• Journal of the Korean Ceramic Society
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• v.18 no.2
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• pp.91-98
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• 1981

Synthetic zeolite A was prerared from domestic Hadong kaolin with sodium hydroxide solution and their ion exchange isotherms of $K^+$, $NH^{4+}$, $Li^+$ and $Ag^+$ ion were presented. The optimum reaction conditions for synthetic zeolite A from calcinated kaolin were 2 fold excess of 2N sodium hydroxide solution, 10$0^{\circ}C$ and 8 hours. It was observed that before the crystallization of zeolite A the samples reacted with sodium hydroxide solution had rather higher ion exchange capacities than zeolite A. The $K^+$-$Na^+$ and $Ag^+$$Na^+$ ion exchange isotherms were signoidal. The initial selectivity series was in the order $Ag^+$$K^+$>$Na^+$>$NH_4$>$Li^+$. Between approximately 33 and 67% replacement of soium ions the selectivity series became $Na^>$ and above 67% became $Ag^+$>$K^+$. Evidence were also presented to demonstrate that 8 out of 12 sodium ions per pseudo unit cell were not easily replaceable by lithium ions and 4 out of 12 not easily replaceable by ammonium ions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.147-150
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• 1999

In the case of immobilizing of glucose oxidase in organic polymer using electrosynthesis, the glucose oxidase obstructs charge transfer and mass transport during the film growth. This may lead to short chained polymer and/or make charge-coupling weak between the glucose oxidase and the backbone of the polymer. That is mainly due to insulating property and net chain of the glucose oxidase. Since being the case, it is useless to increase in amount of glucose oxidase more than reasonable in the synthetic solution. We establish qualitatively that amount of immobilization can be improved by adding a little ethanol in the synthetic solution. As ethanol was added by 0.1 rnol dm" in the synthetic solution, Michaelis-Menten constants of the resulting enzyme electrode decreased from 30.7 mmol $dm^{-3}$ to about 2 mmol $dm^{-3}$. That suggests increase in affinity of the enzyme electrode for glucose and in amount of the immobilized enzyme.zyme.

• Journal of Veterinary Clinics
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• v.10 no.2
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• pp.227-235
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• 1993

The effectiveness of sodium carboxymethylcellulose(SCMC) and dextran 70 in the prevention of adhesion formation in abdominal cavity of rabbits following artificial injuries was elucidated and the effects -of these medicines on blood pictures were also examined. After abrasion treatment on jejunum in gonadotropins primed rabbits, 1, 2 and 3% of SCMC solutions, 6 and 10% dextran 70 solutions and a synthetic solution of 1% SCMC and loft dextran 70 in 0.9% saline solution were infused into the abdominal cavity. Four weeks later the abdominal cavities were reopened under general anesthesia. The synthetic solution showed the highest adhesion reduction rate(100%), while 1% SCMC, 6 and loft dextran solutions showed no significantly evident effect of adhesion prevention. The SCMC solutions showed better adhesion reduction effect than dextran 70 solutions. After infusion of these adhesion preventive medicines, the changes of total leucocytes, erythrocytes, lymphocytes, PCV, plasma fibrinogen and protein contents were examined. No remarkable difference in blood pictures was shown between the synthetic solution and the other medicines. Therefore, it can be suggested that the synthetic solution of 1% SCMC and 10% dextran 70 in 0.9% saline solution at dose of 5$m\ell$/kg of body weight is prominently effective in the prevention of postoperative adhesion formation and wolf be safe in animals and human.

• Journal of Environmental Science International
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• v.9 no.6
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• pp.517-522
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• 2000

Separation of strontium ion from synthetic seawater in the contained liquid membrane permeator with two micro-porous films was performed. The permeator consisted of a liquid membrane and two cells for aqueous solutions. The liquid membrane consisted of $D_2EHPA(di-2-ethylhexy1-phosphoric acid)$ and DCH18C6 (dicyclohexano-18-crown-6),diluted to 30 vol% with kerosine and was trapped between two micro-porous hydrophilic films. This liquid membrane separated two aqueous solutions, one of which was synthetic seawater and the other of which was the stripping solutions consisting of 1mol/L $H_2SO_4$ solution. The effects of various operating parameters on the extraction rate and equilibrium extraction ratio of strontium ion from synthetic seawater were experimentally examined. The addition of DCH18C6 to the $D_2EHPA$ solution caused synergy effect on the extraction of strontium ion. The permeator extracted strontium ion from synthetic seawater effectively with high membrane life time.

• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.6
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• pp.970-976
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• 1997

Synthetic leather added collagen protein was coagulated in DMF solution. With increasing collagen concentration, thickness of synthetic leather increased. In addition, water vapor permeability and water vapor absoption increased with increasing collagen protein concentration. But MIU and SMD value of surface properties decreased with increasing collagen protein concentration. As a result, synthetic leather added collagen protein showed comfort and dry touch.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.7
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• pp.621-626
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• 2002

In the case of immobilizing of glucose oxidase (GOx) in polypyrrole (PPy) conducting polymer using electrosynthesis, the GOx obstructs charge transfer and mass transport during the film growth. This may lead to short chained polymer and/or make charge-coupling weak between the GOx and the backbone of the PPy. That is mainly due to insulating property and net chain of the GOx. Since being the case, it is useless to increase in amount of GOx mere than reasonable in the synthetic solution. We improved the amount of immobilized GOx into the PPy by adding a little ethanol in the synthetic solution without any more amount of GOx in the solution. We electrochemically analyzed an improvement in the immobilizing event. For the glucose sensing, when ethanol was added by 0.1 mol $dm^{-3}$ in the synthetic solution, the Michaelis constant of the resulting enzyme electrode was about 32 mmol $dm^{-3}$ and maximum current was about $146\mu A$.

• Journal of Sensor Science and Technology
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• v.23 no.4
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• pp.266-271
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• 2014

Chemical sensors are used in various industrial facilities such high-risk and prevent the leakage of substances, important in life and environmental protection and the safe use of industry, used for management. In particular, high-temperature environments such as power generation equipment of the rotating part due to leakage generated by the various oil, power plants Shut Down, fire, work environment (exposure to various chemical solution and gas leak) and various water, air and soil pollution causes. Thus, over the long term through various channels such as crops and groundwater contamination caused by the slow, serious adverse effect on the ecosystem. In this paper, synthetic lube oil and high pressure hydraulic fluid leakage and immediately detect a new Printed Electronic implementation of technology-based film-type sensors, and its performance test. Thus, industrial accidents and environmental pollution and for early detection of problems, large accidents can be prevented. Experimental results of the synthetic lube oil and high pressure hydraulic fluid solution after the contact time depending on the experiment and the oil solution of the sensor material of the conductive porous PE resistance value by a chemical reaction could be confirmed that rapid increase. Also implemented in the film-type oil sensor electrical resistance change over time of the reaction rate and the synthetic lube oil is about 2 minutes or less, the high pressure hydraulic fluid is less than about 1 minute was. Therefore, more high-pressure hydraulic fluid such as a low volatility synthetic lube oils are the resistance change and the reaction rate was confirmed to be the slowest.

• Journal of Environmental Science International
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• v.20 no.10
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• pp.1337-1345
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• 2011

The removal performances of divalent heavy metal ions ($Pb^{2+}$, $Cu^{2+}$, $Cd^{2+}$, $Sr^{2+}$ and $Mn^{2+}$) were studied using the Na-P1 zeolite synthesized from Jeju scoria in the batch and continuous fixed column reactor. The uptakes of heavy metal ions by synthetic Na-P1 zeolite decreased in the order of $Pb^{2+}$ > $Cu2^{2+}$ > $Cd^{2+}$ > $Sr^{2+}$ > $Mn^{2+}$ based on the selectivity of each ion to ionic exchange site of Na-P1 zeolite for single and mixed solutions in batch or continuous fixed column reactor. For mixed solution, each heavy metal ion uptake was lower than that in single solution, and especially the uptake for $Mn^{2+}$ decreased greatly. In batch reactor, the uptakes of heavy metal ions by synthetic Na-P1 zeolite were described by Freundlich or Langmuir equation, but they followed the former better than the latter. In continuous fixed column reactor, the maximum ion exchange capacity obtained for each of heavy metal ions, was about 90----- of that in batch reactor. The uptakes of heavy metal ions by synthetic Na-P1 zeolite increased with the increase of initial heavy metal concentration and solution pH, and the decrease of the amount and particle size of synthetic zeolite.

• KSBB Journal
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• v.27 no.4
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• pp.215-221
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• 2012

Synthetic plastics are important in many branches of industry. Although synthetic plastics provide numerous benefits, they also cause a significant environmental pollution problem because of their non-readily-biodegradability. Biodegradation may provide solution to the problem, but not enough is known about the biodegradation mechanisms of synthetic plastics. This review has been written to provide an overview of the current state of synthetic plastics (polyethylene, polyurethane, nylon, polyvinyl alcohol) biodegradation. Several biodegradation mechanisms of a few selected synthetic plastics are also presented.

• Journal of Korean Society on Water Environment
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• v.22 no.4
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• pp.658-665
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• 2006

The removal characteristics of silver ion from waste photographic solution have been investigated by recovering silver electrochemically. Cyclic voltammetry for synthetic and actual wastewater which containing silver ion was investigated to understand its electrochemical behavior. For both synthetic and actual wastewater, the recovery of silver according to the electrowinning time was observed to be increased as the applied potential was raised. In addition, the applicable potential for the electrowinning of silver was found to be lower for synthetic wastewater compared with actual wastewater. As the temperature was increased, more silver was recovered for both wastewater, which indicated the electrowinning reaction was endothermic. The electrowinned silver was refined electrochemically to increase its purity and the variation of the purity of silver was examined according to the electrorefining potential.