• Tribology and Lubricants
• /
• 제14권4호
• /
• pp.108-113
• /
• 1998

In order to investigate the characteristics of top ring groove deposit formation in diesel engine, engine test and simulation test were performed. From component analysis of used oils sampled from actual running engines, soot content in engine oil was selected as a main parameter for evaluating oil degradation. Deposit formation is highly related to soot content in lubricating oils. And high soot content oil accelerates deposit formation even in low temperature region below 26$0^{\circ}C$. In low temperature region below 26$0^{\circ}C$, deposit formation rate is mainly affected by top ring groove temperature. However, in high temperature region above 26$0^{\circ}C$, deposit formation rate is affected by soot content as well as top ring groove temperature. Therefore, soot content as well as top ring groove temperature should be kept a certain level in order to prevent troubles due to carbon deposit formation.

• 한국대기환경학회지
• /
• 제31권4호
• /
• pp.368-377
• /
• 2015

Bunker C fuel oil is a high-viscosity oil obtained from petroleum distillation as a residue. The sulfur content of bunker C fuel oil is limited to 4.0% or even lower to protect the environment. Because bunker C fuel oil is burned in a furnace or boiler for the generation of heat or used in an engine for the generation of power, carbon dioxide is emitted as a result of combustion. The objective of this study is to investigate $CO_2$ emission characteristics of bunker C fuel oil by sulfur contents. Calorific values and carbon contents of the fuels were measured using the oxygen bomb calorimeter method and the CHN elemental analysis method, respectively. Sulfur and hydrogen contents, which were used to calculate the net calorific value, were also measured and then net calorific values and $CO_2$ emission factors were determined. The results showed that hydrogen content increases and carbon content decreases by reducing sulfur contents for bunker C fuel oil with sulfur contents less than 1.0%. For sulfur contents between 1.0% and 4.0%, carbon content increases as sulfur content decreases but there is no evident variation in hydrogen content. Net calorific value increases by reducing sulfur contents. $CO_2$ emission factor, which is calculated by dividing carbon content by net calorific value, decreases as sulfur content decreases for bunker C fuel oil with sulfur contents less than 1.0% but it showed relatively constant values for sulfur contents between 1.0% and 4.0%.

• 한국식품조리과학회지
• /
• 제13권1호
• /
• pp.40-46
• /
• 1997

약과의 제조조건에 따른 탈수량 및 유지 흡수량의 변화와 그때의 품질특성을 알아보고자 반죽을 냉장.냉동했을 경우 및 반죽의 크기, 튀김온도와 반죽횟수, 원료배합량을 달리하였을 경우의 탈수량 및 유지 흡수량의 변화, 관능적 특성 등을 조사하였다. 반죽을 냉장.냉동 했을 경우 control군과 탈수량, 유지 흡수량, 관능적 특성에 차이가 없었다. 반죽의 크기를 중, 대, 소로 하였을 경우 크기가 작을수록 탈수량과 유지 흡수량이 증가하였고, 크기가 중인 것이 전반적인 기호도에서 기호도가 가장 높았다. 튀김온도(12$0^{\circ}C$ 36분, 14$0^{\circ}C$ 16분, 16$0^{\circ}C$ 11분, 18$0^{\circ}C$ 7분)의 영향은 탈수량은 거의 차이가 없으나 유지 흡수량은 온도가 높을수록 감소하였다. 반죽횟수(30회, 200회)의 영향은 탈수량은 거의 차이가 없으나 유지 흡수량은 반죽횟수가 많을 때 감소하였다. 원료배합량에 따른 영향은 참기름, 꿀, 소주의 배합량이 증가하면 탈수량이 증가하였는데 소주의 경우 탈수 정도가 컸다. 유지 흡수량은 참기름의 경우는 첨가량의 증가에 따른 유의차가 없었고, 꿀의 경우는 첨가량이 증가하면 유지 흡수량이 유의적으로 증가하였으며, 소주의 경우는 첨가량이 증가하면 유지 흡수량이 유의적으로 감소하였다. 튀김온도, 반죽횟수, 원료배합비를 달리한 약과의 관능평가에서는 유지 흡수량이 많은 약과의 경우 광택, 연한 정도, 부서지는 정도, 기름 맛 등의 특성이 강하다고 평가하여 위의 제조조건이 약과의 유지 흡수량과 그에 따른 관능적 성상에 큰 영향을 미친다는 것을 알 수 있었다.

