bluuebunny/crossref_metadata_2025 huggingface dataset:
Truth versus information in logic programming
Authors: NAISH LEE , SØNDERGAARD HARALD
Published: June 2013

The semantics of logic programs was originally described in terms of two-valued logic. Soon, however, it was realised that three-valued logic had some natural advantages, as it provides distinct values not only for truth and falsehood but also for “undefined”. The three-valued semantics proposed by Fitting (Fitting, M. 1985. A Kripke–Kleene semantics for logic programs.Journal of Logic Programming 2, 4, 295–312) and Kunen (Kunen, K. 1987. Negation in logic programming.Journal of Logic Programming 4, 4, 289–308) are closely related to what is computed by a logic program, the third truth value being associated with non-termination. A different three-valued semantics, proposed by Naish, shared much with those of Fitting and Kunen but incorporated allowances for programmer intent, the third truth value being associated with underspecification. Naish used an (apparently) novel “arrow” operator to relate the intended meaning of left and right sides of predicate definitions. In this paper we suggest that the additional truth values of Fitting/Kunen and Naish are best viewed as duals. We use Belnap's four-valued logic (Belnap, N. D. 1977. A useful four-valued logic. InModern Uses of Multiple-Valued Logic, J. M. Dunn and G. Epstein, Eds. D. Reidel, Dordrecht, Netherlands, 8–37), also used elsewhere by Fitting, to unify the two three-valued approaches. The truth values are arranged in a bilattice, which supports the classical ordering on truth values as well as the “information ordering”. We note that the “arrow” operator of Naish (and our four-valued extension) is essentially the information ordering, whereas the classical arrow denotes the truth ordering. This allows us to shed new light on many aspects of logic programming, including program analysis, type and mode systems, declarative debugging and the relationships between specifications and programs, and successive execution states of a program.
A proof of concept of a non-resonant near-field microwave microscope based on a high impedance reflectometer
Authors: Glay David , El Fellahi Adelhatif , Lasri Tuami
Published: June 2013

In this paper, we present a non-resonant high impedance reflectometer with a reference impedance close to one of the tip probe of a near-field microwave microscope. We show that for an apex of the tip probe of 100 µm there is an optimum reference impedance close to 1 kΩ. To validate this approach a microwave circuit that makes use of lumped elements has been fabricated. A proof of concept is also explored for capacitance measurements between the tip probe and a metal plate.
Symptomatic Adjacent Segment Pathology after Posterior Lumbar Interbody Fusion for Adult Low-Grade Isthmic Spondylolisthesis
Authors: Sakaura Hironobu , Yamashita Tomoya , Miwa Toshitada , Ohzono Kenji , Ohwada Tetsuo
Published: June 2013

The incidence of symptomatic adjacent segment pathology (ASP) after fusion surgery for adult low-grade isthmic spondylolisthesis (IS) has been reported to be relatively low compared with other lumbar disease entities. However, there has been no study of symptomatic ASP incidence using posterior lumbar interbody fusion (PLIF) with pedicle screw instrumentation. We investigated the incidence of symptomatic ASP after PLIF with pedicle screw instrumentation for adult low-grade IS and identified significant risk factors for symptomatic ASP. We retrospectively studied records of 40 consecutive patients who underwent PLIF with pedicle screw instrumentation at the Department of Orthopaedic Surgery, Kansai Rosai Hospital, Amagasaki, Japan. The patients were followed for ≥ 4 years. Patients’ medical records were retrospectively examined for evidence of symptomatic ASP. Age at time of surgery, sex, fusion level, whole lumbar lordosis, segmental lordosis, preexisting laminar inclination angle, and facet tropism at the cranial fusion segment were analyzed to identify risk factors for symptomatic ASP. Four patients (ASP group) developed symptomatic ASP at the cranial segment adjacent to the fusion. There were no significant differences in age, sex, fusion level, lumbar lordosis, segmental lordosis, or facet tropism at the cranial segment adjacent to the fusion between the ASP and the non-ASP groups. In contrast, laminar inclination angle at the cranial vertebra adjacent to the fusion was significantly higher in the ASP group than in the non-ASP group. Four patients (10%) developed symptomatic ASP after PLIF with transpedicular fixation for adult low-grade IS. Preexisting laminar horizontalization at the cranial vertebra adjacent to the fusion was a significant risk factor for symptomatic ASP.
Spin-wave interference in microscopic permalloy tubes
Authors: Balhorn Felix , Nagrodzki Lukas , Mendach Stefan
Published: June 2013

We present permalloy coated needles which act as spin-wave resonators. The permalloy coated needles were investigated using microwave absorption spectroscopy. Thereby, we found up to three resonant modes which correspond to constructively interfering azimuthal spin waves. The resonant modes are well reproduced in calculations based on an analytical model for the spin-wave dispersion employing periodic boundary conditions. The dependence of the resonance frequencies on the needles' radii and the external magnetic field is demonstrated experimentally.
A sphere-cut-splice crossover for the evolution of cluster structures
Authors: Chen Zhanghui , Jiang Xiangwei , Li Jingbo , Li Shushen
Published: June 2013

