Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Alpha 5”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS1987

The 1 May 1982 stellar occultation by Uranus and the rings Observations from Mount Stromlo Observatory

The Klemola et al. (1981) object KME 15 has been observed by the Mount Stromlo 1.9-m telescope during its occultation by the Uranian rings on May 1, 1982. In addition to deriving accurate midtimes for rings 6, 5, 4, alpha, beta, eta, gamma, delta, and epsilon, on the basis of model fits to the immersion and emersion ring profiles, normal optical depths and equivalent widths are obtained for all save ring 6. The numerical inversion of immersion and emersion atmosphere occultation values has yielded vertical temperature profiles that exhibit mean temperatures in the vicinity of 130 K and a local maximum near the 8-microbar pressure level.

French, Richard G.↗
NASA NTRS1987

The occultation of KME 17 by Uranus and its rings

K-filter/InSb observations of the March 25, 1983 occultation of KME 17 by Uranus and its rings yielded nonchopping-mode recordings of the immersion of the nine main rings and the emersion of rings 5, 4, alpha, and beta; a diffracted square-well model has been fitted to these data in order to derive the midtime, width, and equivalent depth for each profile, in view of a profile model encompassing the diameter of the occulted star as a free parameter. Assuming a fully darkened disk, the angular diameter of KME 17 is 0.096 + or - 0.005 milliarcsec. Attention is also given to JHKL-band photometry for both KME 17 and other Uranian-ring-occulted stars.

Elliot, J. L.↗
NASA NTRS2005

Hot Chips and Hot Interconnects for High End Computing Systems

I will discuss several processors: 1. The Cray proprietary processor used in the Cray X1; 2. The IBM Power 3 and Power 4 used in an IBM SP 3 and IBM SP 4 systems; 3. The Intel Itanium and Xeon, used in the SGI Altix systems and clusters respectively; 4. IBM System-on-a-Chip used in IBM BlueGene/L; 5. HP Alpha EV68 processor used in DOE ASCI Q cluster; 6. SPARC64 V processor, which is used in the Fujitsu PRIMEPOWER HPC2500; 7. An NEC proprietary processor, which is used in NEC SX-6/7; 8. Power 4+ processor, which is used in Hitachi SR11000; 9. NEC proprietary processor, which is used in Earth Simulator. The IBM POWER5 and Red Storm Computing Systems will also be discussed. The architectures of these processors will first be presented, followed by interconnection networks and a description of high-end computer systems based on these processors and networks. The performance of various hardware/programming model combinations will then be compared, based on latest NAS Parallel Benchmark results (MPI, OpenMP/HPF and hybrid (MPI + OpenMP). The tutorial will conclude with a discussion of general trends in the field of high performance computing, (quantum computing, DNA computing, cellular engineering, and neural networks).

Saini, Subhash↗
DOE OSTI2019

BUILDING 9201-5

Building 9201-5 (Alpha-5) functioned as a uranium enrichment facility during World War II and furthered the plant's mission of producing enriched uranium for the atomic bomb. As an Alpha processing facility associated with the Manhattan Project, Building 9201-5 aided in the development of wholly new technology and substantially advanced the field of nuclear science. In terms of facility planning, project engineers originally designed all Alpha and Beta buildings with "zero tolerance" for building movement or settling as the successful operation of the Y-12 Plant's calutrons depended on absolute structural stability. After World War II, the building was used in the plant’s COLEX process of the 1950s which separated the element Lithium-6 (Li-6). This was an important component in the manufacture of hydrogen bombs and the COLEX process is of notable significance in Cold War history. Building 9201-5 is eligible for inclusion in the National Register.

