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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 NTRS2020

Design and Implementation of a Scenario Development Process for a 2040 Trajectory-Based Operations Simulation

The National Aeronautics and Space Administration (NASA) is supporting research to transition from a legacy, air traffic management (ATM) system to Trajectory-Based Operations (TBO) environment targeting the 2035-2045 timeframe by creating simulation scenarios for current and future studies. TBO in the National Airspace System (NAS) focuses on modernizing the current operating paradigm to increase efficiency, predictability, resilience, and flexibility while migrating toward greater operational autonomy across the airspace. These simulation scenarios offer a wide dissemination and use of system-level constraints and aircraft state/intent data, routine use of data communications to request complex trajectory modifications and to receive clearances, and aircraft that are flying on 4-D trajectories with flexibility when desired, but structure where required. This report describes the end-to-end development of scenarios for the NASA Langley Research Center simulation environment to represent a 2040 Trajectory-Based Operations airspace for air transport operations research.

Trajectory-Based Operations↗
DOE OSTI2021

Sludge Batch 10 Frit Development and Variability Study Matrix Design

The Defense Waste Processing Facility (DWPF) is currently preparing to initiate processing of Sludge Batch 10 (SB10), which is comprised of material from Tanks 11H, 13H, 15H, and 26H, and Alternate Feed Stock-2 (AFS-2). H-Canyon also had a need to discard Sodium Reactor Experiment (SRE) material that was stored in Tanks 16.3 and 16.4. Savannah River Remediation (SRR) added a portion of the SRE material to Sludge Batch 9 (SB9) in Tank 40 and the remainder was added to SB10 that is currently being prepared in Tank 51. In support of sludge batch preparation and qualification efforts, SRR requested that the Savannah River National Laboratory (SRNL) complete the following tasks based on the SB10 projections provided by the SRR System Planning group.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2024

Using ethanol and isopropanol as biomass model compounds for understanding bond scission mechanisms over Cu/Mo 2 N catalysts

The conversion of biomass compounds into fuels and chemicals is an important step towards a more sustainable future. This work combines results from model surfaces and powder catalysts to demonstrate Cu-modified mo- lybdenum nitride (Cu/Mo 2 N) as a selective catalyst for dehydrogenation of the biomass model compounds, ethanol and isopropanol. Results from model surfaces showed that while Mo2N led to unselective decomposition via both dehydrogenation and dehydration, the addition of Cu increased the dehydrogenation activity and selectivity. DFT calculations showed how Cu influenced the structures of active sites, adsorbate interactions, and thus the product selectivity. Batch reactor studies on corresponding powder catalysts confirmed the trend that Cu modification increased dehydrogenation activity, and in situ X-ray absorption spectroscopy elucidated the Cu oxidation state under reaction conditions. Further, this work demonstrates a strategy for promoting dehydrogenation over Mo 2 N-based catalysts, as well as the feasibility of using model surfaces to guide the design of industrially relevant catalysts.

09 BIOMASS FUELS↗
DOE OSTI2023

Adsorptive recovery of volatile fatty acids from wastewater fermentation broth

This work developed an adsorptive separation and recovery process for anaerobically generated volatile fatty acids (VFAs) from swine wastewater fermentation. Batch adsorption studies were conducted using several weak anion exchange resins and synthetic adsorbent resins to identify a suitable candidate. Relite RAM2 with a tertiary amine functional group showed the highest adsorption (over 98%) of hexanoic acid. Under the different pH values (1.8–7.5) and extraction temperatures (30–50 ↑C), the highest adsorption was observed at a pH of 3.2, which is below the pKa of hexanoic acid, at all the evaluated temperatures. A full factorial design was used to optimize the resin and VFA concentrations, wherein over 99% adsorption could be achieved when the ratio of VFA to resin was below 0.23 (g/g) for model solution (VFAs in water). The adsorption equilibrium could be achieved within 30 min of contact time and 0.5% w/v NaOH was identified as a suitable desorption agent. Under the optimal conditions, 65–72% of VFAs present in fermentation broth was adsorbed, which was increased to 72–76% by using fresh resins. The VFAs adsorption and recovery efficiency were maintained for 9 successive cycles without requiring extensive resin washing and regeneration for both model solution and fermentation broth. Altogether, the work presents a comprehensive study for resin adsorption to recover VFAs and provides a potential industrial-relevant process to recover VFAs from fermentation broth.

