• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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• pp.545-546
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• 2006

A problem of oil supply for a reciprocating compressor is very significant for an evaluation of reliability. Since a rotational motion of a crank shaft for the reciprocating compressor with small capacity is used for a power source of oil supply, a centrifugal force of the rotational shaft provides a stroke of oil inside the shaft like a centrifugal pump. The pumped oil rises following an inner wall and provided to a bearing passed through an oil supply hole at the side of the shaft for lubrication of the bearing. In this study, the amount of oil supply has been investigated by a numerical analysis for various conditions such as a shape of a groove, rpm of the compressor, and a shape of a flow channel. Also, a method of increasing oil supply for a low rpm has been studied so that the function can be improved for a variable condition.

• Journal of Biosystems Engineering
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• 제23권2호
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• pp.125-134
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• 1998

It seems possible, by use of vegetable oils, to solve the pollution problem caused by the exhaust gas from diesel-engine vehicles. Recently vegetable oils has received considerable attention as an alternative and clean energy source to the foreseeable depletion of world oil supplies. The objective of this study is to experimentally investigate the characteristics of exhaust emissions of a small diesel engine using light oil, rice-bran oil, heated rice-bran oil, rice-bran oil treated with ultrasonic energy. SO$_2$ emission from the pure and the treated rice-bran oils was not detected at speeds hgher than 1,800 rpm while that from the light oil was detected at all the speeds at 4/4 load. NOx emission form these vegetable oils was generally higher compared to that from the light oil for most of the test conditions. tendency opposite to that of NOx emission. The data obtained in this experiment may be applicable for the desist of small diesel engine using the alternative fuels.

• 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.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2006년도 춘계학술발표회
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• pp.85-92
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• 2006

모든 원유(crude oil) 와 연료유(refined petroleum) 는 서로 구별되는 개별 탄화수소 특성을 가지고 있다. 원유의 경우 산지별로 고유한 특성을 지니고 있으며, 연료유의 경우 같은 유종이라 할지라도 그 원료가 되는 원유의 특성, 또는 생산공정, 생산시기 등에서 차이점이 발생하고 생산시기가 동일한 통일유종의 기름이더라도 선박의 연료탱크 내에 남아있는 잔류물과의 혼합 등에 의해 구별될 수 있는 특징을 가지게 된다. 유지문기법(oil fingerprint method)은 이러한 특성을 이용하여 해상유출유의 오염원을 밝히기 위한 감식 분석기법을 말한다. 현재의 유용한 유지문기법으로는 기체크로마토그래피 (GC)를 이용한 포화탄화수소류 방향족탄화수소류 황화합물 패턴분석방법과 적외선분광광도계(IR)를 이용한 적외선스펙트럼 측정방법 그리고 형광분광광도계(FL)를 이용한 방향족탄화수소류 스펙트럽분석방법 둥이 있으며 GC/MS를 이용한 EICs(Extracted Ion Chromatograms) 패턴분석방법이 있다.

• Advances in Energy Research
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• 제1권2호
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• pp.147-163
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• 2013

The world faces several issues of energy crisis and environmental deterioration due to over-dependence on single source of which is fossil fuel. Though, fuel is needed as ingredients for industrial development and growth of any country, however the fossil fuel which is a major source of energy for this purpose has always been terrifying thus the need for alternative and renewable energy sources. The search for alternative energy sources resulted into the acceptance of a biofuel as a reliable alternative energy source. This work presents the study of optimization of process of transesterification of vegetable oil to biodiesel using NaOH as catalyst. A $2^4$ factorial design method was employed to investigate the influence of ratio of oil to methanol, temperature, NaOH concentration, and transesterification time on the yield of biodiesel from vegetable oil. Low and high levels of the key factors considered were 4:1 and 6:1 mole ratio, 30 and $60^{\circ}C$ temperatures, 0.5 and 1.0 wt% catalyst concentration, and 30 and 60 min reaction time. Results obtained revealed that oil to methanol molar ratio of 6:1, tranesetrification temperature of $60^{\circ}C$, catalyst concentration of 1.0wt % and reaction time of 30 min are the best operating conditions for the optimum yield of biofuel from vegetable oil, with optimum yield of 95.8%. Results obtained on the characterizzation of the produced biodiesel indicate that the specific gravity, cloud point, flash point, sulphur content, viscosity, diesel index, centane number, acid value, free glycerine, total glycerine and total recovery are 0.8899, 4, 13, 0.0087%, 4.83, 25, 54.6. 0.228mgKOH/g, 0.018, 0.23% and 96% respectively. Results also indicate that the qualities of the biodiesel tested for are in conformity with the set standard. A model equation was developed based on the results obtained using a statistical tool. Analysis of variance (ANOVA) of data shows that mole ratio of ground nut oil to methanol and transesterification time have the most pronounced effect on the biodiesel yield with contributions of 55.06% and 9.22% respectively. It can be inferred from the results various conducted that vegetable oil locally produced from groundnut oil can be utilized as a feedstock for biodiesel production.

• Tribology and Lubricants
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• 제24권1호
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• pp.7-13
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• 2008

In this work, a simple and low cost sensor technique is proposed to test oil color in real time using in-line sensor. It is presented to use a ratio of intensity in red wavelength range to intensities of green and blue wavelength ranges (defined as a 'chromatic ratio') in order to estimate the oil color change. The proposed sensor technique is realized by irradiating a white LED as light source and a RGB color sensor as photoreceiver, and the chromatic ratio of various types of used oils are measured. The results show that chromatic ratio generally reflects chemical deterioration of oil, including oil oxidation and thermal degradation. It is concluded that the proposed sensor could be used for an effective oil monitoring technology.

