• Title/Summary/Keyword: 연쇄

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Radionuclides Transport from the Hypothetical Disposal Facility in the KURT Field Condition on the Time Domain (KURT 부지 환경에 위치한 가상의 처분 시설에서 누출되는 방사성 핵종의 이동을 Time Domain에서 해석하는 방법에 관한 연구)

  • Hwang, Youngtaek;Ko, Nak-Youl;Choi, Jong Won;Jo, Seong-Seock
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.10 no.4
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    • pp.295-303
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    • 2012
  • Based on the data observed and analyzed on a groundwater flow system in the KURT (KAERI Underground Research Tunnel) site, the transport of radionuclides, which were assumed to be released at the supposed position, was calculated on the time-domain. A groundwater pathway from the release position to the surface was identified by simulating the groundwater flow model with the hydrogeological characteristics measured from the field tests in the KURT site. The elapsed time when the radionuclides moved through the pathway is evaluated using TDRW (Time Domain Random Walk) method for simulating the transport on the time-domain. Some retention mechanisms, such as radioactive decay, equilibrium sorption, and matrix diffusion, as well as the advection-dispersion were selected as the factors to influence on the elapsed time. From the simulation results, the effects of the sorption and matrix diffusion, determined by the properties of the radionuclides and underground media, on the transport of the radionuclides were analyzed and a decay chain of the radionuclides was also examined. The radionuclide ratio of the mass discharge into the surface environment to the mass released from the supposed repository did not exceed $10^{-3}$, and it decreased when the matrix diffusion were considered. The method used in this study could be used in preparing the data on radionuclide transport for a safety assessment of a geological disposal facility because the method could evaluate the travel time of the radionuclides considering the transport retention mechanism.

Counter Measures of the Subway Terrorism through Case Analysis (사례분석을 통한 지하철 테러에 대한 대책)

  • Kwon, Jeong-Hoon;Kim, Tae-Hwan;Choi, Jong-Gyun
    • Korean Security Journal
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    • no.18
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    • pp.1-20
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    • 2009
  • Nowadays most nations around the world including Korea have experienced absolute shortages of available urban space. To solve various problems of the city, each nation constantly tends to extend the underground space. However there is a serious problem in making use of the underground space. Especially new terrorism coming into existence after 9.11 terror turns into the so-called ‘soft target’ which has something to do with public transportation facilities available to most people. Good examples are like these: poisonous gas attacks in Tokyo subway in 1995, Daegu subway station fire in 2003, serial bomb blast of London subway in 2005. In spite of being a concern on incidents related to the underground space it is inevitable to utilize the underground space and the tendency is growing. But Korea lags badly behind in foreign countries in this field and so seeking measures is urgently needed. Therefore the aim of this study is to note visible damages stemmed from the domestic and foreign underground space and propose more effective and adequate measures. Safety measures of terrorism are associated to minimize damage out of terrorism and they are as follows. In the first place, preparing protective equipment for saving a life from fire attacks and poisonous gas is needed urgently. In the second place, counterpart management on the spot and systematic security training should be established in order to minimize injury. In the third place, fire escapes must be provided for a rapid evacuation of potential unspecified individuals. In the fourth place, building up a network of related institutions is required for a systematic omnidirectional counterpart. Finally the Korean government ought to take fast and appropriate actions for the injured and bereaved family of the terror incident.

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Alternative Design of Mega Structural Members of a Super-tall Building using 800MPa Grade High-performance Steel Plate (800MPa급 고성능 강재 적용한 초고층 메가 부재 대안설계)

