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Function procedure

It must be emphasized that the availability of the SMO and 2D autocovariance function methods as two independent statistical procedures to estimate the same parameter, in, the number of proteins, is a helpful tool to verify the reliability of the results obtained. In the case of the 2D PAGE map of colorectal adenocarcinoma cell line (DL-1) an excellent agreement was found between the values obtained from the SMO method—m = 101 10 and m = 105 10—and the 2D autocovariance function procedure—m = 104 10 (Pietrogrande et al., 2006a). [Pg.85]

Although Eq. (3.1) is an exact formula for the electrostatic potential due to a set of nuclei ZA and an electronic density p(r), the latter [p(r)] is generally obtained computationally from an ab initio or semi-empirical wave function or, more recently, from density functional procedures and is therefore necessarily approximate. It follows that the resulting V(r) is also approximate. [Pg.54]

Chendra, A. K., and A. Goursot. 1996. Calculation of Proton Affinities Using Density Functional Procedures A Critical Study. J. Phys. Chem. 100,11596. [Pg.125]

Gas-phase heats of formation for tetraazapentalene derivatives 13-16 were computed using a density functional procedure. Optimized structures and relative energies were computed for the key molecular framework and several isomeric forms. The unexpected observed tetraazapentalene stability is explained by the relatively positive character of the triply coordinated nitrogens <1995JMT63>. [Pg.369]

Scheme 2 shows preparation of the biftinctional fiber. PPPE-c and PPPE-f grafted with CMS and ST were functionalized by the reported method.6 Here, an example of functionalization procedures is described. The precursory fibers (PPPE-f grafted with CMS and ST, 2 g) and triethyl phosphite (60 ml) were taken into a three-necked flask (200 ml) equipped with a Liebig condenser. After the mixture in the flask was heated for 48 h at 100 °C, the resulting phosphorylated PPPE-f was washed with acetone, aceton-water mixture and water, and dried in vacuum oven at 40 °C. In order to introduce sulfonic acid groups, the phosphorylated PPPE-f was treated with a 30 mL of 1,2-dichloroethane solution of chlorosulfonic acid (10 wt %) for 2 h at room temperature. Finally, diethyl phosphonate groups on the fibers were hydrolyzed with 12 M hydrochloric acid under refluxed... [Pg.54]

A good understanding of the chemical properties of CNTs is mandatory for enhancing the efficiency of practical devices and also for comprehending related fundamental processes such as their electrochemistry. In the following, we will address the chemical reactivity of CNTs and in Section 3.3.3, the different (bio) chemical functionalization procedures that can be performed for applications, will be discussed in more detail. [Pg.121]

The set of molecular orbitals leading to the lowest energy are obtained by a process referred to as a self-consistent-field or SCF procedure. The archetypal SCF procedure is the Hartree-Fock procedure, but SCF methods also include density functional procedures. All SCF procedures lead to equations of the form. [Pg.25]

A density functional procedure has been used to compute the gas-phase heat of formation of the triazolooxadiazole 17, and the calculated value of Ai/f° at 202 kcal moP (903 cal is more than 4 times greater than that of a leading military explosive, l,3,5-trinitrohexahydro-l,3,5-triazine (RDX), 18 (206cal g ), which supports the hypothesis that a high energy content is associated with nitrogen catenation <1995JST(358)63>. [Pg.199]

Chen s analysis is more accurate than the procedure in which the Onsager trial function is used with a(N) given by Eq. (18), but it is very involved to carry through. On the other hand, the Onsager trial function procedure is simple enough for practical purposes. As shown in Appendix A, it predicts the isotropic-nematic phase boundary concentrations that can be favorably compared with those by Chen s procedure. [Pg.98]

Fig. Al. Comparison of the reduced phase boundary concentrations (ch cA) obtained by Chen s procedure [47] and the Onsager trial function procedures for f (a)... Fig. Al. Comparison of the reduced phase boundary concentrations (ch cA) obtained by Chen s procedure [47] and the Onsager trial function procedures for f (a)...
Graessley and his co-workers have made calculations of the effects of branching in batch polymerizations, with particular reference to vinyl acetate polymerization, and have considered the influence of reactor type on the breadth of the MWD (89, 91, 95, 96). Use was made of the Bamford and Tompa (93) method of moments to obtain the ratio MJMn, and in some cases the MWD by the Laguerre function procedure. It was found (89,91) that narrower distributions are produced in batch (or the equivalent plug-flow) systems than in continuous systems with mixing, a result referrable to the wide distribution of residence times in the latter. [Pg.30]

The second protonation of dimethylaminopyridines and their N-oxides, all weak bases whose pK determination involves acidity function theory, yield o values in good agreement with previous values, affording thereby a check on the validity of the acidity function procedure. [Pg.12]

