• 한국전문물리치료학회지
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• 제9권4호
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• pp.13-35
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• 2002

Lesch-Nyhan 증후근(LNS)은 hypoxanthine guanine phosphoribosyle transferase(HGPRT) 효소를 암호화 하는 X 염색체가 불완전해서 일어나는 유전적인 추제외로계(또는 기저핵)의 드문 병변이다. 출생시 LNS 유아는 정상적인 운동발달이 관찰되어진다. LNS에게서 현저하게 진단적인 특징으로 보여지는 운동심리적 행동인 self-mutilating 행위는 4살 이후에나 나타난다. LNS 아이들은 오히려 초기에 Rett's 증후근, 뇌성마비, 자폐, 다운증후근과 유사한 운동행위를 보인다. 그래서 LNS 아이들은 앞에 기술한 신경학적 장애로 오진을 받을 수가 있다. 오진으로 인해 초기에 적절한 치료를 받지 못한다면 LNS는 결과적으로 합병증(신장부전)과 self-mutilating 행위로 인하여 치명적일 수가 있다. 그러므로, 이 연구의 목적은 LNS 평가 동안 더 나은 진단을 하도록 하기 위하여 LNS와 관련된 기능부전에 대한 지식을 임상가들에게 제공하고자 함이었다. 연구 대상자는 10살인 2명의 쌍둥이 남아이었으며 실험은 뻗기 과제 수행(reaching task)시 움직임 특성을 보기 위하여 운동형상학적과 비디오 분석을 사용하였다. 기술통계로 분석 결과 움직임 시간과 단위가 증가됨을 보였고 사지의 분절적 움직임이 협응되지 않음을 보였다. ballistic과 jerky 움직임 양상은 dysmetric과 비긴장성 운동 행위에서 우세하였다. LNS은 추체로계 운동 장애 (과근긴장도나 저긴장도) 와 추체외로계의 운동 장애(dystonia와 choreoathetosis)의 혼합된 형태를 보였다. 결론으로 이 연구는 운동발달 장애를 가진 아이들을 치료하고자 할 때 임상가들한테 LNS 아이들의 움직임 장애의 다른 진단적 특징을 알아야 한다는 것을 제시하고자 한다.

• KSBB Journal
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• 제13권2호
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• pp.209-213
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• 1998

The characteristics of de-emulsification of pertroleum emulsion by Nocardia amarae were investigated. Insoluble medium containing n-hexadecane was more effective than soluble medium in de-emulsification of emulsion containing diesel and bunker C as the organic phase. Emulsion made by the addition of xanthan or bioemulsifier was de-emulsified by N. amarae, and longer culture age was effective. In low viscosity range, organic phase with longer carbon chain was more effective. The contact, angle between bacterial film and water droplet in air increased from 16 degree for 4 day culture age to 26 degree for 15 day. The contact angle between bacterial film and water droplet in kerosene, n-heyxane or n-hexadecane also increased to greater than 100 degree after 3 day culture age. The hydrophobicity of bactgerial film increased according to the culture age.

• Tribology and Lubricants
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• 제28권5호
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• pp.233-239
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• 2012

The engine of a large ship operates under wet conditions using a fuel such as bunker C oil, which includes sulfur and many impurities. A cylinder liner made of cast iron is very susceptible to damage such as scuffing on the surface. This scuffing can reliably be attributed to the destruction of the oil film and the corrosion wear caused by water and sulfur included in the fuel, along with abrasion impurities and poor lubricants. In this study, a reciprocating friction and wear test was carried out with a cast iron specimen, which was used to simulate an engine cylinder in a corrosive environment. Base-oil and stirred oil containing distilled water, NaCl solution, and dilute sulfuric acid were used as lubricants. The friction surface was analyzed using a microscope and EDAX, and the friction coefficient was measured using a load-cell under each experimental condition. We then attempted to investigate the damage to the cylinder liner using the results.

