• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.395-399
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• 2017

The LPI fuel filter housings used in automobiles were made from conventional die castings but have recently been developed by cold forging to improve the weight and durability. On the other hand, a sink may develop at the core of the forged product due to the resulting T-shape, which not only reduces the aesthetics, but also increases the post-processing cost of the product. Therefore, this research focused on methods to predict and mitigate sink development and progression during the T-shape forging process. Finite element analysis of the forging process was first performed to determine the optimal initial workpiece devoid of burrs and underfills. An accurate sink prediction was then obtained via metal flow analysis, which was a result of the finite element simulation. Through finite element analysis, it was confirmed that sink development is a product of the differences in nodal velocities arising from the T-shaped forging process. Consequently, a pad was inserted beneath the sink to minimize these velocity differences. The results yielded significant improvement with regard to the sink defect. This method was practically applied to an industrial site to validate the sink improvement.

• KSBB Journal
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• v.23 no.4
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• pp.335-339
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• 2008

Biodiesel is an alternative and renewable energy source, which is hoped to reduce global dependence on petroleum and environmental problem. Biodiesel produced from a variety of oil sources such as vegetable oil, animal fat and waste oils, and has properties similar to those associated with petro-diesel, including cetane number, volumetric heating value, flash point, viscosity and so on. In this study, we investigate the effect of quality of raw materials on alkali-catalyzed transesterification for producing of biodiesel. The increase of content of free fatty acid and water in oil were caused the sharp decrease of conversion yield. Also, the low purity of methanol in reactant was inhibited the reaction rate. In the case of addition of sodium sulfate as absorbent to prepare catalyst solution, the content of fatty acid methyl ester in product was increased more about 1.6% than that of control. However, the addition of zeolite, sodium chloride and sodium sulfate as absorbent in reactant to remove water generated from reaction did not show any enhancement in the reaction yield. This result may provide useful information with regard to the choice and preparation of raw materials for more economic and efficient biodiesel production.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.06a
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• pp.359-365
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• 1999

We have evaluated the performance and some physical properties of 25 automotive engine oils (21 domestic and 5 imported products) which are purchased on the market to verify the API(American Petroleum Institute) or ILSAC(International Lubricant Standardization and Approval Committee) certification marks attached on the products and to determine the necessity of the quality control of the engine oils on the market. 12 test items are chosen according to API engine oil specification, which are flash point, pour point, cold cranking simulator apparent viscosity, pumping viscosity, gelation index, HTHS(High Temperature High Shear viscosity), foam, high temperature foam, filterability, volatility, high temperature deposit(TEOST), phosphorus content. We have found one product which did not meet the API specification on gelation index, one on HTHS, four on foam, and one on volatility, which implies that the quality control system is in need to check the fidelity of the certification marks attached on the engine oils being marketed. In addition, this works raises the necessity of the upgrade of the present Korean engine oil specification.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.251.2-251.2
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• 2010

Plant biomass has been proposed to be an alternative source for petroleum-based chemical compounds. Especially, phenolic chemical compounds can be obtained from lignin by chemical depolymerization processes because lignin consists of complex aromatic polymer such as trans-p-coumaryl, coniferyl and sinapyl alcohols, etc. Phenolic chemical compounds from lignin were usually produced in super critical water. However, we applied Near-critical water (NCW) system because NCW is known as a good solvent for lignin depolymerization. Organic matter like lignin can be solved in NCW system and the system has a unique acid-base property without conventional non-eco-friendly chemicals such as sulfuric acid and sodium hydroxide. In this work, we tried to optimize the NCW depolymerization system by adjusting the processing variables such as reaction time, temperature and pressure. Moreover, the amount of additional phenol was optimized by changing the molar ratio between water and phenol. Phenol was used as capping agent to prevent re-polymerization of active fragment such as formaldehyde. Alkali-lignin was used as a starting material and characterized by a Solid State 13C-NMR, FT-IR and EA (Elemental Analysis). GC-MS analysis confirmed that o-cresol, p-cresol, anisole and 4-hydroxyphathalic acid were the main product and they were quantitatively analyzed by HPLC.

• Journal of the Korea Furniture Society
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• v.26 no.1
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• pp.22-30
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• 2015

In order to prevent decay, distortion, bending, twist on wood products such as wooden furnitures, variety of coating materials were developed and used so far. The coating materials for wood finishing can be synthesized by natural resource or petroleum. However, these coating materials can cause contamination of indoor air quality due to emission of volatile organic compounds (VOCs). In this study, commercialized coating materials for wood finishing such as varnish, coat, and stain were evaluated on emission characteristics of VOCs. Among the varnish, eco-friendly products had about 15~46% lower TVOC emission ($1,042{\mu}g/m^2h{\sim}3,257{\mu}g/m^2h$, respectively, than typical product ($7,100{\mu}g/m^2h$). Natural resource based coating material showed lowest TVOC emission level. However, one of natural resource based waterborne stain showed higher TVOC emission level because waterborne stain already contained higher amount of natural VOC. Oil-based stain might not be suitable for indoor use on interior wall and furniture due to exceed amount of TVOC. Based on results, natural resource based coat or waterborne stain are recommenced to use on wood products.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.1
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• pp.22-28
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• 2004

