• 식물병연구
• /
• 제8권2호
• /
• pp.117-119
• /
• 2002

2002년 경상남도 남해군 창선면 잠두 재배포장에서 잎, 줄기, 꼬투리에 점무늬병이 심하게 발생하였다. 병징은 잎에 작은 둥근 점무늬가 나타나고 동심윤문을 형성하며 담갈색의 원형병반이 확대되면서 부정형으로 되고 괴사되면서 심할 경우 낙엽된다. 분생포자는 단생 또는 연쇄상으로 형성되며 모양은 긴타원형, 가늘고 긴 난형 또는 곤봉형으로 횡격막이 4~10개, 종격막이 1~2개가 있다. 색깔은 담황록색 또는 갈색이다. 크기는 25~61.3$\times$7.2~16.8$\mu\textrm{m}$ 이었다. 분생자병은 단생 또는 총생이며 담갈색이고, 크기는 18~113$\times$3~6 $\mu\textrm{m}$이었다. 균사생육 적온은 3$0^{\circ}C$이었다. 잠두 잎에 발생한 병징과 병원균의 균학적 특징을 검정한 결과, 이 병을 Alternaria tenuissima에 의한 잠두 점무늬병으로 명명하고자 제안한다.

• 식물병연구
• /
• 제19권1호
• /
• pp.55-59
• /
• 2013

이 연구는 국내에 보고되지 않은 로즈마리 점무늬병이 남원과 전주의 재배 온실에서 발생하여 구명하고자 실험하였다. 이 병은 주로 고온 다습한 시기인 장마끝 무렵에 발생이 많았다. 로즈마리의 잎과 줄기에 검은점무늬(직경 3-5 mm) 및 시들음 증상이 나타났다. 병든 조직을 습실 처리하면 분생자경과 분생포자가 형성되었다. 로즈마리 점무늬병균의 분생포자는 체인상의 가늘고 긴 원통형으로, 길이는 $55-275{\times}7-14{\mu}m$이었다. 분생포자는 분생자경 위에 형성되었고, 분생포자의 위격벽의 수는 8-10개이었다. 또한 생장적온은 감자한천 배지와 암흑조건에서 $30^{\circ}C$이었다. 포트 식물에 병원성 검정결과 분리한 병원균은 접종 3일 후에 잎과 줄기에서 자연 병징과 같은 점무늬 및 시들음 증상이 재현되었고, 병든 부위에서 동일한 균이 재 분리되었다. 따라서 병원성이 있음이 확인되었다. rDNA ITS 영역의 염기서열 분석결과 로즈마리에 점무늬병을 일으키는 병원균은 Corynespora cassiicola로 GenBank accession number JQ595296, JQ595297, FJ852715, AY238606와 염기서열이 100% 일치하였고, C. cassiicola와 같은 계통군에 속하였다. 따라서, 로즈마리 잎 및 가지 점무늬병균은 C. cassiicola로 보고하고자 한다.

• 한국어류학회지
• /
• 제27권1호
• /
• pp.39-44
• /
• 2015

우리나라 주변해역에서 채집된 둑중개과 가시꺽정이 14개체를 근거로 종 동정을 위해 외부 형태적 특징을 상세히 기재했다. 본 종은 제1등지느러미가 낮고 그 후방에 흑색 반점이 있는 점, 복부에 암색 반점이 없는 점, 제2등지느러미 후방에서 꼬리지느러미 기부에 이르는 등쪽 정중선을 따라 3개의 암색 안장 모양의 반문이 있는 점, 그리고 후두부에 2쌍의 피변이 있는 점에서 유사종인 '민가시꺽정이'와 쉽게 구별된다.

• 원예과학기술지
• /
• 제29권5호
• /
• pp.503-506
• /
• 2011

A new hybrid, Phalaenopsis 'Pink Marble' was made by the National Institute of Horticultural and Herbal Science, Rural Development Administration, in 2005. This hybrid was selected from self-crossed progenies of P. '21-1' (collected number) in 1999. In 2001, one line was selected based on the aspects such as flower color, leaf shape, flower stalk, and vigorous growth. Trials were conducted from 2003 to 2005 for evaluation and selection of this cultivar. 'Pink Marble' had a medium flowering habit and a dark pink spot (RHS, RPN74B) on white petal and sepal when fully opened. The number of flowers on each peduncle was 7.5, and flower diameter was 52.3 cm. The general impression of petals and sepals is a plate shape. The thick sepal could extend the long flowering time. The average length of leaf and peduncle were 16.5 cm and 6.8 cm, respectively. It had a half-erect leaf form, and was a fast-growing cultivar. This hybrid is relatively easy to clone.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
• /
• pp.3-4
• /
• 2008

Photovoltaic module consists of serially connected solar cell which has low voltage characteristics. But, the other way, the whole current flow of PV module is restricted by lowest current of one solar cell. For the experiment, we make PV module composing the solar cells that have short circuit current difference of 0%, 1%, 3% and 5%. Using Light I-V and Dark I-V measurements, electrical characteristic parameters like Isc(short-circuit current), Voc(open-circuit voltage), Rs(series resistance), Rsh(shunt resistance) are analyzed. PV module of low current characteristics has electrical stress from other modules. And, such a module has a tendency of hot-spot suffering which leads degradation.

