• The Plant Pathology Journal
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• 제37권2호
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• pp.200-203
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• 2021

Rice blast caused by the filamentous fungus Magnaporthe oryzae, is arguably the most devastating rice disease worldwide. Development of a high-throughput and reliable field blast resistance evaluation system is essential for resistant germplasm screening, resistance genes identification and resistant varieties breeding. However, the occurrence of rice blast in paddy field is easily affected by various factors, particularly lack of sufficient inoculum, which always leads to the non-uniform occurrence and reduced disease severity. Here, we described a procedure for adequately inducing the occurrence of rice seedling blast in paddy field, which involves pretreatment of diseased straw, initiation of seedling blast for the first batch of spreader population, inducing the occurrence of the second batch of spreader population and test materials. This procedure enables uniform and consistent infection, which facilitates efficient and accurate assessment of seedling blast resistance for diverse rice materials.

• The Plant Pathology Journal
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• 제21권4호
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• pp.402-405
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• 2005

We have previously identified genes for four different protease inhibitors (PIs) that were induced upon rice blast infection in a rice blast resistant mutant SHM-11. Our expression analysis of the PIs indicated that induction of the PIs was the highest 24 hr after rice blast inoculation in the rice mutant SHM-11. Three PIs in the group of serine PIs were highly expressed while a cystein PI was weakly expressed upon rice blast inoculation. Four PIs were weakly induced 48 hr after pathogen inoculation in rice blast susceptible wild type rice plant. The simultaneous expression of three serine PIs was apparent from SHM-11 and two of them were induced in rice blast resistant Taebaegbyeo. One of them was induced in rice blast resistant Hwayeongbyeo while none of them were expressed in rice blast susceptible Nagdongbyeo and rice blast resistant Dongjinbyeo. Our results suggest that the expression of PI gene is rice cultivar specific and may be linked with the rice blast resistance in a specific rice mutant by the simultaneous expression of the PI genes.

• 한국자원식물학회지
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• 제27권6호
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• pp.687-700
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• 2014

Rice blast (Magnaporthe oryza B.) is one of the most important diseases in rice that causing great yield losses every year around the world. It is important to screen valuable genetic resources for improving blast resistance. This study was conducted to identify the blast resistance in 279 Korean rice landraces using blast nursery tests and isolate inoculum screening. The results showed that 11 landrace accessions found to be resistant to rice blast in blast nursery and inoculation screening tests and the degree of lesions in most accessions showed that they were susceptible to reactions. In order to find the distribution of blast resistant genes, a molecular survey was conducted to identify the presence of major blast resistance (R) gene in 279 Korean landraces. The results revealed that their frequency distribution was Pik-m (36.2%), Piz (25.4%), Pit (13.6%), and Pik (10%). Besides, the frequency distribution of Piz-t, Pii, Pik-m/Pik-p, Pi-39(t), Pib, Pi-d(t)2, Pita/Pita-2 and Pi-ta genes were identified as less than 10%. The results did not consist with the reactions against blast diseases between genotypes and phenotypic part of the nursery tests and isolate inoculation. For concluding these results, we used genome-wide SSR markers that have closely been located with resistance genes. The PCoA analysis showed that the landrace accessions formed largely two distinct groups according to their degree of blast resistance. By comparing genetic diversities using polymorphic information contents (PIC) value among the resistant, total and susceptible landraces, we found that PIC values decreased in four SSR markers and increased in six markers in the resistant accessions, which showed contrary to total and susceptible groups. These regions might be linked to resistance alleles. In this study, we evaluated the degree of blast resistance and the information about the distribution of rice blast resistant genes in Korean rice landraces. This study might be the basis for association analysis of blast resistance in rice.

