• Title/Summary/Keyword: Breakdown experiment

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Experiment and Analysis of Mooring System for Floating Fish Cage (해상 양식시설의 계류시스템 실험 및 해석)

  • KIM Jin-Ha;KIM Hyeon-Ju;HONG Sup
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.34 no.6
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    • pp.661-665
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    • 2001
  • This paper deals with optimal mooring system to secure fish cage in a desired location, Through field investigation and paper works, we surveyed disasters by breakdown of cage frame and mooring system due to higher wave attack and selected compliant buoy mooring method for shallow water mooring system against severe coastal external forces. To analyze interaction between external forces and compliant buoy mooring system, theoretical model has developed as quasi-static nonlinear analysis. After verifying the feasibility of the numerical model compared with experiment, static analysis has tried for various mooring systems with different angle of array, number of mooring points, length of horizontal and inclined rope. Optimal mooring method using compliant buoy has selected for fish cage through numerical simulation. This results can apply for preliminary design for cage mooring system.

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Clinical Effect of the Subantimicrobial Dose of Doxycycline ( SDD ) on the Chronic Periodontitis (만성치주염 환자에 대한 저용량 독시싸이클린의 임상적 효과)

  • Kim, Yoon-Sik;Paik, Jeong-Won;Kim, Chang-Sung;Choi, Seong-Ho;Kim, Chong-Kwan
    • Journal of Periodontal and Implant Science
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    • v.32 no.2
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    • pp.415-428
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    • 2002
  • Periodontal disease is a complex infectious disease caused by bacteria in the oral mucosa, which results in gingival inflammation, breakdown of periodontal tissues, bone resorption, and finally tooth loss. Mechanical plaque control methods-scaling and root planing are effective methods to stop the progression of such periodontal disease. It was reported that subantimicrobial dose of doxycycline(SDD) regimen could improve clinical conditions of periodontal tissues without causing the overgrowth of opportunistic organisms that was a typical antibiotic side effect. Therefore pharmacological therapy, used in conjunction with mechanical therapy could be considered a useful treatment modality in the treatment of chronic periodontal disease. In this study, 30 patients diagnosed as moderate to advanced chronic periodontitis were divided into 2 groups. In this double-blind, placebo-controlled study, the patients were administered 20mg doxycycline capsule or placebo capsule b.i.d. for 4months, after scaling and root planing. Clinical parameters-bleeding on probing, pocket depth and clinical attachment level were compared and evaluated between these groups at periods of first visit, 1 month, 2 months, 3 months, 4 months. The results were as follows ; 1. In case of moderate periodontitis, pocket depth showed significant reduction after treatment in both the control & experiment groups, when compared with the baseline values(p<0.01), but in case of advanced periodontitis, only the experiment group showed significant reduction after treatment when compared with the baseline values(p<0.05). Statistically significant reduction in pocket depth was observed in the experiment group compared to the control group(p<0.05). 2. In case of moderate periodontitis, clinical attachment level showed significant reduction after treatment in both the control & experiment groups, when compared with the baseline values(p<0.01), but in case of advanced periodontitis, only the experiment group showed significant reduction after treatment when compared with the baseline values(p<0.05). Statistically significant reduction in clinical attachment level was observed in the experiment group compared to the control group(p<0.05). 3. Bleeding on probing improved after treatment in both the groups. In case of moderate periodontitis, the experiment group showed statistically significant reduction of bleeding on probing when compared with the control group at 1 and 4 months after treatment(p<0.05). In case of advanced periodontitis, treatment resulted in statistically significant reduction of bleeding on probing in both the groups(p<0.05). These results indicate that the use of subantimicrobial dose of doxycycline is a useful supplement to mechanical treatment for periodontal patients in ameliorating the clinical parameters such as periodontal pocket, attachment level, and bleeding on probing.

