Engineering Commons^™

Effect Of High Pressure During The Fabrication On The Thermal And Mechanical Properties Of Amorphous Ni60nb40 Particle-Reinforced Al-Based Metal Matrix Composites, Peng Yu, Shankar Venkataraman, Jayanta Das, Laichang Zhang, Wenyong Zhang, Jurgen Eckert

Faculty of Engineering - Papers (Archive)

Ni₆₀Nb₄₀ metallic glass particles, prepared by mechanical alloying, were used to fabricate Al–30 wt% Ni₆₀Nb₄₀ metal matrix composites (MMCs) at 823 K by sintering, hot pressing, and hot extrusion. The Ni₆₀Nb₄₀ reinforcements remained amorphous in all the MMCs fabricated by the different methods. Compression tests revealed that the Young’s modulus and yield strength of the MMCs produced by hot-pressing and hot-extrusion are higher than those for the sintered specimens. Differential scanning calorimeter (DSC) annealing of the as-produced MMCs at 913 K revealed there are severe interfacial reactions between the Al matrix …

Magnetovolume Effect And Magnetic Properties Of Dy2fe17-Xmnx, Jianli Wang, Stewart J. Campbell, O Tegus, C Marquina, M R. Ibarra

Faculty of Engineering - Papers (Archive)

The structural and magnetic properties of Dy₂Fe_17−xMn_x (x=0–5) compounds have been investigated using x-ray diffraction, linear thermal expansion, magnetization measurements, and ⁵⁷Fe Mössbauer spectroscopy. Compared with Dy₂Co_17−xMn_x compounds for which a linear increase of the unit-cell volume V with increasing Mn fraction is found, the compositional dependence of the lattice parameters of Dy₂Fe_17−xMn_x first exhibits a slight maximum around x=0.5 before increasing monotonically with further increase in x; this behavior can be ascribed to a spontaneous magnetostriction as confirmed by linear-thermal-expansion measurements. The Curie …

Spin-Orbit Interaction Enhanced Polaron Effect In Two-Dimensional Semiconductors, Zhou Li, Zhongshui Ma, Anthony Wright, Chao Zhang

Faculty of Engineering - Papers (Archive)

It is shown that in two-dimensional semiconductors, the electron-phonon interaction and polaronmass correction are both significantly enhanced by the Rashba spin-orbit coupling. The masscorrection is positive for the upper Rashba branch and negative for the lower Rashba branch. BothRashba branches have the same polaron binding energy, which is higher than that for systems in theabsence of spin-orbit interaction. To the leading order, the correction to the binding energy isproportional to the square of the spin-orbit coupling strength.

Effect Of Boron Powder Purity On Superconducting Properties Of Mgb2, Xun Xu, Meng J. Qin, Konstantin K. Konstantinov, Dayse Dos Santos, Wai Kong Yeoh, Jung Ho Kim, S. X. Dou

Faculty of Engineering - Papers (Archive)

The effect of the properties of starting boron powders on the superconducting properties of MgB₂ has been studied. The 92% and 96% pure powders produce lower surface reactivity and larger particle size than the 99% boron powder, as can be seen from Brunauer–Emmett–Teller (BET) and scanning electron microscopy (SEM) results, indicating that the low purity powders cannot be used to archive the same superconducting properties as those of samples made from pure 99% boron powder. However, the purity of 92% and 96% boron powders can be improved by using a simple chemical process, leading to enhanced magnetic critical current …

Effect Of Particle Composition On Consolidation Of Hot Briquetted Iron, Wanda Melfo, Rian J. Dippenaar, Brian J. Monaghan

Faculty of Engineering - Papers (Archive)

The influence of the carbon concentration of directly reduced iron (DRI) powders on the compressibility and fracture strength of hot briquetted iron (HBI) has been studied. Industrially produced DRI, pure iron powder and Fe–C alloy powders (synthetic DRI) were used in the study. It was found that the mechanism of compaction could be attributed to pure yielding. The pressure required to attain a given density increased proportionally with the carbon content. The morphology and phases present in DRI powder had a significant influence on the compressibility. The fracture strength of the compacts increased with increasing carbon content of the DRI …

