• Bulletin of the Korean Chemical Society
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• v.35 no.5
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• pp.1469-1478
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• 2014

Use of acetonitrile in electrolytes promotes better operation of supercapacitors. Recent efforts show that electrolytes containing acetonitrile can also function in a wide range of operating temperatures. Therefore, this paper addresses the dielectric relaxation processes, structure and dynamic properties of the bulk acetonitrile at various temperatures. Systems of acetonitrile were modeled using canonical ensemble and simulated by employing Molecular Dynamics method. Results show that interactions among the molecules were correlated within a cut-off radius while parallel and anti-parallel arrangements are observed beyond this radius at relatively high and low temperatures respectively. Furthermore, effects of C-C-N and C-H bending modes were greatly appreciated on the power spectral density of time rate change of dipole-dipole correlations whereas frequency shifts were observed on all modes at the lowest temperature under consideration. Linear variations with temperature were depicted for reorientation times and self-diffusion coefficients. Shear viscosity was also computed with a good accuracy within a certain range of the temperature as well.

• BMB Reports
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• v.28 no.3
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• pp.238-242
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• 1995

The tadpole H-ferritin produced in E. coli was purified and its molecular properties were investigated to obtain information about the contribution of the H-subunit in the reaction of iron core formation. All the expressed subunits were assembled into complete holoprotein in vitro, presumably 24-mer, and the protein was heat-stable. Electron microscopy revealed that the recombinant ferritin forms spherically and contains iron core. No difference was observed in the absorption spectrum of the expressed protein compared to that of the natural ferritin. The Ouchterlony double diffusion of the expressed protein showed that the H-chain ferritin shares an antigenic determinant with natural tadpole ferritin. Rabbit anti-horse spleen ferritin discriminated the H-ferritin from natural ferritin. The rate of ferritin formation by the recombinant H-chain apoferritin was determined to be higher than that shown by natural tadpole ferritin, which consists of H, M and L-subunits. This phenomenon may be caused by the absence of M and L-subunits in the recombinant H-chain apoferritin.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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• pp.219-220
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• 2010

The purpose of this study is to evaluate chloride ion attack durability of concrete structure having experienced the high temperature fire. Mechanical properties and anti chloride ion diffusivity of concrete specimens were measured which have experienced of 2 hours heating at $200{^{\circ}C},\;400{^{\circ}C},\;600{^{\circ}C},\;800{^{\circ}C}$. The coupling FE model of thermal transfer and chloride ion diffusion was built to predict the life expectancy of RC structure using the property values by a series of experiment.

• Electrical & Electronic Materials
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• v.8 no.1
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• pp.64-70
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• 1995

We discussed the thermal analysis for a recording media with the variation of the laser pulse duration, the laser power and the temperature distribution in order to optimize the Te-based antireflection structure from the computer calculations. In the case that the radial heat diffusion is negligible, we can calculate the maximum temperature of the recording layer at the center of the spot by the Simple Model. The temperature profile of the recording layer is obtained from the Numerical Model by considering the total specific heat and the latent heat. As a result, the effect of the heat sinking acting as a thermal loss for the hole formation could be minimized by introducing the pulse with the hole formation duration(.tau.) below the thermal time constant(.tau.$_{D}$) of a dielectric layer. These requirments can be satisfied by using the dielectric thickness of the 2nd ART(Anti-Reflection Trilayer) condition or the dielectric materials with a low thermal diffusivity.y.

• Korean Journal of Materials Research
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• v.1 no.1
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• pp.29-36
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• 1991

Pressurized Water Reactor (PWR) pressure vessels are made of forged low alloy steel plates internally clad with an austenitic stainless steel by welding to improve anti-corrosion properties. They display a characteristic behavior of dissimilar metal weld interface during post weld heat treatment (PWHT) and service at high temperature and pressure. In this Study, Metallugical structure of weld interface of SA 508 Class 3 forged steel clad with 309L, Austenitic stainless steel after PWHT was investigated. To estimate the width of the carburized/decarburized bands quantitatively, a model for carbon diffusion was proposed and a theoretical equation was derived.

• Archives of Pharmacal Research
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• v.26 no.5
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• pp.389-393
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• 2003

The essential oils from Cedrus atlantica, Styrax tonkinensis, Juniperus communis, Lavandula angustifolia, Melaleuca alternifolia, Pelargonium graveolens, Pogestemon patchouli and Rosmarinus officinalis were analyzed by GC-MS. Antifungal activities of the oils were investigated by disk diffusion assay and the broth dilution method against Aspergillus niger and A. flavus. The effects of geraniol and the essential oil fraction from P. graveolens on the antifungal activity of amphotericin Band ketoconazole were examined using a checkerboard microtiter assay against both Aspergillus fungi. Most of the tested essential oils, with the exception of C. atlantica, J. communis, and P. patchouli, significantly inhibited growth of A. niger and to a lesser extent that of A. fIavus, with MICs (minimal inhibitory concentrations) in the range 0.78-12.5 mg/mL. The essential oil fraction of P. graveolens and its main components, geraniol and citronellol, exhibited additive effects with amphotericin B and with ketoconazole against both Aspergillus species, resulting in fractional inhibitory concentration (FIC) indices ranging from 0.52 to 1.00.

