• 한국전산유체공학회:학술대회논문집
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• 2005.10a
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• pp.219-222
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• 2005

Recently, the interest of the engine capacity and environment of the atmosphere is increasing, so the researches for the engine capacity have been conducted for a long time. But the internal environment of an automotive engine is very severe. A piston is exposed to combustion gas of over $2000^{\circ}C$ and strong friction is occurred by high speed motion in the cylinder. The fraction between piston and wall of the cylinder causes the increase of temperature in the engine. The temperature of the engine has an effect on the engine capacity. If the temperature is high, the capacity of the engine is low. So we have to maintain the optimum temperature. To maintain the optimum temperature, the enough flow rate of the engine oil is needed. The oil jet is used to control the flow rate of the engine oil and supply the engine oil to the piston and cylinder. The purpose of this study is to check the mass flow rate of the engine oil and the characteristics of internal flow of the oil jet. Flow pattern of the engine oil is very important because it concludes the loss in the oil jet. This study is the previous research about the oil jet and we will consider the movement of the ball check valve to get more accuracy result.

• Applied Chemistry for Engineering
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• v.30 no.2
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• pp.155-159
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• 2019

As a part of improving the quality for the fraction of the waste plastics pyrolysis oil (WPPO), the recovery of paraffin components contained in the fraction was investigated by dimethylformamide (DMF) equilibrium extraction. The fraction of a distilling temperature of $120{\sim}350^{\circ}C$ recovered from WPPO by the simple distillation and the aqueous solution of DMF were used as a raw material and solvent, respectively. The concentrations of paraffin components ($C_{12}$, $C_{14}$, $C_{16}$ and $C_{18}$) contained in the raffinate decreased by increasing the mass fraction of water in the solvent at an initial state ($y_{w,0}$), whereas, the concentrations of paraffin components contained in the raffinate increased by increasing the mass ratio of the solvent to the feed at an initial state $(S/F)_0$. The concentrations of $C_{12}$, $C_{14}$, $C_{16}$ and $C_{18}$ paraffin components present in the raffinate recovered at $(S/F)_0=10$ were about 1.37, 2.0, 2.46 and 3.16 times higher than those of the raw materials, respectively. Recovery rates (residue rates present in raffinate) of paraffin components rapidly increased with increasing $y_{w,0}$, and decreasing $(S/F)_0$. The raffinate recovered through this study was expected to be used as a renewable energy.

• Natural Product Sciences
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• v.14 no.2
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• pp.138-142
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• 2008

The composition of essential oils from Chrysanthemum zawadskii var. latilobum and C. indicum were analyzed and compared. The results of gas chromatography-mass spectrometry revealed there were distinctly different compositional patterns between C. zawadskii var. latilobum and C. indicum essential oils. The combinatorial effect of the oil of C. zawadskii var. latilobum and C. indicum, with various antibiotics was assessed against antibiotic-susceptible and -resistant strains of Staphylococcus aureus and Streptococcus pneumoniae. The essential oil fraction significantly inhibited most of the tested antibiotic-susceptible and -resistant strains of S. pneumoniae, with minimum inhibiting concentrations (MICs) ranging from 0.5 to 4.0 mg/ml. The fractional inhibiting concentration indices (FICIs) of the oils when combined with antibiotics against S. aureus and S. pneumoniae ranged from 0.26 to 0.75, and showed synergistic or additive effects.

• Journal of Korean Society for Atmospheric Environment
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• v.13 no.5
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• pp.345-353
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• 1997

The purpose of the study was to stastically classify individual PM-10 measured by SEM/EDX (scanning electron microscopy/energy dispersive x-ray analyzer). The SEM/EDX provided various physical parameters like optical diameter, as well as major 18 chemical information (Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Pb) for a particle-by-particle basis. The total of 1,419 particles were analyzed for the study. Thus density and mass of each particle can be estimated based on its chemical composition. Further the study developed 4 semisource profiles including highway, oil boiler, incinerator, and soil emissions, where each sample was collected near the source in the ambient air The profiles developed were consisted of mass fractions and their uncertainties based on a particle class concept. To obtain mass fraction of each particle class, an agglomerative hierarchical cluster analysis was initially applied to create particle classes for each sample. Then uncertainties were calculated for each class based on the jacknife method. The 1,258 particles out of 1,419 (88.7%) were assorted in newly generated particle classes. The study provides opportunities to identify particle's source quantitatively and to develope various receptor models.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.195-199
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• 2005

As vehicles are recently becoming more important in our life, the study for engine capacity has been conducted for many years. Specially, the study on lubrication in the engine is needed to develop engine capacity. The role of lubrication is to reduce fraction, manage the temperature and protect from corrosion etc. At the view point of the engine, lubrication and cooling of the engine have an effect on the life and efficiency, so we have to study this problem. Ball check valve is located in the inlet of the Oil Jet. Ball check valve is used to control the flow rate of the engine oil, which cools and lubricates the engine. Flow rate at the oil jet is very important, so the study for this problem is needed to conduct researches. The point of this study is to compute the flow rate and the flow in oil jet. The results of this study is that the mass flow rate is satisfied with the research which is obtained at the experiment.

