Physical Sciences and Mathematics Commons^™

Charge-Controlled Switchable Co2 Capture On Boron Nitride Nanomaterials, Qiao Sun, Zhen Li, Debra J. Searles, Ying Chen, Gao Qing (Max) Lu, Aijun Du

Australian Institute for Innovative Materials - Papers

Increasing concerns about the atmospheric CO2 concentration and its impact on the environment are motivating researchers to discover new materials and technologies for efficient CO2 capture and conversion. Here, we report a study of the adsorption of CO2, CH4, and H2 on boron nitride (BN) nanosheets and nanotubes (NTs) with different charge states. The results show that the process of CO2 capture/release can be simply controlled by switching on/off the charges carried by BN nanomaterials. CO2 molecules form weak interactions with uncharged BN nanomaterials and are weakly adsorbed. When extra electrons are introduced to these nanomaterials (i.e., when they are …

Microstructures Of Conducting Polymers: Patterning And Actuation Study, Babita Gaihre, Bo Weng, Syed A. Ashraf, Geoffrey M. Spinks, Peter C. Innis, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

The conducting polymers exhibit electrochemically driven expansion and shrinkage due to ingress and egress of dopant ions in response to potential applied. In this paper, we report on patterning of microdots and microsquares of polypyrrole (PPy), poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(3,3-dihexyl-3-4-dihydro-2H-thieno[3,4b][1,4]-dioxepine PProDOT(Hx) 2 and their behaviour under voltage change. Stainless steel mesh was used to deposit microdots and inkjet-printed cellulose girds were used to deposit microsqures of the conducting polymers on the ITO surface. It was found that PPy showed distinct actuation in the z direction while colour change was prominent in the case of PEDOT and PProDOT(Hx)2.

Enhanced Pinning In Superconducting Thin Films With Graded Pinning Landscapes, M Motta, F Colauto, W A. Ortiz, J Fritzsche, J Cuppens, W Gillijns, V V. Moshchalkov, T H. Johansen, A W Sanchez, A Silhanek

Australian Institute for Innovative Materials - Papers

A graded distribution of antidots in superconducting a-Mo 79Ge21 thin films has been investigated by magnetization and magneto-optical imaging measurements. The pinning landscape has maximum density at the sample border, decreasing linearly towards the center. Its overall performance is noticeably superior than that for a sample with uniformly distributed antidots: For high temperatures and low fields, the critical current is enhanced, whereas the region of thermomagnetic instabilities in the field-temperature diagram is significantly suppressed. These findings confirm the relevance of graded landscapes on the enhancement of pinning efficiency, as recently predicted by Misko and Nori [Phys. Rev. B 85, 184506 …

Synthesis Of Hollow Geo2 Nanostructures, Transformation Into Geoc, And Lithium Storage Properties, Li Li, Kuok H. Seng, Chuanqi Feng, Hua-Kun Liu, Zaiping Guo

Australian Institute for Innovative Materials - Papers

In this work, we synthesize mesoporous and hollow germanium@carbon nanostructures through simultaneous carbon coating and reduction of a hollow ellipsoidal GeO2 precursor. The formation mechanism of GeO 2 ellipsoids and the ratio of Ge4+ to Sn4+ as the starting materials are also investigated. Compared to the solid ellipsoidal Ge@carbon (Ge@C-3), the hollow ellipsoidal Ge@C-1 sample exhibits better cycling stability (100% capacity retention after 200 cycles at the 0.2 C rate) and higher rate capability (805 mA h g-1 at 20 C) compared to Ge@C-3 due to its unique hollow structure; therefore, this hollow ellipsoidal Ge@carbon can be considered as a …

Magnetic Phase Diagram And Correlation Between Metamagnetism And Superconductivity In Ru0.9sr2ycu2.1o7.9, Rashmi Nigam, Shane J. Kennedy, Alexey V. Pan, S X. Dou