• Tribology and Lubricants
• /
• 제31권3호
• /
• pp.86-94
• /
• 2015

We perform lacquer formation experiments with various combinations of marine fuel oils and lubricant oils. We also investigate the influences of base number (BN) in lubricant oil and sulfur content in fuel oil. A dissolution test with 10% dilute sulfuric acid and pull-off force test are accomplished to distinguish whether the residual layers are lacquering or not. The lacquering layers are dissolved by dilute sulfuric acid and have a strong pull-off force. Moreover, the calcium content detected in the residual layers is compared by energy dispersive x-ray spectroscopy (EDS). More calcium is detected in the lacquer layers than in other residual layers. Distillate fuels containing low sulfur levels are more prone to lacquering when mixed with lubricant oil with a high BN. On the other hand, residual fuels with a high sulfur content do not form lacquer. We investigate the effect of mixture volume ratio. The mixture with higher fuel oil content is more prone to generate lacquer. These experiments indicate that a lubricant with an appropriate BN should be used to prevent lacquer forming on the surfaces such as cylinder liners depending on the sulfur content of fuel oil.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제15권6호
• /
• pp.107-113
• /
• 2010

This paper presents the prediction of shear strength of oil contaminated clay using fall cone test used to determine the liquid limit of soil. The penetration depth of fall cone is related to water content of soil. Laboratory vane shear can also be related to water content. To explore the relative correlation between penetration depth of fall cone and laboratory vane shear, both fall cone tests and laboratory vane shear test were carried out with water contents of soil. The developed empirical relationships in this studys showed that the shear strength is reduced to 3.9% with 1% increase of oil content. And, the lesser initial water content of contaminated clay, the more shear strength of contaminated clay is affected by oil content.

• 신재생에너지
• /
• 제19권4호
• /
• pp.27-34
• /
• 2023

In this study, microalgal oil was extracted from Nannochloropsis oceanica cultured in an open raceway pond and converted into biodiesel using a solid acid catalyst. Microalgal oil was extracted from two types of microalgae with and without nitrogen starvation using the KOH-solvent extraction method and the fatty acid content and oil extraction yield from each microalgae were compared. The fatty acid content of N. oceanica was 184.8 mg/g cell under basic conditions, and the oil content increased to 340.1 mg/g under nitrogen starvation conditions. Oil extraction yields were 90.8 and 95.4% in the first extraction, and increased to 97.5 and 98.8% after the second extraction. Microalgal oil extracted by KOH-solvent extraction was yellow in color and had reduced viscosity due to chlorophyll removal. In biodiesel conversion using the catalyst SO₄^2-/HZSM-5, solvent-extracted oil showed a FAME content of 4.8%, while KOH-solvent-extracted oil showed a FAME content of 90.4%. Solid acid catalyst application has been made easier by removal of chlorophyll from microalgal oil. The FAME content increased to 96.6% upon distillation, and the oxidation stability increased to 11.07 h with addition of rapeseed biodiesel and 1,000 ppm butylated hydroxyanisole.

• 한국작물학회지
• /
• 제44권2호
• /
• pp.159-162
• /
• 1999

This study was carried out to determine the optimum harvest date of unshelled immature peanuts and dried kernels from 60 to 120 days after flowering. Fresh pod yield of spanish-type variety, 'Shaedl-tangkong(SD)' reached a peak of 9,140kg/ ha at 70 (days after flowering(Aug. 13) while that of virginia-type variety, 'Daepoongtangkong(DP)' reached a peak of 8,820kg/ha at 90 days(Sept. 11) after flowering. SD and DP showed maximum fresh kernel yield of 6,090 and 6,470kg/ha at 90 days after flowering (Sept. 11), respectively, while dry kernel yield reached a peak of 3,300 and 3,720kg/ha at 110 days(Oct. 1), respectively. Oil content of SD and DP were the highest at 90 days and 100 days after flowering, respectively and the oil content of two varieties increased rapidly from 60 to 90 days. Tannin content of the seed hull of SD increased continuously until 110 days after flowering while that of DP maximized at 100 days. The tannin content of the two varieties increased rapidly from 60 to 100 days. Total sugar of SD and DP showed highest content at 60 days and 70 days after flowering, respectively and suger content decreased very rapidly until 80 days and after that sugar content kept nearly constant. Oil, tannin and total sugar content of spanish-type SD were higher than those of virginia-type DP.

