When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Solar irradiance - Wikipedia

    en.wikipedia.org/wiki/Solar_irradiance

    Global Map of Global Horizontal Radiation [5] Global Map of Direct Normal Radiation [5] There are several measured types of solar irradiance. Total solar irradiance (TSI) is a measure of the solar power over all wavelengths per unit area incident on the Earth's upper atmosphere. It is measured perpendicular to the incoming sunlight. [3]

  3. Positron emission tomography - Wikipedia

    en.wikipedia.org/wiki/Positron_emission_tomography

    Positron emission tomography (PET) [1] is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in metabolic processes, and in other physiological activities including blood flow, regional chemical composition, and absorption. Different tracers are used for various imaging ...

  4. Radiation damage - Wikipedia

    en.wikipedia.org/wiki/Radiation_damage

    Radiation damage is the effect of ionizing radiation on physical objects including non-living structural materials. It can be either detrimental or beneficial for materials. Radiobiology is the study of the action of ionizing radiation on living things, including the health effects of radiation in humans.

  5. Sunlight - Wikipedia

    en.wikipedia.org/wiki/Sunlight

    The direct normal illuminance (E dn), corrected for the attenuating effects of the atmosphere is given by: =, where c is the atmospheric extinction and m is the relative optical airmass. The atmospheric extinction brings the number of lux down to around 100,000 lux.

  6. Irradiation - Wikipedia

    en.wikipedia.org/wiki/Irradiation

    Irradiation is the process by which an object is exposed to radiation. An irradiator is a device used to expose an object to radiation, notably gamma radiation, for a variety of purposes. [1] Irradiators may be used for sterilizing medical and pharmaceutical supplies, preserving foodstuffs, alteration of gemstone colors, studying radiation ...

  7. Radiation hormesis - Wikipedia

    en.wikipedia.org/wiki/Radiation_hormesis

    Radiation hormesis. Alternative assumptions for the extrapolation of the cancer risk vs. radiation dose to low-dose levels, given a known risk at a high dose: supra-linearity (A), linear (B), linear-quadratic (C) and hormesis (D). Radiation hormesis is the hypothesis that low doses of ionizing radiation (within the region of and just above ...

  8. Cell survival curve - Wikipedia

    en.wikipedia.org/wiki/Cell_survival_curve

    Solid lines represent neutron radiation and dashed lines X-ray radiation. A cell survival curve is a curve used in radiobiology. It depicts the relationship between the fraction of cells retaining their reproductive integrity and the absorbed dose of radiation. Conventionally, the surviving fraction is depicted on a logarithmic scale, and is ...

  9. Laser - Wikipedia

    en.wikipedia.org/wiki/Laser

    Laser. A telescope in the Very Large Telescope system producing four orange laser guide stars. A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word laser is an anacronym that originated as an acronym for light amplification by stimulated emission ...