• 한국항만경제학회지
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• 제31권2호
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• pp.55-67
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• 2015

본 연구는 2000년 1월부터 2014년 10월까지의 월별자료를 이용하여 부정기선 해운업의 이윤과 대표적인 금융비용인 금리 간의 관계를 통계적으로 검정하고 그 영향을 분석하였다. 이를 위해 인과성 검정을 실시하여 변수 간의 인과관계를 확인하였고 공적분 검정을 통해 해운업의 이윤구조와 시장수익률 간에 장기균형관계가 존재함을 밝혔다. 이는 지속되는 해운불황의 원인이 외생적 수요로 야기된 선복량 과잉이며, 이에 대해 해운기업들은 수익과 비용의 리스크 관리 및 선박투자 위험의 최소화 전략을 강구 하여야 함을 의미한다.

• 센서학회지
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• 제31권4호
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• pp.266-270
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• 2022

Owing to the rising volume of seaborne trade, oil spills damage the marine environment for over 250 yearly. Thus, various analysis methods such as the Fourier-transform infrared (FTIR), Raman spectroscope, and gas chromatography are used to monitor oil spills at sea, but these methods are expensive. Recently, to reduce operational costs, an underwater fluorometer was adopted. However, this approach is not ideal for the remote sensing of oil spills because the device gets submerged in the sea. In this study, we have designed and developed a monitoring system that uses ultraviolet fluorescence to detect spilled oil or water from a distance, as well as proposed an analyzing method defining based on water Raman signal and QF535. Each fluorescence spectrum of water, oil (crude oil), and Bunker A was obtained using the system, and was calculated and analyzed from the spectrum individually. Based on the results of the analysis, we could successfully identity water and oil at a long distance.

• 국제학술발표논문집
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• The 5th International Conference on Construction Engineering and Project Management
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• pp.107-110
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• 2013

Recently, Korea parliament legislated the Low Carbon Green Growth Act (April, 2012) and approved a bill (May, 2012) to start carbon emission trading system in 2015. It means that for the first time, government would regulate the amounts of carbon emission in private entities, and private entities should attain predefined emission reduction goals by implementing clean development mechanism (CDM) project or buy the Certified Emission Reductions (CERs) from the trading market to avoid penalty. Under these circumstances, it is not easy for them to determine when or how to implement the CDM project because the governmental energy policies about the level of governmental subsidies, periods for free emission allocation, etc. are still under discussion and the future price of the CERs is quite uncertain. Thus, this study presents a real-option based model to assess the financial viability of the CDM project which switches bunker-C oil to liquefied natural gas (LNG). The proposed model is expected to assist private entities in establishing the investment strategy for CDM project under uncertain government energy policies.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.600-604
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• 2003

벙커 C유 1-5%가 주입되었을 경우에는 40.5%, 44.7%가 제거되었으며 본 유류분해균주는 A. calcoaceticus SEBCM-1로 명명하였다. pH 6과 pH 7에서 분해율이 약 73% 정도로 가장 높게 나타났으며 pH 4에서는 약 37% 정도가 미생물 분해에 의해 저감되는 것으로 나타났다. 본균은 다양한 pH조건에서도 생육이 가능하며 일정 수준의 분해력을 가지는 것으로 확인되었다. 본균은 비교적 넓은 온도 범위에서 왕성한 성장이 가능하며 분해가 가능할 것으로 판단된다. 본균의 영양분 조성 중 질소원의 주입량은 $0.5\;g/L{\sim}2\;g/L$ 범위에서 미생물 성장이 활발하였으며 0.1 g/L와 4 g/L로 주입했을 경우에는 미생물 성장이 크게 저하되는 것으로 관찰되었다.

