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The plot for vapor is a transformation of data Synthetic spectrum for gas mixture ' Pure H 2 O ' (296K, 1 atm) retrieved from Hitran on the Web Information System. [6] Liquid water absorption spectrum across a wide wavelength range [missing source] The absorption of electromagnetic radiation by water depends on the state of the water.
The absorbance of some of the molecular structures shown in the spectrum: Total water at 3450cm-1, molecular water at 1630cm-1, carbon dioxide at 2350cm-1 and carbonate molecule at 1430cm-1. The most commonly investigated volatiles are water and carbon dioxide as they are the primary volatiles to drive volcanic and magmatic processes. [4]
Fourier transform infrared spectroscopy (FTIR) [1] is a technique used to obtain an infrared spectrum of absorption or emission of a solid, liquid, or gas. An FTIR spectrometer simultaneously collects high-resolution spectral data over a wide spectral range.
The infrared portion of the electromagnetic spectrum is usually divided into three regions; the near-, mid- and far-infrared, named for their relation to the visible spectrum. The higher-energy near-IR, approximately 14,000–4,000 cm −1 (0.7–2.5 μm wavelength) can excite overtone or combination modes of molecular vibrations .
cis-1,2-disub. alkenes 1660 medium trans-1,2-disub. alkenes 1675 medium trisub., tetrasub. alkenes 1670 weak conjugated C═C dienes 1600 strong 1650 strong with benzene ring 1625 strong with C═O 1600 strong C═C (both sp 2) any 1640–1680 medium aromatic C═C any 1450 weak to strong (usually 3 or 4) 1500 1580 1600 C≡C terminal alkynes
Two-dimensional infrared spectroscopy (2D IR) is a nonlinear infrared spectroscopy technique that has the ability to correlate vibrational modes in condensed-phase systems. This technique provides information beyond linear infrared spectra, by spreading the vibrational information along multiple axes, yielding a frequency correlation spectrum.
The UV-B flux is 2–4 times greater during the middle 4–6 hours of the day, and is not significantly absorbed by cloud cover or up to a meter of water. [ 47 ] Ultraviolet light, specifically UV-B, has been shown to cause cataracts and there is some evidence that sunglasses worn at an early age can slow its development in later life. [ 18 ]
A fragmented part of the 'window' spectrum (one might say a louvred part of the 'window') can also be seen in the visible to mid-wavelength infrared between 0.2 and 5.5 μm. The infrared atmospheric window is an atmospheric window in the infrared spectrum where there is relatively little absorption of terrestrial thermal radiation by ...