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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 901 records · Page 50
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Reexamining supercritical gas adsorption theories in nano-porous shales under geological conditions

Adsorption is an important phenomenon in surface chemistry, especially for nano-porous shales. In the shale gas-in-place, adsorbed gas could contribute up to 85%. However, adsorption is hard to quantitatively characterize due to different adsorption mechanisms, patterns, surfaces, and pore sizes. Moreover, key thermodynamic parameters, such as the enthalpy of adsorption, are challenging to determine due to uncertainties in adsorbed gas densities used in constructing absolute isotherms. In this paper, we revisit the Brunauer, Emmett, and Teller (BET) model, analytically simplify Ono-Kondo (OK) models for subsurface shales, and compare commonly used mono- and multilayer adsorption models (e.g., Langmuir, supercritical Dubinin-Radushkevich (SDR), supercritical BET (SBET), and simplified OK (OKs) models) with recently proposed pressure-dependent adsorption densities to develop a practical and reliable methodology that can be used in the supercritical state, typical for subsurface black shale conditions.Three independent data sets were used for nitrogen and methane adsorption isotherms at different temperatures. Furthermore, we demonstrate that adsorption predicted by the SDR model is comparable or lower than that predicted by the SBET model, but higher than the amounts predicted by Langmuir and OK models. The nitrogen BET method tends to underestimate the accessible SSA for methane. Measurement of isosteric heat of adsorption is suggested instead of the experimental fitting method, due to the significant difference between the calculated results by two commonly used methods. Experimental fitting and simulation methods are also briefly reviewed to guide future research on shale gas adsorption.

58 GEOSCIENCES↗
DOE OSTI2020

Quantitative investigation of surface structure and interatomic potential with impact-collision ion scattering spectroscopy

Helium ion beam interactions with materials have important implications for magnetic confinement fusion, material modification, and helium ion microscopy. These interactions depend on the precise physics of how helium ions channel into the materials, which can vary greatly based on the local crystalline orientation. Here, we performed a dedicated experiment to investigate helium ion channeling in a well-characterized tungsten single crystal. Time-of-flight impact-collision ion scattering spectroscopy was used to obtain multi-angle maps of the backscattering intensity for 3 keV He + → W(111). We found that the backscattering intensity profile arising from helium ion channeling could be well described by a shadow cone analysis. This analysis revealed that subsurface W atoms as deep as the ninth monolayer contributed to the backscattering intensity profile. Binary collision approximation simulations were performed with MARLOWE to model the experimental maps with sufficient accuracy to allow for quantitative comparisons using reliability factors. These quantitative comparisons were applied to investigate how the W lattice structure and He–W interatomic potential affect the multi-angle maps.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2017

Hydrogeochemical Investigation of Recharge Pathways to Intermediate and Regional Groundwater in Canon de Valle and Technical Area 16, Los Alamos National Laboratory

In aquifers consisting of fractured or porous igneous rocks, as well as conglomerate and sandstone products of volcanic formations, silicate minerals actively dissolve and precipitate (Eby, 2004; Eriksson, 1985; Drever, 1982). Dissolution of hydrated volcanic glass is also known to influence the character of groundwater to which it is exposed (White et al., 1980). Hydrochemical evolution, within saturated zones of volcanic formations, is modeled here as a means to resolve the sources feeding a perched groundwater zone. By observation of solute mass balances in groundwater, together with rock chemistry, this study characterizes the chemical weathering processes active along recharge pathways in a mountain front system. Inverse mass balance modeling, which accounts for mass fluxes between solid phases and solution, is used to contrive sets of quantitative reactions that explain chemical variability of water between sampling points. Model results are used, together with chloride mass balance estimation, to evaluate subsurface mixing scenarios generated by further modeling. Final model simulations estimate contributions of mountain block and local recharge to various contaminated zones.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

