bluuebunny/crossref_metadata_2025 huggingface dataset:
Low‐profile omnidirectional antenna for automatic dependent surveillance – broadcast applications
Authors: Yan Sen , Wang Xusheng , Hu Ye , Vandenbosch Guy A.E.
Published: October 2015

A low‐profile omnidirectional patch antenna operating in the dependent surveillance – broadcast band is designed for unmanned aerial vehicles. The antenna works at zero‐order resonance mode and has an omnidirectional radiation pattern. By loading with vias and double split ring resonator slots, a compact size (0.218 × 0.218 × 0.031 λ03) is achieved at 1.09 GHz. The antenna is fabricated and measured. The measured results agree well with the simulated ones. A 20 MHz bandwidth is obtained.
Full Ka‐band right‐angle transition from substrate integrated waveguide to air‐filled rectangular waveguide
Authors: Dong Jun , Yang Ziqiang , Peng Hao , Yang Tao
Published: October 2015

A full Ka‐band right‐angle transition from a substrate integrated waveguide (SIW) to an air‐filled rectangular waveguide is proposed. A two‐step ridged waveguide and the SIW with an etched slot are jointly designed to obtain a better electric field and impedance matching between the SIW and the air‐filled rectangular waveguide. To verify the method, a back‐to‐back transition prototype at Ka‐band is designed, fabricated and measured. The measured results show that the insertion loss of a single transition is <0.55 dB over the entire Ka‐band from 26.5 to 40 GHz. Moreover, the 15 dB fractional bandwidth is increased from 25.7 to 40.9% compared with conventional right‐angle SIW‐to‐waveguide transition. This broadband transition can be a good candidate for broadband millimetre‐wave applications.
Observer synthesis for uncertain Takagi–Sugeno fuzzy systems with multiple output matrices
Authors: Vu Van‐Phong , Wang Wen‐June
Published: October 2015

Designing an observer for Takagi–Sugeno (T–S) fuzzy systems in the presence of uncertainties is a great challenge for researchers. Owing to the uncertainties, it is hard to design an observer to make the state estimation error converge to zero asymptotically. To resolve this problem, the authors consider the uncertainties to be unknown inputs and apply the unknown inputs method. The existing literature concerning observer design for T–S fuzzy systems using the unknown inputs method generally have only a single output matrix. In addition, the method of converting uncertainties into unknown inputs requires a matching condition which includes a common constant matrix to match all uncertainties in all local models of T–S fuzzy system. Therefore, the above two constraints lead the observer design to be very conservative. To overcome the above drawbacks, a special transformation is used to transform the original T–S fuzzy system into a new system form, and then they propose a method to synthesise an observer for an uncertain T–S fuzzy system which allows different output matrices and relaxes the matching condition of the uncertainties for all local models. Finally, two examples are presented to demonstrate the efficiency of the proposed method.
Circuit breaker condition assessment through a fuzzy‐probabilistic analysis of actuating coil's current
Authors: Razi‐Kazemi Ali Asghar
Published: October 2015

Circuit breaker (CB) is a component providing significant electrical protection for power transmission and distribution systems. Hence, an effective condition monitoring system for the CBs is of imminent importance. This study presents a fuzzy‐probabilistic‐based condition assessment algorithm to assess the CB operation performance by monitoring its trip/close coil current (C.C.), and suggests a simple yet effective condition assessment tool. The C.C. patterns are acquired by measurements carried out on 60 CBs (72.5 kV, SF6) under faulty and normal conditions. To intelligently assess the CB's operating state (i.e. normal, alarm and emergency), in terms of its reliability, the optimum C.C. features with minimum interdependence were obtained. Furthermore, a fuzzy‐probabilistic method is proposed based on the results of the statistical analyses of the features. The feasibility and applicability of the proposed method in CB condition assessment is verified against the experimental measured data.
Robust computational framework for mid‐term techno‐economical assessment of energy storage
Authors: Maghouli Pouria , Soroudi Alireza , Keane Andrew
Published: October 2015

Rapid expansion and integration of wind energy is restrained due to transmission capacity constraints and conventional generation technologies limited operational flexibility in today's power systems. Energy storage is an attractive option to integrate and utilise more renewable energy without major and timely upgrade of existing transmission infrastructure. Moreover, it can be considered as a means for differing the reinforcement plans. The evaluation of energy storage deployment projects is a challenging task due to severe uncertainty of wind power generation. In this study, a robust techno‐economic framework is proposed for energy storage evaluation based on information gap decision theory for handling wind generation uncertainty. The total social cost of the system including conventional generators’ fuel and pollution cost and wind power curtailment cost is optimised considering generators operational constraints and transmission system capacity limitations based on the DC model of the power grid. The effect of storage devices on system performance is evaluated taking into account wind power uncertainty. The proposed method is conducted on the modified IEEE reliability test system and the modified IEEE‐118‐bus test system to assess its applicability and performance in mid‐term robust evaluation of energy storage implementation plans.
Visibility of two-dimensional layered materials on various substrates
Authors: Müller M. R. , Gumprich A. , Ecik E. , Kallis K. T. , Winkler F. , Kardynal B. , Petrov I. , Kunze U. , Knoch J.
Published: October 2015

