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NASA NTRS2004

Validation and Analysis of SRTM and VCL Data Over Tropical Volcanoes

The focus of our investigation was on the application of digital topographic data in conducting first-order volcanological and structural studies of tropical volcanoes, focusing on the Java, the Philippines and the Galapagos Islands. Kilauea volcano, Hawaii, served as our test site for SRTM data validation. Volcanoes in humid tropical environments are frequently cloud covered, typically densely vegetated and erode rapidly, so that it was expected that new insights into the styles of eruption of these volcanoes could be obtained from analysis of topographic data. For instance, in certain parts of the world, such as Indonesia, even the regional structural context of volcanic centers is poorly known, and the distribution of volcanic products (e.g., lava flows, pyroclastic flows, and lahars) are not well mapped. SRTM and Vegetation Canopy Lidar (VCL) data were expected to provide new information on these volcanoes. Due to the cancellation of the VCL mission, we did not conduct any lidar studies during the duration of this project. Digital elevation models (DEMs) such as those collected by SRTM provide quantitative information about the time-integrated typical activity on a volcano and allow an assessment of the spatial and temporal contributions of various constructional and destructional processes to each volcano's present morphology. For basaltic volcanoes, P_c?w!m-d and Garbed (2000) have shown that gradual slopes (less than 5 deg.) occur where lava and tephra pond within calderas or in the saddles between adjacent volcanoes, as well as where lava deltas coalesce to form coastal plains. Vent concentration zones (axes of rift zones) have slopes ranging from 10 deg. to 12 deg. Differential vertical growth rates between vent concentration zones and adjacent mostly-lava flanks produce steep constructional slopes up to 40". The steepest slopes (locally approaching 90 deg.) are produced by fluvial erosion, caldera collapse, faulting, and catastrophic avalanches, all of which are usually identifiable. Due to the delay in the release of the SRTM data following the February 2000 flight, a significant part of our effort was devoted to the analog studies of the SRTM topographic data using topographic data from airborne interferometric radars. As part of the original SRTM Science Team, we proposed four study sites (Kilauea, Hawaii; Mt. Pinatubo, Philippines; Cerro Am1 and Femandina volcanoes, Galapagos Islands; and Tengger caldera, Java) where we could conduct detailed geologic studies to evaluate the uses of SRTM data for the analysis of lava flows, lahars, erosion of ash deposits, and an evaluation of the structural setting of the volcanoes. Only near the end of this project was one of these SRTM Science Team products (Luzon Island, the Philippines) released to the community, and we only had limited time to work on these data.

Mouginis-Mark, Peter J.↗

NASA NTRS2005

Synthesis and Near IR Photoluminescence of Os(II) Bis(2,2'-bipyridine) (3,8-Diarylethynyl-1,10-phemanthroline) Complexes: Anomalous Behavior of the 3,8-Dinitrophenylethynyl-substituted Homologue

A large bathochromic shift (50 nm) and emission in the near infrared is observed by attaching arylethynyl groups at the 3,8-positions of the 1,10-phenanthroline ligand (phen) of [Os(bipy)2(phen)]2+ (where bipy = 2,2'-bipyridine). Thus [Os(bipy)2(3,8-di-4-methoxyphenylethynyl-1,10-phenathroline)]2+ emits at 795 nm, while [Os(bipy)2(3,8-diphenylethynyl-1,10-phenanthroline)]2+ emits at 815 nm. According to this trend it would have been expected that [Os(bipy)2(3,8-di-4-nitrophenylethynyl-1,10-phenathroline)]2+ emits farther in the near infrared. Nevertheless, this complex is not photoluminescent because of intramolecular electron transfer quenching of the MLCT excited state by the nitroaromatic group. These results set structural and redox potential standards in the design of near infrared emitters based on [Os(bipy)2(phen)]2+ type complexes.

Yang, Jinhua↗

NASA NTRS2024

Mount Etna as A Terrestrial Laboratory to Investigate Recent Volcanic Activity on Venus By Future Missions: A Comparison With Idunn Mons, Venus

The recently selected missions to Venus have opened a new era for the exploration of this planet. These missions will provide information about the chemistry of the atmosphere, the geomorphology, local-to-regional surface composition, and the rheology of the interior. One key scientific question to be addressed by these future missions is whether Venus remains volcanically active, and if so, how its volcanism is currently evolving. Hence, it is fundamental to analyze appropriate terrestrial analog sites for the study of possibly active volcanism on Venus. To this regard, we propose Mount Etna - one of the most active and monitored volcanoes on Earth - as a suitable terrestrial laboratory for remote and in-situ investigations to be performed by future missions to Venus. Being characterized by both effusive and explosive volcanic products, Mount Etna offers the opportunity to analyze multiple eruptive styles, both monitoring active volcanism and identifying the possible occurrence of pyroclastic activity on Venus. We directly compare Mount Etna with Idunn Mons, one of the most promising potentially active volcanoes of Venus. Despite the two structures show a different topography, they also show some interesting points of comparison, and in particular: a) comparable morpho-structural setting, since both volcanoes interact with a rift zone, and b) morphologically similar volcanic fields around both Mount Etna and Idunn Mons. Given its ease of access, we also propose Mount Etna as an analog site for laboratory spectroscopic studies to identify the signatures of unaltered volcanic deposits on Venus.

