• Title/Summary/Keyword: dark spot

검색결과 123건 처리시간 0.027초

SUNSPOT MODELING AND SCALING LAWS

  • SKUMANICH A.
    • 천문학회지
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    • 제36권spc1호
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    • pp.1-5
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    • 2003
  • In an early paper Skumanich suggested the existence of a scaling law relating the mean sunspot magnetic field with the square-root of the photospheric pressure. This was derived from an analysis of a variety of theoretical spot models including those by Yun (1968). These were based on the Schliiter-Temesvary (S- T) similarity assumption. To answer criticisms that such modeling may have unphysical (non-axial maxima) solutions, the S-T model was revisited, Moon et al. (1998), with an improved vector potential function. We consider here the consequences of this work for the scaling relation. We show that by dimensionalizing the lateral force balance equation for the S- T model one finds that a single parameter enters as a characteristic value of the solution. This parameter yields Skumanich's scaling directly. Using an observed universal flux-radius relation for dark solar magnetic features (spots and pores) for comparison, we find good to fair agreement with Yun's characteristic value, however the Moon et al. values deviate significantly.

ZnS:Cu 형광체의 전계 발광 및 가속열화 특성 (Electroluminescent and Accelerated Aging Properties of ZnS:Cu Phosphor)

  • 이종찬;황명근;박대희
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2001년도 학술대회논문집
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    • pp.13-16
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    • 2001
  • In this paper, the emission and aging properties of ZnS:Cu electroluminescent device were experiment respectively at room temperature and 7$0^{\circ}C$ relative humidity 100%. ZnS:Cu and BaTiO$_3$were respectively used for phosphor and dielectric. While AC 100V on 400Hz frequency were applied to the devices at room temperature and 70$_3$relative humidity 100%, the change of brightness were measured and compared. The surface of aged devices were investigated by scanning electron microscope. With the continuously operated environment of room temperature and 7$0^{\circ}C$ relative humidity 100%, the decay time were measured and the dark spot and aging status on the surface of the device were investigated. ZnS:Cu electroluminescent properties were deteriorated by the Increased temperature and humidity. Also the deteriorated properties were confirmed by the brightness and surface chanties of device, and the aging mechanism from the simulation on sulfur vacancy and deep tracts density.

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Bacillus sp. PY123 균주가 생성하는 수용성 황색수소의 부분 정제 및 그 안정성 (Partial Purification and Stability of a Water-soluble Yellow Pigment from Bacillus sp. PY123.)

  • 김지연;김광현;김병우;이광배
    • 환경위생공학
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    • 제14권4호
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    • pp.35-40
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    • 1999
  • For application of a yellow pigment as food additives, stability of a water-soluble yellow pigment from Bacillus sp. PY123 was investigated. The yellow pigment from Bacillus sp. PY123 was purified with pH treatment, activated carbon and silica gel column chromatography. The partial purified yellow pigment appeared only one spot on silica gel TLC after 12 evaporation and under irradiation of UV 253nm at dark room. Rf value of the pigment was measured at 0.04 and 0.12 with development of a solvent mixture (Butanol : Acetic acid : water = 4 :1:5) and a solvent mixture (Isopropanol : Ammonia : Water = 9 :1: 2), respectively, The partial purified pigment appeared a white fluorescence under UV365nm irradiation. The partial purified yellow pigment had a main peak and a minor peak on HPLC using 20mM phosphate buffer(pH 7.0) at 1ml/min flow rate. The partial purified pigment was stable at heat treatment, acidic pH, oxide-reductants and surfactants.

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First Report of Foliar Blight on Dendropanax morbifera Caused by Alternaria panax

  • Deng, Jian Xin;Kim, Chang-Sun;Oh, Eun-Sung;Yu, Seung-Hun
    • Mycobiology
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    • 제38권4호
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    • pp.316-320
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    • 2010
  • Leaf spot and blight disease was observed on two-year-old seedlings of Dendropanax morbifera (Korean name: Hwangchil tree) during July of 2008 in Jindo Island, Korea. Symptoms included yellow-brown to dark brown irregularly enlarged spots frequently located along the veins of leaves. The lesions were often surrounded by chlorotic haloes. Severe leaf blight and subsequent defoliation occurred when conditions favored disease outbreak. The causal organism of the disease was identified as Alternaria panax based on morphological characteristics and sequence analysis of the internal transcribed spacer region of rDNA. A. panax isolates induced leaf spots and blight symptoms not only on D. morbifera but also on the other members of Araliaceae tested. This is the first report of foliar blight caused by A. panax on D. morbifera.

