• Journal of the Korean Society of Combustion
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• v.4 no.1
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• pp.27-38
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• 1999

We constructed a wire-cylinder type pulsed corona discharge system for $NO_x$ removal, which was operated in room temperature. A emission spectrometer was built with a boxcar averager and monochrometer equipped with photo-multiplier tube detector. The sensitivity of the emission spectrometer was greatly improved by synchronizing the emission spectrometer with pulsed corona discharge system using a triggered spark-gap switch. $N_2$ spectrum($c^3{\Pi}_u{\rightarrow}X^1{\Sigma}_g{^+}$) was measured in the range of 300 - 450 nm and oxidizing OH radical emission($A^2{\Sigma}^+{\rightarrow}X^2{\Pi}$) was measured in case $N_2$ was supplied with water bubbling. As wet gas composition of inlet $N_2$ supplied in the discharge system increased, the intensity of OH emission was increased and saturated at wet gas composition 50%. We also investigated additive effect of $C_2H_4,\;H_2O,\;H_2O_2$ on the intensity of OR emission and $NO/NO_2/NO_x$ reduction and analysed the related reaction mechanism in corona discharge process. $H_2O_2$ additive increased the intensity of OH emission and $NO/NO_x$ reduction.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.2
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• pp.408-412
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• 2004

For the evaluation of immunomodulatory effect of Korean Oldenlandiae Herb (OH) and Radix (OR), our experiment was performed with methanol extracts of Korean Oldenlandiae Herba and Radix. After administration of methanol extracts of Korean OH and OR for 7 days, Balb/C mice were immunized with sheep red blood cells. Four days later, splenic leukocytes were isolated and immunological experiments were performed. Rosette forming cells and plaque forming cells were significantly increased in Korean OH and OR treated mice compared with PBS treated control. Korean OH and OR also enhanced T and B lymphocytes, macrophage and natural killer cells by flowcytometric analysis. LPS-induced TNF-α and IL-6 levels were increased by OH and OR compared with untreated control. These results suggest that Korean OH and OR have immunomodulatory activity through regulation of cell-mediated immune and humoral immune response.

• Journal of Applied Biological Chemistry
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• v.56 no.3
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• pp.171-177
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• 2013

Efficient extraction of total proteins from soil microorganisms is tedious because of small quantity. In this regard, an improved method for extraction of whole cell proteins is developed from soil microorganisms, Saccharomyces cerevisiae and Pichia pastoris. of which the cell wall are very strong. Pretreatment with NH4OH prior to the final extraction using NaOH/SDS was tried under the basis that ammonium ion was possible to enhance the permeability and/or to weaken the yeast cell walls. The pre-treatment of yeast cells with NH4OH drastically enhanced the protein extraction when it was compared with control (without NH4OH pre-treatment). At the pre-treatment of 0.04 N NH4OH at pH 9.0, about 3 fold of proteins was obtained from p. pastoris. Ammonium hydroxide appears to penetrate into the yeast cell walls more readily at basic pH. The effect of NH4OH pretreatment was pH dependent. The methods developed in this experiment might be applicable for an effective extraction of yeast proteins for the purpose of biochemical studies, especially proteomic analysis.

• Korean Journal of Medicinal Crop Science
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• v.15 no.5
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• pp.329-334
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• 2007

The potential antioxidant and anticancer activities of Hexane, EtOAc (Ethyl acetate), BuOH (n-Buthanol) and water fractions from methanolic (MeOH) extract of Picrasma quassioides (D. Don) Benn. were evaluated in vitro. Tested fractions showed strong antioxidant activity, especially EtOAc fraction had the highest activity ($IC_{50}\;=\;114.01\;{\mu}g/mL$), containing high total phenolics and total flavonoids contents, showed $67.59\;Tan\;{\mu}g/mg$ and $64.95\;Que\;{\mu}g/mg$ respectively. Anticancer activity of these fractions was tested by MTT assay on HT-29 (the human colon carcinoma cells) cell line. BuOH fraction not only showed very high anticancer activity, but also had no cytotoxic effect on 293 (the human normal kidney cells) cell line. Considering these results, we used BuOH fraction of MeOH crude extract from P. quassioides (D.Don) Benn. to do assessment of apoptosis by flow cytometry and the mRNA expression levels of widely established apoptotic-related genes on HT-29 cell line. All the experiments showed that BuOH fraction can induce apoptosis on HT-29 cell line strongly. Taken together, methanolic extract of P. quassioides has potential for antioxidant and anticancer activities products.

• Bulletin of the Korean Chemical Society
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• v.35 no.6
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• pp.1706-1712
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• 2014

The OH($X^2{\Pi}$, ${\upsilon}^{\prime\prime}=0,1$) internal state distribution following the reaction of electronically excited oxygen atom ($O(^1D_2)$) with cyclo-$C_3H_6$ has been measured using laser-induced fluorescence, and compared with that following the reaction of $O(^1D_2)$ with $C_3H_8$. The overall characteristics of the OH internal energy distributions for both reactions were qualitatively similar. The population propensity of the ${\Pi}(A^{\prime})$ ${\Lambda}$-doublet sub-level suggested that both reactions proceeded via an insertion/elimination mechanism. Bimodal rotational population distributions supported the existence of two parallel mechanisms for OH production, i.e., statistical insertion and nonstatistical insertion. However, detailed analysis revealed that, despite the higher exoergicity of the reaction, the rotational distribution of the OH following the reaction of $O(^1D_2)$ with $C_3H_8$ was significantly cooler than that with cyclo-$C_3H_6$, especially in the vibrational ground state. This observation was interpreted as the effect of the flexibility of the insertion complex and faster intramolecular vibrational relaxation (IVR).

