• Journal of Powder Materials
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• v.17 no.3
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• pp.209-215
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• 2010

Mesoporous alumina particles were prepared by spray pyrolysis using cetyltrimethyl-ammonium bromide (CTAB) as a structure directing agent and the effect of Al precursor types on the texture properties was studied using $N_2$ adsorption isotherms, small-angle X-ray scattering (SAXS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The surface area and the microstructure of alumina particles were significantly influenced by the Al precursor type. The largest BET surface area was obtained when Al chloride was used, whereas alumina particles prepared from Al acetate had the largest pore volume. According to small-angle X-ray scattering (SAXS) analysis, the alumina powders prepared using nitrate and acetate precursors had a clear single SAXS peak around $2{\theta}=1.0{\sim}1.5^{\circ}$, indicating that regular mesopores with sponge-like structure were produced. On the basis of TEM, SAXS, and $N_2$ isotherm results, the chloride precursor was most profitable to obtain the largest surface area ($265\;m^2/g$), whereas, the nitrate precursor is useful for the preparation of non-hollow mesoporous alumina with regular pore size, maintaining high surface area (${\sim}233\;m^2/g$).

• Archives of Pharmacal Research
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• v.4 no.2
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• pp.75-84
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• 1981

As the cetyltrimenthy ammonium bromide (CTAB) concentration increases to $2{\times}10^{-4}$/M the absorption maximum of ethyl orange (EO) makes a blue shift from 475 mm to 395 mm. At higher concentration of CTAB than $2{\times}10^{-4}$ / M the absorption maximum shifts to higher wavelength than 395 nm. A new peak at 395 nm is shown to result from the mixed micelle due to dye stacking interaction rather than from a change in dye geometry. Because Raman spectra of EO on interaction with varying amount of CTAB are similar to that of EO in water. EO retains trans azo type on interaction with CTAB. There is a change of c.m.c.s. of CTAB for the mixed micelle in the presence of salt. The effect of added salt on C. M. C. of CTAB for the mixed micelle is given that the logarithm of the c. m. c. is a linear function of the logarithm of the sum of the c. m. c. and the concentration of added salt.

• Korean Journal of Materials Research
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• v.27 no.6
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• pp.307-311
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• 2017

Organometal halide perovskite materials, due to the tunability of their electronic and optical properties by control of composition and structure, have taken a position of significant importance in optoelectronic applications such as photovoltaic and lighting devices. Despite numerous studies on the structure - property relationship, however, practical application of these materials in electronic and optical devices is still limited by their processability during fabrication. Achieving nano-sized perovskite particles embedded in a polymer matrix with high loading density and outstanding photoluminescence performance is challenging. Here, we demonstrate that the careful control of nanoparticle formation and growth in the presence of poly(methyl methacrylate) results in perovskite nanoparticle - polymer nanocomposites with very good dispersion and photoluminescence. Furthermore, this approach is found to prevent further growth of perovskite nanoparticles, and thus results in a more uniform film, which enables fabrication using the perovskite nanoparticles.

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.521-524
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• 2001

A method using PCR was developed for the monitoring of glyphosate tolerant soybean (GTS) produced by the DNA recombination technique. We designed 3 pairs of specific oligonucleotide primers based on the gene sequences inserted in soybean and in lectin and ferritin genes as internal standards. Template DNAs were isolated from soybeans by the modified hexadecyl trimethyl ammonium bromide (CTAB)method and used for PCR with different primer sets. PCR, used with specific primer sets for GTS detection, showed the amplified DNA fragments with GTS template DNA but no product showed with non-GTS template. PCR amplified products were confirmed by DNA sequencing and were detected for up to 0.05% of GTS template DNA.

• Nano
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• v.13 no.10
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• pp.1850123.1-1850123.9
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• 2018

The cetyltrimethyl ammonium bromide (CTAB)-modified montmorillonite (MMT) was synthesized via a novel "dissolution and reassembly" method. To determine the optimal formula, the adsorption of C.I. Reactive Red 2 (X3B) with CTAB/MMT was investigated. The optimal CTAB/MMT nanocomposite was used to remove 2,6-dichlorophenol and p-nitrophenol from aqueous solutions. The adsorption results can be described by Langmuir isotherm, and the adsorption capacities were 200 mg/g and 125 mg/g for 2,6-dichlorophenol and p-nitrophenol, respectively. To realize the quick separation and recycle, the magnetic CTAB/MMT was further strategized and synthesized. The adsorption equilibrium time was 15 min for both contaminants; the ions' strength showed a little bit of influence on the adsorption performance. In addition, compared with acidic condition, neutral condition was more beneficial to the adsorption reaction. Due to the addition of $Fe_3O_4$, the adsorption capacities of this magnetic nanocomposite for 2,6-dichlorophenol and p-nitrophenol were a little bit decreased, which were 170 mg/g and 91 mg/g, respectively. However, the magnetic nanocomposite can be separated within 30 s under an external magnetic field, which would be useful in the practical application.

