• 제목/요약/키워드: UV spectrum

검색결과 557건 처리시간 0.027초

합성 금속-유기 골격체 NH2-MIL-101(Fe)를 이용한 염료의 흡착 및 광분해 제거 (Adsorption and Photocatalytic Degradation of Dyes Using Synthesized Metal-Organic Framework NH2-MIL-101(Fe))

  • 이준엽;최정학
    • 한국환경과학회지
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    • 제27권7호
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    • pp.611-620
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    • 2018
  • In this study, a metal-organic framework (MOF) material $NH_2$-MIL-101(Fe) was synthesized using the solvothermal method, and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV-visible spectrophotometry, field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and surface area measurements. The XRD pattern of the synthesized $NH_2$-MIL-101(Fe) was similar to the previously reported patterns of MIL-101 type materials, which indicated the successful synthesis of $NH_2$-MIL-101(Fe). The FT-IR spectrum showed the molecular structure and functional groups of the synthesized $NH_2$-MIL-101(Fe). The UV-visible absorbance spectrum indicated that the synthesized material could be activated as a photocatalyst under visible light irradiation. FE-SEM and TEM images showed the formation of hexagonal microspindle structures in the synthesized $NH_2$-MIL-101(Fe). Furthermore, the EDS spectrum indicated that the synthesized material consisted of Fe, N, O, and C elements. The synthesized $NH_2$-MIL-101(Fe) was then employed as an adsorbent and photocatalyst for the removal of Indigo carmine and Rhodamine B from aqueous solutions. The initial 30 min of adsorption for Indigo carmine and Rhodamine B without light irradiation achieved removal efficiencies of 83.6% and 70.7%, respectively. The removal efficiencies thereafter gradually increased with visible light irradiation for 180 min, and the overall removal efficiencies for Indigo carmine and Rhodamine B were 94.2% and 83.5%, respectively. These results indicate that the synthesized MOF material can be effectively applied as an adsorbent and photocatalyst for the removal of dyes.

갓(Brassica juncea)의 주 항균물질의 구조 분석 (Structural Analysis of Major Antimicrobial Substance Obtained from Leaf Mustard(Brassica juncea))

  • 강성구
    • 한국식품영양과학회지
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    • 제24권5호
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    • pp.702-706
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    • 1995
  • A major component(compound A) in the ethylacetate fraction exhibited a strong antimicrobial activity was identified by UV, IR, FABMS and NMR. The compound A showed strong absorbance at 209, 259 and 359nm, indicating a flavonoid ring structure. IR spectrum possessed absorbance of OH at 3400∼3300cm-1, ketone at around 1650cm-1, and aromatic C=C at around 1660cm-1. Molecular weight of the compound A calculated as 478 from the information of m/z 479(M+H)+ and m/z 477(M-H)+ in the FABMS spectrum. Molecular formula of this compound was found to be C22H22O12 from m/z 479.1220(+3.1mmu for C22H23O12) of HRFABMS spectrum and from 13C-NMR spectrum. 1H-NMR and 13C-NMR spectra of the compound A revealed aromatic proton and benzene rings. Distortionless enhancement by polarization transfer(DEPT) exhibited that the compound A possessed 10 quaternary carbons and 3 substituted benzene rings including a methoxy group substitution. The compound A was identified as isorhamnetin 3-O-β-glucopyranoside by spectrophotometric methods in conjunction with 1H-1H COSY, 1H-13C COSY and HMBC, which revealed a flavone with OH group at 3, 5, 7, and 4' and methoxy group at 3' positions esterified to glucose.

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지리산산(智異山産) 활엽수재(闊葉樹材) AcBr(acetyl bromide) Lignin의 UV Spectrum에 대(對)한 고찰(考察) (Studies on the UV Spectrum of AcBr Lingin from Hardwood Grown in Mt. Jiri)

