bluuebunny/crossref_metadata_2025 huggingface dataset:
Crosstalk‐aware cross‐core virtual concatenation in spatial division multiplexing elastic optical networks
Authors: Zhao Yongli , Zhang Jie
Published: September 2016

Spatial division multiplexing elastic optical networks (SDM‐EONs) will become the most important form of future optical transport networks, because it can break the physical limit of achievable capacity in single‐mode and single‐core fibre. However, spectrum fragmentation issue becomes more serious in SDM‐EONs compared with in single EON. Crosstalk‐aware cross‐core virtual concatenation (CCVC) scheme is first proposed to solve the spectrum fragmentation issue in SDM‐EONs. Simulation results show that CCVC can achieve lower blocking probability and higher spectrum utilisation compared with single‐core virtual concatenation scheme.
Attribute selection using binary flower pollination algorithm with greedy crossover and ‘one to all’ initialisation
Authors: Preethi C.M. , Vanathi P.T.
Published: September 2016

Wrapper‐based methodology for attribute selection is achieved by employing ‘support vector machine (SVM)’ and ‘binary flower pollination algorithm (BFPA)’. A greedy crossover is proposed to reset the suboptimal solution obtained on pre‐mature convergence. Also, ‘one to all’ initialisation is developed to devise the initial pollen population for diversified exploration. The proposed methodologies are validated with datasets from uc irvine (UCI) repository and results show superior performance on comparison with the literature on both ‘BFPA’ and other metaheuristic algorithms for attribute selection.
Unified PWM algorithm based on effective time for four‐switch three‐phase inverter
Authors: Sun Dan , Zhou Wenzhi , Zheng Zhihao
Published: September 2016

A unified pulse‐width modulation (PWM) algorithm is proposed for four‐switch three‐phase inverter (FSTPI) to reveal the essential relationship among different PWM algorithms. The FSTPI generates only four active vectors and the zero vector is absent, so the zero vector can be synthesised by two opposite active vectors or all four vectors. Effective time for different phase is derived for the proposed unified PWM. By altering the distribution of effective time in a PWM period, various PWM algorithms with different equivalent zero vectors are implemented. In the proposed algorithm, sector identification and trigonometric function calculation are not required and the voltage fluctuation across the two dc‐link capacitors is also taken into account. Thus, the desired output voltage can be synthesised simply and precisely. Experimental results confirm the effectiveness of the proposed unified PWM algorithm.
Non‐volatile magnetic decoder based on MTJs
Authors: Deng E.Y. , Prenat G. , Anghel L. , Zhao W.S.
Published: September 2016

Spin transfer torque based magnetic tunnel junction (STT‐MTJ) is under intense investigation for the design of hybrid spintronics/CMOS circuits. A novel non‐volatile magnetic decoder (MD) based on MTJs is presented. Its output data is stored into a pair of MTJs in non‐volatile state. The proposed MD promises area efficiency by sharing the same sense amplifier for normal CMOS‐based dynamic decoder mode and non‐volatile data sensing mode. Moreover, the symmetric structure largely weakens the impact of sneak current and ensures reliable sensing. By using a compact STT‐MTJ model and the STMicroelectronics CMOS 28 nm design kit for CMOS counterparts, transient and Monte Carlo simulations are performed to validate its functionality and evaluate its performance merits.
High performance adjacent error detection for nanometer devices
Authors: Erozan A. T. , Tavli B.
Published: September 2016

Static random‐access memory (SRAM) based memories are widely used in electronic systems and if their contents change due to external reasons, the electronic system can functionally fail. One of the external reasons is the radiation induced soft errors as the SRAM memories are susceptible to radiation effects. Majority of the recently proposed methods use error correction codes (ECC) to mitigate soft errors. Error correction/detection capabilities of such methods are at most 3 bits in a codeword which will be insufficient while number of memory bits affected by a radiation particle is increased, as CMOS process technology shrinks towards around 5 nm. Since memory bits affected by a radiation particle are physically close, adjacent error detection/correction becomes a hot research topic. In this Letter, Euclidean geometry‐low density parity check code, more capable ECC than Hamming code used in recent works, is explored in context of adjacent error detection performance. The results show that proposed method successfully detects up to 14‐bit adjacent errors in a 15‐bit codeword. As such, this method is suitable where high detection performance is needed. The proposed method is also simplified for efficient hardware implementation while detection performance is not sacrificed. Both methods are compared in terms of resource usage.
Fixed‐time stabilisation and consensus of non‐holonomic systems
Authors: Defoort Michael , Demesure Guillaume , Zuo Zongyu , Polyakov Andrey , Djemai Mohamed
Published: September 2016

This study deals with the fixed‐time stabilisation of a class of non‐linear systems. A non‐linear controller, based on sliding mode, is proposed to ensure the fixed‐time stabilisation of a non‐holonomic system in chained form. An upper bound of the settling time, independent of the initial system state, is estimated. Then, a distributed switched strategy, based on local information, is introduced to solve the fixed‐time consensus problem for multiple non‐holonomic agents. Using Lyapunov functions, the switching times are explicitly given and only depend on the controller gains and the Laplacian matrix. Simulation results highlight the efficiency of the proposed method.
Stability and steady‐state analysis of distributed cooperative droop controlled DC microgrids
Authors: Xiang Ji , Wang Yu , Li Yanjun , Wei Wei
Published: September 2016