Australian Institute for Innovative Materials - Papers

The magnetic superconductor Ru_0.9Sr₂YCu_2.1O_7.9 (Ru-1212Y) has been investigated using neutron diffraction under variable temperature and magnetic field. With the complementary information from magnetization measurements, we propose a magnetic phase diagram T-H for the Ru-1212 system. Uniaxial antiferromagnetic (AFM) order of 1.2μ _B/Ru atoms with moments parallel to the c-axis is found below the magnetic transition temperature at ~140 K in the absence of magnetic field. In addition, ferromagnetism (FM) in the ab-plane develops below ~120 K, but is suppressed at lower temperature by superconducting correlations. Externally applied …

Critical Phenomena And Estimation Of The Spontaneous Magnetization By A Magnetic Entropy Analysis In Mn0.96nb0.04coge Alloy, Jyotish C. Debnath, A M. Strydom, P Shamba, Jianli Wang, S X. Dou

Australian Institute for Innovative Materials - Papers

Magnetic and magnetocaloric properties of the alloy Mn0.96Nb0.04CoGe have been investigated.

Zno-Doped Lifepo4 Cathode Material For Lithium-Ion Battery Fabricated By Hydrothermal Method, Yemin Hu, Jun Yao, Zhe Zhao, Mingyuan Zhu, Ying Li, Hongming Jin, Huijun Zhao, Jiazhao Wang

Australian Institute for Innovative Materials - Papers

LiFePO4 particles doped with zinc oxide was synthesized via a hydrothermal route and used as cathode material for lithium-ion battery. Sample of preferable shape and structure was obtained by a concise and efficient process. ZnO doping into the LiFePO4 matrix was positively confirmed by the results of X-ray diffraction (XRD); high-resolution transmission electron microscopy (HRTEM); energy dispersive spectrometer (EDS), and X-ray photoelectron spectroscopy (XPS). LiFePO4 doped with ZnO tends to form nanometer-size and homogeneous particles, which can improve markedly the performance and stability of charge-discharge cycle. A specific discharge capacity of ZnO-doped LiFePO4 at 132.3 mAh g-1 was achieved, with …

Co3o4 Nanorods Decorated Reduced Graphene Oxide Composite For Oxygen Reduction Reaction In Alkaline Electrolyte, Mingyan Wang, Junrao Huang, Meng Wang, Dongen Zhang, Weimin Zhang, Weihua Li, Jun Chen

Australian Institute for Innovative Materials - Papers

Highly uniform Co3O4 nanorods decorated on reduced graphene oxide (rGO) were prepared by a one-pot hydrothermal procedure. During the hydrothermal process, Co2+ ions were crystallized to Co3O4 nanorods and simultaneously GO was reduced to rGO to form the Co3O4/rGO hybrid. The Co3O4/rGO hybrid was characterized by scanning electron micrographs, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy. The obtained Co3O4/rGO hybrid exhibits excellent electrocatalytic performance for oxygen reduction reaction.

Intrinsically Stretchable Supercapacitors Composed Of Polypyrrole Electrodes And Highly Stretchable Gel Electrolyte, Chen Zhao, Caiyun Wang, Zhilian Yue, Kewei Shu, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

There has been an emerging interest in stretchable power sources compatible with flexible/wearable electronics. Such power sources must be able to withstand large mechanical strains and still maintain function. Here we report a highly stretchable H3PO4-poly(vinyl alcohol) (PVA) polymer electrolyte obtained by optimizing the polymer molecular weight and its weight ratio to H3PO4 in terms of conductivity and mechanical properties. The electrolyte demonstrates a high conductivity of 3.4 x 10-3 S cm-1, and a high fracture strain at 410% elongation. It is mechanically robust with a tensile strength of 2 MPa and a Young's modulus of 1 MPa, and displays …

Architecture Designed Zno Hollow Microspheres With Wide-Range Visible-Light Photoresponses, Ziqi Sun, Ting Liao, Jae-Geun Kim, Kesong Liu, Lei Jiang, Jung Ho Kim, S X. Dou

