Won Keun Son - Academia.edu (original) (raw)
Papers by Won Keun Son
Journal of Veterinary Medical Science, 2011
The purpose of the study was to compare two different electroretinography (ERG) instruments used ... more The purpose of the study was to compare two different electroretinography (ERG) instruments used on the same animal in a laboratory setting. Retinal function in both eyes of 12 healthy miniature schnauzers was evaluated under general anesthesia. Scotopic and photopic ERGs were recorded by the HMsERG and the RETIport using the Dog Standard Protocol recommended by the European College of Veterinary Ophthalmologists (ECVO). The waveforms of the ERGs obtained by the two ERG units were similar to those described in previous studies. The 90% reference ranges using the multiple of medians (MoM) showed that the changes in ERG parameters obtained by the HMsERG unit were very similar to those of the RETIport for most ERG responses, except for a few. The results demonstrate that the two ERG systems are comparable for evaluating retinal function in dogs. Further, the results also show that it is necessary to establish ERG system-specific limits of normality in each laboratory or clinic in order to obtain a correct diagnosis, for example by using a graphical representation of the 90% reference range.
2006 IEEE 8th International Conference on Properties and applications of Dielectric Materials, 2006
Lithium titanium oxide as anode material for energy storage prepared by novel synthesis method. L... more Lithium titanium oxide as anode material for energy storage prepared by novel synthesis method. Li4Ti5O12 based spinel-framework structures are of great interest material for lithium-ion batteries. We describe here Li4Ti5O12 a zero-strain insertion material was prepared by novel sol-gel method and by high energy ball milling (HEBM) of precursor to from nanocrystalline phases. According to the X-ray diffraction and scanning electron microscopy analysis, uniformly distributed Li4Ti5O12 particles with grain sizes of 100 nm were synthesized. Lithium cells, consisting of Li4Ti5O12 anode and lithium cathode showed the 173 mAh/g in the range of 1.0~3.0 V. Furthermore, the crystalline structure of Li4Ti5O 12 didn't transform during the lithium intercalation and deintercalation process
Journal of Power Sources, 2022
Journal of electrical engineering and information science, 1999
In this work, we measured the ability of adsorption and distribution coefficient of metallic ions... more In this work, we measured the ability of adsorption and distribution coefficient of metallic ions. When SPEES was cured for 48 hours at 200℃ and 250℃, ion exchange capacity was reduced to 37.87% and 56.88% of initial value and lost completely within 30 hours at 300℃. For SPEES in organic solvent system, as the solvent had higher polarity, ion exchange capacity increased, but distribution coefficient decreased at the same time. Ion exchange capacity was 5.93 meq/g, similar to initial value, after 25 time repeated adsorption and desorption, and it shows that functional group has chemical resistance to the oxidation catalysis reaction of metal ion. The amount of selective adsorption of metallic ions to SPEES ion mixed metallic ions solution was the order of Ba(Ⅱ)>Mg(Ⅱ)>K(I)>Na(Ⅰ).
KIEE International Transactions on Electrophysics and Applications, 2005
Journal of electrical engineering and information science, 1999
we determinated bonding constants for alkali metal cation (Li, Na, K) of the ion exchange resin o... more we determinated bonding constants for alkali metal cation (Li, Na, K) of the ion exchange resin of sulfonated poly(ether ether sulfone)(SPEES) in tetrahydrofurane(THF) and dioxane. As the polarity of a solvent increased and the reaction temperature decreased, the bonding constant became large. As the radii of metallic ion increased, the binding constant also increased in the order of Li(Ⅰ)<Na(Ⅰ)<K(Ⅰ). In the bonding reaction between SPEES ion exchanger and alkali picrate metal, the enthalpy of reaction ranged from -3.473 ~ -4.780 kcal/mol, while entropy ranged from 1.608~4.542 cal/Kㆍmol. Therefore it was spontaneous reaction due to the negative value of Gibb's free energy. When SPEES ion exchanger and alkali metal ion bind each other, they have good ion exchange capacity because of increasing the stability of the system.
RSC Advances, 2019
A crosslinked hydrophilic carbon electrode with better desalination performance can easily be pro... more A crosslinked hydrophilic carbon electrode with better desalination performance can easily be produced using room-temperature, quick electron-beam irradiation.