• 한국표면공학회지
• /
• 제52권2호
• /
• pp.72-77
• /
• 2019

To study the characteristics of AC driven OLED, we fabricated the fluorescent OLEDs and analyzed the electroluminescence characteristics of OLEDs with AC negative voltage. The luminance and the current density of the OLED decreased, and the number and size of the dark spots increased in proportion to the duration time and level of the applied AC negative voltage. The current efficiency of the OLED was improved when high AC negative voltage was applied within a short time. When the AC negative voltage of 10 V was applied for 1 minute, the efficiency was improved by 12.4%. Also, the degradation of luminance and current efficiency due to the duration of light emission was improved in the case of OLED applied for 1 minute with 10 V AC negative voltage. These are expected as a result of the improvement of the leakage current characteristics by eliminating the short-circuit region formed by the defect of the OLED at the AC negative high voltage. As a result, the continuous application of AC negative voltage reduced the luminance and the current density of OLED, but the temporary application of AC negative voltage with the proper time and voltage could improve the efficiency and lifetime of OLED.

• Mycobiology
• /
• 제45권1호
• /
• pp.39-43
• /
• 2017

Leaf spot disease on black chokeberry (Aronia melanocarpa) was observed at several locations in Korea during 2014-2015. Leaf spots were distinct, scattered over the leaf surface and along the leaf border, subcircular to irregular and brown surrounded by a distinct dark color, and were expanded and coalesced into irregularly shaped lesions. Severely infected leaves became dry and fell off eventually. The causative agent was identified as Pseudocercospora pyricola. Morphological observations and phylogenetic analyses of multiple genes, including internal transcribed spacer, translation elongation factor 1-alpha, actin, and the large subunit ribosomal DNA were conducted. The pathogenicity test was conducted twice yielding similar results, fulfilling Koch's postulates. To our knowledge, this is the first report on P. pyricola infection of A. melanocarpa globally.

• The Plant Pathology Journal
• /
• 제20권2호
• /
• pp.85-91
• /
• 2004

A disease causing severe leaf spots in pepper plants has been observed in northern Gyeongbuk and Gangwon provinces in Korea since 1994. The current study diagnosed the disease as gray leaf spot caused by Stemphylium solani Weber and S. lycopersici (Enjoji) Yamamoto, both of which are pathogenic in pepper and tomato plants. Although the disease has been found in almost all areas where peppers are grown, it is more severe in mountain terrains where the nights are cool. Both species of pathogenic fungi were found to sporu-late profusely on V-8 juice agar in plastic or Pyrex glass Petri dishes, although not in domestically-produced glass Petri dishes, when cultured at $20^{\circ}C$ under irradi-ation from a daylight fluorescent lamp with a 12-hour light and dark alternation. The domestically-produced glass Petri dishes, which are made of window glass, were found to block near ultraviolet wavelengths, around and below 300 nm, which explained why the fungi did not sporulate. However, sporulation decreased at above $25^{\circ}C$ and most isolates failed to sporulate above $27^{\circ}C$. The worst level of disease was obtained when the inoculated plants were incubated with a $15^{\circ}C$ night and $20^{\circ}C$ day temperature regime relative to 4 night/day temperature combinations (15/20, 20/25, 25/30, and 30/35$^{\circ}C$).

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2007년도 추계학술대회 논문집
• /
• pp.432-432
• /
• 2007

We studied optical simulation method for ultra slim backlight system. We designed 0.7mm thickness light guide plate and combined 48 white color LEDs for 12 inch wide size TFT-LCD. We designed flat shape PMMA light guide plate with both side patterned. It have vertical prism shape on upper side and ellipse dot pattern on the other side. We targeted 4500 nit brightness and uniform emission characteristic without hot spot or dark area. At first, we designed uniform emission area with more high brightness in center area and then, debugged light entering hot spot zone and direction of outgoing light flux. Although it was designing step, we obtained good result with reverse prism optical sheet and it had good repeatability because it was based on the stamper method in injection process without laser engraving or micro groove engraving method.

• Journal of Forest and Environmental Science
• /
• 제37권4호
• /
• pp.338-340
• /
• 2021

Morus alba, known as White Mulberry, is one of the most common species of mulberry found in South Korea, along with M. australis, known as Korean Mulberry. During a routine survey to investigate fungal diseases on deciduous broad-leaved trees in 2020, leaf spots were consistently observed on the White Mulberry in Sejong-si (36°30'12.8"N 127°17'34.5"E) and Wonju-si (37°15'29.6"N 128°11'37.9"E), South Korea, with a disease incidence of approximately 70 to 80%. Symptoms included circular, tan or necrotic lesions surrounded by a dark margin on leaves, which, in some cases, the lesions coalesced to form relatively large necrotic regions. The pathogen was successfully isolated from M. alba, and was identified as Cladosporium pseudocladosporioides based on the phylogenetic analysis and morphology. To the best of our knowledge, this is the first report of leaf spot disease on M. alba caused by C. pseudocladosporioides in South Korea.