• 멤브레인
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• 제22권5호
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• pp.342-351
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• 2012

본 연구에서는 PTMSP[poly(1-trimethylsilyl-1-propyne)]의 기체투과에 대한 선택도와 열적 안정성, 시간에 따른 노화현상으로 인한 투과특성의 감소를 개선하기 위해서 PTMSP/PDMS[poly(dimethylsioxane)] graft copolymer에 zeolite를 삽입하여 PTMSP/PDMS-NaY zeolite 복합막과 PTMSP/PDMS-NaA zeolite 복합막을 제조하였다. 물리 화학적 특성을 FT-IR, $^1H$-NMR, TGA, SEM, GPC을 사용하여 조사하였고, $H_2$와 $N_2$ 기체에 대한 투과도와 선택도 성질을 고찰하였다. PTMSP/PDMS-NaY zeolite 복합막과 PTMSP/PDMS-NaA zeolite 복합막 $H_2$와 $N_2$ 투과도는 PTMSP/PDMS graft copolymer 단일막보다 증가하였고, zeolite 함량이 증가함에 따라 증가하였다. 반면에 선택도($H_2/N_2$)는 zeolite 함량이 증가함에 따라 감소하였다. PTMSP/PDMS-NaA zeolite 복합막은 PTMSP/PDMS-NaY zeolite 복합막보다 높은 투과도와 선택도를 보였다.

• Nano
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• 제13권11호
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• pp.1850131.1-1850131.19
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• 2018

In this paper, an electrochemical sensor for epinephrine (EP), a neurotransmitter was developed by anchoring molecularly imprinted polymeric matrix (MIP) on the surface of gold-coated quartz crystal electrode of electrochemical quartz crystal microbalance (EQCM) using starch nanoparticles (Starch NP) - reduced graphene oxide (RGO) nanocomposite as polymeric format for the first time. Use of EP in therapeutic treatment requires proper dose and route of administration. Proper follow-up of neurological disorders and timely diagnosis of them has been found to depend on EP level. The MIP sensor was developed by electrodeposition of starch NP-RGO composite on EQCM electrode in presence of template EP. As the imprinted sites are located on the surface, high specific surface area enables good accessibility and high binding affinity to template molecule. Differential pulse voltammetry (DPV) and piezoelectrogravimmetry were used for monitoring binding/release, rebinding of template to imprinted cavities. MIP-coated EQCM electrode were characterized by contact angle measurements, AFM images, piezoelectric responses including viscoelasticity of imprinted films, and other voltammetric measurements including direct (DPV) and indirect (using a redox probe) measurements. Selectivity was assessed by imprinting factor (IF) as high as 3.26 (DPV) and 3.88 (EQCM). Sensor was rigorously checked for selectivity in presence of other structurally close analogues, real matrix (blood plasma), reproducibility, repeatability, etc. Under optimized conditions, the EQCM-MIP sensor showed linear dynamic ranges ($1-10{\mu}M$). The limit of detection 40 ppb (DPV) and 290 ppb (EQCM) was achieved without any cross reactivity and matrix effect indicating high sensitivity and selectivity for EP. Hence, an eco-friendly MIP-sensor with high sensitivity and good selectivity was fabricated which could be applied in "real" matrices in a facile manner.

• 수산해양교육연구
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• 제8권1호
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• pp.41-47
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• 1996

우리 나라 주변해역의 새로운 어업질서의 개편과 국제어업환경의 변화에 대처하기 위하여 다획을 위한 어구어법의 발전적 모색에서부터 선택적어업기술과 이와 관련한 연구가 보다 많이 요구되고 있으며, 우리 나라와 같이 원양어업을 대상으로 급진적으로 성장해 온 어업국은 연근해어업의 중요성이 새롭게 제고되고 있다. 본 연구에서는 1991년 6월부터 1992년 12월중에 시험조업기간을 통해 어획된 홍치를 대상으로 망목선택성을 분석하였다. 그 결과를 요약하면 다음과 같다. 1. 전장과 체고의 관계식은 BH=0.2562TL+2.9628, 전장과 체위의 관계식은, BG=0.6204TL+8.6402, 전장과 체중의 성장관계식은 $BW=7.34{\times}10^{-5}TL^{2.6956}$이었다. 2. 시험끝자루의 망목내경이 51.2mm, 7.02mm, 77.6mm 및 88.0mm에서 50% 선택체장과 선택계수는 각각 94.8mm, 1.85; 159mm, 2.27 ; 204mm, 2.09 ; 217.3mm, 2.18이었다. 3. 망목의 내경이 51.2mm, 88.0mm 끝자루의 범위내에서 규준곡선의 기울기와 절편은 각각 2.70, -5.7이었으며, 선택계수는 2.11이었다.

