Is Homeownership the Answer? Housing Tenure and Indigenous Australians in Remote (and Settled) Areas

This paper examines the relevance of recently floated policy ideas for extending homeownership to remote Aboriginal Australians. It argues that while the housing tenure system in more densely settled Australia is dominated by homeownership, this is not, and cannot realistically be expected to be, the case in remote areas. The paper uses data from the 2001 Census, organized by remoteness geography, to demonstrate the different character of the housing tenure system in remote Australia. The paper argues that homeownership in remote Aboriginal communities is a somewhat unrealistic policy goal, given the underlying income and employment status of Indigenous people in these communities. The paper also argues that there are better measures of Indigenous housing need and disadvantage in Australia than low homeownership rates. It briefly reports on one past failed experiment in Queensland to introduce homeownership to a remote Aboriginal community.     

Who lives downtown? Neighbourhood change in central Halifax, 1951–2011

The paper traces neighbourhood change in central Halifax, Canada, from 1951 to 2011 to consider how urban renewal policies and other factors may have influenced who lives downtown. In the 1950s planners advocated slum clearance and modernization to permit commercial expansion in the city centre. Subsequent decades saw central neighbourhoods decline. By the 1980s population began to rebound as planning policy increasingly promoted residential uses downtown. Over the 60 years central Halifax transitioned in character: three of the central tracts became increasingly affluent, while the fourth went from close to the city average to a low-income tract. The trajectories that neighbourhoods follow depend on several factors including societal changes, economic conditions, public policy interventions, and decisions made by other significant institutions (such as universities).     

Porous ceramic bone scaffolds for vascularized bone tissue regeneration

Hydroxyapatite scaffolds with a multi modal porosity designed for use in tissue engineering of vascularized bone graft substitutes were prepared by three dimensional printing. Depending on the ratio of coarse (mean particle size 50 microm) to fine powder (mean particle size 4 microm) in the powder granulate and the sintering temperature total porosity was varied from 30% to 64%. While macroscopic pore channels with a diameter of 1 mm were created by CAD design, porosity structure in the sintered solid phase was governed by the granulate structure of the printing powder. Scaffolds sintered at 1,250 degrees C were characterized by a bimodal pore structure with intragranular pores of 0.3-0.4 microm and intergranular pores of 20 microm whereas scaffolds sintered at 1,400 degrees C exhibit a monomodal porosity with a maximum of pore size distribution at 10-20 microm. For in-vivo testing, matrices were implanted subcutaneously in four male Lewis rats. Scaffolds with 50% porosity and an average pore size of approximately 18 microm were successfully transferred to rats and vascularized within 4 weeks.     

Neue Bauteile aus textilbewehrtem Beton

New Components of Textile Reinforced Concrete Based on the results of investigations in the characteristics of the new composite material textile reinforced concrete (TRC) some first applications of TRC have been developed. This article presents some examples that the advantages of TRC lead to an entirely new application potential for concrete as a building material and open up new fields for the application of concrete.     

McLean's Nuggets

The development of a clean, plentiful and low-cost alternative energy source is the holy grail of the 21st century. Ken Yeang looks into his crystal ball and asks whether the future could lie in nanoenergy and the proliferation of numerous personal nanogenerators - attached to buildings, individuals or under bridges. Copyright © 2009 John Wiley & Sons, Ltd.     

A variable pressure method for characterizing nanoparticle surface charge using pore sensors

A novel method using resistive pulse sensors for electrokinetic surface charge measurements of nanoparticles is presented. This method involves recording the particle blockade rate while the pressure applied across a pore sensor is varied. This applied pressure acts in a direction which opposes transport due to the combination of electro-osmosis, electrophoresis, and inherent pressure. The blockade rate reaches a minimum when the velocity of nanoparticles in the vicinity of the pore approaches zero, and the forces on typical nanoparticles are in equilibrium. The pressure applied at this minimum rate can be used to calculate the zeta potential of the nanoparticles. The efficacy of this variable pressure method was demonstrated for a range of carboxylated 200 nm polystyrene nanoparticles with different surface charge densities. Results were of the same order as phase analysis light scattering (PALS) measurements. Unlike PALS results, the sequence of increasing zeta potential for different particle types agreed with conductometric titration.     

Laser photo-reflectance characterization of resonant nonlinear electro-refraction in thin semiconductor films

Photo-reflectance (PR) measurements provide a non-contact means for the precise characterization of semiconductor electronic properties. In this paper, we investigate the use of a laser beam as the probe beam in the PR setup. In this case it is seen that the nonlinear refraction is responsible for the amplitude change of the reflected probe field, whereas the phase change is due to nonlinear absorption. The open aperture condition may then be used to eliminate the spatial phase at the detector, thereby isolating the electro-refractive contribution to the PR signal. This greatly simplifies the PR analysis and allows absolute measurements of electro-refraction in thin semiconductor films. We report the application of the laser PR technique to characterize physical strain in thin silicon on silicon-germanium films.     

A multi-objective particle swarm optimisation for filter-based feature selection in classification problems

Feature selection has the two main objectives of minimising the classification error rate and the number of features. Based on binary particle swarm optimisation (BPSO), we develop two novel multi-objective feature selection frameworks for classification, which are multi-objective binary PSO using the idea of non-dominated sorting (NSBPSO) and multi-objective binary PSO using the ideas of crowding, mutation and dominance (CMDBPSO). Four multi-objective feature selection methods are then developed by applying mutual information and entropy as two different filter evaluation criteria in each of the proposed frameworks. The proposed algorithms are examined and compared with a single objective method on eight benchmark data sets. Experimental results show that the proposed multi-objective algorithms can evolve a set of solutions that use a smaller number of features and achieve better classification performance than using all features. In most cases, NSBPSO achieves better results than the single objective algorithm and CMDBPSO outperforms all other methods mentioned above. This work represents the first study on multi-objective BPSO for filter-based feature selection.     

Exergy analysis of an isothermal heat pump dryer

A numerical simulation of a plate contact-type isothermal heat pump dryer (HPD) is used to examine the energy efficiency improvement obtainable from this system compared with a conventional HPD. While we consider this system design to be entirely feasible, we are not aware of any existing practical applications of the design. The simulation incorporates a detailed plate, product and air flow model, solving the mass, momentum and energy balances within the drier, into a pre-existing model of the remaining HPD components. The accuracy of an idealised drier-duct model used in a previous analysis is assessed. Although the accuracy of the idealised model is found to be sensitive to local system temperature variations, this is found not to lead to significant error when it is integrated into the whole-system HPD model. The energy efficiency benefit associated with the isothermal contact HPD is confirmed to be a factor of between 2 and 3. An exergy analysis is used to determine the causes of this perfomance gain. Contact heat transfer in isothermal HPD is found to reduce irreversibility within the refrigerant cycle by roughly the same amount as that occurring in heat transfer from the condenser to the product.