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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 649 records · Page 36
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Thermodynamic Functions and Electrical Resistivity of Fluid Lead in the Metal–Nonmetal Transition Range

A dynamic method is used to measure the thermodynamic functions and the electrical resistivity of fluid lead for a wide range of specific volume and pressure. The measurements errors have been reduced to a level comparable to those of stationary methods. It is found that the transition of the fluid from the metallic state to a nonmetallic state occurs when its specific volume increases 2.7 times relative to the normal value. In each individual experiment the transition occurred at almost a constant pressure, and was detected by the change in sign of the isochoric temperature coefficient of resistance determined for the entire series of the experiments. In the pressure range of 0.6–5 GPa, the specific volume at which the metal–nonmetal transition occurs is found to be independent of pressure, and therefore, the transition line is close to an isochore. For the whole range of states of fluid lead investigated here, the speed of sound and the Grüneisen coefficient have been determined.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2017

Energy dependence of the cross sections for the e{sup +}e{sup –} → hadrons process near the production threshold for the NN̄ pair

The energy dependence of the cross sections for the processes e{sup +}e{sup −} → π{sup +}π{sup −}π{sup 0}, K{sup +}K{sup −}, ηπ{sup +}π{sup −}, ωπ{sub 0}, and K{sup +}K{sup −}π{sup +}π{sup −} is studied near the production threshold for a nucleon–antinucleon pair. It is shown that, within the measurement errors, the cross sections in question behave smoothly in this energy region.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2016

Comparison of statistical and deterministic frameworks of uncertainty quantification

Two different approaches to the prediction problem are compared employing a realistic example— combustion of natural gas—with 102 uncertain parameters and 76 quantities of interests. One approach, termed bound-to-bound data collaboration (abbreviated to B2B), deploys semidefinite programming algorithms where the initial bounds on unknowns are combined with initial bounds of experimental data to produce new uncertainty bounds for the unknowns that are consistent with the data and, finally, deterministic uncertainty bounds for prediction in new settings. The other approach is statistical and Bayesian, referred to as BCP (for Bayesian calibration and prediction). It places prior distributions on the unknown parameters and on the parameters of the measurement error distributions and produces posterior distributions for model parameters and posterior distributions for model predictions in new settings. The predictions from the two approaches are consistent; a very large degree of overlap exists between B2B bounds and the support of the BCP predictive distribution. Interpretation and comparison of the results is closely connected with assumptions made about the model and experimental data and how they are used in both settings. As a result, the principal conclusion is that use of both methods protects against possible violations of assumptions in the BCP approach and conservative specifications and predictions using B2B.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2026

Robust Optimal Experimental Design of Infinite-Dimensional Bayesian Nonlinear Inverse Problems

Abstract. We consider robust optimal experimental design (ROED) for nonlinear Bayesian inverse problems governed by partial differential equations (PDEs). An optimal design is one that maximizes some utility quantifying the quality of the solution of an inverse problem. However, the optimal design is dependent on elements of the inverse problem such as the simulation model, the prior, or the measurement error model. ROED aims to produce an optimal design that is aware of the additional uncertainties encoded in the inverse problem and remains optimal even after variations in them. We follow a worst-case scenario approach to develop a new framework for robust optimal design of nonlinear Bayesian inverse problems. The proposed framework (a) is scalable and designed for infinite-dimensional Bayesian nonlinear inverse problems constrained by PDEs; (b) develops efficient approximations of the utility, namely the expected information gain; (c) employs eigenvalue sensitivity techniques to develop analytical forms and efficient evaluation methods of the gradient of the utility with respect to the uncertainties against which we wish to be robust; and (d) employs a probabilistic optimization paradigm that properly defines and efficiently solves the resulting combinatorial max-min optimization problem. The effectiveness of the proposed approach is illustrated for optimal sensor placement problem in an inverse problem governed by an elliptic PDE.

