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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 1,639 records · Page 91
All sourcesNASA NTRSDOE OSTI
NASA NTRS1991

NASA's flight-technological development program - A 650 Mbps laser communications testbed

A 650 Mbps laser communications testbed under construction for the development of flight qualifiable hardware suitable for near-term operation on geosynchronous-to-geosynchronous crosslink missions is presented. The program's primary purpose is to develop and optimize laser communications unique subsystems. Requirements for the testbed experiments are to optimize the acquisition processes, to fully simulate the long range (up to 21,000 km) and the fine tracking characteristics of two narrow-beam laser communications terminals, and to fully test communications performance which will include average and burst bit error rates, effects of laser diode coalignment, degradation due to internal and external stray light, and the impact of drifts in the optical components.

Hayden, W. L.↗
NASA NTRS1997

NASA's Involvement in Technology Development and Transfer: The Ohio Hybrid Bus Project

A government and industry cooperative is using advanced power technology in a city transit bus that will offer double the fuel economy, and reduce emissions to one tenth of government standards. The heart of the vehicle's power system is a natural gas fueled generator unit. Power from both the generator and an advanced energy storage system is provided to a variable speed electric motor attached to the rear drive axle. A unique aspect of the vehicle's design is its use of "super" capacitors for recovery of energy during braking. This is the largest vehicle ever built using this advanced energy recovery technology. This paper describes the project goals and approach, results of its system performance modeling, and the status of the development team's effort.

Viterna, Larry A.↗
NASA NTRS1998

Thickness-Independent Ultrasonic Imaging Applied to Abrasive Cut-Off Wheels: An Advanced Aerospace Materials Characterization Method for the Abrasives Industry. A NASA Lewis Research Center Technology Transfer Case History

Abrasive cut-off wheels are at times unintentionally manufactured with nonuniformity that is difficult to identify and sufficiently characterize without time-consuming, destructive examination. One particular nonuniformity is a density variation condition occurring around the wheel circumference or along the radius, or both. This density variation, depending on its severity, can cause wheel warpage and wheel vibration resulting in unacceptable performance and perhaps premature failure of the wheel. Conventional nondestructive evaluation methods such as ultrasonic c-scan imaging and film radiography are inaccurate in their attempts at characterizing the density variation because a superimposing thickness variation exists as well in the wheel. In this article, the single transducer thickness-independent ultrasonic imaging method, developed specifically to allow more accurate characterization of aerospace components, is shown to precisely characterize the extent of the density variation in a cut-off wheel having a superimposing thickness variation. The method thereby has potential as an effective quality control tool in the abrasives industry for the wheel manufacturer.

Roth, Don J.↗
NASA NTRS1999

How to Improve SBIR Phase 3 Technology Commercialization Effectiveness: A NASA Glenn Internal Assessment

Governmental departments and agencies with responsibilities for implementing the Small Business Innovative Research program under the auspices of the Small Business Administration, are now required to be more accountable for phase 3 performance. At NASA Glenn Research Center, internal, one-on-one interviews were conducted with seven contracting officer technical representatives who have managed one or more SBIR contracts through completion of phase 2. A questionnaire consisting of nineteen questions was formulated and used for the above purpose. This self-assessment produced several comments, conclusions, and recommendations for consideration and potential application.

Horsham, Gary A. P.↗
NASA NTRS2000

Mars Program Independent Assessment Team Report

The Mars Climate Orbiter failed to achieve Mars orbit on September 23, 1999. On December 3, 1999, Mars Polar Lander and two Deep Space 2 microprobes failed. As a result, the NASA Administrator established the Mars Program Independent Assessment Team (MPIAT) with the following charter: 1) Review and analyze successes and failures of recent Mars and Deep Space Missions which include: a) Mars Global Surveyor, b) Mars Climate Orbiter, c) Pathfinder, d) Mars Polar Lander, e) Deep Space 1, and f) Deep Space 2; 2) Examine the relationship between and among, NASA Jet Propulsion Laboratory (JPL), California Institute of Technology (Caltech), NASA Headquarters, and industry partners; 3) Assess effectiveness of involvement of scientists; 4) Identify lessons learned from successes and failures; 5) Review revised Mars Surveyor Program to assure lessons learned are utilized; 6) Oversee Mars Polar Lander and Deep Space 2 failure reviews; and 7) Complete by March 15, 2000. In-depth reviews were conducted at NASA Headquarters, JPL, and Lockheed Martin Astronautics (LMA). Structured reviews, informal sessions with numerous Mars Program participants, and extensive debate and discussion within the MPIAT establish the basis for this report. The review process began on January 7, 2000, and concluded with a briefing to the NASA Administrator on March 14, 2000. This report represents the integrated views of the members of the MPIAT who are identified in the appendix. In total, three related reports have been produced: a summary report, this report entitled "Mars Program Independent Assessment Team Report," and the "Report on the Loss of the Mars Polar Lander and Deep Space 2 Missions".

