We study the formation of ultra-compact binaries (AM CVn stars and ultra-compact X-ray binaries) with emphasis on the surface chemical abundances of the donors in these systems. Hydrogen is not convincingly detected in the spectra of any these systems. Three different proposed formation scenarios involve different donor stars, white dwarfs, helium stars or evolved main-sequence stars. Using det...

A non-scaling fixed field alternating gradient (nsFFAG) accelerator is being designed for helium ion therapy. This facility will consist of 2 nested rings, treating with helium ions (He) and image with hydrogen ions (H + 2 ). Compared to protons, ions deliver a more conformal dose with a significant reduction in range straggling and beam broadening. Carbon ions are currently used and there are ...

The Galileo probe showed that Jupiter's atmosphere is severely depleted in neon compared to protosolar values. We show via ab initio simulations of the partitioning of neon between hydrogen-helium phases that the observed depletion can be explained by the sequestration of neon into helium-rich droplets within the postulated hydrogen-helium immiscibility layer of the planets interior. We also de...

Expired volume was measured with a Godart pneumotachograph at the expiration port of the ventilator (Fig 1, tracing 5). We measured the concentration of helium with a katharometer (Codart, response time 0.1 see), at the expiration port of a Siemens-Elema-900 ventilator. From equations 2 and 3, it follows that absolute calibration of the helium meter is not necessary; only linearity of the meter...

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...