604
604
May 26, 2011
05/11
by
Liou, Jer-Chyi; Zook, Herbert A.; Jackson, A. A
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In this paper, we examine the effects of radiation pressure, Poynting-Robertson (PR) drag, and solar wind drag on dust grains trapped in mean motion resonances with the Sun and Jupiter in the restricted (negligible dust mass) three-body Problem. We especially examine the evolution of dust grains in the 1:1 resonance. As a first step, the Sun and Jupiter are idealized to both be in circular orbit about a common center of mass (circular restricted three-body problem). From the equation of motion...
Topics: NITRIC OXIDE, DISTRIBUTION FUNCTIONS, ELASTIC SCATTERING, ENERGY DISSIPATION, MOLECULAR GASES,...
225
225
Jun 11, 2011
06/11
by
Bar-Itzhack, Itzhack Y.; Harman, Richard R
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This paper presents the overall mathematical model and results from pseudo linear recursive estimators of attitude and rate for a spinning spacecraft. The measurements considered are vector measurements obtained by sun-sensors, fixed head star trackers, horizon sensors, and three axis magnetometers. Two filters are proposed for estimating the attitude as well as the angular rate vector. One filter, called the q-Filter, yields the attitude estimate as a quaternion estimate, and the other filter,...
Topics: ATMOSPHERIC CHEMISTRY, CYANIDES, HYDROGEN, HYDROCYANIC ACID, ATMOSPHERIC MODELS, BIOMASS BURNING,...
230
230
May 27, 2011
05/11
by
Blackaby, James R.; Lyman, E. Gene; Altermann, John A., II
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Inlet-performance and external-drag-coefficient characteristics are presented without analysis. Effects are shown of variations of fuselage boundary-layer diverter profile, bleed-surface porosity, bleed-exit area, and inlet ramp, and lip angle.
Topics: ARTIFICIAL SATELLITES, GAS DENSITY, MASS SPECTROMETERS, RADIO FREQUENCIES, SATELLITE ATMOSPHERES,...
The matrix-isolation technique has been employed to measure the mid-infrared spectra of several polycyclic aromatic nitrogen heterocycles in both neutral and cationic forms. The species studied include: 7,8 benzoquinoline (C13H9N); 2-azapyrene (C15H9N); 1- and 2-azabenz(a)anthracene (C17H11N); and 1-, 2-, and 4-azachrysene (also C17H11N). The experimentally measured band frequencies and intensities for each molecule are tabulated and compared with their theoretically calculated values computed...
Topics: NASA Technical Reports Server (NTRS), INFRARED SPECTROSCOPY, POLYCYCLIC AROMATIC HYDROCARBONS,...
We have investigated the energy distributions of the metastable oxygen atoms in the terrestrial thermosphere. Nascent O(lD) atoms play a fundamental role in the energy balance and chemistry of the terrestrial atmosphere, because they are produced by photo-chemical reactions in the excited electronic states and carry significant translational energies.
Topics: NASA Technical Reports Server (NTRS), METASTABLE ATOMS, ENERGY DISTRIBUTION, NITROGEN ATOMS, OXYGEN...
Impurity-helium solids are formed when a mixture of impurity and helium gases enters a volume of superfluid helium. Typical choices of impurity gas are hydrogen deuteride, deuterium, nitrogen, neon and argon, or a mixture of these. These solids consist of individual impurity atoms and molecules as well as clusters of impurity atoms and molecules covered with layers of solidified helium. The clusters have an imperfect crystalline structure and diameters ranging up to 90 angstroms, depending...
Topics: NASA Technical Reports Server (NTRS), PARAMAGNETISM, IMPURITIES, LIQUID HELIUM, SOLIDS, GAS...
The primary goal of this research project was to further extend the use of advanced heteroepitaxial-semiconductor crystal growth techniques such as molecular beam epitaxy (MBE) and to demonstrate significant gains in UV/blue photonic detection by designing and fabricating atomically-tailored heteroepitaxial GaAlN/GaInN photocathode device structures. This NASA Explorer technology research program has focused on the development of photocathodes for Cherenkov and scintillation radiation...
Topics: NASA Technical Reports Server (NTRS), CERENKOV RADIATION, CRYSTAL GROWTH, EPITAXY, MAGNETIC...
