• Journal of Chest Surgery
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• v.37 no.10
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• pp.839-844
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• 2004

Background: The Y-composite graft of internal thoracic artery and radial artery is commonly used in coronary bypass surgery. The aim of this study is to look for a way to raise the free flow of the internal thoracic graft and to see flow dynamics of the Y-graft. Material and Method: In 15 patients undergoing coronary bypass surgery, free flow of the in-situ internal thoracic artery graft was measured using two different papaverine application methods; extraluminal papaverine spray in 7 patients and intraluminal papaverine injection in 8. In 18 other patients for whom the Y-graft was used, total free flow and flow changes from the two ends were measured. Result: The free flow of the in-situ internal thoracic artery graft almost doubled with internal papaverine injection than with external papaverine spray $(47.7\pm9.6$ mL/min $vs.100.8\pm26.3$ mL/min, p<0.001). Total flow of the Y-composite graft was significantly more than either flow of the internal thoracic artery end or radial artery graft end $(173.3\pm45.3$ mL/min vs. $121.1\pm34.3$ mL/min or $117.5\pm42.8$ mL/min). When both ends of the Y-composite graft were opened, free flows from the two ends were similar $(85.4\pm27.8$ mL/min vs: $87.9\pm42.4$ mL/min, p=0.772). The flow of one end of the Y-composite graft was increased significantly by clamping of the other-end than when both ends were opened. Conclusion: Intraluminal papaverine injection is very effective in raising free flow of the internal thoracic artery graft, and the free flow of the Y-composite graft of in-situ internal thoracic artery and free radial artery graft is more than that of the in-situ internal thoracic artery graft. The flow of one end flow of the Y-graft may be altered by the flow change of the other end.

• Korean Chemical Engineering Research
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• v.54 no.2
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• pp.234-238
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• 2016

Solid ash-free coal (AFC) samples recovered from solvent-extracted solution by vacuum drying, dilution precipitation and spray drying methods were compared in terms of physical properties and chemical structure. AFC was prepared by using Kideco coal (Indonesian sub-bituminous coal) and polar N-methyl-2-pyrrolidone (NMP) solvent as raw materials. The physical properties of the AFCs were characterized with proximate, ultimate, and calorific value analysis. In analyzing the chemical structure, FTIR and NMR were used. the proximate analysis showed much reduced ash in the AFCs compared to parent raw coal. The FTIR result showed that the extraction solvent was not fully removed from the AFC prepared by vacuum drying. However, the solvent was not detected in the AFC recovered by using dilution precipitation. Dilution precipitation has advantages over the other two methods, since it can be done at relatively low temperature and separate ash-free coal from extraction solvent more effectively.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.8
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• pp.1139-1144
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• 2004

In Exp. 1, a total of 36 pigs (6.55$\pm$0.10 kg average initial body weight and 21 d average age) were used in a 14 d growth study to determine the effects of replacing spray-dried plasma protein (SDPP) with spray-dried egg protein containing specific egg yolk antibody (SDEP) on growth performance and nutrient digestibility in weaned pigs. The pigs were blocked by weight and assigned to treatments based on sex. There were three pigs per pen and four pens per treatment. Dietary treatments were 0, 3, or 6% SDEP and contained 6, 3, or 0% SDPP, respectively. Through the entire experimental period, average daily gain (ADG), average daily feed intake (ADFI), and gain/feed tended to decrease as the concentration of SDEP increased in the diets. However, there were no significant differences among the treatments (p>0.05). As the addition of SDEP in the diets increased, apparent digestibilities of dry matter (DM) and nitrogen (N) were decreased without significant (p>0.05). For Exp. 2, 36 pigs (2.63$\pm$0.04 kg average initial body weight and 10 d average age) were used in a 14 d growth study to determine the effects of antibiotic replacement with SDEP on growth performance and nutrient digestibility in early-weaned pigs. The pigs were blocked by weight and assigned to treatments based on sex. There were three pigs per pen and four pens per treatment. Dietary treatments included 1) ANTIBIOTIC (corn-dried whey-soybean meal based diet+0.08% antibiotics, 4 mg of tiamuline hydrogen fumarate; 10 mg of sulfadimidine per kg of complete diet), 2) SDEP0.1 (corndried whey-SBM based diet+0.1% SDEP), and 3) SDEP0.2 (corn-dried whey-SBM based diet+0.2% SDEP). ADG and gain/feed of pigs fed the SDEP0.2 diet were higher than for pigs fed the ANTIBIOTIC diet without significant (p>0.05). Pigs fed the diet with SDEP0.2 tended to have increased apparent digestibilities of DM and N compared to pigs fed the ANTIBIOTIC diet without significant (p>0.05). In conclusion, the dietary SDEP seemed to be partial replacing the SDPP portion of high nutrient dense diet for weaned pigs. Also, dietary SDEP seemed to be approximately 0.2% or more when the pigs fed the antibiotic-free diet for early-weaned pigs.