96 KNOWLEDGE MANAGEMENT AND PRESERVATION↗
NASA NTRS1994

Upper limits on metals in quasar Lyman-alpha forest clouds: Absence of C 5 lines in echelle spectra

Recently Lu presented tentative evidence for C IV lines in Quasi-Stellar Object (QSO) Ly-alpha forest systems with strong lines. We have performed a similar search for C IV in our 10 km/s resolution echelle spectra of the bright QSO HS 1946+7658. We shifted the spectra to align the expected positions of the C IV lines in 65 Ly-alpha systems and then added them. The resulting composite spectrum, equivalent to 390 hr of exposure time on the Lick 3 m telescope, has a signal-to-noise ratio of 80 per 0.025 A in the rest frame of the absorbers. We do not see any C IV lines down to a 2 sigma limit of W(1548) less than or equal to 1.4 mA, about one fifth of the strength of the lines seen by Lu. The C IV lines that Lu saw must be restricted to rare Ly-alpha systems with large H I column densities greater than or equal to 10(exp 14)/sq cm, which are too rare to show C IV in our sample. More common Ly-alpha systems with H I column densities of 10(exp 13)-10(exp 14)/sq cm do not show C IV lines. If their ionization is H/H I = 10(exp 4) then they have (C/H) less than or equal to -2.0.

Tytler, David↗
NASA NTRS1981

High-resolution laser absorption spectroscopy of ozone near 1129.4 cm (-1)

A Beer's Law experiment was performed with a tunable diode laser to determine self broadened line shape parameters of one infrared absorption ozone line in the nu1 band for ten pressures from 0.26 to 6.29 torr at 285 K. The SO2 line positions were used for wavelength calibration. Line shapes were iteratively fitted to the Voigt function at a Doppler width of 29.54 MHz (HWHM) resulting in values for the integrated line strength, (S), of (0.144 +/- 0.007) x 10 to the minus 20th/cm molecule/cu cm, line center frequency, nu sub o, of 1129.426/cm and the Lorentzian contributions to halfwidth. A linear least squares fit of (alpha sub L)5 as a function of pressure yielded a zero intercept of 15.27 +/- 0.29 MHz (rho = 0.99) and a broadening parameter, (alpha sub L)5, of 5.71 +/- 0.29 MHz/Torr. This results in a line width (FWHM) of 0.144 +/- .007/cm at 760 torr and 285 K.

Majorana, L. N.↗
NASA NTRS1974

Relation of solar wind fluctuations to differential flow between protons and alphas

An analysis is made of the difference between the alpha particle and proton flow velocities in the solar wind as observed by the OGO 5 satellite. The alpha and proton velocities from each of 962 spectral scans are compared with the variance of 32 solar wind flux measurements made during the scans. The average velocity difference is plotted for each of 10 logarithmic variance intervals and is seen to decrease and approach zero when the variance is high. It is shown that such an anticorrelation may be due to the fact the wave/particle interactions provide the drag force between two streams of different velocity in a collisionless plasma.

Neugebauer, M.↗
NASA NTRS1992

The ultraviolet absorption spectrum of the quasar H1821+643 (z = 0.297)

High resolution UV observations of the nearby luminous quasar H1821+643 are reported. A complete sample of 38 absorption lines has been constructed. There are five strong extragalactic Ly-alpha absorption lines in the spectrum, all with observed equivalent widths greater than 0.45 A. The local number density of Ly-alpha systems with rest equivalent widths larger than 0.32 A is estimated to be 13 +/- 5 Ly-alpha lines per unit redshift. Some of the Ly-alpha systems with redshifts significantly different from the quasar appear to be associated with galaxies or with clusters of galaxies. Two of the Ly-alpha lines have the same redshift within 400 km/s as that of an emission-line galaxy located at a projected separation from the quasar of about 90 kpc. One of the Ly-alpha systems in H1821+643 occurs at an a absorption redshift approximately equal to the emission-line redshift of the quasar and is accompanied by absorption from the C IV and of VI doublets; this is an example of associated absorption for large-redshift quasars.

Bahcall, John N.↗
NASA NTRS1978

The radii of Uranian rings alpha, beta, gamma, delta, epsilon, eta, 4, 5, and 6 from their occultations of SAO 158687

All available timing data for the occultations of SAO 158687 on March 10, 1977, by the cited rings of Uranus are analyzed. Least-squares fits to the data are performed using a model which postulates that rings alpha, beta, gamma, and delta are circular and coplanar. A solution obtained under the assumption that the ring plane coincides with the plane of the satellite orbits is adopted which yields radii of 44,844 km for ring alpha, 45,799 km for ring beta, 47,746 km for ring gamma, and 48,423 km for ring delta. The uncertainties in these values are discussed along with the apparent shapes and inclinations of these main rings. The mean radii estimated for the other rings are: 47,323 km for ring eta, 42,663 km for ring 4, 42,360 km for ring 5, and 41,980 km for ring 6.