Advancing Tunnel Detection Via Vertical Acoustic Profiling

This study demonstrates that placing an acoustic source at depth significantly enhances the detection of tunnels. By adapting the methodology of vertical seismic profiling to acoustic-range frequencies, we introduce a novel approach for tunnel detection. To our knowledge, this report documents the first application of this technique. The field study was conducted on a cleared site at the Oak Ridge National Laboratory; the subsurface was clay. A series of vertical shafts were bored immediately before and after the placement of a 40 ft long, 3 ft diameter steel pipe located 10 ft below the surface. Acoustic signatures were produced at various depths up to 30 ft and an array of surface geophones was used to collect the resulting signals. The innovation lies in using subsurface acoustic signatures to better enable the collection of wide-angle diffracted waves by surface geophones. These diffracted waves appear as subharmonic frequencies of the source signal and are recorded by a surface geophone array. While the concept draws from vertical seismic profiling used in oil and gas exploration, a key distinguishing feature is the use of acoustic frequencies, which are necessary for detecting small subsurface features. The findings have important implications. Critical information pertaining to diffracted source signals are not measured by current state-of-the-art methods. Although this study confirms enhanced detectability, accurate localization and imaging will require additional research. Future work should focus on leveraging diffracted-wave strength and time delays to enable full imaging and characterization.

47 OTHER INSTRUMENTATION↗
NASA NTRS1984

Morphology of fresh craters on Ganymede and the origin of pedestal craters

Properties of the planetary surface and subsurface can affect the morphology of impact craters. A mechanism was proposed to explain pedestal craters and domed floors within fresh craters on Ganymede. Voyager 1 and 2 images with resolutions = to or 3.2 km/lp were examined and 523 fresh craters were identified. For each crater, the rim and ejecta diameters were measured, and the crater was characterized by ejecta class(es), interior features, floor morphology and target terrain. Of the craters examined, 97 show moderate to prominent doming of the crater floor; 340 craters have continuous ejecta which terminates in a scarp pedestal craters, of which 86 (25%) have a high albedo diffuse deposit beyond the pedestal.

Horner, V. M.↗
DOE OSTI2012

Groundwater Transport of Organic Compounds in Old Salvage Yard, Oak Ridge, TN - 12089

In 1950's and early 1960's during production of nuclear weapons at the US Department of Energy Y-12 National Security Complex in Oak Ridge TN, volatile organic compounds (VOCs) as well as heavy metals, nitrates, and radionuclides were released to the environment. Field investigations revealed that much of this contamination is still present in soil, bedrock, and groundwater. Operational buildings and old disposal facilities at the site have been identified as major sources of contamination. The Old Salvage Yard (OSY) on the western side of the site has long been characterized as the major source of VOC contamination in soil and groundwater. In order to analyze the fate and transport of VOC contamination- including tetrachloroethene (PCE), 1,2- dichloroethene (1,2-DCE), cis-1,2-dichloroethene (cis-1,2-DCE) and vinyl chloride (VC) - in groundwater and soil at the vicinity of OSY, an integrated surface and subsurface flow and transport model has been developed for the Y-12 NSC using the hydrodynamic and transport numerical package, MIKE-SHE. Hydrogeological characteristics of the site such as hydraulic conductivity, and transport parameters such as partitioning coefficients were varied in an effort to delineate subsurface flow and transport pathways, potential downstream impacts on Upper East Fork Poplar Creek, and the potential risk to industrial workers involved in related Decontamination and Decommissioning (D and D) activities. The simulation results were compared with the analytical modeling results previously performed by McLane Environmental Inc. using SESOIL-AT123D. Specific simulations have been performed to investigate the effect of possible remedial action (removing the contaminated surface soil layers) on the fate and transport of VOCs. The results of the MIKE-SHE reported here can be considered as an upper limit for the predicted concentrations. Based on MIKE-SHE results, PCE, 1,2 DCE, cis-1,2-DCE, and VC are sources in soil with potential to equal or exceed industrial groundwater hazard and risk levels at the vicinity of OSY. VOC contaminants in soil and groundwater will decay below industrial groundwater risk and hazard levels within approximately 20 years. Excavation of surface soil layers at the site will considerably reduce the concentration of VOCs in groundwater and the possibility of migration of VOCs to surface waters. (authors)