• Korean Journal of Crystallography
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• v.12 no.2
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• pp.97-101
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• 2001

Phillipsite-type zeolite powders were synthesized from domestic coal fly ash by hydrothermal reaction with 2.0 M-3.5M NaOH solution at $80^{\circ}C{\sim}120^{\circ}C$ for 24 h. The properties of zeolite were investigated by XRD, SEM and IR spectroscopy. The effects of chemical composition of fly ash, reaction temperature and NaOH concentration on the zeolite synthesis were well appeared on IR spectra. It is found that the $TO_4$(T=Si, Al) tetrahedra have a well ordered structure as the $SiO_2$ content, synthesis temperature and NaOH concentration become high.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2283-2288
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• 2010

Nanostructured copper compounds were grown by electrochemical anodization of copper foil in aqueous NaOH under varying conditions including electrolyte concentration, reaction temperature, current density, and reaction time. Their morphology and atomic composition were investigated by using SEM, TEM, XRD, EDS and XPS. At the conditions ([NaOH] = 1 M, $20^{\circ}C$, $2\;mA\;cm^{-2}$), wire-like orthorhombic $Cu(OH)_2$ nanobundles with an average width of 100 - 300 nm and length of $10\;{\mu}m$ were synthesized with the preferential [100] growth direction. Furthermore, when the concentration decreased to 0.5 M NaOH, the 1D nanobundle structure became narrower and longer without any change in compositions or crystalline structure. Side reaction pathways appeared to compete with the 1D nanostructure formation channels: the formation of CuO nanoleaves at $50^{\circ}C$ via the sequential dehydration of $Cu(OH)_2$, CuO/$Cu_2O$ aggregates in 4 M NaOH, and $Cu_2O$ nanoparticles and CuO nanosheets at lower current density.

• Journal of The Korean Astronomical Society
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• v.46 no.6
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• pp.235-242
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• 2013

We compare mass-loss rates of OH/IR stars obtained from radio observations with those derived from the dust radiative transfer models and IR observations. We collect radio observational data of OH maser and CO line emission sources for a sample of 1533 OH/IR stars listed in Suh & Kwon (2011). For 1259 OH maser, 76 CO(J=1-0), and 55 CO(J=2-1) emission sources, we compile data of the expansion velocity and mass-loss rate. We use a dust radiative transfer model for the dust shell to calculate the mass-loss rate as well as the IR color indices. The observed mass-loss rates are in the range predicted by the theoretical dust shell models corresponding to $\dot{M}=10^{-8}M_{\odot}/yr-10^{-4}M_{\odot}/yr$. We find that the dust model using a simple mixture of amorphous silicate and amorphous $Al_2O_3$ (20% by mass) grains can explain the observations fairly well. The results indicate that the dust radiative transfer models for IR observations generally agree with the radio observations. For high mass-loss rate OH/IR stars, the mass-loss rates obtained from radio observations are underestimated compared to the mass-loss rates derived from the dust shell models. This could be because photon momentum transfer to the gas shell is not possible for the physical condition of high mass-loss rates. Alternative explanations could be the effects of different dust-to-gas ratios and/or a superwind.

• Journal of the Korean Ceramic Society
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• v.26 no.1
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• pp.100-108
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• 1989

Aluminum hydroxides were prepared by the alkoxide hydrolysis method using Al-isopropoxide as a starting material and NH4OH as a catalytic agent. When Al-isopropoxide was hydrolyzed in a H2O-NH3 system, only Al(OH)3 was obtained over all pH values. However, AlOOH was formed besides Al(OH)3 when Al-isopropoxide was hydrolyzed in a H2O-NH3-isopropyl alcohol system. The AlOOH/Al(OH)3 ratio was increased as the isopropyl alcohol content was increased. The hydroxides, Al(OH)3 and AlOOH, obtained in this study and the commerical products, $\alpha$-Al2O3 and AlOOH were subjected to the carbothermal reduction and nitridation reaction to product AlN powder, using carbon black as a reducing agent under N2 atmosphere at various temperatures. AlN was synthesized from the obtained Al(OH)3 and the commercial AlOOH at 145$0^{\circ}C$, however, synthesized from the obtained AlOOH and the commercial alpha-alumina at 135$0^{\circ}C$. The temperature difference is assumed to be attributed to the reactivity of those powders. AlN powder prepared from the Al-isopropoxide was observed to have the narrower particle size distribution than that prepared from the commercial $\alpha$-Al2O3 or AlOOH.

• The Korean Journal of Community Living Science
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• v.27 no.3
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• pp.343-350
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• 2016

The antioxidant activity was examined on ultra-fine powdered (UFP) Ulmus davidiana (U. davidiana) var. japonica. The average particle size of UFP or commercial powdered (CP) was $1-3{\mu}m$ or $100{\mu}m$. The extraction was performed using either ethanol (EtOH) or hot-water. Contents of phenolic compound of CP and UFP U. davidiana extracts in EtOH was 40.38 and 65.61 mg/g, respectively. In DPPH, EtOH extract of UFP U. davidiana showed a significantly greater activity than hot-water extract at 40 and $200{\mu}g/mL$. At $200{\mu}g/mL$, the activity was over 90% in all groups. The reducing power of UFP U. davidiana var. japonica in EtOH extraction was 74.3%, which was significantly greater than in other samples (p<0.05). In addition, reducing powder was significantly higher in UFP-EtOH than in other samples at all concentrations except for $0.32{\mu}g/mL$. The above results suggest that EtOH extraction of U. davidiana showed slightly higher DPPH radical scavenging activity, and ultra-fine powder of U. davidiana extracts may show higher antioxidative activities based on reducing power.