• Journal of Korean Society of Environmental Engineers
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• v.35 no.7
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• pp.503-508
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• 2013

The aim of this study was to investigate the microbial communities in animal carcass disposal soils to examine the possible threat of pathogens from leachate. DNA extraction was performed for the soils in three carcass disposal sites located in Gyeonggi-do, Korea, and then 16S rRNA pyrosequencing was conducted to identify the microbial communities. Results indicate that, according to phylum classification, Proteobacteria (100%) was identified in soil A, Actinobacteria (66.4%) > Proteobacteria (31.1%) > Bacteriodetes (2.1%) > Acidobacteria (0.3%) in soil B, and Actinobacteria (63.1%) > Proteobacteria (36.9%) in soil C. According to genus classification, Pseudomonas was dominant in soil A (98%), Arthrobacter in soil B (68%) and C (61%). There were no detections of pathogens such as Salmonella, Campylobacter and Clostridium perfringens. However, high concentration of Ralstonia pickettii causing bacteremia was observed. Although carcass disposal soils examined in this study were not highly contaminated with pathogens, further monitoring is still needed to examine the potential threat of pathogens in leachate derived from carcass disposal sites.

• Research in Plant Disease
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• v.13 no.2
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• pp.88-92
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• 2007

A total of 41 Pseudomonas syringae pv. syringae, the causal agent of bacterial blossom blight, were isolated from kiwifruit plants in Korea. Among them, two strains showing streptomycin resistance were examined to investigate the structure of resistant determinants by PCR and nucleotide sequence analysis. PCR results suggested that the streptomycin resistance is mediated by strA-strB genes carried on Tn5393a. Insertion sequences, IS6100 and IS1133, which were located within or downstream of tnpR gene in Xanthomonas campestris and Erwinia amylovora were not found. Nucleotide sequences of strA-strB were 100% identical with Tn5393a. Two stretomycin resistant strains had three plasmids. Southern blot hybridization using strA-strB probe indicated that the resistant genes were carried on a 100kb plasmid.

• Journal of dental hygiene science
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• v.7 no.1
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• pp.13-20
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• 2007

This study is aimed at providing basic data for measures to prevent dental hygienists who are highly exposed to hepatitis-B virus due to their characteristic working conditions from being infected of it. In order to determine their perception and the extent of their exposure to the risk of infection with hepatitis-B virus, a survey was conducted with questionnaires distributed to 354 dental hygienists who are working at dental offices in Seoul. Gyeongi and Jeolla provincial areas. From the survey, following conclusions could be drawn: 1. Sixty three point seven to 100 percent of them are found to have been vaccinated against hepatitis-B virus as is generally expected from their working environment. 2. Their general characters are found to be statistically significant in terms of vaccinating point of time among those who have been vaccinated. Most respondents are either vaccinated one year or 5 years ago. The completion of 3 requested vaccinations lies in the level of 64.3%~100% depending on the general characters. By age, the best result comes from the age group of 25~29, followed by the groups older than 30 and 20-24 in order (p < 0.05). Formation of antibody belongs to the level of 45%~100% generally. But statistically significant of them is the extremely unhealthy state with 100%, followed by normal, generally healthy, very healthy and not healthy in sequence (p < 0.05). 3. In terms of family's clinical history, it is known that the older (p < 0.01), the more unhealthy (p < 0.01) and the married (p < 0.01), the more possibility of having anamnesis of hepatitis-B virus infection. 4. The level of knowledge about Hepatitis-B virus is shown to be in the extent of 4.39~5.01 out of maximum 8 points in general terms. 5. It is revealed that there are high chances for dental hygienists to get spattered with body matters of patients like blood or sputum on their faces in general characters (87.%~100%). 6. A high rate (75%~100%) of respondents has experienced being shot by needles. The older(p < 0.05) and the longer(p < 0.05) their career, the higher the rate becomes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.1
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• pp.90-94
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• 1998

Antimutagenic and antimicrobial effects of the ethanol extracts from sea-mustard and sea-tangle were investigated. Antimutagenic effects of ethanol extracts from sea-tangle were higher than those of sea-mustard. Seventy and ninety percent ethanol extracts from sea-tangle showed high antimutagenic effects on NDMA-induced mutations in TA100 and TA102. Fifty percent of ethanol extract from sea-mustard showed high antimicrobial effect against S. cerevisiae, while 70 and $90\%$ ethanol extracts from sea-tangle against B. subtilis and E. coli.

• Korean Journal of Ecology and Environment
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• v.44 no.2
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• pp.187-194
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• 2011

This study analyzed the A1B climate change scenario provided by National Institute of Meteorological Research (NIMR), Korea, to investigate potential climate changes in watersheds of 15 multi-purpose dams in South Korea. The A1B climate change scenario is produced by Regional Climate Model (RCM) with 27 km horizontal grid spacings using a one-way nesting technique with Global Climate Model (GCM). Relative to present climate conditions (1971~ 2000), the modeled 10-year averaged daily temperatures at the watersheds of the 15 multi-purpose dams continuously increased to year 2100, whereas precipitation changes were varied regionally (north, central, and south regions of South Korea). At two watersheds located in Gangwon-province (north region), the modeled temporal variations of precipitation rapidly increased in the 2090's after a slow decrease that had occurred since the 2050's. At seven watersheds in the central region, including Gyeongsangbuk-province to Jeollanam-province, the modeled temporal variations of precipitation increase showed 10-year periodic changes. At six watersheds in the south region, the modeled temporal variations of precipitation increased since the 2070's after a rapid decrease in the 2060's. Compared to the climate conditions of the late of 20th century (1971~2000), the number of rainy days and precipitation intensity increased (3% and 6~12%, respectively) in the late 21st century (2071~2100). The frequency of precipitation events tended to increase with precipitation intensity in all regions. The frequency of heavy precipitation events (>50 mm $d^{-1}$) increased with >100% in the north region, 60~100% in the central region, and 20~60% in the south region.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.07a
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• pp.227-230
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• 2010

