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Analysis of the Experimental Data

Various Langmiiir-Hinshelwood mechanisms were assumed. GO and GO2 were assumed to adsorb on one kind of active site, si, and H2 and H2O on another kind, s2. The H2 adsorbed with dissociation and all participants were assumed to be in adsorptive equilibrium. Some 48 possible controlling mechanisms were examined, each with 7 empirical constants. Variance analysis of the experimental data reduced the number to three possibilities. The rate equations of the three reactions are stated for the mechanisms finally adopted, with the constants correlated by the Arrhenius equation. [Pg.2079]

Heat transfer in micro-channels occurs under superposition of hydrodynamic and thermal effects, determining the main characteristics of this process. Experimental study of the heat transfer in micro-channels is problematic because of their small size, which makes a direct diagnostics of temperature field in the fluid and the wall difficult. Certain information on mechanisms of this phenomenon can be obtained by analysis of the experimental data, in particular, by comparison of measurements with predictions that are based on several models of heat transfer in circular, rectangular and trapezoidal micro-channels. This approach makes it possible to estimate the applicability of the conventional theory, and the correctness of several hypotheses related to the mechanism of heat transfer. It is possible to reveal the effects of the Reynolds number, axial conduction, energy dissipation, heat losses to the environment, etc., on the heat transfer. [Pg.185]

The precision stated in Table 10 is given by the standard deviations obtained from a statistical analysis of the experimental data of one run and of a number of runs. These parameters give an indication of the internal consistency of the data of one run of measurements and of the reproducibility between runs. The systematic error is far more difficult to discern and to evaluate, which causes an uncertainty in the resulting values. Such an estimate of systematic errors or uncertainties can be obtained if the measuring method can also be applied under circumstances where a more exact or a true value of the property to be determined is known from other sources. [Pg.157]

In the kinetic analysis of the experimental data with an autoclave, the non-linear least square method was used to estimate the rate constants under nonisothermal conditions. The simulation of liquefaction calculated by substituing the estimated values into the rate equations showed good agreement with experimental values. [Pg.225]

Methods based on simplification of the reaction rate expression. In these approaches one uses a vast excess of one or more of the reactants or stoichiometric ratios of the reactants in order to permit a partial evaluation of the form of the rate expression. They may be used in conjunction with either a differential or integral analysis of the experimental data. [Pg.41]

Hence, the heat capacity can be obtained with a fit from the derivatives of the temperatures. In the dual slope method, the analysis of the experimental data is quite complex, but there are two advantages the range of temperature can be wide and the explicit knowledge of G(T) is not necessary. [Pg.286]

Chen et al. [54] have reported a model for the assessment of the combined effects of the intrinsic reaction kinetics and dye diffusion into phosphorylated polyvinyl alcohol (PVA) gel beads. The analysis of the experimental data in terms of biofilm effectiveness factor highlighted the relevance of intraparticle diffusion to the effective azo-dye conversion rate. On the basis of these results, they have identified the optimal conditions for the gel bead diameter and PVA composition to limit diffusion resistance. [Pg.119]

Ideal reactors can be classified in various ways, but for our purposes the most convenient method uses the mathematical description of the reactor, as listed in Table 14.1. Each of the reactor types in Table 14.1 can be expressed in terms of integral equations, differential equations, or difference equations. Not all real reactors can fit neatly into the classification in Table 14.1, however. The accuracy and precision of the mathematical description rest not only on the character of the mixing and the heat and mass transfer coefficients in the reactor, but also on the validity and analysis of the experimental data used to model the chemical reactions involved. [Pg.481]

Since the phenoxyls possess an S = ground state, they have been carefully studied by electron paramagnetic spectroscopy (EPR) and related techniques such as electron nuclear double resonance (ENDOR), and electron spin-echo envelope modulation (ESEEM). These powerful and very sensitive techniques are ideally suited to study the occurrence of tyrosyl radicals in a protein matrix (1, 27-30). Careful analysis of the experimental data (hyperfine coupling constants) provides experimental spin densities at a high level of precision and, in addition, the positions of these tyrosyls relative to other neighboring groups in the protein matrix. [Pg.155]

The studies on the performance of effervescent atomizer have been very limited as compared to those described above. However, the results of droplet size measurements made by Lefebvre et al.t87] for the effervescent atomizer provided insightful information about the effects of process parameters on droplet size. Their analysis of the experimental data suggested that the atomization quality by the effervescent atomizer is generally quite high. Better atomization may be achieved by generating small bubbles. Droplet size distribution may follow the Rosin-Rammler distribution pattern with the parameter q ranging from 1 to 2 for a gas to liquid ratio up to 0.2, and a liquid injection pressure from 34.5 to 345 kPa. The mean droplet size decreases with an increase in the gas to liquid ratio and/or liquid injection pressure. Any factor that tends to impair atomization quality, and increase the mean droplet size (for example, decreasing gas to liquid ratio and/or injection pressure) also leads to a more mono-disperse spray. [Pg.275]

