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2013

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Articles 8341 - 8370 of 11462

Full-Text Articles in Physical Sciences and Mathematics

Effects Of Different Geomagnetic Storm Drivers On The Ring Current: Crcm Results, W. Douglas Cramer, Niescja E. Turner, M. C. Fok, N. Yu Buzulukova Jan 2013

Effects Of Different Geomagnetic Storm Drivers On The Ring Current: Crcm Results, W. Douglas Cramer, Niescja E. Turner, M. C. Fok, N. Yu Buzulukova

Aerospace, Physics, and Space Science Faculty Publications

The storm-time magnetic disturbance at the Earth’s equator, as commonly measured by the Dst index, is induced by currents in the near-Earth magnetosphere. The ring current is generally considered the most important contributor, but other magnetospheric currents have also been found to have significant effects. Of the two main types of solar geomagnetic storm drivers, Coronal Mass Ejections (CMEs) tend to have a much greater impact on Dst than Corotating Interaction Regions (CIRs). Ring current models have been found to underestimate Dst, particularly during storms driven by CIRs. One possible explanation is that the models neglect to handle some aspect …

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Impact Of Programming Features On Code Readability, Y. Tashtoush, Z. Odat, Izzat M. Alsmadi, M. Yatim Jan 2013

Impact Of Programming Features On Code Readability, Y. Tashtoush, Z. Odat, Izzat M. Alsmadi, M. Yatim

Computer Science Faculty Publications

Readability is one important quality attributes for software source codes. Readability has also significant relation or impact with other quality attributes such as: reusability, maintainability, reliability, complexity, and portability metrics. This research develops a novel approach called Impact of Programming Features on Code Readability (IPFCR), to examine the influence of various programming features and the effect of these features on code readability. A code Readability Tool (CRT) is developed to evaluate the IPFCR readability features or attributes. In order to assess the level if impact that each one of the 25 proposed readability features may have, positively or negatively on …

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Efficient Assessment And Evaluation For Websites Vulnerabilities Using Snort, M. Dabbour, Izzat M. Alsmadi, E. Alsukhni Jan 2013

Efficient Assessment And Evaluation For Websites Vulnerabilities Using Snort, M. Dabbour, Izzat M. Alsmadi, E. Alsukhni

Computer Science Faculty Publications

An endless number of methods or ways exists to access illegally a web server or a website. The task of defending a system (e.g. network, server, website, etc.) is complex and challenging. SNORT is one of the popular open source tools that can be used to detect and possibly prevent illegal access and attacks for networks and websites. However, this largely depends on the way SNORT rules are designed and implemented. In this paper, we investigated in details several examples of SNORT rules and how they can be tuned to improve websites protection. We demonstrated practical methods to design and …

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Call Graph Based Metrics To Evaluate Software Design Quality, H. Abandah, Izzat M. Alsmadi Jan 2013

Call Graph Based Metrics To Evaluate Software Design Quality, H. Abandah, Izzat M. Alsmadi

Computer Science Faculty Publications

Software defects prediction was introduced to support development and maintenance activities such as improving the software quality through finding errors or patterns of errors early in the software development process. Software defects prediction is playing the role of maintenance facilitation in terms of effort, time and more importantly the cost prediction for software maintenance and evolution activities. In this research, software call graph model is used to evaluate its ability to predict quality related attributes in developed software products. As a case study, the call graph model is generated for several applications in order to represent and reflect the degree …

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Formation Of Sprite Streamers At Subbreakdown Conditions From Ionospheric Inhomogeneities Resembling Observed Sprite Halo Structures, Burcu C. Kosar, Ningyu Liu, Hamid K. Rassoul Jan 2013

Formation Of Sprite Streamers At Subbreakdown Conditions From Ionospheric Inhomogeneities Resembling Observed Sprite Halo Structures, Burcu C. Kosar, Ningyu Liu, Hamid K. Rassoul

