Fabrication and characterization of polyterpenol as an insulating layer and incorporated organic field effect transistor

A non-synthetic polymer material, polyterpenol, was fabricated using a dry polymerization process namely RF plasma polymerization from an environmentally friendly monomer and its surface, optical and electrical properties investigated. Polyterpenol films were found to be transparent over the visible wavelength range, with a smooth surface with an average roughness of less than 0.4 nm and hardness of 0.4 GPa. The dielectric constant of 3.4 for polyterpenol was higher than that of the conventional polymer materials used in the organic electronic devices. The non-synthetic polymer material was then implemented as a surface modification of the gate insulator in field effect transistor (OFET) and the properties of the device were examined. In comparison to the similar device without the polymer insulating layer, the polyterpenol based OFET device showed significant improvements. The addition of the polyterpenol interlayer in the OFET shifted the threshold voltage significantly; + 20 V to -3 V. The presence of trapped charge was not observed in the polyterpenol interlayer. This assisted in the improvement of effective mobility from 0.012 to 0.021 cm 2/Vs. The switching property of the polyterpenol based OFET was also improved; 107 compared to 104. The results showed that the non-synthetic polyterpenol polymer film is a promising candidate of insulators in electronic devices.

Fabrication and characterization of plasma polymer thin films from monoterpene alcohols for applications in organic electronics and biotechnology

