A quark model based on QCD scale anomaly

We consider a quark model based on QCD scale anomaly in which the quarks move in the field of an effective glueball field. Hadrons correspond to solitonic bags of higher energy density in a nonperturbative sea of condensed gluons. We calculate the static properties of nucleon in this model and find that the nucleon mass is far too large (2.4–4 GeV) and the proton charge radius (0.37–0.54 fm) is low. The proton gyromagnetic ratio and g_A/g_v are in reasonable agreement with the experimental numbers.     

Effects of delayed linear electrical perturbation of the Belousov-Zhabotinsky reaction: a case of complex mixed mode oscillations in a batch reactor

Delayed feedbacks are quite common in many physical and biological systems and in particular many physiological systems. Delay can cause a stable system to become unstable and vice versa. One of the well-studied non-biological chemical oscillators is the Belousov-Zhabotinskii (BZ) reaction. This gives relaxation oscillations for a considerable period of time under batch conditions. This paper deals with the effect of perturbing the limit cycle oscillation of BZ reaction by employing a delayed electrical feedback to the system under batch conditions. The parameters chosen to study are external resistance and delay. For various resistances and delays the system was electrically perturbed and found to exhibit various complex mixed mode oscillations. The dynamic features are accounted for by the Oregonator model, with time delay incorporated in one of the variables. This revised version was published online in June 2006 with corrections to the Cover Date.