bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface electric fields for North America during historical geomagnetic storms
Authors: Wei Lisa H. , Homeier Nicole , Gannon Jennifer L.
Published: July 2013

To better understand the impact of geomagnetic disturbances on the electric grid, we recreate surface electric fields from two historical geomagnetic storms—the 1989 “Quebec” storm and the 2003 “Halloween” storms. Using the Spherical Elementary Current Systems method, we interpolate sparsely distributed magnetometer data across North America. We find good agreement between the measured and interpolated data, with larger RMS deviations at higher latitudes corresponding to larger magnetic field variations. The interpolated magnetic field data are combined with surface impedances for 25 unique physiographic regions from the United States Geological Survey and literature to estimate the horizontal, orthogonal surface electric fields in 1 min time steps. The induced horizontal electric field strongly depends on the local surface impedance, resulting in surprisingly strong electric field amplitudes along the Atlantic and Gulf Coast. The relative peak electric field amplitude of each physiographic region, normalized to the value in the Interior Plains region, varies by a factor of 2 for different input magnetic field time series. The order of peak electric field amplitudes (largest to smallest), however, does not depend much on the input. These results suggest that regions at lower magnetic latitudes with high ground resistivities are also at risk from the effect of geomagnetically induced currents. The historical electric field time series are useful for estimating the flow of the induced currents through long transmission lines to study power flow and grid stability during geomagnetic disturbances.
Personalisation in Election Campaigns in the Czech Republic
Authors: Poláček Jaroslav
Published: July 2013

There are two key contexts in which the term ‘personalisation of election campaigns’ occurs: the role of a leader and direct communication with voters. Although the influence of candidates is a phenomenon that has long been studied by political science, the degree of influence of personal communication has not been explored extensively even though the two are closely related. This article describes both aspects of personalisation with respect to the way they are employed in different kinds of election campaign in the Czech Republic.
2014 European Elections: European Political Parties, Presidential Candidates and the Pan-eu Campaign
Authors: Sasmatzoglou Kostas
Published: July 2013

The 2014 European elections will be the first to take place under the Lisbon Treaty. The nomination of presidential candidates by European political parties will personalise the campaign and will trigger the interest of the European public.
Decline of the Media? Decline of Democracy?
Authors: Hopia Henna
Published: July 2013

The media play a leading role in democracies. Their task is to enable citizens to make informed decisions by providing them with a balanced picture of the complex world. However, amongst journalists, the general knowledge of and interest in politics and EU affairs seems somewhat poor, which means that the media are not doing their job, and this is reflected in society. Media reporting on the EU is predominantly negative and therefore cannot give a balanced view to the public in order to promote a healthy European democracy. Instead, the changes taking place in the media landscape seem to promote entertainment and market values over political content, a development which benefits politicians suited to this arena, such as populists.
The Evolution of the ‘populist Potential’ in European Politics: From New Right Radicalism to Anti-system Populism
Authors: Chryssogelos Angelos-Stylianos
Published: July 2013

Over the past 30 years, responding to different international, political and economic circumstances, populists have formed, preserved, nurtured and expanded a political identity that is today present in most political systems in Europe. This identity constitutes a ‘populist potential’, in the sense that it is non-ideological and that it wavers between electoral abstention and support for anti-system parties. This article provides a historical overview of the ideological and sociological evolution of the populist identity in Europe and reviews the ways parties of the centre-right have dealt with it in the past. Its conclusion is that practices like coalition building and theme co-optation are not so easy to deploy today, given the non-ideological and anti-system nature of the populist potential.
Reaching the Citizens: Door-to-door Campaigning
Authors: Keschmann Markus
Published: July 2013

When we look at recent election campaigns in Europe or at the presidential elections in the United States, for example, we see that successful campaign concepts are always about voter mobilisation. Although the focus of the political debate in this regard is on the allocation of resources, the use of social media and television budgets, it is actually another question that is essential: how do we reach and target the right people? The answer to this question is as simple as it is old: face-to-face communication and personal conversation. In this respect, political parties based on a strong party structure are at an advantage: they generally possess vast databases full of contacts and further information details. The only challenge is to make good use of these resources.
The Gender Issue in Belgian Party Politics and Elections
Authors: De Bethune Sabine , Van Hoof Els , Albright Madeleine K.
Published: July 2013

This article looks at how female politicians in Belgium, driven by a strong women's movement, have sought to achieve gender parity in politics. The first part explains the system of legislated candidate quotas introduced in 1994. The second part deals with the way the Flemish Christian Democratic party and its women's movement, which greatly contributed to the establishment of the quota system, have used the new legal framework to raise awareness and promote female candidates during and beyond election campaigns. We will conclude that both adequate legal conditions and a proactive stance towards women's empowerment on the part of political parties are crucial to achieving gender parity.
Identification of Lagrangian coherent structures in a turbulent boundary layer
Authors: Wilson Z. D. , Tutkun M. , Cal R. B.
Published: July 2013