187
187
Jul 21, 2010
07/10
by
Peters, P. N
texts
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A solid state model is proposed which hopefully removes some of the objections to excited atoms being sources for light emanating from surfaces. Glow features are discussed in terms of excited oxygen atoms impinged on the surface, although other species could be treated similarly. Band formation, excited lifetime shortening and glow color are discussed in terms of this model. The model's inability to explain glow emanating above surfaces indicates a necessity for other mechanisms to satisfy...
Topics: LUMINOSITY, SPACE SHUTTLES, SPACEBORNE EXPERIMENTS, SURFACE TEMPERATURE, MASS SPECTROSCOPY,...
Spectroscopic measurements of non-equilibrium emission were made in the free stream of the 60 megawatts Interaction Heating Facility at NASA Ames Research Center. In the visible near infrared wavelength region, the most prominent emission was from molecular N2, and in the ultra violet region, the spectra were dominated by emission from molecular NO. The only atomic lines observed were those of copper (an erosion product of the electrodes). The bands of the 1st Positive system of N2 (if B is...
Topics: NASA Technical Reports Server (NTRS), EXCITATION, FREE FLOW, INTERACTIONAL AERODYNAMICS, EMISSION...
435
435
May 27, 2011
05/11
by
Tan, Benjami
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Using thermochromatic liquid crystal to measure surface temperature, an automated transient method with time-varying free-stream temperature is developed to determine local heat transfer coefficients. By allowing the free-stream temperature to vary with time, the need for complicated mechanical components to achieve a step temperature change is eliminated, and by using the thermochromatic liquid crystals as temperature indicators, the labor intensive task of installing many thermocouples is...
Topics: GROUND STATE, ATOMIC BEAMS, NITROGEN ATOMS, MOLECULES, ELEMENTARY PARTICLE INTERACTIONS, SCATTERING...
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342
May 31, 2011
05/11
by
Tao, Wei-Kuo; Starr, David OC.; Hou, Arthur; Newman, Paul; Sud, Yoges
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A workshop on cumulus parameterization took place at the NASA Goddard Space Flight Center from December 3-5, 2001. The major objectives of this workshop were (1) to review the problem of representation of moist processes in large-scale models (mesoscale models, Numerical Weather Prediction models and Atmospheric General Circulation Models), (2) to review the state-of-the-art in cumulus parameterization schemes, and (3) to discuss the need for future research and applications. There were a total...
Topics: CERENKOV RADIATION, MOLECULAR PUMPS, NITROGEN ATOMS, NITROGEN PLASMA, OPTOELECTRONIC DEVICES,...
894
894
May 23, 2011
05/11
by
Yuan, X. Q.; Wade, Charles E
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To determine the influence of brain trauma on blood acid-base and lactate-pyruvate responses to hemorrhage, and the effect of lactated Ringer's solution on these responses, 30 anesthetized rats were assigned to four groups: hemorrhage (n = 7), hemorrhage following fluid percussion brain trauma (trauma-hemorrhage group) (n = 7), hemorrhage treated with lactated Ringer's solution (hemorrhage-resuscitation group) (n = 8), and hemorrhage following brain trauma treated with lactated Ringer's...
Topics: OXYGEN ATOMS, VIBRATIONAL SPECTRA, EMISSION SPECTRA, WIND TUNNELS, PLASMA HEATING, ABEL FUNCTION,...
245
245
May 6, 2010
05/10
by
Mc Gee, H. A., Jr
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Chemical reactivity of hydrogen, nitrogen, and oxygen at cryogenic temperatures, and krypton fluoride studies
Topics: CHEMICAL REACTIONS, OXYGEN ATOMS, REACTIVITY, CRYOGENIC TEMPERATURE, FLUORINE COMPOUND, HYDROGEN,...
The neutral atmospheric composition spectrometer on board the Dynamics Explorer 2 spacecraft sampled several major and minor thermospheric gases including atomic nitrogen. A selection of passes over the polar cusp that provide a quantitative measure of N densities in this region and provide evidence of localized density increases due to soft particle precipitation is presented. Increases in N densities are frequently observed but are smaller than accompanying increases in N2 densities. The...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC COMPOSITION, DENSITY DISTRIBUTION, NEUTRAL...
By leveraging a new uncertainty markup technique, two risk analysis methods are used to compute the uncertainty of lunar-return shock layer radiation predicted by the High temperature Aerothermodynamic Radiation Algorithm (HARA). The effects of epistemic uncertainty, or uncertainty due to a lack of knowledge, is considered for the following modeling parameters: atomic line oscillator strengths, atomic line Stark broadening widths, atomic photoionization cross sections, negative ion...