Korean Chemical Engineering Research, 2011
Capacitive deionization(CDI) is an ion removal technology that employs the basic electrochemical ... more Capacitive deionization(CDI) is an ion removal technology that employs the basic electrochemical principle of absorbing ions in high surface area electrode. CDI technology reduce power consumption because it operates at lower electrode potential(about 1~2 V). Also, it is an environmentally friendly technology because no acid, base, or salts are required to generate the surface. In this study, we searched the patents and papers to investigate the trend of CDI technologies. Database was collected from WIPS and Scopus site and was investigated according to electrode, module and application technology of CDI. The technology trend of CDI was analyzed based on patent application year, countries, main applications and technologies.
Journal of the Korean Electrochemical Society, 2006
Separation and Purification Technology, 2016
This study aims to evaluate the effect of LMO (lithium manganese oxide) and enhanced BEDI (bipola... more This study aims to evaluate the effect of LMO (lithium manganese oxide) and enhanced BEDI (bipolar membrane electro-dialysis deionization) on the lithium ion desorption process for the recovery of lithium ions. The factors that influence lithium ion recovery are evaluated in reference to the pH, voltage, flow rates, and number of bipolar membrane sheets to present the optimal conditions. The research findings show that in the desorption of LMO lithium ions, the lower the pH, the higher the desorption rates. When the voltage was 6.5 V per sheet, the desorption rates were approximately 70%, and when flow rates were 0.44 mL/cm 2 •min, the desorption was approximately 30 minutes faster than that at other flow rates. When the number of bipolar membrane sheets was 4, it was possible to control 4 the pH to under 4, a level at which lithium ions adsorbed onto LMO might affect the desorption phenomenon. For a combination of the conditions above, the desorption efficiency of lithium ions was approximately 70%, and the recovery time was reduced by approximately 180 minutes compared to when a chemical process was used for lithium ion desorption.
Korean Chemical Engineering Research, 2011
Polymer, 2004
The effects of solution properties and polyelectrolyte on the electrospinning of poly(ethylene ox... more The effects of solution properties and polyelectrolyte on the electrospinning of poly(ethylene oxide) (PEO) solutions were investigated. Ultrafine PEO fibers without beads were electrospun from 3, 4, 7 and 7 wt% PEO solutions in chloroform, ethanol, (dimethylformamide) DMF and water, respectively. At these concentrations, the values of ½hC were ,10 for all solutions. The average diameters of PEO fibers were ranged from 0.36 to 1.96 mm. The higher the dielectric constant of solvent was, the thinner PEO fiber was. The average diameters of electrospun PEO fibers from PEO/water solutions were decreased and their distributions were narrowed by adding 0.1 wt% poly(allylamine hydrochloride) (PAH) and poly(acrylic acid sodium salt) (PAA) due to the increased charge density in solutions. The addition of PAH and PAA lowered the minimum concentration for electrospinning of a PEO/water solution to 6 wt%.
Superconductor Science and Technology, 2006
YBa2Cu3O7−δ superconducting nanofibres were successfully fabricated via the electrospinning metho... more YBa2Cu3O7−δ superconducting nanofibres were successfully fabricated via the electrospinning method in combination with the sol–gel process. The solution was prepared by the sol–gel process with a homogeneous aqueous PVA solution containing Y, Ba, and Cu acetates. The viscosity of the precursor sol for electrospinning was controlled by the evaporation of solvent and a condensation reaction. The electrospun nanofibres were pyrolysed
Polymer Degradation and Stability, 2004
Porous ultra-fine fibres were prepared via selective thermal degradation of electrospun polyether... more Porous ultra-fine fibres were prepared via selective thermal degradation of electrospun polyetherimide/poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PEI/PHBV) fibres. Electrospun PEI/PHBV fibres had a relatively broad size distribution in the range of 2.6–15.1μm. PEI and PHBV were partially miscible and phase separation proceeded rapidly during the electrospinning process. Most of the PHBV in PEI/PHBV fibres was degraded at 210°C within 90min, while PEI remained undegraded.
Nanotechnology, 2005
... A solgel precursor (titanium isopropoxide) was mixed with a PVP solution in ethanol. After t... more ... A solgel precursor (titanium isopropoxide) was mixed with a PVP solution in ethanol. After the solution had been electrospun into a thin jet, the titanium isopropoxide immediately started to hydrolyse by reacting with the moisture in the surrounding air to generate a continuous ...
Materials Letters, 2005
Electrospinning of ultrafine polymer fibers has been drawing great attention due to their various... more Electrospinning of ultrafine polymer fibers has been drawing great attention due to their various applications in separation filters, wound dressing materials, tissue scaffolds, sensors, etc. [1], [2], [3], [4], [5] and [6]. It is obviously desirable to reduce the diameter of ultrafine fibers as ...