Lagrangian coherent structures (LCS) of a turbulent boundary layer at${\mathit{Re}}_{\theta } $of 9800 are identified in a plane parallel to the wall at${y}^{+ } = 50$. Three-component high-speed stereo particle image velocimetry measurements on a two-dimensional rectangular plane are used for the analysis. The velocity field is extended in the streamwise direction, using Taylor’s frozen field hypothesis. A computational approach utilizing the variational theory of hyperbolic Lagrangian coherent structures is applied to the domain and trajectories are computed using the extended field. The method identified both attracting and repelling Lagrangian coherent structures. There are no apparent differences in distribution of size, orientation and location of attracting and repelling structures. Hyperbolic behaviour appeared in the fluid at and around points of intersection between the attracting and repelling Lagrangian coherent structures. The network of curves identifying distinct regions of coherent flow patterns is displayed in observed relationship between the arrangement of Lagrangian coherent structures and various Eulerian fields.
Invariants for slightly heated decaying grid turbulence
Authors: Antonia R. A. , Lee S. K. , Djenidi L. , Lavoie P. , Danaila L.
Published: July 2013

The paper examines the validity of velocity and scalar invariants in slightly heated and approximately isotropic turbulence generated by passive conventional grids. By assuming that the variances $\langle {u}^{2} \rangle $ and $\langle {\theta }^{2} \rangle $ ($u$ and $\theta $ represent the longitudinal velocity and temperature fluctuations) decay along the streamwise direction $x$ according to power laws $\langle {u}^{2} \rangle \sim {(x- {x}_{0} )}^{{n}_{u} } $ and $\langle {\theta }^{2} \rangle \sim {(x- {x}_{0} )}^{{n}_{\theta } } $ (${x}_{0} $ is the virtual origin of the flow) and with the further assumption that the one-point energy and scalar variance budgets are represented closely by a balance between the rates of change of $\langle {u}^{2} \rangle $ and $\langle {\theta }^{2} \rangle $ and the corresponding mean energy dissipation rates, the products $\langle {u}^{2} \rangle { \lambda }_{u}^{- 2{n}_{u} } $ and $\langle {\theta }^{2} \rangle { \lambda }_{\theta }^{- 2{n}_{\theta } } $ must remain constant with respect to $x$. Here ${\lambda }_{u} $ and ${\lambda }_{\theta } $ are the Taylor and Corrsin microscales. This is unambiguously supported by previously available data, as well as new measurements of $u$ and $\theta $ made at small Reynolds numbers downstream of three different biplane grids. Implications for invariants based on measured integral length scales of $u$ and $\theta $ are also tested after confirming that the dimensionless energy and scalar variance dissipation rate parameters are approximately constant with $x$. Since the magnitudes of ${n}_{u} $ and ${n}_{\theta } $ vary from grid to grid and may also depend on the Reynolds number, the Saffman and Corrsin invariants which correspond to a value of $- 1. 2$ for ${n}_{u} $ and ${n}_{\theta } $ are unlikely to apply in general. The effect of the Reynolds number on ${n}_{u} $ is discussed in the context of published data for both passive and active grids.
Direct numerical evidence of stress-induced cavitation
Authors: Falcucci G. , Jannelli E. , Ubertini S. , Succi S.
Published: July 2013

In this paper direct numerical evidence of flow-induced incipient cavitation is presented through lattice Boltzmann simulations of multiphase flows with a non-ideal thermodynamic equation of state. Cavitation emerges spontaneously as a result of the underlying non-ideal interactions, with no need for any modelling criteria based on the fluid variables, such as pressure or stress tensor. The onset of cavitation is well captured by Joseph’s minimum tension criteria, (Joseph,J. Fluid Mech., vol. 366, 1998, pp. 367–378; Dabiri, Sirignano & Joseph,Phys. Fluids, vol. 19, 2007, 072112), complemented with surface tension corrections, as proposed by Brennen (Cavitation and Bubble Dynamics, Oxford University Press, 1995). The simulations also show that the cavitation number (${C}_{N} $) proves to be a poor predictor of the onset of cavitation. Finally, strong dependence of the bubble morphology on the surface tension is also highlighted.
Change in drag, apparent slip and optimum air layer thickness for laminar flow over an idealised superhydrophobic surface
Authors: Busse A. , Sandham N. D. , McHale G. , Newton M. I.
Published: July 2013

Analytic results are derived for the apparent slip length, the change in drag and the optimum air layer thickness of laminar channel and pipe flow over an idealised superhydrophobic surface, i.e. a gas layer of constant thickness retained on a wall. For a simple Couette flow the gas layer always has a drag reducing effect, and the apparent slip length is positive, assuming that there is a favourable viscosity contrast between liquid and gas. In pressure-driven pipe and channel flow blockage limits the drag reduction caused by the lubricating effects of the gas layer; thus an optimum gas layer thickness can be derived. The values for the change in drag and the apparent slip length are strongly affected by the assumptions made for the flow in the gas phase. The standard assumptions of a constant shear rate in the gas layer or an equal pressure gradient in the gas layer and liquid layer give considerably higher values for the drag reduction and the apparent slip length than an alternative assumption of a vanishing mass flow rate in the gas layer. Similarly, a minimum viscosity contrast of four must be exceeded to achieve drag reduction under the zero mass flow rate assumption whereas the drag can be reduced for a viscosity contrast greater than unity under the conventional assumptions. Thus, traditional formulae from lubrication theory lead to an overestimation of the optimum slip length and drag reduction when applied to superhydrophobic surfaces, where the gas is trapped.
Coalescence of drops with mobile interfaces in a quiescent fluid
Authors: Nemer M. B. , Santoro P. , Chen X. , Bławzdziewicz J. , Loewenberg M.
Published: July 2013

