Mössbauer diffractometry on polycrystalline (57)Fe3Al

A Mossbauer powder diffractometer was used to measure diffraction patterns from polycrystalline foils of (Fe3Al)-Fe-57. The intensities of Bragg diffractions were measured as a function of the energy of the incident photon. The bee fundamental diffractions showed large changes in intensity as the incident energy was tuned through the nuclear resonances. These variations of diffraction intensity with incident energy were calculated with reasonable success using a kinematical theory of diffraction that included effects of coherent interference between x-ray Rayleigh scattering and, more importantly for these samples, Mossbauer scattering from nuclei having different hyperfine magnetic fields

Effects of Controlled Defects on the Vortex-Solid Melting Transition of Y-Ba-Cu-O Single Crystals

We report systematic studies of the dc transport properties in proton-irradiated Y-Ba-Cu-O single crystals. We find that the onset of vortex dissipation in moderately irradiated samples is associated with the occurrence of a second-order vortex-solid melting transition. In addition, the decreasing zero-field transition temperature and increasing critical current density with the increasing defects reveal the effects of disorder on reducing the electron mean-free-path and on increasing the pinning density

Vortex-solid melting and depinning in superconducting Y-Ba-Cu-O single crystals irradiated by 3-MeV protons

Compositionally modulated thin films of Cu and Y were prepared in an ultrahigh-vacuum dc ion-beam deposition chamber. The amorphization reaction was monitored by in situ x-ray-diffraction measurements. Growth of amorphous Cu1-xYx is observed at room temperature with the initial formation of a Cu-rich amorphous phase. Further annealing in the presence of unreacted Y leads to Y enrichment of the amorphous phase. Growth of crystalline CuY is observed for T=469 K. Transmission-electron-microscopy measurements provide real-space imaging of the amorphous interlayer and growth morphology. Models are developed, incorporating metastable interfacial and bulk free-energy diagrams, for the early stage of the amorphization reaction

Evidence of a Bose-glass transition in superconducting YBa2Cu3O7 single crystals with columnar defects

Experimental evidence of a Bose-glass transition in the vortex state of YBa2Cu3O7 single crystals with columnar defects along the c axis is manifested by the universal critical exponents ν⊥, ν∥ (≡ζν⊥), and z’ derived from the (d’+1)-dimension critical scaling of the frequency-dependent ac resistivity from 102 to 2.5×106 Hz. The Bose-glass transition temperature (TBG) is found to decrease with the increasing angle (θ) between the applied magnetic field and the c axis. The finding that ζ=ν∥/ν⊥=1.1±0.1<d’=2 suggests an incompressible Bose glass at temperatures below TBG

Complete uterine inversion during caesarean section: A case report

Inversion of the uterus through the uterine lower segment incision during a caesarean section is an extremely rare obstetric incident. It consists, though, an emergency complication that is potentially life-threatening, especially in cases of prolonged inversion, because haemodynamic instability and shock may occur. Prompt diagnosis and immediate uterine reversion are the key actions in the management of this serious complication

Anterior transverse cervical rupture following intra-amniotic prostaglandin induced mid-trimester abortion

Sir, A 30 years old 5th gravida with previous four full term normal vaginal deliveries was admitted at 18 weeks period of gestation for termination of pregnancy following ultrasound revealing anencephalic foetus. Physical examination revealed a uterus corresponding to 18 weeks gestational age

Letter to the Editor - Anterior Transverse Cervical Rupture Following Intra-Amniotic Prostaglandin Induced Mid-trimester Abortion

Sir, A 30 years old 5th gravida with previous four full term normal vaginal deliveries was admitted at 18 weeks period of gestation for termination of pregnancy following ultrasound revealing anencephalic foetus. Physical examination revealed a uterus corresponding to 18 weeks gestational age