소형 선박용 디젤엔진에서 엔진초기화 세팅을 통한 연소성능 및 배기배출물 개선에 관한 연구

류영현,정균식,남정길 한국마린엔지니어링학회 2019 한국마린엔지니어링학회지 Vol.43 No.7

Tugboats that sail along a coast may experience poor engine combustion performance due to frequent entry and departure and frequent change of the ship’s speed. Decrease in combustion performance may cause an increase in specific fuel consumption and an increase in harmful exhaust emissions. Consequently, the engine maintenance cycle may be shortened, and its maintenance cost may increase. An initialization method that returns a small marine diesel engine to the state of a new engine needs to be employed to improve the combustion performance and reduce exhaust emissions. This method involves adjusting the matching of the exhaust turbocharger initialization, fuel injection timing, and fuel injection amount. By using this method, it is possible to optimize the engine by considering its future load range. This study measured and diagnosed the combustion condition of a small ship (tugboat) equipped with a 4-stroke diesel engine, which is currently operated. The methods to improve combustion performance and reduce exhaust emissions were then suggested. When the engine performance was improved through engine initialization, the maximum compression pressure increased by 34.9%, maximum explosion pressure by 24.7%, indicated mean effective pressure by 10.9%, engine output by 20.0%, and specific fuel consumption by 4.2%. Additionally, the exhaust gas temperature decreased by an average of 39.2 °C. The result of exhaust emission measurement revealed that particulate matter decreased by 55.8%, carbon dioxide known as greenhouse gas by 12.5%, carbon monoxide by 74.4%, and nitrogen oxide by 4.4%. 연안을 항해하는 소형선박(Tug boat)은 잦은 입·출항과 잦은 선속 변경으로 엔진의 연소성능이 저하될 수 있다. 연소성능의 저하는 연료 소비율 증가 및 유해 배기배출물 증가의 원인이 될 수 있다. 또한 그러한 이유로 엔진정비 주기가 짧아질 수 있어 엔진정비 비용이 증가될 수 있다. 소형 선박용 디젤엔진의 연소성능 및 배기배출물을 개선하기 위하여 제시된 방안으로 엔진을 신조시의 상태로 돌려보내는 초기화 방법으로 배기 과급기 초기화 매칭, 연료분사시기 및연료분사량을 조정하는 것이며, 이 방법을 이용하여 향후 엔진의 사용부하영역을 고려한 최적화도 가능하다. 본 연구에서는 현재 운항되고 있는 4행정 디젤엔진이 탑재된 소형선박(Tug boat)의 연소상태를 계측하여 진단하였으며, 연소성능개선 및 배기배출물 저감 방안을 제시하였다. 엔진초기화를 통해 엔진성능이 개선된 후에 최고압축압력은 34.9%, 최고폭발압력은 24.7%, 도시평균유효압력은 10.9%, 엔진 출력은 20.0% 증가하였으며, 연료소비율도 4.2% 향상되었다. 또한, 배기가스 온도는 평균 39.2 ℃ 감소하는 결과를 얻을 수 있었다. 배기배출물의 계측결과, Dust(PM)는 엔진성능 개선 후에55.8% 감소하였으며 GHG(Green House Gas)로 알려진 이산화탄소는 12.5%, 일산화탄소는 74.4% 감소하였고 질소산화물도 4.4% 감소되는 결과를 얻었다.

Alendronate-Polyurethane Films for Guided Bone Regeneration

류영현,최강호,오도현,최성욱 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.2

We synthesized biodegradable and hydrophilic polyurethane (PU) dispersion by a prepolymer method. Dimethylol propionic acid, which served as the polyol, provides carboxyl groups in PU and improves the hydrophilicity of the PU film. The carboxyl groups of the PU were utilized for the conjugation with alendronate (Alen) and the ionic cross-linking among PU polymers. Alen conjugation and ionic cross-linking both significantly reduced the water contact angle. The Alen-conjugated PU (Alen-PU) film showed a ductile property with high elongation at break. The ionic cross-linking of Alen-PU film resulted in the improvement of Young"s moduli and tensile strength. In addition, the biodegradation time of the PU-based films was increased due to the ionic cross-linking. The effect of Alen in PU film reduced proliferation and enhanced differentiation of pre-osteoblasts. We believed that the Alen-PU films have wide application potential in tissue engineering, especially for guided bone regeneration.

포도갈색무늬병 발병수준이 ‘켐벨얼리’ 유기포도의 광합성률에 미치는 영향

류영현,배수곤,연일권,김광섭,박상조,박준홍,박종호 한국유기농업학회 2016 韓國有機農業學會誌 Vol.24 No.4

Grape cultivar “Campbell Early” account for 70% of table grape in Korea and Leaf Spot Disease caused by Pseudocercospora vitis is one of a major disease in greenhouse and field grown area during late summer season in both of organic and conventional grape farm. Leaf spot disease can cause lowing of sugar content in fruit and vine growth and very difficult to control especially in organic field. Photosynthesis ability and chemical components are compared between leaf spot disease infected leaves with degree of necrotic area. With increase of disease necrotic area, CO2 differential value, water use efficiency and CO2 assimilation and respiration ratio are decreased proportionally and on the other hand, stomatal conductance value is not affected by disease necrotic area. Chlorophyll contents are also decreased by 50% in heavily infected leaves and imply decrease of chlorophyll contents is a major source of photosynthesis ability decline. With increase of disease necrotic area in leaves, total nitrogen and phosphate contents are decreased and on the other side, total carbon, potassium, calcium and magnesium contents are increased. From this research, we can infer that not only chemical control program is important in control of leaf spot disease but also fertilizing program is significant especially in organic agronomical control of fungal disease in grape cultivar “Campbell Early”.

