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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 595 records · Page 33
All sourcesNASA NTRSDOE OSTI
NASA NTRS2021

Newmark-Type Pseudo-Three-Dimensional Back-Analysis of Co-Seismic Landslides in Egkremnoi, Lefkada, Greece

A pseudo-three-dimensional (pseudo-3D) methodology to back-analyze coseismic landslides was developed and applied to 68mapped landslides, which occurred over approximately 1 km2area in Egkremnoi, Greece, during the 2015 Mw6.5 Lefkada earthquake. The methodology is based on a one-dimensional (1D) Newmark-type sliding block model to assess instability and a spatial projection in 3D topography to derive landslide geometry. The strength parameters for modeled landslides that best match the landslide location, area, and volume were derived through an iterative scheme that optimizes the match using predefined matching criteria. The range of different-sized landslides produced shear strength estimates from ~10 to 300 kPa and led to the derivation of a regionally averaged strength envelope characterized by a cohesion of 6 kPa and a friction angle of 53°for the highly fractured limestones that are encountered in this area. Compared to previous full 3Dslope stability analyses in this area, the friction angle using this methodology was found to be generally consistent, but the cohesion was lower. The presented methodology can provide a computationally efficient method to estimate the average shear strength of a geologic unit over large areas, especially where extensive field and laboratory tests on the materials are unavailable or difficult to conduct.

Weibing Gong↗
DOE OSTI2024

Investigation of acoustic waves under subsurface conditions to improve the predictions of rock mechanical properties and natural fracture characteristics

Mechanical properties and natural fracture characteristics are critical to investigate for subsurface engineering applications, including carbon storage, well drilling, and stimulation, as they govern rock stability, fluid flow, and mechanical behavior under stress. This dissertation integrates experimental and machine learning approaches to enhance the prediction and understanding of these properties by analyzing acoustic wave behavior under varied subsurface conditions. First, the influence of temperature, pore pressure, and supercritical CO2 (scCO2) saturation on poroelastic properties is examined using Gray Berea sandstone samples. The results show that temperature and pore pressure significantly affect the bulk modulus and Biot’s coefficient, while scCO2 saturation impacts rock compressibility, informing strategies for effective geological carbon storage. The study extends this understanding by experimentally evaluating the impact of reservoir depletion on the dynamic mechanical properties of the emerging Caney shale in South Oklahoma with the employment of unsupervised machine learning to predict static mechanical properties across the Caney shale. Integrating petrophysical data and chemostratigraphy, the workflow—featuring K-means clustering, principal component analysis (PCA), and inverse distance weighting (IDW)—improves stratigraphic characterization and the estimation of static-to-dynamic modulus ratios, which is vital for optimizing drilling and stimulation strategies. Finally, the work explores how natural fracture characteristics in shale influence acoustic waveforms and shear wave splitting (SWS) analysis. Experimental data on fractured samples under different stress and temperature conditions, combined with machine learning models such as K-nearest neighbors (KNN) and extreme gradient boosting (XGBoost), reveal key fracture properties impacting SWS and wave propagation. Together, these studies provide a comprehensive framework for linking acoustic wave behavior with rock properties, advancing the methods for monitoring and predicting geomechanical changes. The insights offered valuable implications for safer, more efficient CO2 injection, hydrocarbon extraction, and subsurface management.

Elkholy, Sherif↗
DOE OSTI2024

Experimental investigation into coal wettability changes caused by reactions with scCO 2 -H 2 O

