• Geomechanics and Engineering
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• 제24권4호
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• pp.337-348
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• 2021

Brillouin Optical Frequency Domain Analysis (BOFDA) is a distributed fiber optic sensing (DFOS) technique that has unique advantages for performance monitoring of piles. However, the complicated production process and harsh operating environment of offshore PHC pipe piles make it difficult to apply this method to pile load testing. In this study, sensing cables were successfully pre-installed into an offshore PHC pipe pile directly for the first time and the BOFDA technique was used for in-situ monitoring of the pile under axial load. High-resolution strain and internal force distributions along the pile were obtained by the BOFDA sensing system. A finite element analysis incorporating the Degradation and Hardening Hyperbolic Model (DHHM) was carried out to evaluate and predict the performance of the pile, which provides an improved insight into the offshore pile-soil interaction mechanism.

• 한국균학회지
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• 제51권2호
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• pp.141-146
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• 2023

Stem rot symptoms were observed in Gondre (Cirsium setidens) plants growing in a vinyl greenhouse in Taebaek, Korea during a disease survey in June 2022. The plants presented with dark brown to black rot on the stems at or above the soil line. Severely diseased plants displayed wilt and blight. Disease incidence among these plants ranged from 1 to 5%. Three isolates of Rhizoctonia sp. were obtained from the stem lesions of diseased plants. All isolates were identified as Rhizoctonia solani AG-2-2(IV) based on the morphological and cultural characteristics, results of the anastomosis test, and phylogenetic analysis. The pathogenicity of the isolates to Gondre plants was confirmed using an artificial inoculation test. The lesions induced by the inoculation test were similar to those observed in the investigated vinyl greenhouse. Here, we report a case of R. solani AG-2-2(IV) causing stem rot in Gondre.

• 한국균학회지
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• 제50권1호
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• pp.61-64
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• 2022

In July and September 2020, a severe outbreak of stem rot was observed on bonnet bellflower (Codonopsis lanceolata) plants in a farm located in Chuncheon, Gangwon Province, Korea. The symptoms initially appeared on the stem at or above the soil line. Later, the infected stem completely rotted and blighted. The incidence of diseased plants in the field was 2-30%. Ten isolates of Rhizoctonia sp. were obtained from the stem lesions of diseased plants. All isolates were identified as Rhizoctonia solani AG-4 based on the morphological characteristics and anastomosis test. Three isolates of R. solani AG-4 were tested for pathogenicity on bonnet bellflower plants through artificial inoculation. All tested isolates induced stem rot symptoms on the inoculated plants. The symptoms were similar to those observed in plants from the farm. This is the first report of R. solani AG-4 causing stem rot in bonnet bellflower.

• 한국균학회지
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• 제50권2호
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• pp.143-147
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• 2022

Sclerotinia rot symptoms were observed in stringy stonecrop (Sedum sarmentosum) plants growing in vinyl greenhouses in Yeoju and Icheon, Gyeonggi Province, Korea, during disease surveys in spring 2019 and 2020. The initial symptoms were soft rot on stems and leaves at or above the soil line. Furthermore, the symptoms progressed upwards, and the infected plant parts exhibited white to grayish-yellow discoloration. The infestation of diseased plants in the vinyl greenhouses was 1-5% at the two locations examined. Eight isolates of Sclerotinia sp. were obtained from lesions of the diseased plants. The isolates were identified as Sclerotinia sclerotiorum based on their morphological and molecular characteristics. In addition, artificial inoculation tested three isolates of S. sclerotiorum for pathogenicity on stringy stonecrop plants. All the tested isolates caused Sclerotinia rot symptoms in the inoculated plants. The symptoms were similar to those observed in plants from the vinyl greenhouses investigated. This study is the first report of S. sclerotiorum causing Sclerotinia rot in stringy stonecrop.

