Solvay

About: Solvay is a company organization based out in Brussels, Belgium. It is known for research contribution in the topics: Catalysis & Polymer. The organization has 6083 authors who have published 7004 publications receiving 105745 citations.

Alternative formulation of classical and quantum dynamics for non-integrable systems

Abstract: We continue our work on large Poincare systems (LPS) characterized by a continuous spectrum and a continuous set of resonances. Poincare's theorem prevents the existence of solutions of the eigenvalue problem associated with the Hamiltonian (as well as the Liouville operator) which would be analytic in the coupling constant. In simple cases, such as the Friedrichs model studied in a recent paper, Poincare's «divergences» can be avoided using a natural time ordering of the dynamical states in the Hilbert space. However, in general, the time ordering has to be performed in the Liouville space of density matrices

Bethe Equations "on the Wrong Side of Equator"

Abstract: We analyse the famous Baxter's $T-Q$ equations for $XXX$ ($XXZ$) spin chain and show that apart from its usual polynomial (trigonometric) solution, which provides the solution of Bethe-Ansatz equations, there exists also the second solution which should corresponds to Bethe-Ansatz beyond $N/2$. This second solution of Baxter's equation plays essential role and together with the first one gives rise to all fusion relations.

Support for catalysts, process for the manufacture of a precursor gel of a support for catalysts, catalyst for the polymerization of olefins and process for the polymerization of olefins by means of this catalyst

Abstract: Support for catalysts, containing at least two constituents chosen from silica, alumina and aluminium phosphate, having a specific surface of 100 to 800 m 2 /g, a crystallization temperature greater than or equal to 700° C. and a pore volume of 1.5 to 4 cm 3 /g, the specific surface (SS) and the pore volume (PV) corresponding to the relationship: SS<(PV×564-358). Process for the manufacture of such a support, according to which an alcohol, water, a silicon alkoxide and an acid are mixed under conditions such that gelling or precipitation of silica is prevented, an acidic solution of an aluminium compound and/or a solution of a source of phosphate ions are added thereto, a gelling agent is added thereto, a gel is recovered which is washed with water and then by means of an organic liquid, the gel is then dried until a powder is obtained, and the powder is calcined. Polymerization of olefins in the presence of a catalyst containing chromium on a support as described above.

Efferent functions of C-fiber nociceptors.

Abstract: C-fiber nociceptors not only serve afferent but also local efferent functions. The local efferent functions, such as vasodilatation, axon reflex flare reaction, plasma extravasation, and modulation of neuronal activity, are mediated via a local release of substance P, neurokinin A, and calcitonin gene-related peptide (CGRP) from the peripheral ending. CGRP is the main mediator of the capsaicin-induced flare reaction in the mammalian skin (including humans). In the pig skin the vasodilatation is due to activation of specific heat nociceptors. In the pigeon, antidromic vasodilatation is markedly inhibited by intrinsic galanin. Plasma extravasation in the pig skin blister base or using microdialysis can be evoked by histamine, but not by electrical stimulation or capsaicin. The neurogenic component of the histamine response (64%) appears to be mediated via NK2 receptors and can be modulated by CGRP. There is some evidence that the neuropeptides can also sensitize or stimulate nociceptors. Since in the fibromyalgia syndrome an increased sensitivity of the flare reaction has been observed, the hyperalgesia might be partly due to altered functions of C-fiber nociceptors.