Sulfur maceral concentrates

H/C = atomic hydrogen-to-carbon ratio V = vitrinite content of coal VM volatile matter St = total sulfur TRM = total reactive macerals The adequacies of these reactivity correlations, expressed as a percentage of the total variation in the data set explained by the model, were 80.0%, 79.2%, and 47.5% respectively. A later paper in the series (21) concentrated on the development of reactivity correlations for a set of 26 high volatile bituminous coals with high sulfur contents, and extended the models previously developed in include analyses of the liquefaction products and coal structural features. These structural features included the usual... 

White musts and wines made without maceration contain very low amounts of flavonoids. However, when making white wine from white grapes, skin contact at low temperature is sometimes performed before pressing and fermentation to increase extraction of volatile compounds and aroma precursors. After 4h of skin contact, the concentration of flavanol monomers and dimers in must was increased threefold. Delays between harvest and pressing, especially if sulfur dioxide is added to prevent oxidation, as well as thorough pressing, similarly result in increased concentrations of flavonoids in white musts and wines. " " ... 

Transmission electron microscopy has been used to determine the concentration of organic sulfur in coal. Because the electron beam can be focused to a fine spot on the coal specimen, the variation of organic sulfur in the macerals can be measured over distances as short as 1 pm or less. Thus, spatial variation can be determined within a particular maceral and across maceral boundaries in thinned coal foils. The excellent spatial resolution has also permitted us to measure the organic sulfur concentration in close proximity to sulfides we find that the organic sulfur concentration is constant over the maceral to within 1 pm of the pyrite. 

One must conclude, therefore, that there is no gradient in organic S concentration in the vicinity of the pyrite at distances greater than 1pm. Consequently, the pyrite and adjacent maceral are in a two-phase state with no intervening phase. Since the activity of S in pyrite has a specific value (at a given temperature) independent of the coal, and since the organic sulfur concentration varies among the coals, the sulfur in the maceral and the sulfur in pyrite must not be in thermodynamic equilibrium. 

Contact time, temperature and sulfiting are factors that influence phenolic compound dissolution and color in rose wines (Castino, 1988). Sulfur dioxide is known to have a certain dissolvent power (Section 8.7.5). It is not manifested during traditional red winemaking, due to the preponderant effects of other factors (duration, temperature and pumping-over). Yet when maceration is limited, the effect of sulfiting is obvious. Table 14.3 shows the impact of the winemaking techniqne on the color intensity and phenolic componnd concentrations of rose wines. Sulfiting promotes anthocyanin dissolution and color enhancement. It is not easy to control the conditions that will produce the required color and phenolic structure, as they depend on the specific characteristics of the wine. 

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