• 식물병연구
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• 제19권4호
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• pp.243-253
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• 2013

벼 도열병은 안정적인 쌀 생산을 위협하는 대표적인 병으로, 도열병 방제에는 저항성 품종의 육종이 가장 효과적으로 이용되었다. 병원균의 꾸준한 수집과 이들을 이용한 저항성 검정 테스트는 신품종 육성 프로그램에서 중요한 과정이다. 1985년 이래 우리나라의 도열병균은 8개의 판별품종을 이용한 레이스 판별시스템을 구축하여 분류하였다. 그러나 기존의 판별품종은 유전자형이 연구된 바 없어 새로운 레이스 출현이나 병 저항성 붕괴 등에 대하여 과학적으로 분석하여 신속하게 대처하기가 어려웠다. 따라서 이 연구에서는 유전자형이 밝혀진 단인자 저항성 계통과 우리나라에서 수집된 200개 균주의 병원성 반응을 분석하여, 새로운 판별 품종 시스템의 필요성을 제시하였다. 또한, 24개의 단인자 저항성 계통의 병원성 반응을 통해 9개의 대표 저항성 유전자를 선발하였으며, 이에 따른 10개의 대표균주 그룹과 그 저항성 반응을 인덱스화 하고 30개의 한국형 대표균주를 선발하였다. 이 연구는 향후 도열병 저항성 검정 및 벼 신품종 육종에 기초자료로서 활용될 수 있을 것이다.

• 한국농공학회논문집
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• 제50권5호
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• pp.19-27
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• 2008

This study was performed to evaluate the compressive strength and acid-resistant of polymer concrete using redispersible polymer powder(RPP) and blast furnace slag powder(BSP). Material used were ordinary portlant cement, recycled coarse aggregate, natural fine aggregate, redispersible polymer powder and blast furnace slag powder. The main experimental variables were the substitution ratio of redispersible polymer powder and blast furnace slag powder, when the substitution ratios of RPP were 0, 1, 2, 3, 4, 5 and 6%, and those of BSP were 10%. The compressive strength and acid-resistant of polymer concrete using RPP and BSP were compared with those of ordinary concrete(Basis). When the substitution ratio of RPP was 1%, at age of 28 days, the compressive strength were more higher than those of Basis by 24%, and it was decreased with increasing the RPP content, respectively. Also, the water absorption ratio was decreased with increasing the RPP content. But, the acid-resistant was improved with increasing the RPP content.

• 한국식물병리학회지
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• 제2권2호
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• pp.69-81
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• 1986

성체식물기에 잎도열병에 대해 저항성인 벼 품종 선발을 위해 한국에서 재배되거나 육종재배로 쓰이고 있는 32개의 벼 품종을 도열병검정 못자리에 공시하였다. 생육시기가 다른 각 잎에 자연감염된 발병율을 토대로 비교할 때, 16개의 통일형 품종들은 모두 고도 저항성이었으나 16개의 일본형 품종들은 잎도열병에 대해 다양한 저항성정도를 나타내었다. 잎도열병에 대한 저항성정도는 품종에 따라 다르지만, 식물체가 성숙해 갈수록 양적저항성정도는 모든 품종에서 증가하였다. 감수성에서 저항성으로 바귀는 엽위는 품종에 따라 달랐다. 도열병균에 대한 품종의 감수성반응이 상위엽에서 저항성반응으로 뚜렷하게 바뀌었다. 잎도열병에 대한 양적 저항성정도가 큰 품종일수록 하위엽에서 저항성반응을 나타내었다. 생육후기에 도열병감염을 급격히 감소시키는 품종인 아까바레, 팔금, 진흥, 올찰, 도봉 및 은하는 포장에서 잎도열병에 대해 성체식물저항성을 보였다. 성체식물저항성품종들은 식물체가 성숙해감에 따라 최적, 질적으로 잎도열병에 대해 저항성을 나타내었다.

