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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 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS1989

NDE of adhesive bonds and bondlines; Proceedings of the 1989 ASNT Fall Conference, Valley Forge, PA, Oct. 9-13, 1989

The conference presents papers on the Solid Propulsion Integrity Program, the NDE methodology of adhesive bond strength determination, and an interface layer model for ultrasonic inspection of adhesive bonds. Also considered are pulse/echo ultrasonic methods for inspecting bondlines, ultrasonic detection of kissing bonds in adhesive joints, and the NDE needs and requirements for SRM bondline inspection. Thermographic stress analysis of bonded joints is discussed as well as the filmless and real-time applications of holography.

Source record↗
NASA NTRS1990

Intelligent control and adaptive systems; Proceedings of the Meeting, Philadelphia, PA, Nov. 7, 8, 1989

Various papers on intelligent control and adaptive systems are presented. Individual topics addressed include: control architecture for a Mars walking vehicle, representation for error detection and recovery in robot task plans, real-time operating system for robots, execution monitoring of a mobile robot system, statistical mechanics models for motion and force planning, global kinematics for manipulator planning and control, exploration of unknown mechanical assemblies through manipulation, low-level representations for robot vision, harmonic functions for robot path construction, simulation of dual behavior of an autonomous system. Also discussed are: control framework for hand-arm coordination, neural network approach to multivehicle navigation, electronic neural networks for global optimization, neural network for L1 norm linear regression, planning for assembly with robot hands, neural networks in dynamical systems, control design with iterative learning, improved fuzzy process control of spacecraft autonomous rendezvous using a genetic algorithm.

Rodriguez, Guillermo↗
NASA NTRS1990

Sensor fusion II: Human and machine strategies; Proceedings of the Meeting, Philadelphia, PA, Nov. 6-9, 1989

Various papers on human and machine strategies in sensor fusion are presented. The general topics addressed include: active vision, measurement and analysis of visual motion, decision models for sensor fusion, implementation of sensor fusion algorithms, applying sensor fusion to image analysis, perceptual modules and their fusion, perceptual organization and object recognition, planning and the integration of high-level knowledge with perception, using prior knowledge and context in sensor fusion.

Schenker, Paul S.↗
NASA NTRS2013

Propulsion Overview of the Orion Pad Abort 1 (PA-1) Flight-Test Vehicle

The NASA Orion Flight Test Office was tasked with conducting a series of flight tests in several launch abort scenarios to certify that the Orion Launch Abort System is capable of delivering astronauts aboard the Orion Crew Module to a safe environment, away from a failed booster. The first of this series was the Orion Pad Abort 1 Flight-Test Vehicle, which was successfully flown on May 6, 2010 at the White Sands Missile Range in New Mexico. This presentation provides a concise overview of the three propulsive subsystems used on the Pad Abort 1 Flight-Test Vehicle. Although the Constellation program has been cancelled and the operational role of the Orion spacecraft has significantly evolved, lessons learned from Pad Abort 1 could certainly contribute to the vehicle architecture of many future human-rated space launch vehicles

Jones, Daniel S.↗
NASA NTRS1993

Supraoptimal carbon dioxide effects on growth of soybean [Glycine max (L.) Merr.]

In tightly closed environments used for human life support in space, carbon dioxide (CO2) partial pressures can reach 500 to 1000 Pa, which may be supraoptimal or toxic to plants used for life support. To study this, soybeans [Glycine max (L.) Merr. cvs. McCall and Pixie] were grown for 90 days at 50, 100, 200, and 500 Pa partial pressure CO2 (500, 1000, 2000, and 5000 ppm). Plants were grown using recirculating nutrient film technique with a 12-h photoperiod, a 26 degrees C/20 degrees C thermoperiod, and approximately 300 micromoles m-2 s-1 photosynthetic photon flux (PPF). Seed yield and total biomass were greatest at 100 Pa for cv. McCall, suggesting that higher CO2 levels were supraoptimal. Seed yield and total biomass for cv. Pixie showed little difference between CO2 treatments. Average stomatal conductance of upper canopy leaves at 50 Pa CO2 approximately 500 Pa > 200 Pa > 100 Pa. Total water use over 90 d for both cultivars (combined on one recirculating system) equalled 822 kg water for 100 Pa CO2, 845 kg for 50 Pa, 879 kg for 200 Pa, and 1194 kg for 500 Pa. Water use efficiences for both cultivars combined equalled 3.03 (g biomass kg-1 water) for 100 Pa CO2, 2.54 g kg-1 for 200 Pa, 2.42 g kg-1 for 50 Pa, and 1.91 g kg-1 for 500 Pa. The increased stomatal conductance and stand water use at the highest CO2 level (500 Pa) were unexpected and pose interesting considerations for managing plants in a tightly closed system where CO2 concentrations may reach high levels.