• 환경생물
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• 제41권3호
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• pp.215-222
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• 2023

In 2022, research for native prokaryotic species in Korea reported 10 unrecorded bacterial strains affiliated to phyla Actinomycetota, Bacillota, and Pseudomonadota. The strains formed monophyletic clades with the most closely related species (with ≥98.7% sequence similarity) in the 16S rRNA gene sequencing. Among them, four species of the phylum Actinomycetota, two species of the phylum Bacillota, and four species of the phylum Pseudomonadota have not been reported in Korea, suggesting unrecorded species in Korea. Information on strains such as Gram staining reaction, colony and cell morphology, biochemical characteristics, and isolation sources were provided in the species description.

• 한국균학회지
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• 제51권4호
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• pp.397-403
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• 2023

Wilt symptoms were observed in basil (Ocimum basilicum) plants grown in a vinyl greenhouse located in Gokseong, Korea, during crop disease surveys conducted in August 2022. The symptoms appeared as wilting of the plants and brown to dark brown longitudinal streaks on the stems at or above the soil line. The disease incidence among the plants in the vinyl greenhouse was 5-20%. Six isolates of Fusarium sp. were obtained from stem lesions and identified as Fusarium oxysporum species complex based on their morphological characteristics. Among the isolates, two were used for phylogenetic analysis and pathogenicity test. Phylogenetic analysis revealed that these isolates belonged to F. oxysporum. Pathogenicity of the isolates was confirmed through artificial inoculation test. The symptoms induced by the isolates were similar to those observed in basil plants in the investigated vinyl greenhouse. This is the first report of F. oxysporum causing Fusarium wilt in basil in Korea.

• 농약과학회지
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• 제8권1호
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• pp.38-45
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• 2004

Imidacloprid를 물과 물-토양계에 처리후 광에 노출시켜 광분해 특성을 조사하였다. 물중에서 imidacloprid는 극성화합물로 전환이 빠르게 이루어져서 약제 7일에는 수상대 유기상의 분포비가 80 : 20 이었으며, 이러한 경향은 조사 후 60일까지 지속되었다. 광에 의한 imidacloprid의 대사물인 imidacloprid urea는 노출 1 일차에 0.0112 mg/kg이 검출되었으며, 7일차에는 0.0391 mg/kg로 최고 농도에 도달한 후 감소하여 60일에는 검출되지 않았다. 물-토양계에서 imidacloprid의 농도는 약제처리 7일 후 평형상태에 도달하였으며, 극성화합물로 전환은 7 일간 지속되어 수상과 유기상간 분배비는 80 : 20로 전환되었다. 광에 의하여 imidacloprid의 농도는 약제처리 당일에는 1.6538 mg/kg, 1일에 0.8785 mg/kg으로 감소하여 15일에는 검출한 계 미만으로 검출되지 않았으나, 광분해산물인 imidacloprid urea는 약제 처리 3일에 최고 농도인 0.0259 mg/kg에 도달한 후 감소하였다. 물과 물-토양계에서 imidacloprid는 광에 의하여 분해되어 imidacloprid urea가 생성되는 분해경로를 확인하였다.

• Weed & Turfgrass Science
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• 제2권3호
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• pp.260-266
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• 2013

본 시험은 간척 후 나타나는 식생과 토양의 변화를 조사하기 위하여 2008년 체절 된 새만금 간척지에서 식생의 발생이 시작된 2010부터 2012년 사이에 식생과 기반 토양의 특성을 조사한 결과이다. 조사위치별 토양염농도는 첫 조사시 담수호 인근에서 22.3 dS $m^{-1}$이었고 안쪽 내륙 인접부는 3.44 dS $m^{-1}$ 이하였으나 3년 후에는 전체가 4.22 dS $m^{-1}$ 이하로 낮아졌다. 토양유기물함량은 3년차 조사에서 약간씩 증가하는 경향이었고, 위치에 따른 유기물함량은 육지쪽에 인접하고 갈대 등의 식생발생량이 많았던 지점에서 높았으며, 토양 pH는 전체적으로 감소되는 경향을 나타냈다. 식생군락의 변화 중 식생종수는 조사 첫해 지점당 평균 7.1종 $m^{-2}$ 이었으나 3년 후에는 10.6종 $m^{-2}$으로 증가하였고, 식생종수는 염생식물과 내염성식물이 혼생된 중간정도의 염농도를 나타낸 군락에서 많았다. 식생 수는 대부분의 조사지점에서 증가하였고, 조사지점별로는 해홍나물이 밀생한 solt pan(솔트팬) 특성을 나타내고 있는 지점에서 많았고, 식생유입 초기인 해수면 인근과 갈대 및 갈대와 자귀풀의 우점도가 높은 군락에서 적었다. 군락 건물중은 첫 조사시 식생량이 적었던 해변쪽에서 증가하였고, 갈대의 우점도가 높았을 때 최대치를 나타냈다. 주요식생의 우점도는 토양염농도 감소의 영향을 받아 해홍나물, 퉁퉁마디, 갯꾸러미풀, 잔디는 크게 감소하였고 산조풀과 갈대는 증가하였다.