• Journal of Oral Medicine and Pain
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• 제25권1호
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• pp.9-28
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• 2000

The purpose of this article, the first part of series, is to describe the general theory applicable to various chromatographic procedures. History of chromatography, separation of matters, classification of chromatography, underlying principles of separation in chromatography, covering resolution, column efficiency, column selectivity, and capacity factor, movement of solute in chromatographic phase, including elution development, displacement development, and frontal analysis, were discussed. Mathematical description of plate theory and thermodynamic viewpoint of retention were emphasized.

• 한국수산과학회지
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• 제37권6호
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• pp.469-477
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• 2004

This study examined distributional patterns of Asterias amurensis in Tongyeong, the central South Sea of Korea. The density of the sea star was estimated at 10 chosen sites in the inner and the outer parts of the Tongyeong coast from December 2000. The mean density of the species in this area was $2.4ind./m^{2}$. The seasonal surveys conducted at 3 arbitrary chosen sites (i.e., sea cage, reef and soft sediment) also showed that the abundance of the species at the sea cage site $(density:\;3.6\;ind./m^{2};\;biomass:\;250.7\;gwwt/m^{2})$ was significantly higher than at the reef site $(density:\;1.7\;ind./m^{2};\;biomass:\;63.5\;gwwt/m^{2})$ and the soft sediment site $(density:\;0.4\;ind./m^{2};\;biomass:\;18.9\;gwwt/m^{2})$. Densities were higher at sea cages areas than at reefs and soft bottom sites. At sea cage site, A. amurensis population exhibited a strong aggregated distributional pattern. In contrast, at reef and soft bottom sites, A. amurensis population showed a random distributional pattern. The spatial difference in prey species and its abundance was the primary factor determining the spatial heterogeneity of the sea star in its behavior characteristics. Experiments on the feeding preference indicated that A. amurensis had a strong selectivity on its prey, but this selectivity varied between populations living in different sites. In particular, A. amurensis populations at the reef site showed a strong selectivity on various sessile and mobile animals living in reef areas, suggesting that these animal groups may play a role as "windows for the survival of A. amurensis". These results suggest that the distribution of A. amurensis in Tongyeong is closely associated with abundance of prey species and the bottom composition.

• 폴리머
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• 제37권3호
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• pp.288-293
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• 2013

A group of molecularly imprinted polymers (MIPs) with specific recognition for chiral (S)-ibuprofen were successfully prepared based on hydrogen bonds, utilizing ${\alpha}$-methacrylic acid as a functional monomer. The IR analysis of MIPs showed that the blue- and red-shifted hydrogen bonds were formed between templates and functional monomers in the process of self-assembly imprinting and re-recognition, respectively. According to UV-Vis analysis, we found that the ratio of host-guest complexes between template molecule and functional monomer was 1:1. The effect of cross-linker's quantity on the polymerization was studied by transmission electron microscope (TEM). The adsorption selectivity experiments indicated that MIPs exhibited higher selectivity to (S)-ibuprofen than those to ketoprofen and (R)-ibuprofen, (S)-ibuprofen's structural analogs.

• 전자공학회논문지D
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• 제34D권3호
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• pp.87-92
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• 1997

Inductively coupled Cl$_{2}$ plasma has been studied to etch Pt thin films, which hardly form volatile compound with any reactive gas at normal process temperature. Low etch rate and residue problems are frequently observed. For higher etch rate, high density plasma and higher process temperature is adopted observed. For higher etch rate, high density plasma and higher process temperature is adopted and thus SiO$_{2}$ is used as for patterning mask instead of photoresist. The effect of O$_{2}$ or Ar addition to Cl$_{2}$ was investigated, and the chamber pressure, gas flow rate, surce RF power and bias RF power are also varied to check their effects on etch rate and selectivity. The major etching mechanism is the physical sputtering, but the ion assisted chemical raction is also found to be a big factor. The proposs can be optimized to obtain the etch rate of Pt up to 200nm/min and selectivity to SiO$_{2}$ at 2.0 or more. Patterning of submicron Pt lines are successfully demonstrated.

