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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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All sourcesNASA NTRSDOE OSTI
NASA NTRS1987

A barely implicit correction for flux-corrected transport

In virtue of adding one elliptic equation that must be implicitly solved, the 'barely implicit correction' method presented removes the stringent sidestep limit imposed by sound speed in the explicit methods. The barely implicit method is presently combined with a flux-corrected transport algorithm, which has been rendered fourth-order by the appropriate subtraction of corrected fluxes, in order to accurately represent the sharp gradients in subsonic flows. The multigrid MGRID technique (DeVore, 1984) is used to efficiently solve the elliptic pressure equation.

Patnaik, G.↗
NASA NTRS1991

Semiautomatic Design Of Zonal Computational Grids

EZGrid is knowledge-based computer program semiautomatically generating zonal computational grids for use in numerical simulations of two-dimensional flows. Zoning necessary because of limitations imposed by size of available computer memory and by topological complexity of typical flow field. Complexity and amount of required memory reduced by dividing flow field into zones, within each of which computational grid refined only to extent necessary to resolve local high gradients. Developed to speed and systematize zoning.

Vogel, Alison Andrews↗
NASA NTRS1990

Optimal trajectories for an aerospace plane. Part 1: Formulation, results, and analysis

The optimization of the trajectories of an aerospace plane is discussed. This is a hypervelocity vehicle capable of achieving orbital speed, while taking off horizontally. The vehicle is propelled by four types of engines: turbojet engines for flight at subsonic speeds/low supersonic speeds; ramjet engines for flight at moderate supersonic speeds/low hypersonic speeds; scramjet engines for flight at hypersonic speeds; and rocket engines for flight at near-orbital speeds. A single-stage-to-orbit (SSTO) configuration is considered, and the transition from low supersonic speeds to orbital speeds is studied under the following assumptions: the turbojet portion of the trajectory has been completed; the aerospace plane is controlled via the angle of attack and the power setting; the aerodynamic model is the generic hypersonic aerodynamics model example (GHAME). Concerning the engine model, three options are considered: (EM1), a ramjet/scramjet combination in which the scramjet specific impulse tends to a nearly-constant value at large Mach numbers; (EM2), a ramjet/scramjet combination in which the scramjet specific impulse decreases monotonically at large Mach numbers; and (EM3), a ramjet/scramjet/rocket combination in which, owing to stagnation temperature limitations, the scramjet operates only at M approx. less than 15; at higher Mach numbers, the scramjet is shut off and the aerospace plane is driven only by the rocket engines. Under the above assumptions, four optimization problems are solved using the sequential gradient-restoration algorithm for optimal control problems: (P1) minimization of the weight of fuel consumed; (P2) minimization of the peak dynamic pressure; (P3) minimization of the peak heating rate; and (P4) minimization of the peak tangential acceleration.

Miele, Angelo↗
NASA NTRS1993

An evaluation of satellite-derived humidity and its relationship to convective development

An aircraft prototype of the High-Resolution Interferometer Sounder (HIS) was flown over Tennessee and northern Alabama during summer 1986. The HIS temperature and dewpoint soundings were examined on two flight days to determine their error characteristics and utility in mesoscale analyses. Random errors were calculated from structure functions while total errors were obtained by pairing the HIS soundings with radiosonde-derived profiles. Random temperature errors were found to be less than 1 C at most levels, but random dewpoint errors ranged from 1 to 5 C. Total errors of both parameters were considerably greater, with dewpoint errors especially large on the day having a pronounced subsidence inversion. Cumulus cloud cover on 15 June limited HIS mesoscale analyses on that day. Previously undetected clouds were found in many HIS fields of view, and these probably produced the low-level horizontal temperature and dewpoint variations observed in the retrievals. HIS dewpoints at 300 mb indicated a strong moisture gradient that was confirmed by GOES 6.7-micron imagery. HIS mesoscale analyses on 19 June revealed a tongue of humid air stretching across the study area. The moist region was confirmed by radiosonde data and imagery from the Multispectral Atmospheric Mapping Sensor (MAMS). Convective temperatures derived from HIS retrievals helped explain the cloud formation that occurred after the HIS overflights. Crude estimates of Bowen ratio were obtained from HIS data using a mixing-line approach. Values indicated that areas of large sensible heat flux were the areas of first cloud development. These locations were also suggested by GOES visible and infrared imagery. The HIS retrievals indicated that areas of thunderstorm formation were regions of greatest instability. Local landscape variability and atmospheric temperature and humidity fluctuations were found to be important factors in producing the cumulus clouds on 19 June. HIS soundings were capable of detecting some of this variability. The authors were impressed by HIS's performance on the two study days.

