• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.18-24
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• 2018

The policy-making and technological development of eco-friendly automobiles designed to increase their supply is ongoing, but the internal combustion engine still accounts for about 95% of the automobiles in use. Also, in order to meet the stricter emission regulations of internal combustion engines based on fossil fuels, the proportion of after-treatments for vehicles and (ocean going) vessels is gradually increasing. Natural gas is a clean fuel that emits few air pollutants and has been used mainly as a fuel for city buses. In the long term, we intend to develop a new NGOC/LNT+NGCO/SCR combined system that simultaneously reduces the toxic gases, $CH_4$ and NOx, emitted from CNG buses. The objective of this study is to investigate the characteristics of $de-CH_4/NOx$ according to the ceramic and metal substrates of the SCR (Selective Catalytic Reduction) catalysts mounted downstream of the combined system. The V and Cu-SCR catalysts did not affect the $CH_4$ oxidation reaction, the two NGOC/SCR catalysts each coated with two layers began to oxidize $CH_4$ at $400^{\circ}C$, and the amount of $CH_4$ emitted was reduced to about 20% of its initial value at about $550^{\circ}C$. The two NGOC/SCR catalysts each coated with two layers showed a negative (-) NOx conversion rate above $350^{\circ}C$. The ceramic-based combined system reached LOT50 at $500^{\circ}C$, which was about 20% higher in terms of the $CH_4$ conversion rate than the metal-based combined system, showing that the combined system of NGOC/LNT+Cu-SCR is a suitable combination.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.25 no.2
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• pp.9-25
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• 2020

In 2010 and 2015, total 77 surface sediment samples were collected to assess the anthropogenic effects of trace metals in surface sediments of Garolim Bay, and the physical characteristics (particle size and specific surface area) and geochemical components (major (Al, Ca, Fe, K, Ba) and trace metals (Mn, Cs, Cr, Co, Ni, Cu, Zn, Pb), organic carbon and calcium carbonate) were analyzed. Mean grain size of Garolim Bay surface sediments ranged from 0.51-5.58 Ø (mean 3.98 Ø) and increased from the inlet of bay to the inner bay, and from the waterway to the land. Most of the metal concentrations except for some elements showed the similar distribution to those of mean grain size and specific surface area. As the particle size decreased and the specific surface area increased, the metal concentration increased. In order to estimate the factors controlling the concentration of trace metals, factor analysis was performed, and three factors were extracted (92.7% of the total variation). Factor 1 accounted for 71.3% of the total variation, which was a grain size factor. Factor 2 accounted for 14.2% of the total variation, Factor 3 accounted for 7.2% of the total variance. Enrichment factor was calculated using the particle size corrected background concentration. Metals with a enrichment factor of 1.5 or higher and the number of samples were 4 for Cr (St. 1, 16, 27, 39) and 1 for Pb (St. 39), but there were little differences in the concentrations of 1M HCl leached metals for these metals. The percentage of 1M HCl leached fraction to total metal concentration decreased in the order of Pb~Co>Cu>Zn~Mn>Ni>Cr. Comparing this value with contaminated and clean sediments in other coastal areas, the percentages for each metal were similar regardless of the trace metal levels in all regions. This fact might be resulted from the reaction between the 1M HCl solution and the different sediment constituents, indicating that there is a limit to apply this percentage of leached metal to the estimation of the contamination extent.

• Tuberculosis and Respiratory Diseases
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• v.59 no.4
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• pp.397-405
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• 2005

Background : Laminin-1 is known to have regular functions in the development and course of differentiation of the lungs. The morphogenesis and distribution of laminin-1 still remains as a mystery and its distribution and changes in the molecular structure of laminin-1 in the pathogenesis of the lung still is a subject of great controversy. In this study, experiments were done to delineate the distribution and changes in the amount of laminin-1 after inducing inflammation of the lungs by exposing experimental animals to CS gas and especially, to find compositions of laminin-1 within type II pneumocytes. Materials and Methods : The experimental subjects of study were newborn rats and the extracted tissue from the experimental rats were viewed under light microscope and electron microscope after the sections were treated with immunohistochemical methods and immunogold reaction methods using bounded gold particles. Results : 1) Lymphocytes and mononuclear phagocytes invaded the alveolar septa in the 2 day group rats after CS gas exposure and intense interstitial inflammation was seen in the 3 day group. 2) Laminin immunoreactions decreased to a moderate degree in the 2 and 3 day group rats after CS gas exposure and strong laminin immunoreactions were seen again in the 5 and 7 day group rats. 3) Gold particles in basal lamina of the lung blood-air barrier decreased and in the type I pneumocytes decreased in the 2 and 3 day group rats after CS gas exposure. 4) Gold particles were seen only on the surface of the cell membranes of type II pneumocytes of the 1 and 2 day group rats after CS gas exposure. 5) Few gold particles around the lamellar bodies and cytoplasm of type II pneumocytes in the control rat group and at 12 hours after CS gas exposure. Gold particles are seen only on the surface of type II pneumocytes of the 1 and 2 day group rats after CS gas exposure and are evenly distributed in small amounts in the cells of the 3 day group after CS gas exposure. Conclusion : CS gas exposure in the rats caused inflammation of lung alveolar septa and also induced a decrease in laminin-1 in basal lamina and loss of laminin-1 in the cytoplasm of type II pneumonocytes. As the inflammatory cells disappeared, an increase in the distribution of laminin-1 occurred. This reflects tissue regeneration functions of laminin-1 in the pneumocytes of rats and the distribution of laminin-1 in type II pneumocytes can be seen through the electron microscope using immunogold methods.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.5
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• pp.619-625
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• 2005

