Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Quality control”

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 1,063 records · Page 59
All sourcesNASA NTRSDOE OSTI
NASA NTRS1987

VLSI-Chip Tester

Compact test set integrated in computer-aided design system. Test set performs functional tests on very-large-scale integrated (VLSI) circuits. Makes tests from points within VLSI chip as well as at input and output pins. Used for quality control and design; in latter capacity, checks internal logic functions on chip and feed results directly to computer-aided design system for correction. Also simulates operation of chip design before chip is made. VLSI Tester contains three power supplies, control logic, and standard multibus circuit board in aluminum chassis. Chassis fits under platform of microprobe station. Multibus board links tester to interactive terminals and to host computer.

Deutsch, Leslie J.↗
NASA NTRS1987

Assessing the Reliability of NDE

Versatile FORTRAN computer algorithm developed for calculating and plotting reliability of nondestructive evaluation (NDE) technique for inspection of flaws. Developed specifically to determine reliability of radiographic and ultrasonic methods for detection of critical flaws in structural ceramic materials. Reliability displayed in form of plot of probability of detection versus flaw size. NDE methods used in such applications as diagnostic medicine, quality control in industrial production, and prediction of failure in structural components.

Roth, Don J.↗
NASA NTRS1987

Determining Directions of Ultrasound in Solids

Ultrasound shadows cast by grooves. Improved method for determining direction of ultrasound in materials is shadow method using Scanning laser acoustic microscopy (SLAM). Direction of ultrasound calculated from dimensions of groove and portion of surface groove shields from ultrasound. Method has variety of applications in nontraditional quality-control applications.

Generazio, Edward R.↗
NASA NTRS1986

The real-time use of wind profilers in nowcasting

The program for Regional Observing and Forecasting Services (PROFS) has been using wind profile data in experimental forecast applications for over two years, mostly in the form of real-time color displays on the PROFS forecast workstation. The most ambitious test of the workstation to date, the 1985 PROFS Real-Time Experiment (RT-85), ran from 15 May to 23 August, 1985. The use of wind profiler products during this and previous experiments is described. Data from the experimental profiler network in Colorado and from the profiler in Oklahoma are in the form of hourly averages. Arriving data frequently contain errors whose origins range from interference by aircraft in the beams to highway truck traffic. Most of the irregularities are apparent through visual inspection of profiler wind observations plotted on a time-height cross section, but this method of quality control is inadequate if the intended uses of the data involve numerical calculations.

Smith, T. L.↗
NASA NTRS1985

Studies of lightning data in conjunction with geostationary satellite data

Since January, work has been proceeding on the first phase of this project: the creation of an extensive real-time lightning data base accessible via the Space Science and Engineering Center McIdas system. The purpose of this endeavor is two-fold: to enhance the availability and ease of access to lightning data among the various networks, governmental and research agencies; and to test the feasiblity and desirability of such efforts in succeeding years. The final steps in the creation of the necessary communications links, hardware, and software are in the process of being completed. Operations ground rules for access among the various users have been discussed and are being refined. While the research planned for the last year of the project will rely for the most part on archived, quality-controlled data from the various networks, the real-time data will provide a valuable first-look at potentially interesting case studies. For this purpose, tools are being developed on McIdas for display and analysis of the data as they become available. In conjunction with concurrent GOES real-time imagery, strike locations can be plotted, gridded and contoured, or displayed in various statistical formats including frequency distributions, histograms, and scatter plots. The user may also perform these functions in relation to arbitrarily defined areas on the satellite image. By mid-May these preparations for the access and analysis of real-time lightning data are expected to be complete.

Auvine, B.↗
NASA NTRS1985

Automated mesoscale winds derived from GOES multispectral imagery

An automated technique for extracting mesoscale winds from sequences of GOES visible infrared spin scan radiatiometer (VISSR) image pairs has been developed, tested extensively, and configured for quasi-real time research applications on the Atmospheric Sciences Division's research computing sytem. The entire system of computer codes was successfully vectorized for execution on an array processor resulting in job turnaround in less than 1 hour. An objective quality control system provides much greater than 99 percent accuracy in eliminating questionable wind estimates. Dynamical analysis of cloud wind divergence has revealed temporally consistent convergence centers on the meso-beta scale that are highly correlated with ongoing and future developing convective storms.

