Prof. Stephen O'Brien

Faculty Of Science & Engineering

Dept. Of Mathematics & Statistics

Email: stephen.obrien@ul.ie

Biography

My interests lie in mathematical modelling of physical and industrial processes generally using asymptotic and numerical techniques. The emphasis is placed on trying to understand the process rather than applying mathematics for its own sake.

I have research links with the mechanics group (Dr. J. Lammers, Dr. P.Slikkerveer) at Philips Research Laboratories http://www.research.philips.com. where I worked from 1986-1993. The collaboration has continued both directly and via postgraduate students and we have jointly developed mathematical models for coating processes of interest to Philips in particular concentrating on the coating of television screens and CRTs. Philips Research provides great expertise both on the theoretical and experimental side and its uniformly high research standards have influenced me greatly.

Indeed my approach to mathematical modelling owes a lot to the Oxford Centre for Industrial and Applied Mathematics where I obtained a D.Phil. under the supervision of Alan Tayler.

Mathematics Applications Consortium for Science and Industry (MACSI)

MACSI was set up as a Science Foundation Ireland (Mathematics Initiative) funded project (of which I was the Principal Investigator) to establish a network of industrial applied mathematicians in Ireland, with the group at the University of Limerick at the hub. The grant awarded was the largest ever to mathematics in Ireland (Eur 5m) under SFI's mathematics initiative. The grant extended from 2006-2013. The MACSI group solves problems posed by collaborators from science, engineering and industry. In 2008, 2009, 2010, 2011, 2012, 2013 we held study groups with industry (problem solving for industry workshops). There will another at UL from June 28-July 3 2015. In January 2013, I was lead applicant of a team grant of Eur 2.1m (+600k in overheads) awarded under the SFI Investigator Programme. This will be used to fund a range of activities in applied and industrial mathematical modelling.

European Consortium for Mathematics in Industry (ECMI)

The European Consortium for Mathematics in Industry (ECMI) is a consortium of academic institutions and industrial companies that acts co-operatively to promote and support the use of mathematical models in any activity of social or economic importance, to educate Industrial Mathematicians to meet the growing demand for such experts, to operate on a European scale. I was vice president from 2012-2013 and am currently serving as president (2014-1015). Dietmar Hoemberg is the current vice president and will become president in 2016. The ECMI BLOG is at http://www.ecmiindmath.org

Applied mathematical modelling (MACSI)

The terms "industrial mathematics", "applied mathematics" and "mathematical modelling" are often used as near synonyms to make the distinction with pure mathematics whose central tenet is formal proof and which is not generally concerned with real problems arising outside of mathematics. An applied mathematician is a kind of lapsed pure mathematician in the sense that he/she would like to prove every result formally but is sometimes unable to do so and must make intuitive leaps in the search for understanding. Otherwise, for example, the flow of air over airplane wings would not be understood. In fact applied mathematical modelling does not specify a novel kind of mathematics, but rather a philosophy of asking how things work. Emphasis is placed on the application of mathematics in non-mathematical disciplines, e.g., in finance, economics, biology, physics, chemistry or industry (which can be considered a complex world in itself often embracing all of the above disciplines). A process or phenomenon occurs outside mathematics and mathematics is used to explain, to understand or to improve it. The emphasis then is not on the mathematics itself, but on the use of mathematics to understand a phenomenon in a non-mathematical world. Mathematical modellers perceive themselves as being scientists as well as mathematicians and are interested in other disciplines apart from mathematics. Without this philosophy, most modern technology would not exist: airplanes would not fly, man would not have reached the moon, there would be no radar imaging nor scientific weather forecasts. Modern mathematical models help to quantitatively explain how ultrasound works, how diseases spread, how bubbles move in a pint of stout, how quickly spilt fuel on an airport runway percolates through the underlying soil, how wet paint drips from a ceiling, how the prices of options change. There are even mathematical models for the dynamics of marriage!

Research Interests

My research interests include modelling of industrial problems, asymptotic methods, lubrication theory, free surface flows, Stokes flow, and porous flow.

Interested in postgraduate studies?
My direct line is 00 353 61 202644, my email is stephen dot obrien at ul dot ie. The basic entry requirement for postgraduate study is to be well motivated and to have a good degree in a numerate discipline, mathematics, physics or engineering with a strong mathematical content. I tend to work on modelling real world physical problems (see example below) so a background in physics or engineering is not a disadvantage.

Typical Postgraduate Projects
Michael Hayes (2001), Asymptotic and numerical modelling of thin film flows, PhD.
Michael Chapwanya (2005), Models for bioremediation, Ph.D.
Sean Lacey (2007), Modelling of rimming flows, Ph.D.
Marguerite Robinson (2007), Flow regime transitions in two phase flows, Ph.D.
Vincent Cregan (2011) Boundary value problems in the food industry, Ph.D.

Typical Postgraduate Projects
Michael Hayes (2001), Asymptotic and numerical modelling of thin film flows, PhD.
Michael Chapwanya (2005), Models for bioremediation, Ph.D.
Sean Lacey (2007), Modelling of rimming flows, Ph.D.
Marguerite Robinson (2007), Flow regime transitions in two phase flows, Ph.D.
Vincent Cregan (2011) Boundary value problems in the food industry, Ph.D.
Michael Hayes (2001), Asymptotic and numerical modelling of thin film flows, PhD.
Michael Chapwanya (2005), Models for bioremediation, Ph.D.
Sean Lacey (2007), Modelling of rimming flows, Ph.D.
Marguerite Robinson (2007), Flow regime transitions in two phase flows, Ph.D.
Vincent Cregan (2011) Boundary value problems in the food industry, Ph.D.
Michael Hayes (2001), Asymptotic and numerical modelling of thin film flows, PhD.
Michael Chapwanya (2005), Models for bioremediation, Ph.D.
Sean Lacey (2007), Modelling of rimming flows, Ph.D.
Marguerite Robinson (2007), Flow regime transitions in two phase flows, Ph.D.
Vincent Cregan (2011) Boundary value problems in the food industry, Ph.D.