09 BIOMASS FUELS↗
DOE OSTI2024

Mineralogy and reactive fluid chemistry evolution of hydraulically fractured Caney shale of Southern Oklahoma

Here, this study investigates geochemical rock-fluid interactions as a potential cause of rapid loss of permeability and productivity in hydraulically fractured shale reservoirs. It also interrogates the effects of these reactions in transforming depleted shale reservoirs into impermeable carbon storage units. The study employs batch reactor experiments where rock-powder samples are reacted with field fracturing fluid under reservoir temperature (95°C).

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Selective Hydrogenation of Furfural Acetone over a Cu Catalyst: Combined Theoretical and Experimental Study

The selective hydrogenation of biomass-derived hydroxymethyl furfural (HMF)-acetone-HMF (HAH) presents an alternative route to producing highly functionalized polyesters and polyurethanes. While HAH undergoes furan ring hydrogenation over Pd, Ru, and Ni catalysts, furan ring hydrogenation is not observed over Cu. Herein, we combine reaction kinetics experiments and density functional theory calculations to elucidate the selective hydrogenation behavior of HAH over Cu catalysts. We identified furfural acetone (FAc) as a suitable surrogate for modeling HAH hydrogenation over Cu surfaces and performed reaction kinetics experiments between temperatures of 313–393 K and a H 2 partial pressure of 55 bar. Similar to the behavior of HAH, hydrogenation of FAc follows a consecutive two-step hydrogenation pathway over Cu and does not undergo furan ring hydrogenation. The apparent activation energy barriers for hydrogenation of the aliphatic double bond (0.58 eV) and carbonyl (0.43 eV) of FAc measured in a continuous flow reactor setup are consistent with those reported in prior studies for batch HAH hydrogenation. Reaction orders with respect to each reactant, including H 2 and FAc, were determined to be nearly one. Density functional theory (DFT; GGA-PBE-D3) calculations on Cu(111) showed that the hydrogenation of the aliphatic double bond of FAc is more facile than the hydrogenation of the furan ring, which displays weak interactions with the Cu surface. We determined an apparent activation energy barrier for FAc hydrogenation (0.58 eV) that agreed with our DFT predictions (highest barrier for FAc hydrogenation of 0.57 eV). Finally, our DFT calculations further show that weak interactions between the furan ring and Cu surface are responsible for the selective hydrogenation behavior.

Biomass↗
DOE OSTI2024

Adsorption of Neodymium, Dysprosium, and Ytterbium to Goethite under Varying Aqueous Chemistry Conditions

The adsorption of rare earth elements (REEs) to iron oxides can regulate the mobility of REEs in the environment and is heavily influenced by water chemistry. This study utilized batch experiments to examine the adsorption of Nd, Dy, and Yb to goethite under varying pH, electrolyte (type and concentration), and concentrations of dissolved inorganic carbon and citrate. REE adsorption was strongly influenced by pH, with an increase from essentially no adsorption at pH 3.0 to nearly complete adsorption at pH 6.5 and higher. Citrate enhanced the adsorption of REEs at low pH (<5.0), likely by forming goethite-REE-citrate ternary surface complexes. However, citrate inhibited the adsorption of REEs at higher pH (>5.0) by forming aqueous REE-citrate complexes. Ionic strength had a small influence on REE adsorption, and the presence of dissolved inorganic carbon had no discernible effect. Equilibrium adsorption was interpreted with a triple-layer surface complexation model (SCM). The selection of surface complexation reactions was guided by extended X-ray absorption fine structure spectra. An SCM with a single bidentate inner-sphere surface complexation reaction for Nd and two inner-sphere surface complexation reactions (one monodentate and one bidentate reaction) for Dy and Yb effectively simulated adsorption across a broad range of conditions in the absence of citrate. Accounting for the effects of citrate on REE adsorption required the addition of up to two ternary REE-citrate-goethite surface complexes. The SCM can enable predictions of REE transport in subsurface environments that have goethite as an important adsorbent mineral. Furthermore, this predictive capability could contribute to identifying potential REE sources and facilitating efficient extraction of REEs.

