Diversity of supernovae Ia determined using equivalent widths of Si II 4000

Spectroscopic and photometric properties of low and high-z supernovae Ia (SNe Ia) have been analyzed in order to achieve a better understanding of their diversity and to identify possible SN Ia sub-types. We use wavelet transformed spectra in which one can easily measure spectral features. We investigate the \ion{Si}{II} 4000 equivalent width (EW_w\lbrace\ion{Si}{II}\rbrace). The ability and, especially, the ease in extending the method to SNe at high-$z$ is demonstrated. We applied the method to 110 SNe Ia and found correlations between EW_w\lbrace\ion{Si}{II}\rbrace and parameters related to the light-curve shape for 88 supernovae with available photometry. No evidence for evolution of EW_w\lbrace\ion{Si}{II}\rbrace with redshift is seen. Three sub-classes of SNe Ia were confirmed using an independent cluster analysis with only light-curve shape, colour, and EW_w\lbrace\ion{Si}{II}\rbrace. SNe from high-$z$ samples seem to follow a similar grouping to nearby objects. The EW_w\lbrace\ion{Si}{II}\rbrace value measured on a single spectrum may point towards SN Ia sub-classification, avoiding the need for expansion velocity gradient calculations.Comment: 12 pages, 5 figure

Electric field-modulated non-ohmic behavior of carbon nanotube fibers in polar liquids.

We report a previously unseen non-ohmic effect in which the resistivity of carbon nanotube fibers immersed in polar liquids is modulated by the applied electric field. This behavior depends on the surface energy, dielectric constant, and viscosity of the immersion media. Supported by synchrotron SAXS and impedance spectroscopy, we propose a model in which the gap distance, and thus the conductance, of capacitive interbundle junctions is controlled by the applied field.JT acknowledges generous financial support from: The Cambridge Commonwealth European and International Trust, CONACyT (Mexico), Dyson Ltd, and Pembroke College Cambridge. JJV acknowledges support from MINECO (Spain) and FP7-People-Marie Curie Action-CIG.This is the accepted manuscript. The final version is available from ACS at http://pubs.acs.org/doi/abs/10.1021/nn5030835

Study of the reaction dynamics of Li+HF, HCl by the crossed molecular beams method

The reactions of (I) Li + HF {yields} LiF + H and (II) Li + HCl {yields} LiCl + H have been studied by the crossed molecular beams method. Angular distributions [N({theta})] of product molecules have been measured at 4 collision energies (E{sub c}) ranging from about 2 to 9 kcal/mole and time-of-flight (TOF) measurements of product velocity distribution were made at approximately E{sub c} = 3 and 9 kcal/mole for both reactions (I) and (II). The combined N({theta}) and TOF results were used to generate contour maps of lithium-halide product flux in angle and recoil velocity in the center-of-mass (c.m.) frame. For reaction (I) at E{sub c} = 3 kcal/mole the c.m. angular distribution [T({theta})] shows evidence of complex formation with near forward-backward symmetry; slightly favored backward peaking is observed. The shape of this T({theta}) indicates there is significant parallel or antiparallel spatial orientation of initial and final orbital angular momentum {rvec L} and {rvec L}', even though with H departing L' must be rather small and {rvec L} = {rvec J}', where {rvec J}' is the final rotational angular momentum vector. It is deduced that coplanar reaction geometries are strongly favored. At E{sub c} = 8.7 kcal/mole the T({theta}) of reaction (I) becomes strongly forward peaked. The product translational energy distributions P(E{sub T}') at both these collision energies give an average E{sub T}' of ~55% of the total available energy; this appears consistent with a theoretically calculated late exit barrier to reaction. The T({theta}) at E{sub c} = 2.9 and 9.2 kcal/mole for reaction (II) are forward-sideways peaked. Most of the available energy (~70%) goes into recoil velocity at both E{sub c} for LiCl formation. This suggests a late energy release for this 11 kcal/mole exoergic reaction. Both reactions (I) and (II) show evidence of no more than a minor partitioning of energy into product vibrational excitation. Integral reactive cross sections ({sigma}{sub R}) are evaluated by integrating the product distributions in the c.m. frame and using small angle nonreactive scattering of Li as an absolute calibrant. Values of {sigma}{sub R} are: for LiF formation {sigma}{sub R} ~ 0.8 {Angstrom}{sup 2} and 0.94 {Angstrom}{sup 2} at E{sub c} = 3 and 8.7 kcal/mole, while for LiCl formation {sigma}{sub R} = 27 {Angstrom}{sup 2} and 42 {Angstrom}{sup 2} at E{sub c} = 2.9 and 9.2 kcal/mole, with estimated absolute and relative uncertainties of a factor of 2, and 30%, respectively. Average opacities for reaction have been estimated from the reaction cross sections and the extent of rotational excitation of products to be about 0.1 for reaction (I) and 1 for reaction (II), for L values allowed to react. These results are discussed in some detail with regard to the kinematic constraints, reaction dynamics and potential energy surfaces for these two reactions, and related experimental and theoretical work are noted. In addition, angular distributions of nonreactive scattering of Li off HF and HCl are measured at 4 different E{sub c} each. Rainbow structure is observed at low E{sub c} and the angular distributions are fit by a spherically symmetric piecewise analytic potential. The resulting values of the potential's well depth ({epsilon}) and minimum position (r{sub m} ) are: for Li + HF {epsilon} = 0.46 kcal/mole and r{sub m} = 4.34 {Angstrom} and for Li + HCl {epsilon} = 0.32 kcal/mole and r{sub m} = 4.7 {Angstrom}. These results differ significantly from some earlier estimates based on the measurements of integral scattering cross sections

Fundamental movement skills are more than run, throw and catch: The role of stability skills.