Fuelberg, Henry E.↗
NASA NTRS2006

Improving Thermomechanical Properties of SiC/SiC Composites

Today, a major thrust toward improving the thermomechanical properties of engine components lies in the development of fiber-reinforced silicon carbide matrix composite materials, including SiC-fiber/SiC-matrix composites. These materials are lighter in weight and capable of withstanding higher temperatures, relative to state-of-the-art metallic alloys and oxide-matrix composites for which maximum use temperatures are in the vicinity of 1,100 C. In addition, the toughness or damage tolerance of the SiC-matrix composites is significantly greater than that of unreinforced silicon-based monolithic ceramics. For successful application in advanced engine systems, the SiC-matrix composites should be able to withstand component service stresses and temperatures for the desired component lifetimes. Inasmuch as the high-temperature structural lives of ceramic materials are typically limited by creep-induced growth of flaws, a key property required of such composite materials is high resistance to creep under conditions of use. Also, the thermal conductivity of the materials should be as high as possible so as to minimize component thermal gradients and thermal stresses. A state-of-the-art SiC-matrix composite is typically fabricated in a three-step process: (1) fabrication of a component-shaped architectural preform reinforced by thermally stable high-performance fibers, (2) chemical-vapor infiltration (CVI) of a fiber-coating material such as boron nitride (BN) into the preform, and (3) infiltration of an SiC-based matrix into the remaining porosity in the preform. Generally, the matrices of the highest-performing composites are fabricated by initial use of a CVI SiC matrix component that is typically more thermally stable and denser than matrix components formed by processes other than CVI. As such, the initial SiC matrix component made by CVI provides better environmental protection to the coated fibers embedded within it. Also, the denser CVI SiC imparts to the composite better resistance to propagation of cracks, enhanced thermal conductivity, and higher creep resistance.

DiCarlo, James A.↗
NASA NTRS2013

Automatic extraction of planetary image features

A method for the extraction of Lunar data and/or planetary features is provided. The feature extraction method can include one or more image processing techniques, including, but not limited to, a watershed segmentation and/or the generalized Hough Transform. According to some embodiments, the feature extraction method can include extracting features, such as, small rocks. According to some embodiments, small rocks can be extracted by applying a watershed segmentation algorithm to the Canny gradient. According to some embodiments, applying a watershed segmentation algorithm to the Canny gradient can allow regions that appear as close contours in the gradient to be segmented.

LeMoigne-Stewart, Jacqueline J.↗
DOE OSTI2015

25 Years Of Environmental Remediation In The General Separations Area Of The Savannah River Site: Lessons Learned About What Worked And What Did Not Work In Soil And Groundwater Cleanup

