Efficient heating with a controlled microwave field.

To uncover the intriguing non-thermal microwave effect, an experiment was conducted using an amplifier rather than an oscillator as the radiation source, which was injected into an applicator with strong electromagnetic field enhancement. The characteristics of the applicator are discussed and the enhancement of the microwave field is illustrated and explained. Thermal distribution is simulated based on the calculated microwave field profile. It was demonstrated that the proposed system heated a SiC susceptor to a temperature of 637 °C with the input power of 60 W. The reasons for such an efficient heating are discussed.

Correlation between magnetic properties and the electronic structures of soft magnetic ternary Fe(78-x)Y(x)B(22) (x = 4-9) bulk metallic glasses.

Fe and Y K-edge extended x-ray absorption fine structure, Fe(Y) L(3,2)-edge (L(3)-edge) x-ray absorption near-edge structure (XANES) and valence-band photoemission spectroscopy (VB-PES) measurements have been carried out to study soft magnetic ternary Fe(78-x)Y(x)B(22) bulk metallic glasses (BMGs). The combined XANES and VB-PES results do not show broadening of the Fe 3d band to support the previous interpretation of the reduction of the magnetic moment in BMGs by Y-induced decrease of exchange splitting of Fe 3d orbitals. Instead, the density of delocalized/itinerant Fe 3d states in the vicinity of the Fermi level is found to be reduced by Y substitution, which reduces the strength of itinerant-states-mediated ferromagnetic coupling between local spins on the Fe ions and the total magnetic moment of the Fe-based BMGs.

Phase purity of sol-gel-derived hydroxyapatite ceramic.

Calcium oxide was reported in the sol-gel-derived hydroxyapatite (HA) as an unavoidable major impurity. In this study phase purity of HA synthesized by sol-gel route was explored using precursors of calcium nitrate tetrahydrate and triethyl phosphate. Two different drying methods, the fast drying of as-prepared precursors and the slow drying of aged precursors were adopted as major processing variables. The dried gels were subsequently calcined up to 600 degrees C. In the calcined powder from fast-dried gel, X-ray diffraction (XRD) patterns revealed an intense CaO peak. For the slow-dried gel, thermogravimetric analysis revealed a 2-step weight-loss behavior during heating. XRD analysis of the calcined powder, corresponding to the second weight-loss step, showed major peaks of hydroxyapatite and a very weak CaO peak. P-31 NMR analysis indicated formation of calcium phosphate complex during aging. Complete incorporation of Ca(NO3)2 into the complex due to proper aging therefore diminishes CaO formation. It was also found that the minor CaO derived in the slow drying method can be easily and completely washed out just by distilled water.

Bioaccumulation and distribution of mercury in the hard clam, Meretrix lusoria (Bivalvia: Veneidae).

1. Total mercury concentration in whole soft parts of the hard clam, Meretrix lusoria, increased significantly with increasing exposure concentrations. It reached 4.247-7.084 and 9.956-13.643 micrograms T-Hg/g dry weight in 5 and 50 micrograms/l Hg mercury solution, respectively, against a background level of 1.824-0.577 micrograms T-Hg/g dry weight. 2. Bioconcentration factor was 4-6 times higher in 5 micrograms/l Hg than that of 50 micrograms/l Hg. An estimated biological half-life of 20.2 and 18.4 days in 5 and 50 micrograms/l Hg, respectively, were also obtained after 14 days uptake. 3. Accumulation of mercury in tissues of the clams was greater in the gills and viscera than in the mantle, adductor, foot, or hemolymph. 4. The amount of mercury present in the gills is related to be a linear relationship with the mercury content of viscera.