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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
DOE OSTI2016

Marine Ice Nuclei Collections – MAGIC (MAGIC-IN) Final Campaign Summary

This campaign augmented measurements obtained via deployment of the Atmospheric Radiation Measurement (ARM) Climate Research Facility’s ARM Mobile Facility (AMF) in the Marine ARM GPCI1 Investigation of Clouds (MAGIC) field campaign. The measurements, comprised of shipboard aerosol collections obtained during the five legs of the summer 2013 cruises, were sent for offline processing to measure ice nucleating particle (INP) number concentrations. The forty-three sample periods each represented, nominally, 24-hour segments during outbound and inbound transits of the Horizon Spirit. The samples were collected at locations between Los Angeles and Hawaii. Eight samples have been analyzed for immersion freezing temperature spectra thus far, using funding from other grants. Remaining samples are being frozen until support for further processing is obtained. Future analyses will investigate the inorganic/organic proportions of ice nuclei, in addition to determining the genetic composition of the overall biological community associated with INPs. Resulting correlations will be compared with other archived aerosol quantities, meteorological and ocean data (e.g., temperature, wind speed, sea surface temperature, etc…) and satellite ocean color products. These findings will ultimately aid in parameterizing oceanic (e.g., sea spray) INP emissions in regional and global scale models, when illustrating aerosol connections to cloud phases and properties. Independent future analyses of frozen filter samples, as proposed by collaborating investigators at the time of this report, will include single particle analyses of marine boundary layer aerosol compositions and morphology. The MAGIC-IN data are considered representative of the oligotrophic, low Chlorophyll-a (with the exception of near-shore) ocean regions, which exist along the MAGIC transect. Current analyses suggest that INP numbers in the marine boundary layer over this region are typically low, compared to existing measurements over marine areas and those collected in the laboratory as the result of realistic sea spray particle generation. These findings, along with separate studies, confirm the existence of highly variable emission sources for INP from oceans, (though weaker than land-based emissions at modestly cooled temperatures).

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Detector calibration using through going and stopping muons in the MicroBooNE LArTPC

The MicroBooNE experiment at Fermilab uses a liquid argon time projection chamber (LArTPC) in the Booster Neutrino Beam to search for anomalous production of electron-neutrino-like events and to study neutrino-argon cross sections in the 1 GeV neutrino energy regime. The detector operates at 0.273 kV/cm drift electric field and its TPC has an active mass of 85 tons of liquid argon. One of the main advantages of the LArTPC technology is its ability to reconstruct both particle track direction and energy with very high precision. Effects such as misconfigured or cross-connected TPC wires, space charge effects, electron attenuation, diffusion, and recombination can worsen the energy resolution of the detector. Therefore the detector calibration is of utmost importance to get the correct dE/dx (energy loss per unit track length) measurement. This is crucial for particle identification and in particular the separation of electrons and photons, essential for oscillation analyses. Here we describe a method developed for MicroBooNE to calibrate the detector by correcting for the above mentioned effects. In this analysis first we make the detector response uniform throughout the detector and time using through-going muons. Next stopping muons are used to determine the energy scale and convert dQ/dx to dE/dx.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2022

MeV–GeV Gamma-Ray Emission from SNR G327.1–1.1 Discovered by the Fermi-LAT

Abstract We report the discovery of MeV–GeV γ -ray emission by the Fermi-LAT positionally coincident with the TeV pulsar wind nebula (PWN) HESS J1554–550 within the host supernova remnant (SNR) G327.1–1.1. The γ -ray emission is point-like and faint but significant (>4 σ ) in the 300 MeV–2 TeV energy range. We report here the Fermi-LAT analysis of the observed γ -ray emission followed by a detailed multiwavelength investigation to understand the nature of the emission. The central pulsar powering the PWN within G327.1–1.1 has not been detected in any wave band; however, it is likely embedded within the X-ray nebula, which is displaced from the center of the radio nebula. The γ -ray emission is faint and therefore a pulsation search to determine if the pulsar may be contributing is not feasible. Prior detailed multiwavelength reports revealed an SNR system that is old, τ ∼ 18,000 yr, where the interaction of the reverse shock with the PWN is underway or has recently occurred. We find that the γ -ray emission agrees remarkably well with a detailed broadband model constructed in a prior report based on independent hydrodynamical and semianalytic simulations of an evolved PWN. We further investigate the physical implications of the model for the PWN evolutionary stage incorporating the new Fermi-LAT data and attempt to model the distinct particle components based on a spatial separation analysis of the displaced PWN counterparts.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2016

