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Ordinary parameter significance

As already noted, the main merit of fibers used as a filler for conducting composite materials is that only low threshold concentrations are necessary to reach the desired level of composite conductivity. However, introduction of fiber fillers into a polymer with the help of ordinary plastic materials processing equipment presents certain difficulties which are bound up mainly with significant shearing deformations entailing fiber destruction and, thereby, a decrease of parameter 1/d which determines the value of the percolation threshold. [Pg.138]

The basic SFC system comprises a mobile phase delivery system, an injector (as in HPLC), oven, restrictor, detector and a control/data system. In SFC the mobile phase is supplied to the LC pump where the pressure of the fluid is raised above the critical pressure. Pressure control is the primary variable in SFC. In SFC temperature is also important, but more as a supplementary parameter to pressure programming. Samples are introduced into the fluid stream via an LC injection valve and separated on a column placed in a GC oven thermostatted above the critical temperature of the mobile phase. A postcolumn restrictor ensures that the fluid is maintained above its critical pressure throughout the separation process. Detectors positioned either before or after the postcolumn restrictor monitor analytes eluting from the column. The key feature differentiating SFC from conventional techniques is the use of the significantly elevated pressure at the column outlet. This allows not only to use mobile phases that are either impossible or impractical under conventional LC and GC conditions but also to use more ordinary... [Pg.206]

Now, the parameter A has to be determined by a variation method. For those values of R for which A turns out to be 1, we can say that the ordinary m.o. is a valid type of approximation but for those values for which A differs considerably from 1, we interpret the significance of the wave function (8) to be that the repulsion between the electrons, tending to separate them on to different nuclei, is stronger than the additional attraction which arises when both electrons are under the influence of two nuclei. [Pg.140]

ErH2 -> Er). Then diffusion may be considered as relatively fast and therefore ordinary differential equations are sufficient. This significantly simplifies solving the inverse problems of parameter identification. Although models with fast diffusion may also correspond to the low-temperature flux peak atoms of H easily diffuse in ErH2 (may be, even easier than in Er even at higher temperatures). [Pg.620]

Numerous reports are available [19,229-248] on the development and analysis of the different procedures of estimating the reactivity ratio from the experimental data obtained over a wide range of conversions. These procedures employ different modifications of the integrated form of the copolymerization equation. For example, intersection [19,229,231,235], (KT) [236,240], (YBR) [235], and other [242] linear least-squares procedures have been developed for the treatment of initial polymer composition data. Naturally, the application of the non-linear procedures allows one to obtain more accurate estimates of the reactivity ratios. However, majority of the calculation procedures suffers from the fact that the measurement errors of the independent variable (the monomer feed composition) are not considered. This simplification can lead in certain cases to significant errors in the estimated kinetic parameters [239]. Special methods [238, 239, 241, 247] were developed to avoid these difficulties. One of them called error-in-variables method (EVM) [239, 241, 247] seems to be the best. EVM implies a statistical approach to the general problem of estimating parameters in mathematical models when the errors in all measured variables are taken into account. Though this method requires more information than do ordinary non-linear least-squares procedures, it provides more reliable estimates of rt and r2 as well as their confidence limits. [Pg.61]

So how does this look in the chemical industry More so than in many other industries, investors generally accept that social and environmental issues can be financially significant in the chemical industry, but within traditional parameters. Most chemical industry analysts lack training in how to analyze the financial impact of social and environmental considerations in the industry. It is not an ordinary or systematic part of what they consider. There are no accepted standards for when these issues are and are not important and there is no accepted means of integrating and understanding social and environmental issues into financial analysis. [Pg.446]


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Parameter significance

Significant parameters

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