Engineering topics

Schultz, D.

Publications and source records attributed to Schultz, D..

8 records

NASA NTRS1999

Baselining the New GSFC Information Systems Center: The Foundation for Verifiable Software Process Improvement

This paper describes a study performed at the Information System Center (ISC) in NASA Goddard Space Flight Center. The ISC was set up in 1998 as a core competence center in information technology. The study aims at characterizing people, processes and products of the new center, to provide a basis for proposing improvement actions and comparing the center before and after these actions have been performed. The paper presents the ISC, goals and methods of the study, results and suggestions for improvement, through the branch-level portion of this baselining effort.

Parra, A.↗

NASA NTRS1993

H2O(+) production rates of Comets Austin 1990 V and P/Halley 1986 III

High-spectral-resolution scans of H2O(+) emissions from Austin 1990 V were obtained. A simple model of the ion distribution in the FOV is used to determine a lower limit phi(H2O+) to the H2O(+) ion flux away from the nucleus for each night of observations. A similar analysis is applied to previous observations of H2O(+) emissions from Comet P/Halley 1986 III. It is found that the mean ratio is phi(H2O+)/Q(H2O) is 1.2 x exp -3 for Halley (solar minimum) and 2.6 x 10 exp -3 for Austin (solar maximum).

Schultz, D.↗

NASA NTRS1993

The O(1D) distribution of Comet Austin 1989c1 = 1990 V

Flat field images of Comet Austin 1990 V were obtained from the morning sky, and a log of the observations is presented. Absolute intensity calibrations of the comet images are obtained along with scans of the cometary forbidden O I 6300 emission. The O(1D) distribution of the comet is found, and the OH mean lifetime at 1 AU is determined to be (1.1 +/- 0.3) 10 exp 5 s.

Schultz, D.↗

NASA NTRS1992

Comet Austin (1989c1) O(1D) and H2O production rates

The dual-etalon Fabry-Perot spectrometer of Kitt Peak's McMath solar telescope has been used to conduct Comet Austin observations with spectral scan resolutions of 0.21 A; this sufficed for resolution of cometary forbidden O I 6300 A emissions from nearby NH2, as well as telluric emissions of the same type. For these data, an O(1D) production rate is obtained which is noted to be nearly model-independent. The H2O production rate is determined by taking into account the photodissociation of H2O and OH as sources of O(1D).

Schultz, D.↗

NASA NTRS1983

HOST liner cyclic facilities

The HOST Liner Cyclic Program is utilizing two types of test apparatus, rectangular box rigs and a full annular rig. To date two quartz lamp cyclic box rigs have been tested and a third is to begin testing in late October 1983. The box rigs are used to evaluate 5x8 inch rectangular linear samples. A 21 inch diameter outer liner simulator is also being built up for testing beginning in April 1984. All rigs are atmospheric rigs. The first box rig, a three 6-kVA lamp installation, was operated under adverse conditions to determine feasibility of using quartz lamps for cyclic testing. This work was done in December 1981 and looked promising. The second box rig, again using three 6-kVA lamps, was operated to obtain instrumentation durability information and initial data input to a Finite Element Model. This limited test program was conducted in August 1983. Five test plates were run. Instrumentation consisted of strain gages, thermocouples and thermal paint. The strain gages were found to fail at 1200 F as expected though plates were heated to 1700 F. The third box rig, containing four 6-kVA lamps, is in build up for testing to begin in late October 1983. In addition to 33 percent greater power input, this rig has provision for 400 F backside line cooling air and a viewing port suitable for IR camera viewing. The casing is also water cooled for extended durability.

Schultz, D.↗

NASA NTRS1982

HOST liner cyclic facilities: Facility description

A quartz lamp box, a quartz lamp annular rig, and a low pressure liner cyclic can rig planned for liner cyclic tests are described. Special test instrumentation includes an IR-TV camera system for measuring liner cold side temperatures, thin film thermocouples for measuring liner hot side temperatures, and laser and high temperature strain gages for obtaining local strain measurements. A plate temperature of 2,000 F was obtained in an initial test of an apparatus with three quartz lamps. Lamp life, however, appeared to be limited for the standard commercial quartz lamps available. The design of vitiated and nonvitiated preheaters required for the quartz lamp annular rig and the cyclic can test rigs is underway.

Schultz, D.↗

NASA NTRS1977

Landsat imagery for surface-mine inventory

The feasibility of using Landsat imagery for routine monitoring of surface mining and reclamation was tested in a two-county (1541 sq km) area of western Maryland. Two digital analysis methods were studied. The first, a four-band analysis distinguishing various strip mine associated classes and conditions, proved useful, but has limited extendibility over a seasonal or annual period. In the second approach, a band-ratio method was developed for measuring disturbed surface areas, and it proved to be both temporally and geographically extendible. For mines ranging between 31 and 244 acres, the measurement accuracy of total affected acreage was 92%. The use of Landsat satellite data together with multilevel sampling of aircraft and field verification inspections has shown that multispectral analysis of digital data is an effective means of monitoring the progress of surface mining operations.

Anderson, A. T.↗

NASA NTRS1976

Satellite data for surface-mine inventory

To determine the feasibility of satellite data for surface-mine inventory, particularly as it applies to coal, a case study was conducted in Maryland. A band-ratio method was developed to measure disturbed surface areas, and it proved to be extendible both temporally and geographically. This method was used to measure area changes in the region over three time periods from September 1972 through July 1974 and to map the entire two-county area for 1973. For mines ranging between 31 and 244 acres (12 to 98 hectares) the measurement accuracy of total affected acreage was determined to be 92%. Mines of 120 acres (50 hectares) and larger were measured with greater accuracy, some within one percent of the actual area. The ability to identify, classify, and measure strip-mine surfaces in a two-county area (1,541 square kilometers - 595 square miles) of western Maryland was demonstrated through the use of computer processing. On the basis of these results the use of LANDSAT satellite data and multilevel sampling of aircraft and field verification inspections, multispectral analysis of digital data is shown to be an effective, rapid, and accurate means of monitoring the surface mining cycle.

Anderson, A. T.↗