A study on the axisymmetric near-contact motion of drops with tangentially mobile interfaces under the action of a body force in a quiescent fluid is described. A long-time asymptotic analysis is presented for small-deformation conditions. Under these conditions the drops are nearly spherical, except in the near-contact region, where a flattened thin film forms. According to our analysis, a hydrostatic dome does not form in the near-contact region at long times, in contrast to the assumption underlying all previous analyses of this problem. Instead, the shape of the film in the near-contact region results from the absence of tangential stresses acting on it. As a result, the long-time behaviour of the system is qualitatively different than previously predicted. According to the theory presented herein, the minimum film thickness (rim region) decays with time as ${h}_{m} \sim {t}^{- 4/ 5} $, and the thickness at the centre of the film decays as ${h}_{0} \sim {t}^{- 3/ 5} $, which is a faster decay than predicted by prior analyses based on a hydrostatic dome. Numerical thin-film simulations quantitatively confirm the predictions of our small-deformation theory. Boundary-integral simulations of the full two-drop problem suggest that the theory also describes qualitatively the long-time evolution under finite-deformation conditions.
Energy consumption of mobile agents in a wireless ad hoc network environment
Authors: Holt Alan , Huang Chi‐Yu
Published: July 2013

In this study the authors consider the energy consumption of mobile agents operating in wireless local area network (WLAN) environment. They present an energy model of an ad hoc WLAN based on the IEEE 802.11 standard and analyse both per‐device and WLAN‐wide energy consumption. With this model the authors investigate ‘features’ of the 802.11 protocol (such as frame fragmentation, preamble/header lengths and power‐save schemes) on energy consumption in the context of a mobile agent management domain. They also consider ‘clustering’ as a means of optimising energy consumption.
Criterion for selecting the shape functions in electromagnetic meshless methods
Authors: Afsari Arman , Movahhedi Masoud
Published: July 2013

The root of this study, comes from the lack of regularity where exists in shape function selection in meshless methods. Up to now, shape functions in meshless methods were being established by basis functions. In other words, there was no predictable rule by which the shape functions be predetermined, without any need to basis functions. In presented approach, the authors are going to establish a criterion, which is based on both analytical and simulation results; helps select an approximately well‐behaved shape function for which the shape parameters have been predetermined. This work focused on both Laplace and wave equations as the most important equations in electrostatic and electromagnetic problems to show the validation of the proposed approach in computational electromagnetics. Comparing the results with radial point interpolation method as the most common existing meshless method, finite‐element method and finite‐difference method, the criterion shows extremely good accuracy despite a great reduction in time consumption rate for selecting a compatible shape function.
Compact photonic-crystal superabsorbers from strongly absorbing media
Authors: Devarapu G. C. R. , Foteinopoulou S.
Published: July 2013

We present a route to near-perfect absorption in compact photonic-crystal (PC) structures constructed from strongly absorbing media that are typically highly reflective in bulk form. Our analysis suggests that the key underlying mechanism in such PC superabsorbers is the existence of a PC-band-edge reflectionless condition. Although the latter is by default uncharacteristic in photonic crystals, we propose here a clear recipe on how such condition can be met by tuning the structural characteristics of one-dimensional lossy PC structures. Based on this recipe, we constructed a realizable three-layer SiC-BaF2-SiC PC operating within the Reststrahlen band of SiC. We demonstrate near-perfect absorption in this prototype of total thickness smaller than λ/3, where more than 90% of the impinging light is absorbed by the top deep-subwavelength layer of thickness ∼λ/1100. We believe our study will inspire new photonic-crystal-based designs for extreme absorption harnessing across the electromagnetic spectrum.
Reduced explicitly correlated Hartree-Fock approach within the nuclear-electronic orbital framework: Applications to positronic molecular systems
Authors: Sirjoosingh Andrew , Pak Michael V. , Swalina Chet , Hammes-Schiffer Sharon
Published: July 2013

