Frozen biological specimens in t-butyl alcohol were examined under a low-vacuum environment in a "wet SEM" or "variable pressure SEM (scanning electron microscope)" equipped with a cooling stage and highly sensitive backscattered detector of the YAG type. After fixation with glutaraldehyde and osmium tetroxide, rat tissue blocks (tracheae and kidneys), and cultured human carcinoma cells were de...

We have measured the kinetic energy of positronium (Ps) atoms emitted into a vacuum from a porous silica film subsequent to positron bombardment, via the Doppler spread of the linewidth of the Ps 13S-23P transition. We find that the deeper in the target film that positrons are implanted the colder is the emitted Ps, an effect we attribute to cooling via collisions in the pores as the atoms diff...

Heat treatment is generally applied to orthodontic stainless steel (SS) wires to relieve the stresses that result from their manipulation by orthodontists. The quality and thickness of the oxide films formed on the surface of heat-treated wires can vary, and it is believed that these oxide films can influence the properties of heat-treated wires. The aim of this study was to investigate the inf...

The application of tracer techniques to the sugar industry is reviewed. This includes the investigation of residence time distribution in clarifiers, evaporators, continuous pans, crystallizers and fluidized bed dryers; the flow split in diffusers and evaporator vessels; leak detection; measurement of entrainment in vacuum pans and determination of system volumes such as cooling water ponds.

The purpose of this study was to evaluate mechanical properties of the orthodontic wires according to heat treatment environments and cooling methods. Four types of wires were heat-treated in air, argon and vacuum at 500◦C, for 6 min, and were then either cooled in the furnace or a water bath. Increases in microhardness, maximal strength, yield strength and Young’s modulus of the orthodontic wi...