• 생명과학회지
• /
• 제12권6호
• /
• pp.745-751
• /
• 2002

원유 분해능이 강력한 해양균주를 얻고자 유류오염 지역으로부터 crude oil을 탄소원으로 이용하는 수십 종을 분리하였다. 분리된 균주중 원유분해능 및 biosurfactant 생성능이 우수한 균주를 선별하여, 형태학적, 생화학적 및 생리학적 특성을 조사한 후 Bacizzus sp. LSC11로 동정하였다. Bacillus sp. LSC11 균주 배양액의 표면장력은 최저 32mN/m까지 감소되었다. Biosurfactant의 CMC값은 0.0035% (w/v) 인 것으로 나타났다. Bacillus sp. LSC11가 생산하는 biosurfactant의 유화활성은 대두유에서 최대였으며, 원유에서도 높은 편이였다. 유화안정성은 합성계면활성제와 비슷하거나 우수하였다.

• 한국자동차공학회논문집
• /
• 제16권1호
• /
• pp.93-99
• /
• 2008

To improve the performance of plasma-DeNOx catalyst, a research on active system was performed experimentally. Two hydrocarbons, propane and diesel, were used as a reductant in this study. First, using propane, basic performances of plasma-DeNOx catalyst such as the effects of plasma and C/N ratio were measured at the various engine operating conditions. NOx conversion of catalyst was improved as plasma power or C/N ratio was increased. Next, diesel was injected in the exhaust gas flow as a reductant. The first test using diesel as a reductant is spray visualization in a high temperature flow and spray images were utilized for analysis of posterior test results. To evaluate the effect of an injection direction, it was compared with 6 installation methods of diesel injector due to THC concentrations at the inlet of plasma. From the results, injector was installed toward downstream direction below the pipe. Then, basic performances of plasma-DeNOx catalyst with various injection quantities were measured. As an injection quantity was increased, $NO_2$ conversion of plasma reactor was increased but NOx conversion of catalyst was nearly zero. This was because NOx conversion of catalyst had slowed as time goes by due to black particles which had been adhered to the catalyst.

• 한국대기환경학회지
• /
• 제20권1호
• /
• pp.129-138
• /
• 2004

Determination of some PAHs in ambient air at Ulsan have been carried out by collection of the components into n-hexane followed by synchronous spectrofluorimetric technique. 10 PAHs, such as acenaphthene (Ace), anthracene (Anth), benz[a]anthracene (BaA), benzo[b]fluoranthene (BbFt), benzo[k]fluoranthene (BkFt) benzo[a]pyrene (BaP), chrysene (Chry), phenanthrene (Phen), fluoranthene (Ft), perlyrene (Per), and pyrene (Pyr) in air samples were able to determine separately by synchronous spectrofluorimetry. Calibration curves for those components were linear for the concentration range of 0.2∼166ppb PAHs with the correlation factor of 0.9985∼0.9999. The predominant contribution was phenanthrene which was included 36.9∼85.1% to the overall level of the 10 PAHs in some areas. Also benzo[a]pyrene which was known to carcinogenicity was detected from 6.4 to 55.8ng/㎥, benzo[a]anthracene of some areas was contained from 21.9∼153ng/㎥.

• Tribology and Lubricants
• /
• 제9권2호
• /
• pp.16-21
• /
• 1993

Alkylbenzenes used as the synthetic lubricant base stocks were composed of the mixture of the various kinds of aromatic hydrocarbons. Their compositions have affected on the quality of synthetic alkylbenzene lubricants. Therefore, the rapid and accurate methods for the composit ional analysis are important. In this study, the compositions of the alkylbenzenes (Hv. LAB, FHv. LAB, Hv, BAB, DAB[HF], DAB[$AlCl_3$]) as synthetic base stocks have been investigated according to six average structural parameters(Tar, Nal, Asub, $\bar{n}$, nb, $T\alpha$) in the view of the molecular structures by $^{13}C-NMR$ spectroscopy. The experimental results of the oxidation $\varepsilon$ thermal stability tests have been related to the results of the molecular structural analysis.

• 생약학회지
• /
• 제5권1호
• /
• pp.1-6
• /
• 1974

Essential oils were separated by steam distillation from the roots of four species of the genus Valeriana and subjected to gas chromatography to screen monoterpenic hydrocarbons and related components. The amounts of the common components were contained in the following order: camphene, ${\alpha}-pinene$, bornyl-, myrtenyl isovalerate, myrtenylacetate and ${\beta}-pinene$, and small amounts of terpineol and terpinylacetate were also contained. Of the four species, the root of Valeriana fauriei $B_{RIQUET}$ var. dasycarpa $H_{ARA}$ contained the largest amounts of these components and the root of V. dageletiana $N_{AKAI}$ ex $M_{AEKAWA}$ the least. Since the root of V. dageletiana contained for less amounts of pinene, camphene and bornylacetate and none of dipentene and terpineol, this plant appears to be distinguished from the other three species.