After more than twenty years of basic and applied research, the use of nanotechnology in the design and manufacture of nanoscale materials is rapidly increasing, particularly in commercial applications that span from electronics across renewable energy areas, and biomedical devices. Novel polymers are attracting significant attention for they promise to provide a low−cost high−performance alternative to existing materials. Furthermore, these polymers have the potential to overcome limitations imposed by currently available materials thus enabling the development of new technologies and applications that are currently beyond our reach. This work focuses on the development of a range of new low−cost environmentally−friendly polymer materials for applications in areas of organic (flexible) electronics, optics, and biomaterials. The choice of the monomer reflects the environmentally−conscious focus of this project. Terpinen−4−ol is a major constituent of Australian grown Melaleuca alternifolia (tea tree) oil, attributed with the oil's antimicrobial and anti−inflammatory properties. Plasma polymerisation was chosen as a deposition technique for it requires minimal use of harmful chemicals and produces no hazardous by−products. Polymer thin films were fabricated under varied process conditions to attain materials with distinct physico−chemical, optoelectrical, biological and degradation characteristics. The resultant materials, named polyterpenol, were extensively characterised using a number of well−accepted and novel techniques, and their fundamental properties were defined. Polyterpenol films were demonstrated to be hydrocarbon rich, with variable content of oxygen moieties, primarily in the form of hydroxyl and carboxyl functionalities. The level of preservation of original monomer functionality was shown to be strongly dependent on the deposition energy, with higher applied power increasing the molecular fragmentation and substrate temperature. Polyterpenol water contact angle contact angle increased from 62.7° for the 10 W samples to 76.3° for the films deposited at 100 W. Polymers were determined to resist solubilisation by water, due to the extensive intermolecular and intramolecular hydrogen bonds present, and other solvents commonly employed in electronics and biomedical processing. Independent of deposition power, the surface topography of the polymers was shown to be smooth (Rq <0.5 nm), uniform and defect free. Hardness of polyterpenol coatings increased from 0.33 GPa for 10 W to 0.51 GPa for 100 W (at 500 μN load). Coatings deposited at higher input RF powers showed less mechanical deformation during nanoscratch testing, with no considerable damage, cracking or delamination observed. Independent of the substrate, the quality of film adhesion improved with RF power, suggesting these coatings are likely to be more stable and less susceptible to wear. Independent of fabrication conditions, polyterpenol thin films were optically transparent, with refractive index approximating that of glass. Refractive index increased slightly with deposition power, from 1.54 (10 W) to 1.56 (100 W) at 500 nm. The optical band gap values declined with increasing power, from 2.95 eV to 2.64 eV, placing the material within the range for semiconductors. Introduction of iodine impurity reduced the band gap of polyterpenol, from 2.8 eV to 1.64 eV, by extending the density of states more into the visible region of the electromagnetic spectrum. Doping decreased the transparency and increased the refractive index from 1.54 to 1.70 (at 500 nm). At optical frequencies, the real part of permittivity (k) was determined to be between 2.34 and 2.65, indicating a potential low-k material. These permittivity values were confirmed at microwave frequencies, where permittivity increased with input RF energy – from 2.32 to 2.53 (at 10 GHz ) and from 2.65 to 2.83 (at 20 GHz). At low frequencies, the dielectric constant was determined from current−voltage characteristics of Al−polyterpenol−Al devices. At frequencies below 100 kHz, the dielectric constant varied with RF power, from 3.86 to 4.42 at 1 kHz. For all samples, the resistivity was in order of 10⁸−10⁹ _m (at 6 V), confirming the insulating nature of polyterpenol material. In situ iodine doping was demonstrated to increase the conductivity of polyterpenol, from 5.05 × 10⁻⁸ S/cm to 1.20 × 10⁻⁶ S/cm (at 20 V). Exposed to ambient conditions over extended period of time, polyterpenol thin films were demonstrated to be optically, physically and chemically stable. The bulk of ageing occurred within first 150 h after deposition and was attributed to oxidation and volumetric relaxation. Thermal ageing studies indicated thermal stability increased for the films manufactured at higher RF powers, with degradation onset temperature associated with weight loss shifting from 150 ºC to 205 ºC for 10 W and 100 W polyterpenol, respectively. Annealing the films to 405 °C resulted in full dissociation of the polymer, with minimal residue. Given the outcomes of the fundamental characterisation, a number of potential applications for polyterpenol have been identified. Flexibility, tunable permittivity and loss tangent properties of polyterpenol suggest the material can be used as an insulating layer in plastic electronics. Implementation of polyterpenol as a surface modification of the gate insulator in pentacene-based Field Effect Transistor resulted in significant improvements, shifting the threshold voltage from + 20 V to –3 V, enhancing the effective mobility from 0.012 to 0.021 cm²/Vs, and improving the switching property of the device from 10⁷ to 10⁴. Polyterpenol was demonstrated to have a hole transport electron blocking property, with potential applications in many organic devices, such as organic light emitting diodes. Encapsulation of biomedical devices is also proposed, given that under favourable conditions, the original chemical and biological functionality of terpinen−4−ol molecule can be preserved. Films deposited at low RF power were shown to successfully prevent adhesion and retention of several important human pathogens, including P. aeruginosa, S. aureus, and S. epidermidis, whereas films deposited at higher RF power promoted bacterial cell adhesion and biofilm formation. Preliminary investigations into in vitro biocompatibility of polyterpenol demonstrated the coating to be non−toxic for several types of eukaryotic cells, including Balb/c mice macrophage and human monocyte type (HTP−1 non-adherent) cells. Applied to magnesium substrates, polyterpenol encapsulating layer significantly slowed down in vitro biodegradation of the metal, thus increasing the viability and growth of HTP−1 cells. Recently, applied to varied nanostructured titanium surfaces, polyterpenol thin films successfully reduced attachment, growth, and viability of P. aeruginosa and S. aureus.

Remembering the Peel Island Lazaret through re-imagining the Teerk Roo Ra forest

This paper discusses my current research which aims to re-member the site of the Peel Island Lazaret through re-imagining the Teerk Roo Ra forest as a series of animated artworks. Teerk Roo Ra National Park (formally known as Peel Island) is a small island in Moreton Bay, Queensland and is visible on the ferry journey from Cleveland to Stradbroke Island. The island has an intriguing history, and is the site of a former Lazaret and quarantine station. The Lazaret treated patients diagnosed with Hansen’s disease (or Leprosy), and operated between 1907 and 1959. In this paper I will discuss conceptions of the non-indigenous historical context of the Peel Island Lazaret and the notion of the liminal state (Turner,1967). Through this discussion conceptions of place from Australian cultural theorist Ross Gibson are also examined. The concept of two overlapping realms is then explored through the clues and shared stories about the people who inhabited the site. There is then an explanation of my own approach to re-member this place through re-imagining the forest that witnessed the events of the Lazaret. I then draw on theories of the uncanny from German Psychiatrist Ernst Jentsch, Austrian Neurologist Sigmund Freud and South African animation theorist Meg Rickards to argue that my experience of the forest of Teerk Roo Ra was an uncanny experience where two worlds or states of mind existed simultaneously and overlapped, causing a viscerally unsettling uncanny experience. Through an analysis of Czech Surrealist Animator Jan Švankmajer’s cinematic narrative Down to the cellar (1982), my creative work Structure #24(2011), and Australian Artist Patricia Piccinini’s cinematic artwork The Gathering (2007), I discuss the situation of the inanimate and the animate co-existing simultaneously. Using this approach I propose an understanding of the uncanny as an intellectual uncertainty as outlined by Jentsch (1906). I also develop the notion of the familiar being concealed and becoming unfamiliar through mimicry (Freud, 1919). These discussions form an introduction to my creative work Nocturne #5(2014) which re-members the forests of Teerk Roo Ra as an uncanny place primarily expressed through animation.

