bluuebunny/crossref_metadata_2025 huggingface dataset:
Effective neural network‐based node localisation scheme for wireless sensor networks
Authors: Chuang Po‐Jen , Jiang Yi‐Jun
Published: February 2014

Wireless sensor networks usually obtain the location of an unknown node by measuring the distance between the unknown node and its neighbouring anchors. To enhance both localisation accuracy and localisation success rates, the authors introduce a new neural network‐based node localisation scheme. The new scheme is distinct because it can make the trained network model completely relevant to the topology via online training and correlated topology‐trained data and therefore attain more efficient application of the neural networks and more accurate inter‐node distance estimation. It is also distinct in adopting both received signal strength indication and hop counts to estimate the inter‐node distances, to improve the distance estimation accuracy as well as localisation accuracy at no additional cost. Experimental evaluation is conducted to measure the performance of the proposed scheme and other artificial intelligent‐based node localisation schemes. The results show that, at reasonable cost, the new scheme constantly produces higher localisation success rates and smaller localisation errors than other schemes.
Magnetic properties and magnetocaloric effect in the RCu2Si2 and RCu2Ge2 (R = Ho, Er) compounds
Authors: Mo Zhao-Jun , Shen Jun , Yan Li-Qin , Gao Xin-Qiang , Wang Li-Chen , Tang Cheng-Chun , Wu Jian-Feng , Sun Ji-rong , Shen Bao-Gen
Published: February 2014

The magnetic properties and magnetocaloric effect (MCE) in RCu2Si2 and RCu2Ge2 (R = Ho, Er) compounds have been investigated. All these compounds possess an antiferromagnetic (AFM)-paramagnetic (PM) transition around their respective Neel temperatures. The RCu2Si2 compounds undergo spin-glassy behavior above Neel temperature. Furthermore, a field-induced metamagnetic transition from AFM to ferromagnetic (FM) states is observed in these compounds. The calculated magnetic entropy changes show that all RCu2Si2 and RCu2Ge2 (R = Ho, Er) compounds, especially, ErCu2Si2 exhibits large MCEs with no thermal hysteresis and magnetic hysteresis loss. The value of −ΔSMmax reaches 22.8 J/Kg K for magnetic field changes from 0 to 5 T. In particular, for field changes of 1 and 2 T, the giant reversible magnetic entropy changes −ΔSMmax are 8.3 and 15.8 J/kg K at 2.5 K, which is lower than the boiling point of helium. The low-field giant magnetic entropy change, together with ignorable thermal hysteresis and field hysteresis loss of ErCu2Si2 compound is expected to have effective applications in low temperature magnetic refrigeration.
Control of magnetization reversal in oriented strontium ferrite thin films
Authors: Roy Debangsu , Anil Kumar P. S.
Published: February 2014

Oriented Strontium Ferrite films with the c axis orientation were deposited with varying oxygen partial pressure on Al2O3(0001) substrate using Pulsed Laser Deposition technique. The angle dependent magnetic hysteresis, remanent coercivity, and temperature dependent coercivity had been employed to understand the magnetization reversal of these films. It was found that the Strontium Ferrite thin film grown at lower (higher) oxygen partial pressure shows Stoner-Wohlfarth type (Kondorsky like) reversal. The relative importance of pinning and nucleation processes during magnetization reversal is used to explain the type of the magnetization reversal with different oxygen partial pressure during growth.
Time-resolved Kerr microscopy of coupled transverse domain walls in a pair of curved nanowires
Authors: Keatley P. S. , Yu W. , O'Brien L. , Read D. E. , Cowburn R. P. , Hicken R. J.
Published: February 2014

Time-resolved scanning Kerr microscopy has been used to directly observe magnetostatically coupled transverse domain walls (TDWs) in a pair of closely spaced, curved nanowires (NWs). Kerr images of the precessional response of the magnetic domain to either side of the TDW revealed the TDW as a minimum in the Kerr signal in the region of closest NW separation. When the TDWs were ejected from the NW pair, the minimum in the Kerr signal was no longer observed. By imaging this transition, the static de-coupling field was estimated to be in the range from 38 to 48 Oe in good agreement with a simple micromagnetic model. This work provides a novel technique by which DC and microwave assisted decoupling fields of TDWs may be explored in NW pairs of different width, separation, and curvature.
Fast shut-down protection system for radio frequency breakdown and multipactor testing
Authors: Graves T. P. , Hanson P. , Michaelson J. M. , Farkas A. D. , Hubble A. A.
Published: February 2014

Radio frequency (RF) breakdown such as multipactor or ionization breakdown is a device-limiting phenomenon for on-orbit spacecraft used for communication, navigation, or other RF payloads. Ground testing is therefore part of the qualification process for all high power components used in these space systems. This paper illustrates a shut-down protection system to be incorporated into multipactor/ionization breakdown ground testing for susceptible RF devices. This 8 channel system allows simultaneous use of different diagnostic classes and different noise floors. With initiation of a breakdown event, diagnostic signals increase above a user-specified level, which then opens an RF switch to eliminate RF power from the high power amplifier. Examples of this system in use are shown for a typical setup, illustrating the reproducibility of breakdown threshold voltages and the lack of multipactor conditioning. This system can also be utilized to prevent excessive damage to RF components in tests with sensitive or flight hardware.
Wave–vortex interactions in the nonlinear Schrödinger equation
Authors: Guo Yuan , Bühler Oliver
Published: February 2014

