Preliminary Interlaboratory Trial for ISO/DIS 12010: Determination of Short Chain Polychlorinated Alkanes (SCCP) in Water

A first preliminary interlaboratory trial was planned to prepare ISO/DIS 12010: Water quality – determination of short chain polychlorinated alkanes (SCCP) in water – method using 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–C₁₃ and a chlorine content between 49 and 67% in water by GC‐ECNI‐MS and quantification by multiple linear regression described in ISO/DIS 12010 as the compulsory method. Distributed samples were obtained from a real water extract spiked with a target concentration of 0.4 µg/mL sum of SCCP, i.e. the environmental quality target level according to the Water Framework Directive. The interlaboratory trial included the calibration, a column chromatographic clean up, a concentration step and an integration of chromatographic unresolved humps as well as the quantification with multiple linear regression. Reproducibility standard deviations between 21.5 and 22.9% were achieved by 17 participating laboratories from four countries. The method outlined no significant difference of the results between the standard solution and a real water matrix extract. On the basis of this succeeded preliminary interlaboratory trial the final interlaboratory trial for validation of ISO 12010 was prepared in autumn 2010.     

The Fine Structure of the Spiral-arms

An explanation for filaments inclined to the galactic plane observed in the next-inner spiral-arm is sought in terms of self-consistent z-oscillations. These filaments or „shingles”︁ are observed to be ˜ 1.4 kpc long, 70 pc thick and inclined to the plane by ˜ 12°. In a collisionless axi-symmetric stellar system we simplify the BOLTZMANN and POISSON equations by assuming a constant density normal to the galactic plane up to z ≈︂ 200 pc and by assuming a constant radial component of the spatial coordinates. The condition for selfconsistency in the linear approximation results in shingles 1.3 kpc long, inclined to the plane by 17°. The length of the shingles is independent of the radial distance R from the centre and the inclination depends inversely on R as is observed.     

Bounds for mass and rotation of black holes in the observable universe

The bounds for the energy change rate of a Maxwell field in the outer space of a rotating black hole, calculated by de Vries (1994) and de Vries (1995), enable us to deduce limits for the rotation and the mass of black holes. For this purpose we assume that a certain part of the anisotropies of the cosmic background radiation is due to absorption or superradiance of black holes (Teukolsky, 1973, Starobinskii and Churilov, 1973). The knowledge of these anisotropies yields bounds for rotation and mass of the black holes in the observable universe.     

Großkreisdifferenzgleichen

Summary Echo soundings of the U.S. Cruiser Milwaukee in the Puerto Rico Trough in 1939 are briefly discussed, and two depths of 30246 feet or 9219 m, found at 19° 36 N, 68° 20.5 W and at 19° 35N, 68° 8.75W, are stated to be the greatest depths which are known so far in the Atlantic Ocean.     

Schallweicher und schallharter Boden im Bereich des Stoller Grundes (Kieler Bucht) in Beziehung zur Geologie

Summary Comparisons between three series of echo soundings taken by the survey- and research ships Meteor and Gauss across the shoals of the Stoller Grund and the Gabels Flach in 1934 and 1951 confirm that from the nature of the recorded echo qualitative conclusions in respect to the thickness of soft sedimentary layers can be drawn.

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Fonds amortissant et non-amortissant le son aux alentours du Stoller Grand et du Gabeis Flach (Kieler Bucht) — discutés par rapport à la géologie

Résumé Trois séries de sondages par écho qui furent effectués par dessus les bancs de sables du Stoller Grund et du Gabels Flach (Kieler Bucht) en 1934 et 1951 au bord du Meteor et du Gauss, navires hydrographiques et explorateurs, sont comparées entre elles. Ces comparaisons confirment qu'il est possible de déduire qualitativement de la nature des enregistrements l'épaisseur des couches de sédiments moux.

     

In Memoriam

Ohne Zusammenfassung     

Extrema in Sunspot Cycle Linked to Sun's Motion

Partitions of 178.8-year intervals between instances of retrograde motion in the Sun's oscillation about the center of mass of the solar system seem to provide synchronization points for the timing of minima and maxima in the 11-year sunspot cycle. In the investigated period 1632–1990, the statistical significance of the relationship goes beyond the level P=0.001. The extrapolation of the observed pattern points to sunspot maxima around 2000.6 and 2011.8. If a further connection with long-range variations in sunspot intensity proves reliable, four to five weak sunspot cycles (R0) are to be expected after cycle 23 with medium strength (R100).