• Korean Journal of Materials Research
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• v.22 no.2
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• pp.78-81
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• 2012

$Y_2O_3$ nanomaterials have been widely used in transparent ceramics and luminescent devices. Recently, many studies have focused on controlling the size and morphology of $Y_2O_3$ in order to obtain better material performance. $Y_2O_3$ powders were prepared under a modified solvothermal condition involving precipitation from metal nitrates with aqueous ammonium hydroxide. The powders were obtained at temperatures at $250^{\circ}C$ after a 6h process. The properties of the $Y_2O_3$ powders were studied as a function of the solvent ratio. The synthesis of $Y_2O_3$ crystalline particles is possible under a modified solvothermal condition in a water/ethylene glycol solution. Solvothermal processing condition parameters including the pH, reaction temperature and solvent ratio, have significant effects on the formation, phase component, morphology and particle size of yttria powders. Ethylene glycol is a versatile, widely used, inexpensive, and safe capping organic molecule for uniform nanoparticles besides as a solvent. The characterization of the synthesized Y2O3 powders were studied by XRD, SEM (FE-SEM) and TG/DSC. An X-ray diffraction analysis of the synthesized powders indicated the formation of the $Y_2O_3$ cubic structure upon calcination. The average crystalline sizes and distribution of the synthesized $Y_2O_3$ powders was less than 2 um and broad, respectively. The synthesized particles were spherical and hexagonal in shape. The morphology of the synthesized powders changed with the water and ethylene glycol ratio. The average size and shape of the synthesized particles could be controlled by adjusting the solvent ratio.

• Korean Chemical Engineering Research
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• v.58 no.4
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• pp.635-641
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• 2020

In this study, phase equilibria and formation behaviors of methane hydrate containing mono-ethylene glycol (MEG) and salts (sodium chloride, NaCl; sodium bromide, NaBr; sodium iodide, NaI) are investigated. Equilibrium conditions of methane hydrate containing MEG and salts are measured in a temperature range 272~283 K and a pressure range 3.5~11 MPa. Hydrate inhibition performance in the presence of additives can be summarized as follows: methane hydrate containing (5 wt% NaCl + 10 wt% MEG) > (5 wt% NaBr + 10 wt% MEG) > (5 wt% NaI + 10 wt% MEG). Formation behaviors of methane hydrate with MEG and salts are investigated for analyzing the induction time, gas consumption amount and growth rate of methane hydrates. There are no significant changes in the induction time during methane hydrate formation, but the addition of MEG and salts solution during hydrate formation can affect the gas consumption amount and growth rate.

• Korean Journal of Veterinary Research
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• v.31 no.4
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• pp.523-527
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• 1991

The effects of ethylene glycol, DMSO and glycerol as cryoprotectants and the effect of concentrations(0, 0.25, 0.5 and 1.0M) of sucrose in the diluent on the viability of the aggregated morulae frozen rapidly in liquid nitrogen$(LN_2)$ vapour were examined. The morulae were produced by aggregation of ICR and CBA mice embryos at 8-cell stage. Before freezing the embryos were equilibrated in 1.5M cryoprotectants+0.25M sucrose in oae-step or in 3.0M cryoprotectants+0.25M sucrose in two-steps. The embryos were pipetted into the freezing medium fraction of 0.25ml plastic straws. The straws were frozeu by directly transfer into $LN_2$ vapour(about lcm above $LN_2$) for 2 minutes, and then plunged into $LN_2$. After thawing the cryoprotectants were diluted with 0, 0.25, 0.5 or 1.0M sucrose solution. The post-thawed in vitro viability of the aggregated embryos was significantly dependent on the type and concentration of cryoprotectants in the freezing medium and also on the concentration of sucrose in the diluent. When the aggregated embryos were equilibrated in 1.5M cryoprotectants +0.25M sucrose in one-step and diluted with 0.5M sucrose after thawing, the survival rate of the embryo5 was significantly(p<0.05) higher in DMSO(62.5%) or ethylene glycol(52.2%) than in glycerol(33.3 %). In the case that the concentration of the cryoprotectants was raised to 3.0M in two-steps, thc higher survival rate of the embryos was obtained in ethylene glycol or glycerol than in DMSO followed by diluting them with 0.5 or 1.0M sucrose after thawing(p<0.01).

