Search NASA⌕ Search

SEARCH · Search NASA

Results for “FORTIS”

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 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Lunar polymict breccia 14321 - A compositional study of its principal components

Forty-nine sub-samples of the polymict breccia 14321,184 have been excavated from the rock and analyzed by instrumental activation analysis techniques, specially modified to allow examination of small samples. Two distinct types of microbreccia clasts were analysed. A mare-type basalt of unusual composition is present as several discrete clasts. Mixing models for the clastic components of the breccia illustrate that at least three stages of assembly may be distinguished on compositional grounds. The first was at a site such that KREEP-rich materials dominated the clastic rocks formed, although a variety of lithic fragments were apparently present. The second assembly stage may have been primarily that of comminution and mixing of the more primitive materials, with addition of mare-type basalt clasts. The third stage saw addition of clasts of 14321-type basalt. In the final assembly stage, the light matrix was apparently formed entirely by mutual abrasion of the pre-existing clasts, resulting in little or no change in bulk composition.

Duncan, A. R.↗
NASA NTRS1975

Joint USAF/NASA hypersonic research aircraft study

A joint USAF/NASA study has developed a conceptual design for a new high-speed research airplane (X-24C) and identified candidate flight research experiments in the Mach 3 to 6 speed range. Four major categories of high priority research experiments are described as well as the X-24C design concept. The vehicle, a rocket-boosted, delta planform aircraft, is air launched from a B-52 and is capable of forty seconds of rocket cruise at Mach 6 with a research scramjet. Research provisions include a dedicated 10-foot long research experiments section, removable fins and strakes, and provisions for testing integrated airbreathing propulsion systems.

F. S. Kirkham↗
NASA NTRS1975

Estimate of contribution of jet aircraft operations to trace element concentration at or near airports

Samples of ASTM type A jet fuel were analyzed for trace element content by instrumental neutron activation techniques. Forty-nine elements were sought. Only ten, aluminum, gold, indium, lanthanum, titanium, vanadium, barium, dysprosium, tellurium, and uranium, were observed at levels above the detection limits encountered; of these only aluminum, titanium, and barium were present at concentrations greater than 0.1 ppm. Estimates of exhaust gas concentrations are made, and the ambient contribution at or near airports is calculated by using the Los Angeles International Airport dispersion model. It is shown that the ambient contribution is about an order of magnitude below typical urban levels for virtually all elements sought.

Fordyce, J. S.↗
NASA NTRS1975

The detection of tightly closed flaws by nondestructive testing (NDT) methods

Liquid penetrant, ultrasonic, eddy current and X-radiographic techniques were optimized and applied to the evaluation of 2219-T87 aluminum alloy test specimens in integrally stiffened panel, and weld panel configurations. Fatigue cracks in integrally stiffened panels, lack-of-fusion in weld panels, and fatigue cracks in weld panels were the flaw types used for evaluation. A 2319 aluminum alloy weld filler rod was used for all welding to produce the test specimens. Forty seven integrally stiffened panels containing a total of 146 fatigue cracks, ninety three lack-of-penetration (LOP) specimens containing a total of 239 LOP flaws, and one-hundred seventeen welded specimens containing a total of 293 fatigue cracks were evaluated. Nondestructive test detection reliability enhancement was evaluated during separate inspection sequences in the specimens in the 'as-machined or as-welded', post etched and post proof loaded conditions. Results of the nondestructive test evaluations were compared to the actual flaw size obtained by measurement of the fracture specimens after completing all inspection sequences. Inspection data were then analyzed to provide a statistical basis for determining the flaw detection reliability.

Rummel, W. D.↗
NASA NTRS1975

Airship construction

Forty-four years ago the first successful metal airship was completed and delivered to the United States Navy, the ZMC-2. Between those years and the present, very little effort or serious consideration has been given to the manufacture, design, construction, or economic impact of airships. It is important to retain and exploit the small but continually diminishing pool of airship talent that will expedite the success of the United States in what is now a pioneering venture. The relative simplicity of airship construction, utilizing the tremendous technical advances of the last 44 years, leads to the conclusion that this form of transportation holds great promise for reducing costs of military missions and improving the international competitive position of the United States in commercial applications.

