bluuebunny/crossref_metadata_2025 huggingface dataset:
Axially symmetric dual‐reflectarray antennas
Authors: Yoon Ji Hwan , Yoon Young Joong , Lee Woo‐sang , So Joon‐ho
Published: June 2014

An axially symmetric dual‐reflectarray antenna is proposed. A main reflectarray is designed to mimic a paraboloidal main reflector, and a sub‐reflectarray is designed to mimic a hyperboloidal or an ellipsoidal sub‐reflector. The dual‐reflectarray antenna is more compact than the conventional curved dual reflector. The dual‐reflectarray antenna is designed at W‐band and compared with its equivalent Cassegrain antenna.
Thermal loss in high‐Q antennas
Authors: Caporal Del Barrio S. , Bahramzy P. , Svendsen S. , Jagielski O. , Pedersen G.F.
Published: June 2014

Tunable antennas are very promising for future generations of mobile communications, where antennas are required to cover a wide range of operating bands. This reported work was aimed at characterising the loss mechanism of tunable antennas. Tunable antennas typically exhibit a high quality factor (Q), which can lead to thermal loss due to the conductivity of the metal. The investigation shows that copper loss is non‐negligible for high‐Q values. In the proposed design, the copper loss is 2 dB, for a Q of 260 at 700 MHz.
Leader‐following consensus of second‐order non‐linear multi‐agent systems with directed intermittent communication
Authors: Huang Na , Duan Zhisheng , Zhao Yu
Published: June 2014

This study addresses leader‐following consensus problems for multi‐agent systems with second‐order non‐linear dynamics, under the assumption that each agent can only communicate with its neighbouring agents intermittently and the communication topology does not keep strongly connected or contain a spanning tree all along. Firstly, a class of distributed consensus algorithms are designed only based on the relative local intermittent information. Notions of completely and partly intermittent communication are proposed. Some sufficient conditions are derived for achieving consensus tracking under a general fixed topology with completely and partly intermittent communication. Then, as an extension, leader‐following consensus tracking is studied under time‐varying intermittent communication topologies. Finally, the effectiveness of the main results is illustrated by numerical simulations.
Stabilisation of open‐loop unstable plants under feedback control with distributed delays
Authors: Olgac Nejat , Kammer Ayhan Sebastian
Published: June 2014

A general class of linear time‐invariant feedback control systems with a distributed delay in the feedback line is treated. Differently from present literature, both limits of the delay are taken as non‐zero, which brings an interesting new perspective to the problem. The authors start with a theorem stating the equivalence of a general class of such distributed‐delay systems to a system with multiple discrete and independent delays. Although this connection has been recognised earlier, what is interesting and novel in this study is the first deployment of a paradigm called the cluster treatment of characteristic roots (CTCR). CTCR declares the stability outlook of the system in the space of the delays non‐conservatively and exhaustively. This capability forms a very important foundation over which the authors build further contributions. Firstly, the authors describe a systematic procedure to use distributed‐delayed feedback logic in order to stabilise an unstable plant. Secondly, we present an intriguing but very simple control strategy which is called sign inverting control. This seemingly paradoxical proposition (i.e. the inversion of the control polarity) imparts considerably enhanced robustness of the control system against the variations in delay bounds. Example case studies are provided to validate these features.
Hybrid optimisation method for optimal power flow using flexible AC transmission system devices
Authors: Huang Chao‐Ming , Huang Yann‐Chang
Published: June 2014

This study proposes a hybrid optimisation method for optimal power flow using a flexible AC transmission system (FACTS). The FACTS plays an important role in the dynamic stability and steady‐state control of power systems. This study achieves steady‐state control by determining the types and the optimal locations of the FACTS devices and their associated values in the transmission lines. To determine the optimal solutions to the FACTS allocation problem, a hybrid optimisation method that combines a harmony search algorithm and an ant system is proposed. The objective functions of power flow considered are the active power transmission loss, the performance index of the active power flow in the transmission lines and the performance index of the voltage difference between buses. The proposed method was verified on the IEEE 30‐bus and Taiwan Power Company 345 kV simplified systems. The results demonstrate that the proposed method improves the total transfer capability and provides better steady‐state control of power systems than existing methods do.
Multilevel cascaded transformerless inverter for connecting distributed‐generation sources to network
Authors: Ebadi Mazdak , Joorabian Mahmood , Moghani Javad Shokrollahi
Published: June 2014

There are many types of distributed‐generation (DG) sources that cannot be connected to the network directly and use an inverter‐based interface. In harmonic compensators [like active power filters (APFs)], the coupling transformer disrupts the compensation capability, therefore the transformerless inverter schemes have grown up in recent years. A new cascaded multilevel transformerless inverter topology is introduced in this study to connect the DG sources to power utility. The proposed circuit of this study can compensate the current harmonic of the non‐linear load (as in APF) and inject maximum possible active power as a DG source interface, simultaneously. A fixed gain called KC is obtained based on the load nature, and is used to adjust the set point of the inverter between two operating modes. Proposed scheme has been simulated in Matlab/Simulink to evaluate the circuit performance both in the maximum active power injection mode and the load harmonic compensation mode. Then a 2.2 kW single‐phase prototype of the circuit is used for experimental evaluation of the study. Both simulative and experimental results prove that such a circuit minimises the total harmonic distortion of the source side current to an acceptable margin, while injecting the maximum possible active power.
Design and implementation of a discrete‐time H‐infinity controller for uninterruptible power supply systems
Authors: Ribas Samuel Polato , Maccari Luiz Antonio , Pinheiro Humberto , de Oliveira Ricardo Coração de Leão Fontoura , Montagner Vinícius Foletto
Published: June 2014

