Teruo Sakamoto

Yusuke Suzuki; Toyohiko Takeda; Kunihei Inazu; Teruo Sakamoto

The mechanism of granularly agglomerated crystallization during freezing of cephalothin sodium (CET-Na) in aqueous solution has been discussed. Our previous report noted that strict control of the following is important in order to obtain crystalline granular agglomerates of CET-Na: (1) thermal history of the solution before receiving freezing, (2) cooling rate in freezing, and (3) aging temperature level in the crystal growth step. In order to clarify the physico/chemical meanings of the individual controls, further investigations have been made: 1) with varying thermal history, aqueous 30-% CET-Na solutions were prepared for storage, first at 0 degrees C with its supersaturation and secondly at 25 degrees C, in an unsaturated state for observing any structural changes by viscosimetry, refractometry, and surface tensiometry; 2) morphological changes in ice crystals during freezing at varying cooling rates, as well as those during the crystal growth step, were observed by polarized-light cryomicroscopy and scanning electron microscopy; 3) melting, as well as crystal growth, at several aging temperature levels were observed by electrical conductometry and also by the above-mentioned techniques.(ABSTRACT TRUNCATED AT 250 WORDS)

Yasushi Takagishi; Koji Sato; Keizo Tomita; Teruo Sakamoto

Kazufumi Fujiwara; Kenzo Iwamoto; Sadao Kawai; Teruo Sakamoto

Toyohiko Takeda; Yusuke Suzuki; Kunihei Inazu; Teruo Sakamoto; Hideyuki Maekawa

Yasushi Takagishi; Toshihiro Ogura; Keizo Tomita; Youko Ohkubo; Teruo Sakamoto

Yusuke Suzuki; Toyohiko Takeda; Kunihei Inazu; Teruo Sakamoto; Hideyuki Maekawa

Yasutaka Wada; Taiiti Mizuta; Teruo Sakamoto

Sadao Kawai; Kinsaburo Noda; Toshihiro Ogura; Teruo Sakamoto; Toyohiko Takeda

Hideyuki Maekawa; Teruo Sakamoto; Yoshihisa Sagawa

Hideyuki Maekawa; Teruo Sakamoto; Yasuo Shimada