Supported particle track etched polyimide membranes: a grazing incidence small-angle X-ray scattering study

Particle track etched polyimide membranes on silicon substrates covered with a native oxide layer are investigated. Preparation steps similar to the common classical particle track etched membrane production, giving rise to free-standing membranes, are successfully applied to the supported membranes. Polyimide films are used as a starting material for a template preparation based on high energy ion irradiation. The film/membrane structure is probed at different length scales by grazing incidence small-angle X-ray scattering at each individual preparation step. In addition, characterization with atomic force microscopy, variable-angle spectroscopic ellipsometry, Fourier transform infrared transmission, and attenuated total reflection spectroscopy is performed. An amount of 6 +/- 1 vol % pores inside the polyimide film is detected. The pores are oriented perpendicular to the substrate surface and have a conical shape, yielding a slightly reduced pore size at the substrate/film interface.     

Interaction phenomena between liquid droplets and hot particles—Captured via high-speed camera

The interaction of evaporating droplets and hot catalyst particles plays a major role in heterogeneously catalysed reactions.The liquid feed is injected into a gas–solid flow and is mixed with the catalyst.The interaction phenomena determine the evaporation time which should be minimised to keep the reactor vessel small.First measurements with a bed of fixed hot FCC-particles(fluid catalytic cracking)and two model fluids have been conducted.The interactions of ethanol and water droplets with the hot bed sur...     

Ga actions on Cn

Rational actions of the additive group of complex numbers on complex n space are considered. A ring theoretic criterion for properness is given, along with ideal theoretic criteria for local triviality of such actions. The relationship between local triviality and flatness of the polynomial ring over its subring of Ga invariants is investigated.     

The higher geometric invariants for groups with sufficient commutativity

The higher geometric invariants ∑ ^k (G;Z) and ∑ ^k (G) of [BR] and [Re 1], [Re 2] are examined for groups satisfying certain commutativity relations. The main application computes these invariants for direct products of 1-relator or 3-manifold groups.     

Investigation of failure mechanisms in polymer composites by simultaneous measurement of ultra-small-angle scattering and acoustic emission during the deformation. II. Evaluation of the interface strength

The failure mechanism in polystyrene (PS) filled with glass beads was investigated with the methods of ultra-small-angle X-ray scattering (USAXS) and acoustic emission (AE) analysis simultaneously. The interface in the composites was tailored using carboxyl-terminated PS (PS-COOH). Monolayers of PSCOOH were prepared on the glass surface in a wide range of grafting densities, from single chains to a polymer brush. The layers were characterized by ellipsometry, scanning probe microscopy, and the wetting method. The morphology of the layers is in good agreement with the theoretical predictions. USAXS experiments identify submicrovoids (SMVs) at the interface in the composites even before a tensile deformation. The uniaxial loading of the specimens is followed by a debonding (dewetting) process that is identified by simultaneous increase of integral scattering intensity and AE signals. The stress of debonding is proportional to the grafting density of PS-COOH. The amplitude of the AE     

Distributive Envelopes and Topological Duality for Lattices via Canonical Extensions

We establish a topological duality for bounded lattices. The two main features of our duality are that it generalizes Stone duality for bounded distributive lattices, and that the morphisms on either side are not the standard ones. A positive consequence of the choice of morphisms is that those on the topological side are functional. Towards obtaining the topological duality, we develop a universal construction which associates to an arbitrary lattice two distributive lattice envelopes with a Galois connection between them. This is a modification of a construction of the injective hull of a semilattice by Bruns and Lakser, adjusting their concept of ‘admissibility’ to the finitary case. Finally, we show that the dual spaces of the distributive envelopes of a lattice coincide with completions of quasi-uniform spaces naturally associated with the lattice, thus giving a precise spatial meaning to the distributive envelopes.     

GIUSAXS and AFM studies on surface reconstruction of latex thin films during thermal treatment

The structural evolution of a single-layer latex film during annealing was studied via grazing incidence ultrasmall-angle X-ray scattering (GIUSAXS) and atomic force microscopy (AFM). The latex particles were composed of a low-Tg (-54 degrees C) core (n-butylacrylate, 30 wt %) and a high-Tg (41 degrees C) shell (t-butylacrylate, 70 wt %) and had an overall diameter of about 500 nm. GIUSAXS data indicate that the q(y) scan at q(z) = 0.27 nm(-1) (out-of-plane scan) contains information about both the structure factor and the form factor. The GIUSAXS data on latex films annealed at various temperatures ranging from room temperature to 140 degrees C indicate that the structure of the latex thin film beneath the surface changed significantly. The evolution of the out-of-plane scan plot reveals the surface reconstruction of the film. Furthermore, we also followed the time-dependent behavior of structural evolution when the latex film was annealed at a relatively low temperature (60 degrees C) where restructuring within the film can be followed that cannot be detected by AFM, which detects only surface morphology. Moreover, compared to AFM studies GIUSAXS provides averaged information covering larger areas.     

Mapping the damaged zone around the crack tip in high density polyethylene with synchrotron microfocus small angle X-ray scattering technique

<正>The structural changes around a crack tip in a high density polyethylene were investigated by means of scanning synchrotron microfocus small-angle X-ray scattering technique.The scattering data confirm the process of craze structure development near a crack tip based on the evolution of voids.In addition,it was found that the main stress in the plastic zone near a crack tip exhibited a gradient distribution with respect to its strength and direction.The whole damaged area showed a strain distribution indicating a flow behavior toward the crack tip.     

Canonical extensions of double quasioperator algebras: An algebraic perspective on duality for certain algebras with binary operations

The context for this paper is a class of distributive lattice expansions, called double quasioperator algebras (DQAs). The distinctive feature of these algebras is that their operations preserve or reverse both join and meet in each coordinate. Algebras of this type provide algebraic semantics for certain non-classical propositional logics. In particular, MV-algebras, which model the ?ukasiewicz infinite-valued logic, are DQAs.Varieties of DQAs are here studied through their canonical extensions. A variety of this type having additional operations of arity at least 2 may fail to be canonical; it is already known, for example, that the variety of MV-algebras is not. Non-canonicity occurs when basic operations have two distinct canonical extensions and both are necessary to capture the structure of the original algebra. This obstruction to canonicity is different in nature from that customarily found in other settings. A generalized notion of canonicity is introduced which is shown to circumvent the problem. In addition, generalized canonicity allows one to capture on the canonical extensions of DQAs the algebraic operations in such a way that the laws that these obey may be translated into first-order conditions on suitable frames. This correspondence may be seen as the algebraic component of duality, in a way which is made precise.In many cases of interest, binary residuated operations are present. An operation h which, coordinatewise, preserves ∨ and 0 lifts to an operation which is residuated, even when h is not. If h also preserves binary meet then the upper adjoints behave in a functional way on the frames.