David A. Jenkins

The contact stabilization activated sludge process—oxygen utilization, sludge production and efficiency

Abstract A kinetic model of the contact stabilization process has been developed and experimentally verified with the aid of bench-scale activated sludge units treating domestic sewage. The model provides information on the relationship between the design parameters (process loading, temperature, residence time distribution) and process performance (sludge, production, oxygen uptake, COD-removal, organic nitrogen conversion, nitrification and effluent suspended solids). An oxygen equivalence mass balance equation, which is applicable to all activated sludge process modifications is proposed and may be used in the design and operation of these processes.

MODIFICATIONS TO MECHANICAL AND MINERALOGICAL COMPOSITION OF SOIL WITHIN THE RHIZOSPHERE

Summary During an experimental study of rhizosphere development around French Bean roots, mechanical and mineralogical modifications were recorded. The former entailed a relative decrease in material 63 — 6.3μm e.s.d. in size, probably due to disaggregation of polymineralic shale particles. The latter was most obvious in the finest (

Kinematics of threshold (. gamma. ,. pi. /sup 0/) reactions

The kinematics for the (..gamma..,..pi../sup 0/) reaction near threshold is discussed. The pion formed in this reaction decays into two gammas whose angular distribution can be calculated from the pion differential cross section. The sensitivity of the angular distribution of the two gammas to various models of the reaction on /sup 6/Li is shown.

THE KINEMATICS OF THRESHOLD (gamma, pi0) REACTIONS

The kinematics for the (..gamma..,..pi../sup 0/) reaction near threshold is discussed. The pion formed in this reaction decays into two gammas whose angular distribution can be calculated from the pion differential cross section. The sensitivity of the angular distribution of the two gammas to various models of the reaction on /sup 6/Li is shown.