The global nth order rate equation has been criticized for lack of theoretical basis and has been shown to be inadequate for modeling char oxidation rates as a function of total gas pressure. The simple Langmuir rate equation is believed to have more potential for modeling high pressure char oxidation. The intrinsic Langmuir rate equation is applied to graphite flake oxidation data and agrees w...

Introduction The reactivity behavior of chars and carbons under reaction with oxygen agents has been the focus of many studies due to its practical applications in industry. Characterization of the oxygen complexes in the char surface is very important because its relation with mechanism of gasification and combustion reactions. Studies using transient kinetic have shown that in the char-CO2 an...

Let V be a vector bundle of constant rank n ≥ 1 over a scheme S, and let q : V → L be a quadratic form valued in a line bundle L, so we get a symmetric bilinear form Bq : V × V → L defined by Bq(x, y) = q(x+ y)− q(x)− q(y). Assume q is fiberwise non-zero over S, so (q = 0) ⊂ P(V ∗) is an S-flat hypersurface with fibers of dimension n − 2 (understood to be empty when n = 1). By HW2, Exercise 4 (...

Poultry manure (PM) chars were obtained at different temperatures and charring times. Chemical-physical characterization of the different PM chars was conducted by cross-polarization magic angle spinning (CPMAS) (13)C NMR spectroscopy and thermal analysis. CPMAS (13)C NMR spectra showed that the chemical composition of PM char is dependent on production temperature rather than on production dur...

Understanding the extent of interspecific hybridization and how ecological segregation may influence hybridization requires comprehensively sampling different habitats over a range of life history stages. Arctic char (Salvelinus alpinus) and Dolly Varden (S. malma) are recently diverged salmonid fishes that come into contact in several areas of the North Pacific where they occasionally hybridiz...

Charcoals prepared from certain tropical woods contain stable paramagnetic centers, and these have been characterized by EPR spectroscopy in the absence and presence of oxygen. The EPR-detectable spin density has been determined, as has been the temperature- and frequency-dependence of the oxygen broadening of the EPR signal, which is orders of magnitude larger than that observed with other mat...

The model has been developed by considering two distinct zones in the downdraft gasifier: pyro-oxidation zone and reduction zone. The process in the pyro-oxidation zone has been solved based on the chemical equilibrium consideration considering water gas shift reaction and methanation reaction. The composition of different species (H2, CO, CO2, CH4, H2O, N2 and Char) and the temperature of the ...

The thermal reactivity and kinetics of five coal chars, a biomass char, and two coal/biomass char blends in an oxy-fuel combustion atmosphere (30%O2-70%CO2) were studied using the non-isothermal thermogravimetric method at three heating rates. Fuel chars were obtained by devolatilization in an entrained flow reactor at 1273 K under N2 and CO2 atmospheres.Three nth-order representative gas-solid...