Australian Institute for Innovative Materials - Papers

It is a challenge to increase the visible-light photoresponses of wide-gap metal oxides. In this study, we proposed a new strategy to enhance the visible-light photoresponses of wide-gap semiconductors by deliberately designing a multi-scale nanostructure with controlled architecture. Hollow ZnO microspheres with constituent units in the shape of one-dimensional (1D) nanowire networks, 2D nanosheet stacks, and 3D mesoporous nanoball blocks are synthesized via an approach of two-step assembly, where the oligomers or the constituent nanostructures with specially designed structures are first formed, and then further assembled into complex morphologies. Through deliberate designing of constituent architectures allowing multiple visible-light scattering, reflections, …

Microwave Characterization Of Carbon Nanotube Yarns For Uwb Medical Wireless Body Area Networks, Syed Muzahir Abbas, Oya Sevimli, Michael C. Heimlich, Karu P. Esselle, B Kimiaghalam, Javad Foroughi, Farzad Safaei

Australian Institute for Innovative Materials - Papers

Carbon nanotube (CNT) yarns are novel CNT-based materials that extend the advantages of CNT from the nanoscale to macroscale applications. In this study, we have modeled CNT yarns as potential data transmission lines. Test structures have been designed to measure electrical properties of CNT yarns, which are attached to these test structures using gold paste. DC testing and microwave S-parameter measurements have been conducted for characterization. The observed frequency independent resistive behavior of the CNT yarn is a very promising indicator that this material, with its added values of mechanical resilience and thermal conductivity, could be invaluable for a range …

Reaction Method Control Of Impurity Scattering In C-Doped Mgb2: Proving The Role Of Defects Besides C Substitution Level, S K. Chen, K Y. Tan, A S. Halim, X Xu, K S. B De Silva, W K. Yeoh, S X. Dou, A Kursumovic, J L. Macmanus-Driscoll

Australian Institute for Innovative Materials - Papers

In this study, Si and C were incorporated into polycrystalline MgB2 via in situ reaction of Mg and B with either SiC or with separate Si and C (Si+C). The electrical transport and magnetic properties of the two series of samples were compared. The corrected resistivity at 40K, pA(40K), is higher for the SiC reacted samples regardless of carbon (C) substitution level, indicating larger intragrain scattering because of the simultaneous reaction between Mg and SiC and carbon substitution during the formation of MgB2. In addition, because of the cleaner reaction route for the SiC reacted samples, the calculated active area …

Pdni Hollow Nanoparticles For Improved Electrocatalytic Oxygen Reduction In Alkaline Environments, Meng Wang, Weimin Zhang, Jiazhao Wang, David Wexler, Simon D. Poynton, Robert C.T Slade, Hua-Kun Liu, Bjorn Winther-Jensen, Robert Kerr, Dongqi Shi, Jun Chen

Australian Institute for Innovative Materials - Papers

Palladium-Nickel (Pd-Ni) hollow nanoparticles were synthesized via a modified galvanic replacement method using Ni nanoparticles as sacrificial templates in an aqueous medium. X-ray diffraction and transmission electron microscopy show that the as-synthesized nanoparticles are alloyed nanostructures and have hollow interiors with an average particle size of 30 nm and shell thickness of 5 nm. Compared with the commercially available Pt/C or Pd/C catalysts, the synthesized PdNi/C has superior electrocatalytic performance towards the oxygen reduction reaction, which makes it a promising electrocatalyst for alkaline anion exchange membrane fuel cells and alkali-based air-batteries. The electrocatalyst is finally examined in an H2/O2 alkaline …

Porous Titania Nanosheet/Nanoparticle Hybrids As Photoanodes For Dye-Sensitized Solar Cells, Yang Bai, Zheng Xing, Hua Yu, Zhen Li, Rose Amal, Lianzhou Wang

Australian Institute for Innovative Materials - Papers

Porous titania nanohybrids (NHs) were successfully prepared by hybridizing the exfoliated titania nanosheets with anatase TiO2 nanoparticles. Various characterizations revealed that the titania NHs as photoanodes play a trifunctional role (light harvesting, dye adsorption, and electron transfer) in improving the efficiency (η) of the dye-sensitized solar cells. The optimized photoanode consisting layered NHs demonstrated a high overall conversion efficiency of 10.1%, remarkably enhanced by 29.5% compared to that (7.8%) obtained from the benchmark P25 nanoparticles under the same testing conditions.