For the investigation of 2D layered materials such as graphene, transition-metal dichalcogenides, boron nitride, and their heterostructures, dedicated substrates are required to enable unambiguous identification through optical microscopy. A systematic study is conducted, focusing on various 2D layered materials and substrates. The simulated colors are displayed and compared with microscopy images. Additionally, the issue of defining an appropriate index for measuring the degree of visibility is discussed. For a wide range of substrate stacks, layer thicknesses for optimum visibility are given along with the resulting sRGB colors. Further simulations of customized stacks can be conducted using our simulation tool, which is available for download and contains a database featuring a wide range of materials.
Development of a tunable Fabry-Perot etalon-based near-infrared interference spectrometer for measurement of the HeI 23S-23P spectral line shape in magnetically confined torus plasmas
Authors: Ogane S. , Shikama T. , Zushi H. , Hasuo M.
Published: October 2015

In magnetically confined torus plasmas, the local emission intensity, temperature, and flow velocity of atoms in the inboard and outboard scrape-off layers can be separately measured by a passive emission spectroscopy assisted by observation of the Zeeman splitting in their spectral line shape. To utilize this technique, a near-infrared interference spectrometer optimized for the observation of the helium 23S–23P transition spectral line (wavelength 1083 nm) has been developed. The applicability of the technique to actual torus devices is elucidated by calculating the spectral line shapes expected to be observed in LHD and QUEST (Q-shu University Experiment with Steady State Spherical Tokamak). In addition, the Zeeman effect on the spectral line shape is measured using a glow-discharge tube installed in a superconducting magnet.
Terahertz radiation induces non-thermal structural changes associated with Fröhlich condensation in a protein crystal
Authors: Lundholm Ida V. , Rodilla Helena , Wahlgren Weixiao Y. , Duelli Annette , Bourenkov Gleb , Vukusic Josip , Friedman Ran , Stake Jan , Schneider Thomas , Katona Gergely
Published: October 2015

Whether long-range quantum coherent states could exist in biological systems, and beyond low-temperature regimes where quantum physics is known to be applicable, has been the subject to debate for decades. It was proposed by Fröhlich that vibrational modes within protein molecules can order and condense into a lowest-frequency vibrational mode in a process similar to Bose-Einstein condensation, and thus that macroscopic coherence could potentially be observed in biological systems. Despite the prediction of these so-called Fröhlich condensates almost five decades ago, experimental evidence thereof has been lacking. Here, we present the first experimental observation of Fröhlich condensation in a protein structure. To that end, and to overcome the challenges associated with probing low-frequency molecular vibrations in proteins (which has hampered understanding of their role in proteins' function), we combined terahertz techniques with a highly sensitive X-ray crystallographic method to visualize low-frequency vibrational modes in the protein structure of hen-egg white lysozyme. We found that 0.4 THz electromagnetic radiation induces non-thermal changes in electron density. In particular, we observed a local increase of electron density in a long α-helix motif consistent with a subtle longitudinal compression of the helix. These observed electron density changes occur at a low absorption rate indicating that thermalization of terahertz photons happens on a micro- to milli-second time scale, which is much slower than the expected nanosecond time scale due to damping of delocalized low frequency vibrations. Our analyses show that the micro- to milli-second lifetime of the vibration can only be explained by Fröhlich condensation, a phenomenon predicted almost half a century ago, yet never experimentally confirmed.
Different approaches to modeling the LANSCE H− ion source filament performance
Authors: Draganic I. N. , O’Hara J. F. , Rybarcyk L. J.
Published: October 2015

An overview of different approaches to modeling of hot tungsten filament performance in the Los Alamos Neutron Science Center (LANSCE) H− surface converter ion source is presented. The most critical components in this negative ion source are two specially shaped wire filaments heated up to the working temperature range of 2600 K–2700 K during normal beam production. In order to prevent catastrophic filament failures (creation of hot spots, wire breaking, excessive filament deflection towards source body, etc.) and to improve understanding of the material erosion processes, we have simulated the filament performance using three different models: a semi-empirical model, a thermal finite-element analysis model, and an analytical model. Results of all three models were compared with data taken during LANSCE beam production. The models were used to support the recent successful transition from the beam pulse repetition rate of 60 Hz–120 Hz.
Sequential memory: Binding dynamics
Authors: Afraimovich Valentin , Gong Xue , Rabinovich Mikhail
Published: October 2015

Temporal order memories are critical for everyday animal and human functioning. Experiments and our own experience show that the binding or association of various features of an event together and the maintaining of multimodality events in sequential order are the key components of any sequential memories—episodic, semantic, working, etc. We study a robustness of binding sequential dynamics based on our previously introduced model in the form of generalized Lotka-Volterra equations. In the phase space of the model, there exists a multi-dimensional binding heteroclinic network consisting of saddle equilibrium points and heteroclinic trajectories joining them. We prove here the robustness of the binding sequential dynamics, i.e., the feasibility phenomenon for coupled heteroclinic networks: for each collection of successive heteroclinic trajectories inside the unified networks, there is an open set of initial points such that the trajectory going through each of them follows the prescribed collection staying in a small neighborhood of it. We show also that the symbolic complexity function of the system restricted to this neighborhood is a polynomial of degree L − 1, where L is the number of modalities.
A decade-spanning high-resolution asynchronous optical sampling terahertz time-domain and frequency comb spectrometer
Authors: Good Jacob T. , Holland Daniel B. , Finneran Ian A. , Carroll P. Brandon , Kelley Matthew J. , Blake Geoffrey A.
Published: October 2015

