• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.6
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• pp.51-56
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• 2009

Safety and quality assessment systems are very important in manufacture, storage, transportation, and handling of hazardous materials(hazmat) to prevent hazmat disasters. At present, hazardous materials exist everywhere in our daily lives with various forms of plastics, household products of cleaning and washing detergents, fertilizers or petroleum-related products. However, hazardous materials are dangerous substances when they are released to human or environment. Hazardous materials become very widely used substances in the age of oil-based industrial economy. The Korean Ministry of Environment (KMOE) describes about one hundred thousand types of chemicals are produced and used worldwide. Over four hundred new chemicals are introduced in every year. A crucial question for the Korean hazardous material management may have been raised: Will you be safe from hazardous material incidents? The gas leak disaster at Union Carbide's Bhopal, India in 1984 that made over 6,400 people killed and 30,000 to 40,000 people seriously injured is the representative case for the safety of hazmat. Korea becomes vulnerable to hazmat disaster due to the development of high-tech industry. Thus, the risk assessment system is required to Korea for transferring abandoned hazmat management systems to self-correcting safety systems. This research analyzed characteristics of various hazmat incidents applying statistical analysis methods including frequency analysis or analysis of category data to hazmat incidents for ten years. All of three analyses of category data indicate the significance of causality between hazmat incident site groups and seasons, regional groups, and incident casualty groups.

• Economic and Environmental Geology
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• v.40 no.5
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• pp.623-633
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• 2007

Stable isotope and biomarker analyses were carried out for the organic sediments from the exploratory wells in the Jeju Basin in order to understand the characteristics of organic matter. Organic matter in Geobuk-1, Okdom-1, JDZ VII-1 and VII-2 well is predominantly originated from land plants rather than marine algae according to carbon $({\delta}^{13}C_{org})$ and nitrogen $({\delta}^{15}N_{org})$ isotopic compositions. In the Geobuk-1, geochemical characteristics such as carbon $({\delta}^{13}C_{org})$, nitrogen ($({\delta}^{15}N_{org})$ and TOC contents are obviously changed by the depth 2,400 m, which is likely due to the change of origin of organic matter, sedimentary process or sedimentary environments. Analysis of the saturated fraction of the bitumen suggests the contribution of migrated oil to the indigenous bitumen from the samples 2,509, 2,833 and 3,163 m of the JDZ YII-1 and 3,253 m of the Geobuk-1 well. However, this characteristics can be derived from the contribution of the original organic matter. Based on the biomarker analysis, the samples from the Okdom-1 and Geobuk-1 appear to represent sedimentary organic matter of similar composition, that is rotatively immature, and which was probably deposited in the fluvio-deltaic setting with minor offshore marine influence. The samples from JDZ VII-1 appear to have been deposited in a more terrestrially dominated setting.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.9
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• pp.822-829
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• 2015

In this paper, the piezoelectric-hydraulic pump with a piezostack actuator as a driving source has been designed, fabricated, and evaluated for its application to UAV's brake system. The performance requirements of the piezoelectric-hydraulic pump were decided based on the requirements analysis of the target aircraft brake system. The geometric design of the piezoelectric-hydraulic pump to meet the performance requirements of the pump was conducted, and all components of the pump including the spring sheet type check valves were machined with close tolerance. By constructing a test apparatus for the performance check of the piezoelectric-hydraulic pump, the performance characteristics of the pump, such as the outlet flow rate for load-free condition and the outlet oil pressure for closed loop condition, have been evaluated. It has been found by the performance test result that the developed piezoelectric-hydraulic pump satisfies the design requirements effectively.