Case study 1: Nursing informatics and eHealth in Australia

There are currently many changes happening in nursing and healthcare in Australia. Healthcare reform has been high on the national government agenda and has created many changes in healthcare including eHealth. Healthcare information technologies and informatics are providing many challenges and excitement for the future of healthcare in Australia. The challenge for professional nursing organisations and nursing leaders of Australia is to be proactive in developments and initiatives for nursing to remain visible and viable in health care systems to safeguard the profession for the future as health care reform is implemented.

Constructive alignment: A journey for new eyes

The needs of students engaged in enterprise education programs are of ever growing importance. This paper considers the pedagogical challenges that confront the designers of such-programs. It is argued that it is the designer's mindset that will most likely determine the program's outcomes. That, regardless of where such programs reside, their development should be guided by a learner-centred approach. The recently developed hic et nunc framework, provides an example of such a student-centred approach. The process through which student learning outcomes occur is argued to be essentially Darwinian in nature. Taking into account both knowledge and skills, it is also argued that assessment of desirable learning outcomes should occur in visible interaction spaces. That the failure to eliminate invisible interaction spaces from such programs is an invitation for criticism from those who favour a more traditional lecturer-centred approach to teaching and learning.

Combined effect of double antireflection coating and reversible molecular doping on performance of few-layer graphene/n-silicon Schottky barrier solar cells

Few-layer graphene films were grown by chemical vapor deposition and transferred onto n-type crystalline silicon wafers to fabricate graphene/n-silicon Schottky barrier solar cells. In order to increase the power conversion efficiency of such cells the graphene films were doped with nitric acid vapor and an antireflection treatment was implemented to reduce the sunlight reflection on the top of the device. The doping process increased the work function of the graphene film and had a beneficial effect on its conductivity. The deposition of a double antireflection coating led to an external quantum efficiency up to 90% across the visible and near infrared region, the highest ever reported for this type of devices. The combined effect of graphene doping and antireflection treatment allowed to reach a power conversion efficiency of 8.5% exceeding the pristine (undoped and uncoated) device performance by a factor of 4. The optical properties of the antireflection coating were found to be not affected by the exposure to nitric acid vapor and to remain stable over time.

Infrared thermal imaging for automated detection of diabetic foot complications

Background Although thermal imaging can be a valuable technology in the prevention and management of diabetic foot disease, it is not yet widely used in clinical practice. Technological advancement in infrared imaging increases its application range. The aim was to explore the first steps in the applicability of high-resolution infrared thermal imaging for noninvasive automated detection of signs of diabetic foot disease. Methods The plantar foot surfaces of 15 diabetes patients were imaged with an infrared camera (resolution, 1.2 mm/pixel): 5 patients had no visible signs of foot complications, 5 patients had local complications (e.g., abundant callus or neuropathic ulcer), and 5 patients had difuse complications (e.g., Charcot foot, infected ulcer, or critical ischemia). Foot temperature was calculated as mean temperature across pixels for the whole foot and for specified regions of interest (ROIs). Results No diferences in mean temperature >1.5 °C between the ipsilateral and the contralateral foot were found in patients without complications. In patients with local complications, mean temperatures of the ipsilateral and the contralateral foot were similar, but temperature at the ROI was >2 °C higher compared with the corresponding region in the contralateral foot and to the mean of the whole ipsilateral foot. In patients with difuse complications, mean temperature diferences of >3 °C between ipsilateral and contralateral foot were found. Conclusions With an algorithm based on parameters that can be captured and analyzed with a high-resolution infrared camera and a computer, it is possible to detect signs of diabetic foot disease and to discriminate between no, local, or difuse diabetic foot complications. As such, an intelligent telemedicine monitoring system for noninvasive automated detection of signs of diabetic foot disease is one step closer. Future studies are essential to confirm and extend these promising early findings.

