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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,333 records · Page 74
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Fitting of Failure Rate Data to a Closed Form Solution using Gamma-Poisson Method of Moments

Due to the responsibility and gravity of estimation of nuclear power plant failure rates, it is required that there be consistent and accurate methodology for describing the likelihood of an event occurring. However, the methodology currently employed can vary dependent on the data, as well as subjective conjecture from the expert performing the analysis. The current implementation of the empirical Bayes method to a Gamma-Poisson (GaP) distribution utilizes algorithms to solve for the parameters that do not provide consistent answers. Additionally, to achieve a distribution of the likelihood, the variance of each parameter of the GaP must be determined. There does not exist an exact solution to one of the parameters variance and is typically estimated using techniques like the Kass-Steffey adjustment. Thus a new approach to the problem is proposed, built upon the method of moments for a negative binomial, based upon the work of Bradlow. Using the method of moments approach, we are able to achieve a closed form estimation of the mean and variance for each parameter in the negative binomial distribution. Due to the relationship between the negative binominal and GaP distribution, results can be made between the distributions. The hyper-priors defined assume beta prime distribution which is appropriately informed; the results of this application translate back to the Gamma distribution for easy utilization in SAPHIRE. Additionally several cases are explored using publically available NRC data that considers zero inflated, over dispersed, and Poisson data.

Failure Rate↗
DOE OSTI2018

Interconnect system with friction fit backshell

Various technologies described herein pertain to interconnect systems for electrical cables. An interconnect system can include a connector, an adapter ring, and a backshell. The connector includes a threaded distal coupling portion. The adapter ring includes a threaded proximal coupling portion and a non-threaded distal coupling portion. The backshell includes a proximal coupling portion and a port. The threaded proximal coupling portion of the adapter ring and the threaded distal coupling portion of the connector can be mechanically attached. Additionally, the proximal coupling portion of the backshell and the non-threaded distal coupling portion of the adapter ring can be mechanically attached. A wire bundle can enter the backshell through the port, pass through the adapter ring, and terminate at the connector. A shield that encloses the wire bundle can terminate at the backshell such that an end of the shield is positioned around an outer surface of the port.

42 ENGINEERING↗
DOE OSTI2018

Interconnect system with friction fit backshell

Various technologies described herein pertain to interconnect systems for electrical cables. An interconnect system can include a connector, an adapter ring, and a backshell. The connector includes a threaded distal coupling portion. The adapter ring includes a threaded proximal coupling portion and a non-threaded distal coupling portion. The backshell includes a proximal coupling portion and a port. The threaded proximal coupling portion of the adapter ring and the threaded distal coupling portion of the connector can be mechanically attached. Additionally, the proximal coupling portion of the backshell and the non-threaded distal coupling portion of the adapter ring can be mechanically attached. A wire bundle can enter the backshell through the port, pass through the adapter ring, and terminate at the connector. A shield that encloses the wire bundle can terminate at the backshell such that an end of the shield is positioned around an outer surface of the port.

42 ENGINEERING↗
DOE OSTI2020

Global analysis peak fitting for chemical spectroscopy data

The present invention relates to methods for analyzing a chemical sample. For instance, the methods herein allow for global analysis of spectroscopy data in order to extract useful chemical properties from complicated multidimensional data. Such analysis can optionally employ data compression to further expedite computer-implemented computation. In particular, the methods herein provide global analysis of data matrices explained by both linear and non-linear terms.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

NSUF Research Reactor Fitness Workshop Results

The Nuclear Science User Facilities has been working with the National Organization of Test, Research, and Training Reactors to collect input from the US university reactor community on their current and future needs. The effort started with a web survey in March to collect initial data. NSUF held a follow-up workshop in July at the Center for Advanced Energy Studies in Idaho Falls. We identified four areas of interest in the university research reactor community that can affect future operations and sustainability of the reactors: capital infrastructure, regulatory burden, staffing and knowledge transfer, and utilization and relevancy. Members of the community presented challenges and best practices from their facilities. Discussions were held to create and distill the list of challenges for each area. A working group was formed for each area to continue the discussion and prioritize the challenges. NSUF and the working groups intend to create a final recommendations report by the end of the year. This panel session will discuss the workshop and summarize the discussion in the four topic areas. The audience is encouraged to add to the discussion.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