• Ocean and Polar Research
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• 제40권4호
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• pp.271-280
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• 2018

The purpose of this study is to examine the causal relationship among oil consumption, oil-tanker accidents, and economic growth, and to derive policy implications from the results. Therefore, this paper attempts to analyze the short term, long term, and strong causality factors pertaining to the relationship between oil consumption, oil-tanker accidents, and economic growth in Korea using time-series techniques and annual data for the 1984-2016 period. Tests for unit roots, co-integration, and Granger-causality based on an error-correction model are presented. The results show that bidirectional causality exists between oil consumption and oil-tanker accidents, between economic growth and oil consumption, and between oil-tanker accidents and economic growth. The study shows that oil was used as a core energy source during the rapid economic growth of Korea in the past, and that this caused the number of oil-tanker accidents to rise as oil consumption increased.

• 한국환경과학회지
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• 제19권12호
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• pp.1421-1430
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• 2010

Polycyclic aromatic hydrocarbons (PAHs) were investigated in seawater and marine sediment from Anmyundo coastal area after oil spill. The concentrations of total PAHs in surface and bottom of seawater at August were 31.1 to 142.6 ng/L and 5.9 to 50.9 ng/L in August and November, respectively. The concentrations of PAHs in sediment were 21.0 to 102.9 ng/g D.W. and 32.3 to 57.4 ng/g D.W. in August and November, respectively. PAHs concentrations in seawater and sediment in August were higher than those in November about 2.5 and 1.4 times, respectively. Diagnostic ratio (PhA/AnT and FluA/Pyr) were investigated to identify source of PAHs in seawater and sediment. The PAHs in seawater originated from pyrolytic source and those in sediment originated from pyrolytic and petrogenic source. The glass, wood and coal origin was higher than petroleum origin on the combustion origin of PAHs in seawater and sediment. The seawater of Anmyundo costal area recovered from oil spill, but the sediments of that were weakly influenced by oil spill until now. Because this area is developed many fishing grounds, demanded Long Term Environmental Monitoring Program (LTEMP). The concentrations of PAHs on depth of sediments were investigated at station 8 and 10. The concentrations of PAHs were decreased with increasing depth.

• Animal Bioscience
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• 제36권7호
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• pp.1044-1058
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• 2023

Objective: The objective of this study was to characterize physiochemical and nutrient profiles of feedstock and co-products from canola bio-oil processing that were impacted by source origin. The feedstocks and co-products (mash, pellet) were randomly collected from five different bio-oil processing plants with five different batches of samples in each bio-processing plant in Canada (CA) and China (CH). Methods: The detailed chemical composition, energy profile, total digestible nutrient (TDN), protein and carbohydrate subfractions, and their degradation and digestion (CNCPS6.5) were determined. Results: The results showed that TDN_1x was similar in meals between CA and CH. CH meals and feedstock had higher, truly digestible crude protein (tdCP) and neutral detergent fiber (tdNDF) than CA while CA had higher truly digestible non-fiber carbohydrate (tdNFC). The metabolizable energy (ME_3x), net energy (NE_Lp3x, NE_m3x, and NE_g3x) were similar in meals between CA and CH. No differences were observed in energy profile of seeds between CA and CH. The protein and carbohydrate subfractions of seeds within CH were similar. The results also showed that pelleting of meals affected protein sub-fractionation of CA meals, except rapidly degradable fractions (PB1), rumen degradable (RDPB1) and undegrdable PB1 (RUPB1), and intestinal digestible PB1 (DIGPB1). Canola meals were different in the soluble (PA2) and slowly degradable fractions (PB2) between CA and CH. The carbohydrate fractions of intermediately degradable fraction (CB2), slowly degradable fraction (CB3), and undegradable fraction (CC) were different among CH meals. CH presented higher soluble carbohydrate (CA4) and lower CB2, and CC than CA meals. Conclusion: The results indicated that although the seeds were similar within and between CA and CH, either oil-extraction process or meal pelleting seemed to have generated significantly different aspects in physiochemical and nutrient profiles in the meals. Nutritionists and producers need to regularly check nutritional value of meal mash and pellets for precision feeding.

• 한국수산과학회지
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• 제47권4호
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• pp.390-398
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• 2014

We conducted an 8-week feeding trial to evaluate dietary lipid sources on the growth performance and body composition of juvenile river puffer fish Takifugu obscurus. Nine experimental diets were formulated with fishmeal as the major protein ingredients, providing 50% crude protein. The experimental diets contained either beef fallow (BF), soybean oil (SO), rapeseed oil (RO), or linseed oil (LO). Each of these diets was then supplemented or not with 0.5% n-3 HUFA (BFH, SOH, ROH, and LOH), resulting in a total of eight experimental diets. The control diet contained fish oil (FO) as the lipid source. Fish averaging $10.3{\pm}0.03g$ were fed the experimental diets in randomly selected triplicate groups for 8 weeks. Weight gain and feeding efficiency of fish fed the FO and SOH diets were significantly higher than those of fish fed BF or RO (P<0.05), but these diets did not differ significantly from the other diets. The protein efficiency ratio of fish fed the SOH diet was significantly higher than that of fish fed the BF, SO, or RO diets (P<0.05), but these were not significantly different from the other diets. The specific growth rate of fish fed the FO and SOH diets was significantly higher than that of fish fed the BF diet (P<0.05). Whole body DHA and n-3 HUFA contents of fish fed the FO diet were significantly higher than those of fish fed the SO, RO, or LO diets (P<0.05), but were not significantly different from the other diets. These results indicate that soybean oil and linseed oil could replace up to 100% of fish oil in the diet containing 60% fishmeal for river puffer fish.