Formation mechanisms of secondary organic aerosols in relation to laser printer emissions

Due to their large surface area, complex chemical composition and high alveolar deposition rate, ultrafine particles (UFPs) (< 0.1 ìm) pose a significant risk to human health and their toxicological effects have been acknowledged by the World Health Organisation. Since people spend most of their time indoors, there is a growing concern about the UFPs present in some indoor environments. Recent studies have shown that office machines, in particular laser printers, are a significant indoor source of UFPs. The majority of printer-generated UFPs are organic carbon and it is unlikely that these particles are emitted directly from the printer or its supplies (such as paper and toner powder). Thus, it was hypothesised that these UFPs are secondary organic aerosols (SOA). Considering the widespread use of printers and human exposure to these particles, understanding the processes involved in particle formation is of critical importance. However, few studies have investigated the nature (e.g. volatility, hygroscopicity, composition, size distribution and mixing state) and formation mechanisms of these particles. In order to address this gap in scientific knowledge, a comprehensive study including state-of-art instrumental methods was conducted to characterise the real-time emissions from modern commercial laser printers, including particles, volatile organic compounds (VOCs) and ozone (O3). The morphology, elemental composition, volatility and hygroscopicity of generated particles were also examined. The large set of experimental results was analysed and interpreted to provide insight into: (1) Emissions profiles of laser printers: The results showed that UFPs dominated the number concentrations of generated particles, with a quasi unimodal size distribution observed for all tests. These particles were volatile, non-hygroscopic and mixed both externally and internally. Particle microanalysis indicated that semi-volatile organic compounds occupied the dominant fraction of these particles, with only trace quantities of particles containing Ca and Fe. Furthermore, almost all laser printers tested in this study emitted measurable concentrations of VOCs and O3. A positive correlation between submicron particles and O3 concentrations, as well as a contrasting negative correlation between submicron particles and total VOC concentrations were observed during printing for all tests. These results proved that UFPs generated from laser printers are mainly SOAs. (2) Sources and precursors of generated particles: In order to identify the possible particle sources, particle formation potentials of both the printer components (e.g. fuser roller and lubricant oil) and supplies (e.g. paper and toner powder) were investigated using furnace tests. The VOCs emitted during the experiments were sampled and identified to provide information about particle precursors. The results suggested that all of the tested materials had the potential to generate particles upon heating. Nine unsaturated VOCs were identified from the emissions produced by paper and toner, which may contribute to the formation of UFPs through oxidation reactions with ozone. (3) Factors influencing the particle emission: The factors influencing particle emissions were also investigated by comparing two popular laser printers, one showing particle emissions three orders of magnitude higher than the other. The effects of toner coverage, printing history, type of paper and toner, and working temperature of the fuser roller on particle number emissions were examined. The results showed that the temperature of the fuser roller was a key factor driving the emission of particles. Based on the results for 30 different types of laser printers, a systematic positive correlation was observed between temperature and particle number emissions for printers that used the same heating technology and had a similar structure and fuser material. It was also found that temperature fluctuations were associated with intense bursts of particles and therefore, they may have impact on the particle emissions. Furthermore, the results indicated that the type of paper and toner powder contributed to particle emissions, while no apparent relationship was observed between toner coverage and levels of submicron particles. (4) Mechanisms of SOA formation, growth and ageing: The overall hypothesis that UFPs are formed by reactions with the VOCs and O3 emitted from laser printers was examined. The results proved this hypothesis and suggested that O3 may also play a role in particle ageing. In addition, knowledge about the mixing state of generated particles was utilised to explore the detailed processes of particle formation for different printing scenarios, including warm-up, normal printing, and printing without toner. The results indicated that polymerisation may have occurred on the surface of the generated particles to produce thermoplastic polymers, which may account for the expandable characteristics of some particles. Furthermore, toner and other particle residues on the idling belt from previous print jobs were a very clear contributing factor in the formation of laser printer-emitted particles. In summary, this study not only improves scientific understanding of the nature of printer-generated particles, but also provides significant insight into the formation and ageing mechanisms of SOAs in the indoor environment. The outcomes will also be beneficial to governments, industry and individuals.

Laying the Groundwork for the Successful Deployment of Communication Interception Technology (CIT) in Modern Policing

With the growth and development of communication technology there is an increasing need for the use of interception technologies in modern policing. Law enforcement agencies are faced with increasingly sophisticated and complex criminal networks that utilise modern communication technology as a basis for their criminal success. In particular, transnational organised crime (TOC) is a diverse and complicated arena, costing global society in excess of $3 trillion annually, a figure that continues to grow (Borger, 2007) as crime groups take advantage of disappearing borders and greater profit markets. However, whilst communication can be a critical success factor for criminal enterprise it is also a key vulnerability. It is this vulnerability that the use of CIT, such as phone taps or email interception, can exploit. As such, law enforcement agencies now need a method and framework that allows them to utilise CIT to combat these crimes efficiently and successfully. This paper provides a review of current literature with the specific purpose of considering the effectiveness of CIT in the fight against TOC and the groundwork that must be laid in order for it to be fully exploited. In doing so, it fills an important gap in current research, focusing on the practical implementation of CIT as opposed to the traditional area of privacy concerns that arise with intrusive methods of investigation. The findings support the notion that CIT is an essential intelligence gathering tool that has a strong place within the modern policing arena. It identifies that the most effective use of CIT is grounded within a proactive, intelligence‐led framework and concludes that in order for this to happen Australian authorities and law enforcement agencies must re‐evaluate and address the current legislative and operational constraints placed on the use of CIT and the culture that surrounds intelligence in policing.