In the application of the nuclear-electronic orbital (NEO) method to positronic systems, all electrons and the positron are treated quantum mechanically on the same level. Explicit electron-positron correlation can be included using Gaussian-type geminal functions within the variational self-consistent-field procedure. In this paper, we apply the recently developed reduced explicitly correlated Hartree-Fock (RXCHF) approach to positronic molecular systems. In the application of RXCHF to positronic systems, only a single electronic orbital is explicitly correlated to the positronic orbital. We apply NEO-RXCHF to three systems: positron-lithium, lithium positride, and positron-lithium hydride. For all three of these systems, the RXCHF approach provides accurate two-photon annihilation rates, average contact densities, electronic and positronic single-particle densities, and electron-positron contact densities. Moreover, the RXCHF approach is significantly more accurate than the original XCHF approach, in which all electronic orbitals are explicitly correlated to the positronic orbital in the same manner, because the RXCHF wavefunction is optimized to produce a highly accurate description of the short-ranged electron-positron interaction that dictates the annihilation rates and other local properties. Furthermore, RXCHF methods that neglect or approximate the electronic exchange interactions between the geminal-coupled electronic orbital and the regular electronic orbitals lead to virtually identical annihilation rates and densities as the fully antisymmetric RXCHF method but offer substantial advantages in computational tractability. Thus, NEO-RXCHF is a promising, computationally practical approach for studying larger positron-containing systems.
Systematic investigation of surface and bulk electronic structure of undoped In-polar InN epilayers by hard X-ray photoelectron spectroscopy
Authors: Imura Masataka , Tsuda Shunsuke , Nagata Takahiro , Takeda Hiroyuki , Liao Meiyong , Yang AnLi , Yamashita Yoshiyuki , Yoshikawa Hideki , Koide Yasuo , Kobayashi Keisuke , Yamaguchi Tomohiro , Kaneko Masamitsu , Uematsu Nao , Araki Tsutomu , Nanishi Yasushi
Published: July 2013

The surface and bulk electronic structure of undoped In-polar InN (u-InN) epilayers with surface electron accumulation (SEA) layer was investigated by soft and hard X-ray photoelectron spectroscopies (SX-PES and HX-PES, respectively). The potential-energy profile was obtained by fitting the N 1s core-level spectra accounting for the probing depth of both SX-PES and HX-PES and the surface downward band bending. In this study, we found that a significant potential-energy bending as large as 1.2 ± 0.05 eV occurred from surface to the depth of ∼20 nm. Taking into account such a large downward bending, the valence band maximum (VBM) with respect to Fermi energy (EF) level in the bulk was determined to be 0.75 ± 0.05 eV. A weak signal with a peak position at 0.3 ± 0.05 eV was reproducibly observed from the VBM to EF level in the HX-PES spectrum. The peak position was in agreement with the calculated energy of the E1 sub-band in the surface quantum well. HX-PES is powerful tool for revealing the intrinsic bulk electronic structure of materials with large potential-energy bending. This work provides important information for the future investigation of electronic structures of undoped and Mg-doped InGaN, as well as Mg-doped InN epilayers with a SEA layer similar to u-InN.
Consistent coarse-graining strategy for polymer solutions in the thermal crossover from good to θ solvent
Authors: D'Adamo Giuseppe , Pelissetto Andrea , Pierleoni Carlo
Published: July 2013

We extend our previously developed coarse-graining strategy for linear polymers with a tunable number n of effective atoms (blobs) per chain [G. D'Adamo et al., J. Chem. Phys. 137, 024901 (2012)]10.1063/1.4732851 to polymer systems in thermal crossover between the good-solvent and the θ regimes. We consider the thermal crossover in the region in which tricritical effects can be neglected, i.e., not too close to the θ point, for a wide range of chain volume fractions Φ = c/c* (c* is the overlap concentration), up to Φ ≈ 30. Scaling crossover functions for global properties of the solution are obtained by Monte Carlo simulations of the Domb-Joyce model with suitably rescaled on-site repulsion. They provide the input data to develop a minimal coarse-grained model with four blobs per chain (tetramer model). As in the good-solvent case, the coarse-grained model potentials are derived at zero density, thus avoiding the inconsistencies related to the use of state-dependent potentials. We find that the coarse-grained model reproduces the properties of the underlying, full-monomer system up to some reduced density Φ which increases when lowering the temperature towards the θ state. Close to the lower-temperature crossover boundary, the tetramer model is accurate at least up to Φ ≃ 10, while near the good-solvent regime reasonably accurate results are obtained up to Φ ≃ 2. The density region in which the coarse-grained model is predictive can be enlarged by developing coarse-grained models with more blobs per chain. We extend the strategy used in the good-solvent case to the crossover regime. This requires a proper treatment of the length rescalings as before, but also a proper temperature redefinition as the number of blobs is increased. The case n = 10 is investigated in detail. We obtain the potentials for such finer-grained model starting from the tetramer ones. Comparison with full-monomer results shows that the density region in which accurate predictions can be obtained is significantly wider than that corresponding to the tetramer case.
A high-order harmonic generation apparatus for time- and angle-resolved photoelectron spectroscopy
Authors: Frietsch B. , Carley R. , Döbrich K. , Gahl C. , Teichmann M. , Schwarzkopf O. , Wernet Ph. , Weinelt M.
Published: July 2013

We present a table top setup for time- and angle-resolved photoelectron spectroscopy to investigate band structure dynamics of correlated materials driven far from equilibrium by femtosecond laser pulse excitation. With the electron-phonon equilibration time being in the order of 1–2 ps it is necessary to achieve sub-picosecond time resolution. Few techniques provide both the necessary time and energy resolution to map non-equilibrium states of the band structure. Laser-driven high-order harmonic generation is such a technique. In our experiment, a grating monochromator delivers tunable photon energies up to 40 eV. A photon energy bandwidth of 150 meV and a pulse duration of 100 fs FWHM allow us to cover the k-space necessary to map valence bands at different kz and detect outer core states.
Interaction flip identities for non-centered spin glasses
Authors: Contucci Pierluigi , Giardinà Cristian , Giberti Claudio
Published: July 2013