Geological CO 2 sequestration (GCS) can help mitigate global warming and enhance methane recovery from coal beds. However, few studies have linked the effects of CO 2 to surface chemistry changes controlling wetting behavior in deep coal beds. Contact angles (CAs) of CO 2 /N 2 -high volatile bituminous coal-water systems were measured under different temperatures and pressures. The surface chemistry and physical structure of coals were characterized to investigate changes in physicochemical properties and their relations with wettability after reactions. For N 2 treatment, the time-dependence of static and dynamic CAs were insignificant, ranging within 4°. For gaseous CO 2 treatment, the static CAs and the average advancing angles increased slightly. With supercritical (sc) CO 2 , both the static and dynamic CAs increased significantly, and θ adv changed to intermediate-wet (92°). Reactions with minerals exposed to scCO 2 resulted in greater surface roughness and heterogeneity, greater contact angle hysteresis and more surface sites occupied by scCO 2 rather than H 2 O. Increases in hydrophobic functional groups and decreases in hydrophilicity were shown by FTIR spectra, reflecting the shedding of polar oxygen-containing functional groups, reduction of hydrogen bonds, and increasing percentage of hydrocarbons. XRD patterns obtained following scCO 2 -treatment showed that crystallite growth and molecular polymerization were higher toward graphite-like. The calculated structural parameters of functional groups and crystallites both showed elevated coal rank. Changes in crystallite structure, notably higher carbon content and decreased negative surface charge, are unfavorable for water-wetting. Finally, this study contributes to understanding surface chemistry changes responsible for decreased wettability during CO 2 -enhanced coal bed methane recovery and GCS in coal reservoirs.

01 COAL, LIGNITE, AND PEAT↗
NASA NTRS1973

Analysis study of multispectral data, ERTS-A, from an area in West Pakistan

The author has identified the following significant results. Geomorphic features related to a known porphyry copper deposit at Saindak, western Chagai District, Pakistan, are easily distinguished on ERTS-1 images. New geologic information from the images was used in conjunction with known geology to evaluate one previously known prospect area and to suggest two additional ones, but no new prospects were recognized on the basis of the images alone. The study also showed that Saindak-type deposits are not likely to be present in some extensive areas of the Chagai District. The Saindak deposit is in an area of relatively easily eroded folded sedimentary and volcanic rocks. The deposit is characterized by an elongate zone of easily eroded sulfide-rich rock surrounded by a resistant rim of hornfels and propylitically altered rock. Both this rim and the central sulfide-rich valley are conspicuous features on the images. Swarms of dikes are probably useful for distinguishing real rims from other resistant rock types, but there is no expression of them on the image, although they are easily seen on aerial photographs of the Saindak rim. The investigation showed that a rim like that at Saindak does not form if regional metamorphism has increased the resistance of the country rock to erosion, as in the Pakistan-Iran border region northwest of Saindak.

Schmidt, R. G.↗
NASA NTRS1973

Use of ERTS-1 images in the search for porphyry copper deposits in Pakistani Baluchistan

Geomorphic features related to a known porphyry copper deposit at Saindak, western Chagai District, Pakistan, are easily distinguished on ERTS-1 images. New geologic information from the images was used in conjunction with known geology to evaluate one previously known prospect area and to suggest two additional ones, but no new prospects were recognized on the basis of the images alone. The study also showed that Saindak-type deposits are not likely to be present in some extensive areas of the Chagai District. The Saindak deposit is in an area of relatively easily eroded folded sedimentary and volcanic rocks. The deposit is characterized by an elongate zone of easily eroded sulfide-rich rock surrounded by this rim and the central sulfide-rich valley are conspicuous features on the images. Swarms of dikes are probably useful for distinguishing real rims from other resistant rock types, but there is no expression of them on the image, although they are easily seen on aerial photographs of the Saindak rim.

