ORCID Profile
0000-0002-7892-4620
Current Organisation
University of South Australia
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Applied Mathematics | Biological Mathematics | Dynamical Systems in Applications | Mineral Processing/Beneficiation | Partial Differential Equations | Control Systems, Robotics and Automation | Applied Mathematics not elsewhere classified | Electrical and Electronic Engineering | Materials Engineering not elsewhere classified | Decision Support and Group Support Systems |
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in the Mathematical Sciences | Energy Conservation and Efficiency not elsewhere classified | Expanding Knowledge in the Physical Sciences | Beneficiation or Dressing of Iron Ores | Mining and Extraction of Precious (Noble) Metal Ores | Expanding Knowledge in the Biological Sciences | Mining and Extraction of Copper Ores
Related Links
Publications
Dynamic Dielectric Response of Concentrated Colloidal Dispersions: Comparison between Theory and Experiment
Publisher: American Chemical Society (ACS)
Date: 20-01-2009
DOI: 10.1021/LA8028963
Abstract: The cell-model electrokinetic theory of Ahualli et al. Langmuir 2006, 22, 7041 Ahualli et al. J. Colloid Interface Sci. 2007, 309, 342 and Bradshaw-Hajek et al. Langmuir 2008, 24, 4512 is applied to a dense suspension of charged spherical particles, to exhibit the system's dielectric response to an applied electric field as a function of solids volume fraction. The model's predictions of effective permittivity and complex conductivity are favorably compared with published theoretical calculations and experimental measurements on dense colloidal systems. Physical factors governing the volume fraction dependence of the dielectric response are discussed.
Nonlinear fluid flow and heat transfer
Publisher: Hindawi Limited
Date: 2014
DOI: 10.1155/2014/719102
Controlling Bubble–Solid Surface Interactions with Environmentally Benign Interfacial Modifiers
Publisher: American Chemical Society (ACS)
Date: 10-01-2019
High-Frequency Behavior of the Dynamic Mobility and Dielectric Response of Concentrated Colloidal Dispersions
Publisher: American Chemical Society (ACS)
Date: 17-09-2009
DOI: 10.1021/LA9026255
Abstract: A matched asymptotic analysis of the system of equations governing the electrokinetic cell model of ref 4 (Ahualli, S. Delgado, A. Miklavcic, S. White, L. R. Langmuir 2006, 22, 7041) is performed. Asymptotic expressions are obtained for the dynamic mobility and complex conductivity response of a dense suspension of charged spherical particles to an applied electric field. The asymptotic expressions are compared with full numerical calculations of the linear response functions as a function of surface (zeta) potential, electrolyte strength, and particle density. We find that the numerical procedure used is robust and highly accurate at a very high frequency under a wide range of double-layer conditions. The asymptotic form for the dielectric response of the system is accurate to megahertz frequencies. The asymptotic formulas for the other response functions have limited viability as predictive tools within the current range of experimentally accessible frequencies but are useful as checks on numerical calculations.
Exact solutions for logistic reaction-diffusion equations in biology
Publisher: Springer Science and Business Media LLC
Date: 16-07-2016
Analytic solutions for calcium ion fertilisation waves on the surface of eggs
Publisher: Oxford University Press (OUP)
Date: 15-02-2019
Abstract: The evolution of calcium fertilisation waves on the cortex of hibian eggs can be described by a nonlinear reaction-diffusion process on the surface of a sphere. Here, we use the nonclassical symmetry technique to find an exact analytic solution that describes the evolution of the calcium concentration. The solutions presented compare well with published experimental results. The analytic solution can be used to give insight into the processes governing the fertilisation wave, such as the flow of calcium ions from the sperm entry point. By finding a spiral solution to an approximate equation linearised near saturation, we also demonstrate how solutions with other properties may be constructed using this technique.
The evolution of a viscous thread pulled with a prescribed speed
Publisher: Cambridge University Press (CUP)
Date: 14-04-2016
DOI: 10.1017/JFM.2016.215
Abstract: We examine the extension of an axisymmetric viscous thread that is pulled at both ends with a prescribed speed such that the effects of inertia are initially small. After neglecting surface tension, we derive a particularly convenient form of the long-wavelength equations that describe long and thin threads. Two generic classes of initial thread shape are considered as well as the special case of a circular cylinder. In these cases, we determine explicit asymptotic solutions while the effects of inertia remain small. We further show that inertia will ultimately become important only if the long-time asymptotic form of the pulling speed is faster than a power law with a critical exponent. The critical exponent can take two possible values depending on whether or not the initial minimum of the thread radius is located at the pulled end. In addition, we obtain asymptotic expressions for the solution at large times in the case in which the critical exponent is exceeded and hence inertia becomes important. Despite the apparent simplicity of the problem, the solutions exhibit a surprisingly rich structure. In particular, in the case in which the initial minimum is not at the pulled end, we show that there are two very different types of solution that exhibit very different extension mechanics. Both the small-inertia solutions and the large-time asymptotic expressions compare well with numerical solutions.
