• Korean Journal of Pharmacognosy
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• v.36 no.3 s.142
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• pp.235-239
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• 2005

Changes in chemical composition of the ethanolic extract of roasted Asparagi Tuber were investigated by HPLC. One dramatically increased peak $(t_R\;14.85 min)$ was isolated by silica gel column chromatograph and identified as 5-hydroxymethyl furfural (HMF) by comparing its $1^H-NMR$ data with that of a commercial standard. HMF content reached its maximum level at $190^{\circ}C$ for 60 minutes. Under these conditions, HMF contents in the roasted Asparagi Tuber was increased about thirteen times (9.26mg/g) over the not-roasted control (0.71 mg/g). No significant differences were found in macrophage-activating, prolyl endopeptidase-inhibiting, antioxidative (DPPH), anti-coagulating (activated partial thromboplastin times), and ACE-inhibiting activities between roasted and not-roasted Asparagi Tuber.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.271-278
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• 2006

We used polymers of alternating cationic and anionic nature to build up shells on fiber surfaces, strengthen the worn-out fibers and improve paper properties made from such fibers. OCC and ONP pulps were either dipped or salted out in the cationic polyallylamine, polyacrylamide and starch solutions. After centrifugal drying, these were followed by treatments in anionic polyacrylic acid, poly-acrylamide, and starch solutions, respectively. The shell-enhanced fibers were formed into handsheets and their physical properties evaluated. The results show that building multiple shells on worn-out fiber surfaces can strengthen the fibers and paper. The simpler and more practical impregnation-centrifuging treatment provided the desired effects, whereas salting out the polymers produced somewhat superior fibers. The latter process, were impractical, however. The first pair of polymeric shells imparted marked strength improvement, whereas later layers had diminishing efficacies. Overall, the methods can improve fiber quality, attaining paper strength requirements without resorting to expensive measures. Alternate cationic polymer and filler powders were also deposited on fiber surface based on the micriparticle system in an anticipation of stiffness gains. Platy minerals, such as montmorillonite, bentonite, sericite, clay and talc were added following cationic PAM. After dewatering of polymer-pigment shelled fiber of one to 3 pairs of layers, handsheets either calendered or uncalendered were evaluated. The results indicate that regardless of calendaring, stiffness of the handsheets did not improve appreciably while certain other strength properties showed gains. We also attempted the novel starch gel filler addition method wherein tapioca starch and filers (PCC, sericite or clay) were mixed at high solids content of 50% and cooked until gelatinized. The filled handsheets were dried under various conditions and then tested for their properties. Improvements in strengths of modified filled paper were observed.

• Journal of Radiation Industry
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• v.6 no.2
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• pp.153-158
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• 2012

In this research, poly(acrylic acid) (PAAc) hydrogels containing zinc oxide particle were prepared by gamma-ray irradiation. PAAc powder was completely dissolved in distilled water at room temperature. Water-insoluble zinc oxide powder were added into the PAAc solution and stirred until totally dissolved. Finally, the mixture was irradiated by gamma-ray irradiation to make crosslinking. The effects of various parameters such as zinc ions' concentration, irradiation doses were varied and investigated in detail. PAAc hydrogels containing zinc oxide particle were characterized by gel content and swelling ratio. Moreover, the antibacterial properties of this material were evaluated by paper diffusion test against the Gram positive and Gram negative bacteria.

• Journal of Radiation Industry
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• v.9 no.1
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• pp.9-13
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• 2015

Epoxy resin is widely used as aerospace, automobile, construction and electronics due to their good mechanical and electrical properties and environmental advantages. However, the inherent flammability of epoxy resin has limited its application in some field where good flame retardancy is required. Nano clay can enhance the properties of polymers such as flames retardancy and thermal stability. In this study, we have investigated the nanoclay filled epoxy composite, which has good flame retardancy while maintaining high mechanical properties. The cured epoxy resins were obtained using an electron beam curing process. The nano clays were dispersed in epoxy acrylate solution and mechanically stirred. The prepared mixtures were irradiated using an electron beam accelerator. The composites were characterized by gel content and thermal/mechanical properties. Moreover, the flammability of the composite was evaluated by limited oxygen index (LOI). The flame retardancy of nano clay filled epoxy composite was evidently improved.

• Journal of Radiation Industry
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• v.9 no.4
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• pp.199-207
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• 2015

Typical radiation cross-linked hydrogels has the characteristic that high water content, but low emission efficiency of active ingredients. Therefore, the hydrogel was prepared by the addition to collagen, which is closely related to the formation of skin wrinkles in biocompatibility and highly water-soluble carboxymethyl cellulose sodium salt (CMC) in order to preparation of hydrogels has excellent emission efficiency of active ingredients. Hydrogels were prepared by dissolving CMC and collagen each of 0.5%, 10% concentration in deionized water. Then, prepared hydrogels are performed by gamma-radiation at 1, 3, 5 kGy irradiation dose. The results showed that the gel fraction of after irradiated 3 kGy hydrogel was higher than before irradiated gelation as long as the 55.3%. The swelling rate of irradiated 3 kGy hydrogel was lower than the non-irradiated sample. The compressive strength of 3 kGy irradiated hydrogel was the highest. The visco-elastic did not show any significant differences, even after irradiation. The CMC hydrogel in this study suggested a potential use as a material for the mask pack for improved emission efficiency of the active ingredient and anti-wrinkles.