Effect Of Changing Slag Composition On Spinel Inclusion Dissolution, Brian J. Monaghan, Liang Chen

Faculty of Engineering - Papers (Archive)

The rate of MgAl2O4 spinel inclusion dissolution in CaO–SiO2–Al2O3 slags at 1504uC has been measured using a laser scanning confocal microscope. It was found that the mechanism of spinel inclusion dissolution was at least in part controlled by mass transfer in the slag phase for the slag compositions used. Evidence in support of this finding was that the calculated diffusion coefficient was inversely proportional to the slag viscosity and that the diffusion coefficients were in reasonable agreement with those obtained in a separate study on alumina dissolution. The diffusion coefficients obtained were in the range of 0.76–2.2610210 m2 s21.

The Effect Of Small Business Clusters In Prioritising Barriers To E-Commerce Adoption In Regional Smes, Robert Macgregor, Lejla Vrazalic

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a study of Swedish regional small businesses which investigated the barriers to E-commerce adoption (amongst other things). The aim of the paper is twofold: to examine the correlation between barriers to E-commerce adoption in order to identify underlying factors: and to determine whether these differ between SMEs that are members of a small business cluster and SMEs that are not. The paper begins by examining the nature of SMEs and identifying features that are unique to SMEs. A discussion of barriers to E-commerce adoption based on previous research is then presented and the barriers are mapped to …

The Effect Of Oxidation On The Structure Of Styryl-Substituted Sexithiophenes: A Resonance Raman Spectroscopy And Density Functional Theory Study, Tracy Clarke, Keith Gordon, David L. Officer, Daina K. Grant

Australian Institute for Innovative Materials - Papers

The structures and vibrational properties of a series of styryl-substituted sexithiophenes and their charged species have been examined using resonance Raman spectroscopy in conjunction with density functional theory calculations. The calculated geometries of the radical cations and dications indicate that the quinoidal charged defects are more strongly localized in the center of the thiophene backbone than is observed in other sexithiophenes. This defect confinement, induced by the positions of the styryl substituents, is particularly evident in the dication species. However, the defect confinement weakens when alkoxy groups are added onto the phenyl rings by causing the extension of the charged …

Magneto-Radiotherapy: Effect Of Magnetic Field On Dose Distribution And Rbe, Heidi Nettelbeck, Anatoly B. Rosenfeld, George J. Takacs, Michael L. Lerch

Faculty of Engineering - Papers (Archive)

Magneto-radiotherapy is the application of magnetic fields during radiotherapy procedures. It aims to improve the quality of cancer treatment by altering the dose deposition of charged particles in the tissue volume being targeted. Our research has focused on applying the concept of magneto-radiotherapy to conventional linac treatment and MRT (Microbeam Radiation Therapy) oncology modalities.

Modeling The Effect Of P53 On Tumor Heterogeneity And The Mutator Phenotype, Melissa Ryan, Matthew J. Berryman, Derek Abbott

Faculty of Engineering - Papers (Archive)

p53 is an important gene, involved in apoptosis (programmed cell death), DNA repair, and cell cycle progression. We explore the selective advantages and disadvantages of mutations in the p53 gene on tumor cells, and the heterogeneity of tumor cell populations. Based on an evolutionary computational approach, our model considers changes in mutation rate caused by lack of DNA repair processes, and the lack of apoptosis caused by mutations in p53. We find that the degree of robustness of p53 to mutations has a significant effect on the tumor heterogeneity and “fitness”, with clinical consequences for people who inherit p53 mutations.

