Modeling multicompartments

FIRAC is a computer code designed to estimate radioactive and chemical source-terms as.sociaied with a fire and predict fire-induced flows and thermal and material transport within facilities, especially transport through a ventilation system. It includes a fire compartment module based on the FIRIN computer code, which calculates fuel mass loss rates and energy generation rates within the fire compartment. A second fire module, FIRAC2, based on the CFAST computer code, is in the code to model fire growth and smoke transport in multicompartment stmetures. 

Fig. 39.2. Multicompartment model which, in addition to Fig. 39.1, takes into account that the drug is buffered in adipose (fatty) tissue, excreted by the kidneys and metabolized in the liver.

Sontag W. 1986. Multicompartment kinetic models for the metabolism of americium, plutonium and uranium in rats. Hum Toxicol 5 163-173. 

On some occasions, the body does not behave as a single homogeneous compartment, and multicompartment pharmacokinetics are required to describe the time course of drug concentrations. In other instances certain pharmacokinetic processes may not obey first-order kinetics and saturable or nonlinear models may be required. Additionally, advanced pharmacokinetic analyses require the use of various computer programs, such as those listed on the website http //www.boomer.org/pkin/soft.html. 

Marcus AH. 1985a. Multicompartment kinetic models for lead I. Bone diffusion models for long-term retention. Environ Res 36 442-458. 

Marcus AH. 1985b. Multicompartment kinetic models for lead II. Linear kinetics and variable absorption in humans without excessive lead exposure. Environ Res 36 459-472. 

Marcus AH. 1985c. Multicompartment kinetic models for lead III. Lead in blood plasma and erythrocytes. Environ Res 36 473-489. 

Refinement and Application of a Global Multicompartment Chemistry-Transport Model... 

The research published in this book uses the presently most comprehensive multicompartment model, the first which comprises a coupled atmosphere-ocean general circulation model (GCM). GCMs are the state-of-the-art tools used in climate research. The study is on the marine and total environmental distribution and fate of two chemicals, an obsolete pesticide (DDT) and an emerging contaminant (perflu-orinated compound) and contains the first description of a whole historic cycle of an anthropogenic substance, i.e. from the introduction into the environment until its fading beyond phase-out. 

Leip A, Lammel G (2004) Indicators for persistence and long-range transport potential as derived from multicompartment chemistrytransport modelling. Environ Poll 128 205-221 Lin SJ, Rood RB (1996) Multidimensional flux form semi-Lagrangian transport. Mon Wea Rev 124 2046-2068... 

Semeena VS, Lammel G (2003) Effects of various scenarios of entry of DDT and y-HCH on the global environmental fate as predicted by a multicompartment chemistry-transport model. Fresenius Environmental Bulletin 12 925-939... 

PHYSICAL ORGANIC CHEMISTRY NOMENCLATURE Multicompartment modeling, PHARMACOKINETICS Multicyclic enzyme systems,... 

Hughes MA, Glass PS, Jacobs JR. Context-sensitive half-time in multicompartment pharmacokinetic models for intravenous anesthetic drugs. Anesthesiology 1992 76 334—41. 

The final surfactant structures we consider as models for biological membranes are vesicles. These are spherical or ellipsoidal particles formed by enclosing a volume of aqueous solution in a surfactant bilayer. When phospholipids are the surfactant, these are also known as liposomes, as we have already seen in Vignette 1.3 in Chapter 1. Vesicles may be formed from synthetic surfactants as well. Depending on the conditions of preparation, vesicle diameters may range from 20 nm to 10 pirn, and they may contain one or more enclosed compartments. A multicompartment vesicle has an onionlike structure with concentric bilayer surfaces enclosing smaller vesicles in larger aqueous compartments. 

For persistent lipid-soluble compounds, conversion of blood or adipose tissue biomonitoring results to body burden and intake dose is feasible even with simple one-compartment models, although multicompartment physiologic models can provide a more flexible and improved tool for estimating dose. 

It can be shown, of course, that Eq. (10) is identical to Eq. (5) in the n-compart-ment model, but the use of Eq. (10) requires fewer assumptions to be made in determining Vss. That is, Eq. (10) only requires that disposition rates are first order, while Eq. (5) requires additional assumptions related to the underlying multicompartment pharmacokinetic model. 

Andersen ME, Bimbaum LS, Barton HA, et al. 1997b. Regional hepatic CYP1A1 and CYP1A2 induction with 2,3,7,8-tetrachlorodibenzo-p-dioxin evaluated with a multicompartment geometric model of hepatic zonation. Toxicol Appl Pharmacol 144 145-155. 

Andersen ME, Eklund CR, Mills JJ, et al. 1997a. A multicompartment geometric model of the liver in relation to regional induction of cytochrome P450s. Toxicol Appl Pharmacol 144 135-144. 

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