Lutes, composition

Sapphire. —To produce a fine oriental blue color, one must employ very white strass, and very pure oxide of cobalt. This composition, put into a luted Hessian crucible, should remain thirty hours in the fire. Tho... 

Uses Ibr lampblack include Black pigment for cements, ceramic ware, monar. inks, linoleum, surface coaling, crayons, polishes, carbon paper, soap, etc. ingredient of insulating compositions, liquid-air explosives, matches, fertilizer, furnace lutes, lubricating compositions, carbon brushes reagent in cementation of siccl. 

As described in Section 2.13.2.4, there has been, and continues to be, much debate over the veracity of the highly positive isotopic compositions observed in >3.6 Ga rocks. Lute-tium and hafnium are sited in different phases than are samarium and neodymium, such that metamorphism and alteration should affect each isotopic system differently. One motivation for much of the hafnium isotopic work on Archean... 

Lute A composition employed to teci e the Joints of chemical vessels, or as a covering to protect them from the violence of the fire. 

The compositional and performance features of the zinc oxide-eugenol and zinc oxide-ort/zo-ethoxybenzoic acid cements were dealt with in Sections II.B.3 and II.B.4. While employed for temporary luting and filling, the ZOE materials find their major use in cavity lining. The fundamentally weak cement materials are usually reinforced for this... 

Systems with an Upper Critical Solution Temperature. In the case described in Fig. 2.1, which is typified by the system phenol-water, the solubilities of A in J5 and J5 in A increase with increase in temperature, so that at some elevated temperature the two conjugate solutions become identical and the interface between them consequently disappears. This temperature, termed the critical solution temperature (C.S.T.), or conso-lute temperature, occurs at the point M in the figure and represents the temperature above which mixtures of A and B in any proportions form but one liquid phase. Point M is the maximum on the continuous solubility curve but is not ordinarily at the midpoint of composition, nor are the solubility curves ordinarily symmetrical. The C.S.T. is the point where the two branches of the solubility curve merge, and the constant temperature ordinate is tangent to the curve at this temperature. The phase rule may be applied to this significant point ... 

The flux is linearly related to the composition difference and the diffiisivity and inversely proportional to the hydrodynamically dependent film thickness. Equation (2.3-53) can also be employed in lute solutions (Xa 1) where the bulk flow term Xa(Na + Afa) is neglected with respect to the diffusive term. 

It is obvious that the Boehm titration method is the most popular one for the determination of various types of acidic (and basic) surface functionalities in carbon materials. From 1966 until 2002, when Boehm himself published a critical assessment of the analysis of surface oxides on carbon [201], an exhaustive utilization of this method has been desaibed by many authors. They underlined its simplicity, but pointed out also the need for using other complementary methods such as potentiometric titration, tanperature-programmed desorption (TPD), spectroscopic methods (mainly XPS and FTIR), and thermodynamic approaches such as calorimetry. The case of TPD is of special interest, to identify oxygenated functionalities. However, the CO and CO2 peaks must certainly be deconvo-luted before the surface composition can be estimated. Thus, a quantitative TPD analysis of surface functional groups is sensitive to the deconvolution method and to experimental conditions. The results are generally discussed in relation to those of DRIFTS and XPS analysis, as can be seen from the references listed in Table 3.1. 

Lute n. ( o5t) Also called luting, a mixture of cement and clay used to seal the joints between pipes, etc. 2. (Medicine / Dentistry) Dentistry a thin layer of cement used to fix a crown or inlay in place on a tooth vb (Miscellaneous Technologies / Budding) (tr) to seal (a joint or surface) with lute [via Old French ultimately from Latin lutum clay]. Generally, a material placed around a conduit for physically securing and/or thermally insulating for a gas or liquid. Some modern polymeric composite lutens have been developed. 

FIG. 16 Effect of unsaturation on the softening of compositions (Fig. 9) (8-times-di-luted samples, softening by DHTDMAC (5% dispersion) gives a value of 8.1). 

Paffenbarger (12) indicates that dental cements are used as filling materials, luting media, obtundent dressings, impression pastes, and as bases for other restorative materials. He lists six classes of cements. Today, a seventh class, the glass-ionomer cements, may have to be added to his classification, since these products straddle his classes C-4 and C-5 compositionally. 

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