Effect of elemental composition and size on electron confinement in self-assembled SiC quantum dots : a combinatorial approach

A high level of control over quantum dot (QD) properties such as size and composition during fabrication is required to precisely tune the eventual electronic properties of the QD. Nanoscale synthesis efforts and theoretical studies of electronic properties are traditionally treated quite separately. In this paper, a combinatorial approach has been taken to relate the process synthesis parameters and the electron confinement properties of the QDs. First, hybrid numerical calculations with different influx parameters for Si1-x Cx QDs were carried out to simulate the changes in carbon content x and size. Second, the ionization energy theory was applied to understand the electronic properties of Si1-x Cx QDs. Third, stoichiometric (x=0.5) silicon carbide QDs were grown by means of inductively coupled plasma-assisted rf magnetron sputtering. Finally, the effect of QD size and elemental composition were then incorporated in the ionization energy theory to explain the evolution of the Si1-x Cx photoluminescence spectra. These results are important for the development of deterministic synthesis approaches of self-assembled nanoscale quantum confinement structures.

High-rate, low-temperature synthesis of composition controlled hydrogenated amorphous silicon carbide films in low-frequency inductively coupled plasmas

It is commonly believed that in order to synthesize high-quality hydrogenated amorphous silicon carbide (a-Si1-xCx : H) films at competitive deposition rates it is necessary to operate plasma discharges at high power regimes and with heavy hydrogen dilution. Here we report on the fabrication of hydrogenated amorphous silicon carbide films with different carbon contents x (ranging from 0.09 to 0.71) at high deposition rates using inductively coupled plasma (ICP) chemical vapour deposition with no hydrogen dilution and at relatively low power densities (∼0.025 W cm -3) as compared with existing reports. The film growth rate R d peaks at x = 0.09 and x = 0.71, and equals 18 nm min-1 and 17 nm min-1, respectively, which is higher than other existing reports on the fabrication of a-Si1-xCx : H films. The extra carbon atoms for carbon-rich a-Si1-xCx : H samples are incorporated via diamond-like sp3 C-C bonding as deduced by Fourier transform infrared absorption and Raman spectroscopy analyses. The specimens feature a large optical band gap, with the maximum of 3.74 eV obtained at x = 0.71. All the a-Si1-xCx : H samples exhibit low-temperature (77 K) photoluminescence (PL), whereas only the carbon-rich a-Si1-xCx : H samples (x ≥ 0.55) exhibit room-temperature (300 K) PL. Such behaviour is explained by the static disorder model. High film quality in our work can be attributed to the high efficiency of the custom-designed ICP reactor to create reactive radical species required for the film growth. This technique can be used for a broader range of material systems where precise compositional control is required. © 2008 IOP Publishing Ltd.

Tailoring the composition of self-assembled Si1−xCx quantum dots : simulation of plasma/ion-related controls

Precise control of composition and internal structure is essential for a variety of novel technological applications which require highly tailored binary quantum dots (QDs) with predictable optoelectronic and mechanical properties. The delicate balancing act between incoming flux and substrate temperature required for the growth of compositionally graded (Si1-xC x; x varies throughout the internal structure), core-multishell (discrete shells of Si and C or combinations thereof) and selected composition (x set) QDs on low-temperature plasma/ion-flux-exposed Si(100) surfaces is investigated via a hybrid numerical simulation. Incident Si and C ions lead to localized substrate heating and a reduction in surface diffusion activation energy. It is shown that by incorporating ions in the influx, a steady-state composition is reached more quickly (for selected composition QDs) and the composition gradient of a Si1-xCx QD may be fine tuned; additionally (with other deposition conditions remaining the same), larger QDs are obtained on average. It is suggested that ionizing a portion of the influx is another way to control the average size of the QDs, and ultimately, their internal structure. Advantages that can be gained by utilizing plasma/ion-related controls to facilitate the growth of highly tailored, compositionally controlled quantum dots are discussed as well.

Plasma-controlled nanocrystallinity and phase composition of TiO2 : a smart way to enhance biomimetic response

This contribution sheds light on the role of crystal size and phase composition in inducing biomimetic apatite growth on the surface of nanostructured titania films synthesized by reactive magnetron sputtering of Ti targets in Ar+O2 plasmas. Unlike most existing techniques, this method enables one to deposit highly crystalline titania films with a wide range of phase composition and nanocrystal size, without any substrate heating or postannealing. Moreover, by using this dry plasma-based method one can avoid surface hydroxylation at the deposition stage, almost inevitable in wet chemical processes. Results of this work show that high phase purity and optimum crystal size appear to be the essential requirement for efficient apatite formation on magnetron plasma-fabricated bioactive titania coatings. © 2006 Wiley Periodicals, Inc.

