bluuebunny/crossref_metadata_2025 huggingface dataset:
Do we need covalent bonding of Si nanoparticles on graphene oxide for Li-ion batteries?
Authors: Miroshnikov Yana , Grinbom Gal , Gershinsky Gregory , Nessim Gilbert D. , Zitoun David
Published: June 2014

In this manuscript, we report our investigation of anode materials for Li-ion batteries based on silicon–graphene oxide composites. Previous reports in the literature on silicon–graphene oxide (GO) composites as anodes have shown a large discrepancy between the electrochemical properties, mainly capacity and coulombic efficiency. In our research, the surface chemistry of Si nanoparticles has been functionalized to yield a chemical bond between the Si and GO, a further annealing step yields a Si–reduced GO (Si–rGO) composite while controlled experiments have been carried on mechanical mixing of GO and Si. For all samples, including a simple mixing of Si nanoparticles and GO, a high specific capacity of 2000 mA h gSi−1can be achieved for 50 cycles. The main difference between the samples can be observed in terms of coulombic efficiency, which will determine the future of these composites in full Li-ion cells. The Si–rGO composite shows a very low capacity fading and a coulombic efficiency above 99%. Furthermore, the Si–rGO composite can be cycled at very high rate to 20 C (charge in 3 minutes).
Ionic liquids as porogens for molecularly imprinted polymers: propranolol, a model study
Authors: Booker Katherine , Holdsworth Clovia I. , Doherty Cara M. , Hill Anita J. , Bowyer Michael C. , McCluskey Adam
Published: June 2014

The selectivity and rebinding capacity of molecularly imprinted polymers selective for propranolol (1) using the room temperature ionic liquids [BMIM][BF4], [BMIM][PF6], [HMIM][PF6] and [OMIM][PF6] and CHCl3were examined.
Catalytic asymmetric nucleophilic openings of 3-substituted oxetanes
Authors: Wang Zhaobin , Chen Zhilong , Sun Jianwei
Published: June 2014

Important progress has been made in catalytic asymmetric ring-opening of 3-substituted oxetanes, but significant challenges and opportunities remain.
Chronopotentiometric synthesis of quantum dots with efficient surface-derived near-infrared electrochemiluminescence for ultrasensitive microchip-based ion-selective sensing
Authors: Deng Shengyuan , Zhang Tingting , Zhang Yuan , Shan Dan , Zhang Xueji
Published: June 2014

Metalantidote-stabilized QDs were synthesized via hydrodynamic chronopotentiometry with efficient NIR-ECL derived from the unique surface states for ultrasensitive microchip-based ion-selective sensing.
Substituent effect in theoretical VCD spectra
Authors: Lipiński Piotr F. J. , Dobrowolski Jan Cz.
Published: June 2014

A correlational study shows for the first time a quantitative substituent effect on Vibrational Circular Dichroism intensity.
The pros and cons of lignin valorisation in an integrated biorefinery
Authors: Strassberger Zea , Tanase Stefania , Rothenberg Gadi
Published: June 2014

Wood to chemicals is the subject of this short critical review, that outlines the chemical and economic aspects of several short-term and long-term perspectives for the valorisation of lignin to aromatics, polymers and materials.
Cabbage leaf-shaped two-dimensional TiO2mesostructures for efficient dye-sensitized solar cells
Authors: Deepak T. G. , Anjusree G. S. , Pai K. R. Narendra , Subash Devika , Nair Shantikumar V. , Nair A. Sreekumaran
Published: June 2014

Photovoltaic property (an efficiency of 7.92%) of the cabbage-leaf-like TiO2mesostructures synthesized from electrospun TiO2–SiO2composite nanofibers by a modified titanate route.
Rules for priming and inhibition of glycosaminoglycan biosynthesis; probing the β4GalT7 active site
Authors: Siegbahn Anna , Manner Sophie , Persson Andrea , Tykesson Emil , Holmqvist Karin , Ochocinska Agata , Rönnols Jerk , Sundin Anders , Mani Katrin , Westergren-Thorsson Gunilla , Widmalm Göran , Ellervik Ulf
Published: June 2014

Xylose is the optimal substrate for β4GalT7, an essential enzyme in GAG biosynthesis, but analogs act as effective inhibitors.
Understanding selective molecular recognition in integrated carbon nanotube–polymer sensors by simulating physical analyte binding on carbon nanotube–polymer scaffolds
Authors: Lin Shangchao , Zhang Jingqing , Strano Michael S. , Blankschtein Daniel
Published: June 2014

Coarse-grained molecular dynamics simulation (left) is used to predict various analyte binding affinities onto SWCNT-polymer scaffolds (new sensor motifs), which are correlated with their photoluminescence signals (right) to understand sensing selectivity.
pH-activatable near-infrared fluorescent probes for detection of lysosomal pH inside living cells
Authors: Vegesna Giri K. , Janjanam Jagadeesh , Bi Jianheng , Luo Fen-Tair , Zhang Jingtuo , Olds Connor , Tiwari Ashutosh , Liu Haiying
Published: June 2014

