• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.495-497
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• 2017

열가소성 탄성중합체 바인더를 사용한 열가소성 추진제는 열경화성 추진제와 비교하여 중간 정도의 성능과 기계적 특성을 나타내지만 원재료 비용이 저렴하고, 제조 공정이 단순하며, 취급 공정이 안정적인 장점으로 인해 다양한 분야에서 폭 넓게 사용될 것이라 예측된다. 다양한 분야에서 열가소성 고체 추진제의 활용을 위해 주 원재료인 산화제, 금속연료 및 첨가제의 함량에 따른 특성 변화를 연구하여 향후 예상되는 열가소성 추진제의 수요에 대응하고자 한다.

• Journal of Microbiology
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• 제33권4호
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• pp.302-306
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• 1995

E. coli was tested for their ability to uptake cadmium intracellularly, and the effect of zinc and calcium on cadmium toxicity to E. coli was observed. In addition, the effect of zinc and calcium on the uptake of cadimium was also studied. This study showed that living E. coli cells took up more cadmium than the dead cells. E. coli in the log phase uptake cadimiumm more actively than E. coli in the stationary phase. These results suggested that there may be metabolic reactions or compounds which encourage the uptake of cadimium. This study also showed that cadimium was sequestered by cell components of which molecular weight is about 30,000. Adding of zinc and calcium chloride reduced cadmium toxicity in E. coli and encouraged intracellular uptake by E coli. However adding of heavy metal solutions helped the microorganisms to adsorb more cadmium. Extremely high or low concentrations of zinc, however, did not affect cell viability.

• 한국표면공학회지
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• 제53권5호
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• pp.207-212
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• 2020

Silver is an inexpensive precious metal and is used in various jewelry in Asia. Although silver has high potential, it has corrosion resistance that is vulnerable to boiling sulfuric acid and nitric acid. So, silver research is needed to prevent the corrosion with environment. But silver corrosion is not studied. sulfuric acid make the uniform corrosion and chloride ion make the pitting corrosion. ICCP inhibits the corrosion because it offset electrons. This study used a potential from - 4 V to 4 V to check the effect of potential. Corrosion rate is lowet at -1 V.

• 한국표면공학회지
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• 제47권5호
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• pp.269-274
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• 2014

Electroless plating process as a solution deposition method is a viable means of preparing conductive metal films on non-conducting substrates through chemical reactions. In the present study, the preparation and properties of electroless Ni-plating on flexible silicone rubber are described. The process has been performed using a conventional Ni(P) chemical bath. Additives and complexing agents such as ammonium chloride and glycine were added and the reaction pH was controlled by NaOH aqueous solution. Ni deposition rate and crystallinity have been found to vary with pH and temperature of the plating bath. It was shown that Ni-films having the high crystallinity, enhanced adhesion and optimum electric conductivity were formed uniformly on silicone rubber substrates under pH 7 at $70^{\circ}C$. The conductive Ni-plated silicone rubber showed a high electromagnetic interference shielding effect in the 400 MHz-1 GHz range.

• 한국식품영양과학회지
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• 제19권3호
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• pp.224-228
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• 1990

Cabbage contained high peroxidase activity among tested plant sources. The cabbage peroxi-dase can replace horseradish peroxidase to assay glucose with glucose oxidase. The amount of glucose can be determined quantitatively by glucose oxidase-cabbage peroxidase. The opti-mum pH and temperature for enzymatic glucose determination by glucose oxidase-cabbage peroxidase were 6.0 and 35-45$^{\circ}C$ respectively. The glucose assay was inhibited by addition of various metal salts such as mercuric chloride lead acetate silver nitrate ammonium molyb-date sodium tunstate and cupric sulfate. The relationship between absorbance and amount of glucose was linear up to 8.33 mM glucose in the assay mixture under the assay conditions.