NASA Discipline Life Support Systems↗
DOE OSTI2020

Materials Data on MgPa3 by Materials Project

MgPa3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Mg is bonded to twelve Pa atoms to form MgPa12 cuboctahedra that share corners with four equivalent MgPa12 cuboctahedra, corners with eight equivalent PaMg4Pa8 cuboctahedra, edges with eight equivalent MgPa12 cuboctahedra, edges with sixteen equivalent PaMg4Pa8 cuboctahedra, faces with four equivalent MgPa12 cuboctahedra, and faces with fourteen PaMg4Pa8 cuboctahedra. All Mg–Pa bond lengths are 3.24 Å. There are two inequivalent Pa sites. In the first Pa site, Pa is bonded to four equivalent Mg and eight equivalent Pa atoms to form PaMg4Pa8 cuboctahedra that share corners with four equivalent PaMg4Pa8 cuboctahedra, corners with eight equivalent MgPa12 cuboctahedra, edges with twenty-four PaMg4Pa8 cuboctahedra, faces with six equivalent MgPa12 cuboctahedra, and faces with twelve PaMg4Pa8 cuboctahedra. All Pa–Pa bond lengths are 3.24 Å. In the second Pa site, Pa is bonded to four equivalent Mg and eight Pa atoms to form PaMg4Pa8 cuboctahedra that share corners with twelve equivalent PaMg4Pa8 cuboctahedra, edges with eight equivalent MgPa12 cuboctahedra, edges with sixteen PaMg4Pa8 cuboctahedra, faces with four equivalent MgPa12 cuboctahedra, and faces with fourteen PaMg4Pa8 cuboctahedra. All Pa–Pa bond lengths are 3.24 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PaFe3 by Materials Project

PaFe3 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are two inequivalent Pa sites. In the first Pa site, Pa is bonded to twelve Fe atoms to form PaFe12 cuboctahedra that share corners with six equivalent PaFe12 cuboctahedra, corners with twelve FePa4Fe8 cuboctahedra, edges with eighteen FePa4Fe8 cuboctahedra, faces with eight PaFe12 cuboctahedra, and faces with twelve FePa4Fe8 cuboctahedra. There are a spread of Pa–Fe bond distances ranging from 2.67–2.88 Å. In the second Pa site, Pa is bonded to twelve Fe atoms to form PaFe12 cuboctahedra that share corners with six equivalent PaFe12 cuboctahedra, corners with twelve FePa4Fe8 cuboctahedra, edges with eighteen FePa4Fe8 cuboctahedra, faces with eight PaFe12 cuboctahedra, and faces with twelve FePa4Fe8 cuboctahedra. There are a spread of Pa–Fe bond distances ranging from 2.67–2.87 Å. There are six inequivalent Fe sites. In the first Fe site, Fe is bonded to four Pa and eight Fe atoms to form distorted FePa4Fe8 cuboctahedra that share corners with four equivalent PaFe12 cuboctahedra, corners with fourteen FePa4Fe8 cuboctahedra, edges with six PaFe12 cuboctahedra, edges with twelve FePa4Fe8 cuboctahedra, faces with four PaFe12 cuboctahedra, and faces with sixteen FePa4Fe8 cuboctahedra. There are a spread of Fe–Fe bond distances ranging from 2.50–2.88 Å. In the second Fe site, Fe is bonded to four Pa and eight Fe atoms to form distorted FePa4Fe8 cuboctahedra that share corners with four equivalent PaFe12 cuboctahedra, corners with fourteen FePa4Fe8 cuboctahedra, edges with six PaFe12 cuboctahedra, edges with twelve FePa4Fe8 cuboctahedra, faces with four PaFe12 cuboctahedra, and faces with sixteen FePa4Fe8 cuboctahedra. There are a spread of Fe–Fe bond distances ranging from 2.49–2.85 Å. In the third Fe site, Fe is bonded to four Pa and eight Fe atoms to form distorted FePa4Fe8 cuboctahedra that share corners with four equivalent PaFe12 cuboctahedra, corners with fourteen FePa4Fe8 cuboctahedra, edges with six PaFe12 cuboctahedra, edges with twelve FePa4Fe8 cuboctahedra, faces with four PaFe12 cuboctahedra, and faces with sixteen FePa4Fe8 cuboctahedra. There are two shorter (2.76 Å) and two longer (2.77 Å) Fe–Fe bond lengths. In the fourth Fe site, Fe is bonded to four Pa and eight Fe atoms to form distorted FePa4Fe8 cuboctahedra that share corners with four equivalent PaFe12 cuboctahedra, corners with fourteen FePa4Fe8 cuboctahedra, edges with six PaFe12 cuboctahedra, edges with twelve FePa4Fe8 cuboctahedra, faces with four PaFe12 cuboctahedra, and faces with sixteen FePa4Fe8 cuboctahedra. There are a spread of Fe–Fe bond distances ranging from 2.50–2.88 Å. In the fifth Fe site, Fe is bonded to four Pa and eight Fe atoms to form distorted FePa4Fe8 cuboctahedra that share corners with four equivalent PaFe12 cuboctahedra, corners with fourteen FePa4Fe8 cuboctahedra, edges with six PaFe12 cuboctahedra, edges with twelve FePa4Fe8 cuboctahedra, faces with four PaFe12 cuboctahedra, and faces with sixteen FePa4Fe8 cuboctahedra. There are one shorter (2.49 Å) and one longer (2.86 Å) Fe–Fe bond lengths. In the sixth Fe site, Fe is bonded to four Pa and eight Fe atoms to form distorted FePa4Fe8 cuboctahedra that share corners with four equivalent PaFe12 cuboctahedra, corners with fourteen FePa4Fe8 cuboctahedra, edges with six PaFe12 cuboctahedra, edges with twelve FePa4Fe8 cuboctahedra, faces with four PaFe12 cuboctahedra, and faces with sixteen FePa4Fe8 cuboctahedra.

