rotation of the phenyl ring and of the OH group with respect to the chromone moiety. The interatomic radial distribution functions showed that interaction of the cations with flavonol occurs via the carbonyl group of 3HF and it is accompanied with substitution of one of the acetonitrile molecules in the cations’ first solvation shells. Formation of the cation–3HF complexes does not have significant impact on the rotation of the phenyl ring with respect to the chromone moiety. However, the orientation of the flavonol's OH-group is more sensitive to the interaction with doubly charged cations. When complex with Mg2+ is formed, the OH-group turns out of the plane of the chromone moiety that leads to rupture of intramolecular H-bond in the ligand molecule. Complexation of Ca2+, Sr2+, and ${\rm BaClO}_4 ^ +$ BaClO 4+ with 3HF produces two structures with different OH-positions, as in the free flavonol with the intramolecular H-bond and as in the complex with Mg2+ with disrupted H-bonding. It was shown that additional stabilization of the [MgClO4(3HF)]+ and [BaClO4(3HF)]+ complexes is determined by strong affinity of perchlorate anion to interact with flavonol via intracomplex hydrogen bond between an oxygen atom of the anion and the hydrogen atom of the 3-hydroxyl group. Noticeable difference in the values of the self-diffusion coefficients for Kt2+ from one side and ${\rm ClO}_{\rm 4} ^ -$ ClO 4−, 3HF, and AN in the cations’ coordination shell from another side implies quite weak interaction between cation, anion, and ligands in the investigated complexes.
Enhanced stopping of macro-particles in particle-in-cell simulations
Authors: May J. , Tonge J. , Ellis I. , Mori W. B. , Fiuza F. , Fonseca R. A. , Silva L. O. , Ren C.
Published: May 2014

We derive an equation for energy transfer from relativistic charged particles to a cold background plasma appropriate for finite-size particles that are used in particle-in-cell simulation codes. Expressions for one-, two-, and three-dimensional particles are presented, with special attention given to the two-dimensional case. This energy transfer is due to the electric field of the wake set up in the background plasma by the relativistic particle. The enhanced stopping is dependent on the q2/m, where q is the charge and m is the mass of the relativistic particle, and therefore simulation macro-particles with large charge but identical q/m will stop more rapidly. The stopping power also depends on the effective particle shape of the macro-particle. These conclusions are verified in particle-in-cell simulations. We present 2D simulations of test particles, relaxation of high-energy tails, and integrated fast ignition simulations showing that the enhanced drag on macro-particles may adversely affect the results of these simulations in a wide range of high-energy density plasma scenarios. We also describe a particle splitting algorithm which can potentially overcome this problem and show its effect in controlling the stopping of macro-particles.
Analytic studies of dispersive properties of shear Alfvén and acoustic wave spectra in tokamaks
Authors: Chavdarovski Ilija , Zonca Fulvio
Published: May 2014

The properties of the low frequency shear Alfvén and acoustic wave spectra in toroidal geometry are examined analytically and numerically considering wave particle interactions with magnetically trapped and circulating particles, using the theoretical model described in [I. Chavdarovski and F. Zonca, Plasma Phys. Controlled Fusion 51, 115001 (2009)] and following the framework of the generalized fishbone-like dispersion relation. Effects of trapped particles as well as diamagnetic effects on the frequencies and damping rates of the beta-induced Alfvén eigenmodes, kinetic ballooning modes and beta-induced Alfvén-acoustic eigenmodes are discussed and shown to be crucial to give a proper assessment of mode structure and stability conditions. Present results also demonstrate the mutual coupling of these various branches and suggest that frequency as well as mode polarization are crucial for their identification on the basis of experimental evidence.
Combined x-ray scattering, radiography, and velocity interferometry/streaked optical pyrometry measurements of warm dense carbon using a novel technique of shock-and-release
Authors: Falk K. , Collins L. A. , Gamboa E. J. , Kagan G. , Kress J. D. , Montgomery D. S. , Srinivasan B. , Tzeferacos P. , Benage J. F.
Published: May 2014