Distributed cooperative droop control consisting of the primary decentralised droop control and the secondary distributed control is studied, which aims to achieve an exact current sharing between generators, worked in the voltage control mode, of DC microgrids. For the DC microgrids with the distributed cooperative droop control, the dynamic stability has not been well investigated although its steady performance has been widely reported. This study focuses on the stability problem of DC microgrids with fixed topology and shows it is equivalent to the semistability problem of a class of second‐order matrix systems. Some further sufficient conditions as well followed. The steady state is analysed deeply for some special cases. A DC microgrid of four nodes is simulated on the Matlab/Simulink platform to illustrate the efficacy of analytic results.
Distributed consensus of non‐linear fractional‐order multi‐agent systems with directed topologies
Authors: Gong Ping
Published: September 2016

In this study, Mittag–Leffler stability and the fractional Lyapunov direct method are used to study fractional‐order leaderless and leader‐following consensus algorithms with non‐linear dynamics under a directed network topology. The sufficient conditions are given to guarantee that the consensus can be achieved in the non‐linear fractional‐order systems with and without a virtual leader, and the adaptive feedback control protocols are also given in this study. Finally, some numerical simulations are presented to demonstrate the effectiveness of the theoretical results.
Real‐time multi‐feature based fire flame detection in video
Authors: Chi Rui , Lu Zhe‐Ming , Ji Qing‐Ge
Published: September 2016

In this study, the authors present a new approach to detect fire flame by processing and analysing the stationary camera videos. For a fire detection system, it is desired to be sensitive and reliable. The proposed method improves not only the sensitivity but also the reliability through reducing the susceptibility to false alarms. The proposed approach based on multi‐feature, i.e. chromatic features, dynamic features, texture features, and contour features, can both improve the sensitivity and reliability in fire detection. In their approach, the authors adopt a novel algorithm to extract the moving region and analyse the frequency of flickers. Experimental results show that the proposed method can run in real‐time and performs favourably against the state‐of‐the‐art methods with higher accuracy in fire videos, lower false alarm rates in non‐fire videos and faster response time.
Strategic car‐following gap model considering the effect of cut‐ins from adjacent lanes
Authors: Dou Yangliu , Ni Daiheng , Wang Zhao , Wang Jianqiang , Yan Fengjun
Published: September 2016

Drivers are typically faced with two competing challenges when following a preceding vehicle: they need to leave sufficient space in front to ensure safety, while doing so the probability of cut‐ins by other vehicles increases as the car‐following gap (CFG) becomes large. Therefore, a strategic CFG that addresses both challenges becomes critical. This study proposes a method to address the problem through an overall objective function of CFG and velocity considering the safety hazard and the probability of cut‐ins by other vehicles. Based on this, seeking the strategic CFG translates to finding the optimal solution that minimises the overall objective function. With the support of field data, the method along with concrete models are instantiated and application of the method is elaborated. The method presented in this study can be used to enhance traffic safety and improve traffic management in a connected vehicle environment that promises cooperative adaptive cruise control and cooperative crash avoidance systems.
Light‐addressable potentiometric sensor with the micro blind holes substrate
Authors: Chen Dong , Liu Shi‐bin , Yin Shi‐min , Liang Jin‐tao
Published: September 2016

The light‐addressable potentiometric sensor (LAPS) is one sort of biochemical sensor based on semiconductor principle. To improve the performance of LAPS, a novel designed silicon substrate with micro blind holes structure used for LAPS is presented in this study. In this structure, a great number of micro blind holes are constructed on the back surface of substrate by silicon wet etching technology. When light illuminating the bottom of substrate, because of the light trapping effect, multiple reflection on surface of substrate increases the absorption of light, which will remarkably enhance the photoelectric conversion efficiency. In this research, LAPS chips with 300 μm thick substrate, 270 μm thick substrate, 200 μm thick substrate, and micro blind holes substrate were constructed. The performance of these LAPS, such as amplitude of photocurrent, sensitivity, linearity, signal to noise ratio (SNR) were evaluated, and the results showed that, constructing micro blind holes structure on back surface of substrate illuminated by light can remarkably increase the amplitude of photocurrent, sensitivity, linearity and SNR, and additionally maintain the mechanical strength of substrate, which means the structure is an effective way to improve performance of LAPS.
Analysis of the direct current ionised field near the field mill probe with a hat‐shaped electrode
Authors: Zou Zhilong , Xu Jiayu , Cui Xiang , Lu Tiebing
Published: September 2016

Ionised field strength on the ground level is one of fundamental electromagnetic environment parameters of high voltage direct current transmission lines. Field mill is generally employed to measure the ground‐level ionised field. In order to reduce the field distortion caused by the field mill probe on the ground, a measurement method of the ionised field with a hat‐shaped additional electrode is presented in this study. Ionised field distribution on the probe with the hat‐shaped electrode is analysed through both calculations and measurements. The ionised field is computed by the upstream finite element method (FEM) and is measured between a corona wire net and a parallel grounded plate. Experimental results demonstrate that the relative error between measurements and calculations is approximately 3%. The field distortion can be ameliorated effectively by the proposed method.
Buchrezension „Fokus Führung“: Fundgrube mit Hindernissen
Authors: König Romy
Published: September 2016

Im Buch „Fokus Führung“ von Josef Düllings, Hans-Fred Weiser und Andreas Westerfellhaus finden sich reichlich Schätze. Doch der Weg dorthin ist zuweilen steinig, findet unsere Autorin Romy König.
Pflegeberufegesetz: Opfer politischer Prokrastination
Authors: Hug Josef
Published: September 2016

