Analyzing the Cutting Process of a Heated Flexible Blade in Extruded Polystyrene Foam

For the “Free Form Thick Layered Object Manufacturing” technology that is being developed at the Delft University, it is vital that Extruded Polystyrene Foam (XPS) can be cut accurately with a heated blade. The shape of the blade is actively controlled during the cutting process, which results in double curved cutting surfaces. In order to make this cutting process controllable it must be known how the cutting behavior is under varying conditions, like cutting speed, cutting angle and heating power. The authors executed a range of experiments, analyzed the results and describe a practical model for the cutting process of XPS with a heated blade.Mechanical Engineerin

Seasonal Variability of the Labrador Current and Shelf Circulation off Newfoundland

Three-dimensional finite element models were established for the Newfoundland and Labrador Shelf to investigate climatological monthly mean wind- and density-driven circulation. The model was forced using wind stresses from the National Center for Environmental Prediction-National Center for Atmospheric Research reanalysis data prescribed at the sea surface, large-scale remote forcing determined from a North Atlantic model, monthly mean temperature and salinity climatology, and M2 tide on the open boundary. The model results were examined against various in situ observations (moored current meter, tide gauge, and vessel-mounted acoustic Doppler current profiler data) and satellite drift measurements and discussed together with literature information. The seasonal mean circulation solutions were investigated in terms of relative importance of wind to density forcing for the Labrador Current. The model results indicate significant seasonal and spatial variations, consistent generally with previous study results and in approximate agreement with observations for the major currents. The region is dominated by the equatorward flowing Labrador Current along the shelf edge and along the Labrador and Newfoundland coasts. The Labrador Current is strong in the fall/winter and weak in the spring/summer. The mean transport of the shelf edge Labrador Current is 7.5 Sv at the Seat Island transect and 5.5 Sv through the Flemish Pass. The seasonal ranges are 4.5 and 5.2 Sv at the two sections, respectively. Density- and wind-driven components are both important in the inshore Labrador Current. The density-driven component dominates the mean component of the shelf edge Labrador Current while the large-scale wind-forcing contributes significantly to its seasonal variability

Studies on X(4260) and X(4660) particles

Studies on the X(4260) and X(4660) resonant states in an effective lagrangian approach are reviewed. Using a Breit--Wigner propagator to describe their propagation, we find that the X(4260) has a sizable coupling to the $\omega\chi_{c0}$ channel, while other couplings are found to be negligible. Besides, it couples much stronger to $\sigma$ than to $f_0(980)$: $|g_{X\Psi \sigma}^2/g^2_{X\Psi f_0(980)}|\sim O(10) \ .$ As an approximate result for X(4660), we obtain that the ratio of $\frac{Br(X\rightarrow\Lambda_c^+\Lambda_c^-)}{Br(X\rightarrow\Psi(2s)\pi^+\pi^-)}\simeq 20$. Finally, taking X(3872) as an example, we also point out a possible way to extend the previous method to a more general one in the effective lagrangian approach.Comment: Talk given by H. Q. Zheng at "Xth Quark Confinement and the Hadron Spectrum", October 8-12, 2012, TUM Campus Garching, Munich, Germany. 6 pages, 3 figures, 3 table

Low and intermediate-mass close binary evolution and the initial - final mass relation

Using Eggleton's stellar evolution code, we carry out 150 runs of Pop I binary evolution calculations, with the initial primary mass between 1 and 8 solar masses the initial mass ratio between 1.1 and 4, and the onset of Roche lobe overflow (RLOF) at an early, middle, or late Hertzsprung-gap stage. We assume that RLOF is conservative in the calculations, and find that the remnant mass of the primary may change by more than 40 per cent over the range of initial mass ratio or orbital period, for a given primary mass. This is contrary to the often-held belief that the remnant mass depends only on the progenitor mass if mass transfer begins in the Hertzsprung gap. We fit a formula, with an error less than 3.6 per cent, for the remnant (white dwarf) mass as a function of the initial mass of the primary, the initial mass ratio, and the radius of the primary at the onset of RLOF. We also find that a carbon-oxygen white dwarf with mass as low as 0.33 solar masses may be formed if the primary's initial mass is around 2.5 solar masses.Comment: 7 pages for main text, 11 pages for appendix (table A1), 12 figure