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Results of combined experimental and theoretical investigations of elementary chemical reaction processes of CO-CO2 gas mixtures at nickel/yttria-stabilized zirconia (Ni/YSZ) solid oxide fuel cell (SOFC) model anode systems are presented. Temperature-programmed desorption and reaction measurements were performed in order to determine adsorption/desorption kinetic data as well as thermodynamic parameters for the CO/CO2/Ni and CO/CO2/yttria-stabilized zirconia (YSZ) heterogeneous reaction systems. From these data, an elementary kinetic reaction mechanism of the electrochemical CO oxidation at Ni/YSZ anodes was developed. Numerical simulations were performed for three different spillover mechanisms. Steady-state polarization curves and electrochemical impedance spectra were calculated, allowing for a direct comparison with experiments performed by Lauvstad et al. [J. Electrochem. Soc., 149, E506 (2002)]. Best agreement with the experimental data was obtained when assuming two consecutive charge-transfer steps from YSZ-O2- via YSZ-O- to Ni-O, the second step being accompanied by oxygen spillover over the three-phase boundary. [ABSTRACT FROM AUTHOR]

A novel temperature-imaging technique based on laser-induced fluorescence of nitric oxide is presented, analyzed and applied. Multi-line rotational thermometry is combined with an efficient spectra-fitting procedure in an imaging con- figuration. The technique is sensitive over a wide range of temperatures and robustly applicable to different steady combustion and flow systems. Application is shown in premixed and partially premixed ethylene/air Bunsen flames with equivalence ratios between 0.7 and 3.0, and the results are compared to coherent anti-Stokes Raman-scattering temperature measurements. The technique is robust against strong elastic scattering from soot in the rich flames. It yields absolute, quantitative temperature measurements without the necessity of external calibration. [ABSTRACT FROM AUTHOR]

The reactivity of 38 murine strains to a synthetic analogue of bacterial lipoprotein, tripalmitoyl-pentapeptide (TPP), was tested and compared with the reactivity to lipopolysaccharide (LPS). These strains include common laboratory mice and H-2 recombinant inbred lines, as well as some newly bred lines originating from animals recently captured in different regions of Europe. All animals analysed were reactive to TPP and polyclonally activated to proliferation and immunoglobulin synthesis. Large differences in mitogen reactivities of various H-2 recombinant inbred strains suggest that MHC or closely linked gene products influence the reactivity to the LPS and TPP mitogens. By analyzing the frequencies of precursor cells reactive to TPP or LPS and the isotype patterns obtained after stimulation, we demonstrated that both mitogens activate individual B cells in different ways. [ABSTRACT FROM AUTHOR]