Becoming eco-responsible, active citizens through participation in the Eco Ambassadors project - a reflective analysis

This article offers a reflective analysis of the Eco Ambassadors Project as an example of the some of the ways in which learning about environmental issues and active citizenship can be encouraged and enabled through collaboration and negotiated participation. Some policy background to the project is given, followed by a critical consideration of the theoretical framework of situated learning and participation in a community of practice in relation to the project alongside theories of citizenship. Three activities undertaken during the project are highlighted and these are critically examined in relation to the theories under consideration. The paper argues that the theoretical framework of learning by participation can usefully augment and help better explain how learners develop their identities as citizens, and that through participation people can become active members of communities that are environmentally and politically aware

An Evaluation of Techroll Seal Flexible Joint Material

This study evaluated the materials utilized in the flexible joint for possible failure modes. Studies undertaken included effect of temperature on the strength of the system, effect of fatigue on the strength of the system, thermogravimetric analysis, thermochemical analysis, differential scanning calorimeter analysis, dynamic mechanical analysis, and peel test. These studies indicate that if the joint failed due to a materials deficiency, the most likely mode was excessive temperature in the joint. In addition, the joint material is susceptible to fatigue damage which could have been a contributing factor

Structural application of high strength, high temperature ceramics

The operation of rocket engine turbine pumps is limited by the temperature restrictions of metallic components used in the systems. Mechanical strength and stability of these metallic components decrease drastically at elevated temperatures. Ceramic materials that retain high strength at high temperatures appear to be a feasible alternate material for use in the hot end of the turbopumps. This project identified and defined the processing parameters that affected the properties of Si3N4, one of candidate ceramic materials. Apparatus was assembled and put into operation to hot press Si3N4 powders into bulk material for in house evaluation. A work statement was completed to seek outside contract services to design, manufacture, and evaluate Si3N4 components in the service environments that exists in SSME turbopumps

VLT Observations of Two Unusual BAL Quasars

Among the unusual broad absorption line quasars being found by the Sloan Digital Sky Survey (SDSS) are objects with much stronger absorption in Fe III than Fe II. These unusual line ratios require a high density in the outflow (n_H >= 3 x 10^{10} cm^{-3}). They should also appear for only a limited range of outflow column densities, which explains their rarity. Previously we suggested that the Fe III line ratios were also affected by a resonance; we now believe this is an artifact of structure in the underlying Fe II + Fe III pseudocontinuum. The SDSS is also discovering objects with absorption in rarely seen transitions such as He I. VLT+UVES high-resolution spectra of one such object, the mini-BAL quasar SDSS 1453+0029, show that it has two He I absorption systems with considerably different properties separated by only 350 km/s.Comment: 4 pages, 3 figures; to appear in "Active Galactic Nuclei, from Central Engine to Host Galaxy", eds. Collin, Combes & Shlosman, PASP Conference Series, in pres

The use of perfluoroether lubricants in unprotected space environments

A series of ball bearing tests in simulated space environment are described which determine durability of perfluoroether lubricants. The results of the examination of the test bearings for each stage are described and experimental techniques designed to overcome lubricant degradation are outlined

Electrical contacts to cadmium sulfide single crystals Technical report no. 2

Multilayer metal deposition technique to provide electrical contacts for cadmium sulfide single crystal

Lunar construction research

Research on lunar base design and constructio

An extension to GUM methodology: degrees-of-freedom calculations for correlated multidimensional estimates

The Guide to the Expression of Uncertainty in Measurement advocates the use of an 'effective number of degrees of freedom' for the calculation of an interval of measurement uncertainty. However, it does not describe how this number is to be calculated when (i) the measurand is a vector quantity or (ii) when the errors in the estimates of the quantities defining the measurand (the 'input quantities') are not incurred independently. An appropriate analysis for a vector-valued measurand has been described (Metrologia 39 (2002) 361-9), and a method for a one-dimensional measurand with dependent errors has also been given (Metrologia 44 (2007) 340-9). This paper builds on those analyses to present a method for the situation where the problem is multidimensional and involves correlated errors. The result is an explicit general procedure that reduces to simpler procedures where appropriate. The example studied is from the field of radio-frequency metrology, where measured quantities are often complex-valued and can be regarded as vectors of two elements.Comment: 30 pages with 2 embedded figure