Es gibt wohl kaum ein Gesetz, das in Bundesrat und Bundestag so lange hin- und hergeschoben wurde wie das Pflegeberufegesetz. Mit den ersten Absolventen der generalistischen Ausbildung ist nun erst ab 2022 zu rechnen. Das ist viel zu spät, meint der Pflegedirektor des Klinikums Karlsruhe.
Medizintechnik: Das Geschäft mit den Daten beginnt
Authors: König Romy
Published: September 2016

Siemens hat einen neuen IT-Service für die Bildgebung entwickelt: In einer Cloud können Radiologen Untersuchungsdaten sammeln, auswerten und mit Referenzwerten abgleichen. Es ist der Einstieg in ein Geschäftsfeld mit großem Wachstumspotenzial.
Systempartnerschaften: „Umfassende Prozessverantwortung“
Authors: Mewis Dirk
Published: September 2016

Stefan Schaller, Leiter von Siemens Healthineers Deutschland über die Senkung der Kosten im klinischen Ablauf, Produktqualität und die unterschiedliche Ausgestaltung von Systempartnerschaften.
BuFaTa 2016: Optimierungspotenziale ausschöpfen und die jungen Alten bedienen
Authors: Thalmayr Maria
Published: September 2016

Ob ein Patient wertschöpfend behandelt werden kann, entscheidet sich vielfach im teuersten Funktionsbereich des Krankenhauses: im OP. Viele Krankenhäuser nehmen deshalb augenblicklich sehr viel Geld in die Hand, um ihre Operationssäle auf den neuesten Stand zu bringen.
Responsivity calibration of the LoWEUS spectrometer
Authors: Lepson J. K. , Beiersdorfer P. , Kaita R. , Majeski R. , Boyle D.
Published: September 2016

We performed an in situ calibration of the relative responsivity function of the Long-Wavelength Extreme Ultraviolet Spectrometer (LoWEUS), while operating on the Lithium Tokamak Experiment (LTX) at Princeton Plasma Physics Laboratory. The calibration was accomplished by measuring oxygen lines, which are typically present in LTX plasmas. The measured spectral line intensities of each oxygen charge state were then compared to the calculated emission strengths given in the CHIANTI atomic database. Normalizing the strongest line in each charge state to the CHIANTI predictions, we obtained the differences between the measured and predicted values for the relative strengths of the other lines of a given charge state. We find that a 3rd degree polynomial function provides a good fit to the data points. Our measurements show that the responsivity between about 120 and 300 Å varies by factor of ∼30.
Investigation of the viscous reconnection phenomenon of two vortex tubes through spectral simulations
Authors: Beardsell Guillaume , Dufresne Louis , Dumas Guy
Published: September 2016

This paper aims to shed further light on the viscous reconnection phenomenon. To this end, we propose a robust and efficient method in order to quantify the degree of reconnection of two vortex tubes. This method is used to compare the evolutions of two simple initial vortex configurations: orthogonal and antiparallel. For the antiparallel configuration, the proposed method is compared with alternative estimators and it is found to improve accuracy since it can account properly for the formation of looping structures inside the domain. This observation being new, the physical mechanism for the formation of those looping structures is discussed. For the orthogonal configuration, we report results from simulations that were performed at a much higher vortex Reynolds number (ReΓ ≡ circulation/viscosity = 104) and finer resolution (N3 = 10243) than previously presented in the literature. The incompressible Navier-stokes equations are solved directly (Direct Numerical Simulation or DNS) using a Fourier pseudospectral algorithm with triply periodic boundary conditions. The associated zero-circulation constraint is circumvented by solving the governing equations in a proper rotating frame of reference. Using ideas similar to those behind our method to compute the degree of reconnection, we split the vorticity field into its reconnected and non-reconnected parts, which allows to create insightful visualizations of the evolving vortex topology. It also allows to detect regions in the vorticity field that are neither reconnected nor non-reconnected and thus must be associated to internal looping structures. Finally, the Reynolds number dependence of the reconnection time scale Trec is investigated in the range 500 ≤ ReΓ ≤ 10 000. For both initial configurations, the scaling is generally found to vary continuously as ReΓ is increased from Trec∼ReΓ−1 to Trec∼ReΓ−1/2, thus providing quantitative support for previous claims that the reconnection physics of two vortices should be similar regardless of their spatial arrangement.
Validations of calibration-free measurements of electron temperature using double-pass Thomson scattering diagnostics from theoretical and experimental aspects
Authors: Tojo H. , Yamada I. , Yasuhara R. , Ejiri A. , Hiratsuka J. , Togashi H. , Yatsuka E. , Hatae T. , Funaba H. , Hayashi H. , Takase Y. , Itami K.
Published: September 2016

