bluuebunny/crossref_metadata_2025 huggingface dataset:
Polarisation‐insensitive and wide‐angle multi‐layer metamaterial absorber with variable bandwidths
Authors: Ghosh S. , Bhattacharyya S. , Chaurasiya D. , Srivastava K.V.
Published: June 2015

Three different metamaterial absorbers based on ultra‐thin multi‐layer structures, with different bandwidth characteristics, are presented. The proposed structure is composed of three vertically stacked metal‐dielectric layers backed by a metal ground. All the metallic patches are of crossed dipole shape and have different geometrical dimensions, which can be manipulated to design triple‐band, 3 dB and 10 dB absorbers separately. The designed structures are polarisation‐insensitive as well as wide‐angle absorptive for both TE and TM polarisations. The 10 dB broadband structure, exhibiting an absorption bandwidth of 7.5% at 10 GHz, has been fabricated and the absorption performance has been verified with the simulated response. The proposed absorber has the advantages of ultra‐thin thickness (λ0/50 corresponding to the centre frequency), compact size, simpler design, tunable absorption bandwidth and experimental validation, which makes it a promising candidate for many potential applications.
Evaluation of polarisation characteristics of power‐line RCS at 76 GHz for helicopter obstacle detection
Authors: Futatsumori S. , Morioka K. , Kohmura A. , Shioji M. , Yonemoto N.
Published: June 2015

The polarisation characteristics of a high‐voltage power‐line radar cross‐section (RCS) at 76 GHz are experimentally evaluated to improve the detection conditions of the helicopter obstacle detection radar system. Vertical polarisation transmission and reception (V–V) are normally used to detect power lines. In addition to V–V polarisation, horizontal transmission and reception (H–H) polarisation characteristics are measured for the two types of high‐voltage power lines. For V–V polarisation, the measured RCS characteristics of the power lines agree well with those previously reported at 35 and 94 GHz. However, the measured results of the H–H polarisation are almost the same as, or higher than, those of the V–V polarisation.
Comparison of two‐step and one‐step motion compensation algorithms for airborne synthetic aperture radar
Authors: Yang Mingdong , Zhu Daiyin , Song Wei
Published: June 2015

Airborne synthetic aperture radar (SAR) image quality considerably degrades because of motion errors. High‐precision motion compensation (MOCO) is necessary in an advanced SAR data processing scheme. In the case of ultra‐high resolution, the conventional two‐step MOCO algorithm introduces significant range cell migration correction (RCMC) error which causes a loss to resolution. Another method named one‐step MOCO can avoid RCMC error, improving image quality obviously. Meanwhile, one‐step MOCO can well integrate with the standard Omega‐K algorithm succinctly. A comparison of the two MOCO algorithms is demonstrated by analysing the RCMC error. Point targets simulation has validated the proposed research.
Fluence thresholds for grazing incidence hard x-ray mirrors
Authors: Aquila A. , Sobierajski R. , Ozkan C. , Hájková V. , Burian T. , Chalupský J. , Juha L. , Störmer M. , Bajt S. , Klepka M. T. , Dłużewski P. , Morawiec K. , Ohashi H. , Koyama T. , Tono K. , Inubushi Y. , Yabashi M. , Sinn H. , Tschentscher T. , Mancuso A. P. , Gaudin J.
Published: June 2015

X-ray Free Electron Lasers (XFELs) have the potential to contribute to many fields of science and to enable many new avenues of research, in large part due to their orders of magnitude higher peak brilliance than existing and future synchrotrons. To best exploit this peak brilliance, these XFEL beams need to be focused to appropriate spot sizes. However, the survivability of X-ray optical components in these intense, femtosecond radiation conditions is not guaranteed. As mirror optics are routinely used at XFEL facilities, a physical understanding of the interaction between intense X-ray pulses and grazing incidence X-ray optics is desirable. We conducted single shot damage threshold fluence measurements on grazing incidence X-ray optics, with coatings of ruthenium and boron carbide, at the SPring-8 Angstrom compact free electron laser facility using 7 and 12 keV photon energies. The damage threshold dose limits were found to be orders of magnitude higher than would naively be expected. The incorporation of energy transport and dissipation via keV level energetic photoelectrons accounts for the observed damage threshold.
A systematic benchmark of the ab initio Bethe-Salpeter equation approach for low-lying optical excitations of small organic molecules
Authors: Bruneval Fabien , Hamed Samia M. , Neaton Jeffrey B.
Published: June 2015

The predictive power of the ab initio Bethe-Salpeter equation (BSE) approach, rigorously based on many-body Green’s function theory but incorporating information from density functional theory, has already been demonstrated for the optical gaps and spectra of solid-state systems. Interest in photoactive hybrid organic/inorganic systems has recently increased and so has the use of the BSE for computing neutral excitations of organic molecules. However, no systematic benchmarks of the BSE for neutral electronic excitations of organic molecules exist. Here, we study the performance of the BSE for the 28 small molecules in Thiel’s widely used time-dependent density functional theory benchmark set [Schreiber et al., J. Chem. Phys. 128, 134110 (2008)]. We observe that the BSE produces results that depend critically on the mean-field starting point employed in the perturbative approach. We find that this starting point dependence is mainly introduced through the quasiparticle energies obtained at the intermediate GW step and that with a judicious choice of starting mean-field, singlet excitation energies obtained from BSE are in excellent quantitative agreement with higher-level wavefunction methods. The quality of the triplet excitations is slightly less satisfactory.
Jacobi multipliers, non-local symmetries, and nonlinear oscillators
Authors: Cariñena J. F. , de Lucas J. , F. Rañada M.
Published: June 2015

