bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensitivity‐based optimal shape design of induction‐heating devices
Authors: Di Barba Paolo , Dughiero Fabrizio , Forzan Michele , Sieni Elisabetta
Published: March 2015

A design of experiment (DOE) strategy applied to multi‐objective optimisation is proposed in order to evaluate the influence of design variables variations to optimised quantities. A secondary objective function is the sensitivity of a primary objective function to design variable variations evaluated by means of DOE strategy. The optimisation problem includes also a third objective function that considers device constraint because of technological limitations on power generator. The proposed case study deals with the design of an electromagnetic device that will be used to carry out laboratory experiments on magneto‐fluid hyperthermia, that is, a clinic treatment for cancer cure. The induction system is designed to apply a controlled time‐varying magnetic field to biological cells, cultured in Petri dish and mixed with magnetic nanoparticles. This study presents an original cost‐effective method of multi‐objective design optimisation taking into account design uncertainties.
Catalyst- and Solvent-Free Rapid Addition of Secondary Phosphine Chalcogenides to Aldehydes: Another Click Chemistry
Authors: Gusarova Nina , Ivanova Nina , Volkov Pavel , Khrapova Kseniya , Larina Luydmila , Smirnov Vladimir , Borodina Tatyana , Trofimov Boris
Published: March 2015

An efficient catalyst- and solvent-free method for the synthesis of tertiary α-hydroxyphosphine chalcogenides, via the almost quantitative addition of secondary phosphine chalcogenides to diverse aldehydes under mild conditions (20–52 °C, from 10 min to 5 h), is reported.
Inhomogeneous broadening of optically detected magnetic resonance of the ensembles of nitrogen-vacancy centers in diamond by interstitial carbon atoms
Authors: Levchenko A. O. , Vasil'ev V. V. , Zibrov S. A. , Zibrov A. S. , Sivak A. V. , Fedotov I. V.
Published: March 2015

We study the impact of the negatively charged nitrogen-vacancy (NV–) center density on the lattice strain resulting in the splitting of the optically detected magnetic resonance of HPHT diamond. A simple model, taking into account the presence of the interstitial carbon atoms, acting like a wedge force on the crystal lattice, explains the broadening and splitting of the optically detected magnetic resonance of the ensemble of NV– centers at densities within the range of 1013 ÷ 1014 cm−3. This model uses a complete generalized spin Hamiltonian, takes into account the strain-effect of each center in the ensemble and gives good agreement with experimental data.
Evolution of field line helicity during magnetic reconnection
Authors: Russell A. J. B. , Yeates A. R. , Hornig G. , Wilmot-Smith A. L.
Published: March 2015

We investigate the evolution of field line helicity for magnetic fields that connect two boundaries without null points, with emphasis on localized finite-B magnetic reconnection. Total (relative) magnetic helicity is already recognized as an important topological constraint on magnetohydrodynamic processes. Field line helicity offers further advantages because it preserves all topological information and can distinguish between different magnetic fields with the same total helicity. Magnetic reconnection changes field connectivity and field line helicity reflects these changes; the goal of this paper is to characterize that evolution. We start by deriving the evolution equation for field line helicity and examining its terms, also obtaining a simplified form for cases where dynamics are localized within the domain. The main result, which we support using kinematic examples, is that during localized reconnection in a complex magnetic field, the evolution of field line helicity is dominated by a work-like term that is evaluated at the field line endpoints, namely, the scalar product of the generalized field line velocity and the vector potential. Furthermore, the flux integral of this term over certain areas is very small compared to the integral of the unsigned quantity, which indicates that changes of field line helicity happen in a well-organized pairwise manner. It follows that reconnection is very efficient at redistributing helicity in complex magnetic fields despite having little effect on the total helicity.
Surface hopping outperforms secular Redfield theory when reorganization energies range from small to moderate (and nuclei are classical)
Authors: Landry Brian R. , Subotnik Joseph E.
Published: March 2015

We evaluate the accuracy of Tully’s surface hopping algorithm for the spin-boson model in the limit of small to moderate reorganization energy. We calculate transition rates between diabatic surfaces in the exciton basis and compare against exact results from the hierarchical equations of motion; we also compare against approximate rates from the secular Redfield equation and Ehrenfest dynamics. We show that decoherence-corrected surface hopping performs very well in this regime, agreeing with secular Redfield theory for very weak system-bath coupling and outperforming secular Redfield theory for moderate system-bath coupling. Surface hopping can also be extended beyond the Markovian limits of standard Redfield theory. Given previous work [B. R. Landry and J. E. Subotnik, J. Chem. Phys. 137, 22A513 (2012)] that establishes the accuracy of decoherence-corrected surface-hopping in the Marcus regime, this work suggests that surface hopping may well have a very wide range of applicability.
NMR diffusion-encoding with axial symmetry and variable anisotropy: Distinguishing between prolate and oblate microscopic diffusion tensors with unknown orientation distribution
Authors: Eriksson Stefanie , Lasič Samo , Nilsson Markus , Westin Carl-Fredrik , Topgaard Daniel
Published: March 2015

