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Full-Text Articles in Physical Sciences and Mathematics

Frequency Dynamics During High Ccgt And Wind Penetrations, Lasantha Meegahapola, Damian Flynn Dec 2013

Frequency Dynamics During High Ccgt And Wind Penetrations, Lasantha Meegahapola, Damian Flynn

Dr Lasantha G Meegahapola

Frequency stability is the paramount concern for secure and reliable operation of a power system. High wind penetration levels are reported in power systems with high thermal generation, and hence its likely to result high wind and combined-cycle gas turbine (CCGT) penetrations during system operation since CCGTs are the most preferable choice for the thermal generation. The doubly-fed induction generators (DFIGs) do not provide any inertial response while the CCGTs have unique frequency response during the system frequency disturbances. Therefore, CCGT turbine response characteristics and the zero inertial response may influence on frequency dynamics of a power network. The main …


N-Glycolisation Regulates Endothelial Lipase-Mediated Phospholipid Hydrolysis In Apoe- And Apoa-I-Containing High Density Lipoproteins, Danielle Skropeta, Daniel Rader, Weijun Jin, Monica Mcmahon, Kate Shearston, Philip Barter, Kristine Mcgrath, Kerry-Anne Rye, Chatri Settasatian, Daniela Caiazza Nov 2013

N-Glycolisation Regulates Endothelial Lipase-Mediated Phospholipid Hydrolysis In Apoe- And Apoa-I-Containing High Density Lipoproteins, Danielle Skropeta, Daniel Rader, Weijun Jin, Monica Mcmahon, Kate Shearston, Philip Barter, Kristine Mcgrath, Kerry-Anne Rye, Chatri Settasatian, Daniela Caiazza

Danielle Skropeta

No abstract provided.


High-Yield Cell-Free Protein Synthesis For Site-Specific Incorporation Of Unnatural Amino Acids At Two Sites, Kiyoshi Ozawa, Karin V. Loscha, Kekini V. Kuppan, Choy Theng Loh, Nicholas E. Dixon, Gottfried Otting Jul 2013

High-Yield Cell-Free Protein Synthesis For Site-Specific Incorporation Of Unnatural Amino Acids At Two Sites, Kiyoshi Ozawa, Karin V. Loscha, Kekini V. Kuppan, Choy Theng Loh, Nicholas E. Dixon, Gottfried Otting

Professor Nick E Dixon

Using aminoacyl-tRNA synthetase/suppressor tRNA pairs derived from Methanocaldococcus jannaschii, an Escherichia coli cell-free protein production system affords proteins with site-specifically incorporated unnatural amino acids (UAAs) in high yields through the use of optimized amber suppressor tRNACUA opt and optimization of reagent concentrations. The efficiency of the cell-free system allows the incorporation of trifluoromethyl-phenylalanine using a polyspecific synthetase evolved previously for p-cyanophenylalanine, and the incorporation of UAAs at two different sites of the same protein without any re-engineering of the E. coli cells used to make the cell-free extract.


Comparison Of Small-Field Behaviour In Mgb2, Low And High Temperature Superconductors, Alexey V. Pan, S X. Dou Jun 2013

Comparison Of Small-Field Behaviour In Mgb2, Low And High Temperature Superconductors, Alexey V. Pan, S X. Dou

Shi Xue Dou

Different types of superconductors have been investigated at small magnetic fields (Ba) over wide temperature (T) ranges at different Ba orientations. It has been shown that the temperature dependence of the characteristic field (B*), separating the Ba-independent critical current density (Jc) plateau (single vortex pinning regime) and the region with Jc(Ba) (collective pinning), can be attributed either to the temperature dependence of the magnetic penetration depth for Nb-film and MgB2bulk superconductors, or to thermally activated processes for Bi-based superconductors and YBa2Cu3O7−δ superconducting films. In both cases the vortex pinning influence appears to have a secondary role, affecting the effective vortex …