Four near-infrared fluorescent probes have been synthesized, characterized, and evaluated for detection of lysosomal pH inside living cells.
pH-responsive hierarchical transformation of charged lipid assemblies within polyelectrolyte gel layers with applications for controlled drug release and MR imaging contrast
Authors: Huang Yi-Fong , Chiang Wen-Hsuan , Huang Wen-Chia , Chen Hsin-Hung , Shen Ming-Yin , Lin Sung-Chyr , Chern Chorng-Shyan , Chiu Hsin-Cheng
Published: June 2014

Cationic DOTAP assemblies within poly(acrylic acid) gel effectively modulate drug release and MR imaging contrast by pH-induced morphological transformation.
Oil-in-water microemulsion: an effective medium for triplet–triplet annihilated upconversion with efficient triplet acceptors
Authors: Ye Changqing , Wang Bao , Hao Roukang , Wang Xiaomei , Ding Ping , Tao Xutang , Chen Zhigang , Liang Zuoqin , Zhou Yuyang
Published: June 2014

An upconverted oil-in-water microemulsion containing a bimolecular system was first reported for the triplet–triplet annihilated upconversion by temperature effects.
Ca2+ switches the effect of PS-containing membranes on Factor Xa from activating to inhibiting: implications for initiation of blood coagulation
Authors: Koklic Tilen , Majumder Rinku , Lentz Barry R.
Published: June 2014

Calcium (Ca2+) plays a pivotal role in cellular and organismal physiology. The Ca2+ ion has an intermediate protein-binding affinity and thus it can serve as an on/off switch in the regulation of different biochemical processes. The serum level of ionized Ca2+ is regulated with normal ionized Ca2+ being in the range 1.10–1.3 mM. Hypocalcaemia (free Ca2+<1.1 mM) in critically ill patients is commonly accompanied by haemostatic abnormalities, ranging from isolated thrombocytopenia to complex defects such as disseminated intravascular coagulation, commonly thought to be due to insufficient functioning of anticoagulation pathways. A small amount of fXa (Factor Xa) produced by Factor VIIa and exposed tissue factor is key to initiating blood coagulation by producing enough thrombin to induce the later stages of coagulation. fXa must bind to PS (phosphatidylserine)-containing membranes to produce thrombin at a physiologically significant rate. In the present study, we show that overall fXa activity on PS-containing membranes is sharply regulated by a ‘Ca2+ switch’ centred at 1.16 mM, below which fXa is active and above which fXa forms inactive dimers on PS-exposing membranes. Our data lead to a mathematical model that predicts the variation of fXa activity as a function of both Ca2+ and membrane concentrations. Because the critical Ca2+ concentration is at the lower end of the normal plasma ionized Ca2+ concentration range, we propose a new regulatory mechanism by which local Ca2+ concentration switches fXa from an intrinsically active form to a form requiring its cofactor [fVa (Factor Va)] to achieve significant activity.
Polyproline promotes tetramerization of recombinant human butyrylcholinesterase
Authors: Larson Marilynn A. , Lockridge Oksana , Hinrichs Steven H.
Published: June 2014

Human BChE (butyrylcholinesterase) protects against the toxicity of organophosphorus nerve agents and pesticides. BChE purified from human plasma is limited and pathogen carry-over is a concern. Unlike the native BChE tetrameric complex with a residence time of days, rBChE (recombinant BChE) is produced predominantly as dimers and monomers that are cleared from the circulation within minutes. Assembly into tetramers requires incorporation of proline-rich peptides, a process that was thought to occur intracellularly. Our goal was to determine whether polyproline added to rBChE under cell-free conditions would promote tetramerization. Secreted rBChE was purified by procainamide affinity chromatography, and synthetic polyprolines (8-mer to 300-mer) were tested to determine their effect on tetramer assembly. These studies demonstrated that 90–98% of purified rBChE (65 μM) could be assembled into tetramers when incubated with synthetic 17-mer or 50-mer polyproline peptides (100 μM) for 1.5 h at 25°C. However, rBChE tetramerization was inefficient with smaller 8-mer polyproline peptides and larger 300-mer polyproline proteins. Collectively, these studies demonstrated that the eukaryotic cellular machinery is not required for assembly of active BChE into tetramers and that this process can occur in vitro with purified rBChE in the presence of peptides containing 15–50 consecutive proline residues.
POPA: localising nodes by splitting PLA with nth‐hop anchor neighbours
Authors: Chen Liangyin , Xiong Xunde , Liu Kai , Wang Chaolong , Zhou Weichao , Cheng Yanhong , Luo Qian , Liu Yan
Published: June 2014

A novel distributed range‐free localisation algorithm, named polygonal overlapped possible area (POPA), is proposed to accurately localise an unknown node. First, for an unknown node, to theoretically define its possible localisation area (PLA), virtual radiation regions of its nth‐hop anchor neighbours are introduced. Then an effective area‐splitting algorithm is employed to simplify and speed up the computation of the possible localisation area. Simulation shows localisation error can be controlled within 20% with off‐the‐shelf devices.
Poly‐Si active matrix organic light‐emitting diode pixel circuit with compensation for threshold voltage and mobility variations
Authors: Nam Ilku , Woo Doo Hyung
Published: June 2014