Constants of motion, Lagrangians, and Hamiltonians admitted by a family of relevant nonlinear oscillators are derived using a geometric formalism. The theory of the Jacobi last multiplier allows us to find Lagrangian descriptions and constants of the motion. An application of the jet bundle formulation of symmetries of differential equations is presented in the second part of the paper. After a short review of the general formalism, the particular case of non-local symmetries is studied in detail by making use of an extended formalism. The theory is related to some results previously obtained by Krasil’shchik, Vinogradov, and coworkers. Finally, the existence of non-local symmetries for such two nonlinear oscillators is proved.
Note: On the wavelength dependence of the intensity calibration factor of extreme ultraviolet spectrometer determined with profile measurement of bremsstrahlung continuum
Authors: Yamaguchi N. , Morita S. , Dong C. F. , Goto M. , Maezawa H. , Miyauchi H.
Published: June 2015

The absolute calibration factor of extreme ultraviolet spectroscopic instrument which has recently been determined from absolute radiation profile measurement of bremsstrahlung continuum has been investigated by comparing the calculated diffraction efficiency of grating. An overall tendency of the wavelength dependence of the calibration factor from 40 Å to 500 Å can be reproduced by that of the grating efficiency, especially the agreement between the measured calibration factor and the calculated grating efficiency has been found to be fairly good for the wavelength range 200 Å-500 Å.
A generalized Derjaguin approximation for electrical-double-layer interactions at arbitrary separations
Authors: Schnitzer Ory , Morozov Matvey
Published: June 2015

Derjaguin’s approximation provides the electrical-double-layer interaction force between two arbitrary convex surfaces as the product of the corresponding one-dimensional parallel-plate interaction potential and an effective radius R (function of the radii of curvature and relative orientation of the two surfaces at minimum separation). The approximation holds when both the Debye length 1/κ and minimum separation h are small compared to R. We show here that a simple transformation, R⇒[R][K1][K2]K1K2, yields an approximation uniformly valid for arbitrary separations h; here, Ki is the Gaussian curvature of particle i at minimum separation, and [  ⋅  ] is an operator which adds h/2 to all radii of curvature present in the expression on which it acts. We derive this result in two steps. First, we extend the two-dimensional ray-theory analysis of Schnitzer [Phys. Rev. E 91, 022307 (2015)], valid for κh, κR ≫ 1, to three dimensions. We thereby obtain a general closed form expression for the force by matching nonlinear diffuse-charge boundary layers with a WKBJ-type expansion describing the bulk potential, and subsequent integration via Laplace’s method of the traction over the medial surface generated by all spheres maximally inscribed between the two surfaces. Second, we exploit the existence of an overlap domain, 1 ≪ κh ≪ κR, where both the ray-theory and the Derjaguin approximations hold, to systematically form the generalized mapping. The validity of the result is demonstrated by comparison with numerical computations.
Hydrodynamic and kinetic models for spin-1/2 electron-positron quantum plasmas: Annihilation interaction, helicity conservation, and wave dispersion in magnetized plasmas
Authors: Andreev Pavel A.
Published: June 2015

We discuss the complete theory of spin-1/2 electron-positron quantum plasmas, when electrons and positrons move with velocities mach smaller than the speed of light. We derive a set of two fluid quantum hydrodynamic equations consisting of the continuity, Euler, spin (magnetic moment) evolution equations for each species. We explicitly include the Coulomb, spin-spin, Darwin and annihilation interactions. The annihilation interaction is the main topic of the paper. We consider the contribution of the annihilation interaction in the quantum hydrodynamic equations and in the spectrum of waves in magnetized electron-positron plasmas. We consider the propagation of waves parallel and perpendicular to an external magnetic field. We also consider the oblique propagation of longitudinal waves. We derive the set of quantum kinetic equations for electron-positron plasmas with the Darwin and annihilation interactions. We apply the kinetic theory to the linear wave behavior in absence of external fields. We calculate the contribution of the Darwin and annihilation interactions in the Landau damping of the Langmuir waves. We should mention that the annihilation interaction does not change number of particles in the system. It does not related to annihilation itself, but it exists as a result of interaction of an electron-positron pair via conversion of the pair into virtual photon. A pair of the non-linear Schrodinger equations for the electron-positron plasmas including the Darwin and annihilation interactions is derived. Existence of the conserving helicity in electron-positron quantum plasmas of spinning particles with the Darwin and annihilation interactions is demonstrated. We show that the annihilation interaction plays an important role in the quantum electron-positron plasmas giving the contribution of the same magnitude as the spin-spin interaction.
Viscous fluid injection into a confined channel
Authors: Zheng Zhong , Rongy Laurence , Stone Howard A.
Published: June 2015

