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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 1,585 records · Page 88
All sourcesNASA NTRSDOE OSTI
DOE OSTI2013

Dixie Valley Engineered Geothermal System Exploration Methodology Project, Baseline Conceptual Model Report

The Engineered Geothermal System (EGS) Exploration Methodology Project is developing an exploration approach for EGS through the integration of geoscientific data. The Project chose the Dixie Valley Geothermal System in Nevada as a field laboratory site for methodlogy calibration purposes because, in the public domain, it is a highly characterized geothermal systems in the Basin and Range with a considerable amount of geoscience and most importantly, well data. This Baseline Conceptual Model report summarizes the results of the first three project tasks (1) collect and assess the existing public domain geoscience data, (2) design and populate a GIS database, and (3) develop a baseline (existing data) geothermal conceptual model, evaluate geostatistical relationships, and generate baseline, coupled EGS favorability/trust maps from +1km above sea level (asl) to -4km asl for the Calibration Area (Dixie Valley Geothermal Wellfield) to identify EGS drilling targets at a scale of 5km x 5km. It presents (1) an assessment of the readily available public domain data and some proprietary data provided by Terra-Gen Power, LLC, (2) a re-interpretation of these data as required, (3) an exploratory geostatistical data analysis, (4) the baseline geothermal conceptual model, and (5) the EGS favorability/trust mapping. The conceptual model presented applies to both the hydrothermal system and EGS in the Dixie Valley region.

15 GEOTHERMAL ENERGY↗
DOE OSTI2021

Exploring the physics of cesium lead halide perovskite quantum dots via Bayesian inference of the photoluminescence spectra in automated experiment

The unique optoelectronic properties of metal halide perovskite quantum dots (QDs) make them promising candidates for applications in light-emitting diodes (LEDs), scintillators, and other photonic devices. The automated micropipetting synthesis platform equipped with an optical reader enables the opportunity for high throughput synthesis and photoluminescent (PL) characterization of metal halide perovskite QDs for the first time. Here, we explore the compositional dependence of the PL behavior and stability of the combinatorial library of cesium lead halide (CsPbX 3 ) perovskites QDs via the automated platform. To study the stability of synthesized QDs in the binary and ternary configurations, we study the time-dependent PL properties using previously developed machine learning analysis. Additionally, to systematically explore the PL behavior in the ternary CsPbX 3 QDs system, we introduce the Bayesian inference framework that allows the probabilistic fit of multiple models to the PL data and establishes both optimal model and model parameter robustly. Furthermore, these behaviors can be used as a control parameter for the navigation of the multidimensional compositional spaces in automated synthesis. Furthermore, this analysis shows the nonuniformity of the PL peak behavior in the ternary CsPbX 3 QDs system. Further, the analysis confirms narrow size distribution and good quality of CsPbBr 3 QDs alloyed with low concentrations of iodide and chloride. We note that Bayesian Inference fit parameters can be further used as a control signal for navigation of the chemical spaces in automated synthesis.

36 MATERIALS SCIENCE↗
DOE OSTI2017

People and water: Exploring the social-ecological condition of watersheds of the United States

A recent paradigm shift from purely biophysical towards social-ecological assessment of watersheds has been proposed to understand, monitor, and manipulate the myriad interactions between human well-being and the ecosystem services that watersheds provide. However, large-scale, quantitative studies in this endeavour remain limited. We utilised two newly developed ‘big-data’ sets—the Index of Watershed Integrity (IWI) and the Human Well-Being Index (HWBI)—to explore the social-ecological condition of watersheds throughout the conterminous U.S., and identified environmental and socio-economic influences on watershed integrity and human well-being. Mean county IWI was highly associated with ecoregion, industry-dependence, and state, in a spatially-explicit regression model (R 2 = 0.77, Ρ < 0.001), whereas HWBI was not (R 2 = 0.31, P < 0.001). HWBI is likely influenced by factors not explored here, such as governance structure and formal and informal organisations and institutions. ‘Win-win’ situations in which both IWI and HWBI were above the 75th percentile were observed in much of Utah, Colorado, and New Hampshire, and lessons from governance that has resulted in desirable outcomes might be learnt from here. Eastern Kentucky and West Virginia, along with large parts of the desert southwest, had intact watersheds but low HWBI, representing areas worthy of further investigation of how ecosystem services might be utilised to improve well-being. The Temperate Prairies and Central USA Plains had widespread areas of low IWI but high HWBI, likely a result of historic exploitation of watershed resources to improve well-being, particularly in farming-dependent counties. The lower Mississippi Valley had low IWI and HWBI, which is likely related to historical (temporal) and upstream (spatial) impacts on both watershed integrity and well-being. The results emphasise the importance of considering spatial and temporal trade-offs when utilising the ecosystem services provided by watersheds to improve human well-being.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2020

