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  2. Near-infrared spectroscopy - Wikipedia

    en.wikipedia.org/wiki/Near-infrared_spectroscopy

    Many commercial instruments for UV/vis spectroscopy are capable of recording spectra in the NIR range (to perhaps ~900 nm). In the same way, the range of some mid-IR instruments may extend into the NIR. In these instruments, the detector used for the NIR wavelengths is often the same detector used for the instrument's "main" range of interest.

  3. Arrhenius equation - Wikipedia

    en.wikipedia.org/wiki/Arrhenius_equation

    In physical chemistry, the Arrhenius equation is a formula for the temperature dependence of reaction rates.The equation was proposed by Svante Arrhenius in 1889, based on the work of Dutch chemist Jacobus Henricus van 't Hoff who had noted in 1884 that the van 't Hoff equation for the temperature dependence of equilibrium constants suggests such a formula for the rates of both forward and ...

  4. Normalized difference vegetation index - Wikipedia

    en.wikipedia.org/wiki/Normalized_difference...

    NDVI is functionally and linearly equivalent to the ratio NIR / (NIR+VIS), which ranges from 0 to 1 and is thus never negative nor limitless in range. [6] But the most important concept in the understanding of the NDVI algebraic formula is that, despite its name, it is a transformation of a spectral ratio (NIR/VIS), and it has no functional ...

  5. Diffuse reflectance spectroscopy - Wikipedia

    en.wikipedia.org/wiki/Diffuse_reflectance...

    Karl Norris pioneered the field of near-infrared spectroscopy. [23] He began by using log(1/ R ) as a metric of absorption. While often the samples examined were “infinitely thick”, partially transparent samples were analyzed (especially later) in cells that had a rear reflecting surface (reflector) in a mode called "transflectance".

  6. Help:Displaying a formula - Wikipedia

    en.wikipedia.org/wiki/Help:Displaying_a_formula

    Spaces within a formula must be directly managed (for example by including explicit hair or thin spaces). Variable names must be italicized explicitly, and superscripts and subscripts must use an explicit tag or template. Except for short formulas, the source of a formula typically has more markup overhead and can be difficult to read.

  7. Goff–Gratch equation - Wikipedia

    en.wikipedia.org/wiki/Goff–Gratch_equation

    The Goff–Gratch equation is one (arguably the first reliable in history) amongst many experimental correlation proposed to estimate the saturation water vapor pressure at a given temperature. Another similar equation based on more recent data is the Arden Buck equation .

  8. Near-infrared window in biological tissue - Wikipedia

    en.wikipedia.org/wiki/Near-infrared_window_in...

    The near-infrared (NIR) window (also known as optical window or therapeutic window) defines the range of wavelengths from 650 to 1350 nanometre (nm) where light has its maximum depth of penetration in tissue. [1] Within the NIR window, scattering is the most dominant light-tissue interaction, and therefore the propagating light becomes diffused ...

  9. Conversion of scales of temperature - Wikipedia

    en.wikipedia.org/wiki/Conversion_of_scales_of...

    This is a collection of temperature conversion formulas and comparisons among eight different temperature scales, several of which have long been obsolete.. Temperatures on scales that either do not share a numeric zero or are nonlinearly related cannot correctly be mathematically equated (related using the symbol =), and thus temperatures on different scales are more correctly described as ...