  • 이동일;문창국
    • Journal of the Korean Wood Science and Technology
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    • 제14권4호
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    • pp.14-20
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    • 1986
  • 지리산(智異山)의 10종(種) 활엽수재에 대(對)한 AcBr(acetyl bromide) lignin의 UV spectrum을 조사(調査)한바 그 결과(結果)을 요약(要約)하면 다음과 같다. 1. 각수종(各樹種) 모두 spectrum curve의 최대정점(最大頂點)은 249nm에, 최소(最少) 정점(頂點)은 262-266nm에, 또 중간정점(中間頂點)은 270-280nm에 있었으며, Bj$\ddot{o}$rkman lignin이나 lignin sulfonic acid 등의 UV spectrum상(上)에서 볼수 있는 견(Shoulder)은 본(本) 연구(硏究)의 활엽수재 AcBr lignin의 spectrum에서는 볼수 없었다. 2. 10개(個) 수종(樹種) 각(各) 정점(頂點)의 평균흡광도(平均吸光度)는 249nm에서 0.457${\pm}$0.0077, 262-266nm에서 0.297${\pm}$0.0029, 280nm에서 0.309${\pm}$0.0067이었다. 3. 10개(個) 수종(樹種) 각(各) 정점(頂點)의 평균흡광계수(平均吸光係數)는 249nm에서 25.005${\pm}$0.3825, 262-266nm에서 16.264${\pm}$0.2347, 280nm에서 16.863${\pm}$0.3444였다. 4. 리그닌의 정량(定量)을 위(爲)한 270-280nm에서의 각(各) 수종별(樹種別) 리그닌의 흡광계수(吸光係數)는 다음과 같았다. 좁은잎단풍나무재(材) 16.939${\pm}$0.3735, 서어나무재(材) 17.411${\pm}$0.2937, 층층나무재(材) 16.579${\pm}$0.4348, 물푸레나무재(材) 16.385${\pm}$0.4140, 나도밤나무재(材) 16.287${\pm}$0.4156, 굴피나무재(材) 16.492${\pm}$0.1432, 산벗나무재(材) 16.343${\pm}$0.3177, 회화나무재(材) 17.549${\pm}$0.3253, 노각나무재(材) 18.400${\pm}$0.2925, 쪽동백 16.245${\pm}$0.4339였다. 5. 270-280nm에서 완만한 흡광도(吸光度) 정점(頂點)을 나타내는 것6으로 보아 본(本) 리그닌은 guaiacyl-syringyl lignin인 것으로 사료(思料)된다.

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광반응, 펜톤, 그리고 Fe$^{2+}$와 UV의 조합반응을 이용한 Triclosan의 분해 : 공정 비교 연구 (Degradation of Triclosan by the Photolysis, the Fenton, and the Hybrid Reaction with Fe$^{2+}$ and UV : A Comparative Study)

  • 손현석;조경덕
    • 대한환경공학회지
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    • 제30권5호
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    • pp.517-523
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    • 2008
  • 본 연구에서는 펜톤반응, 광반응, 그리고 Fe$^{2+}$와 UV의 조합반응을 이용하여 항균제이면서 신종오염물질 중의 하나인 Triclosan (TCS)에 대한 분해 메커니즘을 해석하였다. 결과에 의하면 Fe$^{2+}$의 산화율은 $H_2O_2$와 UV-C에서 각각 30%와 28%로 차이를 보이지 않은 반면 UV-A의 경우 15%로 차이를 보였다. TCS의 초기 분해속도는 광반응(UV-C > UV-A)이 Fe$^{2+}$와 UV 조합반응과 펜톤 반응보다 높았으나 반응시간의 경과와 함께 Fe$^{2+}$가 포함된 조합반응에서의 분해속도 증가가 관찰되었다. 또한 반응중 메탄올의 첨가에 의해 모든 반응에서 영향을 받았고 펜톤반응의 경우 20분 동안 분해효율 90%에서 5%로 급감되었다. 이온성 부산물인 Cl$^-$의 생성율은 Fe$^{2+}$와 UV-C 조합반응에서 가장 높았으며(77% / 150 min) 메탄올이 첨가된 반응 초기에서는(15 min) 12%의 Cl$^-$ 생성을 보인반면 다른 반응들은 무시할 수준($\leq$2%)이었다. TOC의 제거 역시 Fe$^{2+}$와 UV-C의 조합반응에서 가장 높았으며 펜톤반응, Fe$^{2+}$와 UV-A 조합반응, UV-C 광반응, 그리고 UV-A의 광반응 순으로 낮았다. 그러나 펜톤반응의 경우 90분 후 부터는 반응이 거의 중지되는 것이 관찰되었는데 이는 $H_2O_2$에 의한 Fe$^{2+}$의 산화반응이 중지되었기 때문이다. 이에 반해 Fe$^{2+}$와 UV의 조합공정에서 반응은 지속되었다. 또한 초기 Cl$^-$ 생성은 Fe$^{2+}$와 UV-C의 조합반응에서 환원반응에 의한 TCS의 분해메커니즘을 가지고 있다고 할 수 있다. 환원에 의한 분해는 할로겐화유기화합물의 무기화에 매우 유리하므로 TCS의 대안적 처리방법으로 UV-C와 Fe$^{2+}$의 조합반응은 적용가능하다.

