• Asian-Australasian Journal of Animal Sciences
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• v.17 no.3
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• pp.337-342
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• 2004

A non-ionic surfactant, Tween 80 has been known to exert a number of positive effects on degradative enzymes in in vitro aerobic and anaerobic microbial cultures. An experiment was conducted to examine effects of supplementation of Tween 80 on ruminal fermentation and nutrient digestibility of Hanwoo steers. The experiment was designed as a $3{\times}3$ Latin square with duplication and six Hanwoo steers with rumen cannulae, average weight 497 (SE 61.1) kg. For the experiment the animals were given a basal diet consisting of rice straw and compound feed mixed at 4:6 ratio. The three experimental treatments were (1) the basal diet, supplemented with (2) 5 g/d Tween 80 and (3) 10 g/d Tween 80. Ruminal pH was significantly (p<0.05) affected by Tween 80 supplementation at 6 h after feeding. Increasing supplementation levels of Tween 80 linearly increased the total VFA concentration. CMCase activity by the 10g/d supplementation of Tween 80 were significantly increased (p<0.05) by 24.4% compared with that of control. Digestibility of crude fiber was significantly increased (p<0.05) in Hanwoo steers fed the diet supplemented with 10 g/d Tween 80 compared with those of control, whilst digestibility of ether extract (EE) was linearly increased by increasing Tween 80 supplementation level (p<0.05). In other nutrient components, their digestibilities of Hanwoo fed diets supplemented with Tween 80 tended to increase. It is concluded that Tween 80 has a potential for industrial application as a feed additive to improve ruminant production.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.5
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• pp.653-658
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• 2017

To evaluate the effects of amylose content and dissolution media on the molecular structure of maize starch, changes in the hydrodynamic diameter of starch molecules were assessed via dynamic light scattering depending on amylose content and dissolution media. As the amylose content of starch increased, the hydrodynamic diameter of starch molecules proportionally decreased from 204 to 92 nm. To alter ionic strength, hydrogen bonding, or polarity of dissolution media, various contents of NaCl (1, 2, or 3 M), urea (1, 2, or 3 M), or 1-butanol (0.1, 0.5, or 1.0%) were added to media, respectively, resulting in increased hydrodynamic diameter of starch. However, the degree of expansion was dependent on amylose content and the concentration and/or type of additive. The hydrodynamic diameter of starch molecules exhibited significant correlation with amylose content obtained by size exclusion chromatography, regardless of dissolution conditions.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.15 no.1
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• pp.16-20
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• 2005

In order to improve electrical conductivity and mechanical properties of 8YSZ SOFC electrolyte material, we used Al₂O₃ as an additive and applied the spark plasma sintering (SPS) method. The sintered bodies were densified above 96 ％ of theoretical density at 1200℃ and possessed microstructures composed of homogeneous grains less than 1 ㎛ in size. The addition of Al₂O₃ improved fracture toughness and bending strength by inhibiting grain growth of 8YSZ and increased total ionic conductivity because grain interior conductivity appeared to remain constant and grain boundary conductivity increased. It was assumed that the dissolution of Al₂O₃ into 8YSZ which was inevitable problem at commercial sintering method was effectively prohibited by the SPS technique with a relatively low sintering temperature and the reaction between Al₂O₃ and SiO₂ present at grain boundary to produce the crystalline Al/sub 2-x/Si/sub l-y/O/sub 5/ phase, resulting in the increase of grain boundary conductivity.

• Journal of Energy Engineering
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• v.19 no.2
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• pp.116-120
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• 2010

Overall total length of hydraulic pipe to transport the hot water in the domestic district heating network is above 3,000 Km approximately. This long pipe network requires a lots of the transport pumping power by surface friction of fluid. In this study, the drag reduction(DR) of Amin Oxide $C_{18}$ as non-ionic surfactant according to the fluid velocity, temperature and surfactant concentration under the condition of above $80^{\circ}C$ fluid temperature were investigated experimentally. Results showed that new amin oxide $C_{18}$ surfactant had DR of maximum 30% in fluid temperature of $80^{\circ}C$ and had 15% DR in fluid temperature over $100^{\circ}$ under short time test condition. And amine oxide had 155 hours duration time to keep the DR characteristic in the fluid temperature of $80^{\circ}$ and 1000 ppm concentration. But duration time of DR was decreased when fluid temperature increased.