We introduce a nuclear magnetic resonance method for quantifying the shape of axially symmetric microscopic diffusion tensors in terms of a new diffusion anisotropy metric, DΔ, which has unique values for oblate, spherical, and prolate tensor shapes. The pulse sequence includes a series of equal-amplitude magnetic field gradient pulse pairs, the directions of which are tailored to give an axially symmetric diffusion-encoding tensor b with variable anisotropy bΔ. Averaging of data acquired for a range of orientations of the symmetry axis of the tensor b renders the method insensitive to the orientation distribution function of the microscopic diffusion tensors. Proof-of-principle experiments are performed on water in polydomain lyotropic liquid crystals with geometries that give rise to microscopic diffusion tensors with oblate, spherical, and prolate shapes. The method could be useful for characterizing the geometry of fluid-filled compartments in porous solids, soft matter, and biological tissues.
Potential energy surfaces for the HBr+ + CO2 → Br + HOCO+ reaction in the HBr+ 2Π3/2 and 2Π1/2 spin-orbit states
Authors: Sun Rui , Granucci Giovanni , Paul Amit K. , Siebert Matthew , Liang Hongliang J. , Cheong Grace , Hase William L. , Persico Maurizio
Published: March 2015

Quantum mechanical (QM) + molecular mechanics (MM) models are developed to represent potential energy surfaces (PESs) for the HBr+ + CO2 → Br + HOCO+ reaction with HBr+ in the 2Π3/2 and 2Π1/2 spin-orbit states. The QM component is the spin-free PES and spin-orbit coupling for each state is represented by a MM-like analytic potential fit to spin-orbit electronic structure calculations. Coupled-cluster single double and perturbative triple excitation (CCSD(T)) calculations are performed to obtain “benchmark” reaction energies without spin-orbit coupling. With zero-point energies removed, the “experimental” reaction energy is 44 ± 5 meV for HBr+(2Π3/2) + CO2 → Br(2P3/2) + HOCO+, while the CCSD(T) value with spin-orbit effects included is 87 meV. Electronic structure calculations were performed to determine properties of the BrHOCO+ reaction intermediate and [HBr⋯OCO]+ van der Waals intermediate. The results of different electronic structure methods were compared with those obtained with CCSD(T), and UMP2/cc-pVTZ/PP was found to be a practical and accurate QM method to use in QM/MM direct dynamics simulations. The spin-orbit coupling calculations show that the spin-free QM PES gives a quite good representation of the shape of the PES originated by 2Π3/2HBr+. This is also the case for the reactant region of the PES for 2Π1/2 HBr+, but spin-orbit coupling effects are important for the exit-channel region of this PES. A MM model was developed to represent these effects, which were combined with the spin-free QM PES.
Mechanism of the Cassie-Wenzel transition via the atomistic and continuum string methods
Authors: Giacomello Alberto , Meloni Simone , Müller Marcus , Casciola Carlo Massimo
Published: March 2015

The string method is a general and flexible strategy to compute the most probable transition path for an activated process (rare event). We apply here the atomistic string method in the density field to the Cassie-Wenzel transition, a central problem in the field of superhydrophobicity. We discuss in detail the mechanism of wetting of a submerged hydrophobic cavity of nanometer size and its dependence on the geometry of the cavity. Furthermore, we analyze the algorithmic analogies between the continuum “interface” string method and CREaM [Giacomello et al., Phys. Rev. Lett. 109, 226102 (2012)], a method inspired by the string that allows for a faster and simpler computation of the mechanism and of the free-energy profiles of the wetting process.
Rarefaction-singular shock dynamics for conserved volume gravity driven particle-laden thin film
Authors: Wang L. , Mavromoustaki A. , Bertozzi A. L. , Urdaneta G. , Huang K.
Published: March 2015

We employ a recently proposed model [Murisic et al., “Dynamics of particle settling and resuspension in viscous liquids,” J. Fluid. Mech. 717, 203–231 (2013)] to study a finite-volume, particle-laden thin film flowing under gravity on an incline. For negatively buoyant particles with concentration above a critical value and buoyant particles, the particles accumulate at the front of the flow forming a particle-rich ridge, whose similarity solution is of the rarefaction-singular shock type. We investigate the structure in detail and find that the particle/fluid front advances linearly to the leading order with time to the one-third power as predicted by the Huppert solution [H. E. Huppert, “Flow and instability of a viscous current down a slope,” Nature 300, 427–419 (1982)] for clear fluid (i.e., in the absence of particles). We also explore a deviation from this law when the particle concentration is high. Several experiments are carried out with both buoyant and negatively buoyant particles whose results qualitatively agree with the theoretics.
Parametric study of the damage ring pattern in fused silica induced by multiple longitudinal modes laser pulses
Authors: Chambonneau M. , Grua P. , Rullier J.-L. , Natoli J.-Y. , Lamaignère L.
Published: March 2015

With the use of multiple longitudinal modes nanosecond laser pulses at 1064 nm, laser damage sites at the exit surface of fused silica clearly and systematically exhibit ring patterns. It has been shown in our previous works that the apparent chronology of rings was closely related to the temporal shape of the laser pulses. This particular correspondence had suggested an explanation of the ring morphology formation based on the displacement of an ionization front in the surrounding air. To provide a former basis for this hypothesis and deeper understanding of ring pattern formation, additional experiments have been performed. First, the impact of fluence has been investigated, revealing that a wide variety of damage sites are produced within a very narrow fluence range; this fact involves the chronology of appearance of a surface plasma during the laser pulse. The sizes of the damage sites are proportional to the fluence of their expansion occurring between the beginning of the plasma and the end of the laser pulse. Second, specific experiments have been carried out at different angles of incidence, resulting in egg-shaped patterns rather than circular ones. This behavior can be explained by our previous hypothesis of creation of a plasma in air, its expansion being tightly conditioned by the illumination angle. This series of experiments, in which the angle of incidence is varied up to 80°, permits us to link quantitatively the working hypothesis of ionization front propagation with theoretical hydrodynamics modeling.
In-situ ellipsometric characterization of the growth of porous anisotropic nanocrystalline ZnO layers
Authors: Laha P. , Nazarkin M. Y. , Volkova A. V. , Simunin M. M. , Terryn H. , Gavrilov S. A. , Ustarroz J.
Published: March 2015