Schmidt, R. G.↗
NASA NTRS1995

Discrimination of alkalinity in granitoid Rocks: A potential TIMS application

In mineral exploration, the ability to distinguish and map petrochemical variations of magmatic rocks can be a useful reconnaissance tool. Alkalinity is one such petrochemical parameter and is used in the characterization of granitoid rocks. In quartz normative plutonic rocks, alkalinity is related to the composition and abundance of feldspars. Together with quartz abundance, knowledge of feldspar modes allows the classification of these igneous rocks according to the Streckeisen diagram. Alternative classification schemes rely on whole rock geochemistry instead of mineral identifications. The relative ease of obtaining whole rock analyses means that geochemical classifications tend to be favored in exploration geology. But the technique of thermal infrared spectroscopy of rocks yields information on mineralogy and is one that can be applied remotely. The goal of the current work then is to establish whether data from TIMS can be used to distinguish the mineralogical variations that relate to alkalinity. An ideal opportunity to test this thesis arises from the work presented in a paper by Dewitt (1989). This paper contains the results of mapping and analysis of Proterozoic plutonic rocks in north-central Arizona. The map resulting from this work delineates plutons according to alkalinity in an effort to establish a trend or polarity in the regional magmatism. Also contained within this paper are brief descriptions of the mineralogy of half of the region's plutons. This combination of mineralogical and geochemical information was the rationale behind choosing this area as a site for TIMS over flights. A portion of the region centered on the northern Bradshaw Mountains was selected because it contains plutons of all three alkalinity classifications (alkali-calcic, calc-alkalic, and calic) present on DeWitt's map within a relatively small area. The site was flown in August of 1994 and the data received a few days before the writing of this manuscript. Most of this paper is devoted to the description of laboratory based spectroscopy and spectral simulations. These are required to gain insight into the correct procedures for enhancing the relatively small differences in the low spectral resolution TIMS data.

Ruff, Steven W.↗
NASA NTRS2016

The Nexus for Exoplanet System Science

NExSS is a research coordination network dedicated to the study of planetary habitability. A NASA cross-division initiative bringing astrophysicists, planetary scientists, Earth scientists, and heliophysicists together to bring a systems science approach to this problem. NExSS's goals being to investigate the diversity of planets, understanding how planet history, geology, and climate interact to create the conditions for life. Also, to put planets into an architectural context as stellar systems built over time by dynamical processes and sculpted by stars. Use experience from solar system (including Earth) history to identify where habitable niches are most likely to occur and which planets are most likely to be habitable. Leverage NASA investments in research and missions to accelerate discovery and characterization of potential life-bearing worlds.

coordination↗
NASA NTRS2016

High-Temperature, Perhaps Silicic, Volcanism on Mars Evidenced by Tridymite Detection in High-SiO2 Sedimentary Rock at Gale Crater, Mars

The Mars Science Laboratory (MSL) rover, Curiosity, has been exploring sedimentary rocks within Gale crater since landing in August, 2012. On the lower slopes of Aeolis Mons (a.k.a. Mount Sharp), drill powder was collected from a high-silica (74 wt% SiO2) outcrop named Buckskin (BK). It was a surprise to find that the Buckskin sample contained significant amounts of the relatively rare silica polymorph tridymite. We describe the setting of the Buckskin sample, the detection of tridymite by the MSL Chemistry and Mineralogy (CheMin) X-ray diffraction instrument, and detection implications. Geologic setting: The Buckskin outcrop is part of the Murray formation exposed in the Marias Pass area. The formation was previously studied by CheMin in the Pahrump Hills member [1] where three samples of drill fines were analyzed (Confidence Hills (CH), Mojave2 (MJ) and Telegraph Peak (TP) [2]). Assuming approximately horizontal bedding, the Buckskin outcrop is approx.15 m stratigraphically above the bottom of the Pahrump Hills member. Mudstone, generally characterized by fine lamination, is the dominant depositional facies [1]. Buckskin Mineralogical and Chemical Composition: The CheMin instrument and XRD pattern analysis procedures have been previously discussed [3-6]. The diffraction pattern used for quantitative XRD analysis (Fig. 1) is the sum of the first 4 of 45 diffraction images. The remaining images are all characterized by both on-ring and off-ring diffraction spots that we attributed to poor grain motion and particle clumping. Coincident with particle clumping was a significant decrease in the intensity of the tridymite diffraction peaks (Fig. 2a). The derived mineralogical composition of the crystalline component (derived from the first 4 diffraction images) is given in Table 1. The tridymite is well-crystalline and its pattern is refined as monoclinic tridymite (Fig 1). Mineral chemical compositions were derived from XRD unit cell parameters or obtained from stoichiometry. The XRD-calculated amorphous component was 50 +/- 15 wt%. We constrained the value to 60 wt% because it is the minimum value necessary to give a positive Al2O3 concentration for the amorphous component using APXS data for the post-sieve dump pile (Table 2). The amorphous component has high SiO2 (approx.77 wt%) and high anion (SO3+P2O5+Cl ~10 wt%) concentrations. Calculation shows that a cation-anion balance is achieved if the cations in the amorphous component except SiO2 and TiO2, which do not readily form salts, are assumed to be present as amorphous mixed-cation sulfates, phosphates, and chlorides (or perchlorates/ chlorates).