Young, Thomas↗
NASA NTRS2000

Support to NASA's Advanced Space Technology Program

During the period of May through September 2000, Lee & Associates, LLC completed the following tasks as specified in the purchase order SOW: Assessment of current processes and structure and recommended improvements; Reviewed and commented on restructure options; Participated in closure of the Fastrac Delta Critical Design Review actions; Participated in the Fastrac Test readiness review (TRR) process for test planned at SSC and Rocketdyne; and Participated in the investigation of any anomalies identified during the Fastrac engine test data reviews.

Goetz, Otto↗
NASA NTRS2003

Investigation of electrolyte measurement in diluted whole blood using spectroscopic and chemometric methods

The feasibility of using near-infrared (NIR) spectroscopy in combination with partial least-squares (PLS) regression was explored to measure electrolyte concentration in whole blood samples. Spectra were collected from diluted blood samples containing randomized, clinically relevant concentrations of Na+, K+, and Ca2+. Sodium was also studied in lysed blood. Reference measurements were made from the same samples using a standard clinical chemistry instrument. Partial least squares (PLS) was used to develop calibration models for each ion with acceptable results (Na+, R2 = 0.86, CVSEP = 9.5 mmol/L; K+, R2 = 0.54, CVSEP = 1.4 mmol/L; Ca2+, R2 = 0.56, CVSEP = 0.18 mmol/L). Slightly improved results were obtained using a narrower wavelength region (470-925 nm) where hemoglobin, but not water, absorbed indicating that ionic interaction with hemoglobin is as effective as water in causing measurable spectral variation. Good models were also achieved for sodium in lysed blood, illustrating that cell swelling, which is correlated with sodium concentration, is not required for calibration model development.

Non-NASA Center↗
NASA NTRS2003

MRI of the lung gas-space at very low-field using hyperpolarized noble gases

In hyperpolarized (HP) noble-gas magnetic resonance imaging, large nuclear spin polarizations, about 100,000 times that ordinarily obtainable at thermal equilibrium, are created in 3He and 129Xe. The enhanced signal that results can be employed in high-resolution MRI studies of void spaces such as in the lungs. In HP gas MRI the signal-to-noise ratio (SNR) depends only weakly on the static magnetic field (B(0)), making very low-field (VLF) MRI possible; indeed, it is possible to contemplate portable MRI using light-weight solenoids or permanent magnets. This article reports the first in vivo VLF MR images of the lungs in humans and in rats, obtained at a field of only 15 millitesla (150 Gauss).

NASA Discipline Life Sciences Technologies↗
NASA NTRS2003

Noninvasive, near infrared spectroscopic-measured muscle pH and PO2 indicate tissue perfusion for cardiac surgical patients undergoing cardiopulmonary bypass

OBJECTIVE: To determine whether near infrared spectroscopic measurement of tissue pH and Po2 has sufficient accuracy to assess variation in tissue perfusion resulting from changes in blood pressure and metabolic demand during cardiopulmonary bypass. DESIGN: Prospective clinical study. SETTING: Academic medical center. SUBJECTS: Eighteen elective cardiac surgical patients. INTERVENTION: Cardiac surgery under cardiopulmonary bypass. MEASUREMENTS AND MAIN RESULTS: A near infrared spectroscopic fiber optic probe was placed over the hypothenar eminence. Reference Po2 and pH sensors were inserted in the abductor digiti minimi (V). Data were collected every 30 secs during surgery and for 6 hrs following cardiopulmonary bypass. Calibration equations developed from one third of the data were used with the remaining data to investigate sensitivity of the near infrared spectroscopic measurement to physiologic changes resulting from cardiopulmonary bypass. Near infrared spectroscopic and reference pH and Po2 measurements were compared for each subject using standard error of prediction. Near infrared spectroscopic pH and Po2 at baseline were compared with values during cardiopulmonary bypass just before rewarming commenced (hypotensive, hypothermic), after rewarming (hypotensive, normothermic) just before discontinuation of cardiopulmonary bypass, and at 6 hrs following cardiopulmonary bypass (normotensive, normothermic) using mixed-model analysis of variance. Near infrared spectroscopic pH and Po2 were well correlated with the invasive measurement of pH (R2 =.84) and Po2 (R 2 =.66) with an average standard error of prediction of 0.022 +/- 0.008 pH units and 6 +/- 3 mm Hg, respectively. The average difference between the invasive and near infrared spectroscopic measurement was near zero for both the pH and Po2 measurements. Near infrared spectroscopic Po2 significantly decreased 50% on initiation of cardiopulmonary bypass and remained depressed throughout the bypass and monitored intensive care period. Near infrared spectroscopic pH decreased significantly during cardiopulmonary bypass, decreased significantly during rewarming, and remained depressed 6 hrs after cardiopulmonary bypass. Diabetic patients responded differently than nondiabetic subjects to cardiopulmonary bypass, with lower muscle pH values (p =.02). CONCLUSIONS: Near infrared spectroscopic-measured muscle pH and Po2 are sensitive to changes in tissue perfusion during cardiopulmonary bypass.

