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        검색결과 17

        8.
        2016.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        선박엔진은 잔사유를 에너지원으로 활용하여 운항할 수 있으며, 이를 활용한 선박에서 환경 규제와 경제성을 모두 만족시키는 다양한 방안들이 모색되고 있다. 그 중에 한 방안으로 연료 첨가제를 활용하는 기술이 있을 수 있다. 분산제와 연소촉진제는 잔사유활용 시 엔진의 연소특성 촉진에 기여할 것이라는 기대를 받고 있다. 따라서, 본 연구에서는 연소성 분석 장비(FIA/FCA)와 열 중량 분석 장비(TGA)를 활용하여 잔사유 연료첨가제가 혼합된 잔사유의 연소성을 분석하였다. 연소성 분석 장비(FIA/FCA)의 결과로는 연소에 의한 일의 총량을 분석하도록 분석법이 개발되었으며, 이 때문에 본 연구를 통하여 동일 장비를 활용하면서도 연소 효율을 간단하게 평가할 수 있는 방안을 제시하였다. 연소성 분석 결과인 ROHR 곡선으로부터, 단순한 삼각함수를 활용하여 연소특성을 예측할 수 있는 방안을 제시하였으며, 이 기법을 활용하여 기존의 압력 곡선과 유사한 결론을 도출할 수 있었다. 열 중량 분석(TGA)의 경우 연료유의 증발 특성에 민감하게 반응함을 확인하였고, 첨가제가 연료유 증발에 효과적으로 작용함을 확인하였다.
        4,000원
        9.
        2016.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper aims at presenting bunkering educational programs for LNG fueled ship taking into consideration existing similar education programs and safety systems at the international level in order to enhance both seafarers' and vessels' safety. Heavy fuel oil has typically been used as fuel of ship propulsion. The competitiveness of the fuel oil is recently getting weak in terms of cost and environmental aspects. Liquefied natural gas is introduced for ship propulsion in the maritime field as a new energy source replacing heavy fuel oil. In order to prepare for installation and operation of LNG fueled propulsion ship on board, International Maritime Organization has discussed this subject for about 10 years. As a result of the discussion on such ships in IMO, the International Code of Safety for Ships Using Gases or Other Low-Flash-Point Fuels entered into force on the year 2015. International organizations and several countries therefore drives actively entire researches and other businesses with a view to providing equipment and system of LNG bunkering. The systems are divided into ship-to-ship transfer, terminal / pipeline-to-ship transfer and truck-to-ship transfer. By adopting transfer system of LNG bunkering, many human resources will be needed in these areas on scene as well as on managing, operating, trading, finance, design of LNG bunkering industries. LNG bunkering is just in the beginning stage. Hence, this paper reviews and proposes professional educational programs of LNG bunkering in consideration of technical aspects of the safety system of LNG bunkering based on the types of bunkering systems.
        4,000원
        10.
        2011.11 구독 인증기관·개인회원 무료
        This purpose of this study was to analyze the nutritional composition about Auricularia spp., which has been used to Auricularia auricula-judae(black and brown) and Auricularia polytricha. First, the contents of total polyphenol and beta-glucan were analyzed. Subsequently, the contents of free sugars, amino acids and organic acids were analyzed by HPLC. In addition, the content of vitamin D from these strains was also measured and the D3 of this vitamin D was anlyzed. In conclusion, Auricularia spp. showed evident differences in the nutritional composition.
        12.
        2011.05 구독 인증기관·개인회원 무료
        This study was conducted to investigate the physiological activities of the ethanol extracts from 3 different strains of Hericium erinaceum. In addition, the β-glucan and polyphenol contents from these strains were also measured. As a result, total polyphenol contents were the highest in 1ho(39.07 mg%) strain and lowest in 2ho(17.59 mg%). β-glucan contents ranged from 17.69 to 18.26%. In the physiological activities, Inhibition effects of DPPH radical and Nitrite ranged from 3.29 to 9.6% and 1.52 to 5.27%, respectively. Inhibitory effects of nitric oxide production ranged from 23.72 to 33.47%. The highest inhibitory activities on α-amyloglucosidase activity and angiotensin I converting enzyme were 39.30% and 14.10%, respectively. Lastly, the cytotoxic activities of ethanol extracts from all the strains on A549, HT-29 and HeLa cell was shown the highest effect in A549 cell.