Bubbles in Guinness and roll waves on an inclined road are scientifically very similar phenomena.

Photograph and asymptotic estimate of the effect of an intrusive sensor under a bandage in tension. Interested in Postgraduate studies?

Green's function computation and photograph of disturbance in thin film flow over a point defect on a television screen.If you are interested in obtaining postgraduate qualifications (Ph.D, M.Sc.) by research in applied mathematics, feel free to contact me for an informal discussion. See also Waves in Guinness,

Professional Activities

Association

President (2014-2015), The European Consortium for Mathematics in Industry (ECMI)

Peer Reviewed Journals

2013

Temperature evolution in a partially submerged approximate cheese cylinder

Cregan, V,O'Brien, SBG,Charpin, JPF,Cronin, K (2013) Temperature evolution in a partially submerged approximate cheese cylinder. Journal Of Food Engineering :398-406

Biography

Research Interests

Professional Activities

Association

Publications

Peer Reviewed Journals

Temperature evolution in a partially submerged approximate cheese cylinder

Temperature evolution in a partially submerged approximate cheese cylinder

Extended asymptotic solutions to the spin-coating model with small evaporation

The MACSI summer school: a case study in outreach in mathematics

On rimming flows with shocks

Asymptotic, numerical and approximate techniques for a free boundary problem arising in the diffusion of glassy polymers

MATHEMATICAL MODELLING OF A SOLID PARTICLE MOTION IN A RE-CIRCULATORY FLUIDISED BED UNIT

Lin & Segel's Standing Gradient Problem Revisited: A Lesson in Mathematical Modeling and Asymptotics

Acid polishing of lead glass

A simple model for multicomponent etching

Modelling of particle motion in an internal re-circulatory fluidized bed

THE SHAPE OF A SMALL LIQUID DROP ON A CONE AND PLATE RHEOMETER

A perturbation solution for bacterial growth and bioremediation in a porous medium with bio-clogging

Smoothing of roll wave shocks by surface tension

Existence and stability of regularized shock solutions, with applications to rimming flows

Stability of regularized shock solutions, with applications to rimming flows

Multidisciplinary activities in a community mental health service: Relationship to health of the Nation Outcome Scale scores and diagnosis

Five-year follow-up of an evidence-based prescribing intervention

Waves in Guinness

Selection of processing temperature to minimize product temperature variability in food heating processes

A note on spin-coating with small evaporation

A note on spin coating with small evaporation.

Further self-interescting solutions of the pendant drop equations

Corner and start-up singularities in porous flow

Exploding solutions for three-dimensional rimming flows

A model for gravity driven flow of a thin liquid solid suspension with evaporation effects.

Does surface tension stabilize liquid films inside a rotating horizontal cylinder?

A model for gravity driven flow of a thin liquid-solid solution with evaporation effects

Inertial instability of a liquid film inside a rotating horizontal cylinder

Asymptotics of self-intersecting loop solutions of the pendant drop equations

Similarity solutions in groundwater flow.

Spin-coating over a small sinusoidal topography

Lithospheric failure on Venus

A new type of instability: explosive disturbances in a liquid film inside a rotating horizontal cylinder

A mathematical model for hammocking of a bandage on a limb

Asymptotics of a sequence of pendant drops

Numerical and asymptotic solutions for hammocking.

Asymptotic and numerical solutions for a hammocking model

A mechanism for linear instability in two-dimensional rimming flow

Linear stability of rimming flow

A model for dip-coating of a two liquid mixture.

A mechanism for two dimensional instabilities in rimming flow.

Pressure measurement under a bandage

An investigation of the hammocking effect associated with interface pressure measurements using pneumatic tourniquet cuffs

Evaporative and topographical effects in coating flows

Evaporative and topographical effects in coating flows.

Green's function for flow over a small two dimensional topography

Small exponent asymptotics

Green's function for steady flow over a small two-dimensional topography

Exponential asymptotics with a small exponent

Matched asymptotic expansion calculation of the equilibrium shape of a hole in a thin liquid film

The location of a shock in rimming flow

Asymptotics with small exponent in a model for ice-sheet surging

A model for the coating of cylindrical light bulbs.

Asymptotics of a pinhole

An implicit surface tension algorithm for picard solvers of surface-tension-dominated free and moving boundary problems

A mechanism for episodic subduction on Venus

The meniscus near a small sphere and its relationship to line pinning of contact lines

An implicit surface tension algorithm for surface tension dominated free and moving boundary problems.

NUMERICAL AND ASYMPTOTIC SOLUTIONS TO A MODEL FOR THE WATERPROOFING OF TELECOMMUNICATIONS CABLES

Using applied mathematics in industrial problems.

Asymptotic solutions for double pendant and extended sessile drops

On Marangoni drying: non-linear waves in a thin film

Surface tension and contact angle problems in industry. Journal of Adhesion Science and Technology

On the shape of small sessile and pendant drops by singular perturbation techniques

Shape of a small sessile drop and the determination of contact angle. Journal of the Royal Society: Faraday Transactions

A mathematical model for the cleansing of silicon substrates by fluid immersion

Anisotropic conduction of heat in a flowing polymeric material.

Particle removal by surface tension forces

A moving boundary problem in porous flow

Books

Book Chapters

Thin Film Flows: Theory and Modeling.

Explosive solutions in rimming flow.