A new crossover operator is proposed to evolve the structures of the atomic clusters. It uses a sphere rather than a plane to cut and splice the parent structures. The child cluster is constructed by the atoms of one parent which lie inside the sphere, and the atoms of the other parent which lie outside the sphere. It can reliably produce reasonable offspring and preserve the good schemata in parent structures, avoiding the drawbacks of the classical plane-cut-splice crossover in the global searching ability and the local optimization speed. Results of Lennard-Jones clusters (30 ⩽ N ⩽ 500) show that at the same settings the genetic algorithm with the sphere-cut-splice crossover exhibits better performance than the one with the plane-cut-splice crossover. The average number of local minimizations needed to find the global minima and the average number of energy evaluation of each local minimization in the sphere scheme is 0.8075 and 0.8386 of that in the plane scheme, respectively. The mean speed-up ratio for the entire testing clusters reaches 1.8207. Moreover, the sphere scheme is particularly suitable for large clusters and the mean speed-up ratio reaches 2.3520 for the clusters with 110 ⩽ N ⩽ 500. The comparison with other successful methods in previous studies also demonstrates its good performance. Finally, a further analysis is presented on the statistical features of the cutting sphere and a modified strategy that reduces the probability of using tiny and large spheres exhibits better global search.
Energy transfer between the shape and volume modes of a nonspherical gas bubble
Authors: Harkin Anthony A. , Kaper Tasso J. , Nadim Ali
Published: June 2013

A model of a nonspherical gas bubble is developed in which the Rayleigh-Plesset equation is augmented with second order terms that back-couple the volume mode to a single shape mode. These additional terms in the Rayleigh-Plesset equation permit oscillation energy to be transferred back and forth between the shape and volume modes. The parametric stability of the shape mode is analyzed for a driven bubble, and it is seen that the bidirectional coupling yields an enhanced, albeit minor, stabilizing effect on the shape mode when compared with a model where the shape-volume coupling is unidirectional. It is also demonstrated how a pure shape distortion can excite significant volume pulsations when the volume mode is in 2:1 internal resonance with the shape mode.
Power functional theory for Brownian dynamics
Authors: Schmidt Matthias , Brader Joseph M.
Published: June 2013

Classical density functional theory (DFT) provides an exact variational framework for determining the equilibrium properties of inhomogeneous fluids. We report a generalization of DFT to treat the non-equilibrium dynamics of classical many-body systems subject to Brownian dynamics. Our approach is based upon a dynamical functional consisting of reversible free energy changes and irreversible power dissipation. Minimization of this “free power” functional with respect to the microscopic one-body current yields a closed equation of motion. In the equilibrium limit the theory recovers the standard variational principle of DFT. The adiabatic dynamical density functional theory is obtained when approximating the power dissipation functional by that of an ideal gas. Approximations to the excess (over ideal) power dissipation yield numerically tractable equations of motion beyond the adiabatic approximation, opening the door to the systematic study of systems far from equilibrium.
Measuring the internal energies of species emitted from hypervelocity nanoprojectile impacts on surfaces using recalibrated benzylpyridinium probe ions
Authors: DeBord J. Daniel , Verkhoturov Stanislav V. , Perez Lisa M. , North Simon W. , Hall Michael B. , Schweikert Emile A.
Published: June 2013

We present herein a framework for measuring the internal energy distributions of vibrationally excited molecular ions emitted from hypervelocity nanoprojectile impacts on organic surfaces. The experimental portion of this framework is based on the measurement of lifetime distributions of “thermometer” benzylpyridinium ions dissociated within a time of flight mass spectrometer. The theoretical component comprises re-evaluation of the fragmentation energetics of benzylpyridinium ions at the coupled-cluster singles and doubles with perturbative triples level. Vibrational frequencies for the ground and transition states of select molecules are reported, allowing for a full description of vibrational excitations of these molecules via Rice–Ramsperger–Kassel–Marcus unimolecular fragmentation theory. Ultimately, this approach is used to evaluate the internal energy distributions from the measured lifetime distributions. The average internal energies of benzylpyridinium ions measured from 440 keV Au400+4 impacts are found to be relatively low (∼0.24 eV/atom) when compared with keV atomic bombardment of surfaces (1–2 eV/atom).
Data analysis for Seebeck coefficient measurements
Authors: de Boor J. , Müller E.
Published: June 2013

The Seebeck coefficient is one of the key quantities of thermoelectric materials and routinely measured in various laboratories. There are, however, several ways to calculate the Seebeck coefficient from the raw measurement data. We compare these different ways to extract the Seebeck coefficient, evaluate the accuracy of the results, and show methods to increase this accuracy. We furthermore point out experimental and data analysis parameters that can be used to evaluate the trustworthiness of the obtained result. The shown analysis can be used to find and minimize errors in the Seebeck coefficient measurement and therefore increase the reliability of the measured material properties.
A constrained reduced-dimensionality search algorithm to follow chemical reactions on potential energy surfaces
Authors: Lankau Timm , Yu Chin-Hui
Published: June 2013

A constrained reduced-dimensionality algorithm can be used to efficiently locate transition states and products in reactions involving conformational changes. The search path (SP) is constructed stepwise from linear combinations of a small set of manually chosen internal coordinates, namely the predictors. The majority of the internal coordinates, the correctors, are optimized at every step of the SP to minimize the total energy of the system so that the path becomes a minimum energy path connecting products and transition states with the reactants. Problems arise when the set of predictors needs to include weak coordinates, for example, dihedral angles, as well as strong ones such as bond distances. Two principal constraining methods for the weak coordinates are proposed to mend this situation: static and dynamic constraints. Dynamic constraints are automatically activated and revoked depending on the state of the weak coordinates among the predictors, while static ones require preset control factors and act permanently. All these methods enable the successful application (4 reactions are presented involving cyclohexane, alanine dipeptide, trimethylsulfonium chloride, and azafulvene) of the reduced dimensionality method to reactions where the reaction path covers large conformational changes in addition to the formation/breaking of chemical bonds. Dynamic constraints are found to be the most efficient method as they require neither additional information about the geometry of the transition state nor fine tuning of control parameters.
An assessment of diamond anvil cell measurements on material strength
Authors: Vignes Ryan M. , Becker Richard , Stölken James , Kumar Mukul
Published: June 2013

