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Loss Spectra (loss + spectrum)
Selected AbstractsShort-Range Interactions in Na Coadsorption with CO and O on Ni(111)CHEMPHYSCHEM, Issue 8 2008Antonio Politano Dr. Abstract The coadsorption of Na with CO and O on Ni(111) is studied by high-resolution electron energy loss spectroscopy. Experimental evidence for a very short-range interaction between Na and coadsorbates is reported, in contrast with recent theoretical predictions overestimating nonlocal alkali-induced effects. Loss spectra show distinct features, as a consequence of different local [CO]:[Na] and [O]:[Na] stoichiometries. [source] Dielectric studies of molecular motions in amorphous solid and ultraviscous acetaminophenJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 10 2005G.P. Johari Abstract The dielectric permittivity and loss spectra of glassy and ultraviscous states of acetaminophen have been measured over the frequency range 10 Hz,0.4 MHz. The relaxation spectra show an asymmetric distribution of times expressed in terms of the Kohlrausch exponent, ,, which remains constant at 0.79,±,0.02 over the 305,341 K range. The dielectric relaxation time increases on cooling according to the Vogel,Fulcher,Tammann equation. However, the values of the parameters are considerably different from the values deduced from earlier work by other researchers using the heat capacity of ultraviscous acetaminophen and relating it to its molecular mobility. The calorimetric glass softening temperature of 296 K obtained from differential scanning calorimetry is close to the value measured from dielectric relaxation. The equilibrium permittivity of ultraviscous acetaminophen decreases on heating like that of a normal dipolar liquid, as anticipated from the Curie law. But, its value decreases rapidly with time when it begins to crystallize. The equilibrium permittivity of this crystal phase is ,3.1 at 300 K and increases with temperature, which indicates a partial, orientational-disordering of its structure. The results show limitations of the procedures used in the modeling of the kinetics of molecular motions, that is, estimating physical stability, using thermodynamic considerations based on thermal analyses of the amorphous solid phase of acetaminophen. © 2005 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 94:2207,2223, 2005 [source] Oxidation of dimers at the Si(100) surface studied by first-principles simulation of high-resolution EELSPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 8 2010Lucia Caramella Abstract Electron energy loss spectra of the Si(100) and Si(100):O surfaces are investigated using ab initio methods based on density functional theory. Computed spectra for the clean surface are found to be in good agreement with published experimental data, providing further confirmation that reconstructions of higher order than (2,×,1) are present on Si(100). The origins of the main spectral structures are analyzed and their relation to the surface bandstructure is illustrated. Oxygen adsorption on the surface dimers is found to cause strong modifications to the calculated spectra, thereby partially explaining the results of surface differential reflectivity experiments. [source] Damages Caps, Insurability, and the Performance of Medical Malpractice InsuranceJOURNAL OF RISK AND INSURANCE, Issue 1 2005W. Kip Viscusi This article uses the complete property-casualty insurance files of the National Association of Insurance Commissioners from 1984 to 1991 to assess the effect of medical malpractice reforms pertaining to damages levels and the degree to which these damages are insurable. Limits on noneconomic damages were most influential in affecting insurance market outcomes. Several punitive damages variables specifically affected the medical malpractice insurance market, including limits on punitive damage levels, prohibitions of the insurability of punitive damages, and prohibition of punitive damages awards. Estimates for insurance losses, premiums, and loss ratios indicate effects of reform in the expected directions, where the greatest constraining effects were for losses. The quantile regression analysis of losses indicates that punitive damages reforms and limits were most consequential for firms at the high end of the loss spectrum. Tort reforms also enhanced insurer profitability during this time period. [source] | ||||||||||