This is a theoretical study of wave–vortex interaction effects in the two-dimensional nonlinear Schrödinger equation, which is a useful conceptual model for the limiting dynamics of superfluid quantum condensates at zero temperature. The particular wave–vortex interaction effects are associated with the scattering and refraction of small-scale linear waves by the straining flows induced by quantized point vortices and, crucially, with the concomitant nonlinear back-reaction, the remote recoil, that these scattered waves exert on the vortices. Our detailed model is a narrow, slowly varying wavetrain of small-amplitude waves refracted by one or two vortices. Weak interactions are studied using a suitable perturbation method in which the nonlinear recoil force on the vortex then arises at second order in wave amplitude, and is computed in terms of a Magnus-type force expression for both finite and infinite wavetrains. In the case of an infinite wavetrain, an explicit asymptotic formula for the scattering angle is also derived and cross-checked against numerical ray tracing. Finally, under suitable conditions a wavetrain can be so strongly refracted that it collapses all the way onto a zero-size point vortex. This is a strong wave–vortex interaction by definition. The conditions for such a collapse are derived and the validity of ray tracing theory during the singular collapse is investigated.
Design of a transverse flux machine for power generation from seawaves
Authors: Franzitta Vicenzo , Viola Alessia , Trapanese Marco
Published: February 2014

In this paper, we present a transverse flux linear generator. We investigate the possibility to use this generator to extract energy from seawaves. We propose an optimization procedure that allows us to obtain an optimized design of the generator. The optimized design of the converter shows a power generation capability index much higher than other renewable systems.
Time resolved imaging of magnetization dynamics in hard disk writer yokes excited by bipolar current pulses
Authors: Yu W. , Keatley P. S. , Hicken R. J. , Gubbins M. A. , Czoschke P. J. , Lopusnik R.
Published: February 2014

A partially built hard disk writer structure with a NiFe/CoFe/Ru/NiFe/CoFe synthetic antiferromagnetic (SAF) yoke was studied by time and vector resolved scanning Kerr microscopy. All three time dependent components of the magnetization were recorded simultaneously as a bipolar current pulse with 1 MHz repetition rate was delivered to the coil. The component of magnetization parallel to the symmetry axis of the yoke was compared at the pole and above a coil winding in the centre of the yoke. The two responses are in phase as the pulse rises, but the pole piece lags the yoke as the pulse falls. The Kerr signal is smaller within the yoke than within the confluence region during pulse cycling. This suggests funneling of flux into the confluence region. Dynamic images acquired at different time delays showed that the relaxation is faster in the centre of the yoke than in the confluence region, perhaps due to the different magnetic anisotropy in these regions. Although the SAF yoke is designed to support a single domain to aid flux conduction, no obvious flux beaming was observed, suggesting the presence of a more complicated domain structure. The SAF yoke writer hence provides relatively poor flux conduction but good control of rise time compared to single layer and multi-layered yokes studied previously.
Magnons in one-dimensional k-component Fibonacci structures
Authors: Costa C. H. , Vasconcelos M. S.
Published: February 2014

We have studied the magnon transmission through of one-dimensional magnonic k-component Fibonacci structures, where k different materials are arranged in accordance with the following substitution rule: Sn(k)=Sn−1(k)Sn−k(k) (n≥k=0,1,2,…), where Sn(k) is the nth stage of the sequence. The calculations were carried out in exchange dominated regime within the framework of the Heisenberg model and taking into account the RPA approximation. We have considered multilayers composed of simple cubic spin-S Heisenberg ferromagnets, and, by using the powerful transfer-matrix method, the spin wave transmission is obtained. It is demonstrated that the transmission coefficient has a rich and interesting magnonic pass- and stop-bands structures, which depends on the frequency of magnons and the k values.
Excitonic recombination dynamics in non-polar GaN/AlGaN quantum wells
Authors: Rosales D. , Gil B. , Bretagnon T. , Guizal B. , Zhang F. , Okur S. , Monavarian M. , Izyumskaya N. , Avrutin V. , Özgür Ü. , Morkoç H. , Leach J. H.
Published: February 2014

The optical properties of GaN/Al0.15Ga0.85N multiple quantum wells are examined in 8 K–300 K temperature range. Both polarized CW and time resolved temperature-dependent photoluminescence experiment are performed so that we can deduce the relative contributions of the non-radiative and radiative recombination processes. From the calculation of the proportion of the excitonic population having wave vector in the light cone, we can deduce the variation of the radiative decay time with temperature. We find part of the excitonic population to be localized in concert with the report of Corfdir et al. (Jpn. J. Appl. Phys., Part 2 52, 08JC01 (2013)) in case of a-plane quantum wells.
Temperature-sensitive fluorescence of NaRETiO4:Pr3+ (RE = Y, Gd) based on the intervalence charge transfer between Pr3+ and Ti4+
Authors: Zhang Su , Liang Hongbin , Liu Yufeng
Published: February 2014