We present the design and capabilities of a high-resolution, decade-spanning ASynchronous OPtical Sampling (ASOPS)-based TeraHertz Time-Domain Spectroscopy (THz-TDS) instrument. Our system employs dual mode-locked femtosecond Ti:Sapphire oscillators with repetition rates offset locked at 100 Hz via a Phase-Locked Loop (PLL) operating at the 60th harmonic of the ∼80 MHz oscillator repetition rates. The respective time delays of the individual laser pulses are scanned across a 12.5 ns window in a laboratory scan time of 10 ms, supporting a time delay resolution as fine as 15.6 fs. The repetition rate of the pump oscillator is synchronized to a Rb frequency standard via a PLL operating at the 12th harmonic of the oscillator repetition rate, achieving milliHertz (mHz) stability. We characterize the timing jitter of the system using an air-spaced etalon, an optical cross correlator, and the phase noise spectrum of the PLL. Spectroscopic applications of ASOPS-THz-TDS are demonstrated by measuring water vapor absorption lines from 0.55 to 3.35 THz and acetonitrile absorption lines from 0.13 to 1.39 THz in a short pathlength gas cell. With 70 min of data acquisition, a 50 dB signal-to-noise ratio is achieved. The achieved root-mean-square deviation is 14.6 MHz, with a mean deviation of 11.6 MHz, for the measured water line center frequencies as compared to the JPL molecular spectroscopy database. Further, with the same instrument and data acquisition hardware, we use the ability to control the repetition rate of the pump oscillator to enable THz frequency comb spectroscopy (THz-FCS). Here, a frequency comb with a tooth width of 5 MHz is generated and used to fully resolve the pure rotational spectrum of acetonitrile with Doppler-limited precision. The oscillator repetition rate stability achieved by our PLL lock circuits enables sub-MHz tooth width generation, if desired. This instrument provides unprecedented decade-spanning, tunable resolution, from 80 MHz down to sub-MHz, and heralds a new generation of gas-phase spectroscopic tools in the THz region.
An atmospheric pressure high-temperature laminar flow reactor for investigation of combustion and related gas phase reaction systems
Authors: Oßwald Patrick , Köhler Markus
Published: October 2015

A new high-temperature flow reactor experiment utilizing the powerful molecular beam mass spectrometry (MBMS) technique for detailed observation of gas phase kinetics in reacting flows is presented. The reactor design provides a consequent extension of the experimental portfolio of validation experiments for combustion reaction kinetics. Temperatures up to 1800 K are applicable by three individually controlled temperature zones with this atmospheric pressure flow reactor. Detailed speciation data are obtained using the sensitive MBMS technique, providing in situ access to almost all chemical species involved in the combustion process, including highly reactive species such as radicals. Strategies for quantifying the experimental data are presented alongside a careful analysis of the characterization of the experimental boundary conditions to enable precise numeric reproduction of the experimental results. The general capabilities of this new analytical tool for the investigation of reacting flows are demonstrated for a selected range of conditions, fuels, and applications. A detailed dataset for the well-known gaseous fuels, methane and ethylene, is provided and used to verify the experimental approach. Furthermore, application for liquid fuels and fuel components important for technical combustors like gas turbines and engines is demonstrated. Besides the detailed investigation of novel fuels and fuel components, the wide range of operation conditions gives access to extended combustion topics, such as super rich conditions at high temperature important for gasification processes, or the peroxy chemistry governing the low temperature oxidation regime. These demonstrations are accompanied by a first kinetic modeling approach, examining the opportunities for model validation purposes.
High-temperature apparatus for chaotic mixing of natural silicate melts
Authors: Morgavi D. , Petrelli M. , Vetere F. P. , González-García D. , Perugini D.
Published: October 2015

A unique high-temperature apparatus was developed to trigger chaotic mixing at high-temperature (up to 1800 °C). This new apparatus, which we term Chaotic Magma Mixing Apparatus (COMMA), is designed to carry out experiments with high-temperature and high-viscosity (up to 106 Pa s) natural silicate melts. This instrument allows us to follow in time and space the evolution of the mixing process and the associated modulation of chemical composition. This is essential to understand the dynamics of magma mixing and related chemical exchanges. The COMMA device is tested by mixing natural melts from Aeolian Islands (Italy). The experiment was performed at 1180 °C using shoshonite and rhyolite melts, resulting in a viscosity ratio of more than three orders of magnitude. This viscosity ratio is close to the maximum possible ratio of viscosity between high-temperature natural silicate melts. Results indicate that the generated mixing structures are topologically identical to those observed in natural volcanic rocks highlighting the enormous potential of the COMMA to replicate, as a first approximation, the same mixing patterns observed in the natural environment. COMMA can be used to investigate in detail the space and time development of magma mixing providing information about this fundamental petrological and volcanological process that would be impossible to investigate by direct observations. Among the potentials of this new experimental device is the construction of empirical relationships relating the mixing time, obtained through experimental time series, and chemical exchanges between the melts to constrain the mixing-to-eruption time of volcanic systems, a fundamental topic in volcanic hazard assessment.
A collisional radiative model of hydrogen plasmas developed for diagnostic purposes of negative ion sources
Authors: Iordanova Snejana , Paunska Tsvetelina
Published: October 2015