Gamma-ray spectrometry as a tool for exploring archaeological nuclear facilities: a case study from the Nevada Test Site Nuclear Rocket Development Station

Since its first demonstration in the early 2000s, the exploration of gamma-ray spectrometry (GRS) applications as a geophysical tool in archaeology remains nascent. While intentional neutron activation, which requires a gamma-ray analysis, has seen increasing use as a geoforensics technique in archaeology, little or no research has been published concerning the possibility of GRS as an industrial archaeological tool for use in exploring nuclear sites or facilities where neutron activation and surface contamination may have already occurred. Consequently, the use of GRS as a geophysical tool for the archaeological investigation of abandoned or decommissioned nuclear facilities is proposed, demonstrated, and discussed using a case study from the Nevada Test Site Nuclear Rocket Development Station.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2023

ParFlow Sand Tank: A tool for groundwater exploration

The ParFlow Sand Tank model is an open source application designed to allow users to interactively simulate and visualize groundwater movement through the subsurface. The app is designed for both research and education; teaching hydrogeology concepts and making it easy explore and run sophisticated groundwater simulations. Our goal is to support increased accessibility and usability of research grade hydrology tools for research and teaching. The Sand Tank application simulates groundwater and surface water fluxes as well as contaminant transport in real time using the integrated physical hydrology model ParFlow (Kollet & Maxwell, 2006; Maxwell & Miller, 2005; Osei-Kuffuor et al., 2014) and the particle tracking code EcoSlim (Maxwell et al., 2019). ParFlow is a numerical hydrology model that simulates spatially distributed groundwater and surface water flow. It is a well established research tool with more than 90 publications documenting its development use to advance our understanding of groundwater dynamics and groundwater surface water interactions from the hillslope to the continental scale e.g. (Condon et al., 2020; Condon & Maxwell, 2019; Maxwell & Condon, 2016). It is designed for efficient parallel computation and has been run on many platforms spanning from laptops to supercomputers. However, one of the challenges of ParFlow is that it requires significant training and hydrologic expertise to develop simulations. The Sand Tank application makes this model accessible to anyone for education and exploration. Our application uses ParFlow for its simulation backend and ParaView for the data loading and processing. The communication infrastructure relies on the ParaViewWeb framework. We use model templates deployed in Docker images to setup the Sand Tank framework. Users can build the application locally or interact with it through our web deployment. When interacting with a template users can interactively change model parameters like subsurface processes or pump/inject water into the subsurface and watch the system respond to their changes in real time as the simulation runs. Additionally, our template setup will allow more advanced users to build custom templates of increasing complexity for both research and educational purposes.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

TX$^2$: Transformer eXplainability and eXploration

The Transformer eXplainability and eXploration (Martindale & Stewart, 2021), or TX 2 software package, is a library designed for artificial intelligence researchers to better understand the performance of transformer models (Vaswani et al., 2017) used for sequence classification. The tool is capable of integrating with a trained transformer model and a dataset split into training and testing populations to produce an ipywidget (Project Jupyter Contributors, 2021) dashboard with a number of visualizations to understand model performance with an emphasis on explainability and interpretability. The TX 2 package is primarily intended to integrate into a workflow centered around Jupyter Notebooks (Kluyver et al., 2016), and currently assumes the use of PyTorch (Paszke et al., 2019) and Hugging Face transformers library (Wolf et al., 2020). The dashboard includes visualization and data exploration features to aid researchers, including an interactive UMAP embedding graph (McInnes et al., 2018) to understand classification clusters, a word salience map that can be updated as researchers alter textual entries in near real time, a set of tools to understand word frequency and importance based on the clusters in the UMAP embedding graph, and a set of traditional confusion matrix analysis tools.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2012

Observed physical processes in mechanical tests of PBX9501 and recomendations for experiments to explore a possible plasticity/damage threshold