답토양부식물(畓土壤腐植物)에 대(對)한 토양화학적연구(土壞化學的硏究)[I] -Humin 산(酸)과 Hymatomelan 산(酸)의 흡광(吸光) Spectrum- (Soil Chemical Studies on the Humic Substances of Paddy soils(I) -Photoabsorption Spectra of Humic acid and Hymatomelanic acid-)

  • 임선욱;김명종;이춘영
    • Applied Biological Chemistry
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    • 제12권
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    • pp.115-118
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    • 1969
  • 답토양부식물(畓土壤腐植物)에 대(對)한 일련(一連)의 토양화학적연구(土壞化學的硏究)에서 본실험(本實驗)은 수개(數個) 고위(高位)및 저위답토양(低位畓土壞)에서 부식물(腐植物)을 추출(抽出)하고 hymatomelan 산(酸)과 humin 산(酸)으로 분획(分劃)하여 가시(可視), 자외(紫外) 및 적외부(赤外部)에시 흡광(吸光) spectrum을 측정(測定)하여 비교검토(比較檢討)하였다. 토양비옥도(土壞肥沃度)의 차이(差異)에 따라 부식분획물(腐植分劃物)의 흡광(吸光)은 어느 광파역(光波域)에서도 별(別)다른 상이성(相異性)이 존재(存在)하지 않으며 자외광흡수(紫外光吸收) spectrum이 퇴비(堆肥)와 다른 유형(類型)의 토양(土壞)에서 분리(分離)한 부식산(腐植酸)의 spectrum과는 다르게 hymatomelan 산(酸)이 나 humin 산(酸) 모두 $235\;m{\mu}$에서 최고(最高), $395\;m{\mu}$에서 최저(最低)의 만곡접(灣曲點)을 나타내었다. 적외광흡수(赤外光吸收) spectrum은 양(兩) fraction간(間)에 상이점(相異點)을 보여 파수(波數) $1720\;cm^{-1}$에 특징적(特徵的)인 Peak가 존재하(存在)하며 이보다 장파역(長波域)($7.5{\sim}9.5{\mu}$)에서도 상이(相異)한 양상(樣狀)이었다. 또한 이 spectrum 들을 다른 연구자(硏究者)들에 의(依)한것과 대조(對照)하여 상이성(相異成)을 고찰(考察)하였다.

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오존/자외선에 의한 실리콘 웨이퍼의 정밀세정에 관한 연구 (A Study on the Contaminants Precision Cleaning of Etched Silicon Wafer by Ozone/UV)

  • 박현미;이창호;전병준;윤병한;임창호;송현직;김영훈;이광식
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 하계학술대회 논문집 C
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    • pp.1820-1822
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    • 2004
  • In this study, major research fields are classified as ozone generation system for dry cleaning wafer of etched silicon wafer, dry cleaning process of etched silicon wafer which includes SEM analysis and ESCA analysis. The following results are deduced from each experiment and analysis. The magnitudes of carbon and silicon were similar to the survey spectrum of silicon wafer which does not cleaning, but magnitude of oxygen was much bigger Because UV light activates oxygen molecules in the oxide film on the silicon wafer.

