• Elastomers and Composites
• /
• v.47 no.1
• /
• pp.2-8
• /
• 2012

In this study, in order to develop renewable bio-based nanocomposites, multi-functional nanocomposites from soybean resins (AESO, MAESO) and nanoclay were prepared. Photoelectrodes for environmental friendly dye-sensitized solar cell using soybean resin were also prepared. Organo-modified nanoclay was directly dispersed in functionalized soybean resins after mixing with styrene as a comonomer and radical initiator was used to copolymerize the nanocomposites. The observed morphology was a mixture of intercalated/exfoliated structure and the physical properties were improved by adding nanoclay. A nanocomposite using MAESO, which added COOH functional group to the soybean resin, showed better dispersibility than AESO composites. Ultrasonic treatment of the nanocomposites also improved the physical properties. Nanoporous $TiO_2$ photoelectrode was also prepared using soybean resins as a binder, after acid-treatment of $TiO_2$ surface using nitric acid. Dye-sensitized solar cells were prepared after adsorbing dye molecules on it. The $TiO_2$ photoelectrode prepared using soybean binder had high current density because of increased surface area by improved dispersibility. The photoelectrochemical properties and conversion efficiency of the solar cell were significantly improved using the soybean binder.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.4
• /
• pp.596-601
• /
• 2020

Silicon carbide is considered a potentially useful material for high-temperature electronic devices because of its large band gap energy and p-type or n-type conduction that can be controlled by impurity doping. Accordingly, the thermoelectric properties of -SiC powder prepared by refined diatomite were investigated for high value-added applications of natural diatomite. -SiC powder was synthesized by a carbothermal reduction of the SiO₂ in refined diatomite using carbon black. An acid-treatment process was then performed to eliminate the remaining impurities (Fe, Ca, etc.). n-Type semiconductors were fabricated by sintering the pressed powder at 2000℃ for 1~5h in an N2 atmosphere. The electrical conductivity increased with increasing sintering time, which might be due to an increase in carrier concentration and improvement in grain-to-grain connectivity. The carrier compensation effect caused by the remaining acceptor impurities (Al, etc.) in the obtained -SiC had a deleterious influence on the electrical conductivity. The absolute value of the Seebeck coefficient increased with increasing sintering time, which might be due to a decrease in the stacking fault density accompanied by grain or crystallite growth. On the other hand, the power factor, which reflects the thermoelectric conversion efficiency of the present work, was slightly lower than that of the porous SiC semiconductors fabricated by conventional high-purity -SiC powder, it can be stated that the thermoelectric properties could be improved further by precise control of an acid-treatment process.

• Journal of Food Hygiene and Safety
• /
• v.22 no.1
• /
• pp.63-75
• /
• 2007

A survey on sanitary management at 98 food service institutions located in Jeollabuk-Do were conducted. Food service institutions included 13 hospitals, 38 schools, 40 enterprises, and 7 others. The sterilization in boiling water was used for disinfection of tableware, spoon and chopsticks, and dish towel. Cooking kit, refrigerator, chopping board, and knife were sterilized with disinfectant. Frequency of sanitary training program on employees was 56.1% for 1 time/month, 12.2% for 2-3 times/month, and 11.3% for 1 time/week. Preparing ratio of defrosting, warehouse and rest room, and washing and sterilization diary were 73.8, 60.5, and 54.5%, respectively. However, checking ratio of environments (9.5%), personal sanitation (10.8%), and sanitary training program diary(8.4%) were low. Major obstacle factors on the introduction of Hazard analysis critical control point (HACCP) system into food service institutions were lack of equipment and facilities (54.1%) and lack of understanding and data on HACCP system (17.3%). Therefore, in order to reduce the outbreak of food-borne diseases increasing frequency, we estimated that the introduction of sanitary management system and the conversion of dietician' perception on sanitary managements in food service institutions were needed.

• Journal of Ginseng Research
• /
• v.33 no.4
• /
• pp.349-354
• /
• 2009

This study was conducted to develop a new method for enhancing ginsenoside $Rg_3$, which is abundant in black ginseng. The cognition-enhancing effect of black ginseng extract was investigated via the assay of acetylcholinesterase (AChE) activity. Black ginseng I was prepared through the traditional method (by steaming and drying nine times repetitions). Black ginseng II, on the other hand, was prepared by steaming the ginseng three times at $120^{\circ}C$ for 30 min after soaking it in grape juice for 24 h. The ginsenosides of white, red, and black ginseng I, and II were investigated using the HPLC method, respectively. In black ginseng II, the ginsenoside $Rg_3$ contents, which cannot be found in white ginseng, amounted to 10.91 mg/g, approximately 18 times more than that in red ginseng. In the in-vivo study, black ginseng extract (200 mg/kg, p.o.) inhibited the AChE activity after 24 h by a single administration in the brain. Thus, the new manufacturing method for black ginseng was found to more effective in the conversion of ginsenoside $Rg_3$ compared to the traditional method. Black ginseng may also have the effect of preventing the cognitive impairment induced by cholinergic dysfunction.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.44 no.2
• /
• pp.111-116
• /
• 2018