Dynamic Modeling And Simulation Of A Multi Effect Humidification-Dehumidification Desalination Unit, Mohammed I. Sohel, B Dawoud

Faculty of Engineering and Information Sciences - Papers: Part A

Recently solar distillation using Multi Effect Humidification-dehumidification (MEH) cycle is receiving special attention. In this communication detailed models of MEH are presented that take into account most of the dynamic behavior with reasonable accuracy. Using these models simulation was carried out and the results of simulation were discussed in this paper. To find out the competence of the newly developed models, some of the simulation results were compared with the available experimental data in the literature. It turned out that the result of simulation give a very good agreement with the experimental data. The maximum deviation between simulation and experimental …

The Effect Of Resin Thickness On Bolt-Grout-Concrete Interaction In Shear, Najdat I. Aziz, Jalalifar Hossein, Muhammad N. S Hadi

Faculty of Engineering - Papers (Archive)

Numerical modelling is extensively used in civil and mining engineering applications because of cost and risk problems associated with different experimental studies. In this study, the effect of resin thickness was evaluated in bolt-grout-concrete interaction and bending behaviour of a fully grouted bolt installed across joints in post failure region. Tests were conducted in 20 and 40 MPa concretes, and modelling simulations were made, using ANSYS version 8.1, to include both with and without different pretension loads. It was found that in all resin thickness, both the strength of the concrete and bolt pretension had major influences on the shear …

Effect Of Doping On Flux Pinning Of Gdba2cu3o7-Y, L Zhang, X B Xu, S Y Ding, M H Zheng, L Xiao, H T Ren, Y L Jiao, Xiaolin Wang, Zhi W. Lin, Jian G. Zhu

Australian Institute for Innovative Materials - Papers

Cylindrical single grains of GdBa 2Cu3Oy sGd-123d with a diameter of 25 mm were successfully fabricated by melt-texture growth sMTGd process in air to study the influence of different starting powders on flux pinning. Measurements of the magnetic critical current density sJcd showed that it was possible to fabricate large Gd-123 single grain with a high Jc at high temperatures and fields by means of properly controlling the starting powders of Gd 2O3, BaCO3 , and CuO before the process.

Effect Of Helical Pitch And Tensile Reinforcement Ratio On The Concrete Cover Spalling Off Load And Ductility Of Hsc Beams, Nuri M. Elbasha, Muhammad N. S Hadi

Faculty of Engineering - Papers (Archive)

[extract] In recent years a marked increase in the use of High Strength Concrete (HSC) has been evident in Australian building construction despite the fact that the current Australian design standard, AS3600 provides no design rules. HSC has been used extensively in civil construction projects world wide because it reduces the cross section and the weight for long construction members.

High strength concrete and high strength steel are used together to increase the load capacity and reduce the beams' cross section. Using these two materials to design over reinforced beams will lead to huge reduction of cost, which is a …

Finite-Element Analysis To Determine Effect Of Monolimb Flexibility On Structural Strength And Interaction Between Residual Limb And Prosthetic Socket, Winson Lee, Ming Zhang, David A. Boone, Bill Contoyannis

Faculty of Engineering and Information Sciences - Papers: Part A

Monolimb refers to a kind of transtibial prostheses having the socket and shank molded into one piece of thermoplastic material. One of its characteristics is that the shank is made of a material that can deform during walking, which can simulate ankle joint motion to some extent. Changes in shank geometry can alter the stress distribution within the monolimb and at the residual limb-socket interface and, respectively, affect the deformability and structural integrity of the prosthesis and comfort perceived by amputees. This paper describes the development of a finite-element model for the study of the structural behavior of monolimbs with …

Study On The Mechanism Of The Squeeze-Strengthen Effect In Magnetorheological Fluids, Xianzhou Zhang, X L. Gong, P Q. Zhang, Q M. Wang

Faculty of Engineering and Information Sciences - Papers: Part A

Current magnetorheological (MR)fluids have the limitation that their yield stresses are not strong enough to meet some industrial requirements. X. Tang, X. Zhang, and R. Tao [J. App. Phys87, 2634 (2000)] proposed a method to achieve high-efficiency MR fluids by study of squeeze-strengthen effect. But there is little report on its mechanism. This paper aims to investigate this effect through experimental and theoretical approaches. For this purpose, an apparatus is designed to experimentally study the mechanism of this squeeze-strengthen effect. Taking account of a modified magnetic dipole model and the friction effect, a semiempirical model is proposed to explain this …

