11-Dimensional Supergravity Compactified on Calabi-Yau Threefolds

We consider generic features of eleven dimensional supergravity compactified down to five dimensions on an arbitrary Calabi-Yau threefold.Comment: TeX, harvmac, 8 pg

The Elementary Particles as Quantum Knots in Electroweak Theory

We explore a knot model of the elementary particles that is compatible with electroweak physics. The knots are quantized and their kinematic states are labelled by $D^j_{mm'}$, irreducible representations of $SU_q(2)$, where j = N/2, m = w/2, m' = (r+1)/2 and (N,w,r) designate respectively the number of crossings, the writhe, and the rotation of the knot. The knot quantum numbers (N,w,r) are related to the standard isotopic spin quantum numbers $(t,t_3,t_0)$ by $(t=N/6,t_3=-w/6,t_0=-(r+1)/6)$, where $t_0$ is the hypercharge. In this model the elementary fermions are low lying states of the quantum trefoil (N=3) and the gauge bosons are ditrefoils (N=6). The fermionic knots interact by the emission and absorption of bosonic knots. In this framework we have explored a slightly modified standard electroweak Lagrangian with a slightly modified gauge group which agrees closely but not entirely with standard electroweak theory.Comment: 29 pages; LaTex fil

Effect of Reprocessing and Excipient Characteristics on Ibuprofen Tablet Properties

Purpose: To determine excipient and ibuprofen:excipient mixture sensitivity to reprocessing produced by either direct compression or wet granulation.Methods: The effect of excipient type, technology and reprocessing on flow, compressibility and compactibility was assessed using and 8x2x2 factorial design. Design Expert® v.8.01 software was employed for data analysis. Pure excipients were processed by direct compression, while the ibuprofen:excipient mixtures were processed by wet granulation. Once compacts were produced, they were milled and reprocessed using the same technologies, respectively. Excipient properties such as particle size, porosity and densities were also evaluated.Results: For most excipients, reprocessing caused a 20 – 50 % decrease in particle size and 5 – 80 % reduction in porosity, but increased compactibility (10 – 50 %). Flow decreased (30 – 50 %) only for highly densified excipients such as calcium carbonate and calcium diphosphate.Conclusion: Microcrystalline cellulose and sorbitol are the excipients with the best tableting properties when reprocessing is conducted via wet granulation and direct compression platforms, respectively.Keywords: Reprocessing, Excipient, Microcrystalline Cellulose, Sorbitol Direct Compression, Wet Granulation, Ibuprofe

Somatic embryogenesis and efficient regeneration of Vitis vinifera L. 'Carménère' plants

Research Note

Triangular mesh parameterization with trimmed surfaces

Given a 2manifold triangular mesh $M \subset {\mathbb {R}}^3$, with border, a parameterization of $M$ is a FACE or trimmed surface $F=\{S,L_0,\ldots, L_m\}$ -- $F$ is a connected subset or region of a parametric surface $S$, bounded by a set of LOOPs $L_0,\ldots ,L_m$ such that each $L_i \subset S$ is a closed 1manifold having no intersection with the other $L_j$ LOOPs -- The parametric surface $S$ is a statistical fit of the mesh $M$ -- $L_0$ is the outermost LOOP bounding $F$ and $L_i$ is the LOOP of the ith hole in $F$ (if any) -- The problem of parameterizing triangular meshes is relevant for reverse engineering, tool path planning, feature detection, redesign, etc -- Stateofart mesh procedures parameterize a rectangular mesh $M$ -- To improve such procedures, we report here the implementation of an algorithm which parameterizes meshes $M$ presenting holes and concavities -- We synthesize a parametric surface $S \subset {\mathbb {R}}^3$ which approximates a superset of the mesh $M$ -- Then, we compute a set of LOOPs trimming $S$, and therefore completing the FACE F=\ {S,L_0,\ldots ,L_m\} -- Our algorithm gives satisfactory results for $M$ having low Gaussian curvature (i.e., $M$ being quasi-developable or developable) -- This assumption is a reasonable one, since $M$ is the product of manifold segmentation preprocessing -- Our algorithm computes: (1) a manifold learning mapping $\phi : M \rightarrow U \subset {\mathbb {R}}^2$, (2) an inverse mapping $S: W \subset {\mathbb {R}}^2 \rightarrow {\mathbb {R}}^3$, with \ (W\) being a rectangular grid containing and surpassing $U$ -- To compute $\phi$ we test IsoMap, Laplacian Eigenmaps and Hessian local linear embedding (best results with HLLE) -- For the back mapping (NURBS) $S$ the crucial step is to find a control polyhedron $P$, which is an extrapolation of $M$ -- We calculate $P$ by extrapolating radial basis functions that interpolate points inside $\phi (M)$ -- We successfully test our implementation with several datasets presenting concavities, holes, and are extremely nondevelopable -- Ongoing work is being devoted to manifold segmentation which facilitates mesh parameterizatio

Space-Time Distribution of G-Band and Ca II H-Line Intensity Oscillations in Hinode/SOT-FG Observations

We study the space-time distributions of intensity fluctuations in 2 - 3 hour sequences of multi-spectral, high-resolution, high-cadence broad-band filtergram images (BFI) made by the SOT-FG system aboard the Hinode spacecraft. In the frequency range 5.5 < f < 8.0 mHz both G-band and Ca II H-line oscillations are suppressed in the presence of magnetic fields, but the suppression disappears for f > 10 mHz. By looking at G-band frequencies above 10 mHz we find that the oscillatory power, both at these frequencies and at lower frequencies too, lies in a mesh pattern with cell scale 2 - 3 Mm, clearly larger than normal granulation, and with correlation times on the order of hours. The mesh pattern lies in the dark lanes between stable cells found in time-integrated G-band intensity images. It also underlies part of the bright pattern in time-integrated H-line emission. This discovery may reflect dynamical constraints on the sizes of rising granular convection cells together with the turbulence created in strong intercellular downflows.Comment: 24 pages, 15 figure