We present results for the operation of a three-level solid-state laser both with normal and with completely suppressed spontaneous emission between the lasing levels. The output power difference in these two cases drops as the pump rate is increased above threshold and is not greatly different at higher powers. The threshold pump power, although typically reduced by an order of magnitude, is n...

We have synthesized ozone by irradiating thin solid ®lms of oxygen and oxygen±water mixtures with 100 keV protons, motivated by recent reports of condensed O3 on icy satellites in the outer Solar system. We measured the depth of the Hartley absorption band in the ultraviolet by re ̄ectance spectroscopy and used it to quantify the column density of ozone. We analyzed the results using a three-com...

this study aimed to evaluate enamel roughness after adhesive removal using different burs and an er:yag laser.the buccal surfaces of forty human premolars were sealed by two layers of nail varnish, except for a circular area of 3 mm in diameter on the middle third. the enamel surfaces were initially subjected to profilometry analysis and four parameters of surface irregularity (ra, rq, rt and r...

the synthesis of nb doped batio3 has been investigated under microwave-hydrothermal (mh) conditions in the temperature of 150°c for only 2 h using c16h36o4ti, bah2o2.8h2o and nbcl5 as ba, ti and  nb sources, respectively.  typical experiments performed on mh processing have not yet reported for nb doped batio3.  in the mh process, the formation of high purity nano tetragonal nb-batio3 was stron...

Nano-sized BaTiO3 powders with particular Nb concentrations were prepared by Rotary- Hydrothermal (RH) method. Hydrothermal method was used at 180 °C for 5 hours with new Ti pressure and the teflon vessel was rotated at a speed of 160 rpm during the hydrothermal reaction. New hydrothermal method was used instead of previous solid state reaction for the system BaTiO3±Nb<sub...

Nano-sized BaTiO3 powders with particular Nb concentrations were prepared by Rotary- Hydrothermal (RH) method. Hydrothermal method was used at 180 °C for 5 hours with new Ti pressure and the teflon vessel was rotated at a speed of 160 rpm during the hydrothermal reaction. New hydrothermal method was used instead of previous solid state reaction for the system BaTiO3±Nb<sub...