Plasma (physics) potential in the space between charged particles, independent of how it can be measured, is called the "plasma potential", or the "space potential". If an electrode is inserted into a plasma, its potential will generally lie considerably below the plasma potential due to what is termed a Debye sheath. The good electrical conductivity of plasmas makes their electric fields very small. This results in the important concept of "quasineutrality", which says the density of negative charges is approximately equal to the density of positive charges over large volumes of the plasma (formula_6), but on the scale of the Debye length
Positive and Negative Affect Schedule valid instrument in the assessment of positive and negative affect. The PANAS was developed in 1988 by researchers from the University of Minnesota and Southern Methodist University. Previous mood measures have shown correlations of variable strength between positive and negative affect, and these same measures have questionable reliability and validity. Watson, Clark, and Tellegen developed the PANAS in an attempt to provide a better, purer measure of each of these dimensions. The researchers extracted 60 terms from the factor analyses of Michael Zevon and Tellegen shown to be relatively accurate markers of either positive or negative affect, but not both.