EFFECT OF UV RADIATION ON HAIR STRUCTURE APPENDIX I Planck's equation: E= energy of one photon (J) h = Planck's constant (6.62 x 10-34 J s) v = frequency of radiation (s-1 also Hz) Also: A = wavelength of radiation (m) c = speed of light (3 x 108 m/ s) Therefore: Also: E=hv v = c/A E = (h c)/A energy per molecule E' = NA (h c)/A energy per mole Where NA is Avogadro's number (6.022 x 1023 mol-1) and E' is expressed in J mol- 1 The relationship between wavelength (nm) and E'(kJ mol'l) can be summarized: A (nm) = 11.96 104 / E' (kj/mol) N.B.: 1 cal = 4.184 joule Prefixes for units 1Q6 103 10-2 mega kilo (k) centi (c) Some conversion factors 10-3 10-6 lQ-9 milli (m) micro(µ) nano (n) 111 1 KJ cm-2 = 107 J m-2 1 J cm-2 = 104 J m-2 1 mW cm-2 = 10 W m-2 1 day = 86400 sec

112 APPENDIX II Term Wavelength Frequency Wavenumber Force Energy Power Radiant Energy Radiant exposure Radiant Power (Radiant energy per unit time ) Radiant exitance (Radiant power emitted per unit surface) Irradiance (Radiant power received per unit surface) Radiant intensity (Radiant power per unit of solid angle) Radiance (Radiant intensity per unit area) Spectral radiant power distribution Spectral irradiance distribution JOURNAL OF COSMETIC SCIENCE Symbol/s Units "A m V g-1 , Hz (hertz) m m-1 N (newton) kg m s-2 J (Joule) Nm W (watt) J s-1 J (joule), kg m2 s·2 Jm-2 Pe W (watt), J s-1, kg m-2 s-3 Me Wm-2 Ee Wm·2 le W sr-1 Le W m-2 sr-1 P., Wm-1 E., Wm·2 m-1 Luminous energy term (21) Light exposure Luminous flux Illuminance Luminous intensity Luminance Units lux s Im (lumen) lm m·2 (lux) cd (candela) cd m·2 Equation/ description V = c/A m = 1/ V Force = (mass) x (acceleration) Me = dP./dA1 where dA1 is the surface of the element of source E. = dP./dA2 where dA2 is the surface of the element receiver Le = dPe/steradian P., = dPe/dA E., = dE./dA Steradian is a unit of measure equal to the solid angle subtended at the center of a sphere by an area on the surface of the sphere that is equal to the radius squared. The total solid angle of a sphere is 4 7T steradians.