• Journal of Environmental Impact Assessment
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• v.20 no.4
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• pp.497-507
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• 2011

This research studied human health risk assessment of benzene from industrial complexes of Chungcheong Province (Seosan industrial complex) and Jeonla Province (Iksan industrial complex and Yeosoo industrial complex). The residents near the industrial complexes areas can be often exposed to volatile organic compounds (e.g., benzene, toluene, xylenes) through a number of exposure pathways, including inhalation of the organic pollutant via various environmental matrices (air, water and soil), contaminated water, and soil intake. Benzene is well known to be a common carcinogenic and toxic compound that is produced from industrial and oil refinery complexes. In this study, a number of samples from water, air, and soil were taken from the residential settings and public school zones located near the industrial complex sites. Based on the carcinogenic risk assessment, the risk estimates were slightly above $10{\times}10^{-6}$ at all three industrial sites. According to deterministic risk assessment, inhalation was the most important route. The distribution of benzene in the environment would be dependent on vapor pressure, and the physical property influencing the extent of the potential risks. Non-carcinogenic risk assessment of benzene shows that the values of Hazard Index(HI) were much lower than 1.0 at all industrial complexes. Therefore, benzene was not a cause of concern in terms of non-carcinogenic risk posed to the residents near the sites. When compared to probabilistic risk assessment, the CTE(central tendency exposure) cancer risk values of deterministic risk assessment were close to the mean values predicted by the probabilistic risk assessment. The RME(reasonable maximum exposure) values fell within the range of 95% to 99.9% estimated by the probabilistic risk assessment. Since the values of carcinogenic risk assessment were higher than $10{\times}10^{-6}$, further detailed monitoring and refined risk assessment for benzene may be warranted to estimate more reliable and potential inhalation risks to receptors near the industrial complexes.

• Journal of Life Science
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• v.21 no.7
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• pp.1046-1051
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• 2011

Diallyl disulfide (DADS), the most prevalent oil-soluble organosulfur compound in garlic, is known to have diverse biological activities, including anticarcinogenic, antiatherosclerotic, antiinflammatory, and antioxidant actions. In this study, we investigated the effect of DADS on the expression of heme oxygenase-1 (HO-1) in human liver hepatoma cell line HepG2. Treatment of HepG2 cells by DADS evoked a dose-dependent growth inhibition without significant toxicity to the cells, and also induced the expression of transcription factor Nrf2. However, DADS did not have any enhancing effect on transcription and translation of HO-1 expression in HepG2 cells. In addition, DADS efficiently blocked protein synthesis of HO-1 in HepG2 cells stimulated by CoPP or hemin. But, DADS did not decrease the content of transcripts of HO-1 gene stimulated by CoPP, with accumulation of Nrf2 and small Maf in the nucleus. Based on these results, we conclude that DADS inhibits HO-1 expression by modulation of translational level of CoPP or hemin-induced HO-1 expression in HepG2 cells.

• Journal of Life Science
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• v.27 no.2
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• pp.194-201
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• 2017

Rapeseed (Brassica napus L.) is an oil crop classified as Brassicaceae, and it is widely grown worldwide. To develop a drought-resistant rapeseed, the ${\beta}$-glucosidase 1 (AtBG1) gene was introduced into rapeseed because drought- and salt-resistance phenotypes were observed when the AtBG1 gene was overexpressed in arabidopsis. Newly developed genetically modified crop must be proved to be safe. Safety assessments are based on the historical usage and scientific reports of a crop. In this study, we examined the potential acute oral toxicity of AtBG1 protein expressed in genetically modified (GM) rapeseed and calculated the minimum lethal dose at 6 weeks in both male and female ICR mice. AtBG1 protein was fed at a dose of 2,000 mg/kg body weight in five male and five female mice according to the marginal capacity concentration of OECD, 2,000 mg/15 ml/kg. Mortalities, clinical findings, and body weight changes were monitored for 14 days after dosing, and postmortem necropsy was performed on day 14. This study showed that no deaths occurred in the test group, and AtBG1 protein did not result in variations in common symptoms, body weight, and postmortem findings between the two groups. This showed that the minimum lethal dose of AtBG1 protein expressed in transgenic rapeseed exceed 2,000 mg/kg body weight in both sexes.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.4
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• pp.533-540
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• 2012

