why mass spectrometric analysis is performed under ultra high vacuum
Ultra-high vacuum UHV conditions are integral to scientific research. Surface science experiments often require a chemically clean sample surface with the absence of any unwanted adsorbates. Surface analysis tools such as X-ray photoelectron spectroscopy and low energy ion scattering require UHV conditions for the transmission of electron or ion beams. For the same reason, beam pipes in particle accelerators such as the Large Hadron Collider are kept at UHV.[1]
Denial-of-service attack A wide array of programs are used to launch DoS-attacks.
Montreal Protocol "Recognizing that worldwide emissions of certain substances can significantly deplete and otherwise modify the ozone layer in a manner that is likely to result in adverse effects on human health and the environment. Determined to protect the ozone layer by taking precautionary measures to control equitably total global emissions of substances that deplete it with the ultimate objective of their elimination on the basis of developments in scientific knowledge"
Travis Van Winkle Travis Scott Van Winkle[1] (born November 4, 1982) is an American actor.[2]