This study provides a digital ℋ∞ controller design suitable for uninterruptible power supply inverters, yielding results that comply with the IEC 62040‐3 Standard. An augmented state space model for the system is given, taking into account the delay from the digital implementation of the control signal, and resonant controllers that ensure asymptotic tracking of the reference and good rejection of load disturbances. It is shown a case where an ℋ∞ optimal state feedback controller cannot provide good results because of the high control gains. To solve this problem, an ℋ∞ suboptimal controller is proposed, taking into account a prescribed bound for the ℋ∞ norm of the closed‐loop system and a parameter for limitation of the norm of the control gain vector. This suboptimal controller provides gains that lead to suitable results, complying with the constraints from the IEC 62040‐3 Standard. These results are compared with those from a widely used state feedback controller, providing superior performance, even with a much simpler design procedure. Simulation and experimental results have a good correspondence. Finally, the study illustrates that the ℋ∞ norm of the closed‐loop system can be seen as the output impedance over the frequency. From this information, using the small gain theorem, one can get the admittance value of the linear loads that preserve stability when connected to the uninterruptible power supply.
Complication sévère d’une contention collée linguale
mandibulaire
Authors: Pazera Pawel , Fudalej Piotr , Katsaros Christos
Published: June 2014

Le collage d’un fil torsadé souple sur les faces linguales des six dents antérieures
mandibulaires est une modalité de contention couramment utilisée. Les complications sont
rares mais peuvent être assez sérieuses pour provoquer des dégâts biologiques. Cet article
présente une complication sérieuse d’un fil de contention torsadé souple, collé en
lingual. Quatre ans après son traitement orthodontique, un homme de 20 ans a consulté pour
la rupture d’un fil de contention torsadé souple. L’examen clinique a montré un torque
radiculo-vestibulaire d’environ 35° d’une dent. Une image en tomographie volumique à faisceau conique
(Cone-Beam Computed Tomography ou CBCT) a montré que
la racine et l’apex de la dent étaient presque totalement hors de l’os du côté
vestibulaire. Étonnamment, la vitalité de la dent était préservée. La dent a été ramenée
presque jusqu’à sa position initiale; cliniquement, seule une récession gingivale a
persisté. Les orthodontistes et les dentistes devraient être conscients des complications
possibles des contentions collées. Les patients devraient être clairement informés de la
manière dont les problèmes peuvent être détectés à un stade précoce.
Le traitement orthopédique de la classe II squelettique par
l’association minivis +
ForsusTM : à propos d’un cas
Authors: Pujol Pierre
Published: June 2014

L’association d’une mécanique customisée et de deux outils comme les minivis et le
ForsusTM, jusque là utilisés indépendamment, a
obtenu des résultats inespérés pour la correction d’une classe II squelettique limite
chirurgicale. Le contrôle par les mini-implants de la bascule horaire du plan d’occlusion
fréquemment rapportée lors de l’utilisation des hyperpropulseurs sur appareils
multi-bagues permet d’apporter une meilleure réponse mandibulaire.
Frontal Sinus Obliteration with Iliac Crest Bone Grafts. Review of 8 Cases
Authors: Monnazzi Marcelo , Gabrielli Marisa , Pereira-Filho Valfrido , Hochuli-Vieira Eduardo , de Oliveira Henrique , Gabrielli Mario
Published: June 2014

This study evaluated postoperative results of 8 cases of frontal sinus fractures treated by frontal sinus obliteration with autogenous bone from the anterior iliac crest. Patients and methods: The medical charts of patients sequentially treated for frontal sinus fractures by obliteration with autogenous cancellous iliac crest bone in the Oral and Maxillofacial Surgery Division of this institution were reviewed. From those, eight had complete records and adequately described long-term follow-up. All were operated by the same surgical team. Those patients were recalled and independently evaluated by 2 examiners. Radiographs and/or CT scans were available for this evaluation. Associated fractures and complications were noted. The average postoperative follow-up was 7 years, ranging from 3 to 16 years. The main complication was infection. Four patients (50%) had uneventful long-term follow-ups and four (50%) experienced complications requiring reoperation. Based on the studied sample studied the authors conclude that the obliteration with autogenous bone presented a high percentage of complications in this series.
Potential energy landscape of the two-dimensional XY model: Higher-index stationary points
Authors: Mehta D. , Hughes C. , Kastner M. , Wales D. J.
Published: June 2014

The application of numerical techniques to the study of energy landscapes of large systems relies on sufficient sampling of the stationary points. Since the number of stationary points is believed to grow exponentially with system size, we can only sample a small fraction. We investigate the interplay between this restricted sample size and the physical features of the potential energy landscape for the two-dimensional XY model in the absence of disorder with up to N = 100 spins. Using an eigenvector-following technique, we numerically compute stationary points with a given Hessian index I for all possible values of I. We investigate the number of stationary points, their energy and index distributions, and other related quantities, with particular focus on the scaling with N. The results are used to test a number of conjectures and approximate analytic results for the general properties of energy landscapes.
Path integral Liouville dynamics for thermal equilibrium systems
Authors: Liu Jian
Published: June 2014