This work focused on a new application of the shock-and-release technique for equation of state (EOS) measurements. Warm dense matter states at near normal solid density and at temperatures close to 10 eV in diamond and graphite samples were created using a deep release from a laser-driven shock at the OMEGA laser facility. Independent temperature, density, and pressure measurements that do not depend on any theoretical models or simulations were obtained using imaging x-ray Thomson scattering, radiography, velocity interferometry, and streaked optical pyrometry. The experimental results were reproduced by the 2-D FLASH radiation hydrodynamics simulations finding a good agreement. The final EOS measurement was then compared with widely used SESAME EOS models as well as quantum molecular dynamics simulation results for carbon, which were very consistent with the experimental data.
Communication: Imaging the effects of the antisymmetric-stretching excitation in the O(3P) + CH4(v3 = 1) reaction
Authors: Pan Huilin , Liu Kopin
Published: May 2014

Effects of one-quantum excitation of the antisymmetric-stretching mode of CH4(v3 = 1) on the O(3P) + CH4 reaction were studied in a crossed-beam, ion-imaging experiment. In the post-threshold region, we found that (1) the product state distributions are dominated by the CH3(00) + OH(v′ = 1) pair, (2) the product angular distributions extend toward sideways from the backward dominance of the ground-state reaction, and (3) vibrational excitation exerts a positive effect on reactivity, but translational energy is more efficient in promoting the rate of this central-barrier reaction. All major findings agree reasonably well with recent theoretical results. Some remaining questions are pointed out.
Relative light yield and temporal response of a stilbene-doped bibenzyl organic scintillator for neutron detection
Authors: Brown J. A. , Goldblum B. L. , Bernstein L. A. , Bleuel D. L. , Brickner N. M. , Caggiano J. A. , Daub B. H. , Kaufman G. S. , Hatarik R. , Phillips T. W. , Wender S. A. , van Bibber K. , Vujic J. , Zaitseva N. P.
Published: May 2014

The neutron time-of-flight (nTOF) diagnostics used to characterize implosions at the National Ignition Facility (NIF) has necessitated the development of novel scintillators that exhibit a rapid temporal response and high light yield. One such material, a bibenzyl-stilbene mixed single-crystal organic scintillator grown in a 99.5:0.5 ratio in solution, has become the standard scintillator used for nTOF diagnostics at NIF. The prompt fluorescence lifetime and relative light yield as a function of proton energy were determined to calibrate this material as a neutron detector. The temporal evolution of the intensity of the prompt fluorescent response was modeled using first-order reaction kinetics and the prompt fluorescence decay constant was determined to be 2.46 ± 0.01 (fit) ± 0.13 (systematic) ns. The relative response of the bibenzyl-stilbene mixed crystal generated by recoiling protons was measured, and results were analyzed using Birks' relation to quantify the non-radiative quenching of excitation energy in the scintillator.
High-performance photocurrent generation from two-dimensional WS2 field-effect transistors
Authors: Hwan Lee Seung , Lee Daeyeong , Sik Hwang Wan , Hwang Euyheon , Jena Debdeep , Jong Yoo Won
Published: May 2014

The generation of a photocurrent from two-dimensional tungsten disulfide (WS2) field-effect transistors is examined here, and its dependence on the photon energy is characterized. We found from the WS2 devices that a significant enhancement in the ratio of illuminated current against dark current (Iillum/Idark) of ∼102–103 is attained, even with the application of electric fields of ED = 0.02 and EG = −22 mV/nm, which are much smaller than that of the bulk MoS2 phototransistor. Most importantly, we demonstrate that our multilayer WS2 shows an extremely high external quantum efficiency of ∼7000%, even with the smallest electrical field applied. We also found that photons with an energy near the direct band gap of the bulk WS2, in the range of 1.9–2.34 eV, give rise to a photoresponsivity of ∼0.27 A/W, which exceeds the photoresponsivity of the bulk MoS2 phototransistor. The superior photosensing properties of WS2 demonstrated in this work are expected to be utilized in the development of future high performance two-dimensional optoelectronic devices.
Effect of oxide/oxide interface on polarity dependent resistive switching behavior in ZnO/ZrO2 heterostructures
Authors: Xu Zedong , Yu Lina , Xu Xiaoguang , Miao Jun , Jiang Yong
Published: May 2014

