Minimality of planes in normed spaces

We prove that a region in a two-dimensional affine subspace of a normed space $V$ has the least 2-dimensional Hausdorff measure among all compact surfaces with the same boundary. Furthermore, the 2-dimensional Hausdorff area density admits a convex extension to $\Lambda^2 V$. The proof is based on a (probably) new inequality for the Euclidean area of a convex centrally-symmetric polygon.Comment: 10 pages, v2: minor changes according to referees' comments, to appear in GAF

Best-First Surface Realization

Current work in surface realization concentrates on the use of general, abstract algorithms that interpret large, reversible grammars. Only little attention has been paid so far to the many small and simple applications that require coverage of a small sublanguage at different degrees of sophistication. The system TG/2 described in this paper can be smoothly integrated with deep generation processes, it integrates canned text, templates, and context-free rules into a single formalism, it allows for both textual and tabular output, and it can be parameterized according to linguistic preferences. These features are based on suitably restricted production system techniques and on a generic backtracking regime.Comment: 10 pages, LaTeX source, one EPS figur

The trapped heavy noble gases in recently found Martian meteorites

The composition of the trapped Ar, Kr, and Xe in the Martian meteorites Los Angeles, Say Al Uhaymir 005/008, and 094 is discussed and found to be consistent with a mixture of Martian mantle and atmosphere noble gases and terrestrial contamination

Phase Q - A carrier for subsolar noble gases

We discuss noble gases in the E-chondrite St. Mark's indicating that the subsolar component does not exclusively reside in enstatite. Element and isotope abundances including He are presented. Fractionation probably took place prior to incorporation

Solar noble gases in the Angrite parent body – Evidence from volcanic volatiles trapped in D'Orbigny glass

We compare the noble gases in D'Orbigny glass and bulk. The glass was formed after the bulk silicates and contains interior solar noble gases that may originate from early volcanic activity on the angrite parent body, trapped upon fast cooling

Ancient volcanic xenon in single glass grains from the D'Orbigny angrite

We present high-sensitivity xenon data for single glass grains from the D'Orbigny angrite. These grains contain the first sample of volcanic gas from a planetary body other than the Earth and excess Xe-129 detected for the first time in angrites

The pre-atmospheric size of Martian meteorites

The pre-atmospheric size of martian meteorites was calculated based on 80Kr produced by epithermal secondary cosmic-ray produced neutrons of 30-300 eV energy. For seven meteorites we obtained minimum radii of 22-27 cm, corresponding to 150-270 kg

Plutonium-Xenon systematics of Angrites

Introduction: Angrites are igneous meteorites that crystallized very early in the solar system, ~10 Ma after CAIs, as also implied by the presence of now extinct short-lived radionuclides such as 53Mn, 146Sm and 244Pu [1]. Fission Xe was used to calculate 244Pu-136Xeretention ages of eucrites, relative to that of Angra dos Reis (AdoR) [2]. AdoR has an absolute Pb-Pb age of 4557.8 Ma [see 1 for ref.]. Most eucrites, being as old as angrites, experienced various parent body processes leading to ages ranging from ~20 Ma before, to ~100 Ma after AdoR [2]. Angrites, however, remained largely unaltered after differentiation. Here, we examine whether Xe isotopic characteristics allow determining an age sequence for angrites

Isotopic and Micro-Raman investigation of Interplanetary Dust Particles Collected during 2003 Earth passage through Comet Grigg-Skjellerup Dust Stream

We report microscale H and N isotopic and Raman spectral data for IDPs collected in April 2003. The samples show extreme D and 15N enrichments carried by very primitive organic matter. A high abundance of D anomalies might indicate a cometary origin