• 한국식품영양학회지
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• 제17권3호
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• pp.286-293
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• 2004

가시오가피, 구기자, 당귀, 오미자의 열수 추출물이 유산균의 생육과 동결건조시 보호제로서의 역할 및 동결건조된 유산균원료의 저장 시 생존율에 미치는 영향을 조사하였다. MRS 배지에 생약 추출물을 첨가한 경우 유산균주 16종에 대하여 가시오가피, 구기자, 당귀 및 오미자 추출물을 MRS broth에 각각 50%(v/v)씩 첨가한 배지에서의 생육상태를 조사하였다. 가시오가피 추출물을 첨가한 경우 L. acidophilus, L. bulgaricus, L. paracasei, L. casei, L. pentosus 균주가 생육이 양호하였으며 구기자 추출물을 첨가한 경우 L. acidophilus, L. bulgaricu L. paracasei 등이 양호하였고 당귀 추출물에서는 L. acidophilus, L. bulgaricus, L. casei, L. plantarum, L. lactis 등이 잘 생육하였으며 오미자 추출물에서는 L. acidophilus, L. rhamnosus, L. pentosus 등이 양호하였다. 기본 동결보호제로 조성으로 구성된 skim milk 10%(w/v)와 sucrose 5%(w/v)에 생약 추출물 2.5%(v/v)를 첨가한 경우 동결건조 직후 생존율은 L. acidophifus, L. bulgaricus, L. paracasei, L. casei가 평균 각각 81.7%, 63.8%, 73.2%, 78.1%를 나타냈다. 동결건조한 유산균 원료를 온도 4$0^{\circ}C$, 습도 70% 유지하는 항온항습기에서 한달간 방치시킨 후 생존율은 L. acidophilu의 경우 대조군에 비해 약 6%, L. paracasei와 L. bulgaricu의 경우 약3%의 생존율 증가를 보여 가혹조건에서 균의 생존율을 연장시키는데 역할을 하는 것으로 보이며, 구기자 추출물을 2.5% 첨가하여 동결건조 한 균 원료의 경우 L. paracasei에서 약 1.5% 정도 증가를 나타냈으며 L. aoidophilus와 L. bulgariolis에서는 약 1% 정도 감소하는 경향을 보였다. 특히, 구기자 추출물의 경우 L. acidophilus와 L. bulgaricus에서 당귀 추출물의 경우 L. bulgaricu와 L. casei에서 동결 보호제로서 이용할 수 있을 것으로 사료된다.

• 한국통신학회논문지
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• 제29권3A호
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• pp.303-310
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• 2004

본 논문에서는 5.15-5.35㎓ 대역의 무선 LAN용 L-슬롯 마이크로스트립 안테나를 설계 제작하였다. 정사각 패치에 사이즈 감소를 위해 4개의 L-슬롯을 갖도록 하였으며 접지면과 기판사이에 공기층을 삽입하여 VSWR＜1.5에서 적절한 대역을 얻고자 하였다. 설계시 주요 파라미터는 L-슬롯의 길이, 폭, 위치와 공기층의 두께 및 급전위치였으며 최적화된 파라미터를 가지고 실제 제작 및 측정하였다. 제작된 안테나의 측정결과는 다음과 같다. 공진 주파수는 5.25㎓이고, VSWR＜1.5에서 5%의 대역폭과 8-9㏈i의 이득을 얼었다. H-평면과 E-평면에서 각각 69$^{\circ}$와 62$^{\circ}$로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제31권5호
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• pp.717-725
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• 2021