A collisional radiative model of low-pressure hydrogen plasmas is elaborated and applied in optical emission spectroscopy diagnostics of a single element of a matrix source of negative hydrogen ions. The model accounts for the main processes determining both the population densities of the first ten states of the hydrogen atom and the densities of the positive hydrogen ions H+, H2+, and H3+. In the calculations, the electron density and electron temperature are varied whereas the atomic and molecular temperatures are included as experimentally obtained external parameters. The ratio of the Hα to Hβ line intensities is calculated from the numerical results for the excited state population densities, obtained as a solution of the set of the steady-state rate balance equations. The comparison of measured and theoretically obtained ratios of line intensities yields the values of the electron density and temperature as well as of the degree of dissociation, i.e., of the parameters which have a crucial role for the volume production of the negative ions.
Theory of activated penetrant diffusion in viscous fluids and colloidal suspensions
Authors: Zhang Rui , Schweizer Kenneth S.
Published: October 2015

We heuristically formulate a microscopic, force level, self-consistent nonlinear Langevin equation theory for activated barrier hopping and non-hydrodynamic diffusion of a hard sphere penetrant in very dense hard sphere fluid matrices. Penetrant dynamics is controlled by a rich competition between force relaxation due to penetrant self-motion and collective matrix structural (alpha) relaxation. In the absence of penetrant-matrix attraction, three activated dynamical regimes are predicted as a function of penetrant-matrix size ratio which are physically distinguished by penetrant jump distance and the nature of matrix motion required to facilitate its hopping. The penetrant diffusion constant decreases the fastest with size ratio for relatively small penetrants where the matrix effectively acts as a vibrating amorphous solid. Increasing penetrant-matrix attraction strength reduces penetrant diffusivity due to physical bonding. For size ratios approaching unity, a distinct dynamical regime emerges associated with strong slaving of penetrant hopping to matrix structural relaxation. A crossover regime at intermediate penetrant-matrix size ratio connects the two limiting behaviors for hard penetrants, but essentially disappears if there are strong attractions with the matrix. Activated penetrant diffusivity decreases strongly with matrix volume fraction in a manner that intensifies as the size ratio increases. We propose and implement a quasi-universal approach for activated diffusion of a rigid atomic/molecular penetrant in a supercooled liquid based on a mapping between the hard sphere system and thermal liquids. Calculations for specific systems agree reasonably well with experiments over a wide range of temperature, covering more than 10 orders of magnitude of variation of the penetrant diffusion constant.
Research of weak pulsed magnetic field system derived from the time, displacement, and static magnetic field
Authors: Zhao Xiao-Dong , Qian Zheng
Published: October 2015

The accurate measurement of dynamic characteristics in weak magnetic sensors is urgently required as a greater number of applications for these devices are found. In this paper, a novel weak pulsed magnetic field system is presented. The underlying principle is to drive a permanent magnet passing another magnet rapidly, producing a pulsed weak magnetic field. The magnitude of the field can be adjusted by changing the velocity and distance between the two magnets. The standard value of the pulsed dynamic magnetic field can be traced back to the accurate measurement of time, displacement, and static magnetic field. In this study a detailed procedure for producing a pulse magnetic field system using the above method is outlined after which a theoretical analysis of the permanent magnet movement is discussed. Using the described apparatus a milli-second level pulse-width with a milli-Tesla magnetic field magnitude is used to study the dynamic characteristics of a giant magnetoresistance sensor. We conclude by suggesting possible improvements to the described apparatus.
Calculation of photodetachment cross sections and photoelectron angular distributions of negative ions using density functional theory
Authors: Liu Yuan , Ning Chuangang
Published: October 2015

Recently, the development of photoelectron velocity map imaging makes it much easier to obtain the photoelectron angular distributions (PADs) experimentally. However, explanations of PADs are only qualitative in most cases, and very limited works have been reported on how to calculate PAD of anions. In the present work, we report a method using the density-functional-theory Kohn-Sham orbitals to calculate the photodetachment cross sections and the anisotropy parameter β. The spherical average over all random molecular orientation is calculated analytically. A program which can handle both the Gaussian type orbital and the Slater type orbital has been coded. The testing calculations on Li−, C−, O−, F−, CH−, OH−, NH2−, O2−, and S2− show that our method is an efficient way to calculate the photodetachment cross section and anisotropy parameter β for anions, thus promising for large systems.
Low-energy ion beam-based deposition of gallium nitride
Authors: Vasquez M. R. , Wada M.
Published: October 2015

An ion source with a remote plasma chamber excited by a 13.56 MHz radio frequency power was used for low-energy broad ion beam extraction. Optical emission spectral analyses showed the sputtering and postionization of a liquid gallium (Ga) target placed in a chamber separated from the source bombarded by argon (Ar) plasma guided by a bent magnetic field. In addition, an E × B probe successfully showed the extraction of low-energy Ga and Ar ion beams using a dual-electrode extractor configuration. By introducing dilute amounts of nitrogen gas into the system, formation of thin Ga-based films on a silicon substrate was demonstrated as determined from X-ray diffraction and X-ray reflectivity studies.
Quantum state-resolved differential cross sections for complex-forming chemical reactions: Asymmetry is the rule, symmetry the exception
Authors: Larrégaray Pascal , Bonnet Laurent
Published: October 2015