  • Cho, So Hoon;Kim, Do Hwan;Kim, Jin Won;Lee, Seung Eun;Kim, Jin Ho
    • Journal of Korean Society of Steel Construction
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    • v.26 no.4
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    • pp.299-309
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    • 2014
  • HSA800 is a new high strength steel (HSS) plate for building structures developed by POSCO and RIST in 2011. It has upper and lower bounds for yield ($F_y$) and tensile ($F_u$) strength as of 650-770MPa and 800-950MPa, respectively, with yield ratio ($F_y/F_u$) limit as of 0.85 which make steel quality more reliable and enhance the seismic resistance of structures. As made by TMCP, it has a good weldability without increasing carbon percentage. The objective of this study is to provide alternative design of mega-structural members of the Lotte World Tower (555m, 123 story), a first super-tall building in Korea, using HSS considering structural safety, constructability, and cost-effectiveness. Steel outrigger trusses, belt-trusses and steel exterior columns were selected and analyzed to evaluate the structural performance between original and alternative designs using HSS. The results show that HSS can be applied to the members which do not affect lateral stiffness of a building and, in this study, approximately 1100tons of steel were saved. It implies that HSS can save overall construction costs - manufacturing, delivery, and erection costs - by reducing mega structural member size. HSA800 was very first applied to the Lotte World Tower based on the results of this study.

Community-acquired Extended-spectrum and Plasmid-mediated ampC Beta-lactamase-producing Multidrug-resistant Enterobacter cloacae Septicaemia in a Cat with Euthyroid Sick Syndrome (정상 갑상샘 질환 증후군 고양이의 지역사회획득 광범위 및 플라스미드 유래 ampC beta-lactamase 양성 다약제내성 Enterobacter cloacae 패혈증)

  • Han, Jae-Ik;Na, Ki-Jeong
    • Journal of Veterinary Clinics
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    • v.32 no.2
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    • pp.191-195
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    • 2015
  • A 7-year-old castrated male Korean Shorthair cat was referred with lethargy and anorexia. Laboratory examination revealed moderate degenerative changes of peripheral neutrophils on blood smear examination and decreased levels of free and total thyroxine ($T_4$) as well as bacterial growth on blood culture. Molecular analyses of the 16S ribosomal RNA gene and heat shock protein 60 gene confirmed the bacterium as Enterobacter cloacae. A minimal inhibitory concentration test showed multidrug resistance of the bacterium against 16 antibiotics. Polymerase chain reaction (PCR) and subsequent sequencing specifically for $bla_{TEM}$, $bla_{SHV}$, $bla_{CTX-M}$, and plasmid-mediated ampC genes revealed positive results to $bla_{TEM-1}$, $bla_{CTX-M-15}$, and plasmid-mediated $bla_{ACT-1}$ genes, indicating that the isolated bacterium contains plasmids containing genes encoding extended-spectrum beta-lactamase and plasmid-mediated ampC beta-lactamase. After 1 month of treatment with antibiotics and levothyroxine, the cat's condition improved; both the thyroid function test and the blood culture showed no abnormalities. This is the first report of community-acquired multidrug-resistant E. cloacae-induced euthyroid sick syndrome in a cat. By the prompt diagnostic procedures and properly selected antibiotic therapy, the cat was recovered from the multidrug-resistant bacterium-induced septicaemia.

Occurrence of Enterocytozoon bieneusi in Korean Native Cattle Examined by Light Microscopic and Molecular Methods (광학 현미경 및 분자생물학적 방법을 적용한 한우의 Enterocytozoon bieneusi 역학조사)

  • Lee, John-Hwa;Kim, Nam-Soo;Jeon, Byung-Woo;Son, Hwa-Young;Ryu, Si-Yun;Shin, Hyun-Jin;Park, Jie-Yeun;Kim, Hyeon-Cheol;Hur, Jin;Cho, Jeong-Gon;Park, Bae-Keun
    • Journal of Veterinary Clinics
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    • v.27 no.1
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    • pp.1-5
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    • 2010
  • Enterocytozoon bieneusi, a microsporidian species, has emerged as an opportunistic pathogen in AIDS patients. This organism has also been identified in a wide range of animals, and the zoonotic potential of human infections is of particular interest. This study revealed that this organism was found with relatively high prevalence in feces of asymptomatic cattle in Korea. Fecal specimens were obtained from a total of 1,720 cattle in a slaughterhouse located in Chungnam province, Daejeon city and Chonbuk province. After removal of fecal debris by sieving and density gradient centrifugation, samples were examined by microscopic examination and then nested polymerase chain reaction (PCR). Microscopic examination with the modified trichrome staining for the fecal specimens revealed 194 (11.28%) positive calves for microsporidia spore. PCR using the specific primer for E. bieneusi revealed 79 (4.59%) positive calves. The infection ratio of microsporidia was higher in March than other season.

