A microbeam plasma was successfully generated by using an originally designed capacitively coupled rf plasma reactor which was composed of a needle cathode (1 mm φ), a cylindrical anode (3 mm φ), and a quartz tubing inserted between the cathode and anode. When the reactor was operated in open air and helium was steadily fed as a discharge gas, a plasma beam (φ<2 mm) blew out into air. Conditions for generating a stable plasma were investigated. Preliminary results are presented on the etching of Si by this beam plasma, as well as an emission analysis of the etching plasma.

The deformation characteristics of soil subjected to vacuum pressure are discussed and an approximate method is proposed for calculating settlement and lateral displacement of the ground induced by vacuum consolidation. Laboratory oedometer test results indicate that if the vacuum pressure alone is larger than the lateral stress required to maintain an at-rest ͑no horizontal strain͒ condition, there will be inward lateral displacement and the vacuum pressure will induce generally less settlement than a surcharge load of the same magnitude. In the case of field vacuum consolidation, the confining stress acting on a soil element can be regarded as consisting of two parts: Due to vacuum pressure and earth pressure. Assuming a value of the lateral earth pressure coefficient acting in the ground under vacuum consolidation ͑k ao ͒, somewhere between the active and at-rest values, an equation defining the depth-below which there will be no significant inward lateral displacement-is derived. Further, assuming that the volumetric strain induced by vacuum consolidation is the same as the one-dimensional consolidation induced by application of a surcharge load of the same magnitude, an approximate method is proposed for calculating the ground settlement and inward lateral displacement induced by vacuum consolidation. This method has been applied to two case histories reported in the literature, and it is shown that the field-measured data are simulated reasonably well, suggesting that the method may be useful for the design of vacuum consolidation projects.

Heterocyclic conducting polymer films are prepared by the oxidative cationic polymerization of thiophene, pyrrole and furan. Electrical and optical properties of these polymer films are similar to those using electrochemically prepared polythiophene, polypyrrole and polyfuran.

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