Hexagon platinum Schottky contact with ZnO thin film for hydrogen sensing

This paper reports on the study of the effect on adding total peripheries and sharp edges to the Schottky contact as a hydrogen sensor. Schottky contact was successfully designed and fabricated as hexagon-shape. The contact was integrated together with zinc oxide thin film and tested towards 1% hydrogen gas. Simulations of the design were conducted using COMSOL Multiphysics to observe the electric field characteristic at the contact layer. The simulation results show higher electric field induced at sharp edges with 4.18×104 V/m. Current-voltage characteristic shows 0.27 V voltage shift at 40 μA biased current.

Advantages of exploiting projection structure for segmenting dense 3D point clouds

Timely and comprehensive scene segmentation is often a critical step for many high level mobile robotic tasks. This paper examines a projected area based neighbourhood lookup approach with the motivation towards faster unsupervised segmentation of dense 3D point clouds. The proposed algorithm exploits the projection geometry of a depth camera to find nearest neighbours which is time independent of the input data size. Points near depth discontinuations are also detected to reinforce object boundaries in the clustering process. The search method presented is evaluated using both indoor and outdoor dense depth images and demonstrates significant improvements in speed and precision compared to the commonly used Fast library for approximate nearest neighbour (FLANN) [Muja and Lowe, 2009].

Making orchids – Gardening an intersex experience on videotape [In German - Orchideen Züchten. Eine inter Erfahrung auf Film]

In 2004, my thirtieth year of life, I began to develop and produce a documentary about the lived experience of being intersex. At the time, I didn’t ever expect the film would be autobiographical in nature. I’d known I was intersex since I was 17, and aware of my difference for many years prior, and I’d been making and presenting documentaries for almost as long, yet the idea to expose myself so publicly was frightening to me. However, I realised I couldn’t expect others to step in front of the lens when I didn’t have the courage to do so myself. The final result was Orchids: My Intersex Adventure, which maps my intersex journey from shame, stigma and secrecy to self‐acceptance. The film has now been broadcast on television sets around the world. It has also won many awards and appeared in numerous film festivals....

QUT Architecture Film Studio (Aus)

Research Statement: An urban film produced by Luke Harrison Mitchell Benham, Sharlene Anderson, Tristan Clark. RIVE NOIR explores the film noir tradition, shot on location in a dark urban space between high-rises and the river, sheltered by a highway. With an original score and striking cinematography, Rive Noir radically transforms the abandoned river’s edge through the production of an amplified reality ordinarily unseen in the Northbank. The work produced under my supervision was selected to appear in the Expanded Architecture Research Group’s International Architecture Film Festival and Panel Discussion in Sydney: The University of Sydney and Carriageworks Performance Space, 06 November 2011. QUT School of Design research submission was selected alongside exhibits by AA School of Architecture, London; The Bartlett School of Architecture, London; University of The Arts, London; Arrhaus School of Architecture, Denmark; Dublin as a Cinematic City, Ireland; Design Lab Screen Studio, Australia; and Sona Cinecity, The University of Melbourne. The exhibit included not only the screening of the film but the design project that derived from and extended the aesthetics of the urban film. The urban proposal and architectural intervention that followed the film was subsequently published in the Brisbane Times, after the urban proposal won first place in The Future of Brisbane architecture competition, which demonstrates the impact of the research project as a whole. EXPANDED ARCHITECTURE 2011 - 6th November Architecture Film Night + Panel Discussion @ Performance Space CarriageWorks was Sydney's first International Architectural Film Festival. With over 40 architectural films by local and international artists, film makers and architects. It was followed by Panel Discussion of esteemed academics and artists working in the field of architectural film.

The Brisbane Northbank Urban Film Studio : screening of shortlisted films

Research Statement: In this research project film groups of 4-5 students under my direction produced a 3-5 minute urban film that explored the Brisbane Northbank, and which would become the basis for an urban proposal and design of a small film studio for independent filmmakers in the site. The theoretical premise was that a film studio does not simply produce movies, it creates urban effects all around it and acts as a vortex of cultural activity and social life. For this modest facility where the cinema goes out into the street, the city itself becomes the studio. Students were called to observe the historical problematics of technique, image and effect that arise in the cinema, and to apply these to their own urban-film practice. A panel of judges working in film and architecture shortlisted the 12 best films in 2010 and a major public film screening event took place at the Tribal Cinema. The Shortlisted films today form a permanent "exhibit" in YouTube. The research project was funded by the Queensland University of Technology, School of Design and received accolades from film faculty in the Creative Industries Faculty. The diverse body of work that emanated from the screening contributed a unique analysis of the Northbank to Brisbane.

