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

A Balmer-line Broad Absorption Line Quasar

I report the discovery of blueshifted broad absorption line (BAL) troughs in at least six transitions of the Balmer series of hydrogen (Hbeta to H9) and in CaII, MgII and excited FeII in the quasar SDSS J125942.80+121312.6. This is only the fourth active galactic nucleus known to exhibit Balmer absorption, all four in conjunction with low-ionization BAL systems containing excited Fe II. The substantial population in the n=2 shell of H I in this quasar's absorber likely arises from Ly-alpha trapping. In an absorber sufficiently optically thick to show Balmer absorption, soft X-rays from the quasar penetrate to large \tau_Ly\alpha and ionize H I. Recombination then creates Ly-alpha photons that increase the n=2 population by a factor \tau_Ly\alpha since they require about \tau_Ly\alpha scatterings to diffuse out of the absorber. Observing Ly-alpha trapping in a quasar absorber requires a large but Compton-thin column of gas along our line of sight which includes substantial H I but not too much dust. Presumably the rarity of Balmer-line BAL troughs reflects the rarity of such conditions in quasar absorbers.Comment: AJ in press. 4 pages, 1 figure, 1 table, emulateapj forma

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