Developing generative themes for community action

This chapter explores a range of participative methods for working with groups to achieve social change in community settings. It draws on the work of Paulo Freire and examines how workers can facilitate processes of dialogue and critical reflection which enable local people to develop solutions to the issues they are dealing with

Stress corrosion cracking of titanium alloys - Potential transients at open circuit during SCC and pitting corrosion, and chloride absorption during formation of TiO sub 2 Quarterly progress report, Jul. 1 - 30 Sep. 1967

Stress corrosion cracking of titanium alloys and chloride absorption during formation of titanium oxid

Stress corrosion cracking of titanium alloys heat treatment effects, SCC velocity in various solvents and electrochemical kinetics with Ti - 8-1-1 alloy Quarterly progress report, 1 Oct. - 31 Dec. 1966

Stress corrosion cracking of titanium alloy

Stress corrosion crack inhibiting method for titanium

Addition of oxyanions to liquid solvents in excess of the number of chloride, bromide, or iodide ions present prevents cracking of titanium-aluminum alloys under exposure to aqueous and other solvent environments. The molar concentration of oxyanion is set from 10 to 100 times higher than concentration of halide ions

Can spicules be detected at disc centre in broad-band Ca II H filter imaging data ?

We estimate the formation height range contributing to broad-band and narrow-band filter imaging data in Ca II H to investigate whether spicules can be detected in such observations at the centre of the solar disc. We apply spectral filters of FWHMs from 0.03 nm to 1 nm to observed Ca line profiles to simulate Ca imaging data. We estimate the relative intensity contributions of off-limb and on-disc structures. We compare the synthetic Ca filter imaging data with intensity maps of Ca spectra at different wavelengths and temperature maps at different optical depths. We determine the intensity response function for the wavelengths covered by the filters of different FWHM. The intensity emitted off the solar limb is about 5% of the intensity at disc centre. For a 0.3 nm-wide Ca II H filter, up to about 1/3 of the off-limb intensity comes from emission in Hepsilon. On the disc, only about 15% of the intensity transmitted through a broad-band filter comes from the line-core region. No traces of elongated fibrillar structures are visible in imaging data at disc centre, opposite to the line-core images of the Ca spectra. The response function for a 0.3 nm-wide filter peaks at about 200 km. Relative contributions from atmospheric layers above 800 km are about 10%. The inversion results suggest that the slightly enhanced emission around the photospheric magnetic network in broad-band Ca imaging data is caused by a thermal canopy at a height of about 600 km. Broad-band Ca II H imaging data do not trace upper chromospheric structures such as spicules in observations at the solar disc because of the too small relative contribution of the line core to the total wavelength-integrated filter intensity.Comment: 10 pages, 11 figures, accepted for publication in A&