• Journal of Mechanical Science and Technology
• /
• 제14권6호
• /
• pp.699-703
• /
• 2000

Experiments were carried out to investigate the characteristics of the hydrocarbon (HC) emissions and to reduce cold start hydrocarbons in gasoline engines. An HC adsorber was, used and it coated was by Pd/Rh catalyst with zeolite on a honeycomb monolith. The HCs were efficiently trapped at temperatures below $100^{\circ}C by physical adsorption. After adsorption, they were reduced gradually by the catalytic oxidation of Pd/Rh catalysts as the adsorber temperature increased above $100^{\circ}C. Increasing amounts of methane, ethylene and n-butane were emitted as the fuel-air mixture became richer and the engine speed decreased. As the temperature of adsorber increased, high-number carbons into low-number carbons. Thus, the C4 concentration decreased significantly during the first 30 seconds, and the C2 concentration increased continuously.

• 한국미생물·생명공학회지
• /
• 제27권6호
• /
• pp.452-457
• /
• 1999

Several bacterial strains utilizing crude oil as their sole carbon and energy sources were isolated from marine. One of the strains named KCL-1 showed the highest degradative activity for crude oil and the best growth rate. This strain was identified as a Klebsiella sp. based on the morphological, biochemical, and physiological characteristics. The optimum cultural conditions were as follows; $32^{\circ}C$~$37^{\circ}C$ for temperature and 7.0 for initial pH. Additionally, the optimal concentration of sodium chloride was 3.0%, indicating that this strain was derived from seawater. KCL-1 could use several kinds of n-alkane hydrocarbons from octadecane to hexacosane as a sole carbon source. The degradation of crude oil by KCL-1 was stimulated by addition of octadecane in the culture. The emulsifying activity by KCL-1 was highest after 3 days of cultivation under the condition of 3.0% sodium chloride, pH 7.0 and $37^{\circ}C$.

• 동력기계공학회지
• /
• 제3권2호
• /
• pp.20-25
• /
• 1999

Experiments were carried out to investigate the characteristics of formaldehyde emission from the small gasoline engine and its reduction technologies. Catalytic converters used are Pt/Rh, Pd/Rh, Pd/Pt, $62cell/cm^2$ monolith type. The measurement of formaldehyde was conducted by using the method of DNPH-GC. From the experimental results, formaldehyde emission increased in a lean mixture due to incomplete combustion of the hydrocarbons. The order of catalytic activity of formaldehyde oxidation was Pt/Rh > Pd/Rh > Pd/Pt. As the distance from the exhaust manifold to the inlet of the catalyst became far, in spite of lower catalyst temperature, formaldehyde concentration decreased because of the adsorption of formaldehyde.

• 한국환경독성학회:학술대회논문집
• /
• 한국환경독성학회 2003년도 추계국제학술대회
• /
• pp.31-32
• /
• 2003

A dynamic multimedia model with 2-dimensional spatial resolution, POPsME (Persistent Organic Pollutants in Multimedia Environments), was evaluated by comparing predicted relative concentrations with those measured. A total of 12 polycyclic aromatic hydrocarbons (PAHs) were tested (phenanthrene, anthracene, fluoranthene, pyrene, chrysene, benz (a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenz(a,h)anthracene, benzo(g,h,i)perylene, and indeno(1,2,3-c,d)pyrene). The concentrations were measured in air particulates, water (dissolved phase and suspended solids (ss)), soil, sediment, and leaves of Pinus koraiensis and Prunus serrulata at seven sites in the Seoul and neighboring area (150km x 150km), Korea.

• 한국미생물·생명공학회지
• /
• 제24권2호
• /
• pp.206-212
• /
• 1996

The strain producing bioemulsifier was isolated from soil samples. The isolated strain was identified as the genus Acinetobacter through its morphological, cultural and physiological characteristics. The highest emulsification activity and stability by Acinetobacter sp. BE-254 was observed after 5 days of cultivation in the culture medium containing n-hexadecane 4%, NaNO$_{3}$ 0.2%, KH$_{2}$PO$_{4}$ 0.01%, MgSO$_{4}$-7H$_{2}$O 0.01%, CaCl$_{2}$ 0.01%, and yeast extract 0.01%. The optimum pH and temperature for bioemulsifier production were pH 7.0 and 30$\circ$C, respectively. Furthermore the most of bioemulsifier was produced during the exponential growth phase, and this suggested that the bioemulsifier production was growth-associated. The bioemulsifier showed good emulsification activity on various emulsifying substrates such as hydrocarbons, edible oils, and petroleum fractions.