• Journal of Environmental Impact Assessment
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• v.9 no.4
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• pp.277-290
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• 2000

The purpose of this study is to identify the problems of environmental impact assessment(EIA) and to suggest new EIA technology. The problems of EIA in Korea can be summarized as follows. First, the EIA does not reflect the impact of policy, plan and program on environment. Second, the project EIA does not consider the cumulative impacts such as additive impacts, synergistic impacts, threshold/saturation impacts, induced and indirect impacts, time-crowded impacts, and space-crowded impacts. Third, the EIA techniques in Korea are not standardized. Finally, the present EIA suggests only alternatives to reduce adverse impacts. To solve above-mentioned problems, the development of new EIA technology is essential. First, the new EIA technology should be developed toward pollution prevention technology and comprehensive and integrated environmental management technology. Second, new fields of EIA for pollution prevention contain strategic environmental assessment, cumulative impacts assessment, socio-economic impact assessment, cyber EIA and EIA technology necessary after the reunification of Korean Peninsula. Third, EIA technology for integrated environmental management contains the development of integated environment assessment system and the development of packaged EIA technology. The EIA technology for integrated environmental assessment system contains (1) development of integrated impact assessment technology combining air/water quality model, GIS and remote sensing, (2) integrated impact assessment of EIA, traffic impact assessment, population impact assessment and disaster impact assessment. (3) development of integrated technology combining risk assessment and EIA (4) development of integrated technology of life cycle assessment and EIA, (5) development of integrated technology of spatial planning and EIA, (6) EIA technology for biodiversity towards sustainable development, (7) mathematical model and GIS based location decision techniques, and (8) environmental monitoring and audit. Furthermore, there are some fields which need packaged EIA technology. In case of dam development, urban or industrial complex development, tourist development, landfill or combustion facilities construction, electric power plant development, development of port, road/rail/air port, is necessary the standardized and packaged EIA technology which considers the common characteristics of the same kind of development project.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.3
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• pp.148-154
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• 2018

When shooting small arms, the inner surface temperature is heated up to about $700{\sim}1,000^{\circ}C$ by the friction of the bullet and the inner wall of the barrel and the combustion of propellant. High-temperature propellant gas and high-speed movement of the bullet cause corrosion of the inner wall, which is noticeable immediately in front of the chamber. In this study, the mechanical properties of Cr-Mo-V steel, which is the base material, were tested using Taguchi experimental design to find the best nitriding treatment conditions. For the nitriding process, the working time, salt bath temperature, and salt concentration were combined as three conditions and placed in the $L_9(3^4)$, orthogonal array table. The thicknesses of the white layer and the nitrogen diffusion layer were measured after nitriding under each condition in a salt bath furnace. Durability was evaluated by measuring the degree of dispersion through actual shooting because it was difficult to evaluate the mechanical properties of the cylinder inner structure. As a result, it was confirmed that the durability was optimal at $565^{\circ}C$, 1 hour, 0.5%. These optimal conditions were selected by the statistical analysis of the Minitab program(ver.17).

• Asian Journal of Atmospheric Environment
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• v.5 no.2
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• pp.86-96
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• 2011

The positive matrix factorization (PMF2) and multilinear engine (ME2) models have been shown to be powerful environmental analysis techniques and have been successfully applied to the assessment of ambient particulate matter (PM) source contributions. Because these models are difficult to apply practically, the US EPA developed a more user-friendly version of the PMF. The initial version of the EPA PMF model does not provide any rotational capabilities; for this reason, the model was upgraded to include rotational functions in the EPA PMF ver. 2.0. In this study, PMF and EPA PMF modeling identified ten particulate matter sources including secondary sulfate I, vehicle gasoline, secondary sulfate II, secondary nitrate, secondary sulfate III, incinerators, aged sea salt, airborne soil particles, oil combustion, and diesel emissions. All of the source profiles determined by the two models showed excellent agreement. The calculated average concentrations of $PM_{2.5}$ were consistent between the PMF2 and EPA PMF ($17.94{\pm}0.30{\mu}g/m^3$ and $17.94{\pm}0.30\;{\mu}g/m^3$, respectively). Also, each set of estimated source contributions of the PMF2 and EPA PMF showed good agreement. The results from the new EPA PMF version applying rotational functions were consistent with those of PMF2. Therefore, the updated version of EPA PMF with rotational capabilities will provide more reasonable solutions compared with those of PMF2 and can be more widely applied to air quality management.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.4
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• pp.321-327
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• 2007