제주도 동부연안에서 채집된 청베도라치과 (농어목) 1미기록종, Istiblennius dussumieri (New Korean Record of the Streaky Rockskipper, Istiblennius dussumieri (Perciformes: Blenniidae))

  • 김병직;안정현
    • 한국어류학회지
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    • 제19권2호
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    • pp.160-163
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    • 2007
  • 제주 동부 연안 암반역 조간대 웅덩이에서 청베도라치과에 속하는 Istiblennius dussumieri 6개체(표준체장 27.9~46.6 mm)를 채집하였다. 본 종은 한국미기록종으로 '검은점베도라치'라 명명하였으며, 형태적 특징을 상세히 기재하였다. 제주도 동부 연안역은 인도-태평양해역에서 검은점 베도라치의 새로운 최북단기록이며, 쓰시마난류에 편승한 난 자치어 수송에 의한 일시적인 출현으로 사료된다.

KrF 엑시머 레이저에 의한 ITO 박막의 어블레이션과 표면특성관찰 (The ablation of ITO thin films by KrF Eximer laser and its characteristics)

  • Lee, Kyoung-Cheol;Lee, Cheon
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 추계학술대회 논문집
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    • pp.511-514
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    • 2000
  • This work aimed to develop ITO (Indium Tin Oxide) thin films ablation with a KrF Eximer laser required for the application in flat panel display, especially patterning into small geometry on a large substrate area. The threshold fluence for ablating ITO on glass substrate is about 0.1 J/cm$^2$. And its value is much smaller than using third harmonic Nd:YAG laser. Through the optical microscope measurement the surface color of the damaged ITO is changed into dark brown and irradiated spot is completely isolated form the undamaged surroundings by laser light. The XPS analysis showed that the relative surface concentration of Sn and In were essentially unchanged (In :Sn=5:1) after irradiating Eximer laser. Using aluminium mask made by second harmonic Nd:YAG laser the ITO patterning is carried out.

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Identification and Characterization of Pseudocercospora cornicola Causing Leaf Spots on Cornus officinalis

  • In-Young Choi;Ho-Jong Ju;Lamiya Abasova;Joon-Ho Choi;Hyeon-Dong Shin
    • 한국균학회지
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    • 제50권2호
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    • pp.131-136
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    • 2022
  • Cornus officinalis plants that grow in several locations in Korea have been found to be infected with leaf spot disease. Symptoms include necrotic lesions, which are angular, irregularly shaped, vein-limited, and dark brown, on both sides of the leaves. The causal agent of the disease was identified to be Pseudocercospora cornicola based on the morphological characteristics of the fungus and molecular phylogenetic analysis of the obtained multi-locus DNA sequence data. This is the first report investigating P. cornicola found on C. officinalis in Korea.

Botrytis fabae에 의한 잠두 붉은점무늬병 (Red Spot of Broad Bean (Vicia faba) Caused by Botrytis fabae)

  • 권진혁;강수웅;김정수;박창석
    • 식물병연구
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    • 제8권1호
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    • pp.63-65
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    • 2002
  • 2001년 경상남도 남해군 창선면 잠두 재배포장에서 잎과 줄기에 붉은점무의 병이 심하게 발생하였다. 이 병의 병징은 잎에 원형의 붉은점무늬가 많이 생기고 병반의 크기는 1~4.2mm이며, 줄기에는 가늘고 긴 방추형 모양의 병반이 생기고 크기는 1~l5mm이었다. 포장에서 발생율은 16.4~84.6%이 었다. 분생포자와 분생포자병은 PDA배지 상에서 잘 형성되지 않았으나, PDA배지에 잠두 잎 추출액을 첨가하였을 때는 보다 양호하게 형성되었다. 분생포자는 원형 또는 난형이며 담황록색고 크기는 10~24$\times$8~22 $\mu$m 이었다. 분생포자병은 원통형, 담갈색이고 크기는 3.6~12.8 $\mu$m이었다. 균사생육은 적온은 2$0^{\circ}C$에서 균핵 형성은 15$^{\circ}C$-2$0^{\circ}C$에서 가장 잘 형성하였고, 검은색이고 구형 또는 부정형이며, 균핵의 크기는 1.2-11.8mm였다. 병원균의 균학적 특징과 병원성을 검정한 결과 이 병을 Botrytis fabae에 의한 잠두 붉은점무늬병으로 명명하고자 제안한다.