This paper evaluates the accuracy of electron temperature measurements and relative transmissivities of double-pass Thomson scattering diagnostics. The electron temperature (Te) is obtained from the ratio of signals from a double-pass scattering system, then relative transmissivities are calculated from the measured Te and intensity of the signals. How accurate the values are depends on the electron temperature (Te) and scattering angle (θ), and therefore the accuracy of the values was evaluated experimentally using the Large Helical Device (LHD) and the Tokyo spherical tokamak-2 (TST-2). Analyzing the data from the TST-2 indicates that a high Te and a large scattering angle (θ) yield accurate values. Indeed, the errors for scattering angle θ = 135° are approximately half of those for θ = 115°. The method of determining the Te in a wide Te range spanning over two orders of magnitude (0.01–1.5 keV) was validated using the experimental results of the LHD and TST-2. A simple method to provide relative transmissivities, which include inputs from collection optics, vacuum window, optical fibers, and polychromators, is also presented. The relative errors were less than approximately 10%. Numerical simulations also indicate that the Te measurements are valid under harsh radiation conditions. This method to obtain Te can be considered for the design of Thomson scattering systems where there is high-performance plasma that generates harsh radiation environments.
Shock interaction mechanisms on a double wedge at Mach 7
Authors: Durna Ahmet Selim , El Hajj Ali Barada Mohamad , Celik Bayram
Published: September 2016

Present computational study investigates formation and interaction mechanisms of shocks and boundary layer for low enthalpy Mach 7 flows of nitrogen over double wedges, which have fixed fore and various aft angles of 30° and 45°–60°, respectively. We use a density based finite-volume Navier-Stokes solver to simulate low enthalpy Mach 7 flows of nitrogen over double wedges. The solver is first and second order accurate in time and space, respectively. The meshes used in simulations of two-dimensional laminar flows consist of multiple blocks of structured mesh. Depending on the intensity, impingement angle, and impingement location of transmitted shock wave, the resulting adverse pressure gradient related disturbances on the wedge surface can trigger complex flow physics both in subsonic and supersonic regions. We observe a strong interaction between the deformation of the boundary layer and the bow shock as well as the transmitted shock for high aft angles. Comparison of the obtained results in terms of general flow physics shows that there exists an aft angle threshold value for such interaction which is in the range of 45°–50°.
Sub-THz thermally activated-electrical conductivity of CdS thin films
Authors: Rahman Rezwanur , Scales John A.
Published: September 2016

The electrical conductivity of a CdS thin film controlled by grain structures is essential to enhance its photoconductivity to be able to be fit as a window material in CdS/CdTe heterojunction solar cells. In order to characterize a thin film, electromagnetically, we employed an open cavity resonator with a sub-millimeter Vector Network Analyzer. Our technique is capable of measuring complex dielectric permittivity, ϵ̃, of a photovoltaic film as thin as 0.1 μm. We measured the real part of the complex dielectric permittivity, ϵre, and electrical conductivity, σre (derived from the imaginary part, ϵim), of unannealed and annealed CdS films with thicknesses ∼0.15 μm on ∼3 mm thick-borosilicate glass substrates, at room temperature. We obtain the (thermally activated) electrical conductivity between 100 and 312 GHz, which is less in annealed samples than in unannealed ones by ∼2 orders of magnitude. Contrary to our expectations, the carrier concentrations extracted from these data by fitting a Drude model are ∼1016 cm−3 (unannealed) and ∼1014 cm−3 (annealed). We investigate the connection between the grain size and carrier concentration.
Magnetocaloric effect and the influence of pressure on magnetic properties of La-excess pseudo-binary alloys La1+δ(Fe0.85Si0.15)13
Authors: Vuong Van Hiep , Do Thi Kim Anh , Thuan Nguyen Khac , Le Van Hong , Nhat Hoang Nam
Published: September 2016

The La-excess alloys La1+δ(Fe0.85Si0.15)13 (δ = 0.06 and 0.09) exhibit large magnetocaloric effect which has been attributed to the occurrence of itinerant-electron metamagnetic transition near the Curie temperature TC. The maximum entropy change −ΔSm was shown to be from 4.5 to 11.5 J/kg K for the applied field variation ΔH from 20 to 70 kOe, respectively. The estimated relative cooling power for ΔH = 70 kOe was 418 J/kg. The alloys show a typical NaZn13-type cubic structure, featuring a doping-induced magnetovolume effect with the increase in TC. Under the applied pressure up to 2 GPa, the TC as deduced from resistance measurements decreased linearly, ΔTC = 113 (for δ = 0.06) and 111 K (for δ = 0.09), together with a corresponding decrease of resistivity, Δρ = 6.1 μΩ m at room temperature for both samples. At a low pressure, the effect of spontaneous magnetostriction on TC caused by applying the pressure appeared to have a similar magnitude to that of the negative magnetovolume effect caused by La-excess doping. In comparison with other stoichiometric La(Fe1−xSix)13 compounds, the pressure in our case was shown to have a smaller influence on TC.
Coupled wave equations theory of surface-enhanced femtosecond stimulated Raman scattering
Authors: McAnally Michael O. , McMahon Jeffrey M. , Van Duyne Richard P. , Schatz George C.
Published: September 2016

We present a coupled wave semiclassical theory to describe plasmonic enhancement effects in surface-enhanced femtosecond stimulated Raman scattering (SE-FSRS). A key result is that the plasmon enhanced fields which drive the vibrational equation of motion for each normal mode results in dispersive lineshapes in the SE-FSRS spectrum. This result, which reproduces experimental lineshapes, demonstrates that plasmon-enhanced stimulated Raman methods provide unique sensitivity to a plasmonic response. Our derived SE-FSRS theory shows a plasmonic enhancement of |gpu|2ImχR(ω)gst2/ImχR(ω), where |gpu|2 is the absolute square of the plasmonic enhancement from the Raman pump, χR(ω) is the Raman susceptibility, and gst is the plasmonic enhancement of the Stokes field in SE-FSRS. We conclude with a discussion on potential future experimental and theoretical directions for the field of plasmonically enhanced coherent Raman scattering.
An automated nudged elastic band method
Authors: Kolsbjerg Esben L. , Groves Michael N. , Hammer Bjørk
Published: September 2016

