• Transactions of the Korean Society of Automotive Engineers
• /
• v.22 no.5
• /
• pp.20-28
• /
• 2014

The high velocity oxygen fuel spraying (HVOF) is a kind of surface modification process technology to form the sprayed coating layer after spraying the powder to molten or semi-molten state by the ultra-high speed at the high-temperature heat source and conflicting with a substrate. It is desirable to melt completely the thermal spray powder in order to produce the coating layer with an optimal adhesion, however, because a semi-molten powder in a spray process has the low efficiency and become a factor that degrades the mechanical property by the inducement of pore-forming within the coating layer. To improve the wear resistance, corrosion resistance and heat resistance, in this study, the plungers of high-speed and ultra-high pressure reciprocating hydraulic pumps for oil and water used in ironwork are produced with $420J_2$ and the coating layers of plungers are formed by the powders of WC-Co-Cr and WC-Cr-Ni including the high hardness WC. The surface of these plungers is modified by the super-mirror face grinding machine using variable air pressure developed in this laboratory, and then the characteristics of cross-sectional microstructure, and surface roughness and hardness values between no operation and 100 days-operation are examined and made a comparison. The fine tops and bottoms on surface roughness curve of oil-hydraulic pump plunger sprayed by WC-Cr-Ni are molded more and higher than those of water-hydraulic pump sprayed by WC-Co-Cr because the plunger diameter of oil-hydraulic pump is 0.4 times smaller than that of water-hydraulic pump and the pressure of oil-hydraulic pump exerted on the plunger is operated with the 70 bars higher than that of water-hydraulic pump. As a result, it is found that the values of centerline average surface roughness and maximum height for oil-hydraulic pump plunger are bigger than those of water-hydraulic pump plunger.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.45 no.6
• /
• pp.797-804
• /
• 2016

In an acute toxicity test for Chrysanthemum indicum Linne, 0.5~10 g/kg of Chrysanthemum indicum Linne extracts were administered. Chrysanthemum indicum Linne did not produce acute toxicity even at high doses of 10 g/kg, making it a highly safe material. In the chronic toxicity test, oral administration of Chrysanthemum indicum Linne up to 2 g/kg was carried out for 13 weeks, showing liver non-toxicity. The gout inhibitory effect of Chrysanthemum indicum Linne extracts was measured by inflammatory cytokine expression and foot thickness after 24 h of monosodium urate crystal (MSU) oral administration when inflammatory cytokine production reached a maximum. The group administered 2~4 g/kg of Chrysanthemum indicum Linne extract showed an inhibitory effect on gout inflammation and edema, whereas the 10 g/kg administered group showed an increase in inflammation. Therefore, the moderate concentration of Chrysanthemum indicum Linne extract for gout inhibitory effect was under 4 g/kg. Chrysanthemum indicum Linne extract showed an anti-inflammatory effect on MSU as a relatively safe material at high capacity. These results indicate that Chrysanthemum indicum Linne extract is thought to be an excellent substance for gout prevention.

• Journal of the Mineralogical Society of Korea
• /
• v.25 no.3
• /
• pp.123-130
• /
• 2012

Leaching experiments of gold and silver from roasted concentrate were carried out using a chlorine-hypochlorite solution. The leaching rate of gold was 75% at 1.5:1 ratio of chlorine and hypochlorite and increased to 81% with adding 1 M NaCl. However, at 1% pulp density and at $65^{\circ}C$, the leaching rates of Au were close to 100%. XRD analysis identified quartz in the solid residues after digestion of roasted concentrate with aqua regia or chlorine-hypochloride leaching solution. This suggests that the gold may not be leached out of the quartz in aqua regia or chlorine-hypochlorite solution. In order to leach the gold from the quartz, the concentrate will have to be pre-treated through ultra-fine grinding or treated with stronger oxidative agents.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.39 no.2
• /
• pp.287-293
• /
• 2010

Regarding the physical properties of wheat flour added with lily's root powder, elasticity in farinograms tended to increase as the ratio of added lily's root powder increased. However, viscoelasticity, absorptivity, absorption time, and stability tended to decrease after an initial increase when a certain ratio of lily's root powder was added to the wheat flour. Results from the rapid viscosity analyzer (RVA) indicated that the retention strength, final viscosity, break down, set back value, $P_{max}$ value of the alveogram, and falling number value decreased. As for gaseous release, measured with a rheofermentometer, the total amount of $CO_2$ gas generated and retained tended to decrease. As for the gelatinizing properties in terms of differences in the granularity and the amount of lily's root powder (bulbs) added to wheat flour, the initial gelatinization temperature had no effect regardless of the type or amount of general grinding and minute (ultra-fine, $10\;{\mu}m$) lily's root powder. Meanwhile, the peak viscosity and peak viscosity time exhibited significant differences in 3, 5% general grinding lily's root powder additive groups. On the other hand, there was no significant difference between 3, 5% minute lily's root powder additive groups. This is likely because the activity of the enzyme in wheat flour decreased relatively and differences in the lily's root powder granularity resulted in a variation in water absorptivity. In the preference test, flavor retention of the functional bread increased according to the granularity of lily's root powder and the ratio of added lily's root powder, thus resulting in significant differences in the mouth feel and flavor; the texture and crumb color, however, did not exhibit significant differences.

• Food Science and Preservation
• /
• v.23 no.1
• /
• pp.20-26
• /
• 2016

In this study, the anti-inflammatory effect of hyaluronidase (HAase) inhibition was determined from 92 species of oriental herbal medicine extracted with water and ethanol solvents because of their non-toxicity in the human body. The water extracts of Evodia officinalis (86.8%), Thuja orientalis (80.8%), Carthami semen (66.5%), Melia azedarach (74.7%), Siegesbeckia pubescens (61.3%), Saururus chinensis (49.15%) showed a relatively greater anti-inflammatory activity. The ethanol extracts of Ailanthus altissima and Saururus chinensis demonstrated the highest anti-inflammatory effect at above 90%. Saururus chinensis was selected for its high anti-inflammatory effect in both water and ethanol extract. Ethanol was more effective than water and optimal extraction conditions for phenolic compounds was determined to be extraction with 50% ethanol for 12 hours. The extracts from Saururus chinensis in optimal condition showed 70~80% anti-inflammatory effect when $100{\sim}250{\mu}g/mL$ phenolic concentration was treated. Concentration of above $500{\mu}g/mL$ decreased the inhibitory effect. The anti-inflammatory effect and extraction yield were increased by ultra-fine grind technology, indicating that this method can be used to increase the extraction yield of phenolic compounds from medicinal plants.