This study aimed to optimize medium composition and culture conditions for enhancing the biomass of Lactobacillus plantarum 200655 using statistical methods. The one-factor-at-a-time (OFAT) method was used to screen the six carbon sources (glucose, sucrose, maltose, fructose, lactose, and galactose) and six nitrogen sources (peptone, tryptone, soytone, yeast extract, beef extract, and malt extract). Based on the OFAT results, six factors were selected for the Plackett-Burman design (PBD) to evaluate whether the variables had significant effects on the biomass. Maltose, yeast extract, and soytone were assessed as critical factors and therefore applied to response surface methodology (RSM). The optimal medium composition by RSM was composed of 31.29 g/l maltose, 30.27 g/l yeast extract, 39.43 g/l soytone, 5 g/l sodium acetate, 2 g/l K₂HPO₄, 1 g/l Tween 80, 0.1 g/l MgSO₄·7H₂O, and 0.05 g/l MnSO₄·H₂O, and the maximum biomass was predicted to be 3.951 g/l. Under the optimized medium, the biomass of L. plantarum 200655 was 3.845 g/l, which was similar to the predicted value and 1.58-fold higher than that of the unoptimized medium (2.429 g/l). Furthermore, the biomass increased to 4.505 g/l under optimized cultivation conditions. For lab-scale bioreactor validation, batch fermentation was conducted with a 5-L bioreactor containing 3.5 L of optimized medium. As a result, the highest yield of biomass (5.866 g/l) was obtained after 18 h of incubation at 30℃, pH 6.5, and 200 rpm. In conclusion, mass production by L. plantarum 200655 could be enhanced to obtain higher yields than that in MRS medium

• Fisheries and Aquatic Sciences
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• 제5권2호
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• pp.79-86
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• 2002

Listeria spp. were isolated from the samples submitted from various seafood plants such as raw materials, products, swab samples of plants floor and conveyor belts through the whole processing procedures. All the samples were collected from 3 kinds of seafood plants such as a imitation crab meat plant, jeotgal plant and frozen seafood plant. And also serotypes of the identified L. monocytogenes were determined. Among the 301 strains of isolated Llsteria spp., 96 strains, 179 strains and 26 strains were identified as L. monocytogenes, L. innocua and L. welshimeri, respectively. While among the 145 strains of Listeria spp. isolated from the imitation crab meat plant, $74\;(51.0\%)$ strains, $64\;(44.1\%)$ strains and $7\;(4.8\%)$ strains were identified as L. monocytogenes, L. innocua and L. welshimeri, respectively. In the case of the 126 strains of Listeria spp. isolated from the frozen seafood plant, $22\;(17.5\%)$ strains of L. monocytogenes,$93\;(73.8\%)$ strains of L. innocua, and $11\;(8.5\%)$ strains of L. wdshimeri were detected. Among the 30 strains isolated from a jeotgal plant, $22\;(73.3\%)$ strains of L. innocua and $8\;(26.7\%)$ strains of L. welshimeri were detected. The detection rates of L. monocytogenes, one of the very important food poisoning bacteria especially in frozen and/or refrigerated seafoods, were relatively high as $77.1\%$ (74/96 strains) in a imitation crab meat plant and $22.9\%$ (22/96 strains) in a frozen seafood plant, but not detected from jeotgal plant. Distribution of L. monocytogenes serotypes and characterization were examined. The serotypes of 96 L. monocytogenes isolated from pork skin, pork fat, the floor and conveyor belts were 1/2a $(59.4\%)$, l/2b $(6.2\%)$, 1/2c $(12.5\%)$ and unknown serotypes $(21.9\%)$. Unknown serotypes were divided into three specific groups by the O antigen they have.

