• Korean Journal of Medicinal Crop Science
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• v.21 no.4
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• pp.276-281
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• 2013

This study was conducted to compare the contents of ginsenoside according the water extract conditions of red ginseng. In method A, red ginseng extract was prepared at $75^{\circ}C$ for 18 hours by 1 time extraction, and method B, the preparation was done at $85^{\circ}C$ for 18 hours by 1 time extraction. In method C, the primary extract prepared at $75^{\circ}C$ for 9 hours was blended with the secondary extract prepared by re-extracting the red ginseng residue obtained after the primary extraction, at $85^{\circ}C$ for 9 hours. Method D was the same procedure as method C but the extraction temperature for the primary extraction was $85^{\circ}C$ and that for the secondary extraction was $95^{\circ}C$. The contents of total and $Rb_1$, $Rg_1$ and $Rg_3$ ginsenoside were highest in Method C. The content of prosapogenin (ginsenoside $Rg_2$, $Rg_3$, $Rb_1$ and $Rb_2$) was highest in Method B. There was no consistent tendency in Brix, pH, Hue value and absorbance among extraction methods.

• KSBB Journal
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• v.14 no.4
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• pp.465-469
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• 1999

Horseradish peroxidase(HRP) in organic solvent can be reactivated by evaporation. In order to measure the evaporation effect, the enzyme solutions were obtained by evaporation and dilution of organic solvent, respectively. Although two situations were thermodynamically identical, the activity from evaporation was higher than that from dilution. From the UV absorbance and the fluorescence intensity mesurements, it can be explained that reactivation of enzyme activity might be caused by reversible folding, and the enzyme obtained by evaporation was more refolded than that obtained by dilution.

• Polymer(Korea)
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• v.36 no.5
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• pp.662-667
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• 2012

Poly(ethylene terephthalate) (PET) base films with high light transmittance have been used for the substrate of various functional films in the flat panel display. The effects of the reflective index of coated films, the roughness of the film surface and the content of inorganic silica particles on the light transmittance were studied in this article. Light transmittance was increased by coating a water soluble resin with a low reflective index at an optimum thickness. The roughness of the film did not affect light transmittance when the Ra of the film surface was less than a quarter of the wavelength of incident light. Inorganic silica particles decreased light transmittance due to their absorbance and scattering of the incident light.

• Journal of Ginseng Research
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• v.9 no.2
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• pp.256-263
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• 1985

In order to investigate the inferior factor of red ginseng quality, the contents of various chemical components, physico-chemical properties and arrangement state of ginseng cells were observed. Contents of total reducing sugar, reducing sugar, crude protein, crude fibre and specific gravity of inside white part of red ginseng were less than those of normal part. But differences in content of crude saponin, HPLC pattern of ginsenosides and reducing ability for DP P H(1,1-dipheny 1-2-picrylhydrazyl) between normal and inside white part of red ginseng were not found. The optical density of 1 water extract of normal part of red ginseng did not differ from that of inside white 1 part of red ginseng, but the visible and UV absorbance of acid hydrolyzate of normal red ginseng showed higher than those of inside white part of red ginseng. The differences in the internal color and tissue of normal and inside white part of red ginseng were easily found with naked eye, and by the microscopic fractography, the orangement state of ginseng cell in the inside white part of red ginseng was less dense than that in normal red ginseng.

• YAKHAK HOEJI
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• v.47 no.3
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• pp.148-153
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• 2003

Skin moisture is an important factor in skin health. Measurement of moisture content can provide diagnostic information on the condition of skin. In this study, a portable near-infrared (NIR) system was newly integrated with a photo diode array detector that has no moving parts, and this system has been successfully applied for the evaluation of human skin moisture. Diffuse reflectance spectra were collected and transformed to absorbance using 1 nm step size over the wavelength range of 1100 nm to 2200 nm. Partial least squares regression (PLSR) was applied to develop a calibration model. For practical use for the evaluation of human skin moisture, the PLS model for human skin moisture was developed in vivo using the portable NIR system on the basis of the relative water content values of stratum corneum from the conventional capacitance method. The PLS model showed a good correlation. The calibration with the use of PLS model predicted human moisture with a standard error of prediction (SEP) of 3.5 at 1120∼1730 nm range. This study showed the possibility of skin moisture measurement using portable NIR system.