Macromolecular Rapid Communications, 2004
Journal of Veterinary Medical Science, 2011
The purpose of the study was to compare two different electroretinography (ERG) instruments used ... more The purpose of the study was to compare two different electroretinography (ERG) instruments used on the same animal in a laboratory setting. Retinal function in both eyes of 12 healthy miniature schnauzers was evaluated under general anesthesia. Scotopic and photopic ERGs were recorded by the HMsERG and the RETIport using the Dog Standard Protocol recommended by the European College of Veterinary Ophthalmologists (ECVO). The waveforms of the ERGs obtained by the two ERG units were similar to those described in previous studies. The 90% reference ranges using the multiple of medians (MoM) showed that the changes in ERG parameters obtained by the HMsERG unit were very similar to those of the RETIport for most ERG responses, except for a few. The results demonstrate that the two ERG systems are comparable for evaluating retinal function in dogs. Further, the results also show that it is necessary to establish ERG system-specific limits of normality in each laboratory or clinic in order to obtain a correct diagnosis, for example by using a graphical representation of the 90% reference range.
2006 IEEE 8th International Conference on Properties and applications of Dielectric Materials, 2006
Lithium titanium oxide as anode material for energy storage prepared by novel synthesis method. L... more Lithium titanium oxide as anode material for energy storage prepared by novel synthesis method. Li4Ti5O12 based spinel-framework structures are of great interest material for lithium-ion batteries. We describe here Li4Ti5O12 a zero-strain insertion material was prepared by novel sol-gel method and by high energy ball milling (HEBM) of precursor to from nanocrystalline phases. According to the X-ray diffraction and scanning electron microscopy analysis, uniformly distributed Li4Ti5O12 particles with grain sizes of 100 nm were synthesized. Lithium cells, consisting of Li4Ti5O12 anode and lithium cathode showed the 173 mAh/g in the range of 1.0~3.0 V. Furthermore, the crystalline structure of Li4Ti5O 12 didn't transform during the lithium intercalation and deintercalation process
Journal of Power Sources, 2022
Journal of electrical engineering and information science, 1999
In this work, we measured the ability of adsorption and distribution coefficient of metallic ions... more In this work, we measured the ability of adsorption and distribution coefficient of metallic ions. When SPEES was cured for 48 hours at 200℃ and 250℃, ion exchange capacity was reduced to 37.87% and 56.88% of initial value and lost completely within 30 hours at 300℃. For SPEES in organic solvent system, as the solvent had higher polarity, ion exchange capacity increased, but distribution coefficient decreased at the same time. Ion exchange capacity was 5.93 meq/g, similar to initial value, after 25 time repeated adsorption and desorption, and it shows that functional group has chemical resistance to the oxidation catalysis reaction of metal ion. The amount of selective adsorption of metallic ions to SPEES ion mixed metallic ions solution was the order of Ba(Ⅱ)>Mg(Ⅱ)>K(I)>Na(Ⅰ).
KIEE International Transactions on Electrophysics and Applications, 2005
Journal of electrical engineering and information science, 1999
we determinated bonding constants for alkali metal cation (Li, Na, K) of the ion exchange resin o... more we determinated bonding constants for alkali metal cation (Li, Na, K) of the ion exchange resin of sulfonated poly(ether ether sulfone)(SPEES) in tetrahydrofurane(THF) and dioxane. As the polarity of a solvent increased and the reaction temperature decreased, the bonding constant became large. As the radii of metallic ion increased, the binding constant also increased in the order of Li(Ⅰ)<Na(Ⅰ)<K(Ⅰ). In the bonding reaction between SPEES ion exchanger and alkali picrate metal, the enthalpy of reaction ranged from -3.473 ~ -4.780 kcal/mol, while entropy ranged from 1.608~4.542 cal/Kㆍmol. Therefore it was spontaneous reaction due to the negative value of Gibb's free energy. When SPEES ion exchanger and alkali metal ion bind each other, they have good ion exchange capacity because of increasing the stability of the system.
RSC Advances, 2019
A crosslinked hydrophilic carbon electrode with better desalination performance can easily be pro... more A crosslinked hydrophilic carbon electrode with better desalination performance can easily be produced using room-temperature, quick electron-beam irradiation.
