Physical Transformation AtlasPTA
Pathway · p-3b0e0f2431 · extends a recorded pathway

Chemical potential difference → Electrical work

Chemical potential differenceCombustionTemperature gradientThermionic emissionCharge carriersElectrical work

Epistemic state of the route

known constituent relations
5 / 5 established or replicated · weakest constituent established
constituent maturity floor
K4 · experimentally observed
search for this exact route
Not assessed — complete composition not searched.
recorded-pathway overlap
shares its closing relations with Thermionic converter · 3/5 relations shared
route-level evidence
0 sources for the complete composition · 4 cited by the constituent steps
boundaries and interfaces
BOUNDARY compatible · no region transition

Explorematrix context · physics checks · steps · route evidence · constituent evidence · cite

Matrix context

D = disequilibrium row · C = coupling family column. A cell reads the state of the atlas for that pair.

D.05 × C.29 · Chemical potential difference × Thermochemicalfamily: ThermochemicalD.05 × C.02 · Chemical potential difference × Thermionicfamily: Thermionic

Typed bounds on this route

Every limit the atlas holds for this route, as constraint records: reached through bounded_by claims on the route's own entities. Hard bounds (an upper bound or a formula) decide the thermodynamic-bound check above; benchmarks, constitutive relations and resource limits are listed and never decisive. No prose limit exists anywhere (pass 42).

  • Carnot limit · formula-bound · hard, applies to this route
    η ≤ 1 − T_c/T_h for any heat engine between reservoirs at T_h and T_c
  • Space-charge limit · formula-bound · hard, applies to this route
    J ≤ (4ε₀/9)√(2e/m) V^{3/2}/d² (Child–Langmuir)

Steps

  1. 01
    chemical → thermal · loss to radiative
    • fuel, oxidiser and an ignition source; flame temperature 1500–2500 K
    gas · above ~700 K
    refs [1]
  2. 02
    thermal → thermal
    refs [1]
  3. 03
    thermal → electrical · loss to radiative
    • cathode hot enough that kT is a useful fraction of the work function (typically > 1500 K for metals, lower for low-work-function coatings)
    • a cooler anode across a vacuum or caesium-vapour gap
    vacuum required · above ~700 K · solid
    refs [2] [3]
  4. 04
    electrical → electrical · loss to thermal
    • emitted electrons collected at the anode at a potential difference set by the work-function difference
    refs [3]
  5. 05
    Charge carriers —converts into→ Electrical workestablishedclaim record
    electrical → electrical · loss to thermal
    • carriers driven through an external load at the potential difference the source maintains
    refs [4]

Evidence for the complete composition · 0

No source on record for this exact composition. The sources below support the individual steps, not the route as a whole.

Evidence for the constituent relations · 4

  1. [1]
    A. Bejan. Advanced Engineering Thermodynamics (4th ed.) (2016)
    Wiley · doi:10.1002/9781119245964 · crossref ✓ 2026-09-19 · record
  2. [2]
    O. W. Richardson. On the negative radiation from hot platinum (1901)
    Proceedings of the Cambridge Philosophical Society 11, 286–295 · paper, no DOI · record
  3. [3]
    G. N. Hatsopoulos, E. P. Gyftopoulos. Thermionic Energy Conversion, Vol. 1: Processes and Devices (1973)
    MIT Press · book, no DOI · record
  4. [4]
    N. W. Ashcroft, N. D. Mermin. Solid State Physics (1976)
    Holt, Rinehart and Winston · book, no DOI · record

Cite this route

Physical Transformation Atlas (2026). route p-3b0e0f2431: Chemical potential difference → Combustion → Temperature gradient → Thermionic emission → Charge carriers → Electrical work. Dataset revision rbfbfcbb70e57 (hash of the canonical data). https://physical-transformation-atlas.wldud5192.workers.dev/path/3b0e0f2431

Ids and matrix addresses are stable across revisions; the revision hash identifies the exact canonical files the record was compiled from and is meta.data_hash in every /api export. Reuse terms: see the license field in any export.