• Journal of Korean Society for Atmospheric Environment
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• v.20 no.6
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• pp.833-838
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• 2004

The analysis of Pb in both PM$_{2.5}$ and PM$_{10}$ fraction of aerosols was made consecutively for every spring season during four year period of 2001 through 2004. To diagnose the impact of the Asian Dust (AD) on metal concentration levels, we compared our Pb measurement data after dividing the whole data sets into AD and NAD period. The results of our analysis indicated that the concentrations of coarse particles increased significantly during the AD period, whereas an increase in the fine counterpart was of moderate degree. However, when Pb concentrations between AD and NAD were compared, the patterns were quite different. From all particle fractions, the Pb concentrations of NAD were slightly or moderately higher than those of AD. The overall results of our study suggest that an increase in particle concentrations during the AD period can cause a rather slight reduction in Pb concentration levels; this can be explained by the dilution effect associated with the increase of Pb-depleted coarse particles.s.s.

• Korean journal of food and cookery science
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• v.26 no.6
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• pp.848-852
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• 2010

This study investigated the antibacterial activities of extracts and fractions of Sasa borealis against eight bacteria (Bacillus cereus, Bacillus subtilis, Listeria monocytogenes, Staphylococcus aureus, Psedomonas aerginosa, Salmonella choleraesuis, Serratia marcescens and Vibrio vulnificus) by broth dilution assay. Using survival curves, the kinetics of bacterial inactivation upon exposure to the extracts and fractions were followed for 24 h. In this same manner, MIC (minimum inhibitory concentration) values were determined by broth microdilution assay and then confirmed to be the extract concentrations that inhibited bacterial growth. Sasa borealis extracts showed antibacterial activities against all tested bacteria. In particular, all tested fractions of Sasa borealis had stronger activities than 70% ethanol extract. MIC of Sasa borealis extract was determined to be 5 mg/mL against Salmonella choleraesuis. All fractions of Sasa borealis extract had extremely strong antibacterial activities. MIC of fractions were determined to be 0.03~2.5 mg/mL. These results suggest that the extracts and fractions of Sasa borealis effectively inhibited bacterial growth and thus are useful as natural antibacterial agents.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1763-1765
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• 2000

This paper presents deposition and characterizations of microcrystalline silicon ($\mu$ c-Si:H) films prepared by hot wire chemical vapor deposition at substrate temperature at 300$^{\circ}C$. The flow rates of $SiH_4$ gas are critical parameter for the formation of Si films with microcrystalline phase. We could obtain $\mu$ c-Si:H with columnar grain structure and volume fraction of 75% without H2 dilution. The electronic properties, hydrogen bonding configurations, and $H_2$ concentration inside the films are also strongly affected by $SiH_4$ flow rate, which is provided in this paper.

• Journal of the Korean Wood Science and Technology
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• v.44 no.1
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• pp.113-123
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• 2016

This study was to investigate the antifungal activity of A. holophylla essential oil against dermatophytes, such as Epidermophyton floccosum, Trichophyton mentagrophytes and Trichophyton rubrum, and to determine the potential effective compound as dermatitis treatment. To evaluate the potential antifungal activities of A. holophylla essential oil and its fractions, paper disc diffusion and agar dilution method tested with morphological observation. Also, their major constituents were analyzed by GC/MS. To determine synergic effects of active ingredient from A. holophylla essential oil were carried out by checkerboard microtiter plate testing. The morphological changes of the dermatophytes exposed to active fraction G4 were observed by electron microscopes. As the results, the highest activities were identified in the fraction containing ${\alpha}$-bisabolol. A mixture of ${\alpha}$-bisabolol and bornyl acetate showed the synergy effects, expressing high potential effects. Also, morphological observation using electron microscopes showed a dramatic changes of cell membrane of E. floccosum and T. rubrum exposed to fraction G4 containing ${\alpha}$-bisabolol. In conclusion, A. holophylla essential oil and its constituents were expected to be used as antifungal agent or raw material for dermatitis therapy.