Critical Behaviour Of Ho2fe17-Xmnx-Magnetisation And Mössbauer Spectroscopy, Jianli Wang, S J. Campbell, S J. Kennedy, S X. Dou

Australian Institute for Innovative Materials - Papers

The magnetic properties of Ho2Fe17 − xMnx compounds (x = 0–2) of ferromagnetic ordering temperatures up to TC ~344 K have been investigated by DC magnetization and Mössbauer effect measurements. The nature of the magnetic phase transitions and the critical behaviour around TC has been investigated by analysis of the magnetisation data and the critical exponents β, γ and δ determined. The critical exponents are found to be similar to the theoretical values of the mean-field model for which β = 0.5 and γ = 1.0, indicating the existence of a long-range ferromagnetic interactions. The isothermal entropy changes ΔS around …

Thz Photomixer With A 40-Nm-Wide Nanoelectrode Gap On Low-Temperature Grown Gaas, G Seniutinas, G Gervinskas, E Constable, A Krotkus, G Molis, G Valusis, Roger A. Lewis, S Juodkazis

Australian Institute for Innovative Materials - Papers

A terahertz (THz or T-rays) photomixer consisting of a meander type antenna with integrated nanoelectrodes on a low temperature grown GaAs (LT-GaAs) is demonstrated. The antenna was designed for molecular fingerprinting and sensing applications within a spectral range of 0.3-0.4 THz. A combination of electron beam lithography (EBL) and focused ion beam (FIB) milling was used to fabricate the T-ray emitter. Antenna and nanoelectrodes were fabricated by standard EBL and lift-off steps. Then a 40-nm-wide gap in an active photomixer area separating the nanoelectrodes was milled by a FIB. The integrated nano-contacts with nano-gaps enhance the illuminated light and THz …

Multifunctional Conducting Polymer Fibres For Drug Delivery Applications, Dorna Esrafilzadeh, Simon E. Moulton, Joselito M. Razal, Elise M. Stewart, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

Advances in the fabrication of neuroprosthetic electrodes have attracted considerable interest from biomedical researchers. These electrodes are incorporated into a neuroprosthetic device capable of, electrically stimulating and recording of neuron activity. Critical to the successful application of these electrodes is their biocompatibility, stable conductivity, lower impedance and flexibility whilst maintaining appropriate mechanical properties [1] .

Hybrid Agent Based Simulation With Adaptive Learning Of Travel Mode Choices For University Commuters (Wip), Nagesh Shukla, Albert Munoz, Jun Ma, Nam Huynh

SMART Infrastructure Facility - Papers

This paper presents a methodology for developing a hybrid agent-based micro-simulation model to capture the impacts of commuter travel mode choices on a University campus transport network. The proposed methodology involves: (i) developing realistic population of commuter agents (students and staff); (ii) assigning activity lists and travel mode choices to agents using machine learning method; and, (iii) traffic micro-simulation of the study area transport network. This furthers the understanding of current transport modal distributions, factors affecting the travel mode choice decisions, and, network performance through a number of hypothetical travel scenarios.