A new pixel circuit and driving method for large‐area, high‐luminance active matrix organic light‐emitting diode (AMOLED) displays were studied to improve the image quality. The AMOLED display was designed with low‐temperature poly‐silicon thin film transistors (TFTs), which have good stability but poor uniformity. To overcome the uniformity problem, the proposed pixel circuit compensates for variations in the threshold voltage and the mobility of the driving TFT. The proposed pixel circuit can operate in two compensation modes for high‐luminance operation; and the black data insertion was introduced to improve the characteristics of moving images. The pixel circuit was designed for an 11.6″WXGA top‐emission AMOLED panel, and its non‐uniformity was estimated to be < 4% with a mobility compensation time of 1 μs.
Illumination normalisation method using Kolmogorov‐Nagumo‐based statistics for face recognition
Authors: Castillo L.E. , Cament L.A. , Galdames F.J. , Perez C.A.
Published: June 2014

Illumination compensation has proven to be crucial in many machine vision applications including face recognition. This is especially important in non‐controlled scenarios where face illumination is not homogeneous. An extension of the local normalisation (LN) method using Kolmogorov‐Nagumo‐based statistics to improve face recognition is proposed. The proposed method is a more general framework for illumination normalisation and it is shown that LN is a particular case of this framework. The proposed method using two different classifiers, PCA and local matching Gabor, on the standard face databases Extended Yale B, AR Face and Gray FERET is assessed. The method reached significantly better results than those previously published on the same databases.
Normalised adaptive linear element‐based control of single‐phase self excited induction generator feeding fluctuating loads
Authors: Kalla Ujjwal Kumar , Singh Bhim , Murthy S.S.
Published: June 2014

In this study, a new normalised adaline‐based control algorithm is proposed to control voltage source converter (VSC) used for voltage control and harmonics mitigation of two‐winding asymmetric single‐phase self excited induction generator (SEIG) feeding fluctuating linear and non‐linear loads. The proposed control algorithm is implemented on a digital signal processor (DSP). In the proposed SEIG system, a two‐winding asymmetric single‐phase SEIG is driven by a speed governor controlled diesel/biogas engine. The VSC is used for adjustable fundamental reactive current compensation of a two‐winding single‐phase SEIG for voltage control, and harmonics elimination of variety of loads. An insulated gate bipolar transistor‐based two‐leg VSC is connected at the point of common coupling. The proposed new control algorithm has many distinct advantages such as fast response which is highly desirable for fluctuating loads and fast convergence at all frequency components. The mathematical formulation of the proposed control algorithm is given and recorded test results of the SEIG system are presented to demonstrate the voltage control, harmonics mitigation and fast response of the algorithm. The proposed controller of single‐phase SEIG system is designed, developed and implemented on a DSP to validate the claims. A MATLAB simulation model of SEIG system with proposed controller is also developed and simulated results are presented along with the test results to validate the model developed.
Improved ac/ac choppers‐based voltage regulator designs
Authors: Khan Muhammad Mansoor , Rana Ahmad , Dong Fei
Published: June 2014

This paper proposes a robust design for the ac/ac chopper‐based voltage sag/swell compensation systems. This includes the design of a new buck–boost topology and the application of a robust switching scheme for a voltage compensator. The proposed circuit can operate in the buck or boost mode for both the sag and the swell compensations. A control scheme for a fast compensation is also proposed which is suitable for the ac/ac chopper‐based compensation system. Detailed analysis and verification through a simulation in the MATLAB are presented highlighting the advantages of the proposed technique. An experimental verification has also been performed by using a laboratory prototype system.
Reduced junction temperature control during low‐voltage ride‐through for single‐phase photovoltaic inverters
Authors: Yang Yongheng , Wang Huai , Blaabjerg Frede
Published: June 2014

Future photovoltaic (PV) inverters are expected to comply with more stringent grid codes and reliability requirements, especially when a high penetration degree is reached, and also to lower the cost of energy. A junction temperature control concept is proposed in this study for the switching devices in a single‐phase PV inverter in order to reduce the junction temperature stress, and thus to achieve improved reliability of a PV inverter. The thermal stresses of the switching devices are analysed during low‐voltage ride‐through operation with different levels of reactive power injection, allowing an optimal design of the proposed control scheme with controlled mean junction temperature and reduced junction temperature swings. The effectiveness of the control method in terms of both thermal performance and electrical performance is validated by the simulations and experiments, respectively. Both test results show that single‐phase PV inverters with the proposed control approach not only can support the grid voltage recovery in low‐voltage ride‐through operation but also can improve the overall reliability with a reduced junction temperature.
Low-temperature random matrix theory at the soft edge
Authors: Edelman Alan , Persson Per-Olof , Sutton Brian D.
Published: June 2014

“Low temperature” random matrix theory is the study of random eigenvalues as energy is removed. In standard notation, β is identified with inverse temperature, and low temperatures are achieved through the limit β → ∞. In this paper, we derive statistics for low-temperature random matrices at the “soft edge,” which describes the extreme eigenvalues for many random matrix distributions. Specifically, new asymptotics are found for the expected value and standard deviation of the general-β Tracy-Widom distribution. The new techniques utilize beta ensembles, stochastic differential operators, and Riccati diffusions. The asymptotics fit known high-temperature statistics curiously well and contribute to the larger program of general-β random matrix theory.
Ab initio investigation of electronic and vibrational contributions to linear and nonlinear dielectric properties of ice
Authors: Casassa S. , Baima J. , Mahmoud A. , Kirtman B.
Published: June 2014