We consider spin glass models with non-centered interactions and investigate the effect, on the random free energies, of flipping the interaction in a subregion of the entire volume. A fluctuation bound obtained by martingale methods produces, with the help of integration by parts technique, a family of polynomial identities involving overlaps and magnetizations.
Ultrafast electronic dynamics in laser-excited crystalline bismuth
Authors: Melnikov Alexey A. , Misochko Oleg V. , Chekalin Sergey V.
Published: July 2013

Femtosecond spectroscopy is applied to study transient electronic processes in bismuth. The components with relaxation times of 1 ps, 7 ps, and ∼1 ns are detected in the photoinduced reflectivity response of the crystal. To facilitate assignment of the observed relaxation to the decay of particular excited electronic states, we use pump pulses with central wavelengths ranging from 400 to 2300 nm. Additionally, we examine the variation of parameters of coherent A1g phonons upon the change of excitation and probing conditions. Data analysis reveals significant wavevector dependence of electron-hole and electron-phonon coupling strength along Γ-T direction of the Brillouin zone.
A nonlinear negative stiffness metamaterial unit cell and small-on-large multiscale material model
Authors: Klatt Timothy , Haberman Michael R.
Published: July 2013

A persistent challenge in the design of composite materials is the ability to fabricate materials that simultaneously display high stiffness and high loss factors for the creation of structural elements capable of passively suppressing vibro-acoustic energy. Relevant recent research has shown that it is possible to produce composite materials whose macroscopic mechanical stiffness and loss properties surpass those of conventional composites through the addition of trace amounts of materials displaying negative stiffness (NS) induced by phase transformation [R. S. Lakes et al., Nature 410, 565-567 (2001)]. The present work investigates the ability to elicit NS behavior without employing physical phenomena such as inherent nonlinear material behavior (e.g., phase change or plastic deformation) or dynamic effects, but rather the controlled buckling of small-scale structural elements, metamaterials, embedded in a continuous viscoelastic matrix. To illustrate the effect of these buckled elements, a nonlinear hierarchical multiscale material model is derived, which estimates the macroscopic stiffness and loss of a composite material containing pre-strained microscale structured inclusions. The multiscale model consists of two scale transition models, the first being an energy-based nonlinear finite element (FE) method to determine the tangent modulus of the metamaterial unit cell, and the other a classical analytical micromechanical model to determine the effective stiffness and loss tensors of a heterogeneous material for small perturbations from the local strain state of the unit cells. The FE method enables the estimation of an effective nonlinear anisotropic stiffness tensor of a buckled microstructure that produces NS and is sufficiently general to consider geometries different from those given in this work.
Direct and alignment-insensitive measurement of cantilever curvature
Authors: Hermans Rodolfo I. , Bailey Joe M. , Aeppli Gabriel
Published: July 2013

We analytically derive and experimentally demonstrate a method for the simultaneous measurement of deflection for large arrays of cantilevers. The Fresnel diffraction patterns of a cantilever independently reveal tilt, curvature, cubic, and higher order bending of the cantilever. It provides a calibrated absolute measurement of the polynomial coefficients describing the cantilever shape, without careful alignment and could be applied to several cantilevers simultaneously with no added complexity. We show that the method is easily implemented, works in both liquid media and in air, for a broad range of displacements and is especially suited to the requirements for multi-marker biosensors.
Engineering quantum dots for electrical control of the fine structure splitting
Authors: Pooley M. A. , Bennett A. J. , Farrer I. , Ritchie D. A. , Shields A. J.
Published: July 2013

We have studied the variation in fine-structure splitting (FSS) under application of vertical electric field in a range of quantum dots grown by different methods. In each sample, we confirm that this energy splitting changes linearly over the field range we can access. We conclude that this linear tuning is a general feature of self-assembled quantum dots, observed under different growth conditions, emission wavelengths, and in different material systems. Statistical measurements of characteristic parameters such as emission energy, Stark shift, and FSS tuning are presented which may provide a guide for future attempts to increase the yield of quantum dots that can be tuned to a minimal value of FSS with vertical electric field.
Note: Thermorheological complexity in polymers and the problem of the glass transition
Authors: Ngai K. L. , Roland C. M.
Published: July 2013

A current focus in studies of the glass transition is the role of dynamic heterogeneities. Although these efforts may clarify the origin of the spectacular change in properties of liquids approaching vitrification, we point out that a seemingly related phenomenon – thermorheological complexity in polymers – must involve different mechanisms. In particular, as seen from consideration of various properties involving the chain dynamics, averaging over different length and time scales cannot offer a resolution to the problem of thermorheological complexity.
On the structure of positive maps. II. Low dimensional matrix algebras
Authors: Majewski Władysław A. , Tylec Tomasz I.
Published: July 2013