Aerospace, Physics, and Space Science Faculty Publications

Modeling results of sprite streamer formation from large ionospheric inhomogeneities or patches (several tens to hundreds of meter wide) indicate that positive streamers can be initiated at subbreakdown conditions from the inhomogeneities with a density comparable to sprite halo densities. For spherical patches with a given radius, the minimum density required for streamer initiation decreases with increasing ambient field. For a given density, the minimum size of the inhomogeneity decreases with increasing ambient field. The modeling results on the associated optical emissions show that a luminous spherical-like cap appears around the lower tip of the ionization patch before streamer initiation, …

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The Angular Distribution Of Energetic Electron And X-Ray Emissions From Triggered Lightning Leaders, M. M. Schaal, Joseph R. Dwyer, Hamid K. Rassoul, Jonathan David Hill, Douglas M. Jordan, Martin A. Uman Jan 2013

The Angular Distribution Of Energetic Electron And X-Ray Emissions From Triggered Lightning Leaders, M. M. Schaal, Joseph R. Dwyer, Hamid K. Rassoul, Jonathan David Hill, Douglas M. Jordan, Martin A. Uman

Aerospace, Physics, and Space Science Faculty Publications

We investigate individual X-ray bursts from lightning leaders to determine if energetic electrons at the source (and hence X-rays) are emitted isotropically or with some degree of anisotropy. This study was motivated by the work of Saleh et al. (2009), which found the falloff of X-rays in concentric radial annuli, covering all azimuthal directions in each annulus, from the lightning channel to be most consistent with an isotropic electron source. Here we perform a statistical analysis of angular and spatial distributions of X-rays measured by up to 21 NaI/PMT detectors at the International Center for Lightning Research and Testing site …

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Radio Emissions From Terrestrial Gamma-Ray Flashes, Joseph R. Dwyer, Steven A. Cummer Jan 2013

Radio Emissions From Terrestrial Gamma-Ray Flashes, Joseph R. Dwyer, Steven A. Cummer

Aerospace, Physics, and Space Science Faculty Publications

The theory of radio frequency (RF) emissions by terrestrial gamma-ray flashes (TGFs) is developed. These radio emissions, which are separate from the emission caused by lightning, are produced by the electric currents generated by runaway electrons and resulting low-energy electrons and ions. It is found from theory that the radio frequency pulses produced by TGFs are large enough to measure. Features of these signals depend strongly on certain aspects of the runaway acceleration process and so should provide additional information about the source mechanism(s) of this interesting atmospheric phenomenon. The RF emissions from several TGF models are calculated and compared …

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Radio Signals From Electron Beams In Terrestrial Gamma Ray Flashes, Valerie Connaughton, Joseph R. Dwyer, Eric Cramer Jan 2013

Radio Signals From Electron Beams In Terrestrial Gamma Ray Flashes, Valerie Connaughton, Joseph R. Dwyer, Eric Cramer

Aerospace, Physics, and Space Science Faculty Publications

We show that the rate of association between terrestrial gamma ray flashes (TGFs) observed by the Fermi gamma ray burst monitor and VLF discharges detected by the World Wide Lightning Location Network (WWLLN) depends strongly on the duration of the TGF, with the shortest TGFs having associated WWLLN events over 50% of the time, and the longest TGFs showing a less than 10% match rate. This correlation is stronger if one excludes the WWLLN discharges that are not simultaneous (within 200 ms) with the TGF. We infer that the simultaneous VLF discharges are from the relativistic electron avalanches that are …

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Modeling The X-Ray Light Curves Of Cygnus X-3 Possible Role Of The Jet, Osmi Vilhu, Diana Carina Hannikainen Jan 2013

Modeling The X-Ray Light Curves Of Cygnus X-3 Possible Role Of The Jet, Osmi Vilhu, Diana Carina Hannikainen

Aerospace, Physics, and Space Science Faculty Publications

Context. We address the physics behind the soft X-ray light curve asymmetries in Cygnus X-3, a well-known microquasar. Aims. Observable eff ects of the jet close to the line-of-sight were investigated and interpreted within the frame of light curve physics. Methods. The path of a hypothetical imprint of the jet, advected by theWolf-Rayet-wind, was computed and its crossing with the line-of-sight during the binary orbit determined. We explored the possibility that physically this “imprint” is a formation of dense clumps triggered by jet bow shocks in the wind (“clumpy trail”). Models for X-ray continuum and emission line light curves were …

