bluuebunny/crossref_metadata_2025 huggingface dataset:
Temperature dependent dielectric function in the near-infrared to vacuum-ultraviolet ultraviolet spectral range of alumina and yttria stabilized zirconia thin films
Authors: Schmidt-Grund R. , Lühmann T. , Böntgen T. , Franke H. , Opper D. , Lorenz M. , Grundmann M.
Published: December 2013

The dielectric function of nano-/polycrystalline alumina and yttria stabilised zirconia thin films has been investigated in a wide spectral range from 1.0 eV to 7.5 eV and temperatures between 10 K and room temperature. In the near band-edge spectral range, we found a broad distribution of optical transitions within the band gap, the so-called Urbach absorption tail which is typical for amorphous or polycrystalline materials due to the lack of long range order in the crystal structure. The coupling properties of the electronic system to the optical phonon bath and thermal lattice vibrations strongly depend on the ratio of the spectral extent of these disorder states to the main phonon energy, which we correlate with the different crystalline structure of our samples. The films have been grown at room temperature and 650 °C by pulsed laser deposition.
Temperature-dependent structural property and power factor of n type thermoelectric Bi0.90Sb0.10 and Bi0.86Sb0.14 alloys
Authors: Malik K. , Das Diptasikha , Bandyopadhyay S. , Mandal P. , Deb A. K. , Srihari Velaga , Banerjee Aritra
Published: December 2013

Thermal variation of structural property, linear thermal expansion coefficient (α), resistivity (ρ), thermopower (S), and power factor (PF) of polycrystalline Bi1-xSbx (x = 0.10 and 0.14) samples are reported. Temperature-dependent powder diffraction experiments indicate that samples do not undergo any structural phase transition. Rietveld refinement technique has been used to perform detailed structural analysis. Temperature dependence of α is found to be stronger for Bi0.90Sb0.10. Also, PF for direct band gap Bi0.90Sb0.10 is higher as compared to that for indirect band gap Bi0.86Sb0.14. Role of electron-electron and electron-phonon scattering on ρ, S, and PF has been discussed.
Effect of plasmonic losses on light emission enhancement in quantum-wells coupled to metallic gratings
Authors: Sadi Toufik , Oksanen Jani , Tulkki Jukka
Published: December 2013

Recent experimental work has shown significant luminescence enhancement from near-surface quantum-well (QW) structures using metallic grating to convert surface plasmon (SP) modes into radiative modes. This work introduces a detailed theoretical study of plasmonic losses and the role of SPs in improving light extraction from grated light-emitting QW structures, using the fluctuational electrodynamics method. The method explains experimental results demonstrating emission enhancement, light scattering, and plasmonic coupling in the structures. We study these effects in angle-resolved reflectometry and luminescence setups in InGaN QW structures with silver grating. In contrast to experiments, our model allows direct calculation of the optical losses. The model predicts that the plasmonic coupling and scattering increases light emission by a factor of up to three compared to a flat semiconductor structure. This corresponds to reducing the absorption losses from approximately 93% in the ungrated metallic structure to 75% in the grated structure. Lower losses are associated with a significant emission enhancement enabled by the SPs of silver/GaN interfaces, which are present in the blue/green wavelength range, and can be optimized by carefully nanostructuring the metal layer and by the positioning of the QW. In general, the enhancement results from the interplay of mode scattering, conversion of SP energy directly into light, and losses in the metallic grating. The reported losses are very high when compared to the losses present in modern light-emitting diodes (LEDs). Albeit, our work provides tools needed for further optimization of plasmonic light extraction, eventually leading to highly efficient LEDs.
Large spin accumulation near a resistive interface due to spin-charge coupling
Authors: Chen Shuhan , Zou Han , Chui Siu-Tat , Ji Yi
Published: December 2013

We experimentally and theoretically investigate large spin signals in special nonlocal spin valves, where a vacuum break-junction is formed between the ferromagnetic spin detector and the nonmagnetic channel. The spin signals are clearly nonlocal and can be either non-inverted (meaning high nonlocal resistance for parallel states and low resistance for antiparallel states) or inverted. The magnitudes are significantly larger than those of standard metallic nonlocal devices with similar dimensions. The magnitudes and the signs can be understood by a theory of spin-charge coupling. The coupling between spin accumulation and charge accumulation across a resistive break junction leads to a large interfacial spin accumulation and thereby large spin signals. By analyzing the profiles of electrochemical potentials near the interface, we show that the sign of the spin signal depends on the values of spin-dependent conductivities, diffusion constants, and densities of states. The magnitude of the spin accumulation in the ferromagnetic spin detector can be higher than that in the nonmagnetic channel, enabling a rare amplification effect for spin accumulation.
Dynamic response and modeling of a carbon fiber— epoxy composite subject to shock loading
Authors: Alexander C. S. , Key C. T. , Schumacher S. C.
Published: December 2013

