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The United States Bureau of Reclamation (USBR) extensively studied hydraulic jump-type stilling basins for various inflow and tailwater conditions. They recommend Basin III using chute blocks, rectangular baffle blocks, and sloping end sill for medium to high dams. However, a significant contribution to the knowledge regarding the production of turbulence in discontinuity layers, the dissipation of energy, the convection, and the decay of turbulence in hydraulic jump was made by subsequent researchers. However, while developing the stilling basin, the wake formed by the jets separating at the front corners of the rectangular baffle blocks in Basin III and reattaching the downstream of the blocks was not considered. The use of Basin III was found limited to lower dams since cavitation of the baffle blocks was observed in many dams. After that, the use of wedge-shaped baffle blocks below a model spillway was systematically investigated. It was noticed that baffle blocks with a vertex angle of 1200 cut back at 900; the separating jets do not reattach downstream. Due to the wedge shape (super-cavitating), the low-pressure cavities do not collapse on the boundary. The new forms of baffle blocks are found to offer more drag to the flow when compared to rectangular blocks. Model tests were conducted to evolve stilling basins using the new baffle blocks and were highly successful. For example, in a stilling basin with an Inflow Froude Number of 7.07, with new blocks, a floor-length of about half the earlier suggested length is found to have better characteristics of scouring and sweep-out depth as compared to USBR Stilling Basin III.

Beaches in India and elsewhere are getting destroyed at an alarming rate as many small ports are being built and sea walls are coming up on the banks. There is an urgent need to stop it. In 1966, Posey used cylinders of net filled with rock (called rock sausages) underlain by a reverse gravel filter for safety against scour in hydraulic structures. Pillai used a bed of stones enclosed in nets underlain by a reverse filter to allow overflow over a sand embankment. Later it was understood that a Polypropylene Fabric (P.F.) could be effective as a filter, and a bed of polypropylene bag filled with sand (like geo-tubes) can be used to prevent scour. However, the P.F. get weathered when exposed to sunlight. A breakthrough came when porous concrete blocks with high porosity, high strength and seawater resistance were developed and were used underlined by a P.F. An attempt was made in an experimental study on the Cheriathura Beach at Trivandrum. Porous concrete blocks 0.5 m X 0.5m, 10 cm thick were cast and arranged at a time of low tide, covering an area of 10 m x 5 m (with the P.F. underneath). When the waves acted frontally during high tide, this rode smoothly on the pavement, had their run-up, and later receded without displacing the slabs. This showed that porous concrete slabs could be a good armour for protecting the beach. The side slabs got displaced with lateral waves because no sidewall could be provided in the narrow strip of protection. It is felt that the porous concrete slabs can be placed deep in the beach so that during the erosive phase, the slab could function as armour, and when there is accretion, there would be deposition of sand on the slabs maintaining the beach.

Traditionally, there are two basically reciprocal energy efficiency Indicators: one, in terms of energy intensity, that is, energy use per unit of activity output, and the other, in terms of energy productivity, that is, activity output per unit of energy use. The enquiry that has proceeded from the problems associated with this method of a single energy input factor in terms of productivity has led to multi-factor productivity analysis. We have here two approaches: parametric and non-parametric. Parametric approach famously includes two methods: the erstwhile popular total factor energy productivity analysis and the currently fanciful stochastic frontier production function analysis; The non-parametric approach is popularly represented by data envelopment analysis. The present paper is an attempt to measure efficiency in electrical energy consumption in Kerala, India. We apply the non-parametric mathematical programming method of data envelopment analysis of the multi-factor productivity approach, and estimate the efficiency measures under the two scale assumptions of constant returns to scale (CRS) and variable returns to scale (VRS); the latter includes both increasing (IRS) and decreasing returns to scale (DRS). Scale efficiency measures are also given to find out whether a firm is operating at its optimal size or not, implying degrees of capacity utilization.

This journal issue summarizes teacher education trends which are related to curriculum development in Asia and other foreign countries. The tendency in Asia to unite all types and levels of teacher education under a single authority has the potential either for a cooperative state board with representatives from the universities, teaching profession, and state government or for a state-controlled board which might threaten academic freedom. While there are also trends in Asia toward upgrading qualifications for entering teacher education programs and broadening the curriculum, there are problems in getting competent teachers and balancing the curriculum among community development work, languages (especially in multilingual countries), and general and professional study. Other foreign countries are also said to share Asian educators' concern over whether or not all teachers should be required to study some subjects in depth, thereby giving them mobility between elementary and secondary levels. Trends and innovations cited outside of Asia include microteaching, simulation, feedback during practice teaching with walkie talkies, curriculum development centers, elimination of laboratory schools, 5-week projects to improve local school facilities, and staff borrowing between colleges and schools. (Related to SP 003 941, in this issue.) (LP)