A robust, efficient, dynamic, and automated nudged elastic band (AutoNEB) algorithm to effectively locate transition states is presented. The strength of the algorithm is its ability to use fewer resources than the nudged elastic band (NEB) method by focusing first on converging a rough path before improving upon the resolution around the transition state. To demonstrate its efficiency, it has been benchmarked using a simple diffusion problem and a dehydrogenation reaction. In both cases, the total number of force evaluations used by the AutoNEB method is significantly less than the NEB method. Furthermore, it is shown that for a fast and robust relaxation to the transition state, a climbing image elastic band method where the full spring force, rather than only the component parallel to the local tangent to the path, is preferred especially for pathways through energy landscapes with multiple local minima. The resulting corner cutting does not affect the accuracy of the transition state as long as this is located with the climbing image method. Finally, a number of pitfalls often encountered while locating the true transition state of a reaction are discussed in terms of systematically exploring the multidimensional energy landscape of a given process.
Effects of resistivity on linear plasma responses to resonant magnetic perturbations in tokamak plasmas
Authors: Kim Juhyung , Kim S. S. , Jhang Hogun
Published: September 2016

Numerical studies are made of the effects of resistivity on linear plasma responses to resonant magnetic perturbations (RMPs) in tokamaks based on a reduced magnetohydrodynamic model. From a local two-field model, it is suggested that the ratio of the poloidal electron advection to the resistivity diffusion rate αm can be a figure of merit parameter in linear RMP penetration physics. The shielding efficiency is governed by αm, and when αm≳1, RMPs are effectively shielded. Global simulations using a four-field model [Hazeltine and Meiss, Phys. Rep. 121, 1 (1985)] show that there exists an effective threshold of the perpendicular electron flow (Ve,⊥c) beyond which RMPs cannot penetrate. Resistivity is found to determine Ve,⊥c which increases as resistivity becomes higher, making RMP penetration easier. At low resistivity, small Ve,⊥c renders the RMP penetration sensitive to ion collisionality and the change in q95. The kink response is observed to be closely related to the residual level of RMPs at rational surfaces and can be also strongly affected by resistivity.
Evaluation of critical distances for energy transfer between Pr3+ and Ce3+ in yttrium aluminium garnet
Authors: Zeng Peng , Wei Xiantao , Zhou Shaoshuai , Yin Min , Chen Yonghu
Published: September 2016

A series of Pr3+/Ce3+ doped yttrium aluminium garnet (Y3Al5O12 or simply YAG) phosphors were synthesized to investigate the energy transfer between Pr3+ and Ce3+ for their potential application in a white light-emitting diode and quantum information storage and processing. The excitation and emission spectra of YAG:Pr3+/Ce3+ were measured and analyzed, and it revealed that the reabsorption between Pr3+ and Ce3+ was so weak that it can be ignored, and the energy transfer from Pr3+ (5d) to Ce3+ (5d) and Ce3+ (5d) to Pr3+ (1D2) did occur. By analyzing the excitation and the emission spectra, the energy transfer from Pr3+ (5d) to Ce3+ (5d) and Ce3+ (5d) to Pr3+ (1D2) was examined in detail with an original strategy deduced from fluorescence dynamics and the Dexter energy transfer theory, and the critical distances of energy transfer were derived to be 7.9 Å and 4.0 Å for Pr3+ (5d) to Ce3+ (5d) and Ce3+ (5d) to Pr3+ (1D2), respectively. The energy transfer rates of the two processes of various concentrations were discussed and evaluated. Furthermore, for the purpose of sensing a single Pr3+ state with a Ce3+ ion, the optimal distance of Ce3+ from Pr3+ was evaluated as 5.60 Å, where the probability of success reaches its maximum value of 78.66%, and meanwhile the probabilities were evaluated for a series of Y3+ sites in a YAG lattice. These results will be of valuable reference for achievement of the optimal energy transfer efficiency in Pr3+/Ce3+ doped YAG and other similar systems.
Development of a new tracer-encapsulated solid pellet injection system for more precise control of tracer-impurity-deposit location in LHD
Authors: Tamura N. , Shoji M. , Suzuki C. , Funaba H. , Hayashi H. , Maeno H. , Yokota M. , Ogawa H. , Sudo S.
Published: September 2016

A new tracer-encapsulated solid pellet (TESPEL) injection system has been developed additionally for the LHD heliotron. This system has three-dimensionally bended guide tubes, which allows us to inject the TESPEL obliquely on a poloidal cross-section of the LHD plasma. Consequently, this system enables us to control a tracer-impurity-deposited location more precisely. Moreover, this system can make it possible for the tracer impurity to be deposited even only inside the ergodic region (outside a last closed flux surface of the LHD plasma). A stereoscopic fast camera system has been also developed for capturing a three-dimensional TESPEL trajectory.
Bonding and charge transfer plasmons of conductively bridged nanoparticles: The effects of junction conductance and nanoparticle morphology
Authors: Koya Alemayehu Nana , Lin Jingquan
Published: September 2016