Operation of the Airmodus A11 nano Condensation Nucleus Counter at various inlet pressures and various operation temperatures, and design of a new inlet system

Measuring sub-3 nm particles outside of controlled laboratory conditions is a challenging task, as many of the instruments are operated at their limits and are subject to changing ambient conditions. In this study, we advance the current understanding of the operation of the Airmodus A11 nano Condensation Nucleus Counter (nCNC), which consists of an A10 Particle Size Magnifier (PSM) and an A20 Condensation Particle Counter (CPC). The effect of the inlet line pressure on the measured particle concentration was measured, and two separate regions inside the A10, where supersaturation of working fluid can take place, were identified. The possibility of varying the lower cut-off diameter of the nCNC was investigated; by scanning the growth tube temperature, the range of the lower cut-off was extended from 1–2.5 to 1–6 nm. Here we present a new inlet system, which allows automated measurement of the background concentration of homogeneously nucleated droplets, minimizes the diffusion losses in the sampling line and is equipped with an electrostatic filter to remove ions smaller than approximately 4.5 nm. Lastly, our view of the guidelines for the optimal use of the Airmodus nCNC is provided.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

RETRACTED: Proteasome storage granules protect proteasomes from autophagic degradation upon carbon starvation

26S proteasome abundance is tightly regulated at multiple levels, including the elimination of excess or inactive particles by autophagy. In yeast, this proteaphagy occurs upon nitrogen starvation but not carbon starvation, which instead stimulates the rapid sequestration of proteasomes into cytoplasmic puncta termed proteasome storage granules (PSGs). Here, we show that PSGs help protect proteasomes from autophagic degradation. Both the core protease and regulatory particle sub-complexes are sequestered separately into PSGs via pathways dependent on the accessory proteins Blm10 and Spg5, respectively. Modulating PSG formation, either by perturbing cellular energy status or pH, or by genetically eliminating factors required for granule assembly, not only influences the rate of proteasome degradation, but also impacts cell viability upon recovery from carbon starvation. PSG formation and concomitant protection against proteaphagy also occurs in Arabidopsis , suggesting that PSGs represent an evolutionarily conserved cache of proteasomes that can be rapidly re-mobilized based on energy availability.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS1971

A study of the dry heat resistance of naturally occurring organisms widely dispersed on a surface

Although Bacillus subtilis var. niger is the standard test organism for NASA planetary quarantine sterilization studies, it was found that some naturally occurring soil organisms are more heat resistant. The separation of these organisms from soil particles is described. Experiments are discussed which were designed to show that the heat resistance is a natural characteristic of the organisms, rather than a condition induced by the clumping effect of agglomerated particles and organisms.

Garst, D. M.↗
NASA NTRS1980

Ultraviolet observations of 31 and 32 Cygni

Some observations of 31 and 32 Cygni, started in September 1978, at phases 0.62 and 0.17, respectively, are presented. The UV spectrum of 32 Cyg is described both qualitatively and quantitatively. Numerous lines of Si II, O I, C II, Al II and III and Fe II appear with P Cygni characteristics. The LWR-2275 image is dominated by the Mg II 2800 A resonance doublet and numerous Fe II lines in the 2200 - 2700 A region, all showing P Cygni profiles. More quantitatively, ionization modeling for the B star environs was made by comparing observed and computed equivalent widths to deduce density, temperature and turbulence values. At the projected separation between the stars, the log particle density obtained was 7.2, neglecting dust and molecule formation.