Participatory Data Analytics: Collaborative interfaces for data composition and visualisation

This research proposes the development of interfaces to support collaborative, community-driven inquiry into data, which we refer to as Participatory Data Analytics. Since the investigation is led by local communities, it is not possible to anticipate which data will be relevant and what questions are going to be asked. Therefore, users have to be able to construct and tailor visualisations to their own needs. The poster presents early work towards defining a suitable compositional model, which will allow users to mix, match, and manipulate data sets to obtain visual representations with little-to-no programming knowledge. Following a user-centred design process, we are subsequently planning to identify appropriate interaction techniques and metaphors for generating such visual specifications on wall-sized, multi-touch displays.

Coming into an inheritance : family support and Chinese heritage language learning

The critical role that family plays in Chinese Heritage Language learning has gained increasing attention from psychological, political and sociological scholarship. Guided by Bourdieu’s notion of ‘habitus’, our mixed methods sociological study firstly addresses the need for quantitative evidence on the relationship between family support and Chinese Heritage Language proficiency through a survey of 230 young Chinese Australians; and then explores the dynamics of family support of Chinese Heritage Language learning through multiple interviews with five participants. The interview data demonstrate ongoing intergenerational reproduction of Chinese Heritage Language through various forms of family inculcation. Learners’ transition from resistance to commitment is a focus of the analysis. Extant research struggles to theorise the reasons behind this transition. We offer a Bourdieusian explanation that construes the transition as ‘habitus realisation’. Our study has implications for Chinese Heritage Language researchers, Chinese immigrant parents and Chinese teachers.

Tailoring of ion species composition in complex plasmas with charge exchange collisions

A generic approach towards tailoring of ion species composition in reactive plasmas used for nanofabrication of various functional nanofilms and nanoassemblies, based on a simplified model of a parallel-plate rf discharge, is proposed. The model includes an idealized reactive plasma containing two neutral and two ionic species interacting via charge exchange collisions in the presence of a microdispersed solid component. It is shown that the number densities of the desired ionic species can be efficiently managed by adjusting the dilution of the working gas in a buffer gas, rates of electron impact ionization, losses of plasma species on the discharge walls, and surfaces of fine particles, charge exchange rates, and efficiency of three-body recombination processes in the plasma bulk. The results are relevant to the plasma-aided nanomanufacturing of ordered patterns of carbon nanotip and nanopyramid microemitters.

Supporting process model validation through natural language generation

The design and development of process-aware information systems is often supported by specifying requirements as business process models. Although this approach is generally accepted as an effective strategy, it remains a fundamental challenge to adequately validate these models given the diverging skill set of domain experts and system analysts. As domain experts often do not feel confident in judging the correctness and completeness of process models that system analysts create, the validation often has to regress to a discourse using natural language. In order to support such a discourse appropriately, so-called verbalization techniques have been defined for different types of conceptual models. However, there is currently no sophisticated technique available that is capable of generating natural-looking text from process models. In this paper, we address this research gap and propose a technique for generating natural language texts from business process models. A comparison with manually created process descriptions demonstrates that the generated texts are superior in terms of completeness, structure, and linguistic complexity. An evaluation with users further demonstrates that the texts are very understandable and effectively allow the reader to infer the process model semantics. Hence, the generated texts represent a useful input for process model validation.

Boundary swaying

This practice-led research is positioned within my ongoing enquiry into the dancer’s experience and role within the creative process. Gins and Arakawa (1997) and Keane (2007) speak to the unsatisfactory reliance on discipline boundaries, to describe the dynamic lived-experience of interaction. This theorising is of application to this project, which examines creative agency through the lens of Arakawa and Gins’ language prompt, boundary-swaying. In this project the boundaries of movement creator, performer and director overlap and blur through the use of improvisation and multiple cameras. All contributors are invested creatively and compositionally in the ensuing dynamic collaboration, wearing many hats, ‘conceiver, creative thinker, teacher and learner’ (McKechnie 2005, 93; Stevens & McKechnie 2005, 250). This project asked the question, how can the work of Arakawa and Gins to agitate, disrupt, and transform the modus operandi of creative practice between choreographer and practice, dancer and practice and choreographer and dancer? The use of Arakawa and Gins’ philosophy and language prompts within this project stimulated and positively influenced the established creative relationship of researcher and choreographer/artist in the following ways: • Foregrounded the dancers tacit knowledge, first-hand experience, know-how and embodied savviness; • Promoted artistic collaboration, illuminating new creative possibilities, choices and innovation; • Facilitated the distribution of creative authority and agency. This creative work was presented as part of the AG3 ONLINE: the Third International Arakawa and Gins - Architecture and Philosophy Conference. The work was vetted for inclusion by an international panel of examiners.