We use a new idea that emerged in the examination of exposed positive maps between matrix algebras to investigate in more detail the differences and similarities between unital positive maps on \documentclass[12pt]{minimal}\begin{document}$M_{2} (\mathbbm {C})$\end{document}M2(C) and \documentclass[12pt]{minimal}\begin{document}$M_{3}(\mathbbm {C})$\end{document}M3(C). Our main tool stems from classical Grothendieck theorem on tensor product of Banach spaces and is an older and more general version of Choi-Jamiołkowski isomorphism between positive maps and block positive Choi matrices. It takes into account the correct topology on the latter set that is induced by the uniform topology on positive maps. In this setting, we show that in \documentclass[12pt]{minimal}\begin{document}$M_{2}(\mathbbm {C})$\end{document}M2(C) case a large class of nice positive maps can be generated from the small set of maps represented by self-adjoint unitaries, 2Px with x maximally entangled vector and \documentclass[12pt]{minimal}\begin{document}$p\otimes \mathbb {1}$\end{document}p⊗1 with p rank 1 projector. We indicate problems with passing this result to \documentclass[12pt]{minimal}\begin{document}$M_{3}(\mathbbm {C})$\end{document}M3(C) case. Among similarities, in both \documentclass[12pt]{minimal}\begin{document}$M_{2}(\mathbbm {C})$\end{document}M2(C) and \documentclass[12pt]{minimal}\begin{document}$M_{3}(\mathbbm {C})$\end{document}M3(C) cases any unital positive map represented by self-adjoint unitary is unitarily equivalent to the transposition map. Consequently, we obtain a large family of exposed maps. Furthermore, for \documentclass[12pt]{minimal}\begin{document}$M_{3}(\mathbbm {C})$\end{document}M3(C) there appear new non-trivial class of maps represented by Choi matrices with square equal to a projector. We examine this case. We also investigate a convex structure of the Choi map, the first example of non-decomposable map. As a result the nature of the Choi map will be explained.
Spin-transfer torque magnetization reversal in uniaxial nanomagnets with thermal noise
Authors: Pinna D. , Kent A. D. , Stein D. L.
Published: July 2013

We consider the general Landau-Lifshitz-Gilbert (LLG) dynamical theory underlying the magnetization switching rates of a thin film uniaxial magnet subject to spin-torque effects and thermal fluctuations. After discussing the various dynamical regimes governing the switching phenomena, we present analytical results for the mean switching time behavior. Our approach, based on explicitly solving the first passage time problem, allows for a straightforward analysis of the thermally assisted, low spin-torque, switching asymptotics of thin film magnets. To verify our theory, we have developed an efficient Graphics Processing Unit (GPU)-based micromagnetic code to simulate the stochastic LLG dynamics out to millisecond timescales. We explore the effects of geometrical tilts between the spin-current and uniaxial anisotropy axes on the thermally assisted dynamics. We find that even in the absence of axial symmetry, the switching times can be functionally described in a form virtually identical to the collinear case.
Hysteresis in the conductance of asymmetrically biased GaAs quantum point contacts with in-plane side gates
Authors: Bhandari N. , Dutta M. , Charles J. , Cahay M. , Newrock R. S.
Published: July 2013

We have observed hysteresis between the forward and reverse sweeps of a common mode bias applied to the two in-plane side gates of an asymmetrically biased GaAs quantum point contact (QPC). The size of the hysteresis loop increases with the amount of bias asymmetry ΔVg between the two side gates and depends on the polarity of ΔVg. Our results are in qualitative agreement with Non-Equilibrium Green's Function simulations including the effects of dangling bond scattering on the sidewalls of the QPC. It is argued that hysteresis may constitute another indirect proof of spontaneous spin polarization in the narrow portion of the QPC.
Enhancement of the third-order optical nonlinearity in ZnO/Al2O3 nanolaminates fabricated by atomic layer deposition
Authors: Karvonen L. , Säynätjoki A. , Chen Y. , Jussila H. , Rönn J. , Ruoho M. , Alasaarela T. , Kujala S. , Norwood R. A. , Peyghambarian N. , Kieu K. , Honkanen S.
Published: July 2013

We investigate the third-order optical nonlinearity in ZnO/Al2O3 nanolaminates fabricated by atomic layer deposition and show that the third-order optical nonlinearity can be enhanced by nanoscale engineering of the thin film structure. The grain size of the polycrystalline ZnO film is controlled by varying the thickness of the ZnO layers in the nanolaminate in which thin (∼2 nm) amorphous Al2O3 layers work as stopping layers for ZnO crystal growth. Nanoscale engineering enables us to achieve a third harmonic generated signal enhancement of ∼13 times from the optimized nanolaminate structure compared to a ZnO reference film of comparable thickness.
Fast and intense photoluminescence in a SiGe nano-layer embedded in multilayers of Si/SiGe clusters
Authors: Mala S. A. , Tsybeskov L. , Lockwood D. J. , Wu X. , Baribeau J.-M.
Published: July 2013

