• Korean Journal of Environmental Agriculture
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• v.33 no.3
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• pp.205-212
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• 2014

BACKGROUND: This study focused on the contents of flavonoid compounds in vegetables. Generally vegetables have contributed to a healthy diet, arisen from contains a large amount of fiber and functional ingredients. And flavonoid compounds are one of major functional components in the vegetables. currently research of flavonoid contents does not enough, specially in the part of homegrown vegetable. METHODS AND RESULTS: Vegetable samples were purchased in domestic market. Sample extraction by methanol, distilled water, and formic acid based solvent. Also same solvent used for mobile phase in UPLC. Eleven types of flavonoid compounds were analyzed with same kind of external standard and one kind of internal standard (galangin) for quantification. Standard calibration curve presented linearity with the correlation coefficient $R^2$ > 0.98, analysed from 1 to 50 ppm concentration. The quantitative value and multivariate analysis results were derived from the Excel and SIMCA-P11. Overall, onion has largest amount(916.5 mg/100 g) of flavonoid and also other vegetables have has significant amount[Mugwort: 138.8, Galic stem:123.6 mg/100 g etc.] of flavonoid compounds. Edible portion of vegetables per share for simulating by SIMCA-P11, root vegetables has had difference with other vegetables according to distributions and amounts of flavonoid compounds. CONCLUSION: Optionally, the results from this experiment can use to select the material for flavonoid researches. And based on these results, if this experiment will be continuously complemented, and performed, could used in various fields.

• Korean Journal of Environmental Biology
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• v.25 no.3
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• pp.191-196
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• 2007

Indoor air differs from outdoor atmosphere since it contains chemical and physical contaminants from building materials. This study deals with the biological effects of volatile organic compounds (VOCs) released from synthetic fiber carpet materials. One group of Tradescantia inflorescence was exposed to VOCs from the carpet sample in the environmental test chamber, while the other inflorescence group was exposed to a TO-14 standard gas mixture (1 ppm) for comparison. After the exposure, VOCs from the carpet were analysed by the desorber/GC/MS method, and micronuclei in the pollen mother cells of Tradescantia were scored under a microscope $({\times}400)$ to evaluate the genotocixicity induced by the exposure to VOCs. The chemical analysis confirmed that a total of 12 VOCs were released from the carpet materials, among which stylene $(71.9{\mu}g\;m^{-3})$ and toluene $(49.6{\mu}g\;m^{-3})$ were in the highest concentration. Twenty four hours of exposure to VOCs from the carpet in the environmental test chamber resulted in a micronucleus frequency as high as $7.73{\pm}0.75MCN$ per 100 tetrads, which was similar to that induced after exposure to the TO-14 standard gas mixture (1 ppm) for 4 hours. Meanwhile, two hours of exposure to the standard gas mixture did not cause a significant increase in the genotoxicity compared to the spontaneous micronucleus frequency. This result indicates that exposure for a long time to the air contaminated with VOCs from the carpet materials causes a genotoxic effect. The biological-chemical combination analyses in the study proved to be an effective tool for monitoring the indoor air contaminants.

• Journal of Korean Society of Steel Construction
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• v.22 no.3
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• pp.281-291
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• 2010

In this study, a five-story steel frame was designed in accordance with KBC2005 to evaluate the effects of the beam-column connection on the structural behavior. The connections were designed as fully rigid and semi-rigid. The fiber model was used to describe the moment-curvature relationship of the steel beam and the column, the power model for the moment-rotation angle of the semi-rigid connection and the three-parameter model for the hysteretic behavior of the steel beam, column, and connection. The structure was idealized as separate 2-D frames and as connected 2-D frames. The peak ground accelerations of four earthquake records were modified in a time-history analysis for the levels of the mean return period and for the maximum base-shear force in a pushover analysis. The top story displacement, base-shear force, story drift, demanded ductility ratio for the semi-rigid connection, maximum bending moment of the column, beam, and connection, and distribution of the plastic hinge were examined in the time-history analysis. The frame with the semi-rigid connection yielded a lower base-shear force, less magnitude, and increasing ratio in the bending moment of the column, beam, and connection than the frame with a fully rigid connection. The TSD connection was deemed to have secured the economy and safety of the sample structure that was subjected to seismic excitation for the Korean design level.