ZnO films have increasingly been in the spotlight due to their largely varied electro-physical and optical properties. For several applications, porous anisotropic nanocrystalline layers are especially interesting. To study the growth kinetics of such films during different fabrication processes, a powerful non-destructive in-situ technique is required. In this work, both ex-situ and in-situ spectroscopic ellipsometry are used along with advanced modelling techniques that are able to take both the anisotropy and the porosity of the films into account. Scanning electron microscopy, along with nitrogen absorption methods for measuring porosity, validated the ellipsometric data and proposed model. The film, grown by chemical bath deposition, was monitored from around 700 to 1800 nm in thickness. This same principle can now be used to monitor any other porous and/or anisotropic structure in an effective in-situ manner, e.g., growth of porous anodic aluminium oxides, nano-porous silica films, etc.
Effects of polymethylmethacrylate-transfer residues on the growth of organic semiconductor molecules on chemical vapor deposited graphene
Authors: Kratzer Markus , Bayer Bernhard C. , Kidambi Piran R. , Matković Aleksandar , Gajić Radoš , Cabrero-Vilatela Andrea , Weatherup Robert S. , Hofmann Stephan , Teichert Christian
Published: March 2015

Scalably grown and transferred graphene is a highly promising material for organic electronic applications, but controlled interfacing of graphene thereby remains a key challenge. Here, we study the growth characteristics of the important organic semiconductor molecule para-hexaphenyl (6P) on chemical vapor deposited graphene that has been transferred with polymethylmethacrylate (PMMA) onto oxidized Si wafer supports. A particular focus is on the influence of PMMA residual contamination, which we systematically reduce by H2 annealing prior to 6P deposition. We find that 6P grows in a flat-lying needle-type morphology, surprisingly independent of the level of PMMA residue and of graphene defects. Wrinkles in the graphene typically act as preferential nucleation centers. Residual PMMA does however limit the length of the resulting 6P needles by restricting molecular diffusion/attachment. We discuss the implications for organic device fabrication, with particular regard to contamination and defect tolerance.
Parallel scalability of Hartree–Fock calculations
Authors: Chow Edmond , Liu Xing , Smelyanskiy Mikhail , Hammond Jeff R.
Published: March 2015

Quantum chemistry is increasingly performed using large cluster computers consisting of multiple interconnected nodes. For a fixed molecular problem, the efficiency of a calculation usually decreases as more nodes are used, due to the cost of communication between the nodes. This paper empirically investigates the parallel scalability of Hartree–Fock calculations. The construction of the Fock matrix and the density matrix calculation are analyzed separately. For the former, we use a parallelization of Fock matrix construction based on a static partitioning of work followed by a work stealing phase. For the latter, we use density matrix purification from the linear scaling methods literature, but without using sparsity. When using large numbers of nodes for moderately sized problems, density matrix computations are network-bandwidth bound, making purification methods potentially faster than eigendecomposition methods.
Atmospheric pressure barrier discharge at high temperature: Diagnostics and carbon nanotubes deposition
Authors: Eliáš M. , Kloc P. , Jašek O. , Mazánková V. , Trunec D. , Hrdý R. , Zajíčková L.
Published: March 2015

Atmospheric pressure dielectric barrier discharge (DBD) in Ar/H2 gas feed with C2H2 or CH4 admixture was studied at room and high temperature of 680 °C by plasma diagnostics (electrical measurements, fast camera imaging, and optical emission spectroscopy). It was shown that filamentary DBD in pure Ar or Ar/H2 can be converted into homogeneous discharge by an acetylene admixture. Fast intensified charge-coupled device (ICCD) camera proved that this homogeneous discharge is an atmospheric pressure glow discharge (APGD) at room temperature whereas at high temperature the discharge mode switches at every half-period between APGD and atmospheric pressure Townsend discharge. The high temperature discharges (610–710 °C) in Ar/H2/C2H2 and Ar/H2/CH4 were also investigated with respect to a surface bound deposition of carbon nanotubes using 5 nm thick iron layer as a catalyst. CNTs were deposited without any dedicated catalyst pretreatment phase. The quality of CNTs, namely, their density, vertical alignment, and width of the diameter distribution, was better for the C2H2 gas feed and higher temperatures.
Recent progress of magnetocaloric effect and magnetic refrigerant materials of Mn compounds (invited)
Authors: Wada H. , Takahara T. , Katagiri K. , Ohnishi T. , Soejima K. , Yamashita K.
Published: March 2015

