• Title/Summary/Keyword: L-6

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Broadband Coaxial-to-Double Ridge Waveguide Transformer Using L-shape Loop (L자형 루프를 이용한 광대역 동축-이중릿지도파관 변환기)

  • 김진형;김준태;박동철
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2001.11a
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    • pp.198-201
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    • 2001
  • L자형 루프를 이용하여 주파수대역이 6-18 GHz인 동축-이중릿지도파관 변환기를 상용 소프트웨어인 HFSS를 이용하여 설계한 후 제작하였다. L자형 루프는 동축-구형도파관 변환기에 이미 이용되고 있는 구조로써, 이를 동축-이중릿지도파관 변환기에 적용한 것이다. 제작 후 측정결과 대역폭이 6-18 GHz로 3:1 이상을 만족하며, 최대 삽입손실이 -1.52 dB 이었다.

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Study on Experimental Construction Monitoring for Revegetation on the Slope of an Expressway - Follow-up Study on the Experimental Area of Revegetation, the Slope of Dangjin Daejeon Expressway (Seosejong IC), Four Years after the Construction - (고속도로 비탈면 녹화 시험시공지 조사 연구 - 당진대전선 서세종 IC 비탈면 녹화 시험시공지에 대한 시공 4년 후 시점의 추적조사 -)

  • Jeon, Gi-Seong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.19 no.6
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    • pp.123-132
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    • 2016
  • The study was to introduce the revegetation measures for the improvement of the landscape in October, 2012 on the slope; two and four years after the introduction, the slope was examined to see the status of the revegetation. The result is as follows. The result from examining the soil on the slope, the soil was Loamy sand; which infers that the soil is in a poor condition for improving the scenery. Examining the characteristics of the vegetation-base materials, the soil acidity was pH 6.4 to 6.7; and the soil hardness was 21 to 24mm (hardness quotient of soil), this can be considered a favourable condition, which has no effect on the growth and development of plants. When it comes to the discovery of the species in the area, Lotus corniculatus var., Silene armeria L., Papaver rhoeas, Trifolium pratense L. developed and grew in spring after two years. And in the summer, Lotus corniculatus var., Dianthus chinensis L., Cosmos bipinnatus, Coreopsis drummondii L., Trifolium pratense were founded. And there were Lotus corniculatus var., Dianthus chinensis L., Aster yomena, Coreopsis tinctoria, Trifolium pratense L. in the autumn. According to the examination conducting after four years, Lotus corniculatus var., Dianthus chinensis L., Silene armeria, Cosmos bipinnatus, Coreopsis drummondii L., Papaver rhoeas, Trifolium pratense L. were founded in the spring, and Lotus corniculatus var., Dianthus chinensis L., Cosmos bipinnatus, Coreopsis drummondii L., Trifolium pratense grew in the summer. Lotus corniculatus var., Dianthus chinensis L., Astragalus sinicus, Aster yomena, Coreopsis tinctoria, Trifolium pratense L. were discovered in the autumn. Among the exotic species founded in the area, were Festuca arundinacea, Lolium perenne, Festuca rubra. When it comes to the protection of vegetation and dominance, Lotus corniculatus var., Metaplexis japonica, Coreopsis drummondii L. are the dominant species among the spring plants; and Lotus corniculatus var., Trifolium repens L., Erigeron annuus (L.) Pers. were the dominant plants in the summer. In the autumn, Lotus corniculatus var., Coreopsis drummondii L., Poa pratensis appear to be the dominant plants. The colonies of Pinus densiflora and Castanea crenata var. were formed around the South Sejong IC. Part of the area is occupied by the colony of Alnus hirsuta Turcz. ex Rupr. In terms of shrub, there were Indigofera pseudo-tinctoria, Robinia pseudoacacia, and Rosa polyantha var. genuina NAKA. As ground cover plants, Sasa borealis, Rubus crataegifolius Bunge were founded.