Unidirectional carbon fiber reinforced epoxy composite samples were tested to determine their response to one dimensional shock loading with the ultimate goal of developing a micromechanics based numerical model of the dynamic response. The material tested had high fiber content (62–68% by volume) and low porosity. Wave speeds for shocks traveling along the carbon fibers are significantly higher than for those traveling transverse to the fibers or through the bulk epoxy. As a result, the dynamic material response is dependent on the relative shock—fiber orientation; a complication that must be captured in the numerical models. Shocks traveling transverse to the fibers show an inelastic response consistent with the material constituent parts. Shocks traveling along the fiber direction travel faster and exhibit both elastic and plastic characteristics over the stress range tested; up to 15 GPa. Results presented detail the anisotropic material response, which is governed by different mechanisms along each of the two principle directions in the composite. Finally, numerical modeling of this response is described in detail and validated against the experimental data.
Quantum ground state effect on fluctuation rates in nano-patterned superconducting structures
Authors: Eftekharian Amin , Atikian Haig , Akhlaghi Mohsen K. , Jafari Salim Amir , Hamed Majedi A.
Published: December 2013

In this Letter, we present a theoretical model with experimental verifications to describe the abnormal behaviors of the measured fluctuation rates occurring in nano-patterned superconducting structures below the critical temperature. In the majority of previous works, it is common to describe the fluctuation rate by defining a fixed ground state or initial state level for the singularities (vortex or vortex-antivortex pairs), and then employing the well-known rate equations to calculate the liberation rates. Although this approach gives an acceptable qualitative picture, without utilizing free parameters, all the models have been inadequate in describing the temperature dependence of the rate for a fixed width or the width dependence of the rate for a fixed temperature. Here, we will show that by defining a current-controlled ground state level for both the vortex and vortex-antivortex liberation mechanisms, the dynamics of these singularities are described for a wide range of temperatures and widths. According to this study, for a typical strip width, not only is the vortex-antivortex liberation higher than the predicted rate, but also quantum tunneling is significant in certain conditions and can not be neglected.
A concept for a magnetic field detector underpinned by the nonlinear dynamics of coupled multiferroic devices
Authors: Beninato A. , Emery T. , Baglio S. , Andò B. , Bulsara A. R. , Jenkins C. , Palkar V.
Published: December 2013

Multiferroic (MF) composites, in which magnetic and ferroelectric orders coexist, represent a very attractive class of materials with promising applications in areas, such as spintronics, memories, and sensors. One of the most important multiferroics is the perovskite phase of bismuth ferrite, which exhibits weak magnetoelectric properties at room temperature; its properties can be enhanced by doping with other elements such as dysprosium. A recent paper has demonstrated that a thin film of Bi0.7Dy0.3FeO3 shows good magnetoelectric coupling. In separate work it has been shown that a carefully crafted ring connection of N (N odd and N ≥ 3) ferroelectric capacitors yields, past a critical point, nonlinear oscillations that can be exploited for electric (E) field sensing. These two results represent the starting point of our work. In this paper the (electrical) hysteresis, experimentally measured in the MF material Bi0.7Dy0.3FeO3, is characterized with the applied magnetic field (B) taken as a control parameter. This yields a “blueprint” for a magnetic (B) field sensor: a ring-oscillator coupling of N = 3 Sawyer-Tower circuits each underpinned by a mutliferroic element. In this configuration, the changes induced in the ferroelectric behavior by the external or “target” B-field are quantified, thus providing a pathway for very low power and high sensitivity B-field sensing.
Doping suppression and mobility enhancement of graphene transistors fabricated using an adhesion promoting dry transfer process
Authors: Cheol Shin Woo , Yoon Taeshik , Hun Mun Jeong , Yong Kim Taek , Choi Sung-Yool , Kim Taek-Soo , Jin Cho Byung
Published: December 2013

We present the facile dry transfer of graphene synthesized via chemical vapor deposition on copper film to a functional device substrate. High quality uniform dry transfer of graphene to oxidized silicon substrate was achieved by exploiting the beneficial features of a poly(4-vinylphenol) adhesive layer involving a strong adhesion energy to graphene and negligible influence on the electronic and structural properties of graphene. The graphene field effect transistors (FETs) fabricated using the dry transfer process exhibit excellent electrical performance in terms of high FET mobility and low intrinsic doping level, which proves the feasibility of our approach in graphene-based nanoelectronics.
Thermal rectification of electrons in hybrid normal metal-superconductor nanojunctions
Authors: Giazotto F. , Bergeret F. S.
Published: December 2013

We theoretically investigate heat transport in hybrid normal metal-superconductor (NS) nanojunctions focusing on the effect of thermal rectification. We show that the heat diode effect in the junction strongly depends on the transmissivity and the nature of the NS contact. Thermal rectification efficiency can reach up to ∼123% for a fully transmissive ballistic junction and up to 84% in diffusive NS contacts. Both values exceed the rectification efficiency of a NIS tunnel junction (I stands for an insulator) by a factor close to ∼5 and ∼3, respectively. Furthermore, we show that for NS point-contacts with low transmissivity, inversion of the heat diode effect can take place. Our results could prove useful for tailoring heat management at the nanoscale, and for mastering thermal flux propagation in low-temperature caloritronic nanocircuitry.
Tunable magnetic and magnetocaloric properties of La0.6Sr0.4MnO3 nanoparticles
Authors: Ehsani M. H. , Kameli P. , Ghazi M. E. , Razavi F. S. , Taheri M.
Published: December 2013