The temperature-dependent photoluminescence properties of efficient red-emitting phosphors NaYTiO4:Pr3+ and NaGdTiO4:Pr3+ are studied. Distinct temperature sensing characteristic of 1D2 emission is observed. The intensity of 1D2 emission is almost linearly decreased with the increasing temperature. The quenching process is induced by a low-lying Pr3+-Ti4+ intervalence charge transfer state (IVCT). Because the energies of IVCTs are different for two samples, different temperature sensitive ranges are observed.
An optimum approximation of n-point correlation functions of random heterogeneous material systems
Authors: Baniassadi M. , Safdari M. , Garmestani H. , Ahzi S. , Geubelle P. H. , Remond Y.
Published: February 2014

An approximate solution for n-point correlation functions is developed in this study. In the approximate solution, weight functions are used to connect subsets of (n-1)-point correlation functions to estimate the full set of n-point correlation functions. In previous related studies, simple weight functions were introduced for the approximation of three and four-point correlation functions. In this work, the general framework of the weight functions is extended and derived to achieve optimum accuracy for approximate n-point correlation functions. Such approximation can be utilized to construct global n-point correlation functions for a system when there exist limited information about these functions in a subset of space. To verify its accuracy, the new formulation is used to approximate numerically three-point correlation functions from the set of two-point functions directly evaluated from a virtually generated isotropic heterogeneous microstructure representing a particulate composite system. Similarly, three-point functions are approximated for an anisotropic glass fiber/epoxy composite system and compared to their corresponding reference values calculated from an experimental dataset acquired by computational tomography. Results from both virtual and experimental studies confirm the accuracy of the new approximation. The new formulation can be utilized to attain a more accurate approximation to global n-point correlation functions for heterogeneous material systems with a hierarchy of length scales.
Conceptual design of rotary magnetostrictive energy harvester
Authors: Park Young-Woo , Kang Han-Sam , Wereley Norman M.
Published: February 2014

This paper presents the conceptual design of a rotary magnetostrictive energy harvester (RMEH), which consists of one coil-wound Galfenol cantilever, with two PMs adhered onto the each end, and one permanent magnet (PM) array sandwiched between two wheels. Modeling and simulation are used to validate the concept. The proof-of-concept RMEH is fabricated by using the simulation results, and subjected to the experimental characterization. The experimental setup for the simulated characterization uses the motor-driven PM array to induce a forced vibration. It can be concluded that the theoretical prediction on the induced voltage agrees well with the experimental results and that induced voltage increases with rpm and with number of PMs. Future work includes optimization of RMEH performance via PM array configuration and development of prototype.
Controlled synthesis and defect dependent upconversion luminescence of Y2O3: Yb, Er nanoparticles
Authors: Lu Qipeng , Hou Yanbing , Tang Aiwei , Lu Yunzhang , Lv Longfeng , Teng Feng
Published: February 2014

Er3+ and Yb3+ co-doped Y2O3 nanoparticles have been prepared by using a coprecipitation method followed by a post-thermal-treatment, in which a surfactant (cetyltrimethylammonium bromide, CTAB) plays an important role in the size-controlling and upconversion luminescence tuning. The green (2H11/2, 4S3/2 → 4I15/2) and red emission (4F9/2 → 4I15/2) intensity can be effectively tuned by varying the surfactant concentration, which can induce the defects in the as-obtained products. The probability of quenching and nonradiative relaxation from 4F7/2, 2H11/2, and 4S3/2 to 4F9/2 could be increased as the number of defects introduced by the surfactant increases, and thus the ratio of red to green emission is also changed. The upconversion mechanism has been analyzed and discussed, which may be a new complement for upconversion luminescence.
Electrically tunable terahertz wave modulator based on complementary metamaterial and graphene
Authors: He Xun-jun , Li Teng-yue , Wang Lei , Wang Jian-min , Jiang Jiu-xing , Yang Guo-hui , Meng Fan-yi , Wu Qun
Published: February 2014

In this paper, we design and numerically demonstrate an electrically controllable light-matter interaction in a hybrid material/metamaterial system consisting of an artificially constructed cross cut-wire complementary metamaterial and an atomically thin graphene layer to realize terahertz (THz) wave modulator. By applying a bias voltage between the metamaterial and the graphene layer, this modulator can dynamically control the amplitude and phase of the transmitted wave near 1.43 THz. Moreover, the distributions of current density show that this large modulation depth can be attributed to the resonant electric field parallel to the graphene sheet. Therefore, the modulator performance indicates the enormous potential of graphene for developing sophisticated THz communication systems.
Thermally activated switching of perpendicular magnet by spin-orbit spin torque
Authors: Lee Ki-Seung , Lee Seo-Won , Min Byoung-Chul , Lee Kyung-Jin
Published: February 2014