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뽕잎(桑葉)에 함유된 항산화성 물질 (Antioxidative Substances in Mulberry Leaves)

  • 신두호
    • 한국응용과학기술학회지
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    • 제15권3호
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    • pp.27-31
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    • 1998
  • Antioxodative substances in Mulberry leaves were examined. Antioxidative substances in Mulberry leaves were extracted by 80% methanol agueous solution. Antioxidative activity of extract was determined by examining hydrogen donating ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the inhibitory effect on the formation of the peroxide from Linoleic acid in the test tube at $50^{\circ}C$. Antioxidative substance were, then, separated and indentified by thin layer chromatography(TLC), UV-Vis spectrum and High performance liquid chromatography(HPLC) methods. Hydrogen donating ability on DPPH and antioxidative ability on linoleic acid of the extracted antioxidative substance were higher than those of 100ppm butylated hydroxy toluene(BHT). The extracted antioxidative substances were separated by TLC using ethylacetate : chloroform : formic acid : water(8 : 1 : 1 : 1 v/v) as a solvent, and a spot at Rf=0.35 was detected. The spot was scraped from the plate, and extrated by methanol. The extract was analyzed by UV-Vis spetra and HPLC, and chlorogenic acid was identified as a antioxidative substance.

천연염료에 관한 연구 ( I ) -자근색소의 추출 및 자외가시분광특성- (Studies on the Natural dyes( I ) -extraction and UV, VIS spectrum of coloring matter of gromwell-)

  • 조경래
    • 한국의류학회지
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    • 제11권3호
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    • pp.25-32
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    • 1987
  • The purpose of this study is to investigate optical behaviour of coloring matter of gromwell -extracted by water, acetic acid/methanol, and the other solvents. The results were as following: UV, VIS spectra of the solution of coloring matter of gromwell extracted by water at below $80^{\circ}C$ did not reveal in the range of the visible light wavelength and coloring matter of gromwell decomposed to blue particle at $95^{\circ}C$. The solution extracted by acetic acid/methanol was tinged with reddish purple and its spectra shifted to the longer wavelength according to increase of the solvent temperature. The color of the solution extracted by water became extinct as time went by, but that extracted by acetic acid/methanol kept up original color. In case of dried gromwell, extraction by acetic acid/methanol was easier than by water, and variation of spectra did not appear but showed hypochromic shift.

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Biosynthesis of Silver Nanoparticles by Phytopathogen Xanthomonas oryzae pv. oryzae Strain BXO8

  • Narayanan, Kannan Badri;Sakthivel, Natarajan
    • Journal of Microbiology and Biotechnology
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    • 제23권9호
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    • pp.1287-1292
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    • 2013
  • Extracellular biogenic synthesis of silver nanoparticles with various shapes using the rice bacterial blight bacterium Xanthomonas oryzae pv. oryzae BXO8 is reported. The synthesized silver nanoparticles were characterized by UV-Vis spectroscopy, powder X-ray diffractometry (XRD), scanning electron microscopy, energy dispersive X-ray spectrometry, and high-resolution transmission electron microscopy (HR-TEM). Based on the evidence of HR-TEM, the synthesized particles were found to be spherical, with anisotropic structures such as triangles and rods, with an average size of 14.86 nm. The crystalline nature of silver nanoparticles was evident from the bright circular spots in the SAED pattern, clear lattice fringes in the high-resolution TEM images, and peaks in the XRD pattern. The FTIR spectrum showed that biomolecules containing amide and carboxylate groups are involved in the reduction and stabilization of the silver nanoparticles. Using such a biological method for the synthesis of silver nanoparticles is a simple, viable, cost-effective, and environmentally friendly process, which can be used in antimicrobial therapy.

Microwave-assisted Solvent-free Synthesis of Some Dimethine Cyanine Dyes, Spectral Properties and TD-DFT/PCM Calculations

  • Zhang, Xiang-Han;Wang, Lan-Ying;Zhai, Gao-Hong;Wen, Zhen-Yi;Zhang, Zu-Xun
    • Bulletin of the Korean Chemical Society
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    • 제28권12호
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    • pp.2382-2388
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    • 2007
  • A series of dimethine cyanine dyes were synthesized in a fast, efficient and high yield by the condensation of quaternary salts with 1H-indole-3-carbaldehyde in the presence of piperidine under solvent-free microwave irradiation. The products were identified by 1H NMR, IR, UV-Vis spectra and elemental analysis. The absorption and fluorescence properties of these dyes were investigated both experimentally and theoretically. Calculations performed at a combination of time-dependent density functional theory (TD-DFT) and the polarizable continuum model (PCM) reproduced the π-π* type absorption bands of the dyes. Regression analysis was used for studying theoretical results of the absorption maxima in different solvents. Compared with experimental counterparts, estimated overall uncertainties in the absorption maxima were about ±2%.