• Journal of Biosystems Engineering
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• 제42권2호
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• pp.104-111
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• 2017

Purpose: We have studied the necessary qualities of seedlings of some leafy vegetables for a riding-type two-row automatic transplanter. When seedlings are planted using a transplanter, long roots may be rounded in the bottom of the tray, and this can interfere with the separation of the seedlings. Uprightness related to leaf spread angle is an important quality for seedlings in mechanical planting. Methods: To select cultivars suitable for the transplanter, we compared varieties of Kimchi cabbage (Chukwang, Daetong, Whipalam and Namdo), head lettuce (Abi and Sensation), cabbage (YR Onnuri, YR Hogel, Harutama, and Ogane), and broccoli (Nicegreen and Earlyyou). To compare the effect of bed soil on root formation and growth, we used five types of soil: Chologi, Burger, Wonjomix, Bio, and Baroker with 2.6-3 L per tray. Growth increment and the degree of root formation were measured according to the RDA guidelines 25 days after sowing for Kimchi cabbage and head lettuce and 44 days after sowing for cabbage and broccoli. Conclusions: According to the plug tray, the optimum seedling age in both 128- and 200-hole trays was 28 days for Kimchi cabbage and 44 days for cabbage and broccoli. Head lettuce took 35 days in 128-hole trays and 31 days in 200-hole trays. Burger soil was most effective for root formation and growth of the four kinds of leafy vegetables; it appeared that smaller soil volume led to faster root formation.

• 대한환경공학회지
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• 제32권2호
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• pp.185-192
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• 2010

본 연구에서는 방해석을 주성분으로 하는 폐굴껍질을 고온에서 소성하여 생석회로 가공한 후 고농도의 납(전함량 29,000 mg/kg)으로 오염된 군부대내 사격장 토양에 처리하여 안정화 효율을 평가하였다. 소성 효과를 평가하고자 소성 전 폐굴껍질(NOS)과 소성 후 폐굴껍질(COS)을 각각 납 오염토양에 처리하였으며 28일간 습윤 양생한 후 0.1N HCl 추출에 의한 가용성 납 농도 변화를 관찰하였다. 실험결과 전 기간 동안 방해석을 주성분으로 하는 NOS에 비해 생석회가 주성분인 COS의 안정화 효율이 높게 나타났다. 또한 완전 습윤 상태 이상의 수분투여는 안정화 효율에 큰 영향을 미치지 않았으며, -#10 mesh에 비해 -#20 mesh의 입경에서 높은 안정화 효율을 나타내었다. NOS에 의한 안정화 처리 결과는 모든 처리에서 토양환경보전법상 '가'지역의 우려1기준 100 mg/kg (환경부 2009년 기준)을 만족 시키지 못 하였으나 COS 15% 및 20% 첨가 시 무처리구의 8,106 mg/kg에 비해 각각 47 mg/kg(28 days) 및 3 mg/kg(28 days)로 현격하게 저감되어 우려기준 100 mg/kg을 만족시켰다. 소성 굴껍질의 안정화 기작을 조사하고자 주사전자현미경(SEM)을 이용하여 elemental dot maps을 수행한 결과 Pb의 안정화는 Al 및 Si와 높은 상관관계가 있음을 확인할 수 있었다.