What is coloration efficiency?

The coloration efficiency (CE), defined as the change in optical density per injected charge density at a particular wavelength, can be a strong predictor of electrochemical stability and speed.

What is four-color& five color problem?

Precise formulation of the theorem If we wanted those regions to receive the same color, then five colors would be required, since the two A regions together are adjacent to four other regions, each of which is adjacent to all the others.

What is four-color problem in graph theory?

The four-color theorem states that any map in a plane can be colored using four-colors in such a way that regions sharing a common boundary (other than a single point) do not share the same color. This problem is sometimes also called Guthrie’s problem after F. Guthrie, who first conjectured the theorem in 1852.

How many colors does a map need?

four colors
As mentioned above, the four-color theorem states that only four colors are needed to ensure adjacent regions have different colors — the point being to make sure that each is distinguishable from the other.

How is coloration efficiency calculated?

Using 95% of the total transmittance change at λmax as reference point, coloration efficiencies, η = ΔA(λmax)/Q, were calculated as 143 and 150 cm2 C−1 respectively for the PB/PW and PW/PB electrochromic transitions.

Who proved the five color theorem?

Percy John Heawood
The Five color theorem is a theorem from Graph theory. It states that any plane which is separated into regions, such as a map, can be colored with no more than five colors. It was first stated by Alfred Kempe in 1890, and proved by Percy John Heawood eleven years later.

How is the four color theorem used today?

One of the 4 Color Theorem most notable applications is in mobile phone masts. These masts all cover certain areas with some overlap meaning that they can’t all transmit on the same frequency. A simple method of ensuring that no two masts that overlap have the same frequency is to give them all a different frequency.