We report the first measurements of the index of refraction of gases for lithium waves. Using an atom interferometer, we have measured the real and imaginary parts of the index of refraction n for argon, krypton, and xenon as a function of the gas density for several velocities of the lithium beam. The linear dependence of (n-1) with the gas density is well verified. The total collision cross s...

Though unilateral blood distribution of the vertebral artery has not been studied in humans, it is significant when considering the ischemic events especially embolic occlusion in vertebrobasilar system. To clarify the blood distribution, Krypton-81m was continuously infused into the vertebral arteries of 10 patients. Radioactivity was recorded by a rotating gamma camera. The perfusion images, ...

The origin of the terrestrial atmosphere is one of the most puzzling enigmas in the planetary sciences. It is suggested here that two sources contributed to its formation, fractionated nebular gases and accreted cometary volatiles. During terrestrial growth, a transient gas envelope was fractionated from nebular composition. This transient atmosphere was mixed with cometary material. The fracti...

The influence of the nuclear medium on lepto-production of hadrons was studied in the HERMES experiment at DESY in semi-inclusive deep-inelastic scattering of 27.6 GeV positrons off deuterium, nitrogen and krypton targets. The differential multiplicity for krypton relative to that of deuterium has been measured for the first time for various identified hadrons (π+, π−, π0, K+, K−, p and p̄) as a...

• The Kety-Schmidt method for measurement of regional blood flow was first applied to the heart by Eckenhoff et al. These investigators employed coronary sinus catheterization to measure myocardial blood flow with nitrous oxide. The use of a radioactive gas and an external detector for the measurement of organ blood flow was investigated by Conn, Lewis et al., and Lassen et al. The radioactive ...

Monolayer System Physisorbed onto Graphite: Argon and Krypton Patch Impurities M. W. Roth Department of Natural Sciences, Texas A&M International University, 5201 University Boulevard, Laredo, Texas 78041 Received February 10, 1998. In Final Form: December 24, 1998 A constant density (F ) 1) constant temperature molecular dynamics method with periodic boundary conditions is utilized to examine ...

The measurement of cerebral blood flow by means of the nitrous oxide method of Kety and Schmidt (1) or the krypton-85 (Kr85) technique of Lassen and Munck (2) requires a steady state of at least ten minutes, for it is not until the end of such a period that the uptake of the gas by the brain can be estimated indirectly from its concentration in cerebral venous blood. These methods are, therefor...

The isotopic abundance of (85)Kr in the atmosphere, currently at the level of 10(-11), has increased by orders of magnitude since the dawn of nuclear age. With a half-life of 10.76 years, (85)Kr is of great interest as tracers for environmental samples such as air, groundwater and ice. Atom Trap Trace Analysis (ATTA) is an emerging method for the analysis of rare krypton isotopes at isotopic ab...

Recent ellipsometric and calorimetric studies of argon and krypton adsorbed on triangular lattice graphite substrates have found a novel sequence of apparent reentrant layering transitions between integer-plus-one-half coverages. Related behavior has been demonstrated in a Monte Carlo study by Phillips, Zhang, and Larese. In contrast to arguments made by these authors, however, we use solidon-s...