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

Concluding a steam injection remediation project at a dense non-aqueous phase liquid source zone at the Savannah River site - 15303

Multiple subsurface dense non-aqueous phase liquid (DNAPL) source zones served as the sources for a groundwater plume within the A/M Area of the Savannah River Site. Between 1952 and 1985 over 1,600 metric tons of trichloroethylene, tetrachloroethylene, and 1,1,1-trichloroethane were released to the environment resulting in a 648 hectare plume with the M-Area Settling Basin receiving over half of the solvent discharges. In 1991, DNAPL was found in a water table well and steam injection technology was selected to remediate the source zone. Based on characterization data, the treatment area was 1.21 hectare with depths between 13.7 to 50.3 m. The remediation system included 96 vertical, horizontal, and angled steam injection and soil vapor extraction wells and a thermal monitoring system. Construction of the system began in 2004 and operation began in 2005. Steam was applied to the deep vadose zone first, then progressed to the aquifer, followed by the mid-vadose zone. Multiple steam strategies were utilized to enhance mass removal and were concluded in 2009. Soil vapor extraction continues, with residual temperatures in the deep permeability zones still exceeding 65 deg.C. To date over 204 metric tons of volatile organic compounds (VOCs) have been removed. Post-remediation soil, vapor, temperature, and groundwater data were used to evaluate steam injection effectiveness and demonstrated significant reduction in soil concentration, including removal of DNAPL that was evident in several soil cores prior to treatment. Heating the subsurface increased VOC solubility in groundwater and increased mass removal rates outside the target zone. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2014

Annual Report of Monitoring at Morrill, Kansas, in 2013

Carbon tetrachloride contamination in groundwater at Morrill, Kansas, was initially identified in 1985 during statewide testing of public water supply wells for volatile organic compounds (VOCs). High levels of nitrate were also present in the public water supply wells. The city of Morrill is located in Brown County in the northeastern corner of the state, about 7 mi east of Sabetha (Figure 1.1). The population of Morrill as of the 2010 Census was approximately 230 (down from 277 in 2000). All residents of Morrill now obtain their drinking water from the Sabetha municipal water system via a pipeline constructed in 1991. Because the identified carbon tetrachloride contamination in groundwater could potentially be linked, in part, to historical use of carbon tetrachloride-based fumigants at its former facility, in 2003 the CCC/USDA assumed responsibility for investigation of the carbon tetrachloride contamination. The CCC/USDA involvement began with development and implementation of a work plan for a Phase I expedited site characterization. That investigation and subsequent investigations were performed by the Environmental Science Division of Argonne National Laboratory. The initial investigation by the CCC/USDA in 2003 determined that soils at the former facility were not impacted by grain fumigation activities. Neither carbon tetrachloride nor chloroform (the primary degradation product of carbon tetrachloride) was detected in nearsurface soils or in subsurface soils collected to bedrock. Because no identifiable human health risk was associated with either carbon tetrachloride or chloroform in shallow soils, the conclusion was that no further threat of contamination to groundwater was present. In September 2005, the CCC/USDA initiated periodic sampling of groundwater, in accord with a program approved by the KDHE (2005), to monitor carbon tetrachloride concentrations in the groundwater. The report presents the data generated during the 2013 monitoring period.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS2018

High Priority Samples to Characterize the Habitability of Groundwaters and Search for Rock-Hosted Life on Mars with Sample Return

Objective 1.1 of the iMOST sample return objectives is to establish the geologic context, interpret the potential habitability, and evaluate the potential for biosignature preservation in samples from an environment hypothesized to have had elevated potential for Martian life. Here, we describe the strategies required to understand the geologic context and habitability of Martian groundwater aquifers and to search for evidence of life in the Martian subsurface using samples.

