Not saying, not doing: Convergences, contingencies and causal mechanisms of state reform and decentralisation in Hollande’s France

Are States in contemporary Europe subject to new forms of convergence under the impact of economic crisis, enhanced European steering and international monitoring? Or is the evolution of governance (national and sub-national) driven fundamentally by diverging, mainly domestic pressures? Drawing on extensive new data, the article combines analysis of the State Modernisation and Decentralisation reform programmes of the Hollande–Ayrault administration, drawing comparisons where appropriate with the previous Sarkozy regime. The limits of President Hollande’s anti-Sarkozy method were demonstrated in the first 2 years; framing state reform and decentralisation in negative terms prevented the emergence of a coherent legitimising discourse. The empirical data is interpreted with reference to a comparative ‘States of Convergence’ framework, which is conceptualised as a heuristic device for analysing variation between places, countries and policy fields. The article concludes that the forces of hard convergence are gaining ground, as economic, epistemic and European pressures continually challenge the forces of institutional inertia

First stages of crystallization of the poly(ethylene oxide)-resorcinol molecular complex

Time-resolved SAXS has been used to follow isothermal crystallization in the PEO 6000/Resorcinol molecular complex. It has been shown that the complex exhibit crystals with PEO chains in the fully extended form. The initial stages of crystallization are strongly dependent on the temperature : at high supercooling transient once-folded chains crystals are evidenced. They thicken in a single step to give extended chain crystals

Morphological Study and Melting Behavior of Narrow Molecular Weight Fractions of Poly(aryl ether ether ketone) (PEEK) Annealed from the Glassy State

The morphology of several semicrystalline poly(aryl ether ether ketone) (PEEK) samples with narrow molecular weight distributions and of a commercial sample of PEEK has been investigated by means of differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), and small-angle X-ray scattering (SAXS). The use of different molecular weights allows us to enlarge the macroscopic crystallinity range usually attainable for the commercial PEEK grades. WAXD and DSC data are in good agreement to estimate the weight degree of crystallinity values ranging from ∼15% for the highest molecular weight sample to ∼55% for the lowest molecular weight sample. Most of the investigated samples exhibit the well-known double melting behavior with a low and a high melting endotherm. This behavior is interpreted in the light of a melting−recrystallization mechanism which is strongly affected by the presence of entanglements in the amorphous zones. The analysis of the SAXS data shows that, under constant annealing conditions, the crystal thickness (given by the smallest length obtained from the correlation function) remains unaffected by a change of the molecular weight while the amorphous layer is found to strongly increase with increasing chain length due to the presence of entanglements. This leads to a decrease in the linear degree of crystallinity within the lamellar stacks which is consistent with the behavior of the macroscopic degree of crystallinity obtained from WAXD, DSC, and density measurements

Time-Resolved SAXS, WAXS, and DSC Study of Melting of Poly(aryl ether ether ketone) (PEEK) Annealed from the Amorphous State

The melting behavior of semicrystalline samples of PEEK crystallized from the glassy state was investigated by differential scanning calorimetry (DSC) and simultaneous time-resolved small-angle (SAXS) and wide-angle (WAXS) X-ray diffraction. The long spacing L and the invariant were computed from the Lorentz SAXS intensity curves. The amorphous La and crystalline Lc thickness as well as the linear degree of crystallinity vclin were obtained from the correlation function γ(r). The wide-angle and small-angle integrated intensities were correlated to the degree of crystallinity obtained by DSC throughout the melting. The double-melting behavior of samples prepared by annealing at temperatures below 315 °C can be attributed to a melting−recrystallization process of a single population of crystals. The structural parameters of the reorganized lamellae in the different samples become identical as soon as the temperature exceeds the annealing temperature. Annealing at temperatures corresponding to the second melting point region (340 °C) generates a sample containing two populations of lamellae with a melting behavior very different from that of the samples prepared at lower temperatures

Cold Crystallization of Narrow Molecular Weight Fractions of PEEK

Several amorphous narrow molecular weight fractions of poly(aryl ether ether ketone) or PEEK have been heated from below their glass transition temperature to above their final melting point. The semicrystalline morphology induced by cold crystallization and its thermal evolution are studied by time-resolved simultaneous small-angle X-ray scattering (SAXS), wide-angle X-ray diffraction, and differential scanning calorimetry. The long period and the crystalline and the amorphous thicknesses are computed from the correlation function of the SAXS curves. The evolution of the structural parameters of the various semicrystalline samples can be reconciled with the existence of a single distribution of lamellae which undergoes reorganization during the continuous heating. The reorganization process as well as the semicrystalline morphology depends on the molecular weight of the fractions. The amorphous thickness strongly increases with the molecular weight while the thermal evolution of the thickness of the crystalline layers is similar for all fractions. These experimental results support the view that the larger degree of entanglements of the high molecular weight samples impedes the reorganization mechanism with the consequence that the apparent melting temperature decreases with increasing average molecular weight

A dual detector single readout system for simultaneous small (SAXS) and wide-angle X-ray (WAXS) scattering

A data acquisition system is described which allows to simultaneously record X-ray scattering patterns in different angular regimes both with high spatial and temporal resolution. It consists of two linear detectors with delay-line readout connected in series. A few examples illustrate its application in the study of the polymorphism of lipid systems and their phase transitions as well as of synthetic polymers