• 한국자동차공학회논문집
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• 제19권3호
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• pp.106-112
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• 2011

This study is to investigate the effect of an aromatic content in high cetane number (CN) fuels on exhaust emissions under low temperature diesel combustion, which expands the previous research about an aromatic content in low CN fuels. A 1.9L common rail direct injection diesel engine was run at 1500 rpm 2.6 bar BMEP with four fuel sets: an aromatic content of 20% (A20) or 45% (A45) with CN30, i.e. low CN fuels, and CN55, i.e. high CN fuels. Given experimental conditions, the trend of exhaust emissions in high CN fuels was inconsistent with that of low CN fuels which all produced nearly zero smoke but higher NOx for the high aromatic fuel (CN30-A45). For high CN fuels, however, the low aromatic fuel (CN55-A20) produced lower smoke than the high one (CN55-A45) while NOx was similar to each other. The cause of this discrepancy between high CN and low CN fuels is unclear whether it comes from that CN may be a dominant factor to govern exhaust emissions rather than an aromatic content or that the actual CN value of CN55-A45 is lower than CN55-A20. More decent fuel matrix should be prepared and further experiments are needed to confirm it.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1998년도 제28회 추계학술대회
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• pp.181-189
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• 1998

In order to investigate the effect of base oil composition on the electronic insulating oil's performances, an experimental study has been conducted using different oils. Owing to their properties, like lower pour point and gas absorbing, naphthenic base oils are used more often than paraffmic base oils for the electronic insulating oil application. Naphthenic and paraffinic base oils are significantly different in their aromatic hydrocarbon content. In this paper, PXE(para xylyl ethane), LAB(linear alkylbenzene), C13 aromatic hydrocarbon mixture and C17 aromatic hydrocarbon mixture are investigated regarding their influence on insulating oil's performances. According to present study, breakdown voltage decreased with increasing aromatic lydrocarbon content in a deep dewaxed paraffmic base oil. However, any changing in the dissipation factor was not recognizable at small treated level. Furthermore, the volume resistance was not influenced by aromatic hydrocarbon content. The gassing tendency was found as a highly sensible property, changing with treating aromatic hydrocarbons. The higher benzene ring content in the hydrocarbon, the better gassing tendency.

• 한국응용과학기술학회지
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• 제31권4호
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• pp.549-561
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• 2014

미국과 유럽 등지에서는 자동차용 경유의 방향족 함량이 대기 환경오염의 원인물질로 추정하고 있다. 경유의 총 방향족 및 다고리 방향족 함량 감소가 환경 유해배출가스 HC, NOx, PM 등을 감소시키기 때문이다. 국내에서도 급변하고 있는 차량기술 및 연료품질간의 상관성 규명이 필요한 실정이다. 따라서 본 연구에서는 국내 실정에 맞는 차량과 연료간의 상호작용에 의하여 발생될 수 있는 환경적 영향평가를 진행하였으며 대상으로는 2.2L급 국내 대표 차량 2종(DPF 유 무)과 국내 정제기술로 생산된 5종의 연료를 통하여 경유의 방향족 함량에 따른 배출가스 특성을 분석하였다.

• 한국연초학회지
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• 제20권1호
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• pp.33-39
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• 1998

Survival, growth and reproduction of the cigarette beetle, Lasiodema sewicome F., were studied on flue-cured (NC82), air-cured (Br.21), aromatic (Izmir) tobacco and artificial diet (wheat feed 95% + yeast 5%). Cigarette beetle adults occurred from first generation in the flue-cured and aromatic tobacco, but no adults emerged in air-cured tobacco after the 2nd generations. The head capsule widths of larvae of the cigarette beetles L sewicome F.1 reared on different diets at 2$0^{\circ}C$, $25^{\circ}C$ and 3$0^{\circ}C$ were measured. The head capsule development was slower at 2$0^{\circ}C$ on the same diets than $25^{\circ}C$ and 3$0^{\circ}C$, and slower in the flue-cured and aromatic tobacco than the artificial diet at 2$0^{\circ}C$ and 2S$^{\circ}C$, At $25^{\circ}C$ the larval head capsule developed more rapidly in the aromatic tobacco than the flue-cured tobacco. However, no larval head development was noticed in the air-cured tobacco. The correlation between population densities of cigarette beetle,1 sewicome F., and sugar content of tobacco leaves was positive, but negative in nicotine contents. The regression between densities and sugar content was Y : 22.79 X + 57.29 (r=0.891**), and between nicotine content was Y : -141.31X + 321.40(r=-0.917**).

• 한국약용작물학회지
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• 제6권4호
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• pp.299-304
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• 1998

본 연구는 방향성 약용작물인 삼백초, 구릿대, 천궁의 향기 성분 조성과 식물정유 함량을 조사하여 향료업과 관련된 다양한 식품첨가물 또는 향원 가능성을 알아보기 위하여 몇가지 실험한 결과를 요약하면 아래와 같다. 1. 삼백초의 향기성분은 22종으로 1,6-octadien-3-ol, 1, 3-benzodioxole, myristicin, ${\alpha}-cadinol$, patchouene였고 조성은 alcohol류 6종, ester류 1종, ether류 2종, hydrocarbon류 11종, ketone류 1종, fatty acid류 1종이었다. 2. 구릿대의 향기성분은 14종으로 주요 성분은 3-carene, ${\beta}-caryophyllene$, ${\beta}-cubebene$, butylated hydroxytoluene, caryophyllene oxide, piperonal이었고 조성은 alcohol류 1종, ester류 1종, ether류 1종, hydrocarbon류 10종, aldehyde류 1종이었다. 3. 천궁의 향기성분은 16종으로 주요성분은 aristolene, benzocycloheptene, ylangene, valencene, ${\beta}-cedrene$, satene, and menthofuran이었고 조성은 alcohol류 2종, ether류 1종, hydrocarbon류 12종. furan류 1종이었다. 4. 삼백초, 구릿대 및 천궁 잎의 식물정유 함량은 각각 0.987%, 0.452%, 0.439%로 삼백초가 가장 높은 함량을 보였다.

