Intrinsic selectivity

The first task, which should be completed before considering the design of any facility or equipment involving energetic material, is to define exactly what type of hazardous environment will be involved in each room, section or area. This is a prerequisite, whether selecting intrinsically safe or any other technique to provide electrical protection. 

Beta-adrenergic blocking agents, SELECTIVE, intrinsic SYMPATHOMIMETIC ACTIVITY (ISA)... 

Beta-adrenergic blocking agents, selective, intrinsic sympathomimetic activity (ISA) acebutolol hydrochloride... 

Table 8.4 summarises the currently available 3-adrenoceptor antagonists, their relative 31 selectivity, intrinsic sympathomimetic activity, and the availability of intravenous formulations. 

The stereochemical outcome of an aldol reaction involving more than one chiral component is consistent with the rule of approximate multiplicativity of diastereofacial selectivities intrinsic to the chiral reactants. For a matched case, the diastereoselectivity approximates (substrate DS) X (reagent DS). For a mismatched case, the diastereoselectivity is (substrate DS) (reagent DS). Double asymmetric induction also can be used to enforce the inherent facial selectivity of a chiral aldehyde, as shown below. 

Introduction site selectivity, intrinsic disorder and slow motions 175... 

Reactions and selected intrinsic equilibrium constants describing ionization of SOH and adsorption of Na and CF on quartz and corundum are listed in Table I. The formulas of surface complexes indicate the assumed location of constituents of the complex in the electrical triple layer. The entire surface complex is located directly on the surface unless a dash is present in the formula. If a dash is present, everything to the left of the dash is located on the surface, and everything to the right of the dash is located in the OHP. 

Table I. Reactions and Selected Intrinsic Equilibrium Constants for Surface Ionization and Electrolyte Adsorption...

The differential selectivity/intrinsic selectivity relationship here is shown in Figure 1.9. 

Table 3.10 Selected intrinsic viscosity-molecular weight relationship, [ ] = KM% (77)...

The selectivity of an electrophile, measured by the extent to which it discriminated either between benzene and toluene, or between the meta- and ara-positions in toluene, was considered to be related to its reactivity. Thus, powerful electrophiles, of which the species operating in Friedel-Crafts alkylation reactions were considered to be examples, would be less able to distinguish between compounds and positions than a weakly electrophilic reagent. The ultimate electrophilic species would be entirely insensitive to the differences between compounds and positions, and would bring about reaction in the statistical ratio of the various sites for substitution available to it. The idea has gained wide acceptance that the electrophiles operative in reactions which have low selectivity factors Sf) or reaction constants (p+), are intrinsically more reactive than the effective electrophiles in reactions which have higher values of these parameters. However, there are several aspects of this supposed relationship which merit discussion. 

All that can be concluded from the data given in the preceding example is that the particle is not an unsolvated sphere. However, when an appropriate display of contours is examined for f/fo (e.g.. Ref. 2), the latter is found to be consistent with an unsolvated particle of axial ratio about 4 1 or with a spherical particle hydrated to the extent of about 0.48 g water (g polymer). Of course, there are a number of combinations of these variables which are also possible, and some additional experimental data—such as the intrinsic viscosity—are needed to select that combination which is consistent with all experimental observations. 

Among the current (ca 1997) selection of software systems which together help to exemplify the promise of computer graphics. Advanced Visualization Systems (AVS), stands out as one of the more extensible and practical of them to use. The premise behind development of the system was to provide modelers with a toolkit of modules having sophisticated intrinsics that would enable even casual programmers to link together multiple simple functionahties into a complex constmct with which to accomplish exactly the types of visualization and manipulations that their work required. Researchers... 

For an equiUbrium-based separation, a convenient measure of the intrinsic selectivity of the adsorbent is provided by the separation factor which is defined by analogy with the relative volatility as... 

The properties of fillers which induence a given end use are many. The overall value of a filler is a complex function of intrinsic material characteristics, eg, tme density, melting point, crystal habit, and chemical composition and of process-dependent factors, eg, particle-si2e distribution, surface chemistry, purity, and bulk density. Fillers impart performance or economic value to the compositions of which they are part. These values, often called functional properties, vary according to the nature of the appHcation. A quantification of the functional properties per unit cost in many cases provides a vaUd criterion for filler comparison and selection. The following are summaries of key filler properties and values. 

Fabric Composition. The method of fabric manufacture dictates many of the characteristics of the sheet, but intrinsic properties are firmly estabhshed by the base polymer selected. Properties such as fiber density, temperature resistance, chemical and light stabiUty, ease of coloration, surface energies, and others are a function of the base polymer. Thus, because nylon absorbs more moisture than polypropylene, spunbonded fabrics made from nylon are more water absorbent than fabrics of polypropylene. 

The intrinsic charge-generation efficiency of polymers is often low and needs to be enhanced by the addition of sensitizers. The sensitizer can be dissolved in the polymer to enhance the bulk charge-generation efficiency of the polymer. Effective sensitizers include 2,4,7-trinitro-9- uorenone [129-79-3] (TNF), hiUerene, thiapyryhum dye, CdS nanoclusters, etc (Table 3). Molecular stmctures of selected sensitizers are shown in Figure 8. 

The hydroformylation reaction is carried out in the Hquid phase using a metal carbonyl catalyst such as HCo(CO)4 (36), HCo(CO)2[P( -C4H2)] (37), or HRh(CO)2[P(CgH3)2]2 (38,39). The phosphine-substituted rhodium compound is the catalyst of choice for new commercial plants that can operate at 353—383 K and 0.7—2 MPa (7—20 atm) (39). The differences among the catalysts are found in their intrinsic activity, their selectivity to straight-chain product, their abiHty to isomerize the olefin feedstock and hydrogenate the product aldehyde to alcohol, and the ease with which they are separated from the reaction medium (36). 

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