Electronic and vibrational contributions to the static and dynamic (hyper)polarizability tensors of ice XI and model structures of ordinary hexagonal ice have been theoretically investigated. Calculations were carried out by the finite field nuclear relaxation method for periodic systems (FF-NR) recently implemented in the CRYSTAL code, using the coupled-perturbed Kohn-Sham approach (CPKS) for evaluating the required electronic properties. The effect of structure on the static electronic polarizabilities (dielectric constants) and second-hyperpolarizabilities is minimal. On the other hand, the vibrational contributions to the polarizabilities were found to be significant. A reliable evaluation of these (ionic) contributions allows one to discriminate amongst ice phases characterized by different degrees of proton-order, primarily through differences caused by librational motions. Transverse static and dynamic vibrational (hyper)polarizabilities were found by extrapolating calculations for slabs of increasing size, in order to eliminate substantial surface contributions.
Helicity of mean and turbulent flow with coherent structures in Rayleigh-Bénard convective cell
Authors: Eidelman A. , Elperin T. , Gluzman I. , Golbraikh E.
Published: June 2014

We present results of the study of a turbulent air flow with a large scale circulation in Rayleigh-Bénard rectangular convective cell with a heated bottom wall and a cooled top wall. Velocity fields were measured using Particle Image Velocimetry in two sets of mutually perpendicular planes parallel to the vertical walls of the cell. Experiments revealed the existence of the main roll, having a length scale of the order of the size of the cell, and elongated eddy rings adjacent to the bottom and top of the main roll. The mean horizontal velocity of the main roll and the mean vorticity of eddy rings are almost aligned in a large part of the flow. The helicity of the mean flow is quite high, and is the source of turbulent helicity. Since helicity of the mean flow and turbulence is quite large, the flow in Rayleigh-Bénard convective cell is well suited to study properties of helical turbulence. Spatial distribution of the turbulent kinetic energy is almost locally isotropic in the central region of the cell. Spectra and cross spectra of turbulent velocities reveal two distinct ranges in the inertial interval with the slopes close to −5 / 3 and −7 / 3. We believe that emergence of these two intervals is associated with energy and helicity cascades that affect turbulence. We also determined turbulent helicity using the measured velocity cross-spectra. We found that the magnitude of the length scale where the slope of the velocity spectra changes and the magnitude of the length scale defined as the ratio of turbulent energy to the helicity are approximately the same. The slopes of power law spectra of helicity in the intervals above and below the transition length scale are equal to −2 / 3 and −4 / 3, respectively. Remarkably, similar inertial sub-ranges in turbulent energy spectra were observed in various laboratory and geophysical turbulent flows.
A nine-dimensional ab initio global potential energy surface for the H2O+ + H2 → H3O+ + H reaction
Authors: Li Anyang , Guo Hua
Published: June 2014

An accurate full-dimensional global potential energy surface (PES) is developed for the title reaction. While the long-range interactions in the reactant asymptote are represented by an analytical expression, the interaction region of the PES is fit to more than 81 000 of ab initio points at the UCCSD(T)-F12b/AVTZ level using the permutation invariant polynomial neural network approach. Fully symmetric with respect to permutation of all four hydrogen atoms, the PES provides a faithful representation of the ab initio points, with a root mean square error of 1.8 meV or 15 cm−1. The reaction path for this exoergic reaction features an attractive and barrierless entrance channel, a submerged saddle point, a shallow H4O+ well, and a barrierless exit channel. The rate coefficients for the title reaction and kinetic isotope effect have been determined on this PES using quasi-classical trajectories, and they are in good agreement with available experimental data. It is further shown that the H2O+ rotational enhancement of reactivity observed experimentally can be traced to the submerged saddle point. Using our recently proposed Sudden Vector Projection model, we demonstrate that a rotational degree of freedom of the H2O+ reactant is strongly coupled with the reaction coordinate at this saddle point, thus unraveling the origin of the pronounced mode specificity in this reaction.
Phase transformation, improved ferroelectric and magnetic properties of (1 − x) BiFeO3–xPb(Zr0.52Ti0.48)O3 solid solutions
Authors: Sharma Subhash , Singh Vikash , Dwivedi R. K. , Ranjan Rajeev , Anshul Avneesh , Amritphale S. S. , Chandra Navin
Published: June 2014

The authors prepared (1 − x)BiFeO3 – (x)Pb(Zr0.52Ti0.48)O3 for x ≤ 0.30 by sol-gel method and investigated the material's structures, magnetic and electrical properties. Detailed Rietveld analysis of X-ray diffraction data revealed that the system retains distorted rhombohedral R3c structure for x ≤ 0.10 but transforms to monoclinic (Cc) structure for x > 0.10. Disappearance of some Raman modes corresponding to A1 modes and the decrease in the intensities of the remaining A1 modes with increasing x in the Raman spectra, which is a clear indication of structural modification and symmetry changes brought about by PZT doping. Enhanced magnetization with PZT doping content may be attributed to the gradual change and destruction in the spin cycloid structure of BiFeO3. The leakage current density at 3.5 kV/cm was reduced by approximately three orders of magnitude by doping PZT (x = 0.30), compared with BFO ceramics.
Temporal cross-correlation asymmetry and departure from equilibrium in a bistable chemical system
Authors: Bianca C. , Lemarchand A.
Published: June 2014

