• Bulletin of the Korean Chemical Society
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• 제33권12호
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• pp.4243-4246
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• 2012

• Tribology and Lubricants
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• 제28권6호
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• pp.315-320
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• 2012

For proper functioning, general machines usually need lubricant oil as a cooling, cleaning, and sealing agent at points of mechanical contact. The quality of lubricant oil can deteriorate during operation owing to various causes such as high temperature, combustion products and extraneous impurities. In this study, a heavy load stopped during operation, and the oil was analyzed to check whether any impurities were added. Extraction using acetonitrile followed by reaction with BSTFA(bistrimethylsilyl trifluoroacetamide) showed that, trimethylsilylated ethylene glycol was present in the lubricant oil. To quantify the ethylene glycol in the oil, deuterium-substituted ethylene glycol, which acted as an internal standard, was added to the sample and then extracted with the solvent. Next, the extract was reacted with the derivatizing agent(BSTFA) and then analyzed with GC/MS. The detection limit of this method was found to be $0.5{\mu}g/g$ and the recovery of oil containing $20,000{\mu}g/g$ of ethylene glycol was measured to be 94.8%. A damaged O-ring and eroded cylinder liner were found during the overhaul, which implied the leakage of coolant containing ethylene glycol into the lubricating system. The erosion of the cylinder liner was assumed to be due to cavitation of the coolant in the cooling system.

• 한국해안해양공학회:학술대회논문집
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• 한국해안해양공학회 1996년도 정기학술강연회 발표논문 초록집
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• pp.3-6
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• 1996

On July 12, 1993, a large earthquake (M=7.8) occurred off the south-west of Hokkaido, Japan. The tsunami generated by this earthquake caused a disaster which took a heavy toll of lives, more than 200 persons dead, by the flooding of tsunami in the area of Aonae district in Okushiri island. Investigation after the disaster made clear that southern lowland was flooded by the tsunami coming from west about 5 min after the shock and the second tsunami from the east attacked eastern lowland of the Aonae District about 10 min after the shock. (omitted)

• 한국경제지리학회지
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• 제26권2호
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• pp.123-136
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• 2023

경성 동부지역 전체를 대상으로 토지가격을 살펴본 결과, 병원과 학교, 연구기관 등 근대식 주요시설이 밀집해있는 중앙부를 기준으로 북부와 남부의 토지가격대에 차이를 보이고 있었다. 이에 경성 동부지역을 세부권역(경성 동북부와 동남부)로 나눈 후, 각 세부권역별 토지시장을 분석하였다. 동북부의 경우, 중앙부로부터 거리와 시구개수가 예정된 도로와의 거리가 토지가격에 영향을 주었고, 동남부의 경우, 주요대로인 이현대로와 종로와의 거리가 토지가격에 영향을 주었다. 즉, 동북부 지역은 주요시설이 밀집해있는 중앙부의 영향이 토지시장에 미치는 배후지 성향을 지녔고, 동남부 지역은 상권을 형성하고 있는 종로의 영향이 가장 큰 상업지 성향을 지녔다. 본 연구는 100년 전 토지시장에서도 도로 및 앵커시설과의 접근성, 토지시장의 분절 등 현대 토지시장에 영향을 주는 요인들이 당대에도 유의미하게 작용했음을 밝힘으로써 근대 토지시장의 일부 단면을 살펴본 것에 의의가 있다.

• 식물분류학회지
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• 제40권1호
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• pp.74-77
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• 2010

The Illam district, situated in the extreme North Eastern part (Latitude 26.58N and 87.58E Longitude) of Nepal, is a hot spot for floral diversity. The study of wild edible plants of this region was an attempt to highlight the types of wild flowering plants found there and mode of use by the people of the Illam hills. In this respect, a survey of natural resources of some of the representative regions of the district was undertaken and more than 74 major varieties of plant species were found to be used frequently by the people of the hills. The rich diversity occurring in Dioscoriaceae, Moraceae, Rosaceae, Myrtaceae, Poaceae, Urticaceae and Arecaceae provided the wild angiospermic species commonly used by the people of the hills.

• The Journal of Asian Finance, Economics and Business
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• 제8권8호
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• pp.637-645
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• 2021

Mobile devices have become attractive learning devices for education. The digitalization of the higher education system in Sri Lanka by 2020 is part of the government's effort to modernize and enhance the country's overall education system particularly in view of the COVID-19 pandemic. Theoretically, this study contributes to the M-Learning model in higher education institutions via the integration of literature on technology adoption (TAM and UTAUT) with the variables of Perceived Usefulness, Perceived Ease of Use, Attitude, Effort Expectancy, Social Influence, and Facilitating Condition. The attitude towards M-Learning amongst higher education students was gauged via an online questionnaire survey. The convenience sample comprised 344 students from the Advanced Technological Institutes (ATI) in Batticaloa District, Sri Lanka. Descriptive statistics, a measurement, and structural model, and hypotheses testing were used to analyze the derived data. The findings indicate that mobile learning is significantly affected by perceived ease of use, social influence, effort expectancy, and facilitating condition, but negatively affected by attitude and perceived usefulness. The exhaustive literature review revealed that there are very few M-Learning studies related to digital learning in the context of higher education in the Batticaloa district.