Diamond anvil cell (DAC) experiments have been used in various studies to determine plastic flow strength in ductile metals at high pressure. To gain insight into the experiments and assess how accurately the material's strength at pressure can be determined, finite element simulations of DAC experiments are performed. In the analyses, constitutive responses are assumed for the diamonds and the vanadium test specimen; within the constitutive models, the pressure dependence of the strength is prescribed. The quantities typically measured during experiments are extracted from the simulations and analyzed in an identical manner as the experimental data would be to obtain the pressure dependent flow strength. This computed pressure dependent strength is then compared with the prescribed input, allowing the accuracy and sensitivities of the experimental technique to be evaluated. Recommendations are made to improve the accuracy of strength determinations.
Impacts of Si-doping and resultant cation vacancy formation on the luminescence dynamics for the near-band-edge emission of Al0.6Ga0.4N films grown on AlN templates by metalorganic vapor phase epitaxy
Authors: Chichibu S. F. , Miyake H. , Ishikawa Y. , Tashiro M. , Ohtomo T. , Furusawa K. , Hazu K. , Hiramatsu K. , Uedono A.
Published: June 2013

Luminescence dynamics for the near-band-edge (NBE) emission peak at around 250 nm of c-plane Si-doped Al0.6Ga0.4N films grown on AlN templates by low-pressure metalorganic vapor phase epitaxy were studied using deep ultraviolet time-resolved photoluminescence and time-resolved cathodoluminescence spectroscopies. For the films with the Si-doping concentration, [Si], lower than 1.9 × 1017 cm–3, the doping lessened the concentration of cation vacancies, [VIII], through the surfactant effect or the aid of the reactant doping in a form of H3SiNH2. However, the room-temperature nonradiative lifetime, and, consequently, the equivalent value of internal quantum efficiency in the weak excitation regime steeply decreased when [Si] exceeded 1018 cm−3. Simultaneously, the intensity ratio of the deep-state emission band to the NBE emission abruptly increased. Because the increase in [Si] essentially gives rise to the increase in [VIII] (for [Si]>1.9×1017 cm−3) and the overcompensation of Si is eventually observed for the film with [Si] = 4.0 × 1018 cm−3, the formation of acceptor-type native-defect complexes containing Si such as VIII-SiIII is suggested.
Towards quantized current arbitrary waveform synthesis
Authors: Mirovsky P. , Fricke L. , Hohls F. , Kaestner B. , Leicht Ch. , Pierz K. , Melcher J. , Schumacher H. W.
Published: June 2013

The generation of ac modulated quantized current waveforms using a semiconductor non-adiabatic single electron pump is demonstrated. In standard operation, the single electron pump generates a quantized output current of I = ef, where e is the charge of the electron and f is the pumping frequency. Suitable frequency modulation of f allows the generation of ac modulated output currents with different characteristics. By sinusoidal and saw tooth like modulation of f accordingly modulated quantized current waveforms with kHz modulation frequencies and peak currents up to 100 pA are obtained. Such ac quantized current sources could find applications ranging from precision ac metrology to on-chip signal generation.
Role of doped Ru in coercivity-enhanced La0.6Sr0.4MnO3 thin film studied by x-ray magnetic circular dichroism
Authors: Harano T. , Shibata G. , Ishigami K. , Takashashi Y. , Verma V. K. , Singh V. R. , Kadono T. , Fujimori A. , Takeda Y. , Okane T. , Saitoh Y. , Yamagami H. , Koide T. , Yamada H. , Sawa A. , Kawasaki M. , Tokura Y. , Tanaka A.
Published: June 2013

The coercivity of La1–xSrxMnO3 thin films can be enhanced by Ru substitution for Mn. In order to elucidate its mechanism, we performed soft x-ray absorption and magnetic circular dichroism measurements at the Ru M2,3 and Mn L2,3 edges. We found that the spin direction of Ru and Mn are opposite and that Ru has a finite orbital magnetic moment. Cluster-model analysis indicated that the finite orbital magnetic moment as well as the reduced spin moment of Ru result from local lattice distortion caused by epitaxial strain from the SrTiO3 substrate in the presence of spin-orbit interaction.
Quantum cascade laser absorption spectroscopy with the amplitude-to-time conversion technique for atmospheric-pressure plasmas
Authors: Yumii Takayoshi , Kimura Noriaki , Hamaguchi Satoshi
Published: June 2013

