Components conservative/volatile

The method of zonation was applied to the energy and material conservation equations. Based on centered finite difTerence approximations, this method can transform three partial differential equations in radial distance and time to ordinary differential equations in time only. Following this, the ordinary differential equations were solved by using Crank-Nicholson algorithm. On the basis of this, the volumetric fluxes of those tar-phase and total volatile phase components were integrated with time by using in roved Euler method to evaluate overall pyrolysis product yields, and afterwards the gas yield can be deduced. 

Usually, flashpoint is measured in air. Open cup methods may overestimate the flashpoint for liquids containing multiple components because of the loss of more volatile components during testing. Nevertheless, open cup testers can provide flashpoint for situations of open vessels and spills. In contrasts, closed cup techniques prevent the loss of volatile components by keeping the sample enclosed until the ignition source is introduced, and therefore, closed cup data are more conservative than and generally preferred to open cup data. 

In the physical chemistry of solids [3,217,283-285], data on the chemical composition, i.e., the concentration expressed in mole fraction, A, = nfn, are most often used. If some components are part of the surroundings (partially of an open system), the components i can be divided into conservative and volatile ones. In most real cases, the studied system consists of several (at least two) phases j, denoted by exponents si, s2,. .. (solid phase) or 11, 12,. .. (liquid phase), etc.. Generalized function, thermodynamic potential, can be of practical use when the effect of external force fields is assumed. Although a thermophysical experiment involving all these variables is... 

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