• Analytical Science and Technology
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• v.29 no.5
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• pp.219-224
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• 2016

불산 중 극미량 음이온의 고상추출과 이온크로마토그래프를 이용한 고감도 분석법이 개발되었다. 불산 중 불소이온이 고상에 의해 제거하였고 이어서 음이온 (F⁻, CH₃COO⁻, Cl⁻, Br⁻, NO₃⁻, PO₄³⁻, SO₄²⁻)들이 이온크로마토그래프를 이용하여 연속적으로 분리하였다. 고상 추출법에 영향을 주는 각 인자들 (흡착제의 선택, 시료의 부피 및 pH, 용출 용액과 용출용액의 부피)을 결정하였으며 그 결과 흡착제로서 Oasis WAX 컬럼이 가장 우수하였고 1.0 mL의 시료부피, 용출용액으로 50 mM 초산암모늄염 5 mL가 분리능에서 가장 우수하였다. 개발한 방법에 의한 음이온 (Cl⁻, Br⁻, NO₃⁻, PO₄³⁻, SO₄²⁻)들의 방법검출한계는 25 % 불산용액 (w/w) 중에 0.04~0.30 µg/L의 범위를 보였고 정밀도는 20.0와 40.0 µg/L의 농도에서 5 % 이내를 보였다. 한 제조회사에 의한 25 % 불산 중 음이온의 4.2에서 47.5 µg/L의 범위로 모두 검출되었다. 이 방법은 시험절차가 간단하고, 재현성 및 감도가 좋아서 반도체회사에서 불산 중 음이온 불순물을 정도 관리하는데 매우 유용한 방법이 될 것으로 판단된다.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.215.2-215.2
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• 2010

지구온난화의 주범으로 알려진 $CO_2$의 대기 중 농도는 산업혁명 이전 280ppm에서 산업 혁명 이후 375ppm으로 증가하였다. 정부 간 기후변화패널(IPCC)의 기후변화 시나리오에 의하면, 지금부터 다양한 감축노력을 한다 할지라도 $CO_2$ 증가추세는 계속되어 2100년경에는 대기 중 $CO_2$농도가 600~950ppm에 이를 것으로 예측하고 있다. 현재까지 화력발전부분은 온실가스($CO_2$)의 최대 배출 원으로 알려져 있으며 이 분야의 $CO_2$ 회수기술은 연소 후 포집(Post-combustion), 순산소 연소(Oxy-fuel combustion), 연소 전 탈탄소화(Pre-combustion) 3가지로 크게 구분된다. 이중 석탄가스화복합발전(IGCC)기술과 연계하여 $CO_2$를 회수할 수 있는 방법이 연소 전 탈탄소화 기술이다. 핵심기술은 $CO_2$ 분리공정으로 적용 될 수 있는 기술로서는 흡착 흡수법, 막분리법 그리고 가스 하이드레이트가 있으나 아직까지 우리나라의 가스 하이드레이트 기술은 전무한 형편이다. 본 연구에서는 가스 하이드레이트 형성원리를 이용하여 정온 정압 조건에서 $CO_2/H_2$ 하이드레이트를 제조하였으며 특히, 하이드레이트 형성 촉진제인 TBAB(Tetra-n-butyl ammonium bromide)를 첨가하여 TBAB 농도에 따른 상평형 및 속도론 실험을 수행 하였다. 또한 라만 분석을 통하여 $CO_2$ 회수 분리에 대한 연구도 병행하였다.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.153.2-153.2
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• 2010

