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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 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Investigations of Spatial and Temporal Variability of Ocean and Ice Conditions in and Near the Marginal Ice Zone. The “Marginal Ice Zone Observations and Processes Experiment” (MIZOPEX) Final Campaign Summary

Despite the significance of the marginal ice zones of the Arctic Ocean, basic parameters such as sea surface temperature (SST) and a range of sea-ice characteristics are still insufficiently understood in these areas, and especially so during the summer melt period. The field campaigns summarized here, identified collectively as the “Marginal Ice Zone Ocean and Ice Observations and Processes Experiment” (MIZOPEX), were funded by U.S. National Aeronautic and Space Administration (NASA) with the intent of helping to address these information gaps through a targeted, intensive observation field campaign that tested and exploited unique capabilities of multiple classes of unmanned aerial systems (UASs). MIZOPEX was conceived and carried out in response to NASA’s request for research efforts that would address a key area of science while also helping to advance the application of UASs in a manner useful to NASA for assessing the relative merits of different UASs. To further exercise the potential of unmanned systems and to expand the science value of the effort, the field campaign added further challenges such as air deployment of miniaturized buoys and coordinating missions involving multiple aircraft. Specific research areas that MIZOPEX data were designed to address include relationships between ocean skin temperatures and subsurface temperatures and how these evolve over time in an Arctic environment during summer; variability in sea-ice conditions such as thickness, age, and albedo within the marginal ice zone (MIZ); interactions of SST, salinity, and ice conditions during the melt cycle; and validation of satellite-derived SST and ice concentration fields provided by satellite imagery and models.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

The Near Zone to Far Zone Transformation (N2F)

N2F is a C/C++ code used to calculate the far zone electromagnetic (EM) field, given E and H near zone field data. The method used by N2F can be found in Ref. 1 and 2. N2F determines the far field E Φ and E θ in spherical coordinates for near zone data calculated in either Cartesian or Cylindrical geometry.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2017

Seismic Measurement of the Locations of the Base of Convection Zone and Helium Ionization Zone for Stars in the Kepler Seismic LEGACY Sample

Acoustic glitches are regions inside a star where the sound speed or its derivatives change abruptly. These leave a small characteristic oscillatory signature in the stellar oscillation frequencies. With the precision achieved by Kepler seismic data, it is now possible to extract these small amplitude oscillatory signatures, and infer the locations of the glitches. We perform glitch analysis for all the 66 stars in the Kepler seismic LEGACY sample to derive the locations of the base of the envelope convection zone (CZ) and the helium ionization zone. The signature from helium ionization zone is found to be robust for all stars in the sample, whereas the CZ signature is found to be weak and problematic, particularly for relatively massive stars with large errorbars on the oscillation frequencies. We demonstrate that the helium glitch signature can be used to constrain the properties of the helium ionization layers and the helium abundance.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2019

High pO(2) Floating Zone Crystal Growth of the Perovskite Nickelate PrNiO3

Single crystals of PrNiO3 were grown under an oxygen pressure of 295 bar using a unique high-pressure optical-image floating zone furnace. The crystals, with volume in excess of 1 mm(3), were characterized structurally using single crystal and powder X-ray di ff raction. Resistivity, specific heat, and magnetic susceptibility were measured, all of which evidenced an abrupt, first order metal-insulator transition (MIT) at similar to 130 K, in agreement with previous literature reports on polycrystalline specimens. Temperature-dependent single crystal di ff raction was performed to investigate changes through the MIT. Our study demonstrates the opportunity space for high fugacity, reactive environments for single crystal growth specifically of perovskite nickelates but more generally to correlated electron oxides.

floating zone method↗
DOE OSTI2020

Flexible and Modular Simultaneous Modeling of Flow and Reactive Transport in Rivers and Hyporheic Zones

Investigations of coupled multiphysics processes in rivers and hyporheic zones have extensively used numerical models. Most existing models use a sequential, one-way coupling between the surface and subsurface domains. Such one-way coupling potentially introduces error. To overcome this, a fully coupled model, hyporheicFoam, was developed using the open-source computational platform OpenFOAM. It captures the coupled flow and multicomponent reactive transport processes within both surface and subsurface domains and across their interface. The coupling between two domains is implemented by mapping conservative flux boundary conditions at the interface through an iterative algorithm. Reactive transport is enabled by specifying a reaction network. To start, we have implemented reaction kinetics following the double Monod-type model with inhibition. The model capability is illustrated through modeling of both conservative and reactive hyporheic flow and transport through dune bedforms. With the novel coupled model, it is now possible to quantify reactions wherein the reactants and products are constantly exchanging between domains and have feedbacks. hyporheicFoam can simulate large, three-dimensional cases owing to the computational flexibility and power offered by the code structure and parallel design of OpenFOAM.