Morris, R. V.↗
NASA NTRS1990

Eastern Aphrodite Terra on Venus - Characteristics, structure, and mode of origin

Altimetric and radar-image cross-strike discontinuities (CSDs) are found to cut across the nearly east-west strike of Eastern Aphrodite (EA) Terra, dividing or segmenting it into offset domains. Each of these domains is characterized by a discontinuous central chasma or trough. These features have been mapped in the altimetric and radar image data of EA on the basis of abrupt termination of riftlike central chasma, offset, and segmentation of the center highlands, and radar image discontinuities previously mapped in Western Aphrodite in terms of length, orientation, and influence on the central highlands and adjacent lowlands. It is concluded that EA displays a variety of geological and geophysical characteristics similar to those occuring at divergent boundaries. The surface map characteristics are the result of a great horizontal motion of the crust diverging from a well-defined linear region, a process that can occur whether the surface is part of a thick and strong plate detached from mantle convection or part of a thin and weak layer attached to a deep convective limb.

Crumpler, L. S.↗
NASA NTRS2020

Evidence for a Stratified Upper Mantle Preserved within the South Pole - Aitken Basin

The evolution and compositional structure of the lunar mantle has been extensively modeled but insufficiently constrained by observations. Here, we identify and characterize mantle materials exposed by the Moon's largest impact basin to better understand the composition, stratigraphy, and evolution of the upper mantle. The vast South Pole-Aitken Basin (SPA) exhibits a broad, crescent-shaped thorium and potassium distribution. These incompatible elements are predicted to be concentrated in the dregs of the lunar magma ocean during end-stage crystallization. Through consideration of basin formation models convolved with subsequent geologic evolution, we demonstrate that the distribution and implied stratigraphy of Th- and K-bearing materials across SPA are consistent with an upper mantle ejecta origin. The most pristine exposures of these materials are confined to northwest SPA and also exhibit elevated Ti and Fe (relative to the farside highlands) in association with a gabbronoritic mineralogy. This is consistent with latestage magma ocean assemblages predicted by petrologic models. In contrast, SPA impact melt derived from greater depths is associated with a low-Ca pyroxene-dominated assemblage. Together, these compositional patterns are evidence for a stratified ancient upper mantle. Importantly, the incompatible-element-enriched, ilmenite-bearing ferroan gabbronoritic cumulates evidently had not participated in gravitational overturn at the time of SPA formation. Contrary to recent hypotheses invoking nearside sequestration of incompatible elements to explain hemispherical differences in crustal building and volcanic resurfacing, it follows that incompatible elements were globally distributed in the magma ocean at the time of SPA formation.

Lunar dichotomy↗
DOE OSTI2024

The damage Mechanics challenge Results: Participant predictions compared with experiment

In this article, We present results from a recent exercise where participating organizations were asked to provide model-based blind predictions of damage evolution in 3D-printed geomaterial analogue test articles. Participants were provided with a range of data characterizing both the undamaged state (e.g., ultrasonic measurements) and damage evolution (e.g., 3-point bending, unconfined compression, and Brazilian testing) of the material. In this paper, we focus on comparisons between the participants’ predictions and the previously secret challenge problem experimental observations. We present valuable lessons learned for the application of numerical methods to deformation and failure in brittle-ductile materials. The exercise also enables us to identify which specific types of calibration data were of most utility to the participants in developing their predictions. Further, we identify additional data that would have been useful for participants to improve the confidence of their predictions. Consequently, this work improves our understanding of how to better characterize a material to enable more accurate prediction of damage and failure propagation in natural and engineered brittle-ductile materials.