• Journal of Plant Biotechnology
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• 제45권1호
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• pp.55-62
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• 2018

In the present study in vitro mutagenesis was used to study the effect of gamma irradiation and EMS on callus induction, morphogenesis and production of multiple shoots from different explants of Citrullus colocynthis (L.) Schrad. Gamma radiations (5 kR to 20 kR) and certain chemicals have been effected on plant growth developments and changes of biochemical metabolisms in plants. Murashige and Skoog (MS) medium containing with auxins such as NAA, IAA, 2,4-D (0.5 ~ 2.0 mg/l), cytokinines BAP, kn TDZ, (0.5 ~ 2.5 mg/l), L-Glutamic acid (1 ~ 2 mg/l) and Coconut milk (10 ~ 20%). After 5 weeks on induction media, explants and callus (EC) were exposed to 5 kR, 10 kR, 15 kR and 20kR, of gamma radiation and treated with 1, 2, 3, 4 and 5 mM ethyl methane sulphonate (EMS) for 30 min. The highest percentage of callusing was observed (70%) stem irradiated with 5 kR and significantly decrease in fresh and dry weight of callus in the below 4 kR doses and above 20 kR doses, there was a progressive decrease in the fresh weight and dry weights when compared to control callus. Maximum percentage of plantlet regeneration (59%) was induced from callus exposed to 15 kR gamma irradiation on MS media fortified with 2.0 mg/l 2,4-D + 2.0 mg/l BAP + 2.0 mg/l L-glutamic acid. Increase in gamma irradiation dose above 15 kR and 5 mM EMS reduced regeneration capacity of callus. Doses higher than 20 kR and 7 mM EMS was lethal to micropropagated plants of Citurullus colocynthis.

• 한국자기학회지
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• 제11권2호
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• pp.58-62
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• 2001

L $i_{0.5}$ F $e_{2.5-x}$A $l_{x}$ $O_4$ 페라이트계에 대한 XRD와 Mossbauer 스펙트럼을 측정 분석하였다. $Al^{3+}$ 씨온의 치환량 x가 증가할수록 격자상수는 작아지고, 값이 0, 0.3, 0.6인 시료에서는 두 site의 F $e^{3+}$ 이온에 의한 두 개의 6선 흡수선이 나타났고, x가 0.9, 1.2인 시료에서는 6선 흡수선외에 열에 의한 전자적 완화현상에 기인한 2선 흡수선이 공존하였으며, x가 1.5인 시료는 2선 흡수선만 나타났다. 공명흡수면적으로 계산된 L $i_{0.5}$ F $e_{2.5-x}$A $l_{x}$ $O_4$ 페라이트계의 금속 양이온 분포식은(L $i_{1-a}$$^{+}$F $e_{a}$ $^{3+}$ ) z으로 나타낼 수 있었고, 시료내의 $Al^{3+}$ 의 증가는 B-site의 F $e^{3+}$ - $O^{2-}$ 결합거리를 증가시켜 공유 결합성을 약화시키는 것으로 확인되었으며, $Al^{3+}$ 씨 증가에 따라 B-site의 F $e^{3+}$ 이온의 수가 감소하여 A-B 초 교환 상호 작용이 약화되는 것을 알 수 있었다.다.

• Journal of Advanced Marine Engineering and Technology
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• 제21권4호
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• pp.430-436
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• 1997

Time-dependent Flow characteristics of a two-dimensional lid-driven square cavity flow of six high Reynolds numbers, $10^4 2{\times}lO^4., 3{\times}l0^4, 5{\times}lO^4, 7.5{\times}lO^4$ and $10^5$ were investigated. A convection conservative difference scheme based upon SOLA to maintain the nearly 2nd-order spatial accuracy was adopted on irregular grid formation. Irregular grid number is $80{\times}80$ and its minimum size is about 1/400 of the cavity height(H) and its maximum is about 1/53 H. The result shows that at Re= $10^4$, periodic migration of small eddies appearing in corner separation region and its temporal sinusoidal fluctuation are represented. And another critical Reynolds number which shows the commencement of flow randomness emerging from the periodic fluctuation is assumed to be around Re= $1.5{\times}10$. At five higher Reynolds numbers ($2{\times}lO^4., 3{\times}l0^4, 5{\times}lO^4, 7.5{\times}lO^4$ and $10^5$), an organizing structure of four consecutive vortices similar to a Moffat vortex at two lower corners is revealed from time-mean flow patterns.