The NO2 concentration, i.e., density, in a small plasma of a nitrogen oxide (NOx) treatment reactor has been measured by highly sensitive laser absorption spectroscopy. The absorption spectroscopy uses a single path of a quantum cascade laser beam passing through a plasma whose dimension is about 1 cm. The high sensitivity of spectroscopy is achieved by the amplitude-to-time conversion technique. Although the plasma reactor is designed to convert NO in the input gas to NO2, it has been demonstrated by this highly sensitive absorption spectroscopy that NO2 in a simulated exhaust gas that enters the reactor is decomposed by the plasma first and then NO2 is formed again, possibly more than it was decomposed, through a series of gas-phase reactions by the time the gas exits the reactor. The observation is consistent with that of an earlier study on NO decomposition by the same type of a plasma reactor [T. Yumii et al., J. Phys. D 46, 135202 (2013)], in which a high concentration of NO2 was observed at the exit of the reactor.
Superconductivity up to 10 K in the Sr(Pd1−xPtx)2Ge2 layer system
Authors: Chen I. A. , Huang C. H. , Chen C. W. , You Y. B. , Tai M. F. , Ku H. C. , Hsu Y. Y.
Published: June 2013

Metastable filamentary superconductivity with Tc = 10.2 K was observed in SrPt2Ge2. This is the highest Tc reported outside the iron-based 122-layer compounds. The stable phase for this compound is a non-superconducting monoclinic LaPt2Ge2-type structure with lattice parameters a = 0.4401(4) nm, b = 0.4435(4) nm, c = 0.9764(10) nm, β = 90.5°–90°. Weak diamagnetic shielding signal indicates that superconductivity is not from the major monoclinic phase, but from the minor BaFe2As2-type body-center-tetragonal (122-bct) phase with a=0.44 nm, c=0.98 nm,β=90°. Investigation on the pseudoternary system Sr(Pd1−xPtx)2Ge2 suggests that the stable bct to monoclinic structure phase transition occurs near x = 0.15. For x<0.15 with bct phase, bulk Tc increases from 3.2 K for SrPd2Ge2 to 3.6 K for SrPd1.8Pt0.2Ge2. For x>0.15 with metastable filamentary bct phase, Tc increases from 7.5 K for x = 0.5 to 9.2 K for x = 0.7 and reaches a Tc maximum of 10.2 K for SrPt2Ge2. High Tc is due to a strong quasi-2D Pt-Ge-Pt 5dxz,yz-4p-5dxz,yz hybridization in the Pt-Ge layer with squeezed-along-c-axis PtGe4 tetrahedral crystal field and Pt-5d8 spin-orbital interaction in the metastable filamentary bct phase and is another example of multi-band (dxz/dyz/dxy) non-conventional s-wave superconductor.
Tunable periodic evolution and quantum phase transition in mesoscopic two-band superconducting loops
Authors: Zha Guo-Qiao , Wang Qiang , Zhou Shi-Ping
Published: June 2013

The magnetic flux dependence of the superconducting state evolution for mesoscopic two-band noncircular loops is studied by numerically solving the generalized Bogoliubov-de Gennes equations self-consistently. The crossover from hc / e- to hc/2e-flux periodicity of the current can be controlled by increasing the interband coupling strength or the temperature. For sufficiently small interband coupling, the order parameters of the two bands may exhibit different winding numbers in narrow flux ranges. Moreover, different patterns of flux-tuned quantum phase transitions between the superconducting state and the resistive/normal state, which are strongly sensitive to the temperature and the strength of the pairing interaction as well as the loop geometry, are demonstrated in the present two-band samples. Similar coherent phenomena are expected for the superconducting multi-layer or effectively multi-band systems.
Near room-temperature magnetoresistance effect in double perovskite La2NiMnO6
Authors: Guo Yuqiao , Shi Lei , Zhou Shiming , Zhao Jiyin , Liu Wenjie
Published: June 2013

Near room-temperature magnetoresistance (MR) effect in ferromagnetic semiconductor La2NiMnO6 has been reported. The magnetic field dependent MR curve exhibits two distinct regions: the low-field MR which shows a rapid increase in an applied field within 200 Oe and the high-field MR which shows a relatively slow increase with the field increasing (more than 200 Oe). Based on the analyses of magnetic and electronic properties, we suggest that the low-field MR comes from the increased electron tunneling probability accompanied by the alignment of ferromagnetic domains under external field and the high-field MR is due to the suppression of scattering from the spin defects arising from the Ni/Mn antisite disorders.
Anisotropic thermal conductivity of semiconducting graphene monoxide
Authors: Pu H. H. , Rhim S. H. , Hirschmugl C. J. , Gajdardziska-Josifovska M. , Weinert M. , Chen J. H.
Published: June 2013

The intrinsic thermal conductivity of monolayer graphene monoxide is determined via first-principles calculations. The phonon transport in graphene monoxide is anisotropic, with the lattice thermal conductivity along the armchair direction (…C-2O-C…) about five times higher than that along the zigzag (…C-C…) direction. The predicted thermal conductivity (>3000 Wm−1K−1 at 300 K) of graphene monoxide is 80% of that of graphene along the armchair direction for large sample lateral sizes (>5 μm). In addition, heat is predominantly carried by longitudinal acoustic phonons along the armchair direction, while the contribution from the transverse acoustic phonon mode is prevalent along the zigzag direction.
Single spin-torque vortex oscillator using combined bottom-up approach and e-beam lithography
Authors: Abreu Araujo F. , Piraux L. , Antohe V. A. , Cros V. , Gence L.
Published: June 2013

