Deakin Research

Institute for Frontier Materials

IFM research seminar series 2013

These research seminars are held in the GTP Seminar Room (na1.417)

Date Time Presenter Presentation/topic
Friday 20th September 10am David Rossouw High-resolution TEM-EELS studies of metallic nanostructures and carbon nanotubes  

 Abstract

The most important advantage of the electron energy loss spectroscopy (EELS) technique, carried out in the transmission electron microscope (TEM), is its high spatial resolution capability. However, EELS has a poorer energy resolution than some other spectroscopy techniques. By incorporating a monochromator into the illumination system, the energy resolution of a TEM-EELS system can be improved, enabling enhanced visibility of fine details in acquired spectra. Here, EELS is performed with nanometer spatial resolution and sub 100 meV energy resolution, in the study of the surface plasmons in metallic nanostructures and in the identification of individual semiconducting and metallic carbon nanotubes in the valence and core energy loss regimes respectively. Multiple plasmonic excitations in silver nanostructures are spatially mapped and spectrally resolved in the infrared and visible electromagnetic regimes, and metallic and semiconducting SWCNTs are identified based on the fine structure of the recorded carbon K edge.

Friday 13th September 2pm Dr. Kei Saito Green Polymers - from Photo-responsible Reversible Polymers to Lignin Based Polymers  

 Abstract

Reversible polymers represent a relatively new class of materials that possess bonds capable of reversibly connecting and disconnecting monomers in response to stimuli such as heat or light. These reversible bonds can be used to construct a recyclable polymer via material polymerization and depolymerization, on demand. Several reversible polymerizations have been reported in the literature, however these are each based on thermally-reversible reactions, like the Diels-Alder reaction, which require high energies for depolymerization. These versatile photoreactions have been used to prepare simple cyclobutane-dimers, complicated organic molecules with constrained geometries such as ladderanes and cyclophane, and also regiospecific oligomeric and polymeric species. Photo-chemical reactions, on the other hand, are considered to be greener synthetic pathways because photons do not leave residues, they can be conducted at ambient temperature, and often in the solid-state. Using these green chemical principles, our reversible-polymer designs centre on a biologically-inspired mechanism. Thymine, one of the nucleic acid bases of DNA, has the propensity to reversibly photo-dimerize in the solid-state. Our research exploits this reversible dimerization to develop a novel, reversible, polymer-recycling system using di-thymine monomers. The design and synthesis of various di-thymine monomers, determination of monomer crystal structures, and characterization of the photoproducts using Nuclear Magnetic Resonance, UV-Visible Spectroscopy, Gel-Permeation Chromatography, and other polymer characterization techniques will be discussed in the presentation.

Catalytic "chemical" depolymerisation of lignin will also be discussed. A new lignin chemical depolymerization was developed using redistribution mechanism with phenols and copper catalysts under mild condition in water. The advantage of the technology is not just producing oligomers as a source of aromatics but also producing monomers for thermoprocessable lignin based polymers - linear lignin thermoplastic polymers for extrusion and compression moulding from depolymerisation.

Friday 6th September 10.30am Dr Stuart Gordon Morphology and tensile properties of bast fibres extracted from cotton stalks  

 Abstract

Bast fibre contained in cotton stalk, a residue from the growth of cotton fibre, is available in very large quantity, estimated more than 15 million tonnes annually. The stalk is currently burnt or buried into soil. In this study, bast fibres were extracted from cotton stalk using a mechanical decortication method. The morphology of single bast fibre, or ultimate, was characterized by an effective diameter and a cell wall thickening factor (maturity) derived from a concentric circle model reconstructed using an image analysis technique. Fibre cells within the same plant are quite consistent in diameter but can vary considerably in maturity depending on their position in the plant. 80% of the bast fibres are contained in the lower half of the stalk where the fibre maturity is high. Cotton bast fibres are as strong as other bast fibres such as jute and hemp and can be used as reinforcement for polymer composite materials.

Friday 6th September 10am Dr Mickey Huson Physical and chemical heterogeneity of carbon fibre.  

 Abstract

Carbon fibre composites have been employed commercially for more than 50 years and their use is growing rapidly in the aerospace and automotive industry. In spite of its commercial success the relationship between the fibre structure and its physical properties are still poorly understood. This presentation reports on a range of physical and chemical techniques that have been used to characterise both polyacrylonitrile and pitch based carbon fibre and highlights the heterogeneity of the fibre. Physical methods include single fibre tensile tests and nano-mechanical indentation whilst chemical analysis involves inverse gas chromatography under finite concentration conditions and confocal Raman spectroscopy. The difficulties in sample preparation, for characterisation of these high modulus, brittle fibres, will also be discussed.

Thursday 5th September 2pm David Larson Atom Probe Seminar - Directions in Atom Probe Tomography  

 Abstract

Atom probe tomography (APT) has been used for over 45 years, "to determine the composition of small volumes of metals, semiconductors, and some ceramics". Although this statement is still true more than a dozen years after it was written, it does not adequately capture the recent expansion and maturation of APT into a variety of applications. Recent innovations in atom probe tomography, including focused ion beam based specimen preparation, have enabled a wide range of new applications. Selected examples of the use of APT in materials analysis will be presented, including areas of photovoltaics, precipitates in metals, and grain boundary analysis in CdTe will be presented. In addition to applications, a brief introduction to the APT method will be given, including specimen preparation, data reconstruction and data analysis.

Thursday 29th August 10.30am Dr. Jiabao Yi Nanostructured Oxide Magnetic Semiconductors for Spintronics Devices  

 Abstract

Oxide based diluted magnetic semiconductor (DMS) has attracted intense interest due to its high Curie temperature. However, the origin of ferromagnetism in oxide based DMSs is in controversy since nonmagnetic doping or pure oxide semiconductors under certain condition can show room temperature ferromagnetism. In this talk, I will give an introduction of our research on DMS based on nanostructured oxide semiconductors. It was found that magnetic element doping, nonmagnetic doping or without any doping could all lead to room temperature ferromagnetism, showing defects may play important role for the room temperature ferromagnetism. We have tried to utilize defects for tuning the magnetic properties. These results demonstrate that nanostructured oxide magnetic semiconductors may be promising for future applications.

Thursday 29th August 3pm H. M. Fan Design of Novel Magnetic Nanoparticle Platform for Biomedical Application  

 Abstract

Magnetic nanoparticle with size, shape and composition tunable properties have been demonstrated great potential for various biomedical applications such as protein/cell separation, biosensor, drug delivery, magnetic resonance imaging (MRI) and magnetic hyperthermia treatment. In particular, biocompatible iron oxide nanoparticles have been considered as a promising contrast/hyperthermia agent for early diagnostics and therapy of cancer. However, the application of these nanoparticles for cancer diagnostics and therapy has been largely hindered by low MR detection sensitivity and low magnetic thermal conversion efficiency. In the past few years, our research effort has focused on the design of novel iron oxide nanostructures with special tailoring surface chemistry to overcome these drawbacks. In this talk, I will introduce, (1) the synthesis and application of hollow structured iron oxide nanoparitlces, especially magnetic vortex-domain nanoring; (2) coating engineering of magnetic nanoparticles, to achieve large MR relaxivity and high specific absorption rate for targeted MR imaging and magnetic hyperthermia treatment of cancer.

Thursday 22nd August 1.30pm Rick VERHOEF Confronted with unwanted nano-columnar self-organisation  

 Abstract

Confronted with unwanted nano-columnar self-organisation in low pressure microwave plasma deposition with a Zirconium Tetra tert Butoxide (ZTB) precursor, we investigate the phenomenon triggering this growth mode in order to control it instead of suffer it. The first step is the determination of the type of fragments arriving on the sample surface, thus experiments were carried out to describe the plasma decomposition process. Scanning different powers in a low pressure RF coil inductive plasma, Fourier Transform InfraRed (FTIR) spectroscopy and Mass Spectrometry (MS) measures where taken. With the help of Density Functional Theory (DFT) simulations we are able to propose a decomposition pathway.

Wednesday 14th August 10am Dirk Hegemann Considering the Plasma/Substrate Interaction during Film Growth  

 Abstract

Film growth in a plasma mainly originates from film-forming species (with often unknown sticking probabilities) arriving at the substrate surface which are accompanied by energetic particles. The energy flux incident on a surface can thus be brought into relation with the flux of the film-forming species yielding the energy and momentum transfer per depositing atom. The influence on film density, functionality, morphology, and adhesion is investigated with respect to the plasma/substrate interaction during film growth. Different examples for functional plasma polymer films, but also metal film growth on polymeric substrates will be discussed being relevant for e.g. tissue engineering, drug delivery, and wearable electronics.

Friday 2nd August 2pm Professor Liming Dai ECR workshop: How to become a great scientist  

 Abstract

Topics include:
- How to build a strong track record
- How to build a successful, multidisciplinary academic career
- How to write a good proposal for competitive grants.

Friday 2nd August 10am Dr Greg Fridman Plasma Medicine Workshop Seminar 3 - Nano- and Micro-second Pulsed Dielectric Barrier Discharge Plasma-assisted Wound Sterilization, Wound Healing, and Tissue Regeneration  

 Abstract

Engineering innovation has produced startling advances in healthcare. Lasers, ultrasound, ionizing and electromagnetic radiation are examples of life saving diagnostics and treatments that originated in engineering disciplines outside of medicine. In this vein, it was demonstrated that atmospheric air plasmas have unique therapeutic effects in human healthcare and hold the promise for new medical diagnostic tools. For example, this presentation will be focused on medically-relevant therapeutic effect of plasmas in wound healing which is based on their ability to deactivate pathogens directly in the wound bed, stop bleeding without damage to healthy tissue, promote cell migration and proliferation into the wound bed, angiogenesis, growth factor release, and other effects leading to the improved wound healing. Mechanisms of plasma-tissue interaction through liquid medium, discharge uniformity, and generation and control of reactive oxygen and reactive nitrogen species in plasma will be discussed in this presentation.

Thursday 1st August 11am Prof Rob Short Plasma Medicine Workshop Seminar 2 - Plasma and its role in treating severe burns and chronic wounds  

 Abstract

myskinTM is a novel advanced therapy for the treatment of severe burns and scalds. Since regulatory approval it has been used in more than 200 times with patients presenting with life threatening burns. myskinTM is also a plasma polymerised surface that is designed to attach and detach cells according to environment. This presentation will cover the early science (1990-1996), the development of myskin (1997-2000), early trials (2000-2004) and its subsequent commercialisation as the most clinically successful burns treatment (NICE, UK).

I will also present some recent studies on the penetration of He jets into biological targets, which support the idea that plasmas can be used to deliver reactive/therapeutic species several hundred micrometers into soft tissues.

Thursday 1st August 10am Prof Bill Graham Plasma Medicine Workshop Seminar 1 - Studies of plasma properties and their interactions with liquid media and with bacteria and cancer cells  

 Abstract

The extent of the future use of plasma medicine on humans will require a full understanding of the underlying physics and chemistry of the plasma and its interaction with the surrounding air and/or liquid media and with the tissue to be treated. In this presentation the combined use of experimental and computer-based simulation to explore the physics of the initiating plasmas and their effluent and the chemistry of their interaction with the surrounding air and/or liquid will be discussed. The focus will be on kHz plasma jets and plasmas produced directly in liquids. Studies of the interaction of plasma effluent with bacteria in both their cellular and biofilm forms and with prostate cancer cells will be also discussed, along with the plasma interaction with isolated components of cells.

Thursday 1st August 9.30am Prof Joe Graffam, Prof Peter Hodgson, Prof Lee Kennedy Plasm Medicine Workshop - opening talks  
Thursday 1st August 2pm Professor Liming Dai HDR workshop: How to become an outstanding HDR student  

 Abstract

Topics include:
- How to develop a research question
- How to write a good paper
- How to communicate with supervisor
- Planning career after graduation
- Networking skills.

Wednesday 31st July 10am Professor Liming Dai Introducing Dai group's work  

 Abstract

Prof. Dai works on multifunctional nanomaterials, optoelectronic macromolecules, biomaterials and bio-mimicking systems. In Prof. Dai's group, vertically-aligned carbon nanotubes and size-/shape-controlled graphene sheets and nanodiamonds are used for various applications, ranging from multifunctional nanocomposite to energy-/bio-related devices. Conjugated macromolecules with well-controlled optoelectronic properties are synthesized for light-emitting diodes, field-effect transistors, batteries, supercapacitor, and photovoltaic cells. Functional nanomaterials, including carbon nanotubes, quantum dots, and DNA thin films, are used as the photon/electron/hole mediators, while a combined experimental and theoretical approach is used to understand and optimize the materials structure and device performance. The potential hazards of nanomaterials to humans (cytotoxicity and genotoxicity) are investigated. Bio-inspired approaches are used for designing and synthesizing materials with functional structures and smart features (e.g. DNA-directed self-assembling, Gecko-foot-mimetic dry adhesion).

Friday 26th July 10.40am Gayathri Devi Rajmohan Improving dye sensitized solar cells using plasma  
Friday 26th July 10.30am Sri Balaji Ponraj Development of novel nanotuboids by plasma nanofabrication for biomedical applications  
Friday 26th July 10.20am Abu Sadek The microstructure of carbon nitride films prepared using energetic plasma deposition  
Friday 26th July 10.10am Zhiqiang Chen Uniform plasma polymerization on carbon nanotubes using a combined plasma mode and stirring system  
Friday 26th July 10am David Rubín de Celis A combined plasma + thermal system to produce doped and nanostructured energy storage materials  
Thursday 25th July 4.40pm SHIROMANI DESINGHEGE ROLE OF DEFORMATION MODES ON THE BENDING BEHAVIOUR OF AZ31 MAGNESIUM SHEET  

 Abstract

Currently the reliable prediction of springback in the bending of magnesium is not possible. Its high material anisotropy leads to significant differences in the material behaviour in tension and compression and this makes it difficult to predict springback with conventional material models. Some basic studies have revealed that the formability of magnesium is linked to the twinning mechanisms present in the material. However, a fundamental investigation of the effect of deformation modes in bending and springback of magnesium has not been performed yet. Further work is needed to investigate the effect of deformation modes on the bending and springback behaviour of magnesium and through that understand the material behaviour of magnesium in the roll forming process.

