Joule—Thomson Effect on Gaseous Helium

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71138/2/JCPSA6-42-8-2977-1.pd

A Unifying Theory for SIDS

The Sudden Infant Death Syndrome (SIDS) has four distinctive characteristics that must be explained by any theory proposed for it. (1) A characteristic male fraction of approximately 0.61 for all postneonatal SIDS in the US; (2) a distinctive lognormal-type age distribution arising from zero at birth, mode at about 2 months, median at about 3 months, and an exponential decrease with age going towards zero beyond one year; (3) a marked decrease in SIDS rate from the discovery that changing the recommended infant sleep position from prone to supine reduced the rate of SIDS, but it did not change the form of the age or gender distributions cited above; (4) a seasonal variation, maximal in winter and minimal in summer, that implies subsets of SIDS displaying evidence of seasonal low-grade respiratory infection and nonseasonal neurological prematurity. A quadruple-risk model is presented that fits these conditions but requires confirmatory testing by finding a dominant X-linked allele protective against cerebral anoxia that is missing in SIDS

Enthalpy determinations on the helium-nitrogen system

Experimental isobaric heat capacity and differential latent heat measurements have been made on the helium-nitrogen system. Compositions studied were nominal 5, 25, 50, and 100% helium in nitrogen over the range 0 to 2,000 lb./sq.in.abs. and −250° to 50°F. These data, combined with the previously reported work on nitrogen and the Joule-Thomson coefficients of Roebuck, are used to construct the complete pressure-enthalpy-composition network over the investigated limits of pressure and temperature. The enthalpies obtained from experimental heat capacity and Joule-Thomson data are compared with enthalpies computed from PVT data. The changes of phase determined by differential latent heat measurements are compared with literature vapor-liquid equilibrium data. This information is used to prepare pressure-enthalpy diagrams for all the mixtures investigated. A three-dimensional representation of the data on a pressure-enthalpy-composition diagram is presented. Constructions are outlined from which heats of mixing and partial molal enthalpies can be obtained. The thermodynamic network developed is believed accurate within 1% and should be of use to those concerned with low-temperature separation of helium from nitrogen.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/37341/1/690120126_ftp.pd

M: A unifying theory for SIDS

The Sudden Infant Death Syndrome (SIDS) has four distinctive characteristics that must be explained by any theory proposed for it. (1) A characteristic male fraction of approximately 0.61 for all postneonatal SIDS in the US; (2) a distinctive lognormal-type age distribution arising from zero at birth, mode at about 2 months, median at about 3 months, and an exponential decrease with age going towards zero beyond one year; (3) a marked decrease in SIDS rate from the discovery that changing the recommended infant sleep position from prone to supine reduced the rate of SIDS, but it did not change the form of the age or gender distributions cited above; (4) a seasonal variation, maximal in winter and minimal in summer, that implies subsets of SIDS displaying evidence of seasonal low-grade respiratory infection and nonseasonal neurological prematurity. A quadruple-risk model is presented that fits these conditions but requires confirmatory testing by finding a dominant X-linked allele protective against cerebral anoxia that is missing in SIDS