Source record↗
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 OSTI2011

Electron Microscopy Characterizations and Atom Probe Tomography of Intergranular Attack in Alloy 600 Exposed to PWR Primary Water

Detailed examinations of intergranular attack (IGA) in alloy 600 were performed after exposure to simulated PWR primary water at 325°C for 500 h. High-resolution analyses of IGA characteristics were conducted on specimens with either a 1 µm diamond or 1200-grit SiC surface finish using scanning electron microscopy, transmission electron microscopy and atom probe tomography techniques. The diamond-polish finish with very little preexisting subsurface damage revealed attack of high-energy grain boundaries that intersected the exposed surface to depths approaching ~2 µm. In all cases, IGA from the surface is localized oxidation consisting of porous, nanocrystalline MO-structure and spinel particles along with regions of faceted wall oxidation. Surprisingly, this continuous IG oxidation transitions to discontinuous, discrete Cr-rich sulfide particles up to ~50 nm in diameter. In the vicinity of the sulfides, the grain boundaries were severely Cr depleted (to <1 at%) and enriched in S. The 1200 grit SiC finish surface exhibited a preexisting highly strained recrystallized layer of elongated nanocrystalline matrix grains. Similar IG oxidation and leading sulfide particles were found, but the IGA depth was typically confined to the near-surface (~400 nm) recrystallized region. Difference in IGA for the two surface finishes indicates that the formation of grain boundary sulfides occurs during the exposure to PWR primary water. The source of S remains unclear, however it is not present as sulfides in the bulk alloy nor is it segregated to bulk grain boundaries.

Olszta, Matthew J.↗
DOE OSTI2023

Time-lapse VSP integration and calibration of subsurface stress field utilizing machine learning approaches: A case study of the morrow B formation, FWU

This study aims to develop a methodology for calibrating subsurface stress changes through time-lapse vertical seismic profiling (VSP) integration. The selected study site is a region around the injector well located within Farnsworth field unit (FWU), where there is an ongoing CO 2 -enhanced oil recovery (EOR) operation. In our study, a site-specific rock physics model was created from extensive geological, geophysical, and geomechanical characterization through 3D seismic data, well logs, and core assessed as part of the 1D MEM conducted on the characterization well within the study area. Here, the Biot-Gassmann workflow was utilized to combine the rock physics and reservoir simulation outputs to determine the seismic velocity change due to fluid substitution. Modeled seismic velocities attributed to mean effective stress were determined from the geomechanical simulation outputs, and the stress-velocity relationship developed from ultrasonic seismic velocity measurements. A machine learning-assisted workflow comprised of an artificial neural network and a particle swarm optimizer (PSO) was utilized to minimize a penalty function created between the modeled seismic velocities and the observed time-lapse VSP dataset. The successful execution of this workflow has affirmed the suitability of acoustic time-lapse measurements for 4D-VSP geomechanical stress calibration pending measurable stress sensitivities within the anticipated effective stress changes and the availability of suitable and reliable datasets for petroelastic modeling. © 2023 Society of Chemical Industry and John Wiley & Sons, Ltd.

58 GEOSCIENCES↗
NASA NTRS1988

A model of diffuse radar scattering from Martian surface rocks

Two physically plausible surface rock-orientation models are presently used to characterize the depolarized component of diffuse radar energy scattering on Mars, and plots of scattering cross-section are derived as a function of Doppler shift. The spectral shapes thus modeled exhibit similarities to observed spectra; their magnitudes are generally within a factor of about 2 of measured values. While surface inhomogeneities could account for the degree of discrepancy, subsurface element scattering may also be implicated.

