Ordering at two length scales in comb-coil diblock copolymers consisting of only two different monomers

The microphase separated morphology of a melt of a specific class of comb-coil diblock copolymers, consisting of an AB comb block and a linear homopolymer A block, is analyzed in the weak segregation limit. On increasing the length of the homopolymer A block, the systems go through a characteristic series of structural transitions. Starting from the pure comb copolymer the first series of structures involve the short length scale followed by structures involving the large length scale. A maximum of two critical points exists. Furthermore, in the two parameter space, characterizing the comb-coil diblock copolymer molecules considered, a non-trivial bifurcation point exists beyond which the structure factor can have two maxima (two correlation hole peaks).Comment: 22 pages, 12 Postscript figures (revtex

Bi-Plane X-ray coronary 3D reconstruction for flow velocity assessment

In coronary angiography the coronary blood flow velocity can be assessed by tracking a contrast agent in an image sequence. The contrast agent flow velocity is used to estimate the functional behavior of the coronary arteries using TIMI frame count (TFC). In this paper we descibe the 3D reconstruction algorithm used in our method towards the automation of TFC. The method creates a two dimensional map of the contrast agent in which the opacification of the vessel centerline is plotted against time. This map is used to find the velocity of the contrast agent and subsequently the TFC. The vessel centerline is obtained using the Fast Marching Method to find the minimum cost path between\ud the catheter point and the end of the vessel. The determination of the start and endpoint is estimated using a 3D model reconstructed from bi-plane 2D image\ud data. The final reconstructed coronary model only includes the segments matching our error criterion

Donald Trump's rhetoric has only highlighted the already growing rift between the EU and the US

On the first anniversary of Donald Trump's presidency, the future of the transatlantic relationship is as uncertain as ever. According to Lisa ten Brinke, the rift between the EU and the US began before Trump entered the Oval Office, and this is not likely to change any time soon