Its components are typically observed between 1590 and 1820 cm−1 or 3000 and 3400 cm−1, which are characteristic of OH vibrational stretching [31, 32].
Nevertheless, it is noted that the intensity of band around 3,379 cm−1, which is characteristic of –OH groups on the silica surface [16] was decreased with the increasing C2H4 decomposition temperature, especially at temperatures above 673 K.
The absorption bands in the 4000 1000 cm−1 range are characteristic of –OH, C=O, N H, and CH3 functional organic groups, while the region between 1000 and 400 cm−1 is the fingerprint of the inorganic material.
The band observed at 3386 cm-1 seems to be characteristic of OH groups present in lignin and carbohydrates.
The characteristics of the OH beam were probed using a 282 nm excitation laser beam crossing the gas expansion either about 5 cm downstream from the valve opening or 11.5 mm from the exit of the Stark decelerator.
The demographic and ocular characteristics of the OH patients and healthy controls are presented in Table 1.
The strong peak at 1,383 cm−1 in the BSA Cu2+, and BSA CuSe spectra is attribute to the absorption of NO3−1, which was introduced by the addition of Cu(NO3 2.Comparing the IR spectra of BSA CuSe with those of pure BSA, the characteristic peak of –OH groups shifts to a high wavenumber of about 5 cm−1, and the characteristic peak of –NH groups disappears.
The strong broad band ranging from 3200 to 3600 cm−1 usually corresponds to the possibility of overlapping between the –NH and the –OH stretching vibrations, and the strong sharp band at the wavenumber region of 3400 3550 cm−1 is characteristic of the –OH stretching vibration [ 24].
The spectrum of the T-MWCNTs shows two strong peaks in the ranges of 3200 3600 and 1600 1750 cm−1 that are characteristic of hydroxyl (–OH) and carboxyl (–COOH) functional groups, respectively [15, 17].
This band characteristic of stretching vibrations of OH groups in associated water molecules is asymmetrical and its high-frequency component has a clearly detectable shoulder at 3628 cm−1 (N-CLI) remainder after the acid treatment and caused by a bridge SiO(H Al group.
