Related papers: Alkali recondensation into chondrules
Millisecond crystal relaxation has been used to explain anomalous decay in doped alkali halides. We attribute this slowness to Fermi-Pasta-Ulam solitons. Our model exhibits confinement of mechanical energy released by excitation. Extending…
Chondrules represent one of the best probes of the physical conditions and processes acting in the early solar nebula. Proposed chondrule formation models are assessed based on their ability to match the meteoritic evidence, especially…
In regions where stars form, variations in density and temperature can cause gas to freeze-out onto dust grains forming ice mantles, which influences the chemical composition of a cloud. The aim of this paper is to understand in detail the…
Wet granular materials are characterized by a defined bond energy in their particle interaction such that breaking a bond implies an irreversible loss of a fixed amount of energy. Associated with the bond energy is a nonequilibrium…
We present new results on CO depletion in a sample of nearby pre-stellar cores, based on observations of the millimeter C17O and C18O lines and the 1.3 mm dust emission with the IRAM 30m telescope. In most cases, the distribution of CO is…
The bulk volatile contents of chondritic meteorites provide clues to their origins. Matrix and chondrules carry differing abundances of moderately volatile elements, with chondrules carrying a refractory signature. At the high temperatures…
Two different types of experiments were performed. In the first experiment, we studied the low-temperature condensation of vaporized graphite inside bulk liquid helium, while in the second experiment, we studied the condensation of single…
Al(110) has been studied for temperatures up to 900 K via ensemble density-functional molecular dynamics. The strong anharmonicity displayed by this surface results in a negative coefficient of thermal expansion, where the first interlayer…
Molecular segregation in methanol-water mixtures is studied across a wide concentration range as a function of temperature and pressure. Cluster distributions obtained from both neutron diffraction and molecular dynamics simulations point…
Chondrules are thought to have formed during transient flash-heating events in dust-enriched regions of the solar protoplanetary disk. Although laboratory studies have characterized the oxygen isotopic compositions of chondritic materials,…
We have produced a Bose-Einstein condensate of metastable helium (4He*) containing over 1.5x10^7 atoms, which is a factor of 25 higher than previously achieved. The improved starting conditions for evaporative cooling are obtained by…
Reconstruction of the thermal history of individual meteorites which can be assigned to the same parent body allows to derive general characteristics of the parent body, which hold important clues on the planetary formation process. This…
We present a study of the elemental depletion in the interstellar medium. We combined the results of a Galatic model describing the gas physical conditions during the formation of dense cores with a full-gas-grain chemical model. During the…
We experimentally demonstrate the formation of salt aggregations with unexpectedly high concentration inside multi-walled carbon nanotubes (CNTs) soaked only in dilute salt solutions and even in solutions containing only traces of salts.…
The vertical structure of stationary thin accretion discs is calculated from the energy balance equation with heat generation due to microscopic ion viscosity {\eta} and electron heat conductivity {\kappa}, both depending on temperature. In…
The stability of two-component clusters consisting of light (Na or K) and heavy (Rb or Cs) alkali atoms formed on helium nanodroplets is studied by femtosecond laser ionization in combination with mass spectrometry. Characteristic stability…
Shock wave heating is a leading candidate for the mechanisms of chondrule formation. This mechanism forms chondrules when the shock velocity is in a certain range. If the shock velocity is lower than this range, dust particles smaller than…
The occurrence of concentration and temperature gradients in saline microdroplets evaporating directly in air makes them unsuitable for nucleation studies where homogeneous composition is required. This can be addressed by immersing the…
The reaction of alkali (Na, Cs) clusters with water clusters embedded in helium nanodroplets is studied using femtosecond photo-ionization as well as electron impact ionization. Unlike Na clusters, Cs clusters are found to completely react…
NaCl solvation turns the fS portion molecules into the hydrating supersolid phase by ionic polarization and leaves the rest fO portion ordinary. Polarization shortens and stiffens the HO bond and does the O:H nonbond contrastingly in the…