This memo discusses observations that have been made in regards to a series of monotonic and cyclic uniaxial experiments performed on PBX9501 by Darla Thompson under Enhanced Surveilance Campaign support. These observations discussed in Section Cyclic compression observations strongly suggest the presence of viscoelastic, plastic, and damage phenomena in the mechanical response of the material. In Secton Uniaxial data analysis and observations methods are discussed for separating out the viscoelastic effects. A crude application of those methods suggests the possibility of a critical stress below which plasticity and damage may be negligible. The threshold should be explored because if it exists it will be an important feature of any constitutive model. Additionally, if the threshold exists then modifications of experimental methods may be feasible which could potentially simplify future experiments or provide higher quality data from those experiments. A set of experiments to explore the threshold stress are proposed in Section Exploratory tests program for identifying threshold stress.

36 MATERIALS SCIENCE↗
DOE OSTI2012

Exploration of Optimization Options for Increasing Performance of a GPU Implementation of a Three-dimensional Bilateral Filter

This report explores using GPUs as a platform for performing high performance medical image data processing, specifically smoothing using a 3D bilateral filter, which performs anisotropic, edge-preserving smoothing. The algorithm consists of a running a specialized 3D convolution kernel over a source volume to produce an output volume. Overall, our objective is to understand what algorithmic design choices and configuration options lead to optimal performance of this algorithm on the GPU. We explore the performance impact of using different memory access patterns, of using different types of device/on-chip memories, of using strictly aligned and unaligned memory, and of varying the size/shape of thread blocks. Our results reveal optimal configuration parameters for our algorithm when executed sample 3D medical data set, and show performance gains ranging from 30x to over 200x as compared to a single-threaded CPU implementation.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2013

Exploration of the Phase Field Framework Marmot to Include Anisotropic Grain Boundaries with Molecular Dynamics [Thesis]

Using molecular dynamic (MD) calculations, meso-scale phase field simulations behave differently by including anisotropic grain boundary energy in the model for transient energy minimization in uranium-dioxide. As a preliminary step, MD will be used to find face centered cubic (FCC) copper grain boundary energies and to explore its anisotropic behavior in phase field simulations. MARMOT is a C++ code that uses object-oriented programming to implement the Allen-Cahn and Cahn-Hilliard equations for phase field modeling. MARMOT uses constants for mobility and grain boundary energy for the entire domain of the simulation. For MARMOT to reach its full capability, these constants need to vary within the domain. This paper explores the expansion of MARMOT to include an anisotropic view of grain boundary energy in transient phase field simulations.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2015

Exploring Alternative Non-contact temperature measurements for 99 Mo production facility NorthStar FY14 Activity 5, Deliverable 2

We have conducted an experiment to explore an alternative non-contact method of measuring the Inconel target window temperature. This experiment involves using a standard color camera to observe the visible light emitted from the Inconel target window at high heat in order to estimate the window temperature. The safety limit to prevent target window failure is 700 °C and therefore we need a reliable and accurate method of measuring temperature especially in the range of 600 °C to 700 °C if it is to replace the IR camera. In this temperature range the window will emit a significant amount of black body radiation within the visible range and hence the idea of using a color camera. The goal is to see if the shift in window color (determined by the RBG pixel values of the camera) as the target window is heated to 700 °C can be calibrated to the temperature.The reasons for exploring this as an alternative to an IR are camera are: significant cost reduction and potentially less complicated to calibrate.

42 ENGINEERING↗
DOE OSTI2015

Proceedings of RIKEN BNL Research Center Workshop: Theory and Modeling for the Beam Energy Scan: From Exploration to Discovery (Volume 121)

The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory has concluded phase I of its Beam Energy Scan (BES) program. The goal of the RHIC BES program is to explore the phase diagram of strongly interacting matter at high baryonic densities and search for the QCD critical point by performing systematic scans at lower beam energies. Results from the RHIC BES I program are intriguing. There indeed seem to be several signals suggesting a softening of the equation of state, which may result from a first-order transition, as well as possible indications of a critical point. In light of these intriguing results, several accelerator and detector upgrades have been planned to conduct the phase II of the RHIC BES during the period 2017-2020. The goal of the RHIC BES II is discovery of the QCD critical point by performing high luminosity scans within the interesting beam energy range revealed through explorations at RHIC BES I. Past experience has proven that even qualitative understanding of the physics encoded within the RHIC experimental data requires substantial theoretical input based on QCD calculations as well as detailed, quantitative modeling of the medium created at the RHIC. However, the coordinated theoretical and modeling efforts necessary for comprehensive understanding of the RHIC BES data is presently lacking. The purpose of this workshop was to gather a small group of expert theorists, phenomenologists and experimentalists to identify the necessary theoretical and modeling developments required for RHIC BES, to delineate a clear path towards extracting concrete physics utilizing the RHIC BES data, and to kick-start collaborations among theorists, phenomenologists and experimentalists to ensure that the necessary theoretical and modeling developments can be achieved before the start of the RHIC BES II experimental program.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2014