• Korean Journal of Microbiology
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• v.40 no.4
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• pp.334-341
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• 2004

Polysaccharides were prepared from Orostachys japonicus by extration with hot steam water (OJPl). The OIPl fraction was further purified by Sephadex G-50 gel filtration chromatography to produce FI (polysaccharides) and FII (oligosaccharides) fraction. The average molecular masses o fFI and FII fraction were determined to be 3050 kDa and 13 kDa, respectively. The antimicrobial activity of OIPl was tested against 8 strains of bacteria and one strain of yeast by the disc diffusion method, fluorescein diacetate (FDA) method and broth dilution method. The OIPl exhibited a very strong growth inhibition to Candida albicans. The OIPl remarkably sup­pressed the growth of Salmonella typhimurium and Staphylococcus aureus. The OIPl showed higher growth inhibition to Escherichia coli and Pseudomonas aeruginosa than propolis, positive control. When the anticancer activity of the OIPl, FI or FII was examined against human cancer cell lines and the Sarcoma 180 cells, these widely suppressed the proliferation of cell lines in the MTT assay and morphology study. Especially, they remarkably inhibited the growth of A549, HeLa and AGS cells. Also treatment of cancer cells with OJPl, FI or FII induced apoptotic cell death characterized by DNA fragmentation. The OJPl, FI or FII exhibiting various biological activities such as antimicrobial activity and anticancer activity is expected to be developed as new biohealth products.

• Analytical Science and Technology
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• v.27 no.1
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• pp.34-40
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• 2014

SPLITT fractionation (SF) allows continuous (and thus a preparative scale) separation of micronsized particles into two size fractions ('fraction-a' and 'fraction-b'). SF is usually carried out in a thin rectangular channel with two inlets and two outlets, which is equipped with flow stream splitters at the inlet and the outlet of the channel, respectively. A new large scale splitter-less gravitational SF (GSF) system had been assembled, which was designed to eliminate the flow stream splitters and thus is operated by the full feed depletion (FFD) mode (FFD-GSF). In the FFD mode, there is only one inlet through which the sample is fed. There is no carrier liquid fed into the channel, and thus prevents the sample dilution. The effects of the sample-feeding flow rate, the channel thickness on the fractionation efficiency (FE, number % of particles that have the size predicted by theory) of FFD-GSF was investigated using industrial polyurethane (PU) latex beads. The carrier liquid was water containing 0.1% FL-70 (particle dispersing agent) and 0.02% sodium azide (used as bactericide). The sample loading rate was varied from about 4 to 7 L/hr with the sample concentration fixed at 0.01%. The GSF channel thickness was varied from 900 to $1300{\mu}m$. Particles exiting the GSF channel were collected and monitored by optical microscopy (OM). Sample recovery was monitored by collecting the fractionated particles on a $0.45{\mu}m$ membrane filter. It was found that FE of fraction-a was increased as the channel thickness increases, and FE of fraction-b was increased as the flow rate was increased. In all cases, the sample recovery has higher than 95%. It seems the new splitter-less FFD GSF system could become a useful tool for large scale separations of various types of micron-sized particles.

• Clinical and Experimental Reproductive Medicine
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• v.17 no.1
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• pp.71-80
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• 1990

New immunoassay systems for the detection of anti-sperm antibodies were developed. For this, sperm surface protein was purified by the immunoaffinity column prepared by the coupling of rabbit anti-human IgG antibodies to Sepharose-4B. Fraction eluted by tris-HCI buffer containing SDS showed a single band having molecular weight of about 60KD on electrophoresis. Enzyme HRP labelled goat anti-human IgG and chemiluminescence aminobutylethyl-isoluminol(ABEI) labelled rabbit anti-human IgG were used for ELISA and CIA, respectively. These two labelled conjugate bound well with human IgG. When serum dilution curves were made to titrate positive serums, two kinds of curves with steep and sluggish slopes were obtained Serum samples were categorized into 3 groups: positive, weak positive and negative based on slope of curve and O.D. values at 1:160 dilution of serum. When ELISA and CIA were compared to conventional method Kibrick test by the determinations of 62 male serums with different diagnosis, the results of ELISA and CIA agreed well, but both disagreed with that of Kibrick test. This study showed that purified sperm surface antigen can be used to develope solid-phase immunoassay systems such as ELISA and CIA which may eliminate the problems encounted the immobilization of living sperm in other tests.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1621-1621
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• 2001

