• Title/Summary/Keyword: UV-absorption

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The Isolation and Characterization of Chlorophyll-Protein Complexes in Thylakoid Membranes from Zoysia japonica and Spinach oleracea (잔디와 시금치의 Thylakoid Membrane으로부터 엽록소-단백질 복합체의 분리와 그 특성)

  • 김병규;장남기
    • Asian Journal of Turfgrass Science
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    • v.4 no.1
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    • pp.12-23
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    • 1990
  • The chlorophyll-protein complexes were separated from thylakoid membranes of Spinach oleracea and Zoysia japonica by two gel Systems of LiDodSO4-PAGE and LiDodSo4/Urea- PAGE under nondenaturing conditions. Seven chlorophyll~protein complexes of CPI*, CPI, CPII*. CP47, CP43, CP29 and CPII were fractionated from both S,oleracea and Zjaponica by LiDodSO4-PAGE. CPI, CP47 and CP43 contained more chlorophyll a than chlorophyll b. The patterns of their absorption spectra at room temperature were similliar to that of chlorophyll a, judging by their UV-spedtroscopy. On the other hand, CPII* and CPII contained approximately equim-olar quantities of chlorophyll a and b. Additional five chlorophyll-protein complexes not separated in the LiDodSO4-PAGE system were electrophoretically isolated from both S, oleracea and Zjaponica by LiDodSO4/Urca-PAGE. The chlorophyll-protein complex just above LRCII $\alpha$in the gel appears CCII-RC separeted recently. 23 kDa and 20 kDa cho-protein complexes is probably LHCIa and LHCIb as judged from their molecular weight. Two novel chlorophyll~protein complexes designated "CPI7" and "CPI6" were fractionate by this gel system. Their molecular weights respectively. Although the stoichiometry of their components and their roles in thylakoid membranes are not apparant, It is thought that they are another kinds of LHCI.other kinds of LHCI.

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Semiconductor coupled solar photo-Fenton's treatment of dyes and textile effluent

  • Raji, Jeevitha R.;Palanivelu, Kandasamy
    • Advances in environmental research
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    • v.5 no.1
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    • pp.61-77
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    • 2016
  • $NanoTiO_2$ was synthesized by ultrasonication assisted sol-gel process and subjected to iron doping and carbon-iron codoping. The synthesized catalysts were characterized by XRD, HR-SEM, EDX, UV-Vis absorption spectroscopy and BET specific surface area analysis. The average crystallite size of pure $TiO_2$ was in the range of 30 - 33 nm, and that of Fe-$TiO_2$ and C-Fe $TiO_2$ was in the range of 7 - 13 nm respectively. The specific surface area of the iron doped and carbon-iron codoped nanoparticles was around $105m^2/g$ and $91m^2/g$ respectively. The coupled semiconductor photo-Fenton's activity of the synthesized catalysts was evaluated by the degradation of a cationic dye (C.I. Basic blue 9) and an anionic dye (C.I. Acid orange 52) with concurrent investigation on the operating variables such as pH, catalyst dosage, oxidant concentration and initial pollutant concentration. The most efficient C-Fe codoped catalyst was found to effectively destruct synthetic dyes and potentially treat real textile effluent achieving 93.4% of COD removal under minimal solar intensity (35-40 kiloLUX). This reveals the practical applicability of the process for the treatment of real wastewater in both high and low insolation regimes.

Evaluation on the Contents of Antioxidative Substance at the Different Layers in Several Rice Varieties (몇 가지 벼품종 현미층위별 항산화 물질의 함량 평가)

  • 곽태순
    • Korean Journal of Plant Resources
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    • v.11 no.3
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    • pp.257-263
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    • 1998
  • Fifteen varieties of Oryza sativa mainly includig those of Korean native rice were exactly cutted into three layers such as L$_1$ layer (the outer part of 90% from rice center), L$_2$ layer(the part of 81 ~ 91% from the rice center) and L$_3$ layer(the inner part of 80% from the rice center) and ferulic acid derivatives, which play an important role of antioxidative action, were quantitiavely analyzed by UV absorption spectrometric method at fixed 314nm. From this experiment, it was found that the more it enters from the surface into the rice center, the more those secondary metabolites contents were highly reduced. The varieties showing contents more than 20 mg/g were as follows: Hwasunchalbyeo(25.8mg/g), Jojeongdo(24.1mg/g), Suwon425(21.2mg/g), Daigolbyeo(20.6mg/g) and Nonglimna 1(20.2mg/g) by this order. Estimation onthe anthocyanin contents of both Suwon 425 and Sanghehanghyeolna revealed that its total. contents were very exactly close each other. However, it was charateristically differentiated in the contents of L$_2$ layer with respect to showing a considerably higher content of Suwon 425 than of Sanghaehanghyeolna. Conclusively, the selected Suwon 425 variety, which is coloured and flavour volatile one, showed relatively higher contents of anthocyanin, ferulic acid derivatives in the L$_2$ layer as well as L$_1$ layer when compared with Sanghaehangyeolna and even other varieties. This fact suggested that Suwon 425 could be a promising candidate for the development of health rice food.