We show a new imaginary time path integral based method—path integral Liouville dynamics (PILD), which can be derived from the equilibrium Liouville dynamics [J. Liu and W. H. Miller, J. Chem. Phys. 134, 104101 (2011)] in the Wigner phase space. Numerical tests of PILD with the simple (white noise) Langevin thermostat have been made for two strongly anharmonic model problems. Since implementation of PILD does not request any specific form of the potential energy surface, the results suggest that PILD offers a potentially useful approach for general condensed phase molecular systems to have the two important properties: conserves the quantum canonical distribution and recovers exact thermal correlation functions (of even nonlinear operators, i.e., nonlinear functions of position or momentum operators) in the classical, high temperature, and harmonic limits.
High-reliability passivation of hydrogen-terminated diamond surface by atomic layer deposition of Al2O3
Authors: Daicho Akira , Saito Tatsuya , Kurihara Shinichiro , Hiraiwa Atsushi , Kawarada Hiroshi
Published: June 2014

Although the two-dimensional hole gas (2DHG) of a hydrogen-terminated diamond surface provides a unique p-type conducting layer for high-performance transistors, the conductivity is highly sensitive to its environment. Therefore, the surface must be passivated to preserve the 2DHG, especially at high temperature. We passivated the surface at high temperature (450 °C) without the loss of C-H surface bonds by atomic layer deposition (ALD) and investigated the thermal reliability of the Al2O3 film. As a result, C-H bonds were preserved, and the hole accumulation effect appeared after the Al2O3 deposition by ALD with H2O as an oxidant. The sheet resistivity and hole density were almost constant between room temperature and 500 °C by the passivation with thick Al2O3 film thicker than 38 nm deposited by ALD at 450 °C. After the annealing at 550 °C in air The sheet resistivity and hole density were preserved. These results indicate the possibility of high-temperature application of the C-H surface diamond device in air. In the case of lower deposition temperatures, the sheet resistivity increased after air annealing, suggesting an insufficient protection capability of these films. Given the result of sheet resistivity after annealing, the increase in the sheet resistivity of these samples was not greatly significant. However, bubble like patterns were observed in the Al2O3 films formed from 200 to 400 °C by air annealing at 550 °C for 1 h. On the other hand, the patterns were no longer observed at 450 °C deposition. Thus, this 450 °C deposition is the sole solution to enabling power device application, which requires high reliability at high temperatures.
A Guillemin type E pulse forming network as the driver for a pulsed, high density plasma source
Authors: Rathod Priyavandna J. , Anitha V. P. , Sholapurwala Z. H. , Saxena Y. C.
Published: June 2014

A Guillemin type E pulse forming network (PFN) has been designed, developed, and tested for its application in generating high density (∼1 × 1018 m−3) plasmas. In the present study, plasma thus generated is utilized to investigate the interaction of high power microwaves (HPMs) with plasma in an experimental architecture known as SYMPLE (System for Microwave PLasma Experiment). Plasma discharges of ∼100 μs (max) duration are to be produced, by delivering energy of 5 kJ stored in a PFN to the plasma source, a washer gun. The output of the PFN, in terms of its rise time, flat top and amplitude, needs to be tailored, depending on the experimental requirements. An ignitron (NL8900) trigger generator (ITG) is developed in-house to control the PFN discharge through the gun. This ITG is also to be used in a circuit that synchronizes the HPM and plasma shots, to ensure that HPM-plasma interaction takes place during a temporal regime where appropriate parametric conditions are satisfied. Hence it is necessary to retain the jitter within ±2.5 μs. Further, requirement on plasma quiescence (∼10%) necessitates maintaining the ripple within 5%. The developmental work of the PFN, keeping in view the above criteria and the test results, is presented in this paper. The parameters of the PFN have been analytically approximated and verified with PSPICE simulation. The test results presented include rise time ∼5–8 μs, flat top variable in the range 20–100 μs, ripple within ∼1.5%, and jitter within ±2.5 μs, producing quiescent (<10%) plasma discharge meeting the experimental requirements.
Computational study on ice growth inhibition of Antarctic bacterium antifreeze protein using coarse grained simulation
Authors: Nguyen Hung , Le Ly , Ho Tu Bao
Published: June 2014

Antarctic bacterium antifreeze proteins (AFPs) protect and support the survival of cold-adapted organisms by binding and inhibiting the growth of ice crystals. The mechanism of the anti-freezing process in a water environment at low temperature of Antarctic bacterium AFPs remains unclear. In this research, we study the effects of Antarctic bacterium AFPs by coarse grained simulations solution at a temperature range from 262 to 273 K. The results indicated that Antarctic bacterium AFPs were fully active in temperatures greater than 265 K. Additionally, the specific temperature ranges at which the water molecules become completely frozen, partially frozen, and not frozen were identified.
Heat kernel for flat generalized Laplacians with anisotropic scaling
Authors: Mamiya A. , Pinzul A.
Published: June 2014