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The 72-H Webt Microvariability Observation Of Blazar S5 0716+714 In 2009, G Bhatta, Stéphane Vennes Jan 2013

The 72-H Webt Microvariability Observation Of Blazar S5 0716+714 In 2009, G Bhatta, Stéphane Vennes

Aerospace, Physics, and Space Science Faculty Publications

Context. The international Whole Earth Blazar Telescope (WEBT) consortium planned and carried out three days of intensive micro-variability observations of S5 0716+714 from February 22, 2009 to February 25, 2009. This object was chosen due to its bright apparent magnitude range, its high declination, and its very large duty cycle for micro-variations. Aims. We report here on the long continuous optical micro-variability light curve of 0716+714 obtained during the multi-site observing campaign during which the Blazar showed almost constant variability over a 0.5 mag range. The resulting light curve is presented here for the first time. Observations from participating observatories …

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Using Existing Programs As Vehicles To Disseminate Knowledge, Provide Opportunities For Scientists To Assist Educators, And To Engage Students In Using Real Data., Steven Smith, Kristin Wegner, Benjamin D. Branch, Bridget Miller, Darrell G. Schulze, Ann M. Bessenbacher Jan 2013

Using Existing Programs As Vehicles To Disseminate Knowledge, Provide Opportunities For Scientists To Assist Educators, And To Engage Students In Using Real Data., Steven Smith, Kristin Wegner, Benjamin D. Branch, Bridget Miller, Darrell G. Schulze, Ann M. Bessenbacher

Libraries Faculty and Staff Presentations

Many national and statewide programs throughout the K-12 science education environment teach students about science in a hands-on format, including programs such as Global Learning and Observations to Benefit the Environment (GLOBE), Project Learning Tree (PLT), Project Wild, Project Wet, and Hoosier River Watch. Partnering with one or more of these well-known programs can provide many benefits to both the scientists involved in disseminating research and the K-12 educators. Scientists potentially benefit by broader dissemination of their research by providing content enrichment for educators. Educators benefit by gaining understanding in content, becoming more confident in teaching the concept, and increasing …

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A Justification For Semantic Training In Data Curation Frameworks Development, Xiaogang Ma, Benjamin D. Branch, Kristin Wegner Jan 2013

A Justification For Semantic Training In Data Curation Frameworks Development, Xiaogang Ma, Benjamin D. Branch, Kristin Wegner

Libraries Faculty and Staff Presentations

In the complex data curation activities involving proper data access, data use optimization and data rescue, opportunities exist where underlying skills in semantics may play a crucial role in data curation professionals ranging from data scientists, to informaticists, to librarians. Here, We provide a conceptualization of semantics use in the education data curation framework (EDCF) (Fig. 1) [1] under development by Purdue University and endorsed by the GLOBE program [2] for further development and application. Our work shows that a comprehensive data science training includes both spatial and non-spatial data, where both categories are promoted by standard efforts of organizations …

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High-Temperature Piezoelectric Sensing, Xiaoning Jiang, Kyungrim Kim, Shujun Zhang, Joseph A. Johnson, Giovanni Salazar Jan 2013

High-Temperature Piezoelectric Sensing, Xiaoning Jiang, Kyungrim Kim, Shujun Zhang, Joseph A. Johnson, Giovanni Salazar

Australian Institute for Innovative Materials - Papers

Piezoelectric sensing is of increasing interest for high-temperature applications in aerospace, automotive, power plants and material processing due to its low cost, compact sensor size and simple signal conditioning, in comparison with other high-temperature sensing techniques. This paper presented an overview of high-temperature piezoelectric sensing techniques. Firstly, different types of high-temperature piezoelectric single crystals, electrode materials, and their pros and cons are discussed. Secondly, recent work on high-temperature piezoelectric sensors including accelerometer, surface acoustic wave sensor, ultrasound transducer, acoustic emission sensor, gas sensor, and pressure sensor for temperatures up to 1,250 °C were reviewed. Finally, discussions of existing challenges and …