• 한국축산식품학회지
• /
• 제35권1호
• /
• pp.130-136
• /
• 2015

This study was conducted to evaluate the quality properties of emulsion-type pork sausages when pork fat is replaced with vegetable oil mixtures during processing. Pork sausages were processed under six treatment conditions: T1 (20% pork fat), T2 (10% pork fat + 2% grape seed oil + 4% olive oil + 4% canola oil), T3 (4% grape seed oil + 16% canola oil), T4 (4% grape seed oil + 4% olive oil + 12% canola oil), T5 (4% grape seed oil + 8% olive oil + 8% canola oil), and T6 (4% grape seed oil + 12% olive oil + 4% canola oil). Proximate analysis showed significant (p<0.05) differences in the moisture, protein, and fat content among the emulsion-type pork sausages. Furthermore, replacement with vegetable oil mixtures significantly decreased the ash content (p<0.05), increased water-holding capacity in emulsion-type pork sausages. Also, cholesterol content in T6 was significantly lower than T2 (p<0.05). In the texture profile analysis, hardness and chewiness of emulsion-type pork sausages were significantly (p<0.05) decreased by vegetable oil mixtures replacement. On the contrary, cohesiveness and springiness in the T4 group were similar to those of group T1. The unsaturated fatty acid content in emulsion-type pork sausages was increased by vegetable oil mixtures replacement. Replacement of pork fat with mixed vegetable oils had no negative effects on the quality properties of emulsion-type pork sausages, and due to its reduced saturated fatty acid composition, the product had the quality characteristics of the healthy meat products desired by consumers.

• 한국식품영양학회지
• /
• 제27권3호
• /
• pp.339-347
• /
• 2014

This study investigated the classification of olive oils that are mainly distributed in Korea via imports. The fatty acid contents, degree of color, pigments, anti-oxidants, and sterol contents are analyzed on the different types of olive oil as follows: 10 kinds of extra virgin olive oil, 5 kinds of pure olive oil, and 5 kinds of refined olive-pomace oil. As a result of fatty acid analysis, the majority of oleic acid ($C_{18:1}$) and palmitic acid ($C_{16:0}$), and minority of linoleic acid ($C_{18:2}$) and stearic acid ($C_{18:0}$) were detected without any significant differences between the grades of olive oils. The UV spectrum is related to the ${\Delta}K$, and it is a part of the analysis factor for the purity and degree of degradation of the oil. Extra virgin olive oil had ${\Delta}K$ of almost 0, pure olive oil had 0.07~0.12, and refined olive-pomace oil had 0.1~0.13. These differed from extra virgin oil, and the pure or pomace oil ${\Delta}K$ had a confirmed distinct difference. The color degrees of chlorophyll with a low $L^*$ value and $(-)a^*$ (green) and carotenoid with $(+)b^*$ (yellow) were confirmed to have correlation between extra virgin and other olive oils. To compare chlorophyll and carotenoid as natural pigment in olive oils, 417 nm and the ratio of the absorbance at 480 nm (417/480) was calculated at 1.62 of extra virgin, 1.85 of pure olive oil, and 3.32 of refined olive-pomace oil. Therefore, it will be possible to distinguish when the extra virgin or pure olive oil are mixed with olive-pomace oil. The total amount of tocopherol, an anti-oxidant, were 19.06 in extra virgin, 10.91 in pure olive oil, and 27.88 in refined olive-pomace oil. The high content of tocopherol in pomace oil caused recovery of solvent extraction from olive pulp. Thus, extra virgin oil and pure olive oil were distinguished by olive-pomace oil. Polyphenol compounds in extra virgin olive oil measured high only in ferulic acid with 0.543 mg/kg, caffeic acid with 0.393 mg/kg, and other vanillic acid, vanillin, and p-coumaric acid had similar amount of 0.3 mg/kg. All grade of olive oils had the highest ${\beta}$-sitosterol content. Af (Authenticity factor) value were estimated with campesterol and stigmasterol content ratio (%). Af value was 19.2 in extra virgin olive oil, 17.1 in pure olive oil, 16.9 in refined olive-pomace oil, which were distinctive from sunflower oil with 3.7, corn oil with 2.4, and soybean oil with 2.0. It can provide important indicator of olive oil adulteration with other cheap vegetable oils. The results of this study can be used as a database for the classification of olive oil grade and distinguishing between the different types of oils.

• 생약학회지
• /
• 제8권2호
• /
• pp.69-72
• /
• 1977

The investigation is involved with the development of the new method of decoction preparation in order to prevent the loss of volatile oil from crude drugs. Volatile oil in crude drug containig volatile oil ranged from 1 to 2.2% in content. Volatile oil content in crude drung prescription which main component is a crude drug containing volatile oil was $0.11{\sim}0.39\;ml$. It was found that traditional method of decoction preparation has caused to lose almost all of the volatile oil. Application of method of Pharmacopoea (Kp II) for the preparation of decoction prevented the loss of volatile oil from one half to two-third of its content. The method of Pharmacopoea to which air condenser was attached could completely prevented the loss of volatile oil from the preparation.