Darwin after dark: illuminating suburban atmospheres

In Australian cities, culturally diverse suburban landscapes are often sensed as discomforting sites of fear and anxiety, particularly after dark. Imagined risks of encounters with bodies of colour easily policed during the day when vision is clear, but who escape biopolitical regimes of securitisation and surveillance at night contribute to such atmospheric qualities of place. These affective atmospheres of fear and anxiety that haunt bodies and limit their ability to inhabit public space, however, can provide a sense of freedom for bodies who claim suburban spaces of darkness through tactile and sonic senses. This paper draws on the contemporary literature on affective atmospheres to show how racialised Indigenous and asylum seeker bodies become present in different ways in suburban places in Darwin after dark. The paper focuses on two events – spontaneous dancing to Indigenous music at Mindil beach market and a Vigil commemorating asylum seeker lives in a suburban courtyard. Drawing on ethnographic research I explore these affective intervention that illuminate dark suburban atmospheres in Darwin. Such interventions that draw attention to the attunement of bodies to difference unsettle biopolitical regimes that victimise and patronise visible non-white bodies and contribute to rethinking racism and darkness in suburban Darwin and the Top End.

Postcolonial atmospheres: recalling our shadow places

The book contains thought-provoking discussions on regional Australia's colonial and cultural heritage, and details innovative new methods for measuring cultural assets, as well as reflecting on fostering collaborations with peak cultural ...

Fluidized bed CrN coating formation on prenitrocarburized plain carbon steel

CrN coatings were formed on plain carbon steel by prenitrocarburizing, followed by thermoreactive deposition and diffusion (TRD) in a fluidized bed furnace at 570 °C. During TRD, Cr was transferred from Cr powder in the fluidized bed to the nitrocarburized substrates by gas-phase reactions initiated by reaction of HCl gas with the Cr. The microstructural processes occurring in the white layer, caused by N diffusion toward the surface during this stage were studied. This study compares TRD atmospheres employing inert gas and HCl or inert gas, H2, and HCl. Surface characterization was performed by scanning electron microscopy (SEM), x-ray diffraction (XRD), and glow-discharge optical-emission spectroscopy (GDOES).

Effect of heat-treatment atmosphere on the bond strength of apatite layer on Ti substrate

Objectives
The purpose of this study was to investigate the bond strength of apatite layer on titanium (Ti) substrate coated by biomimetic method and to improve the bonding of apatite layer to Ti substrate by optimizing the alkali heat-treatment process.

Methods
Ti plates pre-treated with an alkali solution of 10 M sodium hydroxide (NaOH) were heat-treated at 600 °C for 1 h at different atmospheres: in air and in vacuum. A dense apatite layer formed on top of the sodium titanate layer after soaking the alkali and heat-treated Ti samples in simulated body fluid (SBF) for up to 3 weeks. The bond strengths of the sodium titanate layer on Ti substrate, and apatite layer on the sodium titanate layer, were measured, respectively, by applying a tensile load. The fracture sites were observed with a scanning electron microscope (SEM).

Results
The apatite layer on the substrate after alkali heat-treatment in air achieved higher bond strength than that on the substrate after alkali heat-treatment in vacuum. It was found that the interfacial structure between the sodium titanate and Ti substrate has a significant influence on the bond strength of the apatite layer.

Significance
It is advised that titanium implants can achieve better osseointegration under load-bearing conditions by depositing an apatite layer in vivo on a Ti surface subjected to alkali and heat-treated in air.

Understanding the behavior of advanced high-strength steels using atom probe tomography

The key evidence for understanding the mechanical behavior of advanced high strength steels was provided by atom probe tomography (APT). Chemical overstabilization of retained austenite (RA) leading to the limited transformation-induced plasticity (TRIP) effect was deemed to be the main factor responsible for the low ductility of nanostructured bainitic steel. Appearance of the yield point on the stress-strain curve of prestrained and bake-hardened transformationinduced plasticity steel is due to the unlocking from weak carbon atmospheres of newly formed during prestraining dislocations.

Atom probe tomography as a tool to advance steels design and performance

Development of modern steels consisting of complex or nano-scale microstructures with advanced properties requires in-depth understanding of the mechanisms responsible for their microstructure/property relationships. The evolution of microstructure during processing is often associated with various changes taking place at atomic level. These include solute distribution between phases as a result of phase transformations, formation of atmospheres at dislocations, clustering and precipitation phenomena due to various thermo-mechanical processing schedules and/or heat treatments. Atom probe tomography (APT) is invaluable tool for gaining insight into events at atomic scale determining the steel properties. This technique also contributes to the fundamental understanding of phase transformations, which is essential for nano-scale engineering of modern steels and optimization of their performance. In this work application of APT to study solute segregation, clustering and precipitation in TRIP steels and nanostructured bainitic steels after isothermal heat-treatment and after thermomechanical processing will be discussed.