• Applied Chemistry for Engineering
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• v.23 no.3
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• pp.313-319
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• 2012

In this work, the electroplating of copper was introduced on PAN-based carbon fibers for the enhancement of mechanical interfacial strength of carbon fibers-reinforced composites. The surface properties of carbon fibers were determined by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and contact angle measurements. Its mechanical interfacial properties of the composites were studied by interlaminar shear strength (ILSS) and critical stress intensity factor ($K_{IC}$). From the results, it was found that the mechanical interfacial properties of Cu-plated carbon fibers-reinforced composites (Cu-CFRPs) enhanced with increasing the Cu plating time, Cu content and COOH group up to Cu-CFRP-30. However, the mechanical interfacial properties of the Cu-CFRPs decreased dramatically in the excessively Cu-plated CFRPs sample. In conclusion, the presence of Cu particles on carbon fiber surfaces can be a key factor to determine the mechanical interfacial properties of the Cu-CFRPs, but the excessive Cu content can lead the failure due to the interfacial separation between fibers and matrices in this system.

• Science of Emotion and Sensibility
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• v.14 no.1
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• pp.165-174
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• 2011

Recent years have witnessed that IT-convergence technology has become the most important issue in the global market. Along with this trend, demand for PSS(i.e., Product-Service Systems) design has been rapidly increased in the smart clothing market. A case of the PSS design research, this study aimed to identify optimum conditions for weaving of POF-based flexible textile display(abbreviated as "PFTD") for mountaineer wear with safe-guard function regarding luminescent properties. Based on the findings regarding the optimum weaving condition of PFTD, several designs of mountaineer wear were suggested in this study. A total of 15 PFTD samples were prepared under various weaving conditions of weave structures and density of POF, and the luminance values of each sample were measured. As the results, the types of PFTD with structures and density of 'satin 3:1', 'satin 2:1', 'twill 3:1' and 'twill 2:1' indicated relatively higher luminescence. And based on the results and recent sports fashion trends, two suited mountaineering wears applying PFTD were illustrated in this study.

• Korean journal of food and cookery science
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• v.23 no.5
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• pp.720-730
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• 2007

This study was investigated (replaced) the sensory and physicochemical properties of Jeungpyun substituted with 30% or 60% of brown rice and barley flours, respectively. The quality changes of the functional Jeougpyun during the storage periods were analyzed by a texturometer. We found that batter pH was decreased as fermentation progressed, but showed a higher pH resulted after steaming. The brown rice replaced Jeungpyun had higher specific gravity and lower viscosity; however, the barley-replaced Jeungpyun had lower specific gravity and higher viscosity compared to those of the control(0% replace with brown rice or barley flour). The barley-replaced samples showed significantly larger volume indexes than that of the control. The L-value of the for lightness decreased significantly within the replaced samples(p<0.001). All samples had negative a-values, with slight peen colors rather than red. The barley-replaced samples were darker than those of the brown rice sample groups, with less green and yellow color. The brown rice-replaced samples had larger values for adhesiveness, overall, and moistness, and the barley-replaced samples showed intensities greater in cell size, springiness, hardness, and flavor by sensory evaluation. The 30% flour-replaced samples of the comparisons had higher values for overall desirability(p<0.001). The replaced samples showed slow increases in hardness when measured by a texturometer, indicating that, the retrogradation rates decreased as the storage periods increased. The control stored for 72 hr had a hardness value that was 8.0 times harder than that of the control stored for one hour. The 30 and 60% brown rice-replaced samples stored for 72 hr were 5.8 times and 4.7 times harder of their replacement level, respectively, and the 30 and 60% barley-replaced samples stored for 72 hr were 5.7 times and 4.2 times harder of their replacement level, respectively. The adhesiveness and cohesiveness of all samples tended to decrease as the storage period increased. The barley-replaced samples showed significantly the lower adhesiveness and cohesiveness during the storage periods. The springiness of all samples decreased slowly during the storage periods. In conclusion, Jeungpyun that was substituted with brown rice and barley flours demonstrated improved functionality and higher dietary fiber replaced effect. Furthermore, the storage period of was extended as the retrogradation rate was delayed as a result of the dietary fibers.

• Food Science and Preservation
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• v.13 no.6
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• pp.669-674
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• 2006

In order to develop a model on the quality and nutrition label of Korean fruit plum, we first examined the quality and nutritional characteristics of Korean Plum, ChooHee. The contents of moisture, crude protein, crude fat, crude fiber, crude ash and N-free extinct were 92% 0.74% 0.64% 1.65%, 0.32% 4.29% respectively. Thus the total calorie of the sample was 32 kcal/100 g. The content of sugar, acidity and Vitamin C were $33{\pm}0.85 Bx^{\circ}$, $1.08{\pm}0.12%$ and $7.037{\pm}0.317mg%$ respectively. The principle minerals were S, K, Ca, Na, and Mg. Major free sugars were fructose, glucose and sucrose and major organic acid were succinic acid, malic acid and citric acid. The difference of contents of total phenols between peel and flesh pare were considerable. The total phenolic contents of whole fruit were $75.55{\pm}0.73mg%$. On the above results, the quality and nutrition label of Korean plum were developed in the first time. We expect that this study on labeling could play an important role to the quality control and marketing of Korean agricultural products.

