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An effective media toolset for use in metamaterial design

Warne, Larry K.; Johnson, William A.; Langston, William L.; Sinclair, Michael B.

This paper introduces an effective-media toolset that can be used for the design of metamaterial structures based on metallic components such as split-ring resonators and dipoles, as well as dielectric spherical resonators. For demonstration purposes the toolset will be used to generate infrared metamaterial designs, and the predicted performances will be verified with full-wave numerical simulations.

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Uncertainty quantification in reacting flow

Najm, Habib N.; Berry, Robert D.; Debusschere, Bert

Chemically reacting flow models generally involve inputs and parameters that are determined from empirical measurements, and therefore exhibit a certain degree of uncertainty. Estimating the propagation of this uncertainty into computational model output predictions is crucial for purposes of reacting flow model validation, model exploration, as well as design optimization. Recent years have seen great developments in probabilistic methods and tools for efficient uncertainty quantification (UQ) in computational models. These tools are grounded in the use of Polynomial Chaos (PC) expansions for representation of random variables. The utility and effectiveness of PC methods have been demonstrated in a range of physical models, including structural mechanics, transport in porous media, fluid dynamics, aeronautics, heat transfer, and chemically reacting flow. While high-dimensionality remains nominally an ongoing challenge, great strides have been made in dealing with moderate dimensionality along with non-linearity and oscillatory dynamics. In this talk, I will give an overview of UQ in chemical systems. I will cover both: (1) the estimation of uncertain input parameters from empirical data, and (2) the forward propagation of parametric uncertainty to model outputs. I will cover the basics of forward PC UQ methods with examples of their use. I will also highlight the need for accurate estimation of the joint probability density over the uncertain parameters, in order to arrive at meaningful estimates of model output uncertainties. Finally, I will discuss recent developments on the inference of this density given partial information from legacy experiments, in the absence of raw data.

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SIRHEN : a data reduction program for photonic Doppler velocimetry measurements

Ao, Tommy; Dolan, Daniel H.

SIRHEN (Sandia InfraRed HEtrodyne aNalysis) is a program for reducing data from photonic Doppler velocimetry (PDV) measurements. SIRHEN uses the short-time Fourier transform method to extract velocity information. The program can be run in MATLAB (2008b or later) or as a Windows executable. This report describes the new Sandia InfraRed HEtrodyne aNalysis program (SIRHEN; pronounced 'siren') that has been developed for efficient and robust analysis of PDV data. The program was designed for easy use within Sandia's dynamic compression community.

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Perspectives on sensor based containment and surveillance technologies : gaps and trends

Schoeneman, Barry D.

To maintain effective containment surveillance (CS) system capabilities, the requirements for such systems must continue to evolve outpacing diversion capabilities, reduce costs, and meet the needs of the looming nuclear renaissance. What are the future sensor-based capabilities that must be available to support growing CS requirements and what are the technologies needed to provide the underlying capabilities? This presentation is intended to discuss the present gaps in sensor-based containment and surveillance relevant technologies, and future development trends which may address these gaps. Consumer driven technology development will represent a component rich source of technologies and devices that can find application in containment and surveillance tools helping to minimize the technology gaps. Recognizing and utilizing these sources is paramount to cost effective solutions. Where these gaps cannot be addressed by consumer based development, custom, CS specific approaches are the only solution.

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Results 72751–72775 of 99,299
Results 72751–72775 of 99,299