We calculate the closed analytic form of the solution of heat kernel equation for the anisotropic generalizations of flat Laplacian. We consider a UV as well as UV/IR interpolating generalizations. In all cases, the result can be expressed in terms of Fox-Wright psi-functions. We perform different consistency checks, analytically reproducing some of the previous numerical or qualitative results, such as spectral dimension flow. Our study should be considered as a first step towards the construction of a heat kernel for curved Hořava-Lifshitz geometries, which is an essential ingredient in the spectral action approach to the construction of the Hořava-Lifshitz gravity.
Local vibrational dynamics of hematite (α-Fe2O3) studied by extended x-ray absorption fine structure and molecular dynamics
Authors: Sanson A. , Mathon O. , Pascarelli S.
Published: June 2014

The local vibrational dynamics of hematite (α-Fe2O3) has been investigated by temperature-dependent extended x-ray absorption fine structure spectroscopy and molecular dynamics simulations. The local dynamics of both the short and long nearest-neighbor Fe–O distances has been singled out, i.e., their local thermal expansion and the parallel and perpendicular mean-square relative atomic displacements have been determined, obtaining a partial agreement with molecular dynamics. No evidence of the Morin transition has been observed. More importantly, the strong anisotropy of relative thermal vibrations found for the short Fe–O distance has been related to its negative thermal expansion. The differences between the local dynamics of short and long Fe–O distances are discussed in terms of projection and correlation of atomic motion. As a result, we can conclude that the short Fe–O bond is stiffer to stretching and softer to bending than the long Fe–O bond.
Direct current dielectric barrier assistant discharge to get homogeneous plasma in capacitive coupled discharge
Authors: Du Yinchang , Li Yangfang , Cao Jinxiang , Liu Yu , Wang Jian , Zheng Zhe
Published: June 2014

In this paper, we propose a method to get more homogeneous plasma in the geometrically asymmetric capacitive coupled plasma (CCP) discharge. The dielectric barrier discharge (DBD) is used for the auxiliary discharge system to improve the homogeneity of the geometrically asymmetric CCP discharge. The single Langmuir probe measurement shows that the DBD can increase the electron density in the low density volume, where the DBD electrodes are mounted, when the pressure is higher than 5 Pa. By this manner, we are able to improve the homogeneity of the plasma production and increase the overall density in the target volume. At last, the finite element simulation results show that the DC bias, applied to the DBD electrodes, can increase the homogeneity of the electron density in the CCP discharge. The simulation results show a good agreement with the experiment results.
Steady fall of isothermal, resistive-viscous, compressible fluid across magnetic field
Authors: Low B. C. , Egan A. K.
Published: June 2014

This is a basic MHD study of the steady fall of an infinite, vertical slab of isothermal, resistive-viscous, compressible fluid across a dipped magnetic field in uniform gravity. This double-diffusion steady flow in unbounded space poses a nonlinear but numerically tractable, one-dimensional (1D) free-boundary problem, assuming constant coefficients of resistivity and viscosity. The steady flow is determined by a dimensionless number μ1 proportional to the triple product of the two diffusion coefficients and the square of the linear total mass. For a sufficiently large μ1, the Lorentz, viscous, fluid-pressure, and gravitational forces pack and collimate the fluid into a steady flow of a finite width defined by the two zero-pressure free-boundaries of the slab with vacuum. The viscous force is essential in this collimation effect. The study conjectures that in the regime μ1→0, the 1D steady state exists only for μ1∈Ω, a spectrum of an infinite number of discrete values, including μ1 = 0 that corresponds to two steady states, the classical zero-resistivity static slab of Kippenhahn and Schlüter [R. Kippenhahn and A. Schlüter, Z. Astrophys. 43, 36 (1957)] and its recent generalization [B. C. Low et al., Astrophys. J. 755, 34 (2012)] to admit an inviscid resistive flow. The pair of zero-pressure boundaries of each of the μ1→0 steady-state slabs are located at infinity. Computational evidence suggests that the Ω steady-states are densely distributed around μ1 = 0, as an accumulation point, but are sparsely separated by open intervals of μ1-values for which the slab must be either time-dependent or spatially multi-dimensional. The widths of these intervals are vanishingly small as μ1→0. This topological structure of physical states is similar to that described by Landau and Liftshitz [L. D. Landau and E. M. Lifshitz, Fluid Mechanics (Addison-Wesley, Reading, MA, 1959)] to explain the onset of hydrodynamic turbulence. The implications of this MHD study are discussed, with an interest in the prominences in the solar atmosphere and the interstellar clouds in the Galaxy.
Enhanced thermal stability of phosphate capped magnetite nanoparticles
Authors: Muthukumaran T. , Philip John
Published: June 2014