We argue that statistical theories are generally unable to accurately predict state-resolved differential cross sections for triatomic bimolecular reactions studied in beam experiments, even in the idealized limit where the dynamics are fully chaotic. The basic reason is that quenching of interferences between partial waves is less efficient than intuitively expected, especially around the poles.
Critical density for Landau damping in a two-electron-component plasma
Authors: Rupp Constantin F. , López Rodrigo A. , Araneda Jaime A.
Published: October 2015

The asymptotic evolution of an initial perturbation in a collisionless two-electron-component plasma with different temperatures is studied numerically. The transition between linear and nonlinear damping regimes is determined by slowly varying the density of the secondary electron-component using high-resolution Vlasov-Poisson simulations. It is shown that, for fixed amplitude perturbations, this transition behaves as a critical phenomenon with time scales and field amplitudes exhibiting power-law dependencies on the threshold density, similar to the critical amplitude behavior in a single-component plasma.
Near infrared microcoupler with multilayer isotropic metamaterials
Authors: Li Kun , Tian Chao , Liu Shengchun , Zhang Jintao , Lv Houjun , Zhu Xuefeng
Published: October 2015

This paper reports the design of a microcoupler in the near-infrared region. The proposed structure consists of two alternately arranged complementary media. The complementary media, which consist of double-positive material and double-negative material, also can be made of a pair of single-negative materials. Simulation results show that the proposed structure has an excellent coupling efficiency compared to direct coupling. It has a maximum coupling efficiency closing to 1 at 1550 nm. As the total size of the coupling structure decreases, the passband exhibits a property of gradual blue shift. Therefore, we can design couplers operating in different frequency bands with high coupling efficiency. The influence of the permittivity and the thickness of each material layer on the coupling efficiency are also studied in detail. The proposed microcoupler has potential guidance in the design and development of high-performance coupling structures.
Y-doped La0.7Ca0.3MnO3 manganites exhibiting a large magnetocaloric effect and the crossover of first-order and second-order phase transitions
Authors: Phan The-Long , Ho T. A. , Manh T. V. , Dang N. T. , Jung C. U. , Lee B. W. , Thanh T. D.
Published: October 2015

We prepared orthorhombic La0.7−xYxCa0.3MnO3 samples (x = 0, 0.04, 0.06, and 0.08) by conventional solid-state reaction and then studied their magnetic properties and magnetocaloric (MC) effect based on magnetization versus temperature and magnetic-field measurements, M(T, H). The experimental results revealed that an x increase in La0.7−xYxCa0.3MnO3 reduced the ferromagnetic-paramagnetic transition temperature (TC) from 260 K (for x = 0) to ∼126 K (for x = 0.08). Around the TC, maximum magnetic-entropy changes for a magnetic-field variation interval H = 50 kOe are about 10.7, 8.5, 7.4, and 5.8 J·kg−1·K−1 for x = 0, 0.04, 0.06, and 0.08, respectively, corresponding to refrigerant capacities RC = 250–280 J·kg−1. These values are comparable to those of some conventional MC materials, revealing the applicability of La0.7−xYxCa0.3MnO3 in magnetic refrigeration. Using the Arrott method and scaling hypothesis as analyzing high-field M(H, T) data, and the universal-curve construction of the magnetic entropy change, we found a magnetic-phase separation. While the samples x = 0−0.06 exhibit a first-order magnetic phase transition, x = 0.08 exhibits the crossover of the first-to-second-order phase transformation (with its critical-exponent values close to those expected for the tricritical mean-field theory) and has the presence of ferromagnetic clusters even above the TC. Such the variations in the magnetism and MC effect are related to the changes in structural parameters caused by the Y substitution for La because Y doping does not change the concentration ratio of Mn3+/Mn4+.
Strategy for improved frequency response of electric double-layer capacitors
Authors: Wada Yoshifumi , Pu Jiang , Takenobu Taishi
Published: October 2015

We propose a strategy for improving the response speed of electric double-layer capacitors (EDLCs) and electric double-layer transistors (EDLTs), based on an asymmetric structure with differently sized active materials and gate electrodes. We validate the strategy analytically by a classical calculation and experimentally by fabricating EDLCs with asymmetric Au electrodes (1:50 area ratio and 7.5 μm gap distance). The performance of the EDLCs is compared with that of conventional symmetric EDLCs. Our strategy dramatically improved the cut-off frequency from 14 to 93 kHz and this improvement is explained by fast charging of smaller electrodes. Therefore, this approach is particularly suitable to EDLTs, potentially expanding the applicability to medium speed (kHz–MHz) devices.
Enhanced thermal conductivity in off-stoichiometric La-(Fe,Co)-Si magnetocaloric alloys
Authors: Shao Yanyan , Zhang Mingxiao , Luo Hubin , Yan Aru , Liu Jian
Published: October 2015