58 GEOSCIENCES↗
DOE OSTI2020

Centrifugal Generation of Droplet-Based 3D Cell Cultures

Quickly and easily producing uniform populations of microsphere-based 3D cell cultures using droplet-based templating methods has the potential to enable widespread use of such platforms in drug discovery or cancer research. Here, we advance the design of centrifuge-based droplet generation devices, describe the use of this platform for droplet generation with controlled cell occupancy, and demonstrate weeklong culture duration. Using simple-to-construct devices and easily implemented protocols, the initial concentration of encapsulated cells is adjustable up to hundreds of cells per microsphere. This work demonstrates the first instance of using centrifugal droplet-generating devices to produce large numbers of cell-encapsulating microspheres. Applications of this versatile methodology include the rapid formation of templated 3D cell culture populations suitable for suspension culture or large batch bioreactor studies that require uniform populations.

Biochemistry & Molecular Biology↗
DOE OSTI2025

Humate Amendment Injection Viability Testing – Supplementary Batch Mixture and Soil Column Studies

Groundwater in the Lost Lake Aquifer Zone (LLAZ) in the Southern Sector of the M-Area Hazardous Waste management Facility (HWMF) is contaminated with chlorinated ethenes, including trichloroethylene (TCE) and tetrachloroethylene (PCE). Treatment of contaminated groundwater with humic acid is being evaluated as a potential corrective action for these volatile organic compounds (VOCs) in the LLAZ in Southern Sector (SRNS, 2019). Pilot scale injections of Huma-K brand humic acid for groundwater treatment were previously performed in M-Area between 2017 and 2020 (Amidon, 2023). Groundwater was extracted from the Lost Lake Aquifer Zone (LLAZ), then a solution of humate was mixed with recovered groundwater and subsequently re-injected into the same aquifer unit. Operations of the historical humate pilot testing were discontinued in 2020 due to COVID-19 restrictions, low injection rates, and recirculation fluid spillage. No further field scale or laboratory research to investigate humate amended groundwater injection was performed at the SRS until 2024. At the request of Area Completion Projects (ACP), the Savannah River National Laboratory (SRNL) performed supplementary testing to help determine the viability of further injection of humate as a remedial option for VOCs within the LLAZ in the Southern Sector of the M-Area HWMF.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2023

Produced Fluid Induced Mineralogy and Elemental Alterations of Caney Shale, Southern Oklahoma

