• Korean Journal of Weed Science
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• v.10 no.3
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• pp.221-226
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• 1990

This experiment was performed to identify and isolate a growth inhibiting compound from Aralia continentalis. In order to isolate the growth inhibiting compound from Aralia continentalis the bioassay test of lettuce seed germination and rice seedling growth were used. Through these bioassays the growth inhibiting compound which was spotted at $R_f$ 0.51 on Tlc was isolated. This compound inhibited the lettuce growth by 79% at the concentration of 1000ppm. When sprayed with $FeCl_3$ reagent, it developed a bule spot. It had UV-absorbance at 217 nm and 342 nm, and $OH^-$ of $3600cm^{-1}$, C=O of $1700cm^{-1}$, C=C of $1600cm^{-1}$, and C-O of $1200cm^{-1}$ on IR spectrum. Through HPLC analysis this compound was identified as a ferulic acid ($C_{10}H_{10}O_4$) having 25 min. retention time.

• Laser Solutions
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• v.15 no.3
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• pp.16-19
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• 2012

We have successfully formed brown colored patterns inside of a transparent borosilicate glass generally known as BK7, laying the focus of near infrared Ti: sapphire femtosecond laser beam in the bulk BK7 glass. It is important to keep the laser power well below the damage threshold of BK7 in forming the color center. According to the low laser power, there was no laser induced mechanical damage such as cracks or threads in the color formed area. From the absorbance spectrum and its gaussian fitting, we found the band gap of BK7, 4.21eV, and three absorption edges.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.723-727
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• 2002

Conformational changes of allivin, a major allergen protein in garlic, by gamma irradiation were observed. Allium solution (3.0 mg/mL in 0.01 M PBS, pH 7.4) and raw garlic were irradiated in a gamma irradiation facility to be absorbed with doses of 2.5, 5.0, 7.5 and 10.0 kGy. After irradiation, a half of irradiated allivin solution was filtered through 0.22 ${\mu}{\textrm}{m}$ filtration kit. UV spectrum and SDS-PAGE were used for observing the conformational changes of allivin by gamma irradiation. Turbidity of allivin solution was increased by optical observation, and the result was validated by the increase of absorbance at 660 m. Turbidity of irradiated and filtered allivin solution significantly (p<0.05) decreased, and the concentration of soluble protein in the solution decreased by increase of the dose. Aggregation among allivin molecules was observed by SDS-PAGE, but irradiated and filtered samples showed decrease of allivin with reducing aggregation trend. SDS-PAGE profiles of irradiated raw garlic were not different. Results indicate that gamma irradiation can decrease the allivin in solution state which may impact on allergenic reaction of garlic.

• Korean Journal of Plant Resources
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• v.26 no.3
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• pp.403-409
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• 2013

This study has assessed the anti-oxidative activities and cytotoxic effects of Lithospermum erythrorhizon ethanol extract and measured the effects of tyrosinase inhibition activities with a goal of estimating the usage of the medicinal plant as an ingredient of cosmetics. First, to perform a basic test on the extract, pH and UV-spectrum were measured. According to the measurement, the extract had control functions at pH 5.5, and maximum absorbance occurred at 530nm. In particular, DPPH (1-1-diphenyl-2-picryl-hydrazyl)-inhibiting activity (IC50) and polyphenol content were 149.81 ${\mu}g/mL$ and $51.28{\pm}2.52$ mg/mL respectively. In addition, as extract concentration increased, tyrosinase inhibition activities improved as well. In raw 264.7 cell-based MTT assay, cell survival rates were 98% at 1000 ppm and 153% at 100 ppm. Therefore, it's been confirmed that there is almost no cytotoxin. According to the test results above, it appears that the Lithospermum erythrorhizon ethanol extract would be effective in anti-oxidation and application as a cosmetic ingredient.

• Elastomers and Composites
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• v.52 no.4
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• pp.257-265
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• 2017

In this work, CR (Chloroprene Rubber) was emulsified by phase-inversion emulsification with nonionic surfactants (NP-1025, LE-1017, and OP-1019) and an anionic surfactant (SDBS; sodium dodecylbenzenesulfonate), and its stabilization was investigated through a study of its adsorption characteristics, zeta potential, and flow behavior. As the amount of the mixed surfactant increased, the droplet size decreased, resulting in the increase of viscosity. In particular, a CR emulsion with a lower absorbance in the UV spectrum exhibited the highest zeta potential. The results of this experiment showed that the CR emulsion prepared using (LE-1017) and SDBS was the most stable. In this study, calcium hydroxide and aluminum hydroxide were added to enhance the mechanical properties of the CR emulsion, and the relationship between tensile strength, tear strength and surface free energy were investigated. The tensile and tear strengths of the CR emulsion incresed as the amount of calcium hydroxide and aluminum hydroxide increased. The highest tensile and tear strengths and surface free energy were observed for additions of 1.0% calcium hydroxide and 0.80% aluminum hydroxide, respectively. It was concluded that the interfacial bonding strength was improved by the even dispersion of calcium hydroxide and aluminum hydroxide in the CR emulsion.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.5
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• pp.319-323
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• 2014