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1-3 Piezoelectric Composites For High-Temperature Transducer Applications, Lili Li, Shujun Zhang, Zhuo Xu, Fei Wen, Xuecang Geng, Hyeong Jae Lee, Thomas R. Shrout Jan 2013

1-3 Piezoelectric Composites For High-Temperature Transducer Applications, Lili Li, Shujun Zhang, Zhuo Xu, Fei Wen, Xuecang Geng, Hyeong Jae Lee, Thomas R. Shrout

Australian Institute for Innovative Materials - Papers

High-temperature Pb(Zr,Ti)O3/epoxy 1-3 composites were fabricated using the dice and fill method. The epoxy filler was modified with glass spheres in order to improve the thermal reliability of the composites at elevated temperatures. Temperature-dependent dielectric and electromechanical properties of the composites were measured after ageing at 250 °C with different dwelling times. Obvious cracks were observed and the electrodes were damaged in the composite with unmodified epoxy after 200 h, leading to the failure of the composite. In contrast, composites with >12 vol% glass sphere loaded epoxies were found to exhibit minimal electrical property variation after ageing for 500 h, …

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Morphology-Controllable 1d-3d Nanostructured Tio2 Bilayer Photoanodes For Dye-Sensitized Solar Cells, Ziqi Sun, Jung Ho Kim, Yue Zhao, Darren Attard, S X. Dou Jan 2013

Morphology-Controllable 1d-3d Nanostructured Tio2 Bilayer Photoanodes For Dye-Sensitized Solar Cells, Ziqi Sun, Jung Ho Kim, Yue Zhao, Darren Attard, S X. Dou

Australian Institute for Innovative Materials - Papers

Morphology-controlled bilayer TiO2 nanostructures consisting of one-dimensional (1D) nanowire bottom arrays and a three-dimensional (3D) dendritic microsphere top layer were synthesized via a one-step hydrothermal method. These novel 1D-3D bilayer photoanodes demonstrated the highest energy conversion efficiency of 7.2% for rutile TiO2 dye-sensitized solar cells to date, with TiCl4 post-treatment.

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Thermolysis And Solid State Nmr Studies Of Nab3h8, Nh3b3h7, And Nh4b3h 8, Zhenguo Huang, Mitch Eagles, Spencer Porter, Eric G. Sorte, Beau Billet, Robert L. Corey, Mark S. Conradi, Ji-Cheng Zhao Jan 2013

Thermolysis And Solid State Nmr Studies Of Nab3h8, Nh3b3h7, And Nh4b3h 8, Zhenguo Huang, Mitch Eagles, Spencer Porter, Eric G. Sorte, Beau Billet, Robert L. Corey, Mark S. Conradi, Ji-Cheng Zhao

Australian Institute for Innovative Materials - Papers

In an effort to broaden the search for high-capacity hydrogen storage materials, three triborane compounds, NaB3H8, NH 3B3H7, and NH4B3H 8, were studied. In addition to hydrogen, thermal decomposition also releases volatile boranes, and the relative amounts and species depend on the cations (Na+, NH4 +) and the Lewis base (NH 3). Static-sample hydrogen NMR is used to probe molecular motion in the three solids. In each case, the line width decreases from low temperatures to room temperature in accordance with a model of isotropic or nearly isotropic reorientations. Such motions also explain a deep minimum in the relaxation time …

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Nanosecond Voltage Pulses From Dendritic Flux Avalanches In Superconducting Nbn Films, P Mikheenko, A J. Qviller, J I. Vestgarden, S Chaudhuri, I J. Maasilta, Y M. Galperin, Tom H. Johansen Jan 2013

Nanosecond Voltage Pulses From Dendritic Flux Avalanches In Superconducting Nbn Films, P Mikheenko, A J. Qviller, J I. Vestgarden, S Chaudhuri, I J. Maasilta, Y M. Galperin, Tom H. Johansen