Stencel, R. E.↗
NASA NTRS1983

Further analysis of a recent cosmic-ray antiproton experiment

Reference is made to the measurements of a cosmic ray antiproton flux at a few hundred MeV reported by Buffington et al. (1981), noting that one of the final background processes to be removed by the data analysis in that study was helium-induced events which satisfied the criteria for topology and timing. The response in the third scintillator S3 was used to identify and remove these events. For the top two scintillators S1 and S2, pulse size information was lost during the data-taking. A method is reported here for the partial retrieval of pulse size information for the scintillator S2. This is possible because a portion of this signal was subtracted from the Cerenkov response before trigger discrimination and data recording to remove scintillation from the Cerenkov response. For separating protons from more highly charged particles, the method is considered sufficient. It is pointed out that the sample of events identified as antiprotons, for which the method can be applied, has the expected unit charge in scintillator S2.

Buffington, A.↗
NASA NTRS1985

Multispacecraft observations of the east-west asymmetry of solar energetic storm particle events

Energetic proton observations have been obtained by instruments aboard the IMP-7 and -8 spacecraft and Voyager-1 and -2 deep space probes, in order to study the generation of solar flare Energetic Storm Particle Events (ESP) events at widely separated locations on the same shock front which are presumably characterized, on average, by different IMF shock front configurations for solar flare sites. Energetic proton observations indicate that substantial differences in the ESP proton intensity enhancements are detected at these energies for locations on the shock front with wide heliolongitude separations. The present results indicate that acceleration of ESP protons to more than 500 keV takes place at the quasi-perpendicular shock front domain, consistent with the 'shock drift' acceleration mechanism.

Sarris, E. T.↗
NASA NTRS1989

Radiation pressure dynamics in planetary exospheres - A 'natural' framework

Exospheric theory is reformulated to provide for the analysis of dynamical underpinning of exospheric features. The formulation is based on the parabolic-cylindrical separability of the Hamiltonian that describes particle motions in the combined fields of planetary gravity and solar radiation pressure. An approximate solution for trajectory evolution in terms of orbital elements is derived and the role of the exopause in the tail phenomenon is discussed. Also, an expression is obtained for the bound constituent atom densities at outer planetocoronal positions along the planet-sun axis for the case of an evaporative, uniform exobase. This expression is used to estimate midnight density enhancements as a function of radial distance for the terrestrial planets.

Bishop, James↗
NASA NTRS1989

Age structure of refractory interstellar dust and isotopic consequences

A sputtering and recycling Monte Carlo model, developed by Liffman and Clayton (1988) is used to calculate the distribution of existence times of the matter in interstellar dust composed of refractory metals. The mean age of each dust particle is defined not as the time it has existed but rather as the mass-weighted existence times of its parts at t = 6 Gyr of the modeled solar system formation. It is shown that Galactic evolution generates a mean correlation, applying to large numbers of particles binned according to size rather than according to individual particles, whose mean ages fluctuate statistically. The cosmochemical consequence is that if interstellar particles can be dynamically sorted into separate size populations during the aggregation history of solar system bodies, the collections of larger grains will constitute matter that is chemically older than collections of smaller grains. The macroscopic age difference generates isotopic anomalies by virtue of the time dependence of the secondary/primary nucleosynthesis yields. Results are compared with three different prescriptions for the sputtering of interstellar dust.

Clayton, Donald D.↗
NASA NTRS1993

Solar noble gases revealed by closed system stepped etching of a metal separate from Fayetteville

Solar He, Ne, and Ar in a Fe-Ni separate from the chondrite Fayetteville are analyzed by closed system stepped oxidation. We report here data of the first 15 steps comprising 55 percent of the total solar gases. He-4/Ar-36 and Ne-20/Ar-36 are quite constant at values about 20 percent below those of present day solar wind (SWC). In this, Fe-Ni differs from lunar ilmenites where He-4/Ar-36 and Ne-20/Ar-36 in the first steps are several times below SWC. Thus, metal retains SW-noble gases even better than ilmenite, almost without element fractionation. Nevertheless, the isotopic composition of SW-He, -Ne, and -Ar in the first steps of the metal sample are identical to those found in a recently irradiated lunar ilmenite, indicating that ilmenites and chondritic metal both contain isotopically unfractionated SW noble gases. A preliminary analysis of a smaller Fayetteville metal separate shows Ne from solar energetic particles (SEP-Ne) with Ne-20/Ne-22 less than or equal to 11.5.

