• Natural Product Sciences
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• v.14 no.2
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• pp.86-89
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• 2008

Phytochemical study of the aerial parts of Lotus lalambensis Schweinf resulted in the isolation and identification of two new flavonol glycosides; kaempferol $3-O-(5"-acetyl)-apioside-7-O-{\alpha}-L-rhamnopyranoside$ (1) and kaempferol $3-O-{\alpha}-[{\beta}-D-xylosyl-(1""{\rightarrow} 2")-L-rhamnopyranoside]-7-O-{\alpha}-L-rhamnopyranoside$ (2). Structures were determined utilizing different physical, chemical, spectroscopic data including 2D-NMR experiments and HRFABMS.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.1
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• pp.1-9
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• 1991

This paper describes a new method of calculating expected energy generation and loss of load probability (L.O.L.P) for electric power system operation and expansion planning. The method represents an equivalent load duration curve (E.L.D.C) as a mixture of cumulants approximation (M.O.N.A). By regarding a load distribution as many normal distributions-rather than one normal distribution-and representing each of them in terms of Gram-Charlier expansion, we could improve the accuracy of results. We developed an algorithm which automatically determines the number of distribution and demarcation points. In modeling of a supply system, we made subsets of generators according to the number of generator outage: since the calculation of each subset's moment needs to be processed rapidly, we further developed specific recursive formulae. The method is applied to the test systems and the results are compared with those of cumulant, M.O.N.A. and Booth-Baleriaux method. It is verified that the M.O.C.A. method is faster and more accure than any other method.

• Korean Journal of Microbiology
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• v.12 no.1
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• pp.31-36
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• 1974

Four strains of yeasts were chosen from those isolated previously, and a strain from 160 isolates collected in this year were examined for the treatment of pulp waste liquor. Experiments about optimum nutrient condition, composition of cells, and reduction of B.O.D. on the "S" pulp industry waste liquor were performed with 5 strains. 1. The isolates(strain 112) was identified as Candida utilis. 2. The optium concentration of 4 components of nutrients were ($NH_4$)$SO_2$lg/l, yeast extract 70mg/l, $KH_2PO_4$ 300mg/l, and $MgSO_4{\ddot}7H_2O$ 500mg/l. 3. Specific growth ratio of Candida utilis KYRI 112 was 0.48/hr at optimum nutrient media and the yield was 0.45%(V/V). 4. Endomycopsis capsularis KYRI 613 contained more crude protein than the most of commercial yeasts. 5. The B.O.D. of waste liquor was reduced ro 20% of its value by the culture.e culture.

• Korean Journal of Dental Materials
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• v.45 no.4
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• pp.233-242
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• 2018

The purpose of this study is to evaluate the effect of resin cement color on the color of commercially available zirconia crown. The zirconia and resin cements used for the experiment were $NuSmile^{(R)}$ ZR Zirconia LT Shade (LT), $RelyX^{TM}$ U200 TR, A2, and A3O (TR, A2, A3O). The disks of zirconia and resin cements with diameters of 5 mm and thicknesses of 1 mm were prepared. Five disks were made for each specimen. The CIE $L^*a^*b^*$ values of zirconia, resin cements and the combinations thereof were measured on black and white backgrounds, respectively, using a spectrophotometer. The color effect of resin cement on the color of the zirconia crown was evaluated by calculating translucency parameter (TP), contrast ratio (CR), and color differences (${\Delta}E{^*}_{ab}$) based on the measured CIE $L^*a^*b^*$ values. The statistical significances were verified by one-way ANOVA and the Tukey-multiple comparisons tests. As a result, the TP and CR values were decreased (p<0.05) and increased, respectively, in the combination of zirconia and resin cement disks compared to zirconia disk per se. When using the black background, the ${\Delta}E{^*}_{ab}$ values between zirconia and the combination of the zirconia and three resin cement disks were imperceptible level. The A3O showed the lowest ${\Delta}E{^*}_{ab}$ value among three resin cements. When using the white background, the ${\Delta}E{^*}_{ab}$ values between zirconia and the combination of zirconia and TR resin cement (LT/TR) disks showed acceptable level. However, the ${\Delta}E{^*}_{ab}$ values between zirconia and the combination of zirconia and A2 resin cement (LT/A2) disks showed unacceptable level. Meanwhile, the ${\Delta}E{^*}_{ab}$ values between zirconia and the combination of zirconia and A3O resin cement (LT/A3O) disks showed perceptible but acceptable level. Within the limits of this study, the colors of resin cements did not cause unacceptable color changes of zirconia except the combination of LT/A2 on the white background. The resin cement that gave the least color changes to zirconia was A3O. This means that the resin cement A3O is recommended to use for minimizing color changes when cementing commercially available zirconia crown to tooth.

