Flash vacuum pyrolysis of 3-t-butylindeno[1,2-c]isoxazol-4-one. Formation of 2-carbonyl-1,3-indandione 2-azine

Flash Vacuum Pyrolysis (FVP) of 3-t-Butylindeno[1,2-c]isoxazol-4-one ( 1 ) and 3-t-Butylspiro[2H-azirine-2,2′-(2H)indene]-1′,3′-dione ( 2 ) were carried out. Reaction of 1 from 300–400° afford 2 and 2-carbonyl-1,3-indandione 2-azine ( 3 ) as the major products, whereas 2-t-Butylindeno[1,3-c]oxazol-4-one ( 4 ) was the main products in FVP of 2 together with minor amounts of 3.     

Behaviour of a complex system having stand-by components in spares

Summary The reliability characteristics of a stand-by redundant complex system with instantaneous switch over have been discussed in two sections of this paper. In Section (I), it has been assumed that spare components can not fail in the stand-by interval where as in Section (II), it has been considered that they can fail even in the stand-by interval. TheLaplace-Stieltjes transforms of the distribution of the first time to system failure have been derived by using the signal flow graph method [Chow-Cassignol, 1962]. In the end, the mean time to system failure (MTSF) has also been evaluated.

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Zusammenfassung In diesem Artikel wird der Charakter der Zuverlässigkeit eines komplexen redundanten Systems mit Reserve, die ohne Zeitverzögerung eingeschaltet werden kann, in zwei Abschnitten diskutiert. Während im ersten Teil die Annahme gemacht wird, daß die Ersatzkomponenten nicht ausfallen können, bevor sie eingesetzt werden, wird im zweiten Teil diese Möglichkeit berücksichtigt. DieLaplace-Stieltjes Transformation der Verteilung der Zeit bis zum ersten Systemausfall wird mit der Signalfluß-Graphen-Methode erhalten. Zum Abschluß wird der Erwartungswert dieser Zeit berechnet.

     

Effect of plasma on efficiency enhancement in a high powerrelativistic backward wave oscillator

A linear theory of the excitation of electromagnetic waves in a plasma-filled backward-wave oscillator driven by an intense relativistic electron beam is presented. It is found that the spatial growth rate of backward-wave instability exhibits a resonant increase for a particular value of fill-plasma density. Results are compared to the results of an experiment by K. Minami et al. (1988) on a high-power backward-wave oscillator     

A New Synthesis of 2-Arylbenzothiazoles from 1,2,3-Benzodithiazole-2-Oxides

The reaction of 6-substituted-1,2,3-benzodithiazole-2-oxides (3a-3d) with aromatic aldehydes, carboxylic acids, and their chlorides in the presence of an organic base provides a new method for the synthesis of 6-substituted-2-arylbenzothiazoles (4a-4d) without involving the preparation of intermediate 2-aminobenzenethiols.