58 GEOSCIENCES↗
DOE OSTI2019

Fenestrated Thoracic Endovascular Aortic Repair Using Physician-Modified Stent Grafts (PMSGs) in Zone 0 and Zone 1 for Aortic Arch Diseases

Purpose: To evaluate the outcomes of fenestrated thoracic endovascular aortic repair (f-TEVAR) using physician-modified stent grafts (PMSGs) in zone 0 and zone 1 for aortic arch diseases. Methods: f-TEVAR using PMSGs in Z0 and Z1 was performed on ten high-risk patients for open surgery from November 2015 to September 2017. Indications were complicated acute type B dissection (ABAD) with retrograde dissection involving the mid-arch (n = 1), distal arch aneurysms (n = 3), mid-arch aneurysms of the inner arch curvature (n = 3) and penetrating aortic ulcer located in the mid- or proximal arch (n = 3). Pre-, intra- and postoperative clinical data were recorded. Results: The median patient age was 61 (range 45–81) years, and 9 (90%) patients were men. Ten PMSGs (Medtronic Valiant stent grafts, n = 1; Relay thoracic stent grafts, n = 4; Cook TX2 device, n = 5) were deployed. PMSGs were deployed from Z0 and Z1 in 5 and 5 patients, respectively. Double small fenestrations for the left subclavian artery (LSA) and the left common carotid artery (LCCA), respectively, were created in 3 patients. Triple small fenestrations for the innominate artery (IA), the LCCA and the LSA, respectively, were created in 2 patients. One large fenestration for both the IA and the LCCA combined with one small fenestration for the LSA was created in 3 patients. One large fenestration for the LCCA combined with one small fenestration for the LSA was created in 2 patients. Posterior diameter-reducing ties were added to all the devices except to one Valiant stent graft. All but 2 patients underwent elective procedure. Median duration for stent graft modifications was 105 (range 90–125) min. The technical success rate was 90%. Overall mortality was 10% (1/10). One patient died of sudden cardiac arrest intraoperatively after the deployment of the PMSG and all the supra-aortic branch stents. Mean operative time was 106.0 ± 43.0 min, and fluoroscopy time was 30.6 ± 22.9 min. There were no type I or type III endoleaks, perioperative neurological complications or spinal cord ischemia. Median length of stay was 8 (range 4–35) days. Nine patients survived at mean 13.3 (range 6.0–19.0) months follow-up. Retrograde dissection occurred in one patient of Z0 group 40 days post-f-TEVAR and resolved after open repair. During follow-up, all target vessels remained patent without fenestration-related type I or III endoleaks. Conclusions: f-TEVAR using PMSGs in Z0 and Z1 for the treatment of aortic arch diseases in high-risk patients is feasible in the hands of experienced operators.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2023

The Variable Continuous Bimaterial Interface in the San Jacinto Fault Zone Revealed by Dense Seismic Array Analysis of Fault Zone Head Waves

Key factors controlling earthquake ruptures include fault geometry, continuity, and seismic velocity structure around the fault. We present a novel tool that better informs deep bimaterial fault geometry embedded in distributed damage and seismicity, associated velocity contrasts across the fault, and their correlations with surface complexities. The method employs fault zone head and direct body waves and is applied to recordings from five spatiotemporally different seismic arrays along the complex San Jacinto fault zone (SJFZ) in southern California. We detect and distinguish these signals based on instantaneous phase coherence and relative energy in a cascading manner from one scale array to another. The analysis reveals a >70-km long continuous bimaterial interface within the SJFZ with several deep northeast dipping fault segments. The northern SJFZ, for instance, locates ~7 km northeast of its surface expression at 18-km depth. P-wave velocity contrasts range from near 0% to >15%, consistent with other bimaterial faults, and differ by a few % depending on fault-array azimuth, implying directional-dependent velocity contrasts. S-wave head waves and velocity contrasts are also imaged for the first time at the southern SJFZ, averaging to 2.9% in agreement with tomography results. The imaged geometry and continuity suggest the SJFZ initiated along remnant tectonic structures and translates to a rupture potential of M > 7.2, i.e., the sizes of its largest paleo-earthquakes. The P and S contrasts, and their ratios, have important implications for earthquake rupture speed, mode, directivity, and frictional heating along the SJFZ and other major faults globally.