A dual-phase structure consisting of the NaZn13-type (1:13) matrix and a secondary (Fe,Co)-Si phase is designed in Fe-rich La-(Fe,Co)-Si compounds. As the extra-Fe doping altered Co content of the 1:13 phase, the magnetic entropy change keeps to be a relatively large magnitude of 6.7–7.7 J/kg K in 265–290 K for 2 T field change. In addition, mechanical properties were apparently improved by second-phase strengthening. The primary significance in this work is that the composition modification in matrix phase brings about a drastic increase in the thermal conductivity, which can be ascribed to the weakening effect of phonon point-defect-scattering. On the basis of Neilsen two-phase system model, the electrical conductivity of dispersed (Fe,Co)-Si phase plays very limited contribution to the enhanced thermal transport properties in composites. Our results demonstrate that the combined merits of high thermal conductivity, improved mechanical properties, large magnetic entropy change, and tunable transition temperature can be simultaneously realized in Fe-rich La-(Fe,Co)-Si composite materials.
Communication: X-ray coherent diffractive imaging by immersion in nanodroplets
Authors: Tanyag Rico Mayro P. , Bernando Charles , Jones Curtis F. , Bacellar Camila , Ferguson Ken R. , Anielski Denis , Boll Rebecca , Carron Sebastian , Cryan James P. , Englert Lars , Epp Sascha W. , Erk Benjamin , Foucar Lutz , Gomez Luis F. , Hartmann Robert , Neumark Daniel M. , Rolles Daniel , Rudek Benedikt , Rudenko Artem , Siefermann Katrin R. , Ullrich Joachim , Weise Fabian , Bostedt Christoph , Gessner Oliver , Vilesov Andrey F.
Published: October 2015

Lensless x-ray microscopy requires the recovery of the phase of the radiation scattered from a specimen. Here, we demonstrate a de novo phase retrieval technique by encapsulating an object in a superfluid helium nanodroplet, which provides both a physical support and an approximate scattering phase for the iterative image reconstruction. The technique is robust, fast-converging, and yields the complex density of the immersed object. Images of xenon clusters embedded in superfluid helium droplets reveal transient configurations of quantum vortices in this fragile system.
Effect of late gestation bodyweight change and condition score on progeny feedlot performance
Authors: Mulliniks J. T. , Sawyer J. E. , Harrelson F. W. , Mathis C. P. , Cox S. H. , Löest C. A. , Petersen M. K.
Published: October 2015

Inadequate nutrient intake during late gestation can cause cow bodyweight (BW) loss and influence cow reproductive performance and subsequent productivity of steer progeny. Therefore, a 7-year study with a 3 × 3 arrangement of treatments was conducted at Corona Range and Livestock Research Centre, Corona, New Mexico to evaluate the effects of cow BW change and body condition score (BCS) during late gestation on subsequent cow pregnancy rates, progeny steer feedlot performance, and health. Cows were retrospectively classified to 1 of 3 BW change groups: (1) cows that lost BW during late gestation (LOSS; mean –26 ± 2 kg); (2) cows that maintained BW during late gestation (MAIN; mean –1 ± 1 kg); or (3) cows that gained BW during late gestation (GAIN; mean 25 ± 2 kg). Cows were also classified to 1 of 3 BCS groups: BCS of 4 (mean BCS = 4.0 ± 0.02; range 4.0–4.5), 5 (mean BCS = 5.0 ± 0.02; range 5.0–5.5), or 6 (mean BCS = 6.0 ± 0.02; range 6.0–6.5). After weaning each year, steers were preconditioned for 45 days and were received and treated as custom-fed commercial cattle at a feedlot in mid-November. Calf weaning BW, initial feedlot BW, final BW, and hot carcass weight were unaffected (P ≥ 0.22) by dam’s prepartum BW change or BCS. However, steers from GAIN and MAIN tended (P = 0.06) to have increased ADG in the feedlot. Twelfth-rib fat thickness, longissimus muscle area, and days on feed were not influenced (P ≥ 0.18) by late gestation BW change or BCS. Calves from BCS 6 cows tended (P = 0.10) to have greater yield grades at harvest in the feedlot. Percentage of steers grading Choice or greater was increased (P < 0.01) in steers from LOSS cows and cows in BCS 4 during late gestation compared with other groups. These data suggest that modest nutrient restriction during late gestation can have a minimal effect on growth and performance of steer progeny from birth through the finishing phase.
Sperm DNA fragmentation in cryopreserved samples from subjects with different cancers
Authors: Tamburrino Lara , Cambi Marta , Marchiani Sara , Manigrasso Ilaria , Degl'Innocenti Selene , Forti Gianni , Maggi Mario , Baldi Elisabetta , Muratori Monica
Published: October 2015

Sperm cryopreservation is widely used by cancer patients undergoing chemo- or radiotherapy. Evidence suggests that IVF outcome with cryopreserved spermatozoa from cancer patients is less successful. To determine whether sperm DNA fragmentation (SDF) is involved in the lower fertilising ability of cryopreserved spermatozoa of cancer patients, SDF was evaluated in thawed spermatozoa from 78 men affected by different cancers and 53 men with non-cancer pathologies. SDF was assessed by the terminal deoxyribonucleotidyl transferase-mediated dUTP–digoxigenin nick end-labelling (TUNEL), propidium iodide (PI), flow cytometry procedure, which allows determination of two different cell populations (PIbrighter and PIdimmer) and thus to determine the percentage of DNA fragmented sperm in both. PIdimmer spermatozoa are totally unviable, whereas PIbrighter spermatozoa with SDF may be motile and morphologically normal, having higher biological relevance in the reproductive process. We found that the proportion of DNA fragmented PIbrighter cells was significantly higher in thawed spermatozoa from cancer than non-cancer patients. Moreover, a positive correlation was found between the degree of DNA fragmentation and sperm motility in the PIbrighter population of spermatozoa from cancer patients that wasn’t seen in non-cancer patients. The results of the present study suggest that higher SDF levels may contribute to the lower IVF success of cryopreserved spermatozoa from cancer patients and that evaluation of SDF could complement genetic counselling as part of the routine management of cancer patients who seek fertility preservation.
Effect of bovine oviductal fluid on development and quality of bovine embryos produced in vitro
Authors: Lopera-Vasquez Ricaurte , Hamdi Meriem , Maillo Veronica , Lloreda Valeriano , Coy Pilar , Gutierrez-Adan Alfonso , Bermejo-Alvarez Pablo , Rizos Dimitrios
Published: October 2015