Magnetocaloric and related properties of Ru and Ni substituted (MnFe)2(PSi) are presented. It is found that Ru and Ni are effective doping elements to reduce the thermal hysteresis of (MnFe)2(PSi). The origin of the thermal hysteresis is discussed on the basis of a thermodynamic model. It is shown that the elastic energy is responsible for the thermal hysteresis. We also show recent developments of the production process of Mn compounds in an industrial scale.
Core turbulence behavior moving from ion-temperature-gradient regime towards trapped-electron-mode regime in the ASDEX Upgrade tokamak and comparison with gyrokinetic simulation
Authors: Happel T. , Navarro A. Bañón , Conway G. D. , Angioni C. , Bernert M. , Dunne M. , Fable E. , Geiger B. , Görler T. , Jenko F. , McDermott R. M. , Ryter F. , Stroth U. ,   the ASDEX Upgrade Team
Published: March 2015

Additional electron cyclotron resonance heating (ECRH) is used in an ion-temperature-gradient instability dominated regime to increase R/LTe in order to approach the trapped-electron-mode instability regime. The radial ECRH deposition location determines to a large degree the effect on R/LTe. Accompanying scale-selective turbulence measurements at perpendicular wavenumbers between k⊥ = 4–18 cm−1 (k⊥ρs = 0.7–4.2) show a pronounced increase of large-scale density fluctuations close to the ECRH radial deposition location at mid-radius, along with a reduction in phase velocity of large-scale density fluctuations. Measurements are compared with results from linear and non-linear flux-matched gyrokinetic (GK) simulations with the gyrokinetic code GENE. Linear GK simulations show a reduction of phase velocity, indicating a pronounced change in the character of the dominant instability. Comparing measurement and non-linear GK simulation, as a central result, agreement is obtained in the shape of radial turbulence level profiles. However, the turbulence intensity is increasing with additional heating in the experiment, while gyrokinetic simulations show a decrease.
Three-dimensional hydrodynamics of the deceleration stage in inertial confinement fusion
Authors: Weber C. R. , Clark D. S. , Cook A. W. , Eder D. C. , Haan S. W. , Hammel B. A. , Hinkel D. E. , Jones O. S. , Marinak M. M. , Milovich J. L. , Patel P. K. , Robey H. F. , Salmonson J. D. , Sepke S. M. , Thomas C. A.
Published: March 2015

The deceleration stage of inertial confinement fusion implosions is modeled in detail using three-dimensional simulations designed to match experiments at the National Ignition Facility. In this final stage of the implosion, shocks rebound from the center of the capsule, forming the high-temperature, low-density hot spot and slowing the incoming fuel. The flow field that results from this process is highly three-dimensional and influences many aspects of the implosion. The interior of the capsule has high-velocity motion, but viscous effects limit the range of scales that develop. The bulk motion of the hot spot shows qualitative agreement with experimental velocity measurements, while the variance of the hot spot velocity would broaden the DT neutron spectrum, increasing the inferred temperature by 400–800 eV. Jets of ablator material are broken apart and redirected as they enter this dynamic hot spot. Deceleration stage simulations using two fundamentally different rad-hydro codes are compared and the flow field is found to be in good agreement.
Dust-lower-hybrid instability with fluctuating charge in quantum plasmas
Authors: Jamil M. , Ali M. , Rasheed A. , Zubia K. , Salimullah M.
Published: March 2015

The instability of Dust-Lower-Hybrid (DLH) wave is examined in detail in the uniform dusty magnetoplasmas. The time dependent charging effects on dust particles around its equilibrium charge Qd0 are taken into account based on Orbit-Limited Probe theory. The quantum characteristics of the system like Bohm potential and Fermi degenerate pressure are dealt using the quantum hydrodynamic model of plasmas. The external magnetic field and size of the dust particles have new physical effects over the dissipative instability of DLH wave in the quantum plasma regime.
Determination of the geometric corrugation of graphene on SiC(0001) by grazing incidence fast atom diffraction
Authors: Zugarramurdi A. , Debiossac M. , Lunca-Popa P. , Mayne A. J. , Momeni A. , Borisov A. G. , Mu Z. , Roncin P. , Khemliche H.
Published: March 2015

We present a grazing incidence fast atom diffraction (GIFAD) study of monolayer graphene on 6H-SiC(0001). This system shows a Moiré-like 13 × 13 superlattice above the reconstructed carbon buffer layer. The averaging property of GIFAD results in electronic and geometric corrugations that are well decoupled; the graphene honeycomb corrugation is only observed with the incident beam parallel to the zigzag direction while the geometric corrugation arising from the superlattice is revealed along the armchair direction. Full-quantum calculations of the diffraction patterns show the very high GIFAD sensitivity to the amplitude of the surface corrugation. The best agreement between the calculated and measured diffraction intensities yields a corrugation height of 0.27 ± 0.03 Å.
Fabrication of silicon nanowire/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)-graphene oxide hybrid solar cells
Authors: Uma Kasimayan , Subramani Thiyagu , Syu Hong-Jhang , Lin Tzu-Ching , Lin Ching-Fuh
Published: March 2015