This study has been carried out to examine the characteristics of anti-H. pylori antibodies of milk produced from cows immunized with antigen of Helicobacter pylori such as peculiarity of antigen antibody, agglutination of H. pylori strain, stability of antibody against acid, alkali and heat treatments. The molecular weight of anti-H. pylori antibody measured by SDS-PAGE were turned out as about 50 kDa in the heavy chain and about 24 kDa in the light chain. Twenty protein bands were visualized in H. pylori interacting with anti-H. pylori antibody which was made in dairy cow by immunization with H. pylori. The western blotting was peformed in order to examine the antigen peculiarity of anti-H. pylori, The results were all 7 antigen substances including serum, furified serum, whey and furified whey could be confirmed and the major antigen substances were 97, 66,34 kDa of molecular weight. As a result of agglutination response anti-H. pylori antibody in whey showed 1/10 agglutination value against H. pylori. In stability test about acid and alkali of antibody, there was $100\%$ activated at the range of $pH5\~pH10$. In stability test about heat, the antibody showed stable condition at $60^{\circ}C$ for 60 minutes and comparatively stable condition at $70^{\circ}C$, but reduced activation to $40\%$ after 60 minutes. It maintained $77\%$ activation at $80^{\circ}C$ for 4 minutes and comparatively stable at $100^{\circ}C$ for 1 minute.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.22 no.3
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• pp.118-134
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• 2017

The radiation observation data will be used importantly in research field such as climatology, weather, architecture, agro-livestock and marine science. The Ieodo Ocean Research Station (IORS) is regarded as an ideal observatory because its location can minimize the solar radiation reflection from the surrounding background and also the data produced here can serve as a reference data for radiation observation. This station has the potential to emerge as a significant observatory and join a global radiation observation group such as the Baseline Surface Radiation Network (BSRN), if the surrounding of observatory is improved and be equipped with the essential radiation measuring instruments (pyaranometer and pyrheliometer). IORS has observed the solar radiation using a pyranometer since November 2004 and the data from January 1, 2005 to December 31, 2015 were analyzed in this study. During the period of this study, the daily mean solar radiation observed from IORS decreased to $-3.80W/m^2/year$ due to the variation of the sensor response in addition to the natural environment. Since the yellow sand and fine dust from China are of great interest to scientists around the world, it is necessary to establish a basis of global joint response through the radiation data obtained at the Ieodo as well as at Sinan Gageocho and Ongjin Socheongcho Ocean Research Station. So it is an urgent need to improve the observatory surrounding and the accuracy of the observed data.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.3
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• pp.313-331
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• 2022

Natural or native abiotic molecular hydrogen (H₂) is a major component in natural gas, however yet its importance in the global energy sector's usage as clean and renewable energy is underestimated. Here we review the occurrence and geological settings of native hydrogen to demonstrate the much widesprease H₂ occurrence in nature by comparison with previous estimations. Three main types of source rocks have been identified: (1) ultramafic rocks; (2) cratons comprising iron (Fe²⁺)-rich rocks; and (3) uranium-rich rocks. The rocks are closely associated with Precambrian crystalline basement and serpentinized ultramafic rocks from ophiolite and peridotite either at mid-ocean ridges or within continental margin(Zgonnik, 2020). Inorganic geological processes producing H₂ in the source rocks include (a) the reduction of water during the oxidation of Fe²⁺ in minerals (e.g., olivine), (b) water splitting due to radioactive decay, (c) degassing of magma at low pressure, and (d) the reaction of water with surface radicals during mechanical breaking (e.g., fault) of silicate rocks. Native hydrogen are found as a free gas (51%), fluid inclusions in various rock types (29%), and dissolved gas in underground water (20%) (Zgonnik, 2020). Although research on H₂ has not yet been carried out in Korea, the potential H₂ reservoirs in the Gyeongsang Basin are highly probable based on geological and geochemical characteristics including occurrence of ultramafic rocks, inter-bedded basaltic layers and iron-copper deposits within thick sedimentary basin and igneous activities at an active continental margin during the Permian-Paleogene. The native hydrogen is expected to be clean and renewable energy source in the near future. Therefore it is clear that the origin and exploration of the native hydrogen, not yet been revealed by an integrated studies of rock-fluid interaction studies, are a field of special interest, regardless of the presence of economic native hydrogen reservoirs in Korea.

• Journal of Life Science
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• v.34 no.7
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• pp.500-508
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• 2024

Recently, there has been increasing interest in enhancing the indoor air quality, particularly in response to the growing utilization of public facilities. The focus of this study was on assessing the efficacy and safety of an air sterilizer equipped with electrolytic salt catalysts. To that end, we evaluated the antimicrobial activity of the vapor spraying from the air sterilizer and its cytotoxicity in condensed form on human cell lines (HaCaT, BEAS-2B, and THP-1). Against the test organisms, which comprised five bacterial strains (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium) and one fungal strain (Candida albicans), the air sterilizer exhibited relatively high antimicrobial activities ranging from 10.89 to 73.98% following 1 and 3 hr of vapor spraying, which were notably time-dependent. Importantly, cytotoxicity assessments on human cells indicated no significant harmful effect even at a 1.0% concentration. Comprehensive safety evaluations included morphological observations, gene expression (Bcl-2, Bax) tests, and FACS analysis of intracellular ROS levels. Consistent with previous cytotoxicity findings, these estimates demonstrated no significant changes, highlighting the air sterilizer's safety and antimicrobial activities. In a simulated 20-hr operation within an indoor environment, the air sterilizer not only showed an 89.4% removal of total bacteria but also a 100.0% removal of Escherichia sp. and fungi. This research outlines the potential of the developed electrolytic salt catalyst air sterilizer to effectively remove indoor microbial pollutants without compromising human safety, underscoring the solution that it offers for improving indoor air quality.