We analyze the injection of a viscous fluid into a two-dimensional horizontal confined channel initially filled with another viscous fluid of different density and viscosity. We study the flow using the lubrication approximation and assume that the mixing between the fluids and their interfacial tension are negligible. When the injection rate is maintained constant, the evolution of the fluid-fluid interface can be described by a nonlinear advection-diffusion equation dependent only on the viscosity ratio between the two fluids. In the early time period, the advection-diffusion equation reduces to a well-known nonlinear diffusion equation, and a self-similar solution is obtained. In the late time period, the advection-diffusion equation is approximated by a nonlinear hyperbolic equation, and a compound wave solution is constructed to describe the time evolution of the fluid-fluid interface. Numerical solutions of the full equation show good agreement with the analytical solutions in both the early and late time periods. Finally, a regime diagram is obtained to summarize the flow behaviours with regard to two dimensionless groups: the viscosity ratio of the two fluids and the dimensionless time; three different dynamical behaviours are identified in the regime diagram: a nonlinear diffusion regime, a hyperbolic regime, and a transition regime. This problem is analogous to the corresponding injection flow problem into a confined porous medium.
Photoinduced reactions of both 2-formyl-2H-azirine and isoxazole: A theoretical study based on electronic structure calculations and nonadiabatic dynamics simulations
Authors: Cao Jun
Published: June 2015

In the present work, the combined electronic structure calculations and dynamics simulations have been performed to explore photocleavages of 2-formyl-2H-azirine and isoxazole in the gas phase and the subsequent rearrangement reactions. The carbonyl n → π* transition induces a cleavage of the C—N single bond of 2-formyl-2H-azirine to yield β-formylvinylnitrene in open-shell singlet state. However, the n → π* excitation of the imine chromophore results in a cleavage of the C—C single bond, producing a nitrile ylide intermediate through an internal conversion to the ground state. β-formylvinylnitrene and nitrile ylide with the carbonyl group are easily transformed into 2-formyl-2H-azirine and oxazole, respectively. The N—O bond cleavages on both S1(1ππ*) and S2(1nNπ*) of isoxazole are ultrafast processes, and they give products of 2-formyl-2H-azirine, 3-formylketenimine, HCN + CHCHO, and HCO + CHCHN. Both 2H-azirines and ketenimines were suggested to be formed from the triplet vinylnitrenes by intersystem crossing in the previous studies. However, our calculations show that the singlet β-formylvinylnitrene is responsible for the formation of 2-formyl-2H-azirine and 3-formylketenimine, and the singlet vinylnitrenes can play a key role in the photoinduced reactions of both 2H-azirines and isoxazoles.
Statistics of time delay and scattering correlation functions in chaotic systems. II. Semiclassical approximation
Authors: Novaes Marcel
Published: June 2015

We consider S-matrix correlation functions for a chaotic cavity having M open channels, in the absence of time-reversal invariance. Relying on a semiclassical approximation, we compute the average over E of the quantities Tr[S†(E − ϵ) S(E + ϵ)]n, for general positive integer n. Our result is an infinite series in ϵ, whose coefficients are rational functions of M. From this, we extract moments of the time delay matrix Q = − iħS†dS/dE and check that the first 8 of them agree with the random matrix theory prediction from our previous paper [M. Novaes, J. Math. Phys. 56, 062110 (2015)].
Biomagnetic fluid flow in an aneurysm using ferrohydrodynamics principles
Authors: Tzirtzilakis E. E.
Published: June 2015

In this study, the fundamental problem of biomagnetic fluid flow in an aneurysmal geometry under the influence of a steady localized magnetic field is numerically investigated. The mathematical model used to formulate the problem is consistent with the principles of ferrohydrodynamics. Blood is considered to be an electrically non-conducting, homogeneous, non-isothermal Newtonian magnetic fluid. For the numerical solution of the problem, which is described by a coupled, non-linear system of Partial Differential Equations (PDEs), with appropriate boundary conditions, the stream function-vorticity formulation is adopted. The solution is obtained by applying an efficient pseudotransient numerical methodology using finite differences. This methodology is based on the application of a semi-implicit numerical technique, transformations, stretching of the grid, and construction of the boundary conditions for the vorticity. The results regarding the velocity and temperature field, skin friction, and rate of heat transfer indicate that the presence of a magnetic field considerably influences the flow field, particularly in the region of the aneurysm.
Explosive crystallization in thin amorphous layers on heat conducting substrates
Authors: Buchner Christoph , Schneider Wilhelm
Published: June 2015

A model for explosive crystallization in a thin amorphous layer on a heat conducting substrate is presented. For the thin layer, the energy equation is used in a one-dimensional approximation. Heat conduction into the substrate and thermal contact resistance at the interface between layer and substrate are taken into account. Four rate equations are used to describe the kinetics of the homogeneous amorphous-crystalline transition. The whole process is examined as a plane wave of invariant shape in a moving frame of reference. Heat conduction in the substrate is described by introducing a continuous distribution of moving heat sources at the interface. This gives an integral representation for the temperature in the substrate in terms of the unknown source distribution. The integral term implies that there is a non-local influence of the temperature distribution in the layer on the heat loss. A coupled system of an integro-differential equation and four ordinary differential equations is obtained and solved numerically. The propagation velocity of the wave is obtained as an eigenvalue of the system of equations. Varying a non-dimensional heat loss parameter, a critical value is found beyond which no crystallization wave of invariant shape is possible. This can also be interpreted as a certain minimum layer thickness. Temperature and crystallinity distributions are shown for some interesting configurations. Predictions of crystallization-wave velocities and minimum layer thicknesses are compared with experimental values for explosive crystallization in germanium.
Synergistic stabilization of metastable Fe23B6 and γ-Fe in undercooled Fe83B17
Authors: Quirinale D. G. , Rustan G. E. , Kreyssig A. , Goldman A. I.
Published: June 2015

