• 한국환경농학회지
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• 제28권1호
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• pp.69-74
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• 2009

본 연구는 탄닌 성분이 다량 함유된 율피를 사용하여 폐수 중 중금속 3종(Cd, Pb, Cu)에 대한 흡착특성을 알아보고 향후 폐수처리공정에서 생물흡착소재의 적응가능성을 평가하고자 수행하였다. 실험에 사용한 인공폐수에는 Cu, Pb, Cd을 첨가하여 10, 20, 40, 60, 100, 150, 200 mg $L^{-1}$ 오염시켰으며 pH 5.5에서 흡착실험을 진행하였다. 율피의 중금속 흡착량은 중금속 유형별로 차이를 나타내었으며 중금속 농도가 증가함에 따라 흡착량이 증가하다가 점차 증가율이 감소하여 일절한 평형에 도달하는 경향을 나타내었는데 이는 율피의 표면이 피흡착물질로 채워져 비어있는 흡착가능 영역이 감소하기 때문인 것으로 판단되었다. 상기 연구 결과를 Freundlich 및 Langmuir 모델에 적응한 결과 $r^2$값은 Langmuir 모델에서 Pb, Cu, Cd 3가지 중금속 모두 0.99 이상으로 높게 나타났으며 각 중금속에 대한 율피의 흡착친화도는 Pb>Cu>Cd 순으로 최대흡착량($q_m$)은 Pb 31.25 mg $g^{-1}$, Cu 7.87 mg $g^{-1}$, Cd 6.85 mg $g^{-1}$로 조사되었다. FT-IR 분석결과 율피는 1080 $cm^{-1}$에서 carbonyl group, hydroxyl group, carboxyl group과 1200 $cm^{-1}$에서 1700 $cm^{-1}$ 사이의 carboxylate group, carboxyl group, methylene group, ester group 등이 존재하는 것으로 조사되었다. SEM 분석 결과 중금속 이온 흡착 전에는 표면이 매끄럽게 안정된 모습이 관찰되었지만 중금속 흡착 반응 후 전자밀도가 높은 부분이 관찰되어 중금속 이온이 흡착되었을 것으로 판단되었고 EDS 분석을 수행한 결과 중금속 이온의 흡착 후 표면의 납 이온 피크가 관찰되었다. 이상의 결과로부터 율피에 의한 중금속 이온의 흡착은 물리적인 흡착보다는 관능기에 의한 화학적 흡착일 것으로 판단되었다.

• 한국식품영양과학회지
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• 제35권10호
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• pp.1356-1362
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• 2006

본 연구는 함초의 효소적 가수분해물이 고콜레스테롤 식이 흰쥐의 항산화계와 지질과산화에 미치는 영향을 관찰하였다. 실험 동물은 체중 $150{\pm}10g$ 내외의 Sprague-Dawley 종 수컷 흰쥐를 사용하였으며, 정상식이 대조군(N), 정상식이에 함초 열수추출물 2% 공급군(NW-2), 고콜레스테롤식이 대조군(C) 및 고콜레스테롤식이에 함초 열수추출물을 각각 1%(CW-1), 2%(CW-2) 및 4%(CW-4) 공급한 군으로 하여 총 6군으로 나누었다. 식이 및 식수는 자유섭취하게 하였으며 3주간 사육한 후 희생시켰다. 체중증가량은 N군에 비해 C군에서 유의적으로 증가하였으며, 함초추출물 공급군들은 C군에 비해 다소 감소하였으나 유의적인 수준은 아니었다. 간조직 손상의 지표를 나타내는 GOT및 GPT 효소활성 변화를 측정한 결과 GOT는 각 군간에 유의성이 없었으나 GPT는 고콜레스테롤 식이 대조군에 비해 함초추출물 1% 및 2% 공급군에서 유의적으로 감소하여 함초의 효소적 가수분해물은 간독성에 영향을 미치지 않음을 알 수 있었다. 간조직 중의 항산화 방어계의 효소 활성을 측정한 결과 SOD 활성은 C군에 비해 함초추출물 공급군에서 다소 증가하였으며, 특히 함초추출물 2%를 공급한 CW-2군에서 유의적으로 증가하였다. GSHpx 활성은 함초추출물 공급군에서 증가하는 경향이었으며 특히 함초추출물 4% 공급군에서 유의적으로 증가하였다. Catalase 활성은 함초추출물 공급군에서 다소 증가하였으나 각 군간에 유의적인 차이가 없었다. 한편, 조직의 과산화적 손상의 지표가 되는 간조직의 TBARS 함량은 C군에서 N군에 비해 30% 증가되었으나 함초추출물 2%와 4% 공급군에서 C군에 비해 각각 23%와 26%씩 감소되었다. 또한, 간조직의 mitochondria에서 carbonyl 함량을 측정한 결과 N군에 비해 C군에서 29% 증가하였으나 함초추출물을 각각 1%, 2% 및 4% 공급한 군들에서 각각 31%, 30%및 26%씩 감소하여 정상군 수준이었다. 그러나 간조직의 microsome에서는 실험군 간의 유의적인 차이는 없었다. 이러한 결과로부터 함초의 효소적 가수분해물은 고콜레스테롤 식이 흰쥐 간조직의 항산화계를 강화시켜 조직의 산화적 손상을 감소시키는 항산화 효과가 있음이 규명되었다.