Nanoparticles of La0.6Sr0.4MnO3 with different particle sizes are synthesized by the nitrate-complex auto-ignition method. The structural and magnetic properties of the samples are investigated by X-Ray diffraction (XRD), Fourier transform infra-red (FT-IR) spectroscopy, transmission electron microscopy (TEM), and DC magnetization measurements. The XRD study coupled with the Rietveld refinement shows that all samples crystallize in a rhombohedral structure with the space group of R-3 C. The FT-IR spectroscopy and TEM images indicate formation of the perovskite structure with the average sizes of 20, 40, and 100 nm for the samples sintered at 700, 800, and 1100 °C, respectively. The DC magnetization measurements confirm tuning of the magnetic properties due to the particle size effects, e.g., reduction in the ferromagnetic moment and increase in the surface spin disorder by decreasing the particle size. The magnetocaloric effect (MCE) study based on isothermal magnetization vs. filed measurements in all samples reveals a relatively large MCE around the Curie temperature of the samples. The peak around the Curie temperature gradually broadens with reduction of the particle size. The data obtained show that although variations in the magnetic entropy and adiabatic temperature decrease by lowering the particle size, variation in the relative cooling power values are the same for all samples. These results make this material a proper candidate in the magnetic refrigerator application above room temperature at moderate fields.
Investigation of analog memristive switching of iron oxide nanoparticle assembly between Pt electrodes
Authors: Kim Jae-Deuk , Baek Yoon-Jae , Jin Choi Young , Jung Kang Chi , Ho Lee Hyun , Kim Hyun-Mi , Kim Ki-Bum , Yoon Tae-Sik
Published: December 2013

The analog memristive switching of iron oxide (γ-Fe2O3) nanoparticle assembly was investigated. The γ-Fe2O3 nanoparticles were chemically synthesized with ∼10 nm in diameter and assembled to be a continuous layer as a switching element in Pt/nanoparticles/Pt structure. It exhibited the analog switching that the resistance decreased sequentially as repeating −V sweeps and pulses while increased as applying +V. The capacitance-voltage curves presenting hysteresis with flatband voltage shift and distortion of their shapes with respect to the applied voltage supported the redistribution of space charges in nanoparticle assembly that might induce resistive switching. The polarity-dependent analog resistance change proportional to pulse voltage, time, and number of pulses was analogy to potentiation and depression of adaptive synaptic motion.
Link between depressions of melting temperature and Debye temperature in nanowires and its implication on Lindeman relation
Authors: Ghosh Sabyasachi , Raychaudhuri A. K.
Published: December 2013

In this paper we investigate a possible link between the depressions of the melting temperature Tm and the Debye Temperature θD in metal nanowires and check the validity of Lindeman relation on size reduction that connects these two physical quantities. From direct measurements of the θD and Tm, we show that the depressions in these physical quantities are such that ΔTm(d) and ΔθD2(d) have nearly the same inverse power law dependence on the diameter d (with the exponent ≈−0.6) for nanowires with diameters down to 30 nm. However the ratio θDTm1/2 is strictly not constant showing a reduction of nearly 9% when the sample size is taken from bulk to 30 nm. We discuss the physical significance of this observation and its impact on Lindeman criterion for melting.
Dependence of coercivity on length ratios in sub-micron Nd2Fe14B particles with rectangular prism shape
Authors: Thielsch J. , Suess D. , Schultz L. , Gutfleisch O.
Published: December 2013

Demagnetization curves of sub-micron Nd2Fe14B particles with rectangular prism shapes were simulated by micromagnetic simulations. Coercivity decreases with increasing particle thickness for same particle volumes. This unexpected behavior can be explained by different resulting angles of the total effective field when superimposing the applied field vector with the stray field vector at the point of the first reversal event. The angular dependence of the nucleation field follows a Stoner-Wohlfarth like behavior.
Magnetism of CoPd self-organized alloy clusters on Au(111)
Authors: Ohresser P. , Otero E. , Wilhelm F. , Rogalev A. , Goyhenex C. , Joly L. , Bulou H. , Romeo M. , Speisser V. , Arabski J. , Schull G. , Scheurer F.
Published: December 2013

Magnetic properties of gold-encapsulated CoxPd1−x self-organized nano-clusters on Au(111) are analyzed by x-ray magnetic circular dichroism for x = 0.5, 0.7, and 1.0. The clusters are superparamagnetic with a blocking temperature decreasing with increasing Pd concentration, due to a reduction of the out-of-plane anisotropy strength. No magnetic moment is detected on Pd in these clusters, within the detection limit, contrary to thick CoPd films. Both reduction of anisotropy and vanishing Pd moment are attributed to strain.
A dipole lattice model of switching characteristics in ferroelectric superlattices
Authors: Chew K.-H. , Zhou Y. , Ong L.-H. , Iwata M.
Published: December 2013

Using a one-dimensional lattice model, we studied the switching characteristics of superlattices formed out of alternate ferroelectric and dielectric layers. The two layers interact with each other through the dipole lattices located at interface. Switching characteristics of pulsed field such as hysteresis loop, differential electric susceptibility as a function of applied field, and switching current as a function of applied field were examined. Influence of various model parameters included field amplitude, viscosity, interaction between dipole lattices at interface, interaction between dipole lattices within the layer, layer thickness and dielectric stiffness on the switching characteristics were investigated in detail.
The effect of strain induced by Ag underlayer on saturation magnetization of partially ordered Fe16N2 thin films
Authors: Yang Meiyin , Allard Lawrence F. , Ji Nian , Zhang Xiaowei , Yu Guang-Hua , Wang Jian-Ping
Published: December 2013

