http://espace.library.uq.edu.au/ The University of Queensland en Fez http://blogs.law.harvard.edu/tech/rss http://espace.library.uq.edu.au/view/UQ:130119 The present study is concerned with analysis of a specific feature of the modified quasichemical solution model (MQSM). The analyzed feature is typical for binary solutions with very strong short-range ordering. As demonstrated, a solid compound whose composition coincides with that of maximum ordering in the liquid is required for reasonable representation of phase equilibria in such a system. The limiting slopes of the liquidus curve of the compound are calculated. As a demonstrational example, the thermodynamic model for the system K2O-SiO2 with the MQSM for the liquid phase is re-optimized. The new parameters of the thermodynamic model fit the available experimental data and represents reasonable phase relations for the entire compositional range. (c) 2007 Elsevier B.V. All rights reserved. 2008-02-18T00:00:00Z Saulov, D.N. http://espace.library.uq.edu.au/view/UQ:295033 2013-03-27T12:50:02Z Shelley, T. J. og Liew, C. K. http://espace.library.uq.edu.au/view/UQ:176897 2009-04-17T00:00:00Z Bassan, J. og Knights, P. http://espace.library.uq.edu.au/view/UQ:148523 2008-06-06T00:00:00Z Meyer, T. og Tadic, D. http://espace.library.uq.edu.au/view/UQ:149474 2008-06-06T00:00:00Z Smith, P. N. http://espace.library.uq.edu.au/view/UQ:100068 2007-08-23T00:00:00Z Kizil, M. S. http://espace.library.uq.edu.au/view/UQ:177206 2009-04-22T00:00:00Z Shafiee, S. og Topal, E. http://espace.library.uq.edu.au/view/UQ:193087 In this paper, we apply the incremental EM method to Bayesian Network Classifiers to learn and interpret hyperspectral sensor data in robotic planetary missions. Hyperspectral image spectroscopy is an emerging technique for geological investigations from airborne or orbital sensors. Many spacecraft carry spectroscopic equipment as wavelengths outside the visible light in the electromagnetic spectrum give much greater information about an object. The algorithm used is an extension to the standard Expectation Maximisation (EM). The incremental method allows us to learn and interpret the data as they become available. Two Bayesian network classifiers were tested: the Naive Bayes, and the Tree-Augmented-Naive Bayes structures. Our preliminary experiments show that incremental learning with unlabelled data can improve the accuracy of the classifier. 2010-01-18T00:00:00Z Wang, X. R. og Brown, A. J. og Upcroft, B. http://espace.library.uq.edu.au/view/UQ:193207 2010-01-19T00:00:00Z Wang, X. og Kumar, S. og Kaupp, T. og Upcroft, B. og Durrant-Whyte, H. F. http://espace.library.uq.edu.au/view/UQ:201893 2010-04-07T00:00:00Z Bastock, M. og Flynn, B. og Knights, Peter http://espace.library.uq.edu.au/view/UQ:8024 The macroscopic chemistry method [Lilley and Macrossan, Phys. Fluids, v16, p2054, 2004] was developed to model non-equilibrium chemically reacting flows with the direct simulation Monte Carlo (DSMC) method. The macroscopic method uses kinetic temperatures, calculated from mean particle energies, to calculate reaction rates. For strongly non-equilibrium flows, it is possible the macroscopic method might ignore reactions that should result from high-energy collisions that occur in the high-energy tail of the collision energy distribution. This could result in a "rate-reducing" effect relative to conventional collision-based DSMC chemistry models that perform reactions based on the energy of each individual collision. This effect would be most pronounced for reactions with low activation energy. We test for this possible rate-reducing effect in the macroscopic method by calculating the hypersonic flow of dissociating oxygen, which has a low dissociation energy, over a blunt cylinder. The results are compared to those obtained with the most common collision-based DSMC chemistry method, the total collision energy model. The results are in close agreement and we find no rate-reducing effect with the macroscopic method. This result extends the scope of the macroscopic method, and demonstrates its potential for modelling reacting non-equilibrium gas flows with the DSMC method. 2006-08-08T00:00:00Z Lilley, C. R. og Macrossan, M. N. http://espace.library.uq.edu.au/view/UQ:84210 2007-08-14T00:00:00Z Macrossan, M. N. http://espace.library.uq.edu.au/view/UQ:60371 Aluminium alloys that contain Si, Mg, Fe, Mn and/or Cu usually contain one or more types of intermetallic phases that are not readily distinguishable in the microstructure by conventional microscopy methods. It has thus been a challenge to develop a method that will unambiguously identify them. A practical approach has been developed that is based on an inherent linear relationship revealed for the overall distribution of any two elements in a precipitate/matrix geometry and the first-order approximation of electron probe microanalysis (EPMA) results. Application of this approach to a direct chill cast 6082 alloy is demonstrated, and its major limitations are discussed. 