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Shin, Hae-Hun;Pyun, Yu-Ryang
- Korean Journal of Food Science and Technology
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- v.29 no.6
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- pp.1175-1183
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- 1997
Lethal effects of high voltage pulsed electric fields (PEF) on suspensions of Lactobacillus plantarum cells in phosphate buffer solution were examined by using continuous recycle treatment system. Critical electric field strength and treatment time needed for inactivation of L. plantarum were 13.6 kV/cm and $16.1\;{\mu}s$ at room temperature, respectively. As decrease in frequency (decreasing pulse number), the degree of inactivation of L. plantarum was increased. A 2.5 log reduction in microbial population could be achieved with an electric field strength of 80 kV/cm, 300 Hz frequency and $2000\;{\mu}s$ treatment time. Survivability was decreased with increase in total treatment time (cycle number) and frequency at the same cycle number. As sterilization model of continuous recycle PEF treatment, $logS=-N_m\;log\;m+B$ and $N_m=k_1\;P_n+k_2$ were established. This model was very well fitted to tile empirical data. The rate of inactivation increased with increase in the processing temperature. The maximum reduction in survivability (5.6 log reduction) was obtained with 80 kV/cm electric field strength at $50^{\circ}C$ for $1000\;{\mu}s$ treatment.
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Yun, Yong-Dae;Yang, Won-Ha;Kwang, Yong-Ho;Park, Seok-Hong;Park, Rae-Kyeong
- KOREAN JOURNAL OF CROP SCIENCE
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- v.31 no.1
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- pp.9-15
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- 1986
To establish an efficient light control method using three covering materials on tunnel shaped rice seed-bed at greening stage after seedling emergence, four rice cultivars, Nampungbyeo, Taebaegbyeo, Seonambyeo, and Seomjinbyeo were sown on 15 April and 10 May in 1983 and 1984 respectively. After seedling emergence by a simplified emerging methods the seedling boxes were moved onto tunnel shaped seed-bed which was covered with combined matrials of PE film, silverpoly sheet, and spunbonded polyester fabric. For machine transplanting of rice seedlings in cases of early season and optimum season seeding in central part of Korea, PE film tunnel with silverpoly mulched, and PE film tunnel methods with spunbonded polyester fabric mulched reduced injuries of non-parasitic seedling damping-off and a albinism as affected by it, protected rice seedlings from injuries by extremely low temperature in the night, and reduced less differences in diurnal temperature than those in the other covering methods. At late season seeding for double cropping system of paddy field in southern part of Korea, a single silver-poly or a single spunbonded polyester fabric-covered tunnel method showed good green seedlings, and prevent-ed extreme rising of diurnal temperature by light interception in the tunnel.
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Heo, Mun-Do
- The Korea Swine Journal
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- v.10 no.6 s.106
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- pp.89-94
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- 1988
신생자돈의 환경온도는 생시부터 7일까지 30-50$^{\circ}C$, 습도는 60-80%가 좋으며, 모돈은 12-23$^{\circ}C$ 범위이다. 한편, 방서대책의 원리로 돈사내의 기류를 촉진시켜 주고 복사열을 방지해야 한다
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