Partially ordered Fe-N thin films were grown by a facing target sputtering process on the surface of a (001) Ag underlayer on MgO substrates. It was confirmed by x-ray diffraction that the Ag layer enlarged the in-plane lattice of the Fe-N thin films. Domains of the ordered α″-Fe16N2 phase within an epitaxial (001) α′-FexN phase were identified by electron diffraction and high-resolution aberration-corrected scanning transmission electron microscopy (STEM) methods. STEM dark-field and bright-field images showed the fully ordered structure of the α″-Fe16N2 at the atomic column level. High saturation magnetization(Ms) of 1890 emu/cc was obtained for α″-Fe16N2 on the Ag underlayer, while only 1500 emu/cc was measured for Fe-N on the Fe underlayer. The results are likely due to a tensile strain induced in the α″-Fe16N2 phase by the Ag structure at the interface.
Influence of rare earth doping on thermoelectric properties of SrTiO3 ceramics
Authors: Liu J. , Wang C. L. , Li Y. , Su W. B. , Zhu Y. H. , Li J. C. , Mei L. M.
Published: December 2013

Thermoelectric properties of SrTiO3 ceramics, doped with different rare earth elements, were investigated in this work. It's found that the ionic radius of doping elements plays an important role on thermoelectric properties: SrTiO3 ceramics doped with large rare earth ions (such as La, Nd, and Sm) exhibit large power factors, and those doped with small ions (such as Gd, Dy, Er, and Y) exhibit low thermal conductivities. Therefore, a simple approach for enhancing the thermoelectric performance of SrTiO3 ceramics is proposed: mainly doped with large ions to obtain a large power factor and, simultaneously, slightly co-doped with small ions to obtain a low thermal conductivity. Based on this rule, Sr0.8La0.18Yb0.02TiO3 ceramics were prepared, whose ZT value at 1 023 K reaches 0.31, increasing by a factor of 19% compared with the single-doped counterpart Sr0.8La0.2TiO3 (ZT = 0.26).
(2+1)-Dimensional manipulation of soft biological materials by opto-thermal diffusiophoresis
Authors: Maeda Yusuke T.
Published: December 2013

In a temperature gradient built by infrared laser heating, polyethylene glycol (PEG) of large concentration moves away from the hot region. The resulting concentration gradient of PEG creates entropic potential well and traps another solute of small concentration due to diffusiophoresis. Here we develop this method to work in two dimensional spaces and time. The steering of laser traps colloids, DNA, and living cells in designed two-dimensional patterns. By modulating laser intensity with time, the protein concentration is periodically controlled in tens of mHz. This method could be useful for a directed assembly of biological materials.
Random telegraph signals by alkanethiol-protected Au nanoparticles in chemically assembled single-electron transistors
Authors: Kano Shinya , Azuma Yasuo , Tanaka Daisuke , Sakamoto Masanori , Teranishi Toshiharu , Smith Luke W. , Smith Charles G. , Majima Yutaka
Published: December 2013

We have studied random telegraph signals (RTSs) in a chemically assembled single-electron transistor (SET) at temperatures as low as 300 mK. The RTSs in the chemically assembled SET were investigated by measuring the source–drain current, using a histogram of the RTS dwell time, and calculating the power spectrum density of the drain current–time characteristics. It was found that the dwell time of the RTS was dependent on the drain voltage of the SET, but was independent of the gate voltage. Considering the spatial structure of the chemically assembled SET, the origin of the RTS is attributed to the trapped charges on an alkanethiol-protected Au nanoparticle positioned near the SET. These results are important as they will help to realize stable chemically assembled SETs in practical applications.
The un-symmetric hybridization of graphene surface plasmons incorporating graphene sheets and nano-ribbons
Authors: Sun Yu , Zheng Zheng , Cheng Jiangtao , Liu Jianwei , Liu Jiansheng , Li Shuna
Published: December 2013

Un-symmetric hybridization of graphene surface plasmons (GSPs) in waveguides incorporating graphene nano-ribbons and an underlying graphene sheet is theoretically studied. By tuning the chemical potential of the sheet, the characteristics of the hybrid modes can be shifted from sheet-like toward ribbon-like. The performance of hybrid modes reaches the maximum when phase match is satisfied. Superior to symmetric ribbon pairs, the favorable hybrid modes can be tuned at their best states, while the other modes are suppressed. The hybrid waveguide GSPs mode supported by this structure could extend the propagation distance by 46% over that of the modes for ribbon pairs.
An electrically driven quantum dot-in-nanowire visible single photon source operating up to 150 K
Authors: Deshpande Saniya , Bhattacharya Pallab
Published: December 2013

We demonstrate electrically pumped single photon emission up to 150 K from a single InGaN quantum dot embedded in a GaN nanowire junction diode. The InGaN dot-in-nanowire p-n junctions were grown on silicon by molecular beam epitaxy. The exciton electroluminescence from individual dot-in-nanowires is in the green spectral range (λ ∼ 520 nm) and is detectable up to 150 K. Second order autocorrelation measurements performed at the exciton energy at an ambient temperature of 125 K show a background corrected g(2)(0) equal to 0.35, indicating dominant single photon emission. The steady state nanowire temperature under these conditions is estimated to be 150 K due to Joule heating induced by the large nanowire series resistance. Time resolved photoluminescence measurements yield an exciton radiative lifetime of 1.1 ns.
Scanning tunneling microscopy study of the superconducting properties of three-atomic-layer Pb films
Authors: Wang Yilin , Chen Mu , Li Zhi , Wang Lili , He Ke , Xue Qi-Kun , Ma Xucun
Published: December 2013