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Physiological Pharmacokinetic Model of Ceftriaxone Disposition in the Rat and the Effect of Caffeine on the Model

  • Kwon, Kwang-Il;Bourne, David-W.A.
    • Archives of Pharmacal Research
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    • v.13 no.3
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    • pp.227-232
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    • 1990
  • A Physiologically based pharmacokinetic model was used to describe the distribition and elimination of cefriazone in the rat. To validate the practical application of the model, the effect of cffeine on the model was also examined. The model consisted of eleven compartments representing the major sites for ceftriaxone distribution including carcass which served as a residual compartment. Elimination was represented by renal and hepatic (metabolic biliary )excretion with GI secretion and re-absorption. The drug concentrations in most of the tissues were simulated using flow limited equations while brain levels were simulated using membrane limited passive diffusion distribution. The experimental data were obtained by averaging the concentration of drug in the plasma and tissues of five rats after i. v. injection of cefriazone 100 mg/kg without and with caffeine 20 mg/kg. The data for the amount of ceftriazone excreted in urine and gut contents were used to apportion total body clearance. HPLC with UV detection was used for the assay with 0.1-0.2 $\mu$g/ml sensitivity. The great majority of drug concentrations with and without caffeine show reasonably good agreements to the simulation results within 20%. The effect of caffeine on renal and hepatic clearances was apparent with 18.8% and 18.6% increase in the model values, respectively.

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Nelumbo nucifera extracts mediated synthesis of silver nanoparticles for the potential applications in medicine and environmental remediation

  • Supraja, N.;Avinash, B.;Prasad, T.N.V.K.V.
    • Advances in nano research
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    • v.5 no.4
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    • pp.373-392
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    • 2017
  • Silver nanoparticles (AgNPs) were successfully synthesized through a simple green route using the Nelumbo nucifera leaf, stem and flower extracts. These nanoparticles showed characteristic UV-Vis absorption peaks between 410-450 nm which arises due to the plasmon resonance of silver nanoparticles. The Fourier transform infrared spectroscopy (FT-IR) confirmed the presence of amides and which acted as the stabilizing agent. X-ray diffraction spectrum of the nanoparticles confirmed the Face centered cubic (FCC) structure of the formed AgNPs. Dynamic light scattering technique was used to measure hydrodynamic diameter (68.6 nm to 88.1 nm) and zeta potential (-55.4 mV, -57.9 mV and 98.9 mV) of prepared AgNPs. The scanning electron micrographs of dislodged nanoparticles in aqueous solution showed the production of reasonably monodispersed silver nanoparticles (1-100 nm). The antimicrobial activity of prepared AgNPs was evaluated against fungi, Gram-positive and Gram-negative bacteria using disc diffusion method. Anti-corrosion studies were carried out using coupon method (mild steel and iron) and dye degradation studies were carried out by assessing photo-catalytic activity of Nelumbo nucifera extracts mediated AgNPs.

Synthesis of LaMnO3-Diamond Composites and Their Photocatalytic Activity in the Degradation of Weak Acid Red C-3GN

  • Huang, Hao;Lu, Benqian;Liu, Yuanyuan;Wang, Xeuqian;Hu, Jie
    • Nano
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    • v.13 no.10
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    • pp.1850121.1-1850121.11
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    • 2018
  • In this study, a series of $LaMnO_3$-diamond composites with varied $LaMnO_3$ mass contents supported on micro-diamond have been synthesized using a sol-gel method. The as-prepared composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and the Fourier transform infrared spectra (FTIR). Meanwhile, the photocatalytic performances were also tested by photoluminescence (PL) spectroscopy, ultraviolet-visible diffuse reflection spectra (UV-Vis DRS) and the degradation of weak acid red C-3GN (RC-3GN). Results show that the peak position of $LaMnO_3$ is shifted to low angle after the introduction of diamond, and perovskite particles uniformly distributed on the surface of diamond, forming a network structure, which can increase the active sites and the absorption of dye molecules. When the mass ratio of $LaMnO_3$ and diamond is 1:2 (LMO-Dia-2), the composite shows the most excellent photocatalytic activity. This result offers a sample route to enlarge the range of the application of micro-diamond and provide a new carrier for perovskite photocatalysts.

