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A series of minor moraine ridges lying on a lodgement till surface in front of the glacier Austre Okstindbreen are described. The available chronological control suggests that from 1957 through to 1970 a new ridge was formed each winter and that this pattern of annual production is probably also applicable to the period back to circa 1950. During the winter months of 1970/71 and 1971/72 the glacier advanced and deformed the ice cover of a marginal lake which now isolates the till areas from the ice margin. It is concluded that the ridges are true “annual” moraines formed primarily by ice push although the operation of a squeeze process during their genesis is not rejected.
A near infrared heating method is presented which directly heats metal substrates to very high temperatures within seconds. The technique is used to heat 1mm thick titanium and stainless steel metal coupons onto which 1 cm2 commercial TiO2 pastes have been deposited within 12-25 seconds giving assembled dye sensitized solar cell efficiencies which are equivalent to cells prepared using a convection oven for 1800 seconds. The near infrared method is applicable to different paste thicknesses and paste types as well as different metal substrates. Near infrared sintering for the shortest times 12.5 seconds yielded cells with the highest efficiency compared to convection oven prepared samples. This ultrafast heating seems to drive off binder very effectively and lead to rapid sintering. Ultrafast sintering allows peak metal temperatures of 500-800 °C to be achieved without the massive losses in cell efficiency observed with the conventional heat treatment at temperatures over 600 ◦C.
In this report, we describe recent efforts in fabricating new nanocarbon-supported titanium dioxide structures that exhibit high surface area and improved electrical conductivity. Nanocarbons consisting of single-walled carbon nanotubes and carbon aerogel nanoparticles were used to support titanium dioxide particles and produce monoliths with densities as low as 80 mg/cm 3. The electrical conductivity of the nanocarbon-supported titanium dioxide was dictated by the conductivity of the nanocarbon support while the pore structure was dominated by the titanium dioxide aerogel particles. The conductivity of the monoliths presented here was 72 S/m and the surface area was 203 m2/g.
A nitric acid (2M) pre-treatment is shown to increase the efficiency of a standard dye sensitized solar cell mounted on a FTO glass substrate from 4.15% to 5.12%. The pre-treatment involves immersing an FTO glass electrode coated with commercial ethyl cellulose based TiO2 paste for 1-60 minutes prior to sintering at 450°C. The pre-treatment leads to agglomeration of the TiO2 creating a scattering layer which covers the acid treated surface on short term immersion (<30 mins) and penetrates the bulk layer upon long immersion. The scattering layer itself takes up less of the sensitizing (N719) dye but scatters photons in the rest of the film. The optimum immersion time under room temperature conditions was found to be ca 20 minutes since at much longer immersion times the bulk film particle agglomeration reduced efficiency. The choice of anion in the acid is critical with certain species, notably phosphate, resulting in blockage of dye absorption sites in the entire film resulting in reduced cell efficiency.