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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 253 records · Page 14
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Satellite auxiliary-propulsion selection techniques. Applications of selection techniques to the ATS-H satellite

The analysis required to estimate auxiliary-propulsion system requirements for a mission which includes tipoff rate reduction, acquisitions, disturbance torques, orbital disturbances, and spacecraft commanded maneuvers is presented. The comparison of several candidate auxiliary-propulsion systems and system combinations for an advanced applications technology satellite (ATS-H) is described. A generalized auxiliary-propulsion system tradeoff, based on mission cost effectiveness criteria, is examined. The specific mission assumptions for the ATS-H spacecraft are included, along with a discussion of the sensitivity of the final selection to these assumptions.

Holcomb, L. B.↗
NASA NTRS1991

Emission-line and continuum properties of 92 bright QSOs - Luminosity dependence and differences between radio-selected and optically selected samples

The emission line and continuum properties of new spectra of 92 QSOs are investigated. A detailed deconvolution of the semiforbidden C III 1909 A blend reveals that the secondary feature is almost certainly Al III 1859 A. A study of the Mg II 2800 A emission-line profiles suggests that the broad 'shoulders' often observed are probably intrinsic to the Mg II emission line. It is shown that the QSOs discovered by slitless spectroscopic methods do not differ significantly from those discovered by UV excess surveys. Significant correlations with luminosity are found for W(Mg II), W(semiforbidden C III), I(C III)/I(Mg II), and the continuum ratio fv(1909 A)/fv(2800 A). All of the significant correlations are substantially stronger for a radio-selected subsample compared to a radio-quiet subsample. The C IV and semiforbidden C III emission lines each have a mean blueshift relative to Mg II of 450 km/s while semiforbidden C IV has a mean blueshift relative to semiforbidden C III of 200 km/s.

Steidel, Charles C.↗
NASA NTRS2000

Training Select-in Interviewers for Astronaut Selection: A Program Evaluation

Psychological factors critical to the success of short and long-duration missions have been identified in previous research; however, evaluation for such critical factors in astronaut applicants leaves much room for human interpretation. Thus, an evaluator training session was designed to standardize the interpretation of critical factors, as well as the structure of the select-in interview across evaluators. The purpose of this evaluative study was to determine the effectiveness of the evaluator training sessions and their potential impact on evaluator ratings.

Hysong, S.↗
NASA NTRS2003

Assessing blood brain barrier dynamics or identifying or measuring selected substances or toxins in a subject by analyzing Raman spectrum signals of selected regions in the eye

A non-invasive method for analyzing the blood-brain barrier includes obtaining a Raman spectrum of a selected portion of the eye and monitoring the Raman spectrum to ascertain a change to the dynamics of the blood brain barrier. Also, non-invasive methods for determining the brain or blood level of an analyte of interest, such as glucose, drugs, alcohol, poisons, and the like, comprises: generating an excitation laser beam (e.g., at a wavelength of 600 to 900 nanometers); focusing the excitation laser beam into the anterior chamber of an eye of the subject so that aqueous humor, vitreous humor, or one or more conjunctiva vessels in the eye is illuminated; detecting (preferably confocally detecting) a Raman spectrum from the illuminated portion of the eye; and then determining the blood level or brain level (intracranial or cerebral spinal fluid level) of an analyte of interest for the subject from the Raman spectrum. In certain embodiments, the detecting step may be followed by the step of subtracting a confounding fluorescence spectrum from the Raman spectrum to produce a difference spectrum; and determining the blood level and/or brain level of the analyte of interest for the subject from that difference spectrum, preferably using linear or nonlinear multivariate analysis such as partial least squares analysis. Apparatus for carrying out the foregoing methods are also disclosed.

Lambert, James L.↗
DOE OSTI2016

Super-surface selective nanomembranes providing simultaneous high permeation flux and high selectivity

Superhydrophobic membrane structures having a beneficial combination of throughput and a selectivity. The membrane structure can include a porous support substrate; and a membrane layer adherently disposed on and in contact with the porous support substrate. The membrane layer can include a nanoporous material having a superhydrophobic surface. The superhydrophobic surface can include a textured surface, and a modifying material disposed on the textured surface. Methods of making and using the membrane structures.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Super-surface selective nanomembranes providing simultaneous high permeation flux and high selectivity

Superhydrophobic membrane structures having a beneficial combination of throughput and a selectivity. The membrane structure can include a porous support substrate; and a membrane layer adherently disposed on and in contact with the porous support substrate. The membrane layer can include a nanoporous material having a superhydrophobic surface. The superhydrophobic surface can include a textured surface, and a modifying material disposed on the textured surface. Methods of making and using the membrane structures.

42 ENGINEERING↗
DOE OSTI2018

Pt/Ferric Hydroxyphosphate: An Effective Catalyst for the Selective Hydrogenation of α,β-Unsaturated Aldehydes (Ketones) into α,β-Unsaturated Alcohols

Four micro (nano)-sized mesoporous ferric hydroxyphosphates (FHP) are synthesized by a reverse microemulsion-solvothermal method, and then are used as supports to prepare supported Pt catalysts. The mean particle diameter of Pt nanoparticles (NPs) was 4.5–4.6 nm. When the four different Pt/FHP catalysts were used into the hydrogenation of α,β-unsaturated aldehydes (ketones) to their corresponding unsaturated alcohols, Pt/FHP (c) catalyst showed better catalytic performance than the other three partners. Under the optimal experimental conditions, several tested α,β-unsaturated aldehydes could be effectively transformed into corresponding unsaturated alcohols over Pt/FHP (c) catalyst. The catalyst could be recycled and reused several times without activity loss. We propose the stronger interaction between the Pt NPs and ferric ions of the FHP (c) are responsible for its good catalytic performance, and this stronger interaction should be rooted in its enhanced Lewis acid strength.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Photolysis of Tp'Rh(CNneopentyl)(PhNCNneopentyl) in the presence of ketones and esters: kinetic and thermodynamic selectivity for activation of different aliphatic C–H bonds

The competitive fragment [Tp'Rh(CNneopentyl)], generated from the precursor Tp'Rh(CNneopentyl)(PhN CNneopentyl), underwent oxidative addition of substituted ketones and esters resulting in Tp'Rh(CNneopentyl)(R)(H) complexes (Tp' = tris-(3,5-dimethylpyrazolyl)borate). These C–H activated complexes underwent reductive elimination at varying temperatures (24–70 °C) in C 6 D 6 or C 6 D 12 . Using previously established kinetic techniques, the relative Rh–C bond strengths were calculated. Analysis of the relative Rh–C bond strengths vs. C–H bond strengths demonstrates a linear correlation with slope R M–C/C–H = 1.22 (12). In general, α-substituents increase the relative Rh–C bond strengths compared to the C–H bond that is broken.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2016

Mass selective separation applied to radioisotopes of cesium: Mass selective applied to radioisotopes

A developed technique that uses the intrinsic mass-based separation capability of a quadrupole mass spectrometer has been used to resolve spectral radiometric interference of two isotopes of the same element. In this work the starting sample was a combination of 137Cs and 134Cs and was (activity) dominated by 137Cs and this methodology separated and “implanted” 134Cs that was later quantified for spectral features and ac- tivity with traditional radiometric techniques. This work demonstrated a 134Cs/137Cs activity ratio enhancement of >4 orders of magnitude and complete removal of 137Cs spectral features from the implanted target mass (i.e., 134).

Cesium↗