A detailed study of charge transfer plasmon properties of conductively bridged nanoparticles is essential for designing artificial molecules and developing plasmonic sensors. In this report, we demonstrate spectral tuning and control of local field responses of conductively bridged and compositionally homogeneous plasmonic nanoparticles of various shapes and sizes. The scattering spectral peaks of connected nanoparticles are tuned by controlling inter-particle feed-gap, junction conductance, and nanoparticle morphology. The far-field spectral responses are further tuned by increasing the number of nanoparticles from dimer to trimer, and a generalized expression for charge transfer plasmon peak shift with junction geometry is developed for various shapes of nanotrimers. The corresponding near-field distributions of the linked nanoparticles also exhibit remarkable features. Specifically, the local field profiles of dimer nanoparticles calculated at the charge transfer wavelengths show strong interaction between the nanoparticles. On the other hand, in the bridged symmetrical nanotrimers, the central nanoparticles act as a bridge and only the rest two of the nanoparticles show bright modes. These findings suggest that using conductively bridged nanoaggregates could play a significant role in tuning far-field spectral responses of plasmonic nanostructures for practical applications in molecular sensing.
Adjoint method for estimating Jiles-Atherton hysteresis model parameters
Authors: Zaman Mohammad Asif , Hansen Paul C. , Neustock Lars T. , Padhy Punnag , Hesselink Lambertus
Published: September 2016

A computationally efficient method for identifying the parameters of the Jiles-Atherton hysteresis model is presented. Adjoint analysis is used in conjecture with an accelerated gradient descent optimization algorithm. The proposed method is used to estimate the Jiles-Atherton model parameters of two different materials. The obtained results are found to be in good agreement with the reported values. By comparing with existing methods of model parameter estimation, the proposed method is found to be computationally efficient and fast converging.
Optimized coplanar waveguide resonators for a superconductor–atom interface
Authors: Beck M. A. , Isaacs J. A. , Booth D. , Pritchard J. D. , Saffman M. , McDermott R.
Published: September 2016

We describe the design and characterization of superconducting coplanar waveguide cavities tailored to facilitate strong coupling between superconducting quantum circuits and single trapped Rydberg atoms. For initial superconductor–atom experiments at 4.2 K, we show that resonator quality factors above 104 can be readily achieved. Furthermore, we demonstrate that the incorporation of thick-film copper electrodes at a voltage antinode of the resonator provides a route to enhance the zero-point electric fields of the resonator in a trapping region that is 40 μm above the chip surface, thereby minimizing chip heating from scattered trap light. The combination of high resonator quality factor and strong electric dipole coupling between the resonator and the atom should make it possible to achieve the strong coupling limit of cavity quantum electrodynamics with this system.
Stably propagating trains of attosecond electron bunches generated along the target back
Authors: Pan K. Q. , Zheng C. Y. , Cao L. H. , Liu Z. J. , He X. T.
Published: September 2016

With the help of particle-in-cell simulations, we show a stably propagating train of attosecond (10−18 s) electron bunches which are generated along the target back surface via laser-solid interactions. The electron bunches are generated by the oscillating electric fields of the surface plasma wave. Because of the combinational effects of the electrostatic field and the static magnetic field on the target back surface, the electron bunches are stably propagating along the target back surface, which means they are totally separated from the laser pulse. The averaged energy of these electron bunches is over 20 MeV, the maximum averaged density is about 6nc (where nc≈1.1×1021 cm−3 is the critical density of the incident laser), and the averaged duration is less than 200 as. Such electron bunches are easily applied to the generation of attosecond x-rays via Compton backscattering. The energy conversion efficiency from the laser to the attosecond electron bunches is about 1.5%.
Comparative study of GeO2/Ge and SiO2/Si structures on anomalous charging of oxide films upon water adsorption revealed by ambient-pressure X-ray photoelectron spectroscopy
Authors: Mori Daichi , Oka Hiroshi , Hosoi Takuji , Kawai Kentaro , Morita Mizuho , Crumlin Ethan J. , Liu Zhi , Watanabe Heiji , Arima Kenta
Published: September 2016

The energy difference between the oxide and bulk peaks in X-ray photoelectron spectroscopy (XPS) spectra was investigated for both GeO2/Ge and SiO2/Si structures with thickness-controlled water films. This was achieved by obtaining XPS spectra at various values of relative humidity (RH) of up to ∼15%. The increase in the energy shift is more significant for thermal GeO2 on Ge than for thermal SiO2 on Si above ∼10−4% RH, which is due to the larger amount of water molecules that infiltrate into the GeO2 film to form hydroxyls. Analyzing the origins of this energy shift, we propose that the positive charging of a partially hydroxylated GeO2 film, which is unrelated to X-ray irradiation, causes the larger energy shift for GeO2/Ge than for SiO2/Si. A possible microscopic mechanism of this intrinsic positive charging is the emission of electrons from adsorbed water species in the suboxide layer of the GeO2 film to the Ge bulk, leaving immobile cations or positively charged states in the oxide. This may be related to the reported negative shift of flat band voltages in metal-oxide-semiconductor diodes with an air-exposed GeO2 layer.
Environmentally induced chemical and morphological heterogeneity of zinc oxide thin films
Authors: Jiang Hua , Chou Kang Wei , Petrash Stanislas , Williams Garth , Thieme Juergen , Nykypanchuk Dmytro , Li Li , Muto Atsushi , Chen-Wiegart Yu-chen Karen
Published: September 2016