Kupperman et a/.223-228 compared transition-state, classical, and quantum mechanical thermal rate constants using the SSMK surface.112 In ab initio potential energy surface calculations, the potential energy is known only as a list of values at selected geometries of the system. It becomes necessary, then, if trajectory calculations are to be made, to fit the calculated points to a smooth and continuous map . In their calculations, Kupperman et al. fit the collinear SSMK surface by the rotating Morse function procedure of Wall and Porter.227... [Pg.54]

A radical formed upon homolytic cleavage of a functional initiator carries the corresponding function. Since upon initiation the primary radical adds to a monomer, this functional group remains attached to the formed polymer molecule. However, this functionalization procedure is far from being adequate for the following reasons — Functionalization at only one chain end requires that termination occurs exclusively by disproportionation (and not by recombination) and that transfer reaction of the radical to monomer and to solvent molecules can be disregarded. If the first condition is not fulfilled, functionalization at both chain ends can result. If the second condition is not valid, only a fraction of the formed macromolecules is functionalized, namely those arising from primary radicals. [Pg.30]

It should be noted at this point that there is a consistency in the pKa values measured in pure DMSO by the various techniques. However, there is some uncertainty at present relating to pKa values obtained by acidity function procedures in alcoholic and aqueous DMSO media. Thus one has the unexpected situation that theoretical analysis of the medium effect on p/ a is hampered because the values for a number of weak acids referring to the standard state in water are in doubt. Under these circumstances less than critical application of (6) to many weak acids, including some carboxylic acids, phenols as well as carbon acids, is inadvisable. Of course, (6) is strictly applicable to those cases in which the p/sfa values can be measured in the pure hydroxylic solvents and also for those weak acids which obey the criteria outlined by Cox and Stewart (1976). Despite this difficulty there is now a large body of reliable pKa data in both DMSO and water. Thus in principle it should be possible to account for variations, or reversals, in acidity order in terms of the thermodynamic transfer functions in (6). [Pg.149]

The focus will lai gely be on cases in which the functionalization or oxidation is performed with geometric control, and in which that control permits selective attack at various predetermined positions remote from any functional groups of the substrate. Those methods in which oxidations, using geometric direction, occur in the near neighborhood of substrate functional groups will also be discussed briefly. Such methods were an important source of inspiration for the more remote functionalization procedures, and they perform many useful transformations. [Pg.40]

A number of other proton transfer reactions from carbon which have been studied using this approach are shown in Table 8. The results should be treated with reserve as it has not yet been established fully that the derived Bronsted exponents correspond exactly with those determined in the conventional way. One problem concerns the assumption that the activity coefficient ratios cancel, but doubts have also been raised by one of the originators of the method that, unless solvent effects on the transition state are intermediate between those on the reactants and products, anomalous Bronsted exponents will be obtained [172(c)]. The Bronsted exponents determined for menthone and the other ketones in Table 8 are roughly those expected by comparison with the values obtained for ketones using the conventional procedure (Table 2). For nitroethane the two values j3 = 0.72 and 0.65 which are shown in Table 8 result from the use of different H functions determined with amine and carbon acid indicators, respectively. Both values are roughly similar to the values (0.50 [103], 0.65 [104]), obtained by varying the base catalyst in aqueous solution. The result for 2-methyl-3-phenylpropionitrile fits in well with the exponents determined for malononitriles by general base catalysis but differs from the value j3 0.71 shown for l,4-dicyano-2-butene in Table 8. This latter result is also different from the values j3 = 0.94 and 0.98 determined for l,4-dicyano-2-butene in aqueous solution with phenolate ions and amines, respectively. However, the different results for l,4-dicyano-2-butene are to be expected, since hydroxide ion is the base catalyst used in the acidity function procedure and this does not fit the Bronsted plot observed for phenolate ions and amines. The primary kinetic isotope effects [114] also show that there are differences between the hydroxide ion catalysed reaction (feH/feD = 3.5) and the reaction catalysed by phenolate ions (kH /kP = 1.4). The result for chloroform, (3 = 0.98 shown in Table 8, fits in satisfactorily with the most recent results for amine catalysed detritiation [171(a)] from which a value 3 = 1.15 0.07 was obtained. [Pg.159]

CPF Coupled Pair Functional procedure for including dynamic electron correlation. [Pg.393]

It is interesting to compare the memory function procedure with the well known Gordon algorithm. In order to facilitate comparison with our method, we report it with an inessential change of rows and columns. The Gordon algorithm can be summarized as follows. [Pg.107]

Product-Difference Memory Function Procedure for Evaluating the Parameters of the Continued Fraction Expansioif Starting from the Moments - (1/3)6" [l-K-iTI... [Pg.158]

You can create two different kinds of macro Sub procedures, often called command macros, and Function procedures, called function macros, custom function macros, or user-defined functions. Although these procedures can use many of the same set of VBA commands, they are distinctly different. [Pg.241]


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