A combined bottom-up assembly of electrodeposited nanowires and electron beam lithography technique has been developed to investigate the spin transfer torque and microwave emission on specially designed nanowires containing a single Co/Cu/Co pseudo spin valve. Microwave signals have been obtained even at zero magnetic field. Interestingly, high frequency vs. magnetic field tunability was demonstrated, in the range 0.4–2 MHz/Oe, depending on the orientation of the applied magnetic field relative to the magnetic layers of the pseudo spin valve. The frequency values and the emitted signal frequency as a function of the external magnetic field are in good quantitative agreement with the analytical vortex model as well as with micromagnetic simulations.
Numerical modeling of DNA-chip hybridization with chaotic advection
Authors: Raynal Florence , Beuf Aurélien , Carrière Philippe
Published: June 2013

We present numerical simulations of DNA-chip hybridization, both in the “static” and “dynamical” cases. In the static case, transport of free targets is limited by molecular diffusion; in the dynamical case, an efficient mixing is achieved by chaotic advection, with a periodic protocol using pumps in a rectangular chamber. This protocol has been shown to achieve rapid and homogeneous mixing. We suppose in our model that all free targets are identical; the chip has different spots on which the probes are fixed, also all identical, and complementary to the targets. The reaction model is an infinite sink potential of width dh, i.e., a target is captured as soon as it comes close enough to a probe, at a distance lower than dh. Our results prove that mixing with chaotic advection enables much more rapid hybridization than the static case. We show and explain why the potential width dh does not play an important role in the final results, and we discuss the role of molecular diffusion. We also recover realistic reaction rates in the static case.
Field-induced resistive switching of (Ba0.6Sr0.4)TiO3 thin films based on switching of conducting domains model
Authors: He Xiliang , Li Xiaomin
Published: June 2013

Field-induced bipolar resistive switching (RS) properties were obtained in both epitaxially and nonepitaxially grown (Ba0.6Sr0.4)TiO3 (BSTO) thin films on Ir electrode. Results inferred that conducting domains were formed during the “forming” process, and the switching of conducting domains led to the RS process. And results showed that epitaxially grown BSTO (E-BSTO) thin film had higher resistance switching ratio than that of non-epitaxially grown BSTO (NE-BSTO) thin film, which was mainly resulted from the Poole-Frenkel emission, more and thinner conducting domains of E-BSTO thin film.
Atomistic geometry and bonding characteristics at the Sr2FeTaO6/SrTiO3 interface
Authors: Lv Shuhui , Saito Mitsuhiro , Wang Zhongchang , Chakraverty Suvankar , Kawasaki Masashi , Ikuhara Yuichi
Published: June 2013

Oxide heterointerfaces with broken translational symmetry offer a fertile ground for exploring fascinating physical properties that are absent in bulk constituents. Here, we apply advanced transmission electron microscopy to the Sr2FeTaO6/SrTiO3 interface and elucidate that the deposited Sr2FeTaO6 thin film bonds directly to the SrTiO3 substrate in an epitaxial, coherent, and atomically abrupt way. Combined with density-functional-theory calculations, we determine the explicit interface atomistic structure, the exact valence state of transition metals, the covalent interfacial bonding nature, and identify the antiferromagnetic superexchange magnetic coupling path between Fe ions as Fe-O-Ta-O-Fe.
Kinematic Parameters That Influence the Aesthetic Perception of Beauty in Contemporary Dance
Authors: Torrents Carlota , Castañer Marta , Jofre Toni , Morey Gaspar , Reverter Ferran
Published: June 2013

Some experiments have stablished that certain kinematic parameters can influence the subjective aesthetic perception of the dance audience. Neave, McCarty, Freynik, Caplan, Hönekopp, and Fink (2010, Biology Letters 7 221–224) reported eleven movement parameters in non-expert male dancers, showing a significant positive correlation with perceived dance quality. We aim to identify some of the kinematic parameters of expert dancers' movements that influence the subjective aesthetic perception of observers in relation to specific skills of contemporary dance. Four experienced contemporary dancers performed three repetitions of four dance-related motor skills. Motion was captured by a VICON-MX system. The resulting 48 animations were viewed by 108 observers. The observers judged beauty using a semantic differential. The data were then subjected to multiple factor analysis. The results suggested that there were strong associations between higher beauty scores and certain kinematic parameters, especially those related to amplitude of movement.
Vertical Size Disparity and the Correction of Stereo Correspondence
Authors: Mitsudo Hiroyuki , Sakai Ayumi , Kaneko Hirohiko
Published: June 2013

We examined the stage of vertical-disparity processing that produces a global stereoscopic slant. In two psychophysical experiments, we measured perceived slant about a vertical axis for two-dimensional stereoscopic patterns consisting of random dots, concentric lines, and radial lines. Binocular image differences were introduced into each pattern by vertically magnifying either the entire image for the right eye or that for the left eye. Because the continuous lines were geometrically ambiguous in local stereo correspondence, the three patterns differed from each other in the local horizontal disparity measured in retinal coordinates. The two experiments revealed that, despite the differences in the retinal horizontal disparity, the slant settings were generally similar for the three patterns, in both short and long viewing distances (25 cm and 120 cm, respectively). These results are consistent with the idea that the visual system uses vertical disparity at least when establishing local stereo correspondence. A Bayesian model is proposed to account for the results.
A New Method for Assessing Self-Touch Enhancement of the Foot in Stroke Patients with Mobility Problems
Authors: White Rebekah C , Davies Anne M Aimola
Published: June 2013