Changes in Physicochemical Properties of Rice Grain during Long-Term Storage (장기저장한 벼 종실의 이화학적 특성 변화)

  • Lee, In-Keun;Kim, Kwang-Ho;Choi, Hae-Chune
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.38 no.6
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    • pp.524-530
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    • 1993
  • The experiment was carried out to investigate the changes in physicochemical properties of milled rice harvested in different year and stored for four to sixty four months. The fat acidity of milled rice increased sharply from four to sixteen months storage, and after then it was increased slowly to sixty four months. Amylose, magnesium, potassium content, and K/Mg ratio of milled rice were not changed by storage duration. Water absorption rates of milled rice at 21$^{\circ}C$ and 77$^{\circ}C$, and alkali digestion value were increased by longer storage duration. Difference of water absorption rate between rice samples was greater during initial forty minutes after soaking at 21$^{\circ}C$ and with longer the soaking time at 77$^{\circ}C$. Shorter gel length of rice flour was found with prolonged storage duration, while peak, minimum, cool, breakdown and setback viscosity of gelatinized rice flour on amylograph were increased along with increasing the storage duration. The volume expansion rate during cooking and degree of iodine coloration of cooking water were higher in the longer stored rice compared with shorter one, and the amount of soluble solid in cooking water was significantly decreased in rice stored longer period.

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Comparison of Yield Performance and Grain Properties of North Korean Rices between Alpine and Lowland Area in Southern Part of Korea (북한 벼 품종의 평야지와 고랭지간 수량 및 미질 특성 비교)

  • Kim, Young-Doo;Noh, Tae-Hwan;Lee, Jae-Kil;Yang, Bo-Gab;Lee, Seon-Yong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.41 no.5
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    • pp.578-585
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    • 1996
  • This experiment was carried out to obtain the basic informations on yield performance and physicochemical quality properties of North Korean rices at southern high altitude area, Unbong and southeren plain area, Iksan. North Korean cultivars showed significant difference in number of spikelets per panicle, percentage of ripened grain and yield between two locations, but not significant in number of panicle per hill and l000-grain weight. The highest contribution to grain yield was the percentage of ripened grain and l000-grain weight at Iksan and Unbong, respectively, The protein, amylose content, alkali digestion value and Mg/K ratio showed larger variation in varieties than that in the locations cultivated. Mg and K revealed highly significant variations in locations, varieties and variety $\times$ location (V$\times$L) interaction. The amylogram characteristics such as initial pasting temperature, peak, breakdown, setback and consistency viscosities showed highly significant variation in locations, varieties and V$\times$L interaction. The physical characteristics of cooked rice such as adhesiveness, gumniness and chewiness also showed highly significant variations in locations, varieties and V$\times$L interaction.

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Varietal and Locational Variation of Grain Quality Components of Rice Produced in Hilly and High Altitude Areas in Korea (중산간지와 고냉지산 쌀 형태 및 이화학적특성의 품종 및 산지간 변이)

  • Choi, Hae-Chune;Chi, Jeong-Hyun;Lee, Chong-Seob;Kim, Young-Bae;Cho, Soo-Yeon
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.39 no.1
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    • pp.27-37
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    • 1994
  • To catch the relative importance of varietal and environmental variation in various grain quality components associated with palatability of cooked rice, grain appearance, milling recovery, several physicochemical properties of milled rice and texture or eating quality of cooked rice for rice materials of five japonica cultivars, produced at four locations of the mid-mountainous and alpine area of Korea in 1989, were evaluated and analyzed the obtained data. Highly significant varietal and locational variations were detected in 1000-grain weight, amylose content, K/Mg ratio, gelatinization temperature, peak viscosity, breakdown and setback viscosities as compared with variety x location interaction variation. Also, marked locational variations were recongnized in milling recovery from rough to brwon rice, alkali digestibility and protein content, and significant varietal variation was caught in stickiness /hardness ratio of cooked rice. The variety x location interaction variation was especially large in quality components of grain appearance and ripening, palatability of cooked rice and consistency viscosity. One thousand kernel weight was heaviest in Jinbuolbyeo and Odaebyeo, and the unfilled grain ratio was lowest in Jinbuolbyeo. Odaebyeo showed slightly' lower ratio of intact and clear milled rice because of more chalky rice kernels compared with other cultivars. Amylose content of Jinbuolbyeo and Sobaegbyeo was about 1% lower than that of others and K/Mg ratio of Odaebyeo was the lowest one among rice materials. Odaebyeo, Sobaegbyeo and Jinbuolbyeo revealed significantly low gelatinization temperature and setback viscosity while high peak and breakdown viscosities. Cholwon rice showed the greatest kernel weight, good grain filling but lowest ratio of intact and clear milled rice while Jinbu rices exhibited the highest milling recovery from rough to brown rice and ratio of sound milled rice. Amylose content of milled rice in Jinbu rices was about 2-3% lower than those in other locations. Protein content of polished rice was about 1% lower in rice materials of middle zone than those of southern part of Korea. K/Mg ratio of milled rice was highest in Jinbu rice and potassium content was slightly higher in the rice materials of middle region than in those of southern region. Alkali digestion value and gelatinization temperature of polished rice was markedly high in Jinbu rices as compared with other locations. Breakdown viscosity was hightest in Chlown rices and next higher with the order of Hwaso>Unbong>Jinbu rices, and setback viscosity was the quite contrary tendency with breakdown. The stickiness /hardness ratio of cooked rice was relatively higher value in Cholwon rices than in the others and the palatability of cooked rice was a little better in Unbong and Cholwon rices than in Jinbu and Hwaso rices, although variety x location interaction variation was large. The rice materials can be classified largely into two groups of Jinbu and the others by the distribution on the plane of 1st and 2nd principal components (about 60% of total informations) contracted from twelve grain quality properties closely associated with eating quality of cooked rice. Also, Jinbu and the other rices were divided into two and three rice groups respectively. Varietal variation of overall rice quality was smallest in Hwaso. The most superior rice group in overall quality evaluation included Odaebyeo produced at Cholwon, Unbong and Hwaso, and Sobaegbyeo grown at Unbong