• 한국재료학회지
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• 제30권10호
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• pp.515-521
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• 2020

Organic-inorganic hybrid perovskite nanocrystals have attracted a lot of attention owing to their excellent optical properties such as high absorption coefficient, high diffusion length, and photoluminescence quantum yield in optoelectronic applications. Despite the many advantages of optoelectronic materials, understanding on how these materials interact with their environments is still lacking. In this study, the fluorescence properties of methylammonium lead bromide (CH₃NH₃PbBr₃, MAPbBr₃) nanoparticles are investigated for the detection of volatile organic compounds (VOCs) and aliphatic amines (monoethylamine, diethylamine, and trimethylamine). In particular, colloidal MAPbBr₃ nanoparticles demonstrate a high selectivity in response to diethylamine, in which a significant photoluminescence (PL) quenching (~ 100 %) is observed at a concentration of 100 ppm. This selectivity to the aliphatic amines may originate from the relative size of the amine molecules that must be accommodated in the perovskite crystals structure with a narrow range of tolerance factor. Sensitive PL response of MAPbBr₃ nanocrystals suggests a simple and effective strategy for colorimetric and fluorescence sensing of aliphatic amines in organic solution phase.

• 멤브레인
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• 제16권2호
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• pp.123-132
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• 2006

PTMSP-silica-PEI 복합막이 PTMSP에 TEOS를 가하여 졸-겔 방법에 의해 제조되었다. 복합막의 특성은 $^1H-NMR$, FT-IR, TGA, XPS, SEM, GPC 등을 사용하여 조사하였고, 복합막의 기체투과 특성을 알아보기 위해 $H_2,\;O_2,\;N_2,\;CO_2,\;CH_4$를 사용하였다. PTMSP-silica-PEI 복합막의 기체 투과도는 TEOS의 함량이 증가함에 따라 증가하였다. $H_2$와 $CH_4$는 15 wt% TEOS에서 PTMSP-PEI 복합막보다 투과도와 선택도가 모두 증가하였다. 한편 $O_2$와 $CO_2$는 선택도의 감소없이 투과도가 증가하는 경향을 나타냈다.

• KSBB Journal
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• 제11권6호
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• pp.726-732
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• 1996

은행나무( Ginkgo bilaha 1.)의 잎으로부터 flavo­n noids 화합물틀을 Amberlite XAD-7으로 흡착시 키 는 최적 조건에 대한 연구를 수행하였다. 흡착제의 투입량, 수용액의 pH, 수용액의 조성 등의 흡착 조 건을 달리 하면서 flavonoids 화합물들의 흡착 경향 을 조사한 결과 20% 의 에탄올이 첨가된 pH 5.0의 수용액에 XAD-7이 15g/L의 양으로 투입된 경우 가장 선택적인 흡착이 이루어졌다. 이 경우 유기용 매 추출에 비해 약 98% 이상의 flavonoids 화합물 이 XAD-7에 흡착되었으며 selectivity도 약 50% 이상 증가된 85%를 나타내었다. 잎 내에 존재하는 여러 가지 화합물들 중 극성인 물질들은 수용액 내 에 용해되어 분리가 이루어졌고 flavonoids 화합물 에 비해 비극성인 지용성 물질들과 polyphen이류 등 은 흡착제가 투입되면 hydrophobic attraction에 의해 aggregation을 이루면서 석출이 되었다. 이로 인해 flavonoids 화합물들만이 흡착제로 이통하게 되 었다. 이와 같은 흡착 공청은 기존의 유기용매 추출 법에 비해 공정에 소요되는 경비와 시간을 크게 감 소시켜 새로운 분리 방법의 지표를 제시할 수 있을 것으로 기대된다.