• Korean Journal of Materials Research
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• v.11 no.1
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• pp.48-54
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• 2001

The effects of additives in the HCI etching solution on etching behaviors of aluminum foil as dielectric film for electrolytic capacitors were investigated. The etch pits formed in 1M hydrochloric acid containing ethylene glycol as an additive contain more fine and homogeneous etch tunnels compared to those in 1 M hydrochloric acid only, which led to the increase in the effective internal surface area of aluminum foil. After anodizing of aluminum foil etched in etching solutions, the LCR meter results have shown that the capacitance of dielectric film etched in hydrochloric acid with ethylene glycol was increased remarkably compared to that etched in hydrochloric acid only.

• Journal of Animal Science and Technology
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• v.48 no.6
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• pp.797-804
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• 2006

The present study was undertaken to investigate the post-thawed survivability of bovine embryo depending on different dose of ethylene glycol and sucrose. Ovaries were collected at local slaughterhouse and the cumulus-oocyte-complexes aspirated from ovaries were in vitro matured, fertilized and cultured at 39°C in an atmosphere of 5% CO2 incubator. For conventional slow-freezing, d 7 or 8 expanded blastocysts were collected. Embryos were equilibrated in 1.5 M and 1.8 M ethylene glycol(EG) with 0.1 M and 0.3 M sucrose in Dulbecco's phosphate-buffered saline(D-PBS) supplemented with 0.5% bovine serum albumin. Embryos were then loaded individually into 0.25ml-straw and placed directly into cooling chamber of programmable freezer precooled to 󰠏7°C, after 2 min, the straw was seeded, maintained at 󰠏7°C for 8 min, and then cooled to 󰠏35°C at 0.3°C/min, plunged and stored in liquid nitrogen for at least 3 days. For thawing, the straw containing embryos were warmed in air for 10 sec and exposed to 37°C water for 20 sec. Straws were then removed from 37°C water. Rates of blastocyst survive and hatching were evaluated at 24 to 72 h post-warming. No difference of the survivability was shown between 1.5 M and 1.8 M EG (71 and 70%, respectively). Addition of 0.1 M sucrose to 1.5 M and 1.8 M ethylene glycol in the freezing solution did not differ significantly embryo survival (74 and 77%, respectively), whereas survival rates was higher(89%) in freezing solution contained 0.3M sucrose to 1.8M EG compared with 0.3M sucrose to 1.5M EG group(71%). However, there was no difference in the overall total cell number between the two groups (122±1.8 vs 131±1.4, respectively). In conclusion, the results suggest that 0.3 M sucrose in 1.8 M EG may be optimal condition for freezing and thawing methods with in vitro produced embryos and may be applied to on-farm conditions for embryo transfer.

• Clinical and Experimental Reproductive Medicine
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• v.25 no.1
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• pp.87-92
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• 1998

This study was carried out to investigate in vitro/in vivo development of vitrified mouse oocytes. Mouse oocytes were vitrified using EFS30, 35 and 40 (30, 35 and 40% ethylene glycol, 18% ficoll and 0.5 M sucrose in M2 medium). After being exposed or vitrified-thawed, oocytes of normal morphology were inseminated in vitro by $1-2\times10^6/ml$ of epididymal sperm. The rates of fertilization, in vitro/in vivo development and cell number (inner cell mass and tropectoderm cell) of blastocysts in each treatment group were examined. The results obtained in these experiments were summarized as follows: The cleavage rates were obtained in EFS35 containing 35% ethylene glycol higher than in EFS30 and EFS40. The development rate of vitrified-thawed oocytes to two-cell stage after in vitro fertilization (51.1%) was significantly different compared to that of exposed to vitrification solution without cooling (60.0%) and control (68.2%) (p<0.05). However, there were no differences in the blastocyst formation from the cleaved embryos among groups (75.0, 73.3 and 80.0%). Also, the mean number of cells per blastocysts of vitrified group $(92.5{\pm}2.9)$ was similar to that of the exposed $(98.5{\pm}5.3)$ and control $(100.9{\pm}4.8)$. In vivo development of the blastocysts derived from vitrified-thawed oocytes resulted in fetal development (50.7%) and implantation rates (80.0%) which are very similar to those of control (58.2, 78.2%). These results suggest that mouse oocytes could be cryopreserved using vitrification solution (EFS35) based on ethylene glycol.