• 공업화학
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• 제20권3호
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• pp.258-265
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• 2009

Poly(tetramethylene glycol) (PTMG, Mw = 2000), dicyclohexylmethane-4,4'-diisocyanate $(H_{12}-MDI)$와 4,4'-diphenylmethane diisocyanate (MDI)의 이소시아네이트 혼합물, 그리고 음이온기로서 dimethylol propionic acid (DMPA)를 사용하여 프리폴리머 혼합법으로 음이온성 폴리우레탄 분산체(PUD)를 합성하였다. 프리폴리머의 중화제로서는 triethylamine (TEA)을, 그리고 프리폴리머의 가지연장제로는 ethylene diamine (EDA)를 사용하였다. DMPA의 몰비율과 혼합이소시아네이트에서 방향족 이소시아네이트의 함양이 PUD의 입자크기와 점도변화에 미치는 영향을 연구하였다. 그리고 또한 DMPA의 몰비율과 방향족 이소시아네이트 함양 변화에 따른 PUD 도막의 기계적 성질과 열적 성질에 대해서도 논의하였다. DMPA의 몰비율이 증가할수록 음이온성 PUD의 입자크기와 점도가 감소하였으나, 동일한 DMPA 함량에서는 이소시아네이트 혼합물 중 방향족 이소시아네이트의 함량이 증가 할수록 입자의 크기와 점도가 증가하는 경향을 나타냈다. 혼합 이소시아네이트의 몰비율이 일정할 때 PUD 도막의 인장강도는 DMPA의 함량이 증가함에 따라 증가하였으나, 신장율은 감소하였다. PUD 도막의 열분해 온도에 있어서, DMPA 함량에 대한 영향은 크게 나타났으나, 방향족 이소시아네이트 함양의 영향은 DMPA 함량이 낮은 조건에서는 상대적으로 크지 않았다.

• 한국자원식물학회지
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• 제11권3호
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• pp.279-282
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• 1998

This expriment was carried out to get basic information on composition and yield of aromatic constituents in leaves of four medicinal plants, Angelica tenuissima, Chrysanthemum zawadskii. ssp. latilobum, Artemisia iwayomogi and Artemisia capillaris. Volatile aromatic constituents, 28 compounds in Angelica tenuissima were identified and 19 compounds were indentified in Chrysanthemum zawadskii ssp. latilobum. Volatile aromatic constituents, 23 compounds in Artemisia iwayomogi and Artemisia capillaris were identified. Major volatile aromatic consitiuents analyzed by GC/MS in four plants were $\alpha$-pinene, camphene, sabinene, cis-2-hexanol, and camphor etc. Content of essential oils in Angelica tenuissima, Chrysanthemum zawadskii ssp. latilobum, Artemisia iwayomogi and Artemisia capillaris were 0.014, 0.275, 0.785, and 0.452%, respectively. As a result, it was suggested that a medicinal plant, Artemisia iwayomogi, was worthy of using as a useful material of perfume.

• 한국패류학회지
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• 제26권2호
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• pp.107-114
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• 2010

To evaluate the culture conditions in oyster-farming waters, chemical and biological measurements were made in seawater and oysters from six bays around Tongyeong in November and December 2003. Nutrient levels in the seawater were higher in the western area than in the eastern area, in contrast to particulate organic matter and dissolved oxygen levels. The mean total polycyclic aromatic hydrocarbon ({\sum}PAH) content of the oysters was 194.5-375.9 ng/g dry weight, with four-ring compounds constituting 34.1%-79.6% of PAH. Despite wide temporal variations, a "western > eastern" spatial distribution of PAH was apparent. These low concentrations of PAHs indicate that Tongyeong waters are pristine in terms of PAH contamination. Among the hemocytic biomarkers, only lysosomal activity was significantly reduced in Hansan-Goje Bay, but did not correlate closely with PAH content. This finding indicates that the impact of PAH on cultured oysters is negligible around Tongyeong waters.

• Fibers and Polymers
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• 제1권2호
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• pp.111-115
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• 2000

The effects of nitrile group substitution onto aromatic polyamide backbone on the gas permeability and permselectivity of the polymers are examined. The gas permeability of aromatic polyamides increase with increasing the content of nitrile group substitution, whereas the permselectivity decreases with increasing the nitrile group contents. The effects of chain linrearity on the permeability and permselectivity are also examined. The non-linearity of the polymers increases the permeability. These behaviors are interpreted in terms of chain packing and crystallinity of the aromatic polyamides.

• 한국식품과학회지
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• 제23권3호
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• pp.276-279
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• 1991

카레분의 향미향상과 숙성효과를 높이기 위하여 숙성전의 카레분에 대하여 미분쇄와 배전처리를 행한 후 GC를 사용하여 각각의 향미성분을 분리 동정하였다. 카레분의 주요 휘발성 향미성분은 eugenol, cuminaldehyde, myristicin, anethole, eugenolacetate, cinnamaldehyde, linalool, limonene, p-cymene, ${\gamma}-terinene$ 및 기타 미확인 물질 등으로 나타났으며, 미분쇄시간이 10분 이내일 때에는 저비점 화합물이 증가하였으나 10분 이후부터는 고비점 화합물이 증가했다. 또한, 배전 처리시 처리온도의 상승에 따라 저비점 화합물은 감소하였고, 고비점 화합물은 증가하는 경향을 보였다.