• Microbiology and Biotechnology Letters
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• v.27 no.3
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• pp.179-183
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• 1999

The volatile components (essential oil) showing antimicrobial activity were extracted from the fruit peel of Zanthoxylum piperitum DC by distillation and separated by thin layer chromatography (TLC). The crude volatile components exhibited antimicrobial activity only at very high concentration. The active fraction obtained by TLC inhibited noticeably the growth of bacteria. The minimum inhibitory concentration (MIC) of the fraction were 150ppm, 300ppm, and 300ppm against Escherichia coli, Staphylococcus aureus, and Salmonella enteritidis, respectively. The components in the active fraction were identified by gas chromatography/mass spectrometry to be geranlyl acetate (60.23%), citronellal(36.01%), citronellol(3.77%), geraniol(0.46%), and cumin ldehyde(0.43%).

• Coupled systems mechanics
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• v.8 no.2
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• pp.129-146
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• 2019

The main goal of this work is to develop a numerical simulator to study an isothermal single-phase two-component flow in a naturally fractured oil reservoir, taking into account advection and diffusion effects. We use the Peng-Robinson equation of state with a volume translation to evaluate the properties of the components, and the discretization of the governing partial differential equations is carried out using the Finite Difference Method, along with implicit and first-order upwind schemes. This process leads to a coupled non-linear algebraic system for the unknowns pressure and molar fractions. After a linearization and the use of an operator splitting, the Conjugate Gradient and Bi-conjugated Gradient Stabilized methods are then used to solve two algebraic subsystems, one for the pressure and another for the molar fraction. We studied the effects of fractures in both the flow field and mass transport, as well as in computing time, and the results show that the fractures affect, as expected, the flow creating a thin preferential path for the mass transport.

• Korean Journal of Pharmacognosy
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• v.19 no.4
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• pp.239-247
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• 1988

Essential oil of the root of Angelica gigas Nakai (Umbelliferae) was investigated. Essential oil was obtained from the dried roots by steam distillation and fractionated by column chromatography. Each isolate or fraction was identified by GC, GC-MS and spectral analysis. It was found to contain eleven monoterpenes such as ${\alpha}-pinene,\;camphene,\;{\beta}-pinene,\;myrcene,\;{\alpha}-phellandrene,\;{\Delta}-3-carene,\;{\alpha}-terpinene,\;p-symene,\;limonene,\;{\gamma}-terpinene$ and terpinolene and also found to contain 4-vinylguauacol, myristicin, elemol, ${\beta}-eudesmol,\;{\alpha}-eudesmol,\;four\;sesquiterpenes\;involving\;{\Delta}-elemene$. Four sesquiterpenes and five sesquiterpene alcohols were tentatively identified by comparison of their mass spectra.

• Korean Journal of Pharmacognosy
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• v.1 no.4
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• pp.119-124
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• 1970

Evodia daniellii $H_{EMSLEY}$, a plant belonging to Rutaceae, is cultivated in Korea and used as a folkmedicine for gastric inflammation, extermination of noxious insects, and headache. The seed oil of this plant also has been used in various diseases, for example, dermatitis, scabies and so forth. From the barks, fruit peels, and seed oil of Evodia daniellii $H_{EMSLEY}$, four crystalline compounds were isolated. Three compounds except one were characterized as methyl sinapate, bergapten, and evodiamine by m.p. determination, elemental analysis, UV, IR, NMR spectra and mass analysis. Even though methyl sinapate was a known synthetic compound, it was not yet reported as a natural product. From the seed oil, unsaponifiable fraction was separated and was analyzed. It was considered to be consisted with sterols, hydrocarbons and tocopherols.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.3
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• pp.353-360
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• 2006

This study identified a particle size distribution (PSD) of fine particulate matter and emission characteristics of V and Ni by the comparison between anthropogenic sources of oil combustion (industrial boiler, oil power plant, etc.) and lab-scale combustion using a drop-tube furnace. In oil combustion source, the mass fraction of fine particles (less than 2.5 micrometers in diameter) was higher than that of coarse particles (larger than 2.5 micrometers in diameter) in $PM_{10}$ (less than 10 micrometers in diameter) as like in lab-scale oil combustion. In addition to this, it was identified that ultra-fine particles (less than 0.1 micrometers in diameter) had a large distribution in fine particles. Toxic metals like V and Ni had large mass fractions in fine particles, and most of all was distributed in ultra-fine particles. Most of ultra-fine particles containing toxic metals have been emitted into ambient by combustion source because it is hard to control by the existing air pollution control device. Hence, we must be careful on these pollutants because it is obvious that these are associated with adverse health and environmental effect.