Alexandru Rap: Research Interests: Previous work

The project, funded by the UK Met Office Hadley Centre, focused on improving the parameterisation of aerosol-cloud interactions for global climate modelling. The other people involved in the project were Prof. Mike Smith (Principal Investigator) and Dr. Sat Ghosh.

A few results from our parameterisation from Rap et al. (2009), JAS and Ghosh et al. (2007), Phil. Trans. Roy. Soc.:

CDNC values as a function of sulphate aerosol mass concentration predicted by the model runs (solid black squares) and the following parameterizations: new scheme (solid), JRS94 (dotted), BL95 (short dashed), GN00 (dashed dotted), MD02 (dashed triple dotted), and QB05 (long dashed). This case considers fixed aerosol mass loadings of 0 ug m-3 sea salt and 0 ug m-3 biomass smoke.

CDNC values predicted by the model to nucleate from the three aerosol species as a function of sea-salt aerosol mass concentration. This case considers fixed aerosol mass loadings of 1.3 ug m-3 sulfate and 2.3 ug m-3 biomass smoke.

CDNC values as a function of sea-salt aerosol mass concentration predicted by the model runs (solid black squares), the new parameterizations scheme (solid line), and the JRS94 parameterization (dotted). This case considers fixed aerosol mass loadings of 1.3 ug m-3 sulfate and 2.3 ug m-3 biomass smoke.

My main interest has been concentrated on inverse contaminant fluid flow problems. The shortest definition of inverse problems describes them as discovering the cause from a known result. Inverse problems are of an interdisciplinary nature and arise in almost all research fields of science and engineering. The main objective of my research as a PhD student has been to extend the range of applications of the Boundary Element Method (BEM) and the Dual Reciprocity Boundary Element Method (DRBEM) for solving some inverse problems related to water pollution. The inverse problems considered in my research require the determination of the location and strength of point sources of pollution (inverse source problems) or boundary conditions for some hostile part of the boundary (Cauchy problems). During my research I have addressed these problems by developing a series of efficient algorithms which combine the BEM and DRBEM with regularisation techniques, such as Tikhonov regularisation, Truncated Singular Value Decomposition (TSVD) or an iterative procedure based on a Sequential Quadratic Programming (SQP) method.

Work published in Rap et al. (2004), Rap et al. (2006), Rap et al. (2007), and Rap (2010).