• Journal of Microbiology and Biotechnology
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• v.9 no.4
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• pp.398-403
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• 1999

In our previous studies, we reported that hybridoma B-lymphocytes can be used to determine the virulence of Listeria species in an in vitro cytotoxicity assay. Here, we examined the cytopathic effect, i.e., membrane damage and the nature of cell death induced by Listeria monocytogenes on murine hybridoma B-lymphocytes (Ped-2E9). Membrane damage was assessed by microscopic analyses and by measuring the release of intracellular alkaline phosphatase(AP) and lactate dehydrogenase (LDH). Cell death was determined by DNA fragmentation analyses using agarose gel electrophoresis. Infection by listeriolysin O (LLO)-producing L. monocytogenes strains induced substantial amounts of AP and LDH release from Ped-2E9 hybridoma B-cells, suggesting severe membrane damage in these cells, while an LLO-negative L. monocytogenes mutant strain had no effect. An LLO-producing recombinant L. innocua ($prifA^+hly^+$) strain also induced high AP and LDH release and cytopathic changes in Ped-2E9 cells. Light or scanning electron microscopic examination revealed L. monocytogenes mediated membrane destabilization, pore formation, intense cytoplasmic granulation, bleb formation, and lysis of Ped-2E9 cells. LLO-producing L. monocytogenes and L. innocua ($prifA^{+}hly{^}+$) also induced ladder-like DNA fragmentation in Ped-2E9 cells. Collectively, these results suggest that L. monocytogenes, specifically LLO-producing strains, can induce a severe cytopathic effect leading to apoptosis in hybridoma B-lymphocytes (Ped-2E9).

• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.30-37
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• 2005

To mass-produce useful biopolymer films, chitosan/gelatin blend films were prepared by solution casting method. Effects of mixing ratio, tensile strength (TS), elongation (E) at break, total color difference (${\Dalta}E$), opacity, water vapor permeability (WVP), oxygen permeability (OP), and thermal properties on chitosan/gelatin blend films properties were investigated. TS, E, ${\Dalta}E$, opacity, WVP, and OP values were 58.24-22.01 MPa, 13.11-24.67%, 1.86-17.45, 0.3104-1.2161 nmO.D./${\mu}m$, $1.6875-1.7225ng{\cdot}m/m^{2}{\cdot}s{\cdot}Pa$, and $2.2380{\times}10^{-7}-2.2975{\times}10^{-7}\;mL{\cdot}{\mu}m/m^{2}{\cdot}s{\cdot}Pa$, respectively. TS of blend films decreased, while E, ${\Dalta}E$, and opacity increased with increasing chitosan content. WVP of blend films did not show any significant relationship with mixing ratio and thickness of blend films. Miscibility of films was examined over entire composition range by thermogravimetric analyzer (TGA) and dynamic mechanical analyzer (DMA). TGA results showed gelatin is more thermally stable than chitosan and some interactions among functional groups of two biopolymers. Glass transition temperature $(T_{2})$ of films as determined by DMA decreased with increasing content of chitosan in the blend. Results of thermal analysis indicate high miscibility among polymer components in the blend.

• Journal of Korean Society for Atmospheric Environment
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• v.11 no.3
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• pp.245-252
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• 1995

Atmospheric aerosols were collected by a High Volume Tape Sampler from March 1992 to December 1993 ar Korean, Cheju, Korea. The water soluble ion concentrations in aerosol were analyzed. The concentrations of cations (N $a^{+}$, $K^{+}$, $Ca^{2+}$, $Mg^{2+}$, N $H_{4}$$^{+}$) were determined by an Inductively Coupled Plazma(ICP) or an Atomic Absorption Spectrometer(AAS), and those of anions (C $l^{[-10]}$ , N $O_{3}$$^{[-10]}$ , S $O_{4}$$^{2-}$) were analayzed by the capillary electrophoresis method. The $Ca^{2+}$, S $O_{4}$$^{2-}$ and N $O_{3}$$^{[-10]}$ concentrations in spring were higher than those in other seasons. The lowest concentrations of these elements were found in summer, largely due to scavenging by frequent rains. Especially the $Ca^{2+}$ concentration on April was three to four times higher than the annual mean concentration. The enrichment factor(E.F.) of each element was calculated. The annual mean E.F. values of the $Ca^{2+}$, $Mg^{2+}$ and C $l^{[-10]}$ in 1992 were the same as those in 1993 except $k^{+}$ and S $O_{4}$$^{2-}$. The correlation formula between all cations and anions for the whole period was Anions = 0.759 * Cations + 0.066.Cations + 0.066.