• Journal of Photoscience
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• 제7권4호
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• pp.143-148
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• 2000

Studies have been conducted to explore single electron transfer(SET) promoted photocyclization of ($\omega$-phthalimidoalkoxy)acetic acids(alkoxy=ethoxy, n-propoxy and n-butyloxy). Photocyclizations occur in methanol or acetone in high yields to produce cyclized products in which phthalimide carbonyl carbon is bonded to the carbon of side chain in place of the carboxylic group. These photocyclizations are thought to proceed through pathways involving intramolecular SET from oxygen in the $\alpha$-carboxymethoxy groups to the singlet excited state phthalimide moieties followed by decarboxylation of the intermediate $\alpha$-carboxymethoxy cation fadicals and cyclizations by radical coupling. The photocyclizations occur ca. three times faster in both methanol or acetone with one equivalent of sodium hydroxide added to the reactions and occur slower in acetone than in methanol. The efficient and regiselective cyclization reactions observed for photolyses in methanol represent synthetically useful processes for construction of heterocyclic compounds.

• Bulletin of the Korean Chemical Society
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• 제31권7호
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• pp.1993-1996
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• 2010

Silver nanoparticles has been prepared by the $\gamma$-irradiation and in situ reduction methods. Based on the Raman spectra, TEM images, X-ray Diffraction (XRD) patterns and UV-vis spectra, the in situ reduction method is more stable and the average size of the silver nanoparticles is also smaller than by the $\gamma$-irradiation reduction method. It is identified that the silver ions interacting with nonbonding electrons of oxygen atom in the carbonyl group of polyvinylpyrrolidone (PVP) by the in situ reduction method. It is also found advantages of the in situ reduction method including no additional reducing agents, without $\gamma$-irradiations treatment and the room temperature treatment suitability.

• Bulletin of the Korean Chemical Society
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• 제26권12호
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• pp.1941-1945
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• 2005

To raises the possibility of designing effective inhibitors, 3D-QSAR for the inhibition of calcineurin-NFAT signaling by new N-(4-oxo-1(4H)-naphthalenylidene benzenesulfonamide derivatives as inhibitors of intracellular protein-protein interactions were studied using CoMFA and CoMSIA methodology. The three templates, N-(4-oxo-1(4H)-naphthalenylidene)benzenesulfonamide (A), benzenesulfonamide (B) and 4-oxo-1(4H)-naphthalenylidene (C) were selected to improve the statistic of the present 3D-QSAR models. The best models with combination of standard field in CoMFA, and steric field and electrostatic field in CoMSIA derived from the template, B and C, because most of the compounds tend not to be aligned in template A. From the based on the CoMFA and CoMSIA contour maps, the $R_1$ and $R_2$ groups on 4-oxo-1(4H) naphthalenylidene ring are steric favor. The ortho position on the benzenesulfonyl ring is steric disfavor and the meta position is steric favor. In addition, the oxygene atom of carbonyl group will have better inhibition activities as it has a negative charge favor. From these findings, we can conclude that the analyses of the contour maps provided insight into possible modification of molecules for effective inhibitiors.

• Carbon letters
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• 제19권
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• pp.23-31
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• 2016

Carbon rich fly ash was recently reported to have compositions that are ideal for use as a precursor and catalyst for carbon nanotube growth. This fly ash powder is mostly composed of pure carbon, predominantly present as sp². In this work, the effect of sonication time on the morphology and structural properties of carbon rich fly ash particles is reported. The obtained results show that ultrasound treatment is an effective tool for producing ultrafine particles/fragments with higher porosity, which might be suitable for the adsorption of gasses. Moreover, carbon nanoparticles (CNPs) of this fly ash were produced in parallel using the ball milling technique, and were evaluated as reinforcements for epoxy based composites. These CNPs have almost spherical shapes with particle sizes of around 30 nm. They were found to have strong C=O carbonyl group bonds, which might be generated during the ball milling process. The tensile testing results of a fly ash CNP reinforced epoxy composite showed significant improvements in the mechanical properties, mainly in the stiffness of the polymer. The stiffness value was increased by around 23% of that of neat epoxy. These CNPs with chemically active groups might also be useful for other applications.