Previous investigations of undercooled liquid Fe83B17 near the eutectic composition have found that metastable crystalline phases, such as Fe23B6, can be formed and persist down to ambient temperature even for rather modest cooling rates. Using time-resolved high-energy x-ray diffraction on electrostatically levitated samples of Fe83B17, we demonstrate that the Fe23B6 metastable phase and fcc γ-Fe grow coherently from the undercooled Fe83B17 liquid and effectively suppress the formation of the equilibrium Fe2B + bcc α-Fe phases. The stabilization of γ-Fe offers another opportunity for experimental investigations of magnetism in metastable fcc iron.
Resonant indirect exchange via spatially separated two-dimensional channel
Authors: Rozhansky I. V. , Krainov I. V. , Averkiev N. S. , Aronzon B. A. , Davydov A. B. , Kugel K. I. , Tripathi V. , Lähderanta E.
Published: June 2015

We apply the resonant indirect exchange interaction theory to explain the ferromagnetic properties of the hybrid heterostructure consisting of a InGaAs-based quantum well (QW) sandwiched between GaAs barriers with spatially separated Mn δ-layer. The experimentally obtained dependence of the Curie temperature on the QW depth exhibits a peak related to the region of resonant indirect exchange. We suggest the theoretical explanation and a fit to this dependence as a result of the two contributions to ferromagnetism—the intralayer contribution and the resonant exchange contribution provided by the QW.
Angular tuning of the magnetic birefringence in rippled cobalt films
Authors: Arranz Miguel A. , Colino José M.
Published: June 2015

We report the measurement of magnetically induced birefringence in rippled Co films. For this purpose, the magneto-optical properties of ion beam eroded ferromagnetic films were studied using Kerr magnetometry and magnetic birefringence in the transmitted light intensity. Upon sufficient ion sculpting, these ripple surface nanostructures developed a defined uniaxial anisotropy in the in-plane magnetization, finely tuning the magnetic birefringence effect. We have studied its dependence on the relative orientation between the ripple direction and the magnetic field, and found this effect to be dramatically correlated with the capability to neatly distinguish the mechanisms for the in-plane magnetization reversal, i.e., rotation and nucleation. This double refraction corresponds univocally to the two magnetization axes, parallel and perpendicular to the ripples direction. We have also observed that tuned birefringence in stack assemblies of rippled Co films, which enables us to technically manipulate the number and direction of refraction axes.
Rate-limited plastic deformation in nanocrystalline Ni
Authors: Cao Lei , Koslowski Marisol
Published: June 2015

Numerical simulations at nanometer scales have identified several mechanisms of plastic deformation. However, high strain rate regimes are required to resolve nanometer length scales. Extrapolating these numerical predictions at high strain rates to experimental conditions remains an unresolved challenge. Phase-field dislocation dynamics (PFDD) simulations are conducted to study the strain rate sensitivity of plastic deformation in nanocrystalline metals. The PFDD simulations involve the collective behavior of partial and extended full dislocations at strain rates ranging from 1 × 106 s−1 to 1 × 109 s−1 in Ni samples with an average grain size of 15 nm. Significant differences are found in the activation and glide of dislocations over this range of strain rates. At high strain rates, there are a large number of partial dislocations that begin to glide at grain boundaries across the entire sample. On the other hand, glide events are limited to a few grain boundaries at lower strain rates. Even though, the number of events is larger at high strain rates, mainly leading partial dislocations are active, and therefore, the amount of plastic deformation is smaller. This leads to an effective delay in plastic strain at high strain rates that explain the stress upturn observed at high strain rates when plastic deformation is carried out by partial dislocations. When extended full dislocations are present at lower strain rates, the yield stress is reduced by around 40%.
Braids as a representation space of SU(5)
Authors: Cartin Daniel
Published: June 2015

The standard model of particle physics provides very accurate predictions of phenomena occurring at the sub-atomic level, but the reason for the choice of symmetry group and the large number of particles considered elementary is still unknown. Along the lines of previous preon models positing a substructure to explain these aspects, Bilson-Thompson showed how the first family of elementary particles is realized as the crossings of braids made of three strands, with charges resulting from twists of those strands with certain conditions; in this topological model, there are only two distinct neutrino states. Modeling the particles as braids implies these braids must be the representation space of a Lie algebra, giving the symmetries of the standard model. In this paper, this representation is made explicit, obtaining the raising operators associated with the Lie algebra of SU(5), one of the earliest grand unified theories. Because the braids form a group, the action of these operators are braids themselves, leading to their identification as gauge bosons. Possible choices for the other two families are also given. Although this realization of particles as braids is lacking a dynamical framework, it is very suggestive, especially when considered as a natural method of adding matter to loop quantum gravity.
Effect of dust particle polarization on scattering processes in complex plasmas
Authors: Kodanova S. K. , Ramazanov T. S. , Bastykova N. Kh. , Moldabekov Zh. A.
Published: June 2015