We have studied the effect of phosphate capping on the high temperature thermal stability and magnetic properties of magnetite (Fe3O4) nanoparticles synthesized through a single-step co-precipitation method. The prepared magnetic nanoparticles are characterized using various techniques. When annealed in air, the phosphate capped nanoparticle undergoes a magnetic to non-magnetic phase transition at a temperature of 689 °C as compared to 580 °C in the uncoated nanoparticle of similar size. The observed high temperature phase stability of phosphate capped nanoparticle is attributed to the formation of a phosphocarbonaceous shell over the nanoparticles, which acts as a covalently attached protective layer and improves the thermal stability of the core material by increasing the activation energy. The phosphocarbonaceous shell prevents the intrusion of heat, oxygen, volatiles, and mass into the magnetic core. At higher temperatures, the coalescence of nanoparticles occurs along with the restructuring of the phosphocarbonaceous shell into a vitreous semisolid layer on the nanoparticles, which is confirmed from the small angle X-ray scattering, Fourier transform infra red spectroscopy, and transmission electron microscopy measurements. The probable mechanism for the enhancement of thermal stability of phosphocarbonaceous capped nanoparticles is discussed.
Modulational instability and associated rogue structures of slow magnetosonic wave in Hall magnetohydrodynamic plasmas
Authors: Panwar Anuraj , Ryu Chang-Mo
Published: June 2014

The modulational instability and associated rogue structures of a slow magnetosonic wave are investigated for a Hall magnetohydrodynamic plasma. Nonlinear Schrodinger equation is obtained by using the multiple scale method, which shows a modulationally unstable slow magnetosonic mode evolving into bright wavepackets. The dispersive effects induced by the Hall electron current increase with the increase in plasma β and become weaker as the angle of propagation increases. The growth rate of the modulational instability also increases with the increase in plasma β. The growth rate is greatest for the parallel propagation and drops to zero for perpendicular propagation. The envelope wavepacket of a slow magnetosonic is widened with less oscillations as plasma β increases. But the wavepacket becomes slightly narrower and more oscillatory as the angle of propagation increases. Further a non-stationary envelope solution of the Peregrine soliton is analyzed for rogue waves. The Peregrine soliton contracts temporally and expands spatially with increase in plasma β. However, the width of a slow magnetosonic Peregrine soliton decreases both temporally and spatially with increase of the propagation angle.
Local thickness determination of thin insulator films via localized states
Authors: Steurer W. , Gross L. , Meyer G.
Published: June 2014

We propose measuring the lifetime of localized states below the conduction band to determine the local thickness of thin insulating films using scanning tunneling microscopy. The lifetime, which is a characteristic fingerprint of the film thickness, is inversely proportional to the saturation value of the tunnel current through the localized state at close tip-sample separation and is readily measured using scanning tunneling spectroscopy. We demonstrate the method for 5–11 monolayer thick NaCl films grown on Cu(111).
A three-dimensional cellular automata evacuation model with dynamic variation of the exit width
Authors: You Lei , Zhang Chi , Hu Jun , Zhang Zhiheng
Published: June 2014

In view of the existing two-dimensional pedestrian flow evacuation model which could not consider stair factors, a novel evacuation model is proposed by combining with three-dimensional cellular automata. The model gives a calculation method of probability of pedestrian movement based on the attraction, the congestion degree, the repulsive force, and the friction force. At the same time, simulation analysis is done combined with the real evacuation data and the experiment platform. Moreover, it further studies relationships of the evacuation time, the system average rate, exit width, and the initial density of pedestrians, in order to get pedestrians flow characteristics which are more in line with the real situation. The results show that the evacuation time will remain the same when the exit width increases to a certain extent. When the pedestrian density is relatively smaller in the evacuation space, the location attraction coefficient and the congestion degree coefficient play a decisive role for movement efficiency. However, when the pedestrian density is larger, the repulsive force coefficient and the friction force coefficient are decisive factors for the movement efficiency.
Effect of Z1/2, EH5, and Ci1 deep defects on the performance of n-type 4H-SiC epitaxial layers Schottky detectors: Alpha spectroscopy and deep level transient spectroscopy studies
Authors: Mannan Mohammad A. , Chaudhuri Sandeep K. , Nguyen Khai V. , Mandal Krishna C.
Published: June 2014

Spectroscopic performance of Schottky barrier alpha particle detectors fabricated on 50 μm thick n-type 4H-SiC epitaxial layers containing Z1/2, EH5, and Ci1 deep levels were investigated. The device performance was evaluated on the basis of junction current/capacitance characterization and alpha pulse-height spectroscopy. Capacitance mode deep level transient spectroscopy revealed the presence of the above-mentioned deep levels along with two shallow level defects related to titanium impurities (Ti(h) and Ti(c)) and an unidentified deep electron trap located at 2.4 eV below the conduction band minimum, which is being reported for the first time. The concentration of the lifetime killer Z1/2 defects was found to be 1.7 × 1013 cm−3. The charge transport and collection efficiency results obtained from the alpha particle pulse-height spectroscopy were interpreted using a drift-diffusion charge transport model. Based on these investigations, the physics behind the correlation of the detector properties viz., energy resolution and charge collection efficiency, the junction properties like uniformity in barrier-height, leakage current, and effective doping concentration, and the presence of defects has been discussed in details. The studies also revealed that the dominating contribution to the charge collection efficiency was due to the diffusion of charge carriers generated in the neutral region of the detector. The 10 mm2 large area detectors demonstrated an impressive energy resolution of 1.8% for 5486 keV alpha particles at an optimized operating reverse bias of 130 V.
The growth mechanisms of graphene directly on sapphire substrates by using the chemical vapor deposition
Authors: Lin Meng-Yu , Su Chen-Fung , Lee Si-Chen , Lin Shih-Yen
Published: June 2014

