• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.6
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• pp.112-118
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• 2001

In this study the leakage current measurement method based on a porous ceramic is applied to check the conductive substance caused by the ionized particles. By using engine and chassis dynamometer and an experiment vehicle, in which the hydrocarbon sensor (HC sensor) was exposed to the exhaust gas to create the electrical signal, the HC sensor in the exhaust line checked the conductive ions in emission gas. Generally the output electrical signal of HC sensor is followed with amount of hydrocarbon in the experiments in cold start and operation. By combining the electrical signal, a measure of conductivity of exhaust gas with hydrocarbon can be provided by OBD (On Board Diagnosis) II and EMS (Engine Management System).

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.2
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• pp.1-10
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• 2001

In order to reduce hydrocarbon emissions of spark ignition engine, it is important not only to improve catalyst conversion efficiency but also to reduce direct engine out hydrocarbon emissions, during cold starting and warm up process. Tjerefore many researchers have been attracted to develop an early fuel evaporator (EFE) by introducing a ceramic heater for a solution of engine out hydrocarbon emissions in SI engine. But, the performance of the EFE in MPI engine to reduce the exhaust emissions and to improve the cold startability has nat been clarified yet. The purpose of this study is to evaluate the feasibility of a glow plug for EFE.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.12
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• pp.1017-1024
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• 2006

In this work, pool boiling heat transfer coefficients (HTCs) of five hydrocarbon refrigerants of propylene, propane, isobutane, butane and dimethylether (DME) were measured at the liquid temperature of $7^{\circ}C$ on a 26 fpi low fin tube, Turbo-B, and Thermoexcel-E tubes. All data were taken from 80 to $10kW/m^2$ in the decreasing order of heat flux. The data of hydrocarbon refrigerants showed a typical trend that nucleate boiling HTCs obtained on enhanced tubes also increase with the vapor pressure. Fluids with lower reduced pressure such as DME, isobutane, and butane took more advantage of the heat transfer enhancement mechanism of enhanced tubes than those enhancement ratios of $2.3\sim9.4$ among the tubes tested due to its sub-channels and re-entrant cavities.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.340-345
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• 2008

Liquid hydrocarbon fuels are gathering increasing attention as candidates for a scramjet engine fuel. Experimental researches on supersonic combustion of kerosene have been conducted in model scramjet combustors. Through these works, understanding of combustion characteristics of kerosene have been revealed on some level, and so we decided to work on other kinds of liquid hydrocarbon fuels in order to explore effects of fuel properties on supersonic combustion performances, especially self-ignition and flame-holding. In addition, comparing the results of new fuels with kerosene, the relationship between fuel properties and supersonic combustion characteristics was discussed.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.55.1-55.1
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• 2019

Recently, temporal variations of the 3-micron emissions of methane and ethane have been detected in the auroral regions of Jupiter observed from Gemini North (Kim et al. 2019, in preparation). These temporal variations of 3-micron hydrocarbon emissions in the auroral regions can be caused by the following phenomena: temporal variations of temperatures, mixing ratios, auroral particle bombardments and Joule heatings, and the combinations of these. Although we are not able to quantitatively determine the cause of the temporal variations at this moment, we will present the following quantitative discussions: thermal influences on the 3-micron emissions, global mixing ratio distributions of the hydrocarbon molecules, and energy distributions of auroral particles penetrating the hydrocarbon layers. We will also present a possible correlation between the temporal variations of the 3-micron emissions and solar wind activities.

• KSBB Journal
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• v.13 no.5
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• pp.606-614
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• 1998

In this study, biodegradation rate of Arabian light crude oil by mixed cultures of selected petroleum-degraders was determined. Their modes of hydrocarbon uptake were then observed to determine whether there are differences in biodegradation rate by the mixed cultures. By the mixed cultures of petroleum-degraders having same modes of hydrocarbon uptake, such as strain US1 and K1 (using pseudo-solubilized hydrocarbons by a biosurfactants), K2-2 and P1(using hydrocarbons by direct contact), CL 180 and IC-10 (mixed type of uptake modes), the biodegradation rates of aliphatics in the crude oil were increased more than those by their pure cultures, about 40%, 25% and 20%, respectively. Biodegradation rate of strain KH3-2 (using only water- dissolved hydrocarbons) was increased by mixed cultures with strain K1, CL180 or IC-10 possessing high emulsifying activity. However, the biodegradation rate of the crude oil was decreased about 20%-40% by the mixed cultures of petroleum-degraders having different mode of hydrocarbon uptake, such as addition of strain US1 or K1 in the cultures of K2-2 or P1. Biosurfactants produced by US1 or K1 seems to enhance the emulsification of crude oil in aqueous phase but inhibit the attachment of K2-2 or P1 to crude oil. As same phenomena, the addition to Triton X-100 into the culture of strain US1, K1, CL180, IC-10 or KH3-2 increased the biodegradation rate, but the addition in the culture of strain K2-2 or P1 decreased the biodegradation rate. The mixed culture made of CL180, IC-10 and KH3-2 degraded 61.5% of aliphatics and 69% of aromatics in 3% (v/v) of Arabian light crude oil added.

