Stability of oval cylindrical shells

Elastic buckling under aial compression of finite, oval cylindrical shells with clamped boundaries was investigated experimentally. The determination of the buckling strength was made on a series of oval shells made of Mylar A. The test results indicated that the discrepancy between theoretical and experimental initial buckling loads for the ovals is similar to that of the circular cylindrical shells. However, in contrast to the circular case, a collapse load significantly exceeding the initial buckling load is observed in the case of ovals with moderate-to-large eccentricity.     

Quasicompact and Riesz endomorphisms of Banach algebras

Let B be a unital commutative semi-simple Banach algebra. We study endomorphisms of B which are also quasicompact operators or Riesz operators. Clearly compact and power compact endomorphisms are Riesz and hence quasicompact. Several general theorems about quasicompact endomorphisms are proved, and these results are then applied to the question of when quasicompact or Riesz endomorphisms of certain algebras are necessarily power compact.     

Spectral synthesis for Banach algebras, II

This paper continues the study of spectral synthesis and the topologies and on the ideal space of a Banach algebra, concentrating particularly on the class of Haagerup tensor products of C-algebras. For this class, it is shown that spectral synthesis is equivalent to the Hausdorffness of . Under a weak extra condition, spectral synthesis is shown to be equivalent to the Hausdorffness of . Received: 6 October 1999; in final form: 15 May 2000 / Published online: 25 June 2001     

Kinetics and Mechanism of Oxidation of 1-Phenylsemicarbazide by Peroxydisulphate

Kinetics of oxidation of 1-phenylsemicarbazide (PSC) by peroxydisulphate ion (PDS) have been carried out where by the pseudo first order condition was verified at large excess of PDS concentration. The rate of the reaction was followed spectrophotometrically, The stoichiometry was found to be 1:1 where 1-phenylazoformamide is the oxidation product. The effect of acidity on the rate of oxidation was investigated for different temperatures. The parameters of activation ΔG*, ΔH* and ΔS* were computed for both hydrogen ion depedent and hydrogen ion independent reaction pathes. A free radical mechanism was proposed.     

Reactions of stereochemically rigid diisocyanides with manganese carbonyl derivatives

The reactions of BrMn(CO)₅ with the non-chelating stereochemically rigid bidentate ligands (L-L) 1,3-, and 1,4-diisocyanobenzene, 4,4′-diisocyanobiphenyl, and 4,4′-diisocyanodiphenylmethane afford well characterized complexes of the types BrMn(CO)₄(L-L), BrMn(CO)₃(L-L)₂, and [BrMn(CO)₄]₂(L-L). Similar reactions with [RC₅H₄Mn(CO)₂NO]⁺PF₆⁻ gave mixtures of oligomers of the type [(RC₅H₄MnNO)_n(L-L)_n+1]ⁿ⁺[PF₆⁻]_n.     

Estimation of Mean and Covariance Operator for Banach Space Valued Autoregressive Processes with Dependent Innovations

In this paper we study autoregressive processes of order 1 with values in a separable Banach space it B. Such ARB(1)-processes are defined by the recursion equation