36 MATERIALS SCIENCE↗
NASA NTRS1988

Rare earth elements in river waters

To characterize the input to the oceans of rare earth elements (REE) in the dissolved and the suspended loads of rivers, the REE concentrations were measured in samples of Amazon, Indus, Mississippi, Murray-Darling, and Ohio rivers and in samples of smaller rivers that had more distinct drainage basin lithology and water chemistry. It was found that, in the suspended loads of small rivers, the REE pattern was dependent on drainage basin geology, whereas the suspended loads in major rivers had relatively uniform REE patterns and were heavy-REE depleted relative to the North American Shale composite (NASC). The dissolved loads in the five major rivers had marked relative heavy-REE enrichments, relative to the NASC and the suspended material, with the (La/Yb)N ratio of about 0.4 (as compared with the ratio of about 1.9 in suspended loads).

Goldstein, Steven J.↗
NASA NTRSDate not supplied

Data Simulation Using VLIDORT and PCRTM and its Use for Radiometric Calibration of Hyperspectral UV-NIR-SWIR Sensors

Using the vector linearized discrete ordinate radiative transfer model (VLIDORT), a multiple-scattering multi-layer discrete ordinate scattering codes, coupled with a fast principal component (PC) radiative transfer model (PCRTM), we can simulate the radiation fields for hyperspectral UV-NIR-SWIR sensors from 250nm to 2500nm with a very high speed. Since the accurate gas absorptions, molecules and aerosol/cloud particle scatterings, and the surface reflectance have been considered in these simulations, these model data can be used for satellite or airborne sensor design, characterization, or end-to-end system level uncertainty assessment. Comparison of the modelled data with measured results has been a general practice for operational satellite sensor calibrations, such as the Ozone Mapping and Profiler Suite (OMPS) onboard on SNPP and NOAA-20. This presentation will give more details of this simulation system and models. Some examples of the generation of simulations data for CLARREO PathFinder (CPF) and the Surface Biology and Geology (SBG), as well as some examples to use these data for CPF and OMPS radiometric calibration will be presented.

Xiaozhen Xiong↗
NASA NTRS2024

THUNDER: A Titan orbiter mission concept for the New Frontiers program designed at the JPL Planetary Science Summer School

Saturn’s moon Titan is an enigmatic icy world whose surface is constantly modified by its active, Earthlike precipitation system. Here, we propose the THUNDER (Titan’s Hydrocarbons: Uncovering New Dimensions of Evolutionary pRocesses) mission concept to investigate how Titan’s surface reflects the nature of its interior and its active hydrocarbon cycle. This mission will change our understanding of Titan’s surface through three science objectives: characterizing the heat and material transport properties of Titan’s icy outer layer, tracing surface liquid storage through and across the crust, and assessing the total hydrocarbon budget through time. This New Frontiers-class mission, designed as part of the Jet Propulsion Laboratory (JPL) Planetary Science Summer School, responds directly to the call for a Titan orbiter in the NASA Planetary Science and Astrobiology Decadal Survey 2023-2032. THUNDER’s focused geology and geophysics mission could achieve full surface mapping to complement both the Cassini-Huygens and Dragonfly missions using gravity science, radar with three operational modes, and a visible-to-infrared spectrometer. These instruments together could give us the first look at Titan as a fully connected and geologically active world , revolutionizing our understanding of icy bodies, fluvial and atmospheric processes, and habitability across geologic time. Here, we summarize goals of the science mission and engineering approaches, as well as challenges and future directions to study before THUNDER can become a viable mission concept.

mission concept↗
DOE OSTI2025

A quantitative risk assessment framework for fault reactivation in underground hydrogen storage: Coupled simulation and deep learning approach