Band Structures, Magnetic Properties, And Enhanced Magnetoresistance In The High Pressure Phase Of Gd And Y Doped Two-Dimensional Perovskite Sr2coo4 Compounds, Xiaolin Wang, E Takayama-Muromachi, S X. Dou, Zhenxiang Cheng Jun 2013

Band Structures, Magnetic Properties, And Enhanced Magnetoresistance In The High Pressure Phase Of Gd And Y Doped Two-Dimensional Perovskite Sr2coo4 Compounds, Xiaolin Wang, E Takayama-Muromachi, S X. Dou, Zhenxiang Cheng

Shi Xue Dou

The authors present their studies on the band structures and on the magnetic and magnetotransport properties of the high pressure phase of Sr2-xRExCoO4 [rare earth (RE)=Gd and Y, x=0.1-0.5] compounds which were synthesized by a high pressure and high temperature technique. The authors found that as x increases, the magnetoresistance {(PH-P0)/p0} increases up to -17% at 5 K and 7 T, which is 2.5 times higher than that for undoped Sr2CoO4, although the ferromagnetic transition drops from 255 to 200 K for the Gd doping with x=0.3. The saturation moments at low temperature are significantly enhanced for the Gd doped …


A High-Resolution Record Of Vegetation And Climate Through The Last Glacial Cycle From Caledonia Fen, Southeastern Highlands Of Australia, A Kershaw, G Mckenzie, N Porch, Richard Roberts, J Browne, H Heijnis, M Orr, Geraldine Jacobsen, P Newall Mar 2013

A High-Resolution Record Of Vegetation And Climate Through The Last Glacial Cycle From Caledonia Fen, Southeastern Highlands Of Australia, A Kershaw, G Mckenzie, N Porch, Richard Roberts, J Browne, H Heijnis, M Orr, Geraldine Jacobsen, P Newall

Richard G Roberts

A blocked tributary has provided a rare site of long-term sediment accumulation in montane southeastern Australia. This site has yielded a continuous, detailed pollen record through the last ca. 140 000 years and revealed marked vegetation and environmental changes at orbital to sub-millennial scales. Radiocarbon and optically stimulated luminescence (OSL, or optical) ages provide some chronological control for the last ca. 70 000 years. Most of the sediment is inorganic but with well preserved pollen that accumulated under unproductive and probably largely ice-covered lake conditions. The lake was surrounded by low-growing plants with an alpine character. Exceptions include three discrete …


The Role Of Unbound Oligomers In The Nucleation And Growth Of Electrodeposited Polypyrrole And Method For Preparing High Strength, High Conductivity Films, Wen Zheng, Joselito M. Razal, Geoffrey M. Spinks, Van-Tan Truong, Philip G. Whitten, Gordon G. Wallace Mar 2013

The Role Of Unbound Oligomers In The Nucleation And Growth Of Electrodeposited Polypyrrole And Method For Preparing High Strength, High Conductivity Films, Wen Zheng, Joselito M. Razal, Geoffrey M. Spinks, Van-Tan Truong, Philip G. Whitten, Gordon G. Wallace

Gordon Wallace

Polypyrrole is a material with immensely useful properties suitable for a wide range of electrochemical applications, but its development has been hindered by cumbersome manufacturing processes. Here we show that a simple modification to the standard electrochemical polymerization method produces polypyrrole films of equivalently high conductivity and superior mechanical properties in one-tenth of the polymerization time. Preparing the film as a series of electrodeposited layers with thorough solvent washing between layering was found to produce excellent quality films even when layer deposition was accelerated by high current. The washing step between the sequentially polymerized layers altered the deposition mechanism, eliminating …


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 …


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, …


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 …


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 …


A Significant Improvement In Both Low- And High-Field Performance Of Mgb2 Superconductors Through Graphene Oxide Doping, K S B De Silva, S H Aboutalebi, Xun Xu, Xiaolin Wang, W X Li, Konstantin Konstantinov, S X. Dou Jan 2013

