• 제목/요약/키워드: 침입성

검색결과 1,047건 처리시간 0.029초

Numerical Simulation of Unsteady Flow in Vegetated Channel : Based on Downstream of Hapcheon Dam (식생하도에서 부정류 수치모의:합천댐 직하류를 중심으로)

  • Ahn, Min Jin;Kang, Tae Un;Jang, Chang-Lae;Park, Kyoung Won
    • Proceedings of the Korea Water Resources Association Conference
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    • 한국수자원학회 2022년도 학술발표회
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    • pp.243-243
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    • 2022
  • 댐은 일반적으로 하천관리에 있어서 인간에게 용수를 공급하고 홍수를 조절하는 등의 발전을 목적으로 건설되어 운영되고 있다. 그러나 하류하천은 댐 건설에 의해 흐름에 대한 연속성이 차단되어 첨두 홍수량과 유사량이 현저하게 감소한다. 첨두 홍수량의 감소로 퇴적된 유사는 이동하지 못해 고착화가 진행되고 식생이 침입하여 번성하게 된다. 하천에 식생이 발달하게 되면, 안정성이 증가하고 생태계 서식처를 형성하며 하천경관을 개선시키는 이점이 있다. 그러나 조도의 증가와 통수능의 감소로 인한 유속감소와 수위상승을 발생시켜 홍수범람을 야기할 수 있다. 따라서 이러한 상황에 대응하기 위해서는 식생대의 밀도에 따른 흐름을 분석하여 바람직한 하천관리방안 연구가 필요할 것으로 판단된다. 본 연구에서는 2차원 흐름모형을 활용하여 황강 합천조정지댐 직하류 구간의 수목군을 고려한 부정류 계산을 통해 하도의 수위 및 유속을 예측모의하는 방법론을 제시하고 모의결과를 분석하였다. 상류단 경계조건은 과거 집중호우로 인하여 대홍수가 발생하였던 2020년 합천조정지댐 방류량 중 첨두발생 기간의 유량을 입력하였으며, 하도의 식생밀도를 산정하고 입력하기 위해 현장조사를 수행하였다. 수치모의 시 식생밀도는 총 4가지 Case(식생현황, 전체벌채, 식생개선, 식생존치)로 나누어 모의를 수행하였다. 모의결과, 직하류 만곡부 유입구간에서 외측으로 흐름이 집중되어 수심과 유속이 증가하였으며, 만곡부 외측의 식생대로 인해 식생대에서는 유속이 감소하고 수심이 증가하며, 식생대 주변 하류의 내측으로 흐름이 집중되어 수심과 유속이 증가하는 것으로 나타났다. 본 연구에서는 합천조정지댐의 실운영방류량과 황강의 실제식생밀도를 반영하여 수치모의를 하였기 때문에 흐름과 식생관리에 따른 실무적 대책방안 마련에 도움이 될 것으로 판단된다. 또한, 본 연구에서 활용한 분석방법과 결과들은 합리적인 하천관리방안을 구축하기 위한 기초자료로 활용될 수 있을 것으로 기대된다.

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Development of Convenient Screening Method for Resistant Radish to Plasmodiophora brassicae (효율적인 무 뿌리혹병 저항성 검정법 확립)

  • Jo, Su-Jung;Jang, Kyoung-Soo;Choi, Yong-Ho;Kim, Jin-Cheol;Choi, Gyung-Ja
    • Research in Plant Disease
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    • 제17권2호
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    • pp.161-168
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    • 2011
  • To establish simple and reliable screening method for resistant radish to Plasmodiophora brassicae Woron. using soil-drenching inoculation, the development of clubroot on radish seedlings inoculated with P. brassicae GN-1 isolate according to several conditions such as inoculum concentration, plant growth stage and incubation period after inoculation was studied. To select resistant radish against clubroot, 10-day-old seedlings were inoculated with P. brassicae by drenching the roots with the spore suspension of the pathogen to give $1{\times}10^9$ spores/pot. The inoculated seedlings were incubated in a growth chamber at $20^{\circ}C$ for 3 days then cultivated in a greenhouse ($20{\pm}5^{\circ}C$) for 6 weeks. Under the optimum conditions, 46 commercial cultivars of radish were tested for resistance to YC-1 (infecting 15 clubroot-resistant cultivars of Chinese cabbage) and GN-1 (wild type) isolates of P. brassicae. Among them, thirty-five cultivars showed resistance to both isolates and one cultivar represented susceptible response to the pathogens. On the other hand, the other cultivars showed different responses against the tested P. brassicae pathogens. The results suggest that this method is an efficient system for screening radish with resistance to clubroot.

