Big Chemical Encyclopedia

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

Articles Figures Tables About

Realistic conditions

In the case where just two B-splines are involved, we see directly from the above that for 0 c 1 the scheme will be positive. [Pg.151]

It is also clear from the first necessary condition that the coefficient of the widest B-spline needs to be positive in this case c 0. Otherwise the extreme entries in the mask would be negative31. [Pg.151]

Above c = 1 we need to resort to numerical methods, and we may just as well go direct to what really matters, the / , norm, which dictates by how much the bounding box must be expanded.. Because the loo norm depends on the number of a factors, we present the result as a set of graphs, covering the cases 2 d 6. [Pg.151]

31For situations with more B-splines involved there is a more complicated rule covering the case where the coefficient of the widest B-spline is zero. [Pg.151]

If a certain value of Z is regarded as acceptable, the bounds on c for a given number, d, of a factors can be read off. The facetting is not an artifact of the plotting the curves for c 0 really are piecewise linear, and so exact bounds for given values of d and Zoo are accessible. [Pg.152]


The measurement procedure must have been tested previously under realistic conditions and should give representative results of worker exposure. Thus, it should not be influenced by unusual work schedules, where tasks may not be well defined or planned. The procedure should include... [Pg.370]

Because these data are peculiar to the supports studied, it can serve only as a good estimate for other situations. It is important to remember that the results obtained with a bare plate, and one holding a layer of packing, can be quite different, the latter being the more realistic condition. [Pg.312]

G. Yaluris and A. W. Peters, Studying the Chemistry of the Fi Regenerator in the Laboratory Under Realistic Conditions, Grace Dav Columbia, MD, 1998. [Pg.124]

Figure 13 shows the relation between the solubilization parameter and optimal salinity for three AOS surfactants under realistic conditions (50°C, brine for-... [Pg.396]

The simplest evaluation value of the complex (Ec/Re) (AReZ) shows that it is essentially smaller than unity for the realistic conditions typical for water flow in micro-channels Re 10, 100 pm, L 500. [Pg.130]

When (Xfpi )/ ((Z-Xf)pL) > 1 the integral (10.40) is much smaller than the integral (10.41) and it can be neglected. This inequality is fulfilled for the majority of physically realistic conditions when Xf > L 10. ... [Pg.411]

The reaction in Equation (7.23) is feasible as written but certainly not at temperatures as low as 25°C, and it must be adjusted for more realistic conditions. The adjustment for temperature uses... [Pg.233]

Situation Two different strengths of plastic foil are in evaluation for the packaging of a moisture-sensitive product. Information concerning the diffusion of water vapor through such foils is only sparsely available for realistic conditions. To remedy this lack of knowledge, samples of the product are sealed into pouches of either foil type and are subjected to the following tests ... [Pg.199]

We have discussed simulations that were intended to elucidate aspects of crystal growth under diverse conditions. In most cases a direct simulation of growth using realistic conditions is impractical. The growth rate may be many orders of magnitude slower than that required to produce observable crystalline material in the available computer time. We have described several methods to obtain information about the crystallization process in this situation. [Pg.235]

We have already mentioned that fundamental studies in catalysis often require the use of single crystals or other model systems. As catalyst characterization in academic research aims to determine the surface composition on the molecular level under the conditions where the catalyst does its work, one can in principle adopt two approaches. The first is to model the catalytic surface, for example with that of a single crystal. By using the appropriate combination of surface science tools, the desired characterization on the atomic scale is certainly possible in favorable cases. However, although one may be able to study the catalytic properties of such samples under realistic conditions (pressures of 1 atm or higher), most of the characterization is necessarily carried out in ultrahigh vacuum, and not under reaction conditions. [Pg.166]

Determine the stability of the catalyst How fast does it lose its activity and what is the cause of the deactivation How sensitive is the catalyst to various impurities that may be present in the feedstock under realistic conditions ... [Pg.205]

Under realistic conditions a balance is secured during current flow because of additional mechanisms of mass transport in the electrolyte diffusion and convection. The initial inbalance between the rates of migration and reaction brings about a change in component concentrations next to the electrode surfaces, and thus gives rise to concentration gradients. As a result, a diffusion flux develops for each component. Moreover, in liquid electrolytes, hydrodynamic flows bringing about convective fluxes Ji j of the dissolved reaction components will almost always arise. [Pg.20]

This point can be easily calculated from the adsorption equilibrium of each adsorbent. As shown in Figures 2 and 3 the linear approximation gives a sufficient accurate estimates ( 5% of the experimental values) within a range of realistic conditions to predict Tout and xout under given de- and adsorption conditions for each adsorbent [4],... [Pg.404]

Abstract A review is provided on the contribution of modern surface-science studies to the understanding of the kinetics of DeNOx catalytic processes. A brief overview of the knowledge available on the adsorption of the nitrogen oxide reactants, with specific emphasis on NO, is provided first. A presentation of the measurements of NO, reduction kinetics carried out on well-characterized model system and on their implications on practical catalytic processes follows. Focus is placed on isothermal measurements using either molecular beams or atmospheric pressure environments. That discussion is then complemented with a review of the published research on the identification of the key reaction intermediates and on the determination of the nature of the active sites under realistic conditions. The link between surface-science studies and molecular computational modeling such as DFT calculations, and, more generally, the relevance of the studies performed under ultra-high vacuum to more realistic conditions, is also discussed. [Pg.67]

For all the above studies, the cycle time used for rich and lean phase, 15 and 30 min, respectively, was long and far from being realistic. In addition to such long cycle studies, to get an estimate of the catalyst performance under realistic conditions, we have also done second type of studies known as short cycle studies. In these studies, the total cycle time was kept relatively short ( s) to simulate the actual exhaust conditions, and... [Pg.348]

Hendershot, R.J., Lasko, S.S., Fellmann, M.-F. et al. (2003) A novel reactor system for high throughput catalyst testing under realistic conditions. Appl. Catal. A Gen., 254, 107. [Pg.357]

Based upon the activity and electrochemical experimental results the 5%Pt,l%Bi/C catalyst was chosen for further detailed evaluation. For the catalyst to be effective in industrial applications it is desirable that it should remain active for a number of reaction cycles. The recycle capability of 5%Pt,l%Bi/C was evaluated under realistic conditions for a number of selective oxidation reactions, see Table 3. [Pg.419]

The deposition of sub-micron aerosols in a hollow cast of human bronchi has recently been measured under realistic conditions (Cohen et al., in press). Typical data are shown in Figure 4. These are inconsistent with convective enhancement of deposition but support the classical treatment of deposition by diffusion (Chamberlain and Dyson, 1956). [Pg.405]

Small angle scattering experiments are particularly well suited for in situ studies under realistic conditions [3], because they do not require quenching procedures of the reaction mixture, like TEM [4], NMR or EPR studies. [Pg.54]

Studies on Supported Catalysts at More Realistic Conditions... [Pg.62]


See other pages where Realistic conditions is mentioned: [Pg.80]    [Pg.288]    [Pg.134]    [Pg.51]    [Pg.1149]    [Pg.355]    [Pg.144]    [Pg.136]    [Pg.654]    [Pg.133]    [Pg.446]    [Pg.61]    [Pg.413]    [Pg.170]    [Pg.696]    [Pg.345]    [Pg.79]    [Pg.65]    [Pg.414]    [Pg.56]    [Pg.85]    [Pg.90]    [Pg.92]    [Pg.191]    [Pg.209]    [Pg.215]    [Pg.176]    [Pg.383]    [Pg.35]    [Pg.74]   


SEARCH



Realistic

Realists

© 2024 chempedia.info