Platinentechnologie auf dem Vormarsch

ProdukteHeraeus Sensor-Nite

Platinentechnologie auf dem Vormarsch     

Weidmüller Ein-Bolzen-Klemme

ProdukteW-Reihe Gem?ss en 50 124-1

Weidmüller Ein-Bolzen-Klemme     

Multigrid Convergence of Calculated Features in Image Analysis

This paper informs about number-theoretical and geometrical estimates of worst-case bounds for quantization errors in calculating features such as moments, moment based features, or perimeters in image analysis, and about probability-theoretical estimates of error bounds (e.g. standard deviations) for such digital approximations. New estimates (with proofs) and a review of previously known results are provided.     

Hautbr?unung und Lichtschutz -Grundlagen, Wirkstoffe und analytische Aspekte

Ohne Zusammenfassung

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Skin tanning and light protection - theory, agents and analytical aspects

     

Untersuchungen zur Wirksamkeit von Benzyl-n-propyl-sulfid als Korrosionsinhibitor in sauren Lösungen

Investigations into the efficiency of benzyl-n-propyl sulfide as a corrosion inhibitor in acid solutions Investigations made so far into thioethers have shown that benzyl and phenyl sulfides, though being comparable from a structural point of views, may have very different inhibiting effects in the system iron-mineral acid. An attempt has therefore been undertaken to obtain further information about sorption and inhibition processes by using benzyl-n-propyl sulfide labelled with 35S. The protective effect of benzyl-n-propyl sulfide has been determined in sulfuric and hydrochloric acids under varying conditions of concentration, time, temperature and anions present, and the amount of inhibitor adsorbed to the metal surface was simultaneously measured. Other measurements were concerned with the adsorption of labelled anions from pickling acids with and without inhibitor.     

Single-bonded cubic form of nitrogen

Nitrogen usually consists of molecules where two atoms are strongly triple-bonded. Here, we report on an allotropic form of nitrogen where all atoms are connected with single covalent bonds, similar to carbon atoms in diamond. The compound was synthesized directly from molecular nitrogen at temperatures above 2,000 K and pressures above 110 GPa using a laser-heated diamond cell. From X-ray and Raman scattering we have identified this as the long-sought-after polymeric nitrogen with the theoretically predicted cubic gauche structure (cg-N). This cubic phase has not been observed previously in any element. The phase is a stiff substance with bulk modulus >or=300 GPa, characteristic of strong covalent solids. The polymeric nitrogen is metastable, and contrasts with previously reported amorphous non-molecular nitrogen, which is most likely a mixture of small clusters of non-molecular phases. The cg-N represents a new class of single-bonded nitrogen materials with unique properties such as energy capacity: more than five times that of the most powerfully energetic materials.     

A comparative evaluation of length estimators of digital curves

This paper compares previously published length estimators in image analysis having digitized curves as input. The evaluation uses multigrid convergence (theoretical results and measured speed of convergence) and further measures as criteria. This paper also suggests a new gradient-based method for length estimation, and combines a previously proposed length estimator for straight segments with a polygonalization method.     

Development of a class-specific ELISA for sulfonylurea herbicides (sulfuron screen)

The development of a direct competitive ELISA for the detection of a broad range of sulfonylurea herbicides (SUs) is described. Polyclonal antibodies were generated in rabbits using three different immunizing haptens. Antiserum with the broadest specificity was obtained with a mesosulfuronbenzylamine derivative which was coupled via a succinic acid spacer to keyhole limpet hemocyanine. A heterologous enzyme tracer which did not contain the succinic acid bridge was prepared using activated horseradish peroxidase. The direct competitive ELISA was optimized and applied for spiked tap and surface water samples. From 30 SUs, 8 compounds showed a molar cross-reactivity (CR) higher than 100% (this value was set for the hapten) and 11 compounds CRs between 10% and 100%. The ELISA can detect 16 SUs at a concentration of 0.1 microg/L or lower. Different surface and tap water samples were spiked with chlorimuron ethyl, metsulfuron methyl, or primisulfuron methyl at concentrations of 100, 200, or 500 ng/L and subsequently analyzed by both ELISA and HPLC-UV. Correlation analysis revealed good agreement between both methods (r2 = 0.983/0.948/0.982; n = 21 for each analyte). Using ELISA, no sample pretreatment other than filtration was necessary.