Kitchen skylight, C House, Coorparoo, Brisbane

Frameless toughened glass skylight to kitchen, supported by timber joists. Outdoor room on right, Iwan roof beyond.

Kitchen skylight, C House, Coorparoo, Brisbane

Frameless toughened glass skylight to kitchen, supported by timber joists. Outdoor room on right, Iwan roof beyond.

Street elevation, Q House, Chelmer, Brisbane

View to house from street. Existing house gable roof on right.

Trusses, Hill House, Chapel Hill, Brisbane

Trusses to living room roof.

Sketch design drawing, Hill House, Chapel Hill, Brisbane

Three-dimensional projection sketch showing roof forms and wall finishes.

High selectivity microporous silica membranes for lactic acid dehydration

Lactic acid (LA) has significant market potential for many industries including food, cosmetics, pharmaceuticals, medical and biodegradable materials. Production of LA usually begins with the fermentation of glucose but subsequent stages for the enrichment of lactic acid are complex and energy intensive and could be minimised using water selective membrane technology. In this work, we trialled a highly selective hydrostable carbonised template molecular sieve silica (CTMSS) membrane for the dehydration of a 15 vol% aqueous lactic acid solution with 0.1 vol% glucose. CTMSS membrane films were developed by dip-coating ceramic substrates with silica sols made using the acid catalysed sol-gel process. Permeation was performed by feeding LA/glucose solution to the membrane cell at 18°C in a standard pervaporation setup. The membrane showed selective transport of water from the aqueous feed to the permeate while glucose was not detected. CTMSS membrane permeate flux stabilised at 0.2 kg.m-2.hr-1 in 3.9 hours, and reduced LA to lower than 0.2 vol%. Flux through the CTMSS micropores was activated, displaying increased initial flux to 1.58 kg.m-2.hr-1 at 60°C. To enrich a 1 l.min-1 stream to 85% LA in a single stage, a minimum membrane area of 324 m2 would be required at 18°C. Increased operating temperature to 80°C significantly reduced this area to 24 m2 but LA levels in the permeate stream increased to 0.5 vol%. The highly selective CTMSS membrane technology is an ideal candidate for LA purification. CTMSS membrane systems operate stably in aqueous systems leading to potential cost reductions in LA processing for future markets.

Outdoor room, Kangaroo Point House, Kangaroo Point, Brisbane

Dining setting, sculptures, timber columns and curved roof in outdoor room

Bath house pavilion, Lake Weyba House, Sunshine Coast

Link to bedroom pavilion on right; roof of main pavilion on left.

South elevation, Prasser House, Buderim

As seen from adjacent property (roof irrigation system in use).

Ceiling interior, Raun Raun Theatre, Goroka

View to underside of thatched roof with king post and bracing.

Agriculture and Entomology Building, Brisbane

View to north and east facing wings, along circulation path to the roof feature connection between wings.

Entrance deck, Mooloomba House, Point Lookout, North Stradbroke Island

View past kitchen windows and roof overhang to entrance deck to the south-west.

Part of south-east elevation, Sunshine Coast University Library, Maroochydore

View to part of south-east elevation with skillion roof, corrugated steel sheeting and concrete block.

Timber-framed windows, Powell House, Noosa River, Sunshine Coast

Folding timber windows and roof over.

Oxidation mechanism of Si3N4-bonded SiC ceramics by CO, CO2 and steam

This paper presents a theoretical and experimental investigation into the oxidation reactions of Si3N4-bonded SiC ceramics. Such ceramics which contain a small amount of silicon offer increased oxidation and wear resistance and are widely used as lining refractories in blast furnaces. The thermodynamics of oxidation reactions were studied using the JANAF tables. The weight gain was measured using a thermogravimetric analysis technique to study the kinetics. The temperature range of oxidation measurements is from 1073 to 1573 K and the oxidation atmosphere is water vapour, pure CO and CO-CO2 gas mixtures with various CO-to-CO2 ratios. Thermodynamic simulations showed that the oxidation mechanism of Si3N4-bonded SiC ceramics is passive oxidation and all components contribute to the formation of a silica film. The activated energies of the reactions follow the sequence Si3N4>SiC>Si. The kinetic study revealed that the oxidation of Si3N4-bonded SiC ceramics occurred in a mixed regime controlled by both interface reaction and diffusion through the silica film. Under the atmosphere conditions prevailing in the blast furnace, this ceramic is predicted to be passively oxidized with the chemical reaction rate becoming more dominant as the CO concentration increases. (C) 1998 Chapman & Hall.