• Resources Recycling
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• v.9 no.6
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• pp.36-44
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• 2000

Fly ash was composed of the unburned carbon and mineral particles. The former was able to attach on the bubbles, while the latter was not. Therefore, it was possible to separate the unburned carbon and the mineral from fly ash using the froth flotation process. This study was carried out to evaluate the separation efficiency as a function of the ny ash particle properties in the column flotation. Separation efficiency was analyzed for various size fraction of -38 fm,38~125 fm and 1125 W, and for various fly ash samples containing 7, 11, and 20 wt% unburned carbon. For the size fractions of -38 fm containing 7 wt% unburned carbon, separation efficiency was 86ft, whereas separation efficiency was found to be 74% for the size fraction of +125$\mu\textrm{m}$ containing 20 wt% unburned carbon. The results indicated that separation efficiency increased with the decrease in the particle size and the unburned carbon content of the fly ash.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.1
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• pp.14-19
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• 2007

This study was conducted to analyze the antioxidant activity and xanthine oxidase inhibitory effect of hot-water extracts from Elaeagnus multiflora Thunb. to provide fundamental data for the development of functional materials. The antioxidative activities of hot-water extracts from E. multiflora Thunb. were analyzed by electron donating ability (EDA) using 1,1-diphenyl-2-picryl hydrazyl (DPPH), superoxide dismutase (SOD) -like activity by pyrogallol and nitrite scavenging ability. EDA of extracts from unripe, ripe, and overripe fruits were 77.7%, 36.0%, and 23.7% at 100 ${\mu}g/mL$, respectively, and EDA of extract in unripe fruits was higher than those of others. At 1,000 $\mu$g/mL, the SOD-like activities were 32.8%, 11.2% and 5.0% for unripe, ripe, and overripe fruits, respectively. The SOD-like activity was increased along with the increase of unripe and ripe extract concentrations. The nitrite scavenging ability of unripe fruit extracts in 100, 300, 500 ${\mu}g/mL$ of extraction solution in pH 1.2 and 3.0 was higher than those of others. The nitrate scavenging ability of all extracts was decreased according to the increase of pH. Xanthine oxidase inhibitory activities of unripe, ripe and overripe fruits were 30.0%, 28.2%, and 18.2% at 1,000 ${\mu}g/mL$, respectively.

• Korean Journal of Dental Materials
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• v.45 no.4
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• pp.257-274
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• 2018

The purpose of this study was to evaluate the effect of acid-treatment conditions on the surface properties of the RBM (Resorbable Blast Media) treated titanium. Disk typed cp-titanium specimens were prepared and RBM treatments was performed with calcium phosphate ceramic powder. Acid solution was mixed using HCl, $H_2SO_4$ and deionized water with 4 different volume fraction. The RBM treated titanium was acid treated with different acid solutions at 3 different temperatures and for 3 different periods. After acid-treatments, samples were cleaned with 1 % Solujet solution for 30 min and deionized water for 30 min using ultrasonic cleanser, then dried in the electrical oven ($37^{\circ}C$). Weight of samples before and after acid-treatment were measured using electric balance. Surface roughness was estimated using a confocal laser scanning microscopy, crystal phase in the surface of sample was analyzed using X-ray diffractometer. Surface morphology and components were evaluated using Scanning Electron Microscope (SEM) with Energy Dispersive X-ray spectroscopy (EDX) and X-ray Photoemission Spectroscopy (XPS). Values of the weight changes and surface roughness were statistically analyzed using Tukey-multiple comparison test (p=0.05). Weight change after acid treatments were significantly increased with increasing the concentration of $H_2SO_4$ and temperature of acid-solution. Acid-treatment conditions (concentration of $H_2SO_4$, temperature and time) did not produce consistent effects on the surface roughness, it showed the scattered results. From XRD analysis, formation of titanium hydrides in the titanium surface were observed in all specimens treated with acid-solutions. From XPS analysis, thin titanium oxide layer in the acid-treated specimens could be evaluated. Acid solution with $90^{\circ}C$ showed the strong effect on the titanium surface, it should be treated with caution to avoid the over-etching process.

• Korean Journal of Dental Materials
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• v.44 no.2
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• pp.171-178
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• 2017

The purpose of this study is to investigate the effect of number of times dipped in coloring liquid and sintering temperature on the flexural strength of zirconia ceramic. In this study, using a zirconia block having improved transparency, specimens with size of $25mm{\times}2mm{\times}1.5mm$ were fabricated. The zirconia ceramic specimens were divided into three groups according to the number of times dipped in coloring liquid by 0, 2 and 4 times, and dyed in the coloring liquid to give color to each specimen. Then, after sintering them at the final temperature of $1,450^{\circ}C$ and $1,600^{\circ}C$, flexural strength was measured using a universal testing machine (total 6 group, n=10 for each group). Also, a scanning electron microscopy (SEM) was performed to observe its microstructure, and the data obtained through the experiment were analyzed with two-way ANOVA. The results of the flexural strength analysis show that the highest value was measured $762.3{\pm}42.3MPa$ in EKL2 group, while the lowest value was $516.4{\pm}77.1MPa$ in EKH4 group. According to the results of the two-way ANOVAs, flexural strength was not related with interaction between sintering temperature and number of times dipped in coloring liquid ($R^2=0.737$). However, there were statistically significant differences in flexural strength depending on sintering temperature (P<0.001). The flexural strength of zirconia ceramics having improved transparency was dependent on sintering temperature. The number of times dipped in the coloring liquid did not affect flexural strength of the zirconia ceramic having improved transparency.

