We present results of Monte Carlo simulations of kinetics of spinodal ordering on a one-dimensional Ising chain with competing interactions up to third neighbors for Glauber and Kawasaki dynamics. Application of these results to the 2H-6H transformation in SiC shows that the arrested state of the transformation possesses long-range order but lacks short-range correlations.PACS numbers: 61.50. Ks, 64.70.Kb, 81.30.Kf Solid-state transformations from one close-packed modification to another in materials like SiC, ZnS, Cdh, cobalt and its alloys, 1 and martensites of copper-based alloys 2,3 take place through nucleation and propagation of stacking faults on the basal plane. These transformations often get arrested much before completion because of the formation of domains of the product phase in different orientations. 4,5 The arrested state has generally been described as a heavily disordered state because of the presence of extensive diffuse streaking along c* for HK.L reciprocal-lattice rows with H -A^0(mod3) (Ref. 6) on the diffraction patterns. The diffuse streaking does not disappear even after repeated annealings. Recently we have undertaken 7 a detailed Monte Carlo simulation study of the kinetics of domain formation and growth during the 2H to 6H transformation in SiC which is known 4,5 to take place above 1600°C. In this Letter, we show that the arrested state for the 2H to 6H transformation possesses long-range ordering but lacks any short-range correlation in the direction of stacking of the close-packed layers. As such, the arrested state for the 2H to 6H transformation cannot be categorized as a conventional crystal or glass.The stacking sequence of a close-packed structure, in which atoms may lie in one of the three positions A, B, or C, can also be described 8 in terms of two state variables + and -which represent relative orientations of the pairs of consecutive layers and which for our purpose correspond to up (|) and down (1) Ising spins. 9 In this notation, pairs like AB, BC, CA and BA, CB, AC are represented by + and -symbols, respectively. The 2H (AB,. . .) and 6H (ABCACB, . . .) stacking sequences may therefore be described as containing (1) and (3) bands, where the numeral within the angular brackets is obtained by addition of all the consecutive spins of the same orientation. 9 Consider the Hamiltonian given below with competing interactions between the Zhdanov-Ising spins in the direction of stacking: H--'L r T, i SiS i ± r Jr,s, = ±i.

A left-sided gallbladder can be truly ectopic or may just appear so because the falciform ligament is aberrantly placed to the right. In either case preoperative imaging can be misleading, and a careful search is needed at operation. The incidence of disease seems no commoner than in orthotopic gallbladders.

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There is a changing trend in the commonest mode and age of presentation; fewer patients are presenting with the classical triad and the mean age of presentation is higher. Reconstruction by hepaticoduodenostomy is equally effective, more physiological and less time consuming as compared to hepaticojejunostomy, if the anastomosis can be achieved without tension.