Thursday 25th July 4.20pm MIKEL GUEMBE MATERIAL LIBRARY DEVELOPMENT USING THE BEND TESTER TO IMPROVE THE ROLL FORMING PROCESS  
Friday 19th July 10am A/Prof. Bernard Rolfe Mystery of incremental bending- using the V-die to simulate roll forming  

 Abstract

Springback is an inevitable phenomenon in sheet metal forming and has been found to reduce with an increasing number of forming steps. In this study the effect of incremental forming on springback is analyzed for DP780 steel. The cyclic hardening characteristics of the DP780 steel are determined by fitting the experimental moment curvature data of a cyclic pure bending test using Abaqus Standard. The change in elastic modulus with pre-strain is also considered in the material model. Using the developed material model a V- die forming process is numerically analyzed for single and multiple-step forming, and the effect on springback determined. The numerical results show that there is a reduction in springback with an increasing number of forming steps, and that this may be due to the plastic strain accumulated in the blank during the sequential loading steps in the bending region. A very good agreement has been achieved between the simulation and the experimental results. The present study seems to offer an effective approach to increase the accuracy of the springback prediction and provide a greater insight into the nature of the springback in the incremental forming process.

Friday 5th July 10am Dr Keith Millington Detecting free radicals in skin exposed to UV radiation  

 Abstract

Exposure of human skin to ultraviolet (UV) radiation is strongly correlated to the incidence of skin cancers in epidemiological studies. The free radicals formed when skin tissue undergoes oxidative stress are implicated in carcinogenesis. In UV-irradiated organic materials, free radicals react with oxygen to form macroperoxy radicals, which then emit weak chemiluminescence. Our unique instrument and protocol for measuring the photo-induced chemiluminescence (PICL) of materials has been used to detect free radicals in bovine stratum corneum and in the skin of hairless mice exposed to UVA radiation for the first time. PICL emission from skin is much weaker than that emitted from the fibrous proteins keratin and collagen, from which its structure is largely comprised. This is probably due to its higher water content, and the presence of the natural antioxidants ascorbate and tocopherol.

Thursday 25th July 4pm JOSU AZKUNE NUMERICAL AND EXPERIMENTAL ANALYSIS OF THE ROLL FORMABILITY OF ALUMINIUM FOAM SANDWICH PANELS  
Tuesday 21st May 11.30am Xiumei Mo Electrospinning Nanofibers for Tissue Engineering  

 Abstract

In our research different nanofibers have been fabricated by electrospinning for varied tissue regeneration. Firstly, chitosan and collagen in hexafluoroisopropanol (HFP) and Trifluoroacetic acid mixture solution were electrospun into nanofibers. The mechanical testing showed the tensile stress and strain of chitosan-collagen nanofibers varied based on the chitosan content. A elastic behavior was got when chitosan content was 20% with the tensile strength of 2MPa and elongation at break of 80%.That nanofiber membrane was used for skin regeneration for the 1x 1.5cm defect on the back of SD rat. The wound area was healed in the 3rd weeks, which is better than the area covered only by gauze.

Secondly, chitosan collagen and poly(L-lactide-co-e-caprolactone)(P(LLA-CL)) in HFP solution were electrospun into nanofibers where chitosan and collagen kept the ratio of 1:4. The tensile strength of the chitosan-collagne-P(LLA-CL) nanofibers reached the highest of 11MPa at the chitosan and collagen content of 25% and the elongation at break is 290%. Co-axial electrospining was used to prepare the core shell nanofibers with heparin as core and chitosan-collagen-P(LLA-CL) as shell. Heparin continually released from the nanofibers for 45days, and kept the antithrombotic function. Haprin-chitosan-collagne- P(LLA-CL) core-shell nanofibers were fabricated into tube scaffold with the inner diameter of 3mm which were implanted in dog femoral artery 3cm defect and kept patency for one and a half year.

Thirdly, silk fibroin (SF) and P(LLA-CL) in HFP solution were electrospun into nanofibers. The tensile strength of the SF-P(LLA-CL) nanofibers reached the highest of 10MPa at the SF content of 25% and the elongation at break is 280%. The degradation speed of SF-P(LLA-CL) nanofibers decreased with the increasing of SF content. When SF content is 25% the weight loss is 30% after soaked the nanofiber in water for 6 month. This SF-P(LLA-CL) nanofibers was used as nerve conduit for rat sciatic nerve regeneration to comparing with P(LLA-CL) nanofiber conduit. Both regenerated the 15mm nerve within 4 weeks, but the nerve function, nerve conduction velocity, increased with the healing time. Nerve conduction velocity were higher for SF-P(LLA-CL) nanofiber conduit than that for P(LLA-CL) nanofiber conduit, that means silk fibrin can enhance the nerve regeneration.

