Flux-assisted self-assembly of monodisperse colloids

We have developed a novel method to grow ordered layers of monodisperse colloids on a flat substrate. The evaporation of the colloidal suspension in the presence of the inclined substrate is strengthened by an external gas flux directed on the meniscus. The meniscus oscillations caused by the gas flux have an evident effect on the ordering of the spheres on the substrate. Thick films (more than 150 layers in a single-step deposition) of large area single crystals (1 cm2) can be obtained in a very short time (~1 cm/h maximum growth rate) and from very diluted suspensions (up to 0.022% volume fraction).

Inverse opal structure of SnO2 and SnO2 : Zn for gas sensing

In the present work, we propose a low cost synthetic sol-gel route that allows to produce high quality oxide nanostructures with inverse opal architecture which, transferred on alumina substrates provided with Pt interdigitated contacts and heater, are tested as gas sensing devices. An opal template of sintered monodisperse polystyrene spheres was filled with alcoholic solutions of metal oxide precursors and transferred on the alumina substrate. The polystyrene template was removed by thermal treatment, leading to the simultaneous sintering of the oxide nanoparticles. Beside SnO₂, a binary oxide well known for gas sensing application, a Zn containing ternary solid solution (SnO₂:Zn, with Zn 10% molar content) was taken into account for sensor preparation. The obtained high quality macro and meso-porous structures, characterized by different techniques, were tested for pollutant (CO, NO₂) and interfering (methanol) gases, showing that very good detection can be reached through the increase of surface area offered by the inverse opal structure and the tailoring of the chemical composition. The electrical characterization performed on the tin dioxide based sensors shows an enhancement of the relative response towards NO₂ at low temperatures in comparison with conventional SnO₂ sensors obtained with sputtering technique. The addition of Zn increases the separation between the operating temperatures for reducing and oxidizing gases and results in a further enhancement of the selectivity to NO₂ detection.

Reinvigorating the public sphere : the role of voluntary associations

This thesis examines the key question: can voluntary associations enhance democracy? It tests critical claims made by Habermas and others that voluntary associations have the potential to reinvigorate a public sphere in a state of atrophy. The thesis outlines the major theoretical arguments pertaining to these areas and then presents the results of empirical work within voluntary organisations. Specifically the thesis: Critically examines the concept of the public sphere, being a sphere between the state and civil society and investigates why theorists have advocated voluntary associations, claimed to be the core institutions of civil society, as sites where democratic ideals can be secured; Goes on to examine the concept of civil society and reviews the recent literature that has attempted to define and analyse the role of voluntary associations in contemporary society; Tests empirically the normative ideals that have been advocated on behalf of voluntary associations through the presentation of data obtained using qualitative methodology. The analysis of the data collected during interviews with key employees and members of six voluntary associations in Melbourne, Australia allows for a more informed knowledge regarding the key concepts and themes of the thesis. The thesis ends by directly addressing the following points: whether or not the public sphere is in a state of atrophy; the particular nature of voluntary associations contemporary engagement in the public sphere; and whether voluntary associations can indeed, be sites where democracy can be enhanced and democratic ideals be secured. It is concluded that voluntary associations operate within Habermasian public spheres, counterspheres, and postmodern public spheres and that unitary notions of the public sphere, such as those Habermas proposes, do not adequately explain voluntary associations engagement in the public sphere. Accordingly, it is concluded that voluntary associations have the potential to invigorate public spheres, though not in ways that many theorists writing on the subject suggest.