• 식물분류학회지
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• 제42권3호
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• pp.222-246
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• 2012

이 연구는 세계 39개 생물다양성 hot spot중에 하나인 인도 동부 히말라야 상부 Siang 지역의 식물상을 4년 동안 조사한 결과물이다. 이 지역의 식생에 대한 분석결과와 함께 조사된 총 1,003분류군, 110과, 529속, 994종, 1아종 그리고 8변종의 피자식물 목록을 첨부하였으며 1신종, 3미기록종 및 82특산종을 포함하고 있다. 초본과 관목의 다양성이 교목보다는 높게 나타났으며 과별로는 벼과, 콩과 그리고 난과 순으로 다양성이 우세한 것으로 조사되었다. 이 지역의 절멸위기에 처한 종들을 보고함과 동시에 급속한 도시화와 화전은 자연식생의 직접적인 절멸을 가속화하고 있어 이 지역의 자연유산을 보호하고 보존하는 방법을 찾는데 도움이 되기를 제안한다.

• 한국안전학회지
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• 제26권2호
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• pp.42-47
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• 2011

Going underwater is supposed to begin with the history of human beings. At first it was confined to relatively shallow level, less than several meters by holding breath. Recently, deep level diving has been necessary for such purpose as construction, maritime salvage, military operations, research and sports by using SCUBA(self-contained underwater breathing apparatus) equipment. As one goes down into water, the pressure on the diver is increased due to water pressure with depth, usually 1 atm for each 10 m water level. In deep water, mixed gas or nitrox(EAN, enriched air nitrox) could be applied for the divers lest they should get disease due to high pressure. Of these, the former is usually composed of oxygen and inert gas like helium or hydrogen, the latter contains higher oxygen content than that in normal air in which the oxygen concentration is designated by the character "EAN" followed by vol. % of oxygen, for example, "EAN 40" contains 40% of oxygen. In this case, a victim was found at the 39 m below the sea surface breathing air and nitrox in cylinder wrongly marked as EAN 36, which was analyzed to contain 63% of oxygen by GC/TCD. The cause of death could not be exactly related with the oxygen content in the nitrox cylinder, because the accurate depth for the victim to dive was not known, even though the victim was just found at the depth of 39 m. However, the wrongly marked nitrox could be believed to be the main cause of the death at the depth unless there happened any other accident except that during diving.

• Journal of Contemporary Eastern Asia
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• 제15권1호
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• pp.4-16
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• 2016

A large literature identifies perceptual differences between citizens that support winning parties versus losing parties. These analyses fail to capture the complexity of mixed member legislative systems where one can be a winner or loser at both the national and district level. This paper proposes a two-level framework for the analysis of mixed system. An analysis of Taiwan’s first election under a mixed system provides evidence that both support for a national winner and district level winner produce boosts in positive perceptions of the electoral system. National success appears to be a larger motivator of perceptions.

• 분석과학
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• 제23권6호
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• pp.544-550
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• 2010

담홍색 열매체유를 포도주로 오인하고 음용하여 사망한 변사사건에서 열매체유 중 39%의 에틸렌글리콜을 확인하였다. 열매체유는 물을 열전달 매체로 사용하였을 경우 고온에서 발생되는 고압 수증기에 의한 문제를 피하기 위하여 사용되는 열전달 매체로 주로 광유계 또는 에틸렌글리콜을 사용하는 것으로 알려져 있다. 부검을 통한 혈액 및 기타 조직 등의 변사자 생체시료에서 중수소로 치환된 에틸렌글리콜을 내부표준물질로 하여 아세토니트릴로 추출, 정제 및 질소 기류하에서 농축한 다음 1% TMCS가 함유된 BSTFA로 유도체화하여 에틸렌글리콜과 그 대사체인 글리콜산을 GC/MS에 의하여 동시 분석하였다. 약 0.2 g의 생체시료에 대하여 0.5 M의 HCl 용액 $50\;{\mu}L$를 이용한 산성조건에서 추출하였으며 무수 황산나트륨을 단계적으로 처리하여 수분제거를 하였고 혈액에서 $2,755\;{\mu}g/mL$의 에틸렌글리콜과 $174\;{\mu}g/mL$의 글리콜산 및 기타 시료에서 $860\;{\mu}g/g\sim1,290\;{\mu}g/g$의 에틸렌글리콜과 $93\;{\mu}g/g\sim134\;{\mu}g/g$의 글리콜산을 검출하였다. 특히 신장 조직에서 이와 관련된 대사체인 옥살산염으로 추정되는 결정이 관찰되었다.