Zinc oxide (ZnO) thin films have been reported to suffer from degradation in electrical properties, when exposed to elevated heat and humidity, often leading to failures of electronic devices containing ZnO films. This degradation appears to be linked to water and oxygen penetration into the ZnO film. However, a direct observation in the ZnO film morphological evolution detailing structural and chemical changes has been lacking. Here, we systematically investigated the chemical and morphological heterogeneities of ZnO thin films caused by elevated heat and humidity, simulating an environmental aging. X-ray fluorescence microscopy, X-ray absorption spectroscopy, grazing incidence small angle and wide angle X-ray scattering, scanning electron microscopy (SEM), ultra-high-resolution SEM, and optical microscopy were carried out to examine ZnO and Al-doped ZnO thin films on two different substrates—silicon wafers and flexible polyethylene terephthalate (PET) films. In the un-doped ZnO thin film, the simulated environmental aging is resulting in pin-holes. In the Al-doped ZnO thin films, significant morphological changes occurred after the treatment, with an appearance of platelet-shaped structures that are 100–200 nm wide by 1 μm long. Synchrotron x-ray characterization further confirmed the heterogeneity in the aged Al-doped ZnO, showing the formation of anisotropic structures and disordering. X-ray diffraction and X-ray absorption spectroscopy indicated the formation of a zinc hydroxide in the aged Al-doped films. Utilizing advanced characterization methods, our studies provided information with an unprecedented level of details and revealed the chemical and morphologically heterogeneous nature of the degradation in ZnO thin films.
Silk patterns made by direct femtosecond laser writing
Authors: Maximova Ksenia , Wang Xuewen , Balčytis Armandas , Fan Linpeng , Li Jingliang , Juodkazis Saulius
Published: September 2016

Silk patterns in a film of amorphous water-soluble fibroin are created by tailored exposure to femtosecond-laser pulses (1030 nm/230 fs) without the use of photo-initiators. This shows that amorphous silk can be used as a negative tone photo-resist. It is also shown that water insoluble crystalline silk films can be precisely ablated from a glass substrate achieving the patterns of crystalline silk gratings on a glass substrate. Bio-compatible/degradable silk can be laser structured to achieve conformational transformations as demonstrated by infrared spectroscopy.
Facilitating functional complexity
Authors: Young Amy I.
Published: September 2016

This article reports on a dissertation study that explored the efficacy of language-focused differentiated instruction targeted to facilitate student oral proficiency development. The study took place in a linguistically diverse Grade 3 immersion classroom. Students’ (n = 24) oral proficiency was assessed and focal student language was evaluated at different stages of the study with attention to complexity measures. The teacher and researcher collaboratively designed instructional language supports to promote more complex language production during math and reading classes. Overall, students expanded their language complexity although Spanish home language (SHL) students appeared to benefit less than English home language students. A functional approach to language development was key to the study as students took more risks to meet their communicative needs, thereby expanding their linguistic repertoires. The teacher provided increasingly more complex alternatives for students to integrate into their classroom interactions, particularly for SHL students.
Laboratory Study of the Impact of Repetitive Electrical and Mechanical Stimulation on Brown Shrimp Crangon crangon
Authors: Soetaert Maarten , Verschueren Bart , Chiers Koen , Duchateau Luc , Polet Hans , Decostere Annemie
Published: September 2016

Pulse trawling is currently the best available alternative to beam trawling in the brown shrimp Crangon crangon and Sole Solea solea (also known as Solea vulgaris) fisheries. To evaluate the effect of repetitive exposure to electrical fields, brown shrimp were exposed to the commercial electrodes and pulse settings used to catch brown shrimp (shrimp startle pulse) or Sole (Sole cramp pulse) 20 times in 4 d and monitored for up to 14 d after the first exposure. Survival, egg loss, molting, and the degree of intranuclear bacilliform virus (IBV) infection were evaluated and compared with those in stressed but not electrically exposed (procedural control) and nonstressed, nonexposed (control) brown shrimp as well as brown shrimp exposed to mechanical stimuli. The lowest survival at 14 d (57.3%) occurred in the Sole cramp pulse treatment, and this was significantly lower than in the group with the highest survival, the procedural control (70.3%). No effect of electrical stimulation on the severity of IBV infection was found. The lowest percentage of molts occurred in the repetitive mechanical stimulation treatment (14.0%), and this was significantly lower than in the group with the highest percentage of molts, the procedural control (21.7%). Additionally, the mechanically stimulated brown shrimp that died during the experiment had a significantly larger size than the surviving individuals. Finally, no effect of the shrimp startle pulse was found. Therefore, it can be concluded that repetitive exposure to a cramp stimulus and mechanical stimulation may have negative effects on the growth and/or survival of brown shrimp. However, there is no evidence that electrical stimulation during electrotrawls would have a larger negative impact on brown shrimp stocks than mechanical stimulation during conventional beam trawling.