The fate and transport mechanism of pollutants which have affinities to particles, such as trace metals and some petroleum product based compounds, can be effectively explained by the movement of sediment. The sediment release from lands to adjacent water bodies due to rainfall events was investigated in an effort to predict the total suspended solids (TSS) concentrations in runoff. The contribution of sediment from land origin to the river TSS can be better understood by the relationship between TSS concentration and particle size in runoff. The sieve analysis was used to determine the particle size distribution and these results were incorporated into statistical models. The critical size of particles was set to $74{\mu}m$ which contributes to the river TSS concentration since fine particles (wash load) of the sediment in the runoff play the key role in constituting TSS in a water column of the river. Empirical relationships were developed to predict TSS in runoff from the percentage of the critical particle size and were proven statistically to be valid.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1123-1123
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• 2001

In recent years, a miniature spectrometer has been extensively developed due to the marriage of fiber optics and semiconductor detector array. This type of miniature spectrometer has advantages of low price and robustness due to the capability of mass production and no moving parts are required such as lenses, mirrors and scanning monochromator. These systems are ideal for use in teaching labs, process monitoring and field analyses. A portable near infrared (NIR) system has been developed for qualitative and quantitative analysis. This system includes a tungsten halogen lamp for light source, a fiber optics connected a light source, and a sample module to the microspectrometer, The size of spectrometer can be as small as 2.5 cm x 1.5 cm x 0.1 cm. Wavelength ranges can be chosen as 360-800 nm, 800-1100 nm and 1100-1900 nm depending on the type of detector. The software consists of various tools for multivariate analysis and pattern recognition techniques. To evaluate the system, long and short-term stability, wavelength accuracy, and stray light have been investigated and compared with conventional scanning type NIR spectrometer. This developed system can be sufficiently used for quantitative and qualitative analysis for various samples such as agricultural product, herbal medicine, food, petroleum, and pharmaceuticals, etc.

• Journal of Environmental Science International
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• v.13 no.4
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• pp.349-357
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• 2004

Emergy is a measure of the processes required to produce something expressed in units of the same energy form. Emergy based indices can provide insights into the thermodynamic efficiency of the process, the quality of its output, and the interaction between the process and its surrounding environment. However, in an industrial system, the inputs are mostly nonrenewable, renewable energy source is nearly zero, ultimate purpose is pursuit of profits in economic activity. In study, we present two indices based on emergy - EEE(Ecological Economic Efficiency) and ERI(Environmental Responsibility Index). The EEE is taken into account real value of product in market economy. The ERI is shown to be a function of the net yield of the economy, its ‘load’ on the environment and ecological economic efficiency. Manufacturing industry of Korea produced the 30% of total GDP in 2001. We applied these indices to manufacturing industry for environmental management and further sustainable industry. As a results, the highest ERI is 0.34 in recycling industries, the lowest ERI is 0.01 in coke, refined petroleum products which is dominated by ELR. The higher ERI, the more friendly to environment. The suggested indices help us understand relative contributions of various alternatives in company's production and consumption activity, and provide a tool of decision-making for the rearrangement of future industries. Furthermore, they contribute to environmental friendly operation and consumption.

• Natural Product Sciences
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• v.5 no.1
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• pp.1-6
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• 1999

This study was devised to observe the antitumor activity of mugwort (Artemisia princeps Pampan.) against ICR mice inoculated with sarcoma-180 cells. The antitumor compounds were partially purified from petroleum ether extract of mugwort by silicic acid column chromatography. The active fraction used in in vivo test was obtained under the elution with acetone in silicic acid column chromatography. When the acetone fraction was intraperitoneally injected to the mice which had been subcutaneously inoculated on the left groin with sarcoma-180, the growth rate of tumor (sarcoma-180 mass) was inhibited by 30%. In case the acetone fraction was injected to the mice which had been inoculated intraperitoneally with sarcoma-180, the average life span was prolonged by 20%. After the injection of the active fraction, the spleen index and ${\gamma}-globulin$ ratio (%) were increased significantly (p<0.05). The administration of acetone fraction did not cause any abnormality in the body and the homeostasis of mice. Those observations suggest that the acetone fraction of mugwort extract has an antitumor effect in vivo.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.9
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• pp.196-201
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• 2000

There is a great demand for reducing the amount of material used in mass-produced plastics parts for material cost constitutes a large percentage of the total cost of a product up to 75% It may be noted that the price of plastics is directly related to the price of petroleum. Material reduction therefore decreases the amount of oil needed for the manufacture of plastics and thus help conserve this natural resource. Therefore microcellular foaming process(MCPs) was studied for solving this problems alternatively in 1980's at M. I. T. Until now in microcellular plastics processes carbon dioxide gas was mainly used for microcellular foaming Because carbon dioxide has more solubility than any other gases such as nitrogen gas or helium gas. The purpose of the this research is measurement of changing of the microcellular plastics' weight by using nitrogen gas in injection molding an comparing weight reduction of microcellular foamed plastics for using carbon dioxide gas with nitrogen gas.