A possibility of emission of high frequency gravitational radiation from   junctions between d-wave and s-wave superconductors
  Recent measurements on a class of high-Tc superconductors (HTSCs) have shown that Cooper-pairs wavefunction is a d-wave, while in another class, d-wave and s-wave may coexist. Conventional low-Tc superconductors are s-wave superconductors. When d-wave Cooper-pairs are injected in a superconductor that can sustain s-wave pairing, d-wave pairs are subject to transition to s-wave pairs and energy is irradiated by means of gravitons. We show that in s-wave to d-wave type superconductor (SDS) junctions in an equilibrium condition no net gravitational wave energy is emitted, on the other hand under non equilibrium conditions a net gravitational wave energy is emitted by the junction. Experiments that show a gravitational interaction between inhomogeneous high-Tc superconductors, under non-equilibrium conditions, and test objects may be understood by accepting a possibility of emission of gravitational radiation from SDS junctions. 
Giorgio Fontana