Exploring the Utilization of Complex Algal Communities to Address Algal Pond Crash and Increase Annual Biomass Production for Algal Biofuels

This white paper briefly reviews the research literature exploring complex algal communities as a means of increasing algal biomass production via increased tolerance, resilience, and resistance to a variety of abiotic and biotic perturbations occurring within harvesting timescales. This paper identifies what data are available and whether more research utilizing complex communities is needed to explore the potential of complex algal community stability (CACS) approach as a plausible means to increase biomass yields regardless of ecological context and resulting in decreased algal-based fuel prices by reducing operations costs. By reviewing the literature for what we do and do not know, in terms of CACS methodologies, this report will provide guidance for future research addressing pond crash phenomena.

09 BIOMASS FUELS↗
DOE OSTI2015

Resolving and Measuring Diffusion in Complex Interfaces: Exploring New Capabilities

This exploratory LDRD targeted the use of a new high resolution spectroscopic diffusion capabilities developed at Sandia to resolve transport processes at interfaces in heterogeneous polymer materials. In particular, the combination of high resolution magic angle spinning (HRMAS) nuclear magnetic resonance (NMR) spectroscopy with pulsed field gradient (PFG) diffusion experiments were used to directly explore interface diffusion within heterogeneous polymer composites, including measuring diffusion for individual chemical species in multi-component mixtures. Several different types of heterogeneous polymer systems were studied using these HRMAS NMR diffusion capabilities to probe the resolution limitations, determine the spatial length scales involved, and explore the general applicability to specific heterogeneous systems. The investigations pursued included a) the direct measurement of the diffusion for poly(dimethyl siloxane) polymer (PDMS) on nano-porous materials, b) measurement of penetrant diffusion in additive manufactures (3D printed) processed PDMS composites, and c) the measurement of diffusion in swollen polymers/penetrant mixtures within nano-confined aluminum oxide membranes. The NMR diffusion results obtained were encouraging and allowed for an improved understanding of diffusion and transport processes at the molecular level, while at the same time demonstrating that the spatial heterogeneity that can be resolved using HRMAS NMR PFG diffusion experiment must be larger than ~μm length scales, expect for polymer transport within nanoporous carbons where additional chemical resolution improves the resolvable heterogeneous length scale to hundreds of nm.

36 MATERIALS SCIENCE↗
DOE OSTI2015

Conducting a 3D Converted Shear Wave Project to Reduce Exploration Risk at Wister, CA

Ormat sited 2 full-size exploration wells based on 3D seismic interpretation of fractures, prior drilling results, and temperature anomaly. The wells indicated commercial temperatures (>300 F), but almost no permeability, despite one of the wells being drilled within 820 ft of an older exploration well with reported indications of permeability. Following completion of the second well in 2012, Ormat undertook a lengthy program to 1) evaluate the lack of observed permeability, 2) estimate the likelihood of finding permeability with additional drilling, and 3) estimate resource size based on an anticipated extent of permeability.

15 GEOTHERMAL ENERGY↗
DOE OSTI2015

A Technical and Economic Optimization Approach to Exploring Offshore Renewable Energy Development in Hawaii