2007-08-14T00:00:00Z Ma, Q. og Taylor, J. A. og Yao, J. og Couper, M. J. og St John, D. H. http://espace.library.uq.edu.au/view/UQ:194837 An analytical model is proposed to predict the time varying thermal conductance at the casting-die interface during solidification of light alloys during High pressure Die Casting. Details of the topography of the interface between the casting and the die are included in the model through the inclusion of solid surface roughness parameters and the mean trapped air layer at the interface. The transitory phase of the interfacial thermal conductance has been related to the degradation of contact as solidification progresses through the casting thickness. The modelled time varying thermal conductance showed very good agreement with experimentally determined values for different alloy compositions and casting geometries. The analysis shows that the parameters that govern the thermal conductance. are different for the first stage of contact compared to the second stage of contact when the alloy begins to solidify 2010-02-07T00:00:00Z Hamasaiid, A og Dour, G og Loulou, T og Dargusch, MS http://espace.library.uq.edu.au/view/UQ:198164 An XPS investigation was carried out on the surface film formed by exposure to high-purity water. on mechanically polished Mg and the two Mg-Al intermetallic compounds: Al3Mg2 and Mg17Al12, The result for mechanically polished pure Mg indicates that a film of MgO covered by a Mg(OH)2 layer, formed by the reaction of MgO with water vapour in the air. On immersion in distilled water, this film was hydrated to a duplex film with an inner MgO layer next to the Mg metal and an external porous layer of hydroxide. For both intermetallics, there was preferential dissolution of magnesium from the mechanically ground surface and also during aqueous immersion. After immersion, there was a 10 nm thick, stable film on the surface; the film composition on Al3Mg2 Was AlMg1.4O0.2(OH)(5.4) that on Mg17Al12 was AlMg2.5(OH)(8). 2010-03-08T00:00:00Z Liu, M. og Zanna, S. og Ardelean, H. og Frateur, I. og Schmutz, P. og Song, G.L. og Atrens, A. og Marcus, P. http://espace.library.uq.edu.au/view/UQ:184788 This paper reports both the theoretical development and the numerical verification of a practical wavelet-based crack detection method, which identifies first the number of cracks and then the corresponding crack locations and extents. The value of the proposed method lies in its ability to detect obstructed cracks when measurement at or close to the cracked region is not possible. In such situations, most nonmodel-based methods, which rely on the abnormal change of certain indicators (e.g., curvature and strain mode shapes) at or close to the cracks, cannot be used. Most model-based methods follow the model updating approach. That is, they treat the crack location and extent as model parameters and identify them by minimizing the discrepancy between the modelled and measured dynamic responses. Most model-based methods in the literature can only be used in single- or multi-crack cases with a given number of cracks. One of the objectives of this paper is to develop a model-based crack detection method that is applicable in a general situation when the number of cracks is not known in advance. To explicitly handle the uncertainties associated with measurement noise and modelling error, the proposed method uses the Bayesian probabilistic approach. In particular, the method aims to calculate the posterior (updated) probability density function (PDF) of the crack locations and the corresponding extents.The proposed wavelet-based crack detection method is verified and demonstrated through a comprehensive series of numerical case studies, in which noisy data were generated by a Bernoulli–Euler beam with semi-rigid connections. The results show that the method can correctly identify the number of cracks even when the crack extent is small. The effects of the number of cracks and the crack extents on the results of crack detection are also studied and discussed in this paper. 