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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 235 records · Page 13

Performance of a small annular turbojet combustor designed for low cost

Performance investigations were conducted on a combustor utilizing several cost-reducing innovations and designed for use in a low-cost 4448-N thrust turbojet engine for commercial light aircraft. Low-cost features included simple, air-atomizing fuel injectors; combustor liners of perforated sheet; and the use of inexpensive type 304 stainless-steel material. Combustion efficiencies at the cruise and sea-level-takeoff design points were approximately 97 and 98 percent, respectively. The combustor isothermal pressure loss was 6.3 percent at the cruise-condition diffuser inlet Mach number of 0.34. The combustor exit temperature pattern factor was less than 0.24 at both the cruise and sea-level-takeoff design points. The combustor exit average radial temperature profiles at all conditions were in very good agreement with the design profile.

Fear, J. S.↗

Pyrotechnic hazards classification and evaluation program test report. Heat flux study of deflagrating pyrotechnic munitions

A heat flux study of deflagrating pyrotechnic munitions is presented. Three tests were authorized to investigate whether heat flux measurements may be used as effective hazards evaluation criteria to determine safe quantity distances for pyrotechnics. A passive sensor study was conducted simultaneously to investigate their usefulness in recording events and conditions. It was concluded that heat flux measurements can effectively be used to evaluate hazards criteria and that passive sensors are an inexpensive tool to record certain events in the vicinity of deflagrating pyrotechnic stacks.

Fassnacht, P. O.↗

Electronic test and calibration circuits, a compilation

A wide variety of simple test calibration circuits are compiled for the engineer and laboratory technician. The majority of circuits were found inexpensive to assemble. Testing electronic devices and components, instrument and system test, calibration and reference circuits, and simple test procedures are presented.

Source record↗

Mapping of terrain by computer clustering techniques using multispectral scanner data and using color aerial film

Two clustering techniques were used for terrain mapping by computer of test sites in Yellowstone National Park. One test was made with multispectral scanner data using a composite technique which consists of (1) a strictly sequential statistical clustering which is a sequential variance analysis, and (2) a generalized K-means clustering. In this composite technique, the output of (1) is a first approximation of the cluster centers. This is the input to (2) which consists of steps to improve the determination of cluster centers by iterative procedures. Another test was made using the three emulsion layers of color-infrared aerial film as a three-band spectrometer. Relative film densities were analyzed using a simple clustering technique in three-color space. Important advantages of the clustering technique over conventional supervised computer programs are (1) human intervention, preparation time, and manipulation of data are reduced, (2) the computer map, gives unbiased indication of where best to select the reference ground control data, (3) use of easy to obtain inexpensive film, and (4) the geometric distortions can be easily rectified by simple standard photogrammetric techniques.

Smedes, H. W.↗

Investigation of methods for sterilization of potting compounds and mated surfaces

The feasibility of using formaldehyde-liberating synthetic resins or polymers for the sterilization of potting compounds, mated and occluded areas, and spacecraft surfaces was demonstrated. The detailed study of interrelated parameters of formaldehyde gas sterilization revealed that efficient cycle conditions can be developed for the sterilization of spacecraft components. It was determined that certain parameters were more important than others in the development of cycles for specific applications. The use of formaldehyde gas for the sterilization of spacecraft components provides NASA with a highly efficient method which is inexpensive, reproducible, easily quantitated, materials compatible, operationally simple, generally non-hazardous and not thermally destructive.

Tulius, J. J.↗

A class of orthogonal nonrecursive binomial filters.

The time- and frequency-domain properties of the orthogonal binomial sequences are presented. It is shown that these sequences, or digital filters based on them, can be generated using adders and delay elements only. The frequency-domain behavior of these nonrecursive binomial filters suggests a number of applications as low-pass Gaussian filters or as inexpensive bandpass filters.

Haddad, R. A.↗

ATS F&G pioneer application of space technology.

