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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 433 records · Page 24
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

The achievement of the T e,div feedback control by CD 4 seeding on EAST

A multi-function divertor feedback control system has been built on Experimental Advanced Superconducting Tokamak (EAST) to treat the divertor heat load issue. With the real-time data of the Langmuir probes and the impurity seeding, the divertor electron temperature (T e,div ) is well controlled to achieve the partial detachment phase. The first trial of the CD 4 seeding for the T e,div reduction has been achieved on EAST long-pulse discharge. In the seeding phase, the T e,div was maintained close to 5 eV, and the surface temperature of the target plate (T surface,div ) had a reduction of about 150° C. The plasma stored energy had a reduction in the control phase, so it is necessary to find a way to keep the good plasma confinement in the next step. The CD 4 injection also mitigated the low hybrid wave coupling rate in some degree. The big volume of the CD 4 injection lifted the Greenwald density fraction from ~0.4 to ~0.7, which made the SOL into high recycling state. As a result, most of the injected carbon particles were in the high ionized state, and with the lower of the T e,div , the tungsten line emission was suppressed obviously.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2020

Magnetic shear effect on plasma transport at T e / T i ~ 1 through electron cyclotron heating in DIII-D plasmas

The effect of magnetic shear on plasma transport for an electron to ion temperature ratio ( T e / T i ) near unity has been explored in DIII-D utilizing electron cyclotron heating (ECH). Previous reports showed that significant confinement degradation occurred at T e / T i ~ 1 in positive shear (PS) plasmas in DIII-D, whereas reduced confinement degradation was observed in negative central shear (NCS) plasmas. In this study, plasma transport in weak magnetic shear (WS) plasmas with ECH is investigated and compared with that in NCS and PS plasmas. Here the magnetic shears ($\hat s$) are $\hat s$ > 0.5, ~0 and <-0.1 in the core region (ρ~ 0.3–0.4) of PS, WS and NCS plasmas, respectively, and flat or negative inside ρ~ 0.4 in the WS and NCS plasmas. Weak magnetic shear is found to be effective in minimizing degradation of ion thermal confinement as T e / T i increases through ECH application, and an improved confinement factor of H 98y2 ~ 1.2 is maintained, similar to NCS plasmas. At T e / T i ~ 1, the ion thermal diffusivity around an internal transport barrier decreases when changing the magnetic shear from positive to weak or negative shear. Also, reduced local particle and momentum transport was indicated by steeper density and toroidal rotation profiles in the weak and negative shear regimes. Linear gyrokinetic simulations predict little change in growth rates of low-k turbulence with ECH application in the WS and NCS plasmas, which is consistent with the transport and profile analyses.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2024

Search for baryon junctions in e+A collisions at the electron ion collider

Constituent quarks in a nucleon are the essential elements in the standard “quark model” associated with the electric charge, spin, mass, and baryon number of a nucleon. Quantum chromodynamics (QCD) describes nucleon as a composite object containing current quarks (valence quarks and sea (anti-)quarks) and gluons. These subatomic elements and their interactions are known to contribute in complex ways to the overall nucleon spin and mass. In the early development of QCD theory in the 1970s, an alternative hypothesis postulated that the baryon number might manifest itself through a non-perturbative configuration of gluon fields forming a Y-shaped topology known as the gluon junction. In this work, we propose to test such hypothesis by measuring (i) the Regge intercept of the net-baryon distributions for e+(p)Au collisions, (ii) baryon and charge transport in the isobaric ratio between e+Ru and e+Zr collisions, and (iii) target flavor dependence of proton and antiproton yields at large rapidity, transported from the hydrogen and deuterium targets in e+p(d) collisions. Our study indicates that these measurements at the EIC can help determine what carries the baryon number.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2020

PORFLOW Implementation of Vadose Zone Conceptual Model for Naval Reactor Component Disposal Areas in the E-Area Low Level Waste Facility Performance Assessment

PORFLOW models have been developed to implement the proposed conceptual models for the two Naval Reactor Component Disposal Areas (NRCDAs), 643-7E and 643-26E, for the purpose of evaluating dose impacts and producing disposal limits for the E-Area Low-Level Facility (LLWF). New NRCDA conceptual models were proposed by Wohlwend and Butcher (2019) for two areas within/adjacent to the E-Area LLWF used as storage/disposal sites for reactor components from the U.S. Navy since 1987. Naval Reactor (NR) waste is comprised of highly radioactive components consisting of activated corrosion-resistant metal alloy contained within welded thick-walled steel casks, and auxiliary equipment primarily contaminated with lower levels of Activated Corrosion Products (ACPs) residing on the metal surfaces and contained within thinner-walled bolted containers.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2022

PORFLOW Implementation of Vadose Zone Conceptual Model for Naval Reactor Component Disposal Area in the E-Area Low Level Waste Facility Performance Assessment