This study was conducted with the support of the U.S. Department of Energy’s (DOE’s) Wind and Water Power Technologies Office (WWPTO) as part of ongoing efforts to minimize key risks and reduce the cost and time associated with permitting and deploying ocean renewable energy. The focus of the study was to discuss a possible approach to exploring scenarios for ocean renewable energy development in Hawaii that attempts to optimize future development based on technical, economic, and policy criteria. The goal of the study was not to identify potentially suitable or feasible locations for development, but to discuss how such an approach may be developed for a given offshore area. Hawaii was selected for this case study due to the complex nature of the energy climate there and DOE’s ongoing involvement to support marine spatial planning for the West Coast. Primary objectives of the study included 1) discussing the political and economic context for ocean renewable energy development in Hawaii, especially with respect to how inter-island transmission may affect the future of renewable energy development in Hawaii; 2) applying a Geographic Information System (GIS) approach that has been used to assess the technical suitability of offshore renewable energy technologies in Washington, Oregon, and California, to Hawaii’s offshore environment; and 3) formulate a mathematical model for exploring scenarios for ocean renewable energy development in Hawaii that seeks to optimize technical and economic suitability within the context of Hawaii’s existing energy policy and planning.

58 GEOSCIENCES↗
DOE OSTI2016

Preliminary Exploration of Encounter During Transit Across Southern Africa

Los Alamos National Laboratory (LANL) is utilizing the Probability Effectiveness Methodology (PEM) tools, particularly the Pathway Analysis, Threat Response and Interdiction Options Tool (PATRIOT) to support the DNDO Architecture and Planning Directorate’s (APD) development of a multi-region terrorist risk assessment tool. The effort is divided into three stages. The first stage is an exploration of what can be done with PATRIOT essentially as is, to characterize encounter rate during transit across a single selected region. The second stage is to develop, condition, and implement required modifications to the data and conduct analysis to generate a well-founded assessment of the transit reliability across that selected region, and to identify any issues in the process. The final stage is to extend the work to a full multi-region global model. This document provides the results of the first stage, namely preliminary explorations with PATRIOT to assess the transit reliability across the region of southern Africa.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2015

Understanding of catalysis on early transition metal oxide-based catalysts through exploration of surface structure and chemistry during catalysis using in-situ approaches

Two main categories of heterogeneous catalysts are metal and metal oxide which catalyze 80% chemical reactions at solid-gas and solid-liquid interfaces. Metal oxide catalysts are much more complicated than metal catalysts. The reason is that the cations of the metal atoms could exhibit a few different oxidation states on surface of the same catalyst particle such as Co 3 O 4 or change of their oxidation states under different reactive environments. For a metal catalyst, there is only one oxidation state typically. In addition, surface of a metal oxide can be terminated with multiple surface functionalities including O atoms with different binding configurations and OH group. For metal, only metal atoms are exposed typically. Obviously, the complication of surface chemistry and structure of a metal oxide makes studies of surface of an oxide catalyst very challenging. Due to the complication of surface of a meal oxide, the electronic and geometric structures of surface of a metal oxide and the exposed species have received enormous attention since oxide catalysts catalyze at least 1/3 chemical reactions in chemical and energy industries. Understanding of catalytic reactions on early transition metal oxide-based catalysts is fundamentally intriguing and of great practical interest in energy- and environment-related catalysis. Exploration of surface chemistry of oxide-based catalysts at molecular level during catalysis has remained challenging though it is critical in deeply understanding catalysis on oxide-based catalysts and developing oxide-based catalysts with high activity and selectivity. Thus, the overall objective of this project is to explore surface chemistry and structure of early transition metal oxide-based catalysts through in-situ characterization of surface of catalysts, measurements of catalytic performances, and then build an intrinsic correlation of surface chemistry and structure with their catalytic performances in a few important catalytic reactions, and essentially fundamentally understand catalytic mechanism. Furthermore, this correlation will guide the design of catalysts with high activity and selectivity.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2017

Footprint of Sandia's August 15 2016 Informal Idea Exploration Session on "Towards an Engineering and Applied Science of Research".

On August 15, 2016, Sandia hosted a visit by Professor Venkatesh Narayanamurti. Prof Narayanamurti (Benjamin Peirce Research Professor of Technology and Public Policy at Harvard, Board Member of the Belfer Center for Science and International Affairs, former Dean of the School of Engineering and Applied Science at Harvard, former Dean of Engineering at UC Santa Barbara, and former Vice President of Division 1000 at Sandia). During the visit, a small, informal, all-day idea exploration session on "Towards an Engineering and Applied Science of Research" was conducted. This document is a brief synopsis or "footprint" of the presentations and discussions at this Idea Exploration Session. The intent of this document is to stimulate further discussion about pathways Sandia can take to improve its Research practices.

42 ENGINEERING↗