To evaluate the effect of bovine oviductal fluid (OF) supplementation during in vitro culture of bovine embryos on their development and quality, in vitro-produced zygotes were cultured in synthetic oviductal fluid (SOF; negative control; C–) supplemented with OF or 5% fetal calf serum (positive control; C+). Embryo development was recorded on Days 7–9 after insemination and blastocyst quality was assessed through cryotolerance, differential cell counting of the inner cell mass and trophectoderm, and gene expression. OF was added to the culture medium at concentrations ranging from 0.625% to 25%. The higher OF concentrations (5%, 10% and 25%) had a detrimental effect on embryo development. Lower OF concentrations (1.25% and 0.625%) supported embryo development until Day 9 (27.5%) and produced higher-quality blastocysts, as reflected by their cryotolerance (53.6% and 57.7% survival at 72 h, respectively, vs 25.9% in C+) and total cell number (mean (± s.e.m.) 165.1 ± 4.7 and 156.2 ± 4.2, respectively, vs 127.7 ± 4.9 in C– and 143.1 ± 4.9 in C+). Consistent with these data, upregulation of the water channel aquaporin 3 (AQP3) mRNA was observed in blastocysts supplemented with 1.25% OF compared with C– and C+. Serum supplementation resulted in a reduction in the expression of glucose and lipid metabolism-related genes and downregulation of the epigenetic-related genes DNA methyltransferase 3A (DNMT3A) and insulin-like growth factor 2 receptor (IGF2R). In conclusion, in vitro culture with low concentrations of OF has a positive effect on the development and quality of bovine embryos.
The assessment of sperm DNA fragmentation in the saltwater crocodile (Crocodylus porosus)
Authors: Johnston S. D. , López-Fernández C. , Arroyo F. , Fernández J. L. , Gosálvez J.
Published: October 2015

Herein we report a method of assessing DNA fragmentation in the saltwater crocodile using the sperm chromatin dispersion test (SCDt) after including frozen–thawed spermatozoa in a microgel (Halomax; Halotech DNA, Madrid, Spain). Following controlled protein depletion, which included a reducing agent, sperm nuclei with fragmented DNA showed a homogeneous and larger halo of chromatin dispersion with a corresponding reduced nucleoid core compared with sperm with non-fragmented DNA. The presence of DNA damage was confirmed directly by incorporation of modified nucleotides using in situ nick translation (ISNT) and indirectly by studying the correlation of the SCDt with the results of DNA damage visualisation using a two-tailed comet assay (r = 0.90; P = 0.037). Results of the SCDt immediately following thawing and after 5 h incubation at 37°C in order to induce a range of DNA damage revealed individual crocodile differences in both the baseline level of DNA damage and DNA longevity.
Weak genetic structuring suggests historically high genetic connectivity among recently fragmented urban populations of the scincid lizard, Ctenotus fallens
Authors: Krawiec Josef , Krauss Siegfried L. , Davis Robert A. , Spencer Peter B. S.
Published: October 2015

Populations in fragmented urban remnants may be at risk of genetic erosion as a result of reduced gene flow and elevated levels of inbreeding. This may have serious genetic implications for the long-term viability of remnant populations, in addition to the more immediate pressures caused by urbanisation. The population genetic structure of the generalist skink Ctenotus fallens was examined using nine microsatellite markers within and among natural vegetation remnants within a highly fragmented urban matrix in the Perth metropolitan area in Western Australia. These data were compared with samples from a large unfragmented site on the edge of the urban area. Overall, estimates of genetic diversity and inbreeding within all populations were similar and low. Weak genetic differentiation, and a significant association between geographic and genetic distance, suggests historically strong genetic connectivity that decreases with geographic distance. Due to recent fragmentation, and genetic inertia associated with low genetic diversity and large population sizes, it is not possible from these data to infer current genetic connectivity levels. However, the historically high levels of gene flow that our data suggest indicate that a reduction in contemporary connectivity due to fragmentation in C. fallens is likely to result in negative genetic consequences in the longer term.
Numbat nirvana: conservation ecology of the endangered numbat (Myrmecobius fasciatus) (Marsupialia : Myrmecobiidae) reintroduced to Scotia and Yookamurra Sanctuaries, Australia
Authors: Hayward Matt W. , Poh Aline Si Lin , Cathcart Jennifer , Churcher Chris , Bentley Jos , Herman Kerryn , Kemp Leah , Riessen Noel , Scully Phil , Diong Cheong Hoong , Legge Sarah , Carter Andrew , Gibb Heloise , Friend J. Anthony
Published: October 2015

