A5008869620- Advanced Control Systems Optimization
- Process Optimization and Integration
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Crystallography and molecular interactions
- Scheduling and Optimization Algorithms
- Advanced Optimization Algorithms Research
- Machine Learning in Materials Science
- Computational Drug Discovery Methods
- Modeling and Simulation Systems
- Numerical methods for differential equations
- Fault Detection and Control Systems
- Phase Equilibria and Thermodynamics
- Thermodynamic properties of mixtures
- Chemical Thermodynamics and Molecular Structure
- Advanced Multi-Objective Optimization Algorithms
- Simulation Techniques and Applications
- Advanced Manufacturing and Logistics Optimization
- Methane Hydrates and Related Phenomena
- Advanced Chemical Physics Studies
- Optimal Experimental Design Methods
- Business Process Modeling and Analysis
- Protein Structure and Dynamics
- Reservoir Engineering and Simulation Methods
- Manufacturing Process and Optimization
Imperial College London
2015-2025
Siemens (United Kingdom)
2023-2024
Process Systems Enterprise (United Kingdom)
2001-2020
Centre for Process Innovation
2018
University College London
2009
Imperial Valley College
1997
Massachusetts Institute of Technology
1985
The initial values for Variables in mixed Differential-Algebraic (DAE) systems must satisfy not only the original equations system but also their differentials with respect to time. Whether or this additional requirement actually imposes extra constraints on Values depends particular problem. This paper derives a criterion determining whether differentiation of subset nonlinear DAE provides further be satisfied by values. A graph-theoretical algorithm is proposed locate those subsets which...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSolution of a Class Multistage Dynamic Optimization Problems. 1. Problems without Path ConstraintsV. S. Vassiliadis, R. W. H. Sargent, and C. PantelidesCite this: Ind. Eng. Chem. Res. 1994, 33, 9, 2111–2122Publication Date (Print):September 1, 1994Publication History Published online1 May 2002Published inissue 1 September 1994https://doi.org/10.1021/ie00033a014RIGHTS & PERMISSIONSArticle Views1873Altmetric-Citations335LEARN ABOUT THESE...
The sixth blind test of organic crystal structure prediction (CSP) methods has been held, with five target systems: a small nearly rigid molecule, polymorphic former drug candidate, chloride salt hydrate, co-crystal and bulky flexible molecule. This seen substantial growth in the number participants, broad range giving unique insight into state art field. Significant progress treating molecules, usage hierarchical approaches to ranking structures, application density-functional...
We consider the design of multiproduct, multi-echelon supply chain networks. The networks comprise a number manufacturing sites at fixed locations, warehouses and distribution centers unknown locations (to be selected from set potential locations), finally customer zones locations. system is modeled mathematically as mixed-integer linear programming optimization problem. decisions to determined include number, location, capacity up, transportation links that need established in network,...
Following the interest generated by two previous blind tests of crystal structure prediction (CSP1999 and CSP2001), a third such collaborative project (CSP2004) was hosted Cambridge Crystallographic Data Centre. A range methodologies used in searching for ranking likelihood predicted structures is represented amongst 18 participating research groups, although most are based on global minimization lattice energy. Initially participants were given molecular diagrams three molecules asked to...
Following on from the success of previous crystal structure prediction blind tests (CSP1999, CSP2001, CSP2004 and CSP2007), a fifth such collaborative project (CSP2010) was organized at Cambridge Crystallographic Data Centre. A range methodologies used by participating groups in order to evaluate ability current computational methods predict structures six organic molecules chosen as targets for this test. The first four targets, two rigid molecules, one semi-flexible molecule 1:1 salt,...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSolution of a Class Multistage Dynamic Optimization Problems. 2. Problems with Path ConstraintsV. S. Vassiliadis, R. W. H. Sargent, and C. PantelidesCite this: Ind. Eng. Chem. Res. 1994, 33, 9, 2123–2133Publication Date (Print):September 1, 1994Publication History Published online1 May 2002Published inissue 1 September 1994https://pubs.acs.org/doi/10.1021/ie00033a015https://doi.org/10.1021/ie00033a015research-articleACS PublicationsRequest reuse...
This paper considers the optimal design of thermally coupled distillation columns and dividing wall using detailed column models mathematical optimization. The model used is capable describing both conventional columns, which allows comparisons different structural alternatives to be made. Possible savings in operating capital costs up 30% are illustrated two case studies.
We report a multistage lattice energy minimization methodology for generating stable packing arrangements of cocrystals containing flexible molecules. In the first approximation, intermolecular electrostatic interactions are modeled with atomic charges and molecular deformation is interpolated over set precomputed quantum mechanical values. At subsequent stages, accuracy improved by using analytically rotated then conformation-dependent multipole moments, computed from isolated-molecule...
This paper presents a novel algorithm, CrystalOptimizer, for the minimization of lattice energy crystals formed by flexible molecules. The algorithm employs isolated-molecule quantum mechanical (QM) calculations intramolecular and conformation-dependent atomic multipoles in course minimization. eliminates need to perform QM at each iteration using Local Approximate Models (LAMs), with minimal impact on accuracy. Additional computational efficiencies are achieved storing QM-derived components...
With 12 crystal forms, 5-methyl-2-[(2-nitrophenyl)amino]-3-thiophenecabonitrile (a.k.a. ROY) holds the current record for largest number of fully characterized organic polymorphs. Four these polymorph structures have been reported since 2019, raising question how many more ROY polymorphs await future discovery. Employing structure prediction and accurate energy rankings derived from conformational energy-corrected density functional theory, this study presents first landscape that agrees...
A seventh blind test of crystal structure prediction was organized by the Cambridge Crystallographic Data Centre featuring seven target systems varying complexity: a silicon and iodine-containing molecule, copper coordination complex, near-rigid cocrystal, polymorphic small agrochemical, highly flexible drug candidate, morpholine salt. In this first two parts focusing on generation methods, many (CSP) methods performed well for but agrochemical compound, successfully reproducing...
Abstract A new methodology for the prediction of molecular crystal structures using only atomic connectivity molecule under consideration is presented. The approach based on global minimization lattice enthalpy crystal. modeling electrostatic interactions accomplished through a set distributed charges that are optimally and automatically selected positioned results quantum mechanical calculations. four‐step optimization algorithm used identification local minima surface. parallelized...
An extension of a recently reported algorithm (J. Comput. Chem., 26, 304 (2005)) for the prediction crystal structure organic materials to molecules whose conformation is likely be significantly affected by packing forces presented. The molecule modelled as set rigid fragments connected flexible torsion angles values in crystalline environment are determined balance intra- and inter-molecular forces. intramolecular energy initially computed using quantum mechanics over grid space angles....
Organic molecules can crystallize in multiple structures or polymorphs, yielding crystals with very different physical and mechanical properties. The prediction of the polymorphs that may appear nature is a challenge great potential benefits for development new products processes. A multistage crystal structure (CSP) methodology applied to axitinib, pharmaceutical molecule significant polymorphism arising from molecular flexibility. CSP study focused on those one asymmetric unit. approach...
Controlling the physical properties of solid forms for active pharmaceutical ingredients (APIs) through cocrystallization is an important part drug product development. However, it difficult to know a priori which coformers will form cocrystals with given API, and current state-of-the-art cocrystal discovery involves expensive, time-consuming, and, at early stages development, API material-limited experimental screen. We propose systematic, high-throughput computational approach primarily...