• Journal of Microbiology and Biotechnology
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• v.26 no.7
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• pp.1320-1332
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• 2016

Light hydrocarbons accumulated in subsurface soil by long-term microseepage could favor the anomalous growth of indigenous hydrocarbon-oxidizing microorganisms, which could be crucial indicators of underlying petroleum reservoirs. Here, Illumina MiSeq sequencing of the 16S rRNA gene was conducted to determine the bacterial community structures in soil samples collected from three typical oil and gas fields at different locations in China. Incubation with n-butane at the laboratory scale was performed to confirm the presence of "universal microbes" in light-hydrocarbon microseepage ecosystems. The results indicated significantly higher bacterial diversity in next-to-well samples compared with background samples at two of the three sites, which were notably different to oil-contaminated environments. Variation partitioning analysis showed that the bacterial community structures above the oil and gas fields at the scale of the present study were shaped mainly by environmental parameters, and geographic location was able to explain only 7.05% of the variation independently. The linear discriminant analysis effect size method revealed that the oil and gas fields significantly favored the growth of Mycobacterium, Flavobacterium, and Pseudomonas, as well as other related bacteria. The relative abundance of Mycobacterium and Pseudomonas increased notably after n-butane cultivation, which highlighted their potential as biomarkers of underlying oil deposits. This work contributes to a broader perspective on the bacterial community structures shaped by long-term light-hydrocarbon microseepage and proposes relatively universal indicators, providing an additional resource for the improvement of microbial prospecting of oil and gas.

• Journal of Environmental Health Sciences
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• v.24 no.2
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• pp.74-79
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• 1998

This study was conducted to evaluate the surfactant solutions which influence solvent extraction from light hydrocarbon contaminated soils. Nine characteristic compounds were studied: benzene, toluene, ethylbenzene, o-xylene, mxylene, p-xylene, n-propylbenzene, 1,2,4-trimethylbenzene, and n-butylbenzene which were found in gasoline. Adsee-799 and Witbreak DRA-22 showed some extractive capacity for light hydrocarbons from soil. There was no added advantage obtained by using other surfactants in this study. No removal of contaminants from soil was observed when the surfactant concentration was 0.5 percent or below. When the surfactant concentration was 4 percent, the average recovery for some hydrocarbons was 10.8 percent, which was the best obtained at these levels. There was 10 percent surfactant contribution for methanol extraction from soil with the Witbreak DPG-482 and Witbreak DRA-22. This study provided a useful screening technique for procedures that can be used to remediate soils contaminated with light hydrocarbons.

• The Korean Journal of Physiology and Pharmacology
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• v.4 no.1
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• pp.41-46
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• 2000

Using fluorescence polarization of 12-(9-anthroyloxy)stearic acid (12-AS) and 2-(9-anthroyloxy)stearic acid (2-AS), we evaluated the differential effects of local anesthetics on differential rotational rate between the surface (in carbon number 2 and its surroundings including the head group) and the hydrocarbon interior (in carbon number 12 and its surroundings) of the outer monolayer of the total lipid fraction liposome extracted from synaptosomal plasma membrane vesicles. The anisotropy (r) values for the hydrocarbon interior and the surface region of the liposome outer monolayer were $0.078{\pm}0.001$ and $0.114{\pm}0.001,$ respectively. This means that the rate of rotational mobility in the hydrocarbon interior is faster than that of the surface region. In a dose-dependent manner, the local anesthetics decreased the anisotropy of 12-AS in the hydrocarbon interior of the liposome outer monolayer but increased the anisotropy of 2-AS in the surface region of the monolayer. These results indicate that local anesthetics have significant disordering effects on the hydrocarbon interior but have significant ordering effects on the surface region of the liposome outer monolayer.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2195-2201
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• 2009

This paper considers the influence of suction-line heat exchangers on the efficiency of a refrigeration cycle using hydrocarbon refrigerants such as R290, R600a and R1270. These suction-line heat exchangers can, in some cases, yield improved system performance while in other cases they degrade system performance. A steady state mathematical model is used to analyze the performance characteristics of refrigeration cycle with suction-line heat exchanger. The influence of operating conditions, such as the mass flowrate of hydrocarbon refrigerants, inner diameter tube and length of suction-line heat exchanger, to the performance of the cycle is also analyzed in the paper. Results showed that the mass flowrate of hydrocarbon refrigerants, inner diameter tube and length of suction-line heat exchanger, and effectiveness have an effect on the cooling capacity, compressor work and RCI(Relative Capacity Index) of this system. With a thorough grasp of these effect, it is necessary to design the compression refrigeration cycle of hydrocarbon refrigerants using suction-line heat exchanger.