In an apartment house that is generally air-tight and well insulated, the combustion gas from cooking devices is the major source of air pollution in the kitchen. It spreads throughout the house affecting the overall Indoor all quality. In this study, the performance of the kitchen range hood which employs air induction and air curtain was investigated by numerical simulation. The results are compared with that of two other kitchen range hoods which are in general use. The two general types of range hoods considered in the present calculations are box and plate type range hoods. The former has a large capture space between the filter and suction duct, while the latter has little. It was found that the capture efficiency of the kitchen range hood with air induction and air curtain Is higher than that of the general types of range hoods by 20% approximately The reason may be because the air induction and the air curtain block the air stream escaping from the front and the side part of range hoods effectively and because an additional fan for air induction and air curtain increases suction flow rates.

• Journal of Forest and Environmental Science
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• v.33 no.2
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• pp.113-121
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• 2017

In flight particulate matter particularly emissions generated by incomplete combustion processes has become a subject of global concern due to the health problems and environmental impacts associated with them. This has compelled most countries to set standards for coarse and fine particles due to their conspicuous impacts on environment and public health. This contribution therefore explores forest fire emissions and how its particulates affects air quality, damage to vegetation, water bodies and biological functions as architects for lung diseases and other degenerative illnesses such as oxidative stress and aging. Soot was collected from simulated forest fire using a clean glass surface and carefully transferred into amber vials for analysis. Volatile components of soot were collected over 10 mL dichloromethane and analyzed using a QTOF Premier-Water Corp Liquid Chromatography hyphenated to a mass selective detector (MSD), and Gas Chromatograph coupled to a mass spectrometer (GC-MS). To characterize the size and surface morphology of soot, a scanning electron microscope (SEM) was used. The characterization of molecular volatiles from simulated forest fire emissions revealed long chain compounds including octadec-9-enoic acid, octadec-6-enoic acid, cyclotetracosane, cyclotetradecane, and a few aromatic hydrocarbons (benzene and naphthalene). Special classes of organics (dibenzo-p-dioxin and 2H-benzopyran) were also detected as minor products. Dibenzo-p-dioxin for instance in chlorinated form is one of the deadliest environmental organic toxins. The average particulate size of emissions using SEM was found to be $11.51{\pm}4.91{\mu}m$. This study has shown that most of the emissions from simulated forest fire fall within $PM_{10}$ particulate size. The molecular by-products of forest fire and particulate emissions may be toxic to both human and natural ecosystems, and are possible precursors for various respiratory ailments and cancers. The burning of a forest by natural disasters or man-made fires results in the destruction of natural habitats and serious air pollution.

• Journal of Environmental Health Sciences
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• v.33 no.6
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• pp.479-487
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• 2007

[ $PM_{2.5}$ ], particulate matter less than 2.5 um in a diameter, can penetrate deeply into the lungs. Exposure to $PM_{2.5}$ has been associated with increased hospital visits for respiratory aliments as well as increase mortality. $PM_{2.5}$ is a byproduct of combustion processes and as such has a complex composition including a variety of metallic elements, inorganic and organic compounds as well as biogenic materials (microorganisms, proteins, etc). In this study, the average concentrations of fine particulates $PM_{2.5}$ have been measured simultaneously in Asan and Seoul, Korea, by using particulate matter portable sampler from September 2001 to August 2002. Sample collection filters were analyzed by ICP-OES to determine the concentrations of metallic elements (As, Ni, Fe, Cr, Cd, Cu, Pb, Zn, Si). Annual mean $PM_{2.5}$ concentrations in Asan and Seoul were 37.70 and $45.83\;{\mu}g/m^3$, respectively. The highest concentrations of $PM_{2.5}$ were found in spring season in both cities and the concentrations of measured metallic elements except As in Asan were higher than those in Seoul, suggesting that yellow dust in spring could affect $PM_{2.5}$ concentrations in Asan rather than Seoul. The correlation coefficients of Pb and Zn were 0.343 for Asan and 0.813 for Seoul during non-yellow dust condition, suggesting that Pb and Zn were influenced with the same sources. The correlation coefficients between Si and Fe in the fine particulate mode were 0.999 (Asan) and 0.998 (Seoul) during yellow dust condition. It was suggested that these two elements were impacted by soil-related transport from China during the yellow dust storm condition.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.4
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• pp.439-444
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• 2011

