Effects of tool positioning on joint interface microstructure and fracture strength of friction stir lap Al-to-steel welds

Friction stir lap welding (FSLW) experiments have been conducted to study the effects of tool positioning on microstructures formed in the Al-to-steel interface region and on joint strength, defined as maximum applied force over the width (F m/w s) of the test sample, of the welds. Various pin positioning and speed conditions were used in the FSLW experiments followed by microstructure examination on the interface regions and tensile-shear testing on the welds, including an examination on crack propagation in mixed stir zone. It was found that when the pin was close to the bottom steel piece, Al-to-steel reaction occurred resulting in intermetallic outbursts formed along the interface. This represents the case of incomplete metallurgical joint. When the pin was lowered to just reach the steel, a thin and continued interface intermetallic layer formed. Evidences and consideration on growth kinetics have suggested that the layer could only remain thin (≤2.5 μm) during FSLW. This layer could bear a high load during tensile-shear testing and the adjacent aluminium deformed and fractured instead. The resulting F m/w s was high. When the pin penetrated to steel, F m/w s reduced due to brittle fracture being dominant inside mixed stir zone. Evidences have shown that the amount of penetration and speed condition during FSLW do not have large effects on F m/w s.

Re-positioning Australia's international education in global knowledge economies : implications of shifts in skilled migration policies for universities

In recent times, many key host nations have made it easier for foreign graduates to migrate after graduation. These students are often considered ideal migrants, possessing local qualifications along with a degree of acculturation, language skills and, in many cases, relevant local work experience. For the student, the opportunity to obtain international work experience adds to the appeal of the overseas study experience and enhances the graduate skills necessary to compete in the global labour market. This paper examines recent changes to migration policy in Australia affecting the post-study work entitlements of international students studying at Australian universities and explores the underlying rationale and consequences of the recent changes in policy direction. An examination of migration policies in the United States, United Kingdom, New Zealand and Canada indicates that recent changes to skilled migration policy in Australia, along with bleak economic conditions in a number of key host countries, has opened up opportunities for Australia to re-position itself favourably.

Defining sub-regions in locally sparsified compressive sensing MRI

Magnetic Resonance Imaging (MRI) is an important imaging technique. However, it is a time consuming process. The aim of this study is to make the imaging process ef?cient. MR images are sparse in the sensing domain and Compressive Sensing exploits this sparsity. Locally sparsi?ed Compressed Sensing is a specialized case of CS which sub-divides the image and sparsi?es each region separately; later samples are taken based on sparsity level in that region. In this paper, a new structured approach is presented for de?ning the size and locality of sub-regions in image. Experiments were done on the regions de?ned by proposed framework and local sparsity constraints were used to achieve high sparsity level and to reduce the sample set. Experimental results and their comparison with global CS is presented in the paper.

Global positioning systems : altered representations of place

Global Positioning Systems: altered representations of place, presents an exegesis from the practice led research submitted for the degree of Master of Fine Art at the Victorian College of the Arts. The thesis proposes a particular understanding of altered states of consciousness that is relevant to my practice.  This is outlined by Charles Tart and supported by the Altered States of Consciousness Consortium and explores a psycho-aesthetic experiences and does not involved transcendental states or spiritual associations. These experiences are transformed by an exhaustive application of digital technologies, where mosaic-like complexity emerges that induces sustained disorientation and surrounds a viewer in an immersive space.

Global positioning systems: altered representations of place

Solo exhibition of Master of Fine Art practice

Global positioning systems: Middle Eastern & Australian landscapes

A solo exhibition held at the Australian Embassy Kuwait in 2009, explores the similarities and differences of interior and exterior landscapes of Kuwait, Oman, the UAE, Jordan and Australia. The work makes reference to the GPS coordinates of each location as a means of interrogating the position of the artist within each realm.

Simulation and analysis of a sub-wavelength grating based multilayer surface plasmon resonance biosensor

This paper presents a subwavelength grating based multilayer surface plasmon resonance biosensor (SPRB) which includes a periodic array of subwavelength grating on top of a layer of graphene sheet in the biosensor. The proposed biosensor is named grating-graphene SPRB (GG-SPRB). The aim of the proposed multilayer structure is to improve the sensitivity of the SPRB through monitoring of the biomolecular interactions of DNA hybridization. Significant sensitivity improvement is obtained for the GG-SPRB compared with the conventional SPRB. The result of the numerical investigation of the GG-SPRB is presented and compared with a theoretically developed multilayer matrix formalism, and a good agreement has been observed. In addition, an optimization of the grating dimensions including volume factor, grating depth, grating angle, grating period, and grating geometry (e.g., rectangular, sinusoidal and triangular) is presented. The outcome of the investigation presented in this paper identifies desired functioning conditions corresponding to the best design parameters for the GG-SPRB.