Particle breakage in stirred vessels is usually modeled using population balance equations (PBEs) to describe the evolution in particle size with time. Although shape has a strong effect on the particle properties and hence the product quality, changes in the particle shape distribution are typically neglected. To account for changes in both size and shape simultaneously, a multivariate populat...

Split cuts are among the most important and well-understood cuts for general mixed-integer programs. In this paper we consider some recent generalizations of split cuts and compare their relative strength. More precisely, we compare the elementary closures of split, cross, crooked cross and general multi-branch split cuts as well as cuts obtained from multi-row and basic relaxations. We present...

Population balances represent an effective framework for the analysis of rate processes in dispersed phase systems. Mainly, they are able to account for the dynamics of the dispersed phase because of particle breakup and agglomeration while concurrently accounting for the rate processes in single particles. The effectiveness of this framework depends on whether particle phenomena (such as break...

Programmed chromosome breakage occurs at 50-200 specific sites in the genome of Tetrahymena thermo-phila during somatic nuclear (macronuclear) differentiation. Previous studies have identified a 15 bp sequence, the Cbs (for chromosome breakage sequence), that is necessary and sufficient to specify these sites. In this study we determined the effects of mutations in the Cbs on its ability to spe...

This study focused on several wetlands in Laguna del Tigre National Park (Guatemala) as part of Conservation International's Rapid Assessment Program. Sediment and water samples were collected from a laguna near Xan field, Guatemala's largest oil facility, and three other sites for determination of levels of polycyclic aromatic hydrocarbons (PAHs). Cichlid fish (Thorichthys meeki and Vieja syns...