On a stationary transport equation

Summary Let Ω, Γ,v, a andX be as described at the beginning of the introduction below, letp∈]1, +∞[, and setq=p/(p-1). Ifp>2, we also assume that the mean curvature {itx}{su(itx)} of Γ is everywhere nonnegative. In this paper we solve the existence problem in spacesX, for equation (1.1) below, ifX=W ₀ ^1,q , orX=W ⁻¹,p. As a by-product, the solvability of (1.1) in spacesW ^1,pandL ^pfollows (without any assumption on {itx}{su(itx)}). For more general results on the above problem, see ref. [1].     

Di­chloro­bis­(glycocy­amine-O)copper(II)

The title compound, [CuCl₂(C₃H₇N₃O₂)₂], is a new copper(II) complex with glycocy­amine [(di­amino­methyl­ene­amino)­acetic acid], the first complex ever reported with this organic mol­ecule. It is composed of discrete centrosymmetric coordinated Cu^II monomers, the Cu atoms being located at inversion centers. Each metal ion is square-planar coordinated by two Cl atoms and two glycocy­amine O atoms. The coordinating glycocy­amine mol­ecule exists as a zwitterion, the H atom from the carboxyl group being transferred to the guanidinium group. A three-dimensional network of hydrogen bonds links the monomers and stabilizes the structure.     

Thermal study of prednisolone polymorphs

Prednisolone, a commercial product (polymorph 1), when crystallized from a methanol-water mixture, gives polymorph 2. By heating form 2, polymorph 3 has been isolated. The thermal behaviour of the three forms has been studied.     

On the singular limit for slightly compressible fluids

In this paper we study the motion of slightly compressible inviscid fluids. We prove that the solution of the corresponding system of nonlinear partial differential equations converges (uniformly) in the strong norm (that of the data space) to the solution of the incompressible equations, as the Mach number goes to zero (see Theorem 1.2). Actually, our proof applies to a large class of singular limit problems as shown in the Theorem 2.2.     

Investigation and physicochemical characterization of vinpocetine-sulfobutyl ether beta-cyclodextrin binary and ternary complexes

The purpose of this study was to investigate the interactions between vinpocetine (VP), sulfobutyl ether beta-cyclodextrin (SBEbetaCD) and the water-soluble polymers polyvinylpyrrolidone (PVP) and hydroxypropyl methylcellulose (HPMC). The water-soluble polymers were shown to improve the complexation efficiency of SBEbetaCD, and thus less SBEbetaCD was needed to prepare solid VP-SBEbetaCD complexes in the presence of the polymers. The interactions between VP and SBEbetaCD, with or without PVP or HPMC, were thoroughly investigated in aqueous solutions using the phase-solubility method as well as in the solid state. The amount of VP solubilized in water or aqueous polymer solution increased linearly with increasing SBEbetaCD concentration, demonstrating A(L)-type plots. We estimated the apparent stability constant (K(c)) at room temperature of VP-SBEbetaCD binary complex to be 340 M(-1) and this value increased to 490 M(-1) or 390 M(-1), respectively, with the addition of PVP and HPMC, assuming a 1 : 1 VP-SBEbetaCD molar ratio. Improvement in the K(c) values for ternary complexes clearly confirmed the benefit of the addition of water-soluble polymers to promote higher complexation efficiency. Solid VP-SBEbetaCD binary and ternary systems were prepared by physical mixing, kneading, coevaporation, and lyophilization methods and fully characterized by scanning electron microscopy, differential scanning calorimetry, and X-ray diffractometry. The results obtained suggest that coevaporation and lyophilization methods yield a higher degree of amorphous entities and indicated formation of VP-SBEbetaCD binary and ternary complexes.     

The thermal behaviour of solid phases in the TeSeO2 system

A comparative study is made of the thermoanalytical stabilities of various tellurium and selenium mixed oxides (TeSeO₄, Te₂SeO₆, Te₃SeO₈, Te₄SeO₁₀ and Te₈SeO₁₈). The observed stabilities are then approximately correlated with data given by a kinetic analysis of the thermal decomposition processes in the non-isothermal regime obtained from TG and DSC by using two calculation methods (Freeman and Carroll and modified Freeman and Carroll).