We theoretically investigate the threshold current for thermally activated switching of a perpendicular magnet by spin-orbit spin torque. Based on the Fokker-Planck equation, we obtain an analytic expression of the switching current, in agreement with numerical result. We find that thermal energy barrier exhibits a quasi-linear dependence on the current, resulting in an almost linear dependence of switching current on the log-scaled current pulse-width even below 10 ns. This is in stark contrast to standard spin torque switching, where thermal energy barrier has a quadratic dependence on the current and the switching current rapidly increases at short pulses. Our results will serve as a guideline to design and interpret switching experiments based on spin-orbit spin torque.
Exchange bias beyond the superparamagnetic blocking temperature of the antiferromagnet in a Ni-NiO nanoparticulate system
Authors: Roy Aparna , De Toro J. A. , Amaral V. S. , Muniz P. , Riveiro J. M. , Ferreira J. M. F.
Published: February 2014

We report magnetic and exchange bias studies on Ni-NiO nanoparticulate systems synthesized by a two-step process, namely, chemical reduction of a Ni salt followed by air annealing of the dried precipitate in the temperature range 400–550 °C. Size of Ni and NiO crystallites as estimated from X–ray diffraction line broadening ranges between 10.5–13.5 nm and 2.3–4 nm, respectively. The magneto-thermal plots (M-T) of these bi-magnetic samples show a well developed peak in the vicinity of 130 K. This has been identified as the superparamagnetic blocking temperature “TB” of NiO. Interestingly, all samples exhibit exchange bias even above their respective NiO blocking temperatures, right up to 300 K, the maximum temperature of measurement. This is in contrast to previous reports since exchange bias requires the antiferromagnetic NiO to have a stable direction of its moment in order to pin the ferromagnet (Ni) magnetization, whereas such stability is unlikely above TB since the NiO is superparamagnetic, its moment flipping under thermal activation. Our observation is elucidated by taking into account the core-shell morphology of the Ni-NiO nanoparticles whereby clustering of some of these nanoparticles connects their NiO shells to form extended continuous regions of NiO, which because of their large size remain blocked at T > TB, with thermally stable spins capable of pinning the Ni cores and giving rise to exchange bias. The investigated samples may thus be envisaged as being constituted of both isolated core-shell Ni-NiO nanoparticles as well as clustered ones, with TB denoting the blocking temperature of the NiO shell of the isolated particles.
An efficient wireless power transfer system with security considerations for electric vehicle applications
Authors: Zhang Zhen , Chau K. T. , Liu Chunhua , Qiu Chun , Lin Fei
Published: February 2014

This paper presents a secure inductive wireless power transfer (WPT) system for electric vehicle (EV) applications, such as charging the electric devices inside EVs and performing energy exchange between EVs. The key is to employ chaos theory to encrypt the wirelessly transferred energy which can then be decrypted by specific receptors in the multi-objective system. In this paper, the principle of encrypted WPT is first revealed. Then, computer simulation is conducted to validate the feasibility of the proposed system. Moreover, by comparing the WPT systems with and without encryption, the proposed energy encryption scheme does not involve noticeable power consumption.
Dielectric properties of poly(vinylidene fluoride) nanocomposites filled with surface coated BaTiO3 by SnO2 nanodots
Authors: Zha Jun-Wei , Meng Xing , Wang Dongrui , Dang Zhi-Min , Li Robert K. Y.
Published: February 2014

SnO2 nanoparticles with an average diameter of about 4 nm were coated on the surface of BaTiO3 (BT) (∼100 nm) by chemical treatment. With the introduction of BT@SnO2, the dielectric permittivity of poly(vinylidene fluoride) (PVDF) composite was significantly increased to 90 at 103 Hz, which is ∼40% higher than that of the BT/PVDF composites. It was attributed to the enhanced interfacial polarization in the interlayers between BT and PVDF due to the addition of SnO2 nanodots. The distance of SnO2 nanodots on the adjacent BT surfaces is close enough for the electron transport in the matrix by tunneling effect. Besides, the semiconductive SnO2 leads to the weak insulating-conducting transition close to the percolation threshold.
Graphene growth on AlN templates on silicon using propane-hydrogen chemical vapor deposition
Authors: Michon A. , Tiberj A. , Vézian S. , Roudon E. , Lefebvre D. , Portail M. , Zielinski M. , Chassagne T. , Camassel J. , Cordier Y.
Published: February 2014

While the integration of graphene on semiconductor surfaces is important to develop new applications, epitaxial graphene has only been integrated on SiC substrates or 3C-SiC/Si templates. In this work, we explore the possibility of growing graphene on AlN/Si(111) templates. Using a chemical vapor deposition process with propane as the carbon source, we have obtained graphitic films (from 2 to 10 graphene layers) on AlN/Si(111) while preserving the morphology of the AlN layer beneath the graphitic film. This study is an important step for the integration of graphene with semiconductors other than SiC.
Leakage mechanisms in InAlN based heterostructures
Authors: Lugani L. , Py M. A. , Carlin J.-F. , Grandjean N.
Published: February 2014