Uniform and large-area graphene films grown directly on sapphire substrates by using a low-pressure chemical vapor deposition system are demonstrated in this paper. The evolution process and the similar Raman spectra of the samples with different growth durations have confirmed that the continuous graphene film is formed by graphene flakes with similar sizes. The layer-by-layer growth mechanism of this approach is attributed to the preferential graphene deposition on sapphire surfaces. The etching effect of H2 gas is demonstrated to be advantageous for the larger graphene grain formation. The smooth surface of substrates is also proved to be a key parameter for continuous graphene film formation with better crystalline quality.
Sub-coercive and multi-level ferroelastic remnant states with resistive readout
Authors: Kundys B. , Iurchuk V. , Meny C. , Majjad H. , Doudin B.
Published: June 2014

Ferroelectric devices use their electric polarization ferroic order as the switching and storage physical quantity for memory applications. However, additional built-in physical quantities and memory paradigms are requested for applications. We propose here to take advantage of the multiferroic properties of ferroelectrics, using ferroelasticity to create a remnant strain, persisting after stressing the material by converse piezoelectricity means. While large electric fields are needed to switch the polarization, here writing occurs at subcoercive much lower field values, which can efficiently imprint multiple remnant strain states. A proof-of-principle cell, with the simplest and non-optimized resistance strain detection design, is shown here to exhibit 13-memory states of high reproducibility and reliability. The related advantages in lower power consumption and limited device fatigue make our approach relevant for applications.
Predictions of an alternative pathway for grain-boundary driven twinning
Authors: Hunter A. , Beyerlein I. J.
Published: June 2014

The exceptional strength of nanoscale metallic grains is due to strain-accommodation mechanisms that are uncommon in their coarse-grained counterparts, such as deformation twinning. Using an ab initio density functional theory-phase field dislocation dynamics model, we provide evidence of an unconventional kinetic pathway for twin formation in nano-sized crystals involving two grain boundaries. It corresponds to greater favorability because it accommodates strain yet removes debilitating backstresses. A simple map is presented to relate the associated kinetics of nucleation and propagation to intrinsic material defect formation energies.
Neutron diffraction study on very high elastic strain of 6% in an Fe3Pt under compressive stress
Authors: Yamaguchi Takashi , Fukuda Takashi , Kakeshita Tomoyuki , Harjo Stefanus , Nakamoto Tatsushi
Published: June 2014

An Fe3Pt alloy with degree of order 0.75 exhibits a second-order-like martensitic transformation from a cubic structure to a tetragonal one at about 90 K; its tetragonality c/a changes nearly continuously from 1 to 0.945 on cooling from 90 K to 14 K. We have investigated the change in lattice parameters in a single crystal of the Fe3Pt alloy at 93 K under compressive stresses, σ, applied in the [001] direction by neutron diffraction. The tetragonality c/a has decreased continuously from 1 to 0.907 with an increase in |σ| up to |σ| = 280 MPa; the corresponding lattice strain in the [001] direction, due to the continuous structure change, increases from 0% to 6.1%. When the stress of 300 MPa is reached, c/a has changed abruptly from 0.907 to 0.789 due to a first-order martensitic transformation.
Evaluation of the efficacy of sequential or continuous administration of probiotics and phytogenics in broiler diets
Authors: Mountzouris K. C. , Tsirtsikos P. , Papadomichelakis G. , Schatzmayr G. , Fegeros K.
Published: June 2014

Three dietary combinations of probiotics and phytogenics administered sequentially or continuously were assessed for their effects on broiler performance, nutrient digestibility, caecal microbiota composition, volatile fatty acid (VFA) pattern and plasma total antioxidant capacity (TAC). One-day-old Cobb male broilers (n = 525) were allocated to five experimental treatments for 42 days. Each treatment had three replicates of 35 broilers each. Depending on the time-frame of sequential or continuous addition in the basal diet (BD) of the probiotics (108 CFU/kg BD) and phytogenics (125 mg/kg BD), experimental treatments were: control (no additions, Days 1–42); PE1, probiotic Days 1–14 and phytogenic Days 15–42; PE2, probiotic Days 1–28 and phytogenic Days 29–42; PE3, probiotic and phytogenic continuously (Days 1–42); and A (2.5 mg avilamycin/kg diet, Days 1–42). There was no loss of probiotic viability upon mixing with the phytogenic for up to 7 days. Overall bodyweight gain was higher (P = 0.025) in the control and PE1 than PE2 and PE3, whereas Treatment A was intermediate and not different from the rest. Overall feed intake in the control was the highest (P = 0.003). Treatments PE1, PE2 and PE3 had better (P = 0.004) overall feed conversion ratio (FCR) than the control. The FCR in PE1 and PE3 did not differ from A, which had the best FCR. Mortality did not differ among treatments. Nutrient digestibility and caecal microbiota composition did not differ among treatments. However, differences (P ≤ 0.05) in caecal VFA pattern were noted, with the control having the lowest acetate molar ratio as well as the highest sum of valeric, hexanoic and heptanoic acids. Plasma TAC in the control was lower than in PE3, PE1 and PE2 at Day 14 (P < 0.001) and PE1 (P = 0.003) at Day 42. The concept of sequential or throughout probiotic and phytogenic administration showed promising results regarding feed efficiency and plasma TAC.
Steric Trapping of the High Spin State in FeIII Quinolylsalicylaldimine Complexes
Authors: Sertphon Darunee , Harding David J. , Harding Phimphaka , Murray Keith S. , Moubaraki Boujemaa , Adams Harry
Published: June 2014