Elliot, J. L.↗
DOE OSTI2020

Materials Data on Tc(CO)5 by Materials Project

Tc(CO)5 is Cubic alpha N2-like structured and crystallizes in the monoclinic C2/c space group. The structure is zero-dimensional and consists of eight Tc(CO)5 clusters. Tc3- is bonded in a square pyramidal geometry to five C+2.60+ atoms. There are a spread of Tc–C bond distances ranging from 1.94–2.01 Å. There are five inequivalent C+2.60+ sites. In the first C+2.60+ site, C+2.60+ is bonded in a linear geometry to one Tc3- and one O2- atom. The C–O bond length is 1.16 Å. In the second C+2.60+ site, C+2.60+ is bonded in a linear geometry to one Tc3- and one O2- atom. The C–O bond length is 1.16 Å. In the third C+2.60+ site, C+2.60+ is bonded in a linear geometry to one Tc3- and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C+2.60+ site, C+2.60+ is bonded in a linear geometry to one Tc3- and one O2- atom. The C–O bond length is 1.16 Å. In the fifth C+2.60+ site, C+2.60+ is bonded in a linear geometry to one Tc3- and one O2- atom. The C–O bond length is 1.16 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+2.60+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+2.60+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+2.60+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C+2.60+ atom. In the fifth O2- site, O2- is bonded in a single-bond geometry to one C+2.60+ atom.

36 MATERIALS SCIENCE↗
NASA NTRS1996

Estimation of the longitudinal and lateral-directional aerodynamic parameters from flight data for the NASA F/A-18 HARV

This progress report presents the results of an investigation focused on parameter identification for the NASA F/A-18 HARV. This aircraft was used in the high alpha research program at the NASA Dryden Flight Research Center. In this study the longitudinal and lateral-directional stability derivatives are estimated from flight data using the Maximum Likelihood method coupled with a Newton-Raphson minimization technique. The objective is to estimate an aerodynamic model describing the aircraft dynamics over a range of angle of attack from 5 deg to 60 deg. The mathematical model is built using the traditional static and dynamic derivative buildup. Flight data used in this analysis were from a variety of maneuvers. The longitudinal maneuvers included large amplitude multiple doublets, optimal inputs, frequency sweeps, and pilot pitch stick inputs. The lateral-directional maneuvers consisted of large amplitude multiple doublets, optimal inputs and pilot stick and rudder inputs. The parameter estimation code pEst, developed at NASA Dryden, was used in this investigation. Results of the estimation process from alpha = 5 deg to alpha = 60 deg are presented and discussed.

Napolitano, Marcello R.↗
DOE OSTI2017

Exploring lower-cost pathways to economical fusion power

This project, the Plasma Liner Experiment–ALPHA (PLX-α)5,is one of nine projects supported by the ALPHA Program6 of the Advanced Research Projects Agency–Energy (ARPA-E) of the U.S. Department of Energy (DOE). We use innovative, low-cost coaxial plasma guns (Fig. 1), developed and built by partner HyperV Technologies Corp.7, to launch a spherically converging array of supersonic plasma jets toward the middle of a large, spherical vacuum chamber (Fig. 2). A key near-term goal of PLX-α is to merge up to 60 plasma jets to form a spherically imploding plasma liner, as a low-cost, high-shot-rate driver for compressing magnetised target plasmas to fusion conditions. Our approach is known as plasma-jet-driven MIF (or PJMIF)8. A new startup company HyperJet Fusion Corporation (which recently received seed funding from Strong Atomics, LLC, a new fusion venture fund) aims to develop PJMIF under continued public and private sponsorship.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2023

Conceptual design of DIII-D experiments to diagnose the lifetime of spin polarized fuel

