Validation interlaboratory trial for ISO 12010: Water quality—Determination of short-chain polychlorinated alkanes (SCCP) in water

A validation interlaboratory trial was carried out to prepare ISO 12010: Water quality??Determination of short-chain polychlorinated alkanes (SCCP) in water??Method using gas chromatography/mass spectrometry (GC-MS) and electron capture negative ionisation (ECNI). The task was to determine the sum of short-chain polychlorinated n-alkanes with carbon chain lengths of C₁₀?CC₁₃ and a chlorine content between 49% (g/100?g) and 67% (g/100?g) in water by GC-ECNI-MS. The quantification had to be performed by multiple linear regression as described in ISO/DIS 12010, the compulsory method. Samples distributed were real river samples, and waste water spiked with a target concentration of 0.4 and 0.6???g/L for the sum of SCCPs, i.e. a concentration around the environmental quality target level according to the European Water Framework Directive. The different types of water samples tested were surface water with <150?mg/L suspended matter, surface water with 0.5?g/L suspended matter, and filtered waste waster. The interlaboratory trial included the extraction of the water samples, a column chromatographic clean up, a concentration step, and integration of chromatographic unresolved complex mixtures as well as the calibration and quantification by multiple linear regression. The reproducibility standard deviation of the standard concentration was 11.9%. Reproducibility standard deviations of concentrations in the three different water samples between 27.8 and 34.2% were achieved by 10?C12 participating laboratories from six countries.     

Heat flow on Finsler manifolds

This paper studies the heat flow on Finsler manifolds. A Finsler manifold is a smooth manifold M equipped with a Minkowski norm F(x, ·) : T_xM → ?₊ on each tangent space. Mostly, we will require that this norm be strongly convex and smooth and that it depend smoothly on the base point x. The particular case of a Hilbert norm on each tangent space leads to the important subclasses of Riemannian manifolds where the heat flow is widely studied and well understood. We present two approaches to the heat flow on a Finsler manifold:

• as gradient flow on L²(M, m) for the energy
• as gradient flow on the reverse L²‐Wasserstein space ??₂(M) of probability measures on M for the relative entropy

Both approaches depend on the choice of a measure m on M and then lead to the same nonlinear evolution semigroup. We prove ??^{1, α} regularity for solutions to the (nonlinear) heat equation on the Finsler space (M, F, m). Typically solutions to the heat equation will not be ??². Moreover, we derive pointwise comparison results à la Cheeger‐Yau and integrated upper Gaussian estimates à la Davies. © 2008 Wiley Periodicals, Inc.     

Modeling uncertainty in multi-criteria decision analysis

his paper provides a review of multiple criteria decision analysis (MCDA) for cases where attribute evaluations are uncertain. The main aim is to identify different tools which can be used to represent uncertain evaluations, and to broadly survey the available decision models that can be used to support uncertain decision making. The review includes models using probabilities or probability-like quantities; explicit risk measures such as quantiles and variances; fuzzy numbers, and scenarios. The practical assessment of uncertain outcomes and preferences associated with these outcomes is also discussed.     

Bemerkung über Singularitäten gewisser mit Lücken behafteter Potenzreihen

Ohne ZusammenfassungIch bin Herrn Prof. Ostrowski für die Anregung zu diesen Betrachtungen, sowie für wertvolle Hinweise bei der Ausführung und Durchsicht zu großem Dank verpflichtet.     

Ueber Systeme höherer complexer Zahlen

Ohne Zusammenfassung