A Significant Improvement In Both Low- And High-Field Performance Of Mgb2 Superconductors Through Graphene Oxide Doping, K S B De Silva, S H Aboutalebi, Xun Xu, Xiaolin Wang, W X Li, Konstantin Konstantinov, S X. Dou

Australian Institute for Innovative Materials - Papers

The effects of graphene oxide (GO) doping on the superconducting properties of MgB2 were studied using bulk samples made by the diffusion method. Homogeneous dispersions of GO in tetrahydrofuran were obtained through a novel synthesis method, which is then chemically doped with MgB2. It was found that GO doping significantly improves the critical current density, under both low and high magnetic fields, which distinguishes GO from all the other elements doped into MgB2 so far. 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.


Extrusion Printing Of Ionic-Covalent Entanglement Hydrogels With High Toughness, Shannon Bakarich, Marc In Het Panhuis, Stephen T. Beirne, Gordon G. Wallace, Geoffrey Maxwell Spinks Jan 2013

Extrusion Printing Of Ionic-Covalent Entanglement Hydrogels With High Toughness, Shannon Bakarich, Marc In Het Panhuis, Stephen T. Beirne, Gordon G. Wallace, Geoffrey Maxwell Spinks

Australian Institute for Innovative Materials - Papers

Three-dimensional (3D) printing of hydrogels has recently been investigated for use in tissue engineering applications. One major limitation in the use of synthetic hydrogels is their poor mechanical robustness but the development of ‘tough hydrogels’ in conjunction with additive fabrication techniques will accelerate the advancement of many technologies including soft robotics, bionic implants, sensors and controlled release systems. This article demonstrates that ionic–covalent entanglement (ICE) gels can be fabricated through a modified extrusion printing process that facilitates in situ photopolymerisation. The rheological properties of alginate–acrylamide hydrogel precursor solutions were characterised to develop formulations suitable for extrusion printing. A range of …


Cell Attachment And Proliferation On High Conductivity Pedot-Glycol Composites Produced By Vapour Phase Polymerisation, Elise M. Stewart, Manrico Fabretto, Mischa Mueller, Paul J. Molino, Hans J. Griesser, Robert D. Short, Gordon G. Wallace Jan 2013

Cell Attachment And Proliferation On High Conductivity Pedot-Glycol Composites Produced By Vapour Phase Polymerisation, Elise M. Stewart, Manrico Fabretto, Mischa Mueller, Paul J. Molino, Hans J. Griesser, Robert D. Short, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

High conductivity poly(3,4-ethylene dioxythiophene) (PEDOT) was synthesised using vacuum vapour phase polymerization (VVPP). The process produces PEDOT composites which incorporate glycol within the polymer. To assess biocompatibility, a suite of analytical techniques were utilised in an effort to characterise the level of glycol present and its impact on cell attachment and proliferation. A small decrease in fibroblast cell attachment and proliferation was observed with increasing glycol content within the PEDOT composite. Keratinocyte cell attachment and proliferation by comparison showed an increase. As such, the results herein indicate that cell attachment and proliferation depends on the individual cell lines used and …


A Hybrid Electrolyte Energy Storage Device With High Energy And Long Life Using Lithium Anode And Mno2 Nanoflake Cathode, Shulei Chou, Yun-Xiao Wang, Jiantie Xu, Jia-Zhao Wang, Hua-Kun Liu, S X. Dou Jan 2013

A Hybrid Electrolyte Energy Storage Device With High Energy And Long Life Using Lithium Anode And Mno2 Nanoflake Cathode, Shulei Chou, Yun-Xiao Wang, Jiantie Xu, Jia-Zhao Wang, Hua-Kun Liu, S X. Dou

