• KSBB Journal
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• v.23 no.6
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• pp.529-534
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• 2008

The reactive oxygen species generated by ultraviolet rays causes various types of cutaneous damage, such as lipid peroxidation and denaturation of the extra-cellular matrix. The accumulation of such damage contributes to skin aging, especially the formation of wrinkles. This study was carried out to develop functional cosmatic by using Oriental herb supercritical extracts (OHSE) for prevention of skin. Effects of OHSE on anti-oxidation, collagenase inhibition and collagen synthesis in normal human fibroblast were investigated. OHSE showed antioxidative activity as high as vitamin C, trolox and DL-penicillamine. Also OHSE showed promotive effect on collagen synthesis and inhibitory effect on collagenase activity. From this results, we conclude that OHSE may have the potential to be conveniently used as an additive in cosmetics for prevention and improvement of skin aging.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.5
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• pp.56-66
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• 2015

This study aims at developing a new seismic resistant method by using precast concrete wall panels for existing low-rise, reinforced concrete beam-column buildings such as school buildings. Three quasi-static hysteresis loading tests were performed on one unreinforced beam-column specimen and two reinforced specimens with U-type precast wall panels. Seismic resistant test of anchored and welded steel plate connections manifested an average of 2.8 times increase in the maximum loading (average 591.8 kN) in comparison to unreinforced beam-column specimen. The maximum drift ratios were also shown between 1.4% and 2.7%. An analytical study was performed while assuming the RC column on the right side and the vertical element of the reinforced PC panel to behave in completely composite manner and the RC column on the left side and PC panel to behave in completely non-composite manner when loading was exerted from upper right end of RC frame of specimen to its left side. It was found with the assumptions that the overall flexural behavior in principle agreed with the experimental result.

• Membrane Journal
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• v.25 no.5
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• pp.406-414
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• 2015

In this study, partially fluorinated cation exchange membranes were prepared by direct sulfonation of Poly(VDF-co-hexafluoropropylene) copolymers (PVDF-co-HFP) followed by a casting method for application in the Membrane capacitive deionization (MCDI). The structure of sulfonated PVDF-co-HFP (SPVDF) was confirmed by Fourier-transform infrared (FT-IR) and $^1H$ Nuclear magnetic resonance ($^1H$ NMR) analysis. For quantitative analysis of the chemical composition, the X-ray Photoelectron Spectroscopy (XPS) was used. The membrane properties such as water uptake, ion exchange capacity and electrical resistance were measured. It was suggested that the optimum direct sulfonation condition of PVDF-co-HFP ion exchange membranes was $60^{\circ}C$ and 7 hours for temperature and duration of sulfonation, respectively. The water uptake of the SPVDF ion exchange membrane was 21.5%. The ion exchange capacity and electrical resistance were 0.89 meq/g and $3.70{\Omega}{\cdot}cm^2$, respectively. It was investigated that if it is feasible to apply these membranes in MCDI at various cell potentials (0.9~1.5 V) and initial flow rates (10~40 mL/min). In the MCDI process, the maximum salt removal rate was 62.5% in repeated absorption-desorption cycles.

• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.704-709
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• 1998

Non-linear optical polymer based on poly (${\alpha}$-methylstyrene-co-maleic anhydride) (MSMA) substrate polymer was prepared by polymer reaction method and its thermal and electro-optic properties were examined. In the polymer reaction between MSMA substrate polymer and 2-[4-(4-nitrophenylazo)-N-ethylphenylamino]ethanol (DR1) chromophore, the degree of substitution of DR1 into MSMA was higher with the 4-dimethylaminopyridine (DMAP) as catalyst and 3-dicyclohexyl carbodiimide (DCC) as dehydrating agent (sample, MSMA-DC) than the one with just 4-dimethylaminopyridine as catalyst (sample, MSMA-D). The synthesized NLO polymer (MSMA-DC) exhibited electro-optic coefficient of 18 pm/V (632.8 nm) and glass transition temperature ($T_g$) of about $175^{\circ}C$.

• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.654-660
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• 1998

In preparing PSZT powder by hydrothermal synthesis, effects of reaction temperature, concentration of raw materials and mineralizer on crystallinity, particle size distribution, and dielectric constant were investigated. By varying the concentration of mineralizer and the ratio of Pb to Sr or Zr to Ti, crystalline PSZT powder, having the mean particle size of $0.3{\sim}15{\mu}m$, was prepared by hydrothermal synthesis in the temperature range of $120{\sim}200^{\circ}C$ for a 2h reaction. PSZT ceramics, having dielectric constant of 1000~3000, were prepared at $1150^{\circ}C$ for a 2h sintering reaction of the PSZT powders. Experimental results showed that the weight mean particle size of $0.5{\mu}m$ was obtained when the concentration of KOH in the solution was 10 wt % and the ratio of Pb to Sr was 0.95/0.05, that of Zr to Ti was 0.52/0.48. It also showed that the ceramics of dielectric constant of 2900 were prepared through sintering of this PSZT powder. Size of PSZT particles became smaller with its narrow distribution as the concentration of KOH increased up to 10 wt %. However, it came to be larger at this concentration and above. By adding small amount of Sr that would not affect that crystallinity of particles we can improve dielectric property of sintered materials. Addition of Zr may shift the major crystal phase of synthetic PSZT powder from tetragonal to rhombohedral phase.

• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.3
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• pp.203-206
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• 2003

New orchardgrass(Dactylis glomerata L.) variety named as “Jangbeol 101” was developed by the National Livestock Research Institute(NLRI) in 2002. To develope the new variety of orchardgras, 5 superior clones were selected and polycrossed for seed production. Synthetic seeds were examined on the agronomic growth characteristics and forage production at Suwon from 1995 to 1998, and regional trials were conducted in Suwon, Namwon and Pyungchang from 1999 to 2002 and Jeju from 2000 to 2002, respectively. “Jangbeol 101” showed semi-erect growth habit in fall and spring and medium type in length of flag leaf and upper internode. Plant height of “Jangbeol 101” was short compared to that of standard variety, “Ambassador” and heading date was delayed about 2 days as 14th May compared to Ambassador. Characters such as winter hardiness, regrowth, moisture tolerance, disease resistance of “Jangbeol 101” were stronger or better than those of Ambassador. “Jangbeol 101” showed 9% higher dry matter yield as 12,374 kg/ha compared to Amabassador. Nutritive value was appeared to be similar in both varieties.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.1
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• pp.15-18
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• 2016

'Onnuri 2ho' is a new orchardgrass (Dactylis glomerata L.) variety developed by the National Institute of Animal Science (NIAS) in 2014. Four superior clones were selected and polycrossed for seed production to develop this new variety of orchardgrass. The agronomic growth characteristics and forage productivity of 'Onnuri 2ho' were examined at Cheonan from 2010 to 2011. Regional adaptation trials were conducted in Cheonan, Hoengseong, Jinju and Jeju from 2012 to 2014. 'Onnuri 2ho' showed growth habit of medium type in fall and spring. It is long in length of flag leaf with medium upper internode. Plant height of 'Onnuri 2ho' was 4 cm more than that of control variety, 'Amba'. Its heading date was 4 days later than compared to control variety, 'Amba'. Characteristics such as waterlogging and disease resistance of 'Onnuri 2ho' were stronger or better than those of control variety, 'Amba', Especially, the dry matter yield of 'Onnuri 2ho' (15,814 kg/ha) was increased 34 % compared to that of control variety, Amba (11,778 kg/ha). Nutritive feed values of 'Onnuri 2ho' appeared to be similar to that of control variety 'Amba' except in Vitro dry matter digestibility (IVDMD).

• Journal of the Korean Applied Science and Technology
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• v.31 no.3
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• pp.500-508
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• 2014

For this research, synthesis acrylic resin by ethyl acrylate monomer(EAM) and prepared samples which set by difference amount of monoammonium phosphate solution in waterborne acrylic resin. Use these resins, analyzed mechanical properties and thermal stability by films and leather surface coated. The test of DSC experiment sample WAC-APS3 was $410^{\circ}C$ Tm values which means the highest content of monoammonium phosphate had highest thermal stability in acrylic resin. According to measure data for solvent resistance, all samples showed good property. As known in the results, increase of ammonium phosphate constant did not influence to big change of resin properties. In abrasion test WAC-APS3 was good abrasion properties(68.729 mg.loss). Test of tensile strength, as increase as monoammonium phosphate resin analyzed low properties $1.505kgf/mm^2$ to $1.275kgf/mm^2$. In elongation case, same as strength test result 425 % to 384 % by increase to monoammonium phosphate amount in acrylic resin.

• Journal of the Korean Society of Radiology
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• v.12 no.6
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• pp.777-783
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• 2018

The purpose of this study was to investigate the degree of tearing of the rubber when the spike of the syringe connector was connected to the bottle of the contrast medium composed of the rubber compound type and to investigate the presence of the synthetic rubber due to tearing and grinding and the size of the pulverized product when the pulverized matters rubber was detected. As a result, in the case of tearing degree, the front side of the first contact with the end of the syringe connector was torn more than the back side by about $3.14{\pm}0.04mm$, and the pulverized matters was detected on average 7 to 15 on the 10 contrast mediums. The average particle size was measured to be about $7.89{\pm}0.31{\mu}m$. In addition, it is necessary to develop a micro_filter type automatic injection system for blocking off the pulverized matters as well as additional experiments through various experiments and analysis methods, and it is considered that interest of related organizations will be needed in preparation of fatal accidents when pulverized matters is introduced.

• Applied Chemistry for Engineering
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• v.22 no.2
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• pp.167-172
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• 2011

In this work, the effect of surface treatment on mesoporous carbons (MCs) supports was investigated by analyzing surface functional groups. MCs were prepared by a conventional templating method using mesoporous silica (SBA-15) for using catalyst supports in direct methanol fuel cells (DMFCs). The MCs were treated with different phosphoric acid ($H_3PO_4$) concentrations i.e., 0, 1, 3, 4, and 5 M at 343 K for 6 h. And then Pt-Ru was deposited onto surface treated MCs (H-MCs) by chemical reduction method. The characteristics of Pt-Ru catalysts deposited onto H-MCs were determined by specific surface area and pore size analyzer, X-ray diffraction, X-ray photoelectron, transmission electron microscopy, and inductive coupled plasma-mass spectrometer. The electrochemical properties of Pt-Ru/H-MCs catalysts were also analyzed by cyclic voltammetry experiments. From the results of surface analysis, an oxygen functional group was introduced to the surface of carbon supports. From the results, the H4M-MCs carbon supports surface treated with 4 M $H_3PO_4$ led to uniform dispersion of Pt-Ru onto H4M-MCs, resulting in enhancing the electro-catalytic activity of Pt-Ru catalysts.