• 한국구조물진단유지관리공학회 논문집
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• 제22권4호
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• pp.83-90
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• 2018

전 세계적으로 테러의 위협이 가중되고 일반 상업건축에 대한 방폭설계의 요구가 증가하고 있는 현실을 직시하여, 본 연구에서는 기본적인 방폭설계의 개념을 정립하고 실제 설계사례를 통하여 방폭성능을 평가하는데 목표를 두고 있다. 비록 지진하중과 폭파하중에는 많은 차이점이 있지만, 그 설계법은 구조물의 소성거동을 허용하고 연성을 갖도록 설계한다는 점에서 유사하다. 본 연구에서 제시된 대상 건물에 대한 방폭성능 평가를 통하여, 일반하중에 대하여 잘 설계된 건물은 어느 정도 수준의 방폭성능을 확보하는 것으로 나타났다. 그러나 구조물에 작용하는 폭파하중은 무기의 종류, 등가의 TNT량, 폭발점에서 목표물까지의 최단거리인 촛점거리 등에 따라 달라지기 때문에 일반화하기에는 무리가 있다. 희생구조물을 배치하거나 예상되는 폭발점에서 주요 구조부재까지의 촛점거리를 일정수준 이상으로 유지하는 건축 계획적인 노력은 건물의 방폭성능을 향상시킬 수 있는 쉽고 효과적인 방법이다.

• 한국전산구조공학회논문집
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• 제37권1호
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• pp.1-8
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• 2024

본 논문에서는 확률론적 처리기법을 적용하여 플랜트 시설물의 폭발 재현주기에 따른 폭발 위험도를 분석하였다. HSE에서 제공하는 누출 데이터, DNV에서 제시한 플랜트당 연간 누출 빈도, 다양한 연구진이 제시한 점화 확률을 고려하여 누출량에 따른 폭발 재현주기를 산정하였다. 산정된 폭발 재현주기를 통해 폭발 위험도를 증기운의 부피 및 반경, 폭발하중에 대하여 평가하였다. 재현주기에 따른 증기운의 반경과 과거 실제 증기운 폭발 사례, 내폭설계 가이드라인을 비교 분석하여 설계폭발하중 모델을 위한 기준거리를 제시하였다. 멀티에너지법을 통하여 폭발 재현주기에 따른 폭발하중의 범위를 분석하였으며, 설계폭발하중 모델의 기준이 되는 재현주기를 제안하였다. 본 연구의 결과로 플랜트 시설물에 대한 성능기반 내폭설계의 간략한 표준안으로 활용이 가능하다.

• 한국식물병리학회지
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• 제13권2호
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• pp.85-89
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• 1997

Etiological components of the rice cultivars possessing durable resistance to rice blast were evaluated. In the greenhouse test by artificial inoculation, number of leaf blast lesion in Dongjinbyeo was not increased by any race of the pathogen, while the lesion number on the resistant cultivar Palgongbyeo and susceptible cultivar Jinmibyeo was increased rapidly. Size of the lesion in Dongjinbyeo was smaller and progressed more slowly than the resistant cultivar Palgongbyeo until 11 days after inoculation. Latent period in Dongjinbyeo was intermediate. However, the period was significantly variable depending upon the races. Least amount of conidia was produced in Dongjinbyeo by race KJ-107 and the number of conidia was decreased rapidly from 11 days after inoculation.

• Structural Engineering and Mechanics
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• 제63권3호
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• pp.347-359
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• 2017

Blast resistant gates are required to be lightweight and able to mitigate extreme loading effect. This may be achieved through innovative design of a gate and its supporting frame. The first is well covered in literature while the latter is often overlooked. The design of supporting frame depends mainly on the boundary conditions and corresponding reaction forces. The later states the novelty and the aim of this paper, namely, the analysis of reaction forces in supporting structure of rectangular steel gates subjected to "far-field explosions". Flat steel plate was used as simplified gate structure, since the focus was on reaction forces rather than behaviour of gate itself. The analyses include both static and dynamic cases using analytical and numerical methods to emphasize the difference between both approaches, and provide some practical hints for engineers. The comprehensive study of reaction forces presented here, cover four different boundary conditions and three length to width ratios. Moreover, the effect of explosive charge and stand-off distance on reaction forces was also covered. The analyses presented can be used for a future design of a possible "blast absorbing supporting frame" which will increase the absorbing properties of the gate. This in return, may lead to lighter and more operational blast resistant gates.