Fig. 4.16 Time evolution of the mean squared displacement (r ) (empty circle) at 363 K and the non-Gaussian parameter 2 obtained from the simulations at 363 K (filled circle) for the main chain protons of PL The solid vertical arrow indicates the position of the maximum of 2> At times r>r(Qinax)> the crossover time, a2 assumes small values, as in the example shown by the dotted arrows. The corresponding functions (r ) and a2 are deduced from the analysis of the experimental data at 320 K in terms of the jump anomalous diffusion model and are displayed as solid lines for (r )and dashed-dotted lines for a2- (Reprinted with permission from [9]. Copyright 2003 The American Physical Society)... Fig. 4.16 Time evolution of the mean squared displacement (r ) (empty circle) at 363 K and the non-Gaussian parameter 2 obtained from the simulations at 363 K (filled circle) for the main chain protons of PL The solid vertical arrow indicates the position of the maximum of 2> At times r>r(Qinax)> the crossover time, a2 assumes small values, as in the example shown by the dotted arrows. The corresponding functions (r ) and a2 are deduced from the analysis of the experimental data at 320 K in terms of the jump anomalous diffusion model and are displayed as solid lines for (r )and dashed-dotted lines for a2- (Reprinted with permission from [9]. Copyright 2003 The American Physical Society)...
Biscarbene 34 was characterized by IR and UV/vis spectroscopy [49], The analysis of the experimental data showed that these are compatible with the presence of two phenylchlorocarbene (6) subunits in 34. This interpretation was further supported by the reactivity behavior of 34, which, like 6, is unreactive toward oxygen under conditions where triplet carbenes react fast. In contrast to its para isomer (22), 34 appears to undergo photochemical ring expansion analogous to that of 6[105]. In addition, the computed [RHF/6-31G(d)] IR spectrum of 34, which is in good agreement with the observed one, is based on the wave function for the singlet (cr /cr ) biscarbene (54 of Fig. 9). [Pg.163]

Ideally, the enzyme solution to be added to the reaction solution should be likewise thermally equilibrated prior to initiating the reaction. However, the thermal instability of many enzymes may require their storage in an ice bucket. An aliquot of the cold enzyme can then be brought up to temperature just prior to the initiation of the reaction. If the enzyme solution cannot be prewarmed, then care has to be exercised in the analysis of the experimental data. For example, assume that an enzyme had a temperature dependency (Qio) of two (i.e., for every 10°C change in temperature, there is a twofold change in reaction rate). Thus, if a 0.1 mL aliquot of enzyme at 0°C is added to a reaction mixture of 3.0 mL at 30°C, the reaction velocity may be perturbed by as much as 20%. In such cases, the initial velocity should only be measured after the ongoing reaction has reached thermal equilibration. [Pg.671]

The statistical techniques associated with response surface methodology are concerned primarily with two aspects of the experimentation process the construction of experimental designs that yield data to permit the efficient modeling of the response surfaces, and the analysis of the experimental data and derived response surfaces. [Pg.18]

Only the value of the leading coefficient in the low energy expansion of the hadronic vacuum polarization is needed for calculation of the hadronic contribution to the Lamb shift (see the LHS of (3.32)). A model independent value of this coefficient may be obtained for the analysis of the experimental data on the low energy e+e annihilation. Respective contribution to the 15 Lamb shift [39] is —3.40(7) kHz. This value is compatible but more accurate than the result in (3.32). ... [Pg.33]

A compatible result for this contribution to the isotope shift was obtained from the analysis of the experimental data on the proton and deuteron structure functions in [37]. [Pg.121]

Such a conclusive consideration is certainly speculative. Nevertheless, it may be acceptable because of the detailed analysis of the experimental data. When each of the PLA, PDA, PG, PLIL and PLV samples was treated under the same conditions as in the individual cases of their blends as described above, the structure of polypeptides after its treatment did not change from the original structure as seen from the 13C CP/MAS NMR experiments. On the other hand, the structure of blended polypeptides after the treatment changes significantly. Therefore, it can be said that such a change comes from intermolecular interactions. [Pg.27]

The number of levels of any one factor which should be Included in the experimental design will depend largely on the following considerations 1) the research objectives (Is this factor of primary Interest in this research ), 2) the degree of certainty attached to current knowledge of the effects of the factor, and 3) the degree of probability that this factor interacts with other factors, which are definitely of primary interest, to determine the levels of the functional property (or properties) to be studied. Setting the level of an Important causative factor at an arbitrary point(s) could seriously bias results of analysis of the experimental data. [Pg.301]

The usual analysis of the experimental data consists of the measurement of the quantum efficiency versus electrical field and comparing the results with results theoretically calculated for different values of the parameters r0> e, T. [Pg.10]

Kinetic analysis of the experimental data was attempted using a simplified reaction scheme, although the actual reaction mechanism is rather complicated, as proposed by Semenov. We are convinced of the availability of such method for interpreting the reaction and for chemical plant design calculations. [Pg.344]

The stereochemistry at silicon is extremely sensitive to the nature of the nucleophiles (Tables I, II, and VI). As a consequence, the stereoselectivity, i.e., either percentage of RN or percentage of IN, is a quite sensitive and reliable measure of the dependence of the mechanism upon small changes in the structure of the anion, the metal, or the solvent. The analysis of the experimental data can take the following form ... [Pg.278]

One of the interesting results of the work presented in ref. 27 is the conclusion that the parameter y depends not only on the properties of the donor, but also on those of the acceptor. Analysis of the experimental data shows that, for many electron tunneling reactions, the parameter y depends rather strongly upon the nature of the acceptor (see Chaps. 6 and 7). However, strictly speaking, it is not possible to conclude that this is the consequence only of non-adiabatic effects since the parameter y can also depend on the properties of the acceptor within the scope of the traditional description of the electron tunnel transfer (see Sect. 4). [Pg.104]

Analysis of the experimental data accumulated indicates the rate of formation of pyrroles, which can roughly be estimated by the amount of products formed for the standard time, is approximately in a direct relationship to the acetylene pressure. Since this relationship is typical for many processes of the liquid-gas type, the questions of how fast the synthesis of pyrroles proceeds under an excess pressure of about 1.5 atm and whether this is acceptable from the viewpoint of technology are of utmost importance. [Pg.197]


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Analysis of data

Analysis of experimental data

Analysis of the data

Experimental analysis

The Data

The Experimental Data

The experimental analysis

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