2009-10-12T00:00:00Z Ng, C. T. og Lam, H. F. http://espace.library.uq.edu.au/view/UQ:96637 2007-08-24T00:00:00Z Yeomans, S.R. og Atrens, A. http://espace.library.uq.edu.au/view/UQ:294912 A number of the major metalliferous mining companies with interest in caving mining methods are currently at different stages of design and planning of what could arguably be classed as a new generation of much larger scale block and panel cave operations referred to by some as Supercaves. Some of these future operations, expected to be producing in the next 5 to 10 years, are in deposits or geological systems which are located at much greater depths than current, in even more challenging geotechnical and therefore mining environments characterised by strong rock masses i.e. primary rocks, and in higher stress regimes. These conditions, combined, are likely to impose greater technical and mining challenges and therefore risks in terms of the caving processes (caving mechanics including seismicity), cave establishment (ramp-up time) and subsequent production (fragmentation and stability issues). In order to mitigate such potential risks, rock mass preconditioning techniques are increasingly being integrated by some companies into mine design and planning even for current “conventional” cave mining geometries. To date preconditioning using hydraulic fracturing in particular has been implemented and reported to produce measurable and positive outcomes even though there is still on-going debate on the real impact of preconditioning with respect to cave mining performance. This paper describes a proposed methodology for evaluation of the preconditioning by blasting exercise at the Newcrest Mining Limited’s Cadia East (CE) panel cave mine. This was part of a full scale “blasting” preconditioning trial conducted as the first of a series of planned panel caves in the Cadia East (CE) mining complex in New South Wales, Australia. The full scale trials formed part of a technology exchange agreement between Newcrest Mining Ltd. and Codelco-Chile. This paper describes a proposed methodology for evaluation of the preconditioning by blasting. The methodology uses a numerical model of the blasting process designated as the Hybrid Stress Blasting Model or HSBM which in its current form of development is best described as an advanced research tool. However the HSBM has unique features which qualify it as an effective tool to quantify the level and extent of damage around blastholes detonated in a fully confined environment (rock mass). The in-situ stress state of the blast volume is taken into account including the actual blasthole timing and initiation uses. The trials incorporated the use of acoustic televiewer (ATV) images of borehole walls, tri-axial accelerometers, cross-hole seismic tomography and acoustic emission tri-axial tests of core samples collected pre and post blasting. This was to also provide data to quantify the effect of the confined blasting preconditioning. This paper only focuses on the application of the HSBM model as a viable pathway for the quantification of preconditioning by blasting. The actual data to quantify the impacts of the preconditioning were not available at the time of submission of this paper. 2013-03-26T13:36:11Z Catalan, A. og Onederra, I. og Chitombo, G. http://espace.library.uq.edu.au/view/UQ:224804 2010-12-16T00:00:00Z Eghbal, Mehdi og El-Araby, E. E. og Ito, Yoichi og Zoka, Yoshifumi og Yorino, Naoto http://espace.library.uq.edu.au/view/UQ:78608 A structurally based viscosity model for fully liquid silicate slags has been proposed and applied to the Al2O3-CaO-'FeO'-SiO2 system at metallic iron saturation. The model links the slag viscosity to the internal structure of melts through the concentrations of various anion/cation structural units (SUs). The concentrations of structural units are equivalent to the second nearest neighbor bond concentrations calculated by the quasi-chemical thermodynamic model. This viscosity model describes experimental data over the entire temperature and composition range within the Al2O3-CaO-'FeO'-SiO2 system at metallic iron saturation and can be extended to other industrial slag systems. 2007-08-15T00:00:00Z Kondratiev, A. og Jak, E. http://espace.library.uq.edu.au/view/UQ:199410 A theoretical description of a fuel-air mixing loss model is derived from rst principles and placed within a quasi-one-dimensional scramjet combustor code. This code is then compared with experimental and multidimensional computational uid dynamics results from the literature. Quasi-one-dimensional results compare well against published data and show that this approach is suitable for conceptual design and vehicle performance studies. Results also show that total pressure loss due to fuel-air mixing is about the same magnitude as losses due to friction. The performance of a generic, full scale scramjet using both hydrogen and hydrocarbon fuels, over a ight Mach number range of 5-15 is then investigated. Thrust loss due to skin friction and mixing are shown to be signicant. 