New Product Evaluation Using a Bayesian Dynamic Program

A method of scheduling new product evaluation steps is proposed. The method presented offers promise in reducing the costs of this evaluation. The value of each evaluation is based on Bayesian methods.     

Determination of selenium in pyrite by the atomic absorption-hydride generation technique

Summary Pyrite is digested in a (3 + 1) nitric-hydrochloric acid mixture. Nitrate is removed by warming the solution after addition of sulphuric acid. Strong hydrochloric acid is added to hydride prior generation to eliminate interference from iron. The result is compared with that obtained by neutron activation analysis. Standard deviation was in the range of 1–2 ppm.

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Selenbestimmung in Pyrit über das Hydrid mit Hilfe der AAS

Zusammenfassung Die Pyritprobe wird mit Salpetersäure/ Salzsäure aufgeschlossen und anschließend werden die Nitrationen durch Erhitzen mit Schwefelsäure entfernt. Zur Hydriderzeugung wird starke Salzsäure zugesetzt, um Störungen durch Eisen zu verhindern. Die Ergebnisse wurden mit denen der Neutronenaktivierung verglichen, wobei sich gute Übereinstimmung ergab. Die Standardabweichung liegt im Bereich von 1–2 ppm.

     

Norm attaining operators and renormings of Banach spaces

We define two geometric concepts of a Banach space, property α and β, which generalize in a certain way the geometric situation ofl andc _o. These properties have been used by J. Lindenstrauss and J. Partington in the study of norm attaining operators. J. Partington has shown that every Banach space may (3+ε)-equivalently be renormed to have property β. We show that many Banach spaces (e.g., every WCG space) may (3+ε)-equivalently be renormed to have property α. However, an example due to S. Shelah shows that not every Banach space is isomorphic to a Banach space with property α.     

Automated polarographic analysis : Part I. Design of flow-through cells and deaeration unit

The design of polarographic flow-through cells for automated analysis of discrete samples is discussed. A simple way of fitting the DME capillary into the cell is described, and the problems associated with the use of a mercury pool counter electrode are discussed. A platinum wire or gauze counter electrode downstream from the DME is more satisfactory. The reference electrode may be placed outside the flow cell, e.g. in the mercury waste bottle. A new method for the deaeration of sample solutions is also described; argon is bubbled through the solutions in the sample cups just before aspiration. The effect of various experimental parameters on the deaeration is described. Pump stoppage during sample shifts is advantageous. The adaptation of the deaeration method to commercial samplers is explained. The application of the proposed automated system for the determination of chlordiazepoxide is discussed.     

Synthesis of 7-oxopyrrolo[3,2-B]pyridine-6-carboxylic acid derivatives as potential antimicrobial agents

A route for the synthesis of various derivatives of 7-oxopyrrolo[3,2-b]pyridine-6-carboxylic acid from 2-methyl-3-carbomethoxy-4-aminopyrrole is reported.