PORFLOW models have been developed to implement the proposed conceptual models for the two Naval Reactor Component Disposal Areas (NRCDAs), 643-7E and 643-26E, for the purpose of evaluating dose impacts and producing disposal limits for the E-Area Low-Level Facility (LLWF). New NRCDA conceptual models were proposed by Wohlwend and Butcher (2019) for two areas within/adjacent to the E-Area LLWF used as storage/disposal sites for reactor components from the U.S. Navy since 1987. Naval Reactor (NR) waste is comprised of highly radioactive components consisting of activated corrosion-resistant metal alloy contained within welded thick-walled steel casks, and auxiliary equipment primarily contaminated with lower levels of Activated Corrosion Products (ACPs) residing on the metal surfaces and contained within thinner-walled bolted containers.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2025

TEAMER Technical Support on Biofouling and Corrosion for E-Wave Technologies LLC Novel (Abstract)

National Technology & Engineering Solutions of Sandia (NTESS) in collaboration with the Pacific Northwest National Laboratory (PNNL), and with guidance from E-Wave, will assess corrosion and biofouling challenges specific to E-Wave’s innovative WEC designed to retrofit into and power existing aquaculture farm infrastructure from ocean waves. The teams will examine coatings via a static raw seawater test and determine the efficacy of coatings for E-Wave’s applications. Samples will include panels of materials provided by E-Wave and coated with three different paint treatments. Fouling will be determined using a staining technique followed by photographic analysis to evaluate fouling intensity on the surface. Materials will also be weighed before and after submersion to facilitate weight change analysis resulting from fouling organisms aggregating on the materials.

16 TIDAL AND WAVE POWER↗
DOE OSTI2025

ML-driven Strong Lens Discoveries: Down to θ E ~ $0^{_{''}}_{^.}03$ and M halo < 10 11 M ⊙

We present results on extending the strong lens discovery space down to much smaller Einstein radii ( θ E ≲ $0^{_{''}}_{^.}03$) and much lower halo mass (M halo < 10 11 M ⊙ ) through the combination of JWST observations and machine learning (ML) techniques. First, we forecast detectable strong lenses with JWST using CosmoDC2 as the lens catalog, and a source catalog down to 29th magnitude. By further incorporating the VELA hydrodynamical simulations of high-redshift galaxies, we simulate strong lenses. We train a ResNet on these images, achieving near-100% completeness and purity for “conventional” strong lenses ( θ E ≳ $0^{_{''}}_{^.}05$), applicable to JWST, the Hubble Space Telescope (HST), the Roman Space Telescope, and Euclid VIS. For the first time, we also search for very low halo mass strong lenses (M halo < 10 11 M ⊙ ) in simulations, with θ E << $0^{_{''}}_{^.}05$, down to the best resolution ($0^{_{''}}_{^.}03$) and depth (10,000 s) limits of JWST using ResNet. A U-Net model is employed to pinpoint these small lenses in images, which are otherwise virtually impossible for human detection. Our results indicate that JWST can find ∼17/deg 2 such low-halo-mass lenses, with the locations of ∼1.1/deg 2 of these detectable by the U-Net at ∼100% precision (and ∼7.0/deg 2 at a 99.0% precision). To validate our model for finding “conventional” strong lenses, we apply it to HST images, discovering two new strong lens candidates previously missed by human classifiers in a crowdsourcing project (E. O. Garvin et al. 2022). This study demonstrates the (potentially “superhuman”) advantages of ML combined with current and future space telescopes for detecting conventional, and especially, low-halo-mass strong lenses, which are critical for testing cold dark matter models.

Silver, Ethan [Harvard University, Cambridge, MA (↗
NASA NTRS1973

Energetic electrons in the midlatitude nighttime E region

Nike Apache 14.439 was launched from Wallops Island at 0003 EST on 1 November 1972, a very disturbed night (K sub P = 8). A Geiger counter in the payload detected electrons ( keV) with a maximum flux of 1086 + or -261/sq cm/sec/ster. The height-averaged ionization rate in the upper E region is calculated from the measured electron density profile and has a value of 35 1/cu/cm/sec. The ionization rate can be reconciled with the observed flux of electrons ( 70 2 keV) if the spectrum ( keV) is of the form J ( E) = J sub O exp(-E/E sub O) with E sub O equal to 8.3 keV. The ionization rate on this and other nights is found to be strongly dependent on geomagnetic activity. It is suggested that energetic electrons are the principal source of ionization at midlatitudes in the upper E region near midnight, even under rather quiet geomagnetic conditions.