• Archives of Pharmacal Research
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• v.28 no.7
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• pp.765-769
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• 2005

The essential oil fraction of Ostericum koreanum was analyzed by GC-MS. Inhibiting activities of this oil and its main components were tested by the broth dilution assay and disk diffusion test against one antibiotic-susceptible and two resistant strains of Salmonella enteritidis and S. typhimurium, respectively. The GC-MS analysis revealed thirty-four compounds; the main components were $\alpha$-pinene (41.12%), $\rho$-cresol (17.99%) and 4-methylacetophenone (7.90%). The essential oil of O. koreanum and its main components were significantly effective against the tested antibiotic-susceptible strains as well as against the resistant strains of the two Salmonella species, with MICs (minimum inhibitory concentrations) ranging from 2 mg/mL to 16 mg/mL. The anti-Salmonella effects of the oils were dose-dependent on $M\"{u}ller-Hinton$ agar plates in this experiment. Additionally, checkerboard titer test results demonstrated significant combined effects of streptomycin and O. koreanum oil or cresol, one of the main components of this oil, against the two streptomycin resistant strains of S. typhimurium, with FICIs ranging from 0.12 to 0.37.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.1
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• pp.23-30
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• 2021

This study is an experiment to evaluate the anti-atopy efficacy of five kinds of natural plant essential oils; Artemisia annua L. (AA), Citrus junos Sieb. ex TANAKA (CJ), Chrysanthemum boreale Makino (CB), Pinus koraiensis (PK), and Pinus densiflora for. erecta (PD). Through Agar diffusion test, five species of native plant essential oils were treated in a total of four strains, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans. In order to invest the anti-inflammatory effect, five kinds of natural plant essential oils were treated in HaCaT cells-induced by TNF-α and IFN-γ (TI). AA, CJ, CB, PK and PD showed antibacterial effects on Candida albicans at a concentration of 10 mg/mL. We also found that the thymus and activation-regulated chemokine (TARC) expression was suppressed in 0.1 ㎍/mL of PK, 1 ㎍/mL of AA, CB, and PK. macrophage-derived chemokine (MDC) expression was suppressed in 1 ㎍/mL of AA and PK. IL-6 expression was suppressed in 0.1, 1 ㎍/mL of AA, PK in HaCaT cells. Hence it suggests that AA, CB, and PK have the anti-inflammatory effects, and it could contribute to atopic dermatitis relief by reducing the infiltration of immune cells to inflamed area.

• Fisheries and Aquatic Sciences
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• v.25 no.11
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• pp.579-586
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• 2022

Research on the potential biological activity of red alga Symphyocladia spp. has been limited to Symphyocladia latiuscula, which is widely used as a food ingredient in Korea. Here, we examined the biological activity of another species, Symphyocladia linearis, which is found in Korea and was reported as a new species in 2013. The aim of this study was to evaluate the antioxidant, anti-inflammatory, and antibacterial properties of a 70% ethanol extract of S. linearis. Antioxidant activity, which was evaluated using radical scavenging assays, revealed half maximal inhibitory concentration values for 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) of 34.57 and 11.70 ㎍/mL algal extract, respectively. Anti-inflammatory activity of the S. linearis ethanolic extract was evaluated using RAW 264.7 cells by measuring the inhibition of lipopolysaccharide-induced nitric oxide (NO) and prostaglandin E₂ (PGE₂) production. The potential cytotoxicity of NO and PGE₂ was first examined, confirming no toxicity at concentrations ranging from 10-100 ㎍/mL. NO production was inhibited 61.1% and 78.0% at 50 and 100 ㎍/mL S. linearis extract, respectively; and PGE₂ production was inhibited 69.1%, 83.2%, and 94.8% at 25, 50, and 100 ㎍/mL S. linearis extract, respectively. Thus, the S. linearis extract showed very strong efficacy against PGE₂ production. The cellular production of reactive oxygen species, measured using 2',7'-dichlorofluorescin diacetate fluorescence, was inhibited 48.8% by the addition of 100 ㎍/mL S. linearis extract. Antibacterial activity was evaluated using the disc diffusion method and minimum inhibitory concentration (MIC). S. linearis was effective only against gram-positive bacteria, exhibiting antibacterial activity against Staphylococcus aureus with a MIC of 256 ㎍/mL extract and against Bacillus cereus with a MIC of 1,024 ㎍/mL extract. Based on these results, we infer that a 70% ethanolic extract of S. linearis possesses strong anti-inflammatory properties, and therefore has the potential to be used in the prevention and treatment of inflammatory and immune diseases.

• Korean Journal of Poultry Science
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• v.20 no.2
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• pp.65-72
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• 1993

The experiment was conducted to estasblish the large scale production of anti-serum against chicken IgG and to profile the developmental changes of serum IgG levels during all the feeding period(from hatching to 7 weeks of age) in broiler chicks. Blood sample were taken from Hubbard chicken hi-daily or /and weekly during the experimental period. The pure IgG was isolated from ammonium sulfate treated chicken serum by ion exchange chromatography. The quantitative assay of serum IgG were carried by RID method. It was observed that IgG concentrations were showed the highest at hatching(4.25 $m\ell$/$m\ell$), after that dicreased rapidly, lowest at 2 weeks of age(0.81 $m\ell$/$m\ell$), and gradually increased to 7 weeks of age (2.48 $m\ell$/$m\ell$) There was no differences of IgG level between sex, but the IgG levels of male chicks dicreased more rapidly and increased earlier thereafter than those of females during the first two weeks of agg.