Studies of hypervalent organotin complexes and organotin clusters

(119)Sn, (31)P and (13)C variable temperature NMR spectroscopies have been used to examine the effective coordination spheres in solution of a series of hypervalent organotin(IV) dithiolate compounds RnSnXm(S-S)4-n-m where R = Ph, Me, nBu, tBu; X = Cl, Br; (S-S) = S2CNR'2, S2COR', S2P(OR')2 (R' = Me, Et, iPr) and n = 1, 2, 3; m = 0,1,2. Stereochemical nonrigidity is a common phenomenon found for these hypervalent compounds. On the basis of heteronuclear NMR data and X-ray crystallographic data, dynamic behaviors of these hypervalent compounds have been established. The system of hypervalent organotin(IV) fluoride complexes has also been investigated by variable temperature heteronuclear NMR techniques. A series of monomeric pentacoordinate complexes [RnSnC1mF5-n-m]-(R = Ph, Me, nBu, tBu; n = 2, 3; m - 0, 1, 2, 3) and dimeric complexes [(Me3SnX)F(Me3SnX')]- (X = F, Cl; X' = F, Cl) and hexacoordinate complexes [RnSnClmF6-n.m]2- (R = Ph, Me, nBu; n = 1, 2; m = (X 1, 2, 3,4) are identified in solution. The fluoride is of higer affinite to tin than the chloride. The stereochemistry and dynamic behavior of these complexes in solution has been studied. Fluoride ion may induce phenyl group disproportionation of phenyhin(IV) compounds. It is also found that in pentacoordinate diorganotin complexes, such as [Ph2SnCl2F]- and [Ph2SnClF2]- fluorine can be less apicophilic than chlorine. Studies of stereochemistry and dynamic behavior of bi-functional Lewis acid bis(haloorganosiannes) have also been carried out. The bis(haloorganostannes) exhibit strong chelate ability towards halide, with high selectivity on fluoride, forming heterocyclic chelating rings, the stability of which depend on the ring size. In further exploration of the Lewis acidity of organotin(IV) halides, complexation of organotin(IV) halides with bis(tertiary phosphinc) ligands has been studied by 119Sn and 31P NMR spectroscopy and X-ray crystallography. The phenyl group disproportionation is often observed in the complexation reaction. Furthermore, organotin(IV) clusters such as [(RSn)12O14(OH)6]Cl2-2H2O (R = iPr, nBu) have been successfully prepared by base hydrolysis of RSnCl3. These clusters contain 12 tin atoms in one molecule and the cores of the clusters are dications. Other organotin clusters such as [nBuSn(O)O2CCH3]6 and [(nBuSn(OH)O2PPh2)3][O2PPh2) are readily formed by reaction of the 12-tin-atom cluster with an appropriate acid. The reactivity of and interconversion between organotin(FV) clusters have also been studied.

Leading lights : the promotion of garden suburb plans and planners in interwar Australia

This thesis explores interwar town planning in Australia, focusing on the period of large-scale urban expansion in the 1920’s. It problematises aspects of Australia’s urban planning history, particularly the 1920s ‘garden suburb. It also investigates the question of the use of international planning ideas in Australia, and the assertion or creation of authority by the Australian planning movement. The thesis additionally investigates the use of authoritative planning rhetoric for commercial or creative advantage. The thesis argues that the majority of innovative planning projects in the interwar years took place in the formation and foundation of the garden suburb. It shows that the garden suburb – assumed in much planning history to be an inferior form of Ebenezer Howard’s ‘garden city’ ideal – has, in fact, a number of precedents in 19th century Australian suburbia, some of which were retained in 20th century commercial estate design. Much of the Australian town planner’s authority at this time required recognition and awareness of the interests and needs of the general public, as negotiated through land vendors. As Australians looked to the future, and to the US for guidance, they were invited to invest in speculative real estate development modelled on this vision. The thesis concentrates primarily on the lives, careers and work of the British-Australian architect-planner Sir John Sulman; the Chicagoan architect-planners Marion Mahony and Walter Burley Griffin; and the Australian surveyor-planner Saxil Tuxen. These individuals were among the most prominent planners in Australia in the interwar years. All designed Australian garden suburbs, and combined advocacy with practice in private and public spheres. The thesis examines images and personas, both generic and individual, of the planner and the vendor. It shows that the formulation of the garden suburb and design practices, and the incorporation of international elements into Australian planning, are important in the creation of planning practice and forms. It also outlines the way these continue to have significant impact, in diverse and important ways, on both the contemporary built environment and planning history itself.

Reverse microemulsion-mediated synthesis of SiO2-coated ZnO composite nanoparticles : multiple cores with tunable shell thickness

Monodispersed SiO₂-shell/ZnO-core composite nanospheres have been prepared in an oil-in-water microemulsion system. By using cyclohexane as the oil phase and Triton X-100 as the surfactant, composite nanospheres with high core loading levels and tunable shell thickness were obtained. Utilization of PVP capping agent on ZnO allowed the synthesis of composite nanospheres without forming any coreless SiO2 spheres or shell-less ZnO particles. The photoactivity of ZnO nanoparticles was greatly reduced by SiO2-coating, which enables their applications as durable, safe, and nonreactive UV blockers in plastics, coating, and other products.

