• Journal of Life Science
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• v.19 no.8
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• pp.1033-1038
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• 2009

Maximal productions of gellan by Sphingomnas paucibilis NK2000 from 20 g/l glucose and 10 g/l soybean pomace were 7.46 g/l in a flask and 7.35 g/l in a 7 l bioreactor, when the initial pH of media was 6.8. Maximal production of gellan in a 7 l bioreactor under pH control by sodium hydroxide was 8.42 g/l, whereas that under control by potassium phosphate was 8.50 g/l. The optimal concentration of potassium phosphate in a medium for production of gellan by S. paucibilis NK2000 was found to be 5.0 g/l. Maximal production of gellan in a medium containing 5.0 g/l potassium phosphate without pH control was 8.93 g/l in a 7 l bioreactor. In this study, a simple process without pH control was developed to enhance the production of gellan, with optimized concentration of potassium phosphate in the medium.

• Journal of Sensor Science and Technology
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• v.4 no.3
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• pp.22-29
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• 1995

Lithium ionic solid electrolyte was synthesized at $60^{\circ}C$ in $N_{2}$ ambience by sol-gel method, using tetraethyl orthosilcate, lithium methoxide, zirconium n-propoxide, and tributyle phosphate as precursors. The prepared material was dried and crushed into powder, and it was pressed into disk type samples. These samples were sintered at $900^{\circ}C{\sim}1100^{\circ}C$ for 50 hours. The physical characteristics of the samples were investigated by TG/DTA, SEM, AES and XRD methods. $CO_{2}$ sensor based on lithium ionic solid electrolyte was fabricated and its operational characteristics were measured. The sensing characteristics of the sensor sintered at $1000^{\circ}C$ shows the variation of e.m.f. about $35{\sim}63\;mV/decade$ for the variation of $CO_{2}$ concentration at $200^{\circ}C{\sim}300^{\circ}C$ of operating temperature, and good linearity for $300{\sim}6000\;ppm$.

• Clean Technology
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• v.24 no.3
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• pp.157-165
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• 2018

In this study, the removal of $Si_3N_4$ particles from the surface of a silicon wafer was investigated by using supercritical carbon dioxide, the IPA co-solvent and cleaning additive chemicals. First, the solubility of several surfactants and binders in supercritical carbon dioxide solubility and particle dispersibility in the binders were evaluated in order to confirm their suitability for the supercritical cleaning process. Particle removal experiments were carried out with adjusting various process parameters and reaction conditions. The surfactants used in the experiment showed little particle removal effect, producing secondary contamination on the surface of wafers. On the other hand, 5 wt% (with respect to $scCO_2$) of the cleaning additive mixture of trimethyl phosphate, IPA, and trace HF resulted in 85% of particle removal efficiency after $scCO_2$ flowing for 4 minutes at $50^{\circ}C$, 2000 psi, and the flow rate of $15mL\;min^{-1}$.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.11b
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• pp.157-157
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• 2002

The toxicity of GX-12, a naked DNA vaccine developed by research team of Dong-A Pharmaceutical Company, Green Cross Company and Genexine for the treatment of HIV infection, was investigated in Sprague-Dawley rats. In single-dose intramuscular/oral acute toxicity studies, animals were treated 0, 250, 1000 or 4000 $\mu\textrm{g}$/kg/$m\ell$ in sodium phosphate buffer.(omitted)

• The Journal of the Korean dental association
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• v.47 no.9
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• pp.596-606
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• 2009

Aim : The ultimate goal of periodontal treatment is regeneration of periodontium that have been lost due to inflammatory periodontal disease. Recently, Silicon contained Coralline Hydroxyapatite and Beta Tricalcium Phosphate bone substitute have been introduced to achieve periodontal regeneration. The purpose of this study is to evaluate the effect of the Silicon contained Coralline Hydroxyapatite and Beta Tricalcium Phosphate(BoneMedik-$DM^{(R)}$, Meta Biomed Co., Ltd. Oksan, Korea) on periodontal intrabony defects. Methods and materials : Clinical effects of Silicon contained Coralline Hydroxyapatite and Beta Tricalcium Phosphate implantation in intrabony defects were evaluated 6 months after surgery in Sixty-one intrabony defects from Fourty-six patients with chronic periodontitis. Twenty-nine experimental defects in twenty-five patients received the Silicon contained Coralline Hydroxyapatite and Beta Tricalcium Phosphate(test group), while Thirty-Three defects in twenty-one patients were treated with flap procedure only( control group). Comparative observation were done for preoperative and postoperative differences between control and experimental clinical parameters,-clinical attachment 10ss(CAL), probing depth(PD), bone probing depth(BPD), gingi val recession. Results : Postoperative improvements in CAL, PD, BPD were observed in both test and control groups(P<0.0l). However, the improvements in CAL, PD, BPD of the test group were significantly greater than control group. Conclusion : Healing of the both groups were uneventful during experimental periods. Use of Silicon contained Coralline Hydroxyapatite and Beta Tricalcium Phosphate in a flap operation resulted in significantly greater improvements in CAL, PD, and BPD over flap operation alone. Silicon contained Coralline Hydroxyapatite and Beta Tricalcium Phosphate will be good bone substitute materials for treatment of intrabony defects.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.6
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• pp.1127-1137
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• 2000

