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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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Cryogenic properties of polymers - NASA/Case Conference, Cleveland, April 1967
Scale model performance tests on automatically activated silver zinc battery for deep space exploration
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The feasibility of developing a Mossbauer survey meter for geophysical prospecting was investigated. Various critical requirements that will have to be met by the source and absorber crystals in such an instrument were identified. It was concluded that a survey meter based on (Rh-103 resonance (40 kev) yields Rh-103) isomeric transition is feasible and should be developed.
There are no author-identified significant results in this report.
There are no author-identified significant results in this report.
The design, performance and safety of a fully engineered, selfcontained Li/SOCl2 battery as the power source for underwater applications. In addition to meeting the performance standards of the end user this battery is successfully tested under the rigorous safety conditions of NAVSEA Instruction 9310.1A for use on land, aircraft and surface ships.
A network architecture called Highball and a preliminary design for a prototype, wide-area data network designed to operate at speeds of 1 Gbps and beyond are described. It is intended for applications requiring high speed burst transmissions where some latency between requesting a transmission and granting the request can be anticipated and tolerated. Examples include real-time video and disk-disk transfers, national filestore access, remote sensing, and similar applications. The network nodes include an intelligent crossbar switch, but have no buffering capabilities; thus, data must be queued at the end nodes. There are no restrictions on the network topology, link speeds, or end-end protocols. The end system, nodes, and links can operate at any speed up to the limits imposed by the physical facilities. An overview of an initial design approach is presented and is intended as a benchmark upon which a detailed design can be developed. It describes the network architecture and proposed access protocols, as well as functional descriptions of the hardware and software components that could be used in a prototype implementation. It concludes with a discussion of additional issues to be resolved in continuing stages of this project.
The CWRU Seal/Bearing test facility is shown along with the revised force measuring system. This facility has recently been retrofitted with a high pressure, high flow oil system. The high pressure high flow water system remains in place to test seals. Also, a new high flow air system is now installed. Thus, testing to determine static and dynamic properties can now be performed using oil, water, or air on this single facility. The oil system is currently being used to determine rotordynamic properties of a NASA four pocket hydrostatic journal bearing. The revised dual system force measuring configuration is performing with excellent accuracy. That is, the dynamic force measurements are made simultaneously with two independent systems, one with piezoelectric load cells and the other with strain gage load cells. The difference is less than 2 pct. between these two sets of load cell measurements on recent tests with a static eccentricity set close to zero and an orbit radius of 0.0004 inch. The extracted stiffness, damping and inertia coefficients is given for the test conditions shown, as extracted from the two independent dynamic force measurements.
BACKGROUND: Chronic cardiac unloading of the normal heart results in the reduction of left ventricular (LV) mass, but effects on myocyte contractile function are not known. METHODS AND RESULTS: Cardiac unloading and reduction in LV mass were induced by heterotopic heart transplantation to the abdominal aorta in isogenic rats. Contractility and [Ca(2+)](i) regulation in LV myocytes were studied at both 2 and 5 weeks after transplantation. Native in situ hearts from recipient animals were used as the controls for all experiments. Contractile function indices in myocytes from 2-week unloaded and native (control) hearts were similar under baseline conditions (0.5 Hz, 1.2 mmol/L [Ca(2+)](o), and 36 degrees C) and in response to stimulation with high [Ca(2+)](o) (range 2.5 to 4.0 mmol/L). In myocytes from 5-week unloaded hearts, there were no differences in fractional cell shortening and peak-systolic [Ca(2+)](i) at baseline; however, time to 50% relengthening and time to 50% decline in [Ca(2+)](i) were prolonged compared with controls. Severe defects in fractional cell shortening and peak-systolic [Ca(2+)](i) were elicited in myocytes from 5-week unloaded hearts in response to high [Ca(2+)](o). However, there were no differences in the contractile response to isoproterenol between myocytes from unloaded and native hearts. In 5-week unloaded hearts, but not in 2-week unloaded hearts, LV protein levels of phospholamban were increased (345% of native heart values). Protein levels of sarcoplasmic reticulum Ca(2+) ATPase and the Na(+)/Ca(2+) exchanger were not changed. CONCLUSIONS: Chronic unloading of the normal heart caused a time-dependent depression of myocyte contractile function, suggesting the potential for impaired performance in states associated with prolonged cardiac atrophy.