2010-03-16T00:00:00Z Doolan, C. J. og Boyce, Russell R. http://espace.library.uq.edu.au/view/UQ:137114 In this work acoustic monitoring was performed while machining Ti6Al4V with a variety of process parameters. The surface integrity of the components was characterized using microstructural examination and hardness and surface roughness measurements. It is shown that a simple measure of the acoustic spectrum (see figure) can be used to relate operationally induced vibration to the surface integrity of the machined part. Copyright © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 2008-05-01T00:00:00Z Palanisamy, S. og Dargusch, M. S. og McDonald, S. og St John, D. H. og Brandt, M. http://espace.library.uq.edu.au/view/UQ:290242 A new arbitrarily high order method for the solution of the model Boltzmann equation for micro-channel flows in the transitional regime is presented. The Bhattnagar-Gross-Krook approximation of the Boltzmann collision integral is implemented, with Shakhov’s modification, and the resulting system of equations solved by a discrete ordinate method. The method approximates velocity space using a truncated Hermite polynomial expansion of arbitrary order and performs the associated integration by Gauss-Hermite quadrature. This approach conserves mass, momentum and energy during relaxation of the discretised velocity space towards equilibrium. Physical space is discretised by discontinuous Legendre polynomial expansions with both the spatial representation and conservative flux calculation being of arbitrary order. Owing to the high order spatial representation of the discretised velocity space the BGKShakhov relaxation process is carried out in a ‘continuous in space’ manner. New high order boundary conditions of the inviscid slip wall and no-slip wall are implemented. A new fully diffuse reflection boundary condition, built on the high order spatial information available in the method, is also proposed. Results are presented for low speed planar Couette flow and non-linear channel flow. 2013-01-30T16:27:44Z Bond, D. M. og Wheatley, V. og Macrossan, M. N. og Goldsworthy, M. http://espace.library.uq.edu.au/view/UQ:138439 2008-05-14T00:00:00Z Easton, M. og St John, D.H. og Kaufmann, H. http://espace.library.uq.edu.au/view/UQ:188170 2009-11-27T00:00:00Z StJohn, D. H. og Cao, Peng og Qian, Ma og Easton, Mark A. http://espace.library.uq.edu.au/view/UQ:102462 Continuing Professional Development (CPD) is seen as a vital part of a professional engineer’s career, by professional engineering institutions as well as individual engineers. Factors such as ever-changing workforce requirements and rapid technological change have resulted in engineers no longer being able to rely just on the skills they learnt at university or can pick up on the job; they must undergo a structured professional development with clear objectives to develop further professional knowledge, values and skills. This paper presents a course developed for students undertaking a Master of Engineering or Master of Project Management at the University of Queensland. This course was specifically designed to help students plan their continuing professional development, while developing professional skills such as communication, ethical reasoning, critical judgement and the need for sustainable development. The course utilised a work integrated learning pedagogy applied within a formal learning environment, and followed the competency based chartered membership program of Engineers Australia, the peak professional body of engineers in Australia. The course was developed and analysed using an action learning approach. The main research question was “Can extra teaching and learning activities be developed that will simulate workplace learning?” The students continually assessed and reflected upon their current competencies, skills and abilities, and planed for the future attainment of specific competencies which they identified as important to their future careers. Various evaluation methods, including surveys before and after the course, were used to evaluate the action learning intervention. It was found that the assessment developed for the course was one of the most important factors, not only in driving student learning, as is widely accepted, but also in changing the students’ understandings and acceptance of the need for continuous professional development. The students also felt that the knowledge, values and skills they developed would be beneficial for their future careers, as they were developed within the context of their own professional development, rather than to just get through the course. © 2005, American Society for Engineering Education 2007-08-23T00:00:00Z Mann, Llewellyn og Radcliffe, David http://espace.library.uq.edu.au/view/UQ:75058 The phase equilibria and liquidus temperatures in the binary SiO2-ZnO system