The effect of oxide/oxide interface for controlling the migration process of oxygen vacancies (or oxygen ions) on resistive switching behaviors has been investigated by fabricating the ZrO2/ZnO oxide heterostructures. Completely different resistive switching behaviors are observed in the heterostructures with a set process under a different bias polarity. It is demonstrated that the change of the oxide/oxide interface barrier height determining the migration of oxygen vacancies (or oxygen ions) leads to the current direction-dependent resistive switching. Furthermore, the ZnO/ZrO2 heterostructure with the homogeneous resistive switching behavior could be potentially applied as a controllable and stable multistate memory by controlling reset-stop voltages. Our method opens up an opportunity to explore the resistive switching mechanism and develop resistance switching devices with specific functions through engineering oxide/oxide interfaces in oxide heterostructures.
Graphene nanoribbon superlattices fabricated via He ion lithography
Authors: Archanjo Braulio S. , Fragneaud Benjamin , Gustavo Cançado Luiz , Winston Donald , Miao Feng , Alberto Achete Carlos , Medeiros-Ribeiro Gilberto
Published: May 2014

Single-step nano-lithography was performed on graphene sheets using a helium ion microscope. Parallel “defect” lines of ∼1 μm length and ≈5 nm width were written to form nanoribbon gratings down to 20 nm pitch. Polarized Raman spectroscopy shows that crystallographic orientation of the nanoribbons was partially maintained at their lateral edges, indicating a high-fidelity lithography process. Furthermore, Raman analysis of large exposure areas with different ion doses reveals that He ions produce point defects with radii ∼ 2× smaller than do Ga ions, demonstrating that scanning-He+-beam lithography can texture graphene with less damage.
Effects of the dynamics of droplet-based laser-produced plasma on angular extreme ultraviolet emission profile
Authors: Giovannini Andrea Z. , Abhari Reza S.
Published: May 2014

The emission distribution of extreme ultraviolet (EUV) radiation from droplet targets is dependent on the dynamics of the laser-produced plasma. The EUV emission is measured on a 2% bandwidth centered at 13.5 nm (in-band). The targets of the laser are small (sub-50 μm) tin droplets, and the in-band emission distribution is measured for different laser irradiances and droplet sizes at various angular positions. Larger droplets lead to a faster decay of EUV emission at larger angles with respect to the laser axis. A decrease in laser irradiance has the opposite effect. The measurements are used together with an analytical model to estimate plume dynamics. Additionally, the model is used to estimate EUV emission distribution for a desired droplet diameter and laser irradiance.
Performance limits of tunnel transistors based on mono-layer transition-metal dichalcogenides
Authors: Jiang Xiang-Wei , Li Shu-Shen
Published: May 2014

Performance limits of tunnel field-effect transistors based on mono-layer transition metal dichalcogenides are investigated through numerical quantum mechanical simulations. The atomic mono-layer nature of the devices results in a much smaller natural length λ, leading to much larger electric field inside the tunneling diodes. As a result, the inter-band tunneling currents are found to be very high as long as ultra-thin high-k gate dielectric is possible. The highest on-state driving current is found to be close to 600 μA/μm at Vg = Vd = 0.5 V when 2 nm thin HfO2 layer is used for gate dielectric, outperforming most of the conventional semiconductor tunnel transistors. In the five simulated transition-metal dichalcogenides, mono-layer WSe2 based tunnel field-effect transistor shows the best potential. Deep analysis reveals that there is plenty room to further enhance the device performance by either geometry, alloy, or strain engineering on these mono-layer materials.
Mucilage exudation facilitates root water uptake in dry soils
Authors: Ahmed Mutez A. , Kroener Eva , Holz Maire , Zarebanadkouki Mohsen , Carminati Andrea
Published: May 2014

