212 research outputs found

    Hanford Low-activity Waste Glass Composition-temperature-melt Viscosity Relationships

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    This study developed a model for predicting viscosity of alkali-alumino-borosilicate glass melts as functions of composition and temperature. The model is based on a total of 3935 viscosity-temperature data from 574 glasses with viscosity values ranging from 2.53 to 7260 Poise (P) in the temperature range of 900–1260°C. Several different model forms were surveyed, including those based on Arrhenius, Vogel-Fulcher-Tammann, Avramov-Milchev, and Mauro-Yue-Ellison-Gupta-Allen. For each of these models, combinations of the temperature-independent parameters were fitted to composition. It was found that generally fitting more than one temperature-independent parameter as functions of composition resulted in overfitting. The Avramov-Milchev-based model was found to best represent the Hanford low-activity waste glass melt viscosity data based on model fit and validation statistics. A 21-term partial quadratic mixture model was recommended for use. This model predicts melt viscosity with a root-mean square error of.1736 ln(P), which is similar to the error in viscosity measurements from replicate glass analyses of.1383 ln(P). Viscosity was found to be most increased by SiO2 \u3e Al2O3 \u3e ZrO2 \u3e SnO2 and most decreased by Li2O \u3e Na2O \u3e B2O3 \u3e CaO \u3e K2O \u3e MgO, at temperatures from 900 to 1260°C

    Identification of atypical flight patterns

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    Method and system for analyzing aircraft data, including multiple selected flight parameters for a selected phase of a selected flight, and for determining when the selected phase of the selected flight is atypical, when compared with corresponding data for the same phase for other similar flights. A flight signature is computed using continuous-valued and discrete-valued flight parameters for the selected flight parameters and is optionally compared with a statistical distribution of other observed flight signatures, yielding atypicality scores for the same phase for other similar flights. A cluster analysis is optionally applied to the flight signatures to define an optimal collection of clusters. A level of atypicality for a selected flight is estimated, based upon an index associated with the cluster analysis

    Census politics in deeply divided societies

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    Population censuses in societies that are deeply divided along ethnic, religious or linguistic lines can be sensitive affairs – particularly where political settlements seek to maintain peace through the proportional sharing of power between groups. This brief sets out some key findings from a research project investigating the relationship between census politics and the design of political institutions in Bosnia and Herzegovina, Kenya, Lebanon and Northern Ireland

    A multidimensional view? Evaluating the different and combined contributions of diaries and interviews in an exploration of asexual identities and intimacies

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    This article evaluates the relative contributions of diaries and interviews in multiple methods qualitative research exploring asexual identities and intimacies. Differentiated by three core differences: reflective time-frame (the day just had/lifetime), context (alone/with researcher) and mode (written/verbal), these methods had the potential to generate a multidimensional view of our topics. Using five cases in which data from both interviews and diaries were collected, this article explores how the intermeshed issues of identity and intimacy were constructed in each method, as well as reflecting on what was gained by their combination. Our analysis leads us to conclude that multiple methods do not always produce a fuller or a more rounded picture of individual participants’ lives. Nevertheless, the decision to collect data using different strategies did increase our chances of finding a method that suited individual participants, whether in style or focus

    Narratives of self and identity in women's prisons: stigma and the struggle for self-definition in penal regimes

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    A concern with questions of selfhood and identity has been central to penal practices in women's prisons, and to the sociology of women's imprisonment. Studies of women's prisons have remained preoccupied with women prisoners’ social identities, and their apparent tendency to adapt to imprisonment through relationships. This article explores the narratives of women in two English prisons to demonstrate the importance of the self as a site of meaning for prisoners and the central place of identity in micro-level power negotiations in prisons

    Second Line of Defense Spares Program

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    During Fiscal Year 2012, a team from the Pacific Northwest National Laboratory (PNNL) conducted an assessment and analysis of the Second Line of Defense (SLD) Sustainability spare parts program. Spare parts management touches many aspects of the SLD Sustainability Program including contracting and integration of Local Maintenance Providers (LMP), equipment vendors, analyses and metrics on program performance, system state of health, and maintenance practices. Standardized spares management will provide better data for decisions during site transition phase and will facilitate transition to host country sustainability ownership. The effort was coordinated with related SLD Sustainability Program initiatives, including a configuration items baselining initiative, a metrics initiative, and a maintenance initiative. The spares study has also led to pilot programs for sourcing alternatives that include regional intermediate inventories and partnering agreements that leverage existing supply chains. Many partners from the SLD Sustainability program contributed to and were consulted in the course of the study. This document provides a description of the findings, recommendations, and implemented solutions that have resulted from the study

    Hanford Waste Physical and Rheological Properties: Data and Gaps

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    The Hanford Site in Washington State manages 177 underground storage tanks containing approximately 250,000 m3 of waste generated during past defense reprocessing and waste management operations. These tanks contain a mixture of sludge, saltcake and supernatant liquids. The insoluble sludge fraction of the waste consists of metal oxides and hydroxides and contains the bulk of many radionuclides such as the transuranic components and 90Sr. The saltcake, generated by extensive evaporation of aqueous solutions, consists primarily of dried sodium salts. The supernates consist of concentrated (5-15 M) aqueous solutions of sodium and potassium salts. The 177 storage tanks include 149 single-shell tanks (SSTs) and 28 double -hell tanks (DSTs). Ultimately the wastes need to be retrieved from the tanks for treatment and disposal. The SSTs contain minimal amounts of liquid wastes, and the Tank Operations Contractor is continuing a program of moving solid wastes from SSTs to interim storage in the DSTs. The Hanford DST system provides the staging location for waste feed delivery to the Department of Energy (DOE) Office of River Protection’s (ORP) Hanford Tank Waste Treatment and Immobilization Plant (WTP). The WTP is being designed and constructed to pretreat and then vitrify a large portion of the wastes in Hanford’s 177 underground waste storage tanks

    Utility of Social Modeling in Assessment of a State’s Propensity for Nuclear Proliferation

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    This report is the third and final report out of a set of three reports documenting research for the U.S. Department of Energy (DOE) National Security Administration (NASA) Office of Nonproliferation Research and Development NA-22 Simulations, Algorithms, and Modeling program that investigates how social modeling can be used to improve proliferation assessment for informing nuclear security, policy, safeguards, design of nuclear systems and research decisions. Social modeling has not to have been used to any significant extent in a proliferation studies. This report focuses on the utility of social modeling as applied to the assessment of a State's propensity to develop a nuclear weapons program

    Information Display System for Atypical Flight Phase

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    Method and system for displaying information on one or more aircraft flights, where at least one flight is determined to have at least one atypical flight phase according to specified criteria. A flight parameter trace for an atypical phase is displayed and compared graphically with a group of traces, for the corresponding flight phase and corresponding flight parameter, for flights that do not manifest atypicality in that phase
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