Roda, J.↗
NASA NTRS1975

Electronic delay ignition module for single bridgewire Apollo standard initiator

An engineering model and a qualification model of the EDIM were constructed and tested to Scout flight qualification criteria. The qualification model incorporated design improvements resulting from the engineering model tests. Compatibility with single bridgewire Apollo standard initiator (SBASI) was proven by test firing forty-five (45) SBASI's with worst case voltage and temperature conditions. The EDIM was successfully qualified for Scout flight application with no failures during testing of the qualification unit. Included is a method of implementing the EDIM into Scout vehicle hardware and the ground support equipment necessary to check out the system.

Ward, R. D.↗
NASA NTRS1976

Experimental study of transient liquid motion in orbiting spacecraft

A test program was conducted involving forty-five drops of liquid propellant in instrumented tanks. Biaxial, low-g accelerations were applied to the model propellant tanks during free-fall testing, and forces exerted during liquid reorientation were measured and recorded. High speed photographic records of the liquid reorientation were also made. The test data was used to verify a mechanical analog which portrays the liquid as a point mass moving on an ellipsoidal constraint surface. The mechanical analog was coded into two FORTRAN 4 digital computer programs. Results showed excellent correlation between test data and analytical predictions of reorientation forces and liquid center of mass motion, verifying the basic analytical approach.

Berry, R. L.↗
NASA NTRS1974

Changes in the performance characteristics of a GaAs near infrared light emitting diode when exposed to various current and thermal stresses

The changes that occurred in the optical and electrical characteristics of a near infrared, GaAs light emitting diode, when operated under various levels and combinations of current and thermal stresses are discussed. A total of forty parts were operated for two thousand hours under eight different sets of dc current and ambient temperature conditions. Degradation in the radiant optical power of these devices was thirty-four percent when operated at their rated current and an ambient temperature of 298K (25 C). Derating the current and/or the thermal stress reduced the degradation of this parameter in approximately a linear manner. All degraded devices behaved similarly, exhibiting rapid nonlinear degradation followed by a gradual linear degradation and finally a period of stable operation. An attempt was made to correlate initial device condition to degradation during stress testing, but met with little success.

Thomas, E. F., Jr.↗
NASA NTRS1975

Program to study optimal protocol for cardiovascular and muscular efficiency

Two possible ways to minimize the effects of deconditioning in space are; To achieve a very high level of conditioning immediately prior to flight, and to provide a regimen in the capsule which will maintain a moderate degree of fitness. It was determined that running and riding a bicycle ergometer at comparable heart rates produced similar gains in physical fitness variables. It was found that subjects who exercised at a 180 heart rate made greater gains in physical fitness than did those exercising at a 140 or 160 heart rate. When the length of the workout was varied, subjects exercising sixty minutes per day made greater gains than those exercising twenty or forty minutes per day. Subjects who discontinued training slowly deconditioned, but a moderate level of fitness could be maintained by exercising at a pulse rate of 160 beats per minute for twenty minute periods three times a week. Subjects who overtrained twice daily to near exhaustion increased in fitness.

Olree, H. D.↗
NASA NTRS1976

Advanced Composites: Mechanical Properties and Hardware Programs for Selected Resin Matrix Materials

This design note presents typical mechanical properties tabulated from industrial and governmental agencies' test programs. All data are correlated to specific products and all of the best known products are presented. The data include six epoxies, eight polyimides and one polyquinoxaline matrix material. Bron and graphite are the fiber reinforcements. Included are forty-two summaries of advanced (resin matrix) composite programs in existence in the United States. It is concluded that the selection of appropriate matrices, the geometric manner in which the fibers are incorporated in the matrix and the durability of the bond between fiber and matrix establish the end properties of the composite material and the performance of the fabricated structure.

Welhart, E. K.↗
NASA NTRS1975

Early results of the ATS-6 solar cell flight experiment

This paper presents preliminary ATS-6 solar-cell flight-experiment data through the first 247 days in synchronous orbit. The experiment is transmitting data on forty 2 x 2-cm solar cells representing 16 solar-cell configurations. The experiment is designed to study the effect of this orbit on select solar cells and cover-glass parameters such as solar-cell thickness and base resistivity, cover-glass thickness variation, new cover processes, and materials such as 7940 and 7070 integral covers as well as the FEP covers, the COMSAT 'violet' cell, and backside irradiation effects. The in-space solar-cell data indicate short-circuit currents are running higher by 1% to 8% than in measurements made with solar simulations; maximum power varied between -1% and +6%. Degradation of short-circuit current due to ultraviolet effects was determined to be about 2% after 50 days in orbit. All cells performed well through 247 days in orbit except the FEP-covered cells, which appear to have increased their rate of degradation during the eclipse season.

