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Spin Resonance Spectra (spin + resonance_spectrum)
Selected AbstractsSearch for highly resolved electron spin resonance spectra of the transient radical in radical polymerizationJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 3 2002Mikiharu Kamachi Abstract The detection of highly resolved spectra in electron spin resonance (ESR) measurements of radical polymerization is presented. Well-resolved ESR spectra of the propagating radical were detected in the radical polymerization of several vinyl monomers with a specially designed cavity and cell. More highly resolved ESR spectra of the propagating radicals of vinyl and diene compounds were observed with aconventional spectrometer without the specially designed cavity and cell. On the basis of the ESR spectra, propagation rate constants and dynamic behavior of propagating radicals are discussed. Moreover, the application of time-resolved ESR spectroscopy to research on the initiation process in radical polymerization is shown. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 269,285, 2002 [source] Identification of intrinsic defects in SiC: Towards an understanding of defect aggregates by combining theoretical and experimental approachesPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 7 2008Michel Bockstedte Abstract In SiC, mobile point defects may form thermally stable clusters and aggregates, such as di-vacancies or carbon interstitial complexes. Although predicted by theory, experimental evidence of such clusters became available only recently. Combining theoretical and experimental approaches, the unique identification of the di-vacancy, the carbon vacancy-antisite complex with the spin resonance centers P6/P7 and SI5 was recently achieved. In this way also the di-carbon and tri-carbon antisites with the photoluminiscence centers P,T and U, HT3 and HT4, respectively were identified. The two identified vacancy complexes show distinct properties: while the di-vacancy, like the silicon vacancy possesses a high-spin ground state, the carbon vacancy,antisite complex, like the carbon vacancy, is a Jahn,Teller center. These effects consistently explain the complex properties of the spin resonance spectra and are discussed in detail for the isolated vacancies. The aggregation of vacancies proved to be relevant in the explantation of the kinetic deactivation of nitrogen in co-implanted SiC. This and further evidence for defect aggregates underline the relevance of this notion. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Fullerene-functionalized polycarbonate: Synthesis under microwave irradiation and nonlinear optical propertyPOLYMER ENGINEERING & SCIENCE, Issue 4 2006Huixia Wu Fullerenation of polycarbonate (PC), a commercially important optical polymer, was achieved by direct reaction of C60 and PC in the presence of azo-bis-isobutyronitrile (AIBN), using 1,1,2,2-tetrachloroethane as the solvent under microwave irradiation (MI). Compared with conventional heating process, MI could significantly enhance the rate of the fullerenation under identical reaction conditions. The C60 content of the fullerene-functionalized polycarbonate (C60 -PC) could be controlled via varying the C60/PC feed ratio and the reaction time. The C60 -PCs are soluble in common organic solvents such as THF and chloroform. The products were characterized by gel permeation chromatography, UV,vis, FTIR, TGA, DSC, 1H NMR, and 13C NMR. The reaction of C60 with PC under MI was monitored by electron spin resonance spectra, the fullerene radicals were detected in reaction solutions and also in the solid product polymers, indicating the radical mechanism of the reaction. The nonlinear optical property of C60 -PCs in THF was investigated by the open-aperture z -scan technique at 527 nm, and its nonlinear absorption coefficient was found to be in the same order as that of C60. POLYM. ENG. SCI., 46:399,405, 2006. © 2006 Society of Plastics Engineers [source] Effect of Electrolyzed Water on Wound HealingARTIFICIAL ORGANS, Issue 12 2000Naoki Yahagi Abstract: Electrolyzed water accelerated the healing of full-thickness cutaneous wounds in rats, but only anode chamber water (acid pH or neutralized) was effective. Hypochlorous acid (HOCl), also produced by electrolysis, was ineffective, suggesting that these types of electrolyzed water enhance wound healing by a mechanism unrelated to the well-known antibacterial action of HOCl. One possibility is that reactive oxygen species, shown to be electron spin resonance spectra present in anode chamber water, might trigger early wound healing through fibroblast migration and proliferation. [source] | ||||||||||