ABSTRACT This study involves batch reactor experiments and subsequent analyses of samples from Caney Shale in the Ardmore Basin of South-Central Oklahoma. Samples include mainly rock cores and cuttings recovered from two wells respectively drilled vertically through and horizontally across the Caney Shale. Mineralogical compositions are obtained by X-Ray Diffraction (XRD) measurements whilst microstructure and elemental distribution are acquired by Scanning Electron Microscopy/Energy Dispersive Spectroscopy (SEM/EDS) respectively. Batch experiments are then conducted using selected rock samples and produced fluid from the Caney Formation. Deionized water is also reacted with some samples to serve as standard. Experiments are conducted at 95°C and ambient pressure for 7 and 30 days to assess the geochemical rock-fluid interactions. Results show rock mineralogical compositions are predominantly quartz, feldspar, carbonates, and clay with minor pyrite. Post-experimental mineralogical changes observed in samples include increased amorphous entities especially within the clay portions of XRD plots and dissolution of feldspar and carbonate minerals and formation of new mineral phases, mostly clays and salts. These are corroborated by EDS elemental analyses which show decreased elemental compositions. The implications of reactions mentioned above include but not limited to, scale formation, clay fines migration and shale softening all of which pose significant permeability impairment on formation over time. INTRODUCTION Shale reservoirs account for a large share of unconventional reservoirs in the world (Lyu et al., 2015). However, ultra-low permeability and high clay compositions pose significant challenges when producing from these reservoirs (Dawuda and Srinivasan, 2022, 2023). Producing from these reservoirs therefore requires horizontal drilling and hydraulic fracturing technologies which have proven their efficacy in generating substantial permeability in reservoirs to ensure production (Fujian et al., 2019; Liu et al., 2018). Even after expensive horizontal drilling and hydraulic fracturing, geochemical reactions between engineered fluids and formation leads to fracture constriction and adversely impact petrophysical properties (permeability and porosity) of the reservoir. These technologies are therefore under constant development and improvement in various aspects to ensure fine tuning for specific reservoirs. Under present conditions, much of the hydrocarbon reserves in unconventional shale reservoirs are left unproduced due to rapid decline in permeability following resumption to production after hydraulic fracturing. It is therefore essential to understand the range of geochemical reactions that cause rapid depletion of permeability after hydraulic fracturing and apply these to each shale reservoir to ensure substantial recovery rates.

Awejori, G. A.↗
DOE OSTI2024

Adsorption of neodymium, dysprosium, and ytterbium to goethite under varying aqueous chemistry conditions [dataset]

The adsorption of rare earth elements (REEs) to iron oxides can regulate the mobility of REEs in the environment and is heavily influenced by water chemistry. This study utilized batch experiments to examine the adsorption of Nd, Dy, and Yb to goethite under varying pH, electrolyte (type and concentration), and concentrations of dissolved inorganic carbon and citrate. REE adsorption was strongly influenced by pH, with an increase from essentially no adsorption at pH 3.0 to nearly complete adsorption at pH 6.5 and higher. Citrate enhanced the adsorption of REEs at low pH (< 5.0), likely by forming goethite-REE-citrate ternary surface complexes. However, citrate inhibited the adsorption of REEs at higher pH (> 5.0) by forming aqueous REE-citrate complexes. Ionic strength had a small influence on REE adsorption, and the presence of dissolved inorganic carbon had no discernible effect. Equilibrium adsorption was interpreted with a triple layer surface complexation model (SCM). The selection of surface complexation reactions was guided by extended X-ray absorption fine structure spectra. A SCM with a single bidentate inner-sphere surface complexation reaction for Nd and two inner-sphere surface complexation reactions (one monodentate and one bidentate reaction) for Dy and Yb effectively simulated adsorption across a broad range of conditions in the absence of citrate. Accounting for the effects of citrate on REE adsorption required the addition of up to two ternary REE-citrate-goethite surface complexes. The SCM can enable predictions of REE transport in subsurface environments that have goethite as an important adsorbent mineral. This predictive capability could contribute to identifying potential REE sources and facilitating efficient extraction of REEs.

58 GEOSCIENCES↗
NASA NTRS1985

Microbial colonization and growth on metal sulfides and other mineral surfaces

To determine whether a bacterial film forms on sulfur minerals in situ, various sulfur containing and other minerals were incubated in Penitencia Creek. The rate of cell growth and attachment within the surface microenvironment of mineral surfaces was also determined. To determine whether surfaces enriched with soluble sulfur substrates (cysteine, glutathione, thioglycolate, sulfite, and thiosulfate) increased the rate of growth or attachment of natural communities, membrane enrichments were incubated. These rates were determined as described by Caldwell et al. (1981, 1983). The growth of Pseudomonas fluorescens, a heterotrophic sulfur oxidizer, was studied in batch cell suspensions and in continuous culture. In batch culture the cells were oxygen limited (growth rate 0.33 per hour under oxygen limitations and 0.52 per hour when vigorously aerated). Growth within the film was glucose limited. Several behavioral phenomena were observed for cells growing within the hydrodynamic boundary layer. Despite a flow of 10 cm per second in the environment, the bacteria were able to move freely in both directions within the hydrodynamic boundary layer.