• Journal of Radiation Industry
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• v.7 no.1
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• pp.7-14
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• 2013

In this study, we investigated the applicability of the photostimulated luminescence (PSL), thermoluminescence (TL) and electron spin resonance (ESR) methods for various foods. The analysed samples consist of 11 items including dried fruits (6 items) and mushrooms (5 items). To compare between non-irradiated and irradiated food, all samples were irradiated with $^{60}Co$ gamma-ray source. In PSL study, the photon counts of all the unirradiated sample were identified negative (lower than 700). The photon counts irradiated (1, 5, 10 kGy) dried date-palm, dried jujube and mushrooms (Auricularia auricula, Phellinus linteus and Sarcodon aspratus) showed positive (higher than 5,000) and the results for the other samples were negative or intermediate (>700 and >5,000). In TL analysis most of items can be applicable to detect irradiated foods because of showing TL ratio above 0.1. The glow curves by TL method were estimated in the range of $150{\sim}250^{\circ}C$ in irradiated samples. In ESR measurements, the intensity of ESR signal (single-line) increased as the dose of irradiation increased. In particular, the specific ESR signals of irradiation-induced radical were detected in dried papaya, dried date-palm, dried banana, dried pineapple and S. aspratus. According to the results, PSL, TL and ESR methods were successfully applied to detect the irradiated foods. It is concluded that PSL, TL and ESR methods are suitable for detection of irradiated samples and a combined method is recommendable for enhancing the reliability of detection results.

• Journal of Radiation Industry
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• v.7 no.1
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• pp.69-74
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• 2013

This study examined radiation detection characteristics of spices (cumin, caper and turmeric), other small fruits (hut-gae berry and boxthorn), and pollen extract product. Each samples were irradiated at dose of 1, 5, and 10 kGy and analyzed by the thermoluminescence (TL) and electron spin resonance (ESR) methods. To compare between non-irradiated and irradiated food, all samples were irradiated with $^{60}Co$ gamma-ray source. In TL analysis, most of samples could be applied to detect irradiated foods because of showing TL ratio above 0.1. The glow curves examined by TL method were estimated in the range of $150{\sim}250^{\circ}C$ in irradiated samples. In ESR measurements, the intensity of ESR signal (single-line) increased as the increase of irradiation dose. In particular, the specific ESR signals of irradiation-induced radical were detected in hut-gae berry and pollen extract product. As a results, it is considered that TL and ESR methods can be used to detect both hut-gae berry and pollen extract product. But cumin, caper, turmeric and boxthorn irradiated with gamma ray could be detected only by TL method. It is concluded that TL and ESR methods are suitable for detection of irradiated samples and a combined method is recommendable for enhancing the reliability of detection results.

• Food Engineering Progress
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• v.13 no.3
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• pp.203-210
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• 2009

In this study, antioxidant activity and quality characteristics of egg yolk mayonnaise and soy milk mayonnaise containing soybean paste powder were assessed. The mayonnaise with egg yolk as an emulsifier is E group according to the amount of soybean paste powder addition of 0% (E1), 3% (E2), 6% (E3) and mayonnaise with soy milk as an emulsifier is S group with soybean paste powder addition of 0% (S1), 3% (S2), 6% (S3). Total phenol content and electron donating ability of mayonnaise were increased as the amount of the soybean paste powder increased. L value of Hunter's color was decreased, but a value and b value were increased as the amount of the soybean paste powder increased. Soy milk mayonnaise showed very low cholesterol content than egg yolk mayonnaise. In sensory evaluation, S2 received the highest scores for flavor, overall taste and preference. Base on these results, soybean paste powder showed significant antioxidant activity in mayonnaise and cholesterol content was successfully decreased in soy milk mayonnaise compared to egg yolk mayonnaise. The soy milk mayonnaise with soybean paste powder will be a possible model to introduce our traditional food to the worldwide food item, such as mayonnaise.