This paper aims at determining sustained reaction fluxes in a nonlinear chemical system driven in a nonequilibrium steady state. The method relies on the computation of cross-correlation functions for the internal fluctuations of chemical species concentrations. By employing Langevin-type equations, we derive approximate analytical formulas for the cross-correlation functions associated with nonlinear dynamics. Kinetic Monte Carlo simulations of the chemical master equation are performed in order to check the validity of the Langevin equations for a bistable chemical system. The two approaches are found in excellent agreement, except for critical parameter values where the bifurcation between monostability and bistability occurs. From the theoretical point of view, the results imply that the behavior of cross-correlation functions cannot be exploited to measure sustained reaction fluxes in a specific nonlinear system without the prior knowledge of the associated chemical mechanism and the rate constants.
Effective heat conduction in hybrid sphere & wire nanodispersions
Authors: Behrang A. , Grmela M. , Dubois C. , Turenne S. , Lafleur P. G. , Lebon G.
Published: June 2014

Heat conductivity of dispersions can be modified by varying shapes of dispersed particles and also by making hybrid dispersions containing particles of different shapes and sizes. Spheres and their agglomerates that we have investigated previously are replaced in this paper by spheres and wires. The method used to derive the formulas for the overall effective heat conductivity is based on the Maxwell homogenization (adapted to hybrid dispersions) followed by a mesoscopic analysis in which heat transfer is regarded as transport of phonons. The mesoscopic formulation provides then also a setting for investigation the role of particle-matrix nanoscale interfaces.
Ionization of N2 in radio-frequent electric field
Authors: Popović M. P. , Vojnović M. M. , Aoneas M. M. , Ristić M. M. , Vićić M. D. , Poparić G. B.
Published: June 2014

Rate coefficients for the electron impact ionization of the N2 molecule are calculated in non-equilibrium conditions in the presence of time-dependent electric field. A Monte Carlo simulation has been developed in order to determine non-equilibrium electron energy distribution functions within one period of the radio-frequent (RF) electric field. By using these distribution functions, rate coefficients for ionization of the N2 molecule have been obtained time resolved within one period in the frequency range from 13.56 up to 500 MHz, at effective reduced electric field values up to 700 Td. This work presents an insight into the temporal characteristics of ionizing process and provides the ionization rate coefficients that can be of great use for correct implementation in modeling RF plasma discharges. A behavior of rate coefficients under the influence of magnitude and frequency of the fields was studied separately revealing some interesting features in time dependence.
Two-dimensional numerical study of two counter-propagating helium plasma jets in air at atmospheric pressure
Authors: Yan Wen , Liu Fucheng , Sang Chaofeng , Wang Dezhen
Published: June 2014

In this paper, a computational study of two counter-propagating helium plasma jets in ambient air is presented. A two-dimensional fluid model is applied to investigate the physical processes of the two plasma jets interaction (PJI) driven by equal and unequal voltages, respectively. In all studied cases, the PJI results in a decrease of both plasma bullets propagation velocity. When the two plasma jets are driven by equal voltages, they never merge but rather approach each other around the middle of the gas gap at a minimum approach distance, and the minimal distance decreases with the increase of both the applied voltages and initial electron density, but increases with the increase of the relative permittivity. When the two plasma jets are driven by unequal voltages, we observe the two plasma jets will merge at the position away from the middle of the gas gap. The effect of applied voltage difference on the PJI is also studied.
Distinct optical properties of relativistically degenerate matter
Authors: Akbari-Moghanjoughi M.
Published: June 2014

In this paper, we use the collisional quantum magnetohydrodynamic (CQMHD) model to derive the transverse dielectric function of a relativistically degenerate electron fluid and investigate various optical parameters, such as the complex refractive index, the reflection and absorption coefficients, the skin-depth and optical conductivity. In this model we take into accounts effects of many parameters such as the atomic-number of the constituent ions, the electron exchange, electron diffraction effect and the electron-ion collisions. Study of the optical parameters in the solid-density, the warm-dense-matter, the big-planetary core, and the compact star number-density regimes reveals that there are distinct differences between optical characteristics of the latter and the former cases due to the fundamental effects of the relativistic degeneracy and other quantum mechanisms. It is found that in the relativistic degeneracy plasma regime, such as found in white-dwarfs and neutron star crusts, matter possess a much sharper and well-defined step-like reflection edge beyond the x-ray electromagnetic spectrum, including some part of gamma-ray frequencies. It is also remarked that the magnetic field intensity only significantly affects the plasma reflectivity in the lower number-density regime, rather than the high density limit. Current investigation confirms the profound effect of relativistic degeneracy on optical characteristics of matter and can provide an important plasma diagnostic tool for studying the physical processes within the wide scope of quantum plasma regimes be it the solid-density, inertial-confined, or astrophysical compact stars.
Generation of high-energy-density ion bunches by ultraintense laser-cone-target interaction
Authors: Yang X. H. , Yu W. , Xu H. , Zhuo H. B. , Ma Y. Y. , Zou D. B. , Yu T. P. , Ge Z. Y. , Yin Y. , Shao F. Q. , Borghesi M.
Published: June 2014