Caldwell, D.↗
NASA NTRS1992

Evaluation of inertial devices for the control of large, flexible, space-based telerobotic arms

Batch simulation studies which show that torque-wheels can reduce the overshoot in abrupt stop commands by 82 percent for a two-link arm are presented. For man-in-the-loop evaluation, a real-time simulator has been developed that samples a hand-controller, solves the nonlinear equations of motion, and graphically displays the resulting motion on a computer workstation. It is shown that, for a single-link arm, a reaction-mass/torque-wheel combination at the payload end can yield a settling time of 3 s for disturbances in the first flexible mode as opposed to 10 s utilizing only a hub motor.

Montgomery, Raymond C.↗
NASA NTRS1995

Simultaneous concentration and purification through gradient deformation chromatography

Mobile-phase additives, commonly used to modulate absorbate retention in gradient elution chromatography, are usually assumed to be either linearly retained or unretained. Previous theoretical work from our laboratory has shown that these modulators, such as salts in ion-exchange and hydrophobic interaction chromatography and organic modifiers in reversed-phase chromatography, can absorb nonlinearly, giving rise to gradient deformation. Consequently, adsorbate peaks that elute in the vicinity of the head of the deformed gradient may exhibit unusual shapes, form shoulders, and/or be concentrated. These effects for a reversed-phase sorbent with aqueous acetonitrile (ACN) as the modulator are verified experimentally. Gradient deformation is demonstrated experimentally and agrees with simulations based on ACN isotherm parameters that are independently determined from batch equilibrium studies using the layer model. Unusual absorbate peak shapes were found experimentally for single-component injections of phenylalanine, similar to those calculated by the simulations. A binary mixture of tryptophan and phenylalanine is used to demonstrate simultaneous concentration and separation, again in agreement with simulations. The possibility of gradient deformation in ion-exchange and hydrophobic interaction chromatography is discussed.

NASA Discipline Number 93-10↗
NASA NTRS1998

Characterizing the Hazard of a Wake Vortex Encounter

The National Aeronautics and Space Administration (NASA) is conducting research with the goal of enabling safe improvements in the capacity of the nation's air transportation system. The wake vortex upset hazard is an important factor in establishing the minimum safe spacing between aircraft during landing and take-off operations, thus impacting airport capacity. Static and free-flight wind tunnel tests and flight tests have provided an extensive data set for improved understanding of vortex encounter dynamics and simulation. Piloted and batch simulation studies are also ongoing to establish a first-order hazard metric and determine the limits of an operationally acceptable wake induced upset. This paper outlines NASA's research in these areas.

Vicroy, Dan D.↗
NASA NTRS2009

Estimation of Separation Buffers for Wind-Prediction Error in an Airborne Separation Assistance System

Wind prediction errors are known to affect the performance of automated air traffic management tools that rely on aircraft trajectory predictions. In particular, automated separation assurance tools, planned as part of the NextGen concept of operations, must be designed to account and compensate for the impact of wind prediction errors and other system uncertainties. In this paper we describe a high fidelity batch simulation study designed to estimate the separation distance required to compensate for the effects of wind-prediction errors throughout increasing traffic density on an airborne separation assistance system. These experimental runs are part of the Safety Performance of Airborne Separation experiment suite that examines the safety implications of prediction errors and system uncertainties on airborne separation assurance systems. In this experiment, wind-prediction errors were varied between zero and forty knots while traffic density was increased several times current traffic levels. In order to accurately measure the full unmitigated impact of wind-prediction errors, no uncertainty buffers were added to the separation minima. The goal of the study was to measure the impact of wind-prediction errors in order to estimate the additional separation buffers necessary to preserve separation and to provide a baseline for future analyses. Buffer estimations from this study will be used and verified in upcoming safety evaluation experiments under similar simulation conditions. Results suggest that the strategic airborne separation functions exercised in this experiment can sustain wind prediction errors up to 40kts at current day air traffic density with no additional separation distance buffer and at eight times the current day with no more than a 60% increase in separation distance buffer.

