• Progress in Medical Physics
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• v.20 no.2
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• pp.80-87
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• 2009

Phase transformation, superelastic characteristics and variation of surface residual stress were studied for Nitinol shape memory alloy through application of UNSM technology, and life extension methods of stent were also studied by using elastic resilience and corrosion resistance. Nitinol wire of ${\phi}1.778$ mm showed similar surface roughness before and after UNSM treatment, but drawing traces and micro defects were all removed by UNSM treatment. It also changed the surface residual stress from tensile to compressive values, and XRD result showed less intensive austenite peak and clear martensite and additional R-phase peaks after UNSM treatment. Fatigue resistance could be greatly improved through removal of surface defects and rearrangement of surface residual stress from tensile to compressive state, and development of surface modification system to improve not only bio-compatability but also resistance to corrosion and wear will make it possible to develop vascular stent which can be used for circulating system diseases which run first cause of death of recent Koreans.

• Journal of Animal Science and Technology
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• v.46 no.1
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• pp.39-48
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• 2004

This experiment was conducted to investigate the effect of continuous feeding of probiotics on growth performance, nutrient digestibility, blood urea nitrogen(BUN) and immune responses in pigs. Treatments were 1) Control(basal diet), 2) P-O.l(basal diet + 0.1% probiotics) and 3) P-0.2(basal diet + 0.2% probiotics). In growth trial, a total of sixty pigs(6.17 $\pm$ 0.45 kg average body weight) weaned at 21 days of age were used. All pigs were assigned according to sex and body weight, and each treatment had 5 replicates of 4 pigs per pen in a randomized complete block(RCB) design. During 0${\sim}$8 weeks, there was no significant difference in average daily gain(ADG), average daily feed intake(ADFI) and gain:feed ratio(GfF) among treatments. During 9 - 20 weeks, ADG was improved significantly in pigs fed P-O.I or P-0.2 diets when compared to the pig fed control diet(P <0.05), but there was no significant difference in ADFI and GfF ratio. During overall period, ADG, ADFI and GfF ratio were not significantly different among treatments. In the first metabolic trial(17.93 $\pm$1.45kg average body weight), apparent digestibility of OM, protein, fat in pigs fed P-O.l and P-0.2 diets were greater than in pigs fed control diet(P <0.05) and ash digestibility in pigs fed P-0.2 diet was significantly higher than in pigs fed control diet(P <0.05). Calcium digestibility in pigs fed P-0.2 diet was significantly higher than in pigs fed control and P-O.I diets(P <0.05). Fecal-N excretion was lower in pigs fed P-O.! and P-0.2 diets than in pigs fed control(P <0.05). In the second metabolic trial(41.80 $\pm$ 2.68kg average body weight), there was no significant difference among treatments in apparent digestibility of nutrients and N-retention. In blood assay for the BUN and immune responses investigations, there was no significant difference among treatments during overall period of experiment. Therefore, this experiment suggested that probiotics supplementation could improve growth performance and nutrient digestibility of pigs.

• Food Science and Preservation
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• v.18 no.4
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• pp.442-458
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• 2011

Among Cucubitaceae, melon (Cucumis melo) is one of the most diversified fruits, with various forms, sizes, pulps, and peel colors, In addition, it is a commercially important crop because of its high sweetness, deep flavor, and abundant juice. In the species, there are both climacteric and non-climacteric melons depending on the respiration and ethylene production patterns after harvest. Ethylene is also considered a crucial hormone for determining sex expression, Phytohormones other than ethylene interact and regulate ripening, There are some indices that can be used to evaluate the optimum harvest maturity. The harvest time can be estimated after the pollination time, which is the most commonly used method of determining the harvest maturity of the fruit. Besides the physiological aspects, the biochemical alterations, including those of sweetness, firmness, flavor, color, and rind, contribute to the overall fruit quality. These changes can be categorized based on the ethylene-dependent and ethylene-independent phenomena due to the ethylene-suppressed transgenic melon. After harvest, the fruits are precooled to $10^{\circ}C$ to reduce the field heat, after which they are sized and packed. The fruits can be treated with hot water ($60^{\circ}C$ for 60 min) to prevent the softening of the enzyme activity and microorganisms, and with calcium to maintain their firmness. 1-methylenecyclopropene (1-MCP) treatment also maintains their storability by inhibiting respiration and ethylene production. The shelf life of melon is very short even under cold storage, like other cucurbits, and it is prone to obtaining chilling injury under $10^{\circ}C$. In South Korea, low-temperature ($10^{\circ}C$) storage is known to be the best storage condition for the fruit. For long-time transport, CA storage is a good method of maintaining the quality of the fruit by reducing the respiration and ethylene. For fresh-cut processing, washing with a sanitizing agent and packing with plastic-film processing are needed, and low-temperature storage is necessary. The consumer need and demand for fresh-cut melon are growing, but preserving the quality of fresh-cut melon is more challenging than preserving the quality of the whole fruit.