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Utkin L.V.,Saint Petersburg State Forest Technical Academy | Kozine I.,Technical University of Denmark
Structural Safety | Year: 2010

New imprecise structural reliability models are described in this paper. They are developed based on the imprecise Bayesian inference and are imprecise Dirichlet, imprecise negative binomial, gamma-exponential and normal models. The models are applied to computing cautious structural reliability measures when the number of events of interest or observations is very small. The main feature of the models is that prior ignorance is not modelled by a fixed single prior distribution, but by a class of priors which is defined by upper and lower probabilities that can converge as statistical data accumulate. Numerical examples illustrate some features of the proposed approach. © 2010 Elsevier Ltd. Source

Stepakov A.V.,Saint Petersburg State University | Popova E.A.,Saint Petersburg State University | Stepakova L.V.,Saint Petersburg State University | Boitsov V.M.,Saint Petersburg State University | And 2 more authors.
Tetrahedron | Year: 2010

Imides of arylmaleic acids in the presence of 3,5-dimethyl-IH-pyrazole underwent (4+2) dimerization under heating in chlorobenzene within 24 h to afford 1,2,3,3a,3b,4,5,6,6a,10b-decahydrobenzoe1pyrrolo [3,4-g]isoindole-1,3,4, 6-tetraones in good yields. It was established that during the heating of imides of arylmaleic acid in 2,6-lutidine at 100 °C the (4+2) dimerization products containing a lutidine fragment are obtained. © 2010 Elsevier Ltd. Source

Golovin A.V.,Saint Petersburg State Polytechnic University | Ponomarev D.A.,Saint Petersburg State Forest Technical Academy | Takhistov V.V.,Russian Academy of Sciences
Journal of Theoretical and Computational Chemistry | Year: 2010

Analysis of theoretical enthalpies of formation for about 300 molecules and their fragments (free radicals, biradicals, and ions) was performed to show that the results of semiempirical, DFT, and ab initio methods must be taken with great caution. A brief review of the authors' alternative empirical methodologies for calculation of enthalpies of formation for molecules (enthalpic shift procedure) and free radicals (enthalpies of isodesmic reactions) is given. © 2010 World Scientific Publishing Company. Source

Utkin L.V.,Saint Petersburg State Forest Technical Academy | Zatenko S.I.,Saint Petersburg State Forest Technical Academy | Coolen F.P.A.,Durham University
Automation and Remote Control | Year: 2010

We propose a new class of models for software reliability based on known models employing non-homogeneous Poisson processes, e.g., Musa-Okomoto and Goel-Okomoto models. We show that the general idea of model design is in a combined application of imprecise Bayesian inference and the maximum likelihood approach. We show examples where proposed models show better reliability prediction quality compared to the known ones. © Pleiades Publishing, Ltd., 2010. Source

Metai A.,ITT Wedeco | Germer E.,Saint Petersburg State Forest Technical Academy | Hostachy J.-C.,ITT Wedeco
International Pulp Bleaching Conference 2011, IPBC 2011 | Year: 2011

The first industrial production of ozone bleached pulp started almost 20 years ago in connection with increasing environmental pressure and the Total Chlorine Free (TCF) wave. Like many other new technologies, ozone bleaching did not immediately reach its optimal efficiency from a technical viewpoint, but had to face several issues during its early years. By improving mixing technology, better understanding ozone chemistry on pulp components and tuning the whole process, the so-called ECF-Light bleaching sequences - including an ozone stage - made it possible to deliver a pulp quality similar or better than conventional ECF bleaching would do. Today the choice of ozone may still be motivated by ecological requirements but it is mostly justified by the economical savings resulting from chemicals costs cut-off. Actually, both targets are reached simultaneously when implementing an ozone bleaching stage. Through several industrial results, this work describes process improvements in ozone bleaching since 1992 and points out why should ozone now be considered as a keystone of modem pulp bleaching processes. Source

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