Silicon nanowire (SiNW)/Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) Schottky junctions have shown great promise as high efficiency, cost effective solar cells. Here, hybrid SiNWs/PEDOT:PSS blended graphene oxide (GO) solar cells are prepared and investigated. The SiNWs/PEDOT:PSS blended GO cells show enhanced light trapping and a large junction area when compared to pure PEDOT:PSS structures. SiNWs combined with GO solar cells show energy conversion efficiencies of up to 9.57% under the AM 1.5G condition, opening the possibility of using semiconductor/graphene oxide in photovoltaic applications.
Recovery effects due to the interaction between nuclear and electronic energy losses in SiC irradiated with a dual-ion beam
Authors: Thomé Lionel , Velisa Gihan , Miro Sandrine , Debelle Aurélien , Garrido Frédérico , Sattonnay Gaël , Mylonas Stamatis , Trocellier Patrick , Serruys Yves
Published: March 2015

Single and dual-beam ion irradiations of silicon carbide (SiC) were performed to study possible Synergetic effects between Nuclear (Sn) and Electronic (Se) Energy Losses. Results obtained combining Rutherford backscattering in channeling conditions, Raman spectroscopy, and transmission electron microscopy techniques show that dual-beam irradiation of SiC induces a dramatic change in the final sample microstructure with a substantial decrease of radiation damage as compared to single-beam irradiation. Actually, a defective layer containing dislocations is formed upon dual-beam irradiation (Sn&Se), whereas single low-energy irradiation (Sn alone) or even sequential (Sn + Se) irradiations lead to full amorphization. The healing process is ascribed to the electronic excitation arising from the electronic energy loss of swift ions. These results shed new light on the long-standing puzzling problem of the existence of a possible synergy between Sn and Se in ion-irradiation experiments. This work is interesting for both fundamental understanding of the ion-solid interactions and technological applications in the nuclear industry where recovery Sn/Se effects may preserve the integrity of nuclear devices.
Discovery of a metastable Al20Sm4 phase
Authors: Ye Z. , Zhang F. , Sun Y. , Mendelev M. I. , Ott R. T. , Park E. , Besser M. F. , Kramer M. J. , Ding Z. , Wang C.-Z. , Ho K.-M.
Published: March 2015

We present an efficient genetic algorithm, integrated with experimental diffraction data, to solve a nanoscale metastable Al20Sm4 phase that evolves during crystallization of an amorphous magnetron sputtered Al90Sm10 alloy. The excellent match between calculated and experimental X-ray diffraction patterns confirms an accurate description of this metastable phase. Molecular dynamic simulations of crystal growth from the liquid phase predict the formation of disordered defects in the devitrified crystal.
Direct growth of nanocrystalline hexagonal boron nitride films on dielectric substrates
Authors: Tay Roland Yingjie , Tsang Siu Hon , Loeblein Manuela , Chow Wai Leong , Loh Guan Chee , Toh Joo Wah , Ang Soon Loong , Teo Edwin Hang Tong
Published: March 2015

Atomically thin hexagonal-boron nitride (h-BN) films are primarily synthesized through chemical vapor deposition (CVD) on various catalytic transition metal substrates. In this work, a single-step metal-catalyst-free approach to obtain few- to multi-layer nanocrystalline h-BN (NCBN) directly on amorphous SiO2/Si and quartz substrates is demonstrated. The as-grown thin films are continuous and smooth with no observable pinholes or wrinkles across the entire deposited substrate as inspected using optical and atomic force microscopy. The starting layers of NCBN orient itself parallel to the substrate, initiating the growth of the textured thin film. Formation of NCBN is due to the random and uncontrolled nucleation of h-BN on the dielectric substrate surface with no epitaxial relation, unlike on metal surfaces. The crystallite size is ∼25 nm as determined by Raman spectroscopy. Transmission electron microscopy shows that the NCBN formed sheets of multi-stacked layers with controllable thickness from ∼2 to 25 nm. The absence of transfer process in this technique avoids any additional degradation, such as wrinkles, tears or folding and residues on the film which are detrimental to device performance. This work provides a wider perspective of CVD-grown h-BN and presents a viable route towards large-scale manufacturing of h-BN substrates and for coating applications.
Energy gap induced by the surface optical polaron in graphene on polar substrates
Authors: Wang Zi-Wu , Liu Lei , Li Zhi-Qing
Published: March 2015

The polaron effects are investigated in the presence of a magnetic field based on the carrier-surface optical phonon coupling induced by the polar substrates under the graphene. We find that the energy gap is opened in the zero-energy Landau level due to the polaron effect. The magnitude of energy gap is consistent with recent experimental measurements. Moreover, the gap can be tuned by choosing the polarization of substrates and controlling the distance between graphene and polar substrate. The results obtained provide a possible explanation for the origin of energy gap opening and highlight the bandgap engineering of graphene on polar substrates.
Microwave-induced dynamic switching of magnetic skyrmion cores in nanodots
Authors: Zhang Bin , Wang Weiwei , Beg Marijan , Fangohr Hans , Kuch Wolfgang
Published: March 2015

The nonlinear dynamic behavior of a magnetic skyrmion in circular nanodots was studied numerically by solving the Landau-Lifshitz-Gilbert equation with a classical spin model. We show that a skyrmion core reversal can be achieved within nanoseconds using a perpendicular oscillating magnetic field. Two symmetric switching processes that correspond to excitations of the breathing mode and the mixed mode (combination of the breathing mode and a radial spin-wave mode) are identified. For excitation of the breathing mode, the skyrmion core switches through nucleation of a new core from a transient uniform state. In the mixed mode, the skyrmion core reverses with the help of spins excited both at the edge and core regions. Unlike the magnetic vortex core reversal, the excitation of radial spin waves does not dominate the skyrmion core reversal process.
Top-gate organic depletion and inversion transistors with doped channel and injection contact
Authors: Liu Xuhai , Kasemann Daniel , Leo Karl
Published: March 2015