Effect Of Aging And Deformation On The Microstructure And Properties Of Fe-Ni-Ti Maraging Steel, A Shekhter, H I. Aaronson, M K. Miller, S P. Ringer, E V. Pereloma

Faculty of Engineering and Information Sciences - Papers: Part A

The age-hardening behavior of Fe−25.3Ni−1.7 Ti (wt pct) alloy both in undeformed specimens and in specimens cold deformed by 10 or 20 pct prior to aging was studied. The microstructural changes during aging were observed using transmission electron microscopy (TEM) and atom probe analysis and there were related to the mechanical properties as measured by microhardness and shear punch testing. An excellent combination of hardness, strength, and ductility was achieved after only 5 seconds aging at 550°C. We propose that this rapid strengthening is due to a dislocation friction effect arising from the formation of a fine dispersion of Ni−Ti …

Effect Of Microstructure On The Stability Of Retained Austenite In Transformation-Induced-Plasiticity Steels, I B. Timokhina, P D. Hodgson, E V. Pereloma

Faculty of Engineering and Information Sciences - Papers: Part A

Two Fe-0.2C-1.55Mn-1.5Si (in wt pct) steels, with and without the addition of 0.039Nb (in wt pct), were studied using laboratory rolling-mill simulations of controlled thermomechanical processing. The microstructures of all samples were characterized by optical metallography, X-ray diffraction (XRD), and transmission electron microscopy (TEM). The microstructural behavior of phases under applied strain was studied using a heat-tinting technique. Despite the similarity in the microstructures of the two steels (equal amounts of polygonal ferrite, carbide-free bainite, and retained austenite), the mechanical properties were different. The mechanical properties of these transformation-induced-plasticity (TRIP) steels depended not only on the individual behavior of all …

Synchrotron Radiation Based Experimental Determination Of The Optimal Energy For Cell Radiotoxicity Enhancement Following Photoelectric Effect On Stable Iodinated Compounds, S Corde, A Joubert, J F. Adam, A M. Charvet, J F. Le Bas, F Esteve, H Elleaume, J Balosso

Faculty of Engineering and Information Sciences - Papers: Part A

This study was designed to experimentally evaluate the optimal X-ray energy for increasing the radiation energy absorbed in tumours loaded with iodinated compounds, using the photoelectric effect. SQ20B human cells were irradiated with synchrotron monochromatic beam tuned at 32.8, 33.5, 50 and 70 keV. Two cell treatments were compared to the control: cells suspended in 10 mg ml1 of iodine radiological contrast agent or cells pre-exposed with 10 mM of iodo-desoxyuridine (IUdR) for 48 h. Our radiobiological end point was clonogenic cell survival. Cells irradiated with both iodine compounds exhibited a radiation sensitisation enhancement. Moreover, it was energy dependent, with …

The Effect Of An Applied Electrical Potential On Refractory Corrosion By Slag, Brian J. Monaghan, Sharon Nightingale, Q Dong

Faculty of Engineering - Papers (Archive)

An investigation has been carried out to assess the effects of an applied voltage on the dissolution rate of MgO refractory in a steelmaking like slag. In this study corrosion results obtained from dip tests using a dense direct bonded MgO refractory in a CaO-SiO2-Fe2O3-FeO-MgO slag are presented. These results demonstrate that the application of a voltage across a dense MgO refractory-slag interface can change the rate of refractory dissolution. For the slag composition used and the voltage range tested, it was found that a maximum corrosion rate was obtained at a voltage setting of –0.45V. The results of this …

Effect Of Deformation Schedule On The Microstructure And Mechanical Properties Of A Thermomechanically Processed C-Mn-Si Transformation-Induced Plasticity Steel, I B. Timokhina, P D. Hodgson, E V. Pereloma

