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  2. Spectrum - Wikipedia

    en.wikipedia.org/wiki/Spectrum

    The word spectrum was first used scientifically in optics to describe the rainbow of colors in visible light after passing through a prism. As scientific understanding of light advanced, it came to apply to the entire electromagnetic spectrum. It thereby became a mapping of a range of magnitudes (wavelengths) to a range of qualities, which are ...

  3. Electromagnetic spectrum - Wikipedia

    en.wikipedia.org/wiki/Electromagnetic_spectrum

    By definition, visible light is the part of the EM spectrum the human eye is the most sensitive to. Visible light (and near-infrared light) is typically absorbed and emitted by electrons in molecules and atoms that move from one energy level to another.

  4. Glossary of chemistry terms - Wikipedia

    en.wikipedia.org/wiki/Glossary_of_chemistry_terms

    Also acid ionization constant or acidity constant. A quantitative measure of the strength of an acid in solution expressed as an equilibrium constant for a chemical dissociation reaction in the context of acid-base reactions. It is often given as its base-10 cologarithm, p K a. acid–base extraction A chemical reaction in which chemical species are separated from other acids and bases. acid ...

  5. Full width at half maximum - Wikipedia

    en.wikipedia.org/wiki/Full_width_at_half_maximum

    Full width at half maximum. In a distribution, full width at half maximum (FWHM) is the difference between the two values of the independent variable at which the dependent variable is equal to half of its maximum value. In other words, it is the width of a spectrum curve measured between those points on the y-axis which are half the maximum ...

  6. Standardized uptake value - Wikipedia

    en.wikipedia.org/wiki/Standardized_Uptake_Value

    3-dimensional [18 F]FDG-PET image with 3D ROI generated by a threshold based algorithm.The blue dot in the MIP image bottom right marks the maximum SUV within the ROI.. The standardized uptake value (SUV) is a nuclear medicine term, used in positron emission tomography (PET) as well as in modern calibrated single photon emission tomography (SPECT) imaging for a semiquantitative analysis. [1]

  7. Single-photon emission computed tomography - Wikipedia

    en.wikipedia.org/wiki/Single-photon_emission...

    To acquire SPECT images, the gamma camera is rotated around the patient. Projections are acquired at defined points during the rotation, typically every 3–6 degrees. In most cases, a full 360-degree rotation is used to obtain an optimal reconstruction. The time taken to obtain each projection is also variable, but 15–20 seconds is typical.

  8. Game of the Day: Just Words - AOL

    www.aol.com/news/2014-05-18-game-of-the-day-just...

    Just Words is a word game for one or two players where you scores points by making new words using singularly lettered tiles on a board, bringing you the classic SCRABBLE experience, but with a twist!

  9. Spectroscopy - Wikipedia

    en.wikipedia.org/wiki/Spectroscopy

    Spectroscopy is a branch of science concerned with the spectra of electromagnetic radiation as a function of its wavelength or frequency measured by spectrographic equipment, and other techniques, in order to obtain information concerning the structure and properties of matter. [4]