Certification of the European Reference Soil Set (IRMM-443--EUROSOILS). Part II. Soil-pH in suspensions of water and CaCl2

IRMM-443 re-groups a set of six European Reference Soils (EUROSOILS), which had been certified for their adsorption coefficients for atrazine, 2,4-D and lindane (Certification of the European Reference Soil Set (IRMM-443-EUROSOILS)-Part I. Adsorption coefficients for atrazine, 2,4-D and lindane. Sci Total Environ, in press). The certification of these parameters was complemented by an additional certification of pH in suspension as well by the determination of indicative values for total nitrogen, organic and total carbon content. While Part I explained the principles of the value assignment process and discussed their application to the adsorption coefficients, Part II presents the certified values for pH as well as the indicative values for N(tot), C(tot) and C(org). In addition, the assessment of uncertainty components for stability and homogeneity, which have been included in the final uncertainty budget, is discussed.     

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Calibration of an Absolute Radiation Thermometer for Accurate Determination of Fixed-Point Temperatures

For accurate determinations of thermodynamic temperature, NPL has developed its absolute radiation thermometer (ART), which is calibrated traceably against a cryogenic radiometer. This article reviews some of the potential sources of systematic uncertainty present in the calibration and use of ART. In particular, this article is concerned with the evaluation of the size-of-source effect and the lens transmittance, as well as potential differences in the responsivity of a transfer trap detector when calibrated in terms of radiant power and used in irradiance mode.     

Microstructural evolution in ultrafine-grained titanium processed by high-pressure torsion under different pressures

A grade 2 commercially pure (CP) titanium was processed by high-pressure torsion (HPT) at pressures of 3.0 and 6.0 GPa in order to achieve improved strengths. The microhardness values for these Ti samples were plotted against the imposed strain, and the plots show that a higher saturation microhardness of 320 Hv is achieved for the sample processed at 6.0 GPa compared to a microhardness of 305 Hv when using a pressure of 3.0 GPa. The omega ω-phase has been reported in some earlier HPT investigations of pure titanium, but it was not detected in this investigation even after processing at 6.0 GPa. The absence of the ω-phase is attributed to the relatively high level of oxygen (0.25 wt%) in these CP titanium samples. The higher saturation hardness for the 6.0 GPa sample is consistent with the smaller average grain size of ~105 ± 12 nm compared with the measured grain size of ~130 ± 18 nm after processing with an imposed pressure of 3.0 GPa.     

Passwörter — fünf Mythen und fünf Versäumnisse

Bis heute wird der Zugriff auf Daten und Anwendungen überwiegend durch einen Passwortschutz kontrolliert. Oft ist dieser Passwortschutz jedoch unzureichend, weil sich für die Gestaltung von und den Umgang mit Passworten hartn?ckig unrichtige überzeugungen halten und die falschen Priorit?ten gesetzt werden.