Ultrathin Pb films with a thickness of three monolayers (ML) were prepared on α-3×3Pb/Si(111) (Pb-SIC) substrate by molecular beam epitaxy. Despite significant defect scattering, low temperature scanning tunneling microscopy reveals a high superconducting transition temperature Tc of 6.9 K, compared with the bulk Tc (7.2 K). By applying external magnetic field, magnetic vortices were directly imaged, which demonstrates the robustness of superconductivity. By comparing to nearly free-standing Pb films on graphitized SiC (0001) substrate, we suggest that the higher Tc of 3 ML Pb films on Pb-SIC originates from the combined effects of quantum confinement and substrate-enhanced electron-phonon coupling.
Ge doped GaN with controllable high carrier concentration for plasmonic applications
Authors: Kirste Ronny , Hoffmann Marc P. , Sachet Edward , Bobea Milena , Bryan Zachary , Bryan Isaac , Nenstiel Christian , Hoffmann Axel , Maria Jon-Paul , Collazo Ramón , Sitar Zlatko
Published: December 2013

Controllable Ge doping in GaN is demonstrated for carrier concentrations of up to 2.4 × 1020 cm−3. Low temperature luminescence spectra from the highly doped samples reveal band gap renormalization and band filling (Burstein-Moss shift) in addition to a sharp transition. Infrared ellipsometry spectra demonstrate the existence of electron plasma with an energy around 3500 cm−1 and a surface plasma with an energy around 2000 cm−1. These findings open possibilities for the application of highly doped GaN for plasmonic devices.
Multiferroism and magnetoelectric coupling in (PbZr0.65Ti0.35O3)0.97–(BaFe12O19)0.03 ceramic composites
Authors: Guerra J. D. S. , Pal Madhuparna , Portugal R. J. , Cótica L. F. , Santos I. A. , Guo R. , Bhalla A. S.
Published: December 2013

The ferroelectric, magnetic, and magneto-electric properties of a PZT/Ba-hexaferrite (PbZr0.65Ti0.35O3/BaFe12O19) ceramic composite are reported. The expected rhombohedral-PZT and Ba-hexaferrite phases have been confirmed from structural and Rietveld refinement analyses, without additional undesired phases. Well-saturated ferroelectric and magnetic hysteresis loops confirmed the ferroelectric and magnetic nature of the study system, revealing enhanced characteristics when compared to those reported for typical multiferroics. The existence and enhancement of the magneto-electric response have been demonstrated by measuring the effect of the external DC magnetic field on the dielectric permittivity. The obtained results suggest an excellent candidate for room temperature multiferroic system with enhanced properties.
Improving daily output of global to direct solar irradiance models with ground measurements
Authors: Vindel J. M. , Polo J. , Antonanzas-Torres F.
Published: December 2013

A comparison of the DirIndex model for computing direct normal solar irradiance from global horizontal using different clear sky transmittance models is presented for four ground stations that belong to Baseline Surface Radiation Network (BSRN) and Aerosol RObotic NETwork (AERONET) networks. The results of DirInt model, which does not include any clear sky transmittance contribution, are also shown. The input for the different clear sky models selected (European Solar Radiation Atlas (ESRA), SOLar Irradiance Scheme (SOLIS) simplified, and Reference Evaluation of Solar Transmittance, 2 bands (REST2)) was generated from the original aerosol optical depth and water vapour measurements provided by AERONET. The results show different trends in the performance of the DirIndex model combined with the clear sky methods. An attempt to correct the trends to the proper one is finally proposed here and the improvement achieved is shown.
Substantial enhancement in intrinsic coercivity on M-type strontium hexaferrite through the increase in magneto-crystalline anisotropy by co-doping of group-V and alkali elements
Authors: Ahn Kyunghan , Ryu Byungki , Korolev Dmitry , Jae Kang Young
Published: December 2013

The effect of d1 impurity doping in Sr-hexaferrite (SrM) on the magnetic anisotropy is investigated. First-principles calculations revealed that group-V elements (V, Nb) are stabilized with co-doping of alkali elements. Na1+/K1+ doping at Sr2+-site is found to be critical to form the d1 impurities at Fe-site. Experimentally, Na–V doped SrM shows the intrinsic coercivity of ∼5.4 kOe, which is ∼300% enhancement compared to undoped SrM and comparable value to La–Co co-doped SrM. Finally, the spin-orbit coupling from non-vanishing angular momentum of d1 impurity in SrM should be a main factor for such a substantial improvement of intrinsic coercivity.
Atomic layer deposition of Al2O3 on germanium-tin (GeSn) and impact of wet chemical surface pre-treatment
Authors: Gupta Suyog , Chen Robert , Harris James S. , Saraswat Krishna C.
Published: December 2013