A new sterically bulky Schiff base ligand, N-(8-quinolyl)-5-tert-butylsalicylaldimine (Hqsal-5-tBu) has been prepared and a series of FeIII complexes, [Fe(qsal-5-tBu)2]Y (Y = Cl 1, ClO4 2, NO3 3, BF4 4) utilising this ligand are reported and fully characterised. UV-vis spectroscopic and electrochemical studies indicate that 1–4 are high spin (HS) in solution at room temperature and further suggest that the tBu group only slightly alters the electronic properties of 1–4 compared with related [Fe(qsal-5-X)2]+ systems. The structures of [Fe(qsal-5-tBu)2]Cl·4MeOH·H2O 1, [Fe(qsal-5-tBu)2]ClO4·MeOH 2, and [Fe(qsal-5-tBu)2]NO3 3 determined at 100 K reveal HS FeIII centres in all cases. Four-fold parallel aryl embraces and π–π interactions serve to link the cations forming 2D sheets mirroring the motifs found in other [Fe(qsal-5-X)2]+ complexes. Despite this the tBu group causes strong distortions at the Fe centre which as magnetic studies reveal prevent spin crossover trapping 1–4 in the HS state.
Emergency department mental health presentations by people born in refugee source countries: an epidemiological logistic regression study in a Medicare Local region in Australia
Authors: Enticott Joanne C. , Cheng I-Hao , Russell Grant , Szwarc Josef , Braitberg George , Peek Anne , Meadows Graham
Published: June 2014

This study investigated if people born in refugee source countries are disproportionately represented among those receiving a diagnosis of mental illness within emergency departments (EDs). The setting was the Cities of Greater Dandenong and Casey, the resettlement region for one-twelfth of Australia’s refugees. An epidemiological, secondary data analysis compared mental illness diagnoses received in EDs by refugee and non-refugee populations. Data was the Victorian Emergency Minimum Dataset in the 2008–09 financial year. Univariate and multivariate logistic regression created predictive models for mental illness using five variables: age, sex, refugee background, interpreter use and preferred language. Collinearity, model fit and model stability were examined. Multivariate analysis showed age and sex to be the only significant risk factors for mental illness diagnosis in EDs. ‘Refugee status’, ‘interpreter use’ and ‘preferred language’ were not associated with a mental health diagnosis following risk adjustment for the effects of age and sex. The disappearance of the univariate association after adjustment for age and sex is a salutary lesson for Medicare Locals and other health planners regarding the importance of adjusting analyses of health service data for demographic characteristics.
DNA looping-dependent autorepression of
LEE1
P1 promoters by Ler in enteropathogenic
Escherichia coli
(EPEC)
Authors: Bhat Abhayprasad , Shin Minsang , Jeong Jae-Ho , Kim Hyun-Ju , Lim Hyung-Ju , Rhee Joon Haeng , Paik Soon-Young , Takeyasu Kunio , Tobe Toru , Yen Hilo , Lee Gwangrog , Choy Hyon E.
Published: June 2014

Significance

Ler [locus of
e
nterocyte
e
ffacement (LEE)-encoded regulator], encoded by the first gene of the LEE1 operon in enteropathogenic
Escherichia coli
(EPEC), represses its own transcription driven by two promoters separated by 10 bp. We found that Ler does this repression through a DNA loop of 16 helical turns, in which RNA polymerase is trapped as open promoter complex, although this complex should be most readily transformed into productive initiation complex.
Future Robots
Authors: Parisi Domenico
Published: June 2014

This book is for both robot builders and scientists who study human behaviour and human societies. Scientists do not only collect empirical data but they also formulate theories to explain the data. Theories of human behaviour and human societies are traditionally expressed in words but, today, with the advent of the computer they can also be expressed by constructing computer-based artefacts. If the artefacts do what human beings do, the theory/blueprint that has been used to construct the artefacts explains human behaviour and human societies. Since human beings are primarily bodies, the artefacts must be robots, and human robots must progressively reproduce all we know about human beings and their societies. And, although they are purely scientific tools, they can have one very important practical application: helping human beings to better understand the many difficult problems they face today and will face in the future - and, perhaps, to find solutions for these problems.
Chapter 5. Process and product, means and ends
Authors: Kelen Christopher
Published: June 2014

In this chapter, Kit Kelen presents a personal account of his efforts to establish a Creative Writing pedagogy for non-native learners of English in the particular ESL context of post-handover (i.e. post-1999) Macao. Employing a Freirean framework, the chapter argues for the social-institutional necessity of a process and publication oriented curriculum. Pedagogical/ethical issues are canvased in the hope of presenting the reader with ideas for the future development of such curricula, as of particular relevance in what have been termed the “Confucian Heritage Culture” zones of East Asia.
Children’s pragmatic use of prosodic prominence
Authors: Ito Kiwako
Published: June 2014