Murer, CH.↗
NASA NTRS1994

Voyager observations of O(+6) and other minor ions in the solar wind

The plasma science (PLS) experiments on the Voyager 1 and 2 spacecraft began making measurements of the solar wind shortly after the two launches in the fall of 1977. In reviewing the data obtained prior to the Jupiter encounters in 1979, we have found that the large dynamic range of the PLS instrument generally allows a clean separation of signatures of minor ions (about 2.5% of the time) during a single instrument scan in energy per charge. The minor ions, most notably O(+6), are well separated from the protons and alpha particles during times when the solar wind Mach number (ratio of streaming speed to thermal speed) is greater than approximately 15. During the Earth to Jupiter cruise we find that the average ratio of alpha particle number density to that of oxygen is 66 +/- 7 (Voyager 1) and 71 +/- 17 (Voyager 2). These values are consistent with the value 75 +/- 20 inferred from the Ion Composition Instrument on ISEE 3 during the period spanning 1978 and 1982. We have inferred an average coronal temperature of (1.7 +/- 0.1) x 10(exp 6) K based on the ratio of O(+7) to O(+6) number densities. Our observations cover a period of increasing solar activity. During this time we have found that the alpha particle to proton number density ratio is increasing with the solar cycle, the oxygen to proton ratio increases, and the alpha particle to oxygen ratio remains relatively constant in time.

Villanueva, Louis↗
NASA NTRS1995

Thermal emission from particulate surfaces: A comparison of scattering models with measured spectra

Emissivity spectra of particulate mineral samples are highly dependent on particle size when that size is comparable to the wavelength of light emitted (5-50 micrometers for the midinfrared). Proper geologic interpretation of data from planetary infrared spectrometers will require that these particle size effects be well understood. To address this issue, samples of quartz powders were produced with narrow, well-characterized particle size distributions. Mean particle diameters in these samples ranged from 15 to 227 micrometers. Emission spectra of these powders allow the first detailed comparison of the complex spectral variations with particle size observed in laboratory data with the predictions of radiative transfer models. Four such models are considered here. Hapke's relectance theory (converted to emissivity via Kirchoff's law) is the first model tested. Hapke's more recently published emission theory is also employed. The third model, the 'Mie/Conel' model, uses Mie single scattering with a two-stream approximation for multiple scattering. This model, like the first, is a converted reflec- tance model. Mie scattering assumes particles are both spherical and well separated, which is not true for the quartz powders, but includes diffraction effects. The fourth model uses the Mie solution for single scattering by spheres and inputs those results into the multiple scattering formalism of Hapke's emission theory. The results of the four models are considered in relation to the values of the optical constants n and k. We have grouped these as class 1 (k large), class 2 (k moderate, n is approximately 2), class 3 (k small, n is approximately 2), and class 4 (k small, n is approximately 1). In general, the Mie/Hapke hybrid model does best at predicting variations with grain size. In particular, it predicts changes of the correct pattern, although incorrect magnitude, for class 1 bands, where large increases in emissivity with decreasing grain size are observed. This model also does an excellent job on moderate (class 2) and very weak and intraband (class 3) regions, and correctly predicts the emission maximum and its invariance with grain size near the Christiansen frequency (class 4). The Mie/Hapke hybrid model also has the fewest free parameters of the four models examined, while maintaining the most physical treatment of the radiative transfer. The Mie/Conel model performs as well as the Mie/Hapke hybrid model in strong bands (class 1) but does not accurately model the behavior of moderate (class 2) and very weak (class 3) bands.

Moersch, J. E.↗
NASA NTRS1994

Weightless bubble lattices: A case of froth wicking

In the absence of gravity drainage, froth wicking draws excess fluid onto a bubble lattice. Capillary forces only cause fluid transport; a moving front moves stably and without fluid fingering along a constant velocity bubble-fluid contact line. This percolation of fluid crawling up the lattice shows fluid coverage on lattice borders varies linearly with available surface area (proportional to lattice perimeter) and fluid accelerates through regions or nests of high bubble density (number of bubbles/sq cm). The development of nearly two-dimensional bubble lattices in variable gravity (step function between 0.01 and 1.8 times earthly gravity) are examined experimentally and a zeroth-order model for froth wetting is presented, which captures many of the principal observations. Possible applications for bubble lattices include adhesion casting of metals and separation of biological cells, bacteria, and particles.