A scheme in which carbon ion bunches are accelerated to a high energy and density by a laser pulse (∼1021 W/cm2) irradiating cone targets is proposed and investigated using particle-in-cell simulations. The laser pulse is focused by the cone and drives forward an ultrathin foil located at the cone's tip. In the course of the work, best results were obtained employing target configurations combining a low-Z cone with a multispecies foil transversely shaped to match the laser intensity profile.
Numerical and simulation study of terahertz radiation generation by laser pulses propagating in the extraordinary mode in magnetized plasma
Authors: Jha Pallavi , Kumar Verma Nirmal
Published: June 2014

A one-dimensional numerical model for studying terahertz radiation generation by intense laser pulses propagating, in the extraordinary mode, through magnetized plasma has been presented. The direction of the static external magnetic field is perpendicular to the polarization as well as propagation direction of the laser pulse. A transverse electromagnetic wave with frequency in the terahertz range is generated due to the presence of the magnetic field. Further, two-dimensional simulations using XOOPIC code show that the THz fields generated in plasma are transmitted into vacuum. The fields obtained via simulation study are found to be compatible with those obtained from the numerical model.
Liquid contact resonance atomic force microscopy via experimental reconstruction of the hydrodynamic function
Authors: Tung Ryan C. , Killgore Jason P. , Hurley Donna C.
Published: June 2014

We present a method to correct for surface-coupled inertial and viscous fluid loading forces in contact resonance (CR) atomic force microscopy (AFM) experiments performed in liquid. Based on analytical hydrodynamic theory, the method relies on experimental measurements of the AFM cantilever's free resonance peaks near the sample surface. The free resonance frequencies and quality factors in both air and liquid allow reconstruction of a continuous hydrodynamic function that can be used to adjust the CR data in liquid. Validation experiments utilizing thermally excited free and in-contact spectra were performed to assess the accuracy of our approach. Results show that the method recovers the air frequency values within approximately 6%. Knowledge of fluid loading forces allows current CR analysis techniques formulated for use in air and vacuum environments to be applied to liquid environments. Our technique greatly extends the range of measurement environments available to CR-AFM.
Local nonlinear rf forces in inhomogeneous magnetized plasmas
Authors: Chen Jiale , Gao Zhe
Published: June 2014

The local nonlinear forces induced by radio frequency (rf) waves are derived in inhomogeneous magnetized plasmas, where the inhomogeneity exists in the rf fields, in the static magnetic field as well as in the equilibrium density and temperature. The local parallel force is completely resonant, but a novel component dependent on those inhomogeneities is obtained as the result of the inhomogeneous transport of parallel resonant-absorbed momentum by the nonlinear perpendicular drift flux. In the local poloidal force, the component induced by the inhomogeneity of rf power absorption is also confirmed and it can be recognized as the residual effect from the incomplete cancellation between the rate of the diamagnetic poloidal momentum gain and the Lorentz force due to the radial diffusion-like flux. The compact expression for radial force is also obtained for the first time, whose nonresonant component is expressed as the sum of the ponderomotive force on particles and the gradients of the nonresonant perpendicular pressure and of the nonresonant momentum flux due to the finite temperature effect. Numerical calculations in a 1-D slab model show that the resonant component dependent on the inhomogeneities may be significant when the ion absorption dominates the resonant wave-particle interaction. A quantitative estimation shows that the novel component in the parallel force is important to understand the experiments of the ion-cyclotron-frequency mode-conversion flow drive.
Facile functionalization of Fe2O3 nanoparticles to induce inherent photoluminescence and excellent photocatalytic activity
Authors: Pal Monalisa , Rakshit Rupali , Mandal Kalyan
Published: June 2014

Herein, we report the emergence of intrinsic multicolor photoluminescence in Fe2O3 nanoparticles (NPs) ranging from blue, cyan, to green, upon facile functionalization and further surface modification with a small organic ligand, Na-tartrate. Moreover, we have found unprecedented photocatalytic property of the functionalized Fe2O3 NPs in the degradation of a model water-contaminant. Meticulous investigation through UV-visible absorption and fluorescence study along with theoretical support from literature unfolds that ligand-to-metal charge-transfer transition from the tartrate ligand to the lowest unoccupied energy level of Fe3+ of the NPs and d−d transitions centered over Fe3+ ions in the NPs play the key role in the emergence of multiple photoluminescence from the ligand functionalized Fe2O3 NPs. Moreover, vibrating sample magnetometry measurements demonstrate that the surface modification changes the magnetic behaviour of Fe2O3 NPs upon functionalization. We believe that the great potential of our versatile, ferromagnetic, multicolor photoluminescent Fe2O3 NPs would stimulate the development of numerous opportunities toward their biological and technological applications.
Note: Simulation and test of a strip source electron gun
Authors: Iqbal Munawar , Islam G. U. , Misbah I. , Iqbal O. , Zhou Z.
Published: June 2014

We present simulation and test of an indirectly heated strip source electron beam gun assembly using Stanford Linear Accelerator Center (SLAC) electron beam trajectory program. The beam is now sharply focused with 3.04 mm diameter in the post anode region at 15.9 mm. The measured emission current and emission density were 1.12 A and 1.15 A/cm2, respectively, that corresponds to power density of 11.5 kW/cm2, at 10 kV acceleration potential. The simulated results were compared with then and now experiments and found in agreement. The gun is without any biasing, electrostatic and magnetic fields; hence simple and inexpensive. Moreover, it is now more powerful and is useful for accelerators technology due to high emission and low emittance parameters.
Electric field-induced magnetic switching in Mn:ZnO film
Authors: Ren S. X. , Sun G. W. , Zhao J. , Dong J. Y. , Wei Y. , Ma Z. C. , Zhao X. , Chen W.
Published: June 2014