36 MATERIALS SCIENCE↗
NASA NTRS1995

Estimates of volumetric bone density from projectional measurements improve the discriminatory capability of dual X-ray absorptiometry

To determine whether estimates of volumetric bone density from projectional scans of the lumbar spine have weaker associations with height and weight and stronger associations with prevalent vertebral fractures than standard projectional bone mineral density (BMD) and bone mineral content (BMC), we obtained posteroanterior (PA) dual X-ray absorptiometry (DXA), lateral supine DXA (Hologic QDR 2000), and quantitative computed tomography (QCT, GE 9800 scanner) in 260 postmenopausal women enrolled in two trials of treatment for osteoporosis. In 223 women, all vertebral levels, i.e., L2-L4 in the DXA scan and L1-L3 in the QCT scan, could be evaluated. Fifty-five women were diagnosed as having at least one mild fracture (age 67.9 +/- 6.5 years) and 168 women did not have any fractures (age 62.3 +/- 6.9 years). We derived three estimates of "volumetric bone density" from PA DXA (BMAD, BMAD*, and BMD*) and three from paired PA and lateral DXA (WA BMD, WA BMDHol, and eVBMD). While PA BMC and PA BMD were significantly correlated with height (r = 0.49 and r = 0.28) or weight (r = 0.38 and r = 0.37), QCT and the volumetric bone density estimates from paired PA and lateral scans were not (r = -0.083 to r = 0.050). BMAD, BMAD*, and BMD* correlated with weight but not height. The associations with vertebral fracture were stronger for QCT (odds ratio [QR] = 3.17; 95% confidence interval [CI] = 1.90-5.27), eVBMD (OR = 2.87; CI 1.80-4.57), WA BMDHol (OR = 2.86; CI 1.80-4.55) and WA-BMD (OR = 2.77; CI 1.75-4.39) than for BMAD*/BMD* (OR = 2.03; CI 1.32-3.12), BMAD (OR = 1.68; CI 1.14-2.48), lateral BMD (OR = 1.88; CI 1.28-2.77), standard PA BMD (OR = 1.47; CI 1.02-2.13) or PA BMC (OR = 1.22; CI 0.86-1.74). The areas under the receiver operating characteristic (ROC) curves for QCT and all estimates of volumetric BMD were significantly higher compared with standard PA BMD and PA BMC. We conclude that, like QCT, estimates of volumetric bone density from paired PA and lateral scans are unaffected by height and weight and are more strongly associated with vertebral fracture than standard PA BMD or BMC, or estimates of volumetric density that are solely based on PA DXA scans.

Non-NASA Center↗