Australian Institute for Innovative Materials - Papers

A hybrid electrolyte energy storage system combining the features of supercapacitors and lithium batteries has been constructed. It consists of MnO2 nanoflakes in 1 M Li2SO4 aqueous electrolyte as the cathode and lithium foil in ionic liquid (1 M lithium bis(trifluoromethanesulfonyl)imide (LiNTf2) in N-methyl-N-propyl pyrrolidinium bis(trifluoromethanesulfonyl)imide ([C(3)mpyr][NTf2])) electrolyte as the anode, separated by a lithium super ionic conductor glass ceramic film (LiSICON). This system shows the advantages of both a supercapacitor (long cycle life) and a lithium battery (high energy), as well as low cost and improved safety due to the combination of ionic liquid and ceramic solid state electrolyte …


High Strain Stretchable Solid Electrolytes, Sureyya Saricilar, Dennis Antiohos, Kewei Shu, Philip G. Whitten, Klaudia Wagner, Caiyun Wang, Gordon G. Wallace Jan 2013

High Strain Stretchable Solid Electrolytes, Sureyya Saricilar, Dennis Antiohos, Kewei Shu, Philip G. Whitten, Klaudia Wagner, Caiyun Wang, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

Wearable electronic devices that can be integrated seamlessly into clothing for monitoring and feedback need to be not only flexible, but also stretchable with low stiffness. Currently there are few solid electrolytes that are sufficiently stretchable for wearable electronic devices. Here we report stretchable solid electrolytes that can be elastically stretched more than 500% of their original length with ionic conductivities as high as 7 x 10(-5) S cm(-1) and tensile breaking strengths larger than 1.5 MPa. These solid electrolytes consist of poly(methyl methacrylate) chemical networks solvated by an electrochemically stable ionic liquid. A stretchable supercapacitor was demonstrated by coating …


The Electrochemical Properties Of High-Capacity Sulfur/Reduced Graphene Oxide With Different Electrolyte Systems, Yunxiao Wang, Shulei Chou, Hua-Kun Liu, S X. Dou Jan 2013

The Electrochemical Properties Of High-Capacity Sulfur/Reduced Graphene Oxide With Different Electrolyte Systems, Yunxiao Wang, Shulei Chou, Hua-Kun Liu, S X. Dou

Australian Institute for Innovative Materials - Papers

The lithium/sulfur battery is a promising electrochemical system with high capacity, which is well-known to undergo a complex multistep reaction during the discharge process. Two types of electrolytes including poly (ethylene glycol) dimethyl ether (PEGDME)-based and 1.3 - dioxolane (DOL)/ dimethoxyethane (DME)-based electrolytes were investigated here. Furthermore, LiNO3 additive was introduced into the electrolyte in order to effectively eliminate the overcharge effect. The lithium sulfur battery with 1.0 M LiN(CF3SO2)2 in PEGME with 0.1 M LiNo3 shows highly stable reversible capacity of 624.8 mAh g-1 after 200 cycles and improved average coulombic efficiency of 98 percent.


Removal Of Na+ From Ionic Liquids By Zeolite For High Quality Electrolyte Manufacture, Won-Je Cho, Yongseong Seo, Soon Jae Jung, Won-Gil Lee, Byung Chul Kim, Grant A. Mathieson, Kook Hyun Yu Jan 2013

Removal Of Na+ From Ionic Liquids By Zeolite For High Quality Electrolyte Manufacture, Won-Je Cho, Yongseong Seo, Soon Jae Jung, Won-Gil Lee, Byung Chul Kim, Grant A. Mathieson, Kook Hyun Yu

Australian Institute for Innovative Materials - Papers

This study develops a novel method to remove the free cations created during the synthesis of ionic liquid. The cations are removed from the ionic liquid by size-selective adsorption onto chemically surface-modified Zeolite. The porous crystal nano-structure of Zeolite has several electron-rich Al sites to attract cations. While large cations of an ionic liquid cannot access the Zeolite nano-structure, small cations like Na+ have ready access and are adsorbed. This study confirms that: Na+ can be removed from ionic liquid effectively using Zeolite; and, in contrast to the conventional and extensively applied ion exchange resin method or solvent extraction methods, …