P D DIncecco↗

DOE OSTI2020

APPLICATION OF MATURITY MODELS FOR EVALUATING CYBERSECURITY PROGRAMS AT NUCLEAR AND RADIOLOGICAL FACILITIES

Maturity models can be used to provide government agencies, industry associations, and organizations operating nuclear facilities with the ability to quickly evaluate the maturity of their cybersecurity programs and identify areas to prioritize for improvement. The Cybersecurity Capability Maturity Model (C2M2) was developed by the U.S. Department of Energy to allow organizations in the energy sector to evaluate the programmatic capabilities of their cybersecurity programs in a consistent manner, communicate programmatic maturity information, prioritize cybersecurity investments in targeted areas of concern, and track how the maturity of their cybersecurity program evolves over time. The C2M2 is designed for use by any critical infrastructure organization regardless of ownership, structure, or size. The C2M2 can be easily fine-tuned to access the maturity of nuclear cybersecurity programs and their application at individual facilities. Built on a foundation of existing cybersecurity standards, frameworks, programs, and initiatives, the model features 10 security domains. Performance in each security domain is characterized using a structured set of cybersecurity practices that represent activities an organization can perform to improve cybersecurity in their domain. Each practice can be quickly evaluated as being either fully, largely, partially, or not implemented. Once practices are evaluated for each security domain, the model defines four maturity indicator levels that apply independently to each domain in the model. To earn a maturity level in a given domain, an organization must adequately perform all the practices for that maturity level and its predecessor level(s). A small assessment team can conduct a C2M2 assessment in a single day. A screening version of the C2M2 allows an initial look at the maturity of nuclear cybersecurity programs that could be completed in under an hour.

Cyber security, Nuclear security, maturity model↗

DOE OSTI2022

Advancing Geophysical Techniques to Image a Stratigraphic Hydrothermal Resource

Sedimentary-hosted geothermal energy systems are permeable structural, structural-stratigraphic, and/or stratigraphic horizons with sufficient temperature for direct use and/or electricity generation. Sedimentary-hosted (i.e., stratigraphic) geothermal reservoirs may be present in multiple locations across the central and eastern Great Basin of the USA, thereby constituting a potentially large base of untapped, economically accessible energy resources. Sandia National Laboratories has partnered with a multi disciplinary group of collaborators to evaluate a stratigraphic system in Steptoe Valley, Nevada using both established and novel geophysical imaging techniques. The goal of this study is to inform an optimized strategy for subsequent exploration and development of this resource and analogous ones. Building from prior Nevada Play Fairway Analysis (PFA), this team is primarily 1) collecting additional geophysical data, 2) employing novel joint geophysical inversion/modeling techniques to update existing 3D geologic models, and 3) integrating the geophysical results to produce a working, geologically constrained thermo-hydrological reservoir model. Prior PFA work highlights Steptoe Valley as a favorable resource basin that likely has both sedimentary and hydrothermal characteristics. However, there remains significant uncertainty on the nature and architecture of the resource(s) at depth, which increases the risk in exploratory drilling. Newly acquired gravity, magnetic, magnetotelluric, and controlled-source electromagnetic data products, in conjunction with new and preexisting geoscientific measurements and observations, are being integrated and evaluated for efficacy in understanding stratigraphic geothermal resources and mitigating exploration risk. Furthermore, the influence of hydrothermal activity on sedimentary-hosted reservoirs in favorable structural settings, and whether fault-controlled systems may locally enhance temperature and permeability in some deep stratigraphic reservoirs, will also be evaluated.

Geothermal, Sedimentary Heat, Geophysics, Seismic,↗

DOE OSTI2023

The Mitigation Hierarchy

The mitigation hierarchy is a widely used framework to inform conservation decisions. The hierarchy offers a structured set of steps for how projects can lessen negative impacts or lead to an increase in biodiversity. In its simplest form, the mitigation hierarchy includes three stages: (1) avoid creating impacts from the outset, (2) minimize the impacts that cannot be avoided, and (3) compensate for or offset the impacts that cannot be minimized. Proper application of the hierarchy should decrease impacts of the project over time, such that most of the impact is alleviated through avoidance, leaving a modest amount remaining to minimize, and only a residual to compensate. In practice, avoidance should be prioritized and can be a cost-effective means of mitigation. Whereas compensation should be considered the lowest priority and should only be applied in situations in which the previous mitigation steps were unable to fully alleviate undesirable impacts.

