Abstract: A process for the preparation of naphthalene mono or polycarboxylic acids, such as 2,6-naphthalene dicarboxylic acid, is disclosed which includes oxidizing a naphthalene compound such as 2,6-diisopropylnaphthalene in a specific solvent with molecular oxygen in the presence of a catalyst containing a heavy metal compound and a bromine compound. The solvent is an aliphatic monocarboxylic acid and may further contain benzene and/or water. By controlling the ratio of the amount of catalyst metal to the feed rate of the raw material naphthalene compound, the yield of desired product can be controlled.

Abstract: An indicating apparatus comprises a plurality number of indicating parts respectively having indicating elements which are operated to indicate and maintain their indicating states, indicating element driving circuits provided in respective indicating parts and adapted to drive said indicating elements respectively, a circuit for supplying indicating signals corresponding to an information to be indicated to respective indicating parts, and scanning driving means provided in correspondence with respective indicating parts and adapted to drive the indicating element driving circuits sequentially in a time-division manner in response to said indicating signals.