Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Zero stability

Under most soil conditions it is the aerobic microflora that is responsible for the formation of aggregating substances, but Harris et al. (1963) showed that the anaerobic microorganisms also possess this ability. This is shown in Fig. 16.1, taken from their publication. In this experiment the stability of artificial sucrose-amended soil aggregates was determined under both aerobic and anaerobic conditions. Under aerobic conditions aggregate stability increased rapidly for 4 days to 80% and then fell nearly as rapidly to zero stability after 12 days. Under anaerobic conditions aggregate stability increased... [Pg.327]

Abstract Analytical methods used in testing pharmaceutical stability samples need to be validated to the current standards. Often the same methods are employed for release and stability testing which facilitates method validation and allows for the use of initial release data for time zero stability as long as samples are packaged and placed on stability in a reasonably short period of time (typically 30 days). Transfer of these methods between laboratories is also facilitated by the development and validation of the same methods for release and stability testing. Stability testing... [Pg.163]

In [215] the author developed a three-step seventh algebraic order hybrid linear multistep method (HLMM) with three non-step points for the approximate solution special of special second order initial value problems. The author produced the main method and additional methods from the same scheme derived via interpolation and collocation techniques. The local truncation error is presented, the zero stability and the convergence and consistency properties are studied. Numerical experiments show the efficiency of the proposed algorithm. [Pg.171]

In Table 3 some essential parameters are listed, which should be referred to in a manual, since they influence the performance of a spectrometer in addition to such common parameters as range, accuracy, and reproducibility of wavelength, stray light bandpass (spectral bandwidth or slit width of the spectrometer) photometric accuracy, reproducibility, and linearity baseline flatness absorbance zero stability noise level scan speeds response times and data intervals. Furthermore possible modes of the axis are of interest absorbance, transmittance, derivative, Kubelka-Munk function [9], and the possible scaling of the axis. Most of these parameters are given in manuals, determine the limitations of the instrument, and affect each other. [Pg.77]

For applications in corrosive fluids or at elevated temperature CDGs with ceramic diaphragm should preferably be used. AI2O3 is the best material for this application since it shows no creep after overloading and hence its zero stability is very good. Ceramic CDGs are nowadays available even for very low full-scale deflections below 1 mbar. [Pg.167]

By setting in (4.1.20) A = 0, one sees that the roots of the p-polynomial determine zero stability ... [Pg.109]

Example 4.1.11 Finally, we demonstrate zero stability of the two step Adams-Bashforth method (AB-2) by discretizing the unconstrained truck. In Fig. 4 4 seven largest eigenvalues of h) are traced as a function of the step size. [Pg.109]

In Fig. 4.8 the stability region of the three stage Radau Ila method is displayed. One realizes that the stability of the Radau method is much alike the stability of the implicit Euler method, though the three stage Radau method has order 5. Again we note the property i (0) = 1 which corresponds to zero stability in the multistep case. [Pg.131]

By decreasing the step size this instability is not removed. The two step Adams-Moulton method is like all higher order methods in this class not zero-stable when applied to index-2 or index-3 systems. We will give in Sec. 5.2.3 criteria for zero stability of multistep methods applied to index-2 systems. [Pg.152]

A simple demonstration that the quantum mechanical coupling of oscillating charges produces a non-zero stabilizing term is the Drude model see ref. [2], pp. 32-34. That some physical facts could only be explained by quantum mechanics (quantal fiat , see ref. [4], p. 200) was an epistemological scandal to many physicists of the early twentieth century. [Pg.115]

Calculations of mutual locations of poles and zeros for these TF models allow to trace dynamics of moving of the parameters (poles and zeros) under increasing loads. Their location regarding to the unit circle could be used for prediction of stability of the system (material behavior) or the process stationary state (absence of AE burst ) [7]. [Pg.192]

The first finite element schemes for differential viscoelastic models that yielded numerically stable results for non-zero Weissenberg numbers appeared less than two decades ago. These schemes were later improved and shown that for some benchmark viscoelastic problems, such as flow through a two-dimensional section with an abrupt contraction (usually a width reduction of four to one), they can generate simulations that were qualitatively comparable with the experimental evidence. A notable example was the coupled scheme developed by Marchal and Crochet (1987) for the solution of Maxwell and Oldroyd constitutive equations. To achieve stability they used element subdivision for the stress approximations and applied inconsistent streamline upwinding to the stress terms in the discretized equations. In another attempt, Luo and Tanner (1989) developed a typical decoupled scheme that started with the solution of the constitutive equation for a fixed-flow field (e.g. obtained by initially assuming non-elastic fluid behaviour). The extra stress found at this step was subsequently inserted into the equation of motion as a pseudo-body force and the flow field was updated. These authors also used inconsistent streamline upwinding to maintain the stability of the scheme. [Pg.81]

This experiment describes the determination of the stability (cumulative formation) constant for the formation of Pb(OH)3 by measuring the shift in the half-wave potential for the reduction of Pb + as a function of the concentration of OH . The influence of ionic strength is also considered, and results are extrapolated to zero ionic strength to determine the thermodynamic formation constant. [Pg.535]

Source All values are from Martell, A. E. Smith, R. M. Critical Stability Constants, Vol. 1-4. Plenum Press New York, 1976. Unless otherwise stated, values are for 25 °C and zero Ionic strength. Values In parentheses are considered less reliable. [Pg.739]

We now aim to study the stability of the solution with respect to the crack shape. Let y = 5 x) be the crack shape, and 5 be a parameter which will subsequently tend to zero. [Pg.145]

The decomposition of aqueous hydrogen peroxide is minimized by various purification steps during manufacture, use of clean passive equipment, control of contaminants, and the addition of stabilizers. The decomposition is zero-order with respect to hydrogen peroxide concentration. [Pg.472]

The maximum velocity at the axis is twice the average, whereas the velocity at the wall is zero. The effect of the burner wall is to cool the flame locally and decrease the burning velocity of the mixture. This results in flame stabilization. However, if the heat-transfer processes (conduction, convection, and radiation) involved in cooling the flame are somehow impeded, the rate of heat loss is decreased and the local reduction in burning velocity may no longer take place. This could result in upstream propagation of the flame. [Pg.523]


See other pages where Zero stability is mentioned: [Pg.241]    [Pg.570]    [Pg.221]    [Pg.44]    [Pg.397]    [Pg.274]    [Pg.118]    [Pg.241]    [Pg.305]    [Pg.97]    [Pg.109]    [Pg.178]    [Pg.176]    [Pg.241]    [Pg.570]    [Pg.221]    [Pg.44]    [Pg.397]    [Pg.274]    [Pg.118]    [Pg.241]    [Pg.305]    [Pg.97]    [Pg.109]    [Pg.178]    [Pg.176]    [Pg.224]    [Pg.2416]    [Pg.2679]    [Pg.2682]    [Pg.98]    [Pg.124]    [Pg.384]    [Pg.122]    [Pg.479]    [Pg.192]    [Pg.552]    [Pg.204]    [Pg.184]    [Pg.213]    [Pg.187]    [Pg.253]    [Pg.725]    [Pg.113]    [Pg.665]   
See also in sourсe #XX -- [ Pg.28 , Pg.112 , Pg.117 , Pg.147 , Pg.239 , Pg.258 , Pg.263 , Pg.301 ]




SEARCH



© 2024 chempedia.info