We propose a model for leakage currents in Schottky contacts on InAlN/GaN heterostructures based on two distinct tunneling mechanisms. Our modeling relies on structural parameters, in particular, InAlN dielectric constant, interface polarization charges and Schottky barrier height, which are experimentally determined in the first part of our work. The first leakage mechanism is dominant in heterostructures with very thin (≤7 nm) InAlN barriers and consists in tunneling assisted by a deep level located 1.7 eV below the InAlN conduction band edge. We provide experimental evidence for this level through photocapacitance measurements. The second mechanism is on the other hand dominant in thicker InAlN layers and is linked to the appearance of highly doped regions where direct tunneling through the whole InAlN barrier is significantly enhanced. We also show that the two mechanisms may coexist for InAlN layers of intermediate thickness. Our findings confirm a progressive degradation of the InAlN material quality as the layer is grown thicker.
Impact of contact and access resistances in graphene field-effect transistors on quartz substrates for radio frequency applications
Authors: Ramón Michael E. , Movva Hema C. P. , Fahad Chowdhury Sk. , Parrish Kristen N. , Rai Amritesh , Magnuson Carl W. , Ruoff Rodney S. , Akinwande Deji , Banerjee Sanjay K.
Published: February 2014

High-frequency performance of graphene field-effect transistors (GFETs) has been limited largely by parasitic resistances, including contact resistance (RC) and access resistance (RA). Measurement of short-channel (500 nm) GFETs with short (200 nm) spin-on-doped source/drain access regions reveals negligible change in transit frequency (fT) after doping, as compared to ∼23% fT improvement for similarly sized undoped GFETs measured at low temperature, underscoring the impact of RC on high-frequency performance. DC measurements of undoped/doped short and long-channel GFETs highlight the increasing impact of RA for larger GFETs. Additionally, parasitic capacitances were minimized by device fabrication using graphene transferred onto low-capacitance quartz substrates.
An ab initio investigation of flexoelectric effect in ultrathin BaTiO3 nanotubes
Authors: Yin Binglun , Qu Shaoxing
Published: February 2014

We predict the existence of radial polarizations in single-layer-thick BaTiO3 nanotubes via ab initio calculations. The electric polarization is confirmed and calculated by a reliable method based on electrostatic potential analysis. And the polarization is found proportional to the strain gradient, which is induced by the bending deformation. The calculated effective transverse flexoelectric coefficient of BaTiO3 nanotubes possesses an order of −1 nC/m.
Structural, electronic, vibrational, and dielectric properties of LaBGeO5 from first principles
Authors: Shaltaf R. , Juwhari H. K. , Hamad B. , Khalifeh J. , Rignanese G.-M. , Gonze X.
Published: February 2014

Structural, electronic, vibrational, and dielectric properties of LaBGeO5 with the stillwellite structure are determined based on ab initio density functional theory. The theoretically relaxed structure is found to agree well with the existing experimental data with a deviation of less than 0.2%. Both the density of states and the electronic band structure are calculated, showing five distinct groups of valence bands. Furthermore, the Born effective charge, the dielectric permittivity tensors, and the vibrational frequencies at the center of the Brillouin zone are all obtained. Compared to existing model calculations, the vibrational frequencies are found in much better agreement with the published experimental infrared and Raman data, with absolute and relative rms values of 6.04 cm−1, and 1.81%, respectively. Consequently, numerical values for both the parallel and perpendicular components of the permittivity tensor are established as 3.55 and 3.71 (10.34 and 12.28), respectively, for the high-(low-)frequency limit.
Study of flow behaviors on single-cell manipulation and shear stress reduction in microfluidic chips using computational fluid dynamics simulations
Authors: Shen Feng , Li XiuJun , Li Paul C. H.
Published: February 2014

Various single-cell retention structures (SCRSs) were reported for analysis of single cells within microfluidic devices. Undesirable flow behaviors within micro-environments not only influence single-cell manipulation and retention significantly but also lead to cell damage, biochemical heterogeneity among different individual cells (e.g., different cell signaling pathways induced by shear stress). However, the fundamentals in flow behaviors for single-cell manipulation and shear stress reduction, especially comparison of these behaviors in different microstructures, were not fully investigated in previous reports. Herein, flow distribution and induced shear stress in two different single-cell retention structures (SCRS I and SCRS II) were investigated in detail to study their effects on single-cell trapping using computational fluid dynamics (CFD) methods. The results were successfully verified by experimental results. Comparison between these two SCRS shows that the wasp-waisted configuration of SCRS II has a better performance in trapping and manipulating long cylinder-shaped cardiac myocytes and provides a safer “harbor” for fragile cells to prevent cell damage due to the shear stress induced from strong flows. The simulation results have not only explained flow phenomena observed in experiments but also predict new flow phenomena, providing guidelines for new chip design and optimization, and a better understanding of the cell micro-environment and fundamentals of microfluidic flows in single-cell manipulation and analysis.
Coaxial probe for nuclear magnetic resonance diffusion and relaxation correlation experiments
Authors: Tang Yiqiao , Hürlimann Martin , Mandal Soumyajit , Paulsen Jeffrey , Song Yi-Qiao
Published: February 2014

A coaxial nuclear magnetic resonance (NMR) probe is built to measure diffusion and relaxation properties of liquid samples. In particular, we demonstrate the acquisition of two-dimensional (2D) distribution functions (T1-T2 and diffusion–T2), essential for fluids characterization. The compact design holds promise for miniaturization, thus enabling the measurement of molecular diffusion that is inaccessible to conventional micro-NMR setups. Potential applications range from crude oil characterization to biomolecular screening and detections.
Tunability of longitudinal wave band gaps in one dimensional phononic crystal with magnetostrictive material
Authors: Ding Rui , Su Xingliang , Zhang Juanjuan , Gao Yuanwen
Published: February 2014