Next Generation Mdm-The New 360 View, Joe Minervini, Craig Napier

SMART Infrastructure Facility - Papers

If your priority is to establish best in class customer-centricity principles in your business, then please join us for a review of how relationship centric MDM is the newest and most effective way to take command of your customer data and deliver business value faster. In this session you will hear how Pitney Bowes Software is assisting the University of Wollongong in expanding their vision of using Information Management to improve research outcomes, commercial partnerships and student learning experiences. This session will examine the: • Utilisation of Master Data principles and Relationship Analysis in understanding and exploring the current state …

N-Nitrosamine Rejection By Reverse Osmosis Membranes: A Full-Scale Study, Takahiro Fujioka, Stuart J. Khan, James A. Mcdonald, Annalie Roux, Yvan Poussade, Jorg E. Drewes, Long D. Nghiem

SMART Infrastructure Facility - Papers

This study aims to provide longitudinal and spatial insights to the rejection of N-nitrosamines by reverse osmosis (RO) membranes during sampling campaigns at three full-scale water recycling plants. Samples were collected at all individual filtration stages as well as at a cool and a warm weather period to elucidate the impact of recovery and feed temperature on the rejection of N-nitrosamines. N-nitrosodimethylamine (NDMA) was detected in all RO feed samples varying between 7 and 32 ng/L. Concentrations of most other N-nitrosamines in the feed solutions were determined to be lower than their detection limits (3e5 ng/L) but higher concentrations were …

Improved Decision Making To Underpin The Achievement Of Strategic Goals At The University Of Wollongong, Craig Napier

SMART Infrastructure Facility - Papers

The Higher Education sector is an increasingly competitive environment. As such, it is prudent for institutions to seek advantages across all areas that will lead to improved research outcomes, commercial partnerships and student learning experience. The Performance Indicators Unit commenced in 1999 and has evolved to cover seven key perspectives of integration of Information Management across the University, working to avoid the operational silos that can occur within Universities. This session will explore: Utilising network relationship analysis to develop an understanding of the University of Wollongong's collaborations and facilitate improvement The importance of visualisation to translate data into meaningful information …

Modelling And Data Frameworks For Understanding Infrastructure Systems Throuh A Systems-Of-Systems Lens, Matthew J. Berryman, Rohan Wickramasuriya, Vu Lam Cao, Pascal Perez

SMART Infrastructure Facility - Papers

Modelling and analysis of large systems of infrastructure systems carries with it a number of challenges, in particular around the volume of data and the requisite complexity (and thus computing resources required) of models. In this paper we present an integrated land use–transportation model of a region in Sydney, and detail how we integrated an agent-based model of location and transport choice with a traffic micro-simulator. We also discuss both some novel architectures for scalability of modelling as well as for fusion and relevant visualisation of large data sets. We have a particular focus on geospatial infrastructure data visualisation.

A Semi-Deterministic Approach For Modelling Of Urban Travel Demand, Nam N. Huynh, Nagesh Shukla, Albert Munoz Aneiros, Vu Lam Cao, Pascal Perez

SMART Infrastructure Facility - Papers

This paper presents a methodology to construct travel related activity schedules for individuals in a synthetic population. The resulting list of activity schedules are designed as an input into a micro-simulator for urban transport dynamics analysis. The methodology involves two main steps. The first step generates a synthetic population based on census data sourced from the Australian Bureau of Statistics (ABS). The second step assigns individuals in the synthetic population activity schedules using Household Travel Survey (HTS) data related to the geographical area of interest (in this case, the Sydney Greater Metropolitan area). Each individual is assigned an ordered set …

Scene-Adaptive Configuration Of Two Cameras Using The Correspondence Field Function, F Safaei, Payam Mokhtarian, H Shidanshidi, W Li, Mohammad-Reza Namazi-Rad, A Mousavinia

SMART Infrastructure Facility - Papers

In a free viewpoint video system, the scene is captured by a number of cameras and it would be desirable to optimize the configuration of cameras, such as their location or orientation, to improve the rendering quality. This paper introduces a mathematical representation of the multi-camera geometry, called the correspondence field (CF), which can be used to quantify the suitability of a camera configuration for a given arrangement of objects in the scene. The correspondence field describes the spatial topology of the intersecting rays of cameras, arranged as a number of layers or surfaces in the field of view of …

Ten Trenches: A Scienceart Collaboration, Timothy J. Cohen, Martin Cohen, Stephanie Kermode, Michael G. Leggett

Faculty of Science - Papers (Archive)

Collaborative and cross-disciplinary research by a group of artists and scientists in an Australian rural setting generates data and ideas that form the basis of a wider understanding of the ramifications of global warming and cooling within the local, regional and national community. The work is viewed as an initial educational platform that will allow the public to see and understand the complexities of climate-based research.