• Journal of Plant Biotechnology
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• 제39권4호
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• pp.288-294
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• 2012

본 연구는 '황금배'('Whangkeumbae')의 엽 절편체로부터 형질전환 체계 확립을 위한 효율적인 재분화 체계 확립을 위해 식물 생장조절제와 주요 탄소원인 sucrose, sorbitol이 식물체 재분화에 미치는 영향을 조사하기 위해 수행되었다. 잎 절편체를 MS 배지에 TDZ 농도를 각각 0.1, 0.25, 0.5, 1, 2.5, 5 mg/L으로 하여 IBA 0.3 mg/L을 혼용 처리한 결과 TDZ 0.25 mg/L 농도에서 61.1%의 가장 양호한 재분화율을 보였으며 TDZ 2.5 mg/L 이상의 농도에서는 신초의 재분화율이 급격히 감소하였다. IBA와 IAA 농도에 의한 신초의 재분화율은 TDZ 0.5 mg/L와 IAA 혼용 처리한 구에서 전체적으로 높은 신초의 재분화율을 보였으며 특히 TDZ 0.5 mg/L + IAA 0.3 mg/L 처리구에서 76.7%의 가장 높은 재분화율을 보였다. 서로 다른 탄소원으로써 sucrose와 sorbitol의 영향에 대하여 15 g/L, 30 g/L 농도로 처리한 결과 sorbitol 30 mg/L에서 가장 높은 재분화율을 보였고 또한 절편체 당 신초의 수도 3.5개로 가장 양호하였다. 따라서 sorbitol이 sucrose보다 '황금배'의 신초의 재분화에 있어서 효과적이었다.

• Bulletin of the Korean Chemical Society
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• 제23권12호
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• pp.1719-1723
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• 2002

1,5-diphenylcarbazone was immobilized on sodium dodecyl sulfate coated alumina. The alumina particle was effectively used for collection of mercury(II) and methylmercury cations at sub-ppb level. The adsorbed mercury was eluted with l mol $L^{-1}$ of hydrobromic acid solution. The mercury(II) was then directly measured by cold vapor atomic absorption spectrometry utilizing tin (II) chloride where as the total mercury was determined after the oxidation of methylmercury into the inorganic mercury. The methylmercury concentration was calculated by the difference between the value of total mercury and mercury (II). Mercury (II) and methylmercury cations were completely recovered from water with a preconcentration factor of 100 (for 1 L solution.) Relative standard deviation at Hg L ${\mu}gL^{-1}$ level 1.7%(n=8) and the limit of detection was 0.11 ${\mu}gL^{-1}$. The procedure was applied to spring water, well water and seawater and accuracy was assessed through recovery experiments.

• KSBB Journal
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• 제17권2호
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• pp.169-175
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• 2002

원유로부터 다당류를 생산하는 유산균을 분리, 선발하여 균의 배양조건을 조사하고 Lactobacillus ssp. SCU-M으로 동정, 명명된 최적배지의 탄소원은 galactose 1.5% 첨가시 553 mg/L의 EPS를 생성하였으며 whey의 이용성 검토를 위한 deproteinized whey와 lactic acidified whey를 탄소원으로 사용하였을 때 각각 639, 550 mg/L를 생성하였다. 질소원으로 yeast extract 1.5%, peptone 0.5%를 첨가한 경우 934 mg/L, 미량성분으로 , 0.15% $K_2$HPO, 0.15% 첨가시 1,076 mg/L의 다당 생산성을 나타내었다. 따라서 이들 결과를 종합하여 galactose 1.50%, yeast extract 1.00%, peptone 0.25%, MgSO$_4$, 7$H_2O$ 0.15%, $K_2$HPO$_4$0.15%, tween 80, 0.10%를 적정 배지로 하여 PH 6.5, 배양온도 37$^{\circ}C$에서 배양시 1,680 mg/L의 EPS를 생성하였다.