1,292 research outputs found
The moduli space of bilevel-6 abelian surfaces
The moduli space of abelian surfaces with polarisation of type (1,6) and a
bilevel structure has positive Kodaira dimension. By contrast, Mukai has shown
that the moduli space of bilevel-t abelian sufaces is rational for t=2,3,4,5.Comment: 9 pages, plain TeX. Results improved and extended: an error correcte
Improvement in plasma illumination properties of ultrananocrystalline diamond films by grain boundary engineering
[[abstract]]Microstructural evolution of ultrananocrystalline diamond (UNCD) films as a function of substrate temperature (TS) and/or by introducing H2 in Ar/CH4 plasma is investigated. Variation of the sp 2 and sp 3 carbon content is analyzed using UV-Raman and near-edge X-ray absorption fine structure spectra. Morphological and microstructural studies confirm that films deposited using Ar/CH4 plasma at low TS consist of a random distribution of spherically shaped ultra-nano diamond grains with distinct sp 2-bonded grain boundaries, which are attributed to the adherence of CH radicals to the nano-sized diamond clusters. By increasing TS, adhering efficiency of CH radicals to the diamond lattice drops and trans-polyacetylene (t-PA) encapsulating the nano-sized diamond grains break, whereas the addition of 1.5% H2 in Ar/CH4 plasma at low TS induces atomic hydrogen that preferentially etches out the t-PA attached to ultra-nano diamond grains. Both cases make the sp 3-diamond phase less passivated. This leads to C2 radicals attaching to the diamond lattice promoting elongated clustered grains along with a complicated defect structure. Such a grain growth model is highly correlated to explain the technologically important functional property, namely, plasma illumination (PI) of UNCD films. Superior PI properties, viz. low threshold field of 0.21 V/μm with a high PI current density of 4.10 mA/cm2 (at an applied field of 0.25 V/μm) and high γ-coefficient (0.2604) are observed for the UNCD films possessing ultra-nano grains with a large fraction of grain boundary phases. The grain boundary component consists of a large amount of sp 2-carbon phases that possibly form interconnected paths for facilitating the transport of electrons and the electron field emission process that markedly enhance PI properties.[[notice]]補正完畢[[booktype]]紙本[[booktype]]電子
Leadership development in a faith-based non-profit organisation using a relational leadership model: A case study
This paper describes a case study of a Leadership Development Program (LDP) which has been developed and conducted at a large faith-based non-profit organization providing aged and community care in Australia. Walter Wright's Relational Leadership model which used insights from Jude, Philemon and Colossians was adopted by the organization. Started as a pilot in 2003 the LDP was implemented in 2007 and has been run regularly since then. The LDP was systematically evaluated by an independent researcher recently. The evaluation concluded that the program has been effective and recommended that it continue with some minor modifications. The organization in which this program was developed is a partner in an Australian Research Council (ARC) linkage grant started in 2010 between three universities and two faith-based non-profit organizations providing aged care and community care. This paper has been written by four researchers involved in the linkage grant. Four interviews on participants in the LDP were conducted by the authors to evaluate the effectiveness of the leadership program in order to prepare this paper. The study was carried out to clarify the research aim for the principal author (who is a PhD student in the ARC grant) by trying to understand what the LDP program was aiming to achieve and to be presented at the Spirituality at Work conference at the University of Arkansas
Closing the loop: A systems thinking led sustainable sanitation project in Australia
This paper will explain a research project being carried out in Sydney, Australia at the University of Technology Sydney (UTS) highlighting the systems thinking principles and action research methodology being adopted in this project. UTS is set to participate in an Australia-first research project, led by the Institute of Sustainable Futures (ISF), exploring the use of innovative urine diverting toilets in an institutional setting. A UTS Challenge Grant (an internal grant scheme to promote innovative collaborative research) has been awarded to the project which will enable safe nutrient capture and reuse from urine diverting toilets installed on campus for a trial period. The Challenge Grant has some enthusiastic industry partners including the local water utility Sydney Water; the sanitaryware manufacturer CaromaDorf; the Nursery and Garden Industry Association; government partners (NSW Department of Health, and City of Sydney) and the UTS Facilities Management Unit. Researchers from the University of Western Sydney and University of New South Wales in Australia as well as Linkoping University in Sweden are collaborators in this research
