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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 1,621 records · Page 90
All sourcesNASA NTRSDOE OSTI
NASA NTRS1977

Total Born approximation cross sections for single electron loss by atoms and ions colliding with atoms

The first born approximation (FBA) is applied to the calculation of single electron loss cross sections for various ions and atoms containing from one to seven electrons. Screened hydrogenic wave functions were used for the states of the electron ejected from the projectile, and Hartree-Fock elastic and incoherent scattering factors were used to describe the target. The effect of the target atom on the scaling of projectile ionization cross sections with respect to the projectile nuclear charge was explored in the case of hydrogen-like ions. Scaling of the cross section with respect to the target nuclear charge for electron loss by Fe (+25) in collision with neutral atoms ranging from H to Fe is also examined. These results were compared to those of the binary encounter approximation and to the FBA for the case of ionization by completely stripped target ions.

Rule, D. W.↗
NASA NTRS1977

Emissions and Total Energy Consumption of a Multicylinder Piston Engine Running on Gasoline and a Hydrogen-gasoline Mixture

A multicylinder reciprocating engine was used to extend the efficient lean operating range of gasoline by adding hydrogen. Both bottled hydrogen and hydrogen produced by a research methanol steam reformer were used. These results were compared with results for all gasoline. A high-compression-ratio, displacement production engine was used. Apparent flame speed was used to describe the differences in emissions and performance. Therefore, engine emissions and performance, including apparent flame speed and energy lost to the cooling system and the exhaust gas, were measured over a range of equivalence ratios for each fuel. All emission levels decreased at the leaner conditions. Adding hydrogen significantly increased flame speed over all equivalence ratios.

Cassidy, J. F.↗
NASA NTRS1976

Investigation of the effect of atmospheric dust on the determination of total ozone from the earth's ultraviolet reflectivity measurements, 1

Two computer algorithms are described. These algorithms were used for computing the aximuth-independent component of the intensity of the monochromatic radiation emerging at the top of a pseudo-spherical atmosphere with arbitrary vertical distribution of ozone, and with any arbitrary height distribution of up to two different kinds of aerosol. This atmospheric model was assumed to rest on a surface obeying Lambert's law of reflection.

Dave, J. V.↗
NASA NTRS1977

Introduction: Man and his total environment

Environmental changes and the utilization of finite resources are analyzed. Beyond the satisfaction of basic physical needs, the advancement of civilization toward an ever-improving quality of like is likewise dependent upon mans' interaction with his entire environment. This larger system is controlled externally by electromagnetic and particle energy from the sun and internally by the dynamic interchange of energy between the solid earth, oceans, the atmosphere, and the magnetosphere. This exchange of energy that determines the structure of the earth's environemental system is evaluated.

Source record↗
NASA NTRS1976

Irradiate-anneal screening of total dose effects in semiconductor devices

Judicious choice of radiation dose and parameter change acceptance criteria, absence of anomalous anneal phenomena, and absence of anomalous reirradiation effects are recognized as essential for a successful irradiation-anneal (IRAN) screening procedure to ensure that no device will fall, upon reirradiation, above parametric limits assigned for the worst case application. Reirradiation and irradiation-anneal behavior of various semiconductor devices are compared and those that do not lend themselves to IRAN screening are singled out. Information needed to judge the suitability of an IRAN type screening program is detailed. Reasons for success of the limited IRAN screening of flight parts for the Mariner Jupiter/Saturn (MJS '77) spacecraft are indicated.

Stanley, A. G.↗
NASA NTRS1977

Total Born-approximation cross sections for single-electron loss by atoms and ions colliding with atoms

The first Born approximation (FBA) is applied to the calculation of single-electron-loss cross sections for various ions and atoms containing from one to seven electrons. Screened hydrogenic wave functions are used for the states of the electron ejected from the projectile, and Hartree-Fock elastic and incoherent scattering factors are used to describe the target. The effect of the target atom on the scaling of projectile ionization cross sections with respect to the projectile nuclear charge is explored in the case of hydrogenlike ions. Also examined is the scaling of the cross section with respect to the target nuclear charge for electron loss by Fe(25+) in collision with neutral atoms ranging from H to Fe. These results are compared with those of the binary-encounter approximation (BEA) and with the FBA for the case of ionization by completely stripped target ions. Electron-loss cross sections are also calculated for the ions O(i+) (i = 3-7) and N(i+) (i = 0-6) in collision with He targets in the energy range of approximately 0.1 to 100 MeV/nucleon. These results are found to be in excellent agreement with the available data near the peak of the ionization cross section.

Rule, D. W.↗
NASA NTRS1978

Total system issues

A raw computer resource capable of one billion floating point operations per second will have multiple parallel and/or segmented functional units to obtain such a speed. The system programmers, software writers and users are faced with the task of writing operating systems, compilers and application programs to utilize such a capability efficiently. The software problem of giving the user access to the available power of the machine is discussed.

Levesque, J. M.↗
NASA NTRS1977

Silicon solar cells with a total power capacity of 30 kilowatts

The bulk of the contract effort was carried out in the following two phases: Phase 1 -- module design, Pre-production module fabrication, inspection and test. Phase 2 -- Production, test and delivery. Effort during the first two months of the contract concentrated on design of a solar module to meet specification. Basic module design resulting from this effort is as follows: (1) frame design; (2) cell pan design; (3) cell interconnection; (4) encapsulation; (5) electrical performance.

Source record↗
NASA NTRS1978

Estimating maximum instantaneous distortion from inlet total pressure rms measurements

In the present paper, a new mathematical model of inlet turbulence is developed by application of basic fluid dynamics and statistical concepts. The model provides an understanding of the turbulent inlet flow as well as a means of describing the flow in quantitative terms. Specifically, the maximum instantaneous distortion produced by inlet unsteady flow can be estimated by the simple measurement of rms data. Practical application of these techniques leads to a data/acquisition/reduction system that is at least one, and maybe two, orders of magnitude less expensive than conventional methods. Each data point can be reduced in terms of the mean strength of the turbulent vortices. By storing these two parameters (that are representative of the unsteady flow with the steady state information), the maximal instantaneous distortion can be reconstructed for other distortion factors at any time subsequent to the test.

Melick, H. C., Jr.↗