Characteristics of Phytophthora capsici Causing Pepper Phytophthora Blight Resistant to Metalaxyl (Metalaxyl에 대한 저항성 고추 역병균의 특성)

  • Lee, Soo-Min;Shin, Jin-Ho;Kim, Sun-Bo;Kim, Heung-Tae
    • The Korean Journal of Pesticide Science
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    • 제13권4호
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    • pp.283-289
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    • 2009
  • Isolation frequency of resistant isolates of Phytophthora capsici to metalaxyl was reported to be 38.9% through the resistance monitoring for metalaxyl in P. capsici causing pepper Phytophthora blight. Metalaxyl was very effective to mycelium growth, while not to zoosporangium germination and zoospore release. $EC_{50}$ values of metalaxyl in the inhibition of mycelium growth were 0.204, 0.151, 0.379, and $0.215\;{\mu}g\;mL^{-1}$ against each isolate sensitive to the fungicide as P. capsici 06-119, 06-143, P08-7, and P08-31, respectively, whilst those were 5.242, 5.724, 6.621, and $5.377\;{\mu}g\;mL^{-1}$ in P. capsici 06-125, 06-155, P08-50, and P08-60. For the field fitness, several factors, which were mycelium growth, zoosporangium germination, zoospore release, virulence to pepper plants, and the zoosporangium and the oospore production, were investigated with 4 sensitive isolates and 4 resistant isolates. Between 2 groups differentiated by the sensitivity of metalaxyl, there was no significance in mycelium growth, zoosporangium germination, zoospore release, and virulence to pepper plants. However, the zoosporangium and the oospore production in each resistant isolate, which were related to survival of P. capsici in fields, were superior to those of sensitive isolates. Based on results of this study, it was suggested that the increase of the percentage of resistant isolates to metalaxyl resulted from the high capacities of the zoosporangium and the oospore production.

Classification of Cordyceps Species Based on Protein Banding Pattern (단백질 분석을 기초로한 Cordyceps속 동충하초의 분류)

  • Sung, Jae-Mo;Lee, Hyun-Kyung;Yoo, Young-Jin;Choi, Young-Sang;Kim, Sang-Hee;Kim, Yong-Ook;Sung, Gi-Ho
    • The Korean Journal of Mycology
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    • 제26권1호통권84호
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    • pp.1-7
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    • 1998
  • In order to find relationship within and between entomopathogenic species, analysis of protein band pattern in mycelia of 25 isolates was conducted by UPGMA. The results allowed differentiation of three groups on 85% similarity coefficient. Similarity coefficient within C. militaris was $0.787{\sim}1.000$, C. kyushuensis was 0.958-1.000 and C. pruinosa was 0.993-1.000. C210 and C298 isolates which had somewhat immersed perithecia, comparable to other C. militaris isolates, had 91% similarity. C108, C225-1 and C228 isolates pathogenic on Lepidopterous larvae had 89% similarity. Closely related species to C. militaris were C. kyushuensis and C. pruinosa. And similarity between C. pruinosa and C. kyushuensis was 88%. Similarity between C. bifusispora formed conidia on media and Paecilomyces tenuipes was 89%. C. scarabaeicola pathogenic specifically on adult Scarabaeidae had 82% similarity with above two species. C118 identified as C. militaris showed different protein banding patterns.