Despite a vigorous reintroduction program between 1985 and 2010, numbat populations in Western Australia are either static or declining. This study aimed to document the population ecology of numbats at two sites that are going against this trend: Scotia Sanctuary in far western New South Wales and Yookamurra Sanctuary in the riverland of South Australia. Scotia (64 659 ha) and Yookamurra (5026 ha) are conservation reserves owned and managed by the Australian Wildlife Conservancy and where numbats were reintroduced in 1999 and 1993 respectively. Both sites have large conservation-fence-protected introduced-species-free areas where there are no cats (Felis catus) or red foxes (Vulpes vulpes). Numbats were sourced from both wild and captive populations. From small founder populations, the Scotia numbats are now estimated to number 169 (113–225) with 44 at Yookamurra. Radio-collared individuals at Scotia were active between 13 and 31°C. Females had home ranges of 28.3 ± 6.8 ha and males 96.6 ± 18.2 ha, which leads to an estimated sustainable population or carrying capacity of 413–502 at Scotia. Captive-bred animals from Perth Zoo had a high mortality rate upon reintroduction at Scotia due to predation by raptors and starvation. The habitat preferences for mallee with a shrub understorey appear to be driven by availability of termites, and other reintroduced ecosystem engineers appear to have been facilitators by creating new refuge burrows for numbats. This study shows that numbats can be successfully reintroduced into areas of their former range if protected from introduced predators, and illustrates the difficulties in monitoring such cryptic species.
Socrates, the primary question, and the unity of virtue
Authors: Clark Justin C.
Published: October 2015

For Socrates, the virtues are a kind of knowledge, and the virtues form a unity. Sometimes, Socrates suggests that the virtues are all ‘one and the same’ thing. Other times, he suggests they are ‘parts of a single whole.’ I argue that (i) the ‘what is x?’ question is sophisticated, it gives rise to two distinct kinds of investigations into virtue, a conceptual investigation into the ousia and a psychological investigation into the dunamis, (ii) Plato recognized the difference between definitional accounts of the ousia and a psychological accounts of the dunamis, and (iii) the distinction between these two investigations can effectively resolve various interpretive puzzles regarding the unity of the virtues. It is argued that the virtues are ‘one and the same’ psychologically, while they are ‘parts of a single whole’ conceptually.
Reducing discards in a temperate prawn trawl fishery: a collaborative approach to bycatch research in South Australia
Authors: Gorman Daniel , Dixon Cameron
Published: October 2015

We present the outcomes of a collaborative research programme tasked with reducing bycatch, and thus discards in a temperate Australian prawn trawl fishery. Sea trials in the Gulf of St Vincent, South Australia, assessed the performance of a modified trawlnet that incorporated a rigid polyethylene grid and a T90-mesh codend. Compared with conventional designs, the modified net yielded marked reductions in bycatch (cumulatively >81% by weight), with pronounced decreases in sponge (92%), elasmobranchs (80%), teleost fish (71%), molluscs (61%), and crustaceans (78%). Using commercial logbook data, we estimate that the use of modified nets could reduce discards by ∼240 tons per year. This outcome was achieved with moderate declines in the catch rate (kg h−1) of the target species, Western King Prawn (mean ∼15%), of which almost all were small adults of low commercial value. Adoption of the modified net by industry was realized in March 2012, because it met environmental objectives (i.e. reducing bycatch and improving public perceptions of sustainability), reduced prawn damage, demonstrated commensurate financial returns, and engaged stakeholders throughout the development process. Overall, the project provides a useful example of bycatch research with demonstrable outcomes of improving the ecological and economic sustainability of prawn harvests.
Constraints on the minor merging and star formation history of the Wolf–Rayet galaxy NGC 5430 through observations
Authors: Pan Hsi-An , Kuno Nario , Sorai Kazuo , Umei Michiko
Published: October 2015

We used multi-wavelength analysis of the newly observed molecular gas [12CO and 13CO(1–0)] with interferometer CARMA and archival star formation tracers to constrain the interaction, merging, and star formation history of an off-center minor merger, a three-spiral barred galaxy NGC 5430 and its satellite embedded in the bar. Morphology of the molecular gas in the bar of NGC 5430 shows minimal signs of recent interactions with our resolution. The apparent morphological remnant of the past galaxy interaction is an asymmetric spiral arm, containing more molecular gas and exhibiting higher star formation rate (SFR) surface density than the two primary arms. Rotation curve analysis suggests that NGC 5430 collided with its satellite several Gyr ago. History of star formation was constrained by using SFRs that trace different timescales (infrared, radio continuum, and Hα). The collision occurred 5–10 Myr ago, triggering a transient off-center starburst of Wolf–Rayet stars at the eastern bar end. In the past, the global SFR during the Wolf–Rayet starburst peaked at 35 M⊙ yr−1. At present, the merger-driven starburst is rapidly decaying and the current global SFR has decreased to the Galactic value. The SFR will continue to decay as suggested by the present amount of dense gas [traced by HCN(1–0)]. Nonetheless, the global SFR is still dominated by the Wolf–Rayet region rather than the circumnuclear region. Compared with other barred galaxies, the circumnuclear region exhibits a particularly low dense gas fraction, low star formation activity, and high concentration of gas. Physical properties of the molecular gas are inferred by using the large velocity gradient calculations. The initial mass ratio of NGC 5430 to its satellite is suggested to be in an intermediate ratio range of 7:1–20:1.