Flexible electron field emitters fabricated using conducting ultrananocrystalline diamond pyramidal microtips on polynorbornene films
[[abstract]]High performance flexible field emitters made of aligned pyramidal shaped conducting ultrananocrystalline diamond (C-UNCD) microtips on polynorbornene substrates is demonstrated. Flexible C-UNCD pyramidal microtips show a low turn-on field of 1.80 V/μm with a field enhancement factor of 4580 and a high emission current density of 5.8 mA/cm2 (at an applied field of 4.20 V/μm) with life-time stability of 210 min. Such an enhancement in the field emission is due to the presence of sp 2-graphitic sheath with a nanowire-like diamond core. This high performance flexible C-UNCD field emitter is potentially useful for the fabrication of diverse, flexible electronic devices.[[booktype]]紙本[[booktype]]電子
Enhancing electrical conductivity and electron field emission properties of ultrananocrystalline diamond films by copper ion implantation and annealing
[[abstract]]Copper ion implantation and subsequent annealing at 600 °C achieved high electrical conductivity of 95.0 (Ωcm)−1 for ultrananocrystalline diamond (UNCD) films with carrier concentration of 2.8 × 1018 cm−2 and mobility of 6.8 × 102 cm2/V s. Transmission electron microscopy examinations reveal that the implanted Cu ions first formed Cu nanoclusters in UNCD films, which induced the formation of nanographitic grain boundary phases during annealing process. From current imaging tunneling spectroscopy and local current-voltage curves of scanning tunneling spectroscopic measurements, it is observed that the electrons are dominantly emitted from the grain boundaries. Consequently, the nanographitic phases presence in the grain boundaries formed conduction channels for efficient electron transport, ensuing in excellent electron field emission (EFE) properties for copper ion implanted/annealed UNCD films with low turn-on field of 4.80 V/μm and high EFE current density of 3.60 mA/cm2 at an applied field of 8.0 V/μm.[[booktype]]紙本[[booktype]]電子
Gold ion implantation induced high conductivity and enhanced electron field emission properties in ultrananocrystalline diamond films
[[abstract]]We report high conductivity of 185 (Ω cm)−1 and superior electron field emission (EFE) properties, viz. low turn-on field of 4.88 V/μm with high EFE current density of 6.52 mA/cm2 at an applied field of 8.0 V/μm in ultrananocrystalline diamond (UNCD) films due to gold ion implantation. Transmission electron microscopy examinations reveal the presence of Au nanoparticles in films, which result in the induction of nanographitic phases in grain boundaries, forming conduction channels for electron transport. Highly conducting Au ion implanted UNCD films overwhelms that of nitrogen doped ones and will create a remarkable impact to diamond-based electronics.[[incitationindex]]SCI[[booktype]]紙本[[booktype]]電子
High stability electron field emitters made of nanocrystalline diamond coated carbon nanotubes
[[abstract]]We report enhanced life-time stability for the electron field emitters prepared by coating nanocrystalline diamond (NCD) on carbon nanotubes (CNTs). Upon overcoming the problem of poor stability in CNTs, the NCD-CNTs exhibit excellent life-time stability of 250 min tested at different applied voltages of 600 and 900 V. In contrast, the life-time stability of CNTs is only 33 min even at relatively low voltage of 360 V and starts arcing at 400 V. Hence, the NCD-CNTs with improved life-time stability have great potential for the applications as cathodes in flat panel displays and microplasma display devices.[[booktype]]紙本[[booktype]]電子
Method to increase the toughness of aluminum-lithium alloys at cryogenic temperatures
A method to increase the toughness of the aluminum-lithium alloy C458 and similar alloys at cryogenic temperatures above their room temperature toughness is provided. Increasing the cryogenic toughness of the aluminum-lithium alloy C458 allows the use of alloy C458 for cryogenic tanks, for example for launch vehicles in the aerospace industry. A two-step aging treatment for alloy C458 is provided. A specific set of times and temperatures to age the aluminum-lithium alloy C458 to T8 temper is disclosed that results in a higher toughness at cryogenic temperatures compared to room temperature. The disclosed two-step aging treatment for alloy 458 can be easily practiced in the manufacturing process, does not involve impractical heating rates or durations, and does not degrade other material properties
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