Friday 17th May 10am Nahid Iranipour Novel Organic Ionic Plastic Crystal Electrospun Nanofibre Composites: Transport behavior, Battery Application  

 Abstract

Environmental concerns due to excessive employment of technologies based on fossil fuel consumptions are increasing rapidly. Research looking for new technologies to mitigate the global problem by developing technologies using renewable energy sources is becoming increasingly important. A critical requirement in this regard is the efficient storage of energy. Lithium batteries exhibit the highest volumetric and gravimetric energy density and are appropriate candidates. However, there are several disadvantages in their application. The current commercial electrolytes are flammable toxic liquids and there is a significant limitation in their application due to safety issues arising from phenomenon such as overheating, overcharging and physical abuse of the device. Furthermore, the liquid electrolytes do not have the mechanical strength to suppress short circuiting due to dendrite growth of lithium electrode during cycling of the device.

Friday 10th May 10.30am Jingsi Jiao A numerical study on web-warping of flexible roll forming  
Friday 10th May 10am Dr Stuart Lucas The CSIRO Fibre Science and Materials Performance Research Program Explained  

 Abstract

Dr Stuart Lucas is the Research Program Leader for CSIRO's Fibre Science and Materials Performance Research Program within the division of Materials Science and Engineering. This research capability comprises of 100 research staff the majority of whom have recently relocated to the Waurn Ponds Campus of Deakin University as part of the Australian Future Fibre Innovation Centre (AFFRIC). The FSMP program conducts basic and applied research to promote profitable and sustainable fibre and fibrous structure industries, develop new products and improve production and processing efficiencies along with providing NATA accredited testing services to the textile and building industry.

Friday 3rd May 11.30am Facundo Nahuel Varela Monitoring steel corrosion under disbonded pipeline coatings  

 Abstract

Corrosion under disbonded coatings is a major issue for the pipeline industry and a particular challenge for the actual corrosion assessment and monitoring tools. In this work, a novel approach is used to develop a new corrosion probe specifically designed to simulate the conditions present under a disbonded coating and measure corrosion rates and current distribution gradients. The results presented confirmed the feasibility of the concept and provided valuable information for further work.

Friday 19th April 10.15am Hassan Zaid The influence of Nb addition on the mechanical properties of high Mn-TWIP steels  

 Abstract

Car manufactures have been forced by legal requirements (environment regulation, safety, etc.) to develop and use high performance steels, these include high strength low alloy (HSLA) and advanced high strength (AHSS) steels, such as dual phase steel (DP), transformation induced plasticity (TRIP), and twinning induced plasticity (TWIP) steels. The last of these is a class of promising high manganese austenitic steels which have shown both high strength and ductility. The strength provides structural load support and down gauging opportunity, while the ductility facilitates manufacture and permits sustained energy absorption in a crash. Due to these promising material properties, there is an increasing interest in understanding and improving these grades. Two particular problems are their relatively low yield strength compared to other AHSS grades, and the high forming/rolling loads encountered in manufacture. The present study examines the potential to use Niobium (Nb) addition to the high Mn-TWIP steel to improve the yield strength and create opportunity for novel annealing treatments.

Friday 19th April 10am Sri Ponraj Development of Novel Nanotuboids by Plasma Nanofabrication for Biomedical Applications  

 Abstract

This project aims to produce biologically inspired hybrid nanostructures called "nanotuboids" by plasma nanofabrication. The nanotuboid is an assembly of gold nanoparticles (GNPs) with short boron nitride nanotubes (BNNTs) or boron nitride nanocups (BNNCs). This will serve as a model for bio-medical applications such as bio-imaging, drug delivery, biosensors and tissue engineering. BNNTs, structural analogues of carbon nanotubes, have high strength, superior thermal and chemical stability, a uniform electronic band gap and a high piezoelectric response whereas BNNCs, hollow-cup like structures, have high surface areas, useful optical properties and low effective densities. Producing short BNNTs or BNNCs is essential for improved solubility and process ability. However, the method should avoid the use of toxic chemicals or lengthy sonication which has previously been used to produce short BNNTs or BNNCs. Moreover, the fabrication of nanotuboids suitable for biomedical applications requires controlled surface functionalization of short BNNTs or BNNCs, and integration of GNPs. To address these challenges, our approach involves the use of a nanosecond pulsed atmospheric pressure plasma system (NPAPP) in liquid. The major advantage of using NPAPP is that it can generate a combined pulsed electric field, UV radiation, O3 and free radicals in one go. Furthermore, NPAPP can be operated at atmospheric pressure and ambient temperature, so can be easily scaled up to an industrial level. A three step fabrication method has been developed to produce nanotuboids using NPAPP as follows: 1. Synthesis of short BNNTs and BNNCs 2. Surface functionalization of short BNNTs and BNNCs 3. Assembly of GNPs onto the functionalized short BNNTs and BNNCs