Consiglio, Maria C.↗
NASA NTRS2003

Solubility and Cation Exchange Properties of Synthetic Hydroxyapatite and Clinoptilolite Mixtures

A zeoponic plant growth system is defined as the cultivation of plants in artificial soils, which have zeolites as a major component. These systems: 1) can serve as a controllable and renewable fertilization system to provide plant growth nutrients; 2) can mitigate the adverse effects of contamination due to leaching of highly soluble and concentrated fertilizers; and 3) are being considered as substrates for plant growth in regenerative life-support systems for long-duration space missions. Batch-equilibrium studies of the dissolution and ion-exchange properties of mixtures of naturally-occurring Wyoming clinoptilolite (a zeolite) exchanged with K(+) or NH4(+); and synthetic hydroxyapatite were conducted to determine: 1) the plant availability of the macro-nutrients NH4-N, P, K, Ca, and Mg and 2) the effects of varying the clinoptilolite to hydroxyapatite ratio and the ratio of exchangeable cations (K(+) vs. NH4(+)) on clinoptilolite extraframework sites. The nutrients NH4-N (19.7 to 73.6 mg L(sup -1), P (0.57 to 14.99 mg L(sup- 1), K (14.8 to 104.9 mg L(sup -1), and Mg (0.11 to 6.68mg L(sup -1) are available to plants at sufficient levels. Solution Ca concentrations (0.47 to 3.40 mg L(sup -1) are less than optimal. Solution concentrations of NH4(+), K(+), Ca(2+), and Mg(2+) all decreased with increasing clinoptilolite to hydroxyapatite ratio in the sample. Solution concentrations of phosphorous initially increased, reached a maximum value and then decreased with increasing clinoptilolite to hydroxyapatite ratio in the sample. The NH4(+) -exchanged clinoptilolite is more efficient in dissolving synthetic hydroxyapatite than the K(+) -exchanged clinoptilolite. This suggests that NH4(+), which is less selective at clinoptilolite extraframework sites than K(+) is exchanged more readily by Ca(2+) and thereby enhances the dissolution of the synthetic hydroxyapatite.

Beiersdorfer, Raymond E.↗
NASA NTRS2011

Integration of Weather Avoidance and Traffic Separation

This paper describes a dynamic convective weather avoidance concept that compensates for weather motion uncertainties; the integration of this weather avoidance concept into a prototype 4-D trajectory-based Airborne Separation Assurance System (ASAS) application; and test results from a batch (non-piloted) simulation of the integrated application with high traffic densities and a dynamic convective weather model. The weather model can simulate a number of pseudo-random hazardous weather patterns, such as slow- or fast-moving cells and opening or closing weather gaps, and also allows for modeling of onboard weather radar limitations in range and azimuth. The weather avoidance concept employs nested "core" and "avoid" polygons around convective weather cells, and the simulations assess the effectiveness of various avoid polygon sizes in the presence of different weather patterns, using traffic scenarios representing approximately two times the current traffic density in en-route airspace. Results from the simulation experiment show that the weather avoidance concept is effective over a wide range of weather patterns and cell speeds. Avoid polygons that are only 2-3 miles larger than their core polygons are sufficient to account for weather uncertainties in almost all cases, and traffic separation performance does not appear to degrade with the addition of weather polygon avoidance. Additional "lessons learned" from the batch simulation study are discussed in the paper, along with insights for improving the weather avoidance concept. Introduction

Consiglio, Maria C.↗