Selection and Physico-Chemical Characteristics of Lactic Acid Bacteria which had Cholesterol Lowering Activities (콜레스테롤 저하 유산균의 분리 및 이들 균주의 이화학적 특성)

  • Oh, Min-Keun;Rhee, Yong-Hwan;Choi, Ki-Chun;Lee, Yong-Kyu;Shin, Seung-Yee;Kim, Jong-Hyun
    • Applied Biological Chemistry
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    • v.42 no.2
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    • pp.83-90
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    • 1999
  • Four strains of lactic acid bacteria which had cholesterol lowering activities were selected from foreign fermented milk. The strains were identified as Lactobacillus(L.) rhamnosus 2084, L. casei 0781, Lactococcus (Lacto.) lactis spp. 204, and Enterococcus(E.) faecium 402. We observed that the L. rhamnosus 2084 was the most tolerant against pH 1.5, L. casei 0781 against pH 2.0, but not significantly different in the tolerance against pH 3.0. The L. rhamnosus 2084 was the most tolerant against bile acid and prominent in the degree of lowering cholesterol level. All four strains were used as starters in producing yogurt, and then investigated physico-chemical characteristics, such as pH, titratable acidity, and viable cell counts of yogurt base. L. casei 0781, L. rhamnosus 2084, Lacto. lactis 204, and E. faecium 402 were incubated for 6 hours at $40^{\circ}C$, 4 hours at $40^{\circ}C$, 6 hours at $37^{\circ}C$, and 12 hours at $37^{\circ}C$ and $40^{\circ}C$, respectively, for the optimum conditions of fermented milk.

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Plant Production from Desiccated Somatic Embryos of Acanthopanax chiisanensis (지리오가피 (Acanthopanax chiisanensis) 체세포배의 건조처리를 통한 식물체 증식)

  • Lee, Kang-Seop;Bang, Keuk-Soo;Choi, Yong-Eui;Ahn, Byung-Yong
    • Journal of Plant Biotechnology
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    • v.30 no.4
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    • pp.381-385
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    • 2003
  • An efficient method of plant regeneration from Acanthopanax chiisanensis somatic embryos was developed. Cotyledonary somatic embryos were obtained in liquid Murashige and Skoog (MS) medium from embryogenic cell suspension cultures. They were desiccated for 0 to 72 hr and then cultured on MS medium containing NAA, BA, GA$_3$, (0-0.5mg/L). The highest multiple shoots formation (100%) was obtained from 72 hr desiccated somatic embryos on ifs medium with 0.5mg/L NAA+0.5mg/L BA or 0.5 mg/L NAA+0.5mg/L BA+0.5mg/L GA$_3$ after 6 weeks culture. Plant conversion from multiple shoots was not high. The highest plant conversion from multiple shoots was obtained on 1/3MS medium with 1.0mg/L GA$_3$. Converted plantlets were transferred to ex vitro condition and the highest survival rate (70%) of the plantlets was obtained on plastic pots containing vermiculite and sand. These results indicate that micropropagation procedure can be applied for an efficient mass propagation of Acanthopanax chiisanensis.

A Study on the treatment efficiency of A2O Process coupled with Mesh Screening Reactor (Mesh Screening Reactor와 결합된 A2O 공정의 처리효율에 관한 연구)

  • Whang, Gye-Dae;Lim, Dong-Min
    • Journal of Korean Society of Water and Wastewater
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    • v.22 no.6
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    • pp.705-714
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    • 2008
  • Three Mesh Screenning Reactors (MSRs) were operated in three different modes to investigate the effect of the mesh opening size and the filtrate flux on the removal of particulate matters and the production of soluble organic matters. The mesh opening size was $82{\mu}m$ (Mode 1), $61{\mu}m$ (Mode 2) and $38{\mu}m$ (Mode 3), respectively, and each mode has three different filtrate flux; $0.47m^3/m^2/d$, $0.95m^3/m^2/d$ and $1.42m^3/m^2/d$, respectively. TSS removal efficiency of mode 1, 2, and 3 fed with 191 mgTSS/L was 27%, 36%, and 60%, respectively. The SCOD concentration of 91mg/L in influent for the mode 1, 2, and 3 increased to 117 mg/L, 127 mg/L, and 155 mg/L, respectively. For the all MSRs, there was no significant effect of filtrate flux on the removal of particulate matters and the production of soluble organic matters. However, the mesh opening size greatly affected the removal of particulate matters and the production of soluble organic matters in wastewater. Three parallel A2O processes consisting of anaerobic, anoxic and aerobic reactors maintaining mixed liquor suspended solids (MLSS) of 3,000 mg/L were operated to investigate the effectiveness of MSR on the removal efficiencies of the organic matters, nitrogen, and phosphorus; MSR influent was introduced to System 1 (183 mgTSS/L, 324 mgTCOD/L, 87 mgSCOD/L, 45.2 mgTKN/L, and 6.6 mgTP/L) and MSR efluent was introduced to System 2 and 3(72 mgTSS/L, 289 mgTCOD/L, 141 mgSCOD/L, 40.2 mgTKN/L, and 4.2 mgTP/L). HRTs of the anaerobic reactors in systems 1, 2 and 3 were 1 h, 1 h and 0.6 h, respectively and anoxic reactors were 2 h in all systems. HRTs of the aerobic reactors in systems 1, 2 and 3 were 5 h, 3 h and 3 h, respectively. TSS concentration in effluent of both system 2 and 3 is about 8 mg/L and lower than that of system 1 effluent. Despite higher TCOD loading and SCOD loading, both Systems 2 and 3 had a greater TCOD and SCOD removal efficiency at 91% and 92% than System 1 was at 88% and 82%, respectively. The nitrification efficiency for system 2 was greater than observed for System 1 (99% verses 97%). The denitrification efficiency for systems 1, 2 and 3 was 78%, 88% and 87%, respectively. System 2 and 3 showed about 12% higher TN removal efficiency than system 1 (85% verses 73%). The effluent TP concentration for system 2 was less than observed for system 1 and 3.

