Hyperpolarized (hp) (129)Xe and hp (83)Kr for magnetic resonance imaging (MRI) are typically obtained through spin-exchange optical pumping (SEOP) in gas mixtures with dilute concentrations of the respective noble gas. The usage of dilute noble gases mixtures requires cryogenic gas separation after SEOP, a step that makes clinical and preclinical applications of hp (129)Xe MRI cumbersome. For h...

Introduction: Trapped noble gases were discovered in chon-drules by laser microprobe noble gas analysis [1-3]. The observed noble gases were explained by solar gas acquisition in dust grains before the chondrule formation [1-3]. These results show importance of trapped noble gases in chondrites to understand environment and formation processes of chondrules. We performed the laser microprobe no...

Introduction: Pallasites are stony-iron meteorites that likely formed at the core-mantle boundary of one or more differentiating parent bodies [e.g., 1]. The noble gas concentrations of palla-sites are interesting for several reasons. First, some samples of Brenham olivines contain solar gases [2,3], which raises the question how the olivines managed to retain the trapped solar component during...

Marrocchi et al. (2005) reported that low-temperature fractions of heavy noble gases were largely removed upon pyridine treatment of the Orgueil CI meteorite. As pyridine is known to induce the swelling of the macromolecular network of organic matter, they concluded that the low-temperature phase Q is macromolecular organic carbon. However, Busemann et al. (2008) showed that pyridine had no sig...

Polar ice cores constitute excellent archives of past environmental conditions and provide us with glimpses into the Earth’s climatic history over hundreds of thousands of years. For the past two decades, noble gases, used as conservative tracers, have played a substantial role in extracting information from these archives. Noble gas analysis can be performed on two types of ice core samples. F...

Recently, it was shown that genuine Ng-Ng chemical bonds are present in the endohedral fullerenes Ng(2)@C(60) in the case of Ng=Xe, while it is more debatable whether a chemical bond exist for Ng=Ar and Kr. The lighter homologues with helium and neon are weakly bonded van der Waals complexes. The presence of a noble gas dimer inside the cage is expected to modify the exohedral reactivity of the...

......................................................................................................................................... 1 Chapter 1: Introduction ............................................................................................................... 2 1.1. Background ..........................................................................................................

There are two types of planetary noble gases. One containing isotopically " anomalous: argon ,krypton and xenon but isotopically " normal " helium and neon, was derived from outer stellar regions. The other, consisting almost entirely of isotopically " normal " argon, krypton and xenon with little or no helium or neon, was derived from inner stellar regions. Mixing of nucleosynthesis products f...

The ideal geochronometer would be a universally stable phase that quantitatively retains both parent and daughter isotopes. Though a few mineral systems such as zircon U-Pb dating come reasonably close to this ideal, most minerals are incompletely retentive of daughterproduct nuclides under crustal conditions. The mechanisms by which the daughter product can be lost from minerals include dissol...