4D-CT localized parathyroid adenomas with higher sensitivity among patients with recurrent or persistent PHPT compared with sestamibi or US-based imaging.

The low temperature specific heat of the metallic glasses (FexNi80−x)B20 heat of the metallic glasses Magnetostriction measurements as a function of temperature and composition are reported in non-crystalline Coso_,T,B 2o alloys (T = Fe, Mn, Cr or V with 0::; x::; 12 at. %). The room temperature saturation magnetostriction ..t , changes sign with the substitution of Fe, Mn or Cr for Co in CosoB,o glass. These results are well described by the virtual-bound-states jVBSs) introduced above the 3d band by the light T solutes. The positions of 3d' (3d majority spin) VBS with respect to the Fermi energy is established. The magnetostrictions of ConMnsB,o and C070CrlOB20 glasses (negative at 295 K) also change sign with increasing temperature. This is the first direct observation of magnetostriction-compensation temperatures in non-crystalline metals. The existence of these magnetostriction compensation temperatures is interpreted to be a consequence of the different temperature dependences of single-ion and two-ion contributions to..t ,.

Magnetostriction λs has been measured at room temperature and 80 K in Fe100−xBx (14?x?23 at.%) glasses using metal foil strain gauges. Several compositions were also studied as a function of temperature from 80 K to T ? TC. The single-ion uniaxial temperature dependence confirmed previously for Fe80B20 glass is also observed here for x=20 and 22. At lower boron concentrations departures from this expected temperature dependence are observed. The values of λs(295K) show a broad maximum of about 35×10−6 at x?20 at.%B. Crystallization of the glasses gives rise to a nonmonotonic temperature dependence of λs.

A basic Wheatstone bridge, with additional electronic instrumentation, has been used in the measurement of magnetostriction. This method allows a resolution of approximately 10% on measurements of magnetostrictions less than 0.75 parts per million.

Measurements were made on a series of glassy iron–boron alloys to determine the association of the eutectic composition (lowest melting point) and the field-induced magnetic anisotropy. When the boron was increased from 15 to 22 at. %, the magnetic anisotropy was found to increase from 500 to 1300 J/m3. There was no sharp discontinuity in the vicinity of the eutectic. It appears that deviation from the eutectic does not greatly influence the value of the magnetic anisotropy, provided the samples are small and are drastically quenched. Specimens having the eutectic composition had the most reproducible values of anisotropy. The substitution of silicon for some of the boron in these alloys raises their Curie and crystallization temperatures. This makes possible a greater range of heat treating temperatures and permits better stress relief in the alloys. Also, the substitution of silicon permits better control of the magnetic anisotropy. This control may be a factor in obtaining improved magnetic properties since both low coercive force and low hysteresis loss in these materials depend upon obtaining the proper value of uniaxial anisotropy. Compositions that had values of the field-induced anisotropy of 1000 J/m3 had low values of core loss when properly heat treated.