Prosodic cues are known to support the development of early speech perception and basic communication skills such as turn-taking and comprehension of speaker’s intent in infants. Research on the effect of prosody on language development in older children is relatively sparse. This chapter discusses the production and comprehension of prosodic prominence for referential expressions in toddlers and older children. Reviews of past and recent studies with various experimental techniques suggest that both an inventory of intonation contours and online responses to prosodic prominence improve rather gradually throughout childhood. More systematic cross-linguistic studies are needed to reveal how language-specific prosodic structure and individual’s general cognitive ability affect the development of pragmatically relevant use of pitch prominence.
The Pragmatic Development of Humor
Authors: Hoicka Elena
Published: June 2014

Humor development is underpinned by children’s pragmatic abilities. This chapter will highlight the link between humor and pragmatics, demonstrating that understanding contexts and intentions is often key to interpreting humor. It will also discuss different theories of humor processing, including incongruity theories, behavioral theories, and pragmatic theories based on Grice’s maxims and Relevance Theory. This chapter will detail research about the development of humor appreciation and production from infancy through adolescence, including children’s understanding of the pragmatics involved in joking. Finally, research on the development of humor in children with autism and Asperger syndrome will be examined, highlighting that humor is more difficult for children with pragmatic difficulties.
Counterfactual reasoning, responsibility and blame for serial murders: the perception and prevention of violent crimes / Razonamiento contrafáctico, responsabilidad y culpa de los asesinatos en serie: la percepción y prevención de los crímenes violentos
Authors: Segura Susana
Published: June 2014

The present research evaluates people’s perception of serial murders, analysing the effects of controllability in counterfactual reasoning about the past and the future, as well as attributions of responsibility and blame. Besides, the research analyses the effects of perspective (one’s own versus other people’s) in these attributions. Participants were 442 students who answered open-ended questions designed for this study. The first experiment shows that people focus on controllable factors previous to these events. When considering the avoidance and prevention of general serial murders, they focus on representatives of formal authority. Moreover, when judging from their own perspective, blame is attributed to the perpetrator and responsibility to both parties; while from another person´s perspective, they attribute feelings of either responsibility or guilt to the representatives of formal authority and a lack of these feelings to the perpetrator. The second experiment shows identical results regarding the specific case of a well-known serial killer in England and Spain. These findings demonstrate that this perception has implications for the legal framework and the prevention of violent crimes.
Attenuation of migration properties of CD4+ T cells from aged mice correlates with decrease in chemokine receptor expression, response to retinoic acid, and RALDH expression compared to young mice
Authors: Park Jihyun , Miyakawa Takuya , Shiokawa Aya , Nakajima-Adachi Haruyo , Tanokura Masaru , Hachimura Satoshi
Published: June 2014

Aging results in attenuation of abilities to mount appropriate immune responses. The influence of aging on CD4+ T cell migration ability toward chemokines was investigated with young and aged mice. We found functional decline in migration ability toward CCL19 and also decreased CCR7 expression level in antigen-stimulated CD4+ T cells from aged mice compared with those from young mice. Upon addition of retinoic acid (RA), CD4+ T cells from aged mice showed decreased CCR9 expression level compared to young mice and the migration ability of CD4+ T cells from aged mice toward CCL25 was attenuated compared to young mice. We also observed that the expression of RALDH2 mRNA was decreased in mesenteric lymph node dendritic cells from aged mice compared to those from young mice. These results demonstrate that attenuated migration abilities of CD4+ T cells were observed in aged mice, which correlated with decreased chemokine receptor expression. Furthermore, the reduced production and response to RA by aging may be one of the causes of such attenuated migration abilities in the intestinal immune system.
Detection of mutations by fill-in ligation reaction with enzyme-linked immunosorbent assay for rapid medical diagnosis
Authors: Tang Yi-Tong , Xiao Na , Li Zhi-Shan , Zou Jiu-Ming , Cao Rui , Zhao Xue-Hong , Shao Jin-Hui
Published: June 2014

Several approaches for parallel genotyping have been developed with increasingly available information on DNA variation. However, these methods require either complex laboratory procedures or expensive instrumentation. None of these procedures is readily performed in local clinical laboratories. In this study, we developed a flexible genotyping method involving fill-in ligation reaction with enzyme-linked immunosorbent assay successfully applied to detect important single-nucleotide polymorphisms (SNPs) for EGFR c.2573T > G (L858R), EGFR c.2582T > A (L861Q), and EGFR c.2155G > T (G719C). This assay exhibited excellent specificity, with a sensitivity as low as 0.5%. Eight out of 62 clinical samples were identified as heterozygotes for the SNP site of L858R, whereas only two samples were identified as heterozygotes by direct sequencing. The developed method enabled accurate identification of SNP in a simple and cost-effective manner adapted to routine analysis.
Lipids in cell biology: how can we understand them better?
Authors: Muro Eleonora , Atilla-Gokcumen G. Ekin , Eggert Ulrike S.
Published: June 2014

Lipids are a major class of biological molecules and play many key roles in different processes. The diversity of lipids is on the same order of magnitude as that of proteins: cells express tens of thousands of different lipids and hundreds of proteins to regulate their metabolism and transport. Despite their clear importance and essential functions, lipids have not been as well studied as proteins. We discuss here some of the reasons why it has been challenging to study lipids and outline technological developments that are allowing us to begin lifting lipids out of their “Cinderella” status. We focus on recent advances in lipid identification, visualization, and investigation of their biophysics and perturbations and suggest that the field has sufficiently advanced to encourage broader investigation into these intriguing molecules.