This paper discusses the balanced circulation polytope, that is, the convex hull of balanced circulations of a given balanced flow network. The LP description of this polytope is the LP description of ordinary circulations plus some odd-set constraints. The paper starts with an exposition of several classes of odd-set inequalities. These inequalities are described in terms of balanced network f...

Positron emission tomography studies with oxygen-15-labeled water provide in vivo quantitative tissue perfusion variables-blood flow and fractional volume of distribution of water [V(d) (water)]. To investigate the relationship between perfusion variables and the effect of vascular-targeting agents on vasculature, we measured tissue perfusion in tumors, spleen, kidney, and liver before and afte...

A mass-conserving Level-Set method to model bubbly ows is presented. The method can handle high density-ratio ows with complex interface topologies, such as ows with simultaneous occurrence of bubbles and droplets. Aspects taken into account are: a sharp front (density changes abruptly), arbitrarily shaped interfaces, surface tension, buoyancy and coalescence of droplets=bubbles. Attention is p...

We study a defect correction method for the approximation of viscoelastic fluid flow. In the defect step, the constitutive equation is computed with an artificially reduced Weissenberg parameter for stability, and the resulting residual is corrected in the correction step. We prove the convergence of the defect correction method and derive an error estimate for the Oseen-viscoelastic model prob...

The aim of this study was to identify whether environmental flows released into two lowland rivers (the Glenelg and Wimmera Rivers, western Victoria, Australia) during the spring to autumn period had successfully ameliorated the negative effects of multiple human impacts. Macroinvertebrates and a range of physico-chemical variables were sampled from three reaches in each river. Both rivers were...

This paper tests for the importance of cash flow on investment in fixed capital and R&D using firm-level panel data in two countries between 1985 and 1994. For German firms, cash flow is not informative in simple econometric models of fixed investment or R&D. In identical specifications for British firms, cash flow is informative about investment, although not about the level of R&D spending co...