Contents 4 Interest Rate Modeling

For many years test chambers and cells belong to the most important tools for the simulation of indoor related conditions and for the evaluation of emission rates. It can be assumed that their application will become even more important in the near future. Moreover, powerful kinetic models are now available that help to understand emission characteristics of sources. The current trend to develop devices en miniature brings us to the borderline between emission and content analysis. It will be interesting to see new chamber designs and intelligent applications for indoor related studies. 

We will later recognize this as the kernel for the continuum linear diffusion equation once we make the observation that the jump rate and the diffusion constant are related by Z) = Fa. For now we content ourselves by noting that the model of diffusion put forth here is invested with relatively little complexity. All we postulated was the uncorrelated hopping of the particles of interest. Despite the simplicity of the model, we have been led to relatively sophisticated predictions for what one might call the kinematics (which is statistical) of the diffusion field that results once the diffusive process has been set in motion. Indeed, the spreading... 

The model accounts for the dramatic change in oil production rate which is observed. The fast initial rate is governed by the rate constant k (first order in kerogen content). The latter slow rate is governed by the sum of the two bitumen reactions, which are assumed first order in the intraparticle bitumen content and have rate constants k2 and kc At the temperatures of interest, k is much greater than k2 + kc so that the first step of the reaction goes virtually to completion before there is any appreciable conversion of the bitumen. 

FIGURE 22.9 Four-compartment model of the atmosphere (NH = Northern Hemisphere, SH = Southern Hemisphere, S = stratosphere, T = troposphere). PNH and Psh are source emission rates of the compound in the NH and SH troposphere, respectively. The quantities of the species of interest in the four reservoirs are denoted 2nh> G h siii anc 2 sH- The fluxes between the reservoirs are proportional to the content of the compound in the reservoir where the flux originates. The flux of material from the NH troposphere to the SH troposphere is nh/sii2nh ar d the reverse flux is A H/nhG h- Other intercompartmental fluxes are defined similarly. 

---