Chowdhary, Abhijit↗
DOE OSTI2018

Testing Lithium-Ion Battery with the Internal Reference Electrode: An Insight into the Blocking Effect

Long-term stability of reference electrode is a major issue in lithium-ion batteries. A composite Ni-Li reference electrode (RE) with a longer lifetime than traditional Cu-wire Li reference electrodes is proposed in this study. However, the larger size of the Ni-Li RE creates a blocking effect when positioned internally in the battery. The blocking effect manifests as an abnormal feature in the measured electrode potential. A two-dimensional (2D) finite element model of the cell with an internal RE is constructed to investigate the mechanism of the blocking effect. The internal RE blocks the path of local current flow in the electrolyte, and decreases the electrochemical reaction rate of particles in the anode and cathode, leading to measurement errors. Characteristic lengths of RE and applied currents were examined as parameters in the finite element model to determine their effect on the magnitude of error. A useful guide is provided for proper selection of size of RE and applied current in dynamic tests of lithium-ion batteries.

2-D finite element model↗
DOE OSTI2016

Advanced Computational Framework for Environmental Management ZEM, Version 1.x

Typically environmental management problems require analysis of large and complex data sets originating from concurrent data streams with different data collection frequencies and pedigree. These big data sets require on-the-fly integration into a series of models with different complexity for various types of model analyses where the data are applied as soft and hard model constraints. This is needed to provide fast iterative model analyses based on the latest available data to guide decision-making. Furthermore, the data and model are associated with uncertainties. The uncertainties are probabilistic (e.g. measurement errors) and non-probabilistic (unknowns, e.g. alternative conceptual models characterizing site conditions). To address all of these issues, we have developed an integrated framework for real-time data and model analyses for environmental decision-making called ZEM. The framework allows for seamless and on-the-fly integration of data and modeling results for robust and scientifically-defensible decision-making applying advanced decision analyses tools such as Bayesian- Information-Gap Decision Theory (BIG-DT). The framework also includes advanced methods for optimization that are capable of dealing with a large number of unknown model parameters, and surrogate (reduced order) modeling capabilities based on support vector regression techniques. The framework is coded in Julia, a state-of-the-art high-performance programing language (http://julialang.org). The ZEM framework is open-source and can be applied to any environmental management site. The framework will be open-source and released under GPL V3 license.

Vesselinov, VelimirV.↗
DOE OSTI2014

Lipid Informed Quantitation and Identification

LIQUID (Lipid Informed Quantitation and Identification) is a software program that has been developed to enable users to conduct both informed and high-throughput global liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based lipidomics analysis. This newly designed desktop application can quickly identify and quantify lipids from LC-MS/MS datasets while providing a friendly graphical user interface for users to fully explore the data. Informed data analysis simply involves the user specifying an electrospray ionization mode, lipid common name (i.e. PE(16:0/18:2)), and associated charge carrier. A stemplot of the isotopic profile and a line plot of the extracted ion chromatogram are also provided to show the MS-level evidence of the identified lipid. In addition to plots, other information such as intensity, mass measurement error, and elution time are also provided. Typically, a global analysis for 15,000 lipid targets.

Crowell, Kevin↗
DOE OSTI2022

Code for paper "Reconstructing an Implosion with Space-Time Smoothing of Velocimetry Traces"

New diagnostics to obtain high-temporal resolution observation of surface velocity provide a rich collection of data from high-explosive (HE) experiments. Using this data to estimate the temporal evolution of an imploding, HE-driven surface is of great interest for validating simulation of the physical system and for design of future experiments. This is the code for a paper in which we propose a method for using a Gaussian process to estimate the surface position over time and provide uncertainty estimates on that reconstruction accounting for measurement error, uncertainty to sparse spatial sampling velocity data, and robustness to outlying observations. In the paper, the code is applied on data from a hemispherical HE implosion experiment. This code is for release with the paper for peer-review, replicating the results and making the figures from the paper.