Transgene structures of marker-free transgenic Bt rice plants (무선발 형질전환 Bt벼의 도입유전자 구조 분석)

  • Woo, Hee-Jong;Lee, Seung Bum;Lim, Myung-Ho;Gwon, Sun-Jong;Lee, Jin-Hyoung;Shin, Kong-Sik;Cho, Hyun-Suk
    • Journal of Plant Biotechnology
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    • v.40 no.3
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    • pp.135-140
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    • 2013
  • A less simple approach developed for generation of marker-free transgenic plants is to select transformants without the use of selective marker genes. Some results about development of marker-free transgenic plants were obtained using a non-selective approach in several crops such as rice, potato and tobacco. However, the study did not provide evidence on detailed characterization of introduced gene on genome, a critical step for confirming the stable integration and transmission of a foreign gene. In this study, we evaluated structure and integration sites of transgene (mCry1Ac) in the transgenic Bt rice plants which were made via conventional Agrobacterium-mediated transformation by non-selective method. Structure and integration sites of transgene in these transgenic plants had similar fashion as those recovered under selection.

Sex determination of bovine embryos with hamster H-Y antibody and by polymerase chain reaction (햄스터 H-Y항체와 중합효소연쇄반응을 이용한 소 수정란의 성감별)

  • Yu, Il-jeong;Kim, Yong-jun;Lee, Kyung-kwang
    • Korean Journal of Veterinary Research
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    • v.39 no.1
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    • pp.189-203
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    • 1999
  • To determine sex of bovine embryos using hamster histocompatibility Y(H-Y) antibodies, bovine compact morulae were incubated for 6 hours in TCM199 supplemented with 10% hamster H-Y antiserum and the embryos with developmental arrest were diagnosed as male embryos, while the embryos showing development during the incubation as female embryos. This presumptive embryo sexing was confirmed by polymerase chain reaction(PCR)method. 1. In the result of hamster sperm cytotoxicity test to measure H-Y antibody titer, the rate of dead sperm was considerably lower in H-Y antiserum absorbed with hamster male splenocytes than in H-Y antiserum absorbed with hamster female splenocytes or H-Y antiserum unabsorbed with splenocytes(p<0.01). 2. The rate of oocytes fertilized in vitro and the rate of blastocysts of the fertilized oocytes were 58.5% and 32.4%, respectively. The rate of blastocysts on day 8 was 15.9%, denoting the highest rate during whole culture period posterior to in vitro fertilization (IVF). 3. The bovine 16 cell and compact morulae embryos incubated in the medium supplemented with hamster H-Y antibodies showed 37.1% and 48.9% of developmental arrest which were diagnosed as male, respectively, and rates of redeveloped embryos from the arrested were 24.1% in 16 cell and 44.3% in compact morulae embryos, respectively, denoting higher rate of sex determination and rate of redevelopment in compact morulae than 16 cell embryos. 4. Bovine compact morulae of Korean cattle and Holstein were treated with hamster H-Y antibodies for sex determination and the rates of developmental arrest(diagnosed as male) were 48.4% for Korean cattle and 47.9% for Holstein, respectively. The rates of redeveloped embryos to blastocyst after treatment were 42.6% for Korean cattle and 41.8% for Holstein, respectively, showing no significant differences of sex determination and redevelopment between both breed. 5. The sex determination of bovine embryos(Korean cattle and Holstein) using hamster H-Y antibodies was diagnosed by PCR for confirmation, denoting the rates of 86.1% for Korean cattle and 85.9% for Holstein male embryos, respectively, and the rates of 91.9% for Korean cattle and 90.1% for Holstein female embryos, respectively, with no significant differences of sex determination between both breed. These results indicated that hamster H-Y antibodies can be usable for sex determination of bovine embryos of Korean cattle and Holstein, the viability of bovine embryos was sustained while being cultured in the medium supplemented with hamster H-Y antibodies of appropriate titer and sex determination of bovine embryos by PCR can be feasible for confirmation.