Tuning the surface structure of nitrogen-doped TiO2Nanofibres : an effective method to rnhance photocatalytic activities of visible-light-driven green synthesis and degradation

Nitrogen-doped TiO2 nanofibres of anatase and TiO2(B) phases were synthesised by a reaction between titanate nanofibres of a layered structure and gaseous NH3 at 400–700 °C, following a different mechanism than that for the direct nitrogen doping from TiO2. The surface of the N-doped TiO2 nanofibres can be tuned by facial calcination in air to remove the surface-bonded N species, whereas the core remains N doped. N-Doped TiO2 nanofibres, only after calcination in air, became effective photocatalysts for the decomposition of sulforhodamine B under visible-light irradiation. The surface-oxidised surface layer was proven to be very effective for organic molecule adsorption, and the activation of oxygen molecules, whereas the remaining N-doped interior of the fibres strongly absorbed visible light, resulting in the generation of electrons and holes. The N-doped nanofibres were also used as supports of gold nanoparticle (Au NP) photocatalysts for visible-light-driven hydroamination of phenylacetylene with aniline. Phenylacetylene was activated on the N-doped surface of the nanofibres and aniline on the Au NPs. The Au NPs adsorbed on N-doped TiO2(B) nanofibres exhibited much better conversion (80 % of phenylacetylene) than when adsorbed on undoped fibres (46 %) at 40 °C and 95 % of the product is the desired imine. The surface N species can prevent the adsorption of O2 that is unfavourable for the hydroamination reaction, and thus, improve the photocatalytic activity. Removal of the surface N species resulted in a sharp decrease of the photocatalytic activity. These photocatalysts are feasible for practical applications, because they can be easily dispersed into solution and separated from a liquid by filtration, sedimentation or centrifugation due to their fibril morphology.

Performance of buried tunnels subjected to surface blast incorporating fluid structure interaction

This paper uses finite element techniques to investigate the performance of buried tunnels subjected to surface blasts incorporating fully coupled Fluid Structure Interaction and appropriate material models which simulate strain rate effects. Modelling techniques are first validated against existing experimental results and then used to treat the blast induced shock wave propagation and tunnel response in dry and saturated sands. Results show that the tunnel buried in saturated sand responds earlier than that in dry sand. Tunnel deformations decrease with distance from explosive in both sands, as expected. In the vicinity of the explosive, the tunnel buried in saturated sand suffered permanent deformation in both axial and circumferential directions, whereas the tunnel buried in dry sand recovered from most of the axial deformation. Overall, response of the tunnel in saturated sand is more severe for a given blast event and shows the detrimental effect of pore water on the blast response of buried tunnels. The validated modelling techniques developed in this paper can be used to investigate the blast response of tunnels buried in dry and saturated sands.

High performance electrochromic devices based on anodized nanoporous Nb2O5

Despite the predictions, the true potential of Nb2O5 for electrochromic applications has yet to be fully realized. In this work, three-dimensional (3D) compact and well-ordered nanoporous Nb2O5 films are synthesized by the electrochemical anodization of niobium thin films. These films are formed using RF sputtering and then anodized in an electrolyte containing ethylene glycol, ammonium fluoride, and small water content (4%) at 50 °C which resulted in low embedded impurities within the structure. Characterization of the anodized films shows that a highly crystalline orthorhombic phase of Nb2O5 is obtained after annealing at 450 °C. The 3D structure provides a template consisting of a large concentration of active sites for ion intercalation, while also ensuring low scattering directional paths for electrons. These features enhance the coloration efficiency to 47.0 cm2 C?1 (at 550 nm) for a 500 nm thick film upon Li+ ion intercalation. Additionally, the Nb2O5 electrochromic device shows a high bleached state transparency and large optical modulation.

Comparison of functionals for metal hexaboride band structure calculations

Density functional calculations of the electronic band structure for superconducting and semi-conducting metal hexaborides are compared using a consistent suite of assumptions and with emphasis on the physical implications of computed models. Spin polarization enhances mathematical accuracy of the functional approximations and adds significant physical meaning to model interpretation. For YB6 and LaB6, differences in alpha and beta projections occur near the Fermi energy. These differences are pronounced for superconducting hexaborides but do not occur for other metal hexaborides.

