NXY 059: CPI 22, NXY 059G

    Drugs in R&D
    |July 10, 2003
    PubMed

    Related Concept Videos

    Pilot and Numeric Relaying01:21

    Pilot and Numeric Relaying

    Pilot relaying is a type of differential protection used in power systems. It compares electrical quantities at the terminals of equipment via a communication channel instead of direct relay interconnection. This method is essential for transmission lines where the terminals are far apart, typically up to 80 km for lines with 69 to 115 kV ratings. Four types of communication channels are used for pilot relaying:
    Bond Energies and Bond Lengths02:49

    Bond Energies and Bond Lengths

    Stable molecules exist because covalent bonds hold the atoms together. The strength of a covalent bond is measured by the energy required to break it, that is, the energy necessary to separate the bonded atoms. Separating any pair of bonded atoms requires energy — the stronger a bond, the greater the energy required to break it.
    Le Chatelier's Principle: Changing Concentration02:27

    Le Chatelier's Principle: Changing Concentration

    A system at equilibrium is in a state of dynamic balance, with forward and reverse reactions taking place at equal rates. If an equilibrium system is subjected to a change in conditions that affects these reaction rates differently (a stress), then the rates are no longer equal and the system is not at equilibrium. The system will subsequently experience a net reaction in the direction of a greater rate (a shift) that will re-establish the equilibrium. This phenomenon is summarized by Le...
    Free Energy and Equilibrium02:56

    Free Energy and Equilibrium

    The free energy change for a process may be viewed as a measure of its driving force. A negative value for ΔG represents a driving force for the process in the forward direction, while a positive value represents a driving force for the process in the reverse direction. When ΔGrxn is zero, the forward and reverse driving forces are equal, and the process occurs in both directions at the same rate (the system is at equilibrium).
    Recall that Q is the numerical value of the mass action expression...