Noever, David A.↗
NASA NTRS1996

The 27-28 October 1986 FIRE IFO Cirrus Case Study: Cloud Optical Properties Determined by High Spectral Resolution Lidar

During the First ISCCP Region Experiment (FIRE) cirrus intensive field observation (IFO) the High Spectral Resolution Lidar was operated from a roof top site on the University of Wisconsin-Madison campus. Because the HSRL technique separately measures the molecular and cloud particle backscatter components of the lidar return, the optical thickness is determined independent of particle backscatter. This is accomplished by comparing the known molecular density distribution to the observed decrease in molecular backscatter signal with altitude. The particle to molecular backscatter ratio yields calibrated measurements of backscatter cross sections that can be plotted ro reveal cloud morphology without distortion due to attenuation. Changes in cloud particle size, shape, and phase affect the backscatter to extinction ratio (backscatter-phase function). The HSRL independently measures cloud particle backscatter phase function. This paper presents a quantitative analysis of the HSRL cirrus cloud data acquired over an approximate 33 hour period of continuous near zenith observations. Correlations between small scale wind structure and cirrus cloud morphology have been observed. These correlations can bias the range averaging inherent in wind profiling lidars of modest vertical resolution, leading to increased measurement errors at cirrus altitudes. Extended periods of low intensity backscatter were noted between more strongly organized cirrus cloud activity. Optical thicknesses ranging from 0.01-1.4, backscatter phase functions between 0.02-0.065 sr (exp -1) and backscatter cross sections spanning 4 orders of magnitude were observed. the altitude relationship between cloud top and bottom boundaries and the cloud optical center altitude was dependent on the type of formation observed Cirrus features were observed with characteristic wind drift estimated horizontal sizes of 5-400 km. The clouds frequently exhibited cellular structure with vertical to horizontal dimension ratios of 1:5-1:1.

Grund, C. J.↗
NASA NTRS2005

Twenty-First Century Research Needs in Electrostatic Processes Applied to Industry and Medicine

From the early century Nobel Prize winning (1923) experiments with charged oil droplets, resulting in the discovery of the elementary electronic charge by Robert Millikan, to the early 21st century Nobel Prize (2002) awarded to John Fenn for his invention of electrospray ionization mass spectroscopy and its applications to proteomics, electrostatic processes have been successfully applied to many areas of industry and medicine. Generation, transport, deposition, separation, analysis, and control of charged particles involved in the four states of matter: solid, liquid, gas, and plasma are of interest in many industrial and biomedical processes. In this paper, we briefly discuss some of the applications and research needs involving charged particles in industrial and medical applications including: (1) Generation and deposition of unipolarly charged dry powder without the presence of ions or excessive ozone, (2) Control of tribocharging process for consistent and reliable charging, (3) Thin film (less than 25 micrometers) powder coating and Powder coating on insulative surfaces, (4) Fluidization and dispersion of fine powders, (5) Mitigation of Mars dust, (6) Effect of particle charge on the lung deposition of inhaled medical aerosols, (7) Nanoparticle deposition, and (8) Plasma/Corona discharge processes. A brief discussion on the measurements of charged particles and suggestions for research needs are also included.

Mazumder, M. K.↗
DOE OSTI2014

Process and targets for production of no-carrier-added radiotin

One embodiment of the present invention includes a process for production and recovery of no-carrier-added radioactive tin (NCA radiotin). An antimony target can be irradiated with a beam of accelerated particles forming NCA radiotin, followed by separation of the NCA radiotin from the irradiated target. The target is metallic Sb in a hermetically sealed shell. The shell can be graphite, molybdenum, or stainless steel. The irradiated target can be removed from the shell by chemical or mechanical means, and dissolved in an acidic solution. Sb can be removed from the dissolved irradiated target by extraction. NCA radiotin can be separated from the remaining Sb and other impurities using chromatography on silica gel sorbent. NCA tin-117m can be obtained from this process. NCA tin-117m can be used for labeling organic compounds and biological objects to be applied in medicine for imaging and therapy of various diseases.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