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Influence of Low Temperature at Reproductive Stage on Rice Grain Quality (생식생장기 저온이 미질에 미치는 영향)

  • Jeong, Eung-Gi;Choi, Hae-Chune;Hong, Ha-Cheol;Moon, Huhn-Pal;Shin, Young-Beom
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.42 no.6
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    • pp.805-809
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    • 1997
  • The influence of cool temperature occurred during the booting stage in 1993 on quality of rice grain was compared with that in favorable weather of 1994. The mean and minimum air temperatures during the reproductive growth stage at the paddy field of Jinbu Substation, National Crop Experiment Station were 2.2~7.4$^{\circ}C$ and 2.0~8.9$^{\circ}C$ lower respectively in 1993 compared to those of 1994. Grain fertility and brown rice yield were 11.8% and 0.4t /ha, and 84.3% and 5.5t /ha in 1993 and 1994, respectively. There was no difference in amylose content between two years. However, protein content of brown rice in 1994 were 1.6% lower than that of 1993. There was no difference in alkali digestion value of milled rice between two years. Gel consistency of rice flour was 45mm in 1993 and 59mm in 1994. Amylogram characteristics of rice flour produced in 1993 showed lower peak hot, cool, and breakdown viscosities, and higher consistency and setback viscosities. The palatability of cooked rice by sensory panel test was considerably better in 1994 rice than in the rice of cool year.

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Cold Cathode using Avalanche Phenomenon at the Inversion Layer (반전층에서의 애벌런치 현상을 이용한 냉음극)

  • Lee, Jung-Yong
    • Journal of the Korean Vacuum Society
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    • v.16 no.6
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    • pp.414-423
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    • 2007
  • Field Emission Display(FED) has significant advantages over existing display technologies, particularly in the area of small and high quality display. In order to test the feasibility of fabricating the System-on-Chip(SOC) with FED, we conducted the experiment to use the p-n junction as an electron beam source for the flat panel display. A novel structure was constructed to form p-n junctions by generating inversion layer with the electric field from the cantilever style gate. When we applied more than 220V at the cantilever style gate which has a height of $1{\mu}m$, avalanche breakdown onset was successfully achieved. The characteristics was compared with the electron emission from the ultra shallow junction in the avalanche region. The experiment result and the future direction were discussed.