GeSn is quickly emerging as a potential candidate for high performance Si-compatible transistor technology. Fabrication of high-ĸ gate stacks on GeSn with good interface properties is essential for realizing high performance field effect transistors based on this material system. We demonstrate an effective surface passivation scheme for n-Ge0.97Sn0.03 alloy using atomic layer deposition (ALD) of Al2O3. The effect of pre-ALD wet chemical surface treatment is analyzed and shown to be critical in obtaining a good quality interface between GeSn and Al2O3. Using proper surface pre-treatment, mid-gap trap density for the Al2O3/GeSn interface of the order of 1012 cm−2 has been achieved.
What Explains Active Travel Behaviour? Evidence from Case Studies in the UK
Authors: Song Yena , Preston John M , Brand Christian
Published: December 2013

Walking and cycling are considered to be healthy and environmentally friendly modes of travel that can mitigate the harmful effects of motorised journeys. This study aims to reveal the individual and built environmental characteristics that are associated with these behaviours by examining the current level of walking and cycling for transport in three UK case-study areas. Obligatory and discretionary journeys were separately modelled under the assumption that different factors would affect mode choice. Over 70% of respondents incorporated walking and/or cycling into their weekly travel and about 15% had ridden bicycles at least once for nonrecreational purposes during the last seven days. We also found that more walking journeys were made for discretionary purposes compared with obligatory journeys whilst cycling was more common for obligatory journeys. Using the concept of the active travel share, we developed models analysing active travel behaviour. The results confirmed that both personal and household characteristics had clear associations with the tendency for nonmotorised travel. In particular, age, physical fitness, and vehicle ownership were significantly associated with active travel in all models. The built environment, on the other hand, had significant associations with active travel only for obligatory journeys with the exception of distance to the main activity site, which was found to be significant for both journey types.
The antigen 43 structure reveals a molecular Velcro-like mechanism of autotransporter-mediated bacterial clumping
Authors: Heras Begoña , Totsika Makrina , Peters Kate M. , Paxman Jason J. , Gee Christine L. , Jarrott Russell J. , Perugini Matthew A. , Whitten Andrew E. , Schembri Mark A.
Published: December 2013

Significance

Many persistent and chronic bacterial infections are associated with the formation of large cell aggregates and biofilms that are difficult to treat. This includes respiratory and urinary tract infections, infections on medical devices, and infections of the ear, gums, and heart. One mechanism used by bacteria to aggregate and form biofilms involves the expression of self-associating surface-located autotransporter proteins such as Antigen 43 (Ag43). Here we present the crystal structure of the functional passenger domain of Ag43 and demonstrate that its unique L-shaped structure drives the formation of cell aggregates via a molecular Velcro-like handshake mechanism. This work provides insight into the structure–function mechanisms that facilitate bacterial interactions during infection.
Morphological optimization for access to dual oxidants in biofilms
Authors: Kempes Christopher P. , Okegbe Chinweike , Mears-Clarke Zwoisaint , Follows Michael J. , Dietrich Lars E. P.
Published: December 2013

Significance

Principle questions in the field of biology concern the evolutionary advantages conferred by the multicellular lifestyle and by the formation of specific multicellular structures. In microbial biofilms, many cells cooperate to form distinct macroscopic patterns. Here we develop and apply a mathematical model, which incorporates empirical values, to show that the tall “ridges” produced by
Pseudomonas aeruginosa
colony biofilms maximize community growth via enhanced access to oxygen. Production of endogenous redox-active compounds, which mediate electron transfer from cells to oxygen, allows the formation of wider ridges. Externally supplied and endogenously produced oxidant availability controls feature geometry in a manner consistent with the model predictions for optimal geometry.
Positioning level 3
Authors: De Fina Anna
Published: December 2013

In this article I discuss the positive impact of the concept of positioning on identity studies, with particular reference to the analysis of narratives. I argue that the notion of positioning (particularly as developed in Bamberg’s 1997 three levels model), together with other constructs such as indexicality, has helped enormously in bridging the gap (particularly in interview based research) between interactionally-oriented and more traditionally oriented studies of narrative identities. I focus on level 3 positioning to argue that this construct allows for an approach to the construction of identity in discourse that occupies a middle ground between talk-in-interaction approaches that center exclusively on participant orientations at the local level and approaches that regard identity as basically determined by macro social processes and only manifested in discourse. To illustrate level 3 positioning I analyze a narrative taken from a corpus of stories of language conflict told by Latin American immigrant women to the US. I show that the narrator constructs her identity in relation to Discourses and ideologies about language and migration showing that interpretation of her positioning is based on close analysis of discourse at the local level, ethnographic data and understanding of macro social processes underlying power relations.
How to get a grip on identities-in-interaction
Authors: Deppermann Arnulf
Published: December 2013

This article advocates an understanding of ‘positioning’ as a key to the analysis of identities in interaction within the methodological framework of conversation analysis. Building on research by Bamberg, Georgakopoulou and others, a performative, interaction-based approach to positioning is outlined and compared to membership categorization analysis. An interactional episode involving mock stories to reveal and reproach an inadequate identity-claim of a co-participant is analysed both in terms of practices of membership categorization and positioning. It is concluded that membership categorization is a core element of positioning. Still, positioning goes beyond membership categorization in a) revealing biographical dimensions accomplished by narration and b) by uncovering implicit performative claims of identity, which are not established by categorization or description.
The play of metaphor
Authors: Soennichsen Susan , Morgan Mandy
Published: December 2013

