Integral Launch and Reentry Vehicle - Executive Summary Final Report

Characteristics of integral launch and reentry vehicles - executive summar

An evaluation of the total quality management implementation strategy for the advanced solid rocket motor project at NASA's Marshall Space Flight Center

An evaluation of the NASA's Marshall Space Flight Center (MSFC) strategy to implement Total Quality Management (TQM) in the Advanced Solid Rocket Motor (ASRM) Project is presented. The evaluation of the implementation strategy reflected the Civil Service personnel perspective at the project level. The external and internal environments at MSFC were analyzed for their effects on the ASRM TQM strategy. Organizational forms, cultures, management systems, problem solving techniques, and training were assessed for their influence on the implementation strategy. The influence of ASRM's effort was assessed relative to its impact on mature projects as well as future projects at MSFC

Space processing of chalcogenide glass

A program was conducted to develop the technique of space processing for chalcogenide glass, and to define the process and equipment necessary. In the course of this program, successful long term levitation of objects in a 1-g environment was achieved. Glass beads 4 mm diameter were containerless melted and fused together

On relative supernova rates and nucleosynthesis roles

It is shown that the Ni-56-Fe-56 observed in SN 1987A argues that core collapse supernovae may be responsible for more that 50 percent of the iron in the galaxy. Furthermore it is argued that the time averaged rate of thermonuclear driven Type I supernovae may be at least an order of magnitude lower than the average rate of core collapse supernovae. The present low rate of Type II supernovae (below their time averaged rate of approx. 1/10 yr) is either because the past rate was much higher because many core collapse supernovae are dim like SN 1987A. However, even in this latter case they are only an order of magnitude dimmer that normal Type II's due to the contribution of Ni-56 decay to the light curve

In-medium vector meson masses in a Chiral SU(3) model

A significant drop of the vector meson masses in nuclear matter is observed in a chiral SU(3) model due to the effects of the baryon Dirac sea. This is taken into account through the summation of baryonic tadpole diagrams in the relativistic Hartree approximation. The appreciable decrease of the in-medium vector meson masses is due to the vacuum polarisation effects from the nucleon sector and is not observed in the mean field approximation.Comment: 26 pages including 10 figures; the text has been modified for clarit

Agriculture spray wind velocity measurements and predictions

During the spraying seasons of 2014 and 2015, wind velocity and solar radiation (2014 only) were collected at a one meter height above the ground to simulate conditions affecting droplets near a ground-based spray boom. This instrumentation was placed in a cross pattern with sensors at the four cardinal directions (north, south, east, and west) with a fifth sensor in the center (2015 only). Data were collected at 10 Hz to measure the turbulent properties of the wind near the ground. Measurements of wind velocity profiles moving from upwind sensors to downwind sensors were used to evaluate correlation between the wind measurements. Two periods in which wind direction, on average, was collinear with multiple sensors were investigated. The first period contained five hours of data in which the average wind speed was 3.6 m/s (8 mi/h), while the second period contained 1.5 hours of data with an average wind speed of 1.5 m/s (3.4 mi/h). For the five hour dataset, correlation coefficients of 0.29 and 0.27 were found for wind direction and wind speed measured at two sensors respectively. This value fell when the five hours were broken up into multiple one minute periods. The correlation coefficients rose from less than 0.03 to greater than 0.14 once a lag term was introduced to the data. These results were not observed in the 1.5 hour dataset. Over the 1.5 hour period, the correlation coefficients were found to be less than 0.03. The introduction of a lag term had no clear effect. The entirety of the datasets that were collected in 2014 and 2015 were investigated to see under what conditions large wind change events were more likely to occur. The datasets suggest that low wind speeds lead to higher probability of large wind changes. As solar radiation increased so did the probability of large changes in wind. As a tolerance on the wind shift was tightened, the probability of wind changes became uniform. In models that predict spray drift, a popular method to simulate turbulent wind conditions in which the droplet is entrained, is to update the current wind velocities with a random process to achieve new wind velocities. This type of process is known as a random walk. The random walk hypothesis was tested using data collected at 10 Hz, and the average of the collected data to simulate data recorded at 0.5 s, 1 s, 5 s, 10 s, 30 s, 1 min, 5 min, and 10 min. For all tests below five minute averages, the test rejected the hypothesis that wind velocity updates can be independent of previous measurements at greater than 95% confidence. Indicating that updates to the current wind velocity is dependent on previous velocities. To help reduce the chances of spray drift, prediction models were developed and tested to predict wind direction 30 seconds into the future utilizing current and past measurements. The models tested included a kernel filter that is used for prediction of wind speeds for wind turbines, an autoregressive process (AR), a full ARIMA process, and a hybrid model that includes ideas from ARIMA and Taylor series expansions. The listed models were tested against a “No Model” model in which the predicted value was simply the current observed value. Models were trained over a one hour dataset and tested over a four hour data set. The AR and hybrid models lowered the RMS error value by 9% over the “No Model” model. The AR and hybrid models were outside of a 20 degree tolerance about 12% of the time. The correlation values between an upwind and downwind sensors indicate that little correlation exists. Along with the predictive models yielding limited results indicate that the wind changes rather randomly. However, results from testing the time series against the random walk hypothesis indicate that wind’s random fluctuations are correlated with one another, but these correlations are not seen using linear correlations. Further effort is needed to better model the wind process

Electron capture to continuum in collisions of bare projectiles with Ne targets

Abstract. We have investigated the cusp resulting from electron capture to the continuum of 1.25-5 MeV m u- ' fully stripped hydrogen and oxygen as a function of the collision energy and the detector angular resolution B o. It is revealed that the characteristic cusp shape parameters depend strongly on the experimental resolution. Our experimental data are "pared with the second-order Born theory and the impulse approximation. Both theories mnhrm the 8, dependence of the shape parameters and gjve a reasonable descrip-lion of the cusp asymmetry. However, theory tends to overestimate the absolute cross sections, in particular in the case of oxygen. 1

Astrophysical and cosmological constraints to neutrino properties

The astrophysical and cosmological constraints on neutrino properties (masses, lifetimes, numbers of flavors, etc.) are reviewed. The freeze out of neutrinos in the early Universe are discussed and then the cosmological limits on masses for stable neutrinos are derived. The freeze out argument coupled with observational limits is then used to constrain decaying neutrinos as well. The limits to neutrino properties which follow from SN1987A are then reviewed. The constraint from the big bang nucleosynthesis on the number of neutrino flavors is also considered. Astrophysical constraints on neutrino-mixing as well as future observations of relevance to neutrino physics are briefly discussed