Screened interaction potentials in dusty plasmas taking into account the polarization of dust particles have been obtained. On the basis of screened potentials scattering processes for ion-dust particle and dust particle-dust particle pairs have been studied. In particular, the scattering cross section is considered. The scattering processes for which the dust grain polarization is unimportant have been found. The effect of zero angle dust particle-dust particle scattering is predicted.
Multilayer ceramic capacitors based on relaxor BaTiO3-Bi(Zn1/2Ti1/2)O3 for temperature stable and high energy density capacitor applications
Authors: Kumar Nitish , Ionin Aleksey , Ansell Troy , Kwon Seongtae , Hackenberger Wesley , Cann David
Published: June 2015

The need for miniaturization without compromising cost and performance continues to motivate research in advanced capacitor devices. In this report, multilayer ceramic capacitors based on relaxor BaTiO3-Bi(Zn1/2Ti1/2)O3 (BT-BZT) were fabricated and characterized. In bulk ceramic embodiments, BT-BZT has been shown to exhibit relative permittivities greater than 1000, high resistivities (ρ > 1 GΩ-cm at 300 °C), and negligible saturation up to fields as high as 150 kV/cm. Multilayer capacitor embodiments were fabricated and found to exhibit similar dielectric and resistivity properties. The energy density for the multilayer ceramics reached values of ∼2.8 J/cm3 at room temperature at an applied electric field of ∼330 kV/cm. This represents a significant improvement compared to commercially available multilayer capacitors. The dielectric properties were also found to be stable over a wide range of temperatures with a temperature coefficient of approximately −2000 ppm/K measured from 50 to 350 °C, an important criteria for high temperature applications. Finally, the compatibility of inexpensive Ag-Pd electrodes with these ceramics was also demonstrated, which can have implications on minimizing the device cost.
Phonon bottleneck in GaAs/AlxGa1−xAs quantum dots
Authors: Chang Y. C. , Robson A. J. , Harrison S. , Zhuang Q. D. , Hayne M.
Published: June 2015

We report low-temperature photoluminescence measurements on highly-uniform GaAs/AlxGa1−xAs quantum dots grown by droplet epitaxy. Recombination between confined electrons and holes bound to carbon acceptors in the dots allow us to determine the energies of the confined states in the system, as confirmed by effective mass calculations. The presence of acceptor-bound holes in the quantum dots gives rise to a striking observation of the phonon-bottleneck effect.
Are superhalogens without halogen ligand capable of transcending traditional halogen-based superhalogens? Ab initio case study of binuclear anions based on pseudohalogen ligand
Authors: Li Jin-Feng , Sun Yin-Yin , Bai Hongcun , Li Miao-Miao , Li Jian-Li , Yin Bing
Published: June 2015

The superhalogen properties of polynuclear structures without halogen ligand are theoretically explored here for several [M2(CN)5]−1 (M =  Ca, Be) clusters. At CCSD(T) level, these clusters have been confirmed to be superhalogens due to their high vertical electron detachment energies (VDE). The largest one is 9.70 eV for [Ca2(CN)5]−1 which is even higher than those of corresponding traditional structures based on fluorine or chlorine ligands. Therefore the superhalogens stronger than the traditional halogen-based structures could be realized by ligands other than halogen atoms. Compared with CCSD(T), outer valence Green’s function (OVGF) method either overestimates or underestimates the VDEs for different structures while MP2 results are generally consistent in the aspect of relative values. The extra electrons of the highest VDE anions here aggregate on the bridging CN units with non-negligible distribution occurring on other CN units too. These two features lower both the potential and kinetic energies of the extra electron respectively and thus lead to high VDE. Besides superhalogen properties, the structures, relative stabilities and thermodynamic stabilities with respect to the detachment of cyanide ligand were also investigated. The sum of these results identifies the potential of polynuclear structures with pseudohalogen ligand as suitable candidates with enhanced superhalogens properties.
Natural patterning of templates on GaAs by formation of cracks
Authors: Song Yuxin , Xu Hao , Li Yaoyao , Sadeghi Mahdad , Wang Shumin
Published: June 2015

Substrate pre-patterning is an effective way to overcome large lattice mismatch and suppress threading defects in the growth of heterostructures. In this work, a new concept was proposed to form natural patterns on commercial substrates monolithically by the formation of surface cracks. Tensile strain was intentionally brought in with a GaAs or GaNAs layer above an InGaAs layer on GaAs substrates. Surface crack patterns successfully formed during the strain relaxation. The strain in a 1 μm buffer layer atop the pattern was found effectively relaxed. Detailed residual strain distribution was simulated by the finite element method.
Adsorbate-induced quantum Hall system probed by scanning tunneling spectroscopy combined with transport measurements
Authors: Masutomi Ryuichi , Okamoto Tohru
Published: June 2015

An adsorbate-induced quantum Hall system at the cleaved InSb surfaces is investigated in magnetic fields up to 14 T using low-temperature scanning tunneling microscopy and spectroscopy combined with transport measurements. We show that an enhanced Zeeman splitting in the Shubnikov-de Haas oscillations is explained by an exchange enhancement of spin splitting and potential disorder, both of which are obtained from the spatially averaged density of states (DOS). Moreover, the Altshuler–Aronov correlation gap is observed in the spatially averaged DOS at 0 T.
Lactoferrin gene variants, their expression in the udder and mastitis susceptibility in dairy cattle
Authors: Pawlik Adrianna , Sender Grażyna , Sobczyńska Magdalena , Korwin-Kossakowska Agnieszka , Lassa Henryka , Oprządek Jolanta
Published: June 2015

