• 생명과학회지
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• 제23권5호
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• pp.676-681
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• 2013

퍼클로레이트(${ClO_4}^-$)는 지표수 및 토양/지하수에서 검출되는 신규 오염물이다. 퍼클로레이트 환원세균(PRB)은 ${ClO_4}^-$를 무해한 최종산물로 전환시킬 수 있으므로 ${ClO_4}^-$ 제거는 미생물을 이용한 방법이 가장 적절한 것으로 알려졌다. 이전 연구[3]를 통해 원소 황 입자와 활성슬러지를 이용하여 독립영양방식의 ${ClO_4}^-$ 제거가 가능하다는 실험적 증거가 제시되었다. 입자상 황은 비교적 값이 저렴하고, 활성슬러지는 하수처리장으로부터 쉽게 구할 수 있는 장점이 있다. 그래서 본 연구에서는 원소 황을 전자공여체로 사용하였을 때 여러 환경요인이 활성슬러지 미생물의 ${ClO_4}^-$ 분해에 미치는 영향을 회분반응으로 조사하였다. 이 회분반응의 결과를 통해 활성슬러지 미생물에 의한 독립영양방식의 ${ClO_4}^-$ 분해를 위한 최적조건을 도출하였다. 또한 활성슬러지로부터 농화배양된 황산화 PRB는 활성슬러지보다 ${ClO_4}^-$ 제거능이 우수한 것으로 회분반응 결과 나타났다. 그래서 본 연구결과는 최적조건 적용 및 농화배양된 접종균을 통해 원소 황과 활성슬러지를 이용한 독립영양방식의 ${ClO_4}^-$ 제거를 향상할 수 있다는 것을 나타내었다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2006년도 춘계학술발표대회 및 제10회 신소재 심포지엄 논문개요집
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• pp.26.1-26.1
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• 2006

• Bulletin of the Korean Chemical Society
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• 제33권9호
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• pp.2949-2954
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• 2012

Nano ZnO with an average size of 8 nm was prepared by thermal decomposition of zinc oxalate at $450^{\circ}C$. A series of based composite polymer electrolyte PEO-$LiClO_4$ and nano ZnO as a filler have been synthesized using solution cast technique, with varying the filler ratio systematically. XRD, DSC and FTIR studies have been conducted to investigate the structure and interaction of different groups in the composite polymer electrolyte. Effect of nano ZnO ceramic filler concentration on the structure of composites and their electrical properties (DC-conductivity, AC-conductivity, dielectric constant, dielectric loss and impedance) at different frequencies and temperatures was studied. Melting temperature ($T_m$) of PEO decreased with the addition of both $LiClO_4$ salt and nano ZnO filler due to increasing the amorphous state of polymer. All composite samples showed an ionic conductivity. The maximum room temperature ionic conductivity is found for $(ZnO)_{0.5}(PEO)_{12}(LiClO_4)$ composite sample. All the results are correlated and discussed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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• pp.863-866
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• 1999

(Ba,Sr)$TiO_3$ thin films have attracted groat interest as new dielectric materials of capacitors for ultra-large-scale integrated dynamic random access memories (ULSI-DRAMs) such as 1 Gbit or 4 Gbit. In this study, inductively coupled $BCl_3/Cl_2$/Ar plasmas was used to etch (Ba,Sr)$TiO_3$ thin films. RF power/dc bias voltage = 600 W/-250 V and chamber pressure was 10 mTorr. The $Cl_2/(Cl_2+Ar)$ was fixed at 0.2, the (Ba,Sr)$TiO_3$ thin films were etched adding $BCl_3$. The highest (Ba,Sr)$TiO_3$ etch rate is 480$\AA/min$ at 10 % $BCl_3$ adding to $Cl_2$/Ar. The characteristics of the plasmas were estimated using optical emission spectroscopy (OES). The change of Cl, B radical density measured by OES as a function of $BCl_3$ percentage in $Cl_2$/Ar. The highest Cl radical density was shown at the addition of 10% $BCl_3$ to $Cl_2$/Ar. To study on the surface reaction of (Ba,Sr)$TiO_3$ thin films was investigated by XPS analysis. Ion enhancement etching is necessary to break Ba-O bond and to remove $BaCl_2$. There is a little chemical reaction between Sr and Cl, but Sr is removed by physical sputtering. There is a chemical reaction between Ti and Cl, and Tic14 is removed with ease. The cross-sectional of (Ba,Sr)$TiO_3$ thin film was investigated by scanning electron microscopy (SEM), the etch slope is about $65\;{\sim}\;70$.