biodiversity↗

DOE OSTI2023

La Jerarquia de Mitigacion (Spanish)

biodiversity↗

DOE OSTI2023

A VOI Web Application for Distinct Geothermal Domains: Statistical Evaluation of Different Data Types within the Great Basin

The Great Basin region contains different domains that have different structural and hydrothermal flow patterns. Depending on the characteristics of these patterns, certain data types may be more successful at detecting hidden geothermal resources. In this paper, we quantitatively evaluate if certain data types are more successful in certain domains. Given different aquifer, strain and structural conditions, we explore which data types statistically reveal positively labeled geothermal sites. We utilize value of information (VOI) metrics to help quantify the reliability of data types to discriminate against "positive" and "negative" labeled geothermal sites. We also evaluate how kernel density estimation can help generalize the statistics that inform VOI, which is necessary given the limited data in geothermal exploration. Except for the Carbonate Aquifer, the highest ranking of the Vimperfect is the Local Structural Setting. Next, the slip and dilation tendency is first for Carbonate Aquifer and second for Central Nevada Seismic Belt and Western Great Basin. For the Carbonate Aquifer, heat flow is has the lowest Vimperfect value compared to the other three domains, which is consistent with the understanding of how heat flow measurements are masked by regional groundwater flow.

Bayesian analysis↗

DOE OSTI2023

A Level Set Model for Structured Mesh Representation of Fibrous Preforms used in Composites Manufacturing

Here, a model for implicit representation of fibrous and woven preforms used for composites manufacturing is described. The method is based on a level set function defined on a structured mesh to implicitly capture the complex fiber and weave geometries. Since most software packages used to model woven preforms are based on unstructured mesh, a numerical model for transforming a discretized surface to a structured mesh representation and vice-a-versa is presented. Specific emphasis is on scalable computation of a level set function for large and complex 3D woven structures from a triangulated surface of the smallest unit (yarn). The model is applied to capture a periodic 3D layered 5-harness satin (5HS) weave geometry on a structured mesh. Geometric transformations needed to efficiently compute the level set function for the 3D structure on a high resolution mesh are described. Effects of mesh resolution on the geometric features such as number of resolved fibers, effective fiber size, and the surface area to volume ratio of the iso-surface are analyzed. Using the distance property of the level set function, an approach to evaluate the structure function resulting from transient evolving topology representing densification due to matrix phase depositions is also presented. The approach captures transition of the geometric characteristic from fiber governed at early stages of densification to yarn governed at the terminal stage.

36 MATERIALS SCIENCE↗

NASA NTRS1991

Assessing damping uncertainty in space structures with fuzzy sets

NASA has been interested in the development of methods for evaluating the predictive accuracy of structural dynamic models. This interest stems from the use of mathematical models in evaluating the structural integrity of all spacecraft prior to flight. Space structures are often too large and too weak to be tested fully assembled in a ground test lab. The predictive accuracy of a model depends on the nature and extent of its experimental verification. The further the test conditions depart from in-service conditions, the less accurate the model will be. Structural damping is known to be one source of uncertainty in models. The uncertainty in damping is explored in order to evaluate the accuracy of dynamic models. A simple mass-spring-dashpot system is used to illustrate a comparison among three methods for propagating uncertainty in structural dynamics models: the First Order Method, the Numerical Simulation Method, and the Fuzzy Set Method. The Fuzzy Set Method is shown to bound the range of possible responses and thus to provide a valuable limiting check on the First Order Method near resonant conditions. Fuzzy Methods are a relative inexpensive alternative to numerical simulation.

Ross, Timothy J.↗

NASA NTRS2010

TPSAS-NF1676L-10980-DND

We plan to perform the following sets of computations on unadapted (fixed) grids: 1) Structured RANS set 1 (Code: CFL3D, Grid: Str-OnetoOne-A-v1 (supplied by HiLiftPW-1 committee), Turbulence model: Spalart-Allmaras), 2) Structured RANS set 2 (Code: CFL3D, Grid: Str-OnetoOne-A-v1 (supplied by HiLiftPW-1 committee), Turbulence model: Menter SST), 3) Structured RANS set 3 (time permitting) (Code: CFL3D, Grid: Str-OnetoOne-B-v1 (supplied by HiLiftPW-1 committee), Turbulence model: Menter SST), 4) Unstructured RANS set 1 (Code: FUN3D, Grid: Unst-Mixed-FromTet-Nodecentered-A-v1 (supplied by HiLiftPW-1 committee), Turbulence model: Spalart-Allmaras), and 5) Unstructured RANS set 2 (time permitting) (Code: FUN3D, Grid: Unst-Hex-FromOnetoOne-A-v1 (supplied by HiLiftPW-1 committee), Turbulence model: Spalart-Allmaras),. Optional case 3 is not being computed. CFL3D is a structured upwind-biased cell-centered RANS code,1 and FUN3D is an unstructured upwind-biased node-centered RANS code

