Surface glassy

The gangue composition of the various carbonatite ores varies considerably. Calcite-dolomite content in some ores ranges from 30% (Niobec, Canada) up to 70% (Panda Hills, Africa). From a mineralogical point of view, pyrochlore usually occurs in crystallized form, as well as octahedron form. Pyrochlore occurs in considerable range of colours, varying from translucent white to opaque black appearance with glassy surfaces. The Nb205... 

I m sure you will be well received," called the priest from the river as he wheeled the little speedboat around. Then he was gone. Long after he had turned a bend in the river and the sound of his departure had faded, the glassy surface of the river still moved and sucked against the banks as a last echo of the unusual commotion. 

The vitriols, blue, green, and white, were especially important because it was from them that vitriolic acid was prepared. The natural vitriols, copper, iron, and zinc sulfates respectively, were so named presumably because of the glassy surfaces of their crystals (from the Latin vitreus like glass ). 

A very attractive method for glassy surface activation is silanization with reactive silanes. Thus, many research groups use aldehyde-modified silanes [25], epoxy silanes [26], and mercapto-silanes [27,28] for generating reactive surfaces. Commonly applied silanes are shown in Fig. 13. In the case of the aldehyde linkage a 5 -amino or hydrazide-modified [29] single strand... 

Another approach is to apply a material that forms an insulating layer around the fibre at temperatures below the fibre pyrolysis temperature. Boric acid and its hydrated salts function in this capacity (Fig. 8.4). When heated, these low melting compounds release water vapour and produce a foamed glassy surface on the fibre, insulating the fibre from the apphed heat and oxygen. 

The QCM has added valuable information about the mechanism of vesicle fusion on a surface. For instance, Kasemo and coworkers have unraveled the formation of planar lipid bilayers on Si02 and glassy surfaces by means of the QCM with dissipation (QCM-D) technique in conjunction with SPR, atomic force microscopy (AFM), and computer simulations [5-12]. They found that the process of bilayer formation occurs in three successive steps (1) in the first stage, vesicles attach to the surface via inter molecular interactions (2) at a critical surface coverage, the vesicles start to rupture, fuse on the surface, and thus form bilayer islands coexisting with vesicles and uncovered substrate (3) eventually, a coherent bilayer is formed covering the entire surface. 

Stoneware Porosity 0.5-3% Firing temperature 1100-1300°C Glassy surface Crucible, labware, pipe ... 

The unmodified epoxy system showed cracks at different planes on the smooth glassy surface, indicating brittle failure, while the fracture surfaces of the rubber-modified ones were rough, indicating massive shear deformation Figure 15.1. The morphology appeared as a phase-separated one with the dispersion of small rubber domains in the epoxy matrix. However, the particle size increased with increase in rubber content due to the coalescence process. 

Diffusion of components into the surface. For example, by introducing silver ions in this way into a glassy surface, a thin layer with a higher refractive index is formed. The latter makes up the core of the optical sensor. 

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