• Macromolecular Research
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• v.17 no.10
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• pp.729-733
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• 2009

Solution casting films of sulfonated poly[styrene-b-(ethylene-r-butylene)-b-styrene] copolymer (sSEBS)-based composite membranes that contained different amounts of organic, nanorod-shaped polyrotaxane were annealed at various temperatures for 1 h. The films' properties were characterized with respect to their use as polymer electrolyte membranes in direct methanol fuel cells (DMFCs). Different aspect ratios of polyrotaxane were prepared using the inclusion-complex reaction between $\alpha$-cyclodextrin and poly(ethylene glycol). The presence of the organic polyrotaxane inside the membrane changed the morphology during the membrane preparation and reduced the transport of methanol. The conductivity and methanol permeability of the composite membranes decreased with increasing polyrotaxane content, while the annealing temperature increased. All of the sSEBS-based, polyrotaxane composite membranes annealed at $140^{\circ}C$ showed a higher selectivity parameter, suggesting their potential usage for DMFCs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.123-126
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• 2003

The electrophoretic deposition method using the suspension solution with additives under the electric potential was applied for the fabrication of YBCO superconductor wire. This method was able to simplify the fabrication facilities, and produce an uniform and dense thick film. To improve the critical current density of deposited films, the additive PEGs(Poly Ethylene Glycole) with the molecular weight of 600, 1000 and 3400, were used as chemical binders for the suspension solution. The organic additive PEG showed better effects to the properties of YBCO superconductor wire. The PEG improved the adhesion between superconductor particles and suppressed the crack on the surface, which enhanced the surface uniformity and density of YBCO deposited film. It was found that acetone suspension solution showed better deposition properties than the others. The samples fabricated in the solution with the additive, 8 vol.% of 1% PEG(1000), showed the highest critical current density measured as $2300{\sim}2400\;Acm^2$ at 77 K, 0 T.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.132-137
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• 2006

Supercooled type ice slurry system is hard to keep a proper supercooling degree when solution becomes supercooling state. This is the reason of the ice blockage in pipe or cooling part due to an unstable cooling state. In this study, a cooling experiment was performed to pressurized solution in a stationary state. The behaviors during the supercooled aqueous solution were investigated at fixed flow rate of brine and aqueous solution of ethylene glycol 7 mass%. Also the effect to the freezing point of supercooled aqueous solution was investigated to the different pressure 101, 202, 303, and 404 kPa. At results, the pressure of the aqueous solution in the cylinder increased the supercooling degree increased and dissolution of supercooled point decreased.

• International Journal of Air-Conditioning and Refrigeration
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• v.17 no.1
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• pp.25-31
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• 2009

Supercooled type ice storage system with aqueous solution (or water) may have trouble with non-uniform release of supercooling even though it contributes to the simplicity of system and ecological improvement. The non-uniform release increases the instability of the system because it may cause an ice blockage in pipe or cooling part. In order to suppress the release of the supercooling, a cooling experiment was tried to an ethylene glycol(EG) 3 mass% solution corresponding with pressurization. Also, the frequency ratio of the release of the supercooling was measured to the pressurization from 101 to 505 kPa. At results, the frequency ratio of supercooling release tends to decrease as the pressure of the aqueous solution increased in each cooling rate. Moreover, it tends to decrease as the cooling rate of the solution decreased in each pressure.