Received November 15, 2015; accepted May 16, 2016
Incidental bycatch of northern fulmars in the small-vessel demersal longline fishery for Greenland halibut in coastal Norway 2012–2014
Authors: Fangel Kirstin , Bærum Kim Magnus , Christensen-Dalsgaard Signe , Aas Øystein , Anker-Nilssen and Tycho
Published: September 2016

With seabird populations in rapid decline, understanding and reducing anthropogenic mortality factors is essential. One such factor is incidental bycatch in fisheries. Here we analyze bycatch in the small-vessel demersal longline fishery for Greenland halibut outside the coast of Northern Norway in 2012–2014, by means of self-reporting from fishers and independent observers. A sample of killed birds were analysed for sex, age, reproductive status and condition. Nearly all were northern fulmars. Estimated total bycatch for this fishery for the 3-year period was about 312 birds (SE ≈ 133) using a stratified estimator. Bycatch rate per 1000 hooks was estimated to approximately 0.031 (SE ≈ 0.012). Exploring per trip bycatch rates utilizing generalized linear mixed models, we found no convincing trends of environmental, spatial and temporal variables in explaining bycatch. However, trips using longlines with non-swivel hooks had a more than 100-fold larger bycatch rate (mean ≈ 0.760, SE ≈ 0.160) than those using swivel hooks (mean ≈ 0.008, SE ≈ 0.002). Further, trips with external observers had higher bycatch estimates (mean ≈ 0.75, SE ≈ 0.16) compared with trips where bycatch was registered by the fishers (mean ≈ 0.02, SE < 0.01). Of the analysed birds, about two-thirds were adult birds and males dominated (71.1%). A majority were in good or moderate condition. The findings suggest that the incidental bycatch in the Greenland halibut fishery along the Norwegian coast is more limited than previous studies indicated, and that the use of swivel hooks can significantly reduce such bycatch. However, the impacts on the red-listed, diminishing population of fulmars breeding in mainland Norway should be assessed further and requires a method to assign killed birds to regions/colonies. Also, gaining a better understanding of what triggers events with extreme bycatch numbers is important to reduce the problem further and to improve bycatch modelling.
The arrangement of Brachypodium distachyon chromosomes in interphase nuclei
Authors: Robaszkiewicz Ewa , Idziak-Helmcke Dominika , Tkacz Magdalena A. , Chrominski Kornel , Hasterok Robert
Published: September 2016

The spatial organization of chromatin within the interphase nucleus and the interactions between chromosome territories (CTs) are essential for various biological processes, such as DNA replication, transcription, and repair. However, detailed data about the CT arrangement in monocotyledonous plants are scarce. In this study, chromosome painting was used to analyse the distribution and associations of individual chromosomes in the 3-D preserved nuclei of Brachypodium distachyon root cells in order to determine the factors that may have an impact on the homologous CT arrangement. It was shown that the frequency of CT association is linked to the steric constraints imposed by the limited space within the nucleus and may depend on chromosome size and morphology as well as on the nuclear shape. Furthermore, in order to assess whether the distribution of interphase chromosomes is random or is subject to certain patterns, a comparison between the experimental data and the results of a computer simulation (ChroTeMo), which was based on a fully probabilistic distribution of the CTs, was performed. This comparison revealed that homologous chromosome arm CTs associate more often than if they were randomly arranged inside the interphase nucleus.
The donor of Aquila X-1 revealed by high-angular resolution near-infrared spectroscopy
Authors: Mata Sánchez D. , Muñoz-Darias T. , Casares J. , Jiménez-Ibarra F.
Published: September 2016

The low-mass X-ray binary Aquila X-1 is one of the most active neutron star X-ray transients. Despite its relatively bright quiescent optical counterpart, the detection of its companion has been hampered by the presence of a nearby interloper star. Using the Spectrograph for INtegral Field Observations in the Near Infrared (SINFONI) on the Very Large Telescope-8.2m telescope, we unambiguously single out Aquila X-1 from the interloper. Phase-resolved near-infrared spectroscopy reveals absorption features from a K4 ± 2 companion star moving at a projected velocity of K2 = 136 ± 4 km s− 1. We here present the first dynamical solution and associated fundamental parameters of Aquila X-1, imposing new constraints on the orbital inclination (36° < i < 47°) and the distance (d = 6 ± 2 kpc) to this prototypical neutron star transient.
Evolution of Natal Dispersal in Spatially Heterogenous Environments
Authors: Cantrell Robert Stephen , Cosner Chris , Lou Yuan , Schreiber Sebastian J.
Published: September 2016

Understanding the evolution of dispersal is an important issue in evolutionary ecology. For continuous time models in which individuals disperse throughout their lifetime, it has been shown that a balanced dispersal strategy, which results in an ideal free distribution, is evolutionary stable in spatially varying but temporally constant environments. Many species, however, primarily disperse prior to reproduction (natal dispersal) and less commonly between reproductive events (breeding dispersal). These species include territorial species such as birds and reef fish, and sessile species such as plants, and mollusks. As demographic and dispersal terms combine in a multiplicative way for models of natal dispersal, rather than the additive way for the previously studied models, we develop new mathematical methods to study the evolution of natal dispersal for continuous-time and discrete-time models. A fundamental ecological dichotomy is identified for the non-trivial equilibrium of these models: (i) the per-capita growth rates for individuals in all patches are equal to zero, or (ii) individuals in some patches experience negative per-capita growth rates, while individuals in other patches experience positive per-capita growth rates. The first possibility corresponds to an ideal-free distribution, while the second possibility corresponds to a “source-sink” spatial structure. We prove that populations with a dispersal strategy leading to an ideal-free distribution displace populations with dispersal strategy leading to a source-sink spatial structure. When there are patches which can not sustain a population, ideal-free strategies can be achieved by sedentary populations, and we show that these populations can displace populations with any irreducible dispersal strategy. Collectively, these results support that evolution selects for natal or breeding dispersal strategies which lead to ideal-free distributions in spatially heterogenous, but temporally homogenous, environments.