• Journal of Environmental Science International
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• v.14 no.1
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• pp.97-103
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• 2005

Because of the toxicity of hexavelant chromium ion, treatments of metallic surface with chromate compounds to retard corrosion are undesirable for safety control in industrial uses and protection of environment. In this study, we investigated several compounds such as inorganic, organic, and polymer materials in order to sub­stitute the chromate conversion treatment on steel sheet. The corrosion property was investigated in a salt spray tester with 3.5 $wt.{\%}\;NaCI\;at\;35^{\circ}C.$ The results showed that the zirconium/silane/polymer triple coatings on the galvanized steel exhibited a significant retardation of corrosion. Although the multicoating system needs a com­plexed processing, we can confirm a possibility of development of a chromate-free chemical conversion treat­ment for galvanized steel sheet.

• Journal of ILASS-Korea
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• v.26 no.1
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• pp.1-8
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• 2021

Droplet evaporation has been known as a common phenomenon in daily life, and it has been widely used for many applications. In particular, the influence of the different heated substrates on evaporation flux and flow characteristics is essential in understanding heat and mass transfer of evaporating droplets. This study aims to simulate the droplet evaporation process by considering variation of thermal property depending on the substrates and the surface temperature. The commercial program of ANSYS Fluent (V.17.2) is used for simulating the conjugated heat transfer in the solid-liquid-vapor domains. Moreover, we adopt the diffusion-limited model to predict the evaporation flux on the different heated substrates. It is found that the evaporation rate significantly changes with the increase in substrate temperature. The evaporation rate substantially varies with different substrates because of variation of thermal property. Also, the droplet evaporates more rapidly as the surface temperature increases owing to an increase in saturation vapor pressure as well as the free convection effect caused by the density gradient.

• Journal of the Korean Ceramic Society
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• v.25 no.4
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• pp.357-363
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• 1988

Ccompaction and sintering behavior of highly pure PSZ powders were investigated by laying the stress on the granulation processes. The particle size of coprecipitated PSZ powder was so fine that the agglomeration was severely formed during drying and calcing step and by this agglomeration differential sinering was occurred. The methanol dispersion of precipitates was the good method of avoiding severe agglomeration formed during drying process because of small surface tension than water. But perfect deagglomeraton was not possible due to high surface area of powders. So homogenization by granulation was needed, and among the method spray granulation was the most desirable to obtain homogeneous compacts and subsequent flaw-free ceramics.

• Journal of Environmental Science International
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• v.12 no.7
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• pp.801-807
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• 2003

This work aims the search of environmentally friendly pre-treatment technologies to develop chromate replacements for metal finishing industries due to its toxicological properties. Since the corrosion resistance of steel was strongly related to water permeation, galvanized steel sheets were treated with various hydrophobic silane compounds and water-suspended polymer solution. Also, plasma gas discharge was applied to modify the surface of a polymer coated-steel sheet to be hydrophobic. The surface hydrophobicity of materials was introduced by CF$_3$H plasma exposure. The corrosion property before and after the plasma treatment was investigated in a slat spray tester with 3.5 wt.% NaCl at 35$^{\circ}C$. The results showed that both silane/polymer double coatings and plasma treatment of the galvanized steel exhibited significant retardation of corrosion.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.1
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• pp.47-53
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• 2011

From recent research, it has revealed that Electroacitve polymer(EAP) has a physical limitation. Carbon nanotube(CNT) is known as the promising material which has excellent electro-mechanical characteristics and is mostly defect-free. It is expected that a successful synthesis of CNT and Nafion known as a primary material for IPMC would make a great improvement on its electro-mechanic feature. In this paper, we suggest the method of synthesis of CNT with Nafion which improves electro-mechanical characteristic. Using mechanical dispersion with Nafion and Isopropyl Alcohol(IPA), we disperse Single-walled carbon nanotubes(SWCNT). For a uniformly layer of CNT, we used a spray gun on a hot plate by a simplified method. In the result, we fabricated a disperse SWCNT/Nafion composite uniformly.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2007.12a
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• pp.200-201
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• 2007

The present study was conducted in three fields at Namhae to examine the removal efficiency of organic free, heavy metal immobilized sediment on Cochlodinium polykrikoidesand and on sea water quality. The present study results concluded that removal efficiency was depends on the initial number of red tide cells. There was no drastic change in the sea water quality after sediment spray. For the comparison of effectiveness of betonite, zeolite and lime were mixed with sediment did not show any marked difference in removal. Finally, the present study evaluated 50g/$m^{2}$ sediment is sufficient to remove 100% cells density, even though various environmental factors are interfering the mechanism.

• Journal of ILASS-Korea
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• v.18 no.3
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• pp.146-154
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• 2013

The flow of a liquid film on spin coating is investigated in the case that the fixed volume of a liquid is placed on the center of a stationary disk. Thin film equations that are well approximated when the characteristic length in the vertical direction is much smaller than that in the radial direction (${\varepsilon}{\ll}1$) and have already been proposed in the work of T.-S. Kim & M.-U. Kim (2009), are used. The differential equation that governs the free surface of a liquid when ${\varepsilon}{\ll}1$ and ${\varepsilon}Re{\ll}1$ is also derived. The basic flow is analyzed using the thin film equations and their results are compared to the results of Navier-Stokes equations.