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Evolution of sea Urchin Strongylocentrotus intermedius Based on DNA Sequences of a Mitochondrial Gene, Cytochrome c Oxidase Subunit I (미토콘드리아 유전자, 치토그롬 옥시다제(subunit I)의 염기서열을 이용한 새치성게(Strongylocentrotus intermedius)의 진화과정 분석)

  • Lee, Youn-Ho
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.5 no.2
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    • pp.157-168
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    • 2000
  • Sea urchin S. intermedius occurring in the Korean east coast is a cold water species that belongs to the family Strongylocentrotidae of Echinoidea. Although it is known that there are nine species in the family, species identification criteria, phylogenetic relationships, time and process of evolution of the family members have not been uncovered clearly. In the present study, I tried to find some clues to such problems for S. intermedius by means of DNA sequences. For this, cytochrome c oxidase subunit I (COI), one of the mitochondrial genes that evolve fast and follow maternal inheritance was analyzed. DNA was extracted from the female gonad of S. intermedius, a segment of COI gene amplified by polymerase chain reaction (PCR), and finally a total of 1077 base pair sequence of COI obtained by cloning and sequencing the PCR product. The sequence was compared with homologous genes of other sea urchins and echinoderm species. Phylogenetic trees of the COI gene segment revealed that S. intenedius is a sister species of S. purpuratus which lives along the east coast of the Paciflc. With reference to the fossil records of sea urchins and genetic distances in the molecular phylogenies, it is estimated that the two species were separated about 0.89 million years ago when the earth temperature fluctuated significantly. The current disjunct distribution patterns of the two species and the climate change of the earth at the time of separation suggest that speciation might have occurred by vicariance. The COI gene sequence obtained here now can be used as a molecular character which discerns S. intermedius from the other sea urchin species of Strongylocentrotidae.

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Cause Analysis on Dry of stream flow for the Ui-Cheon (우이천의 건천화 원인분석)