• Journal of Biosystems Engineering
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• v.38 no.4
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• pp.335-340
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• 2013

Purpose: This study was performed to develop a lateral flow strip sensor for the detection of pathogenic Escherichia coli O157:H7 in various samples. Also, feasibility of using an image analysis method to improve the interpretation of the strip sensor was evaluated. Methods: The lateral flow strip sensor has been fabricated based on nitrocellulose lateral-flow membrane. Colloidal gold and E. coli O157:H7 antibodies were used as a tag and a receptor, respectively. Manually spotted E. coli O157:H7 antibody and anti-mouse antibody on nitrocellulose membrane were used as test and control dots, respectively. Feasibility of the lateral flow strip sensor to detect E. coli O157:H7 were evaluated with serially diluted E. coli O157:H7 cells in PBS or food samples. Test results of the lateral flow strip sensor were measured with an image analysis method. Results: The intensity of the test dot started to increase with higher concentration of the cells were introduced. The sensitivities of the sensor were both $10^4$ CFU/mL Escherichia coli O157:H7 spiked in PBS and in chicken meat extract, respectively. Conclusions: The lateral flow strip sensor and image analysis method could detect E. coli O157:H7 in 20 min, which is significantly quicker than conventional plate counting method.

• KSBB Journal
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• v.11 no.3
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• pp.367-373
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• 1996

The growth characteristics of Rhodotorula sp. Y-55 were examined on minimal medium containing ethanol, acetic acid or acetadehyde as a sole carbon source by batch culture. The increased concentration of substrate reduced overall growth yield and prolonged lag time. The specific growth rate of the yeast was changed, depending upon the initial concentrations of ethanol and acetaldehyde during the exponential period, but was constant on acetic acid without regard to the initial substrate concentrations, giving a value of 0.l07h-1. The highest ${\mu}$ value was obtained on ethanol and acetadehyde substrates and the respective values were 0.270 at 20g/L and 0.041h-1 at 0.2g/L. The maximum overall growth yields were appeared to be 32.6% for ethanol of 10g/L, 25.6% for acetic acid of 20g/L, and 45% for acetaldehyde of 0.2g/L. The respective cellular contents of crude protein and nucleic acids were determined to be 41.5 and 4.9wt% on ethanol and 40.2 and 4.7wt% at the concentration revealing maximal growth yield.

• Journal of Korean Society on Water Environment
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• v.33 no.6
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• pp.736-743
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• 2017

In this study, 4-nonylphenol (4-NP), an endocrine disrupting chemical, was removed by ozone treatment processes under the various experimental conditions including UV irradiation, $TiO_2$ addition. The ozone flow rate and concentration were maintained at $1.0L{\cdot}min^{-1}$ and $70{\pm}5mg{\cdot}L^{-1}$. The pH, COD and TOC of the samples were obtained every 10 minutes for 60 minutes in laboratory scale batch reactor. We found that the combination of UV irradiation and $TiO_2$ addition for ozonation improves the removal efficiency of COD and TOC in 4-NP aqueous solution. In case of the $O_3/UV/TiO_2$ system, COD and TOC were greatly reduced to 85.3 ~ 94.0% and 89.2 ~ 97.2%, respectively. 4-NP degradation rate constants, $k_{COD}$ and $k_{TOC}$, were calculated based on the COD and TOC values. Significantly, $k_{COD}$ and $k_{TOC}$ were improved in the $O_3/UV/TiO_2$ treatment process compared with single $O_3$ process, because the oxidation and the mineralization of 4-NP were increased by generating of the hydroxyl radical. The $k_{COD}$ and $k_{TOC}$ were obtained to be $5.81{\times}10^{-4}{\sim}10.8{\times}10^{-4}sec^{-1}$ and $11.9{\times}10^{-4}{\sim}19.4{\times}10^{-4}sec^{-1}$ in the $O_3/UV/TiO_2$ process. Activation energy ($E_a$) of ozone oxidation reaction based on $k_{COD}$ and $k_{TOC}$ were increased in order of $O_3/UV/TiO_2$ < $O3/UV$ < $O_3/TiO_2$ < $O_3$ process. It was confirmed that the addition of $TiO_2$ and UV irradiation to the ozone oxidation reaction significantly reduced the $E_a$ value and the degradation of 4-NP.