Underground hydrogen storage (UHS) is emerging as a critical solution for large-scale energy storage. However, like all subsurface fluid injection activities, UHS poses the risk of injection-induced fault reactivation. Accurate risk assessment is essential to ensuring the safety and efficiency of UHS operations. This study presents the development of deep-learning surrogate models for fault reactivation prediction in UHS, trained on a comprehensive database of fully coupled fluid flow-geomechanics simulations. Our findings reveal that analytical models often yield unreliable estimates, with errors up to 54% in the allowable injection pressure, potentially leading to a 40% reduction in UHS operational capacity. The developed surrogate models were incorporated into a quantitative risk assessment (QRA) framework, enabling probabilistic evaluation of fault reactivation risk while accounting for uncertainties in the input variables. Site-specific features, such as horizontal stress gradients, fault’s dip and strike angles, and operational parameters like bottom-hole injection pressure and well-fault distance, were identified as the primary drivers of fault reactivation across various stress regimes. Whereas other hydraulic, geological, and poroelastic reservoir properties were found to have a secondary impact. Notably, we observed that the risk of fault reactivation for a critically oriented fault with a static friction coefficient greater than 0.55 remains below 10% in a normal faulting stress regime. However, the risk significantly increases as the stress regime transitions from normal to strike-slip and ultimately to reverse faulting conditions. These findings underscore the importance of rigorous site characterization and comprehensive QRA evaluations to optimize UHS performance and minimize geomechanical risks.

25 ENERGY STORAGE↗
NASA NTRS1981

Report of activities of the advanced coal extraction systems definition project, 1979 - 1980

During this period effort was devoted to: formulation of system performance goals in the areas of production cost, miner safety, miner health, environmental impact, and coal conservation, survey and in depth assessment of promising technology, and characterization of potential resource targets. Primary system performance goals are to achieve a return on incremental investment of 150% of the value required for a low risk capital improvement project and to reduce deaths and disability injuries per million man-hour by 50%. Although these performance goals were developed to be immediately applicable to the Central Appalachian coal resources, they were also designed to be readily adaptable to other coals by appending a geological description of the new resource. The work done on technology assessment was concerned with the performance of the slurry haulage system.

Lavin, M. L.↗
NASA NTRSDate not supplied

An Overview of SHERLOC Raman and Fluorescence Spectroscopy Results Obtained During Perseverance’s Green Zone Campaign at Jezero Crater, Mars

The Perseverance rover landed in Jezero crater, Mars, in February 2021. The field site was chosen because orbiter data provided evidence that the crater hosted an ancient (>2.7 Ga) fluvio-lacustrine environment. The Octavia E. Butler landing site is located ~1.9 km east of the erosional remnant of the Jezero river delta. Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) is an arm-mounted instrument that combines fluorescence and Raman spectroscopy with microscopic imaging to analyze geological materials in order to better understand the history of the environments recorded in the rocks within Jezero crater and to search for potential biosignatures. SHERLOC has two microscopic cameras, the Autofocus and Context Imager (ACI) and the Wide-Angle Topographic Sensor for Operations and eNgineering, (WATSON). These subsystems obtain high spatial resolution (10.1–100 µm/pixel) images to identify grain-scale structure and texture. SHERLOC spectroscopy enables high-sensitivity detection, characterization, and spatially-resolved correlation of trace organic materials. SHERLOC’s 248.6 nm deep UV laser generates a 100 µm-diameter spot. Photons generated by Raman scattering and fluorescence emission are collected and the spectra are downlinked to Earth for analysis. Knowledge of where the laser is pointed allows for mineral and compositional maps to be generated and overlain in ACI and WATSON images. Early spectroscopy observations focused on natural rock surfaces at targets named Nataani (sol 83), Bi_la_sana (sol 98) and Foux (sol 141). These surfaces included patches of aeolian dust that had settled upon the rocks. Perseverance’s abrasion tool is expected to become available in August 2021; it will grind to depths of 14 mm to remove dust and penetrate coatings and weathering rinds. This presentation will summarize major results from analysis of the rocks examined by SHERLOC during Perseverance’s first science and sample coring campaign (Green Zone Campaign).

Luther W Beegle↗
NASA NTRS1986

A Fourier-based textural feature extraction procedure

A procedure is presented to discriminate and characterize regions of uniform image texture. The procedure utilizes textural features consisting of pixel-by-pixel estimates of the relative emphases of annular regions of the Fourier transform. The utility and derivation of the features are described through presentation of a theoretical justification of the concept followed by a heuristic extension to a real environment. Two examples are provided that validate the technique on synthetic images and demonstrate its applicability to the discrimination of geologic texture in a radar image of a tropical vegetated area.

Stromberg, W. D.↗