Superhydrophobic polyimide films with a hierarchical topography : combined replica molding and layer-by-layer assembly

Artificial superhydrophobic surfaces with a hierarchical topography were fabricated by using layer-by-layer assembly of polyelectrolytes and silica nanoparticles on microsphere-patterned polyimide precursor substrates followed with thermal and fluoroalkylsilane treatment. In this special hierarchical topography, micrometer-scale structures were provided by replica molding of polyamic acid using two-dimensional arrays of polystyrene latex spheres as templates, and nanosized silica particles were then assembled on these microspheres to construct finer structures at the nanoscale. Heat treatment was conducted to induce chemical cross-linking between polyelectrolytes and simultaneously convert polyamic acid to polyimide. After surface modification with fluoroalkylsilane, the as-prepared highly hydrophilic surface was endowed with superhydrophobicity due to the bioinspired combination of low surface energy materials and hierarchical surface structures. A superhydrophobic surface with a static water contact angle of 160 degrees and sliding angle of less than 10 degrees was obtained. Notably, the polyimide microspheres were integrated with the substrate and were mechanically stable. In addition, the chemical and mechanical stability of the polyelectrolyte/silica nanoparticle multilayers could be increased by heat-induced cross-linking between polyelectrolytes to form nylon-like films, as well as the formation of interfacial chemical bonds.

Numerical analysis of heat transfer and the optimisation of regenerators

To optimize a regenerator’s structure and its operation parameters and, consequently, to increase the efficiency of heat recovery and to save energy, a computational approach is used to study the unsteady three-dimensional flow and heat transfer. The simulation is performed in two steps. In the first step, the gas flow and heat transfer in a typical sphere-bed unit is simulated to deduce a dimensionless equation of heat transfer between gas and sphere. In the second step, a model is developed to simplify the prototype and to simulate the gas flow and heat transfer in the whole regenerator. The heat exchange process in regenerators and the effects of the regenerator’s structure and operation parameters, such as gas mass flux, reversal time, regenerator height, sphere diameter, and thermophysical properties of the spheres, are studied with the model to determine efficiency of heat recovery.

Scales of policy intervention : problematising high poverty contexts in South Australia.

Education policy intervention for schools in high poverty neighbourhoods has focused on the capacity of local schools to make a difference and on the kinds of co-ordinated human services provision that might support individual families with “high needs”. In this paper I suggest that a more detailed analysis of “the problem” represented in such schools might yield a richer and more integrated policy approach. I use the notion of “scale”, arbitrary and imperfect approximations of spheres of activity, and apply it to a specific context in Adelaide, South Australia, to demonstrate the connections between the local school and factors which impinge on its capacities to make a positive difference. I suggest that the implication of the analysis is a more holistic approach to policy.

Breast cancer : the embodied transfer of uncertainty and risk

The thesis highlights how women reconstruct themselves after mammography, following a positive diagnosis of cancer, and post mastectomy. It juxtaposes women's experiences of breast cancer with doctors' perceptions of their role in treating patients, allowing an understanding of how risk and uncertainty are transferred between the private and public spheres.

A societal knowledge management system : harnessing indigenous wisdom to build sustainable predictors for adaptation to climate change

As the climate changes globally time-honoured climate in a region may change and shift to another region. Consequently, local predictors of climate may no longer apply to the area where they were born, but may be invaluable in new regions where previously reliable predictors have become outmoded This paper is set on the proposition thaI traditional (indigenous) know/edge can be a strategic source in adapting to climate change, in these changing times. The research reported in this paper takes the Societal Knowledge Management approach where knowledge that rests within local communities, is harnessed to inform local communities and scientists regarding climate change impacts, so as to adapt to them accurately. A phased study was conducted that aimed at acquiring, synthesising and disseminating traditional knowledge regarding change in monsoon patterns in India. Traditional wisdom prevalent among fhe myriad communities of India, was collected, collated and classified into knowledge spheres such as Bio-Indicators, Wind Movement, Atmospheric Pal/ems, Astrological Methods, Festivals and Rituals, Direction, Characteristics of the Rain, Characteristics of Celestial Bodies etc and incorporaled into a knowledge portal, which is the basis for building the Societal Knowledge Management System (SKM). Subsequently, the SKM is to be harmonised with scientific predictors on seasonal weather patterns will allow researchers to identify if the existing indicators and monsoon pattems are subject to change, and if so how. Research in progress is aimed at integrating the knowledge with modern science and disseminating this knowledge through local knowledge centres, at village levels. Furthermore, this study is to be replicated in Australia, by harnessing indigenous knowledge, to build the SKM for Australia that could assist in building a better understanding of the factors that impact the environment, methods of building sustainable predictors for climate and approaches for adapting the climate changes. The research reported is expected to inform policy makers, scientists, governance institutions as well as researchers regarding the applicability of indigenous knowledge in building sustainable predictors for adaptation to climate change in the two countries cited and can be extended into other countries.