Grosskopf, Michael↗
DOE OSTI2017

Quantifying the Accuracy and Uncertainty of Diurnal Thermodynamic Profiles and Convection Indices Derived from the Atmospheric Emitted Radiance Interferometer

Abstract While radiosondes have provided atmospheric scientists an accurate high-vertical-resolution profile of the troposphere for decades, they are unable to provide high-temporal-resolution observations without significant recurring expenses. Remote sensing technology, however, has the ability to monitor the evolution of the atmosphere in unprecedented detail. One particularly promising tool is the Atmospheric Emitted Radiance Interferometer (AERI), a passive ground-based infrared radiometer. Through a physical retrieval, the AERI can retrieve the vertical profile of temperature and humidity at a temporal resolution on the order of minutes. The synthesis of these two instruments may provide an improved diagnosis of the processes occurring in the atmosphere. This study provides a better understanding of the capabilities of the AERI in environments supportive of deep, moist convection. Using 3-hourly radiosonde launches and thermodynamic profiles retrieved from collocated AERIs, this study evaluates the accuracy of AERI-derived profiles over the diurnal cycle by analyzing AERI profiles in both the convective and stable boundary layers. Monte Carlo sampling is used to calculate the distribution of convection indices and compare the impact of measurement errors from each instrument platform on indices. This study indicates that the nonintegrated indices (e.g., lifted index) derived from AERI retrievals are more accurate than integrated indices (e.g., CAPE). While the AERI retrieval’s vertical resolution can inhibit precise diagnoses of capping inversions, the high-temporal-resolution nature of the AERI profiles overall helps in detecting rapid temporal changes in stability.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

Extension of Complex Refractive Index Measurements to the Near-Infrared for Liquids: Methodology and Uncertainty Analysis

Optical identification of liquid droplets, aerosols, or thin films is important for many applications. While reference spectra are sometimes available for such measurements, they are not always applicable to the observed spectrum or the given sample morphology. Reference spectra for many forms can be modeled, however, if the n/k vectors (real and imaginary refractive indices) are available. In previous work we have reported protocols to determine the n/k vectors for dozens of liquids, primarily in the mid-infrared (MIR) spectral range from 7500 to 400 cm –1 . In this work we extend the spectral range into the near-infrared (NIR) region, demonstrating a method to measure and merge the data sets to create composite n/k data ranging from 10 000 to 400 cm –1 (1.0 to 25 µm) with absorbance fidelity spanning over four orders of magnitude, and vastly improved signal-to-noise in the NIR. The precision of the composite data is evaluated for three different liquids, focusing primarily on the steps for converting the raw absorbance spectra to k values. The variability in both MIR and NIR data as well as in the final n/k vectors is also investigated for several liquids. For typical liquids, the overall variability (reported as 2σ) in the final n and k-vectors is determined to be ∼0.4% and 3%, respectively. Finally, the derived n/k data are used to calculate absorbance spectra for aerosol droplets, showing marginal variability due to the typical measurement errors in the final n/k vectors.

47 OTHER INSTRUMENTATION↗
DOE OSTI2015

Effects of repetitive pulsing on multi-kHz planar laser-induced incandescence imaging in laminar and turbulent flames

Planar laser-induced incandescence (LII) imaging is reported at repetition rates up to 100 kHz using a burst-mode laser system to enable studies of soot formation dynamics in highly turbulent flames. Furthermore, to quantify the accuracy and uncertainty of relative soot volume fraction measurements, the temporal evolution of the LII field in laminar and turbulent flames is examined at various laser operating conditions. Under high-speed repetitive probing, it is found that LII signals are sensitive to changes in soot physical characteristics when operating at high laser fluences within the soot vaporization regime. For these laser conditions, strong planar LII signals are observed at measurement rates up to 100 kHz but are primarily useful for qualitative tracking of soot structure dynamics. However, LII signals collected at lower fluences allow sequential planar measurements of the relative soot volume fraction with a sufficient signal-to-noise ratio at repetition rates of 10–50 kHz. Finally, guidelines for identifying and avoiding the onset of repetitive probe effects in the LII signals are discussed, along with other potential sources of measurement error and uncertainty.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2022