and in the ternary Al2O3-SiO2-ZnO system at low Al2O3 concentrations have been experimentally determined using the equilibration and quenching technique followed by electron probe X-ray microanalysis. In the SiO2-ZnO system, two binary eutectics involving the congruently melting willemite (Zn2SiO4) were found at 1448 +/- 5 degrees C and 0.52 +/- 0.01 mole fraction ZnO and at 1502 +/- 5 degrees C and 0.71 +/- 0.01 mole fraction ZnO, respectively. The two ternary eutectics involving willemite previously reported in the Al2O3SiO2-ZnO system were found to be at 1315 +/- 5 degrees C and 1425 +/- 25 T, respectively. The compositions of the eutectics are 0.07, 0.52, and 0.41 and 0.05, 0.28, and 0.67 mole fraction Al2O3, SiO2, and ZnO, respectively. The results of the present investigation are significantly different from the results of previous studies. 2007-08-15T00:00:00Z Hansson, R. og Zhao, B. J. og Hayes, P. C. og Jak, E. http://espace.library.uq.edu.au/view/UQ:182122 When a repairable item fails under warranty. the manufacturer has the option of either repairing the failed item or replacing it with a new one. In this paper, a repair-replace strategy is discussed for the manufacturer of a product sold with a two-dimensional warranty. The strategy is based on a specified region of the warranty defined in terms of age and usage with the first failure in the region rectified by replacement and all other failures being minimally repaired. An accelerated failure time (AFT) model is Used to allow for the effect of usage rate on item degradation 2009-09-03T00:00:00Z Jack, N og Iskandar, BP og Murthy, DNP http://espace.library.uq.edu.au/view/UQ:287923 2012-12-30T00:09:09Z Summerscales, John og Virk, Arnandeep og Hall, Wayne http://espace.library.uq.edu.au/view/UQ:96614 2007-08-24T00:00:00Z Mayes, T. og Gillies, A. D. S. http://espace.library.uq.edu.au/view/UQ:278109 Diode laser based absorption spectroscopy (DLAS) is widely used for gas detection in variety of applications across the energy, petrochemical and mining industries. Recent developments in near and mid infrared diode lasers have improved the sensitivity of gas measurement based on high resolution spectra of target species. The availability of near-infrared diodes that can operate at room temperature has expanded the application of spectroscopy technique in hand-held gas detection devices. DLAS in conjunction with optical fibres has also been applied for the distributed sensing and monitoring of various gases in real-time basis. This paper, after introducing methane characteristics and semiconductor diode lasers, comprehensively reviews development in spectroscopic methane sensing techniques in accordance with methane absorption lines in the near infrared spectrum. 2012-07-25T21:22:38Z Shemshad, Javad og Aminossadati, Saiied Mostafa og Kizil, Mehmet Siddik http://espace.library.uq.edu.au/view/UQ:3302 Blasting is the primary comminution process in most mining operations. This process involves the highly complex and dynamic interaction between two main components. The first is the detonating explosive and the second is the rock mass into which the explosive is loaded. The mechanical properties of the rock material (such as dynamic strength, tensile strength, dynamic modulus and fracture toughness) are important considerations in understanding the blasting process. However, it is the characteristics of the geological defects (joints, foliation planes, bedding planes) within the rock mass that ultimately determine how effectively a blast performs in terms of fragmentation, all else being equal. The defect characteristics include, but are not limited to, their orientation, spacing, and mechanical properties. During the blasting process, some of the geotechnical characteristics of the rock mass are substantially changed. From the blasting outcome point of view, the most notable and important is the change in fragment size distribution that the rock mass undergoes. The pre-blast in situ defect-bounded block size distribution is transformed into the post-blast muckpile fragment size distribution. Consequently, it is fundamental to our understanding of and ability to predict the blasting process that both the blastability of a rock mass and its transformation into the fragment size distribution can be appropriately quantified. 