Australian Institute for Innovative Materials - Papers

Combined voltage and magneto-optical study of magnetic flux flow in superconducting NbN films is reported. The nanosecond-scale voltage pulses appearing during thermomagnetic avalanches have been recorded in films partially coated by a metal layer. Simultaneous magneto-optical imaging and voltage measurements allowed the pulses to be associated with individual flux branches penetrating the superconductor below the metal coating. From detailed characteristics of pulse and flux branches, the electrical field in the superconductor is found to be in the range of 5-50 kV/m, while the propagation speed of the avalanche during its final stage is found to be close to 5 km/s.

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Orbital Structure Of Fetio3 Ilmenite Investigated With Polarization-Dependent X-Ray Absorption Spectroscopy And Band Structure Calculations, S W. Chen, M J. Huang, P A. Lin, H T. Jeng, J M. Lee, S C. Haw, S A. Chen, H J. Lin, K T. Lu, Dapeng Chen, S X. Dou, X L. Wang, J M. Chen Jan 2013

Orbital Structure Of Fetio3 Ilmenite Investigated With Polarization-Dependent X-Ray Absorption Spectroscopy And Band Structure Calculations, S W. Chen, M J. Huang, P A. Lin, H T. Jeng, J M. Lee, S C. Haw, S A. Chen, H J. Lin, K T. Lu, Dapeng Chen, S X. Dou, X L. Wang, J M. Chen

Australian Institute for Innovative Materials - Papers

We explored the orbital structure of FeTiO3 with polarization-dependent x-ray absorption spectra complemented with electronic structure calculations. The electronic structure, near the bottom of conduction band, is composed of O 2p and Ti 3d orbitals. Ti 3d/4p hybridization dominantly lies on the ab plane. The highly delocalized Ti 4p orbital might hybridize with O 2p orbital and even extend to the next-neighbor Fe atom whereby establishing a linear orbital combination of Ti-O-Fe. A clear picture of the orbital construction in FeTiO3 will help to elucidate the paths of pressure-induced charge transfer and other physical or magnetic characteristics.

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Correlation Between Structural Parameters And The Magnetocaloric Effect In Epitaxial La0.8ca0.2mno3/Laalo3 Thin Film, J C. Debnath, J H. Kim, Y Heo, A M. Strydom, S X. Dou Jan 2013

Correlation Between Structural Parameters And The Magnetocaloric Effect In Epitaxial La0.8ca0.2mno3/Laalo3 Thin Film, J C. Debnath, J H. Kim, Y Heo, A M. Strydom, S X. Dou

Australian Institute for Innovative Materials - Papers

An epitaxial La0.8Ca0.2MnO3/LaAlO 3 (LCMO/LAO) thin film was fabricated using the pulsed laser deposition technique to evaluate the correlation between the crystal structure and the magnetocaloric effect. In our study, the LCMO film was 200 nm in thickness and appeared to have a strong out-of plane texture. We found that each column in the LCMO thin film layer is a domain which has a different ordering direction. These microscopic feature results in anisotropic properties of magnetization, entropy, and relative cooling power. The film exhibited a paramagnetic-to-ferromagnetic second order phase transition at 249 K. The lack of any hysteresis loss also …

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Effect Of Sintering Temperature On The Superconducting Properties Of Graphene Doped Mgb2, K S B De Silva, X Xu, Sanjeev Gambhir, D C K Wong, W X Li, Q Y. Hu Jan 2013

Effect Of Sintering Temperature On The Superconducting Properties Of Graphene Doped Mgb2, K S B De Silva, X Xu, Sanjeev Gambhir, D C K Wong, W X Li, Q Y. Hu

Australian Institute for Innovative Materials - Papers

A comprehensive study on the effects of sintering temperature on graphene-doped MgB2 superconductor was conducted. Graphene has emerged as an effective dopant that is capable of improving the critical current density (J-{\rm c}) and flux pinning at a very low doping level, with only a slight reduction of the critical temperature (T-{\rm c}). MgB2 undoped and graphene-doped bulk samples were prepared by the in situ method and sintered within a temperature range from 650 to 950 {\circ}\hbox{C}. It is surprising to note that at the doping level of 1 at.% the sample sintered at 850 {\circ}\hbox{C} shows a J\rm c …