Ways for controlling and adjusting the longitudinal wave band structures of one dimensional (1-D) rod phononic crystals with magnetostrictive material are theoretically investigated by the plane wave expansion method. Z-L model is adopted to accurately describe the constitutive relations of phononic crystal containing magnetostrictive material. Taking the magneto-mechanical coupling into account, the longitudinal wave band structures are calculated through the development of effective elastic constant, piezomagnetic constant, and magnetic permeability for magnetostrictive rod. Numerical results show that the longitudinal wave band gaps characteristics are significantly influenced by the applied static magnetic field and compressive pre-stress. Some new phenomena, such as the multi-peaks of the band gap widths corresponding to the varying filling fraction of the binary rod phononic crystal, are investigated.
Tunable piezoresistive sensors based on pencil-on-paper
Authors: Kang Ting-Kuo
Published: February 2014

Tunable piezoresistive sensors based on a drawing on paper with different grades of pencils are proposed. While an external mechanical strain is applied to U-shape resistors prepared by pencil drawings on paper, an increase in the gauge factor with an increase in the graphite resistance is found. The result is attributed to the tunneling effect between neighboring graphite during the drawing process, further suggesting that different-grade pencil drawings can tune the piezoresistive properties. Through many cycles of repeatedly applied and released force, the output voltage for an HB pencil was found to be more sensitive than that for a 9B pencil.
On the effect of finite magnetic relaxation on the magnetic particle imaging performance of magnetic nanoparticles
Authors: Dhavalikar Rohan , Rinaldi Carlos
Published: February 2014

Magnetic particle imaging is an emerging imaging technique where contrast is provided by the non-linear response of magnetic nanoparticle tracers to an applied magnetic field consisting of a scanned field free point. Commonly the magnetic response of the nanoparticles is assumed to be instantaneous, which is at odds with experimental evidence that finite relaxation affects both the signal and resolution provided by the tracers. Here, we apply rotational Brownian dynamics simulations to obtain insight into the effect of finite relaxation and of the conditions of the magnetic field on the performance of magnetic nanoparticle tracers used for magnetic particle imaging.
Contour Erasure and Filling-in: New Observations
Authors: Anstis Stuart , Greenlee Mark W.
Published: February 2014

Contour erasure is a newly established form of flicker adaptation that diminishes the saliency of object edges leading to their complete disappearance (Anstis, S. 2013. Journal of Vision, 13(2):25, 1–14). If these “disappeared” objects are then viewed on textured backgrounds, the observers experience filling-in, the illusory sense of background completion in the absence of physical input. In a series of observations, we demonstrate that contour erasure can greatly speed up the filling-in (or fading) of brightness. Based on these observations, we suggest that contour adaptation happens early in the magnocellular pathways.
Effects of Different Phases of Cigarette Smoke on Lipid Peroxidation and Membrane Structure in Liposomes
Authors: Palmina Nadezhda P. , Maltseva Elena L. , Chasovskaya Tatyana E. , Kasparov Valery V. , Bogdanova Nataliya G. , Menshov Valery A. , Trofimov Aleksei V.
Published: February 2014

This paper discloses for the first time the effects of the gas phase (GP) and the tar of cigarette smoke on lipid peroxidation (LPO) and on the structure of different lipid regions in liposomes. The LPO development was analysed in terms of the total unsaturation of lipids (double-bond, DB, content) and the formation of dienic conjugates (DC), ketodienes (KD), and malonic dialdehyde (MDA). As expected, the exposure of liposomes to either the GP or the tar led to a significant decrease in the DB content. However, the formation of oxidation products revealed different dynamics: MDA generation was inhibited, while the formation of DC and KD increased during the first few hours of the LPO development followed by its inhibition. The smoke constituents exhibited opposite effects on the structure of the lipid bilayer of liposomes: the GP markedly enhanced the microviscosity of liposomal membranes, whereas the tar caused a drastic lowering of microviscosity.
Correlates of condom use among males in North Sudan
Authors: Mohamed Badreldin A.
Published: February 2014

Objectives
In sub-Saharan Africa countries, HIV infections are transmitted primary through heterosexual contact. Correct and consistent condom use has been promoted as a method to prevent sexually transmissible infections, including HIV. The aim of this study was to assess and determine the factors influencing condom use in Khartoum, Sudan. Materials and methods: Out of the 45 voluntary counselling and testing centres in Khartoum region, 10 centres were selected. A random sample of 804 respondents aged 20–40 years was selected. Stepwise multiple logistic regression analysis was used to investigate the predictors of condom use. Results: About 12% of respondents reported using condoms consistently, 41.5% used them sporadically and 46.3% were nonusers. Most of the participants had problems with condom use (81.9%) and friends were the main source of condoms (72%). Knowledge about AIDS transmission, knowing someone who is infected with or had died of AIDS, experiencing condom problems, type of sexual partners, purchase embarrassment and education were the main predictors of condom use. Conclusions: Condom use among the Sudanese is low. Strategies to promote condom use should focus on price support for condoms by the government, expanded private sector condom distribution and the integration of sex education in school curriculums or via frequent discussion on television.
Surface shear inviscidity of soluble surfactants
Authors: Zell Zachary A. , Nowbahar Arash , Mansard Vincent , Leal L. Gary , Deshmukh Suraj S. , Mecca Jodi M. , Tucker Christopher J. , Squires Todd M.
Published: February 2014