Smith, L. G.↗
NASA NTRS1977

The E asteroids and the origin of the enstatite achondrites

Color, polarization, and albedo data are summarized for the three known minor planets of optical type E: 44 Nysa, 64 Angelina, and 434 Hungaria. The inventory of E asteroids with dimensions in excess of 50 km is shown to be essentially complete. The surfaces of the E objects evidently consist of colorless translucent iron-free silicates such as plagioclase, forsterite, or enstatite. Their possible identification as the source of enstatite achondrites is consistent with laboratory polarimetry of the Norton County aubrite. Both Nysa and Hungaria seem to be rather favorably situated for the production of meteorites. Nysa has a highly aspherical shape and is dynamically associated with the metal-rich asteroid 135 Hertha and several small objects also apparently of the metal-depleted E type. The configuration is suggestive of the fragments of a differentiated parent body, in which Hertha originated as the iron core and Nysa as the largest surviving mantle fragment. The relative volumes, however, are not consistent with simple igneous differentiation from a chondritic composition.

Zellner, B.↗
NASA NTRS1979

Report of the mid- and low-latitude E and F Region Working Group

The formation and variation of the ionosphere is addressed with regard to the ability to understand, specify, and predict the low and mid latitude E and F regions. A brief survey of prediction methods and techniques is given for long and short term variability in the E and F regions. It is indicated that the usefulness of theoretical models to predict electron density distribution in the low and mid latitude ionospheric E and F regions is limited by the ability to predict the parameters which enter the relevant equations; i.e., neutral atmospheric constituents, neutral and charged particle temperatures, neutral wind, electric fields, and ionizing sources such as solar (E sub uv) radiation and energetic particles. It is recommended that areas for research include improving knowledge of the input parameters and how they respond to changing solar and geophysical conditions.

Rush, C. M.↗
NASA NTRS1982

The negative gravity field over the 85 deg E ridge

Two north-south ridges in the basement topography of the Bay of Bengal may be observed on an isopach map at 85 and at 90 deg E. Free-air gravity anomaly profiles across the region show a strong gravity low (about -60 mGal) over the 85 deg E ridge, and a gravity high over the other. Using a simple two-stage loading model, the negative gravity anomaly over the 85 deg E ridge is explained as a direct consequence of sediment loading, and the flexural rigidity of the lithosphere when the ridge was formed is estimated to have been about 180 times less than the flexural rigidity during the sediment loading. An approximate relationship between flexural rigidity and crustal age shows that the 85 deg E ridge was formed on relatively young lithosphere, 5-15 million years old, and that it was buried when the lithosphere was 40-80 million years old. The alteration of the gravity field by a thick layer of sediments may occur in other large sedimentary basins or along continental margins.

Liu, C.-S.↗
NASA NTRS1984

Effect of dietary vitamin E or selenium on prostaglandin dehydrogenase in hyperoxic rat lung

Weanling male rats were fed semipurified diets supplemented with 0, 60, or 600 IU/kg vitamin E or 0, 100, or 1000 ppb selenium. One group was injected daily with vitamin E at a rate equivalent to consumption of 60 IU/kg. Animals from all groups were sacrificed after exposure to normobaric oxygen or air for 48 h. Lung tissue was analyzed for the combined activity of prostaglandin dehydrogenase and reductase. Using the decline in enzyme activity as an indicator of susceptibility to oxygen poisoning, protection against hyperoxia was directly related to the level of vitamin E supplementation. Selenium supplemented at 100 ppb provided significant protection when compared to 0 ppb or 1000 ppb. The latter dose may have been marginally toxic. Thus dietary supplementation of vitamin E and selenium may influence the relative susceptibility of an animal to pulmonary oxygen poisoning.

North, L. N.↗
NASA NTRS1987

Meteor matter interaction with the Earth's atmosphere and the ionospheric E-region structure

The exploration of the ionospheric E region is a pressing problem, both in the applied and fundamental studies. Results are presented of an investigation: (1) to estimate the meteor ionization contribution to the night time E layer and influx; (2) to study the phenomenon of intensive sporadic layer formation following cessation of meteor stream activity; and (3) to access the role of metallic ions of meteor origin in the diurnal and seasonal variations in the occurrence probabilities of midlatitude E sub s. The contribution was evaluated of meteor matter, Lyman radiation and corpuscular particles to the electron concentration of the night E region. Results are discussed.

Alimov, O.↗
NASA NTRS1991

Observations of ion-neutral collisional effects in the auroral E region

Thermal ion energy distribution functions and local electric and magnetic fields were directly measured for the first time in the ionospheric E region. Measured ion distribution functions were fitted to shifted Maxwellian distributions, and their resulting ion drift velocities were compared with E x B/B-squared velocities from the double-probe electric field observations. The results show that the ion drift direction rotates with respect to the local electric field direction and that the ratio of the magnitudes of the ion velocity to the E x B/B-squared velocity decreases with decreasing altitudes. Using these observations, the quiet time ion-neutral collison frequencies and neutral wind velocities were estimated and found to be consistent with theoretical estimates. However, significant discrepancies between observations and theory are found in the disturbed E region near auroral particle precipitation regions. These data indicate that the auroral atmosphere is significantly perturbed due to Joule as well as particle heating effects.

