Detailed analysis of radiation data from the Gemini 4 and Gemini 7 proton-electron spectrometer experiments Final report, 13 Jun. 1967 - 30 Dec. 1968

Detailed analysis of radiation data from Gemini 4 and 7 proton-electron spectrometer experiment

The effects of the geosynchronous energetic particle radiation environment on spacecraft charging phenomena

The energetic electron environment at the geosynchronous orbit is responsible for a variety of adverse charging effects on spacecraft components. The most serious of these is the degradation and failure of a complementary-metal-oxide-semiconductor (CMOS) electronic components as a result of internal charge-buildup induced by the energetic electrons. Efforts to accurately determine the expected lifetime of these components in this orbit are hampered by the lack of detailed knowledge of the electron spectrum and intensity, particularly of the more penetrating energies greater than 1.5 MeV. This problem is illustrated through the calculation of the dose received by a CMOS device from the energetic electrons and associated bremsstrahlung as a function of aluminum shielding thickness using the NASA AE-6 and the Aerospace measured electron environments. Two computational codes which were found to be in good agreement were used to perform the calculations. For a given shielding thickness the dose received with the two radiation environments differ by as much as a factor of seven with a corresponding variation in lifetime of the CMOS

Access and use of health care services by mothers and children in the Texas-Mexico border region: preliminary findings from the 2006 Rio Grande Valley health survey

Background: Latino/a children have the highest rate of uninsurance among all ethnic/racial groups. There is some evidence that patterns of health care use between parents and their children are interrelated. Children are also more likely to have health insurance coverage if their parents are insured but public insurance programs do not cover all parents of participating children. The objective of this study was to assess whether there is a relation between patterns of health care utilization between Latina mothers and their children who reside in the South Texas- Mexico border region. Survey data on 495 Latina women with children from the 2006 Rio Grande Valley Health Survey were used to estimate bivariate probit models of the determinants of five health care access and utilization indicators. Patterns of health care utilization between Latina mothers and their children were positively related for having a usual place of care, visiting a doctor, visiting an emergency room, and having delayed health care needed. Both desirable and undesirable parental and child health care access/utilization patterns for Latinos/as are interrelated. Interventions that promote good health care utilization behavior for Latina mothers seem to spillover to their children. Public health insurance programs that focus on covering uninsured children but leave their parents uninsured may end up not taking full advantage of the positive spillover effects of health care access/utilization from mothers to their children

Analysis of high resolution satellite data for cosmic gamma ray bursts

Cosmic gamma ray bursts detected a germanium spectrometer on the low altitude satellite 1972-076B were surveyed. Several bursts with durations ranging from approximately 0.032 to 15 seconds were found and are tabulated. The frequency of occurrence/intensity distribution of these events was compared with the S to the -3/2 power curve of confirmed events. The longer duration events fall above the S to the -3/2 power curve of confirmed events, suggesting they are perhaps not all true cosmic gamma-ray bursts. The narrow duration events fall closely on the S to the -3/2 power curve. The survey also revealed several counting rate spikes, with durations comparable to confirmed gamma-ray bursts, which were shown to be of magnetospheric origin. Confirmation that energetic electrons were responsible for these bursts was achieved from analysis of all data from the complete payload of gamma-ray and energetic particle detectors on board the satellite. The analyses also revealed that the narrowness of the spikes was primarily spatial rather than temporal in character

Propensity score matching, a distance-based measure of migration, and the wage growth of young men

This paper estimates the effect of U.S. internal migration on real wage growth between the movers’ first and second jobs. Our analysis of migration differs from previous research in three important aspects. First, we exploit the confidential geocoding in the National Longitudinal Surveys of Youth 1979 (NLSY79) to obtain a distance-based measure. Second, we let the effect of migration on wage growth differ by schooling level. Third, we use propensity score matching to measure the effect of migration on the wages of those who move. We develop an economic model and use it to (i) assess the appropriateness of matching as an econometric method for studying migration and (ii) choose the conditioning variables used in the matching procedure. Our data set provides a rich array of variables on which to match. We find a significant effect of migration on the wage growth of college graduates of 10 percent and a marginally significant effect for high school dropouts of -12 percent. If we use a measure of migration based on moving across either county lines or state lines, the significant effects of migration for college graduates and dropouts disappear

Government review of the Mod-2 wind turbine (as-built)

The findings and recommendations of the Government committee formed to conduct an as-built review of the three Mod-2 wind turbine units at Goldendale, Washington are given. The purpose of the review was to identify any critical deficiencies in machine components that could result in failure, and to recommend any necessary corrective action before resuming safe machine operation. The review concluded that one of the deficiencies identified would preclude planned attended or unattended operation, provided that certain corrective actions were implemented

Evaluation of Photodiode Arrays for Use in Rocket Plume Monitoring and Diagnostics

The spectroscopic analysis of plume emissions is a non-intrusive method which has been used to check for fatigue and possible damage throughout the pumps and other mechanisms in a rocket motor or engine. These components are made of various alloys. Knowing the composition of the alloys and for which parts they are used, one can potentially determine from the emissions in the plume which component is failing. Currently, Optical Multichannel Analyzer systems are being used which utilize charge coupled devices, cost tens of thousands of dollars, are somewhat delicate, and usually require cooling. We have developed two rugged instruments using less expensive linear photodiode arrays as detectors. A high resolution system was used to detect atomic emission lines while a low resolution system was used to detect molecular emission bands. We have also written data acquisition software and built electronic circuits to control the arrays and collect data. While NASA has used similar systems for characterization of the Space Shuttle Main Engine, the emissions from other rocket systems have not been surveyed as well. The two instruments described will be utilized to study hybrid rocket emissions at the UALR hybrid rocket facility

Modeling atmospheric effects of the September 1859 Solar Flare

We have modeled atmospheric effects, especially ozone depletion, due to a solar proton event which probably accompanied the extreme magnetic storm of 1-2 September 1859. We use an inferred proton fluence for this event as estimated from nitrate levels in Greenland ice cores. We present results showing production of odd nitrogen compounds and their impact on ozone. We also compute rainout of nitrate in our model and compare to values from ice core data.Comment: Revised version including improved figures; Accepted for publication in Geophys. Res. Lett, chosen to be highlighted by AG