The Savannah River Site (SRS) is owned and administered by the US Department of Energy (DOE). SRS covers an area of approximately 900 square kilometers. The General Separation Area (GSA) is located roughly in the center of the SRS and includes: radioactive material chemical separations facilities, radioactive waste tank farms, a variety of radioactive seepage basins, and the radioactive waste burial grounds. Radioactive wastes were disposed in the GSA from the mid-1950s through the mid-1990s. Radioactive operations at the F Canyon began in 1954; radioactive operations at H Canyon began in 1955. Waste water disposition to the F and H Seepage Basins began soon after operations started in the canyons. The Old Radioactive Waste Burial Ground (ORWBG) began operations in 1952 to manage solid waste that could be radioactive from all the site operations, and ceased receiving waste in 1972. The Mixed Waste Management Facility (MWMF) and Low Level Radioactive Waste Disposal Facility (LLRWDF) received radioactive solid waste from 1969 until 1995. Environmental legislation enacted in the 1970s, 1980s, and 1990s led to changes in waste management and environmental cleanup practices at SRS. The US Congress passed the Clean Air Act in 1970, and the Clean Water Act in 1972; the Resource Conservation and Recovery Act (RCRA) was enacted in 1976; the Comprehensive Environmental Response Compensation, and Liability Act (CERCLA) was enacted by Congress in 1980; the Federal Facilities Compliance Act (FFCA) was signed into law in 1992. Environmental remediation at the SRS essentially began with a 1987 Settlement Agreement between the SRS and the State of South Carolina (under the South Carolina Department of Health and Environmental Control - SCDHEC), which recognized linkage between many SRS waste management facilities and RCRA. The SRS manages several of the larger groundwater remedial activities under RCRA for facilities recognized early on as environmental problems. All subsequent environmental remediation projects tend to be managed under tri-party agreement (DOE, Environmental Protection Agency, and SCDHEC) through the Federal Facilities Agreement. During 25 years of environmental remediation SRS has stabilized and capped seepage basins, and consolidated and capped waste units and burial grounds in the GSA. Groundwater activities include: pump and treat systems in the groundwater, installation of deep subsurface barrier systems to manage groundwater flow, in situ chemical treatments in the groundwater, and captured contaminated groundwater discharges at the surface for management in a forest irrigation system. Over the last 25 years concentrations of contaminants in the aquifers beneath the GSA and in surface water streams in the GSA have dropped significantly. Closure of 65 waste sites and 4 RCRA facilities has been successfully accomplished. Wastes have been successfully isolated in place beneath a variety of caps and cover systems. Environmental clean-up has progressed to the stage where most of the work involves monitoring, optimization, and maintenance of existing remedial systems. Many lessons have been learned in the process. Geotextile covers outperform low permeability clay caps, especially with respect to the amount of repairs required to upkeep the drainage layers as the caps age. Passive, enhanced natural processes to address groundwater contamination are much more cost effective than pump and treat systems. SRS operated two very large pump and treat systems at the F and H Seepage Basins to attempt to limit the release of tritium to Fourmile Branch, a tributary of the Savannah River. The systems were designed to extract contaminated acidic groundwater, remove all contamination except tritium (not possible to remove the tritium from the water), and inject the tritiated groundwater up-gradient of the source area and the plume. The concept was to increase the travel time of the injected water for radioactive decay of the tritium. The two systems were found to be non-effective and potentially mobilizing more contamination. SRS invested approximately $50 million in construction and approximately $100 million in 6 years of operation. The H Seepage Basin pump and treat system was replaced by a series of subsurface barriers that alters the groundwater velocity; the F Seepage Basin pump and treat system was replaced by subsurface barriers forming a funnel and gate augmented by chemical treatment within the gates. These replacement systems are mostly passive and cost approximately $13 million to construct, and have reduced the tritium flux to Fourmile Branch, in these plumes, by over 70%. SRS manages non-acidic tritiated groundwater releases to Fourmile Branch from the southwest plume of the MWMF with a forest irrigation system. Tritiated water is captured with a sheetpile dam below the springs that caused releases to Fourmile Branch. Water from the irrigation pond is pumped to a filter plant prior to irrigation of approximately 26 hectares of mixed forest and developing pine plantation. SRS has almost achieved a 70% reduction in tritium flux to the Branch from this plume. The system cost approximately $5 million to construct with operation cost of approximately $500K per year. In conclusion, many lessons have been learned in 25 years of relatively aggressive remedial activities in the GSA. Geotextile covers outperform low permeability clay caps, especially with respect to the amount of repairs required to upkeep the drainage layers as the caps age. Passive, enhanced natural processes to address groundwater contamination are much more cost effective than pump and treat systems. In water management situations with non-accumulative contaminants (tritium, VOCs, etc.) irrigation in a forest setting can be very effective.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