A large magnetic modulation, accompanied by stable bipolar resistive switching (RS) behavior, was observed in a Mn:ZnO film by applying a reversible electric field. A significant enhancement of the ferromagnetism of the film, to about five times larger than that in the initial (as-grown) state (IS), was obtained by switching the film into the low resistance state. X-ray photoelectron spectroscopy demonstrated the existence of abundant oxygen vacancies in the IS of the film. We suggest that this electric field-induced magnetic switching effect originates with the migration and redistribution of oxygen vacancies during RS. Our work indicates that electric switching is an effective and simple method to increase the ferromagnetism of diluted magnetic oxide films. This provides a promising direction for research in spintronic devices.
Diffractive intermediate layer enables broadband light trapping for high efficiency ultrathin c-Si tandem cells
Authors: Li Guijun , Ho Jacob Y. L. , Li He , Kwok Hoi-Sing
Published: June 2014

Light management through the intermediate reflector in the tandem cell configuration is of great practical importance for achieving high stable efficiency and also low cost production. So far, however, the intermediate reflectors employed currently are mainly focused on the light absorption enhancement of the top cell. Here, we present a diffractive intermediate layer that allows for light trapping over a broadband wavelength for the ultrathin c-Si tandem solar cell. Compared with the standard intermediate reflector, this nanoscale architectural intermediate layer results in a 35% and 21% remarkable enhancement of the light absorption in the top (400–800 nm) and bottom (800–1100 nm) cells simultaneously, and ultrathin c-Si tandem cells with impressive conversion efficiency of 13.3% are made on the glass substrate.
Plasmon induced transparency in a surface plasmon polariton waveguide with a comb line slot and rectangle cavity
Authors: Zhang Zhengren , Zhang Liwei , Li Hongqiang , Chen Hong
Published: June 2014

The phenomenon of electromagnetically induced transparency (EIT) is demonstrated in a surface plasmon polariton waveguide at infrared frequencies. The comb line slot and rectangle cavity are placed inside one of the metallic claddings, and their coupling intensities among them are utilized to obtain bright and dark states. The destructive interference between the bright and dark states leads to an EIT-like transmission spectrum of the waveguide. The induced transparency peak can be manipulated by adjusting the coupling distance between the bright and dark states. Finally, the influence of Joule loss on the EIT-like effect is investigated. It is found that the EIT-like transmission contrast is sensitive to the variation in the metallic damping factor.
Experimental demonstration of hot-carrier photo-current in an InGaAs quantum well solar cell
Authors: Hirst L. C. , Walters R. J. , Führer M. F. , Ekins-Daukes N. J.
Published: June 2014

An unambiguous observation of hot-carrier photocurrent from an InGaAs single quantum well solar cell is reported. Simultaneous photo-current and photoluminescence measurements were performed for incident power density 0.04–3 kW cm−2, lattice temperature 10 K, and forward bias 1.2 V. An order of magnitude photocurrent increase was observed for non-equilibrium hot-carrier temperatures >35 K. This photocurrent activation temperature is consistent with that of equilibrium carriers in a lattice at elevated temperature. The observed hot-carrier photo-current is extracted from the well over an energy selective GaAs barrier, thus integrating two essential components of a hot-carrier solar cell: a hot-carrier absorber and an energy selective contact.
Discrete charge states in nanowire flash memory with multiple Ta2O5 charge-trapping stacks
Authors: Zhu Hao , Bonevich John E. , Li Haitao , Richter Curt A. , Yuan Hui , Kirillov Oleg , Li Qiliang
Published: June 2014

In this work, multi-bit flash-like memory cell based on Si nanowire field-effect transistor and multiple Ta2O5 charge-trapping stacks have been fabricated and fully characterized. The memory cells exhibited staircase, discrete charged states at small gate voltages. Such discrete multi-bit on one memory cell is attractive for high memory density. These non-volatile memory devices exhibited fast programming/erasing speed, excellent retention, and endurance, indicating the advantages of integrating the multilayer of charge-storage stacks on the nanowire channel. Such high-performance flash-like non-volatile memory can be integrated into the microprocessor chip as the local memory which requires high density and good endurance.
A mystery caller evaluation of emergency contraception supply practices in community pharmacies in Victoria, Australia
Authors: Hussainy Safeera Y. , Stewart Kay , Pham My-Phuong
Published: June 2014

