RESUMO
Bose-Einstein condensation in a gas of magnons pumped by an incoherent pumping source is experimentally studied at room temperature. We demonstrate that the condensation can be achieved in a gas of bosons under conditions of incoherent pumping. The critical transition point is shown to be almost independent of the frequency spectrum of the pumping source and is solely determined by the density of magnons. The electromagnetic power radiated by the magnon condensate is found to scale quadratically with the pumping power. The obtained results are in a good agreement with the theory of Bose-Einstein condensation of quasiequilibrium magnons.
RESUMO
Electron microscopical investigation of the musculus deltoideus bioptates has been performed in wrestlers with a habitual shoulder-slip (7 persons). In the same persons contralateral muscle of the healthy arm has been studied (4 persons) and state of the muscle after operative treatment of the shoulder-slip (4 persons) has been analysed. At repeated shoulder-slips signs of the muscle atrophy are noted; this is clear from destructive changes of myofibrils, appearance of a great number of necrotized fibers, outgrowth of the connective tissue. In two cases ectopic formation of the bone in the muscle tissue has been observed. Increasing number of myosatellitocytes, appearance of newly formed fibers after the operative treatment contributes to restoration of the atrophied muscles. During rehabilitation period after the operative eradication of the shoulder-slip, when the program of the restorative loading is working out, it is necessary to take into consideration the severity of the trauma and duration of the disease, in order to avoid lesions of the weakend muscles.