• Journal of Adhesion and Interface
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• v.1 no.1
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• pp.15-22
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• 2000

To prepare acrylic type pressure-sensitive adhesive, quarter polymers were synthesized from butylacrylate (BA), 2-ethylhexylacrylate (2-EHA), methyl methacrylate (MMA), 2-hydroxyethylmethacrylate (2-HEMA). The quarter polymer was identified by FT-IR. Molecular weight was measured by Gel Pearmeation Chromatograhy. Also, viscosity, solid content and peel strength were investigated. The peel strength was $160g_f/25mm$ when the volume ratio of feed monomer to solvent was 1.3:1 and the ratio was relevant to commercial usage. The pot life of adhesive was 30 s at the 50 m/min of heat treatment rate, and it indicated that the minimum drying time was 30 s. Not only weathering resistance keep up peel strength $160{\sim}180g_f/25mm$ after 1000 h, but also no residual remains.

• Journal of Convergence for Information Technology
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• v.9 no.6
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• pp.233-241
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• 2019

This study was conducted on women in their 20s and 30s living in the Seoul metropolitan area by using questionnaires on the recognition and purchase behavior of mask packs. According to this study, although there is high interest in skin beauty, the recognition of characteristics and distinctions according to mask pack type was found to be insufficient. After using mask packs, 51.5% of those surveyed were satisfied with their efficacy and effectiveness. When using the mask pack, the Sheet type mask pack was discontented with usability, size, Close Adhesion and skin irritation, Hydrogel type is material, sleeping type is content and absorbent, cellulose type pack was found to have the same discomfort with the material as the hydro gel type. Through the results of this study, the possibility of utilization as basic data for mask pack market marketing was confirmed.

• Journal of the Korean Ceramic Society
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• v.56 no.1
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• pp.98-103
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• 2019

Optical filters to control light wavelength of displays or cameras are fabricated by multi-layer stacking process of low and high index thin films. The process of multi-layer stacking of thin films has received much attention as an optimal process for effective manufacturing in the optical filter industry. However, multi-layer processing has disadvantages of complicated thin film process, and difficulty of precise control of film morphology and material selection, all of which are critical for transmittance and coloring effect on filters. In this study, the composite $TiO_2$, which can be used to control of UV absorption, coated on nano hollow silica sol, was synthesized as a coating material for optical filters. Furthermore, systematic analysis of the process parameters during the chemical reaction, and of the structural properties of the coating solutions was performed using SEM, TEM, XRD and photo spectrometry. From the structural analysis, we found that the 85 nm nano hollow silica with 2.5 nm $TiO_2$ shell formation was successfully synthesized at proper pH control and titanium butoxide content. Photo luminescence characteristics, excited by UV irradiation, show that stable absorption of 350 nm-light, correlated with a 3.54 eV band gap, existed for the $TiO_2$ shell-nano hollow silica reacted with 8.8 mole titanium butoxide solution. Transmittance observed on substrate of the $TiO_2$ shell-nano hollow silica showed effective absorption of 200-300 nm UV light without deterioration of visible light transparency.

• The Plant Pathology Journal
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• v.35 no.4
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• pp.313-320
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• 2019

Rye was used here to dissect molecular mechanisms of resistance to Fusarium head blight (FHB) and to go deeper with our understanding of that process in cereals. F. culmorum-damaged kernels of two lines different in their potential of resistance to FHB were analyzed using two-dimensional gel electrophoresis and mass spectrometry to identify resistance markers. The proteome profiling was accompanied by measurements of ${\alpha}-$ and ${\beta}-amylase$ activities and mycotoxin content. The proteomic studies indicated a total of 18 spots with clear differences in protein abundance between the more resistant and more susceptible rye lines after infection. Eight proteins were involved in carbohydrate metabolism of which six proteins showed a significantly higher abundance in the resistant line. The other proteins recognized here were involved in stress response and redox homeostasis. Three remaining proteins were associated with protease inhibition/resistance and lignin biosynthesis, revealing higher accumulation levels in the susceptible rye line. After inoculation, the activities of ${\alpha}-$ and ${\beta}-amylases$, higher in the susceptible line, were probably responsible for a higher level of starch decomposition after infection and a higher susceptibility to FHB. The presented results could be a good reference for further research to improve crop resistance to FHB.

• Korean Journal of Medicinal Crop Science
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• v.27 no.2
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• pp.108-114
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• 2019

Background: Rutin is decomposed by rutin-degrading enzymes (RDE) during the processing of buckwheat groats, resulting in a decrease in rutin content and a further increase in the bitterness of processed products. Thus, the present study aimed to examine RDE activity in groats and various tissues of domestic buckwheat varieties and to develop a method to reduce the loss of rutin during the groat processing. Methods and Results: RDE activity and isozymes patterns were determined in Tartary and common buckwheat. RDE activity, measured by quercetin production rate, was 273 and $70{\mu}g/g$ fresh weight/min in mature Tartary and common buckwheat groats, respectively. A total of six RDE isozymes were detected in mature groats of Tartary buckwheat on a non-denaturing gel. In Tartary buckwheat groats, RDE activity decreased by approximately 81 or 71% with roasting or steaming for 5 min respectively. As the roasting or steaming time increased to 30 min, RDE activity decreased by over 95%. These results indicated that RDE was inactivated in groats by roasting or steaming. When untreated Tartary buckwheat groats were kneaded with powder, RDE was activated and the quercetin production rate increased by 62%. However, when roasted groats were kneaded with powder, the quercetin production rate decreased by 93%, mainly due mainly to inactivation of RDE, as indicated by a decrease in band intensities of the six isozymes. Conclusions: These results suggested that the loss of rutin, due to RDE activity during processing, may be reduced by 71 to 100% by roasting or steaming groats for 5 to 30 min, due in large part to the inactivation of RDE isozymes.