Patient NG is the first reported case of lower-limb ‘self-touch enhancement’ following stroke. Mobility problems prevented NG from reaching to touch her foot, thus we used a self-touch rubber-hand paradigm to mimic the conditions of self-administered touch. With vision precluded, NG administered stimulation to a prosthetic limb while the Examiner administered synchronous stimulation to NG's affected left foot. NG detected all stimulation administered with our self-touch paradigm, whereas in the control condition (with NG not involved in administering stimulation), NG had failed to detect one-third of Examiner-administered stimulation. When mobility problems are a barrier to investigating self-touch enhancement, the self-touch paradigm can be used to demonstrate residual tactile sensation following stroke.
Slant Perception for Stairs and Screens: Effects of Sex and Fatigue in a Laboratory Environment
Authors: Taylor-Covill Guy A H , Eves Frank F
Published: June 2013

The apparent slope of a hill or staircase, termed geographical slant perception, is exaggerated in explicit awareness. Across two experiments this paper tests the use of a laboratory environment to study geographical slant perception. First, using a student-aged sample ( N = 166), we examine the similarity of slant estimates in the field with those made in the laboratory using life-sized images of the built environment as stimuli. Results reveal no differences in slant estimates between the two test environments. Furthermore, three traditional measures of perceived geographical slant (verbal, visual, and haptic) appear sensitive to a difference in slant of only 3.4° in both the field and laboratory environments. In a follow-up experiment we test the effect of fatigue on slant estimates in the laboratory. In line with previous research with outdoor stimuli, fatigued participants provided more exaggerated explicit reports of slant relative to those in a control group, and females gave more exaggerated slant estimates than males across both experiments. The current set of findings open the door to future studies of geographical slant perception that may be more suited to laboratory conditions.
Algebraic Method for Large-Nc QCD
Authors: Hosaka Atsushi , Walet Niels R.
Published: June 2013

We discuss an algebraic method for
large-Nc baryon structure. In
addition to the widely used quark representation for the
large-Nc algebra, we consider
several other representations that reflect important dynamical effects. The
axial vector coupling constants both in the isoscalar (flavour-singlet) and
isovector sectors are discussed in detail. Importance of the pion degrees of
freedom is pointed out.
Shadowing Aspects of Nuclear Parton Distributions
Authors: Kumano S.
Published: June 2013

Various shadowing aspects of nuclear parton distributions are discussed in a
parton-model framework. We explain existing x dependent data of
F2A
/F2D,
then the model is applied to a flavour asymmetry –
d in a nucleus, to shadowing in valence-quark
distributions, and to nuclear dependence of
Q2 evolution. First, we find that
a finite nuclear ū – đ distribution could be
possible due to nuclear interactions even in the flavour symmetric case in the
nucleon ( ū – đ = 0). Second, it is indicated
that valence-quark shadowing could be used for discriminating among various
shadowing models. Third, we find that nuclear dependence of
Q2 evolution ∂
[F2Sn/F2C]/∂[ln
Q2], which was found by the
New Muon Collaboration (NMC), is essentially understood by modification of
parton distributions in nuclei. However, higher-twist effects in nuclear
interactions could be tested by studying the details of the nuclear
Q2 evolution.
Nonequilibrium Processes in Kaon Condensation
Authors: Muto Takumi , Tatsumi Toshitaka , Iwamoto Naoki
Published: June 2013

Relaxation in a kaon condensate proceeds through nonequilibrium weak
reactions, which includes the kaon-induced Urca and the modified Urca
reactions. The kinetics of a
K— condensate is considered
semiclassically starting from a small seed of a condensate with the assumption
that the system is in thermal equilibrium. It is shown that the temporal
evolution to the K—condensed
phase in the kinetic regime is divided into several characteristic time
intervals as a result of the interplay between the two major weak processes.
The implications for the dynamical evolution of newly-born neutron stars are
briefly discussed.
Structure Functions of Hadrons in the QCD Effective Theory
Authors: Shigetani Takayuki , Suzuki Katsuhiko , Toki Hiroshi
Published: June 2013

We study the structure functions of hadrons with the low energy effective
theory of QCD. We try to clarify a link between the low energy effective
theory, where non-perturbative dynamics is essential, and the high energy deep
inelastic scattering experiment. We calculate the leading twist matrix
elements of the structure function at the low energy model scale within the
effective theory. Calculated structure functions are taken to the high
momentum scale with the help of the perturbative QCD, and compared with the
experimental data. Through a comparison of the model calculations with the
experiment, we discuss how the non-perturbative dynamics of the effective
theory is reflected in the deep inelastic phenomena. We first evaluate the
structure functions of the pseudoscalar mesons using the NJL model. The
resulting structure functions show reasonable agreement with experiments. We
then study the quark distribution functions of the nucleon using a covariant
quark–diquark model. We calculate three leading twist distribution
functions, the spin-independent
f1(x), the
longitudinal spin distribution
g1(x), and
the chiral-odd transversity spin distribution
h1(x). The
results for
f1(x) and
g1(x) turn
out to be consistent with available experiments because of the strong spin-0
diquark correlation.
Boundary Effects in the Townsend-Huxley Experiment
Authors: England J. P. , Skullerud H. R.
Published: June 2013