팽이버섯 재배시 액체종균 사용 효과

류영현,윤영석,조우식,박선도,최부술,김종국 ( Young Hyun Ryu,Young Seok Yoon,Woo Sik Jo,Sun Do Park,Boo Sull Choi,Jong Kuk Kim ) 한국균학회 1998 韓國菌學會誌 Vol.26 No.1

글로벌 팬데믹 시대 위탁실습생들의 실습 만족도 분석

류영현,김화영 해양환경안전학회 2021 해양환경안전학회 학술발표대회 논문집 Vol.2021 No.06

소형선박의 미세먼지 저감에 관한 기초 조사

류영현 해양환경안전학회 2019 해양환경안전학회 학술발표대회 논문집 Vol.2019 No.11

중소형 선박수리지원 기반 구축 및 열교환기 세척설비 설계

류영현,임병주,남택근 해양환경안전학회 2018 해양환경안전학회 학술발표대회 논문집 Vol.2018 No.11

Xanthomonas aboricola pv. pruni에 의한 자두 검은점무늬병의 발생과 핵과류 과수 품종에 대한 병원성

류영현,이중환,권태영,김승한,김동근 한국식물병리학회 2012 식물병연구 Vol.18 No.1

Xanthomonas arboricola pv. pruni is the causal agent of bacterial black spot disease on some stone fruits, e.g. peach, plum and apricot. To evaluate pathogenicity of Xanthomonas arboricola pv. pruni strain from plum,inoculum of the isolated strain was spray inoculated to fruits and leaves of apricot, Japanese apricot and plum. Apricot and Japanese apricot showed severe black spot symptoms on fruits and shot hole symptoms on leaves. In case of apricot, about fifty percent of fruits did not grow and dropped by hypersensitive reaction to spray infection. Plum, cv. Formosa was very susceptible, showing severe black injury lesions on fruits and cankers on leaves and new twigs. On the other hand, plum cv. Daesukjosaeng, was highly resistant. Fruits of several plum cultivars such as Formosa and Chuhee were severely infected at natural infected orchards by X. arboricola pv. pruni. Where as those of Daesukjosaeng, Taeyang, Soldam and Hongrogen were moderately infected.

약제별 및 살포시기별 자두 검은점무늬병 방제효과

류영현,이중환,권태영,김승한,김동근 한국식물병리학회 2012 식물병연구 Vol.18 No.4

Xanthomonas arboricola pv. pruni causes black spot symptom on fruit of plum, resulting in yield loss by reduction of marketable fruit production. To develop an effective control program, some chemicals were sprayed in various scheme during dormant season and growing season after blooming period. Copper-based chemicals were sprayed during dormant season and antibiotic-based chemicals were sprayed during fruit growing season. Sprays of antibiotic-based chemicals in growing season was more effective than copper-based chemicals sprays in dormant season. Three applications of antibiotic-based chemicals in 10 days interval starting 10 days after full blooming controlled disease incidence as much as 93%, whereas applications of copper-based chemicals in dormant season controlled 26−42%. Antibiotic-based chemicals application starting 10 days after full blooming was more effective than starting 20 or 30 days after full blooming.

포도갈색무늬병 발병수준이 ‘켐벨얼리’ 유기포도의 광합성률에 미치는 영향

류영현,배수곤,연일권,김광섭,박상조,박준홍,박종호 한국유기농업학회 2016 韓國有機農業學會誌 Vol.24 No.4

Grape cultivar “Campbell Early” account for 70% of table grape in Korea and Leaf Spot Disease caused by Pseudocercospora vitis is one of a major disease in greenhouse and field grown area during late summer season in both of organic and conventional grape farm. Leaf spot disease can cause lowing of sugar content in fruit and vine growth and very difficult to control especially in organic field. Photosynthesis ability and chemical components are compared between leaf spot disease infected leaves with degree of necrotic area. With increase of disease necrotic area, CO2 differential value, water use efficiency and CO2 assimilation and respiration ratio are decreased proportionally and on the other hand, stomatal conductance value is not affected by disease necrotic area. Chlorophyll contents are also decreased by 50% in heavily infected leaves and imply decrease of chlorophyll contents is a major source of photosynthesis ability decline. With increase of disease necrotic area in leaves, total nitrogen and phosphate contents are decreased and on the other side, total carbon, potassium, calcium and magnesium contents are increased. From this research, we can infer that not only chemical control program is important in control of leaf spot disease but also fertilizing program is significant especially in organic agronomical control of fungal disease in grape cultivar “Campbell Early”.