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A Few Words of Caution

Amorphous polymer is one that has no crystalline component and there is no order or pattern to the distribution of the molecules. [Pg.392]

Apparent viscosity is the ratio of shear stress by shear rate which has not been corrected for entrance length effects in a capillary rheometer. [Pg.392]

Bams effect or die swell or extradate swell is the increase in diameter of the polymeric melt extrudate upon emergence from the die. [Pg.392]

Branched polymer is one in which the main chain in the molecular structure is attached with side chains, that is in contrast to a linear polymer. [Pg.392]

Breakage stretch ratio (BSR) is the ability of the polymer extruded from a die to vnUistand breakage when stretched at a particular rate on a draw roll system. [Pg.392]

Any errors in MFI measurements are likely to depict amplified derogatory results when correlating with other fundamental properties. Hence, it is worth using microprocessor-controlled melt flow indexers which are now available in the market, so that the highest order of accuracy and reliability can be maintained. The names and addresses of some of the leading manufacturers/suppliers of melt flow indexers from all over the world are given in Appendix D. [Pg.391]


A few words of caution may be appropriate in regard to the use of this concept, particularly for readers who did not major in chemistry. The pH of an aqueous solution is formally defined as follows ... [Pg.397]

When alkali-metal atoms are involved, either as reagents or products of reaction, a few words of caution regarding synthesis should be noted. Alkali-metal atoms may readily react... [Pg.280]

These points prompt a few words of caution regarding the results discussed in this section and some comments on theoretical results in general. In particular, besides considerations of the size and effect of basis sets, one needs to examine the energy dependence on electron correlation. For donor-acceptor complexes, such as Lewis acid-carbonyls, electron correlation seems to be crucial. It is also instructive to consider the dipole moments of various structures in theoretical studies. Assumption of a gas phase environment may overestimate destabilization due to a large dipole, as dipoles can often be stabilized quite effectively in solution. At times the interpretation of theoretical results are the source of trouble and confusion. Thus two different groups propound apparently conflicting and opposite views on the effect of Lewis acids on the carbonyl dipole. [Pg.291]

The fit of the last binary pair, the methane-octane system, is shown in figure 5.3. This fit was obtained with a value of kij equal to 0.01. A few words of caution are warranted in this case. As noted in chapter 3, methane-hydrocarbon mixtures are expected to deviate from type-I behavior if the methane-solute carbon ratio is greater than 5. The P-x data shown in figure 5.3 are far above the temperatures where a three-phase LLV line is expected for this binary system. However, a three-phase LLV line is predicted near the critical point of methane using A ,y equal to 0.01. [Pg.116]

Before going further, a few words of caution are required. Sterile work demands concentration, attention to detail and a steady hand. Work for reasonable periods of time and not to the point of exhaustion. Never leave a lit alcohol lamp or butane torch unattended and be conscious of the fact that in an airtight space oxygen can soon be depleted. [Pg.17]

A few words of caution are required, however. The estimate in vitro of brain/ blood concentration ratios is subject to many errors and has to be regarded as a gross approximatioa Although compounds are administered intravenously by infusion over an extended period (2-3 h) so that near steady state equilibrium is produced, they are subject to different rates of metabolism, elimination (excretion) and protein binding. All these factors will affect the concentration of drag available for brain penetration and will operate differently for each compound. In each case a check was made to determine the proportion of parent drag in the peripheral blood and in the brain by thin-layer chromatography. In most cases, the parent compound was still present at 90% for a few compounds, the proportion of parent present in the blood had decreased to 50%, so that the ratios for these could be underestimated by a factor of up to twofold with respect to metabohsm. [Pg.17]

In concluding this section, a few words of caution must be spoken in connection with the problem of redundancy. It was pointed out in Sec. 6-2 that in order to take advantage of symmetry, redundant coordinates should sometimes be employed. Naturally, the inclusion of such extra coordinates will result in the definition of redundant force constants. Phus when all six bending angles are used in the vibrational treatment of methane, three bending force constants can be defined, namely,... [Pg.291]

This is the last chapter of this book it has been induded in order to provide a forum for the authors to make some remarics of significance. It gives an opportunity to retrospect the ideas presented in the book and to draw conclusions in a systematic manner. The remarks are categorized under three subheadings, namely, comments on the presented work, suggestions for future woik, and a few words of caution. [Pg.383]

The final duqrter makes some concluding remain and gives sug stions for future w( so that researdiers interested in the field of thermqdastic melt rheology wfll be enticed to provide further insights. A few words of caution are... [Pg.472]

A few words of caution need to be interjected here, for OJ-MT Itself is able to produce a depressant condition when given in large doses. Moore et al 9 emphasize the toxic actions of 200-300 mg/kg doses of Ct-MT In single injections which result in a high frequency of deaths. Lethality is preceded by a state of depression, lethargy and hypothermia in rats associated with blood and organ abnormalities. [Pg.253]


See other pages where A Few Words of Caution is mentioned: [Pg.83]    [Pg.293]    [Pg.361]    [Pg.231]    [Pg.429]    [Pg.19]    [Pg.291]    [Pg.189]    [Pg.390]    [Pg.390]   


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A Few

A Word of Caution

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