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Tunable Negative Permittivity Behavior And Conductor-Insulator Transition In Dual Composites Prepared By Selective Reduction Reaction, Zi-Dong Zhang, Run-Hua Fan, Zhi-Cheng Shi, Shi-Bing Pan, Ke-Lan Yan, Kang-Ning Sun, Jing-De Zhang, Xiang-Fa Liu, Xiaolin Wang, S X. Dou Jan 2013

Tunable Negative Permittivity Behavior And Conductor-Insulator Transition In Dual Composites Prepared By Selective Reduction Reaction, Zi-Dong Zhang, Run-Hua Fan, Zhi-Cheng Shi, Shi-Bing Pan, Ke-Lan Yan, Kang-Ning Sun, Jing-De Zhang, Xiang-Fa Liu, Xiaolin Wang, S X. Dou

Australian Institute for Innovative Materials - Papers

We use a selective reduction reaction to fabricate a new kind of dual composite, which has a "composite-within-a-composite" structure. Based on the different reduction behavior of Fe2O3, an Fe-rich structure (Fe-Fe3O4-Al2O3) is formed in an Al-rich structure (FeAl2O4-Al2O3). The Fe-rich structure can bring down the concentration of free electrons to reduce the energy loss, without losing its metallic behaviour at the same time. Near the percolation threshold, a conductor-insulator transition appears and the dual composites show totally different electromagnetic responses, which can be well explained by effective medium theory. By controlling the parameters of the selective reduction process, we can …

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Pegylation Of Platinum Bio-Electrodes, Zhilian Yue, Paul J. Molino, Xiao Liu, Gordon G. Wallace Jan 2013

Pegylation Of Platinum Bio-Electrodes, Zhilian Yue, Paul J. Molino, Xiao Liu, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

Controlling protein interactions at the implanted electrode interface is becoming an important strategy for the management of foreign body responses that have proven to be detrimental to the long-term performance of neural prosthesis. In this study, PEGylation was conducted on platinum bio-electrodes to render the surface protein-resistant. The PEGylated electrode was investigated using a quartz crystal microbalance-dissipation, electrochemical impedance spectroscopy and cyclic voltammetiy.

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Engineering A Multimodal Nerve Conduit For Repair Of Injured Peripheral Nerve, A F. Quigley, K J. Bulluss, I L. B Kyratzis, K Gilmore, T Mysore, K S U Schirmer, E L. Kennedy, M O'Shea, Y B. Truong, S L. Edwards, G Peeters, P Herwig, Joselito M. Razal, T E. Campbell, K N. Lowes, M J. Higgins, S E. Moulton, M A. Murphy, M J. Cook, G M. Clark, G G. Wallace, R M. I Kapsa Jan 2013

Engineering A Multimodal Nerve Conduit For Repair Of Injured Peripheral Nerve, A F. Quigley, K J. Bulluss, I L. B Kyratzis, K Gilmore, T Mysore, K S U Schirmer, E L. Kennedy, M O'Shea, Y B. Truong, S L. Edwards, G Peeters, P Herwig, Joselito M. Razal, T E. Campbell, K N. Lowes, M J. Higgins, S E. Moulton, M A. Murphy, M J. Cook, G M. Clark, G G. Wallace, R M. I Kapsa

Australian Institute for Innovative Materials - Papers

Injury to nerve tissue in the peripheral nervous system (PNS) results in long-term impairment of limb function, dysaesthesia and pain, often with associated psychological effects. Whilst minor injuries can be left to regenerate without intervention and short gaps up to 2 cm can be sutured, larger or more severe injuries commonly require autogenous nerve grafts harvested from elsewhere in the body (usually sensory nerves). Functional recovery is often suboptimal and associated with loss of sensation from the tissue innervated by the harvested nerve. The challenges that persist with nerve repair have resulted in development of nerve guides or conduits from …

