Narrow Results

We consider a situation when observations can increase particle flow across a barrier by many orders of magnitude compared with the tunneling probability (a barrier anti-Zeno effect). It may be of interest for explaining the paradoxical results of experiments on “cold fusion” that has earlier been observed by other authors for various systems.

We examine the anti-Zeno effect in a model of a barrier of a special shape, which has similarities with the form of barriers to nuclear fusion in a solid, and moreover has an analytic solution. We have deducted formulas that demonstrate the conditions of increasing the barrier permeability.

This paper studies the formation cross-sections of super heavy (SH) nuclei in some cold fusion reactions of radioactive neutron-rich projectiles with double-magic ²⁰⁸Pb target. In this study, the cross-sections of capture, fusion and evaporation residues in one- and two-neutron (1n and 2n) channels are calculated by using neutron-rich Fe, Ni and Zn projectiles are compared to the cross-sections calculated using stable Fe, Ni and Zn projectiles. The heights of fusion barrier and their positions in all reactions considered in this study are also compared to the heights and positions calculated using the estimation method proposed by Dutt and Puri. For cold fusion reactions with stable Fe, Ni and Zn projectiles, the heights of fusion barrier and the cross-sections of evaporation residues in 1n and 2n channels are compared to their corresponding experimental data. In general, for reactions using projectiles with the same proton number, the neutron-rich projectile is found to yield relatively-heavier mass of SH nucleus and larger evaporation residue cross-section, compared to those of the corresponding stable projectiles. However, in certain reactions, the cross-sections of neutron-rich projectile can be slightly larger or slightly smaller than that of the corresponding stable projectile. This behavior is highly affected by the charge of projectile and the fission barrier of the formed compound nucleus (CN). In addition, the ²⁹²114 is found to be the heaviest compound nucleus formed in cold fusion reaction by using neutron-rich nuclei as the projectile, but the cross-section of evaporation residue in one-neutron channel is still around few pico barns (pb).

While in revision hip surgery it has been described cold welding of the femoral component in titanium implants, no previous reports have been published in TMC prosthesis. We present a case report of a patient who sustained a TMC ARPE® dislocation 11 months after surgery and during revision surgery, cold welding of the neck with the metacarpal stem was observed. This may represent a problem when revising this prosthesis and alternative procedures should be advised and discussed with the patient when revising these implants.