Nomenclature SyMbol Unit resistivity valence of ion proton density pressure C CCCdDGfFrLLkLm membrane capacitance threshold charge universal gas constant lateral beamwidth transmembrane resistance doppler shift S/m Larmour frequency decay tim Faraday constant pressure reflection coefficient minimum threshold current A threshold current A npQRRottTvwZZ bsolute temperature membrane potential nodal gap width propagation constant valence of substance internodal distance mass g c 2000 by CRC Press LLC© 2000 by CRC Press LLC Nomenclature Symbol Quantity Unit C resistivity Ω C proton density Cm membrane capacitance F d diameter m D lateral beamwidth fd doppler shift Hz fL Larmour frequency Hz F Faraday constant Γ pressure reflection coefficient Imt minimum threshold current A It threshold current A k propagation constant L internodal distance m m mass g Symbol Quantity Unit n valence of ion p pressure N/m QT threshold charge C R universal gas constant R transmembrane resistance Ω σ conductivity S/m td decay time s tr rise time s T absolute temperature K V membrane potential V W nodal gap width Z valence of substance Z acoustic impedance W