Significance

Why some surfactant molecules promote long-living foams, while others are low foamers, remains mysterious. Experiments over the past 60 y have suggested that a surfactant’s surface shear viscosity (
η

S

) is correlated with the stability of the foam it produces, giving a widely held rule of thumb for foaming surfactants. Published
η

S

measurements for the heavily studied foaming surfactant sodium dodecyl sulfate (SDS), however, show almost no agreement, motivating a critical reevaluation. Using ferromagnetic microbutton probes, we perform the most sensitive and precise
η

S

measurements to date on SDS and a wide variety of soluble, small-molecule surfactants spanning different molecular characteristics and foamability. In fact, all soluble surfactants were found to have immeasurably small
η

S

, undercutting evidence for
η

S

–foam stability correlations.
Compounds vs. phrases
Authors: Kotowski Sven , Böer Katja , Härtl Holden
Published: February 2014

Nominal compounds and corresponding phrases provide a suitable test bed for inquiry into the interface and demarcations between syntax and morphology. In this article we show that the distinction between the two constructions is blurred from a theoretical perspective and investigate processing and cognitive aspects. After an examination of structural as well as semantic properties of the two types, we report on three studies (memorization, questionnaire, and reading time) that experimentally juxtapose German adjective-noun constructions of phrasal and morphological kinds. The results of these studies indicate cognitive differences between compounds and phrases. Considering alternative explanations, we argue that our data supports the view of two separated structural levels of grammar.
Semantic headedness and categorization of -cum- compounds
Authors: Martí Solano Ramón
Published: February 2014

Compounds such as actress-cum-model, pub-cum-hotel or military-cum-religious represent mainly an alternative construction to coordinative compounds of the singer-songwriter type. Although most of them are double-headed, some can show semantic left-headedness. We have detected six main semantic groups out of a corpus of 300 types of -cum- nominal compounds. They correspond, in descending order of frequency, to people’s professional or leisure activities; buildings, rooms, and other places; literary and audio-visual genres; pieces of furniture, clothes, and other objects; abstract nouns; and toponyms, and anthroponyms. Under the heading “People”, we consider two main subheadings: team-sports players and antonymous occupations or functions.
German plural doublets with and without meaning differentiation
Authors: Mörth Karlheinz , Dressler Wolfgang U.
Published: February 2014

This contribution studies the synchrony and diachrony of German plural variants. Plural doublets in the sense of overabundance must be restricted to variants with the same meaning used by one and the same speech community. But there is a preference for distinctiveness which assigns different pragmatic or semantic meanings to variants. This includes also a preference for iconic relationships between form and meaning. The assumption of a preference for biuniqueness appears to allow greater generalizations than the ideal of canonical paradigm forms.
The canonical function of the deponent  verbs in modern Greek
Authors: Zombolou Katerina , Alexiadou Artemis
Published: February 2014

The present paper discusses deponent verbs in Modern Greek. Deponents are claimed to be idiosyncratic, non-canonical verbs representing a mismatch between morphology and syntax/semantics, as they are intransitive verbs exhibiting a morphological form, non-active, without there being an active transitive counterpart. Since non-active morphology is standardly associated with de-transitivization, deponents are taken to be exceptional in this respect. We compiled a deponent-verb corpus of Modern Greek and examined its morphological, syntactic and semantic structure. The results of this study revealed that most deponent predicates are actually reflexives/reciprocals, anticausatives and passives; thus, they instantiate verbal alternations which typically surface with non-active morphological marking. For this reason, we conclude that the morphology of deponent verbs in Modern Greek has, contrary to their traditional definition, a canonical function.
Rethinking pedagogical assumptions in Canadian French immersion programs
Authors: Cummins Jim
Published: February 2014

Bilingual education and second language immersion programs have operated on the premise that the bilingual student’s two languages
should be kept rigidly separate. This paper argues that although it is appropriate to maintain largely separate
spaces for each language, it is also important to teach for transfer across languages. In other words, it is useful to explore
bilingual instructional strategies for teaching emergent bilingual students rather than assuming that monolingual instructional
strategies are inherently superior. The central rationale for integration across languages is that learning efficiencies can be
achieved when teachers explicitly draw their pupils’ attention to similarities and differences between their languages and
reinforce effective learning strategies in a coordinated way across languages. The paper explores the interplay between bilingual
and monolingual instructional strategies within French immersion programs, and bilingual education more generally, and suggests
concrete strategies for optimizing students’ bilingual and biliteracy development.
Exploring parental involvement and home-school relations in Irish immersion education
Authors: Kavanagh Lauren
Published: February 2014