The onset of recirculation flow in periodic capillaries: Geometric effects
Publisher: Elsevier BV
Date: 09-2015
Interfacial Tension Sensor for Low Dosage Surfactant Detection
Publisher: MDPI AG
Date: 03-02-2021
Abstract: Currently there are no available methods for in-line measurement of gas-liquid interfacial tension during the flotation process. Microfluidic devices have the potential to be deployed in such settings to allow for a rapid in-line determination of the interfacial tension, and hence provide information on frother concentration. This paper presents the development of a simple method for interfacial tension determination based on a microfluidic device with a flow-focusing geometry. The bubble generation frequency in such a microfluidic device is correlated with the concentration of two flotation frothers (characterized by very different adsorption kinetic behavior). The results are compared with the equilibrium interfacial tension values determined using classical profile analysis tensiometry.
Interfacial characterisation for flotation: 1. Solid-liquid interface
Publisher: Elsevier BV
Date: 09-2018
Extensional flow at low Reynolds number with surface tension
Publisher: Springer Science and Business Media LLC
Date: 08-12-2011
Interaction of ferric ions with europium metal organic framework and application to mineral processing sensing
Publisher: Informa UK Limited
Date: 22-04-2022
Nonclassical symmetry solutions for reaction-diffusion equations with explicit spatial dependence
Publisher: Elsevier BV
Date: 11-2007
Mechanical properties of thin films at the dodecane-water interface, for multilayered emulsion applications
Publisher: Elsevier BV
Date: 10-2021
Polyelectrolyte multilayer formation on protein layer supports
Publisher: Elsevier BV
Date: 11-2021
An analysis of organic carbon removal in a two‐reactor cascade with recycle and a two‐reactor step‐feed cascade with recycle
Publisher: Wiley
Date: 02-12-2020
DOI: 10.1002/APJ.2392
A robust cubic reaction-diffusion system for gene propagation
Publisher: Elsevier BV
Date: 05-2004
Bounds for systems of coupled advection-diffusion equations with application to the Poisson-Nernst-Plank equations
Publisher: American Physical Society (APS)
Date: 18-10-2022
van der Waals interaction energies for ferric ion sensors using prismatic and cylindrical pore approximations for a MOF pore
Publisher: The Royal Society
Date: 05-2023
DOI: 10.1098/RSOS.230232
Abstract: Using the Lennard–Jones potential, we determine analytical expressions for van der Waals interaction energies between a point and a rectangular prism-shaped pore, writing them in terms of standard elementary functions. The parameter values for a new ferric ion sensor are used to compare these calculations with the cylindrical pore approximation for the interactions between an ion and a metal organic framework (MOF) pore. The results using the prismatic pore approximation predict the same qualitative outcomes as a cylindrical pore approximation. However, the prismatic approximation predicts lower magnitudes for both the interaction potential energy minimum and the force maximum, since the average distance from the centre-line to the surface of the prism is greater. We suggest that in some circumstances it is sufficient to use the simpler cylindrical approximation, provided that the cylinder radius is chosen so that the cross-sectional area is equal to the area of the prism pore opening. However, atoms at the nodes should remain approximated by semi-infinite lines. We also determine the interaction between a second ferric ion and a blocked MOF pore as expected, the second ferric ion experiences a force away from the pore, implying that approaching ferric ions can only occupy vacant MOF pores.
Fast vapor detection by a micropillar array-integrated colorimetric sensor
Publisher: IEEE
Date: 30-10-2022
Conditionally integrable PDEs, non-classical symmetries and applications
Publisher: The Royal Society
Date: 08-2023
Abstract: Some multi-dimensional nonlinear partial differential equations reduce to a linear equation in fewer dimensions after imposing one additional constraint. A large class of useful conditionally integrable reaction–diffusion equations follows from a single non-classical symmetry reduction, yielding an infinite-dimensional but incomplete solution space. This solution device extends further to other nonlinear equations such as higher-order reaction–diffusion, fractional-order diffusion and diffusion–convection. Applications are shown for population dynamics with or without weak Allee effects, speed-limited hyperbolic diffusion, material phase field dynamics, soil–water–plant dynamics and calcium transport on the curved surface of an oocyte. Beyond non-classical symmetry analysis, ex les of other conditionally integrable equations are given nonlinear diffusion in 1 + 2 dimensions and the Madelung–Burgers quantum fluid in 1 + 3 dimensions.
