Phenomenological Model of Corrosion Process in Reinforced Concrete identified by AE

Corrosion of reinforcing steel is modelled phenomenologically as corrosion losses of three phases.   In order to identify the corrosion process in reinforced concrete based on the model, continuous AE monitoring in reinforced concrete specimens was conducted in an accelerated corrosion test and a cyclic wet and dry test.   It is demonstrated that two periods of high AE activities are observed.  The 1st AE activity corresponds to the onset of the corrosion in rebar of the 1st phase in the phenomenological model.  At the 2nd period of high activity AE events result from concrete cracking, corresponding to the 3rd phase in the model

A New Class of Majoron-Emitting Double-Beta Decays

Motivated by the excess events that have recently been found near the endpoints of the double beta decay spectra of several elements, we re-examine models in which double beta decay can proceed through the neutrinoless emission of massless Nambu-Goldstone bosons (majorons). Noting that models proposed to date for this process must fine-tune either a scalar mass or a VEV to be less than 10 keV, we introduce a new kind of majoron which avoids this difficulty by carrying lepton number $L=-2$. We analyze in detail the requirements that models of both the conventional and our new type must satisfy if they are to account for the observed excess events. We find: (1) the electron sum-energy spectrum can be used to distinguish the two classes of models from one another; (2) the decay rate for the new models depends on different nuclear matrix elements than for ordinary majorons; and (3) all models require a (pseudo) Dirac neutrino, having a mass of a several hundred MeV, which mixes with $\nu_e$.Comment: 43 pages, 10 figures (included), [figure captions are now included