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A series of controlled laboratory experiments are carried out in dual Teflon chambers to examine the presence of oligomers in secondary organic aerosols (SOA) from hydrocarbon ozonolysis as well as to explore the effect of particle phase acidity on SOA formation. In all seven hydrocarbon systems studied (i.e., alpha-pinene, cyclohexene, 1-methyl(More)
A mathematical model for the computation of chemical equilibrium of atmospheric inorganic aerosols is proposed. The equilibrium is given by the minimum of the Gibbs free energy for a system involving an aqueous phase, a gas phase and solid salts. A primal-dual method solving the Karush-Kuhn-Tucker conditions is detailed. An active set/Newton method permits(More)
— We consider optimal matching of submanifolds such as curves and surfaces by a variational approach based on Hilbert spaces of diffeomorphic transformations. In an abstract setting, the optimal matching is formulated as a minimization problem involving actions of diffeomorphisms on regular Borel measures considered as supporting measures of the reference(More)
A model that rigorously computes the gas-particle partitioning and liquid-liquid equilibrium for organic atmospheric aerosol particles is presented. The dynamics of the mass transfers between the particle and the gas phase are modeled with differential equations and are coupled with a constrained optimization problem for the thermo-dynamic equilibrium(More)
Air Quality Modelling is a recent important application that addresses several modern environmental health concerns. It requires considerable compute power to build, deploy and analyze the results of an air quality model and efforts to develop such applications can benefit from the availability of a computational grid. In this paper we discuss the needs of(More)
BACKGROUND A paucity of data exists on mitral valve (MV) deformation during the cardiac cycle in man. Real-time 3-dimensional (3D) echocardiography now allows dynamic volumetric imaging of the MV, thus enabling computerized modeling of MV function directly in health and disease. METHODS AND RESULTS MV imaging using 3D transesophageal echocardiography was(More)
In finance, hedging strategies are used to safeguard portfolios against risk associated with financial derivatives such as options. For an option with an underlying asset, the risk can be measured in terms of the so-called Greeks. In particular, the derivative of the option price with respect to the value of the asset is referred to as the Delta. An(More)