A theoretical model of helium migration in body centred cubic (BCC)structure irons has been developed using the concept of the effective helium diffusion coefficient with the method of rate theory equations. Various helium migration mechanisms have been identified under irradiation conditions. Comparison of the effects of BCC structure and FCC structure on the effective diffusion coefficient wa...

Three experiments compared the intelligibilities of helium-speech and normal speech when both were masked by loud noise. Recordings were made of five talkers reading intelligibility word-lists. Several panels of listeners heard these recordings masked by different levels of background noise. In Experiment I, a fatigue effect seemed at first to be present differentially for the helium-speech, su...

Seven patients with status asthmaticus intubated for respiratory failure who had elevated airway pressures and persistent respiratory acidosis were successfully ventilated using a mixture of 60 percent helium and 40 percent oxygen. All patients experienced a rapid reduction in airway pressures, CO2 retention, and resolution of acidosis while breathing a helium-oxygen mixture. There were no unto...

We report fabrication and nanomechanical tension experiments on as-fabricated and helium-implanted ∼130 nm diameter Ni73P27 metallic glass nanocylinders. The nanocylinders were fabricated by a templated electroplating process and implanted with He(+) at energies of 50, 100, 150, and 200 keV to create a uniform helium concentration of ∼3 atom % throughout the nanocylinders. Transmission electron...

Solar wind measurements show that the helium abundance in the outer solar atmosphere is not constant. Recent research has isolated some of the physical mechanisms that determine helium abundance variations along an open magnetic field line: gravitational settling in both the chromosphere and corona tends to transport helium downward, while the thermal force in the transition region and the drag...

Positively charged ions were produced in supercritical helium at temperatures from 6 to 10 K and up to 2 MPa using a corona discharge. Their mobility was measured via current-voltage curves, and the hydrodynamic radius was derived using Stokes law. An initial increase and subsequent decrease of hydrodynamic radius was observed and interpreted in terms of growth, compression and solidification o...

Helium is considered an almost ideal tagging atom for cold messenger spectroscopy experiments. Although helium is bound very weakly to the ionic molecule of interest, helium tags can lead to shifts and broadenings that we recorded near 963.5 nm in the electronic excitation spectrum of C60+ solvated with up to 100 helium atoms. Dedicated quantum calculations indicate that the inhomogeneous broad...

Neutron inelastic scattering studies of the elementary excitations in con ned super uid He are reviewed. Both recent work on helium in porous silica glass (aerogel, Vycor, etc.) and earlier work on helium lms on graphite surfaces are discussed. The global picture emerging from these studies is that the three-dimensional excitations are essentially the same as in bulk helium. The characteristic ...

The infrared spectroscopy of molecules, complexes, and molecular aggregates dissolved in superfluid helium clusters, commonly called HElium NanoDroplet Isolation (HENDI) spectroscopy, is an established, powerful experimental technique for extracting high resolution ro-vibrational spectra at ultra-low temperatures. Realistic quantum simulations of such systems, in particular in cases where the s...

Early measurements of the specific heat of liquid helium confined in all three spatial dimensions suggest a coupling of individual regions of superfluid via connecting channels. Preliminary measurements have been made to investigate this apparent coupling. Although more data need to be collected before anything conclusive can be said, the available data support the idea that behavior of helium ...