Entropic and gradient flow formulations for nonlinear diffusion

Nonlinear diffusion ∂{sub t}ρ = Δ(Φ(ρ)) is considered for a class of nonlinearities Φ. It is shown that for suitable choices of Φ, an associated Lyapunov functional can be interpreted as thermodynamic entropy. This information is used to derive an associated metric, here called thermodynamic metric. The analysis is confined to nonlinear diffusion obtainable as hydrodynamic limit of a zero range process. The thermodynamic setting is linked to a large deviation principle for the underlying zero range process and the corresponding equation of fluctuating hydrodynamics. For the latter connections, the thermodynamic metric plays a central role.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2021

Ultra-Fast Vertical Ordering of Lamellar Block Copolymer Films on Unmodified Substrates

To utilize the full potential of block copolymer (BCP) thin films for use in technological devices ranging from ion conduction membranes, transistors to nanowire array antennas, rapid self- assembly of lamellar block copolymers (l-BCPs) with vertically oriented lamellar domains on a variety of unmodified substrates is needed. l-BCPs have an inherently larger interfacial area for transport compared to their cylindrical counterpart. Our observations demonstrate that the as-cast weakly ordered vertically oriented state of l-BCP films of polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) from directional evaporation of select solvents, act as “seed templates” for their ultra-fast evolution (~30 s) into well-ordered vertically oriented nanostructures, using a thermal gradient-based Cold Zone Annealing (CZA) technique. Furthermore, vertical lamellae are obtained on unmodified substrates, Quartz and Kapton, and the kinetics of l-BCP ordering is much faster by CZA as compared to the isotropic oven annealing. The rapid ordering kinetics of vertical l-BCPs is tested and found applicable to different molecular weights and film thicknesses ranging from 20 nm to 480 nm, which ultimately flip over to their equilibrium parallel morphology at upper limits of annealing times. This rapid ordering strategy for vertical orientation of l-BCPs using roll-to-roll compatible CZA would be highly relevant for fundamental studies of interfacial transport as well as for industrial applications from membranes to nanowires.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2026

Toward Intelligent Multimodal Holography for Real-Time Chemical Imaging of Dynamic Ion Separation

Molecular-level visualization of ion transport and separation dynamics in complex environments is crucial for advancing energy systems, water purification, and critical materials recovery. Achieving this requires imaging platforms that combine structural sensitivity, chemical specificity, and real-time operation. Digital off-axis holography (DOAH) provides high-throughput, label-free quantitative phase imaging but inherently lacks chemical selectivity. Integrating DOAH with complementary spectroscopic channels such as fluorescence or hyperspectral imaging introduces the needed molecular specificity, while also creating challenges in multimodal data fusion, synchronization, and computational throughput. Artificial intelligence offers a powerful route to address these limitations by uniting physics-based reconstruction with data-driven interpretation. In this Perspective, we outline a framework for intelligent multimodal holography and demonstrate its potential using a preliminary AI-driven test case. Raw DOAH holograms of lanthanide solutions subjected to magnetic field gradients were analyzed using multi-agent AI workflows that autonomously selected reconstruction tools, extracted NMF components, and generated scientific claims consistent with true paramagnetic and diamagnetic behavior. This demonstration shows how AI-enabled reasoning can deliver real-time chemical–structural interpretation directly from raw holograms. Together, these advances define a path toward adaptive, intelligent holography platforms capable of supporting in situ chemical separations, dynamic ion transport analysis, and next-generation interfacial science.

Ricchiuti, Giovanna↗
DOE OSTI2026

Operando neutron radiography validates a parameter-free transport–kinetics model for thick solid-state battery cathodes

Tortuosity-weighted interfacial flux for lithium (TWIF-Li) predicts through-thickness Li gradients in thick composite all-solid-state cathodes without fitted parameters. Image-derived microstructures, GITT-derived concentration-dependent solid diffusion, and tortuosity-weighted interfacial kinetics reproduce operando neutron radiography across practical rates, delivering transferable design rules to suppress transport-limited reaction fronts.