Topics: NASA Technical Reports Server (NTRS), AEROTHERMODYNAMICS, ALGORITHMS, RADIANCE, SHOCK LAYERS,...
A NASA grant provided support for a research project at Augsbury College, Minneapolis, Minnesota for the analysis of atomic nitrogen density data obtained by the Neutral Atmospheric Composition Spectrometer (NACS) on board the Dynamics Explorer-2 satellite. Initial funding was for an exploratory study of the feasibility of obtaining ambient densities of N from source densities of NO. Funding was continued under the Dynamics Explorer Guest Investigator Program when initial studies indicated...
Topics: NASA Technical Reports Server (NTRS), AMBIENCE, COMPOSITION (PROPERTY), DENSITY DISTRIBUTION,...
226
226
Jun 18, 2010
06/10
by
Donahue, T. M
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Ionospheric reaction rates for oxygen nitrogen ion-atom interchange
Topics: ION ATOM INTERACTIONS, IONOSPHERE, NITROGEN ATOM, OXYGEN ATOM, REACTION TIME, IONOSPHERES,...
No abstract available
Topics: NASA Technical Reports Server (NTRS), ICE, LIGHTNING, CATALYTIC ACTIVITY, CRYSTALS, NITROGEN...
In an attempt to understand the process of electrical conduction in polyacrylonitrile (PAN)-based carbon fibers, calculations were carried out on cluster models of the fiber consisting of carbon, nitrogen, and hydrogen atoms using the modified intermediate neglect of differential overlap (MINDO) molecular orbital (MO) method. The models were developed based on the assumption that PAN carbon fibers obtained with heat treatment temperatures (HTT) below 1000 C retain nitrogen in a graphite-like...
Topics: NASA Technical Reports Server (NTRS), CARBON FIBERS, ELECTRICAL RESISTIVITY, FIBER COMPOSITES,...
363
363
Jun 20, 2010
06/10
by
Mc Gee, H. A., Jr
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eye 363
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No Abstract Available
Topics: CHEMICAL REACTIONS, HYDROGEN, NITROGEN ATOMS, OXYGEN ATOMS, REACTIVITY
Spectral radiation measurements were made in the range of 200 to 900 nm across a section of the plenum of an arc jet wind tunnel using a series of optical fibers. The spectra contained line radiation from Oxygen and Nitrogen atoms and molecular radiation from N2(+), N2, and NO. Abel inversion technique is used to obtain radial distribution of the spectra. The analysis yielded radial profiles of the electronic excitation, vibrational and rotational temperatures of the flow field. Spectral...
Topics: NASA Technical Reports Server (NTRS), OXYGEN ATOMS, NITROGEN ATOMS, RADIAL DISTRIBUTION,...
This report summarizes our investigations performed under NASA Grant NAG5-8058. The three-year research supported by the Geospace Sciences SR&T program (Ionospheric, Thermospheric, and Mesospheric Physics) has been designed to investigate fluxes of energetic oxygen and nitrogen atoms in the terrestrial thermosphere. Fast atoms are produced due to absorption of the solar radiation and due to coupling between the ionosphere and the neutral thermospheric gas. We have investigated the impact of...
Topics: NASA Technical Reports Server (NTRS), HOT ATOMS, KINETICS, THERMOSPHERE, OXYGEN ATOMS, NITROGEN...
Measurements were made of the radiating gas cap of a blunt body in a NASA-Ames 20 MW arc-jet wind tunnel. The test gas was air. Spectra of the flux incident on a small aperture centered at the stagnation region were obtained. A helium-cooled, magnesium fluoride window transmitted the flux into an evacuated collimating system that focused the aperture onto the entrance slit of a spectrometer. Data were obtained with films and by photomultipliers. The spectral ranges covered were the vacuum...
Topics: NASA Technical Reports Server (NTRS), AERODYNAMICS, FAR ULTRAVIOLET RADIATION, LINE SPECTRA, NEAR...
Hydrogen cyanide is not usually considered in atmospheric chemical models. The paper presents three reasons why hydrogen cyanide is likely to be significant for atmospheric chemistry. Firstly, HCN is a product and marker of biomass burning. Secondly, it is also likely that lightning is producing HCN, and as HCN is sparingly soluble it could be a useful long-lived "smoking gun" marker of lightning activity. Thirdly, the chemical decomposition of HCN leads to the production of small...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC CHEMISTRY, CYANIDES, HYDROGEN, HYDROCYANIC ACID,...
