Abstract: A fixing unit or device that can be used in an image forming apparatus includes a first heater element that is formed of a material that increases in electrical resistance with increases in temperature. A controller of the fixing unit is configured to vary a duty ratio of electric power applied to the first heater element during a start-up operation in which the temperature of the first heater element is raised to a target operating temperature. By varying the duty ratio during the start-up operation, changes in the resistance of the first heater element with the heating can be compensated. For example, the duty ratio can be increased during the course of the start-up to achieve the target operating temperature faster.

Abstract: A diaphragm electrolysis of an aqueous solution of sodium chloride is carried out by using a fluorinated cation exchange membrane which is made of a polymer having carboxylic acid groups as ion-exchange group and has 2.0 to 3.5 mole/Faraday of water permeability under the electrolysis.

Abstract: In a process for producing an alkali metal hydroxide which comprises electrolysis of an aqueous solution of an alkali metal chloride in an electrolytic cell having an anode compartment and a cathode compartment which are partitioned by a fluorinated cation exchange membrane, the improvement which comprises a fluorinated cation exchange membrane made of a fluorinated copolymer having carboxylic acid groups as the ion exchange group and having an ion exchange capacity of 0.5 to 2.0 meq/g dry polymer and a concentration of carboxylic acid groups of 8 to 30 meq/g water absorbed by the membrane when contacted with an aqueous solution of the alkali metal hydroxide having about the same concentration of alkali metal hydroxide as that of catholyte during said electrolysis.