The aim of this study was to determine supply practices of Victorian community pharmacies in relation to the emergency contraceptive pill (ECP), following release of an updated guideline by the Pharmaceutical Society of Australia. Telephone call scripts were developed for three scenarios in which the ECP was requested: outside the licensed 72-h time frame (Scenario 1); by a woman under 16 years (Scenario 2); and for future use (Scenario 3). From 1222 pharmacies, 515 were randomly selected and allocated into three groups: 177 to Scenario 1 and 169 to each of Scenarios 2 and 3. Pharmacists’ responses were categorised as ‘yes’, ‘no’ or ‘ambiguous’ and descriptive statistics were calculated. The results are as follows. Scenario 1: over half (55.4%; 92/166) declined supply and most referred to the doctor, citing the time frame or the ECP as no longer being effective reasons. Decreased effectiveness was readily discussed among those willing to supply. Scenario 2: more than half (53.9%, 89/165) agreed to supply, assessing the request against eligibility criteria outlined in the guideline; however, 5.6% (5/89) were only willing if the woman obtained a doctor’s prescription or recommendation. Scenario 3: less than half (40.5%; 66/163) declined supply, mainly due to no therapeutic need. Only four respondents willing to give the ECP knew that supply was bona fide. In conclusion, pharmacists’ practices are variable and not always in line with the recommendations of the Pharmaceutical Society of Australia guideline. Pharmacists’ awareness of the guideline needs to be raised so women can unobtrusively access the ECP.
An unusually powerful mode of low-frequency sound interference due to defective hair bundles of the auditory outer hair cells
Authors: Kamiya Kazusaku , Michel Vincent , Giraudet Fabrice , Riederer Brigitte , Foucher Isabelle , Papal Samantha , Perfettini Isabelle , Le Gal Sébastien , Verpy Elisabeth , Xia Weiliang , Seidler Ursula , Georgescu Maria-Magdalena , Avan Paul , El-Amraoui Aziz , Petit Christine
Published: June 2014

Significance

We show that the submembrane scaffold protein Nherf1 is necessary for correct shaping of outer hair cells stereocilia bundles in the basal cochlea. The mild elevation of hearing thresholds (22–35 dB) of
Nherf1

−/−

mice at high frequencies was inconsistent with the loss of outer hair cell functionality in the basal cochlea. Responses of
Nherf1

−/−

mice to high-frequency test tones were masked by tones displaying inordinate characteristics in frequency, level, and growth response. We suggest that in
Nherf1

−/−

mice, high-frequency vibrations are detected in the unaffected apical cochlea, thus accounting for the powerful masking effect of low-frequency sound. This source of misleading evaluation of high-frequency hearing thresholds and hypervulnerability to low-frequency sound interference should be systematically sought in hearing-impaired patients.
What do adolescents think and feel about the different female subtypes? An application of the stereotype content model (SCM) / ¿Qué sienten y piensan los/las adolescentes acerca de diferentes subtipos de mujer? Una aplicación del modelo del contenido de los estereotipos
Authors: Cuadrado-Guirado Isabel , López-Turrillo Esther
Published: June 2014

Women continue to face discrimination due to stereotypes that place them at a disadvantage compared to men. However, not all women are stereotyped alike; instead, they are categorized into three main subtypes: traditional women (e.g., housewives), non-traditional women (e.g., career women) and sexy women. This study applies the stereotype content model (SCM) to examine how a sample of adolescents perceives the three subtypes of women in terms of status and competition, the content of the stereotypes and the emotions they feel towards the subtypes. The sample consisted of 221 adolescents, which was reduced to 163 participants (53.7% girls) between the ages of 12 and 18. Results show that sexy women are the most undervalued of the three. Likewise, housewives and career women are perceived more positively than in previous research with the adult population.
Models of disability, ideas of justice, and the challenge of full participation
Authors: Griffo Giampiero
Published: June 2014

The definitions of disability adopted in the UN Convention on the Rights of Persons with Disabilities (CRPD) necessitate an important change in the way disability is assessed and introduce a new idea of justice in relation to persons with disabilities. The article starts by reviewing the various ‘models of disability’ prevailing in the past and the respective ideas of justice underlying them. The charity model, for instance, was rooted in ideas of divine justice and human beneficence, where care for the disabled led in practice to their being segregated from the rest of society, while the medical model saw justice in terms of treatments or compensations for individual pathologies rather than of positive enablement for active living. The CRPD overturns these models and the related conceptions of justice by emphasising society's obligations towards persons with disabilities and, above all, their human right to full inclusion and participation in society. The key concepts are empowerment and capability. In Italy these concepts and this new conception of justice have started to be applied by the Osservatorio nazionale sulla condizione delle persone con disabilità, the body created to monitor the effective application of the CRPD in Italy, and they are included in the two-year action programme on disability, approved by the Italian government in October 2013.
A family affair: the depiction of disability in contemporary mainstream Italian cinema
Authors: Hill Sarah Patricia
Published: June 2014

Despite a grim history of marginalisation and oppression of people with disabilities, Italy has been praised for its early de-institutionalisation and attempts to adopt a more inclusive educational approach. Do recent Italian films provide evidence that these approaches have made a difference to how disability is made visible on film, or is it still depicted largely as an individual or family affair rather than a societal or political issue? Over the last decades, numerous scholars in disability studies have argued that cinema is an important location for understanding the formation of ideas about disability and have analysed the representation of people with disabilities in film, particularly in mainstream cinema. Moving from a focus on stereotypes and the description of ‘positive’ and ‘negative’ portrayals of disability, more recent scholarship examines filmic images of people with impairments in the light of a conception of disability termed by Snyder and Mitchell a ‘constructed social space’. Yet this extensive body of work has had limited impact in Italy in disability studies and film studies. This article applies it to some contemporary Italian films, considering the ways in which they represent disability and focusing in particular on Andrea Molaioli'sLa ragazza del lago(2007).