This paper presents a method to interactively deform volume images with heterogeneous structural content, using coarse tetrahedral meshes. It rests on two major components: a massively parallel algorithm for the rasterization of tetrahedral meshes, and a method to define a coarse deformable tetrahedral mesh from the homogenization of a fine heterogeneous mesh. We show the potential of the metho...

A new algorithm for simulation of non-isothermal flow in a twin-screw extruder is introduced. In the new algorithm, the finite element mesh of tetrahedral elements is created in the complete barrel including the space occupied by the screws. By partitioning the tetrahedral elements which are intersected by the screw surfaces into two tetrahedral, pyramidal or prismatic finite elements, the new ...

4 A drawing of a graph is pseudolinear if there is a pseudoline arrangement such that 5 each pseudoline contains exactly one edge of the drawing. The pseudolinear crossing 6 number c̃r(G) of a graph G is the minimum number of pairwise crossings of edges in 7 a pseudolinear drawing of G. We establish several facts on the pseudolinear crossing 8 number, including its computational complexity and i...

Finite element simulations in computational biomechanics commonly require the discretization of extremely complicated geometries. Creating meshes for these complex geometries can be very difficult and time consuming using hexahedral elements. Automatic meshing algorithms exist for tetrahedral elements, but these elements often have numerical problems that discourage their use in complex finite ...

Structures and energetics of various types of silicon nanowires have been investigated using quantum molecular dynamics simulations to determine the most stable forms. The tetrahedral type nanowires oriented in the 111 direction are found to be the most stable. The stability of the cagelike nanowires is determined to lie somewhere between this and tetrahedral nanowires oriented in other directi...

This paper is about two arrangements of hyperplanes. The first — the Shi arrangement — was introduced by Jian-Yi Shi to describe the Kazhdan-Lusztig cells in the affine Weyl group of type A. The second — the Ish arrangement — was recently defined by the first author who used the two arrangements together to give a new interpretation of the q, t-Catalan numbers of Garsia and Haiman. In the prese...

The lunar rocks described in the next chapter are unique to the Moon. Their special characteristics— especially the complete lack of water, the common presence of metallic iron, and the ratios of certain trace chemical elements—make it easy to distinguish them from terrestrial rocks. However, the minerals that make up lunar rocks are (with a few notable exceptions) minerals that are also found ...

The reaction of AlCl3 with Me2E (E = S, Se or Te) or (n)Bu2E (E = Se or Te) in CH2Cl2 under rigorously anhydrous conditions gave the pseudo-tetrahedral complexes [AlCl3(R2E)]. The [AlX3(Me2E)] (X = Br or I, E = S; X = Br, E = Te) were made from toluene solution since attempted syntheses in CH2Cl2 resulted in substantial chloride incorporation. The synthesis of [(AlCl3)2{o-C6H4(CH2SEt)2}], in wh...

Four copper(II) complexes with the ligands bearing two or three alkylpyridine pendant arms attached to an ethylene diamine framework were isolated in pure form (four-coordinate species as perchlorates, and five-coordinate species as hexafluorophosphates). Three complexes and one tosylated ligand were characterized by X-ray diffraction. In the absence of additional monoor bidentate ligands, line...