Organic field-effect transistors constitute a vibrant research field and open application perspectives in flexible electronics. For a commercial breakthrough, however, significant performance improvements are still needed, e.g., stable and high charge carrier mobility and on-off ratio, tunable threshold voltage, as well as integrability criteria such as n- and p-channel operation and top-gate architecture. Here, we show pentacene-based top-gate organic transistors operated in depletion and inversion regimes, realized by doping source and drain contacts as well as a thin layer of the transistor channel. By varying the doping concentration and the thickness of the doped channel, we control the position of the threshold voltage without degrading on-off ratio or mobility. Capacitance-voltage measurements show that an inversion channel can indeed be formed, e.g., an n-doped channel can be inverted to a p-type inversion channel with highly p-doped contacts. The Cytop polymer dielectric minimizes hysteresis, and the transistors can be biased for prolonged cycles without a shift of threshold voltage, indicating excellent operation stability.
Influence of heat and mass flux conditions in hydromagnetic flow of Jeffrey nanofluid
Authors: Abbasi F. M. , Shehzad S. A. , Hayat T. , Alsaedi A. , Obid Mustafa A.
Published: March 2015

This article explores the hydromagnetic steady flow of Jeffrey fluid in the presence of thermal radiation. The chosen nanofluid model takes into account the Brownian motion and thermophoresis effects. Flow and heat transfer characteristics are determined by a stretching surface with flux conditions. The nonlinear boundary layer flow through partial differential systems is converted into the ordinary differential systems. The resulting reduced systems are computed for the convergent solutions of velocity, temperature and nanoparticle concentration. Graphs of dimensionless temperature and nanoparticle concentration profiles are presented for different values of emerging parameters. Skin-friction coefficient are computed and analyzed in both hydrodynamic and hydromagnetic flow situations.
Length-dependent thermal transport and ballistic thermal conduction
Authors: Huang Bor-Woei , Hsiao Tzu-Kan , Lin Kung-Hsuan , Chiou Dah-Wei , Chang Chih-Wei
Published: March 2015

Probing length-dependent thermal conductivity of a given material has been considered as an important experimental method to determine the length of ballistic thermal conduction, or equivalently, the averaged phonon mean free path (l). However, many previous thermal transport measurements have focused on varying the lateral dimensions of samples, rendering the experimental interpretation indirect. Moreover, deducing l is model-dependent in many optical measurement techniques. In addition, finite contact thermal resistances and variations of sample qualities are very likely to obscure the effect in practice, leading to an overestimation of l. We point out that directly investigating one-dimensional length-dependent (normalized) thermal resistance is a better experimental method to determine l. In this regard, we find that no clear experimental data strongly support ballistic thermal conduction of Si or Ge at room temperature. On the other hand, data of both homogeneously-alloyed SiGe nanowires and heterogeneously-interfaced Si-Ge core-shell nanowires provide undisputed evidence for ballistic thermal conduction over several micrometers at room temperature.
Multisite analysis of the timing and outcomes of unplanned transfers from subacute to acute care
Authors: Considine Julie , Street Maryann , Botti Mari , O'Connell Bev , Kent Bridie , Dunning Trisha
Published: March 2015

Objective The aim of the present study was to examine the timing and outcomes of patients requiring an unplanned transfer from subacute to acute care. Methods Subacute care in-patients requiring unplanned transfer to an acute care facility within four Victorian health services from 1 January to 31 December 2010 were included in the study. Data were collected using retrospective audit. The primary outcome was transfer within 24 h of subacute care admission. Results In all, 431 patients (median age 81 years) had unplanned transfers; of these, 37.8% had a limitation of medical treatment (LOMT) order. The median subacute care length of stay was 43 h: 29.0% of patients were transferred within 24 h and 83.5% were transferred within 72 h of subacute care admission. Predictors of transfer within 24 h were comorbidity weighting (odds ratio (OR) 1.1, P = 0.02) and LOMT order (OR 2.1, P < 0.01). Hospital admission occurred in 87.2% of patients and 15.4% died in hospital. Predictors of in-hospital mortality were comorbidity weighting (OR 1.2, P < 0.01) and the number of physiological abnormalities in the 24 h preceding transfer (OR 1.3, P < 0.01). Conclusions There is a high rate of unplanned transfers to acute care within 24 h of admission to subacute care. Unplanned transfers are associated with high hospital admission and in-hospital mortality rates. What is known about the topic? Subacute care is becoming a high acuity environment where many patients are at significant risk of clinical deterioration. Systems for recognising and responding to deteriorating patients are well developed in acute care, but still developing in subacute care. What does this paper add? This is the first Australian multisite study of clinical deterioration in patients situated in subacute care facilities. One-third of unplanned transfers occur within 24 h of admission to subacute care. Patients who require unplanned transfer from subacute to acute care have unexpectedly high hospital admission rates and high in-hospital mortality rates. The frequency and completeness of physiological monitoring preceding transfer was low. What are the implications for practitioners? Patients in subacute care require regular physiological assessment and early escalation of care if there are physiological abnormalities. Risk of clinical deterioration should be a factor in the decision to admit patients to subacute care after an acute illness or injury. There is a need to improve systems for recognising and responding to deteriorating patients in subacute care settings.
Searching behaviour of Dolichogenidea tasmanica in response to susceptible instars of Epiphyas postvittana
Authors: Yazdani Maryam , Glatz Richard , Keller Michael A.
Published: March 2015

