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Condensation sequences

The structure of the solid determines the mechanism for which internal liquid flow may occur. These mechanisms can include (1) diffusion in continuous, homogeneous solids, (2) capillary flow in granular and porous sohds, (3) flow caused by shrinkage and pressure gradients, (4) flow caused by gravity, and (5) flow caused by a vaporization-condensation sequence. [Pg.1179]

Scheme 2.29. Domino Michael addition/Dieckmann condensation sequences leading to precursors of natural products. Scheme 2.29. Domino Michael addition/Dieckmann condensation sequences leading to precursors of natural products.
Delcour, J.A., Ferreira, D., and Roux, D.G., Synthesis of condensed tannins part 9. The condensation sequence of leucocyanidin with (-l-)-catechin and with the resultant procyanidins. J. Chem. Soc. Perkin Trans. /1711, 1983. [Pg.313]

Calculated condensation sequence for a gas of solar composition at 10-4 atm. Condensed minerals are labeled in italics and curves show the fraction of each element condensed as a function of temperature. Modified from Grossman and Larimer (1974). [Pg.197]

Iteration of this process at successively lower temperatures gives a condensation sequence. These calculations would be extremely tedious, except for the advent of modern computer systems. [Pg.198]

Comparison of four condensation sequences, all at 10 3 atm but using different models. These calculations are from (left to right) Petaev and Wood (1998), Ebel and Grossman (2000), Yoneda and Grossman (1995), and Wood and Hashimoto (1993). Mineral abbreviations and formulae are given in Table 7.2. Modified from Ebel (2006). [Pg.199]

Variations in gas pressure also affect the condensation sequence, as illustrated in Figure 7.3. Except for differing pressures (10-3 to 10-5 atm), the parameters for these two calculations are identical. The temperatures and orders of appearance of condensed minerals clearly vary with pressure. [Pg.199]

Table 7.2 Mineral names, abbreviations, and formulae commonly found in condensation sequences... Table 7.2 Mineral names, abbreviations, and formulae commonly found in condensation sequences...
Comparison of two condensation sequences calculated at different pressures. Abbreviations and formulae are given in Table 7.2. Modified from Ebel (2006). [Pg.200]

On the other hand, fine-grained CAIs consist of aggregates of nodules with a concentric structure consisting of spinel cores surrounded by melilite, anorthite, and diopside, or melilite cores surrounded by anorthite and diopside (Fig. 7.5). The sequence of minerals in the nodules is consistent with a condensation sequence. However, the textures of the overall objects are complicated and often indicate extended and multistage histories. For... [Pg.202]

Element and isotopic abundances of Si and Mg in CAIs suggest evaporation, (a) Correlated isotopic fractionations in Type CAIs. (b) Si02 versus MgO for CAIs, relative to the calculated condensation sequence abundances (heavy line). Unmelted Type A inclusions (open circles) follow the condensation path, whereas partly melted Type inclusions (filled circles) deviate, because of loss of both Mg and Si, as illustrated by the arrow. Modified from Davis and Richter (2004). [Pg.209]

Describe the important minerals in the condensation sequence, and their order of appearance from a cooling gas of solar composition. [Pg.226]

Lewis and Edstrom [84] have provided qualitative thermal reactivity data of various polynuclear benzenoid hydrocarbons. They classified the compounds as either thermally reactive or thermally unreactive . The thermally reactive species possess sufficient reactivity in an atmospheric pressure system to undergo a condensation sequence in the liquid phase and yield a measurable amount of polymerized carbonaceous residue at 750 °C. The thermally unreactive species have sufficient stability so that such condensation reactions do not occur prior to complete volatilization. From 30 alternant (unsubstituted) systems studied 10 were found to be reactive. [Pg.117]

In this manner, a hydroformylation/condensation sequence of 0-vinyl-anilines give indoles directly. The starting o-vinylanilines are obtained by Heck reaction of the corresponding o-haloanilines. Hydroformylation of these styrene-type olefins proceeds preferably at the benzyl carbon. Intramolecular condensation gives pharmacologically interesting tryptophols and tryptamines in mediocre to good yields (Scheme 12, Table 1) [47]. [Pg.72]

Table 4.3 Condensation sequence for the early solar nebula... Table 4.3 Condensation sequence for the early solar nebula...
The process of condensation of minerals in the early solar nebula has long been invoked to explain the chemistry and mineralogy of primitive chondritic meteorites (e.g. Cameron 1963). Their observed bulk compositions show volatile-element depletions that are clearly smooth functions of calculated condensation temperature in a gas of solar composition (Davis 2006). Despite this success in explaining the bulk composition of chondrites, the diverse mineralogy of these bodies is not reproduced well in the condensation sequence calculations. To date, there is no incontrovertible evidence for direct condensation of rocky meteoritic material in the... [Pg.232]

The assembly of the cyclohexene derivatives D should be feasible via an organocatalyzed domino Michael/Michael/aldol condensation sequence starting from a linear aldehyde A, a nitroalkene B and an a,(->-unsaturated aldehyde C. [Pg.76]

The possibility of such a condensation sequence has also been demonstrated for rhodium methylene complexes which on thermolysis give selectively methane and propene 54... [Pg.1252]

Schramm nee Dediu OG, Muller TJJ (2006) Microwave-accelerated coupling-isomerization-enamine addition-aldol condensation sequences to l-acetyl-2-amino-cyclohexa-1,3-dienes. Synlett 1841-1845... [Pg.93]


See other pages where Condensation sequences is mentioned: [Pg.244]    [Pg.96]    [Pg.232]    [Pg.81]    [Pg.33]    [Pg.400]    [Pg.192]    [Pg.196]    [Pg.198]    [Pg.3]    [Pg.217]    [Pg.22]    [Pg.111]    [Pg.112]    [Pg.162]    [Pg.115]    [Pg.143]    [Pg.143]    [Pg.80]    [Pg.201]    [Pg.712]   
See also in sourсe #XX -- [ Pg.196 ]

See also in sourсe #XX -- [ Pg.15 ]




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Ammonia condensation sequence

Chemoselective condensation sequence

Condensation/hydride reduction sequence

Isotopic anomalies and condensation sequence

Magnesium condensation sequence

Meteorites condensation sequence

Methane condensation sequence

Silicon condensation sequence

Vaporization-condensation sequence

Water condensation sequence

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