Introduction In motor development literature fundamental movement skills are divided into three constructs: locomotive, object control and stability skills. Most fundamental movement skills research has focused on children's competency in locomotor and object control skills. The first aim of this study was to validate a test battery to assess the construct of stability skills, in children aged 6 to 10 (M age = 8.2, SD = 1.2). Secondly we assessed how the stability skills construct fitted into a model of fundamental movement skill. Method The Delphi method was used to select the stability skill battery. Confirmatory factor analysis (CFA) was used to assess if the skills loaded onto the same construct and a new model of FMS was developed using structural equation modelling. Results Three postural control tasks were selected (the log roll, rock and back support) because they had good face and content validity. These skills also demonstrated good predictive validity with gymnasts scoring significantly better than children without gymnastic training and children from a high SES school performing better than those from a mid and low SES schools and the mid SES children scored better than the low SES children (all p < .05). Inter rater reliability tests were excellent for all three skills (ICC = 0.81, 0.87, 0.87) as was test retest reliability (ICC 0.87-0.95). CFA provided good construct validity, and structural equation modelling revealed stability skills to be an independent factor in an overall FMS model which included locomotor (r = .88), object control (r = .76) and stability skills (r = .81). Discussion This study provides a rationale for the inclusion of stability skills in FMS assessment. The stability skills could be used alongside other FMS assessment tools to provide a holistic assessment of children's fundamental movement skills. Copyright

Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012

Formalization of the classification pattern: Survey of classification modeling in information systems engineering

Formalization is becoming more common in all stages of the development of information systems, as a better understanding of its benefits emerges. Classification systems are ubiquitous, no more so than in domain modeling. The classification pattern that underlies these systems provides a good case study of the move towards formalization in part because it illustrates some of the barriers to formalization; including the formal complexity of the pattern and the ontological issues surrounding the ‘one and the many’. Powersets are a way of characterizing the (complex) formal structure of the classification pattern and their formalization has been extensively studied in mathematics since Cantor’s work in the late 19th century. One can use this formalization to develop a useful benchmark. There are various communities within Information Systems Engineering (ISE) that are gradually working towards a formalization of the classification pattern. However, for most of these communities this work is incomplete, in that they have not yet arrived at a solution with the expressiveness of the powerset benchmark. This contrasts with the early smooth adoption of powerset by other Information Systems communities to, for example, formalize relations. One way of understanding the varying rates of adoption is recognizing that the different communities have different historical baggage. Many conceptual modeling communities emerged from work done on database design and this creates hurdles to the adoption of the high level of expressiveness of powersets. Another relevant factor is that these communities also often feel, particularly in the case of domain modeling, a responsibility to explain the semantics of whatever formal structures they adopt. This paper aims to make sense of the formalization of the classification pattern in ISE and surveys its history through the literature; starting from the relevant theoretical works of the mathematical literature and gradually shifting focus to the ISE literature. The literature survey follows the evolution of ISE’s understanding of how to formalize the classification pattern. The various proposals are assessed using the classical example of classification; the Linnaean taxonomy formalized using powersets as a benchmark for formal expressiveness. The broad conclusion of the survey is that (1) the ISE community is currently in the early stages of the process of understanding how to formalize the classification pattern, particularly in the requirements for expressiveness exemplified by powersets and (2) that there is an opportunity to intervene and speed up the process of adoption by clarifying this expressiveness. Given the central place that the classification pattern has in domain modeling, this intervention has the potential to lead to significant improvements.The UK Engineering and Physical Sciences Research Council (grant EP/K009923/1)

The sixth data release of the Radial Velocity Experiment (RAVE). I. Survey description, spectra and radial velocities

The Radial Velocity Experiment (RAVE) is a magnitude-limited (9<I<12) spectroscopic survey of Galactic stars randomly selected in the southern hemisphere. The RAVE medium-resolution spectra (R~7500) cover the Ca-triplet region (8410-8795A). The 6th and final data release (DR6 or FDR) is based on 518387 observations of 451783 unique stars. RAVE observations were taken between 12 April 2003 and 4 April 2013. Here we present the genesis, setup and data reduction of RAVE as well as wavelength-calibrated and flux-normalized spectra and error spectra for all observations in RAVE DR6. Furthermore, we present derived spectral classification and radial velocities for the RAVE targets, complemented by cross matches with Gaia DR2 and other relevant catalogs. A comparison between internal error estimates, variances derived from stars with more than one observing epoch and a comparison with radial velocities of Gaia DR2 reveals consistently that 68% of the objects have a velocity accuracy better than 1.4 km/s, while 95% of the objects have radial velocities better than 4.0 km/s. Stellar atmospheric parameters, abundances and distances are presented in subsequent publication. The data can be accessed via the RAVE Web (http://rave-survey.org) or the Vizier database.Comment: 32 pages, 11 figures, accepted for publication to A