Single Boundary Measurement Research Articles

Communication. Reverse flow injection or reagent injection? Normal flow injection, reverse flow injection and single-boundary measurements

The terms sample injection and reagent injection are inadequate in describing flow injection systems in which a monitorand that is not the determinand is produced on-line. The term reverse flow injection may not be self-evident, but terms such as normal flow injection and reverse flow injection can be used effectively to indicate whether a chemical species is in the injectate or the carrier stream, and whether a product is being formed by a concentration-limited species dispersing into or out of the bolus. Any term replacing the term reverse flow injection must be equally versatile. For flow analysis using a single boundary between two solutions there is a need for a term which indicates whether a chemical species, particularly if it is the determinand or a concentration-limited reagent forming a monitorand, is in the front or rear solution.

On the inverse conductivity problem with one measurement

The authors are looking for an open set D entering the coefficient of the elliptic equation div((1+chi (D)) Del u)=0 in a domain Omega when for one given non-zero Neumann data on delta Omega they know the Dirichlet data on a part of delta Omega (a single boundary measurement). Here chi (D) is the indicator function of D. They prove uniqueness for sets D which are convex cylinders or unions of discs whose centres are extreme points of the convex hull of those centres.