Lactoferrin gene (LF) is regarded as one of the potential markers of mastitis susceptibility/resistance in dairy cattle. The study’s aim was therefore, to investigate the feasibility of two single nucleotide polymorphisms (SNP), placed in the 5′-flanking region and 3′-untranslated region of the LF gene, to serve as mastitis markers. The associations between these SNP and the expression of LF, both on mRNA and protein level, were estimated in the milk of Polish Holstein-Friesian cows. The relationships between polymorphisms and cows’ estimated breeding values (EBV) for somatic cell count were also calculated. It was shown that both polymorphisms have a significant impact on lactoferrin content in milk, and that LF+32 SNP is associated with the cow’s EBV for somatic cell count. No association between SNP chosen for the study and lactoferrin mRNA abundance in milk somatic cells was observed. We propose LF+32 SNP for a molecular marker of mastitis resistance in dairy cows.
Effect of fresh pasture forage quality, feeding level and supplementation on methane emissions from growing beef cattle
Authors: Jonker Arjan , Muetzel Stefan , Molano German , Pacheco David
Published: June 2015

The objectives of this study were to determine the effect of fresh pasture forage quality (vegetative and mature pasture in different seasons), feeding level and supplementation with maize silage or palm kernel expeller on methane (CH4) production (g/day) and yield (g/kg dry matter intake; DMI) in growing beef cattle. The null hypothesis was that pasture quality, DMI level and supplementation have no effect on the CH4 yield (g/kg DM) in beef cattle. Four experiments were conducted and in three experiments (Exp. 1–3) freshly cut vegetative or mature pasture was fed to 14 growing beef animals in two consecutive periods, respectively, at intake levels of 1.5, 1.8 and 1.1 × maintenance metabolisable energy requirements (MEm) in Exp. 1–3, respectively. For Exp. 3, 100% maize silage was fed in a third consecutive period to the same cattle used in Periods 1 and 2. In Exp. 4, 4 animals were fed one of three treatments at 1.6 × MEm of 100% fresh pasture, fresh pasture supplemented with 35% DM maize silage or fresh pasture supplemented with 35% DM palm kernel expeller. After acclimatisation to respective diets, DMI and CH4 were measured for 12 animals in individual open circuit respiration chambers for two consecutive days in each experiment. Methane yield (g/kg DMI) was similar when animals were fed vegetative or mature pasture in Exp. 1 (20.0) and 2 (25.8), whereas in Exp. 3 feeding vegetative pasture resulted in a higher CH4 yield (25.7; P < 0.05) compared with feeding mature pasture (23.3), with feeding 100% maize silage intermediate (23.8). Methane yield of cattle fed pasture supplemented with maize silage in Exp. 4 was 10% higher (P < 0.05) compared with cattle fed mature pasture only or supplemented with palm kernel expeller (25.9, 23.3, 23.4 g/kg DMI, respectively). The regression between DMI and CH4 yield was similar for vegetative and mature pasture and pasture composition could explain up to 26% of variation in CH4 yield (P < 0.05). The CH4 yield in cattle fed 100% pasture (Exp. 1–3) was not affected by DMI and averaged 24.1 ± 2.78 g/kg DMI. In conclusion, fresh pasture forage quality, feeding level and supplementation had only minor, but some significant, effects on CH4 yield in beef cattle.
Climate-driven shifts in species' distributions may exacerbate the impacts of storm disturbances on North-east Atlantic kelp forests
Authors: Smale Dan A. , Vance Thomas
Published: June 2015

Physical disturbance through wave action is a major determinant of kelp forest structure. The North-east Atlantic storm season of 2013–14 was unusually severe; the south coast of the UK was subjected to 6 of the 12 most intense storms recorded in the past 5 years. Inshore significant wave heights and periods exceeded 7m and 13s with two storms classified as ‘1-in-30 year’ events. We examined the impacts of the storm season on kelp canopies at three study sites. Monospecific canopies comprising Laminaria hyperborea were unaffected by storm disturbance. However, at one study site a mixed canopy comprising Laminaria ochroleuca, Saccharina latissima and L. hyperborea was significantly altered by the storms, due to decreased abundances of the former two species. Quantification of freshly severed stipes suggested that the ‘warm water’ kelp L. ochroleuca was more susceptible to storm damage than L. hyperborea. Overall, kelp canopies were highly resistant to storm disturbance because of the low vulnerability of L. hyperborea to intense wave action. However, if climate-driven shifts in kelp species distributions result in more mixed canopies, as predicted, then resistance to storm disturbance may be eroded.
Triggering larval settlement behaviour and metamorphosis of the burrowing ghost shrimp, Lepidophthalmus siriboia (Callianassidae): do cues matter?
Authors: Campos Kácia Letícia de Noronha , Abrunhosa Fernando Araújo , Simith Darlan de Jesus de Brito
Published: June 2015