Calvin, Wendy M.↗
DOE OSTI2026

Modeling Marangoni Convection using a Velocity-Time Relationship

The Waste Treatment and Immobilization Plant (WTP) at the U.S. Department of Energy’s (DOE’s) Handford site is designed to treat 56 million gallons of radioactive waste through vitrification. The melting vessels physical and chemical integrity is essential to maintain, as failure has a high safety and financial penalty. Monofrax® K-3 refractory, the material widely used for the melting vessel, undergoes significant corrosion over time, concentrated at the triple-point junction between the gaseous atmosphere, refractory, and glass melt, producing a characteristic neck-like profile that significantly limits refractory service life. Accurate prediction of the corrosion within the melter can be used to prevent this and extend the lifetime of the melters. A computational fluid dynamics (CFD) model was previously developed, and predicted subsurface refractory corrosion, but failed to predict the neck-line profile observed experimentally. To address this limitation, the glass-melt meniscus geometry at the glass-refractory interface was estimated from experimentally measured neck profiles and wettability experiments. A curve was fitted to the neck profile to identify the triple point location, and the meniscus shape was characterized by a contact angle of 1°. A velocity profile accounting for Marangoni convection-driven corrosion was derived from the estimated meniscus geometry. Surface tension measurements from LORPM14R1 glasses of varying composition were coupled with K-3 coupon dissolution rates to establish a surface tension–time relationship. This analytical velocity-time model was integrated into the existing CFD framework to improve prediction of the neck corrosion profile. Work was done in a computational setting with national collaboration, resulting in professional development through presentational and technical writing growth.

36 - MATERIALS SCIENCE↗
DOE OSTI2011

Lessons Learned from Bacterial Transport Experiments at the South Oyster Site

This paper provides a high-level review of bacterial transport experiments conducted by a multi-investigator, multi-institution, multi-disciplinary team of researchers under the auspices of the U. S. Department of Energy. The experiments considered were conducted during the time period 1999-2001 at a field site near the town of Oyster, Virginia known as the South Oyster Site, and included four major experimental campaigns aimed at understanding and quantifying bacterial transport in the subsurface environment. Several key elements of the research are discussed here: 1) Quantification of bacterial transport in physically and biogeochemically heterogeneous aquifers, 2) evaluation of the efficacy of conventional colloid filtration theory, 3) scale effects in bacterial transport, 4) development of new methods for microbial enumeration and screening for low adhesion strains, 5) application of novel hydrogeophysical techniques for aquifer characterization, and 6) experiences regarding management of a large field research effort.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

Advanced Detection of Wellbore Failure for Safe and Secure Utilization of Subsurface Infrastructure

The main goal of this project was to create a state-of-the-art predictive capability that screens and identifies wellbores that are at the highest risk of catastrophic failure. This capability is critical to a host of subsurface applications, including gas storage, hydrocarbon extraction and storage, geothermal energy development, and waste disposal, which depend on seal integrity to meet U.S. energy demands in a safe and secure manner. In addition to the screening tool, this project also developed several other supporting capabilities to help understand fundamental processes involved in wellbore failure. This included novel experimental methods to characterize permeability and porosity evolution during compressive failure of cement, as well as methods and capabilities for understanding two-phase flow in damaged wellbore systems, and novel fracture-resistant cements made from recycled fibers.

36 MATERIALS SCIENCE↗
DOE OSTI2014

Infrasound Generation from the HH Seismic Hammer.

The HH Seismic hammer is a large, "weight-drop" source for active source seismic experiments. This system provides a repetitive source that can be stacked for subsurface imaging and exploration studies. Although the seismic hammer was designed for seismological studies it was surmised that it might produce energy in the infrasonic frequency range due to the ground motion generated by the 13 metric ton drop mass. This study demonstrates that the seismic hammer generates a consistent acoustic source that could be used for in-situ sensor characterization, array evaluation and surface-air coupling studies for source characterization.

Jones, Kyle Richard↗
DOE OSTI2019

Transport and humification of dissolved organic matter within a semi-arid floodplain: Dataset

Fluorescence excitation-emission matrix (EEM) spectroscopy, humification index (HIX) and specific UV absorbance (SUVA) at 254 nm were to characterize depth and seasonal variations of Dissolved Organic Matter (DOM) composition within sediments of a semi-arid floodplain at Rifle, Colorado, USA. It is expected that these relatively simple spectroscopic measurements (e.g., EEM spectroscopy, HIX and SUVA) applied to depth- and temporally-distributed pore-water samples can provide useful insights into transport and humification of DOM in other subsurface environments as well.

54 ENVIRONMENTAL SCIENCES↗