• Journal of the Korean Chemical Society
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• v.37 no.1
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• pp.112-118
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• 1993

A water-soluble chromogenic reagent, N,N'-oxalylbis(2-pyridyl-3'-sulphobenzoylhydrazone) has been synthesized. Spectrophotometric and first-and second-derivative spectrophotometric methods for the determination of copper with the reagent have been developed. Determination has been performed by measuring the absorbance and the first-and second-derivative values of the copper complexes in aqueous solutions (pH 1.89) at 379, 395, 363 and 421 nm, respectively. The method allows the determination of 0.12-1.20 ${\mu}g$ /ml of copper and has been applied to the analysis of aluminium alloy samples. The best results have been obtained from the measurements of the second-derivative values at 421 nm.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.12
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• pp.841-846
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• 2016

ZnO nanorods were grown on $SiO_2$ coated Si wafers and glass by the hydrothermal method. The structural and optical properties variation of ZnO nanorods as a function of growing time was studied. ~10 nm-thick ZnO thin films deposited on substrates by rf magnetron sputtering were employed as seed layers. Zinc nitrate hexahydrate (0.05 M) and hexamethylenetetramine (0.05 M) mixed in DI water were used as a reaction solution. ZnO nanorods were respectively grown for 30 min, 1 h, 2 h, 3 h, and 4 h by maintaining the reactor at $90^{\circ}C$. Crystallinity of ZnO nanorods was analyzed by X-ray diffraction, and the morphology of nanorods was observed by a field emission scanning electron microscope. Transmittance and absorbance were measured by a UV-Vis spectrophotometer, and energy band gap and urbach energy were obtained from the data. Photoluminescence measurements were carried out using Nd-Yag laser (266 nm).

• Membrane and Water Treatment
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• v.9 no.4
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• pp.205-210
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• 2018

In this study, we investigated coagulants such as polyaluminum chloride (PACl) and ferric chloride ($FeCl_3$) and the combination of a coagulant and powdered activated carbon (PAC) for the removal of dissolved organic matter (DOM) from fish processing effluent to reduce membrane fouling in microfiltration. The efficiency of each pretreatment was investigated through analyses of dissolved organic carbon (DOC) and ultraviolet absorbance at 254 nm ($UVA_{254}$). Membrane flux and silt density index (SDI) analyses were performed to evaluate membrane fouling; molecular weight distributions (MWD) and fluorescence excitation-emission matrix (FEEM) spectroscopy were analyzed to assess DOM characteristics. The results demonstrated that $FeCl_3$ exhibited higher DOC and $UVA_{254}$ removals than PACl for food processing effluent and a combination of $FeCl_3$ and PAC provided comparatively better results than simple $FeCl_3$ coagulation for the removal of DOM from fish processing effluent. This study suggests that membrane fouling could be minimized by proper pretreatment of food processing effluent using a combination of coagulation ($FeCl_3$) and adsorption (PAC). Analyses of MWD and FEEM revealed that the combination of $FeCl_3$ and PAC was more efficient at removing hydrophobic and small-sized DOM.

• YAKHAK HOEJI
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• v.35 no.3
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• pp.182-189
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• 1991

Systematic study on the extraction of ion pair by the use of picric acid (PCA) as an ion pair forming reagent to the aliphatic amines has not be done by spectrophotometric method. The extraction of ion pair by the use of PCA and 23 kinds of the aliphatic amines was examined. The procedure is as follows; Elving's buffer solution (pH 1.3~10, ionic strength 0.5) each amine solution, and PCA solution were taken into a test tube. The mixture was shaken mechanically with chlorform. The organic phase was filtered through a filter paper to remove water droplets. The absorbance was examined at $\lambda_{max}$ against a reagent blank. Primary and secondary whose carbon number were more than 7 or 6, respectively, are extractable as ion pairs with PCA, while tertiary amines and quaternary ammonium salts are also extractable without the correlation of carbon number. It was considered that the ion pair extraction of primary and secondary amines was affected by the number of carbon of amines, but its extraction of tertiary amines or quaternary ammonium salts was affected by kind of aliphatic amines rather than pKa values or carbon number of amines.

• Textile Coloration and Finishing
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• v.12 no.6
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• pp.389-395
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• 2000

A natural colorants was extracted from cherry by 10wt% aqueous acetic acid solution as an extractant. Silk and cotton fabrics were dyed with the cherry extract in the temperature range of $40-80^\circ{C}$ and for the time range of 30-60min. by pre- and post-mordanting with various mordants, their dyeability and fastness were investigated. The natural cherry extract prepared in this study has a maximum absorbance at 520nm. It was found that the optimum dyeing temperature and time were $40^\circ{C}$ and 50min, respectively. The pre-mordanting method was more effective than post-mordanting. All mordants except $SnCl_2\cdot{2H}_2O\;and\;FeSO_4\cdot{7H}_2O$ were effective for silk fabrics. However, the dyeability on cotton fabrics increased in the order of $CrK(SO_4)_2\cdot{12H_2O>(CH_3COO)_2Cu\cdot{H}_2O>CuSO_4\cdot{5H}_2O>AlK(SO_4)_2\cdot{12H}_2O>FeSO_4\cdot{7H}_2O>SnCl_2\cdot{2H}_2O$ among the mordants used in this study Fastness(light, water, washing, perpspiration fastness) on the silk and cotton fabrics increased with using mordants. The post-mordanting using mordant$(CH_3COO)_2Cu\cdot{H}_2O$ among the various mordants in this study gave the best fastness.