2006-05-02T00:00:00Z Widzyk-Capehart, E. og Lilly, P. http://espace.library.uq.edu.au/view/UQ:151482 A number of patents on tyre cooling have been reviewed with a focus on those which can be applied to earthmoving tyres for the mining industry. The mechanisms of heat transfer within the tyre carcass are introduced as well as the basic tyre structure and effects of overheating on tyre operation. The tyre cooling patents are separated into five functional groups and reviews are made based on practicality and potential for significant heat transfer. This analysis has made it evident that potential cooling effectiveness is often compromised by practicality of an invention. The patents deemed to have the most potential for cooling are those which incorporate a working fluid which undergoes a phase change to transfer heat between different regions of the wheel assembly. Finally, these inventions are also related to current research projects which aim to develop a new cooling technique and extend the working life of earthmoving tyres. 2008-06-19T00:00:00Z Netscher, Nicholas W. og Aminossadati, Saiied M. og Hooman, Kamel http://espace.library.uq.edu.au/view/UQ:79376 The influence of trace level Ni additions on the eutectic solidification mode of Sn-0.7Cu has been studied using continuous torque experiments during solidification. The solid fraction at which resistance to paddle rotation at the thermal centre of the sample occurs is related to the spatial distribution of solid during solidification. The results indicate that a transition in solidification mode occurs in the range 0-300 ppm Ni. Growth occurs antiparallel to heat flow from near the mould walls in the Ni-free alloy, while equiaxed growth from distributed centres dominates in alloys containing at least 300 ppm Ni. (c) 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. 2007-08-15T00:00:00Z Gourlay, CM og Nogita, K og McDonald, SD og Nishimura, T og Sweatman, K og Dahle, AK http://espace.library.uq.edu.au/view/UQ:135230 2008-04-14T00:00:00Z Li, S. og Valenzuela, P. og Knights, P. http://espace.library.uq.edu.au/view/UQ:222827 2010-11-29T00:00:00Z Mitchell, Shane og Warren, Michael og McKinnon, David og Upcroft, Ben http://espace.library.uq.edu.au/view/UQ:259489 2011-10-25T08:14:13Z Chen, Rongzhi og Zhi, Chunyi og Yang, Huang og Bando, Yoshio og Zhang, Zhenya og Suguir, Norio og Golberg, Dmitri http://espace.library.uq.edu.au/view/UQ:82620 We consider the problems of computing the power and exponential moments EXs and EetX of square Gaussian random matrices X=A+BWC for positive integer s and real t, where W is a standard normal random vector and A, B, C are appropriately dimensioned constant matrices. We solve the problems by a matrix product scalarization technique and interpret the solutions in system-theoretic terms. The results of the paper are applicable to Bayesian prediction in multivariate autoregressive time series and mean-reverting diffusion processes. 2007-08-15T00:00:00Z Vladimirov, I .G. og Thompson, H. B. http://espace.library.uq.edu.au/view/UQ:63147 2007-08-14T00:00:00Z Qian, Ma og St John, David og Maloney, Sally K. og Couper, Malcolm J. http://espace.library.uq.edu.au/view/UQ:75532 The as-cast three-dimensional morphologies of alpha-Al-15(Fe,Mn)(3)Si-2 and beta-Al5FeSi intermetallics were investigated by serial sectioning. Large beta-Al5FeSi intermetallics were observed to grow around pre-existing dendrite arms. The alpha-Al-15(Fe,Mn)(3)Si-2 intermetallic particle was observed to have a central polyhedral particle and an external highly convoluted three-dimensional structure. (c) 2005 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. 2007-08-15T00:00:00Z Dinnis, C. M. og Taylor, J. A. og Dahle, A. K. http://espace.library.uq.edu.au/view/UQ:10005 Fracture growth is considered as the competition between cleavage and dislocation self-organization in elastic-plastic solids. A self-consistent model is proposed to bridge the responses at relevant length scales, an elastic enclave in the immediate vicinity of crack tip, an array of disclination dipoles and macroscopic plastic deformation. The directional dependence of crack growth is studied. In the continuum limit, the flow stress is expressed by a spatial coupling in terms of a second-order gradient of the rotation strength of disclination dipoles. An estimate of the core size and the crack-tip shielding ratio is given by identification of the macroscopic plastic fields, the elastic field and the constitutive flow stress from the micromechanics consideration, on the boundary of elastic core. Strong dependence of apparent fracture toughness on the intrinsic surface energy and the ductile-to-brittle transition are examined. 2004-12-24T00:00:00Z Zhang, X. og Jeffrey, R. og Mai, Y. W. http://espace.library.uq.edu.au/view/UQ:201091 2010-03-29T00:00:00Z Javad Shemshad Shadbad og Aminossadati, Saiied M. og Kizil, Mehmet S. http://espace.library.uq.edu.au/view/UQ:58775 When repairable items sold under warranty fail, the rectification action taken by the manufacturer can be either a repair or a replacement, In this paper a new repair-replacement strategy is proposed for the manufacturer when the items are sold with a non-renewing free replacement warranty policy. The strategy involves splitting the warranty period into two intervals where only repairs are carried out, separated by a third interval with at most one replacement. 