To determine the test gases for gas appliances of new gas group, the interrelation between gas interchangeability, including thermal efficiency, of 13A gas appliances and present 13A test gases was experimentally investigated. The test results show that the Wobbe indices in the case of incomplete combustion and the flame lifting limit gas for the new gas group are respectively 2% higher than the upper limit and 1% lower than the lower limit of the Wobbe index range. The most suitable composition of R gas is 96 mol% of methane and 4 mol% of propane; LNG could be also used as R gas. Further, analysis results showed that the hydrogen concentration of flash back limit gas could be lowered from 30 vol% to 23 vol%.

• Tribology and Lubricants
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• v.28 no.6
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• pp.315-320
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• 2012

For proper functioning, general machines usually need lubricant oil as a cooling, cleaning, and sealing agent at points of mechanical contact. The quality of lubricant oil can deteriorate during operation owing to various causes such as high temperature, combustion products and extraneous impurities. In this study, a heavy load stopped during operation, and the oil was analyzed to check whether any impurities were added. Extraction using acetonitrile followed by reaction with BSTFA(bistrimethylsilyl trifluoroacetamide) showed that, trimethylsilylated ethylene glycol was present in the lubricant oil. To quantify the ethylene glycol in the oil, deuterium-substituted ethylene glycol, which acted as an internal standard, was added to the sample and then extracted with the solvent. Next, the extract was reacted with the derivatizing agent(BSTFA) and then analyzed with GC/MS. The detection limit of this method was found to be $0.5{\mu}g/g$ and the recovery of oil containing $20,000{\mu}g/g$ of ethylene glycol was measured to be 94.8%. A damaged O-ring and eroded cylinder liner were found during the overhaul, which implied the leakage of coolant containing ethylene glycol into the lubricating system. The erosion of the cylinder liner was assumed to be due to cavitation of the coolant in the cooling system.

• Journal of Ocean Engineering and Technology
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• v.22 no.3
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• pp.82-88
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• 2008

The diesel engine of the merchant ship has been aperated in severe environments more and more, because the temperature of the exhaust gas of a combustion chamber is getting higher and higher with increasing use of heavy oil of law quality, due to the significant increase in the price of oil in recent some years. As a result, the degree of wear and corrosion between exhaust valve and seat ring is more serious compared to other engine parts. Thus the repair welding of exhaust valve and seat ring is a unique method to prolong the life of the exhaust valve, from an economical point of view. In this study, the corrosion property of both weld metal and base metal was investigated using electrochemical methods such as measurement of corrosion potential, cathodic and anodic polarization curves, cyclic voltammogram, and polarization resistance in 5% H2SO4 solution. The test specimen was a part of an exhaust valve stem being welded as the base metal, using various welding methods. In all cases, the corrosion resistance as well as hardness of the weld metal zone was superior to the base metal. In particular, plasma welding showed relatively good properties for both corrosion resistance and hardness, compared to other welding methods. In the case of DC SMAW (Shielded metal arc welding), corrosion resistance of the weld metal zone was better than that of the base metal, although its hardness was almost same as the base metal.

• Plant Journal
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• v.15 no.3
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• pp.23-28
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• 2019

In this study, ammonia consumption by gas turbine output was adjusted to find out the amount of ammonia consumption that complies with the enhanced Air Quality Preservation Act and internal regulation emission standards in SCR type DeNOx System for a 580 MW Sejong Combined Cycle Power Plant. For measurements, the gas turbine output was varied to 50, 99, 149, 198 MW and ammonia consumption was adjusted with the combustion gas and ammonia supply conditions fixed at each stage. When the emission limit were change from 10 ppm to 8 ppm, ammonia consumption was increased from 78, 93, 105, 133 kg/h to 89, 113, 132, 176 kg/h. The increase rate of ammonia consumption was 14, 22, 26, 32% per output category compared to the 10 ppm emission limit, which was shown to increase as output increased.