7 research outputs found
Cross-linked polyvinyl polymers versus polyureas as designed supports for catalytically active M0 nanoclustersPart III. Nanometer scale structure of the cross-linked polyurea support EnCat 30 and of the PdII/EnCat 30 and Pd0/EnCat 30NP catalysts
The cross-linked polyurea support EnCat 30, its related macromolecular complex Pd(II)/EnCat 30 and its related Pd(0)/EnCat 30NP nanocomposite are thoroughly investigated with SEM, TEM, ISEC and ESR in the solid state (SEM and TEM) and swollen state in THF (ISEC and ESR). Pd(II)/EnCat 30 and its related Pd(0)/EnCat 30NP are obtained by microencapsulation of palladium acetate in a polyurea framework, which is formed upon hydrolysis/condensation of mixtures of multi-functional oligo-arylisocyanates in dichloroethane. Most remarkably, both Pd(II)/EnCat and Pd(0)/EnCat 30NP turn out to be far more (nano) porous and swellable materials than the blank polyurea matrix (EnCat 30). It is proposed that there is a strong nanostructural effect exerted by Pd(II) species due to its interaction with functional groups (amines stemming from the hydrolysis of the isocyanato groups or ureido groups belonging to the polymer chains) during the growth of the cross-linked polymer framework. As a consequence, the catalytic species in both Pd(II)/EnCat 30 and Pd(0)/EnCat 30NP are much more accessible to molecules diffusing from liquid phases in contact with the materials and, hence, are better catalysts than expected from the morphology of blank polyurea EnCat 30
Geochronological evidence for the Alpine tectono-thermal evolution of the Veporic Unit (Western Carpathians, Slovakia)
Tectono-thermal evolution of the Veporic Unit was revealed by multiple geochronological methods, including 87Rb/86Sr on muscovite and biotite, zircon and apatite fission-track, and apatite (U-Th)/He analysis. Based on the new data, the following Alpine tectono-thermal stages can be distinguished: The Eo-Alpine Cretaceous nappe stacking (~135-95 Ma) resulted in burial of the Veporic Unit beneath the northward overthrusting Gemeric Unit and overlying Jurassic Meliata accretionary wedge. During this process the Veporic Unit reached metamorphic peak of greenschist- to amphibolite facies accompanied by orogen-parallel flow in its lower and middle crust. The subsequent evolution of this crust is associated with two distinct exhumation mechanisms related to collision with the northerly Tatric-Fatric basement. The first mechanism (~90-80 Ma) is associated with internal subhorizontal shortening of the Veporic Unit reflected by large-scale upright folding and heterogeneous exhumation of the Veporic lower crust in the cores of crustal-scale antiforms. This led to juxtaposition of the higher and lower grade parts of basement, all cooled down to ~350 °C by ~80 Ma. The second mechanism is associated with the overthrusting of the Veporic Unit over the attenuated Fatric crust. This led to a passive en-block exhumation of the Veporic crust from ~350 °C to 60 °C between ~80 and 55 Ma followed by erosion (~55-35 Ma). The erosion processes resulted in formation of planation surface before the Late Eocene transgression. After erosion and planation, a new sedimentary cycle of the Central Carpathian Palaeogene Basin was deposited with the sedimentary strata thickness of ~1.5-2.0 km (~21-17 Ma). The early to middle Miocene is characterised by destruction tectonic disintegration and erosion of this basin (~20-13 Ma) and formation of the Neogene Vepor Stratovolcano (~13 Ma). The final shaping of the area has been linked to erosional processes of the volcanic structure since the Late Sarmatian with accelerated processes during the Plio-Quaternary
Until-since temporal logic based on parallel time with common past. Deciding algorithms
We present a framework for constructing algorithms recognizing admissible inference rules (consecutions) in temporal logics with Until and Since based on Kripke/Hintikka structures modeling parallel time with common past. Logics with various branching factor after common past are considered. The offered technique looks rather flexible, for instance, with similar approach we showed [33] that temporal logic based on sheafs of integer numbers with common origin is decidable by admissibility. In this paper we extend obtained algorithms to logics . We prove that any logic is decidable w.r.t. admissible consecutions (inference rules), as a consequence, we solve satisfiability problem and show that any itself is decidable
Branching time logics BTL, U,S , N,N −1(Z)α with operations until and since based on bundles of integer numbers, logical consecutions, deciding algorithms
This paper is intended as an attempt to describe logical consequence in branching time logics. We study temporal branching time logics which use the standard operations Until and Next and dual operations Since and Previous (LTL, as standard, uses only Until and Next). Temporal logics are generated by semantics based on Kripke/Hinttikka structures with linear frames of integer numbers with a single node (glued zeros). For , the permissible branching of the node is limited by α (where 1≤α≤ω). We prove that any logic is decidable w.r.t. admissible consecutions (inference rules), i.e. we find an algorithm recognizing consecutions admissible in . As a consequence, it implies that itself is decidable and solves the satisfiability problem