• Food Engineering Progress
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• v.14 no.1
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• pp.1-6
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• 2010

Fruit wine from Acanthopanax sessiliflorus(A. sessiliflorus) including many pharmacological components was manufactured and its functional properties were investigated. The fruit part of A. sessiliflorus contained 75.74${\pm}$0.49%(w/w) moisture, 12.51${\pm}$1.23%(w/w) crude protein, 4.20${\pm}$0.51.%(w/w) crude fat and 5.21${\pm}$1.64%(w/w) crude ash. Minerals of fruit were potassium(12.94${\pm}$0.08 mg/g), calcium(1.53${\pm}$0.06 mg/g) and magnesium(1.12${\pm}$0.05 mg/g). Initial soluble solid and fermentation temperature were 24-30$^{\circ}$Brix and 20${^{\circ}C}$ for manufacturing fruit wine from A. sessiliflorus. When initial soluble solid of a must was adjusted to more than 30$^{\circ}$Brix, ethanol production was suppressed slightly. The polyphenol content of the fruit wine fermented at 20${^{\circ}C}$(125.24${\pm}$1.86 mg/mL) was higher than those at 25${^{\circ}C}$(99.69${\pm}$2.11 mg/mL) and 30${^{\circ}C}$(95.55${\pm}$1.54 mg/mL). Electron donating activities of wines fermented at 20, 25 and 30${^{\circ}C}$ were 85.9${\pm}$2.3, 55.7${\pm}$2.5 and 55.2${\pm}$3.4%, respectively. The content of eleutheroside B increased up to 146.58${\pm}$4.10 $\mu$g/mL during fermentation. There was no significant effect of fermentation temperature on eleutheroside B content. The fruit part of A. sessiliflorus can be used as a valuable resource for development of nutraceutical foods.

• Journal of agriculture & life science
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• v.44 no.2
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• pp.39-48
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• 2010

In order to develop the high quality kanjang in which a functionality is strengthened, the physicochemical properties and antioxidant activities of Korean traditional kanjang and garlic-added kanjang were compared and analyzed. Of color, lightness (L) and redness (a) value were not significant difference between a sample, but yellowness (b) value was higher than garlic-added kanjang. Moisture and crude protein contents were not significantly different, content of crude lipid and ash was higher than traditional kanjang. The pH were 5.02 and 4.91 in traditional and garlic-added kanjang, respectively. The salinity was $20.97{\pm}0.15%$ in garlic-added kanjang, that was significantly lower in garlic-added kanjang. The reducing sugar and total sugar contents were significantly higher in garlic-added kanjang. Na content was occupies 87~89% of total mineral content. The contents of total amino acids were 1,564.02 mg% and 1,932.41 mg% in traditional and garlic-added kanjang, respectiveluy. Also free amino acid was higher in garlic-added kanjang (484.43 mg%) than traditional kanjang (461.13 mg%). The antioxidant activities were increased in a does-dependent manner. In $100{\mu}L/mL$ concentration, electron donating abilities were $14.43{\pm}0.25%$ and $54.6{\pm}1.48%$ in traditional and garlic-added kanjang, ABTs radical scavenging activities of garlic-added kanjang was $57.21{\pm}1.34%$ that was higher than traditional kanjang ($43.27{\pm}0.19%$).

• Journal of the Society of Cosmetic Scientists of Korea
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• v.26 no.1
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• pp.149-162
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• 2000

Coenzyme Q10 is found in all tissues including skin and it is the well-known coenzyme for mitochondrial enzymes. The electron and proton transfer functions of the quinone ring are of fundamental importance for the oxidative phosphorylation pathway to generate energy in the cells. Coenzyme Q10 has been studied as a potent antioxidant molecule in the skin. It is involved in the skin's response to UVR irradiation. The concentration of this antioxidant in UVR exposed skin is higher than in non-exposed skin. However, recent studies have also shown that coenzyme Q10 is one of the first antioxidants to be depleted when skin is UVR-irradiated. This indicates that coenzyme Q10 is primarily involved in defense mechanisms of the skin. Therefore, we questioned whether coenzyme Q10 shows reulatory effect of melanogenesis. Here we report that coenzyme Q10 inhibits melanin neosynthesis of normal human melanocytes grown in culture, and lightens UVB-induced hyperpigmentation of the guinea pig skin in vivo. We treated human melanocytes with 0.05mM to 0.5mM of coenzyme Q10 for a total of two days. This inhibited melanin neosynthesis of cultured human melanocytes dose-dependently. The inhibitory effect of coenzyme Q10 was as effective as kojic acid or vitamin C on cultured human melanocytes. CoQ10 didn't have direct inhibitory effect on tyrosinase activity in in vitro tyrosine hydroxylase activity To further clarify the effect of coenzyme Q10 on the melanogenesis, we established UVB-induced hyperpigmentation on the shaved backs of brownish guinea pigs. The UVB intensity was 500mJ/$\textrm{cm}^2$ and the total energy dose was 1,500 mJ/$\textrm{cm}^2$. The animals were exposed to UVB radiation one times a week for three consecutive weeks. Coenzyme Q10, kojic acid, Arbutin, vitamin C(1% in vehicle) or vehicle alone as a control were then topically applied daily to the hyperpigmented areas twelve times per week far four successive weeks. The lightening effect was evaluated by visual scoring, chromameter and immunohistochemistry. Coenzyme Q10 had lightening effect on the UVB-induced hyperpigmentation without any other side effects, whereas another compounds showed weak lightening efficacies. Therefore, these results suggest that coenzyme Q10 may be useful for solving physiological hyperpigmenting problems for cosmetic purposes.