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Transmittance Spectroscopy (transmittance + spectroscopy)
Selected AbstractsPossibilities of using near infrared reflectance/transmittance spectroscopy for determination of polymeric protein in wheatJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 8 2007Éva Scholz Abstract Possibilities of using near-infrared reflectance and near-infrared transmittance (NIR/NIT) spectroscopic techniques for detecting differences in amount and size distribution of polymeric proteins in wheat were investigated. To evaluate whether differences in polymeric protein due to genetic or environmental variations were detectable by NIR/NIT techniques, wheat materials of different background were used. Size-exclusion high-performance liquid chromatography was applied to detect variation in polymeric protein. Partial least squares regression gave high R2 values between many protein parameters and NIR/NIT spectra (particularly second-derivative spectra of NIR 1100,2500 nm region) of flours, while no such relationship was found for whole wheat grains. Most and highest correlations were found for total amount of extractable and unextractable proteins and monomer/polymer protein ratio. Some positive relationships were found between percentage of total unextractable polymeric protein in the total polymeric protein and percentage of large unextractable polymeric protein in the total large polymeric protein and NIR/NIT spectra. Thus, it was possible to detect differences in polymeric proteins with NIR/NIT techniques. The highest amount of positive correlations between NIR/NIT spectra and protein parameters was found to be due to environmental influences. Some correlations were found for breeding lines with a broad variation in gluten strength and polymeric protein composition, while a more homogeneous sample showed less correlation. Thereby, detection of variation in amount and size distribution of polymeric protein due to cultivar differences with NIR/NIT methods might be difficult. Copyright © 2007 Society of Chemical Industry [source] A microwave-assisted process for coating polymer and glass surfaces with semiconducting ZnO submicron particlesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2009Alexander Irzh Abstract A new method for coating glass slides with ZnO particles with an average size of 200 nm is proposed in the current article. The coating was performed under microwave radiation. Two main morphologies are found for the ZnO crystals that are deposited on glass slides. The first morphology is that of a very dense coating of ZnO hexagonal rods growing perpendicular to the glass surface. The second is the growth of ZnO flower-like particles. In addition to coating the glass by ZnO particles, we also report on coating other polymers [poly(methyl methacrylate) plate, polycarbonate beads, Nylon 6,6 beads, and polypropylene beads) by ZnO. The morphology obtained for ZnO coated on polymers is different from that detected for coating ZnO on glass. The unorganized coating of ZnO rods on polymers has been observed. The coated glass slides were characterized by X-ray diffraction, volumetric titration, EDS, scanning electron microscope, and optical measurements (DRS and transmittance spectroscopy). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source] IR spectroscopy of adsorbates on ultrathin metal filmsPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 13 2005Annemarie Pucci Abstract Metal films with thickness in the nanometer range are optically transparent. With IR transmittance spectroscopy the in-plane film conductivity with its correlation to the film-growth process can be studied without electrical contacts and, on metal-island films, adsorbate vibrations can be observed because of surface enhanced IR absorption (SEIRA). Their analysis enables insight into the adsorbate-metal bonding and therefore gives information on the available adsorption sites and the crystalline facets correlated to. As in IR reflection absorption spectra dipole,dipole interaction of molecules on different sites modifies the vibration lines according to the degree of disorder ("atomic roughness"). Depending on that roughness IR spectra of adsorbate vibrations may be further modified because of their interaction with electronic excitations of the film. So, the limited facet size on cold-condensed metal films leads to additional IR activity: Raman lines of certain centrosymmetric adsorbate molecules (C2H4) are observed. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Structural and spectroscopic study of the Fe doped TiO2 thin films for applications in photocatalysisPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue S1 2009N. R. Mathews Abstract In this work we are presenting the results of structural and optical investigations of TiO2 and Fe doped TiO2 films using XRD, XPS, UV-VIS transmittance spectroscopy, and the application of these films in photocatalysis is demonstrated. Fe-doped TiO2 films were prepared by sol-gel method. The concentration of Fe utilized for doping ranged from 0.5 to 4% by atomic weight. For lower concentrations of Fe the transformation from amorphous-to-polycrystalline occurred at 400 °C. However, as the Fe concentration was increased to 4% this transformation occurred only after annealing at 600 °C. The average grain size for 4% Fe doped sample was in the range of 13 nm. In the case of pure TiO2 the XPS analysis showed only the presence of Ti 4+, where the 4% Fe doped film showed the presence of two species of Ti atoms; one of unperturbed Ti atoms and another of negatively charged surface of Ti atoms due to the interaction with Fe atoms in the anatase lattice of TiO2. The optical band gap was found to decrease with Fe concentration. The resistivity was found to decrease by one order after doping. The 4% Fe doped TiO2 films showed an increased photocatalytic activity. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | ||||||||||