Adam, Andre [ORNL] (ORCID:0000000245023033)↗
DOE OSTI2015

First principles study of thermal conductivity cross-over in nanostructured zinc-chalcogenides

Systematic first principles studies of zinc-chalcogenides have been performed to understand their thermal transport behaviour. We have applied the Boltzmann transport equation in the relaxation time approximation to calculate the thermal conductivity of ZnS, ZnSe, and ZnTe. We find a thermal conductivity cross-over between ZnS and ZnSe at nanostructure sizes around 0.1–0.2 μm and explain this in terms of the different contributions of phonon modes in these materials. We study the effect of nanostructuring using both the diffusive boundary scattering and confined mean free path limit and discuss the variations in the results. Furthermore, we show the strong influence of isotope scattering on the thermal conductivity. The calculated thermal conductivity is found to be strongly dependent on the volume and we explain the observed differences between local density and generalized gradient approximation calculations. We compare further calculated thermal properties, such as the thermal expansion coefficient, to experiment to validate our approach.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2013

Astrophysical tests of modified gravity: the morphology and kinematics of dwarf galaxies

This paper is the third in a series on tests of gravity using observations of stars and nearby dwarf galaxies. We carry out four distinct tests using published data on the kinematics and morphology of dwarf galaxies, motivated by the theoretical work of Hui et al. (2009) and Jain and Vanderplas (2011). In a wide class of gravity theories a scalar field couples to matter and provides an attractive fifth force. Due to their different self-gravity, stars and gas may respond differently to the scalar force leading to several observable deviations from standard gravity. HI gas, red giant stars and main sequence stars can be displaced relative to each other, and the stellar disk can display warps or asymmetric rotation curves aligned with external potential gradients. To distinguish the effects of modified gravity from standard astrophysical phenomena, we use a control sample of galaxies that are expected to be screened from the fifth force. In all cases we find no significant deviation from the null hypothesis of general relativity. The limits obtained from dwarf galaxies are not yet competitive with the limits from cepheids obtained in our first paper, but can be improved to probe regions of parameter space that are inaccessible using other tests. We discuss how our methodology can be applied to new radio and optical observations of nearby galaxies.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2015

Unified description of linear screening in dense plasmas

Electron screening of ions is among the most fundamental properties of plasmas, determining the effective ionic interactions that impact all properties of a plasma. With the development of new experimental facilities that probe high-energy-density physics regimes ranging from warm dense matter to hot dense matter, a unified framework for describing dense plasma screening has become essential. Such a unified framework is presented here based on finite-temperature orbital-free density functional theory, including gradient corrections and exchange-correlation effects. We find a new analytic pair potential for the ion-ion interaction that incorporates moderate electronic coupling, quantum degeneracy, gradient corrections to the free energy, and finite temperatures. This potential can be used in large-scale “classical” molecular dynamics simulations, as well as in simpler theoretical models (e.g., integral equations and Monte Carlo), with no additional computational complexity. The new potential theoretically connects limits of Debye-Hückel–Yukawa, Lindhard, Thomas-Fermi, and Bohmian quantum hydrodynamics descriptions. In conclusion, based on this new potential, we predict ionic static structure factors that can be validated using x-ray Thomson scattering data.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2024

RESONANT MATCHING SECTION FOR CEBAF ENERGY UPGRADE

Thomas Jefferson National Accelerator Facility (Jeffer- son Lab) currently studies the feasibility of upgrading its energy to 22 GeV. It considers addition of six more linac passes. The highest energy passes will share two new arcs designed using the Fixed-Field Alternating Gradient (FFA) technology. The FFA arcs are built using permanent combined-function magnets. They will be connected to the linacs through transition sections that will match the optics of all six passes to the linacs. With the high number of con- straints and the limited space available, we are investigating a parametric resonance technique to match the optics quasi- independently at each energy. A resonance is excited at each individual energy to selectively control its optics. The reso- nant dipole and quadrupole kick harmonics are imposed for all energies simultaneously using Panofsky corrector mag- nets placed throughout the FFA arcs. This paper presents the current progress on that transition section design

