Originating from the seedpods of orchids, Vanilla belongs to the most widely appreciated flavours worldwide. Besides the seedpods (beans) also Vanilla extracts and isolated vanillin as the major characteristic aroma compound are commercially used. Different consumer demands and national regulations require appropriate quality control of products arising from the Vanilla plants. Depending on the kind of product and its position in the supply or value chain, different methods for quality control and authentication have to be applied. When examining plant material for instance DNA barcoding can be used, whereas for Vanilla extracts and vanillin analytical quality control is frequently employed. As one of the first chemically synthesized flavouring substances with its first production in the late 19th century vanillin is nowadays manufactured via multiple different chemical and natural routes. To discriminate commercial vanillin qualities by their precursors with respect to the chemical and natural origin stable isotope ratio mass spectrometry (sIRMS) and 1H nuclear resonance spectroscopy (NMR) are the most recognized techniques. This article describes new features to discriminate vanillin from different origins using the δ13C and δ2H ratios of the methoxy group after derivatization with hydriodic acid and subsequent measurement of the released gaseous methyl iodide (CH3I) with sIRMS. The combination of available analytical data by means of multiparametric statistical tools allows for the clear segregation of critical provenience clusters for vanillin, such as (natural) eugenol‐derived qualities from (synthetic) lignin‐ or curcumin‐based products. The approach supports quality and authenticity control for Vanilla‐based products, aiding in meeting customer expectations in this demanding market segment.

In this paper we consider several aspects related to the application of the pseudo‐concentration techniques to the simulation of mould filling processes. We discuss, in particular, the smoothing of the front when finite elements with interior nodes are employed and the evacuation of air through the introduction of temporary free wall nodes. The basic numerical techniques to solve the incompressible Navier—Stokes equations are also briefly described. The main features of the numerical model are the use of div‐stable velocity—pressure interpolations with discontinuous pressures, the elimination of the pressure via an iterative penalty formulation, the use of the SUPG approach to deal with convection‐dominated problems and the temporal integration using the generalized trapezoidal rule. At the end of the paper we present some numerical results obtained for a two‐dimensional test problem showing the ability of the method to capture complicated flow patterns.

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A suitable representation of the regional gravity field is used to estimate relative offsets between national height system realizations in Europe. The method used is based on a gravimetric approach and benefits from the significant improvements in the determination of the global gravity field by the recent satellite gravity missions the Gravity Recovery and Climate Experiment (GRACE) and the Gravity field and steady-state Ocean Circulation Explorerr (GOCE). The potential of these missions for the unification of height reference frames is analyzed in terms of accuracy and spatial resolution. The results of the gravimetric approach are compared to the independent results of the geodetic leveling approach. Advantages and drawbacks of both methods are discussed.

Abstract.For an affine semigroup ring we construct the dualizing complex in terms of the semigroup and the homology of the face lattice of the polyhedral cone spanned by the semigroup. As a consequence there are characterizations of locally Cohen-Macaulay rings, Buchsbaum rings, and Cohen-Macaulay rings as well as Serre's condition AAr°¡.

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