• 한국대기환경학회지
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• 제5권1호
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• pp.68-78
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• 1989

The heavy metal of suspended particulates with human health has long been studied in environmental interest concerned. This study was intended to identify harmful heavy metals of the ambient air borne dusts which were related with the respirable sizes in the aerodynamics. Two sampling sites were selected comparatively; one was in the Shinchon area, which is the commercial district with heavy traffic and the other site was in the Bulgwang area which is residential area. The supended particulates were sampled by high volume air sample with 6 cascade impactor stages. The heavy metals in terms of As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, V and Zn were determined by stomic absorption spectrometry or inductively coupled plasma emission spectrometry. The samples weretaken bimothly for seven consecutive days from May 1987 to March 1988. The annual average concentration of the respirable suspended dust of which diameter is less than 10$\mum$ was 152.59 $\mug/m^3$ of the Shinchon air samples; the respirable dust was equivalent to approximately 85% of the total suspended particulates. The annual average concentration of the respirable suspended dust of the Bulgwang air samples was 112.56 $\mug/m^3$; that was approximately 86% of the total suspended particulates. The concentration of heavy metals was investigated in relation to the particle size. The concentration of Cr, Fe, Mn and V were tended to be much more in the coarse particles than in the fine particles. Cd and Pb in the fine particles were more than in the coarse particles. In the partial correlation coefficients; in the Shinchon area, high correlations among Fe, Se and Mn were determined; it is assumed that those sources would be originated from coal, gasolineand diesel. In Bulgwang area, would be high correlation among Fe, Se, Hg and Mn considered to be originated from coal, Bunker-C and heavy oil as well. From the above results, the hazardous heavy merals in air should be measured and controlled in originally their sources.

• 한국해양환경ㆍ에너지학회지
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• 제16권4호
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• pp.263-267
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• 2013

본 연구에서는 단일 파장의 빛이 기름과 해수로 구성된 혼합물을 투과하는 과정에서 굴절과 산란으로 인해 감쇠되는 빛의 세기를 평가하는 방법을 통해, 물위에 존재하는 기름의 두께를 측정할 수 있는 새로운 광학적 기름 탐지 방법론을 제시한다. 단일 파장의 광원으로 직진성이 좋고 단색광의 빛을 발산할 수 있는 레이저를 이용하였으며, 기름-물 혼합물을 투과한 빛의 세기를 정량적으로 측정하기 위해서 광 에너지를 전기 에너지로 변환할 수 있는 광전자소자인 포토다이오드를 선택하였다. 기름의 두께가 증가함에 따라서 투과된 빛의 크기가 점차적으로 감쇠되는 성질을 가진 광원의 파장 대역을 실험적으로 도출하기 위해서, 3개의 서로 다른 파장대역을 갖는 레이저를 이용하여 기름의 두께별로 투과된 광량을 측정하여 감쇠되는 경향을 비교하는 실험을 진행하였다. 해당 실험을 통해서 470 nm 파장을 갖는 청색 레이저를 이용하였을 경우, 기름의 두께가 증가함에 따라 투과된 광량의 세기가 점차적으로 감쇠되는 현상을 확인할 수 있었다. 본 연구에서 수행한 실험 결과를 통해서 레이저 광원에 대한 기름의 흡광 광도를 분석하는 방법으로 해수위에 존재하는 기름의 두께를 정량적으로 측정할 수 있는 가능성을 제시하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제33권7호
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• pp.1103-1112
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• 2020

Objective: To measure whether a microbial additive could effectively improve the fermentation quality of delayed-sealing (DS) silage, we studied the effects of inoculants of lactic acid bacteria (LAB) and cellulase enzyme on microbial populations, ensiling characteristics, and spoilage loss of DS silage of Napier grass in Africa. Methods: Quick-sealing (QS) and DS silages were prepared with and without LAB (Lactobacillus plantarum) inoculant, cellulase enzymes, and their combination. The QS material was directly chopped and packed into a bunker silo. The DS material was packed into the silo with a delay of 24 h from harvest. Results: In the QS silage, LAB was dominant in the microbial population and produced large amounts of lactic acid. When the silage was treated with LAB and cellulase, the fermentation quality was improved. In the DS silage, aerobic bacteria and yeasts were the dominant microbes and all the silages were of poor quality. The yeast and mold counts in the DS silage were high, and they increased rapidly during aerobic exposure. As a result, the DS silages spoiled faster than the QS silages upon aerobic exposure. Conclusion: DS results in poor silage fermentation and aerobic deterioration. The microbial additive improved QS silage fermentation but was not effective for DS silage.