• 전기화학회지
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• 제14권2호
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• pp.83-91
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• 2011

Mesoporous titanium dioxide ($TiO_2$) thin films were prepared using poly(vinyl chloride)-graft-poly(N-vinyl pyrrolidone) (PVC-g-PVP) as a templating agent via sol-gel process. Grafting of PVC chains from PVC backbone was done by atom transfer radical polymerization (ATRP) technique. The successful grafting of PVP to synthesize PVC-g-PVP was checked by fourier-transform infrared spectroscopy (FT-IR) and gel permeation chromatography (GPC). The carbonyl group interaction of PVC-g-PVP graft copolymer with $TiO_2$ was confirmed by FT-IR. The porous morphologies of the $TiO_2$ films genereated after calcination at $450^{\circ}C$ was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The mesoporous $TiO_2$ films with 580 nm in thickness were used as a photoelectrode for solid state dye sensitized solar cell (DSSC) and showed an energy conversion efficiency of 1.05% at 100 $mW/cm^2$.

• 한국수소및신에너지학회논문집
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• 제28권1호
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• pp.17-23
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• 2017

Polyether ether ketone (PEEK) composite including tungstophosphoric acid(TPA) membranes have been intensively investigated for polymer electrolyte membrane water electrolysis (PEMWE) and thus covalently linked sulfonated polyether ether ketone (CL-SPEEK) with captured TPA composite membranes were prepared and characterized. Sulfonated polyether ether ketone (SPEEK) was prepared in sulfonation of PEEK and was cross-linked with 1,4 diiodobutane. The carbonyl group of SPEEK was reduced with $NaBH_4$ and 3-isocyanatepropyltriethoxysilane (ICPTES) was added. The TPA captured composite was prepared in reaction of TPA with 3-mercaptopropyltrime thoxysilane (MPTMS). The polymer composite membranes showed better thermostability and electrochemical properties than SPEEK. The membranes were prepared by sol-gel casting method. The polymer composite membrane featured 0.1285 S/cm of proton conductivity at $80^{\circ}C$ and outstanding durability.

• 한국수소및신에너지학회논문집
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• 제28권4호
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• pp.338-344
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• 2017

Polyoxometal molybdophosphoric acid (MoPA) bonded polyether ether ketone (PEEK) composite membrane for water electrolysis has been investigated. The composited membrane, covalently cross linked (CL) sulfonated polyether ether ketone (SPEEK) with a bonded MoPA, was prepared in sulfonation of PEEK, cross linkage reaction with 1,4-diiodobutane, and addition with MoPA. PEEK was covalently cross-linked with 1,4-diiodobutane to improve mechanical strength and was added with MoPA to increase proton conductivity. MoPA should be fixed to back bone of SPEEK to prevent bleeding out. Therefore, the carbonyl group of SPEEK was reduced with NaBH4 and 3-isocyanatepropyltriethoxysilane (ICPTES) was added. The MoPA bonded composite was produced in the reaction of MoPA with 3-mercaptopropyltrimethoxvsilane (MPTMS). In conclusion, MoPA bonded CL-SPEEK composite membrane featured 0.129 S/cm of proton conductivity at $80^{\circ}C$, and 2,156 hours of chemical stability in Fenton test. These properties are better than those of membranes of other SPEEK system.

• 한국염색가공학회지
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• 제20권6호
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• pp.1-7
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• 2008

The effects of $TiO_2$ contents and UV irradiation treatment on the surface properties of PLA films embedded with $TiO_2$ nanoparticle were investigated. Whereas UV irradiation decreased reflectance of the treated PLA films proportionally with increasing UV energy, the reflectance of PLA/$TiO_2$ films increased with increasing UV energy. The UV irradiation treatment caused PLA/$TiO_2$ blend films more polar as indicated in the generation of new carbonyl group and decrease in zeta potentials, which was more pronounced with the introduction of $TiO_2$. Upon UV irradiation, $TiO_2$ particles appeared on the film surface as observed in SEM images. The PLA/$TiO_2$ blend films showed photocatalytic properties such as photobleaching of methylene blue, deodorization of ammonia and antimicrobial activity in comparison with pure PLA films.