Dolichogenidea tasmanica (Hymenoptera: Braconidae) is the most commonly reared parasitoid from larval light brown apple moth (LBAM), Epiphyas postvittana (Lepidoptera: Tortricidae), feeding on grapevines in Australia. In order to evaluate the efficiency of searching behaviour of D. tasmanica, a laboratory study was undertaken to determine how this wasp responds to the susceptible stages of larval LBAM. Observations of searching behaviour were made in a wind tunnel, which allowed the wasp to express its full range of behaviour. The behaviour of D. tasmanica and susceptibility of LBAM to parasitism varies significantly among instars. The wasp most readily parasitises newly hatched larvae, but can parasitise the first three of the six instars. The first instars cause less damage and also produce less faeces and silk than later instars, so they are associated with less volatile cues that may be detected by the parasitoid. Flight initiation to an infested leaf was lower in the presence of first instars compared with second and third instars. The flight duration was shortest when females were exposed to plants infested by third instars. An analysis of the sequence and timing of searching behaviour indicated that females respond differently to each of the instars of LBAM.
Differential Object Marking and the nature of dative Case in Basque varieties*
Authors: Odria Ane
Published: March 2015

This article analyzes the nature of Differential Object Marking (DOM) in Basque varieties. It demonstrates that, despite their identical dative morphology, DOM objects display a different syntax to goal indirect objects. Based on the licensing of depictive secondary predication and on the absolutive marking of non-human and indefinite objects, it argues that DOM objects are generated in a direct rather than indirect object configuration. Moreover, given the tight relation between case and agreement in ditransitive constructions and the possibility to check Case in Exceptional Case Marking (ECM) contexts, it proposes that dative Case in DOM is structurally checked in an Agree relation against a functional head of the verbal agreement complex. The article thus identifies a different dative argument which has not been previously characterized in this manner: one that does not originate within an applicative or postpositional phrase and checks Case structurally.
A tonal semi-reversal in Franconian dialects
Authors: Köhnlein Björn
Published: March 2015

This paper examines the genesis of a tonal semi-reversal in Franconian tone accent dialects, the so-called Rule A vs. Rule B. Contrary to the traditional assumption, the reversal takes place only under declarative intonation, but not in interrogatives. To account for the semi-reversal, I provide a scenario in which Rule A and Rule B derive from a common predecessor system, which I refer to as Rule 0. These novel findings have important consequences for our understanding of the accent genesis in general: I argue that a combination of my approach for the split with duration-based genesis scenarios leads to a plausible account. As the paper discusses in detail, it is problematic to adapt (previous) alternative proposals to the full data set.
Competition between rhythmic and linguistic organization in a sentence-rhythm Stroop task
Authors: Getz Laura M. , Salona Priyanka , Yu Minhong , Kubovy Michael
Published: March 2015

We provide a test of Patel's [(2003). Language, music, syntax and the brain. Nature Neuroscience, 6, 674–681] shared syntactic integration resources hypothesis by investigating the competition between determinants of rhythmic parsing and linguistic parsing using a sentence-rhythm Stroop task. We played five-note rhythm patterns in which each note is replaced with a spoken word of a five-word sentence and asked participants to indicate the starting point of the rhythm while they disregarded which word would normally be heard as the first word of the sentence. In Study 1, listeners completed the task in their native language. In Study 2, we investigated whether this competition is weakened if the sentences were in a listener's non-native language. In Study 3, we investigated how much language mastery is necessary to obtain the effects seen in Studies 1 and 2. We demonstrate that processing resources for rhythmic parsing and linguistic parsing overlap with one another, particularly when the task is demanding. We also show that the tendency for language to bias processing does not require deep knowledge of the language.
Female Virtue and the Embodiment of Beauty: Vittoria Colonna in Paolo Giovio’sNotable Men and Women*
Authors: Gouwens Kenneth
Published: March 2015

In a dialogue drafted soon after the Sack of Rome (1527), Paolo Giovio details historical views of female dignity and assesses the beauty and talents of over 100 women in contemporary Florence, Genoa, Milan, Naples, and Rome. Unlike most such catalogues, Giovio’s seasons praise with explicit acknowledgment of physical, intellectual, and personal shortcomings. Yet it also celebrates Vittoria Colonna, who commissioned the work, as the ideal noblewoman. Giovio is unconventional in applying to this living woman a pattern of graphic physical description that Petrarch, Boccaccio, Bembo, and many others had followed in delineating fictional characters. This strategy exemplifies the latitude of representational possibilities that characterized Italian literature and art of the 1520s and 1530s. The dialogue also eloquently documents a crucial time in Colonna’s life when her verse commemoration of her husband coalesced with religious devotion, and when physical beauty could be seen to harmonize with other virtues to form a desirable and inspirational whole.
Reversible phase transition of 2-carboxypyridinium perchlorate–pyridinium-2-carboxylate (1/1)
Authors: Wang Bi-Qin , Yan Hai-Biao , Huang Zheng-Qing , Zhang Yun-Hua , Sun Jing
Published: March 2015

