Finding all vertices of a convex polyhedron

Summary The paper describes an algorithm for finding all vertices of a convex polyhedron defined by a system of linear equations and by non-negativity conditions for variables. The algorithm is described using terminology of the theory of graphs and it seems to provide a computationally effective method. An illustrative example and some experiences with computations on a computer are given.     

Lokale Wesentlichkeit von Abbildungen und eindimensionaler Zusammenhang von Polyedern

Ohne Zusammenfassung     

The spectrophotometric microdetermination of substances on paper disks

The principles and application of a method for the microdetermination of substances on small paper disks are described. Photometric measurements are made at 2 wavelengths, thus eliminating the errors due to inhomogeneity in the paper. A simple device for serial determinations that can be adapted to a common spectrophotometer is described. Microdetermination of RNA with measurement at 260 and 350 mμ is given as an example of the proposed method, and the best means of correcting the effect of paper inhomogeneity is established. Amounts of RNA in the range 0.8–4 μg can be determined with a mean error of ±0.03μg , using 5 μl of solution.