• Bulletin of the Korean Chemical Society
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• 제15권2호
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• pp.145-150
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• 1994

The low temperature luminescence and excitation, room-temperature UV-visible and infrared spectra of [Cr(${\pm})chxn_3]Cl_3$ (chxn=trans-1,2-cyclohexanediamine) have been measured. It is found that the zero-phonon line in the excitation spectrum splits into two components by $47\;cm^{-1}$. The eight electronic transitions due to spin-allowed and spin-forbidden are assigned. As expected, nitrogen atoms of chxn ligand have strong ${\sigma}-donor $properties toward chromium(Ⅲ). The positions and splittings of sharp-line transitions are analyzed as a function of the Cartesian bite (${\alpha}$) and twist (${\beta}$) angles to predict the metal-ligand geometry.

• Bulletin of the Korean Chemical Society
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• 제14권6호
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• pp.708-712
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• 1993

The Polymerization of p-chlorophenyl propargyl ether (CPE) was carried out using various transition metal catalysts. The catalytic activity of $MoCl_{5}$-based catalysts was greater than that of $WCl_6$-based catalysts. $MoCl_5$ alone and $MoCl_{5}$-cocatalyst systems polymerized CPE very effectively to give a high yield of poly(CPE). In most cases, the polymer yield was quantitative and the average molecular weight $({\bar{M}}n)$ was in the range of 9,000 and 17,000. The NMR, IR, UV-visible spectra indicated that the present poly(CPE) has a linear conjugated polyene structure having p-chlorophenyl oxymethylene substituent. The poly(CPE) was mostly dark-brown colored powder and was completely soluble in various organic solvents such as chloroform, methylene chloride, THF, chlorobenzene, etc. The X-ray diffraction analysis indicated that the present poly(CPE) is amorphous.

• Bulletin of the Korean Chemical Society
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• 제22권4호
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• pp.405-408
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• 2001

New lipophilic triesters of calix[4]arene and calix[4]quinone are investigated as sodium ion-selective ionophores in poly(vinyl chloride) membrane electrodes. For an ion selective electrode based on calix[4]arene triester I, the linear response is 1 ${\times}$10-3.5 to 1 ${\times}$ 10-1 M of Na+ concentrations. The selectivity coefficients for sodium ion over alkali metal and ammonium ions are determined. The detection limit (logaNa+ = -4.50) and the selectivity coefficient (logKNa+,K+pot = -1.86) are obtained for polymeric membrane electrode containing calix[4]arene triester I.

• 한국환경과학회지
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• 제28권1호
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• pp.99-106
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• 2019

Arsenic is among the heavy metals commonly found in aqueous environments. Iron oxide is known as an efficient adsorbent for the arsenic. A new synthetic method was applied to provide iron oxide giving a large specific surface area. The mixing method affects the formation of iron oxide. Ultrasonic waves assisted the formation of very fine iron oxide in an organic phase. The synthesized iron oxide is amorphous type with a high surface area of more than $181.3m^2/g$. Sorption capacity of the synthesized adsorbent was relatively very high for arsenic and varied depending on the oxidation state of arsenic: a higher capacity was obtained with As(V). Lower solution pH provided a higher sorption capacity for As(V). The competitive effect of co-exist anions such as chloride, nitrate, and sulfate was minimal in sorption capacity of the iron oxide for arsenic.

• Nuclear Engineering and Technology
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• 제51권7호
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• pp.1866-1870
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• 2019

Residual salt separation is an essential step in pyroprocessing because its reaction products, as prepared by electrochemical unit processes, contain frozen residual electrolyte species, which are generally composed of alkali-metal chloride salts (e.g., LiCl, KCl). In this study, a simple technique that utilizes high-temperature gas flux as a driving force to melt and push out the residual salt in the reaction products was developed. This technique is simple as it only requires the use of a heating gun in combination with a gas injection system. Consequently, $LiNO_3-ZrO_2$ and $LiCl-ZrO_2$ mixtures were successfully separated by the high-temperature gas injection (separation efficiency > 93%), thereby demonstrating the viability of this simple technique for residual salt separation.