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Optical Switching Of Protein Interactions On Photosensitive-Electroactive Polymers Measured By Atomic Force Microscopy, Amy Gelmi, Michele Zanoni, Michael J. Higgins, Sanjeev Gambhir, David L. Officer, Dermot Diamond, Gordon G. Wallace Jan 2013

Optical Switching Of Protein Interactions On Photosensitive-Electroactive Polymers Measured By Atomic Force Microscopy, Amy Gelmi, Michele Zanoni, Michael J. Higgins, Sanjeev Gambhir, David L. Officer, Dermot Diamond, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

The ability to switch the physico-chemical properties of conducting polymers opens up new possibilities for a range of applications. Appropriately functionalised materials can provide routes to multi-modal switching, for example, in response to light and/or electrochemical stimuli. This capability is important in the field of bionics wherein remote and temporal control of the properties of materials is becoming attractive. The ability to actuate a film via photonic stimuli is particularly interesting as it facilitates the modulation of interactions between host binding sites and potential guest molecules. In this work, we studied two different poly-terthiophenes: one was functionalised with a spiropyran …

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Covalently Linked Biocompatible Graphene/Polycaprolactone Composites For Tissue Engineering, Sepidar Sayyar, Eoin Murray, Brianna C. Thompson, Sanjeev Gambhir, David L. Officer, Gordon G. Wallace Jan 2013

Covalently Linked Biocompatible Graphene/Polycaprolactone Composites For Tissue Engineering, Sepidar Sayyar, Eoin Murray, Brianna C. Thompson, Sanjeev Gambhir, David L. Officer, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

Two synthesis routes to graphene/polycaprolactone composites are introduced and the properties of the resulting composites compared. In the first method, mixtures are produced using solution processing of polycaprolactone and well dispersed, chemically reduced graphene oxide and in the second, an esterification reaction covalently links polycaprolactone chains to free carboxyl groups on the graphene sheets. This is achieved through the use of a stable anhydrous dimethylformamide dispersion of graphene that has been highly chemically reduced resulting in mostly peripheral ester linkages. The resulting covalently linked composites exhibit far better homogeneity and as a result, both Young's modulus and tensile strength more …

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Synergetic Combination Of Limd With Chpd For The Production Of Economical And High Performance Mgb2 Wires, Minoru Maeda, Md Shahriar Ai Hossain, Ashkan Motaman, Jung Ho Kim, Anna Kario, Matt Rindfleisch, Mike Tomsic, S X. Dou Jan 2013

Synergetic Combination Of Limd With Chpd For The Production Of Economical And High Performance Mgb2 Wires, Minoru Maeda, Md Shahriar Ai Hossain, Ashkan Motaman, Jung Ho Kim, Anna Kario, Matt Rindfleisch, Mike Tomsic, S X. Dou

Australian Institute for Innovative Materials - Papers

We propose an economical fabrication concept, the localized internal magnesium diffusion (IMD) method. Instead of using a single magnesium (Mg) rod in the center of a metal sheath tube, we use large-sized Mg particles (20-50 mesh) mixed well with cheap 97% crystalline boron powder to fill the metal sheath tube. After a repeated drawing process, the coarse Mg is elongated along the core wire axis of the metal sheath tube. Textured MgB2 grains are then formed during the sintering process. In the localized IMD process, however, there is still a need to improve the overall density. In order to increase …

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The Effect Of Microscopic Texture On The Direct Plasma Surface Passivation Of Si Solar Cells, S Mehrabian, S Xu, A A. Qaemi, B Shokri, C Chan, K Ostrikov Jan 2013

The Effect Of Microscopic Texture On The Direct Plasma Surface Passivation Of Si Solar Cells, S Mehrabian, S Xu, A A. Qaemi, B Shokri, C Chan, K Ostrikov