Applications of lanthanum ion and crude rare earth chloride to the phosphate wastewater and fluorine wastewater, respectively, as treatment agents were studied. For the investigation of phosphate removal characteristics according to the amount of lanthanum ion, initial phosphate content was decreased by about 50% when molar ratio of [$La^{3+}$]:[$PO_4{^{3-}}-P$] was 0.25 and nearly all of phosphate was removed when the molar ratio of [$La^{3+}$]:[$PO_4{^{3-}}-P$] to be doubled. The removal of phosphate by $La^{3+}$ appeared to reach equilibrium state rapidly, and it was exothermic reaction since the removed amount of phosphate was diminished somewhat when the reaction temperature was increased. The zeta potential of combined particulate compound of lanthanum ion and phosphate was located for its isoelectric point at pH 5.5 and the turbidity of treated wastewater was found to vary according to the pH in a similar manner as the absolute value of zeta potential of the combined particulate compound did. For the treatment of fluorine wastewater by crude rare earth chloride, the remaining fluorine content after treatment decreased as the dosage of crude rare earth chloride increased. Whereas, the turbidity of treated wastewater and the amount of sludge generated were shown to increase as more crude rare earth chloride was added. The remaining fluorine content and the turbidity of treated wastewater were decreased and the amount of sludge generated was observed to increase according the increase of coagulant dosage under the condition of constant input of crude rare earth chloride.

• Proceedings of the Korean Fiber Society Conference
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• 2007.11a
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• pp.291-292
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• 2007

• Clinical and Experimental Reproductive Medicine
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• v.22 no.3
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• pp.301-307
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• 1995

소 체외수정란에 있어서 pentose phosphate pathway (PPP)를 연구하기 위해서, 한개의 체외수정란으로부터 glucose 6-phosphate dehydrogenase (G6PDH)의 활성을 효소증폭방법으로 측정하였다. Glucose 6-phosphate (G6P) 기질을 처리하지 않은 2, 4, 8세포기, 상실배 및 배반포기 수정란에서의 G6PDH 활성치는 각각 $25.5{\pm}3.3$, $27.8{\pm}3.4$, $40.9{\pm}6.2$, $34.9{\pm}3.6$ 및 $52.9{\pm}2.5{\times}10^{-8}mol/embryo/h$ 을 나타내었다. 즉, 8 세포기 이후 수정란들은 2 세포기나 4 세포기보다도 높은 효소활성치를 보여주었다 (P<0.01). 그리고 G6P 기질을 첨가한 2,4,8 세포기, 상실배기 및 배반포기 수정란의 G6PDH 활성치는 각각 $32.3{\pm}3.9$, $29.4{\pm}1.8$, $51.9{\pm}4.2$, $42.6{\pm}2.7$ 및 $52.9{\pm}2.5{\times}10^{-8}mol/embryo/h$ 로서 기질 무처리구와 마찬가지로 유의성이 인정되었다 (P<0.01). 전반적으로 수정란의 발달단계에 있어서 G6P 첨가한 수정란들에 G6PDH의 효소활성치가 기질을 처리하지 수정란들의 것보다도 높은 경향을 보였다. 한편, 소 체외수정란의 G6PDH 효소활성치와 발생능과의 관계를 알아보기 위하여, 4 세포기 수정란들을 효소활성치의 정량적 수준 (low, middle, high)에 따라 3 군으로 분류한 다음 $38.5^{\circ}C$, 5% $CO_2$에서 5일간 난구세포들과 공동배양을 실시하였다. 그 결과, G6PDH 효소활성치 차이에 따른 수정란들의 체외발달율에는 유의성이 인정되지 않았다. 본 실험의 결과를 종합하여 볼 때, 소 체외수정란에 있어서 PPP 대사는 8세포기 이후부터 활발히 이루어지고 있음을 알 수 있었다.

• Korean Journal of Food Science and Technology
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• v.19 no.4
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• pp.366-370
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• 1987

Rheological properties of gelatinized rice starch solutions (5%) were examined with a Brookifield viscometer. Gelatinized rice starch solutions showed pseudoplastic flow having yield stress, i.e., Binghamplastic flow behavior. The yield stress of gelatinized rice starch solutions was reduced by the phosphate. Phosphate increased the pseudoplasticity of gelatinized nonwaxy rice starch solutions. but decreased that of gelatinized waxy rice starch solution. The yield stress of gelatinized nonwaxy rice starch solutions held for one hour at $90^{\circ}C$ was slightly decreased, but that of waxy starch solution was reduced by 10-fold. Phosphate reduced the yield stress for both gelatinized nonwaxy and waxy rice starch solutions. Phosphate decreased the consistency index, but did not affect the flow behavior index of the gelatinized rice starch solutions.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.4
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• pp.311-320
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• 2006

Removal characteristics of $H^{14}CO_3$ ion from IRN-150 mixed resin contaminated with $^{14}C$ radionuclide and a gasification behavior of $^{14}C$ radionuclide to $^{14}CO_2$ were investigated. The stripping solutions used for the removal of $^{14}C$ from spent resin were $NaNO_3,\;Na_3PO_4,\;NH_4H_2PO_4,\;H_3PO_4$. The influence of stripping solution concentration on the desorption characteristics of inactive $HCO_3$ ion into stripping solution from IRN-150 mixed resin and the gasification of this ion to $CO_2$ was analyzed. The gasification behavior to $CO_2$ by using NaOH, $HNO_3$, HCl was also compared to that of phosphate solution. Real spent resin stored in Wolsung nuclear power plant was used to evaluate the gasification characteristics of $^{14}C$ radionuclide to $^{14}CO_2$. Gamma radionuclides such as $^{137}Cs,\;^{60}Co$ in residual striping solutions after desorption experiment were analyzed.