AbslraclRigorous bounds on temperature and concentration are obtained for a model reacting system incorporating spatial variation, reactant consumption, and Arrhenius kinetics. Similar bounds are obtained for the Semenov (spatially uniform) approximation. Temperatures predicted by the FrankKamenetskii (stationaryl approximation are shown to be upper bounds on the temperature of the complete tim...

were studied in a quasi-static reaction cell in the temperature range 293 ≤ T/K ≤ 501 at a pressure of 10 mbar and 20 mbar, respectively, with He as the main carrier gas. The electronically excited reactant NH(a) was generated by laser-flash photolysis of HN3, at λ= 308 nm and detected by laser-induced fluorescence (LIF). Also the ground state species NH(X) was detected by LIF. From the measure...

A semi-linear reduced-order state estimator is presented to reconstruct approximately the state variable initially unknown of a class of nonlinear tubular reactors models, namely the exothermal plug-flow tubular reactor involving sequential reactions for which the kinetics depends on both the temperature and the reactant concentration. Our conception is based on bounded observations and the ana...

An axial dispersion reactor model for gas–liquid reaction systems is proposed in this paper based on the penetration theory. The mass transfer mechanism accompanied by a chemical irreversible first-order reaction is mathematically treated in a new way in order to use its results to develop the model conveniently. Analytical solutions can be obtained for the equation system involving linear diff...

In this study, we have performed nanoscale characterization of Si-clusters and Si-nanowires with a laser-assisted tomographic atom probe. Intrinsic and p-type silicon nanowires (SiNWs) are elaborated by chemical vapor deposition method using gold as catalyst, silane as silicon precursor, and diborane as dopant reactant. The concentration and distribution of impurity (gold) and dopant (boron) in...

Silver nanoparticles were synthesized in reverse micelles consisting of sucrose fatty acid esters by dissolving reactant powder in the water pool of reverse micelles through the solid-liquid extraction. Silver nanoparticles having various sizes and shapes were obtained at high concentration. The size of silver nanoparticles was controlled by reaction temperature. Moreover, the size of silver na...

In this paper we analyze a planar model for a molten carbonate electrode of a fuel cell. The model consists of two coupled second-order ordinary diierential equations, one for the concentration of the reactant gas and one for the potential. Restricting ourselves to the case of a positive reaction order in the Butler-Volmer equation, we consider existence, uniqueness, various monotonicity proper...

Microwave-assisted hydrothermal synthesis was used to grow LiMnPO4 micro- and nanocrystals from acetate precursors. By appropriate adjustment of the precursor concentration and the pH-value of the reactant, the product composition and purity along with the crystal size can be manipulated, resulting in particle-dimensions from around 10 μm down to a few 100 nm. Prisms and plates with hexagonal b...

We describe a one-step, labeled-antibody radioassay for measuring free thyroxin (FT4) in serum or plasma, based on a novel principle. FT4 in the sample competes with a gross molar excess (over antibody) of a cross-reactant (L-triiodothyronine, T3), chemically coupled to magnetizable polymer particles, for binding to avid 125l-labeled monoclonal anti-thyroxin antibodies. As in conventional immun...

Photoionization methods have been used to study the reactions of the molecular ion in vinyl fluoride to yield the ionic products C3H 3F{, C3H 4F+, and C3Ht. Quantitative measurements are reported of the effect of the vibrational state of the reactant ion on the product distribution and overall reaction cross section. Reaction cross sections for all three channels decrease with reactant internal...