본 논문은 디지털 케이불망에서 초고선명 TV(Ultra High Definition TV) 서비스를 위한 100Mbps급 1024-QAM 전송시스템 개발에 관하여 기술한다. 8K-UHD TV(해상도 7680x4320) 콘텐츠 전송을 위해서는 l개의 프로그램당 약 100-160Mbps의 대용량 데이터 전송률이 확보되어야 하며. 이러한 대용량 데이터 전송을 위해 타매체에 비해 상대적으로 전송채널 환경이 우수한 디지털 케이블망(HFC:Hybrid Fiber and Coaxial)을 이용한 대용량 실감데이터 전송기술에 대한 연구가 주목받고 있다. 본 논문에서는 이와 같은 UHD 실감콘텐즈 전송을 위하여, OpenCable(J.83 Annex B) 확장형 1024-QAM 송수신기술 및 방송망 채널본딩기법을 적용한 100Mbps급 송수신 기술개발에 대한 내용을 기술한다.

• YAKHAK HOEJI
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• v.46 no.1
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• pp.11-17
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• 2002

$\beta$-Immunan, a proteoglycan, was isolated from the mycelium of Canoderma lucidum which belongs to a medicinal mushroom. The effects of $\beta$-Immunan on cell-cell and cell-matrix interactions mediated by carbohydrate-recognition and the mechanism responsible for the inhibition of experimental metastasis of Bl6-F10 and B16/BL6 murine melanoma were studied. The results showed that $\beta$-Immunan inhibited Bl6-Fl melanoma cell's adhesion to laminin and asialofetuin-induced homotypic aggregation and reduced invasion against Bl6-F10 murine melanoma cells through matrigel in vivo assay. When $\beta$-Immunan was intraperitoneally administrated to C57B/6 mice bearing B16/BL6 murine melanoma cells, it was decreased the number of pulmonary metastatic colony by the dose dependent manner ranging from 20 to 100 mg/kg/day. The results indirectly indicate that clinical treatment with $\beta$-Immunan might be expected to exhibit anti-metastatic effect. In the pulmonary metastasis, the number of pulmonary metastatic colony of melanoma when $\beta$-Immunan was intraperitoneally administrated to C57BL/6 mice bearing B16/BL6 murine melanoma cells by intravenous injection were decreased by the dose dependent manner ranging from 20 to 100 mg/kg/day.

• Journal of the Korean Ceramic Society
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• v.40 no.6
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• pp.547-552
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• 2003

ZnO thin films on glass substrate were deposited by RF magnetron reactive sputtering at 100 W, 1.33 Pa, Ar/O2=50 : 50, 200$^{\circ}C$, and a target/substrate distance of 4 cm. Crystallinities, surface morphologies, chemical compositions, and electrical properties of the films were investigated by XRD, SEM, AFM, RBS, and electrometer. All films showed a strong preferred c-axis orientation and the chemical stoichiometry. The propagation velocity of ZnO/IDT/glass of single electrode and double electrode types SAW filter was about 2,589 m/sec, 2,533 m/sec and insertion loss was a minimum value of about -11 dB and -21 dB, respectively.

• Proceedings of the KAIS Fall Conference
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• 2004.11a
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• pp.103-106
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• 2004

플라스틱 무선부품에서 발생하는 전자파를 차폐하기 위한 도금연구를 하였다. ABS 수지상에 습식도금법과 기상도금법을 이용하여 전기전도도가 우수한 Ag를 도금하였다. Sputtering공정시 압력, 시간, 전력이 증가함에 따라 Ag 입자가 조대화되고 증착속도가 증가되었다. 그리고 탈지 후 plasma, 탈지 후 Etching, 인가 전력 70W$\~$110W, 증착압력 4×10-2torr이하, 증착시간 5min$\~$6min에서 5B의 밀착력과 100dB 이상의 차폐효과가 계산되었다. 무전해 Ag 도금의 경우 최고 0.47$\mu$m/min의 도금속도와 plasma를 이용한 도금 전처리가 깨끗한 도금표면을 나타냈고 모든 조건에서 5B의 밀착력을 나타냈으며 100dB 이상의 차폐효과가 계산되었다.

• Advances in materials Research
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• v.11 no.1
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• pp.59-73
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• 2022

In the construction industry, thin-walled frame elements with very slender open cross-sections and low torsional stiffness are often subjected to a complex loading condition where axial, bending, shear and torsional stresses are present simultaneously. Hence, these often fail in instability even before the yield capacity is reached. One of the most common instability conditions associated with thin-walled structures is Lateral Torsional Buckling (LTB). In this study, a first order Generalized Beam Theory (GBT) formulation and numerical analysis of cold-formed steel lipped channel beams (C80×40×10×1, C90×40×10×1, C100×40×10×1, C80×40×10×1.6, C90×40×10×1.6 and C100×40×10×1.6) subjected to uniform moment is carried out to predict pure Lateral Torsional Buckling (LTB). These results are compared with the Finite Element Analysis of the beams modelled with shell elements using ABAQUS and analytical results based on Euler's buckling formula. The mode wise deformed shape and modal participation factors are obtained for comparison of the responses along with the effect of varying the length of the beam from 2.5 m to 10 m. The deformed shapes of the beam for different modes and GBTUL plots are analyzed for comparative conclusions.