287
287
Jun 1, 2010
06/10
by
Danilov, A. D
texts
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Atomic nitrogen dissociation in upper atmosphere
Topics: GAS DENSITY, NITROGEN, UPPER ATMOSPHERE, GAS DISSOCIATION, HIGH ALTITUDE, MONATOMIC GASES,...
The catalytic efficiency (atom recombination coefficients) for advanced ceramic thermal protection systems was calculated using arc-jet data. Coefficients for both oxygen and nitrogen atom recombination on the surfaces of these systems were obtained to temperatures of 1650 K. Optical and chemical stability of the candidate systems to the high energy hypersonic flow was also demonstrated during these tests.
Topics: NASA Technical Reports Server (NTRS), THERMAL PROTECTION, RECOMBINATION COEFFICIENT, OXYGEN ATOMS,...
A method of measuring two key parameters of H3 color centers in diamond has been created as part of a continuing effort to develop tunable, continuous-wave, visible lasers that would utilize diamond as the lasing medium. (An H3 color center in a diamond crystal lattice comprises two nitrogen atoms substituted for two carbon atoms bonded to a third carbon atom. H3 color centers can be induced artificially; they also occur naturally. If present in sufficient density, they impart a yellow hue.)...
Topics: NASA Technical Reports Server (NTRS), CONTINUOUS WAVE LASERS, ABSORPTION SPECTROSCOPY, DIAMONDS,...
A database for efficiently computing the electron Stark broadening line widths for atomic N, O, and C lines is constructed. The line width is expressed in terms of the electron number density and electronatom scattering cross sections based on the Baranger impact theory. The state-to-state cross sections are computed using the semiclassical approximation, in which the atom is treated quantum mechanically whereas the motion of the free electron follows a classical trajectory. These...
Topics: NASA Technical Reports Server (NTRS), DATA BASES, SPECTRAL LINE WIDTH, NITROGEN ATOMS, OXYGEN...
Recent work suggested that NO2 may be responsible for the observed continuum glow near surfaces of the space shuttle. The observations of atomic nitrogen (N) are reported at shuttle altitudes using mass spectrometers, giving special attention to the surface reactions of N relevant to the production of NO2 on spacecraft surfaces. Data from two semi-open sources mass spectrometers, the OSS instruments on the Atmosphere Explorer-C and -D satellites, and the closed source Neutral Atmospheric...
Topics: NASA Technical Reports Server (NTRS), LUMINOSITY, MASS SPECTROSCOPY, NITROGEN ATOMS, NITROGEN...
Accurate collision integrals are reported for the interactions of N(4 S 0) + N(4 S 0), O(3 P), and N(4 S 0) + O(3 P). These are computed from a semiclassical formulation of the scattering using the best available representations of all of the potential energy curves needed to describe the collisions. Experimental RKR curves and other accurate measured data are used where available; the results of accurate ab initio electronic structure calculations are used to determine the remaining potential...
Topics: NASA Technical Reports Server (NTRS), ATOMIC COLLISIONS, COLLISION PARAMETERS, GAS MIXTURES, HIGH...
We investigated the contribution of energetic nitrogen atoms to the production of nitric oxide in the thermosphere and their influence on the infrared emission spectrum. The nitric oxide molecules are important contributors to the cooling of the atmosphere. We first pointed out that in determining the energy distribution of the nitrogen atoms, it is important to take into account the thermal motion of the atmospheric gases. It had been ignored in all earlier studies. The source spectra are...
Topics: NASA Technical Reports Server (NTRS), NITRIC OXIDE, NITROGEN ATOMS, THERMOSPHERE, INFRARED SPECTRA,...
Major emphasis of the investigation was the development of theoretical and numerical models of the aurora and of high latitude ionospheric processes. In particular: (1) the NCAR TIGCM (Thermosphere-Ionosphere Global Circulation Model) was updated to include mid and low latitude electrodynamics (this version is called TIE-GCM); (2) the NCAR TIE-GCM was modified to include a more realistic representation of the aurora; (3) the UAF auroral electron transport model was modified to include local...
Topics: NASA Technical Reports Server (NTRS), NUMERICAL ANALYSIS, MATHEMATICAL MODELS, AURORAS, LATITUDE,...
One mechanism by which NO(x) is produced in the atmosphere is heating in lightning discharge channels. Since most viable proposed electrification mechanisms involve ice crystals, it is reasonable to assume that lightning discharge channels frequently pass through fields of ice particles of various kinds. We address the question of whether ice crystals may serve as catalysts for the production of NO(x) by lightning discharges. If so, and if the effect is large, it would need to be taken into...
