The 2000 outburst of V445 Puppis shows unique properties, such as absence of hydrogen, enrichment of helium and carbon, slow development of the light curve with a small amplitude that does not resemble any classical novae. This object has been suggested to be the first example of helium novae. We calculate theoretical light curves of helium novae and reproduce the observational light curve of V...

Recent observations and theoretical investigations of neutron stars indicate that their atmospheres consist not of hydrogen or iron but possibly heavier elements such as helium. We calculate the ionization and dissociation equilibrium of helium in the conditions found in the atmospheres of magnetized neutron stars. For the first time this investigation includes the internal degrees of freedom o...

The diurnal variations in soil-gas helium concentration have been monitored at depths of 0.5-2.0 m in three localities in Colorado, Wyoming, and C•lifornia.'Bar•metric p e•su TM, air temperature, wind speed, soil temperature and moisture, relative humidity, and precipitation were also measured. The helium variation below a 1-m sampling depth usually did not exceed the analytical sensitivity of ...

Observations of the interior structure of cells and subcellular organelles are important steps in unraveling organelle functions. Microscopy using helium ions can play a major role in both surface and subcellular imaging because it can provide subnanometer resolutions at the cell surface for slow helium ions, and fast helium ions can penetrate cells without a significant loss of resolution. Slo...

Open channel fluid flow principles are applied to understand how helium might behave in the event of a release or spill in a long tunnel enclosure. An example would be helium flowing along the Tevatron accelerator tunnel as a result of some rupture of a header system. Buoyant forces would drive the helium along the ceiling until a vent to atmosphere is reached. An analogy is water flowing up to...

OBJECTIVE To compare nebulized racemic epinephrine delivered by 70% helium and 30% oxygen or 100% oxygen followed by helium-oxygen inhalation therapy via high-flow nasal cannula (HFNC) vs oxygen inhalation via HFNC in the treatment of bronchiolitis. DESIGN Prospective, randomized, controlled, single-blind trial. SETTING This study was conducted from October 1, 2004, through May 31, 2008, in...

in this paper we have down three theoretical study by using monte carlo simulation and mm+,amber and opls force field. the calculations were carried out using hyper chem professional,release 7.01 package of program. first we have studied the interaction of h2 molecule and he atomwith single-walled carbon nanotube at different temperature. for doing this study we placed h2 andhe in the center an...

Phthalocyanine and porphyrin were among the first organic compounds investigated by means of electronic spectroscopy in superfluid helium nanodroplets. Superfluid helium nanodroplets serve as a very gentle host system for preparing cold and isolated molecules. The uniqueness of helium nanodroplets is with respect to the superfluid phase which warrants the vanishing viscosity and, thus, minimal ...

Aims. We examine a recently–proposed evolutionary scenario that could explain the existence of the low–mass, helium– enriched PG1159 stars. We focus in particular on the study of the pulsational stability properties of the evolutionary models predicted by such scenario. Methods. We assess the overstability of pulsation g−modes of stellar models as evolution proceeds along the PG1159 domain. Ste...