Modern construction economics [Book Review]

The editor, Gerard de Valence, points out in the preface, this book is neither a textbook nor a guide to what is done by construction managers and construction economists – read quantity surveyors and the like. Rather, de Valence notes it comprises a collection of chapters each of which focus on matters at the industry level and, in doing so, illustrates that a substantially improved understanding of the building and construction industry can be gained beyond the economics of delivering projects. Before giving some thought to how far each of the chapters achieve this, it’s worth reflecting on the virtues of developing construction economics as its own discipline or sub-discipline in general economics and the bold manner by which de Valence is proposing we do this. That is, de Valence proposes partitioning industry and project economics - as explained in the preface and in Chapter 1. de Valence’s view that “the time seems right” for these developments is also worthy of some consideration.

From the margin to the centre : towards an art strategy for the ethnic enclaves in the city

Sunnybank represents a distinctly Australian take on the classic ‘Chinatown’ – or indeed other ethic community enclaves such as ‘little Italy’, ‘little Bombay’, ‘little Athens’ and so on. In the Northern Hemisphere these tended to grow up in the dense working class neighbourhoods of industrial cities, especially in port cities like Liverpool, London, New York and San Francisco. The existing Chinatowns of Sydney and Melbourne, and to some extent Brisbane’s Fortitude Valley, are of this variety. In the late 1970s, with the growth of suburbanisation and the de-industrialisation and consequent dereliction of the ‘inner city’, these ethnic communities were one of the few signs of life in the city. Apart from the daily commute into the CBD, business with the city council or a trip to the big shopping streets these areas were one of the few reasons for visiting city centres stigmatised by urban decay and petty crime.

The art of re-industrialisation in Shanghai

This paper deals with the development of ‘art clusters’ and their relocation in the city of Shanghai. It first looks at the revival of the city’s old inner city industrial area (along banks of Suzhou River) through ‘organic’ or ‘alternative’ artist-led cultural production; second, it describes the impact on these activities of the industrial restructuring of the wider city, reliant on large-scale real estate development, business services and global finance; and finally, outlines the relocation of these arts (and related) cultural industries to dispersed CBD locations as a result of those spatial, industrial and policy changes.

Clichés, communication and the meaning of existence

This catalogue essay discusses the work of contemporary Brisbane artist Grant Stevens. It provides a survey of his video work and discusses the artist's use of cliche and other mediated formulas to explore the nature of media and its impact on consciousness in the early 21st century.

Grounded Media: Expanding the Scope of Ecological Art Practices Within New Media Arts Culture

‘Grounded Media’ is a form of art practice focused around the understanding that our ecological crisis is also a cultural crisis, perpetuated by our sense of separation from the material and immaterial ecologies upon which we depend. This misunderstanding of relationships manifests not only as environmental breakdown, but also in the hemorrhaging of our social fabric. ‘Grounded Media’ is consistent with an approach to media art making that I name ‘ecosophical’ and ‘praxis-led’ – which seeks through a range of strategies, to draw attention to the integrity, diversity and efficacy of the biophysical, social and electronic environments of which we are an integral part. It undertakes this through particular choices of location, interaction design,participative strategies and performative direction. This form of working emerged out of the production of two major projects, Grounded Light [8] and Shifting Intimacies [9] and is evident in a recent prototypical wearable art project called In_Step [6]. The following analysis and reflections will assist in promoting new, sustainable roles for media artists who are similarly interested in attuning their practices.

Arts and creative industries : a historical overview; and an Australian conversation

Australia should seek new and liberating ways to bring together the arts, popular culture and the creative industries, according to Arts and creative industries. The report, funded by the Australia Council for the Arts and prepared by Professor Justin O’Connor of the Creative Industries Faculty at Queensland University of Technology, looks at ways in which the policy relationship between these often polarised sectors of arts and creative industries might be re-thought and approached more productively. The report is in two parts, commencing with An Australian conversation, in which Professor O’Connor, with Stuart Cunningham and Luke Jaaniste, document a series of in depth interviews with 18 leading practitioners across the creative industries. They discuss their perceptions of the similarities, differences and connections between the arts and creative industries. The interviews frequently returned to the fundamental question of what was meant by ‘art’ and ‘creative industries’. The second, larger part of Arts and creative industries, addresses this question through an extensive review of the discussions of art and its relation to society and culture over the last few centuries. A historical overview highlights the importance that art has had in developing our comprehension of the modern world. It also examines the enthusiasm for the creative industries over the last 15 years or so and the impact this has had on creative policy-making. Arts and creative industries suggests there is no dividing line between publicly-funded arts, popular culture and the blossoming businesses of the creative sector – and national policy should reflect this. This study was commissioned by the Australia Council as part of a long-running and productive relationship between the council and the ARC Centre of Excellence on Creative Industries and Innovation at the Queensland University of Technology.