Abstract In magnetic fusion experiments, the cross sections for the D-T and D- 3 He fusion reactions are increased by as much as 50% if the fuel remains spin polarized parallel to the magnetic field. The goal of this study is to assess the feasibility of lifetime measurements of spin polarization, in magnetic fusion relevant conditions, on the DIII-D tokamak using relative changes in charged fusion product (CFP) loss measurements that depend upon the differential fusion cross section d σ /dΩ. Relative measurements that capture changes in the escaping CFP pitch, poloidal, and energy distributions are studied in two realistic TRANSP calculated plasma scenarios: (a) vector-polarized 3 He and D pellets are injected into a hot hydrogen plasma to produce thermonuclear reactions, and (b) a tensor-polarized deuterium pellet is injected into an L-mode hydrogen background plasma that includes unpolarized 3 He neutral beam injection. Ideal CFP signals in both scenarios show substantial pitch sensitivity to polarization for 14.7 MeV proton detection at a poloidal angle of − 56 ∘ (on the outer wall in the ion ∇ B direction), and strong sensitivity to polarization for 3.6 MeV alpha flux detection by an array of poloidal detectors. Energy-resolved measurements of 14.7 MeV protons are also sensitive to the degree of polarization for the − 56 ∘ port in the beam-plasma scenario. A realistic assessment of CFP signals in the thermonuclear scenario show count rates in the range of 2 × 10 4 cps for pitch-resolved proton detection and 2 × 10 5 cps for alpha flux measurements. Reduced chi-squared χ r 2 calculations show polarization lifetime measurements are feasible for either proton or alpha detection of both enhanced or suppressed polarization for the thermonuclear scenario. Measurements of gamma rays produced in the weak D + 3 He → γ + 5 Li branch complement the CFP measurements.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
NASA NTRS1996

Characterization of the early pulmonary inflammatory response associated with PTFE fume exposure

Heating of polytetrafluoroethylene (PTFE) has been described to release fumes containing ultrafine particles (approximately 18 nm diam). These fumes can be highly toxic in the respiratory tract inducing extensive pulmonary edema with hemorrhagic inflammation. Fischer-344 rats were exposed to PTFE fumes generated by temperatures ranging from 450 to 460 degrees C for 15 min at an exposure concentration of 5 x 10(5) particles/cm3, equivalent to approximately 50 micrograms/m3. Responses were examined 4 hr post-treatment when these rats demonstrated 60-85% neutrophils (PMNs) in their lung lavage. Increases in abundance for messages encoding the antioxidants manganese superoxide dismutase and metallothionein (MT) increased 15- and 40-fold, respectively. For messages encoding the pro- and anti-inflammatory cytokines: inducible nitric oxide synthase, interleukin 1 alpha, 1 beta, and 6 (IL-1 alpha, IL-1 beta, and IL-6), macrophage inflammatory protein-2, and tumor necrosis factor-alpha (TNF alpha) increases of 5-, 5-, 10-, 40-, 40-, and 15-fold were present. Vascular endothelial growth factor, which may play a role in the integrity of the endothelial barrier, was decreased to 20% of controls. In situ sections were hybridized with 33P cRNA probes encoding IL-6, MT, surfactant protein C, and TNF alpha. Increased mRNA abundance for MT and IL-6 was expressed around all airways and interstitial regions with MT and IL-6 demonstrating similar spatial distribution. Large numbers of activated PMNs expressed IL-6, MT, and TNF alpha. Additionally, pulmonary macrophages and epithelial cells were actively involved. These observations support the notion that PTFE fumes containing ultrafine particles initiate a severe inflammatory response at low inhaled particle mass concentrations, which is suggestive of an oxidative injury. Furthermore, PMNs may actively regulate the inflammatory process through cytokine and antioxidant expression.

Non-NASA Center↗
NASA NTRS1980

Low resolution infrared spectra of quasars

Recent observational results based on a joint infrared/optical survey of the hydrogen line spectra of a significant number of low and high redshift quasars are summarized. The spectra show that the Paschen-alpha and Balmer line ratios do not agree with the result of nominal case B recombination theory and vary widely within the quasars sampled. The range of P-alpha to H-beta ratios is a factor of roughly 6, while the range in Ly-alpha to H-alpha ratios is a factor of roughly 5. For the P-alpha:Balmer series, the deviations from case B recombination are not consistent with reddening, but appear, within large dispersions, to be consistent with optical depth effects in the Balmer lines affecting the lines ratios.

Soifer, B. T.↗