Fate Of 17Α-Estradiol, 17Β-Estradiol, And Estrone In Agricultural Soils And Sediments, Michael L. Mashtare Jr

Open Access Dissertations

The shift to concentrated animal production facilities and increasing rural-urban migration has increased the localized land application of nearly 1 billion tons of manure and biosolids annually. Although these applications provide nutrients and contribute to soil tilth, they also serve as a source for an estimated 49 tons of the natural manure-borne estrogens, 17α-estradiol (17α-E2), 17β-estradiol (17β-E2), and estrone (E1). While these estrogens are critical to endocrine systems, the low concentrations observed in the environment can disrupt endocrine function in non-target organisms, e.g., altering secondary sex characteristics which can lead to changes in wildlife communities.

Research presented here focuses on …

Simulating Land Use Land Cover Change Using Data Mining And Machine Learning Algorithms, Amin Tayyebi

Open Access Dissertations

The objectives of this dissertation are to: (1) review the breadth and depth of land use land cover (LUCC) issues that are being addressed by the land change science community by discussing how an existing model, Purdue's Land Transformation Model (LTM), has been used to better understand these very important issues; (2) summarize the current state-of-the-art in LUCC modeling in an attempt to provide a context for the advances in LUCC modeling presented here; (3) use a variety of statistical, data mining and machine learning algorithms to model single LUCC transitions in diverse regions of the world (e.g. United States …

Information Measures For Statistical Orbit Determination, Alinda Kenyana Mashiku

Open Access Dissertations

The current Situational Space Awareness (SSA) is faced with a huge task of tracking the increasing number of space objects. The tracking of space objects requires frequent and accurate monitoring for orbit maintenance and collision avoidance using methods for statistical orbit determination. Statistical orbit determination enables us to obtain estimates of the state and the statistical information of its region of uncertainty given by the probability density function (PDF). As even collision events with very low probability are important, accurate prediction of collisions require the representation of the full PDF of the random orbit state. Through representing the full PDF …

The Palm-Tree Index: Indexing With The Crowd, Aamer Mahmood, Walid G. Aref, Eduard Dragut, Saleh Basalamah

Cyber Center Publications

Crowdsourcing services allow employing human intelligence in tasks that are difficult to accomplish with computers such as image tagging and data collection. At a relatively low monetary cost and through web interfaces such as Amazon’s Mechanical Turk (AMT), humans can act as a computational operator in large systems. Recent work has been conducted to build database management systems that can harness the crowd power in database operators, such as sort, join, count, etc. The fundamental problem of indexing within crowdsourced databases has not been studied. In this paper, we study the problem of tree-based indexing within crowd-nabled databases. We investigate …

Developing White Ash With Resistance To The Emerald Ash Borer, Kaitlin Joy Palla

Open Access Theses

Hypocotyls isolated from mature embryos germinated on Murashige and Skoog (MS) medium supplemented with 22.2 µM 6-benzyladenine (BA) and 0.5 µM thidiazuron (TDZ) were transformed using Agrobacterium tumefaciens strain EHA105 harboring the pBI121-8D2 vector containing the neomycin phosphotransferase (nptII) gene and a full length, codon-optimized Bacillus thuringiensis Cry8Da protoxin gene (cry8D2). Explants were transformed in a bacterial suspension with 100 µM acetosyringone using 90 s sonication and 10 min vacuum-infiltration. Four independent lines of transformed shoots were selectively regenerated on MS medium with 22.2 µM BA, 0.5 µM TDZ, 50 mg L^-1 adenine sulfate, 10% …