Wilson, G. S.↗
NASA NTRS1986

Cables and fire hazards

Besides describing the experiments conducted to develop a nonflammable cable, this article discusses several considerations regarding other hazards which might result from cable fires, particularly the toxicity and opacity of the fumes emitted by the burning cable. In addition, this article examines the effects of using the Oxygen Index as a gauge of quality control during manufacture.

Zanelli, C.↗
NASA NTRS1987

Management: A bibliography for NASA managers (supplement 21)

This bibliography lists 664 reports, articles and other documents introduced into the NASA scientific and technical information system in 1986. Items are selected and grouped according to their usefulness to the manager as manager. Citations are grouped into ten subject categories: human factors and personnel issues; management theory and techniques; industrial management and manufacturing; robotics and expert systems; computers and information management; research and development; economics, costs, and markets; logistics and operations management; reliability and quality control; and legality, legislation, and policy.

Source record↗
NASA NTRS1987

Detection of reflector surface error from near-field data: Effect of edge diffracted field

The surface accuracy of large reflector antennas must be maintained within certain tolerances if high gain/low sidelobe performance is to be achieved. Thus the measurement of the surface profile is an important part of the quality control procedure when constructing antennas of this type. An efficient method for surface profile measurement has been proposed, i.e., the reflector surface is calculated from the measured near-field phase data using the theory of geometric optics. For a surface profile calculation of this kind, it is necessary to know the margin of error built into the method of calculation. This will enable a specification of the tolerance from which the surface profile can be determined. When calculating the surface profile from near-field phase data, there are two main sources of error. The first is the measurement error in near-field phase data. The second arises from the edge diffracted fields that are superimposed on the reflected fields in the measured near-field data. The error in the calculated surface profile produced by the edge diffracted fields is examined.

Cherrette, Alan R.↗
NASA NTRS1987

Automated mesoscale winds determined from satellite imagery

A new automated technique for extracting mesoscale fields from GOES visible/infrared satellite imagery was developed. Quality control parameters were defined to allow objective editing of the wind fields. The system can produce equivalent or superior cloud wind estimates compared to the time consuming manual methods used on various interactive meteorological processing systems. Analysis of automated mesoscale cloud wind for a test case yields an estimated random error value one meter per second and produces both regional and mesoscale vector wind field structure and divergence patterns that are consistent in time and highly correlated with subsequent severe thunderstorm development.

Source record↗
NASA NTRS1986

A computer graphics pilot project - Spacecraft mission support with an interactive graphics workstation

The NASA Computer Graphics Pilot Project was undertaken to enhance the quality control, productivity and efficiency of mission support operations at the Goddard Operations Support Computing Facility. The Project evolved into a set of demonstration programs for graphics intensive simulated control room operations, particularly in connection with the complex space missions that began in the 1980s. Complex mission mean more data. Graphic displays are a means to reduce the probabilities of operator errors. Workstations were selected with 1024 x 768 pixel color displays controlled by a custom VLSI chip coupled to an MC68010 chip running UNIX within a shell that permits operations through the medium of mouse-accessed pulldown window menus. The distributed workstations run off a host NAS 8040 computer. Applications of the system for tracking spacecraft orbits and monitoring Shuttle payload handling illustrate the system capabilities, noting the built-in capabilities of shifting the point of view and rotating and zooming in on three-dimensional views of spacecraft.

Hagedorn, John↗
NASA NTRS1988

BASIC Programming In Water And Wastewater Analysis

Collection of computer programs assembled for use in water-analysis laboratories. First program calculates quality-control parameters used in routine water analysis. Second calculates line of best fit for standard concentrations and absorbances entered. Third calculates specific conductance from conductivity measurement and temperature at which measurement taken. Fourth calculates any one of four types of residue measured in water. Fifth, sixth, and seventh calculate results of titrations commonly performed on water samples. Eighth converts measurements, to actual dissolved-oxygen concentration using oxygen-saturation values for fresh and salt water. Ninth and tenth perform calculations of two other common titrimetric analyses. Eleventh calculates oil and grease residue from water sample. Last two use spectro-photometric measurements of absorbance at different wavelengths and residue measurements. Programs included in collection written for Hewlett-Packard 2647F in H-P BASIC.