화력발전 분야에서 $CO_2$ 분리는 크게 연소전 탈탄소화(pre-combustion capture)와 연소후 포획(post-combustion capture)으로 나누어진다, 연소후 포획은 연료를 연소한 후 발생하는 $CO_2$와 $N_2$가스에서 $CO_2$를 분리하는 기술로 흡수나, 흡착, 막분리 등을 주로 이용한다, 연소전 탈탄소화는 연소 전에 $CO_2$가 발생되지 않도록 하는 기술로써, 부분 산화나 개질 및 수성가스 변위반응 등이 포함되며 생성된 $H_2$와 $CO_2$를 분리하여 수소를 생산하는 기술($CO_2/H_2$분리가 핵심)이다. 우리나라는 대부분 연소후 포획 위주로 많은 연구가 진행되어 왔다, 하지만 최근 고유가 시장이 형성되면서 석탄화력 발전 및 복합가스발전(IGCC)에 필요한 연소전 탈탄소화($H_2/CO_2$ 가스로부터 $CO_2$ 회수) 연구에 산업적 관심이 급상승되고 있다. 특히, 연소전 탈탄소화 과정에서는 높은 자체압력(약 2.5 - 5.0MPa)과 비교적 높은 농도의 $CO_2$(약 40%의)가 발생되기 때문에, 연소전 탈탄소화는 가스하이드레이트 형성/분해 원리가 가장 잘 적용될 수 있는 기술이라 할 수 있다. 본 연구에서는 가스 하이드레이트 형성원리를 이용하여 정온 정압 조건에서 $CO_2/H_2$ 하이드레이트를 제조하였으며 특히, 하이드레이트 형성 촉진제인 THF(Tetrahydrofuran)와 TBAB(Tetra-n-butyl ammonium bromide)를 첨가하여 각각 0.5, 1, 3mol% 농도에 따른 상평형 및 속도론 실험을 수행 하였다. 또한 라만 분석을 통하여 $CO_2$ 회수 분리에 대한 연구도 병행하였다. 이러한 연구는 연소전 탈탄소화 기술에서의 $CO_2$ 회수 분리에 대한 핵심 연구임과 동시에 탄소배출권 규제에 실질적인 기여를 할 수 있을 것으로 사료된다.

• Journal of Microbiology and Biotechnology
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• v.28 no.1
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• pp.136-144
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• 2018

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis. Bacillus Calmette-$Gu\acute{e}rin$ (BCG) vaccine is the only TB vaccine currently available, but it is not sufficiently effective in preventing active pulmonary TB or adult infection. With the purpose of developing an improved vaccine against TB that can overcome the limitations of the current BCG vaccine, we investigated whether adjuvant formulations containing de-O-acylated lipooligosaccharide (dLOS) are capable of enhancing the immunogenicity and protective efficacy of TB subunit vaccines. The results revealed that the dLOS/dimethyl dioctadecyl ammonium bromide (DDA) adjuvant formulation significantly increased both humoral and Th1-type cellular responses to TB subunit vaccine that are composed of three antigens, Ag85A, ESAT-6, and HspX. The adjuvanted TB vaccine also effectively induced the Th1-type response in a BCG-primed mouse model, suggesting a potential as a booster vaccine. Finally, the dLOS/DDA-adjuvanted TB vaccine showed protective efficacy against M. tuberculosis infection in vitro and in vivo. These data indicate that the dLOS/DDA adjuvant enhances the Th1-type immunity and protective efficacy of the TB subunit vaccine, suggesting that it would be a promising adjuvant candidate for the development of a booster vaccine.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.1092-1096
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• 2008

Commercial food products from major cities of Coahuila, Mexico were screened to identify residues of transgenic deoxyribonucleic acid (DNA) and/or proteins. After performed, an inventory on all products that contained a soybean-based ingredient in a commercial grocery store in the city of Saltillo, Coahuila, Mexico, 245 food products were identified and grouped in 15 classes according to the soybean ingredient as well as the manufacturing process used for their elaboration. Similar sampling was made for the different food classes in the cities of Monclova, Piedras Negras, and Torreon. A total of 88 samples were analyzed and DNA was extracted by the hexadecyltrimethyl-ammonium bromide (CTAB) technique with slight modification to obtain better DNA quality (1). In addition, segments of the transgenic genes one that codifies for 5-enolpyruvylshikimate-3-phosphate synthase (epsps), cry 1A, and the cauliflower mosaic virus (CaMV) promoter were amplified using polymerase chain reaction (PCR). The transgenic proteins 5-enolpyruvylshikimate-3-phosphate synthase (CP4 EPSPS) and insecticidal crystal protein (Cry 1Ab/Ac) were identified using double antibody sandwich-enzymatic linked immunoassay analysis (DAS-ELISA). Presence of transgenic genes and/or proteins was identified in 35.3% of the commercial products samples.