Cottrell equation
E168996
The Cottrell equation is a fundamental relation in electrochemistry that describes how current decays over time during a diffusion-controlled potential step at an electrode.
All labels observed (1)
| Label | Occurrences |
|---|---|
| Cottrell equation canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T1479026 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Cottrell equation Context triple: [Alan Cottrell, knownFor, Cottrell equation]
-
A.
Smoluchowski coagulation equation
The Smoluchowski coagulation equation is a fundamental integro-differential equation in statistical physics that models how particles undergoing random collisions aggregate over time into larger clusters.
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B.
Darwin–Fowler method
The Darwin–Fowler method is a statistical mechanics technique that uses complex analysis and generating functions to derive distribution laws for systems of many particles.
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C.
Shockley diode equation
The Shockley diode equation is a fundamental formula in semiconductor physics that describes the current–voltage relationship of an ideal p–n junction diode.
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D.
Lorentz–Lorenz equation
The Lorentz–Lorenz equation is a fundamental relation in optics and electromagnetism that connects a material’s refractive index to its molecular polarizability and density.
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E.
Steinmetz’s law of hysteresis
Steinmetz’s law of hysteresis is an empirical formula that relates the energy loss in magnetic materials to the maximum magnetic flux density, widely used in electrical engineering to estimate core losses in transformers and other AC magnetic devices.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Cottrell equation Target entity description: The Cottrell equation is a fundamental relation in electrochemistry that describes how current decays over time during a diffusion-controlled potential step at an electrode.
-
A.
Smoluchowski coagulation equation
The Smoluchowski coagulation equation is a fundamental integro-differential equation in statistical physics that models how particles undergoing random collisions aggregate over time into larger clusters.
-
B.
Darwin–Fowler method
The Darwin–Fowler method is a statistical mechanics technique that uses complex analysis and generating functions to derive distribution laws for systems of many particles.
-
C.
Shockley diode equation
The Shockley diode equation is a fundamental formula in semiconductor physics that describes the current–voltage relationship of an ideal p–n junction diode.
-
D.
Lorentz–Lorenz equation
The Lorentz–Lorenz equation is a fundamental relation in optics and electromagnetism that connects a material’s refractive index to its molecular polarizability and density.
-
E.
Steinmetz’s law of hysteresis
Steinmetz’s law of hysteresis is an empirical formula that relates the energy loss in magnetic materials to the maximum magnetic flux density, widely used in electrical engineering to estimate core losses in transformers and other AC magnetic devices.
- F. None of above. chosen
Statements (45)
| Predicate | Object |
|---|---|
| instanceOf |
electrochemical equation
ⓘ
mathematical model ⓘ |
| appearsIn | textbooks on electrochemical methods ⓘ |
| appliesTo |
diffusion-controlled processes
ⓘ
planar electrodes ⓘ |
| assumes |
constant diffusion coefficient
ⓘ
initially uniform bulk concentration ⓘ instantaneous potential step ⓘ no convection ⓘ no migration (supporting electrolyte present) ⓘ semi-infinite linear diffusion ⓘ |
| category |
chronoamperometry
ⓘ
transient electrochemical response ⓘ |
| contrastsWith | steady-state current equations ⓘ |
| derivedFrom | solution of Fick's second law for a potential step ⓘ |
| describes |
current–time relationship at an electrode
ⓘ
diffusion-controlled potential step ⓘ |
| field | electrochemistry ⓘ |
| includesParameter |
A (electrode area)
ⓘ
C (bulk concentration) ⓘ D (diffusion coefficient) ⓘ F (Faraday constant) ⓘ n (number of electrons) ⓘ t (time) ⓘ |
| influences | design of electrochemical experiments ⓘ |
| mathematicalForm | i(t) = n F A C \sqrt{D / (\pi t)} ⓘ |
| namedAfter | Frederick Gardner Cottrell ⓘ |
| relatedConcept |
Randles–Ševčík equation
ⓘ
chronoamperometric response at microelectrodes ⓘ |
| relatedTo |
Fick's first law of diffusion
ⓘ
surface form:
Fick's second law of diffusion
|
| relates |
current to bulk concentration
ⓘ
current to diffusion coefficient ⓘ current to electrode area ⓘ current to number of electrons transferred ⓘ faradaic current to time ⓘ |
| shows |
current decays with t^{-1/2}
ⓘ
current decreases over time after a potential step ⓘ |
| taughtIn | advanced electrochemistry courses ⓘ |
| usedFor |
analyzing chronoamperometry data
ⓘ
determining concentrations of electroactive species ⓘ determining diffusion coefficients ⓘ |
| usedIn |
fundamental electrochemical kinetics studies
ⓘ
transient electrochemical techniques ⓘ |
| validWhen |
electrode reaction is fast (reversible)
ⓘ
reaction is purely diffusion-controlled ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Cottrell equation Description of subject: The Cottrell equation is a fundamental relation in electrochemistry that describes how current decays over time during a diffusion-controlled potential step at an electrode.
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.