An intense photoluminescence (PL) peaking near 0.9 eV is emitted by a single Si1−xGex nanometer-thick layer (NL) with x ≈ 8% incorporated into Si/Si0.6Ge0.4 cluster multilayers (CMs). The SiGe NL PL does not saturate in output intensity with up to 50 mJ/cm2 of excitation energy density, and it has nearly a 1000 times shorter lifetime compared to CM PL, which peaks at ∼0.8 eV. These dramatic differences in observed PL properties are attributed to different compositions and structures of the Si/SiGe NL and CM hetero-interfaces.
Interfacial effect on the ferromagnetic damping of CoFeB thin films with different under-layers
Authors: Chen Shaohai , Tang Minghong , Zhang Zongzhi , Ma B. , Lou S. T. , Jin Q. Y.
Published: July 2013

Interfacial effects on magnetic properties are investigated for the as-deposited and annealed Co64Fe16B20 films with different under-layers (Cu, Ru, or Pd). The intrinsic Gilbert damping factor is inferred to be slightly lower than the obtained value of 0.007. We found that both the in-plane coercivity Hc and ferromagnetic resonance linewidth ΔHpp rely on the interfacial morphology. The Cu under-layer provides a rough surface, which offers an extra contribution to the ΔHpp. The surface roughness was greatly enhanced by post-annealing for Cu, while little affected for Ru and Pd. Resultingly, the ΔHpp and Hc of Cu/CoFeB increase significantly after annealing. However, for the annealed Ru/CoFeB sample, the ΔHpp even decreases implying Ru is a proper under-layer material for CoFeB-based spintronic devices.
Tapered silicon nanowires for enhanced nanomechanical sensing
Authors: Malvar O. , Gil-Santos E. , Ruz J. J. , Ramos D. , Pini V. , Fernandez-Regulez M. , Calleja M. , Tamayo J. , San Paulo A.
Published: July 2013

We investigate the effect of controllably induced tapering on the resonant vibrations and sensing performance of silicon nanowires. Simple analytical expressions for the resonance frequencies of the first two flexural modes as a function of the tapering degree are presented. Experimental measurements of the resonance frequencies of singly clamped nanowires are compared with the theory. Our model is valid for any nanostructure with tapered geometry, and it predicts a reduction beyond two orders of magnitude of the mass detection limit for conical resonators as compared to uniform beams with the same length and diameter at the clamp.
Dielectric environment effect on carrier mobility of graphene double-layer structure
Authors: Hosono Kazuhiro , Wakabayashi Katsunori
Published: July 2013

We have theoretically studied the dielectric environment effect on the charged-impurity-limited carrier mobility of graphene double-layer structure (GDLS) on the basis of the Boltzmann transport theory. In this system, two graphene layers are separated by a dielectric barrier layer. It is pointed out that the carrier mobility strongly depends on the dielectric constant of the barrier layer when the interlayer distance becomes larger than the inverse of the Fermi wave vector. Moreover, the conditions to improve the charged-impurity-limited carrier mobility of the GDLS are evaluated.
Far infrared photoconductivity in a silicon based material: Vanadium supersaturated silicon
Authors: García-Hemme E. , García-Hernansanz R. , Olea J. , Pastor D. , del Prado A. , Mártil I. , González-Díaz G.
Published: July 2013

We have analyzed the spectral sub-bandgap photoresponse of silicon (Si) samples implanted with vanadium (V) at different doses and subsequently processed by pulsed-laser melting. Samples with V concentration clearly above the insulator-metal transition limit show an important increase of the photoresponse with respect to a Si reference sample. Their photoresponse extends into the far infrared region and presents a sharp photoconductivity edge that moves towards lower photon energies as the temperature decreases. The increase of the value of the photoresponse is contrary to the classic understanding of recombination centers action and supports the predictions of the insulator-metal transition theory.
Design and control of Ge-based metal-oxide-semiconductor interfaces for high-mobility field-effect transistors with ultrathin oxynitride gate dielectrics
Authors: Minoura Yuya , Kasuya Atsushi , Hosoi Takuji , Shimura Takayoshi , Watanabe Heiji
Published: July 2013

High-quality Ge-based metal-oxide-semiconductor (MOS) stacks were achieved with ultrathin oxynitride (GeON) gate dielectrics. An in situ process based on plasma nitridation of the base germanium oxide (GeO2) surface and subsequent metal electrode deposition was proven to be effective for suppressing electrical deterioration induced by the reaction at the metal/insulator interface. The electrical properties of the bottom GeON/Ge interface were further improved by both low-temperature oxidation for base GeO2 formation and high-temperature in situ vacuum annealing after plasma nitridation of the base oxide. Based on the optimized in situ gate stack fabrication process, very high inversion carrier mobility (μhole: 445 cm2/Vs, μelectron: 1114 cm2/Vs) was demonstrated for p- and n-channel Ge MOSFETs with Al/GeON/Ge gate stacks at scaled equivalent oxide thickness down to 1.4 nm.
Delayed discharge in alcohol-related dementia: consequences and possibilities for improvement
Authors: MacPhail Aleece , McDonough Michael , Ibrahim Joseph E.
Published: July 2013

