Common Infrastructure for Finite-State Based Methods and Linguistics Descriptions

Finite-state methods have been adopted widely in computational morphology and related linguistic applications. To enable efficient development of finite-state based linguistic descriptions, these methods should be a freely available resource for academic language research and the language technology industry. The following needs can be identified: (i) a registry that maps the existing approaches, implementations and descriptions, (ii) managing the incompatibilities of the existing tools, (iii) increasing synergy and complementary functionality of the tools, (iv) persistent availability of the tools used to manipulate the archived descriptions, (v) an archive for free finite-state based tools and linguistic descriptions. Addressing these challenges contributes to building a common research infrastructure for advanced language technology.

Structure of 7-ethylamino-6-methyl-4-trifluoromethylcoumarin

C13H12F3NO2, M(r) = 271.2, triclinic, P1BAR, a = 5.029 (2), b = 7.479 (2), c = 17.073 (5) angstrom, alpha = 97.98 (2), beta = 95.54 (3), gamma = 103.62 (3)-degrees, V = 612.4 (4) angstrom 3, Z = 2, D(m) = 1.463, D(x) = 1.471 g cm-3, lambda(Mo K-alpha) = 0.71069 angstrom, mu = 1.23 cm-1, F(000) = 280, T = 298 K, final R value is 0.041 for 2047 observed reflections with \F(omicron)\ greater-than-or-equal-to 6-sigma(\F(omicron)\). The N-C(sp2) bond length is 1.356 (2) angstrom. The N and C atoms of the ethylamino group deviate by < 0.15 angstrom from the plane of the aromatic ring. Short intramolecular contacts, C(3)...F(17) 2.668 (3) angstrom [H(3)...F(17) 2.39 (2) angstrom, C(3)-H(C3)...F(17) 98 (1)-degrees], C(5)...F(18) 3.074 (3) and C(5)...F(19) 3.077 (3) angstrom exist in the structure. The crystal structure is stabilized by intermolecular N-H...O hydrogen bonds with N(12)-H(N12) 0.79 (3), H(N12)...O(11)' 2.36 (3), N(12)...O(11)' (x - 1, y + 1, z) 3.105 (3) angstrom and N(12)-H(N12)...O(11)' 155 (2)-degrees.

A new strategy for the alpha-vinylation of ketones: Application to an enantioselective synthesis of sesquiterpene (+)-alpha-elemene

A new, simple and preparatively useful protocol for the construction of a-vinyl ketones, particularly those bearing a quaternary carbon centre, from the corresponding alkenes has been devised. Our four-step strategy consists of dichloroketene addition, base catalysed ring contraction to 'push-pull' cyclopropane esters, reduction and eliminative cyclopropane fragmentation to unravel the a-vinyl ketone moiety. The generality of this approach has been demonstrated with a few representative olefins and good regio- and stereocontrol has been observed. As an application of this methodology, an enantioselective synthesis of sesquiterpene hydrocarbon (+)-alpha-elemene (42) from R-(+)-limonene (43) has been accomplished.

Rayleigh-Benard convection during solidification of an eutectic solution cooled from the top

The interaction between laminar Rayleigh-Benard convection and directional solidification is studied for the case of an eutectic solution kept in a rectangular cavity cooled from the top. Experiments and numerical simulations are carried out using an NH4Cl-H2O solution as the model fluid. The flow is visualized using a sheet of laser light scattered by neutrally buoyant, hollow-glass spheres seeded in the fluid. The numerical modeling is performed using a pressure-based finite-volume method according to the SIMPLER algorithm. The present configuration enables us to visualize flow vortices in the presence of a continuously evolving solid/liquid interface. Clear visualization of the Rayleigh-Benard convective cells and their interaction with the solidification front are obtained. It is observed that the convective cells are characterized by zones of up-flow and down-flow, resulting in the development of a nonplanar interface. Because of the continuous advancement of the solid/liquid interface, the effective liquid height of the cavity keeps decreasing. Once the height of the fluid layer falls below a critical value, the convective cells become weaker and eventually die out, leading to the growth of a planar solidification front. Results of flow visualization and temperature measurement are compared with those from the numerical simulation, and a good agreement is found.

Nonlinear Finite-Element Modeling of Batter Piles under Lateral Load

In this paper, a finite-element model is developed in which the nonlinear soil behavior is represented by a hyperbolic relation for static load condition and modified hyperbolic relation, which includes both degradation and gap for a cyclic load condition. Although batter piles are subjected to lateral load, the soil resistance is also governed by axial load, which is incorporated by considering the P-Δ moment and geometric stiffness matrix. By adopting the developed numerical model, static and cyclic load analyses are performed adopting an incremental-iterative procedure where the pile is idealized as beam elements and the soil as elastoplastic spring elements. The proposed numerical model is validated with published laboratory and field pile test results under both static and cyclic load conditions. This paper highlights the importance of the degradation factor and its influence on the soil resistance-displacement (p-y) curve, number of cycles of loading, and cyclic load response.