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Safety Risk Management Policy of United States small unmanned aerial system (미 소형 무인비행체계의 안전성 위험관리 정책)

  • Hong, Jin-Keun
    • Journal of Convergence for Information Technology
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    • 제11권9호
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    • pp.35-42
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    • 2021
  • The purpose of this paper is to review the small unmanned aerial system (sUAS) safety policy promoted by the United States(US) government. Therefore, in this paper, along with sUAS risk factors, the risk factors of sUAS that the US government is interested in are described. In addition, the risk factors were classified into physical and non-physical factors, and provisions mentioned in the Federal Aviation Administration(FAA) Relicensing Act were reviewed. Other risk scenarios were analyzed focusing on target scenario items that the FAA is interested in, such as flight operation disruption, infrastructure damage, and facility trespassing. Of course, we looked at the risk management principles promoted by the US FAA. In this paper, as a research method, the direction and contents of the FAA's sUAS policy were studied and reviewed from the analysis of major foreign journals and policy. In the research result of this paper, by analyzing the FAA sUAS safety risk management policy, the integrated operation and safety policy, physical risk management policy, operation and safety regulation, and sUAS policy and technology direction necessary for establishing the sUAS safety risk management guide in Korea are presented. The contribution of this study is to identify the leading US sUAS safety policy direction, and it can be used as basic data for deriving future domestic policy directions from this. Based on the research results presented in the future, policy studies are needed to derive detailed implementation plans.

Studies on Rice Varietal Resistance to Rice Stem Maggot, Chlorops oryzae Matsumura (벼줄기굴파리에 대한 수도(水稻)의 품종저항성(品種抵抗性))

  • LEE, Y.B.;HWANG, C.Y.;LEE, M.H.;Choi, K.M.;AHN, J.H.
    • Korean journal of applied entomology
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    • 제25권1호
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    • pp.27-32
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    • 1986
  • To establish a method for measuring varietal resistance against rice stem maggot in field and pot, 20 varieties were used in $1981{\sim}1983$. The degree of injured stems by the 1st generation larvae was significantly correlated with that of injured panicles by the 2nd ($r=0.864^{**}$). There was no ovipositional preference in rice stem maggot. The larval mortality after artificial infestation varied widly from 5.6 to 100% in varieties and that of the resistant varieties was high after boring. There was a negative correlation between number of injured leaves and larval mortality after artificial infestation ($'81:r=-0.833^{**},\;'82:r=-0.918^{**}$). It is considered that larval mortality mainly caused by antibiosis and larval mortality 20 days after infestation on rice seedlings is ideal for evaluating the varietal resistance to rice stem maggot. Resistant varieties are Nagdongbyeo, Jinjubyeo and Chucheongbyeo susceptible varieties, Keumgangbyeo, Milyang 23, Baigyangbyeo and Milyang 30.

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A Relation of Viscoelastic Properties to Empirical Properties of Korean Asphalt Binder (국내 아스팔트의 점탄성적 물성과 경험적 물성과의 관계)

  • Kim, Nam-Ho;Lee, Kwan-Ho
    • International Journal of Highway Engineering
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    • 제3권2호
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    • pp.113-121
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    • 2001
  • Among the currently available binder specifications, Superpave Performance Grade asphalt specification is regarded as a superior specification on its theoretical background as well as pavement performance relationship. Many difficulties are expected; however, for Superpave implementation in Korea because of heavy burden of equipment cost as well as lack of trained personnel in asphalt industry, which may too much barrier to overcome in Korean situation. As an effort to improve qualify of asphalt binder, recently, people discuss about a possibility of constituting a performance-based asphalt specification using rather easy-to-measure asphalt properties. The objective of this paper is to determine the possibility of constituting a performance-based asphalt specification using an empirical asphalt properties, such as penetration ring and ball softening point rather than using fundamental properties of asphalt. Nine straight asphalts, that covers entire straight asphalt from all Korean refineries, and eighteen modified asphalts that were modified from two modifiers were included in the study. An analysis was made through a comparison between empirical properties and Superpave PG criteria. This study concluded that it may possible to constitute a pseudo-Superpave-like specification using an empirical asphalt properties as a specification criteria. Therefore, more systematic research is needed to constitute the asphalt specification.

