Changing appearance

Key changes appear at the beginning and at the end The changes m Chapter 1 are major and send ripples through the book Chapter 28 is new... 

Free-swelling tests are commonly used to measure a coal s caking characteristics. A sample of coal is packed in a cmcible or tube, without compaction, and heated at a fixed rate to about 800°C. Infusible coals distill without changing appearance or state of agglomeration. The fusible coals soften, fuse, and usually sweU. The profile of the resultant coke is compared to a series of reference profiles so that a swelling index can be assigned. The profiles represent indexes between 0 and 9. The best cokes come from coals having indexes between 4 and 9. 

In general, enamines are sensitive to moisture, and this fact should be kept in mind if the enamine is not to be used immediately. If the enamine is to be stored for any length of time, refrigeration is recommended. Yellowing may occur on long storage, but this change appears to have little effect on the outcome of subsequent reactions. 

The histopathological features of muscle samples from patients with myotonic dystrophy are not particularly distinctive. Early changes appear to be a selective atrophy of type 1 fibers, and hypertrophy of type 2 fibers, but the biochemical and/or physiological basis of these possibly related phenomena is not known. The incidence of degenerating fibers increases with age, although the presence of internally nucleated muscle fibers in early stages of the disease suggests that the muscle retains... 

Results of analyses of raw and cooked foods demonstrate that the greatest change appears to be related to iron absorption from the iron cooking pot. 

Fig. 4. Time-induced conformational change of spider silk protein (spidroin) in solution. Solutions of silk proteins at 1% w/v in distilled water were monitored using circular dichroism. The graph shows a change in secondary structure with time. The silk proteins underwent a kinetically driven transition from a partially unfolded structure to a -sheet-rich structure (from Dicko et al., 2004c). ( ) after 0 days, (O) after 1 day, and (A) after 2 days. The conformational change appeared faster at 20°C compared to 5°C, suggesting a hydrophobically driven mechanism. (Copyright 2004 American Chemical Society.)...

Chart speed or x-axis scale Data system Sets the x-axis scale for the plotted chromatogram Changes appearance of chromatogram Does not change peak recognition, retention time, area or width Does not affect the raw data... 

See May F. Katzen, "The Changing Appearance of Research Journals in Science and Technology An Analysis and Case Study," 177214, in A. J. Meadows, ed., Development of Science Publishing. And Holmes, Eighteenth-Century Chemistry, 34. 

Exactly the same problem arises with the recent studies of NiO solubility by Tremaine and Leblanc (25) and again the thermodynamic data on the aqueous anionic species at 300 C are likely to be more reliable than on the Ni + ion. There is good spectroscopic evidence for complex formation in chlorides of nickel (II), (26) cobalt (II) (27), and copper (II) (28) at 300°C and above. Most of the work was done at rather high Cl concentrations but qualitatively the effects of dielectric constant and concentration are as expected. A noteworthy feature (which estimation procedures will have to allow for) is the change from 6 to 4 coordination at the lower pressures (150-300 bar) and the higher Cl concentrations. This change appears to take place with only 2 or 3 Cl ions coordinated to the metal (at least in the case of Ni(II)). 

Viscosity decreases as the temperature increases, and the rate of change appears to depend primarily on the nature or composition of the petroleum, but other factors, such as volatility, may also have an effect. The effect of temperature on viscosity is generally represented by the equation... 

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