Australian Institute for Innovative Materials - Papers

Textured silicon surfaces are widely used in manufacturing of solar cells due to increasing the light absorption probability and also the antireflection properties. However, these Si surfaces have a high density of surface defects that need to be passivated. In this study, the effect of the microscopic surface texture on the plasma surface passivation of solar cells is investigated. The movement of 105Hþ ions in the texture-modified plasma sheath is studied by Monte Carlo numerical simulation. The hydrogen ions are driven by the combined electric field of the plasma sheath and the textured surface. The ion dynamics is simulated, and …

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Organic Solvent-Based Graphene Oxide Liquid Crystals: A Facile Route Toward The Next Generation Of Self-Assembled Layer-By-Layer Multifunctional 3d Architectures, Rouhollah Jalili, Seyed Hamed Aboutalebi, Dorna Esrafilzadeh, Konstantin Konstantinov, Simon E. Moulton, Joselito M. Razal, Gordon G. Wallace Jan 2013

Organic Solvent-Based Graphene Oxide Liquid Crystals: A Facile Route Toward The Next Generation Of Self-Assembled Layer-By-Layer Multifunctional 3d Architectures, Rouhollah Jalili, Seyed Hamed Aboutalebi, Dorna Esrafilzadeh, Konstantin Konstantinov, Simon E. Moulton, Joselito M. Razal, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

We introduce soft self-assembly of ultralarge liquid crystalline (LC) graphene oxide (GO) sheets in a wide range of organic solvents overcoming the practical limitations imposed on LC GO processing in water. This expands the number of known solvents which can support amphiphilic self-assembly to ethanol, acetone, tetrahydrofuran, N-dimethylformamide, N-cyclohexyl-2-pyrrolidone, and a number of other organic solvents, many of which were not known to afford solvophobic self-assembly prior to this report. The LC behavior of the as-prepared GO sheets in organic solvents has enabled us to disperse and organize substantial amounts of aggregate-free single-walled carbon nanotubes (SWNTs, up to 10 wt …

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Tensile Testing Of Individual Glassy, Rubbery And Hydrogel Electrospun Polymer Nanofibres To High Strain Using The Atomic Force Microscope, Adrian Gestos, Philip G. Whitten, Geoffrey M. Spinks, Gordon G. Wallace Jan 2013

Tensile Testing Of Individual Glassy, Rubbery And Hydrogel Electrospun Polymer Nanofibres To High Strain Using The Atomic Force Microscope, Adrian Gestos, Philip G. Whitten, Geoffrey M. Spinks, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

The production and use of polymer nanofibre assemblies prepared by electrospinning is now widespread. It is known that the tensile properties of electrospun polymer fibres can be different to those of bulk polymers. Here, we report a general method for measuring the tensile properties of individual electrospun nanofibres that employs a commercial atomic force microscope. Methods for preparing samples, force calibration and calculation of tensile stress and strain are described along with error estimation. By appropriate choice of AFM cantilever, it is shown that the tensile stress-strain curves can be measured for glassy, rubbery and gel polymer nanofibres. Testing can …

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A Light-Assisted, Polymeric Water Oxidation Catalyst That Selectively Oxidizes Seawater With A Low Onset Potential, Jun Chen, Pawel W. Wagner, Lei Tong, Danijel Boskovic, Weimin Zhang, David L. Officer, Gordon G. Wallace, Gerhard F. Swiegers Jan 2013

A Light-Assisted, Polymeric Water Oxidation Catalyst That Selectively Oxidizes Seawater With A Low Onset Potential, Jun Chen, Pawel W. Wagner, Lei Tong, Danijel Boskovic, Weimin Zhang, David L. Officer, Gordon G. Wallace, Gerhard F. Swiegers

Australian Institute for Innovative Materials - Papers

Vapour phase polymerisation (vpp) of PEDOT to incorporate high levels of a sulphonated manganese porphyrin yields a vivid green conducting polymer that, under illumination, catalyzes selective oxidation of water from seawater from ca. 0.40 V (vs. NHE; Pt counter electrode) without observable chlorine formation. This onset potential is comparable to that of certain metal oxide semiconductors that achieve higher photocurrents but are not capable of selectively oxidising the water in seawater.

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