Abstract: A silicon nitride compact with a density of 95% to 100% is produced by forming a particulate dispersion of silicon nitride and beryllium additive into a compact, firstly sintering the compact from about 1900.degree. C. to about 2200.degree. C. in nitrogen at superatmospheric pressure sufficient to prevent thermal decomposition of the silicon nitride until the entire outside surface of the compact becomes impermeable to nitrogen gas, and then secondly sintering the compact from about 1800.degree. C. to about 2200.degree. C. under a nitrogen pressure having a value at least twice the first nitrogen sintering pressure.

Abstract: Low voltage varistors having one or more recesses or dimples which reduces the thickness of the varistor in the recessed areas are provided by an improved process which comprises fitting a pressing surface on a die punch with a resilient material, preferably an abhesive material such as polydimethylsiloxane, having one or more nipples whereby during pressing of a metal oxide varistor powder contained in the die cavity the nipple imparts a depression thereby reducing the thickness of the varistor body in said depression. In addition, the resilient material aids in the distribution of the powder during pressing and with the preferred abhesive material aids also in the release of the pressed body from the die.

Abstract: A mixed culture of thermophilic cellulolytic sporocytophaga and thermophilic ethanol-producing bacillus is admixed with a suspension of cellulose in nutrient mineral broth and the resulting mixture is fermented at a pH ranging from 7 to 8 and at a temperature of 50.degree. C to 65.degree. C to produce ethanol.