Investigating undergraduate mathematics learners’ cognitive engagement with recorded lecture videos
Publisher: Informa UK Limited
Date: 12-04-2018
Front and pulse solutions for a system of reaction-diffusion equations with degenerate source terms
Publisher: American Physical Society (APS)
Date: 21-02-2019
Ferric Ion Diffusion for MOF-Polymer Composite with Internal Boundary Sinks
Publisher: MDPI AG
Date: 07-03-2022
DOI: 10.3390/NANO12050887
Abstract: Simple and economical ferric ion detection is necessary in many industries. An europium-based metal organic framework has selective sensing properties for solutions containing ferric ions and shows promise as a key component in a new sensor. We study an idealised sensor that consists of metal organic framework (MOF) crystals placed on a polymer surface. A two-dimensional diffusion model is used to predict the movement of ferric ions through the solution and polymer, and the ferric ion association to a MOF crystal at the boundary between the different media. A simplified one-dimensional model identifies the choice of appropriate values for the dimensionless parameters required to optimise the time for a MOF crystal to reach steady state. The model predicts that a large non-dimensional diffusion coefficient and an effective association with a small effective flux will reduce the time to steady-state. The effective dissociation is the most significant parameter to aid the estimation of the ferric ion concentration. This paper provides some theoretical insight for material scientists to optimise the design of a new ferric ion sensor.
The extended-domain-eigenfunction method for solving elliptic boundary value problems with annular domains
Publisher: IOP Publishing
Date: 15-04-2010
The Actual Dielectric Response Function for a Colloidal Suspension of Spherical Particles
Publisher: American Chemical Society (ACS)
Date: 15-04-2010
DOI: 10.1021/LA904767P
Abstract: In this paper, we present a theoretical analysis of the dielectric response of a dense suspension of spherical colloidal particles based on a self-consistent cell model. Particular attention is paid to (a) the relationship between the dielectric response and the conductivity response and (b) the connection between the real and imaginary parts of these responses based on the Kramers-Kronig relations. We have thus clarified the analysis of Carrique et al. (Carrique, F. Criado, C. Delgado, A. V. J. Colloid Interface Sci. 1993, 156, 117). We have shown that both the conduction and displacement current components are complex quantities with both real and imaginary parts being frequency dependent. The dielectric response exhibits characteristics of two relaxation phenomena: the Maxwell-Wagner and the alpha-relaxations, with the imaginary part being the more sensitive instrument. The inverse Fourier transform of the simulated dielectric response is compared with a phenomenological, two-exponential response function with good agreement obtained. The two fitted decay times also compare well with times extracted from the explicit simulations.
Computation of extensional fall of slender viscous drops by a one-dimensional eulerian method
Publisher: Society for Industrial & Applied Mathematics (SIAM)
Date: 2007
DOI: 10.1137/050646743
Evolving gene frequencies in a population with three possible alleles at a locus
Publisher: Elsevier BV
Date: 2008
Convective and diffusive effects on particle transport in asymmetric periodic capillaries
Publisher: Public Library of Science (PLoS)
Date: 25-08-2017
Symmetry solutions for reaction-diffusion equations with spatially dependent diffusivity
Publisher: Elsevier BV
Date: 03-2015
A composite Level Set and Extended-Domain-Eigenfunction Method for simulating 2D Stokes flow involving a free surface
Publisher: Elsevier BV
Date: 2013
Reversible colorimetric sensing of volatile analytes by wicking in close proximity to a photonic film
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2RA06740D
Abstract: Isolation of volatile analytes from fluid s les is a rate-determining step that can delay sensor response time. An optofluidic sensing platform capable of rapidly detecting gas-phase analytes from flowing micro-volume fluid s les is reported.
Microvolume Screening of Extraction and Phase Behavior in a Liquid–Liquid Microsystem
Publisher: American Chemical Society (ACS)
Date: 30-04-2020
Exact time-dependent solutions of a Fisher–KPP-like equation obtained with nonclassical symmetry analysis
Publisher: Elsevier BV
Date: 10-2022
Nonclassical Symmetry Solutions for Non-Autonomous Reaction-Diffusion Equations
Publisher: MDPI AG
Date: 12-02-2019
DOI: 10.3390/SYM11020208
Abstract: The behaviour of many systems in chemistry, combustion and biology can be described using nonlinear reaction diffusion equations. Here, we use nonclassical symmetry techniques to analyse a class of nonlinear reaction diffusion equations, where both the diffusion coefficient and the coefficient of the reaction term are spatially dependent. We construct new exact group invariant solutions for several forms of the spatial dependence, and the relevance of some of the solutions to population dynamics modelling is discussed.
