KARIMI, Iftekhar A. Professor PhD (Chem. Eng.) Purdue, 1984 MSc (Chem. Eng.) Purdue, 1982 BTech (Chem. Eng.) IIT Bombay, 1980 Contact information Blk E5, 4 Engineering Drive 4, #02-12, Singapore 117576 Tel: (65) 6516 6359    Fax: (65) 6779 1936 Email: cheiak@nus.edu.sg           RESEARCH Noncontinuous (batch, semicontinuous etc.) mode of chemical processing is well-suited for the production of multiple low volume, high value-added products. In contrast to the continuous processing, decisions allocating time, resources and facilities among the various products become crucial and are generally quite complex due to the multitude of possible product-resource-time combinations and the various operational constraints. The methodologies that are most commonly useful for these problems include mixed integer mathematical programming, discrete optimisation techniques, simulated annealing and specialised heuristic procedures. Since the number of products involved may often exceed several hundreds, one of the challenges is to develop methodologies suitable for solving large scale problems. Two broad areas of research are as follows:   Noncontinuous Process Design This deals with the design of multipurpose facilities in which each processing unit can process multiple products at different times and the units can be configured in many ways to form production lines. Given the demand forecasts for the various products and the units that can be used to produce each product, the goal is to develop methodologies for determining the number of processing units, their capacities and how they should be configured in the most cost-effective manner. The problem of retrofit design is especially important in today’s competitive environment where new products are continually introduced and one wants to get the most out of the existing facilities by either upgrading them or doing minimal changes. Production Planning and Scheduling Here we address the issue of how to utilise a given facility in the most cost-effective manner. Time as well as resources must be allocated to the various competing products. This could either be assigning production quotas to various facilities over months or years or it could involve assigning production to individual units over days or weeks. The objective is to develop methodologies that can effectively handle changing product slate, product demands, day-to-day orders, equipment maintenance/outages, resource constraints, transitions between products, inventory costs, penalty for not meeting the orders on time, etc. SELECTED PUBLICATIONS S. Farooq and I. A. Karimi, "Modeling Support Resistance in Zeolite Membranes", Journal of Membrane Science, 186, 109 (2001). B. S. Giri, M. B. Ray and I. A. Karimi, "Modeling and Monte-Carlo Simulation of TCDD Transport in a River", Water Resources, 35, 1263 (2001). S. R. Inamdar and I. A. Karimi, "Application of Reductive Perturbation Method to Branching of Stationary Solutions", Chemical Engineering Science, 56, 3915 (2001). N. Lamba, A. Bhalla amd I. A. Karimi, " Scheduling a Single Product Reentrant Process with Uniform Processing Times", Industrial Engineering Chemical Resources, 39, 4203 (2000). S. R. Inamdar and I. A. Karimi, "Two-parameter Periodic Solutions near a Hopf Point in Delay-Differential Equations", Journal of Physics A: Mathematical & General, 32, 4509 (1999).