In cosmetics market, anti-pollution products recently come up with new solution for skin health. Environmental oxidation mechanisms are realized as bio-marker of atmospheric pollution upon skin by environmental pollutant such as ozone, UV rays, particulate matter (PM) as well as cigarette smoke. The exposure of cigarette smoke directly or indirectly causes the oxidation of the stratum corneum skin lipids, resulting in the conversion of squalene to squalene monohydroperoxide and/or generation of malondialdehyde (MDA) as a product of lipid peroxidation. The aim of this study is to see whether new cosmetics product containing red beet has anti-oxidation effect on skin exposed by cigarette smoke. So as to determine oxidative damage to human skin at biochemical level, each unit area of volar forearms was exposed to cigarette smoke through device (3.3 cm, diameter) for fifteen minutes, then measured MDA using standardized TBARS assay kit. Compared to negative control (untreated and unexposed area), the level of MDA was significantly increased at positive control (untreated and exposed area) more than 3.7 times, indicating the pollutant induced-oxidative damage on the skin barrier. Whereas, the pre-applied area with the cosmetics products containing red beet revealed a decrease of 25% compared with positive control. As reports, these data demonstrated that cigarette smoke induce peroxidation of stratum corneum skin lipids. Conclusively, we suggest that anti-pollution effect of the cosmetics product containing red beet is beneficial to prevent the oxidation of skin lipids by atmospheric pollution.

• Journal of Ginseng Research
• /
• v.35 no.2
• /
• pp.235-242
• /
• 2011

To obtain microorganisms for the microbial conversion of ginsenosides in red ginseng extract (RGE), mushroom mycelia were used for the fermentation of RGE. After fermentation, total sugar contents and polyohenol contents of the RGEs fermented with various mushrooms were not a significant increase between RGE and the ferments. But uronic acid content was relatively higher in the fermented RGEs cultured with Lentus edodes (2155.6 ${\mu}g/mL$), Phelllinus linteus (1690.9 ${\mu}g/mL$) and Inonotus obliquus 26137 and 26147 (1549.5 and 1670.7 ${\mu}g/mL$) compared to the RGE (1307.1 ${\mu}g/mL$). The RGEs fermented by Ph. linteus, Cordyceps militaris, and Grifola frondosa showed particularly high levels of total ginsenosides (20018.1, 17501.6, and 16267.0 ${\mu}g/mL$, respectively). The ferments with C. militaris (6974.2 ${\mu}g/mL$), Ph. linteus (9109.2 ${\mu}g/mL$), and G. frondosa (7023.0 ${\mu}g/mL$) also showed high levels of metabolites (sum of compound K, $Rh_1$, $Rg_5$, $Rk_1$, $Rg_3$, and $Rg_2$) compared to RGE (3615.9 ${\mu}g/mL$). Among four different RGE concentrations examined, a 20 brix concentration of RGE was favorable for the fermentation of Ph. linteus. Maximum biotransformation of ginsneoside metabolites (9395.5 ${\mu}g/mL$) was obtained after 5 days fermentation with Ph. linteus. Maximum mycelial growth of 2.6 mg/mL was achieved at 9 days, in which growth was not significantly different during 5 to 9 days fermentation. During fermentation of RGE by Ph. linteus in a 7 L fermenter, $Rg_3$, $Rg_5$, and $Rk_1$ contents showed maximum concentrations after 5 days similar to flask fermentation. These results confirm that fermentation with Ph. linteus is very useful for preparing minor ginsenoside metabolites while being safe for foods.

• Journal of Korean Society of Environmental Engineers
• /
• v.22 no.1
• /
• pp.11-19
• /
• 2000

In order to predict the performance of biological wastewater treatment plant, the kinetic parameters and stoichiometric coefficient must be known. The theories and experimental procedures for determining the biological kinetic parameters were discussed in this study. Respirometric analysis in the batch reactor was carried out for the experimental assessment of kinetic parameters. A simple procedure to estimate kinetic parameters of heterotrophs and autotrophs under aerobic condition was presented. The difficulties in the interpretation of COD and VSS measurements encouraged the conversion of respirometric data to growth data. Maximum specific growth rate, yield coefficient, half saturation constant and decay rate of heterotrophic biomass were obtained from OUR(Oxygen Uptake Rate) data. Maximum specific growth rate of autotrophic biomass was obtained from the increase of nitrate concentration. The aim of this paper is to estimate the kinetic parameters of heterotrophic and autotrophic biomass by means of the respirometric analysis of activated sludge behavior in the batch reactors. These procedures may be used for the activated sludge modeling with complex kinetic parameters.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.10 no.3
• /
• pp.145-153
• /
• 2005

