Nikitin I.S. Models of multiaxial fatigue and life time estimation of structures \\ Mechanics of Solids

Abstract-We study criteria and models of multiaxial fracture under the conditions of low-cycle fatigue (L.CF). The model parameters are determined by using the data of uniaxial fatigue tests for different coefficients of the cycle asymmetry. A procedure for calculating the stress state of the compressor disk in a gas turbine engine (GTE) in the flight cycle of loading is outlined. The calculated stress state and models of multiaxial fatigue fracture are used to estimate the service life of the compressor disk. The results are compared with the observational data collected during the operation

A Gromov-Hausdorff distance between von Neumann algebras and an application to free quantum fields

A distance between von Neumann algebras is introduced, depending on a further norm inducing the w*-topology on bounded sets. Such notion is related both with the Gromov–Hausdorff distance for quantum metric spaces of Rieffel and with the Effros–Maréchal topology on the von Neumann algebras acting on a Hilbert space. This construction is tested on the local algebras of free quantum fields endowed with norms related with the Buchholz–Wichmann nuclearity condition, showing the continuity of such algebras w.r.t. the mass parameter

Orientation and symmetries of Alexandrov spaces with applications in positive curvature

We develop two new tools for use in Alexandrov geometry: a theory of ramified orientable double covers and a particularly useful version of the Slice Theorem for actions of compact Lie groups. These tools are applied to the classification of compact, positively curved Alexandrov spaces with maximal symmetry rank.Comment: 34 pages. Simplified proofs throughout and a new proof of the Slice Theorem, correcting omissions in the previous versio

СКОРОСТЬ РЕЗОРБЦИИ ТРАНСПЛАНТАТА НА ОСНОВЕ ПОЛИГИДРОКСИАЛКАНОАТОВ И МУЛЬТИПОТЕНТНЫХ МЕЗЕНХИМАЛЬНЫХ СТРОМАЛЬНЫХ КЛЕТОК

The article presents the findings of histological analysis of local tissue response to subcutaneous implantation of polyhydroxyalkanoatebased scaffolds and scaffolds with multipotent mesenchymal stromal cells. There were no rejection and acute inflammatory response of the implanted biopolymeric materials. The connective tissue capsule has formed around the implanted materials. Active cell infiltration of the implanted material and its vascularization have been observed. The implanted scaffolds undergo slow biodegradation. The presence of multipotent mesenchymal stromal cells on the scaffold surface slows down the resorption rate of the polymer.В статье представлены результаты гистологического исследования местной реакции тканей при подкожной имплантации биополимерных матриксов на основе полиоксиалканоатов и мультипотентных мезенхимальных стромальных клеток. Показано, что имплантированный материал не вызывает отторжения и острой воспалительной реакции. Вокруг имплантированных материалов формируется соединительнотканная капсула. Наблюдается активная инфильтрация имплантированного материала клетками и васкуляризация. Имплантированные матриксы подвергаются медленной биодеструкции. Наличие мультипотентных мезенхимальных стромальных клеток на поверхности матриксов замедляет скорость резорбции полимера

Collective consciousness and its pathologies: Understanding the failure of AIDS control and treatment in the United States

We address themes of distributed cognition by extending recent formal developments in the theory of individual consciousness. While single minds appear biologically limited to one dynamic structure of linked cognitive submodules instantiating consciousness, organizations, by contrast, can support several, sometimes many, such constructs simultaneously, although these usually operate relatively slowly. System behavior remains, however, constrained not only by culture, but by a developmental path dependence generated by organizational history, in the context of market selection pressures. Such highly parallel multitasking – essentially an institutional collective consciousness – while capable of reducing inattentional blindness and the consequences of failures within individual workspaces, does not eliminate them, and introduces new characteristic malfunctions involving the distortion of information sent between workspaces and the possibility of pathological resilience – dysfunctional institutional lock-in. Consequently, organizations remain subject to canonical and idiosyncratic failures analogous to, but more complicated than, those afflicting individuals. Remediation is made difficult by the manner in which pathological externalities can write images of themselves onto both institutional function and corrective intervention. The perspective is applied to the failure of AIDS control and treatment in the United States