Mark McGuinness

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Wc k,~ve undcr:aken a study ~,f the co~:~plex Lorenz equations. ~; =-crx + try. "y =(r-z)x-ay, =-bz, l(x*y + xy*). where x and y ace co~aplex and z is real. The complex parameters r and a are defined by r = rl + it,,: a = 1-ie and o" and b are real. Behaviour ~markably different from the real Lo~,~nz model occurs. Only the origin is a fixed point except for(More)
We develop a nonlinear delay-differential equation for the human cardiovascular control system, and use it to explore blood pressure and heart rate variability under short-term baroreflex control. The model incorporates an intrinsically stable heart rate in the absence of nervous control, and allows us to compare the baroreflex influence on heart rate and(More)
Recent experimental work has shown that, when a vertical column of rock under large pressure is suddenly depressurized, the column can 'explode' in a structured and repeatable way. The observations show that a sequence of horizontal fractures forms from the top down, and the resulting blocks are lifted off and ejected. The blocks can suffer secondary(More)
We report the first results from a programme recently set up to directly measure the thermal conductivity of young sea ice. An array of thermistors frozen into first-year Antarctic sea ice provides temperature against depth data, which is fitted directly with a partial differential equation for heat conduction. Temperatures are recorded every hour at twenty(More)
A new modified Galerkin / Finite Element Method is proposed for the numerical solution of the fully nonlinear shallow water wave equations. The new numerical method allows the use of low-order Lagrange finite element spaces, despite the fact that the system contains third order spatial partial derivatives for the depth averaged velocity of the fluid. After(More)
Spatial oscillations in soil contaminant concentration profiles are sometimes observed, but rarely commented on, or are attributed to noisy data. In this paper we consider a possible mechanism for the occurrence of oscillatory reactant profiles within contaminant plumes. The bioremediative reactions which occur are effected by bacteria, whose rôle is(More)
(25 articles) biogeochemistry (99 articles) mathematical modelling Articles on similar topics can be found in the following collections Email alerting service here the box at the top right-hand corner of the article or click Receive free email alerts when new articles cite this article-sign up in We provide and analyse a model for the growth of bacterial(More)