I reviewed an ecological and environmental significance of microbial carbon respiration coupled to dis-similatory reduction of fe(III) to Fe(II) which is one of the major processes controlling mineralization of organic matter and behavior of metals and nutrients in various anaerobic environments. Relative significance of Fe(III) reduction in the mineralization of organic matter in diverse marine environments appeared to be extremely variable, ranging from negligible up to $100\%$. Cenerally, Fe(III) reduction dominated anaerobic car-bon mineralization when concentrations of reactive Fe(III) were higher, indicating that availability of reactive Fe(III) was a major factor determining the relative significance of Fe(III) reduction in anaerobic carbon mineralization. In anaerobic coastal sediments where $O_2$ supply is limited, tidal flushing, bioturbation and vegetation were most likely responsible for regulating the availability of Fe(III) for Fe(III) reducing bacteria (FeRB). Capabilities of FeRB in mineralization of organic matter and conversion of metals implied that FeRB may function as a useful eco-technological tool for the bioremediation of anoxic coastal environments contaminated by toxic organic and metal pollutants.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.41 no.4
• /
• pp.375-382
• /
• 2015

Ginsenosides (ginseng saponin) as the one of important pharmaceutical compounds of ginseng and is responsible for the pharmacological and biological activities. These ginsenoside produces diverse small molecules ginsenoside which have more pharmacological activities including anti-wrinkle, anti-cancer and anti-oxidant effects. In the present study, we isolated bacteria using esculin agar, to produce ${\beta}$-glucosidase, and we focused on the bio-transformation of ginsenoside. Phylogenetic tree analysis was performed by comparing the 16S rRNA sequences; we identified the strain as Stenotrophomonas rhizopilae strain GFC09. In order to determine the optimal conditions for enzyme activity, the crude enzyme was incubated with 1 mM ginsenoside $Rb_1$. Bioconversion of ginsenoside $Rb_1$ were analyzed using TLC and HPLC. The crude enzyme hydrolyzed the ginsenoside $Rb_1$ along the following pathway: LB: $Rb_1{\rightarrow}Rd{\rightarrow}F_2$ into compound K, TSB: $Rb_1{\rightarrow}Rd{\rightarrow}F_2$. The structure of the hydrolyzed metabolites were identified by NMR. The activity screening tests showed that the conversion product induced the production of type I procollagen in a dose-dependent manner. These results suggested that hydrolyzed ginseng product containing the ginsenoside $F_2$ and compound K could be useful as an active ingredient for wrinkle-care cosmetics.

• Journal of Animal Science and Technology
• /
• v.63 no.6
• /
• pp.1328-1343
• /
• 2021

The effect of Multi-Carbohydrase (MC) supplementation on growth performance, visceral organ weights, blood metabolites, jejunum morphology, nutrient digestibility, and carcass parameters of broiler chickens fed nutrient-deficient corn soybean-meal based diets containing high levels of non-starch polysaccharides from wheat and wheat by-products was investigated. A total of 378 one-day-old Ross 308 broiler chickens were randomly assigned to one of seven dietary treatments to give six replicates per treatment (nine birds per pen). Dietary treatments were as follows: (1) positive control (PC; commercial standard diet); (2) negative control 1 (NC-1; PC-120 kcal/kg metabolizable energy); (3) NC-2 (PC-3% standardized ileal digestibility [SID] amino acids). The remaining four dietary treatments were formulated with the addition of MC (MC; Superzyme-CS^TM) into two negative controls along with two supplementation levels of MC (i.e., 0.025% and 0.05%, respectively). Improved body weight, average daily gain, and feed conversion ratio (p < 0.05) were observed in broiler chickens fed a reduced energy diet supplemented with MC compared to birds fed NC-1 diet from days 1-35. Additionally, birds fed a reduced energy diet with 0.05% MC showed comparable (p > 0.05) growth performance with birds fed PC for 35-day post-hatch. Furthermore, the addition of MC into reduced amino acid diets improved (p < 0.05) growth performance. Broiler chickens fed MC supplemented nutrient-deficient diets showed a greater (p < 0.05) villus height to crypt depth ratio than birds fed diets without MC on days 21 and 35. Similarly, improved (p < 0.05) nutrient digestibility was observed in birds fed reduced energy diets supplemented with MC compared to birds fed NC-1 on days 21 and 35. Our results suggest that MC supplementation into reduced energy or reduced amino acid diets containing wheat and wheat by-products has the potential to improve growth performance and nutrient digestibility while maintaining healthier gut morphology in broiler chickens from 1 to 35 days of age.