Sulfur availability

Wheat proteins can be classified based on their sulfur content (Wrigley et al. 1984). Sulfur-rich proteins comprise LMW-GS alpha- beta-, and 

Lance line Temperature regime 2001 Time % UPP starts steep increase (DAA) % UPP at maturity SDS-sed. volume (mL) 2002 Time % UPP starts steep increase (DDA) % UPP at maturity  

Source Reproduced with permission from Irmak, S. et al. 2008. Journal of Cereal Science 48 513-516. 

Notes DAA days after anthesis Temperature regimes  

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The Doctor test measures the amount of sulfur available to react with metallic surfaces at the temperature of the test. The rates of reaction depend on metal type, temperature, and time. In the test, a sample is treated with copper powder at 149°C or 300°F. The copper powder is filtered from the mixture. Active sulfur is calculated from the difference between the sulfur contents of the sample (ASTM D129) before and after treatment with copper. 

However, the situation is not as clear-cut for the liquid-phase oxidation, which, we have seen, predominates in many (perhaps most) situations. In this case, a less than 1 1 relationship between the reduction in H2S04 formed and S02 emitted may result for a number of reasons operating on the microscopic scale. For example, less H202 is available in many clouds than is needed to oxidize all of the S(IV) that is present, and hence the oxidation can be limited by the availability of oxidant (e.g., see Dutkiewicz et al., 1995). Another important factor that comes into play is the interplay between the acidity of the aqueous phase, the reaction kinetics, and the solubility of S(IV). Thus, as seen in Chapter 8, the solubility of S(IV) decreases as the aqueous phase becomes more acidic, limiting the total sulfur available for oxidation. In addition, all oxidations in the aqueous phase except that by H202 are pH dependent as a result, the contribution of... 

The importance of sulfur as an industrial chemical is discussed and forecasts of projected sulfur demand in the U.S. are given. Three processes for conversion of coal and oil shale to synthetic fuels are examined in some detail to show how the sulfur in the original feedstock material is recovered as elemental by-product sulfur. Three synthetic fuel scenarios are examined and their potential impact on sulfur availability with current and projected markets to the year 2000 are examined. 

We will examine three synthetic fuel scenarios and compare their implications regarding sulfur availability with the current and projected market for sulfur to the year 2000. The analysis will consider three production levels of synthetic fuels from coal and oil shale. A low sulfur Western coal will be utilized as a feedstock for indirect liquefaction producing both synthetic natural gas and refined liquid fuels. A high sulfur Eastern coal will be converted to naphtha and syncrude via the H-Coal direct liquefaction process. Standard retorting of a Colorado shale, followed by refining of the crude shale oil, will round out the analysis. Insights will be developed from the displacement of imported oil by synthetic liquid fuels from coal and shale. 

These GVB results suggest that we may think of SF forming in a hypothetical sequence in which the axial fluorines first form largely ionic bonds to sulfur, thus promoting an effective sp3 valence configuration of sulfur. The four sulfur electrons are left in a tetrahedral orientation on sulfur available for the bonds with the equatorial fluorines. 

Chen, C.R., Condron, E.M., Davis, M.R. and Sherlock, R.R. (2001) Effects of land-use change from grassland to forest on sulfur availability and arylsulfatase activity in New Zealand. Australian Journal of Soil Research 39, 749-757. 

MacRitchie, R, and R. B. Gupta. 1993. Functionality-composition relationships of wheat flour as a result of variation in sulfur availability. Australian Journal of Agricultural Research 44 1767-1774. 

Logistics was also a governor on sulfur availability from the blocks. During these periods of strong demand, there was not nearly enough eapacity either to melt the bloeks or to ship the extra volumes out of Vancouver. In other words, it was mueh easier to put the sulfur into blocks than to take it out. 

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