An application of HPLC and ion chromatography to study intramolecular charge transfer in polyhalogenated systems

Reaction of hydrated electrons with aromatics substituted with both bromine and chlorine results in the production of significant yields of chloride ion and the complementary bromine substituted phenyl radical. The total yields show that in all cases the reduction is essentially quantitative. For the dihalogenated benzenes and phenols the relative yields for C-Br and C-Cl bond rupture (0.86:0.14) reflect the relative rates for electron attachment at the Br and Cl positions, suggesting that there is little intramolecular charge transfer on the time scale of dissociation of the initial anion. In the case of dihalogenated benzoates about 40% of the reduction results in C-Cl bond rupture. In this case the added charge initially localized on the carboxyl group is transferred preferentially to the chlorine atom indicating that solvation of the intermediate radical anion must play an extremely important role in controlling the overall reduction process.     

Surface roughness and slope measurements using polarimetric SARdata

In this paper, the circular polarization coherence, ρ_RRLL , is investigated as a potential estimator of terrain surface roughness and small-scale slopes. The studies utilize microwave backscatter collected from 1) dielectric surfaces in an anechoic chamber and 2) a desert test site using P-, L-, and C-band NASA/JPL AIRSAR data. These experimental studies and supporting theory, indicate a sensitive decrease of |ρ_RRLL| with increasing surface roughness ks over a range 0 ⩽ ks ⩽ 1. For the present studies this decrease is caused largely by the depolarizing effects of small-scale surface slopes in the azimuth direction rather than by volume, or multiple scatter. For cases when the scatter is reflection symmetric, the value of |ρ_RRLL| depends on the surface roughness and on the local incidence angle. The dependence of |ρ_PRRLL| on the local incidence angle is supported by theory and experimental results. For these same scattering cases, however, |ρ_PRRLL| is independent of the surface dielectric constant. Estimation of the functional dependency of |ρ_PRRLL| versus ks, for a mid-range incidence angle, has been carried out using roughness estimates derived from an empirical model     

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Cross impact analysis of technological innovation and developmentin the softwood lumber industry in Canada: a structural modelingapproach

The potential of processing and product innovations to alleviate the problem of declining quality of logs facing the Canadian softwood industry is examined. Comparative forecasts were made of the consequences of three technological investment strategies: continuation of present levels, increased investment in processing R&D, and increased investment in product R&D. The study identified a mixed strategy of investment in both processing and product technologies as the best approach for the Canadian softwood lumber industry to maintain profitability and market share in the markets in which it competes with US producers     

Heavy quarkonium effective theory

We formulate a QCD-based effective theory approach to heavy quarkonia-like systems as $\bar cc$ and $\bar bb$ resonances andB _c states. We apply the method to inclusive decays, working out a few examples in detail.     

Influence of the Layer Morphology on the Electrical Properties of Sol Gel Transparent Conducting Oxide Coatings

Tranparent conducting coatings have been prepared by sol gel methods either by a conventional sol-gel process (Antimony doped Tin Oxide—ATO, Aluminium doped Zinc Oxide—AZO) or a new wet chemical process using fully dispersed crystalline nanoparticles (ATO, Indium Tin Oxide—ITO). The dip coating technique has been used as deposition technique with single coating thickness varying from a few nanometer to ca. 400 nm. The layers have been fired in a furnace. Structural properties have been determined by x-ray diffraction and TEM analysis and the electrical properties by the van der Pauw/Hall measurement. Three different coating procedures have been used to investigate the effect on the structure, morphology and the electrical properties of the coatings. It is shown that the individual layer thickness in multilayer coatings influences dramatically the mentioned properties. Very thin individual layers favour a heterogeneous nucleation with dense columnar growth of the crystallites leading to low electrical resistivity ( 10^–3 cm), while thick individual layers result in a porous morphology made of small crystallites leading to resistivities in the 10^–2 cm range.