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Periodontal Regeneration Using the Mixture of Human Tooth-ash and Plaster of Paris in Dogs (성견에서 치아회분말과 연석고를 이용한 치주조직재생술)

  • Gu, Ha-Ra;Jang, Hyun-Seon;Kim, Su-Wan;Park, Joo-Cheol;Kim, Byung-Ock
    • Journal of Periodontal and Implant Science
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    • 제36권1호
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    • pp.15-26
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    • 2006
  • 흡수성 차페막을 이용한 조직 유도 재생술시 차폐막의 견고성으로 미루어 보아 재생을 위한 공간의 유지가 어려울 수 있다. 조직 유도 재생술과 함께 골이식술을 시행함으로써 공간 확보와 함께 적절한 혈병의 유지를 도모할 수 있고 이식된 골은 선생골 형성을 위한 핵으로 작용할 수도 있다. 최근에 사람의 치아회분말과 연석고를 혼합한 골이식재가 여러 연구를 통해 좋은 골이식재로 평가되었다. 본 연구에서는 성견 하악 소구치 2급 치근이개부위에 외과적으로 형성하여 흡수성 차폐막과 치아회분말-연석고 혼합 이식재를 이용한 조직유도재생 술을 시행하여 치주 조직 재생의 양상을 조직학적으로 관찰하고자 한다. 생후 12개월에서 16개윌 된 체중 15 Kg 내외의 성견 4마리를 이용하였다. 실험 재료로 생체흡수성 차폐막 (Biogide(R), Swiss) 를 사용하였고, 골이식재로 치아회분말-연석고를 혼합매식 하였다. 양측 상악 소구치 부위에 변연 치조골하방에 4 mm ${\times}$ 4 mm ${\times}$ 4 mm, (깊이 ${\times}$ 근원심 ${\times}$ 협설폭경) 깊이로 골내낭을 형성하였다. 형성된 골내낭의 기저부위 치근 표면에 1/4 round bur로 notch를 형성하여 참고점으로 하였다. 무작위로 선택된 한 쪽의 결손부를 대조군으로 오직 생체 흡수성 차폐막을 사용하였고, 실험군으로 치아회분말-연석고와 생체 흡수성 차폐막을 결손부로부터 2 mm 이상 덮을 수 있도록 다듬어 결손부 위에 위치시킨 후 협측 판막을 덮고 봉합하였다. 4주 후 2마리 ,8주 후 2마리를 희생시키고 통상의 방법으로 고정, 탈회, 포매의 과정을 거쳐 광학 현미경으로 검경하였다. 그 결과, 1. 4주 대조군에서 Bio-gide(R)는 완전한 흡수를 보였고, 치근이개부내에는 큰 공간이 존재하였다. 2. 4주 실험군에서 역시 Bio-gide(R)는 완전한 흡수를 보였고, 골 결손부내에 더 많은 신생골 관찰되었다. 그러나 아직까진 기존골과 신생골간에 명확한 차이가 있어서 쉽게 구분할 수 있었다. 또한 골이식재 주변으로 파골세포가 다수 관찰되며 이로 미루어 보아 활발한 골흡수가 일어남을 알 수 있었다. 3. 8주 대조군에서 결손부내에서는 기존골에 인접하여 신생골 형성이 부분적으로 일어났으나 연조직 침입이 관찰되었다. 4. 8주 실험군은 신생골이 기존골과 매우 유사한 형태로 관찰되었고, 신생골 형성 부위에 신생 혈관 증식이 관찰되었다. 또한 골내낭 기저부위에서는 백악질과, 치주인대가 재생됨이 관찰되었다. 이상의 결과에서 치아회분말-연석고 혼합매식은 골재생을 위한 골전도성이 있는 재료로 사료되며, 이를 이용히여 치주조직재생술시 흡수성 차폐막과 병행하여 사용한다면 더 많은 골재생이 있을 것으로 기대된다.