Thursday 18th April 11.30am Jelena Rnjak-Kovacina (a)Tunable silk constructs for soft tissue engineering: the effect of silk molecular weight, concentration and crystallinity on lyophilised silk sponge properties
(b)Channelled silk scaffolds: a versatile platform for 3D critical size construct tissue engineering  

 Abstract (a)

The general approach for engineering tissue equivalents is to co-ordinately combine relevant cell types with iophysical/chemical cues on an appropriate scaffolding material. The scaffolding material plays a significant role in modulating cell behavior and tissue formation. To achieve desired cell and tissue function, scaffold properties, including stiffness, biodegradation rate, porosity, and surface chemistry must be optimised. Silk fibroin is an exemplary scaffolding material because its material properties can be highly tuned while exhibiting excellent cell compatibility with no adverse immune responses in vivo. Silk scaffolds have traditionally been aimed at hard tissue engineering (TE) due to its robust mechanical properties and slow degradation rates. Lyophilised silk sponges are now emerging as a particularly promising scaffolding platform for soft TE, as their properties can be fine-tuned toward low stiffness, fast degrading constructs. In this study we have investigated the effects of silk molecular weight, concentration and crystallinity (beta-sheet content) on the mechanical, degradation, pore morphology and scaffold integrity properties of lyophilised silk sponges. These studies reveal that silk molecular weight is a strong indicator of scaffold structural integrity, where only high molecular weight silk allows construction of stable 3D constructs at low silk concentration. Silk crystallinity is a strong indicator of scaffold degradation both in vitro and in vivo where lower crystallinity correlates with faster scaffold degradation. Silk concentration is a particularly strong driver of scaffold mechanical properties, where scaffolds of high concentration (4-6% wt/v) possess significantly higher stiffness compared to lower concentration scaffolds. Uniquely, a novel set of silk sponges with very low concentration (0.5%-1% wt/v silk) were successfully cast in this study using high molecular weight silk (5 min and 10 min boil times). These constructs can be cast with stiffness <1 kPa while maintaining stable 3D structure and ease of handling, which is particularly important for engineering soft tissues containing contractile cells such as cardiomyocytes.

 Abstract (b)

The primary obstacle in engineering tissue equivalents is the diffusion limit of oxygen and nutrients. Constructs that exceed critical dimensions (several hundred micrometers) are prone to necrosis at the core of the construct and ultimately fail to integrate with host tissue due to lack of blood perfusion. Vascularisation within a critically-sized tissue construct does not occur within a sufficient time frame to supply the entire construct with the necessary oxygen and nutrients. Therefore, there is a significant demand for efficient and reproducible oxygen and nutrient delivery throughout the bulk of critically-sized engineered tissues. We report the development and characterisation of versatile silk-based scaffolds with highly tunable properties for engineering of a range of critically-sized tissue constructs. These scaffolds can be assembled with relevant dimensions without the need to stack scaffold pieces and contain an array of hollow channels that 1) improve oxygen and nutrient delivery to critically-sized constructs, 2) allow scaffold pre-vascularisation with endothelial cells, 3) support cell compartmentalisation (eg. endothelial cells lining the channel periphery and hMSCs in the scaffold bulk), 4) allow localised bioactive factor presentation and delivery (eg. laminin, collagen, VEGF) and 5) improve construct integration and vascularisation in vivo compared to non-channelled controls. Unlike several other reported channelled scaffolds, the current system allows reproducible control over channel properties, including channel diameters, wall-to-wall spacing, wall morphology and localisation of loading of bioactive compounds. In addition, the scaffold bulk surrounding the channels is biodegradable, cell compatible and can take on a variety of pore sizes, pore morphologies (random and aligned pores) and mechanical properties to support engineering of a range of tissue types. We are now collaborating with a number of groups to test the utility of this platform in cardiac and skeletal muscle, bone, kidney, adipose tissue and blood-brain barrier tissue engineering.

Wednesday 17th April 2pm Akbar Abvabi Development of an Inverse Routine to Predict Residual Stresses in the Material Based on a Bending Test  

 Abstract

Bending and reverse bending are the dominant material deformations in roll forming, and hence property data derived from bend tests could be more relevant than tensile test data for numerical simulation of a roll forming process. Recent investigations have shown that residual stresses change the material behavior close to the yield in a bending test. So, residual stresses introduced during prior steel processing operations may affect the roll forming process, and therefore they need to be included in roll forming simulations to achieve improved model accuracy. Measuring the residual stress profile experimentally is time consuming and has limited accuracy while analytical models that are available require detailed information about the pre-processing conditions that is generally not available for roll forming materials. The main goal of this study is to develop an inverse routine that determines a residual stress profile through the material thickness based on experimental pure bend test data. A numerical model of the skin passing (temper rolling) process is performed to introduce a residual stress profile in DP780 steel sheet. The skin passed strips are used in a pure bending simulation to record moment-curvature data and this data is then applied in an inverse analysis to predict the residual stress profile in the material. Comparison of the residual stress profile predicted by the inverse routine with that calculated by finite element analysis (FEA) indicates an inverse approach combined with pure bend test may present an alternative to predict residual stresses in sheet metals.