The Applications Technology Satellites will introduce an era of high-powered spacecraft without the limitations of the earlier small, low-powered satellites. To provide this high power, the two satellites will be equipped with high-gain, 30-foot diameter parabolic antennas. Another major innovation is the achievement of a tenth of a degree tracking accuracy. These new ATS spacecraft will eliminate the need for the immense ground stations required to communicate with satellites in synchronous orbits. The high-gain antenna will allow communication with simple inexpensive ground terminals, thereby permitting many advanced experiments not feasible in the past.

Gerwin, H.↗

Noise suppression by time exposure oscilloscope photography.

We describe a simple and inexpensive means of enhancing repetitive signals obscured by noise with roughly equal amplitude. The signal and noise are displayed on an oscilloscope, and we perform a time average over many traces by time exposure photography. If the oscilloscope triggering is synchronous with the signal, the result is a significant suppression of the offending noise.

Huchital, G. S.↗

A fast electron gun for study of atomic decays.

A fast electron gun with subnanosecond rise and decay times and 100 mA peak beam current has been developed for delayed coincidence studies of atomic decays. The gun is fabricated from an inexpensive tetrode nuvistor, only slightly modified. The electron gun system has been successfully used in a delayed concidence study of fast decays of ionized helium.

Sutton, J. F.↗

A measurement of the fast luminescent decays of the MV-50 LED.

The fast luminescent decay of the MV-50 GaAs doped Si light-emitting diode has been studied. This diode is found to provide a fast, inexpensive, bright, and convenient light source for the calibration of fast optical timing systems. A simple passive electronic module is described that allows driving the light source directly by a laboratory pulse generator.

Sutton, J. F.↗

Laser Doppler anemometer for water tunnel applications.

A laser Doppler anemometer for three-dimensional velocity measurement in liquids and gases under a wide range of laboratory conditions has been developed. The instrument is particularly well suited for water tunnel applications. It is portable, easily aligned, and inexpensive (excluding electronic units). It operates in backscatter or forward scatter mode. In both cases all optical components, including laser and photomultiplier, remain on a common base. The system has built-in traversing capability and an aiming device for visualizing the focal (test) point. Design details and representative velocity measurements are given.

Bossel, H. H.↗

Mission strategy for combined comet-asteroid flybys.

Review of the currently consolidating interest in one or more relatively inexpensive small body exploration missions, and discussion of a proposed ballistic flyby of two asteroids and the periodic comet Forbes, to be launched in 1977. Trajectory data and target encounter conditions are presented for a selected set of missions which are compatible with the propulsion capabilities of a modified Pioneer F & G spacecraft.

Brooks, D. R.↗

Remote measurements by telephone

Inexpensive device permits measurement and remote interrogation of variables such as voltage, temperature, pressure, or humidity by standard telephone equipment. Remote interrogation of wind direction and velocity, humidity, or water levels on flood-prone river are other possible representative uses for this device.

Miller, R. L.↗

Rapid detection of bacteria in foods and biological fluids

Simple and inexpensive apparatus, called "redox monitoring cell," rapidly detects presence of bacteria. Bacteria is detected by measuring drop in oxygen content in test solution. Apparatus consists of vial with two specially designed electrodes connected to sensitive voltmeter.

Fealey, R. D.↗

A versatile flammability test chamber

Relatively inexpensive test chamber safely tests flammability of most materials while allowing constant observation of test. Chamber can be used at various pressures, under controlled atmosphere, and is equipped with probes to vary distance from heat source to test object or to move it for observation from several different angles.

Springfield, C. L.↗

A vacuum chamber feedthrough

Simple and inexpensive microwave feedthrough has been designed which transfers 130 ns, 5kV pulse into vacuum chamber. Feedthrough may be used over wide range and is adaptable to most coaxial cables, since either multistrand or single strand center conductor cable can be used.

Brown, V. D.↗

Balloon-borne package temperature controller

Simple, inexpensive, lightweight enclosure traps upward long wave radiation of earth while reflecting harsh solar radiation in upper atmosphere. It warms enclosed instruments in cold regions and protects them from overheating during the day. Device can be attached to balloon system without any changes in experimental design.

Schach, M.↗