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Security and Emergency Management: NMPEA Application

Newman, Richard; Mcpeek, Eugene E.; Showalter, Roger L.; Flores, Samantha; Wright, Emily D.; Hovland, Deborah A.; Foulk, James W.

The Security and Emergency Management (S&EM) Center at Sandia National Laboratories (SNL) is responsible for ensuring overall security for people, information, and facilities at SNL. The center runs a broad Security and Emergency Management Program in close cooperation with other organizations throughout SNL. The mission of the Security program is to minimize current and future security threats so that Sandia can protect, sustain and enhance SNL’s ability to function as a multidisciplinary national security laboratory. The mission of the Emergency Management program is to provide SNL with dedicated professionals who deliver safe, prompt, courteous, efficient emergency planning and response to fire-related incidents, hazardous materials, confined space, emergency medical emergencies, and non-emergency events to protect the workers, the public and the environment. They embrace mission success in the National Interest, actively supporting all Divisions. The Emergency Management (EM) Program’s vision is to be recognized by SNL/NM and the entire DOE complex as the model for superior emergency management services. Emergency Management plans to accomplish this vision through a leadership philosophy that promotes respect and mutual trust among all members through open and honest communication.

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TYPE Other Report YEAR 2016
DOIOSTI

Damping optimization for wave energy converters with compressible volumes

Sandia journal manuscript; Not yet accepted for publication

Bacelli, Giorgio; Neary, Vincent S.; Murphy, Andrew

The addition of a compressible degree of freedom (CDOF) to a wave energy converter (WEC)-which results in a compressible WEC-has been shown to significantly increase power absorption compared to a rigid WEC of the same shape and mass for a variety of architectures. This study demonstrates that a compressible point absorber, with a passive power-take-off (PTO) and optimized damping, can also achieve equal or better performance levels than an optimally controlled rigid point absorber (with the same shape and mass) using reactive power from the PTO. Wave energy is converted to mechanical energy in both cases using a linear damper PTO, with the PTO coefficient optimized for each resonance frequency and compressible volume. The large compressible volume required to tune the compressible point absorber to the desired frequency is a practical limitation that needs to be addressed with further research, especially for low frequencies. While realistic, these auxiliary units would increase the CapEx and OpEx costs, potentially reducing the aforementioned benefits gained by CDOF. However, alternative approaches can be developed to implement CDOF without the large compressible volume requirements, including the development of flexible surface panels tuned with mechanical springs.

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TYPE Journal Article YEAR 2016
OSTI

White Paper on Dish Stirling Technology: Path Toward Commercial Deployment

Andraka, Charles E.; Stechel, Ellen; Becker, Peter; Messick, Brian

Dish Stirling energy systems have been developed for distributed and large-scale utility deployment. This report summarizes the state of the technology in a joint project between Stirling Energy Systems, Sandia National Laboratories, and the Department of Energy in 2011. It then lays out a feasible path to large scale deployment, including development needs and anticipated cost reduction paths that will make a viable deployment product.

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TYPE SAND Report YEAR 2016
DOIOSTI

Classification of background suppression profiles for low background RPM data

Shokair, Isaac R.; Homan, Rossitza

Suppression of the ambient gamma background radiation by traffic structure and cargo is a well-understood and studied effect for deployed radiation portal monitors (RPM). For effective analysis of measured RPM profiles with the objective of inferring the spatial characteristics of radiation sources, it is important to account for the effects of background suppression. In this report we analyze background suppression for a test dataset from vehicle RPMs at a sample port and estimate the distributions of suppression amplitudes and shapes. Cluster analysis of standardized and normalized profiles is used to obtain the dominant suppression shapes in the sample field data. We determine that a large fraction of non-alarm RPM occupancies are represented by a small number of suppression shapes. This fraction increases when the signal-to-noise ratio of an occupancy profile is improved by the addition of signals for multiple RPM detectors located at the same height. The calculated suppression shapes from RPM data can be used along with source models in the process of spatial profile analysis both in the field or offline. This background suppression analysis is an important step in improving the effectiveness of the RPM profile analysis methodology which is currently being investigated and may lead to methods that reduce the number of secondary inspections as well as to decision support tools that aid operators in evaluating RPM data that do not contain spectral information.

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TYPE SAND Report YEAR 2016
DOIOSTI

Stability of Peridynamic Correspondence Material Models and Their Particle Discretizations

Silling, Stewart

Peridynamic correspondence material models provide a way to combine a material model from the local theory with the inherent capabilities of peridynamics to model long-range forces and fracture. However, correspondence models in a typical particle discretization suffer from zero-energy mode instability. These instabilities are shown here to be an aspect of material stability. A stability condition is derived for state-based materials starting from the requirement of potential energy minimization. It is shown that all correspondence materials fail this stability condition due to zero-energy deformation modes of the family. To eliminate these modes, a term is added to the correspondence strain energy density that resists deviations from a uniform deformation. The resulting material model satisfies the stability condition while effectively leaving the stress tensor unchanged. Computational examples demonstrate the effectiveness of the modified material model in avoiding zero-energy mode instability in a peridynamic particle code.

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TYPE SAND Report YEAR 2016
DOIOSTI
Results 41001–41200 of 99,299
Results 41001–41200 of 99,299