The tooth plates in the living Holocephalan, Chimaera phantasma were studied by various techniques. They consisted of osteodentin and hypermineralized pleromin (kosmin). The degree of mineralization on the latter was as much as in the enameloid of Chondrichthyes and Osteichthyes. Scanning electron microscope observation indicated that the pleromin consisted of large and granular crystals. X-ray...

Three high-silica mordenite zeolites differing in SiO440, ratio were prepared by direct synthesis without using any template. The products Si02/A120, ratio is influenced by the starting gel composition. This ratio is increased upon ion-exchange with NH,Cl and subsequent calcination to prepare protonic mordenite. The protonic mordenites with Si02/A1203ra tios of 14.6,29.2 and 34.6 were chara...

Sites with high calcium affinity in Paramecium aurelia were identified by high calcium (5 mM) fixation and electron microscope methods. Electron-opaque deposits were observed on the cytoplasmic side of surface membranes, particularly at the basal regions of cilia and trichocyst-pellicle fusion sites. Deposits were also observed on some smooth cytomembranes, within the axoneme of cilia, and on b...

This study examined the effects of different treatments (polished, electropolished, and grit-blasted) on the surface morphology and chemistry of commercially pure titanium and titanium-6% aluminum-4% vanadium. The structure and composition of the surfaces were evaluated using scanning electron microscopy, atomic force microscopy, energy dispersive spectroscopy, Auger microprobe analysis, and x-...

The electron microprobe (EMP) is an electron optical instrument in which compositional and topographic information are obtained from regions ~lban in diameter on a specimen. Photographs of compositional and topographic changes in 1-mm 2 to 20-/din 2 areas on various types of specimens can also be obtained which are strikingly similar to optical photomicrographs. This paper discusses the various...