Gentrification and the artistic dividend : the role of the arts in neighborhood change

Problem, research strategy, and findings: There is a conflict between recent creative placemaking policies intended to promote positive neighborhood development through the arts and the fact that the arts have long been cited as contributing to gentrification and the displacement of lower-income residents. Unfortunately, we do not have data to demonstrate widespread evidence of either outcome. We address the dearth of comprehensive research and inform neighborhood planning efforts by statistically testing how two different groups of arts activities—the fine arts and commercial arts industries—are associated with conditions indicative of revitalization and gentrification in 100 large U.S. metropolitan areas. We find that different arts activities are associated with different types and levels of neighborhood change. Commercial arts industries show the strongest association with gentrification in rapidly changing areas, while the fine arts are associated with stable, slow-growth neighborhoods. Takeaway for practice: This research can help planners to more effectively incorporate the arts into neighborhood planning efforts and to anticipate the potential for different outcomes in their arts development strategies, including gentrification-related displacement.

Looking beyond image and tourism : the role of flagship cultural projects in local arts development

State and local governments frequently look to flagship cultural projects to improve the city image and catalyze tourism but, in the process, often overlook their potential to foster local arts development. To better understand this role, the article examines if and how cultural institutions in Los Angeles and San Francisco attract and support arts-related activity. The analysis reveals that cultural flagships have mixed success in generating arts-based development and that their ability may be improved through attention to the local context, facility and institutional characteristics, and the approach of the sponsoring agencies. Such knowledge is useful for planners to enhance their revitalization efforts, particularly as the economic development potential of arts organizations and artists has become more apparent.

Art Spaces, Art Places : Examining Neighborhood Preferences of New York Arts Organizations

This report builds on and extends a diverse literature that examines the location patterns of the arts and creative industries through analysis of a database of arts nonprofit organizations from the New York State Cultural Data Project. We confirm the link between arts organizations and the urban core and creative economy, but challenge the assumption that arts tend to locate in ethnic and disadvantaged neighborhoods. By identifying key neighborhood attributes associated with distinct types of arts organizations, we can better identify potential sites conducive to nurturing additional artistic activity and inform strategies to engage organizations in neighborhoods that are underserved in the arts.

Visual arts learning with iPads

In this chapter Knight & Dooley discuss arts learning and issues of educational authenticity via children’s engagement with iPads (O’Mara & Laidlaw 2011; Shifflet, Toledo & Mattoon 2012). The chapter begins by considering common perceptions about art and how these popular beliefs and conditions affect and influence how children’s art is defined and valorized. The art produced by children using iPads is then discussed through key observations and reflections, and the chapter concludes with some recommendations when selecting apps for making art.

Understanding the information literacy experiences of EFL (English as a Foreign Language) students

Purpose – This paper outlines research that explores the information literacy experiences of EFL (English as a Foreign Language) students. The question explored in this research was: how do EFL students experience information literacy. Design/Methodology/Approach – This study used phenomenography, a relational approach to explore the information literacy experiences of EFL students. Phenomenography studies the qualitatively different ways a phenomenon is experienced in the world around us. Findings – This research revealed that EFL students experienced information literacy in four qualitatively different ways. The four categories revealed through the data were: process, quality, language and knowledge. This research found that language impacted on EFL students’ experiences of information literacy and revealed that EFL students applied various techniques and strategies when they read, understood, organised and translated information. Research limitations/implications – This research was conducted in a specific cultural and educational context, therefore the results might not reflect the experiences of EFL students in other cultural or educational contexts. Practical implications – The findings from this research offer an important contribution to information literacy practice by providing important insights about EFL students’ experiences and perceptions of information and learning that can be used to inform curriculum development in second language learning contexts. Originality/Value - There is currently a lack of research using a relational approach to investigate EFL students’ experiences of information literacy. There is also limited research that explores the impact language has on information literary and learning in English as a foreign or second language contexts.

The child pose : the role of the nonhuman natural world in recovery from psychological trauma

This thesis by creative work explores relationships among human beings, the nonhuman natural world and language. It addresses the central research question: 'How can a novel embody a narrative of recovery from psychological trauma in which recovery is primarily a function of the character's subjective interaction with nature?' The novel, 'The Child Pose', tells the story of a woman's recovery from psychological trauma. The thesis draws on the psychoanalytic theory of Jacques Lacan, who saw the human subject as fundamentally split and alienated, and therefore inherently vulnerable to being destabilised by trauma. Situating the narrative of recovery within the emerging fields of ecocriticism and ecopsychology, the research constructs psychological recovery through interaction with nature as a transformation of subjectivity: the creation of a new, more stable and connected kind of subject, which Jordan (2012) has called 'the ecological subject'.