• KSBB Journal
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• 제13권2호
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• pp.168-173
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• 1998

Gamma irradiated and non-irradiated Agrimonia pilosa Ledebour were extracted by 70% ethanol. The combined effects of the Agrimonia pilosa Ledebour extract and NaCl on survival of Escherichia coli O157:H7 in tryptic soy broth were investigated. E. coli O157:H7 decreased ca 1 log cycle by the addition of 2% sample extract, and the anthbacterial activity was increased as the concentration of sample extract was increased. The irradiation effect of the sample on antibacterial activity was not observed. On the treatment of NaCl alone, E. coli O157:H7 was inactivated (ca 3~4 log cycle reduction within 48 hr) in more than 7% NaCl. The higher inactivation(ca 5 log cycle reduction within 48 hr) occurred in the presence of 2% sample extract and 5% NaCl than in the addition of each alone. The extracted antibacterial substance was stable in the pH range of 4.0 to 7.0, heat treatment at 121$^\circ C$ for 15 min, and freezing at -18$^\circ C$ and thawing at 37$^\circ C$. There fore, the sample extract, would substantially increase the food-safety in terms of E. coli O157:H7.

• 폴리머
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• 제39권1호
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• pp.169-173
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• 2015

3-Aminopropyltrimethoxysilane(1NS) 또는 N-[3-(trimethoxysilyl)propyl]ethylenediamine(2NS)으로 표면 기능화된 실리카에 1-butyl-4-methylpyridinium chloride(Cl)와 tributylmethylammonium chloride(Amm), benzyldimethyltetradecylammonium chloride(Ben), 1-butyl-1-methylpyrrolidinium chloride(Pyr)와 같은 이온성 액체를 이용하여 표면처리한 후 메탈로센 촉매를 담지하여 에틸렌 중합을 실시하였다. $SiO_2/1NS/IL/(n-BuCp)_2ZrCl_2$ 촉매와 $SiO_2/2NS/IL/(n-BuCp)_2ZrCl_2$ 촉매의 Zr 함량은 아미노실란 화합물로만 표면 처리된 촉매보다 감소하였다. $SiO_2/1NS/IL/(n-BuCp)_2ZrCl_2$ 촉매의 중합 활성은 $SiO_2/1NS/(n-BuCp)_2ZrCl_2$ 촉매보다 증가하였다. 반면, $SiO_2/2NS/IL/(n-BuCp)_2ZrCl_2$은 Zr 함량의 감소로 중합 활성은 $SiO_2/2NS/(n-BuCp)_2ZrCl_2$ 촉매에 비해 감소하였다.

• 방사성폐기물학회지
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• 제20권2호
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• pp.193-207
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• 2022