Governing literacies: Securing literate subjects

This review of literacy research explores ways in which literacy has come to be understood as a problem about human populations. I describe connections between literacy education and the biopolitical government of population, especially the relationship between liberal forms of government and the administration of human freedom. The review takes into account ways in which literacy is implicated in the cultivation of civil society by attending to the interests, as well as to the conduct, of human subjects. I draw on research available in English from across the globe, which provides an overview of how literacy has been rethought and conceptualised through ethnographic, historical and classroom based studies. I discuss claims made for literacy, the way that human populations have been made visible in relation to their literacy practices and the social contexts of their use. The review informs research of representations of literacy as a tool for securing national interests.

From mundane to smart: Exploring interactions with ‘smart' design objects

In addition to functional and technological features, the role of augmented objects should also be seen in terms of how effectively they fit into the everyday practices of users and how they enhance users' experiences. In this article, the authors introduce a low-tech, internet-of-things technology called CAM (Cooperative Artefact Memory) that is used as a collaborative tool in design studio environments. CAM works as an object memory technology and allows industrial and product designers to collaboratively store relevant information onto their physical design objects, such as sketches, collages, storyboards, and physical mock-ups in the form of messages, annotations and external web links. In the context of this study, CAM serves as an important probing device to understand designers' interaction and experiences with augmented design objects, in their natural environment. The authors carried out a small-scale field trial of CAM in an academic design studio, over three student design projects. In this article, they discuss the findings of their field trial and show how CAM was used by the participants, how it was integrated into the design process and how it was appropriated for different purposes. The authors also found that CAM supported coordination and awareness within the design teams, yet its serendipitous and asynchronous nature facilitated creative and playful interactions between team members. In general, the results show how CAM transformed mundane design objects into “smart” objects that made the creative and playful side of cooperative design visible.

Re-thinking discourses of teacher professionalism in early childhood education: An Australian perspective

The professionalism of early childhood teachers has been the subject of increasing attention globally for over a decade (Moss, 2006; Osgood, 2012; Urban, 2010. In order to understand ways pre-service early childhood teachers make sense of professionalism, this chapter examines some of the discourses of early childhood teacher professionalism, and focuses on qualifications as one way in which being professional is discursively produced. In particular, the chapter makes visible some of the discursive tensions involved in student intentions to pursue careers in primary school teaching/specialist early childhood teacher in primary school, rather than in the child care sector. In doing so, it makes visible some of the effects of particular discourses of professionalism and the ways they may be taken up by students as they make important career decisions.

Displaying and celebrating the "other": A study of the mission, scope, and roles of ethnic museums in Los Angeles

In the last thirty years, ethnic museums have mushroomed in American cities. Although this is certainly a national phenomenon, it has been particularly evident in Los Angeles. In this paper we examine the genesis and evolution of these emerging institutions. We survey the mission, scope, and role of ethnic museums in Los Angeles, and we contrast them with the stated mission and scope of “mainstream” museums in the city. We further present case studies of three Los Angeles ethnic museums. The museums vary considerably in the ways they perceive their role in the community, the city, and the nation and in the preservation and display of ethnic culture. At their best, ethnic museums serve to make new art and histories more accessible and visible and provide a forum in which to debate contemporary issues of politics and identity. The paper highlights some of the tensions faced by ethnic museums as they seek to define their audience and role(s) in multi-ethnic, twenty-first century Los Angeles.