Friday 12th April 10.30am Peidong Wu (McMaster University) Lattice strain evolution and twinning-detwinning in Mg alloy ZK60A under cyclic loading  
Friday 12th April 10am Tom Stoughton (General Motors) Forming Limit Diagrams in Anisotropic Metals  
Thursday 11th April 4pm Bevis Hutchinson Metals - Chemistry and Mechanics  

 Abstract

Perhaps the most usual thing for a metallurgist when investigating a new material is to get a full chemical analysis. This is useful but it usually tells many things we are not interested in and omits many others that are important for the understanding of important properties like:
- Strength
- Toughness
- Stability
- Corrosion
I will discuss why high accuracy and high precision are over-rated virtues in most cases. Good comparative data are often more useful than accurate absolute values.

Frequently, the most important thing to know is the local dispersion of different elements in a steel or non-ferrous alloy. These may be segregations remaining after casting or segregations at grain (crystal) boundaries or dislocations that dramatically influence process conditions and final properties of the materials - both for the better and for the worse.

Many alloy elements such as Nb or Al are most influential when precipitated in second phases like NbC or AlN in steels. Then we need to know how much of the element is dissolved in the iron matrix and how much is in the form of particles. This may be possible with electrolytic dissolution and filtering. Also, the sizes of the particles are very important so we combine chemical and microstructure analysis (micro-chemistry) using electron-optical methods such as SEM or STEM with EDS, WDS and/or EELS spectroscopy. These approaches, however, fail when the alloy contents are small or the particles are too densely distributed.

Alternative methods have been developed that overcome these limitations. Examples are mechanical spectroscopy, thermo-electric power measurement and atom probe tomography, as applied to chemical analysis. Local trace contents of impurities or dopants require techniques based on mass spectroscopy such as SIMS and LA-ICP-MS.

The talk will be illustrated with examples of the various methods and their applications.

Thursday 11th April 10am Dr Anders Engstrom and Dr Qing Chen Thermocalc  

 Abstract

Thermo-Calc Software is one of the worlds most experienced suppliers in the segment of computational simulations within materials development and research and Thermo-Calc Software has recently been selected as an exceptional contributor to innovation by Advanced Materials & Processes.

Wednesday 27th March 2pm Akira Uedono Characterization of open volumes in amorphous materials using positron annihilation  

 Abstract

Positron annihilation is a powerful technique for evaluating the properties of open volumes and vacancy-type in amorphous and crystalline materials. With this technique, detectable defects are monovacancy to open pore (<100 nm3). The detection efficiency is high (>1015 cm?3 for a monovacancy), and there is no restriction of sample temperature or conductivity. Using monoenergetic positron beams, the detection of open volumes in thin films (?2 nm) and subsurface region (0~1 ?m) is possible. In the presentation, basics of positrons and its application to polymers, metal oxides, and porous films will be presented.

Tuesday 19th March 10am Professor Hisanao Usami Development of multichannel reactors for large scale photochemical reaction  

 Abstract

Photochemical reactions of concentrated solutions have been successfully achieved using microchannel reactors. In traditional photochemical reaction systems, incident light should be almost absorbed or scattered at incident window, walls of the glass vessels, or surface of the solution. In the microchennel reactors, the incident light penetrates to the bottom of the channels filled with the concentrated or turbid solutions because the path length for the micro channel is as much as 200 micrometers for the typical reactors.

We have developed a novel microchannel reactor with many channels of porous glassware nesting each other. The porous glassware plays a role of waveguides through which the incident light is successfully delivered to each reaction site on the innerwall of the microchannels. Substrate solution can pass through the channels, so that the waveguide of the incident light can completely separated from the channels for the substrate solution. The condition should be necessary to accommodate large amount of highly concentrated or turbid solutions with high absorbance and/or light scattering. Some examples of photochemical reactions, such as trans-cis photoisomerizations of aromatic olefins and photocatalytic decomposition of organic dyes will be presented. Number of photons penetrated into the microchannel reactors were measured using a chemical actinometer. Quantum efficiency for each photochemical reactor will also be discussed.

