Refractory classification

Fig. 2. Thermal conductivity of refractories where ASF = aluminosiUcate fiber and ZF = 2ii conia fiber. See Table 13 for group classifications (5,25).

Table 15. ASTM C435 Classification For Steel-Pouring Pit Refractories ...

Describe the modified Vaughan-Williams classification of antiarrhythmic drugs, and compare and contrast the effects of available antiarrhythmic drugs on ventricular conduction velocity, refractory period, automaticity, and inhibition of specific myocardial ion channels. 

The Vaughan-Williams classification of antiarrhythmic drugs has been criticized for a number of reasons. The classification is based on the effects of drugs on normal, rather than diseased, myocardium. In addition, many of the drugs may be placed into more than one class. For example, the class IA drugs prolong repolarization/refractoriness, either via the parent drug8,9 or an active metabolite,10 and therefore also maybe placed in class III. Sotalol is also a 3-blocker, and therefore fits into class II. Amiodarone inhibits sodium and potassium channels, is a non-competitive inhibitor of 3-receptors, and inhibits calcium... 

Adenosine and digoxin are agents used for the management of arrhythmias that do not fit into the Vaughan Williams classification. aSlows conduction, prolongs refractory period, and reduces automaticity in SA node and AV node tissue, but not in the ventricles. 

MAO Is have not been evaluated systematically for treatment of PD under the current diagnostic classification and generally are reserved for patients who are refractory to other treatments.48,49 MAOIs have significant side effects that limit adherence. Additionally, patients must adhere to dietary restriction of tyramine and avoid sympathomimetic drugs to avoid hypertensive crisis. 

The most frequently used classification system is that proposed by Vaughan Williams (Table 6-1). Type la drugs slow conduction velocity, prolong refractoriness, and decrease the automatic properties of sodium-dependent (normal and diseased) conduction tissue. Type la drugs are broad-spectrum antiarrhythmics, being effective for both supraventricular and ventricular arrhythmias. 

Castable refractories, ASTM classifications and specifications for, 27 510 Castables, 27 482 Cast alloys, 73 524 Cast copper-beryllium alloys, 3 653t,... 

High alumina brick, ASTM classifications and specifications for, 21 508 High alumina catalysts, 11 724 High alumina refractories, 21 515, 518 High analysis fertilizers, 11 123, 124 High aspect ratio micromachining... 

Kinetic parameters of fast pyrolysis were derived while assuming a single process for the decomposition of wood, including three parallel first-order decay reactions for the formation of the product classes. This is the so-called Shafizadeh scheme [56]. The three lumped product classes are permanent gas, liquids (biooil, tar), and char a classification that has become standard over the years. The produced vapors are subject to further degradation to gases, water and refractory tars. Charcoal, which is also being formed, catalyzes this reaction and therefore needs to be removed quickly [57]. 

At the largest scale, the DOM pool can be resolved into four functional pools labile, semilabile, recalcitrant, and refractory (Fig. 6). This classification reflects both chemical composition, measured in units of intermediatory... 

This model assumes a more simplified classification of the DOM pool than the one described in Section HI. The labile and semilabile DOM fractions shown in Fig. 6 have been combined to form the labile DOC pool the recalcitrant DOC (RDOC) pool remains the same as that defined in Fig. 6 and the refractory DOC pool is not part of the model. 

Biochemical classification may also be applied and indeed would be most appropriate. However, the three main biochemical classes (polysaccharides, proteins, lipids) represent only approximately 20-30% of the NOM in freshwater bodies, the remainder being an ill-characterised mixture of varying proportions of refractory pedogenic and aquagenic organic matter (PROM and AROM, respectively). The major differences between PROM and AROM are (Buffle, 1988, Chapter 4), for the former ... 

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