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A process for co-production of a pitch for the manufacture of HP carbon fibers and a pitch for the manufacture of GP carbon fibers is proposed. The pitch for the manufacture of GP carbon fibers is prepared from the spent fraction not used in the production of an optically anisotropic pitch suitable for the manufacture of HP carbon fibers. The spent fraction has hitherto been discarded as a valueless material. According to the present process, a pitch for the manufacture of so-called ultra HP carbon fibrs with tensile strength of over 400 Kg/mm² and modulus of elasticity of over 60 ton/mm′ and a pitch for the manufacture of GP carbon fibers can be produced simulteneously. Both pitches have very excellent spinnability and when they are spun, they cause no fiber cut-off even at a high spinning rate of, for example, 500 m/min or 700 m/min. One important merit of the process is that the production ratio of ultra HP carbon fibers and GP carbon fibers can easily be changed to accommodate to market's demand. Accordingly, the process has wide flexibility in operation. Of course, the effective utilization of valueless spent fraction can reduce the production costs of not only ultra HP carbon fibers but also GP carbon fibers.

The purpose of this study was to estimate masticatory efficiency of complete denture wearers. The subjects were 72 patients, treated before 5-10 years at students' clinic of Tsurumi University, School of Dental Medicine. The masticatory efficiencies with peanuts and Kamaboko were calculated. Results 1. The mean masticatory efficiency with peanuts for 63 patients was 35.8%, and with Kamaboko (steamed fishpast) for 64 patients was 94.5%, in comparison with natural dentition. 2. The mean masticatory efficiency with peanuts was 124.3%, and with Kamaboko was 99.6%, for complete denture wearers. 3. Comparing the measured value of masticatory efficiency with 5 to 10 years wearing period, there was significant difference in the masticatory efficiency between peanuts and Kamaboko. 4. There was significant difference in the masticatory efficiency with peanuts between the group needed new denture and the group not needed but there was not significant difference with Kamaboko.

Current distribution was examined by applying direct current in the vertical type electrolytic cell containing sulfuric acid with an anode of a long aluminum sheet. It was carried out by the measurement of thickness of anodic oxide coating and color difference in dyed specimens and by the observation of burnings of anode.Current distribution was more uniform when the concentration of acid was higher, the concentration of aluminum was lower, anodizing temperature was higher, anode current density was lower, and circulation velocity of electrolyte was higher. When the current density was extremely bad in uniformity, current passed through a certain point, at which burnings were produced. Shape and size of burnings would depend upon convection of heat generated on the anode. The two step raise of the current at the early stage of anodizing was effective for preventing the production of burnings. Moreover, studies were also made on the effects of arrangements of the electrodes.