• Journal of Sericultural and Entomological Science
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• v.49 no.2
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• pp.47-50
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• 2007

Insect cell culture system has been demonstrated the effective means of producing medical and agricultural products. Furthermore, Fetal bovine serum (FBS) is in wide use in insect cell culture. Silkworm hemolymph was tested to develop as a substitute for FBS and was effective in insect cell growth. Hemolymph is oxidized and darkens visibly during the collection from silkworms due to the activity of tyrosinase in it. Toxic quinones are produced by the oxidation and consequently inhibit the cell growth. Heat treatment can be used to prevent the oxidation; however, the oxidation may occur during the collection of hemolymph before it is heat-treated. Hemolymphs collected from 257 different strains of silkworms were examined to select the slowly oxidized hemolymphs. Hemolymphs collected from mutant strains such as $Y_4$, TBO and $wE^b$ showed relatively slow color changes. Oxidation rates of the hemolymphs were measured by the absorbance change using a spectrophotometer. The absorbance of mutant hemolymph reached the saturation value at $20^{\circ}C$ in each 330 min ($Y_4$), 360 min (TBO) and 450 min ($wE^b$) min, whereas the total oxidation time of the wild-type (Baekokjam) hemolymph at the same temperature was 120 min. The cell growth in the medium supplemented with mutant species hemolmph was more effective that in the medium supplemented with Baekokjam species hemolymph.

• Korean Journal of Optics and Photonics
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• v.19 no.4
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• pp.255-261
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• 2008

In this study, the propagation characteristics and the fabrication tolerance of an optical wire in a flexible optical PCB were analyzed by using a ray-tracing method. It is found from the analysis that the sidewall angle of a core should be controlled within $1^{\circ}$ in order to maintain the propagation loss to less than -1 dB/mm, and that the bending radius of the optical wire should be larger than 5 mm in order to suppress the bending loss below -1 dB. In addition, it is confirmed that the lateral misalignment of ${\pm}15\;{\mu}m$, and the angular tilting of VCSEL of $6^{\circ}$ are allowable for the coupling loss of -1 dB.