The Study on the Physicochemical Properties of Fluid under High Pressure (Ⅱ). The Effect of Pressure and Temperature on the Hexamethyl Benzene-Iodine Charge Transfer Complex in n-Hexane

  • Kwun Oh Cheun;Kim Jeong Rim
    • Bulletin of the Korean Chemical Society
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    • v.6 no.4
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    • pp.186-191
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    • 1985
  • The effect of pressure and temperature on the stabilities of the charge transfer complexes of hexamethyl benzene with iodine in n-hexane has been investigated by UV-spectrophotometric measurements. In this experiment the absorption spectra of mixed solutions of hexamethyl benzene and iodine in n-hexane were measured at 25, 40 and $60^{\circ}C$ under 1,200, 600, 1200 and 1600 bar. The equilibrium constant of the complex formation was increased with pressure while being decreased with temperature raising. Changes of volume, enthalpy, free energy and entropy for the formation of the complexes were obtained from the equilibrium constants. The red shift at higher pressure, the blue shift at higher temperature and the relation between pressure and oscillator strength were discussed by means of thermodynamic functions. In comparison with the results in the previous studies, it can be seen that the pressure dependence of oscillator strength has a extremum behavior in durene as the variation of ${\Delta}H$ or ${\Delta}S$ with the number of methyl groups of polymethyl benzene near atmospheric pressure in the previous study. The shift or deformation of the potential in the ground state and in the excited state of the complexes formed between polymethyl benzene and iodine was considered from the correlation between the differences of the electron transfer energies and the differences of free energies of the complex formation for the pressure variation.

Synthesis and Characterization of the Layered Type $(C_nH_{2n+1}NH_3)_2PbCl_4$ System

  • Lee, Su Jong;Kim, Gye Ya;O, Eun Ju;Kim, Gyu Hong;Yeo, Cheol Hyeon
    • Bulletin of the Korean Chemical Society
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    • v.21 no.3
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    • pp.317-320
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    • 2000
  • Layered $K_2NiF_4$type ($C_nH_{2n+1}NH_3)_2PbCl_4$(n=6, 8 and 10) system, or alkylammonium tetrachloroplumbate compound, has been synthesized from $PbCl_2$ and $C_nH_{2n+1}NH_3Cl$ solutions under argon ambient pressure for 12hrs at $90^{\circ}C$. The crystal structure of the compound has been analyzed using X-ray powder diffaction in the range of $5^{\circ}{\leq}2{\theta}{\leq}55^{\circ}$, and all samples assigned to an orthorhombic system. Local distances of the Pb-Cl bond have been determined by Pb $L_{III}$-edge extended X-ray absorption fine structure (EXAFS) spectroscopy. The vibration modes of alkylammonium chains and the absorpton peaks of an excition have been examined by FT-IR and UV-Vis. reflectance spectra, respectively. The phase transition temperatures of the compounds have been studied by using DSC. According to the thermal analysis, two phase transition temperatures have been observed in the compositons of n=8 and 10.

IR Absorption Property in Nano-thick Ir-inserted Nickel Silicides (이리듐이 첨가된 니켈실리사이드의 적외선 흡수 특성)

  • Yoon, Kijeong;Song, Ohsung;Han, Jeungjo
    • Korean Journal of Metals and Materials
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    • v.46 no.11
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    • pp.755-761
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    • 2008
  • We fabricated thermally evaporated 10 nm-Ni/1 nm-Ir/(poly)Si films to investigate the energy saving property of silicides formed by rapid thermal annealing (RTA) at the temperature range of $300{\sim}1200^{\circ}C$ for 40 seconds. Moreover, we fabricated 100 nm-thick ITO/(poly)Si films with an rf-sputter as references. A transmission electron microscope (TEM) and an X-ray diffractometer were used to determine cross-sectional microstructure and phase changes. A UV-VIS-NIR and FT-IR (Fourier transform infrared spectroscopy) were employed for near-IR and middle-IR absorbance. Through TEM analysis, we confirmed 20~65 nm-thick silicide layers formed on the single and polycrystalline silicon substrates. Ir-inserted nickel silicide on single crystalline substrate showed almost the same absorbance in near IR region as well as ITO, but Ir-inserted nickel silicide on polycrystalline substrate, which had the uniform absorbance in specific region, showed better absorbance in near IR region than ITO. The Ir-inserted nickel silicide on polycrystalline substrate particularly showed better absorbance in middle IR region than ITO. The results imply that nano-thick Ir-inserted nickel silicides may have excellent absorbing capacity in near-IR and middle-IR region.

Green Synthesis of Nanoparticles Using Extract of Ecklonia Cava and Catalytic Activity for Synthetic Dyes

  • Kim, Beomjin;Song, Woo Chang;Park, Sun Young;Park, Geuntae
    • Journal of Environmental Science International
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    • v.29 no.12
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    • pp.1171-1184
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    • 2020
  • The green synthesis of inorganic nanoparticles (NPs) using biomaterials has garnered considerable attention in recent years because of its eco-friendly, non-toxic, simple, and low-cost nature. In this study, we synthesized NPs of noble metals, such as Ag and Au using an aqueous extract of a marine seaweed, Ecklonia cava. The formation of AgNPs and AuNPs was confirmed by the presence of surface plasmon resonance peaks in UV-Vis absorption spectra at approximately 430 and 530 nm, respectively. Various properties of the NPs were evaluated using characterization techniques, such as dynamic light scattering, transmission electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction analysis. Phytochemicals in the seaweed extract, such as phlorotannins, acted as both reducing and stabilizing agents for the growth of the NPs. The green-synthesized AgNPs and AuNPs were found to exhibit high catalytic activity for the decomposition of organic dyes, including azo dyes, methylene blue, rhodamine B, and methyl orange.