On the low temperature strain aging of bainite in the TRIP steel

The aging behavior of a thermomechanically processed Mo-Al-Nb transformation-induced plasticity steel with ultrafine microstructure was investigated using transmission electron microscopy and atom probe tomography (APT). Strain aging at 73 K (200 °C) for 1800 seconds led to a significant bake-hardening response (up to 222 MPa). Moreover, aging for 1800 seconds at room temperature after 4 pct pre-strain also revealed a bake-hardening response (~60 MPa). The experimental results showed the formation of carbon Cottrell atmospheres around dislocations and the formation of carbon clusters/fine carbides in the bainitic ferrite during aging. It is proposed that this is associated with the high dislocation density of bainitic ferrite with formation of a complex dislocation substructure after pre-straining and its high average carbon content (~0.35 at. pct). The segregation of carbon and substitutional elements such as Mn and Mo to the retained austenite/bainitic ferrite interface during aging was observed by APT. This segregation is likely to be the preliminary stage for Mo-C particles’ formation. The aging after pre-straining also induced the decomposition of retained austenite with formation of ferrite and carbides.

Words and things: souvenirs of over-site/over-sight for place-making

This paper addresses the problem of making things in a given place (Qatar), and asks how anticipations and memories of place contribute to practice-based manoeuvres of place-making. Flying across time zones and travelling through sites suggests aspects of place-making that would draw upon both a notion of meteorites coming to earth and an awareness of the sensory consequences of global travelling. What this experience also suggests is an ‘over-sight’ (‘over-site’) in how travellers remember a place for themselves, and how they re-member it for others in the form of souvenirs. Going to a place might often default to an envisioning of pre-emptive or imaginary souvenirs in anticipation of the destination; thinking about what a place might be like is hard to separate from what we think we will eventually take away from it. Thus, the idea to be explored is how we might ‘make in to place’ as much as we ‘make something in-place,’ which perhaps results in ‘making some thing into a place’. Etymologically, souvenir already suggests this in its derivation from Old French: ‘to remember, come to mind.’ How does one ‘come to remembering’ in a place that, like all planetary places, will always be both global and local? Perhaps it depends on how one lands in a place…. Meteoroids remain in orbit around a place: nascent souvenirs always above the horizon, un-made place-makings. Meteors come closer to landing but still, by definition, burn up in the atmospheres of the new place. Meteorites, though, land: they suggest what we mean by the human element of ‘makings in-/to place.’ Travelling from somewhere, to somewhere yet to be fully determined, meteorites (people and/or words and/or senses) reflect the dispersion and compression of sensory (thing-based) and word-based experiences of place. Drawing on the work of Paul Hopper, Paul Carter, Gilles Deleuze and Félix Guattari, Michel Serres, William Desmond and Julia Kristeva, the paper concludes that words evoke a place in which the present might take place, and that the senses evoke a present in which place might take place.

The deep end: pedagogy and the public pool

Diving in to New Materialist theory, this paper explores what might be learnt at a public swimming pool. Writing, sitting, thinking and swimming, the learner enters new spaces and atmospheres, where learning emerges as unpredictable and involving a whole range of human and non human bodies. Public spaces, where we can think about causality and design without the strictures of school curriculum, may emerge as key sites for new understandings of learning where abiding humanist preoccupations can slip away. This presentation involves movement, touching, flesh, smelling, silicone, cotton and water. Be prepared to get changed!

Effects of hyperbaric (6 ATA) pressure on voluntary and evoked skeletal muscle contractile properties

The objective of this study was to investigate the effect of 6 atmospheres of pressure (ATA) on plantar flexors' (PF) voluntary force and activation, force-frequency characteristics, and rate of torque development (RTD). Eight subjects performed PF isometric contractions. Muscle activation was monitored by electromyographic (EMG) activity (PF and dorsiflexors) and the interpolated twitch technique (ITT). Maximal evoked contractions of the PF were elicited at 1, 2, 3, 5, 10, 20, and 40 Hz. PF RTD was calculated with maximal voluntary, 1 and 40 Hz contractions. Hyperbaric pressures significantly decreased PF voluntary torque; 6.2%, ITT activation; 2.8% with a trend for a 19.1% decrease in EMG (p = 0.1). There were no significant differences in the dorsiflexors/PF EMG ratio. One Hz torque was potentiated 15.7% with an increased absolute RTD of 12.8%, but no change in relative RTD. The results suggested hyperbaric-induced decreases in PF activation contributed to voluntary torque loss. A lack of torque reduction with higher frequency tetanic stimulation (2-40 Hz) suggested that 6 ATA does not impair myofilament kinetics, whereas twitch potentiation may include changes in excitation-contraction coupling.

Breathing in the atmosphere : affect and improvised dance performance

Whether conceptually or experientially atmospheres are hazy. Atmospheric situations often emerge without us being able to control or fully apprehend the conditions of their emergence. Atmospheres affect us not at the cognitive level but through embodiment - through the sensory capacities of our bodies and subsequent registers of affect. We feel atmospheres. Dance improvisers also feel what emerges in an improvisation, whether as the adrenalizing effect of the audience’s presence or because the dancer is immersed in their own movement (as the affect of interest). But dance improvisation is a situation in which atmospheres (and their affective impacts) emerge in unpredictable ways. Becoming attuned to ‘what is going on’ is an aspect of improvisational skill but improvised performance is also an exposure to ‘not knowing’ – not knowing what will happen (or how it will change), not knowing what motivated the movement. This exposure to ‘forces of not knowing’ is similar to many atmospheric situations in everyday life which we negotiate according to personal habits and personal levels of discernment. This performative paper picks up on Gernot Bőhme’s concept of a “new aesthetics” such that hazy atmospheres, and the uncertainty of where they come from, can be claimed as part of an aesthetic encounter. It also reflects on the act of breathing as a potential interface between aesthetic and scientific definitions of ‘atmosphere’.