2007-08-14T00:00:00Z Jack, N og Murthy, DNP http://espace.library.uq.edu.au/view/UQ:12926 The final-year project for Mechanical & Space Engineering students at UQ often involves the design and flight testing of an experiment. This report describes the design and use of a simple data logger that should be suitable for collecting data from the students' flight experiments. The exercise here was taken as far as the construction of a prototype device that is suitable for ground-based testing, say, the static firing of a hybrid rocket motor. 2007-03-16T00:00:00Z P. A. Jacobs http://espace.library.uq.edu.au/view/UQ:201976 This paper describes a simple shared-memory parallel implementation of an octree adaptive mesh Computational Fluid Dynamics (CFD) code with an explicit time discretization scheme. The parallel performance of the code when running a realistic simulation gives a serial code fraction of no more than 13%. This should be suitable for small multicore engineering workstations where a simple code is desired and medium-sized simulations are sufficient. 2010-04-08T00:00:00Z Tang, J. http://espace.library.uq.edu.au/view/UQ:282640 By measuring the resonant frequencies of cantilever beams without and with thinfilms deposited and with the use of the Euler–Bernoulli beam theory, elasticmodulus and density of thinfilms can be determined simultaneously. This simpleresonantmethod was validated using a sputtered Ni film/Si substrate system. The elasticmodulus of the Ni film obtained from this method was in excellent agreement with that measured by use of nanoindentation. 2012-10-01T19:54:26Z Ma, Shujun og Huang, Han og Lu, Mingyuan og Veidt, Martin http://espace.library.uq.edu.au/view/UQ:211775 2010-08-16T10:41:21Z Rowan Gollan og Carolyn Jacobs og Jacobs, Peter A. og Morgan, Richard G. og McIntyre, Timothy J. og Macrossan, Michael N. og Buttsworth, David R. og Eichmann, Troy N. og Daniel Potter http://espace.library.uq.edu.au/view/UQ:58768 A small disturbance in the axisymmetric, bathtub-like flow with strong vorticity is considered and the asymptotic representation of the solution is found. It is shown that if the disturbance is smaller than a certain critical scale, the conventional strong vortex approximation cannot describe the field generated by the disturbance not only in the vicinity of the disturbance but also at the distances much larger than the critical scale. (C) 2001 American Institute of Physics. 2007-08-14T00:00:00Z Klimenko, AY http://espace.library.uq.edu.au/view/UQ:7901 Traditional methods of project delivery are being challenged by Design and Construct (D&C) and alliance contracting (similar to Partnering in the USA or PFI in the UK) . In D&C projects, the design management function often rests with the prime contractor or with an alliance partnership, rather than with the specialist designers or consultants. As a consequence, construction companies, which traditionally were not directly concerned with design management, are now taking a proactive role in the design management function, within a total project management process. This paper discusses these issues through a case study of one engineering company's experiences with integrating design and construction. 2006-09-14T00:00:00Z Andersen, Janthea og Jolly, Lesley og Nycyk, Michael og Radcliffe, David http://espace.library.uq.edu.au/view/UQ:217627 A microsegregation solidification model has been extended for an individual droplet falling through a stagnant gas during the atomization process. Assuming a uniform temperature within the droplet, the model takes into account nucleation undercooling and equiaxed growth of the dendritic and eutectic microstruc-tures until complete solidification.1 It predicts the temperature evolution and the chemical segregation within the droplet in terms of the percent of the dendritic and eutectic microstructures. Extensive experiments have been performed on Al-Cu droplets using the impulse atomization technique. The distribution of phases, cell spacing and segregation have been quantified earlier.2-4 It has been reported that the amount of eutectic in the droplets falls below the equilibrium prediction as the alloy composition increases. Successful comparison between the model results and the experiments leads to the conclusion that eutectic undercooling and eutectic recalescence play a very important role in the final percent of eutectic in the droplets. © 2009 ISIJ. 2010-10-01T00:00:00Z Prasad, Arvind og Mosbah, Salem og Henein, Hani og Gandin, Charles-André