Watanabe, S.↗
NASA NTRS1992

Comparison of measured and modeled solar EUV flux and its effect on the E-F1 region ionosphere

Two different photochemical schemes are used to investigate the response of the E-F1 region ionosphere to different solar EUV flux models, and the results are compared with incoherent scatter radar electron density measurements taken at Millstone Hill. The latest EUV flux model (Tobiska, 1991), which incorporates more recent measurements, has generally more flux at short wavelengths compared to the Hinteregger et al. (1981) flux model based on AE-E satellite data. This results in better agreement with the measurements in the E-F1 region and above. The Tobiska flux model gives a smaller E region peak density, due to the influence of low Ly-beta flux in the November 10, 1988 rocket measurements of Woods and Rottman (1990). The photoionization and photoabsorption cross sections of Conway (1988) give results in somewhat better agreement with observations than the cross sections of Torr et al. (1979). For the zenith angles considered (daytime conditions), the Chapman function method for calculating photoabsorption yields results in satisfactory agreement with a more rigorous calculation method using a formula from Rees (1989).

Buonsanto, M. J.↗
NASA NTRS1994

Phase E in a water-saturated peridotite system at 9.3 GPa

The stability of hydrous phases in a natural upper mantle system has been investigated at 9.3 GPa using a gel of KLB-1 peridotite composition with brucite which contains 14 wt. percent (30 atom. percent) water. No hydrous mineral was found at 950 (+150 -50) degree C. At 800 degree C, an assemblage of phase A, phase E, enstatite, clinohumite, and garnet is obtained. Although there is a significant thermal gradient over the sample, phase E is found to be surrounded by phase A in the lower temperature part. Electron probe analyses show that phase E has 35.5 SiO2, 4.4 Al2O3, 41.1 MgO and 8.5 wt. percent FeO* (Mg value is 90) with an oxide sum of 89.7 wt. percent, and possesses a stoichiometry similar to that proposed by Kanzaki. CaO and TiO2 are both less than 0.1 wt. percent. Coexisting phase A has 0.5 wt. percent CaO but only 0.4 wt. percent Al2O3 concentration. Phase A coexists with only enstatite in the water-saturated MgO-FeO-SiO2 system at 800 degree C and 9.3 GPa as well as the results in the water-saturated MgO-SiO2 system. Therefore it is suggested that the addition of Al2O3 expands the stability field of phase E to lower than 13 - 17 GPa in the water-saturated MgO-SiO2 system.

Kawamoto, Tatsuhiko↗
NASA NTRS1961

Sporadic-E As Observed with Rockets

Data obtained with rockets flown over New Mexico, U.S.A. and Manitoba, Canada have always shown the sporadic-E layer to be a thin layer with a large electron density gradient. The vertical electron density profiles and the horizontal uniformity of the sporadic-E layer are discussed herein. These layers have a strong tendency to form at preferential altitudes separated by approximately 6 km, and a striking correlation exists with wind- shears and magnetic field variations. In two cases where comparisons with ionograms were possible, the minimum frequency of the F-region echoes was found approximately equal to the plasma frequency of the sporadic-E layer reduced by half the gyrofrequency. On the other hand, the maximum frequency of the sporadic-E echoes as noted on ionograms was sometimes as much as 1 to 2 Mc greater than the plasma frequency.

Seddon, J. Carl↗
NASA NTRS2001

External Data and Attribute Hyperlink Programs for Promis*e(Registered Trademark)

External Data and Attribute Hyperlink are computer programs that can be added to Promis*e(trademark) which is a commercial software system that automates routine tasks in the design (including drawing schematic diagrams) of electrical control systems. The programs were developed under the Stennis Space Center's (SSC) Dual Use Technology Development Program to provide capabilities for SSC's BMCS configuration management system which uses Promis*e(trademark). The External Data program enables the storage and management of information in an external database linked to a drawing. Changes can be made either in the database or on the drawing. Information that originates outside Promis*e(trademark) can be stored in custom fields that can be added to the database. Although this information is not available in Promis*e(trademark) printed drawings, it can be associated with symbols in the drawings, and can be retrieved through the drawings when the software is running. The Attribute Hyperlink program enables the addition of hyperlink information as attributes of symbols. This program enables the formation of a direct hyperlink between a schematic diagram and an Internet site or a file on a compact disk, on the user's hard drive, or on another computer on a network to which the user's computer is connected. The user can then obtain information directly related to the part (e.g., maintenance, or troubleshooting information) associated with the hyperlink.

Derengowski, Rich↗