Wednesday 13th March 10am Dr Maria Bellantone Springer Seminar - Scholarly Publishing Made Easy  

 Abstract

How can you increase your chances of success in scholarly publishing? Publishers are there to enable scientists to certify (through the peer-review process), record and disseminate their results to their research community across the world. The spectrum of scientific literature extends from journals to books and further to encyclopedias and databases. This talk will cover the different kinds of books and journals that are available to academics to publish their work. It will include a range of practical advice, examples and tips for authors. It will reveal how things work within Springer and what are the publisher's future plans. While the core aim of publishing hasn't changed much, the digitization of the literature and the widespread availability of digital networked devices has brought about important changes and new challenges to the way publishers do their job. The formats that are now required have multiplied and the methods by which contents are distributed have evolved, with repercussions also on the authors. Moreover, just like the authors, publishers have to adapt to comply with new policies, such as the Open Access mandates put in place by numerous funding agencies, such as the ARC and the NHMRC. This talk will address the solutions that Springer is offering to scientists and their institutions to facilitate the implementation of these policies.

Tuesday 5th March 11am Professor Johanna Buchert VTT research of cellulosic fibres- from molecular level to final products 

 Abstract

The overall topic of my research is enzyme-aided modification of biomass components for different industrial end-uses. I have been investigating the impact different hydrolytic and oxidative enzymes in pulp and paper, textile fibre and food processing. Part of my research has focused on discovery of new enzyme activities. Current research is focused on valorisation of different forest and food processing by-products to value added chemicals and ingredients. Altogether I have published about 150 peer-reviewed publications.

Friday 15th February 10am Dr. Abu Sadek Highly oriented nanomaterials for photovoltaic and sensing device application 

 Abstract

Nanomaterials possess desirable optical and/or electronic properties which have the potential to make a major impact in a range of important areas including clean energy generation and sensing environmental pollutants and bio-chemical species. In this talk, an overview of my previous research achievements in the field of nanotechnology will be given. Employing physical vapour deposition, electro-chemical and chemical methods highly oriented arrays of titania nanotubes, zinc oxide nanorods, molybdenum trioxide nanoplates and tungsten trioxide nanoplatelets have been directly fabricated on transducer substrates. These nanomaterial based substrates were used to develop novel sensors to detect environmental pollutants and hazardous gases. The developed sensors can detect at very low concentrations (ppb level) with high sensitivity and have short response and recovery time (~10 s). Finally an outline of my current research activities at Deakin will be given.

Friday 8th February 2pm RAY H. BAUGHMAN High Performance, Electrolyte-Free Torsional and Tensile Carbon Nanotube Hybrid Muscles 

 Abstract

New electrolyte-free muscles that provide fast, high-force, large-stroke torsional and tensile actuation are described, which are based on guest-filled, twist-spun carbon nanotube yarns. Actuation of hybrid yarns by electrically, chemically, and photonically powered dimensional changes of yarn guest generates torsional rotation and contraction of the helical yarn host. Over a million reversible torsional and tensile actuation cycles are demonstrated, wherein a muscle spins a rotor at an average 11,500 revolutions/minute or delivers 3% tensile contraction at 1,200 cycles/minute. This rotation rate is 20 times higher than previously demonstrated for an artificial muscle and the 27.9 kW/kg power density during muscle contraction is 85 times higher than for natural skeletal muscle. Applying well-separated 25 ms pulses yielded 0.104 kJ/kg of mechanical energy during contraction at an average power output of 4.2 kW/kg (four times the power-to-weight ratio of common internal combustion engines). Demonstrations include torsional motors, contractile muscles, and sensors that capture the energy of the sensing process to mechanically actuate. Improved control and large rotational actuation, along with long cycle life and tensile contractions up to 9%, suggest the use of these yarn actuators in medical devices, robots, and shutters, for which shape memory alloys are currently employed, as well as extension to microvalves, mixers, smart phone lenses, positioners and even toys and intelligent textiles.

Friday 8th February 10am Andreas Kupke The effect of microstructure on the Bauschinger effect and the change in Young's Modulus with plastic deformation of dual phase steel (DP780) 

 Abstract

In recent years, advanced high strength steels (AHSS) have been used in a wide range of automotive applications; the most common high strength steel used in automotive parts is the dual-phase (DP) steel. Previous research has mainly focused on the effect of microstructure on parameters such as uniform elongation, material hardness and material strength of DP steel. However, for the forming of DP steel the effect of microstructure on formability and fracture behavior, Bauschinger effect and the change in Young's modulus with pre-strain are of interest. To investigate the effect of microstructure the DP steel (DP780) was heat treated to generate five different microstructure conditions. Bending tests as well as tension - compression tests were performed to investigate the influence of the microstructure on the Bauschinger effect. The Young's Moduli were investigated by performing loading - unloading tests on a standard tensile tester. This talk will present an overview of the results generated during this investigation.


For further information, please contact - Christine Rimmer ph: +61 3 5227 3241

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16th September 2013