Goldhammer, L. J.↗
NASA NTRS1975

Ultraviolet solar identifications based on extended absorption series observed in the laboratory spectrum of Si I

The absorption spectrum of Si I in the wavelength region between 1500 and 1900 A has been photographed at high resolution. The silicon vapor was produced in a 122-cm-long King furnace at 1800 to 2300 C. Forty-two Rydberg series have been observed from the ground state terms 3p(2)3P and 1D to terms associated with the 3pns and 3pnd configurations. All of the series from these configurations with J less than 4 have been extended with the 3pnd 3D(3) levels reaching n = 56. Numerous perturbations have been observed. This laboratory work has provided the basis for extending the identification of silicon lines in the solar spectrum. Nearly all lines found in the laboratory spectrum are also found in rocket spectrograms of the solar chromosphere. More than 300 lines have been attributed to Si I. The excellent correlation between laboratory and solar Si I lines is illustrated.

Moore, C. E.↗
NASA NTRS1976

Interorganizational transfer of technology - A study of adoption of NASA innovations

The paper describes a study on the effects of top management support, various techno-economic factors, organizational climate, and decision-making modes on the adoption of NASA innovations. Field research consisted of interviews and questionnaires directed to sixty-five organizations. Forty-five test cases where different decisions for adoption of ideas for new products or processes were made on NASA Tech Briefs were studied in relation to the effects of various factors on the degree of success of adoption, including: (1) the degree of general connection of the technology to the firm's existing operation, (2) the specificity of the relationship between the technology and some existing and recognized problem, (3) the degree of urgency of the problem to which the technology was related, (4) maturity of technology available to implement the technology, (5) availability of personnel and financial resources to implement the technology, (6) degree of top management interest, (7) the use of confrontation in joint-decision, (8) the use of smoothing in decision-making, and (9) the use of forcing in decision-making. It was found that top managements interest was important in the product cases only, and that the success of process innovations was dependent on the quality of information and the specificity of the relationship between the technology and some recognized existing problem.

Chakrabarti, A. K.↗
NASA NTRS1975

The radio spectrum of Vela supernova and its implication on the propagation of cosmic rays from sources

A detailed analysis of the radio spectrum of the Vela supernova remnant has been carried out to show that the positive spectral shape below 80 MHz can be understood on the basis of Razin effect. This result requires most of the gas in the remnant to be stratified into high density clumps with intense magnetic fields and large cosmic ray densities. The free-free emission is found to be partly responsible for the observed flat radio spectrum. In order to account for both the gamma ray flux above 100 MeV and the radio spectrum, the equipartition between the cosmic ray density and magnetic field seems to break down. The total cosmic ray energy residing in the supernova is found to be about ten to the forty-ninth ergs, which is much smaller than the value obtained without taking into account the stratification of gas.

Stephens, S. A.↗
NASA NTRS1976

Polarization of the reflected light of asteroid 433 Eros

Linear polarizations measured for asteroid 433 Eros at various wavelengths and at solar phase angles ranging from 9 to 53 deg are presented. The polarization results are entirely typical of main-belt S asteroids, and indicate a dusty surface with geometric albedo 0.20. The derived effective diameter at photometric maximum is 21 km. Eros is quite uniform polarimetrically; no dependence on aspect is detected, and the polarization is shown to be constant during a single rotation with a precision of one part in forty.

Zellner, B.↗
NASA NTRS1976

Water vapor absorption of carbon dioxide laser radiation

An optoacoustic detector or spectrophone has been used to perform detailed measurements of the absorptivity of mixtures of water vapor in air. A (C-12) (O-16)2 laser was used as the source, and measurements were made at forty-nine different wavelengths from 9.2 to 10.7 microns. The details of the optoacoustic detector and its calibration are presented, along with a discussion of its performance characteristics. The results of the measurements of water vapor absorption show that the continuum absorption in the wavelength range covered is 5-10% lower than previous measurements.

Shumate, M. S.↗
NASA NTRS1978

Tube-weld inspection tool

Tool compares weld width with notch width. Weld is considered satisfactory if weld is wider than notch. Fiber optics permit inspection head to be completely rotated around tube for complete inspection of weld. Forty-five degree mirror mounted over notch aids in comparing notch and weld widths.

Stanford, H. B.↗