As plant roots take up water and the soil dries, water depletion is expected to occur in the rhizosphere. However, recent experiments showed that the rhizosphere was wetter than the bulk soil during root water uptake. We hypothesise that the increased water content in the rhizosphere was caused by mucilage exuded by roots. It is probably that the higher water content in the rhizosphere results in higher hydraulic conductivity of the root–soil interface. In this case, mucilage exudation would favour the uptake of water in dry soils. To test this hypothesis, we covered a suction cup, referred to as an artificial root, with mucilage. We placed it in soil with a water content of 0.03 cm3 cm–3, and used the root pressure probe technique to measure the hydraulic conductivity of the root–soil continuum. The results were compared with measurements with roots not covered with mucilage. The root pressure relaxation curves were fitted with a model of root water uptake including rhizosphere dynamics. The results demonstrated that when mucilage is added to the root surface, it keeps the soil near the roots wet and hydraulically well conductive, facilitating the water flow from dry soils towards the root surface. Mucilage exudation seems to be an optimal plant trait that favours the capture of water when water is scarce.
Feature overlap slows lexical selection: Evidence from the picture–word interference paradigm
Authors: Vieth H. E. , McMahon K. L. , de Zubicaray G. I.
Published: May 2014

How does the presence of a categorically related word influence picture naming latencies? In order to test competitive and noncompetitive accounts of lexical selection in spoken word production, we employed the picture–word interference (PWI) paradigm to investigate how conceptual feature overlap influences naming latencies when distractors are category coordinates of the target picture. Mahon et al. (2007. Lexical selection is not by competition: A reinterpretation of semantic interference and facilitation effects in the picture-word interference paradigm. Journal of Experimental Psychology. Learning, Memory, and Cognition, 33(3), 503–535. doi:10.1037/0278-7393.33.3.503 ) reported that semantically close distractors (e.g., zebra) facilitated target picture naming latencies (e.g., HORSE) compared to far distractors (e.g., whale). We failed to replicate a facilitation effect for within-category close versus far target–distractor pairings using near-identical materials based on feature production norms, instead obtaining reliably larger interference effects (Experiments 1 and 2). The interference effect did not show a monotonic increase across multiple levels of within-category semantic distance, although there was evidence of a linear trend when unrelated distractors were included in analyses (Experiment 2). Our results show that semantic interference in PWI is greater for semantically close than for far category coordinate relations, reflecting the extent of conceptual feature overlap between target and distractor. These findings are consistent with the assumptions of prominent competitive lexical selection models of speech production.
The Short‐Run Impact of the Healthy Incentives Pilot Program on Fruit and Vegetable Intake
Authors: Klerman Jacob A. , Bartlett Susan , Wilde Parke , Olsho Lauren
Published: May 2014

In response to low consumption levels of fruits and vegetables by Supplemental Nutrition Assistance Program (SNAP) participants, the USDA Food and Nutrition Service created the Healthy Incentives Pilot (HIP) to test the efficacy of providing a 30% incentive for purchases of targeted fruits and vegetables (TFVs). Four to six months after implementation, mean daily TFV intake for adult HIP participants was 0.22 cup‐equivalents higher (24% higher) than for control‐group SNAP participants. These impact estimates with a random‐assignment research design generally agree with previously published nonexperimental elasticity estimates, which imply that a pure price reduction of 30% would increase fruit and vegetable consumption by about 20%.
Combination of longitudinal biomarkers in predicting binary events
Authors: Liu Danping , Albert Paul S.
Published: May 2014

In disease screening, the combination of multiple biomarkers often substantially improves the diagnostic accuracy over a single marker. This is particularly true for longitudinal biomarkers where individual trajectory may improve the diagnosis. We propose a pattern mixture model (PMM) framework to predict a binary disease status from a longitudinal sequence of biomarkers. The marker distribution given the disease status is estimated from a linear mixed effects model. A likelihood ratio statistic is computed as the combination rule, which is optimal in the sense of the maximum receiver operating characteristic (ROC) curve under the correctly specified mixed effects model. The individual disease risk score is then estimated by Bayes’ theorem, and we derive the analytical form of the 95% confidence interval. We show that this PMM is an approximation to the shared random effects (SRE) model proposed by Albert (2012. A linear mixed model for predicting a binary event from longitudinal data under random effects mis-specification. Statistics in Medicine31(2), 143–154). Further, with extensive simulation studies, we found that the PMM is more robust than the SRE model under wide classes of models. This new PPM approach for combining biomarkers is motivated by and applied to a fetal growth study, where the interest is in predicting macrosomia using longitudinal ultrasound measurements.