Product functions such as gn yield predictable results when measurements are... [Pg.569]

The use of oximes as nucleophiles can be quite perplexing in view of the fact that nitrogen or oxygen may react. Alkylation of hydroxylamines can therefore be a very complex process which is largely dependent on the steric factors associated with the educts. Reproducible and predictable results are obtained in intramolecular reactions between oximes and electrophilic carbon atoms. Amides, halides, nitriles, and ketones have been used as electrophiles, and various heterocycles such as quinazoline N-oxide, benzodiayepines, and isoxazoles have been obtained in excellent yields under appropriate reaction conditions. [Pg.307]

The first successhil use of lithium metal for the preparation of a i7j -l,4-polyisoprene was aimounced in 1955 (50) however, lithium metal catalysis was quickly phased out in favor of hydrocarbon soluble organ olithium compounds. These initiators provide a homogeneous system with predictable results. Organ olithium initiators are used commercially in the production of i7j -l,4-polyisoprene, isoprene block polymers, and several other polymers. [Pg.467]

For continuing polymerization to occur, the ion pair must display reasonable stabiUty. Strongly nucleophilic anions, such as C/ , are not suitable, because the ion pair is unstable with respect to THE and the alkyl haUde. A counterion of relatively low nucleophilicity is required to achieve a controlled and continuing polymerization. Examples of anions of suitably low nucleophilicity are complex ions such as SbE , AsF , PF , SbCf, BE 4, or other anions that can reversibly coUapse to a covalent ester species CF SO, FSO, and CIO . In order to achieve reproducible and predictable results in the cationic polymerization of THE, it is necessary to use pure, dry reagents and dry conditions. High vacuum techniques are required for theoretical studies. Careful work in an inert atmosphere, such as dry nitrogen, is satisfactory for many purposes, including commercial synthesis. [Pg.361]

Whereas the addition of early metal soaps to a coating for the specific purpose of improving the drying performance did so, the compounds lacked uniformity of composition and therefore did not give predictable results. Even if all of the metal reacted with the acid to give an expected metal ion concentration, which seldom happened, the ions were subject to oxidation, which resulted in loss of solubiUty in the vehicle and therefore a loss of activity. [Pg.217]

Treatment of benzo derivatives with oxidizing agents leads to less predictable results. Thus, substituted 2,1-benzisoxazoles with nitrous acid or with CrOs/AcOH generated a variety of ring-opened products of higher oxidation state, the ratio of which depended on the amount of oxidant. These reactions are illustrated in Scheme 30. [Pg.27]

It cannot be stated generally how accurate the predicted results are. Due to the limitations of geometric, physical, and mathematical modeling, not all of the produced numbers (e.g., air velocity vectors) are at a high level of accuracy, and the results are therefore subjected to experienced weighting. In some cases, the values can be as accurate as within 5% of the real values in other cases, they are not as accurate as could be wished. But results can be still very strong and helpful in a comparative judgment, i.e., if a number of similar case.s are compared with observed tendencies. [Pg.1031]

If the flow is isothermal, there is no need to solve for the temperature equation (Eq. (11.6)). In this case the last term in Eq. (11.5) is also dropped. If, however, the thermal comfort is simulated, then the temperature equation must be solved. In ventilation the temperature variations are normally small, which means that it is sufficient to account for density variation only in the gravitation term (the last term in Eq. (11.5)). The gravitation term acts in the vertical direction, and in Eq. (11.5) it is assumed that the xj coordinate is directed vertically upward. denotes a reference temperature, which should be constant. It does not influence the predicted results, except that the pressure level is changed. It could, however, affect convergence rate (i.e., increase the number of required iterations required to reach a converged solution), and it should be chosen to a reasonable value, such as the inlet temperature. [Pg.1034]

Declare the intention to utilize defined processes throughout the organization in order to achieve more predictable results. [Pg.94]

Predicted results for E2 are plotted in Figure 3-10 for three values of the fiber-to-matrix-modulus ratio. Note that if Vj = 1, the modulus predicted is that of the fibers. However, recognize that a perfect bond between fibers is then implied if a tensile <32 is applied. No such bond is implied if a compressive 02 is applied. Observe also that more than 50% by volume of fibers is required to raise the transverse modulus E2 to twice the matrix modulus even if E, = 10 x E ,l That is, the fibers do not contribute much to the transverse modulus unless the percentage of fibers is impractically high. Thus, the composite material property E2 is matrix-dominated. [Pg.130]