Non-NASA Center↗
NASA NTRS2002

Work and fatigue characteristics of unsuited and suited humans during isolated isokinetic joint motions

The effects of a pressurized suit on human performance were investigated. The suit is known as an Extra-Vehicular Mobility Unit (EMU) and is worn by astronauts while working outside their spacecraft in a low earth orbit. Isolated isokinetic joint torques of three female and three male subjects (all experienced users of the suit in 1G gravity) were measured while working at 100% and 80% of their maximum voluntary torque (MVT, which is synonymous with maximum voluntary contraction (MVC)). It was found that the average decrease in the total amount of work (the sum of the work in each repetition until fatigue) done when the subjects were wearing the EMU were 48% and 41% while working at 100% and 80% MVT, respectively. There is a clear relationship between the MVT and the time and amount of work done until fatigue. Here, the time to fatigue is defined as the ending time of the repetition for which the computed work done during that repetition dropped below 50% of the work done during the first repetition. In general the stronger joints took longer to fatigue and did more work than the weaker joints. It was found that the EMU decreases the work output at the wrist and shoulder joints the most, due to the EMU joint geometry. The EMU also decreased the joint range of motion. The average total amount of work done by the test subjects increased by 5.2% (20.4%) for the unsuited (suited) case, when the test subjects decreased the level of effort from 100% to 80% MVT. Also, the average time to fatigue increased by 9.2% (25.6%) for the unsuited (suited) case, when the test subjects decreased the level of effort from 100% to 80% MVT. It was also found that the experimentally measured torque decay could be predicted by a logarithmic equation. The absolute average errors in the predictions were found to be 18.3% and 18.9% for the unsuited and suited subjects, respectively, when working at 100% MVT, and 22.5% and 18.8% for the unsuited and suited subjects, respectively, when working at 80% MVT. These results could be very useful in the design of future EMU suits and the planning of Extra-Vehicular Activity (EVA) for the future International Space Station assembly operations.

NASA Discipline Life Sciences Technologies↗
NASA NTRS2002

Capillary electrophoresis-electrochemistry microfluidic system for the determination of organic peroxides

A microfluidic analytical system for the separation and detection of organic peroxides, based on a microchip capillary electrophoresis device with an integrated amperometric detector, was developed. The new microsystem relies on the reductive detection of both organic acid peroxides and hydroperoxides at -700 mV (vs. Ag wire/AgCl). Factors influencing the separation and detection processes were examined and optimized. The integrated microsystem offers rapid measurements (within 130 s) of these organic-peroxide compounds, down to micromolar levels. A highly stable response for repetitive injections (RSD 0.35-3.12%; n = 12) reflects the negligible electrode passivation. Such a "lab-on-a-chip" device should be attractive for on-site analysis of organic peroxides, as desired for environmental screening and industrial monitoring.

NASA Discipline Life Sciences Technologies↗
NASA NTRS1998

Pulsed Plasma Thruster Technology Development and Flight Demonstration Program

Because of anticipated near- and far-term mission needs for innovative new electric propulsion technologies, the NASA On-Board Propulsion program is sponsoring NASA Lewis Research Centers' Pulsed Plasma Thruster (PPT) technology development program to rapidly advance PPT technology. This is a joint effort of Lewis' On-Board Propulsion Branch and Space Flight Project Branch. Building on state-of-the-art technology developed and flown in the 1970's and 1980's for Department of Defense missions, newly developed PPT program designs are realizing significant gains in system mass reduction, thrust to mass ratio, total impulse to mass ratio, and variability of impulse bit.

Peterson, Todd T.↗
NASA NTRS2004

Polymer-carbon black composite sensors in an electronic nose for air-quality monitoring

An electronic nose that uses an array of 32 polymer-carbon black composite sensors has been developed, trained, and tested. By selecting a variety of chemical functionalities in the polymers used to make sensors, it is possible to construct an array capable of identifying and quantifying a broad range of target compounds, such as alcohols and aromatics, and distinguishing isomers and enantiomers (mirror-image isomers). A model of the interaction between target molecules and the polymer-carbon black composite sensors is under development to aid in selecting the array members and to enable identification of compounds with responses not stored in the analysis library.

NASA Discipline Life Sciences Technologies↗
NASA NTRS1996

On Board Processor Development for NASA's Advanced Radar Technology Program

This paper reports a preliminary study result of an on-board spaceborne SAR processor. It consists of a processing requirement analysis, functional specifications on custom hardware, and consideration on implementation approaches. Finally, a minimum version of this on-board processor designed for performance evaluation and for partial demonstration is illustrated.

SAR radar on-board processing spacecraft mapping i↗
NASA NTRS2012

Cameras Improve Navigation for Pilots, Drivers

Advanced Scientific Concepts Inc. (ASC), of Santa Barbara, California, received SBIR awards and other funding from the Jet Propulsion Laboratory, Johnson Space Center, and Langley Research Center to develop and refine its 3D flash LIDAR technologies for space applications. Today, ASC's NASA-derived technology is sold to assist with collision avoidance, navigation, and object tracking.

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