Study on waxy corn hybrids - XVI. Analysis of protein and amylogram on waxy corn (Zea mays L.) hybrids (찰옥수수 교잡종 연구 - XVI. 찰옥수수 교잡종에 대한 단백질 및 아밀로그램 분석)

  • Choi, Hyun-Gu;Lee, Moon-Sub;Bok, Tae-Gyu;Na, Woong-Hyun;Ko, Hyuck-Soo;Lee, Jong-Hyun;Yoo, Ji-Hong;Ju, Jung-Il;Jo, Yang-Hee;Lee, Hee-Bong
    • Korean Journal of Agricultural Science
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    • v.39 no.2
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    • pp.161-168
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    • 2012
  • Protein content of waxy corn hybrids ranged from 9.3 to 17.1%, and amylopectin content ranged from 83.9 to 94.5%. Three waxy corn hybrids including CNU043 showed less than 10 percent in protein content, and seven waxy corn hybrids including CNU052 were higher than 94% at the amylopectin content. At the amylogram test the ranges of the pasting temperature, peak viscosity, hot viscosity, cool viscosity, breakdown, setback, and consistency were 71.6~$77.5^{\circ}C$, 58~210 RVU, 36.1~114.2 RVU, 47~145 RVU, 21.4~97.8 RVU, -66.4~-9.6 RVU, and 11.1~36.3 RVU, respectively.

Characteristics of A New Flue-cured Tobacco Mutant Line KF 8832-85 (황색종 연초 돌연변이 계통 KF8832-85의 특성)

  • 조수헌
    • Journal of the Korean Society of Tobacco Science
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    • v.17 no.1
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    • pp.27-32
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    • 1995
  • A new flue-cured tobacco mutant line BU 8832-85 was developed at Taegu Experiment Station, Korea Ginseng and Tobacco Research Institute in 1994. KF 8832-85 was resulted from a cross of flue-cured cultivars NC 95$\times$NC 2326, and developed by a pedigree system of breeding ; initial selection was made by plant type and resistance to bacterial wilt(BW) disease(heudomonas solanaceamm) in the F2 generation under the natural field conditions infested with the pathogen. One white flowered plant was occurred by spontaneous mutation in a certain line among the F3 generatioin while the others were pink. Six plants from the seeds by selfing were selected at the field infested with the pathogen among 240 populations with white flowering in the F4, KF 8832-85 was selected based on yield and leaf quality trials among 6 lines in Fs generation. BCF 8832-85 was compared with its Parent for certain agronomic and chemical characteristics at Taegu Experiment Station in 1993 and 1994. The results showed that KF 8832-85 have white flower, the stalk height was approximately that of NC 2326 but averaged about loom taller than NC 95. It produced ground suckers as much as NC 95, and did not breakdown leaf at the same as WC 2326. KF 8832-85 have high resistance to bacterial wilt disease. Yield of KF 8832-85 was 10 and 18% higher then that of NC 2326 and WC 95, respectively. Price per Kg was equal to that of NC 2326. The contents of nicotine and reducing sugar did not differ significantly from NC 95, while total nitrogen was significantly lower than NC 95. Therefore, the new mutant line is genetically stable for agronomic and chemical characteristics and provides a source of bacterial wilt disease resistance for use in breeding resistant flue-cured cultivars. Key words : Mutant line, White flower, Spontaneous mutation.

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The Characteristics of Current Distribution and Electrical Insulation on High-Tc Superconducting Cable (고온 초전도 케이블의 전류 분포 및 전기절연 특성)

  • ;;;;Takataro Hamajima
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.52 no.6
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    • pp.271-277
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    • 2003
  • It is important to control layer current distributions of coaxial multi-layer HTS cables, because a homogeneous layer current distribution decreases AC loss and can supply the largest operational current. We have extended the theory that treat the operational current more than the critical current by considering V-I nonlinear characteristics of HTS tapes including flux flow resistance and contacting resistance between the cable and terminals. It is important to investigate the current distribution under the condition of operational current more than the critical current of cable, because the cable has experiences of fault current. In order to verify the extended theory, we have fabricated a two layers cable with the same twisting layer pitch. It was observed that almost all the operational current less than the critical current flowed on the outer layer because of its lower inductance. In case of operational current more than critical currents of layers, the flux flow resistances affect strongly current waveform and thereby the currents of layers were determined by the flux flow resistances. And we investigated breakdown characteristics in $LN_{2}$/paper composite insulation system for the application to a HTS cable. In this experiment, we got some information out of that the electrical characteristics of the insulation materials depends on the condition of butt gap.