Thermodynamically, TRUO_x, REO_x, and SrO_x can be chlorinated using ammonium chloride (NH₄Cl) as a chlorinating agent, whereas uranium oxides (U₃O₈ and UO₂) remain in the oxide form. In the preliminary experiments of this study, U₃O₈ and CeO₂ are reacted separately with NH₄Cl at 623 K in a sealed reactor. CeO₂ is highly reactive with NH₄Cl and becomes chlorinated into CeCl₃. The chlorination yield ranges from 96% to 100%. By contrast, U₃O₈ remains as UO₂ even after chlorination. We produced U/REO_x- and U/SrO_x-simulated fuels to understand the chlorination characteristics of the oxide compounds. Each simulated fuel is chlorinated with NH₄Cl, and the products are dissolved in LiCl-KCl salt to separate the oxide compounds from the chloride salt. The oxide compounds precipitate at the bottom. The precipitate and salt phases are sampled and analyzed via X-ray diffraction, scanning electron microscope-energy dispersive spectroscopy, and inductively coupled plasma-optical emission spectroscopy. The analysis results indicate that REO_x and SrO_x can be easily chlorinated from the simulated fuels; however, only a few of U oxide phases is chlorinated, particularly from the U/SrO_x-simulated fuels.

• 한국약용작물학회지
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• 제5권2호
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• pp.102-107
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• 1997

명일엽(明日葉)의 부위별 캘러스 유도율을 조사하였고, 배발성(胚發生) 캘러스로부터 식물체 재분화율을 높이고자 에틸렌 작용억제제(作用抑制劑)를 처리한 후, 신초(新梢)의 발생정도 및 소식물체의 길이와 무게를 조사하였던 바 그 결과는 다음과 같다. 1. 2, 4-D의 농도를 달리한 MS배지에 명일엽(明日葉)의 소엽(小葉), 소엽병(小葉柄) 및 엽병(葉柄) 절편(切片)을 배양하였을 때 캘러스 유도는 소엽(小葉)에서 잘 되었으며 2, 4-D의 농도는 2.0 ppm에서 제일 좋았다. 2. 배발성(胚發生) 캘러스로부터 신초의 발생정도와 재분화(再分化)된 소식물체(小植物體)의 신초(新梢) 신장(伸長)에는 $AgNO_3$는 2 ppm, $CoCl_2{\cdot}6H_2O$는 10ppm 첨가가 제일 효과적이었으며, $AgNO_3$나 $CoCl_2{\cdot}6H_2O$를 2, 4-D 1 ppm과 혼용처리하면 신초의 발생정도와 신장은 억제되었다. 3. 재분화된 소식물체(小植物體)의 뿌리 신장(伸長)에는 $AgNO_3$는 1 ppm, $CoCl_2{\cdot}6H_2O$는 5 ppm 첨가가 제일 효과적이었는데, $AgNO_3$나 $CoCl_2{\cdot}6H_2O$를 2, 4-D 1 ppm과 혼용처리 하면 뿌리의 발생은 없었다. 4. 재분화된 소식물체(小植物體)의 생체중은 $AgNO_3$나 $CoCl_2{\cdot}6H_2O$를 단용처리한 경우 각각 2 rpm에서, 2, 4-D 1 ppmr과 혼용처리한 경우 $AgNO_3$는 1 ppm 과 $CoCl_2{\cdot}6H_2O$는 2 ppm에서 제일 무거웠다.

• 한국표면공학회지
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• 제28권1호
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• pp.46-54
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• 1995

An electrochromic(EC) cell was constructed using $WO_3$ as a electrochromic material and NiO as a counter electrode, deposited onto ITO-coated glass by the implementation of electron beam evaporation. The electrolytic media were both lithium and proton conducting polymers such as poly-acrylonitrile(PAN)-$LiClO_4$, poly-ethylene oxide(PEO)-$LiClO_4$, poly-vinyl butyral(PVB)-LiCl and PVB-H$_3$$PO_4$. Potentiodynamic cycling of the cells using PAN-$LiClO_4$, or PVB-$H_3$$PO_4$ electrolyte yielded a transmission variation of more than 40% at the wavelength of 632.8 nm within less than 10 sec response time at room temperature. These results indicate that these electrolytes, transparent in gel type, are premising for the application in large area electrochromic windows.

• 대한화학회지
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• 제39권4호
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• pp.318-322
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• 1995