Screening of Herbal Plant extracts Showing Antimicrobial Activity against Some Food Spoilage and Pathogenic Microorganisms (일부 식품 부패성 및 병원성 미생물에 대해 항균활성을 나타내는 생약자원의 검색)

  • Ahn, Dae-Jin;Kwak, Yi-Seong;Kim, Mi-Ju;Lee, Jong-Chul;Shin, Chang-Sik;Jeong, Kee-Taeg
    • Korean Journal of Medicinal Crop Science
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    • 제8권2호
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    • pp.109-116
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    • 2000
  • This study was carried out to screen herbs among herbal plants showing antimicrobial activity against some food spoilage and pathogenic microorganisms. One hundred fifteen kinds of herbal plants were extracted by 70% ethanol, and then they have been screened for antimicroorganisms. Six herbal plants such as Salviae radix, Dryopteris rhizoma, Terminaliae fructus, Araliae radix, Psoraleae fructus and Schisandrae fructus showed strong antimicrobial activities against Bacillus subtilis. Antimicrobial activities were showed in Anemarrhena radix and Dryopteris rhizoma on Candida albicans, and in Anemarrhenae radix, Dryopteris rhizoma and Polygalae radix on Schizosaccharomyces sp. It was revealed that eight herbal plants such as Dryopteris rhizoma, Salviae radix, Sappan ligunum, Sinomeniae radix, Schisandrae fructus, Rhui fructus, Sophorae radix and Inulae radix also showed antimicrobial activities on Streptococcus mutans. In addition, Anemarrhena radix, Curcuma tuber, Inulae radix, Polygonum radix, Sanguisorbae radix, Scutellariae radix and Terminaliae fructus and showed antimicrobial activities on Trichophyton mentagrophytes. Four kinds of herbal plants such as Dropteris rhizoma, Salviae radix, Terminaliae fructus and Scutellariae radix which showed broad antimicrobial spectrums were mixed by 1 : 1 ratio with the other herbal paints showing relatively strong microbial activities such as Terminaliae fructus, Sinomeniae radix and Scutellariae radix etc. The extracts of mixed herbal paints showed higher antimicrobial activities than those of single herbal plant.

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A Case of Intracranial Tuberculoma and Optic Disc Tuberculoma Suspected by Miliary Tuberculosis (속립성 결핵에서 발생된 것으로 사료된 두개내 및 시신경 유두부의 결핵성 육이종 1예)

  • Lim, Byung-Hun;Jeon, Kyeong-Hong;Cho, Yong-Kyun;Hang, Ki-Eun;Kim, Ki-Tack;Lim, Si-Young;Kim, Byeung-Ik;Lee, Sang-Jong;Lee, Byeung-Ro
    • Tuberculosis and Respiratory Diseases
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    • 제43권2호
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    • pp.236-242
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    • 1996
  • Intracranial tuberculoma results from hematogenous spread of pulmonary, intestinal or urogenital tuberculosis. However, it might be caused by pulmonary tuberculosis, mainly. Clinically, symptoms of intracranial tuberculoma are headache and seizure, its symptoms are simillar to intracranial tumor. A 25-year-old-unmarried shopgirl was visited to this hospital because of headache, dizziness and visual disturbance for couple weeks in Sep. 1995. She had been treated with anti-tuberculosis agents of miliary tuberculosis during past nine months period. Brain MRI revealed intracranial tuberculoma and brain edema but not involved optic nerve. Ophthalmic examination revealed severe papilledema and splinter hemorrhage with bitemporal hemianopsis and central scotoma. This finding was strongly suggested of optic disc tuberculoma. Her symptoms became much better following repeated retrobulbar steroid injection with continuous anti-tuberculosis agents. We report a interesting case with intracranial tuberculoma and optic disc tuberculoma associated by miliary tuberculosis during anti-tuberculous treatment.

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