Faculty of Engineering and Information Sciences - Papers: Part A

Thermomechanical processing simulations were performed using a hot-torsion machine, in order to develop a comprehensive understanding of the effect of severe deformation in the recrystallized and nonrecrystallized austenite regions on the microstructural evolution and mechanical properties of the 0.2 wt pct C-1.55 wt pct Mn-1.5 wt pct Si transformation-induced plasticity (TRIP) steel. The deformation schedule affected all constituents (polygonal ferrite, bainite in different morphologies, retained austenite, and martensite) of the multiphased TRIP steel microstructure. The complex relationships between the volume fraction of the retained austenite, the morphology and distribution of all phases present in the microstructure, and the mechanical properties …

The Effect Of Foamy Slag In Electric Arc Furnaces On Electric Energy Consumption, Sima Aminorroaya-Yamini, Hossein Edris

Australian Institute for Innovative Materials - Papers

In electric arc furnace steelmaking units, the essential parameters that considered important are reducing price, increasing production and decreasing environmental pollution. Electric arc furnaces are the largest users of electric energy in industry. The most important techniques that can be used to reduce the electric energy consumption in electric arc furnaces are scrap preheating, stirring, use of burners and hot charge and foamy slag.

Between these methods, use of foamy slag is the most useful and economic factor. Foamy slag can reduce the amount of energy, electrods, refractory consumption, tap to tap time and increases productivity. In this research, method …

The Effect Of Different Rotation Patterns On The Revisions Of Trend Estimates, David G. Steel, Craig H. Mclaren

Faculty of Engineering and Information Sciences - Papers: Part A

The X11 and X11ARIMA procedures are widely used to produce seasonally adjusted and trend estimates from time series obtained from sample surveys. The surveys are often based on designs in which there is sample overlap between different periods. The degree of overlap is determined by the pattern of inclusion of selected units over time, i.e., the rotation pattern. An important issue in analysing the series is that trend estimates at the end of the series are revised as estimates for recent periods are added. This article considers the effects of different rotation patterns on the mean squared error of the …

Effect Of A Robot's Geometrical Parameters On Its Optimal Dynamic Performance, M. Yousef Ibrahim, Christopher D. Cook, A K. Tieu

Faculty of Engineering - Papers (Archive)

This paper presents a study that was conducted at Monash University College - Gippsland on the effect of a robot’s geometrical parameters on its dynamic performance. This research was undertaken in pursuit of an optimal dynamic performance of industrial robots. In this study an indicator was established to quantitatively measure the dynamic performance of a robot arm with respect to changes in the geometrical parameters. Since the dynamic behaviour of a robot’s arm is largely dependent on its inertia terms; the performance indicator was based on the Logarithmic function of the sensitivity of the inertia matrix’s eigenvalues to changes in …

Effect Of Postinfection Application Of Phosphorous (Phosphonic) Acid On The Incidence And Sporulation Of Plasmopara Viticola On Grapevine, T J. Wicks, P A. Magarey, M F. Wachtel, A B. Frensham

Faculty of Engineering and Information Sciences - Papers: Part A

Phosphorous acid (H3P03) applied at 1.2 gIL up to 12 days after infection reduced the incidence and severity of Plasmopara vitieola. When applied up to 13 days after infection, H3P03 reduced sporulation. In some experiments, the postinfection activity of H3P03 was better than metalaxyl, while in other experiments it was less effective. Both fungicides applied after infection reduced the incidence and severity of disease on leaves and flower clusters, indicating that postinfection applications should reduce the production of inoculum and the consequent spread of disease within a vineyard. In most cases, the addition of copper oxychloride did not affect the …

Simulation Of The Effect Of Wind On Rectangular Sedimentation Tanks, Muttucumaru Sivakumar, S A. Lowe

Faculty of Engineering - Papers (Archive)

A numerical model is presented to simulate the effect of wind action on rectangular sedimentation tanks used in water and wastewater treatment plants. The mathematical model uses the k-r. model for fl uid flow and sediment transport, and is solved using an explicit finite diffence scheme incorporating a penalty function approach. Simulations of fluid flow velocity and aeqiment concentration are presented for two wind speeds in two directions. It is shown that the effect of wind action is significant and future design of sedimentation tanks should include this parameter.