OBJECTIVES: To validate a simplified estimate of peak power (SPP) against true (invasively measured) peak instantaneous power (TPP), to assess the feasibility of measuring SPP during exercise and to correlate this with functional capacity. DESIGN: Development of a simplified method of measurement and observational study. SETTING: Tertiary referral centre for cardiothoracic disease. SUBJECTS: For validation of SPP with TPP, seven normal dogs and four dogs with dilated cardiomyopathy were studied. To assess feasibility and clinical significance in humans, 40 subjects were studied (26 patients; 14 normal controls). METHODS: In the animal validation study, TPP was derived from ascending aortic pressure and flow probe, and from Doppler measurements of flow. SPP, calculated using the different flow measures, was compared with peak instantaneous power under different loading conditions. For the assessment in humans, SPP was measured at rest and during maximum exercise. Peak aortic flow was measured with transthoracic continuous wave Doppler, and systolic and diastolic blood pressures were derived from brachial sphygmomanometry. The difference between exercise and rest simplified peak power (Delta SPP) was compared with maximum oxygen uptake (VO(2)max), measured from expired gas analysis. RESULTS: SPP estimates using peak flow measures correlated well with true peak instantaneous power (r = 0.89 to 0.97), despite marked changes in systemic pressure and flow induced by manipulation of loading conditions. In the human study, VO(2)max correlated with Delta SPP (r = 0.78) better than Delta ejection fraction (r = 0.18) and Delta rate-pressure product (r = 0.59). CONCLUSIONS: The simple product of mean arterial pressure and peak aortic flow (simplified peak power, SPP) correlates with peak instantaneous power over a range of loading conditions in dogs. In humans, it can be estimated during exercise echocardiography, and correlates with maximum oxygen uptake better than ejection fraction or rate-pressure product.
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Selection of quality seeds in breeding programs can significantly improve seedling productivity. Germination and biochemical analyses on seeds from ten natural populations of maritime pine (Pinus pinaster Ait.) in Morocco reveals significant differences among populations in seed weight, germination characters and protein content in both dry seeds and megagametophytes. During germination, the mobilization of protein content in megagametophyte is significantly different among populations than sugar content. A strong positive correlation between the germination capacity and the protein content in both dry seeds and megagametophytes indicates that the best populations in term of germination capacity may also be the richest in protein content. The present study finds that seed weight is not a good indicator for quality seed selection, nor is it recommended to increase the degree of germinability. Our results suggest that the pine population in southern Morocco might have adapted to drought conditions as it is characterized by heavy seed weight and lower speed of protein content mobilization in megagametophyte compared to northern populations growing in temperate climate.
Despite the significant value of the southeastern United States' red drum (Sciaenops ocellatus) fishery, there is a lack of clinical blood chemistry data. This was the first study to assess plasma glucose values as an indicator of stress response to evaluate variation and the effect of reproductive activity for wild adult red drum in Florida. Red drum (n=126) were collected from NASA's Kennedy Space Center waters during three reproductive periods in 2011. Samples were obtained from the branchial vessels of the gill arch. Plasma glucose levels were significantly different among reproductive periods, with the highest mean values recorded during the spawning period, September- October (38.23 mg / dL +/- 10.0). The glucose range was 17 - 69 mg / dL. Glucose values were lower during all three periods than previous values recorded for cultured or captive red drum studies. This may indicate that fish from this population were under less stress than other populations previously sampled.
The Florida Everglades formed from sawgrass and other aquatic plant remains that have accumulated over thousands of years and is a patterned peatland. The region was initially drained for agricultural and urban development in the late 1800s by the lowering of Lake Okeechobee water levels through canal drainage. Over the course of the past century, the Everglades has further been altered by the construction of canals and levees to provide control of Lake Okeechobee and Everglades water levels. The drainage has caused the loss of much of the peat of the Everglades by peat fires and microbial oxidation, much of it occurring between the 1880s and the 1950s. Plans for Everglades restoration are designed to provide additional water to flow through the remaining Everglades. Additional water into the Everglades would prevent further peat loss by reducing oxidation and encouraging the accretion of peat that has been lost. This potentially could result in the sequestration of significant quantities of atmospheric carbon. We used historic records to determine how much peat was there originally and how much has been lost. Over the past century and a half, approximately 50% of the original Everglades has been lost to agricultural and urban development. In addition, much of the peat in the remaining Everglades Protection Area has been lost. We used Geographic Information Systems technologies to determine the volume and mass of peat, the mass of carbon for each of the predrainage landscapes as well as the current Everglades regions. To do this, historical and current surveys within the Everglades were used to create elevation maps. With these maps, along with a bedrock contour map of south Florida, and soils data from the USEPA, we estimated Everglades peat characteristics. These calculations provide rough, quantitative estimates of the historical Everglades, its current condition, and the changes in the peat soil that have taken place since the 19th century. Given the uncertainties in the hindcasting of some of these data sets, this analysis provides rough estimates for the peat volumes and related constituents. Our calculations indicate that the current Everglades roughly contains less than 24% of theoriginal peat volume, 17% of its mass and 19% of its carbon. The work described was fully supported by the South Florida Water Management District, West Palm Beach, FL
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