The UK Government has supported a programme on Renewable Energy since 1975. In 1988 progress was reviewed and this led to some redirection of the programme with greater emphasis on the commercial development of renewables, as published in Energy Paper 55.

The structure and phase behaviour of a colloidal dispersion of plate-like particles are described. The plates are nickel (II) hydroxide and have short-range, repulsive interactions and a low polydispersity. As the concentration of the plates is increased, an equilibrium phase separation between...

The paper follows from work by Quispel and Capel on “local reversibility” of a dynamical system. The approach adopted is to write down conditions for a mapping to behave like an involution in the neighbourhood of a fixed point and then to combine mappings which satisfy these conditions, thus...