Real-time measurement of parametric influences on the refractive index and length changes in silica optical fibers

In this paper, we present a simple cascaded Fabry-Perot interferometer (FPI) that can be used to measure in real-time the refractive index (RI) and length variation in silica optical fibers caused due to external physical parameters, such as temperature, strain, and radiation. As a proof-of-concept, we experimentally demonstrate real-time monitoring of temperature effects on the RI and length and measure the thermo-optic coefficient (TOC) and thermal expansion coefficient (TEC) by using the cascaded FPI within a temperature range of 21–486°C. The experimental results provide a TEC of 5.53 × 10 −7 /°C and TOC of 4.28 × 10 −6 /°C within the specified temperature range. Such a simple cascaded FPI structure will enable the design of optical sensors to correct for measurement errors by understanding the change in RI and length of optical fiber caused by environment parameters.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2018

Utah FORGE: TEM and Gravity Data

This submission includes a gravity data in text format and as a GIS point shapefile and transient electromagnetic (TEM) raw data. Each text file additionally contains location data (UTM Zone 12, NAD83) and elevation (meters) data for that station. The gravity data shapefile was in part downloaded from PACES, University of Texas at El Paso, http://gis.utep.edu/subpages/GMData.html, and in part collected by the Utah Geological Survey (UGS) as part of the DOE GTO supported Utah FORGE geothermal energy project near Milford, Utah. The PACES data were examined and scrubbed to eliminate any questionable data. A 2.67 g/cm^3 reduction density was used for the Bouguer correction. The attribute table column headers for the gravity data shapefile are explained below. There is also metadata attached to the GIS shapefile. name: the individual gravity station name. HAE: height above ellipsoid [meter] NGVD29: vertical datum for geoid [meter] obs: observed gravity ERRG: gravity measurement error [mGal] IZTC: inner zone terrain correction [mGal] OZTC: outer zone terrain correction [mGal] Gfa: free air gravity gSBGA: Bouguer horizontal slab sCBGA: Complete Bouguer anomaly

15 GEOTHERMAL ENERGY↗
DOE OSTI2018

Tunable Q-Factor Gas-Filled RF Cavity

Fermilab is the main institution to produce the most powerful and wide-spectrum neutrino beam. From that respective, a radiation robust beam diagnostic system is a critical element in order to maintain the quality of the neutrino beam. Within this context, a novel radiation-resistive beam profile monitor based on a gas-filled RF cavity has been proposed. The goal of this measurement is to study a tunable Q-factor RF cavity to determine the accuracy of the RF signal as a function of the quality factor. Specifically, the measurement error of the Q-factor in the RF calibration is investigated. Then, the RF system will be improved to minimize signal error.

