On the Flammable Limits of Gas Mixtures

INTRODUCTIONCarbon monoxide occupies a special place among combustible gases. The high flammable limit, the slowness of its flame propagation, and the role of water vapor in its combustion all suggest a resistance to oxidation that its heat of combustion would not have allowed us to anticipate. It behaves among gases a little like aluminum among metals. We thought that it would be interesting to define its flammable conditions slightly more precisely than previously done.Carbon monoxide was prepared by decomposing sodium formiate with sulfuric acid; recovered in a small water gas holder, the gas contained 7% air at time of use.Normal Flammable LimitsThese limits were determined in defined conditions by one of us as the most favorable for this type of test, that is, in a test tube 40 mm in diameter and 20 cm in length, with ignition by a 1-cm flame through the opening held in

如何选择适合的植酸酶

过去的20年，磷的消化性研究已经占领了动物营养科学界研究的较大一部分，特别是在成功引进第一个商用磷酶（植酸酶）后。如今，大家普遍认为，在家禽或猪日粮中加入适当的植酸酶，能够降解口粮中大量的植酸（植物源性）磷。植酸酶是一种不可消化的磷，在不使用外源性植酸酶（动物不分泌这种酶）的情况下它会被排入环境中。因此，磷酸酶不仅能提高磷的消化率（10％以上），而且它们也能够保护环境，减少磷的排放约30％。此外，已知植酸酶能像对磷一样改善钙的消化率，另外，研究表明，它们还可以提高更多营养物质的消化率，这些养分同样被植酸结合，如蛋白质和微量元素。