the treatment equimolar quantities of carboxylic acids with acid chlorides in the presence of zno brings abouthighly efficient unsymmetrical anhydrides at room temperature in solvent-free condition. reactivity trendsfavored formation of the product using both electron deficient and rich aryl acids and acid chlorides.

compared to conventional chlorination methods which apply chlorine at water treatment plant, booster chlorination has almost solved the problems of high dosages of chlorine residuals near water sources and lack of chlorine residuals in the remote points of a water distribution system (wds). however, control of trihalomethane (thm) formation as a potentially carcinogenic disinfection by-product ...

We examine the extent to which product differentiation affects duration of US import trade relationships. The results are consistent with a matching model of trade formation. Using highly disaggregated product level data we estimate the hazard rate is at least 23 percent higher for homogeneous goods than for differentiated products. The results are not only highly robust but are often strengthe...

Experimental evidence for a 5-exocyclic methylene-dUMP intermediate in the thymidylate synthase reaction was recently obtained by demonstrating that tryptophan 82 mutants of the Lactobacillus casei enzyme produced 5-(2-hydroxyethyl)thiomethyl-dUMP (HETM-dUMP) (Barret, J. E., Maltby, D. A., Santi, D. V., and Schultz, P. G. (1998) J. Am. Chem. Soc. 120, 449-450). The unusual product was proposed ...

Catalytic naphtha reforming is one of the most important processes in which, low quality naphtha is converted into high octane motor gasoline. In this study, a mathematical model was developed and was used for investigation the effect of temperature, pressure, hydrogen to hydrocarbon ratio on the octane number, the yield of product and the undesirable phenomena of coke deposition in a semiregen...