Bioconversion of nitrogen oxides and reduction of ferric ions by probiotic lactic acid bacteria (프로바이오틱스 유산균에 의한 질소 산화물 전환 및 철 이온 환원활성)

  • Kim, Selim;Hong, Jungil
    • Korean Journal of Food Science and Technology
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    • v.53 no.6
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    • pp.785-791
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    • 2021
  • Many lactic acid bacteria (LAB) have probiotic properties that exert various health benefits. In this study, the reduction potential of nitrogen oxide compounds and ferric ions by six LAB, including Lactobacillus kimchicus, L. lactis, L. casei, L. plantarum, L. rhamnosus GG, and Leuconostoc mesenteroides were evaluated. The L. kimchicus strain produced a substantial amount of nitrite reduced from nitrate added to the media, whereas the other five LAB strains did not. L. kimchicus also showed the most potent reducing activity of ferric to ferrous ions. However, the reduction potential of the autoclaved L. kimchicus was little pronounced. The scavenging activities of viable LAB or their cell lysates against different radicals were not consistent with the potency of the LAB's reducing ability. The present results indicate that L. kimchicus has a strong reduction potential for nitrogen oxides in viable status, and that this ability can be used as a probiotic property for various health benefits.

Optimization of the Medium and Fermentation Conditions with Erythritol Producing Moniliella suaveolens var. nigra (에리스리톨 생산 균주인 Moniliella suaveolens var. nigra를 이용한 배지 및 발효조건의 최적화)

  • Choe, Byeong-Uk;Park, Hong-U
    • KSBB Journal
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    • v.14 no.5
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    • pp.628-632
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    • 1999
  • Optimization of the medium and fermentation conditions for erythritol production has been studied. We have found that the optimal carbon source was glucose at the concentration of 400 g/L. The optimal temperature was 3$0^{\circ}C$ with excessive aeration. Improved erythritol productivity was achieved by reducing the yeast extract from 5 g/L to 3g/L while adding 2.7 g/L urea, 1.79g/L $K_2HPO_4, and 0.18g/L MgSO$_4$. 7$H_2O. The erythritol productivity increased from 0.747 g/L/h to 1.071 g/L/h and the yield increased from 31.4% to 45.2%. The byproduct glycerol was reduced from 96.6g/L to 45.7g/L as well. We have performed 5L fermentation with and without the pH control. The erythritol productivity with the pH control was about 30% lower than that without pH control. Excessive foaming of 5L fermentation has been observed during fermentation.

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Effects of Methionine Supplemented to Soy Milk on Growth and Acid Production by Lactic Acid Bacteria (두유(豆乳)에 첨가된 Methionine이 유산균의 생육과 산생성에 미치는 영향)

  • Ko, Young-Tae
    • Applied Biological Chemistry
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    • v.30 no.1
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    • pp.17-23
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    • 1987
  • Soy milk prepared from soy protein concentrate was fermented with each of the following lactic acid bacteria: Lactobacillus acidophilus KFCC 12731, L. acidophilus AKU 1122, L. bulgaricus, L. casei, Leuconostoc mesenteroides and Streptococcus lactis. The effects of methionine supple mented to soy milk on the growth and acid production by each organism. were investigated. L-methionine reduced the acid production by two strains of L. acidophilus while it had no apparent. effects on the other test cultures. The inhibitory effects of L-methionine on L. acidophilus KFCC 12731 was greater than on L. acidophilus AKU 1122. The acid production by L. acidophilus KFCC 12731 was also reduced substantially by DL-methionine supplemented to soy milk while it was not affected by D-methionine. Supplementation of L-cysteine to soy milk resulted in slight reduction of acid production by L. acido philus KFCC 12731.

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