The Townsend–Huxley transverse diffusion experiment has been modelled
using kinetic theory, with the aim of explaining the successes and
shortcomings of some current ratio formulae that are based on hydrodynamic
theory. These are shown to be essentially identical in form, apart from the
estimated magnitudes of the boundary layer corrections to the second and
fourth transverse position moments of the current density. The main reason for
the shortcomings is shown to be the inability of hydrodynamic theory to
describe the relaxation of the input electron energy distribution towards the
steady state free space form. As a byproduct of the studies, exact
eigensolutions have been found for the associated ‘infinite slab’
problem, using the constant collision frequency model with the two-term
approximation.
A Critical Comparison of Electron Scattering Cross Sections measured by Single Collision and Swarm Techniques
Authors: Buckman Stephen J. , Brunger Michael J.
Published: June 2013

Electron scattering cross sections (elastic, rotational and vibrational
excitation) for a number of atomic and (relatively) simple molecular systems
are examined. Particular reference is made to the level of agreeement which is
obtained from the application of the completely different measurement
philosophies embodied in ‘beam’ and ‘swar’ techniques.
The range of energies considered is generally restricted to the region below 5
eV.
Potential Energy Surfaces for Unsaturated Hydrocarbons from Crossed Molecular Beams
Authors: Stevenson K. P. , Close J. D. , Muiño P. L. , Watts R. O.
Published: June 2013

The total differential scattering cross sections for several important
unsaturated hydrocarbon molecules with common atmospheric gases were measured
in a crossed molecular beam apparatus. The experiments show quantum
interferences which relate to potential energy surface parameters, such as the
well depth and radial minimum. The damping of the quantum features, over
contributions from experimental resolutions, provides information on the
angular and radial anisotropies present in the potential energy surfaces. We
have investigated two areas: (1) the role of the probe partner in determining
the interaction strength for a given hydrocarbon target, and (2) the effect of
increasing the overall length of the hydrocarbon molecule for a fixed probe.
By comparing results for a class of scattering systems, we can identify
chemical and physical trends that determine the van der Waals potential energy
surfaces of larger molecules. We expect these results to aid in the prediction
and interpretation of complementary experimental measurements on the high
resolution infrared spectroscopy of weakly bound complexes.
Rotational and Vibrational Excitation of Nitrogen by Electron Impact
Authors: Robertson A. G. , Elford M. T. , Crompton R. W. , Morrison Michael A. , Sun Weiguo , Trail W. K.
Published: June 2013

Rotational excitation of nitrogen by low-energy electron impact has posed an
unsolved problem for more than three decades. Early analysis of the results of
swarm experiments in nitrogen found that the data could be matched remarkably
well by assuming that the energy dependences of the
Δj = 2 cross sections from threshold to a
few tenths of an eV are given by a simple formula based on the Born
approximation. Moreover, the quadrupole moment (the only adjustable parameter
in the formula) which gave the best fit to the data was commensurate with
existing experimental values. This finding posed an enigma, since the
quadrupole Born expression is known to incorrectly represent the interaction
potential for scattering except within a few meV of threshold. We have
analysed new swarm data, taken in a dilute mixure of nitrogen in neon, using
theoretical rotational and momentum transfer cross sections based on a
solution of the Schrödinger equation using static, exchange, and
polarisation potentials. This work explains the long-standing enigma and
provides the basis for a subsequent analysis in which theoretical vibrational
excitation cross sections are also investigated using the new swarm data for
the mixture.
Quasiparticle Lifetimes and the Conductivity Scattering Rate
Authors: Marsiglio F. , Carbotte J. P.
Published: June 2013

We compute the single-particle inverse lifetime, along with the
conductivity-derived scattering rate, for a metallic system in an s-wave
superconducting state. When both electron–phonon and electron-impurity
scattering are included, we find that while these scattering rates are in
qualitative agreement, in general quantitative agreement is lacking. We also
derive results for the quasiparticle lifetime within the BCS framework with
impurity scattering, which makes it clear that impurity scattering is
suppressed for electrons near the Fermi surface in the superconducting state.
Neutron Polarisation Analysis, Spin Glasses and Other Systems
Authors: Hicks T. J.
Published: June 2013

This paper describes neutron scattering experiments on a spin glass,
Cu–Mn, an inhomogeneous antiferromagnetic alloy, γ-Mn–Ni, and
the crystal field excitations in PrAl3. In all materials
the magnetic part of the scattering has been isolated using polarisation
analysis with the long wavelength polarised neutron
diffractometer–spectrometer (LONGPOL) installed at the HIFAR reactor at
Lucas Heights.
MAPON Spectroscopy and Its Application to Transition Metal Ferromagnets
Authors: Hutchison W. D. , Yazidjoglou N. , Chaplin D. H.
Published: June 2013

Modulated adiabatic passage on oriented nuclei (MAPON) is a technique
developed specifically to measure very small electric quadrupole interactions
(EQIs) at radioactive probe nuclei even when such interactions are masked in
the frequency domain by inhomogeneous magnetic broadening associated with a
dominant magnetic hyperfine interaction. In this paper an overview of the
technique is presented with particular reference to
60CoCo EQI measurements which were
an important step in establishing MAPON methodology. MAPON results for dilute
nd impurities in ferromagnetic Fe and Ni metal hosts are reviewed including
presentation of new data for
58CoNi and
60CoNi. Priorities for future
studies are provided on the basis of this review.
Investigating Inner Shell Ionisation via the (e, 2e) Technique
Authors: Lohmann Birgit , Cavanagh S. J. , Haynes M. A. , Taouil I. , Duguet A. , Lahmam-Bennani A.
Published: June 2013