Can small air bubbles probe very low frother concentration faster?
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1SM01318A
Abstract: The differences in the degree of tangential immobilisation of small bubbles caused by two different frothers are discussed in the context of differences in the structure of the dynamic adsorption layer, which is formed during the bubble rise.
Mobile or Immobile? Rise Velocity of Air Bubbles in High-Purity Water
Publisher: American Chemical Society (ACS)
Date: 23-05-2019
Exact non-classical symmetry solutions of Arrhenius reaction–diffusion
Publisher: The Royal Society
Date: 12-2015
Abstract: Exact solutions for nonlinear Arrhenius reaction–diffusion are constructed in n -dimensions. A single relationship between nonlinear diffusivity and the nonlinear reaction term leads to a non-classical Lie symmetry whose invariant solutions have a heat flux that is exponential in time (either growth or decay), and satisfying a linear Helmholtz equation in space. This construction also extends to heterogeneous diffusion wherein the nonlinear diffusivity factorizes to the product of a function of temperature and a function of position. Ex le solutions are given with applications to heat conduction in conjunction with either exothermic or endothermic reactions, and to soil–water flow in conjunction with water extraction by a web of plant roots.
Frequency-dependent electrical conductivity of concentrated dispersions of spherical colloidal particles
Publisher: American Chemical Society (ACS)
Date: 19-03-2008
DOI: 10.1021/LA703777G
Abstract: This paper outlines the application of a self-consistent cell-model theory of electrokinetics to the problem of determining the electrical conductivity of a dense suspension of spherical colloidal particles. Numerical solutions of the standard electrokinetic equations, subject to self-consistent boundary conditions, are implemented in formulas for the electrical conductivity appropriate to the particle-averaged cell model of the suspension. Results of calculations as a function of frequency, zeta potential, volume fraction, and electrolyte composition, are presented and discussed.
Symmetry analysis of a heat conduction model for heat transfer in a longitudinal rectangular fin of a heterogeneous material
Publisher: Elsevier BV
Date: 09-2013
Convective and diffusive particle transport in channels of periodic cross-section: comparison with experiment
Publisher: Springer Science and Business Media LLC
Date: 11-01-2018
Numerical implementation of the EDEM for modified Helmholtz BVPs on annular domains
Publisher: Elsevier BV
Date: 2011
Incorporation and antimicrobial activity of nisin Z within carrageenan/chitosan multilayers
Publisher: Springer Science and Business Media LLC
Date: 18-01-2021
DOI: 10.1038/S41598-020-79702-3
Abstract: An antimicrobial peptide, nisin Z, was embedded within polyelectrolyte multilayers (PEMs) composed of natural polysaccharides in order to explore the potential of forming a multilayer with antimicrobial properties. Using attenuated total reflection Fourier transform infrared spectroscopy (ATR FTIR), the formation of carrageenan/chitosan multilayers and the inclusion of nisin Z in two different configurations was investigated. Approximately 0.89 µg cm −2 nisin Z was contained within a 4.5 bilayer film. The antimicrobial properties of these films were also investigated. The peptide containing films were able to kill over 90% and 99% of planktonic and biofilm cells, respectively, against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) strains compared to control films. Additionally, surface topography and wettability studies using atomic force microscopy (AFM) and the captive bubble technique revealed that surface roughness and hydrophobicity was similar for both nisin containing multilayers. This suggests that the antimicrobial efficacy of the peptide is unaffected by its location within the multilayer. Overall, these results demonstrate the potential to embed and protect natural antimicrobials within a multilayer to create functionalised coatings that may be desired by industry, such as in the food, biomaterials, and pharmaceutical industry sectors.
Related Organisations
Related Funding Activities
Discovery Projects - Grant ID: DP200102130
Start Date: 03-2020
End Date: 08-2024
Amount: $480,000.00
Funder: Australian Research Council
View Funded ActivityIndustrial Transformation Training Centres - Grant ID: IC190100017
Start Date: 08-2020
End Date: 08-2026
Amount: $3,703,664.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP210102246
Start Date: 2022
End Date: 12-2024
Amount: $225,000.00
Funder: Australian Research Council
View Funded Activity