Deitrick, K.↗
DOE OSTI2019

RECENT DEVELOPMENTS OF Nb3Sn AT JEFFERSON LAB FOR SRF ACCELERATOR APPLICATION

The desire to reduce the construction and operating costs of future SRF accelerators motivates the search for alternative, higher-performing materials. Nb3Sn (Tc ~ 18.3 K and Hsh ~ 425 mT) is the front runner. However, tests of early Nb3Sn-coated cavities encountered strong Q-slopes limiting the performance. Learnings from studies of coated materials related to cavity performance prompted significant changes to the coating process. It is now possible to routinely produce slope-free cavities having Q0 > 2×1010 at 4 K and > 4×1010 up to the accelerating gradient in excess of 15 MV/m at its best. Obtaining similar results in five-cell cavities is a current goal to test them under an accelerator environment. This contribution discusses recent developments at Jefferson Lab.

Pudasaini, Uttar↗
DOE OSTI2018

Ion Transport Dynamics at Nanoscale Interfaces in Single Asymmetric Nanopores and Nanopore Arrays (Final Scientific and Technological Report)

The grant (DE-SC0019043) from the Department of Energy’s Office of Basic Energy Sciences has an overarching goal of establishing mechanistic understanding on the emerging time-dependent ion transport behaviors at nanometer scale interfaces in single nanopores and nanopore arrays with broken symmetry. The fundamental research aims to ultimately advance applications such as ion separation and desalination, or water purification; and energy harvesting, or power generation from salinity gradients. Water desalination refers to the process that removes excess salt or electrolyte ions from water to obtain fresh water. This process consumes energy and is important considering the increasing demand for fresh water, energy cost, concerns on environmental impacts, and needs in resource-limited conditions. The reverse process of desalination, for example where sea/brackish water and river/fresh water meet, can serve as unconventional sources to extract energy, sometimes referred as blue energy harvesting. A critical bottleneck in those and other relevant applications is the tradeoff in selectivity and throughput of ion transport, in other words the ability to discriminate and control the transport of ions against solvent water and/or among different ions. Fundamental insights and new design principles are needed to improve the efficacy and efficiency of the materials and devices for those applications. The green chemistry approaches in addressing energy and environmental challenges have been instrumental in inspiring the students at Georgia State University, an urban R-1 minority-serving institution that is both a predominantly black and hispanic serving institution, through PI’s research and teaching endeavors amid the significant impacts by the pandemic during the grant period.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2024

An ML-based terrestrial data fusion and augmentation framework to enable advanced understanding of the terrestrial carbon and water interactions

Soil moisture is essential to the terrestrial carbon and water cycles and land–atmosphere interactions. There are various types of soil moisture data, and each type has the distinct spatiotemporal strengths and limitations, depending on the diverse applications and retrieval methodologies of different data types (Li et al., in review; The PNNL-82151 FY23 Report). However, the limitations of different soil moisture data in terms of accuracy and spatiotemporal coverage hinder our ability to further understand the soil moisture dynamics across scales. To have a gap free soil moisture data product with a fine spatiotemporal coverage and vertical profiles, we train extreme gradient boosting (XGBoost) models by using (1) in-situ soil moisture measurements from the International Soil Moisture Network (ISMN), (2) soil moisture from the ECMWF reanalysis (ERA) at the 9 km and sub-daily spatiotemporal resolution, (3) the Daymet meteorological fields, and (4) data products that characterize surface conditions, including soil texture, organic content, topography, vegetation type, and rooting depth. We use the trained XGBoost models that have consistent performance across seven soil layers, i.e., 0–5 cm, 5–10 cm, 10–20 cm, 20–40 cm, 40–60 cm, 60–100 cm, and 100–200 cm, and the gridded model predictors to generate a soil moisture data at the 1 km and daily spatiotemporal resolution for the Continental United States (CONUS) from 2001–2020. This dataset can be broadly used for Earth system model benchmark, monitoring extreme weathers, making informed decisions regarding agriculture, water resource management, climate change mitigation, and ecosystem preservation.

58 GEOSCIENCES↗