The quality of sugarcane grown on the NE Australian tropical coast ($16^{\circ}$15'- $18^{\circ}$15' S Lat.) has declined markedly in the past seven years. This has been linked to dilution of mill-supply cane with increasing levels of non mature-stalk material consisting of leaves and sucker culms. The prime research objective was to examine the transition from the pre-harvest, in-field crop to harvested material sent for processing, in terms of quality and crop fraction proportions. A secondary objective was to quantify the effects of preharvest-season crop habit and culm condition on crop quality. Ten quadrat samples from each of 54 random crop sites (17 in 1999 and 37 in 2000), covering a wide range of variables (cultivar, crop class, and edaphic, topographic, climatic, and temporal factors) were collected immediately before harvest. Samples were partitioned into four fractions:- sound and unsound mature stalks (culms), sucker culms, and extraneous matter (leaves). Material harvested from each site was sampled and partitioned into four fractions:- sound and unsound billets (culm pieces), culm-spindle pieces, and leaf. In 2000, before harvest, 14 additional sites were sampled monthly, on three occasions, from March - June. Erect and non-erect culms were divided into sound and unsound classes. All samples were disintegrated and presented to a remote reflectance module of a scanning spectrophotometer using the BSES large cassette module. Near infra-red spectroscopic (NIS) analyses were developed for the rapid determination of quality components (Brix, commercial cane sugar (CCS), fibre, moisture, and polariscope reading). Calibrations for three material groups (culm (n = 639), non-culm (n = 496), and combined) were developed for all components using the 1999 data set. Two sub-sets (n = 178, and 190) of about 10% of the preharvest-season and harvest populations scanned in 2000 also were subjected to full routine laboratory analyses. The 1999 combined calibrations were excellent, but the culm calibrations produced consistently lower standard errors. Non-culm calibrations were marginally better than the combined for only CCS and pol. reading. Analysis of the 2000 culm data with calibrations using all 1999 and 2000 culm data resulted in better predictions relative to the 1999 culm calibrations. This also was true for the combined calibrations. Assessment of quality components in pre- and post-harvest sugarcane using NIS calibrations was more cost effective than using routine laboratory techniques. Outcomes from this NIS-facilitated research will have important economic consequences for the Australian sugarcane industry. Potential CCS present in mature culms is being discounted by dilution with leaves and sucker culms, threatening farm viability. The results question the efficacy of current harvesting technology. The CCS of harvested cane is improved only marginally over that of the in-field crop. Current harvesting technology requires either supplementary, innovative pre-mill processing or a design revolution to improve mill-supply cane quality, and therefore whole of industry economics. NIS-facilitated analyses, before the harvest season, highlighted the benefits of growing erect, sound crops. Loss of CCS then, can be minimized only by a combination of crop improvement and agronomic solutions, applied as part of sound on-farm management.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.16 no.4
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• pp.169-179
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• 2011

To investigate the controlling factor and accumulation of trace metal concentrations in Chun-su Bay sediments, grain-size, specific surface area, organic carbon content, calcium carbonate content, and concentration of Al, Fe, Na, K, Mg, Ca, Ti, Mn, P, S, Ba, Sr, Li, Co, Cr, Ni, Cu, Zn, As, Cd, Cs, Sc, V, Sn were analyzed. Controlling factors of metals were quartz-dilution, calcium carbonate and coarse sand or K-feldspar. Although the distribution of V, Co, Cr, Ni, Cu, Zn, Sn, and Cd concentration was explained by grain-size effiect, Mn and As showed the similar importance of grain-size effect and coarse sand or K-feldspar factors. By virtue of enrichment factor and 1 M HCl experiment, there were little enrichment in all the trace metals in bay sediments, which were explained well by geochemical properties of sediments. Since the concentration levels of As in coarse sand were high as much as those in fine-grained sediments and it was combined with Mn oxide (1 M HCl leached) and K-feldspar (residual), it was suggested that when the enrichment of As in sediments would be assessed, it is necessary to separate the coarse sand from bulk sediments or to use only sediments with higher than 10% in < $16{\mu}m$ fraction.

• Journal of the Korean Institute of Gas
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• v.25 no.2
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• pp.1-12
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• 2021

MILD(Moderate or Intense Low-oxygen Dilution) combustion has attracted attention as the clean thermal energy technology due to the lower emissions of unburnt carbon and NO_x. MILD combustion aims to enlarge the combustion reaction zone using the spontaneous ignition phenomenon of the reactants. In this study, the ignition delay time of CH₄ according to the initial temperature of reactants and the addition of CO, H₂ was investigated using a numerical approach. Ignition delay time became shorter as the increases of initial temperature and H₂ addition. But, CO addition to the fuel increase the ignition delay time. In case of H₂ addition to the fuel, the ignition delay time decreased because the higher fraction of HO₂ promotes the decomposition of methyl radical(CH₃) and produce OH radical. However, in case of CO addition to the fuel, ignition delay time inceased because a high proportion of HCO consumes H radical. There was no significant effect of HCO on the reduction of ignition delay time. Also, the increase rates of NO emissions by the addition of CO and H₂ were approximately 7% and 1%, respectively. A high proportion of NCO affects the increase in NO production rate.