This paper contributes to post-crisis, social constructionist psychological literature addressing mainstream psychology’s failure to engage in a relevant way with people’s everyday experiences. We work with a narrative psychology paradigm, focussing specifically on the element of metaphor as a useful way to come to terms with how our ‘selves’ and our interactions with others are sociolinguistically fashioned. We discuss an article by Ian Parker, in which personal accounts illuminate the linguistic embeddedness of psyches. To illustrate the value of metaphor for locating, and potentially transforming, interpretations in daily encounters, we consider a text by Bronwyn Davies and Rom Harré.
Becoming ‘I’
Authors: Duggan Shane B.
Published: December 2013

This article draws upon the orientation ‘blog’ posts from a current PhD study focusing on identity formation in young people undertaking their final year of secondary schooling within the Victorian Certificate of Education (VCE). It critically investigates how participants define the ‘purpose’ of their engagement with the study and the subjectivities they employ in those interactions. The online blogs designed for this study are intended to create a space in which participants are able to act a-synchronously and discuss their ‘day-to-day’ experiences of the VCE. A key focus of this paper is to explicate the nature of this activity as performative, that is, participants contributing to blogs actively consider the nature of their engagement and construct an implicit ‘Other’ — a relationship that is informed by the purpose for participating in the research. Utilising Deleuze’s concept of ‘becoming’ (1987) along with a narrative methods framework (Riessman, 2008), it investigates the concept of ‘Other’ and will trace the process of ‘becoming storyteller’ as an active performance in Blog participation.
Gettin’ together a posse
Authors: Abner Natasha
Published: December 2013

This article addresses the derivational relationship between attributive (nominal) and predicative (verbal) possessives marked by the poss sign in American Sign Language. Though traditionally classified as a possessive pronoun, a collection of morphological, syntactic, and semantic patterns is presented here as evidence that poss instead displays the distributional characteristics of a verbal predicate in the language. Classifying poss as a verbal predicate of possession explains its presence in predicative possessives and allows its attributive use to be derived from this underlying verbal structure as an instance of a prenominal reduced relative clause modifier. These base structures and their interaction with other components of the predicative and attributive domains explain the documented properties of attributive and predicative poss possessives, including, crucially, the sometimes divergent behaviors of these two possessive constructions.
wh-duplication in Italian Sign Language (LIS)
Authors: Branchini Chiara , Cardinaletti Anna , Cecchetto Carlo , Donati Caterina , Geraci Carlo
Published: December 2013

This paper focuses on those wh-questions in Italian Sign Language (LIS) featuring two lexically identical wh-signs. We show that wh1 (the first wh in linear order) is shorter than wh2 (the second wh in liner order). However, there is evidence that this different duration is due to a phrase-final lengthening, as wh2 occupies a sentence-final position. We therefore conclude that the two wh-signs are identical full copies: one sitting in Spec,CP on the right in LIS and the other one sitting in Spec,FocP on the left. We show that this construction yields a (focused) cleft question interpretation and we speculate that both copies are phonologically realized because the wh-signs in Spec,CP and Spec,FocP are the heads of two distinct chains. Finally, we distinguish identical wh-duplication from improper wh-duplication, namely cases where one of the two wh-elements is what we call qartichoke, an underspecified interrogative sign only surfacing in wh-questions.
person climbing up a tree
Authors: Pfau Roland , Steinbach Markus
Published: December 2013

Studies on sign language grammaticalization have demonstrated that most of the attested diachronic changes from lexical to functional elements parallel those previously described for spoken languages. To date, most of these studies are either descriptive in nature or embedded within functional-cognitive theories. In contrast, we take a generative perspective on sign language grammaticalization, adopting ideas by Roberts & Roussou (2003), who suggest that grammaticalization can be characterized as “reanalysis ‘upwards’ along the functional structure”. Following an overview of some of the attested modality-independent pathways, we zoom in on the grammaticalization of two types of agreement auxiliaries, the lexical sources of which are the verb give and the noun person. We argue that the grammaticalization of give-aux (in Greek Sign Language and Catalan Sign Language) follows directly from Roberts & Roussou’s model because a lexical verb is reanalyzed as an element which is merged in a structurally higher functional position (little v). The same is true for person, but this change has an additional modality-specific flavor. In spoken languages, agreement affixes typically enter the functional domain of V via cliticization. In contrast, in German Sign Language and Catalan Sign Language, person, after having been reanalyzed as a determiner-like element, ‘jumps’ directly from D into AgrO — most probably because it has the relevant spatial properties necessary to express agreement. Thus, grammaticalization in sign languages, while being structurally similar, allows for types of reanalysis that are not attested in spoken languages.
The point of agreement
Authors: Wilbur Ronnie B.
Published: December 2013

This paper reconsiders arguments suggesting that sign language analyses must proceed differently to take into account their gestural, iconic origins. Lillo-Martin & Meier (2011) argue that agreement is ‘person marking’, shown by directionality. Liddell (2003, 2011) argues that directional verbs move between locations associated with referents; given an infinite number of points, the forms of these verbs are unlistable, and therefore just gestural indicating; he claims that this makes sign languages different from spoken languages, a position that I will argue against. In their response, Lillo-Martin & Meier then agree that real-world referent locations are not part of grammar, so language must interface closely with the gestural system. In contrast, Quer (2011) argues that Liddell’s reasoning is flawed. I will present evidence to agree with Quer and argue that the linguistic discussion was prematurely derailed by noting the recent alternate analysis offered by Gökgöz (2013). There may well be a role for visual iconicity in relation to sign language structure, as demonstrated by Schlenker (2013a,b), but unless we pursue linguistic analysis further, we will never get a clear understanding of what that role is.
“He made her feel the beauty”
Authors: Sopčák Paul
Published: December 2013

