Composed-Model

Comprehensive composed model combining all single-particle aerosol dynamics equations. Migrated from Aerosol.jl@c8c640bb src/single_particle_dynamics.jl:440 (`SingleParticleDynamics` @component). Composes MeanFreePath, SlipCorrection, and SettlingVelocity as coupled subsystems, then adds the Brownian diffusion and related properties inline. Covers Seinfeld & Pandis (2006), Chapter 9, Eqs. 9.6, 9.1, 9.34, 9.38, 9.42, 9.73, 9.78, 9.87, 9.88, 9.112.

Aggregate container for the 19 solid-phase salt species in the ISORROPIA II inorganic thermodynamic equilibrium model. Composes 19 named Solid instances — one per solid salt that can form in the K⁺-Ca²⁺-Mg²⁺-NH₄⁺-Na⁺-SO₄²⁻-NO₃⁻-Cl⁻-H₂O system — into a single subsystem bundle. Each Solid carries a single state variable M(t) [mol/m³] representing the molarity of that salt in air; in isolation M is conserved (D(M)/dt = 0). Source/sink terms are injected through the coupling mechanism when Solids is composed into the parent Isorropia system. Reference: Fountoukis and Nenes (2007), ISORROPIA II.