Tabernacle-Game world

Tabernacle is an experimental game world-building project which explores the relationship between the map and the 3-dimensional visualisation enabled by high-end game engines. The project is named after the 6th century tabernacle maps of Cosmas Indicopleustes in his Christian Topography. These maps articulate a cultural or metaphoric, rather than measured view of the world, contravening Alper's distinction which observes that “maps are measurement, art is experience”. The project builds on previous research into the use of game engines and 3D navigable representation to enable cultural experience, particularly non-Western cultural experiences and ways of seeing. Like the earlier research, Tabernacle highlights the problematic disjuncture between the modern Cartesian map structures of the engine and the mapping traditions of non-Western cultures. Tabernacle represents a practice-based research provocation. The project exposes assumptions about the maps which underpin 3D game worlds, and the autocratic tendencies of world construction software. This research is of critical importance as game engines and simulation technologies are becoming more popular in the recreation of culture and history. A key learning from the Tabernacle project was the ways in which available game engines – technologies with roots in the Enlightenment - constrained the team’s ability to represent a very different culture with a different conceptualisation of space and maps. Understanding the cultural legacies of the software itself is critical as we are tempted by the opportunities for representation of culture and history that they seem to offer. The project was presented at Perth Digital Arts and Culture in 2007 and reiterated using a different game engine in 2009. Further reflections were discussed in a conference paper presented at OZCHI 2009 and a peer-reviewed journal article, and insights gained from the experience continue to inform the author’s research.

Running dry : Brisbane's public fountains

"Does heat have a cooling effect on culture? Sweat argues the reverse: culture thrives in the subtropical zones. While acknowledging that the subtropical generates ambivalence—being cast as alternately idyllic or hellish—Sweat nonetheless seeks to develop the specific voices of subtropical cultures. The uneasy place of this sweaty discourse is explored across art, literature, architecture, and the built environment. In particular, Sweat focuses on the most commonly experienced situation, the everyday house. While it addresses subjects from Japan, Brazil, and France, Sweat centres on Brisbane, Queensland—long in the shadow of Sydney and Melbourne in the Australian cultural psyche—due to its enduring and self-conscious attention to subtropical living..." -- online book description

The story of the sixties...a pile-up on the freeway of advanced art

When does 1960s art begin and end? Certainly, aside from a few affinities, the decade’s artistic output does not exactly correspond to its popular conception as the ‘Swinging Sixties’. While it was rare that psychedelic art was truly challenging, the decade saw a number of perceptions change regarding the aims, boundaries and possibilities of experiencing art. Thus, this era has come to represent a watershed or crisis in modernist art. While in the Australian context many of these nascent trends were properly realised in the 1970s – with the full force and impact of post-object art – other challenges were first articulated in the 1950s. So, like any other demarcation of a decade, its limits and boundaries are porous.

Two ways : between tradition and innovation

Can art be simultaneously modern and traditional? This short piece examines the perplexities involved in seeking to address both cultural parameters at once in indigenous art of Australia.

On secrets, lies, and fiction : girls learning the art of survival

This chapter’s interest in fiction’s relationship to truth, lies, and secrecy is not so much a matter of how closely fiction resembles or mirrors the world (its mimetic quality), or what we can learn from fiction (its epistemological value). Rather, the concern is both literary and philosophical: a literary concern that takes into account how texts that thematise secrecy work to withhold and to disclose their secrets as part of the process of narrating and sequencing; and a philosophical concern that considers how survival is contingent on secrets and other forms of concealment such as lies, deception, and half-truths. The texts selected for examination are: Secrets (2002), Skim (2008), and Persepolis: The Story of a Childhood (2003). These texts draw attention to the ways in which the lies and secrets of the female protagonists are part of the intricate mechanism of survival, and demonstrate the ways in which fiction relies upon concealment and revelation as forms of truth-telling.

Brisbane ~ Tokyo : subtropical lifestyle research

Tokyo-based architectural firm Atelier Bow-Wow's interest in Queensland's timber vernacular housing style can be traced back to 2006. In 2009, the group undertook a study of Brisbane housing types, which forms the basis of this chapter. Atelier Bow-Wow suggested that the study of Brisbane housing types could provide insights into architectural alternatives for Tokyo that might ameliorate the warming "heat island" effect exacerbated by widespread urbanisation. In addition, they examined the veranda of the "Queenslander" as a way of mitigating social isolation in aging population.