Surface-mediated selective photocatalytic aerobic oxidation reactions on TiO2 nanofibres

N-doped TiO2 nanofibres were observed to possess lower aerobic oxidation activity than undoped TiO2 nanofibres in the selective photocatalytic aerobic oxidation of enzylamine and 4-methoxybenzyl alcohol. This was attributed to the reduction free energy of O2 adsorption in the vicinity of nitrogen dopant sites, as indicated by density functional theory (DFT) calculations when three-coordinated oxygen atoms are substituted by nitrogen atoms. It was found that the activity recovered following a controlled calcination of the N-doped NFs in air. The dependence of the conversion of benzylamine and 4-methoxybenzyl alcohol on the intensity of light irradiation confirmed that these reactions were driven by light. Action spectra showed that the two oxidation reactions are responsive to light from the UV region through to the visible light irradiation range. The extended light absorption wavelength range in these systems compared to pure TiO2 materials was found to result from the formation of surface complex species following adsorption of reactants onto the catalysts' surface, evidenced by the in situ IR experiment. Both catalytic and in situ IR results reveal that benzaldehyde is the intermediate in the aerobic oxidation of benzylamine to N-benzylidenebenzylamine process.

Metal nanoparticle photocatalysts: Emerging processes for green organic synthesis

Metal nanoparticle photocatalysts have attracted recent interest due to their strong absorption of visible and ultraviolet light. The energy absorbed by the metal conduction electrons and the intense electric fields in close proximity, created by the localized surface plasmon resonance effect, makes the crucial contribution of activating the molecules on the metal nanoparticles which facilitates chemical transformation. There are now many examples of successful reactions catalyzed by supported nanoparticles of pure metals and of metal alloys driven by light at ambient or moderate temperatures. These examples demonstrate these materials are a novel group of efficient photocatalysts for converting solar energy to chemical energy and that the mechanisms are distinct from those of semiconductor photocatalysts. We present here an overview of recent research on direct photocatalysis of supported metal nanoparticles for organic synthesis under light irradiation and discuss the significant reaction mechanisms that occur through light irradiation.

Deploying speaker verification techniques to vision-based RPA detect and avoid

Detect and Avoid (DAA) technology is widely acknowledged as a critical enabler for unsegregated Remote Piloted Aircraft (RPA) operations, particularly Beyond Visual Line of Sight (BVLOS). Image-based DAA, in the visible spectrum, is a promising technological option for addressing the challenges DAA presents. Two impediments to progress for this approach are the scarcity of available video footage to train and test algorithms, in conjunction with testing regimes and specifications which facilitate repeatable, statistically valid, performance assessment. This paper includes three key contributions undertaken to address these impediments. In the first instance, we detail our progress towards the creation of a large hybrid collision and near-collision encounter database. Second, we explore the suitability of techniques employed by the biometric research community (Speaker Verification and Language Identification), for DAA performance optimisation and assessment. These techniques include Detection Error Trade-off (DET) curves, Equal Error Rates (EER), and the Detection Cost Function (DCF). Finally, the hybrid database and the speech-based techniques are combined and employed in the assessment of a contemporary, image based DAA system. This system includes stabilisation, morphological filtering and a Hidden Markov Model (HMM) temporal filter.

Playing the policy game: A review of the barriers and enablers of nutrition policy change

- Objective To progress nutrition policy change and develop more effective advocates, it is useful to consider real-world factors and practical experiences of past advocacy efforts to determine the key barriers and enablers to nutrition policy change. This review aimed to identify and synthesize the enablers and barriers to public policy change within the field of nutrition. - Design Electronic databases were searched systematically for studies examining policymaking in public health nutrition. An interpretive synthesis was undertaken. Setting: International, national, state and local government jurisdictions within high-income, democratic countries. - Results Sixty-three studies were selected for inclusion. Numerous themes were identified explaining the barriers and enablers to policy change, all of which fell under the overarching category, ‘political will’, underpinned by a second major category, ‘public will’. Sub-themes, including pressure from industry; neoliberal ideology; use of emotions and values, and being visible were prevalent in describing links between public will, political will and policy change. - Conclusions The frustration around lack of public policy change in nutrition frequently stems from a belief that policymaking is a rational process in which evidence is used to assess the relative costs and benefits of options. The findings from this review confirm that evidence is only one component of influencing policy change. For policy change to occur there needs to be the political will, and often the public will, for the proposed policy problem and solution. This review presents a suite of enablers which can assist health professionals to influence political and public will in future advocacy efforts.