6,967 research outputs found

    Apollo experience report: Data management for postflight engineering evaluation

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    The Apollo management of data for postflight engineering evaluation is described. The sources of Apollo telemetry data, the control of data processing by a single data team, the data techniques used to assist in evaluation of the large quantity of data, and the operation of the data team before the mission and during the evaluation phase are described. The techniques used to ensure the output of valid data and to determine areas in which data were of questionable quality are also included

    Phillips and the Natural Gas Act

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    Data Recovery Efforts at the Millville Mill Site (41RK223), Rusk County, Texas

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    In September 1993, data recovery efforts were undertaken by Espey, Huston & Associates, Inc. (EH&A) of Austin, Texas, to mitigate the effects of lignite mining on site 41RK223 in Texas Utilities Mining Company\u27s Oak Hill/2280 Acre Mine permit area of north-central Rusk County, Texas. The data recovery efforts were planned and conducted in coordination with the Department of Antiquities Protection at the Texas Historical Commission (THC) and Mr. Matthew Tanner of TU Services. The site was originally recorded by EH&A during a 1989 survey of the Oak Hill/2280 Acre Mine permit area based on information received from local informants, Orville Todd and Herman Ballow. Both men recalled swimming as children in the vicinity of an old framework of heavy timbers submerged within Boggy Branch, a tributary to Mill Creek. Local history accounts suggested that the timbers were likely the remains of one of several old water-powered mills historically associated with the Mill Creek floodplain

    A study of psychrophilic organisms isolated from the manufacture and assembly areas of spacecraft to be used in the Viking mission

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    The ability of psychrophilic microorganisms to grow in some of the environmental conditions suggested for Mars is studied with particular attention given to the effects of moisture and nutrients on growth. Results of growth with the slide culture technique are presented and indicate that this technique can be a rapid and sensitive technique for demonstration of microbial growth under various environmental conditions. Additional soil samples have been obtained from Cape Kennedy, and results of these assays at various low temperatures for psychrophilic populations are presented. The heat resistance of some of the psychrophilic sporeformers have been determined. Psychrophilic organisms were isolated from the teflon ribbons at Cape Kennedy and characterization of these was begun. In addition, heat survivors from the teflon ribbons are being investigated, and partial characterizations of these are presented

    Response of Selected Microorganisms to Experimental Planetary Environments

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    Results of studies in anaerobic phosphorus metabolism are presented. Specific topics discussed include: (1) anaerobic utilization of PH3; (2) reduction of phosphate or phosphite; (3) isolation of organisms which utilize phosphite or phosphate anaerobically as a final hydrogen acceptor; and (4) the toxicity of PH3 to the organisms. Techniques of anaerobic microbiology associated with space hardware were also studied. These include: (1) the Brewer anaerobe jar/GasPak system; (2) a new procedure to grow aerobes and anaerobes simultaneously; (3) a culture medium to differentiate oblagate from facultative anaerobes; and (4) a procedure to quantitate O2 sensitivity of anaerobes

    A Monte Carlo investigation of thrust imbalance of solid rocket motor pairs

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    A technique is described for theoretical, statistical evaluation of the thrust imbalance of pairs of solid-propellant rocket motors (SRMs) firing in parallel. Sets of the significant variables, determined as a part of the research, are selected using a random sampling technique and the imbalance calculated for a large number of motor pairs. The performance model is upgraded to include the effects of statistical variations in the ovality and alignment of the motor case and mandrel. Effects of cross-correlations of variables are minimized by selecting for the most part completely independent input variables, over forty in number. The imbalance is evaluated in terms of six time - varying parameters as well as eleven single valued ones which themselves are subject to statistical analysis. A sample study of the thrust imbalance of 50 pairs of 146 in. dia. SRMs of the type to be used on the space shuttle is presented. The FORTRAN IV computer program of the analysis and complete instructions for its use are included. Performance computation time for one pair of SRMs is approximately 35 seconds on the IBM 370/155 using the FORTRAN H compiler

    The preparation and evaluation of high-purity, fine-grained tungsten and tungsten alloy castings summary report

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    High purity, cylindrical castings of high melting point materials such as tungsten and tungsten alloy

    Solid-propellant rocket motor internal ballistic performance variation analysis, phase 2

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    The Monte Carlo method was used to investigate thrust imbalance and its first time derivative throughtout the burning time of pairs of solid rocket motors firing in parallel. Results obtained compare favorably with Titan 3 C flight performance data. Statistical correlations of the thrust imbalance at various times with corresponding nominal trace slopes suggest several alternative methods of predicting thrust imbalance. The effect of circular-perforated grain deformation on internal ballistics is discussed, and a modified design analysis computer program which permits such an evaluation is presented. Comparisons with SRM firings indicate that grain deformation may account for a portion of the so-called scale factor on burning rate between large motors and strand burners or small ballistic test motors. Thermoelastic effects on burning rate are also investigated. Burning surface temperature is calculated by coupling the solid phase energy equation containing a strain rate term with a model of gas phase combustion zone using the Zeldovich-Novozhilov technique. Comparisons of solutions with and without the strain rate term indicate a small but possibly significant effect of the thermoelastic coupling

    Solid propellant rocket motor internal ballistics performance variation analysis, phase 3

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    Results of research aimed at improving the predictability of off nominal internal ballistics performance of solid propellant rocket motors (SRMs) including thrust imbalance between two SRMs firing in parallel are reported. The potential effects of nozzle throat erosion on internal ballistic performance were studied and a propellant burning rate low postulated. The propellant burning rate model when coupled with the grain deformation model permits an excellent match between theoretical results and test data for the Titan IIIC, TU455.02, and the first Space Shuttle SRM (DM-1). Analysis of star grain deformation using an experimental model and a finite element model shows the star grain deformation effects for the Space Shuttle to be small in comparison to those of the circular perforated grain. An alternative technique was developed for predicting thrust imbalance without recourse to the Monte Carlo computer program. A scaling relationship used to relate theoretical results to test results may be applied to the alternative technique of predicting thrust imbalance or to the Monte Carlo evaluation. Extended investigation into the effect of strain rate on propellant burning rate leads to the conclusion that the thermoelastic effect is generally negligible for both steadily increasing pressure loads and oscillatory loads

    Volunteer Growth in America: A Review of Trends Since 1974

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    The Corporation has produced a national report that for the first time tracks volunteering over a 30-year period. "Volunteer Growth in America: A Review of Trends Since 1974" illustrates how volunteering has rebounded to a 30-year high today -- rising by more than 32 percent over the past 16 years -- after declining between 1974 and 1989. The report found that older teenagers (ages 16-19) have more than doubled their time spent volunteering since 1989; that far from being a "Me Generation," that Baby Boomers are volunteering at sharply higher rates than did the previous generation at mid-life; and that the volunteer rate for Americans ages 65 years and over has increased 64 percent since 1974; and the proportion of Americans volunteering with an educational or youth service organization has seen a 63 percent increase just since just 1989. "Volunteer Growth in America" is based on statistics from the U.S. Census Bureau and the Bureau of Labor Statistics. The findings are encouraging while demonstrating that more engagement is needed to achieve a national goal of raising the number of volunteers from 65 million in 2005 to 75 million by 2010
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