204 resultados para Duns Scotus, John, approximately 1266-1308.
Resumo:
The kinetics of the acid-catalysed hydrolysis of cellobiose in the ionic liquid 1-ethyl-3-methylimidazolium chloride, [C(2)mim]Cl, was studied as a model for general lignocellulosic biomass hydrolysis in ionic liquid systems. The results show that the rate of the two competing reactions, polysaccharide hydrolysis and sugar decomposition, vary with acid strength, and that for acids with an aqueous pK(a) below approximately zero, the hydrolysis reaction is significantly faster than the degradation of glucose, thus allowing hydrolysis to be performed with a high selectivity in glucose. In tests with soluble cellulose, hemicellulose (xylan), and lignocellulosic biomass (Miscanthus grass), comparable hydrolysis rates were observed with bond scission occurring randomly along the biopolymer chains, in contrast to end-group hydrolysis observed with aqueous acids.
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Cellulose-magnetite composites have been prepared by suspension and dispersion of magnetite particles in a homogenous ionic liquid solution of cellulose, followed by regeneration into water, enabling the preparation of magnetically responsive films, flocs, fibers, or beads. The materials prepared were ferromagnetic, with a small superparamagnetic response, characteristic of the initial magnetite added. X-ray diffraction data indicated that the magnetite particles were chemically unaltered after encapsulation with an average particle size of approximately 25 nm.
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The amphiphilic association structures were determined in the system; water, Laureth 4 (approximately C-12(EO)(4)), and the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]), using visual observation and small angle x-ray diffraction. The system showed a lamellar liquid crystal solubilizing the ionic liquid ([bmim][PF6]) to a maximum of 15%, an isotropic surfactant solution dissolving the ionic liquid to a maximum of 39%, an isotropic ionic liquid solution with less than 0.5% of water and surfactant and finally, an aqueous solution with only traces of surfactant and ionic liquid. The small angle x-ray diffraction results showed the ionic liquid to be solubilized into the lamellar liquid crystal without changing the dimensions of the amphiphile layer or the interlayer spacing dependence on the water content.
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This article examines a previously unnoticed link between the Puritan John Burgess and the Calvinist conformist George Hakewill. In 1604 Burgess preached a court sermon so outspoken and critical of James I’s religious policy that he was imprisoned. Nearly twenty years later, however, Hakewill chose to incorporate extended passages from Burgess’s sermon into the series of sermons, King David’s vow (1621), preached to Prince Charles’s household. This article considers why Burgess’s sermon became so resonant for Hakewill in the early 1620s and also demonstrates how Hakewill deliberately sought to moderate Burgess’s strident polemic. In so doing the article provides important new evidence for the politically attuned sermon culture at Prince Charles’s court in the early 1620s and also suggests how, as the parameters for clerical conformity shifted in the latter years of James’s reign, Calvinist conformists found a new appeal in the works of moderate Puritans. I
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Book Review