A comparison of surface doses for very small field size x-ray beams : Monte Carlo calculations and radiochromic film measurements

Stereotactic radiosurgery treatments involve the delivery of very high doses for a small number of fractions. To date, there is limited data in terms of the skin dose for the very small field sizes used in these treatments. In this work, we determine relative surface doses for small size circular collimators as used in stereotactic radiosurgery treatments. Monte Carlo calculations were performed using the BEAMnrc code with a model of the Novalis 15 Trilogy linear accelerator and the BrainLab circular collimators. The surface doses were calculated at the ICRU skin dose depth of 70 m all using the 6 MV SRS x-ray beam. The calculated surface doses varied between 15 – 12% with decreasing values as the field size increased from 4 to 30 mm. In comparison, surface doses were measured using Gafchromic EBT3 film positioned at the surface of a Virtual Water phantom. The absolute agreement between calculated and measured surface doses was better than 2.5% which is well within the 20 uncertainties of the Monte Carlo calculations and the film measurements. Based on these results, we have shown that the Gafchromic EBT3 film is suitable for surface dose estimates in very small size fields as used in SRS.

The molecular structure of the vanadate mineral mottramite [PbCu(VO4)(OH)] from Tsumeb, Namibia – a vibrational spectroscopic study

We have studied a mineral sample of mottramite PbCu(VO4)(OH) from Tsumeb, Namibia using a combination of scanning electron microscopy with EDX, Raman and infrared spectroscopy. Chemical analysis shows principally the elements V, Pb and Cu. Ca occurs as partial substitution of Pb as well as P and As in substitution to V. Minor amounts of Si and Cr were also observed. The Raman band of mottramite at 829 cm-1, is assigned to the ν1 symmetric (VO-4) ) stretching mode. The complexity of the spectra is attributed to the chemical composition of the Tsumeb mottramite. The ν3 antisymmetric vibrational mode of mottramite is observed as very low intensity bands at 716 and 747 cm-1. The series of Raman bands at 411, 439, 451 cm-1 and probably also the band at 500 cm-1 are assigned to the (VO-4) ν2 bending mode. The series of Raman bands at 293, 333 and 366 cm-1 are attributed to the (VO-4) ) ν4 bending modes. The ν3, ν3 and ν4 regions are complex for both minerals and this is attributed to symmetry reduction of the vanadate unit from Td to Cs.

The molecular structure of the borate mineral rhodizite (K, Cs)Al4Be4(B, Be)12O28 – A vibrational spectroscopic study

We have studied the borate mineral rhodizite (K, Cs)Al4Be4(B, Be)12O28 using a combination of DEM with EDX and vibrational spectroscopic techniques. The mineral occurs as colorless, gray, yellow to white crystals in the triclinic crystal system. The studied sample is from the Antandrokomby Mine, Sahatany valley, Madagascar. The mineral is prized as a semi-precious jewel. Semi-quantitative chemical composition shows a Al, Ca, borate with minor amounts of K, Mg and Cs. The mineral has a characteristic borate Raman spectrum and bands are assigned to the stretching and bending modes of B, Be and Al. No Raman bands in the OH stretching region were observed.

The molecular structure of the phosphate mineral beraunite Fe2+Fe⅗+(PO4)4(OH)5⋅4H2O– A vibrational spectroscopic study

The mineral beraunite from Boca Rica pegmatite in Minas Gerais with theoretical formula Fe2+Fe5 3+(PO4)4(OH)5⋅4H2O has been studied using a combination of electron microscopy with EDX and vibrational spectroscopic techniques. Raman spectroscopy identifies an intense band at 990 cm-1 and 1011 cm-1. These bands are attributed to the PO4 3- v, symmetric stretching mode. The m3 antisymmetric stretching modes are observed by a large number of Raman bands. The Raman bands at 1034, 1051, 1058, 1069 and 1084 together with the Raman bands at 1098, 1116, 1133, 1155 and 1174 cm-1 are assigned to the m3 antisymmetric stretching vibrations of PO4 3- and the HOPO3 2- units. The observation of these multiple Raman bands in the symmetric and antisymmetric stretching region gives credence to the concept that both phosphate and hydrogen phosphate units exist in the structure of beraunite. The series of Raman bands at 567, 582,601, 644, 661, 673, and 687 cm-1 are assigned to the PO4 3- v2 bending modes. The series of Raman bands at 437, 468, 478, 491, 503 cm-1 are attributed to the PO4 3- and OPO3 2- v4 bending modes. No Raman bands of beraunite which could be attributed to the hydroxyl stretching unit were observed. Infrared bands at 3511 and 3359 cm-1 are ascribed to the OH stretching vibration of the OH units. Very broad bands at 3022 and 3299 cm-1 are attributed to the OH stretching vibrations of water. Vibrational spectroscopy offers insights into the molecular structure of the phosphate mineral beraunite.

Solid-state structure of some substituted hexahydro-1,4:5,8-diepoxy­naphthalenes

The structure of several carboxy-substituted hexahydro-1,4:5,8-diepoxynaphthalenes have been solved with X-ray crystallography, in some cases confirming previously contentious structures. The compounds of interest are constructed in efficient one-step 2 × [4+2] cycloaddition reactions from furan and acetylene carboxylate derivatives.