In this paper, I discuss claims according to which literary reading may initiate a form of reflection that leads to “a shift in understanding” (e.g., Miall, 2006, p. 145). I focus particularly on reflection on one’s own finitude and draw on phenomenology to distinguish between two current models of “shifts in understanding” through reading literature: one involves shifts in abstract beliefs and the other involves shifts in embodied and experiential understandings. I argue that for some readers the engagement with literary texts not only moves them from the denial of death to the understanding of their own finitude, but that it also affords them an embodied experience of this finitude, as opposed to an abstract acknowledgement of it.
I begin by describing the difference between knowing about one’s death and the experience of one’s finitude. I then present a phenomenological alternative to current suggestions for how literary texts may initiate “a shift in understanding.” Finally, I present a series of empirical studies that investigate readers’ engagements with texts dealing with human finitude.
The therapeutic effects of narrative cinema through clarification
Authors: Khoo Guan Soon , Oliver Mary Beth
Published: December 2013

Media psychologists have found no empirical support for catharsis as emotional venting or purgation. However, the concept persists in the humanities and everyday use, particularly in beliefs about the presumed effects of catharsis on well-being. This study adjusts the conceptualization of catharsis to include a cognitive aspect, i.e., the clarification of emotion, and examines the health outcomes of the combination of exposure to drama and drama-induced self-reflection. An experiment (N = 152) was conducted to compare the therapeutic effects of cinematic and reading-based dramas. In a mediation analysis, improvements in general health and lowered levels of depression were found for cinematic drama exposure with self-reflection, compared to reading-based drama exposure with self-reflection; this relationship was mediated by identification and emotional self-efficacy. Our results provide preliminary evidence for the therapeutic benefits of cinematic human drama through an altered conception of catharsis. Implications for using media to facilitate emotional fitness and meaningful entertainment are discussed.
Aesthetic engagement during moments of suffering
Authors: Kuiken Don , Oliver Mary Beth
Published: December 2013

We provide a review of the literature concerning aesthetic engagement (especially with literature and film) during times of distress. The objective is to offer a conceptual framework for this fledging research area and to provide a context for several manuscripts on this topic included in a Special Issue of Scientific Study of Literature (Volume 3, Issue 2). Particular attention is given to processes that arguably are distinctively aesthetic, including (1) the role of prosodic/semantic structures in the generation of local aesthetic objects within a longer narrative; (2) the identification of an affective theme through reflective consideration of a series of separate — but resonant — local aesthetic objects; and (3) the consequent emergence of poignantly bivalent feelings tinged with loss. This framework invites reconsideration of the Aristotelian conception of catharsis (understood as clarification rather than purgation), as well as examination of how poignant aesthetic engagement invites revaluation of personal priorities during moments of vulnerability.
The Poincaré homology sphere and almost-simple knots in lens spaces
Authors: Baker Kenneth
Published: December 2013

Hedden defined two knots in each lens space that, through analogies with their knot Floer homology and doubly pointed Heegaard diagrams of genus one, may be viewed as generalizations of the two trefoils in

S
3

S^3

. Rasmussen showed that when the ‘left-handed’ one is in the homology class of the dual to a Berge knot of type VII, it admits an L-space homology sphere surgery. In this note we give a simple proof that these L-space homology spheres are always the Poincaré homology sphere.
There is no strictly singular centralizer on 𝐿_{𝑝}
Authors: Cabello Sánchez Félix
Published: December 2013

We prove that if

Φ
\Phi

is a centralizer on

L
p

L_p

, where

0
>
p
>
∞

0>p>\infty

, then there is a copy of

ℓ
2

\ell _2

inside

L
p

L_p

where

Φ
\Phi

is bounded. If

Φ
\Phi

is symmetric, then it is also bounded on a copy of

ℓ
q

\ell _q

, provided

0
>
p
>
q
>
2

0>p>q>2

. This shows that for a wide class of exact sequences

0
→

L
p

→
Z
→

L
p

→
0

0\to L_p\to Z\to L_p\to 0

the quotient map is not strictly singular, which generalizes a recent result of Jesús Suárez.
Is Timber Insurable? A Study of Wildfire Risks in the U.S. Forest Sector Using Spatio‐temporal Models
Authors: Chen Xuan , Goodwin Barry K. , Prestemon Jeffrey P.
Published: December 2013

In the U.S. forest products industry, wildfire is one of the leading causes of damage and economic losses. While individual wildfire behavior is well studied, new literature is emerging on broad‐scale (e.g., county‐level) wildfire risks. Our paper studies wildfire risks using crucial informational variables across both spatial units and time periods. Several statistical models are used to quantify the risks. We develop several maximum likelihood estimation methods to account for spatio‐temporal auto‐correlation in conditional risks. A group index insurance scheme is proposed, and its associated actuarially fair premium rates are estimated and presented. Implications for wildfire management policies are also discussed.