  • Yi, Choong Sung;Choi, Seung An;Kim, Hung Soo;Shim, Myung Pil
    • Proceedings of the Korea Water Resources Association Conference
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    • 2004.05b
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    • pp.753-758
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    • 2004
  • 건천화란 하천이 건천이 되어가는 과정이라고 할 수 있다. 그러나 이의 정량적 접근이 어려운 이유는 건천이 되어가는 과정에 대한 현상을 지속적으로 관찰하기 어렵고, 순수한 자연현상이라기보다 인위적 요소가 간섭한 결과이기 때문이다. 본 연구는 건천이 되어가는 하천 중에서도 도시화에 의한 건천화의 영향이 큰 것으로 보이는 우이천 유역에 대해 건천화의 원인을 분석하여 몇 가지 결론과 대책을 제시하였다. 우이천은 유역면적 $27.67km^2$, 유로연장 11.75km의 비교적 좁은 면적 내에 인구 461,351명이 거주하고 주변 행정구역 총 인구가 604,282명인 지방2급하천이다. 유역 내 북부와 북서부의 산악지역을 통과하는 상류는 대부분 계류(溪流)로서 자연상태를 유지하고 있으나, 중${\cdot}$하류는 양안의 셋방, 복개, 직강화, 보 및 낙차공 등 인공구조물로 인해 하천형상이 크게 왜곡되어 있는 전형적인 도시하천유역이다. 본 연구는 우이천에 대한 건천화 원인분석을 위해 크게 4가지 방봅으로 접근하였는데 반분포형 유출모형인 TOPMODEL에 의한 장기유출분석, 수문${\cdot}$기상자료에 의한 분석, 인문${\cdot}$사회자료의 분석, 지하수위 분석 등이었다. 분석결과 우이천 유역과 같이 장기간에 걸쳐 도시화가 진행된 유역은 수문순환계의 왜곡이 돌이킬 수 없는 수준이므로, 적절한 건천화 방지대책의 방향은 건천화의 원인이 되는 인자를 제거함으로써 줄어든 유량을 회복하는 방안보다는 인위적이고 강제적인 방식으로 추가적인 하천수량을 확보하는 것이 타당하다 사료된다. 하천의 건천화는 하나의 주된 원인이 지배적일 수도 있지만 간접적인 영향이 많고, 하나의 원인이 다른 인자에 영향을 주어 연쇄적인 영향을 미칠 수도 있는 복잡한 현상이다. 따라서 다양한 각도에서 다양할 접근방식으로 방지대책을 수립하여야 할 것이다.적에 따른 임계지속기간과 유출량의 변화를 검토해 보았다.이를 각각의 경우의 해석해 결과와 비교${\cdot}$분석하였다. 후방추적 퍼프모형은 전방추적 퍼프모형에 비하여 사용된 퍼프수와 관계없이 작은 오차를 발생하였으며, 전체적으로 퍼프 모형이 입자모형보다는 훨씬 적은 수의 계산을 통해서도 작은 오차를 나타낼 수 있다는 것을 알 수 있었다. 그러나 Gaussian 분포를 갖는 퍼프모형은 전단흐름에서의 긴 유선형 농도분포를 모의할 수 없었고, 이에 관한 오차는 전단계수가 증가함에 따라 비선형적으로 증가하였다. 향후, 보다 다양한 흐름영역에서 장${\cdot}$단점 분석 및 오차해석을 수행한 후에 각각의 Lagrangian 모형의 장점만을 갖는 모형결합 방법을 제시할 수 있을 것으로 판단된다.mm/$m^{2}$로 감소한 소견을 보였다. 승모판 성형술은 전 승모판엽 탈출증이 있는 두 환아에서 동시에 시행하였다. 수술 후 1년 내 시행한 심초음파에서 모든 환아에서 단지 경등도 이하의 승모판 폐쇄 부전 소견을 보였다. 수술 후 조기 사망은 없었으며, 합병증으로는 유미흉이 한 명에서 있었다. 술 후 10개월째 허혈성 확장성 심근증이 호전되지 않아 Dor 술식을 시행한 후 사망한 예를 제외한 나머지 6명은 특이 증상 없이 정상 생활 중이다 결론: 좌관상동맥 페동맥이상 기시증은 드물기는 하나, 영유아기에 심근경색 및 허혈성 심근증 또는 선천성 승모판 폐쇄 부전등을 초래하는 심각한 선천성 심질환이다. 그러나 진단 즉시 직접 좌관상동맥-대동맥 이식술로 수술적 교정을 해줌으로써 좋은 성적을 기대할 수 있음을 보여주었다.특히 교사들이 중요하게 인식하는 해방적 행동에 대한 목표를 강조하여 적용할 필요가 있음을 시사하고 있다.교하여 유의한 차이가 관찰되지 않았다. 또한 HSP 환자군에서도 $IL1RN^{*}2$ allele 빈도와 carria

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Study on Laboratory Diagnosis of the Ebola Virus and Its Current Trends (에볼라 바이러스 진단법과 개발 동향에 관한 고찰 연구)

  • Jeong, Hye Seon;Kang, Yun-Jung
    • Korean Journal of Clinical Laboratory Science
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    • v.47 no.3
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    • pp.105-111
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    • 2015
  • In late December 2013, the Ebola virus emerged from West Africa. The outbreak started in Guinea and rapidly spread to Liberia and Sierra Leone. Initially, the virus is spread to the human population after contact with infected wildlife and then spread person-to-person through direct contact with body fluids such as blood, sweat, urine, semen, and breast milk. The Ebola virus infects endothelial cells, mononuclear phagocytes and hepatocytes. It causes massive damage to internal tissues and organs, such as blood vessels and the liver, and ultimately death. Most tests for the virus RNA rely on a technology called reverse-transcriptase polymerase chain reaction (RT-PCR). While this method is highly sensitive, it is also expensive, requiring skilled scientists, and delicate power supplies. The strip analytical technique (enzyme-linked immunosorbent assay or ELISA) detects antigens or antibodies to the Ebola virus. This test is cheap and does not require electricity or refrigeration. Despite ongoing efforts directed at experimental treatments and vaccine development, current medical work on the Ebola viral disease is largely limited to supportive therapy. Thus, rapid and reliable diagnoses of the Ebola virus are critically important for patient management, infections, prevention, and control measures.