Sandia National Laboratories

About: Sandia National Laboratories is a facility organization based out in Livermore, California, United States. It is known for research contribution in the topics: Laser & Thin film. The organization has 21501 authors who have published 46724 publications receiving 1484388 citations. The organization is also known as: SNL & Sandia National Labs.

Near-ideal theoretical strength in gold nanowires containing angstrom scale twins

Abstract: Low-dimensional materials containing defects such as twin boundaries are known to fail well below their theoretical strength due to surface imperfections. Here, Wang et al. observe strengths close to the ideal limit in gold nanowires with angstrom scale twins, where homogeneous dislocation nucleation controls deformation.

Ensemble-Vis: A Framework for the Statistical Visualization of Ensemble Data

Abstract: Scientists increasingly use ensemble data sets to explore relationships present in dynamic systems. Ensemble data sets combine spatio-temporal simulation results generated using multiple numerical models, sampled input conditions and perturbed parameters. While ensemble data sets are a powerful tool for mitigating uncertainty, they pose significant visualization and analysis challenges due to their complexity. In this article, we present Ensemble-Vis, a framework consisting of a collection of overview and statistical displays linked through a high level of interactivity. Ensemble-Vis allows scientists to gain key scientific insight into the distribution of simulation results as well as the uncertainty associated with the scientific data. In contrast to methods that present large amounts of diverse information in a single display, we argue that combining multiple linked displays yields a clearer presentation of the data and facilitates a greater level of visual data analysis. We demonstrate our framework using driving problems from climate modeling and meteorology and discuss generalizations to other fields.

Calculations of Mott scattering cross section

Abstract: Calculations of Mott elastic scattering cross section of electrons for most elements of the periodic table up to element number 94 in the energy range 20 eV–20 keV have been performed. The Dirac equation transformed to a first‐order differential equation was solved numerically. The influence of the choice of atomic potential on the scattering factor was studied in comparison to a simple muffin‐tin approximation of the atomic potential in solids. The application of calculated cross sections to a conventional Monte Carlo model for electron scattering using modified Bethe equation is described and results concerning the electron backscattering for different atomic potentials are compared.

Systematic wavelength selection for improved multivariate spectral analysis

Abstract: Methods and apparatus for determining in a biological material one or more unknown values of at least one known characteristic (e.g. the concentration of an analyte such as glucose in blood or the concentration of one or more blood gas parameters) with a model based on a set of samples with known values of the known characteristics and a multivariate algorithm using several wavelength subsets. The method includes selecting multiple wavelength subsets, from the electromagnetic spectral region appropriate for determining the known characteristic, for use by an algorithm wherein the selection of wavelength subsets improves the model's fitness of the determination for the unknown values of the known characteristic. The selection process utilizes multivariate search methods that select both predictive and synergistic wavelengths within the range of wavelengths utilized. The fitness of the wavelength subsets is determined by the fitness function F=f (cost, performance). The method includes the steps of: (1) using one or more applications of a genetic algorithm to produce one or more count spectra, with multiple count spectra then combined to produce a combined count spectrum; (2) smoothing the count spectrum; (3) selecting a threshold count from a count spectrum to select these wavelength subsets which optimize the fitness function; and (4) eliminating a portion of the selected wavelength subsets. The determination of the unknown values can be made: (1) noninvasively and in vivo; (2) invasively and in vivo; or (3) in vitro.