Larval settlement and metamorphosis of many estuarine decapod crustaceans are triggered by environmental cues and chemical substances produced by the conspecific population. Here, we examined the influence of substrata and conspecific cues on the stimulation of the megalopal stage of the burrowing ghost shrimp (Lepidophthalmus siriboia) in the following five treatments: (1) adult-conditioned seawater (ACSW), (2) filtered seawater (FSW) + sand, (3) FSW + muddy sand (MS), (4) ACSW + MS and (5) FSW without cues (control). All megalopae settled and exhibited burrowing behaviour in the treatments containing substratum. The percentage of metamorphosis to juvenile was high (≥96%) in all treatments. Megalopae developed significantly faster in the control (5.7days, ±0.9s.d.) than in the remaining treatments (6.8–7.3 days). These findings demonstrated that settlement of L. siriboia megalopae is strongly induced by substrata, whereas their metamorphosis occurs irrespective of the presence or type of exogenous cues associated with estuarine habitat and conspecific adults. This suggests certain flexibility concerning the ontogenetic stage at which recruitment to the benthos occurs. The independence of metamorphic inducers should be important for colonisation of new estuarine areas as well as for recovery and maintenance of viable populations in disturbed habitats where callianassid ghost shrimps are heavily exploited.
An empirical wildfire risk analysis: the probability of a fire spreading to the urban interface in Sydney, Australia
Authors: Price Owen , Borah Rittick , Bradstock Ross , Penman Trent
Published: June 2015

We present a method and case study to predict and map the likelihood of wildfires spreading to the urban interface through statistical analysis of past fire patterns using 15 000 lines from 677 fires with known ignition points and date and random potential end points on the urban interface of Sydney, Australia. A binomial regression approach was used to model whether the fire burnt to the end point of the lines as a function of measures of distance, fuel, weather and barriers to spread. Fire weather had the strongest influence on burning likelihood followed by the percentage of the line that was forested, distance and time since last fire. Fuel treatments would substantially reduce risk from fires starting 1–4 km away from the interface. The model captured 90% of variation in burning with 98% predictive accuracy on test data and was not affected by spatial autocorrelation. We apply the method to map fire risk in Sydney and discuss how the method could be expanded to estimate total risk (from ignition to impact on assets). The method has considerable promise for predicting risk, especially as a complement to simulation methods.
Developed turbulence and nonlinear amplification of magnetic fields in laboratory and astrophysical plasmas
Authors: Meinecke Jena , Tzeferacos Petros , Bell Anthony , Bingham Robert , Clarke Robert , Churazov Eugene , Crowston Robert , Doyle Hugo , Drake R. Paul , Heathcote Robert , Koenig Michel , Kuramitsu Yasuhiro , Kuranz Carolyn , Lee Dongwook , MacDonald Michael , Murphy Christopher , Notley Margaret , Park Hye-Sook , Pelka Alexander , Ravasio Alessandra , Reville Brian , Sakawa Youichi , Wan Willow , Woolsey Nigel , Yurchak Roman , Miniati Francesco , Schekochihin Alexander , Lamb Don , Gregori Gianluca
Published: June 2015

Significance

Magnetic fields exist throughout the universe. Their energy density is comparable to the energy density of the fluid motions of the plasma in which they are embedded, making magnetic fields essential players in the dynamics of the luminous matter in the universe. The origin and the amplification of these magnetic fields to their observed strengths are far from being understood. The standard model for the origin of these galactic and intergalactic magnetic fields is through the amplification of seed fields via turbulent processes to the level consistent with current observations. For this process to be effective, the amplification needs to reach a strongly nonlinear phase. Experimental evidence of the initial nonlinear amplification of magnetic fields is presented in this paper.
Self-reproducing catalyst drives repeated phospholipid synthesis and membrane growth
Authors: Hardy Michael D. , Yang Jun , Selimkhanov Jangir , Cole Christian M. , Tsimring Lev S. , Devaraj Neal K.
Published: June 2015

Significance

We report on the design and synthesis of an artificial cell membrane that sustains continual growth. Lipid membranes are ubiquitous in all domains of life. Numerous studies have exploited the ability of lipids to self-assemble into bilayer vesicles with properties reminiscent of cellular membranes, but previous work has yet to mimic nature’s ability to support persistent phospholipid membrane formation. In this work, we have developed an artificial cell membrane that continually synthesizes all of the components needed to form additional catalytic membranes. These results demonstrate that complex lipid membranes capable of indefinite self-synthesis can emerge when supplied with simpler chemical building blocks.
Genetic architecture of natural variation in
Drosophila melanogaster
aggressive behavior
Authors: Shorter John , Couch Charlene , Huang Wen , Carbone Mary Anna , Peiffer Jason , Anholt Robert R. H. , Mackay Trudy F. C.
Published: June 2015

Significance

Aggressive behavior is evolutionarily conserved and genetically complex, but the genetic basis of natural variation in aggression is largely unknown. We performed genome-wide association analyses using the inbred, sequenced lines of the
Drosophila
Genetic Reference Panel (DGRP) and an advanced intercross population derived from the most and least aggressive DGRP lines. These analyses identified largely nonoverlapping genes that mapped onto a genetic interaction network inferred from an analysis of pairwise epistasis in the DGRP. We functionally validated candidate genes and genetic interactions. Epistasis for aggressive behavior causes cryptic genetic variation in the DGRP that is revealed by changing allele frequencies. This observation may apply to other fitness traits and species, with implications for evolution, applied breeding, and human genetics.
Neonyms for a crisis
Authors: Mateo José
Published: June 2015

