EFFECT OF CURLING IRONS 237 (a) 7.00E+05 6.00E+05 • 5.00E+05 •" 4.00E+05 ,g • 3.00E+05 *' 2.00E+05 1.00E+05 O. OOE+ O0 unexposed unexposed: 145o/14•s = 0.83 30 min: 145o/14•s = 0.91 i , 400 450 5OO 550 Wavelength (rim) (b) 1.00E+06 9.00E+05 8.00E+05 7.00E+05 6.00E+05 5.00E+05 4.00E+05 3.00E+05 2.00E+05 1.00E+05 O.00E+00 330 30 min•.• .............................. unexposed: 145o/14•s = 0.78 "•',, ,,'•' •• ••..,,. ,,.. ...... 30 min: 145d14•s = 0.81 __,,,,,,,,///// •unxpos-...........'...........'"'"".... i i i i 380 430 480 530 580 Wavelength (rim) (c) 2.00E+06 1.80E+06 A 1.60E+05 Q. 1.40E+06 ,-- 1.20E+06 • 1.00E+06 • 8.00E+05 ß - 6.00E+05 -- 4.00E+05 2.00E+05 O.00E+00 unexposed unexposed: 145o/14•5 = 0.84 ,,,,,. 30 min: 145dl4•0.87=min ..................................... 4...• 30 i i i i 360 410 460 510 560 Wavelength (nm) Figure 8. The emission spectra of Asian hair, at excitation wavelengths of 290 nm (a), 320 nm (b), and 350 nm (c), before thermal exposure and after 30 rain of treatment. Thermal treatment was administered at 164øC.

238 JOURNAL OF COSMETIC SCIENCE Bleached Hair Piedmont Hair White Hair Figure 9. Bleached, Piedmont, and white (unpigmented) hair after 30 rain (5-rain intervals) of thermal treatment at 164øC. Table II Hunter Colorimeter Data for Thermally Treated Hair AL • Ab AE AC AYI White -2.85 1.46 2.98 4.37 3.32 10.13 Piedmont -3.05 -+ 0.88 1.95 -+ 0.35 2.18 _+ 0.36 4.23 _+ 0.68 2.93 -+ 0.36 14.61 _+ 0.81 Bleached -6.41 _+ 2.32 0.04 _+ 1.00 0.88 _+ 0.64 6.47 _+ 2.30 0.88 _+ 0.64 7.55 + 2.06 Light-brown -0.82 _+ 0.08 -0.44 _+ 0.23 -0.25 _+ 0.14 0.96-+ 0.13 0.51 ñ 0.21 -2.38 _+ 2.25 Asian -0.48 _+ 0.11 -0.31 _+ 0.25 -0.15 _+ 0.10 0.59 -+ 0.16 0.34 _+ 0.23 -2.46_+ 2.02 COMBING ANALYSIS The quantification of combing measurements has been widely employed in the evalu- ation of hair care products (29-31). This technique is very sensitive to small changes in the chemical composition or physical modification of the hair surface that accompany