Stemphylium lycopersici에 의한 고려엉겅퀴 점무늬병의 발생 (Occurrence of Leaf Spot Caused by Stemphylium lycopersici on Cirsium setidens in Korea)

  • 최효원;김석구;홍성기;이영기;이재금;김효원;이은형
    • 한국균학회지
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    • 제44권3호
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    • pp.201-205
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    • 2016
  • 2015년 8월경 강원도 영월군의 고려엉겅퀴 재배 농가에서 잎에 소형 점무늬 증상이 발생하였다. 초기에는 고려엉겅퀴 잎에 회갈색 내지 갈색의 작은 점이 나타나며, 병이 진전되면 부정형의 진한 갈색의 병반으로 커지면서 크게 확대되고 결국 잎 전체가 진한 갈색 내지 흑색으로 변하였다. 병든 잎에서 Stemphylium균이 분리되었으며, 분생포자 크기와 분생포자경의 길이 등을 고려한 균학적 특성에 의해 Stemphylium lycopersici 혹은 Stemphylium solani, Stemphylium xanthosomatis와 유사한 것으로 나타났다. Ribosomal internal transcribed spacer (ITS) 영역, elongation factor 1 alpha (EF-$1{\alpha}$), glyceraldehydes-3-phosphate dehydrogenase (gpd), vacuolar membrane ATPase catalytic subunit A gene (vmaA)와 vacuolar biogenesis gene (vpsA) 사이의 noncoding 영역을 대상으로 한 다자위 염기서열 분석에 의해 분리균은 모두 S. lycopersici로 확인되었다. 고려엉겅퀴 잎을 대상으로 상처구와 무상처구로 나누어 분리균의 포자 현탁액을 접종하여 병원성을 확인한 결과, 접종 3일 후부터 상처의 유무에 관계없이 분리균을 접종한 부위에서 병반이 관찰되었다. 따라서 본 결과를 토대로 본 병을 S. lycopersici에 의한 고려엉겅퀴 점무늬병으로 명명하며, 고려엉겅퀴 점무늬병의 발생을 국내 최초로 보고한다.

원형질체 내 Plasmid Electroporation에 의한 벼 배발생세포의 형질전환 1. 벼의 Electroporation 원형질체로부터 식물체 재분화 (Transformation of Rice Embryogenic Cells by Electroporation Mediated Plasmid Uptake into Protoplasts 1. Plant Regeneration from Electroporated Protoplasts of Rice)

  • 김명덕;최성진김준철
    • KSBB Journal
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    • 제10권1호
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    • pp.23-29
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    • 1995
  • 발아된 벼(Oryza sativa L. cv. Nakdong)의 하배 축에서 callus를 유도하고, 현탁배양한 세포에서 원 형질체를 분리하여 MS 배지에서 재분화를 수행하였다. Callus는 하배축으로부터 $2.5mg/{\ell}2$,4-0를 첨가한 LS 배지에서 최고 65%의 치상효율로 유도되었으며, 형태척으로 선별 가능한 embryogenic callus 는 $2mg/{\ell}2$,4-D, O.2mgj P kinetin과 $0.1mg/{\ell} GA_3$ 가 첨가된 AA, 배지에서 현탁배양하였다. 4개월 이상 현탁배양한 세포로부터 분리한 원형질체는 voltage를 400V jern와 Imsec 통안 electropora­tion했을 때 $2.5mg/{\ell}2$,4-D, $0.1mg/{\ell}$kinetin과 lOmM proline이 첨가된 PCM 배지에서 1.1%의 치 상효율을 보였다. 형성된 microcalli는 LS2.5 배지 에 치상된 feeder cell에 $0.2\mu\textrm{m}$membrane filter를 얹은 위에 옮겨 암소에서 2주 동안 배양한 후, $30{\pm}/3{\mu}E$.m^{-2}S^{-1}의 형광하에서 2주 통안 배양했을 때 2mm 직경의 노란색 callus를 형성하였다. 형성된 callus를 재분화 배지에 치상하였을 때, 녹점 green spot)에서 shoot 형성과정을 거쳐 완전한 식물체로 분화되었으며 재분화율은 1l~33%였다.

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