In the result of the simulation one expects the times r23 to be proportional to rR and to be proportional to rp, and, indeed, from Fig. 12 the respective power laws are nicely seen in the athermal case of neutral walls, e/k T = 0. Good agreement with predicted results (not shown graphically here) is obtained also for the scahng of with N, and with D [14]. [Pg.584]

Anderson and Brown then suggested that the effects observed by McAlevy (M3, M4) of oxygen on the ignition characteristics of solid fuels might be the result of exothermic heterogeneous reactions, since the experimental observations of McAlevy as well as those of Shannon and Anderson (S3), can be correlated by Eq. (15). Shannon has also extended the original treatment of Anderson and Brown to include the effects of adsorption and desorption on the predicted results. [Pg.18]

The method of the measurement pressure drop inside the channel itself should be used to check the overall agreement between experimental and predicted results. The internal pressure measurements should be used also to validate the entrance and... [Pg.90]

Both the frontier-orbital and the Mobius-Hiickel methods can also be applied to the cyclohexadiene 1,3,5-triene reaction in either case the predicted result is that for the thermal process, only the disrotatory pathway is allowed, and for the... [Pg.1429]

Thin him lubrication is essentially a transition lubrication regime between elastohydrodynamic lubrication and boundary lubrication regimes. Papers devoted to the investigations of this lubrication regime are not enough for engineering needs. In this section, a function to describe the viscosity distribution is proposed in order to attain predictive results and to describe the characteristics of TFL in the viewpoint of engineering. [Pg.72]

The values of the three electrochemical measurements, potential, resistance, and current were measured for the four coatings over time. The resultant time series for each measurement and coating combination were analyzed by the Box-Jenkins ARIMA procedure. Application of the ARIMA model will be demonstrated for the poly(urethane) coating. Similar prediction results were obtained for all coatings and measurements, however, not all systems were modeled by the same order of ARIMA process. [Pg.92]

Sodium diffusion coefficients in glass cullets calculated from fitting Eq. (10) with the profiles of sodium were 2.9 - 3.9><10 m /s at 823K (see Fig. 1). Comparison of experimental results with predicted results for Na neutralized with HCl at 823K was fairly consistent and indicated that Dns calculated would well represent the neutralization kinetics. [Pg.399]

Mathematical Models. As noted previously, a mathematical model must be fitted to the predicted results shown In each factorial table generated by each scientist. Ideally, each scientist selects and fits an appropriate model based upon theoretical constraints and physical principles. In some cases, however, appropriate models are unknown to the scientists. This Is likely to occur for experiments Involving multifactor, multidisciplinary systems. When this occurs, various standard models have been used to describe the predicted results shown In the factorial tables. For example, for effects associated with lognormal distributions a multiplicative model has been found useful. As a default model, the team statistician can fit a polynomial model using standard least square techniques. Although of limited use for Interpolation or extrapolation, a polynomial model can serve to Identify certain problems Involving the relationships among the factors as Implied by the values shown In the factorial tables. [Pg.76]

In quantum theory, identical particles must be indistinguishable in order for the theory to predict results that agree with experimental observations. Consequently, as shown in Section 8.1, the wave functions for a multi-particle system must be symmetric or antisymmetric with respect to the interchange of any pair of particles. If the wave functions are not either symmetric or antisymmetric, then the probability densities for the distribution of the particles over space are dependent on how the particles are labeled, a property that is inconsistent with indistinguishability. It turns out that these wave functions must be further restricted to be either symmetric or antisymmetric, but not both, depending on the identity of the particles. [Pg.217]

More recent theoretical work has raised questions about these conclusions, how-ever. Particularly extensive calculational treatment of the rearrangement of 54 to vinyl chloride by several research groups failed to duplicate the predictions of an atypical kinetic isotope effect. These later studies indicate that tunneling effects should indeed be greater for H-shift than for the heavier D rearrangement. Consequently, the k /ko ratio should actually decrease at higher temperatures. The discrepancy in predicted results was eventually traced to an error in the earlier calculations. Nevertheless, it... [Pg.443]

Compare the actual results with your predicted results. [Pg.89]

IX. USE OF IN VITRO MONOLAYER STUDIES TO PREDICT RESULTS IN VIVO... [Pg.325]

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