Electrochemical Investigation of Corrosion in the Space Shuttle Launch Environment

Corrosion studies began at NASA/Kennedy Space Center in 1966 during the Gemini/Apollo Programs with the evaluation of long-term protective coatings for the atmospheric protection of carbon steel. An outdoor exposure facility on the beach near the launch pad was established for this purpose at that time. The site has provided over 35 years of technical information on the evaluation of the long-term corrosion performance of many materials and coatings as well as on maintenance procedures. Results from these evaluations have helped NASA find new materials and processes that increase the safety and reliability of our flight hardware, launch structures, and ground support equipment. The launch environment at the Kennedy Space Center (KSC) is extremely corrosive due to the combination of ocean salt spray, heat, humidity, and sunlight. With the introduction of the Space Shuttle in 1981, the already highly corrosive conditions at the launch pad were rendered even more severe by the acidic exhaust from the solid rocket boosters. It has been estimated that 70 tons of hydrochloric acid (HC1) are produced during a launch. The Corrosion Laboratory at NASA/KSC was established in 1985 to conduct electrochemical studies of corrosion on materials and coatings under conditions similar to those encountered at the launch pads. I will present highlights of some of these investigations

Drying of Large Cylindrical Bales with a Solar Energy Intensifier-thermal Energy Storage System

Recent energy conditions have caused a reexamination of the use of solar energy for the drying of agricultural crops. As a result, because of the great importance in developing alternate energy sources as substitutes for conventional energy sources, research was conducted with the following objectives: 1. Test a multi-use solar energy intensifier-thermal energy storage system using various drying systems for a low temperature hay drying application. 2. Evaluate the thermal efficiency in terms of useful energy collected for a solar energy intensifier used to provide supplemental heat to dry hay, under actual climatic conditions

Low energy universality and scaling of Van der Waals forces

At long distances interactions between neutral ground state atoms can be described by the Van der Waals potential V(r) =-C6/r^6-C8/r^8 - ... . In the ultra-cold regime atom-atom scattering is dominated by s-waves phase shifts given by an effective range expansion p cot d0 (p) = -1/a0 + r0 p^2/2 + ... in terms of the scattering length a0 and the effective range r0. We show that while for these potentials the scattering length cannot be predicted, the effective range is given by the universal low energy theorem r0 = A + B/a0+ C/a0^2 where A,B and C depend on the dispersion coefficients Cn and the reduced di-atom mass. We confront this formula to about a hundred determinations of r0 and a0 and show why the result is dominated by the leading dispersion coefficient C6. Universality and scaling extends much beyond naive dimensional analysis estimates.Comment: 4 pages, 3 figure

Corrosion Protection of Launch Infrastructure and Hardware Through the Space Shuttle Program

Corrosion, the environmentally induced degradation of materials, has been a challenging and costly problem that has affected NASA's launch operations since the inception of the Space Program. Corrosion studies began at NASA's Kennedy Space Center (KSC) in 1966 during the Gemini/Apollo Programs with the evaluation of long-term protective coatings for the atmospheric protection of carbon steel. NASA's KSC Beachside Corrosion Test Site, which has been documented by the American Society of Materials (ASM) as one of the most corrosive, naturally occurring environments in the world, was established at that time. With the introduction of the Space Shuttle in 1981, the already highly corrosive natural conditions at the launch pad were rendered even more severe by the acidic exhaust from the solid rocket boosters. In the years that followed, numerous efforts at KSC identified materials, coatings, and maintenance procedures for launch hardware and equipment exposed to the highly corrosiye environment at the launch pads. Knowledge on materials degradation, obtained by facing the highly corrosive conditions of the Space Shuttle launch environment, as well as limitations imposed by the environmental impact of corrosion control, have led researchers at NASA's Corrosion Technology Laboratory to establish a new technology development capability in the area of corrosion prevention, detection, and mitigation at KSC that is included as one of the "highest priority" technologies identified by NASA's integrated technology roadmap. A historical perspective highlighting the challenges encountered in protecting launch infrastructure and hardware from corrosion during the life of the Space Shuttle program and the new technological advances that have resulted from facing the unique and highly corrosive conditions of the Space Shuttle launch environment will be presented

Conditional cash transfers in education : design features, peer and sibling effects evidence from a randomized experiment in Colombia

This paper presents an evaluation of multiple variants of a commonly used intervention to boost education in developing countries - the conditional cash transfer - with a student level randomization that allows the authors to generate intra-family and peer-network variation. The analysis tests three treatments: a basic conditional cash transfer treatment based on school attendance, a savings treatment that postpones a bulk of the cash transfer due to good attendance to just before children have to re-enroll, and a tertiary treatment where some of the transfers are conditional on students'graduation and tertiary enrollment rather than attendance. On average, the combined incentives increase attendance, pass rates, enrollment, graduation rates, and matriculation to tertiary institutions. Changing the timing of the payments does not change attendance rates relative to the basic treatment but does significantly increase enrollment rates at both the secondary and tertiary levels. Incentives for graduation and matriculation are particularly effective, increasing attendance and enrollment at secondary and tertiary levels more than the basic treatment. There is some evidence that the subsidies can cause a reallocation of responsibilities within the household. Siblings (particularly sisters) of treated students work more and attend school less than students in families that received no treatment. In addition, indirect peer influences are relatively strong in attendance decisions with the average magnitude similar to that of the direct effect.Tertiary Education,Access to Finance,Primary Education,Secondary Education,Economics of Education