        13.
        2010.12 KCI 등재 구독 인증기관·개인회원 무료
        In this study, the anti-oxidant, anti-tumorigenic, anti-hypertensive, anti-thrombic, anti-diabetic, and anti- inflammatory properties of 18 different species of genus Pleurotus were investigated. In addition, the amino acid, β-glucan, and polyphenol contents were also measured. The β-glucan and polyphenol contents were the highest in Pleurotus cornucopiae var. citrinopileatus (yellow Pleurotus) of all species. The yellow Pleurotus also exhibited the highest physiological activity as assessed by the DPPH IC, Cytotoxic activity, ACE activity and so on. To confirm the mechanism for the physiological activity of the yellow Pleurotus, we performed further examinations within ICR mice. The yellow Pleurotus reduced glucose, triglyceride and total cholesterol levels in the ICR mice blood for 4 weeks after feeding, and also significantly lowered both GOT and GPT levels. Taken together, our data indicates the yellow pleurotus is a promising functional food ingredient.
        15.
        2006.09 구독 인증기관·개인회원 무료
        In present work, manufacturing technologies of titanium hydride powder were studied for recycling of titanium tuning chip and for this, attrition ball milling was carried out under H2 pressure of 0.5 MPa. Ti chips were completely transformed into TiH2 within several hundred seconds. Dehydrogenation process TiH2 powders is consist of two reactions: one is reaction of TiH2 to TiHx and the other decomposition of TiHx to Ti and H2. The former reaction shows relatively low activation energy and it is suggested that the reaction is caused by introduction of defects due to milling.
        16.
        2006.09 구독 인증기관·개인회원 무료
        Manufacturing technologies of micro parts were studied in nano grained Al-1.5mass%Mg alloy. During compressive test at 300 , the Al alloy showed stain softening ℃ phenomenon by grain boundary sliding regardless of strain rate. Micro spur gear with ten teeth (height of 200 μm and pitch of 250 μm) was fabricated with sound shape by micro forging. During micro forging, increase of applied stress induced by friction between material and die surface was effectively compensated by decrease of stress by strain softening behavior and as a result, flow stress increased only about 50 MPa more than that in compressive test.
        17.
        2015.02 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        이전 연구에서 포도 품종별 및 부위별 생리활성 물질을 분석한 결과 MBA 품종의 송이줄기 부위에서 transresveratrol 함량이 다른 품종에 비해 수십배 높았다. 이를 바탕으로 포도주 제조 시 버려지는 비가식 부위인 송이줄기 를 농도별로 첨가해 발효 중 발효액 및 포도주의 폴리페놀 함량을 조사하였다. 송이줄기 첨가량에 따른 발효액의 발효 중 적색도, 총안토시안 함량, 총폴리페놀 및 탄닌 함량은 발효후기로 갈수록 송이줄기 첨가에 따라 유의적으로 증가 하였고, 포도주에서도 같은 경향을 보였다. 반면 포도주의 휘발산 함량은 송이줄기 첨가량이 증가할수록 감소하는 경향을 보였다. 발효액 및 포도주의 폴리페놀 성분을 분석 한 결과 catechin(8.16∼23.08 mg/L)함량이 가장 높았으며 gallic acid(2.32∼3.28 mg/L), trans-resveratrol(1.38∼3.27 mg/L)및 ferulic acid(1.51∼1.59 mg/L) 순서로 함량이 높았 다. MBA 포도주의 항산화활성을 DPPH IC50로 측정한 결과 송이줄기 함량에 비례해 활성이 증가하였으며, 송이줄기 5% 첨가한 포도주(12 mg/L)는 ascorbic acid의 DPPH IC50 (67 mg/L)보다 낮은 농도에서 높은 항산화활성을 나타내었 다.