The current economic and financial crisis apart from impoverishing many countries has paradoxically enriched language by coining a multitude of new terms to explain and define the new situation. However, due to different cognitive, terminological and socio-pragmatic constraints, many of these financial neonyms, originally created in English, have been poorly transferred into Spanish or left untranslated thus losing most of their original distinctive and explanatory purpose. Many Spanish financial experts tend to use the English forms or render literal and often meaningless translations. This paper explores the structure of financial crisis neonyms in the light of their terminological composition and professional and social practice and focusses on the problems created by their translation into Spanish mainly as a result of cognitive-inferential, semantic-terminological and pragmatic-communicative mismatches.
Corpus stylistics of drama in drama translation studies
Authors: Xiaofei Ren , Lanlan Li , Chuanrui Zhang , Jing Lu , Feng Liu
Published: June 2015

Drama translation studies used to be the most neglected area in translation studies due to its prescriptive approaches and reductionist illusion of polarization of performability and readability. Corpus stylistics of drama, with the aid of computer technology as well as the understanding of the true nature of drama as the dialectical combination of both literary and theatrical characteristics, appears to be a remarkable theoretical framework and methodology for drama translation studies. The study of (im)politeness in Death of a Salesman and its two Chinese versions is undertaken as a case study. ICTCLAS and Concordance 3.0 were used to calculate the high frequent expressions concerning (im)politeness in both the original text and the Chinese versions, followed by the analysis of their stylistic function. It is found that modal particles and slang expressions in Chinese are useful to reconstruct the characterization, plot as well as performability of the translated drama. In conclusion, corpus stylistics of drama is of high feasibility in drama translation studies.
El estilo del traductor en el tratamiento de las onomatopeyas del chino al español
Authors: Casas-Tost Helena
Published: June 2015

Onomatopoeia are words with peculiar phonological features and expressive capacity which distinguish them from other types of words. These traits together with other elements related to their use in each language often pose a challenge for translators of specific language combinations. This article analyses how Chinese onomatopoeia are translated into Spanish, and it is based on a case study of the Spanish version of the Chinese novel Huozhe (活着) (To live). This piece of creative writing has been chosen because the original text contains many onomatopoeia and because the target text can be regarded as a fine example from a translation point of view. The article begins with a brief overview of the main features of these words and their role in literary texts, as well as the general results of the analysis of a corpus of seven contemporary Chinese novels and their translations into Spanish. Subsequently, the study explores the translation of onomatopoeia in the selected work of fiction in order to identify the mechanisms and translation techniques the translator has adopted and the results in the Spanish target text.
Translation and linguistic recycling in Arabic
Authors: Izwaini Sattar
Published: June 2015

Linguistic expressions in every language have established patterns with meanings that can be inferred by linguistic conventions. Languages have their own norms and expressing systems that make transferred linguistic formulas seem odd. Any deviation from the established patterns can be referred to as interference. Interference in translation is the transfer of some linguistic aspect of the source text (ST) into the target text (TT). The term includes any kind of influence that is exerted by the linguistic properties of the ST on the linguistic properties of the TT. Lexical items and syntactic structures of the source language are copied into the TT, resulting in the phenomenon called ‘translationese’. As a result of interference, translation has introduced a plethora of words, expressions, and constructions into Arabic, resulting in a change in modern Arabic style. One phenomenon that Arabic has witnessed in modern times is linguistic recycle. This term refers to the re-utilization of translated expressions and syntactic structures in Arabic in its intra-linguistic operation (opposed to the inter-linguistic event of translation). The language community has been using these translation-introduced formulations although they do not conform to the canonical patterns of Arabic. Being unaware of this fact, speakers of Arabic use the translation-introduced expressions and constructions instead of the native ones although they have at their disposal a variety of formulations to express the same ideas. Linguistic recycle can be categorized into the three areas of lexis, syntax, and culture. Using a contrastive approach, the paper investigates the areas of lexis and syntax, demonstrating the pervasiveness of this phenomenon and its impact on Arabic. Corpora of Arabic have been used to detect and verify occurrences of expressions and structures.
Pheromone-encoding mRNA is transported to the yeast mating projection by specific RNP granules
Authors: Aronov Stella , Dover-Biterman Saray , Suss-Toby Edith , Shmoish Michael , Duek Lea , Choder Mordechai
Published: June 2015

Association of messenger RNAs with large complexes such as processing bodies (PBs) plays a pivotal role in regulating their translation and decay. Little is known about other possible functions of these assemblies. Exposure of haploid yeast cells, carrying mating type “a,” to “α pheromone” stimulates polarized growth resulting in a “shmoo” projection; it also induces synthesis of “a pheromone,” encoded by MFA2. In this paper, we show that, in response to α pheromone, MFA2 mRNA is assembled with two types of granules; both contain some canonical PB proteins, yet they differ in size, localization, motility, and sensitivity to cycloheximide. Remarkably, one type is involved in mRNA transport to the tip of the shmoo, whereas the other—in local translation in the shmoo. Normal assembly of these granules is critical for their movement, localization, and for mating. Thus, MFA2 mRNAs are transported to the shmoo tip, in complex with PB-like particles, where they are locally translated.