The (e, 2e) technique has been applied successfully to valence shell
ionisation of many targets, but studies of inner shell ionisation by this
technique have been limited. The triple differential cross section for the
latter process exhibits behaviour which is very different to that observed for
valence shell ionisation, particularly when the energy of the slow ejected
electron is decreased below the binding energy of the inner shell orbital. Our
recent results for inner shell ionisation of argon and krypton will be
discussed, and comparisons made with distorted wave calculations.
Magnetic Behaviour of Implanted Transition Metal Probes at Different Lattice Sites in Metals
Authors: Riegel D. , Brewer W. D.
Published: June 2013

Usually, the occurrence of magnetism on isolated, substitutional
3d, 4d and
5d impurity ions in metals is restricted to certain
3d ions (mainly Cr, Mn, Fe, Co, Ni) in alloying metallic
systems. The application of the perturbed γ-ray distribution method
following heavy ion reactions and recoil implantation has offered an
experimental technique for producing and investigating new magnetic systems.
Of special importance are nonalloying systems, which can exhibit extreme
variations of e.g. density of states and atomic volume in the probe–host
combinations produced by recoil implantation. Recent developments in this
field include the following: Magnetism and the Kondo effect observed for
43Sc ions in alkali metal hosts are found to be
consistent with a nearly localised, ionic
3d1 single-electron configuration,
and parallel the behaviour observed in certain Ce systems. More generally,
essential features of the magnetism of 3d and
4d ions in sp metal hosts are
similar to those of 4f systems. Recent experimental and
theoretical studies of 54Fe in
d-band metal hosts are of key importance for an
understanding of the basic features of local moment formation on
substitutional Fe ions in transition metal hosts in general.
In many nonalloying 54Fe probe-host combinations, (at
least) two different magnetic responses have been detected. These components
correspond to substitutional and interstitial sites of the implanted probes,
as has been verified by in-beam Mössbauer spectroscopy of
57Fe in a series of host metals. This provides new
insight into lattice site occupation as a function of host properties and
allows directed investigations of the magnetic behaviour of Fe (and Mo) ions
on interstitial lattice sites. Depending on the host metal, interstitial Fe is
found to be nonmagnetic, e.g. in Zr, or magnetic, e.g. in Yb. Surprisingly,
even the 4d ion Mo can be magnetic on interstitial
sites. The experimental results for the substitutional as well as the
interstitial sites can be compared to extensive theoretical work within the
framework of local spin density calculations.
Phase Separation and Phase Diagram in Lightly Doped Manganites: Temperature and Magnetic Field Effects
Authors: Zou Liang-Jian , Lin H. Q.
Published: June 2013

The effects of magnetic field and temperature on the phase separation and
phase diagram of lightly doped manganites are studied. Based on the double
exchange model with on-site Coulomb interaction, we show that in the case of a
homogeneous charge distribution, the canting angle of localised core spins and
the critical doping concentration of the system from canted phase to
ferromagnetic (FM) phase become large because the effective FM coupling
between localised core spins is weakened when the temperature increases. The
boundary of the canted phase and FM phase shifts to a high doping
concentration regime at high temperatures. In comparison with with the
zero-temperature result, the phase separation can take place more easily in
lightly doped manganites at finite temperatures. The application of a magnetic
field decreases the energy of the FM cluster in the system, favours the
separation of the hole-rich FM phase from the antiferromagnetic (AFM)
background, and shifts the cant-FM border to the low doping regime. The effect
of the Jahn-Teller electron-phonon coupling on the phase diagram and phase
separation is also discussed.
Evolution of Ferromagnetism in LaMnO3+δ
Authors: Muroi Michihito , Street Robert
Published: June 2013

An extensive study has been made of the magnetic properties of
LaMnO3+δ with finely tuned hole
concentrations, x (=2δ), ranging between
0·08 and 0·15. As x increases in the range
studied, the spontaneous magnetisation at low temperature increases from only
about 20% to almost 100% of the value for full polarisation of
Mn spins, and the coercivity Hc
decreases by more than an order of magnitude, e.g. from 4·2 kOe to 120
Oe at 5 K. The magnetic ordering temperature
Tc takes a minimum at
x =
xc ~ 0·12. For
x < xc,
the inverse susceptibility shows a marked decrease as
Tc is approached from above.
Measurements of minor hysteresis loops for the sample with
x = 0·08 show that magnetisation is
reversible with respect to field changes except near
Hc. These observations are
discussed in terms of a two-phase exchange coupling (TPEC) model in which it
is assumed that at low temperature the system separates into two phases, a
hole-free antiferromagnetic phase and an optimally doped ferromagnetic phase,
and the two phases are coupled through superexchange interactions at the
interface.
Fibre Optic Shock Velocity Sensor for Solids
Authors: Szajman Jakub , Marzio Frank Di , Podlesak Michael
Published: June 2013

This paper reports a fibre optic sensing technique for the measurement of
shock velocity in solid materials. The shock-induced changes in the light
transmission properties of an optical fibre are employed as the principal
transduction mechanism. A polycarbonate flyer plate generated shock waves by
impacting a perspex target. The shock velocity was determined from the
difference in arrival times of the shock front at the spatially separated
optical fibres embedded in the target. The main advantage of this sensor
system lies in its simplicity and immunity to optical and radio frequency (RF)
noise. Consideration is also given to the effect of release waves on the
uniform shock pressure region generated by the ˚yer impact which can
degrade the accuracy of the velocity measurement.