Elizabeth M Lee-Rausch↗

NASA NTRS2010

TPSAS-NF1676L-10454-DND

C L Rumsey↗

NASA NTRS1977

Approximate method for calculating free vibrations of a large-wind-turbine tower structure

A set of ordinary differential equations were derived for a simplified structural dynamic lumped-mass model of a typical large-wind-turbine tower structure. Dunkerley's equation was used to arrive at a solution for the fundamental natural frequencies of the tower in bending and torsion. The ERDA-NASA 100-kW wind turbine tower structure was modeled, and the fundamental frequencies were determined by the simplified method described. The approximate fundamental natural frequencies for the tower agree within 18 percent with test data and predictions analyzed.

Das, S. C.↗

NASA NTRS1993

Report on the test set-up for the structural testing of the Airmass Sunburst Ultralight Aircraft

This report reviews the test set-up and procedure for the structural testing of the Airmass Sunburst Ultralight Aircraft. In general aviation today, there is a growing need for more stringent design criteria for ultralight aircraft. Unlike most general aviation aircraft, the ultralight lacks sufficient design criteria and more importantly it lacks sufficient certification enforcement. The Airmass Sunburst ultralight that is currently being tested is responsible for over a dozen deaths. It is believed that had there been a more stringent criteria and certification process, this might have been prevented. Our attempt is to show that the failing loads of the aircraft in question are so far below that of the current design criteria, that the laws need to be changed.

Zimmerman, William↗

NASA NTRS1993

Structural mapping of Maxwell Montes

Four sets of structures were mapped in the western and southern portions of Maxwell Montes. An early north-trending set of penetrative lineaments is cut by dominant, spaced ridges and paired valleys that trend northwest. To the south the ridges and valleys splay and graben form in the valleys. The spaced ridges and graben are cut by northeast-trending graben. The northwest-trending graben formed synchronously with or slightly later than the spaced ridges. Formation of the northeast-trending graben may have overlapped with that of the northwest-trending graben, but occurred in a spatially distinct area (regions of 2 deg slope). Graben formation, with northwest-southeast extension, may be related to gravity-sliding. Individually and collectively these structures are too small to support the immense topography of Maxwell, and are interpreted as parasitic features above a larger mass that supports the mountain belt.

Keep, Myra↗

DOE OSTI2021

Unraveling Hidden Order and Dynamics in a Heterogeneous Ferroelectric System Using Machine Learning

We uploaded two batches of datasets: Batch-a) Equilibrium dynamics at a constant temperature at zero electric-field, with one trajectory each for 4-different defect structures (i.e. SETs 1 to 4). Each trajectory has a time-step of 0.25 fs, and is run for 7775000 time-steps, with snapshots written out every 4 time-steps (i.e. every 1fs); and Batch-b) Non-Equilibrium dynamics at a constant temperature with the same 0.25 fs time-step, but data dumped every 500 times-steps (i.e. every 125fs) for each of the SETs. The total trajectory of each defect structure (i.e. each SETs 1 to 4) is 2800000 time-steps (5600 snapshots), with stepping of electric-field by 0.01 V/Ã…, after every 100,000 time-steps (i.e. every 200 snapshots), from E=0 to E=0.05 V/Ã… to E = -0.05 V/Ã… to E=0.05 V/Ã….

36 MATERIALS SCIENCE↗

NASA NTRS1975

Bubble-domain circuit wafer evaluation coil set

Coil structures have been designed to permit nondestructive testing of bubble wafers. Wafers can be electrically or optically inspected and operated from quasi-static frequency to maximum device operating frequency.

Chen, T. T.↗

DOE OSTI2020

Determination of excited state molecular structures from time-resolved gas-phase X-ray scattering

We present a comprehensive investigation of a recently introduced method to determine transient structures of molecules in excited electronic states with sub-ångstrom resolution from time-resolved gas-phase scattering signals. The method, which is examined using time-resolved X-ray scattering data measured on the molecule N-methylmorpholine (NMM) at the Linac Coherent Light Source (LCLS), compares the experimentally measured scattering patterns against the simulated patterns corresponding to a large pool of molecular structures to determine the full set of structural parameters. In addition, we examine the influence of vibrational state distributions and find the effect negligible within the current experimental detection limits, despite that the molecules have a comparatively high internal vibrational energy. Here, the excited state structures determined using three structure pools generated using three different computational methods are in good agreement, demonstrating that the procedure is largely independent of the computational chemistry method employed as long as the pool is sufficiently expansive in the vicinity of the sought structure and dense enough to yield good matches to the experimental patterns.

74 ATOMIC AND MOLECULAR PHYSICS↗