• Korean journal of food and cookery science
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• v.22 no.6 s.96
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• pp.869-874
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• 2006

This study investigated the effect of bamboo leaf powder, added at content of 0%, 3%, 6%, 9% and 12%, on the quality and sensory characteristics of rice cake imprinted with flower pattern (Ed-there is no respecitive comparison here) The chemical composition as a whole was 3.07${\pm}$0.12% of moisture, 5.87${\pm}$0.02% of crude protein, 2.52${\pm}$0.05% of crude fat, 23.70${\pm}$0.07% of crude fiber and 7.73${\pm}$0.02% of crude ash. With increasing amount of added bamboo leaf powder, the hardness and chewiness of the cake were significantly increased(p<0.05), while the cohesiveness, springiness and adhesiveness were decreased. In chromaticity, the L-value, the indicator of brightness, was significantly decreased with increasing bamboo leaf powder content. The a-value, the indicator of redness, was significantly lower than the chlorophyll color (p<0.05). The b-value, the indicator of yellowness, was increased indirect proportion to the content. In sensory test, the sensory characteristics such as color, flavor, taste and chewiness were all stronger with increasing powder content, whereas the softness and dampness were weaker. The greatest overall satisfaction was achieved by the sample group of cake with 6% preference added powder.

• The Korean Journal of Food And Nutrition
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• v.16 no.4
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• pp.340-346
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• 2003

The diet food used in this test was composed of the total 16 kinds, such as refined water, herb extract, pomegranate extract, polydextrose and isomalto-oligosaccharide etc. Edible fiber as a major component in dietary food was contained to 2.60%(w/w) level. But the calorie was 104.57kca1/100g, contrast of control domestic saengshick product was 368.06kca1. As a result, calorie of dietary food sample was very low level. Vitamin and mineral as a minor component were determined 5, 6 kinds, respectively. On the other hand, dietary effect of body weight loss was determined about 14%(w/w) at animal test result used for rats during 4 weeks. The reason of dietary effect could confirmed from change of plasma neutral lipids, total cholesterol and HDL-cholesterol concentration. Increasing ratio of these in the general diet and dietary diet feeding groups during 4 weeks were 10.55, 6.90, 9.82% and 6.11, 3.85, 6.11%, respectively. from these results, decrease reason of body weight could confirmed the relative relationship with plasma lipids and cholesterol concentration. But plasma plasma glucose and insulin concentration have not positive relativity.

• Advanced Composite Materials
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• v.17 no.1
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• pp.25-40
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• 2008

The research and development in soundproof materials for preventing noise have attracted great attention due to their social impact. Noise insulation materials are especially important in the field of soundproofing. Since the insulation ability of most materials follows a mass rule, the heavy weight materials like concrete, lead and steel board are mainly used in the current noise insulation materials. To overcome some weak points in these materials, fiber reinforced composite materials with lightweight and other high performance characteristics are now being used. In this paper, innovative insulation sheet materials with carbon and/or glass fabrics and nano-silica hybrid PU resin are developed. The parameters related to sound performance, such as materials and fabric texture in base fabric, hybrid method of resin, size of silica particle and so on, are investigated. At the same time, the wave analysis code (PZFlex) is used to simulate some of experimental results. As a result, it is found that both bundle density and fabric texture in the base fabrics play an important role on the soundproof performance. Compared with the effect of base fabrics, the transmission loss in sheet materials increased more than 10 dB even though the thickness of the sample was only about 0.7 mm. The results show different values of transmission loss factor when the diameters of silica particles in coating materials changed. It is understood that the effect of the soundproof performance is different due to the change of hybrid method and the size of silica particles. Fillers occupying appropriate positions and with optimum size may achieve a better effect in soundproof performance. The effect of the particle content on the soundproof performance is confirmed, but there is a limit for the addition of the fillers. The optimization of silica content for the improvement of the sound insulation effect is important. It is observed that nano-particles will have better effect on the high soundproof performance. The sound insulation effect has been understood through a comparison between the experimental and analytical results. It is confirmed that the time-domain finite wave analysis (PZFlex) is effective for the prediction and design of soundproof performance materials. Both experimental and analytical results indicate that the developed materials have advantages in lightweight, flexibility, other mechanical properties and excellent soundproof performance.