The use of wind energy is gaining importance because of its many advantages. Nations worldwide are promoting the installation of wind farms to produce electricity in an attempt to tackle climate change and increasing oil costs. But, wind turbines can generate undesired signals which disturb the performance of military radar systems. Because the current generation of on and off-shore three bladed wind turbines have radar signatures consistent with their very large physical size. So this study considers the options available for the reduction of wind turbine radar signature and presents solutions for each of the main external turbine components. The radar signature reduction approaches are based on existing technologies developed for aerospaces stealth applications. However, the realization of these for the purposes of reduction wind turbine radar signatures is a novel development, particularly in the solutions proposed. This paper is presented techniques which reduce radar signatures of wind turbine. We know that radar signatures of wind turbine reduce by using these techniques.

• Journal of the Korean Chemical Society
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• v.38 no.9
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• pp.640-652
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• 1994

This work is undertaken to determine alcohol homologues so-called fusel oil that may be present in the Korean folk sojues (distilled liquor) made from grains and to describe sample preparation and analytical method by GC-FID-MS. Solid phase extraction method for sample preparation by using porous styrene divinyl benzene polymer (Porapak Q) was compared with steam distillation and solvent extraction method. Retention behaviors of homologous series of alcohols were also studied. Log values of retention time, molecular weight, boiling point, and capacity factor of alcohols showed linear correlations to the carbon number of an alcohol, to the oven temperature, and to the dielectric constant. Components such as methyl alcohol, n-propyl alcohol, isobutyl alcohol, isopentyl alcohol, and phenethyl alcohol have been identified. The more amount of isopentyl alcohol than other alcohols are contained in the Korean folk sojues, while that of n-propyl alcohol are contained in Chinese kaoliangchiew. Degree of similarity or dissimilarity and classification of the individual samples were discussed using multivariate statistical analysis(principal components analysis) based on GC data.

• Environmental and Resource Economics Review
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• v.26 no.4
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• pp.519-547
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• 2017

This paper explores whether it is better to forecast city gas demand in Korea using national level data directly or, alternatively, construct forecasts from regional demand models and then aggregate these regional forecasts. In the regional model, we consider gas demand for Seoul metropolitan and the other local areas. Our forecast evaluation exercise for 2013-2016 shows the regional forecast model generally outperforms the national forecasting model. This result comes from the fact that the dynamic properties of each region's gas demands can be better taken into account in the regional demand model. More specifically, the share of residential gas demand in the Seoul metropolitan area is above 50%, and subsequently this demand is heavily influenced by temperature fluctuations. Conversely, the dominant portion of regional gas demand is due to industrial gas consumption. Moreover, electricity is regarded as a substitute for city gas in the residential sector, and industrial gas competes with certain oil products. Our empirical results show that a regional demand forecast model can be an effective alternative to the demand model based on nation-wide gas consumption and that regional information about gas demand is also useful for analyzing sectoral gas consumption.

• Journal of the Korean Applied Science and Technology
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• v.31 no.1
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• pp.113-119
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• 2014

The compositions of saturated and unsaturated fatty acids in biodiesel feedstocks are important factors for biodiesel properties including low-temperature fluidity and oxidative stability. This study was conducted to improve low-temperature fluidity of biodiesel by reducing total saturated FAME (fatty acid methyl ester) in animal fat biodiesel fuels via urea-based fractionation and by mixing plant biodiesel fuels (rapeseed-FAME, waste cooking oil-FAME, soybean-FAME, and camellia-FAME) with enriched-polyunsaturated FAME derived from animal fat biodiesel. Our results showed that the reduction of total saturated FAME in animal fat biodiesel lowered CFPP (Cold Filter Plugging Point) to $-15^{\circ}C$. Mixing plant biodiesel fuels with the enriched-polyunsaturated FAME derived from animal fat biodiesel lowered CFPP of blended biodiesel fuels to $-10{\sim}-18^{\circ}C$.