58 GEOSCIENCES↗
DOE OSTI2017

Hydrogen-bearing iron peroxide and the origin of ultralow-velocity zones

Ultralow-velocity zones (ULVZs) at Earth’s core–mantle boundary region have important implications for the chemical composition and thermal structure of our planet, but their origin has long been debated. Hydrogen-bearing iron peroxide (FeO 2 H x ) in the pyrite-type crystal structure was recently found to be stable under the conditions of the lowermost mantle. Using high-pressure experiments and theoretical calculations, we find that iron peroxide with a varying amount of hydrogen has a high density and high Poisson ratio as well as extremely low sound velocities consistent with ULVZs. Here in this paper we also report a reaction between iron and water at 86 gigapascals and 2,200 kelvin that produces FeO 2 H x . This would provide a mechanism for generating the observed volume occupied by ULVZs through the reaction of about one-tenth the mass of Earth’s ocean water in subducted hydrous minerals with the effectively unlimited reservoir of iron in Earth’s core. Unlike other candidates for the composition of ULVZs, FeO 2 H x synthesized from the superoxidation of iron by water would not require an extra transportation mechanism to migrate to the core–mantle boundary. These dense FeO2Hx-rich domains would be expected to form directly in the core–mantle boundary region and their properties would provide an explanation for the many enigmatic seismic features that are observed in ULVZs

58 GEOSCIENCES↗
DOE OSTI2013

Effects of ion-neutral collisions on Alfven waves: The presence of forbidden zone and heavy damping zone

Alfven waves are low-frequency transverse waves propagating in a magnetized plasma. We define the Alfven frequency {omega}{sub 0} as {omega}{sub 0}=kV{sub A}cos{theta}, where k is the wave number, V{sub A} is the Alfven speed, and {theta} is the angle between the wave vector and the ambient magnetic field. There are partially ionized plasmas in laboratory, space, and astrophysical plasma systems, such as in the solar chromosphere, interstellar clouds, and the earth ionosphere. The presence of neutral particles may modify the wave frequency and cause damping of Alfven waves. The effects on Alfven waves depend on two parameters: (1) {alpha}=n{sub n}/n{sub i}, the ratio of neutral density (n{sub n}), and ion density (n{sub i}); (2) {beta}={nu}{sub ni}/{omega}{sub 0}, the ratio of neutral collisional frequency by ions {nu}{sub ni} to the Alfven frequency {omega}{sub 0}. Most of the previous studies examined only the limiting case with a relatively large neutral collisional frequency or {beta} Much-Greater-Than 1. In the present paper, the dispersion relation for Alfven waves is solved for all values of {alpha} and {beta}. Approximate solutions in the limit {beta} Much-Greater-Than 1 as well as {beta} Much-Less-Than 1 are obtained. It is found for the first time that there is a 'forbidden zone (FZ)' in the {alpha}-{beta} parameter space, where the real frequency of Alfven waves becomes zero. We also solve the wavenumber k from the dispersion equation for a fixed frequency and find the existence of a 'heavy damping zone (HDZ).' We then examine the presence of FZ and HDZ for Alfven waves in the ionosphere and in the solar chromosphere.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2013

Energy Zones Study: A Comprehensive Web-Based Mapping Tool to Identify and Analyze Clean Energy Zones in the Eastern Interconnection

This report describes the work conducted in support of the Eastern Interconnection States’ Planning Council (EISPC) Energy Zones Study and the development of the Energy Zones Mapping Tool performed by a team of experts from three National Laboratories. The multi-laboratory effort was led by Argonne National Laboratory (Argonne), in collaboration with the National Renewable Energy Laboratory (NREL) and Oak Ridge National Laboratory (ORNL).

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2022

Composite Analysis Vadose Zone Transport of Selected Hanford Site Composite Analysis: Vadose Zone Transport of Selected Radionuclides Released from DOE O 435.1 Waste Sites

The main objectives of the composite analysis (CA) compliance case vadose zone (VZ) facet are to simulate transport of radionuclide releases from the surface to the water table, and to provide radionuclide transfer rates to groundwater for inclusion into the Plateau-to-River (P2R) saturated zone (SZ) model (CP-57037, Model Package Report: Plateau to River Groundwater Model, Version 8.3). The parallel exascale version of the Subsurface Transport Over Multiple Phases (eSTOMP) simulator is used to simulate flow and transport for the CA VZ models. The CA compliance case approach to address the scale and distribution of contaminant sources in the VZ facet is to subdivide the Hanford Site Central Plateau into 26 models that contain contaminant sources and liquid discharges likely to commingle during migration through the VZ to the water table.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Forecasting Commercial Building Electricity Consumption, Zone Airflow and Zone Temperature: Update - Development of a Generalized Machine Learning Approach

