General utility

Gale J 1999. General Utility Lattice Program Manual, Imperial College, London. 

Although apparatus employing ground-glass joints is excellent for work on a macro scale, it is not always suitable for very small-scale work as the joints are often disproportionately large compared with the rest of the assembly. The semi-micro apparatus described on pp. 59-72 can therefore be considered as being of general utility for this scale of work, especially as the use of corks has been reduced to a minimum. 

In the case of l,4-ben2oquinone, the product is steam-distilled, chilled, and obtained in high yield and purity. Direct oxidation of the appropriate unoxygenated hydrocarbon has been described for a large number of ring systems, but is generally utilized only for the polynuclear quinones without side chains. A representative sample of quinone uses is given in Table 5. 

The ideal gas law is an example of a correlating expression that comes direcdy from experimental observations, but has theoretical significance. Despite its simplicity, the ideal gas law is an excellent estimation tool. Often, it is the first approximation in systems involving real gases of all types. Unfortunately for Hquids and soHds no laws of such general utility are available. 

The general utility of the light microscope is also recognized by its incorporation into so many other kinds of analytical instrumentation. Continued development of new composites and materials, together with continued trends in microminiaturization make the simple, classical polarized-light microscope the instrument of choice for any initial analytical duty. 

EPRI NP-5664 is a study based on interviews of personnel at 10 utilities and 15 NRC personnel regarding the usefulness of PSA (they use the term PRA - probabilistic risk assessment). The general utility motivation for using PSA is to demonstrate an acceptably low level of risk to the NRC. Some utilities applied PSA to individual systems, functions, or issues. These smaller [ir(>grams served to train a PSA cadre and introduce PSA to other utility personnel and management. 

Montanari and coworkers have been particularly active in this area. They have generally utilized crowns or cryptands having long arms attached to them. These lipophilic arms are typically terminated in a primary or secondary amino function which may serve as a nucleophile in the reaction with a chloromethylated polystyrene residue. 

Isolated tetrasubstituted double bonds do not react under these conditions and the saturation of trisubstituted double bonds is extremely slow, thus limiting the general utility of the method. This difference in reactivity is used to advantage for the selective deuteration of the -double bond in androsta-l,4-diene-3,17-dione (138). In homogeneous solution, saturation usually occurs from the a-side and consequently the deuterium labels are in... 

Photolytic epimerizations of this type would represent a potentially useful method of direct inversion of chiral centers. However, competition by numerous other intramolecular processes vide infra) frequently renders its more general utilization less practical. 

It is again clear that the two benefits of increased sensitivity and better resolution are both achieved, where these arise from zone compression and phase selectivity, respectively. However, since this mode of analysis is relatively new, it has yet to be tested for a wide range of applications such studies will be required to fully demonstrate its general utility. It is unclear whether this operational mode of selective MDGC constitutes a mode which is consistent with the definition of comprehensive... 

In the minds of many, especially those who have not had the opportunity to use it, catalytic hydrogenation has acquired an aura of mystery the choice of catalyst seems capricious, operating conditions arbitrary, catalyst preparation secret, and the working of the catalyst unfathomable. It is the purpose of this work to meet these objections to provide rationale for choice of catalyst and conditions to acquaint the reader with catalysts, equipment, and procedure and to impart the conviction that hydrogenation is a powerful, readily handled, broad-scoped procedure of general utility for synthesis in both laboratory and industrial plant. 

Table 8-5 indicates the wide variety of catalysts that can effect this type of disproportionation reaction, and Figure 8-7 is a flow diagram for the Phillips Co. triolefm process for the metathesis of propylene to produce 2-butene and ethylene. Anderson and Brown have discussed in depth this type of reaction and its general utilization. The utility with respect to propylene is to convert excess propylene to olefins of greater economic value. More discussion regarding olefin metathesis is noted in Chapter 9. 

Natural product total syntheses are particularly valuable when they are attended by the development of general utility methods of synthesis. In some instances, the successful completion of a natural product total synthesis requires the development and application of a new synthetic method. The total synthesis of erythronolide B by Corey et al. is one of these instances. The double activation macro-lactonization method was a fruitful innovation that was introduced in response to the challenge presented by the macrocyclic structures of the erythromycins. Several other methods to achieve the same objective, and numerous applications followed. 

Finally, this method is of general utility, for alkaline cleavage of analogously substituted hydantoins has given a series of substituted phenylpyruvic acids.12... 

The choice of the pulse sequence to use is of fundamental importance. We must decide carefully what information is required, and choose the right experiment to provide it. Although hundreds of 2D pulse sequences are now available for various experiments, only some have proven themselves to be of general utility. Only such proven techniques should be chosen to solve structural problems. 

We have presented above the derivation of eqns 38 and 39 in great detail because it includes expressions of general utility, in particular the variation of the eigenvectors (eqns 7 and 24) of an MO problem after Lowdin orthogonalization and the resulting variation of the population matrix P. The generalization to a Hamiltonian more complicated than that of eqn 19 is possible by following step by step the above derivation. 

Simple distillation. The assembly shown in Fig. II, 60,1 is of general utility for very volatile liquids the Liebig s condenser may be replaced by a double siudace condenser. 

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