Individuals with alcohol-related dementia (ARD) are over-represented among ‘difficult to discharge’ patients. ARD is associated with prolonged hospital stay and high rates of discharge at own risk. Risk factors for delayed discharge in patients with ARD include: a lack of appropriate medical and social support; multiple and complex needs; psychiatric symptoms; challenging behaviours; and an unmet need for appropriate residential care. Integration into present services is problematic and aged care is not an acceptable option for these patients. The present paper identifies three key possibilities to reduce the burden of prolonged hospitalisation of patients with ARD. These are: improved availability of specialised, multidisciplinary care pathways for patients with ARD, many of which could be developed out of existing services; the development of flexible supported-accommodation options, including harm minimisation, for the subset of patients who are not able to live independently; and improved practice in the emergency department (ED) to ensure timely administration of parenteral thiamine to all patients at risk of developing ARD.

What is known about the topic?
Overuse of acute services contributes to strain in the ED and high healthcare costs. ARD is a relatively common but frequently under-recognised condition that is disproportionately associated with delayed discharge, contributing to hospital ‘bed block’.

What does this paper add?
This paper provides a review of the relevant literature to identify contributing factors to delayed discharge in ARD, and strategies for improvement. Patients with ARD have several risk factors for delayed discharge, including a complex clinical profile, psychiatric symptoms, challenging behaviours, limited social support and a lack of appropriate accommodation. Negative discharge outcomes in ARD are reduced through improved administration of thiamine in the ED and the use of specialised services and care pathways, which can be developed out of existing services. For the subset of patients with highly complex needs who have undergone repeated cycles of detoxification and relapse, flexible, supported residential care with a harm-minimisation approach is cost effective and improves outcomes.

What are the implications for practitioners?
Increased awareness of ARD as a causative factor in delayed discharge and discharge at own risk is called for to allow identification of patients at risk. Improved use of thiamine in the ED and the development of clinical pathways and specialised services for patients with ARD are needed to address systematic gaps in service delivery and reduce the burden on acute care.
Referral pathways in colorectal cancer: an audit of surgeons’s records
Authors: Spigelman Allan D. , Pascoe Shane W. , Harris Mark F. , Beilby Justin J. , Crossland Lisa J. , Gett Rohan M. , Barton Michael B. , Jayasinghe Upali W.
Published: July 2013

Purpose. To explore the referral pathways of patients with newly diagnosed colorectal cancer to surgeons. Method. Australian surgeons from three states completed a questionnaire and their records were audited. Results. Thirty-three surgeons provided data on 530 patients seen in the preceding 12 months. The median time between colonoscopy and first surgical consult was 10 days, with 19% of patients waiting more than 28 days. After adjustment for clustering, no surgeon factors were associated with the number of days between colonoscopy and surgery. A report back to the general practitioner (GP) was found in 78% of patients’ records. This feedback varied between surgeons but none of the specific surgeon characteristics examined could explain this. Conclusion. Surgeons usually communicated with GP regardless of whether they were the referral source. However, communication with GP varied considerably among surgeons, with no evidence of a report to the GP in one-fifth of cases. What is known about the topic? Referral from general practice is the main pathway to specialist services in Australia. There has been little research describing factors that affect referral patterns, particularly following diagnosis of cancer to investigation for surgery. What does this paper add? A significant minority of GP were not informed of the referral for colonoscopy and did not receive a copy of the report. No surgeon factors were associated with the number of days between colonoscopy and surgery. What are the implications for practitioners? Although the referral pathway for colorectal cancer often begins in general practice, GP are not always fully informed of the pathways used and other important treatment decisions. Improved use of audit, dissemination of results and improved information exchange generally may all make a significant impact.
The evolving extension environment: implications for dairy scientists
Authors: Murphy C. , Nettle R. , Paine M.
Published: July 2013

This paper reviews current challenges in the Australian extension environment and provides a case for developing an adaptive extension platform for the dairy sector in Australia and New Zealand, to support evolving dairy farm systems. The variation in the public-sector engagement in extension, the diversity and number of extension providers and a relatively uncoordinated approach to define new extension roles, functions and professional requirements are current challenges for dairy extension across Australia. In the dairy sector, these challenges coincide with increasing demand for a responsive research, development, extension and education system in supporting the rapid evolution in dairy farming systems. Addressing these challenges is not an issue for extension alone; however, the required level of integration among research, development, extension and education in an environment where needs are changing and resources are scarce demands an engaged dairy-science profession. Drawing on international extension and agricultural innovation-system literature and earlier empirical research, the following three areas for development are proposed: (1) a professional development strategy that incorporates (i) an understanding of the new professional situations extension works within, (ii) leadership in cross-industry and cross-sector coordination concerning the nature of the changing client in research, development, extension and education system and (iii) clear priorities for extension; (2) a professional development plan that incorporates a workplace-learning approach; and (3) for extension specialists to be engaged in defining research priorities, the agenda for change and suitable pathways for change alongside other professional groups, including farming. This development agenda will, however, require an adaptive extension platform to advance these areas on behalf of farmers and public stakeholders.