The U.S. power grid is being transformed to make it smarter, more efficient, and cleaner. This transformation is leading to the addition of a significant of energy generated by distributed, variable, and renewable resources. Because of the variable nature of renewable generation, the short- and long-term supply and demand imbalances are less predictable, and conventional approaches to mitigating the imbalances will be less efficient or cost effective. To address this challenge and to support the mission and the vision of the U.S. Department of Energy’s (DOE’s) Office of Energy Efficiency and Renewable Energy (EERE) Building Technologies Office has developed a Grid-Interactive Efficient Building Strategy. The strategy focuses on simultaneously improving building energy efficiency and supporting reliability and resilience of the electric grid more efficiently and at a lower cost. In addition, EERE and DOE’s Office of Electricity created an initiative led by DOE and supported by the national laboratories under the Grid Modernization Lab Consortium structure to enhance grid modernization. The work reported in this document is part of the first set of projects funded under the initiative to design, develop, and validate scalable transactive control technologies for the commercial buildings sector. Transactive controls requires the ability of individual end-use loads to express flexibility as a function of a transactive signal (e.g., price). Empirical grey- and black-box models have been widely used to express flexibility. Although this approach is generally easy to construct and simple to use, it does not capture non-linear behavior that some end-use loads represent. Therefore, Pacific Northwest National Laboratory (PNNL) with support from Western Washington University conducted this research to explore the use of deep machine learning (ML) techniques. The work reported in this document is limited to forecasting whole building electricity consumption, the zone airflow and the zone temperature predictions.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2019

Deep vadose zone respiration contributions to CO2 fluxes from a semi-arid floodplain, Vadose Zone Journal: Dataset

This data package provides lists of parameter values presented in the paper “Deep vadose zone respiration contributions to CO2 fluxes from a semi-arid floodplain” by Tokunaga et al., Vadose Zone J. 2016. Each table or figure from that paper that contains numerical information is represented as a sheet within the Excel file. Table 1 lists depth profile values for particle-size, bulk density, and parameters for correlating moisture contents with matric potentials. Table 2 lists soil respiration fluxes reported in other studies of semi-arid environments. Figure 3. Presents representative relations between moisture contents with matric potentials. Figure 4 presents depth profiles on different dates at site TT03 for hydraulic head, matric head, pore space volumetric air fraction, temperature, and the effective CO2 diffusion coefficient. Figure 5a presents the time-dependence of relative water table elevation (relative to the deepest measured depth during the study), daily CO2 flux rates at the soil surface, and soil temperature at a depth of 0.20 m. Figure 5b presents continuous measurements of CO2 flux and soil temperature. Figure 6 presents depth profiles on different dates of CO2 concentrations in the gas phase at the 5 monitoring stations. Figure 7 presents CO2 surface fluxes calculated by the gradient method, comparisons between calculated and measured rates at the soil surface, CO2 fluxes at 2m depth, and the ratio of deep (2 m) to surface CO2 fluxes.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS1979

Stratospheric aerosols in the intertropical convergence zone, Panama Canal zone

To investigate whether injection sources of the stratospheric aerosol layer could be detected in the tropical stratosphere, an examination of the aerosol vertical and horizontal size distribution around the Intertropical Convergence Zone (ITCZ) at the Panama Canal Zone was performed during the summer of 1977. By comparing these data with similar measurements in temperate and polar regions, it was hoped to discover variations in particle size that would indicate whether a young aerosol is forming and entering the stratosphere at the ITCZ; where the aerosol matures; and finally, where it reenters the troposphere. The methods used in the investigations and the results obtained from the analyses are described.

Farlow, N. H.↗
NASA NTRS1984

Remote sensing of the marginal ice zone during Marginal Ice Zone Experiment (MIZEX) 83

The remote sensing techniques utilized in the Marginal Ice Zone Experiment (MIZEX) to study the physical characteristics and geophysical processes of the Fram Strait Region of the Greenland Sea are described. The studies, which utilized satellites, aircraft, helicopters, and ship and ground-based remote sensors, focused on the use of microwave remote sensors. Results indicate that remote sensors can provide marginal ice zone characteristics which include ice edge and ice boundary locations, ice types and concentration, ice deformation, ice kinematics, gravity waves and swell (in the water and the ice), location of internal wave fields, location of eddies and current boundaries, surface currents and sea surface winds.

Shuchman, R. A.↗
NASA NTRS1986

Comparison between the South Pacific Convergence Zone and South Atlantic Convergence Zone in January 1979

Using one of the FGGE data sets, the eddy potential and eddy kinetic energy budgets during the period of January 10-27, 1979 were derived for the regions containing the South Pacific Convergence Zone (SPCZ) and the South Atlantic Convergence Zone. A complete set of energy equations developed by Brennan and Vincent (1980) was partitioned into zonal and eddy components; the eddy forms of energy were derived from a grid point's departure from the zonal average over a 5-deg latitude belt. The results of the analysis indicate that the eddy kinetic energy content (KE) is greater than the eddy available potential energy content (AE) throughout the period. Both AE and KE show large losses beginning when the SPCZ enters a decaying state: AE shows a gradual but slow decrease until after January 22, when it decreases rapidly; KE oscillates, reaching a maximum on January 22 before a rapid decrease.

Vincent, Dayton G.↗