Dreschel, Thomas↗
NASA NTRS1988

Nimbus 7 Solar Backscatter Ultraviolet (SBUV) spectral scan solar irradiance and Earth radiance product user's guide

The archived tape products from the spectral scan mode measurements of solar irradiance (SUNC tapes) and Earth radiance (EARTH tapes) by the Solar Backscatter UV (SBUV) instrument aboard Nimbus 7 are described. Incoming radiation from 160 to 400 nm is measured at intervals of 0.2 nm. The scan-to-scan repeatability of the solar irradiance measurements ranges from approximately 0.5 to 1 percent longward of 280 nm, to 2 percent around 210 nm and 4 percent near 175 nm. The repeatability of the Earth radiance values ranges from 2 to 3 percent at longer wavelengths and low zenith angles to 10 percent at shorter wavelengths and high zenith angles. The tape formats are described in detail, including file structure and contents of each type of record. Catalogs of the tapes and the time period covered are provided, along with lists of the days lacking solar irradiance measurements and the days dedicated to Earth radiance measurements. The method for production of the tapes is outlined and quality control measures are described. How radiances and irradiances are derived from the raw counts, the corrections for changes in instrument sensitivity, and related uncertainties are discussed.

Schlesinger, Barry M.↗
NASA NTRS1988

Investigation of the misfueling of reciprocating piston aircraft engines

The Aircraft Misfueling Detection Project was developed by the Goddard Space Flight Center/Wallops Flight Facility at Wallops Island, Virginia. Its purpose was to investigate the misfueling of reciprocating piston aircraft engines by the inadvertent introduction of jet fuel in lieu of or as a contaminant of aviation gasoline. The final objective was the development of a device(s) that will satisfactorily detect misfueling and provide pilots with sufficient warning to avoid injury, fatality, or equipment damage. Two devices have been developed and successfully tested: one, a small contamination detection kit, for use by the pilot, and a second, more sensitive, modified gas chromatograph for use by the fixed-base operator. The gas chromatograph, in addition to providing excellent quality control of the fixed-base operator's fuel handling, is a very good backup for the detection kit in the event it produces negative results. Design parameters were developed to the extent that they may be applied easily to commercial production by the aircraft industry.

Scott, J. Holland, Jr.↗
NASA NTRS1988

Management: A bibliography for NASA managers

This bibliography lists 653 reports, articles and other documents introduced into the NASA scientific and technical information system in 1987. Items are selected and grouped according to their usefulness to the manager as manager. Citiations are grouped into ten subject categories; human factors and personnel issues; management theory and techniques; industrial management and manufacturing; robotics and expert systems; computers and information management; research and development; economics, costs and markets; logistics and operations management, reliability and quality control; and legality, legislation, and policy.

Source record↗
NASA NTRS1987

Telerobotic control of a dextrous manipulator using master and six-DOF hand-controllers for space assembly and servicing tasks

Two studies were conducted evaluating methods of controlling a telerobot; bilateral force reflecting master controllers and proportional rate six degrees of freedom (DOF) hand controllers. The first study compared the controllers on performance of single manipulator arm tasks, a peg-in-the-hole task, and simulated satellite orbital replacement unit changeout. The second study, a Space Station truss assembly task, required simultaneous operation of both manipulator arms (all 12 DOFs) and complex multiaxis slave arm movements. Task times were significantly longer and fewer errors were committed with the hand controllers. The hand controllers were also rated significantly higher in cognitive and manual control workload on the two-arm task. The master controllers were rated significantly higher in physical workload. There were no significant differences in ratings of manipulator control quality.

O'Hara, John M.↗
NASA NTRS1988

Research on high energy density capacitor materials

The Pulsed Plasma thruster is the simplest of all electric propulsion devices. It is a pulsed device which stores energy in capacitors for each pulse. The lifetimes and energy densities of these capacitors are critical parameters to the continued use of these thrusters. This report presents the result of a research effort conducted by JPL into the materials used in capacitors and the modes of failure. The dominant failure mechanism was determined to be material breakdown precipitated by heat build-up within the capacitors. The presence of unwanted gas was identified as the source of the heat. An aging phenomena was discovered in polycarbonate based capacitors. CO build-up was noted to increase with the number of times the capacitor had been discharged. Improved quality control was cited as being essential for the improvement of capacitor lifetimes.

Somoano, Robert↗