Topics: NASA Technical Reports Server (NTRS), NITROGEN OXIDES, LIGHTNING, ICE, ELECTRIFICATION, CATALYSTS,...
The reactivity of some N-acyl and N-sulfonyl-hydrazines 2-4, 10a-10g, 12, 13, 16a, 16b and of hydrazones 18, benzyldihydrazone 21 towards pyrylium salts 1 was examined. By reaction of 2,4,6-trimethyl-pyrylium salt 1 with substituted hydrazines some pyridinium salts were obtained. Relationships between basicity and reactivity were discussed.
Topics: NASA Technical Reports Server (NTRS), CHEMICAL REACTIONS, NITROGEN ATOMS, ORGANIC COMPOUNDS,...
Measurements of the neutral thermosphere were conducted in northern Scandinavia during the Energy Budget Campaign. These measurements included determinations of N2, O, and Ar densities using rocket-borne experiments. The results obtained in the experiments are presented, taking into account also details regarding the employed experimental methods, and an evaluation of the significance of the data. It is found that there are striking differences in thermospheric distributions of the neutral...
Topics: NASA Technical Reports Server (NTRS), ARGON, ATMOSPHERIC COMPOSITION, NITROGEN ATOMS, OXYGEN ATOMS,...
The 25 amino acids long, transmembrane fragment of the Influenza virus M2 protein forms a homotetrameric channel that transports protons across lipid bilayers. It has been postulated that high efficiency and selectivity of this process is due to gating by four histidine residues that occlude the channel lumen in the closed state. Two mechanisms of gating have been postulated. In one mechanism, the proton is "shuttled" through the gate by attaching to the delta nitrogen atom on the...
Topics: NASA Technical Reports Server (NTRS), HISTIDINE, LIPIDS, PROTEINS, INFLUENZA, VIRUSES, PROTONS,...
The goal of this research grant was to calculate accurate oscillator strengths and electron collisional excitation strengths for inelastic transitions in atomic species of relevance to Planetary Atmospheres. Large scale configuration-interaction atomic structure calculations have been performed to obtain oscillator strengths and transition probabilities for transitions among the fine-structure levels and R-matrix method has been used in the calculations of electron-ion collision cross sections...
Topics: NASA Technical Reports Server (NTRS), SCATTERING CROSS SECTIONS, ELECTRON IMPACT, EXCITATION, IONS,...
This report summarizes our research performed under NASA Grant NAG5-11857. The three-year grant have been supported by the Geospace Sciences SR&T program. We have investigated the energetic metastable oxygen and nitrogen atoms in the terrestrial stratosphere, mesosphere and thermosphere. Hot atoms in the atmosphere are produced by solar radiation, the solar wind and various ionic reactions. Nascent hot atoms arise in ground and excited electronic states, and their translational energies are...
Topics: NASA Technical Reports Server (NTRS), METASTABLE ATOMS, OXYGEN ATOMS, ATMOSPHERIC CHEMISTRY,...
722
722
Jul 6, 2010
07/10
by
Rogers, J. G
texts
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The major conclusion of the detailed examination of the human factors engineering design standard is that it is unsuitable for future spacecraft design. The standard, published in 1966, was not intended to be a zero or reduced gravity standard and was directed primarily toward ground support equipment and technology. Futhermore, ambiguities, conflicts, and unenforceable requirements contribute to the difficulty. The role of man in future space missions and its impact on human engineering...
Topics: METEOROIDS, RADIANT FLUX DENSITY, SPECTROGRAMS, COSMIC GASES, METEOR TRAILS, NITROGEN ATOMS,...
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323
May 31, 2011
05/11
by
Breon, S. R.; Shirey, K. A.; Banks, I. S.; Warner, B. A.; Boyle, R. F.; Mustafi, S
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The Alpha Magnetic Spectrometer-02 (AMS-02) is an experiment that will be flown as an attached payload on the International Space Station to detect dark matter and antimatter. It uses large superconducting magnets cooled with superfluid helium to bend the path of cosmic particles through a series of detectors, which then measure the mass, speed, charge, and direction of the particles. Four Sunpower M87N Stirling-cycle cryocoolers are used to extend the mission life by cooling the outer...
Topics: INFRARED SPECTROSCOPY, POLYCYCLIC AROMATIC HYDROCARBONS, INFRARED RADIATION, DIPOLE MOMENTS,...