The title salt, C6H6NO2+·ClO4−·C6H5NO2, was crystallized from an aqueous solution of equimolar quantities of perchloric acid and pyridine-2-carboxylic acid. Differential scanning calorimetry (DSC) measurements show that the compound undergoes a reversible phase transition at about 261.7 K, with a wide heat hysteresis of 21.9 K. The lower-temperature polymorph (denoted LT;T= 223 K) crystallizes in the space groupC2/c, while the higher-temperature polymorph (denoted RT;T= 296 K) crystallizes in the space groupP2/c. The relationship between these two phases can be described as: 2aRT=aLT; 2bRT=bLT;cRT=cLT. The crystal structure contains an infinite zigzag hydrogen-bonded chain network of 2-carboxypyridinium cations. The most distinct difference between the higher (RT) and lower (LT) temperature phases is the change in dihedral angle between the planes of the carboxylic acid group and the pyridinium ring, which leads to the formation of different ten-membered hydrogen-bonded rings. In the RT phase, both the perchlorate anions and the hydrogen-bonded H atom within the carboxylic acid group are disordered. The disordered H atom is located on a twofold rotation axis. In the LT phase, the asymmetric unit is composed of two 2-carboxypyridinium cations, half an ordered perchlorate anion with ideal tetrahedral geometry and a disordered perchlorate anion. The phase transition is attributable to the order–disorder transition of half of the perchlorate anions.
A two-dimensional silver(I) coordination polymer constructed from 4-aminophenylarsonate and triphenylphosphane: poly[[(μ3-4-aminophenylarsonato-κ3N:O:O)(triphenylphosphane-κP)silver(I)] monohydrate]
Authors: Xiao Zu-Ping , Wen Meng , Wang Chun-Ya , Huang Xi-He
Published: March 2015

The title compound, {[Ag(C6H7AsNO3)(C18H15P)]·H2O}n, has been synthesized from the reaction of 4-aminophenylarsonic acid with silver nitrate, in aqueous ammonia, with the addition of triphenylphosphane (PPh3). The AgIcentre is four-coordinated by one amino N atom, one PPh3P atom and two arsonate O atoms, forming a severely distorted [AgNPO2] tetrahedron. Two AgI-centred tetrahedra are held together to produce a dinuclear [Ag2O2N2P2] unit by sharing an O–O edge. 4-Aminophenylarsonate (Hapa−) adopts a μ3-κ3N:O:O-tridentate coordination mode connecting two dinuclear units, resulting in a neutral [Ag(Hapa)(PPh3)]nlayer lying parallel to the (10\overline{1}) plane. The PPh3ligands are suspended on both sides of the [Ag(Hapa)(PPh3)]nlayer, displaying up and down orientations. There is anR22(8) hydrogen-bonded dimer involving two arsonate groups from two Hapa−ligands related by a centre of inversion. Additionally, there are hydrogen-bonding interactions involving the solvent water molecules and the arsonate and amine groups of the Hapa−ligands, and weak π–π stacking interactions within the [Ag(Hapa)(PPh3)]nlayer. These two-dimensional layers are further assembled by weak van der Waals interactions to form the final architecture.
A theory of planned behavior perspective on hiring Malaysians with disabilities
Authors: Ang Magdalene C.H. , Ramayah T. , Amin Hanudin
Published: March 2015

Purpose

– The high unemployment rates among persons with disabilities (PWDs) is nothing new. Many people fail to recognize that the disabled population is a significant but largely untapped source of human resources. Prejudices and misconceptions about PWDs’ ability to perform and compete in the open market are likely to be the cause. While the topic of PWDs’ employment has been substantially studied, no known research has explored the applicability of the theory of planned behavior (TPB) in the context of hiring PWDs. In addressing the research gap, this paper details a preliminary study which examined the influence of attitude, subjective norm, and perceived behavioral control on managerial intention to hire Malaysians with disabilities. The paper aims to discuss these issues.

Design/methodology/approach

– Data were obtained via a survey on 200 employers representing private organizations in East Malaysia. To examine the hypothesized linkages within the TPB framework, the authors conducted PLS analysis. The authors also examined the measurement model using PLS.

Findings

– The results of the PLS analysis indicated that subjective norm and perceived behavioral control significantly predicted managerial intention to hire Malaysians with disabilities. Contrary to expectations, the data did not provide support for the influence of attitude toward hiring decisions for PWDs.

Research limitations/implications

– Given the research approach, generalizing the findings must be done with caution. Longitudinal studies may provide further support to the results. Future studies can extend the TPB framework by examining other variables such as attributes of Malaysians with disabilities or those of hiring managers. Hiring behavior can also be included in the model to confirm if behavioral intention of hiring will evidently result in actual hiring of Malaysians with disabilities.

Practical implications

– This study found the TPB to have a predictive power in the area of hiring PWDs. Results obtained can serve as a basis for future works in this area. The study also offers implications for the development of public and organizational policies that can better promote and manage the careers of Malaysians with disabilities.

Social implications

– An enhanced knowledge about the factors which can influence managerial intention to hire Malaysians with disabilities will help increase the employment of Malaysians with disabilities.

Originality/value

– This study is a pioneering attempt to explore the applicability of the TPB within the domain of managerial intention to hire Malaysians with disabilities. The use of PLS in disability studies is also noteworthy.