• 한국환경과학회지
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• 제10권5호
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• pp.381-386
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• 2001

The characteristics of precipitation separation and solvent extraction separation of magnesium from the waste bittern were studied experimentally In the result of precipitation separation, the size of magnesium hydroxide precipitated was not affected on pH, but decreased with increasing the precipitation temperature. The purity of magnesium oxide precipitated was increased with pH beyond pH 11. From the solvent extraction separation, the equilibrium extraction ratio of magnesium was increased with pH and temperature of extraction phase, the concentration of stripping phase, and with decreasing pH of stripping phase. The extractant of Aliquat 336 and Acid 810 mixture was more effective than that of DCH18C6 and $D_2EHPA$ mixture in the extraction separation of magnesium.

• Progress in Superconductivity
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• 제5권1호
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• pp.84-87
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• 2003

$YBa_2$$Cu_3$$O_{7-x}$ (YBCO) thin films were fabricated by MOD-TFA process via dip-coating method on LaAlO$_3$, (LAO) single crystalline substrates. In this study, we investigated effect of annealing temperature and solvent on the microstructure and texture of YBCO thin films. The precursor films were annealed at various temperature to improve surface morphologies and phase purities. It was shown that the films annealed at relatively lower and higher temperature exhibit low phase purity and crystallinity. The effect of various solvents on surface morphologies and second phase has been investigated.

• 자원리싸이클링
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• 제28권4호
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• pp.30-36
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• 2019

본 연구는 폐 리튬이온전지의 양극활물질인 LNO($Li_2NiO_2$) 공정부산물로부터 $CO_2$ 열반응 공정을 통하여 Li 분말을 회수하였다. Li 분말을 회수하는 공정은 $CO_2$ 주입량이 300 cc/min인 분위기에서 $600^{\circ}C$, 1 min 유지하여 $Li_2NiO_2$ 상을 $Li_2CO_3$상과 NiO상으로 상분리 시켰다. 이 후 회수한 시료:증류수 = 1:50 무게비로 수 침출 후 감압 여과를 통해 용액에서 $Li_2CO_3$, 여과지에서 NiO 분말을 회수하였다. Ni 순도를 높이기 위해 $H_2$ 분위기에서 3시간 유지하여 NiO에서 Ni로 환원하였다. 위와 같은 공정을 통해 회수한 탄산리튬 용액의 Li의 농도 2290 ppm, Li의 회수율은 92.74%를 달성하였고 Ni은 최종적으로 순도는 90.1%, 회수율 92.6%의 분말을 제조하였다.

• 핵의학기술
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• 제16권1호
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• pp.8-11
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• 2012

상용화된 자동합성장치는 사용되는 유기용매의 종류가 다르고 합성수율에 차이를 보인다. 따라서 본 연구에서는 자동합성장치에 따른 $^{18}F$-FDG의 방사선분해에 관한 방사화학적순도 변화를 비교하였다. Cyclotron (PETtrace, GE Healthcare)을 사용하여 $^{18}F$를 생산하고, 자동합성장치(FASTlab, Tracerlab MX, GE Healthcare)를 이용하여 FDG로 합성하였다. 방사화화적순도는 Radio-TLC Scanner (AR 2000, Bioscan), GC(Gas Chromatography, Agilent 7890A)를 사용하여 $^{18}F$-FDG에 함유되어 있는 에탄올의 양을 측정하였다. 고정상은 실리카겔로 도포된 유리판($1{\times}10cm$), 이동상은 아세토니트릴과 물 19:1 혼합액을 사용하고, 각각의 합성장치에서 고농도와 저농도의 $^{18}F$-FDG를 생산 후 2시간 간격으로 방사화학적순도를 측정하였다. 저농도 (약 2.59 GBq/mL 이하)에서 순도변화는 Tracerlab MX에서는 99.26%, 98.69%, 98.25%, 98.09%, FASTlab에서는 99.09%, 97.83, 96.89%, 96.62%를 얻었다. 고농도(약 3.7 GBq/mL 이상)에서 순도변화는 Tracerlab MX에서는 평균 99.54%, 96.08%, 93.77%, 92.54%, FASTlab의 경우 99.53%, 95.65%, 92.39%, 89.82%를 얻었다. 그리고 FASTlab에서 생산한 $^{18}F$-FDG의 GC에서는 에탄올이 검출되지 않았으며, Tracerlab MX에서는 100~300 ppm의 에탄올이 검출되었다. 이러한 결과를 비추어 봤을 때 방사선 보호제인 에탄올의 유무보다 방사능농도가 방사선분해에 더 큰 영향을 미치기 때문에 고농도의 $^{18}F$-FDG 생산 후 무균 생리식염수로 희석하여 농도를 낮춘 후 사용해야 한다.

• 한국분말재료학회지
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• 제13권1호
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• pp.46-51
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• 2006

Through the volume change of Sn in a low-temperature phase transformation, the Sn nanopowder with high, purity, was fabricated by an economic and eco-friendly process. The fine cracks were spontaneously generated. in, Sn ingot, which was reduced to powders in the repetition of phase transformation. The Sn nanopowder with 50 run in size was obtained by the 24th repetitions of phase transformation by low-temperature and ultrasonic treatments. Also, the $SnO_2$ powder was fabricated by the oxidation of the produced Sn powder to the ingot and milled by the ultrasonic milling method. The $SnO_2$ nanopowder of 20 nm in size was fabricated after the milling for 180 h.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.966-969
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• 2006

An optical model based on the optical thin-film theory is derived to calculate the output radiance of small molecules organic light-emitting diodes (OLEDs). We have designed the high efficiency OLEDs using the reflectance phase control of dielectric layers. It is found that OLED with a single $TiO_2$ dielectric layer is a good candidate to enhance the outcoupling efficiency and increase the color purity.

• 분석과학
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• 제8권4호
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• pp.477-480
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• 1995

Isotopic-spectral method [I] was applicated for determination of carbon in silicate materials (pure silica, guartz glasses, geological probs etc.). Isotopic heterogeneous balancing of carbon in gaseous phase and solid samples was carried out at the temperature of $1500-1900^{\circ}K$. Spectroscopic measuring of isotope concentration in a balanced gas was made using the electron-vibrational band heads of CO molecules excited in HF discharge. Limits of detection of carbon concentrations appear to be $n^*10^{-6}$.

• Bulletin of the Korean Chemical Society
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• 제25권11호
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• pp.1699-1702
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• 2004

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.241.2-241.2
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• 2002

A various 2-arylmethylpropionic acds(profen) have been widely used as non-steroidal anti-inllammatory drugs for the relief of acute and chronic rheumatoid arthritis and osteoarthritis. as well as for other connective tissue disorders and pains. Example is fenoprofen. ibuprofen, ketoprolen, and naproxen. All are chiral and, except for naproxen. are marketed in racemic form. Enantioseparations of profens have been of considerable interest because their anti-inflammatory and analgesic effects have been attributed almost exclusively to their (S)-enantiomer. (omitted)

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.105.1-105.1
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• 2002