Melt derived

In the second procedure, calcium nitrate was replaced by calcium alkoxide (60). Calcium and sificon alkoxides have very different rates of hydrolysis. To avoid the production of inhomogeneities, a slow and controlled hydrolysis of a mixture of sificon, calcium, and phosphorous alkoxide was performed. The resulting materials were highly homogenous, and monolithic pieces could be produced. The bioactivity of the gel-derived materials is equivalent or greater than melt-derived glasses. 

Fig. 12.4 Te rnary phase diagram for Si02-Ca0-Na20 melt-derived glasses.

Rather than partial melts derived from in-situ anatexis (i.e., leucosomes) these veins are trondhjemitic and represent distal magmatic injections from nearby... 

O, H, C, S, and N isotope compositions of mantle-derived rocks are substantially more variable than expected from the small fractionations at high temperatures. The most plausible process that may result in variable isotope ratios in the mantle is the input of subducted oceanic crust, and less frequent of continental crust, into some portions of the mantle. Because different parts of subducted slabs have different isotopic compositions, the released fluids may also differ in the O, H, C, and S isotope composition. In this context, the process of mantle metasomatism is of special significance. Metasomatic fluids rich in Fe +, Ti, K, TREE, P, and other large ion lithophile (LIE) elements tend to react with peridotite mantle and form secondary micas, amphiboles and other accessory minerals. The origin of metasomatic fluids is likely to be either (1) exsolved fluids from an ascending magma or (2) fluids or melts derived from subducted, hydrothermally altered crust and its overlying sediments. 

Isothermal Fiber Spinning of a Power Law Melt Derive the following expression for the axial velocity vz(z) resulting from the steady isothermal fiber spinning of a Power Law melt... 

Figure 1.9 Comparison of the processing of melt-derived glasses and gel-derived glass-like solids.

Recrystallization is best effected from n-heptane, carbon tetrachloride, or diethyl ether. The fact that many amines yield sharply melting derivatives with the sulfamoyl chlorides suggests that the latter may be useful in characterizing the former. 

Papike J. J. (1998) Comparative planetary mineralogy chemistry of melt-derived pyroxene, feldspar, and olivine. In Planetary Materials, Reviews in Mineralogy (ed. J. J. Papike). Mineralogical Society of America, Washington, DC, vol. 36, chap. 7, pp. 7-10-7-11. 

Primary Lavas, melts, and liquids derived solely via melting of a specihc, homogeneous source. In practice, it is hard to recognize or even conceive of a truly primary melt. Strictly speaking, even mantle-derived MORBs may be mix-mres of primary melts derived from a variety of sources, including polybaric melts of variably depleted peridotites and/or basaltic veins. For brevity we have used the term primary in a few cases in this chapter. Where it is used without qualihcation, we refer to melts that are, or could be, in equilibrium with mantle olivine with Mg = 90-93. 

Use. The reagent reacts with ketosteroids to form crystalline, high-melting derivatives. 

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