This study investigates the prediction of soil chemical properties (organic matter (OM), pH, Ca, Mg, K, Na, total acidity, cation exchange capacity (CEC)) on 688 Korean soil samples using the visible-near infrared reflectance (VIS-NIR) spectroscopy. Reflectance from the visible to near-infrared spectrum (350 to 2500 nm) was acquired using the ASD Field Spec Pro. A total of 688 soil samples from 168 soil profiles were collected from 2009 to 2011. The spectra were resampled to 10 nm spacing and converted to the 1st derivative of absorbance (log (1/R)), which was used for predicting soil chemical properties. Principal components analysis (PCA), partial least squares regression (PLSR) and regression rules model (Cubist) were applied to predict soil chemical properties. The regression rules model (Cubist) showed the best results among these, with lower error on the calibration data. For quantitatively determining OM, total acidity, CEC, a VIS-NIR spectroscopy could be used as a routine method if the estimation quality is more improved.

• Applied Biological Chemistry
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• v.31 no.4
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• pp.382-386
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• 1988

Extracellular protein produced by Bacillus sp. $T_2-3$ was characterized for its patterns of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and sephadex G-100 filtration, spectrum of maximum absorption, composition of amino acid and solubility to solvents. The extracellular protein was composed of two kinds of protein which was little difference in molecular weight about 49,000. Maximum absorbance of the extracellular protein was showed at 230nm and main amino acids of the extracellular protein were aspartic acid, glutamic acid and alanine. Solubility of the extracellular protein was 55.8% in $H_2O$ and 28.4% in 0.4% NaOH.

• Analytical Science and Technology
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• v.5 no.4
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• pp.455-464
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• 1992

Using FT-IR, we determined the depth of silylated layers produced from various gas-phase-silylation conditions was proposed by using Fourier Transform Infrared (FT-IR) spectroscopic analysis. The depth of silylated layer was determined from absorbance measurments of the significant peaks (Si-O-ph, Si-C, Si-H) of FT-IR spectra with background spectrum subtraction method. And the results were compared with thickness measurments of SEM. The results were well agree with SEM. It found to be well suited for determining silylation process window.

• Biomedical Science Letters
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• v.10 no.4
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• pp.403-406
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• 2004

Environmental endocrine disruptors (EDs) are toxic, hormone-like chemicals which can be found in our normal daily life. We have examined if EDs can inhibit the monocellular microorganisms such as lactic acid bacteria or if the growth of lactic acid bacteria could be resistant to the endocrine disruptors. We have used Lactobacillus paracasei subsp. paracasei (KCTC No. 3165) as an experimental strain and bisphenol A, benzophenone and phenylphenol for the comparison purpose. Experiments included the evaluation of turbidity, absorbance and actual cell counts. We found that No.3165 was somewhat resistant to EDs naturally, however, high concentration of EDs could inhibit the growth of No. 3165 completely. Different EDs showed different spectrum of inhibit. This study should contribute to the development of more resistant lactic acid bacteria to EDs and to the development of functional fermented beverage.

• Journal of the Korean Society of Costume
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• v.49
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• pp.73-84
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• 1999

The purpose of this study was to investigate dyeing properties of silk and wool fabric by Cassia tora extracts according to the conditions such as extraction(temperature time) dyeing(temperature time) condition kinds of mordants temperature of mordanting. The color fastness of laundering irradiation were examined. The results were as follows: The wavelength of maximum absorpthion by extracts appeared at 201, 277, 382nm in UV-Vis spectrum. Absorbance of extracts were increased with temperature and time. The extraction efficiency of Cassia tora was determined as $95^\circ{C}$ of extraction temperature 120 minutes of extraction time. Silk fabric had highest K/S value when dyeing for 90min at $40^\circ{C}$. Wool fabric had highest K/S value when dyeing for 60min at $80^\circ{C}$. Surface color of silk and wool fabric dyed with Cassia tora extracts was 3,9Y and 0.4Y but it was changed from 9.3YR to 7,4Y and from 9.4YR to 5Y by mordants. The fabrics of mordanted by metal ion dyed the depth of color. Laundering and irradiation fastness of mordanted fabrics were improved as compared with nonmordanted fabrics.