• 한국세라믹학회지
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• 제35권12호
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• pp.1337-1342
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• 1998

To investigate an effect of phase separation on precipitation characteristics of ZnS microcrystals in ma-trix glass ZnS doped borosilicate glasses for nonlinear optical applications were prepared by melting and pre-cipitation process. ZnS dopant contributed to phase separation promotion which increased the phase separa-tion of the matrix glass within immiscibility region. It was also found that ZnS as phase separation promoter showed a similar contribution for some selected glass compositions in miscibility region. The precipitation of ZnS microcrystals occurred in thephase separable glass compoitions. The radius of ZnS microcrystals in-creased with increasing the heat treatment temperature and Na2O contents of matrix glass composition. The ZnS particle sizes estimated by effective mass approximation ranged from about 30 to 80${\AA}$ It was suf-ficiently small to show quantum confinement effect.

• 생명과학회지
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• 제8권2호
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• pp.145-157
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• 1998

We isolated 100 Vobrio sp. from marine products and sea from July to September, 1997. We attemped on purification of hemolysin produced by Vibrio sp. The growth, hemolysin production patterns by the 100 strains of Vibrio sp. showed identical, in general. V. unlnificus ys-1 produced hemolysis as the higtest titer. The optimal culture conditions for the hemolysin production by the V. vunificus ys-1 are followings; 1. Hemolysin production was optimal dering the late exponetial phage. 2. Maximal growth, hemolysin production were in heart infusion broth. 3. Maximal yields of hemolysin was obtained when the heart infusion broth had an intial pH of 8.0, 3$0^{\circ}C$, 3% NaCL. Hemolysin was purified from culture filtrate of the strain by ammonium sulfate recipitation, ion exchange and hydrophobic interaction chromatography. The results were as follows; 1. Hemogeneity of the purified hemolysin was demonstrated by revealing single band on SDS-PAGE. The molecular weight of purified hemolysin was 45KDa. 2. The absorbance rattern in ultraviolet wsa typical of those seen with most proteinb with 280nm. 3. Purified hemolysin was atable at 5$0^{\circ}C$ but 7$0^{\circ}C$ of the acivity was lost by heating for 30 min at 6$0^{\circ}C$/ Optimal temperature of purified hemolysin was 35$^{\circ}C$. 4. Purified hemolysin was stable at the pH range of 6~9, but in the less the pH5.0. above the pH 9.0, the hemolysin activity was lost completely.

• 한국작물학회지
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• 제34권2호
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• pp.163-169
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• 1989

잎담배품질(등급별 수량분포비율)에 관여하는 개별 기상환경요인의 영향도 및 관계를 시기별로 분석한 바 그 결과는 다음과 같다. 1. 부엽 고품질인 1∼2등엽의 수량분포비율은 34.6％이고 저품질인 4∼5등엽은 40.4％이었다. 2. 품질등급별 수량분포비율의 년차변이는 5등엽에서 가장 높았고 2등엽에서 낮은 변이를 나타냈다. 3. 기상환경요인중 시기별 년차변이는 강수량과 일조시수에서 높았으며 최고기온에서 가장 낮았다. 4. 강수량은 6월 상순 > 5월 하순 > 6월 하순순으로 년차변이계수가 높았다. 5. 일조시수는 7월 하순 > 6월 하순순으로 년차변이계수가 높았다. 6. 고품질엽의 수량분포비율에 미치는 시기별 기상요인의 영향도를 보면, 가) 평균기온 : 정방향으로는 5월 하순과 중순에서 영향도가 크고 부방향으로는 5월 하순과 6월 상순에 크게 나타났다. 나) 일조시수 : 정방향으로는 6월 중순 > 6월 하순 > 5월 하순순으로 영향도가 크고 부방향으 영향도순은 5월 상순> 5월 중순이었다. 다) 강수량 : 정방향의 영향도순위는 5월 상순 > 5월 하순 > 5월 중순이고 부방향은 6월 중순과 6월 상순에서 영향도가 크게 나타았다.