This article describes qualitative findings from a mixed methods exploratory study of parental involvement in the heritage immersion context of Ireland. The research aimed to provide an in-depth analysis of the nature of home-school relations in this less usual educational setting. Three studies were designed in order to address this objective. Study 1 was a mixed methods investigation of the topic from the perspective of parents, involving a series of in-depth interviews and a self-report parental involvement survey. Study 2 was a qualitative exploration of educators’ experiences of parental involvement in an immersion setting. Study 3 was also qualitative in design and explored the topic at hand from the perspectives of immersion pupils. Findings indicated that there are distinct challenges to parental involvement in the context where the language of the home and the language of the school differ. Implications for practice in immersion schools are considered.
Detecting stories
Authors: Shenhav Shaul R.
Published: February 2014

The article argues that notwithstanding politicians’ desire to conceal from the public parts of the content of their indoor discussions, we nevertheless find ‘traces’ of their closed door debates in their public addresses.

The article suggests that we need to regard at least some of these traces as an inevitable part of the process of constructing political discourse. It provides a comparative analysis of in-camera and public political discourse in Israel, suggesting techniques for identifying unintentional disclosure of information. These techniques are applied to cases drawn from Israeli politics in which politicians have sought to conceal information in public and semi-public forums. Such scrutiny can not only help to sharpen our discernment of the hidden voices in political discourse, but also to understand a crucial mechanism for the construction of borders between confidential and public political discourse.
The Interaction between Consonant Types and Tone of the Chonnam Dialect of Korean
Authors: Kim Mi-Ryoung , Duanmu San
Published: February 2014

CINITIAL has the strongest effect on F0 among the four factors in cases of both pooled and individual data. Such an effect indicates that there is a strong correlation between the initial consonant type and tone: H following aspirated and tense consonants and LH following other consonants. Vowel has also an effect on F0 throughout the three temporal locations but its effect is much weaker than that of CINITIAL in size (Hz). However, the effect of Length and CFINAL on F0 is found to be almost negligible. Interactions between factors are found to be due to sporadic - presumably is linguistically unimportant - effects rather than to systematic difference.
A more through phonetic study suggests that there is a strong correlation between consonant types and tone, confirming Jun's earlier observation. For the fact that consonant types correlated with tone, the phonological discussion of Jun's analysis and an alternative analysis is provided. Jun explains the consonant type-tone interaction in terms of the phonologization of laryngeal effect at an intonational level of Korean phonology. However, in Jun's analysis, it still remains clear why there is a correlation if the laryngeal effect is phonologized. Contrary to Jun, the consonant types-tone interaction is well accounted for in the alternative analysis in terms of the voice hypothesis that lax consonants are underlyingly voiced. This interpretation has potential implications for tonogenesis.
Prosodic Structure and Perception of Korean Domain-initial Coronal Stops
Authors: Baker Kirk
Published: February 2014

Abstract
The perception of Korean's three-way voiceless stop contrast depends on the combination of a number of acoustic properties including closure duration, f
0, VOT and spectral slope. Production studies indicate that these same properties systematically vary according to a stop's position in the hierarchical prosodic structure of an utterance. This study investigated interactions between prosodic structure and the recognition of tense, lax and aspirated stops by using stimuli that contained stops produced at one position in the prosodic hierarchy cross-spliced into utterances at a different prosodic level. The results of the experiment showed that recognition of tense and aspirated stops remained high regardless of the degree of mismatch between the underlying prosodic position of a segment and the domain into which it was inserted. Misrecognition rates were higher for cross-spliced lax stops, and underlying Utterance and Intonation Phrase initial lax stops spliced into the syllable level were perceived as aspirated by a majority of listeners. These findings are interpreted in terms of Cho & Keating's (2001) study of domain-initial strengthening and the acoustic overlap that is observed between stop manner and prosodic position. These results are taken as preliminary evidence that could support Cho & Keating's (2001) suggestion that prosodically conditioned acoustic differences aid listeners in discerning intended phrasings.
Syntax and Morphology of Temporal-Aspectual Constructions in Korean
Authors: Pak Miok D.
Published: February 2014

Abstract. Verbal nouns in Korean exhibit properties of both nouns and verbs in that they assign both verbal and nominal cases to the arguments. Such mixed categorial behavior of verbal nouns is manifest only in certain environments, namely in the complement position of ha (a so-called light verb in Korean) and in the complement position of aspectual morphemes such as cwung 'during', cen 'before', and hwu 'after. Due to their mixed properties, the categorial status of verbal nouns in these environments has long been an issue of debate. This paper mainly discusses temporal-aspectual constructions, and proposes that they can be distinguished into three types, Types A, B, and C. Each type of temporal-aspectual construction has a different morpho-syntactic structure. The paper further claims that verbal nouns are inherently unspecified for their grammatical category (following Alexiadou 1997, 1998, Halle and Marantz 1993, and van Hout and Roeper 1998 among others), and different morpho-syntactic structures trigger different categorial status of verbal nouns in these environments. The complex categorial behavior of verbal nouns in temporal-aspectual constructions, then, is not only explained under the analysis proposed in this paper but is also expected.