43 PARTICLE ACCELERATORS↗
DOE OSTI2014

A BASIS FOR MODIFYING THE TANK 12 COMPOSITE SAMPLING DESIGN

The SRR sampling campaign to obtain residual solids material from the Savannah River Site (SRS) Tank Farm Tank 12 primary vessel resulted in obtaining appreciable material in all 6 planned source samples from the mound strata but only in 5 of the 6 planned source samples from the floor stratum. Consequently, the design of the compositing scheme presented in the Tank 12 Sampling and Analysis Plan, Pavletich (2014a), must be revised. Analytical Development of SRNL statistically evaluated the sampling uncertainty associated with using various compositing arrays and splitting one or more samples for compositing. The variance of the simple mean of composite sample concentrations is a reasonable standard to investigate the impact of the following sampling options. Composite Sample Design Option (a). Assign only 1 source sample from the floor stratum and 1 source sample from each of the mound strata to each of the composite samples. Each source sample contributes material to only 1 composite sample. Two source samples from the floor stratum would not be used. Composite Sample Design Option (b). Assign 2 source samples from the floor stratum and 1 source sample from each of the mound strata to each composite sample. This infers that one source sample from the floor must be used twice, with 2 composite samples sharing material from this particular source sample. All five source samples from the floor would be used. Composite Sample Design Option (c). Assign 3 source samples from the floor stratum and 1 source sample from each of the mound strata to each composite sample. This infers that several of the source samples from the floor stratum must be assigned to more than one composite sample. All 5 source samples from the floor would be used. Using fewer than 12 source samples will increase the sampling variability over that of the Basic Composite Sample Design, Pavletich (2013). Considering the impact to the variance of the simple mean of the composite sample concentrations, the recommendation is to construct each sample composite using four or five source samples. Although the variance using 5 source samples per composite sample (Composite Sample Design Option (c)) was slightly less than the variance using 4 source samples per composite sample (Composite Sample Design Option (b)), there is no practical difference between those variances. This does not consider that the measurement error variance, which is the same for all composite sample design options considered in this report, will further dilute any differences. Composite Sample Design Option (a) had the largest variance for the mean concentration in the three composite samples and should be avoided. These results are consistent with Pavletich (2014b) which utilizes a low elevation and a high elevation mound source sample and two floor source samples for each composite sample. Utilizing the four source samples per composite design, Pavletich (2014b) utilizes aliquots of Floor Sample 4 for two composite samples.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Tools for Enhanced Grid Operation and Optimized PV Penetration Utilizing Highly Distributed Sensor Data.

Increasing number s of PV on distribution systems are creating more grid impacts , but it also provides more opportunities for measurement, sensing, and control of the grid in a distributed fashion. This report demonstrates three software tools for characterizing and controlling distribution feeders by utilizing large numbers of highly distributed current, voltage , and irradiance sensors. Instructions and a user manual is presented for each tool. First, the tool for distribution system secondary circuit parameter estimation is presented. This tool allows studying distribution system parameter estimation accuracy with user-selected active power, reactive power, and voltage measurements and measurement error levels. Second, the tool for multi-objective inverter control is shown. Various PV inverter control strategies can be selected to objectively compare their impact on the feeder. Third, the tool for energy storage for PV ramp rate smoothing is presented. The tool allows the user to select different storage characteristics (power and energy ratings) and control types (local vs. centralized) to study the tradeoffs between state-of-charge (SOC) management and the amount of ramp rate smoothing.

Reno, Matthew J.↗
DOE OSTI2016

Optimal Control of a Surge-Mode WEC in Random Waves

The objective of this project was to develop one or more real-time feedback and feed-forward (MPC) control algorithms for an Oscillating Surge Wave Converter (OSWC) developed by RME called SurgeWEC™ that leverages recent innovations in wave energy converter (WEC) control theory to maximize power production in random wave environments. The control algorithms synthesized innovations in dynamic programming and nonlinear wave dynamics using anticipatory wave sensors and localized sensor measurements; e.g. position and velocity of the WEC Power Take Off (PTO), with predictive wave forecasting data. The result was an advanced control system that uses feedback or feed-forward data from an array of sensor channels comprised of both localized and deployed sensors fused into a single decision process that optimally compensates for uncertainties in the system dynamics, wave forecasts, and sensor measurement errors.

16 TIDAL AND WAVE POWER↗
DOE OSTI2017

29 mm Diameter Target Test Report

After numerous delays, the test of the 29 mm diameter target was conducted on 8/18/2017. The complete target design report, dated 8/15/2016, is reproduced below for completeness. This describes in detail the 10 disk target with varying thickness disks. The report presents and discusses the test results. In brief summary, there appears to have been multiple instrumentation errors. Measured temperatures, pressures and IR camera window temperature measurement are all suspect. All tests were done at 35 MeV, with 171 μA current, or 6 kW of beam power.

43 PARTICLE ACCELERATORS↗