nx_arrhenius.nx

nx_arrhenius.nx -- Arrhenius rate-vs-temperature primitive. license_tier: PUBLIC_DOMAIN_PHYSICS genealogy_id: arrhenius_1889_aktivieringsenergi + van_hoff_1884_kinetics + ellis_roberts_1980_seed_viability_eq_uses_arrhenius_form + nishi_q10_fixed_point_substrate_2026 The canonical chemical-kinetics + biological-rate primitive. ⚠INTENDED consumers, NOT current ones. This header used to read "Used by:" and list the four lanes below. As of 2026-07-25 NOTHING in the tree imports this file except its own cross-check gate -- the list was a design intent that read like an inventory of live dependents, which is how a dead primitive keeps looking load-bearing. Corrected to say what is true: - Seed viability decay (Ellis-Roberts 1980 σ-equation) [planned] - Soil microbial respiration rate (Lloyd & Taylor 1994) [planned] - Indoor-greenhouse climate-effect modeling (greenhouse plant growth rates per Q10 biological rule of thumb) [planned] - Reservoir nutrient solution chemistry kinetics [planned] - Any temperature-dependent rate the substrate needs to model The zero-consumer state is also why the reciprocal-precision defect fixed below survived: nothing called it, so nothing noticed it always returned "temperature has no effect". A primitive with no gate AND no callers is not a capability, it is an unverified intention. ===== The equation =============================================== k(T) = A * exp(-Ea / (R * T)) where: k(T) = rate constant at absolute temperature T A = pre-exponential factor (frequency factor) Ea = activation energy [J / mol] R = universal gas constant = 8.314 J/(mol*K) T = absolute temperature [Kelvin] In practice the substrate cares about RATE RATIOS more than absolute rate constants: