enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  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. 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 ...

  4. Raman spectroscopy - Wikipedia

    en.wikipedia.org/wiki/Raman_spectroscopy

    When operated in the visible to near-infrared range, a Raman microscope can achieve lateral resolutions of approx. 1 μm down to 250 nm, depending on the wavelength and type of objective lens (e.g., air vs. water or oil immersion lenses). The depth resolution (if not limited by the optical penetration depth of the sample) can range from 1–6 ...

  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. Normalized Difference Red Edge Index - Wikipedia

    en.wikipedia.org/wiki/Normalized_Difference_Red...

    The normalized difference red edge index (NDRE) is a metric that can be used to analyse whether images obtained from multi-spectral image sensors contain healthy vegetation or not. [1]

  7. 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 ...

  8. Free spectral range - Wikipedia

    en.wikipedia.org/wiki/Free_spectral_range

    The free spectral range of a diffraction grating is the largest wavelength range for a given order that does not overlap the same range in an adjacent order. If the ( m + 1)-th order of λ {\displaystyle \lambda } and m -th order of ( λ + Δ λ ) {\displaystyle (\lambda +\Delta \lambda )} lie at the same angle, then

  9. NTU method - Wikipedia

    en.wikipedia.org/wiki/NTU_Method

    The other fluid would change temperature more slowly along the heat exchanger length. The method, at this point, is concerned only with the fluid undergoing the maximum temperature change. The effectiveness of the heat exchanger ( ϵ {\displaystyle \epsilon } ) , is the ratio between the actual heat transfer rate and the maximum possible heat ...