Indigenous research ethics : new modes of information gathering and storytelling in journalism

Veteran Indigenous affairs reporter Tony Koch emphasises the importance of respect, trust and listening in his journalism practice. This paper draws on Koch’s insights as well as recent scholarship on the policies and value of listening to support the proposal that Indigenous research ethics provide a concrete framework for improving media representations of Indigenous people and their access to news media. The university ethics process cannot replicate the understanding Koch has gained from 25 years of interacting with Indigenous people and their communities. However, this paper argues it provides a pathway along which journalism academics and their students can learn to engage with Indigenous people, navigate Indigenous public spheres and produce high-quality reporting that reflects Indigenous people’s aspirations. Journalists within the academy, who are not subject to the commercial or organizational pressures of the news industry, are especially well placed to collaborate with Indigenous people to deliver new ways of conducting research and telling stories that privilege their perspectives. Koch’s newsgathering practice demonstrates that many principals of this progressive approach are also achievable in mainstream journalism.

Synthesis and growth of hematite nanodiscs through a facile hydrothermal approach

This study reports a facile hydrothermal method for the synthesis of monodispersed hematite (α-Fe2O3) nanodiscs under mild conditions. The method has features such as no use of surfactants, no toxic precursors, and no requirements of high-temperature decomposition of iron precursors in non-polar solvents. By this method, α-Fe2O3 nanodiscs were achieved with diameter of 50 ± 10 nm and thickness of ~6.5 nm by the hydrolysis of ferric chloride. The particle characteristics (e.g., shape, size, and distribution) and functional properties (e.g., magnetic and catalytic properties) were investigated by various advanced techniques, including TEM, AFM, XRD, BET, and SQUID. Such nanodiscs were proved to show unique magnetic properties, i.e., superparamagnetic property at a low temperature (e.g., 20 K) but ferromagnetic property at a room temperature (~300 K). They also exhibit low-temperature (<623 K) catalytic activity in CO oxidation because of extremely clean surfaces due to non-involvement of surfactants, compared with those spheres and ellipsoids capped by PVP molecules.

Implementation of enterprise resource planning (ERP) software in a major construction contracting organization in Hong Kong

Purpose – The purpose of this paper is to summarize the scope, methodology and main findings of a doctoral thesis about the implementation of enterprise resource planning (ERP) software in a major construction contracting organization in Hong Kong. This research is taken from a leadership and power and project management (PM) perspective.

Design/methodology/approach – The project adopted a case study approach in which the candidate was an employee/observer, who was embedded as a member of the business transformation team taking an action learning approach to study the ERP adoption. The research used the soft system methodology to identify gaps in the observed maturity level which exists in the organization. Data was gathered using public and private documentation, semi-structured interviews, observation and was validated through review of evidence with participants.

Findings – The results identified the importance of leadership and cultural issues in implementation of the business strategy. This research includes a contribution in two spheres: PM and construction procurement. The first implication for PM theory was to illustrate how knowledge has been efficiently managed within a construction organization by using information communication technology (ICT). It can be represented by the ladder of ICT>ERP>KM>PM. The second implication was to pave the way for the use of partnering strategies in PM practice. It can be represented by the ladder of National Culture>Organizational Culture>Leadership>Partnering Strategy>PM.

Practical implications – This model could be adapted to other large and complex organisational contexts. The research project also has implications as opening up a PM perspective on business transformation.

Originality/value – The contribution of this research is proving the success of adopting KM in a construction company by using an ERP system. The importance of culture in the traditionally collectivistic construction industry, and the issues senior management should take into account when formulating business strategies.

Major grass pollen allergen Lol p 1 binds to diesel exhaust particles : implications for asthma and air pollution

Background Grass pollen allergens are known to be present in the atmosphere in a range of particle sizes from whole pollen grains (approx. 20 to 55 μim in diameter) to smaller size fractions < 2.5 μ (fine particles, PM2.5). These latter particles are within the respirable range and include allergen-containing starch granules released from within the grains into the atmosphere when grass pollen ruptures in rainfall and are associated with epidemics of thunderstorm asthma during the grass pollen season. The question arises whether grass pollen allergens can interact with other sources of fine particles, particularly those present during episodes of air pollution.

Objective We propose the hypothesis that free grass pollen allergen molecules, derived from dead or burst grains and dispersed in microdroplets of water in aerosols, can bind to fine particles in polluted air.

Methods We used diesel exhaust carbon particles (DECP) derived from the exhaust of a stationary diesel engine, natural highly purified Lol p 1, immunogold labelling with specific monoclonal antibodies and a high voltage transmission electron -microscopic imaging technique

Results DECP are visualized as small carbon spheres, each 30–60 nm in diameter, forming fractal aggregates about 1–2μ in diameter. Here we test our hypothesis and show by in vitro experiments that the major grass pollen allergen, Lol p I. binds to one defined class of fine particles, DECP.

Conclusion DECP are in the respirable size range, can bind to the major grass pollen allergen Lol p I under in vitro conditions and represent a possible mechanism by which allergens can become concentrated in polluted air and thus trigger attacks of asthma.