BEHAVIOUR OF FIXED CANTILEVER WALLS SUBJECT TO LATERAL SHAKING.

A programme of research on the seismic behaviour of retaining walls has been under way at Cambridge since 1981. Centrifuge tests have presently been conducted both on cantilever walls and isolated mass walls, retaining dry sands of varying grading and density. This paper is devoted to the modelling of fixed-base cantilever walls retaining Leighton Buzzard (14/25) sand of relative density 99% with a horizontal surface level with the crest of the wall. The base of the centrifuge container was used to fix the walls, and to provide a rigid lower boundary for the sand. No attempt was made to inhibit the propagation of compression waves from the side of the container opposite the inside face of the model wall. The detailed analysis of dynamic deflections and bending moments was made difficult by the anelastic nature of reinforced concrete, and the difficulty of measuring bending strains thereon. A supplementary programme of well-instrumented tests on Dural walls of similar stiffness, including the modelling of models, was therefore carried out. Refs.

Partial survey and critique of Ceylon's marine fisheries, 1953-55

This is a resume of a 1953-1955 study of Ceylon's fishing gears, fisheries and records of experimental and commercial fishing operations. Representative catches of edible fish per unit of effort for several of the gears studied are summarized in the table. They are low compared with many countries, indicating low abundance of fish.

Switching speed enhancement of the LDMOSFETs using partial-SOI technology

To overcome reduced breakdown voltage and self-heating effects inherent in silicon-on-insulator (SOI) power integrated circuits while still maintaining good isolation between low power CMOS circuits and the high power cells, partial SOI (PSOI) technology has been proposed. PSOI devices make use of both buried oxide and substrate depletion to support the breakdown voltage. 2D analyses and modeling of parasitic capacitances in PSOI structures show that PSOI-lightly doped MOSFETs can increase the switching speed by as much as four times compared to conventional SOI structures, making them very attractive for high switching applications.

Crystal growth of melt-textured Nd-123 under 1% oxygen partial pressure atmosphere

Crystal growth of melt-textured Nd-123 pseudo-crystals was investigated via an isothermal solidification with top-seeding technique under a 1%O2 in N2 atmosphere. Non-steady state solidification was observed at low undercooling, in contrast to an almost linear growth at higher undercooling. Similar to processing in air, the substitution of Nd/Ba was found to decrease from the seed position to the edge of the crystal. In addition, the volume fraction of Nd-422 particles decreased in the solid as solidification proceeded. As a result of these microstructural inhomogeneities, the critical temperature and the critical current density varied within the crystal even for samples processed isothermally, despite the narrow solid solution range of the Nd-123 phase under a reduced pO2 atmosphere.