Korean Chemical Engineering Research, 2011
Capacitive deionization(CDI) is an ion removal technology that employs the basic electrochemical ... more Capacitive deionization(CDI) is an ion removal technology that employs the basic electrochemical principle of absorbing ions in high surface area electrode. CDI technology reduce power consumption because it operates at lower electrode potential(about 1~2 V). Also, it is an environmentally friendly technology because no acid, base, or salts are required to generate the surface. In this study, we searched the patents and papers to investigate the trend of CDI technologies. Database was collected from WIPS and Scopus site and was investigated according to electrode, module and application technology of CDI. The technology trend of CDI was analyzed based on patent application year, countries, main applications and technologies.
Journal of the Korean Electrochemical Society, 2006
Separation and Purification Technology, 2016
This study aims to evaluate the effect of LMO (lithium manganese oxide) and enhanced BEDI (bipola... more This study aims to evaluate the effect of LMO (lithium manganese oxide) and enhanced BEDI (bipolar membrane electro-dialysis deionization) on the lithium ion desorption process for the recovery of lithium ions. The factors that influence lithium ion recovery are evaluated in reference to the pH, voltage, flow rates, and number of bipolar membrane sheets to present the optimal conditions. The research findings show that in the desorption of LMO lithium ions, the lower the pH, the higher the desorption rates. When the voltage was 6.5 V per sheet, the desorption rates were approximately 70%, and when flow rates were 0.44 mL/cm 2 •min, the desorption was approximately 30 minutes faster than that at other flow rates. When the number of bipolar membrane sheets was 4, it was possible to control 4 the pH to under 4, a level at which lithium ions adsorbed onto LMO might affect the desorption phenomenon. For a combination of the conditions above, the desorption efficiency of lithium ions was approximately 70%, and the recovery time was reduced by approximately 180 minutes compared to when a chemical process was used for lithium ion desorption.
Korean Chemical Engineering Research, 2011
Polymer, 2004
The effects of solution properties and polyelectrolyte on the electrospinning of poly(ethylene ox... more The effects of solution properties and polyelectrolyte on the electrospinning of poly(ethylene oxide) (PEO) solutions were investigated. Ultrafine PEO fibers without beads were electrospun from 3, 4, 7 and 7 wt% PEO solutions in chloroform, ethanol, (dimethylformamide) DMF and water, respectively. At these concentrations, the values of ½hC were ,10 for all solutions. The average diameters of PEO fibers were ranged from 0.36 to 1.96 mm. The higher the dielectric constant of solvent was, the thinner PEO fiber was. The average diameters of electrospun PEO fibers from PEO/water solutions were decreased and their distributions were narrowed by adding 0.1 wt% poly(allylamine hydrochloride) (PAH) and poly(acrylic acid sodium salt) (PAA) due to the increased charge density in solutions. The addition of PAH and PAA lowered the minimum concentration for electrospinning of a PEO/water solution to 6 wt%.
Superconductor Science and Technology, 2006
YBa2Cu3O7−δ superconducting nanofibres were successfully fabricated via the electrospinning metho... more YBa2Cu3O7−δ superconducting nanofibres were successfully fabricated via the electrospinning method in combination with the sol–gel process. The solution was prepared by the sol–gel process with a homogeneous aqueous PVA solution containing Y, Ba, and Cu acetates. The viscosity of the precursor sol for electrospinning was controlled by the evaporation of solvent and a condensation reaction. The electrospun nanofibres were pyrolysed
Polymer Degradation and Stability, 2004
Porous ultra-fine fibres were prepared via selective thermal degradation of electrospun polyether... more Porous ultra-fine fibres were prepared via selective thermal degradation of electrospun polyetherimide/poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PEI/PHBV) fibres. Electrospun PEI/PHBV fibres had a relatively broad size distribution in the range of 2.6–15.1μm. PEI and PHBV were partially miscible and phase separation proceeded rapidly during the electrospinning process. Most of the PHBV in PEI/PHBV fibres was degraded at 210°C within 90min, while PEI remained undegraded.
Nanotechnology, 2005
... A solgel precursor (titanium isopropoxide) was mixed with a PVP solution in ethanol. After t... more ... A solgel precursor (titanium isopropoxide) was mixed with a PVP solution in ethanol. After the solution had been electrospun into a thin jet, the titanium isopropoxide immediately started to hydrolyse by reacting with the moisture in the surrounding air to generate a continuous ...
Materials Letters, 2005
Electrospinning of ultrafine polymer fibers has been drawing great attention due to their various... more Electrospinning of ultrafine polymer fibers has been drawing great attention due to their various applications in separation filters, wound dressing materials, tissue scaffolds, sensors, etc. [1], [2], [3], [4], [5] and [6]. It is obviously desirable to reduce the diameter of ultrafine fibers as ...
Macromolecular Rapid Communications, 2004